diff --git a/compiler/rustc_type_ir/src/binder.rs b/compiler/rustc_type_ir/src/binder.rs
index 9f2af470d1cd..17b35a2807a2 100644
--- a/compiler/rustc_type_ir/src/binder.rs
+++ b/compiler/rustc_type_ir/src/binder.rs
@@ -49,10 +49,10 @@ impl<I: Interner, U: Interner, T> Lift<U> for Binder<I, T>
 {
     type Lifted = Binder<U, T::Lifted>;
 
-    fn lift_to_interner(self, tcx: U) -> Option<Self::Lifted> {
+    fn lift_to_interner(self, cx: U) -> Option<Self::Lifted> {
         Some(Binder {
-            value: self.value.lift_to_interner(tcx)?,
-            bound_vars: self.bound_vars.lift_to_interner(tcx)?,
+            value: self.value.lift_to_interner(cx)?,
+            bound_vars: self.bound_vars.lift_to_interner(cx)?,
         })
     }
 }
@@ -439,11 +439,11 @@ impl<I: Interner, Iter: IntoIterator> EarlyBinder<I, Iter>
 where
     Iter::Item: TypeFoldable<I>,
 {
-    pub fn iter_instantiated<A>(self, tcx: I, args: A) -> IterInstantiated<I, Iter, A>
+    pub fn iter_instantiated<A>(self, cx: I, args: A) -> IterInstantiated<I, Iter, A>
     where
         A: SliceLike<Item = I::GenericArg>,
     {
-        IterInstantiated { it: self.value.into_iter(), tcx, args }
+        IterInstantiated { it: self.value.into_iter(), cx, args }
     }
 
     /// Similar to [`instantiate_identity`](EarlyBinder::instantiate_identity),
@@ -455,7 +455,7 @@ pub fn iter_identity(self) -> Iter::IntoIter {
 
 pub struct IterInstantiated<I: Interner, Iter: IntoIterator, A> {
     it: Iter::IntoIter,
-    tcx: I,
+    cx: I,
     args: A,
 }
 
@@ -469,7 +469,7 @@ impl<I: Interner, Iter: IntoIterator, A> Iterator for IterInstantiated<I, Iter,
     fn next(&mut self) -> Option<Self::Item> {
         Some(
             EarlyBinder { value: self.it.next()?, _tcx: PhantomData }
-                .instantiate(self.tcx, self.args),
+                .instantiate(self.cx, self.args),
         )
     }
 
@@ -487,7 +487,7 @@ impl<I: Interner, Iter: IntoIterator, A> DoubleEndedIterator for IterInstantiate
     fn next_back(&mut self) -> Option<Self::Item> {
         Some(
             EarlyBinder { value: self.it.next_back()?, _tcx: PhantomData }
-                .instantiate(self.tcx, self.args),
+                .instantiate(self.cx, self.args),
         )
     }
 }
@@ -507,10 +507,10 @@ impl<'s, I: Interner, Iter: IntoIterator> EarlyBinder<I, Iter>
 {
     pub fn iter_instantiated_copied(
         self,
-        tcx: I,
+        cx: I,
         args: &'s [I::GenericArg],
     ) -> IterInstantiatedCopied<'s, I, Iter> {
-        IterInstantiatedCopied { it: self.value.into_iter(), tcx, args }
+        IterInstantiatedCopied { it: self.value.into_iter(), cx, args }
     }
 
     /// Similar to [`instantiate_identity`](EarlyBinder::instantiate_identity),
@@ -522,7 +522,7 @@ pub fn iter_identity_copied(self) -> impl Iterator<Item = <Iter::Item as Deref>:
 
 pub struct IterInstantiatedCopied<'a, I: Interner, Iter: IntoIterator> {
     it: Iter::IntoIter,
-    tcx: I,
+    cx: I,
     args: &'a [I::GenericArg],
 }
 
@@ -535,7 +535,7 @@ impl<I: Interner, Iter: IntoIterator> Iterator for IterInstantiatedCopied<'_, I,
 
     fn next(&mut self) -> Option<Self::Item> {
         self.it.next().map(|value| {
-            EarlyBinder { value: *value, _tcx: PhantomData }.instantiate(self.tcx, self.args)
+            EarlyBinder { value: *value, _tcx: PhantomData }.instantiate(self.cx, self.args)
         })
     }
 
@@ -552,7 +552,7 @@ impl<I: Interner, Iter: IntoIterator> DoubleEndedIterator for IterInstantiatedCo
 {
     fn next_back(&mut self) -> Option<Self::Item> {
         self.it.next_back().map(|value| {
-            EarlyBinder { value: *value, _tcx: PhantomData }.instantiate(self.tcx, self.args)
+            EarlyBinder { value: *value, _tcx: PhantomData }.instantiate(self.cx, self.args)
         })
     }
 }
@@ -589,11 +589,11 @@ fn size_hint(&self) -> (usize, Option<usize>) {
 }
 
 impl<I: Interner, T: TypeFoldable<I>> ty::EarlyBinder<I, T> {
-    pub fn instantiate<A>(self, tcx: I, args: A) -> T
+    pub fn instantiate<A>(self, cx: I, args: A) -> T
     where
         A: SliceLike<Item = I::GenericArg>,
     {
-        let mut folder = ArgFolder { tcx, args: args.as_slice(), binders_passed: 0 };
+        let mut folder = ArgFolder { cx, args: args.as_slice(), binders_passed: 0 };
         self.value.fold_with(&mut folder)
     }
 
@@ -619,7 +619,7 @@ pub fn no_bound_vars(self) -> Option<T> {
 // The actual instantiation engine itself is a type folder.
 
 struct ArgFolder<'a, I: Interner> {
-    tcx: I,
+    cx: I,
     args: &'a [I::GenericArg],
 
     /// Number of region binders we have passed through while doing the instantiation
@@ -629,7 +629,7 @@ struct ArgFolder<'a, I: Interner> {
 impl<'a, I: Interner> TypeFolder<I> for ArgFolder<'a, I> {
     #[inline]
     fn cx(&self) -> I {
-        self.tcx
+        self.cx
     }
 
     fn fold_binder<T: TypeFoldable<I>>(&mut self, t: ty::Binder<I, T>) -> ty::Binder<I, T> {
@@ -858,6 +858,6 @@ fn shift_region_through_binders(&self, region: I::Region) -> I::Region {
         if self.binders_passed == 0 || !region.has_escaping_bound_vars() {
             return region;
         }
-        ty::fold::shift_region(self.tcx, region, self.binders_passed)
+        ty::fold::shift_region(self.cx, region, self.binders_passed)
     }
 }
diff --git a/compiler/rustc_type_ir/src/canonical.rs b/compiler/rustc_type_ir/src/canonical.rs
index 7b114f565f29..a9252711b2b6 100644
--- a/compiler/rustc_type_ir/src/canonical.rs
+++ b/compiler/rustc_type_ir/src/canonical.rs
@@ -330,25 +330,25 @@ pub fn is_identity_modulo_regions(&self) -> bool {
 
