6 files changed, 28 insertions, 12 deletions
diff --git a/compiler/rustc_middle/src/middle/exported_symbols.rs b/compiler/rustc_middle/src/middle/exported_symbols.rs
index 3c62017072e..1d67d0fe3bb 100644
--- a/compiler/rustc_middle/src/middle/exported_symbols.rs
+++ b/compiler/rustc_middle/src/middle/exported_symbols.rs
@@ -56,7 +56,7 @@ impl<'tcx> ExportedSymbol<'tcx> {
         match *self {
             ExportedSymbol::NonGeneric(def_id) => tcx.symbol_name(ty::Instance::mono(tcx, def_id)),
             ExportedSymbol::Generic(def_id, args) => {
-                tcx.symbol_name(ty::Instance::new(def_id, args))
+                tcx.symbol_name(ty::Instance::new_raw(def_id, args))
             }
             ExportedSymbol::DropGlue(ty) => {
                 tcx.symbol_name(ty::Instance::resolve_drop_in_place(tcx, ty))
diff --git a/compiler/rustc_middle/src/mir/interpret/queries.rs b/compiler/rustc_middle/src/mir/interpret/queries.rs
index e5d1dda3aa0..4a5c42c721c 100644
--- a/compiler/rustc_middle/src/mir/interpret/queries.rs
+++ b/compiler/rustc_middle/src/mir/interpret/queries.rs
@@ -23,7 +23,7 @@ impl<'tcx> TyCtxt<'tcx> {
         // into `const_eval` which will return `ErrorHandled::TooGeneric` if any of them are
         // encountered.
         let args = GenericArgs::identity_for_item(self, def_id);
-        let instance = ty::Instance::new(def_id, args);
+        let instance = ty::Instance::new_raw(def_id, args);
         let cid = GlobalId { instance, promoted: None };
         let typing_env = ty::TypingEnv::post_analysis(self, def_id);
         self.const_eval_global_id(typing_env, cid, DUMMY_SP)
@@ -39,7 +39,7 @@ impl<'tcx> TyCtxt<'tcx> {
         // into `const_eval` which will return `ErrorHandled::TooGeneric` if any of them are
         // encountered.
         let args = GenericArgs::identity_for_item(self, def_id);
-        let instance = ty::Instance::new(def_id, args);
+        let instance = ty::Instance::new_raw(def_id, args);
         let cid = GlobalId { instance, promoted: None };
         let typing_env = ty::TypingEnv::post_analysis(self, def_id);
         let inputs = self.erase_regions(typing_env.as_query_input(cid));
@@ -209,7 +209,7 @@ impl<'tcx> TyCtxtEnsureOk<'tcx> {
         // into `const_eval` which will return `ErrorHandled::TooGeneric` if any of them are
         // encountered.
         let args = GenericArgs::identity_for_item(self.tcx, def_id);
-        let instance = ty::Instance::new(def_id, self.tcx.erase_regions(args));
+        let instance = ty::Instance::new_raw(def_id, self.tcx.erase_regions(args));
         let cid = GlobalId { instance, promoted: None };
         let typing_env = ty::TypingEnv::post_analysis(self.tcx, def_id);
         // Const-eval shouldn't depend on lifetimes at all, so we can erase them, which should
diff --git a/compiler/rustc_middle/src/mir/mono.rs b/compiler/rustc_middle/src/mir/mono.rs
index 6b413a7383a..7243f87ee63 100644
--- a/compiler/rustc_middle/src/mir/mono.rs
+++ b/compiler/rustc_middle/src/mir/mono.rs
@@ -318,7 +318,7 @@ impl<'tcx> fmt::Display for MonoItem<'tcx> {
         match *self {
             MonoItem::Fn(instance) => write!(f, "fn {instance}"),
             MonoItem::Static(def_id) => {
-                write!(f, "static {}", Instance::new(def_id, GenericArgs::empty()))
+                write!(f, "static {}", Instance::new_raw(def_id, GenericArgs::empty()))
             }
             MonoItem::GlobalAsm(..) => write!(f, "global_asm"),
         }
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 6af9d4aae30..4981233cebe 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -2481,7 +2481,7 @@ rustc_queries! {
     query resolve_instance_raw(
         key: ty::PseudoCanonicalInput<'tcx, (DefId, GenericArgsRef<'tcx>)>
     ) -> Result<Option<ty::Instance<'tcx>>, ErrorGuaranteed> {
-        desc { "resolving instance `{}`", ty::Instance::new(key.value.0, key.value.1) }
+        desc { "resolving instance `{}`", ty::Instance::new_raw(key.value.0, key.value.1) }
     }
 
