[SYCL] DPC++ CCache Support

[ax3l]

Hi,

although this probably needs a change in ccache (repo) itself: are there plans to support dpcpp with ccache? Just opening this to indicate that we (cc @WeiqunZhang) rely on it heavily for productive development workflows.

Thanks for considering!

[AlexeySachkov]

Hi @ax3l,

I did some experiments with ccache some time ago using simple SYCL/DPC++ apps and I was able to do so just fine.
A few notable moments, though:

ccache which is available in Ubuntu 20 repos is a bit outdated (for me it was 3.4.1) and per the docs it doesn't have a mechanism to tell which kind/type of compiler is being used - that version was mainly designed for gcc and not for clang.

So, I've updated it to the latest 4.2.1 and used compiler_type configuration option to tell the tool that dpcpp is a clang-based compiler - this setup worked just fine on a simple app.

Could you please try it yourself and see if it works for you? I haven't used ccache so I don't know what are regular and most popular use-cases to test them myself.

[WeiqunZhang]

I can confirm that ccache and dpcpp now work for me. I am using ccache 4.3 and oneAPI 2021.2.0. I am also using it without specifying compiler_type. It seems to just work fine.

[ax3l]

Awesome, thanks a lot for testing and confirming!