Remove VariantDef::parent_did

src/librustc/middle/mem_categorization.rs

@@ -215,7 +215,7 @@ impl<'tcx> cmt_<'tcx> {
         };
         let variant_def = match self.cat {
             Categorization::Downcast(_, variant_did) => {
-                adt_def.variant_with_variant_id(variant_did)
+                adt_def.variant_with_id(variant_did)
             }
             _ => {
                 assert_eq!(adt_def.variants.len(), 1);

src/librustc/mir/mod.rs

@@ -2405,13 +2405,12 @@ impl<'tcx> Debug for Rvalue<'tcx> {
 
                     AggregateKind::Adt(adt_def, variant, substs, _user_ty, _) => {
                         let variant_def = &adt_def.variants[variant];
-                        let did = variant_def.variant_did_or_parent_struct_did();
 
                         let f = &mut *fmt;
                         ty::tls::with(|tcx| {
                             let substs = tcx.lift(&substs).expect("could not lift for printing");
                             FmtPrinter::new(tcx, f, Namespace::ValueNS)
-                                .print_def_path(did, substs)?;
+                                .print_def_path(variant_def.def_id, substs)?;
                             Ok(())
                         })?;
 

src/librustc/ty/inhabitedness/mod.rs

@@ -104,33 +104,6 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     fn ty_inhabitedness_forest(self, ty: Ty<'tcx>) -> DefIdForest {
         ty.uninhabited_from(self)
     }
-
-    pub fn is_enum_variant_uninhabited_from(self,
-                                            module: DefId,
-                                            variant: &'tcx VariantDef,
-                                            substs: SubstsRef<'tcx>)
-                                            -> bool
-    {
-        self.variant_inhabitedness_forest(variant, substs).contains(self, module)
-    }
-
-    pub fn is_variant_uninhabited_from_all_modules(self,
-                                                   variant: &'tcx VariantDef,
-                                                   substs: SubstsRef<'tcx>)
-                                                   -> bool
-    {
-        !self.variant_inhabitedness_forest(variant, substs).is_empty()
-    }
-
-    fn variant_inhabitedness_forest(self, variant: &'tcx VariantDef, substs: SubstsRef<'tcx>)
-                                    -> DefIdForest {
-        // Determine the ADT kind:
-        let adt_def_id = self.adt_def_id_of_variant(variant);
-        let adt_kind = self.adt_def(adt_def_id).adt_kind();
-
-        // Compute inhabitedness forest:
-        variant.uninhabited_from(self, substs, adt_kind)
-    }
 }
 
 impl<'a, 'gcx, 'tcx> AdtDef {
@@ -148,7 +121,7 @@ impl<'a, 'gcx, 'tcx> AdtDef {
 
 impl<'a, 'gcx, 'tcx> VariantDef {
     /// Calculate the forest of DefIds from which this variant is visibly uninhabited.
-    fn uninhabited_from(
+    pub fn uninhabited_from(
         &self,
         tcx: TyCtxt<'a, 'gcx, 'tcx>,
         substs: SubstsRef<'tcx>,

