Auto merge of #129789 - notriddle:notriddle/inline-stmt-local, r=GuillaumeGomez

rustdoc: use strategic boxing to shrink `clean::Item`

* `inline_stmt_id` is never a cross-crate DefId, so save space by not storing it.
* Instead of two inner boxes for `Item`, use one.

Author: bors

src/librustdoc/clean/auto_trait.rs

@@ -115,17 +115,19 @@ fn synthesize_auto_trait_impl<'tcx>(
 
     Some(clean::Item {
         name: None,
-        attrs: Default::default(),
+        inner: Box::new(clean::ItemInner {
+            attrs: Default::default(),
+            kind: clean::ImplItem(Box::new(clean::Impl {
+                safety: hir::Safety::Safe,
+                generics,
+                trait_: Some(clean_trait_ref_with_constraints(cx, trait_ref, ThinVec::new())),
+                for_: clean_middle_ty(ty::Binder::dummy(ty), cx, None, None),
+                items: Vec::new(),
+                polarity,
+                kind: clean::ImplKind::Auto,
+            })),
+        }),
         item_id: clean::ItemId::Auto { trait_: trait_def_id, for_: item_def_id },
-        kind: Box::new(clean::ImplItem(Box::new(clean::Impl {
-            safety: hir::Safety::Safe,
-            generics,
-            trait_: Some(clean_trait_ref_with_constraints(cx, trait_ref, ThinVec::new())),
-            for_: clean_middle_ty(ty::Binder::dummy(ty), cx, None, None),
-            items: Vec::new(),
-            polarity,
-            kind: clean::ImplKind::Auto,
-        }))),
         cfg: None,
         inline_stmt_id: None,
     })

src/librustdoc/clean/blanket_impl.rs

@@ -84,42 +84,44 @@ pub(crate) fn synthesize_blanket_impls(
 
             blanket_impls.push(clean::Item {
                 name: None,
-                attrs: Default::default(),
                 item_id: clean::ItemId::Blanket { impl_id: impl_def_id, for_: item_def_id },
-                kind: Box::new(clean::ImplItem(Box::new(clean::Impl {
-                    safety: hir::Safety::Safe,
-                    generics: clean_ty_generics(
-                        cx,
-                        tcx.generics_of(impl_def_id),
-                        tcx.explicit_predicates_of(impl_def_id),
-                    ),
-                    // FIXME(eddyb) compute both `trait_` and `for_` from
-                    // the post-inference `trait_ref`, as it's more accurate.
-                    trait_: Some(clean_trait_ref_with_constraints(
-                        cx,
-                        ty::Binder::dummy(trait_ref.instantiate_identity()),
-                        ThinVec::new(),
-                    )),
-                    for_: clean_middle_ty(
-                        ty::Binder::dummy(ty.instantiate_identity()),
-                        cx,
-                        None,
-                        None,
-                    ),
-                    items: tcx
-                        .associated_items(impl_def_id)
-                        .in_definition_order()
-                        .filter(|item| !item.is_impl_trait_in_trait())
-                        .map(|item| clean_middle_assoc_item(item, cx))
-                        .collect(),
-                    polarity: ty::ImplPolarity::Positive,
-                    kind: clean::ImplKind::Blanket(Box::new(clean_middle_ty(
-                        ty::Binder::dummy(trait_ref.instantiate_identity().self_ty()),
-                        cx,
-                        None,
-                        None,
-                    ))),
-                }))),
+                inner: Box::new(clean::ItemInner {
+                    attrs: Default::default(),
+                    kind: clean::ImplItem(Box::new(clean::Impl {
+                        safety: hir::Safety::Safe,
+                        generics: clean_ty_generics(
+                            cx,
+                            tcx.generics_of(impl_def_id),
+                            tcx.explicit_predicates_of(impl_def_id),
+                        ),
+                        // FIXME(eddyb) compute both `trait_` and `for_` from
+                        // the post-inference `trait_ref`, as it's more accurate.
+                        trait_: Some(clean_trait_ref_with_constraints(
+                            cx,
+                            ty::Binder::dummy(trait_ref.instantiate_identity()),
+                            ThinVec::new(),
+                        )),
+                        for_: clean_middle_ty(
+                            ty::Binder::dummy(ty.instantiate_identity()),
+                            cx,
+                            None,
+                            None,
+                        ),
+                        items: tcx
+                            .associated_items(impl_def_id)
+                            .in_definition_order()
+                            .filter(|item| !item.is_impl_trait_in_trait())
+                            .map(|item| clean_middle_assoc_item(item, cx))
+                            .collect(),
+                        polarity: ty::ImplPolarity::Positive,
+                        kind: clean::ImplKind::Blanket(Box::new(clean_middle_ty(
+                            ty::Binder::dummy(trait_ref.instantiate_identity().self_ty()),
+                            cx,
+                            None,
+                            None,
+                        ))),
+                    })),
+                }),
                 cfg: None,
                 inline_stmt_id: None,
             });

src/librustdoc/clean/inline.rs

@@ -5,7 +5,7 @@ use std::sync::Arc;
 
