Add preliminary plugin support

build.gradle

@@ -5,24 +5,48 @@ plugins {
 	id 'checkstyle'
 }
 
-checkstyle {
-	configFile = file('checkstyle.xml')
-}
+allprojects {
+	apply plugin: 'java-library'
+	apply plugin: 'maven-publish'
+	apply plugin: 'org.cadixdev.licenser'
+	apply plugin: 'checkstyle'
 
-sourceCompatibility = JavaVersion.VERSION_1_8
-targetCompatibility = JavaVersion.VERSION_1_8
+	sourceCompatibility = JavaVersion.VERSION_1_8
+	targetCompatibility = JavaVersion.VERSION_1_8
 
-def ENV = System.getenv()
-version += (ENV.GITHUB_ACTIONS ? '' : '+local')
+	repositories {
+		mavenCentral()
+		maven {
+			name = 'Fabric'
+			url = 'https://maven.fabricmc.net/'
+		}
+	}
 
-repositories {
-	mavenCentral()
-	maven {
-		name = 'Fabric'
-		url = 'https://maven.fabricmc.net/'
+	checkstyle {
+		configFile = rootProject.file('checkstyle.xml')
+	}
+
+	license {
+		header rootProject.file('HEADER')
+		include '**/*.java'
+	}
+
+	java {
+		withSourcesJar()
+	}
+
+	tasks.withType(JavaCompile).configureEach {
+		it.options.encoding = 'UTF-8'
+
+		if (JavaVersion.current().isJava9Compatible()) {
+			it.options.release = 8
+		}
 	}
 }
 
+def ENV = System.getenv()
+version += (ENV.GITHUB_ACTIONS ? '' : '+local')
+
 configurations {
 	ship
 	implementation.extendsFrom ship
@@ -42,11 +66,6 @@ dependencies {
 	testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:${junit_jupiter_version}"
 }
 
-license {
-	header project.file('HEADER')
-	include '**/*.java'
-}
-
 jar {
 	manifest {
 		attributes 'Implementation-Title': 'Stitch',
@@ -70,18 +89,6 @@ task allJar(type: Jar) {
 	with jar
 }
 
-java {
-	withSourcesJar()
-}
-
-tasks.withType(JavaCompile).configureEach {
-	it.options.encoding = 'UTF-8'
-
-	if (JavaVersion.current().isJava9Compatible()) {
-		it.options.release = 8
-	}
-}
-
 publishing {
 	publications {
 		mavenJava(MavenPublication) {

minecraft-plugin/build.gradle

@@ -0,0 +1,31 @@
+archivesBaseName = 'stitch-minecraft-plugin'
+version = rootProject.version
+group = rootProject.group
+
+dependencies {
+	implementation project(':')
+}
+
+def ENV = System.getenv()
+
+publishing {
+	publications {
+		mavenJava(MavenPublication) {
+			from components.java
+			artifact(jar)
+		}
+	}
+
+	repositories {
+		if (ENV.MAVEN_URL) {
+			repositories.maven {
+				name 'fabric'
+				url ENV.MAVEN_URL
+				credentials {
+					username ENV.MAVEN_USERNAME
+					password ENV.MAVEN_PASSWORD
+				}
+			}
+		}
+	}
+}

minecraft-plugin/src/main/java/net/fabricmc/stitch/plugins/MinecraftPlugin.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.fabricmc.stitch.plugins;
+
+import net.fabricmc.stitch.plugin.StitchPlugin;
+import net.fabricmc.stitch.representation.ClassStorage;
+import net.fabricmc.stitch.representation.JarClassEntry;
+import net.fabricmc.stitch.representation.JarFieldEntry;
+import net.fabricmc.stitch.representation.JarMethodEntry;
+
+public class MinecraftPlugin implements StitchPlugin {
+	@Override
+	public int needsIntermediaryName(ClassStorage storage, JarClassEntry cls, JarFieldEntry fld) {
+		String name = fld.getName();
+
+		return name.length() <= 2 || (name.length() == 3 && name.charAt(2) == '_') ? 2 : -2;
+	}
+
+	@Override
+	public int needsIntermediaryName(ClassStorage storage, JarClassEntry cls, JarMethodEntry mth) {
+		String name = mth.getName();
+
+		return (name.length() <= 2 || (name.length() == 3 && name.charAt(2) == '_'))
+				&& name.charAt(0) != '<'
+				&& mth.isSource(storage, cls) ? 2 : -2;
+	}
+}

minecraft-plugin/src/main/resources/META-INF/services/net.fabricmc.stitch.plugin.StitchPlugin

