soot.jimple.toolkits.ide.exampleproblems.IFDSLiveVariables Maven / Gradle / Ivy
package soot.jimple.toolkits.ide.exampleproblems;
/*-
* #%L
* Soot - a J*va Optimization Framework
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* Copyright (C) 1997 - 2013 Eric Bodden and others
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* it under the terms of the GNU Lesser General Public License as
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*
* This program 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 General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* .
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*/
import heros.DefaultSeeds;
import heros.FlowFunction;
import heros.FlowFunctions;
import heros.InterproceduralCFG;
import heros.flowfunc.Identity;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import soot.Local;
import soot.NullType;
import soot.Scene;
import soot.SootMethod;
import soot.Unit;
import soot.Value;
import soot.ValueBox;
import soot.jimple.InvokeExpr;
import soot.jimple.ReturnStmt;
import soot.jimple.Stmt;
import soot.jimple.internal.JimpleLocal;
import soot.jimple.toolkits.ide.DefaultJimpleIFDSTabulationProblem;
public class IFDSLiveVariables extends DefaultJimpleIFDSTabulationProblem> {
public IFDSLiveVariables(InterproceduralCFG icfg) {
super(icfg);
}
@Override
public FlowFunctions createFlowFunctionsFactory() {
return new FlowFunctions() {
@Override
public FlowFunction getNormalFlowFunction(Unit curr, Unit succ) {
if (curr.getUseAndDefBoxes().isEmpty()) {
return Identity.v();
}
final Stmt s = (Stmt) curr;
return new FlowFunction() {
public Set computeTargets(Value source) {
// kill defs
List defs = s.getDefBoxes();
if (!defs.isEmpty()) {
if (defs.get(0).getValue().equivTo(source)) {
return Collections.emptySet();
}
}
// gen uses out of zero value
if (source.equals(zeroValue())) {
Set liveVars = new HashSet();
for (ValueBox useBox : s.getUseBoxes()) {
Value value = useBox.getValue();
liveVars.add(value);
}
return liveVars;
}
// else just propagate
return Collections.singleton(source);
}
};
}
@Override
public FlowFunction getCallFlowFunction(Unit callStmt, final SootMethod destinationMethod) {
final Stmt s = (Stmt) callStmt;
return new FlowFunction() {
public Set computeTargets(Value source) {
if (!s.getDefBoxes().isEmpty()) {
Value callerSideReturnValue = s.getDefBoxes().get(0).getValue();
if (callerSideReturnValue.equivTo(source)) {
Set calleeSideReturnValues = new HashSet();
for (Unit calleeUnit : interproceduralCFG().getStartPointsOf(destinationMethod)) {
if (calleeUnit instanceof ReturnStmt) {
ReturnStmt returnStmt = (ReturnStmt) calleeUnit;
calleeSideReturnValues.add(returnStmt.getOp());
}
}
return calleeSideReturnValues;
}
}
// no return value, nothing to propagate
return Collections.emptySet();
}
};
}
@Override
public FlowFunction getReturnFlowFunction(final Unit callSite, SootMethod calleeMethod, final Unit exitStmt,
Unit returnSite) {
Stmt s = (Stmt) callSite;
InvokeExpr ie = s.getInvokeExpr();
final List callArgs = ie.getArgs();
final List paramLocals = new ArrayList();
for (int i = 0; i < calleeMethod.getParameterCount(); i++) {
paramLocals.add(calleeMethod.getActiveBody().getParameterLocal(i));
}
return new FlowFunction() {
public Set computeTargets(Value source) {
Set liveParamsAtCallee = new HashSet();
for (int i = 0; i < paramLocals.size(); i++) {
if (paramLocals.get(i).equivTo(source)) {
liveParamsAtCallee.add(callArgs.get(i));
}
}
return liveParamsAtCallee;
}
};
}
@Override
public FlowFunction getCallToReturnFlowFunction(Unit callSite, Unit returnSite) {
if (callSite.getUseAndDefBoxes().isEmpty()) {
return Identity.v();
}
final Stmt s = (Stmt) callSite;
return new FlowFunction() {
public Set computeTargets(Value source) {
// kill defs
List defs = s.getDefBoxes();
if (!defs.isEmpty()) {
if (defs.get(0).getValue().equivTo(source)) {
return Collections.emptySet();
}
}
// gen uses out of zero value
if (source.equals(zeroValue())) {
Set liveVars = new HashSet();
// only "gen" those values that are not parameter values;
// the latter are taken care of by the return-flow function
List args = s.getInvokeExpr().getArgs();
for (ValueBox useBox : s.getUseBoxes()) {
Value value = useBox.getValue();
if (!args.contains(value)) {
liveVars.add(value);
}
}
return liveVars;
}
// else just propagate
return Collections.singleton(source);
}
};
}
};
}
public Map> initialSeeds() {
return DefaultSeeds.make(interproceduralCFG().getStartPointsOf(Scene.v().getMainMethod()), zeroValue());
}
public Value createZeroValue() {
return new JimpleLocal("<>", NullType.v());
}
}