Rollup of 8 pull requests

compiler/rustc_borrowck/src/type_check/relate_tys.rs

@@ -309,7 +309,7 @@ impl<'me, 'bccx, 'tcx> NllTypeRelating<'me, 'bccx, 'tcx> {
 }
 
 impl<'bccx, 'tcx> TypeRelation<TyCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx> {
-    fn tcx(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.type_checker.infcx.tcx
     }
 
@@ -370,7 +370,7 @@ impl<'bccx, 'tcx> TypeRelation<TyCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx
                     // shouldn't ever fail. Instead, it unconditionally emits an
                     // alias-relate goal.
                     assert!(!self.type_checker.infcx.next_trait_solver());
-                    self.tcx().dcx().span_delayed_bug(
+                    self.cx().dcx().span_delayed_bug(
                         self.span(),
                         "failure to relate an opaque to itself should result in an error later on",
                     );
@@ -540,7 +540,7 @@ impl<'bccx, 'tcx> PredicateEmittingRelation<InferCtxt<'tcx>> for NllTypeRelating
         &mut self,
         obligations: impl IntoIterator<Item: ty::Upcast<TyCtxt<'tcx>, ty::Predicate<'tcx>>>,
     ) {
-        let tcx = self.tcx();
+        let tcx = self.cx();
         let param_env = self.param_env();
         self.register_goals(
             obligations.into_iter().map(|to_pred| Goal::new(tcx, param_env, to_pred)),
@@ -559,7 +559,7 @@ impl<'bccx, 'tcx> PredicateEmittingRelation<InferCtxt<'tcx>> for NllTypeRelating
                     .into_iter()
                     .map(|goal| {
                         Obligation::new(
-                            self.tcx(),
+                            self.cx(),
                             ObligationCause::dummy_with_span(self.span()),
                             goal.param_env,
                             goal.predicate,

compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs

@@ -1257,14 +1257,12 @@ pub fn prohibit_assoc_item_constraint(
             };
 
             // Now emit the suggestion
-            if let Ok(suggestion) = tcx.sess.source_map().span_to_snippet(removal_span) {
-                e.span_suggestion_verbose(
-                    removal_span,
-                    format!("consider removing this associated item {}", constraint.kind.descr()),
-                    suggestion,
-                    Applicability::MaybeIncorrect,
-                );
-            }
+            e.span_suggestion_verbose(
+                removal_span,
+                format!("consider removing this associated item {}", constraint.kind.descr()),
+                "",
+                Applicability::MaybeIncorrect,
+            );
         };
 
         // Suggest replacing the associated item binding with a generic argument.
@@ -1340,11 +1338,13 @@ pub fn prohibit_assoc_item_constraint(
                                 format!("<{lifetimes}{type_with_constraints}>"),
                             )
                         };
-                        let suggestions =
-                            vec![param_decl, (constraint.span, format!("{}", matching_param.name))];
+                        let suggestions = vec![
+                            param_decl,
+                            (constraint.span.with_lo(constraint.ident.span.hi()), String::new()),
+                        ];
 
                         err.multipart_suggestion_verbose(
-                            format!("declare the type parameter right after the `impl` keyword"),
+                            "declare the type parameter right after the `impl` keyword",
                             suggestions,
                             Applicability::MaybeIncorrect,
                         );

compiler/rustc_infer/src/error_reporting/infer/mod.rs

@@ -1930,7 +1930,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
 struct SameTypeModuloInfer<'a, 'tcx>(&'a InferCtxt<'tcx>);
 
 impl<'tcx> TypeRelation<TyCtxt<'tcx>> for SameTypeModuloInfer<'_, 'tcx> {
-    fn tcx(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.0.tcx
     }
 

compiler/rustc_infer/src/infer/outlives/test_type_match.rs

@@ -137,7 +137,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for MatchAgainstHigherRankedOutlives<'tcx>
         "MatchAgainstHigherRankedOutlives"
     }
 
-    fn tcx(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 

compiler/rustc_infer/src/infer/relate/generalize.rs

@@ -372,7 +372,7 @@ impl<'tcx> Generalizer<'_, 'tcx> {
 
         let is_nested_alias = mem::replace(&mut self.in_alias, true);
         let result = match self.relate(alias, alias) {
-            Ok(alias) => Ok(alias.to_ty(self.tcx())),
+            Ok(alias) => Ok(alias.to_ty(self.cx())),
             Err(e) => {
                 if is_nested_alias {
                     return Err(e);
@@ -397,7 +397,7 @@ impl<'tcx> Generalizer<'_, 'tcx> {
 }
 
 impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Generalizer<'_, 'tcx> {
-    fn tcx(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }
 
