From d4fa032d7d14d79af8293487598f84d40cf9e0dc Mon Sep 17 00:00:00 2001
From: Mumfrey <adam@eq2.co.uk>
Date: Fri, 25 Oct 2019 16:45:06 +0100
Subject: [PATCH] Add audit trail support for ModLauncher 4.2, update
 checkstyle

---
 build.gradle                                  |  4 +-
 checkstyle.xml                                | 32 ++++---
 .../mapping/fg3/MappingProviderTSrg.java      |  1 -
 .../mojang/MixinServiceLaunchWrapper.java     |  9 ++
 .../org/spongepowered/asm/mixin/Shadow.java   |  2 -
 .../invoke/arg/ArgsClassGenerator.java        |  9 ++
 .../transformer/InnerClassGenerator.java      |  9 ++
 .../transformer/MixinApplicatorStandard.java  | 12 +++
 .../transformer/MixinClassGenerator.java      | 16 ++++
 .../asm/mixin/transformer/MixinProcessor.java | 10 ++
 .../transformer/ext/IClassGenerator.java      |  5 +
 .../asm/service/IMixinAuditTrail.java         | 63 +++++++++++++
 .../asm/service/IMixinService.java            | 26 ++++--
 .../asm/launch/MixinLaunchPlugin.java         | 18 +++-
 .../modlauncher/MixinServiceModLauncher.java  | 17 ++++
 .../modlauncher/ModLauncherAuditTrail.java    | 92 +++++++++++++++++++
 16 files changed, 297 insertions(+), 28 deletions(-)
 create mode 100644 src/main/java/org/spongepowered/asm/service/IMixinAuditTrail.java
 create mode 100644 src/modlauncher/java/org/spongepowered/asm/service/modlauncher/ModLauncherAuditTrail.java

diff --git a/build.gradle b/build.gradle
index 8e7f1d9a..92b693e4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -154,7 +154,7 @@ dependencies {
     modlauncherCompile "org.ow2.asm:asm-tree:$modlauncherAsmVersion"
     modlauncherCompile "org.ow2.asm:asm-commons:$modlauncherAsmVersion"
     modlauncherCompile "org.ow2.asm:asm-util:$modlauncherAsmVersion"
-    modlauncherCompile ('cpw.mods:modlauncher:4.0.0') {
+    modlauncherCompile ('cpw.mods:modlauncher:4.2.0') {
         exclude module: 'log4j-core'
     }
     
@@ -220,7 +220,7 @@ checkstyle {
         "year"        : project.inceptionYear
     ]
     configFile = file("checkstyle.xml")
-    toolVersion = '8.10'
+    toolVersion = '8.24'
 }
 
 // Source compiler configuration
diff --git a/checkstyle.xml b/checkstyle.xml
index a00c9b81..030d77ac 100644
--- a/checkstyle.xml
+++ b/checkstyle.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN" "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
+<!DOCTYPE module PUBLIC "-//Checkstyle//DTD Check Configuration 1.3//EN" "https://checkstyle.org/dtds/configuration_1_3.dtd">
 
