Class syntax parsing

src/parser.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/api.h"
 #include "src/ast.h"
 #include "src/base/platform/platform.h"
 #include "src/bootstrapper.h"
@@ skipping 348 matching lines @@
   AstNode::IdGen saved_ast_node_id_gen_;
 };
 
 
 bool ParserTraits::IsEvalOrArguments(const AstRawString* identifier) const {
   return identifier == parser_->ast_value_factory_->eval_string() ||
          identifier == parser_->ast_value_factory_->arguments_string();
 }
 
 
+bool ParserTraits::IsPrototype(const AstRawString* identifier) const {
+  return identifier == parser_->ast_value_factory_->prototype_string();
+}
+
+
+bool ParserTraits::IsConstructor(const AstRawString* identifier) const {
+  return identifier == parser_->ast_value_factory_->constructor_string();
+}
+
+
 bool ParserTraits::IsThisProperty(Expression* expression) {
   DCHECK(expression != NULL);
   Property* property = expression->AsProperty();
   return property != NULL &&
       property->obj()->AsVariableProxy() != NULL &&
       property->obj()->AsVariableProxy()->is_this();
 }
 
 
 bool ParserTraits::IsIdentifier(Expression* expression) {
@@ skipping 741 matching lines @@
   //    LetDeclaration
   //    ConstDeclaration
   //    ModuleDeclaration
   //    ImportDeclaration
   //    ExportDeclaration
   //    GeneratorDeclaration
 
   switch (peek()) {
     case Token::FUNCTION:
       return ParseFunctionDeclaration(NULL, ok);
+    case Token::CLASS:
+      return ParseClassDeclaration(NULL, ok);
     case Token::IMPORT:
       return ParseImportDeclaration(ok);
     case Token::EXPORT:
       return ParseExportDeclaration(ok);
     case Token::CONST:
       return ParseVariableStatement(kModuleElement, NULL, ok);
     case Token::LET:
       DCHECK(allow_harmony_scoping());
       if (strict_mode() == STRICT) {
         return ParseVariableStatement(kModuleElement, NULL, ok);
@@ skipping 319 matching lines @@
       } else {
         result = ParseModuleDeclaration(&names, CHECK_OK);
       }
       break;
     }
 
     case Token::FUNCTION:
       result = ParseFunctionDeclaration(&names, CHECK_OK);
       break;
 
+    case Token::CLASS:
+      result = ParseClassDeclaration(&names, CHECK_OK);
+      break;
+
     case Token::VAR:
     case Token::LET:
     case Token::CONST:
       result = ParseVariableStatement(kModuleElement, &names, CHECK_OK);
       break;
 
     default:
       *ok = false;
       ReportUnexpectedToken(scanner()->current_token());
       return NULL;
@@ skipping 42 matching lines @@
   // (Ecma 262 5th Edition, clause 14):
   // SourceElement:
   //    Statement
   //    FunctionDeclaration
   //
   // In harmony mode we allow additionally the following productions
   // BlockElement (aka SourceElement):
   //    LetDeclaration
   //    ConstDeclaration
   //    GeneratorDeclaration
+  //    ClassDeclaration
 
   switch (peek()) {
     case Token::FUNCTION:
       return ParseFunctionDeclaration(NULL, ok);
+    case Token::CLASS:
+      return ParseClassDeclaration(NULL, ok);
     case Token::CONST:
       return ParseVariableStatement(kModuleElement, NULL, ok);
     case Token::LET:
       DCHECK(allow_harmony_scoping());
       if (strict_mode() == STRICT) {
         return ParseVariableStatement(kModuleElement, NULL, ok);
       }
       // Fall through.
     default:
       return ParseStatement(labels, ok);
@@ skipping 91 matching lines @@
       // Statement:
       //    GeneratorDeclaration
       if (strict_mode() == STRICT) {
         ReportMessageAt(scanner()->peek_location(), "strict_function");
         *ok = false;
         return NULL;
       }
       return ParseFunctionDeclaration(NULL, ok);
     }
 
+    case Token::CLASS:
+      return ParseClassDeclaration(NULL, ok);
+
     case Token::DEBUGGER:
       return ParseDebuggerStatement(ok);
 
     case Token::VAR:
     case Token::CONST:
       return ParseVariableStatement(kStatement, NULL, ok);
 
     case Token::LET:
       DCHECK(allow_harmony_scoping());
       if (strict_mode() == STRICT) {
@@ skipping 248 matching lines @@
           scope_->is_function_scope()) ? LET : VAR;
   VariableProxy* proxy = NewUnresolved(name, mode, Interface::NewValue());
   Declaration* declaration =
       factory()->NewFunctionDeclaration(proxy, mode, fun, scope_, pos);
   Declare(declaration, true, CHECK_OK);
   if (names) names->Add(name, zone());
   return factory()->NewEmptyStatement(RelocInfo::kNoPosition);
 }
 
 
+Statement* Parser::ParseClassDeclaration(ZoneList<const AstRawString*>* names,
+                                         bool* ok) {
+  // ClassDeclaration ::
+  //   'class' Identifier ('extends' LeftHandExpression)? '{' ClassBody '}'
+  //
+  // A ClassDeclaration
+  //
+  //   class C { ... }
+  //
+  // has the same semantics as:
+  //
+  //   let C = class C { ... };
+  //
+  // so rewrite it as such.
+
+  Expect(Token::CLASS, CHECK_OK);
+  int pos = position();
+  bool is_strict_reserved = false;
+  const AstRawString* name =
+      ParseIdentifierOrStrictReservedWord(&is_strict_reserved, CHECK_OK);
+  ClassLiteral* value = ParseClassLiteral(name, scanner()->location(),
+                                          is_strict_reserved, pos, CHECK_OK);
+
+  Block* block = factory()->NewBlock(NULL, 1, true, pos);
+  VariableMode mode = LET;
+  VariableProxy* proxy = NewUnresolved(name, mode, Interface::NewValue());
+  Declaration* declaration =
+      factory()->NewVariableDeclaration(proxy, mode, scope_, pos);
+  Declare(declaration, true, CHECK_OK);
+
+  Token::Value init_op = Token::INIT_LET;
+  Assignment* assignment = factory()->NewAssignment(init_op, proxy, value, pos);
+  block->AddStatement(
+      factory()->NewExpressionStatement(assignment, RelocInfo::kNoPosition),
+      zone());
+
+  if (names) names->Add(name, zone());
+  return block;
+}
+
+
 Block* Parser::ParseBlock(ZoneList<const AstRawString*>* labels, bool* ok) {
   if (allow_harmony_scoping() && strict_mode() == STRICT) {
     return ParseScopedBlock(labels, ok);
   }
 
   // Block ::
   //   '{' Statement* '}'
 
   // Note that a Block does not introduce a new execution scope!
   // (ECMA-262, 3rd, 12.2)
@@ skipping 2917 matching lines @@
   DCHECK(ast_value_factory_->IsInternalized());
   // info takes ownership of ast_value_factory_.
   if (info()->ast_value_factory() == NULL) {
     info()->SetAstValueFactory(ast_value_factory_);
   }
   ast_value_factory_ = NULL;
   return (result != NULL);
 }
 
 } }  // namespace v8::internal