From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Zach Brown <zach@zachbr.io>
Date: Wed, 3 Oct 2018 20:09:18 -0400
Subject: [PATCH] Hook into CB plugin rewrites

Allows us to do fun stuff like rewrite the OBC util fastutil location to
our own relocation. Also lets us rewrite NMS calls for when we're
debugging in an IDE pre-relocate.

diff --git a/src/main/java/org/bukkit/craftbukkit/util/Commodore.java b/src/main/java/org/bukkit/craftbukkit/util/Commodore.java
index a679133a3de51e26eb19932ece9ade292879aefd..d5330d1dff2d02e585eba3ec7c48bf261cdce8ef 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/Commodore.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/Commodore.java
@@ -6,7 +6,9 @@ import java.io.FileOutputStream;
 import java.io.InputStream;
 import java.util.Arrays;
 import java.util.Enumeration;
+import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Map;
 import java.util.Set;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
@@ -20,10 +22,15 @@ import org.bukkit.plugin.AuthorNagException;
 import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.ClassVisitor;
 import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.FieldVisitor;
+import org.objectweb.asm.Handle;
+import org.objectweb.asm.Label;
 import org.objectweb.asm.MethodVisitor;
 import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.Type;
 
+import javax.annotation.Nonnull;
+
 /**
  * This file is imported from Commodore.
  *
@@ -46,6 +53,42 @@ public class Commodore
             "org/bukkit/inventory/ItemStack (I)V setTypeId"
     ) );
 
+    // Paper start - Plugin rewrites
+    private static final Map<String, String> SEARCH_AND_REMOVE = initReplacementsMap();
+    private static Map<String, String> initReplacementsMap()
+    {
+        Map<String, String> getAndRemove = new HashMap<>();
+        // Be wary of maven shade's relocations
+        getAndRemove.put( "org/bukkit/".concat( "craftbukkit/libs/it/unimi/dsi/fastutil/" ), "org/bukkit/".concat( "craftbukkit/libs/" ) ); // Remap fastutil to our location
+
+        if ( Boolean.getBoolean( "debug.rewriteForIde" ) )
+        {
+            // unversion incoming calls for pre-relocate debug work
+            final String NMS_REVISION_PACKAGE = "v1_16_R3/";
+
+            getAndRemove.put( "net/minecraft/".concat( "server/" + NMS_REVISION_PACKAGE ), NMS_REVISION_PACKAGE );
+            getAndRemove.put( "org/bukkit/".concat( "craftbukkit/" + NMS_REVISION_PACKAGE ), NMS_REVISION_PACKAGE );
+        }
+
+        return getAndRemove;
+    }
+
+    @Nonnull
+    private static String getOriginalOrRewrite(@Nonnull String original)
+    {
+        String rewrite = null;
+        for ( Map.Entry<String, String> entry : SEARCH_AND_REMOVE.entrySet() )
+        {
+            if ( original.contains( entry.getKey() ) )
+            {
+                rewrite = original.replace( entry.getValue(), "" );
+            }
+        }
+
+        return rewrite != null ? rewrite : original;
+    }
+    // Paper end
+
     public static void main(String[] args)
     {
         OptionParser parser = new OptionParser();
@@ -130,15 +173,86 @@ public class Commodore
 
         cr.accept( new ClassVisitor( Opcodes.ASM9, cw )
         {
+            // Paper start - Rewrite plugins
+            @Override
+            public FieldVisitor visitField(int access, String name, String desc, String signature, Object value)
+            {
+                desc = getOriginalOrRewrite( desc );
+                if ( signature != null ) {
+                    signature = getOriginalOrRewrite( signature );
+                }
+
+                return super.visitField( access, name, desc, signature, value) ;
+            }
+            // Paper end
+
             @Override
             public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions)
             {
                 return new MethodVisitor( api, super.visitMethod( access, name, desc, signature, exceptions ) )
                 {
+                    // Paper start - Plugin rewrites
+                    @Override
+                    public void visitInvokeDynamicInsn(String name, String desc, Handle bootstrapMethodHandle, Object... bootstrapMethodArguments)
+                    {
+                        // Paper start - Rewrite plugins
+                        name = getOriginalOrRewrite( name );
+                        if ( desc != null )
+                        {
+                            desc = getOriginalOrRewrite( desc );
+                        }
+                        // Paper end
+
+                        super.visitInvokeDynamicInsn( name, desc, bootstrapMethodHandle, bootstrapMethodArguments );
+                    }
+
+                    @Override
+                    public void visitTypeInsn(int opcode, String type)
+                    {
+                        type = getOriginalOrRewrite( type );
+
+                        super.visitTypeInsn( opcode, type );
+                    }
+
+                    @Override
+                    public void visitFrame(int type, int nLocal, Object[] local, int nStack, Object[] stack) {
+                        for ( int i = 0; i < local.length; i++ )
+                        {
+                            if ( !( local[i] instanceof String ) ) { continue; }
+
+                            local[i] = getOriginalOrRewrite( (String) local[i] );
+                        }
+
+                        for ( int i = 0; i < stack.length; i++ )
+                        {
+                            if ( !( stack[i] instanceof String ) ) { continue; }
+
+                            stack[i] = getOriginalOrRewrite( (String) stack[i] );
+                        }
+
+                        super.visitFrame( type, nLocal, local, nStack, stack );
+                    }
+
+                    @Override
+                    public void visitLocalVariable(String name, String descriptor, String signature, Label start, Label end, int index)
+                    {
+                        descriptor = getOriginalOrRewrite( descriptor );
+
+                        super.visitLocalVariable( name, descriptor, signature, start, end, index );
+                    }
+                    // Paper end
 
                     @Override
                     public void visitFieldInsn(int opcode, String owner, String name, String desc)
                     {
+                        // Paper start - Rewrite plugins
+                        owner = getOriginalOrRewrite( owner );
+                        if ( desc != null )
+                        {
+                            desc = getOriginalOrRewrite( desc );
+                        }
+                        // Paper end
+
                         if ( owner.equals( "org/bukkit/block/Biome" ) )
                         {
                             switch ( name )
@@ -306,6 +420,14 @@ public class Commodore
                             return;
                         }
 
+                        // Paper start - Rewrite plugins
+                        owner = getOriginalOrRewrite( owner) ;
+                        if (desc != null)
+                        {
+                            desc = getOriginalOrRewrite(desc);
+                        }
+                        // Paper end
+
                         if ( modern )
                         {
                             if ( owner.equals( "org/bukkit/Material" ) )