Support for exporting to proper deobfuscation mapping file formats

build.gradle

@@ -49,6 +49,11 @@ allprojects {
 		mavenLocal()
 		mavenCentral()
 		google()
+		// Commented out for now since we're using a local mapping-io fork atm.
+        // maven {
+		// 	name 'FabricMC'
+		// 	url 'https://maven.fabricmc.net/'
+		// }
 	}
 }
 

jadx-core/src/main/java/jadx/core/dex/info/ClassInfo.java

@@ -180,12 +180,12 @@ public String makeRawFullName() {
 		return makeFullClsName(pkg, name, parentClass, false, true);
 	}
 
-	private String makeAliasFullName() {
+	public String makeAliasFullName() {
 		return makeFullClsName(getAliasPkg(), getAliasShortName(), parentClass, true, false);
 	}
 
-	private String makeAliasRawFullName() {
-		return makeFullClsName(pkg, name, parentClass, true, true);
+	public String makeAliasRawFullName() {
+		return makeFullClsName(getAliasPkg(), getAliasShortName(), parentClass, true, true);
 	}
 
 	public String getAliasFullPath() {

jadx-core/src/main/java/jadx/core/dex/nodes/MethodNode.java

@@ -461,6 +461,10 @@ public int getRegsCount() {
 		return regsCount;
 	}
 
+	public int getArgsStartReg() {
+		return argsStartReg;
+	}
+
 	public SSAVar makeNewSVar(@NotNull RegisterArg assignArg) {
 		int regNum = assignArg.getRegNum();
 		return makeNewSVar(regNum, getNextSVarVersion(regNum), assignArg);

jadx-gui/build.gradle

@@ -7,7 +7,6 @@ plugins {
 
 dependencies {
 	implementation(project(':jadx-core'))
-
 	implementation(project(":jadx-cli"))
 	implementation 'com.beust:jcommander:1.82'
 	implementation 'ch.qos.logback:logback-classic:1.2.11'
@@ -30,6 +29,11 @@ dependencies {
 	implementation 'com.android.tools.build:apksig:4.2.1'
 	implementation 'io.github.hqktech:jdwp:1.0'
 
+	// TODO: Switch back to upstream once this PR gets merged:
+	//   https://github.com/FabricMC/mapping-io/pull/19
+	// implementation 'net.fabricmc:mapping-io:0.3.0'
+	implementation files('libs/mapping-io-0.4.0-SNAPSHOT.jar')
+
 	testImplementation project(":jadx-core").sourceSets.test.output
 }
 

