Rollup of 7 pull requests

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -1110,7 +1110,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             tcx: TyCtxt<'tcx>,
         }
         impl<'tcx> ty::TypeFolder<TyCtxt<'tcx>> for OpaqueFolder<'tcx> {
-            fn interner(&self) -> TyCtxt<'tcx> {
+            fn cx(&self) -> TyCtxt<'tcx> {
                 self.tcx
             }
             fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {

compiler/rustc_codegen_cranelift/src/base.rs

@@ -677,21 +677,22 @@ fn codegen_stmt<'tcx>(
                     CastKind::PointerCoercion(PointerCoercion::UnsafeFnPointer),
                     ref operand,
                     to_ty,
-                )
-                | Rvalue::Cast(
-                    CastKind::PointerCoercion(PointerCoercion::MutToConstPointer),
-                    ref operand,
-                    to_ty,
-                )
-                | Rvalue::Cast(
-                    CastKind::PointerCoercion(PointerCoercion::ArrayToPointer),
-                    ref operand,
-                    to_ty,
                 ) => {
                     let to_layout = fx.layout_of(fx.monomorphize(to_ty));
                     let operand = codegen_operand(fx, operand);
                     lval.write_cvalue(fx, operand.cast_pointer_to(to_layout));
                 }
+                Rvalue::Cast(
+                    CastKind::PointerCoercion(
+                        PointerCoercion::MutToConstPointer | PointerCoercion::ArrayToPointer,
+                    ),
+                    ..,
+                ) => {
+                    bug!(
+                        "{:?} is for borrowck, and should never appear in codegen",
+                        to_place_and_rval.1
+                    );
+                }
                 Rvalue::Cast(
                     CastKind::IntToInt
                     | CastKind::FloatToFloat

compiler/rustc_codegen_ssa/src/mir/rvalue.rs

@@ -456,8 +456,12 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                             base::unsize_ptr(bx, lldata, operand.layout.ty, cast.ty, llextra);
                         OperandValue::Pair(lldata, llextra)
                     }
-                    mir::CastKind::PointerCoercion(PointerCoercion::MutToConstPointer)
-                    | mir::CastKind::PtrToPtr
+                    mir::CastKind::PointerCoercion(
+                        PointerCoercion::MutToConstPointer | PointerCoercion::ArrayToPointer,
+                    ) => {
+                        bug!("{kind:?} is for borrowck, and should never appear in codegen");
+                    }
+                    mir::CastKind::PtrToPtr
                         if bx.cx().is_backend_scalar_pair(operand.layout) =>
                     {
                         if let OperandValue::Pair(data_ptr, meta) = operand.val {
@@ -477,9 +481,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                             base::cast_to_dyn_star(bx, lldata, operand.layout, cast.ty, llextra);
                         OperandValue::Pair(lldata, llextra)
                     }
-                    mir::CastKind::PointerCoercion(
-                        PointerCoercion::MutToConstPointer | PointerCoercion::ArrayToPointer,
-                    )
                     | mir::CastKind::IntToInt
                     | mir::CastKind::FloatToInt
                     | mir::CastKind::FloatToFloat

compiler/rustc_const_eval/src/interpret/cast.rs

@@ -70,9 +70,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             CastKind::PointerCoercion(
                 PointerCoercion::MutToConstPointer | PointerCoercion::ArrayToPointer,
             ) => {
-                // These are NOPs, but can be wide pointers.
-                let v = self.read_immediate(src)?;
-                self.write_immediate(*v, dest)?;
+                bug!("{cast_kind:?} casts are for borrowck only, not runtime MIR");
             }
 
             CastKind::PointerCoercion(PointerCoercion::ReifyFnPointer) => {

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -397,7 +397,7 @@ struct RemapLateBound<'a, 'tcx> {
 }
 
 impl<'tcx> TypeFolder<TyCtxt<'tcx>> for RemapLateBound<'_, 'tcx> {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
@@ -790,13 +790,13 @@ impl<'tcx, E> TypeFolder<TyCtxt<'tcx>> for ImplTraitInTraitCollector<'_, 'tcx, E
 where
     E: 'tcx,
 {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.ocx.infcx.tcx
     }
 
     fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
         if let ty::Alias(ty::Projection, proj) = ty.kind()
-            && self.interner().is_impl_trait_in_trait(proj.def_id)
+            && self.cx().is_impl_trait_in_trait(proj.def_id)
         {
             if let Some((ty, _)) = self.types.get(&proj.def_id) {
                 return *ty;
@@ -810,9 +810,9 @@ where
             self.types.insert(proj.def_id, (infer_ty, proj.args));
             // Recurse into bounds
             for (pred, pred_span) in self
-                .interner()
+                .cx()
                 .explicit_item_bounds(proj.def_id)
-                .iter_instantiated_copied(self.interner(), proj.args)
+                .iter_instantiated_copied(self.cx(), proj.args)
             {
                 let pred = pred.fold_with(self);
                 let pred = self.ocx.normalize(
@@ -822,7 +822,7 @@ where
                 );
 
