Fix #47, Fix #48

Signed-off-by: shedaniel <daniel@shedaniel.me>

12 files changed, 216 insertions, 93 deletions

diff --git a/src/main/java/net/fabricmc/loom/configuration/mods/ModProcessor.java b/src/main/java/net/fabricmc/loom/configuration/mods/ModProcessor.java
index bb3f839e..7e155ff4 100644
--- a/src/main/java/net/fabricmc/loom/configuration/mods/ModProcessor.java
+++ b/src/main/java/net/fabricmc/loom/configuration/mods/ModProcessor.java
@@ -148,7 +148,7 @@ public class ModProcessor {
 		Stopwatch stopwatch = Stopwatch.createStarted();
 		project.getLogger().lifecycle(":remapping " + remapList.size() + " mods (TinyRemapper, " + fromM + " -> " + toM + ")");
 
-		MemoryMappingTree mappings = extension.isForge() ? mappingsProvider.getMappingsWithSrg() : mappingsProvider.getMappings();
+		MemoryMappingTree mappings = (fromM.equals("srg") || toM.equals("srg")) && extension.isForge() ? mappingsProvider.getMappingsWithSrg() : mappingsProvider.getMappings();
 		LoggerFilter.replaceSystemOut();
 		TinyRemapper remapper = TinyRemapper.newRemapper()
 				.logger(project.getLogger()::lifecycle)
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/forge/FieldMigratedMappingsProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/forge/FieldMigratedMappingsProvider.java
index 13d3e62f..238bac2d 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/forge/FieldMigratedMappingsProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/forge/FieldMigratedMappingsProvider.java
@@ -114,7 +114,7 @@ public class FieldMigratedMappingsProvider extends MappingsProviderImpl {
 		if (getExtension().shouldGenerateSrgTiny()) {
 			if (Files.notExists(rawTinyMappingsWithSrg) || isRefreshDeps()) {
 				// Merge tiny mappings with srg
-				SrgMerger.mergeSrg(getProject().getLogger(), this::getMojmapSrgFileIfPossible, getRawSrgFile(), rawTinyMappings, rawTinyMappingsWithSrg, true);
+				SrgMerger.mergeSrg(getProject().getLogger(), null, getRawSrgFile(), rawTinyMappings, rawTinyMappingsWithSrg, true);
 			}
 		}
 
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/forge/MinecraftPatchedProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/forge/MinecraftPatchedProvider.java
index 5de6e5f3..36924802 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/forge/MinecraftPatchedProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/forge/MinecraftPatchedProvider.java
@@ -96,6 +96,7 @@ import net.fabricmc.loom.util.TinyRemapperHelper;
 import net.fabricmc.loom.util.function.FsPathConsumer;
 import net.fabricmc.loom.util.srg.InnerClassRemapper;
 import net.fabricmc.loom.util.srg.SpecialSourceExecutor;
+import net.fabricmc.loom.util.srg.SrgMerger;
 import net.fabricmc.mappingio.tree.MemoryMappingTree;
 
 public class MinecraftPatchedProvider extends DependencyProvider {
@@ -308,7 +309,14 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 
 	private TinyRemapper buildRemapper(Path input) throws IOException {
 		Path[] libraries = TinyRemapperHelper.getMinecraftDependencies(getProject());
-		MemoryMappingTree mappingsWithSrg = getExtension().getMappingsProvider().getMappingsWithSrg();
+		MemoryMappingTree mappingsWithSrg;
+
+		if (getExtension().isForgeAndOfficial()) {
+			mappingsWithSrg = SrgMerger.mergeSrg(getProject().getLogger(), getExtension().getMappingsProvider()::getMojmapSrgFileIfPossible, getExtension().getSrgProvider().getMergedMojangTrimmed(), getExtension().getMappingsProvider().tinyMappings, true);
+		} else {
+			mappingsWithSrg = getExtension().getMappingsProvider().getMappingsWithSrg();
+		}
+
 		TinyRemapper remapper = TinyRemapper.newRemapper()
 				.logger(getProject().getLogger()::lifecycle)
 				.logUnknownInvokeDynamic(false)
@@ -355,7 +363,7 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 
 	private Path getToSrgMappings() throws IOException {
 		if (getExtension().getSrgProvider().isTsrgV2()) {
-			return getExtension().getSrgProvider().getMergedMojang();
+			return getExtension().getSrgProvider().getMergedMojangRaw();
 		} else {
 			return getExtension().getMcpConfigProvider().getMappings();
 		}
@@ -483,6 +491,7 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 		List<File> toDelete = new ArrayList<>();
 		String atDependency = Constants.Dependencies.ACCESS_TRANSFORMERS + Constants.Dependencies.Versions.ACCESS_TRANSFORMERS;
 		FileCollection classpath = DependencyDownloader.download(getProject(), atDependency);
+		Stopwatch stopwatch = Stopwatch.createStarted();
 
 		logger.lifecycle(":access transforming minecraft");
 
