[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

6 files changed, 349 insertions, 34 deletions

diff --git a/clang/docs/LibASTMatchersReference.html b/clang/docs/LibASTMatchersReference.html
index 68d536a0704..d9e867c9519 100644
--- a/clang/docs/LibASTMatchersReference.html
+++ b/clang/docs/LibASTMatchersReference.html
@@ -2576,13 +2576,13 @@ class y;
 </pre></td></tr>
 
 
-<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;</td><td class="name" onclick="toggle('isDerivedFrom1')"><a name="isDerivedFrom1Anchor">isDerivedFrom</a></td><td>std::string BaseName</td></tr>
-<tr><td colspan="4" class="doc" id="isDerivedFrom1"><pre>Overloaded method as shortcut for isDerivedFrom(hasName(...)).
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;</td><td class="name" onclick="toggle('isDerivedFrom2')"><a name="isDerivedFrom2Anchor">isDerivedFrom</a></td><td>std::string BaseName</td></tr>
+<tr><td colspan="4" class="doc" id="isDerivedFrom2"><pre>Overloaded method as shortcut for isDerivedFrom(hasName(...)).
 </pre></td></tr>
 
 
-<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;</td><td class="name" onclick="toggle('isDirectlyDerivedFrom1')"><a name="isDirectlyDerivedFrom1Anchor">isDirectlyDerivedFrom</a></td><td>std::string BaseName</td></tr>
-<tr><td colspan="4" class="doc" id="isDirectlyDerivedFrom1"><pre>Overloaded method as shortcut for isDirectlyDerivedFrom(hasName(...)).
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;</td><td class="name" onclick="toggle('isDirectlyDerivedFrom2')"><a name="isDirectlyDerivedFrom2Anchor">isDirectlyDerivedFrom</a></td><td>std::string BaseName</td></tr>
+<tr><td colspan="4" class="doc" id="isDirectlyDerivedFrom2"><pre>Overloaded method as shortcut for isDirectlyDerivedFrom(hasName(...)).
 </pre></td></tr>
 
 
@@ -2628,8 +2628,8 @@ decltype(x)
 </pre></td></tr>
 
 
-<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;</td><td class="name" onclick="toggle('isSameOrDerivedFrom1')"><a name="isSameOrDerivedFrom1Anchor">isSameOrDerivedFrom</a></td><td>std::string BaseName</td></tr>
-<tr><td colspan="4" class="doc" id="isSameOrDerivedFrom1"><pre>Overloaded method as shortcut for
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;</td><td class="name" onclick="toggle('isSameOrDerivedFrom2')"><a name="isSameOrDerivedFrom2Anchor">isSameOrDerivedFrom</a></td><td>std::string BaseName</td></tr>
+<tr><td colspan="4" class="doc" id="isSameOrDerivedFrom2"><pre>Overloaded method as shortcut for
 isSameOrDerivedFrom(hasName(...)).
 </pre></td></tr>
 
@@ -3593,6 +3593,22 @@ Given
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ObjCInterfaceDecl.html">ObjCInterfaceDecl</a>&gt;</td><td class="name" onclick="toggle('isDerivedFrom3')"><a name="isDerivedFrom3Anchor">isDerivedFrom</a></td><td>std::string BaseName</td></tr>
+<tr><td colspan="4" class="doc" id="isDerivedFrom3"><pre>Overloaded method as shortcut for isDerivedFrom(hasName(...)).
+</pre></td></tr>
+
+
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ObjCInterfaceDecl.html">ObjCInterfaceDecl</a>&gt;</td><td class="name" onclick="toggle('isDirectlyDerivedFrom3')"><a name="isDirectlyDerivedFrom3Anchor">isDirectlyDerivedFrom</a></td><td>std::string BaseName</td></tr>
+<tr><td colspan="4" class="doc" id="isDirectlyDerivedFrom3"><pre>Overloaded method as shortcut for isDirectlyDerivedFrom(hasName(...)).
+</pre></td></tr>
+
+
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ObjCInterfaceDecl.html">ObjCInterfaceDecl</a>&gt;</td><td class="name" onclick="toggle('isSameOrDerivedFrom3')"><a name="isSameOrDerivedFrom3Anchor">isSameOrDerivedFrom</a></td><td>std::string BaseName</td></tr>
+<tr><td colspan="4" class="doc" id="isSameOrDerivedFrom3"><pre>Overloaded method as shortcut for
+isSameOrDerivedFrom(hasName(...)).
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ObjCMessageExpr.html">ObjCMessageExpr</a>&gt;</td><td class="name" onclick="toggle('argumentCountIs2')"><a name="argumentCountIs2Anchor">argumentCountIs</a></td><td>unsigned N</td></tr>
 <tr><td colspan="4" class="doc" id="argumentCountIs2"><pre>Checks that a call expression or a constructor call expression has
 a specific number of arguments (including absent default arguments).
@@ -5248,8 +5264,9 @@ A but not B.
 
