diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 439c728798d3a..46a3c0fa10152 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -408,7 +408,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     let param = generics.type_param(&param_ty, tcx);
                     if let Some(generics) = tcx
                         .hir()
-                        .get_generics(tcx.closure_base_def_id(self.mir_def_id().to_def_id()))
+                        .get_generics(tcx.typeck_root_def_id(self.mir_def_id().to_def_id()))
                     {
                         suggest_constraining_type_param(
                             tcx,
diff --git a/compiler/rustc_borrowck/src/nll.rs b/compiler/rustc_borrowck/src/nll.rs
index e5924f9d08478..6ffab16577908 100644
--- a/compiler/rustc_borrowck/src/nll.rs
+++ b/compiler/rustc_borrowck/src/nll.rs
@@ -376,7 +376,7 @@ pub(super) fn dump_annotation<'a, 'tcx>(
     errors_buffer: &mut Vec<Diagnostic>,
 ) {
     let tcx = infcx.tcx;
-    let base_def_id = tcx.closure_base_def_id(body.source.def_id());
+    let base_def_id = tcx.typeck_root_def_id(body.source.def_id());
     if !tcx.has_attr(base_def_id, sym::rustc_regions) {
         return;
     }
diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs
index f4a5da1fe36fa..b39a28f79aadd 100644
--- a/compiler/rustc_borrowck/src/region_infer/mod.rs
+++ b/compiler/rustc_borrowck/src/region_infer/mod.rs
@@ -569,7 +569,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         // to store those. Otherwise, we'll pass in `None` to the
         // functions below, which will trigger them to report errors
         // eagerly.
-        let mut outlives_requirements = infcx.tcx.is_closure(mir_def_id).then(Vec::new);
+        let mut outlives_requirements = infcx.tcx.is_typeck_child(mir_def_id).then(Vec::new);
 
         self.check_type_tests(infcx, body, outlives_requirements.as_mut(), &mut errors_buffer);
 
@@ -2229,7 +2229,7 @@ impl<'tcx> ClosureRegionRequirementsExt<'tcx> for ClosureRegionRequirements<'tcx
             tcx,
             closure_substs,
             self.num_external_vids,
-            tcx.closure_base_def_id(closure_def_id),
+            tcx.typeck_root_def_id(closure_def_id),
         );
         debug!("apply_requirements: closure_mapping={:?}", closure_mapping);
 
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index 06e34bdce3f86..ddd077c22faf8 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -10,6 +10,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::vec_map::VecMap;
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
+use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::lang_items::LangItem;
 use rustc_index::vec::{Idx, IndexVec};
@@ -1343,13 +1344,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 // though.
                 let category = match place.as_local() {
                     Some(RETURN_PLACE) => {
-                        if let BorrowCheckContext {
-                            universal_regions:
-                                UniversalRegions { defining_ty: DefiningTy::Const(def_id, _), .. },
-                            ..
-                        } = self.borrowck_context
-                        {
-                            if tcx.is_static(*def_id) {
+                        let defining_ty = &self.borrowck_context.universal_regions.defining_ty;
+                        if defining_ty.is_const() {
+                            if tcx.is_static(defining_ty.def_id()) {
                                 ConstraintCategory::UseAsStatic
                             } else {
                                 ConstraintCategory::UseAsConst
@@ -1527,6 +1524,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 }
             }
             TerminatorKind::SwitchInt { ref discr, switch_ty, .. } => {
+                self.check_operand(discr, term_location);
+
                 let discr_ty = discr.ty(body, tcx);
                 if let Err(terr) = self.sub_types(
                     discr_ty,
@@ -1549,6 +1548,11 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 // FIXME: check the values
             }
             TerminatorKind::Call { ref func, ref args, ref destination, from_hir_call, .. } => {
+                self.check_operand(func, term_location);
+                for arg in args {
+                    self.check_operand(arg, term_location);
+                }
+
                 let func_ty = func.ty(body, tcx);
                 debug!("check_terminator: call, func_ty={:?}", func_ty);
                 let sig = match func_ty.kind() {
@@ -1593,6 +1597,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 self.check_call_inputs(body, term, &sig, args, term_location, from_hir_call);
             }
             TerminatorKind::Assert { ref cond, ref msg, .. } => {
+                self.check_operand(cond, term_location);
+
                 let cond_ty = cond.ty(body, tcx);
                 if cond_ty != tcx.types.bool {
                     span_mirbug!(self, term, "bad Assert ({:?}, not bool", cond_ty);
@@ -1608,6 +1614,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 }
             }
             TerminatorKind::Yield { ref value, .. } => {
+                self.check_operand(value, term_location);
+
                 let value_ty = value.ty(body, tcx);
                 match body.yield_ty() {
                     None => span_mirbug!(self, term, "yield in non-generator"),
@@ -1650,7 +1658,12 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                     Some(RETURN_PLACE) => {
                         if let BorrowCheckContext {
                             universal_regions:
-                                UniversalRegions { defining_ty: DefiningTy::Const(def_id, _), .. },
+                                UniversalRegions {
+                                    defining_ty:
+                                        DefiningTy::Const(def_id, _)
+                                        | DefiningTy::InlineConst(def_id, _),
+                                    ..
+                                },
                             ..
                         } = self.borrowck_context
                         {
@@ -1931,15 +1944,51 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         }
     }
 
+    fn check_operand(&mut self, op: &Operand<'tcx>, location: Location) {
+        if let Operand::Constant(constant) = op {
+            let maybe_uneval = match constant.literal {
+                ConstantKind::Ty(ct) => match ct.val {
+                    ty::ConstKind::Unevaluated(uv) => Some(uv),
+                    _ => None,
+                },
+                _ => None,
+            };
+            if let Some(uv) = maybe_uneval {
+                if uv.promoted.is_none() {
+                    let tcx = self.tcx();
+                    let def_id = uv.def.def_id_for_type_of();
+                    if tcx.def_kind(def_id) == DefKind::InlineConst {
+                        let predicates = self.prove_closure_bounds(
+                            tcx,
+                            def_id.expect_local(),
+                            uv.substs(tcx),
+                            location,
+                        );
+                        self.normalize_and_prove_instantiated_predicates(
+                            def_id,
+                            predicates,
+                            location.to_locations(),
+                        );
+                    }
+                }
+            }
+        }
+    }
+
     fn check_rvalue(&mut self, body: &Body<'tcx>, rvalue: &Rvalue<'tcx>, location: Location) {
         let tcx = self.tcx();
 
         match rvalue {
             Rvalue::Aggregate(ak, ops) => {
+                for op in ops {
+                    self.check_operand(op, location);
+                }
                 self.check_aggregate_rvalue(&body, rvalue, ak, ops, location)
             }
 
             Rvalue::Repeat(operand, len) => {
+                self.check_operand(operand, location);
+
                 // If the length cannot be evaluated we must assume that the length can be larger
                 // than 1.
                 // If the length is larger than 1, the repeat expression will need to copy the
@@ -1990,7 +2039,22 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 }
             }
 
-            Rvalue::NullaryOp(_, ty) | Rvalue::ShallowInitBox(_, ty) => {
+            Rvalue::NullaryOp(_, ty) => {
+                let trait_ref = ty::TraitRef {
+                    def_id: tcx.require_lang_item(LangItem::Sized, Some(self.last_span)),
+                    substs: tcx.mk_substs_trait(ty, &[]),
+                };
+
+                self.prove_trait_ref(
+                    trait_ref,
+                    location.to_locations(),
+                    ConstraintCategory::SizedBound,
+                );
+            }
+
+            Rvalue::ShallowInitBox(operand, ty) => {
+                self.check_operand(operand, location);
+
                 let trait_ref = ty::TraitRef {
                     def_id: tcx.require_lang_item(LangItem::Sized, Some(self.last_span)),
                     substs: tcx.mk_substs_trait(ty, &[]),
@@ -2004,6 +2068,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             }
 
             Rvalue::Cast(cast_kind, op, ty) => {
+                self.check_operand(op, location);
+
                 match cast_kind {
                     CastKind::Pointer(PointerCast::ReifyFnPointer) => {
                         let fn_sig = op.ty(body, tcx).fn_sig(tcx);
@@ -2250,6 +2316,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 BinOp::Eq | BinOp::Ne | BinOp::Lt | BinOp::Le | BinOp::Gt | BinOp::Ge,
                 box (left, right),
             ) => {
+                self.check_operand(left, location);
+                self.check_operand(right, location);
+
                 let ty_left = left.ty(body, tcx);
                 match ty_left.kind() {
                     // Types with regions are comparable if they have a common super-type.
@@ -2300,13 +2369,19 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 }
             }
 
+            Rvalue::Use(operand) | Rvalue::UnaryOp(_, operand) => {
+                self.check_operand(operand, location);
+            }
+
+            Rvalue::BinaryOp(_, box (left, right))
+            | Rvalue::CheckedBinaryOp(_, box (left, right)) => {
+                self.check_operand(left, location);
+                self.check_operand(right, location);
+            }
+
             Rvalue::AddressOf(..)
             | Rvalue::ThreadLocalRef(..)
-            | Rvalue::Use(..)
             | Rvalue::Len(..)
-            | Rvalue::BinaryOp(..)
-            | Rvalue::CheckedBinaryOp(..)
-            | Rvalue::UnaryOp(..)
             | Rvalue::Discriminant(..) => {}
         }
     }
diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs
index 147e2aead648d..b986df403f9f3 100644
--- a/compiler/rustc_borrowck/src/universal_regions.rs
+++ b/compiler/rustc_borrowck/src/universal_regions.rs
@@ -23,7 +23,7 @@ use rustc_index::vec::{Idx, IndexVec};
 use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin};
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::subst::{InternalSubsts, Subst, SubstsRef};
-use rustc_middle::ty::{self, RegionVid, Ty, TyCtxt};
+use rustc_middle::ty::{self, InlineConstSubsts, InlineConstSubstsParts, RegionVid, Ty, TyCtxt};
 use std::iter;
 
 use crate::nll::ToRegionVid;
@@ -108,6 +108,10 @@ pub enum DefiningTy<'tcx> {
     /// is that it has no inputs and a single return value, which is
     /// the value of the constant.
     Const(DefId, SubstsRef<'tcx>),
+
+    /// The MIR represents an inline const. The signature has no inputs and a
+    /// single return value found via `InlineConstSubsts::ty`.
+    InlineConst(DefId, SubstsRef<'tcx>),
 }
 
 impl<'tcx> DefiningTy<'tcx> {
@@ -121,7 +125,7 @@ impl<'tcx> DefiningTy<'tcx> {
             DefiningTy::Generator(_, substs, _) => {
                 Either::Right(Either::Left(substs.as_generator().upvar_tys()))
             }
-            DefiningTy::FnDef(..) | DefiningTy::Const(..) => {
+            DefiningTy::FnDef(..) | DefiningTy::Const(..) | DefiningTy::InlineConst(..) => {
                 Either::Right(Either::Right(iter::empty()))
             }
         }
@@ -133,7 +137,7 @@ impl<'tcx> DefiningTy<'tcx> {
     pub fn implicit_inputs(self) -> usize {
         match self {
             DefiningTy::Closure(..) | DefiningTy::Generator(..) => 1,
-            DefiningTy::FnDef(..) | DefiningTy::Const(..) => 0,
+            DefiningTy::FnDef(..) | DefiningTy::Const(..) | DefiningTy::InlineConst(..) => 0,
         }
     }
 
@@ -142,7 +146,7 @@ impl<'tcx> DefiningTy<'tcx> {
     }
 
     pub fn is_const(&self) -> bool {
-        matches!(*self, DefiningTy::Const(..))
+        matches!(*self, DefiningTy::Const(..) | DefiningTy::InlineConst(..))
     }
 
     pub fn def_id(&self) -> DefId {
@@ -150,7 +154,8 @@ impl<'tcx> DefiningTy<'tcx> {
             DefiningTy::Closure(def_id, ..)
             | DefiningTy::Generator(def_id, ..)
             | DefiningTy::FnDef(def_id, ..)
-            | DefiningTy::Const(def_id, ..) => def_id,
+            | DefiningTy::Const(def_id, ..)
+            | DefiningTy::InlineConst(def_id, ..) => def_id,
         }
     }
 }
@@ -242,7 +247,7 @@ impl<'tcx> UniversalRegions<'tcx> {
         tcx: TyCtxt<'tcx>,
         closure_substs: SubstsRef<'tcx>,
         expected_num_vars: usize,
-        closure_base_def_id: DefId,
+        typeck_root_def_id: DefId,
     ) -> IndexVec<RegionVid, ty::Region<'tcx>> {
         let mut region_mapping = IndexVec::with_capacity(expected_num_vars);
         region_mapping.push(tcx.lifetimes.re_static);
@@ -250,7 +255,7 @@ impl<'tcx> UniversalRegions<'tcx> {
             region_mapping.push(fr);
         });
 
-        for_each_late_bound_region_defined_on(tcx, closure_base_def_id, |r| {
+        for_each_late_bound_region_defined_on(tcx, typeck_root_def_id, |r| {
             region_mapping.push(r);
         });
 
@@ -344,8 +349,8 @@ impl<'tcx> UniversalRegions<'tcx> {
                 // tests, and the resulting print-outs include def-ids
                 // and other things that are not stable across tests!
                 // So we just include the region-vid. Annoying.
-                let closure_base_def_id = tcx.closure_base_def_id(def_id);
-                for_each_late_bound_region_defined_on(tcx, closure_base_def_id, |r| {
+                let typeck_root_def_id = tcx.typeck_root_def_id(def_id);
+                for_each_late_bound_region_defined_on(tcx, typeck_root_def_id, |r| {
                     err.note(&format!("late-bound region is {:?}", self.to_region_vid(r),));
                 });
             }
@@ -359,8 +364,8 @@ impl<'tcx> UniversalRegions<'tcx> {
                 // FIXME: As above, we'd like to print out the region
                 // `r` but doing so is not stable across architectures
                 // and so forth.
-                let closure_base_def_id = tcx.closure_base_def_id(def_id);
-                for_each_late_bound_region_defined_on(tcx, closure_base_def_id, |r| {
+                let typeck_root_def_id = tcx.typeck_root_def_id(def_id);
+                for_each_late_bound_region_defined_on(tcx, typeck_root_def_id, |r| {
                     err.note(&format!("late-bound region is {:?}", self.to_region_vid(r),));
                 });
             }
@@ -376,6 +381,12 @@ impl<'tcx> UniversalRegions<'tcx> {
                     tcx.def_path_str_with_substs(def_id, substs),
                 ));
             }
+            DefiningTy::InlineConst(def_id, substs) => {
+                err.note(&format!(
+                    "defining inline constant type: {}",
+                    tcx.def_path_str_with_substs(def_id, substs),
+                ));
+            }
         }
     }
 }
@@ -411,7 +422,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
         let mut indices = self.compute_indices(fr_static, defining_ty);
         debug!("build: indices={:?}", indices);
 
-        let closure_base_def_id = self.infcx.tcx.closure_base_def_id(self.mir_def.did.to_def_id());
+        let typeck_root_def_id = self.infcx.tcx.typeck_root_def_id(self.mir_def.did.to_def_id());
 
         // If this is a closure or generator, then the late-bound regions from the enclosing
         // function are actually external regions to us. For example, here, 'a is not local
@@ -419,7 +430,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
         // fn foo<'a>() {
         //     let c = || { let x: &'a u32 = ...; }
         // }
-        if self.mir_def.did.to_def_id() != closure_base_def_id {
+        if self.mir_def.did.to_def_id() != typeck_root_def_id {
             self.infcx
                 .replace_late_bound_regions_with_nll_infer_vars(self.mir_def.did, &mut indices)
         }
@@ -437,7 +448,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
         );
         // Converse of above, if this is a function then the late-bound regions declared on its
         // signature are local to the fn.
-        if self.mir_def.did.to_def_id() == closure_base_def_id {
+        if self.mir_def.did.to_def_id() == typeck_root_def_id {
             self.infcx
                 .replace_late_bound_regions_with_nll_infer_vars(self.mir_def.did, &mut indices);
         }
@@ -502,12 +513,12 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
     /// see `DefiningTy` for details.
     fn defining_ty(&self) -> DefiningTy<'tcx> {
         let tcx = self.infcx.tcx;
-        let closure_base_def_id = tcx.closure_base_def_id(self.mir_def.did.to_def_id());
+        let typeck_root_def_id = tcx.typeck_root_def_id(self.mir_def.did.to_def_id());
 
         match tcx.hir().body_owner_kind(self.mir_hir_id) {
             BodyOwnerKind::Closure | BodyOwnerKind::Fn => {
-                let defining_ty = if self.mir_def.did.to_def_id() == closure_base_def_id {
-                    tcx.type_of(closure_base_def_id)
+                let defining_ty = if self.mir_def.did.to_def_id() == typeck_root_def_id {
+                    tcx.type_of(typeck_root_def_id)
                 } else {
                     let tables = tcx.typeck(self.mir_def.did);
                     tables.node_type(self.mir_hir_id)
@@ -534,11 +545,21 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
             }
 
             BodyOwnerKind::Const | BodyOwnerKind::Static(..) => {
-                assert_eq!(self.mir_def.did.to_def_id(), closure_base_def_id);
-                let identity_substs = InternalSubsts::identity_for_item(tcx, closure_base_def_id);
-                let substs =
-                    self.infcx.replace_free_regions_with_nll_infer_vars(FR, identity_substs);
-                DefiningTy::Const(self.mir_def.did.to_def_id(), substs)
+                let identity_substs = InternalSubsts::identity_for_item(tcx, typeck_root_def_id);
+                if self.mir_def.did.to_def_id() == typeck_root_def_id {
+                    let substs =
+                        self.infcx.replace_free_regions_with_nll_infer_vars(FR, identity_substs);
+                    DefiningTy::Const(self.mir_def.did.to_def_id(), substs)
+                } else {
+                    let ty = tcx.typeck(self.mir_def.did).node_type(self.mir_hir_id);
+                    let substs = InlineConstSubsts::new(
+                        tcx,
+                        InlineConstSubstsParts { parent_substs: identity_substs, ty },
+                    )
+                    .substs;
+                    let substs = self.infcx.replace_free_regions_with_nll_infer_vars(FR, substs);
+                    DefiningTy::InlineConst(self.mir_def.did.to_def_id(), substs)
+                }
             }
         }
     }
@@ -553,17 +574,19 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
         defining_ty: DefiningTy<'tcx>,
     ) -> UniversalRegionIndices<'tcx> {
         let tcx = self.infcx.tcx;
-        let closure_base_def_id = tcx.closure_base_def_id(self.mir_def.did.to_def_id());
-        let identity_substs = InternalSubsts::identity_for_item(tcx, closure_base_def_id);
+        let typeck_root_def_id = tcx.typeck_root_def_id(self.mir_def.did.to_def_id());
+        let identity_substs = InternalSubsts::identity_for_item(tcx, typeck_root_def_id);
         let fr_substs = match defining_ty {
-            DefiningTy::Closure(_, ref substs) | DefiningTy::Generator(_, ref substs, _) => {
+            DefiningTy::Closure(_, ref substs)
+            | DefiningTy::Generator(_, ref substs, _)
+            | DefiningTy::InlineConst(_, ref substs) => {
                 // In the case of closures, we rely on the fact that
                 // the first N elements in the ClosureSubsts are
-                // inherited from the `closure_base_def_id`.
+                // inherited from the `typeck_root_def_id`.
                 // Therefore, when we zip together (below) with
                 // `identity_substs`, we will get only those regions
                 // that correspond to early-bound regions declared on
-                // the `closure_base_def_id`.
+                // the `typeck_root_def_id`.
                 assert!(substs.len() >= identity_substs.len());
                 assert_eq!(substs.regions().count(), identity_substs.regions().count());
                 substs
@@ -648,6 +671,12 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
                 let ty = indices.fold_to_region_vids(tcx, ty);
                 ty::Binder::dummy(tcx.intern_type_list(&[ty]))
             }
+
+            DefiningTy::InlineConst(def_id, substs) => {
+                assert_eq!(self.mir_def.did.to_def_id(), def_id);
+                let ty = substs.as_inline_const().ty();
+                ty::Binder::dummy(tcx.intern_type_list(&[ty]))
+            }
         }
     }
 }
@@ -736,8 +765,8 @@ impl<'cx, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'cx, 'tcx> {
         indices: &mut UniversalRegionIndices<'tcx>,
     ) {
         debug!("replace_late_bound_regions_with_nll_infer_vars(mir_def_id={:?})", mir_def_id);
-        let closure_base_def_id = self.tcx.closure_base_def_id(mir_def_id.to_def_id());
-        for_each_late_bound_region_defined_on(self.tcx, closure_base_def_id, |r| {
+        let typeck_root_def_id = self.tcx.typeck_root_def_id(mir_def_id.to_def_id());
+        for_each_late_bound_region_defined_on(self.tcx, typeck_root_def_id, |r| {
             debug!("replace_late_bound_regions_with_nll_infer_vars: r={:?}", r);
             if !indices.indices.contains_key(&r) {
                 let region_vid = self.next_nll_region_var(FR);
diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs
index 6187dbf4d1b55..3d05fc15b38f4 100644
--- a/compiler/rustc_codegen_llvm/src/back/write.rs
+++ b/compiler/rustc_codegen_llvm/src/back/write.rs
@@ -17,6 +17,7 @@ use rustc_codegen_ssa::back::write::{
 };
 use rustc_codegen_ssa::traits::*;
 use rustc_codegen_ssa::{CompiledModule, ModuleCodegen};
+use rustc_data_structures::profiling::SelfProfilerRef;
 use rustc_data_structures::small_c_str::SmallCStr;
 use rustc_errors::{FatalError, Handler, Level};
 use rustc_fs_util::{link_or_copy, path_to_c_string};
@@ -53,6 +54,7 @@ pub fn write_output_file(
     output: &Path,
     dwo_output: Option<&Path>,
     file_type: llvm::FileType,
+    self_profiler_ref: &SelfProfilerRef,
 ) -> Result<(), FatalError> {
     unsafe {
         let output_c = path_to_c_string(output);
@@ -76,6 +78,19 @@ pub fn write_output_file(
                 file_type,
             )
         };
+
+        // Record artifact sizes for self-profiling
+        if result == llvm::LLVMRustResult::Success {
+            let artifact_kind = match file_type {
+                llvm::FileType::ObjectFile => "object_file",
+                llvm::FileType::AssemblyFile => "assembly_file",
+            };
+            record_artifact_size(self_profiler_ref, artifact_kind, output);
+            if let Some(dwo_file) = dwo_output {
+                record_artifact_size(self_profiler_ref, "dwo_file", dwo_file);
+            }
+        }
+
         result.into_result().map_err(|()| {
             let msg = format!("could not write output to {}", output.display());
             llvm_err(handler, &msg)
@@ -752,6 +767,14 @@ pub(crate) unsafe fn codegen(
             let thin = ThinBuffer::new(llmod);
             let data = thin.data();
 
+            if let Some(bitcode_filename) = bc_out.file_name() {
+                cgcx.prof.artifact_size(
+                    "llvm_bitcode",
+                    bitcode_filename.to_string_lossy(),
+                    data.len() as u64,
+                );
+            }
+
             if config.emit_bc || config.emit_obj == EmitObj::Bitcode {
                 let _timer = cgcx.prof.generic_activity_with_arg(
                     "LLVM_module_codegen_emit_bitcode",
@@ -812,6 +835,11 @@ pub(crate) unsafe fn codegen(
             }
 
             let result = llvm::LLVMRustPrintModule(llmod, out_c.as_ptr(), demangle_callback);
+
+            if result == llvm::LLVMRustResult::Success {
+                record_artifact_size(&cgcx.prof, "llvm_ir", &out);
+            }
+
             result.into_result().map_err(|()| {
                 let msg = format!("failed to write LLVM IR to {}", out.display());
                 llvm_err(diag_handler, &msg)
@@ -842,6 +870,7 @@ pub(crate) unsafe fn codegen(
                     &path,
                     None,
                     llvm::FileType::AssemblyFile,
+                    &cgcx.prof,
                 )
             })?;
         }
@@ -875,6 +904,7 @@ pub(crate) unsafe fn codegen(
                         &obj_out,
                         dwo_out,
                         llvm::FileType::ObjectFile,
+                        &cgcx.prof,
                     )
                 })?;
             }
@@ -1131,3 +1161,19 @@ fn create_msvc_imps(
         symbol_name.starts_with(b"__llvm_profile_")
     }
 }
+
+fn record_artifact_size(
+    self_profiler_ref: &SelfProfilerRef,
+    artifact_kind: &'static str,
+    path: &Path,
+) {
+    // Don't stat the file if we are not going to record its size.
+    if !self_profiler_ref.enabled() {
+        return;
+    }
+
+    if let Some(artifact_name) = path.file_name() {
+        let file_size = std::fs::metadata(path).map(|m| m.len()).unwrap_or(0);
+        self_profiler_ref.artifact_size(artifact_kind, artifact_name.to_string_lossy(), file_size);
+    }
+}
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
index 1f1bd73c7d035..2a6bf7d9b1a4d 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
@@ -322,7 +322,7 @@ impl DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         type_names::push_item_name(self.tcx(), def_id, false, &mut name);
 
         // Find the enclosing function, in case this is a closure.
-        let enclosing_fn_def_id = self.tcx().closure_base_def_id(def_id);
+        let enclosing_fn_def_id = self.tcx().typeck_root_def_id(def_id);
 
         // Get_template_parameters() will append a `<...>` clause to the function
         // name if necessary.
diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index 6c02543bd7cc4..1ba0c4fa05b5b 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -121,6 +121,19 @@ pub fn link_binary<'a, B: ArchiveBuilder<'a>>(
             if sess.opts.json_artifact_notifications {
                 sess.parse_sess.span_diagnostic.emit_artifact_notification(&out_filename, "link");
             }
+
+            if sess.prof.enabled() {
+                if let Some(artifact_name) = out_filename.file_name() {
+                    // Record size for self-profiling
+                    let file_size = std::fs::metadata(&out_filename).map(|m| m.len()).unwrap_or(0);
+
+                    sess.prof.artifact_size(
+                        "linked_artifact",
+                        artifact_name.to_string_lossy(),
+                        file_size,
+                    );
+                }
+            }
         }
     }
 
diff --git a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
index 57af0ff071433..6d3a89c0a8a5b 100644
--- a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
+++ b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
@@ -42,6 +42,7 @@ fn eval_body_using_ecx<'mir, 'tcx>(
                     | DefKind::Static
                     | DefKind::ConstParam
                     | DefKind::AnonConst
+                    | DefKind::InlineConst
                     | DefKind::AssocConst
             ),
         "Unexpected DefKind: {:?}",
diff --git a/compiler/rustc_hir/src/def.rs b/compiler/rustc_hir/src/def.rs
index cb668eb35e093..60761a05de827 100644
--- a/compiler/rustc_hir/src/def.rs
+++ b/compiler/rustc_hir/src/def.rs
@@ -104,8 +104,10 @@ pub enum DefKind {
     Use,
     /// An `extern` block.
     ForeignMod,
-    /// Anonymous constant, e.g. the `1 + 2` in `[u8; 1 + 2]`, or `const { 1 + 2}`
+    /// Anonymous constant, e.g. the `1 + 2` in `[u8; 1 + 2]`
     AnonConst,
+    /// An inline constant, e.g. `const { 1 + 2 }`
+    InlineConst,
     /// Opaque type, aka `impl Trait`.
     OpaqueTy,
     Field,
@@ -155,6 +157,7 @@ impl DefKind {
             DefKind::Use => "import",
             DefKind::ForeignMod => "foreign module",
             DefKind::AnonConst => "constant expression",
+            DefKind::InlineConst => "inline constant",
             DefKind::Field => "field",
             DefKind::Impl => "implementation",
             DefKind::Closure => "closure",
@@ -174,6 +177,7 @@ impl DefKind {
             | DefKind::OpaqueTy
             | DefKind::Impl
             | DefKind::Use
+            | DefKind::InlineConst
             | DefKind::ExternCrate => "an",
             DefKind::Macro(macro_kind) => macro_kind.article(),
             _ => "a",
@@ -207,6 +211,7 @@ impl DefKind {
 
