[clang] Update isDerivedFrom to support Objective-C classes 🔍

Summary:
This change updates `isDerivedFrom` to support Objective-C classes by
converting it to a polymorphic matcher.

Notes:
The matching behavior for Objective-C classes is modeled to match the
behavior of `isDerivedFrom` with C++ classes. To that effect,
`isDerivedFrom` matches aliased types of derived Objective-C classes,
including compatibility aliases. To achieve this, the AST visitor has
been updated to map compatibility aliases to their underlying
Objective-C class.

`isSameOrDerivedFrom` also provides similar behaviors for C++ and
Objective-C classes. The behavior that
`cxxRecordDecl(isSameOrDerivedFrom("X"))` does not match
`class Y {}; typedef Y X;` is mirrored for Objective-C in that
`objcInterfaceDecl(isSameOrDerivedFrom("X"))` does not match either
`@interface Y @end typedef Y X;` or
`@interface Y @end @compatibility_alias X Y;`.

Test Notes:
Ran clang unit tests.

Reviewers: aaron.ballman, jordan_rose, rjmccall, klimek, alexfh, gribozavr

Reviewed By: aaron.ballman, gribozavr

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D60543

llvm-svn: 368632

1 files changed, 105 insertions, 0 deletions

diff --git a/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
index 2038e9b6c00..52cd042c965 100644
--- a/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
+++ b/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
@@ -573,6 +573,111 @@ TEST(DeclarationMatcher, IsDerivedFromEmptyName) {
   EXPECT_TRUE(notMatches(Code, cxxRecordDecl(isSameOrDerivedFrom(""))));
 }
 
+TEST(DeclarationMatcher, ObjCClassIsDerived) {
+  DeclarationMatcher IsDerivedFromX = objcInterfaceDecl(isDerivedFrom("X"));
+  EXPECT_TRUE(
+      matchesObjC("@interface X @end @interface Y : X @end", IsDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface X @end @interface Y<__covariant ObjectType> : X @end",
+      IsDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface X @end @compatibility_alias Y X; @interface Z : Y @end",
+      IsDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface X @end typedef X Y; @interface Z : Y @end", IsDerivedFromX));
+  EXPECT_TRUE(notMatchesObjC("@interface X @end", IsDerivedFromX));
+  EXPECT_TRUE(notMatchesObjC("@class X;", IsDerivedFromX));
+  EXPECT_TRUE(notMatchesObjC("@class Y;", IsDerivedFromX));
+  EXPECT_TRUE(notMatchesObjC("@interface X @end @compatibility_alias Y X;",
+                             IsDerivedFromX));
+  EXPECT_TRUE(notMatchesObjC("@interface X @end typedef X Y;", IsDerivedFromX));
+
+  DeclarationMatcher IsDirectlyDerivedFromX =
+      objcInterfaceDecl(isDirectlyDerivedFrom("X"));
+  EXPECT_TRUE(
+      matchesObjC("@interface X @end @interface Y : X @end", IsDirectlyDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface X @end @interface Y<__covariant ObjectType> : X @end",
+      IsDirectlyDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface X @end @compatibility_alias Y X; @interface Z : Y @end",
+      IsDirectlyDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface X @end typedef X Y; @interface Z : Y @end",
+      IsDirectlyDerivedFromX));
+  EXPECT_TRUE(notMatchesObjC("@interface X @end", IsDirectlyDerivedFromX));
+  EXPECT_TRUE(notMatchesObjC("@class X;", IsDirectlyDerivedFromX));
+  EXPECT_TRUE(notMatchesObjC("@class Y;", IsDirectlyDerivedFromX));
+  EXPECT_TRUE(notMatchesObjC("@interface X @end @compatibility_alias Y X;",
+                             IsDirectlyDerivedFromX));
+  EXPECT_TRUE(notMatchesObjC("@interface X @end typedef X Y;",
+                             IsDirectlyDerivedFromX));
+
+  DeclarationMatcher IsAX = objcInterfaceDecl(isSameOrDerivedFrom("X"));
+  EXPECT_TRUE(matchesObjC("@interface X @end @interface Y : X @end", IsAX));
+  EXPECT_TRUE(matchesObjC("@interface X @end", IsAX));
+  EXPECT_TRUE(matchesObjC("@class X;", IsAX));
+  EXPECT_TRUE(notMatchesObjC("@interface Y @end", IsAX));
+  EXPECT_TRUE(notMatchesObjC("@class Y;", IsAX));
+
+  DeclarationMatcher ZIsDerivedFromX =
+      objcInterfaceDecl(hasName("Z"), isDerivedFrom("X"));
+  DeclarationMatcher ZIsDirectlyDerivedFromX =
+      objcInterfaceDecl(hasName("Z"), isDirectlyDerivedFrom("X"));
+  EXPECT_TRUE(matchesObjC(
+      "@interface X @end @interface Y : X @end @interface Z : Y @end",
+      ZIsDerivedFromX));
+  EXPECT_TRUE(matchesObjC("@interface X @end @interface Y : X @end typedef Y "
+                          "V; typedef V W; @interface Z : W @end",
+                          ZIsDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface X @end typedef X Y; @interface Z : Y @end", ZIsDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface X @end typedef X Y; @interface Z : Y @end",
+      ZIsDirectlyDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface A @end typedef A X; typedef A Y; @interface Z : Y @end",
+      ZIsDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface A @end typedef A X; typedef A Y; @interface Z : Y @end",
+      ZIsDirectlyDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface X @end @compatibility_alias Y X; @interface Z : Y @end",
+      ZIsDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface X @end @compatibility_alias Y X; @interface Z : Y @end",
+      ZIsDirectlyDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface Y @end @compatibility_alias X Y; @interface Z : Y @end",
+      ZIsDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface Y @end @compatibility_alias X Y; @interface Z : Y @end",
+      ZIsDirectlyDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface A @end @compatibility_alias X A; @compatibility_alias Y A;"
+      "@interface Z : Y @end", ZIsDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface A @end @compatibility_alias X A; @compatibility_alias Y A;"
+      "@interface Z : Y @end", ZIsDirectlyDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface Y @end typedef Y X; @interface Z : X @end", ZIsDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface Y @end typedef Y X; @interface Z : X @end",
+      ZIsDirectlyDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface A @end @compatibility_alias Y A; typedef Y X;"
+      "@interface Z : A @end", ZIsDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface A @end @compatibility_alias Y A; typedef Y X;"
+      "@interface Z : A @end", ZIsDirectlyDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface A @end typedef A Y; @compatibility_alias X Y;"
+      "@interface Z : A @end", ZIsDerivedFromX));
+  EXPECT_TRUE(matchesObjC(
+      "@interface A @end typedef A Y; @compatibility_alias X Y;"
+      "@interface Z : A @end", ZIsDirectlyDerivedFromX));
+}
+
 TEST(DeclarationMatcher, IsLambda) {
   const auto IsLambda = cxxMethodDecl(ofClass(cxxRecordDecl(isLambda())));
   EXPECT_TRUE(matches("auto x = []{};", IsLambda));