 
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;</td><td class="name" onclick="toggle('isDerivedFrom0')"><a name="isDerivedFrom0Anchor">isDerivedFrom</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1NamedDecl.html">NamedDecl</a>&gt; Base</td></tr>
-<tr><td colspan="4" class="doc" id="isDerivedFrom0"><pre>Matches C++ classes that are directly or indirectly derived from
-a class matching Base.
+<tr><td colspan="4" class="doc" id="isDerivedFrom0"><pre>Matches C++ classes that are directly or indirectly derived from a class
+matching Base, or Objective-C classes that directly or indirectly
+subclass a class matching Base.
 
 Note that a class is not considered to be derived from itself.
 
@@ -5265,11 +5282,18 @@ In the following example, Bar matches isDerivedFrom(hasName("X")):
   class Foo;
   typedef Foo X;
   class Bar : public Foo {};  // derived from a type that X is a typedef of
+
+In the following example, Bar matches isDerivedFrom(hasName("NSObject"))
+  @interface NSObject @end
+  @interface Bar : NSObject @end
+
+Usable as: Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;, Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ObjCInterfaceDecl.html">ObjCInterfaceDecl</a>&gt;
 </pre></td></tr>
 
 
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;</td><td class="name" onclick="toggle('isDirectlyDerivedFrom0')"><a name="isDirectlyDerivedFrom0Anchor">isDirectlyDerivedFrom</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1NamedDecl.html">NamedDecl</a>&gt; Base</td></tr>
-<tr><td colspan="4" class="doc" id="isDirectlyDerivedFrom0"><pre>Matches C++ classes that are directly derived from a class matching Base.
+<tr><td colspan="4" class="doc" id="isDirectlyDerivedFrom0"><pre>Matches C++ or Objective-C classes that are directly derived from a class
+matching Base.
 
 Note that a class is not considered to be derived from itself.
 
