fix: improve generated code on errors

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

@@ -370,7 +370,7 @@ public class ClassGen {
 			if (fv != null) {
 				code.add(" = ");
 				if (fv.getValue() == null) {
-					code.add(TypeGen.literalToString(0, f.getType(), cls));
+					code.add(TypeGen.literalToString(0, f.getType(), cls, fallback));
 				} else {
 					if (fv.getValueType() == InitType.CONST) {
 						annotationGen.encodeValue(code, fv.getValue());

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

@@ -138,7 +138,7 @@ public class InsnGen {
 	}
 
 	private String lit(LiteralArg arg) {
-		return TypeGen.literalToString(arg.getLiteral(), arg.getType(), mth);
+		return TypeGen.literalToString(arg.getLiteral(), arg.getType(), mth, fallback);
 	}
 
 	private void instanceField(CodeWriter code, FieldInfo field, InsnArg arg) throws CodegenException {

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

@@ -148,7 +148,13 @@ public class MethodGen {
 			if (var.isFinal()) {
 				code.add("final ");
 			}
-			ArgType argType = var.getType();
+			ArgType argType;
+			if (var.getType() == ArgType.UNKNOWN) {
+				// occur on decompilation errors
+				argType = mthArg.getInitType();
+			} else {
+				argType = var.getType();
+			}
 			if (!it.hasNext() && mth.getAccessFlags().isVarArgs()) {
 				// change last array argument to varargs
 				if (argType.isArray()) {

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

@@ -266,7 +266,7 @@ public class RegionGen extends InsnGen {
 						}
 					}
 				} else if (k instanceof Integer) {
-					code.add(TypeGen.literalToString((Integer) k, arg.getType(), mth));
+					code.add(TypeGen.literalToString((Integer) k, arg.getType(), mth, fallback));
 				} else {
 					throw new JadxRuntimeException("Unexpected key in switch: " + (k != null ? k.getClass() : null));
 				}

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

@@ -33,14 +33,14 @@ public class TypeGen {
 	 *
 	 * @throws JadxRuntimeException for incorrect type or literal value
 	 */
-	public static String literalToString(long lit, ArgType type, IDexNode dexNode) {
-		return literalToString(lit, type, dexNode.root().getStringUtils());
+	public static String literalToString(long lit, ArgType type, IDexNode dexNode, boolean fallback) {
+		return literalToString(lit, type, dexNode.root().getStringUtils(), fallback);
 	}
 
-	public static String literalToString(long lit, ArgType type, StringUtils stringUtils) {
+	public static String literalToString(long lit, ArgType type, StringUtils stringUtils, boolean fallback) {
 		if (type == null || !type.isTypeKnown()) {
 			String n = Long.toString(lit);
-			if (Math.abs(lit) > 100) {
+			if (fallback && Math.abs(lit) > 100) {
 				StringBuilder sb = new StringBuilder();
 				sb.append(n).append("(0x").append(Long.toHexString(lit));
 				if (type == null || type.contains(PrimitiveType.FLOAT)) {

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

@@ -70,7 +70,7 @@ public final class LiteralArg extends InsnArg {
 	@Override
 	public String toString() {
 		try {
-			String value = TypeGen.literalToString(literal, getType(), DEF_STRING_UTILS);
+			String value = TypeGen.literalToString(literal, getType(), DEF_STRING_UTILS, true);
 			if (getType().equals(ArgType.BOOLEAN) && (value.equals("true") || value.equals("false"))) {
 				return value;
 			}

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

@@ -5,11 +5,15 @@ import java.util.List;
 
 import org.jetbrains.annotations.Nullable;
 
+import com.android.dx.rop.code.AccessFlags;
+
 import jadx.core.codegen.TypeGen;
 import jadx.core.deobf.NameMapper;
 import jadx.core.dex.attributes.AFlag;
+import jadx.core.dex.attributes.AType;
 import jadx.core.dex.attributes.nodes.EnumClassAttr;
 import jadx.core.dex.attributes.nodes.EnumClassAttr.EnumField;
+import jadx.core.dex.info.AccessInfo;
 import jadx.core.dex.info.ClassInfo;
 import jadx.core.dex.info.FieldInfo;
 import jadx.core.dex.info.MethodInfo;
@@ -41,6 +45,11 @@ public class EnumVisitor extends AbstractVisitor {
 	@Override
 	public boolean visit(ClassNode cls) throws JadxException {
 		if (!cls.isEnum()) {
+			AccessInfo accessFlags = cls.getAccessFlags();
+			if (accessFlags.isEnum()) {
+				cls.setAccessFlags(accessFlags.remove(AccessFlags.ACC_ENUM));
+				cls.addAttr(AType.COMMENTS, "'enum' access flag removed");
+			}
 			return true;
 		}
 		// search class init method

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

@@ -28,7 +28,7 @@ public class FixAccessModifiers extends AbstractVisitor {
 			return;
 		}
 		int newVisFlag = fixVisibility(mth);
-		if (newVisFlag != 0) {
+		if (newVisFlag != -1) {
 			changeVisibility(mth, newVisFlag);
 		}
 	}
@@ -38,7 +38,7 @@ public class FixAccessModifiers extends AbstractVisitor {
 		AccessInfo newAccFlags = accessFlags.changeVisibility(newVisFlag);
 		if (newAccFlags != accessFlags) {
 			node.setAccessFlags(newAccFlags);
-			node.addAttr(AType.COMMENTS, "access modifiers changed from: " + accessFlags.rawString());
+			node.addAttr(AType.COMMENTS, "access modifiers changed from: " + accessFlags.getVisibility().rawString());
 		}
 	}
 
@@ -52,9 +52,15 @@ public class FixAccessModifiers extends AbstractVisitor {
 				// make abstract methods public
 				return AccessFlags.ACC_PUBLIC;
 			}
+			// enum constructor can't be public
+			if (accessFlags.isConstructor()
+					&& accessFlags.isPublic()
+					&& mth.getParentClass().isEnum()) {
+				return 0;
+			}
 			if (accessFlags.isConstructor() || accessFlags.isStatic()) {
 				// TODO: make public if used outside
-				return 0;
+				return -1;
 			}
 			// make other direct methods private
 			return AccessFlags.ACC_PRIVATE;

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

@@ -103,7 +103,9 @@ public class LoopRegionVisitor extends AbstractVisitor implements IRegionVisitor
 		}
 		RegisterArg initArg = phiInsn.getArg(0);
 		InsnNode initInsn = initArg.getAssignInsn();
-		if (initInsn == null || initArg.getSVar().getUseCount() != 1) {
+		if (initInsn == null
+				|| initInsn.contains(AFlag.DONT_GENERATE)
+				|| initArg.getSVar().getUseCount() != 1) {
 			return false;
 		}
 		if (!usedOnlyInLoop(mth, loopRegion, arg)) {

jadx-core/src/test/java/jadx/tests/integration/enums/TestEnums3.java

@@ -44,6 +44,6 @@ public class TestEnums3 extends IntegrationTest {
 		assertThat(code, containsOne("ONE(1)"));
 		// assertThat(code, containsOne("THREE(three)"));
 		// assertThat(code, containsOne("assertTrue(Numbers.ONE.getNum() == 1);"));
-		assertThat(code, containsOne("private Numbers(int n) {"));
+		assertThat(code, containsOne("Numbers(int n) {"));
 	}
 }