Fix building and testing libc++ with GCC.
The changes in src/exception.cpp and cmake/Modules/HandleLibCXXABI.cmake fix a
bug when building libc++ with GCC. Because GCC does not support __has_include
we need to explicitly tell it that we are building against libc++abi via the
preprocessor definition `LIBCXX_BUILDING_LIBCXXABI`.
The changes in include/ratio are to work around CWG defect
1712 (constexpr variable template declarations). GCC 4.8 and before has not
adopted the resolution to this defect.
The changes in include/exception work around an issue where is_final is used
without it being defined in type_traits.
llvm-svn: 237767
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 1f294fd934c17ec9836cbde8293d3c51974cdb05
diff --git a/src/exception.cpp b/src/exception.cpp
index 07983ce..98b7b44 100644
--- a/src/exception.cpp
+++ b/src/exception.cpp
@@ -29,7 +29,7 @@
#define __terminate_handler __cxxabiapple::__cxa_terminate_handler
#define __unexpected_handler __cxxabiapple::__cxa_unexpected_handler
#endif // _LIBCPPABI_VERSION
-#elif defined(LIBCXXRT) || __has_include(<cxxabi.h>)
+#elif defined(LIBCXXRT) || defined(LIBCXX_BUILDING_LIBCXXABI) || __has_include(<cxxabi.h>)
#include <cxxabi.h>
using namespace __cxxabiv1;
#if defined(LIBCXXRT) || defined(_LIBCPPABI_VERSION)