rust-clippy/tests/ui/transmute.rs

162 lines
4.6 KiB
Rust

#![allow(dead_code, clippy::borrow_as_ptr, clippy::needless_lifetimes)]
extern crate core;
use std::mem::transmute as my_transmute;
use std::vec::Vec as MyVec;
fn my_int() -> Usize {
Usize(42)
}
fn my_vec() -> MyVec<i32> {
vec![]
}
#[allow(clippy::needless_lifetimes, clippy::transmute_ptr_to_ptr)]
#[warn(clippy::useless_transmute)]
unsafe fn _generic<'a, T, U: 'a>(t: &'a T) {
// FIXME: should lint
// let _: &'a T = core::intrinsics::transmute(t);
let _: &'a U = core::intrinsics::transmute(t);
let _: *const T = core::intrinsics::transmute(t);
let _: *mut T = core::intrinsics::transmute(t);
let _: *const U = core::intrinsics::transmute(t);
}
#[warn(clippy::useless_transmute)]
fn useless() {
unsafe {
let _: Vec<i32> = core::intrinsics::transmute(my_vec());
let _: Vec<i32> = core::mem::transmute(my_vec());
let _: Vec<i32> = std::intrinsics::transmute(my_vec());
let _: Vec<i32> = std::mem::transmute(my_vec());
let _: Vec<i32> = my_transmute(my_vec());
let _: *const usize = std::mem::transmute(5_isize);
let _ = 5_isize as *const usize;
let _: *const usize = std::mem::transmute(1 + 1usize);
let _ = (1 + 1_usize) as *const usize;
}
unsafe fn _f<'a, 'b>(x: &'a u32) -> &'b u32 {
std::mem::transmute(x)
}
unsafe fn _f2<'a, 'b>(x: *const (dyn Iterator<Item = u32> + 'a)) -> *const (dyn Iterator<Item = u32> + 'b) {
std::mem::transmute(x)
}
unsafe fn _f3<'a, 'b>(x: fn(&'a u32)) -> fn(&'b u32) {
std::mem::transmute(x)
}
unsafe fn _f4<'a, 'b>(x: std::borrow::Cow<'a, str>) -> std::borrow::Cow<'b, str> {
std::mem::transmute(x)
}
}
struct Usize(usize);
#[warn(clippy::crosspointer_transmute)]
fn crosspointer() {
let mut int: Usize = Usize(0);
let int_const_ptr: *const Usize = &int as *const Usize;
let int_mut_ptr: *mut Usize = &mut int as *mut Usize;
unsafe {
let _: Usize = core::intrinsics::transmute(int_const_ptr);
let _: Usize = core::intrinsics::transmute(int_mut_ptr);
let _: *const Usize = core::intrinsics::transmute(my_int());
let _: *mut Usize = core::intrinsics::transmute(my_int());
}
}
#[warn(clippy::transmute_int_to_char)]
fn int_to_char() {
let _: char = unsafe { std::mem::transmute(0_u32) };
let _: char = unsafe { std::mem::transmute(0_i32) };
// These shouldn't warn
const _: char = unsafe { std::mem::transmute(0_u32) };
const _: char = unsafe { std::mem::transmute(0_i32) };
}
#[warn(clippy::transmute_int_to_bool)]
fn int_to_bool() {
let _: bool = unsafe { std::mem::transmute(0_u8) };
}
#[warn(clippy::transmute_int_to_float)]
mod int_to_float {
fn test() {
let _: f32 = unsafe { std::mem::transmute(0_u32) };
let _: f32 = unsafe { std::mem::transmute(0_i32) };
let _: f64 = unsafe { std::mem::transmute(0_u64) };
let _: f64 = unsafe { std::mem::transmute(0_i64) };
}
mod issue_5747 {
const VALUE32: f32 = unsafe { std::mem::transmute(0_u32) };
const VALUE64: f64 = unsafe { std::mem::transmute(0_i64) };
const fn from_bits_32(v: i32) -> f32 {
unsafe { std::mem::transmute(v) }
}
const fn from_bits_64(v: u64) -> f64 {
unsafe { std::mem::transmute(v) }
}
}
}
mod num_to_bytes {
fn test() {
unsafe {
let _: [u8; 1] = std::mem::transmute(0u8);
let _: [u8; 4] = std::mem::transmute(0u32);
let _: [u8; 16] = std::mem::transmute(0u128);
let _: [u8; 1] = std::mem::transmute(0i8);
let _: [u8; 4] = std::mem::transmute(0i32);
let _: [u8; 16] = std::mem::transmute(0i128);
let _: [u8; 4] = std::mem::transmute(0.0f32);
let _: [u8; 8] = std::mem::transmute(0.0f64);
}
}
const fn test_const() {
unsafe {
let _: [u8; 1] = std::mem::transmute(0u8);
let _: [u8; 4] = std::mem::transmute(0u32);
let _: [u8; 16] = std::mem::transmute(0u128);
let _: [u8; 1] = std::mem::transmute(0i8);
let _: [u8; 4] = std::mem::transmute(0i32);
let _: [u8; 16] = std::mem::transmute(0i128);
let _: [u8; 4] = std::mem::transmute(0.0f32);
let _: [u8; 8] = std::mem::transmute(0.0f64);
}
}
}
fn bytes_to_str(mb: &mut [u8]) {
const B: &[u8] = b"";
let _: &str = unsafe { std::mem::transmute(B) };
let _: &mut str = unsafe { std::mem::transmute(mb) };
const _: &str = unsafe { std::mem::transmute(B) };
}
fn main() {}