CMake/Modules/Compiler/AppleClang-C-FeatureTests.cmake
Stephen Kelly fb3487a997 Features: Fix C90 feature detection.
This bug caused c_function_prototypes to not be recorded at configure
time when compiling with -std=gnu99 or similar. In the case of feature
recording, that was not a problem, because the logic in
CMakeDetermineCompileFeatures.cmake currently assumes that a feature
present for an earlier standard is present for a later standard.

However, the detection strings are also used in WriteCompilerDetectionHeader,
so the feature macro has been defined to '0' when using a later language
dialect.

Fix that by not checking the existence of the __STDC_VERSION__ macro at
all when detecting C90 features.
2015-02-04 18:38:21 -05:00

12 lines
595 B
CMake

set(_cmake_oldestSupported "((__clang_major__ * 100) + __clang_minor__) >= 400")
set(AppleClang_C11 "${_cmake_oldestSupported} && defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L")
set(_cmake_feature_test_c_static_assert "${AppleClang_C11}")
set(AppleClang_C99 "${_cmake_oldestSupported} && defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L")
set(_cmake_feature_test_c_restrict "${AppleClang_C99}")
set(_cmake_feature_test_c_variadic_macros "${AppleClang_C99}")
set(AppleClang_C90 "${_cmake_oldestSupported}")
set(_cmake_feature_test_c_function_prototypes "${AppleClang_C90}")