@@ -0,0 +1 @@
+net.fabricmc.stitch.plugin.StitchPlugin

settings.gradle

@@ -9,3 +9,5 @@ pluginManagement {
 }
 
 rootProject.name = 'stitch'
+
+include ':minecraft-plugin'

src/main/java/net/fabricmc/stitch/Main.java

@@ -28,6 +28,7 @@
 import net.fabricmc.stitch.commands.CommandRewriteIntermediary;
 import net.fabricmc.stitch.commands.CommandUpdateIntermediary;
 import net.fabricmc.stitch.commands.CommandValidateRecords;
+import net.fabricmc.stitch.plugin.PluginLoader;
 
 public class Main {
 	private static final Map<String, Command> COMMAND_MAP = new TreeMap<>();
@@ -72,6 +73,7 @@ public static void main(String[] args) {
 				System.arraycopy(args, 1, argsCommand, 0, argsCommand.length);
 			}
 
+			PluginLoader.loadPlugins();
 			COMMAND_MAP.get(args[0].toLowerCase(Locale.ROOT)).run(argsCommand);
 		} catch (Exception e) {
 			e.printStackTrace();

src/main/java/net/fabricmc/stitch/commands/GenState.java

@@ -34,8 +34,10 @@
 import java.util.Scanner;
 import java.util.Set;
 import java.util.TreeSet;
+import java.util.function.Function;
 import java.util.regex.Pattern;
 import java.util.regex.PatternSyntaxException;
+import java.util.stream.Collectors;
 
 import org.checkerframework.checker.nullness.qual.Nullable;
 import org.objectweb.asm.Opcodes;
@@ -51,6 +53,8 @@
 import net.fabricmc.mappingio.tree.MappingTree.ClassMapping;
 import net.fabricmc.mappingio.tree.MappingTree.FieldMapping;
 import net.fabricmc.mappingio.tree.MappingTree.MethodMapping;
+import net.fabricmc.stitch.plugin.PluginRegistry;
+import net.fabricmc.stitch.plugin.StitchPlugin;
 import net.fabricmc.stitch.representation.AbstractJarEntry;
 import net.fabricmc.stitch.representation.ClassStorage;
 import net.fabricmc.stitch.representation.JarClassEntry;
@@ -77,11 +81,11 @@ class GenState {
 	private boolean writeAll = false;
 	private Scanner scanner = new Scanner(System.in);
 
-	private String targetPackage = "net/minecraft/";
+	private String targetPackage = "";
 	private final List<Pattern> obfuscatedPatterns = new ArrayList<Pattern>();
 
 	GenState() throws IOException {
-		this.obfuscatedPatterns.add(Pattern.compile("^[^/]*$")); // Default obfuscation. Minecraft classes without a package are obfuscated.
+		this.obfuscatedPatterns.add(Pattern.compile("^.*$")); // Default obfuscation. Minecraft classes without a package are obfuscated.
 		mappingTree.visitNamespaces(official, Arrays.asList(intermediary, intermediary));
 	}
 
@@ -180,30 +184,42 @@ public void generate(File file, JarRootEntry jarEntry, JarRootEntry jarOld) thro
 		writer.close();
 	}
 
