[clang] [AMDGPU] Correctly determine the toolchain linker (PR #89803)

[Joseph Huber via cfe-commits]

https://github.com/jhuber6 created https://github.com/llvm/llvm-project/pull/89803

Summary:
The AMDGPU toolchain simply took the short name to get the link job
instead of using the common utilities that respect options like
`-fuse-ld`. Any linker that isn't `ld.lld` will fail, however we should
be able to override it.


>From 9389f7831f89e201b09d13bda4e3852968718e32 Mon Sep 17 00:00:00 2001
From: Joseph Huber <huberjn at outlook.com>
Date: Tue, 23 Apr 2024 12:46:09 -0500
Subject: [PATCH] [AMDGPU] Correctly determine the toolchain linker

Summary:
The AMDGPU toolchain simply took the short name to get the link job
instead of using the common utilities that respect options like
`-fuse-ld`. Any linker that isn't `ld.lld` will fail, however we should
be able to override it.
---
 clang/lib/Driver/ToolChains/AMDGPU.cpp | 3 +--
 clang/test/Driver/amdgpu-toolchain.c   | 6 ++++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Driver/ToolChains/AMDGPU.cpp b/clang/lib/Driver/ToolChains/AMDGPU.cpp
index 4e6362a0f40632..07965b487ea79b 100644
--- a/clang/lib/Driver/ToolChains/AMDGPU.cpp
+++ b/clang/lib/Driver/ToolChains/AMDGPU.cpp
@@ -617,8 +617,7 @@ void amdgpu::Linker::ConstructJob(Compilation &C, const JobAction &JA,
                                   const InputInfoList &Inputs,
                                   const ArgList &Args,
                                   const char *LinkingOutput) const {
-
-  std::string Linker = getToolChain().GetProgramPath(getShortName());
+  std::string Linker = getToolChain().GetLinkerPath();
   ArgStringList CmdArgs;
   CmdArgs.push_back("--no-undefined");
   CmdArgs.push_back("-shared");
diff --git a/clang/test/Driver/amdgpu-toolchain.c b/clang/test/Driver/amdgpu-toolchain.c
index 4300e7e9f66705..d21ce857f3c57a 100644
--- a/clang/test/Driver/amdgpu-toolchain.c
+++ b/clang/test/Driver/amdgpu-toolchain.c
@@ -24,3 +24,9 @@
 // RUN:   -L. -fconvergent-functions %s 2>&1 | FileCheck -check-prefix=MCPU %s
 // LTO: clang{{.*}} "-flto=full"{{.*}}"-fconvergent-functions"
 // MCPU: ld.lld{{.*}}"-L."{{.*}}"-plugin-opt=mcpu=gfx906"
+
+// We do not suppor the BFD linker, but we should be able to override the
+// default even if it will error during linking.
+// RUN: %clang -### --target=amdgcn-amd-amdhsa -mcpu=gfx906 -nogpulib \
+// RUN:   -fuse-ld=bfd %s 2>&1 | FileCheck -check-prefixes=LD %s
+// LD: ld.bfd"