             // Not namespaced.
             DefKind::AnonConst
+            | DefKind::InlineConst
             | DefKind::Field
             | DefKind::LifetimeParam
             | DefKind::ExternCrate
diff --git a/compiler/rustc_infer/src/infer/outlives/env.rs b/compiler/rustc_infer/src/infer/outlives/env.rs
index 9e04773c5fa20..3947282aa6217 100644
--- a/compiler/rustc_infer/src/infer/outlives/env.rs
+++ b/compiler/rustc_infer/src/infer/outlives/env.rs
@@ -99,7 +99,7 @@ impl<'a, 'tcx> OutlivesEnvironment<'tcx> {
     /// function. We can then add implied bounds and the like from the
     /// closure arguments into the environment -- these should only
     /// apply in the closure body, so once we exit, we invoke
-    /// `pop_snapshot_post_closure` to remove them.
+    /// `pop_snapshot_post_typeck_child` to remove them.
     ///
     /// Example:
     ///
@@ -129,12 +129,12 @@ impl<'a, 'tcx> OutlivesEnvironment<'tcx> {
     /// seems like it'd be readily fixed if we wanted. There are
     /// similar leaks around givens that seem equally suspicious, to
     /// be honest. --nmatsakis
-    pub fn push_snapshot_pre_closure(&self) -> usize {
+    pub fn push_snapshot_pre_typeck_child(&self) -> usize {
         self.region_bound_pairs_accum.len()
     }
 
-    /// See `push_snapshot_pre_closure`.
-    pub fn pop_snapshot_post_closure(&mut self, len: usize) {
+    /// See `push_snapshot_pre_typeck_child`.
+    pub fn pop_snapshot_post_typeck_child(&mut self, len: usize) {
         self.region_bound_pairs_accum.truncate(len);
     }
 
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 0dbef66ac37d7..d46829c2ceea6 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -797,6 +797,7 @@ fn should_encode_visibility(def_kind: DefKind) -> bool {
         | DefKind::ConstParam
         | DefKind::LifetimeParam
         | DefKind::AnonConst
+        | DefKind::InlineConst
         | DefKind::GlobalAsm
         | DefKind::Closure
         | DefKind::Generator
@@ -832,6 +833,7 @@ fn should_encode_stability(def_kind: DefKind) -> bool {
         DefKind::Use
         | DefKind::LifetimeParam
         | DefKind::AnonConst
+        | DefKind::InlineConst
         | DefKind::GlobalAsm
         | DefKind::Closure
         | DefKind::Generator
@@ -856,9 +858,11 @@ fn should_encode_mir(tcx: TyCtxt<'_>, def_id: LocalDefId) -> (bool, bool) {
             (true, mir_opt_base)
         }
         // Constants
-        DefKind::AnonConst | DefKind::AssocConst | DefKind::Static | DefKind::Const => {
-            (true, false)
-        }
+        DefKind::AnonConst
+        | DefKind::InlineConst
+        | DefKind::AssocConst
+        | DefKind::Static
+        | DefKind::Const => (true, false),
         // Full-fledged functions
         DefKind::AssocFn | DefKind::Fn => {
             let generics = tcx.generics_of(def_id);
@@ -914,6 +918,7 @@ fn should_encode_variances(def_kind: DefKind) -> bool {
         | DefKind::Use
         | DefKind::LifetimeParam
         | DefKind::AnonConst
+        | DefKind::InlineConst
         | DefKind::GlobalAsm
         | DefKind::Closure
         | DefKind::Generator
@@ -939,6 +944,7 @@ fn should_encode_generics(def_kind: DefKind) -> bool {
         | DefKind::AssocFn
         | DefKind::AssocConst
         | DefKind::AnonConst
+        | DefKind::InlineConst
         | DefKind::OpaqueTy
         | DefKind::Impl
         | DefKind::Field
@@ -2187,5 +2193,8 @@ fn encode_metadata_impl(tcx: TyCtxt<'_>) -> EncodedMetadata {
     result[header + 2] = (pos >> 8) as u8;
     result[header + 3] = (pos >> 0) as u8;
 
+    // Record metadata size for self-profiling
+    tcx.prof.artifact_size("crate_metadata", "crate_metadata", result.len() as u64);
+
     EncodedMetadata { raw_data: result }
 }
diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs
index 8f52e16c2ebe4..d9d0781b37aac 100644
--- a/compiler/rustc_middle/src/hir/map/mod.rs
+++ b/compiler/rustc_middle/src/hir/map/mod.rs
@@ -266,7 +266,15 @@ impl<'hir> Map<'hir> {
                 };
                 DefKind::Ctor(ctor_of, def::CtorKind::from_hir(variant_data))
             }
-            Node::AnonConst(_) => DefKind::AnonConst,
+            Node::AnonConst(_) => {
+                let inline = match self.find(self.get_parent_node(hir_id)) {
+                    Some(Node::Expr(&Expr {
+                        kind: ExprKind::ConstBlock(ref anon_const), ..
+                    })) if anon_const.hir_id == hir_id => true,
+                    _ => false,
+                };
+                if inline { DefKind::InlineConst } else { DefKind::AnonConst }
+            }
             Node::Field(_) => DefKind::Field,
             Node::Expr(expr) => match expr.kind {
                 ExprKind::Closure(.., None) => DefKind::Closure,
diff --git a/compiler/rustc_middle/src/mir/pretty.rs b/compiler/rustc_middle/src/mir/pretty.rs
index 8e363cfbff562..8e1b887f87da7 100644
--- a/compiler/rustc_middle/src/mir/pretty.rs
+++ b/compiler/rustc_middle/src/mir/pretty.rs
@@ -958,7 +958,7 @@ fn write_mir_sig(tcx: TyCtxt<'_>, body: &Body<'_>, w: &mut dyn Write) -> io::Res
             write!(w, "static {}", if tcx.is_mutable_static(def_id) { "mut " } else { "" })?
         }
         (_, _) if is_function => write!(w, "fn ")?,
-        (DefKind::AnonConst, _) => {} // things like anon const, not an item
+        (DefKind::AnonConst | DefKind::InlineConst, _) => {} // things like anon const, not an item
         _ => bug!("Unexpected def kind {:?}", kind),
     }
 
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 06041bbb02d35..a9f94b74c5efb 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -797,7 +797,7 @@ rustc_queries! {
     /// additional requirements that the closure's creator must verify.
     query mir_borrowck(key: LocalDefId) -> &'tcx mir::BorrowCheckResult<'tcx> {
         desc { |tcx| "borrow-checking `{}`", tcx.def_path_str(key.to_def_id()) }
-        cache_on_disk_if(tcx) { tcx.is_closure(key.to_def_id()) }
+        cache_on_disk_if(tcx) { tcx.is_typeck_child(key.to_def_id()) }
     }
     query mir_borrowck_const_arg(key: (LocalDefId, DefId)) -> &'tcx mir::BorrowCheckResult<'tcx> {
         desc {
diff --git a/compiler/rustc_middle/src/ty/consts.rs b/compiler/rustc_middle/src/ty/consts.rs
index 869b2ab9dbcbc..27e22ccac02a7 100644
--- a/compiler/rustc_middle/src/ty/consts.rs
+++ b/compiler/rustc_middle/src/ty/consts.rs
@@ -1,7 +1,9 @@
 use crate::mir::interpret::ConstValue;
 use crate::mir::interpret::{LitToConstInput, Scalar};
-use crate::ty::{self, Ty, TyCtxt};
-use crate::ty::{ParamEnv, ParamEnvAnd};
+use crate::ty::{
+    self, InlineConstSubsts, InlineConstSubstsParts, InternalSubsts, ParamEnv, ParamEnvAnd, Ty,
+    TyCtxt, TypeFoldable,
+};
 use rustc_errors::ErrorReported;
 use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, LocalDefId};
@@ -54,6 +56,24 @@ impl<'tcx> Const<'tcx> {
 
         let ty = tcx.type_of(def.def_id_for_type_of());
 
+        match Self::try_eval_lit_or_param(tcx, ty, expr) {
+            Some(v) => v,
+            None => tcx.mk_const(ty::Const {
+                val: ty::ConstKind::Unevaluated(ty::Unevaluated {
+                    def: def.to_global(),
+                    substs_: None,
+                    promoted: None,
+                }),
+                ty,
+            }),
+        }
+    }
+
+    fn try_eval_lit_or_param(
+        tcx: TyCtxt<'tcx>,
+        ty: Ty<'tcx>,
+        expr: &'tcx hir::Expr<'tcx>,
+    ) -> Option<&'tcx Self> {
         let lit_input = match expr.kind {
             hir::ExprKind::Lit(ref lit) => Some(LitToConstInput { lit: &lit.node, ty, neg: false }),
             hir::ExprKind::Unary(hir::UnOp::Neg, ref expr) => match expr.kind {
@@ -69,7 +89,7 @@ impl<'tcx> Const<'tcx> {
             // If an error occurred, ignore that it's a literal and leave reporting the error up to
             // mir.
             if let Ok(c) = tcx.at(expr.span).lit_to_const(lit_input) {
-                return c;
+                return Some(c);
             } else {
                 tcx.sess.delay_span_bug(expr.span, "Const::from_anon_const: couldn't lit_to_const");
             }
@@ -85,7 +105,7 @@ impl<'tcx> Const<'tcx> {
         };
 
         use hir::{def::DefKind::ConstParam, def::Res, ExprKind, Path, QPath};
-        let val = match expr.kind {
+        match expr.kind {
             ExprKind::Path(QPath::Resolved(_, &Path { res: Res::Def(ConstParam, def_id), .. })) => {
                 // Find the name and index of the const parameter by indexing the generics of
                 // the parent item and construct a `ParamConst`.
@@ -95,16 +115,53 @@ impl<'tcx> Const<'tcx> {
                 let generics = tcx.generics_of(item_def_id.to_def_id());
                 let index = generics.param_def_id_to_index[&def_id];
                 let name = tcx.hir().name(hir_id);
-                ty::ConstKind::Param(ty::ParamConst::new(index, name))
+                Some(tcx.mk_const(ty::Const {
+                    val: ty::ConstKind::Param(ty::ParamConst::new(index, name)),
+                    ty,
+                }))
             }
-            _ => ty::ConstKind::Unevaluated(ty::Unevaluated {
-                def: def.to_global(),
-                substs_: None,
-                promoted: None,
-            }),
+            _ => None,
+        }
+    }
+
+    pub fn from_inline_const(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &'tcx Self {
+        debug!("Const::from_inline_const(def_id={:?})", def_id);
+
+        let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
+
+        let body_id = match tcx.hir().get(hir_id) {
+            hir::Node::AnonConst(ac) => ac.body,
+            _ => span_bug!(
+                tcx.def_span(def_id.to_def_id()),
+                "from_inline_const can only process anonymous constants"
+            ),
         };
 
-        tcx.mk_const(ty::Const { val, ty })
+        let expr = &tcx.hir().body(body_id).value;
+
+        let ty = tcx.typeck(def_id).node_type(hir_id);
+
+        let ret = match Self::try_eval_lit_or_param(tcx, ty, expr) {
+            Some(v) => v,
+            None => {
+                let typeck_root_def_id = tcx.typeck_root_def_id(def_id.to_def_id());
+                let parent_substs =
+                    tcx.erase_regions(InternalSubsts::identity_for_item(tcx, typeck_root_def_id));
+                let substs =
+                    InlineConstSubsts::new(tcx, InlineConstSubstsParts { parent_substs, ty })
+                        .substs;
+                tcx.mk_const(ty::Const {
+                    val: ty::ConstKind::Unevaluated(ty::Unevaluated {
+                        def: ty::WithOptConstParam::unknown(def_id).to_global(),
+                        substs_: Some(substs),
+                        promoted: None,
+                    }),
+                    ty,
+                })
+            }
+        };
+        debug_assert!(!ret.has_free_regions(tcx));
+        ret
     }
 
     /// Interns the given value as a constant.
diff --git a/compiler/rustc_middle/src/ty/error.rs b/compiler/rustc_middle/src/ty/error.rs
index 2bd9415171d7d..b14a69892657b 100644
--- a/compiler/rustc_middle/src/ty/error.rs
+++ b/compiler/rustc_middle/src/ty/error.rs
@@ -42,6 +42,7 @@ pub enum TypeError<'tcx> {
     TupleSize(ExpectedFound<usize>),
     FixedArraySize(ExpectedFound<u64>),
     ArgCount,
+    FieldMisMatch(Symbol, Symbol),
 
     RegionsDoesNotOutlive(Region<'tcx>, Region<'tcx>),
     RegionsInsufficientlyPolymorphic(BoundRegionKind, Region<'tcx>),
@@ -134,6 +135,7 @@ impl<'tcx> fmt::Display for TypeError<'tcx> {
                 pluralize!(values.found)
             ),
             ArgCount => write!(f, "incorrect number of function parameters"),
+            FieldMisMatch(adt, field) => write!(f, "field type mismatch: {}.{}", adt, field),
             RegionsDoesNotOutlive(..) => write!(f, "lifetime mismatch"),
             RegionsInsufficientlyPolymorphic(br, _) => write!(
                 f,
@@ -224,6 +226,7 @@ impl<'tcx> TypeError<'tcx> {
             | ArgumentMutability(_)
             | TupleSize(_)
             | ArgCount
+            | FieldMisMatch(..)
             | RegionsDoesNotOutlive(..)
             | RegionsInsufficientlyPolymorphic(..)
             | RegionsOverlyPolymorphic(..)
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index cf47da157d19f..40670f1fdcaef 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -74,9 +74,10 @@ pub use self::sty::{
     Binder, BoundRegion, BoundRegionKind, BoundTy, BoundTyKind, BoundVar, BoundVariableKind,
     CanonicalPolyFnSig, ClosureSubsts, ClosureSubstsParts, ConstVid, EarlyBoundRegion,
     ExistentialPredicate, ExistentialProjection, ExistentialTraitRef, FnSig, FreeRegion, GenSig,
-    GeneratorSubsts, GeneratorSubstsParts, ParamConst, ParamTy, PolyExistentialProjection,
-    PolyExistentialTraitRef, PolyFnSig, PolyGenSig, PolyTraitRef, ProjectionTy, Region, RegionKind,
-    RegionVid, TraitRef, TyKind, TypeAndMut, UpvarSubsts, VarianceDiagInfo, VarianceDiagMutKind,
+    GeneratorSubsts, GeneratorSubstsParts, InlineConstSubsts, InlineConstSubstsParts, ParamConst,
+    ParamTy, PolyExistentialProjection, PolyExistentialTraitRef, PolyFnSig, PolyGenSig,
+    PolyTraitRef, ProjectionTy, Region, RegionKind, RegionVid, TraitRef, TyKind, TypeAndMut,
+    UpvarSubsts, VarianceDiagInfo, VarianceDiagMutKind,
 };
 pub use self::trait_def::TraitDef;
 
