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package com.ibm.wala.demandpa.alg.refinepolicy;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import com.ibm.wala.classLoader.IClass;
import com.ibm.wala.classLoader.IField;
import com.ibm.wala.demandpa.alg.statemachine.StateMachine;
import com.ibm.wala.demandpa.flowgraph.IFlowLabel;
import com.ibm.wala.demandpa.util.ArrayContents;
import com.ibm.wala.ipa.callgraph.propagation.PointerKey;
import com.ibm.wala.ipa.cha.IClassHierarchy;
import com.ibm.wala.types.ClassLoaderReference;
import com.ibm.wala.types.TypeReference;
/**
* Manually annotated policy for refining field accesses.
*/
public class ManualFieldPolicy implements FieldRefinePolicy {
protected final Pattern refinePattern;// =
// Pattern.compile("Lca/mcgill/sable/util|Ljava/util|Lpolyglot/util/TypedList");
private static final int NUM_DECISIONS_TO_TRACK = 10;
final private boolean[] decisions = new boolean[NUM_DECISIONS_TO_TRACK];
private int curDecision;
final private IClass[] encounteredClasses = new IClass[NUM_DECISIONS_TO_TRACK];
@Override
public boolean shouldRefine(IField field, PointerKey basePtr, PointerKey val, IFlowLabel label, StateMachine.State state) {
if (field == null) {
throw new IllegalArgumentException("null field");
}
if (field == ArrayContents.v()) {
return true;
} else {
final IClass declaringClass = field.getDeclaringClass();
final Matcher m = refinePattern.matcher(declaringClass.toString());
final boolean foundPattern = m.find();
recordDecision(declaringClass, foundPattern);
return foundPattern;
}
}
private void recordDecision(final IClass declaringClass, final boolean foundPattern) {
if (curDecision < NUM_DECISIONS_TO_TRACK) {
IClass topMostClass = removeInner(declaringClass);
if (notSuperOfAnyEncountered(topMostClass)) {
encounteredClasses[curDecision] = topMostClass;
decisions[curDecision] = foundPattern;
curDecision++;
}
}
}
private boolean notSuperOfAnyEncountered(IClass klass) {
for (int i = 0; i < curDecision; i++) {
if (cha.isAssignableFrom(klass, encounteredClasses[i])) {
return false;
}
}
return true;
}
private final IClassHierarchy cha;
/**
* @return the top-level {@link IClass} where klass is declared, or klass itself if klass is top-level
*/
private IClass removeInner(IClass klass) {
ClassLoaderReference cl = klass.getClassLoader().getReference();
String klassStr = klass.getName().toString();
int dollarIndex = klassStr.indexOf('$');
if (dollarIndex == -1) {
return klass;
} else {
String topMostName = klassStr.substring(0, dollarIndex);
IClass topMostClass = cha.lookupClass(TypeReference.findOrCreate(cl, topMostName));
assert topMostClass != null;
return topMostClass;
}
}
/**
* @param refinePattern a pattern for detecting which match edges to refine. If the <em>declaring class</em> of the field related
* to the match edge matches the pattern, the match edge will be refined. For example, the pattern
* <code>Pattern.compile("Ljava/util")</code> will cause all fields of classes in the <code>java.util</code> package to
* be refined.
*/
public ManualFieldPolicy(IClassHierarchy cha, Pattern refinePattern) {
this.cha = cha;
this.refinePattern = refinePattern;
}
@Override
public boolean nextPass() {
return false;
}
/**
*
*
* @return a String representation of the decisions made by this
*/
public String getHistory() {
StringBuilder ret = new StringBuilder();
for (int i = 0; i < curDecision; i++) {
if (decisions[i]) {
ret.append("refined ");
} else {
ret.append("skipped ");
}
ret.append(encounteredClasses[i]);
if (i + 1 < curDecision) {
ret.append(", ");
}
}
return ret.toString();
}
}