Fix bug in parser that allows "(foo):42" as a labeled statement.

Fixes issue 918.

Review URL: http://codereview.chromium.org/5044003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5830 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/parser.cc

@@ -1692,11 +1692,13 @@ Statement* Parser::ParseExpressionOrLabelledStatement(ZoneStringList* labels,
   // ExpressionStatement | LabelledStatement ::
   //   Expression ';'
   //   Identifier ':' Statement
-
+  bool starts_with_idenfifier = (peek() == Token::IDENTIFIER);
   Expression* expr = ParseExpression(true, CHECK_OK);
-  if (peek() == Token::COLON && expr &&
+  if (peek() == Token::COLON && starts_with_idenfifier && expr &&
       expr->AsVariableProxy() != NULL &&
       !expr->AsVariableProxy()->is_this()) {
+    // Expression is a single identifier, and not, e.g., a parenthesized
+    // identifier.
     VariableProxy* var = expr->AsVariableProxy();
     Handle<String> label = var->name();
     // TODO(1240780): We don't check for redeclaration of labels

test/mjsunit/regress/regress-918.js

+// Copyright 2010 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Parser should not accept parentheses around labels.
+// See http://code.google.com/p/v8/issues/detail?id=918
+
+// The label was parsed as an expression and then tested for being a 
+// single identifier. This threw away the parentheses.
+assertThrows("(label):42;");