                 self.ocx.register_obligation(traits::Obligation::new(
-                    self.interner(),
+                    self.cx(),
                     ObligationCause::new(
                         self.span,
                         self.body_id,
@@ -853,7 +853,7 @@ struct RemapHiddenTyRegions<'tcx> {
 impl<'tcx> ty::FallibleTypeFolder<TyCtxt<'tcx>> for RemapHiddenTyRegions<'tcx> {
     type Error = ErrorGuaranteed;
 
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
@@ -2072,7 +2072,7 @@ struct ReplaceTy<'tcx> {
 }
 
 impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ReplaceTy<'tcx> {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 

compiler/rustc_hir_analysis/src/check/compare_impl_item/refine.rs

@@ -322,7 +322,7 @@ struct Anonymize<'tcx> {
 }
 
 impl<'tcx> TypeFolder<TyCtxt<'tcx>> for Anonymize<'tcx> {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -119,16 +119,7 @@ where
 
     let errors = wfcx.select_all_or_error();
     if !errors.is_empty() {
-        let err = infcx.err_ctxt().report_fulfillment_errors(errors);
-        if tcx.dcx().has_errors().is_some() {
-            return Err(err);
-        } else {
-            // HACK(oli-obk): tests/ui/specialization/min_specialization/specialize_on_type_error.rs
-            // causes an delayed bug during normalization, without reporting an error, so we need
-            // to act as if no error happened, in order to let our callers continue and report an
-            // error later in check_impl_items_against_trait.
-            return Ok(());
-        }
+        return Err(infcx.err_ctxt().report_fulfillment_errors(errors));
     }
 
     debug!(?assumed_wf_types);

compiler/rustc_hir_analysis/src/coherence/orphan.rs

@@ -539,7 +539,7 @@ struct TyVarReplacer<'cx, 'tcx> {
 }
 
 impl<'cx, 'tcx> TypeFolder<TyCtxt<'tcx>> for TyVarReplacer<'cx, 'tcx> {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }
 

compiler/rustc_hir_analysis/src/collect/item_bounds.rs

@@ -203,7 +203,7 @@ struct AssocTyToOpaque<'tcx> {
 }
 
 impl<'tcx> TypeFolder<TyCtxt<'tcx>> for AssocTyToOpaque<'tcx> {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 

compiler/rustc_hir_typeck/src/writeback.rs

@@ -793,7 +793,7 @@ impl<'cx, 'tcx> Resolver<'cx, 'tcx> {
     }
 
     fn report_error(&self, p: impl Into<ty::GenericArg<'tcx>>) -> ErrorGuaranteed {
-        if let Some(guar) = self.fcx.dcx().has_errors() {
+        if let Some(guar) = self.fcx.tainted_by_errors() {
             guar
         } else {
             self.fcx
@@ -847,7 +847,7 @@ impl<'cx, 'tcx> Resolver<'cx, 'tcx> {
 }
 
 impl<'cx, 'tcx> TypeFolder<TyCtxt<'tcx>> for Resolver<'cx, 'tcx> {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.fcx.tcx
     }
 

compiler/rustc_infer/src/infer/canonical/canonicalizer.rs

@@ -304,7 +304,7 @@ struct Canonicalizer<'cx, 'tcx> {
 }
 
 impl<'cx, 'tcx> TypeFolder<TyCtxt<'tcx>> for Canonicalizer<'cx, 'tcx> {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
@@ -773,7 +773,7 @@ impl<'cx, 'tcx> Canonicalizer<'cx, 'tcx> {
     ) -> ty::Region<'tcx> {
         let var = self.canonical_var(info, r.into());
         let br = ty::BoundRegion { var, kind: ty::BrAnon };
-        ty::Region::new_bound(self.interner(), self.binder_index, br)
+        ty::Region::new_bound(self.cx(), self.binder_index, br)
     }
 
     /// Given a type variable `ty_var` of the given kind, first check

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

@@ -158,7 +158,7 @@ struct ClosureEraser<'tcx> {
 }
 
 impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ClosureEraser<'tcx> {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 

compiler/rustc_infer/src/infer/freshen.rs

@@ -100,7 +100,7 @@ impl<'a, 'tcx> TypeFreshener<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for TypeFreshener<'a, 'tcx> {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }
 
