[clang-tidy] Migrate objc-super-self to use isDerivedFrom 🚛

[stephanemoore]

Summary

This migrates objc-super-self to isDerivedFrom as it now supports
matching Objective-C interface declarations.

Test Notes:
Ran clang tools tests.

[stephanemoore]

Fix example matches in comment.

[aaron.ballman]

LGTM!

[gribozavr]

LGTM, thanks!

clang-tools-extra/clang-tidy/objc/SuperSelfCheck.cpp

 ///   - (instancetype)init;
 ///   - (instancetype)initWithInt:(int)i;
 ///   + (instancetype)init;
 ///   - (void)bar;
 ///   @end
 /// \endcode
 AST_MATCHER(ObjCMethodDecl, isInitializer) {
   return Node.getMethodFamily() == OMF_init;
 }
 
-/// \brief Matches Objective-C implementations of classes that directly or
-/// indirectly have a superclass matching \c InterfaceDecl.
-///
-/// Note that a class is not considered to be a subclass of itself.
+/// \brief Matches Objective-C implementations with interfaces that match
+/// \c Base.
 ///
 /// Example matches implementation declarations for Y and Z.
-///   (matcher = objcInterfaceDecl(isSubclassOf(hasName("X"))))
+///   (matcher = objcImplementationDecl(hasInterface(hasName("X"))))
 /// \code
 ///   @interface X
 ///   @end
-///   @interface Y : X
-///   @end
-///   @implementation Y  // directly derived
-///   @end
-///   @interface Z : Y
+///   @implementation X
 ///   @end
-///   @implementation Z  // indirectly derived
+///   @interface Y
+//    @end
+///   @implementation Y
 ///   @end
 /// \endcode
-AST_MATCHER_P(ObjCImplementationDecl, isSubclassOf,
-              ast_matchers::internal::Matcher<ObjCInterfaceDecl>,
-              InterfaceDecl) {
-  // Check if any of the superclasses of the class match.
-  for (const ObjCInterfaceDecl *SuperClass =
-           Node.getClassInterface()->getSuperClass();
-       SuperClass != nullptr; SuperClass = SuperClass->getSuperClass()) {
-    if (InterfaceDecl.matches(*SuperClass, Finder, Builder))
-      return true;
-  }
-
-  // No matches found.
-  return false;
+AST_MATCHER_P(ObjCImplementationDecl, hasInterface,
+              ast_matchers::internal::Matcher<ObjCInterfaceDecl>, Base) {
+  const ObjCInterfaceDecl *InterfaceDecl = Node.getClassInterface();
+  return Base.matches(*InterfaceDecl, Finder, Builder);
 }
 
 /// \brief Matches Objective-C message expressions where the receiver is the
 /// super instance.
 ///
 /// Example matches the invocations of -banana and -orange.
 ///   (matcher = objcMessageExpr(isMessagingSuperInstance()))
 /// \code
 ///   - (void)banana {
 ///     [self apple]

 }
 
 } // namespace
 
 void SuperSelfCheck::registerMatchers(MatchFinder *Finder) {
   // This check should only be applied to Objective-C sources.
   if (!getLangOpts().ObjC)
     return;
 
   Finder->addMatcher(
-      objcMessageExpr(
-          hasSelector("self"), isMessagingSuperInstance(),
-          hasAncestor(objcMethodDecl(isInitializer(),
-                                     hasDeclContext(objcImplementationDecl(
-                                         isSubclassOf(hasName("NSObject")))))))
+      objcMessageExpr(hasSelector("self"), isMessagingSuperInstance(),
+                      hasAncestor(objcMethodDecl(
+                          isInitializer(),
+                          hasDeclContext(objcImplementationDecl(hasInterface(
+                              isDerivedFrom(hasName("NSObject"))))))))
           .bind("message"),
       this);
 }
 
 void SuperSelfCheck::check(const MatchFinder::MatchResult &Result) {
   const auto *Message = Result.Nodes.getNodeAs<ObjCMessageExpr>("message");
 
   auto Diag = diag(Message->getExprLoc(), "suspicious invocation of %0 in "
                                           "initializer; did you mean to "
                                           "invoke a superclass initializer?")