[CMake] Check for C++14 instead of C++11

[JDevlieghere]

Summary

Now that LLVM moved to C++14, I suspect that COMPILER_RT_HAS_STD_CXX11_FLAG should become COMPILER_RT_HAS_STD_CXX14_FLAG.

I ran into this issue when replacing llvm::make_unique with std::make_unique in an X-ray unit test. We are correctly passing -std=c++14, but further down in the invocation it was being overriding because we are passing -std=c++11. Given that this unit test is using LLVM headers, this is bound to break sooner than later, regardless of my change.

[phosek]

LGTM

[jfb]

Thanks for fixing this!

compiler-rt/trunk/CMakeLists.txt

 else()
   append_string_if(COMPILER_RT_HAS_WALL_FLAG -Wall CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 endif()
 if(COMPILER_RT_ENABLE_WERROR)
   append_string_if(COMPILER_RT_HAS_WERROR_FLAG -Werror CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
   append_string_if(COMPILER_RT_HAS_WX_FLAG /WX CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 endif()
 
-append_string_if(COMPILER_RT_HAS_STD_CXX11_FLAG -std=c++11 CMAKE_CXX_FLAGS)
+append_string_if(COMPILER_RT_HAS_STD_CXX14_FLAG -std=c++14 CMAKE_CXX_FLAGS)
 
 # Emulate C99 and C++11's __func__ for MSVC prior to 2013 CTP.
 if(NOT COMPILER_RT_HAS_FUNC_SYMBOL)
   add_definitions(-D__func__=__FUNCTION__)
 endif()
 
 # Provide some common commmandline flags for Sanitizer runtimes.
 if(NOT WIN32)

compiler-rt/trunk/cmake/config-ix.cmake

 check_cxx_compiler_flag(-fomit-frame-pointer COMPILER_RT_HAS_FOMIT_FRAME_POINTER_FLAG)
 check_cxx_compiler_flag(-funwind-tables      COMPILER_RT_HAS_FUNWIND_TABLES_FLAG)
 check_cxx_compiler_flag(-fno-stack-protector COMPILER_RT_HAS_FNO_STACK_PROTECTOR_FLAG)
 check_cxx_compiler_flag(-fno-sanitize=safe-stack COMPILER_RT_HAS_FNO_SANITIZE_SAFE_STACK_FLAG)
 check_cxx_compiler_flag(-fvisibility=hidden  COMPILER_RT_HAS_FVISIBILITY_HIDDEN_FLAG)
 check_cxx_compiler_flag(-frtti               COMPILER_RT_HAS_FRTTI_FLAG)
 check_cxx_compiler_flag(-fno-rtti            COMPILER_RT_HAS_FNO_RTTI_FLAG)
 check_cxx_compiler_flag("-Werror -fno-function-sections" COMPILER_RT_HAS_FNO_FUNCTION_SECTIONS_FLAG)
-check_cxx_compiler_flag(-std=c++11           COMPILER_RT_HAS_STD_CXX11_FLAG)
+check_cxx_compiler_flag(-std=c++14           COMPILER_RT_HAS_STD_CXX14_FLAG)
 check_cxx_compiler_flag(-ftls-model=initial-exec COMPILER_RT_HAS_FTLS_MODEL_INITIAL_EXEC)
 check_cxx_compiler_flag(-fno-lto             COMPILER_RT_HAS_FNO_LTO_FLAG)
 check_cxx_compiler_flag("-Werror -msse3" COMPILER_RT_HAS_MSSE3_FLAG)
 check_cxx_compiler_flag("-Werror -msse4.2"   COMPILER_RT_HAS_MSSE4_2_FLAG)
 check_cxx_compiler_flag(--sysroot=.          COMPILER_RT_HAS_SYSROOT_FLAG)
 check_cxx_compiler_flag("-Werror -mcrc"      COMPILER_RT_HAS_MCRC_FLAG)
 check_cxx_compiler_flag(-fno-partial-inlining COMPILER_RT_HAS_FNO_PARTIAL_INLINING_FLAG)