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//! Implementation of `errno` functionality for WASI.
//!
//! Adapted from `unix.rs`.
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use core::str;
use libc::{self, c_int, size_t, strerror_r, strlen};
use crate::Errno;
fn from_utf8_lossy(input: &[u8]) -> &str {
match str::from_utf8(input) {
Ok(valid) => valid,
Err(error) => unsafe { str::from_utf8_unchecked(&input[..error.valid_up_to()]) },
}
}
pub fn with_description<F, T>(err: Errno, callback: F) -> T
where
F: FnOnce(Result<&str, Errno>) -> T,
{
let mut buf = [0u8; 1024];
let c_str = unsafe {
let rc = strerror_r(err.0, buf.as_mut_ptr() as *mut _, buf.len() as size_t);
if rc != 0 {
let fm_err = Errno(rc);
if fm_err != Errno(libc::ERANGE) {
return callback(Err(fm_err));
}
}
let c_str_len = strlen(buf.as_ptr() as *const _);
&buf[..c_str_len]
};
callback(Ok(from_utf8_lossy(c_str)))
}
pub const STRERROR_NAME: &str = "strerror_r";
pub fn errno() -> Errno {
unsafe { Errno(*__errno_location()) }
}
pub fn set_errno(Errno(new_errno): Errno) {
unsafe {
*__errno_location() = new_errno;
}
}
extern "C" {
fn __errno_location() -> *mut c_int;
}