@@ -1927,7 +1928,8 @@ impl<'tcx> TyCtxt<'tcx> {
                 | DefKind::Static
                 | DefKind::AssocConst
                 | DefKind::Ctor(..)
-                | DefKind::AnonConst => self.mir_for_ctfe_opt_const_arg(def),
+                | DefKind::AnonConst
+                | DefKind::InlineConst => self.mir_for_ctfe_opt_const_arg(def),
                 // If the caller wants `mir_for_ctfe` of a function they should not be using
                 // `instance_mir`, so we'll assume const fn also wants the optimized version.
                 _ => {
diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs
index d6069395474ab..0f8e80806e31e 100644
--- a/compiler/rustc_middle/src/ty/structural_impls.rs
+++ b/compiler/rustc_middle/src/ty/structural_impls.rs
@@ -602,6 +602,7 @@ impl<'a, 'tcx> Lift<'tcx> for ty::error::TypeError<'a> {
             TupleSize(x) => TupleSize(x),
             FixedArraySize(x) => FixedArraySize(x),
             ArgCount => ArgCount,
+            FieldMisMatch(x, y) => FieldMisMatch(x, y),
             RegionsDoesNotOutlive(a, b) => {
                 return tcx.lift((a, b)).map(|(a, b)| RegionsDoesNotOutlive(a, b));
             }
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index 874de3366d792..e57075ed33811 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -704,6 +704,66 @@ impl<'tcx> UpvarSubsts<'tcx> {
     }
 }
 
+/// An inline const is modeled like
+///
+///     const InlineConst<'l0...'li, T0...Tj, R>: R;
+///
+/// where:
+///
+/// - 'l0...'li and T0...Tj are the generic parameters
+///   inherited from the item that defined the inline const,
+/// - R represents the type of the constant.
+///
+/// When the inline const is instantiated, `R` is substituted as the actual inferred
+/// type of the constant. The reason that `R` is represented as an extra type parameter
+/// is the same reason that [`ClosureSubsts`] have `CS` and `U` as type parameters:
+/// inline const can reference lifetimes that are internal to the creating function.
+#[derive(Copy, Clone, Debug, TypeFoldable)]
+pub struct InlineConstSubsts<'tcx> {
+    /// Generic parameters from the enclosing item,
+    /// concatenated with the inferred type of the constant.
+    pub substs: SubstsRef<'tcx>,
+}
+
+/// Struct returned by `split()`.
+pub struct InlineConstSubstsParts<'tcx, T> {
+    pub parent_substs: &'tcx [GenericArg<'tcx>],
+    pub ty: T,
+}
+
+impl<'tcx> InlineConstSubsts<'tcx> {
+    /// Construct `InlineConstSubsts` from `InlineConstSubstsParts`.
+    pub fn new(
+        tcx: TyCtxt<'tcx>,
+        parts: InlineConstSubstsParts<'tcx, Ty<'tcx>>,
+    ) -> InlineConstSubsts<'tcx> {
+        InlineConstSubsts {
+            substs: tcx.mk_substs(
+                parts.parent_substs.iter().copied().chain(std::iter::once(parts.ty.into())),
+            ),
+        }
+    }
+
+    /// Divides the inline const substs into their respective components.
+    /// The ordering assumed here must match that used by `InlineConstSubsts::new` above.
+    fn split(self) -> InlineConstSubstsParts<'tcx, GenericArg<'tcx>> {
+        match self.substs[..] {
+            [ref parent_substs @ .., ty] => InlineConstSubstsParts { parent_substs, ty },
+            _ => bug!("inline const substs missing synthetics"),
+        }
+    }
+
+    /// Returns the substitutions of the inline const's parent.
+    pub fn parent_substs(self) -> &'tcx [GenericArg<'tcx>] {
+        self.split().parent_substs
+    }
+
+    /// Returns the type of this inline const.
+    pub fn ty(self) -> Ty<'tcx> {
+        self.split().ty.expect_ty()
+    }
+}
+
 #[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Ord, Eq, Hash, TyEncodable, TyDecodable)]
 #[derive(HashStable, TypeFoldable)]
 pub enum ExistentialPredicate<'tcx> {
diff --git a/compiler/rustc_middle/src/ty/subst.rs b/compiler/rustc_middle/src/ty/subst.rs
index 2438d1a16021b..73a8e18949de0 100644
--- a/compiler/rustc_middle/src/ty/subst.rs
+++ b/compiler/rustc_middle/src/ty/subst.rs
@@ -3,7 +3,7 @@
 use crate::mir;
 use crate::ty::codec::{TyDecoder, TyEncoder};
 use crate::ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
-use crate::ty::sty::{ClosureSubsts, GeneratorSubsts};
+use crate::ty::sty::{ClosureSubsts, GeneratorSubsts, InlineConstSubsts};
 use crate::ty::{self, Lift, List, ParamConst, Ty, TyCtxt};
 
 use rustc_hir::def_id::DefId;
@@ -204,6 +204,14 @@ impl<'a, 'tcx> InternalSubsts<'tcx> {
         GeneratorSubsts { substs: self }
     }
 
+    /// Interpret these substitutions as the substitutions of an inline const.
+    /// Inline const substitutions have a particular structure controlled by the
+    /// compiler that encodes information like the inferred type;
+    /// see `ty::InlineConstSubsts` struct for more comments.
+    pub fn as_inline_const(&'tcx self) -> InlineConstSubsts<'tcx> {
+        InlineConstSubsts { substs: self }
+    }
+
     /// Creates an `InternalSubsts` that maps each generic parameter to itself.
     pub fn identity_for_item(tcx: TyCtxt<'tcx>, def_id: DefId) -> SubstsRef<'tcx> {
         Self::for_item(tcx, def_id, |param, _| tcx.mk_param_from_def(param))
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index 2c884813d2318..6b287445ff032 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -423,6 +423,15 @@ impl<'tcx> TyCtxt<'tcx> {
         matches!(self.def_kind(def_id), DefKind::Closure | DefKind::Generator)
     }
 
+    /// Returns `true` if `def_id` refers to a definition that does not have its own
+    /// type-checking context, i.e. closure, generator or inline const.
+    pub fn is_typeck_child(self, def_id: DefId) -> bool {
+        matches!(
+            self.def_kind(def_id),
+            DefKind::Closure | DefKind::Generator | DefKind::InlineConst
+        )
+    }
+
     /// Returns `true` if `def_id` refers to a trait (i.e., `trait Foo { ... }`).
     pub fn is_trait(self, def_id: DefId) -> bool {
         self.def_kind(def_id) == DefKind::Trait
@@ -440,16 +449,19 @@ impl<'tcx> TyCtxt<'tcx> {
         matches!(self.def_kind(def_id), DefKind::Ctor(..))
     }
 
-    /// Given the def-ID of a fn or closure, returns the def-ID of
-    /// the innermost fn item that the closure is contained within.
-    /// This is a significant `DefId` because, when we do
-    /// type-checking, we type-check this fn item and all of its
-    /// (transitive) closures together. Therefore, when we fetch the
+    /// Given the `DefId`, returns the `DefId` of the innermost item that
+    /// has its own type-checking context or "inference enviornment".
+    ///
+    /// For example, a closure has its own `DefId`, but it is type-checked
+    /// with the containing item. Similarly, an inline const block has its
+    /// own `DefId` but it is type-checked together with the containing item.
+    ///
+    /// Therefore, when we fetch the
     /// `typeck` the closure, for example, we really wind up
     /// fetching the `typeck` the enclosing fn item.
-    pub fn closure_base_def_id(self, def_id: DefId) -> DefId {
+    pub fn typeck_root_def_id(self, def_id: DefId) -> DefId {
         let mut def_id = def_id;
-        while self.is_closure(def_id) {
+        while self.is_typeck_child(def_id) {
             def_id = self.parent(def_id).unwrap_or_else(|| {
                 bug!("closure {:?} has no parent", def_id);
             });
diff --git a/compiler/rustc_mir_build/src/thir/cx/expr.rs b/compiler/rustc_mir_build/src/thir/cx/expr.rs
index 17296a95bc17e..b4005ccd1cc42 100644
--- a/compiler/rustc_mir_build/src/thir/cx/expr.rs
+++ b/compiler/rustc_mir_build/src/thir/cx/expr.rs
@@ -578,7 +578,7 @@ impl<'tcx> Cx<'tcx> {
 
             hir::ExprKind::ConstBlock(ref anon_const) => {
                 let anon_const_def_id = self.tcx.hir().local_def_id(anon_const.hir_id);
-                let value = ty::Const::from_anon_const(self.tcx, anon_const_def_id);
+                let value = ty::Const::from_inline_const(self.tcx, anon_const_def_id);
 
                 ExprKind::ConstBlock { value }
             }
diff --git a/compiler/rustc_mir_build/src/thir/pattern/mod.rs b/compiler/rustc_mir_build/src/thir/pattern/mod.rs
index cb74ae4df2ef8..ce80214c875fc 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/mod.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/mod.rs
@@ -544,7 +544,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
             let (lit, neg) = match expr.kind {
                 hir::ExprKind::ConstBlock(ref anon_const) => {
                     let anon_const_def_id = self.tcx.hir().local_def_id(anon_const.hir_id);
-                    let value = ty::Const::from_anon_const(self.tcx, anon_const_def_id);
+                    let value = ty::Const::from_inline_const(self.tcx, anon_const_def_id);
                     if matches!(value.val, ConstKind::Param(_)) {
                         let span = self.tcx.hir().span(anon_const.hir_id);
                         self.errors.push(PatternError::ConstParamInPattern(span));
diff --git a/compiler/rustc_monomorphize/src/partitioning/mod.rs b/compiler/rustc_monomorphize/src/partitioning/mod.rs
index 7a7a56a034ed2..658c9028ca1a1 100644
--- a/compiler/rustc_monomorphize/src/partitioning/mod.rs
+++ b/compiler/rustc_monomorphize/src/partitioning/mod.rs
@@ -361,6 +361,17 @@ fn collect_and_partition_mono_items<'tcx>(
         )
     });
 
+    if tcx.prof.enabled() {
+        // Record CGU size estimates for self-profiling.
+        for cgu in codegen_units {
+            tcx.prof.artifact_size(
+                "codegen_unit_size_estimate",
+                &cgu.name().as_str()[..],
+                cgu.size_estimate() as u64,
+            );
+        }
+    }
+
     let mono_items: DefIdSet = items
         .iter()
         .filter_map(|mono_item| match *mono_item {
diff --git a/compiler/rustc_monomorphize/src/polymorphize.rs b/compiler/rustc_monomorphize/src/polymorphize.rs
index e6e4438b6d41a..595080619da6f 100644
--- a/compiler/rustc_monomorphize/src/polymorphize.rs
+++ b/compiler/rustc_monomorphize/src/polymorphize.rs
@@ -167,6 +167,7 @@ fn mark_used_by_default_parameters<'tcx>(
         | DefKind::Use
         | DefKind::ForeignMod
         | DefKind::AnonConst
+        | DefKind::InlineConst
         | DefKind::OpaqueTy
         | DefKind::Field
         | DefKind::LifetimeParam
@@ -195,7 +196,7 @@ fn emit_unused_generic_params_error<'tcx>(
     generics: &'tcx ty::Generics,
     unused_parameters: &FiniteBitSet<u32>,
 ) {
-    let base_def_id = tcx.closure_base_def_id(def_id);
+    let base_def_id = tcx.typeck_root_def_id(def_id);
     if !tcx.get_attrs(base_def_id).iter().any(|a| a.has_name(sym::rustc_polymorphize_error)) {
         return;
     }
@@ -303,7 +304,7 @@ impl<'a, 'tcx> TypeVisitor<'tcx> for MarkUsedGenericParams<'a, 'tcx> {
                 ControlFlow::CONTINUE
             }
             ty::ConstKind::Unevaluated(uv)
-                if self.tcx.def_kind(uv.def.did) == DefKind::AnonConst =>
+                if matches!(self.tcx.def_kind(uv.def.did), DefKind::AnonConst | DefKind::InlineConst) =>
             {
                 self.visit_child_body(uv.def.did, uv.substs(self.tcx));
                 ControlFlow::CONTINUE
diff --git a/compiler/rustc_passes/src/region.rs b/compiler/rustc_passes/src/region.rs
index 5fc8e230d72a3..6a8feb041da19 100644
--- a/compiler/rustc_passes/src/region.rs
+++ b/compiler/rustc_passes/src/region.rs
@@ -334,9 +334,10 @@ fn resolve_expr<'tcx>(visitor: &mut RegionResolutionVisitor<'tcx>, expr: &'tcx h
     // properly, we can't miss any types.
 
