/*
* Copyright 2011 The Apache Software Foundation
*
* 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 net.sf.cglib.proxy;
import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import net.sf.cglib.core.Signature;
import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.Attribute;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
/**
* Uses bytecode reflection to figure out the targets of all bridge methods
* that use invokespecial, so that we can later rewrite them to use invokevirtual.
*
* @author sberlin@gmail.com (Sam Berlin)
*/
class BridgeMethodResolver {
private final Map/* <Class, Set<Signature> */declToBridge;
public BridgeMethodResolver(Map declToBridge) {
this.declToBridge = declToBridge;
}
/**
* Finds all bridge methods that are being called with invokespecial &
* returns them.
*/
public Map/*<Signature, Signature>*/resolveAll() {
Map resolved = new HashMap();
for (Iterator entryIter = declToBridge.entrySet().iterator(); entryIter.hasNext(); ) {
Map.Entry entry = (Map.Entry)entryIter.next();
Class owner = (Class)entry.getKey();
Set bridges = (Set)entry.getValue();
try {
new ClassReader(owner.getName())
.accept(new BridgedFinder(bridges, resolved),
ClassReader.SKIP_FRAMES | ClassReader.SKIP_DEBUG);
} catch(IOException ignored) {}
}
return resolved;
}
private static class BridgedFinder implements ClassVisitor, MethodVisitor {
private Map/*<Signature, Signature>*/ resolved;
private Set/*<Signature>*/ eligableMethods;
private Signature currentMethod = null;
BridgedFinder(Set eligableMethods, Map resolved) {
this.resolved = resolved;
this.eligableMethods = eligableMethods;
}
public void visit(int version, int access, String name,
String signature, String superName, String[] interfaces) {
}
public MethodVisitor visitMethod(int access, String name, String desc,
String signature, String[] exceptions) {
Signature sig = new Signature(name, desc);
if (eligableMethods.remove(sig)) {
currentMethod = sig;
return this;
} else {
return null;
}
}
public void visitSource(String source, String debug) {
}
public void visitLineNumber(int line, Label start) {
}
public void visitFieldInsn(int opcode, String owner, String name,
String desc) {
}
public void visitEnd() {
}
public void visitInnerClass(String name, String outerName,
String innerName, int access) {
}
public void visitOuterClass(String owner, String name, String desc) {
}
public void visitAttribute(Attribute attr) {
}
public FieldVisitor visitField(int access, String name, String desc,
String signature, Object value) {
return null;
}
public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
return null;
}
public AnnotationVisitor visitAnnotationDefault() {
return null;
}
public AnnotationVisitor visitParameterAnnotation(int parameter,
String desc, boolean visible) {
return null;
}
public void visitCode() {
}
public void visitFrame(int type, int nLocal, Object[] local,
int nStack, Object[] stack) {
}
public void visitIincInsn(int var, int increment) {
}
public void visitInsn(int opcode) {
}
public void visitIntInsn(int opcode, int operand) {
}
public void visitJumpInsn(int opcode, Label label) {
}
public void visitLabel(Label label) {
}
public void visitLdcInsn(Object cst) {
}
public void visitLocalVariable(String name, String desc,
String signature, Label start, Label end, int index) {
}
public void visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels) {
}
public void visitMaxs(int maxStack, int maxLocals) {
}
public void visitMethodInsn(int opcode, String owner, String name,
String desc) {
if (opcode == Opcodes.INVOKESPECIAL && currentMethod != null) {
Signature target = new Signature(name, desc);
// If the target signature is the same as the current,
// we shouldn't change our bridge becaues invokespecial
// is the only way to make progress (otherwise we'll
// get infinite recursion). This would typically
// only happen when a bridge method is created to widen
// the visibility of a superclass' method.
if (!target.equals(currentMethod)) {
resolved.put(currentMethod, target);
}
currentMethod = null;
}
}
public void visitMultiANewArrayInsn(String desc, int dims) {
}
public void visitTableSwitchInsn(int min, int max, Label dflt,
Label[] labels) {
}
public void visitTryCatchBlock(Label start, Label end, Label handler,
String type) {
}
public void visitTypeInsn(int opcode, String desc) {
}
public void visitVarInsn(int opcode, int var) {
}
}
}