Fix for issue 3756 - support new catch syntax

compiler/java/com/google/dart/compiler/parser/DartParser.java

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 package com.google.dart.compiler.parser;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.io.CharStreams;
 import com.google.dart.compiler.DartCompilationError;
@@ skipping 130 matching lines @@
   private static final String EQUALS_KEYWORD = "equals";
   //private static final String EXPORT_KEYWORD = "export";
   private static final String EXTERNAL_KEYWORD = "external";
   private static final String FACTORY_KEYWORD = "factory";
   private static final String GETTER_KEYWORD = "get";
   //private static final String HIDE_KEYWORD = "hide";
   private static final String IMPLEMENTS_KEYWORD = "implements";
   private static final String INTERFACE_KEYWORD = "interface";
   private static final String NATIVE_KEYWORD = "native";
   private static final String NEGATE_KEYWORD = "negate";
-  //private static final String ON_KEYWORD = "on";
+  private static final String ON_KEYWORD = "on";
   private static final String OPERATOR_KEYWORD = "operator";
   private static final String PREFIX_KEYWORD = "prefix";
   private static final String SETTER_KEYWORD = "set";
   //private static final String SHOW_KEYWORD = "show";
   private static final String STATIC_KEYWORD = "static";
   private static final String TYPEDEF_KEYWORD = "typedef";
 
 
   public static final String[] PSEUDO_KEYWORDS = {
     ABSTRACT_KEYWORD,
@@ skipping 4235 matching lines @@
    *
    * finallyPart
    *     : FINALLY block
    *     ;
    * </pre>
    */
   private DartTryStatement parseTryStatement() {
     beginTryStatement();
     // Try.
     expect(Token.TRY);
-    // TODO(zundel): It would be nice here to setup 'CATCH' and 'FINALLY' as tokens for recovery
+    // TODO(zundel): It would be nice here to setup 'ON', 'CATCH' and 'FINALLY' as tokens for recovery
     DartBlock tryBlock = parseBlock();
 
