soot.toolkits.graph.ZonedBlockGraph Maven / Gradle / Ivy
package soot.toolkits.graph;
/*-
* #%L
* Soot - a J*va Optimization Framework
* %%
* Copyright (C) 1999 Patrice Pominville, Raja Vallee-Rai
* %%
* 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.Iterator;
import java.util.Set;
import soot.Body;
import soot.Trap;
import soot.Unit;
/**
* A CFG where the nodes are {@link Block} instances, and where exception boundaries are taken into account when finding the
* Blocks for the provided Body. Any {@link Unit} which is the first Unit to be convered by some exception
* handler will start a new Block, and any which is the last Unit to be covered a some exception
* handler, will end the block it is part of. These ``zones'', however, are not split up to indicate the possibility that an
* exception will lead to control exiting the zone before it is completed.
*
*/
public class ZonedBlockGraph extends BlockGraph {
/**
*
* Constructs a ZonedBlockGraph for the Units comprising the passed {@link Body}.
*
*
*
* Note that this constructor builds a {@link BriefUnitGraph} internally when splitting body's {@link Unit}s into
* {@link Block}s. Callers who need both a {@link BriefUnitGraph} and a {@link ZonedBlockGraph} can use the constructor
* taking the BriefUnitGraph as a parameter, as a minor optimization.
*
*
* @param body
* The Body for which to produce a ZonedBlockGraph.
*/
public ZonedBlockGraph(Body body) {
this(new BriefUnitGraph(body));
}
/**
* Constructs a ZonedBlockGraph corresponding to the Unit-level control flow represented by the passed
* {@link BriefUnitGraph}.
*
* @param unitGraph
* The BriefUnitGraph for which to produce a ZonedBlockGraph.
*/
public ZonedBlockGraph(BriefUnitGraph unitGraph) {
super(unitGraph);
soot.util.PhaseDumper.v().dumpGraph(this, mBody);
}
/**
*
* Utility method for computing the basic block leaders for a {@link Body}, given its {@link UnitGraph} (i.e., the
* instructions which begin new basic blocks).
*
*
*
* This implementation chooses as block leaders all the Units that {@link BlockGraph.computerLeaders()}, and adds:
*
*
*
* - The first Unit covered by each {@link Trap} (i.e., the Unit returned by
* {@link Trap.getBeginUnit()}.
*
* - The first Unit not covered by each {@link Trap} (i.e., the Unit returned by
* {@link Trap.getEndUnit()}.
*
*
*
*
* @param unitGraph
* is the Unit-level CFG which is to be split into basic blocks.
*
* @return the {@link Set} of {@link Unit}s in unitGraph which are block leaders.
*/
protected Set computeLeaders(UnitGraph unitGraph) {
Body body = unitGraph.getBody();
if (body != mBody) {
throw new RuntimeException("ZonedBlockGraph.computeLeaders() called with a UnitGraph that doesn't match its mBody.");
}
Set leaders = super.computeLeaders(unitGraph);
for (Iterator it = body.getTraps().iterator(); it.hasNext();) {
Trap trap = it.next();
leaders.add(trap.getBeginUnit());
leaders.add(trap.getEndUnit());
}
return leaders;
}
}