ASM Coremod

[gargan]

Hi! I try add a invocation's method with ASM in AbstractPlayer. This work perfect in 1.6.4 but it's illegal in 1.7.2. I have a error: according to forge I modify the vanilla class! But i can do this differently!

Sorry for my english i don't speak very well english

[coolboy4531]

What do you mean its illegal in 1.7.2?

Are you trying to replace the whole class, or patch some methods/fields?

[gargan]

Yes I trying to patch getSkinUrl and getCapeUrl

 

package fr.lefgolas.pickandcraft;

 

import static org.objectweb.asm.Opcodes.ARETURN;

import static org.objectweb.asm.Opcodes.ALOAD;

import static org.objectweb.asm.Opcodes.INVOKESTATIC;

import java.util.Iterator;

import org.objectweb.asm.ClassReader;

import org.objectweb.asm.ClassWriter;

import org.objectweb.asm.tree.ClassNode;

import org.objectweb.asm.tree.InsnList;

import org.objectweb.asm.tree.InsnNode;

import org.objectweb.asm.tree.MethodInsnNode;

import org.objectweb.asm.tree.MethodNode;

import org.objectweb.asm.tree.VarInsnNode;

 

 

public class SkinClassTransformer implements net.minecraft.launchwrapper.IClassTransformer {

 

@Override

public byte[] transform(String arg0, String arg1, byte[] arg2) {

//on cherche la classe qui nous interressent. On gère les deux cas: si elle est "obscurcie" ou pas

if (arg0.equals("beu")) {

System.out.println("********* INSIDE OBFUSCATED AbstractClientPlayer TRANSFORMER ABOUT TO PATCH: " + arg0);

return patchClassASM(arg0, arg2, true);

        }

 

if (arg0.equals("net.minecraft.client.entity.AbstractClientPlayer")) {

System.out.println("********* INSIDE AbstractClientPlayer TRANSFORMER ABOUT TO PATCH: " + arg0);

return patchClassASM(arg0, arg2, false);

        }

        return arg2;

}

 

public byte[] patchClassASM(String name, byte[] bytes, boolean obfuscated) {

 

String targetMethod1Name = "", targetMethod2Name = "";

boolean ok1 = false, ok2 = false;

       

        if(obfuscated == true) {

        targetMethod1Name ="d";

targetMethod2Name = "e";

        }

        else {

        targetMethod1Name ="getSkinUrl";

targetMethod2Name = "getCapeUrl";

        }

       

 

      //on prépare la manipulation

    ClassNode classNode = new ClassNode();

        ClassReader classReader = new ClassReader(bytes);

        classReader.accept(classNode, 0);

       

 

      //Maintenant, on boucle sur toutes les méthodes déclarées dans la classe jusqu'à trouver la/les methode(s) cible(s)

        Iterator<MethodNode> methods = classNode.methods.iterator();

        while(methods.hasNext())

        {

            MethodNode m = methods.next();

            System.out.println("********* Method Name: "+m.name + " Desc:" + m.desc);

 

       

          //On vérifie si il s'agit de la méthode cible et si elle a la même signature (plus de détail ici: http://journals.ecs.soton.ac.uk/java/tutorial/native1.1/implementing/method.html)

            if ((m.name.equals(targetMethod1Name) && m.desc.equals("(Ljava/lang/String;)Ljava/lang/String;")))

            {

                System.out.println("********* Inside target method1!");

               

                //on créer une liste d'instruction pour invoquer une méthode statique

                InsnList toInject = new InsnList();

                toInject.add(new VarInsnNode(ALOAD, 0));

                //new MethodInsnNode(on déclare le type de la méthode, "le chemin de la classe", "le nom de la méthode", "sa signature")

                toInject.add(new MethodInsnNode(INVOKESTATIC, "fr.lefgolas.pickandcraft/PlayerCustom", "getURLSkinCustom", "(Ljava/lang/String;)Ljava/lang/String;"));

                toInject.add(new InsnNode(ARETURN));

               

                  // on remplace les instructions déjà présente dans la méthode par notre liste d'instruction

                  m.instructions = toInject;

                  ok1 = true;

                System.out.println("Patching Method1 Complete!");

            }

            else if ((m.name.equals(targetMethod2Name) && m.desc.equals("(Ljava/lang/String;)Ljava/lang/String;")))

            {

                System.out.println("********* Inside target2 method!");

                  InsnList toInject = new InsnList();

                   

                  toInject.add(new VarInsnNode(ALOAD, 0));

                  toInject.add(new MethodInsnNode(INVOKESTATIC, "fr.lefgolas.pickandcraft/PlayerCustom", "getURLCapeCustom", "(Ljava/lang/String;)Ljava/lang/String;"));

                  toInject.add(new InsnNode(ARETURN));

               

                  // on remplace les instructions déjà présente dans la méthode par notre liste d'instruction

                  m.instructions = toInject;

                  ok2 = true;

                System.out.println("Patching Method2 Complete!");

            }

           

            if(ok1 && ok2)

            break;

        }

       

      //on finit la manipulation

        ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES);

        classNode.accept(writer);

        return writer.toByteArray();

      }

}

 

[Jacky2611]

Do you just want to add capes?

Maybe this is what you want.....

http://www.minecraftforum.net/topic/1725536-17xlibraryforge-developer-capes-hd-cape-support/

[gargan]

No, I want also patch getSkinUrl! More over the library is complicated for that i want do! And i want patch other functions. This is why I want understand why ASM don't work

 

I would like use ASM because is most simple.

[Chibill]

I would also like to know this.

[gargan]

I feel so stupid...

tanks you very much!