     match expr.kind {
-        // Manually recurse over closures, because they are the only
+        // Manually recurse over closures and inline consts, because they are the only
         // case of nested bodies that share the parent environment.
-        hir::ExprKind::Closure(.., body, _, _) => {
+        hir::ExprKind::Closure(.., body, _, _)
+        | hir::ExprKind::ConstBlock(hir::AnonConst { body, .. }) => {
             let body = visitor.tcx.hir().body(body);
             visitor.visit_body(body);
         }
@@ -817,9 +818,9 @@ impl<'tcx> Visitor<'tcx> for RegionResolutionVisitor<'tcx> {
 }
 
 fn region_scope_tree(tcx: TyCtxt<'_>, def_id: DefId) -> &ScopeTree {
-    let closure_base_def_id = tcx.closure_base_def_id(def_id);
-    if closure_base_def_id != def_id {
-        return tcx.region_scope_tree(closure_base_def_id);
+    let typeck_root_def_id = tcx.typeck_root_def_id(def_id);
+    if typeck_root_def_id != def_id {
+        return tcx.region_scope_tree(typeck_root_def_id);
     }
 
     let id = tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs
index fa34b9abc1e6c..a01efc5d85c6e 100644
--- a/compiler/rustc_privacy/src/lib.rs
+++ b/compiler/rustc_privacy/src/lib.rs
@@ -618,6 +618,7 @@ impl EmbargoVisitor<'tcx> {
             | DefKind::Use
             | DefKind::ForeignMod
             | DefKind::AnonConst
+            | DefKind::InlineConst
             | DefKind::Field
             | DefKind::GlobalAsm
             | DefKind::Impl
diff --git a/compiler/rustc_resolve/src/build_reduced_graph.rs b/compiler/rustc_resolve/src/build_reduced_graph.rs
index d77a70e532799..4173e0fbf5668 100644
--- a/compiler/rustc_resolve/src/build_reduced_graph.rs
+++ b/compiler/rustc_resolve/src/build_reduced_graph.rs
@@ -967,6 +967,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 | DefKind::Use
                 | DefKind::ForeignMod
                 | DefKind::AnonConst
+                | DefKind::InlineConst
                 | DefKind::Field
                 | DefKind::LifetimeParam
                 | DefKind::GlobalAsm
diff --git a/compiler/rustc_resolve/src/late/lifetimes.rs b/compiler/rustc_resolve/src/late/lifetimes.rs
index 5def43c242344..39e710cb77f3f 100644
--- a/compiler/rustc_resolve/src/late/lifetimes.rs
+++ b/compiler/rustc_resolve/src/late/lifetimes.rs
@@ -540,7 +540,7 @@ fn is_late_bound_map<'tcx>(
     def_id: LocalDefId,
 ) -> Option<(LocalDefId, &'tcx FxHashSet<ItemLocalId>)> {
     match tcx.def_kind(def_id) {
-        DefKind::AnonConst => {
+        DefKind::AnonConst | DefKind::InlineConst => {
             let mut def_id = tcx
                 .parent(def_id.to_def_id())
                 .unwrap_or_else(|| bug!("anon const or closure without a parent"));
diff --git a/compiler/rustc_save_analysis/src/lib.rs b/compiler/rustc_save_analysis/src/lib.rs
index 543cd0247a53d..c7f8fe3a88a64 100644
--- a/compiler/rustc_save_analysis/src/lib.rs
+++ b/compiler/rustc_save_analysis/src/lib.rs
@@ -739,6 +739,7 @@ impl<'tcx> SaveContext<'tcx> {
                 | HirDefKind::ForeignMod
                 | HirDefKind::LifetimeParam
                 | HirDefKind::AnonConst
+                | HirDefKind::InlineConst
                 | HirDefKind::Use
                 | HirDefKind::Field
                 | HirDefKind::GlobalAsm
diff --git a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs
index 8edb7069fc45f..6b5d37c0f4308 100644
--- a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs
+++ b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs
@@ -151,7 +151,7 @@ pub fn is_const_evaluatable<'cx, 'tcx>(
 
     if concrete.is_ok() && uv.substs(infcx.tcx).definitely_has_param_types_or_consts(infcx.tcx) {
         match infcx.tcx.def_kind(uv.def.did) {
-            DefKind::AnonConst => {
+            DefKind::AnonConst | DefKind::InlineConst => {
                 let mir_body = infcx.tcx.mir_for_ctfe_opt_const_arg(uv.def);
 
                 if mir_body.is_polymorphic {
@@ -495,7 +495,7 @@ pub(super) fn thir_abstract_const<'tcx>(
             // we want to look into them or treat them as opaque projections.
             //
             // Right now we do neither of that and simply always fail to unify them.
-            DefKind::AnonConst => (),
+            DefKind::AnonConst | DefKind::InlineConst => (),
             _ => return Ok(None),
         }
 
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index 2689e2134fc6b..b21936a00b04f 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -1474,7 +1474,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
         let span = self.tcx.def_span(generator_did);
 
         let in_progress_typeck_results = self.in_progress_typeck_results.map(|t| t.borrow());
-        let generator_did_root = self.tcx.closure_base_def_id(generator_did);
+        let generator_did_root = self.tcx.typeck_root_def_id(generator_did);
         debug!(
             "maybe_note_obligation_cause_for_async_await: generator_did={:?} \
              generator_did_root={:?} in_progress_typeck_results.hir_owner={:?} span={:?}",
diff --git a/compiler/rustc_typeck/src/check/closure.rs b/compiler/rustc_typeck/src/check/closure.rs
index 410ac24b1f19c..f7accbb430caa 100644
--- a/compiler/rustc_typeck/src/check/closure.rs
+++ b/compiler/rustc_typeck/src/check/closure.rs
@@ -92,7 +92,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         let parent_substs = InternalSubsts::identity_for_item(
             self.tcx,
-            self.tcx.closure_base_def_id(expr_def_id.to_def_id()),
+            self.tcx.typeck_root_def_id(expr_def_id.to_def_id()),
         );
 
         let tupled_upvars_ty = self.infcx.next_ty_var(TypeVariableOrigin {
diff --git a/compiler/rustc_typeck/src/check/expr.rs b/compiler/rustc_typeck/src/check/expr.rs
index 3cba7991ccaf3..a9c0b65a0981e 100644
--- a/compiler/rustc_typeck/src/check/expr.rs
+++ b/compiler/rustc_typeck/src/check/expr.rs
@@ -30,15 +30,20 @@ use rustc_errors::{pluralize, struct_span_err, Applicability, DiagnosticBuilder,
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, DefKind, Res};
 use rustc_hir::def_id::DefId;
+use rustc_hir::intravisit::Visitor;
 use rustc_hir::{ExprKind, QPath};
 use rustc_infer::infer;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
+use rustc_infer::infer::InferOk;
 use rustc_middle::ty;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, AllowTwoPhase};
+use rustc_middle::ty::error::TypeError::{FieldMisMatch, Sorts};
+use rustc_middle::ty::relate::expected_found_bool;
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::Ty;
 use rustc_middle::ty::TypeFoldable;
 use rustc_middle::ty::{AdtKind, Visibility};
+use rustc_session::parse::feature_err;
 use rustc_span::edition::LATEST_STABLE_EDITION;
 use rustc_span::hygiene::DesugaringKind;
 use rustc_span::lev_distance::find_best_match_for_name;
@@ -323,7 +328,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
             ExprKind::DropTemps(e) => self.check_expr_with_expectation(e, expected),
             ExprKind::Array(args) => self.check_expr_array(args, expected, expr),
-            ExprKind::ConstBlock(ref anon_const) => self.to_const(anon_const).ty,
+            ExprKind::ConstBlock(ref anon_const) => {
+                self.check_expr_const_block(anon_const, expected, expr)
+            }
             ExprKind::Repeat(element, ref count) => {
                 self.check_expr_repeat(element, count, expected, expr)
             }
@@ -1166,6 +1173,24 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self.tcx.mk_array(element_ty, args.len() as u64)
     }
 
+    fn check_expr_const_block(
+        &self,
+        anon_const: &'tcx hir::AnonConst,
+        expected: Expectation<'tcx>,
+        _expr: &'tcx hir::Expr<'tcx>,
+    ) -> Ty<'tcx> {
+        let body = self.tcx.hir().body(anon_const.body);
+
+        // Create a new function context.
+        let fcx = FnCtxt::new(self, self.param_env, body.value.hir_id);
+        crate::check::GatherLocalsVisitor::new(&fcx).visit_body(body);
+
+        let ty = fcx.check_expr_with_expectation(&body.value, expected);
+        fcx.require_type_is_sized(ty, body.value.span, traits::ConstSized);
+        fcx.write_ty(anon_const.hir_id, ty);
+        ty
+    }
+
     fn check_expr_repeat(
         &self,
         element: &'tcx hir::Expr<'tcx>,
@@ -1262,49 +1287,17 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 .emit_err(StructExprNonExhaustive { span: expr.span, what: adt.variant_descr() });
         }
 
-        let error_happened = self.check_expr_struct_fields(
+        self.check_expr_struct_fields(
             adt_ty,
             expected,
             expr.hir_id,
             qpath.span(),
             variant,
             fields,
-            base_expr.is_none(),
+            base_expr,
             expr.span,
         );
-        if let Some(base_expr) = base_expr {
-            // If check_expr_struct_fields hit an error, do not attempt to populate
-            // the fields with the base_expr. This could cause us to hit errors later
-            // when certain fields are assumed to exist that in fact do not.
-            if !error_happened {
-                self.check_expr_has_type_or_error(base_expr, adt_ty, |_| {});
-                match adt_ty.kind() {
-                    ty::Adt(adt, substs) if adt.is_struct() => {
-                        let fru_field_types = adt
-                            .non_enum_variant()
-                            .fields
-                            .iter()
-                            .map(|f| {
-                                self.normalize_associated_types_in(
-                                    expr.span,
-                                    f.ty(self.tcx, substs),
-                                )
-                            })
-                            .collect();
-
-                        self.typeck_results
-                            .borrow_mut()
-                            .fru_field_types_mut()
-                            .insert(expr.hir_id, fru_field_types);
-                    }
-                    _ => {
-                        self.tcx
-                            .sess
-                            .emit_err(FunctionalRecordUpdateOnNonStruct { span: base_expr.span });
-                    }
-                }
-            }
-        }
+
         self.require_type_is_sized(adt_ty, expr.span, traits::StructInitializerSized);
         adt_ty
     }
@@ -1317,9 +1310,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         span: Span,
         variant: &'tcx ty::VariantDef,
         ast_fields: &'tcx [hir::ExprField<'tcx>],
-        check_completeness: bool,
+        base_expr: &'tcx Option<&'tcx hir::Expr<'tcx>>,
         expr_span: Span,
-    ) -> bool {
+    ) {
         let tcx = self.tcx;
 
         let adt_ty_hint = self
@@ -1394,7 +1387,116 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 )
                 .emit();
             }
-        } else if check_completeness && !error_happened && !remaining_fields.is_empty() {
+        }
+
+        // If check_expr_struct_fields hit an error, do not attempt to populate
+        // the fields with the base_expr. This could cause us to hit errors later
+        // when certain fields are assumed to exist that in fact do not.
+        if error_happened {
+            return;
+        }
+
+        if let Some(base_expr) = base_expr {
+            // FIXME: We are currently creating two branches here in order to maintain
+            // consistency. But they should be merged as much as possible.
+            let fru_tys = if self.tcx.features().type_changing_struct_update {
+                let base_ty = self.check_expr(base_expr);
+                match adt_ty.kind() {
+                    ty::Adt(adt, substs) if adt.is_struct() => {
+                        match base_ty.kind() {
+                            ty::Adt(base_adt, base_subs) if adt == base_adt => {
+                                variant
+                                    .fields
+                                    .iter()
+                                    .map(|f| {
+                                        let fru_ty = self.normalize_associated_types_in(
+                                            expr_span,
+                                            self.field_ty(base_expr.span, f, base_subs),
+                                        );
+                                        let ident = self.tcx.adjust_ident(f.ident, variant.def_id);
+                                        if let Some(_) = remaining_fields.remove(&ident) {
+                                            let target_ty =
+                                                self.field_ty(base_expr.span, f, substs);
+                                            let cause = self.misc(base_expr.span);
+                                            match self
+                                                .at(&cause, self.param_env)
+                                                .sup(target_ty, fru_ty)
+                                            {
+                                                Ok(InferOk { obligations, value: () }) => {
+                                                    self.register_predicates(obligations)
+                                                }
+                                                // FIXME: Need better diagnostics for `FieldMisMatch` error
+                                                Err(_) => self
+                                                    .report_mismatched_types(
+                                                        &cause,
+                                                        target_ty,
+                                                        fru_ty,
+                                                        FieldMisMatch(
+                                                            variant.ident.name,
+                                                            ident.name,
+                                                        ),
+                                                    )
+                                                    .emit(),
+                                            }
+                                        }
+                                        fru_ty
+                                    })
+                                    .collect()
+                            }
+                            _ => {
+                                return self
+                                    .report_mismatched_types(
+                                        &self.misc(base_expr.span),
+                                        adt_ty,
+                                        base_ty,
+                                        Sorts(expected_found_bool(true, adt_ty, base_ty)),
+                                    )
+                                    .emit();
+                            }
+                        }
+                    }
+                    _ => {
+                        return self
+                            .tcx
+                            .sess
+                            .emit_err(FunctionalRecordUpdateOnNonStruct { span: base_expr.span });
+                    }
+                }
+            } else {
+                self.check_expr_has_type_or_error(base_expr, adt_ty, |_| {
+                    let base_ty = self.check_expr(base_expr);
+                    let same_adt = match (adt_ty.kind(), base_ty.kind()) {
+                        (ty::Adt(adt, _), ty::Adt(base_adt, _)) if adt == base_adt => true,
+                        _ => false,
+                    };
+                    if self.tcx.sess.is_nightly_build() && same_adt {
+                        feature_err(
+                            &self.tcx.sess.parse_sess,
+                            sym::type_changing_struct_update,
+                            base_expr.span,
+                            "type changing struct updating is experimental",
+                        )
+                        .emit();
+                    }
+                });
+                match adt_ty.kind() {
+                    ty::Adt(adt, substs) if adt.is_struct() => variant
+                        .fields
+                        .iter()
+                        .map(|f| {
+                            self.normalize_associated_types_in(expr_span, f.ty(self.tcx, substs))
+                        })
+                        .collect(),
+                    _ => {
+                        return self
+                            .tcx
+                            .sess
+                            .emit_err(FunctionalRecordUpdateOnNonStruct { span: base_expr.span });
+                    }
+                }
+            };
+            self.typeck_results.borrow_mut().fru_field_types_mut().insert(expr_id, fru_tys);
+        } else if kind_name != "union" && !remaining_fields.is_empty() {
             let inaccessible_remaining_fields = remaining_fields.iter().any(|(_, (_, field))| {
                 !field.vis.is_accessible_from(tcx.parent_module(expr_id).to_def_id(), tcx)
             });
@@ -1405,8 +1507,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 self.report_missing_fields(adt_ty, span, remaining_fields);
             }
         }
-
-        error_happened
     }
 
