From e444ecb2c74869b7dfe23847d32f4c7559098734 Mon Sep 17 00:00:00 2001
From: Skylot <skylot@gmail.com>
Date: Mon, 17 Feb 2020 19:30:29 +0000
Subject: [PATCH] fix: improve wildcard types compare (#857)

---
 .../visitors/typeinference/TypeCompare.java   | 23 ++++++++++++++++++-
 .../typeinference/TypeCompareTest.java        | 22 +++++++++++++++---
 2 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/jadx-core/src/main/java/jadx/core/dex/visitors/typeinference/TypeCompare.java b/jadx-core/src/main/java/jadx/core/dex/visitors/typeinference/TypeCompare.java
index 3e7905695..cf05bec9b 100644
--- a/jadx-core/src/main/java/jadx/core/dex/visitors/typeinference/TypeCompare.java
+++ b/jadx-core/src/main/java/jadx/core/dex/visitors/typeinference/TypeCompare.java
@@ -169,7 +169,12 @@ public class TypeCompare {
 			if (firstGeneric != secondGeneric) {
 				return firstGeneric ? NARROW_BY_GENERIC : WIDER_BY_GENERIC;
 			}
-			// both generics on same object, compare generics arrays
+			// both generics on same object
+			if (first.getWildcardBound() != null && second.getWildcardBound() != null) {
+				// both wildcards
+				return compareWildcardTypes(first, second);
+			}
+			// compare generics arrays
 			ArgType[] firstGenericTypes = first.getGenericTypes();
 			ArgType[] secondGenericTypes = second.getGenericTypes();
 			int len = firstGenericTypes.length;
@@ -198,6 +203,22 @@ public class TypeCompare {
 		return TypeCompareEnum.CONFLICT;
 	}
 
+	private TypeCompareEnum compareWildcardTypes(ArgType first, ArgType second) {
+		WildcardBound firstWildcardBound = first.getWildcardBound();
+		WildcardBound secondWildcardBound = second.getWildcardBound();
+		if (firstWildcardBound == WildcardBound.UNBOUND) {
+			return WIDER;
+		}
+		if (secondWildcardBound == WildcardBound.UNBOUND) {
+			return NARROW;
+		}
+		TypeCompareEnum wildcardCompare = compareTypes(first.getWildcardType(), second.getWildcardType());
+		if (firstWildcardBound == secondWildcardBound) {
+			return wildcardCompare;
+		}
+		return CONFLICT;
+	}
+
 	private TypeCompareEnum compareGenericTypeWithObject(ArgType genericType, ArgType objType) {
 		List<ArgType> extendTypes = genericType.getExtendTypes();
 		if (extendTypes == null || extendTypes.isEmpty()) {
diff --git a/jadx-core/src/test/java/jadx/core/dex/visitors/typeinference/TypeCompareTest.java b/jadx-core/src/test/java/jadx/core/dex/visitors/typeinference/TypeCompareTest.java
index 356a46544..1660b3478 100644
--- a/jadx-core/src/test/java/jadx/core/dex/visitors/typeinference/TypeCompareTest.java
+++ b/jadx-core/src/test/java/jadx/core/dex/visitors/typeinference/TypeCompareTest.java
@@ -12,6 +12,7 @@ import jadx.NotYetImplemented;
 import jadx.NotYetImplementedExtension;
 import jadx.api.JadxArgs;
 import jadx.core.dex.instructions.args.ArgType;
+import jadx.core.dex.instructions.args.ArgType.WildcardBound;
 import jadx.core.dex.nodes.RootNode;
 
 import static jadx.core.dex.instructions.args.ArgType.BOOLEAN;
@@ -28,6 +29,7 @@ import static jadx.core.dex.instructions.args.ArgType.UNKNOWN_ARRAY;
 import static jadx.core.dex.instructions.args.ArgType.UNKNOWN_OBJECT;
 import static jadx.core.dex.instructions.args.ArgType.array;
 import static jadx.core.dex.instructions.args.ArgType.generic;
+import static jadx.core.dex.instructions.args.ArgType.object;
 import static jadx.core.dex.instructions.args.ArgType.wildcard;
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -83,7 +85,7 @@ public class TypeCompareTest {
 
 		check(array(OBJECT), array(INT), TypeCompareEnum.CONFLICT);
 
-		ArgType integerType = ArgType.object("java.lang.Integer");
+		ArgType integerType = object("java.lang.Integer");
 		check(array(OBJECT), array(integerType), TypeCompareEnum.WIDER);
 		check(array(INT), array(integerType), TypeCompareEnum.CONFLICT);
 		check(array(INT), array(INT), TypeCompareEnum.EQUAL);
@@ -95,8 +97,8 @@ public class TypeCompareTest {
 
 	@Test
 	public void compareGenerics() {
-		ArgType mapCls = ArgType.object("java.util.Map");
-		ArgType setCls = ArgType.object("java.util.Set");
+		ArgType mapCls = object("java.util.Map");
+		ArgType setCls = object("java.util.Set");
 
 		ArgType keyType = ArgType.genericType("K");
 		ArgType valueType = ArgType.genericType("V");
@@ -113,6 +115,20 @@ public class TypeCompareTest {
 		// TODO implement compare for wildcard with bounds
 	}
 
+	@Test
+	public void compareWildCards() {
+		ArgType clsWildcard = generic(CLASS.getObject(), wildcard());
+		ArgType clsExtendedWildcard = generic(CLASS.getObject(), wildcard(STRING, WildcardBound.EXTENDS));
+		check(clsWildcard, clsExtendedWildcard, TypeCompareEnum.WIDER);
+
+		ArgType listWildcard = generic(CLASS.getObject(), wildcard(object("java.util.List"), WildcardBound.EXTENDS));
+		ArgType collWildcard = generic(CLASS.getObject(), wildcard(object("java.util.Collection"), WildcardBound.EXTENDS));
+		check(listWildcard, collWildcard, TypeCompareEnum.NARROW);
+
+		ArgType collSuperWildcard = generic(CLASS.getObject(), wildcard(object("java.util.Collection"), WildcardBound.SUPER));
+		check(collSuperWildcard, listWildcard, TypeCompareEnum.CONFLICT);
+	}
+
 	@Test
 	public void compareGenericTypes() {
 		ArgType vType = ArgType.genericType("V");