From a33b2f9ad22fc33f90accd7bfa7a07e557b7b271 Mon Sep 17 00:00:00 2001
From: cyrgani <ansgar.w.zielke@gmail.com>
Date: Mon, 24 Aug 2026 13:02:57 +0000
Subject: [PATCH 1/8] take `&Item` instead of `Annotatable` as derive macro
 input

---
 .../src/deriving/bounds.rs                    |   4 +-
 .../src/deriving/clone.rs                     |  51 ++++-----
 .../src/deriving/cmp/eq.rs                    |   2 +-
 .../src/deriving/cmp/ord.rs                   |   2 +-
 .../src/deriving/cmp/partial_eq.rs            |   2 +-
 .../src/deriving/cmp/partial_ord.rs           |  49 ++++-----
 .../src/deriving/coerce_pointee.rs            |  10 +-
 .../src/deriving/debug.rs                     |   2 +-
 .../src/deriving/default.rs                   |  12 +-
 .../rustc_builtin_macros/src/deriving/from.rs |   8 +-
 .../src/deriving/generic/mod.rs               | 103 ++++++++----------
 .../rustc_builtin_macros/src/deriving/hash.rs |   2 +-
 .../rustc_builtin_macros/src/deriving/mod.rs  |   9 +-
 .../src/deriving/reborrow.rs                  |  39 +++----
 14 files changed, 130 insertions(+), 165 deletions(-)

diff --git a/compiler/rustc_builtin_macros/src/deriving/bounds.rs b/compiler/rustc_builtin_macros/src/deriving/bounds.rs
index 48fdb4dd39ce2..5b71d38c63e2e 100644
--- a/compiler/rustc_builtin_macros/src/deriving/bounds.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/bounds.rs
@@ -9,7 +9,7 @@ pub(crate) fn expand_deriving_copy(
     cx: &ExtCtxt<'_>,
     span: Span,
     mitem: &MetaItem,
-    item: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     is_const: bool,
 ) {
@@ -34,7 +34,7 @@ pub(crate) fn expand_deriving_const_param_ty(
     cx: &ExtCtxt<'_>,
     span: Span,
     mitem: &MetaItem,
-    item: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     is_const: bool,
 ) {
diff --git a/compiler/rustc_builtin_macros/src/deriving/clone.rs b/compiler/rustc_builtin_macros/src/deriving/clone.rs
index b4374e32f6051..be70cf0b584a1 100644
--- a/compiler/rustc_builtin_macros/src/deriving/clone.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/clone.rs
@@ -12,7 +12,7 @@ pub(crate) fn expand_deriving_clone(
     cx: &ExtCtxt<'_>,
     span: Span,
     mitem: &MetaItem,
-    item: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     is_const: bool,
 ) {
@@ -32,35 +32,30 @@ pub(crate) fn expand_deriving_clone(
     let bounds;
     let substructure;
     let is_simple;
-    match item {
-        Annotatable::Item(annitem) => match &annitem.kind {
-            ItemKind::Struct(_, Generics { params, .. }, _)
-            | ItemKind::Enum(_, Generics { params, .. }, _) => {
-                let container_id = cx.current_expansion.id.expn_data().parent.expect_local();
-                let has_derive_copy = cx.resolver.has_derive_copy(container_id);
-                bounds = smallvec![];
-                if has_derive_copy
-                    && !params
-                        .iter()
-                        .any(|param| matches!(param.kind, ast::GenericParamKind::Type { .. }))
-                {
-                    is_simple = true;
-                    substructure =
-                        combine_substructure(|c, s, sub| cs_clone_simple(c, s, sub, false));
-                } else {
-                    is_simple = false;
-                    substructure = combine_substructure(cs_clone);
-                }
-            }
-            ItemKind::Union(..) => {
-                bounds = smallvec![Path(path_std!(marker::Copy))];
+    match &item.kind {
+        ItemKind::Struct(_, Generics { params, .. }, _)
+        | ItemKind::Enum(_, Generics { params, .. }, _) => {
+            let container_id = cx.current_expansion.id.expn_data().parent.expect_local();
+            let has_derive_copy = cx.resolver.has_derive_copy(container_id);
+            bounds = smallvec![];
+            if has_derive_copy
+                && !params
+                    .iter()
+                    .any(|param| matches!(param.kind, ast::GenericParamKind::Type { .. }))
+            {
                 is_simple = true;
-                substructure = combine_substructure(|c, s, sub| cs_clone_simple(c, s, sub, true));
+                substructure = combine_substructure(|c, s, sub| cs_clone_simple(c, s, sub, false));
+            } else {
+                is_simple = false;
+                substructure = combine_substructure(cs_clone);
             }
-            _ => cx.dcx().span_bug(span, "`#[derive(Clone)]` on wrong item kind"),
-        },
-
-        _ => cx.dcx().span_bug(span, "`#[derive(Clone)]` on trait item or impl item"),
+        }
+        ItemKind::Union(..) => {
+            bounds = smallvec![Path(path_std!(marker::Copy))];
+            is_simple = true;
+            substructure = combine_substructure(|c, s, sub| cs_clone_simple(c, s, sub, true));
+        }
+        _ => cx.dcx().span_bug(span, "`#[derive(Clone)]` on wrong item kind"),
     }
 
     // If the clone method is just copying the value, also mark the type as
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
index 440360ca85d7d..0df5767e2bde0 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
@@ -12,7 +12,7 @@ pub(crate) fn expand_deriving_eq(
     cx: &ExtCtxt<'_>,
     span: Span,
     mitem: &MetaItem,
-    item: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     is_const: bool,
 ) {
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs
index a1b38ceadb228..84e5485020a1f 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs
@@ -11,7 +11,7 @@ pub(crate) fn expand_deriving_ord(
     cx: &ExtCtxt<'_>,
     span: Span,
     mitem: &MetaItem,
-    item: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     is_const: bool,
 ) {
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
index b852e29b03ca4..fb3d6e9b338f7 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
@@ -13,7 +13,7 @@ pub(crate) fn expand_deriving_partial_eq(
     cx: &ExtCtxt<'_>,
     span: Span,
     mitem: &MetaItem,
-    item: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     is_const: bool,
 ) {
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs
index 88141224fddc2..8b778a014ade0 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs
@@ -11,7 +11,7 @@ pub(crate) fn expand_deriving_partial_ord(
     cx: &ExtCtxt<'_>,
     span: Span,
     mitem: &MetaItem,
-    item: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     is_const: bool,
 ) {
@@ -20,9 +20,7 @@ pub(crate) fn expand_deriving_partial_ord(
         Path(Path::new_(pathvec!(option::Option), vec![Box::new(ordering_ty)], PathKind::Std));
 
     // Order in which to perform matching
-    let discr_then_data = if let Annotatable::Item(item) = item
-        && let ItemKind::Enum(_, _, def) = &item.kind
-    {
+    let discr_then_data = if let ItemKind::Enum(_, _, def) = &item.kind {
         let dataful: Vec<bool> = def.variants.iter().map(|v| !v.data.fields().is_empty()).collect();
         match dataful.iter().filter(|&&b| b).count() {
             // No data, placing the discriminant check first makes codegen simpler
@@ -49,29 +47,26 @@ pub(crate) fn expand_deriving_partial_ord(
     let simple_substructure = combine_substructure(|cx, span, _| {
         cs_partial_cmp_simple(cx, span, cx.expr_ident(span, Ident::new(sym::other, span)))
     });
-    let is_simple = match item {
-        Annotatable::Item(annitem) => match &annitem.kind {
-            // For unit structs/zero-variant enums, the default generated code is better.
-            ItemKind::Struct(.., ast::VariantData::Unit(..)) => false,
-            // Also for single fieldless variant enum
-            ItemKind::Enum(.., enum_def) if enum_def.variants.is_empty() => false,
-            ItemKind::Enum(.., enum_def)
-                if enum_def.variants.len() == 1
-                    && matches!(enum_def.variants[0].data, ast::VariantData::Unit(..)) =>
-            {
-                false
-            }
-            ItemKind::Struct(_, ast::Generics { params, .. }, _)
-            | ItemKind::Enum(_, ast::Generics { params, .. }, _)
-                if has_derive_ord
-                    && !params
-                        .iter()
-                        .any(|param| matches!(param.kind, ast::GenericParamKind::Type { .. })) =>
-            {
-                true
-            }
-            _ => false,
-        },
+    let is_simple = match &item.kind {
+        // For unit structs/zero-variant enums, the default generated code is better.
+        ItemKind::Struct(.., ast::VariantData::Unit(..)) => false,
+        // Also for single fieldless variant enum
+        ItemKind::Enum(.., enum_def) if enum_def.variants.is_empty() => false,
+        ItemKind::Enum(.., enum_def)
+            if enum_def.variants.len() == 1
+                && matches!(enum_def.variants[0].data, ast::VariantData::Unit(..)) =>
+        {
+            false
+        }
+        ItemKind::Struct(_, ast::Generics { params, .. }, _)
+        | ItemKind::Enum(_, ast::Generics { params, .. }, _)
+            if has_derive_ord
+                && !params
+                    .iter()
+                    .any(|param| matches!(param.kind, ast::GenericParamKind::Type { .. })) =>
+        {
+            true
+        }
         _ => false,
     };
 
