Differentiate between methods and associated functions

Accurately refer to assoc fn without receiver as assoc fn instead of methods.
Add `AssocItem::descr` method to centralize where we call methods and associated functions.

2 files changed, 21 insertions, 6 deletions

diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs
index 4c243e6330b..edab6b5ebde 100644
--- a/compiler/rustc_middle/src/hir/map/mod.rs
+++ b/compiler/rustc_middle/src/hir/map/mod.rs
@@ -1165,17 +1165,23 @@ fn hir_id_to_string(map: Map<'_>, id: HirId) -> String {
         }
         Node::ImplItem(ii) => {
             let kind = match ii.kind {
-                ImplItemKind::Const(..) => "assoc const",
-                ImplItemKind::Fn(..) => "method",
-                ImplItemKind::Type(_) => "assoc type",
+                ImplItemKind::Const(..) => "associated constant",
+                ImplItemKind::Fn(fn_sig, _) => match fn_sig.decl.implicit_self {
+                    ImplicitSelfKind::None => "associated function",
+                    _ => "method",
+                },
+                ImplItemKind::Type(_) => "associated type",
             };
             format!("{id} ({kind} `{}` in {})", ii.ident, path_str(ii.owner_id.def_id))
         }
         Node::TraitItem(ti) => {
             let kind = match ti.kind {
-                TraitItemKind::Const(..) => "assoc constant",
-                TraitItemKind::Fn(..) => "trait method",
-                TraitItemKind::Type(..) => "assoc type",
+                TraitItemKind::Const(..) => "associated constant",
+                TraitItemKind::Fn(fn_sig, _) => match fn_sig.decl.implicit_self {
+                    ImplicitSelfKind::None => "associated function",
+                    _ => "trait method",
+                },
+                TraitItemKind::Type(..) => "associated type",
             };
 
             format!("{id} ({kind} `{}` in {})", ti.ident, path_str(ti.owner_id.def_id))
diff --git a/compiler/rustc_middle/src/ty/assoc.rs b/compiler/rustc_middle/src/ty/assoc.rs
index 0ce5c613c4c..db56e0016a2 100644
--- a/compiler/rustc_middle/src/ty/assoc.rs
+++ b/compiler/rustc_middle/src/ty/assoc.rs
@@ -98,6 +98,15 @@ impl AssocItem {
         }
     }
 
+    pub fn descr(&self) -> &'static str {
+        match self.kind {
+            ty::AssocKind::Const => "const",
+            ty::AssocKind::Fn if self.fn_has_self_parameter => "method",
+            ty::AssocKind::Fn => "associated function",
+            ty::AssocKind::Type => "type",
+        }
+    }
+
     pub fn is_impl_trait_in_trait(&self) -> bool {
         self.opt_rpitit_info.is_some()
     }