Copyright (c) 2004 IBM Corporation and others.
All rights reserved. This program and the accompanying materials 
are made available under the terms of the Eclipse Public License v1.0
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/epl-v10.html
Contributors:
    IBM Corporation - initial API and implementation
     (Andy Clement)
/*******************************************************************************
 * Copyright (c) 2004 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *      (Andy Clement)
 *******************************************************************************/

package org.aspectj.weaver.bcel;

import org.aspectj.apache.bcel.Constants;
import org.aspectj.apache.bcel.generic.FieldGen;
import org.aspectj.apache.bcel.generic.InstructionFactory;
import org.aspectj.apache.bcel.generic.InstructionList;
import org.aspectj.apache.bcel.generic.ObjectType;
import org.aspectj.apache.bcel.generic.Type;
import org.aspectj.weaver.Member;
import org.aspectj.weaver.NameMangler;
import org.aspectj.weaver.ResolvedMember;
import org.aspectj.weaver.ResolvedType;

This type munger will modify a given class (see the munge() method) to include a field representing a CflowCounter object.
/**
 * This type munger will modify a given class (see the munge() method) to include a field representing a CflowCounter object.
 */
public class BcelCflowCounterFieldAdder extends BcelTypeMunger {
	private ResolvedMember cflowCounterField;

	public BcelCflowCounterFieldAdder(ResolvedMember cflowCounterField) {
		super(null, (ResolvedType) cflowCounterField.getDeclaringType());
		this.cflowCounterField = cflowCounterField;
	}

	public boolean munge(BcelClassWeaver weaver) {
		LazyClassGen gen = weaver.getLazyClassGen();

		// Only munge one type!
		if (!gen.getType().equals(cflowCounterField.getDeclaringType()))
			return false;

		// Create the field declaration.
		// Something like: "public static final CflowCounter ajc$cflowCounter$0;"
		FieldGen f = new FieldGen(cflowCounterField.getModifiers(), BcelWorld.makeBcelType(cflowCounterField.getReturnType()),
				cflowCounterField.getName(), gen.getConstantPool());

		gen.addField(f, getSourceLocation());

		// Modify the ajc$preClinit() method to initialize it.
		// Something like: "ajc$cflowCounter$0 = new CflowCounter();"
		LazyMethodGen clinit = gen.getAjcPreClinit(); // StaticInitializer();
		InstructionList setup = new InstructionList();
		InstructionFactory fact = gen.getFactory();

		setup.append(fact.createNew(new ObjectType(NameMangler.CFLOW_COUNTER_TYPE)));
		setup.append(InstructionFactory.createDup(1));
		setup.append(fact.createInvoke(NameMangler.CFLOW_COUNTER_TYPE, "<init>", Type.VOID, new Type[0], Constants.INVOKESPECIAL));

		setup.append(Utility.createSet(fact, cflowCounterField));
		clinit.getBody().insert(setup);

		return true;
	}

	public ResolvedMember getMatchingSyntheticMember(Member member) {
		return null;
	}

	public ResolvedMember getSignature() {
		return cflowCounterField;
	}

	public boolean matches(ResolvedType onType) {
		return onType.equals(cflowCounterField.getDeclaringType());
	}

	public boolean existsToSupportShadowMunging() {
		return true;
	}

	public String toString() {
		return "(BcelTypeMunger: CflowField " + cflowCounterField.getDeclaringType().getName() + " " + cflowCounterField.getName()
				+ ")";
	}

}