Rollup of 4 pull requests

src/libcore/convert.rs

@@ -554,6 +554,18 @@ impl<T> From<T> for T {
     fn from(t: T) -> T { t }
 }
 
+/// **Stability note:** This impl does not yet exist, but we are
+/// "reserving space" to add it in the future. See
+/// [rust-lang/rust#64715][#64715] for details.
+///
+/// [#64715]: https://github.com/rust-lang/rust/issues/64715
+#[stable(feature = "convert_infallible", since = "1.34.0")]
+#[cfg(not(bootstrap))]
+#[rustc_reservation_impl="permitting this impl would forbid us from adding \
+`impl<T> From<!> for T` later; see rust-lang/rust#64715 for details"]
+impl<T> From<!> for T {
+    fn from(t: !) -> T { t }
+}
 
 // TryFrom implies TryInto
 #[stable(feature = "try_from", since = "1.34.0")]

src/librustc/infer/canonical/canonicalizer.rs

@@ -343,7 +343,7 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for Canonicalizer<'cx, 'tcx> {
     }
 
     fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
-        match t.sty {
+        match t.kind {
             ty::Infer(ty::TyVar(vid)) => {
                 debug!("canonical: type var found with vid {:?}", vid);
                 match self.infcx.unwrap().probe_ty_var(vid) {

src/librustc/infer/canonical/query_response.rs

@@ -471,7 +471,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
             match result_value.unpack() {
                 UnpackedKind::Type(result_value) => {
                     // e.g., here `result_value` might be `?0` in the example above...
-                    if let ty::Bound(debruijn, b) = result_value.sty {
+                    if let ty::Bound(debruijn, b) = result_value.kind {
                         // ...in which case we would set `canonical_vars[0]` to `Some(?U)`.
 
                         // We only allow a `ty::INNERMOST` index in substitutions.

src/librustc/infer/combine.rs

@@ -70,7 +70,7 @@ impl<'infcx, 'tcx> InferCtxt<'infcx, 'tcx> {
     {
         let a_is_expected = relation.a_is_expected();
 
-        match (&a.sty, &b.sty) {
+        match (&a.kind, &b.kind) {
             // Relate integral variables to other types
             (&ty::Infer(ty::IntVar(a_id)), &ty::Infer(ty::IntVar(b_id))) => {
                 self.int_unification_table
@@ -486,7 +486,7 @@ impl TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
         // any other type variable related to `vid` via
         // subtyping. This is basically our "occurs check", preventing
         // us from creating infinitely sized types.
-        match t.sty {
+        match t.kind {
             ty::Infer(ty::TyVar(vid)) => {
                 let mut variables = self.infcx.type_variables.borrow_mut();
                 let vid = variables.root_var(vid);

src/librustc/infer/equate.rs

@@ -68,7 +68,7 @@ impl TypeRelation<'tcx> for Equate<'combine, 'infcx, 'tcx> {
 
         debug!("{}.tys: replacements ({:?}, {:?})", self.tag(), a, b);
 
-        match (&a.sty, &b.sty) {
+        match (&a.kind, &b.kind) {
             (&ty::Infer(TyVar(a_id)), &ty::Infer(TyVar(b_id))) => {
                 infcx.type_variables.borrow_mut().equate(a_id, b_id);
             }

