core: fix try-catch blocks processing

jadx-core/src/main/java/jadx/core/Jadx.java

@@ -68,10 +68,6 @@ public class Jadx {
 			passes.add(new ModVisitor());
 			passes.add(new EnumVisitor());
 
-			if (args.isCFGOutput()) {
-				passes.add(new DotGraphVisitor(outDir, false));
-			}
-
 			passes.add(new CodeShrinker());
 			passes.add(new RegionMakerVisitor());
 			passes.add(new IfRegionVisitor());
@@ -89,6 +85,10 @@ public class Jadx {
 			passes.add(new MethodInlineVisitor());
 			passes.add(new ClassModifier());
 			passes.add(new PrepareForCodeGen());
+
+			if (args.isCFGOutput()) {
+				passes.add(new DotGraphVisitor(outDir, false));
+			}
 		}
 		passes.add(new CodeGen(args));
 		return passes;

jadx-core/src/main/java/jadx/core/ProcessClass.java

@@ -3,7 +3,6 @@ package jadx.core;
 import jadx.core.dex.nodes.ClassNode;
 import jadx.core.dex.visitors.DepthTraversal;
 import jadx.core.dex.visitors.IDexTreeVisitor;
-import jadx.core.utils.exceptions.DecodeException;
 
 import java.util.List;
 
@@ -22,8 +21,6 @@ public final class ProcessClass {
 			for (IDexTreeVisitor visitor : passes) {
 				DepthTraversal.visit(visitor, cls);
 			}
-		} catch (DecodeException e) {
-			LOG.error("Decode exception: " + cls, e);
 		} catch (Exception e) {
 			LOG.error("Class process exception: " + cls, e);
 		} finally {

jadx-core/src/main/java/jadx/core/dex/instructions/args/RegisterArg.java

@@ -66,6 +66,13 @@ public class RegisterArg extends InsnArg implements Named {
 		return name;
 	}
 
+	public boolean isNameEquals(InsnArg arg) {
+		if (name == null || !(arg instanceof Named)) {
+			return false;
+		}
+		return name.equals(((Named) arg).getName());
+	}
+
 	public void setName(String newName) {
 		this.name = newName;
 	}

jadx-core/src/main/java/jadx/core/dex/instructions/args/SSAVar.java

@@ -47,6 +47,10 @@ public class SSAVar {
 		return useList;
 	}
 
+	public int getUseCount() {
+		return useList.size();
+	}
+
 	public void use(RegisterArg arg) {
 		mergeName(arg);
 		if (arg.getSVar() != null) {
@@ -81,7 +85,7 @@ public class SSAVar {
 		if (!isUsedInPhi()) {
 			return useList.size();
 		}
-		return useList.size() + usedInPhi.getResult().getSVar().getUseList().size();
+		return useList.size() + usedInPhi.getResult().getSVar().getUseCount();
 	}
 
 	public ArgType getType() {

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

@@ -205,7 +205,7 @@ public class ClassNode extends LineAttrNode implements ILoadable {
 	}
 
 	@Override
-	public void load() throws DecodeException {
+	public void load() {
 		for (MethodNode mth : getMethods()) {
 			try {
 				mth.load();

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

@@ -446,8 +446,12 @@ public class MethodNode extends LineAttrNode implements ILoadable {
 		return handler;
 	}
 
-	public List<ExceptionHandler> getExceptionHandlers() {
-		return Collections.unmodifiableList(exceptionHandlers);
+	public Iterable<ExceptionHandler> getExceptionHandlers() {
+		return exceptionHandlers;
+	}
+
+	public boolean isNoExceptionHandlers() {
+		return exceptionHandlers.isEmpty();
 	}
 
 	/**

jadx-core/src/main/java/jadx/core/dex/regions/LoopRegion.java

@@ -79,7 +79,7 @@ public final class LoopRegion extends AbstractRegion {
 				return false;
 			} else {
 				RegisterArg res = insn.getResult();
-				if (res.getSVar().getUseList().size() > 1) {
+				if (res.getSVar().getUseCount() > 1) {
 					return false;
 				}
 				boolean found = false;