diff --git a/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs b/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs
index 80296a43ee490..a18af8e035c68 100644
--- a/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs
@@ -1,6 +1,6 @@
 use ast::HasAttrs;
 use rustc_ast::mut_visit::MutVisitor;
-use rustc_ast::visit::BoundKind;
+use rustc_ast::visit::{BoundKind, Visitor};
 use rustc_ast::{
     self as ast, GenericArg, GenericBound, GenericParamKind, Generics, ItemKind, MetaItem,
     TraitBoundModifiers, VariantData, WherePredicate,
@@ -22,15 +22,13 @@ pub(crate) fn expand_deriving_coerce_pointee(
     cx: &ExtCtxt<'_>,
     span: Span,
     _mitem: &MetaItem,
-    item: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     _is_const: bool,
 ) {
-    item.visit_with(&mut DetectNonGenericPointeeAttr { cx });
+    DetectNonGenericPointeeAttr { cx }.visit_item(item);
 
-    let (name_ident, generics) = if let Annotatable::Item(aitem) = item
-        && let ItemKind::Struct(ident, g, struct_data) = &aitem.kind
-    {
+    let (name_ident, generics) = if let ItemKind::Struct(ident, g, struct_data) = &item.kind {
         if !matches!(
             struct_data,
             VariantData::Struct { fields, recovered: _ } | VariantData::Tuple(fields, _)
diff --git a/compiler/rustc_builtin_macros/src/deriving/debug.rs b/compiler/rustc_builtin_macros/src/deriving/debug.rs
index c09ac52e74820..0b2fed5ce4947 100644
--- a/compiler/rustc_builtin_macros/src/deriving/debug.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/debug.rs
@@ -12,7 +12,7 @@ pub(crate) fn expand_deriving_debug(
     cx: &ExtCtxt<'_>,
     span: Span,
     mitem: &MetaItem,
-    item: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     is_const: bool,
 ) {
diff --git a/compiler/rustc_builtin_macros/src/deriving/default.rs b/compiler/rustc_builtin_macros/src/deriving/default.rs
index 3e4c5f1dcfa53..4293c89d15f96 100644
--- a/compiler/rustc_builtin_macros/src/deriving/default.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/default.rs
@@ -1,6 +1,6 @@
 use core::ops::ControlFlow;
 
-use rustc_ast::visit::visit_opt;
+use rustc_ast::visit::{Visitor, visit_opt};
 use rustc_ast::{self as ast, EnumDef, Safety, VariantData, attr};
 use rustc_expand::base::{Annotatable, DummyResult, ExtCtxt};
 use rustc_span::{ErrorGuaranteed, Ident, Span, kw, sym};
@@ -15,11 +15,11 @@ pub(crate) fn expand_deriving_default(
     cx: &ExtCtxt<'_>,
     span: Span,
     mitem: &ast::MetaItem,
-    item: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     is_const: bool,
 ) {
-    item.visit_with(&mut DetectNonVariantDefaultAttr { cx });
+    DetectNonVariantDefaultAttr { cx }.visit_item(item);
 
     let trait_def = TraitDef {
         span,
@@ -42,7 +42,7 @@ pub(crate) fn expand_deriving_default(
                         default_struct_substructure(cx, trait_span, substr, fields)
                     }
                     StaticEnum(enum_def) => {
-                        default_enum_substructure(cx, trait_span, enum_def, item.span())
+                        default_enum_substructure(cx, trait_span, enum_def, item.span)
                     }
                     _ => cx.dcx().span_bug(trait_span, "method in `derive(Default)`"),
                 }
@@ -308,7 +308,7 @@ impl<'a, 'b> rustc_ast::visit::Visitor<'a> for DetectNonVariantDefaultAttr<'a, '
     }
 }
 
-fn has_a_default_variant(item: &Annotatable) -> bool {
+fn has_a_default_variant(item: &ast::Item) -> bool {
     struct HasDefaultAttrOnVariant;
 
     impl<'ast> rustc_ast::visit::Visitor<'ast> for HasDefaultAttrOnVariant {
@@ -323,5 +323,5 @@ fn has_a_default_variant(item: &Annotatable) -> bool {
         }
     }
 
-    item.visit_with(&mut HasDefaultAttrOnVariant).is_break()
+    HasDefaultAttrOnVariant.visit_item(item).is_break()
 }
diff --git a/compiler/rustc_builtin_macros/src/deriving/from.rs b/compiler/rustc_builtin_macros/src/deriving/from.rs
index 9824ab5a225b7..4f7d7fe15b616 100644
--- a/compiler/rustc_builtin_macros/src/deriving/from.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/from.rs
@@ -16,14 +16,10 @@ pub(crate) fn expand_deriving_from(
     cx: &ExtCtxt<'_>,
     span: Span,
     mitem: &ast::MetaItem,
-    annotatable: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     is_const: bool,
 ) {
-    let Annotatable::Item(item) = &annotatable else {
-        cx.dcx().bug("derive(From) used on something else than an item");
-    };
-
     let err_span = || {
         let item_span = item.kind.ident().map(|ident| ident.span).unwrap_or(item.span);
         MultiSpan::from_spans(vec![span, item_span])
@@ -127,5 +123,5 @@ pub(crate) fn expand_deriving_from(
         document: true,
     };
 
-    from_trait_def.expand(cx, mitem, annotatable, push);
+    from_trait_def.expand(cx, mitem, item, push);
 }
diff --git a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
index 6a53dafd396df..cfd336fafc4a9 100644
--- a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
@@ -179,10 +179,11 @@ use std::{iter, vec};
 
 pub(crate) use StaticFields::*;
 pub(crate) use SubstructureFields::*;
+pub(crate) use rustc_ast as ast;
 use rustc_ast::token::{IdentIsRaw, LitKind, Token, TokenKind};
 use rustc_ast::tokenstream::{DelimSpan, Spacing, TokenTree};
 use rustc_ast::{
-    self as ast, AnonConst, AttrArgs, BindingMode, ByRef, DelimArgs, EnumDef, Expr, GenericArg,
+    AnonConst, AttrArgs, BindingMode, ByRef, DelimArgs, EnumDef, Expr, GenericArg,
     GenericParamKind, Generics, Mutability, PatKind, Safety, SelfKind, VariantData,
 };
 use rustc_attr_ir::{Attribute, AttributeKind, ReprPacked};
@@ -473,7 +474,7 @@ impl<'a> TraitDef<'a> {
         self,
         cx: &ExtCtxt<'_>,
         mitem: &ast::MetaItem,
-        item: &'a Annotatable,
+        item: &'a ast::Item,
         push: &mut dyn FnMut(Annotatable),
     ) {
         self.expand_ext(cx, mitem, item, push, false);
@@ -483,72 +484,62 @@ impl<'a> TraitDef<'a> {
         self,
         cx: &ExtCtxt<'_>,
         mitem: &ast::MetaItem,
-        item: &'a Annotatable,
+        item: &'a ast::Item,
         push: &mut dyn FnMut(Annotatable),
         from_scratch: bool,
     ) {
-        match item {
-            Annotatable::Item(item) => {
-                let is_packed = matches!(
-                    AttributeParser::parse_limited_sym(cx.sess, &item.attrs, &[sym::repr]),
-                    Some(Attribute::Parsed(AttributeKind::Repr { reprs, .. })) if reprs.iter().any(|(x, _)| matches!(x, ReprPacked(..)))
-                );
+        let is_packed = matches!(
+            AttributeParser::parse_limited_sym(cx.sess, &item.attrs, &[sym::repr]),
+            Some(Attribute::Parsed(AttributeKind::Repr { reprs, .. })) if reprs.iter().any(|(x, _)| matches!(x, ReprPacked(..)))
+        );
 
