[clang] [Driver] Add -mbranch-protection to ARM and AArch64 multilib flags (PR #106391)

[Lucas Duarte Prates via cfe-commits]

https://github.com/pratlucas updated https://github.com/llvm/llvm-project/pull/106391

>From b3d7b528a422f7c44b535c480acbd74f03555b4d Mon Sep 17 00:00:00 2001
From: Lucas Prates <lucas.prates at arm.com>
Date: Wed, 28 Aug 2024 13:58:57 +0100
Subject: [PATCH 1/2] [Driver] Add -mbranch-protection to ARM and AArch64
 multilib flags

This adds the `-mbranch-protection` command line option to the set of
flags used by the multilib selection for ARM and AArch64 targets.
---
 clang/lib/Driver/ToolChain.cpp                  | 10 ++++++++++
 clang/test/Driver/print-multi-selection-flags.c |  4 ++++
 2 files changed, 14 insertions(+)

diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index c93c97146b6104..442512366c9114 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -221,6 +221,11 @@ static void getAArch64MultilibFlags(const Driver &D,
   assert(!ArchName.empty() && "at least one architecture should be found");
   MArch.insert(MArch.begin(), ("-march=" + ArchName).str());
   Result.push_back(llvm::join(MArch, "+"));
+
+  const Arg *BranchProtectionArg = Args.getLastArgNoClaim(options::OPT_mbranch_protection_EQ);
+  if (BranchProtectionArg) {
+    Result.push_back(BranchProtectionArg->getAsString(Args));
+  }
 }
 
 static void getARMMultilibFlags(const Driver &D,
@@ -268,6 +273,11 @@ static void getARMMultilibFlags(const Driver &D,
   case arm::FloatABI::Invalid:
     llvm_unreachable("Invalid float ABI");
   }
+
+  const Arg *BranchProtectionArg = Args.getLastArgNoClaim(options::OPT_mbranch_protection_EQ);
+  if (BranchProtectionArg) {
+    Result.push_back(BranchProtectionArg->getAsString(Args));
+  }
 }
 
 static void getRISCVMultilibFlags(const Driver &D, const llvm::Triple &Triple,
diff --git a/clang/test/Driver/print-multi-selection-flags.c b/clang/test/Driver/print-multi-selection-flags.c
index 2770a3ad5eaa1d..0116c7f5a03b9a 100644
--- a/clang/test/Driver/print-multi-selection-flags.c
+++ b/clang/test/Driver/print-multi-selection-flags.c
@@ -59,6 +59,10 @@
 // CHECK-SVE2: --target=aarch64-unknown-none-elf
 // CHECK-SVE2: -march=armv{{.*}}-a{{.*}}+simd{{.*}}+sve{{.*}}+sve2{{.*}}
 
+// RUN: %clang -print-multi-flags-experimental --target=arm-none-eabi -mbranch-protection=standard    | FileCheck --check-prefix=CHECK-BRANCH-PROTECTION %s
+// RUN: %clang -print-multi-flags-experimental --target=aarch64-none-elf -mbranch-protection=standard | FileCheck --check-prefix=CHECK-BRANCH-PROTECTION %s
+// CHECK-BRANCH-PROTECTION: -mbranch-protection=standard
+
 // RUN: %clang -print-multi-flags-experimental --target=riscv32-none-elf -march=rv32g | FileCheck --check-prefix=CHECK-RV32 %s
 // CHECK-RV32: --target=riscv32-unknown-none-elf
 // CHECK-RV32: -mabi=ilp32d

>From 5187e069c0f3da4f5dbbfd064c7ceb8e383a2371 Mon Sep 17 00:00:00 2001
From: Lucas Prates <lucas.prates at arm.com>
Date: Wed, 28 Aug 2024 14:50:53 +0100
Subject: [PATCH 2/2] fixup! [Driver] Add -mbranch-protection to ARM and
 AArch64 multilib flags

---
 clang/lib/Driver/ToolChain.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index 442512366c9114..76901875c66959 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -222,7 +222,8 @@ static void getAArch64MultilibFlags(const Driver &D,
   MArch.insert(MArch.begin(), ("-march=" + ArchName).str());
   Result.push_back(llvm::join(MArch, "+"));
 
-  const Arg *BranchProtectionArg = Args.getLastArgNoClaim(options::OPT_mbranch_protection_EQ);
+  const Arg *BranchProtectionArg =
+      Args.getLastArgNoClaim(options::OPT_mbranch_protection_EQ);
   if (BranchProtectionArg) {
     Result.push_back(BranchProtectionArg->getAsString(Args));
   }
@@ -274,7 +275,8 @@ static void getARMMultilibFlags(const Driver &D,
     llvm_unreachable("Invalid float ABI");
   }
 
-  const Arg *BranchProtectionArg = Args.getLastArgNoClaim(options::OPT_mbranch_protection_EQ);
+  const Arg *BranchProtectionArg =
+      Args.getLastArgNoClaim(options::OPT_mbranch_protection_EQ);
   if (BranchProtectionArg) {
     Result.push_back(BranchProtectionArg->getAsString(Args));
   }