| #### Note: this error code is no longer emitted by the compiler. |
| |
| A `#[coverage(off|on)]` attribute was found in a position where it is not |
| allowed. |
| |
| Coverage attributes can be applied to: |
| - Function and method declarations that have a body, including trait methods |
| that have a default implementation. |
| - Closure expressions, in situations where attributes can be applied to |
| expressions. |
| - `impl` blocks (inherent or trait), and modules. |
| |
| Example of erroneous code: |
| |
| ```ignore (no longer emitted) |
| unsafe extern "C" { |
| #[coverage(off)] |
| fn foreign_fn(); |
| } |
| ``` |
| |
| When using the `-C instrument-coverage` flag, coverage attributes act as a |
| hint to the compiler that it should instrument or not instrument the |
| corresponding function or enclosed functions. The precise effect of applying |
| a coverage attribute is not guaranteed and may change in future compiler |
| versions. |
