added identifier renaming capability

copied some code over from M3L to handle the heavy bytecode magic.
It's ok... M3L will eventually depend on Enigma.
Completely restructured the mappings though. This way is better. =)

1 files changed, 316 insertions, 0 deletions

diff --git a/src/cuchaz/enigma/bytecode/ConstPoolEditor.java b/src/cuchaz/enigma/bytecode/ConstPoolEditor.java
new file mode 100644
index 0000000..aa6149c
--- /dev/null
+++ b/src/cuchaz/enigma/bytecode/ConstPoolEditor.java
@@ -0,0 +1,316 @@
+/*******************************************************************************
+ * 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.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.util.HashMap;
+
+import javassist.bytecode.ConstPool;
+import javassist.bytecode.Descriptor;
+import cuchaz.enigma.bytecode.accessors.ClassInfoAccessor;
+import cuchaz.enigma.bytecode.accessors.ConstInfoAccessor;
+import cuchaz.enigma.bytecode.accessors.MemberRefInfoAccessor;
+
+public class ConstPoolEditor
+{
+        private static Method m_getItem;
+        private static Method m_addItem;
+        private static Method m_addItem0;
+        private static Field m_items;
+        private static Field m_cache;
+        private static Field m_numItems;
+        private static Field m_objects;
+        private static Field m_elements;
+        private static Method m_methodWritePool;
+        private static Constructor<ConstPool> m_constructorPool;
+        
+        static
+        {
+                try
+                {
+                        m_getItem = ConstPool.class.getDeclaredMethod( "getItem", int.class );
+                        m_getItem.setAccessible( true );
+                        
+                        m_addItem = ConstPool.class.getDeclaredMethod( "addItem", Class.forName( "javassist.bytecode.ConstInfo" ) );
+                        m_addItem.setAccessible( true );
+                        
+                        m_addItem0 = ConstPool.class.getDeclaredMethod( "addItem0", Class.forName( "javassist.bytecode.ConstInfo" ) );
+                        m_addItem0.setAccessible( true );
+                        
+                        m_items = ConstPool.class.getDeclaredField( "items" );
+                        m_items.setAccessible( true );
+                        
+                        m_cache = ConstPool.class.getDeclaredField( "itemsCache" );
+                        m_cache.setAccessible( true );
+                        
+                        m_numItems = ConstPool.class.getDeclaredField( "numOfItems" );
+                        m_numItems.setAccessible( true );
+                        
+                        m_objects = Class.forName( "javassist.bytecode.LongVector" ).getDeclaredField( "objects" );
+                        m_objects.setAccessible( true );
+                        
+                        m_elements = Class.forName( "javassist.bytecode.LongVector" ).getDeclaredField( "elements" );
+                        m_elements.setAccessible( true );
+                        
+                        m_methodWritePool = ConstPool.class.getDeclaredMethod( "write", DataOutputStream.class );
+                        m_methodWritePool.setAccessible( true );
+                        
+                        m_constructorPool = ConstPool.class.getDeclaredConstructor( DataInputStream.class );
+                        m_constructorPool.setAccessible( true );
+                }
+                catch( Exception ex )
+                {
+                        throw new Error( ex );
+                }
+        }
+        
+        private ConstPool m_pool;
+        
+        public ConstPoolEditor( ConstPool pool )
+        {
+                m_pool = pool;
+        }
+        
+        public void writePool( DataOutputStream out )
+        {
+                try
+                {
+                        m_methodWritePool.invoke( m_pool, out );
+                }
+                catch( Exception ex )
+                {
+                        throw new Error( ex );
+                }
+        }
+        
+        public static ConstPool readPool( DataInputStream in )
+        {
+                try
+                {
+                        return m_constructorPool.newInstance( in );
+                }
+                catch( Exception ex )
+                {
+                        throw new Error( ex );
+                }
+        }
+        
+        public String getMemberrefClassname( int memberrefIndex )
+        {
+                return Descriptor.toJvmName( m_pool.getClassInfo( m_pool.getMemberClass( memberrefIndex ) ) );
+        }
+        
+        public String getMemberrefName( int memberrefIndex )
+        {
+                return m_pool.getUtf8Info( m_pool.getNameAndTypeName( m_pool.getMemberNameAndType( memberrefIndex ) ) );
+        }
+        
+        public String getMemberrefType( int memberrefIndex )
+        {
+                return m_pool.getUtf8Info( m_pool.getNameAndTypeDescriptor( m_pool.getMemberNameAndType( memberrefIndex ) ) );
+        }
+        
+        public ConstInfoAccessor getItem( int index )
+        {
+                try
+                {
+                        Object entry = m_getItem.invoke( m_pool, index );
+                        if( entry == null )
+                        {
+                                return null;
+                        }
+                        return new ConstInfoAccessor( entry );
+                }
+                catch( Exception ex )
+                {
+                        throw new Error( ex );
+                }
+        }
+        
+        public int addItem( Object item )
+        {
+                try
+                {
+                        return (Integer)m_addItem.invoke( m_pool, item );
+                }
+                catch( Exception ex )
+                {
+                        throw new Error( ex );
+                }
+        }
+        
+        public int addItemForceNew( Object item )
+        {
+                try
+                {
+                        return (Integer)m_addItem0.invoke( m_pool, item );
+                }
+                catch( Exception ex )
+                {
+                        throw new Error( ex );