 <!--
     This configuration file was written by the eclipse-cs plugin configuration editor
@@ -18,13 +18,6 @@
       <property name="format" value="\\u00(08|09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
       <property name="message" value="Avoid using corresponding octal or Unicode escape."/>
     </module>
-    <module name="LineLength">
-      <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
-      <property name="max" value="150"/>
-    </module>
-    <module name="LineLength">
-      <property name="ignorePattern" value="^[ ]*([a-zA-Z0-9\{\}\+\|\&amp;\&quot;@\(\)\?\.\:]|//)"/>
-    </module>
     <module name="EmptyBlock">
       <property name="option" value="TEXT"/>
       <property name="tokens" value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
@@ -34,7 +27,11 @@
     <module name="RightCurly"/>
     <module name="RightCurly">
       <property name="option" value="alone"/>
-      <property name="tokens" value="CLASS_DEF,METHOD_DEF,CTOR_DEF,LITERAL_FOR,LITERAL_WHILE,STATIC_INIT,INSTANCE_INIT"/>
+      <property name="tokens" value="CLASS_DEF,METHOD_DEF,LITERAL_FOR,LITERAL_WHILE,STATIC_INIT,INSTANCE_INIT"/>
+    </module>
+    <module name="RightCurly">
+      <property name="option" value="alone_or_singleline"/>
+      <property name="tokens" value="CTOR_DEF"/>
     </module>
     <module name="WhitespaceAround">
       <property name="allowEmptyConstructors" value="true"/>
@@ -65,7 +62,6 @@
     </module>
     <module name="LocalVariableName">
       <property name="format" value="^[a-z](([a-z0-9])|([a-z0-9][a-zA-Z0-9]*))?$"/>
-      <property name="tokens" value="VARIABLE_DEF"/>
       <message key="name.invalidPattern" value="Local variable name ''{0}'' must match pattern ''{1}''."/>
     </module>
     <module name="ClassTypeParameterName">
@@ -130,9 +126,7 @@
     </module>
     <module name="FinalClass"/>
     <module name="HideUtilityClassConstructor"/>
-    <module name="TypecastParenPad">
-      <property name="tokens" value="RPAREN,TYPECAST"/>
-    </module>
+    <module name="TypecastParenPad"/>
     <module name="ConstantName">
       <property name="applyToProtected" value="false"/>
       <property name="applyToPackage" value="false"/>
@@ -142,7 +136,19 @@
     <module name="UncommentedMain"/>
     <module name="SuppressionCommentFilter"/>
   </module>
+  <module name="LineLength">
+    <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+    <property name="max" value="150"/>
+  </module>
+  <module name="LineLength">
+    <property name="ignorePattern" value="^[ ]*([a-zA-Z0-9\{\}\+\|\&amp;\&quot;@\(\)\?\.\:]|//)"/>
+  </module>
   <module name="FileTabCharacter">
     <property name="eachLine" value="true"/>
   </module>
+  <module name="SuppressWithPlainTextCommentFilter">
+    <property name="offCommentFormat" value="\*.*&lt;pre&gt;"/>
+    <property name="onCommentFormat" value="\*.*&lt;/pre&gt;"/>
+    <property name="checkFormat" value="LineLength"/>
+  </module>
 </module>
diff --git a/src/ap/java/org/spongepowered/tools/obfuscation/mapping/fg3/MappingProviderTSrg.java b/src/ap/java/org/spongepowered/tools/obfuscation/mapping/fg3/MappingProviderTSrg.java
index 91f031a3..3d35f99e 100644
--- a/src/ap/java/org/spongepowered/tools/obfuscation/mapping/fg3/MappingProviderTSrg.java
+++ b/src/ap/java/org/spongepowered/tools/obfuscation/mapping/fg3/MappingProviderTSrg.java
@@ -28,7 +28,6 @@ import java.io.File;
 import java.io.IOException;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 
 import javax.annotation.processing.Filer;
diff --git a/src/launchwrapper/java/org/spongepowered/asm/service/mojang/MixinServiceLaunchWrapper.java b/src/launchwrapper/java/org/spongepowered/asm/service/mojang/MixinServiceLaunchWrapper.java
index 707ec5c5..82a11fb5 100644
--- a/src/launchwrapper/java/org/spongepowered/asm/service/mojang/MixinServiceLaunchWrapper.java
+++ b/src/launchwrapper/java/org/spongepowered/asm/service/mojang/MixinServiceLaunchWrapper.java
@@ -54,6 +54,7 @@ import org.spongepowered.asm.service.IClassBytecodeProvider;
 import org.spongepowered.asm.service.IClassProvider;
 import org.spongepowered.asm.service.IClassTracker;
 import org.spongepowered.asm.service.ILegacyClassTransformer;
+import org.spongepowered.asm.service.IMixinAuditTrail;
 import org.spongepowered.asm.service.ITransformer;
 import org.spongepowered.asm.service.ITransformerProvider;
 import org.spongepowered.asm.service.MixinServiceAbstract;
@@ -277,6 +278,14 @@ public class MixinServiceLaunchWrapper extends MixinServiceAbstract implements I
         return this.classLoaderUtil;
     }
     
