Rollup merge of rust-lang#133443 - fmease:rm-dead-eff-code-ii, r=compiler-errors

Remove dead code stemming from the old effects desugaring (II)

Follow-up to rust-lang#132374.
r? project-const-traits

Author: GuillaumeGomez

compiler/rustc_ast_lowering/src/lib.rs

@@ -2117,11 +2117,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             hir::ConstArgKind::Anon(ct)
         };
 
-        self.arena.alloc(hir::ConstArg {
-            hir_id: self.next_id(),
-            kind: ct_kind,
-            is_desugared_from_effects: false,
-        })
+        self.arena.alloc(hir::ConstArg { hir_id: self.next_id(), kind: ct_kind })
     }
 
     /// See [`hir::ConstArg`] for when to use this function vs
@@ -2163,19 +2159,11 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 None,
             );
 
-            return ConstArg {
-                hir_id: self.next_id(),
-                kind: hir::ConstArgKind::Path(qpath),
-                is_desugared_from_effects: false,
-            };
+            return ConstArg { hir_id: self.next_id(), kind: hir::ConstArgKind::Path(qpath) };
         }
 
         let lowered_anon = self.lower_anon_const_to_anon_const(anon);
-        ConstArg {
-            hir_id: self.next_id(),
-            kind: hir::ConstArgKind::Anon(lowered_anon),
-            is_desugared_from_effects: false,
-        }
+        ConstArg { hir_id: self.next_id(), kind: hir::ConstArgKind::Anon(lowered_anon) }
     }
 
     /// See [`hir::ConstArg`] for when to use this function vs

compiler/rustc_hir/src/hir.rs

@@ -261,8 +261,6 @@ pub struct ConstArg<'hir> {
     #[stable_hasher(ignore)]
     pub hir_id: HirId,
     pub kind: ConstArgKind<'hir>,
-    /// Indicates whether this comes from a `~const` desugaring.
-    pub is_desugared_from_effects: bool,
 }
 
 impl<'hir> ConstArg<'hir> {
@@ -462,14 +460,7 @@ impl<'hir> GenericArgs<'hir> {
     /// This function returns the number of type and const generic params.
     /// It should only be used for diagnostics.
     pub fn num_generic_params(&self) -> usize {
-        self.args
-            .iter()
-            .filter(|arg| match arg {
-                GenericArg::Lifetime(_)
-                | GenericArg::Const(ConstArg { is_desugared_from_effects: true, .. }) => false,
-                _ => true,
-            })
-            .count()
+        self.args.iter().filter(|arg| !matches!(arg, GenericArg::Lifetime(_))).count()
     }
 
     /// The span encompassing the arguments and constraints[^1] inside the surrounding brackets.

src/librustdoc/clean/mod.rs

@@ -2516,14 +2516,6 @@ fn clean_generic_args<'tcx>(
                     }
                     hir::GenericArg::Lifetime(_) => GenericArg::Lifetime(Lifetime::elided()),
                     hir::GenericArg::Type(ty) => GenericArg::Type(clean_ty(ty, cx)),
-                    // Checking for `is_desugared_from_effects` on the `AnonConst` not only accounts for the case
-                    // where the argument is `host` but for all possible cases (e.g., `true`, `false`).
-                    hir::GenericArg::Const(hir::ConstArg {
-                        is_desugared_from_effects: true,
-                        ..
-                    }) => {
-                        return None;
-                    }
                     hir::GenericArg::Const(ct) => GenericArg::Const(Box::new(clean_const(ct, cx))),
                     hir::GenericArg::Infer(_inf) => GenericArg::Infer,
                 })