From 1e6cefa86d3452754d34a2f2a2d1fecdee324bca Mon Sep 17 00:00:00 2001
From: Dmitry Marakasov <amdmi3@amdmi3.ru>
Date: Thu, 17 Sep 2015 15:18:56 +0300
Subject: [PATCH] Add macro to check and enable C++ flag, add some clang
 warnings

---
 CMakeLists.txt                       |  5 +++++
 cmake/EnableCXXFlagIfSupported.cmake | 14 ++++++++++++++
 tests/CMakeLists.txt                 |  7 ++-----
 3 files changed, 21 insertions(+), 5 deletions(-)
 create mode 100644 cmake/EnableCXXFlagIfSupported.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a705604..65a2f1b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -64,6 +64,11 @@ IF(MSVC)
 ELSE(MSVC)
 	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=${SDL2PP_CXXSTD} -Wall -Wextra -pedantic")
 	SET(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)
 ENDIF(MSVC)
 
 LIST(REMOVE_DUPLICATES SDL2_ALL_INCLUDE_DIRS)
diff --git a/cmake/EnableCXXFlagIfSupported.cmake b/cmake/EnableCXXFlagIfSupported.cmake
new file mode 100644
index 0000000..fb37aed
--- /dev/null
+++ b/cmake/EnableCXXFlagIfSupported.cmake
@@ -0,0 +1,14 @@
+INCLUDE(CheckCXXCompilerFlag)
+
+MACRO(ENABLE_CXX_FLAG_IF_SUPPORTED FLAG)
+	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}")
+		MESSAGE(STATUS "Checking for ${FLAG}: yes")
+	ELSE(HAS_FLAG)
+		MESSAGE(STATUS "Checking for ${FLAG}: no")
+	ENDIF(HAS_FLAG)
+ENDMACRO(ENABLE_CXX_FLAG_IF_SUPPORTED)
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 0d4ef8c..b2d2831 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -17,11 +17,8 @@ IF(SDL2PP_WITH_MIXER)
 ENDIF(SDL2PP_WITH_MIXER)
 
 # disable self-move warning: it's deliberately used in tests
-INCLUDE(CheckCXXCompilerFlag)
-CHECK_CXX_COMPILER_FLAG("-Wno-self-move" COMPILER_SUPPORTS_WNOSELFMOVE)
-IF(COMPILER_SUPPORTS_WNOSELFMOVE)
-	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-self-move")
-ENDIF(COMPILER_SUPPORTS_WNOSELFMOVE)
+INCLUDE(EnableCXXFlagIfSupported)
+ENABLE_CXX_FLAG_IF_SUPPORTED(-Wno-self-move)
 
 ADD_DEFINITIONS(-DTESTDATA_DIR="${PROJECT_SOURCE_DIR}/testdata")