diff --git a/lib/hash.c b/lib/hash.c index 918aa0d..e06a235 100644 --- a/lib/hash.c +++ b/lib/hash.c @@ -1,6 +1,6 @@ /* hash - hashing table processing. - Copyright (C) 1998-2004, 2006-2007, 2009-2023 Free Software Foundation, Inc. + Copyright (C) 1998-2004, 2006-2007, 2009-2025 Free Software Foundation, Inc. Written by Jim Meyering, 1992. @@ -29,6 +29,7 @@ #include "bitrotate.h" #include "xalloc-oversized.h" +#include #include #include #include @@ -499,13 +500,17 @@ compute_bucket_size (size_t candidate, const Hash_tuning *tuning) { float new_candidate = candidate / tuning->growth_threshold; if ((float) SIZE_MAX <= new_candidate) - return 0; + goto nomem; candidate = new_candidate; } candidate = next_prime (candidate); if (xalloc_oversized (candidate, sizeof (struct hash_entry *))) - return 0; + goto nomem; return candidate; + + nomem: + errno = ENOMEM; + return 0; } Hash_table * @@ -534,6 +539,7 @@ hash_initialize (size_t candidate, const Hash_tuning *tuning, if the user provides invalid tuning options, we silently revert to using the defaults, and ignore further request to change the tuning options. */ + errno = EINVAL; goto fail; } @@ -607,6 +613,7 @@ hash_free (Hash_table *table) struct hash_entry *bucket; struct hash_entry *cursor; struct hash_entry *next; + int err = errno; /* Call the user data_freer function. */ if (table->data_freer && table->n_entries) @@ -649,6 +656,8 @@ hash_free (Hash_table *table) /* Free the remainder of the hash table structure. */ free (table->bucket); free (table); + + errno = err; } /* Insertion and deletion. */ @@ -762,8 +771,8 @@ hash_find_entry (Hash_table *table, const void *entry, /* Internal helper, to move entries from SRC to DST. Both tables must share the same free entry list. If SAFE, only move overflow entries, saving bucket heads for later, so that no allocations will - occur. Return false if the free entry list is exhausted and an - allocation fails. */ + occur. Return false (setting errno) if the free entry list is + exhausted and an allocation fails. */ static bool transfer_entries (Hash_table *dst, Hash_table *src, bool safe) @@ -910,12 +919,14 @@ hash_rehash (Hash_table *table, size_t candidate) passes. Two passes give worse cache performance and takes longer, but at this point, we're already out of memory, so slow and safe is better than failure. */ + int err = errno; table->free_entry_list = new_table->free_entry_list; if (! (transfer_entries (table, new_table, true) && transfer_entries (table, new_table, false))) abort (); /* table->n_entries already holds its value. */ free (new_table->bucket); + errno = err; return false; } @@ -962,7 +973,10 @@ hash_insert_if_absent (Hash_table *table, void const *entry, * tuning->growth_threshold)); if ((float) SIZE_MAX <= candidate) - return -1; + { + errno = ENOMEM; + return -1; + } /* If the rehash fails, arrange to return NULL. */ if (!hash_rehash (table, candidate)) diff --git a/lib/hash.h b/lib/hash.h index 5535ceb..5c90b4d 100644 --- a/lib/hash.h +++ b/lib/hash.h @@ -1,5 +1,5 @@ /* hash - hashing table processing. - Copyright (C) 1998-1999, 2001, 2003, 2009-2023 Free Software Foundation, + Copyright (C) 1998-1999, 2001, 2003, 2009-2025 Free Software Foundation, Inc. Written by Jim Meyering , 1998. @@ -61,24 +61,24 @@ typedef struct hash_table Hash_table; number of buckets (used plus unused), or the maximum number of slots, are the same quantity. */ extern size_t hash_get_n_buckets (const Hash_table *table) - ; + _GL_ATTRIBUTE_PURE; /* Return the number of slots in use (non-empty buckets). */ extern size_t hash_get_n_buckets_used (const Hash_table *table) - ; + _GL_ATTRIBUTE_PURE; /* Return the number of active entries. */ extern size_t hash_get_n_entries (const Hash_table *table) - ; + _GL_ATTRIBUTE_PURE; /* Return the length of the longest chain (bucket). */ extern size_t hash_get_max_bucket_length (const Hash_table *table) - ; + _GL_ATTRIBUTE_PURE; /* Do a mild validation of a hash table, by traversing it and checking two statistics. */ extern bool hash_table_ok (const Hash_table *table) - ; + _GL_ATTRIBUTE_PURE; extern void hash_print_statistics (const Hash_table *table, FILE *stream); @@ -99,7 +99,7 @@ extern void *hash_lookup (const Hash_table *table, const void *entry); /* Return the first data in the table, or NULL if the table is empty. */ extern void *hash_get_first (const Hash_table *table) - ; + _GL_ATTRIBUTE_PURE; /* Return the user data for the entry following ENTRY, where ENTRY has been returned by a previous call to either 'hash_get_first' or 'hash_get_next'. @@ -124,25 +124,40 @@ typedef bool (*Hash_processor) (void *entry, void *processor_data); extern size_t hash_do_for_each (const Hash_table *table, Hash_processor processor, void *processor_data); +/* Return a hash index for a NUL-terminated STRING between 0 and N_BUCKETS-1. + This is a convenience routine for constructing other hashing functions. */ +extern size_t hash_string (const char *string, size_t n_buckets) + _GL_ATTRIBUTE_PURE; + +/* Return a hash code of ENTRY, in the range 0..TABLE_SIZE-1. + This hash code function must have the property that if the comparator of + ENTRY1 and ENTRY2 returns true, the hasher returns the same value for ENTRY1 + and for ENTRY2. + The hash code function typically computes an unsigned integer and at the end + performs a % TABLE_SIZE modulo operation. This modulo operation is performed + as part of this hash code function, not by the caller, because in some cases + the unsigned integer will be a 'size_t', in other cases an 'uintmax_t' or + even larger. */ +typedef size_t (*Hash_hasher) (const void *entry, size_t table_size); + +/* Compare two entries, ENTRY1 (being looked up or being inserted) and + ENTRY2 (already in the table) for equality. Return true for equal, + false otherwise. */ +typedef bool (*Hash_comparator) (const void *entry1, const void *entry2); + +/* This function is invoked when an ENTRY is removed from the hash table. */ +typedef void (*Hash_data_freer) (void *entry); + /* * Allocation and clean-up. */ -/* Return a hash index for a NUL-terminated STRING between 0 and N_BUCKETS-1. - This is a convenience routine for constructing other hashing functions. */ -extern size_t hash_string (const char *string, size_t n_buckets) - ; - extern void hash_reset_tuning (Hash_tuning *tuning); -typedef size_t (*Hash_hasher) (const void *entry, size_t table_size); -typedef bool (*Hash_comparator) (const void *entry1, const void *entry2); -typedef void (*Hash_data_freer) (void *entry); - /* Reclaim all storage associated with a hash table. If a data_freer function has been supplied by the user when the hash table was created, this function applies it to the data of each entry before freeing that - entry. */ + entry. This function preserves errno, like 'free'. */ extern void hash_free (Hash_table *table); /* Allocate and return a new hash table, or NULL upon failure. The initial @@ -177,23 +192,30 @@ extern void hash_free (Hash_table *table); You should specify this function only if you want these functions to free all of your 'data' data. This is typically the case when your data is simply an auxiliary struct that you have malloc'd to aggregate several - values. */ + values. + + Set errno on failure; otherwise errno is unspecified. */ +_GL_ATTRIBUTE_NODISCARD extern Hash_table *hash_initialize (size_t candidate, const Hash_tuning *tuning, Hash_hasher hasher, Hash_comparator comparator, - Hash_data_freer data_freer); + Hash_data_freer data_freer) + _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC (hash_free, 1); -/* Same as hash_initialize, but invokes xalloc_die on memory exhaustion. */ +/* Like hash_initialize, but invokes xalloc_die instead of returning NULL. */ /* This function is defined by module 'xhash'. */ +_GL_ATTRIBUTE_NODISCARD extern Hash_table *hash_xinitialize (size_t candidate, const Hash_tuning *tuning, Hash_hasher hasher, Hash_comparator comparator, - Hash_data_freer data_freer); + Hash_data_freer data_freer) + _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC (hash_free, 1) + _GL_ATTRIBUTE_RETURNS_NONNULL; /* Make all buckets empty, placing any chained entries on the free list. - Apply the user-specified function data_freer (if any) to the datas of any + Apply the user-specified function data_freer (if any) to the data of any affected entries. */ extern void hash_clear (Hash_table *table); @@ -207,23 +229,26 @@ extern void hash_clear (Hash_table *table); the table may receive at least CANDIDATE different user entries, including those already in the table, before any other growth of the hash table size occurs. If TUNING->IS_N_BUCKETS is true, then CANDIDATE specifies the - exact number of buckets desired. Return true iff the rehash succeeded. */ + exact number of buckets desired. Return true iff the rehash succeeded, + false (setting errno) otherwise. */ +_GL_ATTRIBUTE_NODISCARD extern bool hash_rehash (Hash_table *table, size_t candidate); /* If ENTRY matches an entry already in the hash table, return the pointer to the entry from the table. Otherwise, insert ENTRY and return ENTRY. - Return NULL if the storage required for insertion cannot be allocated. - This implementation does not support duplicate entries or insertion of - NULL. */ + Return NULL (setting errno) if the storage required for insertion + cannot be allocated. This implementation does not support + duplicate entries or insertion of NULL. */ +_GL_ATTRIBUTE_NODISCARD extern void *hash_insert (Hash_table *table, const void *entry); -/* Same as hash_insert, but invokes xalloc_die on memory exhaustion. */ +/* Same as hash_insert, but invokes xalloc_die instead of returning NULL. */ /* This function is defined by module 'xhash'. */ extern void *hash_xinsert (Hash_table *table, const void *entry); /* Insert ENTRY into hash TABLE if there is not already a matching entry. - Return -1 upon memory allocation failure. + Return -1 (setting errno) upon memory allocation failure. Return 1 if insertion succeeded. Return 0 if there is already a matching entry in the table, and in that case, if MATCHED_ENT is