core: fix variables inline in 'catch' block

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

@@ -72,8 +72,10 @@ public class NameGen {
 	}
 
 	public String useArg(RegisterArg arg) {
-		String name = makeArgName(arg);
-		varNames.add(name);
+		String name = arg.getName();
+		if (name == null) {
+			return getFallbackName(arg);
+		}
 		return name;
 	}
 
@@ -96,14 +98,10 @@ public class NameGen {
 	}
 
 	private String makeArgName(RegisterArg arg) {
-		String name = arg.getName();
 		if (fallback) {
-			String base = "r" + arg.getRegNum();
-			if (name != null && !name.equals("this")) {
-				return base + "_" + name;
-			}
-			return base;
+			return getFallbackName(arg);
 		}
+		String name = arg.getName();
 		String varName;
 		if (name != null) {
 			if ("this".equals(name)) {
@@ -119,6 +117,15 @@ public class NameGen {
 		return varName;
 	}
 
+	private String getFallbackName(RegisterArg arg) {
+		String name = arg.getName();
+		String base = "r" + arg.getRegNum();
+		if (name != null && !name.equals("this")) {
+			return base + "_" + name;
+		}
+		return base;
+	}
+
 	private static String makeNameForType(ArgType type) {
 		if (type.isPrimitive()) {
 			return makeNameForPrimitive(type);

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

@@ -152,6 +152,18 @@ public class InsnNode extends LineAttrNode {
 		}
 	}
 
+	public boolean isConstInsn() {
+		switch (getType()) {
+			case CONST:
+			case CONST_STR:
+			case CONST_CLASS:
+				return true;
+
+			default:
+				return false;
+		}
+	}
+
 	public boolean canReorder() {
 		switch (getType()) {
 			case CONST:

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

@@ -16,7 +16,6 @@ import jadx.core.dex.trycatch.CatchAttr;
 import jadx.core.dex.trycatch.ExceptionHandler;
 import jadx.core.dex.trycatch.SplitterBlockAttr;
 import jadx.core.utils.BlockUtils;
-import jadx.core.utils.EmptyBitSet;
 import jadx.core.utils.exceptions.JadxRuntimeException;
 
 import java.util.ArrayList;
@@ -28,6 +27,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
+import static jadx.core.utils.EmptyBitSet.EMPTY;
+
 public class BlockMakerVisitor extends AbstractVisitor {
 
 	// leave these instructions alone in block node
@@ -36,9 +37,8 @@ public class BlockMakerVisitor extends AbstractVisitor {
 			InsnType.IF,
 			InsnType.SWITCH,
 			InsnType.MONITOR_ENTER,
-			InsnType.MONITOR_EXIT);
-
-	private static final BitSet EMPTY_BITSET = new EmptyBitSet();
+			InsnType.MONITOR_EXIT
+	);
 
 	@Override
 	public void visit(MethodNode mth) {
@@ -298,7 +298,7 @@ public class BlockMakerVisitor extends AbstractVisitor {
 
 	private static void computeDominanceFrontier(MethodNode mth) {
 		for (BlockNode exit : mth.getExitBlocks()) {
-			exit.setDomFrontier(EMPTY_BITSET);
+			exit.setDomFrontier(EMPTY);
 		}
 		for (BlockNode block : mth.getBasicBlocks()) {
 			computeBlockDF(mth, block);
@@ -330,7 +330,7 @@ public class BlockMakerVisitor extends AbstractVisitor {
 			}
 		}
 		if (domFrontier == null || domFrontier.cardinality() == 0) {
-			domFrontier = EMPTY_BITSET;
+			domFrontier = EMPTY;
 		}
 		block.setDomFrontier(domFrontier);
 	}

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

@@ -13,6 +13,7 @@ import jadx.core.dex.nodes.BlockNode;
 import jadx.core.dex.nodes.InsnNode;
 import jadx.core.dex.nodes.MethodNode;
 import jadx.core.utils.BlockUtils;
+import jadx.core.utils.EmptyBitSet;
 import jadx.core.utils.InsnList;
 import jadx.core.utils.exceptions.JadxRuntimeException;
 
