/*
* 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 com.google.common.base.Preconditions;
import org.jetbrains.annotations.NotNull;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.InsnList;
import org.objectweb.asm.tree.MethodInsnNode;
/**
* Replaces the method code with a simple call to the super method.
*/
class SuperCallRewriter implements RuleMethodProcessor, Opcodes {
public boolean appliesTo(@NotNull ParserClassNode classNode, @NotNull RuleMethod method) {
return method.containsPotentialSuperCalls();
}
public void process(@NotNull ParserClassNode classNode, @NotNull RuleMethod method) throws Exception {
InsnList instructions = method.instructions;
AbstractInsnNode insn = instructions.getFirst();
while (insn.getOpcode() != ARETURN) {
if (insn.getOpcode() == INVOKESPECIAL) {
process(classNode, method, (MethodInsnNode) insn);
}
insn = insn.getNext();
}
}
private void process(ParserClassNode classNode, RuleMethod method, MethodInsnNode insn) {
if ("<init>".equals(insn.name)) return;
String superMethodName = getSuperMethodName(method, insn);
RuleMethod superMethod = classNode.getRuleMethods().get(superMethodName.concat(insn.desc));
if (superMethod == null) return;
if (!superMethod.isBodyRewritten()) return;
// since the super method is rewritten we do need to generate it
superMethod.dontSkipGeneration();
// we have a call to a super method that was rewritten, so we need to change the call to the generated method
insn.setOpcode(INVOKEVIRTUAL);
insn.name = superMethodName;
insn.owner = classNode.name;
method.setBodyRewritten();
}
@SuppressWarnings({"ConstantConditions"})
private String getSuperMethodName(RuleMethod method, MethodInsnNode insn) {
Class<?> clazz = method.getOwnerClass();
String superMethodName = method.name;
do {
clazz = clazz.getSuperclass();
Preconditions.checkState(clazz != null); // we should find the owner before hitting Object
superMethodName = '$' + superMethodName;
} while (!Type.getInternalName(clazz).equals(insn.owner));
return superMethodName;
}
}