+    /* (non-Javadoc)
+     * @see org.spongepowered.asm.service.IMixinService#getAuditTrail()
+     */
+    @Override
+    public IMixinAuditTrail getAuditTrail() {
+        return null;
+    }
+    
     /* (non-Javadoc)
      * @see org.spongepowered.asm.service.IClassProvider#findClass(
      *      java.lang.String)
diff --git a/src/main/java/org/spongepowered/asm/mixin/Shadow.java b/src/main/java/org/spongepowered/asm/mixin/Shadow.java
index f30884aa..8b9418c7 100644
--- a/src/main/java/org/spongepowered/asm/mixin/Shadow.java
+++ b/src/main/java/org/spongepowered/asm/mixin/Shadow.java
@@ -39,7 +39,6 @@ import org.spongepowered.asm.mixin.transformer.throwables.InvalidMixinException;
 @Retention(RetentionPolicy.RUNTIME)
 public @interface Shadow {
 
-    // CHECKSTYLE:OFF
     /**
      * <p>In general, shadow methods can be declared using their name in the
      * target class as you would expect, however we run into a problem when we
@@ -86,7 +85,6 @@ public @interface Shadow {
      * @return the shadow prefix
      */
     public String prefix() default "shadow$";
-    // CHECKSTYLE:ON
 
     /**
      * By default, the annotation processor will attempt to locate an
diff --git a/src/main/java/org/spongepowered/asm/mixin/injection/invoke/arg/ArgsClassGenerator.java b/src/main/java/org/spongepowered/asm/mixin/injection/invoke/arg/ArgsClassGenerator.java
index f75ca478..93e6ae6d 100644
--- a/src/main/java/org/spongepowered/asm/mixin/injection/invoke/arg/ArgsClassGenerator.java
+++ b/src/main/java/org/spongepowered/asm/mixin/injection/invoke/arg/ArgsClassGenerator.java
@@ -147,6 +147,15 @@ public final class ArgsClassGenerator implements IClassGenerator {
     public ArgsClassGenerator(IConsumer<ISyntheticClassInfo> registry) {
         this.registry = registry;
     }
+    
+    /* (non-Javadoc)
+     * @see org.spongepowered.asm.mixin.transformer.ext.IClassGenerator
+     *      #getName()
+     */
+    @Override
+    public String getName() {
+        return "args";
+    }
 
     /**
      * Get (or generate) the class name for the specified descriptor. The class
diff --git a/src/main/java/org/spongepowered/asm/mixin/transformer/InnerClassGenerator.java b/src/main/java/org/spongepowered/asm/mixin/transformer/InnerClassGenerator.java
index f4b52a0f..f8731f70 100644
--- a/src/main/java/org/spongepowered/asm/mixin/transformer/InnerClassGenerator.java
+++ b/src/main/java/org/spongepowered/asm/mixin/transformer/InnerClassGenerator.java
@@ -264,6 +264,15 @@ final class InnerClassGenerator implements IClassGenerator {
         this.registry = registry;
     }
     
