core: fix type in fill-array instruction

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

@@ -30,6 +30,8 @@ import jadx.core.dex.nodes.FieldNode;
 import jadx.core.dex.nodes.InsnNode;
 import jadx.core.dex.nodes.MethodNode;
 import jadx.core.dex.nodes.RootNode;
+import jadx.core.utils.ErrorsCounter;
+import jadx.core.utils.InsnUtils;
 import jadx.core.utils.StringUtils;
 import jadx.core.utils.exceptions.CodegenException;
 
@@ -450,15 +452,19 @@ public class InsnGen {
 	}
 
 	private void fillArray(FillArrayNode insn, CodeWriter code) throws CodegenException {
-		ArgType elType = insn.getResult().getType().getArrayElement();
-		if (elType.getPrimitiveType() == null) {
-			elType = elType.selectFirst();
+		ArgType insnArrayType = insn.getResult().getType();
+		ArgType insnElementType = insnArrayType.getArrayElement();
+		ArgType elType = insn.getElementType();
+		if (!elType.equals(insnElementType) && !insnArrayType.equals(ArgType.OBJECT)) {
+			ErrorsCounter.methodError(mth,
+					"Incorrect type for fill-array insn " + InsnUtils.formatOffset(insn.getOffset()));
 		}
 		StringBuilder str = new StringBuilder();
+		Object data = insn.getData();
 		switch (elType.getPrimitiveType()) {
 			case BOOLEAN:
 			case BYTE:
-				byte[] array = (byte[]) insn.getData();
+				byte[] array = (byte[]) data;
 				for (byte b : array) {
 					str.append(TypeGen.literalToString(b, elType));
 					str.append(", ");
@@ -466,7 +472,7 @@ public class InsnGen {
 				break;
 			case SHORT:
 			case CHAR:
-				short[] sarray = (short[]) insn.getData();
+				short[] sarray = (short[]) data;
 				for (short b : sarray) {
 					str.append(TypeGen.literalToString(b, elType));
 					str.append(", ");
@@ -474,7 +480,7 @@ public class InsnGen {
 				break;
 			case INT:
 			case FLOAT:
-				int[] iarray = (int[]) insn.getData();
+				int[] iarray = (int[]) data;
 				for (int b : iarray) {
 					str.append(TypeGen.literalToString(b, elType));
 					str.append(", ");
@@ -482,7 +488,7 @@ public class InsnGen {
 				break;
 			case LONG:
 			case DOUBLE:
-				long[] larray = (long[]) insn.getData();
+				long[] larray = (long[]) data;
 				for (long b : larray) {
 					str.append(TypeGen.literalToString(b, elType));
 					str.append(", ");
@@ -494,7 +500,7 @@ public class InsnGen {
 		}
 		int len = str.length();
 		str.delete(len - 2, len);
-		code.add("new ").add(useType(elType)).add("[] { ").add(str.toString()).add(" }");
+		code.add("new ").add(useType(elType)).add("[]{").add(str.toString()).add('}');
 	}
 
 	private void makeConstructor(ConstructorInsn insn, CodeWriter code, EnumSet<IGState> state)

jadx-core/src/main/java/jadx/core/dex/instructions/FillArrayNode.java

@@ -4,18 +4,17 @@ import jadx.core.dex.instructions.args.ArgType;
 import jadx.core.dex.instructions.args.InsnArg;
 import jadx.core.dex.instructions.args.PrimitiveType;
 import jadx.core.dex.nodes.InsnNode;
+import jadx.core.utils.exceptions.JadxRuntimeException;
 
 import com.android.dx.io.instructions.FillArrayDataPayloadDecodedInstruction;
 
 public class FillArrayNode extends InsnNode {
 
 	private final Object data;
+	private ArgType elemType;
 
 	public FillArrayNode(int resReg, FillArrayDataPayloadDecodedInstruction payload) {
 		super(InsnType.FILL_ARRAY, 0);
-
-		this.data = payload.getData();
-
 		ArgType elType;
 		switch (payload.getElementWidthUnit()) {
 			case 1:
@@ -32,12 +31,26 @@ public class FillArrayNode extends InsnNode {
 				break;
 
 			default:
-				throw new AssertionError();
+				throw new JadxRuntimeException("Unknown array element width: " + payload.getElementWidthUnit());
 		}
 		setResult(InsnArg.reg(resReg, ArgType.array(elType)));
+
+		this.data = payload.getData();
+		this.elemType = elType;
 	}
 
 	public Object getData() {
 		return data;
 	}
+
+	public ArgType getElementType() {
+		return elemType;
+	}
+
+	public void mergeElementType(ArgType foundElemType) {
+		ArgType r = ArgType.merge(elemType, foundElemType);
+		if (r != null) {
+			elemType = r;
+		}
+	}
 }

