WALA/com.ibm.wala.core/src/com/ibm/wala/ipa/modref/ModRef.java

383 lines
14 KiB
Java

/*******************************************************************************
* Copyright (c) 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.modref;
import java.util.Collection;
import java.util.Map;
import java.util.Set;
import com.ibm.wala.classLoader.IClass;
import com.ibm.wala.classLoader.IField;
import com.ibm.wala.ipa.callgraph.CGNode;
import com.ibm.wala.ipa.callgraph.CallGraph;
import com.ibm.wala.ipa.callgraph.CallGraphTransitiveClosure;
import com.ibm.wala.ipa.callgraph.propagation.HeapModel;
import com.ibm.wala.ipa.callgraph.propagation.InstanceKey;
import com.ibm.wala.ipa.callgraph.propagation.PointerAnalysis;
import com.ibm.wala.ipa.callgraph.propagation.PointerKey;
import com.ibm.wala.ipa.slicer.HeapExclusions;
import com.ibm.wala.ssa.IR;
import com.ibm.wala.ssa.SSAArrayLengthInstruction;
import com.ibm.wala.ssa.SSAArrayLoadInstruction;
import com.ibm.wala.ssa.SSAArrayStoreInstruction;
import com.ibm.wala.ssa.SSAGetInstruction;
import com.ibm.wala.ssa.SSAInstruction;
import com.ibm.wala.ssa.SSANewInstruction;
import com.ibm.wala.ssa.SSAPutInstruction;
import com.ibm.wala.util.collections.HashSetFactory;
import com.ibm.wala.util.collections.Iterator2Iterable;
import com.ibm.wala.util.intset.OrdinalSet;
/**
* Mod-ref analysis for heap locations.
*
* For each call graph node, what heap locations (as determined by a heap model) may it read or write, including it's callees
* transitively
*/
public class ModRef<T extends InstanceKey> {
public static <U extends InstanceKey> ModRef<U> make() {
return new ModRef<>();
}
public ModRef() {
}
/**
* For each call graph node, what heap locations (as determined by a heap model) may it write, including its callees transitively
*
* @throws IllegalArgumentException if cg is null
*
*/
public Map<CGNode, OrdinalSet<PointerKey>> computeMod(CallGraph cg, PointerAnalysis<T> pa, HeapExclusions heapExclude) {
if (cg == null) {
throw new IllegalArgumentException("cg is null");
}
Map<CGNode, Collection<PointerKey>> scan = scanForMod(cg, pa, heapExclude);
return CallGraphTransitiveClosure.transitiveClosure(cg, scan);
}
/**
* For each call graph node, what heap locations (as determined by a heap model) may it read, including its callees transitively
*
* @throws IllegalArgumentException if cg is null
*
*/
public Map<CGNode, OrdinalSet<PointerKey>> computeRef(CallGraph cg, PointerAnalysis<T> pa, HeapExclusions heapExclude) {
if (cg == null) {
throw new IllegalArgumentException("cg is null");
}
Map<CGNode, Collection<PointerKey>> scan = scanForRef(cg, pa, heapExclude);
return CallGraphTransitiveClosure.transitiveClosure(cg, scan);
}
/**
* For each call graph node, what heap locations (as determined by a heap model) may it write, including its callees transitively
*
*/
public Map<CGNode, OrdinalSet<PointerKey>> computeMod(CallGraph cg, PointerAnalysis<T> pa) {
return computeMod(cg, pa, null);
}
/**
* For each call graph node, what heap locations (as determined by a heap model) may it read, including its callees transitively
*
*/
public Map<CGNode, OrdinalSet<PointerKey>> computeRef(CallGraph cg, PointerAnalysis<T> pa) {
return computeRef(cg, pa, null);
}
/**
* For each call graph node, what heap locations (as determined by a heap model) may it write, <b> NOT </b> including its
* callees transitively
*
* @param heapExclude
*/
private Map<CGNode, Collection<PointerKey>> scanForMod(CallGraph cg, final PointerAnalysis<T> pa, final HeapExclusions heapExclude) {
return CallGraphTransitiveClosure.collectNodeResults(cg, n -> scanNodeForMod(n, pa, heapExclude));
}
/**
* For each call graph node, what heap locations (as determined by a heap model) may it read, <b> NOT </b> including its callees
* transitively
*
* @param heapExclude
*/
private Map<CGNode, Collection<PointerKey>> scanForRef(CallGraph cg, final PointerAnalysis<T> pa, final HeapExclusions heapExclude) {
return CallGraphTransitiveClosure.collectNodeResults(cg, n -> scanNodeForRef(n, pa, heapExclude));
}
public ExtendedHeapModel makeHeapModel(PointerAnalysis<T> pa) {
HeapModel heapModel = pa.getHeapModel();
if (heapModel instanceof ExtendedHeapModel) {
return (ExtendedHeapModel) heapModel;
} else {
