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56 lines
1.3 KiB
Rust
56 lines
1.3 KiB
Rust
// General test of maybe_inits state computed by MIR dataflow.
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#![feature(core_intrinsics, rustc_attrs)]
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use std::intrinsics::rustc_peek;
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use std::mem::{drop, replace};
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struct S(i32);
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#[rustc_mir(rustc_peek_maybe_init,stop_after_dataflow)]
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fn foo(test: bool, x: &mut S, y: S, mut z: S) -> S {
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let ret;
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// `ret` starts off uninitialized, so we get an error report here.
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rustc_peek(&ret); //~ ERROR rustc_peek: bit not set
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// All function formal parameters start off initialized.
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rustc_peek(&x);
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rustc_peek(&y);
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rustc_peek(&z);
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ret = if test {
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::std::mem::replace(x, y)
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} else {
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z = y;
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z
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};
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// `z` may be initialized here.
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rustc_peek(&z);
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// `y` is definitely uninitialized here.
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rustc_peek(&y); //~ ERROR rustc_peek: bit not set
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// `x` is still (definitely) initialized (replace above is a reborrow).
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rustc_peek(&x);
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::std::mem::drop(x);
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// `x` is *definitely* uninitialized here
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rustc_peek(&x); //~ ERROR rustc_peek: bit not set
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// `ret` is now definitely initialized (via `if` above).
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rustc_peek(&ret);
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ret
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}
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fn main() {
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foo(true, &mut S(13), S(14), S(15));
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foo(false, &mut S(13), S(14), S(15));
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}
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//~? ERROR stop_after_dataflow ended compilation
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