/*
* Copyright (C) 2009-2010 Mathias Doenitz
*
* 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 org.parboiled.transform;
import org.jetbrains.annotations.NotNull;
import org.objectweb.asm.tree.AbstractInsnNode;
/**
* Removes all unused labels.
*/
class UnusedLabelsRemover implements RuleMethodProcessor {
public boolean appliesTo(@NotNull ParserClassNode classNode, @NotNull RuleMethod method) {
return true;
}
@SuppressWarnings({"SuspiciousMethodCalls"})
public void process(@NotNull ParserClassNode classNode, @NotNull RuleMethod method) throws Exception {
AbstractInsnNode current = method.instructions.getFirst();
while (current != null) {
AbstractInsnNode next = current.getNext();
if (current.getType() == AbstractInsnNode.LABEL && !method.getUsedLabels().contains(current)) {
method.instructions.remove(current);
}
current = next;
}
}
}