@@ -417,7 +417,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Generalizer<'_, 'tcx> {
             // (e.g., #41849).
             relate::relate_args_invariantly(self, a_arg, b_arg)
         } else {
-            let tcx = self.tcx();
+            let tcx = self.cx();
             let opt_variances = tcx.variances_of(item_def_id);
             relate::relate_args_with_variances(
                 self,
@@ -525,7 +525,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Generalizer<'_, 'tcx> {
                             }
 
                             debug!("replacing original vid={:?} with new={:?}", vid, new_var_id);
-                            Ok(Ty::new_var(self.tcx(), new_var_id))
+                            Ok(Ty::new_var(self.cx(), new_var_id))
                         }
                     }
                 }
@@ -654,7 +654,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Generalizer<'_, 'tcx> {
                             {
                                 variable_table.union(vid, new_var_id);
                             }
-                            Ok(ty::Const::new_var(self.tcx(), new_var_id))
+                            Ok(ty::Const::new_var(self.cx(), new_var_id))
                         }
                     }
                 }
@@ -672,7 +672,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Generalizer<'_, 'tcx> {
                     args,
                     args,
                 )?;
-                Ok(ty::Const::new_unevaluated(self.tcx(), ty::UnevaluatedConst { def, args }))
+                Ok(ty::Const::new_unevaluated(self.cx(), ty::UnevaluatedConst { def, args }))
             }
             ty::ConstKind::Placeholder(placeholder) => {
                 if self.for_universe.can_name(placeholder.universe) {

compiler/rustc_infer/src/infer/relate/glb.rs

@@ -27,7 +27,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Glb<'_, '_, 'tcx> {
         "Glb"
     }
 
-    fn tcx(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.fields.tcx()
     }
 
@@ -61,7 +61,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Glb<'_, '_, 'tcx> {
         let origin = SubregionOrigin::Subtype(Box::new(self.fields.trace.clone()));
         // GLB(&'static u8, &'a u8) == &RegionLUB('static, 'a) u8 == &'static u8
         Ok(self.fields.infcx.inner.borrow_mut().unwrap_region_constraints().lub_regions(
-            self.tcx(),
+            self.cx(),
             origin,
             a,
             b,

compiler/rustc_infer/src/infer/relate/lub.rs

@@ -27,7 +27,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Lub<'_, '_, 'tcx> {
         "Lub"
     }
 
-    fn tcx(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.fields.tcx()
     }
 
@@ -61,7 +61,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Lub<'_, '_, 'tcx> {
         let origin = SubregionOrigin::Subtype(Box::new(self.fields.trace.clone()));
         // LUB(&'static u8, &'a u8) == &RegionGLB('static, 'a) u8 == &'a u8
         Ok(self.fields.infcx.inner.borrow_mut().unwrap_region_constraints().glb_regions(
-            self.tcx(),
+            self.cx(),
             origin,
             a,
             b,

compiler/rustc_infer/src/infer/relate/type_relating.rs

@@ -32,7 +32,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for TypeRelating<'_, '_, 'tcx> {
         "TypeRelating"
     }
 
-    fn tcx(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.fields.infcx.tcx
     }
 
@@ -48,7 +48,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for TypeRelating<'_, '_, 'tcx> {
             // (e.g., #41849).
             relate_args_invariantly(self, a_arg, b_arg)
         } else {
-            let tcx = self.tcx();
+            let tcx = self.cx();
             let opt_variances = tcx.variances_of(item_def_id);
             relate_args_with_variances(self, item_def_id, opt_variances, a_arg, b_arg, false)
         }
@@ -88,7 +88,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for TypeRelating<'_, '_, 'tcx> {
                         // can't make progress on `A <: B` if both A and B are
                         // type variables, so record an obligation.
                         self.fields.goals.push(Goal::new(
-                            self.tcx(),
+                            self.cx(),
                             self.fields.param_env,
                             ty::Binder::dummy(ty::PredicateKind::Subtype(ty::SubtypePredicate {
                                 a_is_expected: true,
@@ -101,7 +101,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for TypeRelating<'_, '_, 'tcx> {
                         // can't make progress on `B <: A` if both A and B are
                         // type variables, so record an obligation.
                         self.fields.goals.push(Goal::new(
-                            self.tcx(),
+                            self.cx(),
                             self.fields.param_env,
                             ty::Binder::dummy(ty::PredicateKind::Subtype(ty::SubtypePredicate {
                                 a_is_expected: false,
@@ -134,7 +134,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for TypeRelating<'_, '_, 'tcx> {
 
