Rollup merge of #60292 - varkor:ty-tuple-substs, r=nikomatsakis

Replace the `&'tcx List<Ty<'tcx>>` in `TyKind::Tuple` with `SubstsRef<'tcx>`

Part of the suggested refactoring for #42340. As expected, this is a little messy, because there are many places that the components of tuples are expected to be types, rather than arbitrary kinds. However, it should open up the way for a refactoring of `TyS` itself.

r? @nikomatsakis

Author: Centril

src/librustc/mir/tcx.rs

@@ -47,7 +47,7 @@ impl<'a, 'gcx, 'tcx> PlaceTy<'tcx> {
                 let field_def = &variant_def.fields[f.index()];
                 field_def.ty(tcx, substs)
             }
-            ty::Tuple(ref tys) => tys[f.index()],
+            ty::Tuple(ref tys) => tys[f.index()].expect_ty(),
             _ => bug!("extracting field of non-tuple non-adt: {:?}", self),
         };
         debug!("field_ty self: {:?} f: {:?} yields: {:?}", self, f, answer);

src/librustc/traits/error_reporting.rs

@@ -875,7 +875,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                 let expected_ty = expected_trait_ref.skip_binder().substs.type_at(1);
                 let expected = match expected_ty.sty {
                     ty::Tuple(ref tys) => tys.iter()
-                        .map(|t| ArgKind::from_expected_ty(t, Some(span))).collect(),
+                        .map(|t| ArgKind::from_expected_ty(t.expect_ty(), Some(span))).collect(),
                     _ => vec![ArgKind::Arg("_".to_owned(), expected_ty.to_string())],
                 };
 
@@ -1247,7 +1247,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
             let inputs = trait_ref.substs.type_at(1);
             let sig = if let ty::Tuple(inputs) = inputs.sty {
                 tcx.mk_fn_sig(
-                    inputs.iter().cloned(),
+                    inputs.iter().map(|k| k.expect_ty()),
                     tcx.mk_infer(ty::TyVar(ty::TyVid { index: 0 })),
                     false,
                     hir::Unsafety::Normal,

src/librustc/traits/query/dropck_outlives.rs

@@ -217,7 +217,7 @@ pub fn trivial_dropck_outlives<'tcx>(tcx: TyCtxt<'_, '_, 'tcx>, ty: Ty<'tcx>) ->
 
         // (T1..Tn) and closures have same properties as T1..Tn --
         // check if *any* of those are trivial.
-        ty::Tuple(ref tys) => tys.iter().all(|t| trivial_dropck_outlives(tcx, t)),
+        ty::Tuple(ref tys) => tys.iter().all(|t| trivial_dropck_outlives(tcx, t.expect_ty())),
         ty::Closure(def_id, ref substs) => substs
             .upvar_tys(def_id, tcx)
             .all(|t| trivial_dropck_outlives(tcx, t)),

src/librustc/traits/select.rs

@@ -2429,7 +2429,9 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
 
             ty::Str | ty::Slice(_) | ty::Dynamic(..) | ty::Foreign(..) => None,
 
-            ty::Tuple(tys) => Where(ty::Binder::bind(tys.last().into_iter().cloned().collect())),
+            ty::Tuple(tys) => {
+                Where(ty::Binder::bind(tys.last().into_iter().map(|k| k.expect_ty()).collect()))
+            }
 
             ty::Adt(def, substs) => {
                 let sized_crit = def.sized_constraint(self.tcx());
@@ -2503,7 +2505,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
 
             ty::Tuple(tys) => {
                 // (*) binder moved here
-                Where(ty::Binder::bind(tys.to_vec()))
+                Where(ty::Binder::bind(tys.iter().map(|k| k.expect_ty()).collect()))
             }
 
             ty::Closure(def_id, substs) => {
@@ -2590,7 +2592,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
 
             ty::Tuple(ref tys) => {
                 // (T1, ..., Tn) -- meets any bound that all of T1...Tn meet
-                tys.to_vec()
+                tys.iter().map(|k| k.expect_ty()).collect()
             }
 
             ty::Closure(def_id, ref substs) => substs.upvar_tys(def_id, self.tcx()).collect(),
@@ -3495,7 +3497,9 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
 
