no_std compatible

[Tim-Paik]

I'm trying to run a boa engine on a bare metal environment, is this possible? Are there any current plans to support no_std?

[jedel1043]

That's a tough one. I'd have to ask, do you need to avoid all heap allocations or can you target alloc instead of core?

[Tim-Paik]

That's a tough one. I'd have to ask, do you need to avoid all heap allocations or can you target alloc instead of core?

For this case, I think we can assume that alloc can be used, otherwise it would be too hard

[jedel1043]

Then it shouldn't be too hard! Boa is self-contained, and doesn't make any file system calls (with the exception on Intl, since we need to get the machine locale of an user, but it should be trivial to skip doing that on no_std builds).

[jedel1043]

I'll try to patch Boa with the changes on the weekend

[jedel1043]

Huh, so apparently the gc crate depends on std (https://github.com/Manishearth/rust-gc/blob/6c5f754682e573e4590b52168dce835bba28beaf/gc_derive/src/lib.rs#L59), but I'm pretty sure that was unintended, since core::ops::Drop exists. This unfortunately blocks this issue, but I'll open a PR on the gc crate to fix this ASAP.

[jedel1043]

Ah, gc uses thread locals... https://github.com/Manishearth/rust-gc/blob/6c5f754682e573e4590b52168dce835bba28beaf/gc/src/gc.rs#L24

This unfortunately blocks us from having compatibility with no_std. We'll need to design our own garbage collector if we want this.

[Tim-Paik]

Great work! In fact, I also tried to modify the boa myself, but it didn't work (x
I guess gc should be prepared to use threads for performance (though it's still single-threaded gc for now)

[jedel1043]

Working on this at the moment.

[jedel1043]

Closing in favour of #2543.