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52 lines
1.6 KiB
Rust
52 lines
1.6 KiB
Rust
//! Test casts for alignment issues
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#![feature(rustc_private)]
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#![feature(core_intrinsics)]
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extern crate libc;
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#[warn(clippy::cast_ptr_alignment)]
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#[allow(
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clippy::no_effect,
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clippy::unnecessary_operation,
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clippy::cast_lossless,
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clippy::borrow_as_ptr
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)]
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fn main() {
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/* These should be warned against */
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// cast to more-strictly-aligned type
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(&1u8 as *const u8) as *const u16;
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(&mut 1u8 as *mut u8) as *mut u16;
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// cast to more-strictly-aligned type, but with the `pointer::cast` function.
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(&1u8 as *const u8).cast::<u16>();
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(&mut 1u8 as *mut u8).cast::<u16>();
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/* These should be ok */
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// not a pointer type
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1u8 as u16;
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// cast to less-strictly-aligned type
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(&1u16 as *const u16) as *const u8;
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(&mut 1u16 as *mut u16) as *mut u8;
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// For c_void, we should trust the user. See #2677
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(&1u32 as *const u32 as *const std::os::raw::c_void) as *const u32;
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(&1u32 as *const u32 as *const libc::c_void) as *const u32;
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// For ZST, we should trust the user. See #4256
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(&1u32 as *const u32 as *const ()) as *const u32;
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// Issue #2881
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let mut data = [0u8, 0u8];
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unsafe {
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let ptr = &data as *const [u8; 2] as *const u8;
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let _ = (ptr as *const u16).read_unaligned();
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let _ = core::ptr::read_unaligned(ptr as *const u16);
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let _ = core::intrinsics::unaligned_volatile_load(ptr as *const u16);
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let ptr = &mut data as *mut [u8; 2] as *mut u8;
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(ptr as *mut u16).write_unaligned(0);
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core::ptr::write_unaligned(ptr as *mut u16, 0);
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core::intrinsics::unaligned_volatile_store(ptr as *mut u16, 0);
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}
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}
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