[clang] Add isDirectlyDerivedFrom AST matcher.

Differential Revision: https://reviews.llvm.org/D65092

llvm-svn: 367010

clang/docs/LibASTMatchersReference.html

@@ -2581,6 +2581,11 @@ <h2 id="narrowing-matchers">Narrowing Matchers</h2>
 </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(...)).
+</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('isExplicitTemplateSpecialization2')"><a name="isExplicitTemplateSpecialization2Anchor">isExplicitTemplateSpecialization</a></td><td></td></tr>
 <tr><td colspan="4" class="doc" id="isExplicitTemplateSpecialization2"><pre>Matches explicit template specializations of function, class, or
 static member variable template instantiations.
@@ -5263,6 +5268,26 @@ <h2 id="traversal-matchers">AST Traversal Matchers</h2>
 </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.
+
+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_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;</td><td class="name" onclick="toggle('isSameOrDerivedFrom0')"><a name="isSameOrDerivedFrom0Anchor">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="isSameOrDerivedFrom0"><pre>Similar to isDerivedFrom(), but also matches classes that directly
 match Base.

clang/include/clang/ASTMatchers/ASTMatchers.h

@@ -2634,7 +2634,7 @@ hasOverloadedOperatorName(StringRef Name) {
 /// \endcode
 AST_MATCHER_P(CXXRecordDecl, isDerivedFrom,
               internal::Matcher<NamedDecl>, Base) {
-  return Finder->classIsDerivedFrom(&Node, Base, Builder);
+  return Finder->classIsDerivedFrom(&Node, Base, Builder, /*Directly=*/false);
 }
 
 /// Overloaded method as shortcut for \c isDerivedFrom(hasName(...)).
@@ -2659,6 +2659,38 @@ AST_MATCHER_P_OVERLOAD(CXXRecordDecl, isSameOrDerivedFrom, std::string,
   return isSameOrDerivedFrom(hasName(BaseName)).matches(Node, Finder, Builder);
 }
 
+/// Matches C++ classes that are directly derived from a class matching \c Base.
+///
+/// Note that a class is not considered to be derived from itself.
+///
+/// Example matches Y, C (Base == hasName("X"))
+/// \code
+///   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
+/// \endcode
+///
+/// In the following example, Bar matches isDerivedFrom(hasName("X")):
+/// \code
+///   class Foo;
+///   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);
+}
+
+/// Overloaded method as shortcut for \c isDirectlyDerivedFrom(hasName(...)).
+AST_MATCHER_P_OVERLOAD(CXXRecordDecl, isDirectlyDerivedFrom, std::string,
+                       BaseName, 1) {
+  assert(!BaseName.empty());
+  return isDirectlyDerivedFrom(hasName(BaseName))
+      .matches(Node, Finder, Builder);
+}
 /// Matches the first method of a class or struct that satisfies \c
 /// InnerMatcher.
 ///

clang/include/clang/ASTMatchers/ASTMatchersInternal.h

@@ -974,10 +974,11 @@ class ASTMatchFinder {
   /// Returns true if the given class is directly or indirectly derived
   /// from a base type matching \c base.
   ///
-  /// A class is considered to be also derived from itself.
+  /// A class is not considered to be derived from itself.
   virtual bool classIsDerivedFrom(const CXXRecordDecl *Declaration,
                                   const Matcher<NamedDecl> &Base,
-                                  BoundNodesTreeBuilder *Builder) = 0;
+                                  BoundNodesTreeBuilder *Builder,
+                                  bool Directly) = 0;
 
   template <typename T>
   bool matchesChildOf(const T &Node, const DynTypedMatcher &Matcher,

clang/lib/ASTMatchers/ASTMatchFinder.cpp

@@ -430,7 +430,8 @@ class MatchASTVisitor : public RecursiveASTVisitor<MatchASTVisitor>,
 
   bool classIsDerivedFrom(const CXXRecordDecl *Declaration,
                           const Matcher<NamedDecl> &Base,
-                          BoundNodesTreeBuilder *Builder) override;
+                          BoundNodesTreeBuilder *Builder,
+                          bool Directly) override;
 
