bilge generates false positive errors in rust_analyzer

[denniskempin]

In a dead simple example:

use bilge::prelude::*;

#[bitsize(8)]
#[derive(FromBits)]
struct Test {
    a: u4,
    b: u4,
}

The latest version (0.3.2020) of rust_analyzer reports:

❯ rust-analyzer diagnostics .
processing crate: foo, module: /Users/denniskempin/workspace/test/foo/src/main.rs
Diagnostic { code: Ra("macro-error", Error), message: "add #[bitsize] attribute above your derive attribute", range: FileRange { file_id: FileId(11), range: 24..37 }, severity: Error, unused: false, experimental: false, fixes: None, main_node: None }

i.e.

add #[bitsize] attribute above your derive attribute from this piece of code

Oddly enough, the same error does not appear with cargo check.

[hecatia-elegua]

They might have done something to the ordering of macro execution.
I thought there is a silent agreement about that, but if not... well... it still works on the normal compiler.
Is it always happening? If yes, I would have to ask the ra devs somewhere

[showier-drastic]

Just met the same problem. Reproducible with very simple projects.

[showier-drastic]

FYI RA devs replied.

[alexkl-rugged-controls]

It looks like rust-analyzer re-evaluates derive macros once for every macro defined below it, and after the non-derive macro is evaluated, it is removed. More info here: rust-lang/rust-analyzer#17873 (comment)