// Copyright (C) 2008 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.caja.parser.quasiliteral;
import com.google.caja.parser.ParseTreeNodeVisitor;
import com.google.caja.parser.ParseTreeNode;
import com.google.caja.parser.js.Identifier;
import com.google.caja.parser.js.SyntheticNodes;
import com.google.caja.reporting.MessageQueue;
/**
* Non-ASCII characters can change the semantics of a program depending on how
* they're rendered, so we forbid them outside of strings.
*
* @author metaweta@gmail.com (Mike Stay)
*/
public final class NonAsciiCheckVisitor implements ParseTreeNodeVisitor {
private final MessageQueue mq;
public NonAsciiCheckVisitor(MessageQueue mq) {
this.mq = mq;
}
/**
* Add an error to the queue if an identifier contains non-ASCII characters.
*/
public boolean visit(ParseTreeNode node) {
if (!(node instanceof Identifier)) { return true; }
Identifier ident = (Identifier) node;
String name = ident.getName();
if (!SyntheticNodes.is(ident)
&& name != null && !name.matches("^[a-zA-Z_$][a-zA-Z0-9_$]*$")) {
mq.addMessage(
RewriterMessageType.NONASCII_IDENTIFIER,
node.getFilePosition(), node);
}
return true;
}
}