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cmake/Modules/CheckSourceCompiles.cmake

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# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#[=======================================================================[.rst:
CheckSourceCompiles
----------------------
.. versionadded:: 3.19
Check if given source compiles and links into an executable.
.. command:: check_source_compiles
.. code-block:: cmake
check_source_compiles(<lang> <code> <resultVar>
[FAIL_REGEX <regex1> [<regex2>...]]
[SRC_EXT <extension>])
Check that the source supplied in ``<code>`` can be compiled as a source
file for the requested language and linked as an executable. The result
will be stored in the internal cache variable specified by ``<resultVar>``,
with a boolean true value for success and boolean false for failure. If
``FAIL_REGEX`` is provided, then failure is determined by checking if
anything in the compiler output matches any of the specified regular
expressions.
By default, the test source file will be given a file extension that matches
the requested language. The ``SRC_EXT`` option can be used to override this
with ``.<extension>`` instead.
The ``<code>`` must contain a valid main program. For example:
.. code-block:: cmake
check_source_compiles(C
"#include <stdlib.h>
#include <stdnoreturn.h>
noreturn void f(){ exit(0); }
int main(void) { f(); return 1; }"
HAVE_NORETURN)
check_source_compiles(Fortran
"program test
error stop
end program"
HAVE_ERROR_STOP)
The check is only performed once, with the result cached in the variable
named by ``<resultVar>``. Every subsequent CMake run will reuse this cached
value rather than performing the check again, even if the ``<code>`` changes.
In order to force the check to be re-evaluated, the variable named by
``<resultVar>`` must be manually removed from the cache.
The compile and link commands can be influenced by setting any of the
following variables prior to calling ``check_source_compiles()``:
.. include:: /module/CMAKE_REQUIRED_FLAGS.txt
.. include:: /module/CMAKE_REQUIRED_DEFINITIONS.txt
.. include:: /module/CMAKE_REQUIRED_INCLUDES.txt
.. include:: /module/CMAKE_REQUIRED_LINK_OPTIONS.txt
.. include:: /module/CMAKE_REQUIRED_LIBRARIES.txt
.. include:: /module/CMAKE_REQUIRED_QUIET.txt
#]=======================================================================]
include_guard(GLOBAL)
include(Internal/CheckSourceCompiles)
function(CHECK_SOURCE_COMPILES _lang _source _var)
cmake_check_source_compiles(${_lang} "${_source}" ${_var} ${ARGN})
endfunction()