# - Check if a C function can be linked # CHECK_FUNCTION_EXISTS( ) # # Check that the is provided by libraries on the system and # store the result in a . This does not verify that any # system header file declares the function, only that it can be found # at link time (considure using CheckSymbolExists). # # 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 #============================================================================= # Copyright 2002-2011 Kitware, Inc. # # Distributed under the OSI-approved BSD License (the "License"); # see accompanying file Copyright.txt for details. # # This software is distributed WITHOUT ANY WARRANTY; without even the # implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. # See the License for more information. #============================================================================= # (To distribute this file outside of CMake, substitute the full # License text for the above reference.) INCLUDE("${CMAKE_CURRENT_LIST_DIR}/CMakeExpandImportedTargets.cmake") MACRO(CHECK_FUNCTION_EXISTS FUNCTION VARIABLE) IF("${VARIABLE}" MATCHES "^${VARIABLE}$") SET(MACRO_CHECK_FUNCTION_DEFINITIONS "-DCHECK_FUNCTION_EXISTS=${FUNCTION} ${CMAKE_REQUIRED_FLAGS}") MESSAGE(STATUS "Looking for ${FUNCTION}") IF(CMAKE_REQUIRED_LIBRARIES) # this one translates potentially used imported library targets to their files on disk CMAKE_EXPAND_IMPORTED_TARGETS(_ADJUSTED_CMAKE_REQUIRED_LIBRARIES LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} CONFIGURATION "${CMAKE_TRY_COMPILE_CONFIGURATION}") SET(CHECK_FUNCTION_EXISTS_ADD_LIBRARIES "-DLINK_LIBRARIES:STRING=${_ADJUSTED_CMAKE_REQUIRED_LIBRARIES}") ELSE(CMAKE_REQUIRED_LIBRARIES) SET(CHECK_FUNCTION_EXISTS_ADD_LIBRARIES) ENDIF(CMAKE_REQUIRED_LIBRARIES) IF(CMAKE_REQUIRED_INCLUDES) SET(CHECK_FUNCTION_EXISTS_ADD_INCLUDES "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}") ELSE(CMAKE_REQUIRED_INCLUDES) SET(CHECK_FUNCTION_EXISTS_ADD_INCLUDES) ENDIF(CMAKE_REQUIRED_INCLUDES) TRY_COMPILE(${VARIABLE} ${CMAKE_BINARY_DIR} ${CMAKE_ROOT}/Modules/CheckFunctionExists.c COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS} CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS} "${CHECK_FUNCTION_EXISTS_ADD_LIBRARIES}" "${CHECK_FUNCTION_EXISTS_ADD_INCLUDES}" OUTPUT_VARIABLE OUTPUT) IF(${VARIABLE}) SET(${VARIABLE} 1 CACHE INTERNAL "Have function ${FUNCTION}") MESSAGE(STATUS "Looking for ${FUNCTION} - found") FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/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 ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/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)