Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

8 files changed, 291 insertions, 97 deletions

diff --git a/compiler/rustc_ty_utils/src/abi.rs b/compiler/rustc_ty_utils/src/abi.rs
index 73c7eb699..91a505a72 100644
--- a/compiler/rustc_ty_utils/src/abi.rs
+++ b/compiler/rustc_ty_utils/src/abi.rs
@@ -35,7 +35,7 @@ fn fn_sig_for_fn_abi<'tcx>(
             // HACK(davidtwco,eddyb): This is a workaround for polymorphization considering
             // parameters unused if they show up in the signature, but not in the `mir::Body`
             // (i.e. due to being inside a projection that got normalized, see
-            // `src/test/ui/polymorphization/normalized_sig_types.rs`), and codegen not keeping
+            // `tests/ui/polymorphization/normalized_sig_types.rs`), and codegen not keeping
             // track of a polymorphization `ParamEnv` to allow normalizing later.
             //
             // We normalize the `fn_sig` again after substituting at a later point.
@@ -85,7 +85,7 @@ fn fn_sig_for_fn_abi<'tcx>(
                 bound_vars,
             )
         }
-        ty::Generator(_, substs, _) => {
+        ty::Generator(did, substs, _) => {
             let sig = substs.as_generator().poly_sig();
 
             let bound_vars = tcx.mk_bound_variable_kinds(
@@ -104,13 +104,45 @@ fn fn_sig_for_fn_abi<'tcx>(
             let env_ty = tcx.mk_adt(pin_adt_ref, pin_substs);
 
             let sig = sig.skip_binder();
-            let state_did = tcx.require_lang_item(LangItem::GeneratorState, None);
-            let state_adt_ref = tcx.adt_def(state_did);
-            let state_substs = tcx.intern_substs(&[sig.yield_ty.into(), sig.return_ty.into()]);
-            let ret_ty = tcx.mk_adt(state_adt_ref, state_substs);
+            // The `FnSig` and the `ret_ty` here is for a generators main
+            // `Generator::resume(...) -> GeneratorState` function in case we
+            // have an ordinary generator, or the `Future::poll(...) -> Poll`
+            // function in case this is a special generator backing an async construct.
+            let (resume_ty, ret_ty) = if tcx.generator_is_async(did) {
+                // The signature should be `Future::poll(_, &mut Context<'_>) -> Poll<Output>`
+                let poll_did = tcx.require_lang_item(LangItem::Poll, None);
+                let poll_adt_ref = tcx.adt_def(poll_did);
+                let poll_substs = tcx.intern_substs(&[sig.return_ty.into()]);
+                let ret_ty = tcx.mk_adt(poll_adt_ref, poll_substs);
+
+                // We have to replace the `ResumeTy` that is used for type and borrow checking
+                // with `&mut Context<'_>` which is used in codegen.
+                #[cfg(debug_assertions)]
+                {
+                    if let ty::Adt(resume_ty_adt, _) = sig.resume_ty.kind() {
+                        let expected_adt =
+                            tcx.adt_def(tcx.require_lang_item(LangItem::ResumeTy, None));
+                        assert_eq!(*resume_ty_adt, expected_adt);
+                    } else {
+                        panic!("expected `ResumeTy`, found `{:?}`", sig.resume_ty);
+                    };
+                }
+                let context_mut_ref = tcx.mk_task_context();
+
+                (context_mut_ref, ret_ty)
+            } else {
+                // The signature should be `Generator::resume(_, Resume) -> GeneratorState<Yield, Return>`
+                let state_did = tcx.require_lang_item(LangItem::GeneratorState, None);
+                let state_adt_ref = tcx.adt_def(state_did);
+                let state_substs = tcx.intern_substs(&[sig.yield_ty.into(), sig.return_ty.into()]);
+                let ret_ty = tcx.mk_adt(state_adt_ref, state_substs);
+
+                (sig.resume_ty, ret_ty)
+            };
+
             ty::Binder::bind_with_vars(
                 tcx.mk_fn_sig(
-                    [env_ty, sig.resume_ty].iter(),
+                    [env_ty, resume_ty].iter(),
                     &ret_ty,
                     false,
                     hir::Unsafety::Normal,
@@ -207,8 +239,7 @@ fn adjust_for_rust_scalar<'tcx>(
         return;
     }
 
