/*******************************************************************************
* Copyright (c) 2014 Jeff Martin.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the GNU Public License v3.0
* which accompanies this distribution, and is available at
* http://www.gnu.org/licenses/gpl.html
*
* Contributors:
* Jeff Martin - initial API and implementation
******************************************************************************/
package cuchaz.enigma.bytecode;
import java.util.Iterator;
import javassist.bytecode.BadBytecode;
import javassist.bytecode.CodeAttribute;
import javassist.bytecode.CodeIterator;
import javassist.bytecode.ConstPool;
import javassist.bytecode.Descriptor;
import javassist.bytecode.Opcode;
import cuchaz.enigma.bytecode.CheckCastIterator.CheckCast;
import cuchaz.enigma.mapping.ClassEntry;
import cuchaz.enigma.mapping.MethodEntry;
public class CheckCastIterator implements Iterator<CheckCast>
{
public static class CheckCast
{
public String className;
public MethodEntry prevMethodEntry;
public CheckCast( String className, MethodEntry prevMethodEntry )
{
this.className = className;
this.prevMethodEntry = prevMethodEntry;
}
}
private ConstPool m_constants;
private CodeAttribute m_attribute;
private CodeIterator m_iter;
private CheckCast m_next;
public CheckCastIterator( CodeAttribute codeAttribute )
throws BadBytecode
{
m_constants = codeAttribute.getConstPool();
m_attribute = codeAttribute;
m_iter = m_attribute.iterator();
m_next = getNext();
}
@Override
public boolean hasNext( )
{
return m_next != null;
}
@Override
public CheckCast next( )
{
CheckCast out = m_next;
try
{
m_next = getNext();
}
catch( BadBytecode ex )
{
throw new Error( ex );
}
return out;
}
@Override
public void remove( )
{
throw new UnsupportedOperationException();
}
private CheckCast getNext( )
throws BadBytecode
{
int prevPos = 0;
while( m_iter.hasNext() )
{
int pos = m_iter.next();
int opcode = m_iter.byteAt( pos );
switch( opcode )
{
case Opcode.CHECKCAST:
// get the type of this op code (next two bytes are a classinfo index)
MethodEntry prevMethodEntry = getMethodEntry( prevPos );
if( prevMethodEntry != null )
{
return new CheckCast(
m_constants.getClassInfo( m_iter.s16bitAt( pos + 1 ) ),
prevMethodEntry
);
}
break;
}
prevPos = pos;
}
return null;
}
private MethodEntry getMethodEntry( int pos )
{
switch( m_iter.byteAt( pos ) )
{
case Opcode.INVOKEVIRTUAL:
case Opcode.INVOKESTATIC:
case Opcode.INVOKEDYNAMIC:
case Opcode.INVOKESPECIAL:
{
int index = m_iter.s16bitAt( pos + 1 );
return new MethodEntry(
new ClassEntry( Descriptor.toJvmName( m_constants.getMethodrefClassName( index ) ) ),
m_constants.getMethodrefName( index ),
m_constants.getMethodrefType( index )
);
}
case Opcode.INVOKEINTERFACE:
{
int index = m_iter.s16bitAt( pos + 1 );
return new MethodEntry(
new ClassEntry( Descriptor.toJvmName( m_constants.getInterfaceMethodrefClassName( index ) ) ),
m_constants.getInterfaceMethodrefName( index ),
m_constants.getInterfaceMethodrefType( index )
);
}
}
return null;
}
public Iterable<CheckCast> casts( )
{
return new Iterable<CheckCast>( )
{
@Override
public Iterator<CheckCast> iterator( )
{
return CheckCastIterator.this;
}
};
}
}