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phunix/external/gpl2/gmake/patches/0000-gmake-nbsd.patch
Lionel Sambuc 0a6a1f1d05 NetBSD re-synchronization of the source tree 
This brings our tree to NetBSD 7.0, as found on -current on the
10-10-2015.

This updates:
 - LLVM to 3.6.1
 - GCC to GCC 5.1
 - Replace minix/commands/zdump with usr.bin/zdump
 - external/bsd/libelf has moved to /external/bsd/elftoolchain/
 - Import ctwm
 - Drop sprintf from libminc

Change-Id: I149836ac18e9326be9353958bab9b266efb056f0
2016-01-13 20:32:14 +01:00

11981 lines
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diff -rNU3 dist.orig/Makefile.in dist/Makefile.in
--- dist.orig/Makefile.in 2006-04-01 08:40:04.000000000 +0200
+++ dist/Makefile.in 2014-08-18 08:57:25.000000000 +0200
@@ -330,6 +330,8 @@
am--refresh:
@:
$(srcdir)/Makefile.in: $(srcdir)/Makefile.am $(am__configure_deps)
+ @echo "NOT REBUILDING $@"
+NetBSD_DISABLED_Makefile.in:
@for dep in $?; do \
case '$(am__configure_deps)' in \
*$$dep*) \
@@ -357,6 +359,8 @@
$(SHELL) ./config.status --recheck
$(top_srcdir)/configure: $(am__configure_deps)
+ @echo "NOT REBUILDING $@"
+NetBSD_DISABLED_configure:
cd $(srcdir) && $(AUTOCONF)
$(ACLOCAL_M4): $(am__aclocal_m4_deps)
cd $(srcdir) && $(ACLOCAL) $(ACLOCAL_AMFLAGS)
@@ -371,6 +375,8 @@
@rm -f stamp-h1
cd $(top_builddir) && $(SHELL) ./config.status config.h
$(srcdir)/config.h.in: $(am__configure_deps)
+ @echo "NOT REBUILDING $@"
+NetBSD_DISABLED_config.h.in:
cd $(top_srcdir) && $(AUTOHEADER)
rm -f stamp-h1
touch $@
diff -rNU3 dist.orig/ansi2knr.c dist/ansi2knr.c
--- dist.orig/ansi2knr.c 2006-04-01 08:40:04.000000000 +0200
+++ dist/ansi2knr.c 2014-08-18 08:46:57.000000000 +0200
@@ -1,6 +1,6 @@
/* Copyright (C) 1989, 2000 Aladdin Enterprises. All rights reserved. */
-/*$Id: ansi2knr.c,v 1.3 2000/04/13 03:41:48 lpd Exp $*/
+/*$Id: ansi2knr.c,v 1.1.1.1 2014/08/18 06:46:57 christos Exp $*/
/* Convert ANSI C function definitions to K&R ("traditional C") syntax */
/*
diff -rNU3 dist.orig/config/config.guess dist/config/config.guess
--- dist.orig/config/config.guess 2006-04-01 08:41:00.000000000 +0200
+++ dist/config/config.guess 2014-08-18 09:12:47.000000000 +0200
@@ -939,6 +939,9 @@
sparc:Linux:*:* | sparc64:Linux:*:*)
echo ${UNAME_MACHINE}-unknown-linux-gnu
exit ;;
+ tile*:Linux:*:*)
+ echo ${UNAME_MACHINE}-unknown-linux-gnu
+ exit 0 ;;
vax:Linux:*:*)
echo ${UNAME_MACHINE}-dec-linux-gnu
exit ;;
diff -rNU3 dist.orig/configure.in dist/configure.in
--- dist.orig/configure.in 2006-04-01 08:36:40.000000000 +0200
+++ dist/configure.in 2014-08-18 08:46:47.000000000 +0200
@@ -19,7 +19,7 @@
AC_INIT([GNU make],[3.81],[bug-make@gnu.org])
AC_PREREQ(2.59)
-AC_REVISION([[$Id: configure.in,v 1.142 2006/04/01 06:36:40 psmith Exp $]])
+AC_REVISION([[$Id: configure.in,v 1.1.1.1 2014/08/18 06:46:47 christos Exp $]])
# Autoconf setup
AC_CONFIG_AUX_DIR(config)
diff -rNU3 dist.orig/doc/make.info dist/doc/make.info
--- dist.orig/doc/make.info 2006-04-01 08:41:04.000000000 +0200
+++ dist/doc/make.info 1970-01-01 01:00:00.000000000 +0100
@@ -1,184 +0,0 @@
-This is make.info, produced by makeinfo version 4.8 from make.texi.
-
- This file documents the GNU `make' utility, which determines
-automatically which pieces of a large program need to be recompiled,
-and issues the commands to recompile them.
-
- This is Edition 0.70, last updated 1 April 2006, of `The GNU Make
-Manual', for GNU `make' version 3.81.
-
- Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
-1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006 Free Software
-Foundation, Inc.
-
- Permission is granted to copy, distribute and/or modify this
- document under the terms of the GNU Free Documentation License,
- Version 1.2 or any later version published by the Free Software
- Foundation; with no Invariant Sections, with the Front-Cover Texts
- being "A GNU Manual," and with the Back-Cover Texts as in (a)
- below. A copy of the license is included in the section entitled
- "GNU Free Documentation License."
-
- (a) The FSF's Back-Cover Text is: "You have freedom to copy and
- modify this GNU Manual, like GNU software. Copies published by
- the Free Software Foundation raise funds for GNU development."
-
-INFO-DIR-SECTION GNU Packages
-START-INFO-DIR-ENTRY
-* Make: (make). Remake files automatically.
-END-INFO-DIR-ENTRY
-
-
-Indirect:
-make.info-1: 1297
-make.info-2: 301265
-
-Tag Table:
-(Indirect)
-Node: Top1297
-Node: Overview14702
-Node: Preparing15712
-Node: Reading16684
-Node: Bugs17611
-Node: Introduction19441
-Node: Rule Introduction21033
-Node: Simple Makefile22777
-Node: How Make Works26406
-Node: Variables Simplify29061
-Node: make Deduces31267
-Node: Combine By Prerequisite33007
-Node: Cleanup34036
-Node: Makefiles35455
-Node: Makefile Contents36421
-Node: Makefile Names39376
-Node: Include40987
-Ref: Include-Footnote-144619
-Node: MAKEFILES Variable44753
-Node: MAKEFILE_LIST Variable46263
-Node: Special Variables47531
-Node: Remaking Makefiles51038
-Node: Overriding Makefiles55287
-Node: Reading Makefiles57340
-Node: Secondary Expansion60244
-Node: Rules67678
-Node: Rule Example70350
-Node: Rule Syntax71207
-Node: Prerequisite Types73710
-Node: Wildcards75486
-Node: Wildcard Examples77204
-Node: Wildcard Pitfall78460
-Node: Wildcard Function80249
-Node: Directory Search82033
-Node: General Search83175
-Node: Selective Search84890
-Node: Search Algorithm87878
-Node: Commands/Search90397
-Node: Implicit/Search91743
-Node: Libraries/Search92687
-Node: Phony Targets94779
-Node: Force Targets99865
-Node: Empty Targets100910
-Node: Special Targets102208
-Node: Multiple Targets109382
-Node: Multiple Rules111257
-Node: Static Pattern113493
-Node: Static Usage114145
-Node: Static versus Implicit117866
-Node: Double-Colon119610
-Node: Automatic Prerequisites121267
-Node: Commands125545
-Node: Command Syntax126753
-Node: Splitting Lines128778
-Node: Variables in Commands131759
-Node: Echoing133086
-Node: Execution134378
-Ref: Execution-Footnote-1135629
-Node: Choosing the Shell135775
-Node: Parallel139744
-Node: Errors143337
-Node: Interrupts146983
-Node: Recursion148570
-Node: MAKE Variable150664
-Node: Variables/Recursion152931
-Node: Options/Recursion158372
-Node: -w Option163537
-Node: Sequences164532
-Node: Empty Commands167544
-Node: Using Variables168718
-Node: Reference171831
-Node: Flavors173390
-Node: Advanced179128
-Node: Substitution Refs179633
-Node: Computed Names181186
-Node: Values185730
-Node: Setting186643
-Node: Appending188679
-Node: Override Directive192605
-Node: Defining193989
-Node: Environment196453
-Node: Target-specific198702
-Node: Pattern-specific201669
-Node: Conditionals203071
-Node: Conditional Example203781
-Node: Conditional Syntax206358
-Node: Testing Flags212083
-Node: Functions213185
-Node: Syntax of Functions214605
-Node: Text Functions216804
-Node: File Name Functions225375
-Node: Conditional Functions230597
-Node: Foreach Function232971
-Node: Call Function236183
-Node: Value Function239068
-Node: Eval Function240505
-Node: Origin Function242779
-Node: Flavor Function245997
-Node: Shell Function247063
-Node: Make Control Functions248697
-Node: Running250366
-Node: Makefile Arguments252355
-Node: Goals253071
-Node: Instead of Execution257812
-Node: Avoiding Compilation261098
-Node: Overriding263073
-Node: Testing265371
-Node: Options Summary267256
-Node: Implicit Rules277382
-Node: Using Implicit279530
-Node: Catalogue of Rules283069
-Node: Implicit Variables292419
-Node: Chained Rules297254
-Node: Pattern Rules301265
-Node: Pattern Intro302801
-Node: Pattern Examples305698
-Node: Automatic Variables307507
-Node: Pattern Match314878
-Node: Match-Anything Rules316514
-Node: Canceling Rules320389
-Node: Last Resort321105
-Node: Suffix Rules322952
-Node: Implicit Rule Search326681
-Node: Archives330200
-Node: Archive Members330898
-Node: Archive Update332511
-Node: Archive Symbols334425
-Node: Archive Pitfalls335659
-Node: Archive Suffix Rules336382
-Node: Features337929
-Node: Missing346484
-Node: Makefile Conventions350222
-Node: Makefile Basics351008
-Node: Utilities in Makefiles354175
-Node: Command Variables356313
-Node: Directory Variables359883
-Node: Standard Targets374023
-Ref: Standard Targets-Footnote-1387142
-Node: Install Command Categories387242
-Node: Quick Reference391768
-Node: Error Messages402464
-Node: Complex Makefile410154
-Node: GNU Free Documentation License418872
-Node: Concept Index441321
-Node: Name Index506510
-
-End Tag Table
diff -rNU3 dist.orig/doc/make.info-1 dist/doc/make.info-1
--- dist.orig/doc/make.info-1 2006-04-01 08:41:04.000000000 +0200
+++ dist/doc/make.info-1 1970-01-01 01:00:00.000000000 +0100
@@ -1,7261 +0,0 @@
-This is make.info, produced by makeinfo version 4.8 from make.texi.
-
- This file documents the GNU `make' utility, which determines
-automatically which pieces of a large program need to be recompiled,
-and issues the commands to recompile them.
-
- This is Edition 0.70, last updated 1 April 2006, of `The GNU Make
-Manual', for GNU `make' version 3.81.
-
- Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
-1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006 Free Software
-Foundation, Inc.
-
- Permission is granted to copy, distribute and/or modify this
- document under the terms of the GNU Free Documentation License,
- Version 1.2 or any later version published by the Free Software
- Foundation; with no Invariant Sections, with the Front-Cover Texts
- being "A GNU Manual," and with the Back-Cover Texts as in (a)
- below. A copy of the license is included in the section entitled
- "GNU Free Documentation License."
-
- (a) The FSF's Back-Cover Text is: "You have freedom to copy and
- modify this GNU Manual, like GNU software. Copies published by
- the Free Software Foundation raise funds for GNU development."
-
-INFO-DIR-SECTION GNU Packages
-START-INFO-DIR-ENTRY
-* Make: (make). Remake files automatically.
-END-INFO-DIR-ENTRY
-
-
-File: make.info, Node: Top, Next: Overview, Prev: (dir), Up: (dir)
-
-GNU `make'
-**********
-
-This file documents the GNU `make' utility, which determines
-automatically which pieces of a large program need to be recompiled,
-and issues the commands to recompile them.
-
- This is Edition 0.70, last updated 1 April 2006, of `The GNU Make
-Manual', for GNU `make' version 3.81.
-
- Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
-1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006 Free Software
-Foundation, Inc.
-
- Permission is granted to copy, distribute and/or modify this
- document under the terms of the GNU Free Documentation License,
- Version 1.2 or any later version published by the Free Software
- Foundation; with no Invariant Sections, with the Front-Cover Texts
- being "A GNU Manual," and with the Back-Cover Texts as in (a)
- below. A copy of the license is included in the section entitled
- "GNU Free Documentation License."
-
- (a) The FSF's Back-Cover Text is: "You have freedom to copy and
- modify this GNU Manual, like GNU software. Copies published by
- the Free Software Foundation raise funds for GNU development."
-
-* Menu:
-
-* Overview:: Overview of `make'.
-* Introduction:: An introduction to `make'.
-* Makefiles:: Makefiles tell `make' what to do.
-* Rules:: Rules describe when a file must be remade.
-* Commands:: Commands say how to remake a file.
-* Using Variables:: You can use variables to avoid repetition.
-* Conditionals:: Use or ignore parts of the makefile based
- on the values of variables.
-* Functions:: Many powerful ways to manipulate text.
-* Invoking make: Running. How to invoke `make' on the command line.
-* Implicit Rules:: Use implicit rules to treat many files alike,
- based on their file names.
-* Archives:: How `make' can update library archives.
-* Features:: Features GNU `make' has over other `make's.
-* Missing:: What GNU `make' lacks from other `make's.
-* Makefile Conventions:: Conventions for writing makefiles for
- GNU programs.
-* Quick Reference:: A quick reference for experienced users.
-* Error Messages:: A list of common errors generated by `make'.
-* Complex Makefile:: A real example of a straightforward,
- but nontrivial, makefile.
-
-* GNU Free Documentation License:: License for copying this manual
-* Concept Index:: Index of Concepts
-* Name Index:: Index of Functions, Variables, & Directives
-
- --- The Detailed Node Listing ---
-
-Overview of `make'
-
-* Preparing:: Preparing and Running Make
-* Reading:: On Reading this Text
-* Bugs:: Problems and Bugs
-
-An Introduction to Makefiles
-
-* Rule Introduction:: What a rule looks like.
-* Simple Makefile:: A Simple Makefile
-* How Make Works:: How `make' Processes This Makefile
-* Variables Simplify:: Variables Make Makefiles Simpler
-* make Deduces:: Letting `make' Deduce the Commands
-* Combine By Prerequisite:: Another Style of Makefile
-* Cleanup:: Rules for Cleaning the Directory
-
-Writing Makefiles
-
-* Makefile Contents:: What makefiles contain.
-* Makefile Names:: How to name your makefile.
-* Include:: How one makefile can use another makefile.
-* MAKEFILES Variable:: The environment can specify extra makefiles.
-* MAKEFILE_LIST Variable:: Discover which makefiles have been read.
-* Special Variables:: Other special variables.
-* Remaking Makefiles:: How makefiles get remade.
-* Overriding Makefiles:: How to override part of one makefile
- with another makefile.
-* Reading Makefiles:: How makefiles are parsed.
-* Secondary Expansion:: How and when secondary expansion is performed.
-
-Writing Rules
-
-* Rule Example:: An example explained.
-* Rule Syntax:: General syntax explained.
-* Prerequisite Types:: There are two types of prerequisites.
-* Wildcards:: Using wildcard characters such as `*'.
-* Directory Search:: Searching other directories for source files.
-* Phony Targets:: Using a target that is not a real file's name.
-* Force Targets:: You can use a target without commands
- or prerequisites to mark other targets
- as phony.
-* Empty Targets:: When only the date matters and the
- files are empty.
-* Special Targets:: Targets with special built-in meanings.
-* Multiple Targets:: When to make use of several targets in a rule.
-* Multiple Rules:: How to use several rules with the same target.
-* Static Pattern:: Static pattern rules apply to multiple targets
- and can vary the prerequisites according to
- the target name.
-* Double-Colon:: How to use a special kind of rule to allow
- several independent rules for one target.
-* Automatic Prerequisites:: How to automatically generate rules giving
- prerequisites from source files themselves.
-
-Using Wildcard Characters in File Names
-
-* Wildcard Examples:: Several examples
-* Wildcard Pitfall:: Problems to avoid.
-* Wildcard Function:: How to cause wildcard expansion where
- it does not normally take place.
-
-Searching Directories for Prerequisites
-
-* General Search:: Specifying a search path that applies
- to every prerequisite.
-* Selective Search:: Specifying a search path
- for a specified class of names.
-* Search Algorithm:: When and how search paths are applied.
-* Commands/Search:: How to write shell commands that work together
- with search paths.
-* Implicit/Search:: How search paths affect implicit rules.
-* Libraries/Search:: Directory search for link libraries.
-
-Static Pattern Rules
-
-* Static Usage:: The syntax of static pattern rules.
-* Static versus Implicit:: When are they better than implicit rules?
-
-Writing the Commands in Rules
-
-* Command Syntax:: Command syntax features and pitfalls.
-* Echoing:: How to control when commands are echoed.
-* Execution:: How commands are executed.
-* Parallel:: How commands can be executed in parallel.
-* Errors:: What happens after a command execution error.
-* Interrupts:: What happens when a command is interrupted.
-* Recursion:: Invoking `make' from makefiles.
-* Sequences:: Defining canned sequences of commands.
-* Empty Commands:: Defining useful, do-nothing commands.
-
-Command Syntax
-
-* Splitting Lines:: Breaking long command lines for readability.
-* Variables in Commands:: Using `make' variables in commands.
-
-Command Execution
-
-* Choosing the Shell:: How `make' chooses the shell used
- to run commands.
-
-Recursive Use of `make'
-
-* MAKE Variable:: The special effects of using `$(MAKE)'.
-* Variables/Recursion:: How to communicate variables to a sub-`make'.
-* Options/Recursion:: How to communicate options to a sub-`make'.
-* -w Option:: How the `-w' or `--print-directory' option
- helps debug use of recursive `make' commands.
-
-How to Use Variables
-
-* Reference:: How to use the value of a variable.
-* Flavors:: Variables come in two flavors.
-* Advanced:: Advanced features for referencing a variable.
-* Values:: All the ways variables get their values.
-* Setting:: How to set a variable in the makefile.
-* Appending:: How to append more text to the old value
- of a variable.
-* Override Directive:: How to set a variable in the makefile even if
- the user has set it with a command argument.
-* Defining:: An alternate way to set a variable
- to a verbatim string.
-* Environment:: Variable values can come from the environment.
-* Target-specific:: Variable values can be defined on a per-target
- basis.
-* Pattern-specific:: Target-specific variable values can be applied
- to a group of targets that match a pattern.
-
-Advanced Features for Reference to Variables
-
-* Substitution Refs:: Referencing a variable with
- substitutions on the value.
-* Computed Names:: Computing the name of the variable to refer to.
-
-Conditional Parts of Makefiles
-
-* Conditional Example:: Example of a conditional
-* Conditional Syntax:: The syntax of conditionals.
-* Testing Flags:: Conditionals that test flags.
-
-Functions for Transforming Text
-
-* Syntax of Functions:: How to write a function call.
-* Text Functions:: General-purpose text manipulation functions.
-* File Name Functions:: Functions for manipulating file names.
-* Conditional Functions:: Functions that implement conditions.
-* Foreach Function:: Repeat some text with controlled variation.
-* Call Function:: Expand a user-defined function.
-* Value Function:: Return the un-expanded value of a variable.
-* Eval Function:: Evaluate the arguments as makefile syntax.
-* Origin Function:: Find where a variable got its value.
-* Flavor Function:: Find out the flavor of a variable.
-* Shell Function:: Substitute the output of a shell command.
-* Make Control Functions:: Functions that control how make runs.
-
-How to Run `make'
-
-* Makefile Arguments:: How to specify which makefile to use.
-* Goals:: How to use goal arguments to specify which
- parts of the makefile to use.
-* Instead of Execution:: How to use mode flags to specify what
- kind of thing to do with the commands
- in the makefile other than simply
- execute them.
-* Avoiding Compilation:: How to avoid recompiling certain files.
-* Overriding:: How to override a variable to specify
- an alternate compiler and other things.
-* Testing:: How to proceed past some errors, to
- test compilation.
-* Options Summary:: Summary of Options
-
-Using Implicit Rules
-
-* Using Implicit:: How to use an existing implicit rule
- to get the commands for updating a file.
-* Catalogue of Rules:: A list of built-in implicit rules.
-* Implicit Variables:: How to change what predefined rules do.
-* Chained Rules:: How to use a chain of implicit rules.
-* Pattern Rules:: How to define new implicit rules.
-* Last Resort:: How to define commands for rules which
- cannot find any.
-* Suffix Rules:: The old-fashioned style of implicit rule.
-* Implicit Rule Search:: The precise algorithm for applying
- implicit rules.
-
-Defining and Redefining Pattern Rules
-
-* Pattern Intro:: An introduction to pattern rules.
-* Pattern Examples:: Examples of pattern rules.
-* Automatic Variables:: How to use automatic variables in the
- commands of implicit rules.
-* Pattern Match:: How patterns match.
-* Match-Anything Rules:: Precautions you should take prior to
- defining rules that can match any
- target file whatever.
-* Canceling Rules:: How to override or cancel built-in rules.
-
-Using `make' to Update Archive Files
-
-* Archive Members:: Archive members as targets.
-* Archive Update:: The implicit rule for archive member targets.
-* Archive Pitfalls:: Dangers to watch out for when using archives.
-* Archive Suffix Rules:: You can write a special kind of suffix rule
- for updating archives.
-
-Implicit Rule for Archive Member Targets
-
-* Archive Symbols:: How to update archive symbol directories.
-
-
-File: make.info, Node: Overview, Next: Introduction, Prev: Top, Up: Top
-
-1 Overview of `make'
-********************
-
-The `make' utility automatically determines which pieces of a large
-program need to be recompiled, and issues commands to recompile them.
-This manual describes GNU `make', which was implemented by Richard
-Stallman and Roland McGrath. Development since Version 3.76 has been
-handled by Paul D. Smith.
-
- GNU `make' conforms to section 6.2 of `IEEE Standard 1003.2-1992'
-(POSIX.2).
-
- Our examples show C programs, since they are most common, but you
-can use `make' with any programming language whose compiler can be run
-with a shell command. Indeed, `make' is not limited to programs. You
-can use it to describe any task where some files must be updated
-automatically from others whenever the others change.
-
-* Menu:
-
-* Preparing:: Preparing and Running Make
-* Reading:: On Reading this Text
-* Bugs:: Problems and Bugs
-
-
-File: make.info, Node: Preparing, Next: Reading, Prev: Overview, Up: Overview
-
-Preparing and Running Make
-==========================
-
- To prepare to use `make', you must write a file called the
-"makefile" that describes the relationships among files in your program
-and provides commands for updating each file. In a program, typically,
-the executable file is updated from object files, which are in turn
-made by compiling source files.
-
- Once a suitable makefile exists, each time you change some source
-files, this simple shell command:
-
- make
-
-suffices to perform all necessary recompilations. The `make' program
-uses the makefile data base and the last-modification times of the
-files to decide which of the files need to be updated. For each of
-those files, it issues the commands recorded in the data base.
-
- You can provide command line arguments to `make' to control which
-files should be recompiled, or how. *Note How to Run `make': Running.
-
-
-File: make.info, Node: Reading, Next: Bugs, Prev: Preparing, Up: Overview
-
-1.1 How to Read This Manual
-===========================
-
-If you are new to `make', or are looking for a general introduction,
-read the first few sections of each chapter, skipping the later
-sections. In each chapter, the first few sections contain introductory
-or general information and the later sections contain specialized or
-technical information. The exception is the second chapter, *Note An
-Introduction to Makefiles: Introduction, all of which is introductory.
-
- If you are familiar with other `make' programs, see *Note Features
-of GNU `make': Features, which lists the enhancements GNU `make' has,
-and *Note Incompatibilities and Missing Features: Missing, which
-explains the few things GNU `make' lacks that others have.
-
- For a quick summary, see *Note Options Summary::, *Note Quick
-Reference::, and *Note Special Targets::.
-
-
-File: make.info, Node: Bugs, Prev: Reading, Up: Overview
-
-1.2 Problems and Bugs
-=====================
-
-If you have problems with GNU `make' or think you've found a bug,
-please report it to the developers; we cannot promise to do anything but
-we might well want to fix it.
-
- Before reporting a bug, make sure you've actually found a real bug.
-Carefully reread the documentation and see if it really says you can do
-what you're trying to do. If it's not clear whether you should be able
-to do something or not, report that too; it's a bug in the
-documentation!
-
- Before reporting a bug or trying to fix it yourself, try to isolate
-it to the smallest possible makefile that reproduces the problem. Then
-send us the makefile and the exact results `make' gave you, including
-any error or warning messages. Please don't paraphrase these messages:
-it's best to cut and paste them into your report. When generating this
-small makefile, be sure to not use any non-free or unusual tools in
-your commands: you can almost always emulate what such a tool would do
-with simple shell commands. Finally, be sure to explain what you
-expected to occur; this will help us decide whether the problem was
-really in the documentation.
-
- Once you have a precise problem you can report it in one of two ways.
-Either send electronic mail to:
-
- bug-make@gnu.org
-
-or use our Web-based project management tool, at:
-
- http://savannah.gnu.org/projects/make/
-
-In addition to the information above, please be careful to include the
-version number of `make' you are using. You can get this information
-with the command `make --version'. Be sure also to include the type of
-machine and operating system you are using. One way to obtain this
-information is by looking at the final lines of output from the command
-`make --help'.
-
-
-File: make.info, Node: Introduction, Next: Makefiles, Prev: Overview, Up: Top
-
-2 An Introduction to Makefiles
-******************************
-
-You need a file called a "makefile" to tell `make' what to do. Most
-often, the makefile tells `make' how to compile and link a program.
-
- In this chapter, we will discuss a simple makefile that describes
-how to compile and link a text editor which consists of eight C source
-files and three header files. The makefile can also tell `make' how to
-run miscellaneous commands when explicitly asked (for example, to remove
-certain files as a clean-up operation). To see a more complex example
-of a makefile, see *Note Complex Makefile::.
-
- When `make' recompiles the editor, each changed C source file must
-be recompiled. If a header file has changed, each C source file that
-includes the header file must be recompiled to be safe. Each
-compilation produces an object file corresponding to the source file.
-Finally, if any source file has been recompiled, all the object files,
-whether newly made or saved from previous compilations, must be linked
-together to produce the new executable editor.
-
-* Menu:
-
-* Rule Introduction:: What a rule looks like.
-* Simple Makefile:: A Simple Makefile
-* How Make Works:: How `make' Processes This Makefile
-* Variables Simplify:: Variables Make Makefiles Simpler
-* make Deduces:: Letting `make' Deduce the Commands
-* Combine By Prerequisite:: Another Style of Makefile
-* Cleanup:: Rules for Cleaning the Directory
-
-
-File: make.info, Node: Rule Introduction, Next: Simple Makefile, Prev: Introduction, Up: Introduction
-
-2.1 What a Rule Looks Like
-==========================
-
-A simple makefile consists of "rules" with the following shape:
-
- TARGET ... : PREREQUISITES ...
- COMMAND
- ...
- ...
-
- A "target" is usually the name of a file that is generated by a
-program; examples of targets are executable or object files. A target
-can also be the name of an action to carry out, such as `clean' (*note
-Phony Targets::).
-
- A "prerequisite" is a file that is used as input to create the
-target. A target often depends on several files.
-
- A "command" is an action that `make' carries out. A rule may have
-more than one command, each on its own line. *Please note:* you need
-to put a tab character at the beginning of every command line! This is
-an obscurity that catches the unwary.
-
- Usually a command is in a rule with prerequisites and serves to
-create a target file if any of the prerequisites change. However, the
-rule that specifies commands for the target need not have
-prerequisites. For example, the rule containing the delete command
-associated with the target `clean' does not have prerequisites.
-
- A "rule", then, explains how and when to remake certain files which
-are the targets of the particular rule. `make' carries out the
-commands on the prerequisites to create or update the target. A rule
-can also explain how and when to carry out an action. *Note Writing
-Rules: Rules.
-
- A makefile may contain other text besides rules, but a simple
-makefile need only contain rules. Rules may look somewhat more
-complicated than shown in this template, but all fit the pattern more
-or less.
-
-
-File: make.info, Node: Simple Makefile, Next: How Make Works, Prev: Rule Introduction, Up: Introduction
-
-2.2 A Simple Makefile
-=====================
-
-Here is a straightforward makefile that describes the way an executable
-file called `edit' depends on eight object files which, in turn, depend
-on eight C source and three header files.
-
- In this example, all the C files include `defs.h', but only those
-defining editing commands include `command.h', and only low level files
-that change the editor buffer include `buffer.h'.
-
- edit : main.o kbd.o command.o display.o \
- insert.o search.o files.o utils.o
- cc -o edit main.o kbd.o command.o display.o \
- insert.o search.o files.o utils.o
-
- main.o : main.c defs.h
- cc -c main.c
- kbd.o : kbd.c defs.h command.h
- cc -c kbd.c
- command.o : command.c defs.h command.h
- cc -c command.c
- display.o : display.c defs.h buffer.h
- cc -c display.c
- insert.o : insert.c defs.h buffer.h
- cc -c insert.c
- search.o : search.c defs.h buffer.h
- cc -c search.c
- files.o : files.c defs.h buffer.h command.h
- cc -c files.c
- utils.o : utils.c defs.h
- cc -c utils.c
- clean :
- rm edit main.o kbd.o command.o display.o \
- insert.o search.o files.o utils.o
-
-We split each long line into two lines using backslash-newline; this is
-like using one long line, but is easier to read.
-
- To use this makefile to create the executable file called `edit',
-type:
-
- make
-
- To use this makefile to delete the executable file and all the object
-files from the directory, type:
-
- make clean
-
- In the example makefile, the targets include the executable file
-`edit', and the object files `main.o' and `kbd.o'. The prerequisites
-are files such as `main.c' and `defs.h'. In fact, each `.o' file is
-both a target and a prerequisite. Commands include `cc -c main.c' and
-`cc -c kbd.c'.
-
- When a target is a file, it needs to be recompiled or relinked if any
-of its prerequisites change. In addition, any prerequisites that are
-themselves automatically generated should be updated first. In this
-example, `edit' depends on each of the eight object files; the object
-file `main.o' depends on the source file `main.c' and on the header
-file `defs.h'.
-
- A shell command follows each line that contains a target and
-prerequisites. These shell commands say how to update the target file.
-A tab character must come at the beginning of every command line to
-distinguish command lines from other lines in the makefile. (Bear in
-mind that `make' does not know anything about how the commands work.
-It is up to you to supply commands that will update the target file
-properly. All `make' does is execute the commands in the rule you have
-specified when the target file needs to be updated.)
-
- The target `clean' is not a file, but merely the name of an action.
-Since you normally do not want to carry out the actions in this rule,
-`clean' is not a prerequisite of any other rule. Consequently, `make'
-never does anything with it unless you tell it specifically. Note that
-this rule not only is not a prerequisite, it also does not have any
-prerequisites, so the only purpose of the rule is to run the specified
-commands. Targets that do not refer to files but are just actions are
-called "phony targets". *Note Phony Targets::, for information about
-this kind of target. *Note Errors in Commands: Errors, to see how to
-cause `make' to ignore errors from `rm' or any other command.
-
-
-File: make.info, Node: How Make Works, Next: Variables Simplify, Prev: Simple Makefile, Up: Introduction
-
-2.3 How `make' Processes a Makefile
-===================================
-
-By default, `make' starts with the first target (not targets whose
-names start with `.'). This is called the "default goal". ("Goals"
-are the targets that `make' strives ultimately to update. You can
-override this behavior using the command line (*note Arguments to
-Specify the Goals: Goals.) or with the `.DEFAULT_GOAL' special variable
-(*note Other Special Variables: Special Variables.).
-
- In the simple example of the previous section, the default goal is to
-update the executable program `edit'; therefore, we put that rule first.
-
- Thus, when you give the command:
-
- make
-
-`make' reads the makefile in the current directory and begins by
-processing the first rule. In the example, this rule is for relinking
-`edit'; but before `make' can fully process this rule, it must process
-the rules for the files that `edit' depends on, which in this case are
-the object files. Each of these files is processed according to its
-own rule. These rules say to update each `.o' file by compiling its
-source file. The recompilation must be done if the source file, or any
-of the header files named as prerequisites, is more recent than the
-object file, or if the object file does not exist.
-
- The other rules are processed because their targets appear as
-prerequisites of the goal. If some other rule is not depended on by the
-goal (or anything it depends on, etc.), that rule is not processed,
-unless you tell `make' to do so (with a command such as `make clean').
-
- Before recompiling an object file, `make' considers updating its
-prerequisites, the source file and header files. This makefile does not
-specify anything to be done for them--the `.c' and `.h' files are not
-the targets of any rules--so `make' does nothing for these files. But
-`make' would update automatically generated C programs, such as those
-made by Bison or Yacc, by their own rules at this time.
-
- After recompiling whichever object files need it, `make' decides
-whether to relink `edit'. This must be done if the file `edit' does
-not exist, or if any of the object files are newer than it. If an
-object file was just recompiled, it is now newer than `edit', so `edit'
-is relinked.
-
- Thus, if we change the file `insert.c' and run `make', `make' will
-compile that file to update `insert.o', and then link `edit'. If we
-change the file `command.h' and run `make', `make' will recompile the
-object files `kbd.o', `command.o' and `files.o' and then link the file
-`edit'.
-
-
-File: make.info, Node: Variables Simplify, Next: make Deduces, Prev: How Make Works, Up: Introduction
-
-2.4 Variables Make Makefiles Simpler
-====================================
-
-In our example, we had to list all the object files twice in the rule
-for `edit' (repeated here):
-
- edit : main.o kbd.o command.o display.o \
- insert.o search.o files.o utils.o
- cc -o edit main.o kbd.o command.o display.o \
- insert.o search.o files.o utils.o
-
- Such duplication is error-prone; if a new object file is added to the
-system, we might add it to one list and forget the other. We can
-eliminate the risk and simplify the makefile by using a variable.
-"Variables" allow a text string to be defined once and substituted in
-multiple places later (*note How to Use Variables: Using Variables.).
-
- It is standard practice for every makefile to have a variable named
-`objects', `OBJECTS', `objs', `OBJS', `obj', or `OBJ' which is a list
-of all object file names. We would define such a variable `objects'
-with a line like this in the makefile:
-
- objects = main.o kbd.o command.o display.o \
- insert.o search.o files.o utils.o
-
-Then, each place we want to put a list of the object file names, we can
-substitute the variable's value by writing `$(objects)' (*note How to
-Use Variables: Using Variables.).
-
- Here is how the complete simple makefile looks when you use a
-variable for the object files:
-
- objects = main.o kbd.o command.o display.o \
- insert.o search.o files.o utils.o
-
- edit : $(objects)
- cc -o edit $(objects)
- main.o : main.c defs.h
- cc -c main.c
- kbd.o : kbd.c defs.h command.h
- cc -c kbd.c
- command.o : command.c defs.h command.h
- cc -c command.c
- display.o : display.c defs.h buffer.h
- cc -c display.c
- insert.o : insert.c defs.h buffer.h
- cc -c insert.c
- search.o : search.c defs.h buffer.h
- cc -c search.c
- files.o : files.c defs.h buffer.h command.h
- cc -c files.c
- utils.o : utils.c defs.h
- cc -c utils.c
- clean :
- rm edit $(objects)
-
-
-File: make.info, Node: make Deduces, Next: Combine By Prerequisite, Prev: Variables Simplify, Up: Introduction
-
-2.5 Letting `make' Deduce the Commands
-======================================
-
-It is not necessary to spell out the commands for compiling the
-individual C source files, because `make' can figure them out: it has an
-"implicit rule" for updating a `.o' file from a correspondingly named
-`.c' file using a `cc -c' command. For example, it will use the
-command `cc -c main.c -o main.o' to compile `main.c' into `main.o'. We
-can therefore omit the commands from the rules for the object files.
-*Note Using Implicit Rules: Implicit Rules.
-
- When a `.c' file is used automatically in this way, it is also
-automatically added to the list of prerequisites. We can therefore omit
-the `.c' files from the prerequisites, provided we omit the commands.
-
- Here is the entire example, with both of these changes, and a
-variable `objects' as suggested above:
-
- objects = main.o kbd.o command.o display.o \
- insert.o search.o files.o utils.o
-
- edit : $(objects)
- cc -o edit $(objects)
-
- main.o : defs.h
- kbd.o : defs.h command.h
- command.o : defs.h command.h
- display.o : defs.h buffer.h
- insert.o : defs.h buffer.h
- search.o : defs.h buffer.h
- files.o : defs.h buffer.h command.h
- utils.o : defs.h
-
- .PHONY : clean
- clean :
- rm edit $(objects)
-
-This is how we would write the makefile in actual practice. (The
-complications associated with `clean' are described elsewhere. See
-*Note Phony Targets::, and *Note Errors in Commands: Errors.)
-
- Because implicit rules are so convenient, they are important. You
-will see them used frequently.
-
-
-File: make.info, Node: Combine By Prerequisite, Next: Cleanup, Prev: make Deduces, Up: Introduction
-
-2.6 Another Style of Makefile
-=============================
-
-When the objects of a makefile are created only by implicit rules, an
-alternative style of makefile is possible. In this style of makefile,
-you group entries by their prerequisites instead of by their targets.
-Here is what one looks like:
-
- objects = main.o kbd.o command.o display.o \
- insert.o search.o files.o utils.o
-
- edit : $(objects)
- cc -o edit $(objects)
-
- $(objects) : defs.h
- kbd.o command.o files.o : command.h
- display.o insert.o search.o files.o : buffer.h
-
-Here `defs.h' is given as a prerequisite of all the object files;
-`command.h' and `buffer.h' are prerequisites of the specific object
-files listed for them.
-
- Whether this is better is a matter of taste: it is more compact, but
-some people dislike it because they find it clearer to put all the
-information about each target in one place.
-
-
-File: make.info, Node: Cleanup, Prev: Combine By Prerequisite, Up: Introduction
-
-2.7 Rules for Cleaning the Directory
-====================================
-
-Compiling a program is not the only thing you might want to write rules
-for. Makefiles commonly tell how to do a few other things besides
-compiling a program: for example, how to delete all the object files
-and executables so that the directory is `clean'.
-
- Here is how we could write a `make' rule for cleaning our example
-editor:
-
- clean:
- rm edit $(objects)
-
- In practice, we might want to write the rule in a somewhat more
-complicated manner to handle unanticipated situations. We would do
-this:
-
- .PHONY : clean
- clean :
- -rm edit $(objects)
-
-This prevents `make' from getting confused by an actual file called
-`clean' and causes it to continue in spite of errors from `rm'. (See
-*Note Phony Targets::, and *Note Errors in Commands: Errors.)
-
-A rule such as this should not be placed at the beginning of the
-makefile, because we do not want it to run by default! Thus, in the
-example makefile, we want the rule for `edit', which recompiles the
-editor, to remain the default goal.
-
- Since `clean' is not a prerequisite of `edit', this rule will not
-run at all if we give the command `make' with no arguments. In order
-to make the rule run, we have to type `make clean'. *Note How to Run
-`make': Running.
-
-
-File: make.info, Node: Makefiles, Next: Rules, Prev: Introduction, Up: Top
-
-3 Writing Makefiles
-*******************
-
-The information that tells `make' how to recompile a system comes from
-reading a data base called the "makefile".
-
-* Menu:
-
-* Makefile Contents:: What makefiles contain.
-* Makefile Names:: How to name your makefile.
-* Include:: How one makefile can use another makefile.
-* MAKEFILES Variable:: The environment can specify extra makefiles.
-* MAKEFILE_LIST Variable:: Discover which makefiles have been read.
-* Special Variables:: Other special variables.
-* Remaking Makefiles:: How makefiles get remade.
-* Overriding Makefiles:: How to override part of one makefile
- with another makefile.
-* Reading Makefiles:: How makefiles are parsed.
-* Secondary Expansion:: How and when secondary expansion is performed.
-
-
-File: make.info, Node: Makefile Contents, Next: Makefile Names, Prev: Makefiles, Up: Makefiles
-
-3.1 What Makefiles Contain
-==========================
-
-Makefiles contain five kinds of things: "explicit rules", "implicit
-rules", "variable definitions", "directives", and "comments". Rules,
-variables, and directives are described at length in later chapters.
-
- * An "explicit rule" says when and how to remake one or more files,
- called the rule's "targets". It lists the other files that the
- targets depend on, called the "prerequisites" of the target, and
- may also give commands to use to create or update the targets.
- *Note Writing Rules: Rules.
-
- * An "implicit rule" says when and how to remake a class of files
- based on their names. It describes how a target may depend on a
- file with a name similar to the target and gives commands to
- create or update such a target. *Note Using Implicit Rules:
- Implicit Rules.
-
- * A "variable definition" is a line that specifies a text string
- value for a variable that can be substituted into the text later.
- The simple makefile example shows a variable definition for
- `objects' as a list of all object files (*note Variables Make
- Makefiles Simpler: Variables Simplify.).
-
- * A "directive" is a command for `make' to do something special while
- reading the makefile. These include:
-
- * Reading another makefile (*note Including Other Makefiles:
- Include.).
-
- * Deciding (based on the values of variables) whether to use or
- ignore a part of the makefile (*note Conditional Parts of
- Makefiles: Conditionals.).
-
- * Defining a variable from a verbatim string containing
- multiple lines (*note Defining Variables Verbatim: Defining.).
-
- * `#' in a line of a makefile starts a "comment". It and the rest
- of the line are ignored, except that a trailing backslash not
- escaped by another backslash will continue the comment across
- multiple lines. A line containing just a comment (with perhaps
- spaces before it) is effectively blank, and is ignored. If you
- want a literal `#', escape it with a backslash (e.g., `\#').
- Comments may appear on any line in the makefile, although they are
- treated specially in certain situations.
-
- Within a command script (if the line begins with a TAB character)
- the entire line is passed to the shell, just as with any other
- line that begins with a TAB. The shell decides how to interpret
- the text: whether or not this is a comment is up to the shell.
-
- Within a `define' directive, comments are not ignored during the
- definition of the variable, but rather kept intact in the value of
- the variable. When the variable is expanded they will either be
- treated as `make' comments or as command script text, depending on
- the context in which the variable is evaluated.
-
-
-File: make.info, Node: Makefile Names, Next: Include, Prev: Makefile Contents, Up: Makefiles
-
-3.2 What Name to Give Your Makefile
-===================================
-
-By default, when `make' looks for the makefile, it tries the following
-names, in order: `GNUmakefile', `makefile' and `Makefile'.
-
- Normally you should call your makefile either `makefile' or
-`Makefile'. (We recommend `Makefile' because it appears prominently
-near the beginning of a directory listing, right near other important
-files such as `README'.) The first name checked, `GNUmakefile', is not
-recommended for most makefiles. You should use this name if you have a
-makefile that is specific to GNU `make', and will not be understood by
-other versions of `make'. Other `make' programs look for `makefile' and
-`Makefile', but not `GNUmakefile'.
-
- If `make' finds none of these names, it does not use any makefile.
-Then you must specify a goal with a command argument, and `make' will
-attempt to figure out how to remake it using only its built-in implicit
-rules. *Note Using Implicit Rules: Implicit Rules.
-
- If you want to use a nonstandard name for your makefile, you can
-specify the makefile name with the `-f' or `--file' option. The
-arguments `-f NAME' or `--file=NAME' tell `make' to read the file NAME
-as the makefile. If you use more than one `-f' or `--file' option, you
-can specify several makefiles. All the makefiles are effectively
-concatenated in the order specified. The default makefile names
-`GNUmakefile', `makefile' and `Makefile' are not checked automatically
-if you specify `-f' or `--file'.
-
-
-File: make.info, Node: Include, Next: MAKEFILES Variable, Prev: Makefile Names, Up: Makefiles
-
-3.3 Including Other Makefiles
-=============================
-
-The `include' directive tells `make' to suspend reading the current
-makefile and read one or more other makefiles before continuing. The
-directive is a line in the makefile that looks like this:
-
- include FILENAMES...
-
-FILENAMES can contain shell file name patterns. If FILENAMES is empty,
-nothing is included and no error is printed.
-
- Extra spaces are allowed and ignored at the beginning of the line,
-but a tab is not allowed. (If the line begins with a tab, it will be
-considered a command line.) Whitespace is required between `include'
-and the file names, and between file names; extra whitespace is ignored
-there and at the end of the directive. A comment starting with `#' is
-allowed at the end of the line. If the file names contain any variable
-or function references, they are expanded. *Note How to Use Variables:
-Using Variables.
-
- For example, if you have three `.mk' files, `a.mk', `b.mk', and
-`c.mk', and `$(bar)' expands to `bish bash', then the following
-expression
-
- include foo *.mk $(bar)
-
- is equivalent to
-
- include foo a.mk b.mk c.mk bish bash
-
- When `make' processes an `include' directive, it suspends reading of
-the containing makefile and reads from each listed file in turn. When
-that is finished, `make' resumes reading the makefile in which the
-directive appears.
-
- One occasion for using `include' directives is when several programs,
-handled by individual makefiles in various directories, need to use a
-common set of variable definitions (*note Setting Variables: Setting.)
-or pattern rules (*note Defining and Redefining Pattern Rules: Pattern
-Rules.).
-
- Another such occasion is when you want to generate prerequisites from
-source files automatically; the prerequisites can be put in a file that
-is included by the main makefile. This practice is generally cleaner
-than that of somehow appending the prerequisites to the end of the main
-makefile as has been traditionally done with other versions of `make'.
-*Note Automatic Prerequisites::.
-
- If the specified name does not start with a slash, and the file is
-not found in the current directory, several other directories are
-searched. First, any directories you have specified with the `-I' or
-`--include-dir' option are searched (*note Summary of Options: Options
-Summary.). Then the following directories (if they exist) are
-searched, in this order: `PREFIX/include' (normally `/usr/local/include'
-(1)) `/usr/gnu/include', `/usr/local/include', `/usr/include'.
-
- If an included makefile cannot be found in any of these directories,
-a warning message is generated, but it is not an immediately fatal
-error; processing of the makefile containing the `include' continues.
-Once it has finished reading makefiles, `make' will try to remake any
-that are out of date or don't exist. *Note How Makefiles Are Remade:
-Remaking Makefiles. Only after it has tried to find a way to remake a
-makefile and failed, will `make' diagnose the missing makefile as a
-fatal error.
-
- If you want `make' to simply ignore a makefile which does not exist
-and cannot be remade, with no error message, use the `-include'
-directive instead of `include', like this:
-
- -include FILENAMES...
-
- This acts like `include' in every way except that there is no error
-(not even a warning) if any of the FILENAMES do not exist. For
-compatibility with some other `make' implementations, `sinclude' is
-another name for `-include'.
-
- ---------- Footnotes ----------
-
- (1) GNU Make compiled for MS-DOS and MS-Windows behaves as if PREFIX
-has been defined to be the root of the DJGPP tree hierarchy.
-
-
-File: make.info, Node: MAKEFILES Variable, Next: MAKEFILE_LIST Variable, Prev: Include, Up: Makefiles
-
-3.4 The Variable `MAKEFILES'
-============================
-
-If the environment variable `MAKEFILES' is defined, `make' considers
-its value as a list of names (separated by whitespace) of additional
-makefiles to be read before the others. This works much like the
-`include' directive: various directories are searched for those files
-(*note Including Other Makefiles: Include.). In addition, the default
-goal is never taken from one of these makefiles and it is not an error
-if the files listed in `MAKEFILES' are not found.
-
- The main use of `MAKEFILES' is in communication between recursive
-invocations of `make' (*note Recursive Use of `make': Recursion.). It
-usually is not desirable to set the environment variable before a
-top-level invocation of `make', because it is usually better not to
-mess with a makefile from outside. However, if you are running `make'
-without a specific makefile, a makefile in `MAKEFILES' can do useful
-things to help the built-in implicit rules work better, such as
-defining search paths (*note Directory Search::).
-
- Some users are tempted to set `MAKEFILES' in the environment
-automatically on login, and program makefiles to expect this to be done.
-This is a very bad idea, because such makefiles will fail to work if
-run by anyone else. It is much better to write explicit `include'
-directives in the makefiles. *Note Including Other Makefiles: Include.
-
-
-File: make.info, Node: MAKEFILE_LIST Variable, Next: Special Variables, Prev: MAKEFILES Variable, Up: Makefiles
-
-3.5 The Variable `MAKEFILE_LIST'
-================================
-
-As `make' reads various makefiles, including any obtained from the
-`MAKEFILES' variable, the command line, the default files, or from
-`include' directives, their names will be automatically appended to the
-`MAKEFILE_LIST' variable. They are added right before `make' begins to
-parse them.
-
- This means that if the first thing a makefile does is examine the
-last word in this variable, it will be the name of the current makefile.
-Once the current makefile has used `include', however, the last word
-will be the just-included makefile.
-
- If a makefile named `Makefile' has this content:
-
- name1 := $(lastword $(MAKEFILE_LIST))
-
- include inc.mk
-
- name2 := $(lastword $(MAKEFILE_LIST))
-
- all:
- @echo name1 = $(name1)
- @echo name2 = $(name2)
-
-then you would expect to see this output:
-
- name1 = Makefile
- name2 = inc.mk
-
- *Note Text Functions::, for more information on the `word' and
-`words' functions used above. *Note The Two Flavors of Variables:
-Flavors, for more information on simply-expanded (`:=') variable
-definitions.
-
-
-File: make.info, Node: Special Variables, Next: Remaking Makefiles, Prev: MAKEFILE_LIST Variable, Up: Makefiles
-
-3.6 Other Special Variables
-===========================
-
-GNU `make' also supports other special variables. Unless otherwise
-documented here, these values lose their special properties if they are
-set by a makefile or on the command line.
-
-`.DEFAULT_GOAL'
- Sets the default goal to be used if no targets were specified on
- the command line (*note Arguments to Specify the Goals: Goals.).
- The `.DEFAULT_GOAL' variable allows you to discover the current
- default goal, restart the default goal selection algorithm by
- clearing its value, or to explicitly set the default goal. The
- following example illustrates these cases:
-
- # Query the default goal.
- ifeq ($(.DEFAULT_GOAL),)
- $(warning no default goal is set)
- endif
-
- .PHONY: foo
- foo: ; @echo $@
-
- $(warning default goal is $(.DEFAULT_GOAL))
-
- # Reset the default goal.
- .DEFAULT_GOAL :=
-
- .PHONY: bar
- bar: ; @echo $@
-
- $(warning default goal is $(.DEFAULT_GOAL))
-
- # Set our own.
- .DEFAULT_GOAL := foo
-
- This makefile prints:
-
- no default goal is set
- default goal is foo
- default goal is bar
- foo
-
- Note that assigning more than one target name to `.DEFAULT_GOAL' is
- illegal and will result in an error.
-
-`MAKE_RESTARTS'
- This variable is set only if this instance of `make' has restarted
- (*note How Makefiles Are Remade: Remaking Makefiles.): it will
- contain the number of times this instance has restarted. Note
- this is not the same as recursion (counted by the `MAKELEVEL'
- variable). You should not set, modify, or export this variable.
-
-`.VARIABLES'
- Expands to a list of the _names_ of all global variables defined
- so far. This includes variables which have empty values, as well
- as built-in variables (*note Variables Used by Implicit Rules:
- Implicit Variables.), but does not include any variables which are
- only defined in a target-specific context. Note that any value
- you assign to this variable will be ignored; it will always return
- its special value.
-
-`.FEATURES'
- Expands to a list of special features supported by this version of
- `make'. Possible values include:
-
- `archives'
- Supports `ar' (archive) files using special filename syntax.
- *Note Using `make' to Update Archive Files: Archives.
-
- `check-symlink'
- Supports the `-L' (`--check-symlink-times') flag. *Note
- Summary of Options: Options Summary.
-
- `else-if'
- Supports "else if" non-nested conditionals. *Note Syntax of
- Conditionals: Conditional Syntax.
-
- `jobserver'
- Supports "job server" enhanced parallel builds. *Note
- Parallel Execution: Parallel.
-
- `second-expansion'
- Supports secondary expansion of prerequisite lists.
-
- `order-only'
- Supports order-only prerequisites. *Note Types of
- Prerequisites: Prerequisite Types.
-
- `target-specific'
- Supports target-specific and pattern-specific variable
- assignments. *Note Target-specific Variable Values:
- Target-specific.
-
-
-`.INCLUDE_DIRS'
- Expands to a list of directories that `make' searches for included
- makefiles (*note Including Other Makefiles: Include.).
-
-
-
-File: make.info, Node: Remaking Makefiles, Next: Overriding Makefiles, Prev: Special Variables, Up: Makefiles
-
-3.7 How Makefiles Are Remade
-============================
-
-Sometimes makefiles can be remade from other files, such as RCS or SCCS
-files. If a makefile can be remade from other files, you probably want
-`make' to get an up-to-date version of the makefile to read in.
-
- To this end, after reading in all makefiles, `make' will consider
-each as a goal target and attempt to update it. If a makefile has a
-rule which says how to update it (found either in that very makefile or
-in another one) or if an implicit rule applies to it (*note Using
-Implicit Rules: Implicit Rules.), it will be updated if necessary.
-After all makefiles have been checked, if any have actually been
-changed, `make' starts with a clean slate and reads all the makefiles
-over again. (It will also attempt to update each of them over again,
-but normally this will not change them again, since they are already up
-to date.)
-
- If you know that one or more of your makefiles cannot be remade and
-you want to keep `make' from performing an implicit rule search on
-them, perhaps for efficiency reasons, you can use any normal method of
-preventing implicit rule lookup to do so. For example, you can write an
-explicit rule with the makefile as the target, and an empty command
-string (*note Using Empty Commands: Empty Commands.).
-
- If the makefiles specify a double-colon rule to remake a file with
-commands but no prerequisites, that file will always be remade (*note
-Double-Colon::). In the case of makefiles, a makefile that has a
-double-colon rule with commands but no prerequisites will be remade
-every time `make' is run, and then again after `make' starts over and
-reads the makefiles in again. This would cause an infinite loop:
-`make' would constantly remake the makefile, and never do anything
-else. So, to avoid this, `make' will *not* attempt to remake makefiles
-which are specified as targets of a double-colon rule with commands but
-no prerequisites.
-
- If you do not specify any makefiles to be read with `-f' or `--file'
-options, `make' will try the default makefile names; *note What Name to
-Give Your Makefile: Makefile Names. Unlike makefiles explicitly
-requested with `-f' or `--file' options, `make' is not certain that
-these makefiles should exist. However, if a default makefile does not
-exist but can be created by running `make' rules, you probably want the
-rules to be run so that the makefile can be used.
-
- Therefore, if none of the default makefiles exists, `make' will try
-to make each of them in the same order in which they are searched for
-(*note What Name to Give Your Makefile: Makefile Names.) until it
-succeeds in making one, or it runs out of names to try. Note that it
-is not an error if `make' cannot find or make any makefile; a makefile
-is not always necessary.
-
- When you use the `-t' or `--touch' option (*note Instead of
-Executing the Commands: Instead of Execution.), you would not want to
-use an out-of-date makefile to decide which targets to touch. So the
-`-t' option has no effect on updating makefiles; they are really
-updated even if `-t' is specified. Likewise, `-q' (or `--question')
-and `-n' (or `--just-print') do not prevent updating of makefiles,
-because an out-of-date makefile would result in the wrong output for
-other targets. Thus, `make -f mfile -n foo' will update `mfile', read
-it in, and then print the commands to update `foo' and its prerequisites
-without running them. The commands printed for `foo' will be those
-specified in the updated contents of `mfile'.
-
- However, on occasion you might actually wish to prevent updating of
-even the makefiles. You can do this by specifying the makefiles as
-goals in the command line as well as specifying them as makefiles.
-When the makefile name is specified explicitly as a goal, the options
-`-t' and so on do apply to them.
-
- Thus, `make -f mfile -n mfile foo' would read the makefile `mfile',
-print the commands needed to update it without actually running them,
-and then print the commands needed to update `foo' without running
-them. The commands for `foo' will be those specified by the existing
-contents of `mfile'.
-
-
-File: make.info, Node: Overriding Makefiles, Next: Reading Makefiles, Prev: Remaking Makefiles, Up: Makefiles
-
-3.8 Overriding Part of Another Makefile
-=======================================
-
-Sometimes it is useful to have a makefile that is mostly just like
-another makefile. You can often use the `include' directive to include
-one in the other, and add more targets or variable definitions.