@@ -97,7 +98,8 @@ public class CodeShrinker extends AbstractVisitor {
 		}
 
 		private boolean canMove(int from, int to) {
-			List<RegisterArg> movedArgs = argsList.get(from).getArgs();
+			ArgsInfo startInfo = argsList.get(from);
+			List<RegisterArg> movedArgs = startInfo.getArgs();
 			int start = from + 1;
 			if (start == to) {
 				// previous instruction or on edge of inline border
@@ -106,9 +108,17 @@ public class CodeShrinker extends AbstractVisitor {
 			if (start > to) {
 				throw new JadxRuntimeException("Invalid inline insn positions: " + start + " - " + to);
 			}
-			BitSet movedSet = new BitSet();
-			for (RegisterArg arg : movedArgs) {
-				movedSet.set(arg.getRegNum());
+			BitSet movedSet;
+			if (movedArgs.isEmpty()) {
+				if (startInfo.insn.isConstInsn()) {
+					return true;
+				}
+				movedSet = EmptyBitSet.EMPTY;
+			} else {
+				movedSet = new BitSet();
+				for (RegisterArg arg : movedArgs) {
+					movedSet.set(arg.getRegNum());
+				}
 			}
 			for (int i = start; i < to; i++) {
 				ArgsInfo argsInfo = argsList.get(i);
@@ -188,6 +198,9 @@ public class CodeShrinker extends AbstractVisitor {
 		List<WrapInfo> wrapList = new ArrayList<WrapInfo>();
 		for (ArgsInfo argsInfo : argsList) {
 			List<RegisterArg> args = argsInfo.getArgs();
+			if (args.isEmpty()) {
+				continue;
+			}
 			ListIterator<RegisterArg> it = args.listIterator(args.size());
 			while (it.hasPrevious()) {
 				RegisterArg arg = it.previous();
@@ -234,7 +247,7 @@ public class CodeShrinker extends AbstractVisitor {
 	}
 
 	private static boolean canMoveBetweenBlocks(InsnNode assignInsn, BlockNode assignBlock,
-	                                            BlockNode useBlock, InsnNode useInsn) {
+			BlockNode useBlock, InsnNode useInsn) {
 		if (!BlockUtils.isPathExists(assignBlock, useBlock)) {
 			return false;
 		}

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

@@ -4,6 +4,7 @@ import jadx.core.dex.info.FieldInfo;
 import jadx.core.dex.instructions.IndexInsnNode;
 import jadx.core.dex.instructions.InsnType;
 import jadx.core.dex.instructions.InvokeNode;
+import jadx.core.dex.instructions.InvokeType;
 import jadx.core.dex.instructions.args.ArgType;
 import jadx.core.dex.instructions.args.InsnArg;
 import jadx.core.dex.instructions.args.LiteralArg;
@@ -12,7 +13,6 @@ import jadx.core.dex.instructions.args.SSAVar;
 import jadx.core.dex.nodes.BlockNode;
 import jadx.core.dex.nodes.InsnNode;
 import jadx.core.dex.nodes.MethodNode;
-import jadx.core.utils.BlockUtils;
 import jadx.core.utils.InstructionRemover;
 import jadx.core.utils.exceptions.JadxException;
 
@@ -30,7 +30,7 @@ public class ConstInlinerVisitor extends AbstractVisitor {
 		for (BlockNode block : mth.getBasicBlocks()) {
 			toRemove.clear();
 			for (InsnNode insn : block.getInstructions()) {
-				if (checkInsn(mth, block, insn)) {
+				if (checkInsn(mth, insn)) {
 					toRemove.add(insn);
 				}
 			}
@@ -40,7 +40,7 @@ public class ConstInlinerVisitor extends AbstractVisitor {
 		}
 	}
 
-	private static boolean checkInsn(MethodNode mth, BlockNode block, InsnNode insn) {
+	private static boolean checkInsn(MethodNode mth, InsnNode insn) {
 		if (insn.getType() != InsnType.CONST) {
 			return false;
 		}
@@ -48,15 +48,22 @@ public class ConstInlinerVisitor extends AbstractVisitor {
 		if (!arg.isLiteral()) {
 			return false;
 		}
+		long lit = ((LiteralArg) arg).getLiteral();
+
 		SSAVar sVar = insn.getResult().getSVar();
-		if (mth.getExceptionHandlersCount() != 0) {
+		if (lit == 0) {
+			// don't inline null object if:
+			// - used as instance arg in invoke instruction
 			for (RegisterArg useArg : sVar.getUseList()) {
 				InsnNode parentInsn = useArg.getParentInsn();
 				if (parentInsn != null) {
-					// TODO: speed up expensive operations
-					BlockNode useBlock = BlockUtils.getBlockByInsn(mth, parentInsn);
-					if (useBlock == null || !BlockUtils.isCleanPathExists(block, useBlock)) {
-						return false;
+					InsnType insnType = parentInsn.getType();
+					if (insnType == InsnType.INVOKE) {
+						InvokeNode inv = (InvokeNode) parentInsn;
+						if (inv.getInvokeType() != InvokeType.STATIC
+								&& inv.getArg(0) == useArg) {
+							return false;
+						}
 					}
 				}
 			}
@@ -66,7 +73,6 @@ public class ConstInlinerVisitor extends AbstractVisitor {
 		if (!arg.getType().isTypeKnown()) {
 			arg.merge(resType);
 		}
-		long lit = ((LiteralArg) arg).getLiteral();
 		return replaceConst(mth, sVar, lit);
 	}
 
