fix: support multi-exception catch blocks (#421)

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

@@ -1,5 +1,6 @@
 package jadx.core.codegen;
 
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
@@ -11,6 +12,7 @@
 import jadx.core.dex.attributes.nodes.DeclareVariablesAttr;
 import jadx.core.dex.attributes.nodes.ForceReturnAttr;
 import jadx.core.dex.attributes.nodes.LoopLabelAttr;
+import jadx.core.dex.info.ClassInfo;
 import jadx.core.dex.instructions.SwitchNode;
 import jadx.core.dex.instructions.args.InsnArg;
 import jadx.core.dex.instructions.args.NamedArg;
@@ -306,16 +308,23 @@ private void makeCatchBlock(CodeWriter code, ExceptionHandler handler) throws Co
 			return;
 		}
 		code.startLine("} catch (");
+		if (handler.isCatchAll()) {
+			code.add("Throwable");
+		} else {
+			Iterator<ClassInfo> it = handler.getCatchTypes().iterator();
+			if (it.hasNext()) {
+				useClass(code, it.next());
+			}
+			while (it.hasNext()) {
+				code.add(" | ");
+				useClass(code, it.next());
+			}
+		}
+		code.add(' ');
 		InsnArg arg = handler.getArg();
 		if (arg instanceof RegisterArg) {
-			declareVar(code, (RegisterArg) arg);
+			code.add(mgen.getNameGen().assignArg((RegisterArg) arg));
 		} else if (arg instanceof NamedArg) {
-			if (handler.isCatchAll()) {
-				code.add("Throwable");
-			} else {
-				useClass(code, handler.getCatchType());
-			}
-			code.add(' ');
 			code.add(mgen.getNameGen().assignNamedArg((NamedArg) arg));
 		}
 		code.add(") {");

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

@@ -2,12 +2,14 @@
 
 import java.io.File;
 
+import org.jetbrains.annotations.NotNull;
+
 import jadx.core.dex.instructions.args.ArgType;
 import jadx.core.dex.nodes.DexNode;
 import jadx.core.dex.nodes.RootNode;
 import jadx.core.utils.exceptions.JadxRuntimeException;
 
-public final class ClassInfo {
+public final class ClassInfo implements Comparable<ClassInfo> {
 
 	private final ArgType type;
 	private String pkg;
@@ -194,4 +196,9 @@ public boolean equals(Object obj) {
 		}
 		return false;
 	}
+
+	@Override
+	public int compareTo(@NotNull ClassInfo o) {
+		return fullName.compareTo(o.fullName);
+	}
 }

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

@@ -96,16 +96,16 @@ public void load() throws DecodeException {
 
 			DexNode dex = parentClass.dex();
 			Code mthCode = dex.readCode(methodData);
-			regsCount = mthCode.getRegistersSize();
+			this.regsCount = mthCode.getRegistersSize();
 			initMethodTypes();
 
 			InsnDecoder decoder = new InsnDecoder(this);
 			decoder.decodeInsns(mthCode);
-			instructions = decoder.process();
-			codeSize = instructions.length;
+			this.instructions = decoder.process();
+			this.codeSize = instructions.length;
 
-			initTryCatches(mthCode);
-			initJumps();
+			initTryCatches(this, mthCode, instructions);
+			initJumps(instructions);
 
 			this.debugInfoOffset = mthCode.getDebugInfoOffset();
 		} catch (Exception e) {
@@ -257,45 +257,45 @@ public Map<ArgType, List<ArgType>> getGenericMap() {
 		return genericMap;
 	}
 
-	private void initTryCatches(Code mthCode) {
-		InsnNode[] insnByOffset = instructions;
+	private static void initTryCatches(MethodNode mth, Code mthCode, InsnNode[] insnByOffset) {
 		CatchHandler[] catchBlocks = mthCode.getCatchHandlers();
 		Try[] tries = mthCode.getTries();
 		if (catchBlocks.length == 0 && tries.length == 0) {
 			return;
 		}
 
-		int hc = 0;
+		int handlersCount = 0;
 		Set<Integer> addrs = new HashSet<>();
 		List<TryCatchBlock> catches = new ArrayList<>(catchBlocks.length);
 
 		for (CatchHandler handler : catchBlocks) {
 			TryCatchBlock tcBlock = new TryCatchBlock();
 			catches.add(tcBlock);
-			for (int i = 0; i < handler.getAddresses().length; i++) {
-				int addr = handler.getAddresses()[i];
-				ClassInfo type = ClassInfo.fromDex(parentClass.dex(), handler.getTypeIndexes()[i]);
-				tcBlock.addHandler(this, addr, type);
+			int[] handlerAddrArr = handler.getAddresses();
+			for (int i = 0; i < handlerAddrArr.length; i++) {
+				int addr = handlerAddrArr[i];
+				ClassInfo type = ClassInfo.fromDex(mth.dex(), handler.getTypeIndexes()[i]);
+				tcBlock.addHandler(mth, addr, type);
 				addrs.add(addr);
-				hc++;
+				handlersCount++;
 			}
 			int addr = handler.getCatchAllAddress();
 			if (addr >= 0) {
-				tcBlock.addHandler(this, addr, null);
+				tcBlock.addHandler(mth, addr, null);
 				addrs.add(addr);
-				hc++;
+				handlersCount++;
 			}
 		}
 
