resolve failed for macro-2.0

[bvanjoi]

I tried this code:

#![feature(decl_macro)]
macro_rules! m {
    ($i:ident) => {
        mod $i {
            pub struct A;
        }
    }
}

m!(x);

fn main() {
    let a: x::A = x::A;
}

I expected to see this happen: compile pass

Instead, this happened: compile failed and report: "error[E0412]: cannot find type A in module x"

Meta

rustc --version --verbose:

rustc 1.73.0-nightly (32303b219 2023-07-29)
binary: rustc
commit-hash: 32303b219d4dffa447aa606bc11c7a648f44a862
commit-date: 2023-07-29
host: aarch64-apple-darwin
release: 1.73.0-nightly
LLVM version: 16.0.5

[ehuss]

Thanks for the report! I believe this is the same as #91249. The identifiers in the macro have def-site hygiene, which makes them unavailable at the call-site. decl_macros are still unfinished, and I believe controlling hygiene is one of the things that still needs some work.

[ScottLL]

Add the macro 'm!(x)' to the code which will declare the type 'x::A'. This should fix the error encountered.

[fmease]

Your code actually compiles, you'd need to replace macro_rules! with macro to get the error you mentioned.

In any case, as ehuss said, macros 2.0 employ def-site hygiene. Closing as duplicate of #91249.