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Diffstat (limited to 'share/cmake-3.18/Modules/CheckFunctionExists.cmake')
| -rw-r--r-- | share/cmake-3.18/Modules/CheckFunctionExists.cmake | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/share/cmake-3.18/Modules/CheckFunctionExists.cmake b/share/cmake-3.18/Modules/CheckFunctionExists.cmake new file mode 100644 index 0000000..136da89 --- /dev/null +++ b/share/cmake-3.18/Modules/CheckFunctionExists.cmake @@ -0,0 +1,119 @@ +# Distributed under the OSI-approved BSD 3-Clause License. See accompanying +# file Copyright.txt or https://cmake.org/licensing for details. + +#[=======================================================================[.rst: +CheckFunctionExists +------------------- + +Check if a C function can be linked + +.. command:: check_function_exists + + .. code-block:: cmake + + check_function_exists(<function> <variable>) + + Checks that the ``<function>`` is provided by libraries on the system and store + the result in a ``<variable>``, which will be created as an internal + cache variable. + +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`` + a :ref:`;-list <CMake Language Lists>` of macros to define (-DFOO=bar). +``CMAKE_REQUIRED_INCLUDES`` + a :ref:`;-list <CMake Language Lists>` of header search paths to pass to + the compiler. +``CMAKE_REQUIRED_LINK_OPTIONS`` + a :ref:`;-list <CMake Language Lists>` of options to add to the link command. +``CMAKE_REQUIRED_LIBRARIES`` + a :ref:`;-list <CMake Language Lists>` of libraries to add to the link + command. See policy :policy:`CMP0075`. +``CMAKE_REQUIRED_QUIET`` + execute quietly without messages. + +.. note:: + + Prefer using :Module:`CheckSymbolExists` instead of this module, + for the following reasons: + + * ``check_function_exists()`` can't detect functions that are inlined + in headers or specified as a macro. + + * ``check_function_exists()`` can't detect anything in the 32-bit + versions of the Win32 API, because of a mismatch in calling conventions. + + * ``check_function_exists()`` only verifies linking, it does not verify + that the function is declared in system headers. +#]=======================================================================] + +include_guard(GLOBAL) + +macro(CHECK_FUNCTION_EXISTS FUNCTION VARIABLE) + if(NOT DEFINED "${VARIABLE}" OR "x${${VARIABLE}}" STREQUAL "x${VARIABLE}") + set(MACRO_CHECK_FUNCTION_DEFINITIONS + "-DCHECK_FUNCTION_EXISTS=${FUNCTION} ${CMAKE_REQUIRED_FLAGS}") + if(NOT CMAKE_REQUIRED_QUIET) + message(CHECK_START "Looking for ${FUNCTION}") + endif() + if(CMAKE_REQUIRED_LINK_OPTIONS) + set(CHECK_FUNCTION_EXISTS_ADD_LINK_OPTIONS + LINK_OPTIONS ${CMAKE_REQUIRED_LINK_OPTIONS}) + else() + set(CHECK_FUNCTION_EXISTS_ADD_LINK_OPTIONS) + endif() + if(CMAKE_REQUIRED_LIBRARIES) + set(CHECK_FUNCTION_EXISTS_ADD_LIBRARIES + LINK_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES}) + else() + set(CHECK_FUNCTION_EXISTS_ADD_LIBRARIES) + endif() + if(CMAKE_REQUIRED_INCLUDES) + set(CHECK_FUNCTION_EXISTS_ADD_INCLUDES + "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}") + else() + set(CHECK_FUNCTION_EXISTS_ADD_INCLUDES) + endif() + + if(CMAKE_C_COMPILER_LOADED) + set(_cfe_source ${CMAKE_ROOT}/Modules/CheckFunctionExists.c) + elseif(CMAKE_CXX_COMPILER_LOADED) + set(_cfe_source ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckFunctionExists/CheckFunctionExists.cxx) + configure_file(${CMAKE_ROOT}/Modules/CheckFunctionExists.c "${_cfe_source}" COPYONLY) + else() + message(FATAL_ERROR "CHECK_FUNCTION_EXISTS needs either C or CXX language enabled") + endif() + + try_compile(${VARIABLE} + ${CMAKE_BINARY_DIR} + ${_cfe_source} + COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS} + ${CHECK_FUNCTION_EXISTS_ADD_LINK_OPTIONS} + ${CHECK_FUNCTION_EXISTS_ADD_LIBRARIES} + CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS} + "${CHECK_FUNCTION_EXISTS_ADD_INCLUDES}" + OUTPUT_VARIABLE OUTPUT) + unset(_cfe_source) + + if(${VARIABLE}) + set(${VARIABLE} 1 CACHE INTERNAL "Have function ${FUNCTION}") + if(NOT CMAKE_REQUIRED_QUIET) + message(CHECK_PASS "found") + endif() + 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() + if(NOT CMAKE_REQUIRED_QUIET) + message(CHECK_FAIL "not found") + endif() + 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() + endif() +endmacro() |