src/librustc/ty/mod.rs

@@ -1810,12 +1810,12 @@ bitflags! {
 /// Definition of a variant -- a struct's fields or a enum variant.
 #[derive(Debug)]
 pub struct VariantDef {
-    /// `DefId` that identifies this enum variant. If this `VariantDef` is part of a struct or
-    /// union then this is `None`.
-    variant_did: Option<DefId>,
-    /// `DefId` that identifies this enum variant or struct's constructor. If this is a
-    /// `Struct`-variant then this is `None`.
-    ctor_did: Option<DefId>,
+    /// `DefId` that identifies the variant itself.
+    /// If this variant belongs to a struct or union, then this is a copy of its `DefId`.
+    pub def_id: DefId,
+    /// `DefId` that identifies the variant's constructor.
+    /// If this variant is a struct variant, then this is `None`.
+    pub ctor_def_id: Option<DefId>,
     /// Variant or struct name.
     pub ident: Ident,
     /// Discriminant of this variant.
@@ -1824,11 +1824,6 @@ pub struct VariantDef {
     pub fields: Vec<FieldDef>,
     /// Type of constructor of variant.
     pub ctor_kind: CtorKind,
-    /// `DefId` of the parent `AdtDef` representing the struct or enum. This is required as there
-    /// is a valid scenario where this type represents a `Struct`-struct and both `ctor_did` and
-    /// `variant_did` would be `None` and we would still want a way to get back to the original
-    /// `AdtDef`.
-    parent_did: DefId,
     /// Flags of the variant (e.g. is field list non-exhaustive)?
     flags: VariantFlags,
     /// Recovered?
@@ -1856,7 +1851,7 @@ impl<'a, 'gcx, 'tcx> VariantDef {
         tcx: TyCtxt<'a, 'gcx, 'tcx>,
         ident: Ident,
         variant_did: Option<DefId>,
-        ctor_did: Option<DefId>,
+        ctor_def_id: Option<DefId>,
         discr: VariantDiscr,
         fields: Vec<FieldDef>,
         ctor_kind: CtorKind,
@@ -1865,9 +1860,9 @@ impl<'a, 'gcx, 'tcx> VariantDef {
         recovered: bool,
     ) -> Self {
         debug!(
-            "VariantDef::new(ident = {:?}, variant_did = {:?}, ctor_did = {:?}, discr = {:?},
+            "VariantDef::new(ident = {:?}, variant_did = {:?}, ctor_def_id = {:?}, discr = {:?},
              fields = {:?}, ctor_kind = {:?}, adt_kind = {:?}, parent_did = {:?})",
-             ident, variant_did, ctor_did, discr, fields, ctor_kind, adt_kind, parent_did,
+             ident, variant_did, ctor_def_id, discr, fields, ctor_kind, adt_kind, parent_did,
         );
 
         let mut flags = VariantFlags::NO_VARIANT_FLAGS;
@@ -1877,14 +1872,13 @@ impl<'a, 'gcx, 'tcx> VariantDef {
         }
 
         VariantDef {
-            variant_did,
-            ctor_did,
+            def_id: variant_did.unwrap_or(parent_did),
+            ctor_def_id,
             ident,
             discr,
             fields,
             ctor_kind,
             flags,
-            parent_did,
             recovered,
         }
     }
@@ -1894,62 +1888,16 @@ impl<'a, 'gcx, 'tcx> VariantDef {
     pub fn is_field_list_non_exhaustive(&self) -> bool {
         self.flags.intersects(VariantFlags::IS_FIELD_LIST_NON_EXHAUSTIVE)
     }
-
-    /// Returns `true` if this `VariantDef` represents a enum's variant.
-    #[inline]
-    pub fn is_enum_variant(&self) -> bool {
-        self.variant_did.is_some()
-    }
-
-    /// Returns `true` if this `VariantDef` represents a struct.
-    #[inline]
-    pub fn is_struct(&self) -> bool {
-        !self.is_enum_variant()
-    }
-
-    /// Returns the `DefId` of this variant if this `VariantDef` represents an enum's variant, or
-    /// returns the `DefId` of the parent struct.
-    #[inline]
-    pub fn variant_did_or_parent_struct_did(&self) -> DefId {
-        self.variant_did.unwrap_or(self.parent_did)
-    }
-
-    /// Returns `true` if the variant is defined in the local crate.
-    #[inline]
-    pub fn is_local(&self) -> bool {
-        self.variant_did_or_parent_struct_did().krate == LOCAL_CRATE
-    }
-
-    /// Returns the `DefId` of this variant if this `VariantDef` represents an enum's variant or
-    /// panics.
-    #[inline]
-    pub fn variant_did(&self) -> DefId {
-        self.variant_did.expect("enum variant without a variant id")
-    }
-
-    /// Returns the `DefId` of this variant's constructor if this is a unit or
-    /// tuple-variant/struct.
-    #[inline]
-    pub fn ctor_did(&self) -> Option<DefId> {
-        self.ctor_did
-    }
-
-    /// Returns the `AdtDef` representing the struct or enum associated with this `VariantDef`.
-    #[inline]
-    pub fn adt_def(&self, tcx: TyCtxt<'a, 'tcx, 'gcx>) -> &'tcx AdtDef {
-        tcx.adt_def(self.parent_did)
-    }
 }
 
 impl_stable_hash_for!(struct VariantDef {
-    variant_did,
-    ctor_did,
+    def_id,
+    ctor_def_id,
     ident -> (ident.name),
     discr,
     fields,
     ctor_kind,
     flags,
-    parent_did,
     recovered
 });
 