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

@@ -339,7 +339,7 @@ public abstract class ArgType {
 	}
 
 	public static ArgType merge(ArgType a, ArgType b) {
-		if (a == b)
+		if (a.equals(b))
 			return a;
 
 		if (b == null || a == null)
@@ -352,9 +352,9 @@ public abstract class ArgType {
 	}
 
 	private static ArgType mergeInternal(ArgType a, ArgType b) {
-		if (a == UNKNOWN)
+		if (a == UNKNOWN) {
 			return b;
-
+		}
 		if (!a.isTypeKnown()) {
 			if (b.isTypeKnown()) {
 				if (a.contains(b.getPrimitiveType()))
@@ -399,10 +399,22 @@ public abstract class ArgType {
 					return (obj == null ? null : object(obj));
 				}
 			}
-			if (a.isArray() && b.isArray()) {
-				ArgType res = merge(a.getArrayElement(), b.getArrayElement());
+			if (a.isArray()) {
+				if (b.isArray()) {
+					ArgType ea = a.getArrayElement();
+					ArgType eb = b.getArrayElement();
+					if (ea.isPrimitive() && eb.isPrimitive()) {
+						return OBJECT;
+					} else {
+						ArgType res = merge(ea, eb);
 						return (res == null ? null : ArgType.array(res));
 					}
+				} else if (b.equals(OBJECT)) {
+					return OBJECT;
+				} else {
+					return null;
+				}
+			}
 			if (a.isPrimitive() && b.isPrimitive() && a.getRegCount() == b.getRegCount()) {
 				return primitive(PrimitiveType.getSmaller(a.getPrimitiveType(), b.getPrimitiveType()));
 			}

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

@@ -5,6 +5,7 @@ import jadx.core.dex.attributes.AttributeType;
 import jadx.core.dex.info.MethodInfo;
 import jadx.core.dex.instructions.ConstClassNode;
 import jadx.core.dex.instructions.ConstStringNode;
+import jadx.core.dex.instructions.FillArrayNode;
 import jadx.core.dex.instructions.IndexInsnNode;
 import jadx.core.dex.instructions.InsnType;
 import jadx.core.dex.instructions.InvokeNode;
@@ -164,6 +165,7 @@ public class ModVisitor extends AbstractVisitor {
 							InsnNode ni = block.getInstructions().get(next);
 							if (ni.getType() == InsnType.FILL_ARRAY) {
 								ni.getResult().merge(insn.getResult());
+								((FillArrayNode) ni).mergeElementType(insn.getResult().getType().getArrayElement());
 								remover.add(insn);
 							}
 						}

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

 package jadx.core.utils;
 
+import jadx.core.dex.attributes.AttributeFlag;
 import jadx.core.dex.attributes.IAttributeNode;
 import jadx.core.dex.attributes.JadxErrorAttr;
 import jadx.core.dex.nodes.ClassNode;
@@ -40,6 +41,7 @@ public class ErrorsCounter {
 			}
 			node.getAttributes().add(new JadxErrorAttr(e));
 		} else {
+			node.getAttributes().add(AttributeFlag.INCONSISTENT_CODE);
 			LOG.error(msg);
 		}
 	}

jadx-core/src/test/java/jadx/tests/functional/TypeMergeTest.java

@@ -11,11 +11,13 @@ import org.junit.Before;
 import org.junit.Test;
 
 import static jadx.core.dex.instructions.args.ArgType.BOOLEAN;
+import static jadx.core.dex.instructions.args.ArgType.BYTE;
 import static jadx.core.dex.instructions.args.ArgType.CHAR;
 import static jadx.core.dex.instructions.args.ArgType.INT;
 import static jadx.core.dex.instructions.args.ArgType.LONG;
 import static jadx.core.dex.instructions.args.ArgType.NARROW;
 import static jadx.core.dex.instructions.args.ArgType.OBJECT;
+import static jadx.core.dex.instructions.args.ArgType.STRING;
 import static jadx.core.dex.instructions.args.ArgType.UNKNOWN;
 import static jadx.core.dex.instructions.args.ArgType.UNKNOWN_OBJECT;
 import static jadx.core.dex.instructions.args.ArgType.genericType;
@@ -57,6 +59,13 @@ public class TypeMergeTest {
 				unknown(PrimitiveType.OBJECT, PrimitiveType.ARRAY),
 				unknown(PrimitiveType.OBJECT));
 
+		check(ArgType.array(INT), ArgType.array(BYTE), ArgType.OBJECT);
+		first(ArgType.array(INT), ArgType.array(INT));
+		first(ArgType.array(STRING), ArgType.array(STRING));
+
+		first(OBJECT, ArgType.array(INT));
+		first(OBJECT, ArgType.array(STRING));
+
 		ArgType objExc = object("java.lang.Exception");
 		ArgType objThr = object("java.lang.Throwable");
 		ArgType objIO = object("java.io.IOException");

jadx-samples/src/main/java/jadx/samples/TestArrays.java

@@ -4,7 +4,7 @@ public class TestArrays extends AbstractTest {
 
 	public int test1(int i) {
 		// fill-array-data
-		int[] a = new int[] { 1, 2, 3, 5 };
+		int[] a = new int[]{1, 2, 3, 5};
 		return a[i];
 	}
 
@@ -20,11 +20,27 @@ public class TestArrays extends AbstractTest {
 		return a.length;
 	}
 
+	private static Object test4(int type) {
+		if (type == 1) {
+			return new int[]{1, 2};
+		} else if (type == 2) {
+			return new float[]{1, 2};
+		} else if (type == 3) {
+			return new short[]{1, 2};
+		} else if (type == 4) {
+			return new byte[]{1, 2};
+		} else {
+			return null;
+		}
+	}
+
 	@Override
 	public boolean testRun() throws Exception {
 		assertEquals(test1(2), 3);
 		assertEquals(test2(2), 2);
 		assertEquals(test3(2), 2);
+
+		assertTrue(test4(4) instanceof byte[]);
 		return true;
 	}