@@ -117,7 +117,7 @@ impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for TypeFreshener<'a, 'tcx> {
             | ty::RePlaceholder(..)
             | ty::ReStatic
             | ty::ReError(_)
-            | ty::ReErased => self.interner().lifetimes.re_erased,
+            | ty::ReErased => self.cx().lifetimes.re_erased,
         }
     }
 

compiler/rustc_infer/src/infer/mod.rs

@@ -1719,7 +1719,7 @@ struct InferenceLiteralEraser<'tcx> {
 }
 
 impl<'tcx> TypeFolder<TyCtxt<'tcx>> for InferenceLiteralEraser<'tcx> {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
@@ -1859,7 +1859,7 @@ fn replace_param_and_infer_args_with_placeholder<'tcx>(
     }
 
     impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ReplaceParamAndInferWithPlaceholder<'tcx> {
-        fn interner(&self) -> TyCtxt<'tcx> {
+        fn cx(&self) -> TyCtxt<'tcx> {
             self.tcx
         }
 

compiler/rustc_infer/src/infer/resolve.rs

@@ -24,7 +24,7 @@ impl<'a, 'tcx> OpportunisticVarResolver<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for OpportunisticVarResolver<'a, 'tcx> {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }
 
@@ -66,7 +66,7 @@ impl<'a, 'tcx> OpportunisticRegionResolver<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for OpportunisticRegionResolver<'a, 'tcx> {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }
 
@@ -85,7 +85,7 @@ impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for OpportunisticRegionResolver<'a, 'tcx
                 .inner
                 .borrow_mut()
                 .unwrap_region_constraints()
-                .opportunistic_resolve_var(TypeFolder::interner(self), vid),
+                .opportunistic_resolve_var(TypeFolder::cx(self), vid),
             _ => r,
         }
     }
@@ -121,7 +121,7 @@ struct FullTypeResolver<'a, 'tcx> {
 impl<'a, 'tcx> FallibleTypeFolder<TyCtxt<'tcx>> for FullTypeResolver<'a, 'tcx> {
     type Error = FixupError;
 
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }
 

compiler/rustc_infer/src/infer/snapshot/fudge.rs

@@ -183,7 +183,7 @@ pub struct InferenceFudger<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for InferenceFudger<'a, 'tcx> {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }
 

compiler/rustc_lint/src/non_local_def.rs

@@ -390,7 +390,7 @@ struct ReplaceLocalTypesWithInfer<'a, 'tcx, F: FnMut(DefId) -> bool> {
 impl<'a, 'tcx, F: FnMut(DefId) -> bool> TypeFolder<TyCtxt<'tcx>>
     for ReplaceLocalTypesWithInfer<'a, 'tcx, F>
 {
-    fn interner(&self) -> TyCtxt<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }
 

compiler/rustc_middle/src/mir/syntax.rs

@@ -127,6 +127,9 @@ pub enum AnalysisPhase {
     /// * [`StatementKind::AscribeUserType`]
     /// * [`StatementKind::Coverage`] with [`CoverageKind::BlockMarker`] or [`CoverageKind::SpanMarker`]
     /// * [`Rvalue::Ref`] with `BorrowKind::Fake`
+    /// * [`CastKind::PointerCoercion`] with any of the following:
+    ///   * [`PointerCoercion::ArrayToPointer`]
+    ///   * [`PointerCoercion::MutToConstPointer`]
     ///
     /// Furthermore, `Deref` projections must be the first projection within any place (if they
     /// appear at all)
@@ -1284,8 +1287,7 @@ pub enum Rvalue<'tcx> {
     ///
     /// This allows for casts from/to a variety of types.
     ///
-    /// **FIXME**: Document exactly which `CastKind`s allow which types of casts. Figure out why
-    /// `ArrayToPointer` and `MutToConstPointer` are special.
+    /// **FIXME**: Document exactly which `CastKind`s allow which types of casts.
     Cast(CastKind, Operand<'tcx>, Ty<'tcx>),
 
     /// * `Offset` has the same semantics as [`offset`](pointer::offset), except that the second
@@ -1365,6 +1367,13 @@ pub enum CastKind {
     PointerWithExposedProvenance,
     /// Pointer related casts that are done by coercions. Note that reference-to-raw-ptr casts are
     /// translated into `&raw mut/const *r`, i.e., they are not actually casts.
+    ///
+    /// The following are allowed in [`AnalysisPhase::Initial`] as they're needed for borrowck,
+    /// but after that are forbidden (including in all phases of runtime MIR):
+    /// * [`PointerCoercion::ArrayToPointer`]
+    /// * [`PointerCoercion::MutToConstPointer`]
+    ///
+    /// Both are runtime nops, so should be [`CastKind::PtrToPtr`] instead in runtime MIR.
     PointerCoercion(PointerCoercion),
     /// Cast into a dyn* object.
     DynStar,