@@ -537,6 +546,8 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 		for (File file : toDelete) {
 			file.delete();
 		}
+
+		logger.lifecycle(":access transformed minecraft in " + stopwatch.stop());
 	}
 
 	public enum Environment {
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/forge/SrgProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/forge/SrgProvider.java
index 63e5cdd3..87cb1fdb 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/forge/SrgProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/forge/SrgProvider.java
@@ -28,6 +28,7 @@ import java.io.BufferedReader;
 import java.io.BufferedWriter;
 import java.io.File;
 import java.io.IOException;
+import java.io.PrintStream;
 import java.io.StringReader;
 import java.io.UncheckedIOException;
 import java.net.URI;
@@ -38,13 +39,20 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
 import java.nio.file.StandardOpenOption;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.function.Consumer;
 
+import com.google.common.base.Stopwatch;
 import com.google.common.collect.ImmutableMap;
 import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.output.NullOutputStream;
 import org.gradle.api.Project;
+import org.gradle.api.logging.LogLevel;
+import org.gradle.api.logging.configuration.ShowStacktrace;
 
 import net.fabricmc.loom.LoomGradleExtension;
+import net.fabricmc.loom.LoomGradlePlugin;
 import net.fabricmc.loom.api.mappings.layered.MappingsNamespace;
 import net.fabricmc.loom.configuration.DependencyProvider;
 import net.fabricmc.loom.configuration.providers.mappings.GradleMappingContext;
@@ -55,14 +63,18 @@ import net.fabricmc.loom.util.srg.Tsrg2Utils;
 import net.fabricmc.loom.util.srg.Tsrg2Writer;
 import net.fabricmc.mappingio.MappingReader;
 import net.fabricmc.mappingio.MappingVisitor;
+import net.fabricmc.mappingio.adapter.ForwardingMappingVisitor;
 import net.fabricmc.mappingio.tree.MappingTree;
 import net.fabricmc.mappingio.tree.MemoryMappingTree;
 
 public class SrgProvider extends DependencyProvider {
 	private Path srg;
 	private Boolean isTsrgV2;
+	private Path mergedMojangRaw;
 	private Path mergedMojang;
 	private Path mergedMojangTrimmed;
+	private static Path mojmapTsrg;
+	private static Path mojmapTsrg2;
 
 	public SrgProvider(Project project) {
 		super(project);
@@ -85,7 +97,18 @@ public class SrgProvider extends DependencyProvider {
 		}
 
 		if (isTsrgV2) {
-			if (!Files.exists(mergedMojang) || !Files.exists(mergedMojangTrimmed) || isRefreshDeps()) {
+			if (!Files.exists(mergedMojangRaw) || !Files.exists(mergedMojang) || !Files.exists(mergedMojangTrimmed) || isRefreshDeps()) {
+				Stopwatch stopwatch = Stopwatch.createStarted();
+				getProject().getLogger().lifecycle(":merging mappings (InstallerTools, srg + mojmap)");
+				PrintStream out = System.out;
+				PrintStream err = System.err;
+
+				if (getProject().getGradle().getStartParameter().getLogLevel().compareTo(LogLevel.LIFECYCLE) >= 0) {
+					System.setOut(new PrintStream(NullOutputStream.NULL_OUTPUT_STREAM));
+					System.setErr(new PrintStream(NullOutputStream.NULL_OUTPUT_STREAM));
+				}
+
+				Files.deleteIfExists(mergedMojangRaw);
 				Files.deleteIfExists(mergedMojang);
 				net.minecraftforge.installertools.ConsoleTool.main(new String[] {
 						"--task",
@@ -93,14 +116,15 @@ public class SrgProvider extends DependencyProvider {
 						"--left",
 						getSrg().toAbsolutePath().toString(),
 						"--right",
-						getMojmapTsrg(getProject(), getExtension()).toAbsolutePath().toString(),
+						getMojmapTsrg2(getProject(), getExtension()).toAbsolutePath().toString(),
 						"--classes",
 						"--output",
-						mergedMojang.toAbsolutePath().toString()
+						mergedMojangRaw.toAbsolutePath().toString()
 				});
 
 				MemoryMappingTree tree = new MemoryMappingTree();
-				MappingReader.read(new StringReader(FileUtils.readFileToString(mergedMojang.toFile(), StandardCharsets.UTF_8)), tree);
+				MappingReader.read(new StringReader(FileUtils.readFileToString(mergedMojangRaw.toFile(), StandardCharsets.UTF_8)), new FieldDescWrappingVisitor(tree));
+				Files.writeString(mergedMojang, Tsrg2Writer.serialize(tree), StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
 
 				for (MappingTree.ClassMapping classDef : tree.getClasses()) {
 					for (MappingTree.MethodMapping methodDef : classDef.getMethods()) {
@@ -109,13 +133,60 @@ public class SrgProvider extends DependencyProvider {
 				}
 
 				Files.writeString(mergedMojangTrimmed, Tsrg2Writer.serialize(tree), StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
+
+				if (getProject().getGradle().getStartParameter().getLogLevel().compareTo(LogLevel.LIFECYCLE) >= 0) {
+					System.setOut(out);
+					System.setErr(err);
+				}
+
+				getProject().getLogger().lifecycle(":merged mappings (InstallerTools, srg + mojmap) in " + stopwatch.stop());
 			}
 		}
 	}
 
