1319156 - Allow specifying cargo features for Rust libraries from moz.build

Status: RESOLVED FIXED

(Firefox Build System :: General, defect)

Description

[Manish Goregaokar [:manishearth]]

It should be possible to set `RUST_LIBRARIES['foo'].features += ["random-feature"]` and have the contents passed to `--features` in `cargo build`

Comment 1

[Nathan Froyd [:froydnj]]

Attachment: part 1 - add features to RustLibrary objects and moz.build definitions

Ideally, people will just use the extra argument to RustLibrary to
define features for their library.

Comment 2

[Nathan Froyd [:froydnj]]

Attachment: part 2 - handle Rust library features in the recursivemake backend

Comment 3

[Nathan Froyd [:froydnj]]

Attachment: part 3 - tests for Rust library features, frontend and backend

This commit also adds an overdue test for plain Rust libraries in the
recursivemake backend, but said test also serves to ensure that we don't
emit features for a library if none were defined in moz.build.

Comment 4

[Chris Manchester (limited bugmail, email directly)]

Comment on attachment 8815313 [details] [diff] [review]
part 3 - tests for Rust library features, frontend and backend

Review of attachment 8815313 [details] [diff] [review]:
-----------------------------------------------------------------

::: python/mozbuild/mozbuild/test/frontend/data/rust-library-features/moz.build
@@ +15,5 @@
> +    IS_RUST_LIBRARY = True
> +    RUST_LIBRARY_FEATURES = features
> +
> +
> +RustLibrary('random-crate', ['musthave', 'cantlivewithout'])

Do we get a nice error message is someone passes a string instead of a list for features?

Comment 5

[Nathan Froyd [:froydnj]]

(In reply to Chris Manchester (:chmanchester) from comment #4)
> > +RustLibrary('random-crate', ['musthave', 'cantlivewithout'])
> 
> Do we get a nice error message is someone passes a string instead of a list
> for features?

I believe we'll get an exception when the non-list thing is assigned to RUST_LIBRARY_FEATURES in the template.  Is that sufficient, do you think, or should we try to provide a higher level error from the template itself?  (Can templates even raise exceptions?)

Comment 6

[Chris Manchester (limited bugmail, email directly)]

Maybe we could do an explicit check and call `error` in the template, but really, that sounds fine.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/8276296cd505
part 1 - add features to RustLibrary objects and moz.build definitions; r=chmanchester
https://hg.mozilla.org/integration/mozilla-inbound/rev/b5de6b777970
part 2 - handle Rust library features in the recursivemake backend; r=chmanchester
https://hg.mozilla.org/integration/mozilla-inbound/rev/db686076ae29
part 3 - tests for Rust library features, frontend and backend; r=chmanchester

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/a7ab3fbb933f
followup - only assign RUST_LIBRARY_FEATURES when features are provided to RustLibrary; r=me

Comment 9

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/8276296cd505
https://hg.mozilla.org/mozilla-central/rev/b5de6b777970
https://hg.mozilla.org/mozilla-central/rev/db686076ae29
https://hg.mozilla.org/mozilla-central/rev/a7ab3fbb933f