CMake/Modules/CMakeTestCCompiler.cmake

# This file is used by EnableLanguage in cmGlobalGenerator to
# determine that that selected C compiler can actually compile
# and like the most basic of programs.   If not, a fatel error
# is set and cmake stops processing commands and will not generate
# any makefiles or projects.
IF(NOT CMAKE_C_COMPILER_WORKS)
  MESSAGE(STATUS "Check for working C compiler: ${CMAKE_C_COMPILER}")
  WRITE_FILE(${CMAKE_BINARY_DIR}/CMakeTmp/testCCompiler.c "int main(){return 0;}")
  TRY_COMPILE(CMAKE_C_COMPILER_WORKS ${CMAKE_BINARY_DIR} 
              ${CMAKE_BINARY_DIR}/CMakeTmp/testCCompiler.c
              OUTPUT_VARIABLE OUTPUT)
ENDIF(NOT CMAKE_C_COMPILER_WORKS)

IF(NOT CMAKE_C_COMPILER_WORKS)
   MESSAGE(STATUS "Check for working C compiler: ${CMAKE_C_COMPILER} -- broken")
   MESSAGE(FATAL_ERROR "The C compiler \"${CMAKE_C_COMPILER}\" "
                      "is not able to compile a simple tests program.\nIt fails "
                      "with the following output:\n ${OUTPUT}\n\n"
                      "CMake will not be able to correctly generate this project.")
ELSE(NOT CMAKE_C_COMPILER_WORKS)
  MESSAGE(STATUS "Check for working C compiler: ${CMAKE_C_COMPILER} -- works")
ENDIF(NOT CMAKE_C_COMPILER_WORKS)