Add Unsupported to std::io::ErrorKind

library/std/src/fs/tests.rs

@@ -1329,7 +1329,9 @@ fn metadata_access_times() {
         match (a.created(), b.created()) {
             (Ok(t1), Ok(t2)) => assert!(t1 <= t2),
             (Err(e1), Err(e2))
-                if e1.kind() == ErrorKind::Other && e2.kind() == ErrorKind::Other => {}
+                if e1.kind() == ErrorKind::Other && e2.kind() == ErrorKind::Other
+                    || e1.kind() == ErrorKind::Unsupported
+                        && e2.kind() == ErrorKind::Unsupported => {}
             (a, b) => {
                 panic!("creation time must be always supported or not supported: {:?} {:?}", a, b,)
             }

library/std/src/io/error.rs

@@ -180,6 +180,12 @@ pub enum ErrorKind {
     /// read.
     #[stable(feature = "read_exact", since = "1.6.0")]
     UnexpectedEof,
+
+    /// This operation is unsupported on this platform.
+    ///
+    /// This means that the operation can never succeed.
+    #[stable(feature = "unsupported_error", since = "1.53.0")]
+    Unsupported,
 }
 
 impl ErrorKind {
@@ -203,6 +209,7 @@ impl ErrorKind {
             ErrorKind::Interrupted => "operation interrupted",
             ErrorKind::Other => "other os error",
             ErrorKind::UnexpectedEof => "unexpected end of file",
+            ErrorKind::Unsupported => "unsupported",
         }
     }
 }

library/std/src/sys/hermit/fd.rs

@@ -1,9 +1,10 @@
 #![unstable(reason = "not public", issue = "none", feature = "fd")]
 
-use crate::io::{self, ErrorKind, Read};
+use crate::io::{self, Read};
 use crate::mem;
 use crate::sys::cvt;
 use crate::sys::hermit::abi;
+use crate::sys::unsupported;
 use crate::sys_common::AsInner;
 
 #[derive(Debug)]
@@ -46,19 +47,19 @@ impl FileDesc {
         self.duplicate_path(&[])
     }
     pub fn duplicate_path(&self, _path: &[u8]) -> io::Result<FileDesc> {
-        Err(io::Error::new_const(ErrorKind::Other, &"duplicate isn't supported"))
+        unsupported()
     }
 
     pub fn nonblocking(&self) -> io::Result<bool> {
         Ok(false)
     }
 
     pub fn set_cloexec(&self) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"cloexec isn't supported"))
+        unsupported()
     }
 
     pub fn set_nonblocking(&self, _nonblocking: bool) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"nonblocking isn't supported"))
+        unsupported()
     }
 }
 

library/std/src/sys/hermit/mod.rs

@@ -56,7 +56,7 @@ pub fn unsupported<T>() -> crate::io::Result<T> {
 
 pub fn unsupported_err() -> crate::io::Error {
     crate::io::Error::new_const(
-        crate::io::ErrorKind::Other,
+        crate::io::ErrorKind::Unsupported,
         &"operation not supported on HermitCore yet",
     )
 }

library/std/src/sys/hermit/net.rs

@@ -166,7 +166,7 @@ impl TcpStream {
     }
 
     pub fn socket_addr(&self) -> io::Result<SocketAddr> {
-        Err(io::Error::new_const(ErrorKind::Other, &"socket_addr isn't supported"))
+        unsupported()
     }
 
     pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
@@ -199,7 +199,7 @@ impl TcpStream {
     }
 
     pub fn take_error(&self) -> io::Result<Option<io::Error>> {
-        Err(io::Error::new_const(ErrorKind::Other, &"take_error isn't supported"))
+        unsupported()
     }
 
     pub fn set_nonblocking(&self, mode: bool) -> io::Result<()> {
@@ -247,27 +247,27 @@ impl TcpListener {
     }
 
     pub fn set_ttl(&self, _: u32) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn ttl(&self) -> io::Result<u32> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn set_only_v6(&self, _: bool) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn only_v6(&self) -> io::Result<bool> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn take_error(&self) -> io::Result<Option<io::Error>> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn set_nonblocking(&self, _: bool) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 }
 