-                let mut newitem = match &item.kind {
-                    ast::ItemKind::Struct(ident, generics, struct_def) => self.expand_struct_def(
+        let mut newitem = match &item.kind {
+            ast::ItemKind::Struct(ident, generics, struct_def) => {
+                self.expand_struct_def(cx, struct_def, *ident, generics, from_scratch, is_packed)
+            }
+            ast::ItemKind::Enum(ident, generics, enum_def) => {
+                // We ignore `is_packed` here, because `repr(packed)`
+                // enums cause an error later on.
+                //
+                // This can only cause further compilation errors
+                // downstream in blatantly illegal code, so it is fine.
+                self.expand_enum_def(cx, enum_def, *ident, generics, from_scratch)
+            }
+            ast::ItemKind::Union(ident, generics, struct_def) => {
+                if self.supports_unions {
+                    self.expand_struct_def(
                         cx,
                         struct_def,
                         *ident,
                         generics,
                         from_scratch,
                         is_packed,
-                    ),
-                    ast::ItemKind::Enum(ident, generics, enum_def) => {
-                        // We ignore `is_packed` here, because `repr(packed)`
-                        // enums cause an error later on.
-                        //
-                        // This can only cause further compilation errors
-                        // downstream in blatantly illegal code, so it is fine.
-                        self.expand_enum_def(cx, enum_def, *ident, generics, from_scratch)
-                    }
-                    ast::ItemKind::Union(ident, generics, struct_def) => {
-                        if self.supports_unions {
-                            self.expand_struct_def(
-                                cx,
-                                struct_def,
-                                *ident,
-                                generics,
-                                from_scratch,
-                                is_packed,
-                            )
-                        } else {
-                            cx.dcx().emit_err(diagnostics::DeriveUnion { span: mitem.span });
-                            return;
-                        }
-                    }
-                    _ => unreachable!(),
-                };
-                // Keep the lint attributes of the previous item to control how the
-                // generated implementations are linted
-                newitem.attrs.extend(
-                    item.attrs
-                        .iter()
-                        .filter(|a| {
-                            a.has_any_name(&[
-                                sym::allow,
-                                sym::warn,
-                                sym::deny,
-                                sym::forbid,
-                                sym::stable,
-                                sym::unstable,
-                            ])
-                        })
-                        .cloned(),
-                );
-                push(Annotatable::Item(newitem))
+                    )
+                } else {
+                    cx.dcx().emit_err(diagnostics::DeriveUnion { span: mitem.span });
+                    return;
+                }
             }
             _ => unreachable!(),
-        }
+        };
+        // Keep the lint attributes of the previous item to control how the
+        // generated implementations are linted
+        newitem.attrs.extend(
+            item.attrs
+                .iter()
+                .filter(|a| {
+                    a.has_any_name(&[
+                        sym::allow,
+                        sym::warn,
+                        sym::deny,
+                        sym::forbid,
+                        sym::stable,
+                        sym::unstable,
+                    ])
+                })
+                .cloned(),
+        );
+        push(Annotatable::Item(newitem))
     }
 
     /// Given that we are deriving a trait `DerivedTrait` for a type like:
diff --git a/compiler/rustc_builtin_macros/src/deriving/hash.rs b/compiler/rustc_builtin_macros/src/deriving/hash.rs
index f1931aa90a435..5e32a12b6fdca 100644
--- a/compiler/rustc_builtin_macros/src/deriving/hash.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/hash.rs
@@ -11,7 +11,7 @@ pub(crate) fn expand_deriving_hash(
     cx: &ExtCtxt<'_>,
     span: Span,
     mitem: &MetaItem,
-    item: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     is_const: bool,
 ) {
diff --git a/compiler/rustc_builtin_macros/src/deriving/mod.rs b/compiler/rustc_builtin_macros/src/deriving/mod.rs
index 602af919bd4f2..55838e09b304b 100644
--- a/compiler/rustc_builtin_macros/src/deriving/mod.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/mod.rs
@@ -35,7 +35,7 @@ pub(crate) mod partial_ord;
 pub(crate) mod generic;
 
 pub(crate) type BuiltinDeriveFn =
-    fn(&ExtCtxt<'_>, Span, &MetaItem, &Annotatable, &mut dyn FnMut(Annotatable), bool);
+    fn(&ExtCtxt<'_>, Span, &MetaItem, &ast::Item, &mut dyn FnMut(Annotatable), bool);
 
 pub(crate) struct BuiltinDerive(pub(crate) BuiltinDeriveFn);
 
@@ -59,7 +59,7 @@ impl MultiItemModifier for BuiltinDerive {
                         ecx,
                         span,
                         meta_item,
-                        &Annotatable::Item(item),
+                        &item,
                         &mut |a| {
                             // Cannot use 'ecx.stmt_item' here, because we need to pass 'ecx'
                             // to the function
@@ -75,9 +75,10 @@ impl MultiItemModifier for BuiltinDerive {
                     unreachable!("should have already errored on non-item statement")
                 }
             }
-            _ => {
-                (self.0)(ecx, span, meta_item, &item, &mut |a| items.push(a), is_derive_const);
+            Annotatable::Item(item) => {
+                (self.0)(ecx, span, meta_item, &item, &mut |a| items.push(a), is_derive_const)
             }
+            _ => unreachable!(),
         }
         ExpandResult::Ready(items)
     }
diff --git a/compiler/rustc_builtin_macros/src/deriving/reborrow.rs b/compiler/rustc_builtin_macros/src/deriving/reborrow.rs
index 9dc1ccf4fd8e6..c1b8dfb53c694 100644
--- a/compiler/rustc_builtin_macros/src/deriving/reborrow.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/reborrow.rs
@@ -15,7 +15,7 @@ pub(crate) fn expand_deriving_reborrow(
     cx: &ExtCtxt<'_>,
     span: Span,
     _mitem: &MetaItem,
-    item: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     _is_const: bool,
 ) {
@@ -30,7 +30,7 @@ pub(crate) fn expand_deriving_coerce_shared(
     cx: &ExtCtxt<'_>,
     span: Span,
     _mitem: &MetaItem,
-    item: &Annotatable,
+    item: &ast::Item,
     push: &mut dyn FnMut(Annotatable),
     _is_const: bool,
 ) {
@@ -55,25 +55,19 @@ pub(crate) fn expand_deriving_coerce_shared(
 fn struct_def<'a>(
     cx: &ExtCtxt<'_>,
     span: Span,
-    item: &'a Annotatable,
+    item: &'a ast::Item,
     trait_name: Symbol,
 ) -> Option<(Ident, &'a Generics)> {
-    match item {
-        Annotatable::Item(item) => match &item.kind {
-            ItemKind::Struct(ident, generics, _) => Some((*ident, generics)),
-            ItemKind::Enum(..) => {
-                cx.dcx().emit_err(UnsupportedItem { span, trait_name, kind: "enum" });
-                None
-            }
-            ItemKind::Union(..) => {
-                cx.dcx().emit_err(UnsupportedItem { span, trait_name, kind: "union" });
-                None
-            }
-            _ => {
-                cx.dcx().emit_err(UnsupportedItem { span, trait_name, kind: "item" });
-                None
-            }
-        },
+    match &item.kind {
+        ItemKind::Struct(ident, generics, _) => Some((*ident, generics)),
+        ItemKind::Enum(..) => {
+            cx.dcx().emit_err(UnsupportedItem { span, trait_name, kind: "enum" });
+            None
+        }
+        ItemKind::Union(..) => {
+            cx.dcx().emit_err(UnsupportedItem { span, trait_name, kind: "union" });
+            None
+        }
         _ => {
             cx.dcx().emit_err(UnsupportedItem { span, trait_name, kind: "item" });
             None
@@ -81,12 +75,7 @@ fn struct_def<'a>(
     }
 }
 
-fn coerce_shared_target(cx: &ExtCtxt<'_>, span: Span, item: &Annotatable) -> Option<Box<ast::Ty>> {
-    let Annotatable::Item(item) = item else {
-        cx.dcx().emit_err(MissingTarget { span });
-        return None;
-    };
-
+fn coerce_shared_target(cx: &ExtCtxt<'_>, span: Span, item: &ast::Item) -> Option<Box<ast::Ty>> {
     let mut attrs = item.attrs.iter().filter(|attr| attr.has_name(sym::coerce_shared));
     let Some(attr) = attrs.next() else {
         cx.dcx().emit_err(MissingTarget { span });

