[clang] Add -mno-unaligned-access and -mbig-endian to ARM and AArch64 multilib flags (PR #114782)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-driver

Author: None (simpal01)

<details>
<summary>Changes</summary>

This adds the -mno-unaligned-access and -mbig-endian command line options to the set of flags used by the multilib selection for ARM and AArch64 targets.

---
Full diff: https://github.com/llvm/llvm-project/pull/114782.diff


2 Files Affected:

- (modified) clang/lib/Driver/ToolChain.cpp (+25) 
- (modified) clang/test/Driver/print-multi-selection-flags.c (+8) 


``````````diff
diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index bdf3da0c96adca..dec9af62ad79e4 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -230,6 +230,18 @@ static void getAArch64MultilibFlags(const Driver &D,
     Result.push_back(BranchProtectionArg->getAsString(Args));
   }
 
+  const Arg *StrictAlignArg =
+      Args.getLastArgNoClaim(options::OPT_mstrict_align, options::OPT_mno_unaligned_access);
+  if (StrictAlignArg) {
+    Result.push_back(StrictAlignArg->getAsString(Args));
+  }
+
+  const Arg *BigEndian =
+      Args.getLastArgNoClaim(options::OPT_mbig_endian);
+  if (BigEndian) {
+    Result.push_back(BigEndian->getAsString(Args));
+  }
+
   const Arg *ABIArg = Args.getLastArgNoClaim(options::OPT_mabi_EQ);
   if (ABIArg) {
     Result.push_back(ABIArg->getAsString(Args));
@@ -287,6 +299,19 @@ static void getARMMultilibFlags(const Driver &D,
   if (BranchProtectionArg) {
     Result.push_back(BranchProtectionArg->getAsString(Args));
   }
+
+  const Arg *StrictAlignArg =
+      Args.getLastArgNoClaim(options::OPT_mstrict_align, options::
+OPT_mno_unaligned_access);
+  if (StrictAlignArg) {
+    Result.push_back(StrictAlignArg->getAsString(Args));
+  }
+
+  const Arg *BigEndian =
+      Args.getLastArgNoClaim(options::OPT_mbig_endian);
+  if (BigEndian) {
+    Result.push_back(BigEndian->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 4bb62665ad8981..5bf6dca5096a73 100644
--- a/clang/test/Driver/print-multi-selection-flags.c
+++ b/clang/test/Driver/print-multi-selection-flags.c
@@ -68,6 +68,14 @@
 // RUN: %clang -multi-lib-config=%S/Inputs/multilib/empty.yaml -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 -multi-lib-config=%S/Inputs/multilib/empty.yaml -print-multi-flags-experimental --target=arm-none-eabi -mno-unaligned-access | FileCheck --check-prefix=CHECK-NO-UNALIGNED-ACCESS %s
+// RUN: %clang -multi-lib-config=%S/Inputs/multilib/empty.yaml -print-multi-flags-experimental --target=aarch64-none-elf -mno-unaligned-access | FileCheck --check-prefix=CHECK-NO-UNALIGNED-ACCESS %s
+// CHECK-NO-UNALIGNED-ACCESS: -mno-unaligned-access
+
+// RUN: %clang -multi-lib-config=%S/Inputs/multilib/empty.yaml -print-multi-flags-experimental --target=arm-none-eabi -mbig-endian | FileCheck --check-prefix=CHECK-BIG-ENDIAN %s
+// RUN: %clang -multi-lib-config=%S/Inputs/multilib/empty.yaml -print-multi-flags-experimental --target=aarch64-none-elf -mbig-endian | FileCheck --check-prefix=CHECK-BIG-ENDIAN %s
+// CHECK-BIG-ENDIAN: -mbig-endian
+
 // RUN: %clang -multi-lib-config=%S/Inputs/multilib/empty.yaml -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

``````````

</details>


https://github.com/llvm/llvm-project/pull/114782