1 // General test of maybe_uninits state computed by MIR dataflow.
3 #![feature(core_intrinsics, rustc_attrs)]
5 use std::intrinsics::rustc_peek;
6 use std::mem::{drop, replace};
10 #[rustc_mir(rustc_peek_definite_init,stop_after_dataflow)]
11 fn foo(test: bool, x: &mut S, y: S, mut z: S) -> S {
13 // `ret` starts off uninitialized
14 rustc_peek(&ret); //~ ERROR rustc_peek: bit not set
16 // All function formal parameters start off initialized.
23 ::std::mem::replace(x, y)
29 // `z` may be uninitialized here.
30 rustc_peek(&z); //~ ERROR rustc_peek: bit not set
32 // `y` is definitely uninitialized here.
33 rustc_peek(&y); //~ ERROR rustc_peek: bit not set
35 // `x` is still (definitely) initialized (replace above is a reborrow).
40 // `x` is *definitely* uninitialized here
41 rustc_peek(&x); //~ ERROR rustc_peek: bit not set
43 // `ret` is now definitely initialized (via `if` above).
49 foo(true, &mut S(13), S(14), S(15));
50 foo(false, &mut S(13), S(14), S(15));