Use #[non_exhaustive] on internal enums

src/libcore/lib.rs

@@ -120,6 +120,7 @@
 #![feature(const_slice_len)]
 #![feature(const_str_as_bytes)]
 #![feature(const_str_len)]
+#![feature(non_exhaustive)]
 
 #[prelude_import]
 #[allow(unused)]

src/libcore/sync/atomic.rs

@@ -185,6 +185,7 @@ unsafe impl<T> Sync for AtomicPtr<T> {}
 /// [nomicon]: ../../../nomicon/atomics.html
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(Copy, Clone, Debug)]
+#[non_exhaustive]
 pub enum Ordering {
     /// No ordering constraints, only atomic operations.
     ///
@@ -256,10 +257,6 @@ pub enum Ordering {
     /// [`AcqRel`]: https://llvm.org/docs/Atomics.html#acquirerelease
     #[stable(feature = "rust1", since = "1.0.0")]
     SeqCst,
-    // Prevent exhaustive matching to allow for future extension
-    #[doc(hidden)]
-    #[unstable(feature = "future_atomic_orderings", issue = "0")]
-    __Nonexhaustive,
 }
 
 /// An [`AtomicBool`] initialized to `false`.
@@ -1954,7 +1951,6 @@ fn strongest_failure_ordering(order: Ordering) -> Ordering {
         SeqCst => SeqCst,
         Acquire => Acquire,
         AcqRel => Acquire,
-        __Nonexhaustive => __Nonexhaustive,
     }
 }
 
@@ -1966,7 +1962,6 @@ unsafe fn atomic_store<T>(dst: *mut T, val: T, order: Ordering) {
         SeqCst => intrinsics::atomic_store(dst, val),
         Acquire => panic!("there is no such thing as an acquire store"),
         AcqRel => panic!("there is no such thing as an acquire/release store"),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -1978,7 +1973,6 @@ unsafe fn atomic_load<T>(dst: *const T, order: Ordering) -> T {
         SeqCst => intrinsics::atomic_load(dst),
         Release => panic!("there is no such thing as a release load"),
         AcqRel => panic!("there is no such thing as an acquire/release load"),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -1991,7 +1985,6 @@ unsafe fn atomic_swap<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_xchg_acqrel(dst, val),
         Relaxed => intrinsics::atomic_xchg_relaxed(dst, val),
         SeqCst => intrinsics::atomic_xchg(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2004,7 +1997,6 @@ unsafe fn atomic_add<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_xadd_acqrel(dst, val),
         Relaxed => intrinsics::atomic_xadd_relaxed(dst, val),
         SeqCst => intrinsics::atomic_xadd(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2017,7 +2009,6 @@ unsafe fn atomic_sub<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_xsub_acqrel(dst, val),
         Relaxed => intrinsics::atomic_xsub_relaxed(dst, val),
         SeqCst => intrinsics::atomic_xsub(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2039,8 +2030,6 @@ unsafe fn atomic_compare_exchange<T>(dst: *mut T,
         (AcqRel, Relaxed) => intrinsics::atomic_cxchg_acqrel_failrelaxed(dst, old, new),
         (SeqCst, Relaxed) => intrinsics::atomic_cxchg_failrelaxed(dst, old, new),
         (SeqCst, Acquire) => intrinsics::atomic_cxchg_failacq(dst, old, new),
-        (__Nonexhaustive, _) => panic!("invalid memory ordering"),
-        (_, __Nonexhaustive) => panic!("invalid memory ordering"),
         (_, AcqRel) => panic!("there is no such thing as an acquire/release failure ordering"),
         (_, Release) => panic!("there is no such thing as a release failure ordering"),
         _ => panic!("a failure ordering can't be stronger than a success ordering"),
@@ -2065,8 +2054,6 @@ unsafe fn atomic_compare_exchange_weak<T>(dst: *mut T,
         (AcqRel, Relaxed) => intrinsics::atomic_cxchgweak_acqrel_failrelaxed(dst, old, new),
         (SeqCst, Relaxed) => intrinsics::atomic_cxchgweak_failrelaxed(dst, old, new),
         (SeqCst, Acquire) => intrinsics::atomic_cxchgweak_failacq(dst, old, new),
-        (__Nonexhaustive, _) => panic!("invalid memory ordering"),
-        (_, __Nonexhaustive) => panic!("invalid memory ordering"),
         (_, AcqRel) => panic!("there is no such thing as an acquire/release failure ordering"),
         (_, Release) => panic!("there is no such thing as a release failure ordering"),
         _ => panic!("a failure ordering can't be stronger than a success ordering"),
@@ -2082,7 +2069,6 @@ unsafe fn atomic_and<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_and_acqrel(dst, val),
         Relaxed => intrinsics::atomic_and_relaxed(dst, val),
         SeqCst => intrinsics::atomic_and(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2094,7 +2080,6 @@ unsafe fn atomic_nand<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_nand_acqrel(dst, val),
         Relaxed => intrinsics::atomic_nand_relaxed(dst, val),
         SeqCst => intrinsics::atomic_nand(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2106,7 +2091,6 @@ unsafe fn atomic_or<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_or_acqrel(dst, val),
         Relaxed => intrinsics::atomic_or_relaxed(dst, val),
         SeqCst => intrinsics::atomic_or(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2118,7 +2102,6 @@ unsafe fn atomic_xor<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_xor_acqrel(dst, val),
         Relaxed => intrinsics::atomic_xor_relaxed(dst, val),
         SeqCst => intrinsics::atomic_xor(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2131,7 +2114,6 @@ unsafe fn atomic_max<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_max_acqrel(dst, val),
         Relaxed => intrinsics::atomic_max_relaxed(dst, val),
         SeqCst => intrinsics::atomic_max(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2144,7 +2126,6 @@ unsafe fn atomic_min<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_min_acqrel(dst, val),
         Relaxed => intrinsics::atomic_min_relaxed(dst, val),
         SeqCst => intrinsics::atomic_min(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2157,7 +2138,6 @@ unsafe fn atomic_umax<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_umax_acqrel(dst, val),
         Relaxed => intrinsics::atomic_umax_relaxed(dst, val),
         SeqCst => intrinsics::atomic_umax(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2170,7 +2150,6 @@ unsafe fn atomic_umin<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_umin_acqrel(dst, val),
         Relaxed => intrinsics::atomic_umin_relaxed(dst, val),
         SeqCst => intrinsics::atomic_umin(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2260,7 +2239,6 @@ pub fn fence(order: Ordering) {
             AcqRel => intrinsics::atomic_fence_acqrel(),
             SeqCst => intrinsics::atomic_fence(),
             Relaxed => panic!("there is no such thing as a relaxed fence"),
-            __Nonexhaustive => panic!("invalid memory ordering"),
         }
     }
 }
@@ -2350,7 +2328,6 @@ pub fn compiler_fence(order: Ordering) {
             AcqRel => intrinsics::atomic_singlethreadfence_acqrel(),
             SeqCst => intrinsics::atomic_singlethreadfence(),
             Relaxed => panic!("there is no such thing as a relaxed compiler fence"),
-            __Nonexhaustive => panic!("invalid memory ordering"),
         }
     }
 }