-However, if the two makefiles give different commands for the same
-target, `make' will not let you just do this. But there is another way.
-
- In the containing makefile (the one that wants to include the other),
-you can use a match-anything pattern rule to say that to remake any
-target that cannot be made from the information in the containing
-makefile, `make' should look in another makefile. *Note Pattern
-Rules::, for more information on pattern rules.
-
- For example, if you have a makefile called `Makefile' that says how
-to make the target `foo' (and other targets), you can write a makefile
-called `GNUmakefile' that contains:
-
- foo:
- frobnicate > foo
-
- %: force
- @$(MAKE) -f Makefile $@
- force: ;
-
- If you say `make foo', `make' will find `GNUmakefile', read it, and
-see that to make `foo', it needs to run the command `frobnicate > foo'.
-If you say `make bar', `make' will find no way to make `bar' in
-`GNUmakefile', so it will use the commands from the pattern rule: `make
--f Makefile bar'. If `Makefile' provides a rule for updating `bar',
-`make' will apply the rule. And likewise for any other target that
-`GNUmakefile' does not say how to make.
-
- The way this works is that the pattern rule has a pattern of just
-`%', so it matches any target whatever. The rule specifies a
-prerequisite `force', to guarantee that the commands will be run even
-if the target file already exists. We give `force' target empty
-commands to prevent `make' from searching for an implicit rule to build
-it--otherwise it would apply the same match-anything rule to `force'
-itself and create a prerequisite loop!
-
-
-File: make.info, Node: Reading Makefiles, Next: Secondary Expansion, Prev: Overriding Makefiles, Up: Makefiles
-
-3.9 How `make' Reads a Makefile
-===============================
-
-GNU `make' does its work in two distinct phases. During the first
-phase it reads all the makefiles, included makefiles, etc. and
-internalizes all the variables and their values, implicit and explicit
-rules, and constructs a dependency graph of all the targets and their
-prerequisites. During the second phase, `make' uses these internal
-structures to determine what targets will need to be rebuilt and to
-invoke the rules necessary to do so.
-
- It's important to understand this two-phase approach because it has a
-direct impact on how variable and function expansion happens; this is
-often a source of some confusion when writing makefiles. Here we will
-present a summary of the phases in which expansion happens for different
-constructs within the makefile. We say that expansion is "immediate"
-if it happens during the first phase: in this case `make' will expand
-any variables or functions in that section of a construct as the
-makefile is parsed. We say that expansion is "deferred" if expansion
-is not performed immediately. Expansion of deferred construct is not
-performed until either the construct appears later in an immediate
-context, or until the second phase.
-
- You may not be familiar with some of these constructs yet. You can
-reference this section as you become familiar with them, in later
-chapters.
-
-Variable Assignment
--------------------
-
-Variable definitions are parsed as follows:
-
- IMMEDIATE = DEFERRED
- IMMEDIATE ?= DEFERRED
- IMMEDIATE := IMMEDIATE
- IMMEDIATE += DEFERRED or IMMEDIATE
-
- define IMMEDIATE
- DEFERRED
- endef
-
- For the append operator, `+=', the right-hand side is considered
-immediate if the variable was previously set as a simple variable
-(`:='), and deferred otherwise.
-
-Conditional Statements
-----------------------
-
-All instances of conditional syntax are parsed immediately, in their
-entirety; this includes the `ifdef', `ifeq', `ifndef', and `ifneq'
-forms. Of course this means that automatic variables cannot be used in
-conditional statements, as automatic variables are not set until the
-command script for that rule is invoked. If you need to use automatic
-variables in a conditional you _must_ use shell conditional syntax, in
-your command script proper, for these tests, not `make' conditionals.
-
-Rule Definition
----------------
-
-A rule is always expanded the same way, regardless of the form:
-
- IMMEDIATE : IMMEDIATE ; DEFERRED
- DEFERRED
-
- That is, the target and prerequisite sections are expanded
-immediately, and the commands used to construct the target are always
-deferred. This general rule is true for explicit rules, pattern rules,
-suffix rules, static pattern rules, and simple prerequisite definitions.
-
-
-File: make.info, Node: Secondary Expansion, Prev: Reading Makefiles, Up: Makefiles
-
-3.10 Secondary Expansion
-========================
-
-In the previous section we learned that GNU `make' works in two
-distinct phases: a read-in phase and a target-update phase (*note How
-`make' Reads a Makefile: Reading Makefiles.). GNU make also has the
-ability to enable a _second expansion_ of the prerequisites (only) for
-some or all targets defined in the makefile. In order for this second
-expansion to occur, the special target `.SECONDEXPANSION' must be
-defined before the first prerequisite list that makes use of this
-feature.
-
- If that special target is defined then in between the two phases
-mentioned above, right at the end of the read-in phase, all the
-prerequisites of the targets defined after the special target are
-expanded a _second time_. In most circumstances this secondary
-expansion will have no effect, since all variable and function
-references will have been expanded during the initial parsing of the
-makefiles. In order to take advantage of the secondary expansion phase
-of the parser, then, it's necessary to _escape_ the variable or
-function reference in the makefile. In this case the first expansion
-merely un-escapes the reference but doesn't expand it, and expansion is
-left to the secondary expansion phase. For example, consider this
-makefile:
-
- .SECONDEXPANSION:
- ONEVAR = onefile
- TWOVAR = twofile
- myfile: $(ONEVAR) $$(TWOVAR)
-
- After the first expansion phase the prerequisites list of the
-`myfile' target will be `onefile' and `$(TWOVAR)'; the first
-(unescaped) variable reference to ONEVAR is expanded, while the second
-(escaped) variable reference is simply unescaped, without being
-recognized as a variable reference. Now during the secondary expansion
-the first word is expanded again but since it contains no variable or
-function references it remains the static value `onefile', while the
-second word is now a normal reference to the variable TWOVAR, which is
-expanded to the value `twofile'. The final result is that there are
-two prerequisites, `onefile' and `twofile'.
-
- Obviously, this is not a very interesting case since the same result
-could more easily have been achieved simply by having both variables
-appear, unescaped, in the prerequisites list. One difference becomes
-apparent if the variables are reset; consider this example:
-
- .SECONDEXPANSION:
- AVAR = top
- onefile: $(AVAR)
- twofile: $$(AVAR)
- AVAR = bottom
-
- Here the prerequisite of `onefile' will be expanded immediately, and
-resolve to the value `top', while the prerequisite of `twofile' will
-not be full expanded until the secondary expansion and yield a value of
-`bottom'.
-
- This is marginally more exciting, but the true power of this feature
-only becomes apparent when you discover that secondary expansions
-always take place within the scope of the automatic variables for that
-target. This means that you can use variables such as `$@', `$*', etc.
-during the second expansion and they will have their expected values,
-just as in the command script. All you have to do is defer the
-expansion by escaping the `$'. Also, secondary expansion occurs for
-both explicit and implicit (pattern) rules. Knowing this, the possible
-uses for this feature increase dramatically. For example:
-
- .SECONDEXPANSION:
- main_OBJS := main.o try.o test.o
- lib_OBJS := lib.o api.o
-
- main lib: $$($$@_OBJS)
-
- Here, after the initial expansion the prerequisites of both the
-`main' and `lib' targets will be `$($@_OBJS)'. During the secondary
-expansion, the `$@' variable is set to the name of the target and so
-the expansion for the `main' target will yield `$(main_OBJS)', or
-`main.o try.o test.o', while the secondary expansion for the `lib'
-target will yield `$(lib_OBJS)', or `lib.o api.o'.
-
- You can also mix functions here, as long as they are properly
-escaped:
-
- main_SRCS := main.c try.c test.c
- lib_SRCS := lib.c api.c
-
- .SECONDEXPANSION:
- main lib: $$(patsubst %.c,%.o,$$($$@_SRCS))
-
- This version allows users to specify source files rather than object
-files, but gives the same resulting prerequisites list as the previous
-example.
-
- Evaluation of automatic variables during the secondary expansion
-phase, especially of the target name variable `$$@', behaves similarly
-to evaluation within command scripts. However, there are some subtle
-differences and "corner cases" which come into play for the different
-types of rule definitions that `make' understands. The subtleties of
-using the different automatic variables are described below.
-
-Secondary Expansion of Explicit Rules
--------------------------------------
-
-During the secondary expansion of explicit rules, `$$@' and `$$%'
-evaluate, respectively, to the file name of the target and, when the
-target is an archive member, the target member name. The `$$<'
-variable evaluates to the first prerequisite in the first rule for this
-target. `$$^' and `$$+' evaluate to the list of all prerequisites of
-rules _that have already appeared_ for the same target (`$$+' with
-repetitions and `$$^' without). The following example will help
-illustrate these behaviors:
-
- .SECONDEXPANSION:
-
- foo: foo.1 bar.1 $$< $$^ $$+ # line #1
-
- foo: foo.2 bar.2 $$< $$^ $$+ # line #2
-
- foo: foo.3 bar.3 $$< $$^ $$+ # line #3
-
- In the first prerequisite list, all three variables (`$$<', `$$^',
-and `$$+') expand to the empty string. In the second, they will have
-values `foo.1', `foo.1 bar.1', and `foo.1 bar.1' respectively. In the
-third they will have values `foo.1', `foo.1 bar.1 foo.2 bar.2', and
-`foo.1 bar.1 foo.2 bar.2' respectively.
-
- Rules undergo secondary expansion in makefile order, except that the
-rule with the command script is always evaluated last.
-
- The variables `$$?' and `$$*' are not available and expand to the
-empty string.
-
-Secondary Expansion of Static Pattern Rules
--------------------------------------------
-
-Rules for secondary expansion of static pattern rules are identical to
-those for explicit rules, above, with one exception: for static pattern
-rules the `$$*' variable is set to the pattern stem. As with explicit
-rules, `$$?' is not available and expands to the empty string.
-
-Secondary Expansion of Implicit Rules
--------------------------------------
-
-As `make' searches for an implicit rule, it substitutes the stem and
-then performs secondary expansion for every rule with a matching target
-pattern. The value of the automatic variables is derived in the same
-fashion as for static pattern rules. As an example:
-
- .SECONDEXPANSION:
-
- foo: bar
-
- foo foz: fo%: bo%
-
- %oo: $$< $$^ $$+ $$*
-
- When the implicit rule is tried for target `foo', `$$<' expands to
-`bar', `$$^' expands to `bar boo', `$$+' also expands to `bar boo', and
-`$$*' expands to `f'.
-
- Note that the directory prefix (D), as described in *Note Implicit
-Rule Search Algorithm: Implicit Rule Search, is appended (after
-expansion) to all the patterns in the prerequisites list. As an
-example:
-
- .SECONDEXPANSION:
-
- /tmp/foo.o:
-
- %.o: $$(addsuffix /%.c,foo bar) foo.h
-
- The prerequisite list after the secondary expansion and directory
-prefix reconstruction will be `/tmp/foo/foo.c /tmp/var/bar/foo.c
-foo.h'. If you are not interested in this reconstruction, you can use
-`$$*' instead of `%' in the prerequisites list.
-
-
-File: make.info, Node: Rules, Next: Commands, Prev: Makefiles, Up: Top
-
-4 Writing Rules
-***************
-
-A "rule" appears in the makefile and says when and how to remake
-certain files, called the rule's "targets" (most often only one per
-rule). It lists the other files that are the "prerequisites" of the
-target, and "commands" to use to create or update the target.
-
- The order of rules is not significant, except for determining the
-"default goal": the target for `make' to consider, if you do not
-otherwise specify one. The default goal is the target of the first
-rule in the first makefile. If the first rule has multiple targets,
-only the first target is taken as the default. There are two
-exceptions: a target starting with a period is not a default unless it
-contains one or more slashes, `/', as well; and, a target that defines
-a pattern rule has no effect on the default goal. (*Note Defining and
-Redefining Pattern Rules: Pattern Rules.)
-
- Therefore, we usually write the makefile so that the first rule is
-the one for compiling the entire program or all the programs described
-by the makefile (often with a target called `all'). *Note Arguments to
-Specify the Goals: Goals.
-
-* Menu:
-
-* Rule Example:: An example explained.
-* Rule Syntax:: General syntax explained.
-* Prerequisite Types:: There are two types of prerequisites.
-* Wildcards:: Using wildcard characters such as `*'.
-* Directory Search:: Searching other directories for source files.
-* Phony Targets:: Using a target that is not a real file's name.
-* Force Targets:: You can use a target without commands
- or prerequisites to mark other targets
- as phony.
-* Empty Targets:: When only the date matters and the
- files are empty.
-* Special Targets:: Targets with special built-in meanings.
-* Multiple Targets:: When to make use of several targets in a rule.
-* Multiple Rules:: How to use several rules with the same target.
-* Static Pattern:: Static pattern rules apply to multiple targets
- and can vary the prerequisites according to
- the target name.
-* Double-Colon:: How to use a special kind of rule to allow
- several independent rules for one target.
-* Automatic Prerequisites:: How to automatically generate rules giving
- prerequisites from source files themselves.
-
-
-File: make.info, Node: Rule Example, Next: Rule Syntax, Prev: Rules, Up: Rules
-
-4.1 Rule Example
-================
-
-Here is an example of a rule:
-
- foo.o : foo.c defs.h # module for twiddling the frobs
- cc -c -g foo.c
-
- Its target is `foo.o' and its prerequisites are `foo.c' and
-`defs.h'. It has one command, which is `cc -c -g foo.c'. The command
-line starts with a tab to identify it as a command.
-
- This rule says two things:
-
- * How to decide whether `foo.o' is out of date: it is out of date if
- it does not exist, or if either `foo.c' or `defs.h' is more recent
- than it.
-
- * How to update the file `foo.o': by running `cc' as stated. The
- command does not explicitly mention `defs.h', but we presume that
- `foo.c' includes it, and that that is why `defs.h' was added to
- the prerequisites.
-
-
-File: make.info, Node: Rule Syntax, Next: Prerequisite Types, Prev: Rule Example, Up: Rules
-
-4.2 Rule Syntax
-===============
-
-In general, a rule looks like this:
-
- TARGETS : PREREQUISITES
- COMMAND
- ...
-
-or like this:
-
- TARGETS : PREREQUISITES ; COMMAND
- COMMAND
- ...
-
- The TARGETS are file names, separated by spaces. Wildcard
-characters may be used (*note Using Wildcard Characters in File Names:
-Wildcards.) and a name of the form `A(M)' represents member M in
-archive file A (*note Archive Members as Targets: Archive Members.).
-Usually there is only one target per rule, but occasionally there is a
-reason to have more (*note Multiple Targets in a Rule: Multiple
-Targets.).
-
- The COMMAND lines start with a tab character. The first command may
-appear on the line after the prerequisites, with a tab character, or may
-appear on the same line, with a semicolon. Either way, the effect is
-the same. There are other differences in the syntax of command lines.
-*Note Writing the Commands in Rules: Commands.
-
- Because dollar signs are used to start `make' variable references,
-if you really want a dollar sign in a target or prerequisite you must
-write two of them, `$$' (*note How to Use Variables: Using Variables.).
-If you have enabled secondary expansion (*note Secondary Expansion::)
-and you want a literal dollar sign in the prerequisites lise, you must
-actually write _four_ dollar signs (`$$$$').
-
- You may split a long line by inserting a backslash followed by a
-newline, but this is not required, as `make' places no limit on the
-length of a line in a makefile.
-
- A rule tells `make' two things: when the targets are out of date,
-and how to update them when necessary.
-
- The criterion for being out of date is specified in terms of the
-PREREQUISITES, which consist of file names separated by spaces.
-(Wildcards and archive members (*note Archives::) are allowed here too.)
-A target is out of date if it does not exist or if it is older than any
-of the prerequisites (by comparison of last-modification times). The
-idea is that the contents of the target file are computed based on
-information in the prerequisites, so if any of the prerequisites
-changes, the contents of the existing target file are no longer
-necessarily valid.
-
- How to update is specified by COMMANDS. These are lines to be
-executed by the shell (normally `sh'), but with some extra features
-(*note Writing the Commands in Rules: Commands.).
-
-
-File: make.info, Node: Prerequisite Types, Next: Wildcards, Prev: Rule Syntax, Up: Rules
-
-4.3 Types of Prerequisites
-==========================
-
-There are actually two different types of prerequisites understood by
-GNU `make': normal prerequisites such as described in the previous
-section, and "order-only" prerequisites. A normal prerequisite makes
-two statements: first, it imposes an order of execution of build
-commands: any commands necessary to build any of a target's
-prerequisites will be fully executed before any commands necessary to
-build the target. Second, it imposes a dependency relationship: if any
-prerequisite is newer than the target, then the target is considered
-out-of-date and must be rebuilt.
-
- Normally, this is exactly what you want: if a target's prerequisite
-is updated, then the target should also be updated.
-
- Occasionally, however, you have a situation where you want to impose
-a specific ordering on the rules to be invoked _without_ forcing the
-target to be updated if one of those rules is executed. In that case,
-you want to define "order-only" prerequisites. Order-only
-prerequisites can be specified by placing a pipe symbol (`|') in the
-prerequisites list: any prerequisites to the left of the pipe symbol
-are normal; any prerequisites to the right are order-only:
-
- TARGETS : NORMAL-PREREQUISITES | ORDER-ONLY-PREREQUISITES
-
- The normal prerequisites section may of course be empty. Also, you
-may still declare multiple lines of prerequisites for the same target:
-they are appended appropriately. Note that if you declare the same
-file to be both a normal and an order-only prerequisite, the normal
-prerequisite takes precedence (since they are a strict superset of the
-behavior of an order-only prerequisite).
-
-
-File: make.info, Node: Wildcards, Next: Directory Search, Prev: Prerequisite Types, Up: Rules
-
-4.4 Using Wildcard Characters in File Names
-===========================================
-
-A single file name can specify many files using "wildcard characters".
-The wildcard characters in `make' are `*', `?' and `[...]', the same as
-in the Bourne shell. For example, `*.c' specifies a list of all the
-files (in the working directory) whose names end in `.c'.
-
- The character `~' at the beginning of a file name also has special
-significance. If alone, or followed by a slash, it represents your home
-directory. For example `~/bin' expands to `/home/you/bin'. If the `~'
-is followed by a word, the string represents the home directory of the
-user named by that word. For example `~john/bin' expands to
-`/home/john/bin'. On systems which don't have a home directory for
-each user (such as MS-DOS or MS-Windows), this functionality can be
-simulated by setting the environment variable HOME.
-
- Wildcard expansion is performed by `make' automatically in targets
-and in prerequisites. In commands the shell is responsible for
-wildcard expansion. In other contexts, wildcard expansion happens only
-if you request it explicitly with the `wildcard' function.
-
- The special significance of a wildcard character can be turned off by
-preceding it with a backslash. Thus, `foo\*bar' would refer to a
-specific file whose name consists of `foo', an asterisk, and `bar'.
-
-* Menu:
-
-* Wildcard Examples:: Several examples
-* Wildcard Pitfall:: Problems to avoid.
-* Wildcard Function:: How to cause wildcard expansion where
- it does not normally take place.
-
-
-File: make.info, Node: Wildcard Examples, Next: Wildcard Pitfall, Prev: Wildcards, Up: Wildcards
-
-4.4.1 Wildcard Examples
------------------------
-
-Wildcards can be used in the commands of a rule, where they are expanded
-by the shell. For example, here is a rule to delete all the object
-files:
-
- clean:
- rm -f *.o
-
- Wildcards are also useful in the prerequisites of a rule. With the
-following rule in the makefile, `make print' will print all the `.c'
-files that have changed since the last time you printed them:
-
- print: *.c
- lpr -p $?
- touch print
-
-This rule uses `print' as an empty target file; see *Note Empty Target
-Files to Record Events: Empty Targets. (The automatic variable `$?' is
-used to print only those files that have changed; see *Note Automatic
-Variables::.)
-
- Wildcard expansion does not happen when you define a variable.
-Thus, if you write this:
-
- objects = *.o
-
-then the value of the variable `objects' is the actual string `*.o'.
-However, if you use the value of `objects' in a target, prerequisite or
-command, wildcard expansion will take place at that time. To set
-`objects' to the expansion, instead use:
-
- objects := $(wildcard *.o)
-
-*Note Wildcard Function::.
-
-
-File: make.info, Node: Wildcard Pitfall, Next: Wildcard Function, Prev: Wildcard Examples, Up: Wildcards
-
-4.4.2 Pitfalls of Using Wildcards
----------------------------------
-
-Now here is an example of a naive way of using wildcard expansion, that
-does not do what you would intend. Suppose you would like to say that
-the executable file `foo' is made from all the object files in the
-directory, and you write this:
-
- objects = *.o
-
- foo : $(objects)
- cc -o foo $(CFLAGS) $(objects)
-
-The value of `objects' is the actual string `*.o'. Wildcard expansion
-happens in the rule for `foo', so that each _existing_ `.o' file
-becomes a prerequisite of `foo' and will be recompiled if necessary.
-
- But what if you delete all the `.o' files? When a wildcard matches
-no files, it is left as it is, so then `foo' will depend on the
-oddly-named file `*.o'. Since no such file is likely to exist, `make'
-will give you an error saying it cannot figure out how to make `*.o'.
-This is not what you want!
-
- Actually it is possible to obtain the desired result with wildcard
-expansion, but you need more sophisticated techniques, including the
-`wildcard' function and string substitution. *Note The Function
-`wildcard': Wildcard Function.
-
- Microsoft operating systems (MS-DOS and MS-Windows) use backslashes
-to separate directories in pathnames, like so:
-
- c:\foo\bar\baz.c
-
- This is equivalent to the Unix-style `c:/foo/bar/baz.c' (the `c:'
-part is the so-called drive letter). When `make' runs on these
-systems, it supports backslashes as well as the Unix-style forward
-slashes in pathnames. However, this support does _not_ include the
-wildcard expansion, where backslash is a quote character. Therefore,
-you _must_ use Unix-style slashes in these cases.
-
-
-File: make.info, Node: Wildcard Function, Prev: Wildcard Pitfall, Up: Wildcards
-
-4.4.3 The Function `wildcard'
------------------------------
-
-Wildcard expansion happens automatically in rules. But wildcard
-expansion does not normally take place when a variable is set, or
-inside the arguments of a function. If you want to do wildcard
-expansion in such places, you need to use the `wildcard' function, like
-this:
-
- $(wildcard PATTERN...)
-
-This string, used anywhere in a makefile, is replaced by a
-space-separated list of names of existing files that match one of the
-given file name patterns. If no existing file name matches a pattern,
-then that pattern is omitted from the output of the `wildcard'
-function. Note that this is different from how unmatched wildcards
-behave in rules, where they are used verbatim rather than ignored
-(*note Wildcard Pitfall::).
-
- One use of the `wildcard' function is to get a list of all the C
-source files in a directory, like this:
-
- $(wildcard *.c)
-
- We can change the list of C source files into a list of object files
-by replacing the `.c' suffix with `.o' in the result, like this:
-
- $(patsubst %.c,%.o,$(wildcard *.c))
-
-(Here we have used another function, `patsubst'. *Note Functions for
-String Substitution and Analysis: Text Functions.)
-
- Thus, a makefile to compile all C source files in the directory and
-then link them together could be written as follows:
-
- objects := $(patsubst %.c,%.o,$(wildcard *.c))
-
- foo : $(objects)
- cc -o foo $(objects)
-
-(This takes advantage of the implicit rule for compiling C programs, so
-there is no need to write explicit rules for compiling the files.
-*Note The Two Flavors of Variables: Flavors, for an explanation of
-`:=', which is a variant of `='.)
-
-
-File: make.info, Node: Directory Search, Next: Phony Targets, Prev: Wildcards, Up: Rules
-
-4.5 Searching Directories for Prerequisites
-===========================================
-
-For large systems, it is often desirable to put sources in a separate
-directory from the binaries. The "directory search" features of `make'
-facilitate this by searching several directories automatically to find
-a prerequisite. When you redistribute the files among directories, you
-do not need to change the individual rules, just the search paths.
-
-* Menu:
-
-* General Search:: Specifying a search path that applies
- to every prerequisite.
-* Selective Search:: Specifying a search path
- for a specified class of names.
-* Search Algorithm:: When and how search paths are applied.
-* Commands/Search:: How to write shell commands that work together
- with search paths.
-* Implicit/Search:: How search paths affect implicit rules.
-* Libraries/Search:: Directory search for link libraries.
-
-
-File: make.info, Node: General Search, Next: Selective Search, Prev: Directory Search, Up: Directory Search
-
-4.5.1 `VPATH': Search Path for All Prerequisites
-------------------------------------------------
-
-The value of the `make' variable `VPATH' specifies a list of
-directories that `make' should search. Most often, the directories are
-expected to contain prerequisite files that are not in the current
-directory; however, `make' uses `VPATH' as a search list for both
-prerequisites and targets of rules.
-
- Thus, if a file that is listed as a target or prerequisite does not
-exist in the current directory, `make' searches the directories listed
-in `VPATH' for a file with that name. If a file is found in one of
-them, that file may become the prerequisite (see below). Rules may then
-specify the names of files in the prerequisite list as if they all
-existed in the current directory. *Note Writing Shell Commands with
-Directory Search: Commands/Search.
-
- In the `VPATH' variable, directory names are separated by colons or
-blanks. The order in which directories are listed is the order followed
-by `make' in its search. (On MS-DOS and MS-Windows, semi-colons are
-used as separators of directory names in `VPATH', since the colon can
-be used in the pathname itself, after the drive letter.)
-
- For example,
-
- VPATH = src:../headers
-
-specifies a path containing two directories, `src' and `../headers',
-which `make' searches in that order.
-
- With this value of `VPATH', the following rule,
-
- foo.o : foo.c
-
-is interpreted as if it were written like this:
-
- foo.o : src/foo.c
-
-assuming the file `foo.c' does not exist in the current directory but
-is found in the directory `src'.
-
-
-File: make.info, Node: Selective Search, Next: Search Algorithm, Prev: General Search, Up: Directory Search
-
-4.5.2 The `vpath' Directive
----------------------------
-
-Similar to the `VPATH' variable, but more selective, is the `vpath'
-directive (note lower case), which allows you to specify a search path
-for a particular class of file names: those that match a particular
-pattern. Thus you can supply certain search directories for one class
-of file names and other directories (or none) for other file names.
-
- There are three forms of the `vpath' directive:
-
-`vpath PATTERN DIRECTORIES'
- Specify the search path DIRECTORIES for file names that match
- PATTERN.
-
- The search path, DIRECTORIES, is a list of directories to be
- searched, separated by colons (semi-colons on MS-DOS and
- MS-Windows) or blanks, just like the search path used in the
- `VPATH' variable.
-
-`vpath PATTERN'
- Clear out the search path associated with PATTERN.
-
-`vpath'
- Clear all search paths previously specified with `vpath'
- directives.
-
- A `vpath' pattern is a string containing a `%' character. The
-string must match the file name of a prerequisite that is being searched
-for, the `%' character matching any sequence of zero or more characters
-(as in pattern rules; *note Defining and Redefining Pattern Rules:
-Pattern Rules.). For example, `%.h' matches files that end in `.h'.
-(If there is no `%', the pattern must match the prerequisite exactly,
-which is not useful very often.)
-
- `%' characters in a `vpath' directive's pattern can be quoted with
-preceding backslashes (`\'). Backslashes that would otherwise quote
-`%' characters can be quoted with more backslashes. Backslashes that
-quote `%' characters or other backslashes are removed from the pattern
-before it is compared to file names. Backslashes that are not in
-danger of quoting `%' characters go unmolested.
-
- When a prerequisite fails to exist in the current directory, if the
-PATTERN in a `vpath' directive matches the name of the prerequisite
-file, then the DIRECTORIES in that directive are searched just like
-(and before) the directories in the `VPATH' variable.
-
- For example,
-
- vpath %.h ../headers
-
-tells `make' to look for any prerequisite whose name ends in `.h' in
-the directory `../headers' if the file is not found in the current
-directory.
-
- If several `vpath' patterns match the prerequisite file's name, then
-`make' processes each matching `vpath' directive one by one, searching
-all the directories mentioned in each directive. `make' handles
-multiple `vpath' directives in the order in which they appear in the
-makefile; multiple directives with the same pattern are independent of
-each other.
-
- Thus,
-
- vpath %.c foo
- vpath % blish
- vpath %.c bar
-
-will look for a file ending in `.c' in `foo', then `blish', then `bar',
-while
-
- vpath %.c foo:bar
- vpath % blish
-
-will look for a file ending in `.c' in `foo', then `bar', then `blish'.
-
-
-File: make.info, Node: Search Algorithm, Next: Commands/Search, Prev: Selective Search, Up: Directory Search
-
-4.5.3 How Directory Searches are Performed
-------------------------------------------
-
-When a prerequisite is found through directory search, regardless of
-type (general or selective), the pathname located may not be the one
-that `make' actually provides you in the prerequisite list. Sometimes
-the path discovered through directory search is thrown away.
-
- The algorithm `make' uses to decide whether to keep or abandon a
-path found via directory search is as follows:
-
- 1. If a target file does not exist at the path specified in the
- makefile, directory search is performed.
-
- 2. If the directory search is successful, that path is kept and this
- file is tentatively stored as the target.
-
- 3. All prerequisites of this target are examined using this same
- method.
-
- 4. After processing the prerequisites, the target may or may not need
- to be rebuilt:
-
- a. If the target does _not_ need to be rebuilt, the path to the
- file found during directory search is used for any
- prerequisite lists which contain this target. In short, if
- `make' doesn't need to rebuild the target then you use the
- path found via directory search.
-
- b. If the target _does_ need to be rebuilt (is out-of-date), the
- pathname found during directory search is _thrown away_, and
- the target is rebuilt using the file name specified in the
- makefile. In short, if `make' must rebuild, then the target
- is rebuilt locally, not in the directory found via directory
- search.
-
- This algorithm may seem complex, but in practice it is quite often
-exactly what you want.
-
- Other versions of `make' use a simpler algorithm: if the file does
-not exist, and it is found via directory search, then that pathname is
-always used whether or not the target needs to be built. Thus, if the
-target is rebuilt it is created at the pathname discovered during
-directory search.
-
- If, in fact, this is the behavior you want for some or all of your
-directories, you can use the `GPATH' variable to indicate this to
-`make'.
-
- `GPATH' has the same syntax and format as `VPATH' (that is, a space-
-or colon-delimited list of pathnames). If an out-of-date target is
-found by directory search in a directory that also appears in `GPATH',
-then that pathname is not thrown away. The target is rebuilt using the
-expanded path.
-
-
-File: make.info, Node: Commands/Search, Next: Implicit/Search, Prev: Search Algorithm, Up: Directory Search
-
-4.5.4 Writing Shell Commands with Directory Search
---------------------------------------------------
-
-When a prerequisite is found in another directory through directory
-search, this cannot change the commands of the rule; they will execute
-as written. Therefore, you must write the commands with care so that
-they will look for the prerequisite in the directory where `make' finds
-it.
-
- This is done with the "automatic variables" such as `$^' (*note
-Automatic Variables::). For instance, the value of `$^' is a list of
-all the prerequisites of the rule, including the names of the
-directories in which they were found, and the value of `$@' is the
-target. Thus:
-
- foo.o : foo.c
- cc -c $(CFLAGS) $^ -o $@
-
-(The variable `CFLAGS' exists so you can specify flags for C
-compilation by implicit rules; we use it here for consistency so it will
-affect all C compilations uniformly; *note Variables Used by Implicit
-Rules: Implicit Variables.)
-
- Often the prerequisites include header files as well, which you do
-not want to mention in the commands. The automatic variable `$<' is
-just the first prerequisite:
-
- VPATH = src:../headers
- foo.o : foo.c defs.h hack.h
- cc -c $(CFLAGS) $< -o $@
-
-
-File: make.info, Node: Implicit/Search, Next: Libraries/Search, Prev: Commands/Search, Up: Directory Search
-
-4.5.5 Directory Search and Implicit Rules
------------------------------------------
-
-The search through the directories specified in `VPATH' or with `vpath'
-also happens during consideration of implicit rules (*note Using
-Implicit Rules: Implicit Rules.).
-
- For example, when a file `foo.o' has no explicit rule, `make'
-considers implicit rules, such as the built-in rule to compile `foo.c'
-if that file exists. If such a file is lacking in the current
-directory, the appropriate directories are searched for it. If `foo.c'
-exists (or is mentioned in the makefile) in any of the directories, the
-implicit rule for C compilation is applied.
-
- The commands of implicit rules normally use automatic variables as a
-matter of necessity; consequently they will use the file names found by
-directory search with no extra effort.
-
-
-File: make.info, Node: Libraries/Search, Prev: Implicit/Search, Up: Directory Search
-
-4.5.6 Directory Search for Link Libraries
------------------------------------------
-
-Directory search applies in a special way to libraries used with the
-linker. This special feature comes into play when you write a
-prerequisite whose name is of the form `-lNAME'. (You can tell
-something strange is going on here because the prerequisite is normally
-the name of a file, and the _file name_ of a library generally looks
-like `libNAME.a', not like `-lNAME'.)
-
- When a prerequisite's name has the form `-lNAME', `make' handles it
-specially by searching for the file `libNAME.so' in the current
-directory, in directories specified by matching `vpath' search paths
-and the `VPATH' search path, and then in the directories `/lib',
-`/usr/lib', and `PREFIX/lib' (normally `/usr/local/lib', but
-MS-DOS/MS-Windows versions of `make' behave as if PREFIX is defined to
-be the root of the DJGPP installation tree).
-
- If that file is not found, then the file `libNAME.a' is searched
-for, in the same directories as above.
-
- For example, if there is a `/usr/lib/libcurses.a' library on your
-system (and no `/usr/lib/libcurses.so' file), then
-
- foo : foo.c -lcurses
- cc $^ -o $@
-
-would cause the command `cc foo.c /usr/lib/libcurses.a -o foo' to be
-executed when `foo' is older than `foo.c' or than
-`/usr/lib/libcurses.a'.
-
- Although the default set of files to be searched for is `libNAME.so'
-and `libNAME.a', this is customizable via the `.LIBPATTERNS' variable.
-Each word in the value of this variable is a pattern string. When a
-prerequisite like `-lNAME' is seen, `make' will replace the percent in
-each pattern in the list with NAME and perform the above directory
-searches using that library filename. If no library is found, the next
-word in the list will be used.
-
- The default value for `.LIBPATTERNS' is `lib%.so lib%.a', which
-provides the default behavior described above.
-
- You can turn off link library expansion completely by setting this
-variable to an empty value.
-
-
-File: make.info, Node: Phony Targets, Next: Force Targets, Prev: Directory Search, Up: Rules
-
-4.6 Phony Targets
-=================
-
-A phony target is one that is not really the name of a file. It is
-just a name for some commands to be executed when you make an explicit
-request. There are two reasons to use a phony target: to avoid a
-conflict with a file of the same name, and to improve performance.
-
- If you write a rule whose commands will not create the target file,
-the commands will be executed every time the target comes up for
-remaking. Here is an example:
-
- clean:
- rm *.o temp
-
-Because the `rm' command does not create a file named `clean', probably
-no such file will ever exist. Therefore, the `rm' command will be
-executed every time you say `make clean'.
-
- The phony target will cease to work if anything ever does create a
-file named `clean' in this directory. Since it has no prerequisites,
-the file `clean' would inevitably be considered up to date, and its
-commands would not be executed. To avoid this problem, you can
-explicitly declare the target to be phony, using the special target
-`.PHONY' (*note Special Built-in Target Names: Special Targets.) as
-follows:
-
- .PHONY : clean
-
-Once this is done, `make clean' will run the commands regardless of
-whether there is a file named `clean'.
-
- Since it knows that phony targets do not name actual files that
-could be remade from other files, `make' skips the implicit rule search
-for phony targets (*note Implicit Rules::). This is why declaring a
-target phony is good for performance, even if you are not worried about
-the actual file existing.
-
- Thus, you first write the line that states that `clean' is a phony
-target, then you write the rule, like this:
-
- .PHONY: clean
- clean:
- rm *.o temp
-
- Another example of the usefulness of phony targets is in conjunction
-with recursive invocations of `make' (for more information, see *Note
-Recursive Use of `make': Recursion.). In this case the makefile will
-often contain a variable which lists a number of subdirectories to be
-built. One way to handle this is with one rule whose command is a
-shell loop over the subdirectories, like this:
-
- SUBDIRS = foo bar baz
-
- subdirs:
- for dir in $(SUBDIRS); do \
- $(MAKE) -C $$dir; \
- done
-
- There are a few problems with this method, however. First, any error
-detected in a submake is not noted by this rule, so it will continue to
-build the rest of the directories even when one fails. This can be
-overcome by adding shell commands to note the error and exit, but then
-it will do so even if `make' is invoked with the `-k' option, which is
-unfortunate. Second, and perhaps more importantly, you cannot take
-advantage of `make''s ability to build targets in parallel (*note
-Parallel Execution: Parallel.), since there is only one rule.
-
- By declaring the subdirectories as phony targets (you must do this as
-the subdirectory obviously always exists; otherwise it won't be built)
-you can remove these problems:
-
- SUBDIRS = foo bar baz
-
- .PHONY: subdirs $(SUBDIRS)
-
- subdirs: $(SUBDIRS)
-
- $(SUBDIRS):
- $(MAKE) -C $@
-
- foo: baz
-
- Here we've also declared that the `foo' subdirectory cannot be built
-until after the `baz' subdirectory is complete; this kind of
-relationship declaration is particularly important when attempting
-parallel builds.
-
- A phony target should not be a prerequisite of a real target file;
-if it is, its commands are run every time `make' goes to update that
-file. As long as a phony target is never a prerequisite of a real
-target, the phony target commands will be executed only when the phony
-target is a specified goal (*note Arguments to Specify the Goals:
-Goals.).
-
- Phony targets can have prerequisites. When one directory contains
-multiple programs, it is most convenient to describe all of the
-programs in one makefile `./Makefile'. Since the target remade by
-default will be the first one in the makefile, it is common to make
-this a phony target named `all' and give it, as prerequisites, all the
-individual programs. For example:
-
- all : prog1 prog2 prog3
- .PHONY : all
-
- prog1 : prog1.o utils.o
- cc -o prog1 prog1.o utils.o
-
- prog2 : prog2.o
- cc -o prog2 prog2.o
-
- prog3 : prog3.o sort.o utils.o
- cc -o prog3 prog3.o sort.o utils.o
-
-Now you can say just `make' to remake all three programs, or specify as
-arguments the ones to remake (as in `make prog1 prog3'). Phoniness is
-not inherited: the prerequisites of a phony target are not themselves
-phony, unless explicitly declared to be so.
-
- When one phony target is a prerequisite of another, it serves as a
-subroutine of the other. For example, here `make cleanall' will delete
-the object files, the difference files, and the file `program':
-
- .PHONY: cleanall cleanobj cleandiff
-
- cleanall : cleanobj cleandiff
- rm program
-
- cleanobj :
- rm *.o
-
- cleandiff :
- rm *.diff
-
-
-File: make.info, Node: Force Targets, Next: Empty Targets, Prev: Phony Targets, Up: Rules
-
-4.7 Rules without Commands or Prerequisites
-===========================================
-
-If a rule has no prerequisites or commands, and the target of the rule
-is a nonexistent file, then `make' imagines this target to have been
-updated whenever its rule is run. This implies that all targets
-depending on this one will always have their commands run.
-
- An example will illustrate this:
-
- clean: FORCE
- rm $(objects)
- FORCE:
-
- Here the target `FORCE' satisfies the special conditions, so the
-target `clean' that depends on it is forced to run its commands. There
-is nothing special about the name `FORCE', but that is one name
-commonly used this way.
-
- As you can see, using `FORCE' this way has the same results as using
-`.PHONY: clean'.
-
- Using `.PHONY' is more explicit and more efficient. However, other
-versions of `make' do not support `.PHONY'; thus `FORCE' appears in
-many makefiles. *Note Phony Targets::.
-
-
-File: make.info, Node: Empty Targets, Next: Special Targets, Prev: Force Targets, Up: Rules
-
-4.8 Empty Target Files to Record Events
-=======================================
-
-The "empty target" is a variant of the phony target; it is used to hold
-commands for an action that you request explicitly from time to time.
-Unlike a phony target, this target file can really exist; but the file's
-contents do not matter, and usually are empty.
-
- The purpose of the empty target file is to record, with its
-last-modification time, when the rule's commands were last executed. It
-does so because one of the commands is a `touch' command to update the
-target file.
-
- The empty target file should have some prerequisites (otherwise it
-doesn't make sense). When you ask to remake the empty target, the
-commands are executed if any prerequisite is more recent than the
-target; in other words, if a prerequisite has changed since the last
-time you remade the target. Here is an example:
-
- print: foo.c bar.c
- lpr -p $?
- touch print
-
-With this rule, `make print' will execute the `lpr' command if either
-source file has changed since the last `make print'. The automatic
-variable `$?' is used to print only those files that have changed
-(*note Automatic Variables::).
-
-
-File: make.info, Node: Special Targets, Next: Multiple Targets, Prev: Empty Targets, Up: Rules
-
-4.9 Special Built-in Target Names
-=================================
-
-Certain names have special meanings if they appear as targets.
-
-`.PHONY'
- The prerequisites of the special target `.PHONY' are considered to
- be phony targets. When it is time to consider such a target,
- `make' will run its commands unconditionally, regardless of
- whether a file with that name exists or what its last-modification
- time is. *Note Phony Targets: Phony Targets.
-
-`.SUFFIXES'
- The prerequisites of the special target `.SUFFIXES' are the list
- of suffixes to be used in checking for suffix rules. *Note
- Old-Fashioned Suffix Rules: Suffix Rules.
-
-`.DEFAULT'
- The commands specified for `.DEFAULT' are used for any target for
- which no rules are found (either explicit rules or implicit rules).
- *Note Last Resort::. If `.DEFAULT' commands are specified, every
- file mentioned as a prerequisite, but not as a target in a rule,
- will have these commands executed on its behalf. *Note Implicit
- Rule Search Algorithm: Implicit Rule Search.
-
-`.PRECIOUS'
- The targets which `.PRECIOUS' depends on are given the following
- special treatment: if `make' is killed or interrupted during the
- execution of their commands, the target is not deleted. *Note
- Interrupting or Killing `make': Interrupts. Also, if the target
- is an intermediate file, it will not be deleted after it is no
- longer needed, as is normally done. *Note Chains of Implicit
- Rules: Chained Rules. In this latter respect it overlaps with the
- `.SECONDARY' special target.
-
- You can also list the target pattern of an implicit rule (such as
- `%.o') as a prerequisite file of the special target `.PRECIOUS' to
- preserve intermediate files created by rules whose target patterns
- match that file's name.
-
-`.INTERMEDIATE'
- The targets which `.INTERMEDIATE' depends on are treated as
- intermediate files. *Note Chains of Implicit Rules: Chained Rules.
- `.INTERMEDIATE' with no prerequisites has no effect.
-
-`.SECONDARY'
- The targets which `.SECONDARY' depends on are treated as
- intermediate files, except that they are never automatically
- deleted. *Note Chains of Implicit Rules: Chained Rules.
-
- `.SECONDARY' with no prerequisites causes all targets to be treated
- as secondary (i.e., no target is removed because it is considered
- intermediate).
-
-`.SECONDEXPANSION'
- If `.SECONDEXPANSION' is mentioned as a target anywhere in the
- makefile, then all prerequisite lists defined _after_ it appears
- will be expanded a second time after all makefiles have been read
- in. *Note Secondary Expansion: Secondary Expansion.
-
- The prerequisites of the special target `.SUFFIXES' are the list
- of suffixes to be used in checking for suffix rules. *Note
- Old-Fashioned Suffix Rules: Suffix Rules.
-
-`.DELETE_ON_ERROR'
- If `.DELETE_ON_ERROR' is mentioned as a target anywhere in the
- makefile, then `make' will delete the target of a rule if it has
- changed and its commands exit with a nonzero exit status, just as
- it does when it receives a signal. *Note Errors in Commands:
- Errors.
-
-`.IGNORE'
- If you specify prerequisites for `.IGNORE', then `make' will
- ignore errors in execution of the commands run for those particular
- files. The commands for `.IGNORE' are not meaningful.
-
- If mentioned as a target with no prerequisites, `.IGNORE' says to
- ignore errors in execution of commands for all files. This usage
- of `.IGNORE' is supported only for historical compatibility. Since
- this affects every command in the makefile, it is not very useful;
- we recommend you use the more selective ways to ignore errors in
- specific commands. *Note Errors in Commands: Errors.
-
-`.LOW_RESOLUTION_TIME'
- If you specify prerequisites for `.LOW_RESOLUTION_TIME', `make'
- assumes that these files are created by commands that generate low
- resolution time stamps. The commands for `.LOW_RESOLUTION_TIME'
- are not meaningful.
-
- The high resolution file time stamps of many modern hosts lessen
- the chance of `make' incorrectly concluding that a file is up to
- date. Unfortunately, these hosts provide no way to set a high
- resolution file time stamp, so commands like `cp -p' that
- explicitly set a file's time stamp must discard its subsecond
- part. If a file is created by such a command, you should list it
- as a prerequisite of `.LOW_RESOLUTION_TIME' so that `make' does
- not mistakenly conclude that the file is out of date. For example:
-
- .LOW_RESOLUTION_TIME: dst
- dst: src
- cp -p src dst
-
- Since `cp -p' discards the subsecond part of `src''s time stamp,
- `dst' is typically slightly older than `src' even when it is up to
- date. The `.LOW_RESOLUTION_TIME' line causes `make' to consider
- `dst' to be up to date if its time stamp is at the start of the
- same second that `src''s time stamp is in.
-
- Due to a limitation of the archive format, archive member time
- stamps are always low resolution. You need not list archive
- members as prerequisites of `.LOW_RESOLUTION_TIME', as `make' does
- this automatically.
-
-`.SILENT'
- If you specify prerequisites for `.SILENT', then `make' will not
- print the commands to remake those particular files before
- executing them. The commands for `.SILENT' are not meaningful.
-
- If mentioned as a target with no prerequisites, `.SILENT' says not
- to print any commands before executing them. This usage of
- `.SILENT' is supported only for historical compatibility. We
- recommend you use the more selective ways to silence specific
- commands. *Note Command Echoing: Echoing. If you want to silence
- all commands for a particular run of `make', use the `-s' or
- `--silent' option (*note Options Summary::).
-
-`.EXPORT_ALL_VARIABLES'
- Simply by being mentioned as a target, this tells `make' to export
- all variables to child processes by default. *Note Communicating
- Variables to a Sub-`make': Variables/Recursion.
-
-`.NOTPARALLEL'
- If `.NOTPARALLEL' is mentioned as a target, then this invocation of
- `make' will be run serially, even if the `-j' option is given.
- Any recursively invoked `make' command will still be run in
- parallel (unless its makefile contains this target). Any
- prerequisites on this target are ignored.
-
- Any defined implicit rule suffix also counts as a special target if
-it appears as a target, and so does the concatenation of two suffixes,
-such as `.c.o'. These targets are suffix rules, an obsolete way of
-defining implicit rules (but a way still widely used). In principle,
-any target name could be special in this way if you break it in two and
-add both pieces to the suffix list. In practice, suffixes normally
-begin with `.', so these special target names also begin with `.'.
-*Note Old-Fashioned Suffix Rules: Suffix Rules.
-
-
-File: make.info, Node: Multiple Targets, Next: Multiple Rules, Prev: Special Targets, Up: Rules
-
-4.10 Multiple Targets in a Rule
-===============================
-
-A rule with multiple targets is equivalent to writing many rules, each
-with one target, and all identical aside from that. The same commands
-apply to all the targets, but their effects may vary because you can
-substitute the actual target name into the command using `$@'. The
-rule contributes the same prerequisites to all the targets also.
-
- This is useful in two cases.
-
- * You want just prerequisites, no commands. For example:
-
- kbd.o command.o files.o: command.h
-
- gives an additional prerequisite to each of the three object files
- mentioned.
-
- * Similar commands work for all the targets. The commands do not
- need to be absolutely identical, since the automatic variable `$@'
- can be used to substitute the particular target to be remade into
- the commands (*note Automatic Variables::). For example:
-
- bigoutput littleoutput : text.g
- generate text.g -$(subst output,,$@) > $@
-
- is equivalent to
-
- bigoutput : text.g
- generate text.g -big > bigoutput
- littleoutput : text.g
- generate text.g -little > littleoutput
-
- Here we assume the hypothetical program `generate' makes two types
- of output, one if given `-big' and one if given `-little'. *Note
- Functions for String Substitution and Analysis: Text Functions,
- for an explanation of the `subst' function.
-
- Suppose you would like to vary the prerequisites according to the
-target, much as the variable `$@' allows you to vary the commands. You
-cannot do this with multiple targets in an ordinary rule, but you can
-do it with a "static pattern rule". *Note Static Pattern Rules: Static
-Pattern.
-
-
-File: make.info, Node: Multiple Rules, Next: Static Pattern, Prev: Multiple Targets, Up: Rules
-
-4.11 Multiple Rules for One Target
-==================================
-
-One file can be the target of several rules. All the prerequisites
-mentioned in all the rules are merged into one list of prerequisites for
-the target. If the target is older than any prerequisite from any rule,
-the commands are executed.
-
- There can only be one set of commands to be executed for a file. If
-more than one rule gives commands for the same file, `make' uses the
-last set given and prints an error message. (As a special case, if the
-file's name begins with a dot, no error message is printed. This odd
-behavior is only for compatibility with other implementations of
-`make'... you should avoid using it). Occasionally it is useful to
-have the same target invoke multiple commands which are defined in
-different parts of your makefile; you can use "double-colon rules"
-(*note Double-Colon::) for this.
-
- An extra rule with just prerequisites can be used to give a few extra
-prerequisites to many files at once. For example, makefiles often have
-a variable, such as `objects', containing a list of all the compiler
-output files in the system being made. An easy way to say that all of
-them must be recompiled if `config.h' changes is to write the following:
-
- objects = foo.o bar.o
- foo.o : defs.h
- bar.o : defs.h test.h
- $(objects) : config.h
-
- This could be inserted or taken out without changing the rules that
-really specify how to make the object files, making it a convenient
-form to use if you wish to add the additional prerequisite
-intermittently.
-
- Another wrinkle is that the additional prerequisites could be
-specified with a variable that you set with a command argument to `make'
-(*note Overriding Variables: Overriding.). For example,
-
- extradeps=
- $(objects) : $(extradeps)
-
-means that the command `make extradeps=foo.h' will consider `foo.h' as
-a prerequisite of each object file, but plain `make' will not.
-
- If none of the explicit rules for a target has commands, then `make'
-searches for an applicable implicit rule to find some commands *note
-Using Implicit Rules: Implicit Rules.).
-
-
-File: make.info, Node: Static Pattern, Next: Double-Colon, Prev: Multiple Rules, Up: Rules
-
-4.12 Static Pattern Rules
-=========================
-
-"Static pattern rules" are rules which specify multiple targets and
-construct the prerequisite names for each target based on the target
-name. They are more general than ordinary rules with multiple targets
-because the targets do not have to have identical prerequisites. Their
-prerequisites must be _analogous_, but not necessarily _identical_.
-
-* Menu:
-
-* Static Usage:: The syntax of static pattern rules.
-* Static versus Implicit:: When are they better than implicit rules?
-
-
-File: make.info, Node: Static Usage, Next: Static versus Implicit, Prev: Static Pattern, Up: Static Pattern
-
-4.12.1 Syntax of Static Pattern Rules
--------------------------------------
-
-Here is the syntax of a static pattern rule:
-
- TARGETS ...: TARGET-PATTERN: PREREQ-PATTERNS ...
- COMMANDS
- ...
-
-The TARGETS list specifies the targets that the rule applies to. The
-targets can contain wildcard characters, just like the targets of
-ordinary rules (*note Using Wildcard Characters in File Names:
-Wildcards.).
-
- The TARGET-PATTERN and PREREQ-PATTERNS say how to compute the
-prerequisites of each target. Each target is matched against the
-TARGET-PATTERN to extract a part of the target name, called the "stem".
-This stem is substituted into each of the PREREQ-PATTERNS to make the
-prerequisite names (one from each PREREQ-PATTERN).
-
- Each pattern normally contains the character `%' just once. When the
-TARGET-PATTERN matches a target, the `%' can match any part of the
-target name; this part is called the "stem". The rest of the pattern
-must match exactly. For example, the target `foo.o' matches the
-pattern `%.o', with `foo' as the stem. The targets `foo.c' and
-`foo.out' do not match that pattern.
-
- The prerequisite names for each target are made by substituting the
-stem for the `%' in each prerequisite pattern. For example, if one
-prerequisite pattern is `%.c', then substitution of the stem `foo'
-gives the prerequisite name `foo.c'. It is legitimate to write a
-prerequisite pattern that does not contain `%'; then this prerequisite
-is the same for all targets.
-
- `%' characters in pattern rules can be quoted with preceding
-backslashes (`\'). Backslashes that would otherwise quote `%'
-characters can be quoted with more backslashes. Backslashes that quote
-`%' characters or other backslashes are removed from the pattern before
-it is compared to file names or has a stem substituted into it.
-Backslashes that are not in danger of quoting `%' characters go
-unmolested. For example, the pattern `the\%weird\\%pattern\\' has
-`the%weird\' preceding the operative `%' character, and `pattern\\'
-following it. The final two backslashes are left alone because they
-cannot affect any `%' character.
-
- Here is an example, which compiles each of `foo.o' and `bar.o' from
-the corresponding `.c' file:
-
- objects = foo.o bar.o
-
- all: $(objects)
-
- $(objects): %.o: %.c
- $(CC) -c $(CFLAGS) $< -o $@
-
-Here `$<' is the automatic variable that holds the name of the
-prerequisite and `$@' is the automatic variable that holds the name of
-the target; see *Note Automatic Variables::.
-
- Each target specified must match the target pattern; a warning is
-issued for each target that does not. If you have a list of files,
-only some of which will match the pattern, you can use the `filter'
-function to remove nonmatching file names (*note Functions for String
-Substitution and Analysis: Text Functions.):
-
- files = foo.elc bar.o lose.o
-
- $(filter %.o,$(files)): %.o: %.c
- $(CC) -c $(CFLAGS) $< -o $@
- $(filter %.elc,$(files)): %.elc: %.el
- emacs -f batch-byte-compile $<
-
-In this example the result of `$(filter %.o,$(files))' is `bar.o
-lose.o', and the first static pattern rule causes each of these object
-files to be updated by compiling the corresponding C source file. The
-result of `$(filter %.elc,$(files))' is `foo.elc', so that file is made
-from `foo.el'.
-
- Another example shows how to use `$*' in static pattern rules:
-
- bigoutput littleoutput : %output : text.g
- generate text.g -$* > $@
-
-When the `generate' command is run, `$*' will expand to the stem,
-either `big' or `little'.
-
-
-File: make.info, Node: Static versus Implicit, Prev: Static Usage, Up: Static Pattern
-
-4.12.2 Static Pattern Rules versus Implicit Rules
--------------------------------------------------
-
-A static pattern rule has much in common with an implicit rule defined
-as a pattern rule (*note Defining and Redefining Pattern Rules: Pattern
-Rules.). Both have a pattern for the target and patterns for
-constructing the names of prerequisites. The difference is in how
-`make' decides _when_ the rule applies.
-
- An implicit rule _can_ apply to any target that matches its pattern,
-but it _does_ apply only when the target has no commands otherwise
-specified, and only when the prerequisites can be found. If more than
-one implicit rule appears applicable, only one applies; the choice
-depends on the order of rules.
-
- By contrast, a static pattern rule applies to the precise list of
-targets that you specify in the rule. It cannot apply to any other
-target and it invariably does apply to each of the targets specified.
-If two conflicting rules apply, and both have commands, that's an error.
-
- The static pattern rule can be better than an implicit rule for these
-reasons:
-
- * You may wish to override the usual implicit rule for a few files
- whose names cannot be categorized syntactically but can be given
- in an explicit list.
-
- * If you cannot be sure of the precise contents of the directories
- you are using, you may not be sure which other irrelevant files
- might lead `make' to use the wrong implicit rule. The choice
- might depend on the order in which the implicit rule search is
- done. With static pattern rules, there is no uncertainty: each
- rule applies to precisely the targets specified.
-
-
-File: make.info, Node: Double-Colon, Next: Automatic Prerequisites, Prev: Static Pattern, Up: Rules
-
-4.13 Double-Colon Rules
-=======================
-
-"Double-colon" rules are rules written with `::' instead of `:' after
-the target names. They are handled differently from ordinary rules
-when the same target appears in more than one rule.
