Disallow legacy try-catch syntax.

lib/compiler/implementation/resolver.dart

 // 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.
 
 interface TreeElements {
   Element operator[](Node node);
   Selector getSelector(Send send);
   DartType getType(TypeAnnotation annotation);
 }
 
@@ skipping 1828 matching lines @@
     if (node.catchBlocks.isEmpty() && node.finallyBlock == null) {
       // TODO(ngeoffray): The precise location is
       // node.getEndtoken.next. Adjust when issue #1581 is fixed.
       error(node, MessageKind.NO_CATCH_NOR_FINALLY);
     }
     visit(node.catchBlocks);
     visit(node.finallyBlock);
   }
 
   visitCatchBlock(CatchBlock node) {
-    Scope blockScope = new BlockScope(scope);
+    // Check that the catch has one or two formal parameters.
     if (node.formals.isEmpty()) {
       error(node, MessageKind.EMPTY_CATCH_DECLARATION);
     } else if (!node.formals.nodes.tail.isEmpty()
                && !node.formals.nodes.tail.tail.isEmpty()) {
       for (Node extra in node.formals.nodes.tail.tail) {
         error(extra, MessageKind.EXTRA_CATCH_DECLARATION);
       }
     }
+
+    // Check that the formals aren't optional and that they have no
+    // modifiers or type.
+    for (Link<Node> link = node.formals.nodes;
+         !link.isEmpty();
+         link = link.tail) {
+      // If the formal parameter is a node list, it means that it is a
+      // sequence of optional parameters.
+      NodeList nodeList = link.head.asNodeList();
+      if (nodeList !== null) {
+        error(nodeList, MessageKind.OPTIONAL_PARAMETER_IN_CATCH);
+      } else {
+        VariableDefinitions declaration = link.head;
+        for (Node modifier in declaration.modifiers.nodes) {
+          error(modifier, MessageKind.PARAMETER_WITH_MODIFIER_IN_CATCH);
+        }
+        TypeAnnotation type = declaration.type;
+        if (type !== null) {
+          error(type, MessageKind.PARAMETER_WITH_TYPE_IN_CATCH);
+        }
+      }
+    }
+
+    Scope blockScope = new BlockScope(scope);
     visitIn(node.type, blockScope);
     visitIn(node.formals, blockScope);
     visitIn(node.block, blockScope);
   }
 
   visitTypedef(Typedef node) {
     unimplemented(node, 'typedef');
   }
 }
 
@@ skipping 768 matching lines @@
   TopScope(LibraryElement library) : super(null, library);
   Element lookup(SourceString name) {
     return library.find(name);
   }
 
   Element add(Element newElement) {
     throw "Cannot add an element in the top scope";
   }
   String toString() => '$element';
 }