Paper/patches/server/0256-Hook-into-CB-plugin-rewrites.patch

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 6a661bbae8bc35a4c3b4bb7e86dd77a7575fdd97..31714ce05b1023b82e96b36ba52254b4e3e948f2 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/Commodore.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/Commodore.java
@@ -7,6 +7,7 @@ import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Enumeration;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -15,6 +16,7 @@ import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import java.util.jar.JarOutputStream;
 import java.util.zip.ZipEntry;
+import javax.annotation.Nonnull;
 import joptsimple.OptionParser;
 import joptsimple.OptionSet;
 import joptsimple.OptionSpec;
@@ -23,7 +25,9 @@ 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;
@@ -51,6 +55,40 @@ public class Commodore {
             "org/spigotmc/event/entity/EntityDismountEvent", "org/bukkit/event/entity/EntityDismountEvent"
     );
 
+    // 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
+
+        final java.util.jar.Manifest manifest = io.papermc.paper.util.JarManifests.manifest(Commodore.class);
+        if (Boolean.getBoolean( "debug.rewriteForIde") && manifest != null)
+        {
+            // unversion incoming calls for pre-relocate debug work
+            final String NMS_REVISION_PACKAGE = "v" + manifest.getMainAttributes().getValue("CraftBukkit-Package-Version") + "/";
+
+            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 - Plugin rewrites
+
     public static void main(String[] args) {
         OptionParser parser = new OptionParser();
         OptionSpec<File> inputFlag = parser.acceptsAll(Arrays.asList("i", "input")).withRequiredArg().ofType(File.class).required();
@@ -118,12 +156,67 @@ public class Commodore {
         ClassWriter cw = new ClassWriter(cr, 0);
 
         cr.accept(new ClassRemapper(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(this.api, super.visitMethod(access, name, desc, signature, exceptions)) {
 
+                    // Paper start - Plugin rewrites
+                    @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) {
                                 case "NETHER":
@@ -278,6 +371,10 @@ public class Commodore {
                         }
 
                         // Paper start - Rewrite plugins
+                        owner = getOriginalOrRewrite(owner) ;
+                        if (desc != null) {
+                            desc = getOriginalOrRewrite(desc);
+                        }
                         if ((owner.equals("org/bukkit/OfflinePlayer") || owner.equals("org/bukkit/entity/Player")) && name.equals("getPlayerProfile") && desc.equals("()Lorg/bukkit/profile/PlayerProfile;")) {
                             super.visitMethodInsn(opcode, owner, name, "()Lcom/destroystokyo/paper/profile/PlayerProfile;", itf);
                             return;
@@ -374,6 +471,13 @@ public class Commodore {
 
                     @Override
                     public void visitLdcInsn(Object value) {
+                        // Paper start
+                        if (value instanceof Type type) {
+                            if (type.getSort() == Type.OBJECT || type.getSort() == Type.ARRAY) {
+                                value = Type.getType(getOriginalOrRewrite(type.getDescriptor()));
+                            }
+                        }
+                        // Paper end
                         if (value instanceof String && ((String) value).equals("com.mysql.jdbc.Driver")) {
                             super.visitLdcInsn("com.mysql.cj.jdbc.Driver");
                             return;
@@ -384,6 +488,14 @@ public class Commodore {
 
                     @Override
                     public void visitInvokeDynamicInsn(String name, String descriptor, Handle bootstrapMethodHandle, Object... bootstrapMethodArguments) {
+                        // Paper start - Rewrite plugins
+                        name = getOriginalOrRewrite(name);
+                        if (descriptor != null) {
+                            descriptor = getOriginalOrRewrite(descriptor);
+                        }
+                        final String fName = name;
+                        final String fDescriptor = descriptor;
+                        // Paper end - Rewrite plugins
                         if (bootstrapMethodHandle.getOwner().equals("java/lang/invoke/LambdaMetafactory")
                                 && bootstrapMethodHandle.getName().equals("metafactory") && bootstrapMethodArguments.length == 3) {
                             Type samMethodType = (Type) bootstrapMethodArguments[0];
@@ -400,7 +512,7 @@ public class Commodore {
                                 methodArgs.add(new Handle(newOpcode, newOwner, newName, newDescription, newItf));
                                 methodArgs.add(newInstantiated);
 
-                                super.visitInvokeDynamicInsn(name, descriptor, bootstrapMethodHandle, methodArgs.toArray(Object[]::new));
+                                super.visitInvokeDynamicInsn(fName, fDescriptor, bootstrapMethodHandle, methodArgs.toArray(Object[]::new)); // Paper - use final local vars
                             }, implMethod.getTag(), implMethod.getOwner(), implMethod.getName(), implMethod.getDesc(), implMethod.isInterface(), samMethodType, instantiatedMethodType);
                             return;
                         }