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clean up some IPCFG issues 

git-svn-id: https://wala.svn.sourceforge.net/svnroot/wala/trunk@1877 f5eafffb-2e1d-0410-98e4-8ec43c5233c4
This commit is contained in:
sjfink 2007-10-15 15:43:20 +00:00
parent 992238fc1c
commit cffb55a1e2
7 changed files with 778 additions and 1426 deletions
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577
com.ibm.wala.core/src/com/ibm/wala/cfg/TwoExitCFG.java
View File

@ -1,577 +0,0 @@
/*******************************************************************************
* Copyright (c) 2002 - 2006 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package com.ibm.wala.cfg;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import com.ibm.wala.classLoader.IMethod;
import com.ibm.wala.shrikeBT.IInstruction;
import com.ibm.wala.ssa.ISSABasicBlock;
import com.ibm.wala.ssa.SSAInstruction;
import com.ibm.wala.ssa.SSAPhiInstruction;
import com.ibm.wala.ssa.SSAPiInstruction;
import com.ibm.wala.ssa.SSAThrowInstruction;
import com.ibm.wala.util.IteratorPlusOne;
import com.ibm.wala.util.collections.EmptyIterator;
import com.ibm.wala.util.debug.Assertions;
import com.ibm.wala.util.debug.Trace;
import com.ibm.wala.util.debug.UnimplementedError;
import com.ibm.wala.util.graph.impl.NumberedNodeIterator;
import com.ibm.wala.util.intset.BitVector;
import com.ibm.wala.util.intset.FixedSizeBitVector;
import com.ibm.wala.util.intset.IntSet;
/**
*
* This provides a view of a control flow graph with two exits, one for normal
* returns and one for exceptional exits.
*
* @author sfink
*/
public class TwoExitCFG implements ControlFlowGraph<ISSABasicBlock> {
/**
* DEBUG_LEVEL: 0 No output 1 Print some simple stats and warning information
* 2 Detailed debugging
*/
static final int DEBUG_LEVEL = 0;
/**
* A "normal" cfg with one exit node
*/
private final ControlFlowGraph<ISSABasicBlock> delegate;
/**
* A distinguished basic block representing the exceptional exit.
*/
private final ISSABasicBlock exceptionalExit = new ExceptionalExitBlock();
/**
* Numbers of the "normal" predecessors of the delegate's exit() node
*/
private FixedSizeBitVector normalPred;
/**
* Numbers of the "exceptional" predecessors of the delegate's exit() node
*/
private FixedSizeBitVector exceptionalPred;
/**
* Cached here for efficiency: the "number" of the delegate's exit() node
*/
private final int delegateExitNumber;
/**
* compute edges lazily
*/
private boolean edgesAreComputed = false;
/**
* @param delegate
* A "normal" cfg with one exit node
* @throws IllegalArgumentException if delegate is null
*/
public TwoExitCFG(ControlFlowGraph<ISSABasicBlock> delegate) {
if (delegate == null) {
throw new IllegalArgumentException("delegate is null");
}
if (Assertions.verifyAssertions) {
Assertions._assert(!(delegate instanceof TwoExitCFG), "bad recursion");
}
this.delegate = delegate;
this.delegateExitNumber = delegate.getNumber(delegate.exit());
}
private void ensureEdgesReady() {
if (!edgesAreComputed) {
computeEdges();
edgesAreComputed = true;
}
}
/**
* @param delegate
*/
private void computeEdges() {
normalPred = (delegate instanceof AbstractCFG) ? ((AbstractCFG) delegate).getNormalToExit() : new FixedSizeBitVector(delegate
.getMaxNumber() + 1);
exceptionalPred = (delegate instanceof AbstractCFG) ? ((AbstractCFG) delegate).getExceptionalToExit() : new FixedSizeBitVector(
delegate.getMaxNumber() + 1);
if (!(delegate instanceof AbstractCFG)) {
IInstruction[] instructions = delegate.getInstructions();
for (Iterator it = delegate.getPredNodes(delegate.exit()); it.hasNext();) {
ISSABasicBlock b = (ISSABasicBlock) it.next();
if (b.getLastInstructionIndex() >= 0) {
IInstruction last = instructions[b.getLastInstructionIndex()];
if (last != null && last.isPEI()) {
exceptionalPred.set(b.getNumber());
// occasionally for weird CFGs we may actually fall
// thru to the exit. TODO: perhaps enforce an invariant
// that all "normal" predecessors of exit end in return.
if (!(last instanceof SSAThrowInstruction)) {
if (b.getLastInstructionIndex() == instructions.length - 1) {
normalPred.set(b.getNumber());
}
}
} else {
normalPred.set(b.getNumber());
}
}
}
}
}
public ISSABasicBlock entry() {
return delegate.entry();
}
public ISSABasicBlock exit() throws UnsupportedOperationException {
throw new UnsupportedOperationException("don't call this");
}
public BitVector getCatchBlocks() {
return delegate.getCatchBlocks();
}
public ISSABasicBlock getBlockForInstruction(int index) {
return delegate.getBlockForInstruction(index);
}
public IInstruction[] getInstructions() {
return delegate.getInstructions();
}
public int getProgramCounter(int index) {
return delegate.getProgramCounter(index);
}
/*
* @see com.ibm.wala.util.graph.Graph#removeNodeAndEdges(java.lang.Object)
*/
public void removeNodeAndEdges(ISSABasicBlock N) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
public int getNumber(ISSABasicBlock N) {
if (N == null) {
throw new IllegalArgumentException("N is null");
}
if (N.equals(exceptionalExit)) {
return getMaxNumber();
} else {
return delegate.getNumber(N);
}
}
/*
* @see com.ibm.wala.util.graph.NumberedNodeManager#getNode(int)
*/
public ISSABasicBlock getNode(int number) {
return (number == getMaxNumber()) ? exceptionalExit : delegate.getNode(number);
}
/*
* @see com.ibm.wala.util.graph.NumberedNodeManager#getMaxNumber()
*/
public int getMaxNumber() {
return delegate.getMaxNumber() + 1;
}
/*
* @see com.ibm.wala.util.graph.NodeManager#iterateNodes()
*/
public Iterator<ISSABasicBlock> iterator() {
return IteratorPlusOne.make(delegate.iterator(), exceptionalExit);
}
/*
* @see com.ibm.wala.util.graph.NodeManager#getNumberOfNodes()
*/
public int getNumberOfNodes() {
return delegate.getNumberOfNodes() + 1;
}
/*
* @see com.ibm.wala.util.graph.NodeManager#addNode(java.lang.Object)
*/
public void addNode(ISSABasicBlock n) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
/*
* @see com.ibm.wala.util.graph.NodeManager#removeNode(java.lang.Object)
*/
public void removeNode(ISSABasicBlock n) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
/*
* @see com.ibm.wala.util.graph.NodeManager#containsNode(java.lang.Object)
*/
public boolean containsNode(ISSABasicBlock N) {
return delegate.containsNode(N) || N.equals(exceptionalExit);
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#getPredNodes(java.lang.Object)
*/
public Iterator<? extends ISSABasicBlock> getPredNodes(ISSABasicBlock N) {
if (N == null) {
throw new IllegalArgumentException("N is null");
}
if (N.equals(exceptionalExit)) {
return delegate.getExceptionalPredecessors(delegate.exit()).iterator();
} else if (N.equals(delegate.exit())) {
return delegate.getNormalPredecessors(delegate.exit()).iterator();
} else {
return delegate.getPredNodes(N);
}
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#getPredNodeCount(java.lang.Object)
*/
public int getPredNodeCount(ISSABasicBlock N) {
if (N == null) {
throw new IllegalArgumentException("N is null");
}
ensureEdgesReady();
if (N.equals(delegate.exit())) {
return normalPred.populationCount();
} else if (N.equals(exceptionalExit)) {
return exceptionalPred.populationCount();
} else {
return delegate.getPredNodeCount(N);
}
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#getSuccNodes(java.lang.Object)
*/
public Iterator<? extends ISSABasicBlock> getSuccNodes(ISSABasicBlock N) {
if (N == null) {
throw new IllegalArgumentException("N is null");
}
if (DEBUG_LEVEL > 1) {
Trace.println("TwoExitCFG: getSuccNodes " + N);
}
ensureEdgesReady();
ISSABasicBlock bb = N;
if (N.equals(exceptionalExit)) {
return EmptyIterator.instance();
} else if (exceptionalPred.get(bb.getNumber())) {
if (normalPred.get(bb.getNumber())) {
return IteratorPlusOne.make(delegate.getSuccNodes(N), exceptionalExit);
} else {
return new SubstitutionIterator(delegate.getSuccNodes(N));
}
} else {
return delegate.getSuccNodes(N);
}
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#getSuccNodeCount(java.lang.Object)
*/
public int getSuccNodeCount(ISSABasicBlock N) {
if (N == null) {
throw new IllegalArgumentException("N is null");
}
if (N.equals(exceptionalExit)) {
return 0;
} else {
ensureEdgesReady();
int result = delegate.getSuccNodeCount(N);
ISSABasicBlock bb = N;
if (exceptionalPred.get(bb.getNumber()) && normalPred.get(bb.getNumber())) {
result++;
}
return result;
}
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#addEdge(java.lang.Object,
* java.lang.Object)
*/
