[libcxx] Update the way the -std= flag is chosen by CMake and LibcxxTestFormat

Summary:
This patch does two things:
CMake Update:
  - Add compiler flag checks for -std=c++11 and -std=c++1y and remove check for -std=c++0x.
  - Add configuration option LIBCXX_ENABLE_CXX1Y to prevent/allow -std=c++1y from being chosen as the std version. LIBCXX_ENABLE_CXX1Y is set to OFF by default.
  - if LIBCXX_ENABLE_CXX1Y is enabled then set LIBCXX_STD_VERSION to c++1y and fail if the compiler does not support -std=c++1y
  - If c++1y is not enabled then use c++11 and fail if the compiler does not support c++11.

Lit Update:
  - Update lit.site.cfg.in to capture LIBCXX_STD_VERSION information as config.std.
  - Remove mentions of has_cxx0X configuration option.
  - Check for `--param std=X' passed to lit on the command line.
  - Choose the std for the tests either from command line parameter or (if it doesn't exist) the lit.site.cfg.



Reviewers: mclow.lists, danalbert

Reviewed By: danalbert

Subscribers: emaste, rnk, ajwong, danalbert, cfe-commits

Differential Revision: http://reviews.llvm.org/D4329

llvm-svn: 215802

1 files changed, 2 insertions, 1 deletions

diff --git a/libcxx/cmake/config-ix.cmake b/libcxx/cmake/config-ix.cmake
index e8adafd6587..6aa4fa2da75 100644
--- a/libcxx/cmake/config-ix.cmake
+++ b/libcxx/cmake/config-ix.cmake
@@ -2,7 +2,8 @@ include(CheckLibraryExists)
 include(CheckCXXCompilerFlag)
 
 # Check compiler flags
-check_cxx_compiler_flag(-std=c++0x            LIBCXX_HAS_STDCXX0X_FLAG)
+check_cxx_compiler_flag(-std=c++11            LIBCXX_HAS_STDCXX11_FLAG)
+check_cxx_compiler_flag(-std=c++1y            LIBCXX_HAS_STDCXX1Y_FLAG)
 check_cxx_compiler_flag(-fPIC                 LIBCXX_HAS_FPIC_FLAG)
 check_cxx_compiler_flag(-nodefaultlibs        LIBCXX_HAS_NODEFAULTLIBS_FLAG)
 check_cxx_compiler_flag(-nostdinc++           LIBCXX_HAS_NOSTDINCXX_FLAG)