From 088977679e11584f89a3a5d35939460311955591 Mon Sep 17 00:00:00 2001
From: David Chisnall <theraven@FreeBSD.org>
Date: Sat, 30 Mar 2019 20:01:19 +0000
Subject: [PATCH] DWARF EH cleanups.

Update the C++ ABI for the C++11 ABI and fix the missing ARM-specific
bits.  Work around a bug in ARM.
---
 eh_personality.c | 13 ++++++++-----
 objcxx_eh.cc     | 10 ++++++++++
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/eh_personality.c b/eh_personality.c
index 7f2f1f13..c6e992b4 100644
--- a/eh_personality.c
+++ b/eh_personality.c
@@ -89,7 +89,7 @@ static void saveLandingPad(struct _Unwind_Context *context,
                            int selector,
                            dw_eh_ptr_t landingPad)
 {
-#ifdef __arm__
+#ifdef __arm__ && !defined(__ARM_DWARF_EH__)
 	// On ARM, we store the saved exception in the generic part of the structure
 	ucb->barrier_cache.sp = _Unwind_GetGR(context, 13);
 	ucb->barrier_cache.bitpattern[1] = (uint32_t)selector;
@@ -116,7 +116,7 @@ static int loadLandingPad(struct _Unwind_Context *context,
                           unsigned long *selector,
                           dw_eh_ptr_t *landingPad)
 {
-#ifdef __arm__
+#ifdef __arm__ && !defined(__ARM_DWARF_EH__)
 	*selector = ucb->barrier_cache.bitpattern[1];
 	*landingPad = (dw_eh_ptr_t)ucb->barrier_cache.bitpattern[3];
 	return 1;
@@ -134,7 +134,7 @@ static int loadLandingPad(struct _Unwind_Context *context,
 static inline _Unwind_Reason_Code continueUnwinding(struct _Unwind_Exception *ex,
                                                     struct _Unwind_Context *context)
 {
-#ifdef __arm__
+#ifdef __arm__ && !defined(__ARM_DWARF_EH__)
 	if (__gnu_unwind_frame(ex, context) != _URC_OK) { return _URC_FAILURE; }
 #endif
 	return _URC_CONTINUE_UNWIND;
@@ -418,14 +418,17 @@ static inline _Unwind_Reason_Code internal_objc_personality(int version,
 		handler_type handler = check_action_record(context, foreignException,
 				&lsda, action.action_record, thrown_class, &selector);
 		DEBUG_LOG("handler! %d %d\n", (int)handler,  (int)selector);
+		// On ARM, we occasionally get called to install a handler without
+		// phase 1 running (no idea why, I suspect a bug in the generic
+		// unwinder), so skip this check.
+#ifdef __arm__ && !defined(__ARM_DWARF_EH__)
 		// If this is not a cleanup, ignore it and keep unwinding.
-		//if (check_action_record(context, foreignException, &lsda,
-				//action.action_record, thrown_class, &selector) != handler_cleanup)
 		if ((handler != handler_cleanup) && !objcxxException)
 		{
 			DEBUG_LOG("Ignoring handler! %d\n",handler);
 			return continueUnwinding(exceptionObject, context);
 		}
+#endif
 		DEBUG_LOG("Installing cleanup...\n");
 		// If there is a cleanup, we need to return the exception structure
 		// (not the object) to the calling frame.  The exception object
diff --git a/objcxx_eh.cc b/objcxx_eh.cc
index edb48f3b..11c0d513 100644
--- a/objcxx_eh.cc
+++ b/objcxx_eh.cc
@@ -76,17 +76,27 @@ static BOOL isKindOfClass(Class thrown, Class type)
  */
 struct __cxa_exception
 {
+#if __LP64__
+	uintptr_t referenceCount;
+#endif
 	std::type_info *exceptionType;
 	void (*exceptionDestructor) (void *);
 	unexpected_handler unexpectedHandler;
 	terminate_handler terminateHandler;
 	__cxa_exception *nextException;
 	int handlerCount;
+#if defined(__arm__) && !defined(__ARM_DWARF_EH__)
+	_Unwind_Exception *nextCleanup;
+	int cleanupCount;
+#endif
 	int handlerSwitchValue;
 	const char *actionRecord;
 	const char *languageSpecificData;
 	void *catchTemp;
 	void *adjustedPtr;
+#if !__LP64__
+	uintptr_t referenceCount;
+#endif
 	_Unwind_Exception unwindHeader;
 };