public void addEdge(ISSABasicBlock src, ISSABasicBlock dst) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
public void removeEdge(ISSABasicBlock src, ISSABasicBlock dst) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
public boolean hasEdge(ISSABasicBlock src, ISSABasicBlock dst) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
public void removeAllIncidentEdges(ISSABasicBlock node) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
/**
* An additional basic block to model exceptional exits
*/
public final class ExceptionalExitBlock implements ISSABasicBlock {
public ControlFlowGraph getDelegate() {
return delegate;
}
/*
* @see com.ibm.wala.cfg.ISSABasicBlock#getFirstInstructionIndex()
*/
public int getFirstInstructionIndex() {
Assertions.UNREACHABLE();
return 0;
}
/*
* @see com.ibm.wala.cfg.ISSABasicBlock#getLastInstructionIndex()
*/
public int getLastInstructionIndex() {
return -2;
}
/*
* @see com.ibm.wala.cfg.ISSABasicBlock#isCatchBlock()
*/
public boolean isCatchBlock() {
Assertions.UNREACHABLE();
return false;
}
/*
* @see com.ibm.wala.cfg.ISSABasicBlock#isExitBlock()
*/
public boolean isExitBlock() {
return true;
}
/*
* @see com.ibm.wala.cfg.ISSABasicBlock#isEntryBlock()
*/
public boolean isEntryBlock() {
return false;
}
/*
* @see com.ibm.wala.cfg.ISSABasicBlock#getMethod()
*/
public IMethod getMethod() {
return delegate.getMethod();
}
/*
* @see com.ibm.wala.util.graph.INodeWithNumber#getGraphNodeId()
*/
public int getGraphNodeId() {
Assertions.UNREACHABLE();
return 0;
}
/*
* @see com.ibm.wala.util.graph.INodeWithNumber#setGraphNodeId(int)
*/
public void setGraphNodeId(int number) {
Assertions.UNREACHABLE();
}
/*
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object arg0) {
if (arg0 instanceof ExceptionalExitBlock) {
ExceptionalExitBlock other = (ExceptionalExitBlock) arg0;
return delegate.exit().equals(other.getDelegate().exit());
} else {
return false;
}
}
@Override
public int hashCode() {
return delegate.exit().hashCode() * 8467;
}
@Override
public String toString() {
return "Exceptional Exit[ " + getMethod() + "]";
}
/*
* @see com.ibm.wala.cfg.ISSABasicBlock#getNumber()
*/
public int getNumber() {
return getMaxNumber();
}
public Iterator<SSAPhiInstruction> iteratePhis() {
return EmptyIterator.instance();
}
public Iterator<SSAPiInstruction> iteratePis() {
return EmptyIterator.instance();
}
public Iterator<IInstruction> iterator() {
return EmptyIterator.instance();
}
public SSAInstruction getLastInstruction() {
Assertions.UNREACHABLE();
return null;
}
}
/*
* @see com.ibm.wala.cfg.ControlFlowGraph#getMethod()
*/
public IMethod getMethod() {
return delegate.getMethod();
}
/**
* An iterator that substitutes exceptionalExit for exit()
*/
private class SubstitutionIterator implements Iterator<ISSABasicBlock> {
private final Iterator it;
SubstitutionIterator(Iterator it) {
this.it = it;
}
public void remove() {
Assertions.UNREACHABLE();
}
public boolean hasNext() {
return it.hasNext();
}
public ISSABasicBlock next() {
ISSABasicBlock n = (ISSABasicBlock) it.next();
if (n.getNumber() == delegateExitNumber) {
return exceptionalExit;
} else {
return n;
}
}
}
/*
* @see com.ibm.wala.cfg.ControlFlowGraph#getExceptionalSuccessors(com.ibm.wala.cfg.ISSABasicBlock)
*/
public List<ISSABasicBlock> getExceptionalSuccessors(ISSABasicBlock b) {
if (b == null) {
throw new IllegalArgumentException("b is null");
}
if (b.equals(exceptionalExit)) {
return Collections.emptyList();
} else {
List<ISSABasicBlock> c = new ArrayList<ISSABasicBlock>(getSuccNodeCount(b));
for (Iterator<ISSABasicBlock> it = delegate.getExceptionalSuccessors(b).iterator(); it.hasNext(); ) {
ISSABasicBlock o = it.next();
if (o.equals(delegate.exit())) {
c.add(exceptionalExit);
} else {
c.add(o);
}
}
if (DEBUG_LEVEL > 1) {
Trace.println("Used delegate " + delegate.getClass());
Trace.println("Exceptional succ of " + b + " " + c);
}
return c;
}
}
/*
* @see com.ibm.wala.cfg.ControlFlowGraph#getNormalSuccessors(com.ibm.wala.cfg.ISSABasicBlock)
*/
public Collection<ISSABasicBlock> getNormalSuccessors(ISSABasicBlock b) {
if (b == null) {
throw new IllegalArgumentException("b is null");
}
if (b.equals(exceptionalExit)) {
return Collections.emptySet();
} else {
return delegate.getNormalSuccessors(b);
}
}
/**
* @return A distinguished basic block representing the normal exit
*/
public ISSABasicBlock getNormalExit() {
return delegate.exit();
}
/**
* @return A distinguished basic block representing the exceptional exit
*/
public ISSABasicBlock getExceptionalExit() {
return exceptionalExit;
}
@Override
public String toString() {
StringBuffer result = new StringBuffer("Two-Exit CFG");
result.append("\ndelegate\n" + delegate);
return result.toString();
}
/*
* @see com.ibm.wala.util.graph.NumberedNodeManager#iterateNodes(com.ibm.wala.util.intset.IntSet)
*/
public Iterator<ISSABasicBlock> iterateNodes(IntSet s) {
return new NumberedNodeIterator<ISSABasicBlock>(s, this);
}
public void removeIncomingEdges(ISSABasicBlock node) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
public void removeOutgoingEdges(ISSABasicBlock node) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
public Collection<ISSABasicBlock> getExceptionalPredecessors(ISSABasicBlock b) throws UnimplementedError {
Assertions.UNREACHABLE();
return null;
}
public Collection<ISSABasicBlock> getNormalPredecessors(ISSABasicBlock b) throws UnimplementedError {
Assertions.UNREACHABLE();
return null;
}
public IntSet getSuccNodeNumbers(ISSABasicBlock node) throws UnimplementedError {
Assertions.UNREACHABLE();
return null;
}
public IntSet getPredNodeNumbers(ISSABasicBlock node) throws UnimplementedError {
Assertions.UNREACHABLE();
return null;
}
public ControlFlowGraph getDelegate() {
return delegate;
}
}

52
com.ibm.wala.core/src/com/ibm/wala/dataflow/IFDS/PartiallyCollapsedSupergraph.java
View File

@ -19,7 +19,6 @@ import java.util.Set;
import com.ibm.wala.cfg.ControlFlowGraph;
import com.ibm.wala.cfg.IBasicBlock;
import com.ibm.wala.cfg.TwoExitCFG;
import com.ibm.wala.ipa.callgraph.CGNode;
import com.ibm.wala.ipa.callgraph.CallGraph;
import com.ibm.wala.ipa.cfg.BasicBlockInContext;
@ -131,8 +130,7 @@ public class PartiallyCollapsedSupergraph extends AbstractGraph<Object> implemen
}
}
this.noCollapse = noCollapse;
this.partialIPFG = new InterproceduralCFG(cg, new Filtersection<CGNode>(relevant, new CollectionFilter<CGNode>(noCollapse)),
true);
this.partialIPFG = new InterproceduralCFG(cg, new Filtersection<CGNode>(relevant, new CollectionFilter<CGNode>(noCollapse)));
if (DEBUG_LEVEL > 0) {
Trace.println("IPFG \n" + partialIPFG.toString());
}
@ -186,13 +184,7 @@ public class PartiallyCollapsedSupergraph extends AbstractGraph<Object> implemen
public Object[] getExitsForProcedure(CGNode node) {
if (noCollapse.contains(node)) {
ControlFlowGraph<ISSABasicBlock> cfg = partialIPFG.getCFG(node);
if (cfg instanceof TwoExitCFG) {
ISSABasicBlock o1 = ((TwoExitCFG) cfg).getNormalExit();
ISSABasicBlock o2 = ((TwoExitCFG) cfg).getExceptionalExit();
return new Object[] { new BasicBlockInContext(node, o1), new BasicBlockInContext(node, o2) };
} else {
return new Object[] { new BasicBlockInContext(node, cfg.exit()) };
}
return new Object[] { new BasicBlockInContext<ISSABasicBlock>(node, cfg.exit()) };
} else {
return new Object[] { nodeManager.getCollapsedExit(node) };
}
@ -251,9 +243,10 @@ public class PartiallyCollapsedSupergraph extends AbstractGraph<Object> implemen
}
}
@SuppressWarnings("unchecked")
public Iterator<? extends Object> getCallSites(Object object) {
if (object instanceof BasicBlockInContext) {
return partialIPFG.getCallSites((BasicBlockInContext) object);
return partialIPFG.getCallSites((BasicBlockInContext<ISSABasicBlock>) object);
} else {
CGNode n = nodeManager.getProcOfCollapsedNode(object);
return new NonNullSingletonIterator<CollapsedNode>(nodeManager.getCollapsedEntry(n));
@ -334,35 +327,19 @@ public class PartiallyCollapsedSupergraph extends AbstractGraph<Object> implemen
if (noCollapse.contains(outNode)) {
ControlFlowGraph<ISSABasicBlock> cfg = partialIPFG.getCFG(outNode);
// add an edge to the entry block
BasicBlockInContext entry = new BasicBlockInContext(outNode, cfg.entry());
BasicBlockInContext<ISSABasicBlock> entry = new BasicBlockInContext<ISSABasicBlock>(outNode, cfg.entry());
Set<Object> incoming = MapUtil.findOrCreateSet(incomingTransverseEdges, entry);
incoming.add(n);
Set<Object> outgoing = MapUtil.findOrCreateSet(outgoingTransverseEdges, n);
outgoing.add(entry);
// add the edge representing the return from the call.