non-NULL, set *MATCHED_ENT @@ -247,6 +272,7 @@ extern void *hash_remove (Hash_table *table, const void *entry); /* Same as hash_remove. This interface is deprecated. FIXME: Remove in 2022. */ +_GL_ATTRIBUTE_DEPRECATED extern void *hash_delete (Hash_table *table, const void *entry); # ifdef __cplusplus diff --git a/m4/00gnulib.m4 b/m4/00gnulib.m4 index e3e0fb6..2b205b3 100644 --- a/m4/00gnulib.m4 +++ b/m4/00gnulib.m4 @@ -1,43 +1,84 @@ -# 00gnulib.m4 serial 3 -dnl Copyright (C) 2009-2019 Free Software Foundation, Inc. +# 00gnulib.m4 +# serial 9 +dnl Copyright (C) 2009-2025 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. +dnl This file is offered as-is, without any warranty. dnl This file must be named something that sorts before all other -dnl gnulib-provided .m4 files. It is needed until such time as we can -dnl assume Autoconf 2.64, with its improved AC_DEFUN_ONCE and -dnl m4_divert semantics. +dnl gnulib-provided .m4 files. It is needed until the clang fix has +dnl been included in Autoconf. -# Until autoconf 2.63, handling of the diversion stack required m4_init -# to be called first; but this does not happen with aclocal. Wrapping -# the entire execution in another layer of the diversion stack fixes this. -# Worse, prior to autoconf 2.62, m4_wrap depended on the underlying m4 -# for whether it was FIFO or LIFO; in order to properly balance with -# m4_init, we need to undo our push just before anything wrapped within -# the m4_init body. The way to ensure this is to wrap both sides of -# m4_init with a one-shot macro that does the pop at the right time. -m4_ifndef([_m4_divert_diversion], -[m4_divert_push([KILL]) -m4_define([gl_divert_fixup], [m4_divert_pop()m4_define([$0])]) -m4_define([m4_init], - [gl_divert_fixup()]m4_defn([m4_init])[gl_divert_fixup()])]) - - -# AC_DEFUN_ONCE([NAME], VALUE) -# ---------------------------- -# Define NAME to expand to VALUE on the first use (whether by direct -# expansion, or by AC_REQUIRE), and to nothing on all subsequent uses. -# Avoid bugs in AC_REQUIRE in Autoconf 2.63 and earlier. This -# definition is slower than the version in Autoconf 2.64, because it -# can only use interfaces that existed since 2.59; but it achieves the -# same effect. Quoting is necessary to avoid confusing Automake. -m4_version_prereq([2.63.263], [], -[m4_define([AC][_DEFUN_ONCE], - [AC][_DEFUN([$1], - [AC_REQUIRE([_gl_DEFUN_ONCE([$1])], - [m4_indir([_gl_DEFUN_ONCE([$1])])])])]dnl -[AC][_DEFUN([_gl_DEFUN_ONCE([$1])], [$2])])]) +# The following definitions arrange to use a compiler option +# -Werror=implicit-function-declaration in AC_CHECK_DECL, when the +# compiler is clang. Without it, clang implicitly declares "known" +# library functions in C mode, but not in C++ mode, which would cause +# Gnulib to omit a declaration and thus later produce an error in C++ +# mode. As of clang 9.0, these "known" functions are identified through +# LIBBUILTIN invocations in the LLVM source file +# llvm/tools/clang/include/clang/Basic/Builtins.def. +# It's not possible to AC_REQUIRE the extra tests from AC_CHECK_DECL, +# because AC_CHECK_DECL, like other Autoconf built-ins, is not supposed +# to AC_REQUIRE anything: some configure.ac files have their first +# AC_CHECK_DECL executed conditionally. Therefore append the extra tests +# to AC_PROG_CC. +AC_DEFUN([gl_COMPILER_CLANG], +[ +dnl AC_REQUIRE([AC_PROG_CC]) + AC_CACHE_CHECK([whether the compiler is clang], + [gl_cv_compiler_clang], + [dnl Use _AC_COMPILE_IFELSE instead of AC_EGREP_CPP, to avoid error + dnl "circular dependency of AC_LANG_COMPILER(C)" if AC_PROG_CC has + dnl not yet been invoked. + _AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM([[ + #ifdef __clang__ + barfbarf + #endif + ]],[[]]) + ], + [gl_cv_compiler_clang=no], + [gl_cv_compiler_clang=yes]) + ]) +]) +AC_DEFUN([gl_COMPILER_PREPARE_CHECK_DECL], +[ +dnl AC_REQUIRE([AC_PROG_CC]) +dnl AC_REQUIRE([gl_COMPILER_CLANG]) + AC_CACHE_CHECK([for compiler option needed when checking for declarations], + [gl_cv_compiler_check_decl_option], + [if test $gl_cv_compiler_clang = yes; then + dnl Test whether the compiler supports the option + dnl '-Werror=implicit-function-declaration'. + saved_ac_compile="$ac_compile" + ac_compile="$ac_compile -Werror=implicit-function-declaration" + dnl Use _AC_COMPILE_IFELSE instead of AC_COMPILE_IFELSE, to avoid a + dnl warning "AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS". + _AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]],[[]])], + [gl_cv_compiler_check_decl_option='-Werror=implicit-function-declaration'], + [gl_cv_compiler_check_decl_option=none]) + ac_compile="$saved_ac_compile" + else + gl_cv_compiler_check_decl_option=none + fi + ]) + if test "x$gl_cv_compiler_check_decl_option" != xnone; then + ac_compile_for_check_decl="$ac_compile $gl_cv_compiler_check_decl_option" + else + ac_compile_for_check_decl="$ac_compile" + fi +]) +dnl Redefine _AC_CHECK_DECL_BODY so that it references ac_compile_for_check_decl +dnl instead of ac_compile. If, for whatever reason, the override of AC_PROG_CC +dnl in zzgnulib.m4 is inactive, use the original ac_compile. +m4_define([_AC_CHECK_DECL_BODY], +[ ac_saved_ac_compile="$ac_compile" + if test -n "$ac_compile_for_check_decl"; then + ac_compile="$ac_compile_for_check_decl" + fi] +m4_defn([_AC_CHECK_DECL_BODY])[ ac_compile="$ac_saved_ac_compile" +]) # gl_00GNULIB # ----------- diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4 index 57b94ed..d5bf2fb 100644 --- a/m4/gnulib-common.m4 +++ b/m4/gnulib-common.m4 @@ -1,8 +1,10 @@ -# gnulib-common.m4 serial 44 -dnl Copyright (C) 2007-2019 Free Software Foundation, Inc. +# gnulib-common.m4 +# serial 110 +dnl Copyright (C) 2007-2025 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. +dnl This file is offered as-is, without any warranty. AC_PREREQ([2.62]) @@ -12,20 +14,76 @@ AC_DEFUN([gl_COMMON], [ dnl Use AC_REQUIRE here, so that the code is expanded once only. AC_REQUIRE([gl_00GNULIB]) AC_REQUIRE([gl_COMMON_BODY]) + AC_REQUIRE([gl_ZZGNULIB]) ]) AC_DEFUN([gl_COMMON_BODY], [ + AH_VERBATIM([0witness], +[/* Witness that has been included. */ +#define _GL_CONFIG_H_INCLUDED 1 +]) + dnl Avoid warnings from gcc -Wtrailing-whitespace. + dnl This is a temporary workaround until Autoconf fixes it. + dnl Test case: + dnl empty1=; empty2=; AC_DEFINE_UNQUOTED([FOO], [$empty1$empty2], [...]) + dnl should produce "#define FOO /**/", not "#define FOO ". + AH_TOP([#if defined __GNUC__ && __GNUC__ >= 15 && !defined __clang__ +# pragma GCC diagnostic push +# pragma GCC diagnostic ignored "-Wtrailing-whitespace" +#endif +]) + AH_BOTTOM([#if defined __GNUC__ && __GNUC__ >= 15 && !defined __clang__ +# pragma GCC diagnostic pop +#endif +]) + AH_VERBATIM([_GL_GNUC_PREREQ], +[/* True if the compiler says it groks GNU C version MAJOR.MINOR. + Except that + - clang groks GNU C 4.2, even on Windows, where it does not define + __GNUC__. + - The OpenMandriva-modified clang compiler pretends that it groks + GNU C version 13.1, but it doesn't: It does not support + __attribute__ ((__malloc__ (f, i))), nor does it support + __attribute__ ((__warning__ (message))) on a function redeclaration. + - Users can make clang lie as well, through the -fgnuc-version option. */ +#if defined __GNUC__ && defined __GNUC_MINOR__ && !defined __clang__ +# define _GL_GNUC_PREREQ(major, minor) \ + ((major) < __GNUC__ + ((minor) <= __GNUC_MINOR__)) +#elif defined __clang__ + /* clang really only groks GNU C 4.2. */ +# define _GL_GNUC_PREREQ(major, minor) \ + ((major) < 4 + ((minor) <= 2)) +#else +# define _GL_GNUC_PREREQ(major, minor) 0 +#endif +]) AH_VERBATIM([_Noreturn], [/* The _Noreturn keyword of C11. */ #ifndef _Noreturn # if (defined __cplusplus \ && ((201103 <= __cplusplus && !(__GNUC__ == 4 && __GNUC_MINOR__ == 7)) \ - || (defined _MSC_VER && 1900 <= _MSC_VER))) + || (defined _MSC_VER && 1900 <= _MSC_VER)) \ + && 0) + /* [[noreturn]] is not practically usable, because with it the syntax + extern _Noreturn void func (...); + would not be valid; such a declaration would only be valid with 'extern' + and '_Noreturn' swapped, or without the 'extern' keyword. However, some + AIX system header files and several gnulib header files use precisely + this syntax with 'extern'. */ # define _Noreturn [[noreturn]] +# elif (defined __clang__ && __clang_major__ < 16 \ + && defined _GL_WORK_AROUND_LLVM_BUG_59792) + /* Compile with -D_GL_WORK_AROUND_LLVM_BUG_59792 to work around + that rare LLVM bug, though you may get many false-alarm warnings. */ +# define _Noreturn # elif ((!defined __cplusplus || defined __clang__) \ - && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) \ - || 4 < __GNUC__ + (7 <= __GNUC_MINOR__))) + && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) \ + || (!defined __STRICT_ANSI__ \ + && (_GL_GNUC_PREREQ (4, 7) \ + || (defined __apple_build_version__ \ + ? 6000000 <= __apple_build_version__ \ + : 3 < __clang_major__ + (5 <= __clang_minor__)))))) /* _Noreturn works as-is. */ -# elif 2 < __GNUC__ + (8 <= __GNUC_MINOR__) || 0x5110 <= __SUNPRO_C +# elif _GL_GNUC_PREREQ (2, 8) || defined __clang__ || 0x5110 <= __SUNPRO_C # define _Noreturn __attribute__ ((__noreturn__)) # elif 1200 <= (defined _MSC_VER ? _MSC_VER : 0) # define _Noreturn __declspec (noreturn) @@ -44,48 +102,820 @@ AC_DEFUN([gl_COMMON_BODY], [ #if defined __APPLE__ && defined __MACH__ && __APPLE_CC__ >= 5465 && !defined __cplusplus && __STDC_VERSION__ >= 199901L && !defined __GNUC_STDC_INLINE__ # define __GNUC_STDC_INLINE__ 1 #endif]) - AH_VERBATIM([unused_parameter], -[/* Define as a marker that can be attached to declarations that might not - be used. This helps to reduce warnings, such as from - GCC -Wunused-parameter. */ -#if __GNUC__ >= 3 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7) -# define _GL_UNUSED __attribute__ ((__unused__)) -#else -# define _GL_UNUSED -#endif -/* The name _UNUSED_PARAMETER_ is an earlier spelling, although the name - is a misnomer outside of parameter lists. */ -#define _UNUSED_PARAMETER_ _GL_UNUSED - -/* gcc supports the "unused" attribute on possibly unused labels, and - g++ has since version 4.5. Note to support C++ as well as C, - _GL_UNUSED_LABEL should be used with a trailing ; */ -#if !defined __cplusplus || __GNUC__ > 4 \ - || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5) -# define _GL_UNUSED_LABEL _GL_UNUSED -#else -# define _GL_UNUSED_LABEL + AH_VERBATIM([attribute], +[/* Attributes. */ +/* Define _GL_HAS_ATTRIBUTE only once, because on FreeBSD, with gcc < 5, if + gets included once again after , __has_attribute(x) + expands to 0 always, and redefining _GL_HAS_ATTRIBUTE would turn off all + attributes. */ +#ifndef _GL_HAS_ATTRIBUTE +# if (defined __has_attribute \ + && (!defined __clang_minor__ \ + || (defined __apple_build_version__ \ + ? 