rust/tests/ui/ptr_cast_constness.rs
Samuel Tardieu 30608732c2 Handle null pointer constness cast through methods
This covers two cases:

- `core::ptr::null::<T>().cast_mut()` -> `core::ptr::null_mut::<T>()`
- `core::ptr::null_mut::<T>().cast_const()` -> `core::ptr::null::<T>()`
2024-09-09 10:18:31 +02:00

88 lines
2.4 KiB
Rust

//@aux-build:proc_macros.rs
#![warn(clippy::ptr_cast_constness)]
#![allow(
clippy::transmute_ptr_to_ref,
clippy::unnecessary_cast,
unused,
clippy::missing_transmute_annotations
)]
extern crate proc_macros;
use proc_macros::{external, inline_macros};
unsafe fn ptr_to_ref<T, U>(p: *const T, om: *mut U) {
let _: &mut T = std::mem::transmute(p as *mut T);
let _ = &mut *(p as *mut T);
let _: &T = &*(om as *const T);
}
#[inline_macros]
fn main() {
let ptr: *const u32 = &42_u32;
let mut_ptr: *mut u32 = &mut 42_u32;
let _ = ptr as *const u32;
let _ = mut_ptr as *mut u32;
// Make sure the lint can handle the difference in their operator precedences.
unsafe {
let ptr_ptr: *const *const u32 = &ptr;
let _ = *ptr_ptr as *mut u32;
}
let _ = ptr as *mut u32;
let _ = mut_ptr as *const u32;
// Lint this, since pointer::cast_mut and pointer::cast_const have ?Sized
let ptr_of_array: *const [u32; 4] = &[1, 2, 3, 4];
let _ = ptr_of_array as *const [u32];
let _ = ptr_of_array as *const dyn std::fmt::Debug;
// Make sure the lint is triggered inside a macro
let _ = inline!($ptr as *const u32);
// Do not lint inside macros from external crates
let _ = external!($ptr as *const u32);
}
fn lifetime_to_static(v: *mut &()) -> *const &'static () {
v as _
}
#[clippy::msrv = "1.64"]
fn _msrv_1_64() {
let ptr: *const u32 = &42_u32;
let mut_ptr: *mut u32 = &mut 42_u32;
// `pointer::cast_const` and `pointer::cast_mut` were stabilized in 1.65. Do not lint this
let _ = ptr as *mut u32;
let _ = mut_ptr as *const u32;
}
#[clippy::msrv = "1.65"]
fn _msrv_1_65() {
let ptr: *const u32 = &42_u32;
let mut_ptr: *mut u32 = &mut 42_u32;
let _ = ptr as *mut u32;
let _ = mut_ptr as *const u32;
}
#[inline_macros]
fn null_pointers() {
use std::ptr;
let _ = ptr::null::<String>() as *mut String;
let _ = ptr::null_mut::<u32>() as *const u32;
let _ = ptr::null::<u32>().cast_mut();
let _ = ptr::null_mut::<u32>().cast_const();
// Make sure the lint is triggered inside a macro
let _ = inline!(ptr::null::<u32>() as *mut u32);
let _ = inline!(ptr::null::<u32>().cast_mut());
// Do not lint inside macros from external crates
let _ = external!(ptr::null::<u32>() as *mut u32);
let _ = external!(ptr::null::<u32>().cast_mut());
}