fix: forbid to change types for methods arguments

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

@@ -6,7 +6,7 @@ import java.util.List;
 
 public class CodeVar {
 	private String name;
-	private ArgType type;
+	private ArgType type; // nullable before type inference, set only for immutable types
 	private List<SSAVar> ssaVars = new ArrayList<>(3);
 
 	private boolean isFinal;

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

@@ -139,6 +139,9 @@ public class SSAVar extends AttrNode {
 
 	public void setCodeVar(@NotNull CodeVar codeVar) {
 		this.codeVar = codeVar;
+		if (codeVar.getType() != null && !typeInfo.getType().equals(codeVar.getType())) {
+			throw new JadxRuntimeException("Unmached types for SSA and Code variables: " + this + " and " + codeVar);
+		}
 		codeVar.addSsaVar(this);
 	}
 

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

 package jadx.core.dex.visitors;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.List;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import jadx.core.dex.attributes.AFlag;
 import jadx.core.dex.instructions.PhiInsn;
+import jadx.core.dex.instructions.args.ArgType;
 import jadx.core.dex.instructions.args.CodeVar;
 import jadx.core.dex.instructions.args.RegisterArg;
 import jadx.core.dex.instructions.args.SSAVar;
 import jadx.core.dex.nodes.MethodNode;
 import jadx.core.dex.visitors.ssa.SSATransform;
 import jadx.core.utils.exceptions.JadxException;
+import jadx.core.utils.exceptions.JadxRuntimeException;
 
 @JadxVisitor(
 		name = "InitCodeVariables",
@@ -41,7 +45,6 @@ public class InitCodeVariables extends AbstractVisitor {
 			return;
 		}
 		CodeVar codeVar = new CodeVar();
-		codeVar.setType(ssaVar.getTypeInfo().getType());
 		RegisterArg assignArg = ssaVar.getAssign();
 		if (assignArg.contains(AFlag.THIS)) {
 			codeVar.setName(RegisterArg.THIS_ARG_NAME);
@@ -55,17 +58,36 @@ public class InitCodeVariables extends AbstractVisitor {
 	}
 
 	private static void setCodeVar(SSAVar ssaVar, CodeVar codeVar) {
-		ssaVar.setCodeVar(codeVar);
 		PhiInsn usedInPhi = ssaVar.getUsedInPhi();
 		if (usedInPhi != null) {
-			Set<SSAVar> vars = new HashSet<>();
+			Set<SSAVar> vars = new LinkedHashSet<>();
+			vars.add(ssaVar);
 			collectConnectedVars(usedInPhi, vars);
+			setCodeVarType(codeVar, vars);
 			vars.forEach(var -> {
 				if (var.isCodeVarSet()) {
 					codeVar.mergeFlagsFrom(var.getCodeVar());
 				}
 				var.setCodeVar(codeVar);
 			});
+		} else {
+			ssaVar.setCodeVar(codeVar);
+		}
+	}
+
+	private static void setCodeVarType(CodeVar codeVar, Set<SSAVar> vars) {
+		if (vars.size() > 1) {
+			List<ArgType> imTypes = vars.stream()
+					.filter(var -> var.contains(AFlag.METHOD_ARGUMENT))
+					.map(var -> var.getTypeInfo().getType())
+					.distinct()
+					.collect(Collectors.toList());
+			int imCount = imTypes.size();
+			if (imCount == 1) {
+				codeVar.setType(imTypes.get(0));
+			} else if (imCount > 1) {
+				throw new JadxRuntimeException("Several immutable types in one variable: " + imTypes + ", vars: " + vars);
+			}
 		}
 	}
 

jadx-core/src/main/java/jadx/core/dex/visitors/typeinference/TypeInferenceVisitor.java

@@ -102,11 +102,22 @@ public final class TypeInferenceVisitor extends AbstractVisitor {
 
 	private boolean setBestType(SSAVar ssaVar) {
 		try {
+			ArgType codeVarType = ssaVar.getCodeVar().getType();
+			if (codeVarType != null) {
+				return applyImmutableType(ssaVar, codeVarType);
+			}
 			RegisterArg assignArg = ssaVar.getAssign();
-			if (!assignArg.isTypeImmutable()) {
+			if (assignArg.isTypeImmutable()) {
+				return applyImmutableType(ssaVar, assignArg.getInitType());
+			}
 			return calculateFromBounds(ssaVar);
+		} catch (Exception e) {
+			LOG.error("Failed to calculate best type for var: {}", ssaVar);
+			return false;
+		}
 	}
-			ArgType initType = assignArg.getInitType();
+
+	private boolean applyImmutableType(SSAVar ssaVar, ArgType initType) {
 		TypeUpdateResult result = typeUpdate.apply(ssaVar, initType);
 		if (result == TypeUpdateResult.REJECT) {
 			if (Consts.DEBUG) {
@@ -114,18 +125,22 @@ public final class TypeInferenceVisitor extends AbstractVisitor {
 			}
 			return false;
 		}
-			return true;
-		} catch (Exception e) {
-			LOG.error("Failed to calculate best type for var: {}", ssaVar);
-			return false;
-		}
+		return result == TypeUpdateResult.CHANGED;
 	}
 
