[Clang][ASTMatcher] Add dependentNameType AST matcher (#121263)

Fixes: #121240

Author: AmrDeveloper

clang/docs/LibASTMatchersReference.html

@@ -2536,6 +2536,15 @@ <h2 id="decl-matchers">Node Matchers</h2>
   matches "decltype(i + j)"
 </pre></td></tr>
 
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Type.html">Type</a>&gt;</td><td class="name" onclick="toggle('dependentNameType0')"><a name="dependentNameType0Anchor">dependentNameType</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1DependentNameType.html">DependentNameType</a>&gt;...</td></tr>
+<tr><td colspan="4" class="doc" id="dependentNameType0"><pre>Matches a dependent name type.
+
+Example matches T::type
+
+  template <typename T> struct declToImport {
+    typedef typename T::type dependent_name;
+  };
+</pre></td></tr>
 
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Type.html">Type</a>&gt;</td><td class="name" onclick="toggle('deducedTemplateSpecializationType0')"><a name="deducedTemplateSpecializationType0Anchor">deducedTemplateSpecializationType</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1DeducedTemplateSpecializationType.html">DeducedTemplateSpecializationType</a>&gt;...</td></tr>
 <tr><td colspan="4" class="doc" id="deducedTemplateSpecializationType0"><pre>Matches C++17 deduced template specialization types, e.g. deduced class

clang/docs/ReleaseNotes.rst

@@ -1110,6 +1110,8 @@ AST Matchers
 
 - Add ``dependentScopeDeclRefExpr`` matcher to match expressions that refer to dependent scope declarations.
 
+- Add ``dependentNameType`` matcher to match a dependent name type.
+
 clang-format
 ------------
 

clang/include/clang/ASTMatchers/ASTMatchers.h

@@ -7711,6 +7711,16 @@ AST_MATCHER_P(DecayedType, hasDecayedType, internal::Matcher<QualType>,
   return InnerType.matches(Node.getDecayedType(), Finder, Builder);
 }
 
+/// Matches a dependent name type
+///
+/// Example matches  T::type
+/// \code
+///  template <typename T> struct declToImport {
+///    typedef typename T::type dependent_name;
+///  };
+/// \endcode
+extern const AstTypeMatcher<DependentNameType> dependentNameType;
+
 /// Matches declarations whose declaration context, interpreted as a
 /// Decl, matches \c InnerMatcher.
 ///

clang/lib/ASTMatchers/ASTMatchersInternal.cpp

@@ -1108,6 +1108,7 @@ const AstTypeMatcher<SubstTemplateTypeParmType> substTemplateTypeParmType;
 const AstTypeMatcher<TemplateTypeParmType> templateTypeParmType;
 const AstTypeMatcher<InjectedClassNameType> injectedClassNameType;
 const AstTypeMatcher<DecayedType> decayedType;
+const AstTypeMatcher<DependentNameType> dependentNameType;
 AST_TYPELOC_TRAVERSE_MATCHER_DEF(hasElementType,
                                  AST_POLYMORPHIC_SUPPORTED_TYPES(ArrayType,
                                                                  ComplexType));

clang/lib/ASTMatchers/Dynamic/Registry.cpp

@@ -222,6 +222,7 @@ RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(decompositionDecl);
   REGISTER_MATCHER(declCountIs);
   REGISTER_MATCHER(declRefExpr);
+  REGISTER_MATCHER(dependentNameType);
   REGISTER_MATCHER(dependentScopeDeclRefExpr);
   REGISTER_MATCHER(declStmt);
   REGISTER_MATCHER(declaratorDecl);

clang/unittests/AST/ASTImporterTest.cpp

@@ -3196,9 +3196,6 @@ TEST_P(ImportExpr, DependentScopeDeclRefExpr) {
                  has(callExpr(has(dependentScopeDeclRefExpr())))))))));
 }
 
-const internal::VariadicDynCastAllOfMatcher<Type, DependentNameType>
-    dependentNameType;
-
 TEST_P(ImportExpr, DependentNameType) {
   MatchVerifier<Decl> Verifier;
   testImport("template <typename T> struct declToImport {"

clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp

@@ -1912,6 +1912,20 @@ TEST_P(ASTMatchersTest, DeducedTemplateSpecializationType) {
               deducedTemplateSpecializationType()));
 }
 
+TEST_P(ASTMatchersTest, DependentNameType) {
+  if (!GetParam().isCXX()) {
+    return;
+  }
+
+  EXPECT_TRUE(matches(
+      R"(
+        template <typename T> struct declToImport {
+          typedef typename T::type dependent_name;
+        };
+      )",
+      dependentNameType()));
+}
+
 TEST_P(ASTMatchersTest, RecordType) {
   EXPECT_TRUE(matches("struct S {}; struct S s;",
                       recordType(hasDeclaration(recordDecl(hasName("S"))))));