7000000 <= __apple_build_version__ \ + : 5 <= __clang_major__))) +# define _GL_HAS_ATTRIBUTE(attr) __has_attribute (__##attr##__) +# else +# define _GL_HAS_ATTRIBUTE(attr) _GL_ATTR_##attr +/* The following lines list the first GCC version that supports the attribute. + Although the lines are not used in GCC 5 and later (as GCC 5 introduced + __has_attribute support), list GCC versions 5+ anyway for completeness. */ +# define _GL_ATTR_alloc_size _GL_GNUC_PREREQ (4, 3) +# define _GL_ATTR_always_inline _GL_GNUC_PREREQ (3, 2) +# define _GL_ATTR_artificial _GL_GNUC_PREREQ (4, 3) +# define _GL_ATTR_cold _GL_GNUC_PREREQ (4, 3) +# define _GL_ATTR_const _GL_GNUC_PREREQ (2, 95) +# define _GL_ATTR_deprecated _GL_GNUC_PREREQ (3, 1) +# define _GL_ATTR_diagnose_if 0 +# define _GL_ATTR_error _GL_GNUC_PREREQ (4, 3) +# define _GL_ATTR_externally_visible _GL_GNUC_PREREQ (4, 1) +# define _GL_ATTR_fallthrough _GL_GNUC_PREREQ (7, 0) +# define _GL_ATTR_format _GL_GNUC_PREREQ (2, 7) +# define _GL_ATTR_leaf _GL_GNUC_PREREQ (4, 6) +# define _GL_ATTR_malloc _GL_GNUC_PREREQ (3, 0) +# ifdef _ICC +# define _GL_ATTR_may_alias 0 +# else +# define _GL_ATTR_may_alias _GL_GNUC_PREREQ (3, 3) +# endif +# define _GL_ATTR_noinline _GL_GNUC_PREREQ (3, 1) +# define _GL_ATTR_nonnull _GL_GNUC_PREREQ (3, 3) +# define _GL_ATTR_nonnull_if_nonzero _GL_GNUC_PREREQ (15, 1) +# define _GL_ATTR_nonstring _GL_GNUC_PREREQ (8, 0) +# define _GL_ATTR_nothrow _GL_GNUC_PREREQ (3, 3) +# define _GL_ATTR_packed _GL_GNUC_PREREQ (2, 7) +# define _GL_ATTR_pure _GL_GNUC_PREREQ (2, 96) +# define _GL_ATTR_reproducible _GL_GNUC_PREREQ (15, 1) +# define _GL_ATTR_returns_nonnull _GL_GNUC_PREREQ (4, 9) +# define _GL_ATTR_sentinel _GL_GNUC_PREREQ (4, 0) +# define _GL_ATTR_unsequenced _GL_GNUC_PREREQ (15, 1) +# define _GL_ATTR_unused _GL_GNUC_PREREQ (2, 7) +# define _GL_ATTR_warn_unused_result _GL_GNUC_PREREQ (3, 4) +# endif #endif -/* The __pure__ attribute was added in gcc 2.96. */ -#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96) -# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__)) +/* Use __has_c_attribute if available. However, do not use with + pre-C23 GCC, which can issue false positives if -Wpedantic. */ +#if (defined __has_c_attribute \ + && ! (_GL_GNUC_PREREQ (4, 6) \ + && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) <= 201710)) +# define _GL_HAVE___HAS_C_ATTRIBUTE 1 #else -# define _GL_ATTRIBUTE_PURE /* empty */ +# define _GL_HAVE___HAS_C_ATTRIBUTE 0 #endif -/* The __const__ attribute was added in gcc 2.95. */ -#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95) -# define _GL_ATTRIBUTE_CONST __attribute__ ((__const__)) +/* Attributes in bracket syntax [[...]] vs. attributes in __attribute__((...)) + syntax, in function declarations. There are two problems here. + (Last tested with gcc/g++ 14 and clang/clang++ 18.) + + 1) We want that the _GL_ATTRIBUTE_* can be cumulated on the same declaration + in any order. + =========================== foo.c = foo.cc =========================== + __attribute__ ((__deprecated__)) [[__nodiscard__]] int bar1 (int); + [[__nodiscard__]] __attribute__ ((__deprecated__)) int bar2 (int); + ====================================================================== + This gives a syntax error + - in C mode with gcc + , and + - in C++ mode with clang++ version < 16, and + - in C++ mode, inside extern "C" {}, still in newer clang++ versions + . + */ +/* Define if, in a function declaration, the attributes in bracket syntax + [[...]] must come before the attributes in __attribute__((...)) syntax. + If this is defined, it is best to avoid the bracket syntax, so that the + various _GL_ATTRIBUTE_* can be cumulated on the same declaration in any + order. */ +#ifdef __cplusplus +# if defined __clang__ +# define _GL_BRACKET_BEFORE_ATTRIBUTE 1 +# endif #else -# define _GL_ATTRIBUTE_CONST /* empty */ +# if defined __GNUC__ && !defined __clang__ +# define _GL_BRACKET_BEFORE_ATTRIBUTE 1 +# endif +#endif +/* + 2) We want that the _GL_ATTRIBUTE_* can be placed in a declaration + - without 'extern', in C as well as in C++, + - with 'extern', in C, + - with 'extern "C"', in C++ + in the same position. That is, we don't want to be forced to use a + macro which arranges for the attribute to come before 'extern' in + one case and after 'extern' in the other case, because such a macro + would make the source code of .h files pretty ugly. + =========================== foo.c = foo.cc =========================== + #ifdef __cplusplus + # define CC "C" + #else + # define CC + #endif + + #define ND [[__nodiscard__]] + #define WUR __attribute__((__warn_unused_result__)) + + #ifdef __cplusplus + extern "C" { + #endif + // gcc clang g++ clang++ + + ND int foo (int); + int ND foo (int); // warn error warn error + int foo ND (int); + int foo (int) ND; // warn error warn error + + WUR int foo (int); + int WUR foo (int); + int fo1 WUR (int); // error error error error + int foo (int) WUR; + + #ifdef __cplusplus + } + #endif + + // gcc clang g++ clang++ + + ND extern CC int foo (int); // error error + extern CC ND int foo (int); // error error + extern CC int ND foo (int); // warn error warn error + extern CC int foo ND (int); + extern CC int foo (int) ND; // warn error warn error + + WUR extern CC int foo (int); // warn + extern CC WUR int foo (int); + extern CC int WUR foo (int); + extern CC int foo WUR (int); // error error error error + extern CC int foo (int) WUR; + + ND EXTERN_C_FUNC int foo (int); // error error + EXTERN_C_FUNC ND int foo (int); + EXTERN_C_FUNC int ND foo (int); // warn error warn error + EXTERN_C_FUNC int foo ND (int); + EXTERN_C_FUNC int foo (int) ND; // warn error warn error + + WUR EXTERN_C_FUNC int foo (int); // warn + EXTERN_C_FUNC WUR int foo (int); + EXTERN_C_FUNC int WUR foo (int); + EXTERN_C_FUNC int fo2 WUR (int); // error error error error + EXTERN_C_FUNC int foo (int) WUR; + ====================================================================== + So, if we insist on using the 'extern' keyword ('extern CC' idiom): + * If _GL_ATTRIBUTE_* expands to bracket syntax [[...]] + in both C and C++, there is one available position: + - between the function name and the parameter list. + * If _GL_ATTRIBUTE_* expands to __attribute__((...)) syntax + in both C and C++, there are several available positions: + - before the return type, + - between return type and function name, + - at the end of the declaration. + * If _GL_ATTRIBUTE_* expands to bracket syntax [[...]] in C and to + __attribute__((...)) syntax in C++, there is no available position: + it would need to come before 'extern' in C but after 'extern "C"' + in C++. + * If _GL_ATTRIBUTE_* expands to __attribute__((...)) syntax in C and + to bracket syntax [[...]] in C++, there is one available position: + - before the return type. + Whereas, if we use the 'EXTERN_C_FUNC' idiom, which conditionally + omits the 'extern' keyword: + * If _GL_ATTRIBUTE_* expands to bracket syntax [[...]] + in both C and C++, there are two available positions: + - before the return type, + - between the function name and the parameter list. + * If _GL_ATTRIBUTE_* expands to __attribute__((...)) syntax + in both C and C++, there are several available positions: + - before the return type, + - between return type and function name, + - at the end of the declaration. + * If _GL_ATTRIBUTE_* expands to bracket syntax [[...]] in C and to + __attribute__((...)) syntax in C++, there is one available position: + - before the return type. + * If _GL_ATTRIBUTE_* expands to __attribute__((...)) syntax in C and + to bracket syntax [[...]] in C++, there is one available position: + - before the return type. + The best choice is therefore to use the 'EXTERN_C_FUNC' idiom and + put the attributes before the return type. This works regardless + to what the _GL_ATTRIBUTE_* macros expand. + */ + +/* Attributes in bracket syntax [[...]] vs. attributes in __attribute__((...)) + syntax, in static/inline function definitions. + + There are similar constraints as for function declarations. However, here, + we cannot omit the storage-class specifier. Therefore, the following rule + applies: + * The macros + _GL_ATTRIBUTE_CONST + _GL_ATTRIBUTE_DEPRECATED + _GL_ATTRIBUTE_MAYBE_UNUSED + _GL_ATTRIBUTE_NODISCARD + _GL_ATTRIBUTE_PURE + _GL_ATTRIBUTE_REPRODUCIBLE + _GL_ATTRIBUTE_UNSEQUENCED + which may expand to bracket syntax [[...]], must come first, before the + storage-class specifier. + * Other _GL_ATTRIBUTE_* macros, that expand to __attribute__((...)) syntax, + are better placed between the storage-class specifier and the return + type. + */ + +/* Attributes in bracket syntax [[...]] vs. attributes in __attribute__((...)) + syntax, in variable declarations. + + At which position can they be placed? + (Last tested with gcc/g++ 14 and clang/clang++ 18.) + + =========================== foo.c = foo.cc =========================== + #ifdef __cplusplus + # define CC "C" + #else + # define CC + #endif + + #define BD [[__deprecated__]] + #define AD __attribute__ ((__deprecated__)) + + // gcc clang g++ clang++ + + BD extern CC int var; // error error + extern CC BD int var; // error error + extern CC int BD var; // warn error warn error + extern CC int var BD; + + AD extern CC int var; // warn + extern CC AD int var; + extern CC int AD var; + extern CC int var AD; + + BD extern CC int z[]; // error error + extern CC BD int z[]; // error