/*
* Copyright 2002-2008 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.aop.aspectj;
import java.lang.reflect.Field;
import org.aspectj.weaver.ResolvedType;
import org.aspectj.weaver.ast.And;
import org.aspectj.weaver.ast.Call;
import org.aspectj.weaver.ast.FieldGetCall;
import org.aspectj.weaver.ast.HasAnnotation;
import org.aspectj.weaver.ast.ITestVisitor;
import org.aspectj.weaver.ast.Instanceof;
import org.aspectj.weaver.ast.Literal;
import org.aspectj.weaver.ast.Not;
import org.aspectj.weaver.ast.Or;
import org.aspectj.weaver.ast.Test;
import org.aspectj.weaver.internal.tools.MatchingContextBasedTest;
import org.aspectj.weaver.reflect.ReflectionVar;
import org.aspectj.weaver.reflect.ShadowMatchImpl;
import org.aspectj.weaver.tools.ShadowMatch;
import org.springframework.util.ClassUtils;
import org.springframework.util.ReflectionUtils;
/**
* This class encapsulates some AspectJ internal knowledge that should be
* pushed back into the AspectJ project in a future release.
*
* <p>It relies on implementation specific knowledge in AspectJ to break
* encapsulation and do something AspectJ was not designed to do: query
* the types of runtime tests that will be performed. The code here should
* migrate to <code>ShadowMatch.getVariablesInvolvedInRuntimeTest()</code>
* or some similar operation.
*
* <p>See <a href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=151593"/>.
*
* @author Adrian Colyer
* @author Ramnivas Laddad
* @since 2.0
*/
class RuntimeTestWalker {
private final Test runtimeTest;
public RuntimeTestWalker(ShadowMatch shadowMatch) {
ShadowMatchImpl shadowMatchImplementation = (ShadowMatchImpl) shadowMatch;
try {
Field testField = shadowMatchImplementation.getClass().getDeclaredField("residualTest");
ReflectionUtils.makeAccessible(testField);
this.runtimeTest = (Test) testField.get(shadowMatch);
}
catch (NoSuchFieldException noSuchFieldEx) {
throw new IllegalStateException("The version of aspectjtools.jar / aspectjweaver.jar " +
"on the classpath is incompatible with this version of Spring: Expected field " +
"'runtimeTest' is not present on ShadowMatchImpl class.");
}
catch (IllegalAccessException illegalAccessEx) {
// Famous last words... but I don't see how this can happen given the
// makeAccessible call above
throw new IllegalStateException("Unable to access ShadowMatchImpl.runtimeTest field.");
}
}
/**
* If the test uses any of the this, target, at_this, at_target, and at_annotation vars,
* then it tests subtype sensitive vars.
*/
public boolean testsSubtypeSensitiveVars() {
return new SubtypeSensitiveVarTypeTestVisitor().testsSubtypeSensitiveVars(this.runtimeTest);
}
public boolean testThisInstanceOfResidue(Class thisClass) {
return new ThisInstanceOfResidueTestVisitor(thisClass).thisInstanceOfMatches(this.runtimeTest);
}
public boolean testTargetInstanceOfResidue(Class targetClass) {
return new TargetInstanceOfResidueTestVisitor(targetClass).targetInstanceOfMatches(this.runtimeTest);
}
private static class TestVisitorAdapter implements ITestVisitor {
protected static final int THIS_VAR = 0;
protected static final int TARGET_VAR = 1;
protected static final int AT_THIS_VAR = 3;
protected static final int AT_TARGET_VAR = 4;
protected static final int AT_ANNOTATION_VAR = 8;
public void visit(And e) {
e.getLeft().accept(this);
e.getRight().accept(this);
}
public void visit(Or e) {
e.getLeft().accept(this);
e.getRight().accept(this);
}
public void visit(Not e) {
e.getBody().accept(this);
}
public void visit(Instanceof i) {
}
public void visit(Literal literal) {
}
public void visit(Call call) {
}
public void visit(FieldGetCall fieldGetCall) {
