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

use crate::{Category, MessageBuf, ErrorCode};

use core::{ptr, ffi, str};

/// Posix error category, suitable for all environments.
///
/// In presence of OS, it means it identifies POSIX error codes.
pub static POSIX_CATEGORY: Category = Category {
    name: "PosixError",
    message,
    equivalent,
    is_would_block,
};

fn equivalent(code: ffi::c_int, other: &ErrorCode) -> bool {
    ptr::eq(&POSIX_CATEGORY, other.category()) && code == other.raw_code()
}

pub(crate) fn get_last_error() -> ffi::c_int {
    #[cfg(not(any(target_os = "wasi", target_os = "cloudabi", target_os = "unknown")))]
    {
        extern {
            #[cfg(not(target_os = "dragonfly"))]
            #[cfg_attr(any(target_os = "macos", target_os = "ios", target_os = "freebsd"), link_name = "__error")]
            #[cfg_attr(
                any(
                    target_os = "openbsd",
                    target_os = "netbsd",
                    target_os = "bitrig",
                    target_os = "android",
                    target_os = "espidf"
                ),
                link_name = "__errno"
            )]
            #[cfg_attr(
                any(target_os = "solaris", target_os = "illumos"),
                link_name = "___errno"
            )]
            #[cfg_attr(target_os = "haiku", link_name = "_errnop")]
            #[cfg_attr(
                any(target_os = "linux", target_os = "hurd", target_os = "redox"),
                link_name = "__errno_location"
            )]
            #[cfg_attr(target_os = "aix", link_name = "_Errno")]
            #[cfg_attr(target_os = "nto", link_name = "__get_errno_ptr")]
            #[cfg_attr(target_os = "windows", link_name = "_errno")]
            fn errno_location() -> *mut ffi::c_int;
        }

        return unsafe {
            *(errno_location())
        }
    }

    #[cfg(any(target_os = "cloudabi", target_os = "wasi"))]
    {
        extern {
            #[thread_local]
            static errno: ffi::c_int;
        }

        return errno;
    }

    #[cfg(target_os = "vxworks")]
    {
        extern "C" {
            pub fn errnoGet() -> ffi::c_int;
        }

        return unsafe {
            errnoGet();
        }
    }

    #[cfg(target_os = "unknown")]
    {
        return 0;
    }
}

pub(crate) fn message(_code: ffi::c_int, _out: &mut MessageBuf) -> &str {
    #[cfg(any(windows, all(unix, not(target_env = "gnu"))))]
    extern "C" {
        ///Only GNU impl is thread unsafe
        fn strerror(code: ffi::c_int) -> *const i8;
        fn strlen(text: *const i8) -> usize;
    }

    #[cfg(all(unix, target_env = "gnu"))]
    extern "C" {
        fn strerror_l(code: ffi::c_int, locale: *mut i8) -> *const i8;
        fn strlen(text: *const i8) -> usize;
    }

    #[cfg(all(unix, target_env = "gnu"))]
    #[inline]
    unsafe fn strerror(code: ffi::c_int) -> *const i8 {
        strerror_l(code, ptr::null_mut())
    }

    #[cfg(any(windows, unix))]
    {
        let err = unsafe {
            strerror(_code)
        };

        if !err.is_null() {
            let err_len = unsafe {
                strlen(err)
            };
            let err_slice = unsafe {
                ptr::copy_nonoverlapping(err as *const u8, _out.as_mut_ptr() as *mut u8, err_len);
                core::slice::from_raw_parts(_out.as_ptr() as *const u8, err_len)
            };

            match str::from_utf8(err_slice) {
                Ok(msg) => return msg,
                Err(_) => return crate::FAIL_ERROR_FORMAT,
            };
        }
    }

    crate::UNKNOWN_ERROR
}

#[cfg(not(any(windows, unix)))]
const fn is_would_block(_: ffi::c_int) -> bool {
    false
}

#[cfg(any(windows, unix))]
pub(crate) const fn is_would_block(code: ffi::c_int) -> bool {
    code == libc::EWOULDBLOCK || code == libc::EAGAIN
}