[PATCH] D36599: When built with ASan, __cxa_throw calls __asan_handle_no_return

Roland McGrath via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Thu Aug 10 17:12:35 PDT 2017

mcgrathr created this revision.

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.




Index: src/cxa_exception.cpp
--- src/cxa_exception.cpp
+++ 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>
 // +---------------------------+-----------------------------+---------------+
 // | __cxa_exception           | _Unwind_Exception CLNGC++\0 | thrown object |
 // +---------------------------+-----------------------------+---------------+
@@ -217,6 +221,12 @@
     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();

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