     fn check_struct_fields_on_error(
diff --git a/compiler/rustc_typeck/src/check/mod.rs b/compiler/rustc_typeck/src/check/mod.rs
index 7450b4a4ef1c3..d19e99606bcd8 100644
--- a/compiler/rustc_typeck/src/check/mod.rs
+++ b/compiler/rustc_typeck/src/check/mod.rs
@@ -297,9 +297,9 @@ fn primary_body_of(
 fn has_typeck_results(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
     // Closures' typeck results come from their outermost function,
     // as they are part of the same "inference environment".
-    let outer_def_id = tcx.closure_base_def_id(def_id);
-    if outer_def_id != def_id {
-        return tcx.has_typeck_results(outer_def_id);
+    let typeck_root_def_id = tcx.typeck_root_def_id(def_id);
+    if typeck_root_def_id != def_id {
+        return tcx.has_typeck_results(typeck_root_def_id);
     }
 
     if let Some(def_id) = def_id.as_local() {
@@ -348,9 +348,9 @@ fn typeck_with_fallback<'tcx>(
 ) -> &'tcx ty::TypeckResults<'tcx> {
     // Closures' typeck results come from their outermost function,
     // as they are part of the same "inference environment".
-    let outer_def_id = tcx.closure_base_def_id(def_id.to_def_id()).expect_local();
-    if outer_def_id != def_id {
-        return tcx.typeck(outer_def_id);
+    let typeck_root_def_id = tcx.typeck_root_def_id(def_id.to_def_id()).expect_local();
+    if typeck_root_def_id != def_id {
+        return tcx.typeck(typeck_root_def_id);
     }
 
     let id = tcx.hir().local_def_id_to_hir_id(def_id);
diff --git a/compiler/rustc_typeck/src/check/pat.rs b/compiler/rustc_typeck/src/check/pat.rs
index 5aa11cce25fb6..cbf33cf1b78a1 100644
--- a/compiler/rustc_typeck/src/check/pat.rs
+++ b/compiler/rustc_typeck/src/check/pat.rs
@@ -292,7 +292,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // String and byte-string literals result in types `&str` and `&[u8]` respectively.
             // All other literals result in non-reference types.
             // As a result, we allow `if let 0 = &&0 {}` but not `if let "foo" = &&"foo {}`.
-            PatKind::Lit(lt) => match self.check_expr(lt).kind() {
+            //
+            // Call `resolve_vars_if_possible` here for inline const blocks.
+            PatKind::Lit(lt) => match self.resolve_vars_if_possible(self.check_expr(lt)).kind() {
                 ty::Ref(..) => AdjustMode::Pass,
                 _ => AdjustMode::Peel,
             },
diff --git a/compiler/rustc_typeck/src/check/regionck.rs b/compiler/rustc_typeck/src/check/regionck.rs
index 86d4e4d2b115b..d2d8b14dd9695 100644
--- a/compiler/rustc_typeck/src/check/regionck.rs
+++ b/compiler/rustc_typeck/src/check/regionck.rs
@@ -341,6 +341,29 @@ impl<'a, 'tcx> RegionCtxt<'a, 'tcx> {
         self.visit_region_obligations(body_id.hir_id);
     }
 
+    fn visit_inline_const(&mut self, id: hir::HirId, body: &'tcx hir::Body<'tcx>) {
+        debug!("visit_inline_const(id={:?})", id);
+
+        // Save state of current function. We will restore afterwards.
+        let old_body_id = self.body_id;
+        let old_body_owner = self.body_owner;
+        let env_snapshot = self.outlives_environment.push_snapshot_pre_typeck_child();
+
+        let body_id = body.id();
+        self.body_id = body_id.hir_id;
+        self.body_owner = self.tcx.hir().body_owner_def_id(body_id);
+
+        self.outlives_environment.save_implied_bounds(body_id.hir_id);
+
+        self.visit_body(body);
+        self.visit_region_obligations(body_id.hir_id);
+
+        // Restore state from previous function.
+        self.outlives_environment.pop_snapshot_post_typeck_child(env_snapshot);
+        self.body_id = old_body_id;
+        self.body_owner = old_body_owner;
+    }
+
     fn visit_region_obligations(&mut self, hir_id: hir::HirId) {
         debug!("visit_region_obligations: hir_id={:?}", hir_id);
 
@@ -406,13 +429,13 @@ impl<'a, 'tcx> Visitor<'tcx> for RegionCtxt<'a, 'tcx> {
         // `visit_fn_body`.  We will restore afterwards.
         let old_body_id = self.body_id;
         let old_body_owner = self.body_owner;
-        let env_snapshot = self.outlives_environment.push_snapshot_pre_closure();
+        let env_snapshot = self.outlives_environment.push_snapshot_pre_typeck_child();
 
         let body = self.tcx.hir().body(body_id);
         self.visit_fn_body(hir_id, body, span);
 
         // Restore state from previous function.
-        self.outlives_environment.pop_snapshot_post_closure(env_snapshot);
+        self.outlives_environment.pop_snapshot_post_typeck_child(env_snapshot);
         self.body_id = old_body_id;
         self.body_owner = old_body_owner;
     }
@@ -460,6 +483,11 @@ impl<'a, 'tcx> Visitor<'tcx> for RegionCtxt<'a, 'tcx> {
                 intravisit::walk_expr(self, expr);
             }
 
+            hir::ExprKind::ConstBlock(anon_const) => {
+                let body = self.tcx.hir().body(anon_const.body);
+                self.visit_inline_const(anon_const.hir_id, body);
+            }
+
             _ => intravisit::walk_expr(self, expr),
         }
     }
diff --git a/compiler/rustc_typeck/src/check/upvar.rs b/compiler/rustc_typeck/src/check/upvar.rs
index 774d8078e52ca..5f5d308a3329b 100644
--- a/compiler/rustc_typeck/src/check/upvar.rs
+++ b/compiler/rustc_typeck/src/check/upvar.rs
@@ -148,10 +148,17 @@ impl<'a, 'tcx> Visitor<'tcx> for InferBorrowKindVisitor<'a, 'tcx> {
     }
 
     fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
-        if let hir::ExprKind::Closure(cc, _, body_id, _, _) = expr.kind {
-            let body = self.fcx.tcx.hir().body(body_id);
-            self.visit_body(body);
-            self.fcx.analyze_closure(expr.hir_id, expr.span, body_id, body, cc);
+        match expr.kind {
+            hir::ExprKind::Closure(cc, _, body_id, _, _) => {
+                let body = self.fcx.tcx.hir().body(body_id);
+                self.visit_body(body);
+                self.fcx.analyze_closure(expr.hir_id, expr.span, body_id, body, cc);
+            }
+            hir::ExprKind::ConstBlock(anon_const) => {
+                let body = self.fcx.tcx.hir().body(anon_const.body);
+                self.visit_body(body);
+            }
+            _ => {}
         }
 
         intravisit::walk_expr(self, expr);
diff --git a/compiler/rustc_typeck/src/check/writeback.rs b/compiler/rustc_typeck/src/check/writeback.rs
index d951df94dcf50..fdc8b6b5e6451 100644
--- a/compiler/rustc_typeck/src/check/writeback.rs
+++ b/compiler/rustc_typeck/src/check/writeback.rs
@@ -282,6 +282,12 @@ impl<'cx, 'tcx> Visitor<'tcx> for WritebackCx<'cx, 'tcx> {
             hir::ExprKind::Field(..) => {
                 self.visit_field_id(e.hir_id);
             }
+            hir::ExprKind::ConstBlock(anon_const) => {
+                self.visit_node_id(e.span, anon_const.hir_id);
+
+                let body = self.tcx().hir().body(anon_const.body);
+                self.visit_body(body);
+            }
             _ => {}
         }
 
diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs
index 18e8ed394e814..2274db76c05fb 100644
--- a/compiler/rustc_typeck/src/collect.rs
+++ b/compiler/rustc_typeck/src/collect.rs
@@ -1494,13 +1494,15 @@ fn generics_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Generics {
                     {
                         Some(parent_def_id.to_def_id())
                     }
-
+                    Node::Expr(&Expr { kind: ExprKind::ConstBlock(_), .. }) => {
+                        Some(tcx.typeck_root_def_id(def_id))
+                    }
                     _ => None,
                 }
             }
         }
         Node::Expr(&hir::Expr { kind: hir::ExprKind::Closure(..), .. }) => {
-            Some(tcx.closure_base_def_id(def_id))
+            Some(tcx.typeck_root_def_id(def_id))
         }
         Node::Item(item) => match item.kind {
             ItemKind::OpaqueTy(hir::OpaqueTy { impl_trait_fn, .. }) => {
@@ -1692,6 +1694,24 @@ fn generics_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Generics {
         }));
     }
 
+    // provide junk type parameter defs for const blocks.
+    if let Node::AnonConst(_) = node {
+        let parent_node = tcx.hir().get(tcx.hir().get_parent_node(hir_id));
+        if let Node::Expr(&Expr { kind: ExprKind::ConstBlock(_), .. }) = parent_node {
+            params.push(ty::GenericParamDef {
+                index: type_start,
+                name: Symbol::intern("<const_ty>"),
+                def_id,
+                pure_wrt_drop: false,
+                kind: ty::GenericParamDefKind::Type {
+                    has_default: false,
+                    object_lifetime_default: rl::Set1::Empty,
+                    synthetic: None,
+                },
+            });
+        }
+    }
+
     let param_def_id_to_index = params.iter().map(|param| (param.def_id, param.index)).collect();
 
     ty::Generics {
diff --git a/compiler/rustc_typeck/src/collect/type_of.rs b/compiler/rustc_typeck/src/collect/type_of.rs
index a6ea8abdf3fa6..04a68250ced0c 100644
--- a/compiler/rustc_typeck/src/collect/type_of.rs
+++ b/compiler/rustc_typeck/src/collect/type_of.rs
@@ -494,7 +494,8 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: DefId) -> Ty<'_> {
                 Node::Expr(&Expr { kind: ExprKind::ConstBlock(ref anon_const), .. })
                     if anon_const.hir_id == hir_id =>
                 {
-                    tcx.typeck(def_id).node_type(anon_const.hir_id)
+                    let substs = InternalSubsts::identity_for_item(tcx, def_id.to_def_id());
+                    substs.as_inline_const().ty()
                 }
 
                 Node::Expr(&Expr { kind: ExprKind::InlineAsm(asm), .. })
diff --git a/library/alloc/src/boxed.rs b/library/alloc/src/boxed.rs
index bd4f52560421b..f6332b072cf30 100644
--- a/library/alloc/src/boxed.rs
+++ b/library/alloc/src/boxed.rs
@@ -169,6 +169,9 @@ use crate::vec::Vec;
 #[lang = "owned_box"]
 #[fundamental]
 #[stable(feature = "rust1", since = "1.0.0")]
+// The declaration of the `Box` struct must be kept in sync with the
+// `alloc::alloc::box_free` function or ICEs will happen. See the comment
+// on `box_free` for more details.
 pub struct Box<
     T: ?Sized,
     #[unstable(feature = "allocator_api", issue = "32838")] A: Allocator = Global,
diff --git a/src/bootstrap/dist.rs b/src/bootstrap/dist.rs
index d4875cfe1b066..a799732adde9d 100644
--- a/src/bootstrap/dist.rs
+++ b/src/bootstrap/dist.rs
@@ -96,7 +96,8 @@ impl Step for RustcDocs {
     const DEFAULT: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("src/librustc")
+        let builder = run.builder;
+        run.path("rustc-docs").default_condition(builder.config.compiler_docs)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -106,9 +107,6 @@ impl Step for RustcDocs {
     /// Builds the `rustc-docs` installer component.
     fn run(self, builder: &Builder<'_>) -> Option<GeneratedTarball> {
         let host = self.host;
-        if !builder.config.compiler_docs {
-            return None;
-        }
         builder.default_doc(&[]);
 
         let mut tarball = Tarball::new(builder, "rustc-docs", &host.triple);
diff --git a/src/bootstrap/doc.rs b/src/bootstrap/doc.rs
index 2804e7119fbc1..f0f31c447bda4 100644
--- a/src/bootstrap/doc.rs
+++ b/src/bootstrap/doc.rs
@@ -529,7 +529,7 @@ impl Step for Rustc {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
-        run.krate("rustc-main").path("compiler").default_condition(builder.config.docs)
+        run.krate("rustc-main").path("compiler").default_condition(builder.config.compiler_docs)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -560,11 +560,6 @@ impl Step for Rustc {
             })
             .collect::<Vec<_>>();
 
-        if !builder.config.compiler_docs && !builder.was_invoked_explicitly::<Self>() {
-            builder.info("\tskipping - compiler/librustdoc docs disabled");
-            return;
-        }
-
         // This is the intended out directory for compiler documentation.
         let out = builder.compiler_doc_out(target);
         t!(fs::create_dir_all(&out));
@@ -674,7 +669,8 @@ macro_rules! tool_doc {
             const ONLY_HOSTS: bool = true;
 
             fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-                run.krate($should_run)
+                let builder = run.builder;
+                run.krate($should_run).default_condition(builder.config.compiler_docs)
             }
 
             fn make_run(run: RunConfig<'_>) {
@@ -705,11 +701,6 @@ macro_rules! tool_doc {
 
                 let compiler = builder.compiler(stage, builder.config.build);
 
