1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171

// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//! Global storage for command line arguments
//!
//! The current incarnation of the Rust runtime expects for
//! the processes `argc` and `argv` arguments to be stored
//! in a globally-accessible location for use by the `os` module.
//!
//! Only valid to call on linux. Mac and Windows use syscalls to
//! discover the command line arguments.
//!
//! FIXME #7756: Would be nice for this to not exist.

use core::prelude::*;
use collections::vec::Vec;

/// One-time global initialization.
pub unsafe fn init(argc: int, argv: **u8) { imp::init(argc, argv) }

/// One-time global cleanup.
pub unsafe fn cleanup() { imp::cleanup() }

/// Take the global arguments from global storage.
pub fn take() -> Option<Vec<Vec<u8>>> { imp::take() }

/// Give the global arguments to global storage.
///
/// It is an error if the arguments already exist.
pub fn put(args: Vec<Vec<u8>>) { imp::put(args) }

/// Make a clone of the global arguments.
pub fn clone() -> Option<Vec<Vec<u8>>> { imp::clone() }

#[cfg(target_os = "linux")]
#[cfg(target_os = "android")]
#[cfg(target_os = "freebsd")]
mod imp {
    use core::prelude::*;

    use alloc::owned::Box;
    use collections::vec::Vec;
    use core::mem;
    use core::slice;

    use mutex::{StaticNativeMutex, NATIVE_MUTEX_INIT};

    static mut global_args_ptr: uint = 0;
    static mut lock: StaticNativeMutex = NATIVE_MUTEX_INIT;

    pub unsafe fn init(argc: int, argv: **u8) {
        let args = load_argc_and_argv(argc, argv);
        put(args);
    }

    pub unsafe fn cleanup() {
        rtassert!(take().is_some());
        lock.destroy();
    }

    pub fn take() -> Option<Vec<Vec<u8>>> {
        with_lock(|| unsafe {
            let ptr = get_global_ptr();
            let val = mem::replace(&mut *ptr, None);
            val.as_ref().map(|s: &Box<Vec<Vec<u8>>>| (**s).clone())
        })
    }

    pub fn put(args: Vec<Vec<u8>>) {
        with_lock(|| unsafe {
            let ptr = get_global_ptr();
            rtassert!((*ptr).is_none());
            (*ptr) = Some(box args.clone());
        })
    }

    pub fn clone() -> Option<Vec<Vec<u8>>> {
        with_lock(|| unsafe {
            let ptr = get_global_ptr();
            (*ptr).as_ref().map(|s: &Box<Vec<Vec<u8>>>| (**s).clone())
        })
    }

    fn with_lock<T>(f: || -> T) -> T {
        unsafe {
            let _guard = lock.lock();
            f()
        }
    }

    fn get_global_ptr() -> *mut Option<Box<Vec<Vec<u8>>>> {
        unsafe { mem::transmute(&global_args_ptr) }
    }

    unsafe fn load_argc_and_argv(argc: int, argv: **u8) -> Vec<Vec<u8>> {
        Vec::from_fn(argc as uint, |i| {
            let base = *argv.offset(i as int);
            let mut len = 0;
            while *base.offset(len) != 0 { len += 1; }
            slice::raw::buf_as_slice(base, len as uint, |slice| {
                Vec::from_slice(slice)
            })
        })
    }

    #[cfg(test)]
    mod tests {
        use std::prelude::*;
        use std::finally::Finally;

        use super::*;

        #[test]
        fn smoke_test() {
            // Preserve the actual global state.
            let saved_value = take();

            let expected = vec![
                Vec::from_slice(b"happy"),
                Vec::from_slice(b"today?"),
            ];

            put(expected.clone());
            assert!(clone() == Some(expected.clone()));
            assert!(take() == Some(expected.clone()));
            assert!(take() == None);

            (|| {
            }).finally(|| {
                // Restore the actual global state.
                match saved_value {
                    Some(ref args) => put(args.clone()),
                    None => ()
                }
            })
        }
    }
}

#[cfg(target_os = "macos")]
#[cfg(target_os = "ios")]
#[cfg(target_os = "win32")]
mod imp {
    use core::prelude::*;
    use collections::vec::Vec;

    pub unsafe fn init(_argc: int, _argv: **u8) {
    }

    pub fn cleanup() {
    }

    pub fn take() -> Option<Vec<Vec<u8>>> {
        fail!()
    }

    pub fn put(_args: Vec<Vec<u8>>) {
        fail!()
    }

    pub fn clone() -> Option<Vec<Vec<u8>>> {
        fail!()
    }
}