Code
#[cfg_trace]
fn main() {}
#[cfg_attr_trace]
fn foo() {}Current output
error: cannot find attribute `cfg_trace` in this scope
--> test.rs:3:3
|
3 | #[cfg_trace]
| ^^^^^^^^^
|
help: a built-in attribute with a similar name exists
|
3 - #[cfg_trace]
3 + #[<cfg_trace>]
|
error: cannot find attribute `cfg_attr_trace` in this scope
--> test.rs:1:3
|
1 | #[cfg_attr_trace]
| ^^^^^^^^^^^^^^
|
help: a built-in attribute with a similar name exists
|
1 - #[cfg_attr_trace]
1 + #[<cfg_attr_trace>]
|
error: aborting due to 2 previous errors
Desired output
error: cannot find attribute `cfg_trace` in this scope
--> test.rs:3:3
|
3 | #[cfg_trace]
| ^^^^^^^^^
error: cannot find attribute `cfg_attr_trace` in this scope
--> test.rs:1:3
|
1 | #[cfg_attr_trace]
| ^^^^^^^^^^^^^^
error: aborting due to 2 previous errors
Rationale and extra context
this is a diagnostic regression
Other cases
Rust Version
rustc 1.94.0-nightly (8d670b93d 2025-12-31)
binary: rustc
commit-hash: 8d670b93d40737e1b320fd892c6f169ffa35e49e
commit-date: 2025-12-31
host: x86_64-unknown-linux-gnu
release: 1.94.0-nightly
LLVM version: 21.1.8
Anything else?
#[cfg_trace] and #[cfg_attr_trace] are really compiler internals, and I think we should maybe change their names to reflect this? i.e. make it #[rustc_cfg_trace] and #[rustc_cfg_attr_trace], this would also lead to better error messages in general if someone tried to use them
other attributes that are added during codegen are marked like this, see for example #[rustc_test_marker]
Code
Current output
Desired output
Rationale and extra context
this is a diagnostic regression
Other cases
Rust Version
Anything else?
#[cfg_trace]and#[cfg_attr_trace]are really compiler internals, and I think we should maybe change their names to reflect this? i.e. make it#[rustc_cfg_trace]and#[rustc_cfg_attr_trace], this would also lead to better error messages in general if someone tried to use themother attributes that are added during codegen are marked like this, see for example
#[rustc_test_marker]