rust/compiler/rustc_lint
bors 63ef74b6aa Auto merge of #111717 - Urgau:uplift_fn_null_check, r=oli-obk
Uplift `clippy::fn_null_check` lint

This PR aims at uplifting the `clippy::fn_null_check` lint into rustc.

## `incorrect_fn_null_checks`

(warn-by-default)

The `incorrect_fn_null_checks` lint checks for expression that checks if a function pointer is null.

### Example

```rust
let fn_ptr: fn() = /* somehow obtained nullable function pointer */

if (fn_ptr as *const ()).is_null() { /* ... */ }
```

### Explanation

Function pointers are assumed to be non-null, checking for their nullity is incorrect.

-----

Mostly followed the instructions for uplifting a clippy lint described here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751

`@rustbot` label: +I-lang-nominated
r? compiler
2023-07-11 09:34:48 +00:00
..
src Auto merge of #111717 - Urgau:uplift_fn_null_check, r=oli-obk 2023-07-11 09:34:48 +00:00
Cargo.toml Add `rustc_fluent_macro` to decouple fluent from `rustc_macros` 2023-04-18 18:56:22 +00:00
messages.ftl Uplift `clippy::fn_null_check` to rustc 2023-07-10 18:12:41 +02:00