+    /* (non-Javadoc)
+     * @see org.spongepowered.asm.mixin.transformer.ext.IClassGenerator
+     *      #getName()
+     */
+    @Override
+    public String getName() {
+        return "inner";
+    }
+
     /**
      * @param owner Mixin which owns the original inner class
      * @param originalName Original inner class name
diff --git a/src/main/java/org/spongepowered/asm/mixin/transformer/MixinApplicatorStandard.java b/src/main/java/org/spongepowered/asm/mixin/transformer/MixinApplicatorStandard.java
index 4feb0847..70d7e2d9 100644
--- a/src/main/java/org/spongepowered/asm/mixin/transformer/MixinApplicatorStandard.java
+++ b/src/main/java/org/spongepowered/asm/mixin/transformer/MixinApplicatorStandard.java
@@ -57,6 +57,8 @@ import org.spongepowered.asm.mixin.transformer.meta.MixinMerged;
 import org.spongepowered.asm.mixin.transformer.meta.MixinRenamed;
 import org.spongepowered.asm.mixin.transformer.throwables.InvalidMixinException;
 import org.spongepowered.asm.mixin.transformer.throwables.MixinApplicatorException;
+import org.spongepowered.asm.service.IMixinAuditTrail;
+import org.spongepowered.asm.service.MixinService;
 import org.spongepowered.asm.util.Annotations;
 import org.spongepowered.asm.util.Bytecode;
 import org.spongepowered.asm.util.Bytecode.DelegateInitialiser;
@@ -241,6 +243,11 @@ class MixinApplicatorStandard {
      */
     protected final Profiler profiler = MixinEnvironment.getProfiler();
     
+    /**
+     * Audit trail (if available); 
+     */
+    protected final IMixinAuditTrail auditTrail;
+
     /**
      * Activity tracker
      */
@@ -263,6 +270,8 @@ class MixinApplicatorStandard {
         ExtensionClassExporter exporter = context.getExtensions().<ExtensionClassExporter>getExtension(ExtensionClassExporter.class);
         this.mergeSignatures = exporter.isDecompilerActive()
                 && MixinEnvironment.getCurrentEnvironment().getOption(Option.DEBUG_EXPORT_DECOMPILE_MERGESIGNATURES);
+        
+        this.auditTrail = MixinService.getService().getAuditTrail();
     }
     
     /**
@@ -276,6 +285,9 @@ class MixinApplicatorStandard {
             try {
                 this.logger.log(mixin.getLoggingLevel(), "Mixing {} from {} into {}", mixin.getName(), mixin.getParent(), this.targetName);
                 mixinContexts.add(mixin.createContextFor(this.context));
+                if (this.auditTrail != null) {
+                    this.auditTrail.onApply(this.targetName, mixin.toString());
+                }
             } catch (InvalidMixinException ex) {
                 if (mixin.isRequired()) {
                     throw ex;
diff --git a/src/main/java/org/spongepowered/asm/mixin/transformer/MixinClassGenerator.java b/src/main/java/org/spongepowered/asm/mixin/transformer/MixinClassGenerator.java
index 30f3c28a..d6b333a3 100644
--- a/src/main/java/org/spongepowered/asm/mixin/transformer/MixinClassGenerator.java
+++ b/src/main/java/org/spongepowered/asm/mixin/transformer/MixinClassGenerator.java
@@ -32,6 +32,8 @@ import org.objectweb.asm.tree.ClassNode;
 import org.spongepowered.asm.mixin.MixinEnvironment;
 import org.spongepowered.asm.mixin.transformer.ext.Extensions;
 import org.spongepowered.asm.mixin.transformer.ext.IClassGenerator;
+import org.spongepowered.asm.service.IMixinAuditTrail;
+import org.spongepowered.asm.service.MixinService;
 import org.spongepowered.asm.util.perf.Profiler;
 import org.spongepowered.asm.util.perf.Profiler.Section;
 
@@ -45,8 +47,20 @@ public class MixinClassGenerator {
      */
     static final Logger logger = LogManager.getLogger("mixin");
 
+    /**
+     * Transformer extensions
+     */
     private final Extensions extensions;
+    
+    /**
+     * Profiler 
+     */
     private final Profiler profiler;
+    
+    /**
+     * Audit trail (if available); 
+     */
+    private final IMixinAuditTrail auditTrail;
 