-		if (hc > 0 && hc != addrs.size()) {
+		if (handlersCount > 0 && handlersCount != addrs.size()) {
 			// resolve nested try blocks:
 			// inner block contains all handlers from outer block => remove these handlers from inner block
 			// each handler must be only in one try/catch block
 			for (TryCatchBlock ct1 : catches) {
 				for (TryCatchBlock ct2 : catches) {
 					if (ct1 != ct2 && ct2.containsAllHandlers(ct1)) {
 						for (ExceptionHandler h : ct1.getHandlers()) {
-							ct2.removeHandler(this, h);
+							ct2.removeHandler(mth, h);
 							h.setTryBlock(ct1);
 						}
 					}
@@ -309,6 +309,7 @@ private void initTryCatches(Code mthCode) {
 			for (ExceptionHandler eh : ct.getHandlers()) {
 				int addr = eh.getHandleOffset();
 				ExcHandlerAttr ehAttr = new ExcHandlerAttr(ct, eh);
+				// TODO: don't override existing attribute
 				insnByOffset[addr].addAttr(ehAttr);
 			}
 		}
@@ -335,8 +336,7 @@ private void initTryCatches(Code mthCode) {
 		}
 	}
 
-	private void initJumps() {
-		InsnNode[] insnByOffset = instructions;
+	private static void initJumps(InsnNode[] insnByOffset) {
 		for (int offset = 0; offset < insnByOffset.length; offset++) {
 			InsnNode insn = insnByOffset[offset];
 			if (insn == null) {
@@ -484,7 +484,18 @@ public ExceptionHandler addExceptionHandler(ExceptionHandler handler) {
 			exceptionHandlers = new ArrayList<>(2);
 		} else {
 			for (ExceptionHandler h : exceptionHandlers) {
-				if (h == handler || h.getHandleOffset() == handler.getHandleOffset()) {
+				if (h.equals(handler)) {
+					return h;
+				}
+				if (h.getHandleOffset() == handler.getHandleOffset()) {
+					if (h.getTryBlock() == handler.getTryBlock()) {
+						for (ClassInfo catchType : handler.getCatchTypes()) {
+							h.addCatchType(catchType);
+						}
+					} else {
+						// same handlers from different try blocks
+						// will merge later
+					}
 					return h;
 				}
 			}

jadx-core/src/main/java/jadx/core/dex/trycatch/ExcHandlerAttr.java

@@ -30,6 +30,6 @@ public ExceptionHandler getHandler() {
 	public String toString() {
 		return "ExcHandler: " + (handler.isFinally()
 				? " FINALLY"
-				: (handler.isCatchAll() ? "all" : handler.getCatchType()) + " " + handler.getArg());
+				: handler.catchTypeStr() + " " + handler.getArg());
 	}
 }

jadx-core/src/main/java/jadx/core/dex/trycatch/ExceptionHandler.java

@@ -1,18 +1,27 @@
 package jadx.core.dex.trycatch;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
+import java.util.Objects;
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.jetbrains.annotations.Nullable;
 
 import jadx.core.Consts;
 import jadx.core.dex.info.ClassInfo;
+import jadx.core.dex.instructions.args.ArgType;
 import jadx.core.dex.instructions.args.InsnArg;
 import jadx.core.dex.nodes.BlockNode;
 import jadx.core.dex.nodes.IContainer;
 import jadx.core.utils.InsnUtils;
+import jadx.core.utils.Utils;
+import jadx.core.utils.exceptions.JadxRuntimeException;
 
 public class ExceptionHandler {
 
-	private final ClassInfo catchType;
+	private final Set<ClassInfo> catchTypes = new TreeSet<>();
 	private final int handleOffset;
 
 	private BlockNode handlerBlock;
@@ -23,17 +32,57 @@ public class ExceptionHandler {
 	private TryCatchBlock tryBlock;
 	private boolean isFinally;
 
-	public ExceptionHandler(int addr, ClassInfo type) {
+	public ExceptionHandler(int addr, @Nullable ClassInfo type) {
 		this.handleOffset = addr;
-		this.catchType = type;
+		addCatchType(type);
+	}
+
+	/**
+	 * Add exception type to catch block
+	 * @param type - null for 'all' or 'Throwable' handler
+	 */
+	public void addCatchType(@Nullable ClassInfo type) {
+		if (type != null) {
+			this.catchTypes.add(type);
+		} else {
+			if (!this.catchTypes.isEmpty()) {
+				throw new JadxRuntimeException("Null type added to not empty exception handler: " + this);
+			}
+		}
+	}
+
+	public void addCatchTypes(Collection<ClassInfo> types) {
+		for (ClassInfo type : types) {
+			addCatchType(type);
+		}
 	}
 
