soot.toolkits.exceptions.TrapTransformer Maven / Gradle / Ivy
package soot.toolkits.exceptions;
/*-
* #%L
* Soot - a J*va Optimization Framework
* %%
* Copyright (C) 1997 - 2018 Raja Vallée-Rai and others
* %%
* This program 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 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
* .
* #L%
*/
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import soot.BodyTransformer;
import soot.Unit;
import soot.Value;
import soot.jimple.EnterMonitorStmt;
import soot.jimple.ExitMonitorStmt;
import soot.toolkits.graph.UnitGraph;
import soot.util.HashMultiMap;
import soot.util.MultiMap;
/**
* Common abstract base class for all body transformers that change the trap list to, e.g., minimize the trap list
*
* @author Steven Arzt
*
*/
public abstract class TrapTransformer extends BodyTransformer {
public Set getUnitsWithMonitor(UnitGraph ug) {
// Idea: Associate each unit with a set of monitors held at that
// statement
MultiMap unitMonitors = new HashMultiMap<>();
// Start at the heads of the unit graph
List workList = new ArrayList<>();
Set doneSet = new HashSet<>();
for (Unit head : ug.getHeads()) {
workList.add(head);
}
while (!workList.isEmpty()) {
Unit curUnit = workList.remove(0);
boolean hasChanged = false;
Value exitValue = null;
if (curUnit instanceof EnterMonitorStmt) {
// We enter a new monitor
EnterMonitorStmt ems = (EnterMonitorStmt) curUnit;
hasChanged = unitMonitors.put(curUnit, ems.getOp());
} else if (curUnit instanceof ExitMonitorStmt) {
// We leave a monitor
ExitMonitorStmt ems = (ExitMonitorStmt) curUnit;
exitValue = ems.getOp();
}
// Copy over the monitors from the predecessors
for (Unit pred : ug.getPredsOf(curUnit)) {
for (Value v : unitMonitors.get(pred)) {
if (v != exitValue) {
if (unitMonitors.put(curUnit, v)) {
hasChanged = true;
}
}
}
}
// Work on the successors
if (doneSet.add(curUnit) || hasChanged) {
workList.addAll(ug.getSuccsOf(curUnit));
}
}
return unitMonitors.keySet();
}
}