     /**
      * ctor 
@@ -54,6 +68,7 @@ public class MixinClassGenerator {
     MixinClassGenerator(MixinEnvironment environment, Extensions extensions) {
         this.extensions = extensions;
         this.profiler = MixinEnvironment.getProfiler();
+        this.auditTrail = MixinService.getService().getAuditTrail();
     }
 
     synchronized boolean generateClass(MixinEnvironment environment, String name, ClassNode classNode) {
@@ -67,6 +82,7 @@ public class MixinClassGenerator {
             boolean success = generator.generate(name, classNode);
             genTimer.end();
             if (success) {
+                this.auditTrail.onGenerate(name, generator.getName());
                 this.extensions.export(environment, name.replace('.', '/'), false, classNode);
                 return true;
             }
diff --git a/src/main/java/org/spongepowered/asm/mixin/transformer/MixinProcessor.java b/src/main/java/org/spongepowered/asm/mixin/transformer/MixinProcessor.java
index 87f000f4..0fa0dbb9 100644
--- a/src/main/java/org/spongepowered/asm/mixin/transformer/MixinProcessor.java
+++ b/src/main/java/org/spongepowered/asm/mixin/transformer/MixinProcessor.java
@@ -53,6 +53,7 @@ import org.spongepowered.asm.mixin.transformer.meta.MixinMerged;
 import org.spongepowered.asm.mixin.transformer.throwables.InvalidMixinException;
 import org.spongepowered.asm.mixin.transformer.throwables.MixinTransformerError;
 import org.spongepowered.asm.mixin.transformer.throwables.ReEntrantTransformerError;
+import org.spongepowered.asm.service.IMixinAuditTrail;
 import org.spongepowered.asm.service.IMixinService;
 import org.spongepowered.asm.service.MixinService;
 import org.spongepowered.asm.util.PrettyPrinter;
@@ -183,6 +184,11 @@ public class MixinProcessor {
      * Profiler 
      */
     private final Profiler profiler;
+    
+    /**
+     * Audit trail (if available); 
+     */
+    private final IMixinAuditTrail auditTrail;
 
     /**
      * Current environment 
@@ -215,6 +221,7 @@ public class MixinProcessor {
         this.postProcessor = new MixinPostProcessor(this.sessionId);
         
         this.profiler = MixinEnvironment.getProfiler();
+        this.auditTrail = this.service.getAuditTrail();
     }
 
     /**
@@ -282,6 +289,9 @@ public class MixinProcessor {
         
         try {
             if (this.postProcessor.canProcess(name)) {
+                if (this.auditTrail != null) {
+                    this.auditTrail.onPostProcess(name);
+                }
                 Section postTimer = this.profiler.begin("postprocessor");
                 success = this.postProcessor.processClass(name, targetClassNode);
                 postTimer.end();
diff --git a/src/main/java/org/spongepowered/asm/mixin/transformer/ext/IClassGenerator.java b/src/main/java/org/spongepowered/asm/mixin/transformer/ext/IClassGenerator.java
index fa6b8781..8406f0d5 100644
--- a/src/main/java/org/spongepowered/asm/mixin/transformer/ext/IClassGenerator.java
+++ b/src/main/java/org/spongepowered/asm/mixin/transformer/ext/IClassGenerator.java
@@ -30,6 +30,11 @@ import org.objectweb.asm.tree.ClassNode;
  * Base interface for class generators
  */
 public interface IClassGenerator {
+    
+    /**
+     * Get the name of this generator for logging and auditing purposes
+     */
+    public abstract String getName();
 