src/librustc/infer/error_reporting/mod.rs

@@ -589,7 +589,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 // if they are both "path types", there's a chance of ambiguity
                 // due to different versions of the same crate
                 if let (&ty::Adt(exp_adt, _), &ty::Adt(found_adt, _))
-                     = (&exp_found.expected.sty, &exp_found.found.sty)
+                     = (&exp_found.expected.kind, &exp_found.found.kind)
                 {
                     report_path_match(err, exp_adt.did, found_adt.did);
                 }
@@ -803,7 +803,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 self.highlight_outer(&mut t1_out, &mut t2_out, path, sub, i, &other_ty);
                 return Some(());
             }
-            if let &ty::Adt(def, _) = &ta.sty {
+            if let &ty::Adt(def, _) = &ta.kind {
                 let path_ = self.tcx.def_path_str(def.did.clone());
                 if path_ == other_path {
                     self.highlight_outer(&mut t1_out, &mut t2_out, path, sub, i, &other_ty);
@@ -868,7 +868,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     /// relevant differences, and return two representation of those types for highlighted printing.
     fn cmp(&self, t1: Ty<'tcx>, t2: Ty<'tcx>) -> (DiagnosticStyledString, DiagnosticStyledString) {
         fn equals<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
-            match (&a.sty, &b.sty) {
+            match (&a.kind, &b.kind) {
                 (a, b) if *a == *b => true,
                 (&ty::Int(_), &ty::Infer(ty::InferTy::IntVar(_)))
                 | (&ty::Infer(ty::InferTy::IntVar(_)), &ty::Int(_))
@@ -902,7 +902,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
             s.push_normal(ty.to_string());
         }
 
-        match (&t1.sty, &t2.sty) {
+        match (&t1.kind, &t2.kind) {
             (&ty::Adt(def1, sub1), &ty::Adt(def2, sub2)) => {
                 let sub_no_defaults_1 = self.strip_generic_default_params(def1.did, sub1);
                 let sub_no_defaults_2 = self.strip_generic_default_params(def2.did, sub2);
@@ -1138,7 +1138,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
             match (terr, is_simple_error, expected == found) {
                 (&TypeError::Sorts(ref values), false, true) => {
                     let sort_string = | a_type: Ty<'tcx> |
-                        if let ty::Opaque(def_id, _) = a_type.sty {
+                        if let ty::Opaque(def_id, _) = a_type.kind {
                             format!(" (opaque type at {})", self.tcx.sess.source_map()
                                 .mk_substr_filename(self.tcx.def_span(def_id)))
                         } else {
@@ -1179,9 +1179,9 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         exp_found: &ty::error::ExpectedFound<Ty<'tcx>>,
         diag: &mut DiagnosticBuilder<'tcx>,
     ) {
-        match (&exp_found.expected.sty, &exp_found.found.sty) {
+        match (&exp_found.expected.kind, &exp_found.found.kind) {
             (ty::Adt(exp_def, exp_substs), ty::Ref(_, found_ty, _)) => {
-                if let ty::Adt(found_def, found_substs) = found_ty.sty {
+                if let ty::Adt(found_def, found_substs) = found_ty.kind {
                     let path_str = format!("{:?}", exp_def);
                     if exp_def == &found_def {
                         let opt_msg = "you can convert from `&Option<T>` to `Option<&T>` using \
@@ -1203,9 +1203,9 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                         {
                             let mut show_suggestion = true;
                             for (exp_ty, found_ty) in exp_substs.types().zip(found_substs.types()) {
-                                match exp_ty.sty {
+                                match exp_ty.kind {
                                     ty::Ref(_, exp_ty, _) => {
-                                        match (&exp_ty.sty, &found_ty.sty) {
+                                        match (&exp_ty.kind, &found_ty.kind) {
                                             (_, ty::Param(_)) |
                                             (_, ty::Infer(_)) |
                                             (ty::Param(_), _) |

