Merged: [debug] Disable debug events if JS execution is disallowed

Revision: 8f22fce

BUG=chromium:662674
LOG=N
NOTRY=true
NOPRESUBMIT=true
NOTREECHECKS=true
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/2490023004 .

Cr-Commit-Position: refs/branch-heads/5.4@{v8#81}
Cr-Branched-From: 5ce2827-refs/heads/5.4.500@{#2}
Cr-Branched-From: ad07b49-refs/heads/master@{#38841}

src/debug/debug.cc

@@ -1701,6 +1701,11 @@ MaybeHandle<Object> Debug::PromiseHasUserDefinedRejectHandler(
 
 
 void Debug::OnException(Handle<Object> exception, Handle<Object> promise) {
+  // We cannot generate debug events when JS execution is disallowed.
+  // TODO(5530): Reenable debug events within DisallowJSScopes once relevant
+  // code (MakeExceptionEvent and ProcessDebugEvent) have been moved to C++.
+  if (!AllowJavascriptExecution::IsAllowed(isolate_)) return;
+
   Isolate::CatchType catch_type = isolate_->PredictExceptionCatcher();
 
   // Don't notify listener of exceptions that are internal to a desugaring.

test/debugger/debug/regress/regress-662674.js

@@ -0,0 +1,14 @@
+// Copyright 2016 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.
+
+// Flags: --stack-size=100
+
+Debug = debug.Debug
+
+function overflow() {
+  return overflow();
+}
+
+Debug.setBreakOnException();
+assertThrows(overflow, RangeError);