src/test/compile-fail/pushpop-unsafe-rejects.rs

   1 // Copyright 2012 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 // Basic sanity check for `push_unsafe!(EXPR)` and
  12 // `pop_unsafe!(EXPR)`: we can call unsafe code when there are a
  13 // positive number of pushes in the stack, or if we are within a
  14 // normal `unsafe` block, but otherwise cannot.
  15
  16 #![feature(pushpop_unsafe)]
  17
  18 static mut X: i32 = 0;
  19
  20 unsafe fn f() { X += 1; return; }
  21 fn g() { unsafe { X += 1_000; } return; }
  22
  23 fn main() {
  24     push_unsafe!( {
  25         f(); pop_unsafe!({
  26             f() //~ ERROR: call to unsafe function
  27         })
  28     } );
  29
  30     push_unsafe!({
  31         f();
  32         pop_unsafe!({
  33             g();
  34             f(); //~ ERROR: call to unsafe function
  35         })
  36     } );
  37
  38     push_unsafe!({
  39         g(); pop_unsafe!({
  40             unsafe {
  41                 f();
  42             }
  43             f(); //~ ERROR: call to unsafe function
  44         })
  45     });
  46
  47
  48     // Note: For implementation simplicity the compiler just
  49     // ICE's if you underflow the push_unsafe stack.
  50     //
  51     // Thus all of the following cases cause an ICE.
  52     //
  53     // (The "ERROR" notes are from an earlier version
  54     //  that used saturated arithmetic rather than checked
  55     //  arithmetic.)
  56
  57     //    pop_unsafe!{ g() };
  58     //
  59     //    push_unsafe!({
  60     //        pop_unsafe!(pop_unsafe!{ g() })
  61     //    });
  62     //
  63     //    push_unsafe!({
  64     //        g();
  65     //        pop_unsafe!(pop_unsafe!({
  66     //            f() // ERROR: call to unsafe function
  67     //        }))
  68     //    });
  69     //
  70     //    pop_unsafe!({
  71     //        f(); // ERROR: call to unsafe function
  72     //    })
  73
  74 }