Bazel: Feature Request: Contributed BUILD Files Repository

[steven-johnson]

For C/C++ libraries that don't have Bazel support (i.e.: almost all of them), it's easy to pull down the source via new_http_archive (etc), but sometimes the Bazel BUILD file that must be constructed is decidedly nontrivial. (e.g., consider the details necessary for the libjpeg-turbo library) .

It would be a shame to force people to reinvent wheels for things like this; it would also be unfortunate to have people simply replicate these files via copy-n-paste between projects (both for licensing and maintenance reasons).

Has the Bazel team thought about encouraging a "Contributed BUILD Files" repository for this sort of thing? It seems like it would make using C/C++ with Bazel potentially a lot simpler if coders knew where to look for existing Bazel build rules and avoid reinventing wheels unnecessarily.

[kchodorow]

Yes, definitely. @mzhaom actually started one a while ago: https://github.com/mzhaom/trunk. We haven't gotten a chance to make a standardized system for it, yet.

[steven-johnson]

Didn't know about @mzhaom repo until now -- looks like a good starting point.

What would make this even cooler would be if new_http_archive() and friends could retrieve the BUILD files from a remote repo as well, e.g.

  native.new_http_archive(
     name = "jpeg",
     url = "https://github.com/libjpeg-turbo/libjpeg-turbo/archive/1.5.1.tar.gz",
     sha256 = "c15a9607892113946379ccea3ca8b85018301b200754f209453ab21674268e77",
     build_file_url = "https://github.com/mzhaom/path/to/libjpeg-turbo.BUILD",
     build_file_sha256 = "<expected SHA for BUILD file>",
  )

(Writing a wrapper around new_http_archive() to do this should be simple, of course, but having it built-in would make this workflow easier for people to rely on)

[kchodorow]

Yeah, I've been playing around with writing a repository rule that is basically:

for url in ctx.attr.urls:
   ctx.download_and_extract(url)
for script in ctx.attr.scripts:
   ctx.execute(script)

So you could download a bunch of stuff and then configure/set it up. Not sure exactly what the API should look like, yet, though.

[steven-johnson]

Contribute that rule to the repo as well.

[feliwir]

Any updates on this?

[meisterT]

There is currently nobody working on this. I am putting it in the ice-box for now and hope that the community will come with a solution.