On Tue, Jul 10, 2018 at 1:29 PM, David Major <
dma...@mozilla.com> wrote:
> Bug 1443590 is switching our official Windows builds to use clang-cl
> as the compiler.
>
> Please keep an eye out for regressions and file a blocking bug for
> anything that might be fallout from this change. I'm especially
> interested in hearing about the quality of the debugging experience.
>
> It's possible that the patch may bounce and we'll go back and forth to
> MSVC for a while. You can check your build's compiler at
> `about:buildconfig`. Treeherder is running an additional set of MSVC
> jobs on mozilla-central to make sure we can fall back to a green MSVC
> if needed.
>
> Watch for more toolchain changes to come. The next steps after this
> will be to switch to lld-link and enable ThinLTO. That will open the
> door to a cross-language LTO that could inline calls between Rust and
> C++. In the longer term we can look into cross-compiling from Linux.
>
> But for now, shipping our most-used platform with an open-source
> compiler is a huge milestone in and of itself. Big thanks to everyone
> who has contributed to this effort on the Mozilla side, and also big
> thanks to the developers of LLVM and Chromium who helped make clang on
> Windows a realistic possibility.
>
A lot of people have wanted to see this day for years (for various reasons
- an open source toolchain, potential for cross compiling, unified
toolchains across platforms, etc). This is a *major* milestone. And while
the transition will likely have a few bumps, the payoff should be well
worth it.
Thank you to everyone who helped us get here. From the initial work to
support Clang on Windows a few years ago. To the upstream work that was put
into LLVM and Clang (especially by Google/Chromium). To those that worked
through all the issues to transition the compiler today. This was a
significant effort by a lot of people. We should all be ecstatic we're
finally crossing this bridge. I know I am! Congratulations!