size_t referenceCount;
#endif
- _Unwind_Exception unwindHeader;
+ // This field is annotated with attribute aligned so that the exception
+ // object following the field is sufficiently aligned and there is no
+ // gap between the field and the exception object. r276215 made a change to
+ // annotate _Unwind_Exception with __attribute__((aligned)), but we cannot
+ // incorporate the fix on Darwin since it is an ABI-breaking change, which
+ // is why we need the attribute on this field.
+ _Unwind_Exception unwindHeader __attribute__((aligned));
};
// http://sourcery.mentor.com/archives/cxx-abi-dev/msg01924.html
void* primaryException;
#endif
- _Unwind_Exception unwindHeader;
+ // See the comment in __cxa_exception as to why this field has attribute
+ // aligned.
+ _Unwind_Exception unwindHeader __attribute__((aligned));
};
struct _LIBCXXABI_HIDDEN __cxa_eh_globals {
--- /dev/null
+//===---------------- exception_object_alignment.sh.cpp -------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: libcxxabi-no-exceptions
+
+// RUN: %build -O1
+// RUN: %run
+
+// This test used to fail on Darwin because field unwindHeader of struct
+// __cxa_exception and the exception object that immediately followed were not
+// 16B aligned. It would segfault in class derived's constructor when a movaps
+// tried to write to a memory operand that was not 16B aligned.
+
+namespace {
+
+struct S {
+ int a;
+ int __attribute__((aligned(16))) b;
+};
+
+class base1 {
+protected:
+ virtual ~base1() throw() {}
+};
+
+class derived: public base1 {
+public:
+ derived() : member() {}
+private:
+ S member;
+};
+
+}
+
+int main() {
+ try {
+ throw derived();
+ }
+ catch(...) {
+ }
+ return 0;
+}