-                if !builder.config.compiler_docs && !builder.was_invoked_explicitly::<Self>() {
-                    builder.info("\tskipping - compiler/tool docs disabled");
-                    return;
-                }
-
                 // Build rustc docs so that we generate relative links.
                 builder.ensure(Rustc { stage, target });
 
diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index 8594fa42266b4..22bf6b8a9d4dc 100644
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -763,7 +763,7 @@ impl Step for RustdocJSStd {
     const ONLY_HOSTS: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("src/test/rustdoc-js-std")
+        run.suite_path("src/test/rustdoc-js-std")
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -783,6 +783,17 @@ impl Step for RustdocJSStd {
                 .arg(builder.doc_out(self.target))
                 .arg("--test-folder")
                 .arg(builder.src.join("src/test/rustdoc-js-std"));
+            for path in &builder.paths {
+                if let Some(p) =
+                    util::is_valid_test_suite_arg(path, "src/test/rustdoc-js-std", builder)
+                {
+                    if !p.ends_with(".js") {
+                        eprintln!("A non-js file was given: `{}`", path.display());
+                        panic!("Cannot run rustdoc-js-std tests");
+                    }
+                    command.arg("--test-file").arg(path);
+                }
+            }
             builder.ensure(crate::doc::Std { target: self.target, stage: builder.top_stage });
             builder.run(&mut command);
         } else {
@@ -803,7 +814,7 @@ impl Step for RustdocJSNotStd {
     const ONLY_HOSTS: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("src/test/rustdoc-js")
+        run.suite_path("src/test/rustdoc-js")
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -938,8 +949,12 @@ impl Step for RustdocGUI {
             .arg("--tests-folder")
             .arg(builder.build.src.join("src/test/rustdoc-gui"));
         for path in &builder.paths {
-            if let Some(name) = path.file_name().and_then(|f| f.to_str()) {
-                if name.ends_with(".goml") {
+            if let Some(p) = util::is_valid_test_suite_arg(path, "src/test/rustdoc-gui", builder) {
+                if !p.ends_with(".goml") {
+                    eprintln!("A non-goml file was given: `{}`", path.display());
+                    panic!("Cannot run rustdoc-gui tests");
+                }
+                if let Some(name) = path.file_name().and_then(|f| f.to_str()) {
                     command.arg("--file").arg(name);
                 }
             }
@@ -1416,35 +1431,7 @@ note: if you're sure you want to do this, please open an issue as to why. In the
         // Get test-args by striping suite path
         let mut test_args: Vec<&str> = paths
             .iter()
-            .map(|p| match p.strip_prefix(".") {
-                Ok(path) => path,
-                Err(_) => p,
-            })
-            .filter(|p| p.starts_with(suite_path))
-            .filter(|p| {
-                let exists = p.is_dir() || p.is_file();
-                if !exists {
-                    if let Some(p) = p.to_str() {
-                        builder.info(&format!(
-                            "Warning: Skipping \"{}\": not a regular file or directory",
-                            p
-                        ));
-                    }
-                }
-                exists
-            })
-            .filter_map(|p| {
-                // Since test suite paths are themselves directories, if we don't
-                // specify a directory or file, we'll get an empty string here
-                // (the result of the test suite directory without its suite prefix).
-                // Therefore, we need to filter these out, as only the first --test-args
-                // flag is respected, so providing an empty --test-args conflicts with
-                // any following it.
-                match p.strip_prefix(suite_path).ok().and_then(|p| p.to_str()) {
-                    Some(s) if !s.is_empty() => Some(s),
-                    _ => None,
-                }
-            })
+            .filter_map(|p| util::is_valid_test_suite_arg(p, suite_path, builder))
             .collect();
 
         test_args.append(&mut builder.config.cmd.test_args());
diff --git a/src/bootstrap/tool.rs b/src/bootstrap/tool.rs
index af6f4bb0e5fcb..1317c3f983975 100644
--- a/src/bootstrap/tool.rs
+++ b/src/bootstrap/tool.rs
@@ -286,7 +286,6 @@ macro_rules! bootstrap_tool {
         $name:ident, $path:expr, $tool_name:expr
         $(,is_external_tool = $external:expr)*
         $(,is_unstable_tool = $unstable:expr)*
-        $(,features = $features:expr)*
         ;
     )+) => {
         #[derive(Copy, PartialEq, Eq, Clone)]
@@ -349,12 +348,7 @@ macro_rules! bootstrap_tool {
                     } else {
                         SourceType::InTree
                     },
-                    extra_features: {
-                        // FIXME(#60643): avoid this lint by using `_`
-                        let mut _tmp = Vec::new();
-                        $(_tmp.extend($features);)*
-                        _tmp
-                    },
+                    extra_features: vec![],
                 }).expect("expected to build -- essential tool")
             }
         }
diff --git a/src/bootstrap/util.rs b/src/bootstrap/util.rs
index 112979b0bebc8..57178aa382ffd 100644
--- a/src/bootstrap/util.rs
+++ b/src/bootstrap/util.rs
@@ -310,3 +310,35 @@ pub fn use_host_linker(target: TargetSelection) -> bool {
         || target.contains("fuchsia")
         || target.contains("bpf"))
 }
+
+pub fn is_valid_test_suite_arg<'a, P: AsRef<Path>>(
+    path: &'a Path,
+    suite_path: P,
+    builder: &Builder<'_>,
+) -> Option<&'a str> {
+    let suite_path = suite_path.as_ref();
+    let path = match path.strip_prefix(".") {
+        Ok(p) => p,
+        Err(_) => path,
+    };
+    if !path.starts_with(suite_path) {
+        return None;
+    }
+    let exists = path.is_dir() || path.is_file();
+    if !exists {
+        if let Some(p) = path.to_str() {
+            builder.info(&format!("Warning: Skipping \"{}\": not a regular file or directory", p));
+        }
+        return None;
+    }
+    // Since test suite paths are themselves directories, if we don't
+    // specify a directory or file, we'll get an empty string here
+    // (the result of the test suite directory without its suite prefix).
+    // Therefore, we need to filter these out, as only the first --test-args
+    // flag is respected, so providing an empty --test-args conflicts with
+    // any following it.
+    match path.strip_prefix(suite_path).ok().and_then(|p| p.to_str()) {
+        Some(s) if !s.is_empty() => Some(s),
+        _ => None,
+    }
+}
diff --git a/src/doc/unstable-book/src/language-features/type-changing-struct-update.md b/src/doc/unstable-book/src/language-features/type-changing-struct-update.md
new file mode 100644
index 0000000000000..9909cf35b5b51
--- /dev/null
+++ b/src/doc/unstable-book/src/language-features/type-changing-struct-update.md
@@ -0,0 +1,33 @@
+# `type_changing_struct_update`
+
+The tracking issue for this feature is: [#86555]
+
+[#86555]: https://github.com/rust-lang/rust/issues/86555
+
+------------------------
+
+This implements [RFC2528]. When turned on, you can create instances of the same struct
+that have different generic type or lifetime parameters.
+
+[RFC2528]: https://github.com/rust-lang/rfcs/blob/master/text/2528-type-changing-struct-update-syntax.md
+
+```rust
+#![allow(unused_variables, dead_code)]
+#![feature(type_changing_struct_update)]
+
+fn main () {
+    struct Foo<T, U> {
+        field1: T,
+        field2: U,
+    }
+
+    let base: Foo<String, i32> = Foo {
+        field1: String::from("hello"),
+        field2: 1234,
+    };
+    let updated: Foo<f64, i32> = Foo {
+        field1: 3.14,
+        ..base
+    };
+}
+```
diff --git a/src/librustdoc/clean/utils.rs b/src/librustdoc/clean/utils.rs
index 2fae3163a1a1a..2fa7efcc6509b 100644
--- a/src/librustdoc/clean/utils.rs
+++ b/src/librustdoc/clean/utils.rs
@@ -430,8 +430,9 @@ crate fn register_res(cx: &mut DocContext<'_>, res: Res) -> DefId {
         | Res::NonMacroAttr(_)
         | Res::Err => return res.def_id(),
         Res::Def(
-            TyParam | ConstParam | Ctor(..) | ExternCrate | Use | ForeignMod | AnonConst | OpaqueTy
-            | Field | LifetimeParam | GlobalAsm | Impl | Closure | Generator,
+            TyParam | ConstParam | Ctor(..) | ExternCrate | Use | ForeignMod | AnonConst
+            | InlineConst | OpaqueTy | Field | LifetimeParam | GlobalAsm | Impl | Closure
+            | Generator,
             id,
         ) => return id,
     };
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index ed7c9e7b043ff..92278179a51c9 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -265,9 +265,9 @@ crate fn create_config(
                 // Closures' tables come from their outermost function,
                 // as they are part of the same "inference environment".
                 // This avoids emitting errors for the parent twice (see similar code in `typeck_with_fallback`)
-                let outer_def_id = tcx.closure_base_def_id(def_id.to_def_id()).expect_local();
-                if outer_def_id != def_id {
-                    return tcx.typeck(outer_def_id);
+                let typeck_root_def_id = tcx.typeck_root_def_id(def_id.to_def_id()).expect_local();
+                if typeck_root_def_id != def_id {
+                    return tcx.typeck(typeck_root_def_id);
                 }
 
