Add JADX decompiler (#27)

* Add JADX decompiler

* Use memory cache for JADX

Speeds up things significantly. And yes, the memory is never reclaimed, but once we move the cache to the disk instead, that won't be an issue anymore

* Much more efficient JADX implementation

Now only passes the requested class instead of all input files.

* Fix crash on second decompile

* Un-`synchronize` JADX decompiling

* New JADX implementation can decompile inner classes

Also fix checkstyle issues

* Fix JPMS issues

* Put JADX menu entry underneath Vineflower

* Small clean-up

* Reduce JADX log spam

* Remove JADX repackaging top-level classes workaround

build.gradle

@@ -65,6 +65,12 @@ dependencies {
 	implementation "net.fabricmc:cfr:${fabric_cfr_version}"
 	implementation "org.vineflower:vineflower:${vineflower_version}"
 	implementation "org.bitbucket.mstrobel:procyon-compilertools:${procyon_version}"
+	implementation ("io.github.skylot:jadx-core:${jadx_version}") {
+		exclude group: 'com.android.tools.build', module: 'aapt2-proto'
+	}
+	implementation ("io.github.skylot:jadx-java-input:${jadx_version}") {
+		exclude group: 'io.github.skylot', module: 'raung-disasm'
+	}
 	runtimeOnly "org.tinylog:tinylog-impl:${tinylog_version}"
 	runtimeOnly "org.tinylog:slf4j-tinylog:${tinylog_version}"
 
@@ -97,6 +103,11 @@ extraJavaModuleInfo {
 
 	// Procyon
 	automaticModule("org.bitbucket.mstrobel:procyon-compilertools", "procyon.compilertools")
+
+	// JADX
+	automaticModule("io.github.skylot:jadx-core", "jadx.core")
+	automaticModule("io.github.skylot:jadx-plugins-api", "jadx.plugins.api")
+	automaticModule("io.github.skylot:jadx-java-input", "jadx.plugins.java_input")
 }
 
 application {

gradle.properties

@@ -14,6 +14,7 @@ asm_version = 9.6
 fabric_cfr_version = 0.2.1
 vineflower_version = 1.9.3
 procyon_version = 0.6.0
+jadx_version = 1.4.7
 mappingio_version = 0.5.0
 javaparser_version = 3.25.6
 javafx_version = 21.0.1

src/main/java/matcher/Util.java

@@ -2,6 +2,8 @@
 
 import java.io.Closeable;
 import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.io.UncheckedIOException;
 import java.net.URI;
 import java.net.URISyntaxException;
@@ -48,6 +50,15 @@ public static <T> Set<T> copySet(Set<T> set) {
 		}
 	}
 
+	public static String getStackTrace(Throwable t) {
+		if (t == null) return null;
+
+		StringWriter sw = new StringWriter();
+		PrintWriter pw = new PrintWriter(sw);
+		t.printStackTrace(pw);
+		return sw.toString();
+	}
+
 	public static FileSystem iterateJar(Path archive, boolean autoClose, Consumer<Path> handler) {
 		boolean existing = false;
 		FileSystem fs = null;

src/main/java/matcher/srcprocess/BuiltinDecompiler.java

@@ -5,6 +5,7 @@
 public enum BuiltinDecompiler {
 	CFR("CFR", Cfr::new),
 	VINEFLOWER("Vineflower", Vineflower::new),
+	JADX("JADX", Jadx::new),
 	PROCYON("Procyon", Procyon::new);
 
 	BuiltinDecompiler(String name, Supplier<? extends Decompiler> supplier) {

src/main/java/matcher/srcprocess/Jadx.java

@@ -0,0 +1,75 @@
+package matcher.srcprocess;
+
+import java.io.IOException;
+import java.util.function.Consumer;
+
+import jadx.api.CommentsLevel;
+import jadx.api.JadxArgs;
+import jadx.api.JadxDecompiler;
+import jadx.api.impl.NoOpCodeCache;
+import jadx.api.plugins.input.data.IClassData;
+import jadx.api.plugins.input.data.ILoadResult;
+import jadx.api.plugins.input.data.IResourceData;
+import jadx.plugins.input.java.JavaClassReader;
+import jadx.plugins.input.java.data.JavaClassData;
+
+import matcher.NameType;
+import matcher.Util;
+import matcher.type.ClassFeatureExtractor;
+import matcher.type.ClassInstance;
+
+public class Jadx implements Decompiler {
+	@Override
+	public String decompile(ClassInstance cls, ClassFeatureExtractor env, NameType nameType) {
+		String errorMessage = null;
+		final String fullClassName = cls.getName(NameType.PLAIN, true);
+
+		try (JadxDecompiler jadx = new JadxDecompiler(jadxArgs)) {
+			jadx.addCustomLoad(new ILoadResult() {
+				@Override
+				public void close() throws IOException { }
+
+				@Override
+				public void visitClasses(Consumer<IClassData> consumer) {
+					consumer.accept(new JavaClassData(new JavaClassReader(0,
+							fullClassName + ".class", cls.serialize(nameType))));
+				}
+
+				@Override
+				public void visitResources(Consumer<IResourceData> consumer) { }
+
+				@Override
+				public boolean isEmpty() {
+					return false;
+				}
+			});
+			jadx.load();
+
+			assert jadx.getClassesWithInners().size() == 1;
+			return jadx.getClassesWithInners().get(0).getCode();
+		} catch (Exception e) {
+			errorMessage = Util.getStackTrace(e);
+		}
+
+		throw new RuntimeException(errorMessage != null ? errorMessage : "JADX couldn't find the requested class");
+	}
+
+	private static final JadxArgs jadxArgs;
+
+	static {
+		jadxArgs = new JadxArgs() {
+			@Override
+			public void close() {
+				return;
+			}
+		};
+		jadxArgs.setCodeCache(NoOpCodeCache.INSTANCE);
+		jadxArgs.setShowInconsistentCode(true);
+		jadxArgs.setInlineAnonymousClasses(false);
+		jadxArgs.setInlineMethods(false);
+		jadxArgs.setSkipResources(true);
+		jadxArgs.setRenameValid(false);
+		jadxArgs.setRespectBytecodeAccModifiers(true);
+		jadxArgs.setCommentsLevel(CommentsLevel.INFO);
+	}
+}

src/main/java/module-info.java

@@ -26,6 +26,9 @@
 	requires org.objectweb.asm.tree.analysis;
 	requires org.objectweb.asm.util;
 	requires procyon.compilertools;
+	requires jadx.core;
+	requires jadx.plugins.api;
+	requires jadx.plugins.java_input;
 	requires transitive net.fabricmc.mappingio;
 
 	uses matcher.Plugin;

src/main/resources/tinylog-dev.properties

@@ -1,3 +1,5 @@
 writer = console
 writer.format = {date: HH:mm:ss.SSS} [{thread}/{level}]: {message}
 writer.level = debug
+
+level@jadx = warn

src/main/resources/tinylog.properties

@@ -1,3 +1,5 @@
 writer = console
 writer.format = {date: HH:mm:ss} [{level}]: {message}
 writer.level = info
+
+level@jadx = error