From bee32f54dad912d15e952ffd0a91b95a376bbe7e Mon Sep 17 00:00:00 2001
From: Dmitry Marakasov <amdmi3@amdmi3.ru>
Date: Thu, 17 Sep 2015 16:44:59 +0300
Subject: [PATCH] More fixes for compiler feature detection

---
 CMakeLists.txt                          |  8 ++++----
 cmake/AppendCXXFlagIfSupported.cmake    |  5 +++--
 cmake/CheckCompile.cmake                | 25 +++++++++++++++----------
 cmake/attribute_deprecated_test.cc      |  7 -------
 cmake/std_experimental_optional_test.cc |  8 --------
 5 files changed, 22 insertions(+), 31 deletions(-)
 delete mode 100644 cmake/attribute_deprecated_test.cc
 delete mode 100644 cmake/std_experimental_optional_test.cc

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f439048..a232726 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -80,13 +80,13 @@ INCLUDE_DIRECTORIES(SYSTEM ${SDL2_ALL_INCLUDE_DIRS})
 INCLUDE(CheckCompile)
 CHECK_COMPILE(
 	SDL2PP_WITH_EXPERIMENTAL_OPTIONAL
-	${PROJECT_SOURCE_DIR}/cmake/std_experimental_optional_test.cc
-	"Checking for experimental/optional header"
+	"#include <experimental/optional>\nint main() { std::experimental::optional<int> o; return !o; }"
+	"experimental/optional header"
 )
 CHECK_COMPILE(
 	SDL2PP_WITH_DEPRECATED
-	${PROJECT_SOURCE_DIR}/cmake/attribute_deprecated_test.cc
-	"Checking for [[deprecated]] attribute"
+	"[[deprecated]]\nstatic void f() {} int main() { return 0; }"
+	"[[deprecated]] attribute"
 )
 
 SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${SDL2PP_WARNINGS}")
diff --git a/cmake/AppendCXXFlagIfSupported.cmake b/cmake/AppendCXXFlagIfSupported.cmake
index 7421109..ee38818 100644
--- a/cmake/AppendCXXFlagIfSupported.cmake
+++ b/cmake/AppendCXXFlagIfSupported.cmake
@@ -2,11 +2,12 @@ INCLUDE(CheckCXXCompilerFlag)
 
 MACRO(APPEND_CXX_FLAG_IF_SUPPORTED FLAG VARIABLE)
 	UNSET(HAS_FLAG CACHE)
+	SET(SAVED_CMAKE_REQUIRED_QUIET ${CMAKE_REQUIRED_QUIET})
 	SET(CMAKE_REQUIRED_QUIET YES)
 	CHECK_CXX_COMPILER_FLAG(${FLAG} HAS_FLAG)
-	SET(CMAKE_REQUIRED_QUIET NO)
+	SET(CMAKE_REQUIRED_QUIET ${SAVED_CMAKE_REQUIRED_QUIET})
 	IF(HAS_FLAG)
-		SET(VARIABLE "${VARIABLE} ${FLAG}")
+		SET(${VARIABLE} "${${VARIABLE}} ${FLAG}")
 		MESSAGE(STATUS "Checking for ${FLAG}: yes")
 	ELSE(HAS_FLAG)
 		MESSAGE(STATUS "Checking for ${FLAG}: no")
diff --git a/cmake/CheckCompile.cmake b/cmake/CheckCompile.cmake
index ce52160..5f93361 100644
--- a/cmake/CheckCompile.cmake
+++ b/cmake/CheckCompile.cmake
@@ -1,11 +1,16 @@
-MACRO(CHECK_COMPILE RESULT_VAR SOURCE_FILE DESCRIPTION)
-	SET(SAVED_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-	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)
-		MESSAGE(STATUS "${DESCRIPTION}: no")
-	ENDIF(RESULT_VAR)
-	SET(CMAKE_CXX_FLAGS "${SAVED_CXX_FLAGS}")
+INCLUDE(CheckCXXSourceCompiles)
+
+MACRO(CHECK_COMPILE RESULT_VAR CODE DESCRIPTION)
+	SET(SAVED_CMAKE_REQUIRED_QUIET "${CMAKE_REQUIRED_QUIET}")
+	SET(SAVED_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
+	SET(CMAKE_REQUIRED_QUIET YES)
+	SET(CMAKE_REQUIRED_FLAGS "${SDL2PP_WERROR_FLAG}")
+	CHECK_CXX_SOURCE_COMPILES("${CODE}" ${RESULT_VAR})
+	SET(CMAKE_REQUIRED_QUIET "${SAVED_CMAKE_REQUIRED_QUIET}")
+	SET(CMAKE_REQUIRED_FLAGS "${SAVED_CMAKE_REQUIRED_FLAGS}")
+	IF(${RESULT_VAR})
+		MESSAGE(STATUS "Checking for ${DESCRIPTION}: yes")
+	ELSE(${RESULT_VAR})
+		MESSAGE(STATUS "Checking for ${DESCRIPTION}: no")
+	ENDIF(${RESULT_VAR})
 ENDMACRO(CHECK_COMPILE)
diff --git a/cmake/attribute_deprecated_test.cc b/cmake/attribute_deprecated_test.cc
deleted file mode 100644
index 77e0e49..0000000
--- a/cmake/attribute_deprecated_test.cc
+++ /dev/null
@@ -1,7 +0,0 @@
-[[deprecated]]
-static void f() {
-}
-
-int main() {
-	return 0;
-}
diff --git a/cmake/std_experimental_optional_test.cc b/cmake/std_experimental_optional_test.cc
deleted file mode 100644
index 8d77d5d..0000000
--- a/cmake/std_experimental_optional_test.cc
+++ /dev/null
@@ -1,8 +0,0 @@
-#include <experimental/optional>
-#include <string>
-
-int main() {
-	std::experimental::optional<std::string> o;
-
-	return !o;
-}