 	private boolean calculateFromBounds(SSAVar ssaVar) {
 		TypeInfo typeInfo = ssaVar.getTypeInfo();
 		Set<ITypeBound> bounds = typeInfo.getBounds();
 		Optional<ArgType> bestTypeOpt = selectBestTypeFromBounds(bounds);
-		if (bestTypeOpt.isPresent()) {
+		if (!bestTypeOpt.isPresent()) {
+			if (Consts.DEBUG) {
+				LOG.warn("Failed to select best type from bounds, count={} : ", bounds.size());
+				for (ITypeBound bound : bounds) {
+					LOG.warn("  {}", bound);
+				}
+			}
+			return false;
+		}
 		ArgType candidateType = bestTypeOpt.get();
 		TypeUpdateResult result = typeUpdate.apply(ssaVar, candidateType);
 		if (result == TypeUpdateResult.REJECT) {
@@ -140,14 +155,6 @@ public final class TypeInferenceVisitor extends AbstractVisitor {
 		}
 		return result == TypeUpdateResult.CHANGED;
 	}
-		if (Consts.DEBUG) {
-			LOG.warn("Failed to select best type from bounds, count={} : ", bounds.size());
-			for (ITypeBound bound : bounds) {
-				LOG.warn("  {}", bound);
-			}
-		}
-		return false;
-	}
 
 	private Optional<ArgType> selectBestTypeFromBounds(Set<ITypeBound> bounds) {
 		return bounds.stream()

jadx-core/src/main/java/jadx/core/dex/visitors/typeinference/TypeInfo.java

 package jadx.core.dex.visitors.typeinference;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Set;
 
 import org.jetbrains.annotations.NotNull;
@@ -10,7 +10,7 @@ import jadx.core.dex.instructions.args.ArgType;
 public class TypeInfo {
 	private ArgType type = ArgType.UNKNOWN;
 
-	private final Set<ITypeBound> bounds = new HashSet<>();
+	private final Set<ITypeBound> bounds = new LinkedHashSet<>();
 
 	@NotNull
 	public ArgType getType() {

jadx-core/src/main/java/jadx/core/dex/visitors/typeinference/TypeUpdate.java

@@ -48,7 +48,7 @@ public final class TypeUpdate {
 		if (candidateType == null) {
 			return REJECT;
 		}
-		if (!candidateType.isTypeKnown() && ssaVar.getTypeInfo().getType().isTypeKnown()) {
+		if (!candidateType.isTypeKnown()/* && ssaVar.getTypeInfo().getType().isTypeKnown()*/) {
 			return REJECT;
 		}
 
@@ -86,14 +86,14 @@ public final class TypeUpdate {
 			return SAME;
 		}
 		TypeCompareEnum compareResult = comparator.compareTypes(candidateType, currentType);
+		if (arg.isTypeImmutable() && currentType != ArgType.UNKNOWN) {
+			// don't changed type
 			if (compareResult == TypeCompareEnum.CONFLICT) {
 				if (Consts.DEBUG) {
 					LOG.debug("Type rejected for {} due to conflict: candidate={}, current={}", arg, candidateType, currentType);
 				}
 				return REJECT;
 			}
-		if (arg.isTypeImmutable() && currentType != ArgType.UNKNOWN) {
-			// don't changed type, conflict already rejected
 			return SAME;
 		}
 		if (compareResult.isWider()) {

jadx-core/src/test/java/jadx/tests/integration/trycatch/TestTryCatchFinally6.java

@@ -56,13 +56,13 @@ public class TestTryCatchFinally6 extends IntegrationTest {
 		String code = cls.getCode().toString();
 
 		assertThat(code, containsLines(2,
-				"FileInputStream fileInputStream = null;",
+				"InputStream inputStream = null;",
 				"try {",
 				indent() + "call();",
-				indent() + "fileInputStream = new FileInputStream(\"1.txt\");",
+				indent() + "inputStream = new FileInputStream(\"1.txt\");",
 				"} finally {",
-				indent() + "if (fileInputStream != null) {",
-				indent() + indent() + "fileInputStream.close();",
+				indent() + "if (inputStream != null) {",
+				indent() + indent() + "inputStream.close();",
 				indent() + "}",
 				"}"
 		));

jadx-core/src/test/java/jadx/tests/integration/variables/TestVariablesGeneric.java

@@ -24,7 +24,7 @@ public class TestVariablesGeneric extends SmaliTest {
 	@Test
 	public void test() {
 		disableCompilation();
-		ClassNode cls = getClassNodeFromSmaliWithPath("variables", "TestVariablesGeneric");
+		ClassNode cls = getClassNodeFromSmaliWithPkg("variables", "TestVariablesGeneric");
 		String code = cls.getCode().toString();
 
 		assertThat(code, not(containsString("iVar2")));

jadx-core/src/test/smali/variables/TestVariablesGeneric.smali

-.class public LTestVariablesGeneric;
+.class public Lvariables/TestVariablesGeneric;
 .super Ljava/lang/Object;
 .source "SourceFile"