return new DelegatingExtendedHeapModel(heapModel);
}
}
/**
* For a call graph node, what heap locations (as determined by a heap model) may it write, <b> NOT </b> including it's callees
* transitively
*
* @param heapExclude
*/
private Collection<PointerKey> scanNodeForMod(final CGNode n, final PointerAnalysis<T> pa, HeapExclusions heapExclude) {
Collection<PointerKey> result = HashSetFactory.make();
final ExtendedHeapModel h = makeHeapModel(pa);
SSAInstruction.Visitor v = makeModVisitor(n, result, pa, h);
IR ir = n.getIR();
if (ir != null) {
for (SSAInstruction inst : Iterator2Iterable.make(ir.iterateNormalInstructions())) {
inst.visit(v);
assert ! result.contains(null);
}
}
if (heapExclude != null) {
result = heapExclude.filter(result);
}
return result;
}
/**
* For a call graph node, what heap locations (as determined by a heap model) may it read, <b> NOT </b> including it's callees
* transitively
*/
private Collection<PointerKey> scanNodeForRef(final CGNode n, final PointerAnalysis<T> pa, HeapExclusions heapExclude) {
Collection<PointerKey> result = HashSetFactory.make();
final ExtendedHeapModel h = makeHeapModel(pa);
SSAInstruction.Visitor v = makeRefVisitor(n, result, pa, h);
IR ir = n.getIR();
if (ir != null) {
for (SSAInstruction x : Iterator2Iterable.make(ir.iterateNormalInstructions())) {
x.visit(v);
assert ! result.contains(null) : x;
}
}
if (heapExclude != null) {
result = heapExclude.filter(result);
}
return result;
}
public static class RefVisitor<T extends InstanceKey, H extends ExtendedHeapModel> extends SSAInstruction.Visitor {
protected final CGNode n;
protected final Collection<PointerKey> result;
protected final PointerAnalysis<T> pa;
protected final H h;
public RefVisitor(CGNode n, Collection<PointerKey> result, PointerAnalysis<T> pa2, H h) {
this.n = n;
this.result = result;
this.pa = pa2;
this.h = h;
}
@Override
public void visitArrayLength(SSAArrayLengthInstruction instruction) {
PointerKey ref = h.getPointerKeyForLocal(n, instruction.getArrayRef());
for (InstanceKey i : pa.getPointsToSet(ref)) {
result.add(h.getPointerKeyForArrayLength(i));
}
}
@Override
public void visitArrayLoad(SSAArrayLoadInstruction instruction) {
PointerKey ref = h.getPointerKeyForLocal(n, instruction.getArrayRef());
for (InstanceKey i : pa.getPointsToSet(ref)) {
result.add(h.getPointerKeyForArrayContents(i));
}
}
@Override
public void visitGet(SSAGetInstruction instruction) {
IField f = pa.getClassHierarchy().resolveField(instruction.getDeclaredField());
if (f != null) {
if (instruction.isStatic()) {
result.add(h.getPointerKeyForStaticField(f));
} else {
PointerKey ref = h.getPointerKeyForLocal(n, instruction.getRef());
for (InstanceKey i : pa.getPointsToSet(ref)) {
PointerKey x = h.getPointerKeyForInstanceField(i, f);
if (x != null) {
result.add(x);
}
}
}
}
}
}
public static class ModVisitor<T extends InstanceKey, H extends ExtendedHeapModel> extends SSAInstruction.Visitor {
protected final CGNode n;
protected final Collection<PointerKey> result;
protected final H h;
protected final PointerAnalysis<T> pa;
private final boolean ignoreAllocHeapDefs;
public ModVisitor(CGNode n, Collection<PointerKey> result, H h, PointerAnalysis<T> pa,
boolean ignoreAllocHeapDefs) {
this.n = n;
this.result = result;
this.h = h;
this.pa = pa;
this.ignoreAllocHeapDefs = ignoreAllocHeapDefs;
}
@Override
public void visitNew(SSANewInstruction instruction) {
if (instruction.getConcreteType().isArrayType()) {
int dim = instruction.getConcreteType().getDimensionality();
if (dim > 1) {
// we need to handle the top-level allocation, just like the 1D case
InstanceKey ik = h.getInstanceKeyForAllocation(n, instruction.getNewSite());
// note that ik can be null depending on class hierarchy exclusions or
// for incomplete programs. If so, just ignore it and keep going.
if (ik != null) {
PointerKey pk = h.getPointerKeyForArrayContents(ik);
assert pk != null;
result.add(pk);
pk = h.getPointerKeyForArrayLength(ik);
assert pk != null;
result.add(pk);
}
// now, the inner dimensions
for (int d = 0; d < dim - 1; d++) {
InstanceKey i = h.getInstanceKeyForMultiNewArray(n, instruction.getNewSite(), d);
// note that i can be null depending on class hierarchy exclusions
// or for incomplete programs. If so, just ignore it and keep going.
