src/test/compile-fail/dep-graph-assoc-type-trans.rs

   1 // Copyright 2012-2014 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 // Test that when a trait impl changes, fns whose body uses that trait
  12 // must also be recompiled.
  13
  14 // compile-flags: -Z query-dep-graph
  15
  16 #![feature(rustc_attrs)]
  17 #![allow(warnings)]
  18
  19 fn main() { }
  20
  21 pub trait Foo: Sized {
  22     type T;
  23     fn method(self) { }
  24 }
  25
  26 mod x {
  27     use Foo;
  28
  29     #[rustc_if_this_changed]
  30     impl Foo for char { type T = char; }
  31
  32     impl Foo for u32 { type T = u32; }
  33 }
  34
  35 mod y {
  36     use Foo;
  37
  38     #[rustc_then_this_would_need(TypeckItemBody)] //~ ERROR OK
  39     #[rustc_then_this_would_need(TransCrateItem)] //~ ERROR OK
  40     pub fn use_char_assoc() {
  41         // Careful here: in the representation, <char as Foo>::T gets
  42         // normalized away, so at a certain point we had no edge to
  43         // trans.  (But now trans just depends on typeck.)
  44         let x: <char as Foo>::T = 'a';
  45     }
  46
  47     pub fn take_foo<T:Foo>(t: T) { }
  48 }