                 let hir = tcx.hir();
diff --git a/src/librustdoc/formats/item_type.rs b/src/librustdoc/formats/item_type.rs
index 793db16faf385..3979d29b673fd 100644
--- a/src/librustdoc/formats/item_type.rs
+++ b/src/librustdoc/formats/item_type.rs
@@ -134,6 +134,7 @@ impl From<DefKind> for ItemType {
             | DefKind::Use
             | DefKind::ForeignMod
             | DefKind::AnonConst
+            | DefKind::InlineConst
             | DefKind::OpaqueTy
             | DefKind::Field
             | DefKind::LifetimeParam
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 8541e6e18816f..4e5812d7f8429 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -1937,7 +1937,8 @@ fn resolution_failure(
                             | Use
                             | LifetimeParam
                             | Ctor(_, _)
-                            | AnonConst => {
+                            | AnonConst
+                            | InlineConst => {
                                 let note = assoc_item_not_allowed(res);
                                 if let Some(span) = sp {
                                     diag.span_label(span, &note);
diff --git a/src/test/ui/feature-gates/feature-gate-type_changing_struct_update.stderr b/src/test/ui/feature-gates/feature-gate-type_changing_struct_update.stderr
deleted file mode 100644
index 9934fe6816430..0000000000000
--- a/src/test/ui/feature-gates/feature-gate-type_changing_struct_update.stderr
+++ /dev/null
@@ -1,12 +0,0 @@
-error[E0308]: mismatched types
-  --> $DIR/feature-gate-type_changing_struct_update.rs:20:11
-   |
-LL |         ..m1
-   |           ^^ expected struct `State2`, found struct `State1`
-   |
-   = note: expected struct `Machine<State2>`
-              found struct `Machine<State1>`
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/inline-const/const-expr-inference.rs b/src/test/ui/inline-const/const-expr-inference.rs
new file mode 100644
index 0000000000000..6aa2a2f3367fc
--- /dev/null
+++ b/src/test/ui/inline-const/const-expr-inference.rs
@@ -0,0 +1,12 @@
+// check-pass
+
+#![feature(inline_const)]
+#![allow(incomplete_features)]
+
+pub fn todo<T>() -> T {
+    const { todo!() }
+}
+
+fn main() {
+    let _: usize = const { 0 };
+}
diff --git a/src/test/ui/inline-const/const-expr-lifetime-err.rs b/src/test/ui/inline-const/const-expr-lifetime-err.rs
new file mode 100644
index 0000000000000..e56cbc94038a0
--- /dev/null
+++ b/src/test/ui/inline-const/const-expr-lifetime-err.rs
@@ -0,0 +1,30 @@
+#![allow(incomplete_features)]
+#![feature(const_mut_refs)]
+#![feature(inline_const)]
+
+use std::marker::PhantomData;
+
+#[derive(PartialEq, Eq)]
+pub struct InvariantRef<'a, T: ?Sized>(&'a T, PhantomData<&'a mut &'a T>);
+
+impl<'a, T: ?Sized> InvariantRef<'a, T> {
+    pub const fn new(r: &'a T) -> Self {
+        InvariantRef(r, PhantomData)
+    }
+}
+
+impl<'a> InvariantRef<'a, ()> {
+    pub const NEW: Self = InvariantRef::new(&());
+}
+
+fn equate<T>(x: T, y: T){}
+
+fn foo<'a>() {
+    let y = ();
+    equate(InvariantRef::new(&y), const { InvariantRef::<'a>::NEW });
+    //~^ ERROR `y` does not live long enough [E0597]
+}
+
+fn main() {
+    foo();
+}
diff --git a/src/test/ui/inline-const/const-expr-lifetime-err.stderr b/src/test/ui/inline-const/const-expr-lifetime-err.stderr
new file mode 100644
index 0000000000000..30ecd338a856d
--- /dev/null
+++ b/src/test/ui/inline-const/const-expr-lifetime-err.stderr
@@ -0,0 +1,18 @@
+error[E0597]: `y` does not live long enough
+  --> $DIR/const-expr-lifetime-err.rs:24:30
+   |
+LL | fn foo<'a>() {
+   |        -- lifetime `'a` defined here
+LL |     let y = ();
+LL |     equate(InvariantRef::new(&y), const { InvariantRef::<'a>::NEW });
+   |            ------------------^^-
+   |            |                 |
+   |            |                 borrowed value does not live long enough
+   |            argument requires that `y` is borrowed for `'a`
+LL |
+LL | }
+   | - `y` dropped here while still borrowed
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0597`.
diff --git a/src/test/ui/inline-const/const-expr-lifetime.rs b/src/test/ui/inline-const/const-expr-lifetime.rs
new file mode 100644
index 0000000000000..f622f2cbddf48
--- /dev/null
+++ b/src/test/ui/inline-const/const-expr-lifetime.rs
@@ -0,0 +1,36 @@
+// run-pass
+
+#![allow(incomplete_features)]
+#![feature(const_mut_refs)]
+#![feature(inline_const)]
+
+use std::marker::PhantomData;
+
+// rust-lang/rust#78174: ICE: "cannot convert ReErased to a region vid"
+fn issue_78174() {
+    let foo = const { "foo" };
+    assert_eq!(foo, "foo");
+}
+
+pub struct InvariantRef<'a, T: ?Sized>(&'a T, PhantomData<&'a mut &'a T>);
+
+impl<'a, T: ?Sized> InvariantRef<'a, T> {
+    pub const fn new(r: &'a T) -> Self {
+        InvariantRef(r, PhantomData)
+    }
+}
+
+fn get_invariant_ref<'a>() -> InvariantRef<'a, ()> {
+    const { InvariantRef::<'a, ()>::new(&()) }
+}
+
+fn get_invariant_ref2<'a>() -> InvariantRef<'a, ()> {
+    // Try some type inference
+    const { InvariantRef::new(&()) }
+}
+
+fn main() {
+    issue_78174();
+    get_invariant_ref();
+    get_invariant_ref2();
+}
diff --git a/src/test/ui/inline-const/const-match-pat-inference.rs b/src/test/ui/inline-const/const-match-pat-inference.rs
new file mode 100644
index 0000000000000..61188ed5d47bd
--- /dev/null
+++ b/src/test/ui/inline-const/const-match-pat-inference.rs
@@ -0,0 +1,12 @@
+// check-pass
+
+#![feature(inline_const)]
+#![allow(incomplete_features)]
+
+fn main() {
+    match 1u64 {
+        0 => (),
+        const { 0 + 1 } => (),
+        const { 2 - 1 } ..= const { u64::MAX } => (),
+    }
+}
diff --git a/src/test/ui/inline-const/const-match-pat-lifetime-err.rs b/src/test/ui/inline-const/const-match-pat-lifetime-err.rs
new file mode 100644
index 0000000000000..bc5aa24894427
--- /dev/null
+++ b/src/test/ui/inline-const/const-match-pat-lifetime-err.rs
@@ -0,0 +1,34 @@
+// ignore-test
+
+#![allow(incomplete_features)]
+#![feature(const_mut_refs)]
+#![feature(inline_const)]
+
+use std::marker::PhantomData;
+
+#[derive(PartialEq, Eq)]
+pub struct InvariantRef<'a, T: ?Sized>(&'a T, PhantomData<&'a mut &'a T>);
+
+impl<'a, T: ?Sized> InvariantRef<'a, T> {
+    pub const fn new(r: &'a T) -> Self {
+        InvariantRef(r, PhantomData)
+    }
+}
+
+impl<'a> InvariantRef<'a, ()> {
+    pub const NEW: Self = InvariantRef::new(&());
+}
+
+fn match_invariant_ref<'a>() {
+    let y = ();
+    match InvariantRef::new(&y) {
+    //~^ ERROR `y` does not live long enough [E0597]
+        // FIXME(nbdd0121): This should give the same error as `InvariantRef::<'a>::NEW` (without
+        // const block)
+        const { InvariantRef::<'a>::NEW } => (),
+    }
+}
+
+fn main() {
+    match_invariant_ref();
+}
diff --git a/src/test/ui/inline-const/const-match-pat-lifetime.rs b/src/test/ui/inline-const/const-match-pat-lifetime.rs
new file mode 100644
index 0000000000000..3d986f0d9ee08
--- /dev/null
+++ b/src/test/ui/inline-const/const-match-pat-lifetime.rs
@@ -0,0 +1,36 @@
+// run-pass
+
+#![allow(incomplete_features)]
+#![feature(const_mut_refs)]
+#![feature(inline_const)]
+
+use std::marker::PhantomData;
+
+// rust-lang/rust#78174: ICE: "cannot convert ReErased to a region vid"
+fn issue_78174() {
+    match "foo" {
+        const { concat!("fo", "o") } => (),
+        _ => unreachable!(),
+    }
+}
+
+#[derive(PartialEq, Eq)]
+pub struct InvariantRef<'a, T: ?Sized>(&'a T, PhantomData<&'a mut &'a T>);
+
+impl<'a, T: ?Sized> InvariantRef<'a, T> {
+    pub const fn new(r: &'a T) -> Self {
+        InvariantRef(r, PhantomData)
+    }
+}
+
+fn match_invariant_ref<'a>() {
+    match const { InvariantRef::<'a, _>::new(&()) } {
+        const { InvariantRef::<'a, ()>::new(&()) } => {
+        }
+    }
+}
+
+fn main() {
+    issue_78174();
+    match_invariant_ref();
+}
diff --git a/src/test/ui/feature-gates/feature-gate-type_changing_struct_update.rs b/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/feature-gate.rs
similarity index 72%
rename from src/test/ui/feature-gates/feature-gate-type_changing_struct_update.rs
rename to src/test/ui/rfcs/rfc-2528-type-changing-struct-update/feature-gate.rs
index 520c1478f3234..1e8b99ba5647a 100644
--- a/src/test/ui/feature-gates/feature-gate-type_changing_struct_update.rs
+++ b/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/feature-gate.rs
@@ -1,3 +1,5 @@
+// gate-test-type_changing_struct_update
+
 #[derive(Debug)]
 struct Machine<S> {
     state: S,
@@ -17,9 +19,10 @@ fn update_to_state2() {
     };
     let m2: Machine<State2> = Machine {
         state: State2,
-        ..m1 //~ ERROR mismatched types
+        ..m1
+        //~^ ERROR type changing struct updating is experimental [E0658]
+        //~| ERROR mismatched types [E0308]
     };
-    // FIXME: this should trigger feature gate
     assert_eq!(State2, m2.state);
 }
 
diff --git a/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/feature-gate.stderr b/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/feature-gate.stderr
new file mode 100644
index 0000000000000..2217b8c049863
--- /dev/null
+++ b/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/feature-gate.stderr
@@ -0,0 +1,22 @@
+error[E0658]: type changing struct updating is experimental
+  --> $DIR/feature-gate.rs:22:11
+   |
+LL |         ..m1
+   |           ^^
+   |
+   = note: see issue #86555 <https://github.com/rust-lang/rust/issues/86555> for more information
+   = help: add `#![feature(type_changing_struct_update)]` to the crate attributes to enable
+
+error[E0308]: mismatched types
+  --> $DIR/feature-gate.rs:22:11
+   |
+LL |         ..m1
+   |           ^^ expected struct `State2`, found struct `State1`
+   |
+   = note: expected struct `Machine<State2>`
+              found struct `Machine<State1>`
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0308, E0658.
+For more information about an error, try `rustc --explain E0308`.
diff --git a/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/lifetime-update.rs b/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/lifetime-update.rs
new file mode 100644
index 0000000000000..df2fef55dd2d8
--- /dev/null
+++ b/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/lifetime-update.rs
@@ -0,0 +1,43 @@
+#![feature(type_changing_struct_update)]
+#![allow(incomplete_features)]
+
+#[derive(Clone)]
+struct Machine<'a, S> {
+    state: S,
+    lt_str: &'a str,
+    common_field: i32,
+}
+
+#[derive(Clone)]
+struct State1;
+#[derive(Clone)]
+struct State2;
+
+fn update_to_state2() {
+    let s = String::from("hello");
+    let m1: Machine<State1> = Machine {
+        state: State1,
+        lt_str: &s,
+                //~^ ERROR `s` does not live long enough [E0597]
+                // FIXME: The error here actually comes from line 34. The
+                // span of the error message should be corrected to line 34
+        common_field: 2,
+    };
+    // update lifetime
+    let m3: Machine<'static, State1> = Machine {
+        lt_str: "hello, too",
+        ..m1.clone()
+    };
+    // update lifetime and type
+    let m4: Machine<'static, State2> = Machine {
+        state: State2,
+        lt_str: "hello, again",
+        ..m1.clone()
+    };
+    // updating to `static should fail.
+    let m2: Machine<'static, State1> = Machine {
+        ..m1
+    };
+}
+
+fn main() {}
diff --git a/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/lifetime-update.stderr b/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/lifetime-update.stderr
new file mode 100644
index 0000000000000..5f93ad6e0279e
--- /dev/null
+++ b/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/lifetime-update.stderr
@@ -0,0 +1,15 @@
+error[E0597]: `s` does not live long enough
+  --> $DIR/lifetime-update.rs:20:17
+   |
+LL |         lt_str: &s,
+   |                 ^^ borrowed value does not live long enough
+...
+LL |     let m2: Machine<'static, State1> = Machine {
+   |             ------------------------ type annotation requires that `s` is borrowed for `'static`
+...
+LL | }
+   | - `s` dropped here while still borrowed
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0597`.
diff --git a/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/type-generic-update.rs b/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/type-generic-update.rs
new file mode 100644
index 0000000000000..d8b1396a692a7
--- /dev/null
+++ b/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/type-generic-update.rs
@@ -0,0 +1,57 @@
+#![feature(type_changing_struct_update)]
+#![allow(incomplete_features)]
+
+struct Machine<'a, S, M> {
+    state: S,
+    message: M,
+    lt_str: &'a str,
+    common_field: i32,
+}
+
+struct State1;
+struct State2;
+
+struct Message1;
+struct Message2;
+
+fn update() {
+    let m1: Machine<State1, Message1> = Machine {
+        state: State1,
+        message: Message1,
+        lt_str: "hello",
+        common_field: 2,
+    };
+    // single type update
+    let m2: Machine<State2, Message1> = Machine {
+        state: State2,
+        ..m1
+    };
+    // multiple type update
+    let m3: Machine<State2, Message2> = Machine {
+        state: State2,
+        message: Message2,
+        ..m1
+    };
+}
+
+fn fail_update() {
+    let m1: Machine<f64, f64> = Machine {
+        state: 3.2,
+        message: 6.4,
+        lt_str: "hello",
+        common_field: 2,
+    };
+    // single type update fail
+    let m2: Machine<i32, f64> = Machine {
+        ..m1
+        //~^ ERROR mismatched types [E0308]
+    };
+    // multiple type update fail
+    let m3 = Machine::<i32, i32> {
+        ..m1
+        //~^ ERROR mismatched types [E0308]
+        //~| ERROR mismatched types [E0308]
+    };
+}
+
+fn main() {}
diff --git a/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/type-generic-update.stderr b/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/type-generic-update.stderr
new file mode 100644
index 0000000000000..fa8d6ee23d5ec
--- /dev/null
+++ b/src/test/ui/rfcs/rfc-2528-type-changing-struct-update/type-generic-update.stderr
@@ -0,0 +1,30 @@
+error[E0308]: mismatched types
+  --> $DIR/type-generic-update.rs:46:11
+   |
+LL |         ..m1
+   |           ^^ field type mismatch: Machine.state
+   |
+   = note: expected type `i32`
+              found type `f64`
+
+error[E0308]: mismatched types
+  --> $DIR/type-generic-update.rs:51:11
+   |
+LL |         ..m1
+   |           ^^ field type mismatch: Machine.state
+   |
+   = note: expected type `i32`
+              found type `f64`
+
+error[E0308]: mismatched types
+  --> $DIR/type-generic-update.rs:51:11
+   |
+LL |         ..m1
+   |           ^^ field type mismatch: Machine.message
+   |
+   = note: expected type `i32`
+              found type `f64`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/tools/clippy/clippy_lints/src/matches.rs b/src/tools/clippy/clippy_lints/src/matches.rs
index eb311983b2927..7142df98c3f10 100644
--- a/src/tools/clippy/clippy_lints/src/matches.rs
+++ b/src/tools/clippy/clippy_lints/src/matches.rs
@@ -1065,7 +1065,10 @@ fn check_wild_enum_match(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>])
                 PatKind::Path(path) => {
                     #[allow(clippy::match_same_arms)]
                     let id = match cx.qpath_res(path, pat.hir_id) {
-                        Res::Def(DefKind::Const | DefKind::ConstParam | DefKind::AnonConst, _) => return,
+                        Res::Def(
+                            DefKind::Const | DefKind::ConstParam | DefKind::AnonConst | DefKind::InlineConst,
+                            _,
+                        ) => return,
                         Res::Def(_, id) => id,
                         _ => return,
                     };
diff --git a/src/tools/rustdoc-js/tester.js b/src/tools/rustdoc-js/tester.js
index a673e425dfff9..4f73a7f634098 100644
--- a/src/tools/rustdoc-js/tester.js
+++ b/src/tools/rustdoc-js/tester.js
@@ -401,7 +401,8 @@ function showHelp() {
     console.log("  --doc-folder [PATH]        : location of the generated doc folder");
     console.log("  --help                     : show this message then quit");
     console.log("  --crate-name [STRING]      : crate name to be used");
-    console.log("  --test-file [PATH]         : location of the JS test file");
+    console.log("  --test-file [PATHs]        : location of the JS test files (can be called " +
+                "multiple times)");
     console.log("  --test-folder [PATH]       : location of the JS tests folder");
     console.log("  --resource-suffix [STRING] : suffix to refer to the correct files");
 }
@@ -412,7 +413,7 @@ function parseOptions(args) {
         "resource_suffix": "",
         "doc_folder": "",
         "test_folder": "",
-        "test_file": "",
+        "test_file": [],
     };
     var correspondences = {
         "--resource-suffix": "resource_suffix",
@@ -429,7 +430,11 @@ function parseOptions(args) {
                 console.log("Missing argument after `" + args[i - 1] + "` option.");
                 return null;
             }
-            opts[correspondences[args[i - 1]]] = args[i];
+            if (args[i - 1] !== "--test-file") {
+                opts[correspondences[args[i - 1]]] = args[i];
+            } else {
+                opts[correspondences[args[i - 1]]].push(args[i]);
+            }
         } else if (args[i] === "--help") {
             showHelp();
             process.exit(0);
@@ -471,9 +476,10 @@ function main(argv) {
     var errors = 0;
 
     if (opts["test_file"].length !== 0) {
-        errors += checkFile(opts["test_file"], opts, loaded, index);
-    }
-    if (opts["test_folder"].length !== 0) {
+        opts["test_file"].forEach(function(file) {
+            errors += checkFile(file, opts, loaded, index);
+        });
+    } else if (opts["test_folder"].length !== 0) {
         fs.readdirSync(opts["test_folder"]).forEach(function(file) {
             if (!file.endsWith(".js")) {
                 return;