-
- When a target appears in multiple rules, all the rules must be the
-same type: all ordinary, or all double-colon. If they are
-double-colon, each of them is independent of the others. Each
-double-colon rule's commands are executed if the target is older than
-any prerequisites of that rule. If there are no prerequisites for that
-rule, its commands are always executed (even if the target already
-exists). This can result in executing none, any, or all of the
-double-colon rules.
-
- Double-colon rules with the same target are in fact completely
-separate from one another. Each double-colon rule is processed
-individually, just as rules with different targets are processed.
-
- The double-colon rules for a target are executed in the order they
-appear in the makefile. However, the cases where double-colon rules
-really make sense are those where the order of executing the commands
-would not matter.
-
- Double-colon rules are somewhat obscure and not often very useful;
-they provide a mechanism for cases in which the method used to update a
-target differs depending on which prerequisite files caused the update,
-and such cases are rare.
-
- Each double-colon rule should specify commands; if it does not, an
-implicit rule will be used if one applies. *Note Using Implicit Rules:
-Implicit Rules.
-
-
-File: make.info, Node: Automatic Prerequisites, Prev: Double-Colon, Up: Rules
-
-4.14 Generating Prerequisites Automatically
-===========================================
-
-In the makefile for a program, many of the rules you need to write often
-say only that some object file depends on some header file. For
-example, if `main.c' uses `defs.h' via an `#include', you would write:
-
- main.o: defs.h
-
-You need this rule so that `make' knows that it must remake `main.o'
-whenever `defs.h' changes. You can see that for a large program you
-would have to write dozens of such rules in your makefile. And, you
-must always be very careful to update the makefile every time you add
-or remove an `#include'.
-
- To avoid this hassle, most modern C compilers can write these rules
-for you, by looking at the `#include' lines in the source files.
-Usually this is done with the `-M' option to the compiler. For
-example, the command:
-
- cc -M main.c
-
-generates the output:
-
- main.o : main.c defs.h
-
-Thus you no longer have to write all those rules yourself. The
-compiler will do it for you.
-
- Note that such a prerequisite constitutes mentioning `main.o' in a
-makefile, so it can never be considered an intermediate file by implicit
-rule search. This means that `make' won't ever remove the file after
-using it; *note Chains of Implicit Rules: Chained Rules.
-
- With old `make' programs, it was traditional practice to use this
-compiler feature to generate prerequisites on demand with a command like
-`make depend'. That command would create a file `depend' containing
-all the automatically-generated prerequisites; then the makefile could
-use `include' to read them in (*note Include::).
-
- In GNU `make', the feature of remaking makefiles makes this practice
-obsolete--you need never tell `make' explicitly to regenerate the
-prerequisites, because it always regenerates any makefile that is out
-of date. *Note Remaking Makefiles::.
-
- The practice we recommend for automatic prerequisite generation is
-to have one makefile corresponding to each source file. For each
-source file `NAME.c' there is a makefile `NAME.d' which lists what
-files the object file `NAME.o' depends on. That way only the source
-files that have changed need to be rescanned to produce the new
-prerequisites.
-
- Here is the pattern rule to generate a file of prerequisites (i.e.,
-a makefile) called `NAME.d' from a C source file called `NAME.c':
-
- %.d: %.c
- @set -e; rm -f $@; \
- $(CC) -M $(CPPFLAGS) $< > $@.$$$$; \
- sed 's,\($*\)\.o[ :]*,\1.o $@ : ,g' < $@.$$$$ > $@; \
- rm -f $@.$$$$
-
-*Note Pattern Rules::, for information on defining pattern rules. The
-`-e' flag to the shell causes it to exit immediately if the `$(CC)'
-command (or any other command) fails (exits with a nonzero status).
-
- With the GNU C compiler, you may wish to use the `-MM' flag instead
-of `-M'. This omits prerequisites on system header files. *Note
-Options Controlling the Preprocessor: (gcc.info)Preprocessor Options,
-for details.
-
- The purpose of the `sed' command is to translate (for example):
-
- main.o : main.c defs.h
-
-into:
-
- main.o main.d : main.c defs.h
-
-This makes each `.d' file depend on all the source and header files
-that the corresponding `.o' file depends on. `make' then knows it must
-regenerate the prerequisites whenever any of the source or header files
-changes.
-
- Once you've defined the rule to remake the `.d' files, you then use
-the `include' directive to read them all in. *Note Include::. For
-example:
-
- sources = foo.c bar.c
-
- include $(sources:.c=.d)
-
-(This example uses a substitution variable reference to translate the
-list of source files `foo.c bar.c' into a list of prerequisite
-makefiles, `foo.d bar.d'. *Note Substitution Refs::, for full
-information on substitution references.) Since the `.d' files are
-makefiles like any others, `make' will remake them as necessary with no
-further work from you. *Note Remaking Makefiles::.
-
- Note that the `.d' files contain target definitions; you should be
-sure to place the `include' directive _after_ the first, default goal
-in your makefiles or run the risk of having a random object file become
-the default goal. *Note How Make Works::.
-
-
-File: make.info, Node: Commands, Next: Using Variables, Prev: Rules, Up: Top
-
-5 Writing the Commands in Rules
-*******************************
-
-The commands of a rule consist of one or more shell command lines to be
-executed, one at a time, in the order they appear. Typically, the
-result of executing these commands is that the target of the rule is
-brought up to date.
-
- Users use many different shell programs, but commands in makefiles
-are always interpreted by `/bin/sh' unless the makefile specifies
-otherwise. *Note Command Execution: Execution.
-
-* Menu:
-
-* Command Syntax:: Command syntax features and pitfalls.
-* Echoing:: How to control when commands are echoed.
-* Execution:: How commands are executed.
-* Parallel:: How commands can be executed in parallel.
-* Errors:: What happens after a command execution error.
-* Interrupts:: What happens when a command is interrupted.
-* Recursion:: Invoking `make' from makefiles.
-* Sequences:: Defining canned sequences of commands.
-* Empty Commands:: Defining useful, do-nothing commands.
-
-
-File: make.info, Node: Command Syntax, Next: Echoing, Prev: Commands, Up: Commands
-
-5.1 Command Syntax
-==================
-
-Makefiles have the unusual property that there are really two distinct
-syntaxes in one file. Most of the makefile uses `make' syntax (*note
-Writing Makefiles: Makefiles.). However, commands are meant to be
-interpreted by the shell and so they are written using shell syntax.
-The `make' program does not try to understand shell syntax: it performs
-only a very few specific translations on the content of the command
-before handing it to the shell.
-
- Each command line must start with a tab, except that the first
-command line may be attached to the target-and-prerequisites line with a
-semicolon in between. _Any_ line in the makefile that begins with a
-tab and appears in a "rule context" (that is, after a rule has been
-started until another rule or variable definition) will be considered a
-command line for that rule. Blank lines and lines of just comments may
-appear among the command lines; they are ignored.
-
- Some consequences of these rules include:
-
- * A blank line that begins with a tab is not blank: it's an empty
- command (*note Empty Commands::).
-
- * A comment in a command line is not a `make' comment; it will be
- passed to the shell as-is. Whether the shell treats it as a
- comment or not depends on your shell.
-
- * A variable definition in a "rule context" which is indented by a
- tab as the first character on the line, will be considered a
- command line, not a `make' variable definition, and passed to the
- shell.
-
- * A conditional expression (`ifdef', `ifeq', etc. *note Syntax of
- Conditionals: Conditional Syntax.) in a "rule context" which is
- indented by a tab as the first character on the line, will be
- considered a command line and be passed to the shell.
-
-
-* Menu:
-
-* Splitting Lines:: Breaking long command lines for readability.
-* Variables in Commands:: Using `make' variables in commands.
-
-
-File: make.info, Node: Splitting Lines, Next: Variables in Commands, Prev: Command Syntax, Up: Command Syntax
-
-5.1.1 Splitting Command Lines
------------------------------
-
-One of the few ways in which `make' does interpret command lines is
-checking for a backslash just before the newline. As in normal
-makefile syntax, a single command can be split into multiple lines in
-the makefile by placing a backslash before each newline. A sequence of
-lines like this is considered a single command, and one instance of the
-shell will be invoked to run it.
-
- However, in contrast to how they are treated in other places in a
-makefile, backslash-newline pairs are _not_ removed from the command.
-Both the backslash and the newline characters are preserved and passed
-to the shell. How the backslash-newline is interpreted depends on your
-shell. If the first character of the next line after the
-backslash-newline is a tab, then that tab (and only that tab) is
-removed. Whitespace is never added to the command.
-
- For example, this makefile:
-
- all :
- @echo no\
- space
- @echo no\
- space
- @echo one \
- space
- @echo one\
- space
-
-consists of four separate shell commands where the output is:
-
- nospace
- nospace
- one space
- one space
-
- As a more complex example, this makefile:
-
- all : ; @echo 'hello \
- world' ; echo "hello \
- world"
-
-will run one shell with a command script of:
-
- echo 'hello \
- world' ; echo "hello \
- world"
-
-which, according to shell quoting rules, will yield the following
-output:
-
- hello \
- world
- hello world
-
-Notice how the backslash/newline pair was removed inside the string
-quoted with double quotes (`"..."'), but not from the string quoted
-with single quotes (`'...''). This is the way the default shell
-(`/bin/sh') handles backslash/newline pairs. If you specify a
-different shell in your makefiles it may treat them differently.
-
- Sometimes you want to split a long line inside of single quotes, but
-you don't want the backslash-newline to appear in the quoted content.
-This is often the case when passing scripts to languages such as Perl,
-where extraneous backslashes inside the script can change its meaning
-or even be a syntax error. One simple way of handling this is to place
-the quoted string, or even the entire command, into a `make' variable
-then use the variable in the command. In this situation the newline
-quoting rules for makefiles will be used, and the backslash-newline
-will be removed. If we rewrite our example above using this method:
-
- HELLO = 'hello \
- world'
-
- all : ; @echo $(HELLO)
-
-we will get output like this:
-
- hello world
-
- If you like, you can also use target-specific variables (*note
-Target-specific Variable Values: Target-specific.) to obtain a tighter
-correspondence between the variable and the command that uses it.
-
-
-File: make.info, Node: Variables in Commands, Prev: Splitting Lines, Up: Command Syntax
-
-5.1.2 Using Variables in Commands
----------------------------------
-
-The other way in which `make' processes commands is by expanding any
-variable references in them (*note Basics of Variable References:
-Reference.). This occurs after make has finished reading all the
-makefiles and the target is determined to be out of date; so, the
-commands for targets which are not rebuilt are never expanded.
-
- Variable and function references in commands have identical syntax
-and semantics to references elsewhere in the makefile. They also have
-the same quoting rules: if you want a dollar sign to appear in your
-command, you must double it (`$$'). For shells like the default shell,
-that use dollar signs to introduce variables, it's important to keep
-clear in your mind whether the variable you want to reference is a
-`make' variable (use a single dollar sign) or a shell variable (use two
-dollar signs). For example:
-
- LIST = one two three
- all:
- for i in $(LIST); do \
- echo $$i; \
- done
-
-results in the following command being passed to the shell:
-
- for i in one two three; do \
- echo $i; \
- done
-
-which generates the expected result:
-
- one
- two
- three
-
-
-File: make.info, Node: Echoing, Next: Execution, Prev: Command Syntax, Up: Commands
-
-5.2 Command Echoing
-===================
-
-Normally `make' prints each command line before it is executed. We
-call this "echoing" because it gives the appearance that you are typing
-the commands yourself.
-
- When a line starts with `@', the echoing of that line is suppressed.
-The `@' is discarded before the command is passed to the shell.
-Typically you would use this for a command whose only effect is to print
-something, such as an `echo' command to indicate progress through the
-makefile:
-
- @echo About to make distribution files
-
- When `make' is given the flag `-n' or `--just-print' it only echoes
-commands, it won't execute them. *Note Summary of Options: Options
-Summary. In this case and only this case, even the commands starting
-with `@' are printed. This flag is useful for finding out which
-commands `make' thinks are necessary without actually doing them.
-
- The `-s' or `--silent' flag to `make' prevents all echoing, as if
-all commands started with `@'. A rule in the makefile for the special
-target `.SILENT' without prerequisites has the same effect (*note
-Special Built-in Target Names: Special Targets.). `.SILENT' is
-essentially obsolete since `@' is more flexible.
-
-
-File: make.info, Node: Execution, Next: Parallel, Prev: Echoing, Up: Commands
-
-5.3 Command Execution
-=====================
-
-When it is time to execute commands to update a target, they are
-executed by invoking a new subshell for each command line. (In
-practice, `make' may take shortcuts that do not affect the results.)
-
- *Please note:* this implies that setting shell variables and
-invoking shell commands such as `cd' that set a context local to each
-process will not affect the following command lines.(1) If you want to
-use `cd' to affect the next statement, put both statements in a single
-command line. Then `make' will invoke one shell to run the entire
-line, and the shell will execute the statements in sequence. For
-example:
-
- foo : bar/lose
- cd $(@D) && gobble $(@F) > ../$@
-
-Here we use the shell AND operator (`&&') so that if the `cd' command
-fails, the script will fail without trying to invoke the `gobble'
-command in the wrong directory, which could cause problems (in this
-case it would certainly cause `../foo' to be truncated, at least).
-
-* Menu:
-
-* Choosing the Shell:: How `make' chooses the shell used
- to run commands.
-
- ---------- Footnotes ----------
-
- (1) On MS-DOS, the value of current working directory is *global*, so
-changing it _will_ affect the following command lines on those systems.
-
-
-File: make.info, Node: Choosing the Shell, Prev: Execution, Up: Execution
-
-5.3.1 Choosing the Shell
-------------------------
-
-The program used as the shell is taken from the variable `SHELL'. If
-this variable is not set in your makefile, the program `/bin/sh' is
-used as the shell.
-
- Unlike most variables, the variable `SHELL' is never set from the
-environment. This is because the `SHELL' environment variable is used
-to specify your personal choice of shell program for interactive use.
-It would be very bad for personal choices like this to affect the
-functioning of makefiles. *Note Variables from the Environment:
-Environment.
-
- Furthermore, when you do set `SHELL' in your makefile that value is
-_not_ exported in the environment to commands that `make' invokes.
-Instead, the value inherited from the user's environment, if any, is
-exported. You can override this behavior by explicitly exporting
-`SHELL' (*note Communicating Variables to a Sub-`make':
-Variables/Recursion.), forcing it to be passed in the environment to
-commands.
-
- However, on MS-DOS and MS-Windows the value of `SHELL' in the
-environment *is* used, since on those systems most users do not set
-this variable, and therefore it is most likely set specifically to be
-used by `make'. On MS-DOS, if the setting of `SHELL' is not suitable
-for `make', you can set the variable `MAKESHELL' to the shell that
-`make' should use; if set it will be used as the shell instead of the
-value of `SHELL'.
-
-Choosing a Shell in DOS and Windows
-...................................
-
-Choosing a shell in MS-DOS and MS-Windows is much more complex than on
-other systems.
-
- On MS-DOS, if `SHELL' is not set, the value of the variable
-`COMSPEC' (which is always set) is used instead.
-
- The processing of lines that set the variable `SHELL' in Makefiles
-is different on MS-DOS. The stock shell, `command.com', is
-ridiculously limited in its functionality and many users of `make' tend
-to install a replacement shell. Therefore, on MS-DOS, `make' examines
-the value of `SHELL', and changes its behavior based on whether it
-points to a Unix-style or DOS-style shell. This allows reasonable
-functionality even if `SHELL' points to `command.com'.
-
- If `SHELL' points to a Unix-style shell, `make' on MS-DOS
-additionally checks whether that shell can indeed be found; if not, it
-ignores the line that sets `SHELL'. In MS-DOS, GNU `make' searches for
-the shell in the following places:
-
- 1. In the precise place pointed to by the value of `SHELL'. For
- example, if the makefile specifies `SHELL = /bin/sh', `make' will
- look in the directory `/bin' on the current drive.
-
- 2. In the current directory.
-
- 3. In each of the directories in the `PATH' variable, in order.
-
-
- In every directory it examines, `make' will first look for the
-specific file (`sh' in the example above). If this is not found, it
-will also look in that directory for that file with one of the known
-extensions which identify executable files. For example `.exe',
-`.com', `.bat', `.btm', `.sh', and some others.
-
- If any of these attempts is successful, the value of `SHELL' will be
-set to the full pathname of the shell as found. However, if none of
-these is found, the value of `SHELL' will not be changed, and thus the
-line that sets it will be effectively ignored. This is so `make' will
-only support features specific to a Unix-style shell if such a shell is
-actually installed on the system where `make' runs.
-
- Note that this extended search for the shell is limited to the cases
-where `SHELL' is set from the Makefile; if it is set in the environment
-or command line, you are expected to set it to the full pathname of the
-shell, exactly as things are on Unix.
-
- The effect of the above DOS-specific processing is that a Makefile
-that contains `SHELL = /bin/sh' (as many Unix makefiles do), will work
-on MS-DOS unaltered if you have e.g. `sh.exe' installed in some
-directory along your `PATH'.
-
-
-File: make.info, Node: Parallel, Next: Errors, Prev: Execution, Up: Commands
-
-5.4 Parallel Execution
-======================
-
-GNU `make' knows how to execute several commands at once. Normally,
-`make' will execute only one command at a time, waiting for it to
-finish before executing the next. However, the `-j' or `--jobs' option
-tells `make' to execute many commands simultaneously.
-
- On MS-DOS, the `-j' option has no effect, since that system doesn't
-support multi-processing.
-
- If the `-j' option is followed by an integer, this is the number of
-commands to execute at once; this is called the number of "job slots".
-If there is nothing looking like an integer after the `-j' option,
-there is no limit on the number of job slots. The default number of job
-slots is one, which means serial execution (one thing at a time).
-
- One unpleasant consequence of running several commands
-simultaneously is that output generated by the commands appears
-whenever each command sends it, so messages from different commands may
-be interspersed.
-
- Another problem is that two processes cannot both take input from the
-same device; so to make sure that only one command tries to take input
-from the terminal at once, `make' will invalidate the standard input
-streams of all but one running command. This means that attempting to
-read from standard input will usually be a fatal error (a `Broken pipe'
-signal) for most child processes if there are several.
-
- It is unpredictable which command will have a valid standard input
-stream (which will come from the terminal, or wherever you redirect the
-standard input of `make'). The first command run will always get it
-first, and the first command started after that one finishes will get
-it next, and so on.
-
- We will change how this aspect of `make' works if we find a better
-alternative. In the mean time, you should not rely on any command using
-standard input at all if you are using the parallel execution feature;
-but if you are not using this feature, then standard input works
-normally in all commands.
-
- Finally, handling recursive `make' invocations raises issues. For
-more information on this, see *Note Communicating Options to a
-Sub-`make': Options/Recursion.
-
- If a command fails (is killed by a signal or exits with a nonzero
-status), and errors are not ignored for that command (*note Errors in
-Commands: Errors.), the remaining command lines to remake the same
-target will not be run. If a command fails and the `-k' or
-`--keep-going' option was not given (*note Summary of Options: Options
-Summary.), `make' aborts execution. If make terminates for any reason
-(including a signal) with child processes running, it waits for them to
-finish before actually exiting.
-
- When the system is heavily loaded, you will probably want to run
-fewer jobs than when it is lightly loaded. You can use the `-l' option
-to tell `make' to limit the number of jobs to run at once, based on the
-load average. The `-l' or `--max-load' option is followed by a
-floating-point number. For example,
-
- -l 2.5
-
-will not let `make' start more than one job if the load average is
-above 2.5. The `-l' option with no following number removes the load
-limit, if one was given with a previous `-l' option.
-
- More precisely, when `make' goes to start up a job, and it already
-has at least one job running, it checks the current load average; if it
-is not lower than the limit given with `-l', `make' waits until the load
-average goes below that limit, or until all the other jobs finish.
-
- By default, there is no load limit.
-
-
-File: make.info, Node: Errors, Next: Interrupts, Prev: Parallel, Up: Commands
-
-5.5 Errors in Commands
-======================
-
-After each shell command returns, `make' looks at its exit status. If
-the command completed successfully, the next command line is executed
-in a new shell; after the last command line is finished, the rule is
-finished.
-
- If there is an error (the exit status is nonzero), `make' gives up on
-the current rule, and perhaps on all rules.
-
- Sometimes the failure of a certain command does not indicate a
-problem. For example, you may use the `mkdir' command to ensure that a
-directory exists. If the directory already exists, `mkdir' will report
-an error, but you probably want `make' to continue regardless.
-
- To ignore errors in a command line, write a `-' at the beginning of
-the line's text (after the initial tab). The `-' is discarded before
-the command is passed to the shell for execution.
-
- For example,
-
- clean:
- -rm -f *.o
-
-This causes `rm' to continue even if it is unable to remove a file.
-
- When you run `make' with the `-i' or `--ignore-errors' flag, errors
-are ignored in all commands of all rules. A rule in the makefile for
-the special target `.IGNORE' has the same effect, if there are no
-prerequisites. These ways of ignoring errors are obsolete because `-'
-is more flexible.
-
- When errors are to be ignored, because of either a `-' or the `-i'
-flag, `make' treats an error return just like success, except that it
-prints out a message that tells you the status code the command exited
-with, and says that the error has been ignored.
-
- When an error happens that `make' has not been told to ignore, it
-implies that the current target cannot be correctly remade, and neither
-can any other that depends on it either directly or indirectly. No
-further commands will be executed for these targets, since their
-preconditions have not been achieved.
-
- Normally `make' gives up immediately in this circumstance, returning
-a nonzero status. However, if the `-k' or `--keep-going' flag is
-specified, `make' continues to consider the other prerequisites of the
-pending targets, remaking them if necessary, before it gives up and
-returns nonzero status. For example, after an error in compiling one
-object file, `make -k' will continue compiling other object files even
-though it already knows that linking them will be impossible. *Note
-Summary of Options: Options Summary.
-
- The usual behavior assumes that your purpose is to get the specified
-targets up to date; once `make' learns that this is impossible, it
-might as well report the failure immediately. The `-k' option says
-that the real purpose is to test as many of the changes made in the
-program as possible, perhaps to find several independent problems so
-that you can correct them all before the next attempt to compile. This
-is why Emacs' `compile' command passes the `-k' flag by default.
-
- Usually when a command fails, if it has changed the target file at
-all, the file is corrupted and cannot be used--or at least it is not
-completely updated. Yet the file's time stamp says that it is now up to
-date, so the next time `make' runs, it will not try to update that
-file. The situation is just the same as when the command is killed by a
-signal; *note Interrupts::. So generally the right thing to do is to
-delete the target file if the command fails after beginning to change
-the file. `make' will do this if `.DELETE_ON_ERROR' appears as a
-target. This is almost always what you want `make' to do, but it is
-not historical practice; so for compatibility, you must explicitly
-request it.
-
-
-File: make.info, Node: Interrupts, Next: Recursion, Prev: Errors, Up: Commands
-
-5.6 Interrupting or Killing `make'
-==================================
-
-If `make' gets a fatal signal while a command is executing, it may
-delete the target file that the command was supposed to update. This is
-done if the target file's last-modification time has changed since
-`make' first checked it.
-
- The purpose of deleting the target is to make sure that it is remade
-from scratch when `make' is next run. Why is this? Suppose you type
-`Ctrl-c' while a compiler is running, and it has begun to write an
-object file `foo.o'. The `Ctrl-c' kills the compiler, resulting in an
-incomplete file whose last-modification time is newer than the source
-file `foo.c'. But `make' also receives the `Ctrl-c' signal and deletes
-this incomplete file. If `make' did not do this, the next invocation
-of `make' would think that `foo.o' did not require updating--resulting
-in a strange error message from the linker when it tries to link an
-object file half of which is missing.
-
- You can prevent the deletion of a target file in this way by making
-the special target `.PRECIOUS' depend on it. Before remaking a target,
-`make' checks to see whether it appears on the prerequisites of
-`.PRECIOUS', and thereby decides whether the target should be deleted
-if a signal happens. Some reasons why you might do this are that the
-target is updated in some atomic fashion, or exists only to record a
-modification-time (its contents do not matter), or must exist at all
-times to prevent other sorts of trouble.
-
-
-File: make.info, Node: Recursion, Next: Sequences, Prev: Interrupts, Up: Commands
-
-5.7 Recursive Use of `make'
-===========================
-
-Recursive use of `make' means using `make' as a command in a makefile.
-This technique is useful when you want separate makefiles for various
-subsystems that compose a larger system. For example, suppose you have
-a subdirectory `subdir' which has its own makefile, and you would like
-the containing directory's makefile to run `make' on the subdirectory.
-You can do it by writing this:
-
- subsystem:
- cd subdir && $(MAKE)
-
-or, equivalently, this (*note Summary of Options: Options Summary.):
-
- subsystem:
- $(MAKE) -C subdir
-
- You can write recursive `make' commands just by copying this example,
-but there are many things to know about how they work and why, and about
-how the sub-`make' relates to the top-level `make'. You may also find
-it useful to declare targets that invoke recursive `make' commands as
-`.PHONY' (for more discussion on when this is useful, see *Note Phony
-Targets::).
-
- For your convenience, when GNU `make' starts (after it has processed
-any `-C' options) it sets the variable `CURDIR' to the pathname of the
-current working directory. This value is never touched by `make'
-again: in particular note that if you include files from other
-directories the value of `CURDIR' does not change. The value has the
-same precedence it would have if it were set in the makefile (by
-default, an environment variable `CURDIR' will not override this
-value). Note that setting this variable has no impact on the operation
-of `make' (it does not cause `make' to change its working directory,
-for example).
-
-* Menu:
-
-* MAKE Variable:: The special effects of using `$(MAKE)'.
-* Variables/Recursion:: How to communicate variables to a sub-`make'.
-* Options/Recursion:: How to communicate options to a sub-`make'.
-* -w Option:: How the `-w' or `--print-directory' option
- helps debug use of recursive `make' commands.
-
-
-File: make.info, Node: MAKE Variable, Next: Variables/Recursion, Prev: Recursion, Up: Recursion
-
-5.7.1 How the `MAKE' Variable Works
------------------------------------
-
-Recursive `make' commands should always use the variable `MAKE', not
-the explicit command name `make', as shown here:
-
- subsystem:
- cd subdir && $(MAKE)
-
- The value of this variable is the file name with which `make' was
-invoked. If this file name was `/bin/make', then the command executed
-is `cd subdir && /bin/make'. If you use a special version of `make' to
-run the top-level makefile, the same special version will be executed
-for recursive invocations.
-
- As a special feature, using the variable `MAKE' in the commands of a
-rule alters the effects of the `-t' (`--touch'), `-n' (`--just-print'),
-or `-q' (`--question') option. Using the `MAKE' variable has the same
-effect as using a `+' character at the beginning of the command line.
-*Note Instead of Executing the Commands: Instead of Execution. This
-special feature is only enabled if the `MAKE' variable appears directly
-in the command script: it does not apply if the `MAKE' variable is
-referenced through expansion of another variable. In the latter case
-you must use the `+' token to get these special effects.
-
- Consider the command `make -t' in the above example. (The `-t'
-option marks targets as up to date without actually running any
-commands; see *Note Instead of Execution::.) Following the usual
-definition of `-t', a `make -t' command in the example would create a
-file named `subsystem' and do nothing else. What you really want it to
-do is run `cd subdir && make -t'; but that would require executing the
-command, and `-t' says not to execute commands.
-
- The special feature makes this do what you want: whenever a command
-line of a rule contains the variable `MAKE', the flags `-t', `-n' and
-`-q' do not apply to that line. Command lines containing `MAKE' are
-executed normally despite the presence of a flag that causes most
-commands not to be run. The usual `MAKEFLAGS' mechanism passes the
-flags to the sub-`make' (*note Communicating Options to a Sub-`make':
-Options/Recursion.), so your request to touch the files, or print the
-commands, is propagated to the subsystem.
-
-
-File: make.info, Node: Variables/Recursion, Next: Options/Recursion, Prev: MAKE Variable, Up: Recursion
-
-5.7.2 Communicating Variables to a Sub-`make'
----------------------------------------------
-
-Variable values of the top-level `make' can be passed to the sub-`make'
-through the environment by explicit request. These variables are
-defined in the sub-`make' as defaults, but do not override what is
-specified in the makefile used by the sub-`make' makefile unless you
-use the `-e' switch (*note Summary of Options: Options Summary.).
-
- To pass down, or "export", a variable, `make' adds the variable and
-its value to the environment for running each command. The sub-`make',
-in turn, uses the environment to initialize its table of variable
-values. *Note Variables from the Environment: Environment.
-
- Except by explicit request, `make' exports a variable only if it is
-either defined in the environment initially or set on the command line,
-and if its name consists only of letters, numbers, and underscores.
-Some shells cannot cope with environment variable names consisting of
-characters other than letters, numbers, and underscores.
-
- The value of the `make' variable `SHELL' is not exported. Instead,
-the value of the `SHELL' variable from the invoking environment is
-passed to the sub-`make'. You can force `make' to export its value for
-`SHELL' by using the `export' directive, described below. *Note
-Choosing the Shell::.
-
- The special variable `MAKEFLAGS' is always exported (unless you
-unexport it). `MAKEFILES' is exported if you set it to anything.
-
- `make' automatically passes down variable values that were defined
-on the command line, by putting them in the `MAKEFLAGS' variable.
-*Note Options/Recursion::.
-
- Variables are _not_ normally passed down if they were created by
-default by `make' (*note Variables Used by Implicit Rules: Implicit
-Variables.). The sub-`make' will define these for itself.
-
- If you want to export specific variables to a sub-`make', use the
-`export' directive, like this:
-
- export VARIABLE ...
-
-If you want to _prevent_ a variable from being exported, use the
-`unexport' directive, like this:
-
- unexport VARIABLE ...
-
-In both of these forms, the arguments to `export' and `unexport' are
-expanded, and so could be variables or functions which expand to a
-(list of) variable names to be (un)exported.
-
- As a convenience, you can define a variable and export it at the same
-time by doing:
-
- export VARIABLE = value
-
-has the same result as:
-
- VARIABLE = value
- export VARIABLE
-
-and
-
- export VARIABLE := value
-
-has the same result as:
-
- VARIABLE := value
- export VARIABLE
-
- Likewise,
-
- export VARIABLE += value
-
-is just like:
-
- VARIABLE += value
- export VARIABLE
-
-*Note Appending More Text to Variables: Appending.
-
- You may notice that the `export' and `unexport' directives work in
-`make' in the same way they work in the shell, `sh'.
-
- If you want all variables to be exported by default, you can use
-`export' by itself:
-
- export
-
-This tells `make' that variables which are not explicitly mentioned in
-an `export' or `unexport' directive should be exported. Any variable
-given in an `unexport' directive will still _not_ be exported. If you
-use `export' by itself to export variables by default, variables whose
-names contain characters other than alphanumerics and underscores will
-not be exported unless specifically mentioned in an `export' directive.
-
- The behavior elicited by an `export' directive by itself was the
-default in older versions of GNU `make'. If your makefiles depend on
-this behavior and you want to be compatible with old versions of
-`make', you can write a rule for the special target
-`.EXPORT_ALL_VARIABLES' instead of using the `export' directive. This
-will be ignored by old `make's, while the `export' directive will cause
-a syntax error.
-
- Likewise, you can use `unexport' by itself to tell `make' _not_ to
-export variables by default. Since this is the default behavior, you
-would only need to do this if `export' had been used by itself earlier
-(in an included makefile, perhaps). You *cannot* use `export' and
-`unexport' by themselves to have variables exported for some commands
-and not for others. The last `export' or `unexport' directive that
-appears by itself determines the behavior for the entire run of `make'.
-
- As a special feature, the variable `MAKELEVEL' is changed when it is
-passed down from level to level. This variable's value is a string
-which is the depth of the level as a decimal number. The value is `0'
-for the top-level `make'; `1' for a sub-`make', `2' for a
-sub-sub-`make', and so on. The incrementation happens when `make' sets
-up the environment for a command.
-
- The main use of `MAKELEVEL' is to test it in a conditional directive
-(*note Conditional Parts of Makefiles: Conditionals.); this way you can
-write a makefile that behaves one way if run recursively and another
-way if run directly by you.
-
- You can use the variable `MAKEFILES' to cause all sub-`make'
-commands to use additional makefiles. The value of `MAKEFILES' is a
-whitespace-separated list of file names. This variable, if defined in
-the outer-level makefile, is passed down through the environment; then
-it serves as a list of extra makefiles for the sub-`make' to read
-before the usual or specified ones. *Note The Variable `MAKEFILES':
-MAKEFILES Variable.
-
-
-File: make.info, Node: Options/Recursion, Next: -w Option, Prev: Variables/Recursion, Up: Recursion
-
-5.7.3 Communicating Options to a Sub-`make'
--------------------------------------------
-
-Flags such as `-s' and `-k' are passed automatically to the sub-`make'
-through the variable `MAKEFLAGS'. This variable is set up
-automatically by `make' to contain the flag letters that `make'
-received. Thus, if you do `make -ks' then `MAKEFLAGS' gets the value
-`ks'.
-
- As a consequence, every sub-`make' gets a value for `MAKEFLAGS' in
-its environment. In response, it takes the flags from that value and
-processes them as if they had been given as arguments. *Note Summary
-of Options: Options Summary.
-
- Likewise variables defined on the command line are passed to the
-sub-`make' through `MAKEFLAGS'. Words in the value of `MAKEFLAGS' that
-contain `=', `make' treats as variable definitions just as if they
-appeared on the command line. *Note Overriding Variables: Overriding.
-
- The options `-C', `-f', `-o', and `-W' are not put into `MAKEFLAGS';
-these options are not passed down.
-
- The `-j' option is a special case (*note Parallel Execution:
-Parallel.). If you set it to some numeric value `N' and your operating
-system supports it (most any UNIX system will; others typically won't),
-the parent `make' and all the sub-`make's will communicate to ensure
-that there are only `N' jobs running at the same time between them all.
-Note that any job that is marked recursive (*note Instead of Executing
-the Commands: Instead of Execution.) doesn't count against the total
-jobs (otherwise we could get `N' sub-`make's running and have no slots
-left over for any real work!)
-
- If your operating system doesn't support the above communication,
-then `-j 1' is always put into `MAKEFLAGS' instead of the value you
-specified. This is because if the `-j' option were passed down to
-sub-`make's, you would get many more jobs running in parallel than you
-asked for. If you give `-j' with no numeric argument, meaning to run
-as many jobs as possible in parallel, this is passed down, since
-multiple infinities are no more than one.
-
- If you do not want to pass the other flags down, you must change the
-value of `MAKEFLAGS', like this:
-
- subsystem:
- cd subdir && $(MAKE) MAKEFLAGS=
-
- The command line variable definitions really appear in the variable
-`MAKEOVERRIDES', and `MAKEFLAGS' contains a reference to this variable.
-If you do want to pass flags down normally, but don't want to pass
-down the command line variable definitions, you can reset
-`MAKEOVERRIDES' to empty, like this:
-
- MAKEOVERRIDES =
-
-This is not usually useful to do. However, some systems have a small
-fixed limit on the size of the environment, and putting so much
-information into the value of `MAKEFLAGS' can exceed it. If you see
-the error message `Arg list too long', this may be the problem. (For
-strict compliance with POSIX.2, changing `MAKEOVERRIDES' does not
-affect `MAKEFLAGS' if the special target `.POSIX' appears in the
-makefile. You probably do not care about this.)
-
- A similar variable `MFLAGS' exists also, for historical
-compatibility. It has the same value as `MAKEFLAGS' except that it
-does not contain the command line variable definitions, and it always
-begins with a hyphen unless it is empty (`MAKEFLAGS' begins with a
-hyphen only when it begins with an option that has no single-letter
-version, such as `--warn-undefined-variables'). `MFLAGS' was
-traditionally used explicitly in the recursive `make' command, like
-this:
-
- subsystem:
- cd subdir && $(MAKE) $(MFLAGS)
-
-but now `MAKEFLAGS' makes this usage redundant. If you want your
-makefiles to be compatible with old `make' programs, use this
-technique; it will work fine with more modern `make' versions too.
-
- The `MAKEFLAGS' variable can also be useful if you want to have
-certain options, such as `-k' (*note Summary of Options: Options
-Summary.), set each time you run `make'. You simply put a value for
-`MAKEFLAGS' in your environment. You can also set `MAKEFLAGS' in a
-makefile, to specify additional flags that should also be in effect for
-that makefile. (Note that you cannot use `MFLAGS' this way. That
-variable is set only for compatibility; `make' does not interpret a
-value you set for it in any way.)
-
- When `make' interprets the value of `MAKEFLAGS' (either from the
-environment or from a makefile), it first prepends a hyphen if the value
-does not already begin with one. Then it chops the value into words
-separated by blanks, and parses these words as if they were options
-given on the command line (except that `-C', `-f', `-h', `-o', `-W',
-and their long-named versions are ignored; and there is no error for an
-invalid option).
-
- If you do put `MAKEFLAGS' in your environment, you should be sure not
-to include any options that will drastically affect the actions of
-`make' and undermine the purpose of makefiles and of `make' itself.
-For instance, the `-t', `-n', and `-q' options, if put in one of these
-variables, could have disastrous consequences and would certainly have
-at least surprising and probably annoying effects.
-
-
-File: make.info, Node: -w Option, Prev: Options/Recursion, Up: Recursion
-
-5.7.4 The `--print-directory' Option
-------------------------------------
-
-If you use several levels of recursive `make' invocations, the `-w' or
-`--print-directory' option can make the output a lot easier to
-understand by showing each directory as `make' starts processing it and
-as `make' finishes processing it. For example, if `make -w' is run in
-the directory `/u/gnu/make', `make' will print a line of the form:
-
- make: Entering directory `/u/gnu/make'.
-
-before doing anything else, and a line of the form:
-
- make: Leaving directory `/u/gnu/make'.
-
-when processing is completed.
-
- Normally, you do not need to specify this option because `make' does
-it for you: `-w' is turned on automatically when you use the `-C'
-option, and in sub-`make's. `make' will not automatically turn on `-w'
-if you also use `-s', which says to be silent, or if you use
-`--no-print-directory' to explicitly disable it.
-
-
-File: make.info, Node: Sequences, Next: Empty Commands, Prev: Recursion, Up: Commands
-
-5.8 Defining Canned Command Sequences
-=====================================
-
-When the same sequence of commands is useful in making various targets,
-you can define it as a canned sequence with the `define' directive, and
-refer to the canned sequence from the rules for those targets. The
-canned sequence is actually a variable, so the name must not conflict
-with other variable names.
-
- Here is an example of defining a canned sequence of commands:
-
- define run-yacc
- yacc $(firstword $^)
- mv y.tab.c $@
- endef
-
-Here `run-yacc' is the name of the variable being defined; `endef'
-marks the end of the definition; the lines in between are the commands.
-The `define' directive does not expand variable references and
-function calls in the canned sequence; the `$' characters, parentheses,
-variable names, and so on, all become part of the value of the variable
-you are defining. *Note Defining Variables Verbatim: Defining, for a
-complete explanation of `define'.
-
- The first command in this example runs Yacc on the first
-prerequisite of whichever rule uses the canned sequence. The output
-file from Yacc is always named `y.tab.c'. The second command moves the
-output to the rule's target file name.
-
- To use the canned sequence, substitute the variable into the
-commands of a rule. You can substitute it like any other variable
-(*note Basics of Variable References: Reference.). Because variables
-defined by `define' are recursively expanded variables, all the
-variable references you wrote inside the `define' are expanded now.
-For example:
-
- foo.c : foo.y
- $(run-yacc)
-
-`foo.y' will be substituted for the variable `$^' when it occurs in
-`run-yacc''s value, and `foo.c' for `$@'.
-
- This is a realistic example, but this particular one is not needed in
-practice because `make' has an implicit rule to figure out these
-commands based on the file names involved (*note Using Implicit Rules:
-Implicit Rules.).
-
- In command execution, each line of a canned sequence is treated just
-as if the line appeared on its own in the rule, preceded by a tab. In
-particular, `make' invokes a separate subshell for each line. You can
-use the special prefix characters that affect command lines (`@', `-',
-and `+') on each line of a canned sequence. *Note Writing the Commands
-in Rules: Commands. For example, using this canned sequence:
-
- define frobnicate
- @echo "frobnicating target $@"
- frob-step-1 $< -o $@-step-1
- frob-step-2 $@-step-1 -o $@
- endef
-
-`make' will not echo the first line, the `echo' command. But it _will_
-echo the following two command lines.
-
- On the other hand, prefix characters on the command line that refers
-to a canned sequence apply to every line in the sequence. So the rule:
-
- frob.out: frob.in
- @$(frobnicate)
-
-does not echo _any_ commands. (*Note Command Echoing: Echoing, for a
-full explanation of `@'.)
-
-
-File: make.info, Node: Empty Commands, Prev: Sequences, Up: Commands
-
-5.9 Using Empty Commands
-========================
-
-It is sometimes useful to define commands which do nothing. This is
-done simply by giving a command that consists of nothing but
-whitespace. For example:
-
- target: ;
-
-defines an empty command string for `target'. You could also use a
-line beginning with a tab character to define an empty command string,
-but this would be confusing because such a line looks empty.
-
- You may be wondering why you would want to define a command string
-that does nothing. The only reason this is useful is to prevent a
-target from getting implicit commands (from implicit rules or the
-`.DEFAULT' special target; *note Implicit Rules:: and *note Defining
-Last-Resort Default Rules: Last Resort.).
-
- You may be inclined to define empty command strings for targets that
-are not actual files, but only exist so that their prerequisites can be
-remade. However, this is not the best way to do that, because the
-prerequisites may not be remade properly if the target file actually
-does exist. *Note Phony Targets: Phony Targets, for a better way to do
-this.
-
-
-File: make.info, Node: Using Variables, Next: Conditionals, Prev: Commands, Up: Top
-
-6 How to Use Variables
-**********************
-
-A "variable" is a name defined in a makefile to represent a string of
-text, called the variable's "value". These values are substituted by
-explicit request into targets, prerequisites, commands, and other parts
-of the makefile. (In some other versions of `make', variables are
-called "macros".)
-
- Variables and functions in all parts of a makefile are expanded when
-read, except for the shell commands in rules, the right-hand sides of
-variable definitions using `=', and the bodies of variable definitions
-using the `define' directive.
-
- Variables can represent lists of file names, options to pass to
-compilers, programs to run, directories to look in for source files,
-directories to write output in, or anything else you can imagine.
-
- A variable name may be any sequence of characters not containing `:',
-`#', `=', or leading or trailing whitespace. However, variable names
-containing characters other than letters, numbers, and underscores
-should be avoided, as they may be given special meanings in the future,
-and with some shells they cannot be passed through the environment to a
-sub-`make' (*note Communicating Variables to a Sub-`make':
-Variables/Recursion.).
-
- Variable names are case-sensitive. The names `foo', `FOO', and
-`Foo' all refer to different variables.
-
- It is traditional to use upper case letters in variable names, but we
-recommend using lower case letters for variable names that serve
-internal purposes in the makefile, and reserving upper case for
-parameters that control implicit rules or for parameters that the user
-should override with command options (*note Overriding Variables:
-Overriding.).
-
- A few variables have names that are a single punctuation character or
-just a few characters. These are the "automatic variables", and they
-have particular specialized uses. *Note Automatic Variables::.
-
-* Menu:
-
-* Reference:: How to use the value of a variable.
-* Flavors:: Variables come in two flavors.
-* Advanced:: Advanced features for referencing a variable.
-* Values:: All the ways variables get their values.
-* Setting:: How to set a variable in the makefile.
-* Appending:: How to append more text to the old value
- of a variable.
-* Override Directive:: How to set a variable in the makefile even if
- the user has set it with a command argument.
-* Defining:: An alternate way to set a variable
- to a verbatim string.
-* Environment:: Variable values can come from the environment.
-* Target-specific:: Variable values can be defined on a per-target
- basis.
-* Pattern-specific:: Target-specific variable values can be applied
- to a group of targets that match a pattern.
-
-
-File: make.info, Node: Reference, Next: Flavors, Prev: Using Variables, Up: Using Variables
-
-6.1 Basics of Variable References
-=================================
-
-To substitute a variable's value, write a dollar sign followed by the
-name of the variable in parentheses or braces: either `$(foo)' or
-`${foo}' is a valid reference to the variable `foo'. This special
-significance of `$' is why you must write `$$' to have the effect of a
-single dollar sign in a file name or command.
-
- Variable references can be used in any context: targets,
-prerequisites, commands, most directives, and new variable values.
-Here is an example of a common case, where a variable holds the names
-of all the object files in a program:
-
- objects = program.o foo.o utils.o
- program : $(objects)
- cc -o program $(objects)
-
- $(objects) : defs.h
-
- Variable references work by strict textual substitution. Thus, the
-rule
-
- foo = c
- prog.o : prog.$(foo)
- $(foo)$(foo) -$(foo) prog.$(foo)
-
-could be used to compile a C program `prog.c'. Since spaces before the
-variable value are ignored in variable assignments, the value of `foo'
-is precisely `c'. (Don't actually write your makefiles this way!)
-
- A dollar sign followed by a character other than a dollar sign,
-open-parenthesis or open-brace treats that single character as the
-variable name. Thus, you could reference the variable `x' with `$x'.
-However, this practice is strongly discouraged, except in the case of
-the automatic variables (*note Automatic Variables::).
-
-
-File: make.info, Node: Flavors, Next: Advanced, Prev: Reference, Up: Using Variables
-
-6.2 The Two Flavors of Variables
-================================
-
-There are two ways that a variable in GNU `make' can have a value; we
-call them the two "flavors" of variables. The two flavors are
-distinguished in how they are defined and in what they do when expanded.
-
- The first flavor of variable is a "recursively expanded" variable.
-Variables of this sort are defined by lines using `=' (*note Setting
-Variables: Setting.) or by the `define' directive (*note Defining
-Variables Verbatim: Defining.). The value you specify is installed
-verbatim; if it contains references to other variables, these
-references are expanded whenever this variable is substituted (in the
-course of expanding some other string). When this happens, it is
-called "recursive expansion".
-
- For example,
-
- foo = $(bar)
- bar = $(ugh)
- ugh = Huh?
-
- all:;echo $(foo)
-
-will echo `Huh?': `$(foo)' expands to `$(bar)' which expands to
-`$(ugh)' which finally expands to `Huh?'.
-
- This flavor of variable is the only sort supported by other versions
-of `make'. It has its advantages and its disadvantages. An advantage
-(most would say) is that:
-
- CFLAGS = $(include_dirs) -O
- include_dirs = -Ifoo -Ibar
-
-will do what was intended: when `CFLAGS' is expanded in a command, it
-will expand to `-Ifoo -Ibar -O'. A major disadvantage is that you
-cannot append something on the end of a variable, as in
-
- CFLAGS = $(CFLAGS) -O
-
-because it will cause an infinite loop in the variable expansion.
-(Actually `make' detects the infinite loop and reports an error.)
-
- Another disadvantage is that any functions (*note Functions for
-Transforming Text: Functions.) referenced in the definition will be
-executed every time the variable is expanded. This makes `make' run
-slower; worse, it causes the `wildcard' and `shell' functions to give
-unpredictable results because you cannot easily control when they are
-called, or even how many times.
-
- To avoid all the problems and inconveniences of recursively expanded
-variables, there is another flavor: simply expanded variables.
-
- "Simply expanded variables" are defined by lines using `:=' (*note
-Setting Variables: Setting.). The value of a simply expanded variable
-is scanned once and for all, expanding any references to other
-variables and functions, when the variable is defined. The actual
-value of the simply expanded variable is the result of expanding the
-text that you write. It does not contain any references to other
-variables; it contains their values _as of the time this variable was
-defined_. Therefore,
-
- x := foo
- y := $(x) bar
- x := later
-
-is equivalent to
-
- y := foo bar
- x := later
-
- When a simply expanded variable is referenced, its value is
-substituted verbatim.
-
- Here is a somewhat more complicated example, illustrating the use of
-`:=' in conjunction with the `shell' function. (*Note The `shell'
-Function: Shell Function.) This example also shows use of the variable
-`MAKELEVEL', which is changed when it is passed down from level to
-level. (*Note Communicating Variables to a Sub-`make':
-Variables/Recursion, for information about `MAKELEVEL'.)
-
- ifeq (0,${MAKELEVEL})
- whoami := $(shell whoami)
- host-type := $(shell arch)
- MAKE := ${MAKE} host-type=${host-type} whoami=${whoami}
- endif
-
-An advantage of this use of `:=' is that a typical `descend into a
-directory' command then looks like this:
-
- ${subdirs}:
- ${MAKE} -C $@ all
-
- Simply expanded variables generally make complicated makefile
-programming more predictable because they work like variables in most
-programming languages. They allow you to redefine a variable using its
-own value (or its value processed in some way by one of the expansion
-functions) and to use the expansion functions much more efficiently
-(*note Functions for Transforming Text: Functions.).
-
- You can also use them to introduce controlled leading whitespace into
-variable values. Leading whitespace characters are discarded from your
-input before substitution of variable references and function calls;
-this means you can include leading spaces in a variable value by
-protecting them with variable references, like this:
-
- nullstring :=
- space := $(nullstring) # end of the line
-
-Here the value of the variable `space' is precisely one space. The
-comment `# end of the line' is included here just for clarity. Since
-trailing space characters are _not_ stripped from variable values, just
-a space at the end of the line would have the same effect (but be
-rather hard to read). If you put whitespace at the end of a variable
-value, it is a good idea to put a comment like that at the end of the
-line to make your intent clear. Conversely, if you do _not_ want any
-whitespace characters at the end of your variable value, you must
-remember not to put a random comment on the end of the line after some
-whitespace, such as this:
-
- dir := /foo/bar # directory to put the frobs in
-
-Here the value of the variable `dir' is `/foo/bar ' (with four
-trailing spaces), which was probably not the intention. (Imagine
-something like `$(dir)/file' with this definition!)
-
- There is another assignment operator for variables, `?='. This is
-called a conditional variable assignment operator, because it only has
-an effect if the variable is not yet defined. This statement:
-
- FOO ?= bar
-
-is exactly equivalent to this (*note The `origin' Function: Origin
-Function.):
-
- ifeq ($(origin FOO), undefined)
- FOO = bar
- endif
-
- Note that a variable set to an empty value is still defined, so `?='
-will not set that variable.
-
-
-File: make.info, Node: Advanced, Next: Values, Prev: Flavors, Up: Using Variables
-
-6.3 Advanced Features for Reference to Variables
-================================================
-
-This section describes some advanced features you can use to reference
-variables in more flexible ways.
-
-* Menu:
-
-* Substitution Refs:: Referencing a variable with
- substitutions on the value.
-* Computed Names:: Computing the name of the variable to refer to.
-
-
-File: make.info, Node: Substitution Refs, Next: Computed Names, Prev: Advanced, Up: Advanced
-
-6.3.1 Substitution References
------------------------------
-
-A "substitution reference" substitutes the value of a variable with
-alterations that you specify. It has the form `$(VAR:A=B)' (or
-`${VAR:A=B}') and its meaning is to take the value of the variable VAR,
-replace every A at the end of a word with B in that value, and
-substitute the resulting string.
-
- When we say "at the end of a word", we mean that A must appear
-either followed by whitespace or at the end of the value in order to be
-replaced; other occurrences of A in the value are unaltered. For
-example:
-
- foo := a.o b.o c.o
- bar := $(foo:.o=.c)
-
-sets `bar' to `a.c b.c c.c'. *Note Setting Variables: Setting.
-
- A substitution reference is actually an abbreviation for use of the
-`patsubst' expansion function (*note Functions for String Substitution
-and Analysis: Text Functions.). We provide substitution references as
-well as `patsubst' for compatibility with other implementations of
-`make'.
-
- Another type of substitution reference lets you use the full power of
-the `patsubst' function. It has the same form `$(VAR:A=B)' described
-above, except that now A must contain a single `%' character. This
-case is equivalent to `$(patsubst A,B,$(VAR))'. *Note Functions for
-String Substitution and Analysis: Text Functions, for a description of
-the `patsubst' function.
-
-For example:
-
- foo := a.o b.o c.o
- bar := $(foo:%.o=%.c)
-
-sets `bar' to `a.c b.c c.c'.
-
-
-File: make.info, Node: Computed Names, Prev: Substitution Refs, Up: Advanced
-
-6.3.2 Computed Variable Names
------------------------------
-
-Computed variable names are a complicated concept needed only for
-sophisticated makefile programming. For most purposes you need not
-consider them, except to know that making a variable with a dollar sign
-in its name might have strange results. However, if you are the type
-that wants to understand everything, or you are actually interested in
-what they do, read on.
-
- Variables may be referenced inside the name of a variable. This is
-called a "computed variable name" or a "nested variable reference".
-For example,
-
- x = y
- y = z
- a := $($(x))
-
-defines `a' as `z': the `$(x)' inside `$($(x))' expands to `y', so
-`$($(x))' expands to `$(y)' which in turn expands to `z'. Here the
-name of the variable to reference is not stated explicitly; it is
-computed by expansion of `$(x)'. The reference `$(x)' here is nested
-within the outer variable reference.
-
- The previous example shows two levels of nesting, but any number of
-levels is possible. For example, here are three levels:
-
- x = y
- y = z
- z = u
- a := $($($(x)))
-
-Here the innermost `$(x)' expands to `y', so `$($(x))' expands to
-`$(y)' which in turn expands to `z'; now we have `$(z)', which becomes
-`u'.
-
- References to recursively-expanded variables within a variable name
-are reexpanded in the usual fashion. For example:
-
- x = $(y)
- y = z
- z = Hello
- a := $($(x))
-
-defines `a' as `Hello': `$($(x))' becomes `$($(y))' which becomes
-`$(z)' which becomes `Hello'.
-
- Nested variable references can also contain modified references and
-function invocations (*note Functions for Transforming Text:
-Functions.), just like any other reference. For example, using the
-`subst' function (*note Functions for String Substitution and Analysis:
-Text Functions.):
-
- x = variable1
- variable2 := Hello
- y = $(subst 1,2,$(x))
- z = y
- a := $($($(z)))
-
-eventually defines `a' as `Hello'. It is doubtful that anyone would
-ever want to write a nested reference as convoluted as this one, but it
-works: `$($($(z)))' expands to `$($(y))' which becomes `$($(subst
-1,2,$(x)))'. This gets the value `variable1' from `x' and changes it
-by substitution to `variable2', so that the entire string becomes
-`$(variable2)', a simple variable reference whose value is `Hello'.
-
- A computed variable name need not consist entirely of a single
-variable reference. It can contain several variable references, as
-well as some invariant text. For example,
-
- a_dirs := dira dirb
- 1_dirs := dir1 dir2
-
- a_files := filea fileb
- 1_files := file1 file2
-
- ifeq "$(use_a)" "yes"
- a1 := a
- else
- a1 := 1
- endif
-
- ifeq "$(use_dirs)" "yes"
- df := dirs
- else
- df := files
- endif
-
- dirs := $($(a1)_$(df))
-
-will give `dirs' the same value as `a_dirs', `1_dirs', `a_files' or
-`1_files' depending on the settings of `use_a' and `use_dirs'.
-
- Computed variable names can also be used in substitution references:
-
- a_objects := a.o b.o c.o
- 1_objects := 1.o 2.o 3.o
-
- sources := $($(a1)_objects:.o=.c)
-
-defines `sources' as either `a.c b.c c.c' or `1.c 2.c 3.c', depending
-on the value of `a1'.
-
- The only restriction on this sort of use of nested variable
-references is that they cannot specify part of the name of a function
-to be called. This is because the test for a recognized function name
-is done before the expansion of nested references. For example,
-
- ifdef do_sort
- func := sort
- else
- func := strip
- endif
-
- bar := a d b g q c
-
- foo := $($(func) $(bar))
-
-attempts to give `foo' the value of the variable `sort a d b g q c' or
-`strip a d b g q c', rather than giving `a d b g q c' as the argument
-to either the `sort' or the `strip' function. This restriction could
-be removed in the future if that change is shown to be a good idea.
-
- You can also use computed variable names in the left-hand side of a
-variable assignment, or in a `define' directive, as in:
-
- dir = foo
- $(dir)_sources := $(wildcard $(dir)/*.c)
- define $(dir)_print
- lpr $($(dir)_sources)
- endef
-
-This example defines the variables `dir', `foo_sources', and
-`foo_print'.
-
- Note that "nested variable references" are quite different from
-"recursively expanded variables" (*note The Two Flavors of Variables:
-Flavors.), though both are used together in complex ways when doing
-makefile programming.
