Implement proper module linking.

src/parser.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 1228 matching lines @@
             !scanner().literal_contains_escapes()) {
           return ParseModuleDeclaration(NULL, ok);
         }
       }
       return stmt;
     }
   }
 }
 
 
-Block* Parser::ParseModuleDeclaration(ZoneStringList* names, bool* ok) {
+Statement* Parser::ParseModuleDeclaration(ZoneStringList* names, bool* ok) {
   // ModuleDeclaration:
   //    'module' Identifier Module
 
-  // Create new block with one expected declaration.
-  Block* block = factory()->NewBlock(NULL, 1, true);
   Handle<String> name = ParseIdentifier(CHECK_OK);
 
 #ifdef DEBUG
   if (FLAG_print_interface_details)
     PrintF("# Module %s...\n", name->ToAsciiArray());
 #endif
 
   Module* module = ParseModule(CHECK_OK);
   VariableProxy* proxy = NewUnresolved(name, LET, module->interface());
   Declaration* declaration =
       factory()->NewModuleDeclaration(proxy, module, top_scope_);
   Declare(declaration, true, CHECK_OK);
 
 #ifdef DEBUG
   if (FLAG_print_interface_details)
     PrintF("# Module %s.\n", name->ToAsciiArray());
 
   if (FLAG_print_interfaces) {
     PrintF("module %s : ", name->ToAsciiArray());
     module->interface()->Print();
   }
 #endif
 
-  // TODO(rossberg): Add initialization statement to block.
-
   if (names) names->Add(name, zone());
-  return block;
+  if (module->body() == NULL)
+    return factory()->NewEmptyStatement();
+  else
+    return module->body();
 }
 
 
 Module* Parser::ParseModule(bool* ok) {
   // Module:
   //    '{' ModuleElement '}'
   //    '=' ModulePath ';'
   //    'at' String ';'
 
   switch (peek()) {
@@ skipping 45 matching lines @@
         body->AddStatement(stat, zone());
         block_finder.Update(stat);
       }
     }
   }
 
   Expect(Token::RBRACE, CHECK_OK);
   scope->set_end_position(scanner().location().end_pos);
   body->set_scope(scope);
 
-  // Instance objects have to be created ahead of time (before code generation
-  // linking them) because of potentially cyclic references between them.
-  // We create them here, to avoid another pass over the AST.
+  // Check that all exports are bound.
   Interface* interface = scope->interface();
+  for (Interface::Iterator it = interface->iterator();
+       !it.done(); it.Advance()) {
+    if (scope->LocalLookup(it.name()) == NULL) {
+      Handle<String> name(it.name());
+      ReportMessage("module_export_undefined",
+                    Vector<Handle<String> >(&name, 1));
+      *ok = false;
+      return NULL;
+    }
+  }
+
   interface->MakeModule(ok);
-  ASSERT(ok);
-  interface->MakeSingleton(Isolate::Current()->factory()->NewJSModule(), ok);
-  ASSERT(ok);
+  ASSERT(*ok);
   interface->Freeze(ok);
-  ASSERT(ok);
+  ASSERT(*ok);
   return factory()->NewModuleLiteral(body, interface);
 }
 
 
 Module* Parser::ParseModulePath(bool* ok) {
   // ModulePath:
   //    Identifier
   //    ModulePath '.' Identifier
 
   Module* result = ParseModuleVariable(CHECK_OK);
@@ skipping 50 matching lines @@
   Handle<String> symbol = GetSymbol(CHECK_OK);
 
   // TODO(ES6): Request JS resource from environment...
 
 #ifdef DEBUG
   if (FLAG_print_interface_details) PrintF("# Url ");
 #endif
 
   Module* result = factory()->NewModuleUrl(symbol);
   Interface* interface = result->interface();
-  interface->MakeSingleton(Isolate::Current()->factory()->NewJSModule(), ok);
-  ASSERT(ok);
   interface->Freeze(ok);
-  ASSERT(ok);
+  ASSERT(*ok);
+  // Create dummy scope to avoid errors as long as the feature isn't finished.
+  Scope* scope = NewScope(top_scope_, MODULE_SCOPE);
+  interface->Unify(scope->interface(), zone(), ok);
+  ASSERT(*ok);
   return result;
 }
 
 
 Module* Parser::ParseModuleSpecifier(bool* ok) {
   // ModuleSpecifier:
   //    String
   //    ModulePath
 
   if (peek() == Token::STRING) {
@@ skipping 295 matching lines @@
 }
 
 
 void Parser::Declare(Declaration* declaration, bool resolve, bool* ok) {
   VariableProxy* proxy = declaration->proxy();
   Handle<String> name = proxy->name();
   VariableMode mode = declaration->mode();
   Scope* declaration_scope = DeclarationScope(mode);
   Variable* var = NULL;
 
-  // If a function scope exists, then we can statically declare this
+  // If a suitable scope exists, then we can statically declare this
   // variable and also set its mode. In any case, a Declaration node
   // will be added to the scope so that the declaration can be added
   // to the corresponding activation frame at runtime if necessary.
   // For instance declarations inside an eval scope need to be added
   // to the calling function context.
   // Similarly, strict mode eval scope does not leak variable declarations to
   // the caller's scope so we declare all locals, too.
-  // Also for block scoped let/const bindings the variable can be
-  // statically declared.
   if (declaration_scope->is_function_scope() ||
       declaration_scope->is_strict_or_extended_eval_scope() ||
       declaration_scope->is_block_scope() ||
       declaration_scope->is_module_scope() ||
       declaration->AsModuleDeclaration() != NULL) {
-    // Declare the variable in the function scope.
+    // Declare the variable in the declaration scope.
     var = declaration_scope->LocalLookup(name);
     if (var == NULL) {
       // Declare the name.
       var = declaration_scope->DeclareLocal(
           name, mode, declaration->initialization(), proxy->interface());
     } else {
       // The name was declared in this scope before; check for conflicting
       // re-declarations. We have a conflict if either of the declarations is
       // not a var. There is similar code in runtime.cc in the Declare
       // functions. The function CheckNonConflictingScope checks for conflicting
@@ skipping 4292 matching lines @@
       ASSERT(info->isolate()->has_pending_exception());
     } else {
       result = parser.ParseProgram();
     }
   }
   info->SetFunction(result);
   return (result != NULL);
 }
 
 } }  // namespace v8::internal