net.malisis.core.asm.AsmHook.java Source code

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Here is the source code for net.malisis.core.asm.AsmHook.java

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/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2014 Ordinastie
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

package net.malisis.core.asm;

import java.util.ArrayList;
import java.util.HashMap;

import net.malisis.core.asm.mappings.McpMethodMapping;

import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.InsnList;
import org.objectweb.asm.tree.MethodNode;

public class AsmHook {
    private enum HookStep {
        FIND, INSERT, JUMP,
    }

    private static int END = Short.MIN_VALUE;

    private McpMethodMapping mapping;
    private boolean debug = false;

    private ArrayList<InsnList> inserts = new ArrayList<>();
    private ArrayList<InsnList> matches = new ArrayList<>();
    private ArrayList<Integer> jumps = new ArrayList<>();
    private ArrayList<HookStep> steps = new ArrayList<>();

    public AsmHook(McpMethodMapping mapping) {
        this.mapping = mapping;
    }

    public AsmHook jumpTo(InsnList match) {
        this.steps.add(HookStep.FIND);
        this.matches.add(match);
        this.jump(-1);
        return this;
    }

    public AsmHook jumpToEnd() {
        return this.jump(END);
    }

    public AsmHook jumpAfter(InsnList match) {
        this.jumpTo(match);
        this.jump(match.size());
        return this;
    }

    public AsmHook insert(AbstractInsnNode insert) {
        InsnList list = new InsnList();
        list.add(insert);
        return insert(list);
    }

    public AsmHook insert(InsnList insert) {
        this.steps.add(HookStep.INSERT);
        this.inserts.add(insert);
        return this;
    }

    public AsmHook jump(int jump) {
        this.steps.add(HookStep.JUMP);
        this.jumps.add(jump);
        return this;
    }

    public AsmHook previous() {
        return jump(-1);
    }

    public AsmHook next() {
        return jump(1);
    }

    public AsmHook debug() {
        this.debug = true;
        return this;
    }

    public boolean walkSteps(MethodNode methodNode) {
        int index = 0;
        for (HookStep step : steps) {
            switch (step) {
            case FIND:
                InsnList match = matches.remove(0);
                AbstractInsnNode node = AsmUtils.findInstruction(methodNode, match);
                if (node == null)
                    return false;
                else
                    index = methodNode.instructions.indexOf(node);
                break;
            case INSERT:
                InsnList insert = inserts.remove(0);
                index += insert.size();
                methodNode.instructions.insert(methodNode.instructions.get(index - insert.size()), insert);
                break;
            case JUMP:
                int jump = jumps.remove(0);
                if (jump == END)
                    index = methodNode.instructions.size() - 1;
                else
                    index += jump;
            default:
                break;
            }
        }

        return true;
    }

    public void register(HashMap<String, ArrayList<AsmHook>> listHooks) {
        ArrayList<AsmHook> hooks = listHooks.get(mapping.getTargetClass());
        if (hooks == null)
            hooks = new ArrayList<AsmHook>();
        hooks.add(this);
        listHooks.put(mapping.getTargetClass(), hooks);
    }

    public String getTargetClass() {
        return mapping.getTargetClass();
    }

    public String getMethodName() {
        return mapping.getName();
    }

    public String getMethodDescriptor() {
        return mapping.getDescriptor();
    }

    public boolean isDebug() {
        return debug;
    }

}