-
-
-File: make.info, Node: Values, Next: Setting, Prev: Advanced, Up: Using Variables
-
-6.4 How Variables Get Their Values
-==================================
-
-Variables can get values in several different ways:
-
- * You can specify an overriding value when you run `make'. *Note
- Overriding Variables: Overriding.
-
- * You can specify a value in the makefile, either with an assignment
- (*note Setting Variables: Setting.) or with a verbatim definition
- (*note Defining Variables Verbatim: Defining.).
-
- * Variables in the environment become `make' variables. *Note
- Variables from the Environment: Environment.
-
- * Several "automatic" variables are given new values for each rule.
- Each of these has a single conventional use. *Note Automatic
- Variables::.
-
- * Several variables have constant initial values. *Note Variables
- Used by Implicit Rules: Implicit Variables.
-
-
-File: make.info, Node: Setting, Next: Appending, Prev: Values, Up: Using Variables
-
-6.5 Setting Variables
-=====================
-
-To set a variable from the makefile, write a line starting with the
-variable name followed by `=' or `:='. Whatever follows the `=' or
-`:=' on the line becomes the value. For example,
-
- objects = main.o foo.o bar.o utils.o
-
-defines a variable named `objects'. Whitespace around the variable
-name and immediately after the `=' is ignored.
-
- Variables defined with `=' are "recursively expanded" variables.
-Variables defined with `:=' are "simply expanded" variables; these
-definitions can contain variable references which will be expanded
-before the definition is made. *Note The Two Flavors of Variables:
-Flavors.
-
- The variable name may contain function and variable references, which
-are expanded when the line is read to find the actual variable name to
-use.
-
- There is no limit on the length of the value of a variable except the
-amount of swapping space on the computer. When a variable definition is
-long, it is a good idea to break it into several lines by inserting
-backslash-newline at convenient places in the definition. This will not
-affect the functioning of `make', but it will make the makefile easier
-to read.
-
- Most variable names are considered to have the empty string as a
-value if you have never set them. Several variables have built-in
-initial values that are not empty, but you can set them in the usual
-ways (*note Variables Used by Implicit Rules: Implicit Variables.).
-Several special variables are set automatically to a new value for each
-rule; these are called the "automatic" variables (*note Automatic
-Variables::).
-
- If you'd like a variable to be set to a value only if it's not
-already set, then you can use the shorthand operator `?=' instead of
-`='. These two settings of the variable `FOO' are identical (*note The
-`origin' Function: Origin Function.):
-
- FOO ?= bar
-
-and
-
- ifeq ($(origin FOO), undefined)
- FOO = bar
- endif
-
-
-File: make.info, Node: Appending, Next: Override Directive, Prev: Setting, Up: Using Variables
-
-6.6 Appending More Text to Variables
-====================================
-
-Often it is useful to add more text to the value of a variable already
-defined. You do this with a line containing `+=', like this:
-
- objects += another.o
-
-This takes the value of the variable `objects', and adds the text
-`another.o' to it (preceded by a single space). Thus:
-
- objects = main.o foo.o bar.o utils.o
- objects += another.o
-
-sets `objects' to `main.o foo.o bar.o utils.o another.o'.
-
- Using `+=' is similar to:
-
- objects = main.o foo.o bar.o utils.o
- objects := $(objects) another.o
-
-but differs in ways that become important when you use more complex
-values.
-
- When the variable in question has not been defined before, `+=' acts
-just like normal `=': it defines a recursively-expanded variable.
-However, when there _is_ a previous definition, exactly what `+=' does
-depends on what flavor of variable you defined originally. *Note The
-Two Flavors of Variables: Flavors, for an explanation of the two
-flavors of variables.
-
- When you add to a variable's value with `+=', `make' acts
-essentially as if you had included the extra text in the initial
-definition of the variable. If you defined it first with `:=', making
-it a simply-expanded variable, `+=' adds to that simply-expanded
-definition, and expands the new text before appending it to the old
-value just as `:=' does (see *Note Setting Variables: Setting, for a
-full explanation of `:='). In fact,
-
- variable := value
- variable += more
-
-is exactly equivalent to:
-
-
- variable := value
- variable := $(variable) more
-
- On the other hand, when you use `+=' with a variable that you defined
-first to be recursively-expanded using plain `=', `make' does something
-a bit different. Recall that when you define a recursively-expanded
-variable, `make' does not expand the value you set for variable and
-function references immediately. Instead it stores the text verbatim,
-and saves these variable and function references to be expanded later,
-when you refer to the new variable (*note The Two Flavors of Variables:
-Flavors.). When you use `+=' on a recursively-expanded variable, it is
-this unexpanded text to which `make' appends the new text you specify.
-
- variable = value
- variable += more
-
-is roughly equivalent to:
-
- temp = value
- variable = $(temp) more
-
-except that of course it never defines a variable called `temp'. The
-importance of this comes when the variable's old value contains
-variable references. Take this common example:
-
- CFLAGS = $(includes) -O
- ...
- CFLAGS += -pg # enable profiling
-
-The first line defines the `CFLAGS' variable with a reference to another
-variable, `includes'. (`CFLAGS' is used by the rules for C
-compilation; *note Catalogue of Implicit Rules: Catalogue of Rules.)
-Using `=' for the definition makes `CFLAGS' a recursively-expanded
-variable, meaning `$(includes) -O' is _not_ expanded when `make'
-processes the definition of `CFLAGS'. Thus, `includes' need not be
-defined yet for its value to take effect. It only has to be defined
-before any reference to `CFLAGS'. If we tried to append to the value
-of `CFLAGS' without using `+=', we might do it like this:
-
- CFLAGS := $(CFLAGS) -pg # enable profiling
-
-This is pretty close, but not quite what we want. Using `:=' redefines
-`CFLAGS' as a simply-expanded variable; this means `make' expands the
-text `$(CFLAGS) -pg' before setting the variable. If `includes' is not
-yet defined, we get ` -O -pg', and a later definition of `includes'
-will have no effect. Conversely, by using `+=' we set `CFLAGS' to the
-_unexpanded_ value `$(includes) -O -pg'. Thus we preserve the
-reference to `includes', so if that variable gets defined at any later
-point, a reference like `$(CFLAGS)' still uses its value.
-
-
-File: make.info, Node: Override Directive, Next: Defining, Prev: Appending, Up: Using Variables
-
-6.7 The `override' Directive
-============================
-
-If a variable has been set with a command argument (*note Overriding
-Variables: Overriding.), then ordinary assignments in the makefile are
-ignored. If you want to set the variable in the makefile even though
-it was set with a command argument, you can use an `override'
-directive, which is a line that looks like this:
-
- override VARIABLE = VALUE
-
-or
-
- override VARIABLE := VALUE
-
- To append more text to a variable defined on the command line, use:
-
- override VARIABLE += MORE TEXT
-
-*Note Appending More Text to Variables: Appending.
-
- The `override' directive was not invented for escalation in the war
-between makefiles and command arguments. It was invented so you can
-alter and add to values that the user specifies with command arguments.
-
- For example, suppose you always want the `-g' switch when you run the
-C compiler, but you would like to allow the user to specify the other
-switches with a command argument just as usual. You could use this
-`override' directive:
-
- override CFLAGS += -g
-
- You can also use `override' directives with `define' directives.
-This is done as you might expect:
-
- override define foo
- bar
- endef
-
-*Note Defining Variables Verbatim: Defining.
-
-
-File: make.info, Node: Defining, Next: Environment, Prev: Override Directive, Up: Using Variables
-
-6.8 Defining Variables Verbatim
-===============================
-
-Another way to set the value of a variable is to use the `define'
-directive. This directive has an unusual syntax which allows newline
-characters to be included in the value, which is convenient for defining
-both canned sequences of commands (*note Defining Canned Command
-Sequences: Sequences.), and also sections of makefile syntax to use
-with `eval' (*note Eval Function::).
-
- The `define' directive is followed on the same line by the name of
-the variable and nothing more. The value to give the variable appears
-on the following lines. The end of the value is marked by a line
-containing just the word `endef'. Aside from this difference in
-syntax, `define' works just like `=': it creates a recursively-expanded
-variable (*note The Two Flavors of Variables: Flavors.). The variable
-name may contain function and variable references, which are expanded
-when the directive is read to find the actual variable name to use.
-
- You may nest `define' directives: `make' will keep track of nested
-directives and report an error if they are not all properly closed with
-`endef'. Note that lines beginning with tab characters are considered
-part of a command script, so any `define' or `endef' strings appearing
-on such a line will not be considered `make' operators.
-
- define two-lines
- echo foo
- echo $(bar)
- endef
-
- The value in an ordinary assignment cannot contain a newline; but the
-newlines that separate the lines of the value in a `define' become part
-of the variable's value (except for the final newline which precedes
-the `endef' and is not considered part of the value).
-
- When used in a command script, the previous example is functionally
-equivalent to this:
-
- two-lines = echo foo; echo $(bar)
-
-since two commands separated by semicolon behave much like two separate
-shell commands. However, note that using two separate lines means
-`make' will invoke the shell twice, running an independent subshell for
-each line. *Note Command Execution: Execution.
-
- If you want variable definitions made with `define' to take
-precedence over command-line variable definitions, you can use the
-`override' directive together with `define':
-
- override define two-lines
- foo
- $(bar)
- endef
-
-*Note The `override' Directive: Override Directive.
-
-
-File: make.info, Node: Environment, Next: Target-specific, Prev: Defining, Up: Using Variables
-
-6.9 Variables from the Environment
-==================================
-
-Variables in `make' can come from the environment in which `make' is
-run. Every environment variable that `make' sees when it starts up is
-transformed into a `make' variable with the same name and value.
-However, an explicit assignment in the makefile, or with a command
-argument, overrides the environment. (If the `-e' flag is specified,
-then values from the environment override assignments in the makefile.
-*Note Summary of Options: Options Summary. But this is not recommended
-practice.)
-
- Thus, by setting the variable `CFLAGS' in your environment, you can
-cause all C compilations in most makefiles to use the compiler switches
-you prefer. This is safe for variables with standard or conventional
-meanings because you know that no makefile will use them for other
-things. (Note this is not totally reliable; some makefiles set
-`CFLAGS' explicitly and therefore are not affected by the value in the
-environment.)
-
- When `make' runs a command script, variables defined in the makefile
-are placed into the environment of that command. This allows you to
-pass values to sub-`make' invocations (*note Recursive Use of `make':
-Recursion.). By default, only variables that came from the environment
-or the command line are passed to recursive invocations. You can use
-the `export' directive to pass other variables. *Note Communicating
-Variables to a Sub-`make': Variables/Recursion, for full details.
-
- Other use of variables from the environment is not recommended. It
-is not wise for makefiles to depend for their functioning on
-environment variables set up outside their control, since this would
-cause different users to get different results from the same makefile.
-This is against the whole purpose of most makefiles.
-
- Such problems would be especially likely with the variable `SHELL',
-which is normally present in the environment to specify the user's
-choice of interactive shell. It would be very undesirable for this
-choice to affect `make'; so, `make' handles the `SHELL' environment
-variable in a special way; see *Note Choosing the Shell::.
-
-
-File: make.info, Node: Target-specific, Next: Pattern-specific, Prev: Environment, Up: Using Variables
-
-6.10 Target-specific Variable Values
-====================================
-
-Variable values in `make' are usually global; that is, they are the
-same regardless of where they are evaluated (unless they're reset, of
-course). One exception to that is automatic variables (*note Automatic
-Variables::).
-
- The other exception is "target-specific variable values". This
-feature allows you to define different values for the same variable,
-based on the target that `make' is currently building. As with
-automatic variables, these values are only available within the context
-of a target's command script (and in other target-specific assignments).
-
- Set a target-specific variable value like this:
-
- TARGET ... : VARIABLE-ASSIGNMENT
-
-or like this:
-
- TARGET ... : override VARIABLE-ASSIGNMENT
-
-or like this:
-
- TARGET ... : export VARIABLE-ASSIGNMENT
-
- Multiple TARGET values create a target-specific variable value for
-each member of the target list individually.
-
- The VARIABLE-ASSIGNMENT can be any valid form of assignment;
-recursive (`='), static (`:='), appending (`+='), or conditional
-(`?='). All variables that appear within the VARIABLE-ASSIGNMENT are
-evaluated within the context of the target: thus, any
-previously-defined target-specific variable values will be in effect.
-Note that this variable is actually distinct from any "global" value:
-the two variables do not have to have the same flavor (recursive vs.
-static).
-
- Target-specific variables have the same priority as any other
-makefile variable. Variables provided on the command-line (and in the
-environment if the `-e' option is in force) will take precedence.
-Specifying the `override' directive will allow the target-specific
-variable value to be preferred.
-
- There is one more special feature of target-specific variables: when
-you define a target-specific variable that variable value is also in
-effect for all prerequisites of this target, and all their
-prerequisites, etc. (unless those prerequisites override that variable
-with their own target-specific variable value). So, for example, a
-statement like this:
-
- prog : CFLAGS = -g
- prog : prog.o foo.o bar.o
-
-will set `CFLAGS' to `-g' in the command script for `prog', but it will
-also set `CFLAGS' to `-g' in the command scripts that create `prog.o',
-`foo.o', and `bar.o', and any command scripts which create their
-prerequisites.
-
- Be aware that a given prerequisite will only be built once per
-invocation of make, at most. If the same file is a prerequisite of
-multiple targets, and each of those targets has a different value for
-the same target-specific variable, then the first target to be built
-will cause that prerequisite to be built and the prerequisite will
-inherit the target-specific value from the first target. It will
-ignore the target-specific values from any other targets.
-
-
-File: make.info, Node: Pattern-specific, Prev: Target-specific, Up: Using Variables
-
-6.11 Pattern-specific Variable Values
-=====================================
-
-In addition to target-specific variable values (*note Target-specific
-Variable Values: Target-specific.), GNU `make' supports
-pattern-specific variable values. In this form, the variable is
-defined for any target that matches the pattern specified. If a target
-matches more than one pattern, all the matching pattern-specific
-variables are interpreted in the order in which they were defined in
-the makefile, and collected together into one set. Variables defined
-in this way are searched after any target-specific variables defined
-explicitly for that target, and before target-specific variables
-defined for the parent target.
-
- Set a pattern-specific variable value like this:
-
- PATTERN ... : VARIABLE-ASSIGNMENT
-
-or like this:
-
- PATTERN ... : override VARIABLE-ASSIGNMENT
-
-where PATTERN is a %-pattern. As with target-specific variable values,
-multiple PATTERN values create a pattern-specific variable value for
-each pattern individually. The VARIABLE-ASSIGNMENT can be any valid
-form of assignment. Any command-line variable setting will take
-precedence, unless `override' is specified.
-
- For example:
-
- %.o : CFLAGS = -O
-
-will assign `CFLAGS' the value of `-O' for all targets matching the
-pattern `%.o'.
-
-
-File: make.info, Node: Conditionals, Next: Functions, Prev: Using Variables, Up: Top
-
-7 Conditional Parts of Makefiles
-********************************
-
-A "conditional" causes part of a makefile to be obeyed or ignored
-depending on the values of variables. Conditionals can compare the
-value of one variable to another, or the value of a variable to a
-constant string. Conditionals control what `make' actually "sees" in
-the makefile, so they _cannot_ be used to control shell commands at the
-time of execution.
-
-* Menu:
-
-* Conditional Example:: Example of a conditional
-* Conditional Syntax:: The syntax of conditionals.
-* Testing Flags:: Conditionals that test flags.
-
-
-File: make.info, Node: Conditional Example, Next: Conditional Syntax, Prev: Conditionals, Up: Conditionals
-
-7.1 Example of a Conditional
-============================
-
-The following example of a conditional tells `make' to use one set of
-libraries if the `CC' variable is `gcc', and a different set of
-libraries otherwise. It works by controlling which of two command
-lines will be used as the command for a rule. The result is that
-`CC=gcc' as an argument to `make' changes not only which compiler is
-used but also which libraries are linked.
-
- libs_for_gcc = -lgnu
- normal_libs =
-
- foo: $(objects)
- ifeq ($(CC),gcc)
- $(CC) -o foo $(objects) $(libs_for_gcc)
- else
- $(CC) -o foo $(objects) $(normal_libs)
- endif
-
- This conditional uses three directives: one `ifeq', one `else' and
-one `endif'.
-
- The `ifeq' directive begins the conditional, and specifies the
-condition. It contains two arguments, separated by a comma and
-surrounded by parentheses. Variable substitution is performed on both
-arguments and then they are compared. The lines of the makefile
-following the `ifeq' are obeyed if the two arguments match; otherwise
-they are ignored.
-
- The `else' directive causes the following lines to be obeyed if the
-previous conditional failed. In the example above, this means that the
-second alternative linking command is used whenever the first
-alternative is not used. It is optional to have an `else' in a
-conditional.
-
- The `endif' directive ends the conditional. Every conditional must
-end with an `endif'. Unconditional makefile text follows.
-
- As this example illustrates, conditionals work at the textual level:
-the lines of the conditional are treated as part of the makefile, or
-ignored, according to the condition. This is why the larger syntactic
-units of the makefile, such as rules, may cross the beginning or the
-end of the conditional.
-
- When the variable `CC' has the value `gcc', the above example has
-this effect:
-
- foo: $(objects)
- $(CC) -o foo $(objects) $(libs_for_gcc)
-
-When the variable `CC' has any other value, the effect is this:
-
- foo: $(objects)
- $(CC) -o foo $(objects) $(normal_libs)
-
- Equivalent results can be obtained in another way by
-conditionalizing a variable assignment and then using the variable
-unconditionally:
-
- libs_for_gcc = -lgnu
- normal_libs =
-
- ifeq ($(CC),gcc)
- libs=$(libs_for_gcc)
- else
- libs=$(normal_libs)
- endif
-
- foo: $(objects)
- $(CC) -o foo $(objects) $(libs)
-
-
-File: make.info, Node: Conditional Syntax, Next: Testing Flags, Prev: Conditional Example, Up: Conditionals
-
-7.2 Syntax of Conditionals
-==========================
-
-The syntax of a simple conditional with no `else' is as follows:
-
- CONDITIONAL-DIRECTIVE
- TEXT-IF-TRUE
- endif
-
-The TEXT-IF-TRUE may be any lines of text, to be considered as part of
-the makefile if the condition is true. If the condition is false, no
-text is used instead.
-
- The syntax of a complex conditional is as follows:
-
- CONDITIONAL-DIRECTIVE
- TEXT-IF-TRUE
- else
- TEXT-IF-FALSE
- endif
-
- or:
-
- CONDITIONAL-DIRECTIVE
- TEXT-IF-ONE-IS-TRUE
- else CONDITIONAL-DIRECTIVE
- TEXT-IF-TRUE
- else
- TEXT-IF-FALSE
- endif
-
-There can be as many "`else' CONDITIONAL-DIRECTIVE" clauses as
-necessary. Once a given condition is true, TEXT-IF-TRUE is used and no
-other clause is used; if no condition is true then TEXT-IF-FALSE is
-used. The TEXT-IF-TRUE and TEXT-IF-FALSE can be any number of lines of
-text.
-
- The syntax of the CONDITIONAL-DIRECTIVE is the same whether the
-conditional is simple or complex; after an `else' or not. There are
-four different directives that test different conditions. Here is a
-table of them:
-
-`ifeq (ARG1, ARG2)'
-`ifeq 'ARG1' 'ARG2''
-`ifeq "ARG1" "ARG2"'
-`ifeq "ARG1" 'ARG2''
-`ifeq 'ARG1' "ARG2"'
- Expand all variable references in ARG1 and ARG2 and compare them.
- If they are identical, the TEXT-IF-TRUE is effective; otherwise,
- the TEXT-IF-FALSE, if any, is effective.
-
- Often you want to test if a variable has a non-empty value. When
- the value results from complex expansions of variables and
- functions, expansions you would consider empty may actually
- contain whitespace characters and thus are not seen as empty.
- However, you can use the `strip' function (*note Text Functions::)
- to avoid interpreting whitespace as a non-empty value. For
- example:
-
- ifeq ($(strip $(foo)),)
- TEXT-IF-EMPTY
- endif
-
- will evaluate TEXT-IF-EMPTY even if the expansion of `$(foo)'
- contains whitespace characters.
-
-`ifneq (ARG1, ARG2)'
-`ifneq 'ARG1' 'ARG2''
-`ifneq "ARG1" "ARG2"'
-`ifneq "ARG1" 'ARG2''
-`ifneq 'ARG1' "ARG2"'
- Expand all variable references in ARG1 and ARG2 and compare them.
- If they are different, the TEXT-IF-TRUE is effective; otherwise,
- the TEXT-IF-FALSE, if any, is effective.
-
-`ifdef VARIABLE-NAME'
- The `ifdef' form takes the _name_ of a variable as its argument,
- not a reference to a variable. The value of that variable has a
- non-empty value, the TEXT-IF-TRUE is effective; otherwise, the
- TEXT-IF-FALSE, if any, is effective. Variables that have never
- been defined have an empty value. The text VARIABLE-NAME is
- expanded, so it could be a variable or function that expands to
- the name of a variable. For example:
-
- bar = true
- foo = bar
- ifdef $(foo)
- frobozz = yes
- endif
-
- The variable reference `$(foo)' is expanded, yielding `bar', which
- is considered to be the name of a variable. The variable `bar' is
- not expanded, but its value is examined to determine if it is
- non-empty.
-
- Note that `ifdef' only tests whether a variable has a value. It
- does not expand the variable to see if that value is nonempty.
- Consequently, tests using `ifdef' return true for all definitions
- except those like `foo ='. To test for an empty value, use
- `ifeq ($(foo),)'. For example,
-
- bar =
- foo = $(bar)
- ifdef foo
- frobozz = yes
- else
- frobozz = no
- endif
-
- sets `frobozz' to `yes', while:
-
- foo =
- ifdef foo
- frobozz = yes
- else
- frobozz = no
- endif
-
- sets `frobozz' to `no'.
-
-`ifndef VARIABLE-NAME'
- If the variable VARIABLE-NAME has an empty value, the TEXT-IF-TRUE
- is effective; otherwise, the TEXT-IF-FALSE, if any, is effective.
- The rules for expansion and testing of VARIABLE-NAME are identical
- to the `ifdef' directive.
-
- Extra spaces are allowed and ignored at the beginning of the
-conditional directive line, but a tab is not allowed. (If the line
-begins with a tab, it will be considered a command for a rule.) Aside
-from this, extra spaces or tabs may be inserted with no effect anywhere
-except within the directive name or within an argument. A comment
-starting with `#' may appear at the end of the line.
-
- The other two directives that play a part in a conditional are `else'
-and `endif'. Each of these directives is written as one word, with no
-arguments. Extra spaces are allowed and ignored at the beginning of the
-line, and spaces or tabs at the end. A comment starting with `#' may
-appear at the end of the line.
-
- Conditionals affect which lines of the makefile `make' uses. If the
-condition is true, `make' reads the lines of the TEXT-IF-TRUE as part
-of the makefile; if the condition is false, `make' ignores those lines
-completely. It follows that syntactic units of the makefile, such as
-rules, may safely be split across the beginning or the end of the
-conditional.
-
- `make' evaluates conditionals when it reads a makefile.
-Consequently, you cannot use automatic variables in the tests of
-conditionals because they are not defined until commands are run (*note
-Automatic Variables::).
-
- To prevent intolerable confusion, it is not permitted to start a
-conditional in one makefile and end it in another. However, you may
-write an `include' directive within a conditional, provided you do not
-attempt to terminate the conditional inside the included file.
-
-
-File: make.info, Node: Testing Flags, Prev: Conditional Syntax, Up: Conditionals
-
-7.3 Conditionals that Test Flags
-================================
-
-You can write a conditional that tests `make' command flags such as
-`-t' by using the variable `MAKEFLAGS' together with the `findstring'
-function (*note Functions for String Substitution and Analysis: Text
-Functions.). This is useful when `touch' is not enough to make a file
-appear up to date.
-
- The `findstring' function determines whether one string appears as a
-substring of another. If you want to test for the `-t' flag, use `t'
-as the first string and the value of `MAKEFLAGS' as the other.
-
- For example, here is how to arrange to use `ranlib -t' to finish
-marking an archive file up to date:
-
- archive.a: ...
- ifneq (,$(findstring t,$(MAKEFLAGS)))
- +touch archive.a
- +ranlib -t archive.a
- else
- ranlib archive.a
- endif
-
-The `+' prefix marks those command lines as "recursive" so that they
-will be executed despite use of the `-t' flag. *Note Recursive Use of
-`make': Recursion.
-
-
-File: make.info, Node: Functions, Next: Running, Prev: Conditionals, Up: Top
-
-8 Functions for Transforming Text
-*********************************
-
-"Functions" allow you to do text processing in the makefile to compute
-the files to operate on or the commands to use. You use a function in a
-"function call", where you give the name of the function and some text
-(the "arguments") for the function to operate on. The result of the
-function's processing is substituted into the makefile at the point of
-the call, just as a variable might be substituted.
-
-* Menu:
-
-* Syntax of Functions:: How to write a function call.
-* Text Functions:: General-purpose text manipulation functions.
-* File Name Functions:: Functions for manipulating file names.
-* Conditional Functions:: Functions that implement conditions.
-* Foreach Function:: Repeat some text with controlled variation.
-* Call Function:: Expand a user-defined function.
-* Value Function:: Return the un-expanded value of a variable.
-* Eval Function:: Evaluate the arguments as makefile syntax.
-* Origin Function:: Find where a variable got its value.
-* Flavor Function:: Find out the flavor of a variable.
-* Shell Function:: Substitute the output of a shell command.
-* Make Control Functions:: Functions that control how make runs.
-
-
-File: make.info, Node: Syntax of Functions, Next: Text Functions, Prev: Functions, Up: Functions
-
-8.1 Function Call Syntax
-========================
-
-A function call resembles a variable reference. It looks like this:
-
- $(FUNCTION ARGUMENTS)
-
-or like this:
-
- ${FUNCTION ARGUMENTS}
-
- Here FUNCTION is a function name; one of a short list of names that
-are part of `make'. You can also essentially create your own functions
-by using the `call' builtin function.
-
- The ARGUMENTS are the arguments of the function. They are separated
-from the function name by one or more spaces or tabs, and if there is
-more than one argument, then they are separated by commas. Such
-whitespace and commas are not part of an argument's value. The
-delimiters which you use to surround the function call, whether
-parentheses or braces, can appear in an argument only in matching pairs;
-the other kind of delimiters may appear singly. If the arguments
-themselves contain other function calls or variable references, it is
-wisest to use the same kind of delimiters for all the references; write
-`$(subst a,b,$(x))', not `$(subst a,b,${x})'. This is because it is
-clearer, and because only one type of delimiter is matched to find the
-end of the reference.
-
- The text written for each argument is processed by substitution of
-variables and function calls to produce the argument value, which is
-the text on which the function acts. The substitution is done in the
-order in which the arguments appear.
-
- Commas and unmatched parentheses or braces cannot appear in the text
-of an argument as written; leading spaces cannot appear in the text of
-the first argument as written. These characters can be put into the
-argument value by variable substitution. First define variables
-`comma' and `space' whose values are isolated comma and space
-characters, then substitute these variables where such characters are
-wanted, like this:
-
- comma:= ,
- empty:=
- space:= $(empty) $(empty)
- foo:= a b c
- bar:= $(subst $(space),$(comma),$(foo))
- # bar is now `a,b,c'.
-
-Here the `subst' function replaces each space with a comma, through the
-value of `foo', and substitutes the result.
-
-
-File: make.info, Node: Text Functions, Next: File Name Functions, Prev: Syntax of Functions, Up: Functions
-
-8.2 Functions for String Substitution and Analysis
-==================================================
-
-Here are some functions that operate on strings:
-
-`$(subst FROM,TO,TEXT)'
- Performs a textual replacement on the text TEXT: each occurrence
- of FROM is replaced by TO. The result is substituted for the
- function call. For example,
-
- $(subst ee,EE,feet on the street)
-
- substitutes the string `fEEt on the strEEt'.
-
-`$(patsubst PATTERN,REPLACEMENT,TEXT)'
- Finds whitespace-separated words in TEXT that match PATTERN and
- replaces them with REPLACEMENT. Here PATTERN may contain a `%'
- which acts as a wildcard, matching any number of any characters
- within a word. If REPLACEMENT also contains a `%', the `%' is
- replaced by the text that matched the `%' in PATTERN. Only the
- first `%' in the PATTERN and REPLACEMENT is treated this way; any
- subsequent `%' is unchanged.
-
- `%' characters in `patsubst' function invocations can be quoted
- with preceding backslashes (`\'). Backslashes that would
- otherwise quote `%' characters can be quoted with more backslashes.
- Backslashes that quote `%' characters or other backslashes are
- removed from the pattern before it is compared file names or has a
- stem substituted into it. Backslashes that are not in danger of
- quoting `%' characters go unmolested. For example, the pattern
- `the\%weird\\%pattern\\' has `the%weird\' preceding the operative
- `%' character, and `pattern\\' following it. The final two
- backslashes are left alone because they cannot affect any `%'
- character.
-
- Whitespace between words is folded into single space characters;
- leading and trailing whitespace is discarded.
-
- For example,
-
- $(patsubst %.c,%.o,x.c.c bar.c)
-
- produces the value `x.c.o bar.o'.
-
- Substitution references (*note Substitution References:
- Substitution Refs.) are a simpler way to get the effect of the
- `patsubst' function:
-
- $(VAR:PATTERN=REPLACEMENT)
-
- is equivalent to
-
- $(patsubst PATTERN,REPLACEMENT,$(VAR))
-
- The second shorthand simplifies one of the most common uses of
- `patsubst': replacing the suffix at the end of file names.
-
- $(VAR:SUFFIX=REPLACEMENT)
-
- is equivalent to
-
- $(patsubst %SUFFIX,%REPLACEMENT,$(VAR))
-
- For example, you might have a list of object files:
-
- objects = foo.o bar.o baz.o
-
- To get the list of corresponding source files, you could simply
- write:
-
- $(objects:.o=.c)
-
- instead of using the general form:
-
- $(patsubst %.o,%.c,$(objects))
-
-`$(strip STRING)'
- Removes leading and trailing whitespace from STRING and replaces
- each internal sequence of one or more whitespace characters with a
- single space. Thus, `$(strip a b c )' results in `a b c'.
-
- The function `strip' can be very useful when used in conjunction
- with conditionals. When comparing something with the empty string
- `' using `ifeq' or `ifneq', you usually want a string of just
- whitespace to match the empty string (*note Conditionals::).
-
- Thus, the following may fail to have the desired results:
-
- .PHONY: all
- ifneq "$(needs_made)" ""
- all: $(needs_made)
- else
- all:;@echo 'Nothing to make!'
- endif
-
- Replacing the variable reference `$(needs_made)' with the function
- call `$(strip $(needs_made))' in the `ifneq' directive would make
- it more robust.
-
-`$(findstring FIND,IN)'
- Searches IN for an occurrence of FIND. If it occurs, the value is
- FIND; otherwise, the value is empty. You can use this function in
- a conditional to test for the presence of a specific substring in
- a given string. Thus, the two examples,
-
- $(findstring a,a b c)
- $(findstring a,b c)
-
- produce the values `a' and `' (the empty string), respectively.
- *Note Testing Flags::, for a practical application of `findstring'.
-
-`$(filter PATTERN...,TEXT)'
- Returns all whitespace-separated words in TEXT that _do_ match any
- of the PATTERN words, removing any words that _do not_ match. The
- patterns are written using `%', just like the patterns used in the
- `patsubst' function above.
-
- The `filter' function can be used to separate out different types
- of strings (such as file names) in a variable. For example:
-
- sources := foo.c bar.c baz.s ugh.h
- foo: $(sources)
- cc $(filter %.c %.s,$(sources)) -o foo
-
- says that `foo' depends of `foo.c', `bar.c', `baz.s' and `ugh.h'
- but only `foo.c', `bar.c' and `baz.s' should be specified in the
- command to the compiler.
-
-`$(filter-out PATTERN...,TEXT)'
- Returns all whitespace-separated words in TEXT that _do not_ match
- any of the PATTERN words, removing the words that _do_ match one
- or more. This is the exact opposite of the `filter' function.
-
- For example, given:
-
- objects=main1.o foo.o main2.o bar.o
- mains=main1.o main2.o
-
- the following generates a list which contains all the object files
- not in `mains':
-
- $(filter-out $(mains),$(objects))
-
-`$(sort LIST)'
- Sorts the words of LIST in lexical order, removing duplicate
- words. The output is a list of words separated by single spaces.
- Thus,
-
- $(sort foo bar lose)
-
- returns the value `bar foo lose'.
-
- Incidentally, since `sort' removes duplicate words, you can use it
- for this purpose even if you don't care about the sort order.
-
-`$(word N,TEXT)'
- Returns the Nth word of TEXT. The legitimate values of N start
- from 1. If N is bigger than the number of words in TEXT, the
- value is empty. For example,
-
- $(word 2, foo bar baz)
-
- returns `bar'.
-
-`$(wordlist S,E,TEXT)'
- Returns the list of words in TEXT starting with word S and ending
- with word E (inclusive). The legitimate values of S start from 1;
- E may start from 0. If S is bigger than the number of words in
- TEXT, the value is empty. If E is bigger than the number of words
- in TEXT, words up to the end of TEXT are returned. If S is
- greater than E, nothing is returned. For example,
-
- $(wordlist 2, 3, foo bar baz)
-
- returns `bar baz'.
-
-`$(words TEXT)'
- Returns the number of words in TEXT. Thus, the last word of TEXT
- is `$(word $(words TEXT),TEXT)'.
-
-`$(firstword NAMES...)'
- The argument NAMES is regarded as a series of names, separated by
- whitespace. The value is the first name in the series. The rest
- of the names are ignored.
-
- For example,
-
- $(firstword foo bar)
-
- produces the result `foo'. Although `$(firstword TEXT)' is the
- same as `$(word 1,TEXT)', the `firstword' function is retained for
- its simplicity.
-
-`$(lastword NAMES...)'
- The argument NAMES is regarded as a series of names, separated by
- whitespace. The value is the last name in the series.
-
- For example,
-
- $(lastword foo bar)
-
- produces the result `bar'. Although `$(lastword TEXT)' is the
- same as `$(word $(words TEXT),TEXT)', the `lastword' function was
- added for its simplicity and better performance.
-
- Here is a realistic example of the use of `subst' and `patsubst'.
-Suppose that a makefile uses the `VPATH' variable to specify a list of
-directories that `make' should search for prerequisite files (*note
-`VPATH' Search Path for All Prerequisites: General Search.). This
-example shows how to tell the C compiler to search for header files in
-the same list of directories.
-
- The value of `VPATH' is a list of directories separated by colons,
-such as `src:../headers'. First, the `subst' function is used to
-change the colons to spaces:
-
- $(subst :, ,$(VPATH))
-
-This produces `src ../headers'. Then `patsubst' is used to turn each
-directory name into a `-I' flag. These can be added to the value of
-the variable `CFLAGS', which is passed automatically to the C compiler,
-like this:
-
- override CFLAGS += $(patsubst %,-I%,$(subst :, ,$(VPATH)))
-
-The effect is to append the text `-Isrc -I../headers' to the previously
-given value of `CFLAGS'. The `override' directive is used so that the
-new value is assigned even if the previous value of `CFLAGS' was
-specified with a command argument (*note The `override' Directive:
-Override Directive.).
-
-
-File: make.info, Node: File Name Functions, Next: Conditional Functions, Prev: Text Functions, Up: Functions
-
-8.3 Functions for File Names
-============================
-
-Several of the built-in expansion functions relate specifically to
-taking apart file names or lists of file names.
-
- Each of the following functions performs a specific transformation
-on a file name. The argument of the function is regarded as a series
-of file names, separated by whitespace. (Leading and trailing
-whitespace is ignored.) Each file name in the series is transformed in
-the same way and the results are concatenated with single spaces
-between them.
-
-`$(dir NAMES...)'
- Extracts the directory-part of each file name in NAMES. The
- directory-part of the file name is everything up through (and
- including) the last slash in it. If the file name contains no
- slash, the directory part is the string `./'. For example,
-
- $(dir src/foo.c hacks)
-
- produces the result `src/ ./'.
-
-`$(notdir NAMES...)'
- Extracts all but the directory-part of each file name in NAMES.
- If the file name contains no slash, it is left unchanged.
- Otherwise, everything through the last slash is removed from it.
-
- A file name that ends with a slash becomes an empty string. This
- is unfortunate, because it means that the result does not always
- have the same number of whitespace-separated file names as the
- argument had; but we do not see any other valid alternative.
-
- For example,
-
- $(notdir src/foo.c hacks)
-
- produces the result `foo.c hacks'.
-
-`$(suffix NAMES...)'
- Extracts the suffix of each file name in NAMES. If the file name
- contains a period, the suffix is everything starting with the last
- period. Otherwise, the suffix is the empty string. This
- frequently means that the result will be empty when NAMES is not,
- and if NAMES contains multiple file names, the result may contain
- fewer file names.
-
- For example,
-
- $(suffix src/foo.c src-1.0/bar.c hacks)
-
- produces the result `.c .c'.
-
-`$(basename NAMES...)'
- Extracts all but the suffix of each file name in NAMES. If the
- file name contains a period, the basename is everything starting
- up to (and not including) the last period. Periods in the
- directory part are ignored. If there is no period, the basename
- is the entire file name. For example,
-
- $(basename src/foo.c src-1.0/bar hacks)
-
- produces the result `src/foo src-1.0/bar hacks'.
-
-`$(addsuffix SUFFIX,NAMES...)'
- The argument NAMES is regarded as a series of names, separated by
- whitespace; SUFFIX is used as a unit. The value of SUFFIX is
- appended to the end of each individual name and the resulting
- larger names are concatenated with single spaces between them.
- For example,
-
- $(addsuffix .c,foo bar)
-
- produces the result `foo.c bar.c'.
-
-`$(addprefix PREFIX,NAMES...)'
- The argument NAMES is regarded as a series of names, separated by
- whitespace; PREFIX is used as a unit. The value of PREFIX is
- prepended to the front of each individual name and the resulting
- larger names are concatenated with single spaces between them.
- For example,
-
- $(addprefix src/,foo bar)
-
- produces the result `src/foo src/bar'.
-
-`$(join LIST1,LIST2)'
- Concatenates the two arguments word by word: the two first words
- (one from each argument) concatenated form the first word of the
- result, the two second words form the second word of the result,
- and so on. So the Nth word of the result comes from the Nth word
- of each argument. If one argument has more words that the other,
- the extra words are copied unchanged into the result.
-
- For example, `$(join a b,.c .o)' produces `a.c b.o'.
-
- Whitespace between the words in the lists is not preserved; it is
- replaced with a single space.
-
- This function can merge the results of the `dir' and `notdir'
- functions, to produce the original list of files which was given
- to those two functions.
-
-`$(wildcard PATTERN)'
- The argument PATTERN is a file name pattern, typically containing
- wildcard characters (as in shell file name patterns). The result
- of `wildcard' is a space-separated list of the names of existing
- files that match the pattern. *Note Using Wildcard Characters in
- File Names: Wildcards.
-
-`$(realpath NAMES...)'
- For each file name in NAMES return the canonical absolute name. A
- canonical name does not contain any `.' or `..' components, nor
- any repeated path separators (`/') or symlinks. In case of a
- failure the empty string is returned. Consult the `realpath(3)'
- documentation for a list of possible failure causes.
-
-`$(abspath NAMES...)'
- For each file name in NAMES return an absolute name that does not
- contain any `.' or `..' components, nor any repeated path
- separators (`/'). Note that, in contrast to `realpath' function,
- `abspath' does not resolve symlinks and does not require the file
- names to refer to an existing file or directory. Use the
- `wildcard' function to test for existence.
-
-
-File: make.info, Node: Conditional Functions, Next: Foreach Function, Prev: File Name Functions, Up: Functions
-
-8.4 Functions for Conditionals
-==============================
-
-There are three functions that provide conditional expansion. A key
-aspect of these functions is that not all of the arguments are expanded
-initially. Only those arguments which need to be expanded, will be
-expanded.
-
-`$(if CONDITION,THEN-PART[,ELSE-PART])'
- The `if' function provides support for conditional expansion in a
- functional context (as opposed to the GNU `make' makefile
- conditionals such as `ifeq' (*note Syntax of Conditionals:
- Conditional Syntax.).
-
- The first argument, CONDITION, first has all preceding and
- trailing whitespace stripped, then is expanded. If it expands to
- any non-empty string, then the condition is considered to be true.
- If it expands to an empty string, the condition is considered to
- be false.
-
- If the condition is true then the second argument, THEN-PART, is
- evaluated and this is used as the result of the evaluation of the
- entire `if' function.
-
- If the condition is false then the third argument, ELSE-PART, is
- evaluated and this is the result of the `if' function. If there is
- no third argument, the `if' function evaluates to nothing (the
- empty string).
-
- Note that only one of the THEN-PART or the ELSE-PART will be
- evaluated, never both. Thus, either can contain side-effects
- (such as `shell' function calls, etc.)
-
-`$(or CONDITION1[,CONDITION2[,CONDITION3...]])'
- The `or' function provides a "short-circuiting" OR operation.
- Each argument is expanded, in order. If an argument expands to a
- non-empty string the processing stops and the result of the
- expansion is that string. If, after all arguments are expanded,
- all of them are false (empty), then the result of the expansion is
- the empty string.
-
-`$(and CONDITION1[,CONDITION2[,CONDITION3...]])'
- The `and' function provides a "short-circuiting" AND operation.
- Each argument is expanded, in order. If an argument expands to an
- empty string the processing stops and the result of the expansion
- is the empty string. If all arguments expand to a non-empty
- string then the result of the expansion is the expansion of the
- last argument.
-
-
-
-File: make.info, Node: Foreach Function, Next: Call Function, Prev: Conditional Functions, Up: Functions
-
-8.5 The `foreach' Function
-==========================
-
-The `foreach' function is very different from other functions. It
-causes one piece of text to be used repeatedly, each time with a
-different substitution performed on it. It resembles the `for' command
-in the shell `sh' and the `foreach' command in the C-shell `csh'.
-
- The syntax of the `foreach' function is:
-
- $(foreach VAR,LIST,TEXT)
-
-The first two arguments, VAR and LIST, are expanded before anything
-else is done; note that the last argument, TEXT, is *not* expanded at
-the same time. Then for each word of the expanded value of LIST, the
-variable named by the expanded value of VAR is set to that word, and
-TEXT is expanded. Presumably TEXT contains references to that
-variable, so its expansion will be different each time.
-
- The result is that TEXT is expanded as many times as there are
-whitespace-separated words in LIST. The multiple expansions of TEXT
-are concatenated, with spaces between them, to make the result of
-`foreach'.
-
- This simple example sets the variable `files' to the list of all
-files in the directories in the list `dirs':
-
- dirs := a b c d
- files := $(foreach dir,$(dirs),$(wildcard $(dir)/*))
-
- Here TEXT is `$(wildcard $(dir)/*)'. The first repetition finds the
-value `a' for `dir', so it produces the same result as `$(wildcard
-a/*)'; the second repetition produces the result of `$(wildcard b/*)';
-and the third, that of `$(wildcard c/*)'.
-
- This example has the same result (except for setting `dirs') as the
-following example:
-
- files := $(wildcard a/* b/* c/* d/*)
-
- When TEXT is complicated, you can improve readability by giving it a
-name, with an additional variable:
-
- find_files = $(wildcard $(dir)/*)
- dirs := a b c d
- files := $(foreach dir,$(dirs),$(find_files))
-
-Here we use the variable `find_files' this way. We use plain `=' to
-define a recursively-expanding variable, so that its value contains an
-actual function call to be reexpanded under the control of `foreach'; a
-simply-expanded variable would not do, since `wildcard' would be called
-only once at the time of defining `find_files'.
-
- The `foreach' function has no permanent effect on the variable VAR;
-its value and flavor after the `foreach' function call are the same as
-they were beforehand. The other values which are taken from LIST are
-in effect only temporarily, during the execution of `foreach'. The
-variable VAR is a simply-expanded variable during the execution of
-`foreach'. If VAR was undefined before the `foreach' function call, it
-is undefined after the call. *Note The Two Flavors of Variables:
-Flavors.
-
- You must take care when using complex variable expressions that
-result in variable names because many strange things are valid variable
-names, but are probably not what you intended. For example,
-
- files := $(foreach Esta escrito en espanol!,b c ch,$(find_files))
-
-might be useful if the value of `find_files' references the variable
-whose name is `Esta escrito en espanol!' (es un nombre bastante largo,
-no?), but it is more likely to be a mistake.
-
-
-File: make.info, Node: Call Function, Next: Value Function, Prev: Foreach Function, Up: Functions
-
-8.6 The `call' Function
-=======================
-
-The `call' function is unique in that it can be used to create new
-parameterized functions. You can write a complex expression as the
-value of a variable, then use `call' to expand it with different values.
-
- The syntax of the `call' function is:
-
- $(call VARIABLE,PARAM,PARAM,...)
-
- When `make' expands this function, it assigns each PARAM to
-temporary variables `$(1)', `$(2)', etc. The variable `$(0)' will
-contain VARIABLE. There is no maximum number of parameter arguments.
-There is no minimum, either, but it doesn't make sense to use `call'
-with no parameters.
-
- Then VARIABLE is expanded as a `make' variable in the context of
-these temporary assignments. Thus, any reference to `$(1)' in the
-value of VARIABLE will resolve to the first PARAM in the invocation of
-`call'.
-
- Note that VARIABLE is the _name_ of a variable, not a _reference_ to
-that variable. Therefore you would not normally use a `$' or
-parentheses when writing it. (You can, however, use a variable
-reference in the name if you want the name not to be a constant.)
-
- If VARIABLE is the name of a builtin function, the builtin function
-is always invoked (even if a `make' variable by that name also exists).
-
- The `call' function expands the PARAM arguments before assigning
-them to temporary variables. This means that VARIABLE values
-containing references to builtin functions that have special expansion
-rules, like `foreach' or `if', may not work as you expect.
-
- Some examples may make this clearer.
-
- This macro simply reverses its arguments:
-
- reverse = $(2) $(1)
-
- foo = $(call reverse,a,b)
-
-Here FOO will contain `b a'.
-
- This one is slightly more interesting: it defines a macro to search
-for the first instance of a program in `PATH':
-
- pathsearch = $(firstword $(wildcard $(addsuffix /$(1),$(subst :, ,$(PATH)))))
-
- LS := $(call pathsearch,ls)
-
-Now the variable LS contains `/bin/ls' or similar.
-
- The `call' function can be nested. Each recursive invocation gets
-its own local values for `$(1)', etc. that mask the values of
-higher-level `call'. For example, here is an implementation of a "map"
-function:
-
- map = $(foreach a,$(2),$(call $(1),$(a)))
-
- Now you can MAP a function that normally takes only one argument,
-such as `origin', to multiple values in one step:
-
- o = $(call map,origin,o map MAKE)
-
- and end up with O containing something like `file file default'.
-
- A final caution: be careful when adding whitespace to the arguments
-to `call'. As with other functions, any whitespace contained in the
-second and subsequent arguments is kept; this can cause strange
-effects. It's generally safest to remove all extraneous whitespace when
-providing parameters to `call'.
-
-
-File: make.info, Node: Value Function, Next: Eval Function, Prev: Call Function, Up: Functions
-
-8.7 The `value' Function
-========================
-
-The `value' function provides a way for you to use the value of a
-variable _without_ having it expanded. Please note that this does not
-undo expansions which have already occurred; for example if you create
-a simply expanded variable its value is expanded during the definition;
-in that case the `value' function will return the same result as using
-the variable directly.
-
- The syntax of the `value' function is:
-
- $(value VARIABLE)
-
- Note that VARIABLE is the _name_ of a variable; not a _reference_ to
-that variable. Therefore you would not normally use a `$' or
-parentheses when writing it. (You can, however, use a variable
-reference in the name if you want the name not to be a constant.)
-
- The result of this function is a string containing the value of
-VARIABLE, without any expansion occurring. For example, in this
-makefile:
-
- FOO = $PATH
-
- all:
- @echo $(FOO)
- @echo $(value FOO)
-
-The first output line would be `ATH', since the "$P" would be expanded
-as a `make' variable, while the second output line would be the current
-value of your `$PATH' environment variable, since the `value' function
-avoided the expansion.
-
- The `value' function is most often used in conjunction with the
-`eval' function (*note Eval Function::).
-
-
-File: make.info, Node: Eval Function, Next: Origin Function, Prev: Value Function, Up: Functions
-
-8.8 The `eval' Function
-=======================
-
-The `eval' function is very special: it allows you to define new
-makefile constructs that are not constant; which are the result of
-evaluating other variables and functions. The argument to the `eval'
-function is expanded, then the results of that expansion are parsed as
-makefile syntax. The expanded results can define new `make' variables,
-targets, implicit or explicit rules, etc.
-
- The result of the `eval' function is always the empty string; thus,
-it can be placed virtually anywhere in a makefile without causing
-syntax errors.
-
- It's important to realize that the `eval' argument is expanded
-_twice_; first by the `eval' function, then the results of that
-expansion are expanded again when they are parsed as makefile syntax.
-This means you may need to provide extra levels of escaping for "$"
-characters when using `eval'. The `value' function (*note Value
-Function::) can sometimes be useful in these situations, to circumvent
-unwanted expansions.
-
- Here is an example of how `eval' can be used; this example combines
-a number of concepts and other functions. Although it might seem
-overly complex to use `eval' in this example, rather than just writing
-out the rules, consider two things: first, the template definition (in
-`PROGRAM_template') could need to be much more complex than it is here;
-and second, you might put the complex, "generic" part of this example
-into another makefile, then include it in all the individual makefiles.
-Now your individual makefiles are quite straightforward.
-
- PROGRAMS = server client
-
- server_OBJS = server.o server_priv.o server_access.o
- server_LIBS = priv protocol
-
- client_OBJS = client.o client_api.o client_mem.o
- client_LIBS = protocol
-
- # Everything after this is generic
-
- .PHONY: all
- all: $(PROGRAMS)
-
- define PROGRAM_template
- $(1): $$($(1)_OBJS) $$($(1)_LIBS:%=-l%)
- ALL_OBJS += $$($(1)_OBJS)
- endef
-
- $(foreach prog,$(PROGRAMS),$(eval $(call PROGRAM_template,$(prog))))
-
- $(PROGRAMS):
- $(LINK.o) $^ $(LDLIBS) -o $@
-
- clean:
- rm -f $(ALL_OBJS) $(PROGRAMS)
-
-
-File: make.info, Node: Origin Function, Next: Flavor Function, Prev: Eval Function, Up: Functions
-
-8.9 The `origin' Function
-=========================
-
-The `origin' function is unlike most other functions in that it does
-not operate on the values of variables; it tells you something _about_
-a variable. Specifically, it tells you where it came from.
-
- The syntax of the `origin' function is:
-
- $(origin VARIABLE)
-
- Note that VARIABLE is the _name_ of a variable to inquire about; not
-a _reference_ to that variable. Therefore you would not normally use a
-`$' or parentheses when writing it. (You can, however, use a variable
-reference in the name if you want the name not to be a constant.)
-
- The result of this function is a string telling you how the variable
-VARIABLE was defined:
-
-`undefined'
- if VARIABLE was never defined.
-
-`default'
- if VARIABLE has a default definition, as is usual with `CC' and so
- on. *Note Variables Used by Implicit Rules: Implicit Variables.
- Note that if you have redefined a default variable, the `origin'
- function will return the origin of the later definition.
-
-`environment'
- if VARIABLE was defined as an environment variable and the `-e'
- option is _not_ turned on (*note Summary of Options: Options
- Summary.).
-
-`environment override'
- if VARIABLE was defined as an environment variable and the `-e'
- option _is_ turned on (*note Summary of Options: Options Summary.).
-
-`file'
- if VARIABLE was defined in a makefile.
-
-`command line'
- if VARIABLE was defined on the command line.
-
-`override'
- if VARIABLE was defined with an `override' directive in a makefile
- (*note The `override' Directive: Override Directive.).
-
-`automatic'
- if VARIABLE is an automatic variable defined for the execution of
- the commands for each rule (*note Automatic Variables::).
-
- This information is primarily useful (other than for your curiosity)
-to determine if you want to believe the value of a variable. For
-example, suppose you have a makefile `foo' that includes another
-makefile `bar'. You want a variable `bletch' to be defined in `bar' if
-you run the command `make -f bar', even if the environment contains a
-definition of `bletch'. However, if `foo' defined `bletch' before
-including `bar', you do not want to override that definition. This
-could be done by using an `override' directive in `foo', giving that
-definition precedence over the later definition in `bar';
-unfortunately, the `override' directive would also override any command
-line definitions. So, `bar' could include:
-
- ifdef bletch
- ifeq "$(origin bletch)" "environment"
- bletch = barf, gag, etc.
- endif
- endif
-
-If `bletch' has been defined from the environment, this will redefine
-it.
-
- If you want to override a previous definition of `bletch' if it came
-from the environment, even under `-e', you could instead write:
-
- ifneq "$(findstring environment,$(origin bletch))" ""
- bletch = barf, gag, etc.
- endif
-
- Here the redefinition takes place if `$(origin bletch)' returns
-either `environment' or `environment override'. *Note Functions for
-String Substitution and Analysis: Text Functions.
-
-
-File: make.info, Node: Flavor Function, Next: Shell Function, Prev: Origin Function, Up: Functions
-
-8.10 The `flavor' Function
-==========================
-
-The `flavor' function is unlike most other functions (and like `origin'
-function) in that it does not operate on the values of variables; it
-tells you something _about_ a variable. Specifically, it tells you the
-flavor of a variable (*note The Two Flavors of Variables: Flavors.).
-
- The syntax of the `flavor' function is:
-
- $(flavor VARIABLE)
-
- Note that VARIABLE is the _name_ of a variable to inquire about; not
-a _reference_ to that variable. Therefore you would not normally use a
-`$' or parentheses when writing it. (You can, however, use a variable
-reference in the name if you want the name not to be a constant.)
-
- The result of this function is a string that identifies the flavor
-of the variable VARIABLE:
-
-`undefined'
- if VARIABLE was never defined.
-
-`recursive'
- if VARIABLE is a recursively expanded variable.
-
-`simple'
- if VARIABLE is a simply expanded variable.
-
-
-
-File: make.info, Node: Shell Function, Next: Make Control Functions, Prev: Flavor Function, Up: Functions
-
-8.11 The `shell' Function
-=========================
-
-The `shell' function is unlike any other function other than the
-`wildcard' function (*note The Function `wildcard': Wildcard Function.)
-in that it communicates with the world outside of `make'.
-
- The `shell' function performs the same function that backquotes
-(``') perform in most shells: it does "command expansion". This means
-that it takes as an argument a shell command and evaluates to the
-output of the command. The only processing `make' does on the result
-is to convert each newline (or carriage-return / newline pair) to a
-single space. If there is a trailing (carriage-return and) newline it
-will simply be removed.
-
- The commands run by calls to the `shell' function are run when the
-function calls are expanded (*note How `make' Reads a Makefile: Reading
-Makefiles.). Because this function involves spawning a new shell, you
-should carefully consider the performance implications of using the
-`shell' function within recursively expanded variables vs. simply
-expanded variables (*note The Two Flavors of Variables: Flavors.).
-
- Here are some examples of the use of the `shell' function:
-
- contents := $(shell cat foo)
-
-sets `contents' to the contents of the file `foo', with a space (rather
-than a newline) separating each line.
-
- files := $(shell echo *.c)
-
-sets `files' to the expansion of `*.c'. Unless `make' is using a very
-strange shell, this has the same result as `$(wildcard *.c)' (as long
-as at least one `.c' file exists).
-
-
-File: make.info, Node: Make Control Functions, Prev: Shell Function, Up: Functions
-
-8.12 Functions That Control Make
-================================
-
-These functions control the way make runs. Generally, they are used to
-provide information to the user of the makefile or to cause make to stop
-if some sort of environmental error is detected.
-
-`$(error TEXT...)'
- Generates a fatal error where the message is TEXT. Note that the
- error is generated whenever this function is evaluated. So, if
- you put it inside a command script or on the right side of a
- recursive variable assignment, it won't be evaluated until later.
- The TEXT will be expanded before the error is generated.
-
- For example,
-
- ifdef ERROR1
- $(error error is $(ERROR1))
- endif
-
- will generate a fatal error during the read of the makefile if the
- `make' variable `ERROR1' is defined. Or,
-
- ERR = $(error found an error!)
-
- .PHONY: err
- err: ; $(ERR)
-
- will generate a fatal error while `make' is running, if the `err'
- target is invoked.
-
-`$(warning TEXT...)'