jadx-gui/src/main/java/jadx/gui/plugins/mappings/MappingExporter.java

@@ -0,0 +1,285 @@
+package jadx.gui.plugins.mappings;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.AbstractMap.SimpleEntry;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import net.fabricmc.mappingio.MappedElementKind;
+import net.fabricmc.mappingio.MappingWriter;
+import net.fabricmc.mappingio.format.MappingFormat;
+import net.fabricmc.mappingio.tree.MemoryMappingTree;
+
+import jadx.api.ICodeInfo;
+import jadx.api.data.ICodeComment;
+import jadx.api.data.ICodeRename;
+import jadx.api.data.IJavaNodeRef.RefType;
+import jadx.api.data.impl.JadxCodeData;
+import jadx.api.data.impl.JadxCodeRef;
+import jadx.api.metadata.ICodeNodeRef;
+import jadx.api.metadata.annotations.InsnCodeOffset;
+import jadx.api.metadata.annotations.NodeDeclareRef;
+import jadx.api.metadata.annotations.VarNode;
+import jadx.api.utils.CodeUtils;
+import jadx.core.Consts;
+import jadx.core.codegen.TypeGen;
+import jadx.core.dex.info.ClassInfo;
+import jadx.core.dex.info.FieldInfo;
+import jadx.core.dex.info.MethodInfo;
+import jadx.core.dex.nodes.ClassNode;
+import jadx.core.dex.nodes.FieldNode;
+import jadx.core.dex.nodes.MethodNode;
+import jadx.core.dex.nodes.RootNode;
+import jadx.core.utils.files.FileUtils;
+
+public class MappingExporter {
+	private static final Logger LOG = LoggerFactory.getLogger(MappingExporter.class);
+	private final RootNode root;
+
+	public MappingExporter(RootNode rootNode) {
+		this.root = rootNode;
+	}
+
+	private List<VarNode> collectMethodArgs(MethodNode methodNode) {
+		ICodeInfo codeInfo = methodNode.getTopParentClass().getCode();
+		int mthDefPos = methodNode.getDefPosition();
+		int lineEndPos = CodeUtils.getLineEndForPos(codeInfo.getCodeStr(), mthDefPos);
+		List<VarNode> args = new ArrayList<>();
+		codeInfo.getCodeMetadata().searchDown(mthDefPos, (pos, ann) -> {
+			if (pos > lineEndPos) {
+				// Stop at line end
+				return Boolean.TRUE;
+			}
+			if (ann instanceof NodeDeclareRef) {
+				ICodeNodeRef declRef = ((NodeDeclareRef) ann).getNode();
+				if (declRef instanceof VarNode) {
+					VarNode varNode = (VarNode) declRef;
+					if (!varNode.getMth().equals(methodNode)) {
+						// Stop if we've gone too far and have entered a different method
+						return Boolean.TRUE;
+					}
+					args.add(varNode);
+				}
+			}
+			return null;
+		});
+		return args;
+	}
+
+	private List<SimpleEntry<VarNode, Integer>> collectMethodVars(MethodNode methodNode) {
+		ICodeInfo codeInfo = methodNode.getTopParentClass().getCode();
+		int mthDefPos = methodNode.getDefPosition();
+		int mthLineEndPos = CodeUtils.getLineEndForPos(codeInfo.getCodeStr(), mthDefPos);
+
+		List<SimpleEntry<VarNode, Integer>> vars = new ArrayList<>();
+		AtomicInteger lastOffset = new AtomicInteger(-1);
+		codeInfo.getCodeMetadata().searchDown(mthLineEndPos, (pos, ann) -> {
+			if (ann instanceof InsnCodeOffset) {
+				lastOffset.set(((InsnCodeOffset) ann).getOffset());
+			}
+			if (ann instanceof NodeDeclareRef) {
+				ICodeNodeRef declRef = ((NodeDeclareRef) ann).getNode();
+				if (declRef instanceof VarNode) {
+					VarNode varNode = (VarNode) declRef;
+					if (!varNode.getMth().equals(methodNode)) {
+						// Stop if we've gone too far and have entered a different method
+						return Boolean.TRUE;
+					}
+					if (lastOffset.get() != -1) {
+						vars.add(new SimpleEntry<VarNode, Integer>(varNode, lastOffset.get()));
+					} else {
+						LOG.warn("Local variable not present in bytecode, skipping: "
+								+ methodNode.getMethodInfo().getRawFullId() + "#" + varNode.getName());
+					}
+					lastOffset.set(-1);
+				}
+			}
+			return null;
+		});
+		return vars;
+	}
+
+	public void exportMappings(Path path, JadxCodeData codeData, MappingFormat mappingFormat) {
+		MemoryMappingTree mappingTree = new MemoryMappingTree();
+		// Map < SrcName >
+		Set<String> mappedClasses = new HashSet<>();