if (cfg instanceof TwoExitCFG) {
TwoExitCFG t2 = (TwoExitCFG) cfg;
BasicBlockInContext exit = new BasicBlockInContext(outNode, t2.getNormalExit());
Object retSite = nodeManager.getCollapsedExit(node);
incoming = MapUtil.findOrCreateSet(incomingTransverseEdges, retSite);
incoming.add(exit);
outgoing = MapUtil.findOrCreateSet(outgoingTransverseEdges, exit);
outgoing.add(retSite);
exit = new BasicBlockInContext(outNode, t2.getExceptionalExit());
incoming.add(exit);
outgoing = MapUtil.findOrCreateSet(outgoingTransverseEdges, exit);
outgoing.add(retSite);
} else {
IBasicBlock exit = cfg.exit();
Object retSite = nodeManager.getCollapsedExit(node);
incoming = MapUtil.findOrCreateSet(incomingTransverseEdges, retSite);
incoming.add(exit);
outgoing = MapUtil.findOrCreateSet(outgoingTransverseEdges, exit);
outgoing.add(retSite);
}
IBasicBlock exit = cfg.exit();
Object retSite = nodeManager.getCollapsedExit(node);
incoming = MapUtil.findOrCreateSet(incomingTransverseEdges, retSite);
incoming.add(exit);
outgoing = MapUtil.findOrCreateSet(outgoingTransverseEdges, exit);
outgoing.add(retSite);
}
}
}
@ -840,11 +817,7 @@ public class PartiallyCollapsedSupergraph extends AbstractGraph<Object> implemen
if (noCollapse.contains(n)) {
// p is cg node which is expanded in the IPFG
ControlFlowGraph cfg = partialIPFG.getCFG(n);
if (cfg instanceof TwoExitCFG) {
return ((TwoExitCFG) cfg).getNormalExit();
} else {
return cfg.exit();
}
return cfg.exit();
} else {
// p is a collapsed node, for which all blocks map to the node itself;
return nodeManager.getCollapsedExit(n);
@ -854,6 +827,7 @@ public class PartiallyCollapsedSupergraph extends AbstractGraph<Object> implemen
/*
* @see com.ibm.wala.dataflow.IFDS.ISupergraph#isReturn(java.lang.Object)
*/
@SuppressWarnings("unchecked")
public boolean isReturn(Object object) {
if (object instanceof BasicBlockInContext) {
return partialIPFG.isReturn((BasicBlockInContext) object);

18
com.ibm.wala.core/src/com/ibm/wala/ipa/callgraph/CGNode.java
View File

@ -12,13 +12,11 @@ package com.ibm.wala.ipa.callgraph;
import java.util.Iterator;
import com.ibm.wala.cfg.ControlFlowGraph;
import com.ibm.wala.classLoader.CallSiteReference;
import com.ibm.wala.classLoader.IMethod;
import com.ibm.wala.classLoader.NewSiteReference;
import com.ibm.wala.ssa.DefUse;
import com.ibm.wala.ssa.IR;
import com.ibm.wala.ssa.ISSABasicBlock;
import com.ibm.wala.util.graph.INodeWithNumber;
/**
@ -58,17 +56,6 @@ public interface CGNode extends INodeWithNumber, ContextItem {
*/
@Deprecated
public boolean addTarget(CallSiteReference site, CGNode target);
// /**
// * @return the number of nodes that the call site current may resolve
// * to
// */
// public int getNumberOfTargets(CallSiteReference site);
// /**
// * @return the call graph in which this node dwells
// */
// public CallGraph getCallGraph();
/**
* @return the "default" IR for this node used by the governing call graph
@ -80,11 +67,6 @@ public interface CGNode extends INodeWithNumber, ContextItem {
*/
public DefUse getDU();
/**
* @return a CFG that represents the node, or null if it's an unmodelled native method
*/
public ControlFlowGraph<ISSABasicBlock> getCFG();
/**
* @return an Iterator of the types that may be allocated by a given
* method in a given context.

694
com.ibm.wala.core/src/com/ibm/wala/ipa/cfg/AbstractInterproceduralCFG.java Normal file
View File

@ -0,0 +1,694 @@
/*******************************************************************************
* Copyright (c) 2002 - 2006 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package com.ibm.wala.ipa.cfg;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import com.ibm.wala.cfg.ControlFlowGraph;
import com.ibm.wala.cfg.IBasicBlock;
import com.ibm.wala.classLoader.CallSiteReference;
import com.ibm.wala.ipa.callgraph.CGNode;
import com.ibm.wala.ipa.callgraph.CallGraph;
import com.ibm.wala.shrikeBT.IInstruction;
import com.ibm.wala.shrikeBT.IInvokeInstruction;
import com.ibm.wala.shrikeBT.InvokeInstruction;
import com.ibm.wala.ssa.ISSABasicBlock;
import com.ibm.wala.types.ClassLoaderReference;
import com.ibm.wala.types.MethodReference;
import com.ibm.wala.util.Function;
import com.ibm.wala.util.IndiscriminateFilter;
import com.ibm.wala.util.MapIterator;
import com.ibm.wala.util.collections.Filter;
import com.ibm.wala.util.collections.FilterIterator;
import com.ibm.wala.util.collections.HashSetFactory;
import com.ibm.wala.util.debug.Assertions;
import com.ibm.wala.util.debug.Trace;
import com.ibm.wala.util.debug.UnimplementedError;
import com.ibm.wala.util.graph.GraphIntegrity;
import com.ibm.wala.util.graph.NumberedGraph;
import com.ibm.wala.util.graph.GraphIntegrity.UnsoundGraphException;
import com.ibm.wala.util.graph.impl.SlowSparseNumberedGraph;
import com.ibm.wala.util.intset.BitVector;
import com.ibm.wala.util.intset.IntSet;
import com.ibm.wala.util.perf.EngineTimings;
/**
*
* Interprocedural control-flow graph.
*
* TODO: think about a better implementation; perhaps a lazy view of the
* constituent CFGs Lots of ways this can be optimized?
*
* @author sfink
* @author Julian Dolby
*/
public abstract class AbstractInterproceduralCFG<T extends ISSABasicBlock> implements NumberedGraph<BasicBlockInContext> {
private static final int DEBUG_LEVEL = 0;
/**
* Should the graph include call-to-return edges?
*/
private final static boolean CALL_TO_RETURN_EDGES = true;
/**
* Graph implementation we delegate to.
*/
final private NumberedGraph<BasicBlockInContext> G = new SlowSparseNumberedGraph<BasicBlockInContext>(2);
/**
* Governing call graph
*/
private final CallGraph cg;
/**
* Filter that determines relevant call graph nodes
*/
private final Filter<CGNode> relevant;
/**
* a cache: for each node (Basic Block), does that block end in a call?
*/
private final BitVector hasCallVector = new BitVector();
protected abstract ControlFlowGraph<T> getCFG(CGNode n);
/**
* Build an Interprocedural CFG from a call graph. This version defaults to
* using whatever CFGs the call graph provides by default, and includes all
* nodes in the call graph.
*
* @param CG
* the call graph
*/
@SuppressWarnings("unchecked")
public AbstractInterproceduralCFG(CallGraph CG) {
this(CG, IndiscriminateFilter.singleton());
}
/**
* Build an Interprocedural CFG from a call graph.
*
* @param CG
* the call graph
* @param relevant
* a filter which accepts those call graph nodes which should be
* included in the I-CFG. Other nodes are ignored.
*/
public AbstractInterproceduralCFG(CallGraph CG, Filter<CGNode> relevant) {
EngineTimings.startVirtual("InterproceduralCFG.<init>");
this.cg = CG;
this.relevant = relevant;
// create nodes for IPCFG
createNodes();
// create edges for IPCFG
createEdges();
if (DEBUG_LEVEL > 1) {
try {
GraphIntegrity.check(this);
} catch (UnsoundGraphException e) {
e.printStackTrace();
Assertions.UNREACHABLE();
}
}
EngineTimings.finishVirtual("InterproceduralCFG.<init>");
}
/**
* create the edges that define this graph.
*/
private void createEdges() {
for (Iterator ns = cg.iterator(); ns.hasNext();) {
CGNode n = (CGNode) ns.next();
if (relevant.accepts(n)) {
// retrieve a cfg for node n.
ControlFlowGraph<T> cfg = getCFG(n);
if (cfg == null) {
// n is an unmodelled native method
continue;
}
IInstruction[] instrs = cfg.getInstructions();
// create edges for node n.
for (Iterator<T> bbs = cfg.iterator(); bbs.hasNext();) {
T bb = bbs.next();
// entry node gets edges from callers
if (bb == cfg.entry()) {
addEdgesToEntryBlock(n, bb);
}
// other instructions get edges from predecessors,
// with special handling for calls.
else {
addEdgesToNonEntryBlock(n, cfg, instrs, bb);
}
}
}
}
}
/**
* create the nodes. side effect: populates the hasCallVector
*/
private void createNodes() {
for (Iterator ns = cg.iterator(); ns.hasNext();) {
CGNode n = (CGNode) ns.next();
if (relevant.accepts(n)) {
if (DEBUG_LEVEL > 0) {
Trace.println("Found a relevant node: " + n);
}
// retrieve a cfg for node n.
