From be5bc9d1dea0eb443e91457f78b6eee5261d1f36 Mon Sep 17 00:00:00 2001
From: Dmitry Marakasov <amdmi3@amdmi3.ru>
Date: Thu, 17 Sep 2015 16:02:36 +0300
Subject: [PATCH] Revamp compiler flag support detection logic

---
 CMakeLists.txt                                | 28 ++++++++++---------
 ...d.cmake => AppendCXXFlagIfSupported.cmake} |  6 ++--
 cmake/CheckCompile.cmake                      | 10 +++----
 cmake/attribute_deprecated_test.cc            |  2 +-
 tests/CMakeLists.txt                          |  4 +--
 5 files changed, 26 insertions(+), 24 deletions(-)
 rename cmake/{EnableCXXFlagIfSupported.cmake => AppendCXXFlagIfSupported.cmake} (69%)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 520bca0..f439048 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -59,16 +59,17 @@ FIND_PACKAGE(Doxygen)
 
 # compiler flags & definitions
 IF(MSVC)
-	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W3")
-	SET(WERROR_FLAG "/WX")
+	SET(SDL2PP_WARNINGS "${SDL2PP_WARNINGS} /W3")
+	SET(SDL2PP_WERROR_FLAG "/WX")
 ELSE(MSVC)
-	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=${SDL2PP_CXXSTD} -Wall -Wextra -pedantic")
-	SET(WERROR_FLAG "-Werror")
+	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=${SDL2PP_CXXSTD}")
+	SET(SDL2PP_WARNINGS "${SDL2PP_WARNINGS} -Wall -Wextra -pedantic")
+	SET(SDL2PP_WERROR_FLAG "-Werror")
 
-	INCLUDE(EnableCXXFlagIfSupported)
-	ENABLE_CXX_FLAG_IF_SUPPORTED(-Wmissing-prototypes)
-	ENABLE_CXX_FLAG_IF_SUPPORTED(-Wtautological-compare)
-	ENABLE_CXX_FLAG_IF_SUPPORTED(-Wshorten-64-to-32)
+	INCLUDE(AppendCXXFlagIfSupported)
+	APPEND_CXX_FLAG_IF_SUPPORTED(-Wmissing-prototypes SDL2PP_WARNINGS)
+	APPEND_CXX_FLAG_IF_SUPPORTED(-Wtautological-compare SDL2PP_WARNINGS)
+	APPEND_CXX_FLAG_IF_SUPPORTED(-Wshorten-64-to-32 SDL2PP_WARNINGS)
 ENDIF(MSVC)
 
 LIST(REMOVE_DUPLICATES SDL2_ALL_INCLUDE_DIRS)
@@ -76,11 +77,6 @@ LIST(REMOVE_DUPLICATES SDL2_ALL_INCLUDE_DIRS)
 INCLUDE_DIRECTORIES(BEFORE ${PROJECT_SOURCE_DIR})
 INCLUDE_DIRECTORIES(SYSTEM ${SDL2_ALL_INCLUDE_DIRS})
 
-IF(SDL2PP_WITH_WERROR)
-	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${WERROR_FLAG}")
-ENDIF(SDL2PP_WITH_WERROR)
-
-# platform checks
 INCLUDE(CheckCompile)
 CHECK_COMPILE(
 	SDL2PP_WITH_EXPERIMENTAL_OPTIONAL
@@ -93,6 +89,12 @@ CHECK_COMPILE(
 	"Checking for [[deprecated]] attribute"
 )
 
+SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${SDL2PP_WARNINGS}")
+
+IF(SDL2PP_WITH_WERROR)
+	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${SDL2PP_WERROR_FLAG}")
+ENDIF(SDL2PP_WITH_WERROR)
+
 # config.h
 CONFIGURE_FILE(
 	SDL2pp/Config.hh.in
diff --git a/cmake/EnableCXXFlagIfSupported.cmake b/cmake/AppendCXXFlagIfSupported.cmake
similarity index 69%
rename from cmake/EnableCXXFlagIfSupported.cmake
rename to cmake/AppendCXXFlagIfSupported.cmake
index fb37aed..7421109 100644
--- a/cmake/EnableCXXFlagIfSupported.cmake
+++ b/cmake/AppendCXXFlagIfSupported.cmake
@@ -1,14 +1,14 @@
 INCLUDE(CheckCXXCompilerFlag)
 
-MACRO(ENABLE_CXX_FLAG_IF_SUPPORTED FLAG)
+MACRO(APPEND_CXX_FLAG_IF_SUPPORTED FLAG VARIABLE)
 	UNSET(HAS_FLAG CACHE)
 	SET(CMAKE_REQUIRED_QUIET YES)
 	CHECK_CXX_COMPILER_FLAG(${FLAG} HAS_FLAG)
 	SET(CMAKE_REQUIRED_QUIET NO)
 	IF(HAS_FLAG)
-		SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${FLAG}")
+		SET(VARIABLE "${VARIABLE} ${FLAG}")
 		MESSAGE(STATUS "Checking for ${FLAG}: yes")
 	ELSE(HAS_FLAG)
 		MESSAGE(STATUS "Checking for ${FLAG}: no")
 	ENDIF(HAS_FLAG)
-ENDMACRO(ENABLE_CXX_FLAG_IF_SUPPORTED)
+ENDMACRO(APPEND_CXX_FLAG_IF_SUPPORTED)
diff --git a/cmake/CheckCompile.cmake b/cmake/CheckCompile.cmake
index 33e72cb..ce52160 100644
--- a/cmake/CheckCompile.cmake
+++ b/cmake/CheckCompile.cmake
@@ -1,11 +1,11 @@
 MACRO(CHECK_COMPILE RESULT_VAR SOURCE_FILE DESCRIPTION)
 	SET(SAVED_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${WERROR_FLAG}")
-	TRY_COMPILE(${RESULT_VAR} ${CMAKE_BINARY_DIR} ${SOURCE_FILE})
-	IF(${RESULT_VAR})
+	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${SDL2PP_WERROR_FLAG}")
+	TRY_COMPILE(RESULT_VAR ${CMAKE_BINARY_DIR} ${SOURCE_FILE})
+	IF(RESULT_VAR)
 		MESSAGE(STATUS "${DESCRIPTION}: yes")
-	ELSE(${RESULT_VAR})
+	ELSE(RESULT_VAR)
 		MESSAGE(STATUS "${DESCRIPTION}: no")
-	ENDIF(${RESULT_VAR})
+	ENDIF(RESULT_VAR)
 	SET(CMAKE_CXX_FLAGS "${SAVED_CXX_FLAGS}")
 ENDMACRO(CHECK_COMPILE)
diff --git a/cmake/attribute_deprecated_test.cc b/cmake/attribute_deprecated_test.cc
index fe6b4af..77e0e49 100644
--- a/cmake/attribute_deprecated_test.cc
+++ b/cmake/attribute_deprecated_test.cc
@@ -1,5 +1,5 @@
 [[deprecated]]
-void f() {
+static void f() {
 }
 
 int main() {
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index b2d2831..656b876 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -17,8 +17,8 @@ IF(SDL2PP_WITH_MIXER)
 ENDIF(SDL2PP_WITH_MIXER)
 
 # disable self-move warning: it's deliberately used in tests
-INCLUDE(EnableCXXFlagIfSupported)
-ENABLE_CXX_FLAG_IF_SUPPORTED(-Wno-self-move)
+INCLUDE(AppendCXXFlagIfSupported)
+APPEND_CXX_FLAG_IF_SUPPORTED(-Wno-self-move CMAKE_CXX_FLAGS)
 
 ADD_DEFINITIONS(-DTESTDATA_DIR="${PROJECT_SOURCE_DIR}/testdata")