/*
* FindBugs - Find Bugs in Java programs
* 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.generic.MethodGen;
import edu.umd.cs.findbugs.ba.CFG;
import edu.umd.cs.findbugs.ba.ClassContext;
import edu.umd.cs.findbugs.ba.MethodUnprofitableException;
import edu.umd.cs.findbugs.ba.deref.UnconditionalValueDerefAnalysis;
import edu.umd.cs.findbugs.ba.deref.UnconditionalValueDerefDataflow;
import edu.umd.cs.findbugs.ba.npe.IsNullValueDataflow;
import edu.umd.cs.findbugs.ba.type.TypeDataflow;
import edu.umd.cs.findbugs.ba.vna.ValueNumberDataflow;
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 UnconditionalValueDerefDataflow objects for
* analyzed methods.
*
* @author David Hovemeyer
*/
public class UnconditionalValueDerefDataflowFactory extends AnalysisFactory<UnconditionalValueDerefDataflow> {
/**
* Constructor.
*/
public UnconditionalValueDerefDataflowFactory() {
super("unconditional value dereference analysis", UnconditionalValueDerefDataflow.class);
}
/*
* (non-Javadoc)
*
* @see
* edu.umd.cs.findbugs.classfile.IAnalysisEngine#analyze(edu.umd.cs.findbugs
* .classfile.IAnalysisCache, java.lang.Object)
*/
@Override
public UnconditionalValueDerefDataflow analyze(IAnalysisCache analysisCache, MethodDescriptor descriptor)
throws CheckedAnalysisException {
MethodGen methodGen = getMethodGen(analysisCache, descriptor);
if (methodGen == null) {
throw new MethodUnprofitableException(descriptor);
}
CFG cfg = getCFG(analysisCache, descriptor);
ValueNumberDataflow vnd = getValueNumberDataflow(analysisCache, descriptor);
UnconditionalValueDerefAnalysis analysis = new UnconditionalValueDerefAnalysis(getReverseDepthFirstSearch(analysisCache,
descriptor), getDepthFirstSearch(analysisCache, descriptor), cfg, getMethod(analysisCache, descriptor),
methodGen, vnd, getAssertionMethods(analysisCache, descriptor.getClassDescriptor()));
IsNullValueDataflow inv = getIsNullValueDataflow(analysisCache, descriptor);
// XXX: hack to clear derefs on not-null branches
analysis.clearDerefsOnNonNullBranches(inv);
TypeDataflow typeDataflow = getTypeDataflow(analysisCache, descriptor);
// XXX: type analysis is needed to resolve method calls for
// checking whether call targets unconditionally dereference parameters
analysis.setTypeDataflow(typeDataflow);
UnconditionalValueDerefDataflow dataflow = new UnconditionalValueDerefDataflow(cfg, analysis);
dataflow.execute();
if (ClassContext.DUMP_DATAFLOW_ANALYSIS) {
dataflow.dumpDataflow(analysis);
}
if (UnconditionalValueDerefAnalysis.DEBUG) {
ClassContext.dumpDataflowInformation(getMethod(analysisCache, descriptor), cfg, vnd, inv, dataflow, typeDataflow);
}
return dataflow;
}
}