Don't clear exception pending message if we have externally TryCatch and finally on top of stack.

src/isolate.cc

 // Copyright 2012 the V8 project 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 <stdlib.h>
 
 #include "v8.h"
 
 #include "ast.h"
 #include "bootstrapper.h"
@@ skipping 1126 matching lines @@
 
   // Do not forget to clean catcher_ if currently thrown exception cannot
   // be caught.  If necessary, ReThrow will update the catcher.
   thread_local_top()->catcher_ = can_be_caught_externally ?
       try_catch_handler() : NULL;
 
   set_pending_exception(*exception_handle);
 }
 
 
-bool Isolate::IsExternallyCaught() {
+bool Isolate::HasExternalTryCatch() {
   ASSERT(has_pending_exception());
 
   if ((thread_local_top()->catcher_ == NULL) ||
       (try_catch_handler() != thread_local_top()->catcher_)) {
     // When throwing the exception, we found no v8::TryCatch
     // which should care about this exception.
     return false;

[Yang, 2014/06/02 15:21:16]

Can we simply return an expression?

return (thread_local_top()->catcher_ != NULL) && (try_catch_handler() ==
thread_local_top()->catcher_);

   }
 
-  if (!is_catchable_by_javascript(pending_exception())) {

[vsevik, 2014/06/02 15:31:28]

Looking at this once again I think this check is still needed.

Unfortunately you will probably need to extract another function. :(

-    return true;
-  }
+  return true;
+}
 
+
+bool Isolate::IsFinallyOnTop() {
   // Get the address of the external handler so we can compare the address to
   // determine which one is closer to the top of the stack.
   Address external_handler_address =
       thread_local_top()->try_catch_handler_address();
   ASSERT(external_handler_address != NULL);
 
   // The exception has been externally caught if and only if there is
   // an external handler which is on top of the top-most try-finally
   // handler.
   // There should be no try-catch blocks as they would prohibit us from
   // finding external catcher in the first place (see catcher_ check above).
   //
   // Note, that finally clause would rethrow an exception unless it's
   // aborted by jumps in control flow like return, break, etc. and we'll
   // have another chances to set proper v8::TryCatch.
   StackHandler* handler =
       StackHandler::FromAddress(Isolate::handler(thread_local_top()));
   while (handler != NULL && handler->address() < external_handler_address) {
     ASSERT(!handler->is_catch());
-    if (handler->is_finally()) return false;
+    if (handler->is_finally()) return true;
 
     handler = handler->next();
   }
 
-  return true;
+  return false;
 }
 
 
 void Isolate::ReportPendingMessages() {
   ASSERT(has_pending_exception());
-  PropagatePendingExceptionToExternalTryCatch();
+  bool canClearMessage = PropagatePendingExceptionToExternalTryCatch();

[Yang, 2014/06/02 15:21:16]

please name this 'can_clear_message' instead.

 
   HandleScope scope(this);
   if (thread_local_top_.pending_exception_ ==
           heap()->termination_exception()) {
     // Do nothing: if needed, the exception has been already propagated to
     // v8::TryCatch.
   } else {
     if (thread_local_top_.has_pending_message_) {
       thread_local_top_.has_pending_message_ = false;
       if (!thread_local_top_.pending_message_obj_->IsTheHole()) {
         HandleScope scope(this);
         Handle<Object> message_obj(thread_local_top_.pending_message_obj_,
                                    this);
         if (!thread_local_top_.pending_message_script_->IsTheHole()) {
           Handle<Script> script(
               Script::cast(thread_local_top_.pending_message_script_));
           int start_pos = thread_local_top_.pending_message_start_pos_;
           int end_pos = thread_local_top_.pending_message_end_pos_;
           MessageLocation location(script, start_pos, end_pos);
           MessageHandler::ReportMessage(this, &location, message_obj);
         } else {
           MessageHandler::ReportMessage(this, NULL, message_obj);
         }
       }
     }
   }
-  clear_pending_message();
+  if (canClearMessage)
+    clear_pending_message();

[Yang, 2014/06/02 15:21:16]

no line break here.

 }
 
 
 MessageLocation Isolate::GetMessageLocation() {
   ASSERT(has_pending_exception());
 
   if (thread_local_top_.pending_exception_ != heap()->termination_exception() &&
       thread_local_top_.has_pending_message_ &&
       !thread_local_top_.pending_message_obj_->IsTheHole() &&
       !thread_local_top_.pending_message_obj_->IsTheHole()) {
@@ skipping 486 matching lines @@
   debug_ = NULL;
 }
 
 
 void Isolate::InitializeThreadLocal() {
   thread_local_top_.isolate_ = this;
   thread_local_top_.Initialize();
 }
 
 
-void Isolate::PropagatePendingExceptionToExternalTryCatch() {
+bool Isolate::PropagatePendingExceptionToExternalTryCatch() {
   ASSERT(has_pending_exception());
 
-  bool external_caught = IsExternallyCaught();
-  thread_local_top_.external_caught_exception_ = external_caught;
+  bool has_external_try_catch = HasExternalTryCatch();
+  bool is_finally_on_top  = IsFinallyOnTop();
 
-  if (!external_caught) return;
+  bool should_propagate_now = has_external_try_catch && !is_finally_on_top;
+  thread_local_top_.external_caught_exception_ = should_propagate_now;
+
+  if (!should_propagate_now) return !has_external_try_catch;
 
   if (thread_local_top_.pending_exception_ ==
              heap()->termination_exception()) {
     try_catch_handler()->can_continue_ = false;
     try_catch_handler()->has_terminated_ = true;
     try_catch_handler()->exception_ = heap()->null_value();
   } else {
     v8::TryCatch* handler = try_catch_handler();
     ASSERT(thread_local_top_.pending_message_obj_->IsJSMessageObject() ||
            thread_local_top_.pending_message_obj_->IsTheHole());
     ASSERT(thread_local_top_.pending_message_script_->IsScript() ||
            thread_local_top_.pending_message_script_->IsTheHole());
     handler->can_continue_ = true;
     handler->has_terminated_ = false;
     handler->exception_ = pending_exception();
     // Propagate to the external try-catch only if we got an actual message.
-    if (thread_local_top_.pending_message_obj_->IsTheHole()) return;
+    if (thread_local_top_.pending_message_obj_->IsTheHole()) return true;
 
     handler->message_obj_ = thread_local_top_.pending_message_obj_;
     handler->message_script_ = thread_local_top_.pending_message_script_;
     handler->message_start_pos_ = thread_local_top_.pending_message_start_pos_;
     handler->message_end_pos_ = thread_local_top_.pending_message_end_pos_;
   }
+  return true;
 }
 
 
 void Isolate::InitializeLoggingAndCounters() {
   if (logger_ == NULL) {
     logger_ = new Logger(this);
   }
   if (counters_ == NULL) {
     counters_ = new Counters(this);
   }
@@ skipping 482 matching lines @@
   handle_scope_implementer()->IncrementCallDepth();
   if (run_microtasks) Execution::RunMicrotasks(this);
   for (int i = 0; i < call_completed_callbacks_.length(); i++) {
     call_completed_callbacks_.at(i)();
   }
   handle_scope_implementer()->DecrementCallDepth();
 }
 
 
 } }  // namespace v8::internal