[llvm-branch-commits] [clang-tools-extra] release/22.x: Backport workarounds for certain addMatcher overloads ignoring traversal kind (PR #187274)

[Victor Chernyakin via llvm-branch-commits]

https://github.com/localspook created https://github.com/llvm/llvm-project/pull/187274

Backporting #184039 was considered too risky, so this PR is a more conservative second attempt.

>From 9ffb81f5a8fd69f5d20816ae51067db64835c42f Mon Sep 17 00:00:00 2001
From: Victor Chernyakin <chernyakin.victor.j at outlook.com>
Date: Wed, 18 Mar 2026 06:49:44 -0700
Subject: [PATCH] release/22.x: Backport workarounds for certain addMatcher
 overloads ignoring traversal kind

---
 .../clang-tidy/modernize/TypeTraitsCheck.cpp       |  4 +++-
 .../readability/RedundantTypenameCheck.cpp         |  2 +-
 .../clang-tidy/checkers/modernize/type-traits.cpp  | 14 ++++++++++++++
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/modernize/TypeTraitsCheck.cpp b/clang-tools-extra/clang-tidy/modernize/TypeTraitsCheck.cpp
index 0d03006750d07..eadd3f15c6fde 100644
--- a/clang-tools-extra/clang-tidy/modernize/TypeTraitsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/TypeTraitsCheck.cpp
@@ -195,7 +195,9 @@ void TypeTraitsCheck::registerMatchers(MatchFinder *Finder) {
                            .bind(Bind),
                        this);
   }
-  Finder->addMatcher(typeLoc(isType()).bind(Bind), this);
+  Finder->addMatcher(
+      traverse(TK_IgnoreUnlessSpelledInSource, typeLoc(isType()).bind(Bind)),
+      this);
 }
 
 static bool isNamedDeclInStdTraitsSet(const NamedDecl *ND,
diff --git a/clang-tools-extra/clang-tidy/readability/RedundantTypenameCheck.cpp b/clang-tools-extra/clang-tidy/readability/RedundantTypenameCheck.cpp
index 01f9177c248ac..525725cade624 100644
--- a/clang-tools-extra/clang-tidy/readability/RedundantTypenameCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/RedundantTypenameCheck.cpp
@@ -19,7 +19,7 @@ namespace clang::tidy::readability {
 
 void RedundantTypenameCheck::registerMatchers(MatchFinder *Finder) {
   Finder->addMatcher(
-      typeLoc(unless(hasAncestor(decl(isInstantiated())))).bind("typeLoc"),
+      traverse(TK_IgnoreUnlessSpelledInSource, typeLoc().bind("typeLoc")),
       this);
 
   if (!getLangOpts().CPlusPlus20)
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/type-traits.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/type-traits.cpp
index e5de9e33bccd9..2b2c8e97c3d3b 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/modernize/type-traits.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/type-traits.cpp
@@ -150,3 +150,17 @@ struct ImplicitlyInstantiatedConstructor {
 const ImplicitlyInstantiatedConstructor<int> ImplicitInstantiation(std::remove_reference<int>::type(123));
 // CHECK-MESSAGES: :[[@LINE-1]]:68: warning: use c++14 style type templates
 // CHECK-FIXES: const ImplicitlyInstantiatedConstructor<int> ImplicitInstantiation(std::remove_reference_t<int>(123));
+
+#if __cplusplus >= 202002L
+
+template <typename T>
+struct S {
+  typename std::remove_reference<T>::type a; // NOLINT
+};
+
+void f() {
+  auto [a] = S<int>{};
+  [&] { a; }; // This used to cause a false positive.
+}
+
+#endif // __cplusplus >= 202002L