                 // Check that the source tuple with the target's
                 // last element is equal to the target.
-                let new_tuple = tcx.mk_tup(a_mid.iter().cloned().chain(iter::once(b_last)));
+                let new_tuple = tcx.mk_tup(
+                    a_mid.iter().map(|k| k.expect_ty()).chain(iter::once(b_last.expect_ty())),
+                );
                 let InferOk { obligations, .. } = self.infcx
                     .at(&obligation.cause, obligation.param_env)
                     .eq(target, new_tuple)
@@ -3508,7 +3512,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                     obligation.cause.clone(),
                     obligation.predicate.def_id(),
                     obligation.recursion_depth + 1,
-                    a_last,
+                    a_last.expect_ty(),
                     &[b_last.into()],
                 ));
             }

src/librustc/ty/context.rs

@@ -2431,7 +2431,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         let converted_sig = sig.map_bound(|s| {
             let params_iter = match s.inputs()[0].sty {
                 ty::Tuple(params) => {
-                    params.into_iter().cloned()
+                    params.into_iter().map(|k| k.expect_ty())
                 }
                 _ => bug!(),
             };
@@ -2573,11 +2573,15 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
 
     #[inline]
     pub fn intern_tup(self, ts: &[Ty<'tcx>]) -> Ty<'tcx> {
-        self.mk_ty(Tuple(self.intern_type_list(ts)))
+        let kinds: Vec<_> = ts.into_iter().map(|&t| Kind::from(t)).collect();
+        self.mk_ty(Tuple(self.intern_substs(&kinds)))
     }
 
     pub fn mk_tup<I: InternAs<[Ty<'tcx>], Ty<'tcx>>>(self, iter: I) -> I::Output {
-        iter.intern_with(|ts| self.mk_ty(Tuple(self.intern_type_list(ts))))
+        iter.intern_with(|ts| {
+            let kinds: Vec<_> = ts.into_iter().map(|&t| Kind::from(t)).collect();
+            self.mk_ty(Tuple(self.intern_substs(&kinds)))
+        })
     }
 
     #[inline]

src/librustc/ty/flags.rs

@@ -195,8 +195,8 @@ impl FlagComputation {
                 self.add_ty(ty);
             }
 
-            &ty::Tuple(ref ts) => {
-                self.add_tys(&ts[..]);
+            &ty::Tuple(ref substs) => {
+                self.add_substs(substs);
             }
 
             &ty::FnDef(_, substs) => {

src/librustc/ty/inhabitedness/mod.rs

@@ -181,7 +181,7 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
 
             Tuple(ref tys) => {
                 DefIdForest::union(tcx, tys.iter().map(|ty| {
-                    ty.uninhabited_from(tcx)
+                    ty.expect_ty().uninhabited_from(tcx)
                 }))
             }
 

src/librustc/ty/layout.rs

@@ -626,8 +626,9 @@ impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
                     StructKind::MaybeUnsized
                 };
 
-                univariant(&tys.iter().map(|ty| self.layout_of(ty)).collect::<Result<Vec<_>, _>>()?,
-                           &ReprOptions::default(), kind)?
+                univariant(&tys.iter().map(|k| {
+                    self.layout_of(k.expect_ty())
+                }).collect::<Result<Vec<_>, _>>()?, &ReprOptions::default(), kind)?
             }
 
             // SIMD vector types.
@@ -1723,7 +1724,7 @@ impl<'a, 'tcx, C> TyLayoutMethods<'tcx, C> for Ty<'tcx>
                 substs.field_tys(def_id, tcx).nth(i).unwrap()
             }
 
-            ty::Tuple(tys) => tys[i],
+            ty::Tuple(tys) => tys[i].expect_ty(),
 
             // SIMD vector types.
             ty::Adt(def, ..) if def.repr.simd() => {

src/librustc/ty/mod.rs

@@ -2501,7 +2501,7 @@ impl<'a, 'gcx, 'tcx> AdtDef {
             Tuple(ref tys) => {
                 match tys.last() {
                     None => vec![],
-                    Some(ty) => self.sized_constraint_for_ty(tcx, ty)
+                    Some(ty) => self.sized_constraint_for_ty(tcx, ty.expect_ty()),
                 }
             }
 

src/librustc/ty/print/mod.rs

@@ -264,7 +264,7 @@ pub fn characteristic_def_id_of_type(ty: Ty<'_>) -> Option<DefId> {
         ty::Ref(_, ty, _) => characteristic_def_id_of_type(ty),
 
         ty::Tuple(ref tys) => tys.iter()
-                                   .filter_map(|ty| characteristic_def_id_of_type(ty))
+                                   .filter_map(|ty| characteristic_def_id_of_type(ty.expect_ty()))
                                    .next(),
 
         ty::FnDef(def_id, _) |