From 0d1a2f2af343bbd6907a74607ff156eefa6cfcc3 Mon Sep 17 00:00:00 2001
From: tterrag <tterrag1098@gmail.com>
Date: Thu, 17 Jan 2019 13:11:54 -0500
Subject: [PATCH] Add utilities that RuntimeEnumExtender expects to exist

---
 .../common/asm/RuntimeEnumExtender.java       |  4 +-
 .../net/minecraftforge/fml/UnsafeHacks.java   | 39 +++++++++++++++----
 2 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/src/fmllauncher/java/net/minecraftforge/common/asm/RuntimeEnumExtender.java b/src/fmllauncher/java/net/minecraftforge/common/asm/RuntimeEnumExtender.java
index 2e7cc1fe7e..2188ce22bb 100644
--- a/src/fmllauncher/java/net/minecraftforge/common/asm/RuntimeEnumExtender.java
+++ b/src/fmllauncher/java/net/minecraftforge/common/asm/RuntimeEnumExtender.java
@@ -45,7 +45,7 @@ public class RuntimeEnumExtender implements ILaunchPluginService {
     private final Type ENUM = Type.getType(Enum.class);
     private final Type ARRAY_UTILS = Type.getType("Lorg/apache/commons/lang3/ArrayUtils;"); //Don't directly reference this to prevent class loading.
     private final String ADD_DESC = Type.getMethodDescriptor(Type.getType(Object[].class), Type.getType(Object[].class), Type.getType(Object.class));
-    private final Type ENUM_HELPER = Type.getType("Lnet/minecraftforge/common/util/EnumHelper;"); //Again, not direct reference to prevent class loading.
+    private final Type UNSAFE_HACKS = Type.getType("Lnet/minecraftforge/fml/UnsafeHacks;"); //Again, not direct reference to prevent class loading.
     private final String CLEAN_DESC = Type.getMethodDescriptor(Type.VOID_TYPE, Type.getType(Class.class));
     private final String NAME_DESC = Type.getMethodDescriptor(STRING);
     private final String EQUALS_DESC = Type.getMethodDescriptor(Type.BOOLEAN_TYPE, STRING);
@@ -181,7 +181,7 @@ public class RuntimeEnumExtender implements ILaunchPluginService {
                 ins.putstatic(classType.getInternalName(), values.name, values.desc);
                 //EnumHelper.cleanEnumCache(ThisType.class)
                 ins.visitLdcInsn(classType);
-                ins.invokestatic(ENUM_HELPER.getInternalName(), "cleanEnumCache", CLEAN_DESC, false);
+                ins.invokestatic(UNSAFE_HACKS.getInternalName(), "cleanEnumCache", CLEAN_DESC, false);
                 //return ret
                 ins.load(vars, classType);
                 ins.areturn(classType);
diff --git a/src/main/java/net/minecraftforge/fml/UnsafeHacks.java b/src/main/java/net/minecraftforge/fml/UnsafeHacks.java
index a91411e56c..80ec3a5d8f 100644
--- a/src/main/java/net/minecraftforge/fml/UnsafeHacks.java
+++ b/src/main/java/net/minecraftforge/fml/UnsafeHacks.java
@@ -19,14 +19,17 @@
 
 package net.minecraftforge.fml;
 
+import java.lang.reflect.Field;
+import java.util.Optional;
+
 import sun.misc.Unsafe;
 
-import java.lang.reflect.Field;
-
+@SuppressWarnings("restriction")
 public class UnsafeHacks
 {
     private static final Unsafe UNSAFE;
-    static {
+    static 
+    {
         try
         {
             final Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");
@@ -40,11 +43,11 @@ public class UnsafeHacks
     }
 
     @SuppressWarnings("unchecked")
-    public static <T> T newInstance(Class<T> packetClass)
+    public static <T> T newInstance(Class<T> clazz)
     {
         try
         {
-            return (T) UNSAFE.allocateInstance(packetClass);
+            return (T) UNSAFE.allocateInstance(clazz);
         }
         catch (InstantiationException e)
         {
@@ -53,15 +56,16 @@ public class UnsafeHacks
     }
 
     @SuppressWarnings("unchecked")
-    public static <T> T getField(Field field, Object object) {
+    public static <T> T getField(Field field, Object object) 
+    {
         final long l = UNSAFE.objectFieldOffset(field);
         return (T) UNSAFE.getObject(object, l);
     }
 
-    public static void setField(Field data, Object object, Object buffer)
+    public static void setField(Field data, Object object, Object value)
     {
         long offset = UNSAFE.objectFieldOffset(data);
-        UNSAFE.putObject(object, offset, buffer);
+        UNSAFE.putObject(object, offset, value);
     }
 
     public static int getIntField(Field f, Object obj)
@@ -75,4 +79,23 @@ public class UnsafeHacks
         long offset = UNSAFE.objectFieldOffset(data);
         UNSAFE.putInt(object, offset, value);
     }
+    
+    // Make sure we don't crash if any future versions change field names
+    private static Optional<Field> findField(Class<?> clazz, String name)
+    {
+        for (Field f : clazz.getDeclaredFields())
+        {
+            if (f.getName().equals(name))
+            {
+                return Optional.of(f);
+            }
+        }
+        return Optional.empty();
+    }
+
+    public static void cleanEnumCache(Class<? extends Enum<?>> enumClass) throws Exception
+    {
+        findField(Class.class, "enumConstantDirectory").ifPresent(f -> setField(f, enumClass, null));
+        findField(Class.class, "enumConstants").ifPresent(f -> setField(f, enumClass, null));
+    }
 }