     List<DartCatchBlock> catches = new ArrayList<DartCatchBlock>();
-    while (/*peekPseudoKeyword(0, ON_KEYWORD) ||*/ match(Token.CATCH)) {
+    while (peekPseudoKeyword(0, ON_KEYWORD) || match(Token.CATCH)) {
       // TODO(zundel): It would be nice here to setup 'FINALLY' as token for recovery
-//      if (peekPseudoKeyword(0, ON_KEYWORD)) {
-//        beginCatchClause();
-//        next();
-//        DartTypeNode exceptionType = new DartTypeNode(parseQualified());
-//        DartParameter exception = null;
-//        DartParameter stackTrace = null;
-//        if (optional(Token.CATCH)) {
-//          expect(Token.LPAREN);
-//          beginCatchParameter();
-//          DartIdentifier exceptionName = parseIdentifier();
-//          exception = done(new DartParameter(exceptionName, exceptionType, null, null, Modifiers.NONE));
-//          if (optional(Token.COMMA)) {
-//            beginCatchParameter();
-//            DartIdentifier stackName = parseIdentifier();
-//            stackTrace = done(new DartParameter(stackName, null, null, null, Modifiers.NONE));
-//          }
-//          expectCloseParen();
-//        } else {
-//          // Create a dummy identifier that the user cannot reliably reference.
-//          DartIdentifier exceptionName = new DartIdentifier("e" + Long.toHexString(System.currentTimeMillis()));
-//          exception = new DartParameter(exceptionName, exceptionType, null, null, Modifiers.NONE);
-//        }
-//        DartBlock block = parseBlock();
-//        catches.add(done(new DartCatchBlock(block, exception, stackTrace)));
-//      } else {
+      if (peekPseudoKeyword(0, ON_KEYWORD)) {
+        beginCatchClause();
+        next();
+        DartTypeNode exceptionType = new DartTypeNode(parseQualified());
+        DartParameter exception = null;
+        DartParameter stackTrace = null;
+        if (optional(Token.CATCH)) {
+          expect(Token.LPAREN);
+          beginCatchParameter();
+          DartIdentifier exceptionName = parseIdentifier();
+          exception = done(new DartParameter(exceptionName, exceptionType, null, null, Modifiers.NONE));
+          if (optional(Token.COMMA)) {
+            beginCatchParameter();
+            DartIdentifier stackName = parseIdentifier();
+            stackTrace = done(new DartParameter(stackName, null, null, null, Modifiers.NONE));
+          }
+          expectCloseParen();
+        } else {
+          // Create a dummy identifier that the user cannot reliably reference.
+          DartIdentifier exceptionName = new DartIdentifier("e" + Long.toHexString(System.currentTimeMillis()));
+          exception = new DartParameter(exceptionName, exceptionType, null, null, Modifiers.NONE);
+        }
+        DartBlock block = parseBlock();
+        catches.add(done(new DartCatchBlock(block, exception, stackTrace)));
+      } else {
         beginCatchClause();
         next();
         expect(Token.LPAREN);
-//        if (match(Token.IDENTIFIER) && (peek(1) == Token.COMMA || peek(1) == Token.RPAREN)) {
-//          beginCatchParameter();
-//          DartIdentifier exceptionName = parseIdentifier();
-//          // Create a dummy type with the right semantics.
-//          DartTypeNode exceptionType = new DartTypeNode(new DartIdentifier("Object"));
-//          DartParameter exception = done(new DartParameter(exceptionName, exceptionType, null, null, Modifiers.NONE));
-//          DartParameter stackTrace = null;
-//          if (optional(Token.COMMA)) {
-//            beginCatchParameter();
-//            DartIdentifier stackName = parseIdentifier();
-//            stackTrace = done(new DartParameter(stackName, null, null, null, Modifiers.NONE));
-//          }
-//          expectCloseParen();
-//          DartBlock block = parseBlock();
-//          catches.add(done(new DartCatchBlock(block, exception, stackTrace)));
-//        } else {
-          DartParameter exception = parseCatchParameter();
-          DartParameter stackTrace = null;
-          if (optional(Token.COMMA)) {
+        DartParameter exception;
+        if (match(Token.IDENTIFIER) && (peek(1) == Token.COMMA || peek(1) == Token.RPAREN)) {
+          beginCatchParameter();
+          DartIdentifier exceptionName = parseIdentifier();
+          exception = done(new DartParameter(exceptionName, null , null, null, Modifiers.NONE));
+        } else {
+          // Old-style parameter
+          exception = parseCatchParameter();
+        }
+        DartParameter stackTrace = null;
+        if (optional(Token.COMMA)) {
+          if (match(Token.IDENTIFIER) && peek(1) == Token.RPAREN) {
+            beginCatchParameter();
+            DartIdentifier stackName = parseIdentifier();
+            stackTrace = done(new DartParameter(stackName, null, null, null, Modifiers.NONE));
+          } else {
+            // Old-style parameter
             stackTrace = parseCatchParameter();
           }
-          expectCloseParen();
-          DartBlock block = parseBlock();
-          catches.add(done(new DartCatchBlock(block, exception, stackTrace)));
         }
-//      }
-//    }
+        expectCloseParen();
+        DartBlock block = parseBlock();
+        catches.add(done(new DartCatchBlock(block, exception, stackTrace)));
+      }
+    }
 
     // Finally.
     DartBlock finallyBlock = null;
     if (optional(Token.FINALLY)) {
       finallyBlock = parseBlock();
     }
 
     if ( catches.size() == 0 && finallyBlock == null) {
       reportError(new DartCompilationError(tryBlock.getSourceInfo().getSource(), new Location(position()),
         ParserErrorCode.CATCH_OR_FINALLY_EXPECTED));
@@ skipping 266 matching lines @@
   private void reportError(DartNode node, ErrorCode errorCode, Object... arguments) {
     if (node != null) {
       reportError(new DartCompilationError(node, errorCode, arguments));
     }
   }
 
   private boolean currentlyParsingToplevel() {
     return   !(isParsingInterface || isTopLevelAbstract || isParsingClass);
   }
 }