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

@@ -99,11 +99,10 @@ public class ClassModifier extends AbstractVisitor {
 		mth.removeFirstArgument();
 		InstructionRemover.remove(mth, block, insn);
 		// other arg usage -> wrap with IGET insn
-		List<RegisterArg> useList = arg.getSVar().getUseList();
-		if (useList.size() > 0) {
+		if (arg.getSVar().getUseCount() != 0) {
 			InsnNode iget = new IndexInsnNode(InsnType.IGET, fieldInfo, 1);
 			iget.addArg(insn.getArg(1));
-			for (InsnArg insnArg : useList) {
+			for (InsnArg insnArg : arg.getSVar().getUseList()) {
 				insnArg.wrapInstruction(iget);
 			}
 		}

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

@@ -229,7 +229,7 @@ public class ModVisitor extends AbstractVisitor {
 		if (blockInsns.size() > 0) {
 			InsnNode insn = blockInsns.get(0);
 			if (insn.getType() == InsnType.MOVE_EXCEPTION
-					&& insn.getResult().getSVar().getUseList().isEmpty()) {
+					&& insn.getResult().getSVar().getUseCount() == 0) {
 				InstructionRemover.remove(mth, block, 0);
 			}
 		}
@@ -257,7 +257,7 @@ public class ModVisitor extends AbstractVisitor {
 	 * In argument not used in other instructions then remove assign instruction.
 	 */
 	private static void removeInsnForArg(InstructionRemover remover, RegisterArg arg) {
-		if (arg.getSVar().getUseList().isEmpty()
+		if (arg.getSVar().getUseCount() == 0
 				&& arg.getAssignInsn() != null) {
 			remover.add(arg.getAssignInsn());
 		}

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

@@ -54,6 +54,16 @@ public class PrepareForCodeGen extends AbstractVisitor {
 						it.remove();
 					}
 					break;
+
+				case MOVE:
+					// remove redundant moves:
+					//   unused result and same args names (a = a;)
+					RegisterArg result = insn.getResult();
+					if (result.getSVar().getUseCount() == 0
+							&& result.isNameEquals(insn.getArg(0))) {
+						it.remove();
+					}
+					break;
 			}
 		}
 	}

jadx-core/src/main/java/jadx/core/dex/visitors/regions/ProcessTryCatchRegions.java

@@ -40,7 +40,7 @@ public class ProcessTryCatchRegions extends AbstractRegionVisitor {
 	private final Map<BlockNode, TryCatchBlock> tryBlocksMap = new HashMap<BlockNode, TryCatchBlock>(2);
 
 	public ProcessTryCatchRegions(MethodNode mth) {
-		if (mth.isNoCode() || mth.getExceptionHandlers().isEmpty()) {
+		if (mth.isNoCode() || mth.isNoExceptionHandlers()) {
 			return;
 		}
 
@@ -84,7 +84,7 @@ public class ProcessTryCatchRegions extends AbstractRegionVisitor {
 
 			TryCatchBlock prevTB = tryBlocksMap.put(domBlock, tb);
 			if (prevTB != null) {
-				LOG.info("!!! TODO merge try blocks in " + mth);
+				LOG.info("!!! TODO: merge try blocks in " + mth);
 			}
 		}
 
@@ -134,7 +134,7 @@ public class ProcessTryCatchRegions extends AbstractRegionVisitor {
 				}
 			}
 		}
-		if (newRegion.getSubBlocks().size() != 0) {
+		if (!newRegion.getSubBlocks().isEmpty()) {
 			if (DEBUG) {
 				LOG.debug("ProcessTryCatchRegions mark: {}", newRegion);
 			}

jadx-core/src/main/java/jadx/core/dex/visitors/regions/RegionMaker.java

@@ -685,11 +685,6 @@ public class RegionMaker {
 			LOG.debug(ErrorsCounter.formatErrorMsg(mth, "No exception handler block: " + handler));
 			return;
 		}
-
-		BlockNode out = BlockUtils.traverseWhileDominates(start, start);
-		if (out != null) {
-			stack.addExit(out);
-		}
 		// TODO extract finally part which exists in all handlers from same try block
 		// TODO add blocks common for several handlers to some region
 		handler.setHandlerRegion(makeRegion(start, stack));

jadx-core/src/main/java/jadx/core/dex/visitors/regions/RegionMakerVisitor.java

@@ -34,7 +34,7 @@ public class RegionMakerVisitor extends AbstractVisitor {
 		// fill region structure
 		mth.setRegion(rm.makeRegion(mth.getEnterBlock(), state));
 
