30 lines
969 B
Rust
30 lines
969 B
Rust
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// run-pass
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// compile-flags: -C debug-assertions
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#![feature(strict_provenance, pointer_is_aligned)]
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#[repr(packed)]
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struct Misaligner {
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_head: u8,
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tail: u64,
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}
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fn main() {
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let memory = [Misaligner { _head: 0, tail: 0}, Misaligner { _head: 0, tail: 0}];
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// Test that we can use addr_of! to get the address of a packed member which according to its
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// type is not aligned, but because it is a projection from a packed type is a valid place.
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let ptr0 = std::ptr::addr_of!(memory[0].tail);
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let ptr1 = std::ptr::addr_of!(memory[0].tail);
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// Even if ptr0 happens to be aligned by chance, ptr1 is not.
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assert!(!ptr0.is_aligned() || !ptr1.is_aligned());
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// And also test that we can get the addr of a packed struct then do a member read from it.
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unsafe {
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let ptr = std::ptr::addr_of!(memory[0]);
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let _tail = (*ptr).tail;
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let ptr = std::ptr::addr_of!(memory[1]);
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let _tail = (*ptr).tail;
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}
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}
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