src/librustc/infer/error_reporting/need_type_info.rs

@@ -44,7 +44,7 @@ impl<'a, 'tcx> FindLocalByTypeVisitor<'a, 'tcx> {
             Some(ty) => {
                 let ty = self.infcx.resolve_vars_if_possible(&ty);
                 if ty.walk().any(|inner_ty| {
-                    inner_ty == self.target_ty || match (&inner_ty.sty, &self.target_ty.sty) {
+                    inner_ty == self.target_ty || match (&inner_ty.kind, &self.target_ty.kind) {
                         (&Infer(TyVar(a_vid)), &Infer(TyVar(b_vid))) => {
                             self.infcx
                                 .type_variables
@@ -151,7 +151,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         ty: Ty<'tcx>,
         highlight: Option<ty::print::RegionHighlightMode>,
     ) -> (String, Option<Span>) {
-        if let ty::Infer(ty::TyVar(ty_vid)) = ty.sty {
+        if let ty::Infer(ty::TyVar(ty_vid)) = ty.kind {
             let ty_vars = self.type_variables.borrow();
             let var_origin = ty_vars.var_origin(ty_vid);
             if let TypeVariableOriginKind::TypeParameterDefinition(name) = var_origin.kind {
@@ -219,7 +219,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         };
 
         let ty_msg = match local_visitor.found_ty {
-            Some(ty::TyS { sty: ty::Closure(def_id, substs), .. }) => {
+            Some(ty::TyS { kind: ty::Closure(def_id, substs), .. }) => {
                 let fn_sig = substs.closure_sig(*def_id, self.tcx);
                 let args = closure_args(&fn_sig);
                 let ret = fn_sig.output().skip_binder().to_string();
@@ -254,7 +254,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         );
 
         let suffix = match local_visitor.found_ty {
-            Some(ty::TyS { sty: ty::Closure(def_id, substs), .. }) => {
+            Some(ty::TyS { kind: ty::Closure(def_id, substs), .. }) => {
                 let fn_sig = substs.closure_sig(*def_id, self.tcx);
                 let ret = fn_sig.output().skip_binder().to_string();
 

src/librustc/infer/error_reporting/nice_region_error/util.rs

@@ -109,7 +109,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
         decl: &hir::FnDecl,
     ) -> Option<Span> {
         let ret_ty = self.tcx().type_of(scope_def_id);
-        if let ty::FnDef(_, _) = ret_ty.sty {
+        if let ty::FnDef(_, _) = ret_ty.kind {
             let sig = ret_ty.fn_sig(self.tcx());
             let late_bound_regions = self.tcx()
                 .collect_referenced_late_bound_regions(&sig.output());

src/librustc/infer/freshen.rs

@@ -153,7 +153,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for TypeFreshener<'a, 'tcx> {
 
         let tcx = self.infcx.tcx;
 
-        match t.sty {
+        match t.kind {
             ty::Infer(ty::TyVar(v)) => {
                 let opt_ty = self.infcx.type_variables.borrow_mut().probe(v).known();
                 self.freshen_ty(

src/librustc/infer/fudge.rs

@@ -148,7 +148,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for InferenceFudger<'a, 'tcx> {
     }
 
     fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
-        match ty.sty {
+        match ty.kind {
             ty::Infer(ty::InferTy::TyVar(vid)) => {
                 if self.type_vars.0.contains(&vid) {
                     // This variable was created during the fudging.

src/librustc/infer/lattice.rs

@@ -61,7 +61,7 @@ where
     let infcx = this.infcx();
     let a = infcx.type_variables.borrow_mut().replace_if_possible(a);
     let b = infcx.type_variables.borrow_mut().replace_if_possible(b);
-    match (&a.sty, &b.sty) {
+    match (&a.kind, &b.kind) {
         // If one side is known to be a variable and one is not,
         // create a variable (`v`) to represent the LUB. Make sure to
         // relate `v` to the non-type-variable first (by passing it

src/librustc/infer/mod.rs

@@ -614,7 +614,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     }
 
     pub fn type_var_diverges(&'a self, ty: Ty<'_>) -> bool {
-        match ty.sty {
+        match ty.kind {
             ty::Infer(ty::TyVar(vid)) => self.type_variables.borrow().var_diverges(vid),
             _ => false,
         }
@@ -627,7 +627,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     pub fn type_is_unconstrained_numeric(&'a self, ty: Ty<'_>) -> UnconstrainedNumeric {
         use crate::ty::error::UnconstrainedNumeric::Neither;
         use crate::ty::error::UnconstrainedNumeric::{UnconstrainedFloat, UnconstrainedInt};
-        match ty.sty {
+        match ty.kind {
             ty::Infer(ty::IntVar(vid)) => {
                 if self.int_unification_table
                     .borrow_mut()
@@ -1563,7 +1563,7 @@ impl<'a, 'tcx> ShallowResolver<'a, 'tcx> {
     }
 