- This function works similarly to the `error' function, above,
- except that `make' doesn't exit. Instead, TEXT is expanded and
- the resulting message is displayed, but processing of the makefile
- continues.
-
- The result of the expansion of this function is the empty string.
-
-`$(info TEXT...)'
- This function does nothing more than print its (expanded)
- argument(s) to standard output. No makefile name or line number
- is added. The result of the expansion of this function is the
- empty string.
-
-
-File: make.info, Node: Running, Next: Implicit Rules, Prev: Functions, Up: Top
-
-9 How to Run `make'
-*******************
-
-A makefile that says how to recompile a program can be used in more
-than one way. The simplest use is to recompile every file that is out
-of date. Usually, makefiles are written so that if you run `make' with
-no arguments, it does just that.
-
- But you might want to update only some of the files; you might want
-to use a different compiler or different compiler options; you might
-want just to find out which files are out of date without changing them.
-
- By giving arguments when you run `make', you can do any of these
-things and many others.
-
- The exit status of `make' is always one of three values:
-`0'
- The exit status is zero if `make' is successful.
-
-`2'
- The exit status is two if `make' encounters any errors. It will
- print messages describing the particular errors.
-
-`1'
- The exit status is one if you use the `-q' flag and `make'
- determines that some target is not already up to date. *Note
- Instead of Executing the Commands: Instead of Execution.
-
-* Menu:
-
-* Makefile Arguments:: How to specify which makefile to use.
-* Goals:: How to use goal arguments to specify which
- parts of the makefile to use.
-* Instead of Execution:: How to use mode flags to specify what
- kind of thing to do with the commands
- in the makefile other than simply
- execute them.
-* Avoiding Compilation:: How to avoid recompiling certain files.
-* Overriding:: How to override a variable to specify
- an alternate compiler and other things.
-* Testing:: How to proceed past some errors, to
- test compilation.
-* Options Summary:: Summary of Options
-
-
-File: make.info, Node: Makefile Arguments, Next: Goals, Prev: Running, Up: Running
-
-9.1 Arguments to Specify the Makefile
-=====================================
-
-The way to specify the name of the makefile is with the `-f' or
-`--file' option (`--makefile' also works). For example, `-f altmake'
-says to use the file `altmake' as the makefile.
-
- If you use the `-f' flag several times and follow each `-f' with an
-argument, all the specified files are used jointly as makefiles.
-
- If you do not use the `-f' or `--file' flag, the default is to try
-`GNUmakefile', `makefile', and `Makefile', in that order, and use the
-first of these three which exists or can be made (*note Writing
-Makefiles: Makefiles.).
-
-
-File: make.info, Node: Goals, Next: Instead of Execution, Prev: Makefile Arguments, Up: Running
-
-9.2 Arguments to Specify the Goals
-==================================
-
-The "goals" are the targets that `make' should strive ultimately to
-update. Other targets are updated as well if they appear as
-prerequisites of goals, or prerequisites of prerequisites of goals, etc.
-
- By default, the goal is the first target in the makefile (not
-counting targets that start with a period). Therefore, makefiles are
-usually written so that the first target is for compiling the entire
-program or programs they describe. If the first rule in the makefile
-has several targets, only the first target in the rule becomes the
-default goal, not the whole list. You can manage the selection of the
-default goal from within your makefile using the `.DEFAULT_GOAL'
-variable (*note Other Special Variables: Special Variables.).
-
- You can also specify a different goal or goals with command-line
-arguments to `make'. Use the name of the goal as an argument. If you
-specify several goals, `make' processes each of them in turn, in the
-order you name them.
-
- Any target in the makefile may be specified as a goal (unless it
-starts with `-' or contains an `=', in which case it will be parsed as
-a switch or variable definition, respectively). Even targets not in
-the makefile may be specified, if `make' can find implicit rules that
-say how to make them.
-
- `Make' will set the special variable `MAKECMDGOALS' to the list of
-goals you specified on the command line. If no goals were given on the
-command line, this variable is empty. Note that this variable should
-be used only in special circumstances.
-
- An example of appropriate use is to avoid including `.d' files
-during `clean' rules (*note Automatic Prerequisites::), so `make' won't
-create them only to immediately remove them again:
-
- sources = foo.c bar.c
-
- ifneq ($(MAKECMDGOALS),clean)
- include $(sources:.c=.d)
- endif
-
- One use of specifying a goal is if you want to compile only a part of
-the program, or only one of several programs. Specify as a goal each
-file that you wish to remake. For example, consider a directory
-containing several programs, with a makefile that starts like this:
-
- .PHONY: all
- all: size nm ld ar as
-
- If you are working on the program `size', you might want to say
-`make size' so that only the files of that program are recompiled.
-
- Another use of specifying a goal is to make files that are not
-normally made. For example, there may be a file of debugging output,
-or a version of the program that is compiled specially for testing,
-which has a rule in the makefile but is not a prerequisite of the
-default goal.
-
- Another use of specifying a goal is to run the commands associated
-with a phony target (*note Phony Targets::) or empty target (*note
-Empty Target Files to Record Events: Empty Targets.). Many makefiles
-contain a phony target named `clean' which deletes everything except
-source files. Naturally, this is done only if you request it
-explicitly with `make clean'. Following is a list of typical phony and
-empty target names. *Note Standard Targets::, for a detailed list of
-all the standard target names which GNU software packages use.
-
-`all'
- Make all the top-level targets the makefile knows about.
-
-`clean'
- Delete all files that are normally created by running `make'.
-
-`mostlyclean'
- Like `clean', but may refrain from deleting a few files that people
- normally don't want to recompile. For example, the `mostlyclean'
- target for GCC does not delete `libgcc.a', because recompiling it
- is rarely necessary and takes a lot of time.
-
-`distclean'
-`realclean'
-`clobber'
- Any of these targets might be defined to delete _more_ files than
- `clean' does. For example, this would delete configuration files
- or links that you would normally create as preparation for
- compilation, even if the makefile itself cannot create these files.
-
-`install'
- Copy the executable file into a directory that users typically
- search for commands; copy any auxiliary files that the executable
- uses into the directories where it will look for them.
-
-`print'
- Print listings of the source files that have changed.
-
-`tar'
- Create a tar file of the source files.
-
-`shar'
- Create a shell archive (shar file) of the source files.
-
-`dist'
- Create a distribution file of the source files. This might be a
- tar file, or a shar file, or a compressed version of one of the
- above, or even more than one of the above.
-
-`TAGS'
- Update a tags table for this program.
-
-`check'
-`test'
- Perform self tests on the program this makefile builds.
-
-
-File: make.info, Node: Instead of Execution, Next: Avoiding Compilation, Prev: Goals, Up: Running
-
-9.3 Instead of Executing the Commands
-=====================================
-
-The makefile tells `make' how to tell whether a target is up to date,
-and how to update each target. But updating the targets is not always
-what you want. Certain options specify other activities for `make'.
-
-`-n'
-`--just-print'
-`--dry-run'
-`--recon'
- "No-op". The activity is to print what commands would be used to
- make the targets up to date, but not actually execute them.
-
-`-t'
-`--touch'
- "Touch". The activity is to mark the targets as up to date without
- actually changing them. In other words, `make' pretends to compile
- the targets but does not really change their contents.
-
-`-q'
-`--question'
- "Question". The activity is to find out silently whether the
- targets are up to date already; but execute no commands in either
- case. In other words, neither compilation nor output will occur.
-
-`-W FILE'
-`--what-if=FILE'
-`--assume-new=FILE'
-`--new-file=FILE'
- "What if". Each `-W' flag is followed by a file name. The given
- files' modification times are recorded by `make' as being the
- present time, although the actual modification times remain the
- same. You can use the `-W' flag in conjunction with the `-n' flag
- to see what would happen if you were to modify specific files.
-
- With the `-n' flag, `make' prints the commands that it would
-normally execute but does not execute them.
-
- With the `-t' flag, `make' ignores the commands in the rules and
-uses (in effect) the command `touch' for each target that needs to be
-remade. The `touch' command is also printed, unless `-s' or `.SILENT'
-is used. For speed, `make' does not actually invoke the program
-`touch'. It does the work directly.
-
- With the `-q' flag, `make' prints nothing and executes no commands,
-but the exit status code it returns is zero if and only if the targets
-to be considered are already up to date. If the exit status is one,
-then some updating needs to be done. If `make' encounters an error,
-the exit status is two, so you can distinguish an error from a target
-that is not up to date.
-
- It is an error to use more than one of these three flags in the same
-invocation of `make'.
-
- The `-n', `-t', and `-q' options do not affect command lines that
-begin with `+' characters or contain the strings `$(MAKE)' or
-`${MAKE}'. Note that only the line containing the `+' character or the
-strings `$(MAKE)' or `${MAKE}' is run regardless of these options.
-Other lines in the same rule are not run unless they too begin with `+'
-or contain `$(MAKE)' or `${MAKE}' (*Note How the `MAKE' Variable Works:
-MAKE Variable.)
-
- The `-W' flag provides two features:
-
- * If you also use the `-n' or `-q' flag, you can see what `make'
- would do if you were to modify some files.
-
- * Without the `-n' or `-q' flag, when `make' is actually executing
- commands, the `-W' flag can direct `make' to act as if some files
- had been modified, without actually modifying the files.
-
- Note that the options `-p' and `-v' allow you to obtain other
-information about `make' or about the makefiles in use (*note Summary
-of Options: Options Summary.).
-
-
-File: make.info, Node: Avoiding Compilation, Next: Overriding, Prev: Instead of Execution, Up: Running
-
-9.4 Avoiding Recompilation of Some Files
-========================================
-
-Sometimes you may have changed a source file but you do not want to
-recompile all the files that depend on it. For example, suppose you add
-a macro or a declaration to a header file that many other files depend
-on. Being conservative, `make' assumes that any change in the header
-file requires recompilation of all dependent files, but you know that
-they do not need to be recompiled and you would rather not waste the
-time waiting for them to compile.
-
- If you anticipate the problem before changing the header file, you
-can use the `-t' flag. This flag tells `make' not to run the commands
-in the rules, but rather to mark the target up to date by changing its
-last-modification date. You would follow this procedure:
-
- 1. Use the command `make' to recompile the source files that really
- need recompilation, ensuring that the object files are up-to-date
- before you begin.
-
- 2. Make the changes in the header files.
-
- 3. Use the command `make -t' to mark all the object files as up to
- date. The next time you run `make', the changes in the header
- files will not cause any recompilation.
-
- If you have already changed the header file at a time when some files
-do need recompilation, it is too late to do this. Instead, you can use
-the `-o FILE' flag, which marks a specified file as "old" (*note
-Summary of Options: Options Summary.). This means that the file itself
-will not be remade, and nothing else will be remade on its account.
-Follow this procedure:
-
- 1. Recompile the source files that need compilation for reasons
- independent of the particular header file, with `make -o
- HEADERFILE'. If several header files are involved, use a separate
- `-o' option for each header file.
-
- 2. Touch all the object files with `make -t'.
-
-
-File: make.info, Node: Overriding, Next: Testing, Prev: Avoiding Compilation, Up: Running
-
-9.5 Overriding Variables
-========================
-
-An argument that contains `=' specifies the value of a variable: `V=X'
-sets the value of the variable V to X. If you specify a value in this
-way, all ordinary assignments of the same variable in the makefile are
-ignored; we say they have been "overridden" by the command line
-argument.
-
- The most common way to use this facility is to pass extra flags to
-compilers. For example, in a properly written makefile, the variable
-`CFLAGS' is included in each command that runs the C compiler, so a
-file `foo.c' would be compiled something like this:
-
- cc -c $(CFLAGS) foo.c
-
- Thus, whatever value you set for `CFLAGS' affects each compilation
-that occurs. The makefile probably specifies the usual value for
-`CFLAGS', like this:
-
- CFLAGS=-g
-
- Each time you run `make', you can override this value if you wish.
-For example, if you say `make CFLAGS='-g -O'', each C compilation will
-be done with `cc -c -g -O'. (This also illustrates how you can use
-quoting in the shell to enclose spaces and other special characters in
-the value of a variable when you override it.)
-
- The variable `CFLAGS' is only one of many standard variables that
-exist just so that you can change them this way. *Note Variables Used
-by Implicit Rules: Implicit Variables, for a complete list.
-
- You can also program the makefile to look at additional variables of
-your own, giving the user the ability to control other aspects of how
-the makefile works by changing the variables.
-
- When you override a variable with a command argument, you can define
-either a recursively-expanded variable or a simply-expanded variable.
-The examples shown above make a recursively-expanded variable; to make a
-simply-expanded variable, write `:=' instead of `='. But, unless you
-want to include a variable reference or function call in the _value_
-that you specify, it makes no difference which kind of variable you
-create.
-
- There is one way that the makefile can change a variable that you
-have overridden. This is to use the `override' directive, which is a
-line that looks like this: `override VARIABLE = VALUE' (*note The
-`override' Directive: Override Directive.).
-
-
-File: make.info, Node: Testing, Next: Options Summary, Prev: Overriding, Up: Running
-
-9.6 Testing the Compilation of a Program
-========================================
-
-Normally, when an error happens in executing a shell command, `make'
-gives up immediately, returning a nonzero status. No further commands
-are executed for any target. The error implies that the goal cannot be
-correctly remade, and `make' reports this as soon as it knows.
-
- When you are compiling a program that you have just changed, this is
-not what you want. Instead, you would rather that `make' try compiling
-every file that can be tried, to show you as many compilation errors as
-possible.
-
- On these occasions, you should use the `-k' or `--keep-going' flag.
-This tells `make' to continue to consider the other prerequisites of
-the pending targets, remaking them if necessary, before it gives up and
-returns nonzero status. For example, after an error in compiling one
-object file, `make -k' will continue compiling other object files even
-though it already knows that linking them will be impossible. In
-addition to continuing after failed shell commands, `make -k' will
-continue as much as possible after discovering that it does not know
-how to make a target or prerequisite file. This will always cause an
-error message, but without `-k', it is a fatal error (*note Summary of
-Options: Options Summary.).
-
- The usual behavior of `make' assumes that your purpose is to get the
-goals up to date; once `make' learns that this is impossible, it might
-as well report the failure immediately. The `-k' flag says that the
-real purpose is to test as much as possible of the changes made in the
-program, perhaps to find several independent problems so that you can
-correct them all before the next attempt to compile. This is why Emacs'
-`M-x compile' command passes the `-k' flag by default.
-
-
-File: make.info, Node: Options Summary, Prev: Testing, Up: Running
-
-9.7 Summary of Options
-======================
-
-Here is a table of all the options `make' understands:
-
-`-b'
-`-m'
- These options are ignored for compatibility with other versions of
- `make'.
-
-`-B'
-`--always-make'
- Consider all targets out-of-date. GNU `make' proceeds to consider
- targets and their prerequisites using the normal algorithms;
- however, all targets so considered are always remade regardless of
- the status of their prerequisites. To avoid infinite recursion, if
- `MAKE_RESTARTS' (*note Other Special Variables: Special
- Variables.) is set to a number greater than 0 this option is
- disabled when considering whether to remake makefiles (*note How
- Makefiles Are Remade: Remaking Makefiles.).
-
-`-C DIR'
-`--directory=DIR'
- Change to directory DIR before reading the makefiles. If multiple
- `-C' options are specified, each is interpreted relative to the
- previous one: `-C / -C etc' is equivalent to `-C /etc'. This is
- typically used with recursive invocations of `make' (*note
- Recursive Use of `make': Recursion.).
-
-`-d'
- Print debugging information in addition to normal processing. The
- debugging information says which files are being considered for
- remaking, which file-times are being compared and with what
- results, which files actually need to be remade, which implicit
- rules are considered and which are applied--everything interesting
- about how `make' decides what to do. The `-d' option is
- equivalent to `--debug=a' (see below).
-
-`--debug[=OPTIONS]'
- Print debugging information in addition to normal processing.
- Various levels and types of output can be chosen. With no
- arguments, print the "basic" level of debugging. Possible
- arguments are below; only the first character is considered, and
- values must be comma- or space-separated.
-
- `a (all)'
- All types of debugging output are enabled. This is
- equivalent to using `-d'.
-
- `b (basic)'
- Basic debugging prints each target that was found to be
- out-of-date, and whether the build was successful or not.
-
- `v (verbose)'
- A level above `basic'; includes messages about which
- makefiles were parsed, prerequisites that did not need to be
- rebuilt, etc. This option also enables `basic' messages.
-
- `i (implicit)'
- Prints messages describing the implicit rule searches for
- each target. This option also enables `basic' messages.
-
- `j (jobs)'
- Prints messages giving details on the invocation of specific
- subcommands.
-
- `m (makefile)'
- By default, the above messages are not enabled while trying
- to remake the makefiles. This option enables messages while
- rebuilding makefiles, too. Note that the `all' option does
- enable this option. This option also enables `basic'
- messages.
-
-`-e'
-`--environment-overrides'
- Give variables taken from the environment precedence over
- variables from makefiles. *Note Variables from the Environment:
- Environment.
-
-`-f FILE'
-`--file=FILE'
-`--makefile=FILE'
- Read the file named FILE as a makefile. *Note Writing Makefiles:
- Makefiles.
-
-`-h'
-`--help'
- Remind you of the options that `make' understands and then exit.
-
-`-i'
-`--ignore-errors'
- Ignore all errors in commands executed to remake files. *Note
- Errors in Commands: Errors.
-
-`-I DIR'
-`--include-dir=DIR'
- Specifies a directory DIR to search for included makefiles. *Note
- Including Other Makefiles: Include. If several `-I' options are
- used to specify several directories, the directories are searched
- in the order specified.
-
-`-j [JOBS]'
-`--jobs[=JOBS]'
- Specifies the number of jobs (commands) to run simultaneously.
- With no argument, `make' runs as many jobs simultaneously as
- possible. If there is more than one `-j' option, the last one is
- effective. *Note Parallel Execution: Parallel, for more
- information on how commands are run. Note that this option is
- ignored on MS-DOS.
-
-`-k'
-`--keep-going'
- Continue as much as possible after an error. While the target that
- failed, and those that depend on it, cannot be remade, the other
- prerequisites of these targets can be processed all the same.
- *Note Testing the Compilation of a Program: Testing.
-
-`-l [LOAD]'
-`--load-average[=LOAD]'
-`--max-load[=LOAD]'
- Specifies that no new jobs (commands) should be started if there
- are other jobs running and the load average is at least LOAD (a
- floating-point number). With no argument, removes a previous load
- limit. *Note Parallel Execution: Parallel.
-
-`-L'
-`--check-symlink-times'
- On systems that support symbolic links, this option causes `make'
- to consider the timestamps on any symbolic links in addition to the
- timestamp on the file referenced by those links. When this option
- is provided, the most recent timestamp among the file and the
- symbolic links is taken as the modification time for this target
- file.
-
-`-n'
-`--just-print'
-`--dry-run'
-`--recon'
- Print the commands that would be executed, but do not execute them.
- *Note Instead of Executing the Commands: Instead of Execution.
-
-`-o FILE'
-`--old-file=FILE'
-`--assume-old=FILE'
- Do not remake the file FILE even if it is older than its
- prerequisites, and do not remake anything on account of changes in
- FILE. Essentially the file is treated as very old and its rules
- are ignored. *Note Avoiding Recompilation of Some Files: Avoiding
- Compilation.
-
-`-p'
-`--print-data-base'
- Print the data base (rules and variable values) that results from
- reading the makefiles; then execute as usual or as otherwise
- specified. This also prints the version information given by the
- `-v' switch (see below). To print the data base without trying to
- remake any files, use `make -qp'. To print the data base of
- predefined rules and variables, use `make -p -f /dev/null'. The
- data base output contains filename and linenumber information for
- command and variable definitions, so it can be a useful debugging
- tool in complex environments.
-
-`-q'
-`--question'
- "Question mode". Do not run any commands, or print anything; just
- return an exit status that is zero if the specified targets are
- already up to date, one if any remaking is required, or two if an
- error is encountered. *Note Instead of Executing the Commands:
- Instead of Execution.
-
-`-r'
-`--no-builtin-rules'
- Eliminate use of the built-in implicit rules (*note Using Implicit
- Rules: Implicit Rules.). You can still define your own by writing
- pattern rules (*note Defining and Redefining Pattern Rules:
- Pattern Rules.). The `-r' option also clears out the default list
- of suffixes for suffix rules (*note Old-Fashioned Suffix Rules:
- Suffix Rules.). But you can still define your own suffixes with a
- rule for `.SUFFIXES', and then define your own suffix rules. Note
- that only _rules_ are affected by the `-r' option; default
- variables remain in effect (*note Variables Used by Implicit
- Rules: Implicit Variables.); see the `-R' option below.
-
-`-R'
-`--no-builtin-variables'
- Eliminate use of the built-in rule-specific variables (*note
- Variables Used by Implicit Rules: Implicit Variables.). You can
- still define your own, of course. The `-R' option also
- automatically enables the `-r' option (see above), since it
- doesn't make sense to have implicit rules without any definitions
- for the variables that they use.
-
-`-s'
-`--silent'
-`--quiet'
- Silent operation; do not print the commands as they are executed.
- *Note Command Echoing: Echoing.
-
-`-S'
-`--no-keep-going'
-`--stop'
- Cancel the effect of the `-k' option. This is never necessary
- except in a recursive `make' where `-k' might be inherited from
- the top-level `make' via `MAKEFLAGS' (*note Recursive Use of
- `make': Recursion.) or if you set `-k' in `MAKEFLAGS' in your
- environment.
-
-`-t'
-`--touch'
- Touch files (mark them up to date without really changing them)
- instead of running their commands. This is used to pretend that
- the commands were done, in order to fool future invocations of
- `make'. *Note Instead of Executing the Commands: Instead of
- Execution.
-
-`-v'
-`--version'
- Print the version of the `make' program plus a copyright, a list
- of authors, and a notice that there is no warranty; then exit.
-
-`-w'
-`--print-directory'
- Print a message containing the working directory both before and
- after executing the makefile. This may be useful for tracking
- down errors from complicated nests of recursive `make' commands.
- *Note Recursive Use of `make': Recursion. (In practice, you
- rarely need to specify this option since `make' does it for you;
- see *Note The `--print-directory' Option: -w Option.)
-
-`--no-print-directory'
- Disable printing of the working directory under `-w'. This option
- is useful when `-w' is turned on automatically, but you do not
- want to see the extra messages. *Note The `--print-directory'
- Option: -w Option.
-
-`-W FILE'
-`--what-if=FILE'
-`--new-file=FILE'
-`--assume-new=FILE'
- Pretend that the target FILE has just been modified. When used
- with the `-n' flag, this shows you what would happen if you were
- to modify that file. Without `-n', it is almost the same as
- running a `touch' command on the given file before running `make',
- except that the modification time is changed only in the
- imagination of `make'. *Note Instead of Executing the Commands:
- Instead of Execution.
-
-`--warn-undefined-variables'
- Issue a warning message whenever `make' sees a reference to an
- undefined variable. This can be helpful when you are trying to
- debug makefiles which use variables in complex ways.
-
-
-File: make.info, Node: Implicit Rules, Next: Archives, Prev: Running, Up: Top
-
-10 Using Implicit Rules
-***********************
-
-Certain standard ways of remaking target files are used very often. For
-example, one customary way to make an object file is from a C source
-file using the C compiler, `cc'.
-
- "Implicit rules" tell `make' how to use customary techniques so that
-you do not have to specify them in detail when you want to use them.
-For example, there is an implicit rule for C compilation. File names
-determine which implicit rules are run. For example, C compilation
-typically takes a `.c' file and makes a `.o' file. So `make' applies
-the implicit rule for C compilation when it sees this combination of
-file name endings.
-
- A chain of implicit rules can apply in sequence; for example, `make'
-will remake a `.o' file from a `.y' file by way of a `.c' file.
-
- The built-in implicit rules use several variables in their commands
-so that, by changing the values of the variables, you can change the
-way the implicit rule works. For example, the variable `CFLAGS'
-controls the flags given to the C compiler by the implicit rule for C
-compilation.
-
- You can define your own implicit rules by writing "pattern rules".
-
- "Suffix rules" are a more limited way to define implicit rules.
-Pattern rules are more general and clearer, but suffix rules are
-retained for compatibility.
-
-* Menu:
-
-* Using Implicit:: How to use an existing implicit rule
- to get the commands for updating a file.
-* Catalogue of Rules:: A list of built-in implicit rules.
-* Implicit Variables:: How to change what predefined rules do.
-* Chained Rules:: How to use a chain of implicit rules.
-* Pattern Rules:: How to define new implicit rules.
-* Last Resort:: How to define commands for rules which
- cannot find any.
-* Suffix Rules:: The old-fashioned style of implicit rule.
-* Implicit Rule Search:: The precise algorithm for applying
- implicit rules.
-
-
-File: make.info, Node: Using Implicit, Next: Catalogue of Rules, Prev: Implicit Rules, Up: Implicit Rules
-
-10.1 Using Implicit Rules
-=========================
-
-To allow `make' to find a customary method for updating a target file,
-all you have to do is refrain from specifying commands yourself. Either
-write a rule with no command lines, or don't write a rule at all. Then
-`make' will figure out which implicit rule to use based on which kind
-of source file exists or can be made.
-
- For example, suppose the makefile looks like this:
-
- foo : foo.o bar.o
- cc -o foo foo.o bar.o $(CFLAGS) $(LDFLAGS)
-
-Because you mention `foo.o' but do not give a rule for it, `make' will
-automatically look for an implicit rule that tells how to update it.
-This happens whether or not the file `foo.o' currently exists.
-
- If an implicit rule is found, it can supply both commands and one or
-more prerequisites (the source files). You would want to write a rule
-for `foo.o' with no command lines if you need to specify additional
-prerequisites, such as header files, that the implicit rule cannot
-supply.
-
- Each implicit rule has a target pattern and prerequisite patterns.
-There may be many implicit rules with the same target pattern. For
-example, numerous rules make `.o' files: one, from a `.c' file with the
-C compiler; another, from a `.p' file with the Pascal compiler; and so
-on. The rule that actually applies is the one whose prerequisites
-exist or can be made. So, if you have a file `foo.c', `make' will run
-the C compiler; otherwise, if you have a file `foo.p', `make' will run
-the Pascal compiler; and so on.
-
- Of course, when you write the makefile, you know which implicit rule
-you want `make' to use, and you know it will choose that one because you
-know which possible prerequisite files are supposed to exist. *Note
-Catalogue of Implicit Rules: Catalogue of Rules, for a catalogue of all
-the predefined implicit rules.
-
- Above, we said an implicit rule applies if the required
-prerequisites "exist or can be made". A file "can be made" if it is
-mentioned explicitly in the makefile as a target or a prerequisite, or
-if an implicit rule can be recursively found for how to make it. When
-an implicit prerequisite is the result of another implicit rule, we say
-that "chaining" is occurring. *Note Chains of Implicit Rules: Chained
-Rules.
-
- In general, `make' searches for an implicit rule for each target, and
-for each double-colon rule, that has no commands. A file that is
-mentioned only as a prerequisite is considered a target whose rule
-specifies nothing, so implicit rule search happens for it. *Note
-Implicit Rule Search Algorithm: Implicit Rule Search, for the details
-of how the search is done.
-
- Note that explicit prerequisites do not influence implicit rule
-search. For example, consider this explicit rule:
-
- foo.o: foo.p
-
-The prerequisite on `foo.p' does not necessarily mean that `make' will
-remake `foo.o' according to the implicit rule to make an object file, a
-`.o' file, from a Pascal source file, a `.p' file. For example, if
-`foo.c' also exists, the implicit rule to make an object file from a C
-source file is used instead, because it appears before the Pascal rule
-in the list of predefined implicit rules (*note Catalogue of Implicit
-Rules: Catalogue of Rules.).
-
- If you do not want an implicit rule to be used for a target that has
-no commands, you can give that target empty commands by writing a
-semicolon (*note Defining Empty Commands: Empty Commands.).
-
-
-File: make.info, Node: Catalogue of Rules, Next: Implicit Variables, Prev: Using Implicit, Up: Implicit Rules
-
-10.2 Catalogue of Implicit Rules
-================================
-
-Here is a catalogue of predefined implicit rules which are always
-available unless the makefile explicitly overrides or cancels them.
-*Note Canceling Implicit Rules: Canceling Rules, for information on
-canceling or overriding an implicit rule. The `-r' or
-`--no-builtin-rules' option cancels all predefined rules.
-
- This manual only documents the default rules available on POSIX-based
-operating systems. Other operating systems, such as VMS, Windows,
-OS/2, etc. may have different sets of default rules. To see the full
-list of default rules and variables available in your version of GNU
-`make', run `make -p' in a directory with no makefile.
-
- Not all of these rules will always be defined, even when the `-r'
-option is not given. Many of the predefined implicit rules are
-implemented in `make' as suffix rules, so which ones will be defined
-depends on the "suffix list" (the list of prerequisites of the special
-target `.SUFFIXES'). The default suffix list is: `.out', `.a', `.ln',
-`.o', `.c', `.cc', `.C', `.cpp', `.p', `.f', `.F', `.r', `.y', `.l',
-`.s', `.S', `.mod', `.sym', `.def', `.h', `.info', `.dvi', `.tex',
-`.texinfo', `.texi', `.txinfo', `.w', `.ch' `.web', `.sh', `.elc',
-`.el'. All of the implicit rules described below whose prerequisites
-have one of these suffixes are actually suffix rules. If you modify
-the suffix list, the only predefined suffix rules in effect will be
-those named by one or two of the suffixes that are on the list you
-specify; rules whose suffixes fail to be on the list are disabled.
-*Note Old-Fashioned Suffix Rules: Suffix Rules, for full details on
-suffix rules.
-
-Compiling C programs
- `N.o' is made automatically from `N.c' with a command of the form
- `$(CC) -c $(CPPFLAGS) $(CFLAGS)'.
-
-Compiling C++ programs
- `N.o' is made automatically from `N.cc', `N.cpp', or `N.C' with a
- command of the form `$(CXX) -c $(CPPFLAGS) $(CXXFLAGS)'. We
- encourage you to use the suffix `.cc' for C++ source files instead
- of `.C'.
-
-Compiling Pascal programs
- `N.o' is made automatically from `N.p' with the command `$(PC) -c
- $(PFLAGS)'.
-
-Compiling Fortran and Ratfor programs
- `N.o' is made automatically from `N.r', `N.F' or `N.f' by running
- the Fortran compiler. The precise command used is as follows:
-
- `.f'
- `$(FC) -c $(FFLAGS)'.
-
- `.F'
- `$(FC) -c $(FFLAGS) $(CPPFLAGS)'.
-
- `.r'
- `$(FC) -c $(FFLAGS) $(RFLAGS)'.
-
-Preprocessing Fortran and Ratfor programs
- `N.f' is made automatically from `N.r' or `N.F'. This rule runs
- just the preprocessor to convert a Ratfor or preprocessable
- Fortran program into a strict Fortran program. The precise
- command used is as follows:
-
- `.F'
- `$(FC) -F $(CPPFLAGS) $(FFLAGS)'.
-
- `.r'
- `$(FC) -F $(FFLAGS) $(RFLAGS)'.
-
-Compiling Modula-2 programs
- `N.sym' is made from `N.def' with a command of the form `$(M2C)
- $(M2FLAGS) $(DEFFLAGS)'. `N.o' is made from `N.mod'; the form is:
- `$(M2C) $(M2FLAGS) $(MODFLAGS)'.
-
-Assembling and preprocessing assembler programs
- `N.o' is made automatically from `N.s' by running the assembler,
- `as'. The precise command is `$(AS) $(ASFLAGS)'.
-
- `N.s' is made automatically from `N.S' by running the C
- preprocessor, `cpp'. The precise command is `$(CPP) $(CPPFLAGS)'.
-
-Linking a single object file
- `N' is made automatically from `N.o' by running the linker
- (usually called `ld') via the C compiler. The precise command
- used is `$(CC) $(LDFLAGS) N.o $(LOADLIBES) $(LDLIBS)'.
-
- This rule does the right thing for a simple program with only one
- source file. It will also do the right thing if there are multiple
- object files (presumably coming from various other source files),
- one of which has a name matching that of the executable file.
- Thus,
-
- x: y.o z.o
-
- when `x.c', `y.c' and `z.c' all exist will execute:
-
- cc -c x.c -o x.o
- cc -c y.c -o y.o
- cc -c z.c -o z.o
- cc x.o y.o z.o -o x
- rm -f x.o
- rm -f y.o
- rm -f z.o
-
- In more complicated cases, such as when there is no object file
- whose name derives from the executable file name, you must write
- an explicit command for linking.
-
- Each kind of file automatically made into `.o' object files will
- be automatically linked by using the compiler (`$(CC)', `$(FC)' or
- `$(PC)'; the C compiler `$(CC)' is used to assemble `.s' files)
- without the `-c' option. This could be done by using the `.o'
- object files as intermediates, but it is faster to do the
- compiling and linking in one step, so that's how it's done.
-
-Yacc for C programs
- `N.c' is made automatically from `N.y' by running Yacc with the
- command `$(YACC) $(YFLAGS)'.
-
-Lex for C programs
- `N.c' is made automatically from `N.l' by running Lex. The actual
- command is `$(LEX) $(LFLAGS)'.
-
-Lex for Ratfor programs
- `N.r' is made automatically from `N.l' by running Lex. The actual
- command is `$(LEX) $(LFLAGS)'.
-
- The convention of using the same suffix `.l' for all Lex files
- regardless of whether they produce C code or Ratfor code makes it
- impossible for `make' to determine automatically which of the two
- languages you are using in any particular case. If `make' is
- called upon to remake an object file from a `.l' file, it must
- guess which compiler to use. It will guess the C compiler, because
- that is more common. If you are using Ratfor, make sure `make'
- knows this by mentioning `N.r' in the makefile. Or, if you are
- using Ratfor exclusively, with no C files, remove `.c' from the
- list of implicit rule suffixes with:
-
- .SUFFIXES:
- .SUFFIXES: .o .r .f .l ...
-
-Making Lint Libraries from C, Yacc, or Lex programs
- `N.ln' is made from `N.c' by running `lint'. The precise command
- is `$(LINT) $(LINTFLAGS) $(CPPFLAGS) -i'. The same command is
- used on the C code produced from `N.y' or `N.l'.
-
-TeX and Web
- `N.dvi' is made from `N.tex' with the command `$(TEX)'. `N.tex'
- is made from `N.web' with `$(WEAVE)', or from `N.w' (and from
- `N.ch' if it exists or can be made) with `$(CWEAVE)'. `N.p' is
- made from `N.web' with `$(TANGLE)' and `N.c' is made from `N.w'
- (and from `N.ch' if it exists or can be made) with `$(CTANGLE)'.
-
-Texinfo and Info
- `N.dvi' is made from `N.texinfo', `N.texi', or `N.txinfo', with
- the command `$(TEXI2DVI) $(TEXI2DVI_FLAGS)'. `N.info' is made from
- `N.texinfo', `N.texi', or `N.txinfo', with the command
- `$(MAKEINFO) $(MAKEINFO_FLAGS)'.
-
-RCS
- Any file `N' is extracted if necessary from an RCS file named
- either `N,v' or `RCS/N,v'. The precise command used is
- `$(CO) $(COFLAGS)'. `N' will not be extracted from RCS if it
- already exists, even if the RCS file is newer. The rules for RCS
- are terminal (*note Match-Anything Pattern Rules: Match-Anything
- Rules.), so RCS files cannot be generated from another source;
- they must actually exist.
-
-SCCS
- Any file `N' is extracted if necessary from an SCCS file named
- either `s.N' or `SCCS/s.N'. The precise command used is
- `$(GET) $(GFLAGS)'. The rules for SCCS are terminal (*note
- Match-Anything Pattern Rules: Match-Anything Rules.), so SCCS
- files cannot be generated from another source; they must actually
- exist.
-
- For the benefit of SCCS, a file `N' is copied from `N.sh' and made
- executable (by everyone). This is for shell scripts that are
- checked into SCCS. Since RCS preserves the execution permission
- of a file, you do not need to use this feature with RCS.
-
- We recommend that you avoid using of SCCS. RCS is widely held to
- be superior, and is also free. By choosing free software in place
- of comparable (or inferior) proprietary software, you support the
- free software movement.
-
- Usually, you want to change only the variables listed in the table
-above, which are documented in the following section.
-
- However, the commands in built-in implicit rules actually use
-variables such as `COMPILE.c', `LINK.p', and `PREPROCESS.S', whose
-values contain the commands listed above.
-
- `make' follows the convention that the rule to compile a `.X' source
-file uses the variable `COMPILE.X'. Similarly, the rule to produce an
-executable from a `.X' file uses `LINK.X'; and the rule to preprocess a
-`.X' file uses `PREPROCESS.X'.
-
- Every rule that produces an object file uses the variable
-`OUTPUT_OPTION'. `make' defines this variable either to contain `-o
-$@', or to be empty, depending on a compile-time option. You need the
-`-o' option to ensure that the output goes into the right file when the
-source file is in a different directory, as when using `VPATH' (*note
-Directory Search::). However, compilers on some systems do not accept
-a `-o' switch for object files. If you use such a system, and use
-`VPATH', some compilations will put their output in the wrong place. A
-possible workaround for this problem is to give `OUTPUT_OPTION' the
-value `; mv $*.o $@'.
-
-
-File: make.info, Node: Implicit Variables, Next: Chained Rules, Prev: Catalogue of Rules, Up: Implicit Rules
-
-10.3 Variables Used by Implicit Rules
-=====================================
-
-The commands in built-in implicit rules make liberal use of certain
-predefined variables. You can alter the values of these variables in
-the makefile, with arguments to `make', or in the environment to alter
-how the implicit rules work without redefining the rules themselves.
-You can cancel all variables used by implicit rules with the `-R' or
-`--no-builtin-variables' option.
-
- For example, the command used to compile a C source file actually
-says `$(CC) -c $(CFLAGS) $(CPPFLAGS)'. The default values of the
-variables used are `cc' and nothing, resulting in the command `cc -c'.
-By redefining `CC' to `ncc', you could cause `ncc' to be used for all C
-compilations performed by the implicit rule. By redefining `CFLAGS' to
-be `-g', you could pass the `-g' option to each compilation. _All_
-implicit rules that do C compilation use `$(CC)' to get the program
-name for the compiler and _all_ include `$(CFLAGS)' among the arguments
-given to the compiler.
-
- The variables used in implicit rules fall into two classes: those
-that are names of programs (like `CC') and those that contain arguments
-for the programs (like `CFLAGS'). (The "name of a program" may also
-contain some command arguments, but it must start with an actual
-executable program name.) If a variable value contains more than one
-argument, separate them with spaces.
-
- The following tables describe of some of the more commonly-used
-predefined variables. This list is not exhaustive, and the default
-values shown here may not be what are selected by `make' for your
-environment. To see the complete list of predefined variables for your
-instance of GNU `make' you can run `make -p' in a directory with no
-makefiles.
-
- Here is a table of some of the more common variables used as names of
-programs in built-in rules: makefiles.
-
-`AR'
- Archive-maintaining program; default `ar'.
-
-`AS'
- Program for compiling assembly files; default `as'.
-
-`CC'
- Program for compiling C programs; default `cc'.
-
-`CO'
- Program for checking out files from RCS; default `co'.
-
-`CXX'
- Program for compiling C++ programs; default `g++'.
-
-`CO'
- Program for extracting a file from RCS; default `co'.
-
-`CPP'
- Program for running the C preprocessor, with results to standard
- output; default `$(CC) -E'.
-
-`FC'
- Program for compiling or preprocessing Fortran and Ratfor programs;
- default `f77'.
-
-`GET'
- Program for extracting a file from SCCS; default `get'.
-
-`LEX'
- Program to use to turn Lex grammars into source code; default
- `lex'.
-
-`YACC'
- Program to use to turn Yacc grammars into source code; default
- `yacc'.
-
-`LINT'
- Program to use to run lint on source code; default `lint'.
-
-`M2C'
- Program to use to compile Modula-2 source code; default `m2c'.
-
-`PC'
- Program for compiling Pascal programs; default `pc'.
-
-`MAKEINFO'
- Program to convert a Texinfo source file into an Info file; default
- `makeinfo'.
-
-`TEX'
- Program to make TeX DVI files from TeX source; default `tex'.
-
-`TEXI2DVI'
- Program to make TeX DVI files from Texinfo source; default
- `texi2dvi'.
-
-`WEAVE'
- Program to translate Web into TeX; default `weave'.
-
-`CWEAVE'
- Program to translate C Web into TeX; default `cweave'.
-
-`TANGLE'
- Program to translate Web into Pascal; default `tangle'.
-
-`CTANGLE'
- Program to translate C Web into C; default `ctangle'.
-
-`RM'
- Command to remove a file; default `rm -f'.
-
- Here is a table of variables whose values are additional arguments
-for the programs above. The default values for all of these is the
-empty string, unless otherwise noted.
-
-`ARFLAGS'
- Flags to give the archive-maintaining program; default `rv'.
-
-`ASFLAGS'
- Extra flags to give to the assembler (when explicitly invoked on a
- `.s' or `.S' file).
-
-`CFLAGS'
- Extra flags to give to the C compiler.
-
-`CXXFLAGS'
- Extra flags to give to the C++ compiler.
-
-`COFLAGS'
- Extra flags to give to the RCS `co' program.
-
-`CPPFLAGS'
- Extra flags to give to the C preprocessor and programs that use it
- (the C and Fortran compilers).
-
-`FFLAGS'
- Extra flags to give to the Fortran compiler.
-
-`GFLAGS'
- Extra flags to give to the SCCS `get' program.
-
-`LDFLAGS'
- Extra flags to give to compilers when they are supposed to invoke
- the linker, `ld'.
-
-`LFLAGS'
- Extra flags to give to Lex.
-
-`YFLAGS'
- Extra flags to give to Yacc.
-
-`PFLAGS'
- Extra flags to give to the Pascal compiler.
-
-`RFLAGS'
- Extra flags to give to the Fortran compiler for Ratfor programs.
-
-`LINTFLAGS'
- Extra flags to give to lint.
-
-
-File: make.info, Node: Chained Rules, Next: Pattern Rules, Prev: Implicit Variables, Up: Implicit Rules
-
-10.4 Chains of Implicit Rules
-=============================
-
-Sometimes a file can be made by a sequence of implicit rules. For
-example, a file `N.o' could be made from `N.y' by running first Yacc
-and then `cc'. Such a sequence is called a "chain".
-
- If the file `N.c' exists, or is mentioned in the makefile, no
-special searching is required: `make' finds that the object file can be
-made by C compilation from `N.c'; later on, when considering how to
-make `N.c', the rule for running Yacc is used. Ultimately both `N.c'
-and `N.o' are updated.
-
- However, even if `N.c' does not exist and is not mentioned, `make'
-knows how to envision it as the missing link between `N.o' and `N.y'!
-In this case, `N.c' is called an "intermediate file". Once `make' has
-decided to use the intermediate file, it is entered in the data base as
-if it had been mentioned in the makefile, along with the implicit rule
-that says how to create it.
-
- Intermediate files are remade using their rules just like all other
-files. But intermediate files are treated differently in two ways.
-
- The first difference is what happens if the intermediate file does
-not exist. If an ordinary file B does not exist, and `make' considers
-a target that depends on B, it invariably creates B and then updates
-the target from B. But if B is an intermediate file, then `make' can
-leave well enough alone. It won't bother updating B, or the ultimate
-target, unless some prerequisite of B is newer than that target or
-there is some other reason to update that target.
-
- The second difference is that if `make' _does_ create B in order to
-update something else, it deletes B later on after it is no longer
-needed. Therefore, an intermediate file which did not exist before
-`make' also does not exist after `make'. `make' reports the deletion
-to you by printing a `rm -f' command showing which file it is deleting.
-
- Ordinarily, a file cannot be intermediate if it is mentioned in the
-makefile as a target or prerequisite. However, you can explicitly mark
-a file as intermediate by listing it as a prerequisite of the special
-target `.INTERMEDIATE'. This takes effect even if the file is mentioned
-explicitly in some other way.
-
- You can prevent automatic deletion of an intermediate file by
-marking it as a "secondary" file. To do this, list it as a
-prerequisite of the special target `.SECONDARY'. When a file is
-secondary, `make' will not create the file merely because it does not
-already exist, but `make' does not automatically delete the file.
-Marking a file as secondary also marks it as intermediate.
-
- You can list the target pattern of an implicit rule (such as `%.o')
-as a prerequisite of the special target `.PRECIOUS' to preserve
-intermediate files made by implicit rules whose target patterns match
-that file's name; see *Note Interrupts::.
-
- A chain can involve more than two implicit rules. For example, it is
-possible to make a file `foo' from `RCS/foo.y,v' by running RCS, Yacc
-and `cc'. Then both `foo.y' and `foo.c' are intermediate files that
-are deleted at the end.
-
- No single implicit rule can appear more than once in a chain. This
-means that `make' will not even consider such a ridiculous thing as
-making `foo' from `foo.o.o' by running the linker twice. This
-constraint has the added benefit of preventing any infinite loop in the
-search for an implicit rule chain.
-
- There are some special implicit rules to optimize certain cases that
-would otherwise be handled by rule chains. For example, making `foo'
-from `foo.c' could be handled by compiling and linking with separate
-chained rules, using `foo.o' as an intermediate file. But what
-actually happens is that a special rule for this case does the
-compilation and linking with a single `cc' command. The optimized rule
-is used in preference to the step-by-step chain because it comes
-earlier in the ordering of rules.
-
diff -rNU3 dist.orig/doc/make.info-2 dist/doc/make.info-2
--- dist.orig/doc/make.info-2 2006-04-01 08:41:04.000000000 +0200
+++ dist/doc/make.info-2 1970-01-01 01:00:00.000000000 +0100
@@ -1,4393 +0,0 @@
-This is make.info, produced by makeinfo version 4.8 from make.texi.
-
- This file documents the GNU `make' utility, which determines
-automatically which pieces of a large program need to be recompiled,
-and issues the commands to recompile them.
-
- This is Edition 0.70, last updated 1 April 2006, of `The GNU Make
-Manual', for GNU `make' version 3.81.
-
- Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
-1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006 Free Software
-Foundation, Inc.
-
- Permission is granted to copy, distribute and/or modify this
- document under the terms of the GNU Free Documentation License,
- Version 1.2 or any later version published by the Free Software
- Foundation; with no Invariant Sections, with the Front-Cover Texts
- being "A GNU Manual," and with the Back-Cover Texts as in (a)
- below. A copy of the license is included in the section entitled
- "GNU Free Documentation License."
-
- (a) The FSF's Back-Cover Text is: "You have freedom to copy and
- modify this GNU Manual, like GNU software. Copies published by
- the Free Software Foundation raise funds for GNU development."
-
-INFO-DIR-SECTION GNU Packages
-START-INFO-DIR-ENTRY
-* Make: (make). Remake files automatically.
-END-INFO-DIR-ENTRY
-
-
-File: make.info, Node: Pattern Rules, Next: Last Resort, Prev: Chained Rules, Up: Implicit Rules
-
-10.5 Defining and Redefining Pattern Rules
-==========================================
-
-You define an implicit rule by writing a "pattern rule". A pattern
-rule looks like an ordinary rule, except that its target contains the
-character `%' (exactly one of them). The target is considered a
-pattern for matching file names; the `%' can match any nonempty
-substring, while other characters match only themselves. The
-prerequisites likewise use `%' to show how their names relate to the
-target name.
-
- Thus, a pattern rule `%.o : %.c' says how to make any file `STEM.o'
-from another file `STEM.c'.
-
- Note that expansion using `%' in pattern rules occurs *after* any
-variable or function expansions, which take place when the makefile is
-read. *Note How to Use Variables: Using Variables, and *Note Functions
-for Transforming Text: Functions.
-
-* Menu:
-
-* Pattern Intro:: An introduction to pattern rules.
-* Pattern Examples:: Examples of pattern rules.
-* Automatic Variables:: How to use automatic variables in the
- commands of implicit rules.
-* Pattern Match:: How patterns match.
-* Match-Anything Rules:: Precautions you should take prior to
- defining rules that can match any
- target file whatever.
-* Canceling Rules:: How to override or cancel built-in rules.
-
-
-File: make.info, Node: Pattern Intro, Next: Pattern Examples, Prev: Pattern Rules, Up: Pattern Rules
-
-10.5.1 Introduction to Pattern Rules
-------------------------------------
-
-A pattern rule contains the character `%' (exactly one of them) in the
-target; otherwise, it looks exactly like an ordinary rule. The target
-is a pattern for matching file names; the `%' matches any nonempty
-substring, while other characters match only themselves.
-
- For example, `%.c' as a pattern matches any file name that ends in
-`.c'. `s.%.c' as a pattern matches any file name that starts with
-`s.', ends in `.c' and is at least five characters long. (There must
-be at least one character to match the `%'.) The substring that the
-`%' matches is called the "stem".
-
- `%' in a prerequisite of a pattern rule stands for the same stem
-that was matched by the `%' in the target. In order for the pattern
-rule to apply, its target pattern must match the file name under
-consideration and all of its prerequisites (after pattern substitution)
-must name files that exist or can be made. These files become
-prerequisites of the target.
-
- Thus, a rule of the form
-
- %.o : %.c ; COMMAND...
-
-specifies how to make a file `N.o', with another file `N.c' as its
-prerequisite, provided that `N.c' exists or can be made.
-
- There may also be prerequisites that do not use `%'; such a
-prerequisite attaches to every file made by this pattern rule. These
-unvarying prerequisites are useful occasionally.
-
- A pattern rule need not have any prerequisites that contain `%', or
-in fact any prerequisites at all. Such a rule is effectively a general
-wildcard. It provides a way to make any file that matches the target
-pattern. *Note Last Resort::.
-
- Pattern rules may have more than one target. Unlike normal rules,
-this does not act as many different rules with the same prerequisites
-and commands. If a pattern rule has multiple targets, `make' knows that
-the rule's commands are responsible for making all of the targets. The
-commands are executed only once to make all the targets. When searching
-for a pattern rule to match a target, the target patterns of a rule
-other than the one that matches the target in need of a rule are
-incidental: `make' worries only about giving commands and prerequisites
-to the file presently in question. However, when this file's commands
-are run, the other targets are marked as having been updated themselves.
-
- The order in which pattern rules appear in the makefile is important
-since this is the order in which they are considered. Of equally
-applicable rules, only the first one found is used. The rules you
-write take precedence over those that are built in. Note however, that
-a rule whose prerequisites actually exist or are mentioned always takes
-priority over a rule with prerequisites that must be made by chaining
-other implicit rules.
-
-
-File: make.info, Node: Pattern Examples, Next: Automatic Variables, Prev: Pattern Intro, Up: Pattern Rules
-
-10.5.2 Pattern Rule Examples
-----------------------------
-
-Here are some examples of pattern rules actually predefined in `make'.
-First, the rule that compiles `.c' files into `.o' files:
-
- %.o : %.c
- $(CC) -c $(CFLAGS) $(CPPFLAGS) $< -o $@
-
-defines a rule that can make any file `X.o' from `X.c'. The command
-uses the automatic variables `$@' and `$<' to substitute the names of
-the target file and the source file in each case where the rule applies
-(*note Automatic Variables::).
-
- Here is a second built-in rule:
-
- % :: RCS/%,v
- $(CO) $(COFLAGS) $<
-
-defines a rule that can make any file `X' whatsoever from a
-corresponding file `X,v' in the subdirectory `RCS'. Since the target
-is `%', this rule will apply to any file whatever, provided the
-appropriate prerequisite file exists. The double colon makes the rule
-"terminal", which means that its prerequisite may not be an intermediate
-file (*note Match-Anything Pattern Rules: Match-Anything Rules.).
-
- This pattern rule has two targets:
-
- %.tab.c %.tab.h: %.y
- bison -d $<
-
-This tells `make' that the command `bison -d X.y' will make both
-`X.tab.c' and `X.tab.h'. If the file `foo' depends on the files
-`parse.tab.o' and `scan.o' and the file `scan.o' depends on the file
-`parse.tab.h', when `parse.y' is changed, the command `bison -d parse.y'
-will be executed only once, and the prerequisites of both `parse.tab.o'
-and `scan.o' will be satisfied. (Presumably the file `parse.tab.o'
-will be recompiled from `parse.tab.c' and the file `scan.o' from
-`scan.c', while `foo' is linked from `parse.tab.o', `scan.o', and its
-other prerequisites, and it will execute happily ever after.)
-
-
-File: make.info, Node: Automatic Variables, Next: Pattern Match, Prev: Pattern Examples, Up: Pattern Rules
-
-10.5.3 Automatic Variables
---------------------------
-
-Suppose you are writing a pattern rule to compile a `.c' file into a
-`.o' file: how do you write the `cc' command so that it operates on the
-right source file name? You cannot write the name in the command,
-because the name is different each time the implicit rule is applied.
-
- What you do is use a special feature of `make', the "automatic
-variables". These variables have values computed afresh for each rule
-that is executed, based on the target and prerequisites of the rule.
-In this example, you would use `$@' for the object file name and `$<'
-for the source file name.
-
- It's very important that you recognize the limited scope in which
-automatic variable values are available: they only have values within
-the command script. In particular, you cannot use them anywhere within
-the target list of a rule; they have no value there and will expand to
-the empty string. Also, they cannot be accessed directly within the
-prerequisite list of a rule. A common mistake is attempting to use
-`$@' within the prerequisites list; this will not work. However, there
-is a special feature of GNU `make', secondary expansion (*note
-Secondary Expansion::), which will allow automatic variable values to
-be used in prerequisite lists.
-
- Here is a table of automatic variables:
-
-`$@'
- The file name of the target of the rule. If the target is an
- archive member, then `$@' is the name of the archive file. In a
- pattern rule that has multiple targets (*note Introduction to
- Pattern Rules: Pattern Intro.), `$@' is the name of whichever
- target caused the rule's commands to be run.
-
-`$%'
- The target member name, when the target is an archive member.
- *Note Archives::. For example, if the target is `foo.a(bar.o)'
- then `$%' is `bar.o' and `$@' is `foo.a'. `$%' is empty when the
- target is not an archive member.
-
-`$<'
- The name of the first prerequisite. If the target got its
- commands from an implicit rule, this will be the first
- prerequisite added by the implicit rule (*note Implicit Rules::).
-
-`$?'
- The names of all the prerequisites that are newer than the target,
- with spaces between them. For prerequisites which are archive
- members, only the member named is used (*note Archives::).
-
-`$^'
- The names of all the prerequisites, with spaces between them. For
- prerequisites which are archive members, only the member named is
- used (*note Archives::). A target has only one prerequisite on
- each other file it depends on, no matter how many times each file
- is listed as a prerequisite. So if you list a prerequisite more
- than once for a target, the value of `$^' contains just one copy
- of the name. This list does *not* contain any of the order-only
- prerequisites; for those see the `$|' variable, below.
-
-`$+'
- This is like `$^', but prerequisites listed more than once are
- duplicated in the order they were listed in the makefile. This is
- primarily useful for use in linking commands where it is
- meaningful to repeat library file names in a particular order.
-
-`$|'
- The names of all the order-only prerequisites, with spaces between
- them.
-
-`$*'
- The stem with which an implicit rule matches (*note How Patterns
- Match: Pattern Match.). If the target is `dir/a.foo.b' and the
- target pattern is `a.%.b' then the stem is `dir/foo'. The stem is
- useful for constructing names of related files.
-
- In a static pattern rule, the stem is part of the file name that
- matched the `%' in the target pattern.
-
- In an explicit rule, there is no stem; so `$*' cannot be determined
- in that way. Instead, if the target name ends with a recognized
- suffix (*note Old-Fashioned Suffix Rules: Suffix Rules.), `$*' is
- set to the target name minus the suffix. For example, if the
- target name is `foo.c', then `$*' is set to `foo', since `.c' is a
- suffix. GNU `make' does this bizarre thing only for compatibility
- with other implementations of `make'. You should generally avoid
- using `$*' except in implicit rules or static pattern rules.
-
- If the target name in an explicit rule does not end with a
- recognized suffix, `$*' is set to the empty string for that rule.
-
- `$?' is useful even in explicit rules when you wish to operate on
-only the prerequisites that have changed. For example, suppose that an
-archive named `lib' is supposed to contain copies of several object
-files. This rule copies just the changed object files into the archive:
-
- lib: foo.o bar.o lose.o win.o
- ar r lib $?
