[debug] do not handle debug interrupt in JSON parse/stringify.

R=jgruber@chromium.org

Bug: chromium:789472
Change-Id: I578c0fb13abaeaedcecf862c4e5aa7680b4067e8
Reviewed-on: https://chromium-review.googlesource.com/795972
Commit-Queue: Yang Guo <yangguo@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49718}

src/json-parser.h

@@ -39,6 +39,7 @@ class JsonParser BASE_EMBEDDED {
   MUST_USE_RESULT static MaybeHandle<Object> Parse(Isolate* isolate,
                                                    Handle<String> source,
                                                    Handle<Object> reviver) {
+    PostponeInterruptsScope no_debug_breaks(isolate, StackGuard::DEBUGBREAK);
     Handle<Object> result;
     ASSIGN_RETURN_ON_EXCEPTION(isolate, result,
                                JsonParser(isolate, source).ParseJson(), Object);

src/json-stringifier.cc

@@ -94,6 +94,7 @@ MaybeHandle<Object> JsonStringifier::Stringify(Handle<Object> object,
   if (!gap->IsUndefined(isolate_) && !InitializeGap(gap)) {
     return MaybeHandle<Object>();
   }
+  PostponeInterruptsScope no_debug_breaks(isolate_, StackGuard::DEBUGBREAK);
   Result result = SerializeObject(object);
   if (result == UNCHANGED) return factory()->undefined_value();
   if (result == SUCCESS) return builder_.Finish();

test/cctest/test-debug.cc

@@ -3951,6 +3951,36 @@ TEST(DebugBreak) {
   CheckDebuggerUnloaded();
 }
 
+TEST(DebugBreakWithoutJS) {
+  i::FLAG_stress_compaction = false;
+#ifdef VERIFY_HEAP
+  i::FLAG_verify_heap = true;
+#endif
+  DebugLocalContext env;
+  v8::Isolate* isolate = env->GetIsolate();
+  v8::Local<v8::Context> context = env.context();
+  v8::HandleScope scope(isolate);
+
+  // Register a debug event listener which sets the break flag and counts.
+  SetDebugEventListener(isolate, DebugEventBreak);
+
+  // Set the debug break flag.
+  v8::debug::DebugBreak(env->GetIsolate());
+
+  v8::Local<v8::String> json = v8_str("[1]");
+  v8::Local<v8::Value> parsed = v8::JSON::Parse(context, json).ToLocalChecked();
+  CHECK(v8::JSON::Stringify(context, parsed)
+            .ToLocalChecked()
+            ->Equals(context, json)
+            .FromJust());
+  CHECK_EQ(0, break_point_hit_count);
+  CompileRun("");
+  CHECK_EQ(1, break_point_hit_count);
+
+  // Get rid of the debug event listener.
+  SetDebugEventListener(isolate, nullptr);
+  CheckDebuggerUnloaded();
+}
 
 // Test to ensure that JavaScript code keeps running while the debug break
 // through the stack limit flag is set but breaks are disabled.