[clang] [Multilib] Extend support for -fmultilib-flag to RISC-V (PR #182220)

[via cfe-commits]

https://github.com/pzhengqc created https://github.com/llvm/llvm-project/pull/182220

Support for the `-fmultilib-flag` option has been added to AArch64/ARM. This patch extends the support of the flag to RISC-V.

>From 028cd1bf8bde26c8eec7543e0084a580cc96580c Mon Sep 17 00:00:00 2001
From: Pengxuan Zheng <pzheng at qti.qualcomm.com>
Date: Wed, 18 Feb 2026 21:11:43 -0800
Subject: [PATCH] [Multilib] Extend support for -fmultilib-flag to RISC-V

Support for the `-fmultilib-flag` option has been added to AArch64/ARM. This
patch extends the support of the flag to RISC-V.
---
 clang/lib/Driver/ToolChain.cpp                  | 6 ++----
 clang/test/Driver/print-multi-selection-flags.c | 2 ++
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index 0eee7f917d2b8..71b1ece1880b4 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -229,8 +229,6 @@ static void getAArch64MultilibFlags(const Driver &D,
       break;
     }
   }
-
-  processMultilibCustomFlags(Result, Args);
 }
 
 static void getARMMultilibFlags(const Driver &D, const llvm::Triple &Triple,
@@ -319,8 +317,6 @@ static void getARMMultilibFlags(const Driver &D, const llvm::Triple &Triple,
       break;
     }
   }
-
-  processMultilibCustomFlags(Result, Args);
 }
 
 static void getRISCVMultilibFlags(const Driver &D, const llvm::Triple &Triple,
@@ -378,6 +374,8 @@ ToolChain::getMultilibFlags(const llvm::opt::ArgList &Args) const {
     break;
   }
 
+  processMultilibCustomFlags(Result, Args);
+
   // Include fno-exceptions and fno-rtti
   // to improve multilib selection
   if (getRTTIMode() == ToolChain::RTTIMode::RM_Disabled)
diff --git a/clang/test/Driver/print-multi-selection-flags.c b/clang/test/Driver/print-multi-selection-flags.c
index b1a0a29ec4180..4a98e7c5e9904 100644
--- a/clang/test/Driver/print-multi-selection-flags.c
+++ b/clang/test/Driver/print-multi-selection-flags.c
@@ -103,8 +103,10 @@
 
 // RUN: %clang -multi-lib-config=%S/Inputs/multilib/multilib-custom-flags.yaml -print-multi-flags-experimental --target=armv8m.main-none-eabi -fmultilib-flag=foo -fmultilib-flag=bar | FileCheck --check-prefixes=CHECK-MULTILIB-CUSTOM-FLAG,CHECK-ARM-MULTILIB-CUSTOM-FLAG %s
 // RUN: %clang -multi-lib-config=%S/Inputs/multilib/multilib-custom-flags.yaml -print-multi-flags-experimental --target=aarch64-none-eabi     -fmultilib-flag=foo -fmultilib-flag=bar | FileCheck --check-prefixes=CHECK-MULTILIB-CUSTOM-FLAG,CHECK-AARCH64-MULTILIB-CUSTOM-FLAG %s
+// RUN: %clang -multi-lib-config=%S/Inputs/multilib/multilib-custom-flags.yaml -print-multi-flags-experimental --target=riscv64-none-elf -fmultilib-flag=foo -fmultilib-flag=bar | FileCheck --check-prefixes=CHECK-MULTILIB-CUSTOM-FLAG,CHECK-RISCV-MULTILIB-CUSTOM-FLAG %s
 // CHECK-ARM-MULTILIB-CUSTOM-FLAG:     --target=thumbv8m.main-unknown-none-eabi
 // CHECK-AARCH64-MULTILIB-CUSTOM-FLAG: --target=aarch64-unknown-none-eabi
+// CHECK-RISCV-MULTILIB-CUSTOM-FLAG:   --target=riscv64-unknown-none-elf
 // CHECK-MULTILIB-CUSTOM-FLAG-DAG:     -fmultilib-flag=foo
 // CHECK-MULTILIB-CUSTOM-FLAG-DAG:     -fmultilib-flag=bar