From 04b8e09c9859f30a9a39858c17e3171bbe7c4775 Mon Sep 17 00:00:00 2001
From: cyrgani <ansgar.w.zielke@gmail.com>
Date: Mon, 24 Aug 2026 13:11:46 +0000
Subject: [PATCH 2/8] take `Box<Item>` instead of `Annotatable` as the `push`
 argument

---
 .../rustc_builtin_macros/src/deriving/bounds.rs   |  6 +++---
 .../rustc_builtin_macros/src/deriving/clone.rs    |  4 ++--
 .../rustc_builtin_macros/src/deriving/cmp/eq.rs   |  4 ++--
 .../rustc_builtin_macros/src/deriving/cmp/ord.rs  |  4 ++--
 .../src/deriving/cmp/partial_eq.rs                |  4 ++--
 .../src/deriving/cmp/partial_ord.rs               |  4 ++--
 .../src/deriving/coerce_pointee.rs                | 10 +++++-----
 .../rustc_builtin_macros/src/deriving/debug.rs    |  4 ++--
 .../rustc_builtin_macros/src/deriving/default.rs  |  4 ++--
 .../rustc_builtin_macros/src/deriving/from.rs     |  4 ++--
 .../src/deriving/generic/mod.rs                   |  8 ++++----
 .../rustc_builtin_macros/src/deriving/hash.rs     |  4 ++--
 compiler/rustc_builtin_macros/src/deriving/mod.rs | 15 ++++++++++-----
 .../rustc_builtin_macros/src/deriving/reborrow.rs | 12 ++++++------
 14 files changed, 46 insertions(+), 41 deletions(-)

diff --git a/compiler/rustc_builtin_macros/src/deriving/bounds.rs b/compiler/rustc_builtin_macros/src/deriving/bounds.rs
index 5b71d38c63e2e..da5370e3e7819 100644
--- a/compiler/rustc_builtin_macros/src/deriving/bounds.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/bounds.rs
@@ -1,5 +1,5 @@
 use rustc_ast::{MetaItem, Safety};
-use rustc_expand::base::{Annotatable, ExtCtxt};
+use rustc_expand::base::ExtCtxt;
 use rustc_span::Span;
 
 use crate::deriving::generic::*;
@@ -10,7 +10,7 @@ pub(crate) fn expand_deriving_copy(
     span: Span,
     mitem: &MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     is_const: bool,
 ) {
     let trait_def = TraitDef {
@@ -35,7 +35,7 @@ pub(crate) fn expand_deriving_const_param_ty(
     span: Span,
     mitem: &MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     is_const: bool,
 ) {
     let trait_def = TraitDef {
diff --git a/compiler/rustc_builtin_macros/src/deriving/clone.rs b/compiler/rustc_builtin_macros/src/deriving/clone.rs
index be70cf0b584a1..f0c274bce5b58 100644
--- a/compiler/rustc_builtin_macros/src/deriving/clone.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/clone.rs
@@ -1,6 +1,6 @@
 use rustc_ast::{self as ast, Generics, ItemKind, MetaItem, Safety, VariantData};
 use rustc_data_structures::fx::FxHashSet;
-use rustc_expand::base::{Annotatable, ExtCtxt};
+use rustc_expand::base::ExtCtxt;
 use rustc_span::{DUMMY_SP, Ident, Span, kw, sym};
 use thin_vec::{ThinVec, thin_vec};
 
@@ -13,7 +13,7 @@ pub(crate) fn expand_deriving_clone(
     span: Span,
     mitem: &MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     is_const: bool,
 ) {
     // The simple form is `fn clone(&self) -> Self { *self }`, possibly with
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
index 0df5767e2bde0..8c160cb9868bf 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
@@ -1,6 +1,6 @@
 use rustc_ast::{self as ast, MetaItem, Safety};
 use rustc_data_structures::fx::FxHashSet;
-use rustc_expand::base::{Annotatable, ExtCtxt};
+use rustc_expand::base::ExtCtxt;
 use rustc_span::{Span, sym};
 use thin_vec::{ThinVec, thin_vec};
 
@@ -13,7 +13,7 @@ pub(crate) fn expand_deriving_eq(
     span: Span,
     mitem: &MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     is_const: bool,
 ) {
     let span = cx.with_def_site_ctxt(span);
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs
index 84e5485020a1f..fb8d425841722 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs
@@ -1,5 +1,5 @@
 use rustc_ast::{MetaItem, Safety};
-use rustc_expand::base::{Annotatable, ExtCtxt};
+use rustc_expand::base::ExtCtxt;
 use rustc_span::{Ident, Span, sym};
 use thin_vec::thin_vec;
 
@@ -12,7 +12,7 @@ pub(crate) fn expand_deriving_ord(
     span: Span,
     mitem: &MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     is_const: bool,
 ) {
     let trait_def = TraitDef {
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
index fb3d6e9b338f7..8c442f7dbaa5f 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
@@ -1,5 +1,5 @@
 use rustc_ast::{BinOpKind, BorrowKind, Expr, ExprKind, MetaItem, Mutability, Safety};
-use rustc_expand::base::{Annotatable, ExtCtxt};
+use rustc_expand::base::ExtCtxt;
 use rustc_span::{Span, sym};
 use thin_vec::thin_vec;
 
@@ -14,7 +14,7 @@ pub(crate) fn expand_deriving_partial_eq(
     span: Span,
     mitem: &MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     is_const: bool,
 ) {
     let structural_trait_def = TraitDef {
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs
index 8b778a014ade0..0e547d441a74b 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs
@@ -1,5 +1,5 @@
 use rustc_ast::{ExprKind, ItemKind, MetaItem, PatKind, Safety, ast};
-use rustc_expand::base::{Annotatable, ExtCtxt};
+use rustc_expand::base::ExtCtxt;
 use rustc_span::{Ident, Span, sym};
 use thin_vec::thin_vec;
 
@@ -12,7 +12,7 @@ pub(crate) fn expand_deriving_partial_ord(
     span: Span,
     mitem: &MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     is_const: bool,
 ) {
     let ordering_ty = Path(path_std!(cmp::Ordering));
diff --git a/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs b/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs
index a18af8e035c68..58b4734b132c3 100644
--- a/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs
@@ -7,7 +7,7 @@ use rustc_ast::{
 };
 use rustc_data_structures::flat_map_in_place::FlatMapInPlace;
 use rustc_errors::E0802;
-use rustc_expand::base::{Annotatable, ExtCtxt};
+use rustc_expand::base::ExtCtxt;
 use rustc_macros::Diagnostic;
 use rustc_span::{Ident, Span, Symbol, sym};
 use thin_vec::{ThinVec, thin_vec};
@@ -23,7 +23,7 @@ pub(crate) fn expand_deriving_coerce_pointee(
     span: Span,
     _mitem: &MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     _is_const: bool,
 ) {
     DetectNonGenericPointeeAttr { cx }.visit_item(item);
@@ -102,7 +102,7 @@ pub(crate) fn expand_deriving_coerce_pointee(
         let trait_path =
             cx.path_all(span, true, path!(span, core::marker::CoercePointeeValidated), vec![]);
         let trait_ref = cx.trait_ref(trait_path);
-        push(Annotatable::Item(
+        push(
             cx.item(
                 span,
                 attrs.clone(),
@@ -142,7 +142,7 @@ pub(crate) fn expand_deriving_coerce_pointee(
                     items: ThinVec::new(),
                 }),
             ),
-        ));
+        );
     }
     let mut add_impl_block = |generics, trait_symbol, trait_args| {
         let mut parts = path!(span, core::ops);
@@ -165,7 +165,7 @@ pub(crate) fn expand_deriving_coerce_pointee(
                 items: ThinVec::new(),
             }),
         );
-        push(Annotatable::Item(item));
+        push(item);
     };
 
