- Source code: cmake/modules/PHP/CheckCompilerFlag.cmake
This module checks whether the compiler supports given compile option:
include(PHP/CheckCompilerFlag)CMake's CheckCompilerFlag module and its check_compiler_flag() command, at
the time of writing, do not support certain edge cases for certain compilers.
This module aims to address these issues to make checking compile options easier
and more intuitive, while still providing similar functionality on top of
CMake's CheckCompilerFlag.
Additional functionality of this module:
-
Supports checking the
-Wno-*compile options (options that disable warnings).When checking the
-Wno-*flags, some compilers (GCC, Oracle Developer Studio compiler, and most likely some others) don't issue any diagnostic message when encountering unsupported-Wno-*flag. This modules checks for their opposite compile option instead (-W*). For example, the silent-Wno-*compile flags behavior was introduced since GCC 4.4: https://gcc.gnu.org/gcc-4.4/changes.html
This module provides the following command:
php_check_compiler_flag(<lang> <flags> <result-var>)Check that the given flag(s) specified in <flags> are accepted by the <lang>
compiler without issuing any diagnostic message. The result is stored in an
internal cache entry named <result-var>. The language <lang> can be one of
the supported languages by the CMake's CheckCompilerFlag module. Multiple
flags can be passed as a semicolon-separated list.
Usage example:
# CMakeLists.txt
include(PHP/CheckCompilerFlag)
php_check_compiler_flag(C -Wno-clobbered PHP_HAS_WNO_CLOBBERED)