src/test/run-pass/extern-call-deep2.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 #![feature(libc)]
  12
  13 extern crate libc;
  14 use std::thread;
  15
  16 mod rustrt {
  17     extern crate libc;
  18
  19     #[link(name = "rust_test_helpers")]
  20     extern {
  21         pub fn rust_dbg_call(cb: extern "C" fn(libc::uintptr_t) -> libc::uintptr_t,
  22                              data: libc::uintptr_t)
  23                              -> libc::uintptr_t;
  24     }
  25 }
  26
  27 extern fn cb(data: libc::uintptr_t) -> libc::uintptr_t {
  28     if data == 1 {
  29         data
  30     } else {
  31         count(data - 1) + 1
  32     }
  33 }
  34
  35 fn count(n: libc::uintptr_t) -> libc::uintptr_t {
  36     unsafe {
  37         println!("n = {}", n);
  38         rustrt::rust_dbg_call(cb, n)
  39     }
  40 }
  41
  42 pub fn main() {
  43     // Make sure we're on a task with small Rust stacks (main currently
  44     // has a large stack)
  45     thread::spawn(move|| {
  46         let result = count(1000);
  47         println!("result = {}", result);
  48         assert_eq!(result, 1000);
  49     }).join();
  50 }