     // Create unsized `self`, that is, one where the `#[pointee]` type arg is replaced with `__S`. For
diff --git a/compiler/rustc_builtin_macros/src/deriving/debug.rs b/compiler/rustc_builtin_macros/src/deriving/debug.rs
index 0b2fed5ce4947..f31dfe65d01ed 100644
--- a/compiler/rustc_builtin_macros/src/deriving/debug.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/debug.rs
@@ -1,5 +1,5 @@
 use rustc_ast::{self as ast, EnumDef, ExprKind, MetaItem, Safety, TyKind, token};
-use rustc_expand::base::{Annotatable, ExtCtxt};
+use rustc_expand::base::ExtCtxt;
 use rustc_session::config::FmtDebug;
 use rustc_span::{Ident, Span, Symbol, sym};
 use thin_vec::{ThinVec, thin_vec};
@@ -13,7 +13,7 @@ pub(crate) fn expand_deriving_debug(
     span: Span,
     mitem: &MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     is_const: bool,
 ) {
     // &mut ::std::fmt::Formatter
diff --git a/compiler/rustc_builtin_macros/src/deriving/default.rs b/compiler/rustc_builtin_macros/src/deriving/default.rs
index 4293c89d15f96..88e9d8daf1bd9 100644
--- a/compiler/rustc_builtin_macros/src/deriving/default.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/default.rs
@@ -2,7 +2,7 @@ use core::ops::ControlFlow;
 
 use rustc_ast::visit::{Visitor, visit_opt};
 use rustc_ast::{self as ast, EnumDef, Safety, VariantData, attr};
-use rustc_expand::base::{Annotatable, DummyResult, ExtCtxt};
+use rustc_expand::base::{DummyResult, ExtCtxt};
 use rustc_span::{ErrorGuaranteed, Ident, Span, kw, sym};
 use smallvec::SmallVec;
 use thin_vec::{ThinVec, thin_vec};
@@ -16,7 +16,7 @@ pub(crate) fn expand_deriving_default(
     span: Span,
     mitem: &ast::MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     is_const: bool,
 ) {
     DetectNonVariantDefaultAttr { cx }.visit_item(item);
diff --git a/compiler/rustc_builtin_macros/src/deriving/from.rs b/compiler/rustc_builtin_macros/src/deriving/from.rs
index 4f7d7fe15b616..ab5008f90ff00 100644
--- a/compiler/rustc_builtin_macros/src/deriving/from.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/from.rs
@@ -1,7 +1,7 @@
 use rustc_ast as ast;
 use rustc_ast::{ItemKind, Safety, VariantData};
 use rustc_errors::MultiSpan;
-use rustc_expand::base::{Annotatable, DummyResult, ExtCtxt};
+use rustc_expand::base::{DummyResult, ExtCtxt};
 use rustc_span::{Ident, Span, kw, sym};
 use thin_vec::thin_vec;
 
@@ -17,7 +17,7 @@ pub(crate) fn expand_deriving_from(
     span: Span,
     mitem: &ast::MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     is_const: bool,
 ) {
     let err_span = || {
diff --git a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
index cfd336fafc4a9..436881dbf2209 100644
--- a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
@@ -188,7 +188,7 @@ use rustc_ast::{
 };
 use rustc_attr_ir::{Attribute, AttributeKind, ReprPacked};
 use rustc_attr_parsing::AttributeParser;
-use rustc_expand::base::{Annotatable, ExtCtxt};
+use rustc_expand::base::ExtCtxt;
 use rustc_span::{DUMMY_SP, Ident, Span, Symbol, kw, respan, sym};
 pub(crate) use smallvec::{SmallVec, smallvec};
 use thin_vec::{ThinVec, thin_vec};
@@ -475,7 +475,7 @@ impl<'a> TraitDef<'a> {
         cx: &ExtCtxt<'_>,
         mitem: &ast::MetaItem,
         item: &'a ast::Item,
-        push: &mut dyn FnMut(Annotatable),
+        push: &mut dyn FnMut(Box<ast::Item>),
     ) {
         self.expand_ext(cx, mitem, item, push, false);
     }
@@ -485,7 +485,7 @@ impl<'a> TraitDef<'a> {
         cx: &ExtCtxt<'_>,
         mitem: &ast::MetaItem,
         item: &'a ast::Item,
-        push: &mut dyn FnMut(Annotatable),
+        push: &mut dyn FnMut(Box<ast::Item>),
         from_scratch: bool,
     ) {
         let is_packed = matches!(
@@ -539,7 +539,7 @@ impl<'a> TraitDef<'a> {
                 })
                 .cloned(),
         );
-        push(Annotatable::Item(newitem))
+        push(newitem);
     }
 
     /// Given that we are deriving a trait `DerivedTrait` for a type like:
diff --git a/compiler/rustc_builtin_macros/src/deriving/hash.rs b/compiler/rustc_builtin_macros/src/deriving/hash.rs
index 5e32a12b6fdca..6864b05ae08cd 100644
--- a/compiler/rustc_builtin_macros/src/deriving/hash.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/hash.rs
@@ -1,5 +1,5 @@
 use rustc_ast::{MetaItem, Mutability, Safety};
-use rustc_expand::base::{Annotatable, ExtCtxt};
+use rustc_expand::base::ExtCtxt;
 use rustc_span::{Span, sym};
 use thin_vec::thin_vec;
 
@@ -12,7 +12,7 @@ pub(crate) fn expand_deriving_hash(
     span: Span,
     mitem: &MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     is_const: bool,
 ) {
     let path = path_std!(hash::Hash);
diff --git a/compiler/rustc_builtin_macros/src/deriving/mod.rs b/compiler/rustc_builtin_macros/src/deriving/mod.rs
index 55838e09b304b..7c010f62bfd15 100644
--- a/compiler/rustc_builtin_macros/src/deriving/mod.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/mod.rs
@@ -35,7 +35,7 @@ pub(crate) mod partial_ord;
 pub(crate) mod generic;
 
 pub(crate) type BuiltinDeriveFn =
-    fn(&ExtCtxt<'_>, Span, &MetaItem, &ast::Item, &mut dyn FnMut(Annotatable), bool);
+    fn(&ExtCtxt<'_>, Span, &MetaItem, &ast::Item, &mut dyn FnMut(Box<ast::Item>), bool);
 
 pub(crate) struct BuiltinDerive(pub(crate) BuiltinDeriveFn);
 
@@ -65,7 +65,7 @@ impl MultiItemModifier for BuiltinDerive {
                             // to the function
                             items.push(Annotatable::Stmt(Box::new(ast::Stmt {
                                 id: ast::DUMMY_NODE_ID,
-                                kind: ast::StmtKind::Item(a.expect_item()),
+                                kind: ast::StmtKind::Item(a),
                                 span,
                             })));
                         },
@@ -75,9 +75,14 @@ impl MultiItemModifier for BuiltinDerive {
                     unreachable!("should have already errored on non-item statement")
                 }
             }
-            Annotatable::Item(item) => {
-                (self.0)(ecx, span, meta_item, &item, &mut |a| items.push(a), is_derive_const)
-            }
+            Annotatable::Item(item) => (self.0)(
+                ecx,
+                span,
+                meta_item,
+                &item,
+                &mut |a| items.push(Annotatable::Item(a)),
+                is_derive_const,
+            ),
             _ => unreachable!(),
         }
         ExpandResult::Ready(items)
diff --git a/compiler/rustc_builtin_macros/src/deriving/reborrow.rs b/compiler/rustc_builtin_macros/src/deriving/reborrow.rs
index c1b8dfb53c694..43d24417acc00 100644
--- a/compiler/rustc_builtin_macros/src/deriving/reborrow.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/reborrow.rs
@@ -2,7 +2,7 @@ use rustc_ast::{
     self as ast, AttrArgs, GenericArg, GenericParamKind, Generics, ItemKind, MetaItem, token,
 };
 use rustc_errors::E0802;
-use rustc_expand::base::{Annotatable, ExtCtxt};
+use rustc_expand::base::ExtCtxt;
 use rustc_macros::Diagnostic;
 use rustc_span::{Ident, Span, Symbol, sym};
 use thin_vec::ThinVec;
@@ -16,7 +16,7 @@ pub(crate) fn expand_deriving_reborrow(
     span: Span,
     _mitem: &MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     _is_const: bool,
 ) {
     let Some((ident, generics)) = struct_def(cx, span, item, sym::Reborrow) else {
@@ -31,7 +31,7 @@ pub(crate) fn expand_deriving_coerce_shared(
     span: Span,
     _mitem: &MetaItem,
     item: &ast::Item,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
     _is_const: bool,
 ) {
     let Some((ident, generics)) = struct_def(cx, span, item, sym::CoerceShared) else {
@@ -119,7 +119,7 @@ fn push_marker_impl(
     generics: &Generics,
     trait_name: Symbol,
     trait_args: Vec<GenericArg>,
-    push: &mut dyn FnMut(Annotatable),
+    push: &mut dyn FnMut(Box<ast::Item>),
 ) {
     let mut trait_parts = path!(span, core::marker);
     trait_parts.push(Ident::new(trait_name, span));
@@ -143,7 +143,7 @@ fn push_marker_impl(
         .collect();
     let self_ty = cx.ty_path(cx.path_all(span, false, vec![ident], self_params));
 