-    // Scalars which have invalid values cannot be undef.
-    if !scalar.is_always_valid(&cx) {
+    if !scalar.is_uninit_valid() {
         attrs.set(ArgAttribute::NoUndef);
     }
 
@@ -234,15 +265,15 @@ fn adjust_for_rust_scalar<'tcx>(
                 PointerKind::SharedMutable | PointerKind::UniqueOwned => Size::ZERO,
             };
 
-            // `Box`, `&T`, and `&mut T` cannot be undef.
-            // Note that this only applies to the value of the pointer itself;
-            // this attribute doesn't make it UB for the pointed-to data to be undef.
-            attrs.set(ArgAttribute::NoUndef);
-
             // The aliasing rules for `Box<T>` are still not decided, but currently we emit
             // `noalias` for it. This can be turned off using an unstable flag.
             // See https://github.com/rust-lang/unsafe-code-guidelines/issues/326
-            let noalias_for_box = cx.tcx.sess.opts.unstable_opts.box_noalias.unwrap_or(true);
+            let noalias_for_box = cx.tcx.sess.opts.unstable_opts.box_noalias;
+
+            // LLVM prior to version 12 had known miscompiles in the presence of noalias attributes
+            // (see #54878), so it was conditionally disabled, but we don't support earlier
+            // versions at all anymore. We still support turning it off using -Zmutable-noalias.
+            let noalias_mut_ref = cx.tcx.sess.opts.unstable_opts.mutable_noalias;
 
             // `&mut` pointer parameters never alias other parameters,
             // or mutable global data
@@ -251,29 +282,21 @@ fn adjust_for_rust_scalar<'tcx>(
             // and can be marked as both `readonly` and `noalias`, as
             // LLVM's definition of `noalias` is based solely on memory
             // dependencies rather than pointer equality
-            //
-            // Due to past miscompiles in LLVM, we apply a separate NoAliasMutRef attribute
-            // for UniqueBorrowed arguments, so that the codegen backend can decide whether
-            // or not to actually emit the attribute. It can also be controlled with the
-            // `-Zmutable-noalias` debugging option.
             let no_alias = match kind {
-                PointerKind::SharedMutable
-                | PointerKind::UniqueBorrowed
-                | PointerKind::UniqueBorrowedPinned => false,
+                PointerKind::SharedMutable | PointerKind::UniqueBorrowedPinned => false,
+                PointerKind::UniqueBorrowed => noalias_mut_ref,
                 PointerKind::UniqueOwned => noalias_for_box,
-                PointerKind::Frozen => !is_return,
+                PointerKind::Frozen => true,
             };
-            if no_alias {
+            // We can never add `noalias` in return position; that LLVM attribute has some very surprising semantics
+            // (see <https://github.com/rust-lang/unsafe-code-guidelines/issues/385#issuecomment-1368055745>).
+            if no_alias && !is_return {
                 attrs.set(ArgAttribute::NoAlias);
             }
 
             if kind == PointerKind::Frozen && !is_return {
                 attrs.set(ArgAttribute::ReadOnly);
             }
-
-            if kind == PointerKind::UniqueBorrowed && !is_return {
-                attrs.set(ArgAttribute::NoAliasMutRef);
-            }
         }
     }
 }
diff --git a/compiler/rustc_ty_utils/src/consts.rs b/compiler/rustc_ty_utils/src/consts.rs
index f8ff31f97..a9fbad55d 100644
--- a/compiler/rustc_ty_utils/src/consts.rs
+++ b/compiler/rustc_ty_utils/src/consts.rs
@@ -267,8 +267,8 @@ struct IsThirPolymorphic<'a, 'tcx> {
     thir: &'a thir::Thir<'tcx>,
 }
 
