Remapper extensions (#984)

* Remapper extension API

* Fix build

* More work

* Fixes, thanks Gradle.

* Build fix

* Cleanup

src/main/java/net/fabricmc/loom/LoomGradleExtension.java

@@ -45,6 +45,7 @@
 import net.fabricmc.loom.configuration.providers.minecraft.mapped.NamedMinecraftProvider;
 import net.fabricmc.loom.extension.LoomFiles;
 import net.fabricmc.loom.extension.MixinExtension;
+import net.fabricmc.loom.extension.RemapperExtensionHolder;
 import net.fabricmc.loom.util.download.DownloadBuilder;
 
 @ApiStatus.Internal
@@ -115,4 +116,6 @@ default List<Path> getMinecraftJars(MappingsNamespace mappingsNamespace) {
 	boolean multiProjectOptimisation();
 
 	ListProperty<LibraryProcessorManager.LibraryProcessorFactory> getLibraryProcessors();
+
+	ListProperty<RemapperExtensionHolder> getRemapperExtensions();
 }

src/main/java/net/fabricmc/loom/api/LoomGradleExtensionAPI.java

@@ -44,6 +44,8 @@
 import net.fabricmc.loom.api.mappings.intermediate.IntermediateMappingsProvider;
 import net.fabricmc.loom.api.mappings.layered.spec.LayeredMappingSpecBuilder;
 import net.fabricmc.loom.api.processor.MinecraftJarProcessor;
+import net.fabricmc.loom.api.remapping.RemapperExtension;
+import net.fabricmc.loom.api.remapping.RemapperParameters;
 import net.fabricmc.loom.configuration.ide.RunConfigSettings;
 import net.fabricmc.loom.configuration.processors.JarProcessor;
 import net.fabricmc.loom.configuration.providers.mappings.NoOpIntermediateMappingsProvider;
@@ -221,4 +223,6 @@ default void splitMinecraftJar() {
 	Property<Boolean> getRuntimeOnlyLog4j();
 
 	Property<Boolean> getSplitModDependencies();
+
+	<T extends RemapperParameters> void addRemapperExtension(Class<RemapperExtension<T>> remapperExtensionClass, Class<T> parametersClass, Action<T> parameterAction);
 }

src/main/java/net/fabricmc/loom/api/remapping/RemapperContext.java

@@ -0,0 +1,47 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2023 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.api.remapping;
+
+import org.objectweb.asm.commons.Remapper;
+
+/**
+ * Context for a {@link RemapperExtension}.
+ */
+public interface RemapperContext {
+	/**
+	 * @return The {@link Remapper} instance
+	 */
+	Remapper remapper();
+
+	/**
+	 * @return the source namespace
+	 */
+	String sourceNamespace();
+
+	/**
+	 * @return the target namespace
+	 */
+	String targetNamespace();
+}

src/main/java/net/fabricmc/loom/api/remapping/RemapperExtension.java

@@ -0,0 +1,53 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2023 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.api.remapping;
+
+import javax.inject.Inject;
+
+import org.gradle.api.Action;
+import org.objectweb.asm.ClassVisitor;
+
+/**
+ * A remapper extension can be used to add extra processing to the remapping process.
+ *
+ * <p>Implementations of RemapperExtension's must have the following:
+ * A single constructor annotated with {@link Inject}, and taking a single argument of the parameters.
+ * Or a single constructor annotated with {@link Inject} taking no arguments, when the extension does not have any parameters.
+ *
+ * <p>Use {@link net.fabricmc.loom.api.LoomGradleExtensionAPI#addRemapperExtension(Class, Class, Action)} to register a remapper extension.
+ *
+ * @param <T> Parameter type for the extension. Should be {@link RemapperParameters.None} if the action does not have parameters.
+ */
+public interface RemapperExtension<T extends RemapperParameters> {
+	/**
+	 * Return a {@link ClassVisitor} that will be used when remapping the given class.
+	 *
+	 * @param className The name of the class being remapped
+	 * @param remapperContext The remapper context
+	 * @param classVisitor The parent class visitor
+	 * @return A {@link ClassVisitor} that will be used when remapping the given class, or the given {@code classVisitor} if no extra processing is required for this class.
+	 */
+	ClassVisitor insertVisitor(String className, RemapperContext remapperContext, ClassVisitor classVisitor);
+}