src/libproc_macro/diagnostic.rs

@@ -16,6 +16,7 @@ use syntax_pos::MultiSpan;
 /// An enum representing a diagnostic level.
 #[unstable(feature = "proc_macro_diagnostic", issue = "38356")]
 #[derive(Copy, Clone, Debug)]
+#[non_exhaustive]
 pub enum Level {
     /// An error.
     Error,
@@ -25,8 +26,6 @@ pub enum Level {
     Note,
     /// A help message.
     Help,
-    #[doc(hidden)]
-    __Nonexhaustive,
 }
 
 /// A structure representing a diagnostic message and associated children

src/libproc_macro/lib.rs

@@ -36,6 +36,7 @@
 #![feature(staged_api)]
 #![feature(lang_items)]
 #![feature(optin_builtin_traits)]
+#![feature(non_exhaustive)]
 
 #![recursion_limit="256"]
 

src/libproc_macro/rustc.rs

@@ -278,7 +278,6 @@ impl Level {
             Level::Warning => errors::Level::Warning,
             Level::Note => errors::Level::Note,
             Level::Help => errors::Level::Help,
-            Level::__Nonexhaustive => unreachable!("Level::__Nonexhaustive"),
         }
     }
 }

src/libstd/io/error.rs

@@ -97,6 +97,7 @@ struct Custom {
 #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[allow(deprecated)]
+#[non_exhaustive]
 pub enum ErrorKind {
     /// An entity was not found, often a file.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -180,15 +181,6 @@ pub enum ErrorKind {
     /// read.
     #[stable(feature = "read_exact", since = "1.6.0")]
     UnexpectedEof,
-
-    /// A marker variant that tells the compiler that users of this enum cannot
-    /// match it exhaustively.
-    #[unstable(feature = "io_error_internals",
-               reason = "better expressed through extensible enums that this \
-                         enum cannot be exhaustively matched against",
-               issue = "0")]
-    #[doc(hidden)]
-    __Nonexhaustive,
 }
 
 impl ErrorKind {
@@ -212,7 +204,6 @@ impl ErrorKind {
             ErrorKind::Interrupted => "operation interrupted",
             ErrorKind::Other => "other os error",
             ErrorKind::UnexpectedEof => "unexpected end of file",
-            ErrorKind::__Nonexhaustive => unreachable!()
         }
     }
 }

src/libstd/lib.rs

@@ -311,6 +311,7 @@
 #![feature(doc_keyword)]
 #![feature(panic_info_message)]
 #![feature(panic_implementation)]
+#![feature(non_exhaustive)]
 