-fn error<'tcx>(
-    tcx: TyCtxt<'tcx>,
+fn error(
+    tcx: TyCtxt<'_>,
     sub: GenericConstantTooComplexSub,
     root_span: Span,
 ) -> Result<!, ErrorGuaranteed> {
@@ -281,8 +281,8 @@ fn error<'tcx>(
     Err(reported)
 }
 
-fn maybe_supported_error<'tcx>(
-    tcx: TyCtxt<'tcx>,
+fn maybe_supported_error(
+    tcx: TyCtxt<'_>,
     sub: GenericConstantTooComplexSub,
     root_span: Span,
 ) -> Result<!, ErrorGuaranteed> {
@@ -302,13 +302,53 @@ impl<'a, 'tcx> IsThirPolymorphic<'a, 'tcx> {
         }
 
         match expr.kind {
-            thir::ExprKind::NamedConst { substs, .. } => substs.has_non_region_param(),
+            thir::ExprKind::NamedConst { substs, .. }
+            | thir::ExprKind::ConstBlock { substs, .. } => substs.has_non_region_param(),
             thir::ExprKind::ConstParam { .. } => true,
             thir::ExprKind::Repeat { value, count } => {
                 self.visit_expr(&self.thir()[value]);
                 count.has_non_region_param()
             }
-            _ => false,
+            thir::ExprKind::Scope { .. }
+            | thir::ExprKind::Box { .. }
+            | thir::ExprKind::If { .. }
+            | thir::ExprKind::Call { .. }
+            | thir::ExprKind::Deref { .. }
+            | thir::ExprKind::Binary { .. }
+            | thir::ExprKind::LogicalOp { .. }
+            | thir::ExprKind::Unary { .. }
+            | thir::ExprKind::Cast { .. }
+            | thir::ExprKind::Use { .. }
+            | thir::ExprKind::NeverToAny { .. }
+            | thir::ExprKind::Pointer { .. }
+            | thir::ExprKind::Loop { .. }
+            | thir::ExprKind::Let { .. }
+            | thir::ExprKind::Match { .. }
+            | thir::ExprKind::Block { .. }
+            | thir::ExprKind::Assign { .. }
+            | thir::ExprKind::AssignOp { .. }
+            | thir::ExprKind::Field { .. }
+            | thir::ExprKind::Index { .. }
+            | thir::ExprKind::VarRef { .. }
+            | thir::ExprKind::UpvarRef { .. }
+            | thir::ExprKind::Borrow { .. }
+            | thir::ExprKind::AddressOf { .. }
+            | thir::ExprKind::Break { .. }
+            | thir::ExprKind::Continue { .. }
+            | thir::ExprKind::Return { .. }
+            | thir::ExprKind::Array { .. }
+            | thir::ExprKind::Tuple { .. }
+            | thir::ExprKind::Adt(_)
+            | thir::ExprKind::PlaceTypeAscription { .. }
+            | thir::ExprKind::ValueTypeAscription { .. }
+            | thir::ExprKind::Closure(_)
+            | thir::ExprKind::Literal { .. }
+            | thir::ExprKind::NonHirLiteral { .. }
+            | thir::ExprKind::ZstLiteral { .. }
+            | thir::ExprKind::StaticRef { .. }
+            | thir::ExprKind::InlineAsm(_)
+            | thir::ExprKind::ThreadLocalRef(_)
+            | thir::ExprKind::Yield { .. } => false,
         }
     }
     fn pat_is_poly(&mut self, pat: &thir::Pat<'tcx>) -> bool {
@@ -349,10 +389,10 @@ impl<'a, 'tcx> visit::Visitor<'a, 'tcx> for IsThirPolymorphic<'a, 'tcx> {
 }
 