src/main/java/net/fabricmc/loom/api/remapping/RemapperParameters.java

@@ -0,0 +1,42 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2023 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.api.remapping;
+
+import org.jetbrains.annotations.ApiStatus;
+
+/**
+ * Marker interface for parameter objects to {@link RemapperExtension}s.
+ *
+ * <p>Design based off of Gradle's {@link org.gradle.workers.WorkParameters}.
+ */
+public interface RemapperParameters {
+	final class None implements RemapperParameters {
+		@ApiStatus.Internal
+		public static None INSTANCE = new None();
+
+		private None() {
+		}
+	}
+}

src/main/java/net/fabricmc/loom/api/remapping/TinyRemapperExtension.java

@@ -0,0 +1,68 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2023 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.api.remapping;
+
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Nullable;
+
+import net.fabricmc.tinyremapper.TinyRemapper;
+
+/**
+ * A remapper extension, that has direct access to the TinyRemapper APIs.
+ *
+ * <p>This API is not stable and may change without notice.
+ */
+@ApiStatus.Experimental
+public interface TinyRemapperExtension {
+	/**
+	 * See: {@link TinyRemapper.Builder#extraAnalyzeVisitor(TinyRemapper.AnalyzeVisitorProvider)}.
+	 *
+	 * @return A {@link TinyRemapper.AnalyzeVisitorProvider} or {@code null}.
+	 */
+	@Nullable
+	default TinyRemapper.AnalyzeVisitorProvider getAnalyzeVisitorProvider() {
+		return null;
+	}
+
+	/**
+	 * See: {@link TinyRemapper.Builder#extraPreApplyVisitor(TinyRemapper.ApplyVisitorProvider)}.
+	 *
+	 * @return A {@link TinyRemapper.ApplyVisitorProvider} or {@code null}.
+	 */
+	@Nullable
+	default TinyRemapper.ApplyVisitorProvider getPreApplyVisitor() {
+		return null;
+	}
+
+	/**
+	 * See: {@link TinyRemapper.Builder#extraPostApplyVisitor(TinyRemapper.ApplyVisitorProvider)}.
+	 *
+	 * @return A {@link TinyRemapper.ApplyVisitorProvider} or {@code null}.
+	 */
+	@Nullable
+	default TinyRemapper.ApplyVisitorProvider getPostApplyVisitor() {
+		return null;
+	}
+}

src/main/java/net/fabricmc/loom/configuration/mods/ModProcessor.java

@@ -51,6 +51,7 @@
 import net.fabricmc.loom.api.mappings.layered.MappingsNamespace;
 import net.fabricmc.loom.configuration.mods.dependency.ModDependency;
 import net.fabricmc.loom.configuration.providers.mappings.MappingConfiguration;
+import net.fabricmc.loom.extension.RemapperExtensionHolder;
 import net.fabricmc.loom.util.Constants;
 import net.fabricmc.loom.util.Pair;
 import net.fabricmc.loom.util.TinyRemapperHelper;
@@ -157,6 +158,10 @@ private void remapJars(List<ModDependency> remapList) throws IOException {
 			builder.extension(new MixinExtension(remapMixins::contains));
 		}
 