+	// Read mojmap and apply field descs to the tsrg2
+	private class FieldDescWrappingVisitor extends ForwardingMappingVisitor {
+		private final Map<FieldKey, String> fieldDescMap = new HashMap<>();
+		private String lastClass;
+
+		protected FieldDescWrappingVisitor(MappingVisitor next) throws IOException {
+			super(next);
+			MemoryMappingTree mojmap = new MemoryMappingTree();
+			MappingReader.read(getMojmapTsrg2(getProject(), getExtension()), mojmap);
+
+			for (MappingTree.ClassMapping classMapping : mojmap.getClasses()) {
+				for (MappingTree.FieldMapping fieldMapping : classMapping.getFields()) {
+					fieldDescMap.put(new FieldKey(classMapping.getSrcName(), fieldMapping.getSrcName()), fieldMapping.getSrcDesc());
+				}
+			}
+		}
+
+		@Override
+		public boolean visitClass(String srcName) throws IOException {
+			if (super.visitClass(srcName)) {
+				this.lastClass = srcName;
+				return true;
+			} else {
+				return false;
+			}
+		}
+
+		@Override
+		public boolean visitField(String srcName, String srcDesc) throws IOException {
+			if (srcDesc == null) {
+				srcDesc = fieldDescMap.get(new FieldKey(lastClass, srcName));
+			}
+
+			return super.visitField(srcName, srcDesc);
+		}
+
+		private record FieldKey(String owner, String name) {}
+	}
+
 	private void init(String version) {
 		File dir = getMinecraftProvider().dir("srg/" + version);
 		srg = new File(dir, "srg.tsrg").toPath();
+		mergedMojangRaw = new File(dir, "srg-mojmap-merged-raw.tsrg").toPath();
 		mergedMojang = new File(dir, "srg-mojmap-merged.tsrg").toPath();
 		mergedMojangTrimmed = new File(dir, "srg-mojmap-merged-trimmed.tsrg").toPath();
 	}
@@ -124,6 +195,12 @@ public class SrgProvider extends DependencyProvider {
 		return srg;
 	}
 
+	public Path getMergedMojangRaw() {
+		if (!isTsrgV2()) throw new IllegalStateException("May not access merged mojmap srg if not on modern Minecraft!");
+
+		return mergedMojangRaw;
+	}
+
 	public Path getMergedMojang() {
 		if (!isTsrgV2()) throw new IllegalStateException("May not access merged mojmap srg if not on modern Minecraft!");
 
@@ -141,30 +218,34 @@ public class SrgProvider extends DependencyProvider {
 	}
 
 	public static Path getMojmapTsrg(Project project, LoomGradleExtension extension) throws IOException {
-		Path path = extension.getMinecraftProvider().dir("forge").toPath().resolve("mojmap.tsrg");
+		if (mojmapTsrg != null) return mojmapTsrg;
+
+		mojmapTsrg = extension.getMinecraftProvider().dir("forge").toPath().resolve("mojmap.tsrg");
 
-		if (Files.notExists(path)) {
-			try (BufferedWriter writer = Files.newBufferedWriter(path, StandardCharsets.UTF_8, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING)) {
+		if (Files.notExists(mojmapTsrg) || LoomGradlePlugin.refreshDeps) {
+			try (BufferedWriter writer = Files.newBufferedWriter(mojmapTsrg, StandardCharsets.UTF_8, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING)) {
 				Tsrg2Utils.writeTsrg(visitor -> visitMojmap(visitor, project),
 						MappingsNamespace.NAMED.toString(), false, writer);
 			}
 		}
 
-		return path;
+		return mojmapTsrg;
 	}
 
 	public static Path getMojmapTsrg2(Project project, LoomGradleExtension extension) throws IOException {
-		Path path = extension.getMinecraftProvider().dir("forge").toPath().resolve("mojmap.tsrg2");
+		if (mojmapTsrg2 != null) return mojmapTsrg2;
+
+		mojmapTsrg2 = extension.getMinecraftProvider().dir("forge").toPath().resolve("mojmap.tsrg2");
 
-		if (Files.notExists(path)) {
-			try (BufferedWriter writer = Files.newBufferedWriter(path, StandardCharsets.UTF_8, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING)) {
+		if (Files.notExists(mojmapTsrg2) || LoomGradlePlugin.refreshDeps) {
+			try (BufferedWriter writer = Files.newBufferedWriter(mojmapTsrg2, StandardCharsets.UTF_8, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING)) {
 				MemoryMappingTree tree = new MemoryMappingTree();
 				visitMojmap(tree, project);
 				writer.write(Tsrg2Writer.serialize(tree));
 			}
 		}
 
-		return path;
+		return mojmapTsrg2;
 	}
 
 	private static void visitMojmap(MappingVisitor visitor, Project project) {
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/MappingsProviderImpl.java b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/MappingsProviderImpl.java
index f55087a7..1a3d5e35 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/MappingsProviderImpl.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/MappingsProviderImpl.java
@@ -156,7 +156,7 @@ public class MappingsProviderImpl extends DependencyProvider implements Mappings
 		if (getExtension().shouldGenerateSrgTiny()) {
 			if (Files.notExists(tinyMappingsWithSrg) || isRefreshDeps()) {
 				// Merge tiny mappings with srg
-				SrgMerger.mergeSrg(getProject().getLogger(), this::getMojmapSrgFileIfPossible, getRawSrgFile(), tinyMappings, tinyMappingsWithSrg, true);
+				SrgMerger.mergeSrg(getProject().getLogger(), null, getRawSrgFile(), tinyMappings, tinyMappingsWithSrg, true);
 			}
 
 			mappingTreeWithSrg = readMappings(tinyMappingsWithSrg);
@@ -241,7 +241,7 @@ public class MappingsProviderImpl extends DependencyProvider implements Mappings
 		return extension.getSrgProvider().getSrg();
 	}
 