}
public void visit(HasAnnotation hasAnnotation) {
}
public void visit(MatchingContextBasedTest matchingContextTest) {
}
protected int getVarType(ReflectionVar v) {
try {
Field varTypeField = ReflectionVar.class.getDeclaredField("varType");
ReflectionUtils.makeAccessible(varTypeField);
Integer varTypeValue = (Integer) varTypeField.get(v);
return varTypeValue.intValue();
}
catch (NoSuchFieldException noSuchFieldEx) {
throw new IllegalStateException("the version of aspectjtools.jar / aspectjweaver.jar " +
"on the classpath is incompatible with this version of Spring:- expected field " +
"'varType' is not present on ReflectionVar class");
}
catch (IllegalAccessException illegalAccessEx) {
// Famous last words... but I don't see how this can happen given the
// makeAccessible call above
throw new IllegalStateException("Unable to access ReflectionVar.varType field.");
}
}
}
private static abstract class InstanceOfResidueTestVisitor extends TestVisitorAdapter {
private Class matchClass;
private boolean matches;
private int matchVarType;
public InstanceOfResidueTestVisitor(Class matchClass, boolean defaultMatches, int matchVarType) {
this.matchClass = matchClass;
this.matches = defaultMatches;
this.matchVarType = matchVarType;
}
public boolean instanceOfMatches(Test test) {
test.accept(this);
return matches;
}
public void visit(Instanceof i) {
ResolvedType type = (ResolvedType) i.getType();
int varType = getVarType((ReflectionVar) i.getVar());
if (varType != this.matchVarType) {
return;
}
try {
Class typeClass = ClassUtils.forName(type.getName(), this.matchClass.getClassLoader());
// Don't use ReflectionType.isAssignableFrom() as it won't be aware of (Spring) mixins
this.matches = typeClass.isAssignableFrom(this.matchClass);
}
catch (ClassNotFoundException ex) {
this.matches = false;
}
}
}
/**
* Check if residue of target(TYPE) kind. See SPR-3783 for more details.
*/
private static class TargetInstanceOfResidueTestVisitor extends InstanceOfResidueTestVisitor {
public TargetInstanceOfResidueTestVisitor(Class targetClass) {
super(targetClass, false, TARGET_VAR);
}
public boolean targetInstanceOfMatches(Test test) {
return instanceOfMatches(test);
}
}
/**
* Check if residue of this(TYPE) kind. See SPR-2979 for more details.
*/
private static class ThisInstanceOfResidueTestVisitor extends InstanceOfResidueTestVisitor {
public ThisInstanceOfResidueTestVisitor(Class thisClass) {
super(thisClass, true, THIS_VAR);
}
// TODO: Optimization: Process only if this() specifies a type and not an identifier.
public boolean thisInstanceOfMatches(Test test) {
return instanceOfMatches(test);
}
}
private static class SubtypeSensitiveVarTypeTestVisitor extends TestVisitorAdapter {
private final Object thisObj = new Object();
private final Object targetObj = new Object();
private final Object[] argsObjs = new Object[0];
private boolean testsSubtypeSensitiveVars = false;
public boolean testsSubtypeSensitiveVars(Test aTest) {
aTest.accept(this);
return this.testsSubtypeSensitiveVars;
}
public void visit(Instanceof i) {
ReflectionVar v = (ReflectionVar) i.getVar();
Object varUnderTest = v.getBindingAtJoinPoint(thisObj,targetObj,argsObjs);
if ((varUnderTest == thisObj) || (varUnderTest == targetObj)) {
this.testsSubtypeSensitiveVars = true;
}
}
public void visit(HasAnnotation hasAnn) {
// If you thought things were bad before, now we sink to new levels of horror...
ReflectionVar v = (ReflectionVar) hasAnn.getVar();
int varType = getVarType(v);
if ((varType == AT_THIS_VAR) || (varType == AT_TARGET_VAR) || (varType == AT_ANNOTATION_VAR)) {
this.testsSubtypeSensitiveVars = true;
}
}
}
}