66 lines
2.0 KiB
Rust
66 lines
2.0 KiB
Rust
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// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use std::c_str::CString;
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use std::libc::{c_char, c_int};
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extern {
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fn sprintf(s: *mut c_char, format: *c_char, ...) -> c_int;
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}
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unsafe fn check<T>(expected: &str, f: &fn(*mut c_char) -> T) {
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let mut x = [0i8, ..50];
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f(&mut x[0] as *mut c_char);
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let res = CString::new(&x[0], false);
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assert_eq!(expected, res.as_str().unwrap());
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}
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pub fn main() {
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unsafe {
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// Call with just the named parameter
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do "Hello World\n".with_c_str |c| {
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check("Hello World\n", |s| sprintf(s, c));
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}
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// Call with variable number of arguments
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do "%d %f %c %s\n".with_c_str |c| {
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do check("42 42.500000 a %d %f %c %s\n\n") |s| {
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sprintf(s, c, 42i, 42.5f64, 'a' as c_int, c);
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}
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}
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// Make a function pointer
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let x: extern "C" unsafe fn(*mut c_char, *c_char, ...) -> c_int = sprintf;
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// A function that takes a function pointer
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unsafe fn call(p: extern "C" unsafe fn(*mut c_char, *c_char, ...) -> c_int) {
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// Call with just the named parameter via fn pointer
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do "Hello World\n".with_c_str |c| {
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check("Hello World\n", |s| p(s, c));
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}
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// Call with variable number of arguments
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do "%d %f %c %s\n".with_c_str |c| {
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do check("42 42.500000 a %d %f %c %s\n\n") |s| {
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p(s, c, 42i, 42.5f64, 'a' as c_int, c);
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}
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}
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}
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// Pass sprintf directly
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call(sprintf);
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// Pass sprintf indirectly
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call(x);
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}
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}
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