Imported Upstream version 2.8.9
[platform/upstream/cmake.git] / Modules / CheckFunctionExists.cmake
1 # - Check if a C function can be linked
2 # CHECK_FUNCTION_EXISTS(<function> <variable>)
3 #
4 # Check that the <function> is provided by libraries on the system and
5 # store the result in a <variable>.  This does not verify that any
6 # system header file declares the function, only that it can be found
7 # at link time (considure using CheckSymbolExists).
8 #
9 # The following variables may be set before calling this macro to
10 # modify the way the check is run:
11 #
12 #  CMAKE_REQUIRED_FLAGS = string of compile command line flags
13 #  CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
14 #  CMAKE_REQUIRED_INCLUDES = list of include directories
15 #  CMAKE_REQUIRED_LIBRARIES = list of libraries to link
16
17 #=============================================================================
18 # Copyright 2002-2011 Kitware, Inc.
19 #
20 # Distributed under the OSI-approved BSD License (the "License");
21 # see accompanying file Copyright.txt for details.
22 #
23 # This software is distributed WITHOUT ANY WARRANTY; without even the
24 # implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
25 # See the License for more information.
26 #=============================================================================
27 # (To distribute this file outside of CMake, substitute the full
28 #  License text for the above reference.)
29
30 INCLUDE("${CMAKE_CURRENT_LIST_DIR}/CMakeExpandImportedTargets.cmake")
31
32
33 MACRO(CHECK_FUNCTION_EXISTS FUNCTION VARIABLE)
34   IF("${VARIABLE}" MATCHES "^${VARIABLE}$")
35     SET(MACRO_CHECK_FUNCTION_DEFINITIONS
36       "-DCHECK_FUNCTION_EXISTS=${FUNCTION} ${CMAKE_REQUIRED_FLAGS}")
37     MESSAGE(STATUS "Looking for ${FUNCTION}")
38     IF(CMAKE_REQUIRED_LIBRARIES)
39       # this one translates potentially used imported library targets to their files on disk
40       CMAKE_EXPAND_IMPORTED_TARGETS(_ADJUSTED_CMAKE_REQUIRED_LIBRARIES  LIBRARIES  ${CMAKE_REQUIRED_LIBRARIES} CONFIGURATION "${CMAKE_TRY_COMPILE_CONFIGURATION}")
41       SET(CHECK_FUNCTION_EXISTS_ADD_LIBRARIES
42         "-DLINK_LIBRARIES:STRING=${_ADJUSTED_CMAKE_REQUIRED_LIBRARIES}")
43     ELSE(CMAKE_REQUIRED_LIBRARIES)
44       SET(CHECK_FUNCTION_EXISTS_ADD_LIBRARIES)
45     ENDIF(CMAKE_REQUIRED_LIBRARIES)
46     IF(CMAKE_REQUIRED_INCLUDES)
47       SET(CHECK_FUNCTION_EXISTS_ADD_INCLUDES
48         "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}")
49     ELSE(CMAKE_REQUIRED_INCLUDES)
50       SET(CHECK_FUNCTION_EXISTS_ADD_INCLUDES)
51     ENDIF(CMAKE_REQUIRED_INCLUDES)
52     TRY_COMPILE(${VARIABLE}
53       ${CMAKE_BINARY_DIR}
54       ${CMAKE_ROOT}/Modules/CheckFunctionExists.c
55       COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
56       CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS}
57       "${CHECK_FUNCTION_EXISTS_ADD_LIBRARIES}"
58       "${CHECK_FUNCTION_EXISTS_ADD_INCLUDES}"
59       OUTPUT_VARIABLE OUTPUT)
60     IF(${VARIABLE})
61       SET(${VARIABLE} 1 CACHE INTERNAL "Have function ${FUNCTION}")
62       MESSAGE(STATUS "Looking for ${FUNCTION} - found")
63       FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
64         "Determining if the function ${FUNCTION} exists passed with the following output:\n"
65         "${OUTPUT}\n\n")
66     ELSE(${VARIABLE})
67       MESSAGE(STATUS "Looking for ${FUNCTION} - not found")
68       SET(${VARIABLE} "" CACHE INTERNAL "Have function ${FUNCTION}")
69       FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
70         "Determining if the function ${FUNCTION} exists failed with the following output:\n"
71         "${OUTPUT}\n\n")
72     ENDIF(${VARIABLE})
73   ENDIF("${VARIABLE}" MATCHES "^${VARIABLE}$")
74 ENDMACRO(CHECK_FUNCTION_EXISTS)