If you are referring to a caching distributed compile cluster, most companies with large codebases are using one (or should). It helps a lot and can make the difference between taking half a day for a scratch make (i.e. unusable) to getting down to 10 min.

There are open-source ones but I'm also aware of at least two internal, custom-developed ones.

More here: https://docs.bazel.build/versions/master/remote-execution.ht...

https://github.com/bazelbuild/bazel/commit/ed7ced0018dc5c5eb... <-- would be better with DNSSEC though

Ken Thompson would be rolling in his grave if not for him being alive.

I could see this having some use in an internal manner for things like game development where you have absolutely enormous codebases (as an abstraction above compile servers and similar).

Many already use one called distcc.

My company would pay for that, up to $50/developer/month. Its a no brainier if you really get X5 speed improvements, not just for full builds but incremental as well. Of course there are tricky issues there, privacy, lock-in, how intrusive the scheme is, but the build tax in C++ has a very unappreciated impact on productivity, one that the C++ committee seems incapable of addressing.

I think there is no cloud service for this precisely because companies mostly don't want to give out their source code. Although many already rent AWS instances for their devs :)

In many companies the build cluster runs on the developers' workstations themselves, which has the benefit of fully using idling machines. The drawback is higher maintenance due to less reliability of such machines.

Would your company accept internal hosting for such a cluster, i.e. paying for the hardware themselves?

In my particular case no, it would be too much hassle for a small business like ours (we are a remote only firm with only a few people). But I can imagine it would make sense when we grow.

There is no cloud service for that ... except Google Cloud Build.

Are you aware of anyone using it for C++? I couldn't find any mention of C++ in the documentation nor via Googling (sure it will be possible but it seems to involve significant setup)

I'm not really plugged in to the industry. I've used it with bazel cc_binary targets, so I know it works.

Besides the cluster compilers used by C++.

OpenJ9 for Java can use a cloud compiler,

https://blog.openj9.org/2019/05/01/openj9-internship-making-...

.NET when AOT compiled for Windows Store uses cloud compilers, https://blogs.windows.com/windowsdeveloper/2015/08/20/net-na...

And as of Android 10, the cloud compiler is everyone's phone, because PGO data gets uploaded to the play store and improved on each device feedback.

https://android-developers.googleblog.com/2019/04/improving-...

icecream (icecc) is basically this. It’s “cloud” in that it’s distributed, but it requires surprisingly high bandwidth to the cluster, so it basically requires an office LAN connection. Or for your editor to be on that connection a la VSCode’s remote thing.

This is probably the other big reason why "cloud compilers" are rare. Not much point in using one if you can compile the source locally more quickly than you can upload it.

MBED already pioneered the cloud compiler.

Their compiler did optimizations to produce (slightly) better code than any compiler you could buy.

A lot of users were uneasy with it.

It's only at link time that object will depend on another, so you don't need a new compiler to support a "cloud" use case where any number of machines can work on compilation.

A lot of large C++ projects use link-time optimization, since it's the easiest way to get predictably good performance.