# - 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
#
# 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 2002-2009 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 distributed this file outside of CMake, substitute the full
# License text for the above reference.)
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}")
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)