/*
 * Bytecode Analysis Framework
 * Copyright (C) 2003-2007 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.classfile.engine.bcel;

import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.MethodGen;

import edu.umd.cs.findbugs.ba.AnalysisContext;
import edu.umd.cs.findbugs.ba.AnalysisFeatures;
import edu.umd.cs.findbugs.ba.JavaClassAndMethod;
import edu.umd.cs.findbugs.classfile.CheckedAnalysisException;
import edu.umd.cs.findbugs.classfile.IAnalysisCache;
import edu.umd.cs.findbugs.classfile.MethodDescriptor;

/**
 * Analysis engine to produce MethodGen objects
 * for analyzed methods.
 * 
 * @author David Hovemeyer
 * @author Bill Pugh
 */
public class MethodGenFactory extends AnalysisFactory<MethodGen> {
	/**
	 * Constructor.
	 */
    public MethodGenFactory() {
	    super("MethodGen construction", MethodGen.class);
    }
    
    /* (non-Javadoc)
     * @see edu.umd.cs.findbugs.classfile.IAnalysisEngine#analyze(edu.umd.cs.findbugs.classfile.IAnalysisCache, java.lang.Object)
     */
    public MethodGen analyze(IAnalysisCache analysisCache, MethodDescriptor descriptor) throws CheckedAnalysisException {
    	Method method = getMethod(analysisCache, descriptor);
    	
    	if (method.getCode() == null)
    		return null;
    	try {
    		AnalysisContext analysisContext = AnalysisContext.currentAnalysisContext();
    		JavaClass jclass = getJavaClass(analysisCache, descriptor.getClassDescriptor());
    		ConstantPoolGen cpg = getConstantPoolGen(analysisCache, descriptor.getClassDescriptor());

    		String methodName = method.getName();
    		int codeLength = method.getCode().getLength();
			String superclassName = jclass.getSuperclassName();
			if (codeLength > 6000 && methodName.equals("<clinit>") && superclassName.equals("java.lang.Enum")) {
				analysisContext.getLookupFailureCallback().reportSkippedAnalysis(new JavaClassAndMethod(jclass, method).toMethodDescriptor());
				return null;
			}
    		if (analysisContext.getBoolProperty(AnalysisFeatures.SKIP_HUGE_METHODS)) {
    			if (codeLength > 3000 
    					|| (methodName.equals("<clinit>") || methodName.equals("getContents")) && codeLength > 1000) {
    				analysisContext.getLookupFailureCallback().reportSkippedAnalysis(new JavaClassAndMethod(jclass, method).toMethodDescriptor());
    				return null;
    			}
    		}

    		return new MethodGen(method, jclass.getClassName(), cpg);
    	} catch (Exception e) {
    		AnalysisContext.logError("Error constructing methodGen", e);
    		return null;
    	}
    }
}
