Remove adt_def from PlaceTy and make it a struct

Author: tmandry

src/librustc/mir/tcx.rs

@@ -4,21 +4,17 @@
  */
 
 use crate::mir::*;
-use crate::ty::subst::{Subst, SubstsRef};
-use crate::ty::{self, AdtDef, Ty, TyCtxt};
+use crate::ty::subst::Subst;
+use crate::ty::{self, Ty, TyCtxt};
 use crate::ty::layout::VariantIdx;
 use crate::hir;
 use crate::ty::util::IntTypeExt;
 
 #[derive(Copy, Clone, Debug)]
-pub enum PlaceTy<'tcx> {
-    /// Normal type.
-    Ty { ty: Ty<'tcx> },
-
-    /// Downcast to a particular variant of an enum.
-    Downcast { adt_def: &'tcx AdtDef,
-               substs: SubstsRef<'tcx>,
-               variant_index: VariantIdx },
+pub struct PlaceTy<'tcx> {
+    pub ty: Ty<'tcx>,
+    /// Downcast to a particular variant of an enum, if included.
+    pub variant_index: Option<VariantIdx>,
 }
 
 static_assert!(PLACE_TY_IS_3_PTRS_LARGE:
@@ -27,16 +23,7 @@ static_assert!(PLACE_TY_IS_3_PTRS_LARGE:
 
 impl<'a, 'gcx, 'tcx> PlaceTy<'tcx> {
     pub fn from_ty(ty: Ty<'tcx>) -> PlaceTy<'tcx> {
-        PlaceTy::Ty { ty }
-    }
-
-    pub fn to_ty(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> Ty<'tcx> {
-        match *self {
-            PlaceTy::Ty { ty } =>
-                ty,
-            PlaceTy::Downcast { adt_def, substs, variant_index: _ } =>
-                tcx.mk_adt(adt_def, substs),
-        }
+        PlaceTy { ty, variant_index: None }
     }
 