     /**
      * Generate (if possible) the specified class name. The generator should
diff --git a/src/main/java/org/spongepowered/asm/service/IMixinAuditTrail.java b/src/main/java/org/spongepowered/asm/service/IMixinAuditTrail.java
new file mode 100644
index 00000000..36761a2d
--- /dev/null
+++ b/src/main/java/org/spongepowered/asm/service/IMixinAuditTrail.java
@@ -0,0 +1,63 @@
+/*
+ * This file is part of Mixin, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) SpongePowered <https://www.spongepowered.org>
+ * Copyright (c) contributors
+ *
+ * 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 org.spongepowered.asm.service;
+
+/**
+ * Audit trail is responsible for logging activities during mixin application to
+ * target classes for use as debugging information later on. An audit trail
+ * service can either log audit entries internally for retrieval on crash, or
+ * can delegate to an underlying subsystem which handles this behaviour.
+ * 
+ * <p>This service component is entirely optional and services can elect to
+ * return <tt>null</tt> if the platform does not support this functionality.</p>
+ */
+public interface IMixinAuditTrail {
+    
+    /**
+     * Called when a class has a mixin applied to it by mixin.
+     * 
+     * @param className Target class name
+     * @param mixinName Mixin name
+     */
+    public abstract void onApply(String className, String mixinName);
+
+    /**
+     * Called when a class is post-processed by mixin. This is the case for
+     * synthetic inner classes (eg. switch table) and for accessor interfaces.
+     * 
+     * @param className Class being post-processed
+     */
+    public abstract void onPostProcess(String className);
+
+    /**
+     * Called when a class is generated by mixin. This is the case for fully
+     * synthetic classes such as Args and non-synthetic inner classes in mixins
+     * 
+     * @param className Class being generated
+     * @param  generatorName Name of the generator
+     */
+    public abstract void onGenerate(String className, String generatorName);
+
+}
diff --git a/src/main/java/org/spongepowered/asm/service/IMixinService.java b/src/main/java/org/spongepowered/asm/service/IMixinService.java
index b17f1024..aa5c324f 100644
--- a/src/main/java/org/spongepowered/asm/service/IMixinService.java
+++ b/src/main/java/org/spongepowered/asm/service/IMixinService.java
@@ -88,30 +88,38 @@ public interface IMixinService {
     public abstract ReEntranceLock getReEntranceLock();
     
     /**
-     * Return the class provider for this service
+     * Return the class provider for this service. <b>This component is required
+     * and services must not return <tt>null</tt>.</b>
      */
     public abstract IClassProvider getClassProvider();
     
     /**
-     * Return the class bytecode provider for this service
+     * Return the class bytecode provider for this service. <b>This component is
+     * required and services must not return <tt>null</tt>.</b>
      */
     public abstract IClassBytecodeProvider getBytecodeProvider();
     
     /**
-     * Return the transformer provider for this service. <b>Note that unlike
-     * other service components, this component is allowed to be <tt>null</tt>
-     * for services which do not support transformers, or don't support
-     * interacting with them</b>!
+     * Return the transformer provider for this service. <b>This component is
+     * optional and is allowed to be <tt>null</tt> for services which do not
+     * support transformers, or don't support interacting with them.</b>
      */
     public abstract ITransformerProvider getTransformerProvider();
     
     /**
-     * Return the class tracker for this service. <b>Note that unlike
-     * other service components, this component is allowed to be <tt>null</tt>
-     * for services which do not support this functionality</b>!
+     * Return the class tracker for this service. <b>This component is optional
+     * and is allowed to be <tt>null</tt> for services which do not support this
+     * functionality.</b>
      */
     public abstract IClassTracker getClassTracker();
     
