Prettify CMake checks for compiler switches

1 files changed, 59 insertions, 0 deletions

diff --git a/cmake/CheckCCompilerFlag.cmake b/cmake/CheckCCompilerFlag.cmake
new file mode 100644
index 00000000..8b2361aa
--- /dev/null
+++ b/cmake/CheckCCompilerFlag.cmake
@@ -0,0 +1,59 @@
+# - Check if the C source code provided in the SOURCE argument compiles.
+# CHECK_C_SOURCE_COMPILES(SOURCE VAR)
+#
+#  FLAG   - compiler flag to check
+#  VAR    - variable to store whether the source code compiled
+#
+# The following variables may be set before calling this macro to
+# modify the way the check is run:
+#
+#  CMAKE_REQUIRED_FLAGS = string of compile command line flags
+#  CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
+#  CMAKE_REQUIRED_INCLUDES = list of include directories
+#  CMAKE_REQUIRED_LIBRARIES = list of libraries to link
+
+MACRO(CHECK_C_COMPILER_FLAG FLAG VAR)
+  IF("${VAR}" MATCHES "^${VAR}$")
+    SET(MACRO_CHECK_FUNCTION_DEFINITIONS
+      "${FLAG} ${CMAKE_REQUIRED_FLAGS}")
+    IF(CMAKE_REQUIRED_LIBRARIES)
+      SET(CHECK_C_COMPILER_FLAG_ADD_LIBRARIES
+        "-DLINK_LIBRARIES:STRING=${CMAKE_REQUIRED_LIBRARIES}")
+    ELSE(CMAKE_REQUIRED_LIBRARIES)
+      SET(CHECK_C_COMPILER_FLAG_ADD_LIBRARIES)
+    ENDIF(CMAKE_REQUIRED_LIBRARIES)
+    IF(CMAKE_REQUIRED_INCLUDES)
+      SET(CHECK_C_COMPILER_FLAG_ADD_INCLUDES
+        "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}")
+    ELSE(CMAKE_REQUIRED_INCLUDES)
+      SET(CHECK_C_COMPILER_FLAG_ADD_INCLUDES)
+    ENDIF(CMAKE_REQUIRED_INCLUDES)
+    FILE(WRITE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.c"
+      "int main() {return 0;}\n")
+
+    MESSAGE(STATUS "Checking if C compiler supports ${FLAG}")
+    TRY_COMPILE(${VAR}
+      ${CMAKE_BINARY_DIR}
+      ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.c
+      COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
+      CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS}
+      "${CHECK_C_COMPILER_FLAG_ADD_LIBRARIES}"
+      "${CHECK_C_COMPILER_FLAG_ADD_INCLUDES}"
+      OUTPUT_VARIABLE OUTPUT)
+    IF(${VAR})
+      SET(${VAR} 1 CACHE INTERNAL "Test ${VAR}")
+      MESSAGE(STATUS "Checking if C compiler supports ${FLAG} - Success")
+      FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+        "Performing C SOURCE FILE Test ${VAR} succeded with the following output:\n"
+        "${OUTPUT}\n"
+        "Source file was:\n${SOURCE}\n")
+    ELSE(${VAR})
+      MESSAGE(STATUS "Checking if C compiler supports ${FLAG} - Failed")
+      SET(${VAR} "" CACHE INTERNAL "Test ${VAR}")
+      FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+        "Performing C SOURCE FILE Test ${VAR} failed with the following output:\n"
+        "${OUTPUT}\n"
+        "Source file was:\n${SOURCE}\n")
+    ENDIF(${VAR})
+  ENDIF("${VAR}" MATCHES "^${VAR}$")
+ENDMACRO(CHECK_C_COMPILER_FLAG)