     /// `place_ty.field_ty(tcx, f)` computes the type at a given field
@@ -48,21 +35,20 @@ impl<'a, 'gcx, 'tcx> PlaceTy<'tcx> {
     /// Note that the resulting type has not been normalized.
     pub fn field_ty(self, tcx: TyCtxt<'a, 'gcx, 'tcx>, f: &Field) -> Ty<'tcx>
     {
-        // Pass `0` here so it can be used as a "default" variant_index in first arm below
-        let answer = match (self, VariantIdx::new(0)) {
-            (PlaceTy::Ty {
-                ty: &ty::TyS { sty: ty::TyKind::Adt(adt_def, substs), .. } }, variant_index) |
-            (PlaceTy::Downcast { adt_def, substs, variant_index }, _) => {
-                let variant_def = &adt_def.variants[variant_index];
+        let answer = match self.ty.sty {
+            ty::TyKind::Adt(adt_def, substs) => {
+                let variant_def = match self.variant_index {
+                    None => adt_def.non_enum_variant(),
+                    Some(variant_index) => {
+                        assert!(adt_def.is_enum());
+                        &adt_def.variants[variant_index]
+                    }
+                };
                 let field_def = &variant_def.fields[f.index()];
                 field_def.ty(tcx, substs)
             }
-            (PlaceTy::Ty { ty }, _) => {
-                match ty.sty {
-                    ty::Tuple(ref tys) => tys[f.index()],
-                    _ => bug!("extracting field of non-tuple non-adt: {:?}", self),
-                }
-            }
+            ty::Tuple(ref tys) => tys[f.index()],
+            _ => bug!("extracting field of non-tuple non-adt: {:?}", self),
         };
         debug!("field_ty self: {:?} f: {:?} yields: {:?}", self, f, answer);
         answer
@@ -94,61 +80,43 @@ impl<'a, 'gcx, 'tcx> PlaceTy<'tcx> {
     {
         let answer = match *elem {
             ProjectionElem::Deref => {
-                let ty = self.to_ty(tcx)
+                let ty = self.ty
                              .builtin_deref(true)
                              .unwrap_or_else(|| {
                                  bug!("deref projection of non-dereferencable ty {:?}", self)
                              })
                              .ty;
-                PlaceTy::Ty {
-                    ty,
-                }
+                PlaceTy::from_ty(ty)
             }
             ProjectionElem::Index(_) | ProjectionElem::ConstantIndex { .. } =>
-                PlaceTy::Ty {
-                    ty: self.to_ty(tcx).builtin_index().unwrap()
-                },
+                PlaceTy::from_ty(self.ty.builtin_index().unwrap()),
             ProjectionElem::Subslice { from, to } => {
-                let ty = self.to_ty(tcx);
-                PlaceTy::Ty {
-                    ty: match ty.sty {
-                        ty::Array(inner, size) => {
-                            let size = size.unwrap_usize(tcx);
-                            let len = size - (from as u64) - (to as u64);
-                            tcx.mk_array(inner, len)
-                        }
-                        ty::Slice(..) => ty,
-                        _ => {
-                            bug!("cannot subslice non-array type: `{:?}`", self)
-                        }
-                    }
-                }
-            }
-            ProjectionElem::Downcast(_name, index) =>
-                match self.to_ty(tcx).sty {
-                    ty::Adt(adt_def, substs) => {
-                        assert!(adt_def.is_enum());
-                        assert!(index.as_usize() < adt_def.variants.len());
-                        PlaceTy::Downcast { adt_def,
-                                            substs,
-                                            variant_index: index }
+                PlaceTy::from_ty(match self.ty.sty {
+                    ty::Array(inner, size) => {
+                        let size = size.unwrap_usize(tcx);
+                        let len = size - (from as u64) - (to as u64);
+                        tcx.mk_array(inner, len)
                     }
+                    ty::Slice(..) => self.ty,
                     _ => {
-                        bug!("cannot downcast non-ADT type: `{:?}`", self)
+                        bug!("cannot subslice non-array type: `{:?}`", self)
                     }
-                },
+                })
+            }
+            ProjectionElem::Downcast(_name, index) =>
+                PlaceTy { ty: self.ty, variant_index: Some(index) },
             ProjectionElem::Field(ref f, ref fty) =>
-                PlaceTy::Ty { ty: handle_field(&self, f, fty) },
+                PlaceTy::from_ty(handle_field(&self, f, fty)),
         };
         debug!("projection_ty self: {:?} elem: {:?} yields: {:?}", self, elem, answer);
         answer
     }
 }
 
-EnumTypeFoldableImpl! {
+BraceStructTypeFoldableImpl! {
     impl<'tcx> TypeFoldable<'tcx> for PlaceTy<'tcx> {
-        (PlaceTy::Ty) { ty },
-        (PlaceTy::Downcast) { adt_def, substs, variant_index },
+        ty,
+        variant_index,
     }
 }
 
@@ -158,9 +126,9 @@ impl<'tcx> Place<'tcx> {
     {
         match *self {
             Place::Base(PlaceBase::Local(index)) =>
-                PlaceTy::Ty { ty: local_decls.local_decls()[index].ty },
+                PlaceTy::from_ty(local_decls.local_decls()[index].ty),
             Place::Base(PlaceBase::Static(ref data)) =>
-                PlaceTy::Ty { ty: data.ty },
+                PlaceTy::from_ty(data.ty),
             Place::Projection(ref proj) =>
                 proj.base.ty(local_decls, tcx).projection_ty(tcx, &proj.elem),
         }
@@ -185,7 +153,7 @@ impl<'tcx> Place<'tcx> {
         match place {
             Place::Projection(ref proj) => match proj.elem {
                 ProjectionElem::Field(field, _ty) => {
-                    let base_ty = proj.base.ty(mir, *tcx).to_ty(*tcx);
+                    let base_ty = proj.base.ty(mir, *tcx).ty;
 
