[clang] [KeyInstr][Clang][NFC] Don't set -dwarf-use-key-instructions (PR #144115)

[Orlando Cazalet-Hyams via cfe-commits]

https://github.com/OCHyams created https://github.com/llvm/llvm-project/pull/144115

Once #144104 lands the flag is true by default (because each DISubprogram will track whether or not it's using key instructions).

>From 748d6d5a7c53b21e6fe1170a8c0793e91196a507 Mon Sep 17 00:00:00 2001
From: Orlando Cazalet-Hyams <orlando.hyams at sony.com>
Date: Fri, 13 Jun 2025 17:39:53 +0100
Subject: [PATCH] [KeyInstr][Clang][NFC] Don't set -dwarf-use-key-instructions

Once #144104 lands the flag is true by default (because each DISubprogram will
track whether or not it's using key instructions).
---
 clang/lib/Driver/ToolChains/Clang.cpp         |  5 +----
 clang/test/DebugInfo/KeyInstructions/flag.cpp | 10 ++++++++--
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 8556bcadf0915..e3e79a4894cd7 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -4627,11 +4627,8 @@ renderDebugOptions(const ToolChain &TC, const Driver &D, const llvm::Triple &T,
   }
 
   if (Args.hasFlag(options::OPT_gkey_instructions,
-                   options::OPT_gno_key_instructions, false)) {
+                   options::OPT_gno_key_instructions, false))
     CmdArgs.push_back("-gkey-instructions");
-    CmdArgs.push_back("-mllvm");
-    CmdArgs.push_back("-dwarf-use-key-instructions");
-  }
 
   if (EmitCodeView) {
     CmdArgs.push_back("-gcodeview");
diff --git a/clang/test/DebugInfo/KeyInstructions/flag.cpp b/clang/test/DebugInfo/KeyInstructions/flag.cpp
index 93503dd4bdb4c..8ce140a2ca031 100644
--- a/clang/test/DebugInfo/KeyInstructions/flag.cpp
+++ b/clang/test/DebugInfo/KeyInstructions/flag.cpp
@@ -8,8 +8,14 @@
 // HELP-NOT: key-instructions
 
 // KEY-INSTRUCTIONS: "-gkey-instructions"
-// KEY-INSTRUCTIONS: "-mllvm" "-dwarf-use-key-instructions"
 
 // NO-KEY-INSTRUCTIONS-NOT: key-instructions
 
-//// TODO: Add smoke test once some functionality has been added.
+// RUN %clang %s | FileCheck %s --check-prefix=SMOKETEST-OFF
+void f() {}
+// SMOKETEST-OFF-NOT: keyInstructions
+// SMOKETEST-OFF-NOT: atomGroup
+
+// RUN %clang %s -gkey-instructions | FileCheck %s --check-prefix=SMOKETEST-ON
+// SMOKETEST-ON: keyInstructions: true
+// SMOKETEST-ON: atomGroup: 1