CompileFeatures: Don't try_compile for language levels with no features

Previously Compilers always had to run a try_compile to determine what
language level each feature mapped to. Now we can skip the try_compile
when a language level has no features.
This commit is contained in:
Robert Maynard 2019-03-06 12:24:48 -05:00
parent 616282a5ce
commit 85415afbdc

View File

@ -71,10 +71,20 @@ endmacro()
macro(_record_compiler_features_c std)
list(APPEND CMAKE_C${std}_COMPILE_FEATURES c_std_${std})
_record_compiler_features(C "${CMAKE_C${std}_STANDARD_COMPILE_OPTION}" CMAKE_C${std}_COMPILE_FEATURES)
get_property(lang_level_has_features GLOBAL PROPERTY CMAKE_C${std}_KNOWN_FEATURES)
if(lang_level_has_features)
_record_compiler_features(C "${CMAKE_C${std}_STANDARD_COMPILE_OPTION}" CMAKE_C${std}_COMPILE_FEATURES)
endif()
unset(lang_level_has_features)
endmacro()
macro(_record_compiler_features_cxx std)
list(APPEND CMAKE_CXX${std}_COMPILE_FEATURES cxx_std_${std})
_record_compiler_features(CXX "${CMAKE_CXX${std}_STANDARD_COMPILE_OPTION}" CMAKE_CXX${std}_COMPILE_FEATURES)
get_property(lang_level_has_features GLOBAL PROPERTY CMAKE_CXX${std}_KNOWN_FEATURES)
if(lang_level_has_features)
_record_compiler_features(CXX "${CMAKE_CXX${std}_STANDARD_COMPILE_OPTION}" CMAKE_CXX${std}_COMPILE_FEATURES)
endif()
unset(lang_level_has_features)
endmacro()