 /// Builds an abstract const, do not use this directly, but use `AbstractConst::new` instead.
-pub fn thir_abstract_const<'tcx>(
-    tcx: TyCtxt<'tcx>,
+pub fn thir_abstract_const(
+    tcx: TyCtxt<'_>,
     def: ty::WithOptConstParam<LocalDefId>,
-) -> Result<Option<ty::Const<'tcx>>, ErrorGuaranteed> {
+) -> Result<Option<ty::Const<'_>>, ErrorGuaranteed> {
     if tcx.features().generic_const_exprs {
         match tcx.def_kind(def.did) {
             // FIXME(generic_const_exprs): We currently only do this for anonymous constants,
diff --git a/compiler/rustc_ty_utils/src/implied_bounds.rs b/compiler/rustc_ty_utils/src/implied_bounds.rs
index f0d8c240e..7a2464580 100644
--- a/compiler/rustc_ty_utils/src/implied_bounds.rs
+++ b/compiler/rustc_ty_utils/src/implied_bounds.rs
@@ -6,7 +6,7 @@ pub fn provide(providers: &mut ty::query::Providers) {
     *providers = ty::query::Providers { assumed_wf_types, ..*providers };
 }
 
-fn assumed_wf_types<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::List<Ty<'tcx>> {
+fn assumed_wf_types(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::List<Ty<'_>> {
     match tcx.def_kind(def_id) {
         DefKind::Fn => {
             let sig = tcx.fn_sig(def_id);
@@ -21,14 +21,16 @@ fn assumed_wf_types<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::List<Ty
             assumed_wf_types.extend(liberated_sig.inputs_and_output);
             tcx.intern_type_list(&assumed_wf_types)
         }
-        DefKind::Impl => match tcx.impl_trait_ref(def_id) {
-            Some(trait_ref) => {
-                let types: Vec<_> = trait_ref.substs.types().collect();
-                tcx.intern_type_list(&types)
+        DefKind::Impl => {
+            match tcx.impl_trait_ref(def_id) {
+                Some(trait_ref) => {
+                    let types: Vec<_> = trait_ref.skip_binder().substs.types().collect();
+                    tcx.intern_type_list(&types)
+                }
+                // Only the impl self type
+                None => tcx.intern_type_list(&[tcx.type_of(def_id)]),
             }
-            // Only the impl self type
-            None => tcx.intern_type_list(&[tcx.type_of(def_id)]),
-        },
+        }
         DefKind::AssocConst | DefKind::AssocTy => tcx.assumed_wf_types(tcx.parent(def_id)),
         DefKind::Mod
         | DefKind::Struct
diff --git a/compiler/rustc_ty_utils/src/instance.rs b/compiler/rustc_ty_utils/src/instance.rs
index c6f2b16ca..8d46ba320 100644
--- a/compiler/rustc_ty_utils/src/instance.rs
+++ b/compiler/rustc_ty_utils/src/instance.rs
@@ -44,7 +44,13 @@ fn inner_resolve_instance<'tcx>(
 
     let result = if let Some(trait_def_id) = tcx.trait_of_item(def.did) {
         debug!(" => associated item, attempting to find impl in param_env {:#?}", param_env);
-        resolve_associated_item(tcx, def.did, param_env, trait_def_id, substs)
+        resolve_associated_item(
+            tcx,
+            def.did,
+            param_env,
+            trait_def_id,
+            tcx.normalize_erasing_regions(param_env, substs),
+        )
     } else {
         let ty = tcx.type_of(def.def_id_for_type_of());
         let item_type = tcx.subst_and_normalize_erasing_regions(substs, param_env, ty);
@@ -188,7 +194,7 @@ fn resolve_associated_item<'tcx>(
                 && trait_item_id != leaf_def.item.def_id
                 && let Some(leaf_def_item) = leaf_def.item.def_id.as_local()
             {
-                tcx.compare_assoc_const_impl_item_with_trait_item((
+                tcx.compare_impl_const((
                     leaf_def_item,
                     trait_item_id,
                 ))?;
diff --git a/compiler/rustc_ty_utils/src/layout.rs b/compiler/rustc_ty_utils/src/layout.rs
index fbc055b5d..6aa016133 100644
--- a/compiler/rustc_ty_utils/src/layout.rs
+++ b/compiler/rustc_ty_utils/src/layout.rs
@@ -1,3 +1,4 @@
+use hir::def_id::DefId;
 use rustc_hir as hir;
 use rustc_index::bit_set::BitSet;
 use rustc_index::vec::{Idx, IndexVec};
@@ -6,7 +7,7 @@ use rustc_middle::ty::layout::{
     IntegerExt, LayoutCx, LayoutError, LayoutOf, TyAndLayout, MAX_SIMD_LANES,
 };
 use rustc_middle::ty::{
-    self, subst::SubstsRef, EarlyBinder, ReprOptions, Ty, TyCtxt, TypeVisitable,
+    self, subst::SubstsRef, AdtDef, EarlyBinder, ReprOptions, Ty, TyCtxt, TypeVisitable,
 };
 use rustc_session::{DataTypeKind, FieldInfo, SizeKind, VariantInfo};
 use rustc_span::symbol::Symbol;
@@ -154,17 +155,37 @@ fn layout_of_uncached<'tcx>(
             }
 
