[clang] [HIP] Replace use of `llvm-mc` with `clang` (PR #112041)

[Joseph Huber via cfe-commits]

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@@ -463,10 +463,11 @@ void HIP::constructGenerateObjFileFromHIPFatBinary(
 
   Objf << ObjBuffer;
 
-  ArgStringList McArgs{"-triple", Args.MakeArgString(HostTriple.normalize()),
+  ArgStringList McArgs{"-target", Args.MakeArgString(HostTriple.normalize()),
                        "-o",      Output.getFilename(),
-                       McinFile,  "--filetype=obj"};
-  const char *Mc = Args.MakeArgString(TC.GetProgramPath("llvm-mc"));
+                       "-x",      "assembler",
+                       ObjinFile, "-c"};
+  const char *Mc = Args.MakeArgString(TC.GetProgramPath("clang"));
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jhuber6 wrote:

I don't think there's an easy way to do this, since it would require knowing `argv[0]` basically. There's some GNU specific hacks to get that, but I don't think it's critical that the clang we invoke here is *the* amdclang, since it's just doing a simple assembler to object file job.

https://github.com/llvm/llvm-project/pull/112041