+                }
+        }
+        @SuppressWarnings( "rawtypes" )
+        public void removeLastItem( )
+        {
+                try
+                {
+                        // remove the item from the cache
+                        HashMap cache = getCache();
+                        if( cache != null )
+                        {
+                                Object item = getItem( m_pool.getSize() - 1 );
+                                cache.remove( item );
+                        }
+                        
+                        // remove the actual item
+                        // based off of LongVector.addElement()
+                        Object items = m_items.get( m_pool );
+                        Object[][] objects = (Object[][])m_objects.get( items );
+                        int numElements = (Integer)m_elements.get( items ) - 1;
+                        int nth = numElements >> 7;
+                int offset = numElements & (128 - 1);
+                objects[nth][offset] = null;
+                        
+                        // decrement the number of items
+                        m_elements.set( items, numElements );
+                        m_numItems.set( m_pool, (Integer)m_numItems.get( m_pool ) - 1 );
+                }
+                catch( Exception ex )
+                {
+                        throw new Error( ex );
+                }
+        }
+        
+        @SuppressWarnings( "rawtypes" )
+        /* TEMP */public HashMap getCache( )
+        {
+                try
+                {
+                        return (HashMap)m_cache.get( m_pool );
+                }
+                catch( Exception ex )
+                {
+                        throw new Error( ex );
+                }
+        }
+        
+        @SuppressWarnings( { "rawtypes", "unchecked" } )
+        public void changeMemberrefNameAndType( int memberrefIndex, String newName, String newType )
+        {
+                // NOTE: when changing values, we always need to copy-on-write
+                try
+                {
+                        // get the memberref item
+                        Object item = getItem( memberrefIndex ).getItem();
+                        
+                        // update the cache
+                        HashMap cache = getCache();
+                        if( cache != null )
+                        {
+                                cache.remove( item );
+                        }
+                        
+                        new MemberRefInfoAccessor( item ).setNameAndTypeIndex( m_pool.addNameAndTypeInfo( newName, newType ) );
+                        
+                        // update the cache
+                        if( cache != null )
+                        {
+                                cache.put( item, item );
+                        }
+                }
+                catch( Exception ex )
+                {
+                        throw new Error( ex );
+                }
+                
+                // make sure the change worked
+                assert( newName.equals( getMemberrefName( memberrefIndex ) ) );
+                assert( newType.equals( getMemberrefType( memberrefIndex ) ) );
+        }
+        
+        @SuppressWarnings( { "rawtypes", "unchecked" } )
+        public void changeClassName( int classNameIndex, String newName )
+        {
+                // NOTE: when changing values, we always need to copy-on-write
+                try
+                {
+                        // get the class item
+                        Object item = getItem( classNameIndex ).getItem();
+                        
+                        // update the cache
+                        HashMap cache = getCache();
+                        if( cache != null )
+                        {
+                                cache.remove( item );
+                        }
+                        
+                        // add the new name and repoint the name-and-type to it
+                        new ClassInfoAccessor( item ).setNameIndex( m_pool.addUtf8Info( newName ) );
+                        
+                        // update the cache
+                        if( cache != null )
+                        {
+                                cache.put( item, item );
+                        }
+                }
+                catch( Exception ex )
+                {
+                        throw new Error( ex );
+                }
+        }
+        
+        public static ConstPool newConstPool( )
+        {
+                // const pool expects the name of a class to initialize itself
+                // but we want an empty pool
+                // so give it a bogus name, and then clear the entries afterwards
+                ConstPool pool = new ConstPool( "a" );
+                
+                ConstPoolEditor editor = new ConstPoolEditor( pool );
+                int size = pool.getSize();
+                for( int i=0; i<size-1; i++ )
+                {
+                        editor.removeLastItem();
+                }
+                
+                // make sure the pool is actually empty
+                // although, in this case "empty" means one thing in it
+                // the JVM spec says index 0 should be reserved
+                assert( pool.getSize() == 1 );
+                assert( editor.getItem( 0 ) == null );
+                assert( editor.getItem( 1 ) == null );
+                assert( editor.getItem( 2 ) == null );
+                assert( editor.getItem( 3 ) == null );
+                
+                // also, clear the cache
+                editor.getCache().clear();
+                
+                return pool;
+        }
+        
+        public String dump( )
+        {
+                StringBuilder buf = new StringBuilder();
+                for( int i=1; i<m_pool.getSize(); i++ )
+                {
+                        buf.append( String.format( "%4d", i ) );
+                        buf.append( "   " );
+                        buf.append( getItem( i ).toString() );
+                        buf.append( "\n" );
+                }
+                return buf.toString();
+        }
+}