@@ -281,127 +281,127 @@ pub struct UdpSocket(abi::Handle);
 
 impl UdpSocket {
     pub fn bind(_: io::Result<&SocketAddr>) -> io::Result<UdpSocket> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn peer_addr(&self) -> io::Result<SocketAddr> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn socket_addr(&self) -> io::Result<SocketAddr> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn recv_from(&self, _: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn peek_from(&self, _: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn send_to(&self, _: &[u8], _: &SocketAddr) -> io::Result<usize> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn duplicate(&self) -> io::Result<UdpSocket> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn set_read_timeout(&self, _: Option<Duration>) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn set_write_timeout(&self, _: Option<Duration>) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn read_timeout(&self) -> io::Result<Option<Duration>> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn write_timeout(&self) -> io::Result<Option<Duration>> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn set_broadcast(&self, _: bool) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn broadcast(&self) -> io::Result<bool> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn set_multicast_loop_v4(&self, _: bool) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn multicast_loop_v4(&self) -> io::Result<bool> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn set_multicast_ttl_v4(&self, _: u32) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn multicast_ttl_v4(&self) -> io::Result<u32> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn set_multicast_loop_v6(&self, _: bool) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn multicast_loop_v6(&self) -> io::Result<bool> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn join_multicast_v4(&self, _: &Ipv4Addr, _: &Ipv4Addr) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn join_multicast_v6(&self, _: &Ipv6Addr, _: u32) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn leave_multicast_v4(&self, _: &Ipv4Addr, _: &Ipv4Addr) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn leave_multicast_v6(&self, _: &Ipv6Addr, _: u32) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn set_ttl(&self, _: u32) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn ttl(&self) -> io::Result<u32> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn take_error(&self) -> io::Result<Option<io::Error>> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn set_nonblocking(&self, _: bool) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn recv(&self, _: &mut [u8]) -> io::Result<usize> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn peek(&self, _: &mut [u8]) -> io::Result<usize> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn send(&self, _: &[u8]) -> io::Result<usize> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 
     pub fn connect(&self, _: io::Result<&SocketAddr>) -> io::Result<()> {
-        Err(io::Error::new_const(ErrorKind::Other, &"not supported"))
+        unsupported()
     }
 }
 

library/std/src/sys/sgx/mod.rs

@@ -50,7 +50,7 @@ pub fn unsupported<T>() -> crate::io::Result<T> {
 }
 
 pub fn unsupported_err() -> crate::io::Error {
-    crate::io::Error::new_const(ErrorKind::Other, &"operation not supported on SGX yet")
+    crate::io::Error::new_const(ErrorKind::Unsupported, &"operation not supported on SGX yet")
 }
 
 /// This function is used to implement various functions that doesn't exist,

library/std/src/sys/unix/fs.rs

@@ -366,7 +366,7 @@ impl FileAttr {
         }
 
         Err(io::Error::new_const(
-            io::ErrorKind::Other,
+            io::ErrorKind::Unsupported,
             &"creation time is not available on this platform \
                             currently",
         ))

library/std/src/sys/unix/l4re.rs

@@ -1,6 +1,9 @@
 macro_rules! unimpl {
     () => {
-        return Err(io::Error::new_const(io::ErrorKind::Other, &"No networking available on L4Re."));
+        return Err(io::Error::new_const(
+            io::ErrorKind::Unsupported,
+            &"No networking available on L4Re.",
+        ));
     };
 }
 

library/std/src/sys/unix/mod.rs

@@ -148,6 +148,7 @@ pub fn decode_error_kind(errno: i32) -> ErrorKind {
         libc::EINVAL => ErrorKind::InvalidInput,
         libc::ETIMEDOUT => ErrorKind::TimedOut,
         libc::EEXIST => ErrorKind::AlreadyExists,
+        libc::ENOSYS => ErrorKind::Unsupported,
 