+		for (RemapperExtensionHolder holder : extension.getRemapperExtensions().get()) {
+			holder.apply(builder, fromM, toM, project.getObjects());
+		}
+
 		final TinyRemapper remapper = builder.build();
 
 		for (Path minecraftJar : extension.getMinecraftJars(MappingsNamespace.INTERMEDIARY)) {

src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionApiImpl.java

@@ -34,6 +34,7 @@
 import org.gradle.api.artifacts.Dependency;
 import org.gradle.api.file.ConfigurableFileCollection;
 import org.gradle.api.file.RegularFileProperty;
+import org.gradle.api.model.ObjectFactory;
 import org.gradle.api.provider.ListProperty;
 import org.gradle.api.provider.Property;
 import org.gradle.api.provider.SetProperty;
@@ -50,6 +51,8 @@
 import net.fabricmc.loom.api.mappings.intermediate.IntermediateMappingsProvider;
 import net.fabricmc.loom.api.mappings.layered.spec.LayeredMappingSpecBuilder;
 import net.fabricmc.loom.api.processor.MinecraftJarProcessor;
+import net.fabricmc.loom.api.remapping.RemapperExtension;
+import net.fabricmc.loom.api.remapping.RemapperParameters;
 import net.fabricmc.loom.configuration.RemapConfigurations;
 import net.fabricmc.loom.configuration.ide.RunConfigSettings;
 import net.fabricmc.loom.configuration.processors.JarProcessor;
@@ -91,6 +94,7 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 	private final NamedDomainObjectContainer<ModSettings> mods;
 	private final NamedDomainObjectList<RemapConfigurationSettings> remapConfigurations;
 	private final ListProperty<MinecraftJarProcessor<?>> minecraftJarProcessors;
+	protected final ListProperty<RemapperExtensionHolder> remapperExtensions;
 
 	// A common mistake with layered mappings is to call the wrong `officialMojangMappings` method, use this to keep track of when we are building a layered mapping spec.
 	protected final ThreadLocal<Boolean> layeredSpecBuilderScope = ThreadLocal.withInitial(() -> false);
@@ -150,6 +154,9 @@ protected LoomGradleExtensionApiImpl(Project project, LoomFiles directories) {
 		this.splitEnvironmentalSourceSet = project.getObjects().property(Boolean.class).convention(false);
 		this.splitEnvironmentalSourceSet.finalizeValueOnRead();
 
+		remapperExtensions = project.getObjects().listProperty(RemapperExtensionHolder.class);
+		remapperExtensions.finalizeValueOnRead();
+
 		// Enable dep iface injection by default
 		interfaceInjection(interfaceInjection -> {
 			interfaceInjection.getEnableDependencyInterfaceInjection().convention(true).finalizeValueOnRead();
@@ -382,6 +389,23 @@ public void createRemapConfigurations(SourceSet sourceSet) {
 		RemapConfigurations.setupForSourceSet(getProject(), sourceSet);
 	}
 
+	@Override
+	public <T extends RemapperParameters> void addRemapperExtension(Class<RemapperExtension<T>> remapperExtensionClass, Class<T> parametersClass, Action<T> parameterAction) {
+		final ObjectFactory objectFactory = getProject().getObjects();
+		final RemapperExtensionHolder holder;
+
+		if (parametersClass != RemapperParameters.None.class) {
+			T parameters = objectFactory.newInstance(parametersClass);
+			parameterAction.execute(parameters);
+			holder = objectFactory.newInstance(RemapperExtensionHolder.class, parameters);
+		} else {
+			holder = objectFactory.newInstance(RemapperExtensionHolder.class, RemapperParameters.None.INSTANCE);
+		}
+
+		holder.getRemapperExtensionClassName().set(remapperExtensionClass.getName());
+		remapperExtensions.add(holder);
+	}
+
 	// This is here to ensure that LoomGradleExtensionApiImpl compiles without any unimplemented methods
 	private final class EnsureCompile extends LoomGradleExtensionApiImpl {
 		private EnsureCompile() {

src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionImpl.java

@@ -247,6 +247,11 @@ public ListProperty<LibraryProcessorManager.LibraryProcessorFactory> getLibraryP
 		return libraryProcessorFactories;
 	}
 
+	@Override
+	public ListProperty<RemapperExtensionHolder> getRemapperExtensions() {
+		return remapperExtensions;
+	}
+
 	@Override
 	protected <T extends IntermediateMappingsProvider> void configureIntermediateMappingsProviderInternal(T provider) {
 		provider.getMinecraftVersion().set(getProject().provider(() -> getMinecraftProvider().minecraftVersion()));