-	protected Path getMojmapSrgFileIfPossible() {
+	public Path getMojmapSrgFileIfPossible() {
 		try {
 			LoomGradleExtension extension = getExtension();
 			return SrgProvider.getMojmapTsrg2(getProject(), extension);
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/MinecraftMappedProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/MinecraftMappedProvider.java
index 5d03b971..8ddb4492 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/MinecraftMappedProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/MinecraftMappedProvider.java
@@ -299,10 +299,10 @@ public class MinecraftMappedProvider extends DependencyProvider {
 
 	public Set<IMappingProvider> getMappings(@Nullable Set<String> fromClassNames, String fromM, String toM, Mutable<MemoryMappingTree> mappings) throws IOException {
 		Set<IMappingProvider> providers = new HashSet<>();
-		mappings.setValue(getExtension().isForge() ? getExtension().getMappingsProvider().getMappingsWithSrg() : getExtension().getMappingsProvider().getMappings());
+		mappings.setValue((true || fromM.equals("srg") || toM.equals("srg")) && getExtension().isForge() ? getExtension().getMappingsProvider().getMappingsWithSrg() : getExtension().getMappingsProvider().getMappings());
 		providers.add(TinyRemapperHelper.create(mappings.getValue(), fromM, toM, true));
 
-		if (getExtension().isForge()) {
+		if (getExtension().isForge() && (true || fromM.equals("srg") || toM.equals("srg"))) {
 			if (fromClassNames != null) {
 				providers.add(InnerClassRemapper.of(fromClassNames, getExtension().getMappingsProvider().getMappingsWithSrg(), fromM, toM));
 			}
diff --git a/src/main/java/net/fabricmc/loom/task/RemapJarTask.java b/src/main/java/net/fabricmc/loom/task/RemapJarTask.java
index 9fb95507..722df40d 100644
--- a/src/main/java/net/fabricmc/loom/task/RemapJarTask.java
+++ b/src/main/java/net/fabricmc/loom/task/RemapJarTask.java
@@ -165,7 +165,7 @@ public class RemapJarTask extends Jar {
 	}
 
 	private ReferenceRemapper createReferenceRemapper(LoomGradleExtension extension, String from, String to) throws IOException {
-		MappingTree mappings = extension.shouldGenerateSrgTiny() ? extension.getMappingsProvider().getMappingsWithSrg() : extension.getMappingsProvider().getMappings();
+		MappingTree mappings = (from.equals("srg") || to.equals("srg")) && extension.shouldGenerateSrgTiny() ? extension.getMappingsProvider().getMappingsWithSrg() : extension.getMappingsProvider().getMappings();
 
 		return new SimpleReferenceRemapper(new SimpleReferenceRemapper.Remapper() {
 			@Override
@@ -248,7 +248,7 @@ public class RemapJarTask extends Jar {
 		if (isMainRemapTask) {
 			jarRemapper.addToClasspath(getRemapClasspath());
 
-			jarRemapper.addMappings(TinyRemapperHelper.create(extension.shouldGenerateSrgTiny() ? mappingsProvider.getMappingsWithSrg() : mappingsProvider.getMappings(), fromM, toM, false));
+			jarRemapper.addMappings(TinyRemapperHelper.create((fromM.equals("srg") || toM.equals("srg")) && extension.shouldGenerateSrgTiny() ? mappingsProvider.getMappingsWithSrg() : mappingsProvider.getMappings(), fromM, toM, false));
 		}
 
 		for (File mixinMapFile : extension.getAllMixinMappings()) {
@@ -403,7 +403,7 @@ public class RemapJarTask extends Jar {
 	}
 
 	private IMappingProvider remapToSrg(LoomGradleExtension extension, IMappingProvider parent, String from, String to) throws IOException {
-		MappingTree mappings = extension.shouldGenerateSrgTiny() ? extension.getMappingsProvider().getMappingsWithSrg() : extension.getMappingsProvider().getMappings();
+		MappingTree mappings = (from.equals("srg") || to.equals("srg")) && extension.shouldGenerateSrgTiny() ? extension.getMappingsProvider().getMappingsWithSrg() : extension.getMappingsProvider().getMappings();
 
 		return sink -> {
 			parent.load(new IMappingProvider.MappingAcceptor() {
@@ -503,7 +503,7 @@ public class RemapJarTask extends Jar {
 			}
 
 			LoomGradleExtension extension = LoomGradleExtension.get(getProject());
-			MappingTree mappings = extension.shouldGenerateSrgTiny() ? extension.getMappingsProvider().getMappingsWithSrg() : extension.getMappingsProvider().getMappings();
+			MappingTree mappings = (fromM.get().equals("srg") || toM.get().equals("srg")) && extension.shouldGenerateSrgTiny() ? extension.getMappingsProvider().getMappingsWithSrg() : extension.getMappingsProvider().getMappings();
 
 			try (TinyMappingsReader reader = new TinyMappingsReader(mappings, fromM.get(), toM.get())) {
 				MappingSet mappingSet = reader.read();
diff --git a/src/main/java/net/fabricmc/loom/util/SourceRemapper.java b/src/main/java/net/fabricmc/loom/util/SourceRemapper.java
index 5f300aec..67e50407 100644
--- a/src/main/java/net/fabricmc/loom/util/SourceRemapper.java
+++ b/src/main/java/net/fabricmc/loom/util/SourceRemapper.java
@@ -184,7 +184,7 @@ public class SourceRemapper {
 
