[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, 12 insertions, 0 deletions

diff --git a/libcxxabi/src/cxa_new_delete.cpp b/libcxxabi/src/cxa_new_delete.cpp
index 25a5454e05e..7a2c864c311 100644
--- a/libcxxabi/src/cxa_new_delete.cpp
+++ b/libcxxabi/src/cxa_new_delete.cpp
@@ -47,7 +47,11 @@ operator new(std::size_t size)
         if (nh)
             nh();
         else
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
             throw std::bad_alloc();
+#else
+            break;
+#endif
     }
     return p;
 }
@@ -74,13 +78,17 @@ operator new(size_t size, const std::nothrow_t&)
 #endif
 {
     void* p = 0;
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
     try
     {
+#endif
         p = ::operator new(size);
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
     }
     catch (...)
     {
     }
+#endif
     return p;
 }
 
@@ -115,13 +123,17 @@ operator new[](size_t size, const std::nothrow_t&)
 #endif
 {
     void* p = 0;
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
     try
     {
+#endif
         p = ::operator new[](size);
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
     }
     catch (...)
     {
     }
+#endif
     return p;
 }