-		if (!mth.getExceptionHandlers().isEmpty()) {
+		if (!mth.isNoExceptionHandlers()) {
 			state = new RegionStack(mth);
 			for (ExceptionHandler handler : mth.getExceptionHandlers()) {
 				rm.processExcHandler(handler, state);
@@ -46,8 +46,9 @@ public class RegionMakerVisitor extends AbstractVisitor {
 
 	private static void postProcessRegions(MethodNode mth) {
 		// make try-catch regions
-		DepthRegionTraversal.traverse(mth, new ProcessTryCatchRegions(mth));
-
+		if (!mth.isNoExceptionHandlers()) {
+			DepthRegionTraversal.traverse(mth, new ProcessTryCatchRegions(mth));
+		}
 		// merge conditions in loops
 		if (mth.getLoopsCount() != 0) {
 			DepthRegionTraversal.traverseAll(mth, new AbstractRegionVisitor() {

jadx-core/src/main/java/jadx/core/dex/visitors/ssa/SSATransform.java

@@ -146,7 +146,7 @@ public class SSATransform extends AbstractVisitor {
 		List<PhiInsn> insnToRemove = new ArrayList<PhiInsn>();
 		for (SSAVar var : mth.getSVars()) {
 			// phi result not used
-			if (var.getUseList().isEmpty()) {
+			if (var.getUseCount() == 0) {
 				InsnNode assignInsn = var.getAssign().getParentInsn();
 				if (assignInsn != null && assignInsn.getType() == InsnType.PHI) {
 					insnToRemove.add((PhiInsn) assignInsn);

jadx-core/src/main/java/jadx/core/utils/BlockUtils.java

@@ -229,14 +229,14 @@ public class BlockUtils {
 	}
 
 	/**
-	 * Search for first node which not dominated by block, starting from child
+	 * Search for first node which not dominated by dom, starting from start
 	 */
-	public static BlockNode traverseWhileDominates(BlockNode block, BlockNode child) {
-		for (BlockNode node : child.getCleanSuccessors()) {
-			if (!node.isDominator(block)) {
+	public static BlockNode traverseWhileDominates(BlockNode dom, BlockNode start) {
+		for (BlockNode node : start.getCleanSuccessors()) {
+			if (!node.isDominator(dom)) {
 				return node;
 			} else {
-				BlockNode out = traverseWhileDominates(block, node);
+				BlockNode out = traverseWhileDominates(dom, node);
 				if (out != null) {
 					return out;
 				}

jadx-core/src/main/java/jadx/core/utils/InstructionRemover.java

@@ -59,7 +59,7 @@ public class InstructionRemover {
 	public static void unbindInsn(MethodNode mth, InsnNode insn) {
 		RegisterArg r = insn.getResult();
 		if (r != null && r.getSVar() != null) {
-			if (Consts.DEBUG && !r.getSVar().getUseList().isEmpty()) {
+			if (Consts.DEBUG && r.getSVar().getUseCount() != 0) {
 				LOG.debug("Unbind insn with result: {}", insn);
 			}
 			mth.removeSVar(r.getSVar());

jadx-core/src/test/java/jadx/api/InternalJadxTest.java

 package jadx.api;
 
 import jadx.core.Jadx;
+import jadx.core.dex.attributes.AFlag;
+import jadx.core.dex.attributes.AType;
 import jadx.core.dex.nodes.ClassNode;
 import jadx.core.dex.nodes.MethodNode;
 import jadx.core.dex.visitors.DepthTraversal;
@@ -23,6 +25,7 @@ import static org.hamcrest.CoreMatchers.not;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 public abstract class InternalJadxTest extends TestUtils {
@@ -33,48 +36,45 @@ public abstract class InternalJadxTest extends TestUtils {
 	protected String outDir = "test-out-tmp";
 
 	public ClassNode getClassNode(Class<?> clazz) {
+		Decompiler d = new Decompiler();
 		try {
-			File temp = getJarForClass(clazz);
-			Decompiler d = new Decompiler();
-			try {
-				d.loadFile(temp);
-			} catch (Exception e) {
-				fail(e.getMessage());
-			}
-			List<ClassNode> classes = d.getRoot().getClasses(false);
-			String clsName = clazz.getName();
-			ClassNode cls = null;
-			for (ClassNode aClass : classes) {
-				if (aClass.getFullName().equals(clsName)) {
-					cls = aClass;
-				}
-			}
-			assertNotNull("Class not found: " + clsName, cls);
+			d.loadFile(getJarForClass(clazz));
+		} catch (Exception e) {
+			fail(e.getMessage());
+		}
+		String clsName = clazz.getName();
+		ClassNode cls = d.getRoot().searchClassByName(clsName);
+		assertNotNull("Class not found: " + clsName, cls);
+		assertEquals(cls.getFullName(), clazz.getName());
+
+		cls.load();
+		for (IDexTreeVisitor visitor : getPasses()) {
+			DepthTraversal.visit(visitor, cls);
+		}
+		// don't unload class
 
