[clang] [Clang] accept @tparam on variable template partial specializations (PR #147219)

[Oleksandr T. via cfe-commits]

https://github.com/a-tarasyuk created https://github.com/llvm/llvm-project/pull/147219

Fixes #144775

--- 

This patch addresses a false-positive `-Wdocumentation` warning on `@tparam` comments attached to _variable template partial specializations_

>From 2c44c8bd3c2a49ba0a2cecdcadf5d08c0e9e3108 Mon Sep 17 00:00:00 2001
From: Oleksandr Tarasiuk <oleksandr.tarasiuk at outlook.com>
Date: Mon, 7 Jul 2025 02:40:43 +0300
Subject: [PATCH] [Clang] accept @tparam on variable template partial
 specializations

---
 clang/docs/ReleaseNotes.rst            |  2 ++
 clang/lib/AST/Comment.cpp              |  7 +++++++
 clang/test/Sema/warn-documentation.cpp | 12 ++++++++++++
 3 files changed, 21 insertions(+)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 9a94c4bcd9980..d85c592b6d8bc 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -671,6 +671,8 @@ Improvements to Clang's diagnostics
   false positives in exception-heavy code, though only simple patterns
   are currently recognized.
 
+- Clang now accepts ``@tparam`` comments on variable template partial
+  specializations. (#GH144775)
 
 Improvements to Clang's time-trace
 ----------------------------------
diff --git a/clang/lib/AST/Comment.cpp b/clang/lib/AST/Comment.cpp
index d022c5c845ae6..9fd4cc942e7b7 100644
--- a/clang/lib/AST/Comment.cpp
+++ b/clang/lib/AST/Comment.cpp
@@ -291,6 +291,13 @@ void DeclInfo::fill() {
     TemplateParameters = CTPSD->getTemplateParameters();
     break;
   }
+  case Decl::VarTemplatePartialSpecialization: {
+    const VarTemplatePartialSpecializationDecl *VTPSD = cast<VarTemplatePartialSpecializationDecl>(CommentDecl);
+    Kind = VariableKind;
+    TemplateKind = TemplatePartialSpecialization;
+    TemplateParameters = VTPSD->getTemplateParameters();
+    break;
+  }
   case Decl::ClassTemplateSpecialization:
     Kind = ClassKind;
     TemplateKind = TemplateSpecialization;
diff --git a/clang/test/Sema/warn-documentation.cpp b/clang/test/Sema/warn-documentation.cpp
index 4839bdff61795..0d1faa1b562fe 100644
--- a/clang/test/Sema/warn-documentation.cpp
+++ b/clang/test/Sema/warn-documentation.cpp
@@ -1524,3 +1524,15 @@ F &f = FF; ///< \return none
 // expected-warning at -1 {{'\return' command used in a comment that is not attached to a function or method declaration}}
 
 } // namespace PR42844
+
+#if __cplusplus >= 201402L
+namespace GH144775 {
+/// @brief primary template
+/// @tparam T type
+template <class T, class = void> constexpr auto var = T{};
+
+/// @brief variable template partial specialization
+/// @tparam T type
+template <typename T> constexpr auto var<T> = T{};
+} // namespace GH144775
+#endif