3 files changed, 4 insertions, 73 deletions

diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index b516810205f..7822ecc2c1f 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -433,23 +433,12 @@ rustc_queries! {
         /// full predicates are available (note that supertraits have
         /// additional acyclicity requirements).
         query super_predicates_of(key: DefId) -> ty::GenericPredicates<'tcx> {
-            desc { |tcx| "computing the super predicates of `{}`", tcx.def_path_str(key) }
-        }
-
-        /// The `Option<Ident>` is the name of an associated type. If it is `None`, then this query
-        /// returns the full set of predicates. If `Some<Ident>`, then the query returns only the
-        /// subset of super-predicates that reference traits that define the given associated type.
-        /// This is used to avoid cycles in resolving types like `T::Item`.
-        query super_predicates_that_define_assoc_type(key: (DefId, Option<rustc_span::symbol::Ident>)) -> ty::GenericPredicates<'tcx> {
-            desc { |tcx| "computing the super traits of `{}`{}",
-                tcx.def_path_str(key.0),
-                if let Some(assoc_name) = key.1 { format!(" with associated type name `{}`", assoc_name) } else { "".to_string() },
-            }
+            desc { |tcx| "computing the supertraits of `{}`", tcx.def_path_str(key) }
         }
 
         /// To avoid cycles within the predicates of a single item we compute
         /// per-type-parameter predicates for resolving `T::AssocTy`.
-        query type_param_predicates(key: (DefId, LocalDefId, rustc_span::symbol::Ident)) -> ty::GenericPredicates<'tcx> {
+        query type_param_predicates(key: (DefId, LocalDefId)) -> ty::GenericPredicates<'tcx> {
             desc { |tcx| "computing the bounds for type parameter `{}`", {
                 let id = tcx.hir().local_def_id_to_hir_id(key.1);
                 tcx.hir().ty_param_name(id)
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index f078bbacfe9..1b3416e112b 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -51,7 +51,7 @@ use rustc_session::config::{BorrowckMode, CrateType, OutputFilenames};
 use rustc_session::lint::{Level, Lint};
 use rustc_session::Session;
 use rustc_span::source_map::MultiSpan;
-use rustc_span::symbol::{kw, sym, Ident, Symbol};
+use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::{Span, DUMMY_SP};
 use rustc_target::abi::{Layout, TargetDataLayout, VariantIdx};
 use rustc_target::spec::abi;
@@ -2066,42 +2066,6 @@ impl<'tcx> TyCtxt<'tcx> {
         self.mk_fn_ptr(sig.map_bound(|sig| ty::FnSig { unsafety: hir::Unsafety::Unsafe, ..sig }))
     }
 
-    /// Given the def_id of a Trait `trait_def_id` and the name of an associated item `assoc_name`
-    /// returns true if the `trait_def_id` defines an associated item of name `assoc_name`.
-    pub fn trait_may_define_assoc_type(self, trait_def_id: DefId, assoc_name: Ident) -> bool {
-        self.super_traits_of(trait_def_id).any(|trait_did| {
-            self.associated_items(trait_did)
-                .find_by_name_and_kind(self, assoc_name, ty::AssocKind::Type, trait_did)
-                .is_some()
-        })
-    }
-
-    /// Computes the def-ids of the transitive super-traits of `trait_def_id`. This (intentionally)
-    /// does not compute the full elaborated super-predicates but just the set of def-ids. It is used
-    /// to identify which traits may define a given associated type to help avoid cycle errors.
-    /// Returns a `DefId` iterator.
-    fn super_traits_of(self, trait_def_id: DefId) -> impl Iterator<Item = DefId> + 'tcx {
-        let mut set = FxHashSet::default();
-        let mut stack = vec![trait_def_id];
-
-        set.insert(trait_def_id);
-
-        iter::from_fn(move || -> Option<DefId> {
-            let trait_did = stack.pop()?;
-            let generic_predicates = self.super_predicates_of(trait_did);
-
-            for (predicate, _) in generic_predicates.predicates {
-                if let ty::PredicateAtom::Trait(data, _) = predicate.skip_binders() {
-                    if set.insert(data.def_id()) {
-                        stack.push(data.def_id());
-                    }
-                }
-            }
-
-            Some(trait_did)
-        })
-    }
-
     /// Given a closure signature, returns an equivalent fn signature. Detuples
     /// and so forth -- so e.g., if we have a sig with `Fn<(u32, i32)>` then
     /// you would get a `fn(u32, i32)`.
diff --git a/compiler/rustc_middle/src/ty/query/keys.rs b/compiler/rustc_middle/src/ty/query/keys.rs
index 3949c303f72..a005990264c 100644
--- a/compiler/rustc_middle/src/ty/query/keys.rs
+++ b/compiler/rustc_middle/src/ty/query/keys.rs
@@ -7,7 +7,7 @@ use crate::ty::subst::{GenericArg, SubstsRef};
 use crate::ty::{self, Ty, TyCtxt};
 use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE};
 use rustc_query_system::query::DefaultCacheSelector;
-use rustc_span::symbol::{Ident, Symbol};
+use rustc_span::symbol::Symbol;
 use rustc_span::{Span, DUMMY_SP};
 
 /// The `Key` trait controls what types can legally be used as the key
@@ -149,28 +149,6 @@ impl Key for (LocalDefId, DefId) {
     }
 }
 
-impl Key for (DefId, Option<Ident>) {
-    type CacheSelector = DefaultCacheSelector;
-
-    fn query_crate(&self) -> CrateNum {
-        self.0.krate
-    }
-    fn default_span(&self, tcx: TyCtxt<'_>) -> Span {
-        tcx.def_span(self.0)
-    }
-}
-
-impl Key for (DefId, LocalDefId, Ident) {
-    type CacheSelector = DefaultCacheSelector;
-
-    fn query_crate(&self) -> CrateNum {
-        self.0.krate
-    }
-    fn default_span(&self, tcx: TyCtxt<'_>) -> Span {
-        self.1.default_span(tcx)
-    }
-}
-
 impl Key for (CrateNum, DefId) {
     type CacheSelector = DefaultCacheSelector;