             (&ty::Error(e), _) | (_, &ty::Error(e)) => {
                 infcx.set_tainted_by_errors(e);
-                return Ok(Ty::new_error(self.tcx(), e));
+                return Ok(Ty::new_error(self.cx(), e));
             }
 
             (

compiler/rustc_macros/src/lift.rs

@@ -45,7 +45,7 @@ pub fn lift_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStre
         quote! {
             type Lifted = #lifted;
 
-            fn lift_to_tcx(self, __tcx: ::rustc_middle::ty::TyCtxt<'__lifted>) -> Option<#lifted> {
+            fn lift_to_interner(self, __tcx: ::rustc_middle::ty::TyCtxt<'__lifted>) -> Option<#lifted> {
                 Some(match self { #body })
             }
         },

compiler/rustc_middle/src/macros.rs

@@ -59,7 +59,7 @@ macro_rules! TrivialLiftImpls {
         $(
             impl<'tcx> $crate::ty::Lift<$crate::ty::TyCtxt<'tcx>> for $ty {
                 type Lifted = Self;
-                fn lift_to_tcx(self, _: $crate::ty::TyCtxt<'tcx>) -> Option<Self> {
+                fn lift_to_interner(self, _: $crate::ty::TyCtxt<'tcx>) -> Option<Self> {
                     Some(self)
                 }
             }

compiler/rustc_middle/src/ty/context.rs

@@ -1484,7 +1484,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn lift<T: Lift<TyCtxt<'tcx>>>(self, value: T) -> Option<T::Lifted> {
-        value.lift_to_tcx(self)
+        value.lift_to_interner(self)
     }
 
     /// Creates a type context. To use the context call `fn enter` which
@@ -2087,7 +2087,7 @@ macro_rules! nop_lift {
     ($set:ident; $ty:ty => $lifted:ty) => {
         impl<'a, 'tcx> Lift<TyCtxt<'tcx>> for $ty {
             type Lifted = $lifted;
-            fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
+            fn lift_to_interner(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
                 // Assert that the set has the right type.
                 // Given an argument that has an interned type, the return type has the type of
                 // the corresponding interner set. This won't actually return anything, we're
@@ -2122,7 +2122,7 @@ macro_rules! nop_list_lift {
     ($set:ident; $ty:ty => $lifted:ty) => {
         impl<'a, 'tcx> Lift<TyCtxt<'tcx>> for &'a List<$ty> {
             type Lifted = &'tcx List<$lifted>;
-            fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
+            fn lift_to_interner(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
                 // Assert that the set has the right type.
                 if false {
                     let _x: &InternedSet<'tcx, List<$lifted>> = &tcx.interners.$set;
@@ -2160,7 +2160,7 @@ macro_rules! nop_slice_lift {
     ($ty:ty => $lifted:ty) => {
         impl<'a, 'tcx> Lift<TyCtxt<'tcx>> for &'a [$ty] {
             type Lifted = &'tcx [$lifted];
-            fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
+            fn lift_to_interner(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
                 if self.is_empty() {
                     return Some(&[]);
                 }

compiler/rustc_middle/src/ty/generic_args.rs

@@ -308,7 +308,7 @@ impl<'tcx> GenericArg<'tcx> {
 impl<'a, 'tcx> Lift<TyCtxt<'tcx>> for GenericArg<'a> {
     type Lifted = GenericArg<'tcx>;
 
-    fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
+    fn lift_to_interner(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
         match self.unpack() {
             GenericArgKind::Lifetime(lt) => tcx.lift(lt).map(|lt| lt.into()),
             GenericArgKind::Type(ty) => tcx.lift(ty).map(|ty| ty.into()),