     // Given a list of canonical variables, construct a set of values which are
     // the identity response.
-    pub fn make_identity(tcx: I, infos: I::CanonicalVars) -> CanonicalVarValues<I> {
+    pub fn make_identity(cx: I, infos: I::CanonicalVars) -> CanonicalVarValues<I> {
         CanonicalVarValues {
-            var_values: tcx.mk_args_from_iter(infos.iter().enumerate().map(
+            var_values: cx.mk_args_from_iter(infos.iter().enumerate().map(
                 |(i, info)| -> I::GenericArg {
                     match info.kind {
                         CanonicalVarKind::Ty(_) | CanonicalVarKind::PlaceholderTy(_) => {
-                            Ty::new_anon_bound(tcx, ty::INNERMOST, ty::BoundVar::from_usize(i))
+                            Ty::new_anon_bound(cx, ty::INNERMOST, ty::BoundVar::from_usize(i))
                                 .into()
                         }
                         CanonicalVarKind::Region(_) | CanonicalVarKind::PlaceholderRegion(_) => {
-                            Region::new_anon_bound(tcx, ty::INNERMOST, ty::BoundVar::from_usize(i))
+                            Region::new_anon_bound(cx, ty::INNERMOST, ty::BoundVar::from_usize(i))
                                 .into()
                         }
                         CanonicalVarKind::Effect => {
-                            Const::new_anon_bound(tcx, ty::INNERMOST, ty::BoundVar::from_usize(i))
+                            Const::new_anon_bound(cx, ty::INNERMOST, ty::BoundVar::from_usize(i))
                                 .into()
                         }
                         CanonicalVarKind::Const(_) | CanonicalVarKind::PlaceholderConst(_) => {
-                            Const::new_anon_bound(tcx, ty::INNERMOST, ty::BoundVar::from_usize(i))
+                            Const::new_anon_bound(cx, ty::INNERMOST, ty::BoundVar::from_usize(i))
                                 .into()
                         }
                     }
diff --git a/compiler/rustc_type_ir/src/effects.rs b/compiler/rustc_type_ir/src/effects.rs
index f7942f2f982f..d1c3c8e52235 100644
--- a/compiler/rustc_type_ir/src/effects.rs
+++ b/compiler/rustc_type_ir/src/effects.rs
@@ -10,38 +10,38 @@ pub enum EffectKind {
 }
 
 impl EffectKind {
-    pub fn try_from_def_id<I: Interner>(tcx: I, def_id: I::DefId) -> Option<EffectKind> {
-        if tcx.is_lang_item(def_id, EffectsMaybe) {
+    pub fn try_from_def_id<I: Interner>(cx: I, def_id: I::DefId) -> Option<EffectKind> {
+        if cx.is_lang_item(def_id, EffectsMaybe) {
             Some(EffectKind::Maybe)
-        } else if tcx.is_lang_item(def_id, EffectsRuntime) {
+        } else if cx.is_lang_item(def_id, EffectsRuntime) {
             Some(EffectKind::Runtime)
-        } else if tcx.is_lang_item(def_id, EffectsNoRuntime) {
+        } else if cx.is_lang_item(def_id, EffectsNoRuntime) {
             Some(EffectKind::NoRuntime)
         } else {
             None
         }
     }
 
-    pub fn to_def_id<I: Interner>(self, tcx: I) -> I::DefId {
+    pub fn to_def_id<I: Interner>(self, cx: I) -> I::DefId {
         let lang_item = match self {
             EffectKind::Maybe => EffectsMaybe,
             EffectKind::NoRuntime => EffectsNoRuntime,
             EffectKind::Runtime => EffectsRuntime,
         };
 
-        tcx.require_lang_item(lang_item)
+        cx.require_lang_item(lang_item)
     }
 
-    pub fn try_from_ty<I: Interner>(tcx: I, ty: I::Ty) -> Option<EffectKind> {
+    pub fn try_from_ty<I: Interner>(cx: I, ty: I::Ty) -> Option<EffectKind> {
         if let crate::Adt(def, _) = ty.kind() {
-            Self::try_from_def_id(tcx, def.def_id())
+            Self::try_from_def_id(cx, def.def_id())
         } else {
             None
         }
     }
 
-    pub fn to_ty<I: Interner>(self, tcx: I) -> I::Ty {
-        I::Ty::new_adt(tcx, tcx.adt_def(self.to_def_id(tcx)), Default::default())
+    pub fn to_ty<I: Interner>(self, cx: I) -> I::Ty {
+        I::Ty::new_adt(cx, cx.adt_def(self.to_def_id(cx)), Default::default())
     }
 
     /// Returns an intersection between two effect kinds. If one effect kind
diff --git a/compiler/rustc_type_ir/src/elaborate.rs b/compiler/rustc_type_ir/src/elaborate.rs
index 0def7d12f742..7dd2f3de3f82 100644
--- a/compiler/rustc_type_ir/src/elaborate.rs
+++ b/compiler/rustc_type_ir/src/elaborate.rs
@@ -258,17 +258,17 @@ pub fn supertrait_def_ids<I: Interner>(
 }
 
 pub fn supertraits<I: Interner>(
-    tcx: I,
+    cx: I,
     trait_ref: ty::Binder<I, ty::TraitRef<I>>,
 ) -> FilterToTraits<I, Elaborator<I, I::Clause>> {
-    elaborate(tcx, [trait_ref.upcast(tcx)]).filter_only_self().filter_to_traits()
+    elaborate(cx, [trait_ref.upcast(cx)]).filter_only_self().filter_to_traits()
 }
 