-    push(Annotatable::Item(cx.item(
+    push(cx.item(
         span,
         thin_vec::thin_vec![cx.attr_word(sym::automatically_derived, span)],
         ast::ItemKind::Impl(ast::Impl {
@@ -158,7 +158,7 @@ fn push_marker_impl(
             self_ty,
             items: ThinVec::new(),
         }),
-    )));
+    ));
 }
 
 fn impl_generics(cx: &ExtCtxt<'_>, generics: &Generics) -> Generics {

From 1343cc348e0fd6d16a67f1e6cb5ec16526f19ab1 Mon Sep 17 00:00:00 2001
From: cyrgani <ansgar.w.zielke@gmail.com>
Date: Wed, 26 Aug 2026 11:24:54 +0000
Subject: [PATCH 3/8] several small cleanups

---
 .../src/deriving/cmp/partial_eq.rs                   | 12 +++++-------
 compiler/rustc_builtin_macros/src/deriving/from.rs   |  2 +-
 compiler/rustc_builtin_macros/src/deriving/mod.rs    | 10 +---------
 3 files changed, 7 insertions(+), 17 deletions(-)

diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
index 8c442f7dbaa5f..a65962bfc9731 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
@@ -47,9 +47,7 @@ pub(crate) fn expand_deriving_partial_eq(
         ret_ty: Path(generic::ty::Path::new_local(sym::bool)),
         attributes: thin_vec![cx.attr_word(sym::inline, span)],
         fieldless_variants_strategy: FieldlessVariantsStrategy::Unify,
-        combine_substructure: combine_substructure(|a, b, c| {
-            BlockOrExpr::new_expr(get_substructure_equality_expr(a, b, c))
-        }),
+        combine_substructure: combine_substructure(get_substructure_equality_expr),
     }];
 
     let trait_def = TraitDef {
@@ -123,10 +121,10 @@ fn get_substructure_equality_expr(
     cx: &ExtCtxt<'_>,
     span: Span,
     substructure: &Substructure<'_>,
-) -> Box<Expr> {
+) -> BlockOrExpr {
     use SubstructureFields::*;
 
-    match substructure.fields {
+    BlockOrExpr::new_expr(match substructure.fields {
         EnumMatching(.., fields) | Struct(.., fields) => {
             let combine = move |acc, field| {
                 let rhs = get_field_equality_expr(cx, field);
@@ -151,7 +149,7 @@ fn get_substructure_equality_expr(
         EnumDiscr(disc, match_expr) => {
             let lhs = get_field_equality_expr(cx, disc);
             let Some(match_expr) = match_expr else {
-                return lhs;
+                return BlockOrExpr::new_expr(lhs);
             };
             // Compare the discriminant first (cheaper), then the rest of the
             // fields.
@@ -169,7 +167,7 @@ fn get_substructure_equality_expr(
             span,
             "unexpected all-fieldless enum encountered during `derive(PartialEq)` expansion",
         ),
-    }
+    })
 }
 
 /// Generates an equality comparison expression for a single struct or enum
diff --git a/compiler/rustc_builtin_macros/src/deriving/from.rs b/compiler/rustc_builtin_macros/src/deriving/from.rs
index ab5008f90ff00..0758ff0269a96 100644
--- a/compiler/rustc_builtin_macros/src/deriving/from.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/from.rs
@@ -75,7 +75,7 @@ pub(crate) fn expand_deriving_from(
         supports_unions: false,
         methods: smallvec![MethodDef {
             name: sym::from,
-            generics: Bounds { bounds: vec![] },
+            generics: Bounds::empty(),
             explicit_self: false,
             nonself_args: smallvec![(from_type, sym::value)],
             ret_ty: Ty::Self_,
diff --git a/compiler/rustc_builtin_macros/src/deriving/mod.rs b/compiler/rustc_builtin_macros/src/deriving/mod.rs
index 7c010f62bfd15..75bd98893de80 100644
--- a/compiler/rustc_builtin_macros/src/deriving/mod.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/mod.rs
@@ -60,15 +60,7 @@ impl MultiItemModifier for BuiltinDerive {
                         span,
                         meta_item,
                         &item,
-                        &mut |a| {
-                            // Cannot use 'ecx.stmt_item' here, because we need to pass 'ecx'
-                            // to the function
-                            items.push(Annotatable::Stmt(Box::new(ast::Stmt {
-                                id: ast::DUMMY_NODE_ID,
-                                kind: ast::StmtKind::Item(a),
-                                span,
-                            })));
-                        },
+                        &mut |a| items.push(Annotatable::Stmt(Box::new(ecx.stmt_item(span, a)))),
                         is_derive_const,
                     );
                 } else {

From 9cde67f7c862c78d7796cb993fb9fb594fdf211e Mon Sep 17 00:00:00 2001
From: cyrgani <ansgar.w.zielke@gmail.com>
Date: Thu, 27 Aug 2026 10:02:57 +0000
Subject: [PATCH 4/8] remove one use of `expand_ext`

---
 compiler/rustc_builtin_macros/src/deriving/clone.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/rustc_builtin_macros/src/deriving/clone.rs b/compiler/rustc_builtin_macros/src/deriving/clone.rs
index f0c274bce5b58..f072b4b9e5cd1 100644
--- a/compiler/rustc_builtin_macros/src/deriving/clone.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/clone.rs
@@ -77,7 +77,7 @@ pub(crate) fn expand_deriving_clone(
             document: false,
         };
 
-        trivial_def.expand_ext(cx, mitem, item, push, true);
+        trivial_def.expand(cx, mitem, item, push);
     }
 
     let trait_def = TraitDef {

From 898fc7fb85c37c9234eb8826caaf9663fe83a649 Mon Sep 17 00:00:00 2001
From: cyrgani <ansgar.w.zielke@gmail.com>
Date: Thu, 27 Aug 2026 11:54:24 +0000
Subject: [PATCH 5/8] dissolve the `cmp` subdirectory

---
 .../rustc_builtin_macros/src/deriving/{cmp => }/eq.rs    | 0
 compiler/rustc_builtin_macros/src/deriving/mod.rs        | 9 ++-------
 .../rustc_builtin_macros/src/deriving/{cmp => }/ord.rs   | 0
 .../src/deriving/{cmp => }/partial_eq.rs                 | 0
 .../src/deriving/{cmp => }/partial_ord.rs                | 0
 5 files changed, 2 insertions(+), 7 deletions(-)
 rename compiler/rustc_builtin_macros/src/deriving/{cmp => }/eq.rs (100%)
 rename compiler/rustc_builtin_macros/src/deriving/{cmp => }/ord.rs (100%)
 rename compiler/rustc_builtin_macros/src/deriving/{cmp => }/partial_eq.rs (100%)
 rename compiler/rustc_builtin_macros/src/deriving/{cmp => }/partial_ord.rs (100%)

diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs b/compiler/rustc_builtin_macros/src/deriving/eq.rs
similarity index 100%
rename from compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
rename to compiler/rustc_builtin_macros/src/deriving/eq.rs
diff --git a/compiler/rustc_builtin_macros/src/deriving/mod.rs b/compiler/rustc_builtin_macros/src/deriving/mod.rs
index 75bd98893de80..337ee43938bd7 100644
--- a/compiler/rustc_builtin_macros/src/deriving/mod.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/mod.rs
@@ -19,18 +19,13 @@ pub(crate) mod clone;
 pub(crate) mod coerce_pointee;
 pub(crate) mod debug;
 pub(crate) mod default;
+pub(crate) mod eq;
 pub(crate) mod from;
 pub(crate) mod hash;
-pub(crate) mod reborrow;
-
-#[path = "cmp/eq.rs"]
-pub(crate) mod eq;
-#[path = "cmp/ord.rs"]
 pub(crate) mod ord;
-#[path = "cmp/partial_eq.rs"]
 pub(crate) mod partial_eq;
-#[path = "cmp/partial_ord.rs"]
 pub(crate) mod partial_ord;
+pub(crate) mod reborrow;
 
 pub(crate) mod generic;
 
