6 files changed, 21 insertions, 42 deletions
diff --git a/compiler/rustc_middle/src/thir.rs b/compiler/rustc_middle/src/thir.rs
index 8d373cb3b30..c168142fb1e 100644
--- a/compiler/rustc_middle/src/thir.rs
+++ b/compiler/rustc_middle/src/thir.rs
@@ -747,6 +747,9 @@ pub struct Ascription<'tcx> {
 
 #[derive(Clone, Debug, HashStable, TypeVisitable)]
 pub enum PatKind<'tcx> {
+    /// A missing pattern, e.g. for an anonymous param in a bare fn like `fn f(u32)`.
+    Missing,
+
     /// A wildcard pattern: `_`.
     Wild,
 
@@ -812,23 +815,17 @@ pub enum PatKind<'tcx> {
     },
 
     /// Pattern obtained by converting a constant (inline or named) to its pattern
-    /// representation using `const_to_pat`.
+    /// representation using `const_to_pat`. This is used for unsafety checking.
     ExpandedConstant {
-        /// [DefId] of the constant, we need this so that we have a
-        /// reference that can be used by unsafety checking to visit nested
-        /// unevaluated constants and for diagnostics. If the `DefId` doesn't
-        /// correspond to a local crate, it points at the `const` item.
+        /// [DefId] of the constant item.
         def_id: DefId,
-        /// If `false`, then `def_id` points at a `const` item, otherwise it
-        /// corresponds to a local inline const.
-        is_inline: bool,
-        /// If the inline constant is used in a range pattern, this subpattern
-        /// represents the range (if both ends are inline constants, there will
-        /// be multiple InlineConstant wrappers).
+        /// The pattern that the constant lowered to.
         ///
-        /// Otherwise, the actual pattern that the constant lowered to. As with
-        /// other constants, inline constants are matched structurally where
-        /// possible.
+        /// HACK: we need to keep the `DefId` of inline constants around for unsafety checking;
+        /// therefore when a range pattern contains inline constants, we re-wrap the range pattern
+        /// with the `ExpandedConstant` nodes that correspond to the range endpoints. Hence
+        /// `subpattern` may actually be a range pattern, and `def_id` be the constant for one of
+        /// its endpoints.
         subpattern: Box<Pat<'tcx>>,
     },
 
diff --git a/compiler/rustc_middle/src/thir/visit.rs b/compiler/rustc_middle/src/thir/visit.rs
index 7d62ab7970d..f3da2a5cc8e 100644
--- a/compiler/rustc_middle/src/thir/visit.rs
+++ b/compiler/rustc_middle/src/thir/visit.rs
@@ -250,7 +250,8 @@ pub(crate) fn for_each_immediate_subpat<'a, 'tcx>(
     mut callback: impl FnMut(&'a Pat<'tcx>),
 ) {
     match &pat.kind {
-        PatKind::Wild
+        PatKind::Missing
+        | PatKind::Wild
         | PatKind::Binding { subpattern: None, .. }
         | PatKind::Constant { value: _ }
         | PatKind::Range(_)
diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs
index 55ebd15248c..07f2a602f2b 100644
--- a/compiler/rustc_middle/src/ty/instance.rs
+++ b/compiler/rustc_middle/src/ty/instance.rs
@@ -71,7 +71,7 @@ pub enum InstanceKind<'tcx> {
     /// - coroutines
     Item(DefId),
 
-    /// An intrinsic `fn` item (with `"rust-intrinsic"` ABI).
+    /// An intrinsic `fn` item (with`#[rustc_instrinsic]`).
     ///
     /// Alongside `Virtual`, this is the only `InstanceKind` that does not have its own callable MIR.
     /// Instead, codegen and const eval "magically" evaluate calls to intrinsics purely in the
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index ebb6a8c08a5..7ebfebea44e 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -1265,9 +1265,7 @@ pub fn fn_can_unwind(tcx: TyCtxt<'_>, fn_def_id: Option<DefId>, abi: ExternAbi)
         | CCmseNonSecureCall
         | CCmseNonSecureEntry
         | Unadjusted => false,
-        Rust | RustCall | RustCold | RustIntrinsic => {
-            tcx.sess.panic_strategy() == PanicStrategy::Unwind
-        }
+        Rust | RustCall | RustCold => tcx.sess.panic_strategy() == PanicStrategy::Unwind,
     }
 }
 
diff --git a/compiler/rustc_middle/src/ty/significant_drop_order.rs b/compiler/rustc_middle/src/ty/significant_drop_order.rs
index 4881d611c12..ce4208f2c44 100644
--- a/compiler/rustc_middle/src/ty/significant_drop_order.rs
+++ b/compiler/rustc_middle/src/ty/significant_drop_order.rs
@@ -143,25 +143,11 @@ pub fn ty_dtor_span<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Option<Span> {
         | ty::UnsafeBinder(_) => None,
 
         ty::Adt(adt_def, _) => {
-            let did = adt_def.did();
-            let try_local_did_span = |did: DefId| {
-                if let Some(local) = did.as_local() {
-                    tcx.source_span(local)
-                } else {
-                    tcx.def_span(did)
-                }
-            };
-            let dtor = if let Some(dtor) = tcx.adt_destructor(did) {
-                dtor.did
-            } else if let Some(dtor) = tcx.adt_async_destructor(did) {
-                return Some(tcx.source_span(dtor.impl_did));
+            if let Some(dtor) = tcx.adt_destructor(adt_def.did()) {
+                Some(tcx.def_span(tcx.parent(dtor.did)))
             } else {
-                return Some(try_local_did_span(did));
-            };
-            let def_key = tcx.def_key(dtor);
-            let Some(parent_index) = def_key.parent else { return Some(try_local_did_span(dtor)) };
-            let parent_did = DefId { index: parent_index, krate: dtor.krate };
-            Some(try_local_did_span(parent_did))
+                Some(tcx.def_span(adt_def.did()))
+            }
         }
         ty::Coroutine(did, _)
         | ty::CoroutineWitness(did, _)
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index e4863896fc8..857b462b9eb 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -2,7 +2,7 @@
 
 use std::{fmt, iter};
 
-use rustc_abi::{ExternAbi, Float, Integer, IntegerType, Size};
+use rustc_abi::{Float, Integer, IntegerType, Size};
 use rustc_apfloat::Float as _;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
@@ -1719,10 +1719,7 @@ pub fn is_doc_notable_trait(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
 /// the compiler to make some assumptions about its shape; if the user doesn't use a feature gate, they may
 /// cause an ICE that we otherwise may want to prevent.
 pub fn intrinsic_raw(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<ty::IntrinsicDef> {
-    if tcx.features().intrinsics()
-        && (matches!(tcx.fn_sig(def_id).skip_binder().abi(), ExternAbi::RustIntrinsic)
-            || tcx.has_attr(def_id, sym::rustc_intrinsic))
-    {
+    if tcx.features().intrinsics() && tcx.has_attr(def_id, sym::rustc_intrinsic) {
         let must_be_overridden = match tcx.hir_node_by_def_id(def_id) {
             hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn { has_body, .. }, .. }) => {
                 !has_body