Auto merge of #142455 - jdonszelmann:attempt-to-mitigate-delayed-lint-perf-problems, r=oli-obk

collect delayed lints in hir_crate_items

r? `@oli-obk`

Attempt to mitigate perf problems in #138164

Author: bors

compiler/rustc_ast_lowering/src/item.rs

@@ -145,6 +145,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             kind,
             vis_span,
             span: self.lower_span(i.span),
+            has_delayed_lints: !self.delayed_lints.is_empty(),
         };
         self.arena.alloc(item)
     }
@@ -599,6 +600,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                             kind,
                             vis_span,
                             span: this.lower_span(use_tree.span),
+                            has_delayed_lints: !this.delayed_lints.is_empty(),
                         };
                         hir::OwnerNode::Item(this.arena.alloc(item))
                     });
@@ -697,6 +699,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             kind,
             vis_span: self.lower_span(i.vis.span),
             span: self.lower_span(i.span),
+            has_delayed_lints: !self.delayed_lints.is_empty(),
         };
         self.arena.alloc(item)
     }
@@ -941,6 +944,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             kind,
             span: self.lower_span(i.span),
             defaultness: hir::Defaultness::Default { has_value: has_default },
+            has_delayed_lints: !self.delayed_lints.is_empty(),
         };
         self.arena.alloc(item)
     }
@@ -1100,6 +1104,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             vis_span: self.lower_span(i.vis.span),
             span: self.lower_span(i.span),
             defaultness,
+            has_delayed_lints: !self.delayed_lints.is_empty(),
         };
         self.arena.alloc(item)
     }

compiler/rustc_hir/src/hir.rs

@@ -3064,6 +3064,7 @@ pub struct TraitItem<'hir> {
     pub kind: TraitItemKind<'hir>,
     pub span: Span,
     pub defaultness: Defaultness,
+    pub has_delayed_lints: bool,
 }
 
 macro_rules! expect_methods_self_kind {
@@ -3168,6 +3169,7 @@ pub struct ImplItem<'hir> {
     pub defaultness: Defaultness,
     pub span: Span,
     pub vis_span: Span,
+    pub has_delayed_lints: bool,
 }
 
 impl<'hir> ImplItem<'hir> {
@@ -4087,6 +4089,7 @@ pub struct Item<'hir> {
     pub kind: ItemKind<'hir>,
     pub span: Span,
     pub vis_span: Span,
+    pub has_delayed_lints: bool,
 }
 
 impl<'hir> Item<'hir> {
@@ -4492,6 +4495,7 @@ pub struct ForeignItem<'hir> {
     pub owner_id: OwnerId,
     pub span: Span,
     pub vis_span: Span,
+    pub has_delayed_lints: bool,
 }
 
 impl ForeignItem<'_> {
@@ -4974,7 +4978,7 @@ mod size_asserts {
     static_assert_size!(Expr<'_>, 64);
     static_assert_size!(ExprKind<'_>, 48);
     static_assert_size!(FnDecl<'_>, 40);
-    static_assert_size!(ForeignItem<'_>, 88);
+    static_assert_size!(ForeignItem<'_>, 96);
     static_assert_size!(ForeignItemKind<'_>, 56);
     static_assert_size!(GenericArg<'_>, 16);
     static_assert_size!(GenericBound<'_>, 64);

compiler/rustc_hir/src/intravisit.rs

@@ -537,7 +537,7 @@ pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param<'v>) ->
 }
 
 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) -> V::Result {
-    let Item { owner_id: _, kind, span: _, vis_span: _ } = item;
+    let Item { owner_id: _, kind, span: _, vis_span: _, has_delayed_lints: _ } = item;
     try_visit!(visitor.visit_id(item.hir_id()));
     match *kind {
         ItemKind::ExternCrate(orig_name, ident) => {
@@ -656,7 +656,8 @@ pub fn walk_foreign_item<'v, V: Visitor<'v>>(
     visitor: &mut V,
     foreign_item: &'v ForeignItem<'v>,
 ) -> V::Result {
-    let ForeignItem { ident, kind, owner_id: _, span: _, vis_span: _ } = foreign_item;
+    let ForeignItem { ident, kind, owner_id: _, span: _, vis_span: _, has_delayed_lints: _ } =
+        foreign_item;
     try_visit!(visitor.visit_id(foreign_item.hir_id()));
     try_visit!(visitor.visit_ident(*ident));
 