+    /**
+     * Return the audit trail for this service. <b>This component is optional
+     * and is allowed to be <tt>null</tt> for services which do not support this
+     * functionality.</b>
+     */
+    public abstract IMixinAuditTrail getAuditTrail();
+    
     /**
      * Get additional platform agents for this service 
      */
diff --git a/src/modlauncher/java/org/spongepowered/asm/launch/MixinLaunchPlugin.java b/src/modlauncher/java/org/spongepowered/asm/launch/MixinLaunchPlugin.java
index 881a8e90..279ee4dd 100644
--- a/src/modlauncher/java/org/spongepowered/asm/launch/MixinLaunchPlugin.java
+++ b/src/modlauncher/java/org/spongepowered/asm/launch/MixinLaunchPlugin.java
@@ -31,6 +31,7 @@ import java.util.ArrayList;
 import java.util.EnumSet;
 import java.util.List;
 import java.util.Map.Entry;
+import java.util.function.Consumer;
 
 import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.Type;
@@ -40,6 +41,7 @@ import org.spongepowered.asm.service.IClassBytecodeProvider;
 import org.spongepowered.asm.service.IMixinService;
 import org.spongepowered.asm.service.MixinService;
 import org.spongepowered.asm.service.modlauncher.MixinServiceModLauncher;
+import org.spongepowered.asm.service.modlauncher.ModLauncherAuditTrail;
 
 import com.google.common.io.Resources;
 
@@ -59,7 +61,7 @@ public class MixinLaunchPlugin implements ILaunchPluginService, IClassBytecodePr
     /**
      * Class processing components
      */
-    private List<IClassProcessor> processors = new ArrayList<IClassProcessor>();
+    private final List<IClassProcessor> processors = new ArrayList<IClassProcessor>();
 
     /**
      * Mixin config names specified on the command line 
@@ -70,6 +72,8 @@ public class MixinLaunchPlugin implements ILaunchPluginService, IClassBytecodePr
     
     private MixinServiceModLauncher service;
     
+    private ModLauncherAuditTrail auditTrail;
+    
     /* (non-Javadoc)
      * @see cpw.mods.modlauncher.serviceapi.ILaunchPluginService#name()
      */
@@ -145,6 +149,7 @@ public class MixinLaunchPlugin implements ILaunchPluginService, IClassBytecodePr
             throw new IllegalStateException("Unsupported service type for ModLauncher Mixin Service");
         }
         this.service = (MixinServiceModLauncher)service;
+        this.auditTrail = (ModLauncherAuditTrail)this.service.getAuditTrail();
         synchronized (this.processors) {
             this.processors.addAll(this.service.getProcessors());
         }
@@ -152,6 +157,17 @@ public class MixinLaunchPlugin implements ILaunchPluginService, IClassBytecodePr
         this.service.onInit(this);
     }
     
+    /* (non-Javadoc)
+     * @see cpw.mods.modlauncher.serviceapi.ILaunchPluginService
+     *      #customAuditConsumer(java.lang.String, java.util.function.Consumer)
+     */
+    @Override
+    public void customAuditConsumer(String className, Consumer<String[]> auditDataAcceptor) {
+        if (this.auditTrail != null) {
+            this.auditTrail.setConsumer(className, auditDataAcceptor);
+        }
+    }
+
     @Override
     @Deprecated
     public void addResource(Path resource, String name) {
diff --git a/src/modlauncher/java/org/spongepowered/asm/service/modlauncher/MixinServiceModLauncher.java b/src/modlauncher/java/org/spongepowered/asm/service/modlauncher/MixinServiceModLauncher.java
index 0bf45dd3..c7782f6e 100644
--- a/src/modlauncher/java/org/spongepowered/asm/service/modlauncher/MixinServiceModLauncher.java
+++ b/src/modlauncher/java/org/spongepowered/asm/service/modlauncher/MixinServiceModLauncher.java
@@ -35,6 +35,7 @@ import org.spongepowered.asm.mixin.transformer.MixinTransformationHandler;
 import org.spongepowered.asm.service.IClassBytecodeProvider;
 import org.spongepowered.asm.service.IClassProvider;
 import org.spongepowered.asm.service.IClassTracker;
+import org.spongepowered.asm.service.IMixinAuditTrail;
 import org.spongepowered.asm.service.ITransformerProvider;
 import org.spongepowered.asm.service.MixinServiceAbstract;
 import org.spongepowered.asm.util.IConsumer;
@@ -73,6 +74,11 @@ public class MixinServiceModLauncher extends MixinServiceAbstract {
      * Class tracker, tracks class loads and registered invalid classes
      */
     private ModLauncherClassTracker classTracker;
+    
+    /**
+     * Audit trail adapter 
+     */
+    private ModLauncherAuditTrail auditTrail;
 
