| #### Note: this error code is no longer emitted by the compiler. |
| |
| The `unwind` attribute was malformed. |
| |
| Erroneous code example: |
| |
| ```compile_fail |
| #![feature(unwind_attributes)] |
| |
| #[unwind()] // error: expected one argument |
| pub extern "C" fn something() {} |
| |
| fn main() {} |
| ``` |
| |
| The `#[unwind]` attribute should be used as follows: |
| |
| - `#[unwind(aborts)]` -- specifies that if a non-Rust ABI function |
| should abort the process if it attempts to unwind. This is the safer |
| and preferred option. |
| |
| - `#[unwind(allowed)]` -- specifies that a non-Rust ABI function |
| should be allowed to unwind. This can easily result in Undefined |
| Behavior (UB), so be careful. |
| |
| NB. The default behavior here is "allowed", but this is unspecified |
| and likely to change in the future. |