 pub fn transitive_bounds<I: Interner>(
-    tcx: I,
+    cx: I,
     trait_refs: impl Iterator<Item = ty::Binder<I, ty::TraitRef<I>>>,
 ) -> FilterToTraits<I, Elaborator<I, I::Clause>> {
-    elaborate(tcx, trait_refs.map(|trait_ref| trait_ref.upcast(tcx)))
+    elaborate(cx, trait_refs.map(|trait_ref| trait_ref.upcast(cx)))
         .filter_only_self()
         .filter_to_traits()
 }
diff --git a/compiler/rustc_type_ir/src/fast_reject.rs b/compiler/rustc_type_ir/src/fast_reject.rs
index 0810fa5c5583..456accd1a1b7 100644
--- a/compiler/rustc_type_ir/src/fast_reject.rs
+++ b/compiler/rustc_type_ir/src/fast_reject.rs
@@ -105,7 +105,7 @@ pub enum TreatParams {
 ///
 /// ¹ meaning that if the outermost layers are different, then the whole types are also different.
 pub fn simplify_type<I: Interner>(
-    tcx: I,
+    cx: I,
     ty: I::Ty,
     treat_params: TreatParams,
 ) -> Option<SimplifiedType<I::DefId>> {
@@ -119,10 +119,10 @@ pub fn simplify_type<I: Interner>(
         ty::Str => Some(SimplifiedType::Str),
         ty::Array(..) => Some(SimplifiedType::Array),
         ty::Slice(..) => Some(SimplifiedType::Slice),
-        ty::Pat(ty, ..) => simplify_type(tcx, ty, treat_params),
+        ty::Pat(ty, ..) => simplify_type(cx, ty, treat_params),
         ty::RawPtr(_, mutbl) => Some(SimplifiedType::Ptr(mutbl)),
         ty::Dynamic(trait_info, ..) => match trait_info.principal_def_id() {
-            Some(principal_def_id) if !tcx.trait_is_auto(principal_def_id) => {
+            Some(principal_def_id) if !cx.trait_is_auto(principal_def_id) => {
                 Some(SimplifiedType::Trait(principal_def_id))
             }
             _ => Some(SimplifiedType::MarkerTraitObject),
diff --git a/compiler/rustc_type_ir/src/fold.rs b/compiler/rustc_type_ir/src/fold.rs
index 09ee12d1cc39..a4d8dafb246e 100644
--- a/compiler/rustc_type_ir/src/fold.rs
+++ b/compiler/rustc_type_ir/src/fold.rs
@@ -345,20 +345,20 @@ fn try_fold_with<F: FallibleTypeFolder<I>>(self, folder: &mut F) -> Result<Self,
 // `rustc_middle/src/ty/generic_args.rs` for more details.
 
 struct Shifter<I: Interner> {
-    tcx: I,
+    cx: I,
     current_index: ty::DebruijnIndex,
     amount: u32,
 }
 
 impl<I: Interner> Shifter<I> {
-    pub fn new(tcx: I, amount: u32) -> Self {
-        Shifter { tcx, current_index: ty::INNERMOST, amount }
+    pub fn new(cx: I, amount: u32) -> Self {
+        Shifter { cx, current_index: ty::INNERMOST, amount }
     }
 }
 
 impl<I: Interner> TypeFolder<I> for Shifter<I> {
     fn cx(&self) -> I {
-        self.tcx
+        self.cx
     }
 
     fn fold_binder<T: TypeFoldable<I>>(&mut self, t: ty::Binder<I, T>) -> ty::Binder<I, T> {
@@ -372,7 +372,7 @@ fn fold_region(&mut self, r: I::Region) -> I::Region {
         match r.kind() {
             ty::ReBound(debruijn, br) if debruijn >= self.current_index => {
                 let debruijn = debruijn.shifted_in(self.amount);
-                Region::new_bound(self.tcx, debruijn, br)
+                Region::new_bound(self.cx, debruijn, br)
             }
             _ => r,
         }
@@ -382,7 +382,7 @@ fn fold_ty(&mut self, ty: I::Ty) -> I::Ty {
         match ty.kind() {
             ty::Bound(debruijn, bound_ty) if debruijn >= self.current_index => {
                 let debruijn = debruijn.shifted_in(self.amount);
-                Ty::new_bound(self.tcx, debruijn, bound_ty)
+                Ty::new_bound(self.cx, debruijn, bound_ty)
             }
 
             _ if ty.has_vars_bound_at_or_above(self.current_index) => ty.super_fold_with(self),
@@ -394,7 +394,7 @@ fn fold_const(&mut self, ct: I::Const) -> I::Const {
         match ct.kind() {
             ty::ConstKind::Bound(debruijn, bound_ct) if debruijn >= self.current_index => {
                 let debruijn = debruijn.shifted_in(self.amount);
-                Const::new_bound(self.tcx, debruijn, bound_ct)
+                Const::new_bound(self.cx, debruijn, bound_ct)
             }
             _ => ct.super_fold_with(self),
         }
@@ -405,16 +405,16 @@ fn fold_predicate(&mut self, p: I::Predicate) -> I::Predicate {
     }
 }
 
-pub fn shift_region<I: Interner>(tcx: I, region: I::Region, amount: u32) -> I::Region {
+pub fn shift_region<I: Interner>(cx: I, region: I::Region, amount: u32) -> I::Region {
     match region.kind() {
         ty::ReBound(debruijn, br) if amount > 0 => {
-            Region::new_bound(tcx, debruijn.shifted_in(amount), br)
+            Region::new_bound(cx, debruijn.shifted_in(amount), br)
         }
         _ => region,
     }
 }
 
-pub fn shift_vars<I: Interner, T>(tcx: I, value: T, amount: u32) -> T
+pub fn shift_vars<I: Interner, T>(cx: I, value: T, amount: u32) -> T
 where
     T: TypeFoldable<I>,
 {
@@ -424,5 +424,5 @@ pub fn shift_vars<I: Interner, T>(tcx: I, value: T, amount: u32) -> T
         return value;
     }
 
-    value.fold_with(&mut Shifter::new(tcx, amount))
+    value.fold_with(&mut Shifter::new(cx, amount))
 }
diff --git a/compiler/rustc_type_ir/src/inherent.rs b/compiler/rustc_type_ir/src/inherent.rs
index f05d626b4703..63ad36efc852 100644
--- a/compiler/rustc_type_ir/src/inherent.rs
+++ b/compiler/rustc_type_ir/src/inherent.rs
@@ -475,7 +475,7 @@ fn as_projection_clause(self) -> Option<ty::Binder<I, ty::ProjectionPredicate<I>
     /// poly-trait-ref to supertraits that must hold if that
     /// poly-trait-ref holds. This is slightly different from a normal
     /// instantiation in terms of what happens with bound regions.
-    fn instantiate_supertrait(self, tcx: I, trait_ref: ty::Binder<I, ty::TraitRef<I>>) -> Self;
+    fn instantiate_supertrait(self, cx: I, trait_ref: ty::Binder<I, ty::TraitRef<I>>) -> Self;
 }
 
 /// Common capabilities of placeholder kinds
diff --git a/compiler/rustc_type_ir/src/lift.rs b/compiler/rustc_type_ir/src/lift.rs
index abad155c9ae0..e5a099d1f504 100644
--- a/compiler/rustc_type_ir/src/lift.rs
+++ b/compiler/rustc_type_ir/src/lift.rs
@@ -17,5 +17,5 @@
 /// e.g., `()` or `u8`, was interned in a different context.
 pub trait Lift<I>: std::fmt::Debug {
     type Lifted: std::fmt::Debug;
-    fn lift_to_interner(self, tcx: I) -> Option<Self::Lifted>;
+    fn lift_to_interner(self, cx: I) -> Option<Self::Lifted>;
 }
diff --git a/compiler/rustc_type_ir/src/opaque_ty.rs b/compiler/rustc_type_ir/src/opaque_ty.rs
index d8ed4770e2dc..e5d18fcb3d1e 100644
--- a/compiler/rustc_type_ir/src/opaque_ty.rs
+++ b/compiler/rustc_type_ir/src/opaque_ty.rs
@@ -22,8 +22,8 @@ pub struct OpaqueTypeKey<I: Interner> {
 }
 
 impl<I: Interner> OpaqueTypeKey<I> {
-    pub fn iter_captured_args(self, tcx: I) -> impl Iterator<Item = (usize, I::GenericArg)> {
-        let variances = tcx.variances_of(self.def_id.into());
+    pub fn iter_captured_args(self, cx: I) -> impl Iterator<Item = (usize, I::GenericArg)> {
+        let variances = cx.variances_of(self.def_id.into());
         std::iter::zip(self.args.iter(), variances.iter()).enumerate().filter_map(
             |(i, (arg, v))| match (arg.kind(), v) {
                 (_, ty::Invariant) => Some((i, arg)),
@@ -35,18 +35,18 @@ pub fn iter_captured_args(self, tcx: I) -> impl Iterator<Item = (usize, I::Gener
 
     pub fn fold_captured_lifetime_args(
         self,
-        tcx: I,
+        cx: I,
         mut f: impl FnMut(I::Region) -> I::Region,
     ) -> Self {
         let Self { def_id, args } = self;
-        let variances = tcx.variances_of(def_id.into());
+        let variances = cx.variances_of(def_id.into());
         let args =
             std::iter::zip(args.iter(), variances.iter()).map(|(arg, v)| match (arg.kind(), v) {
                 (ty::GenericArgKind::Lifetime(_), ty::Bivariant) => arg,
                 (ty::GenericArgKind::Lifetime(lt), _) => f(lt).into(),
                 _ => arg,
             });
-        let args = tcx.mk_args_from_iter(args);
+        let args = cx.mk_args_from_iter(args);
         Self { def_id, args }
     }
 }
diff --git a/compiler/rustc_type_ir/src/outlives.rs b/compiler/rustc_type_ir/src/outlives.rs
index 10b6f3355d92..eb84f3dd5873 100644
--- a/compiler/rustc_type_ir/src/outlives.rs
+++ b/compiler/rustc_type_ir/src/outlives.rs
@@ -54,15 +54,15 @@ pub enum Component<I: Interner> {
 /// Push onto `out` all the things that must outlive `'a` for the condition
 /// `ty0: 'a` to hold. Note that `ty0` must be a **fully resolved type**.
 pub fn push_outlives_components<I: Interner>(
-    tcx: I,
+    cx: I,
     ty: I::Ty,
     out: &mut SmallVec<[Component<I>; 4]>,
 ) {
-    ty.visit_with(&mut OutlivesCollector { tcx, out, visited: Default::default() });
+    ty.visit_with(&mut OutlivesCollector { cx, out, visited: Default::default() });
 }
 
 struct OutlivesCollector<'a, I: Interner> {
-    tcx: I,
+    cx: I,
     out: &'a mut SmallVec<[Component<I>; 4]>,
     visited: SsoHashSet<I::Ty>,
 }
@@ -147,7 +147,7 @@ fn visit_ty(&mut self, ty: I::Ty) -> Self::Result {
                     // OutlivesProjectionComponents. Continue walking
                     // through and constrain Pi.
                     let mut subcomponents = smallvec![];
-                    compute_alias_components_recursive(self.tcx, ty, &mut subcomponents);
+                    compute_alias_components_recursive(self.cx, ty, &mut subcomponents);
                     self.out.push(Component::EscapingAlias(subcomponents.into_iter().collect()));
                 }
             }
@@ -206,7 +206,7 @@ fn visit_region(&mut self, lt: I::Region) -> Self::Result {
 /// This should not be used to get the components of `parent` itself.
 /// Use [push_outlives_components] instead.
 pub fn compute_alias_components_recursive<I: Interner>(
-    tcx: I,
+    cx: I,
     alias_ty: I::Ty,
     out: &mut SmallVec<[Component<I>; 4]>,
 ) {
@@ -215,9 +215,9 @@ pub fn compute_alias_components_recursive<I: Interner>(
     };
 
     let opt_variances =
-        if kind == ty::Opaque { Some(tcx.variances_of(alias_ty.def_id)) } else { None };
+        if kind == ty::Opaque { Some(cx.variances_of(alias_ty.def_id)) } else { None };
 
-    let mut visitor = OutlivesCollector { tcx, out, visited: Default::default() };
+    let mut visitor = OutlivesCollector { cx, out, visited: Default::default() };
 
     for (index, child) in alias_ty.args.iter().enumerate() {
         if opt_variances.and_then(|variances| variances.get(index)) == Some(ty::Bivariant) {
diff --git a/compiler/rustc_type_ir/src/predicate.rs b/compiler/rustc_type_ir/src/predicate.rs
index acf8817c6ac1..e03f521c5b10 100644
--- a/compiler/rustc_type_ir/src/predicate.rs
+++ b/compiler/rustc_type_ir/src/predicate.rs
@@ -34,8 +34,8 @@ impl<I: Interner, U: Interner, A> Lift<U> for OutlivesPredicate<I, A>
 {
     type Lifted = OutlivesPredicate<U, A::Lifted>;
 
-    fn lift_to_interner(self, tcx: U) -> Option<Self::Lifted> {
-        Some(OutlivesPredicate(self.0.lift_to_interner(tcx)?, self.1.lift_to_interner(tcx)?))
+    fn lift_to_interner(self, cx: U) -> Option<Self::Lifted> {
+        Some(OutlivesPredicate(self.0.lift_to_interner(cx)?, self.1.lift_to_interner(cx)?))
     }
 }
 
@@ -267,25 +267,23 @@ impl<I: Interner> ty::Binder<I, ExistentialPredicate<I>> {
     /// Given an existential predicate like `?Self: PartialEq<u32>` (e.g., derived from `dyn PartialEq<u32>`),
     /// and a concrete type `self_ty`, returns a full predicate where the existentially quantified variable `?Self`
     /// has been replaced with `self_ty` (e.g., `self_ty: PartialEq<u32>`, in our example).
-    pub fn with_self_ty(&self, tcx: I, self_ty: I::Ty) -> I::Clause {
+    pub fn with_self_ty(&self, cx: I, self_ty: I::Ty) -> I::Clause {
         match self.skip_binder() {
-            ExistentialPredicate::Trait(tr) => {
-                self.rebind(tr).with_self_ty(tcx, self_ty).upcast(tcx)
-            }
+            ExistentialPredicate::Trait(tr) => self.rebind(tr).with_self_ty(cx, self_ty).upcast(cx),
             ExistentialPredicate::Projection(p) => {
-                self.rebind(p.with_self_ty(tcx, self_ty)).upcast(tcx)
+                self.rebind(p.with_self_ty(cx, self_ty)).upcast(cx)
             }
             ExistentialPredicate::AutoTrait(did) => {
-                let generics = tcx.generics_of(did);
+                let generics = cx.generics_of(did);
                 let trait_ref = if generics.count() == 1 {
-                    ty::TraitRef::new(tcx, did, [self_ty])
+                    ty::TraitRef::new(cx, did, [self_ty])
                 } else {
                     // If this is an ill-formed auto trait, then synthesize
                     // new error args for the missing generics.
-                    let err_args = GenericArgs::extend_with_error(tcx, did, &[self_ty.into()]);
-                    ty::TraitRef::new_from_args(tcx, did, err_args)
+                    let err_args = GenericArgs::extend_with_error(cx, did, &[self_ty.into()]);
+                    ty::TraitRef::new_from_args(cx, did, err_args)
                 };
-                self.rebind(trait_ref).upcast(tcx)
+                self.rebind(trait_ref).upcast(cx)
             }
         }
     }
@@ -345,8 +343,8 @@ pub fn def_id(&self) -> I::DefId {
     /// we convert the principal trait-ref into a normal trait-ref,
     /// you must give *some* self type. A common choice is `mk_err()`
     /// or some placeholder type.
-    pub fn with_self_ty(&self, tcx: I, self_ty: I::Ty) -> ty::Binder<I, TraitRef<I>> {
-        self.map_bound(|trait_ref| trait_ref.with_self_ty(tcx, self_ty))
+    pub fn with_self_ty(&self, cx: I, self_ty: I::Ty) -> ty::Binder<I, TraitRef<I>> {
+        self.map_bound(|trait_ref| trait_ref.with_self_ty(cx, self_ty))
     }
 }
 
@@ -406,8 +404,8 @@ pub fn erase_self_ty(interner: I, projection_predicate: ProjectionPredicate<I>)
 }
 
 impl<I: Interner> ty::Binder<I, ExistentialProjection<I>> {
-    pub fn with_self_ty(&self, tcx: I, self_ty: I::Ty) -> ty::Binder<I, ProjectionPredicate<I>> {
-        self.map_bound(|p| p.with_self_ty(tcx, self_ty))
+    pub fn with_self_ty(&self, cx: I, self_ty: I::Ty) -> ty::Binder<I, ProjectionPredicate<I>> {
+        self.map_bound(|p| p.with_self_ty(cx, self_ty))
     }
 
     pub fn item_def_id(&self) -> I::DefId {
@@ -669,21 +667,21 @@ pub fn def_id(self) -> I::DefId {
 impl<I: Interner> ty::Binder<I, ProjectionPredicate<I>> {
     /// Returns the `DefId` of the trait of the associated item being projected.
     #[inline]
-    pub fn trait_def_id(&self, tcx: I) -> I::DefId {
-        self.skip_binder().projection_term.trait_def_id(tcx)
+    pub fn trait_def_id(&self, cx: I) -> I::DefId {
+        self.skip_binder().projection_term.trait_def_id(cx)
     }
 
     /// Get the trait ref required for this projection to be well formed.
     /// Note that for generic associated types the predicates of the associated
     /// type also need to be checked.
     #[inline]
-    pub fn required_poly_trait_ref(&self, tcx: I) -> ty::Binder<I, TraitRef<I>> {
+    pub fn required_poly_trait_ref(&self, cx: I) -> ty::Binder<I, TraitRef<I>> {
         // Note: unlike with `TraitRef::to_poly_trait_ref()`,
         // `self.0.trait_ref` is permitted to have escaping regions.
         // This is because here `self` has a `Binder` and so does our
         // return value, so we are preserving the number of binding
         // levels.
-        self.map_bound(|predicate| predicate.projection_term.trait_ref(tcx))
+        self.map_bound(|predicate| predicate.projection_term.trait_ref(cx))
     }
 
     pub fn term(&self) -> ty::Binder<I, I::Term> {
diff --git a/compiler/rustc_type_ir/src/relate.rs b/compiler/rustc_type_ir/src/relate.rs
index 0439e7f857fe..a8f48d14af5c 100644
--- a/compiler/rustc_type_ir/src/relate.rs
+++ b/compiler/rustc_type_ir/src/relate.rs
@@ -56,7 +56,7 @@ pub fn xform(self, other: VarianceDiagInfo<I>) -> VarianceDiagInfo<I> {
 }
 
 pub trait TypeRelation<I: Interner>: Sized {
-    fn tcx(&self) -> I;
+    fn cx(&self) -> I;
 
     /// Returns a static string we can use for printouts.
     fn tag(&self) -> &'static str;
@@ -80,8 +80,8 @@ fn relate_item_args(
             item_def_id, a_arg, b_arg
         );
 
-        let tcx = self.tcx();
-        let opt_variances = tcx.variances_of(item_def_id);
+        let cx = self.cx();
+        let opt_variances = cx.variances_of(item_def_id);
         relate_args_with_variances(self, item_def_id, opt_variances, a_arg, b_arg, true)
     }
 
@@ -128,7 +128,7 @@ pub fn relate_args_invariantly<I: Interner, R: TypeRelation<I>>(
     a_arg: I::GenericArgs,
     b_arg: I::GenericArgs,
 ) -> RelateResult<I, I::GenericArgs> {
-    relation.tcx().mk_args_from_iter(iter::zip(a_arg.iter(), b_arg.iter()).map(|(a, b)| {
+    relation.cx().mk_args_from_iter(iter::zip(a_arg.iter(), b_arg.iter()).map(|(a, b)| {
         relation.relate_with_variance(ty::Invariant, VarianceDiagInfo::default(), a, b)
     }))
 }
@@ -141,14 +141,13 @@ pub fn relate_args_with_variances<I: Interner, R: TypeRelation<I>>(
     b_arg: I::GenericArgs,
     fetch_ty_for_diag: bool,
 ) -> RelateResult<I, I::GenericArgs> {
-    let tcx = relation.tcx();
+    let cx = relation.cx();
 
     let mut cached_ty = None;
     let params = iter::zip(a_arg.iter(), b_arg.iter()).enumerate().map(|(i, (a, b))| {
         let variance = variances.get(i).unwrap();
         let variance_info = if variance == ty::Invariant && fetch_ty_for_diag {
-            let ty =
-                *cached_ty.get_or_insert_with(|| tcx.type_of(ty_def_id).instantiate(tcx, a_arg));
+            let ty = *cached_ty.get_or_insert_with(|| cx.type_of(ty_def_id).instantiate(cx, a_arg));
             VarianceDiagInfo::Invariant { ty, param_index: i.try_into().unwrap() }
         } else {
             VarianceDiagInfo::default()
@@ -156,7 +155,7 @@ pub fn relate_args_with_variances<I: Interner, R: TypeRelation<I>>(
         relation.relate_with_variance(variance, variance_info, a, b)
     });
 
-    tcx.mk_args_from_iter(params)
+    cx.mk_args_from_iter(params)
 }
 
 impl<I: Interner> Relate<I> for ty::FnSig<I> {
@@ -165,7 +164,7 @@ fn relate<R: TypeRelation<I>>(
         a: ty::FnSig<I>,
         b: ty::FnSig<I>,
     ) -> RelateResult<I, ty::FnSig<I>> {
-        let tcx = relation.tcx();
+        let cx = relation.cx();
 
         if a.c_variadic != b.c_variadic {
             return Err(TypeError::VariadicMismatch({
@@ -210,7 +209,7 @@ fn relate<R: TypeRelation<I>>(
                 r => r,
             });
         Ok(ty::FnSig {
-            inputs_and_output: tcx.mk_type_list_from_iter(inputs_and_output)?,
+            inputs_and_output: cx.mk_type_list_from_iter(inputs_and_output)?,
             c_variadic: a.c_variadic,
             safety,
             abi,
@@ -245,11 +244,11 @@ fn relate<R: TypeRelation<I>>(
                 ExpectedFound::new(true, a, b)
             }))
         } else {
-            let args = match a.kind(relation.tcx()) {
+            let args = match a.kind(relation.cx()) {
                 ty::Opaque => relate_args_with_variances(
                     relation,
                     a.def_id,
-                    relation.tcx().variances_of(a.def_id),
+                    relation.cx().variances_of(a.def_id),
                     a.args,
                     b.args,
                     false, // do not fetch `type_of(a_def_id)`, as it will cause a cycle
@@ -258,7 +257,7 @@ fn relate<R: TypeRelation<I>>(
                     relate_args_invariantly(relation, a.args, b.args)?
                 }
             };
-            Ok(ty::AliasTy::new_from_args(relation.tcx(), a.def_id, args))
+            Ok(ty::AliasTy::new_from_args(relation.cx(), a.def_id, args))
         }
     }
 }
@@ -276,11 +275,11 @@ fn relate<R: TypeRelation<I>>(
                 ExpectedFound::new(true, a, b)
             }))
         } else {
-            let args = match a.kind(relation.tcx()) {
+            let args = match a.kind(relation.cx()) {
                 ty::AliasTermKind::OpaqueTy => relate_args_with_variances(
                     relation,
                     a.def_id,
-                    relation.tcx().variances_of(a.def_id),
+                    relation.cx().variances_of(a.def_id),
                     a.args,
                     b.args,
                     false, // do not fetch `type_of(a_def_id)`, as it will cause a cycle
@@ -293,7 +292,7 @@ fn relate<R: TypeRelation<I>>(
                     relate_args_invariantly(relation, a.args, b.args)?
                 }
             };
-            Ok(ty::AliasTerm::new_from_args(relation.tcx(), a.def_id, args))
+            Ok(ty::AliasTerm::new_from_args(relation.cx(), a.def_id, args))
         }
     }
 }
@@ -343,7 +342,7 @@ fn relate<R: TypeRelation<I>>(
             }))
         } else {
             let args = relate_args_invariantly(relation, a.args, b.args)?;
-            Ok(ty::TraitRef::new_from_args(relation.tcx(), a.def_id, args))
+            Ok(ty::TraitRef::new_from_args(relation.cx(), a.def_id, args))
         }
     }
 }
@@ -377,7 +376,7 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
     a: I::Ty,
     b: I::Ty,
 ) -> RelateResult<I, I::Ty> {
-    let tcx = relation.tcx();
+    let cx = relation.cx();
     match (a.kind(), b.kind()) {
         (ty::Infer(_), _) | (_, ty::Infer(_)) => {
             // The caller should handle these cases!
@@ -388,7 +387,7 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
             panic!("bound types encountered in structurally_relate_tys")
         }
 
-        (ty::Error(guar), _) | (_, ty::Error(guar)) => Ok(Ty::new_error(tcx, guar)),
+        (ty::Error(guar), _) | (_, ty::Error(guar)) => Ok(Ty::new_error(cx, guar)),
 
         (ty::Never, _)
         | (ty::Char, _)
@@ -412,16 +411,16 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
 
         (ty::Adt(a_def, a_args), ty::Adt(b_def, b_args)) if a_def == b_def => {
             let args = relation.relate_item_args(a_def.def_id(), a_args, b_args)?;
-            Ok(Ty::new_adt(tcx, a_def, args))
+            Ok(Ty::new_adt(cx, a_def, args))
         }
 
-        (ty::Foreign(a_id), ty::Foreign(b_id)) if a_id == b_id => Ok(Ty::new_foreign(tcx, a_id)),
+        (ty::Foreign(a_id), ty::Foreign(b_id)) if a_id == b_id => Ok(Ty::new_foreign(cx, a_id)),
 
         (ty::Dynamic(a_obj, a_region, a_repr), ty::Dynamic(b_obj, b_region, b_repr))
             if a_repr == b_repr =>
         {
             Ok(Ty::new_dynamic(
-                tcx,
+                cx,
                 relation.relate(a_obj, b_obj)?,
                 relation.relate(a_region, b_region)?,
                 a_repr,
@@ -433,7 +432,7 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
             // the (anonymous) type of the same coroutine expression. So
             // all of their regions should be equated.
             let args = relate_args_invariantly(relation, a_args, b_args)?;
-            Ok(Ty::new_coroutine(tcx, a_id, args))
+            Ok(Ty::new_coroutine(cx, a_id, args))
         }
 
         (ty::CoroutineWitness(a_id, a_args), ty::CoroutineWitness(b_id, b_args))
@@ -443,7 +442,7 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
             // the (anonymous) type of the same coroutine expression. So
             // all of their regions should be equated.
             let args = relate_args_invariantly(relation, a_args, b_args)?;
-            Ok(Ty::new_coroutine_witness(tcx, a_id, args))
+            Ok(Ty::new_coroutine_witness(cx, a_id, args))
         }
 
         (ty::Closure(a_id, a_args), ty::Closure(b_id, b_args)) if a_id == b_id => {
@@ -451,14 +450,14 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
             // the (anonymous) type of the same closure expression. So
             // all of their regions should be equated.
             let args = relate_args_invariantly(relation, a_args, b_args)?;
-            Ok(Ty::new_closure(tcx, a_id, args))
+            Ok(Ty::new_closure(cx, a_id, args))
         }
 
         (ty::CoroutineClosure(a_id, a_args), ty::CoroutineClosure(b_id, b_args))
             if a_id == b_id =>
         {
             let args = relate_args_invariantly(relation, a_args, b_args)?;
-            Ok(Ty::new_coroutine_closure(tcx, a_id, args))
+            Ok(Ty::new_coroutine_closure(cx, a_id, args))
         }
 
         (ty::RawPtr(a_ty, a_mutbl), ty::RawPtr(b_ty, b_mutbl)) => {
@@ -475,7 +474,7 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
 
             let ty = relation.relate_with_variance(variance, info, a_ty, b_ty)?;
 
-            Ok(Ty::new_ptr(tcx, ty, a_mutbl))
+            Ok(Ty::new_ptr(cx, ty, a_mutbl))
         }
 
         (ty::Ref(a_r, a_ty, a_mutbl), ty::Ref(b_r, b_ty, b_mutbl)) => {
@@ -493,18 +492,18 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
             let r = relation.relate(a_r, b_r)?;
             let ty = relation.relate_with_variance(variance, info, a_ty, b_ty)?;
 
-            Ok(Ty::new_ref(tcx, r, ty, a_mutbl))
+            Ok(Ty::new_ref(cx, r, ty, a_mutbl))
         }
 
         (ty::Array(a_t, sz_a), ty::Array(b_t, sz_b)) => {
             let t = relation.relate(a_t, b_t)?;
             match relation.relate(sz_a, sz_b) {
-                Ok(sz) => Ok(Ty::new_array_with_const_len(tcx, t, sz)),
+                Ok(sz) => Ok(Ty::new_array_with_const_len(cx, t, sz)),
                 Err(err) => {
                     // Check whether the lengths are both concrete/known values,
                     // but are unequal, for better diagnostics.
-                    let sz_a = sz_a.try_to_target_usize(tcx);
-                    let sz_b = sz_b.try_to_target_usize(tcx);
+                    let sz_a = sz_a.try_to_target_usize(cx);
+                    let sz_b = sz_b.try_to_target_usize(cx);
 
                     match (sz_a, sz_b) {
                         (Some(sz_a_val), Some(sz_b_val)) if sz_a_val != sz_b_val => Err(
@@ -518,13 +517,13 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
 
         (ty::Slice(a_t), ty::Slice(b_t)) => {
             let t = relation.relate(a_t, b_t)?;
-            Ok(Ty::new_slice(tcx, t))
+            Ok(Ty::new_slice(cx, t))
         }
 
         (ty::Tuple(as_), ty::Tuple(bs)) => {
             if as_.len() == bs.len() {
                 Ok(Ty::new_tup_from_iter(
-                    tcx,
+                    cx,
                     iter::zip(as_.iter(), bs.iter()).map(|(a, b)| relation.relate(a, b)),
                 )?)
             } else if !(as_.is_empty() || bs.is_empty()) {
@@ -536,25 +535,25 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
 
         (ty::FnDef(a_def_id, a_args), ty::FnDef(b_def_id, b_args)) if a_def_id == b_def_id => {
             let args = relation.relate_item_args(a_def_id, a_args, b_args)?;
-            Ok(Ty::new_fn_def(tcx, a_def_id, args))
+            Ok(Ty::new_fn_def(cx, a_def_id, args))
         }
 
         (ty::FnPtr(a_fty), ty::FnPtr(b_fty)) => {
             let fty = relation.relate(a_fty, b_fty)?;
-            Ok(Ty::new_fn_ptr(tcx, fty))
+            Ok(Ty::new_fn_ptr(cx, fty))
         }
 
         // Alias tend to mostly already be handled downstream due to normalization.
         (ty::Alias(a_kind, a_data), ty::Alias(b_kind, b_data)) => {
             let alias_ty = relation.relate(a_data, b_data)?;
             assert_eq!(a_kind, b_kind);
-            Ok(Ty::new_alias(tcx, a_kind, alias_ty))
+            Ok(Ty::new_alias(cx, a_kind, alias_ty))
         }
 
         (ty::Pat(a_ty, a_pat), ty::Pat(b_ty, b_pat)) => {
             let ty = relation.relate(a_ty, b_ty)?;
             let pat = relation.relate(a_pat, b_pat)?;
-            Ok(Ty::new_pat(tcx, ty, pat))
+            Ok(Ty::new_pat(cx, ty, pat))
         }
 
         _ => Err(TypeError::Sorts(ExpectedFound::new(true, a, b))),
@@ -573,11 +572,11 @@ pub fn structurally_relate_consts<I: Interner, R: TypeRelation<I>>(
     mut b: I::Const,
 ) -> RelateResult<I, I::Const> {
     debug!("{}.structurally_relate_consts(a = {:?}, b = {:?})", relation.tag(), a, b);
-    let tcx = relation.tcx();
+    let cx = relation.cx();
 
-    if tcx.features().generic_const_exprs() {
-        a = tcx.expand_abstract_consts(a);
-        b = tcx.expand_abstract_consts(b);
+    if cx.features().generic_const_exprs() {
+        a = cx.expand_abstract_consts(a);
+        b = cx.expand_abstract_consts(b);
     }
 
     debug!("{}.structurally_relate_consts(normed_a = {:?}, normed_b = {:?})", relation.tag(), a, b);
@@ -607,8 +606,8 @@ pub fn structurally_relate_consts<I: Interner, R: TypeRelation<I>>(
         // be stabilized.
         (ty::ConstKind::Unevaluated(au), ty::ConstKind::Unevaluated(bu)) if au.def == bu.def => {
             if cfg!(debug_assertions) {
-                let a_ty = tcx.type_of(au.def).instantiate(tcx, au.args);
-                let b_ty = tcx.type_of(bu.def).instantiate(tcx, bu.args);
+                let a_ty = cx.type_of(au.def).instantiate(cx, au.args);
+                let b_ty = cx.type_of(bu.def).instantiate(cx, bu.args);
                 assert_eq!(a_ty, b_ty);
             }
 
@@ -618,11 +617,11 @@ pub fn structurally_relate_consts<I: Interner, R: TypeRelation<I>>(
                 au.args,
                 bu.args,
             )?;
-            return Ok(Const::new_unevaluated(tcx, ty::UnevaluatedConst { def: au.def, args }));
+            return Ok(Const::new_unevaluated(cx, ty::UnevaluatedConst { def: au.def, args }));
         }
         (ty::ConstKind::Expr(ae), ty::ConstKind::Expr(be)) => {
             let expr = relation.relate(ae, be)?;
-            return Ok(Const::new_expr(tcx, expr));
+            return Ok(Const::new_expr(cx, expr));
         }
         _ => false,
     };
diff --git a/compiler/rustc_type_ir/src/solve/mod.rs b/compiler/rustc_type_ir/src/solve/mod.rs
index 7934f996f0bd..2449ac47db6f 100644
--- a/compiler/rustc_type_ir/src/solve/mod.rs
+++ b/compiler/rustc_type_ir/src/solve/mod.rs
@@ -106,13 +106,13 @@ pub struct Goal<I: Interner, P> {
 }
 
 impl<I: Interner, P> Goal<I, P> {
-    pub fn new(tcx: I, param_env: I::ParamEnv, predicate: impl Upcast<I, P>) -> Goal<I, P> {
-        Goal { param_env, predicate: predicate.upcast(tcx) }
+    pub fn new(cx: I, param_env: I::ParamEnv, predicate: impl Upcast<I, P>) -> Goal<I, P> {
+        Goal { param_env, predicate: predicate.upcast(cx) }
     }
 
     /// Updates the goal to one with a different `predicate` but the same `param_env`.
-    pub fn with<Q>(self, tcx: I, predicate: impl Upcast<I, Q>) -> Goal<I, Q> {
-        Goal { param_env: self.param_env, predicate: predicate.upcast(tcx) }
+    pub fn with<Q>(self, cx: I, predicate: impl Upcast<I, Q>) -> Goal<I, Q> {
+        Goal { param_env: self.param_env, predicate: predicate.upcast(cx) }
     }
 }
 
diff --git a/compiler/rustc_type_ir/src/ty_kind/closure.rs b/compiler/rustc_type_ir/src/ty_kind/closure.rs
index 24a7c0c67e90..6c5bbbfd59ba 100644
--- a/compiler/rustc_type_ir/src/ty_kind/closure.rs
+++ b/compiler/rustc_type_ir/src/ty_kind/closure.rs
@@ -136,9 +136,9 @@ pub struct ClosureArgsParts<I: Interner> {
 impl<I: Interner> ClosureArgs<I> {
     /// Construct `ClosureArgs` from `ClosureArgsParts`, containing `Args`
     /// for the closure parent, alongside additional closure-specific components.
-    pub fn new(tcx: I, parts: ClosureArgsParts<I>) -> ClosureArgs<I> {
+    pub fn new(cx: I, parts: ClosureArgsParts<I>) -> ClosureArgs<I> {
         ClosureArgs {
-            args: tcx.mk_args_from_iter(parts.parent_args.iter().chain([
+            args: cx.mk_args_from_iter(parts.parent_args.iter().chain([
                 parts.closure_kind_ty.into(),
                 parts.closure_sig_as_fn_ptr_ty.into(),
                 parts.tupled_upvars_ty.into(),
@@ -258,9 +258,9 @@ pub struct CoroutineClosureArgsParts<I: Interner> {
 }
 
 impl<I: Interner> CoroutineClosureArgs<I> {
-    pub fn new(tcx: I, parts: CoroutineClosureArgsParts<I>) -> CoroutineClosureArgs<I> {
+    pub fn new(cx: I, parts: CoroutineClosureArgsParts<I>) -> CoroutineClosureArgs<I> {
         CoroutineClosureArgs {
-            args: tcx.mk_args_from_iter(parts.parent_args.iter().chain([
+            args: cx.mk_args_from_iter(parts.parent_args.iter().chain([
                 parts.closure_kind_ty.into(),
                 parts.signature_parts_ty.into(),
                 parts.tupled_upvars_ty.into(),
@@ -409,14 +409,14 @@ impl<I: Interner> CoroutineClosureSignature<I> {
     /// When the kind and upvars are known, use the other helper functions.
     pub fn to_coroutine(
         self,
-        tcx: I,
+        cx: I,
         parent_args: I::GenericArgsSlice,
         coroutine_kind_ty: I::Ty,
         coroutine_def_id: I::DefId,
         tupled_upvars_ty: I::Ty,
     ) -> I::Ty {
         let coroutine_args = ty::CoroutineArgs::new(
-            tcx,
+            cx,
             ty::CoroutineArgsParts {
                 parent_args,
                 kind_ty: coroutine_kind_ty,
@@ -428,7 +428,7 @@ pub fn to_coroutine(
             },
         );
 
-        Ty::new_coroutine(tcx, coroutine_def_id, coroutine_args.args)
+        Ty::new_coroutine(cx, coroutine_def_id, coroutine_args.args)
     }
 
     /// Given known upvars and a [`ClosureKind`](ty::ClosureKind), compute the coroutine
@@ -438,7 +438,7 @@ pub fn to_coroutine(
     /// that the `ClosureKind` is actually supported by the coroutine-closure.
     pub fn to_coroutine_given_kind_and_upvars(
         self,
-        tcx: I,
+        cx: I,
         parent_args: I::GenericArgsSlice,
         coroutine_def_id: I::DefId,
         goal_kind: ty::ClosureKind,
@@ -447,7 +447,7 @@ pub fn to_coroutine_given_kind_and_upvars(
         coroutine_captures_by_ref_ty: I::Ty,
     ) -> I::Ty {
         let tupled_upvars_ty = Self::tupled_upvars_by_closure_kind(
-            tcx,
+            cx,
             goal_kind,
             self.tupled_inputs_ty,
             closure_tupled_upvars_ty,
@@ -456,9 +456,9 @@ pub fn to_coroutine_given_kind_and_upvars(
         );
 
         self.to_coroutine(
-            tcx,
+            cx,
             parent_args,
-            Ty::from_coroutine_closure_kind(tcx, goal_kind),
+            Ty::from_coroutine_closure_kind(cx, goal_kind),
             coroutine_def_id,
             tupled_upvars_ty,
         )
@@ -474,7 +474,7 @@ pub fn to_coroutine_given_kind_and_upvars(
     /// lifetimes are related to the lifetime of the borrow on the closure made for
     /// the call. This allows borrowck to enforce the self-borrows correctly.
     pub fn tupled_upvars_by_closure_kind(
-        tcx: I,
+        cx: I,
         kind: ty::ClosureKind,
         tupled_inputs_ty: I::Ty,
         closure_tupled_upvars_ty: I::Ty,
@@ -488,12 +488,12 @@ pub fn tupled_upvars_by_closure_kind(
                 };
                 let coroutine_captures_by_ref_ty =
                     sig.output().skip_binder().fold_with(&mut FoldEscapingRegions {
-                        interner: tcx,
+                        interner: cx,
                         region: env_region,
                         debruijn: ty::INNERMOST,
                     });
                 Ty::new_tup_from_iter(
-                    tcx,
+                    cx,
                     tupled_inputs_ty
                         .tuple_fields()
                         .iter()
@@ -501,7 +501,7 @@ pub fn tupled_upvars_by_closure_kind(
                 )
             }
             ty::ClosureKind::FnOnce => Ty::new_tup_from_iter(
-                tcx,
+                cx,
                 tupled_inputs_ty
                     .tuple_fields()
                     .iter()
@@ -615,9 +615,9 @@ pub struct CoroutineArgsParts<I: Interner> {
 impl<I: Interner> CoroutineArgs<I> {
     /// Construct `CoroutineArgs` from `CoroutineArgsParts`, containing `Args`
     /// for the coroutine parent, alongside additional coroutine-specific components.
-    pub fn new(tcx: I, parts: CoroutineArgsParts<I>) -> CoroutineArgs<I> {
+    pub fn new(cx: I, parts: CoroutineArgsParts<I>) -> CoroutineArgs<I> {
         CoroutineArgs {
-            args: tcx.mk_args_from_iter(parts.parent_args.iter().chain([
+            args: cx.mk_args_from_iter(parts.parent_args.iter().chain([
                 parts.kind_ty.into(),
                 parts.resume_ty.into(),
                 parts.yield_ty.into(),