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -1214,11 +1214,14 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
             && let ty::Alias(_, alias_ty) =
                 self.tcx().fn_sig(fn_def_id).skip_binder().output().skip_binder().kind()
             && alias_ty.def_id == def_id
+            && let generics = self.tcx().generics_of(fn_def_id)
+            // FIXME(return_type_notation): We only support lifetime params for now.
+            && generics.own_params.iter().all(|param| matches!(param.kind, ty::GenericParamDefKind::Lifetime))
         {
-            let num_args = self.tcx().generics_of(fn_def_id).count();
+            let num_args = generics.count();
             write!(self, " {{ ")?;
             self.print_def_path(fn_def_id, &args[..num_args])?;
-            write!(self, "() }}")?;
+            write!(self, "(..) }}")?;
         }
 
         Ok(())

compiler/rustc_middle/src/ty/relate.rs

@@ -69,7 +69,7 @@ impl<'tcx> Relate<TyCtxt<'tcx>> for ty::Pattern<'tcx> {
                 if inc_a != inc_b {
                     todo!()
                 }
-                Ok(relation.tcx().mk_pat(ty::PatternKind::Range { start, end, include_end: inc_a }))
+                Ok(relation.cx().mk_pat(ty::PatternKind::Range { start, end, include_end: inc_a }))
             }
         }
     }
@@ -81,7 +81,7 @@ impl<'tcx> Relate<TyCtxt<'tcx>> for &'tcx ty::List<ty::PolyExistentialPredicate<
         a: Self,
         b: Self,
     ) -> RelateResult<'tcx, Self> {
-        let tcx = relation.tcx();
+        let tcx = relation.cx();
 
         // FIXME: this is wasteful, but want to do a perf run to see how slow it is.
         // We need to perform this deduplication as we sometimes generate duplicate projections

compiler/rustc_middle/src/ty/structural_impls.rs

@@ -283,7 +283,7 @@ TrivialTypeTraversalAndLiftImpls! {
 
 impl<'tcx, T: Lift<TyCtxt<'tcx>>> Lift<TyCtxt<'tcx>> for Option<T> {
     type Lifted = Option<T::Lifted>;
-    fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
+    fn lift_to_interner(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
         Some(match self {
             Some(x) => Some(tcx.lift(x)?),
             None => None,
@@ -293,7 +293,7 @@ impl<'tcx, T: Lift<TyCtxt<'tcx>>> Lift<TyCtxt<'tcx>> for Option<T> {
 
 impl<'a, 'tcx> Lift<TyCtxt<'tcx>> for Term<'a> {
     type Lifted = ty::Term<'tcx>;
-    fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
+    fn lift_to_interner(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
         match self.unpack() {
             TermKind::Ty(ty) => tcx.lift(ty).map(Into::into),
             TermKind::Const(c) => tcx.lift(c).map(Into::into),

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -2240,11 +2240,11 @@ impl<'a> Parser<'a> {
                     }
                     _ => {
                         // Otherwise, try to get a type and emit a suggestion.
-                        if let Some(ty) = pat.to_ty() {
+                        if let Some(_) = pat.to_ty() {
                             err.span_suggestion_verbose(
-                                pat.span,
+                                pat.span.shrink_to_lo(),
                                 "explicitly ignore the parameter name",
-                                format!("_: {}", pprust::ty_to_string(&ty)),
+                                "_: ".to_string(),
                                 Applicability::MachineApplicable,
                             );
                             err.note(rfc_note);
@@ -2256,7 +2256,7 @@ impl<'a> Parser<'a> {
 
             // `fn foo(a, b) {}`, `fn foo(a<x>, b<y>) {}` or `fn foo(usize, usize) {}`
             if first_param {
-                err.span_suggestion(
+                err.span_suggestion_verbose(
                     self_span,
                     "if this is a `self` type, give it a parameter name",
                     self_sugg,
@@ -2266,14 +2266,14 @@ impl<'a> Parser<'a> {
             // Avoid suggesting that `fn foo(HashMap<u32>)` is fixed with a change to
             // `fn foo(HashMap: TypeName<u32>)`.
             if self.token != token::Lt {
-                err.span_suggestion(
+                err.span_suggestion_verbose(
                     param_span,
                     "if this is a parameter name, give it a type",
                     param_sugg,
                     Applicability::HasPlaceholders,
                 );
             }
-            err.span_suggestion(
+            err.span_suggestion_verbose(
                 type_span,
                 "if this is a type, explicitly ignore the parameter name",
                 type_sugg,