+		// Map < DeclClass + ShortId >
+		Set<String> mappedFields = new HashSet<>();
+		Set<String> mappedMethods = new HashSet<>();
+		Set<String> methodsWithMappedElements = new HashSet<>();
+		// Map < DeclClass + MethodShortId + CodeRef, NewName >
+		Map<String, String> mappedMethodArgsAndVars = new HashMap<>();
+		// Map < DeclClass + *ShortId + *CodeRef, Comment >
+		Map<String, String> comments = new HashMap<>();
+
+		// We have to do this so we know for sure which elements are *manually* renamed
+		for (ICodeRename codeRename : codeData.getRenames()) {
+			if (codeRename.getNodeRef().getType().equals(RefType.CLASS)) {
+				mappedClasses.add(codeRename.getNodeRef().getDeclaringClass());
+			} else if (codeRename.getNodeRef().getType().equals(RefType.FIELD)) {
+				mappedFields.add(codeRename.getNodeRef().getDeclaringClass() + codeRename.getNodeRef().getShortId());
+			} else if (codeRename.getNodeRef().getType().equals(RefType.METHOD)) {
+				if (codeRename.getCodeRef() == null) {
+					mappedMethods.add(codeRename.getNodeRef().getDeclaringClass() + codeRename.getNodeRef().getShortId());
+				} else {
+					methodsWithMappedElements.add(codeRename.getNodeRef().getDeclaringClass() + codeRename.getNodeRef().getShortId());
+					mappedMethodArgsAndVars.put(codeRename.getNodeRef().getDeclaringClass()
+							+ codeRename.getNodeRef().getShortId()
+							+ codeRename.getCodeRef(),
+							codeRename.getNewName());
+				}
+			}
+		}
+		for (ICodeComment codeComment : codeData.getComments()) {
+			comments.put(codeComment.getNodeRef().getDeclaringClass()
+					+ (codeComment.getNodeRef().getShortId() == null ? "" : codeComment.getNodeRef().getShortId())
+					+ (codeComment.getCodeRef() == null ? "" : codeComment.getCodeRef()),
+					codeComment.getComment());
+			if (codeComment.getCodeRef() != null) {
+				methodsWithMappedElements.add(codeComment.getNodeRef().getDeclaringClass() + codeComment.getNodeRef().getShortId());
+			}
+		}
+
+		try {
+			if (mappingFormat.hasSingleFile()) {
+				if (path.toFile().exists()) {
+					path.toFile().delete();
+				}
+				path.toFile().createNewFile();
+			} else {
+				FileUtils.makeDirs(path);
+			}
+
+			mappingTree.visitHeader();
+			mappingTree.visitNamespaces("official", Arrays.asList("named"));
+			mappingTree.visitContent();
+
+			for (ClassNode cls : root.getClasses()) {
+				ClassInfo classInfo = cls.getClassInfo();
+				String classPath = classInfo.makeRawFullName().replace('.', '/');
+				String rawClassName = classInfo.getRawName();
+
+				if (classInfo.hasAlias()
+						&& !classInfo.getAliasShortName().equals(classInfo.getShortName())
+						&& mappedClasses.contains(rawClassName)) {
+					mappingTree.visitClass(classPath);
+					String alias = classInfo.makeAliasRawFullName().replace('.', '/');
+
+					if (alias.startsWith(Consts.DEFAULT_PACKAGE_NAME)) {
+						alias = alias.substring(Consts.DEFAULT_PACKAGE_NAME.length() + 1);
+					}
+					mappingTree.visitDstName(MappedElementKind.CLASS, 0, alias);
+				}
+				if (comments.containsKey(rawClassName)) {
+					mappingTree.visitClass(classPath);
+					mappingTree.visitComment(MappedElementKind.CLASS, comments.get(rawClassName));
+				}
+
+				for (FieldNode fld : cls.getFields()) {
+					FieldInfo fieldInfo = fld.getFieldInfo();
+					if (fieldInfo.hasAlias() && mappedFields.contains(rawClassName + fieldInfo.getShortId())) {
+						visitField(mappingTree, classPath, fieldInfo.getName(), TypeGen.signature(fieldInfo.getType()));
+						mappingTree.visitDstName(MappedElementKind.FIELD, 0, fieldInfo.getAlias());
+					}
+					if (comments.containsKey(rawClassName + fieldInfo.getShortId())) {
+						visitField(mappingTree, classPath, fieldInfo.getName(), TypeGen.signature(fieldInfo.getType()));
+						mappingTree.visitComment(MappedElementKind.FIELD, comments.get(rawClassName + fieldInfo.getShortId()));
+					}
+				}
+
+				for (MethodNode mth : cls.getMethods()) {