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs b/compiler/rustc_builtin_macros/src/deriving/ord.rs
similarity index 100%
rename from compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs
rename to compiler/rustc_builtin_macros/src/deriving/ord.rs
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs b/compiler/rustc_builtin_macros/src/deriving/partial_eq.rs
similarity index 100%
rename from compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
rename to compiler/rustc_builtin_macros/src/deriving/partial_eq.rs
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs b/compiler/rustc_builtin_macros/src/deriving/partial_ord.rs
similarity index 100%
rename from compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs
rename to compiler/rustc_builtin_macros/src/deriving/partial_ord.rs

From 2e9a42802a20dc96162ff7109af592eff8d05bc4 Mon Sep 17 00:00:00 2001
From: cyrgani <ansgar.w.zielke@gmail.com>
Date: Thu, 27 Aug 2026 12:00:20 +0000
Subject: [PATCH 6/8] split `bounds` module into `const_param_ty` and `copy`
 modules

---
 .../deriving/{bounds.rs => const_param_ty.rs} | 25 ---------------
 .../rustc_builtin_macros/src/deriving/copy.rs | 31 +++++++++++++++++++
 .../rustc_builtin_macros/src/deriving/mod.rs  |  3 +-
 compiler/rustc_builtin_macros/src/lib.rs      |  4 +--
 4 files changed, 35 insertions(+), 28 deletions(-)
 rename compiler/rustc_builtin_macros/src/deriving/{bounds.rs => const_param_ty.rs} (56%)
 create mode 100644 compiler/rustc_builtin_macros/src/deriving/copy.rs

diff --git a/compiler/rustc_builtin_macros/src/deriving/bounds.rs b/compiler/rustc_builtin_macros/src/deriving/const_param_ty.rs
similarity index 56%
rename from compiler/rustc_builtin_macros/src/deriving/bounds.rs
rename to compiler/rustc_builtin_macros/src/deriving/const_param_ty.rs
index da5370e3e7819..18a9df86b547e 100644
--- a/compiler/rustc_builtin_macros/src/deriving/bounds.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/const_param_ty.rs
@@ -5,31 +5,6 @@ use rustc_span::Span;
 use crate::deriving::generic::*;
 use crate::deriving::path_std;
 
-pub(crate) fn expand_deriving_copy(
-    cx: &ExtCtxt<'_>,
-    span: Span,
-    mitem: &MetaItem,
-    item: &ast::Item,
-    push: &mut dyn FnMut(Box<ast::Item>),
-    is_const: bool,
-) {
-    let trait_def = TraitDef {
-        span,
-        path: path_std!(marker::Copy),
-        skip_path_as_bound: false,
-        needs_copy_as_bound_if_packed: false,
-        additional_bounds: SmallVec::new(),
-        supports_unions: true,
-        methods: SmallVec::new(),
-        associated_types: SmallVec::new(),
-        is_const,
-        safety: Safety::Default,
-        document: true,
-    };
-
-    trait_def.expand(cx, mitem, item, push);
-}
-
 pub(crate) fn expand_deriving_const_param_ty(
     cx: &ExtCtxt<'_>,
     span: Span,
diff --git a/compiler/rustc_builtin_macros/src/deriving/copy.rs b/compiler/rustc_builtin_macros/src/deriving/copy.rs
new file mode 100644
index 0000000000000..5743d27cf7458
--- /dev/null
+++ b/compiler/rustc_builtin_macros/src/deriving/copy.rs
@@ -0,0 +1,31 @@
+use rustc_ast::{MetaItem, Safety};
+use rustc_expand::base::ExtCtxt;
+use rustc_span::Span;
+
+use crate::deriving::generic::*;
+use crate::deriving::path_std;
+
+pub(crate) fn expand_deriving_copy(
+    cx: &ExtCtxt<'_>,
+    span: Span,
+    mitem: &MetaItem,
+    item: &ast::Item,
+    push: &mut dyn FnMut(Box<ast::Item>),
+    is_const: bool,
+) {
+    let trait_def = TraitDef {
+        span,
+        path: path_std!(marker::Copy),
+        skip_path_as_bound: false,
+        needs_copy_as_bound_if_packed: false,
+        additional_bounds: SmallVec::new(),
+        supports_unions: true,
+        methods: SmallVec::new(),
+        associated_types: SmallVec::new(),
+        is_const,
+        safety: Safety::Default,
+        document: true,
+    };
+
+    trait_def.expand(cx, mitem, item, push);
+}
diff --git a/compiler/rustc_builtin_macros/src/deriving/mod.rs b/compiler/rustc_builtin_macros/src/deriving/mod.rs
index 337ee43938bd7..404991903c424 100644
--- a/compiler/rustc_builtin_macros/src/deriving/mod.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/mod.rs
@@ -14,9 +14,10 @@ macro path_std($($x:tt)*) {
     generic::ty::Path::new( pathvec!( $($x)* ) )
 }
 
-pub(crate) mod bounds;
 pub(crate) mod clone;
 pub(crate) mod coerce_pointee;
+pub(crate) mod const_param_ty;
+pub(crate) mod copy;
 pub(crate) mod debug;
 pub(crate) mod default;
 pub(crate) mod eq;
diff --git a/compiler/rustc_builtin_macros/src/lib.rs b/compiler/rustc_builtin_macros/src/lib.rs
index db92413e1b162..57759bb113401 100644
--- a/compiler/rustc_builtin_macros/src/lib.rs
+++ b/compiler/rustc_builtin_macros/src/lib.rs
@@ -133,8 +133,8 @@ pub fn register_builtin_macros(resolver: &mut dyn ResolverExpand) {
     register_derive! {
         Clone: clone::expand_deriving_clone,
         CoerceShared: reborrow::expand_deriving_coerce_shared,
-        Copy: bounds::expand_deriving_copy,
-        ConstParamTy: bounds::expand_deriving_const_param_ty,
+        Copy: copy::expand_deriving_copy,
+        ConstParamTy: const_param_ty::expand_deriving_const_param_ty,
         Debug: debug::expand_deriving_debug,
         Default: default::expand_deriving_default,
         Eq: eq::expand_deriving_eq,

From e27ac1e5d9e51fa6acda5030c8fb428d2bbf710b Mon Sep 17 00:00:00 2001
From: cyrgani <ansgar.w.zielke@gmail.com>
Date: Thu, 27 Aug 2026 12:35:28 +0000
Subject: [PATCH 7/8] remove last `StaticFields` usage

---
 .../src/deriving/default.rs                   | 40 +++++++++++--------
 tests/ui/derives/deriving-all-codegen.stdout  |  2 +-
 2 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/compiler/rustc_builtin_macros/src/deriving/default.rs b/compiler/rustc_builtin_macros/src/deriving/default.rs
index 88e9d8daf1bd9..eb9a302be31e0 100644
--- a/compiler/rustc_builtin_macros/src/deriving/default.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/default.rs
@@ -38,8 +38,8 @@ pub(crate) fn expand_deriving_default(
             fieldless_variants_strategy: FieldlessVariantsStrategy::Default,
             combine_substructure: combine_substructure(|cx, trait_span, substr| {
                 match substr.fields {
-                    StaticStruct(_, fields) => {
-                        default_struct_substructure(cx, trait_span, substr, fields)
+                    StaticStruct(variant_data, _) => {
+                        default_struct_substructure(cx, trait_span, substr, variant_data)
                     }
                     StaticEnum(enum_def) => {
                         default_enum_substructure(cx, trait_span, enum_def, item.span)
@@ -66,27 +66,35 @@ fn default_struct_substructure(
     cx: &ExtCtxt<'_>,
     trait_span: Span,
     substr: &Substructure<'_>,
-    summary: &StaticFields<'_>,
+    variant_data: &VariantData,
 ) -> BlockOrExpr {
-    let expr = match summary {
-        Unnamed(_, IsTuple::No) => cx.expr_ident(trait_span, substr.type_ident),
-        Unnamed(fields, IsTuple::Yes) => {
-            let exprs = fields.iter().map(|sp| default_call(cx, *sp)).collect();
+    let expr = match variant_data {
+        VariantData::Unit(_) => cx.expr_ident(trait_span, substr.type_ident),
+        VariantData::Tuple(fields, _) => {
+            let exprs = fields
+                .iter()
+                .map(|field| default_call(cx, field.span.with_ctxt(trait_span.ctxt())))
+                .collect();
             cx.expr_call_ident(trait_span, substr.type_ident, exprs)
         }
-        Named(fields) => {
+        VariantData::Struct { fields, .. } => {
             let default_fields = fields
                 .iter()
-                .map(|&(ident, span, default_val)| {
-                    let value = match default_val {
-                        // We use `Default::default()`.
-                        None => default_call(cx, span),
+                .map(|field| {
+                    let span = field.span.with_ctxt(trait_span.ctxt());
+                    let value = if let Some(extras) = &field.extras
+                        && let Some(default_val) = &extras.default
+                    {
                         // We use the field default const expression.
-                        Some(val) => {
-                            cx.expr(val.value.span, ast::ExprKind::ConstBlock(val.clone()))
-                        }
+                        cx.expr(
+                            default_val.value.span,
+                            ast::ExprKind::ConstBlock(default_val.clone()),
+                        )
+                    } else {
+                        // We use `Default::default()`.
+                        default_call(cx, span)
                     };
-                    cx.field_imm(span, ident, value)
+                    cx.field_imm(span, field.ident.unwrap(), value)
                 })
                 .collect();
             cx.expr_struct_ident(trait_span, substr.type_ident, default_fields)
diff --git a/tests/ui/derives/deriving-all-codegen.stdout b/tests/ui/derives/deriving-all-codegen.stdout
index d0b387dbc8b25..6f7d817db00d7 100644
--- a/tests/ui/derives/deriving-all-codegen.stdout
+++ b/tests/ui/derives/deriving-all-codegen.stdout
@@ -46,7 +46,7 @@ impl ::core::fmt::Debug for Empty {
 #[automatically_derived]
 impl ::core::default::Default for Empty {
     #[inline]
-    fn default() -> Empty { Empty {} }
+    fn default() -> Empty { Empty }
 }
 #[automatically_derived]
 impl ::core::hash::Hash for Empty {

