fix: improve class renaming and add checks for class alias usage (#532)

jadx-core/src/main/java/jadx/core/codegen/ClassGen.java

@@ -36,6 +36,7 @@
 import jadx.core.utils.ErrorsCounter;
 import jadx.core.utils.Utils;
 import jadx.core.utils.exceptions.CodegenException;
+import jadx.core.utils.exceptions.JadxRuntimeException;
 
 public class ClassGen {
 
@@ -141,7 +142,7 @@ public void addClassDeclaration(CodeWriter clsCode) {
 			clsCode.add("class ");
 		}
 		clsCode.attachDefinition(cls);
-		clsCode.add(cls.getShortName());
+		clsCode.add(cls.getAlias().getShortName());
 
 		addGenericMap(clsCode, cls.getGenericMap(), true);
 		clsCode.add(' ');
@@ -199,9 +200,8 @@ public boolean addGenericMap(CodeWriter code, Map<ArgType, List<ArgType>> gmap,
 						code.add(g.getObject());
 					} else {
 						useClass(code, g);
-
 						if (classDeclaration && !cls.getAlias().isInner()) {
-							addImport(ClassInfo.extCls(cls.root(), g));
+							addImport(ClassInfo.fromType(cls.root(), g));
 						}
 					}
 					if (it.hasNext()) {
@@ -462,7 +462,7 @@ public void useType(CodeWriter code, ArgType type) {
 	}
 
 	public void useClass(CodeWriter code, ArgType type) {
-		useClass(code, ClassInfo.extCls(cls.root(), type));
+		useClass(code, ClassInfo.fromType(cls.root(), type));
 		ArgType[] generics = type.getGenericTypes();
 		if (generics != null) {
 			code.add('<');
@@ -503,16 +503,16 @@ public void useClass(CodeWriter code, ClassNode classNode) {
 	}
 
 	private void addClsName(CodeWriter code, ClassInfo classInfo) {
-		String clsName = useClassInternal(cls.getAlias(), classInfo.getAlias());
+		String clsName = useClassInternal(cls.getClassInfo(), classInfo);
 		code.add(clsName);
 	}
 
 	private String useClassInternal(ClassInfo useCls, ClassInfo extClsInfo) {
-		String fullName = extClsInfo.getFullName();
+		String fullName = extClsInfo.getAlias().makeFullName();
 		if (fallback || !useImports) {
 			return fullName;
 		}
-		String shortName = extClsInfo.getShortName();
+		String shortName = extClsInfo.getAlias().getShortName();
 		if (extClsInfo.getPackage().equals("java.lang") && extClsInfo.getParentClass() == null) {
 			return shortName;
 		}
@@ -538,14 +538,14 @@ private String useClassInternal(ClassInfo useCls, ClassInfo extClsInfo) {
 		if (extClsInfo.isDefaultPackage()) {
 			return shortName;
 		}
-		if (extClsInfo.getPackage().equals(useCls.getPackage())) {
-			fullName = extClsInfo.getNameWithoutPackage();
+		if (extClsInfo.getAlias().getPackage().equals(useCls.getAlias().getPackage())) {
+			fullName = extClsInfo.getAlias().getNameWithoutPackage();
 		}
 		for (ClassInfo importCls : getImports()) {
 			if (!importCls.equals(extClsInfo)
-					&& importCls.getShortName().equals(shortName)) {
+					&& importCls.getAlias().getShortName().equals(shortName)) {
 				if (extClsInfo.isInner()) {
-					String parent = useClassInternal(useCls, extClsInfo.getParentClass().getAlias());
+					String parent = useClassInternal(useCls, extClsInfo.getParentClass());
 					return parent + '.' + shortName;
 				} else {
 					return fullName;
@@ -558,8 +558,11 @@ private String useClassInternal(ClassInfo useCls, ClassInfo extClsInfo) {
 