if (i != null) {
PointerKey pk = h.getPointerKeyForArrayContents(i);
assert pk != null;
result.add(pk);
pk = h.getPointerKeyForArrayLength(i);
assert pk != null;
result.add(pk);
}
}
} else {
// allocation of 1D arr "writes" the contents of the array and the
// length field
InstanceKey i = h.getInstanceKeyForAllocation(n, instruction.getNewSite());
// note that i can be null depending on class hierarchy exclusions or
// for incomplete programs. If so, just ignore it and keep going.
if (i != null) {
if (!ignoreAllocHeapDefs) {
PointerKey pk = h.getPointerKeyForArrayContents(i);
assert pk != null;
result.add(pk);
}
PointerKey pk = h.getPointerKeyForArrayLength(i);
assert pk != null;
result.add(pk);
}
}
} else {
if (!ignoreAllocHeapDefs) {
// allocation of a scalar "writes" all fields in the scalar
InstanceKey i = h.getInstanceKeyForAllocation(n, instruction.getNewSite());
if (i != null) {
IClass type = i.getConcreteType();
for (IField f : type.getAllInstanceFields()) {
PointerKey pk = h.getPointerKeyForInstanceField(i, f);
assert pk != null;
result.add(pk);
}
}
}
}
}
@Override
public void visitArrayStore(SSAArrayStoreInstruction instruction) {
PointerKey ref = h.getPointerKeyForLocal(n, instruction.getArrayRef());
for (InstanceKey i : pa.getPointsToSet(ref)) {
result.add(h.getPointerKeyForArrayContents(i));
}
}
@Override
public void visitPut(SSAPutInstruction instruction) {
IField f = pa.getClassHierarchy().resolveField(instruction.getDeclaredField());
if (f != null) {
if (instruction.isStatic()) {
result.add(h.getPointerKeyForStaticField(f));
} else {
PointerKey ref = h.getPointerKeyForLocal(n, instruction.getRef());
if (ref != null) {
for (InstanceKey i : pa.getPointsToSet(ref)) {
result.add(h.getPointerKeyForInstanceField(i, f));
}
}
}
}
}
}
protected ModVisitor makeModVisitor(CGNode n, Collection<PointerKey> result, PointerAnalysis<T> pa, ExtendedHeapModel h) {
return makeModVisitor(n, result, pa, h, false);
}
protected ModVisitor<T, ? extends ExtendedHeapModel> makeModVisitor(CGNode n, Collection<PointerKey> result, PointerAnalysis<T> pa, ExtendedHeapModel h,
boolean ignoreAllocHeapDefs) {
return n.getMethod().getDeclaringClass().getClassLoader().getLanguage().makeModVisitor(n, result, pa, h, ignoreAllocHeapDefs);
//return new ModVisitor<>(n, result, h, pa, ignoreAllocHeapDefs);
}
/**
* Compute the set of {@link PointerKey}s that represent pointers that instruction s may write to.
*/
public Set<PointerKey> getMod(CGNode n, ExtendedHeapModel h, PointerAnalysis<T> pa, SSAInstruction s, HeapExclusions hexcl) {
return getMod(n, h, pa, s, hexcl, false);
}
/**
* Compute the set of {@link PointerKey}s that represent pointers that instruction s may write to.
*/
public Set<PointerKey> getMod(CGNode n, ExtendedHeapModel h, PointerAnalysis<T> pa, SSAInstruction s, HeapExclusions hexcl,
boolean ignoreAllocHeapDefs) {
if (s == null) {
throw new IllegalArgumentException("s is null");
}
Set<PointerKey> result = HashSetFactory.make(2);
ModVisitor v = makeModVisitor(n, result, pa, h, ignoreAllocHeapDefs);
s.visit(v);
return hexcl == null ? result : hexcl.filter(result);
}
protected RefVisitor<T, ? extends ExtendedHeapModel> makeRefVisitor(CGNode n, Collection<PointerKey> result, PointerAnalysis<T> pa, ExtendedHeapModel h) {
return n.getMethod().getDeclaringClass().getClassLoader().getLanguage().makeRefVisitor(n, result, pa, h);
}
/**
* Compute the set of {@link PointerKey}s that represent pointers that instruction s may read.
*/
public Set<PointerKey> getRef(CGNode n, ExtendedHeapModel h, PointerAnalysis<T> pa, SSAInstruction s, HeapExclusions hexcl) {
if (s == null) {
throw new IllegalArgumentException("s is null");
}
Set<PointerKey> result = HashSetFactory.make(2);
RefVisitor v = makeRefVisitor(n, result, pa, h);
s.visit(v);
return hexcl == null ? result : hexcl.filter(result);
}
}