From 4178dac3a87806d7887fa7363547773314a9b412 Mon Sep 17 00:00:00 2001
From: cyrgani <ansgar.w.zielke@gmail.com>
Date: Thu, 27 Aug 2026 12:39:06 +0000
Subject: [PATCH 8/8] remove `StaticFields` and `IsTuple`

---
 .../src/deriving/default.rs                   |  2 +-
 .../rustc_builtin_macros/src/deriving/from.rs |  2 +-
 .../src/deriving/generic/mod.rs               | 72 ++-----------------
 3 files changed, 7 insertions(+), 69 deletions(-)

diff --git a/compiler/rustc_builtin_macros/src/deriving/default.rs b/compiler/rustc_builtin_macros/src/deriving/default.rs
index eb9a302be31e0..9e65ae0b75cab 100644
--- a/compiler/rustc_builtin_macros/src/deriving/default.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/default.rs
@@ -38,7 +38,7 @@ pub(crate) fn expand_deriving_default(
             fieldless_variants_strategy: FieldlessVariantsStrategy::Default,
             combine_substructure: combine_substructure(|cx, trait_span, substr| {
                 match substr.fields {
-                    StaticStruct(variant_data, _) => {
+                    StaticStruct(variant_data) => {
                         default_struct_substructure(cx, trait_span, substr, variant_data)
                     }
                     StaticEnum(enum_def) => {
diff --git a/compiler/rustc_builtin_macros/src/deriving/from.rs b/compiler/rustc_builtin_macros/src/deriving/from.rs
index 0758ff0269a96..eb8ddd10d4306 100644
--- a/compiler/rustc_builtin_macros/src/deriving/from.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/from.rs
@@ -91,7 +91,7 @@ pub(crate) fn expand_deriving_from(
 
                 let self_kw = Ident::new(kw::SelfUpper, span);
                 let expr: Box<ast::Expr> = match substructure.fields {
-                    SubstructureFields::StaticStruct(variant, _) => match variant {
+                    SubstructureFields::StaticStruct(variant) => match variant {
                         // Self { field: value }
                         VariantData::Struct { .. } => cx.expr_struct_ident(
                             span,
diff --git a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
index 436881dbf2209..3298b4a583ff8 100644
--- a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
@@ -177,14 +177,13 @@
 use std::ops::Not;
 use std::{iter, vec};
 
-pub(crate) use StaticFields::*;
 pub(crate) use SubstructureFields::*;
 pub(crate) use rustc_ast as ast;
 use rustc_ast::token::{IdentIsRaw, LitKind, Token, TokenKind};
 use rustc_ast::tokenstream::{DelimSpan, Spacing, TokenTree};
 use rustc_ast::{
-    AnonConst, AttrArgs, BindingMode, ByRef, DelimArgs, EnumDef, Expr, GenericArg,
-    GenericParamKind, Generics, Mutability, PatKind, Safety, SelfKind, VariantData,
+    AttrArgs, BindingMode, ByRef, DelimArgs, EnumDef, Expr, GenericArg, GenericParamKind, Generics,
+    Mutability, PatKind, Safety, SelfKind, VariantData,
 };
 use rustc_attr_ir::{Attribute, AttributeKind, ReprPacked};
 use rustc_attr_parsing::AttributeParser;
@@ -294,20 +293,6 @@ pub(crate) struct FieldInfo {
     pub maybe_scalar: bool,
 }
 
-#[derive(Copy, Clone)]
-pub(crate) enum IsTuple {
-    No,
-    Yes,
-}
-
-/// Fields for a static method
-pub(crate) enum StaticFields<'a> {
-    /// Tuple and unit structs/enum variants like this.
-    Unnamed(Vec<Span>, IsTuple),
-    /// Normal structs/struct variants.
-    Named(Vec<(Ident, Span, Option<&'a AnonConst>)>),
-}
-
 /// A summary of the possible sets of fields.
 pub(crate) enum SubstructureFields<'a> {
     /// A non-static method where `Self` is a struct.
@@ -329,7 +314,7 @@ pub(crate) enum SubstructureFields<'a> {
     EnumDiscr(FieldInfo, Option<Box<Expr>>),
 
     /// A static method where `Self` is a struct.
-    StaticStruct(&'a ast::VariantData, StaticFields<'a>),
+    StaticStruct(&'a ast::VariantData),
 
     /// A static method where `Self` is an enum.
     StaticEnum(&'a ast::EnumDef),
@@ -860,12 +845,12 @@ impl<'a> TraitDef<'a> {
                     method_def.extract_arg_details(cx, self, type_ident, generics);
 
                 let body = if from_scratch || method_def.is_static() {
-                    method_def.expand_static_struct_method_body(
+                    method_def.call_substructure_method(
                         cx,
                         self,
-                        struct_def,
                         type_ident,
                         &nonselflike_args,
+                        &StaticStruct(struct_def),
                     )
                 } else {
                     method_def.expand_struct_method_body(
@@ -1133,25 +1118,6 @@ impl<'a> MethodDef<'a> {
         )
     }
 
-    fn expand_static_struct_method_body(
-        &self,
-        cx: &ExtCtxt<'_>,
-        trait_: &TraitDef<'a>,
-        struct_def: &'a VariantData,
-        type_ident: Ident,
-        nonselflike_args: &[Box<Expr>],
-    ) -> BlockOrExpr {
-        let summary = trait_.summarise_struct(cx, struct_def);
-
-        self.call_substructure_method(
-            cx,
-            trait_,
-            type_ident,
-            nonselflike_args,
-            &StaticStruct(struct_def, summary),
-        )
-    }
-
     /// ```
     /// #[derive(PartialEq)]
     /// # struct Dummy;
@@ -1450,34 +1416,6 @@ impl<'a> MethodDef<'a> {
 
 // general helper methods.
 impl<'a> TraitDef<'a> {
-    fn summarise_struct(&self, cx: &ExtCtxt<'_>, struct_def: &'a VariantData) -> StaticFields<'a> {
-        let mut named_idents = Vec::new();
-        let mut just_spans = Vec::new();
-        for field in struct_def.fields() {
-            let sp = field.span.with_ctxt(self.span.ctxt());
-            match field.ident {
-                Some(ident) => named_idents.push((ident, sp, field.default_value())),
-                _ => just_spans.push(sp),
-            }
-        }
-
-        let is_tuple = match struct_def {
-            ast::VariantData::Tuple(..) => IsTuple::Yes,
-            _ => IsTuple::No,
-        };
-        match (just_spans.is_empty(), named_idents.is_empty()) {
-            (false, false) => cx
-                .dcx()
-                .span_bug(self.span, "a struct with named and unnamed fields in generic `derive`"),
-            // named fields
-            (_, false) => Named(named_idents),
-            // unnamed fields
-            (false, _) => Unnamed(just_spans, is_tuple),
-            // empty
-            _ => Named(Vec::new()),
-        }
-    }
-
     fn create_struct_patterns(
         &self,
         cx: &ExtCtxt<'_>,