mirror of
https://github.com/reactos/CMake.git
synced 2024-11-27 13:30:39 +00:00
cb984c6627
- User lower-case names - Wrap in function instead of macro to avoid set-unset calls - Use IN LISTS for foreach
59 lines
2.1 KiB
CMake
59 lines
2.1 KiB
CMake
# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
|
|
# file Copyright.txt or https://cmake.org/licensing for details.
|
|
|
|
#[=======================================================================[.rst:
|
|
CheckCCompilerFlag
|
|
------------------
|
|
|
|
Check whether the C compiler supports a given flag.
|
|
|
|
.. command:: check_c_compiler_flag
|
|
|
|
.. code-block:: cmake
|
|
|
|
check_c_compiler_flag(<flag> <var>)
|
|
|
|
Check that the ``<flag>`` is accepted by the compiler without
|
|
a diagnostic. Stores the result in an internal cache entry
|
|
named ``<var>``.
|
|
|
|
This command temporarily sets the ``CMAKE_REQUIRED_DEFINITIONS`` variable
|
|
and calls the ``check_c_source_compiles`` macro from the
|
|
:module:`CheckCSourceCompiles` module. See documentation of that
|
|
module for a listing of variables that can otherwise modify the build.
|
|
|
|
A positive result from this check indicates only that the compiler did not
|
|
issue a diagnostic message when given the flag. Whether the flag has any
|
|
effect or even a specific one is beyond the scope of this module.
|
|
|
|
.. note::
|
|
Since the :command:`try_compile` command forwards flags from variables
|
|
like :variable:`CMAKE_C_FLAGS <CMAKE_<LANG>_FLAGS>`, unknown flags
|
|
in such variables may cause a false negative for this check.
|
|
#]=======================================================================]
|
|
|
|
include_guard(GLOBAL)
|
|
include(CheckCSourceCompiles)
|
|
include(CMakeCheckCompilerFlagCommonPatterns)
|
|
|
|
function(check_c_compiler_flag _flag _var)
|
|
set(CMAKE_REQUIRED_DEFINITIONS "${_flag}")
|
|
|
|
# Normalize locale during test compilation.
|
|
set(_locale_vars LC_ALL LC_MESSAGES LANG)
|
|
foreach(v IN LISTS _locale_vars)
|
|
set(_locale_vars_saved_${v} "$ENV{${v}}")
|
|
set(ENV{${v}} C)
|
|
endforeach()
|
|
check_compiler_flag_common_patterns(_common_patterns)
|
|
check_c_source_compiles("int main(void) { return 0; }" ${_var}
|
|
# Some compilers do not fail with a bad flag
|
|
FAIL_REGEX "command line option .* is valid for .* but not for C" # GNU
|
|
${_common_patterns}
|
|
)
|
|
foreach(v IN LISTS _locale_vars)
|
|
set(ENV{${v}} ${_locale_vars_saved_${v}})
|
|
endforeach()
|
|
set(${_var} "${${_var}}" PARENT_SCOPE)
|
|
endfunction()
|