Peter Limkilde Svendsen
83 lines
2.4 KiB
Rust
83 lines
2.4 KiB
Rust
//! strings implementation for Redox, following http://pubs.opengroup.org/onlinepubs/7908799/xsh/strings.h.html
|
|
|
|
use core::{
|
|
arch,
|
|
iter::{once, zip},
|
|
ptr,
|
|
};
|
|
|
|
use crate::{
|
|
header::{ctype, string},
|
|
iter::NulTerminated,
|
|
platform::types::*,
|
|
};
|
|
|
|
#[no_mangle]
|
|
pub unsafe extern "C" fn bcmp(first: *const c_void, second: *const c_void, n: size_t) -> c_int {
|
|
string::memcmp(first, second, n)
|
|
}
|
|
|
|
#[no_mangle]
|
|
pub unsafe extern "C" fn bcopy(src: *const c_void, dst: *mut c_void, n: size_t) {
|
|
ptr::copy(src as *const u8, dst as *mut u8, n);
|
|
}
|
|
|
|
#[no_mangle]
|
|
pub unsafe extern "C" fn bzero(dst: *mut c_void, n: size_t) {
|
|
ptr::write_bytes(dst as *mut u8, 0, n);
|
|
}
|
|
|
|
#[no_mangle]
|
|
pub unsafe extern "C" fn explicit_bzero(s: *mut c_void, n: size_t) {
|
|
for i in 0..n {
|
|
*(s as *mut u8).add(i) = 0 as u8;
|
|
}
|
|
arch::asm!("");
|
|
}
|
|
|
|
#[no_mangle]
|
|
pub extern "C" fn ffs(i: c_int) -> c_int {
|
|
if i == 0 {
|
|
return 0;
|
|
}
|
|
1 + i.trailing_zeros() as c_int
|
|
}
|
|
|
|
#[no_mangle]
|
|
pub unsafe extern "C" fn index(s: *const c_char, c: c_int) -> *mut c_char {
|
|
string::strchr(s, c)
|
|
}
|
|
|
|
#[no_mangle]
|
|
pub unsafe extern "C" fn rindex(s: *const c_char, c: c_int) -> *mut c_char {
|
|
string::strrchr(s, c)
|
|
}
|
|
|
|
#[no_mangle]
|
|
pub unsafe extern "C" fn strcasecmp(s1: *const c_char, s2: *const c_char) -> c_int {
|
|
// SAFETY: the caller must ensure that s1 and s2 point to nul-terminated buffers.
|
|
let s1_iter = unsafe { NulTerminated::new(s1) }.chain(once(&0));
|
|
let s2_iter = unsafe { NulTerminated::new(s2) }.chain(once(&0));
|
|
|
|
let zipped = zip(s1_iter, s2_iter);
|
|
inner_casecmp(zipped)
|
|
}
|
|
|
|
#[no_mangle]
|
|
pub unsafe extern "C" fn strncasecmp(s1: *const c_char, s2: *const c_char, n: size_t) -> c_int {
|
|
// SAFETY: the caller must ensure that s1 and s2 point to nul-terminated buffers.
|
|
let s1_iter = unsafe { NulTerminated::new(s1) }.chain(once(&0));
|
|
let s2_iter = unsafe { NulTerminated::new(s2) }.chain(once(&0));
|
|
|
|
let zipped = zip(s1_iter, s2_iter).take(n);
|
|
inner_casecmp(zipped)
|
|
}
|
|
|
|
/// Given two zipped `&c_char` iterators, either find the first comparison != 0, or return 0.
|
|
fn inner_casecmp<'a>(iterator: impl Iterator<Item = (&'a c_char, &'a c_char)>) -> c_int {
|
|
let mut cmp_iter =
|
|
iterator.map(|(&c1, &c2)| ctype::tolower(c1.into()) - ctype::tolower(c2.into()));
|
|
let mut skip_iter = cmp_iter.skip_while(|&cmp| cmp == 0);
|
|
skip_iter.next().or(Some(0)).unwrap()
|
|
}
|