             let unsized_part = tcx.struct_tail_erasing_lifetimes(pointee, param_env);
-            let metadata = match unsized_part.kind() {
-                ty::Foreign(..) => {
+
+            let metadata = if let Some(metadata_def_id) = tcx.lang_items().metadata_type() {
+                let metadata_ty = tcx.normalize_erasing_regions(
+                    param_env,
+                    tcx.mk_projection(metadata_def_id, [pointee]),
+                );
+                let metadata_layout = cx.layout_of(metadata_ty)?;
+                // If the metadata is a 1-zst, then the pointer is thin.
+                if metadata_layout.is_zst() && metadata_layout.align.abi.bytes() == 1 {
                     return Ok(tcx.intern_layout(LayoutS::scalar(cx, data_ptr)));
                 }
-                ty::Slice(_) | ty::Str => scalar_unit(Int(dl.ptr_sized_integer(), false)),
-                ty::Dynamic(..) => {
-                    let mut vtable = scalar_unit(Pointer);
-                    vtable.valid_range_mut().start = 1;
-                    vtable
+
+                let Abi::Scalar(metadata) = metadata_layout.abi else {
+                    return Err(LayoutError::Unknown(unsized_part));
+                };
+                metadata
+            } else {
+                match unsized_part.kind() {
+                    ty::Foreign(..) => {
+                        return Ok(tcx.intern_layout(LayoutS::scalar(cx, data_ptr)));
+                    }
+                    ty::Slice(_) | ty::Str => scalar_unit(Int(dl.ptr_sized_integer(), false)),
+                    ty::Dynamic(..) => {
+                        let mut vtable = scalar_unit(Pointer);
+                        vtable.valid_range_mut().start = 1;
+                        vtable
+                    }
+                    _ => {
+                        return Err(LayoutError::Unknown(unsized_part));
+                    }
                 }
-                _ => return Err(LayoutError::Unknown(unsized_part)),
             };
 
             // Effectively a (ptr, meta) tuple.
@@ -443,7 +464,7 @@ fn layout_of_uncached<'tcx>(
         }
 
         // Types with no meaningful known layout.
-        ty::Projection(_) | ty::Opaque(..) => {
+        ty::Alias(..) => {
             // NOTE(eddyb) `layout_of` query should've normalized these away,
             // if that was possible, so there's no reason to try again here.
             return Err(LayoutError::Unknown(ty));
@@ -488,8 +509,8 @@ enum SavedLocalEligibility {
 // of any variant.
 
 /// Compute the eligibility and assignment of each local.
-fn generator_saved_local_eligibility<'tcx>(
-    info: &GeneratorLayout<'tcx>,
+fn generator_saved_local_eligibility(
+    info: &GeneratorLayout<'_>,
 ) -> (BitSet<GeneratorSavedLocal>, IndexVec<GeneratorSavedLocal, SavedLocalEligibility>) {
     use SavedLocalEligibility::*;
 
@@ -814,27 +835,39 @@ fn record_layout_for_printing_outlined<'tcx>(
         );
     };
 
