Auto merge of rust-lang#120919 - oli-obk:impl_polarity, r=compiler-errors

Merge `impl_polarity` and `impl_trait_ref` queries

Hopefully this is perf neutral. I want to finish rust-lang#120835 and stop using the HIR in `coherent_trait`, which should then give us a perf improvement.

Author: bors

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -1673,9 +1673,9 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                         .is_accessible_from(self.item_def_id(), tcx)
                     && tcx.all_impls(*trait_def_id)
                         .any(|impl_def_id| {
-                            let trait_ref = tcx.impl_trait_ref(impl_def_id);
-                            trait_ref.is_some_and(|trait_ref| {
-                                let impl_ = trait_ref.instantiate(
+                            let impl_header = tcx.impl_trait_header(impl_def_id);
+                            impl_header.is_some_and(|header| {
+                                let header = header.instantiate(
                                     tcx,
                                     infcx.fresh_args_for_item(DUMMY_SP, impl_def_id),
                                 );
@@ -1687,11 +1687,10 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                                 infcx
                                     .can_eq(
                                         ty::ParamEnv::empty(),
-                                        impl_.self_ty(),
+                                        header.trait_ref.self_ty(),
                                         value,
-                                    )
+                                    ) && header.polarity != ty::ImplPolarity::Negative
                             })
-                            && tcx.impl_polarity(impl_def_id) != ty::ImplPolarity::Negative
                         })
             })
             .map(|trait_def_id| tcx.def_path_str(trait_def_id))
@@ -1737,13 +1736,13 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             } else {
                 // Find all the types that have an `impl` for the trait.
                 tcx.all_impls(trait_def_id)
-                    .filter(|impl_def_id| {
+                    .filter_map(|impl_def_id| tcx.impl_trait_header(impl_def_id))
+                    .filter(|header| {
                         // Consider only accessible traits
                         tcx.visibility(trait_def_id).is_accessible_from(self.item_def_id(), tcx)
-                            && tcx.impl_polarity(impl_def_id) != ty::ImplPolarity::Negative
+                            && header.skip_binder().polarity != ty::ImplPolarity::Negative
                     })
-                    .filter_map(|impl_def_id| tcx.impl_trait_ref(impl_def_id))
-                    .map(|impl_| impl_.instantiate_identity().self_ty())
+                    .map(|header| header.instantiate_identity().trait_ref.self_ty())
                     // We don't care about blanket impls.
                     .filter(|self_ty| !self_ty.has_non_region_param())
                     .map(|self_ty| tcx.erase_regions(self_ty).to_string())

compiler/rustc_hir_analysis/src/check/check.rs

@@ -527,8 +527,12 @@ pub(crate) fn check_item_type(tcx: TyCtxt<'_>, def_id: LocalDefId) {
         }
         DefKind::Fn => {} // entirely within check_item_body
         DefKind::Impl { of_trait } => {
-            if of_trait && let Some(impl_trait_ref) = tcx.impl_trait_ref(def_id) {
-                check_impl_items_against_trait(tcx, def_id, impl_trait_ref.instantiate_identity());
+            if of_trait && let Some(impl_trait_header) = tcx.impl_trait_header(def_id) {
+                check_impl_items_against_trait(
+                    tcx,
+                    def_id,
+                    impl_trait_header.instantiate_identity(),
+                );
                 check_on_unimplemented(tcx, def_id);
             }
         }
@@ -719,19 +723,19 @@ pub(super) fn check_specialization_validity<'tcx>(
 fn check_impl_items_against_trait<'tcx>(
     tcx: TyCtxt<'tcx>,
     impl_id: LocalDefId,
-    impl_trait_ref: ty::TraitRef<'tcx>,
+    impl_trait_header: ty::ImplTraitHeader<'tcx>,
 ) {
     // If the trait reference itself is erroneous (so the compilation is going
     // to fail), skip checking the items here -- the `impl_item` table in `tcx`
     // isn't populated for such impls.
-    if impl_trait_ref.references_error() {
+    if impl_trait_header.references_error() {
         return;
     }
 
     let impl_item_refs = tcx.associated_item_def_ids(impl_id);
 
     // Negative impls are not expected to have any items
-    match tcx.impl_polarity(impl_id) {
+    match impl_trait_header.polarity {
         ty::ImplPolarity::Reservation | ty::ImplPolarity::Positive => {}
         ty::ImplPolarity::Negative => {
             if let [first_item_ref, ..] = impl_item_refs {
@@ -748,7 +752,7 @@ fn check_impl_items_against_trait<'tcx>(
         }
     }
 