                     if (base_ty.is_closure() || base_ty.is_generator()) &&
                         (!by_ref || mir.upvar_decls[field.index()].by_ref)
@@ -217,7 +185,7 @@ impl<'tcx> Rvalue<'tcx> {
                 tcx.mk_array(operand.ty(local_decls, tcx), count)
             }
             Rvalue::Ref(reg, bk, ref place) => {
-                let place_ty = place.ty(local_decls, tcx).to_ty(tcx);
+                let place_ty = place.ty(local_decls, tcx).ty;
                 tcx.mk_ref(reg,
                     ty::TypeAndMut {
                         ty: place_ty,
@@ -243,7 +211,7 @@ impl<'tcx> Rvalue<'tcx> {
                 operand.ty(local_decls, tcx)
             }
             Rvalue::Discriminant(ref place) => {
-                let ty = place.ty(local_decls, tcx).to_ty(tcx);
+                let ty = place.ty(local_decls, tcx).ty;
                 if let ty::Adt(adt_def, _) = ty.sty {
                     adt_def.repr.discr_type().to_ty(tcx)
                 } else {
@@ -292,7 +260,7 @@ impl<'tcx> Operand<'tcx> {
     {
         match self {
             &Operand::Copy(ref l) |
-            &Operand::Move(ref l) => l.ty(local_decls, tcx).to_ty(tcx),
+            &Operand::Move(ref l) => l.ty(local_decls, tcx).ty,
             &Operand::Constant(ref c) => c.ty,
         }
     }

src/librustc_codegen_ssa/mir/analyze.rs

@@ -172,14 +172,14 @@ impl<'mir, 'a: 'mir, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> Visitor<'tcx>
                 // ZSTs don't require any actual memory access.
                 let elem_ty = base_ty
                     .projection_ty(cx.tcx(), &proj.elem)
-                    .to_ty(cx.tcx());
+                    .ty;
                 let elem_ty = self.fx.monomorphize(&elem_ty);
                 if cx.layout_of(elem_ty).is_zst() {
                     return;
                 }
 
                 if let mir::ProjectionElem::Field(..) = proj.elem {
-                    let layout = cx.layout_of(base_ty.to_ty(cx.tcx()));
+                    let layout = cx.layout_of(base_ty.ty);
                     if cx.is_backend_immediate(layout) || cx.is_backend_scalar_pair(layout) {
                         // Recurse with the same context, instead of `Projection`,
                         // potentially stopping at non-operand projections,
@@ -247,7 +247,7 @@ impl<'mir, 'a: 'mir, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> Visitor<'tcx>
             PlaceContext::MutatingUse(MutatingUseContext::Drop) => {
                 let ty = mir::Place::Base(mir::PlaceBase::Local(local)).ty(self.fx.mir,
                                                                            self.fx.cx.tcx());
-                let ty = self.fx.monomorphize(&ty.to_ty(self.fx.cx.tcx()));
+                let ty = self.fx.monomorphize(&ty.ty);
 
                 // Only need the place if we're actually dropping it.
                 if self.fx.cx.type_needs_drop(ty) {

src/librustc_codegen_ssa/mir/block.rs

@@ -301,7 +301,7 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         target: mir::BasicBlock,
         unwind: Option<mir::BasicBlock>,
     ) {
-        let ty = location.ty(self.mir, bx.tcx()).to_ty(bx.tcx());
+        let ty = location.ty(self.mir, bx.tcx()).ty;
         let ty = self.monomorphize(&ty);
         let drop_fn = monomorphize::resolve_drop_in_place(bx.tcx(), ty);
 

src/librustc_codegen_ssa/mir/place.rs

@@ -494,8 +494,8 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     mir::ProjectionElem::Subslice { from, to } => {
                         let mut subslice = cg_base.project_index(bx,
                             bx.cx().const_usize(from as u64));
-                        let projected_ty = PlaceTy::Ty { ty: cg_base.layout.ty }
-                            .projection_ty(tcx, &projection.elem).to_ty(tcx);
+                        let projected_ty = PlaceTy::from_ty(cg_base.layout.ty)
+                            .projection_ty(tcx, &projection.elem).ty;
                         subslice.layout = bx.cx().layout_of(self.monomorphize(&projected_ty));
 