ControlFlowGraph<? extends T> cfg = getCFG(n);
if (cfg != null) {
// create a node for each basic block.
addNodeForEachBasicBlock(cfg, n);
}
}
}
}
/**
* Add edges to the IPCFG for the incoming edges incident on a basic block bb
*
* @param n
* a call graph node
* @param cfg
* the CFG for n
* @param instrs
* the instructions for node n
* @param bb
* a basic block in the CFG
*/
private void addEdgesToNonEntryBlock(CGNode n, ControlFlowGraph<T> cfg, IInstruction[] instrs, T bb) {
if (DEBUG_LEVEL > 0) {
Trace.println("addEdgesForNonEntryBlock: " + bb);
Trace.println("cfg class: " + cfg.getClass());
Trace.println("nPred: " + cfg.getPredNodeCount(bb));
}
for (Iterator<? extends T> ps = cfg.getPredNodes(bb); ps.hasNext();) {
T pb = ps.next();
if (DEBUG_LEVEL > 0) {
Trace.println("Consider previous block: " + pb);
}
if (pb.getLastInstructionIndex() < 0) {
// pb is the entry block for a cfg with
// no instructions.
BasicBlockInContext p = new BasicBlockInContext<T>(n, pb);
BasicBlockInContext b = new BasicBlockInContext<T>(n, bb);
G.addEdge(p, b);
continue;
}
int index = pb.getLastInstructionIndex();
IInstruction inst = instrs[index];
if (DEBUG_LEVEL > 0) {
Trace.println("Last instruction is : " + inst);
}
if (inst instanceof IInvokeInstruction) {
// a previous instruction is a call instruction. If necessary,
// add an edge from the exit() of each target of the call.
IInvokeInstruction call = (IInvokeInstruction) inst;
CallSiteReference site = makeCallSiteReference(n.getMethod().getDeclaringClass().getClassLoader().getReference(), cfg
.getProgramCounter(index), call);
if (DEBUG_LEVEL > 0) {
Trace.println("got Site: " + site);
}
boolean irrelevantTargets = false;
for (Iterator ts = cg.getPossibleTargets(n, site).iterator(); ts.hasNext();) {
CGNode tn = (CGNode) ts.next();
if (!relevant.accepts(tn)) {
if (DEBUG_LEVEL > 0) {
Trace.println("Irrelevant target: " + tn);
}
irrelevantTargets = true;
continue;
}
if (DEBUG_LEVEL > 0) {
Trace.println("Relevant target: " + tn);
}
// add an edge from tn exit to this node
ControlFlowGraph<? extends T> tcfg = getCFG(tn);
// tcfg might be null if tn is an unmodelled native method
if (tcfg != null) {
addEdgesFromExitToReturn(n, bb, tn, tcfg);
}
}
if (irrelevantTargets || CALL_TO_RETURN_EDGES) {
// at least one call target was ignored. So add a "normal" edge
// from the predecessor block to this block.
BasicBlockInContext p = new BasicBlockInContext<ISSABasicBlock>(n, pb);
BasicBlockInContext b = new BasicBlockInContext<ISSABasicBlock>(n, bb);
G.addEdge(p, b);
}
} else {
// previous instruction is not a call instruction.
BasicBlockInContext p = new BasicBlockInContext<ISSABasicBlock>(n, pb);
BasicBlockInContext b = new BasicBlockInContext<ISSABasicBlock>(n, bb);
if (Assertions.verifyAssertions) {
if (!G.containsNode(p) || !G.containsNode(b)) {
Assertions._assert(G.containsNode(p), "IPCFG does not contain " + p);
Assertions._assert(G.containsNode(b), "IPCFG does not contain " + b);
}
}
G.addEdge(p, b);
}
}
}
public static CallSiteReference makeCallSiteReference(ClassLoaderReference loader, int pc, IInvokeInstruction call)
throws IllegalArgumentException, IllegalArgumentException {
if (call == null) {
throw new IllegalArgumentException("call == null");
}
if (!(call instanceof com.ibm.wala.ssa.SSAInvokeInstruction) && !(call instanceof com.ibm.wala.shrikeBT.InvokeInstruction)) {
throw new IllegalArgumentException(
"(not ( call instanceof com.ibm.wala.ssa.SSAInvokeInstruction ) ) and (not ( call instanceof com.ibm.wala.shrikeBT.InvokeInstruction ) )");
}
CallSiteReference site = null;
if (call instanceof InvokeInstruction) {
InvokeInstruction c = (InvokeInstruction) call;
site = CallSiteReference.make(pc, MethodReference.findOrCreate(loader, c.getClassType(), c.getMethodName(), c
.getMethodSignature()), call.getInvocationCode());
} else {
com.ibm.wala.ssa.SSAInvokeInstruction c = (com.ibm.wala.ssa.SSAInvokeInstruction) call;
site = CallSiteReference.make(pc, c.getDeclaredTarget(), call.getInvocationCode());
}
return site;
}
/**
* Add an edge from the exit() block of a callee to a return site in the
* caller
*
* @param returnBlock
* the return site for a call
* @param targetCFG
* the called method
*/
private void addEdgesFromExitToReturn(CGNode caller, T returnBlock, CGNode target,
ControlFlowGraph<? extends T> targetCFG) {
T texit = targetCFG.exit();
BasicBlockInContext exit = new BasicBlockInContext<T>(target, texit);
BasicBlockInContext ret = new BasicBlockInContext<T>(caller, returnBlock);
if (Assertions.verifyAssertions) {
if (!G.containsNode(exit) || !G.containsNode(ret)) {
Assertions._assert(G.containsNode(exit), "IPCFG does not contain " + exit);
Assertions._assert(G.containsNode(ret), "IPCFG does not contain " + ret);
}
}
G.addEdge(exit, ret);
}
/**
* Add the incoming edges to the entry() block for a call graph node.
*
* @param n
* a node in the call graph
* @param bb
* the entry() block for n
*/
private void addEdgesToEntryBlock(CGNode n, T bb) {
if (DEBUG_LEVEL > 0) {
Trace.println("addEdgesToEntryBlock " + bb);
}
for (Iterator callers = cg.getPredNodes(n); callers.hasNext();) {
CGNode caller = (CGNode) callers.next();
if (DEBUG_LEVEL > 0) {
Trace.println("got caller " + caller);
}
if (relevant.accepts(caller)) {
if (DEBUG_LEVEL > 0) {
Trace.println("caller " + caller + "is relevant");
}
ControlFlowGraph<? extends T> ccfg = getCFG(caller);
IInstruction[] cinsts = ccfg.getInstructions();
if (DEBUG_LEVEL > 0) {
Trace.println("Visiting " + cinsts.length + " instructions");
}
for (int i = 0; i < cinsts.length; i++) {
if (cinsts[i] instanceof IInvokeInstruction) {
if (DEBUG_LEVEL > 0) {
Trace.println("Checking invokeinstruction: " + cinsts[i]);
}
IInvokeInstruction call = (IInvokeInstruction) cinsts[i];
CallSiteReference site = makeCallSiteReference(n.getMethod().getDeclaringClass().getClassLoader().getReference(), ccfg
.getProgramCounter(i), call);
if (cg.getPossibleTargets(caller, site).contains(n)) {
if (DEBUG_LEVEL > 0) {
Trace.println("Adding edge " + ccfg.getBlockForInstruction(i) + " to " + bb);
}
T callerBB = ccfg.getBlockForInstruction(i);
BasicBlockInContext b1 = new BasicBlockInContext<T>(caller, callerBB);
BasicBlockInContext b2 = new BasicBlockInContext<T>(n, bb);
G.addEdge(b1, b2);
}
}
}
}
}
}
/**
* Add a node to the IPCFG for each node in a CFG. side effect: populates the
* hasCallVector
*
* @param cfg
* a control-flow graph
*/
private void addNodeForEachBasicBlock(ControlFlowGraph<? extends T> cfg, CGNode N) {
for (Iterator<? extends T> bbs = cfg.iterator(); bbs.hasNext();) {
T bb = bbs.next();
if (DEBUG_LEVEL > 0) {
Trace.println("IPCFG Add basic block " + bb);
}
BasicBlockInContext b = new BasicBlockInContext<T>(N, bb);
G.addNode(b);
if (hasCall(b, cfg)) {
hasCallVector.set(getNumber(b));
}
}
}
/**
* @return the original CFG from whence B came
* @throws IllegalArgumentException
* if B == null
*/
public ControlFlowGraph<T> getCFG(BasicBlockInContext B) throws IllegalArgumentException {
if (B == null) {
throw new IllegalArgumentException("B == null");
}
return getCFG(getCGNode(B));
}
/**
* @return the original CGNode from whence B came
* @throws IllegalArgumentException
* if B == null
*/
public CGNode getCGNode(BasicBlockInContext B) throws IllegalArgumentException {
if (B == null) {
throw new IllegalArgumentException("B == null");
}
return B.getNode();
}
/*
* @see com.ibm.wala.util.graph.Graph#removeNodeAndEdges(com.ibm.wala.util.graph.Node)
*/
public void removeNodeAndEdges(BasicBlockInContext N) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
/*
* @see com.ibm.wala.util.graph.NodeManager#iterateNodes()
*/
public Iterator<BasicBlockInContext> iterator() {
return G.iterator();
}
/*
* @see com.ibm.wala.util.graph.NodeManager#getNumberOfNodes()
*/
public int getNumberOfNodes() {
return G.getNumberOfNodes();
}
/*
* @see com.ibm.wala.util.graph.NodeManager#addNode(com.ibm.wala.util.graph.Node)
*/
public void addNode(BasicBlockInContext n) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
/*
* @see com.ibm.wala.util.graph.NodeManager#removeNode(com.ibm.wala.util.graph.Node)
*/
public void removeNode(BasicBlockInContext n) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#getPredNodes(com.ibm.wala.util.graph.Node)
*/
public Iterator<? extends BasicBlockInContext> getPredNodes(BasicBlockInContext N) {
return G.getPredNodes(N);
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#getPredNodeCount(com.ibm.wala.util.graph.Node)
*/
public int getPredNodeCount(BasicBlockInContext N) {
return G.getPredNodeCount(N);
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#getSuccNodes(com.ibm.wala.util.graph.Node)
*/
public Iterator<? extends BasicBlockInContext> getSuccNodes(BasicBlockInContext N) {
return G.getSuccNodes(N);
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#getSuccNodeCount(com.ibm.wala.util.graph.Node)
*/
public int getSuccNodeCount(BasicBlockInContext N) {
return G.getSuccNodeCount(N);
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#addEdge(com.ibm.wala.util.graph.Node,
* com.ibm.wala.util.graph.Node)
*/
public void addEdge(BasicBlockInContext src, BasicBlockInContext dst) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
public void removeEdge(BasicBlockInContext src, BasicBlockInContext dst) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#removeEdges(com.ibm.wala.util.graph.Node)
*/
public void removeAllIncidentEdges(BasicBlockInContext node) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
@Override
public String toString() {
return G.toString();
}
/*
* @see com.ibm.wala.util.graph.Graph#containsNode(com.ibm.wala.util.graph.Node)
*/
public boolean containsNode(BasicBlockInContext N) {
return G.containsNode(N);
}
/**
* @param B
* @return true iff basic block B ends in a call instuction
*/
public boolean hasCall(BasicBlockInContext B) {
if (Assertions.verifyAssertions) {
if (!containsNode(B)) {
Assertions._assert(containsNode(B));
}
}
return hasCallVector.get(getNumber(B));
}
/**
* @return true iff basic block B ends in a call instuction
*/
private boolean hasCall(BasicBlockInContext B, ControlFlowGraph cfg) {
IInstruction[] statements = cfg.getInstructions();
int lastIndex = B.getLastInstructionIndex();
if (lastIndex >= 0) {
if (Assertions.verifyAssertions) {
if (statements.length <= lastIndex) {
System.err.println(statements.length);
System.err.println(cfg);
Assertions._assert(lastIndex < statements.length, "bad BB " + B + " and CFG for " + getCGNode(B));
}
}
IInstruction last = statements[lastIndex];
return (last instanceof IInvokeInstruction);
} else {
return false;
}
}
/**
* @param B
* @return the set of CGNodes that B may call, according to the governing call
* graph.
