HIP driver should not be invoking llvm-mc as the assembler

[arsenm]

Clang is currently using llvm-mc as the assembler in the HIP driver:

llvm-project/clang/lib/Driver/ToolChains/HIPUtility.cpp

Line 469 in 2bb3d3a

const char *Mc = Args.MakeArgString(TC.GetProgramPath("llvm-mc"));

llvm-mc is for assembler tests, but isn't intended for use this way. Clang itself can be invoked as the assembler, which would avoid depending on an avoidable installed binary

[llvmbot]

@llvm/issue-subscribers-backend-amdgpu

Author: Matt Arsenault (arsenm)

Clang is currently using llvm-mc as the assembler in the HIP driver: https://github.com/llvm/llvm-project/blob/2bb3d3a3f32ffaef3d9b6a27db7f1941f0cb1136/clang/lib/Driver/ToolChains/HIPUtility.cpp#L469

llvm-mc is for assembler tests, but isn't intended for use this way. Clang itself can be invoked as the assembler, which would avoid depending on an avoidable installed binary

[llvmbot]

@llvm/issue-subscribers-clang-driver

Author: Matt Arsenault (arsenm)

Clang is currently using llvm-mc as the assembler in the HIP driver: https://github.com/llvm/llvm-project/blob/2bb3d3a3f32ffaef3d9b6a27db7f1941f0cb1136/clang/lib/Driver/ToolChains/HIPUtility.cpp#L469

llvm-mc is for assembler tests, but isn't intended for use this way. Clang itself can be invoked as the assembler, which would avoid depending on an avoidable installed binary

[jhuber6]

Yeah we can just do the same thing the linker wrapper does, clang --target=amdgcn-amd-amdhsa.

[jhuber6]

Anything that stops us from invoking the compiler inside of the clang driver? Could also just do that.

[arsenm]

Anything that stops us from invoking the compiler inside of the clang driver? Could also just do that.

That is how codegen always works? Driver invokes cc1? It's the same thing, just running for asm instead of source

[jhuber6]

Anything that stops us from invoking the compiler inside of the clang driver? Could also just do that.

That is how codegen always works? Driver invokes cc1? It's the same thing, just running for asm instead of source

The one thing that just makes this a little annoying is that clang doesn't have a valid language for assembly as far as I can tell, so you need it to be inferred from the filename. Other than that, should be a pretty straightforward swap of llvm-mc to clang -c.

[arsenm]

The one thing that just makes this a little annoying is that clang doesn't have a valid language for assembly as far as I can tell

clang -x assembler (or -x assembler-with-cpp)?

[jhuber6]

The one thing that just makes this a little annoying is that clang doesn't have a valid language for assembly as far as I can tell

clang -x assembler (or -x assembler-with-cpp)?

Stand corrected, didn't see that in the list of approved user specified types in clang/lib/Types.cpp. Should be easy then.