@@ -6468,6 +6492,61 @@ Given
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ObjCInterfaceDecl.html">ObjCInterfaceDecl</a>&gt;</td><td class="name" onclick="toggle('isDerivedFrom1')"><a name="isDerivedFrom1Anchor">isDerivedFrom</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1NamedDecl.html">NamedDecl</a>&gt; Base</td></tr>
+<tr><td colspan="4" class="doc" id="isDerivedFrom1"><pre>Matches C++ classes that are directly or indirectly derived from a class
+matching Base, or Objective-C classes that directly or indirectly
+subclass a class matching Base.
+
+Note that a class is not considered to be derived from itself.
+
+Example matches Y, Z, C (Base == hasName("X"))
+  class X;
+  class Y : public X {};  // directly derived
+  class Z : public Y {};  // indirectly derived
+  typedef X A;
+  typedef A B;
+  class C : public B {};  // derived from a typedef of X
+
+In the following example, Bar matches isDerivedFrom(hasName("X")):
+  class Foo;
+  typedef Foo X;
+  class Bar : public Foo {};  // derived from a type that X is a typedef of
+
+In the following example, Bar matches isDerivedFrom(hasName("NSObject"))
+  @interface NSObject @end
+  @interface Bar : NSObject @end
+
+Usable as: Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;, Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ObjCInterfaceDecl.html">ObjCInterfaceDecl</a>&gt;
+</pre></td></tr>
+
+
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ObjCInterfaceDecl.html">ObjCInterfaceDecl</a>&gt;</td><td class="name" onclick="toggle('isDirectlyDerivedFrom1')"><a name="isDirectlyDerivedFrom1Anchor">isDirectlyDerivedFrom</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1NamedDecl.html">NamedDecl</a>&gt; Base</td></tr>
+<tr><td colspan="4" class="doc" id="isDirectlyDerivedFrom1"><pre>Matches C++ or Objective-C classes that are directly derived from a class
+matching Base.
+
+Note that a class is not considered to be derived from itself.
+
+Example matches Y, C (Base == hasName("X"))
+  class X;
+  class Y : public X {};  // directly derived
+  class Z : public Y {};  // indirectly derived
+  typedef X A;
+  typedef A B;
+  class C : public B {};  // derived from a typedef of X
+
+In the following example, Bar matches isDerivedFrom(hasName("X")):
+  class Foo;
+  typedef Foo X;
+  class Bar : public Foo {};  // derived from a type that X is a typedef of
+</pre></td></tr>
+
+
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ObjCInterfaceDecl.html">ObjCInterfaceDecl</a>&gt;</td><td class="name" onclick="toggle('isSameOrDerivedFrom1')"><a name="isSameOrDerivedFrom1Anchor">isSameOrDerivedFrom</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1NamedDecl.html">NamedDecl</a>&gt; Base</td></tr>
+<tr><td colspan="4" class="doc" id="isSameOrDerivedFrom1"><pre>Similar to isDerivedFrom(), but also matches classes that directly
+match Base.
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ObjCMessageExpr.html">ObjCMessageExpr</a>&gt;</td><td class="name" onclick="toggle('hasAnyArgument3')"><a name="hasAnyArgument3Anchor">hasAnyArgument</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Expr.html">Expr</a>&gt; InnerMatcher</td></tr>
 <tr><td colspan="4" class="doc" id="hasAnyArgument3"><pre>Matches any argument of a call expression or a constructor call
 expression, or an ObjC-message-send expression.
diff --git a/clang/include/clang/ASTMatchers/ASTMatchers.h b/clang/include/clang/ASTMatchers/ASTMatchers.h
index 6bf20ead1b0..e6d25069f1c 100644
--- a/clang/include/clang/ASTMatchers/ASTMatchers.h
+++ b/clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -2611,8 +2611,9 @@ hasOverloadedOperatorName(StringRef Name) {
       AST_POLYMORPHIC_SUPPORTED_TYPES(CXXOperatorCallExpr, FunctionDecl)>(Name);
 }
 
-/// Matches C++ classes that are directly or indirectly derived from
-/// a class matching \c Base.
+/// Matches C++ classes that are directly or indirectly derived from a class
+/// matching \c Base, or Objective-C classes that directly or indirectly
+/// subclass a class matching \c Base.
 ///
 /// Note that a class is not considered to be derived from itself.
 ///
@@ -2632,36 +2633,80 @@ hasOverloadedOperatorName(StringRef Name) {
 ///   typedef Foo X;
 ///   class Bar : public Foo {};  // derived from a type that X is a typedef of
 /// \endcode
-AST_MATCHER_P(CXXRecordDecl, isDerivedFrom,
-              internal::Matcher<NamedDecl>, Base) {
-  return Finder->classIsDerivedFrom(&Node, Base, Builder, /*Directly=*/false);
+///
+/// In the following example, Bar matches isDerivedFrom(hasName("NSObject"))
+/// \code
+///   @interface NSObject @end
+///   @interface Bar : NSObject @end
+/// \endcode
+///
+/// Usable as: Matcher<CXXRecordDecl>, Matcher<ObjCInterfaceDecl>
+AST_POLYMORPHIC_MATCHER_P(
+    isDerivedFrom,
+    AST_POLYMORPHIC_SUPPORTED_TYPES(CXXRecordDecl, ObjCInterfaceDecl),
+    internal::Matcher<NamedDecl>, Base) {
+  // Check if the node is a C++ struct/union/class.
+  if (const auto *RD = dyn_cast<CXXRecordDecl>(&Node))
+    return Finder->classIsDerivedFrom(RD, Base, Builder, /*Directly=*/false);
+
+  // The node must be an Objective-C class.
+  const auto *InterfaceDecl = cast<ObjCInterfaceDecl>(&Node);
+  return Finder->objcClassIsDerivedFrom(InterfaceDecl, Base, Builder,
+                                        /*Directly=*/false);
 }
 
