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Imported Upstream version 1.9.0+dfsg1
[rustc.git] / src / test / run-pass / variadic-ffi.rs
1 // Copyright 2013 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 // ignore-msvc -- sprintf isn't a symbol in msvcrt? maybe a #define?
12
13 #![feature(libc, std_misc)]
14
15 extern crate libc;
16
17 use std::ffi::{CStr, CString};
18 use libc::{c_char, c_int};
19
20
21 extern {
22 fn sprintf(s: *mut c_char, format: *const c_char, ...) -> c_int;
23 }
24
25 unsafe fn check<T, F>(expected: &str, f: F) where F: FnOnce(*mut c_char) -> T {
26 let mut x = [0 as c_char; 50];
27 f(&mut x[0] as *mut c_char);
28 assert_eq!(expected.as_bytes(), CStr::from_ptr(x.as_ptr()).to_bytes());
29 }
30
31 pub fn main() {
32
33 unsafe {
34 // Call with just the named parameter
35 let c = CString::new(&b"Hello World\n"[..]).unwrap();
36 check("Hello World\n", |s| sprintf(s, c.as_ptr()));
37
38 // Call with variable number of arguments
39 let c = CString::new(&b"%d %f %c %s\n"[..]).unwrap();
40 check("42 42.500000 a %d %f %c %s\n\n", |s| {
41 sprintf(s, c.as_ptr(), 42, 42.5f64, 'a' as c_int, c.as_ptr());
42 });
43
44 // Make a function pointer
45 let x: unsafe extern fn(*mut c_char, *const c_char, ...) -> c_int = sprintf;
46
47 // A function that takes a function pointer
48 unsafe fn call(fp: unsafe extern fn(*mut c_char, *const c_char, ...) -> c_int) {
49 // Call with just the named parameter
50 let c = CString::new(&b"Hello World\n"[..]).unwrap();
51 check("Hello World\n", |s| fp(s, c.as_ptr()));
52
53 // Call with variable number of arguments
54 let c = CString::new(&b"%d %f %c %s\n"[..]).unwrap();
55 check("42 42.500000 a %d %f %c %s\n\n", |s| {
56 fp(s, c.as_ptr(), 42, 42.5f64, 'a' as c_int, c.as_ptr());
57 });
58 }
59
60 // Pass sprintf directly
61 call(sprintf);
62
63 // Pass sprintf indirectly
64 call(x);
65 }
66
67 }