Features: Fix the default C dialect for Clang and GNU.

Clang 3.4 uses C99 by default, and Clang 3.6 uses C11 by default:

 http://thread.gmane.org/gmane.comp.compilers.clang.devel/39379

GNU 4.9 uses C90 by default, and GNU 5.0 uses C11 by default:

 https://gcc.gnu.org/gcc-5/changes.html

Test that the default compiler settings result in the expected dialect
macros being defined for both C and CXX.  Remove the unused main.c
file from the CompileFeatures unit test.
This commit is contained in:
Stephen Kelly 2014-11-17 23:24:31 +01:00
parent 49e2b689a8
commit a3d0ae1758
6 changed files with 79 additions and 15 deletions

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@ -17,7 +17,11 @@ if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 3.4)
set(CMAKE_C11_EXTENSION_COMPILE_OPTION "-std=gnu11")
endif()
set(CMAKE_C_STANDARD_DEFAULT 90)
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 3.6)
set(CMAKE_C_STANDARD_DEFAULT 11)
elseif(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 3.4)
set(CMAKE_C_STANDARD_DEFAULT 99)
endif()
macro(cmake_record_c_compile_features)
macro(_get_clang_features std_version list)

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@ -12,8 +12,11 @@ if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.7)
set(CMAKE_C11_EXTENSION_COMPILE_OPTION "-std=gnu11")
endif()
# This may change in a future GNU version.
set(CMAKE_C_STANDARD_DEFAULT 90)
if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0)
set(CMAKE_C_STANDARD_DEFAULT 11)
else(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.7)
set(CMAKE_C_STANDARD_DEFAULT 90)
endif()
macro(cmake_record_c_compile_features)
macro(_get_gcc_features std_version list)

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@ -77,7 +77,29 @@ foreach(lang CXX C)
endif()
endforeach()
if (CMAKE_C_COMPILE_FEATURES)
string(FIND "${CMAKE_C_FLAGS}" "-std=" std_flag_idx)
if (std_flag_idx EQUAL -1)
add_executable(default_dialect_C default_dialect.c)
target_compile_definitions(default_dialect_C PRIVATE
DEFAULT_C11=$<EQUAL:${CMAKE_C_STANDARD_DEFAULT},11>
DEFAULT_C99=$<EQUAL:${CMAKE_C_STANDARD_DEFAULT},99>
DEFAULT_C90=$<EQUAL:${CMAKE_C_STANDARD_DEFAULT},90>
)
endif()
endif()
if (CMAKE_CXX_COMPILE_FEATURES)
string(FIND "${CMAKE_CXX_FLAGS}" "-std=" std_flag_idx)
if (std_flag_idx EQUAL -1)
add_executable(default_dialect default_dialect.cpp)
target_compile_definitions(default_dialect PRIVATE
DEFAULT_CXX14=$<EQUAL:${CMAKE_CXX_STANDARD_DEFAULT},14>
DEFAULT_CXX11=$<EQUAL:${CMAKE_CXX_STANDARD_DEFAULT},11>
DEFAULT_CXX98=$<EQUAL:${CMAKE_CXX_STANDARD_DEFAULT},98>
)
endif()
add_executable(CompileFeatures main.cpp)
set_property(TARGET CompileFeatures
PROPERTY COMPILE_FEATURES "cxx_auto_type"

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@ -0,0 +1,22 @@
#if DEFAULT_C11
# if __STDC_VERSION__ != 201112L
# error Unexpected value for __STDC_VERSION__.
# endif
#elif DEFAULT_C99
# if __STDC_VERSION__ != 199901L
# error Unexpected value for __STDC_VERSION__.
# endif
#else
# if !DEFAULT_C90
# error Buildsystem error
# endif
# if defined(__STDC_VERSION__)
# error Unexpected __STDC_VERSION__ definition
# endif
#endif
int main()
{
return 0;
}

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@ -0,0 +1,25 @@
template<long l>
struct Outputter;
#if DEFAULT_CXX14
# if __cplusplus != 201402L
Outputter<__cplusplus> o;
# endif
#elif DEFAULT_CXX11
# if __cplusplus != 201103L
Outputter<__cplusplus> o;
# endif
#else
# if !DEFAULT_CXX98
# error Buildsystem error
# endif
# if __cplusplus != 199711L
Outputter<__cplusplus> o;
# endif
#endif
int main()
{
return 0;
}

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@ -1,12 +0,0 @@
int foo(int * restrict a, int * restrict b)
{
(void)a;
(void)b;
return 0;
}
int main()
{
return 0;
}