-    let trait_def = tcx.trait_def(impl_trait_ref.def_id);
+    let trait_def = tcx.trait_def(impl_trait_header.trait_ref.def_id);
 
     for &impl_item in impl_item_refs {
         let ty_impl_item = tcx.associated_item(impl_item);
@@ -767,10 +771,10 @@ fn check_impl_items_against_trait<'tcx>(
                 ));
             }
             ty::AssocKind::Fn => {
-                compare_impl_method(tcx, ty_impl_item, ty_trait_item, impl_trait_ref);
+                compare_impl_method(tcx, ty_impl_item, ty_trait_item, impl_trait_header.trait_ref);
             }
             ty::AssocKind::Type => {
-                compare_impl_ty(tcx, ty_impl_item, ty_trait_item, impl_trait_ref);
+                compare_impl_ty(tcx, ty_impl_item, ty_trait_item, impl_trait_header.trait_ref);
             }
         }
 
@@ -790,7 +794,7 @@ fn check_impl_items_against_trait<'tcx>(
         let mut must_implement_one_of: Option<&[Ident]> =
             trait_def.must_implement_one_of.as_deref();
 
-        for &trait_item_id in tcx.associated_item_def_ids(impl_trait_ref.def_id) {
+        for &trait_item_id in tcx.associated_item_def_ids(impl_trait_header.trait_ref.def_id) {
             let leaf_def = ancestors.leaf_def(tcx, trait_item_id);
 
             let is_implemented = leaf_def
@@ -868,7 +872,7 @@ fn check_impl_items_against_trait<'tcx>(
 
         if let Some(missing_items) = must_implement_one_of {
             let attr_span = tcx
-                .get_attr(impl_trait_ref.def_id, sym::rustc_must_implement_one_of)
+                .get_attr(impl_trait_header.trait_ref.def_id, sym::rustc_must_implement_one_of)
                 .map(|attr| attr.span);
 
             missing_items_must_implement_one_of_err(

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -245,9 +245,9 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) -> Result<()
         // won't be allowed unless there's an *explicit* implementation of `Send`
         // for `T`
         hir::ItemKind::Impl(impl_) => {
-            let is_auto = tcx
-                .impl_trait_ref(def_id)
-                .is_some_and(|trait_ref| tcx.trait_is_auto(trait_ref.skip_binder().def_id));
+            let header = tcx.impl_trait_header(def_id);
+            let is_auto = header
+                .is_some_and(|header| tcx.trait_is_auto(header.skip_binder().trait_ref.def_id));
             let mut res = Ok(());
             if let (hir::Defaultness::Default { .. }, true) = (impl_.defaultness, is_auto) {
                 let sp = impl_.of_trait.as_ref().map_or(item.span, |t| t.path.span);
@@ -259,11 +259,12 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) -> Result<()
                     .emit());
             }
             // We match on both `ty::ImplPolarity` and `ast::ImplPolarity` just to get the `!` span.
-            match tcx.impl_polarity(def_id) {
-                ty::ImplPolarity::Positive => {
+            match header.map(|h| h.skip_binder().polarity) {
+                // `None` means this is an inherent impl
+                Some(ty::ImplPolarity::Positive) | None => {
                     res = res.and(check_impl(tcx, item, impl_.self_ty, &impl_.of_trait));
                 }
-                ty::ImplPolarity::Negative => {
+                Some(ty::ImplPolarity::Negative) => {
                     let ast::ImplPolarity::Negative(span) = impl_.polarity else {
                         bug!("impl_polarity query disagrees with impl's polarity in AST");
                     };
@@ -280,7 +281,7 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) -> Result<()
                         .emit());
                     }
                 }
-                ty::ImplPolarity::Reservation => {
+                Some(ty::ImplPolarity::Reservation) => {
                     // FIXME: what amount of WF checking do we need for reservation impls?
                 }
             }

compiler/rustc_hir_analysis/src/collect.rs

@@ -79,8 +79,7 @@ pub fn provide(providers: &mut Providers) {
         trait_def,
         adt_def,
         fn_sig,
-        impl_trait_ref,
-        impl_polarity,
+        impl_trait_header,
         coroutine_kind,
         coroutine_for_closure,
         collect_mod_item_types,
@@ -600,7 +599,7 @@ fn convert_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) {
         hir::ItemKind::Impl { .. } => {
             tcx.ensure().generics_of(def_id);
             tcx.ensure().type_of(def_id);
-            tcx.ensure().impl_trait_ref(def_id);
+            tcx.ensure().impl_trait_header(def_id);
             tcx.ensure().predicates_of(def_id);
         }
         hir::ItemKind::Trait(..) => {
@@ -1499,19 +1498,20 @@ fn suggest_impl_trait<'tcx>(
     None
 }
 
