Fix DebugEvaluate for generators.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index b4c34ef76922cf8b997b6ecd72f34c88d85e3587..95e3c08ddc47118dcdaf02f57d84a83f843c66e6 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -11417,24 +11417,29 @@ static Handle<JSObject> MaterializeStackLocalsWithFrameInspector(
   Handle<SharedFunctionInfo> shared(function->shared());
   Handle<ScopeInfo> scope_info(shared->scope_info());
 
-  // First fill all parameters.
-  for (int i = 0; i < scope_info->ParameterCount(); ++i) {
-    Handle<String> name(scope_info->ParameterName(i));
-    VariableMode mode;
-    InitializationFlag init_flag;
-    // Do not materialize the parameter if it is shadowed by a context local.
-    if (scope_info->ContextSlotIndex(*name, &mode, &init_flag) != -1) continue;
-
-    Handle<Object> value(i < frame_inspector->GetParametersCount()
-                             ? frame_inspector->GetParameter(i)
-                             : isolate->heap()->undefined_value(),
-                         isolate);
-    ASSERT(!value->IsTheHole());
+  // First fill all parameters.  Parameters in generators are context-allocated.
+  if (!shared->is_generator()) {
+    for (int i = 0; i < scope_info->ParameterCount(); ++i) {
+      Handle<String> name(scope_info->ParameterName(i));
+      VariableMode mode;
+      InitializationFlag init_flag;
+      // Do not materialize the parameter if it is shadowed by a context local.
+      if (scope_info->ContextSlotIndex(*name, &mode, &init_flag) != -1) {

[Michael Starzinger, 2014/03/24 10:24:28]

I am little bit confused here. For generators we should already context-allocate
all parameter slots, which in turn means this check should hit for all of them.
So I don't see how the assert below would ever hit unless the scoping
information is off.

+        continue;
+      }
 
-    RETURN_IF_EMPTY_HANDLE_VALUE(
-        isolate,
-        Runtime::SetObjectProperty(isolate, target, name, value, NONE, SLOPPY),
-        Handle<JSObject>());
+      Handle<Object> value(i < frame_inspector->GetParametersCount()
+                               ? frame_inspector->GetParameter(i)
+                               : isolate->heap()->undefined_value(),
+                           isolate);
+      ASSERT(!value->IsTheHole());
+
+      RETURN_IF_EMPTY_HANDLE_VALUE(
+          isolate,
+          Runtime::SetObjectProperty(
+              isolate, target, name, value, NONE, SLOPPY),
+          Handle<JSObject>());
+    }
   }
 
   // Second fill all stack locals.
@@ -11468,13 +11473,15 @@ static void UpdateStackLocalsFromMaterializedObject(Isolate* isolate,
   Handle<SharedFunctionInfo> shared(function->shared());
   Handle<ScopeInfo> scope_info(shared->scope_info());
 
-  // Parameters.
-  for (int i = 0; i < scope_info->ParameterCount(); ++i) {
-    ASSERT(!frame->GetParameter(i)->IsTheHole());
-    HandleScope scope(isolate);
-    Handle<Object> value = GetProperty(
-        isolate, target, Handle<String>(scope_info->ParameterName(i)));
-    frame->SetParameterValue(i, *value);
+  // Parameters. Parameters in generators are context-allocated.
+  if (!shared->is_generator()) {
+    for (int i = 0; i < scope_info->ParameterCount(); ++i) {
+      ASSERT(!frame->GetParameter(i)->IsTheHole());

[Michael Starzinger, 2014/03/24 10:24:28]

Likewise, instead of baking in arbitrary special handling of generators here, I
would argue that we should instead use the provided scoping information and just
skip shadowed parameters in this loop.

+      HandleScope scope(isolate);
+      Handle<Object> value = GetProperty(
+          isolate, target, Handle<String>(scope_info->ParameterName(i)));
+      frame->SetParameterValue(i, *value);
+    }
   }
 
   // Stack locals.