-    let adt_def = match *layout.ty.kind() {
-        ty::Adt(ref adt_def, _) => {
+    match *layout.ty.kind() {
+        ty::Adt(adt_def, _) => {
             debug!("print-type-size t: `{:?}` process adt", layout.ty);
-            adt_def
+            let adt_kind = adt_def.adt_kind();
+            let adt_packed = adt_def.repr().pack.is_some();
+            let (variant_infos, opt_discr_size) = variant_info_for_adt(cx, layout, adt_def);
+            record(adt_kind.into(), adt_packed, opt_discr_size, variant_infos);
+        }
+
+        ty::Generator(def_id, substs, _) => {
+            debug!("print-type-size t: `{:?}` record generator", layout.ty);
+            // Generators always have a begin/poisoned/end state with additional suspend points
+            let (variant_infos, opt_discr_size) =
+                variant_info_for_generator(cx, layout, def_id, substs);
+            record(DataTypeKind::Generator, false, opt_discr_size, variant_infos);
         }
 
         ty::Closure(..) => {
             debug!("print-type-size t: `{:?}` record closure", layout.ty);
             record(DataTypeKind::Closure, false, None, vec![]);
-            return;
         }
 
         _ => {
             debug!("print-type-size t: `{:?}` skip non-nominal", layout.ty);
-            return;
         }
     };
+}
 
-    let adt_kind = adt_def.adt_kind();
-    let adt_packed = adt_def.repr().pack.is_some();
-
+fn variant_info_for_adt<'tcx>(
+    cx: &LayoutCx<'tcx, TyCtxt<'tcx>>,
+    layout: TyAndLayout<'tcx>,
+    adt_def: AdtDef<'tcx>,
+) -> (Vec<VariantInfo>, Option<Size>) {
     let build_variant_info = |n: Option<Symbol>, flds: &[Symbol], layout: TyAndLayout<'tcx>| {
         let mut min_size = Size::ZERO;
         let field_info: Vec<_> = flds
@@ -843,10 +876,7 @@ fn record_layout_for_printing_outlined<'tcx>(
             .map(|(i, &name)| {
                 let field_layout = layout.field(cx, i);
                 let offset = layout.fields.offset(i);
-                let field_end = offset + field_layout.size;
-                if min_size < field_end {
-                    min_size = field_end;
-                }
+                min_size = min_size.max(offset + field_layout.size);
                 FieldInfo {
                     name,
                     offset: offset.bytes(),
@@ -871,16 +901,9 @@ fn record_layout_for_printing_outlined<'tcx>(
                 debug!("print-type-size `{:#?}` variant {}", layout, adt_def.variant(index).name);
                 let variant_def = &adt_def.variant(index);
                 let fields: Vec<_> = variant_def.fields.iter().map(|f| f.name).collect();
-                record(
-                    adt_kind.into(),
-                    adt_packed,
-                    None,
-                    vec![build_variant_info(Some(variant_def.name), &fields, layout)],
-                );
+                (vec![build_variant_info(Some(variant_def.name), &fields, layout)], None)
             } else {
-                // (This case arises for *empty* enums; so give it
-                // zero variants.)
-                record(adt_kind.into(), adt_packed, None, vec![]);
+                (vec![], None)
             }
         }
 
