Building skia with clang(-cl)

[Miklos Vajna]

Hi,

In short, I would like to hear what others think about using clang(-cl)
for building skia.

Why? See this video from Lubos, showing skia raster performance on
Windows: <https://youtu.be/iSo4wVtGQ2A>. Above is clang-cl, below is
MSVC. The reason for the difference is that skia developers focus on
good performance with clang, so building their codebase with gcc or msvc
works, but the result is not as great as it could be. This would be the
benefit.

(This is raster rendering; if the needed HW is in place, then Vulkan
rendering is used, and that's not a problem with msvc/gcc, either.)

Regarding the cost, clang-cl is actually just 1 more click when you
install Visual Studio 2019, it's not something you need to download from
llvm.org separately.

Current state is that you get a more or less silent warning from
configure if clang is missing; and it's used to build skia (and only
skia, to be conservative) if it's found.

I think it would make sense to make this more strict and:

1) Make the warning more visible, i.e. a yellow warning at the end of
configure, that is actually noticed by most people.

2) Make the warning an error in case of release builds (or something
like that).

What do others think?

Thanks,

Miklos
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 195 bytes
Desc: Digital signature
URL: <https://lists.freedesktop.org/archives/libreoffice/attachments/20200423/5f5b40ed/attachment.sig>