@@ -1205,7 +1206,15 @@ pub fn walk_trait_item<'v, V: Visitor<'v>>(
     visitor: &mut V,
     trait_item: &'v TraitItem<'v>,
 ) -> V::Result {
-    let TraitItem { ident, generics, ref defaultness, ref kind, span, owner_id: _ } = *trait_item;
+    let TraitItem {
+        ident,
+        generics,
+        ref defaultness,
+        ref kind,
+        span,
+        owner_id: _,
+        has_delayed_lints: _,
+    } = *trait_item;
     let hir_id = trait_item.hir_id();
     try_visit!(visitor.visit_ident(ident));
     try_visit!(visitor.visit_generics(&generics));
@@ -1261,6 +1270,7 @@ pub fn walk_impl_item<'v, V: Visitor<'v>>(
         ref defaultness,
         span: _,
         vis_span: _,
+        has_delayed_lints: _,
     } = *impl_item;
 
     try_visit!(visitor.visit_ident(ident));

compiler/rustc_hir_analysis/src/lib.rs

@@ -193,13 +193,41 @@ pub fn check_crate(tcx: TyCtxt<'_>) {
         let _: R = tcx.ensure_ok().crate_inherent_impls_overlap_check(());
     });
 
-    for owner_id in tcx.hir_crate_items(()).owners() {
-        if let Some(delayed_lints) = tcx.opt_ast_lowering_delayed_lints(owner_id) {
-            for lint in &delayed_lints.lints {
-                emit_delayed_lint(lint, tcx);
+    tcx.sess.time("emit_ast_lowering_delayed_lints", || {
+        // sanity check in debug mode that all lints are really noticed
+        // and we really will emit them all in the loop right below.
+        //
+        // during ast lowering, when creating items, foreign items, trait items and impl items
+        // we store in them whether they have any lints in their owner node that should be
+        // picked up by `hir_crate_items`. However, theoretically code can run between that
+        // boolean being inserted into the item and the owner node being created.
+        // We don't want any new lints to be emitted there
+        // (though honestly, you have to really try to manage to do that but still),
+        // but this check is there to catch that.
+        #[cfg(debug_assertions)]
+        {
+            // iterate over all owners
+            for owner_id in tcx.hir_crate_items(()).owners() {
+                // if it has delayed lints
+                if let Some(delayed_lints) = tcx.opt_ast_lowering_delayed_lints(owner_id) {
+                    if !delayed_lints.lints.is_empty() {
+                        // assert that delayed_lint_items also picked up this item to have lints
+                        assert!(
+                            tcx.hir_crate_items(()).delayed_lint_items().any(|i| i == owner_id)
+                        );
+                    }
+                }
             }
         }
-    }
+
+        for owner_id in tcx.hir_crate_items(()).delayed_lint_items() {
+            if let Some(delayed_lints) = tcx.opt_ast_lowering_delayed_lints(owner_id) {
+                for lint in &delayed_lints.lints {
+                    emit_delayed_lint(lint, tcx);
+                }
+            }
+        }
+    });
 
     tcx.par_hir_body_owners(|item_def_id| {
         let def_kind = tcx.def_kind(item_def_id);

compiler/rustc_middle/src/hir/map.rs

@@ -1233,6 +1233,7 @@ pub(super) fn hir_module_items(tcx: TyCtxt<'_>, module_id: LocalModDefId) -> Mod
         body_owners: body_owners.into_boxed_slice(),
         opaques: opaques.into_boxed_slice(),
         nested_bodies: nested_bodies.into_boxed_slice(),
+        delayed_lint_items: Box::new([]),
     }
 }
 
