[Mac] In base::mac::CxxPersonalityRoutine, delegate back to __gxx_personality_v0.

base/mac/call_with_eh_frame.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/mac/call_with_eh_frame.h"
 
 #include <stdint.h>
 #include <unwind.h>
 
 #include "build/build_config.h"
 
 namespace base {
 namespace mac {
 
-_Unwind_Reason_Code CxxPersonalityRoutine(
-    int version,
-    _Unwind_Action actions,
-    uint64_t exceptionClass,
-    struct _Unwind_Exception* exceptionObject,
-    struct _Unwind_Context* context) {
-  // Tell libunwind that this is the end of the stack. When it encounters the
-  // CallWithEHFrame, it will stop searching for an exception handler. The
-  // result is that no exception handler has been found higher on the stack,
-  // and any that are lower on the stack (e.g. in CFRunLoopRunSpecific), will
-  // now be skipped. Since this is reporting the end of the stack, and no
-  // exception handler will have been found, std::terminate() will be called.
-  return _URC_END_OF_STACK;
-}
-
 #if defined(OS_IOS)
 // No iOS assembly implementation exists, so just call the block directly.
 void CallWithEHFrame(void (^block)(void)) {
   block();
 }
-#endif
+#else  // OS_MACOSX
+extern "C" _Unwind_Reason_Code __gxx_personality_v0(int,
+                                                    _Unwind_Action,
+                                                    uint64_t,
+                                                    struct _Unwind_Exception*,
+                                                    struct _Unwind_Context*);
+
+_Unwind_Reason_Code CxxPersonalityRoutine(
+    int version,
+    _Unwind_Action actions,
+    uint64_t exception_class,
+    struct _Unwind_Exception* exception_object,
+    struct _Unwind_Context* context) {
+  // Unwinding is a two-phase process: phase one searches for an exception
+  // handler, and phase two performs cleanup. For phase one, this custom
+  // personality will terminate the search. For phase two, this should delegate
+  // back to the standard personality routine.
+
+  if ((actions & _UA_SEARCH_PHASE) != 0) {
+    // Tell libunwind that this is the end of the stack. When it encounters the
+    // CallWithEHFrame, it will stop searching for an exception handler. The
+    // result is that no exception handler has been found higher on the stack,
+    // and any that are lower on the stack (e.g. in CFRunLoopRunSpecific), will
+    // now be skipped. Since this is reporting the end of the stack, and no
+    // exception handler will have been found, std::terminate() will be called.
+    return _URC_END_OF_STACK;
+  }
+
+  return __gxx_personality_v0(version, actions, exception_class,
+                              exception_object, context);
+}
+#endif  // defined(OS_IOS)
 
 }  // namespace mac
 }  // namespace base