* @throws IllegalArgumentException
* if B is null
*/
public Set<CGNode> getCallTargets(BasicBlockInContext B) {
if (B == null) {
throw new IllegalArgumentException("B is null");
}
ControlFlowGraph cfg = getCFG(B);
return getCallTargets(B, cfg, getCGNode(B));
}
/**
* @return the set of CGNodes that B may call, according to the governing call
* graph.
*/
private Set<CGNode> getCallTargets(IBasicBlock B, ControlFlowGraph cfg, CGNode Bnode) {
IInstruction[] statements = cfg.getInstructions();
IInvokeInstruction call = (IInvokeInstruction) statements[B.getLastInstructionIndex()];
int pc = cfg.getProgramCounter(B.getLastInstructionIndex());
CallSiteReference site = makeCallSiteReference(B.getMethod().getDeclaringClass().getClassLoader().getReference(), pc, call);
HashSet<CGNode> result = HashSetFactory.make(cg.getNumberOfTargets(Bnode, site));
for (Iterator<CGNode> it = cg.getPossibleTargets(Bnode, site).iterator(); it.hasNext();) {
CGNode target = it.next();
result.add(target);
}
return result;
}
public void removeIncomingEdges(BasicBlockInContext node) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
public void removeOutgoingEdges(BasicBlockInContext node) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
public boolean hasEdge(BasicBlockInContext src, BasicBlockInContext dst) {
return G.hasEdge(src, dst);
}
public int getNumber(BasicBlockInContext N) {
return G.getNumber(N);
}
public BasicBlockInContext getNode(int number) throws UnimplementedError {
Assertions.UNREACHABLE();
return null;
}
public int getMaxNumber() {
return G.getMaxNumber();
}
public Iterator<BasicBlockInContext> iterateNodes(IntSet s) throws UnimplementedError {
Assertions.UNREACHABLE();
return null;
}
public IntSet getSuccNodeNumbers(BasicBlockInContext node) {
return G.getSuccNodeNumbers(node);
}
public IntSet getPredNodeNumbers(BasicBlockInContext node) {
return G.getPredNodeNumbers(node);
}
public BasicBlockInContext<T> getEntry(CGNode n) {
ControlFlowGraph<? extends T> cfg = getCFG(n);
T entry = cfg.entry();
return new BasicBlockInContext<T>(n, entry);
}
public BasicBlockInContext<T> getExit(CGNode n) {
ControlFlowGraph<? extends T> cfg = getCFG(n);
T entry = cfg.exit();
return new BasicBlockInContext<T>(n, entry);
}
/**
* @param bb
* node in the IPCFG that ends in a call
* @return the nodes that are return sites for this call.
* @throws IllegalArgumentException
* if bb is null
*/
public Iterator<BasicBlockInContext> getReturnSites(BasicBlockInContext bb) {
if (bb == null) {
throw new IllegalArgumentException("bb is null");
}
final CGNode node = bb.getNode();
// a successor node is a return site if it is in the same
// procedure, and is not the entry() node.
Filter isReturn = new Filter() {
public boolean accepts(Object o) {
if (Assertions.verifyAssertions) {
Assertions._assert(o instanceof BasicBlockInContext);
}
BasicBlockInContext other = (BasicBlockInContext) o;
return !other.isEntryBlock() && node.equals(other.getNode());
}
};
return new FilterIterator<BasicBlockInContext>(getSuccNodes(bb), isReturn);
}
public Iterator<BasicBlockInContext> getCallSites(BasicBlockInContext<T> bb) {
if (bb == null) {
throw new IllegalArgumentException("bb is null");
}
ControlFlowGraph<T> cfg = getCFG(bb);
Iterator<? extends T> it = cfg.getPredNodes(bb.getDelegate());
final CGNode node = bb.getNode();
Function<T, BasicBlockInContext<T>> toContext = new Function<T, BasicBlockInContext<T>>() {
public BasicBlockInContext<T> apply(T object) {
T b = object;
return new BasicBlockInContext<T>(node, b);
}
};
MapIterator<T, BasicBlockInContext<T>> m = new MapIterator<T, BasicBlockInContext<T>>(it, toContext);
return new FilterIterator<BasicBlockInContext>(m, isCall);
}
private final Filter isCall = new Filter() {
public boolean accepts(Object o) {
return hasCall((BasicBlockInContext) o);
}
};
public boolean isReturn(BasicBlockInContext<T> bb) throws IllegalArgumentException {
if (bb == null) {
throw new IllegalArgumentException("bb == null");
}
ControlFlowGraph<T> cfg = getCFG(bb);
for (Iterator<? extends T> it = cfg.getPredNodes(bb.getDelegate()); it.hasNext();) {
T b = it.next();
if (hasCall(new BasicBlockInContext<T>(bb.getNode(), b))) {
return true;
}
}
return false;
}
}

8
com.ibm.wala.core/src/com/ibm/wala/ipa/cfg/BasicBlockInContext.java
View File

@ -25,12 +25,12 @@ import com.ibm.wala.util.graph.impl.NodeWithNumber;
*
* @author sfink
*/
public final class BasicBlockInContext extends NodeWithNumber implements IBasicBlock {
private final ISSABasicBlock delegate;
public final class BasicBlockInContext<T extends ISSABasicBlock> extends NodeWithNumber implements IBasicBlock {
private final T delegate;
private final CGNode node;
public BasicBlockInContext(CGNode node, ISSABasicBlock bb) {
public BasicBlockInContext(CGNode node, T bb) {
this.delegate = bb;
this.node = node;
}
@ -106,7 +106,7 @@ public final class BasicBlockInContext extends NodeWithNumber implements IBasicB
return delegate.hashCode() + 229 * node.hashCode();
}
public ISSABasicBlock getDelegate() {
public T getDelegate() {
return delegate;
}

60
com.ibm.wala.core/src/com/ibm/wala/ipa/cfg/ExplodedInterproceduralCFG.java Normal file
View File

@ -0,0 +1,60 @@
/*******************************************************************************
* Copyright (c) 2002 - 2006 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package com.ibm.wala.ipa.cfg;
import com.ibm.wala.cfg.ControlFlowGraph;
import com.ibm.wala.ipa.callgraph.CGNode;
import com.ibm.wala.ipa.callgraph.CallGraph;
import com.ibm.wala.ssa.IR;
import com.ibm.wala.ssa.analysis.ExplodedControlFlowGraph;
import com.ibm.wala.ssa.analysis.ExplodedControlFlowGraph.ExplodedBasicBlock;
import com.ibm.wala.util.collections.Filtersection;
/**
*
* Interprocedural control-flow graph.
*
* TODO: think about a better implementation; perhaps a lazy view of the
* constituent CFGs Lots of ways this can be optimized?
