Modules/CheckLibraryExists.cmake

   1 # Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
   2 # file Copyright.txt or https://cmake.org/licensing for details.
   3
   4 #[=======================================================================[.rst:
   5 CheckLibraryExists
   6 ------------------
   7
   8 Check if the function exists.
   9
  10 .. command:: CHECK_LIBRARY_EXISTS
  11
  12   .. code-block:: cmake
  13
  14     CHECK_LIBRARY_EXISTS(LIBRARY FUNCTION LOCATION VARIABLE)
  15
  16   ::
  17
  18     LIBRARY  - the name of the library you are looking for
  19     FUNCTION - the name of the function
  20     LOCATION - location where the library should be found
  21     VARIABLE - variable to store the result
  22                Will be created as an internal cache variable.
  23
  24
  25
  26 The following variables may be set before calling this macro to modify
  27 the way the check is run:
  28
  29 ``CMAKE_REQUIRED_FLAGS``
  30   string of compile command line flags.
  31 ``CMAKE_REQUIRED_DEFINITIONS``
  32   list of macros to define (-DFOO=bar).
  33 ``CMAKE_REQUIRED_LINK_OPTIONS``
  34   .. versionadded:: 3.14
  35     list of options to pass to link command.
  36 ``CMAKE_REQUIRED_LIBRARIES``
  37   list of libraries to link.
  38 ``CMAKE_REQUIRED_QUIET``
  39   .. versionadded:: 3.1
  40     execute quietly without messages.
  41 #]=======================================================================]
  42
  43 include_guard(GLOBAL)
  44
  45 macro(CHECK_LIBRARY_EXISTS LIBRARY FUNCTION LOCATION VARIABLE)
  46   if(NOT DEFINED "${VARIABLE}")
  47     set(MACRO_CHECK_LIBRARY_EXISTS_DEFINITION
  48       "-DCHECK_FUNCTION_EXISTS=${FUNCTION} ${CMAKE_REQUIRED_FLAGS}")
  49     if(NOT CMAKE_REQUIRED_QUIET)
  50       message(CHECK_START "Looking for ${FUNCTION} in ${LIBRARY}")
  51     endif()
  52     set(CHECK_LIBRARY_EXISTS_LINK_OPTIONS)
  53     if(CMAKE_REQUIRED_LINK_OPTIONS)
  54       set(CHECK_LIBRARY_EXISTS_LINK_OPTIONS
  55         LINK_OPTIONS ${CMAKE_REQUIRED_LINK_OPTIONS})
  56     endif()
  57     set(CHECK_LIBRARY_EXISTS_LIBRARIES ${LIBRARY})
  58     if(CMAKE_REQUIRED_LIBRARIES)
  59       set(CHECK_LIBRARY_EXISTS_LIBRARIES
  60         ${CHECK_LIBRARY_EXISTS_LIBRARIES} ${CMAKE_REQUIRED_LIBRARIES})
  61     endif()
  62
  63     if(CMAKE_C_COMPILER_LOADED)
  64       set(_cle_source CheckFunctionExists.c)
  65     elseif(CMAKE_CXX_COMPILER_LOADED)
  66       set(_cle_source CheckFunctionExists.cxx)
  67     else()
  68       message(FATAL_ERROR "CHECK_FUNCTION_EXISTS needs either C or CXX language enabled")
  69     endif()
  70
  71     try_compile(${VARIABLE}
  72       SOURCE_FROM_FILE "${_cle_source}" "${CMAKE_ROOT}/Modules/CheckFunctionExists.c"
  73       COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
  74       ${CHECK_LIBRARY_EXISTS_LINK_OPTIONS}
  75       LINK_LIBRARIES ${CHECK_LIBRARY_EXISTS_LIBRARIES}
  76       CMAKE_FLAGS
  77       -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_LIBRARY_EXISTS_DEFINITION}
  78       -DLINK_DIRECTORIES:STRING=${LOCATION}
  79       OUTPUT_VARIABLE OUTPUT)
  80     unset(_cle_source)
  81
  82     if(${VARIABLE})
  83       if(NOT CMAKE_REQUIRED_QUIET)
  84         message(CHECK_PASS "found")
  85       endif()
  86       set(${VARIABLE} 1 CACHE INTERNAL "Have library ${LIBRARY}")
  87       file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
  88         "Determining if the function ${FUNCTION} exists in the ${LIBRARY} "
  89         "passed with the following output:\n"
  90         "${OUTPUT}\n\n")
  91     else()
  92       if(NOT CMAKE_REQUIRED_QUIET)
  93         message(CHECK_FAIL "not found")
  94       endif()
  95       set(${VARIABLE} "" CACHE INTERNAL "Have library ${LIBRARY}")
  96       file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
  97         "Determining if the function ${FUNCTION} exists in the ${LIBRARY} "
  98         "failed with the following output:\n"
  99         "${OUTPUT}\n\n")
 100     endif()
 101   endif()
 102 endmacro()