cmake/CheckCCompilerFlag.cmake

   1 # - Check if the C source code provided in the SOURCE argument compiles.
   2 # CHECK_C_SOURCE_COMPILES(SOURCE VAR)
   3 #
   4 #  FLAG   - compiler flag to check
   5 #  VAR    - variable to store whether the source code compiled
   6 #
   7 # The following variables may be set before calling this macro to
   8 # modify the way the check is run:
   9 #
  10 #  CMAKE_REQUIRED_FLAGS = string of compile command line flags
  11 #  CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
  12 #  CMAKE_REQUIRED_INCLUDES = list of include directories
  13 #  CMAKE_REQUIRED_LIBRARIES = list of libraries to link
  14
  15 MACRO(CHECK_C_COMPILER_FLAG FLAG VAR)
  16   IF("${VAR}" MATCHES "^${VAR}$")
  17     SET(MACRO_CHECK_FUNCTION_DEFINITIONS
  18       "${FLAG} ${CMAKE_REQUIRED_FLAGS}")
  19     IF(CMAKE_REQUIRED_LIBRARIES)
  20       SET(CHECK_C_COMPILER_FLAG_ADD_LIBRARIES
  21         "-DLINK_LIBRARIES:STRING=${CMAKE_REQUIRED_LIBRARIES}")
  22     ELSE(CMAKE_REQUIRED_LIBRARIES)
  23       SET(CHECK_C_COMPILER_FLAG_ADD_LIBRARIES)
  24     ENDIF(CMAKE_REQUIRED_LIBRARIES)
  25     IF(CMAKE_REQUIRED_INCLUDES)
  26       SET(CHECK_C_COMPILER_FLAG_ADD_INCLUDES
  27         "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}")
  28     ELSE(CMAKE_REQUIRED_INCLUDES)
  29       SET(CHECK_C_COMPILER_FLAG_ADD_INCLUDES)
  30     ENDIF(CMAKE_REQUIRED_INCLUDES)
  31     FILE(WRITE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.c"
  32       "int main() {return 0;}\n")
  33
  34     MESSAGE(STATUS "Checking if C compiler supports ${FLAG}")
  35     TRY_COMPILE(${VAR}
  36       ${CMAKE_BINARY_DIR}
  37       ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.c
  38       COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
  39       CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS}
  40       "${CHECK_C_COMPILER_FLAG_ADD_LIBRARIES}"
  41       "${CHECK_C_COMPILER_FLAG_ADD_INCLUDES}"
  42       OUTPUT_VARIABLE OUTPUT)
  43     IF(${VAR})
  44       SET(${VAR} 1 CACHE INTERNAL "Test ${VAR}")
  45       MESSAGE(STATUS "Checking if C compiler supports ${FLAG} - Success")
  46       FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
  47         "Performing C SOURCE FILE Test ${VAR} succeded with the following output:\n"
  48         "${OUTPUT}\n"
  49         "Source file was:\n${SOURCE}\n")
  50     ELSE(${VAR})
  51       MESSAGE(STATUS "Checking if C compiler supports ${FLAG} - Failed")
  52       SET(${VAR} "" CACHE INTERNAL "Test ${VAR}")
  53       FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
  54         "Performing C SOURCE FILE Test ${VAR} failed with the following output:\n"
  55         "${OUTPUT}\n"
  56         "Source file was:\n${SOURCE}\n")
  57     ENDIF(${VAR})
  58   ENDIF("${VAR}" MATCHES "^${VAR}$")
  59 ENDMACRO(CHECK_C_COMPILER_FLAG)