     /**
      * Environment phase consumer, TEMP
@@ -191,6 +197,17 @@ public class MixinServiceModLauncher extends MixinServiceAbstract {
         }
         return this.classTracker;
     }
+    
+    /* (non-Javadoc)
+     * @see org.spongepowered.asm.service.IMixinService#getAuditTrail()
+     */
+    @Override
+    public IMixinAuditTrail getAuditTrail() {
+        if (this.auditTrail == null) {
+            this.auditTrail = new ModLauncherAuditTrail();
+        }
+        return this.auditTrail;
+    }
 
     /**
      * Get (or create) the transformation handler
diff --git a/src/modlauncher/java/org/spongepowered/asm/service/modlauncher/ModLauncherAuditTrail.java b/src/modlauncher/java/org/spongepowered/asm/service/modlauncher/ModLauncherAuditTrail.java
new file mode 100644
index 00000000..3c08625f
--- /dev/null
+++ b/src/modlauncher/java/org/spongepowered/asm/service/modlauncher/ModLauncherAuditTrail.java
@@ -0,0 +1,92 @@
+/*
+ * This file is part of Mixin, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) SpongePowered <https://www.spongepowered.org>
+ * Copyright (c) contributors
+ *
+ * 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 org.spongepowered.asm.service.modlauncher;
+
+import java.util.function.Consumer;
+
+import org.spongepowered.asm.service.IMixinAuditTrail;
+
+/**
+ * Audit trail adapter for ModLauncher
+ */
+public class ModLauncherAuditTrail implements IMixinAuditTrail {
+    
+    private static final String APPLY_MIXIN_ACTIVITY = "APP";
+    private static final String POST_PROCESS_ACTIVITY = "DEC";
+    private static final String GENERATE_ACTIVITY = "GEN";
+    
+    /**
+     * Current audit trail class name 
+     */
+    private String currentClass;
+    
+    /**
+     * Audit trail consumer
+     */
+    private Consumer<String[]> consumer;
+
+    /**
+     * @param className current class name
+     * @param consumer audit trail consumer which sinks audit trail actions
+     */
+    public void setConsumer(String className, Consumer<String[]> consumer) {
+        this.currentClass = className;
+        this.consumer = consumer;
+    }
+    
+    /* (non-Javadoc)
+     * @see org.spongepowered.asm.service.IMixinAuditTrail#onApply(
+     *      java.lang.String, java.lang.String)
+     */
+    @Override
+    public void onApply(String className, String mixinName) {
+        this.writeActivity(className, ModLauncherAuditTrail.APPLY_MIXIN_ACTIVITY, mixinName);
+    }
+
+    /* (non-Javadoc)
+     * @see org.spongepowered.asm.service.IMixinAuditTrail#onPostProcess(
+     *      java.lang.String)
+     */
+    @Override
+    public void onPostProcess(String className) {
+        this.writeActivity(className, ModLauncherAuditTrail.POST_PROCESS_ACTIVITY);
+    }
+    
+    /* (non-Javadoc)
+     * @see org.spongepowered.asm.service.IMixinAuditTrail#onGenerate(
+     *      java.lang.String, java.lang.String)
+     */
+    @Override
+    public void onGenerate(String className, String generatorName) {
+        this.writeActivity(className, ModLauncherAuditTrail.GENERATE_ACTIVITY);
+    }
+
+    private void writeActivity(String className, String... activity) {
+        if (this.consumer != null && className.equals(this.currentClass)) {
+            this.consumer.accept(activity);
+        }
+    }
+
+}