 /// Overloaded method as shortcut for \c isDerivedFrom(hasName(...)).
-AST_MATCHER_P_OVERLOAD(CXXRecordDecl, isDerivedFrom, std::string, BaseName, 1) {
+AST_POLYMORPHIC_MATCHER_P_OVERLOAD(
+    isDerivedFrom,
+    AST_POLYMORPHIC_SUPPORTED_TYPES(CXXRecordDecl, ObjCInterfaceDecl),
+    std::string, BaseName, 1) {
   if (BaseName.empty())
     return false;
-  return isDerivedFrom(hasName(BaseName)).matches(Node, Finder, Builder);
+
+  const auto M = isDerivedFrom(hasName(BaseName));
+
+  if (const auto *RD = dyn_cast<CXXRecordDecl>(&Node))
+    return Matcher<CXXRecordDecl>(M).matches(*RD, Finder, Builder);
+
+  const auto *InterfaceDecl = cast<ObjCInterfaceDecl>(&Node);
+  return Matcher<ObjCInterfaceDecl>(M).matches(*InterfaceDecl, Finder, Builder);
 }
 
 /// Similar to \c isDerivedFrom(), but also matches classes that directly
 /// match \c Base.
-AST_MATCHER_P_OVERLOAD(CXXRecordDecl, isSameOrDerivedFrom,
-                       internal::Matcher<NamedDecl>, Base, 0) {
-  return Matcher<CXXRecordDecl>(anyOf(Base, isDerivedFrom(Base)))
-      .matches(Node, Finder, Builder);
+AST_POLYMORPHIC_MATCHER_P_OVERLOAD(
+    isSameOrDerivedFrom,
+    AST_POLYMORPHIC_SUPPORTED_TYPES(CXXRecordDecl, ObjCInterfaceDecl),
+    internal::Matcher<NamedDecl>, Base, 0) {
+  const auto M = anyOf(Base, isDerivedFrom(Base));
+
+  if (const auto *RD = dyn_cast<CXXRecordDecl>(&Node))
+    return Matcher<CXXRecordDecl>(M).matches(*RD, Finder, Builder);
+
+  const auto *InterfaceDecl = cast<ObjCInterfaceDecl>(&Node);
+  return Matcher<ObjCInterfaceDecl>(M).matches(*InterfaceDecl, Finder, Builder);
 }
 
 /// Overloaded method as shortcut for
 /// \c isSameOrDerivedFrom(hasName(...)).
-AST_MATCHER_P_OVERLOAD(CXXRecordDecl, isSameOrDerivedFrom, std::string,
-                       BaseName, 1) {
+AST_POLYMORPHIC_MATCHER_P_OVERLOAD(
+    isSameOrDerivedFrom,
+    AST_POLYMORPHIC_SUPPORTED_TYPES(CXXRecordDecl, ObjCInterfaceDecl),
+    std::string, BaseName, 1) {
   if (BaseName.empty())
     return false;
-  return isSameOrDerivedFrom(hasName(BaseName)).matches(Node, Finder, Builder);
+
+  const auto M = isSameOrDerivedFrom(hasName(BaseName));
+
+  if (const auto *RD = dyn_cast<CXXRecordDecl>(&Node))
+    return Matcher<CXXRecordDecl>(M).matches(*RD, Finder, Builder);
+
+  const auto *InterfaceDecl = cast<ObjCInterfaceDecl>(&Node);
+  return Matcher<ObjCInterfaceDecl>(M).matches(*InterfaceDecl, Finder, Builder);
 }
 
-/// Matches C++ classes that are directly derived from a class matching \c Base.
+/// Matches C++ or Objective-C classes that are directly derived from a class
+/// matching \c Base.
 ///
 /// Note that a class is not considered to be derived from itself.
 ///
@@ -2681,18 +2726,34 @@ AST_MATCHER_P_OVERLOAD(CXXRecordDecl, isSameOrDerivedFrom, std::string,
 ///   typedef Foo X;
 ///   class Bar : public Foo {};  // derived from a type that X is a typedef of
 /// \endcode
-AST_MATCHER_P_OVERLOAD(CXXRecordDecl, isDirectlyDerivedFrom,
-                       internal::Matcher<NamedDecl>, Base, 0) {
-  return Finder->classIsDerivedFrom(&Node, Base, Builder, /*Directly=*/true);
+AST_POLYMORPHIC_MATCHER_P_OVERLOAD(
+    isDirectlyDerivedFrom,
+    AST_POLYMORPHIC_SUPPORTED_TYPES(CXXRecordDecl, ObjCInterfaceDecl),
+    internal::Matcher<NamedDecl>, Base, 0) {
+  // Check if the node is a C++ struct/union/class.
+  if (const auto *RD = dyn_cast<CXXRecordDecl>(&Node))
+    return Finder->classIsDerivedFrom(RD, Base, Builder, /*Directly=*/true);
+
+  // The node must be an Objective-C class.
+  const auto *InterfaceDecl = cast<ObjCInterfaceDecl>(&Node);
+  return Finder->objcClassIsDerivedFrom(InterfaceDecl, Base, Builder,
+                                        /*Directly=*/true);
 }
 
