[libcxxabi] Introduce a -fno-exceptions libc++abi libary variant

Currently there is only support for a -fno-exceptions libc++ build. This is
problematic for functions such as std::terminate() which are defined in
libc++abi and using any of those functions throws away most of the benefits
of using -fno-exceptions (code-size). This patch introduces a -fno-exceptions
libc++abi build to address this issue.

This new variant of libc++abi cannot be linked against any with-exceptions
code as some symbols necessary for handling exceptions are missing in this
library.

Differential revision: http://reviews.llvm.org/D20677

Reviewers: EricWF, mclow.lists, bcraig
llvm-svn: 271267

1 files changed, 4 insertions, 4 deletions

diff --git a/libcxxabi/src/cxa_handlers.cpp b/libcxxabi/src/cxa_handlers.cpp
index c231b5a3ecb..3f781313df8 100644
--- a/libcxxabi/src/cxa_handlers.cpp
+++ b/libcxxabi/src/cxa_handlers.cpp
@@ -61,21 +61,21 @@ __attribute__((visibility("hidden"), noreturn))
 void
 __terminate(terminate_handler func) _NOEXCEPT
 {
-#if __has_feature(cxx_exceptions)
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
     try
     {
-#endif  // __has_feature(cxx_exceptions)
+#endif  // _LIBCXXABI_NO_EXCEPTIONS
         func();
         // handler should not return
         abort_message("terminate_handler unexpectedly returned");
-#if __has_feature(cxx_exceptions)
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
     }
     catch (...)
     {
         // handler should not throw exception
         abort_message("terminate_handler unexpectedly threw an exception");
     }
-#endif  // #if __has_feature(cxx_exceptions)
+#endif  // _LIBCXXABI_NO_EXCEPTIONS
 }
 
 __attribute__((noreturn))