mirror of https://github.com/rust-lang/rust.git
33 lines
764 B
Rust
33 lines
764 B
Rust
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#![feature(core_intrinsics, rustc_attrs)]
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use std::intrinsics::rustc_peek;
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#[rustc_mir(rustc_peek_liveness, stop_after_dataflow)]
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fn foo() {
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{
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let mut x: (i32, i32) = (42, 0);
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// Assignment to a projection does not cause `x` to become live
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unsafe { rustc_peek(x); } //~ ERROR bit not set
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x.1 = 42;
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x = (0, 42);
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// ...but a read from a projection does.
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unsafe { rustc_peek(x); }
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println!("{}", x.1);
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}
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{
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let mut x = 42;
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// Derefs are treated like a read of a local even if they are on the LHS of an assignment.
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let p = &mut x;
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unsafe { rustc_peek(&p); }
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*p = 24;
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unsafe { rustc_peek(&p); } //~ ERROR bit not set
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}
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}
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fn main() {}
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