+					MethodInfo methodInfo = mth.getMethodInfo();
+					String methodName = methodInfo.getName();
+					String methodDesc = methodInfo.getShortId().substring(methodName.length());
+					if (methodInfo.hasAlias() && mappedMethods.contains(rawClassName + methodInfo.getShortId())) {
+						visitMethod(mappingTree, classPath, methodName, methodDesc);
+						mappingTree.visitDstName(MappedElementKind.METHOD, 0, methodInfo.getAlias());
+					}
+					if (comments.containsKey(rawClassName + methodInfo.getShortId())) {
+						visitMethod(mappingTree, classPath, methodName, methodDesc);
+						mappingTree.visitComment(MappedElementKind.METHOD, comments.get(rawClassName + methodInfo.getShortId()));
+					}
+
+					if (!methodsWithMappedElements.contains(rawClassName + methodInfo.getShortId())) {
+						continue;
+					}
+					// Method args
+					int lvtIndex = mth.getAccessFlags().isStatic() ? 0 : 1;
+					int lastArgLvIndex = lvtIndex - 1;
+					List<VarNode> args = collectMethodArgs(mth);
+					for (VarNode arg : args) {
+						int lvIndex = arg.getReg() - args.get(0).getReg() + (mth.getAccessFlags().isStatic() ? 0 : 1);
+						String key = rawClassName + methodInfo.getShortId()
+								+ JadxCodeRef.forVar(arg.getReg(), arg.getSsa());
+						if (mappedMethodArgsAndVars.containsKey(key)) {
+							visitMethodArg(mappingTree, classPath, methodName, methodDesc, args.indexOf(arg), lvIndex);
+							mappingTree.visitDstName(MappedElementKind.METHOD_ARG, 0, mappedMethodArgsAndVars.get(key));
+							mappedMethodArgsAndVars.remove(key);
+						}
+						lastArgLvIndex = lvIndex;
+						lvtIndex++;
+						// Not checking for comments since method args can't have any
+					}
+					// Method vars
+					List<SimpleEntry<VarNode, Integer>> vars = collectMethodVars(mth);
+					for (SimpleEntry<VarNode, Integer> entry : vars) {
+						VarNode var = entry.getKey();
+						int offset = entry.getValue();
+						int lvIndex = lastArgLvIndex + var.getReg() + (mth.getAccessFlags().isStatic() ? 0 : 1);
+						String key = rawClassName + methodInfo.getShortId()
+								+ JadxCodeRef.forVar(var.getReg(), var.getSsa());
+						if (mappedMethodArgsAndVars.containsKey(key)) {
+							visitMethodVar(mappingTree, classPath, methodName, methodDesc, lvtIndex, lvIndex, offset);
+							mappingTree.visitDstName(MappedElementKind.METHOD_VAR, 0, mappedMethodArgsAndVars.get(key));
+						}
+						key = rawClassName + methodInfo.getShortId() + JadxCodeRef.forInsn(offset);
+						if (comments.containsKey(key)) {
+							visitMethodVar(mappingTree, classPath, methodName, methodDesc, lvtIndex, lvIndex, offset);
+							mappingTree.visitComment(MappedElementKind.METHOD_VAR, comments.get(key));
+						}
+						lvtIndex++;
+					}
+				}
+			}
+
+			MappingWriter writer = MappingWriter.create(path, mappingFormat);
+			mappingTree.accept(writer);
+			mappingTree.visitEnd();
+			writer.close();
+		} catch (IOException e) {
+			LOG.error("Failed to save deobfuscation map file '{}'", path.toAbsolutePath(), e);
+		}
+	}
+
+	private void visitField(MemoryMappingTree tree, String classPath, String srcName, String srcDesc) {
+		tree.visitClass(classPath);
+		tree.visitField(srcName, srcDesc);
+	}
+
+	private void visitMethod(MemoryMappingTree tree, String classPath, String srcName, String srcDesc) {
+		tree.visitClass(classPath);
+		tree.visitMethod(srcName, srcDesc);
+	}
+
+	private void visitMethodArg(MemoryMappingTree tree, String classPath, String methodSrcName, String methodSrcDesc, int argPosition,
+			int lvIndex) {
+		visitMethod(tree, classPath, methodSrcName, methodSrcDesc);
+		tree.visitMethodArg(argPosition, lvIndex, null);
+	}
+
+	private void visitMethodVar(MemoryMappingTree tree, String classPath, String methodSrcName, String methodSrcDesc, int lvtIndex,
+			int lvIndex, int startOpIdx) {
+		visitMethod(tree, classPath, methodSrcName, methodSrcDesc);
+		tree.visitMethodVar(lvtIndex, lvIndex, startOpIdx, null);
+	}
+}