Fully implement the matcher for CXXCtorInitializer

[aaron.ballman]

Summary

It turns out that our support for the cxxCtorInitializer() matcher was incomplete in that it could not be used as a top-level matcher because it was not derived from one of the blessed base class types. This patch completes the support for this AST matcher.

[aaron.ballman]

Thanks! Commit in r282417

include/clang/ASTMatchers/ASTMatchFinder.h

                   MatchCallback *Action);
   void addMatcher(const TypeLocMatcher &NodeMatch,
                   MatchCallback *Action);
+  void addMatcher(const CXXCtorInitializerMatcher &NodeMatch,
+                  MatchCallback *Action);
   /// @}
 
   /// \brief Adds a matcher to execute when running over the AST.

     std::vector<std::pair<NestedNameSpecifierLocMatcher, MatchCallback *>>
         NestedNameSpecifierLoc;
     std::vector<std::pair<TypeLocMatcher, MatchCallback *>> TypeLoc;
+    std::vector<std::pair<CXXCtorInitializerMatcher, MatchCallback *>> CtorInit;
     /// \brief All the callbacks in one container to simplify iteration.
     llvm::SmallPtrSet<MatchCallback *, 16> AllCallbacks;
   };

include/clang/ASTMatchers/ASTMatchers.h

 typedef internal::Matcher<TypeLoc> TypeLocMatcher;
 typedef internal::Matcher<NestedNameSpecifier> NestedNameSpecifierMatcher;
 typedef internal::Matcher<NestedNameSpecifierLoc> NestedNameSpecifierLocMatcher;
+typedef internal::Matcher<CXXCtorInitializer> CXXCtorInitializerMatcher;
 /// @}
 
 /// \brief Matches any node.

lib/ASTMatchers/ASTMatchFinder.cpp

       traverse(*Q);
     else if (const TypeLoc *T = DynNode.get<TypeLoc>())
       traverse(*T);
+    else if (const auto *C = DynNode.get<CXXCtorInitializer>())
+      traverse(*C);
     // FIXME: Add other base types after adding tests.
 
     // It's OK to always overwrite the bound nodes, as if there was

       return false;
     return traverse(NNS);
   }
+  bool TraverseConstructorInitializer(CXXCtorInitializer *CtorInit) {
+    if (!CtorInit)
+      return true;
+    ScopedIncrement ScopedDepth(&CurrentDepth);
+    return traverse(*CtorInit);
+  }
 
   bool shouldVisitTemplateInstantiations() const { return true; }
   bool shouldVisitImplicitCode() const { return true; }

   bool baseTraverse(NestedNameSpecifierLoc NNS) {
     return VisitorBase::TraverseNestedNameSpecifierLoc(NNS);
   }
+  bool baseTraverse(const CXXCtorInitializer &CtorInit) {
+    return VisitorBase::TraverseConstructorInitializer(
+        const_cast<CXXCtorInitializer *>(&CtorInit));
+  }
 
   // Sets 'Matched' to true if 'Matcher' matches 'Node' and:
   //   0 < CurrentDepth <= MaxDepth.

   bool TraverseTypeLoc(TypeLoc TypeNode);
   bool TraverseNestedNameSpecifier(NestedNameSpecifier *NNS);
   bool TraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS);
+  bool TraverseConstructorInitializer(CXXCtorInitializer *CtorInit);
 
   // Matches children or descendants of 'Node' with 'BaseMatcher'.
   bool memoizedMatchesRecursively(const ast_type_traits::DynTypedNode &Node,

       match(*N);
     } else if (auto *N = Node.get<TypeLoc>()) {
       match(*N);
+    } else if (auto *N = Node.get<CXXCtorInitializer>()) {
+      match(*N);
     }
   }
 

   void matchDispatch(const NestedNameSpecifierLoc *Node) {
     matchWithoutFilter(*Node, Matchers->NestedNameSpecifierLoc);
   }
+  void matchDispatch(const CXXCtorInitializer *Node) {
+    matchWithoutFilter(*Node, Matchers->CtorInit);
+  }
   void matchDispatch(const void *) { /* Do nothing. */ }
   /// @}
 

       RecursiveASTVisitor<MatchASTVisitor>::TraverseNestedNameSpecifierLoc(NNS);
 }
 
+bool MatchASTVisitor::TraverseConstructorInitializer(
+    CXXCtorInitializer *CtorInit) {
+  if (!CtorInit)
+    return true;
+
+  match(*CtorInit);
+
+  return RecursiveASTVisitor<MatchASTVisitor>::TraverseConstructorInitializer(
+      CtorInit);
+}
+
 class MatchASTConsumer : public ASTConsumer {
 public:
   MatchASTConsumer(MatchFinder *Finder,

   Matchers.AllCallbacks.insert(Action);
 }
 
+void MatchFinder::addMatcher(const CXXCtorInitializerMatcher &NodeMatch,
+                             MatchCallback *Action) {
+  Matchers.CtorInit.emplace_back(NodeMatch, Action);
+  Matchers.AllCallbacks.insert(Action);
+}
+
 bool MatchFinder::addDynamicMatcher(const internal::DynTypedMatcher &NodeMatch,
                                     MatchCallback *Action) {
   if (NodeMatch.canConvertTo<Decl>()) {

   } else if (NodeMatch.canConvertTo<TypeLoc>()) {
     addMatcher(NodeMatch.convertTo<TypeLoc>(), Action);
     return true;
+  } else if (NodeMatch.canConvertTo<CXXCtorInitializer>()) {
+    addMatcher(NodeMatch.convertTo<CXXCtorInitializer>(), Action);
+    return true;
   }
   return false;
 }

unittests/ASTMatchers/ASTMatchersNodeTest.cpp

   EXPECT_TRUE(matches("class X {}; void x(int) { X x; }", Constructor));
 }
 
+TEST(Match, ConstructorInitializers) {
+  EXPECT_TRUE(matches("class C { int i; public: C(int ii) : i(ii) {} };",
+                      cxxCtorInitializer(forField(hasName("i")))));
+}
+
 TEST(Matcher, ThisExpr) {
   EXPECT_TRUE(
     matches("struct X { int a; int f () { return a; } };", cxxThisExpr()));