-	public static boolean isMappedClass(ClassStorage storage, JarClassEntry c) {
-		return !c.isAnonymous();
-	}
+	private boolean needsIntermediaryName(Function<StitchPlugin, Integer> priorityGetter) {
+		List<Integer> results = PluginRegistry.getPlugins().stream()
+				.map(plugin -> priorityGetter.apply(plugin))
+				.sorted((a, b) -> Math.abs(b) - Math.abs(a))
+				.collect(Collectors.toList());
+
+		int first = results.get(0);
+
+		if (results.size() > 1) {
+			int second = results.get(1);
+
+			if (first != 0
+					&& first != second
+					&& Math.abs(first) == Math.abs(second)) {
+				throw new IllegalStateException("Got conflicting scores of the same priority!");
+			}
+		}
 
-	public static boolean isMappedField(ClassStorage storage, JarClassEntry c, JarFieldEntry f) {
-		return isUnmappedFieldName(f.getName());
+		return first > 0;
 	}
 
-	public static boolean isUnmappedFieldName(String name) {
-		return name.length() <= 2 || (name.length() == 3 && name.charAt(2) == '_');
+	private boolean needsIntermediaryName(ClassStorage storage, JarClassEntry cls) {
+		return needsIntermediaryName((plugin) -> plugin.needsIntermediaryName(storage, cls));
 	}
 
-	public static boolean isMappedMethod(ClassStorage storage, JarClassEntry c, JarMethodEntry m) {
-		return isUnmappedMethodName(m.getName()) && m.isSource(storage, c);
+	private boolean needsIntermediaryName(ClassStorage storage, JarClassEntry cls, JarFieldEntry fld) {
+		return needsIntermediaryName((plugin) -> plugin.needsIntermediaryName(storage, cls, fld));
 	}
 
-	public static boolean isUnmappedMethodName(String name) {
-		return (name.length() <= 2 || (name.length() == 3 && name.charAt(2) == '_'))
-				&& name.charAt(0) != '<';
+	private boolean needsIntermediaryName(ClassStorage storage, JarClassEntry cls, JarMethodEntry mth) {
+		return needsIntermediaryName((plugin) -> plugin.needsIntermediaryName(storage, cls, mth));
 	}
 
 	@Nullable
 	private String getFieldName(ClassStorage storage, JarClassEntry c, JarFieldEntry f) {
-		if (!isMappedField(storage, c, f)) {
+		if (!needsIntermediaryName(storage, c, f)) {
 			return null;
 		}
 
@@ -354,7 +370,7 @@ private void findNames(ClassStorage storageOld, ClassStorage storageNew, JarClas
 
 	@Nullable
 	private String getMethodName(ClassStorage storageOld, ClassStorage storageNew, JarClassEntry c, JarMethodEntry m) {
-		if (!isMappedMethod(storageNew, c, m)) {
+		if (!needsIntermediaryName(storageNew, c, m)) {
 			return null;
 		}
 
@@ -435,7 +451,7 @@ private void addClass(JarClassEntry c, ClassStorage storageOld, ClassStorage sto
 			// an intermediary name, so we just leave it as is and
 			// don't add a prefix.
 			prefix = "";
-		} else if (!isMappedClass(storage, c)) {
+		} else if (!needsIntermediaryName(storage, c)) {
 			cName = c.getName();
 		} else {
 			cName = null;

src/main/java/net/fabricmc/stitch/plugin/PluginLoader.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.fabricmc.stitch.plugin;
+
+import java.util.ServiceLoader;
+
+public class PluginLoader {
+	public static void loadPlugins() {
+		Iterable<StitchPlugin> plugins = ServiceLoader.load(StitchPlugin.class);
+
+		for (StitchPlugin plugin : plugins) {
+			PluginRegistry.registerPlugin(plugin);
+		}
+
+		// Register default plugin
+		PluginRegistry.registerPlugin(new StitchPlugin() {
+		});
+	}
+}

src/main/java/net/fabricmc/stitch/plugin/PluginRegistry.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.fabricmc.stitch.plugin;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class PluginRegistry {
+	private static List<StitchPlugin> plugins = new ArrayList<>(5);
+
+	public static void registerPlugin(StitchPlugin plugin) {
+		plugins.add(plugin);
+	}
+
+	public static List<StitchPlugin> getPlugins() {
+		return plugins;
+	}
+}