 		MappingSet mappings = extension.getOrCreateSrcMappingCache(id, () -> {
 			try {
-				MemoryMappingTree m = extension.shouldGenerateSrgTiny() ? mappingsProvider.getMappingsWithSrg() : mappingsProvider.getMappings();
+				MemoryMappingTree m = (from.equals("srg") || to.equals("srg")) && extension.shouldGenerateSrgTiny() ? mappingsProvider.getMappingsWithSrg() : mappingsProvider.getMappings();
 				project.getLogger().info(":loading " + from + " -> " + to + " source mappings");
 				return new TinyMappingsReader(m, from, to).read();
 			} catch (Exception e) {
diff --git a/src/main/java/net/fabricmc/loom/util/TinyRemapperHelper.java b/src/main/java/net/fabricmc/loom/util/TinyRemapperHelper.java
index 60f4ac3f..b9af8fb8 100644
--- a/src/main/java/net/fabricmc/loom/util/TinyRemapperHelper.java
+++ b/src/main/java/net/fabricmc/loom/util/TinyRemapperHelper.java
@@ -71,7 +71,7 @@ public final class TinyRemapperHelper {
 
 		TinyRemapper remapper = _getTinyRemapper(project, fixRecords).getKey();
 		remapper.replaceMappings(ImmutableSet.of(
-				TinyRemapperHelper.create(extension.isForge() ? extension.getMappingsProvider().getMappingsWithSrg() : extension.getMappingsProvider().getMappings(), fromM, toM, true),
+				TinyRemapperHelper.create((fromM.equals("srg") || toM.equals("srg")) && extension.isForge() ? extension.getMappingsProvider().getMappingsWithSrg() : extension.getMappingsProvider().getMappings(), fromM, toM, true),
 				out -> TinyRemapperHelper.JSR_TO_JETBRAINS.forEach(out::acceptClass)
 		));
 		return remapper;
diff --git a/src/main/java/net/fabricmc/loom/util/srg/SpecialSourceExecutor.java b/src/main/java/net/fabricmc/loom/util/srg/SpecialSourceExecutor.java
index 135cb170..6cbb0222 100644
--- a/src/main/java/net/fabricmc/loom/util/srg/SpecialSourceExecutor.java
+++ b/src/main/java/net/fabricmc/loom/util/srg/SpecialSourceExecutor.java
@@ -103,6 +103,7 @@ public class SpecialSourceExecutor {
 
 		Path output = extension.getFiles().getProjectBuildCache().toPath().resolve(officialJar.getFileName().toString().substring(0, officialJar.getFileName().toString().length() - 4) + "-srg-output.jar");
 		Files.deleteIfExists(output);
+		stopwatch = Stopwatch.createStarted();
 
 		if (specialSource) {
 			String[] args = new String[] {
@@ -134,6 +135,8 @@ public class SpecialSourceExecutor {
 					spec.setErrorOutput(NullOutputStream.NULL_OUTPUT_STREAM);
 				}
 			}).rethrowFailure().assertNormalExitValue();
+
+			project.getLogger().lifecycle(":remapped minecraft (SpecialSource, " + side + ", official -> srg) in " + stopwatch.stop());
 		} else {
 			List<String> args = new ArrayList<>(Arrays.asList(
 					"--jar-in",
@@ -172,6 +175,8 @@ public class SpecialSourceExecutor {
 					spec.setErrorOutput(NullOutputStream.NULL_OUTPUT_STREAM);
 				}
 			}).rethrowFailure().assertNormalExitValue();
+
+			project.getLogger().lifecycle(":remapped minecraft (Vignette, " + side + ", official -> mojang) in " + stopwatch.stop());
 		}
 
 		Files.deleteIfExists(stripped);
diff --git a/src/main/java/net/fabricmc/loom/util/srg/SrgMerger.java b/src/main/java/net/fabricmc/loom/util/srg/SrgMerger.java
index 024ad086..12004160 100644
--- a/src/main/java/net/fabricmc/loom/util/srg/SrgMerger.java
+++ b/src/main/java/net/fabricmc/loom/util/srg/SrgMerger.java
@@ -1,7 +1,7 @@
 /*
  * This file is part of fabric-loom, licensed under the MIT License (MIT).
  *
- * Copyright (c) 2020-2021 FabricMC
+ * Copyright (c) 2016, 2017, 2018 FabricMC
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -35,7 +35,6 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -46,8 +45,8 @@ import org.gradle.api.logging.Logger;
 import org.jetbrains.annotations.Nullable;
 