-
- Of the variables listed above, four have values that are single file
-names, and three have values that are lists of file names. These seven
-have variants that get just the file's directory name or just the file
-name within the directory. The variant variables' names are formed by
-appending `D' or `F', respectively. These variants are semi-obsolete
-in GNU `make' since the functions `dir' and `notdir' can be used to get
-a similar effect (*note Functions for File Names: File Name
-Functions.). Note, however, that the `D' variants all omit the
-trailing slash which always appears in the output of the `dir'
-function. Here is a table of the variants:
-
-`$(@D)'
- The directory part of the file name of the target, with the
- trailing slash removed. If the value of `$@' is `dir/foo.o' then
- `$(@D)' is `dir'. This value is `.' if `$@' does not contain a
- slash.
-
-`$(@F)'
- The file-within-directory part of the file name of the target. If
- the value of `$@' is `dir/foo.o' then `$(@F)' is `foo.o'. `$(@F)'
- is equivalent to `$(notdir $@)'.
-
-`$(*D)'
-`$(*F)'
- The directory part and the file-within-directory part of the stem;
- `dir' and `foo' in this example.
-
-`$(%D)'
-`$(%F)'
- The directory part and the file-within-directory part of the target
- archive member name. This makes sense only for archive member
- targets of the form `ARCHIVE(MEMBER)' and is useful only when
- MEMBER may contain a directory name. (*Note Archive Members as
- Targets: Archive Members.)
-
-`$(<D)'
-`$(<F)'
- The directory part and the file-within-directory part of the first
- prerequisite.
-
-`$(^D)'
-`$(^F)'
- Lists of the directory parts and the file-within-directory parts
- of all prerequisites.
-
-`$(+D)'
-`$(+F)'
- Lists of the directory parts and the file-within-directory parts
- of all prerequisites, including multiple instances of duplicated
- prerequisites.
-
-`$(?D)'
-`$(?F)'
- Lists of the directory parts and the file-within-directory parts of
- all prerequisites that are newer than the target.
-
- Note that we use a special stylistic convention when we talk about
-these automatic variables; we write "the value of `$<'", rather than
-"the variable `<'" as we would write for ordinary variables such as
-`objects' and `CFLAGS'. We think this convention looks more natural in
-this special case. Please do not assume it has a deep significance;
-`$<' refers to the variable named `<' just as `$(CFLAGS)' refers to the
-variable named `CFLAGS'. You could just as well use `$(<)' in place of
-`$<'.
-
-
-File: make.info, Node: Pattern Match, Next: Match-Anything Rules, Prev: Automatic Variables, Up: Pattern Rules
-
-10.5.4 How Patterns Match
--------------------------
-
-A target pattern is composed of a `%' between a prefix and a suffix,
-either or both of which may be empty. The pattern matches a file name
-only if the file name starts with the prefix and ends with the suffix,
-without overlap. The text between the prefix and the suffix is called
-the "stem". Thus, when the pattern `%.o' matches the file name
-`test.o', the stem is `test'. The pattern rule prerequisites are
-turned into actual file names by substituting the stem for the character
-`%'. Thus, if in the same example one of the prerequisites is written
-as `%.c', it expands to `test.c'.
-
- When the target pattern does not contain a slash (and it usually does
-not), directory names in the file names are removed from the file name
-before it is compared with the target prefix and suffix. After the
-comparison of the file name to the target pattern, the directory names,
-along with the slash that ends them, are added on to the prerequisite
-file names generated from the pattern rule's prerequisite patterns and
-the file name. The directories are ignored only for the purpose of
-finding an implicit rule to use, not in the application of that rule.
-Thus, `e%t' matches the file name `src/eat', with `src/a' as the stem.
-When prerequisites are turned into file names, the directories from the
-stem are added at the front, while the rest of the stem is substituted
-for the `%'. The stem `src/a' with a prerequisite pattern `c%r' gives
-the file name `src/car'.
-
-
-File: make.info, Node: Match-Anything Rules, Next: Canceling Rules, Prev: Pattern Match, Up: Pattern Rules
-
-10.5.5 Match-Anything Pattern Rules
------------------------------------
-
-When a pattern rule's target is just `%', it matches any file name
-whatever. We call these rules "match-anything" rules. They are very
-useful, but it can take a lot of time for `make' to think about them,
-because it must consider every such rule for each file name listed
-either as a target or as a prerequisite.
-
- Suppose the makefile mentions `foo.c'. For this target, `make'
-would have to consider making it by linking an object file `foo.c.o',
-or by C compilation-and-linking in one step from `foo.c.c', or by
-Pascal compilation-and-linking from `foo.c.p', and many other
-possibilities.
-
- We know these possibilities are ridiculous since `foo.c' is a C
-source file, not an executable. If `make' did consider these
-possibilities, it would ultimately reject them, because files such as
-`foo.c.o' and `foo.c.p' would not exist. But these possibilities are so
-numerous that `make' would run very slowly if it had to consider them.
-
- To gain speed, we have put various constraints on the way `make'
-considers match-anything rules. There are two different constraints
-that can be applied, and each time you define a match-anything rule you
-must choose one or the other for that rule.
-
- One choice is to mark the match-anything rule as "terminal" by
-defining it with a double colon. When a rule is terminal, it does not
-apply unless its prerequisites actually exist. Prerequisites that
-could be made with other implicit rules are not good enough. In other
-words, no further chaining is allowed beyond a terminal rule.
-
- For example, the built-in implicit rules for extracting sources from
-RCS and SCCS files are terminal; as a result, if the file `foo.c,v' does
-not exist, `make' will not even consider trying to make it as an
-intermediate file from `foo.c,v.o' or from `RCS/SCCS/s.foo.c,v'. RCS
-and SCCS files are generally ultimate source files, which should not be
-remade from any other files; therefore, `make' can save time by not
-looking for ways to remake them.
-
- If you do not mark the match-anything rule as terminal, then it is
-nonterminal. A nonterminal match-anything rule cannot apply to a file
-name that indicates a specific type of data. A file name indicates a
-specific type of data if some non-match-anything implicit rule target
-matches it.
-
- For example, the file name `foo.c' matches the target for the pattern
-rule `%.c : %.y' (the rule to run Yacc). Regardless of whether this
-rule is actually applicable (which happens only if there is a file
-`foo.y'), the fact that its target matches is enough to prevent
-consideration of any nonterminal match-anything rules for the file
-`foo.c'. Thus, `make' will not even consider trying to make `foo.c' as
-an executable file from `foo.c.o', `foo.c.c', `foo.c.p', etc.
-
- The motivation for this constraint is that nonterminal match-anything
-rules are used for making files containing specific types of data (such
-as executable files) and a file name with a recognized suffix indicates
-some other specific type of data (such as a C source file).
-
- Special built-in dummy pattern rules are provided solely to recognize
-certain file names so that nonterminal match-anything rules will not be
-considered. These dummy rules have no prerequisites and no commands,
-and they are ignored for all other purposes. For example, the built-in
-implicit rule
-
- %.p :
-
-exists to make sure that Pascal source files such as `foo.p' match a
-specific target pattern and thereby prevent time from being wasted
-looking for `foo.p.o' or `foo.p.c'.
-
- Dummy pattern rules such as the one for `%.p' are made for every
-suffix listed as valid for use in suffix rules (*note Old-Fashioned
-Suffix Rules: Suffix Rules.).
-
-
-File: make.info, Node: Canceling Rules, Prev: Match-Anything Rules, Up: Pattern Rules
-
-10.5.6 Canceling Implicit Rules
--------------------------------
-
-You can override a built-in implicit rule (or one you have defined
-yourself) by defining a new pattern rule with the same target and
-prerequisites, but different commands. When the new rule is defined,
-the built-in one is replaced. The new rule's position in the sequence
-of implicit rules is determined by where you write the new rule.
-
- You can cancel a built-in implicit rule by defining a pattern rule
-with the same target and prerequisites, but no commands. For example,
-the following would cancel the rule that runs the assembler:
-
- %.o : %.s
-
-
-File: make.info, Node: Last Resort, Next: Suffix Rules, Prev: Pattern Rules, Up: Implicit Rules
-
-10.6 Defining Last-Resort Default Rules
-=======================================
-
-You can define a last-resort implicit rule by writing a terminal
-match-anything pattern rule with no prerequisites (*note Match-Anything
-Rules::). This is just like any other pattern rule; the only thing
-special about it is that it will match any target. So such a rule's
-commands are used for all targets and prerequisites that have no
-commands of their own and for which no other implicit rule applies.
-
- For example, when testing a makefile, you might not care if the
-source files contain real data, only that they exist. Then you might
-do this:
-
- %::
- touch $@
-
-to cause all the source files needed (as prerequisites) to be created
-automatically.
-
- You can instead define commands to be used for targets for which
-there are no rules at all, even ones which don't specify commands. You
-do this by writing a rule for the target `.DEFAULT'. Such a rule's
-commands are used for all prerequisites which do not appear as targets
-in any explicit rule, and for which no implicit rule applies.
-Naturally, there is no `.DEFAULT' rule unless you write one.
-
- If you use `.DEFAULT' with no commands or prerequisites:
-
- .DEFAULT:
-
-the commands previously stored for `.DEFAULT' are cleared. Then `make'
-acts as if you had never defined `.DEFAULT' at all.
-
- If you do not want a target to get the commands from a match-anything
-pattern rule or `.DEFAULT', but you also do not want any commands to be
-run for the target, you can give it empty commands (*note Defining
-Empty Commands: Empty Commands.).
-
- You can use a last-resort rule to override part of another makefile.
-*Note Overriding Part of Another Makefile: Overriding Makefiles.
-
-
-File: make.info, Node: Suffix Rules, Next: Implicit Rule Search, Prev: Last Resort, Up: Implicit Rules
-
-10.7 Old-Fashioned Suffix Rules
-===============================
-
-"Suffix rules" are the old-fashioned way of defining implicit rules for
-`make'. Suffix rules are obsolete because pattern rules are more
-general and clearer. They are supported in GNU `make' for
-compatibility with old makefiles. They come in two kinds:
-"double-suffix" and "single-suffix".
-
- A double-suffix rule is defined by a pair of suffixes: the target
-suffix and the source suffix. It matches any file whose name ends with
-the target suffix. The corresponding implicit prerequisite is made by
-replacing the target suffix with the source suffix in the file name. A
-two-suffix rule whose target and source suffixes are `.o' and `.c' is
-equivalent to the pattern rule `%.o : %.c'.
-
- A single-suffix rule is defined by a single suffix, which is the
-source suffix. It matches any file name, and the corresponding implicit
-prerequisite name is made by appending the source suffix. A
-single-suffix rule whose source suffix is `.c' is equivalent to the
-pattern rule `% : %.c'.
-
- Suffix rule definitions are recognized by comparing each rule's
-target against a defined list of known suffixes. When `make' sees a
-rule whose target is a known suffix, this rule is considered a
-single-suffix rule. When `make' sees a rule whose target is two known
-suffixes concatenated, this rule is taken as a double-suffix rule.
-
- For example, `.c' and `.o' are both on the default list of known
-suffixes. Therefore, if you define a rule whose target is `.c.o',
-`make' takes it to be a double-suffix rule with source suffix `.c' and
-target suffix `.o'. Here is the old-fashioned way to define the rule
-for compiling a C source file:
-
- .c.o:
- $(CC) -c $(CFLAGS) $(CPPFLAGS) -o $@ $<
-
- Suffix rules cannot have any prerequisites of their own. If they
-have any, they are treated as normal files with funny names, not as
-suffix rules. Thus, the rule:
-
- .c.o: foo.h
- $(CC) -c $(CFLAGS) $(CPPFLAGS) -o $@ $<
-
-tells how to make the file `.c.o' from the prerequisite file `foo.h',
-and is not at all like the pattern rule:
-
- %.o: %.c foo.h
- $(CC) -c $(CFLAGS) $(CPPFLAGS) -o $@ $<
-
-which tells how to make `.o' files from `.c' files, and makes all `.o'
-files using this pattern rule also depend on `foo.h'.
-
- Suffix rules with no commands are also meaningless. They do not
-remove previous rules as do pattern rules with no commands (*note
-Canceling Implicit Rules: Canceling Rules.). They simply enter the
-suffix or pair of suffixes concatenated as a target in the data base.
-
- The known suffixes are simply the names of the prerequisites of the
-special target `.SUFFIXES'. You can add your own suffixes by writing a
-rule for `.SUFFIXES' that adds more prerequisites, as in:
-
- .SUFFIXES: .hack .win
-
-which adds `.hack' and `.win' to the end of the list of suffixes.
-
- If you wish to eliminate the default known suffixes instead of just
-adding to them, write a rule for `.SUFFIXES' with no prerequisites. By
-special dispensation, this eliminates all existing prerequisites of
-`.SUFFIXES'. You can then write another rule to add the suffixes you
-want. For example,
-
- .SUFFIXES: # Delete the default suffixes
- .SUFFIXES: .c .o .h # Define our suffix list
-
- The `-r' or `--no-builtin-rules' flag causes the default list of
-suffixes to be empty.
-
- The variable `SUFFIXES' is defined to the default list of suffixes
-before `make' reads any makefiles. You can change the list of suffixes
-with a rule for the special target `.SUFFIXES', but that does not alter
-this variable.
-
-
-File: make.info, Node: Implicit Rule Search, Prev: Suffix Rules, Up: Implicit Rules
-
-10.8 Implicit Rule Search Algorithm
-===================================
-
-Here is the procedure `make' uses for searching for an implicit rule
-for a target T. This procedure is followed for each double-colon rule
-with no commands, for each target of ordinary rules none of which have
-commands, and for each prerequisite that is not the target of any rule.
-It is also followed recursively for prerequisites that come from
-implicit rules, in the search for a chain of rules.
-
- Suffix rules are not mentioned in this algorithm because suffix
-rules are converted to equivalent pattern rules once the makefiles have
-been read in.
-
- For an archive member target of the form `ARCHIVE(MEMBER)', the
-following algorithm is run twice, first using the entire target name T,
-and second using `(MEMBER)' as the target T if the first run found no
-rule.
-
- 1. Split T into a directory part, called D, and the rest, called N.
- For example, if T is `src/foo.o', then D is `src/' and N is
- `foo.o'.
-
- 2. Make a list of all the pattern rules one of whose targets matches
- T or N. If the target pattern contains a slash, it is matched
- against T; otherwise, against N.
-
- 3. If any rule in that list is _not_ a match-anything rule, then
- remove all nonterminal match-anything rules from the list.
-
- 4. Remove from the list all rules with no commands.
-
- 5. For each pattern rule in the list:
-
- a. Find the stem S, which is the nonempty part of T or N matched
- by the `%' in the target pattern.
-
- b. Compute the prerequisite names by substituting S for `%'; if
- the target pattern does not contain a slash, append D to the
- front of each prerequisite name.
-
- c. Test whether all the prerequisites exist or ought to exist.
- (If a file name is mentioned in the makefile as a target or
- as an explicit prerequisite, then we say it ought to exist.)
-
- If all prerequisites exist or ought to exist, or there are no
- prerequisites, then this rule applies.
-
- 6. If no pattern rule has been found so far, try harder. For each
- pattern rule in the list:
-
- a. If the rule is terminal, ignore it and go on to the next rule.
-
- b. Compute the prerequisite names as before.
-
- c. Test whether all the prerequisites exist or ought to exist.
-
- d. For each prerequisite that does not exist, follow this
- algorithm recursively to see if the prerequisite can be made
- by an implicit rule.
-
- e. If all prerequisites exist, ought to exist, or can be made by
- implicit rules, then this rule applies.
-
- 7. If no implicit rule applies, the rule for `.DEFAULT', if any,
- applies. In that case, give T the same commands that `.DEFAULT'
- has. Otherwise, there are no commands for T.
-
- Once a rule that applies has been found, for each target pattern of
-the rule other than the one that matched T or N, the `%' in the pattern
-is replaced with S and the resultant file name is stored until the
-commands to remake the target file T are executed. After these
-commands are executed, each of these stored file names are entered into
-the data base and marked as having been updated and having the same
-update status as the file T.
-
- When the commands of a pattern rule are executed for T, the automatic
-variables are set corresponding to the target and prerequisites. *Note
-Automatic Variables::.
-
-
-File: make.info, Node: Archives, Next: Features, Prev: Implicit Rules, Up: Top
-
-11 Using `make' to Update Archive Files
-***************************************
-
-"Archive files" are files containing named subfiles called "members";
-they are maintained with the program `ar' and their main use is as
-subroutine libraries for linking.
-
-* Menu:
-
-* Archive Members:: Archive members as targets.
-* Archive Update:: The implicit rule for archive member targets.
-* Archive Pitfalls:: Dangers to watch out for when using archives.
-* Archive Suffix Rules:: You can write a special kind of suffix rule
- for updating archives.
-
-
-File: make.info, Node: Archive Members, Next: Archive Update, Prev: Archives, Up: Archives
-
-11.1 Archive Members as Targets
-===============================
-
-An individual member of an archive file can be used as a target or
-prerequisite in `make'. You specify the member named MEMBER in archive
-file ARCHIVE as follows:
-
- ARCHIVE(MEMBER)
-
-This construct is available only in targets and prerequisites, not in
-commands! Most programs that you might use in commands do not support
-this syntax and cannot act directly on archive members. Only `ar' and
-other programs specifically designed to operate on archives can do so.
-Therefore, valid commands to update an archive member target probably
-must use `ar'. For example, this rule says to create a member `hack.o'
-in archive `foolib' by copying the file `hack.o':
-
- foolib(hack.o) : hack.o
- ar cr foolib hack.o
-
- In fact, nearly all archive member targets are updated in just this
-way and there is an implicit rule to do it for you. *Please note:* The
-`c' flag to `ar' is required if the archive file does not already exist.
-
- To specify several members in the same archive, you can write all the
-member names together between the parentheses. For example:
-
- foolib(hack.o kludge.o)
-
-is equivalent to:
-
- foolib(hack.o) foolib(kludge.o)
-
- You can also use shell-style wildcards in an archive member
-reference. *Note Using Wildcard Characters in File Names: Wildcards.
-For example, `foolib(*.o)' expands to all existing members of the
-`foolib' archive whose names end in `.o'; perhaps `foolib(hack.o)
-foolib(kludge.o)'.
-
-
-File: make.info, Node: Archive Update, Next: Archive Pitfalls, Prev: Archive Members, Up: Archives
-
-11.2 Implicit Rule for Archive Member Targets
-=============================================
-
-Recall that a target that looks like `A(M)' stands for the member named
-M in the archive file A.
-
- When `make' looks for an implicit rule for such a target, as a
-special feature it considers implicit rules that match `(M)', as well as
-those that match the actual target `A(M)'.
-
- This causes one special rule whose target is `(%)' to match. This
-rule updates the target `A(M)' by copying the file M into the archive.
-For example, it will update the archive member target `foo.a(bar.o)' by
-copying the _file_ `bar.o' into the archive `foo.a' as a _member_ named
-`bar.o'.
-
- When this rule is chained with others, the result is very powerful.
-Thus, `make "foo.a(bar.o)"' (the quotes are needed to protect the `('
-and `)' from being interpreted specially by the shell) in the presence
-of a file `bar.c' is enough to cause the following commands to be run,
-even without a makefile:
-
- cc -c bar.c -o bar.o
- ar r foo.a bar.o
- rm -f bar.o
-
-Here `make' has envisioned the file `bar.o' as an intermediate file.
-*Note Chains of Implicit Rules: Chained Rules.
-
- Implicit rules such as this one are written using the automatic
-variable `$%'. *Note Automatic Variables::.
-
- An archive member name in an archive cannot contain a directory
-name, but it may be useful in a makefile to pretend that it does. If
-you write an archive member target `foo.a(dir/file.o)', `make' will
-perform automatic updating with this command:
-
- ar r foo.a dir/file.o
-
-which has the effect of copying the file `dir/file.o' into a member
-named `file.o'. In connection with such usage, the automatic variables
-`%D' and `%F' may be useful.
-
-* Menu:
-
-* Archive Symbols:: How to update archive symbol directories.
-
-
-File: make.info, Node: Archive Symbols, Prev: Archive Update, Up: Archive Update
-
-11.2.1 Updating Archive Symbol Directories
-------------------------------------------
-
-An archive file that is used as a library usually contains a special
-member named `__.SYMDEF' that contains a directory of the external
-symbol names defined by all the other members. After you update any
-other members, you need to update `__.SYMDEF' so that it will summarize
-the other members properly. This is done by running the `ranlib'
-program:
-
- ranlib ARCHIVEFILE
-
- Normally you would put this command in the rule for the archive file,
-and make all the members of the archive file prerequisites of that rule.
-For example,
-
- libfoo.a: libfoo.a(x.o) libfoo.a(y.o) ...
- ranlib libfoo.a
-
-The effect of this is to update archive members `x.o', `y.o', etc., and
-then update the symbol directory member `__.SYMDEF' by running
-`ranlib'. The rules for updating the members are not shown here; most
-likely you can omit them and use the implicit rule which copies files
-into the archive, as described in the preceding section.
-
- This is not necessary when using the GNU `ar' program, which updates
-the `__.SYMDEF' member automatically.
-
-
-File: make.info, Node: Archive Pitfalls, Next: Archive Suffix Rules, Prev: Archive Update, Up: Archives
-
-11.3 Dangers When Using Archives
-================================
-
-It is important to be careful when using parallel execution (the `-j'
-switch; *note Parallel Execution: Parallel.) and archives. If multiple
-`ar' commands run at the same time on the same archive file, they will
-not know about each other and can corrupt the file.
-
- Possibly a future version of `make' will provide a mechanism to
-circumvent this problem by serializing all commands that operate on the
-same archive file. But for the time being, you must either write your
-makefiles to avoid this problem in some other way, or not use `-j'.
-
-
-File: make.info, Node: Archive Suffix Rules, Prev: Archive Pitfalls, Up: Archives
-
-11.4 Suffix Rules for Archive Files
-===================================
-
-You can write a special kind of suffix rule for dealing with archive
-files. *Note Suffix Rules::, for a full explanation of suffix rules.
-Archive suffix rules are obsolete in GNU `make', because pattern rules
-for archives are a more general mechanism (*note Archive Update::).
-But they are retained for compatibility with other `make's.
-
- To write a suffix rule for archives, you simply write a suffix rule
-using the target suffix `.a' (the usual suffix for archive files). For
-example, here is the old-fashioned suffix rule to update a library
-archive from C source files:
-
- .c.a:
- $(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $*.o
- $(AR) r $@ $*.o
- $(RM) $*.o
-
-This works just as if you had written the pattern rule:
-
- (%.o): %.c
- $(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $*.o
- $(AR) r $@ $*.o
- $(RM) $*.o
-
- In fact, this is just what `make' does when it sees a suffix rule
-with `.a' as the target suffix. Any double-suffix rule `.X.a' is
-converted to a pattern rule with the target pattern `(%.o)' and a
-prerequisite pattern of `%.X'.
-
- Since you might want to use `.a' as the suffix for some other kind
-of file, `make' also converts archive suffix rules to pattern rules in
-the normal way (*note Suffix Rules::). Thus a double-suffix rule
-`.X.a' produces two pattern rules: `(%.o): %.X' and `%.a: %.X'.
-
-
-File: make.info, Node: Features, Next: Missing, Prev: Archives, Up: Top
-
-12 Features of GNU `make'
-*************************
-
-Here is a summary of the features of GNU `make', for comparison with
-and credit to other versions of `make'. We consider the features of
-`make' in 4.2 BSD systems as a baseline. If you are concerned with
-writing portable makefiles, you should not use the features of `make'
-listed here, nor the ones in *Note Missing::.
-
- Many features come from the version of `make' in System V.
-
- * The `VPATH' variable and its special meaning. *Note Searching
- Directories for Prerequisites: Directory Search. This feature
- exists in System V `make', but is undocumented. It is documented
- in 4.3 BSD `make' (which says it mimics System V's `VPATH'
- feature).
-
- * Included makefiles. *Note Including Other Makefiles: Include.
- Allowing multiple files to be included with a single directive is
- a GNU extension.
-
- * Variables are read from and communicated via the environment.
- *Note Variables from the Environment: Environment.
-
- * Options passed through the variable `MAKEFLAGS' to recursive
- invocations of `make'. *Note Communicating Options to a
- Sub-`make': Options/Recursion.
-
- * The automatic variable `$%' is set to the member name in an
- archive reference. *Note Automatic Variables::.
-
- * The automatic variables `$@', `$*', `$<', `$%', and `$?' have
- corresponding forms like `$(@F)' and `$(@D)'. We have generalized
- this to `$^' as an obvious extension. *Note Automatic Variables::.
-
- * Substitution variable references. *Note Basics of Variable
- References: Reference.
-
- * The command-line options `-b' and `-m', accepted and ignored. In
- System V `make', these options actually do something.
-
- * Execution of recursive commands to run `make' via the variable
- `MAKE' even if `-n', `-q' or `-t' is specified. *Note Recursive
- Use of `make': Recursion.
-
- * Support for suffix `.a' in suffix rules. *Note Archive Suffix
- Rules::. This feature is obsolete in GNU `make', because the
- general feature of rule chaining (*note Chains of Implicit Rules:
- Chained Rules.) allows one pattern rule for installing members in
- an archive (*note Archive Update::) to be sufficient.
-
- * The arrangement of lines and backslash-newline combinations in
- commands is retained when the commands are printed, so they appear
- as they do in the makefile, except for the stripping of initial
- whitespace.
-
- The following features were inspired by various other versions of
-`make'. In some cases it is unclear exactly which versions inspired
-which others.
-
- * Pattern rules using `%'. This has been implemented in several
- versions of `make'. We're not sure who invented it first, but
- it's been spread around a bit. *Note Defining and Redefining
- Pattern Rules: Pattern Rules.
-
- * Rule chaining and implicit intermediate files. This was
- implemented by Stu Feldman in his version of `make' for AT&T
- Eighth Edition Research Unix, and later by Andrew Hume of AT&T
- Bell Labs in his `mk' program (where he terms it "transitive
- closure"). We do not really know if we got this from either of
- them or thought it up ourselves at the same time. *Note Chains of
- Implicit Rules: Chained Rules.
-
- * The automatic variable `$^' containing a list of all prerequisites
- of the current target. We did not invent this, but we have no
- idea who did. *Note Automatic Variables::. The automatic variable
- `$+' is a simple extension of `$^'.
-
- * The "what if" flag (`-W' in GNU `make') was (as far as we know)
- invented by Andrew Hume in `mk'. *Note Instead of Executing the
- Commands: Instead of Execution.
-
- * The concept of doing several things at once (parallelism) exists in
- many incarnations of `make' and similar programs, though not in the
- System V or BSD implementations. *Note Command Execution:
- Execution.
-
- * Modified variable references using pattern substitution come from
- SunOS 4. *Note Basics of Variable References: Reference. This
- functionality was provided in GNU `make' by the `patsubst'
- function before the alternate syntax was implemented for
- compatibility with SunOS 4. It is not altogether clear who
- inspired whom, since GNU `make' had `patsubst' before SunOS 4 was
- released.
-
- * The special significance of `+' characters preceding command lines
- (*note Instead of Executing the Commands: Instead of Execution.) is
- mandated by `IEEE Standard 1003.2-1992' (POSIX.2).
-
- * The `+=' syntax to append to the value of a variable comes from
- SunOS 4 `make'. *Note Appending More Text to Variables: Appending.
-
- * The syntax `ARCHIVE(MEM1 MEM2...)' to list multiple members in a
- single archive file comes from SunOS 4 `make'. *Note Archive
- Members::.
-
- * The `-include' directive to include makefiles with no error for a
- nonexistent file comes from SunOS 4 `make'. (But note that SunOS 4
- `make' does not allow multiple makefiles to be specified in one
- `-include' directive.) The same feature appears with the name
- `sinclude' in SGI `make' and perhaps others.
-
- The remaining features are inventions new in GNU `make':
-
- * Use the `-v' or `--version' option to print version and copyright
- information.
-
- * Use the `-h' or `--help' option to summarize the options to `make'.
-
- * Simply-expanded variables. *Note The Two Flavors of Variables:
- Flavors.
-
- * Pass command-line variable assignments automatically through the
- variable `MAKE' to recursive `make' invocations. *Note Recursive
- Use of `make': Recursion.
-
- * Use the `-C' or `--directory' command option to change directory.
- *Note Summary of Options: Options Summary.
-
- * Make verbatim variable definitions with `define'. *Note Defining
- Variables Verbatim: Defining.
-
- * Declare phony targets with the special target `.PHONY'.
-
- Andrew Hume of AT&T Bell Labs implemented a similar feature with a
- different syntax in his `mk' program. This seems to be a case of
- parallel discovery. *Note Phony Targets: Phony Targets.
-
- * Manipulate text by calling functions. *Note Functions for
- Transforming Text: Functions.
-
- * Use the `-o' or `--old-file' option to pretend a file's
- modification-time is old. *Note Avoiding Recompilation of Some
- Files: Avoiding Compilation.
-
- * Conditional execution.
-
- This feature has been implemented numerous times in various
- versions of `make'; it seems a natural extension derived from the
- features of the C preprocessor and similar macro languages and is
- not a revolutionary concept. *Note Conditional Parts of
- Makefiles: Conditionals.
-
- * Specify a search path for included makefiles. *Note Including
- Other Makefiles: Include.
-
- * Specify extra makefiles to read with an environment variable.
- *Note The Variable `MAKEFILES': MAKEFILES Variable.
-
- * Strip leading sequences of `./' from file names, so that `./FILE'
- and `FILE' are considered to be the same file.
-
- * Use a special search method for library prerequisites written in
- the form `-lNAME'. *Note Directory Search for Link Libraries:
- Libraries/Search.
-
- * Allow suffixes for suffix rules (*note Old-Fashioned Suffix Rules:
- Suffix Rules.) to contain any characters. In other versions of
- `make', they must begin with `.' and not contain any `/'
- characters.
-
- * Keep track of the current level of `make' recursion using the
- variable `MAKELEVEL'. *Note Recursive Use of `make': Recursion.
-
- * Provide any goals given on the command line in the variable
- `MAKECMDGOALS'. *Note Arguments to Specify the Goals: Goals.
-
- * Specify static pattern rules. *Note Static Pattern Rules: Static
- Pattern.
-
- * Provide selective `vpath' search. *Note Searching Directories for
- Prerequisites: Directory Search.
-
- * Provide computed variable references. *Note Basics of Variable
- References: Reference.
-
- * Update makefiles. *Note How Makefiles Are Remade: Remaking
- Makefiles. System V `make' has a very, very limited form of this
- functionality in that it will check out SCCS files for makefiles.
-
- * Various new built-in implicit rules. *Note Catalogue of Implicit
- Rules: Catalogue of Rules.
-
- * The built-in variable `MAKE_VERSION' gives the version number of
- `make'.
-
-
-File: make.info, Node: Missing, Next: Makefile Conventions, Prev: Features, Up: Top
-
-13 Incompatibilities and Missing Features
-*****************************************
-
-The `make' programs in various other systems support a few features
-that are not implemented in GNU `make'. The POSIX.2 standard (`IEEE
-Standard 1003.2-1992') which specifies `make' does not require any of
-these features.
-
- * A target of the form `FILE((ENTRY))' stands for a member of
- archive file FILE. The member is chosen, not by name, but by
- being an object file which defines the linker symbol ENTRY.
-
- This feature was not put into GNU `make' because of the
- nonmodularity of putting knowledge into `make' of the internal
- format of archive file symbol tables. *Note Updating Archive
- Symbol Directories: Archive Symbols.
-
- * Suffixes (used in suffix rules) that end with the character `~'
- have a special meaning to System V `make'; they refer to the SCCS
- file that corresponds to the file one would get without the `~'.
- For example, the suffix rule `.c~.o' would make the file `N.o' from
- the SCCS file `s.N.c'. For complete coverage, a whole series of
- such suffix rules is required. *Note Old-Fashioned Suffix Rules:
- Suffix Rules.
-
- In GNU `make', this entire series of cases is handled by two
- pattern rules for extraction from SCCS, in combination with the
- general feature of rule chaining. *Note Chains of Implicit Rules:
- Chained Rules.
-
- * In System V and 4.3 BSD `make', files found by `VPATH' search
- (*note Searching Directories for Prerequisites: Directory Search.)
- have their names changed inside command strings. We feel it is
- much cleaner to always use automatic variables and thus make this
- feature obsolete.
-
- * In some Unix `make's, the automatic variable `$*' appearing in the
- prerequisites of a rule has the amazingly strange "feature" of
- expanding to the full name of the _target of that rule_. We cannot
- imagine what went on in the minds of Unix `make' developers to do
- this; it is utterly inconsistent with the normal definition of
- `$*'.
-
- * In some Unix `make's, implicit rule search (*note Using Implicit
- Rules: Implicit Rules.) is apparently done for _all_ targets, not
- just those without commands. This means you can do:
-
- foo.o:
- cc -c foo.c
-
- and Unix `make' will intuit that `foo.o' depends on `foo.c'.
-
- We feel that such usage is broken. The prerequisite properties of
- `make' are well-defined (for GNU `make', at least), and doing such
- a thing simply does not fit the model.
-
- * GNU `make' does not include any built-in implicit rules for
- compiling or preprocessing EFL programs. If we hear of anyone who
- is using EFL, we will gladly add them.
-
- * It appears that in SVR4 `make', a suffix rule can be specified with
- no commands, and it is treated as if it had empty commands (*note
- Empty Commands::). For example:
-
- .c.a:
-
- will override the built-in `.c.a' suffix rule.
-
- We feel that it is cleaner for a rule without commands to always
- simply add to the prerequisite list for the target. The above
- example can be easily rewritten to get the desired behavior in GNU
- `make':
-
- .c.a: ;
-
- * Some versions of `make' invoke the shell with the `-e' flag,
- except under `-k' (*note Testing the Compilation of a Program:
- Testing.). The `-e' flag tells the shell to exit as soon as any
- program it runs returns a nonzero status. We feel it is cleaner to
- write each shell command line to stand on its own and not require
- this special treatment.
-
-
-File: make.info, Node: Makefile Conventions, Next: Quick Reference, Prev: Missing, Up: Top
-
-14 Makefile Conventions
-***********************
-
-This node describes conventions for writing the Makefiles for GNU
-programs. Using Automake will help you write a Makefile that follows
-these conventions.
-
-* Menu:
-
-* Makefile Basics:: General Conventions for Makefiles
-* Utilities in Makefiles:: Utilities in Makefiles
-* Command Variables:: Variables for Specifying Commands
-* Directory Variables:: Variables for Installation Directories
-* Standard Targets:: Standard Targets for Users
-* Install Command Categories:: Three categories of commands in the `install'
- rule: normal, pre-install and post-install.
-
-
-File: make.info, Node: Makefile Basics, Next: Utilities in Makefiles, Up: Makefile Conventions
-
-14.1 General Conventions for Makefiles
-======================================
-
-Every Makefile should contain this line:
-
- SHELL = /bin/sh
-
-to avoid trouble on systems where the `SHELL' variable might be
-inherited from the environment. (This is never a problem with GNU
-`make'.)
-
- Different `make' programs have incompatible suffix lists and
-implicit rules, and this sometimes creates confusion or misbehavior. So
-it is a good idea to set the suffix list explicitly using only the
-suffixes you need in the particular Makefile, like this:
-
- .SUFFIXES:
- .SUFFIXES: .c .o
-
-The first line clears out the suffix list, the second introduces all
-suffixes which may be subject to implicit rules in this Makefile.
-
- Don't assume that `.' is in the path for command execution. When
-you need to run programs that are a part of your package during the
-make, please make sure that it uses `./' if the program is built as
-part of the make or `$(srcdir)/' if the file is an unchanging part of
-the source code. Without one of these prefixes, the current search
-path is used.
-
- The distinction between `./' (the "build directory") and
-`$(srcdir)/' (the "source directory") is important because users can
-build in a separate directory using the `--srcdir' option to
-`configure'. A rule of the form:
-
- foo.1 : foo.man sedscript
- sed -e sedscript foo.man > foo.1
-
-will fail when the build directory is not the source directory, because
-`foo.man' and `sedscript' are in the source directory.
-
- When using GNU `make', relying on `VPATH' to find the source file
-will work in the case where there is a single dependency file, since
-the `make' automatic variable `$<' will represent the source file
-wherever it is. (Many versions of `make' set `$<' only in implicit
-rules.) A Makefile target like
-
- foo.o : bar.c
- $(CC) -I. -I$(srcdir) $(CFLAGS) -c bar.c -o foo.o
-
-should instead be written as
-
- foo.o : bar.c
- $(CC) -I. -I$(srcdir) $(CFLAGS) -c $< -o $@
-
-in order to allow `VPATH' to work correctly. When the target has
-multiple dependencies, using an explicit `$(srcdir)' is the easiest way
-to make the rule work well. For example, the target above for `foo.1'
-is best written as:
-
- foo.1 : foo.man sedscript
- sed -e $(srcdir)/sedscript $(srcdir)/foo.man > $@
-
- GNU distributions usually contain some files which are not source
-files--for example, Info files, and the output from Autoconf, Automake,
-Bison or Flex. Since these files normally appear in the source
-directory, they should always appear in the source directory, not in the
-build directory. So Makefile rules to update them should put the
-updated files in the source directory.
-
- However, if a file does not appear in the distribution, then the
-Makefile should not put it in the source directory, because building a
-program in ordinary circumstances should not modify the source directory
-in any way.
-
- Try to make the build and installation targets, at least (and all
-their subtargets) work correctly with a parallel `make'.
-
-
-File: make.info, Node: Utilities in Makefiles, Next: Command Variables, Prev: Makefile Basics, Up: Makefile Conventions
-
-14.2 Utilities in Makefiles
-===========================
-
-Write the Makefile commands (and any shell scripts, such as
-`configure') to run in `sh', not in `csh'. Don't use any special
-features of `ksh' or `bash'.
-
- The `configure' script and the Makefile rules for building and
-installation should not use any utilities directly except these:
-
- cat cmp cp diff echo egrep expr false grep install-info
- ln ls mkdir mv pwd rm rmdir sed sleep sort tar test touch true
-
- The compression program `gzip' can be used in the `dist' rule.
-
- Stick to the generally supported options for these programs. For
-example, don't use `mkdir -p', convenient as it may be, because most
-systems don't support it.
-
- It is a good idea to avoid creating symbolic links in makefiles,
-since a few systems don't support them.
-
- The Makefile rules for building and installation can also use
-compilers and related programs, but should do so via `make' variables
-so that the user can substitute alternatives. Here are some of the
-programs we mean:
-
- ar bison cc flex install ld ldconfig lex
- make makeinfo ranlib texi2dvi yacc
-
- Use the following `make' variables to run those programs:
-
- $(AR) $(BISON) $(CC) $(FLEX) $(INSTALL) $(LD) $(LDCONFIG) $(LEX)
- $(MAKE) $(MAKEINFO) $(RANLIB) $(TEXI2DVI) $(YACC)
-
- When you use `ranlib' or `ldconfig', you should make sure nothing
-bad happens if the system does not have the program in question.
-Arrange to ignore an error from that command, and print a message before
-the command to tell the user that failure of this command does not mean
-a problem. (The Autoconf `AC_PROG_RANLIB' macro can help with this.)
-
- If you use symbolic links, you should implement a fallback for
-systems that don't have symbolic links.
-
- Additional utilities that can be used via Make variables are:
-
- chgrp chmod chown mknod
-
- It is ok to use other utilities in Makefile portions (or scripts)
-intended only for particular systems where you know those utilities
-exist.
-
-
-File: make.info, Node: Command Variables, Next: Directory Variables, Prev: Utilities in Makefiles, Up: Makefile Conventions
-
-14.3 Variables for Specifying Commands
-======================================
-
-Makefiles should provide variables for overriding certain commands,
-options, and so on.
-
- In particular, you should run most utility programs via variables.
-Thus, if you use Bison, have a variable named `BISON' whose default
-value is set with `BISON = bison', and refer to it with `$(BISON)'
-whenever you need to use Bison.
-
- File management utilities such as `ln', `rm', `mv', and so on, need
-not be referred to through variables in this way, since users don't
-need to replace them with other programs.
-
- Each program-name variable should come with an options variable that
-is used to supply options to the program. Append `FLAGS' to the
-program-name variable name to get the options variable name--for
-example, `BISONFLAGS'. (The names `CFLAGS' for the C compiler,
-`YFLAGS' for yacc, and `LFLAGS' for lex, are exceptions to this rule,
-but we keep them because they are standard.) Use `CPPFLAGS' in any
-compilation command that runs the preprocessor, and use `LDFLAGS' in
-any compilation command that does linking as well as in any direct use
-of `ld'.
-
- If there are C compiler options that _must_ be used for proper
-compilation of certain files, do not include them in `CFLAGS'. Users
-expect to be able to specify `CFLAGS' freely themselves. Instead,
-arrange to pass the necessary options to the C compiler independently
-of `CFLAGS', by writing them explicitly in the compilation commands or
-by defining an implicit rule, like this:
-
- CFLAGS = -g
- ALL_CFLAGS = -I. $(CFLAGS)
- .c.o:
- $(CC) -c $(CPPFLAGS) $(ALL_CFLAGS) $<
-
- Do include the `-g' option in `CFLAGS', because that is not
-_required_ for proper compilation. You can consider it a default that
-is only recommended. If the package is set up so that it is compiled
-with GCC by default, then you might as well include `-O' in the default
-value of `CFLAGS' as well.
-
- Put `CFLAGS' last in the compilation command, after other variables
-containing compiler options, so the user can use `CFLAGS' to override
-the others.
-
- `CFLAGS' should be used in every invocation of the C compiler, both
-those which do compilation and those which do linking.
-
- Every Makefile should define the variable `INSTALL', which is the
-basic command for installing a file into the system.
-
- Every Makefile should also define the variables `INSTALL_PROGRAM'
-and `INSTALL_DATA'. (The default for `INSTALL_PROGRAM' should be
-`$(INSTALL)'; the default for `INSTALL_DATA' should be `${INSTALL} -m
-644'.) Then it should use those variables as the commands for actual
-installation, for executables and nonexecutables respectively. Use
-these variables as follows:
-
- $(INSTALL_PROGRAM) foo $(bindir)/foo
- $(INSTALL_DATA) libfoo.a $(libdir)/libfoo.a
-
- Optionally, you may prepend the value of `DESTDIR' to the target
-filename. Doing this allows the installer to create a snapshot of the
-installation to be copied onto the real target filesystem later. Do not
-set the value of `DESTDIR' in your Makefile, and do not include it in
-any installed files. With support for `DESTDIR', the above examples
-become:
-
- $(INSTALL_PROGRAM) foo $(DESTDIR)$(bindir)/foo
- $(INSTALL_DATA) libfoo.a $(DESTDIR)$(libdir)/libfoo.a
-
-Always use a file name, not a directory name, as the second argument of
-the installation commands. Use a separate command for each file to be
-installed.
-
-
-File: make.info, Node: Directory Variables, Next: Standard Targets, Prev: Command Variables, Up: Makefile Conventions
-
-14.4 Variables for Installation Directories
-===========================================
-
-Installation directories should always be named by variables, so it is
-easy to install in a nonstandard place. The standard names for these
-variables and the values they should have in GNU packages are described
-below. They are based on a standard filesystem layout; variants of it
-are used in GNU/Linux and other modern operating systems.
-
- Installers are expected to override these values when calling `make'
-(e.g., `make prefix=/usr install' or `configure' (e.g., `configure
---prefix=/usr'). GNU packages should not try to guess which value
-should be appropriate for these variables on the system they are being
-installed onto: use the default settings specified here so that all GNU
-packages behave identically, allowing the installer to achieve any
-desired layout.
-
- These two variables set the root for the installation. All the other
-installation directories should be subdirectories of one of these two,
-and nothing should be directly installed into these two directories.
-
-`prefix'
- A prefix used in constructing the default values of the variables
- listed below. The default value of `prefix' should be
- `/usr/local'. When building the complete GNU system, the prefix
- will be empty and `/usr' will be a symbolic link to `/'. (If you
- are using Autoconf, write it as `@prefix@'.)
-
- Running `make install' with a different value of `prefix' from the
- one used to build the program should _not_ recompile the program.
-
-`exec_prefix'
- A prefix used in constructing the default values of some of the
- variables listed below. The default value of `exec_prefix' should
- be `$(prefix)'. (If you are using Autoconf, write it as
- `@exec_prefix@'.)
-
- Generally, `$(exec_prefix)' is used for directories that contain
- machine-specific files (such as executables and subroutine
- libraries), while `$(prefix)' is used directly for other
- directories.
-
- Running `make install' with a different value of `exec_prefix'
- from the one used to build the program should _not_ recompile the
- program.
-
- Executable programs are installed in one of the following
-directories.
-
-`bindir'
- The directory for installing executable programs that users can
- run. This should normally be `/usr/local/bin', but write it as
- `$(exec_prefix)/bin'. (If you are using Autoconf, write it as
- `@bindir@'.)
-
-`sbindir'
- The directory for installing executable programs that can be run
- from the shell, but are only generally useful to system
- administrators. This should normally be `/usr/local/sbin', but
- write it as `$(exec_prefix)/sbin'. (If you are using Autoconf,
- write it as `@sbindir@'.)
-
-`libexecdir'
- The directory for installing executable programs to be run by other
- programs rather than by users. This directory should normally be
- `/usr/local/libexec', but write it as `$(exec_prefix)/libexec'.
- (If you are using Autoconf, write it as `@libexecdir@'.)
-
- The definition of `libexecdir' is the same for all packages, so
- you should install your data in a subdirectory thereof. Most
- packages install their data under `$(libexecdir)/PACKAGE-NAME/',
- possibly within additional subdirectories thereof, such as
- `$(libexecdir)/PACKAGE-NAME/MACHINE/VERSION'.
-
- Data files used by the program during its execution are divided into
-categories in two ways.
-
- * Some files are normally modified by programs; others are never
- normally modified (though users may edit some of these).
-
- * Some files are architecture-independent and can be shared by all
- machines at a site; some are architecture-dependent and can be
- shared only by machines of the same kind and operating system;
- others may never be shared between two machines.
-
- This makes for six different possibilities. However, we want to
-discourage the use of architecture-dependent files, aside from object
-files and libraries. It is much cleaner to make other data files
-architecture-independent, and it is generally not hard.
-
- Here are the variables Makefiles should use to specify directories
-to put these various kinds of files in:
-
-`datarootdir'
- The root of the directory tree for read-only
- architecture-independent data files. This should normally be
- `/usr/local/share', but write it as `$(prefix)/share'. (If you
- are using Autoconf, write it as `@datarootdir@'.) `datadir''s
- default value is based on this variable; so are `infodir',
- `mandir', and others.
-
-`datadir'
- The directory for installing idiosyncratic read-only
- architecture-independent data files for this program. This is
- usually the same place as `datarootdir', but we use the two
- separate variables so that you can move these program-specific
- files without altering the location for Info files, man pages, etc.
-
- This should normally be `/usr/local/share', but write it as
- `$(datarootdir)'. (If you are using Autoconf, write it as
- `@datadir@'.)
-
- The definition of `datadir' is the same for all packages, so you
- should install your data in a subdirectory thereof. Most packages
- install their data under `$(datadir)/PACKAGE-NAME/'.
-
-`sysconfdir'
- The directory for installing read-only data files that pertain to a
- single machine-that is to say, files for configuring a host.
- Mailer and network configuration files, `/etc/passwd', and so
- forth belong here. All the files in this directory should be
- ordinary ASCII text files. This directory should normally be
- `/usr/local/etc', but write it as `$(prefix)/etc'. (If you are
- using Autoconf, write it as `@sysconfdir@'.)
-
- Do not install executables here in this directory (they probably
- belong in `$(libexecdir)' or `$(sbindir)'). Also do not install
- files that are modified in the normal course of their use (programs
- whose purpose is to change the configuration of the system
- excluded). Those probably belong in `$(localstatedir)'.
-
-`sharedstatedir'
- The directory for installing architecture-independent data files
- which the programs modify while they run. This should normally be
- `/usr/local/com', but write it as `$(prefix)/com'. (If you are
- using Autoconf, write it as `@sharedstatedir@'.)
-
-`localstatedir'
- The directory for installing data files which the programs modify
- while they run, and that pertain to one specific machine. Users
- should never need to modify files in this directory to configure
- the package's operation; put such configuration information in
- separate files that go in `$(datadir)' or `$(sysconfdir)'.
- `$(localstatedir)' should normally be `/usr/local/var', but write
- it as `$(prefix)/var'. (If you are using Autoconf, write it as
- `@localstatedir@'.)
-
- These variables specify the directory for installing certain specific
-types of files, if your program has them. Every GNU package should
-have Info files, so every program needs `infodir', but not all need
-`libdir' or `lispdir'.
-
-`includedir'
- The directory for installing header files to be included by user
- programs with the C `#include' preprocessor directive. This
- should normally be `/usr/local/include', but write it as
- `$(prefix)/include'. (If you are using Autoconf, write it as
- `@includedir@'.)
-
- Most compilers other than GCC do not look for header files in
- directory `/usr/local/include'. So installing the header files
- this way is only useful with GCC. Sometimes this is not a problem
- because some libraries are only really intended to work with GCC.
- But some libraries are intended to work with other compilers.
- They should install their header files in two places, one
- specified by `includedir' and one specified by `oldincludedir'.
-
-`oldincludedir'
- The directory for installing `#include' header files for use with
- compilers other than GCC. This should normally be `/usr/include'.
- (If you are using Autoconf, you can write it as `@oldincludedir@'.)
-
- The Makefile commands should check whether the value of
- `oldincludedir' is empty. If it is, they should not try to use
- it; they should cancel the second installation of the header files.
-
- A package should not replace an existing header in this directory
- unless the header came from the same package. Thus, if your Foo
- package provides a header file `foo.h', then it should install the
- header file in the `oldincludedir' directory if either (1) there
- is no `foo.h' there or (2) the `foo.h' that exists came from the
- Foo package.
-
- To tell whether `foo.h' came from the Foo package, put a magic
- string in the file--part of a comment--and `grep' for that string.
-
-`docdir'
- The directory for installing documentation files (other than Info)
- for this package. By default, it should be
- `/usr/local/share/doc/YOURPKG', but it should be written as
- `$(datarootdir)/doc/YOURPKG'. (If you are using Autoconf, write
- it as `@docdir@'.) The YOURPKG subdirectory, which may include a
- version number, prevents collisions among files with common names,
- such as `README'.
-
-`infodir'
- The directory for installing the Info files for this package. By
- default, it should be `/usr/local/share/info', but it should be
- written as `$(datarootdir)/info'. (If you are using Autoconf,
- write it as `@infodir@'.) `infodir' is separate from `docdir' for
- compatibility with existing practice.
-
-`htmldir'
-`dvidir'
-`pdfdir'
-`psdir'
- Directories for installing documentation files in the particular
- format. (It is not required to support documentation in all these
- formats.) They should all be set to `$(docdir)' by default. (If
- you are using Autoconf, write them as `@htmldir@', `@dvidir@',
- etc.) Packages which supply several translations of their
- documentation should install them in `$(htmldir)/'LL,
- `$(pdfdir)/'LL, etc. where LL is a locale abbreviation such as
- `en' or `pt_BR'.
-
-`libdir'
- The directory for object files and libraries of object code. Do
- not install executables here, they probably ought to go in
- `$(libexecdir)' instead. The value of `libdir' should normally be
- `/usr/local/lib', but write it as `$(exec_prefix)/lib'. (If you
- are using Autoconf, write it as `@libdir@'.)
-
-`lispdir'
- The directory for installing any Emacs Lisp files in this package.
- By default, it should be `/usr/local/share/emacs/site-lisp', but
- it should be written as `$(datarootdir)/emacs/site-lisp'.
-
- If you are using Autoconf, write the default as `@lispdir@'. In
- order to make `@lispdir@' work, you need the following lines in
- your `configure.in' file:
-
- lispdir='${datarootdir}/emacs/site-lisp'
- AC_SUBST(lispdir)
-
-`localedir'
- The directory for installing locale-specific message catalogs for
- this package. By default, it should be `/usr/local/share/locale',
- but it should be written as `$(datarootdir)/locale'. (If you are
- using Autoconf, write it as `@localedir@'.) This directory
- usually has a subdirectory per locale.
-
- Unix-style man pages are installed in one of the following:
-
-`mandir'
- The top-level directory for installing the man pages (if any) for
- this package. It will normally be `/usr/local/share/man', but you
- should write it as `$(datarootdir)/man'. (If you are using
- Autoconf, write it as `@mandir@'.)
-
-`man1dir'
- The directory for installing section 1 man pages. Write it as
- `$(mandir)/man1'.
-
-`man2dir'
- The directory for installing section 2 man pages. Write it as
- `$(mandir)/man2'
-
-`...'
- *Don't make the primary documentation for any GNU software be a
- man page. Write a manual in Texinfo instead. Man pages are just
- for the sake of people running GNU software on Unix, which is a
- secondary application only.*
-
-`manext'
- The file name extension for the installed man page. This should
- contain a period followed by the appropriate digit; it should
- normally be `.1'.
-
-`man1ext'
- The file name extension for installed section 1 man pages.
-
-`man2ext'
- The file name extension for installed section 2 man pages.
-
-`...'
- Use these names instead of `manext' if the package needs to
- install man pages in more than one section of the manual.
-
- And finally, you should set the following variable:
-
-`srcdir'
- The directory for the sources being compiled. The value of this
- variable is normally inserted by the `configure' shell script.
- (If you are using Autconf, use `srcdir = @srcdir@'.)
-
- For example:
-
- # Common prefix for installation directories.
- # NOTE: This directory must exist when you start the install.
- prefix = /usr/local
- datarootdir = $(prefix)/share
- datadir = $(datarootdir)
- exec_prefix = $(prefix)
- # Where to put the executable for the command `gcc'.
- bindir = $(exec_prefix)/bin
- # Where to put the directories used by the compiler.
- libexecdir = $(exec_prefix)/libexec
- # Where to put the Info files.
- infodir = $(datarootdir)/info
-
- If your program installs a large number of files into one of the
-standard user-specified directories, it might be useful to group them
-into a subdirectory particular to that program. If you do this, you
-should write the `install' rule to create these subdirectories.
-
- Do not expect the user to include the subdirectory name in the value
-of any of the variables listed above. The idea of having a uniform set
-of variable names for installation directories is to enable the user to
-specify the exact same values for several different GNU packages. In
-order for this to be useful, all the packages must be designed so that
-they will work sensibly when the user does so.
-
-
-File: make.info, Node: Standard Targets, Next: Install Command Categories, Prev: Directory Variables, Up: Makefile Conventions
-
-14.5 Standard Targets for Users
-===============================
-
-All GNU programs should have the following targets in their Makefiles:
-
-`all'
- Compile the entire program. This should be the default target.
- This target need not rebuild any documentation files; Info files
- should normally be included in the distribution, and DVI files
- should be made only when explicitly asked for.
-
- By default, the Make rules should compile and link with `-g', so
- that executable programs have debugging symbols. Users who don't
- mind being helpless can strip the executables later if they wish.
-
-`install'
- Compile the program and copy the executables, libraries, and so on
- to the file names where they should reside for actual use. If
- there is a simple test to verify that a program is properly
- installed, this target should run that test.
-
- Do not strip executables when installing them. Devil-may-care
- users can use the `install-strip' target to do that.
-
- If possible, write the `install' target rule so that it does not
- modify anything in the directory where the program was built,
- provided `make all' has just been done. This is convenient for
- building the program under one user name and installing it under
- another.
-
- The commands should create all the directories in which files are
- to be installed, if they don't already exist. This includes the
- directories specified as the values of the variables `prefix' and
- `exec_prefix', as well as all subdirectories that are needed. One
- way to do this is by means of an `installdirs' target as described
- below.
-
- Use `-' before any command for installing a man page, so that
- `make' will ignore any errors. This is in case there are systems
- that don't have the Unix man page documentation system installed.
-
- The way to install Info files is to copy them into `$(infodir)'
- with `$(INSTALL_DATA)' (*note Command Variables::), and then run
- the `install-info' program if it is present. `install-info' is a
- program that edits the Info `dir' file to add or update the menu
- entry for the given Info file; it is part of the Texinfo package.
- Here is a sample rule to install an Info file:
-
- $(DESTDIR)$(infodir)/foo.info: foo.info
- $(POST_INSTALL)
- # There may be a newer info file in . than in srcdir.
- -if test -f foo.info; then d=.; \
- else d=$(srcdir); fi; \
- $(INSTALL_DATA) $$d/foo.info $(DESTDIR)$@; \
- # Run install-info only if it exists.
- # Use `if' instead of just prepending `-' to the
- # line so we notice real errors from install-info.
- # We use `$(SHELL) -c' because some shells do not
- # fail gracefully when there is an unknown command.
