[clang] [NvlinkWrapper] Use `-plugin-opt=mattr=` instead of a custom feature (PR #111712)

[Joseph Huber via cfe-commits]

https://github.com/jhuber6 created https://github.com/llvm/llvm-project/pull/111712

Summary:
We don't need a custom flag for this, LLVM had a way to get the features
which are forwarded via `plugin-opt`.


>From 6135a70a45801783a770252e765773905f18313d Mon Sep 17 00:00:00 2001
From: Joseph Huber <huberjn at outlook.com>
Date: Wed, 9 Oct 2024 11:42:55 -0500
Subject: [PATCH] [NvlinkWrapper] Use `-plugin-opt=mattr=` instead of a custom
 feature

Summary:
We don't need a custom flag for this, LLVM had a way to get the features
which are forwarded via `plugin-opt`.
---
 clang/lib/Driver/ToolChains/Cuda.cpp                    | 4 ++--
 clang/test/Driver/cuda-cross-compiling.c                | 2 +-
 clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp | 2 +-
 clang/tools/clang-nvlink-wrapper/NVLinkOpts.td          | 3 ---
 4 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/clang/lib/Driver/ToolChains/Cuda.cpp b/clang/lib/Driver/ToolChains/Cuda.cpp
index 509cd87b28c37e..dfcd20a73f1d54 100644
--- a/clang/lib/Driver/ToolChains/Cuda.cpp
+++ b/clang/lib/Driver/ToolChains/Cuda.cpp
@@ -632,8 +632,8 @@ void NVPTX::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   std::vector<StringRef> Features;
   getNVPTXTargetFeatures(C.getDriver(), getToolChain().getTriple(), Args,
                          Features);
-  for (StringRef Feature : Features)
-    CmdArgs.append({"--feature", Args.MakeArgString(Feature)});
+  CmdArgs.push_back(
+      Args.MakeArgString("--plugin-opt=mattr=" + llvm::join(Features, ",")));
 
   // Add paths for the default clang library path.
   SmallString<256> DefaultLibPath =
diff --git a/clang/test/Driver/cuda-cross-compiling.c b/clang/test/Driver/cuda-cross-compiling.c
index 5f24e7a5accb08..54c291fac66ffd 100644
--- a/clang/test/Driver/cuda-cross-compiling.c
+++ b/clang/test/Driver/cuda-cross-compiling.c
@@ -104,4 +104,4 @@
 // RUN: %clang -target nvptx64-nvidia-cuda --cuda-feature=+ptx63 -march=sm_52 -### %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=FEATURE %s
 
-// FEATURE: clang-nvlink-wrapper{{.*}}"--feature" "+ptx63"
+// FEATURE: clang-nvlink-wrapper{{.*}}"--plugin-opt=mattr=+ptx63"
diff --git a/clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp b/clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp
index b4b376fe0d114e..b9767a7a03d0b5 100644
--- a/clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp
+++ b/clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp
@@ -344,7 +344,7 @@ Expected<std::unique_ptr<lto::LTO>> createLTO(const ArgList &Args) {
   Conf.RemarksHotnessThreshold = RemarksHotnessThreshold;
   Conf.RemarksFormat = RemarksFormat;
 
-  Conf.MAttrs = {Args.getLastArgValue(OPT_feature, "").str()};
+  Conf.MAttrs = llvm::codegen::getMAttrs();
   std::optional<CodeGenOptLevel> CGOptLevelOrNone =
       CodeGenOpt::parseLevel(Args.getLastArgValue(OPT_O, "2")[0]);
   assert(CGOptLevelOrNone && "Invalid optimization level");
diff --git a/clang/tools/clang-nvlink-wrapper/NVLinkOpts.td b/clang/tools/clang-nvlink-wrapper/NVLinkOpts.td
index eeb9d1a6228240..a80c5937b42992 100644
--- a/clang/tools/clang-nvlink-wrapper/NVLinkOpts.td
+++ b/clang/tools/clang-nvlink-wrapper/NVLinkOpts.td
@@ -47,9 +47,6 @@ def arch : Separate<["--", "-"], "arch">,
 def : Joined<["--", "-"], "plugin-opt=mcpu=">,
   Flags<[HelpHidden, WrapperOnlyOption]>, Alias<arch>;
 
-def feature : Separate<["--", "-"], "feature">, Flags<[WrapperOnlyOption]>,
-  HelpText<"Specify the '+ptx' freature to use for LTO.">;
-
 def g : Flag<["-"], "g">, HelpText<"Specify that this was a debug compile.">;
 def debug : Flag<["--"], "debug">, Alias<g>;