-			assertEquals(cls.getFullName(), clazz.getName());
+		assertTrue("Inconsistent cls: " + cls,
+				!cls.contains(AFlag.INCONSISTENT_CODE) && !cls.contains(AType.JADX_ERROR));
+		for (MethodNode mthNode : cls.getMethods()) {
+			assertTrue("Inconsistent method: " + mthNode,
+					!mthNode.contains(AFlag.INCONSISTENT_CODE) && !mthNode.contains(AType.JADX_ERROR));
+		}
+		assertThat(cls.getCode().toString(), not(containsString("inconsistent")));
+		return cls;
+	}
 
-			cls.load();
-			List<IDexTreeVisitor> passes = Jadx.getPassesList(new DefaultJadxArgs() {
-				@Override
-				public boolean isCFGOutput() {
-					return outputCFG;
-				}
+	protected List<IDexTreeVisitor> getPasses() {
+		return Jadx.getPassesList(new DefaultJadxArgs() {
+			@Override
+			public boolean isCFGOutput() {
+				return outputCFG;
+			}
 
-				@Override
-				public boolean isRawCFGOutput() {
-					return outputCFG;
-				}
-			}, new File(outDir));
-			for (IDexTreeVisitor visitor : passes) {
-				DepthTraversal.visit(visitor, cls);
+			@Override
+			public boolean isRawCFGOutput() {
+				return outputCFG;
 			}
-			assertThat(cls.getCode().toString(), not(containsString("inconsistent")));
-			return cls;
-		} catch (Exception e) {
-			e.printStackTrace();
-			fail(e.getMessage());
-			return null;
-		}
+		}, new File(outDir));
 	}
 
 	protected MethodNode getMethod(ClassNode cls, String method) {

jadx-core/src/test/java/jadx/tests/internal/TestVariablesDefinitions.java

@@ -4,7 +4,6 @@ import jadx.api.InternalJadxTest;
 import jadx.core.dex.nodes.ClassNode;
 import jadx.core.dex.visitors.DepthTraversal;
 import jadx.core.dex.visitors.IDexTreeVisitor;
-import jadx.core.utils.exceptions.DecodeException;
 
 import java.util.Iterator;
 import java.util.List;
@@ -30,7 +29,7 @@ public class TestVariablesDefinitions extends InternalJadxTest {
 				while (iterator.hasNext()) {
 					DepthTraversal.visit(iterator.next(), cls);
 				}
-			} catch (DecodeException e) {
+			} catch (Exception e) {
 				LOG.error("Decode exception: " + cls, e);
 			}
 		}

jadx-core/src/test/java/jadx/tests/internal/trycatch/TestTryCatch4.java

+package jadx.tests.internal.trycatch;
+
+import jadx.api.InternalJadxTest;
+import jadx.core.dex.nodes.ClassNode;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.not;
+import static org.junit.Assert.assertThat;
+
+public class TestTryCatch4 extends InternalJadxTest {
+
+	public static class TestCls {
+		private Object test(Object obj) {
+			FileOutputStream output = null;
+			try {
+				output = new FileOutputStream(new File("f"));
+				return new Object();
+			} catch (FileNotFoundException e) {
+				System.out.println("Exception");
+				return null;
+			}
+		}
+	}
+
+	@Test
+	public void test() {
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+		System.out.println(code);
+
+		assertThat(code, containsString("try {"));
+		assertThat(code, containsString("output = new FileOutputStream(new File(\"f\"));"));
+		assertThat(code, containsString("return new Object();"));
+		assertThat(code, containsString("} catch (FileNotFoundException e) {"));
+		assertThat(code, containsString("System.out.println(\"Exception\");"));
+		assertThat(code, containsString("return null;"));
+		assertThat(code, not(containsString("output = output;")));
+	}
+}