/*
 * FindBugs - Find Bugs in Java programs
 * Copyright (C) 2006, University of Maryland
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package edu.umd.cs.findbugs.detect;

import static org.apache.bcel.Constants.I2D;
import static org.apache.bcel.Constants.INVOKESTATIC;

import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.Detector2;
import edu.umd.cs.findbugs.MethodAnnotation;
import edu.umd.cs.findbugs.asm.AbstractFBMethodVisitor;
import edu.umd.cs.findbugs.asm.ClassNodeDetector;

/**
 * Sample detector, using ASM
 * 
 * @author David Hovemeyer
 */
public class TestASM extends ClassNodeDetector {

	public TestASM(BugReporter bugReporter) {
		super(bugReporter);
	}

	@Override
	public MethodVisitor visitMethod(final int access, final String name, final String desc, final String signature,
	        final String[] exceptions) {
		if (Character.isUpperCase(name.charAt(0))) {
			BugInstance bug0 = new BugInstance(this, "NM_METHOD_NAMING_CONVENTION", NORMAL_PRIORITY).addClass(this).addMethod(
			        this.name, name, desc, access);
			bugReporter.reportBug(bug0);
		}
		return new AbstractFBMethodVisitor() {
			int prevOpcode;

			int prevPC;

			@Override
			public void visitInsn(int opcode) {
				prevOpcode = opcode;
				prevPC = getPC();
			}

			@Override
			public void visitMethodInsn(int opcode, String owner, String invokedName, String invokedDesc) {
				if (prevPC + 1 == getPC() && prevOpcode == I2D && opcode == INVOKESTATIC && owner.equals("java/lang/Math")
				        && invokedName.equals("ceil") && invokedDesc.equals("(D)D")) {
					BugInstance bug0 = new BugInstance(TestASM.this, "ICAST_INT_CAST_TO_DOUBLE_PASSED_TO_CEIL", NORMAL_PRIORITY);
					MethodAnnotation methodAnnotation = MethodAnnotation.fromForeignMethod(TestASM.this.name, name, desc, access);
					bug0.addClass(TestASM.this).addMethod(methodAnnotation);
					bugReporter.reportBug(bug0);
				}
			}
		};

	}

	@Override
	public FieldVisitor visitField(int access, String name, String desc, String signature, Object value) {
		if ((access & Opcodes.ACC_STATIC) != 0 && (access & Opcodes.ACC_FINAL) != 0 && (access & Opcodes.ACC_PUBLIC) != 0
		        && !name.equals(name.toUpperCase()))
			bugReporter.reportBug(new BugInstance(this, "NM_FIELD_NAMING_CONVENTION", Detector2.LOW_PRIORITY).addClass(this)
			        .addField(this.name, name, desc, access));
		return null;
	}

}
