mirror of https://github.com/rust-lang/rust
26 lines
871 B
Rust
26 lines
871 B
Rust
// EMIT_MIR_FOR_EACH_PANIC_STRATEGY
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// This attempts to modify `x.1` via a pointer derived from `addr_of_mut!(x.0)`.
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// According to Miri, that is UB. However, T-opsem has not finalized that
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// decision and as such we cannot rely on it in optimizations. Consequently,
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// DataflowConstProp must treat the `addr_of_mut!(x.0)` as potentially being
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// used to modify `x.1` - if it did not, then it might incorrectly assume that it
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// can infer the value of `x.1` at the end of this function.
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//@ test-mir-pass: DataflowConstProp
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// EMIT_MIR sibling_ptr.main.DataflowConstProp.diff
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// CHECK-LABEL: fn main(
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fn main() {
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// CHECK: debug x1 => [[x1:_.*]];
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let mut x: (u8, u8) = (0, 0);
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unsafe {
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let p = std::ptr::addr_of_mut!(x.0);
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*p.add(1) = 1;
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}
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// CHECK: [[x1]] = copy ({{_.*}}.1: u8);
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let x1 = x.1; // should not be propagated
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}
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