diff --git a/library/std/src/os/windows/io/handle.rs b/library/std/src/os/windows/io/handle.rs index ee30cc8be6b57..e4de52612ef62 100644 --- a/library/std/src/os/windows/io/handle.rs +++ b/library/std/src/os/windows/io/handle.rs @@ -76,7 +76,7 @@ pub struct OwnedHandle { /// `NULL`. This ensures that such FFI calls cannot start using the handle without /// checking for `NULL` first. /// -/// This type concerns any value other than `NULL` to be valid, including `INVALID_HANDLE_VALUE`. +/// This type considers any value other than `NULL` to be valid, including `INVALID_HANDLE_VALUE`. /// This is because APIs that use `NULL` as their sentry value don't treat `INVALID_HANDLE_VALUE` /// as special. /// @@ -96,7 +96,7 @@ pub struct HandleOrNull(OwnedHandle); /// `INVALID_HANDLE_VALUE`. This ensures that such FFI calls cannot start using the handle without /// checking for `INVALID_HANDLE_VALUE` first. /// -/// This type concerns any value other than `INVALID_HANDLE_VALUE` to be valid, including `NULL`. +/// This type considers any value other than `INVALID_HANDLE_VALUE` to be valid, including `NULL`. /// This is because APIs that use `INVALID_HANDLE_VALUE` as their sentry value may return `NULL` /// under `windows_subsystem = "windows"` or other situations where I/O devices are detached. /// @@ -143,17 +143,17 @@ impl BorrowedHandle<'_> { } impl TryFrom for OwnedHandle { - type Error = (); + type Error = NullHandleError; #[inline] - fn try_from(handle_or_null: HandleOrNull) -> Result { + fn try_from(handle_or_null: HandleOrNull) -> Result { let owned_handle = handle_or_null.0; if owned_handle.handle.is_null() { // Don't call `CloseHandle`; it'd be harmless, except that it could // overwrite the `GetLastError` error. forget(owned_handle); - Err(()) + Err(NullHandleError(())) } else { Ok(owned_handle) } @@ -201,23 +201,59 @@ impl OwnedHandle { } impl TryFrom for OwnedHandle { - type Error = (); + type Error = InvalidHandleError; #[inline] - fn try_from(handle_or_invalid: HandleOrInvalid) -> Result { + fn try_from(handle_or_invalid: HandleOrInvalid) -> Result { let owned_handle = handle_or_invalid.0; if owned_handle.handle == c::INVALID_HANDLE_VALUE { // Don't call `CloseHandle`; it'd be harmless, except that it could // overwrite the `GetLastError` error. forget(owned_handle); - Err(()) + Err(InvalidHandleError(())) } else { Ok(owned_handle) } } } +/// This is the error type used by [`HandleOrNull`] when attempting to convert +/// into a handle, to indicate that the value is null. +// The empty field prevents constructing this, and allows extending it in the future. +#[unstable(feature = "io_safety", issue = "87074")] +#[derive(Debug, Clone, PartialEq, Eq)] +pub struct NullHandleError(()); + +#[unstable(feature = "io_safety", issue = "87074")] +impl fmt::Display for NullHandleError { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + "A HandleOrNull could not be converted to a handle because it was null".fmt(fmt) + } +} + +#[unstable(feature = "io_safety", issue = "87074")] +impl crate::error::Error for NullHandleError {} + +/// This is the error type used by [`HandleOrInvalid`] when attempting to +/// convert into a handle, to indicate that the value is +/// `INVALID_HANDLE_VALUE`. +// The empty field prevents constructing this, and allows extending it in the future. +#[unstable(feature = "io_safety", issue = "87074")] +#[derive(Debug, Clone, PartialEq, Eq)] +pub struct InvalidHandleError(()); + +#[unstable(feature = "io_safety", issue = "87074")] +impl fmt::Display for InvalidHandleError { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + "A HandleOrInvalid could not be converted to a handle because it was INVALID_HANDLE_VALUE" + .fmt(fmt) + } +} + +#[unstable(feature = "io_safety", issue = "87074")] +impl crate::error::Error for InvalidHandleError {} + impl AsRawHandle for BorrowedHandle<'_> { #[inline] fn as_raw_handle(&self) -> RawHandle {