[clang] [Clang] Fix warning on device debugging when passing `-O0` (PR #175628)

[Joseph Huber via cfe-commits]

https://github.com/jhuber6 created https://github.com/llvm/llvm-project/pull/175628

Summary:
CUDA's Toolchain doesn't support debug information with optimizations,
so we warn on this. The logic was printing this even if you pass `-O0`
yourself. Also fix not passing `-g`.


>From ccd8fb67748ce9e47d7b61e7b6ee8b285d842163 Mon Sep 17 00:00:00 2001
From: Joseph Huber <huberjn at outlook.com>
Date: Mon, 12 Jan 2026 13:48:36 -0600
Subject: [PATCH] [Clang] Fix warning on device debugging when passing `-O0`

Summary:
CUDA's Toolchain doesn't support debug information with optimizations,
so we warn on this. The logic was printing this even if you pass `-O0`
yourself. Also fix not passing `-g`.
---
 clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp b/clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp
index a6c7a3affa97d..d944dcc1f3dbb 100644
--- a/clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp
+++ b/clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp
@@ -322,13 +322,15 @@ Expected<StringRef> runPTXAs(StringRef File, const ArgList &Args) {
   if (Args.hasArg(OPT_verbose))
     AssemblerArgs.push_back("-v");
   if (Args.hasArg(OPT_g)) {
-    if (Args.hasArg(OPT_O))
+    if (Args.getLastArgValue(OPT_O, "3"))
       WithColor::warning(errs(), Executable)
           << "Optimized debugging not supported, overriding to '-O0'\n";
     AssemblerArgs.push_back("-O0");
-  } else
+    AssemblerArgs.push_back("-g");
+  } else {
     AssemblerArgs.push_back(
         Args.MakeArgString("-O" + Args.getLastArgValue(OPT_O, "3")));
+  }
   AssemblerArgs.append({"-arch", Args.getLastArgValue(OPT_arch)});
   AssemblerArgs.append({"-o", *TempFileOrErr});