1599921 - Make rust atom!() actually generate consts.

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, task)

Description

[Emilio Cobos Álvarez (:emilio)]

I see atom dropping code generated in release builds for stuff like dropping the class atom here: https://searchfox.org/mozilla-central/rev/4df8821c1b824db5f40f381f48432f219d99ae36/servo/components/style/gecko/wrapper.rs#592

That is silly, and I hope making Atom be able to be used in const context will help the compiler see that yeah, we're not doing anything interesting and the atom shouldn't get dropped.

It also allows us to get rid of a few lazy_static!s, so we should do it anyway.

Comment 1

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1599921 - Make Rust static atoms able to be used in const contexts. r=enordin,boris,#style

I see atom dropping code generated in release builds for stuff like dropping the
"class" atom here:

https://searchfox.org/mozilla-central/rev/4df8821c1b824db5f40f381f48432f219d99ae36/servo/components/style/gecko/wrapper.rs#592

That is silly, and I hope making Atom be able to be used in const context will
help the compiler see that yeah, we're not doing anything interesting and the
atom shouldn't get dropped.

It also allows us to get rid of a few lazy_static!s, so we should do it anyway.

In order to accomplish this, compute the offset into gGkAtoms manually instead
of going through the static_atoms() array and then back to the byte offset.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e4813b5e0662
Make Rust static atoms able to be used in const contexts. r=boris

Comment 3

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/e4813b5e0662