WALA/com.ibm.wala.core/src/com/ibm/wala/analysis/reflection/JavaLangClassContextSelecto...

100 lines
3.9 KiB
Java

/*******************************************************************************
* Copyright (c) 2008 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.analysis.reflection;
import java.util.Collection;
import com.ibm.wala.analysis.typeInference.PointType;
import com.ibm.wala.classLoader.CallSiteReference;
import com.ibm.wala.classLoader.IClass;
import com.ibm.wala.classLoader.IMethod;
import com.ibm.wala.ipa.callgraph.CGNode;
import com.ibm.wala.ipa.callgraph.Context;
import com.ibm.wala.ipa.callgraph.ContextSelector;
import com.ibm.wala.ipa.callgraph.propagation.ConstantKey;
import com.ibm.wala.ipa.callgraph.propagation.InstanceKey;
import com.ibm.wala.ipa.cha.IClassHierarchy;
import com.ibm.wala.types.MethodReference;
import com.ibm.wala.util.collections.HashSetFactory;
import com.ibm.wala.util.intset.EmptyIntSet;
import com.ibm.wala.util.intset.IntSet;
import com.ibm.wala.util.intset.IntSetUtil;
/**
* A {@link ContextSelector} to intercept calls to certain methods on java.lang.Class when the receiver is a type constant
*
* Currently supported methods:
* <ul>
* <li>getConstructor
* <li>getConstructors
* <li>getDeclaredMethod
* <li>getMethods
* </ul>
*/
class JavaLangClassContextSelector implements ContextSelector {
public JavaLangClassContextSelector() {
}
/**
* If the {@link CallSiteReference} invokes a method we understand and c is a type constant, return a {@link JavaTypeContext}
* representing the type named by s, if we can resolve it in the {@link IClassHierarchy}.
*/
@Override
public Context getCalleeTarget(CGNode caller, CallSiteReference site, IMethod callee, InstanceKey[] receiver) {
if (receiver != null && receiver.length > 0 && mayUnderstand(caller, site, callee, receiver[0])) {
return new JavaTypeContext(new PointType(getTypeConstant(receiver[0])));
}
return null;
}
private static IClass getTypeConstant(InstanceKey instance) {
if (instance instanceof ConstantKey) {
ConstantKey c = (ConstantKey) instance;
if (c.getValue() instanceof IClass) {
return (IClass) c.getValue();
}
}
return null;
}
private static final Collection<MethodReference> UNDERSTOOD_METHOD_REFS = HashSetFactory.make();
static {
UNDERSTOOD_METHOD_REFS.add(JavaLangClassContextInterpreter.GET_CONSTRUCTOR);
UNDERSTOOD_METHOD_REFS.add(JavaLangClassContextInterpreter.GET_CONSTRUCTORS);
UNDERSTOOD_METHOD_REFS.add(JavaLangClassContextInterpreter.GET_METHOD);
UNDERSTOOD_METHOD_REFS.add(JavaLangClassContextInterpreter.GET_METHODS);
UNDERSTOOD_METHOD_REFS.add(JavaLangClassContextInterpreter.GET_DECLARED_CONSTRUCTOR);
UNDERSTOOD_METHOD_REFS.add(JavaLangClassContextInterpreter.GET_DECLARED_CONSTRUCTORS);
UNDERSTOOD_METHOD_REFS.add(JavaLangClassContextInterpreter.GET_DECLARED_METHOD);
UNDERSTOOD_METHOD_REFS.add(JavaLangClassContextInterpreter.GET_DECLARED_METHODS);
}
/**
* This object may understand a dispatch to Class.getContructor when the receiver is a type constant.
*/
private static boolean mayUnderstand(CGNode caller, CallSiteReference site, IMethod targetMethod, InstanceKey instance) {
return UNDERSTOOD_METHOD_REFS.contains(targetMethod.getReference()) && getTypeConstant(instance) != null;
}
private static final IntSet thisParameter = IntSetUtil.make(new int[]{0});
@Override
public IntSet getRelevantParameters(CGNode caller, CallSiteReference site) {
if (UNDERSTOOD_METHOD_REFS.contains(site.getDeclaredTarget())) {
return thisParameter;
} else {
return EmptyIntSet.instance;
}
}
}