 /// Overloaded method as shortcut for \c isDirectlyDerivedFrom(hasName(...)).
-AST_MATCHER_P_OVERLOAD(CXXRecordDecl, isDirectlyDerivedFrom, std::string,
-                       BaseName, 1) {
+AST_POLYMORPHIC_MATCHER_P_OVERLOAD(
+    isDirectlyDerivedFrom,
+    AST_POLYMORPHIC_SUPPORTED_TYPES(CXXRecordDecl, ObjCInterfaceDecl),
+    std::string, BaseName, 1) {
   if (BaseName.empty())
     return false;
-  return isDirectlyDerivedFrom(hasName(BaseName))
-      .matches(Node, Finder, Builder);
+  const auto M = isDirectlyDerivedFrom(hasName(BaseName));
+
+  if (const auto *RD = dyn_cast<CXXRecordDecl>(&Node))
+    return Matcher<CXXRecordDecl>(M).matches(*RD, Finder, Builder);
+
+  const auto *InterfaceDecl = cast<ObjCInterfaceDecl>(&Node);
+  return Matcher<ObjCInterfaceDecl>(M).matches(*InterfaceDecl, Finder, Builder);
 }
 /// Matches the first method of a class or struct that satisfies \c
 /// InnerMatcher.
diff --git a/clang/include/clang/ASTMatchers/ASTMatchersInternal.h b/clang/include/clang/ASTMatchers/ASTMatchersInternal.h
index 7b68d598c8b..46e47a3100b 100644
--- a/clang/include/clang/ASTMatchers/ASTMatchersInternal.h
+++ b/clang/include/clang/ASTMatchers/ASTMatchersInternal.h
@@ -971,7 +971,7 @@ public:
 
   virtual ~ASTMatchFinder() = default;
 
-  /// Returns true if the given class is directly or indirectly derived
+  /// Returns true if the given C++ class is directly or indirectly derived
   /// from a base type matching \c base.
   ///
   /// A class is not considered to be derived from itself.
@@ -980,6 +980,15 @@ public:
                                   BoundNodesTreeBuilder *Builder,
                                   bool Directly) = 0;
 
+  /// Returns true if the given Objective-C class is directly or indirectly
+  /// derived from a base class matching \c base.
+  ///
+  /// A class is not considered to be derived from itself.
+  virtual bool objcClassIsDerivedFrom(const ObjCInterfaceDecl *Declaration,
+                                      const Matcher<NamedDecl> &Base,
+                                      BoundNodesTreeBuilder *Builder,
+                                      bool Directly) = 0;
+
   template <typename T>
   bool matchesChildOf(const T &Node, const DynTypedMatcher &Matcher,
                       BoundNodesTreeBuilder *Builder,
diff --git a/clang/lib/ASTMatchers/ASTMatchFinder.cpp b/clang/lib/ASTMatchers/ASTMatchFinder.cpp
index 6a4715ebe1b..6eb4a2c4268 100644
--- a/clang/lib/ASTMatchers/ASTMatchFinder.cpp
+++ b/clang/lib/ASTMatchers/ASTMatchFinder.cpp
@@ -374,6 +374,12 @@ public:
     return true;
   }
 
+  bool VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *CAD) {
+    const ObjCInterfaceDecl *InterfaceDecl = CAD->getClassInterface();
+    CompatibleAliases[InterfaceDecl].insert(CAD);
+    return true;
+  }
+
   bool TraverseDecl(Decl *DeclNode);
   bool TraverseStmt(Stmt *StmtNode, DataRecursionQueue *Queue = nullptr);
   bool TraverseType(QualType TypeNode);
@@ -433,6 +439,11 @@ public:
                           BoundNodesTreeBuilder *Builder,
                           bool Directly) override;
 
