[clang] [clang][CUDA] Perform lvalue-to-rvalue conversion on `__cluster_dims__` attribute (PR #227998)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr updated https://github.com/llvm/llvm-project/pull/227998

>From e62dc6663b5937a472beca8ed81b019b2c0e42f7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Tue, 6 Oct 2026 08:11:02 +0200
Subject: [PATCH] rvalue

---
 clang/lib/Sema/SemaDeclAttr.cpp | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index eb4a8c2ab9ae0..3fce8589739cd 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -6261,9 +6261,19 @@ static void handleClusterDimsAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
       !AL.checkAtMostNumArgs(S, /*Num=*/3))
     return;
 
-  S.addClusterDimsAttr(D, AL, AL.getArgAsExpr(0),
-                       AL.getNumArgs() > 1 ? AL.getArgAsExpr(1) : nullptr,
-                       AL.getNumArgs() > 2 ? AL.getArgAsExpr(2) : nullptr);
+  // Convert all arguments to rvalues.
+  ExprResult Converted1 = S.DefaultLvalueConversion(AL.getArgAsExpr(0));
+  assert(!Converted1.isInvalid());
+  ExprResult Converted2 = AL.getNumArgs() > 1
+                              ? S.DefaultLvalueConversion(AL.getArgAsExpr(1))
+                              : ExprResult();
+  ExprResult Converted3 = AL.getNumArgs() > 2
+                              ? S.DefaultLvalueConversion(AL.getArgAsExpr(2))
+                              : ExprResult();
+
+  S.addClusterDimsAttr(D, AL, Converted1.get(),
+                       Converted2.isInvalid() ? nullptr : Converted2.get(),
+                       Converted3.isInvalid() ? nullptr : Converted3.get());
 }
 
 static void handleNoClusterAttr(Sema &S, Decl *D, const ParsedAttr &AL) {