*
* @author sfink
* @author Julian Dolby
*/
public class ExplodedInterproceduralCFG extends AbstractInterproceduralCFG<ExplodedBasicBlock> {
public static ExplodedInterproceduralCFG make(CallGraph CG) {
return new ExplodedInterproceduralCFG(CG);
}
private ExplodedInterproceduralCFG(CallGraph CG) {
super(CG);
}
public ExplodedInterproceduralCFG(CallGraph cg, Filtersection<CGNode> filtersection) {
super(cg,filtersection);
}
/**
* @return the cfg for n, or null if none found
* @throws IllegalArgumentException
* if n == null
*/
@Override
public ControlFlowGraph<ExplodedBasicBlock> getCFG(CGNode n) throws IllegalArgumentException {
if (n == null) {
throw new IllegalArgumentException("n == null");
}
IR ir = n.getIR();
return ExplodedControlFlowGraph.make(ir);
}
}

795
com.ibm.wala.core/src/com/ibm/wala/ipa/cfg/InterproceduralCFG.java
View File

@ -10,38 +10,11 @@
*******************************************************************************/
package com.ibm.wala.ipa.cfg;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import com.ibm.wala.cfg.ControlFlowGraph;
import com.ibm.wala.cfg.IBasicBlock;
import com.ibm.wala.cfg.TwoExitCFG;
import com.ibm.wala.classLoader.CallSiteReference;
import com.ibm.wala.ipa.callgraph.CGNode;
import com.ibm.wala.ipa.callgraph.CallGraph;
import com.ibm.wala.shrikeBT.IInstruction;
import com.ibm.wala.shrikeBT.IInvokeInstruction;
import com.ibm.wala.shrikeBT.InvokeInstruction;
import com.ibm.wala.ssa.ISSABasicBlock;
import com.ibm.wala.types.ClassLoaderReference;
import com.ibm.wala.types.MethodReference;
import com.ibm.wala.util.Function;
import com.ibm.wala.util.IndiscriminateFilter;
import com.ibm.wala.util.MapIterator;
import com.ibm.wala.util.collections.Filter;
import com.ibm.wala.util.collections.FilterIterator;
import com.ibm.wala.util.collections.HashSetFactory;
import com.ibm.wala.util.debug.Assertions;
import com.ibm.wala.util.debug.Trace;
import com.ibm.wala.util.debug.UnimplementedError;
import com.ibm.wala.util.graph.GraphIntegrity;
import com.ibm.wala.util.graph.NumberedGraph;
import com.ibm.wala.util.graph.GraphIntegrity.UnsoundGraphException;
import com.ibm.wala.util.graph.impl.SlowSparseNumberedGraph;
import com.ibm.wala.util.intset.BitVector;
import com.ibm.wala.util.intset.IntSet;
import com.ibm.wala.util.perf.EngineTimings;
import com.ibm.wala.util.collections.Filtersection;
/**
*
@ -53,141 +26,15 @@ import com.ibm.wala.util.perf.EngineTimings;
* @author sfink
* @author Julian Dolby
*/
public class InterproceduralCFG implements NumberedGraph<BasicBlockInContext> {
public class InterproceduralCFG extends AbstractInterproceduralCFG<ISSABasicBlock> {
private static final int DEBUG_LEVEL = 0;
/**
* Should the graph include call-to-return edges?
*/
private final static boolean CALL_TO_RETURN_EDGES = true;
/**
* Graph implementation we delegate to.
*/
final private NumberedGraph<BasicBlockInContext> G = new SlowSparseNumberedGraph<BasicBlockInContext>(2);
/**
* Governing call graph
*/
private final CallGraph cg;
/**
* Should we introduce a distinguished "exceptional exit" from each individual
* CFG?
*/
final private boolean partitionExits;
/**
* Filter that determines relevant call graph nodes
*/
private final Filter<CGNode> relevant;
/**
* a cache: for each node (Basic Block), does that block end in a call?
*/
private final BitVector hasCallVector = new BitVector();
/**
* Build an Interprocedural CFG from a call graph. This version defaults to
* using whatever CFGs the call graph provides by default, and includes all
* nodes in the call graph.
*
* @param CG
* the call graph
*/
@SuppressWarnings("unchecked")
public InterproceduralCFG(CallGraph CG) {
this(CG, IndiscriminateFilter.singleton(), false);
super(CG);
}
/**
* Build an Interprocedural CFG from a call graph.
*
* @param CG
* the call graph
* @param relevant
* a filter which accepts those call graph nodes which should be
* included in the I-CFG. Other nodes are ignored.
*/
public InterproceduralCFG(CallGraph CG, Filter<CGNode> relevant, boolean partitionExits) {
EngineTimings.startVirtual("InterproceduralCFG.<init>");
this.cg = CG;
this.relevant = relevant;
this.partitionExits = partitionExits;
// create nodes for IPCFG
createNodes();
// create edges for IPCFG
createEdges();
if (DEBUG_LEVEL > 1) {
try {
GraphIntegrity.check(this);
} catch (UnsoundGraphException e) {
e.printStackTrace();
Assertions.UNREACHABLE();
}
}
EngineTimings.finishVirtual("InterproceduralCFG.<init>");
}
/**
* create the edges that define this graph.
*/
private void createEdges() {
for (Iterator ns = cg.iterator(); ns.hasNext();) {
CGNode n = (CGNode) ns.next();
if (relevant.accepts(n)) {
// retrieve a cfg for node n.
ControlFlowGraph<ISSABasicBlock> cfg = n.getCFG();
if (cfg == null) {
// n is an unmodelled native method
continue;
}
if (partitionExits) {
cfg = new TwoExitCFG(cfg);
}
IInstruction[] instrs = cfg.getInstructions();
// create edges for node n.
for (Iterator bbs = cfg.iterator(); bbs.hasNext();) {
ISSABasicBlock bb = (ISSABasicBlock) bbs.next();
// entry node gets edges from callers
if (bb == cfg.entry()) {
addEdgesToEntryBlock(n, bb);
}
// other instructions get edges from predecessors,
// with special handling for calls.
else {
addEdgesToNonEntryBlock(n, cfg, instrs, bb);
}
}
}
}
}
/**
* create the nodes. side effect: populates the hasCallVector
*/
private void createNodes() {
for (Iterator ns = cg.iterator(); ns.hasNext();) {
CGNode n = (CGNode) ns.next();
if (relevant.accepts(n)) {
if (DEBUG_LEVEL > 0) {
Trace.println("Found a relevant node: " + n);
}
// retrieve a cfg for node n.
ControlFlowGraph<ISSABasicBlock> cfg = getCFG(n);
if (cfg != null) {
// create a node for each basic block.
addNodeForEachBasicBlock(cfg, n);
}
}
}
public InterproceduralCFG(CallGraph cg, Filtersection<CGNode> filtersection) {
super(cg,filtersection);
}
/**
@ -195,645 +42,17 @@ public class InterproceduralCFG implements NumberedGraph<BasicBlockInContext> {
* @throws IllegalArgumentException
* if n == null
*/
@Override
public ControlFlowGraph<ISSABasicBlock> getCFG(CGNode n) throws IllegalArgumentException {
if (n == null) {
throw new IllegalArgumentException("n == null");
}
ControlFlowGraph<ISSABasicBlock> cfg = n.getCFG();
ControlFlowGraph<ISSABasicBlock> cfg = n.getIR().getControlFlowGraph();
if (cfg == null) {
return null;
}
if (DEBUG_LEVEL > 1) {
// TODO: we NEED TO FIX synthetic methods to have
// meaningful IRs for flow-sensitive analysis
if (!n.getMethod().isSynthetic()) {
try {
GraphIntegrity.check(cfg);
} catch (UnsoundGraphException e) {
e.printStackTrace();
Assertions.UNREACHABLE();
}
}
}
if (partitionExits) {
cfg = new TwoExitCFG(cfg);
}
if (DEBUG_LEVEL > 1) {
// TODO: we NEED TO FIX synthetic methods to have
// meaningful IRs for flow-sensitive analysis
if (!n.getMethod().isSynthetic()) {
try {
GraphIntegrity.check(cfg);
} catch (UnsoundGraphException e) {
e.printStackTrace();
Assertions.UNREACHABLE();
}
}
}
return cfg;
}
/**
* Add edges to the IPCFG for the incoming edges incident on a basic block bb
*
* @param n
* a call graph node
* @param cfg
* the CFG for n
* @param instrs
* the instructions for node n
* @param bb
* a basic block in the CFG
*/
private void addEdgesToNonEntryBlock(CGNode n, ControlFlowGraph<ISSABasicBlock> cfg, IInstruction[] instrs, ISSABasicBlock bb) {
if (DEBUG_LEVEL > 0) {
Trace.println("addEdgesForNonEntryBlock: " + bb);
Trace.println("cfg class: " + cfg.getClass());
Trace.println("nPred: " + cfg.getPredNodeCount(bb));
}
for (Iterator ps = cfg.getPredNodes(bb); ps.hasNext();) {
ISSABasicBlock pb = (ISSABasicBlock) ps.next();
if (DEBUG_LEVEL > 0) {
Trace.println("Consider previous block: " + pb);
}
if (pb.getLastInstructionIndex() < 0) {
// pb is the entry block for a cfg with
// no instructions.
BasicBlockInContext p = new BasicBlockInContext(n, pb);
BasicBlockInContext b = new BasicBlockInContext(n, bb);
G.addEdge(p, b);
continue;
}
int index = pb.getLastInstructionIndex();
IInstruction inst = instrs[index];
if (DEBUG_LEVEL > 0) {
Trace.println("Last instruction is : " + inst);
}
if (inst instanceof IInvokeInstruction) {
// a previous instruction is a call instruction. If necessary,
// add an edge from the exit() of each target of the call.