 import net.fabricmc.loom.util.function.CollectionUtil;
+import net.fabricmc.mappingio.FlatMappingVisitor;
 import net.fabricmc.mappingio.MappingReader;
-import net.fabricmc.mappingio.adapter.MappingDstNsReorder;
 import net.fabricmc.mappingio.adapter.RegularAsFlatMappingVisitor;
 import net.fabricmc.mappingio.format.Tiny2Writer;
 import net.fabricmc.mappingio.format.TsrgReader;
@@ -73,9 +72,18 @@ public final class SrgMerger {
 	 *                          or if an element mentioned in the SRG file does not have tiny mappings
 	 */
 	public static void mergeSrg(Logger logger, Supplier<Path> mojmap, Path srg, Path tiny, Path out, boolean lenient) throws IOException, MappingException {
+		MemoryMappingTree tree = mergeSrg(logger, mojmap, srg, tiny, lenient);
+
+		try (Tiny2Writer writer = new Tiny2Writer(Files.newBufferedWriter(out), false)) {
+			tree.accept(writer);
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+	}
+
+	public static MemoryMappingTree mergeSrg(Logger logger, Supplier<Path> mojmap, Path srg, Path tiny, boolean lenient) throws IOException, MappingException {
 		Map<String, List<MappingTreeView.MemberMappingView>> addRegardlessSrgs = new HashMap<>();
 		MemoryMappingTree arr = readSrg(srg, mojmap, addRegardlessSrgs);
-		addRegardlessSrgs.clear();
 		MemoryMappingTree foss = new MemoryMappingTree();
 
 		try (BufferedReader reader = Files.newBufferedReader(tiny)) {
@@ -87,19 +95,14 @@ public final class SrgMerger {
 		}
 
 		MemoryMappingTree output = new MemoryMappingTree();
-		output.visitNamespaces(foss.getSrcNamespace(), Stream.concat(foss.getDstNamespaces().stream(), Stream.of("srg")).collect(Collectors.toList()));
+		output.visitNamespaces(foss.getSrcNamespace(), Stream.concat(Stream.of("srg"), foss.getDstNamespaces().stream()).collect(Collectors.toList()));
 		RegularAsFlatMappingVisitor flatMappingVisitor = new RegularAsFlatMappingVisitor(output);
 
 		for (MappingTree.ClassMapping klass : arr.getClasses()) {
-			classToTiny(logger,  addRegardlessSrgs, klass, foss, flatMappingVisitor, output, lenient);
+			classToTiny(logger, addRegardlessSrgs, foss, klass, output, flatMappingVisitor, lenient);
 		}
 
-		try (Tiny2Writer writer = new Tiny2Writer(Files.newBufferedWriter(out), false)) {
-			MappingDstNsReorder reorder = new MappingDstNsReorder(writer, Stream.concat(Stream.of("srg"), foss.getDstNamespaces().stream()).collect(Collectors.toList()));
-			output.accept(reorder);
-		} catch (IOException e) {
-			e.printStackTrace();
-		}
+		return output;
 	}
 
 	private static MemoryMappingTree readSrg(Path srg, Supplier<Path> mojmap, Map<String, List<MappingTreeView.MemberMappingView>> addRegardlessSrgs)
@@ -107,20 +110,17 @@ public final class SrgMerger {
 		try (BufferedReader reader = Files.newBufferedReader(srg)) {
 			String content = IOUtils.toString(reader);
 
-			if (content.startsWith("tsrg2")) {
-				return readTsrg2(content, mojmap, addRegardlessSrgs);
-			} else {
-				MemoryMappingTree tsrg = new MemoryMappingTree();
-				TsrgReader.read(new StringReader(content), tsrg);
-				return tsrg;
+			if (content.startsWith("tsrg2") && mojmap != null) {
+				addRegardlessSrgs(mojmap, addRegardlessSrgs);
 			}
+
+			MemoryMappingTree tsrg = new MemoryMappingTree();
+			TsrgReader.read(new StringReader(content), tsrg);
+			return tsrg;
 		}
 	}
 
-	private static MemoryMappingTree readTsrg2(String content, Supplier<Path> mojmap, Map<String, List<MappingTreeView.MemberMappingView>> addRegardlessSrgs)
-			throws IOException {
-		MemoryMappingTree tsrg2 = new MemoryMappingTree();
-		TsrgReader.read(new StringReader(content), tsrg2);
+	private static void addRegardlessSrgs(Supplier<Path> mojmap, Map<String, List<MappingTreeView.MemberMappingView>> addRegardlessSrgs) throws IOException {
 		MemoryMappingTree mojmapTree = readTsrg2ToTinyTree(mojmap.get());
 
 		for (MappingTree.ClassMapping classDef : mojmapTree.getClasses()) {
@@ -138,8 +138,6 @@ public final class SrgMerger {
 				}
 			}
 		}
-
-		return tsrg2;
 	}
 
 	private static MemoryMappingTree readTsrg2ToTinyTree(Path path) throws IOException {
@@ -152,14 +150,13 @@ public final class SrgMerger {
 		return tree;
 	}
 
-	private static void classToTiny(Logger logger, Map<String, List<MappingTreeView.MemberMappingView>> addRegardlessSrgs, MappingTree.ClassMapping klass, MemoryMappingTree foss, RegularAsFlatMappingVisitor flatOutput, MemoryMappingTree output, boolean lenient)
+	private static void classToTiny(Logger logger, Map<String, List<MappingTreeView.MemberMappingView>> addRegardlessSrgs, MappingTree foss, MappingTree.ClassMapping klass, MappingTree output, FlatMappingVisitor flatOutput, boolean lenient)
 			throws IOException {
 		String obf = klass.getSrcName();
 		String srg = klass.getDstName(0);
-		MappingTree.ClassMapping fossClass = foss.getClass(obf);
-		int srgId = output.getNamespaceId("srg");
+		MappingTree.ClassMapping classDef = foss.getClass(obf);
 