 	private void addImport(ClassInfo classInfo) {
 		if (parentGen != null) {
-			parentGen.addImport(classInfo.getAlias());
+			parentGen.addImport(classInfo);
 		} else {
+			if (classInfo.isAlias()) {
+				throw new JadxRuntimeException("Don't add aliases class info to import list: " + classInfo);
+			}
 			imports.add(classInfo);
 		}
 	}
@@ -594,15 +597,15 @@ private static boolean searchCollision(DexNode dex, ClassInfo useCls, ClassInfo
 		if (useCls == null) {
 			return false;
 		}
-		String shortName = searchCls.getShortName();
-		if (useCls.getShortName().equals(shortName)) {
+		String shortName = searchCls.getAlias().getShortName();
+		if (useCls.getAlias().getShortName().equals(shortName)) {
 			return true;
 		}
 		ClassNode classNode = dex.resolveClass(useCls);
 		if (classNode != null) {
 			for (ClassNode inner : classNode.getInnerClasses()) {
-				if (inner.getShortName().equals(shortName)
-						&& !inner.getAlias().equals(searchCls)) {
+				if (inner.getAlias().getShortName().equals(shortName)
+						&& !inner.getAlias().equals(searchCls.getAlias())) {
 					return true;
 				}
 			}

jadx-core/src/main/java/jadx/core/codegen/MethodGen.java

@@ -13,7 +13,6 @@
 import jadx.core.dex.attributes.annotations.MethodParameters;
 import jadx.core.dex.attributes.nodes.JumpInfo;
 import jadx.core.dex.info.AccessInfo;
-import jadx.core.dex.info.ClassInfo;
 import jadx.core.dex.instructions.IfNode;
 import jadx.core.dex.instructions.InsnType;
 import jadx.core.dex.instructions.args.ArgType;
@@ -180,10 +179,8 @@ public void addInstructions(CodeWriter code) throws CodegenException {
 			addFallbackMethodCode(code);
 			code.startLine("*/");
 
-			ClassInfo clsAlias = mth.getParentClass().getAlias();
-
 			code.startLine("throw new UnsupportedOperationException(\"Method not decompiled: ")
-					.add(clsAlias.makeFullClsName(clsAlias.getShortName(), true))
+					.add(mth.getParentClass().getAlias().makeFullName())
 					.add('.')
 					.add(mth.getAlias())
 					.add('(')

jadx-core/src/main/java/jadx/core/codegen/NameGen.java

@@ -177,12 +177,15 @@ private static String makeNameForPrimitive(ArgType type) {
 	}
 
 	private String makeNameForObject(ArgType type) {
+		if (type.isGenericType()) {
+			return StringUtils.escape(type.getObject().toLowerCase());
+		}
 		if (type.isObject()) {
 			String alias = getAliasForObject(type.getObject());
 			if (alias != null) {
 				return alias;
 			}
-			ClassInfo extClsInfo = ClassInfo.extCls(mth.root(), type);
+			ClassInfo extClsInfo = ClassInfo.fromType(mth.root(), type);
 			String shortName = extClsInfo.getShortName();
 			String vName = fromName(shortName);
 			if (vName != null) {

jadx-core/src/main/java/jadx/core/deobf/Deobfuscator.java

@@ -232,7 +232,7 @@ private void processClass(ClassNode cls) {
 		ClassInfo clsInfo = cls.getClassInfo();
 		String fullName = getClassFullName(clsInfo);
 		if (!fullName.equals(clsInfo.getFullName())) {
-			clsInfo.rename(cls.dex().root(), fullName);
+			clsInfo.rename(cls.root(), fullName);
 		}
 		for (FieldNode field : cls.getFields()) {
 			if (field.contains(AFlag.DONT_RENAME)) {

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

@@ -1,8 +1,10 @@
 package jadx.core.dex.info;
 
 import java.io.File;
+import java.util.Objects;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import jadx.core.dex.instructions.args.ArgType;
 import jadx.core.dex.nodes.DexNode;
@@ -20,30 +22,53 @@ public final class ClassInfo implements Comparable<ClassInfo> {
 	// class info after rename (deobfuscation)
 	private ClassInfo alias;
 
