| # Distributed under the OSI-approved BSD 3-Clause License. See accompanying |
| # file Copyright.txt or https://cmake.org/licensing for details. |
| |
| #[=======================================================================[.rst: |
| CheckOBJCCompilerFlag |
| --------------------- |
| |
| .. versionadded:: 3.16 |
| |
| Check whether the Objective-C compiler supports a given flag. |
| |
| .. command:: check_objc_compiler_flag |
| |
| .. code-block:: cmake |
| |
| check_objc_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_objc_source_compiles`` macro from the |
| :module:`CheckOBJCSourceCompiles` 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_OBJC_FLAGS <CMAKE_<LANG>_FLAGS>`, unknown flags |
| in such variables may cause a false negative for this check. |
| #]=======================================================================] |
| |
| include_guard(GLOBAL) |
| include(CheckOBJCSourceCompiles) |
| include(CMakeCheckCompilerFlagCommonPatterns) |
| |
| macro (CHECK_OBJC_COMPILER_FLAG _FLAG _RESULT) |
| set(SAFE_CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS}") |
| set(CMAKE_REQUIRED_DEFINITIONS "${_FLAG}") |
| |
| # Normalize locale during test compilation. |
| set(_CheckOBJCCompilerFlag_LOCALE_VARS LC_ALL LC_MESSAGES LANG) |
| foreach(v ${_CheckOBJCCompilerFlag_LOCALE_VARS}) |
| set(_CheckOBJCCompilerFlag_SAVED_${v} "$ENV{${v}}") |
| set(ENV{${v}} OBJC) |
| endforeach() |
| CHECK_COMPILER_FLAG_COMMON_PATTERNS(_CheckOBJCCompilerFlag_COMMON_PATTERNS) |
| CHECK_OBJC_SOURCE_COMPILES("#ifndef __OBJC__\n# error \"Not an Objective-C compiler\"\n#endif\nint main(void) { return 0; }" ${_RESULT} |
| # Some compilers do not fail with a bad flag |
| FAIL_REGEX "command line option .* is valid for .* but not for Objective-C" # GNU |
| FAIL_REGEX "argument unused during compilation: .*" # Clang |
| ${_CheckOBJCCompilerFlag_COMMON_PATTERNS} |
| ) |
| foreach(v ${_CheckOBJCCompilerFlag_LOCALE_VARS}) |
| set(ENV{${v}} ${_CheckOBJCCompilerFlag_SAVED_${v}}) |
| unset(_CheckOBJCCompilerFlag_SAVED_${v}) |
| endforeach() |
| unset(_CheckOBJCCompilerFlag_LOCALE_VARS) |
| unset(_CheckOBJCCompilerFlag_COMMON_PATTERNS) |
| |
| set (CMAKE_REQUIRED_DEFINITIONS "${SAFE_CMAKE_REQUIRED_DEFINITIONS}") |
| endmacro () |