[clang] [Clang][ASTMatcher] Add a matcher for the name of a DependentScopeDeclRefExpr (PR #121656)

[Amr Hesham via cfe-commits]

https://github.com/AmrDeveloper created https://github.com/llvm/llvm-project/pull/121656

Add the `hasDependentName` matcher to match the name of `DependentScopeDeclRefExpr`

Example: `dependentScopeDeclRefExpr(hasDependentName("name"))`

Fixes: #121610

>From 4cd48886384570e0e5bb0b712f4fd45f8decd27e Mon Sep 17 00:00:00 2001
From: AmrDeveloper <amr96 at programmer.net>
Date: Sat, 4 Jan 2025 17:36:05 +0100
Subject: [PATCH] [Clang][ASTMatcher] Add a matcher for the name of a
 DependentScopeDeclRefExpr

---
 clang/docs/LibASTMatchersReference.html           | 13 +++++++++++++
 clang/docs/ReleaseNotes.rst                       |  2 ++
 clang/include/clang/ASTMatchers/ASTMatchers.h     | 11 +++++++++++
 clang/lib/ASTMatchers/Dynamic/Registry.cpp        |  1 +
 .../ASTMatchers/ASTMatchersNarrowingTest.cpp      | 15 +++++++++++++++
 5 files changed, 42 insertions(+)

diff --git a/clang/docs/LibASTMatchersReference.html b/clang/docs/LibASTMatchersReference.html
index fc557888013254..6a03aeb5eec2a1 100644
--- a/clang/docs/LibASTMatchersReference.html
+++ b/clang/docs/LibASTMatchersReference.html
@@ -3449,6 +3449,19 @@ <h2 id="narrowing-matchers">Narrowing Matchers</h2>
 </pre></td></tr>
 
 
+<tr><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1DependentScopeDeclRefExpr.html">DependentScopeDeclRefExpr</a>></td><td class="name" onclick="toggle('hasDependentName0')"><a name="hasDependentName0Anchor">hasDependentName</a></td><td>std::string N</td></tr>
+<tr><td colspan="4" class="doc" id="hasDependentName0"><pre>Matches the dependent name of a dependent scope decl ref expr.
+
+Matches the dependent name of a dependent scope decl ref expr
+
+Given:
+
+  template <class T< class X : T { void f() { T::v; } };
+
+dependentScopeDeclRefExpr(hasDependentName("v")) matches `T::v`
+</pre></td></tr>
+
+
 <tr><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXDependentScopeMemberExpr.html">CXXDependentScopeMemberExpr</a>></td><td class="name" onclick="toggle('memberHasSameNameAsBoundNode0')"><a name="memberHasSameNameAsBoundNode0Anchor">memberHasSameNameAsBoundNode</a></td><td>std::string BindingID</td></tr>
 <tr><td colspan="4" class="doc" id="memberHasSameNameAsBoundNode0"><pre>Matches template-dependent, but known, member names against an already-bound
 node
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 5e75fc447636e0..4ef69ca4c743ed 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -1116,6 +1116,8 @@ AST Matchers
 
 - Add ``dependentTemplateSpecializationType`` matcher to match a dependent template specialization type.
 
+- Add ``hasDependentName`` matcher to match the dependent name of a dependent scope decl ref expr.
+
 clang-format
 ------------
 
diff --git a/clang/include/clang/ASTMatchers/ASTMatchers.h b/clang/include/clang/ASTMatchers/ASTMatchers.h
index dd0fedb2cda2d4..6828fc6da1d5cf 100644
--- a/clang/include/clang/ASTMatchers/ASTMatchers.h
+++ b/clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -3257,6 +3257,17 @@ AST_MATCHER_P(CXXDependentScopeMemberExpr, memberHasSameNameAsBoundNode,
       });
 }
 
+/// Matches the dependent name of a dependent scope decl ref expr
+///
+/// Given:
+/// \code
+///  template <class T> class X : T { void f() { T::v; } };
+/// \endcode
+/// \c dependentScopeDeclRefExpr(hasDependentName("v")) matches `T::v`
+AST_MATCHER_P(DependentScopeDeclRefExpr, hasDependentName, std::string, N) {
+  return Node.getDeclName().getAsString() == N;
+}
+
 /// 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.
diff --git a/clang/lib/ASTMatchers/Dynamic/Registry.cpp b/clang/lib/ASTMatchers/Dynamic/Registry.cpp
index 97e6bbc093fe46..336d3a14f79559 100644
--- a/clang/lib/ASTMatchers/Dynamic/Registry.cpp
+++ b/clang/lib/ASTMatchers/Dynamic/Registry.cpp
@@ -314,6 +314,7 @@ RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(hasDeducedType);
   REGISTER_MATCHER(hasDefaultArgument);
   REGISTER_MATCHER(hasDefinition);
+  REGISTER_MATCHER(hasDependentName);
   REGISTER_MATCHER(hasDescendant);
   REGISTER_MATCHER(hasDestinationType);
   REGISTER_MATCHER(hasDirectBase);
diff --git a/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
index 056b7c7b571ef4..4278e3d4fe5959 100644
--- a/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
+++ b/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
@@ -2235,6 +2235,21 @@ TEST_P(ASTMatchersTest, ArgumentCountIs_CXXConstructExpr) {
                  Constructor1Arg));
 }
 
+TEST_P(ASTMatchersTest, hasDependentName_DependentScopeDeclRefExpr) {
+  if (!GetParam().isCXX() || GetParam().hasDelayedTemplateParsing()) {
+    // FIXME: Fix this test to work with delayed template parsing.
+    return;
+  }
+
+  EXPECT_TRUE(matches("template <class T> class X : T { void f() { T::v; } };",
+                      dependentScopeDeclRefExpr(hasDependentName("v"))));
+
+  EXPECT_TRUE(
+      matches("template <typename T> struct S { static T Foo; };"
+              "template <typename T> void declToImport() { (void)S<T>::Foo; }",
+              dependentScopeDeclRefExpr(hasDependentName("Foo"))));
+}
+
 TEST(ASTMatchersTest, NamesMember_CXXDependentScopeMemberExpr) {
 
   // Member functions: