Auto merge of #127403 - compiler-errors:rollup-x2yb5t0, r=compiler-errors

Rollup of 8 pull requests

Successful merges:

 - #123600 (impl PathBuf::add_extension and Path::with_added_extension)
 - #127107 (Improve dead code analysis)
 - #127221 (Improve well known value check-cfg diagnostic for the standard library)
 - #127333 (Split `SolverDelegate` back out from `InferCtxtLike`)
 - #127363 (Improve readability of some fmt code examples)
 - #127366 (Use `ControlFlow` results for visitors that are only looking for a single value)
 - #127368 (Added dots at the sentence ends of rustc AST doc)
 - #127393 (Remove clubby789 from review rotation)

r? `@ghost`
`@rustbot` modify labels: rollup

21 files changed, 400 insertions, 415 deletions

diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
index f2cdedc0087..75c656973f9 100644
--- a/compiler/rustc_ast/src/ast.rs
+++ b/compiler/rustc_ast/src/ast.rs
@@ -176,7 +176,7 @@ pub enum GenericArgs {
     AngleBracketed(AngleBracketedArgs),
     /// The `(A, B)` and `C` in `Foo(A, B) -> C`.
     Parenthesized(ParenthesizedArgs),
-    /// `(..)` in return type notation
+    /// `(..)` in return type notation.
     ParenthesizedElided(Span),
 }
 
@@ -197,11 +197,11 @@ impl GenericArgs {
 /// Concrete argument in the sequence of generic args.
 #[derive(Clone, Encodable, Decodable, Debug)]
 pub enum GenericArg {
-    /// `'a` in `Foo<'a>`
+    /// `'a` in `Foo<'a>`.
     Lifetime(Lifetime),
-    /// `Bar` in `Foo<Bar>`
+    /// `Bar` in `Foo<Bar>`.
     Type(P<Ty>),
-    /// `1` in `Foo<1>`
+    /// `1` in `Foo<1>`.
     Const(AnonConst),
 }
 
@@ -355,7 +355,7 @@ pub enum GenericParamKind {
         ty: P<Ty>,
         /// Span of the `const` keyword.
         kw_span: Span,
-        /// Optional default value for the const generic param
+        /// Optional default value for the const generic param.
         default: Option<AnonConst>,
     },
 }
@@ -833,7 +833,7 @@ pub enum PatKind {
     /// only one rest pattern may occur in the pattern sequences.
     Rest,
 
-    // A never pattern `!`
+    // A never pattern `!`.
     Never,
 
     /// Parentheses in patterns used for grouping (i.e., `(PAT)`).
@@ -1122,9 +1122,9 @@ impl LocalKind {
 #[derive(Clone, Encodable, Decodable, Debug)]
 pub struct Arm {
     pub attrs: AttrVec,
-    /// Match arm pattern, e.g. `10` in `match foo { 10 => {}, _ => {} }`
+    /// Match arm pattern, e.g. `10` in `match foo { 10 => {}, _ => {} }`.
     pub pat: P<Pat>,
-    /// Match arm guard, e.g. `n > 10` in `match foo { n if n > 10 => {}, _ => {} }`
+    /// Match arm guard, e.g. `n > 10` in `match foo { n if n > 10 => {}, _ => {} }`.
     pub guard: Option<P<Expr>>,
     /// Match arm body. Omitted if the pattern is a never pattern.
     pub body: Option<P<Expr>>,
@@ -1355,12 +1355,12 @@ pub struct Closure {
     pub fn_arg_span: Span,
 }
 
-/// Limit types of a range (inclusive or exclusive)
+/// Limit types of a range (inclusive or exclusive).
 #[derive(Copy, Clone, PartialEq, Encodable, Decodable, Debug)]
 pub enum RangeLimits {
-    /// Inclusive at the beginning, exclusive at the end
+    /// Inclusive at the beginning, exclusive at the end.
     HalfOpen,
-    /// Inclusive at the beginning and end
+    /// Inclusive at the beginning and end.
     Closed,
 }
 
@@ -1401,9 +1401,9 @@ pub struct StructExpr {
 pub enum ExprKind {
     /// An array (e.g, `[a, b, c, d]`).
     Array(ThinVec<P<Expr>>),
-    /// Allow anonymous constants from an inline `const` block
+    /// Allow anonymous constants from an inline `const` block.
     ConstBlock(AnonConst),
-    /// A function call
+    /// A function call.
     ///
     /// The first field resolves to the function itself,
     /// and the second field is the list of arguments.
@@ -1457,7 +1457,7 @@ pub enum ExprKind {
     /// A block (`'label: { ... }`).
     Block(P<Block>, Option<Label>),
     /// An `async` block (`async move { ... }`),
-    /// or a `gen` block (`gen move { ... }`)
+    /// or a `gen` block (`gen move { ... }`).
     ///
     /// The span is the "decl", which is the header before the body `{ }`
     /// including the `asyng`/`gen` keywords and possibly `move`.
@@ -2157,9 +2157,9 @@ pub enum TyKind {
     Never,
     /// A tuple (`(A, B, C, D,...)`).
     Tup(ThinVec<P<Ty>>),
-    /// An anonymous struct type i.e. `struct { foo: Type }`
+    /// An anonymous struct type i.e. `struct { foo: Type }`.
     AnonStruct(NodeId, ThinVec<FieldDef>),
-    /// An anonymous union type i.e. `union { bar: Type }`
+    /// An anonymous union type i.e. `union { bar: Type }`.
     AnonUnion(NodeId, ThinVec<FieldDef>),
     /// A path (`module::module::...::Type`), optionally
     /// "qualified", e.g., `<Vec<T> as SomeTrait>::SomeType`.
@@ -2233,9 +2233,9 @@ pub enum TraitObjectSyntax {
 
 #[derive(Clone, Encodable, Decodable, Debug)]
 pub enum PreciseCapturingArg {
-    /// Lifetime parameter
+    /// Lifetime parameter.
     Lifetime(Lifetime),
-    /// Type or const parameter
+    /// Type or const parameter.
     Arg(Path, NodeId),
 }
 
@@ -2529,11 +2529,11 @@ pub enum Safety {
 /// Iterator`.
 #[derive(Copy, Clone, Encodable, Decodable, Debug)]
 pub enum CoroutineKind {
-    /// `async`, which returns an `impl Future`
+    /// `async`, which returns an `impl Future`.
     Async { span: Span, closure_id: NodeId, return_impl_trait_id: NodeId },
-    /// `gen`, which returns an `impl Iterator`
+    /// `gen`, which returns an `impl Iterator`.
     Gen { span: Span, closure_id: NodeId, return_impl_trait_id: NodeId },
-    /// `async gen`, which returns an `impl AsyncIterator`
+    /// `async gen`, which returns an `impl AsyncIterator`.
     AsyncGen { span: Span, closure_id: NodeId, return_impl_trait_id: NodeId },
 }
 
@@ -2750,7 +2750,7 @@ pub struct Variant {
     pub data: VariantData,
     /// Explicit discriminant, e.g., `Foo = 1`.
     pub disr_expr: Option<AnonConst>,
-    /// Is a macro placeholder
+    /// Is a macro placeholder.
     pub is_placeholder: bool,
 }
 
@@ -3024,19 +3024,19 @@ impl Item {
 /// `extern` qualifier on a function item or function type.
 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
 pub enum Extern {
-    /// No explicit extern keyword was used
+    /// No explicit extern keyword was used.
     ///
-    /// E.g. `fn foo() {}`
+    /// E.g. `fn foo() {}`.
     None,
-    /// An explicit extern keyword was used, but with implicit ABI
+    /// An explicit extern keyword was used, but with implicit ABI.
     ///
-    /// E.g. `extern fn foo() {}`
+    /// E.g. `extern fn foo() {}`.
     ///
-    /// This is just `extern "C"` (see `rustc_target::spec::abi::Abi::FALLBACK`)
+    /// This is just `extern "C"` (see `rustc_target::spec::abi::Abi::FALLBACK`).
     Implicit(Span),
-    /// An explicit extern keyword was used with an explicit ABI
+    /// An explicit extern keyword was used with an explicit ABI.
     ///
-    /// E.g. `extern "C" fn foo() {}`
+    /// E.g. `extern "C" fn foo() {}`.
     Explicit(StrLit, Span),
 }
 
@@ -3055,13 +3055,13 @@ impl Extern {
 /// included in this struct (e.g., `async unsafe fn` or `const extern "C" fn`).
 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
 pub struct FnHeader {
-    /// Whether this is `unsafe`, or has a default safety
+    /// Whether this is `unsafe`, or has a default safety.
     pub safety: Safety,
     /// Whether this is `async`, `gen`, or nothing.
     pub coroutine_kind: Option<CoroutineKind>,
     /// The `const` keyword, if any
     pub constness: Const,
-    /// The `extern` keyword and corresponding ABI string, if any
+    /// The `extern` keyword and corresponding ABI string, if any.
     pub ext: Extern,
 }
 
@@ -3255,7 +3255,7 @@ pub enum ItemKind {
     ///
     /// E.g., `trait Foo { .. }`, `trait Foo<T> { .. }` or `auto trait Foo {}`.
     Trait(Box<Trait>),
-    /// Trait alias
+    /// Trait alias.
     ///
     /// E.g., `trait Foo = Bar + Quux;`.
     TraitAlias(Generics, GenericBounds),
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index e291ebd9bb8..c2c3f5bc79e 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -39,6 +39,7 @@ use rustc_trait_selection::traits::error_reporting::suggestions::TypeErrCtxtExt;
 use rustc_trait_selection::traits::error_reporting::FindExprBySpan;
 use rustc_trait_selection::traits::{Obligation, ObligationCause, ObligationCtxt};
 use std::iter;
+use std::ops::ControlFlow;
 
 use crate::borrow_set::TwoPhaseActivation;
 use crate::borrowck_errors;
@@ -784,20 +785,20 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
         /// binding declaration within every scope we inspect.
         struct Finder {
             hir_id: hir::HirId,
-            found: bool,
         }
         impl<'hir> Visitor<'hir> for Finder {
-            fn visit_pat(&mut self, pat: &'hir hir::Pat<'hir>) {
+            type Result = ControlFlow<()>;
+            fn visit_pat(&mut self, pat: &'hir hir::Pat<'hir>) -> Self::Result {
                 if pat.hir_id == self.hir_id {
-                    self.found = true;
+                    return ControlFlow::Break(());
                 }
-                hir::intravisit::walk_pat(self, pat);
+                hir::intravisit::walk_pat(self, pat)
             }
-            fn visit_expr(&mut self, ex: &'hir hir::Expr<'hir>) {
+            fn visit_expr(&mut self, ex: &'hir hir::Expr<'hir>) -> Self::Result {
                 if ex.hir_id == self.hir_id {
-                    self.found = true;
+                    return ControlFlow::Break(());
                 }
-                hir::intravisit::walk_expr(self, ex);
+                hir::intravisit::walk_expr(self, ex)
             }
         }
         // The immediate HIR parent of the moved expression. We'll look for it to be a call.
@@ -822,9 +823,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
                 _ => continue,
             };
             if let Some(&hir_id) = local_hir_id {
-                let mut finder = Finder { hir_id, found: false };
-                finder.visit_expr(e);
-                if finder.found {
+                if (Finder { hir_id }).visit_expr(e).is_break() {
                     // The current scope includes the declaration of the binding we're accessing, we
                     // can't look up any further for loops.
                     break;
@@ -839,9 +838,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
                         hir::Node::Expr(hir::Expr {
                             kind: hir::ExprKind::If(cond, ..), ..
                         }) => {
-                            let mut finder = Finder { hir_id: expr.hir_id, found: false };
-                            finder.visit_expr(cond);
-                            if finder.found {
+                            if (Finder { hir_id: expr.hir_id }).visit_expr(cond).is_break() {
                                 // The expression where the move error happened is in a `while let`
                                 // condition Don't suggest clone as it will likely end in an
                                 // infinite loop.
@@ -1837,7 +1834,6 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
 
         pub struct Holds<'tcx> {
             ty: Ty<'tcx>,
-            holds: bool,
         }
 
         impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for Holds<'tcx> {
@@ -1845,7 +1841,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
 
             fn visit_ty(&mut self, t: Ty<'tcx>) -> Self::Result {
                 if t == self.ty {
-                    self.holds = true;
+                    return ControlFlow::Break(());
                 }
                 t.super_visit_with(self)
             }
@@ -1863,9 +1859,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
                 && rcvr_ty == ty
                 && let ty::Ref(_, inner, _) = rcvr_ty.kind()
                 && let inner = inner.peel_refs()
-                && let mut v = (Holds { ty: inner, holds: false })
-                && let _ = v.visit_ty(local_ty)
-                && v.holds
+                && (Holds { ty: inner }).visit_ty(local_ty).is_break()
                 && let None = self.infcx.type_implements_trait_shallow(clone, inner, self.param_env)
             {
                 err.span_label(
@@ -4325,15 +4319,14 @@ impl<'tcx> AnnotatedBorrowFnSignature<'tcx> {
 }
 
 /// Detect whether one of the provided spans is a statement nested within the top-most visited expr
-struct ReferencedStatementsVisitor<'a>(&'a [Span], bool);
+struct ReferencedStatementsVisitor<'a>(&'a [Span]);
 
-impl<'a, 'v> Visitor<'v> for ReferencedStatementsVisitor<'a> {
-    fn visit_stmt(&mut self, s: &'v hir::Stmt<'v>) {
+impl<'v> Visitor<'v> for ReferencedStatementsVisitor<'_> {
+    type Result = ControlFlow<()>;
+    fn visit_stmt(&mut self, s: &'v hir::Stmt<'v>) -> Self::Result {
         match s.kind {
-            hir::StmtKind::Semi(expr) if self.0.contains(&expr.span) => {
-                self.1 = true;
-            }
-            _ => {}
+            hir::StmtKind::Semi(expr) if self.0.contains(&expr.span) => ControlFlow::Break(()),
+            _ => ControlFlow::Continue(()),
         }
     }
 }
@@ -4375,9 +4368,7 @@ impl<'b, 'v, 'tcx> Visitor<'v> for ConditionVisitor<'b, 'tcx> {
             hir::ExprKind::If(cond, body, None) => {
                 // `if` expressions with no `else` that initialize the binding might be missing an
                 // `else` arm.
-                let mut v = ReferencedStatementsVisitor(self.spans, false);
-                v.visit_expr(body);
-                if v.1 {
+                if ReferencedStatementsVisitor(self.spans).visit_expr(body).is_break() {
                     self.errors.push((
                         cond.span,
                         format!(
@@ -4394,11 +4385,9 @@ impl<'b, 'v, 'tcx> Visitor<'v> for ConditionVisitor<'b, 'tcx> {
             hir::ExprKind::If(cond, body, Some(other)) => {
                 // `if` expressions where the binding is only initialized in one of the two arms
                 // might be missing a binding initialization.
-                let mut a = ReferencedStatementsVisitor(self.spans, false);
-                a.visit_expr(body);
-                let mut b = ReferencedStatementsVisitor(self.spans, false);
-                b.visit_expr(other);
-                match (a.1, b.1) {
+                let a = ReferencedStatementsVisitor(self.spans).visit_expr(body).is_break();
+                let b = ReferencedStatementsVisitor(self.spans).visit_expr(other).is_break();
+                match (a, b) {
                     (true, true) | (false, false) => {}
                     (true, false) => {
                         if other.span.is_desugaring(DesugaringKind::WhileLoop) {
@@ -4437,11 +4426,7 @@ impl<'b, 'v, 'tcx> Visitor<'v> for ConditionVisitor<'b, 'tcx> {
                 // arms might be missing an initialization.
                 let results: Vec<bool> = arms
                     .iter()
-                    .map(|arm| {
-                        let mut v = ReferencedStatementsVisitor(self.spans, false);
-                        v.visit_arm(arm);
-                        v.1
-                    })
+                    .map(|arm| ReferencedStatementsVisitor(self.spans).visit_arm(arm).is_break())
                     .collect();
                 if results.iter().any(|x| *x) && !results.iter().all(|x| *x) {
                     for (arm, seen) in arms.iter().zip(results) {
diff --git a/compiler/rustc_builtin_macros/src/deriving/default.rs b/compiler/rustc_builtin_macros/src/deriving/default.rs
index 577523a1d5a..7a65ed97f00 100644
--- a/compiler/rustc_builtin_macros/src/deriving/default.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/default.rs
@@ -240,7 +240,7 @@ fn has_a_default_variant(item: &Annotatable) -> bool {
             if v.attrs.iter().any(|attr| attr.has_name(kw::Default)) {
                 ControlFlow::Break(())
             } else {
-                // no need to subrecurse.
+                // no need to walk the variant, we are only looking for top level variants
                 ControlFlow::Continue(())
             }
         }
diff --git a/compiler/rustc_hir_analysis/src/collect/generics_of.rs b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
index 9b02c1a61fa..22d465c8e62 100644
--- a/compiler/rustc_hir_analysis/src/collect/generics_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
@@ -1,3 +1,5 @@
+use std::ops::ControlFlow;
+
 use crate::middle::resolve_bound_vars as rbv;
 use hir::{
     intravisit::{self, Visitor},
@@ -87,14 +89,9 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
             let mut in_param_ty = false;
             for (_parent, node) in tcx.hir().parent_iter(hir_id) {
                 if let Some(generics) = node.generics() {
-                    let mut visitor = AnonConstInParamTyDetector {
-                        in_param_ty: false,
-                        found_anon_const_in_param_ty: false,
-                        ct: hir_id,
-                    };
+                    let mut visitor = AnonConstInParamTyDetector { in_param_ty: false, ct: hir_id };
 
-                    visitor.visit_generics(generics);
-                    in_param_ty = visitor.found_anon_const_in_param_ty;
+                    in_param_ty = visitor.visit_generics(generics).is_break();
                     break;
                 }
             }
@@ -460,50 +457,45 @@ fn has_late_bound_regions<'tcx>(tcx: TyCtxt<'tcx>, node: Node<'tcx>) -> Option<S
     struct LateBoundRegionsDetector<'tcx> {
         tcx: TyCtxt<'tcx>,
         outer_index: ty::DebruijnIndex,
-        has_late_bound_regions: Option<Span>,
     }
 
     impl<'tcx> Visitor<'tcx> for LateBoundRegionsDetector<'tcx> {
-        fn visit_ty(&mut self, ty: &'tcx hir::Ty<'tcx>) {
-            if self.has_late_bound_regions.is_some() {
-                return;
-            }
+        type Result = ControlFlow<Span>;
+        fn visit_ty(&mut self, ty: &'tcx hir::Ty<'tcx>) -> ControlFlow<Span> {
             match ty.kind {
                 hir::TyKind::BareFn(..) => {
                     self.outer_index.shift_in(1);
-                    intravisit::walk_ty(self, ty);
+                    let res = intravisit::walk_ty(self, ty);
                     self.outer_index.shift_out(1);
+                    res
                 }
                 _ => intravisit::walk_ty(self, ty),
             }
         }
 
-        fn visit_poly_trait_ref(&mut self, tr: &'tcx hir::PolyTraitRef<'tcx>) {
-            if self.has_late_bound_regions.is_some() {
-                return;
-            }
+        fn visit_poly_trait_ref(&mut self, tr: &'tcx hir::PolyTraitRef<'tcx>) -> ControlFlow<Span> {
             self.outer_index.shift_in(1);
-            intravisit::walk_poly_trait_ref(self, tr);
+            let res = intravisit::walk_poly_trait_ref(self, tr);
             self.outer_index.shift_out(1);
+            res
         }
 
-        fn visit_lifetime(&mut self, lt: &'tcx hir::Lifetime) {
-            if self.has_late_bound_regions.is_some() {
-                return;
-            }
-
+        fn visit_lifetime(&mut self, lt: &'tcx hir::Lifetime) -> ControlFlow<Span> {
             match self.tcx.named_bound_var(lt.hir_id) {
-                Some(rbv::ResolvedArg::StaticLifetime | rbv::ResolvedArg::EarlyBound(..)) => {}
+                Some(rbv::ResolvedArg::StaticLifetime | rbv::ResolvedArg::EarlyBound(..)) => {
+                    ControlFlow::Continue(())
+                }
                 Some(rbv::ResolvedArg::LateBound(debruijn, _, _))
-                    if debruijn < self.outer_index => {}
+                    if debruijn < self.outer_index =>
+                {
+                    ControlFlow::Continue(())
+                }
                 Some(
                     rbv::ResolvedArg::LateBound(..)
                     | rbv::ResolvedArg::Free(..)
                     | rbv::ResolvedArg::Error(_),
                 )
-                | None => {
-                    self.has_late_bound_regions = Some(lt.ident.span);
-                }
+                | None => ControlFlow::Break(lt.ident.span),
             }
         }
     }
@@ -513,11 +505,7 @@ fn has_late_bound_regions<'tcx>(tcx: TyCtxt<'tcx>, node: Node<'tcx>) -> Option<S
         generics: &'tcx hir::Generics<'tcx>,
         decl: &'tcx hir::FnDecl<'tcx>,
     ) -> Option<Span> {
-        let mut visitor = LateBoundRegionsDetector {
-            tcx,
-            outer_index: ty::INNERMOST,
-            has_late_bound_regions: None,
-        };
+        let mut visitor = LateBoundRegionsDetector { tcx, outer_index: ty::INNERMOST };
         for param in generics.params {
             if let GenericParamKind::Lifetime { .. } = param.kind {
                 if tcx.is_late_bound(param.hir_id) {
@@ -525,8 +513,7 @@ fn has_late_bound_regions<'tcx>(tcx: TyCtxt<'tcx>, node: Node<'tcx>) -> Option<S
                 }
             }
         }
-        visitor.visit_fn_decl(decl);
-        visitor.has_late_bound_regions
+        visitor.visit_fn_decl(decl).break_value()
     }
 
     let decl = node.fn_decl()?;
@@ -536,26 +523,29 @@ fn has_late_bound_regions<'tcx>(tcx: TyCtxt<'tcx>, node: Node<'tcx>) -> Option<S
 
 struct AnonConstInParamTyDetector {
     in_param_ty: bool,
-    found_anon_const_in_param_ty: bool,
     ct: HirId,
 }
 
 impl<'v> Visitor<'v> for AnonConstInParamTyDetector {
-    fn visit_generic_param(&mut self, p: &'v hir::GenericParam<'v>) {
+    type Result = ControlFlow<()>;
+
+    fn visit_generic_param(&mut self, p: &'v hir::GenericParam<'v>) -> Self::Result {
         if let GenericParamKind::Const { ty, default: _, is_host_effect: _, synthetic: _ } = p.kind
         {
             let prev = self.in_param_ty;
             self.in_param_ty = true;
-            self.visit_ty(ty);
+            let res = self.visit_ty(ty);
             self.in_param_ty = prev;
+            res
+        } else {
+            ControlFlow::Continue(())
         }
     }
 
-    fn visit_anon_const(&mut self, c: &'v hir::AnonConst) {
+    fn visit_anon_const(&mut self, c: &'v hir::AnonConst) -> Self::Result {
         if self.in_param_ty && self.ct == c.hir_id {
-            self.found_anon_const_in_param_ty = true;
-        } else {
-            intravisit::walk_anon_const(self, c)
+            return ControlFlow::Break(());
         }
+        intravisit::walk_anon_const(self, c)
     }
 }
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/inspect_obligations.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/inspect_obligations.rs
index fab7eb7495c..90dd5f73586 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/inspect_obligations.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/inspect_obligations.rs
@@ -104,8 +104,6 @@ struct NestedObligationsForSelfTy<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> ProofTreeVisitor<'tcx> for NestedObligationsForSelfTy<'a, 'tcx> {
-    type Result = ();
-
     fn span(&self) -> Span {
         self.root_cause.span
     }
diff --git a/compiler/rustc_infer/Cargo.toml b/compiler/rustc_infer/Cargo.toml
index c1565a7d40f..5136ab79a0f 100644
--- a/compiler/rustc_infer/Cargo.toml
+++ b/compiler/rustc_infer/Cargo.toml
@@ -18,6 +18,7 @@ rustc_macros = { path = "../rustc_macros" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
+rustc_type_ir = { path = "../rustc_type_ir" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 tracing = "0.1"
 # tidy-alphabetical-end
diff --git a/compiler/rustc_infer/src/infer/context.rs b/compiler/rustc_infer/src/infer/context.rs
new file mode 100644
index 00000000000..209996b12e2
--- /dev/null
+++ b/compiler/rustc_infer/src/infer/context.rs
@@ -0,0 +1,172 @@
+///! Definition of `InferCtxtLike` from the librarified type layer.
+use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_middle::traits::solve::{Goal, NoSolution, SolverMode};
+use rustc_middle::traits::ObligationCause;
+use rustc_middle::ty::fold::TypeFoldable;
+use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_span::DUMMY_SP;
+use rustc_type_ir::relate::Relate;
+use rustc_type_ir::InferCtxtLike;
+
+use super::{BoundRegionConversionTime, InferCtxt, SubregionOrigin};
+
+impl<'tcx> InferCtxtLike for InferCtxt<'tcx> {
+    type Interner = TyCtxt<'tcx>;
+
+    fn cx(&self) -> TyCtxt<'tcx> {
+        self.tcx
+    }
+
+    fn solver_mode(&self) -> ty::solve::SolverMode {
+        match self.intercrate {
+            true => SolverMode::Coherence,
+            false => SolverMode::Normal,
+        }
+    }
+
+    fn universe(&self) -> ty::UniverseIndex {
+        self.universe()
+    }
+
+    fn create_next_universe(&self) -> ty::UniverseIndex {
+        self.create_next_universe()
+    }
+
+    fn universe_of_ty(&self, vid: ty::TyVid) -> Option<ty::UniverseIndex> {
+        match self.probe_ty_var(vid) {
+            Err(universe) => Some(universe),
+            Ok(_) => None,
+        }
+    }
+
+    fn universe_of_lt(&self, lt: ty::RegionVid) -> Option<ty::UniverseIndex> {
+        match self.inner.borrow_mut().unwrap_region_constraints().probe_value(lt) {
+            Err(universe) => Some(universe),
+            Ok(_) => None,
+        }
+    }
+
+    fn universe_of_ct(&self, ct: ty::ConstVid) -> Option<ty::UniverseIndex> {
+        match self.probe_const_var(ct) {
+            Err(universe) => Some(universe),
+            Ok(_) => None,
+        }
+    }
+
+    fn root_ty_var(&self, var: ty::TyVid) -> ty::TyVid {
+        self.root_var(var)
+    }
+
+    fn root_const_var(&self, var: ty::ConstVid) -> ty::ConstVid {
+        self.root_const_var(var)
+    }
+
+    fn opportunistic_resolve_ty_var(&self, vid: ty::TyVid) -> Ty<'tcx> {
+        match self.probe_ty_var(vid) {
+            Ok(ty) => ty,
+            Err(_) => Ty::new_var(self.tcx, self.root_var(vid)),
+        }
+    }
+
+    fn opportunistic_resolve_int_var(&self, vid: ty::IntVid) -> Ty<'tcx> {
+        self.opportunistic_resolve_int_var(vid)
+    }
+
+    fn opportunistic_resolve_float_var(&self, vid: ty::FloatVid) -> Ty<'tcx> {
+        self.opportunistic_resolve_float_var(vid)
+    }
+
+    fn opportunistic_resolve_ct_var(&self, vid: ty::ConstVid) -> ty::Const<'tcx> {
+        match self.probe_const_var(vid) {
+            Ok(ct) => ct,
+            Err(_) => ty::Const::new_var(self.tcx, self.root_const_var(vid)),
+        }
+    }
+
+    fn opportunistic_resolve_effect_var(&self, vid: ty::EffectVid) -> ty::Const<'tcx> {
+        match self.probe_effect_var(vid) {
+            Some(ct) => ct,
+            None => {
+                ty::Const::new_infer(self.tcx, ty::InferConst::EffectVar(self.root_effect_var(vid)))
+            }
+        }
+    }
+
+    fn opportunistic_resolve_lt_var(&self, vid: ty::RegionVid) -> ty::Region<'tcx> {
+        self.inner.borrow_mut().unwrap_region_constraints().opportunistic_resolve_var(self.tcx, vid)
+    }
+
+    fn defining_opaque_types(&self) -> &'tcx ty::List<LocalDefId> {
+        self.defining_opaque_types()
+    }
+
+    fn next_ty_infer(&self) -> Ty<'tcx> {
+        self.next_ty_var(DUMMY_SP)
+    }
+
+    fn next_const_infer(&self) -> ty::Const<'tcx> {
+        self.next_const_var(DUMMY_SP)
+    }
+
+    fn fresh_args_for_item(&self, def_id: DefId) -> ty::GenericArgsRef<'tcx> {
+        self.fresh_args_for_item(DUMMY_SP, def_id)
+    }
+
+    fn instantiate_binder_with_infer<T: TypeFoldable<TyCtxt<'tcx>> + Copy>(
+        &self,
+        value: ty::Binder<'tcx, T>,
+    ) -> T {
+        self.instantiate_binder_with_fresh_vars(
+            DUMMY_SP,
+            BoundRegionConversionTime::HigherRankedType,
+            value,
+        )
+    }
+
+    fn enter_forall<T: TypeFoldable<TyCtxt<'tcx>> + Copy, U>(
+        &self,
+        value: ty::Binder<'tcx, T>,
+        f: impl FnOnce(T) -> U,
+    ) -> U {
+        self.enter_forall(value, f)
+    }
+
+    fn relate<T: Relate<TyCtxt<'tcx>>>(
+        &self,
+        param_env: ty::ParamEnv<'tcx>,
+        lhs: T,
+        variance: ty::Variance,
+        rhs: T,
+    ) -> Result<Vec<Goal<'tcx, ty::Predicate<'tcx>>>, NoSolution> {
+        self.at(&ObligationCause::dummy(), param_env).relate_no_trace(lhs, variance, rhs)
+    }
+
+    fn eq_structurally_relating_aliases<T: Relate<TyCtxt<'tcx>>>(
+        &self,
+        param_env: ty::ParamEnv<'tcx>,
+        lhs: T,
+        rhs: T,
+    ) -> Result<Vec<Goal<'tcx, ty::Predicate<'tcx>>>, NoSolution> {
+        self.at(&ObligationCause::dummy(), param_env)
+            .eq_structurally_relating_aliases_no_trace(lhs, rhs)
+    }
+
+    fn resolve_vars_if_possible<T>(&self, value: T) -> T
+    where
+        T: TypeFoldable<TyCtxt<'tcx>>,
+    {
+        self.resolve_vars_if_possible(value)
+    }
+
+    fn probe<T>(&self, probe: impl FnOnce() -> T) -> T {
+        self.probe(|_| probe())
+    }
+
+    fn sub_regions(&self, sub: ty::Region<'tcx>, sup: ty::Region<'tcx>) {
+        self.sub_regions(SubregionOrigin::RelateRegionParamBound(DUMMY_SP), sub, sup)
+    }
+
+    fn register_ty_outlives(&self, ty: Ty<'tcx>, r: ty::Region<'tcx>) {
+        self.register_region_obligation_with_cause(ty, r, &ObligationCause::dummy());
+    }
+}
diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index ff593d7ffb7..edbb741036f 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/compiler/rustc_infer/src/infer/mod.rs
@@ -53,6 +53,7 @@ use type_variable::TypeVariableOrigin;
 
 pub mod at;
 pub mod canonical;
+mod context;
 pub mod error_reporting;
 pub mod free_regions;
 mod freshen;
diff --git a/compiler/rustc_lint/src/context/diagnostics/check_cfg.rs b/compiler/rustc_lint/src/context/diagnostics/check_cfg.rs
index c69e680cb64..da36f68fca9 100644
--- a/compiler/rustc_lint/src/context/diagnostics/check_cfg.rs
+++ b/compiler/rustc_lint/src/context/diagnostics/check_cfg.rs
@@ -261,10 +261,16 @@ pub(super) fn unexpected_cfg_value(
         lints::unexpected_cfg_value::CodeSuggestion::RemoveCondition { suggestion, name }
     };
 
-    // We don't want to suggest adding values to well known names
-    // since those are defined by rustc it-self. Users can still
-    // do it if they want, but should not encourage them.
-    let is_cfg_a_well_know_name = sess.psess.check_config.well_known_names.contains(&name);
+    // We don't want to encourage people to add values to a well-known names, as these are
+    // defined by rustc/Rust itself. Users can still do this if they wish, but should not be
+    // encouraged to do so.
+    let can_suggest_adding_value = !sess.psess.check_config.well_known_names.contains(&name)
+        // Except when working on rustc or the standard library itself, in which case we want to
+        // suggest adding these cfgs to the "normal" place because of bootstraping reasons. As a
+        // basic heuristic, we use the "cheat" unstable feature enable method and the
+        // non-ui-testing enabled option.
+        || (matches!(sess.psess.unstable_features, rustc_feature::UnstableFeatures::Cheat)
+            && !sess.opts.unstable_opts.ui_testing);
 
     let inst = |escape_quotes| to_check_cfg_arg(name, value.map(|(v, _s)| v), escape_quotes);
 
@@ -275,14 +281,14 @@ pub(super) fn unexpected_cfg_value(
             } else {
                 Some(lints::unexpected_cfg_value::CargoHelp::DefineFeatures)
             }
-        } else if !is_cfg_a_well_know_name {
+        } else if can_suggest_adding_value {
             Some(lints::unexpected_cfg_value::CargoHelp::Other(cargo_help_sub(sess, &inst)))
         } else {
             None
         };
         lints::unexpected_cfg_value::InvocationHelp::Cargo(help)
     } else {
-        let help = if !is_cfg_a_well_know_name {
+        let help = if can_suggest_adding_value {
             Some(lints::UnexpectedCfgRustcHelp::new(&inst(EscapeQuotes::No)))
         } else {
             None
diff --git a/compiler/rustc_next_trait_solver/src/canonicalizer.rs b/compiler/rustc_next_trait_solver/src/canonicalizer.rs
index 695d02705ab..82488088e30 100644
--- a/compiler/rustc_next_trait_solver/src/canonicalizer.rs
+++ b/compiler/rustc_next_trait_solver/src/canonicalizer.rs
@@ -4,7 +4,8 @@ use rustc_type_ir::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
 use rustc_type_ir::inherent::*;
 use rustc_type_ir::visit::TypeVisitableExt;
 use rustc_type_ir::{
-    self as ty, Canonical, CanonicalTyVarKind, CanonicalVarInfo, CanonicalVarKind, Interner,
+    self as ty, Canonical, CanonicalTyVarKind, CanonicalVarInfo, CanonicalVarKind, InferCtxtLike,
+    Interner,
 };
 
 use crate::delegate::SolverDelegate;
diff --git a/compiler/rustc_next_trait_solver/src/delegate.rs b/compiler/rustc_next_trait_solver/src/delegate.rs
index 6626acfe963..31032dc679a 100644
--- a/compiler/rustc_next_trait_solver/src/delegate.rs
+++ b/compiler/rustc_next_trait_solver/src/delegate.rs
@@ -1,18 +1,20 @@
 use std::fmt::Debug;
+use std::ops::Deref;
 
 use rustc_type_ir::fold::TypeFoldable;
-use rustc_type_ir::relate::Relate;
 use rustc_type_ir::solve::{Certainty, Goal, NoSolution, SolverMode};
-use rustc_type_ir::{self as ty, Interner};
+use rustc_type_ir::{self as ty, InferCtxtLike, Interner};
 
-pub trait SolverDelegate: Sized {
+pub trait SolverDelegate:
+    Deref<Target: InferCtxtLike<Interner = <Self as SolverDelegate>::Interner>> + Sized
+{
     type Interner: Interner;
-    fn cx(&self) -> Self::Interner;
+    fn cx(&self) -> Self::Interner {
+        (**self).cx()
+    }
 
     type Span: Copy;
 
-    fn solver_mode(&self) -> SolverMode;
-
     fn build_with_canonical<V>(
         cx: Self::Interner,
         solver_mode: SolverMode,
@@ -21,82 +23,12 @@ pub trait SolverDelegate: Sized {
     where
         V: TypeFoldable<Self::Interner>;
 
-    fn universe(&self) -> ty::UniverseIndex;
-    fn create_next_universe(&self) -> ty::UniverseIndex;
-
-    fn universe_of_ty(&self, ty: ty::TyVid) -> Option<ty::UniverseIndex>;
-    fn universe_of_lt(&self, lt: ty::RegionVid) -> Option<ty::UniverseIndex>;
-    fn universe_of_ct(&self, ct: ty::ConstVid) -> Option<ty::UniverseIndex>;
-
-    fn root_ty_var(&self, var: ty::TyVid) -> ty::TyVid;
-    fn root_const_var(&self, var: ty::ConstVid) -> ty::ConstVid;
-
-    fn opportunistic_resolve_ty_var(&self, vid: ty::TyVid) -> <Self::Interner as Interner>::Ty;
-    fn opportunistic_resolve_int_var(&self, vid: ty::IntVid) -> <Self::Interner as Interner>::Ty;
-    fn opportunistic_resolve_float_var(
-        &self,
-        vid: ty::FloatVid,
-    ) -> <Self::Interner as Interner>::Ty;
-    fn opportunistic_resolve_ct_var(
-        &self,
-        vid: ty::ConstVid,
-    ) -> <Self::Interner as Interner>::Const;
-    fn opportunistic_resolve_effect_var(
-        &self,
-        vid: ty::EffectVid,
-    ) -> <Self::Interner as Interner>::Const;
-    fn opportunistic_resolve_lt_var(
-        &self,
-        vid: ty::RegionVid,
-    ) -> <Self::Interner as Interner>::Region;
-
-    fn defining_opaque_types(&self) -> <Self::Interner as Interner>::DefiningOpaqueTypes;
-
-    fn next_ty_infer(&self) -> <Self::Interner as Interner>::Ty;
-    fn next_const_infer(&self) -> <Self::Interner as Interner>::Const;
-    fn fresh_args_for_item(
-        &self,
-        def_id: <Self::Interner as Interner>::DefId,
-    ) -> <Self::Interner as Interner>::GenericArgs;
-
     fn fresh_var_for_kind_with_span(
         &self,
         arg: <Self::Interner as Interner>::GenericArg,
         span: Self::Span,
     ) -> <Self::Interner as Interner>::GenericArg;
 
-    fn instantiate_binder_with_infer<T: TypeFoldable<Self::Interner> + Copy>(
-        &self,
-        value: ty::Binder<Self::Interner, T>,
-    ) -> T;
-
-    fn enter_forall<T: TypeFoldable<Self::Interner> + Copy, U>(
-        &self,
-        value: ty::Binder<Self::Interner, T>,
-        f: impl FnOnce(T) -> U,
-    ) -> U;
-
-    fn relate<T: Relate<Self::Interner>>(
-        &self,
-        param_env: <Self::Interner as Interner>::ParamEnv,
-        lhs: T,
-        variance: ty::Variance,
-        rhs: T,
-    ) -> Result<Vec<Goal<Self::Interner, <Self::Interner as Interner>::Predicate>>, NoSolution>;
-
-    fn eq_structurally_relating_aliases<T: Relate<Self::Interner>>(
-        &self,
-        param_env: <Self::Interner as Interner>::ParamEnv,
-        lhs: T,
-        rhs: T,
-    ) -> Result<Vec<Goal<Self::Interner, <Self::Interner as Interner>::Predicate>>, NoSolution>;
-
-    fn resolve_vars_if_possible<T>(&self, value: T) -> T
-    where
-        T: TypeFoldable<Self::Interner>;
-
-    fn probe<T>(&self, probe: impl FnOnce() -> T) -> T;
-
     // FIXME: Uplift the leak check into this crate.
     fn leak_check(&self, max_input_universe: ty::UniverseIndex) -> Result<(), NoSolution>;
 
@@ -112,18 +44,6 @@ pub trait SolverDelegate: Sized {
         unevaluated: ty::UnevaluatedConst<Self::Interner>,
     ) -> Option<<Self::Interner as Interner>::Const>;
 
-    fn sub_regions(
-        &self,
-        sub: <Self::Interner as Interner>::Region,
-        sup: <Self::Interner as Interner>::Region,
-    );
-
-    fn register_ty_outlives(
-        &self,
-        ty: <Self::Interner as Interner>::Ty,
-        r: <Self::Interner as Interner>::Region,
-    );
-
     // FIXME: This only is here because `wf::obligations` is in `rustc_trait_selection`!
     fn well_formed_goals(
         &self,
diff --git a/compiler/rustc_next_trait_solver/src/resolve.rs b/compiler/rustc_next_trait_solver/src/resolve.rs
index 6ed58d0e4fb..254ee514f8b 100644
--- a/compiler/rustc_next_trait_solver/src/resolve.rs
+++ b/compiler/rustc_next_trait_solver/src/resolve.rs
@@ -2,7 +2,7 @@ use crate::delegate::SolverDelegate;
 use rustc_type_ir::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
 use rustc_type_ir::inherent::*;
 use rustc_type_ir::visit::TypeVisitableExt;
-use rustc_type_ir::{self as ty, Interner};
+use rustc_type_ir::{self as ty, InferCtxtLike, Interner};
 
 ///////////////////////////////////////////////////////////////////////////
 // EAGER RESOLUTION
diff --git a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs
index 0a313c6a951..9474d501d6f 100644
--- a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs
@@ -14,7 +14,7 @@ use std::iter;
 use rustc_index::IndexVec;
 use rustc_type_ir::fold::TypeFoldable;
 use rustc_type_ir::inherent::*;
-use rustc_type_ir::{self as ty, Canonical, CanonicalVarValues, Interner};
+use rustc_type_ir::{self as ty, Canonical, CanonicalVarValues, InferCtxtLike, Interner};
 use tracing::{instrument, trace};
 
 use crate::canonicalizer::{CanonicalizeMode, Canonicalizer};
diff --git a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs
index 87342eefb33..d8a3acc655a 100644
--- a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs
@@ -7,7 +7,7 @@ use rustc_type_ir::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
 use rustc_type_ir::inherent::*;
 use rustc_type_ir::relate::Relate;
 use rustc_type_ir::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor};
-use rustc_type_ir::{self as ty, CanonicalVarValues, Interner};
+use rustc_type_ir::{self as ty, CanonicalVarValues, InferCtxtLike, Interner};
 use rustc_type_ir_macros::{Lift_Generic, TypeFoldable_Generic, TypeVisitable_Generic};
 use tracing::{instrument, trace};
 
diff --git a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/probe.rs b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/probe.rs
index e9516c60c70..4258dd9263a 100644
--- a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/probe.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/probe.rs
@@ -1,6 +1,6 @@
 use std::marker::PhantomData;
 
-use rustc_type_ir::Interner;
+use rustc_type_ir::{InferCtxtLike, Interner};
 use tracing::instrument;
 
 use crate::delegate::SolverDelegate;
diff --git a/compiler/rustc_passes/src/dead.rs b/compiler/rustc_passes/src/dead.rs
index 6ea0ed339a6..55514883cb1 100644
--- a/compiler/rustc_passes/src/dead.rs
+++ b/compiler/rustc_passes/src/dead.rs
@@ -277,7 +277,10 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
         pats: &[hir::PatField<'_>],
     ) {
         let variant = match self.typeck_results().node_type(lhs.hir_id).kind() {
-            ty::Adt(adt, _) => adt.variant_of_res(res),
+            ty::Adt(adt, _) => {
+                self.check_def_id(adt.did());
+                adt.variant_of_res(res)
+            }
             _ => span_bug!(lhs.span, "non-ADT in struct pattern"),
         };
         for pat in pats {
@@ -297,7 +300,10 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
         dotdot: hir::DotDotPos,
     ) {
         let variant = match self.typeck_results().node_type(lhs.hir_id).kind() {
-            ty::Adt(adt, _) => adt.variant_of_res(res),
+            ty::Adt(adt, _) => {
+                self.check_def_id(adt.did());
+                adt.variant_of_res(res)
+            }
             _ => {
                 self.tcx.dcx().span_delayed_bug(lhs.span, "non-ADT in tuple struct pattern");
                 return;
@@ -402,31 +408,6 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
                 return false;
             }
 
-            // don't ignore impls for Enums and pub Structs whose methods don't have self receiver,
-            // cause external crate may call such methods to construct values of these types
-            if let Some(local_impl_of) = impl_of.as_local()
-                && let Some(local_def_id) = def_id.as_local()
-                && let Some(fn_sig) =
-                    self.tcx.hir().fn_sig_by_hir_id(self.tcx.local_def_id_to_hir_id(local_def_id))
-                && matches!(fn_sig.decl.implicit_self, hir::ImplicitSelfKind::None)
-                && let TyKind::Path(hir::QPath::Resolved(_, path)) =
-                    self.tcx.hir().expect_item(local_impl_of).expect_impl().self_ty.kind
-                && let Res::Def(def_kind, did) = path.res
-            {
-                match def_kind {
-                    // for example, #[derive(Default)] pub struct T(i32);
-                    // external crate can call T::default() to construct T,
-                    // so that don't ignore impl Default for pub Enum and Structs
-                    DefKind::Struct | DefKind::Union if self.tcx.visibility(did).is_public() => {
-                        return false;
-                    }
-                    // don't ignore impl Default for Enums,
-                    // cause we don't know which variant is constructed
-                    DefKind::Enum => return false,
-                    _ => (),
-                };
-            }
-
             if let Some(trait_of) = self.tcx.trait_id_of_impl(impl_of)
                 && self.tcx.has_attr(trait_of, sym::rustc_trivial_field_reads)
             {
@@ -690,6 +671,9 @@ impl<'tcx> Visitor<'tcx> for MarkSymbolVisitor<'tcx> {
                 self.handle_field_pattern_match(pat, res, fields);
             }
             PatKind::Path(ref qpath) => {
+                if let ty::Adt(adt, _) = self.typeck_results().node_type(pat.hir_id).kind() {
+                    self.check_def_id(adt.did());
+                }
                 let res = self.typeck_results().qpath_res(qpath, pat.hir_id);
                 self.handle_res(res);
             }
@@ -845,7 +829,7 @@ fn check_item<'tcx>(
                 // mark the method live if the self_ty is public,
                 // or the method is public and may construct self
                 if tcx.visibility(local_def_id).is_public()
-                    && (ty_and_all_fields_are_public || may_construct_self)
+                    && (ty_and_all_fields_are_public || (ty_is_public && may_construct_self))
                 {
                     // if the impl item is public,
                     // and the ty may be constructed or can be constructed in foreign crates,
diff --git a/compiler/rustc_trait_selection/src/solve/delegate.rs b/compiler/rustc_trait_selection/src/solve/delegate.rs
index 643d5f80480..f98744e906f 100644
--- a/compiler/rustc_trait_selection/src/solve/delegate.rs
+++ b/compiler/rustc_trait_selection/src/solve/delegate.rs
@@ -1,21 +1,18 @@
 use std::ops::Deref;
 
 use rustc_data_structures::fx::FxHashSet;
-use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::def_id::DefId;
 use rustc_infer::infer::canonical::query_response::make_query_region_constraints;
 use rustc_infer::infer::canonical::{
     Canonical, CanonicalExt as _, CanonicalVarInfo, CanonicalVarValues,
 };
-use rustc_infer::infer::{
-    BoundRegionConversionTime, InferCtxt, RegionVariableOrigin, SubregionOrigin, TyCtxtInferExt,
-};
+use rustc_infer::infer::{InferCtxt, RegionVariableOrigin, TyCtxtInferExt};
 use rustc_infer::traits::solve::Goal;
 use rustc_infer::traits::util::supertraits;
 use rustc_infer::traits::{ObligationCause, Reveal};
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt as _};
 use rustc_span::{ErrorGuaranteed, Span, DUMMY_SP};
-use rustc_type_ir::relate::Relate;
 use rustc_type_ir::solve::{Certainty, NoSolution, SolverMode};
 
 use crate::traits::coherence::trait_ref_is_knowable;
@@ -48,13 +45,6 @@ impl<'tcx> rustc_next_trait_solver::delegate::SolverDelegate for SolverDelegate<
 
     type Span = Span;
 
-    fn solver_mode(&self) -> ty::solve::SolverMode {
-        match self.intercrate {
-            true => SolverMode::Coherence,
-            false => SolverMode::Normal,
-        }
-    }
-
     fn build_with_canonical<V>(
         interner: TyCtxt<'tcx>,
         solver_mode: SolverMode,
@@ -74,104 +64,6 @@ impl<'tcx> rustc_next_trait_solver::delegate::SolverDelegate for SolverDelegate<
         (SolverDelegate(infcx), value, vars)
     }
 
-    fn universe(&self) -> ty::UniverseIndex {
-        self.0.universe()
-    }
-
-    fn create_next_universe(&self) -> ty::UniverseIndex {
-        self.0.create_next_universe()
-    }
-
-    fn universe_of_ty(&self, vid: ty::TyVid) -> Option<ty::UniverseIndex> {
-        // FIXME(BoxyUwU): this is kind of jank and means that printing unresolved
-        // ty infers will give you the universe of the var it resolved to not the universe
-        // it actually had. It also means that if you have a `?0.1` and infer it to `u8` then
-        // try to print out `?0.1` it will just print `?0`.
-        match self.0.probe_ty_var(vid) {
-            Err(universe) => Some(universe),
-            Ok(_) => None,
-        }
-    }
-
-    fn universe_of_lt(&self, lt: ty::RegionVid) -> Option<ty::UniverseIndex> {
-        match self.0.inner.borrow_mut().unwrap_region_constraints().probe_value(lt) {
-            Err(universe) => Some(universe),
-            Ok(_) => None,
-        }
-    }
-
-    fn universe_of_ct(&self, ct: ty::ConstVid) -> Option<ty::UniverseIndex> {
-        // Same issue as with `universe_of_ty`
-        match self.0.probe_const_var(ct) {
-            Err(universe) => Some(universe),
-            Ok(_) => None,
-        }
-    }
-
-    fn root_ty_var(&self, var: ty::TyVid) -> ty::TyVid {
-        self.0.root_var(var)
-    }
-
-    fn root_const_var(&self, var: ty::ConstVid) -> ty::ConstVid {
-        self.0.root_const_var(var)
-    }
-
-    fn opportunistic_resolve_ty_var(&self, vid: ty::TyVid) -> Ty<'tcx> {
-        match self.0.probe_ty_var(vid) {
-            Ok(ty) => ty,
-            Err(_) => Ty::new_var(self.0.tcx, self.0.root_var(vid)),
-        }
-    }
-
-    fn opportunistic_resolve_int_var(&self, vid: ty::IntVid) -> Ty<'tcx> {
-        self.0.opportunistic_resolve_int_var(vid)
-    }
-
-    fn opportunistic_resolve_float_var(&self, vid: ty::FloatVid) -> Ty<'tcx> {
-        self.0.opportunistic_resolve_float_var(vid)
-    }
-
-    fn opportunistic_resolve_ct_var(&self, vid: ty::ConstVid) -> ty::Const<'tcx> {
-        match self.0.probe_const_var(vid) {
-            Ok(ct) => ct,
-            Err(_) => ty::Const::new_var(self.0.tcx, self.0.root_const_var(vid)),
-        }
-    }
-
-    fn opportunistic_resolve_effect_var(&self, vid: ty::EffectVid) -> ty::Const<'tcx> {
-        match self.0.probe_effect_var(vid) {
-            Some(ct) => ct,
-            None => ty::Const::new_infer(
-                self.0.tcx,
-                ty::InferConst::EffectVar(self.0.root_effect_var(vid)),
-            ),
-        }
-    }
-
-    fn opportunistic_resolve_lt_var(&self, vid: ty::RegionVid) -> ty::Region<'tcx> {
-        self.0
-            .inner
-            .borrow_mut()
-            .unwrap_region_constraints()
-            .opportunistic_resolve_var(self.0.tcx, vid)
-    }
-
-    fn defining_opaque_types(&self) -> &'tcx ty::List<LocalDefId> {
-        self.0.defining_opaque_types()
-    }
-
-    fn next_ty_infer(&self) -> Ty<'tcx> {
-        self.0.next_ty_var(DUMMY_SP)
-    }
-
-    fn next_const_infer(&self) -> ty::Const<'tcx> {
-        self.0.next_const_var(DUMMY_SP)
-    }
-
-    fn fresh_args_for_item(&self, def_id: DefId) -> ty::GenericArgsRef<'tcx> {
-        self.0.fresh_args_for_item(DUMMY_SP, def_id)
-    }
-
     fn fresh_var_for_kind_with_span(
         &self,
         arg: ty::GenericArg<'tcx>,
@@ -186,57 +78,6 @@ impl<'tcx> rustc_next_trait_solver::delegate::SolverDelegate for SolverDelegate<
         }
     }
 
-    fn instantiate_binder_with_infer<T: TypeFoldable<TyCtxt<'tcx>> + Copy>(
-        &self,
-        value: ty::Binder<'tcx, T>,
-    ) -> T {
-        self.0.instantiate_binder_with_fresh_vars(
-            DUMMY_SP,
-            BoundRegionConversionTime::HigherRankedType,
-            value,
-        )
-    }
-
-    fn enter_forall<T: TypeFoldable<TyCtxt<'tcx>> + Copy, U>(
-        &self,
-        value: ty::Binder<'tcx, T>,
-        f: impl FnOnce(T) -> U,
-    ) -> U {
-        self.0.enter_forall(value, f)
-    }
-
-    fn relate<T: Relate<TyCtxt<'tcx>>>(
-        &self,
-        param_env: ty::ParamEnv<'tcx>,
-        lhs: T,
-        variance: ty::Variance,
-        rhs: T,
-    ) -> Result<Vec<Goal<'tcx, ty::Predicate<'tcx>>>, NoSolution> {
-        self.0.at(&ObligationCause::dummy(), param_env).relate_no_trace(lhs, variance, rhs)
-    }
-
-    fn eq_structurally_relating_aliases<T: Relate<TyCtxt<'tcx>>>(
-        &self,
-        param_env: ty::ParamEnv<'tcx>,
-        lhs: T,
-        rhs: T,
-    ) -> Result<Vec<Goal<'tcx, ty::Predicate<'tcx>>>, NoSolution> {
-        self.0
-            .at(&ObligationCause::dummy(), param_env)
-            .eq_structurally_relating_aliases_no_trace(lhs, rhs)
-    }
-
-    fn resolve_vars_if_possible<T>(&self, value: T) -> T
-    where
-        T: TypeFoldable<TyCtxt<'tcx>>,
-    {
-        self.0.resolve_vars_if_possible(value)
-    }
-
-    fn probe<T>(&self, probe: impl FnOnce() -> T) -> T {
-        self.0.probe(|_| probe())
-    }
-
     fn leak_check(&self, max_input_universe: ty::UniverseIndex) -> Result<(), NoSolution> {
         self.0.leak_check(max_input_universe, None).map_err(|_| NoSolution)
     }
@@ -265,14 +106,6 @@ impl<'tcx> rustc_next_trait_solver::delegate::SolverDelegate for SolverDelegate<
         }
     }
 
-    fn sub_regions(&self, sub: ty::Region<'tcx>, sup: ty::Region<'tcx>) {
-        self.0.sub_regions(SubregionOrigin::RelateRegionParamBound(DUMMY_SP), sub, sup)
-    }
-
-    fn register_ty_outlives(&self, ty: Ty<'tcx>, r: ty::Region<'tcx>) {
-        self.0.register_region_obligation_with_cause(ty, r, &ObligationCause::dummy());
-    }
-
     fn well_formed_goals(
         &self,
         param_env: ty::ParamEnv<'tcx>,
diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs
index f1611bd049d..5b2c8fb1950 100644
--- a/compiler/rustc_trait_selection/src/traits/object_safety.rs
+++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs
@@ -805,10 +805,11 @@ fn contains_illegal_self_type_reference<'tcx, T: TypeVisitable<TyCtxt<'tcx>>>(
                         .unwrap()
                         .contains(&data.trait_ref(self.tcx).def_id);
 
+                    // only walk contained types if it's not a super trait
                     if is_supertrait_of_current_trait {
-                        ControlFlow::Continue(()) // do not walk contained types, do not report error, do collect $200
+                        ControlFlow::Continue(())
                     } else {
-                        t.super_visit_with(self) // DO walk contained types, POSSIBLY reporting an error
+                        t.super_visit_with(self) // POSSIBLY reporting an error
                     }
                 }
                 _ => t.super_visit_with(self), // walk contained types, if any
diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs
index e3952679f96..f071dc6c784 100644
--- a/compiler/rustc_trait_selection/src/traits/wf.rs
+++ b/compiler/rustc_trait_selection/src/traits/wf.rs
@@ -640,8 +640,6 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> TypeVisitor<TyCtxt<'tcx>> for WfPredicates<'a, 'tcx> {
-    type Result = ();
-
     fn visit_ty(&mut self, t: Ty<'tcx>) -> Self::Result {
         debug!("wf bounds for t={:?} t.kind={:#?}", t, t.kind());
 
diff --git a/compiler/rustc_type_ir/src/infer_ctxt.rs b/compiler/rustc_type_ir/src/infer_ctxt.rs
new file mode 100644
index 00000000000..2c80ee0a73d
--- /dev/null
+++ b/compiler/rustc_type_ir/src/infer_ctxt.rs
@@ -0,0 +1,93 @@
+use crate::fold::TypeFoldable;
+use crate::relate::Relate;
+use crate::solve::{Goal, NoSolution, SolverMode};
+use crate::{self as ty, Interner};
+
+pub trait InferCtxtLike {
+    type Interner: Interner;
+    fn cx(&self) -> Self::Interner;
+
+    fn solver_mode(&self) -> SolverMode;
+
+    fn universe(&self) -> ty::UniverseIndex;
+    fn create_next_universe(&self) -> ty::UniverseIndex;
+
+    fn universe_of_ty(&self, ty: ty::TyVid) -> Option<ty::UniverseIndex>;
+    fn universe_of_lt(&self, lt: ty::RegionVid) -> Option<ty::UniverseIndex>;
+    fn universe_of_ct(&self, ct: ty::ConstVid) -> Option<ty::UniverseIndex>;
+
+    fn root_ty_var(&self, var: ty::TyVid) -> ty::TyVid;
+    fn root_const_var(&self, var: ty::ConstVid) -> ty::ConstVid;
+
+    fn opportunistic_resolve_ty_var(&self, vid: ty::TyVid) -> <Self::Interner as Interner>::Ty;
+    fn opportunistic_resolve_int_var(&self, vid: ty::IntVid) -> <Self::Interner as Interner>::Ty;
+    fn opportunistic_resolve_float_var(
+        &self,
+        vid: ty::FloatVid,
+    ) -> <Self::Interner as Interner>::Ty;
+    fn opportunistic_resolve_ct_var(
+        &self,
+        vid: ty::ConstVid,
+    ) -> <Self::Interner as Interner>::Const;
+    fn opportunistic_resolve_effect_var(
+        &self,
+        vid: ty::EffectVid,
+    ) -> <Self::Interner as Interner>::Const;
+    fn opportunistic_resolve_lt_var(
+        &self,
+        vid: ty::RegionVid,
+    ) -> <Self::Interner as Interner>::Region;
+
+    fn defining_opaque_types(&self) -> <Self::Interner as Interner>::DefiningOpaqueTypes;
+
+    fn next_ty_infer(&self) -> <Self::Interner as Interner>::Ty;
+    fn next_const_infer(&self) -> <Self::Interner as Interner>::Const;
+    fn fresh_args_for_item(
+        &self,
+        def_id: <Self::Interner as Interner>::DefId,
+    ) -> <Self::Interner as Interner>::GenericArgs;
+
+    fn instantiate_binder_with_infer<T: TypeFoldable<Self::Interner> + Copy>(
+        &self,
+        value: ty::Binder<Self::Interner, T>,
+    ) -> T;
+
+    fn enter_forall<T: TypeFoldable<Self::Interner> + Copy, U>(
+        &self,
+        value: ty::Binder<Self::Interner, T>,
+        f: impl FnOnce(T) -> U,
+    ) -> U;
+
+    fn relate<T: Relate<Self::Interner>>(
+        &self,
+        param_env: <Self::Interner as Interner>::ParamEnv,
+        lhs: T,
+        variance: ty::Variance,
+        rhs: T,
+    ) -> Result<Vec<Goal<Self::Interner, <Self::Interner as Interner>::Predicate>>, NoSolution>;
+
+    fn eq_structurally_relating_aliases<T: Relate<Self::Interner>>(
+        &self,
+        param_env: <Self::Interner as Interner>::ParamEnv,
+        lhs: T,
+        rhs: T,
+    ) -> Result<Vec<Goal<Self::Interner, <Self::Interner as Interner>::Predicate>>, NoSolution>;
+
+    fn resolve_vars_if_possible<T>(&self, value: T) -> T
+    where
+        T: TypeFoldable<Self::Interner>;
+
+    fn probe<T>(&self, probe: impl FnOnce() -> T) -> T;
+
+    fn sub_regions(
+        &self,
+        sub: <Self::Interner as Interner>::Region,
+        sup: <Self::Interner as Interner>::Region,
+    );
+
+    fn register_ty_outlives(
+        &self,
+        ty: <Self::Interner as Interner>::Ty,
+        r: <Self::Interner as Interner>::Region,
+    );
+}
diff --git a/compiler/rustc_type_ir/src/lib.rs b/compiler/rustc_type_ir/src/lib.rs
index fedc8959cf7..c57ac74cdfd 100644
--- a/compiler/rustc_type_ir/src/lib.rs
+++ b/compiler/rustc_type_ir/src/lib.rs
@@ -39,6 +39,7 @@ mod const_kind;
 mod effects;
 mod flags;
 mod generic_arg;
+mod infer_ctxt;
 mod interner;
 mod opaque_ty;
 mod predicate;
@@ -56,6 +57,7 @@ pub use const_kind::*;
 pub use effects::*;
 pub use flags::*;
 pub use generic_arg::*;
+pub use infer_ctxt::*;
 pub use interner::*;
 pub use opaque_ty::*;
 pub use predicate::*;