Simplify implementation of assignment-to-const checks

src/scopes.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 290 matching lines @@
           : FLAG_print_scopes) {
     scope->Print();
   }
 
   if (FLAG_harmony_modules && FLAG_print_interfaces && top->is_global_scope()) {
     PrintF("global : ");
     top->interface()->Print();
   }
 #endif
 
-  if (FLAG_harmony_scoping) {
-    VariableProxy* proxy = scope->CheckAssignmentToConst();
-    if (proxy != NULL) {
-      // Found an assignment to const. Throw a syntax error.
-      MessageLocation location(info->script(),
-                               proxy->position(),
-                               proxy->position());
-      Isolate* isolate = info->isolate();
-      Factory* factory = isolate->factory();
-      Handle<JSArray> array = factory->NewJSArray(0);
-      Handle<Object> result =
-          factory->NewSyntaxError("harmony_const_assign", array);
-      isolate->Throw(*result, &location);
-      return false;
-    }
-  }
-
   info->SetScope(scope);
   return true;
 }
 
 
 void Scope::Initialize() {
   ASSERT(!already_resolved());
 
   // Add this scope as a new inner scope of the outer scope.
   if (outer_scope_ != NULL) {
@@ skipping 246 matching lines @@
         return decl;
       }
       previous = current;
       current = current->outer_scope_;
     } while (!previous->is_declaration_scope());
   }
   return NULL;
 }
 
 
-VariableProxy* Scope::CheckAssignmentToConst() {
-  // Check this scope.
-  if (is_extended_mode()) {
-    for (int i = 0; i < unresolved_.length(); i++) {
-      ASSERT(unresolved_[i]->var() != NULL);
-      if (unresolved_[i]->var()->is_const_mode() &&
-          unresolved_[i]->IsLValue()) {
-        return unresolved_[i];
-      }
-    }
-  }
-
-  // Check inner scopes.
-  for (int i = 0; i < inner_scopes_.length(); i++) {
-    VariableProxy* proxy = inner_scopes_[i]->CheckAssignmentToConst();
-    if (proxy != NULL) return proxy;
-  }
-
-  // No assignments to const found.
-  return NULL;
-}
-
-
 class VarAndOrder {
  public:
   VarAndOrder(Variable* var, int order) : var_(var), order_(order) { }
   Variable* var() const { return var_; }
   int order() const { return order_; }
   static int Compare(const VarAndOrder* a, const VarAndOrder* b) {
     return a->order_ - b->order_;
   }
 
  private:
@@ skipping 468 matching lines @@
       break;
 
     case DYNAMIC_LOOKUP:
       // The variable could not be resolved statically.
       var = NonLocal(proxy->name(), DYNAMIC);
       break;
   }
 
   ASSERT(var != NULL);
 
+  if (FLAG_harmony_scoping && is_extended_mode() &&
+      var->is_const_mode() && proxy->IsLValue()) {
+    // Assignment to const. Throw a syntax error.
+    MessageLocation location(
+        info->script(), proxy->position(), proxy->position());
+    Isolate* isolate = Isolate::Current();
+    Factory* factory = isolate->factory();
+    Handle<JSArray> array = factory->NewJSArray(0);
+    Handle<Object> result =
+        factory->NewSyntaxError("harmony_const_assign", array);
+    isolate->Throw(*result, &location);
+    return false;
+  }
+
   if (FLAG_harmony_modules) {
     bool ok;
 #ifdef DEBUG
     if (FLAG_print_interface_details)
       PrintF("# Resolve %s:\n", var->name()->ToAsciiArray());
 #endif
     proxy->interface()->Unify(var->interface(), zone(), &ok);
     if (!ok) {
 #ifdef DEBUG
       if (FLAG_print_interfaces) {
         PrintF("SCOPES TYPE ERROR\n");
         PrintF("proxy: ");
         proxy->interface()->Print();
         PrintF("var: ");
         var->interface()->Print();
       }
 #endif
 
       // Inconsistent use of module. Throw a syntax error.
       // TODO(rossberg): generate more helpful error message.
-      MessageLocation location(info->script(),
-                               proxy->position(),
-                               proxy->position());
+      MessageLocation location(
+          info->script(), proxy->position(), proxy->position());
       Isolate* isolate = Isolate::Current();
       Factory* factory = isolate->factory();
       Handle<JSArray> array = factory->NewJSArray(1);
       USE(JSObject::SetElement(array, 0, var->name(), NONE, kStrictMode));
       Handle<Object> result =
           factory->NewSyntaxError("module_type_error", array);
       isolate->Throw(*result, &location);
       return false;
     }
   }
@@ skipping 269 matching lines @@
 }
 
 
 int Scope::ContextLocalCount() const {
   if (num_heap_slots() == 0) return 0;
   return num_heap_slots() - Context::MIN_CONTEXT_SLOTS -
       (function_ != NULL && function_->proxy()->var()->IsContextSlot() ? 1 : 0);
 }
 
 } }  // namespace v8::internal