rust/tests/ui/malformed/malformed-interpolated.rs
Nicholas Nethercote 226edf64fa Improve an error involving attribute values.
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.
2023-12-12 15:54:25 +11:00

16 lines
370 B
Rust

#![feature(rustc_attrs)]
macro_rules! check {
($expr: expr) => (
#[rustc_dummy = $expr]
use main as _;
);
}
check!("0"); // OK
check!(0); // OK
check!(0u8); //~ ERROR suffixed literals are not allowed in attributes
check!(-0); //~ ERROR attribute value must be a literal
check!(0 + 0); //~ ERROR attribute value must be a literal
fn main() {}