Auto merge of rust-lang#139018 - oli-obk:incremental-trait-impls, r=<try>

Decouple trait impls of different traits wrt incremental

Adding a trait impl for `Foo` unconditionally affected all queries that are interested in a completely independent trait `Bar`. Let's see if perf has any effect on this. If not, we can land it and I poke further at it to see if we can decouple things further. We probably don't have a good perf test for it tho.

r? `@ghost`

Author: bors

compiler/rustc_hir_analysis/src/check/always_applicable.rs

@@ -36,10 +36,8 @@ use crate::hir::def_id::{DefId, LocalDefId};
 ///    cannot do `struct S<T>; impl<T:Clone> Drop for S<T> { ... }`).
 pub(crate) fn check_drop_impl(
     tcx: TyCtxt<'_>,
-    drop_impl_did: DefId,
+    drop_impl_did: LocalDefId,
 ) -> Result<(), ErrorGuaranteed> {
-    let drop_impl_did = drop_impl_did.expect_local();
-
     match tcx.impl_polarity(drop_impl_did) {
         ty::ImplPolarity::Positive => {}
         ty::ImplPolarity::Negative => {

compiler/rustc_hir_analysis/src/check/mod.rs

@@ -114,11 +114,11 @@ pub fn provide(providers: &mut Providers) {
 }
 
 fn adt_destructor(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<ty::Destructor> {
-    tcx.calculate_dtor(def_id.to_def_id(), always_applicable::check_drop_impl)
+    tcx.calculate_dtor(def_id, always_applicable::check_drop_impl)
 }
 
 fn adt_async_destructor(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<ty::AsyncDestructor> {
-    tcx.calculate_async_dtor(def_id.to_def_id(), always_applicable::check_drop_impl)
+    tcx.calculate_async_dtor(def_id, always_applicable::check_drop_impl)
 }
 
 /// Given a `DefId` for an opaque type in return position, find its parent item's return

compiler/rustc_hir_analysis/src/coherence/mod.rs

@@ -153,9 +153,12 @@ pub(crate) fn provide(providers: &mut Providers) {
 }
 
 fn coherent_trait(tcx: TyCtxt<'_>, def_id: DefId) -> Result<(), ErrorGuaranteed> {
+    let impls = tcx.local_trait_impls(def_id);
     // If there are no impls for the trait, then "all impls" are trivially coherent and we won't check anything
     // anyway. Thus we bail out even before the specialization graph, avoiding the dep_graph edge.
-    let Some(impls) = tcx.all_local_trait_impls(()).get(&def_id) else { return Ok(()) };
+    if impls.is_empty() {
+        return Ok(());
+    }
     // Trigger building the specialization graph for the trait. This will detect and report any
     // overlap errors.
     let mut res = tcx.ensure_ok().specialization_graph_of(def_id);

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

@@ -330,14 +330,8 @@ provide! { tcx, def_id, other, cdata,
 
     visibility => { cdata.get_visibility(def_id.index) }
     adt_def => { cdata.get_adt_def(def_id.index, tcx) }
-    adt_destructor => {
-        let _ = cdata;
-        tcx.calculate_dtor(def_id, |_,_| Ok(()))
-    }
-    adt_async_destructor => {
-        let _ = cdata;
-        tcx.calculate_async_dtor(def_id, |_,_| Ok(()))
-    }
+    adt_destructor => { table }
+    adt_async_destructor => { table }
     associated_item_def_ids => {
         tcx.arena.alloc_from_iter(cdata.get_associated_item_or_field_def_ids(def_id.index))
     }

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1633,6 +1633,14 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 record!(self.tables.fn_sig[variant.def_id] <- fn_sig);
             }
         }
+
+        if let Some(destructor) = tcx.adt_destructor(local_def_id) {
+            record!(self.tables.adt_destructor[def_id] <- destructor);
+        }
+
+        if let Some(destructor) = tcx.adt_async_destructor(local_def_id) {
+            record!(self.tables.adt_async_destructor[def_id] <- destructor);
+        }
     }
 
     #[instrument(level = "debug", skip(self))]

compiler/rustc_metadata/src/rmeta/mod.rs

@@ -446,6 +446,8 @@ define_tables! {
     fn_arg_names: Table<DefIndex, LazyArray<Option<Ident>>>,
     coroutine_kind: Table<DefIndex, hir::CoroutineKind>,
     coroutine_for_closure: Table<DefIndex, RawDefId>,
+    adt_destructor: Table<DefIndex, LazyValue<ty::Destructor>>,
+    adt_async_destructor: Table<DefIndex, LazyValue<ty::AsyncDestructor>>,
     coroutine_by_move_body_def_id: Table<DefIndex, RawDefId>,
     eval_static_initializer: Table<DefIndex, LazyValue<mir::interpret::ConstAllocation<'static>>>,
     trait_def: Table<DefIndex, LazyValue<ty::TraitDef>>,

compiler/rustc_middle/src/hir/map.rs

@@ -368,7 +368,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn hir_trait_impls(self, trait_did: DefId) -> &'tcx [LocalDefId] {
-        self.all_local_trait_impls(()).get(&trait_did).map_or(&[], |xs| &xs[..])
+        self.local_trait_impls(trait_did)
     }
 
     /// Gets the attributes on the crate. This is preferable to

compiler/rustc_middle/src/hir/mod.rs

@@ -238,6 +238,8 @@ pub fn provide(providers: &mut Providers) {
         }
     };
     providers.all_local_trait_impls = |tcx, ()| &tcx.resolutions(()).trait_impls;
+    providers.local_trait_impls =
+        |tcx, trait_id| tcx.resolutions(()).trait_impls.get(&trait_id).map_or(&[], |xs| &xs[..]);
     providers.expn_that_defined =
         |tcx, id| tcx.resolutions(()).expn_that_defined.get(&id).copied().unwrap_or(ExpnId::root());
     providers.in_scope_traits_map = |tcx, id| {

compiler/rustc_middle/src/query/mod.rs

@@ -1502,6 +1502,11 @@ rustc_queries! {
         desc { "finding local trait impls" }
     }
 
+    /// Return all `impl` blocks of the given trait in the current crate.
+    query local_trait_impls(trait_id: DefId) -> &'tcx [LocalDefId] {
+        desc { "finding local trait impls of `{}`", tcx.def_path_str(trait_id) }
+    }
+
     /// Given a trait `trait_id`, return all known `impl` blocks.
     query trait_impls_of(trait_id: DefId) -> &'tcx ty::trait_def::TraitImpls {
         arena_cache

compiler/rustc_middle/src/ty/parameterized.rs

@@ -65,9 +65,11 @@ trivially_parameterized_over_tcx! {
     crate::middle::lib_features::FeatureStability,
     crate::middle::resolve_bound_vars::ObjectLifetimeDefault,
     crate::mir::ConstQualifs,
+    ty::AsyncDestructor,
     ty::AssocItemContainer,
     ty::Asyncness,
     ty::DeducedParamAttrs,
+    ty::Destructor,
     ty::Generics,
     ty::ImplPolarity,
     ty::ImplTraitInTraitData,