harmony_scoping: Implement lexical bindings at top level

src/ic/ic.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 "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/base/bits.h"
@@ skipping 643 matching lines @@
     }
     Handle<Object> result;
     ASSIGN_RETURN_ON_EXCEPTION(
         isolate(), result,
         Runtime::GetElementOrCharAt(isolate(), object, index), Object);
     return result;
   }
 
   bool use_ic = MigrateDeprecated(object) ? false : FLAG_use_ic;
 
+  if (FLAG_harmony_scoping && object->IsGlobalObject() && name->IsString()) {
+    // Look up in global context table.
+    Handle<String> str_name = Handle<String>::cast(name);
+    Handle<GlobalObject> global = Handle<GlobalObject>::cast(object);
+    Handle<GlobalContextTable> global_contexts(
+        global->native_context()->global_context_table());
+
+    GlobalContextTable::LookupResult lookup_result;
+    if (GlobalContextTable::Lookup(global_contexts, str_name, &lookup_result)) {
+      return FixedArray::get(GlobalContextTable::GetContext(
+                                 global_contexts, lookup_result.context_index),
+                             lookup_result.slot_index);
+    }
+  }
+
   // Named lookup in the object.
   LookupIterator it(object, name);
   LookupForRead(&it);
 
   if (it.IsFound() || !IsUndeclaredGlobal(object)) {
     // Update inline cache and stub cache.
     if (use_ic) UpdateCaches(&it);
 
     // Get the property.
     Handle<Object> result;
@@ skipping 682 matching lines @@
   }
 
   it->PrepareTransitionToDataProperty(value, NONE, store_mode);
   return it->IsCacheableTransition();
 }
 
 
 MaybeHandle<Object> StoreIC::Store(Handle<Object> object, Handle<Name> name,
                                    Handle<Object> value,
                                    JSReceiver::StoreFromKeyed store_mode) {
+  if (FLAG_harmony_scoping && object->IsGlobalObject() && name->IsString()) {
+    // Look up in global context table.
+    Handle<String> str_name = Handle<String>::cast(name);
+    Handle<GlobalObject> global = Handle<GlobalObject>::cast(object);
+    Handle<GlobalContextTable> global_contexts(
+        global->native_context()->global_context_table());
+
+    GlobalContextTable::LookupResult lookup_result;
+    if (GlobalContextTable::Lookup(global_contexts, str_name, &lookup_result)) {
+      Handle<Context> global_context = GlobalContextTable::GetContext(
+          global_contexts, lookup_result.context_index);
+      if (lookup_result.mode == CONST) {
+        return TypeError("harmony_const_assign", object, name);
+      }
+      global_context->set(lookup_result.slot_index, *value);
+      return value;
+    }
+  }
+
   // TODO(verwaest): Let SetProperty do the migration, since storing a property
   // might deprecate the current map again, if value does not fit.
   if (MigrateDeprecated(object) || object->IsJSProxy()) {
     Handle<Object> result;
     ASSIGN_RETURN_ON_EXCEPTION(
         isolate(), result,
         Object::SetProperty(object, name, value, strict_mode()), Object);
     return result;
   }
 
@@ skipping 1360 matching lines @@
 static const Address IC_utilities[] = {
 #define ADDR(name) FUNCTION_ADDR(name),
     IC_UTIL_LIST(ADDR) NULL
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) { return IC_utilities[id]; }
 }
 }  // namespace v8::internal