@@ -2204,7 +2152,7 @@ impl<'a, 'gcx, 'tcx> AdtDef {
             AdtKind::Struct => AdtFlags::IS_STRUCT,
         };
 
-        if kind == AdtKind::Struct && variants[VariantIdx::new(0)].ctor_did.is_some() {
+        if kind == AdtKind::Struct && variants[VariantIdx::new(0)].ctor_def_id.is_some() {
             flags |= AdtFlags::HAS_CTOR;
         }
 
@@ -2351,51 +2299,29 @@ impl<'a, 'gcx, 'tcx> AdtDef {
             self.variants.iter().all(|v| v.fields.is_empty())
     }
 
-    pub fn variant_with_variant_id(&self, vid: DefId) -> &VariantDef {
-        self.variants
-            .iter()
-            .find(|v| v.variant_did.map(|did| did == vid).unwrap_or(false))
-            .expect("variant_with_variant_id: unknown variant")
+    pub fn variant_with_id(&self, vid: DefId) -> &VariantDef {
+        self.variants.iter().find(|v| v.def_id == vid)
+            .expect("variant_with_id: unknown variant")
     }
 
     pub fn variant_with_ctor_id(&self, cid: DefId) -> &VariantDef {
-        self.variants
-            .iter()
-            .find(|v| v.ctor_did.map(|did| did == cid).unwrap_or(false))
+        self.variants.iter().find(|v| v.ctor_def_id == Some(cid))
             .expect("variant_with_ctor_id: unknown variant")
     }
 
-    pub fn variant_index_with_variant_id(&self, vid: DefId) -> VariantIdx {
-        self.variants
-            .iter_enumerated()
-            .find(|(_, v)| v.variant_did.map(|did| did == vid).unwrap_or(false))
-            .expect("variant_index_with_variant_id: unknown variant")
-            .0
+    pub fn variant_index_with_id(&self, vid: DefId) -> VariantIdx {
+        self.variants.iter_enumerated().find(|(_, v)| v.def_id == vid)
+            .expect("variant_index_with_id: unknown variant").0
     }
 
     pub fn variant_index_with_ctor_id(&self, cid: DefId) -> VariantIdx {
-        self.variants
-            .iter_enumerated()
-            .find(|(_, v)| v.ctor_did.map(|did| did == cid).unwrap_or(false))
-            .expect("variant_index_with_ctor_id: unknown variant")
-            .0
-    }
-
-    pub fn variant_index_with_ctor_or_variant_id(&self, id: DefId) -> VariantIdx {
-        self.variants
-            .iter_enumerated()
-            .find(|(_, v)| {
-                let ctor = v.ctor_did.map(|did| did == id);
-                let variant = v.variant_did.map(|did| did == id);
-                ctor.or(variant).unwrap_or(false)
-            })
-            .expect("variant_index_with_ctor_or_variant_id: unknown variant")
-            .0
+        self.variants.iter_enumerated().find(|(_, v)| v.ctor_def_id == Some(cid))
+            .expect("variant_index_with_ctor_id: unknown variant").0
     }
 
     pub fn variant_of_def(&self, def: Def) -> &VariantDef {
         match def {
-            Def::Variant(vid) => self.variant_with_variant_id(vid),
+            Def::Variant(vid) => self.variant_with_id(vid),
             Def::Ctor(hir::CtorOf::Variant, cid, ..) => self.variant_with_ctor_id(cid),
             Def::Struct(..) | Def::Ctor(..) | Def::Union(..) |
             Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) |
@@ -2933,8 +2859,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
 
     pub fn find_field_index(self, ident: Ident, variant: &VariantDef) -> Option<usize> {
         variant.fields.iter().position(|field| {
-            let did = variant.variant_did.unwrap_or(variant.parent_did);
-            self.adjust_ident(ident, did, hir::DUMMY_HIR_ID).0 == field.ident.modern()
+            self.adjust_ident(ident, variant.def_id, hir::DUMMY_HIR_ID).0 == field.ident.modern()
         })
     }
 
@@ -3011,7 +2936,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         match def {
             Def::Variant(did) => {
                 let enum_did = self.parent(did).unwrap();
-                self.adt_def(enum_did).variant_with_variant_id(did)
+                self.adt_def(enum_did).variant_with_id(did)
             }
             Def::Struct(did) | Def::Union(did) => {
                 self.adt_def(did).non_enum_variant()
@@ -3029,11 +2954,6 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         }
     }
 