     query reveal_opaque_types_in_bounds(key: ty::Clauses<'tcx>) -> ty::Clauses<'tcx> {
diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs
index d660e7d0d60..0d99a1b5149 100644
--- a/compiler/rustc_middle/src/ty/instance.rs
+++ b/compiler/rustc_middle/src/ty/instance.rs
@@ -491,7 +491,15 @@ fn resolve_async_drop_poll<'tcx>(mut cor_ty: Ty<'tcx>) -> Instance<'tcx> {
 }
 
 impl<'tcx> Instance<'tcx> {
-    pub fn new(def_id: DefId, args: GenericArgsRef<'tcx>) -> Instance<'tcx> {
+    /// Creates a new [`InstanceKind::Item`] from the `def_id` and `args`.
+    ///
+    /// Note that this item corresponds to the body of `def_id` directly, which
+    /// likely does not make sense for trait items which need to be resolved to an
+    /// implementation, and which may not even have a body themselves. Usages of
+    /// this function should probably use [`Instance::expect_resolve`], or if run
+    /// in a polymorphic environment or within a lint (that may encounter ambiguity)
+    /// [`Instance::try_resolve`] instead.
+    pub fn new_raw(def_id: DefId, args: GenericArgsRef<'tcx>) -> Instance<'tcx> {
         assert!(
             !args.has_escaping_bound_vars(),
             "args of instance {def_id:?} has escaping bound vars: {args:?}"
@@ -510,7 +518,7 @@ impl<'tcx> Instance<'tcx> {
             }
         });
 
-        Instance::new(def_id, args)
+        Instance::new_raw(def_id, args)
     }
 
     #[inline]
@@ -603,7 +611,7 @@ impl<'tcx> Instance<'tcx> {
                 let type_length = type_length(args);
                 if !tcx.type_length_limit().value_within_limit(type_length) {
                     let (shrunk, written_to_path) =
-                        shrunk_instance_name(tcx, Instance::new(def_id, args));
+                        shrunk_instance_name(tcx, Instance::new_raw(def_id, args));
                     let mut path = PathBuf::new();
                     let was_written = if let Some(path2) = written_to_path {
                         path = path2;
@@ -773,7 +781,7 @@ impl<'tcx> Instance<'tcx> {
 
         match needs_fn_once_adapter_shim(actual_kind, requested_kind) {
             Ok(true) => Instance::fn_once_adapter_instance(tcx, def_id, args),
-            _ => Instance::new(def_id, args),
+            _ => Instance::new_raw(def_id, args),
         }
     }
 
@@ -899,7 +907,7 @@ impl<'tcx> Instance<'tcx> {
             // This is important for `Iterator`'s combinators, but also useful for
             // adding future default methods to `Future`, for instance.
             debug_assert!(tcx.defaultness(trait_item_id).has_value());
-            Some(Instance::new(trait_item_id, rcvr_args))
+            Some(Instance::new_raw(trait_item_id, rcvr_args))
         }
     }
 
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index b8da97c42d4..f1ef98c2097 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -51,9 +51,17 @@ use rustc_session::lint::LintBuffer;
 pub use rustc_session::lint::RegisteredTools;
 use rustc_span::hygiene::MacroKind;
 use rustc_span::{DUMMY_SP, ExpnId, ExpnKind, Ident, Span, Symbol, kw, sym};
-pub use rustc_type_ir::data_structures::DelayedSet;
+pub use rustc_type_ir::data_structures::{DelayedMap, DelayedSet};
+#[allow(
+    hidden_glob_reexports,
+    rustc::usage_of_type_ir_inherent,
+    rustc::non_glob_import_of_type_ir_inherent
+)]
+use rustc_type_ir::inherent;
 pub use rustc_type_ir::relate::VarianceDiagInfo;
 pub use rustc_type_ir::*;
+#[allow(hidden_glob_reexports, unused_imports)]
+use rustc_type_ir::{InferCtxtLike, Interner};
 use tracing::{debug, instrument};
 pub use vtable::*;
 use {rustc_ast as ast, rustc_attr_data_structures as attr, rustc_hir as hir};