1//! Implementation of `errno` functionality for Unix systems.
2//!
3//! Adapted from `src/libstd/sys/unix/os.rs` in the Rust distribution.
4
5// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
6// file at the top-level directory of this distribution and at
7// http://rust-lang.org/COPYRIGHT.
8//
9// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
10// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
11// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
12// option. This file may not be copied, modified, or distributed
13// except according to those terms.
14
15use core::str;
16use libc::{self, c_int, size_t, strerror_r, strlen};
17
18use crate::Errno;
19
20fn from_utf8_lossy(input: &[u8]) -> &str {
21 match str::from_utf8(input) {
22 Ok(valid: &str) => valid,
23 Err(error: Utf8Error) => unsafe { str::from_utf8_unchecked(&input[..error.valid_up_to()]) },
24 }
25}
26
27pub fn with_description<F, T>(err: Errno, callback: F) -> T
28where
29 F: FnOnce(Result<&str, Errno>) -> T,
30{
31 let mut buf: [u8; 1024] = [0u8; 1024];
32 let c_str: &[u8] = unsafe {
33 let rc: i32 = strerror_r(errnum:err.0, buf.as_mut_ptr() as *mut _, buflen:buf.len() as size_t);
34 if rc != 0 {
35 // Handle negative return codes for compatibility with glibc < 2.13
36 let fm_err: Errno = match rc < 0 {
37 true => errno(),
38 false => Errno(rc),
39 };
40 if fm_err != Errno(libc::ERANGE) {
41 return callback(Err(fm_err));
42 }
43 }
44 let c_str_len: usize = strlen(cs:buf.as_ptr() as *const _);
45 &buf[..c_str_len]
46 };
47 callback(Ok(from_utf8_lossy(input:c_str)))
48}
49
50pub const STRERROR_NAME: &str = "strerror_r";
51
52pub fn errno() -> Errno {
53 unsafe { Errno(*errno_location()) }
54}
55
56pub fn set_errno(Errno(errno: i32): Errno) {
57 unsafe {
58 *errno_location() = errno;
59 }
60}
61
62unsafeextern "C" {
63 #[cfg_attr(
64 any(
65 target_os = "macos",
66 target_os = "ios",
67 target_os = "tvos",
68 target_os = "watchos",
69 target_os = "visionos",
70 target_os = "freebsd"
71 ),
72 link_name = "__error"
73 )]
74 #[cfg_attr(
75 any(
76 target_os = "openbsd",
77 target_os = "netbsd",
78 target_os = "android",
79 target_os = "espidf",
80 target_env = "newlib"
81 ),
82 link_name = "__errno"
83 )]
84 #[cfg_attr(
85 any(target_os = "solaris", target_os = "illumos"),
86 link_name = "___errno"
87 )]
88 #[cfg_attr(target_os = "haiku", link_name = "_errnop")]
89 #[cfg_attr(
90 any(
91 target_os = "linux",
92 target_os = "hurd",
93 target_os = "redox",
94 target_os = "dragonfly",
95 target_os = "emscripten",
96 ),
97 link_name = "__errno_location"
98 )]
99 #[cfg_attr(target_os = "aix", link_name = "_Errno")]
100 #[cfg_attr(target_os = "nto", link_name = "__get_errno_ptr")]
101 unsafefn errno_location() -> *mut c_int;
102}
103