-		if (fossClass == null) {
+		if (classDef == null) {
 			if (lenient) {
 				return;
 			} else {
@@ -167,63 +164,92 @@ public final class SrgMerger {
 			}
 		}
 
-		flatOutput.visitClass(obf, output.getDstNamespaces().stream().map(ns ->
-				ns.equals("srg") ? srg : fossClass.getName(ns)).toArray(String[]::new));
+		List<String> classNames = CollectionUtil.map(
+				output.getDstNamespaces(),
+				namespace -> "srg".equals(namespace) ? srg : classDef.getName(namespace)
+		);
+
+		flatOutput.visitClass(obf, classNames.toArray(new String[0]));
 
 		for (MappingTree.MethodMapping method : klass.getMethods()) {
-			MappingTree.MethodMapping fossMethod = CollectionUtil.find(
-					fossClass.getMethods(),
-					m -> m.getSrcName().equals(method.getSrcName()) && m.getSrcDesc().equals(method.getSrcDesc())
+			MappingTree.MethodMapping def = CollectionUtil.find(
+					classDef.getMethods(),
+					m -> m.getName("official").equals(method.getSrcName()) && m.getDesc("official").equals(method.getSrcDesc())
 			).orElse(null);
 
-			if (fossMethod == null) {
-				if (tryMatchRegardlessSrgs(addRegardlessSrgs, obf, method)) {
-					flatOutput.visitMethod(obf, method.getSrcName(), method.getSrcDesc(), output.getDstNamespaces().stream().map(ns ->
-							ns.equals("srg") ? method.getDstName(0) : method.getSrcName()).toArray(String[]::new));
-					continue;
-				}
+			if (def == null) {
+				if (tryMatchRegardlessSrgsMethod(addRegardlessSrgs, obf, output, flatOutput, method)) continue;
 
 				if (!lenient) {
 					throw new MappingException("Missing method: " + method.getSrcName() + " (srg: " + method.getDstName(0) + ")");
 				}
 
-				logger.debug("Missing method: " + method.getSrcName() + method.getSrcDesc() + " (srg: " + method.getDstName(0) + ") " + fossClass.getMethods().size() + " methods in the original class");
-
 				continue;
 			}
 
-			flatOutput.visitMethod(obf, fossMethod.getSrcName(), fossMethod.getSrcDesc(), output.getDstNamespaces().stream().map(ns ->
-					ns.equals("srg") ? method.getDstName(0) : fossMethod.getName(ns)).toArray(String[]::new));
+			List<String> methodNames = CollectionUtil.map(
+					output.getDstNamespaces(),
+					namespace -> "srg".equals(namespace) ? method.getDstName(0) : def.getName(namespace)
+			);
 
-			for (MappingTree.MethodArgMapping arg : fossMethod.getArgs()) {
-				flatOutput.visitMethodArg(obf, fossMethod.getSrcName(), fossMethod.getSrcDesc(), arg.getArgPosition(),
-						arg.getLvIndex(), arg.getSrcName(), output.getDstNamespaces().stream().map(ns ->
-								ns.equals("srg") ? arg.getName("named") : arg.getName(ns)).toArray(String[]::new));
-			}
+			flatOutput.visitMethod(obf, def.getName("official"), def.getDesc("official"), methodNames.toArray(new String[0]));
 		}
 
 		for (MappingTree.FieldMapping field : klass.getFields()) {
-			MappingTree.FieldMapping fossField = CollectionUtil.find(
-					fossClass.getFields(),
-					f -> f.getSrcName().equals(field.getSrcName())
+			MappingTree.FieldMapping def = CollectionUtil.find(
+					classDef.getFields(),
+					f -> f.getName("official").equals(field.getSrcName())
 			).orElse(nullOrThrow(lenient, () -> new MappingException("Missing field: " + field.getSrcName() + " (srg: " + field.getDstName(0) + ")")));
 
-			if (fossField == null) {
-				logger.debug("Missing field: " + field.getSrcName() + " (srg: " + field.getDstName(0) + ") " + fossClass.getFields().size() + " fields in the original class");
+			if (def == null) {
+				if (tryMatchRegardlessSrgsField(addRegardlessSrgs, obf, output, flatOutput, field)) continue;
+
 				continue;
 			}
 
-			flatOutput.visitField(obf, fossField.getSrcName(), fossField.getSrcDesc(), output.getDstNamespaces().stream().map(ns ->
-					ns.equals("srg") ? field.getDstName(0) : fossField.getName(ns)).toArray(String[]::new));
+			List<String> fieldNames = CollectionUtil.map(
+					output.getDstNamespaces(),
+					namespace -> "srg".equals(namespace) ? field.getDstName(0) : def.getName(namespace)
+			);
+
+			flatOutput.visitField(obf, def.getName("official"), def.getDesc("official"), fieldNames.toArray(new String[0]));
 		}
 	}
 
