CMake/Modules/CheckFunctionExists.cmake

41 lines
1.8 KiB
CMake

# - Check if the function exists.
# CHECK_FUNCTION_EXISTS(FUNCTION VARIABLE)
# - macro which checks if the function exists
# FUNCTION - the name of the function
# VARIABLE - variable to store the result
# If CMAKE_REQUIRED_FLAGS is set then those flags will be passed into the
# compile of the program likewise if CMAKE_REQUIRED_LIBRARIES is set then
# those libraries will be linked against the test program
#
MACRO(CHECK_FUNCTION_EXISTS FUNCTION VARIABLE)
IF("${VARIABLE}" MATCHES "^${VARIABLE}$")
SET(MACRO_CHECK_FUNCTION_DEFINITIONS
"-DCHECK_FUNCTION_EXISTS=${FUNCTION} ${CMAKE_REQUIRED_FLAGS}")
MESSAGE(STATUS "Looking for ${FUNCTION}")
IF(CMAKE_REQUIRED_LIBRARIES)
SET(CHECK_FUNCTION_EXISTS_ADD_LIBRARIES
"-DLINK_LIBRARIES:STRING=${CMAKE_REQUIRED_LIBRARIES}")
ENDIF(CMAKE_REQUIRED_LIBRARIES)
TRY_COMPILE(${VARIABLE}
${CMAKE_BINARY_DIR}
${CMAKE_ROOT}/Modules/CheckFunctionExists.c
CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS}
"${CHECK_FUNCTION_EXISTS_ADD_LIBRARIES}"
OUTPUT_VARIABLE OUTPUT)
IF(${VARIABLE})
SET(${VARIABLE} 1 CACHE INTERNAL "Have function ${FUNCTION}")
MESSAGE(STATUS "Looking for ${FUNCTION} - found")
FILE(APPEND ${CMAKE_BINARY_DIR}/CMakeFiles/CMakeOutput.log
"Determining if the function ${FUNCTION} exists passed with the following output:\n"
"${OUTPUT}\n\n")
ELSE(${VARIABLE})
MESSAGE(STATUS "Looking for ${FUNCTION} - not found")
SET(${VARIABLE} "" CACHE INTERNAL "Have function ${FUNCTION}")
FILE(APPEND ${CMAKE_BINARY_DIR}/CMakeFiles/CMakeError.log
"Determining if the function ${FUNCTION} exists failed with the following output:\n"
"${OUTPUT}\n\n")
ENDIF(${VARIABLE})
ENDIF("${VARIABLE}" MATCHES "^${VARIABLE}$")
ENDMACRO(CHECK_FUNCTION_EXISTS)