// 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 or the MIT license // , 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(x: &mut S) { // `x` is initialized here, so maybe-uninit bit is 0. unsafe { *rustc_peek(&x) }; //~ ERROR rustc_peek: bit not set ::std::mem::drop(x); // `x` definitely uninitialized here, so maybe-uninit bit is 1. unsafe { rustc_peek(&x) }; } fn main() { foo(&mut S(13)); foo(&mut S(13)); }