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use super::{abi, WORD_SIZE};
use crate::ffi::OsString;
use crate::fmt;
use crate::sys::os_str;
use crate::sys_common::FromInner;
pub struct Args {
i_forward: usize,
i_back: usize,
count: usize,
}
pub fn args() -> Args {
let count = unsafe { abi::sys_argc() };
Args { i_forward: 0, i_back: 0, count }
}
impl Args {
/// Use sys_argv to get the arg at the requested index. Does not check that i is less than argc
/// and will not return if the index is out of bounds.
fn argv(i: usize) -> OsString {
let arg_len = unsafe { abi::sys_argv(crate::ptr::null_mut(), 0, i) };
let arg_len_words = (arg_len + WORD_SIZE - 1) / WORD_SIZE;
let words = unsafe { abi::sys_alloc_words(arg_len_words) };
let arg_len2 = unsafe { abi::sys_argv(words, arg_len_words, i) };
debug_assert_eq!(arg_len, arg_len2);
// Convert to OsString.
//
// FIXME: We can probably get rid of the extra copy here if we
// reimplement "os_str" instead of just using the generic unix
// "os_str".
let arg_bytes: &[u8] =
unsafe { crate::slice::from_raw_parts(words.cast() as *const u8, arg_len) };
OsString::from_inner(os_str::Buf { inner: arg_bytes.to_vec() })
}
}
impl fmt::Debug for Args {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().finish()
}
}
impl Iterator for Args {
type Item = OsString;
fn next(&mut self) -> Option<OsString> {
if self.i_forward >= self.count - self.i_back {
None
} else {
let arg = Self::argv(self.i_forward);
self.i_forward += 1;
Some(arg)
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
(self.count, Some(self.count))
}
}
impl ExactSizeIterator for Args {
fn len(&self) -> usize {
self.count
}
}
impl DoubleEndedIterator for Args {
fn next_back(&mut self) -> Option<OsString> {
if self.i_back >= self.count - self.i_forward {
None
} else {
let arg = Self::argv(self.count - 1 - self.i_back);
self.i_back += 1;
Some(arg)
}
}
}
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