-fn impl_trait_ref(
+fn impl_trait_header(
     tcx: TyCtxt<'_>,
     def_id: LocalDefId,
-) -> Option<ty::EarlyBinder<ty::TraitRef<'_>>> {
+) -> Option<ty::EarlyBinder<ty::ImplTraitHeader<'_>>> {
     let icx = ItemCtxt::new(tcx, def_id);
-    let impl_ = tcx.hir().expect_item(def_id).expect_impl();
+    let item = tcx.hir().expect_item(def_id);
+    let impl_ = item.expect_impl();
     impl_
         .of_trait
         .as_ref()
         .map(|ast_trait_ref| {
             let selfty = tcx.type_of(def_id).instantiate_identity();
 
-            if let Some(ErrorGuaranteed { .. }) = check_impl_constness(
+            let trait_ref = if let Some(ErrorGuaranteed { .. }) = check_impl_constness(
                 tcx,
                 tcx.is_const_trait_impl_raw(def_id.to_def_id()),
                 ast_trait_ref,
@@ -1536,9 +1536,12 @@ fn impl_trait_ref(
                 icx.astconv().instantiate_mono_trait_ref(trait_ref, selfty)
             } else {
                 icx.astconv().instantiate_mono_trait_ref(ast_trait_ref, selfty)
-            }
+            };
+            ty::EarlyBinder::bind(ty::ImplTraitHeader {
+                trait_ref,
+                polarity: polarity_of_impl(tcx, def_id,  impl_, item.span)
+            })
         })
-        .map(ty::EarlyBinder::bind)
 }
 
 fn check_impl_constness(
@@ -1566,43 +1569,34 @@ fn check_impl_constness(
     }))
 }
 
-fn impl_polarity(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::ImplPolarity {
+fn polarity_of_impl(
+    tcx: TyCtxt<'_>,
+    def_id: LocalDefId,
+    impl_: &hir::Impl<'_>,
+    span: Span,
+) -> ty::ImplPolarity {
     let is_rustc_reservation = tcx.has_attr(def_id, sym::rustc_reservation_impl);
-    let item = tcx.hir().expect_item(def_id);
-    match &item.kind {
-        hir::ItemKind::Impl(hir::Impl {
-            polarity: hir::ImplPolarity::Negative(span),
-            of_trait,
-            ..
-        }) => {
+    match &impl_ {
+        hir::Impl { polarity: hir::ImplPolarity::Negative(span), of_trait, .. } => {
             if is_rustc_reservation {
                 let span = span.to(of_trait.as_ref().map_or(*span, |t| t.path.span));
                 tcx.dcx().span_err(span, "reservation impls can't be negative");
             }
             ty::ImplPolarity::Negative
         }
-        hir::ItemKind::Impl(hir::Impl {
-            polarity: hir::ImplPolarity::Positive,
-            of_trait: None,
-            ..
-        }) => {
+        hir::Impl { polarity: hir::ImplPolarity::Positive, of_trait: None, .. } => {
             if is_rustc_reservation {
-                tcx.dcx().span_err(item.span, "reservation impls can't be inherent");
+                tcx.dcx().span_err(span, "reservation impls can't be inherent");
             }
             ty::ImplPolarity::Positive
         }
-        hir::ItemKind::Impl(hir::Impl {
-            polarity: hir::ImplPolarity::Positive,
-            of_trait: Some(_),
-            ..
-        }) => {
+        hir::Impl { polarity: hir::ImplPolarity::Positive, of_trait: Some(_), .. } => {
             if is_rustc_reservation {
                 ty::ImplPolarity::Reservation
             } else {
                 ty::ImplPolarity::Positive
             }
         }
-        item => bug!("impl_polarity: {:?} not an impl", item),
     }
 }
 

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -3134,12 +3134,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     if self
                         .tcx
                         .all_impls(candidate.def_id)
-                        .filter(|imp_did| {
-                            self.tcx.impl_polarity(*imp_did) == ty::ImplPolarity::Negative
+                        .map(|imp_did| {
+                            self.tcx.impl_trait_header(imp_did).expect(
+                                "inherent impls can't be candidates, only trait impls can be",
+                            )
+                        })
+                        .filter(|header| {
+                            header.skip_binder().polarity == ty::ImplPolarity::Negative
                         })
-                        .any(|imp_did| {
-                            let imp =
-                                self.tcx.impl_trait_ref(imp_did).unwrap().instantiate_identity();
+                        .any(|header| {
+                            let imp = header.instantiate_identity().trait_ref;
                             let imp_simp =
                                 simplify_type(self.tcx, imp.self_ty(), TreatParams::ForLookup);
                             imp_simp.is_some_and(|s| s == simp_rcvr_ty)

compiler/rustc_incremental/src/persist/dirty_clean.rs

@@ -63,7 +63,7 @@ const BASE_HIR: &[&str] = &[
 
 /// `impl` implementation of struct/trait
 const BASE_IMPL: &[&str] =
-    &[label_strs::associated_item_def_ids, label_strs::generics_of, label_strs::impl_trait_ref];
+    &[label_strs::associated_item_def_ids, label_strs::generics_of, label_strs::impl_trait_header];
 
