From 6e31a49931b8b057868a64e89838e3c9b40f9198 Mon Sep 17 00:00:00 2001
From: Michael Kruse <llvm-project@meinersbur.de>
Date: Mon, 6 May 2024 14:04:12 +0200
Subject: [PATCH] [driver] Do not warn about unused plugin flags. (#88948)

Plugins are not loaded without the -cc1 phase. Do not report them when
running on an assembly file or when linking. Many build tools add these
options to all driver invocations, including LLVM's build system.

Fixes #88173
---
 clang/include/clang/Driver/Options.td    | 6 +++---
 clang/test/Driver/plugin-driver-args.cpp | 5 +++++
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 938d5358eeda6b..c9f7c4e5f718b4 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -3663,14 +3663,14 @@ defm rwpi : BoolFOption<"rwpi",
           "Generate read-write position independent code (ARM only)">,
   NegFlag<SetFalse, [], [ClangOption, FlangOption, CC1Option]>>;
 def fplugin_EQ : Joined<["-"], "fplugin=">, Group<f_Group>,
-  Flags<[NoXarchOption]>, MetaVarName<"<dsopath>">,
+  Flags<[NoXarchOption, NoArgumentUnused]>, MetaVarName<"<dsopath>">,
   HelpText<"Load the named plugin (dynamic shared object)">;
 def fplugin_arg : Joined<["-"], "fplugin-arg-">,
-  MetaVarName<"<name>-<arg>">,
+  MetaVarName<"<name>-<arg>">, Flags<[NoArgumentUnused]>,
   HelpText<"Pass <arg> to plugin <name>">;
 def fpass_plugin_EQ : Joined<["-"], "fpass-plugin=">,
   Group<f_Group>, Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>,
-  MetaVarName<"<dsopath>">,
+  MetaVarName<"<dsopath>">, Flags<[NoArgumentUnused]>,
   HelpText<"Load pass plugin from a dynamic shared object file (only with new pass manager).">,
   MarshallingInfoStringVector<CodeGenOpts<"PassPlugins">>;
 defm tocdata : BoolOption<"m","tocdata",
diff --git a/clang/test/Driver/plugin-driver-args.cpp b/clang/test/Driver/plugin-driver-args.cpp
index d6475b4b3d733a..6f0e6e2ba75251 100644
--- a/clang/test/Driver/plugin-driver-args.cpp
+++ b/clang/test/Driver/plugin-driver-args.cpp
@@ -20,3 +20,8 @@
 
 // RUN: %clang -fplugin=%llvmshlibdir/CallSuperAttr%pluginext -fplugin-arg-testname- -fsyntax-only %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-PLUGIN-ARG2
 // CHECK-NO-PLUGIN-ARG2: missing plugin argument for plugin testname in -fplugin-arg-testname-
+
+// Plugins are only relevant for the -cc1 phase. No warning should be raised
+// when only using the assembler. See GH #88173.
+// RUN: %clang -c -fpass-plugin=bar.so -fplugin=bar.so -fplugin-arg-bar-option -Werror -x assembler %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-PLUGIN-ASM
+// CHECK-PLUGIN-ASM-NOT: argument unused during compilation