[libcxxabi] When built with ASan, __cxa_throw calls __asan_handle_no_return

The ASan runtime on many systems intercepts cxa_throw just so it
can call asan_handle_no_return first. Some newer systems such as
Fuchsia don't use interceptors on standard library functions at all,
but instead use sanitizer-instrumented versions of the standard
libraries. When libc++abi is built with ASan, cxa_throw can just
call asan_handle_no_return itself so no interceptor is required.

This is a re-land of r311045, which has become safe after r311869
changed compiler-rt to declare __asan_handle_no_return.

Patch by Roland McGrath

Differential Revision: https://reviews.llvm.org/D37229

llvm-svn: 312606

1 files changed, 10 insertions, 0 deletions

diff --git a/libcxxabi/src/cxa_exception.cpp b/libcxxabi/src/cxa_exception.cpp
index 0794444bcc5..204ea2ded00 100644
--- a/libcxxabi/src/cxa_exception.cpp
+++ b/libcxxabi/src/cxa_exception.cpp
@@ -19,6 +19,10 @@
 #include "cxa_handlers.hpp"
 #include "fallback_malloc.h"
 
+#if __has_feature(address_sanitizer)
+#include <sanitizer/asan_interface.h>
+#endif
+
 // +---------------------------+-----------------------------+---------------+
 // | __cxa_exception           | _Unwind_Exception CLNGC++\0 | thrown object |
 // +---------------------------+-----------------------------+---------------+
@@ -217,6 +221,12 @@ __cxa_throw(void *thrown_object, std::type_info *tinfo, void (*dest)(void *)) {
     globals->uncaughtExceptions += 1;   // Not atomically, since globals are thread-local
 
     exception_header->unwindHeader.exception_cleanup = exception_cleanup_func;
+
+#if __has_feature(address_sanitizer)
+    // Inform the ASan runtime that now might be a good time to clean stuff up.
+    __asan_handle_no_return();
+#endif
+
 #ifdef __USING_SJLJ_EXCEPTIONS__
     _Unwind_SjLj_RaiseException(&exception_header->unwindHeader);
 #else