IInvokeInstruction call = (IInvokeInstruction) inst;
CallSiteReference site = makeCallSiteReference(n.getMethod().getDeclaringClass().getClassLoader().getReference(), cfg
.getProgramCounter(index), call);
if (DEBUG_LEVEL > 0) {
Trace.println("got Site: " + site);
}
boolean irrelevantTargets = false;
for (Iterator ts = cg.getPossibleTargets(n, site).iterator(); ts.hasNext();) {
CGNode tn = (CGNode) ts.next();
if (!relevant.accepts(tn)) {
if (DEBUG_LEVEL > 0) {
Trace.println("Irrelevant target: " + tn);
}
irrelevantTargets = true;
continue;
}
if (DEBUG_LEVEL > 0) {
Trace.println("Relevant target: " + tn);
}
// add an edge from tn exit to this node
ControlFlowGraph<ISSABasicBlock> tcfg = tn.getCFG();
// tcfg might be null if tn is an unmodelled native method
if (tcfg != null) {
if (partitionExits) {
if (DEBUG_LEVEL > 0) {
Trace.println("normal? " + representsNormalReturn(cfg, bb, pb));
Trace.println("exceptional? " + representsExceptionalReturn(cfg, bb, pb));
}
if (!(tcfg instanceof TwoExitCFG)) {
tcfg = new TwoExitCFG(tcfg);
}
if (representsNormalReturn(cfg, bb, pb)) {
if (DEBUG_LEVEL > 0) {
Trace.println("representsNormalReturn: " + bb + " " + pb);
}
addEdgesFromNormalExitToReturn(n, bb, tn, (TwoExitCFG) tcfg);
}
if (representsExceptionalReturn(cfg, bb, pb)) {
if (DEBUG_LEVEL > 0) {
Trace.println("representsExceptionalReturn: " + bb + " " + pb);
}
addEdgesFromExceptionalExitToReturn(n, bb, tn, (TwoExitCFG) tcfg);
}
} else {
addEdgesFromExitToReturn(n, bb, tn, tcfg);
}
}
}
if (irrelevantTargets || CALL_TO_RETURN_EDGES) {
// at least one call target was ignored. So add a "normal" edge
// from the predecessor block to this block.
BasicBlockInContext p = new BasicBlockInContext(n, pb);
BasicBlockInContext b = new BasicBlockInContext(n, bb);
G.addEdge(p, b);
}
} else {
// previous instruction is not a call instruction.
BasicBlockInContext p = new BasicBlockInContext(n, pb);
BasicBlockInContext b = new BasicBlockInContext(n, bb);
if (Assertions.verifyAssertions) {
if (!G.containsNode(p) || !G.containsNode(b)) {
Assertions._assert(G.containsNode(p), "IPCFG does not contain " + p);
Assertions._assert(G.containsNode(b), "IPCFG does not contain " + b);
}
}
G.addEdge(p, b);
}
}
}
public static CallSiteReference makeCallSiteReference(ClassLoaderReference loader, int pc, IInvokeInstruction call)
throws IllegalArgumentException, IllegalArgumentException {
if (call == null) {
throw new IllegalArgumentException("call == null");
}
if (!(call instanceof com.ibm.wala.ssa.SSAInvokeInstruction) && !(call instanceof com.ibm.wala.shrikeBT.InvokeInstruction)) {
throw new IllegalArgumentException(
"(not ( call instanceof com.ibm.wala.ssa.SSAInvokeInstruction ) ) and (not ( call instanceof com.ibm.wala.shrikeBT.InvokeInstruction ) )");
}
CallSiteReference site = null;
if (call instanceof InvokeInstruction) {
InvokeInstruction c = (InvokeInstruction) call;
site = CallSiteReference.make(pc, MethodReference.findOrCreate(loader, c.getClassType(), c.getMethodName(), c
.getMethodSignature()), call.getInvocationCode());
} else {
com.ibm.wala.ssa.SSAInvokeInstruction c = (com.ibm.wala.ssa.SSAInvokeInstruction) call;
site = CallSiteReference.make(pc, c.getDeclaredTarget(), call.getInvocationCode());
}
return site;
}
/**
* Add an edge from the exceptional exit block of a callee to a return site in
* the caller
*
* @param returnBlock
* the return site for a call
* @param targetCFG
* the called method
*/
private void addEdgesFromExceptionalExitToReturn(CGNode caller, ISSABasicBlock returnBlock, CGNode target, TwoExitCFG targetCFG) {
ISSABasicBlock texit = targetCFG.getExceptionalExit();
BasicBlockInContext exit = new BasicBlockInContext(target, texit);
BasicBlockInContext ret = new BasicBlockInContext(caller, returnBlock);
if (Assertions.verifyAssertions) {
if (!G.containsNode(exit) || !G.containsNode(ret)) {
Assertions._assert(G.containsNode(exit), "IPCFG does not contain " + exit);
Assertions._assert(G.containsNode(ret), "IPCFG does not contain " + ret);
}
}
G.addEdge(exit, ret);
}
/**
* @param cfg
* the governing cfg
* @param ret
* a return site for the call
* @param call
* a basic block that ends in a call
* @return true iff bb is reached from pb by exceptional control flow
*/
private boolean representsExceptionalReturn(ControlFlowGraph<ISSABasicBlock> cfg, ISSABasicBlock ret, ISSABasicBlock call) {
for (Iterator it = cfg.getExceptionalSuccessors(call).iterator(); it.hasNext();) {
if (ret.equals(it.next())) {
return true;
}
}
return false;
}
/**
* Add an edge from the normal exit block of a callee to a return site in the
* caller
*
* @param returnBlock
* the return site for a call
* @param targetCFG
* the called method
*/
private void addEdgesFromNormalExitToReturn(CGNode caller, ISSABasicBlock returnBlock, CGNode target, TwoExitCFG targetCFG) {
ISSABasicBlock texit = targetCFG.getNormalExit();
BasicBlockInContext exit = new BasicBlockInContext(target, texit);
BasicBlockInContext ret = new BasicBlockInContext(caller, returnBlock);
if (Assertions.verifyAssertions) {
if (!G.containsNode(exit) || !G.containsNode(ret)) {
Assertions._assert(G.containsNode(exit), "IPCFG does not contain " + exit);
Assertions._assert(G.containsNode(ret), "IPCFG does not contain " + ret);
}
}
G.addEdge(exit, ret);
}
/**
* @param cfg
* the governing cfg
* @return true iff bb is reached from pb by a normal return flow
*/
private boolean representsNormalReturn(ControlFlowGraph<ISSABasicBlock> cfg, ISSABasicBlock ret, ISSABasicBlock call) {
for (Iterator it = cfg.getNormalSuccessors(call).iterator(); it.hasNext();) {
if (ret.equals(it.next())) {
return true;
}
}
return false;
}
/**
* Add an edge from the exit() block of a callee to a return site in the
* caller
*
* @param returnBlock
* the return site for a call
* @param targetCFG
* the called method
*/
private void addEdgesFromExitToReturn(CGNode caller, ISSABasicBlock returnBlock, CGNode target,
ControlFlowGraph<ISSABasicBlock> targetCFG) {
ISSABasicBlock texit = targetCFG.exit();
BasicBlockInContext exit = new BasicBlockInContext(target, texit);
BasicBlockInContext ret = new BasicBlockInContext(caller, returnBlock);
if (Assertions.verifyAssertions) {
if (!G.containsNode(exit) || !G.containsNode(ret)) {
Assertions._assert(G.containsNode(exit), "IPCFG does not contain " + exit);
Assertions._assert(G.containsNode(ret), "IPCFG does not contain " + ret);
}
}
G.addEdge(exit, ret);
}
/**
* Add the incoming edges to the entry() block for a call graph node.