-	public ClassInfo getCatchType() {
-		return catchType;
+	public Set<ClassInfo> getCatchTypes() {
+		return catchTypes;
+	}
+
+	public ArgType getArgType() {
+		if (isCatchAll()) {
+			return ArgType.THROWABLE;
+		}
+		Set<ClassInfo> types = getCatchTypes();
+		if (types.size() == 1) {
+			return types.iterator().next().getType();
+		} else {
+			return ArgType.THROWABLE;
+		}
 	}
 
 	public boolean isCatchAll() {
-		return catchType == null || catchType.getFullName().equals(Consts.CLASS_THROWABLE);
+		if (catchTypes.isEmpty()) {
+			return true;
+		}
+		for (ClassInfo classInfo : catchTypes) {
+			if (classInfo.getFullName().equals(Consts.CLASS_THROWABLE)) {
+				return true;
+			}
+		}
+		return false;
 	}
 
 	public int getHandleOffset() {
@@ -89,35 +138,30 @@ public void setFinally(boolean isFinally) {
 	}
 
 	@Override
-	public int hashCode() {
-		return (catchType == null ? 0 : 31 * catchType.hashCode()) + handleOffset;
-	}
-
-	@Override
-	public boolean equals(Object obj) {
-		if (this == obj) {
+	public boolean equals(Object o) {
+		if (this == o) {
 			return true;
 		}
-		if (obj == null) {
-			return false;
-		}
-		if (getClass() != obj.getClass()) {
-			return false;
-		}
-		ExceptionHandler other = (ExceptionHandler) obj;
-		if (catchType == null) {
-			if (other.catchType != null) {
-				return false;
-			}
-		} else if (!catchType.equals(other.catchType)) {
+		if (o == null || getClass() != o.getClass()) {
 			return false;
 		}
-		return handleOffset == other.handleOffset;
+		ExceptionHandler that = (ExceptionHandler) o;
+		return handleOffset == that.handleOffset &&
+				catchTypes.equals(that.catchTypes) &&
+				Objects.equals(tryBlock, that.tryBlock);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(catchTypes, handleOffset /*, tryBlock*/);
+	}
+
+	public String catchTypeStr() {
+		return catchTypes.isEmpty() ? "all" : Utils.listToString(catchTypes, " | ", ClassInfo::getShortName);
 	}
 
 	@Override
 	public String toString() {
-		return (catchType == null ? "all"
-				: catchType.getShortName()) + " -> " + InsnUtils.formatOffset(handleOffset);
+		return catchTypeStr() + " -> " + InsnUtils.formatOffset(handleOffset);
 	}
 }

jadx-core/src/main/java/jadx/core/dex/trycatch/TryCatchBlock.java

@@ -5,6 +5,8 @@
 import java.util.LinkedList;
 import java.util.List;
 
+import org.jetbrains.annotations.Nullable;
+
 import jadx.core.dex.attributes.AFlag;
 import jadx.core.dex.attributes.AType;
 import jadx.core.dex.info.ClassInfo;
@@ -40,12 +42,14 @@ public boolean containsAllHandlers(TryCatchBlock tb) {
 		return handlers.containsAll(tb.handlers);
 	}
 
-	public ExceptionHandler addHandler(MethodNode mth, int addr, ClassInfo type) {
+	public ExceptionHandler addHandler(MethodNode mth, int addr, @Nullable ClassInfo type) {
 		ExceptionHandler handler = new ExceptionHandler(addr, type);
-		handler = mth.addExceptionHandler(handler);
-		handlers.add(handler);
 		handler.setTryBlock(this);
-		return handler;
+		ExceptionHandler addedHandler = mth.addExceptionHandler(handler);
+		if (addedHandler == handler || addedHandler.getTryBlock() != this) {
+			handlers.add(addedHandler);
+		}
+		return addedHandler;
 	}
 
 	public void removeHandler(MethodNode mth, ExceptionHandler handler) {

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

@@ -438,7 +438,7 @@ private static void processMoveException(BlockNode block, InsnNode insn, Instruc
 
 		// result arg used both in this insn and exception handler,
 		RegisterArg resArg = insn.getResult();
-		ArgType type = excHandler.isCatchAll() ? ArgType.THROWABLE : excHandler.getCatchType().getType();
+		ArgType type = excHandler.getArgType();
 		String name = excHandler.isCatchAll() ? "th" : "e";
 		if (resArg.getName() == null) {
 			resArg.setName(name);

jadx-core/src/main/java/jadx/core/dex/visitors/blocksmaker/BlockExceptionHandler.java

@@ -48,7 +48,7 @@ private static void markExceptionHandlers(BlockNode block) {
 			return;
 		}
 		ExceptionHandler excHandler = handlerAttr.getHandler();
-		ArgType argType = excHandler.isCatchAll() ? ArgType.THROWABLE : excHandler.getCatchType().getType();
+		ArgType argType = excHandler.getArgType();
 		if (!block.getInstructions().isEmpty()) {
 			InsnNode me = block.getInstructions().get(0);
 			if (me.getType() == InsnType.MOVE_EXCEPTION) {