Modules/CheckFunctionExists.cmake

   1 #
   2 # Check if the function exists.
   3 #
   4 # CHECK_FUNCTION_EXISTS - macro which checks if the function exists
   5 # FUNCTION - the name of the function
   6 # VARIABLE - variable to store the result
   7 #
   8
   9 MACRO(CHECK_FUNCTION_EXISTS FUNCTION VARIABLE)
  10   IF("${VARIABLE}" MATCHES "^${VARIABLE}$")
  11     SET(MACRO_CHECK_FUNCTION_DEFINITIONS
  12       "-DCHECK_FUNCTION_EXISTS=${FUNCTION} ${CMAKE_REQUIRED_FLAGS}")
  13     MESSAGE(STATUS "Looking for ${FUNCTION}")
  14     IF(CMAKE_REQUIRED_LIBRARIES)
  15       SET(CHECK_FUNCTION_EXISTS_ADD_LIBRARIES
  16         "-DLINK_LIBRARIES:STRING=${CMAKE_REQUIRED_LIBRARIES}")
  17     ENDIF(CMAKE_REQUIRED_LIBRARIES)
  18     TRY_COMPILE(${VARIABLE}
  19       ${CMAKE_BINARY_DIR}
  20       ${CMAKE_ROOT}/Modules/CheckFunctionExists.c
  21       CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS}
  22       "${CHECK_FUNCTION_EXISTS_ADD_LIBRARIES}"
  23       OUTPUT_VARIABLE OUTPUT)
  24     IF(${VARIABLE})
  25       SET(${VARIABLE} 1 CACHE INTERNAL "Have function ${FUNCTION}")
  26       MESSAGE(STATUS "Looking for ${FUNCTION} - found")
  27       FILE(APPEND ${CMAKE_BINARY_DIR}/CMakeOutput.log
  28         "Determining if the function ${FUNCTION} exists passed with the following output:\n"
  29         "${OUTPUT}\n\n")
  30     ELSE(${VARIABLE})
  31       MESSAGE(STATUS "Looking for ${FUNCTION} - not found")
  32       SET(${VARIABLE} "" CACHE INTERNAL "Have function ${FUNCTION}")
  33       FILE(APPEND ${CMAKE_BINARY_DIR}/CMakeError.log
  34         "Determining if the function ${FUNCTION} exists failed with the following output:\n"
  35         "${OUTPUT}\n\n")
  36     ENDIF(${VARIABLE})
  37   ENDIF("${VARIABLE}" MATCHES "^${VARIABLE}$")
  38 ENDMACRO(CHECK_FUNCTION_EXISTS)