src/test/run-pass/extern/extern-call-scrub.rs

   1 // run-pass
   2 #![allow(unused_must_use)]
   3 // This time we're testing repeatedly going up and down both stacks to
   4 // make sure the stack pointers are maintained properly in both
   5 // directions
   6
   7 // ignore-emscripten no threads support
   8
   9 #![feature(rustc_private)]
  10
  11 extern crate libc;
  12 use std::thread;
  13
  14 mod rustrt {
  15     extern crate libc;
  16
  17     #[link(name = "rust_test_helpers", kind = "static")]
  18     extern {
  19         pub fn rust_dbg_call(cb: extern "C" fn(libc::uintptr_t) -> libc::uintptr_t,
  20                              data: libc::uintptr_t)
  21                              -> libc::uintptr_t;
  22     }
  23 }
  24
  25 extern fn cb(data: libc::uintptr_t) -> libc::uintptr_t {
  26     if data == 1 {
  27         data
  28     } else {
  29         count(data - 1) + count(data - 1)
  30     }
  31 }
  32
  33 fn count(n: libc::uintptr_t) -> libc::uintptr_t {
  34     unsafe {
  35         println!("n = {}", n);
  36         rustrt::rust_dbg_call(cb, n)
  37     }
  38 }
  39
  40 pub fn main() {
  41     // Make sure we're on a thread with small Rust stacks (main currently
  42     // has a large stack)
  43     thread::spawn(move|| {
  44         let result = count(12);
  45         println!("result = {}", result);
  46         assert_eq!(result, 2048);
  47     }).join();
  48 }