53 lines
1.8 KiB
Rust
53 lines
1.8 KiB
Rust
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// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// compile-flags: -Z borrowck=mir -Z nll
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#![allow(dead_code)]
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// Test that we relate the type of the fn type to the type of the fn
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// ptr when doing a `ReifyFnPointer` cast.
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//
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// This test is a bit tortured, let me explain:
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//
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// The `where 'a: 'a` clause here ensures that `'a` is early bound,
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// which is needed below to ensure that this test hits the path we are
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// concerned with.
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fn foo<'a>(x: &'a u32) -> &'a u32
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where
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'a: 'a,
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{
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panic!()
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}
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fn bar<'a>(x: &'a u32) -> &'static u32 {
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// Here, the type of `foo` is `typeof(foo::<'x>)` for some fresh variable `'x`.
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// During NLL region analysis, this will get renumbered to `typeof(foo::<'?0>)`
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// where `'?0` is a new region variable.
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//
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// (Note that if `'a` on `foo` were early-bound, the type would be
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// `typeof(foo)`, which would interact differently with because
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// the renumbering later.)
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//
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// This type is then coerced to a fn type `fn(&'?1 u32) -> &'?2
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// u32`. Here, the `'?1` and `'?2` will have been created during
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// the NLL region renumbering.
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//
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// The MIR type checker must therefore relate `'?0` to `'?1` and `'?2`
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// as part of checking the `ReifyFnPointer`.
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let f: fn(_) -> _ = foo;
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//~^ WARNING not reporting region error due to -Znll
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f(x)
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//~^ ERROR free region `'_#1r` does not outlive free region `'static`
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}
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fn main() {}
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