(Pre)Parser: Simplify NewExpression handling.

src/preparser.cc

 // Copyright 2011 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 989 matching lines @@
     return Expression::Default();
   }
   return expression;
 }
 
 
 PreParser::Expression PreParser::ParseLeftHandSideExpression(bool* ok) {
   // LeftHandSideExpression ::
   //   (NewExpression | MemberExpression) ...
 
-  Expression result = Expression::Default();
-  if (peek() == Token::NEW) {
-    result = ParseNewExpression(CHECK_OK);
-  } else {
-    result = ParseMemberExpression(CHECK_OK);
-  }
+  Expression result = ParseMemberWithNewPrefixesExpression(CHECK_OK);
 
   while (true) {
     switch (peek()) {
       case Token::LBRACK: {
         Consume(Token::LBRACK);
         ParseExpression(true, CHECK_OK);
         Expect(Token::RBRACK, CHECK_OK);
         if (result.IsThis()) {
           result = Expression::ThisProperty();
         } else {
@@ skipping 19 matching lines @@
         break;
       }
 
       default:
         return result;
     }
   }
 }
 
 
-PreParser::Expression PreParser::ParseNewExpression(bool* ok) {
+PreParser::Expression PreParser::ParseMemberWithNewPrefixesExpression(
+    bool* ok) {
   // NewExpression ::
   //   ('new')+ MemberExpression
 
-  // The grammar for new expressions is pretty warped. The keyword
-  // 'new' can either be a part of the new expression (where it isn't
-  // followed by an argument list) or a part of the member expression,
-  // where it must be followed by an argument list. To accommodate
-  // this, we parse the 'new' keywords greedily and keep track of how
-  // many we have parsed. This information is then passed on to the
-  // member expression parser, which is only allowed to match argument
-  // lists as long as it has 'new' prefixes left
-  unsigned new_count = 0;
-  do {
+  // See Parser::ParseNewExpression.
+
+  if (peek() == Token::NEW) {
     Consume(Token::NEW);
-    new_count++;
-  } while (peek() == Token::NEW);
-
-  return ParseMemberWithNewPrefixesExpression(new_count, ok);
+    ParseMemberWithNewPrefixesExpression(CHECK_OK);
+    if (peek() == Token::LPAREN) {
+      // NewExpression with arguments.
+      ParseArguments(CHECK_OK);
+    }
+    return Expression::Default();
+  }
+  // No 'new' keyword.
+  return ParseMemberExpression(ok);
 }
 
 
 PreParser::Expression PreParser::ParseMemberExpression(bool* ok) {
-  return ParseMemberWithNewPrefixesExpression(0, ok);
-}
-
-
-PreParser::Expression PreParser::ParseMemberWithNewPrefixesExpression(
-    unsigned new_count, bool* ok) {
   // MemberExpression ::
   //   (PrimaryExpression | FunctionLiteral)
   //     ('[' Expression ']' | '.' Identifier | Arguments)*
 
   // Parse the initial primary or function expression.
   Expression result = Expression::Default();
   if (peek() == Token::FUNCTION) {
     Consume(Token::FUNCTION);
 
     bool is_generator = allow_generators() && Check(Token::MUL);
@@ skipping 30 matching lines @@
       case Token::PERIOD: {
         Consume(Token::PERIOD);
         ParseIdentifierName(CHECK_OK);
         if (result.IsThis()) {
           result = Expression::ThisProperty();
         } else {
           result = Expression::Default();
         }
         break;
       }
-      case Token::LPAREN: {
-        if (new_count == 0) return result;
-        // Consume one of the new prefixes (already parsed).
-        ParseArguments(CHECK_OK);
-        new_count--;
-        result = Expression::Default();
-        break;
-      }
       default:
         return result;
     }
   }
 }
 
 
 PreParser::Expression PreParser::ParseArrayLiteral(bool* ok) {
   // ArrayLiteral ::
   //   '[' Expression? (',' Expression?)* ']'
@@ skipping 268 matching lines @@
   int identifier_pos = position();
   if (scanner()->is_literal_ascii()) {
     log_->LogAsciiSymbol(identifier_pos, scanner()->literal_ascii_string());
   } else {
     log_->LogUtf16Symbol(identifier_pos, scanner()->literal_utf16_string());
   }
 }
 
 
 } }  // v8::internal