64 lines
1.8 KiB
Rust
64 lines
1.8 KiB
Rust
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
|
|
// file at the top-level directory of this distribution and at
|
|
// http://rust-lang.org/COPYRIGHT.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
|
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
|
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
|
// option. This file may not be copied, modified, or distributed
|
|
// except according to those terms.
|
|
|
|
// General test of maybe_uninits state computed by MIR dataflow.
|
|
|
|
#![feature(rustc_attrs)]
|
|
#![feature(stmt_expr_attributes)]
|
|
|
|
use std::intrinsics::rustc_peek;
|
|
use std::mem::{drop, replace};
|
|
|
|
struct S(i32);
|
|
|
|
#[rustc_mir_borrowck]
|
|
#[rustc_mir(rustc_peek_maybe_uninit,stop_after_dataflow)]
|
|
fn foo(test: bool, x: &mut S, y: S, mut z: S) -> S {
|
|
let ret;
|
|
// `ret` starts off uninitialized
|
|
unsafe { rustc_peek(&ret); }
|
|
|
|
// All function formal parameters start off initialized.
|
|
|
|
unsafe { rustc_peek(&x) }; //~ ERROR rustc_peek: bit not set
|
|
unsafe { rustc_peek(&y) }; //~ ERROR rustc_peek: bit not set
|
|
unsafe { rustc_peek(&z) }; //~ ERROR rustc_peek: bit not set
|
|
|
|
ret = if test {
|
|
::std::mem::replace(x, y)
|
|
} else {
|
|
z = y;
|
|
z
|
|
};
|
|
|
|
// `z` may be uninitialized here.
|
|
unsafe { rustc_peek(&z); }
|
|
|
|
// `y` is definitely uninitialized here.
|
|
unsafe { rustc_peek(&y); }
|
|
|
|
// `x` is still (definitely) initialized (replace above is a reborrow).
|
|
unsafe { rustc_peek(&x); } //~ ERROR rustc_peek: bit not set
|
|
|
|
::std::mem::drop(x);
|
|
|
|
// `x` is *definitely* uninitialized here
|
|
unsafe { rustc_peek(&x); }
|
|
|
|
// `ret` is now definitely initialized (via `if` above).
|
|
unsafe { rustc_peek(&ret); } //~ ERROR rustc_peek: bit not set
|
|
|
|
ret
|
|
}
|
|
fn main() {
|
|
foo(true, &mut S(13), S(14), S(15));
|
|
foo(false, &mut S(13), S(14), S(15));
|
|
}
|