     pub fn shallow_resolve(&mut self, typ: Ty<'tcx>) -> Ty<'tcx> {
-        match typ.sty {
+        match typ.kind {
             ty::Infer(ty::TyVar(v)) => {
                 // Not entirely obvious: if `typ` is a type variable,
                 // it can be resolved to an int/float variable, which
@@ -1604,7 +1604,7 @@ impl<'a, 'tcx> ShallowResolver<'a, 'tcx> {
     // are extremely hot.
     #[inline(always)]
     pub fn shallow_resolve_changed(&mut self, typ: Ty<'tcx>) -> bool {
-        match typ.sty {
+        match typ.kind {
             ty::Infer(ty::TyVar(v)) => {
                 use self::type_variable::TypeVariableValue;
 

src/librustc/infer/nll_relate/mod.rs

@@ -274,7 +274,7 @@ where
         use crate::traits::WhereClause;
         use syntax_pos::DUMMY_SP;
 
-        match value_ty.sty {
+        match value_ty.kind {
             ty::Projection(other_projection_ty) => {
                 let var = self.infcx.next_ty_var(TypeVariableOrigin {
                     kind: TypeVariableOriginKind::MiscVariable,
@@ -328,7 +328,7 @@ where
         // This only presently applies to chalk integration, as NLL
         // doesn't permit type variables to appear on both sides (and
         // doesn't use lazy norm).
-        match value_ty.sty {
+        match value_ty.kind {
             ty::Infer(ty::TyVar(value_vid)) => {
                 // Two type variables: just equate them.
                 self.infcx
@@ -548,7 +548,7 @@ where
             b = self.infcx.shallow_resolve(b);
         }
 
-        match (&a.sty, &b.sty) {
+        match (&a.kind, &b.kind) {
             (_, &ty::Infer(ty::TyVar(vid))) => {
                 if D::forbid_inference_vars() {
                     // Forbid inference variables in the RHS.
@@ -878,7 +878,7 @@ where
 
         debug!("TypeGeneralizer::tys(a={:?})", a);
 
-        match a.sty {
+        match a.kind {
             ty::Infer(ty::TyVar(_)) | ty::Infer(ty::IntVar(_)) | ty::Infer(ty::FloatVar(_))
                 if D::forbid_inference_vars() =>
             {

src/librustc/infer/opaque_types/mod.rs

@@ -720,7 +720,7 @@ where
             return false; // keep visiting
         }
 
-        match ty.sty {
+        match ty.kind {
             ty::Closure(def_id, ref substs) => {
                 // Skip lifetime parameters of the enclosing item(s)
 
@@ -857,7 +857,7 @@ impl TypeFolder<'tcx> for ReverseMapper<'tcx> {
     }
 
     fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
-        match ty.sty {
+        match ty.kind {
             ty::Closure(def_id, substs) => {
                 // I am a horrible monster and I pray for death. When
                 // we encounter a closure here, it is always a closure
@@ -990,7 +990,7 @@ impl<'a, 'tcx> Instantiator<'a, 'tcx> {
             ty_op: |ty| {
                 if ty.references_error() {
                     return tcx.types.err;
-                } else if let ty::Opaque(def_id, substs) = ty.sty {
+                } else if let ty::Opaque(def_id, substs) = ty.kind {
                     // Check that this is `impl Trait` type is
                     // declared by `parent_def_id` -- i.e., one whose
                     // value we are inferring.  At present, this is