- if $(SHELL) -c 'install-info --version' \
- >/dev/null 2>&1; then \
- install-info --dir-file=$(DESTDIR)$(infodir)/dir \
- $(DESTDIR)$(infodir)/foo.info; \
- else true; fi
-
- When writing the `install' target, you must classify all the
- commands into three categories: normal ones, "pre-installation"
- commands and "post-installation" commands. *Note Install Command
- Categories::.
-
-`install-html'
-`install-dvi'
-`install-pdf'
-`install-ps'
- These targets install documentation in formats other than Info;
- they're intended to be called explicitly by the person installing
- the package, if that format is desired. GNU prefers Info files,
- so these must be installed by the `install' target.
-
- When you have many documentation files to install, we recommend
- that you avoid collisions and clutter by arranging for these
- targets to install in subdirectories of the appropriate
- installation directory, such as `htmldir'. As one example, if
- your package has multiple manuals, and you wish to install HTML
- documentation with many files (such as the "split" mode output by
- `makeinfo --html'), you'll certainly want to use subdirectories,
- or two nodes with the same name in different manuals will
- overwrite each other.
-
-`uninstall'
- Delete all the installed files--the copies that the `install' and
- `install-*' targets create.
-
- This rule should not modify the directories where compilation is
- done, only the directories where files are installed.
-
- The uninstallation commands are divided into three categories,
- just like the installation commands. *Note Install Command
- Categories::.
-
-`install-strip'
- Like `install', but strip the executable files while installing
- them. In simple cases, this target can use the `install' target in
- a simple way:
-
- install-strip:
- $(MAKE) INSTALL_PROGRAM='$(INSTALL_PROGRAM) -s' \
- install
-
- But if the package installs scripts as well as real executables,
- the `install-strip' target can't just refer to the `install'
- target; it has to strip the executables but not the scripts.
-
- `install-strip' should not strip the executables in the build
- directory which are being copied for installation. It should only
- strip the copies that are installed.
-
- Normally we do not recommend stripping an executable unless you
- are sure the program has no bugs. However, it can be reasonable
- to install a stripped executable for actual execution while saving
- the unstripped executable elsewhere in case there is a bug.
-
-`clean'
- Delete all files in the current directory that are normally
- created by building the program. Also delete files in other
- directories if they are created by this makefile. However, don't
- delete the files that record the configuration. Also preserve
- files that could be made by building, but normally aren't because
- the distribution comes with them. There is no need to delete
- parent directories that were created with `mkdir -p', since they
- could have existed anyway.
-
- Delete `.dvi' files here if they are not part of the distribution.
-
-`distclean'
- Delete all files in the current directory (or created by this
- makefile) that are created by configuring or building the program.
- If you have unpacked the source and built the program without
- creating any other files, `make distclean' should leave only the
- files that were in the distribution. However, there is no need to
- delete parent directories that were created with `mkdir -p', since
- they could have existed anyway.
-
-`mostlyclean'
- Like `clean', but may refrain from deleting a few files that people
- normally don't want to recompile. For example, the `mostlyclean'
- target for GCC does not delete `libgcc.a', because recompiling it
- is rarely necessary and takes a lot of time.
-
-`maintainer-clean'
- Delete almost everything that can be reconstructed with this
- Makefile. This typically includes everything deleted by
- `distclean', plus more: C source files produced by Bison, tags
- tables, Info files, and so on.
-
- The reason we say "almost everything" is that running the command
- `make maintainer-clean' should not delete `configure' even if
- `configure' can be remade using a rule in the Makefile. More
- generally, `make maintainer-clean' should not delete anything that
- needs to exist in order to run `configure' and then begin to build
- the program. Also, there is no need to delete parent directories
- that were created with `mkdir -p', since they could have existed
- anyway. These are the only exceptions; `maintainer-clean' should
- delete everything else that can be rebuilt.
-
- The `maintainer-clean' target is intended to be used by a
- maintainer of the package, not by ordinary users. You may need
- special tools to reconstruct some of the files that `make
- maintainer-clean' deletes. Since these files are normally
- included in the distribution, we don't take care to make them easy
- to reconstruct. If you find you need to unpack the full
- distribution again, don't blame us.
-
- To help make users aware of this, the commands for the special
- `maintainer-clean' target should start with these two:
-
- @echo 'This command is intended for maintainers to use; it'
- @echo 'deletes files that may need special tools to rebuild.'
-
-`TAGS'
- Update a tags table for this program.
-
-`info'
- Generate any Info files needed. The best way to write the rules
- is as follows:
-
- info: foo.info
-
- foo.info: foo.texi chap1.texi chap2.texi
- $(MAKEINFO) $(srcdir)/foo.texi
-
- You must define the variable `MAKEINFO' in the Makefile. It should
- run the `makeinfo' program, which is part of the Texinfo
- distribution.
-
- Normally a GNU distribution comes with Info files, and that means
- the Info files are present in the source directory. Therefore,
- the Make rule for an info file should update it in the source
- directory. When users build the package, ordinarily Make will not
- update the Info files because they will already be up to date.
-
-`dvi'
-`html'
-`pdf'
-`ps'
- Generate documentation files in the given format, if possible.
- Here's an example rule for generating DVI files from Texinfo:
-
- dvi: foo.dvi
-
- foo.dvi: foo.texi chap1.texi chap2.texi
- $(TEXI2DVI) $(srcdir)/foo.texi
-
- You must define the variable `TEXI2DVI' in the Makefile. It should
- run the program `texi2dvi', which is part of the Texinfo
- distribution.(1) Alternatively, write just the dependencies, and
- allow GNU `make' to provide the command.
-
- Here's another example, this one for generating HTML from Texinfo:
-
- html: foo.html
-
- foo.html: foo.texi chap1.texi chap2.texi
- $(TEXI2HTML) $(srcdir)/foo.texi
-
- Again, you would define the variable `TEXI2HTML' in the Makefile;
- for example, it might run `makeinfo --no-split --html' (`makeinfo'
- is part of the Texinfo distribution).
-
-`dist'
- Create a distribution tar file for this program. The tar file
- should be set up so that the file names in the tar file start with
- a subdirectory name which is the name of the package it is a
- distribution for. This name can include the version number.
-
- For example, the distribution tar file of GCC version 1.40 unpacks
- into a subdirectory named `gcc-1.40'.
-
- The easiest way to do this is to create a subdirectory
- appropriately named, use `ln' or `cp' to install the proper files
- in it, and then `tar' that subdirectory.
-
- Compress the tar file with `gzip'. For example, the actual
- distribution file for GCC version 1.40 is called `gcc-1.40.tar.gz'.
-
- The `dist' target should explicitly depend on all non-source files
- that are in the distribution, to make sure they are up to date in
- the distribution. *Note Making Releases: (standards)Releases.
-
-`check'
- Perform self-tests (if any). The user must build the program
- before running the tests, but need not install the program; you
- should write the self-tests so that they work when the program is
- built but not installed.
-
- The following targets are suggested as conventional names, for
-programs in which they are useful.
-
-`installcheck'
- Perform installation tests (if any). The user must build and
- install the program before running the tests. You should not
- assume that `$(bindir)' is in the search path.
-
-`installdirs'
- It's useful to add a target named `installdirs' to create the
- directories where files are installed, and their parent
- directories. There is a script called `mkinstalldirs' which is
- convenient for this; you can find it in the Texinfo package. You
- can use a rule like this:
-
- # Make sure all installation directories (e.g. $(bindir))
- # actually exist by making them if necessary.
- installdirs: mkinstalldirs
- $(srcdir)/mkinstalldirs $(bindir) $(datadir) \
- $(libdir) $(infodir) \
- $(mandir)
-
- or, if you wish to support `DESTDIR',
-
- # Make sure all installation directories (e.g. $(bindir))
- # actually exist by making them if necessary.
- installdirs: mkinstalldirs
- $(srcdir)/mkinstalldirs \
- $(DESTDIR)$(bindir) $(DESTDIR)$(datadir) \
- $(DESTDIR)$(libdir) $(DESTDIR)$(infodir) \
- $(DESTDIR)$(mandir)
-
- This rule should not modify the directories where compilation is
- done. It should do nothing but create installation directories.
-
- ---------- Footnotes ----------
-
- (1) `texi2dvi' uses TeX to do the real work of formatting. TeX is
-not distributed with Texinfo.
-
-
-File: make.info, Node: Install Command Categories, Prev: Standard Targets, Up: Makefile Conventions
-
-14.6 Install Command Categories
-===============================
-
-When writing the `install' target, you must classify all the commands
-into three categories: normal ones, "pre-installation" commands and
-"post-installation" commands.
-
- Normal commands move files into their proper places, and set their
-modes. They may not alter any files except the ones that come entirely
-from the package they belong to.
-
- Pre-installation and post-installation commands may alter other
-files; in particular, they can edit global configuration files or data
-bases.
-
- Pre-installation commands are typically executed before the normal
-commands, and post-installation commands are typically run after the
-normal commands.
-
- The most common use for a post-installation command is to run
-`install-info'. This cannot be done with a normal command, since it
-alters a file (the Info directory) which does not come entirely and
-solely from the package being installed. It is a post-installation
-command because it needs to be done after the normal command which
-installs the package's Info files.
-
- Most programs don't need any pre-installation commands, but we have
-the feature just in case it is needed.
-
- To classify the commands in the `install' rule into these three
-categories, insert "category lines" among them. A category line
-specifies the category for the commands that follow.
-
- A category line consists of a tab and a reference to a special Make
-variable, plus an optional comment at the end. There are three
-variables you can use, one for each category; the variable name
-specifies the category. Category lines are no-ops in ordinary execution
-because these three Make variables are normally undefined (and you
-_should not_ define them in the makefile).
-
- Here are the three possible category lines, each with a comment that
-explains what it means:
-
- $(PRE_INSTALL) # Pre-install commands follow.
- $(POST_INSTALL) # Post-install commands follow.
- $(NORMAL_INSTALL) # Normal commands follow.
-
- If you don't use a category line at the beginning of the `install'
-rule, all the commands are classified as normal until the first category
-line. If you don't use any category lines, all the commands are
-classified as normal.
-
- These are the category lines for `uninstall':
-
- $(PRE_UNINSTALL) # Pre-uninstall commands follow.
- $(POST_UNINSTALL) # Post-uninstall commands follow.
- $(NORMAL_UNINSTALL) # Normal commands follow.
-
- Typically, a pre-uninstall command would be used for deleting entries
-from the Info directory.
-
- If the `install' or `uninstall' target has any dependencies which
-act as subroutines of installation, then you should start _each_
-dependency's commands with a category line, and start the main target's
-commands with a category line also. This way, you can ensure that each
-command is placed in the right category regardless of which of the
-dependencies actually run.
-
- Pre-installation and post-installation commands should not run any
-programs except for these:
-
- [ basename bash cat chgrp chmod chown cmp cp dd diff echo
- egrep expand expr false fgrep find getopt grep gunzip gzip
- hostname install install-info kill ldconfig ln ls md5sum
- mkdir mkfifo mknod mv printenv pwd rm rmdir sed sort tee
- test touch true uname xargs yes
-
- The reason for distinguishing the commands in this way is for the
-sake of making binary packages. Typically a binary package contains
-all the executables and other files that need to be installed, and has
-its own method of installing them--so it does not need to run the normal
-installation commands. But installing the binary package does need to
-execute the pre-installation and post-installation commands.
-
- Programs to build binary packages work by extracting the
-pre-installation and post-installation commands. Here is one way of
-extracting the pre-installation commands (the `-s' option to `make' is
-needed to silence messages about entering subdirectories):
-
- make -s -n install -o all \
- PRE_INSTALL=pre-install \
- POST_INSTALL=post-install \
- NORMAL_INSTALL=normal-install \
- | gawk -f pre-install.awk
-
-where the file `pre-install.awk' could contain this:
-
- $0 ~ /^(normal-install|post-install)[ \t]*$/ {on = 0}
- on {print $0}
- $0 ~ /^pre-install[ \t]*$/ {on = 1}
-
-
-File: make.info, Node: Quick Reference, Next: Error Messages, Prev: Makefile Conventions, Up: Top
-
-Appendix A Quick Reference
-**************************
-
-This appendix summarizes the directives, text manipulation functions,
-and special variables which GNU `make' understands. *Note Special
-Targets::, *Note Catalogue of Implicit Rules: Catalogue of Rules, and
-*Note Summary of Options: Options Summary, for other summaries.
-
- Here is a summary of the directives GNU `make' recognizes:
-
-`define VARIABLE'
-`endef'
- Define a multi-line, recursively-expanded variable.
- *Note Sequences::.
-
-`ifdef VARIABLE'
-`ifndef VARIABLE'
-`ifeq (A,B)'
-`ifeq "A" "B"'
-`ifeq 'A' 'B''
-`ifneq (A,B)'
-`ifneq "A" "B"'
-`ifneq 'A' 'B''
-`else'
-`endif'
- Conditionally evaluate part of the makefile.
- *Note Conditionals::.
-
-`include FILE'
-`-include FILE'
-`sinclude FILE'
- Include another makefile.
- *Note Including Other Makefiles: Include.
-
-`override VARIABLE = VALUE'
-`override VARIABLE := VALUE'
-`override VARIABLE += VALUE'
-`override VARIABLE ?= VALUE'
-`override define VARIABLE'
-`endef'
- Define a variable, overriding any previous definition, even one
- from the command line.
- *Note The `override' Directive: Override Directive.
-
-`export'
- Tell `make' to export all variables to child processes by default.
- *Note Communicating Variables to a Sub-`make': Variables/Recursion.
-
-`export VARIABLE'
-`export VARIABLE = VALUE'
-`export VARIABLE := VALUE'
-`export VARIABLE += VALUE'
-`export VARIABLE ?= VALUE'
-`unexport VARIABLE'
- Tell `make' whether or not to export a particular variable to child
- processes.
- *Note Communicating Variables to a Sub-`make': Variables/Recursion.
-
-`vpath PATTERN PATH'
- Specify a search path for files matching a `%' pattern.
- *Note The `vpath' Directive: Selective Search.
-
-`vpath PATTERN'
- Remove all search paths previously specified for PATTERN.
-
-`vpath'
- Remove all search paths previously specified in any `vpath'
- directive.
-
- Here is a summary of the built-in functions (*note Functions::):
-
-`$(subst FROM,TO,TEXT)'
- Replace FROM with TO in TEXT.
- *Note Functions for String Substitution and Analysis: Text
- Functions.
-
-`$(patsubst PATTERN,REPLACEMENT,TEXT)'
- Replace words matching PATTERN with REPLACEMENT in TEXT.
- *Note Functions for String Substitution and Analysis: Text
- Functions.
-
-`$(strip STRING)'
- Remove excess whitespace characters from STRING.
- *Note Functions for String Substitution and Analysis: Text
- Functions.
-
-`$(findstring FIND,TEXT)'
- Locate FIND in TEXT.
- *Note Functions for String Substitution and Analysis: Text
- Functions.
-
-`$(filter PATTERN...,TEXT)'
- Select words in TEXT that match one of the PATTERN words.
- *Note Functions for String Substitution and Analysis: Text
- Functions.
-
-`$(filter-out PATTERN...,TEXT)'
- Select words in TEXT that _do not_ match any of the PATTERN words.
- *Note Functions for String Substitution and Analysis: Text
- Functions.
-
-`$(sort LIST)'
- Sort the words in LIST lexicographically, removing duplicates.
- *Note Functions for String Substitution and Analysis: Text
- Functions.
-
-`$(word N,TEXT)'
- Extract the Nth word (one-origin) of TEXT.
- *Note Functions for String Substitution and Analysis: Text
- Functions.
-
-`$(words TEXT)'
- Count the number of words in TEXT.
- *Note Functions for String Substitution and Analysis: Text
- Functions.
-
-`$(wordlist S,E,TEXT)'
- Returns the list of words in TEXT from S to E.
- *Note Functions for String Substitution and Analysis: Text
- Functions.
-
-`$(firstword NAMES...)'
- Extract the first word of NAMES.
- *Note Functions for String Substitution and Analysis: Text
- Functions.
-
-`$(lastword NAMES...)'
- Extract the last word of NAMES.
- *Note Functions for String Substitution and Analysis: Text
- Functions.
-
-`$(dir NAMES...)'
- Extract the directory part of each file name.
- *Note Functions for File Names: File Name Functions.
-
-`$(notdir NAMES...)'
- Extract the non-directory part of each file name.
- *Note Functions for File Names: File Name Functions.
-
-`$(suffix NAMES...)'
- Extract the suffix (the last `.' and following characters) of each
- file name.
- *Note Functions for File Names: File Name Functions.
-
-`$(basename NAMES...)'
- Extract the base name (name without suffix) of each file name.
- *Note Functions for File Names: File Name Functions.
-
-`$(addsuffix SUFFIX,NAMES...)'
- Append SUFFIX to each word in NAMES.
- *Note Functions for File Names: File Name Functions.
-
-`$(addprefix PREFIX,NAMES...)'
- Prepend PREFIX to each word in NAMES.
- *Note Functions for File Names: File Name Functions.
-
-`$(join LIST1,LIST2)'
- Join two parallel lists of words.
- *Note Functions for File Names: File Name Functions.
-
-`$(wildcard PATTERN...)'
- Find file names matching a shell file name pattern (_not_ a `%'
- pattern).
- *Note The Function `wildcard': Wildcard Function.
-
-`$(realpath NAMES...)'
- For each file name in NAMES, expand to an absolute name that does
- not contain any `.', `..', nor symlinks.
- *Note Functions for File Names: File Name Functions.
-
-`$(abspath NAMES...)'
- For each file name in NAMES, expand to an absolute name that does
- not contain any `.' or `..' components, but preserves symlinks.
- *Note Functions for File Names: File Name Functions.
-
-`$(error TEXT...)'
- When this function is evaluated, `make' generates a fatal error
- with the message TEXT.
- *Note Functions That Control Make: Make Control Functions.
-
-`$(warning TEXT...)'
- When this function is evaluated, `make' generates a warning with
- the message TEXT.
- *Note Functions That Control Make: Make Control Functions.
-
-`$(shell COMMAND)'
- Execute a shell command and return its output.
- *Note The `shell' Function: Shell Function.
-
-`$(origin VARIABLE)'
- Return a string describing how the `make' variable VARIABLE was
- defined.
- *Note The `origin' Function: Origin Function.
-
-`$(flavor VARIABLE)'
- Return a string describing the flavor of the `make' variable
- VARIABLE.
- *Note The `flavor' Function: Flavor Function.
-
-`$(foreach VAR,WORDS,TEXT)'
- Evaluate TEXT with VAR bound to each word in WORDS, and
- concatenate the results.
- *Note The `foreach' Function: Foreach Function.
-
-`$(call VAR,PARAM,...)'
- Evaluate the variable VAR replacing any references to `$(1)',
- `$(2)' with the first, second, etc. PARAM values.
- *Note The `call' Function: Call Function.
-
-`$(eval TEXT)'
- Evaluate TEXT then read the results as makefile commands. Expands
- to the empty string.
- *Note The `eval' Function: Eval Function.
-
-`$(value VAR)'
- Evaluates to the contents of the variable VAR, with no expansion
- performed on it.
- *Note The `value' Function: Value Function.
-
- Here is a summary of the automatic variables. *Note Automatic
-Variables::, for full information.
-
-`$@'
- The file name of the target.
-
-`$%'
- The target member name, when the target is an archive member.
-
-`$<'
- The name of the first prerequisite.
-
-`$?'
- The names of all the prerequisites that are newer than the target,
- with spaces between them. For prerequisites which are archive
- members, only the member named is used (*note Archives::).
-
-`$^'
-`$+'
- The names of all the prerequisites, with spaces between them. For
- prerequisites which are archive members, only the member named is
- used (*note Archives::). The value of `$^' omits duplicate
- prerequisites, while `$+' retains them and preserves their order.
-
-`$*'
- The stem with which an implicit rule matches (*note How Patterns
- Match: Pattern Match.).
-
-`$(@D)'
-`$(@F)'
- The directory part and the file-within-directory part of `$@'.
-
-`$(*D)'
-`$(*F)'
- The directory part and the file-within-directory part of `$*'.
-
-`$(%D)'
-`$(%F)'
- The directory part and the file-within-directory part of `$%'.
-
-`$(<D)'
-`$(<F)'
- The directory part and the file-within-directory part of `$<'.
-
-`$(^D)'
-`$(^F)'
- The directory part and the file-within-directory part of `$^'.
-
-`$(+D)'
-`$(+F)'
- The directory part and the file-within-directory part of `$+'.
-
-`$(?D)'
-`$(?F)'
- The directory part and the file-within-directory part of `$?'.
-
- These variables are used specially by GNU `make':
-
-`MAKEFILES'
- Makefiles to be read on every invocation of `make'.
- *Note The Variable `MAKEFILES': MAKEFILES Variable.
-
-`VPATH'
- Directory search path for files not found in the current directory.
- *Note `VPATH' Search Path for All Prerequisites: General Search.
-
-`SHELL'
- The name of the system default command interpreter, usually
- `/bin/sh'. You can set `SHELL' in the makefile to change the
- shell used to run commands. *Note Command Execution: Execution.
- The `SHELL' variable is handled specially when importing from and
- exporting to the environment. *Note Choosing the Shell::.
-
-`MAKESHELL'
- On MS-DOS only, the name of the command interpreter that is to be
- used by `make'. This value takes precedence over the value of
- `SHELL'. *Note MAKESHELL variable: Execution.
-
-`MAKE'
- The name with which `make' was invoked. Using this variable in
- commands has special meaning. *Note How the `MAKE' Variable
- Works: MAKE Variable.
-
-`MAKELEVEL'
- The number of levels of recursion (sub-`make's).
- *Note Variables/Recursion::.
-
-`MAKEFLAGS'
- The flags given to `make'. You can set this in the environment or
- a makefile to set flags.
- *Note Communicating Options to a Sub-`make': Options/Recursion.
-
- It is _never_ appropriate to use `MAKEFLAGS' directly on a command
- line: its contents may not be quoted correctly for use in the
- shell. Always allow recursive `make''s to obtain these values
- through the environment from its parent.
-
-`MAKECMDGOALS'
- The targets given to `make' on the command line. Setting this
- variable has no effect on the operation of `make'.
- *Note Arguments to Specify the Goals: Goals.
-
-`CURDIR'
- Set to the pathname of the current working directory (after all
- `-C' options are processed, if any). Setting this variable has no
- effect on the operation of `make'.
- *Note Recursive Use of `make': Recursion.
-
-`SUFFIXES'
- The default list of suffixes before `make' reads any makefiles.
-
-`.LIBPATTERNS'
- Defines the naming of the libraries `make' searches for, and their
- order.
- *Note Directory Search for Link Libraries: Libraries/Search.
-
-
-File: make.info, Node: Error Messages, Next: Complex Makefile, Prev: Quick Reference, Up: Top
-
-Appendix B Errors Generated by Make
-***********************************
-
-Here is a list of the more common errors you might see generated by
-`make', and some information about what they mean and how to fix them.
-
- Sometimes `make' errors are not fatal, especially in the presence of
-a `-' prefix on a command script line, or the `-k' command line option.
-Errors that are fatal are prefixed with the string `***'.
-
- Error messages are all either prefixed with the name of the program
-(usually `make'), or, if the error is found in a makefile, the name of
-the file and linenumber containing the problem.
-
- In the table below, these common prefixes are left off.
-
-`[FOO] Error NN'
-`[FOO] SIGNAL DESCRIPTION'
- These errors are not really `make' errors at all. They mean that a
- program that `make' invoked as part of a command script returned a
- non-0 error code (`Error NN'), which `make' interprets as failure,
- or it exited in some other abnormal fashion (with a signal of some
- type). *Note Errors in Commands: Errors.
-
- If no `***' is attached to the message, then the subprocess failed
- but the rule in the makefile was prefixed with the `-' special
- character, so `make' ignored the error.
-
-`missing separator. Stop.'
-`missing separator (did you mean TAB instead of 8 spaces?). Stop.'
- This means that `make' could not understand much of anything about
- the command line it just read. GNU `make' looks for various kinds
- of separators (`:', `=', TAB characters, etc.) to help it decide
- what kind of commandline it's seeing. This means it couldn't find
- a valid one.
-
- One of the most common reasons for this message is that you (or
- perhaps your oh-so-helpful editor, as is the case with many
- MS-Windows editors) have attempted to indent your command scripts
- with spaces instead of a TAB character. In this case, `make' will
- use the second form of the error above. Remember that every line
- in the command script must begin with a TAB character. Eight
- spaces do not count. *Note Rule Syntax::.
-
-`commands commence before first target. Stop.'
-`missing rule before commands. Stop.'
- This means the first thing in the makefile seems to be part of a
- command script: it begins with a TAB character and doesn't appear
- to be a legal `make' command (such as a variable assignment).
- Command scripts must always be associated with a target.
-
- The second form is generated if the line has a semicolon as the
- first non-whitespace character; `make' interprets this to mean you
- left out the "target: prerequisite" section of a rule. *Note Rule
- Syntax::.
-
-`No rule to make target `XXX'.'
-`No rule to make target `XXX', needed by `YYY'.'
- This means that `make' decided it needed to build a target, but
- then couldn't find any instructions in the makefile on how to do
- that, either explicit or implicit (including in the default rules
- database).
-
- If you want that file to be built, you will need to add a rule to
- your makefile describing how that target can be built. Other
- possible sources of this problem are typos in the makefile (if
- that filename is wrong) or a corrupted source tree (if that file
- is not supposed to be built, but rather only a prerequisite).
-
-`No targets specified and no makefile found. Stop.'
-`No targets. Stop.'
- The former means that you didn't provide any targets to be built
- on the command line, and `make' couldn't find any makefiles to
- read in. The latter means that some makefile was found, but it
- didn't contain any default goal and none was given on the command
- line. GNU `make' has nothing to do in these situations. *Note
- Arguments to Specify the Makefile: Makefile Arguments.
-
-`Makefile `XXX' was not found.'
-`Included makefile `XXX' was not found.'
- A makefile specified on the command line (first form) or included
- (second form) was not found.
-
-`warning: overriding commands for target `XXX''
-`warning: ignoring old commands for target `XXX''
- GNU `make' allows commands to be specified only once per target
- (except for double-colon rules). If you give commands for a target
- which already has been defined to have commands, this warning is
- issued and the second set of commands will overwrite the first set.
- *Note Multiple Rules for One Target: Multiple Rules.
-
-`Circular XXX <- YYY dependency dropped.'
- This means that `make' detected a loop in the dependency graph:
- after tracing the prerequisite YYY of target XXX, and its
- prerequisites, etc., one of them depended on XXX again.
-
-`Recursive variable `XXX' references itself (eventually). Stop.'
- This means you've defined a normal (recursive) `make' variable XXX
- that, when it's expanded, will refer to itself (XXX). This is not
- allowed; either use simply-expanded variables (`:=') or use the
- append operator (`+='). *Note How to Use Variables: Using
- Variables.
-
-`Unterminated variable reference. Stop.'
- This means you forgot to provide the proper closing parenthesis or
- brace in your variable or function reference.
-
-`insufficient arguments to function `XXX'. Stop.'
- This means you haven't provided the requisite number of arguments
- for this function. See the documentation of the function for a
- description of its arguments. *Note Functions for Transforming
- Text: Functions.
-
-`missing target pattern. Stop.'
-`multiple target patterns. Stop.'
-`target pattern contains no `%'. Stop.'
-`mixed implicit and static pattern rules. Stop.'
- These are generated for malformed static pattern rules. The first
- means there's no pattern in the target section of the rule; the
- second means there are multiple patterns in the target section;
- the third means the target doesn't contain a pattern character
- (`%'); and the fourth means that all three parts of the static
- pattern rule contain pattern characters (`%')-only the first two
- parts should. *Note Syntax of Static Pattern Rules: Static Usage.
-
-`warning: -jN forced in submake: disabling jobserver mode.'
- This warning and the next are generated if `make' detects error
- conditions related to parallel processing on systems where
- sub-`make's can communicate (*note Communicating Options to a
- Sub-`make': Options/Recursion.). This warning is generated if a
- recursive invocation of a `make' process is forced to have `-jN'
- in its argument list (where N is greater than one). This could
- happen, for example, if you set the `MAKE' environment variable to
- `make -j2'. In this case, the sub-`make' doesn't communicate with
- other `make' processes and will simply pretend it has two jobs of
- its own.
-
-`warning: jobserver unavailable: using -j1. Add `+' to parent make rule.'
- In order for `make' processes to communicate, the parent will pass
- information to the child. Since this could result in problems if
- the child process isn't actually a `make', the parent will only do
- this if it thinks the child is a `make'. The parent uses the
- normal algorithms to determine this (*note How the `MAKE' Variable
- Works: MAKE Variable.). If the makefile is constructed such that
- the parent doesn't know the child is a `make' process, then the
- child will receive only part of the information necessary. In
- this case, the child will generate this warning message and
- proceed with its build in a sequential manner.
-
-
-
-File: make.info, Node: Complex Makefile, Next: GNU Free Documentation License, Prev: Error Messages, Up: Top
-
-Appendix C Complex Makefile Example
-***********************************
-
-Here is the makefile for the GNU `tar' program. This is a moderately
-complex makefile.
-
- Because it is the first target, the default goal is `all'. An
-interesting feature of this makefile is that `testpad.h' is a source
-file automatically created by the `testpad' program, itself compiled
-from `testpad.c'.
-
- If you type `make' or `make all', then `make' creates the `tar'
-executable, the `rmt' daemon that provides remote tape access, and the
-`tar.info' Info file.
-
- If you type `make install', then `make' not only creates `tar',
-`rmt', and `tar.info', but also installs them.
-
- If you type `make clean', then `make' removes the `.o' files, and
-the `tar', `rmt', `testpad', `testpad.h', and `core' files.
-
- If you type `make distclean', then `make' not only removes the same
-files as does `make clean' but also the `TAGS', `Makefile', and
-`config.status' files. (Although it is not evident, this makefile (and
-`config.status') is generated by the user with the `configure' program,
-which is provided in the `tar' distribution, but is not shown here.)
-
- If you type `make realclean', then `make' removes the same files as
-does `make distclean' and also removes the Info files generated from
-`tar.texinfo'.
-
- In addition, there are targets `shar' and `dist' that create
-distribution kits.
-
- # Generated automatically from Makefile.in by configure.
- # Un*x Makefile for GNU tar program.
- # Copyright (C) 1991 Free Software Foundation, Inc.
-
- # This program is free software; you can redistribute
- # it and/or modify it under the terms of the GNU
- # General Public License ...
- ...
- ...
-
- SHELL = /bin/sh
-
- #### Start of system configuration section. ####
-
- srcdir = .
-
- # If you use gcc, you should either run the
- # fixincludes script that comes with it or else use
- # gcc with the -traditional option. Otherwise ioctl
- # calls will be compiled incorrectly on some systems.
- CC = gcc -O
- YACC = bison -y
- INSTALL = /usr/local/bin/install -c
- INSTALLDATA = /usr/local/bin/install -c -m 644
-
- # Things you might add to DEFS:
- # -DSTDC_HEADERS If you have ANSI C headers and
- # libraries.
- # -DPOSIX If you have POSIX.1 headers and
- # libraries.
- # -DBSD42 If you have sys/dir.h (unless
- # you use -DPOSIX), sys/file.h,
- # and st_blocks in `struct stat'.
- # -DUSG If you have System V/ANSI C
- # string and memory functions
- # and headers, sys/sysmacros.h,
- # fcntl.h, getcwd, no valloc,
- # and ndir.h (unless
- # you use -DDIRENT).
- # -DNO_MEMORY_H If USG or STDC_HEADERS but do not
- # include memory.h.
- # -DDIRENT If USG and you have dirent.h
- # instead of ndir.h.
- # -DSIGTYPE=int If your signal handlers
- # return int, not void.
- # -DNO_MTIO If you lack sys/mtio.h
- # (magtape ioctls).
- # -DNO_REMOTE If you do not have a remote shell
- # or rexec.
- # -DUSE_REXEC To use rexec for remote tape
- # operations instead of
- # forking rsh or remsh.
- # -DVPRINTF_MISSING If you lack vprintf function
- # (but have _doprnt).
- # -DDOPRNT_MISSING If you lack _doprnt function.
- # Also need to define
- # -DVPRINTF_MISSING.
- # -DFTIME_MISSING If you lack ftime system call.
- # -DSTRSTR_MISSING If you lack strstr function.
- # -DVALLOC_MISSING If you lack valloc function.
- # -DMKDIR_MISSING If you lack mkdir and
- # rmdir system calls.
- # -DRENAME_MISSING If you lack rename system call.
- # -DFTRUNCATE_MISSING If you lack ftruncate
- # system call.
- # -DV7 On Version 7 Unix (not
- # tested in a long time).
- # -DEMUL_OPEN3 If you lack a 3-argument version
- # of open, and want to emulate it
- # with system calls you do have.
- # -DNO_OPEN3 If you lack the 3-argument open
- # and want to disable the tar -k
- # option instead of emulating open.
- # -DXENIX If you have sys/inode.h
- # and need it 94 to be included.
-
- DEFS = -DSIGTYPE=int -DDIRENT -DSTRSTR_MISSING \
- -DVPRINTF_MISSING -DBSD42
- # Set this to rtapelib.o unless you defined NO_REMOTE,
- # in which case make it empty.
- RTAPELIB = rtapelib.o
- LIBS =
- DEF_AR_FILE = /dev/rmt8
- DEFBLOCKING = 20
-
- CDEBUG = -g
- CFLAGS = $(CDEBUG) -I. -I$(srcdir) $(DEFS) \
- -DDEF_AR_FILE=\"$(DEF_AR_FILE)\" \
- -DDEFBLOCKING=$(DEFBLOCKING)
- LDFLAGS = -g
-
- prefix = /usr/local
- # Prefix for each installed program,
- # normally empty or `g'.
- binprefix =
-
- # The directory to install tar in.
- bindir = $(prefix)/bin
-
- # The directory to install the info files in.
- infodir = $(prefix)/info
-
- #### End of system configuration section. ####
-
- SRC1 = tar.c create.c extract.c buffer.c \
- getoldopt.c update.c gnu.c mangle.c
- SRC2 = version.c list.c names.c diffarch.c \
- port.c wildmat.c getopt.c
- SRC3 = getopt1.c regex.c getdate.y
- SRCS = $(SRC1) $(SRC2) $(SRC3)
- OBJ1 = tar.o create.o extract.o buffer.o \
- getoldopt.o update.o gnu.o mangle.o
- OBJ2 = version.o list.o names.o diffarch.o \
- port.o wildmat.o getopt.o
- OBJ3 = getopt1.o regex.o getdate.o $(RTAPELIB)
- OBJS = $(OBJ1) $(OBJ2) $(OBJ3)
- AUX = README COPYING ChangeLog Makefile.in \
- makefile.pc configure configure.in \
- tar.texinfo tar.info* texinfo.tex \
- tar.h port.h open3.h getopt.h regex.h \
- rmt.h rmt.c rtapelib.c alloca.c \
- msd_dir.h msd_dir.c tcexparg.c \
- level-0 level-1 backup-specs testpad.c
-
- .PHONY: all
- all: tar rmt tar.info
-
- .PHONY: tar
- tar: $(OBJS)
- $(CC) $(LDFLAGS) -o $@ $(OBJS) $(LIBS)
-
- rmt: rmt.c
- $(CC) $(CFLAGS) $(LDFLAGS) -o $@ rmt.c
-
- tar.info: tar.texinfo
- makeinfo tar.texinfo
-
- .PHONY: install
- install: all
- $(INSTALL) tar $(bindir)/$(binprefix)tar
- -test ! -f rmt || $(INSTALL) rmt /etc/rmt
- $(INSTALLDATA) $(srcdir)/tar.info* $(infodir)
-
- $(OBJS): tar.h port.h testpad.h
- regex.o buffer.o tar.o: regex.h
- # getdate.y has 8 shift/reduce conflicts.
-
- testpad.h: testpad
- ./testpad
-
- testpad: testpad.o
- $(CC) -o $@ testpad.o
-
- TAGS: $(SRCS)
- etags $(SRCS)
-
- .PHONY: clean
- clean:
- rm -f *.o tar rmt testpad testpad.h core
-
- .PHONY: distclean
- distclean: clean
- rm -f TAGS Makefile config.status
-
- .PHONY: realclean
- realclean: distclean
- rm -f tar.info*
-
- .PHONY: shar
- shar: $(SRCS) $(AUX)
- shar $(SRCS) $(AUX) | compress \
- > tar-`sed -e '/version_string/!d' \
- -e 's/[^0-9.]*\([0-9.]*\).*/\1/' \
- -e q
- version.c`.shar.Z
-
- .PHONY: dist
- dist: $(SRCS) $(AUX)
- echo tar-`sed \
- -e '/version_string/!d' \
- -e 's/[^0-9.]*\([0-9.]*\).*/\1/' \
- -e q
- version.c` > .fname
- -rm -rf `cat .fname`
- mkdir `cat .fname`
- ln $(SRCS) $(AUX) `cat .fname`
- tar chZf `cat .fname`.tar.Z `cat .fname`
- -rm -rf `cat .fname` .fname
-
- tar.zoo: $(SRCS) $(AUX)
- -rm -rf tmp.dir
- -mkdir tmp.dir
- -rm tar.zoo
- for X in $(SRCS) $(AUX) ; do \
- echo $$X ; \
- sed 's/$$/^M/' $$X \
- > tmp.dir/$$X ; done
- cd tmp.dir ; zoo aM ../tar.zoo *
- -rm -rf tmp.dir
-
-
-File: make.info, Node: GNU Free Documentation License, Next: Concept Index, Prev: Complex Makefile, Up: Top
-
-Appendix D GNU Free Documentation License
-*****************************************
-
- Version 1.2, November 2002
-
- Copyright (C) 2000,2001,2002 Free Software Foundation, Inc.
- 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
-
- Everyone is permitted to copy and distribute verbatim copies
- of this license document, but changing it is not allowed.
-
- 0. PREAMBLE
-
- The purpose of this License is to make a manual, textbook, or other
- functional and useful document "free" in the sense of freedom: to
- assure everyone the effective freedom to copy and redistribute it,
- with or without modifying it, either commercially or
- noncommercially. Secondarily, this License preserves for the
- author and publisher a way to get credit for their work, while not
- being considered responsible for modifications made by others.
-
- This License is a kind of "copyleft", which means that derivative
- works of the document must themselves be free in the same sense.
- It complements the GNU General Public License, which is a copyleft
- license designed for free software.
-
- We have designed this License in order to use it for manuals for
- free software, because free software needs free documentation: a
- free program should come with manuals providing the same freedoms
- that the software does. But this License is not limited to
- software manuals; it can be used for any textual work, regardless
- of subject matter or whether it is published as a printed book.
- We recommend this License principally for works whose purpose is
- instruction or reference.
-
- 1. APPLICABILITY AND DEFINITIONS
-
- This License applies to any manual or other work, in any medium,
- that contains a notice placed by the copyright holder saying it
- can be distributed under the terms of this License. Such a notice
- grants a world-wide, royalty-free license, unlimited in duration,
- to use that work under the conditions stated herein. The
- "Document", below, refers to any such manual or work. Any member
- of the public is a licensee, and is addressed as "you". You
- accept the license if you copy, modify or distribute the work in a
- way requiring permission under copyright law.
-
- A "Modified Version" of the Document means any work containing the
- Document or a portion of it, either copied verbatim, or with
- modifications and/or translated into another language.
-
- A "Secondary Section" is a named appendix or a front-matter section
- of the Document that deals exclusively with the relationship of the
- publishers or authors of the Document to the Document's overall
- subject (or to related matters) and contains nothing that could
- fall directly within that overall subject. (Thus, if the Document
- is in part a textbook of mathematics, a Secondary Section may not
- explain any mathematics.) The relationship could be a matter of
- historical connection with the subject or with related matters, or
- of legal, commercial, philosophical, ethical or political position
- regarding them.
-
- The "Invariant Sections" are certain Secondary Sections whose
- titles are designated, as being those of Invariant Sections, in
- the notice that says that the Document is released under this
- License. If a section does not fit the above definition of
- Secondary then it is not allowed to be designated as Invariant.
- The Document may contain zero Invariant Sections. If the Document
- does not identify any Invariant Sections then there are none.
-
- The "Cover Texts" are certain short passages of text that are
- listed, as Front-Cover Texts or Back-Cover Texts, in the notice
- that says that the Document is released under this License. A
- Front-Cover Text may be at most 5 words, and a Back-Cover Text may
- be at most 25 words.
-
- A "Transparent" copy of the Document means a machine-readable copy,
- represented in a format whose specification is available to the
- general public, that is suitable for revising the document
- straightforwardly with generic text editors or (for images
- composed of pixels) generic paint programs or (for drawings) some
- widely available drawing editor, and that is suitable for input to
- text formatters or for automatic translation to a variety of
- formats suitable for input to text formatters. A copy made in an
- otherwise Transparent file format whose markup, or absence of
- markup, has been arranged to thwart or discourage subsequent
- modification by readers is not Transparent. An image format is
- not Transparent if used for any substantial amount of text. A
- copy that is not "Transparent" is called "Opaque".
-
- Examples of suitable formats for Transparent copies include plain
- ASCII without markup, Texinfo input format, LaTeX input format,
- SGML or XML using a publicly available DTD, and
- standard-conforming simple HTML, PostScript or PDF designed for
- human modification. Examples of transparent image formats include
- PNG, XCF and JPG. Opaque formats include proprietary formats that
- can be read and edited only by proprietary word processors, SGML or
- XML for which the DTD and/or processing tools are not generally
- available, and the machine-generated HTML, PostScript or PDF
- produced by some word processors for output purposes only.
-
- The "Title Page" means, for a printed book, the title page itself,
- plus such following pages as are needed to hold, legibly, the
- material this License requires to appear in the title page. For
- works in formats which do not have any title page as such, "Title
- Page" means the text near the most prominent appearance of the
- work's title, preceding the beginning of the body of the text.
-
- A section "Entitled XYZ" means a named subunit of the Document
- whose title either is precisely XYZ or contains XYZ in parentheses
- following text that translates XYZ in another language. (Here XYZ
- stands for a specific section name mentioned below, such as
- "Acknowledgements", "Dedications", "Endorsements", or "History".)
- To "Preserve the Title" of such a section when you modify the
- Document means that it remains a section "Entitled XYZ" according
- to this definition.
-
- The Document may include Warranty Disclaimers next to the notice
- which states that this License applies to the Document. These
- Warranty Disclaimers are considered to be included by reference in
- this License, but only as regards disclaiming warranties: any other
- implication that these Warranty Disclaimers may have is void and
- has no effect on the meaning of this License.
-
- 2. VERBATIM COPYING
-
- You may copy and distribute the Document in any medium, either
- commercially or noncommercially, provided that this License, the
- copyright notices, and the license notice saying this License
- applies to the Document are reproduced in all copies, and that you
- add no other conditions whatsoever to those of this License. You
- may not use technical measures to obstruct or control the reading
- or further copying of the copies you make or distribute. However,
- you may accept compensation in exchange for copies. If you
- distribute a large enough number of copies you must also follow
- the conditions in section 3.
-
- You may also lend copies, under the same conditions stated above,
- and you may publicly display copies.
-
- 3. COPYING IN QUANTITY
-
- If you publish printed copies (or copies in media that commonly
- have printed covers) of the Document, numbering more than 100, and
- the Document's license notice requires Cover Texts, you must
- enclose the copies in covers that carry, clearly and legibly, all
- these Cover Texts: Front-Cover Texts on the front cover, and
- Back-Cover Texts on the back cover. Both covers must also clearly
- and legibly identify you as the publisher of these copies. The
- front cover must present the full title with all words of the
- title equally prominent and visible. You may add other material
- on the covers in addition. Copying with changes limited to the
- covers, as long as they preserve the title of the Document and
- satisfy these conditions, can be treated as verbatim copying in
- other respects.
-
- If the required texts for either cover are too voluminous to fit
- legibly, you should put the first ones listed (as many as fit
- reasonably) on the actual cover, and continue the rest onto
- adjacent pages.
-
- If you publish or distribute Opaque copies of the Document
- numbering more than 100, you must either include a
- machine-readable Transparent copy along with each Opaque copy, or
- state in or with each Opaque copy a computer-network location from
- which the general network-using public has access to download
- using public-standard network protocols a complete Transparent
- copy of the Document, free of added material. If you use the
- latter option, you must take reasonably prudent steps, when you
- begin distribution of Opaque copies in quantity, to ensure that
- this Transparent copy will remain thus accessible at the stated
- location until at least one year after the last time you
- distribute an Opaque copy (directly or through your agents or
- retailers) of that edition to the public.
-
- It is requested, but not required, that you contact the authors of
- the Document well before redistributing any large number of
- copies, to give them a chance to provide you with an updated
- version of the Document.
-
- 4. MODIFICATIONS
-
- You may copy and distribute a Modified Version of the Document
- under the conditions of sections 2 and 3 above, provided that you
- release the Modified Version under precisely this License, with
- the Modified Version filling the role of the Document, thus
- licensing distribution and modification of the Modified Version to
- whoever possesses a copy of it. In addition, you must do these
- things in the Modified Version:
-
- A. Use in the Title Page (and on the covers, if any) a title
- distinct from that of the Document, and from those of
- previous versions (which should, if there were any, be listed
- in the History section of the Document). You may use the
- same title as a previous version if the original publisher of
- that version gives permission.
-
- B. List on the Title Page, as authors, one or more persons or
- entities responsible for authorship of the modifications in
- the Modified Version, together with at least five of the
- principal authors of the Document (all of its principal
- authors, if it has fewer than five), unless they release you
- from this requirement.
-
- C. State on the Title page the name of the publisher of the
- Modified Version, as the publisher.
-
- D. Preserve all the copyright notices of the Document.
-
- E. Add an appropriate copyright notice for your modifications
- adjacent to the other copyright notices.
-
- F. Include, immediately after the copyright notices, a license
- notice giving the public permission to use the Modified
- Version under the terms of this License, in the form shown in
- the Addendum below.
-
- G. Preserve in that license notice the full lists of Invariant
- Sections and required Cover Texts given in the Document's
- license notice.
-
- H. Include an unaltered copy of this License.
-
- I. Preserve the section Entitled "History", Preserve its Title,
- and add to it an item stating at least the title, year, new
- authors, and publisher of the Modified Version as given on
- the Title Page. If there is no section Entitled "History" in
- the Document, create one stating the title, year, authors,
- and publisher of the Document as given on its Title Page,
- then add an item describing the Modified Version as stated in
- the previous sentence.
-
- J. Preserve the network location, if any, given in the Document
- for public access to a Transparent copy of the Document, and
- likewise the network locations given in the Document for
- previous versions it was based on. These may be placed in
- the "History" section. You may omit a network location for a
- work that was published at least four years before the
- Document itself, or if the original publisher of the version
- it refers to gives permission.
-
- K. For any section Entitled "Acknowledgements" or "Dedications",
- Preserve the Title of the section, and preserve in the
- section all the substance and tone of each of the contributor
- acknowledgements and/or dedications given therein.
-
- L. Preserve all the Invariant Sections of the Document,
- unaltered in their text and in their titles. Section numbers
- or the equivalent are not considered part of the section
- titles.
-
- M. Delete any section Entitled "Endorsements". Such a section
- may not be included in the Modified Version.
-
- N. Do not retitle any existing section to be Entitled
- "Endorsements" or to conflict in title with any Invariant
- Section.
-
- O. Preserve any Warranty Disclaimers.
-
- If the Modified Version includes new front-matter sections or
- appendices that qualify as Secondary Sections and contain no
- material copied from the Document, you may at your option
- designate some or all of these sections as invariant. To do this,
- add their titles to the list of Invariant Sections in the Modified
- Version's license notice. These titles must be distinct from any
- other section titles.
-
- You may add a section Entitled "Endorsements", provided it contains
- nothing but endorsements of your Modified Version by various
- parties--for example, statements of peer review or that the text
- has been approved by an organization as the authoritative
- definition of a standard.
-
- You may add a passage of up to five words as a Front-Cover Text,
- and a passage of up to 25 words as a Back-Cover Text, to the end
- of the list of Cover Texts in the Modified Version. Only one
- passage of Front-Cover Text and one of Back-Cover Text may be
- added by (or through arrangements made by) any one entity. If the
- Document already includes a cover text for the same cover,
- previously added by you or by arrangement made by the same entity
- you are acting on behalf of, you may not add another; but you may
- replace the old one, on explicit permission from the previous
- publisher that added the old one.
-
- The author(s) and publisher(s) of the Document do not by this
- License give permission to use their names for publicity for or to
- assert or imply endorsement of any Modified Version.
-
- 5. COMBINING DOCUMENTS
-
- You may combine the Document with other documents released under
- this License, under the terms defined in section 4 above for
- modified versions, provided that you include in the combination
- all of the Invariant Sections of all of the original documents,
- unmodified, and list them all as Invariant Sections of your
- combined work in its license notice, and that you preserve all
- their Warranty Disclaimers.
-
- The combined work need only contain one copy of this License, and
- multiple identical Invariant Sections may be replaced with a single
- copy. If there are multiple Invariant Sections with the same name
- but different contents, make the title of each such section unique
- by adding at the end of it, in parentheses, the name of the
- original author or publisher of that section if known, or else a
- unique number. Make the same adjustment to the section titles in
- the list of Invariant Sections in the license notice of the
- combined work.
-
- In the combination, you must combine any sections Entitled
- "History" in the various original documents, forming one section
- Entitled "History"; likewise combine any sections Entitled
- "Acknowledgements", and any sections Entitled "Dedications". You
- must delete all sections Entitled "Endorsements."
-
- 6. COLLECTIONS OF DOCUMENTS
-
- You may make a collection consisting of the Document and other
- documents released under this License, and replace the individual
- copies of this License in the various documents with a single copy
- that is included in the collection, provided that you follow the
- rules of this License for verbatim copying of each of the
- documents in all other respects.
-
- You may extract a single document from such a collection, and
- distribute it individually under this License, provided you insert
- a copy of this License into the extracted document, and follow
- this License in all other respects regarding verbatim copying of
- that document.
-
- 7. AGGREGATION WITH INDEPENDENT WORKS
-
- A compilation of the Document or its derivatives with other
- separate and independent documents or works, in or on a volume of
- a storage or distribution medium, is called an "aggregate" if the
- copyright resulting from the compilation is not used to limit the
- legal rights of the compilation's users beyond what the individual
- works permit. When the Document is included in an aggregate, this
- License does not apply to the other works in the aggregate which
- are not themselves derivative works of the Document.
-
- If the Cover Text requirement of section 3 is applicable to these
- copies of the Document, then if the Document is less than one half
- of the entire aggregate, the Document's Cover Texts may be placed
- on covers that bracket the Document within the aggregate, or the
- electronic equivalent of covers if the Document is in electronic
- form. Otherwise they must appear on printed covers that bracket
- the whole aggregate.
-
- 8. TRANSLATION
-
- Translation is considered a kind of modification, so you may
- distribute translations of the Document under the terms of section
- 4. Replacing Invariant Sections with translations requires special
- permission from their copyright holders, but you may include
- translations of some or all Invariant Sections in addition to the
- original versions of these Invariant Sections. You may include a
- translation of this License, and all the license notices in the
- Document, and any Warranty Disclaimers, provided that you also
- include the original English version of this License and the
- original versions of those notices and disclaimers. In case of a
- disagreement between the translation and the original version of
- this License or a notice or disclaimer, the original version will
- prevail.
-
- If a section in the Document is Entitled "Acknowledgements",
- "Dedications", or "History", the requirement (section 4) to
- Preserve its Title (section 1) will typically require changing the
- actual title.
-
- 9. TERMINATION
-
- You may not copy, modify, sublicense, or distribute the Document
- except as expressly provided for under this License. Any other
- attempt to copy, modify, sublicense or distribute the Document is
- void, and will automatically terminate your rights under this
- License. However, parties who have received copies, or rights,
- from you under this License will not have their licenses
- terminated so long as such parties remain in full compliance.
-
- 10. FUTURE REVISIONS OF THIS LICENSE
-
- The Free Software Foundation may publish new, revised versions of
- the GNU Free Documentation License from time to time. Such new
- versions will be similar in spirit to the present version, but may
- differ in detail to address new problems or concerns. See
- `http://www.gnu.org/copyleft/'.
-
- Each version of the License is given a distinguishing version
- number. If the Document specifies that a particular numbered
- version of this License "or any later version" applies to it, you
- have the option of following the terms and conditions either of
- that specified version or of any later version that has been
- published (not as a draft) by the Free Software Foundation. If
- the Document does not specify a version number of this License,
- you may choose any version ever published (not as a draft) by the
- Free Software Foundation.
-
-D.1 ADDENDUM: How to use this License for your documents
-========================================================
-
-To use this License in a document you have written, include a copy of
-the License in the document and put the following copyright and license
-notices just after the title page:
-
- Copyright (C) YEAR YOUR NAME.
- Permission is granted to copy, distribute and/or modify this document
- under the terms of the GNU Free Documentation License, Version 1.2
- or any later version published by the Free Software Foundation;
- with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
- Texts. A copy of the license is included in the section entitled ``GNU
- Free Documentation License''.
-
- If you have Invariant Sections, Front-Cover Texts and Back-Cover
-Texts, replace the "with...Texts." line with this:
-
- with the Invariant Sections being LIST THEIR TITLES, with
- the Front-Cover Texts being LIST, and with the Back-Cover Texts
- being LIST.
-
- If you have Invariant Sections without Cover Texts, or some other
-combination of the three, merge those two alternatives to suit the
-situation.
-
- If your document contains nontrivial examples of program code, we
-recommend releasing these examples in parallel under your choice of
-free software license, such as the GNU General Public License, to
-permit their use in free software.
-
-
-File: make.info, Node: Concept Index, Next: Name Index, Prev: GNU Free Documentation License, Up: Top
-
-Index of Concepts
-*****************
-
-[index]
-* Menu:
-
-* # (comments), in commands: Command Syntax. (line 27)
-* # (comments), in makefile: Makefile Contents. (line 41)
-* #include: Automatic Prerequisites.
- (line 16)
-* $, in function call: Syntax of Functions. (line 6)
-* $, in rules: Rule Syntax. (line 32)
-* $, in variable name: Computed Names. (line 6)
-* $, in variable reference: Reference. (line 6)
-* %, in pattern rules: Pattern Intro. (line 9)
-* %, quoting in patsubst: Text Functions. (line 26)
-* %, quoting in static pattern: Static Usage. (line 37)
-* %, quoting in vpath: Selective Search. (line 38)
-* %, quoting with \ (backslash) <1>: Text Functions. (line 26)
-* %, quoting with \ (backslash) <2>: Static Usage. (line 37)
-* %, quoting with \ (backslash): Selective Search. (line 38)
-* * (wildcard character): Wildcards. (line 6)
-* +, and command execution: Instead of Execution.
- (line 58)
-* +, and commands: MAKE Variable. (line 18)
-* +, and define: Sequences. (line 50)
-* +=: Appending. (line 6)
-* +=, expansion: Reading Makefiles. (line 33)
-* ,v (RCS file extension): Catalogue of Rules. (line 164)
-* - (in commands): Errors. (line 19)
-* -, and define: Sequences. (line 50)
-* --always-make: Options Summary. (line 15)
-* --assume-new <1>: Options Summary. (line 242)
-* --assume-new: Instead of Execution.
- (line 33)
-* --assume-new, and recursion: Options/Recursion. (line 22)
-* --assume-old <1>: Options Summary. (line 147)
-* --assume-old: Avoiding Compilation.
- (line 6)
-* --assume-old, and recursion: Options/Recursion. (line 22)
-* --check-symlink-times: Options Summary. (line 130)
-* --debug: Options Summary. (line 42)
-* --directory <1>: Options Summary. (line 26)
-* --directory: Recursion. (line 20)
-* --directory, and --print-directory: -w Option. (line 20)
-* --directory, and recursion: Options/Recursion. (line 22)
-* --dry-run <1>: Options Summary. (line 140)
-* --dry-run <2>: Instead of Execution.
- (line 14)
-* --dry-run: Echoing. (line 18)
-* --environment-overrides: Options Summary. (line 78)
-* --file <1>: Options Summary. (line 84)
-* --file <2>: Makefile Arguments. (line 6)
-* --file: Makefile Names. (line 23)
-* --file, and recursion: Options/Recursion. (line 22)
-* --help: Options Summary. (line 90)
-* --ignore-errors <1>: Options Summary. (line 94)
-* --ignore-errors: Errors. (line 30)
-* --include-dir <1>: Options Summary. (line 99)
-* --include-dir: Include. (line 52)
-* --jobs <1>: Options Summary. (line 106)
-* --jobs: Parallel. (line 6)
-* --jobs, and recursion: Options/Recursion. (line 25)
-* --just-print <1>: Options Summary. (line 139)
-* --just-print <2>: Instead of Execution.