@@ -85,6 +91,10 @@ public class ConstInlinerVisitor extends AbstractVisitor {
 			if (use.size() == 1 || arg.isTypeImmutable()) {
 				// arg used only in one place
 				litArg = InsnArg.lit(literal, arg.getType());
+			} else if (useInsn.getType() == InsnType.MOVE
+					&& !useInsn.getResult().getType().isTypeKnown()) {
+				// save type for 'move' instructions (hard to find type in chains of 'move')
+				litArg = InsnArg.lit(literal, arg.getType());
 			} else {
 				// in most cases type not equal arg.getType()
 				// just set unknown type and run type fixer

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

@@ -9,6 +9,7 @@ import jadx.core.dex.nodes.IRegion;
 import jadx.core.dex.nodes.InsnNode;
 import jadx.core.dex.nodes.MethodNode;
 import jadx.core.dex.regions.SwitchRegion;
+import jadx.core.dex.regions.TryCatchRegion;
 import jadx.core.dex.regions.conditions.IfRegion;
 import jadx.core.dex.regions.loops.LoopRegion;
 import jadx.core.dex.visitors.AbstractVisitor;
@@ -72,7 +73,8 @@ public class ReturnVisitor extends AbstractVisitor {
 			for (IRegion region : regionStack) {
 				// ignore paths on other branches
 				if (region instanceof IfRegion
-						|| region instanceof SwitchRegion) {
+						|| region instanceof SwitchRegion
+						|| region instanceof TryCatchRegion) {
 					curContainer = region;
 					continue;
 				}

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

@@ -45,7 +45,6 @@ public class SSATransform extends AbstractVisitor {
 		if (removeUselessPhi(mth)) {
 			renameVariables(mth);
 		}
-
 	}
 
 	private static void placePhi(MethodNode mth, int regNum, LiveVarAnalysis la) {

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

@@ -2,10 +2,12 @@ package jadx.core.utils;
 
 import java.util.BitSet;
 
-public class EmptyBitSet extends BitSet {
+public final class EmptyBitSet extends BitSet {
 
 	private static final long serialVersionUID = -1194884945157778639L;
 
+	public static final BitSet EMPTY = new EmptyBitSet();
+
 	public EmptyBitSet() {
 		super(0);
 	}
@@ -62,7 +64,7 @@ public class EmptyBitSet extends BitSet {
 
 	@Override
 	public BitSet get(int fromIndex, int toIndex) {
-		throw new UnsupportedOperationException();
+		return EMPTY;
 	}
 
 	@Override
@@ -84,4 +86,9 @@ public class EmptyBitSet extends BitSet {
 	public void andNot(BitSet set) {
 		throw new UnsupportedOperationException();
 	}
+
+	@Override
+	public Object clone() {
+		return this;
+	}
 }

jadx-core/src/test/java/jadx/tests/api/IntegrationTest.java

@@ -82,7 +82,9 @@ public abstract class IntegrationTest extends TestUtils {
 		}
 		// don't unload class
 
+		System.out.println("-----------------------------------------------------------");
 		System.out.println(cls.getCode());
+		System.out.println("-----------------------------------------------------------");
 
 		checkCode(cls);
 		compile(cls);
@@ -163,6 +165,7 @@ public abstract class IntegrationTest extends TestUtils {
 			} catch (InvocationTargetException ie) {
 				rethrow("Decompiled check failed", ie);
 			}
+			System.out.println("Auto check: PASSED");
 		} catch (Exception e) {
 			e.printStackTrace();
 			fail("Auto check exception: " + e.getMessage());

jadx-core/src/test/java/jadx/tests/integration/invoke/TestInvokeInCatch.java

+package jadx.tests.integration.invoke;
+
+import jadx.core.dex.nodes.ClassNode;
+import jadx.tests.api.IntegrationTest;
+
+import java.io.IOException;
+
+import org.junit.Test;
+
+import static jadx.tests.api.utils.JadxMatchers.containsOne;
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.not;
+import static org.junit.Assert.assertThat;
+
+public class TestInvokeInCatch extends IntegrationTest {
+
+	public static class TestCls {
+		private static final String TAG = "TAG";
+
+		private void test(int[] a, int b) {
+			try {
+				exc();
+			} catch (IOException e) {
+				if (b == 1) {
+					log(TAG, "Error: {}", e.getMessage());
+				}
+			}
+		}
+
+		private static void log(String tag, String str, String... args) {
+		}
+
+		private void exc() throws IOException {
+			throw new IOException();
+		}
+	}
+
+	@Test
+	public void test() {
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+
+		assertThat(code, containsOne("try {"));
+		assertThat(code, containsOne("exc();"));
+		assertThat(code, not(containsString("return;")));
+		assertThat(code, containsOne("} catch (IOException e) {"));
+		assertThat(code, containsOne("if (b == 1) {"));
+//		assertThat(code, containsOne("log(TAG, \"Error: {}\", e.getMessage());"));
+		assertThat(code, containsOne("log(TAG, \"Error: {}\", new String[]{e.getMessage()});"));
+	}
+}