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::def_id::{DefId, DefIdSet, LocalModDefId};
+use rustc_hir::def_id::{DefId, DefIdSet, LocalDefId, LocalModDefId};
 use rustc_hir::Mutability;
 use rustc_metadata::creader::{CStore, LoadedMacro};
 use rustc_middle::ty::fast_reject::SimplifiedType;
@@ -43,7 +43,7 @@ pub(crate) fn try_inline(
     cx: &mut DocContext<'_>,
     res: Res,
     name: Symbol,
-    attrs: Option<(&[ast::Attribute], Option<DefId>)>,
+    attrs: Option<(&[ast::Attribute], Option<LocalDefId>)>,
     visited: &mut DefIdSet,
 ) -> Option<Vec<clean::Item>> {
     let did = res.opt_def_id()?;
@@ -152,14 +152,8 @@ pub(crate) fn try_inline(
     };
 
     cx.inlined.insert(did.into());
-    let mut item = crate::clean::generate_item_with_correct_attrs(
-        cx,
-        kind,
-        did,
-        name,
-        import_def_id.and_then(|def_id| def_id.as_local()),
-        None,
-    );
+    let mut item =
+        crate::clean::generate_item_with_correct_attrs(cx, kind, did, name, import_def_id, None);
     // The visibility needs to reflect the one from the reexport and not from the "source" DefId.
     item.inline_stmt_id = import_def_id;
     ret.push(item);
@@ -198,7 +192,7 @@ pub(crate) fn try_inline_glob(
                 visited,
                 inlined_names,
                 Some(&reexports),
-                Some((attrs, Some(import.owner_id.def_id.to_def_id()))),
+                Some((attrs, Some(import.owner_id.def_id))),
             );
             items.retain(|item| {
                 if let Some(name) = item.name {
@@ -372,7 +366,7 @@ fn build_type_alias(
 pub(crate) fn build_impls(
     cx: &mut DocContext<'_>,
     did: DefId,
-    attrs: Option<(&[ast::Attribute], Option<DefId>)>,
+    attrs: Option<(&[ast::Attribute], Option<LocalDefId>)>,
     ret: &mut Vec<clean::Item>,
 ) {
     let _prof_timer = cx.tcx.sess.prof.generic_activity("build_inherent_impls");
@@ -405,7 +399,7 @@ pub(crate) fn build_impls(
 pub(crate) fn merge_attrs(
     cx: &mut DocContext<'_>,
     old_attrs: &[ast::Attribute],
-    new_attrs: Option<(&[ast::Attribute], Option<DefId>)>,
+    new_attrs: Option<(&[ast::Attribute], Option<LocalDefId>)>,
 ) -> (clean::Attributes, Option<Arc<clean::cfg::Cfg>>) {
     // NOTE: If we have additional attributes (from a re-export),
     // always insert them first. This ensure that re-export
@@ -416,7 +410,7 @@ pub(crate) fn merge_attrs(
         both.extend_from_slice(old_attrs);
         (
             if let Some(item_id) = item_id {
-                Attributes::from_ast_with_additional(old_attrs, (inner, item_id))
+                Attributes::from_ast_with_additional(old_attrs, (inner, item_id.to_def_id()))
             } else {
                 Attributes::from_ast(&both)
             },
@@ -431,7 +425,7 @@ pub(crate) fn merge_attrs(
 pub(crate) fn build_impl(
     cx: &mut DocContext<'_>,
     did: DefId,
-    attrs: Option<(&[ast::Attribute], Option<DefId>)>,
+    attrs: Option<(&[ast::Attribute], Option<LocalDefId>)>,
     ret: &mut Vec<clean::Item>,
 ) {
     if !cx.inlined.insert(did.into()) {
@@ -623,7 +617,7 @@ pub(crate) fn build_impl(
                 ImplKind::Normal
             },
         })),
-        Box::new(merged_attrs),
+        merged_attrs,
         cfg,
     ));
 }
@@ -641,7 +635,7 @@ fn build_module_items(
     visited: &mut DefIdSet,
     inlined_names: &mut FxHashSet<(ItemType, Symbol)>,
     allowed_def_ids: Option<&DefIdSet>,
-    attrs: Option<(&[ast::Attribute], Option<DefId>)>,
+    attrs: Option<(&[ast::Attribute], Option<LocalDefId>)>,
 ) -> Vec<clean::Item> {
     let mut items = Vec::new();
 
