28 lines
924 B
Rust
28 lines
924 B
Rust
// compile-flags: -Zmiri-strict-provenance
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#![feature(strict_provenance)]
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use std::mem;
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// This is the example from
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// <https://github.com/rust-lang/unsafe-code-guidelines/issues/286#issuecomment-1085144431>.
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unsafe fn deref(left: *const u8, right: *const u8) {
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let left_int: usize = mem::transmute(left); //~ERROR expected plain (non-pointer) bytes
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let right_int: usize = mem::transmute(right);
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if left_int == right_int {
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// The compiler is allowed to replace `left_int` by `right_int` here...
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let left_ptr: *const u8 = mem::transmute(left_int);
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// ...which however means here it could be dereferencing the wrong pointer.
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let _val = *left_ptr;
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}
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}
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fn main() {
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let ptr1 = &0u8 as *const u8;
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let ptr2 = &1u8 as *const u8;
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unsafe {
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// Two pointers with the same address but different provenance.
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deref(ptr1, ptr2.with_addr(ptr1.addr()));
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}
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}
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