[es6] early error when Identifier is an escaped reserved word

src/preparser.cc

 // Copyright 2011 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 <cmath>
 
 #include "src/allocation.h"
 #include "src/base/logging.h"
 #include "src/conversions-inl.h"
 #include "src/conversions.h"
@@ skipping 137 matching lines @@
 
 
 PreParserExpression PreParserTraits::ParseClassLiteral(
     PreParserIdentifier name, Scanner::Location class_name_location,
     bool name_is_strict_reserved, int pos, bool* ok) {
   return pre_parser_->ParseClassLiteral(name, class_name_location,
                                         name_is_strict_reserved, pos, ok);
 }
 
 
+#define CHECK_OK  ok);                   \
+  if (!*ok) return Statement::Default(); \
+  ((void)0
+#define DUMMY )  // to make indentation work
+#undef DUMMY
+
+
 // Preparsing checks a JavaScript program and emits preparse-data that helps
 // a later parsing to be faster.
 // See preparser-data.h for the data.
 
 // The PreParser checks that the syntax follows the grammar for JavaScript,
 // and collects some information about the program along the way.
 // The grammar check is only performed in order to understand the program
 // sufficiently to deduce some information about it, that can be used
 // to speed up later parsing. Finding errors is not the goal of pre-parsing,
 // rather it is to speed up properly written and correct programs.
@@ skipping 27 matching lines @@
     case Token::CONST:
       if (allow_const()) {
         return ParseVariableStatement(kStatementListItem, ok);
       }
       break;
     case Token::LET:
       if (IsNextLetKeyword()) {
         return ParseVariableStatement(kStatementListItem, ok);
       }
       break;
+    case Token::IDENTIFIER:
+      CheckNextEscapedKeyword(CHECK_OK);
+      break;
     default:
       break;
   }
   return ParseStatement(ok);
 }
 
 
 void PreParser::ParseStatementList(int end_token, bool* ok,
                                    Scanner::BookmarkScope* bookmark) {
   // SourceElements ::
@@ skipping 82 matching lines @@
       if (count_statements > kLazyParseTrialLimit) {
         bookmark->Reset();
         return;
       }
       maybe_reset = false;
     }
   }
 }
 
 
-#define CHECK_OK  ok);                   \
-  if (!*ok) return Statement::Default();  \
-  ((void)0
-#define DUMMY )  // to make indentation work
-#undef DUMMY
-
-
 PreParser::Statement PreParser::ParseStatement(bool* ok) {
   // Statement ::
   //   EmptyStatement
   //   ...
 
   if (peek() == Token::SEMICOLON) {
     Next();
     return Statement::Default();
   }
   return ParseSubStatement(ok);
@@ skipping 930 matching lines @@
     Expect(Token::RBRACE, CHECK_OK);
     return PreParserExpression::Default();
   }
 }
 
 #undef CHECK_OK
 
 
 }  // namespace internal
 }  // namespace v8