+	private ClassInfo(ArgType type) {
+		this.type = checkClassType(type);
+		this.alias = this;
+	}
+
 	private ClassInfo(RootNode root, ArgType type) {
 		this(root, type, true);
 	}
 
 	private ClassInfo(RootNode root, ArgType type, boolean inner) {
-		if (!type.isObject() || type.isGeneric()) {
-			throw new JadxRuntimeException("Not class type: " + type);
-		}
-		this.type = type;
-		this.alias = this;
+		this(type);
+		splitAndApplyNames(root, type, inner);
+	}
 
-		splitNames(root, inner);
+	private ClassInfo(ArgType type, String pkg, String name, @Nullable ClassInfo parentClass) {
+		this(type);
+		this.pkg = pkg;
+		this.name = name;
+		this.parentClass = parentClass;
+		this.fullName = makeFullClsName(name, false);
 	}
 
 	public static ClassInfo fromType(RootNode root, ArgType type) {
-		if (type.isArray()) {
-			type = ArgType.OBJECT;
-		}
-		ClassInfo cls = root.getInfoStorage().getCls(type);
+		ArgType clsType = checkClassType(type);
+		ClassInfo cls = root.getInfoStorage().getCls(clsType);
 		if (cls != null) {
 			return cls;
 		}
-		cls = new ClassInfo(root, type);
-		return root.getInfoStorage().putCls(cls);
+		ClassInfo newClsInfo = new ClassInfo(root, clsType);
+		return root.getInfoStorage().putCls(newClsInfo);
+	}
+
+	private static ArgType checkClassType(ArgType type) {
+		if (type == null) {
+			throw new JadxRuntimeException("Null class type");
+		}
+		if (type.isArray()) {
+			// TODO: check case with method declared in array class like ( clone in int[])
+			return ArgType.OBJECT;
+		}
+		if (!type.isObject() || type.isGenericType()) {
+			throw new JadxRuntimeException("Not class type: " + type);
+		}
+		if (type.isGeneric()) {
+			return ArgType.object(type.getObject());
+		}
+		return type;
 	}
 
 	public static ClassInfo fromDex(DexNode dex, int clsIndex) {
@@ -57,19 +82,27 @@ public static ClassInfo fromName(RootNode root, String clsName) {
 		return fromType(root, ArgType.object(clsName));
 	}
 
-	public static ClassInfo extCls(RootNode root, ArgType type) {
-		ClassInfo classInfo = fromName(root, type.getObject());
-		return classInfo.alias;
+	public void rename(RootNode root, String fullName) {
+		if (!alias.makeFullName().equals(fullName)) {
+			ClassInfo newAlias = new ClassInfo(type);
+			newAlias.splitAndApplyNames(root, fullName, isInner());
+			newAlias.alias = null;
+			this.alias = newAlias;
+		}
 	}
 
-	public void rename(RootNode root, String fullName) {
-		ArgType clsType = ArgType.object(fullName);
-		ClassInfo newAlias = root.getInfoStorage().getCls(clsType);
-		if (newAlias == null) {
-			newAlias = new ClassInfo(root, clsType, isInner());
-			root.getInfoStorage().putCls(newAlias);
+	public void renameShortName(String aliasName) {
+		if (!Objects.equals(name, aliasName)) {
+			ClassInfo newAlias = new ClassInfo(type, alias.pkg, aliasName, parentClass);
+			newAlias.alias = null;
+			this.alias = newAlias;
 		}
-		if (!alias.getFullName().equals(newAlias.getFullName())) {
+	}
+
+	public void renamePkg(String aliasPkg) {
+		if (!Objects.equals(pkg, aliasPkg)) {
+			ClassInfo newAlias = new ClassInfo(type, aliasPkg, alias.name, parentClass);
+			newAlias.alias = null;
 			this.alias = newAlias;
 		}
 	}
@@ -78,11 +111,18 @@ public boolean isRenamed() {
 	}
 
 	public ClassInfo getAlias() {
-		return alias;
+		return alias == null ? this : alias;
+	}
+
+	public boolean isAlias() {
+		return alias == null;
 	}
 
