Vendor things

third-party/vendor/rustix/src/io/errno.rs

@@ -0,0 +1,72 @@
+//! The `Errno` type, which is a minimal wrapper around an error code.
+//!
+//! We define the error constants as individual `const`s instead of an enum
+//! because we may not know about all of the host's error values and we don't
+//! want unrecognized values to create undefined behavior.
+
+use crate::backend;
+use core::{fmt, result};
+#[cfg(feature = "std")]
+use std::error;
+
+/// A specialized [`Result`] type for `rustix` APIs.
+pub type Result<T> = result::Result<T, Errno>;
+
+pub use backend::io::errno::Errno;
+
+impl Errno {
+    /// Shorthand for `std::io::Error::from(self).kind()`.
+    #[cfg(feature = "std")]
+    #[inline]
+    pub fn kind(self) -> std::io::ErrorKind {
+        std::io::Error::from(self).kind()
+    }
+}
+
+impl fmt::Display for Errno {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        #[cfg(feature = "std")]
+        {
+            std::io::Error::from(*self).fmt(fmt)
+        }
+        #[cfg(not(feature = "std"))]
+        {
+            write!(fmt, "os error {}", self.raw_os_error())
+        }
+    }
+}
+
+impl fmt::Debug for Errno {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        #[cfg(feature = "std")]
+        {
+            std::io::Error::from(*self).fmt(fmt)
+        }
+        #[cfg(not(feature = "std"))]
+        {
+            write!(fmt, "os error {}", self.raw_os_error())
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl error::Error for Errno {}
+
+#[cfg(feature = "std")]
+impl From<Errno> for std::io::Error {
+    #[inline]
+    fn from(err: Errno) -> Self {
+        Self::from_raw_os_error(err.raw_os_error() as _)
+    }
+}
+
+/// Call `f` until it either succeeds or fails other than [`Errno::INTR`].
+#[inline]
+pub fn retry_on_intr<T, F: FnMut() -> Result<T>>(mut f: F) -> Result<T> {
+    loop {
+        match f() {
+            Err(Errno::INTR) => (),
+            result => return result,
+        }
+    }
+}