120 lines
4.4 KiB
CMake
120 lines
4.4 KiB
CMake
|
# 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()
|