error + extern CC int BD z[]; // warn error warn error + extern CC int z1 BD []; + extern CC int z[] BD; // warn error error + + AD extern CC int z[]; // warn + extern CC AD int z[]; + extern CC int AD z[]; + extern CC int z2 AD []; // error error error error + extern CC int z[] AD; + ====================================================================== + + * For non-array variables, the only good position is after the variable name, + that is, at the end of the declaration. + * For array variables, you will need to distinguish C and C++: + - In C, before the 'extern' keyword. + - In C++, between the 'extern "C"' and the variable's type. + */ +]dnl There is no _GL_ATTRIBUTE_ALIGNED; use stdalign's alignas instead. +[ +/* _GL_ATTRIBUTE_ALLOC_SIZE ((N)) declares that the Nth argument of the function + is the size of the returned memory block. + _GL_ATTRIBUTE_ALLOC_SIZE ((M, N)) declares that the Mth argument multiplied + by the Nth argument of the function is the size of the returned memory block. + */ +/* Applies to: functions, pointer to functions, function types. */ +#ifndef _GL_ATTRIBUTE_ALLOC_SIZE +# if _GL_HAS_ATTRIBUTE (alloc_size) +# define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args)) +# else +# define _GL_ATTRIBUTE_ALLOC_SIZE(args) +# endif #endif -/* The __malloc__ attribute was added in gcc 3. */ -#if 3 <= __GNUC__ -# define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__)) +/* _GL_ATTRIBUTE_ALWAYS_INLINE tells that the compiler should always inline the + function and report an error if it cannot do so. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_ALWAYS_INLINE +# if _GL_HAS_ATTRIBUTE (always_inline) +# define _GL_ATTRIBUTE_ALWAYS_INLINE __attribute__ ((__always_inline__)) +# else +# define _GL_ATTRIBUTE_ALWAYS_INLINE +# endif +#endif + +/* _GL_ATTRIBUTE_ARTIFICIAL declares that the function is not important to show + in stack traces when debugging. The compiler should omit the function from + stack traces. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_ARTIFICIAL +# if _GL_HAS_ATTRIBUTE (artificial) +# define _GL_ATTRIBUTE_ARTIFICIAL __attribute__ ((__artificial__)) +# else +# define _GL_ATTRIBUTE_ARTIFICIAL +# endif +#endif + +/* _GL_ATTRIBUTE_COLD declares that the function is rarely executed. */ +/* Applies to: functions. */ +/* Avoid __attribute__ ((cold)) on MinGW; see thread starting at + . + Also, Oracle Studio 12.6 requires 'cold' not '__cold__'. */ +#ifndef _GL_ATTRIBUTE_COLD +# if _GL_HAS_ATTRIBUTE (cold) && !defined __MINGW32__ +# ifndef __SUNPRO_C +# define _GL_ATTRIBUTE_COLD __attribute__ ((__cold__)) +# else +# define _GL_ATTRIBUTE_COLD __attribute__ ((cold)) +# endif +# else +# define _GL_ATTRIBUTE_COLD +# endif +#endif + +/* _GL_ATTRIBUTE_CONST declares: + It is OK for a compiler to move calls to the function and to omit + calls to the function if another call has the same arguments or the + result is not used. + This attribute is safe for a function that neither depends on + nor affects state, and always returns exactly once - + e.g., does not raise an exception, call longjmp, or loop forever. + (This attribute is stricter than _GL_ATTRIBUTE_PURE because the + function cannot observe state. It is stricter than + _GL_ATTRIBUTE_UNSEQUENCED because the function must return exactly + once and cannot depend on state addressed by its arguments.) */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_CONST +# if _GL_HAS_ATTRIBUTE (const) +# define _GL_ATTRIBUTE_CONST __attribute__ ((__const__)) +# else +# define _GL_ATTRIBUTE_CONST _GL_ATTRIBUTE_UNSEQUENCED +# endif +#endif + +/* _GL_ATTRIBUTE_DEALLOC (F, I) declares that the function returns pointers + that can be freed by passing them as the Ith argument to the + function F. + _GL_ATTRIBUTE_DEALLOC_FREE declares that the function returns pointers that + can be freed via 'free'; it can be used only after declaring 'free'. */ +/* Applies to: functions. Cannot be used on inline functions. */ +#ifndef _GL_ATTRIBUTE_DEALLOC +# if _GL_GNUC_PREREQ (11, 0) +# define _GL_ATTRIBUTE_DEALLOC(f, i) __attribute__ ((__malloc__ (f, i))) +# else +# define _GL_ATTRIBUTE_DEALLOC(f, i) +# endif +#endif +/* If gnulib's or has already defined this macro, continue + to use this earlier definition, since may not have been included + yet. */ +#ifndef _GL_ATTRIBUTE_DEALLOC_FREE +# if defined __cplusplus && defined __GNUC__ && !defined __clang__ +/* Work around GCC bug */ +# define _GL_ATTRIBUTE_DEALLOC_FREE \ + _GL_ATTRIBUTE_DEALLOC ((void (*) (void *)) free, 1) +# else +# define _GL_ATTRIBUTE_DEALLOC_FREE \ + _GL_ATTRIBUTE_DEALLOC (free, 1) +# endif +#endif + +/* _GL_ATTRIBUTE_DEPRECATED: Declares that an entity is deprecated. + The compiler may warn if the entity is used. */ +/* Applies to: + - function, variable, + - struct, union, struct/union member, + - enumeration, enumeration item, + - typedef, + in C++ also: namespace, class, template specialization. */ +#ifndef _GL_ATTRIBUTE_DEPRECATED +# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE +# if _GL_HAVE___HAS_C_ATTRIBUTE +# if __has_c_attribute (__deprecated__) +# define _GL_ATTRIBUTE_DEPRECATED [[__deprecated__]] +# endif +# endif +# endif +# if !defined _GL_ATTRIBUTE_DEPRECATED && _GL_HAS_ATTRIBUTE (deprecated) +# define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__)) +# endif +# ifndef _GL_ATTRIBUTE_DEPRECATED +# define _GL_ATTRIBUTE_DEPRECATED +# endif +#endif + +/* _GL_ATTRIBUTE_ERROR(msg) requests an error if a function is called and + the function call is not optimized away. + _GL_ATTRIBUTE_WARNING(msg) requests a warning if a function is called and + the function call is not optimized away. */ +/* Applies to: functions. */ +#if !(defined _GL_ATTRIBUTE_ERROR && defined _GL_ATTRIBUTE_WARNING) +# if _GL_HAS_ATTRIBUTE (error) +# define _GL_ATTRIBUTE_ERROR(msg) __attribute__ ((__error__ (msg))) +# define _GL_ATTRIBUTE_WARNING(msg) __attribute__ ((__warning__ (msg))) +# elif _GL_HAS_ATTRIBUTE (diagnose_if) +# define _GL_ATTRIBUTE_ERROR(msg) __attribute__ ((__diagnose_if__ (1, msg, "error"))) +# define _GL_ATTRIBUTE_WARNING(msg) __attribute__ ((__diagnose_if__ (1, msg, "warning"))) +# else +# define _GL_ATTRIBUTE_ERROR(msg) +# define _GL_ATTRIBUTE_WARNING(msg) +# endif +#endif + +/* _GL_ATTRIBUTE_EXTERNALLY_VISIBLE declares that the entity should remain + visible to debuggers etc., even with '-fwhole-program'. */ +/* Applies to: functions, variables. */ +#ifndef _GL_ATTRIBUTE_EXTERNALLY_VISIBLE +# if _GL_HAS_ATTRIBUTE (externally_visible) +# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE __attribute__ ((externally_visible)) +# else +# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE +# endif +#endif + +/* _GL_ATTRIBUTE_FALLTHROUGH declares that it is not a programming mistake if + the control flow falls through to the immediately following 'case' or + 'default' label. The compiler should not warn in this case. */ +/* Applies to: Empty statement (;), inside a 'switch' statement. */ +/* Always expands to something. */ +#ifndef _GL_ATTRIBUTE_FALLTHROUGH +# if _GL_HAVE___HAS_C_ATTRIBUTE +# if __has_c_attribute (__fallthrough__) +# define _GL_ATTRIBUTE_FALLTHROUGH [[__fallthrough__]] +# endif +# endif +# if !defined _GL_ATTRIBUTE_FALLTHROUGH && _GL_HAS_ATTRIBUTE (fallthrough) +# define _GL_ATTRIBUTE_FALLTHROUGH __attribute__ ((__fallthrough__)) +# endif +# ifndef _GL_ATTRIBUTE_FALLTHROUGH +# define _GL_ATTRIBUTE_FALLTHROUGH ((void) 0) +# endif +#endif + +/* _GL_ATTRIBUTE_FORMAT ((ARCHETYPE, STRING-INDEX, FIRST-TO-CHECK)) + declares that the STRING-INDEXth function argument is a format string of + style ARCHETYPE, which is one of: + printf, gnu_printf + scanf, gnu_scanf, + strftime, gnu_strftime, + strfmon, + or the same thing prefixed and suffixed with '__'. + If FIRST-TO-CHECK is not 0, arguments starting at FIRST-TO_CHECK + are suitable for the format string. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_FORMAT +# if _GL_HAS_ATTRIBUTE (format) +# define _GL_ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec)) +# else +# define _GL_ATTRIBUTE_FORMAT(spec) +# endif +#endif + +/* _GL_ATTRIBUTE_LEAF declares that if the function is called from some other + compilation unit, it executes code from that unit only by return or by + exception handling. This declaration lets the compiler optimize that unit + more aggressively. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_LEAF +# if _GL_HAS_ATTRIBUTE (leaf) +# define _GL_ATTRIBUTE_LEAF __attribute__ ((__leaf__)) +# else +# define _GL_ATTRIBUTE_LEAF +# endif +#endif + +/* _GL_ATTRIBUTE_MALLOC declares that the function returns a pointer to freshly + allocated memory. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_MALLOC +# if _GL_HAS_ATTRIBUTE (malloc) +# define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__)) +# else +# define _GL_ATTRIBUTE_MALLOC +# endif +#endif + +/* _GL_ATTRIBUTE_MAY_ALIAS declares that pointers to the type may point to the + same storage as pointers to other types. Thus this declaration disables + strict aliasing optimization. */ +/* Applies to: types. */ +/* Oracle Studio 12.6 mishandles may_alias despite __has_attribute OK. */ +#ifndef _GL_ATTRIBUTE_MAY_ALIAS +# if _GL_HAS_ATTRIBUTE (may_alias) && !defined __SUNPRO_C +# define _GL_ATTRIBUTE_MAY_ALIAS __attribute__ ((__may_alias__)) +# else +# define _GL_ATTRIBUTE_MAY_ALIAS +# endif +#endif + +/* _GL_ATTRIBUTE_MAYBE_UNUSED declares that it is not a programming mistake if + the entity is not used. The compiler should not warn if the entity is not + used. */ +/* Applies to: + - function, variable, + - struct, union, struct/union member, + - enumeration, enumeration item, + - typedef, + in C++ also: class. */ +/* In C++ and C23, this is spelled [[__maybe_unused__]]. + GCC's syntax is __attribute__ ((__unused__)). + clang supports both syntaxes. Except that with clang ≥ 6, < 10, in C++ mode, + __has_c_attribute (__maybe_unused__) yields true but the use of + [[__maybe_unused__]] nevertheless produces a warning. */ +#ifndef _GL_ATTRIBUTE_MAYBE_UNUSED +# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE +# if defined __clang__ && defined __cplusplus +# if !defined __apple_build_version__ && __clang_major__ >= 10 +# define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]] +# endif +# elif _GL_HAVE___HAS_C_ATTRIBUTE +# if __has_c_attribute (__maybe_unused__) +# define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]] +# endif +# endif +# endif +# ifndef _GL_ATTRIBUTE_MAYBE_UNUSED +# define _GL_ATTRIBUTE_MAYBE_UNUSED _GL_ATTRIBUTE_UNUSED +# endif +#endif +/* Alternative spelling of this macro, for convenience and for + compatibility with glibc/include/libc-symbols.h. */ +#define _GL_UNUSED _GL_ATTRIBUTE_MAYBE_UNUSED +/* Earlier spellings of this macro. */ +#define _UNUSED_PARAMETER_ _GL_ATTRIBUTE_MAYBE_UNUSED + +/* _GL_ATTRIBUTE_NODISCARD declares that the caller of the function should not + discard the return value. The compiler may warn if the caller does not use + the return value, unless the caller uses something like ignore_value. */ +/* Applies to: function, enumeration, class. */ +#ifndef _GL_ATTRIBUTE_NODISCARD +# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE +# if defined __clang__ && defined __cplusplus + /* With clang up to 15.0.6 (at least), in C++ mode, [[__nodiscard__]] produces + a warning. + The 1000 below means a yet unknown threshold. When clang++ version X + starts supporting [[__nodiscard__]] without warning about it, you can + replace the 1000 with X. */ +# if __clang_major__ >= 1000 +# define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]] +# endif +# elif _GL_HAVE___HAS_C_ATTRIBUTE +# if __has_c_attribute (__nodiscard__) +# define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]] +# endif +# endif +# endif +# if !defined _GL_ATTRIBUTE_NODISCARD && _GL_HAS_ATTRIBUTE (warn_unused_result) +# define _GL_ATTRIBUTE_NODISCARD __attribute__ ((__warn_unused_result__)) +# endif +# ifndef _GL_ATTRIBUTE_NODISCARD +# define _GL_ATTRIBUTE_NODISCARD +# endif +#endif + +/* _GL_ATTRIBUTE_NOINLINE tells that the compiler should not inline the + function. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_NOINLINE +# if _GL_HAS_ATTRIBUTE (noinline) +# define _GL_ATTRIBUTE_NOINLINE __attribute__ ((__noinline__)) +# else +# define _GL_ATTRIBUTE_NOINLINE +# endif +#endif + +/* _GL_ATTRIBUTE_NONNULL ((N1, N2,...)) declares that the arguments N1, N2,... + must not be NULL. + _GL_ATTRIBUTE_NONNULL () declares that all pointer arguments must not be + null. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_NONNULL +# if _GL_HAS_ATTRIBUTE (nonnull) +# define _GL_ATTRIBUTE_NONNULL(args) __attribute__ ((__nonnull__ args)) +# else +# define _GL_ATTRIBUTE_NONNULL(args) +# endif +#endif + +/* _GL_ATTRIBUTE_NONNULL_IF_NONZERO (NP, NI) declares that the argument NP + (a pointer) must not be NULL if the argument NI (an integer) is != 0. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_NONNULL_IF_NONZERO +# if _GL_HAS_ATTRIBUTE (nonnull_if_nonzero) +# define _GL_ATTRIBUTE_NONNULL_IF_NONZERO(np, ni) __attribute__ ((__nonnull_if_nonzero__ (np, ni))) +# else +# define _GL_ATTRIBUTE_NONNULL_IF_NONZERO(np, ni) +# endif +#endif + +/* _GL_ATTRIBUTE_NONSTRING declares that the contents of a character array is + not meant to be NUL-terminated. */ +/* Applies to: struct/union members and variables that are arrays of element + type '[[un]signed] char'. */ +#ifndef _GL_ATTRIBUTE_NONSTRING +# if _GL_HAS_ATTRIBUTE (nonstring) +# define _GL_ATTRIBUTE_NONSTRING __attribute__ ((__nonstring__)) +# else +# define _GL_ATTRIBUTE_NONSTRING +# endif +#endif + +/* There is no _GL_ATTRIBUTE_NORETURN; use _Noreturn instead. */ + +/* _GL_ATTRIBUTE_NOTHROW declares that the function does not throw exceptions. + */ +/* Applies to: functions. */ +/* After a function's parameter list, this attribute must come first, before + other attributes. */ +#ifndef _GL_ATTRIBUTE_NOTHROW +# if defined __cplusplus +# if _GL_GNUC_PREREQ (2, 8) || __clang_major__ >= 4 +# if __cplusplus >= 201103L +# define _GL_ATTRIBUTE_NOTHROW noexcept (true) +# else +# define _GL_ATTRIBUTE_NOTHROW throw () +# endif +# else +# define _GL_ATTRIBUTE_NOTHROW +# endif +# else +# if _GL_HAS_ATTRIBUTE (nothrow) +# define _GL_ATTRIBUTE_NOTHROW __attribute__ ((__nothrow__)) +# else +# define _GL_ATTRIBUTE_NOTHROW +# endif +# endif +#endif + +/* _GL_ATTRIBUTE_PACKED declares: + For struct members: The member has the smallest possible alignment. + For struct, union, class: All members have the smallest possible alignment, + minimizing the memory required. */ +/* Applies to: struct members, struct, union, + in C++ also: class. */ +#ifndef _GL_ATTRIBUTE_PACKED +/* Oracle Studio 12.6 miscompiles code with __attribute__ ((__packed__)) despite + __has_attribute OK. */ +# if _GL_HAS_ATTRIBUTE (packed) && !defined __SUNPRO_C +# define _GL_ATTRIBUTE_PACKED __attribute__ ((__packed__)) +# else +# define _GL_ATTRIBUTE_PACKED +# endif +#endif + +/* _GL_ATTRIBUTE_PURE declares: + It is OK for a compiler to move calls to the function and to omit + calls to the function if another call has the same arguments or the + result is not used, and if observable state is the same. + This attribute is safe for a function that does not affect observable state + and always returns exactly once. + (This attribute is looser than _GL_ATTRIBUTE_CONST because the function + can depend on observable state. It is stricter than + _GL_ATTRIBUTE_REPRODUCIBLE because the function must return exactly + once and cannot affect state addressed by its arguments.) */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_PURE +# if _GL_HAS_ATTRIBUTE (pure) +# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__)) +# else +# define _GL_ATTRIBUTE_PURE _GL_ATTRIBUTE_REPRODUCIBLE +# endif +#endif + +/* _GL_ATTRIBUTE_REPRODUCIBLE declares: + It is OK for a compiler to move calls to the function and to omit duplicate + calls to the function with the same arguments, so long as the state + addressed by its arguments is the same and is updated in time for + the rest of the program. + This attribute is safe for a function that is effectless and idempotent; see + ISO C 23 § 6.7.12.7 for a definition of these terms. + (This attribute is looser than _GL_ATTRIBUTE_UNSEQUENCED because + the function need not be stateless and idempotent. It is looser + than _GL_ATTRIBUTE_PURE because the function need not return + exactly once and can affect state addressed by its arguments.) + See also and + . + ATTENTION! Efforts are underway to change the meaning of this attribute. + See . */ +/* Applies to: functions, pointer to functions, function types. */ +#ifndef _GL_ATTRIBUTE_REPRODUCIBLE +/* This may be revisited when gcc and clang support [[reproducible]] or possibly + __attribute__ ((__reproducible__)). */ +# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE +# if _GL_HAS_ATTRIBUTE (reproducible) +# define _GL_ATTRIBUTE_REPRODUCIBLE [[reproducible]] +# endif +# endif +# ifndef _GL_ATTRIBUTE_REPRODUCIBLE +# define _GL_ATTRIBUTE_REPRODUCIBLE +# endif +#endif + +/* _GL_ATTRIBUTE_RETURNS_NONNULL declares that the function's return value is + a non-NULL pointer. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_RETURNS_NONNULL +# if _GL_HAS_ATTRIBUTE (returns_nonnull) +# define _GL_ATTRIBUTE_RETURNS_NONNULL __attribute__ ((__returns_nonnull__)) +# else +# define _GL_ATTRIBUTE_RETURNS_NONNULL +# endif +#endif + +/* _GL_ATTRIBUTE_SENTINEL(pos) declares that the variadic function expects a + trailing NULL argument. + _GL_ATTRIBUTE_SENTINEL () - The last argument is NULL (requires C99). + _GL_ATTRIBUTE_SENTINEL ((N)) - The (N+1)st argument from the end is NULL. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_SENTINEL +# if _GL_HAS_ATTRIBUTE (sentinel) +# define _GL_ATTRIBUTE_SENTINEL(pos) __attribute__ ((__sentinel__ pos)) +# else +# define _GL_ATTRIBUTE_SENTINEL(pos) +# endif +#endif + +/* _GL_ATTRIBUTE_UNSEQUENCED declares: + It is OK for a compiler to move calls to the function and to omit duplicate + calls to the function with the same arguments, so long as the state + addressed by its arguments is the same. + This attribute is safe for a function that is effectless, idempotent, + stateless, and independent; see ISO C 23 § 6.7.12.7 for a definition of + these terms. + (This attribute is stricter than _GL_ATTRIBUTE_REPRODUCIBLE because + the function must be stateless and independent. It is looser than + _GL_ATTRIBUTE_CONST because the function need not return exactly + once and can depend on state addressed by its arguments.) + See also and + . + ATTENTION! Efforts are underway to change the meaning of this attribute. + See . */ +/* Applies to: functions, pointer to functions, function types. */ +#ifndef _GL_ATTRIBUTE_UNSEQUENCED +/* This may be revisited when gcc and clang support [[unsequenced]] or possibly + __attribute__ ((__unsequenced__)). */ +# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE +# if _GL_HAS_ATTRIBUTE (unsequenced) +# define _GL_ATTRIBUTE_UNSEQUENCED [[unsequenced]] +# endif +# endif +# ifndef _GL_ATTRIBUTE_UNSEQUENCED +# define _GL_ATTRIBUTE_UNSEQUENCED +# endif +#endif + +/* A helper macro. Don't use it directly. */ +#ifndef _GL_ATTRIBUTE_UNUSED +# if _GL_HAS_ATTRIBUTE (unused) +# define _GL_ATTRIBUTE_UNUSED __attribute__ ((__unused__)) +# else +# define _GL_ATTRIBUTE_UNUSED +# endif +#endif + +]dnl There is no _GL_ATTRIBUTE_VISIBILITY; see m4/visibility.m4 instead. +[ +/* _GL_UNUSED_LABEL; declares that it is not a programming mistake if the + immediately preceding label is not used. The compiler should not warn + if the label is not used. */ +/* Applies to: label (both in C and C++). */ +/* Note that g++ < 4.5 does not support the '__attribute__ ((__unused__)) ;' + syntax. But clang does. */ +#ifndef _GL_UNUSED_LABEL +# if !(defined __cplusplus && !