stabilise feature(never_type)

Replace feature(never_type) with feature(exhaustive_patterns).
feature(exhaustive_patterns) only covers the pattern-exhaustives checks
that used to be covered by feature(never_type)

Author: canndrew

src/libcore/cmp.rs

@@ -882,24 +882,24 @@ mod impls {
 
     ord_impl! { char usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 
-    #[unstable(feature = "never_type", issue = "35121")]
+    #[stable(feature = "never_type", since = "1.24.0")]
     impl PartialEq for ! {
         fn eq(&self, _: &!) -> bool {
             *self
         }
     }
 
-    #[unstable(feature = "never_type", issue = "35121")]
+    #[stable(feature = "never_type", since = "1.24.0")]
     impl Eq for ! {}
 
-    #[unstable(feature = "never_type", issue = "35121")]
+    #[stable(feature = "never_type", since = "1.24.0")]
     impl PartialOrd for ! {
         fn partial_cmp(&self, _: &!) -> Option<Ordering> {
             *self
         }
     }
 
-    #[unstable(feature = "never_type", issue = "35121")]
+    #[stable(feature = "never_type", since = "1.24.0")]
     impl Ord for ! {
         fn cmp(&self, _: &!) -> Ordering {
             *self

src/libcore/fmt/mod.rs

@@ -1579,14 +1579,14 @@ macro_rules! fmt_refs {
 
 fmt_refs! { Debug, Display, Octal, Binary, LowerHex, UpperHex, LowerExp, UpperExp }
 
-#[unstable(feature = "never_type", issue = "35121")]
+#[stable(feature = "never_type", since = "1.24.0")]
 impl Debug for ! {
     fn fmt(&self, _: &mut Formatter) -> Result {
         *self
     }
 }
 
-#[unstable(feature = "never_type", issue = "35121")]
+#[stable(feature = "never_type", since = "1.24.0")]
 impl Display for ! {
     fn fmt(&self, _: &mut Formatter) -> Result {
         *self

src/libcore/lib.rs

@@ -85,7 +85,7 @@
 #![feature(iterator_repeat_with)]
 #![feature(lang_items)]
 #![feature(link_llvm_intrinsics)]
-#![feature(never_type)]
+#![feature(exhaustive_patterns)]
 #![feature(no_core)]
 #![feature(on_unimplemented)]
 #![feature(optin_builtin_traits)]
@@ -103,6 +103,7 @@
 #![feature(unwind_attributes)]
 
 #![cfg_attr(stage0, allow(unused_attributes))]
+#![cfg_attr(stage0, feature(never_type))]
 
 #[prelude_import]
 #[allow(unused)]

src/librustc/lib.rs

@@ -60,7 +60,7 @@
 #![feature(match_default_bindings)]
 #![feature(macro_lifetime_matcher)]
 #![feature(macro_vis_matcher)]
-#![feature(never_type)]
+#![feature(exhaustive_patterns)]
 #![feature(non_exhaustive)]
 #![feature(nonzero)]
 #![feature(proc_macro_internals)]

src/librustc_lint/lib.rs

@@ -32,6 +32,7 @@
 #![feature(quote)]
 #![feature(rustc_diagnostic_macros)]
 #![feature(slice_patterns)]
+#![cfg_attr(stage0, feature(never_type))]
 
 #[macro_use]
 extern crate syntax;

src/librustc_mir/build/matches/simplify.rs

@@ -113,7 +113,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
             PatternKind::Variant { adt_def, substs, variant_index, ref subpatterns } => {
                 let irrefutable = adt_def.variants.iter().enumerate().all(|(i, v)| {
                     i == variant_index || {
-                        self.hir.tcx().features().never_type &&
+                        self.hir.tcx().features().exhaustive_patterns &&
                         self.hir.tcx().is_variant_uninhabited_from_all_modules(v, substs)
                     }
                 });

src/librustc_mir/hair/pattern/_match.rs

@@ -219,7 +219,7 @@ impl<'a, 'tcx> MatchCheckCtxt<'a, 'tcx> {
     }
 
     fn is_uninhabited(&self, ty: Ty<'tcx>) -> bool {
-        if self.tcx.features().never_type {
+        if self.tcx.features().exhaustive_patterns {
             self.tcx.is_ty_uninhabited_from(self.module, ty)
         } else {
             false
@@ -245,7 +245,7 @@ impl<'a, 'tcx> MatchCheckCtxt<'a, 'tcx> {
                               substs: &'tcx ty::subst::Substs<'tcx>)
                               -> bool
     {
-        if self.tcx.features().never_type {
+        if self.tcx.features().exhaustive_patterns {
             self.tcx.is_enum_variant_uninhabited_from(self.module, variant, substs)
         } else {
             false
@@ -694,7 +694,7 @@ pub fn is_useful<'p, 'a: 'p, 'tcx: 'a>(cx: &mut MatchCheckCtxt<'a, 'tcx>,
         // test for details.
         //
         // FIXME: currently the only way I know of something can
-        // be a privately-empty enum is when the never_type
+        // be a privately-empty enum is when the exhaustive_patterns
         // feature flag is not present, so this is only
         // needed for that case.
 

src/librustc_mir/hair/pattern/check_match.rs

@@ -222,7 +222,7 @@ impl<'a, 'tcx> MatchVisitor<'a, 'tcx> {
             let pat_ty = self.tables.node_id_to_type(scrut.hir_id);
             let module = self.tcx.hir.get_module_parent(scrut.id);
             if inlined_arms.is_empty() {
-                let scrutinee_is_uninhabited = if self.tcx.features().never_type {
+                let scrutinee_is_uninhabited = if self.tcx.features().exhaustive_patterns {
                     self.tcx.is_ty_uninhabited_from(module, pat_ty)
                 } else {
                     self.conservative_is_uninhabited(pat_ty)

src/librustc_mir/lib.rs

@@ -32,13 +32,14 @@ Rust MIR: a lowered representation of Rust. Also: an experiment!
 #![feature(inclusive_range)]
 #![feature(macro_vis_matcher)]
 #![feature(match_default_bindings)]
-#![feature(never_type)]
+#![feature(exhaustive_patterns)]
 #![feature(range_contains)]
 #![feature(rustc_diagnostic_macros)]
 #![feature(placement_in_syntax)]
 #![feature(collection_placement)]
 #![feature(nonzero)]
 #![feature(underscore_lifetimes)]
+#![cfg_attr(stage0, feature(never_type))]
 
 extern crate arena;
 #[macro_use]

src/librustc_typeck/lib.rs

@@ -80,13 +80,14 @@ This API is completely unstable and subject to change.
 #![feature(crate_visibility_modifier)]
 #![feature(from_ref)]
 #![feature(match_default_bindings)]
-#![feature(never_type)]
+#![feature(exhaustive_patterns)]
 #![feature(option_filter)]
 #![feature(quote)]
 #![feature(refcell_replace_swap)]
 #![feature(rustc_diagnostic_macros)]
 #![feature(slice_patterns)]
 #![feature(i128_type)]
+#![cfg_attr(stage0, feature(never_type))]
 
 #[macro_use] extern crate log;
 #[macro_use] extern crate syntax;