1 //! The `Errno` type, which is a minimal wrapper around an error code.
2 //!
3 //! We define the error constants as individual `const`s instead of an enum
4 //! because we may not know about all of the host's error values and we don't
5 //! want unrecognized values to create undefined behavior.
6 
7 use crate::backend;
8 use core::{fmt, result};
9 #[cfg(feature = "std")]
10 use std::error;
11 
12 /// A specialized [`Result`] type for `rustix` APIs.
13 pub type Result<T> = result::Result<T, Errno>;
14 
15 pub use backend::io::errno::Errno;
16 
17 impl Errno {
18     /// Shorthand for `std::io::Error::from(self).kind()`.
19     #[cfg(feature = "std")]
20     #[inline]
kind(self) -> std::io::ErrorKind21     pub fn kind(self) -> std::io::ErrorKind {
22         std::io::Error::from(self).kind()
23     }
24 }
25 
26 impl fmt::Display for Errno {
fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result27     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
28         #[cfg(feature = "std")]
29         {
30             std::io::Error::from(*self).fmt(fmt)
31         }
32         #[cfg(not(feature = "std"))]
33         {
34             write!(fmt, "os error {}", self.raw_os_error())
35         }
36     }
37 }
38 
39 impl fmt::Debug for Errno {
fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result40     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
41         #[cfg(feature = "std")]
42         {
43             std::io::Error::from(*self).fmt(fmt)
44         }
45         #[cfg(not(feature = "std"))]
46         {
47             write!(fmt, "os error {}", self.raw_os_error())
48         }
49     }
50 }
51 
52 #[cfg(feature = "std")]
53 impl error::Error for Errno {}
54 
55 #[cfg(feature = "std")]
56 impl From<Errno> for std::io::Error {
57     #[inline]
from(err: Errno) -> Self58     fn from(err: Errno) -> Self {
59         Self::from_raw_os_error(err.raw_os_error() as _)
60     }
61 }
62 
63 /// Call `f` until it either succeeds or fails other than [`Errno::INTR`].
64 #[inline]
retry_on_intr<T, F: FnMut() -> Result<T>>(mut f: F) -> Result<T>65 pub fn retry_on_intr<T, F: FnMut() -> Result<T>>(mut f: F) -> Result<T> {
66     loop {
67         match f() {
68             Err(Errno::INTR) => (),
69             result => return result,
70         }
71     }
72 }
73