src/librustc/infer/outlives/obligations.rs

@@ -403,7 +403,7 @@ where
         // 'a` in the environment but `trait Foo<'b> { type Item: 'b
         // }` in the trait definition.
         approx_env_bounds.retain(|bound| {
-            match bound.0.sty {
+            match bound.0.kind {
                 ty::Projection(projection_ty) => {
                     self.verify_bound.projection_declared_bounds_from_trait(projection_ty)
                         .all(|r| r != bound.1)

src/librustc/infer/outlives/verify.rs

@@ -44,7 +44,7 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> {
     }
 
     fn type_bound(&self, ty: Ty<'tcx>) -> VerifyBound<'tcx> {
-        match ty.sty {
+        match ty.kind {
             ty::Param(p) => self.param_bound(p),
             ty::Projection(data) => self.projection_bound(data),
             _ => self.recursive_type_bound(ty),
@@ -87,7 +87,7 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> {
         let projection_ty = GenericKind::Projection(projection_ty).to_ty(self.tcx);
         let erased_projection_ty = self.tcx.erase_regions(&projection_ty);
         self.declared_generic_bounds_from_env_with_compare_fn(|ty| {
-            if let ty::Projection(..) = ty.sty {
+            if let ty::Projection(..) = ty.kind {
                 let erased_ty = self.tcx.erase_regions(&ty);
                 erased_ty == erased_projection_ty
             } else {

src/librustc/infer/resolve.rs

@@ -118,7 +118,7 @@ impl<'a, 'tcx> TypeVisitor<'tcx> for UnresolvedTypeFinder<'a, 'tcx> {
     fn visit_ty(&mut self, t: Ty<'tcx>) -> bool {
         let t = self.infcx.shallow_resolve(t);
         if t.has_infer_types() {
-            if let ty::Infer(infer_ty) = t.sty {
+            if let ty::Infer(infer_ty) = t.kind {
                 // Since we called `shallow_resolve` above, this must
                 // be an (as yet...) unresolved inference variable.
                 let ty_var_span =
@@ -188,7 +188,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for FullTypeResolver<'a, 'tcx> {
               // defaulted tuples.
         } else {
             let t = self.infcx.shallow_resolve(t);
-            match t.sty {
+            match t.kind {
                 ty::Infer(ty::TyVar(vid)) => {
                     self.err = Some(FixupError::UnresolvedTy(vid));
                     self.tcx().types.err

src/librustc/infer/sub.rs

@@ -71,7 +71,7 @@ impl TypeRelation<'tcx> for Sub<'combine, 'infcx, 'tcx> {
         let infcx = self.fields.infcx;
         let a = infcx.type_variables.borrow_mut().replace_if_possible(a);
         let b = infcx.type_variables.borrow_mut().replace_if_possible(b);
-        match (&a.sty, &b.sty) {
+        match (&a.kind, &b.kind) {
             (&ty::Infer(TyVar(a_vid)), &ty::Infer(TyVar(b_vid))) => {
                 // Shouldn't have any LBR here, so we can safely put
                 // this under a binder below without fear of accidental

src/librustc/infer/type_variable.rs

@@ -247,7 +247,7 @@ impl<'tcx> TypeVariableTable<'tcx> {
     /// instantiated, then return the with which it was
     /// instantiated. Otherwise, returns `t`.
     pub fn replace_if_possible(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
-        match t.sty {
+        match t.kind {
             ty::Infer(ty::TyVar(v)) => {
                 match self.probe(v) {
                     TypeVariableValue::Unknown { .. } => t,

src/librustc/lint/context.rs

@@ -829,7 +829,7 @@ impl<'a, 'tcx> LateContext<'a, 'tcx> {
                 trait_ref: Option<ty::TraitRef<'tcx>>,
             ) -> Result<Self::Path, Self::Error> {
                 if trait_ref.is_none() {
-                    if let ty::Adt(def, substs) = self_ty.sty {
+                    if let ty::Adt(def, substs) = self_ty.kind {
                         return self.print_def_path(def.did, substs);
                     }
                 }