Add parser support for generators.

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 3576 matching lines @@
       Consume(Token::TRUE_LITERAL);
       result = factory()->NewLiteral(isolate()->factory()->true_value());
       break;
 
     case Token::FALSE_LITERAL:
       Consume(Token::FALSE_LITERAL);
       result = factory()->NewLiteral(isolate()->factory()->false_value());
       break;
 
     case Token::IDENTIFIER:
+    case Token::YIELD:
     case Token::FUTURE_STRICT_RESERVED_WORD: {
       Handle<String> name = ParseIdentifier(CHECK_OK);
       if (fni_ != NULL) fni_->PushVariableName(name);
       // The name may refer to a module instance object, so its type is unknown.
 #ifdef DEBUG
       if (FLAG_print_interface_details)
         PrintF("# Variable %s ", name->ToAsciiArray());
 #endif
       Interface* interface = Interface::NewUnknown(zone());
       result = top_scope_->NewUnresolved(
@@ skipping 1048 matching lines @@
 
   // We have a valid intrinsics call or a call to a builtin.
   return factory()->NewCallRuntime(name, function, args);
 }
 
 
 bool Parser::peek_any_identifier() {
   Token::Value next = peek();
   return next == Token::IDENTIFIER ||
          next == Token::FUTURE_RESERVED_WORD ||
-         next == Token::FUTURE_STRICT_RESERVED_WORD;
+         next == Token::FUTURE_STRICT_RESERVED_WORD ||
+         next == Token::YIELD;
 }
 
 
 void Parser::Consume(Token::Value token) {
   Token::Value next = Next();
   USE(next);
   USE(token);
   ASSERT(next == token);
 }
 
@@ skipping 54 matching lines @@
   return factory()->NewLiteral(isolate()->factory()->the_hole_value());
 }
 
 
 // Parses an identifier that is valid for the current scope, in particular it
 // fails on strict mode future reserved keywords in a strict scope.
 Handle<String> Parser::ParseIdentifier(bool* ok) {
   if (!top_scope_->is_classic_mode()) {
     Expect(Token::IDENTIFIER, ok);
   } else if (!Check(Token::IDENTIFIER)) {
-    Expect(Token::FUTURE_STRICT_RESERVED_WORD, ok);
+    if (Check(Token::YIELD))
+      *ok = !inside_generator();
+    else
+      Expect(Token::FUTURE_STRICT_RESERVED_WORD, ok);
   }
   if (!*ok) return Handle<String>();
   return GetSymbol(ok);
 }
 
 
 // Parses and identifier or a strict mode future reserved word, and indicate
 // whether it is strict mode future reserved.
 Handle<String> Parser::ParseIdentifierOrStrictReservedWord(
     bool* is_strict_reserved, bool* ok) {
   *is_strict_reserved = false;
   if (!Check(Token::IDENTIFIER)) {
-    Expect(Token::FUTURE_STRICT_RESERVED_WORD, ok);
-    *is_strict_reserved = true;
+    if (Check(Token::YIELD)) {
+      if (inside_generator())
+        *ok = false;
+      else
+        *is_strict_reserved = true;
+    } else {
+      Expect(Token::FUTURE_STRICT_RESERVED_WORD, ok);
+      *is_strict_reserved = true;
+    }
   }
   if (!*ok) return Handle<String>();
   return GetSymbol(ok);
 }
 
 
 Handle<String> Parser::ParseIdentifierName(bool* ok) {
   Token::Value next = Next();
   if (next != Token::IDENTIFIER &&
       next != Token::FUTURE_RESERVED_WORD &&
@@ skipping 1167 matching lines @@
       ASSERT(info->isolate()->has_pending_exception());
     } else {
       result = parser.ParseProgram();
     }
   }
   info->SetFunction(result);
   return (result != NULL);
 }
 
 } }  // namespace v8::internal