@@ -898,15 +921,117 @@ fn record_layout_for_printing_outlined<'tcx>(
                     build_variant_info(Some(variant_def.name), &fields, layout.for_variant(cx, i))
                 })
                 .collect();
-            record(
-                adt_kind.into(),
-                adt_packed,
+
+            (
+                variant_infos,
                 match tag_encoding {
                     TagEncoding::Direct => Some(tag.size(cx)),
                     _ => None,
                 },
-                variant_infos,
-            );
+            )
         }
     }
 }
+
+fn variant_info_for_generator<'tcx>(
+    cx: &LayoutCx<'tcx, TyCtxt<'tcx>>,
+    layout: TyAndLayout<'tcx>,
+    def_id: DefId,
+    substs: ty::SubstsRef<'tcx>,
+) -> (Vec<VariantInfo>, Option<Size>) {
+    let Variants::Multiple { tag, ref tag_encoding, tag_field, .. } = layout.variants else {
+        return (vec![], None);
+    };
+
+    let (generator, state_specific_names) = cx.tcx.generator_layout_and_saved_local_names(def_id);
+    let upvar_names = cx.tcx.closure_saved_names_of_captured_variables(def_id);
+
+    let mut upvars_size = Size::ZERO;
+    let upvar_fields: Vec<_> = substs
+        .as_generator()
+        .upvar_tys()
+        .zip(upvar_names)
+        .enumerate()
+        .map(|(field_idx, (_, name))| {
+            let field_layout = layout.field(cx, field_idx);
+            let offset = layout.fields.offset(field_idx);
+            upvars_size = upvars_size.max(offset + field_layout.size);
+            FieldInfo {
+                name: Symbol::intern(&name),
+                offset: offset.bytes(),
+                size: field_layout.size.bytes(),
+                align: field_layout.align.abi.bytes(),
+            }
+        })
+        .collect();
+
+    let variant_infos: Vec<_> = generator
+        .variant_fields
+        .iter_enumerated()
+        .map(|(variant_idx, variant_def)| {
+            let variant_layout = layout.for_variant(cx, variant_idx);
+            let mut variant_size = Size::ZERO;
+            let fields = variant_def
+                .iter()
+                .enumerate()
+                .map(|(field_idx, local)| {
+                    let field_layout = variant_layout.field(cx, field_idx);
+                    let offset = variant_layout.fields.offset(field_idx);
+                    // The struct is as large as the last field's end
+                    variant_size = variant_size.max(offset + field_layout.size);
+                    FieldInfo {
+                        name: state_specific_names.get(*local).copied().flatten().unwrap_or(
+                            Symbol::intern(&format!(".generator_field{}", local.as_usize())),
+                        ),
+                        offset: offset.bytes(),
+                        size: field_layout.size.bytes(),
+                        align: field_layout.align.abi.bytes(),
+                    }
+                })
+                .chain(upvar_fields.iter().copied())
+                .collect();
+
+            // If the variant has no state-specific fields, then it's the size of the upvars.
+            if variant_size == Size::ZERO {
+                variant_size = upvars_size;
+            }
+
+            // This `if` deserves some explanation.
+            //
+            // The layout code has a choice of where to place the discriminant of this generator.
+            // If the discriminant of the generator is placed early in the layout (before the
+            // variant's own fields), then it'll implicitly be counted towards the size of the
+            // variant, since we use the maximum offset to calculate size.
+            //    (side-note: I know this is a bit problematic given upvars placement, etc).
+            //
+            // This is important, since the layout printing code always subtracts this discriminant
+            // size from the variant size if the struct is "enum"-like, so failing to account for it
+            // will either lead to numerical underflow, or an underreported variant size...
+            //
+            // However, if the discriminant is placed past the end of the variant, then we need
+            // to factor in the size of the discriminant manually. This really should be refactored
+            // better, but this "works" for now.
+            if layout.fields.offset(tag_field) >= variant_size {
+                variant_size += match tag_encoding {
+                    TagEncoding::Direct => tag.size(cx),
+                    _ => Size::ZERO,
+                };
+            }
+
+            VariantInfo {
+                name: Some(Symbol::intern(&ty::GeneratorSubsts::variant_name(variant_idx))),
+                kind: SizeKind::Exact,
+                size: variant_size.bytes(),
+                align: variant_layout.align.abi.bytes(),
+                fields,
+            }
+        })
+        .collect();
+    (
+        variant_infos,
+        match tag_encoding {
+            TagEncoding::Direct => Some(tag.size(cx)),
+            _ => None,
+        },
+    )
+}
diff --git a/compiler/rustc_ty_utils/src/lib.rs b/compiler/rustc_ty_utils/src/lib.rs
index 7ad5cbc01..0853de601 100644
--- a/compiler/rustc_ty_utils/src/lib.rs
+++ b/compiler/rustc_ty_utils/src/lib.rs
@@ -6,7 +6,6 @@
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(let_chains)]
-#![feature(control_flow_enum)]
 #![feature(never_type)]
 #![feature(box_patterns)]
 #![recursion_limit = "256"]
diff --git a/compiler/rustc_ty_utils/src/needs_drop.rs b/compiler/rustc_ty_utils/src/needs_drop.rs
index 024dcd591..0df060fc5 100644
--- a/compiler/rustc_ty_utils/src/needs_drop.rs
+++ b/compiler/rustc_ty_utils/src/needs_drop.rs
@@ -152,7 +152,7 @@ where
                             queue_type(self, required);
                         }
                     }
-                    ty::Array(..) | ty::Opaque(..) | ty::Projection(..) | ty::Param(_) => {
+                    ty::Array(..) | ty::Alias(..) | ty::Param(_) => {
                         if ty == component {
                             // Return the type to the caller: they may be able
                             // to normalize further than we can.
diff --git a/compiler/rustc_ty_utils/src/ty.rs b/compiler/rustc_ty_utils/src/ty.rs
index 5fc9bcac1..eb5454bf2 100644
--- a/compiler/rustc_ty_utils/src/ty.rs
+++ b/compiler/rustc_ty_utils/src/ty.rs
@@ -2,6 +2,7 @@ use rustc_data_structures::fx::FxIndexSet;
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_middle::ty::{self, Binder, Predicate, PredicateKind, ToPredicate, Ty, TyCtxt};
+use rustc_session::config::TraitSolver;
 use rustc_trait_selection::traits;
 