   // Implements ASTMatchFinder::matchesChildOf.
   bool matchesChildOf(const ast_type_traits::DynTypedNode &Node,
@@ -817,7 +818,8 @@ getAsCXXRecordDeclOrPrimaryTemplate(const Type *TypeNode) {
 // derived from itself.
 bool MatchASTVisitor::classIsDerivedFrom(const CXXRecordDecl *Declaration,
                                          const Matcher<NamedDecl> &Base,
-                                         BoundNodesTreeBuilder *Builder) {
+                                         BoundNodesTreeBuilder *Builder,
+                                         bool Directly) {
   if (!Declaration->hasDefinition())
     return false;
   for (const auto &It : Declaration->bases()) {
@@ -842,7 +844,7 @@ bool MatchASTVisitor::classIsDerivedFrom(const CXXRecordDecl *Declaration,
       *Builder = std::move(Result);
       return true;
     }
-    if (classIsDerivedFrom(ClassDecl, Base, Builder))
+    if (!Directly && classIsDerivedFrom(ClassDecl, Base, Builder, Directly))
       return true;
   }
   return false;

clang/lib/ASTMatchers/Dynamic/Registry.cpp

@@ -108,6 +108,7 @@ RegistryMaps::RegistryMaps() {
   REGISTER_OVERLOADED_2(hasType);
   REGISTER_OVERLOADED_2(ignoringParens);
   REGISTER_OVERLOADED_2(isDerivedFrom);
+  REGISTER_OVERLOADED_2(isDirectlyDerivedFrom);
   REGISTER_OVERLOADED_2(isSameOrDerivedFrom);
   REGISTER_OVERLOADED_2(loc);
   REGISTER_OVERLOADED_2(pointsTo);

clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp

@@ -331,6 +331,16 @@ TEST(DeclarationMatcher, ClassIsDerived) {
   EXPECT_TRUE(notMatches("class Y;", IsDerivedFromX));
   EXPECT_TRUE(notMatches("", IsDerivedFromX));
 
+  DeclarationMatcher IsDirectlyDerivedFromX =
+      cxxRecordDecl(isDirectlyDerivedFrom("X"));
+
+  EXPECT_TRUE(
+      matches("class X {}; class Y : public X {};", IsDirectlyDerivedFromX));
+  EXPECT_TRUE(notMatches("class X {};", IsDirectlyDerivedFromX));
+  EXPECT_TRUE(notMatches("class X;", IsDirectlyDerivedFromX));
+  EXPECT_TRUE(notMatches("class Y;", IsDirectlyDerivedFromX));
+  EXPECT_TRUE(notMatches("", IsDirectlyDerivedFromX));
+
   DeclarationMatcher IsAX = cxxRecordDecl(isSameOrDerivedFrom("X"));
 
   EXPECT_TRUE(matches("class X {}; class Y : public X {};", IsAX));
@@ -341,13 +351,22 @@ TEST(DeclarationMatcher, ClassIsDerived) {
 
   DeclarationMatcher ZIsDerivedFromX =
     cxxRecordDecl(hasName("Z"), isDerivedFrom("X"));
+  DeclarationMatcher ZIsDirectlyDerivedFromX =
+      cxxRecordDecl(hasName("Z"), isDirectlyDerivedFrom("X"));
   EXPECT_TRUE(
     matches("class X {}; class Y : public X {}; class Z : public Y {};",
             ZIsDerivedFromX));
+  EXPECT_TRUE(
+      notMatches("class X {}; class Y : public X {}; class Z : public Y {};",
+                 ZIsDirectlyDerivedFromX));
   EXPECT_TRUE(
     matches("class X {};"
               "template<class T> class Y : public X {};"
               "class Z : public Y<int> {};", ZIsDerivedFromX));
+  EXPECT_TRUE(notMatches("class X {};"
+                         "template<class T> class Y : public X {};"
+                         "class Z : public Y<int> {};",
+                         ZIsDirectlyDerivedFromX));
   EXPECT_TRUE(matches("class X {}; template<class T> class Z : public X {};",
                       ZIsDerivedFromX));
   EXPECT_TRUE(
@@ -411,6 +430,9 @@ TEST(DeclarationMatcher, ClassIsDerived) {
     matches("class X {}; class Y : public X {}; "
               "typedef Y V; typedef V W; class Z : public W {};",
             ZIsDerivedFromX));
+  EXPECT_TRUE(notMatches("class X {}; class Y : public X {}; "
+                         "typedef Y V; typedef V W; class Z : public W {};",
+                         ZIsDirectlyDerivedFromX));
   EXPECT_TRUE(
     matches("template<class T, class U> class X {}; "
               "template<class T> class A { class Z : public X<T, int> {}; };",
@@ -467,6 +489,14 @@ TEST(DeclarationMatcher, ClassIsDerived) {
       "template<> struct X<0> : public A {};"
       "struct B : public X<42> {};",
     cxxRecordDecl(hasName("B"), isDerivedFrom(recordDecl(hasName("A"))))));
+  EXPECT_TRUE(notMatches(
+      "struct A {};"
+      "template<int> struct X;"
+      "template<int i> struct X : public X<i-1> {};"
+      "template<> struct X<0> : public A {};"
+      "struct B : public X<42> {};",
+      cxxRecordDecl(hasName("B"),
+                    isDirectlyDerivedFrom(recordDecl(hasName("A"))))));
 
   // FIXME: Once we have better matchers for template type matching,
   // get rid of the Variable(...) matching and match the right template