+  bool objcClassIsDerivedFrom(const ObjCInterfaceDecl *Declaration,
+                              const Matcher<NamedDecl> &Base,
+                              BoundNodesTreeBuilder *Builder,
+                              bool Directly) override;
+
   // Implements ASTMatchFinder::matchesChildOf.
   bool matchesChildOf(const ast_type_traits::DynTypedNode &Node,
                       const DynTypedMatcher &Matcher,
@@ -763,6 +774,23 @@ private:
     return false;
   }
 
+  bool
+  objcClassHasMatchingCompatibilityAlias(const ObjCInterfaceDecl *InterfaceDecl,
+                                         const Matcher<NamedDecl> &Matcher,
+                                         BoundNodesTreeBuilder *Builder) {
+    auto Aliases = CompatibleAliases.find(InterfaceDecl);
+    if (Aliases == CompatibleAliases.end())
+      return false;
+    for (const ObjCCompatibleAliasDecl *Alias : Aliases->second) {
+      BoundNodesTreeBuilder Result(*Builder);
+      if (Matcher.matches(*Alias, this, &Result)) {
+        *Builder = std::move(Result);
+        return true;
+      }
+    }
+    return false;
+  }
+
   /// Bucket to record map.
   ///
   /// Used to get the appropriate bucket for each matcher.
@@ -787,6 +815,11 @@ private:
   // Maps a canonical type to its TypedefDecls.
   llvm::DenseMap<const Type*, std::set<const TypedefNameDecl*> > TypeAliases;
 
+  // Maps an Objective-C interface to its ObjCCompatibleAliasDecls.
+  llvm::DenseMap<const ObjCInterfaceDecl *,
+                 llvm::SmallPtrSet<const ObjCCompatibleAliasDecl *, 2>>
+      CompatibleAliases;
+
   // Maps (matcher, node) -> the match result for memoization.
   typedef std::map<MatchKey, MemoizedMatchResult> MemoizationMap;
   MemoizationMap ResultCache;
@@ -813,7 +846,7 @@ getAsCXXRecordDeclOrPrimaryTemplate(const Type *TypeNode) {
   return nullptr;
 }
 
-// Returns true if the given class is directly or indirectly derived
+// Returns true if the given C++ class is directly or indirectly derived
 // from a base type with the given name.  A class is not considered to be
 // derived from itself.
 bool MatchASTVisitor::classIsDerivedFrom(const CXXRecordDecl *Declaration,
@@ -850,6 +883,34 @@ bool MatchASTVisitor::classIsDerivedFrom(const CXXRecordDecl *Declaration,
   return false;
 }
 
+// Returns true if the given Objective-C class is directly or indirectly
+// derived from a matching base class. A class is not considered to be derived
+// from itself.
+bool MatchASTVisitor::objcClassIsDerivedFrom(
+    const ObjCInterfaceDecl *Declaration, const Matcher<NamedDecl> &Base,
+    BoundNodesTreeBuilder *Builder, bool Directly) {
+  // Check if any of the superclasses of the class match.
+  for (const ObjCInterfaceDecl *ClassDecl = Declaration->getSuperClass();
+       ClassDecl != nullptr; ClassDecl = ClassDecl->getSuperClass()) {
+    // Check if there are any matching compatibility aliases.
+    if (objcClassHasMatchingCompatibilityAlias(ClassDecl, Base, Builder))
+      return true;
+
+    // Check if there are any matching type aliases.
+    const Type *TypeNode = ClassDecl->getTypeForDecl();
+    if (typeHasMatchingAlias(TypeNode, Base, Builder))
+      return true;
+
+    if (Base.matches(*ClassDecl, this, Builder))
+      return true;
+
+    if (Directly)
+      return false;
+  }
+
+  return false;
+}
+
 bool MatchASTVisitor::TraverseDecl(Decl *DeclNode) {
   if (!DeclNode) {
     return true;
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));
diff --git a/clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp b/clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp
index cf016a120b1..4e5c0ffe2b4 100644
--- a/clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp
+++ b/clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp
@@ -439,7 +439,7 @@ TEST_F(RegistryTest, Errors) {
       Error.get()).isNull());
   EXPECT_EQ("Incorrect type for arg 1. "
             "(Expected = Matcher<CXXRecordDecl>) != "
-            "(Actual = Matcher<CXXRecordDecl>&Matcher"
+            "(Actual = Matcher<CXXRecordDecl|ObjCInterfaceDecl>&Matcher"
             "<MemberExpr|UnresolvedMemberExpr|CXXDependentScopeMemberExpr>)",
             Error->toString());
 }