@@ -1254,6 +1255,7 @@ pub(crate) fn hir_crate_items(tcx: TyCtxt<'_>, _: ()) -> ModuleItems {
         body_owners,
         opaques,
         nested_bodies,
+        delayed_lint_items,
         ..
     } = collector;
 
@@ -1266,6 +1268,7 @@ pub(crate) fn hir_crate_items(tcx: TyCtxt<'_>, _: ()) -> ModuleItems {
         body_owners: body_owners.into_boxed_slice(),
         opaques: opaques.into_boxed_slice(),
         nested_bodies: nested_bodies.into_boxed_slice(),
+        delayed_lint_items: delayed_lint_items.into_boxed_slice(),
     }
 }
 
@@ -1282,6 +1285,7 @@ struct ItemCollector<'tcx> {
     body_owners: Vec<LocalDefId>,
     opaques: Vec<LocalDefId>,
     nested_bodies: Vec<LocalDefId>,
+    delayed_lint_items: Vec<OwnerId>,
 }
 
 impl<'tcx> ItemCollector<'tcx> {
@@ -1297,6 +1301,7 @@ impl<'tcx> ItemCollector<'tcx> {
             body_owners: Vec::default(),
             opaques: Vec::default(),
             nested_bodies: Vec::default(),
+            delayed_lint_items: Vec::default(),
         }
     }
 }
@@ -1314,6 +1319,9 @@ impl<'hir> Visitor<'hir> for ItemCollector<'hir> {
         }
 
         self.items.push(item.item_id());
+        if self.crate_collector && item.has_delayed_lints {
+            self.delayed_lint_items.push(item.item_id().owner_id);
+        }
 
         // Items that are modules are handled here instead of in visit_mod.
         if let ItemKind::Mod(_, module) = &item.kind {
@@ -1329,6 +1337,9 @@ impl<'hir> Visitor<'hir> for ItemCollector<'hir> {
 
     fn visit_foreign_item(&mut self, item: &'hir ForeignItem<'hir>) {
         self.foreign_items.push(item.foreign_item_id());
+        if self.crate_collector && item.has_delayed_lints {
+            self.delayed_lint_items.push(item.foreign_item_id().owner_id);
+        }
         intravisit::walk_foreign_item(self, item)
     }
 
@@ -1362,6 +1373,10 @@ impl<'hir> Visitor<'hir> for ItemCollector<'hir> {
         }
 
         self.trait_items.push(item.trait_item_id());
+        if self.crate_collector && item.has_delayed_lints {
+            self.delayed_lint_items.push(item.trait_item_id().owner_id);
+        }
+
         intravisit::walk_trait_item(self, item)
     }
 
@@ -1371,6 +1386,10 @@ impl<'hir> Visitor<'hir> for ItemCollector<'hir> {
         }
 
         self.impl_items.push(item.impl_item_id());
+        if self.crate_collector && item.has_delayed_lints {
+            self.delayed_lint_items.push(item.impl_item_id().owner_id);
+        }
+
         intravisit::walk_impl_item(self, item)
     }
 }

compiler/rustc_middle/src/hir/mod.rs

@@ -32,6 +32,8 @@ pub struct ModuleItems {
     opaques: Box<[LocalDefId]>,
     body_owners: Box<[LocalDefId]>,
     nested_bodies: Box<[LocalDefId]>,
+    // only filled with hir_crate_items, not with hir_module_items
+    delayed_lint_items: Box<[OwnerId]>,
 }
 
 impl ModuleItems {
@@ -49,6 +51,10 @@ impl ModuleItems {
         self.trait_items.iter().copied()
     }
 
+    pub fn delayed_lint_items(&self) -> impl Iterator<Item = OwnerId> {
+        self.delayed_lint_items.iter().copied()
+    }
+
     /// Returns all items that are associated with some `impl` block (both inherent and trait impl
     /// blocks).
     pub fn impl_items(&self) -> impl Iterator<Item = ImplItemId> {