/*
* Copyright 2007 Johannes Rieken
* Copyright 2010 Google Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
package com.google.java.contract.core.agent;
import com.google.java.contract.Requires;
import com.google.java.contract.core.util.JavaUtils;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.Handle;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
/**
* A class adapter that transforms injected contract methods to remove
* contract compilation artefacts:
*
* <ul>
* <li>fix calls to {@code access$n} synthetic methods for inner/nested
* classes.
* </ul>
*
* @author nhat.minh.le@huoc.org (Nhat Minh Lê)
*/
class ContractFixingClassAdapter extends ClassVisitor {
/**
* A method adapter that amends calls to {@code access$n} synthetic
* methods. These methods are generated for access to members from
* inner/nested classes. Contract compilation may generate some of
* these, which are renamed and injected into the original class
* bytecode during instrumentation. Calls to these methods need to
* be fixed to use the new names.
*/
protected static class AccessMethodAdapter extends MethodVisitor {
/**
* Constructs a new AccessMethodAdapter.
*
* @param mv the MethodVisitor this adapter delegates to
*/
@Requires("mv != null")
public AccessMethodAdapter(MethodVisitor mv) {
super(Opcodes.ASM5, mv);
}
/**
* Converts calls to {@code access$n} synthetic methods to the
* equivalent injected methods.
*/
@Override
public void visitMethodInsn(int opcode, String owner, String name,
String desc, boolean itf) {
if (!name.startsWith("access$")) {
mv.visitMethodInsn(opcode, owner, name, desc, itf);
} else {
String newName = JavaUtils.SYNTHETIC_MEMBER_PREFIX + name;
mv.visitMethodInsn(opcode, owner, newName, desc, itf);
}
}
/**
* Converts calls to {@code lambda$n} synthetic methods to the
* equivalent injected methods.
*/
@Override
public void visitInvokeDynamicInsn(String name, String desc,
Handle bsm, Object... bsmArgs) {
for (int i = 0; i < bsmArgs.length; ++i) {
if (!(bsmArgs[i] instanceof Handle)) {
continue;
}
Handle h = (Handle)bsmArgs[i];
if (!h.getName().startsWith("lambda$")) {
continue;
}
String newName = JavaUtils.SYNTHETIC_MEMBER_PREFIX + h.getName();
bsmArgs[i] = new Handle(h.getTag(), h.getOwner(),
newName, h.getDesc());
}
mv.visitInvokeDynamicInsn(name, desc, bsm, bsmArgs);
}
}
/**
* Constructs a new ContractFixingClassAdapter.
*
* @param cv the ClassVisitor this adapter delegates to
*/
@Requires("cv != null")
public ContractFixingClassAdapter(ClassVisitor cv) {
super(Opcodes.ASM5, cv);
}
/**
* Visits the specified method fixing method calls.
*/
@Override
public MethodVisitor visitMethod(int access, String name, String desc,
String signature, String[] exceptions) {
MethodVisitor mv = cv.visitMethod(access | Opcodes.ACC_SYNTHETIC,
name, desc, signature, exceptions);
return new AccessMethodAdapter(mv);
}
}