         // These two constants can have the same value on some systems,
         // but different values on others, so we can't use a match

library/std/src/sys/unix/os.rs

@@ -447,7 +447,7 @@ pub fn current_exe() -> io::Result<PathBuf> {
 #[cfg(any(target_os = "fuchsia", target_os = "l4re"))]
 pub fn current_exe() -> io::Result<PathBuf> {
     use crate::io::ErrorKind;
-    Err(io::Error::new_const(ErrorKind::Other, &"Not yet implemented!"))
+    Err(io::Error::new_const(ErrorKind::Unsupported, &"Not yet implemented!"))
 }
 
 #[cfg(target_os = "vxworks")]

library/std/src/sys/unsupported/common.rs

@@ -18,7 +18,10 @@ pub fn unsupported<T>() -> std_io::Result<T> {
 }
 
 pub fn unsupported_err() -> std_io::Error {
-    std_io::Error::new_const(std_io::ErrorKind::Other, &"operation not supported on this platform")
+    std_io::Error::new_const(
+        std_io::ErrorKind::Unsupported,
+        &"operation not supported on this platform",
+    )
 }
 
 pub fn decode_error_kind(_code: i32) -> crate::io::ErrorKind {

library/std/src/sys/unsupported/os.rs

@@ -80,11 +80,11 @@ pub fn getenv(_: &OsStr) -> io::Result<Option<OsString>> {
 }
 
 pub fn setenv(_: &OsStr, _: &OsStr) -> io::Result<()> {
-    Err(io::Error::new_const(io::ErrorKind::Other, &"cannot set env vars on this platform"))
+    Err(io::Error::new_const(io::ErrorKind::Unsupported, &"cannot set env vars on this platform"))
 }
 
 pub fn unsetenv(_: &OsStr) -> io::Result<()> {
-    Err(io::Error::new_const(io::ErrorKind::Other, &"cannot unset env vars on this platform"))
+    Err(io::Error::new_const(io::ErrorKind::Unsupported, &"cannot unset env vars on this platform"))
 }
 
 pub fn temp_dir() -> PathBuf {

library/std/src/sys/vxworks/mod.rs

@@ -83,6 +83,7 @@ pub fn decode_error_kind(errno: i32) -> ErrorKind {
         libc::EINVAL => ErrorKind::InvalidInput,
         libc::ETIMEDOUT => ErrorKind::TimedOut,
         libc::EEXIST => ErrorKind::AlreadyExists,
+        libc::ENOSYS => ErrorKind::Unsupported,
 
         // These two constants can have the same value on some systems,
         // but different values on others, so we can't use a match

library/std/src/sys/wasi/mod.rs

@@ -78,6 +78,7 @@ pub fn decode_error_kind(errno: i32) -> std_io::ErrorKind {
         wasi::ERRNO_TIMEDOUT => TimedOut,
         wasi::ERRNO_EXIST => AlreadyExists,
         wasi::ERRNO_AGAIN => WouldBlock,
+        wasi::ERRNO_NOSYS => Unsupported,
         _ => Other,
     }
 }

library/std/src/sys/windows/fs.rs

@@ -802,7 +802,10 @@ pub fn link(original: &Path, link: &Path) -> io::Result<()> {
 
 #[cfg(target_vendor = "uwp")]
 pub fn link(_original: &Path, _link: &Path) -> io::Result<()> {
-    return Err(io::Error::new_const(io::ErrorKind::Other, &"hard link are not supported on UWP"));
+    return Err(io::Error::new_const(
+        io::ErrorKind::Unsupported,
+        &"hard link are not supported on UWP",
+    ));
 }
 
 pub fn stat(path: &Path) -> io::Result<FileAttr> {

library/std/src/sys/windows/mod.rs

@@ -78,6 +78,7 @@ pub fn decode_error_kind(errno: i32) -> ErrorKind {
         | c::ERROR_IPSEC_IKE_TIMED_OUT
         | c::ERROR_RUNLEVEL_SWITCH_TIMEOUT
         | c::ERROR_RUNLEVEL_SWITCH_AGENT_TIMEOUT => return ErrorKind::TimedOut,
+        c::ERROR_CALL_NOT_IMPLEMENTED => return ErrorKind::Unsupported,
         _ => {}
     }