@@ -673,27 +667,29 @@ fn build_module_items(
                 let prim_ty = clean::PrimitiveType::from(p);
                 items.push(clean::Item {
                     name: None,
-                    attrs: Box::default(),
                     // We can use the item's `DefId` directly since the only information ever used
                     // from it is `DefId.krate`.
                     item_id: ItemId::DefId(did),
-                    kind: Box::new(clean::ImportItem(clean::Import::new_simple(
-                        item.ident.name,
-                        clean::ImportSource {
-                            path: clean::Path {
-                                res,
-                                segments: thin_vec![clean::PathSegment {
-                                    name: prim_ty.as_sym(),
-                                    args: clean::GenericArgs::AngleBracketed {
-                                        args: Default::default(),
-                                        constraints: ThinVec::new(),
-                                    },
-                                }],
+                    inner: Box::new(clean::ItemInner {
+                        attrs: Default::default(),
+                        kind: clean::ImportItem(clean::Import::new_simple(
+                            item.ident.name,
+                            clean::ImportSource {
+                                path: clean::Path {
+                                    res,
+                                    segments: thin_vec![clean::PathSegment {
+                                        name: prim_ty.as_sym(),
+                                        args: clean::GenericArgs::AngleBracketed {
+                                            args: Default::default(),
+                                            constraints: ThinVec::new(),
+                                        },
+                                    }],
+                                },
+                                did: None,
                             },
-                            did: None,
-                        },
-                        true,
-                    ))),
+                            true,
+                        )),
+                    }),
                     cfg: None,
                     inline_stmt_id: None,
                 });
@@ -745,15 +741,16 @@ fn build_macro(
     cx: &mut DocContext<'_>,
     def_id: DefId,
     name: Symbol,
-    import_def_id: Option<DefId>,
+    import_def_id: Option<LocalDefId>,
     macro_kind: MacroKind,
     is_doc_hidden: bool,
 ) -> clean::ItemKind {
     match CStore::from_tcx(cx.tcx).load_macro_untracked(def_id, cx.tcx) {
         LoadedMacro::MacroDef(item_def, _) => match macro_kind {
             MacroKind::Bang => {
                 if let ast::ItemKind::MacroDef(ref def) = item_def.kind {
-                    let vis = cx.tcx.visibility(import_def_id.unwrap_or(def_id));
+                    let vis =
+                        cx.tcx.visibility(import_def_id.map(|d| d.to_def_id()).unwrap_or(def_id));
                     clean::MacroItem(clean::Macro {
                         source: utils::display_macro_source(
                             cx,

src/librustdoc/clean/mod.rs

@@ -203,8 +203,8 @@ fn generate_item_with_correct_attrs(
     let attrs = Attributes::from_ast_iter(attrs.iter().map(|(attr, did)| (&**attr, *did)), false);
 
     let name = renamed.or(Some(name));
-    let mut item = Item::from_def_id_and_attrs_and_parts(def_id, name, kind, Box::new(attrs), cfg);
-    item.inline_stmt_id = import_id.map(|local| local.to_def_id());
+    let mut item = Item::from_def_id_and_attrs_and_parts(def_id, name, kind, attrs, cfg);
+    item.inline_stmt_id = import_id;
     item
 }
 
@@ -2927,7 +2927,7 @@ fn clean_extern_crate<'tcx>(
         })
         && !cx.output_format.is_json();
 
-    let krate_owner_def_id = krate.owner_id.to_def_id();
+    let krate_owner_def_id = krate.owner_id.def_id;
     if please_inline {
         if let Some(items) = inline::try_inline(
             cx,
@@ -2941,7 +2941,7 @@ fn clean_extern_crate<'tcx>(
     }
 
     vec![Item::from_def_id_and_parts(
-        krate_owner_def_id,
+        krate_owner_def_id.to_def_id(),
         Some(name),
         ExternCrateItem { src: orig_name },
         cx,
@@ -2988,7 +2988,7 @@ fn clean_use_statement_inner<'tcx>(
     let inline_attr = attrs.lists(sym::doc).get_word_attr(sym::inline);
     let pub_underscore = visibility.is_public() && name == kw::Underscore;
     let current_mod = cx.tcx.parent_module_from_def_id(import.owner_id.def_id);
-    let import_def_id = import.owner_id.def_id.to_def_id();
+    let import_def_id = import.owner_id.def_id;
 
     // The parent of the module in which this import resides. This
     // is the same as `current_mod` if that's already the top
@@ -3071,7 +3071,7 @@ fn clean_use_statement_inner<'tcx>(
             )
         {
             items.push(Item::from_def_id_and_parts(
-                import_def_id,
+                import_def_id.to_def_id(),
                 None,
                 ImportItem(Import::new_simple(name, resolve_use_source(cx, path), false)),
                 cx,
@@ -3081,7 +3081,7 @@ fn clean_use_statement_inner<'tcx>(
         Import::new_simple(name, resolve_use_source(cx, path), true)
     };
 
-    vec![Item::from_def_id_and_parts(import_def_id, None, ImportItem(inner), cx)]
+    vec![Item::from_def_id_and_parts(import_def_id.to_def_id(), None, ImportItem(inner), cx)]
 }
 
 fn clean_maybe_renamed_foreign_item<'tcx>(