Remove impl Foo for .. in favor of auto trait Foo

No longer parse it.
Remove AutoTrait variant from AST and HIR.
Remove backwards compatibility lint.
Remove coherence checks, they make no sense for the new syntax.
Remove from rustdoc.

Author: leoyvens

src/libcore/marker.rs

@@ -40,15 +40,10 @@ use hash::Hasher;
 /// [ub]: ../../reference/behavior-considered-undefined.html
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_on_unimplemented = "`{Self}` cannot be sent between threads safely"]
-pub unsafe trait Send {
+pub unsafe auto trait Send {
     // empty.
 }
 
-#[stable(feature = "rust1", since = "1.0.0")]
-#[allow(unknown_lints)]
-#[allow(auto_impl)]
-unsafe impl Send for .. { }
-
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> !Send for *const T { }
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -345,15 +340,10 @@ pub trait Copy : Clone {
 #[stable(feature = "rust1", since = "1.0.0")]
 #[lang = "sync"]
 #[rustc_on_unimplemented = "`{Self}` cannot be shared between threads safely"]
-pub unsafe trait Sync {
+pub unsafe auto trait Sync {
     // Empty
 }
 
-#[stable(feature = "rust1", since = "1.0.0")]
-#[allow(unknown_lints)]
-#[allow(auto_impl)]
-unsafe impl Sync for .. { }
-
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> !Sync for *const T { }
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -563,11 +553,7 @@ mod impls {
 /// This affects, for example, whether a `static` of that type is
 /// placed in read-only static memory or writable static memory.
 #[lang = "freeze"]
-unsafe trait Freeze {}
-
-#[allow(unknown_lints)]
-#[allow(auto_impl)]
-unsafe impl Freeze for .. {}
+unsafe auto trait Freeze {}
 
 impl<T: ?Sized> !Freeze for UnsafeCell<T> {}
 unsafe impl<T: ?Sized> Freeze for PhantomData<T> {}

src/librustc/dep_graph/dep_node.rs

@@ -496,7 +496,6 @@ define_dep_nodes!( <'tcx>
     [] SuperPredicatesOfItem(DefId),
     [] TraitDefOfItem(DefId),
     [] AdtDefOfItem(DefId),
-    [] IsAutoImpl(DefId),
     [] ImplTraitRef(DefId),
     [] ImplPolarity(DefId),
     [] FnSignature(DefId),

src/librustc/hir/intravisit.rs

@@ -498,10 +498,6 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
             // visit_enum_def() takes care of visiting the Item's NodeId
             visitor.visit_enum_def(enum_definition, type_parameters, item.id, item.span)
         }
-        ItemAutoImpl(_, ref trait_ref) => {
-            visitor.visit_id(item.id);
-            visitor.visit_trait_ref(trait_ref)
-        }
         ItemImpl(.., ref type_parameters, ref opt_trait_reference, ref typ, ref impl_item_refs) => {
             visitor.visit_id(item.id);
             visitor.visit_generics(type_parameters);

src/librustc/hir/lowering.rs

@@ -1952,16 +1952,6 @@ impl<'a> LoweringContext<'a> {
                 let vdata = self.lower_variant_data(vdata);
                 hir::ItemUnion(vdata, self.lower_generics(generics))
             }
-            ItemKind::AutoImpl(unsafety, ref trait_ref) => {
-                let trait_ref = self.lower_trait_ref(trait_ref, ImplTraitContext::Disallowed);
-
-                if let Def::Trait(def_id) = trait_ref.path.def {
-                    self.trait_auto_impl.insert(def_id, id);
-                }
-
-                hir::ItemAutoImpl(self.lower_unsafety(unsafety),
-                                     trait_ref)
-            }
             ItemKind::Impl(unsafety,
                            polarity,
                            defaultness,

src/librustc/hir/map/def_collector.rs

@@ -104,8 +104,7 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
         // Pick the def data. This need not be unique, but the more
         // information we encapsulate into
         let def_data = match i.node {
-            ItemKind::AutoImpl(..) | ItemKind::Impl(..) =>
-                DefPathData::Impl,
+            ItemKind::Impl(..) => DefPathData::Impl,
             ItemKind::Enum(..) | ItemKind::Struct(..) | ItemKind::Union(..) |
             ItemKind::Trait(..) | ItemKind::TraitAlias(..) |
             ItemKind::ExternCrate(..) | ItemKind::ForeignMod(..) | ItemKind::Ty(..) =>

src/librustc/hir/map/mod.rs

@@ -1192,7 +1192,6 @@ fn node_id_to_string(map: &Map, id: NodeId, include_id: bool) -> String {
                 ItemTrait(..) => "trait",
                 ItemTraitAlias(..) => "trait alias",
                 ItemImpl(..) => "impl",
-                ItemAutoImpl(..) => "default impl",
             };
             format!("{} {}{}", item_str, path_str(), id_str)
         }

src/librustc/hir/mod.rs

@@ -1965,10 +1965,6 @@ pub enum Item_ {
     /// Represents a Trait Alias Declaration
     ItemTraitAlias(Generics, TyParamBounds),
 
-    /// Auto trait implementations
-    ///
-    /// `impl Trait for .. {}`
-    ItemAutoImpl(Unsafety, TraitRef),
     /// An implementation, eg `impl<A> Trait for Foo { .. }`
     ItemImpl(Unsafety,
              ImplPolarity,
@@ -1996,8 +1992,7 @@ impl Item_ {
             ItemUnion(..) => "union",
             ItemTrait(..) => "trait",
             ItemTraitAlias(..) => "trait alias",
-            ItemImpl(..) |
-            ItemAutoImpl(..) => "item",
+            ItemImpl(..) => "item",
         }
     }
 

src/librustc/hir/print.rs

@@ -652,18 +652,6 @@ impl<'a> State<'a> {
                 self.head(&visibility_qualified(&item.vis, "union"))?;
                 self.print_struct(struct_def, generics, item.name, item.span, true)?;
             }
-            hir::ItemAutoImpl(unsafety, ref trait_ref) => {
-                self.head("")?;
-                self.print_visibility(&item.vis)?;
-                self.print_unsafety(unsafety)?;
-                self.word_nbsp("impl")?;
-                self.print_trait_ref(trait_ref)?;
-                self.s.space()?;
-                self.word_space("for")?;
-                self.word_space("..")?;
-                self.bopen()?;
-                self.bclose(item.span)?;
-            }
             hir::ItemImpl(unsafety,
                           polarity,
                           defaultness,

src/librustc/ich/impls_hir.rs

@@ -854,7 +854,6 @@ impl_stable_hash_for!(enum hir::Item_ {
     ItemUnion(variant_data, generics),
     ItemTrait(is_auto, unsafety, generics, bounds, item_refs),
     ItemTraitAlias(generics, bounds),
-    ItemAutoImpl(unsafety, trait_ref),
     ItemImpl(unsafety, impl_polarity, impl_defaultness, generics, trait_ref, ty, impl_item_refs)
 });
 

src/librustc/middle/dead.rs

@@ -564,7 +564,6 @@ impl<'a, 'tcx> Visitor<'tcx> for DeadVisitor<'a, 'tcx> {
                 hir::ItemStruct(..) |
                 hir::ItemUnion(..) |
                 hir::ItemTrait(..) |
-                hir::ItemAutoImpl(..) |
                 hir::ItemImpl(..) => self.tcx.sess.codemap().def_span(item.span),
                 _ => item.span,
             };