-	private static boolean tryMatchRegardlessSrgs(Map<String, List<MappingTreeView.MemberMappingView>> addRegardlessSrgs, String obf, MappingTree.MethodMapping method) {
+	private static boolean tryMatchRegardlessSrgsMethod(Map<String, List<MappingTreeView.MemberMappingView>> addRegardlessSrgs, String obf,
+			MappingTree output, FlatMappingVisitor flatOutput, MappingTree.MethodMapping method) throws IOException {
 		List<MappingTreeView.MemberMappingView> mutableDescriptoredList = addRegardlessSrgs.get(obf);
 
-		if (!Objects.equals(method.getDstName(0), method.getSrcName())) {
+		if (!method.getDstName(0).equals(method.getSrcName())) {
 			for (MappingTreeView.MemberMappingView descriptored : MoreObjects.firstNonNull(mutableDescriptoredList, Collections.<MappingTreeView.MemberMappingView>emptyList())) {
-				if (descriptored instanceof MappingTreeView.MethodMappingView && descriptored.getSrcName().equals(method.getSrcName()) && descriptored.getSrcDesc().equals(method.getSrcDesc())) {
+				if (descriptored instanceof MappingTree.MethodMapping && descriptored.getSrcName().equals(method.getSrcName()) && descriptored.getSrcDesc().equals(method.getSrcDesc())) {
+					List<String> methodNames = CollectionUtil.map(
+							output.getDstNamespaces(),
+							namespace -> "srg".equals(namespace) ? method.getDstName(0) : method.getSrcName()
+					);
+
+					flatOutput.visitMethod(obf, method.getSrcName(), method.getSrcDesc(), methodNames.toArray(new String[0]));
+					return true;
+				}
+			}
+		}
+
+		return false;
+	}
+
+	private static boolean tryMatchRegardlessSrgsField(Map<String, List<MappingTreeView.MemberMappingView>> addRegardlessSrgs, String obf,
+			MappingTree output, FlatMappingVisitor flatOutput, MappingTree.FieldMapping field) throws IOException {
+		List<MappingTreeView.MemberMappingView> mutableDescriptoredList = addRegardlessSrgs.get(obf);
+
+		if (!field.getDstName(0).equals(field.getSrcName())) {
+			for (MappingTreeView.MemberMappingView descriptored : MoreObjects.firstNonNull(mutableDescriptoredList, Collections.<MappingTreeView.MemberMappingView>emptyList())) {
+				if (descriptored instanceof MappingTree.FieldMapping && descriptored.getSrcName().equals(field.getSrcName())) {
+					List<String> fieldNames = CollectionUtil.map(
+							output.getDstNamespaces(),
+							namespace -> "srg".equals(namespace) ? field.getDstName(0) : field.getSrcName()
+					);
+
+					flatOutput.visitField(obf, field.getSrcName(), field.getSrcDesc(), fieldNames.toArray(new String[0]));
 					return true;
 				}
 			}
@@ -240,4 +266,4 @@ public final class SrgMerger {
 			throw exception.get();
 		}
 	}
-}
+}
\ No newline at end of file
diff --git a/src/main/java/net/fabricmc/loom/util/srg/Tsrg2Writer.java b/src/main/java/net/fabricmc/loom/util/srg/Tsrg2Writer.java
index 96c28e30..7463e447 100644
--- a/src/main/java/net/fabricmc/loom/util/srg/Tsrg2Writer.java
+++ b/src/main/java/net/fabricmc/loom/util/srg/Tsrg2Writer.java
@@ -48,39 +48,39 @@ public class Tsrg2Writer {
 	}
 
 	private static void writeClass(List<String> namespaces, MappingTree.ClassMapping def, StringBuilder builder) {
-		writeMapped(false, namespaces, def, builder);
+		writeMapped(null, namespaces, def, builder);
 
 		for (MappingTree.MethodMapping method : def.getMethods()) {
 			writeMethod(namespaces, method, builder);
 		}
 
 		for (MappingTree.FieldMapping field : def.getFields()) {
-			writeMapped(true, namespaces, field, builder);
+			writeMapped('\t', namespaces, field, builder);
 		}
 	}
 
 	private static void writeMethod(List<String> namespaces, MappingTree.MethodMapping def, StringBuilder builder) {
-		writeMapped(true, namespaces, def, builder);
+		writeMapped('\t', namespaces, def, builder);
 
 		for (MappingTree.MethodArgMapping arg : def.getArgs()) {
 			builder.append("\t\t").append(arg.getLvIndex());
-			writeMapped(true, namespaces, arg, builder);
+			writeMapped(' ', namespaces, arg, builder);
 		}
 	}
 
 	private static void writeField(List<String> namespaces, MappingTree.FieldMapping def, StringBuilder builder) {
-		writeMapped(true, namespaces, def, builder);
+		writeMapped('\t', namespaces, def, builder);
 	}
 
-	private static void writeMapped(boolean needFirst, List<String> namespaces, MappingTreeView.ElementMappingView mapped, StringBuilder builder) {
+	private static void writeMapped(Character first, List<String> namespaces, MappingTreeView.ElementMappingView mapped, StringBuilder builder) {
 		String[] names = namespaces.stream().map(mapped::getName).toArray(String[]::new);
 
 		for (int i = 0; i < names.length; ++i) {
 			String name = names[i];
 
 			if (i == 0) {
-				if (needFirst) {
-					builder.append('\t');
+				if (first != null) {
+					builder.append(first);
 				}
 			} else {
 				builder.append(' ');