Unable to analyze lazy_static?

[NichtsHsu]

use lazy_static::lazy_static;
lazy_static! {
   static ref VEC: Vec<u8> = vec![0x18u8, 0x11u8];
}

fn main() {
   let b = VEC.last();
}

b will be analyzed as Option<{unknown}>.

Using the lastest version from compiling lastest master branch. Is RA unable to analyze lazy_static yet?

[edwin0cheng]

I.e :

lazy_static! {
   static ref VEC: Vec<u8> = vec![0x18u8, 0x11u8];
}

The code above expanded to: (By command Expand macro recursively)

__lazy_static_internal!(()static ref VEC:Vec<u8>  = vec![0x18u8,0x11u8];
);

And __lazy_static_internal! macro is defined as #[macro_export(local_inner_macros)]. Seem like it is because we do not support #[macro_export(local_inner_macros)] yet.

[edwin0cheng]

Fixed by #4305

OT: About 1 year ago, I started using rust-analyzer, but found that it cannot analyze lazy_static, but now it is finally done! 🎉

[teohhanhui]

If I understand correctly, this has been released in 2020-05-11, right?

Rust Analyzer: Show RA version:

rust-analyzer version: 2020-05-18 (31611da)

I'm still getting all the {unknown}s.

Code sample: https://github.com/teohhanhui/rust-exercises/blob/767414fe4034c67b8661bf0023c02c459d618c7a/temperature_converter/src/main.rs

[teohhanhui]

Looks like I should use https://docs.rs/once_cell/1.4.0/once_cell/#lazy-initialized-global-data instead 😄

[matklad]

Lol yes, at least partially, the motivation for once_cell was that IDEs at that time had troubles with lazy_static! :D

[edwin0cheng]

Yeah, @matklad is the best one to answer this question. Lol

[matklad]

works on master

[bjorn3]

Image is broken

[FallenWarrior2k]

Image is broken

Yes, the "Uploading image.png..." indicates the post was submitted before the image finished uploading.

In any case, lazy_static! in global scope seems to work, but when you have a lazy_static! block in a function, e.g. to keep implementation details inside, it still shows {unknown}.
I've tested this on nightly RA ("rust-analyzer.updates.channel": "nightly"), since the last comment was "works on master".

Compare:

Code for easy copy-pasting for those trying to repro:
Global:

use lazy_static::lazy_static;

lazy_static! {
    static ref VEC: Vec<u8> = vec![0u8, 1u8, 2u8];
}

fn main() {
    let x = VEC.last();
}

In function:

use lazy_static::lazy_static;

fn main() {
    lazy_static! {
        static ref VEC: Vec<u8> = vec![0u8, 1u8, 2u8];
    }

    let x = VEC.last();
}

[kiljacken]

That problem is presumably #1559