-	private void splitNames(RootNode root, boolean canBeInner) {
-		String fullObjectName = type.getObject();
+	private void splitAndApplyNames(RootNode root, ArgType type, boolean canBeInner) {
+		splitAndApplyNames(root, type.getObject(), canBeInner);
+	}
+
+	private void splitAndApplyNames(RootNode root, String fullObjectName, boolean canBeInner) {
 		String clsName;
 		int dot = fullObjectName.lastIndexOf('.');
 		if (dot == -1) {
@@ -109,14 +149,18 @@ private void splitNames(RootNode root, boolean canBeInner) {
 		this.fullName = makeFullClsName(clsName, false);
 	}
 
-	public String makeFullClsName(String shortName, boolean raw) {
+	private String makeFullClsName(String shortName, boolean raw) {
 		if (parentClass != null) {
 			String innerSep = raw ? "$" : ".";
 			return parentClass.makeFullClsName(parentClass.getShortName(), raw) + innerSep + shortName;
 		}
 		return pkg.isEmpty() ? shortName : pkg + '.' + shortName;
 	}
 
+	public String makeFullName() {
+		return makeFullClsName(this.name, false);
+	}
+
 	public String makeRawFullName() {
 		return makeFullClsName(this.name, true);
 	}
@@ -129,7 +173,7 @@ public String getFullPath() {
 	}
 
 	public String getFullName() {
-		return fullName;
+		return makeFullName();
 	}
 
 	public String getShortName() {
@@ -172,11 +216,12 @@ public boolean isInner() {
 	}
 
 	public void notInner(RootNode root) {
-		splitNames(root, false);
+		this.parentClass = null;
+		splitAndApplyNames(root, type, false);
 	}
 
 	public void updateNames(RootNode root) {
-		splitNames(root, isInner());
+		splitAndApplyNames(root, type, isInner());
 	}
 
 	public ArgType getType() {
@@ -185,7 +230,7 @@ public ArgType getType() {
 
 	@Override
 	public String toString() {
-		return fullName;
+		return makeFullName();
 	}
 
 	@Override

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

@@ -24,6 +24,7 @@
 import jadx.core.dex.info.FieldInfo;
 import jadx.core.dex.info.MethodInfo;
 import jadx.core.dex.instructions.args.ArgType;
+import jadx.core.utils.exceptions.JadxRuntimeException;
 import jadx.core.utils.files.DexFile;
 
 public class DexNode implements IDexNode {
@@ -93,6 +94,9 @@ public List<ClassNode> getClasses() {
 
 	@Nullable
 	ClassNode resolveClassLocal(ClassInfo clsInfo) {
+		if (clsInfo.isAlias()) {
+			throw new JadxRuntimeException("Don't resolve class by alias: " + clsInfo);
+		}
 		return clsMap.get(clsInfo);
 	}
 

jadx-core/src/main/java/jadx/core/dex/visitors/DependencyCollector.java

@@ -114,8 +114,8 @@ private static void processCustomInsn(DexNode dex, Set<ClassNode> depList, InsnN
 
 	private static void addDep(DexNode dex, Set<ClassNode> depList, ArgType type) {
 		if (type != null) {
-			if (type.isObject()) {
-				addDep(dex, depList, ClassInfo.fromName(dex.root(), type.getObject()));
+			if (type.isObject() && !type.isGenericType()) {
+				addDep(dex, depList, ClassInfo.fromType(dex.root(), type));
 				ArgType[] genericTypes = type.getGenericTypes();
 				if (type.isGeneric() && genericTypes != null) {
 					for (ArgType argType : genericTypes) {