src/test/compile-fail/lint-no-drop-on-repr-extern.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // Check we reject structs that mix a `Drop` impl with `#[repr(C)]`.
  12 //
  13 // As a special case, also check that we do not warn on such structs
  14 // if they also are declared with `#[unsafe_no_drop_flag]`
  15
  16 #![feature(unsafe_no_drop_flag)]
  17 #![deny(drop_with_repr_extern)]
  18 //~^ NOTE lint level defined here
  19 //~| NOTE lint level defined here
  20
  21 #[repr(C)] struct As { x: Box<i8> }
  22 #[repr(C)] enum Ae { Ae(Box<i8>), _None }
  23
  24 struct Bs { x: Box<i8> }
  25 enum Be { Be(Box<i8>), _None }
  26
  27 #[repr(C)] struct Cs { x: Box<i8> }
  28 //~^ NOTE the `#[repr(C)]` attribute is attached here
  29
  30 impl Drop for Cs { fn drop(&mut self) { } }
  31 //~^ ERROR implementing Drop adds hidden state to types, possibly conflicting with `#[repr(C)]`
  32
  33 #[repr(C)] enum Ce { Ce(Box<i8>), _None }
  34 //~^ NOTE the `#[repr(C)]` attribute is attached here
  35
  36 impl Drop for Ce { fn drop(&mut self) { } }
  37 //~^ ERROR implementing Drop adds hidden state to types, possibly conflicting with `#[repr(C)]`
  38
  39 #[unsafe_no_drop_flag]
  40 #[repr(C)] struct Ds { x: Box<i8> }
  41
  42 impl Drop for Ds { fn drop(&mut self) { } }
  43
  44 #[unsafe_no_drop_flag]
  45 #[repr(C)] enum De { De(Box<i8>), _None }
  46
  47 impl Drop for De { fn drop(&mut self) { } }
  48
  49 fn main() {
  50     let a = As { x: Box::new(3) };
  51     let b = Bs { x: Box::new(3) };
  52     let c = Cs { x: Box::new(3) };
  53     let d = Ds { x: Box::new(3) };
  54
  55     println!("{:?}", (*a.x, *b.x, *c.x, *d.x));
  56
  57     let _a = Ae::Ae(Box::new(3));
  58     let _b = Be::Be(Box::new(3));
  59     let _c = Ce::Ce(Box::new(3));
  60     let _d = De::De(Box::new(3));
  61 }