New upstream version 1.52.1+dfsg1

[rustc.git] / src / tools / clippy / tests / ui / size_of_in_element_count / expressions.rs

#![warn(clippy::size_of_in_element_count)]
#![allow(clippy::ptr_offset_with_cast)]

use std::mem::{size_of, size_of_val};
use std::ptr::{copy, copy_nonoverlapping, write_bytes};

fn main() {
    const SIZE: usize = 128;
    const HALF_SIZE: usize = SIZE / 2;
    const DOUBLE_SIZE: usize = SIZE * 2;
    let mut x = [2u8; SIZE];
    let mut y = [2u8; SIZE];

    // Count expression involving multiplication of size_of (Should trigger the lint)
    unsafe { copy_nonoverlapping(x.as_ptr(), y.as_mut_ptr(), size_of::<u8>() * SIZE) };

    // Count expression involving nested multiplications of size_of (Should trigger the lint)
    unsafe { copy_nonoverlapping(x.as_ptr(), y.as_mut_ptr(), HALF_SIZE * size_of_val(&x[0]) * 2) };

    // Count expression involving divisions of size_of (Should trigger the lint)
    unsafe { copy(x.as_ptr(), y.as_mut_ptr(), DOUBLE_SIZE * size_of::<u8>() / 2) };

    // Count expression involving divisions by size_of (Should not trigger the lint)
    unsafe { copy(x.as_ptr(), y.as_mut_ptr(), DOUBLE_SIZE / size_of::<u8>()) };

    // Count expression involving divisions by multiple size_of (Should not trigger the lint)
    unsafe { copy(x.as_ptr(), y.as_mut_ptr(), DOUBLE_SIZE / (2 * size_of::<u8>())) };

    // Count expression involving recursive divisions by size_of (Should trigger the lint)
    unsafe { copy(x.as_ptr(), y.as_mut_ptr(), DOUBLE_SIZE / (2 / size_of::<u8>())) };

    // No size_of calls (Should not trigger the lint)
    unsafe { copy(x.as_ptr(), y.as_mut_ptr(), SIZE) };

    // Different types for pointee and size_of (Should not trigger the lint)
    unsafe { y.as_mut_ptr().write_bytes(0u8, size_of::<u16>() / 2 * SIZE) };
}