                         if subslice.layout.is_unsized() {
@@ -523,6 +523,6 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     pub fn monomorphized_place_ty(&self, place: &mir::Place<'tcx>) -> Ty<'tcx> {
         let tcx = self.cx.tcx();
         let place_ty = place.ty(self.mir, tcx);
-        self.monomorphize(&place_ty.to_ty(tcx))
+        self.monomorphize(&place_ty.ty)
     }
 }

src/librustc_mir/borrow_check/error_reporting.rs

@@ -202,7 +202,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                 );
             }
 
-            let ty = used_place.ty(self.mir, self.infcx.tcx).to_ty(self.infcx.tcx);
+            let ty = used_place.ty(self.mir, self.infcx.tcx).ty;
             let needs_note = match ty.sty {
                 ty::Closure(id, _) => {
                     let tables = self.infcx.tcx.typeck_tables_of(id);
@@ -217,7 +217,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                 let mpi = self.move_data.moves[move_out_indices[0]].path;
                 let place = &self.move_data.move_paths[mpi].place;
 
-                let ty = place.ty(self.mir, self.infcx.tcx).to_ty(self.infcx.tcx);
+                let ty = place.ty(self.mir, self.infcx.tcx).ty;
                 let opt_name = self.describe_place_with_options(place, IncludingDowncast(true));
                 let note_msg = match opt_name {
                     Some(ref name) => format!("`{}`", name),
@@ -601,8 +601,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
         // Define a small closure that we can use to check if the type of a place
         // is a union.
         let is_union = |place: &Place<'tcx>| -> bool {
-            place.ty(self.mir, self.infcx.tcx)
-                .to_ty(self.infcx.tcx)
+            place.ty(self.mir, self.infcx.tcx).ty
                 .ty_adt_def()
                 .map(|adt| adt.is_union())
                 .unwrap_or(false)
@@ -651,7 +650,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
 
                             // Also compute the name of the union type, eg. `Foo` so we
                             // can add a helpful note with it.
-                            let ty = base.ty(self.mir, self.infcx.tcx).to_ty(self.infcx.tcx);
+                            let ty = base.ty(self.mir, self.infcx.tcx).ty;
 
                             return Some((desc_base, desc_first, desc_second, ty.to_string()));
                         },
@@ -1777,7 +1776,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
             Place::Projection(ref proj) => match proj.elem {
                 ProjectionElem::Deref => self.describe_field(&proj.base, field),
                 ProjectionElem::Downcast(_, variant_index) => {
-                    let base_ty = base.ty(self.mir, self.infcx.tcx).to_ty();
+                    let base_ty = base.ty(self.mir, self.infcx.tcx).ty;
                     self.describe_field_from_ty(&base_ty, field, Some(variant_index))
                 }
                 ProjectionElem::Field(_, field_type) => {
@@ -1878,15 +1877,15 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                         StorageDeadOrDrop::LocalStorageDead
                         | StorageDeadOrDrop::BoxedStorageDead => {
                             assert!(
-                                base.ty(self.mir, tcx).to_ty(tcx).is_box(),
+                                base.ty(self.mir, tcx).ty.is_box(),
                                 "Drop of value behind a reference or raw pointer"
                             );
                             StorageDeadOrDrop::BoxedStorageDead
                         }
                         StorageDeadOrDrop::Destructor(_) => base_access,
                     },
                     ProjectionElem::Field(..) | ProjectionElem::Downcast(..) => {
-                        let base_ty = base.ty(self.mir, tcx).to_ty(tcx);
+                        let base_ty = base.ty(self.mir, tcx).ty;
                         match base_ty.sty {
                             ty::Adt(def, _) if def.has_dtor(tcx) => {
                                 // Report the outermost adt with a destructor

src/librustc_mir/borrow_check/mod.rs

@@ -616,8 +616,7 @@ impl<'cx, 'gcx, 'tcx> DataflowResultsConsumer<'cx, 'tcx> for MirBorrowckCtxt<'cx
                 let drop_place_ty = drop_place.ty(self.mir, self.infcx.tcx);
 
                 // Erase the regions.
-                let drop_place_ty = self.infcx.tcx.erase_regions(&drop_place_ty)
-                    .to_ty(self.infcx.tcx);
+                let drop_place_ty = self.infcx.tcx.erase_regions(&drop_place_ty).ty;
 