 #![default_lib_allocator]
 

src/libstd/sys/cloudabi/abi/cloudabi.rs

@@ -121,6 +121,7 @@ include!("bitflags.rs");
 /// File or memory access pattern advisory information.
 #[repr(u8)]
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
+#[non_exhaustive]
 pub enum advice {
   /// The application expects that it will not access the
   /// specified data in the near future.
@@ -140,12 +141,12 @@ pub enum advice {
   /// The application expects to access the specified data
   /// in the near future.
   WILLNEED   = 6,
-  #[doc(hidden)] _NonExhaustive = -1 as isize as u8,
 }
 
 /// Enumeration describing the kind of value stored in [`auxv`](struct.auxv.html).
 #[repr(u32)]
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
+#[non_exhaustive]
 pub enum auxtype {
   /// Base address of the binary argument data provided to
   /// [`proc_exec()`](fn.proc_exec.html).
@@ -210,12 +211,12 @@ pub enum auxtype {
   SYSINFO_EHDR = 262,
   /// Thread ID of the initial thread of the process.
   TID          = 261,
-  #[doc(hidden)] _NonExhaustive = -1 as isize as u32,
 }
 
 /// Identifiers for clocks.
 #[repr(u32)]
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
+#[non_exhaustive]
 pub enum clockid {
   /// The system-wide monotonic clock, which is defined as a
   /// clock measuring real time, whose value cannot be
@@ -232,7 +233,6 @@ pub enum clockid {
   REALTIME           = 3,
   /// The CPU-time clock associated with the current thread.
   THREAD_CPUTIME_ID  = 4,
-  #[doc(hidden)] _NonExhaustive = -1 as isize as u32,
 }
 
 /// A userspace condition variable.
@@ -267,6 +267,7 @@ pub const DIRCOOKIE_START: dircookie = dircookie(0);
 /// exclusively or merely provided for alignment with POSIX.
 #[repr(u16)]
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
+#[non_exhaustive]
 pub enum errno {
   /// No error occurred. System call completed successfully.
   SUCCESS        =  0,
@@ -422,7 +423,6 @@ pub enum errno {
   XDEV           = 75,
   /// Extension: Capabilities insufficient.
   NOTCAPABLE     = 76,
-  #[doc(hidden)] _NonExhaustive = -1 as isize as u16,
 }
 
 bitflags! {
@@ -438,6 +438,7 @@ bitflags! {
 /// Type of a subscription to an event or its occurrence.
 #[repr(u8)]
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
+#[non_exhaustive]
 pub enum eventtype {
   /// The time value of clock [`subscription.union.clock.clock_id`](struct.subscription_clock.html#structfield.clock_id)
   /// has reached timestamp [`subscription.union.clock.timeout`](struct.subscription_clock.html#structfield.timeout).
@@ -463,7 +464,6 @@ pub enum eventtype {
   /// The process associated with process descriptor
   /// [`subscription.union.proc_terminate.fd`](struct.subscription_proc_terminate.html#structfield.fd) has terminated.
   PROC_TERMINATE = 7,
-  #[doc(hidden)] _NonExhaustive = -1 as isize as u8,
 }
 
 /// Exit code generated by a process when exiting.
@@ -530,6 +530,7 @@ pub type filesize = u64;
 /// The type of a file descriptor or file.
 #[repr(u8)]
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
+#[non_exhaustive]
 pub enum filetype {
   /// The type of the file descriptor or file is unknown or
   /// is different from any of the other types specified.
@@ -558,7 +559,6 @@ pub enum filetype {
   SOCKET_STREAM    = 130,
   /// The file refers to a symbolic link inode.
   SYMBOLIC_LINK    = 144,
-  #[doc(hidden)] _NonExhaustive = -1 as isize as u8,
 }
 
 bitflags! {
@@ -847,12 +847,12 @@ bitflags! {
 /// memory.
 #[repr(u8)]
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
+#[non_exhaustive]
 pub enum scope {
   /// The object is stored in private memory.
   PRIVATE = 4,
   /// The object is stored in shared memory.
   SHARED  = 8,
-  #[doc(hidden)] _NonExhaustive = -1 as isize as u8,
 }
 
 bitflags! {
@@ -878,6 +878,7 @@ bitflags! {
 /// Signal condition.
 #[repr(u8)]
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
+#[non_exhaustive]
 pub enum signal {
   /// Process abort signal.
   ///
@@ -983,7 +984,6 @@ pub enum signal {
   ///
   /// Action: Terminates the process.
   XFSZ   = 26,
-  #[doc(hidden)] _NonExhaustive = -1 as isize as u8,
 }
 
 bitflags! {
@@ -1049,14 +1049,14 @@ pub type userdata = u64;
 /// should be set.
 #[repr(u8)]
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
+#[non_exhaustive]
 pub enum whence {
   /// Seek relative to current position.
   CUR = 1,
   /// Seek relative to end-of-file.
   END = 2,
   /// Seek relative to start-of-file.
   SET = 3,
-  #[doc(hidden)] _NonExhaustive = -1 as isize as u8,
 }
 
 /// Auxiliary vector entry.