fix: support all-catch in multi-catch (#1510)

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

@@ -14,9 +14,9 @@ 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.dex.nodes.MethodNode;
 import jadx.core.utils.InsnUtils;
 import jadx.core.utils.Utils;
-import jadx.core.utils.exceptions.JadxRuntimeException;
 
 public class ExceptionHandler {
 
@@ -33,9 +33,14 @@ public class ExceptionHandler {
 
 	private boolean removed = false;
 
-	public ExceptionHandler(int addr, @Nullable ClassInfo type) {
+	public static ExceptionHandler build(MethodNode mth, int addr, @Nullable ClassInfo type) {
+		ExceptionHandler eh = new ExceptionHandler(addr);
+		eh.addCatchType(mth, type);
+		return eh;
+	}
+
+	private ExceptionHandler(int addr) {
 		this.handlerOffset = addr;
-		addCatchType(type);
 	}
 
 	/**
@@ -43,7 +48,7 @@ public class ExceptionHandler {
 	 *
 	 * @param type - null for 'all' or 'Throwable' handler
 	 */
-	public boolean addCatchType(@Nullable ClassInfo type) {
+	public boolean addCatchType(MethodNode mth, @Nullable ClassInfo type) {
 		if (type != null) {
 			if (catchTypes.contains(type)) {
 				return false;
@@ -51,14 +56,16 @@ public class ExceptionHandler {
 			return catchTypes.add(type);
 		}
 		if (!this.catchTypes.isEmpty()) {
-			throw new JadxRuntimeException("Null type added to not empty exception handler: " + this);
+			mth.addDebugComment("Throwable added to exception handler: '" + catchTypeStr() + "', keep only Throwable");
+			catchTypes.clear();
+			return true;
 		}
 		return false;
 	}
 
-	public void addCatchTypes(Collection<ClassInfo> types) {
+	public void addCatchTypes(MethodNode mth, Collection<ClassInfo> types) {
 		for (ClassInfo type : types) {
-			addCatchType(type);
+			addCatchType(mth, type);
 		}
 	}
 

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

@@ -133,7 +133,7 @@ public class AttachTryCatchVisitor extends AbstractVisitor {
 			ExcHandlerAttr excHandlerAttr = insn.get(AType.EXC_HANDLER);
 			if (excHandlerAttr != null) {
 				ExceptionHandler handler = excHandlerAttr.getHandler();
-				if (handler.addCatchType(type)) {
+				if (handler.addCatchType(mth, type)) {
 					// exist handler updated (assume from same try block) - don't add again
 					return null;
 				}
@@ -143,7 +143,7 @@ public class AttachTryCatchVisitor extends AbstractVisitor {
 		} else {
 			insn = insertNOP(insnByOffset, handlerOffset);
 		}
-		ExceptionHandler handler = new ExceptionHandler(handlerOffset, type);
+		ExceptionHandler handler = ExceptionHandler.build(mth, handlerOffset, type);
 		mth.addExceptionHandler(handler);
 		insn.addAttr(new ExcHandlerAttr(handler));
 		return handler;

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

@@ -549,7 +549,7 @@ public class BlockExceptionHandler {
 			if (handler == resultHandler) {
 				return false;
 			}
-			resultHandler.addCatchTypes(handler.getCatchTypes());
+			resultHandler.addCatchTypes(mth, handler.getCatchTypes());
 			handler.markForRemove();
 			return true;
 		});

jadx-core/src/test/java/jadx/tests/integration/trycatch/TestTryCatchMultiException.java

@@ -25,8 +25,6 @@ public class TestTryCatchMultiException extends IntegrationTest {
 
 	@Test
 	public void test() {
-		// printDisassemble();
-		// setFallback();
 		noDebugInfo();
 		ClassNode cls = getClassNode(TestCls.class);
 		String code = cls.getCode().toString();

jadx-core/src/test/java/jadx/tests/integration/trycatch/TestTryCatchMultiException2.java

+package jadx.tests.integration.trycatch;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.tests.api.SmaliTest;
+
+import static jadx.tests.api.utils.assertj.JadxAssertions.assertThat;
+
+@SuppressWarnings("CommentedOutCode")
+public class TestTryCatchMultiException2 extends SmaliTest {
+
+	// @formatter:off
+	/*
+    public static boolean test() {
+        try {
+            Class<?> cls = Class.forName("c");
+            return ((Boolean) cls.getMethod("b", new Class[0]).invoke(cls, new Object[0])).booleanValue();
+        } catch (ClassNotFoundException | NoSuchMethodException | Exception | Throwable unused) {
+        	// java compiler don't allow shadow subclasses in multi-catch
+        	// in this case leave only Throwable
+            return false;
+        }
+    }
+	*/
+	// @formatter:on
+
+	@Test
+	public void test() {
+		assertThat(getClassNodeFromSmali())
+				.code()
+				.containsOne("} catch (Throwable unused) {");
+	}
+}

jadx-core/src/test/smali/trycatch/TestTryCatchMultiException2.smali

+.class public Ltrycatch/TestTryCatchMultiException2;
+.super Ljava/lang/Object;
+
+
+.method public static test()Z
+    .registers 5
+
+    :try_start_b
+    const-string v0, "c"
+    invoke-static {v0}, Ljava/lang/Class;->forName(Ljava/lang/String;)Ljava/lang/Class;
+    move-result-object v1
+
+    const/4 v0, 0x0
+    const-string v2, "b"
+    new-array v3, v0, [Ljava/lang/Class;
+    invoke-virtual {v1, v2, v3}, Ljava/lang/Class;->getMethod(Ljava/lang/String;[Ljava/lang/Class;)Ljava/lang/reflect/Method;
+    move-result-object v2
+
+    new-array v3, v0, [Ljava/lang/Object;
+    invoke-virtual {v2, v1, v3}, Ljava/lang/reflect/Method;->invoke(Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;
+    move-result-object v1
+
+    check-cast v1, Ljava/lang/Boolean;
+    invoke-virtual {v1}, Ljava/lang/Boolean;->booleanValue()Z
+
+    move-result v1
+    :try_end_2f
+    .catch Ljava/lang/ClassNotFoundException; {:try_start_b .. :try_end_2f} :catch_30
+    .catch Ljava/lang/NoSuchMethodException; {:try_start_b .. :try_end_2f} :catch_30
+    .catch Ljava/lang/Exception; {:try_start_b .. :try_end_2f} :catch_30
+    .catchall {:try_start_b .. :try_end_2f} :catchall_30
+
+    return v1
+
+    :catch_30
+    :catchall_30
+    return v0
+.end method