 /// DepNodes for mir_built/Optimized, which is relevant in "executable"
 /// code, i.e., functions+methods

compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

@@ -215,7 +215,7 @@ provide! { tcx, def_id, other, cdata,
     variances_of => { table }
     fn_sig => { table }
     codegen_fn_attrs => { table }
-    impl_trait_ref => { table }
+    impl_trait_header => { table }
     const_param_default => { table }
     object_lifetime_default => { table }
     thir_abstract_const => { table }
@@ -234,7 +234,6 @@ provide! { tcx, def_id, other, cdata,
     unused_generic_params => { cdata.root.tables.unused_generic_params.get(cdata, def_id.index) }
     def_kind => { cdata.def_kind(def_id.index) }
     impl_parent => { table }
-    impl_polarity => { table_direct }
     defaultness => { table_direct }
     constness => { table_direct }
     coerce_unsized_info => {

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1969,10 +1969,10 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             let def_id = id.owner_id.to_def_id();
 
             self.tables.defaultness.set_some(def_id.index, tcx.defaultness(def_id));
-            self.tables.impl_polarity.set_some(def_id.index, tcx.impl_polarity(def_id));
 
-            if of_trait && let Some(trait_ref) = tcx.impl_trait_ref(def_id) {
-                record!(self.tables.impl_trait_ref[def_id] <- trait_ref);
+            if of_trait && let Some(header) = tcx.impl_trait_header(def_id) {
+                record!(self.tables.impl_trait_header[def_id] <- header);
+                let trait_ref = header.map_bound(|h| h.trait_ref);
 
                 let trait_ref = trait_ref.instantiate_identity();
                 let simplified_self_ty = fast_reject::simplify_type(

compiler/rustc_metadata/src/rmeta/mod.rs

@@ -423,7 +423,7 @@ define_tables! {
     variances_of: Table<DefIndex, LazyArray<ty::Variance>>,
     fn_sig: Table<DefIndex, LazyValue<ty::EarlyBinder<ty::PolyFnSig<'static>>>>,
     codegen_fn_attrs: Table<DefIndex, LazyValue<CodegenFnAttrs>>,
-    impl_trait_ref: Table<DefIndex, LazyValue<ty::EarlyBinder<ty::TraitRef<'static>>>>,
+    impl_trait_header: Table<DefIndex, LazyValue<ty::EarlyBinder<ty::ImplTraitHeader<'static>>>>,
     const_param_default: Table<DefIndex, LazyValue<ty::EarlyBinder<rustc_middle::ty::Const<'static>>>>,
     object_lifetime_default: Table<DefIndex, LazyValue<ObjectLifetimeDefault>>,
     optimized_mir: Table<DefIndex, LazyValue<mir::Body<'static>>>,
@@ -433,7 +433,6 @@ define_tables! {
     promoted_mir: Table<DefIndex, LazyValue<IndexVec<mir::Promoted, mir::Body<'static>>>>,
     thir_abstract_const: Table<DefIndex, LazyValue<ty::EarlyBinder<ty::Const<'static>>>>,
     impl_parent: Table<DefIndex, RawDefId>,
-    impl_polarity: Table<DefIndex, ty::ImplPolarity>,
     constness: Table<DefIndex, hir::Constness>,
     defaultness: Table<DefIndex, hir::Defaultness>,
     // FIXME(eddyb) perhaps compute this on the fly if cheap enough?

compiler/rustc_middle/src/query/erase.rs

@@ -177,8 +177,8 @@ impl EraseType for Option<mir::DestructuredConstant<'_>> {
     type Result = [u8; size_of::<Option<mir::DestructuredConstant<'static>>>()];
 }
 
-impl EraseType for Option<ty::EarlyBinder<ty::TraitRef<'_>>> {
-    type Result = [u8; size_of::<Option<ty::EarlyBinder<ty::TraitRef<'static>>>>()];
+impl EraseType for Option<ty::EarlyBinder<ty::ImplTraitHeader<'_>>> {
+    type Result = [u8; size_of::<Option<ty::EarlyBinder<ty::ImplTraitHeader<'static>>>>()];
 }
 
 impl EraseType for Option<ty::EarlyBinder<Ty<'_>>> {