[libcxxabi] r329629 - [CFI] Disable CFI checks for __cxa_decrement_exception_refcount

[Vlad Tsyrklevich via cfe-commits]

Author: vlad.tsyrklevich
Date: Mon Apr  9 15:11:28 2018
New Revision: 329629

URL: http://llvm.org/viewvc/llvm-project?rev=329629&view=rev
Log:
[CFI] Disable CFI checks for __cxa_decrement_exception_refcount

Summary:
exception_header->exceptionDestructor is a void(*)(void*) function
pointer; however, it can point to destructors like std::
exception::~exception that don't match that type signature.

Reviewers: pcc, vitalybuka

Reviewed By: vitalybuka

Subscribers: kcc, christof, cfe-commits

Differential Revision: https://reviews.llvm.org/D45455

Modified:
    libcxxabi/trunk/include/__cxxabi_config.h
    libcxxabi/trunk/src/cxa_exception.cpp

Modified: libcxxabi/trunk/include/__cxxabi_config.h
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/include/__cxxabi_config.h?rev=329629&r1=329628&r2=329629&view=diff
==============================================================================
--- libcxxabi/trunk/include/__cxxabi_config.h (original)
+++ libcxxabi/trunk/include/__cxxabi_config.h Mon Apr  9 15:11:28 2018
@@ -60,4 +60,14 @@
 #define _LIBCXXABI_WEAK __attribute__((__weak__))
 #endif
 
+#if defined(__clang__)
+#define _LIBCXXABI_COMPILER_CLANG
+#endif
+
+#if __has_attribute(__no_sanitize__) && defined(_LIBCXXABI_COMPILER_CLANG)
+#define _LIBCXXABI_NO_CFI __attribute__((__no_sanitize__("cfi")))
+#else
+#define _LIBCXXABI_NO_CFI
+#endif
+
 #endif // ____CXXABI_CONFIG_H

Modified: libcxxabi/trunk/src/cxa_exception.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/cxa_exception.cpp?rev=329629&r1=329628&r2=329629&view=diff
==============================================================================
--- libcxxabi/trunk/src/cxa_exception.cpp (original)
+++ libcxxabi/trunk/src/cxa_exception.cpp Mon Apr  9 15:11:28 2018
@@ -630,8 +630,8 @@ __cxa_increment_exception_refcount(void
 
     Requires:  If thrown_object is not NULL, it is a native exception.
 */
-void
-__cxa_decrement_exception_refcount(void *thrown_object) throw() {
+_LIBCXXABI_NO_CFI
+void __cxa_decrement_exception_refcount(void *thrown_object) throw() {
     if (thrown_object != NULL )
     {
         __cxa_exception* exception_header = cxa_exception_from_thrown_object(thrown_object);