From ebc4b49390d4a43cba3a9a2d5621d31ccb1541e3 Mon Sep 17 00:00:00 2001
From: Juuxel <6596629+Juuxel@users.noreply.github.com>
Date: Thu, 3 Dec 2020 18:08:43 +0200
Subject: [PATCH] Remap mod dependencies + their coremods and ATs

---
 README.md                                     | 75 ++++++++++++++++++-
 .../providers/MinecraftPatchedProvider.java   |  5 +-
 .../net/fabricmc/loom/util/ModProcessor.java  | 13 +++-
 3 files changed, 85 insertions(+), 8 deletions(-)

diff --git a/README.md b/README.md
index 968e67ff..aec45731 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,73 @@
-# fabric-loom
-Gradle plugin for Fabric
+# Forgified Loom
 
-Usage: `gradlew setup idea`
-(Use `./gradle` on macOS and Linux)
+A fork of [Fabric Loom](https://github.com/FabricMC/fabric-loom) that supports the Forge modding toolchain.
 
+Note that if ForgeGradle works fine for you, *use it*.
+This is not meant to be a complete replacement for ForgeGradle,
+and there are probably many bugs and limitations here that FG doesn't have.
+
+## Usage
+
+Starting with a Fabric project similar to the example mod,
+switch your Loom to this fork, like with [Chocohead's Loom fork](https://github.com/Chocohead/Fabric-Loom/).
+
+`settings.gradle`:
+```diff
+pluginManagement {
+	repositories {
+		jcenter()
+		maven {
+			name = 'Fabric'
+			url = 'https://maven.fabricmc.net/'
+		}
+		gradlePluginPortal()
++		maven {
++			name = 'Jitpack'
++			url = 'https://jitpack.io'
++		}
+	}
++	resolutionStrategy {
++		eachPlugin {
++			if (requested.id.id == "fabric-loom" && requested.version?.endsWith("-SNAPSHOT") != true) {
++				useModule("com.github.Juuxel.fabric-loom:fabric-loom:${requested.version}")
++			}
++		}
++	}
+}
+```
+`build.gradle`:
+```diff
+plugins {
+-	id 'fabric-loom' version '0.5-SNAPSHOT'
++	id 'fabric-loom' version '<commit hash here>'
+}
+```
+
+Then you need to set `loom.forge = true` in your `gradle.properties`,
+and add the Forge dependency:
+
+```groovy
+forge "net.minecraftforge:forge:1.16.4-35.1.7"
+```
+
+You also need to remove the Fabric Loader and Fabric API dependencies.
+You should also remove any access wideners and replace them with a Forge AT.
+
+### Mixins
+
+Mixins are used with a property in the `loom` block in build.gradle:
+
+```groovy
+loom {
+	mixinConfig = "mymod.mixins.json"
+}
+```
+
+## Limitations
+
+- Launching via IDE run configs doesn't work on Eclipse or VSCode.
+- You have to use Gradle 5, like with FG. I've reused it as a library
+  in some places. 
+- The srg -> yarn remapper used for coremod class names is *really* simple,
+  and might break with coremods that have multiple class names per line.
+- Mod dependencies (apart from Forge itself) aren't remapped properly yet.
diff --git a/src/main/java/net/fabricmc/loom/providers/MinecraftPatchedProvider.java b/src/main/java/net/fabricmc/loom/providers/MinecraftPatchedProvider.java
index 4d41c861..614ac3cf 100644
--- a/src/main/java/net/fabricmc/loom/providers/MinecraftPatchedProvider.java
+++ b/src/main/java/net/fabricmc/loom/providers/MinecraftPatchedProvider.java
@@ -48,7 +48,6 @@ import net.minecraftforge.binarypatcher.ConsoleTool;
 import net.minecraftforge.gradle.mcp.util.MCPRuntime;
 import net.minecraftforge.gradle.mcp.util.MCPWrapper;
 import org.apache.commons.io.FileUtils;
-import org.apache.commons.lang3.ArrayUtils;
 import org.gradle.api.Project;
 import org.gradle.api.logging.Logger;
 import org.gradle.api.plugins.JavaPluginConvention;
@@ -218,7 +217,9 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 			};
 
 			if (modAt != null) {
-				args = ArrayUtils.addAll(args, "--atFile", modAt.getAbsolutePath());
+				args = Arrays.copyOf(args, args.length + 2);
+				args[args.length - 2] = "--atFile";
+				args[args.length - 1] = modAt.getAbsolutePath();
 			}
 
 			TransformerProcessor.main(args);
diff --git a/src/main/java/net/fabricmc/loom/util/ModProcessor.java b/src/main/java/net/fabricmc/loom/util/ModProcessor.java
index 1932f21f..0cac7fc3 100644
--- a/src/main/java/net/fabricmc/loom/util/ModProcessor.java
+++ b/src/main/java/net/fabricmc/loom/util/ModProcessor.java
@@ -59,6 +59,9 @@ import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.providers.MappingsProvider;
 import net.fabricmc.loom.providers.MinecraftMappedProvider;
 import net.fabricmc.loom.processors.dependency.ModDependencyInfo;
+import net.fabricmc.loom.util.srg.AtRemapper;
+import net.fabricmc.loom.util.srg.CoreModClassRemapper;
+import net.fabricmc.mapping.tree.TinyTree;
 import net.fabricmc.tinyremapper.TinyRemapper;
 import net.fabricmc.tinyremapper.InputTag;
 import net.fabricmc.tinyremapper.OutputConsumerPath;
@@ -129,7 +132,7 @@ public class ModProcessor {
 
 	private static void remapJars(Project project, List<ModDependencyInfo> processList) throws IOException {
 		LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
-		String fromM = "intermediary";
+		String fromM = extension.isForge() ? "srg" : "intermediary";
 		String toM = "named";
 
 		MinecraftMappedProvider mappedProvider = extension.getMinecraftMappedProvider();
@@ -142,8 +145,9 @@ public class ModProcessor {
 
 		project.getLogger().lifecycle(":remapping " + remapList.size() + " mods (TinyRemapper, " + fromM + " -> " + toM + ")");
 
+		TinyTree mappings = extension.isForge() ? mappingsProvider.getMappingsWithSrg() : mappingsProvider.getMappings();
 		TinyRemapper remapper = TinyRemapper.newRemapper()
-						.withMappings(TinyRemapperMappingsHelper.create(mappingsProvider.getMappings(), fromM, toM, false))
+						.withMappings(TinyRemapperMappingsHelper.create(mappings, fromM, toM, false))
 						.renameInvalidLocals(false)
 						.build();
 
@@ -196,6 +200,11 @@ public class ModProcessor {
 			if (accessWidener != null) {
 				ZipUtil.replaceEntry(info.getRemappedOutput(), info.getAccessWidener(), accessWidener);
 			}
+
+			if (extension.isForge()) {
+				AtRemapper.remap(info.getRemappedOutput().toPath(), mappings);
+				CoreModClassRemapper.remapJar(info.getRemappedOutput().toPath(), mappings, project.getLogger());
+			}
 		}
 	}