*
* @param n
* a node in the call graph
* @param bb
* the entry() block for n
*/
private void addEdgesToEntryBlock(CGNode n, ISSABasicBlock bb) {
if (DEBUG_LEVEL > 0) {
Trace.println("addEdgesToEntryBlock " + bb);
}
for (Iterator callers = cg.getPredNodes(n); callers.hasNext();) {
CGNode caller = (CGNode) callers.next();
if (DEBUG_LEVEL > 0) {
Trace.println("got caller " + caller);
}
if (relevant.accepts(caller)) {
if (DEBUG_LEVEL > 0) {
Trace.println("caller " + caller + "is relevant");
}
ControlFlowGraph<ISSABasicBlock> ccfg = caller.getCFG();
IInstruction[] cinsts = ccfg.getInstructions();
if (DEBUG_LEVEL > 0) {
Trace.println("Visiting " + cinsts.length + " instructions");
}
for (int i = 0; i < cinsts.length; i++) {
if (cinsts[i] instanceof IInvokeInstruction) {
if (DEBUG_LEVEL > 0) {
Trace.println("Checking invokeinstruction: " + cinsts[i]);
}
IInvokeInstruction call = (IInvokeInstruction) cinsts[i];
CallSiteReference site = makeCallSiteReference(n.getMethod().getDeclaringClass().getClassLoader().getReference(), ccfg
.getProgramCounter(i), call);
if (cg.getPossibleTargets(caller, site).contains(n)) {
if (DEBUG_LEVEL > 0) {
Trace.println("Adding edge " + ccfg.getBlockForInstruction(i) + " to " + bb);
}
ISSABasicBlock callerBB = ccfg.getBlockForInstruction(i);
BasicBlockInContext b1 = new BasicBlockInContext(caller, callerBB);
BasicBlockInContext b2 = new BasicBlockInContext(n, bb);
G.addEdge(b1, b2);
}
}
}
}
}
}
/**
* Add a node to the IPCFG for each node in a CFG. side effect: populates the
* hasCallVector
*
* @param cfg
* a control-flow graph
*/
private void addNodeForEachBasicBlock(ControlFlowGraph<ISSABasicBlock> cfg, CGNode N) {
for (Iterator<ISSABasicBlock> bbs = cfg.iterator(); bbs.hasNext();) {
ISSABasicBlock bb = bbs.next();
if (DEBUG_LEVEL > 0) {
Trace.println("IPCFG Add basic block " + bb);
}
BasicBlockInContext b = new BasicBlockInContext(N, bb);
G.addNode(b);
if (hasCall(b, cfg)) {
hasCallVector.set(getNumber(b));
}
}
}
/**
* @return the original CFG from whence B came
* @throws IllegalArgumentException
* if B == null
*/
public ControlFlowGraph<ISSABasicBlock> getCFG(BasicBlockInContext B) throws IllegalArgumentException {
if (B == null) {
throw new IllegalArgumentException("B == null");
}
return getCFG(getCGNode(B));
}
/**
* @return the original CGNode from whence B came
* @throws IllegalArgumentException
* if B == null
*/
public CGNode getCGNode(BasicBlockInContext B) throws IllegalArgumentException {
if (B == null) {
throw new IllegalArgumentException("B == null");
}
return B.getNode();
}
/*
* @see com.ibm.wala.util.graph.Graph#removeNodeAndEdges(com.ibm.wala.util.graph.Node)
*/
public void removeNodeAndEdges(BasicBlockInContext N) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
/*
* @see com.ibm.wala.util.graph.NodeManager#iterateNodes()
*/
public Iterator<BasicBlockInContext> iterator() {
return G.iterator();
}
/*
* @see com.ibm.wala.util.graph.NodeManager#getNumberOfNodes()
*/
public int getNumberOfNodes() {
return G.getNumberOfNodes();
}
/*
* @see com.ibm.wala.util.graph.NodeManager#addNode(com.ibm.wala.util.graph.Node)
*/
public void addNode(BasicBlockInContext n) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
/*
* @see com.ibm.wala.util.graph.NodeManager#removeNode(com.ibm.wala.util.graph.Node)
*/
public void removeNode(BasicBlockInContext n) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#getPredNodes(com.ibm.wala.util.graph.Node)
*/
public Iterator<? extends BasicBlockInContext> getPredNodes(BasicBlockInContext N) {
return G.getPredNodes(N);
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#getPredNodeCount(com.ibm.wala.util.graph.Node)
*/
public int getPredNodeCount(BasicBlockInContext N) {
return G.getPredNodeCount(N);
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#getSuccNodes(com.ibm.wala.util.graph.Node)
*/
public Iterator<? extends BasicBlockInContext> getSuccNodes(BasicBlockInContext N) {
return G.getSuccNodes(N);
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#getSuccNodeCount(com.ibm.wala.util.graph.Node)
*/
public int getSuccNodeCount(BasicBlockInContext N) {
return G.getSuccNodeCount(N);
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#addEdge(com.ibm.wala.util.graph.Node,
* com.ibm.wala.util.graph.Node)
*/
public void addEdge(BasicBlockInContext src, BasicBlockInContext dst) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
public void removeEdge(BasicBlockInContext src, BasicBlockInContext dst) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
/*
* @see com.ibm.wala.util.graph.EdgeManager#removeEdges(com.ibm.wala.util.graph.Node)
*/
public void removeAllIncidentEdges(BasicBlockInContext node) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
@Override
public String toString() {
return G.toString();
}
/*
* @see com.ibm.wala.util.graph.Graph#containsNode(com.ibm.wala.util.graph.Node)
*/
public boolean containsNode(BasicBlockInContext N) {
return G.containsNode(N);
}
/**
* @param B
* @return true iff basic block B ends in a call instuction
*/
public boolean hasCall(BasicBlockInContext B) {
if (Assertions.verifyAssertions) {
if (!containsNode(B)) {
Assertions._assert(containsNode(B));
}
}
return hasCallVector.get(getNumber(B));
}
/**
* @return true iff basic block B ends in a call instuction
*/
private boolean hasCall(BasicBlockInContext B, ControlFlowGraph cfg) {
IInstruction[] statements = cfg.getInstructions();
int lastIndex = B.getLastInstructionIndex();
if (lastIndex >= 0) {
if (Assertions.verifyAssertions) {
if (statements.length <= lastIndex) {
System.err.println(statements.length);
System.err.println(cfg);
Assertions._assert(lastIndex < statements.length, "bad BB " + B + " and CFG for " + getCGNode(B));
}
}
IInstruction last = statements[lastIndex];
return (last instanceof IInvokeInstruction);
} else {
return false;
}
}
/**
* @param B
* @return the set of CGNodes that B may call, according to the governing call
* graph.
* @throws IllegalArgumentException
* if B is null
*/
public Set<CGNode> getCallTargets(BasicBlockInContext B) {
if (B == null) {
throw new IllegalArgumentException("B is null");
}
ControlFlowGraph cfg = getCFG(B);
return getCallTargets(B, cfg, getCGNode(B));
}
/**
* @return the set of CGNodes that B may call, according to the governing call
* graph.
*/
private Set<CGNode> getCallTargets(IBasicBlock B, ControlFlowGraph cfg, CGNode Bnode) {
IInstruction[] statements = cfg.getInstructions();
IInvokeInstruction call = (IInvokeInstruction) statements[B.getLastInstructionIndex()];
int pc = cfg.getProgramCounter(B.getLastInstructionIndex());
CallSiteReference site = makeCallSiteReference(B.getMethod().getDeclaringClass().getClassLoader().getReference(), pc, call);
HashSet<CGNode> result = HashSetFactory.make(cg.getNumberOfTargets(Bnode, site));
for (Iterator<CGNode> it = cg.getPossibleTargets(Bnode, site).iterator(); it.hasNext();) {
CGNode target = it.next();
result.add(target);
}
return result;
}
public void removeIncomingEdges(BasicBlockInContext node) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
public void removeOutgoingEdges(BasicBlockInContext node) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
public boolean hasEdge(BasicBlockInContext src, BasicBlockInContext dst) {
return G.hasEdge(src, dst);
}
public int getNumber(BasicBlockInContext N) {
return G.getNumber(N);
}
public BasicBlockInContext getNode(int number) throws UnimplementedError {
Assertions.UNREACHABLE();
return null;
}
public int getMaxNumber() {
return G.getMaxNumber();
}
public Iterator<BasicBlockInContext> iterateNodes(IntSet s) throws UnimplementedError {
Assertions.UNREACHABLE();
return null;
}
public IntSet getSuccNodeNumbers(BasicBlockInContext node) {
return G.getSuccNodeNumbers(node);
}
public IntSet getPredNodeNumbers(BasicBlockInContext node) {
return G.getPredNodeNumbers(node);
}
public Object getEntry(CGNode n) {
ControlFlowGraph<ISSABasicBlock> cfg = getCFG(n);
ISSABasicBlock entry = cfg.entry();
return new BasicBlockInContext(n, entry);
}
/**
* @param bb
* node in the IPCFG that ends in a call
* @return the nodes that are return sites for this call.
* @throws IllegalArgumentException
* if bb is null
*/
public Iterator<BasicBlockInContext> getReturnSites(BasicBlockInContext bb) {
if (bb == null) {
throw new IllegalArgumentException("bb is null");
}
final CGNode node = bb.getNode();
// a successor node is a return site if it is in the same
// procedure, and is not the entry() node.
Filter isReturn = new Filter() {
public boolean accepts(Object o) {
if (Assertions.verifyAssertions) {
Assertions._assert(o instanceof BasicBlockInContext);
}
BasicBlockInContext other = (BasicBlockInContext) o;
return !other.isEntryBlock() && node.equals(other.getNode());
}
};
return new FilterIterator<BasicBlockInContext>(getSuccNodes(bb), isReturn);
}
public Iterator<BasicBlockInContext> getCallSites(BasicBlockInContext bb) {
if (bb == null) {
throw new IllegalArgumentException("bb is null");
}
ControlFlowGraph<ISSABasicBlock> cfg = getCFG(bb);
Iterator<? extends ISSABasicBlock> it = cfg.getPredNodes(bb.getDelegate());
final CGNode node = bb.getNode();
Function<ISSABasicBlock, BasicBlockInContext> toContext = new Function<ISSABasicBlock, BasicBlockInContext>() {
public BasicBlockInContext apply(ISSABasicBlock object) {
ISSABasicBlock b = object;
return new BasicBlockInContext(node, b);
}
};
MapIterator<ISSABasicBlock, BasicBlockInContext> m = new MapIterator<ISSABasicBlock, BasicBlockInContext>(it, toContext);
return new FilterIterator<BasicBlockInContext>(m, isCall);
}
private final Filter isCall = new Filter() {
public boolean accepts(Object o) {
return hasCall((BasicBlockInContext) o);
}
};
public boolean isReturn(BasicBlockInContext bb) throws IllegalArgumentException {
if (bb == null) {
throw new IllegalArgumentException("bb == null");
}
ControlFlowGraph<ISSABasicBlock> cfg = getCFG(bb);
for (Iterator<? extends ISSABasicBlock> it = cfg.getPredNodes(bb.getDelegate()); it.hasNext();) {
ISSABasicBlock b = it.next();
if (hasCall(new BasicBlockInContext(bb.getNode(), b))) {
return true;
}
}
return false;
}
}