mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-23 15:23:46 +00:00
226edf64fa
Attribute values must be literals. The error you get when that doesn't hold is pretty bad, e.g.: ``` unexpected expression: 1 + 1 ``` You also get the same error if the attribute value is a literal, but an invalid literal, e.g.: ``` unexpected expression: "foo"suffix ``` This commit does two things. - Changes the error message to "attribute value must be a literal", which gives a better idea of what the problem is and how to fix it. It also no longer prints the invalid expression, because the carets below highlight it anyway. - Separates the "not a literal" case from the "invalid literal" case. Which means invalid literals now get the specific error at the literal level, rather than at the attribute level.
15 lines
423 B
Rust
15 lines
423 B
Rust
#![feature(rustc_attrs)]
|
|
|
|
#[rustc_dummy = stringify!(a)] // OK
|
|
macro_rules! bar {
|
|
() => {};
|
|
}
|
|
|
|
// FIXME?: `bar` here expands before `stringify` has a chance to expand.
|
|
// `#[rustc_dummy = ...]` is validated and dropped during expansion of `bar`,
|
|
// the "attribute value must be a literal" error comes from the validation.
|
|
#[rustc_dummy = stringify!(b)] //~ ERROR attribute value must be a literal
|
|
bar!();
|
|
|
|
fn main() {}
|