-    /// Given a `VariantDef`, returns the def-id of the `AdtDef` of which it is a part.
-    pub fn adt_def_id_of_variant(self, variant_def: &'tcx VariantDef) -> DefId {
-        variant_def.parent_did
-    }
-
     pub fn item_name(self, id: DefId) -> InternedString {
         if id.index == CRATE_DEF_INDEX {
             self.original_crate_name(id.krate).as_interned_str()

src/librustc_metadata/encoder.rs

@@ -579,13 +579,13 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
         let tcx = self.tcx;
         let def = tcx.adt_def(enum_did);
         let variant = &def.variants[index];
-        let def_id = variant.variant_did();
+        let def_id = variant.def_id;
         debug!("IsolatedEncoder::encode_enum_variant_info({:?})", def_id);
 
         let data = VariantData {
             ctor_kind: variant.ctor_kind,
             discr: variant.discr,
-            ctor: variant.ctor_did().map(|did| did.index),
+            ctor: variant.ctor_def_id.map(|did| did.index),
             ctor_sig: None,
         };
 
@@ -628,7 +628,7 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
         let tcx = self.tcx;
         let def = tcx.adt_def(enum_did);
         let variant = &def.variants[index];
-        let def_id = variant.ctor_did().unwrap();
+        let def_id = variant.ctor_def_id.unwrap();
         debug!("IsolatedEncoder::encode_enum_variant_ctor({:?})", def_id);
 
         let data = VariantData {
@@ -726,9 +726,7 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
         let def_id = field.did;
         debug!("IsolatedEncoder::encode_field({:?})", def_id);
 
-        let variant_id = tcx.hir()
-            .as_local_hir_id(variant.variant_did_or_parent_struct_did())
-            .unwrap();
+        let variant_id = tcx.hir().as_local_hir_id(variant.def_id).unwrap();
         let variant_data = tcx.hir().expect_variant_data(variant_id);
 
         Entry {
@@ -1218,9 +1216,8 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
                 hir::ItemKind::Enum(..) => {
                     let def = self.tcx.adt_def(def_id);
                     self.lazy_seq(def.variants.iter().map(|v| {
-                        let did = v.variant_did();
-                        assert!(did.is_local());
-                        did.index
+                        assert!(v.def_id.is_local());
+                        v.def_id.index
                     }))
                 }
                 hir::ItemKind::Struct(..) |
@@ -1813,12 +1810,12 @@ impl<'a, 'b, 'tcx> IndexBuilder<'a, 'b, 'tcx> {
 
                 let def = self.tcx.adt_def(def_id);
                 for (i, variant) in def.variants.iter_enumerated() {
-                    self.record(variant.variant_did(),
+                    self.record(variant.def_id,
                                 IsolatedEncoder::encode_enum_variant_info,
                                 (def_id, Untracked(i)));
 
-                    if let Some(ctor_hir_did) = variant.ctor_did() {
-                        self.record(ctor_hir_did,
+                    if let Some(ctor_def_id) = variant.ctor_def_id {
+                        self.record(ctor_def_id,
                                     IsolatedEncoder::encode_enum_variant_ctor,
                                     (def_id, Untracked(i)));
                     }

src/librustc_mir/build/matches/simplify.rs

@@ -163,7 +163,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                     i == variant_index || {
                         self.hir.tcx().features().never_type &&
                         self.hir.tcx().features().exhaustive_patterns &&
-                        self.hir.tcx().is_variant_uninhabited_from_all_modules(v, substs)
+                        !v.uninhabited_from(self.hir.tcx(), substs, adt_def.adt_kind()).is_empty()
                     }
                 });
                 if irrefutable {

src/librustc_mir/hair/cx/expr.rs

@@ -486,7 +486,7 @@ fn make_mirror_unadjusted<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
                                 Def::Variant(variant_id) => {
                                     assert!(base.is_none());
 
-                                    let index = adt.variant_index_with_variant_id(variant_id);
+                                    let index = adt.variant_index_with_id(variant_id);
                                     let user_provided_types = cx.tables().user_provided_types();
                                     let user_ty = user_provided_types.get(expr.hir_id)
                                         .map(|u_ty| *u_ty);