                 // "Lift" into the gcx -- once regions are erased, this type should be in the
                 // global arenas; this "lift" operation basically just asserts that is true, but
@@ -1641,7 +1640,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                             // assigning to `P.f` requires `P` itself
                             // be already initialized
                             let tcx = self.infcx.tcx;
-                            match base.ty(self.mir, tcx).to_ty(tcx).sty {
+                            match base.ty(self.mir, tcx).ty.sty {
                                 ty::Adt(def, _) if def.has_dtor(tcx) => {
                                     self.check_if_path_or_subpath_is_moved(
                                         context, InitializationRequiringAction::Assignment,
@@ -1746,7 +1745,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                 // no move out from an earlier location) then this is an attempt at initialization
                 // of the union - we should error in that case.
                 let tcx = this.infcx.tcx;
-                if let ty::TyKind::Adt(def, _) = base.ty(this.mir, tcx).to_ty(tcx).sty {
+                if let ty::TyKind::Adt(def, _) = base.ty(this.mir, tcx).ty.sty {
                     if def.is_union() {
                         if this.move_data.path_map[mpi].iter().any(|moi| {
                             this.move_data.moves[*moi].source.is_predecessor_of(
@@ -2007,7 +2006,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
             Place::Projection(ref proj) => {
                 match proj.elem {
                     ProjectionElem::Deref => {
-                        let base_ty = proj.base.ty(self.mir, self.infcx.tcx).to_ty(self.infcx.tcx);
+                        let base_ty = proj.base.ty(self.mir, self.infcx.tcx).ty;
 
                         // Check the kind of deref to decide
                         match base_ty.sty {

src/librustc_mir/borrow_check/move_errors.rs

@@ -266,7 +266,7 @@ impl<'a, 'gcx, 'tcx> MirBorrowckCtxt<'a, 'gcx, 'tcx> {
                         // Inspect the type of the content behind the
                         // borrow to provide feedback about why this
                         // was a move rather than a copy.
-                        let ty = place.ty(self.mir, self.infcx.tcx).to_ty(self.infcx.tcx);
+                        let ty = place.ty(self.mir, self.infcx.tcx).ty;
                         let is_upvar_field_projection =
                             self.prefixes(&original_path, PrefixSet::All)
                             .any(|p| p.is_upvar_field_projection(self.mir, &self.infcx.tcx)
@@ -530,7 +530,7 @@ impl<'a, 'gcx, 'tcx> MirBorrowckCtxt<'a, 'gcx, 'tcx> {
                     // We're only interested in assignments (in particular, where the
                     // assignment came from - was it an `Rc` or `Arc`?).
                     if let StatementKind::Assign(_, box Rvalue::Ref(_, _, source)) = &stmt.kind {
-                        let ty = source.ty(self.mir, self.infcx.tcx).to_ty(self.infcx.tcx);
+                        let ty = source.ty(self.mir, self.infcx.tcx).ty;
                         let ty = match ty.sty {
                             ty::TyKind::Ref(_, ty, _) => ty,
                             _ => ty,
@@ -555,7 +555,7 @@ impl<'a, 'gcx, 'tcx> MirBorrowckCtxt<'a, 'gcx, 'tcx> {
                             _ => continue,
                         };
 
-                        let ty = source.ty(self.mir, self.infcx.tcx).to_ty(self.infcx.tcx);
+                        let ty = source.ty(self.mir, self.infcx.tcx).ty;
                         let ty = match ty.sty {
                             ty::TyKind::Ref(_, ty, _) => ty,
                             _ => ty,
@@ -581,7 +581,7 @@ impl<'a, 'gcx, 'tcx> MirBorrowckCtxt<'a, 'gcx, 'tcx> {
             base,
             elem: ProjectionElem::Deref,
         }) = place {
-            if base.ty(self.mir, self.infcx.tcx).to_ty(self.infcx.tcx).is_unsafe_ptr() {
+            if base.ty(self.mir, self.infcx.tcx).ty.is_unsafe_ptr() {
                 return BorrowedContentSource::DerefRawPointer;
             }
         }