_GL_GNUC_PREREQ (4, 5)) || defined __clang__ +# define _GL_UNUSED_LABEL _GL_ATTRIBUTE_UNUSED +# else +# define _GL_UNUSED_LABEL +# endif +#endif + +/* The following attributes enable detection of multithread-safety problems + and resource leaks at compile-time, by clang ≥ 15, when the warning option + -Wthread-safety is enabled. For usage, see + . */ +#ifndef _GL_ATTRIBUTE_CAPABILITY_TYPE +# if __clang_major__ >= 15 +# define _GL_ATTRIBUTE_CAPABILITY_TYPE(concept) \ + __attribute__ ((__capability__ (concept))) +# else +# define _GL_ATTRIBUTE_CAPABILITY_TYPE(concept) +# endif +#endif +#ifndef _GL_ATTRIBUTE_ACQUIRE_CAPABILITY +# if __clang_major__ >= 15 +# define _GL_ATTRIBUTE_ACQUIRE_CAPABILITY(resource) \ + __attribute__ ((__acquire_capability__ (resource))) +# else +# define _GL_ATTRIBUTE_ACQUIRE_CAPABILITY(resource) +# endif +#endif +#ifndef _GL_ATTRIBUTE_RELEASE_CAPABILITY +# if __clang_major__ >= 15 +# define _GL_ATTRIBUTE_RELEASE_CAPABILITY(resource) \ + __attribute__ ((__release_capability__ (resource))) +# else +# define _GL_ATTRIBUTE_RELEASE_CAPABILITY(resource) +# endif +#endif +]) + AH_VERBATIM([c_linkage], +[/* In C++, there is the concept of "language linkage", that encompasses + name mangling and function calling conventions. + The following macros start and end a block of "C" linkage. */ +#ifdef __cplusplus +# define _GL_BEGIN_C_LINKAGE extern "C" { +# define _GL_END_C_LINKAGE } #else -# define _GL_ATTRIBUTE_MALLOC /* empty */ +# define _GL_BEGIN_C_LINKAGE +# define _GL_END_C_LINKAGE #endif ]) AH_VERBATIM([async_safe], @@ -94,7 +924,7 @@ AC_DEFUN([gl_COMMON_BODY], [ invoked from such signal handlers. Such functions have some restrictions: * All functions that it calls should be marked _GL_ASYNC_SAFE as well, or should be listed as async-signal-safe in POSIX - + section 2.4.3. Note that malloc(), sprintf(), and fwrite(), in particular, are NOT async-signal-safe. * All memory locations (variables and struct fields) that these functions @@ -115,6 +945,49 @@ AC_DEFUN([gl_COMMON_BODY], [ errno. */ #define _GL_ASYNC_SAFE ]) + AH_VERBATIM([micro_optimizations], +[/* _GL_CMP (n1, n2) performs a three-valued comparison on n1 vs. n2, where + n1 and n2 are expressions without side effects, that evaluate to real + numbers (excluding NaN). + It returns + 1 if n1 > n2 + 0 if n1 == n2 + -1 if n1 < n2 + The naïve code (n1 > n2 ? 1 : n1 < n2 ? -1 : 0) produces a conditional + jump with nearly all GCC versions up to GCC 10. + This variant (n1 < n2 ? -1 : n1 > n2) produces a conditional with many + GCC versions up to GCC 9. + The better code (n1 > n2) - (n1 < n2) from Hacker's Delight § 2-9 + avoids conditional jumps in all GCC versions >= 3.4. */ +#define _GL_CMP(n1, n2) (((n1) > (n2)) - ((n1) < (n2))) +]) + dnl Hint which direction to take regarding cross-compilation guesses: + dnl When a user installs a program on a platform they are not intimately + dnl familiar with, --enable-cross-guesses=conservative is the appropriate + dnl choice. It implements the "If we don't know, assume the worst" principle. + dnl However, when an operating system developer (on a platform which is not + dnl yet known to gnulib) builds packages for their platform, they want to + dnl expose, not hide, possible platform bugs; in this case, + dnl --enable-cross-guesses=risky is the appropriate choice. + dnl Sets the variables + dnl gl_cross_guess_normal (to be used when 'yes' is good and 'no' is bad), + dnl gl_cross_guess_inverted (to be used when 'no' is good and 'yes' is bad). + AC_ARG_ENABLE([cross-guesses], + [AS_HELP_STRING([[--enable-cross-guesses={conservative|risky}]], + [specify policy for cross-compilation guesses])], + [if test "x$enableval" != xconservative && test "x$enableval" != xrisky; then + AC_MSG_WARN([invalid argument supplied to --enable-cross-guesses]) + enableval=conservative + fi + gl_cross_guesses="$enableval"], + [gl_cross_guesses=conservative]) + if test $gl_cross_guesses = risky; then + gl_cross_guess_normal="guessing yes" + gl_cross_guess_inverted="guessing no" + else + gl_cross_guess_normal="guessing no" + gl_cross_guess_inverted="guessing yes" + fi dnl Preparation for running test programs: dnl Tell glibc to write diagnostics from -D_FORTIFY_SOURCE=2 to stderr, not dnl to /dev/tty, so they can be redirected to log files. Such diagnostics @@ -123,6 +996,16 @@ AC_DEFUN([gl_COMMON_BODY], [ export LIBC_FATAL_STDERR_ ]) +# gl_MODULE_INDICATOR_INIT_VARIABLE([variablename]) +# gl_MODULE_INDICATOR_INIT_VARIABLE([variablename], [initialvalue]) +# initializes the shell variable that indicates the presence of the given module +# as a C preprocessor expression. +AC_DEFUN([gl_MODULE_INDICATOR_INIT_VARIABLE], +[ + GL_MODULE_INDICATOR_PREFIX[]_[$1]=m4_if([$2], , [0], [$2]) + AC_SUBST(GL_MODULE_INDICATOR_PREFIX[]_[$1]) +]) + # gl_MODULE_INDICATOR_CONDITION # expands to a C preprocessor expression that evaluates to 1 or 0, depending # whether a gnulib module that has been requested shall be considered present @@ -135,9 +1018,9 @@ m4_define([gl_MODULE_INDICATOR_CONDITION], [1]) AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE], [ gl_MODULE_INDICATOR_SET_VARIABLE_AUX( - [GNULIB_[]m4_translit([[$1]], - [abcdefghijklmnopqrstuvwxyz./-], - [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])], + [GL_MODULE_INDICATOR_PREFIX[]_GNULIB_[]m4_translit([[$1]], + [abcdefghijklmnopqrstuvwxyz./-], + [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])], [gl_MODULE_INDICATOR_CONDITION]) ]) @@ -249,34 +1132,20 @@ AC_DEFUN([gl_FEATURES_H], AC_SUBST([HAVE_FEATURES_H]) ]) -# AS_VAR_IF(VAR, VALUE, [IF-MATCH], [IF-NOT-MATCH]) -# ---------------------------------------------------- -# Backport of autoconf-2.63b's macro. -# Remove this macro when we can assume autoconf >= 2.64. -m4_ifndef([AS_VAR_IF], -[m4_define([AS_VAR_IF], -[AS_IF([test x"AS_VAR_GET([$1])" = x""$2], [$3], [$4])])]) - # gl_PROG_CC_C99 # Modifies the value of the shell variable CC in an attempt to make $CC # understand ISO C99 source code. -# This is like AC_PROG_CC_C99, except that -# - AC_PROG_CC_C99 does not mix well with AC_PROG_CC_STDC -# , -# but many more packages use AC_PROG_CC_STDC than AC_PROG_CC_C99 -# . -# Remaining problems: -# - When AC_PROG_CC_STDC is invoked twice, it adds the C99 enabling options -# to CC twice -# . -# - AC_PROG_CC_STDC is likely to change now that C11 is an ISO standard. AC_DEFUN([gl_PROG_CC_C99], [ - dnl Change that version number to the minimum Autoconf version that supports - dnl mixing AC_PROG_CC_C99 calls with AC_PROG_CC_STDC calls. - m4_version_prereq([9.0], - [AC_REQUIRE([AC_PROG_CC_C99])], - [AC_REQUIRE([AC_PROG_CC_STDC])]) + dnl Just use AC_PROG_CC_C99. + dnl When AC_PROG_CC_C99 and AC_PROG_CC_STDC are used together, the substituted + dnl value of CC will contain the C99 enabling options twice. But this is only + dnl a cosmetic problem. + dnl With Autoconf >= 2.70, use AC_PROG_CC since it implies AC_PROG_CC_C99; + dnl this avoids a "warning: The macro `AC_PROG_CC_C99' is obsolete." + m4_version_prereq([2.70], + [AC_REQUIRE([AC_PROG_CC])], + [AC_REQUIRE([AC_PROG_CC_C99])]) ]) # gl_PROG_AR_RANLIB @@ -350,16 +1219,16 @@ Amsterdam ]) # AC_C_RESTRICT -# This definition is copied from post-2.69 Autoconf and overrides the -# AC_C_RESTRICT macro from autoconf 2.60..2.69. It can be removed -# once autoconf >= 2.70 can be assumed. It's painful to check version -# numbers, and in practice this macro is more up-to-date than Autoconf -# is, so override Autoconf unconditionally. +# This definition is copied from post-2.70 Autoconf and overrides the +# AC_C_RESTRICT macro from autoconf 2.60..2.70. +m4_version_prereq([2.70.1], [], [ AC_DEFUN([AC_C_RESTRICT], [AC_CACHE_CHECK([for C/C++ restrict keyword], [ac_cv_c_restrict], [ac_cv_c_restrict=no - # The order here caters to the fact that C++ does not require restrict. - for ac_kw in __restrict __restrict__ _Restrict restrict; do + # Put '__restrict__' first, to avoid problems with glibc and non-GCC; see: + # https://lists.gnu.org/archive/html/bug-autoconf/2016-02/msg00006.html + # Put 'restrict' last, because C++ lacks it. + for ac_kw in __restrict__ __restrict _Restrict restrict; do AC_COMPILE_IFELSE( [AC_LANG_PROGRAM( [[typedef int *int_ptr; @@ -379,14 +1248,15 @@ AC_DEFUN([AC_C_RESTRICT], AH_VERBATIM([restrict], [/* Define to the equivalent of the C99 'restrict' keyword, or to nothing if this is not supported. Do not define if restrict is - supported directly. */ + supported only directly. */ #undef restrict -/* Work around a bug in Sun C++: it does not support _Restrict or - __restrict__, even though the corresponding Sun C compiler ends up with - "#define restrict _Restrict" or "#define restrict __restrict__" in the - previous line. Perhaps some future version of Sun C++ will work with - restrict; if so, hopefully it defines __RESTRICT like Sun C does. */ -#if defined __SUNPRO_CC && !defined __RESTRICT +/* Work around a bug in older versions of Sun C++, which did not + #define __restrict__ or support _Restrict or __restrict__ + even though the corresponding Sun C compiler ended up with + "#define restrict _Restrict" or "#define restrict __restrict__" + in the previous line. This workaround can be removed once + we assume Oracle Developer Studio 12.5 (2016) or later. */ +#if defined __SUNPRO_CC && !defined __RESTRICT && !defined __restrict__ # define _Restrict # define __restrict__ #endif]) @@ -396,6 +1266,7 @@ AC_DEFUN([AC_C_RESTRICT], *) AC_DEFINE_UNQUOTED([restrict], [$ac_cv_c_restrict]) ;; esac ])# AC_C_RESTRICT +]) # gl_BIGENDIAN # is like AC_C_BIGENDIAN, except that it can be AC_REQUIREd. @@ -406,6 +1277,22 @@ AC_DEFUN([gl_BIGENDIAN], AC_C_BIGENDIAN ]) +# A temporary file descriptor. +# Must be less than 10, because dash 0.5.8 does not support redirections +# with multi-digit file descriptors. +m4_define([GL_TMP_FD], 9) + +# gl_SILENT(command) +# executes command, but without the normal configure output. +# This is useful when you want to invoke AC_CACHE_CHECK (or AC_CHECK_FUNC etc.) +# inside another AC_CACHE_CHECK. +AC_DEFUN([gl_SILENT], +[ + exec GL_TMP_FD>&AS_MESSAGE_FD AS_MESSAGE_FD>/dev/null + $1 + exec AS_MESSAGE_FD>&GL_TMP_FD GL_TMP_FD>&- +]) + # gl_CACHE_VAL_SILENT(cache-id, command-to-set-it) # is like AC_CACHE_VAL(cache-id, command-to-set-it), except that it does not # output a spurious "(cached)" mark in the midst of other configure output. @@ -413,12 +1300,497 @@ AC_DEFUN([gl_BIGENDIAN], # by an AC_MSG_CHECKING/AC_MSG_RESULT pair. AC_DEFUN([gl_CACHE_VAL_SILENT], [ - saved_as_echo_n="$as_echo_n" - as_echo_n=':' - AC_CACHE_VAL([$1], [$2]) - as_echo_n="$saved_as_echo_n" + gl_SILENT([ + AC_CACHE_VAL([$1], [$2]) + ]) ]) -# AS_VAR_COPY was added in autoconf 2.63b -m4_define_default([AS_VAR_COPY], -[AS_LITERAL_IF([$1[]$2], [$1=$$2], [eval $1=\$$2])]) +# gl_CONDITIONAL(conditional, condition) +# is like AM_CONDITIONAL(conditional, condition), except that it does not +# produce an error +# configure: error: conditional "..." was never defined. +# Usually this means the macro was only invoked conditionally. +# when only invoked conditionally. Instead, in that case, both the _TRUE +# and the _FALSE case are disabled. +AC_DEFUN([gl_CONDITIONAL], +[ + pushdef([AC_CONFIG_COMMANDS_PRE], [:])dnl + AM_CONDITIONAL([$1], [$2]) + popdef([AC_CONFIG_COMMANDS_PRE])dnl + if test -z "${[$1]_TRUE}" && test -z "${[$1]_FALSE}"; then + [$1]_TRUE='#' + [$1]_FALSE='#' + fi +]) + +# gl_CC_ALLOW_WARNINGS +# sets and substitutes a variable GL_CFLAG_ALLOW_WARNINGS, to a $(CC) option +# that reverts a preceding '-Werror' option, if available. +# This is expected to be '-Wno-error' on gcc, clang (except clang/MSVC), xlclang +# and empty otherwise. +AC_DEFUN([gl_CC_ALLOW_WARNINGS], +[ + AC_REQUIRE([AC_PROG_CC]) + AC_CACHE_CHECK([for C compiler option to allow warnings], + [gl_cv_cc_wallow], + [rm -fr conftest* + echo 'int dummy;' > conftest.c + AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -c conftest.c 2>conftest1.err]) >/dev/null + AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -Wno-error -c conftest.c 2>conftest2.err]) >/dev/null + dnl Test the number of error output lines, because AIX xlc accepts the + dnl option '-Wno-error', just to produce a warning + dnl "Option -Wno-error was incorrectly specified. The option will be ignored." + dnl afterwards. + if test $? = 0 && test `wc -l < conftest1.err` = `wc -l < conftest2.err`; then + gl_cv_cc_wallow='-Wno-error' + else + gl_cv_cc_wallow=none + fi + rm -fr conftest* + ]) + case "$gl_cv_cc_wallow" in + none) GL_CFLAG_ALLOW_WARNINGS='' ;; + *) GL_CFLAG_ALLOW_WARNINGS="$gl_cv_cc_wallow" ;; + esac + AC_SUBST([GL_CFLAG_ALLOW_WARNINGS]) +]) + +# gl_CXX_ALLOW_WARNINGS +# sets and substitutes a variable GL_CXXFLAG_ALLOW_WARNINGS, to a $(CC) option +# that reverts a preceding '-Werror' option, if available. +AC_DEFUN([gl_CXX_ALLOW_WARNINGS], +[ + dnl Requires AC_PROG_CXX or gl_PROG_ANSI_CXX. + if test -n "$CXX" && test "$CXX" != no; then + AC_CACHE_CHECK([for C++ compiler option to allow warnings], + [gl_cv_cxx_wallow], + [rm -fr conftest* + echo 'int dummy;' > conftest.cc + AC_TRY_COMMAND([${CXX-c++} $CXXFLAGS $CPPFLAGS -c conftest.cc 2>conftest1.err]) >/dev/null + AC_TRY_COMMAND([${CXX-c++} $CXXFLAGS $CPPFLAGS -Wno-error -c conftest.cc 2>conftest2.err]) >/dev/null + dnl Test the number of error output lines, because AIX xlC accepts the + dnl option '-Wno-error', just to produce a warning + dnl "Option -Wno-error was incorrectly specified. The option will be ignored." + dnl afterwards. + if test $? = 0 && test `wc -l < conftest1.err` = `wc -l < conftest2.err`; then + gl_cv_cxx_wallow='-Wno-error' + else + gl_cv_cxx_wallow=none + fi + rm -fr conftest* + ]) + case "$gl_cv_cxx_wallow" in + none) GL_CXXFLAG_ALLOW_WARNINGS='' ;; + *) GL_CXXFLAG_ALLOW_WARNINGS="$gl_cv_cxx_wallow" ;; + esac + else + GL_CXXFLAG_ALLOW_WARNINGS='' + fi + AC_SUBST([GL_CXXFLAG_ALLOW_WARNINGS]) +]) + +# gl_CC_GNULIB_WARNINGS +# sets and substitutes a variable GL_CFLAG_GNULIB_WARNINGS, to a $(CC) option +# set that enables or disables warnings as suitable for the Gnulib coding style. +AC_DEFUN([gl_CC_GNULIB_WARNINGS], +[ + AC_REQUIRE([gl_CC_ALLOW_WARNINGS]) + dnl Assume that the compiler supports -Wno-* options only if it also supports + dnl -Wno-error. + GL_CFLAG_GNULIB_WARNINGS='' + if test -n "$GL_CFLAG_ALLOW_WARNINGS"; then + dnl Enable these warning options: + dnl + dnl GCC clang + dnl -Wno-cast-qual >= 3 >= 3.9 + dnl -Wno-conversion >= 3 >= 3.9 + dnl -Wno-float-conversion >= 4.9 >= 3.9 + dnl -Wno-float-equal >= 3 >= 3.9 + dnl -Wimplicit-fallthrough >= 7 >= 3.9 + dnl -Wno-pedantic >= 4.8 >= 3.9 + dnl -Wno-sign-compare >= 3 >= 3.9 + dnl -Wno-sign-conversion >= 4.3 >= 3.9 + dnl -Wno-tautological-out-of-range-compare - >= 3.9 + dnl -Wno-type-limits >= 4.3 >= 3.9 + dnl -Wno-undef >= 3 >= 3.9 + dnl -Wno-unsuffixed-float-constants >= 4.5 + dnl -Wno-unused-const-variable >= 4.4 >= 3.9 + dnl -Wno-unused-function >= 3 >= 3.9 + dnl -Wno-unused-parameter >= 3 >= 3.9 + dnl + cat > conftest.c <<\EOF + #if (__GNUC__ >= 3 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-cast-qual + -Wno-conversion + -Wno-float-equal + -Wno-sign-compare + -Wno-undef + -Wno-unused-function + -Wno-unused-parameter + #endif + #if (__GNUC__ + (__GNUC_MINOR__ >= 9) > 4 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-float-conversion + #endif + #if (__GNUC__ >= 7 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wimplicit-fallthrough + #endif + #if (__GNUC__ + (__GNUC_MINOR__ >= 8) > 4 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-pedantic + #endif + #if 3 < __clang_major__ + (9 <= __clang_minor__) + -Wno-tautological-constant-out-of-range-compare + #endif + #if (__GNUC__ + (__GNUC_MINOR__ >= 3) > 4 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-sign-conversion + -Wno-type-limits + #endif + #if (__GNUC__ + (__GNUC_MINOR__ >= 4) > 4 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-unused-const-variable + #endif + #if (__GNUC__ + (__GNUC_MINOR__ >= 5) > 4 && !defined __clang__) + -Wno-unsuffixed-float-constants + #endif +EOF + gl_command="$CC $CFLAGS $CPPFLAGS -E conftest.c > conftest.out" + if AC_TRY_EVAL([gl_command]); then + gl_options=`grep -v '#' conftest.out` + for word in $gl_options; do + GL_CFLAG_GNULIB_WARNINGS="$GL_CFLAG_GNULIB_WARNINGS $word" + done + fi + rm -f conftest.c conftest.out + fi + AC_SUBST([GL_CFLAG_GNULIB_WARNINGS]) +]) + +dnl gl_CONDITIONAL_HEADER([foo.h]) +dnl takes a shell variable GL_GENERATE_FOO_H (with value true or false) as input +dnl and produces +dnl - an AC_SUBSTed variable FOO_H that is either a file name or empty, based +dnl on whether GL_GENERATE_FOO_H is true or false, +dnl - an Automake conditional GL_GENERATE_FOO_H that evaluates to the value of +dnl the shell variable GL_GENERATE_FOO_H. +AC_DEFUN([gl_CONDITIONAL_HEADER], +[ + m4_pushdef([gl_header_name], AS_TR_SH(m4_toupper($1))) + m4_pushdef([gl_generate_var], [GL_GENERATE_]AS_TR_SH(m4_toupper($1))) + m4_pushdef([gl_generate_cond], [GL_GENERATE_]AS_TR_SH(m4_toupper($1))) + case "$gl_generate_var" in + false) gl_header_name='' ;; + true) + dnl It is OK to use a .h file in lib/ from within tests/, but not vice + dnl versa. + if test -z "$gl_header_name"; then + gl_header_name="${gl_source_base_prefix}$1" + fi + ;; + *) echo "*** gl_generate_var is not set correctly" 1>&2; exit 1 ;; + esac + AC_SUBST(gl_header_name) + gl_CONDITIONAL(gl_generate_cond, [$gl_generate_var]) + m4_popdef([gl_generate_cond]) + m4_popdef([gl_generate_var]) + m4_popdef([gl_header_name]) +]) + +dnl Preparations for gl_CHECK_FUNCS_MACOS. +AC_DEFUN([gl_PREPARE_CHECK_FUNCS_MACOS], +[ + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_REQUIRE([gl_COMPILER_CLANG]) + AC_CACHE_CHECK([for compiler option needed when checking for future declarations], + [gl_cv_compiler_check_future_option], + [case "$host_os" in + dnl This is only needed on macOS. + darwin*) + if test $gl_cv_compiler_clang = yes; then + dnl Test whether the compiler supports the option + dnl '-Werror=unguarded-availability-new'. + saved_ac_compile="$ac_compile" + ac_compile="$ac_compile -Werror=unguarded-availability-new" + AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]],[[]])], + [gl_cv_compiler_check_future_option='-Werror=unguarded-availability-new'], + [gl_cv_compiler_check_future_option=none]) + ac_compile="$saved_ac_compile" + else + gl_cv_compiler_check_future_option=none + fi + ;; + *) gl_cv_compiler_check_future_option=none ;; + esac + ]) +]) + +dnl Pieces of the expansion of +dnl gl_CHECK_FUNCS_ANDROID +dnl gl_CHECK_FUNCS_MACOS +dnl gl_CHECK_FUNCS_ANDROID_MACOS + +AC_DEFUN([gl_CHECK_FUNCS_DEFAULT_CASE], +[ + *) + AC_CHECK_FUNC([$1]) + [gl_cv_onwards_func_][$1]=$[ac_cv_func_][$1] + ;; +]) + +AC_DEFUN([gl_CHECK_FUNCS_CASE_FOR_ANDROID], +[ + linux*-android*) + AC_CHECK_DECL([$1], , , [$2]) + if test $[ac_cv_have_decl_][$1] = yes; then + AC_CHECK_FUNC([[$1]]) + if test $[ac_cv_func_][$1] = yes; then + [gl_cv_onwards_func_][$1]=yes + else + dnl The function is declared but does not exist. This should not + dnl happen normally. But anyway, we know that a future version + dnl of Android will have the function. + [gl_cv_onwards_func_][$1]='future OS version' + fi + else + [gl_cv_onwards_func_][$1]='future OS version' + fi + ;; +]) + +AC_DEFUN([gl_CHECK_FUNCS_CASE_FOR_MACOS], +[ + darwin*) + if test "x$gl_cv_compiler_check_future_option" != "xnone"; then + dnl Use a compile test, not a link test. + saved_ac_compile="$ac_compile" + ac_compile="$ac_compile $gl_cv_compiler_check_future_option" + saved_ac_compile_for_check_decl="$ac_compile_for_check_decl" + ac_compile_for_check_decl="$ac_compile_for_check_decl $gl_cv_compiler_check_future_option" + unset [ac_cv_have_decl_][$1] + AC_CHECK_DECL([$1], , , [$2]) + ac_compile="$saved_ac_compile" + ac_compile_for_check_decl="$saved_ac_compile_for_check_decl" + [ac_cv_func_][$1]="$[ac_cv_have_decl_][$1]" + if test $[ac_cv_func_][$1] = yes; then + [gl_cv_onwards_func_][$1]=yes + else + unset [ac_cv_have_decl_][$1] + AC_CHECK_DECL([$1], , , [$2]) + if test $[ac_cv_have_decl_][$1] = yes; then + [gl_cv_onwards_func_][$1]='future OS version' + else + [gl_cv_onwards_func_][$1]=no + fi + fi + else + AC_CHECK_FUNC([$1]) + [gl_cv_onwards_func_][$1]=$[ac_cv_func_][$1] + fi + ;; +]) + +AC_DEFUN([gl_CHECK_FUNCS_SET_RESULTS], +[ + case "$[gl_cv_onwards_func_][$1]" in + future*) [ac_cv_func_][$1]=no ;; + *) [ac_cv_func_][$1]=$[gl_cv_onwards_func_][$1] ;; + esac + if test $[ac_cv_func_][$1] = yes; then + AC_DEFINE([HAVE_]m4_translit([[$1]], + [abcdefghijklmnopqrstuvwxyz], + [ABCDEFGHIJKLMNOPQRSTUVWXYZ]), + [1], [Define to 1 if you have the `$1' function.]) + fi +]) + +dnl gl_CHECK_FUNCS_ANDROID([func], [[#include ]]) +dnl is like AC_CHECK_FUNCS([func]), taking into account a portability problem +dnl on Android. +dnl +dnl When code is compiled on Android, it is in the context of a certain +dnl "Android API level", which indicates the minimum version of Android on +dnl which the app can be installed. In other words, you don't compile for a +dnl specific version of Android. You compile for all versions of Android, +dnl onwards from the given API level. +dnl Thus, the question "does the OS have the function func" has three possible +dnl answers: +dnl - yes, in all versions starting from the given API level, +dnl - no, in no version, +dnl - not in the given API level, but in a later version of Android. +dnl +dnl In detail, this works as follows: +dnl If func was added to Android API level, say, 28, then the libc.so has the +dnl symbol func always, whereas the header file declares func +dnl conditionally: +dnl #if __ANDROID_API__ >= 28 +dnl ... func (...) __INTRODUCED_IN(28); +dnl #endif +dnl Thus, when compiling with "clang -target armv7a-unknown-linux-android28", +dnl the function func is declared and exists in libc. +dnl Whereas when compiling with "clang -target armv7a-unknown-linux-android27", +dnl the function func is not declared but exists in libc. +dnl +dnl This macro sets two variables: +dnl - gl_cv_onwards_func_ to yes / no / "future OS version" +dnl - ac_cv_func_ to yes / no / no +dnl The first variable allows to distinguish all three cases. +dnl The second variable is set, so that an invocation +dnl gl_CHECK_FUNCS_ANDROID([func], [[#include ]]) +dnl can be used as a drop-in replacement for +dnl AC_CHECK_FUNCS([func]). +AC_DEFUN([gl_CHECK_FUNCS_ANDROID], +[ + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_CACHE_CHECK([for [$1]], + [[gl_cv_onwards_func_][$1]], + [gl_SILENT([ + case "$host_os" in + gl_CHECK_FUNCS_CASE_FOR_ANDROID([$1], [$2]) + gl_CHECK_FUNCS_DEFAULT_CASE([$1]) + esac + ]) + ]) + gl_CHECK_FUNCS_SET_RESULTS([$1]) +]) + +dnl gl_CHECK_FUNCS_MACOS([func], [[#include ]]) +dnl is like AC_CHECK_FUNCS([func]), taking into account a portability problem +dnl on macOS. +dnl +dnl When code is compiled on macOS, it is in the context of a certain minimum +dnl macOS version, that can be set through the option '-mmacosx-version-min='. +dnl In other words, you don't compile for a specific version of macOS. You +dnl compile for all versions of macOS, onwards from the given version. +dnl Thus, the question "does the OS have the function func" has three possible +dnl answers: +dnl - yes, in all versions starting from the given version, +dnl - no, in no version, +dnl - not in the given version, but in a later version of macOS. +dnl +dnl In detail, this works as follows: +dnl If func was added to, say, macOS version 13, then the libc has the +dnl symbol func always, whereas the header file declares func +dnl conditionally with a special availability attribute: +dnl ... func (...) __attribute__((availability(macos,introduced=13.0))); +dnl Thus, when compiling with "clang mmacosx-version-min=13", there is no +dnl warning about the use of func, and the resulting binary +dnl - runs fine on macOS 13, +dnl - aborts with a dyld "Symbol not found" message on macOS 12. +dnl Whereas, when compiling with "clang mmacosx-version-min=12", there is a +dnl warning: 'func' is only available on macOS 13.0 or newer +dnl [-Wunguarded-availability-new], +dnl and the resulting binary +dnl - runs fine on macOS 13, +dnl - crashes with a SIGSEGV (signal 11) on macOS 12. +dnl +dnl This macro sets two variables: +dnl - gl_cv_onwards_func_ to yes / no / "future OS version" +dnl - ac_cv_func_ to yes / no / no +dnl The first variable allows to distinguish all three cases. +dnl The second variable is set, so that an invocation +dnl gl_CHECK_FUNCS_MACOS([func], [[#include ]]) +dnl can be used as a drop-in replacement for +dnl AC_CHECK_FUNCS([func]). +AC_DEFUN([gl_CHECK_FUNCS_MACOS], +[ + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_REQUIRE([gl_PREPARE_CHECK_FUNCS_MACOS]) + AC_CACHE_CHECK([for [$1]], + [[gl_cv_onwards_func_][$1]], + [gl_SILENT([ + case "$host_os" in + gl_CHECK_FUNCS_CASE_FOR_MACOS([$1], [$2]) + gl_CHECK_FUNCS_DEFAULT_CASE([$1]) + esac + ]) + ]) + gl_CHECK_FUNCS_SET_RESULTS([$1]) +]) + +dnl gl_CHECK_FUNCS_ANDROID_MACOS([func], [[#include ]]) +dnl is like AC_CHECK_FUNCS([func]), taking into account a portability problem +dnl on Android and on macOS. +dnl It is the combination of gl_CHECK_FUNCS_ANDROID and gl_CHECK_FUNCS_MACOS. +AC_DEFUN([gl_CHECK_FUNCS_ANDROID_MACOS], +[ + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_REQUIRE([gl_PREPARE_CHECK_FUNCS_MACOS]) + AC_CACHE_CHECK([for [$1]], + [[gl_cv_onwards_func_][$1]], + [gl_SILENT([ + case "$host_os" in + gl_CHECK_FUNCS_CASE_FOR_ANDROID([$1], [$2]) + gl_CHECK_FUNCS_CASE_FOR_MACOS([$1], [$2]) + gl_CHECK_FUNCS_DEFAULT_CASE([$1]) + esac + ]) + ]) + gl_CHECK_FUNCS_SET_RESULTS([$1]) +]) + +dnl Expands to some code for use in .c programs that, on native Windows, defines +dnl the Microsoft deprecated alias function names to the underscore-prefixed +dnl actual function names. With this macro, these function names are available +dnl without linking with '-loldnames' and without generating warnings. +dnl Usage: Use it after all system header files are included. +dnl #include <...> +dnl #include <...> +dnl ]GL_MDA_DEFINES[ +dnl ... +AC_DEFUN([GL_MDA_DEFINES],[ +AC_REQUIRE([_GL_MDA_DEFINES]) +[$gl_mda_defines] +]) +AC_DEFUN([_GL_MDA_DEFINES], +[gl_mda_defines=' +#if defined _WIN32 && !defined __CYGWIN__ +#define access _access +#define chdir _chdir +#define chmod _chmod +#define close _close +#define creat _creat +#define dup _dup +#define dup2 _dup2 +#define ecvt _ecvt +#define execl _execl +#define execle _execle +#define execlp _execlp +#define execv _execv +#define execve _execve +#define execvp _execvp +#define execvpe _execvpe +#define fcloseall _fcloseall +#define fcvt _fcvt +#define fdopen _fdopen +#define fileno _fileno +#define gcvt _gcvt +#define getcwd _getcwd +#define getpid _getpid +#define getw _getw +#define isatty _isatty +#define j0 _j0 +#define j1 _j1 +#define jn _jn +#define lfind _lfind +#define lsearch _lsearch +#define lseek _lseek +#define memccpy _memccpy +#define mkdir _mkdir +#define mktemp _mktemp +#define open _open +#define putenv _putenv +#define putw _putw +#define read _read +#define rmdir _rmdir +#define strdup _strdup +#define swab _swab +#define tempnam _tempnam +#define tzset _tzset +#define umask _umask +#define unlink _unlink +#define utime _utime +#define wcsdup _wcsdup +#define write _write +#define y0 _y0 +#define y1 _y1 +#define yn _yn +#endif +' +]) diff --git a/m4/zzgnulib.m4 b/m4/zzgnulib.m4 new file mode 100644 index 0000000..343bda5 --- /dev/null +++ b/m4/zzgnulib.m4 @@ -0,0 +1,25 @@ +# zzgnulib.m4 +# serial 1 +dnl Copyright (C) 2020-2025 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. +dnl This file is offered as-is, without any warranty. + +dnl This file must be named something that sorts after all other +dnl package- or gnulib-provided .m4 files - at least for those packages +dnl that redefine AC_PROG_CC. + +dnl Redefine AC_PROG_CC so that it ends with invocations of gl_COMPILER_CLANG +dnl and gl_COMPILER_PREPARE_CHECK_DECL. +m4_define([AC_PROG_CC], + m4_defn([AC_PROG_CC])[ +gl_COMPILER_CLANG +gl_COMPILER_PREPARE_CHECK_DECL +]) + +# gl_ZZGNULIB +# ----------- +# Witness macro that this file has been included. Needed to force +# Automake to include this file after all other gnulib .m4 files. +AC_DEFUN([gl_ZZGNULIB]) diff --git a/main.c b/main.c index 9909e38..c06d0d1 100644 --- a/main.c +++ b/main.c @@ -1018,7 +1018,7 @@ node_free (void *p) if (n->parent) { if (n->parent->children && hash_lookup (n->parent->children, n) == n) - hash_delete (n->parent->children, n); + hash_remove (n->parent->children, n); n->parent->loaded = 0; n->parent = NULL; } @@ -1078,7 +1078,7 @@ drop_node_from_ino (Hash_table *inodes, struct ovl_node *node) if (ino->lookups == 0) { - hash_delete (inodes, ino); + hash_remove (inodes, ino); inode_free (ino); return; } @@ -1308,7 +1308,7 @@ do_forget (struct ovl_data *lo, fuse_ino_t ino, uint64_t nlookup) i->lookups -= nlookup; if (i->lookups <= 0) { - hash_delete (lo->inodes, i); + hash_remove (lo->inodes, i); inode_free (i); } return true; @@ -1659,12 +1659,12 @@ insert_node (struct ovl_node *parent, struct ovl_node *item, bool replace) if (prev_parent) { if (hash_lookup (prev_parent->children, item) == item) - hash_delete (prev_parent->children, item); + hash_remove (prev_parent->children, item); } if (replace) { - old = hash_delete (parent->children, item); + old = hash_remove (parent->children, item); if (old) node_free (old); } @@ -1787,7 +1787,7 @@ load_dir (struct ovl_data *lo, struct ovl_node *n, struct ovl_layer *layer, char continue; else { - hash_delete (n->children, child); + hash_remove (n->children, child); node_free (child); child = NULL; } @@ -3496,7 +3496,7 @@ do_rm (fuse_req_t req, fuse_ino_t parent, const char *name, bool dirp) node_set_name (&key, (char *) name); - rm = hash_delete (pnode->children, &key); + rm = hash_remove (pnode->children, &key); fuse_lowlevel_notify_inval_inode (lo->se, node_to_inode (node), -1, 0); if (rm) { @@ -4623,8 +4623,8 @@ ovl_rename_exchange (fuse_req_t req, fuse_ino_t parent, const char *name, if (ret < 0) goto error; - rm1 = hash_delete (destpnode->children, destnode); - rm2 = hash_delete (pnode->children, node); + rm1 = hash_remove (destpnode->children, destnode); + rm2 = hash_remove (pnode->children, node); tmp = node->path; node->path = destnode->path; @@ -4854,7 +4854,7 @@ ovl_rename_direct (fuse_req_t req, fuse_ino_t parent, const char *name, if (delete_whiteout (lo, destfd, NULL, newname) < 0) goto error; - hash_delete (pnode->children, node); + hash_remove (pnode->children, node); free (node->name); node_set_name (node, strdup (newname));