- (line 14)
-* --just-print: Echoing. (line 18)
-* --keep-going <1>: Options Summary. (line 115)
-* --keep-going <2>: Testing. (line 16)
-* --keep-going: Errors. (line 47)
-* --load-average <1>: Options Summary. (line 122)
-* --load-average: Parallel. (line 57)
-* --makefile <1>: Options Summary. (line 85)
-* --makefile <2>: Makefile Arguments. (line 6)
-* --makefile: Makefile Names. (line 23)
-* --max-load <1>: Options Summary. (line 123)
-* --max-load: Parallel. (line 57)
-* --new-file <1>: Options Summary. (line 241)
-* --new-file: Instead of Execution.
- (line 33)
-* --new-file, and recursion: Options/Recursion. (line 22)
-* --no-builtin-rules: Options Summary. (line 175)
-* --no-builtin-variables: Options Summary. (line 188)
-* --no-keep-going: Options Summary. (line 203)
-* --no-print-directory <1>: Options Summary. (line 233)
-* --no-print-directory: -w Option. (line 20)
-* --old-file <1>: Options Summary. (line 146)
-* --old-file: Avoiding Compilation.
- (line 6)
-* --old-file, and recursion: Options/Recursion. (line 22)
-* --print-data-base: Options Summary. (line 155)
-* --print-directory: Options Summary. (line 225)
-* --print-directory, and --directory: -w Option. (line 20)
-* --print-directory, and recursion: -w Option. (line 20)
-* --print-directory, disabling: -w Option. (line 20)
-* --question <1>: Options Summary. (line 167)
-* --question: Instead of Execution.
- (line 25)
-* --quiet <1>: Options Summary. (line 198)
-* --quiet: Echoing. (line 24)
-* --recon <1>: Options Summary. (line 141)
-* --recon <2>: Instead of Execution.
- (line 14)
-* --recon: Echoing. (line 18)
-* --silent <1>: Options Summary. (line 197)
-* --silent: Echoing. (line 24)
-* --stop: Options Summary. (line 204)
-* --touch <1>: Options Summary. (line 212)
-* --touch: Instead of Execution.
- (line 19)
-* --touch, and recursion: MAKE Variable. (line 34)
-* --version: Options Summary. (line 220)
-* --warn-undefined-variables: Options Summary. (line 251)
-* --what-if <1>: Options Summary. (line 240)
-* --what-if: Instead of Execution.
- (line 33)
-* -B: Options Summary. (line 14)
-* -b: Options Summary. (line 9)
-* -C <1>: Options Summary. (line 25)
-* -C: Recursion. (line 20)
-* -C, and -w: -w Option. (line 20)
-* -C, and recursion: Options/Recursion. (line 22)
-* -d: Options Summary. (line 33)
-* -e: Options Summary. (line 77)
-* -e (shell flag): Automatic Prerequisites.
- (line 66)
-* -f <1>: Options Summary. (line 83)
-* -f <2>: Makefile Arguments. (line 6)
-* -f: Makefile Names. (line 23)
-* -f, and recursion: Options/Recursion. (line 22)
-* -h: Options Summary. (line 89)
-* -I: Options Summary. (line 98)
-* -i <1>: Options Summary. (line 93)
-* -i: Errors. (line 30)
-* -I: Include. (line 52)
-* -j <1>: Options Summary. (line 105)
-* -j: Parallel. (line 6)
-* -j, and archive update: Archive Pitfalls. (line 6)
-* -j, and recursion: Options/Recursion. (line 25)
-* -k <1>: Options Summary. (line 114)
-* -k <2>: Testing. (line 16)
-* -k: Errors. (line 47)
-* -L: Options Summary. (line 129)
-* -l: Options Summary. (line 121)
-* -l (library search): Libraries/Search. (line 6)
-* -l (load average): Parallel. (line 57)
-* -m: Options Summary. (line 10)
-* -M (to compiler): Automatic Prerequisites.
- (line 18)
-* -MM (to GNU compiler): Automatic Prerequisites.
- (line 68)
-* -n <1>: Options Summary. (line 138)
-* -n <2>: Instead of Execution.
- (line 14)
-* -n: Echoing. (line 18)
-* -o <1>: Options Summary. (line 145)
-* -o: Avoiding Compilation.
- (line 6)
-* -o, and recursion: Options/Recursion. (line 22)
-* -p: Options Summary. (line 154)
-* -q <1>: Options Summary. (line 166)
-* -q: Instead of Execution.
- (line 25)
-* -R: Options Summary. (line 187)
-* -r: Options Summary. (line 174)
-* -S: Options Summary. (line 202)
-* -s <1>: Options Summary. (line 196)
-* -s: Echoing. (line 24)
-* -t <1>: Options Summary. (line 211)
-* -t: Instead of Execution.
- (line 19)
-* -t, and recursion: MAKE Variable. (line 34)
-* -v: Options Summary. (line 219)
-* -W: Options Summary. (line 239)
-* -w: Options Summary. (line 224)
-* -W: Instead of Execution.
- (line 33)
-* -w, and -C: -w Option. (line 20)
-* -w, and recursion: -w Option. (line 20)
-* -W, and recursion: Options/Recursion. (line 22)
-* -w, disabling: -w Option. (line 20)
-* .a (archives): Archive Suffix Rules.
- (line 6)
-* .C: Catalogue of Rules. (line 39)
-* .c: Catalogue of Rules. (line 35)
-* .cc: Catalogue of Rules. (line 39)
-* .ch: Catalogue of Rules. (line 151)
-* .cpp: Catalogue of Rules. (line 39)
-* .d: Automatic Prerequisites.
- (line 81)
-* .def: Catalogue of Rules. (line 74)
-* .dvi: Catalogue of Rules. (line 151)
-* .F: Catalogue of Rules. (line 49)
-* .f: Catalogue of Rules. (line 49)
-* .info: Catalogue of Rules. (line 158)
-* .l: Catalogue of Rules. (line 124)
-* .LIBPATTERNS, and link libraries: Libraries/Search. (line 6)
-* .ln: Catalogue of Rules. (line 146)
-* .mod: Catalogue of Rules. (line 74)
-* .o: Catalogue of Rules. (line 35)
-* .p: Catalogue of Rules. (line 45)
-* .PRECIOUS intermediate files: Chained Rules. (line 56)
-* .r: Catalogue of Rules. (line 49)
-* .S: Catalogue of Rules. (line 82)
-* .s: Catalogue of Rules. (line 79)
-* .sh: Catalogue of Rules. (line 180)
-* .sym: Catalogue of Rules. (line 74)
-* .tex: Catalogue of Rules. (line 151)
-* .texi: Catalogue of Rules. (line 158)
-* .texinfo: Catalogue of Rules. (line 158)
-* .txinfo: Catalogue of Rules. (line 158)
-* .w: Catalogue of Rules. (line 151)
-* .web: Catalogue of Rules. (line 151)
-* .y: Catalogue of Rules. (line 120)
-* :: rules (double-colon): Double-Colon. (line 6)
-* := <1>: Setting. (line 6)
-* :=: Flavors. (line 56)
-* = <1>: Setting. (line 6)
-* =: Flavors. (line 10)
-* =, expansion: Reading Makefiles. (line 33)
-* ? (wildcard character): Wildcards. (line 6)
-* ?= <1>: Setting. (line 6)
-* ?=: Flavors. (line 129)
-* ?=, expansion: Reading Makefiles. (line 33)
-* @ (in commands): Echoing. (line 6)
-* @, and define: Sequences. (line 50)
-* [...] (wildcard characters): Wildcards. (line 6)
-* \ (backslash), for continuation lines: Simple Makefile. (line 40)
-* \ (backslash), in commands: Splitting Lines. (line 6)
-* \ (backslash), to quote % <1>: Text Functions. (line 26)
-* \ (backslash), to quote % <2>: Static Usage. (line 37)
-* \ (backslash), to quote %: Selective Search. (line 38)
-* __.SYMDEF: Archive Symbols. (line 6)
-* abspath: File Name Functions. (line 121)
-* algorithm for directory search: Search Algorithm. (line 6)
-* all (standard target): Goals. (line 72)
-* appending to variables: Appending. (line 6)
-* ar: Implicit Variables. (line 41)
-* archive: Archives. (line 6)
-* archive member targets: Archive Members. (line 6)
-* archive symbol directory updating: Archive Symbols. (line 6)
-* archive, and -j: Archive Pitfalls. (line 6)
-* archive, and parallel execution: Archive Pitfalls. (line 6)
-* archive, suffix rule for: Archive Suffix Rules.
- (line 6)
-* Arg list too long: Options/Recursion. (line 57)
-* arguments of functions: Syntax of Functions. (line 6)
-* as <1>: Implicit Variables. (line 44)
-* as: Catalogue of Rules. (line 79)
-* assembly, rule to compile: Catalogue of Rules. (line 79)
-* automatic generation of prerequisites <1>: Automatic Prerequisites.
- (line 6)
-* automatic generation of prerequisites: Include. (line 50)
-* automatic variables: Automatic Variables. (line 6)
-* automatic variables in prerequisites: Automatic Variables. (line 17)
-* backquotes: Shell Function. (line 6)
-* backslash (\), for continuation lines: Simple Makefile. (line 40)
-* backslash (\), in commands: Splitting Lines. (line 6)
-* backslash (\), to quote % <1>: Text Functions. (line 26)
-* backslash (\), to quote % <2>: Static Usage. (line 37)
-* backslash (\), to quote %: Selective Search. (line 38)
-* backslashes in pathnames and wildcard expansion: Wildcard Pitfall.
- (line 31)
-* basename: File Name Functions. (line 57)
-* binary packages: Install Command Categories.
- (line 80)
-* broken pipe: Parallel. (line 30)
-* bugs, reporting: Bugs. (line 6)
-* built-in special targets: Special Targets. (line 6)
-* C++, rule to compile: Catalogue of Rules. (line 39)
-* C, rule to compile: Catalogue of Rules. (line 35)
-* cc <1>: Implicit Variables. (line 47)
-* cc: Catalogue of Rules. (line 35)
-* cd (shell command) <1>: MAKE Variable. (line 16)
-* cd (shell command): Execution. (line 10)
-* chains of rules: Chained Rules. (line 6)
-* check (standard target): Goals. (line 114)
-* clean (standard target): Goals. (line 75)
-* clean target <1>: Cleanup. (line 11)
-* clean target: Simple Makefile. (line 83)
-* cleaning up: Cleanup. (line 6)
-* clobber (standard target): Goals. (line 86)
-* co <1>: Implicit Variables. (line 56)
-* co: Catalogue of Rules. (line 164)
-* combining rules by prerequisite: Combine By Prerequisite.
- (line 6)
-* command line variable definitions, and recursion: Options/Recursion.
- (line 17)
-* command line variables: Overriding. (line 6)
-* command syntax: Command Syntax. (line 6)
-* commands: Rule Syntax. (line 26)
-* commands setting shell variables: Execution. (line 10)
-* commands, backslash (\) in: Splitting Lines. (line 6)
-* commands, comments in: Command Syntax. (line 27)
-* commands, echoing: Echoing. (line 6)
-* commands, empty: Empty Commands. (line 6)
-* commands, errors in: Errors. (line 6)
-* commands, execution: Execution. (line 6)
-* commands, execution in parallel: Parallel. (line 6)
-* commands, expansion: Shell Function. (line 6)
-* commands, how to write: Commands. (line 6)
-* commands, instead of executing: Instead of Execution.
- (line 6)
-* commands, introduction to: Rule Introduction. (line 8)
-* commands, quoting newlines in: Splitting Lines. (line 6)
-* commands, sequences of: Sequences. (line 6)
-* commands, splitting: Splitting Lines. (line 6)
-* commands, using variables in: Variables in Commands.
- (line 6)
-* comments, in commands: Command Syntax. (line 27)
-* comments, in makefile: Makefile Contents. (line 41)
-* compatibility: Features. (line 6)
-* compatibility in exporting: Variables/Recursion. (line 105)
-* compilation, testing: Testing. (line 6)
-* computed variable name: Computed Names. (line 6)
-* conditional expansion: Conditional Functions.
- (line 6)
-* conditional variable assignment: Flavors. (line 129)
-* conditionals: Conditionals. (line 6)
-* continuation lines: Simple Makefile. (line 40)
-* controlling make: Make Control Functions.
- (line 6)
-* conventions for makefiles: Makefile Conventions.
- (line 6)
-* ctangle <1>: Implicit Variables. (line 107)
-* ctangle: Catalogue of Rules. (line 151)
-* cweave <1>: Implicit Variables. (line 101)
-* cweave: Catalogue of Rules. (line 151)
-* data base of make rules: Options Summary. (line 155)
-* deducing commands (implicit rules): make Deduces. (line 6)
-* default directories for included makefiles: Include. (line 52)
-* default goal <1>: Rules. (line 11)
-* default goal: How Make Works. (line 11)
-* default makefile name: Makefile Names. (line 6)
-* default rules, last-resort: Last Resort. (line 6)
-* define, expansion: Reading Makefiles. (line 33)
-* defining variables verbatim: Defining. (line 6)
-* deletion of target files <1>: Interrupts. (line 6)
-* deletion of target files: Errors. (line 64)
-* directive: Makefile Contents. (line 28)
-* directories, printing them: -w Option. (line 6)
-* directories, updating archive symbol: Archive Symbols. (line 6)
-* directory part: File Name Functions. (line 17)
-* directory search (VPATH): Directory Search. (line 6)
-* directory search (VPATH), and implicit rules: Implicit/Search.
- (line 6)
-* directory search (VPATH), and link libraries: Libraries/Search.
- (line 6)
-* directory search (VPATH), and shell commands: Commands/Search.
- (line 6)
-* directory search algorithm: Search Algorithm. (line 6)
-* directory search, traditional (GPATH): Search Algorithm. (line 42)
-* dist (standard target): Goals. (line 106)
-* distclean (standard target): Goals. (line 84)
-* dollar sign ($), in function call: Syntax of Functions. (line 6)
-* dollar sign ($), in rules: Rule Syntax. (line 32)
-* dollar sign ($), in variable name: Computed Names. (line 6)
-* dollar sign ($), in variable reference: Reference. (line 6)
-* DOS, choosing a shell in: Choosing the Shell. (line 36)
-* double-colon rules: Double-Colon. (line 6)
-* duplicate words, removing: Text Functions. (line 155)
-* E2BIG: Options/Recursion. (line 57)
-* echoing of commands: Echoing. (line 6)
-* editor: Introduction. (line 22)
-* Emacs (M-x compile): Errors. (line 62)
-* empty commands: Empty Commands. (line 6)
-* empty targets: Empty Targets. (line 6)
-* environment: Environment. (line 6)
-* environment, and recursion: Variables/Recursion. (line 6)
-* environment, SHELL in: Choosing the Shell. (line 10)
-* error, stopping on: Make Control Functions.
- (line 11)
-* errors (in commands): Errors. (line 6)
-* errors with wildcards: Wildcard Pitfall. (line 6)
-* evaluating makefile syntax: Eval Function. (line 6)
-* execution, in parallel: Parallel. (line 6)
-* execution, instead of: Instead of Execution.
- (line 6)
-* execution, of commands: Execution. (line 6)
-* exit status (errors): Errors. (line 6)
-* exit status of make: Running. (line 18)
-* expansion, secondary: Secondary Expansion. (line 6)
-* explicit rule, definition of: Makefile Contents. (line 10)
-* explicit rule, expansion: Reading Makefiles. (line 62)
-* explicit rules, secondary expansion of: Secondary Expansion.
- (line 106)
-* exporting variables: Variables/Recursion. (line 6)
-* f77 <1>: Implicit Variables. (line 64)
-* f77: Catalogue of Rules. (line 49)
-* FDL, GNU Free Documentation License: GNU Free Documentation License.
- (line 6)
-* features of GNU make: Features. (line 6)
-* features, missing: Missing. (line 6)
-* file name functions: File Name Functions. (line 6)
-* file name of makefile: Makefile Names. (line 6)
-* file name of makefile, how to specify: Makefile Names. (line 30)
-* file name prefix, adding: File Name Functions. (line 79)
-* file name suffix: File Name Functions. (line 43)
-* file name suffix, adding: File Name Functions. (line 68)
-* file name with wildcards: Wildcards. (line 6)
-* file name, abspath of: File Name Functions. (line 121)
-* file name, basename of: File Name Functions. (line 57)
-* file name, directory part: File Name Functions. (line 17)
-* file name, nondirectory part: File Name Functions. (line 27)
-* file name, realpath of: File Name Functions. (line 114)
-* files, assuming new: Instead of Execution.
- (line 33)
-* files, assuming old: Avoiding Compilation.
- (line 6)
-* files, avoiding recompilation of: Avoiding Compilation.
- (line 6)
-* files, intermediate: Chained Rules. (line 16)
-* filtering out words: Text Functions. (line 132)
-* filtering words: Text Functions. (line 114)
-* finding strings: Text Functions. (line 103)
-* flags: Options Summary. (line 6)
-* flags for compilers: Implicit Variables. (line 6)
-* flavor of variable: Flavor Function. (line 6)
-* flavors of variables: Flavors. (line 6)
-* FORCE: Force Targets. (line 6)
-* force targets: Force Targets. (line 6)
-* Fortran, rule to compile: Catalogue of Rules. (line 49)
-* functions: Functions. (line 6)
-* functions, for controlling make: Make Control Functions.
- (line 6)
-* functions, for file names: File Name Functions. (line 6)
-* functions, for text: Text Functions. (line 6)
-* functions, syntax of: Syntax of Functions. (line 6)
-* functions, user defined: Call Function. (line 6)
-* g++ <1>: Implicit Variables. (line 53)
-* g++: Catalogue of Rules. (line 39)
-* gcc: Catalogue of Rules. (line 35)
-* generating prerequisites automatically <1>: Automatic Prerequisites.
- (line 6)
-* generating prerequisites automatically: Include. (line 50)
-* get <1>: Implicit Variables. (line 67)
-* get: Catalogue of Rules. (line 173)
-* globbing (wildcards): Wildcards. (line 6)
-* goal: How Make Works. (line 11)
-* goal, default <1>: Rules. (line 11)
-* goal, default: How Make Works. (line 11)
-* goal, how to specify: Goals. (line 6)
-* home directory: Wildcards. (line 11)
-* IEEE Standard 1003.2: Overview. (line 13)
-* ifdef, expansion: Reading Makefiles. (line 51)
-* ifeq, expansion: Reading Makefiles. (line 51)
-* ifndef, expansion: Reading Makefiles. (line 51)
-* ifneq, expansion: Reading Makefiles. (line 51)
-* implicit rule: Implicit Rules. (line 6)
-* implicit rule, and directory search: Implicit/Search. (line 6)
-* implicit rule, and VPATH: Implicit/Search. (line 6)
-* implicit rule, definition of: Makefile Contents. (line 16)
-* implicit rule, expansion: Reading Makefiles. (line 62)
-* implicit rule, how to use: Using Implicit. (line 6)
-* implicit rule, introduction to: make Deduces. (line 6)
-* implicit rule, predefined: Catalogue of Rules. (line 6)
-* implicit rule, search algorithm: Implicit Rule Search.
- (line 6)
-* implicit rules, secondary expansion of: Secondary Expansion.
- (line 146)
-* included makefiles, default directories: Include. (line 52)
-* including (MAKEFILE_LIST variable): MAKEFILE_LIST Variable.
- (line 6)
-* including (MAKEFILES variable): MAKEFILES Variable. (line 6)
-* including other makefiles: Include. (line 6)
-* incompatibilities: Missing. (line 6)
-* Info, rule to format: Catalogue of Rules. (line 158)
-* install (standard target): Goals. (line 92)
-* intermediate files: Chained Rules. (line 16)
-* intermediate files, preserving: Chained Rules. (line 46)
-* intermediate targets, explicit: Special Targets. (line 44)
-* interrupt: Interrupts. (line 6)
-* job slots: Parallel. (line 6)
-* job slots, and recursion: Options/Recursion. (line 25)
-* jobs, limiting based on load: Parallel. (line 57)
-* joining lists of words: File Name Functions. (line 90)
-* killing (interruption): Interrupts. (line 6)
-* last-resort default rules: Last Resort. (line 6)
-* ld: Catalogue of Rules. (line 86)
-* lex <1>: Implicit Variables. (line 71)
-* lex: Catalogue of Rules. (line 124)
-* Lex, rule to run: Catalogue of Rules. (line 124)
-* libraries for linking, directory search: Libraries/Search. (line 6)
-* library archive, suffix rule for: Archive Suffix Rules.
- (line 6)
-* limiting jobs based on load: Parallel. (line 57)
-* link libraries, and directory search: Libraries/Search. (line 6)
-* link libraries, patterns matching: Libraries/Search. (line 6)
-* linking, predefined rule for: Catalogue of Rules. (line 86)
-* lint <1>: Implicit Variables. (line 78)
-* lint: Catalogue of Rules. (line 146)
-* lint, rule to run: Catalogue of Rules. (line 146)
-* list of all prerequisites: Automatic Variables. (line 61)
-* list of changed prerequisites: Automatic Variables. (line 51)
-* load average: Parallel. (line 57)
-* loops in variable expansion: Flavors. (line 44)
-* lpr (shell command) <1>: Empty Targets. (line 25)
-* lpr (shell command): Wildcard Examples. (line 21)
-* m2c <1>: Implicit Variables. (line 81)
-* m2c: Catalogue of Rules. (line 74)
-* macro: Using Variables. (line 10)
-* make depend: Automatic Prerequisites.
- (line 37)
-* makefile: Introduction. (line 7)
-* makefile name: Makefile Names. (line 6)
-* makefile name, how to specify: Makefile Names. (line 30)
-* makefile rule parts: Rule Introduction. (line 6)
-* makefile syntax, evaluating: Eval Function. (line 6)
-* makefile, and MAKEFILES variable: MAKEFILES Variable. (line 6)
-* makefile, conventions for: Makefile Conventions.
- (line 6)
-* makefile, how make processes: How Make Works. (line 6)
-* makefile, how to write: Makefiles. (line 6)
-* makefile, including: Include. (line 6)
-* makefile, overriding: Overriding Makefiles.
- (line 6)
-* makefile, parsing: Reading Makefiles. (line 6)
-* makefile, remaking of: Remaking Makefiles. (line 6)
-* makefile, simple: Simple Makefile. (line 6)
-* makefiles, and MAKEFILE_LIST variable: MAKEFILE_LIST Variable.
- (line 6)
-* makefiles, and special variables: Special Variables. (line 6)
-* makeinfo <1>: Implicit Variables. (line 88)
-* makeinfo: Catalogue of Rules. (line 158)
-* match-anything rule: Match-Anything Rules.
- (line 6)
-* match-anything rule, used to override: Overriding Makefiles.
- (line 12)
-* missing features: Missing. (line 6)
-* mistakes with wildcards: Wildcard Pitfall. (line 6)
-* modified variable reference: Substitution Refs. (line 6)
-* Modula-2, rule to compile: Catalogue of Rules. (line 74)
-* mostlyclean (standard target): Goals. (line 78)
-* multiple rules for one target: Multiple Rules. (line 6)
-* multiple rules for one target (::): Double-Colon. (line 6)
-* multiple targets: Multiple Targets. (line 6)
-* multiple targets, in pattern rule: Pattern Intro. (line 49)
-* name of makefile: Makefile Names. (line 6)
-* name of makefile, how to specify: Makefile Names. (line 30)
-* nested variable reference: Computed Names. (line 6)
-* newline, quoting, in commands: Splitting Lines. (line 6)
-* newline, quoting, in makefile: Simple Makefile. (line 40)
-* nondirectory part: File Name Functions. (line 27)
-* normal prerequisites: Prerequisite Types. (line 6)
-* OBJ: Variables Simplify. (line 20)
-* obj: Variables Simplify. (line 20)
-* OBJECTS: Variables Simplify. (line 20)
-* objects: Variables Simplify. (line 14)
-* OBJS: Variables Simplify. (line 20)
-* objs: Variables Simplify. (line 20)
-* old-fashioned suffix rules: Suffix Rules. (line 6)
-* options: Options Summary. (line 6)
-* options, and recursion: Options/Recursion. (line 6)
-* options, setting from environment: Options/Recursion. (line 81)
-* options, setting in makefiles: Options/Recursion. (line 81)
-* order of pattern rules: Pattern Intro. (line 57)
-* order-only prerequisites: Prerequisite Types. (line 6)
-* origin of variable: Origin Function. (line 6)
-* overriding makefiles: Overriding Makefiles.
- (line 6)
-* overriding variables with arguments: Overriding. (line 6)
-* overriding with override: Override Directive. (line 6)
-* parallel execution: Parallel. (line 6)
-* parallel execution, and archive update: Archive Pitfalls. (line 6)
-* parallel execution, overriding: Special Targets. (line 135)
-* parts of makefile rule: Rule Introduction. (line 6)
-* Pascal, rule to compile: Catalogue of Rules. (line 45)
-* pattern rule: Pattern Intro. (line 6)
-* pattern rule, expansion: Reading Makefiles. (line 62)
-* pattern rules, order of: Pattern Intro. (line 57)
-* pattern rules, static (not implicit): Static Pattern. (line 6)
-* pattern rules, static, syntax of: Static Usage. (line 6)
-* pattern-specific variables: Pattern-specific. (line 6)
-* pc <1>: Implicit Variables. (line 84)
-* pc: Catalogue of Rules. (line 45)
-* phony targets: Phony Targets. (line 6)
-* pitfalls of wildcards: Wildcard Pitfall. (line 6)
-* portability: Features. (line 6)
-* POSIX: Overview. (line 13)
-* POSIX.2: Options/Recursion. (line 60)
-* post-installation commands: Install Command Categories.
- (line 6)
-* pre-installation commands: Install Command Categories.
- (line 6)
-* precious targets: Special Targets. (line 29)
-* predefined rules and variables, printing: Options Summary. (line 155)
-* prefix, adding: File Name Functions. (line 79)
-* prerequisite: Rules. (line 6)
-* prerequisite pattern, implicit: Pattern Intro. (line 22)
-* prerequisite pattern, static (not implicit): Static Usage. (line 30)
-* prerequisite types: Prerequisite Types. (line 6)
-* prerequisite, expansion: Reading Makefiles. (line 62)
-* prerequisites: Rule Syntax. (line 46)
-* prerequisites, and automatic variables: Automatic Variables.
- (line 17)
-* prerequisites, automatic generation <1>: Automatic Prerequisites.
- (line 6)
-* prerequisites, automatic generation: Include. (line 50)
-* prerequisites, introduction to: Rule Introduction. (line 8)
-* prerequisites, list of all: Automatic Variables. (line 61)
-* prerequisites, list of changed: Automatic Variables. (line 51)
-* prerequisites, normal: Prerequisite Types. (line 6)
-* prerequisites, order-only: Prerequisite Types. (line 6)
-* prerequisites, varying (static pattern): Static Pattern. (line 6)
-* preserving intermediate files: Chained Rules. (line 46)
-* preserving with .PRECIOUS <1>: Chained Rules. (line 56)
-* preserving with .PRECIOUS: Special Targets. (line 29)
-* preserving with .SECONDARY: Special Targets. (line 49)
-* print (standard target): Goals. (line 97)
-* print target <1>: Empty Targets. (line 25)
-* print target: Wildcard Examples. (line 21)
-* printing directories: -w Option. (line 6)
-* printing messages: Make Control Functions.
- (line 43)
-* printing of commands: Echoing. (line 6)
-* printing user warnings: Make Control Functions.
- (line 35)
-* problems and bugs, reporting: Bugs. (line 6)
-* problems with wildcards: Wildcard Pitfall. (line 6)
-* processing a makefile: How Make Works. (line 6)
-* question mode: Instead of Execution.
- (line 25)
-* quoting %, in patsubst: Text Functions. (line 26)
-* quoting %, in static pattern: Static Usage. (line 37)
-* quoting %, in vpath: Selective Search. (line 38)
-* quoting newline, in commands: Splitting Lines. (line 6)
-* quoting newline, in makefile: Simple Makefile. (line 40)
-* Ratfor, rule to compile: Catalogue of Rules. (line 49)
-* RCS, rule to extract from: Catalogue of Rules. (line 164)
-* reading makefiles: Reading Makefiles. (line 6)
-* README: Makefile Names. (line 9)
-* realclean (standard target): Goals. (line 85)
-* realpath: File Name Functions. (line 114)
-* recompilation: Introduction. (line 22)
-* recompilation, avoiding: Avoiding Compilation.
- (line 6)
-* recording events with empty targets: Empty Targets. (line 6)
-* recursion: Recursion. (line 6)
-* recursion, and -C: Options/Recursion. (line 22)
-* recursion, and -f: Options/Recursion. (line 22)
-* recursion, and -j: Options/Recursion. (line 25)
-* recursion, and -o: Options/Recursion. (line 22)
-* recursion, and -t: MAKE Variable. (line 34)
-* recursion, and -w: -w Option. (line 20)
-* recursion, and -W: Options/Recursion. (line 22)
-* recursion, and command line variable definitions: Options/Recursion.
- (line 17)
-* recursion, and environment: Variables/Recursion. (line 6)
-* recursion, and MAKE variable: MAKE Variable. (line 6)
-* recursion, and MAKEFILES variable: MAKEFILES Variable. (line 14)
-* recursion, and options: Options/Recursion. (line 6)
-* recursion, and printing directories: -w Option. (line 6)
-* recursion, and variables: Variables/Recursion. (line 6)
-* recursion, level of: Variables/Recursion. (line 115)
-* recursive variable expansion <1>: Flavors. (line 6)
-* recursive variable expansion: Using Variables. (line 6)
-* recursively expanded variables: Flavors. (line 6)
-* reference to variables <1>: Advanced. (line 6)
-* reference to variables: Reference. (line 6)
-* relinking: How Make Works. (line 46)
-* remaking makefiles: Remaking Makefiles. (line 6)
-* removal of target files <1>: Interrupts. (line 6)
-* removal of target files: Errors. (line 64)
-* removing duplicate words: Text Functions. (line 155)
-* removing targets on failure: Special Targets. (line 68)
-* removing, to clean up: Cleanup. (line 6)
-* reporting bugs: Bugs. (line 6)
-* rm: Implicit Variables. (line 110)
-* rm (shell command) <1>: Errors. (line 27)
-* rm (shell command) <2>: Phony Targets. (line 20)
-* rm (shell command) <3>: Wildcard Examples. (line 12)
-* rm (shell command): Simple Makefile. (line 83)
-* rule commands: Commands. (line 6)
-* rule prerequisites: Rule Syntax. (line 46)
-* rule syntax: Rule Syntax. (line 6)
-* rule targets: Rule Syntax. (line 18)
-* rule, double-colon (::): Double-Colon. (line 6)
-* rule, explicit, definition of: Makefile Contents. (line 10)
-* rule, how to write: Rules. (line 6)
-* rule, implicit: Implicit Rules. (line 6)
-* rule, implicit, and directory search: Implicit/Search. (line 6)
-* rule, implicit, and VPATH: Implicit/Search. (line 6)
-* rule, implicit, chains of: Chained Rules. (line 6)
-* rule, implicit, definition of: Makefile Contents. (line 16)
-* rule, implicit, how to use: Using Implicit. (line 6)
-* rule, implicit, introduction to: make Deduces. (line 6)
-* rule, implicit, predefined: Catalogue of Rules. (line 6)
-* rule, introduction to: Rule Introduction. (line 6)
-* rule, multiple for one target: Multiple Rules. (line 6)
-* rule, no commands or prerequisites: Force Targets. (line 6)
-* rule, pattern: Pattern Intro. (line 6)
-* rule, static pattern: Static Pattern. (line 6)
-* rule, static pattern versus implicit: Static versus Implicit.
- (line 6)
-* rule, with multiple targets: Multiple Targets. (line 6)
-* rules, and $: Rule Syntax. (line 32)
-* s. (SCCS file prefix): Catalogue of Rules. (line 173)
-* SCCS, rule to extract from: Catalogue of Rules. (line 173)
-* search algorithm, implicit rule: Implicit Rule Search.
- (line 6)
-* search path for prerequisites (VPATH): Directory Search. (line 6)
-* search path for prerequisites (VPATH), and implicit rules: Implicit/Search.
- (line 6)
-* search path for prerequisites (VPATH), and link libraries: Libraries/Search.
- (line 6)
-* searching for strings: Text Functions. (line 103)
-* secondary expansion: Secondary Expansion. (line 6)
-* secondary expansion and explicit rules: Secondary Expansion.
- (line 106)
-* secondary expansion and implicit rules: Secondary Expansion.
- (line 146)
-* secondary expansion and static pattern rules: Secondary Expansion.
- (line 138)
-* secondary files: Chained Rules. (line 46)
-* secondary targets: Special Targets. (line 49)
-* sed (shell command): Automatic Prerequisites.
- (line 73)
-* selecting a word: Text Functions. (line 159)
-* selecting word lists: Text Functions. (line 168)
-* sequences of commands: Sequences. (line 6)
-* setting options from environment: Options/Recursion. (line 81)
-* setting options in makefiles: Options/Recursion. (line 81)
-* setting variables: Setting. (line 6)
-* several rules for one target: Multiple Rules. (line 6)
-* several targets in a rule: Multiple Targets. (line 6)
-* shar (standard target): Goals. (line 103)
-* shell command: Simple Makefile. (line 72)
-* shell command, and directory search: Commands/Search. (line 6)
-* shell command, execution: Execution. (line 6)
-* shell command, function for: Shell Function. (line 6)
-* shell file name pattern (in include): Include. (line 13)
-* shell variables, setting in commands: Execution. (line 10)
-* shell wildcards (in include): Include. (line 13)
-* shell, choosing the: Choosing the Shell. (line 6)
-* SHELL, exported value: Variables/Recursion. (line 23)
-* SHELL, import from environment: Environment. (line 37)
-* shell, in DOS and Windows: Choosing the Shell. (line 36)
-* SHELL, MS-DOS specifics: Choosing the Shell. (line 42)
-* SHELL, value of: Choosing the Shell. (line 6)
-* signal: Interrupts. (line 6)
-* silent operation: Echoing. (line 6)
-* simple makefile: Simple Makefile. (line 6)
-* simple variable expansion: Using Variables. (line 6)
-* simplifying with variables: Variables Simplify. (line 6)
-* simply expanded variables: Flavors. (line 56)
-* sorting words: Text Functions. (line 146)
-* spaces, in variable values: Flavors. (line 103)
-* spaces, stripping: Text Functions. (line 80)
-* special targets: Special Targets. (line 6)
-* special variables: Special Variables. (line 6)
-* specifying makefile name: Makefile Names. (line 30)
-* splitting commands: Splitting Lines. (line 6)
-* standard input: Parallel. (line 30)
-* standards conformance: Overview. (line 13)
-* standards for makefiles: Makefile Conventions.
- (line 6)
-* static pattern rule: Static Pattern. (line 6)
-* static pattern rule, syntax of: Static Usage. (line 6)
-* static pattern rule, versus implicit: Static versus Implicit.
- (line 6)
-* static pattern rules, secondary expansion of: Secondary Expansion.
- (line 138)
-* stem <1>: Pattern Match. (line 6)
-* stem: Static Usage. (line 17)
-* stem, variable for: Automatic Variables. (line 77)
-* stopping make: Make Control Functions.
- (line 11)
-* strings, searching for: Text Functions. (line 103)
-* stripping whitespace: Text Functions. (line 80)
-* sub-make: Variables/Recursion. (line 6)
-* subdirectories, recursion for: Recursion. (line 6)
-* substitution variable reference: Substitution Refs. (line 6)
-* suffix rule: Suffix Rules. (line 6)
-* suffix rule, for archive: Archive Suffix Rules.
- (line 6)
-* suffix, adding: File Name Functions. (line 68)
-* suffix, function to find: File Name Functions. (line 43)
-* suffix, substituting in variables: Substitution Refs. (line 6)
-* switches: Options Summary. (line 6)
-* symbol directories, updating archive: Archive Symbols. (line 6)
-* syntax of commands: Command Syntax. (line 6)
-* syntax of rules: Rule Syntax. (line 6)
-* tab character (in commands): Rule Syntax. (line 26)
-* tabs in rules: Rule Introduction. (line 21)
-* TAGS (standard target): Goals. (line 111)
-* tangle <1>: Implicit Variables. (line 104)
-* tangle: Catalogue of Rules. (line 151)
-* tar (standard target): Goals. (line 100)
-* target: Rules. (line 6)
-* target pattern, implicit: Pattern Intro. (line 9)
-* target pattern, static (not implicit): Static Usage. (line 17)
-* target, deleting on error: Errors. (line 64)
-* target, deleting on interrupt: Interrupts. (line 6)
-* target, expansion: Reading Makefiles. (line 62)
-* target, multiple in pattern rule: Pattern Intro. (line 49)
-* target, multiple rules for one: Multiple Rules. (line 6)
-* target, touching: Instead of Execution.
- (line 19)
-* target-specific variables: Target-specific. (line 6)
-* targets: Rule Syntax. (line 18)
-* targets without a file: Phony Targets. (line 6)
-* targets, built-in special: Special Targets. (line 6)
-* targets, empty: Empty Targets. (line 6)
-* targets, force: Force Targets. (line 6)
-* targets, introduction to: Rule Introduction. (line 8)
-* targets, multiple: Multiple Targets. (line 6)
-* targets, phony: Phony Targets. (line 6)
-* terminal rule: Match-Anything Rules.
- (line 6)
-* test (standard target): Goals. (line 115)
-* testing compilation: Testing. (line 6)
-* tex <1>: Implicit Variables. (line 91)
-* tex: Catalogue of Rules. (line 151)
-* TeX, rule to run: Catalogue of Rules. (line 151)
-* texi2dvi <1>: Implicit Variables. (line 95)
-* texi2dvi: Catalogue of Rules. (line 158)
-* Texinfo, rule to format: Catalogue of Rules. (line 158)
-* tilde (~): Wildcards. (line 11)
-* touch (shell command) <1>: Empty Targets. (line 25)
-* touch (shell command): Wildcard Examples. (line 21)
-* touching files: Instead of Execution.
- (line 19)
-* traditional directory search (GPATH): Search Algorithm. (line 42)
-* types of prerequisites: Prerequisite Types. (line 6)
-* undefined variables, warning message: Options Summary. (line 251)
-* updating archive symbol directories: Archive Symbols. (line 6)
-* updating makefiles: Remaking Makefiles. (line 6)
-* user defined functions: Call Function. (line 6)
-* value: Using Variables. (line 6)
-* value, how a variable gets it: Values. (line 6)
-* variable: Using Variables. (line 6)
-* variable definition: Makefile Contents. (line 22)
-* variable references in commands: Variables in Commands.
- (line 6)
-* variables: Variables Simplify. (line 6)
-* variables, $ in name: Computed Names. (line 6)
-* variables, and implicit rule: Automatic Variables. (line 6)
-* variables, appending to: Appending. (line 6)
-* variables, automatic: Automatic Variables. (line 6)
-* variables, command line: Overriding. (line 6)
-* variables, command line, and recursion: Options/Recursion. (line 17)
-* variables, computed names: Computed Names. (line 6)
-* variables, conditional assignment: Flavors. (line 129)
-* variables, defining verbatim: Defining. (line 6)
-* variables, environment <1>: Environment. (line 6)
-* variables, environment: Variables/Recursion. (line 6)
-* variables, exporting: Variables/Recursion. (line 6)
-* variables, flavor of: Flavor Function. (line 6)
-* variables, flavors: Flavors. (line 6)
-* variables, how they get their values: Values. (line 6)
-* variables, how to reference: Reference. (line 6)
-* variables, loops in expansion: Flavors. (line 44)
-* variables, modified reference: Substitution Refs. (line 6)
-* variables, nested references: Computed Names. (line 6)
-* variables, origin of: Origin Function. (line 6)
-* variables, overriding: Override Directive. (line 6)
-* variables, overriding with arguments: Overriding. (line 6)
-* variables, pattern-specific: Pattern-specific. (line 6)
-* variables, recursively expanded: Flavors. (line 6)
-* variables, setting: Setting. (line 6)
-* variables, simply expanded: Flavors. (line 56)
-* variables, spaces in values: Flavors. (line 103)
-* variables, substituting suffix in: Substitution Refs. (line 6)
-* variables, substitution reference: Substitution Refs. (line 6)
-* variables, target-specific: Target-specific. (line 6)
-* variables, unexpanded value: Value Function. (line 6)
-* variables, warning for undefined: Options Summary. (line 251)
-* varying prerequisites: Static Pattern. (line 6)
-* verbatim variable definition: Defining. (line 6)
-* vpath: Directory Search. (line 6)
-* VPATH, and implicit rules: Implicit/Search. (line 6)
-* VPATH, and link libraries: Libraries/Search. (line 6)
-* warnings, printing: Make Control Functions.
- (line 35)
-* weave <1>: Implicit Variables. (line 98)
-* weave: Catalogue of Rules. (line 151)
-* Web, rule to run: Catalogue of Rules. (line 151)
-* what if: Instead of Execution.
- (line 33)
-* whitespace, in variable values: Flavors. (line 103)
-* whitespace, stripping: Text Functions. (line 80)
-* wildcard: Wildcards. (line 6)
-* wildcard pitfalls: Wildcard Pitfall. (line 6)
-* wildcard, function: File Name Functions. (line 107)
-* wildcard, in archive member: Archive Members. (line 36)
-* wildcard, in include: Include. (line 13)
-* wildcards and MS-DOS/MS-Windows backslashes: Wildcard Pitfall.
- (line 31)
-* Windows, choosing a shell in: Choosing the Shell. (line 36)
-* word, selecting a: Text Functions. (line 159)
-* words, extracting first: Text Functions. (line 184)
-* words, extracting last: Text Functions. (line 197)
-* words, filtering: Text Functions. (line 114)
-* words, filtering out: Text Functions. (line 132)
-* words, finding number: Text Functions. (line 180)
-* words, iterating over: Foreach Function. (line 6)
-* words, joining lists: File Name Functions. (line 90)
-* words, removing duplicates: Text Functions. (line 155)
-* words, selecting lists of: Text Functions. (line 168)
-* writing rule commands: Commands. (line 6)
-* writing rules: Rules. (line 6)
-* yacc <1>: Implicit Variables. (line 75)
-* yacc <2>: Catalogue of Rules. (line 120)
-* yacc: Sequences. (line 18)
-* Yacc, rule to run: Catalogue of Rules. (line 120)
-* ~ (tilde): Wildcards. (line 11)
-
-
-File: make.info, Node: Name Index, Prev: Concept Index, Up: Top
-
-Index of Functions, Variables, & Directives
-*******************************************
-
-[index]
-* Menu:
-
-* $%: Automatic Variables. (line 37)
-* $(%D): Automatic Variables. (line 129)
-* $(%F): Automatic Variables. (line 130)
-* $(*D): Automatic Variables. (line 124)
-* $(*F): Automatic Variables. (line 125)
-* $(+D): Automatic Variables. (line 147)
-* $(+F): Automatic Variables. (line 148)
-* $(<D): Automatic Variables. (line 137)
-* $(<F): Automatic Variables. (line 138)
-* $(?D): Automatic Variables. (line 153)
-* $(?F): Automatic Variables. (line 154)
-* $(@D): Automatic Variables. (line 113)
-* $(@F): Automatic Variables. (line 119)
-* $(^D): Automatic Variables. (line 142)
-* $(^F): Automatic Variables. (line 143)
-* $*: Automatic Variables. (line 73)
-* $*, and static pattern: Static Usage. (line 81)
-* $+: Automatic Variables. (line 63)
-* $<: Automatic Variables. (line 43)
-* $?: Automatic Variables. (line 48)
-* $@: Automatic Variables. (line 30)
-* $^: Automatic Variables. (line 53)
-* $|: Automatic Variables. (line 69)
-* % (automatic variable): Automatic Variables. (line 37)
-* %D (automatic variable): Automatic Variables. (line 129)
-* %F (automatic variable): Automatic Variables. (line 130)
-* * (automatic variable): Automatic Variables. (line 73)
-* * (automatic variable), unsupported bizarre usage: Missing. (line 44)
-* *D (automatic variable): Automatic Variables. (line 124)
-* *F (automatic variable): Automatic Variables. (line 125)
-* + (automatic variable): Automatic Variables. (line 63)
-* +D (automatic variable): Automatic Variables. (line 147)
-* +F (automatic variable): Automatic Variables. (line 148)
-* .DEFAULT <1>: Last Resort. (line 23)
-* .DEFAULT: Special Targets. (line 20)
-* .DEFAULT, and empty commands: Empty Commands. (line 16)
-* .DEFAULT_GOAL (define default goal): Special Variables. (line 10)
-* .DELETE_ON_ERROR <1>: Errors. (line 64)
-* .DELETE_ON_ERROR: Special Targets. (line 67)
-* .EXPORT_ALL_VARIABLES <1>: Variables/Recursion. (line 99)
-* .EXPORT_ALL_VARIABLES: Special Targets. (line 129)
-* .FEATURES (list of supported features): Special Variables. (line 65)
-* .IGNORE <1>: Errors. (line 30)
-* .IGNORE: Special Targets. (line 74)
-* .INCLUDE_DIRS (list of include directories): Special Variables.
- (line 98)
-* .INTERMEDIATE: Special Targets. (line 43)
-* .LIBPATTERNS: Libraries/Search. (line 6)
-* .LOW_RESOLUTION_TIME: Special Targets. (line 86)
-* .NOTPARALLEL: Special Targets. (line 134)
-* .PHONY <1>: Special Targets. (line 8)
-* .PHONY: Phony Targets. (line 22)
-* .POSIX: Options/Recursion. (line 60)
-* .PRECIOUS <1>: Interrupts. (line 22)
-* .PRECIOUS: Special Targets. (line 28)
-* .SECONDARY: Special Targets. (line 48)
-* .SECONDEXPANSION <1>: Special Targets. (line 57)
-* .SECONDEXPANSION: Secondary Expansion. (line 6)
-* .SILENT <1>: Echoing. (line 24)
-* .SILENT: Special Targets. (line 116)
-* .SUFFIXES <1>: Suffix Rules. (line 61)
-* .SUFFIXES: Special Targets. (line 15)
-* .VARIABLES (list of variables): Special Variables. (line 56)
-* /usr/gnu/include: Include. (line 52)
-* /usr/include: Include. (line 52)
-* /usr/local/include: Include. (line 52)
-* < (automatic variable): Automatic Variables. (line 43)
-* <D (automatic variable): Automatic Variables. (line 137)
-* <F (automatic variable): Automatic Variables. (line 138)
-* ? (automatic variable): Automatic Variables. (line 48)
-* ?D (automatic variable): Automatic Variables. (line 153)
-* ?F (automatic variable): Automatic Variables. (line 154)
-* @ (automatic variable): Automatic Variables. (line 30)
-* @D (automatic variable): Automatic Variables. (line 113)
-* @F (automatic variable): Automatic Variables. (line 119)
-* ^ (automatic variable): Automatic Variables. (line 53)
-* ^D (automatic variable): Automatic Variables. (line 142)
-* ^F (automatic variable): Automatic Variables. (line 143)
-* abspath: File Name Functions. (line 121)
-* addprefix: File Name Functions. (line 79)
-* addsuffix: File Name Functions. (line 68)
-* and: Conditional Functions.
- (line 45)
-* AR: Implicit Variables. (line 41)
-* ARFLAGS: Implicit Variables. (line 117)
-* AS: Implicit Variables. (line 44)
-* ASFLAGS: Implicit Variables. (line 120)
-* basename: File Name Functions. (line 57)
-* bindir: Directory Variables. (line 53)
-* call: Call Function. (line 6)
-* CC: Implicit Variables. (line 47)
-* CFLAGS: Implicit Variables. (line 124)
-* CO: Implicit Variables. (line 50)
-* COFLAGS: Implicit Variables. (line 130)
-* COMSPEC: Choosing the Shell. (line 39)
-* CPP: Implicit Variables. (line 59)
-* CPPFLAGS: Implicit Variables. (line 133)
-* CTANGLE: Implicit Variables. (line 107)
-* CURDIR: Recursion. (line 28)
-* CWEAVE: Implicit Variables. (line 101)
-* CXX: Implicit Variables. (line 53)
-* CXXFLAGS: Implicit Variables. (line 127)
-* define: Defining. (line 6)
-* dir: File Name Functions. (line 17)
-* else: Conditional Syntax. (line 6)
-* endef: Defining. (line 6)
-* endif: Conditional Syntax. (line 6)
-* error: Make Control Functions.
- (line 11)
-* eval: Eval Function. (line 6)
-* exec_prefix: Directory Variables. (line 35)
-* export: Variables/Recursion. (line 40)
-* FC: Implicit Variables. (line 63)
-* FFLAGS: Implicit Variables. (line 137)
-* filter: Text Functions. (line 114)
-* filter-out: Text Functions. (line 132)
-* findstring: Text Functions. (line 103)
-* firstword: Text Functions. (line 184)
-* flavor: Flavor Function. (line 6)
-* foreach: Foreach Function. (line 6)
-* GET: Implicit Variables. (line 67)
-* GFLAGS: Implicit Variables. (line 140)
-* GNUmakefile: Makefile Names. (line 7)
-* GPATH: Search Algorithm. (line 48)
-* if: Conditional Functions.
- (line 6)
-* ifdef: Conditional Syntax. (line 6)
-* ifeq: Conditional Syntax. (line 6)
-* ifndef: Conditional Syntax. (line 6)
-* ifneq: Conditional Syntax. (line 6)
-* include: Include. (line 6)
-* info: Make Control Functions.
- (line 43)
-* join: File Name Functions. (line 90)
-* lastword: Text Functions. (line 197)
-* LDFLAGS: Implicit Variables. (line 143)
-* LEX: Implicit Variables. (line 70)
-* LFLAGS: Implicit Variables. (line 147)
-* libexecdir: Directory Variables. (line 66)
-* LINT: Implicit Variables. (line 78)
-* LINTFLAGS: Implicit Variables. (line 159)
-* M2C: Implicit Variables. (line 81)
-* MAKE <1>: Flavors. (line 84)
-* MAKE: MAKE Variable. (line 6)
-* MAKE_RESTARTS (number of times make has restarted): Special Variables.
- (line 49)
-* MAKE_VERSION: Features. (line 197)
-* MAKECMDGOALS: Goals. (line 30)
-* makefile: Makefile Names. (line 7)
-* Makefile: Makefile Names. (line 7)
-* MAKEFILE_LIST: MAKEFILE_LIST Variable.
- (line 6)
-* MAKEFILES <1>: Variables/Recursion. (line 127)
-* MAKEFILES: MAKEFILES Variable. (line 6)
-* MAKEFLAGS: Options/Recursion. (line 6)
-* MAKEINFO: Implicit Variables. (line 87)
-* MAKELEVEL <1>: Flavors. (line 84)
-* MAKELEVEL: Variables/Recursion. (line 115)
-* MAKEOVERRIDES: Options/Recursion. (line 49)
-* MAKESHELL (MS-DOS alternative to SHELL): Choosing the Shell.
- (line 25)
-* MFLAGS: Options/Recursion. (line 65)
-* notdir: File Name Functions. (line 27)
-* or: Conditional Functions.
- (line 37)
-* origin: Origin Function. (line 6)
-* OUTPUT_OPTION: Catalogue of Rules. (line 202)
-* override: Override Directive. (line 6)
-* patsubst <1>: Text Functions. (line 18)
-* patsubst: Substitution Refs. (line 28)
-* PC: Implicit Variables. (line 84)
-* PFLAGS: Implicit Variables. (line 153)
-* prefix: Directory Variables. (line 25)
-* realpath: File Name Functions. (line 114)
-* RFLAGS: Implicit Variables. (line 156)
-* RM: Implicit Variables. (line 110)
-* sbindir: Directory Variables. (line 59)
-* shell: Shell Function. (line 6)
-* SHELL: Choosing the Shell. (line 6)
-* SHELL (command execution): Execution. (line 6)
-* sort: Text Functions. (line 146)
-* strip: Text Functions. (line 80)
-* subst <1>: Text Functions. (line 9)
-* subst: Multiple Targets. (line 28)
-* suffix: File Name Functions. (line 43)
-* SUFFIXES: Suffix Rules. (line 81)
-* TANGLE: Implicit Variables. (line 104)
-* TEX: Implicit Variables. (line 91)
-* TEXI2DVI: Implicit Variables. (line 94)
-* unexport: Variables/Recursion. (line 45)
-* value: Value Function. (line 6)
-* vpath: Selective Search. (line 6)
-* VPATH: General Search. (line 6)
-* vpath: Directory Search. (line 6)
-* VPATH: Directory Search. (line 6)
-* warning: Make Control Functions.
- (line 35)
-* WEAVE: Implicit Variables. (line 98)
-* wildcard <1>: File Name Functions. (line 107)
-* wildcard: Wildcard Function. (line 6)
-* word: Text Functions. (line 159)
-* wordlist: Text Functions. (line 168)
-* words: Text Functions. (line 180)
-* YACC: Implicit Variables. (line 74)
-* YFLAGS: Implicit Variables. (line 150)
-* | (automatic variable): Automatic Variables. (line 69)
-
-
diff -rNU3 dist.orig/doc/make.texi dist/doc/make.texi
--- dist.orig/doc/make.texi 2006-04-01 08:36:40.000000000 +0200
+++ dist/doc/make.texi 2014-08-18 08:47:47.000000000 +0200
@@ -4,7 +4,7 @@
@include version.texi
@set EDITION 0.70
-@set RCSID $Id: make.texi,v 1.45 2006/04/01 06:36:40 psmith Exp $
+@set RCSID $Id: make.texi,v 1.1.1.1 2014/08/18 06:47:47 christos Exp $
@settitle GNU @code{make}
@setchapternewpage odd
diff -rNU3 dist.orig/po/Makefile.in.in dist/po/Makefile.in.in
--- dist.orig/po/Makefile.in.in 2006-04-01 08:39:51.000000000 +0200
+++ dist/po/Makefile.in.in 2014-08-18 08:57:25.000000000 +0200
@@ -13,7 +13,7 @@
PACKAGE = @PACKAGE@
VERSION = @VERSION@
-SHELL = /bin/sh
+SHELL = @SHELL@
@SET_MAKE@
srcdir = @srcdir@
diff -rNU3 dist.orig/tests/scripts/functions/foreach dist/tests/scripts/functions/foreach
--- dist.orig/tests/scripts/functions/foreach 2006-03-10 03:20:46.000000000 +0100
+++ dist/tests/scripts/functions/foreach 2014-08-18 08:47:57.000000000 +0200
@@ -1,5 +1,5 @@
# -*-perl-*-
-# $Id: foreach,v 1.5 2006/03/10 02:20:46 psmith Exp $
+# $Id: foreach,v 1.1.1.1 2014/08/18 06:47:57 christos Exp $
$description = "Test the foreach function.";
diff -rNU3 dist.orig/tests/test_driver.pl dist/tests/test_driver.pl
--- dist.orig/tests/test_driver.pl 2006-03-10 03:20:45.000000000 +0100
+++ dist/tests/test_driver.pl 2014-08-18 08:47:57.000000000 +0200
@@ -28,7 +28,7 @@
# this routine controls the whole mess; each test suite sets up a few
# variables and then calls &toplevel, which does all the real work.
-# $Id: test_driver.pl,v 1.19 2006/03/10 02:20:45 psmith Exp $
+# $Id: test_driver.pl,v 1.1.1.1 2014/08/18 06:47:57 christos Exp $
# The number of test categories we've run
diff -rNU3 dist.orig/w32/include/sub_proc.h dist/w32/include/sub_proc.h
--- dist.orig/w32/include/sub_proc.h 2006-02-11 23:16:05.000000000 +0100
+++ dist/w32/include/sub_proc.h 2014-08-18 08:47:56.000000000 +0200
@@ -21,11 +21,11 @@
/*
* Component Name:
*
- * $Date: 2006/02/11 22:16:05 $
+ * $Date: 2014/08/18 06:47:56 $
*
- * $Source: /sources/make/make/w32/include/sub_proc.h,v $
+ * $Source: /cvsroot/src/external/gpl2/gmake/dist/w32/include/sub_proc.h,v $
*
- * $Id: sub_proc.h,v 1.8 2006/02/11 22:16:05 psmith Exp $
+ * $Id: sub_proc.h,v 1.1.1.1 2014/08/18 06:47:56 christos Exp $
*/
#define EXTERN_DECL(entry, args) extern entry args
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