 fn sized_constraint_for_ty<'tcx>(
@@ -37,7 +38,7 @@ fn sized_constraint_for_ty<'tcx>(
                 .collect()
         }
 
-        Projection(..) | Opaque(..) => {
+        Alias(..) => {
             // must calculate explicitly.
             // FIXME: consider special-casing always-Sized projections
             vec![ty]
@@ -121,7 +122,7 @@ fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ParamEnv<'_> {
     // are any errors at that point, so outside of type inference you can be
     // sure that this will succeed without errors anyway.
 
-    if tcx.sess.opts.unstable_opts.chalk {
+    if tcx.sess.opts.unstable_opts.trait_solver == TraitSolver::Chalk {
         let environment = well_formed_types_in_env(tcx, def_id);
         predicates.extend(environment);
     }
@@ -161,7 +162,7 @@ fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ParamEnv<'_> {
                 kind: hir::ImplItemKind::Type(..) | hir::ImplItemKind::Fn(..),
                 ..
             }) => {
-                let parent_hir_id = tcx.hir().get_parent_node(hir_id);
+                let parent_hir_id = tcx.hir().parent_id(hir_id);
                 match tcx.hir().get(parent_hir_id) {
                     hir::Node::Item(hir::Item {
                         kind: hir::ItemKind::Impl(hir::Impl { constness, .. }),
@@ -225,10 +226,7 @@ fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ParamEnv<'_> {
 /// that are assumed to be well-formed (because they come from the environment).
 ///
 /// Used only in chalk mode.
-fn well_formed_types_in_env<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    def_id: DefId,
-) -> &'tcx ty::List<Predicate<'tcx>> {
+fn well_formed_types_in_env(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::List<Predicate<'_>> {
     use rustc_hir::{ForeignItemKind, ImplItemKind, ItemKind, Node, TraitItemKind};
     use rustc_middle::ty::subst::GenericArgKind;
 
@@ -291,7 +289,7 @@ fn well_formed_types_in_env<'tcx>(
         // In a trait impl, we assume that the header trait ref and all its
         // constituents are well-formed.
         NodeKind::TraitImpl => {
-            let trait_ref = tcx.impl_trait_ref(def_id).expect("not an impl");
+            let trait_ref = tcx.impl_trait_ref(def_id).expect("not an impl").subst_identity();
 
             // FIXME(chalk): this has problems because of late-bound regions
             //inputs.extend(trait_ref.substs.iter().flat_map(|arg| arg.walk()));
@@ -362,7 +360,8 @@ fn issue33140_self_ty(tcx: TyCtxt<'_>, def_id: DefId) -> Option<Ty<'_>> {
 
     let trait_ref = tcx
         .impl_trait_ref(def_id)
-        .unwrap_or_else(|| bug!("issue33140_self_ty called on inherent impl {:?}", def_id));
+        .unwrap_or_else(|| bug!("issue33140_self_ty called on inherent impl {:?}", def_id))
+        .skip_binder();
 
     debug!("issue33140_self_ty({:?}), trait-ref={:?}", def_id, trait_ref);