Auto merge of #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,

compiler/rustc_middle/src/ty/util.rs

@@ -389,24 +389,29 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Calculate the destructor of a given type.
     pub fn calculate_dtor(
         self,
-        adt_did: DefId,
-        validate: impl Fn(Self, DefId) -> Result<(), ErrorGuaranteed>,
+        adt_did: LocalDefId,
+        validate: impl Fn(Self, LocalDefId) -> Result<(), ErrorGuaranteed>,
     ) -> Option<ty::Destructor> {
         let drop_trait = self.lang_items().drop_trait()?;
         self.ensure_ok().coherent_trait(drop_trait).ok()?;
 
-        let ty = self.type_of(adt_did).instantiate_identity();
         let mut dtor_candidate = None;
-        self.for_each_relevant_impl(drop_trait, ty, |impl_did| {
+        // `Drop` impls can only be written in the same crate as the adt, and cannot be blanket impls
+        for &impl_did in self.local_trait_impls(drop_trait) {
+            let Some(adt_def) = self.type_of(impl_did).skip_binder().ty_adt_def() else { continue };
+            if adt_def.did() != adt_did.to_def_id() {
+                continue;
+            }
+
             if validate(self, impl_did).is_err() {
                 // Already `ErrorGuaranteed`, no need to delay a span bug here.
-                return;
+                continue;
             }
 
             let Some(item_id) = self.associated_item_def_ids(impl_did).first() else {
                 self.dcx()
                     .span_delayed_bug(self.def_span(impl_did), "Drop impl without drop function");
-                return;
+                continue;
             };
 
             if let Some((old_item_id, _)) = dtor_candidate {
@@ -417,7 +422,7 @@ impl<'tcx> TyCtxt<'tcx> {
             }
 
             dtor_candidate = Some((*item_id, self.impl_trait_header(impl_did).unwrap().constness));
-        });
+        }
 
         let (did, constness) = dtor_candidate?;
         Some(ty::Destructor { did, constness })
@@ -426,26 +431,31 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Calculate the async destructor of a given type.
     pub fn calculate_async_dtor(
         self,
-        adt_did: DefId,
-        validate: impl Fn(Self, DefId) -> Result<(), ErrorGuaranteed>,
+        adt_did: LocalDefId,
+        validate: impl Fn(Self, LocalDefId) -> Result<(), ErrorGuaranteed>,
     ) -> Option<ty::AsyncDestructor> {
         let async_drop_trait = self.lang_items().async_drop_trait()?;
         self.ensure_ok().coherent_trait(async_drop_trait).ok()?;
 
-        let ty = self.type_of(adt_did).instantiate_identity();
         let mut dtor_candidate = None;
-        self.for_each_relevant_impl(async_drop_trait, ty, |impl_did| {
+        // `AsyncDrop` impls can only be written in the same crate as the adt, and cannot be blanket impls
+        for &impl_did in self.local_trait_impls(async_drop_trait) {
+            let Some(adt_def) = self.type_of(impl_did).skip_binder().ty_adt_def() else { continue };
+            if adt_def.did() != adt_did.to_def_id() {
+                continue;
+            }
+
             if validate(self, impl_did).is_err() {
                 // Already `ErrorGuaranteed`, no need to delay a span bug here.
-                return;
+                continue;
             }
 
             let [future, ctor] = self.associated_item_def_ids(impl_did) else {
                 self.dcx().span_delayed_bug(
                     self.def_span(impl_did),
                     "AsyncDrop impl without async_drop function or Dropper type",
                 );
-                return;
+                continue;
             };
 
             if let Some((_, _, old_impl_did)) = dtor_candidate {
@@ -456,7 +466,7 @@ impl<'tcx> TyCtxt<'tcx> {
             }
 
             dtor_candidate = Some((*future, *ctor, impl_did));
-        });
+        }
 
         let (future, ctor, _) = dtor_candidate?;
         Some(ty::AsyncDestructor { future, ctor })

compiler/rustc_mir_transform/src/check_const_item_mutation.rs

@@ -53,9 +53,10 @@ impl<'tcx> ConstMutationChecker<'_, 'tcx> {
         //
         //     #[const_mutation_allowed]
         //     pub const LOG: Log = Log { msg: "" };
-        match self.tcx.calculate_dtor(def_id, |_, _| Ok(())) {
-            Some(_) => None,
-            None => Some(def_id),
+        match self.tcx.type_of(def_id).skip_binder().ty_adt_def().map(|adt| adt.has_dtor(self.tcx))
+        {
+            Some(true) => None,
+            Some(false) | None => Some(def_id),
         }
     }
 

compiler/rustc_monomorphize/messages.ftl

@@ -48,7 +48,7 @@ monomorphize_large_assignments =
     .note = The current maximum size is {$limit}, but it can be customized with the move_size_limit attribute: `#![move_size_limit = "..."]`
 
 monomorphize_no_optimized_mir =
-    missing optimized MIR for an item in the crate `{$crate_name}`
+    missing optimized MIR for `{$instance}` in the crate `{$crate_name}`
     .note = missing optimized MIR for this item (was the crate `{$crate_name}` compiled with `--emit=metadata`?)
 
 monomorphize_recursion_limit =

compiler/rustc_monomorphize/src/collector.rs

@@ -989,6 +989,7 @@ fn should_codegen_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) ->
         tcx.dcx().emit_fatal(NoOptimizedMir {
             span: tcx.def_span(def_id),
             crate_name: tcx.crate_name(def_id.krate),
+            instance: instance.to_string(),
         });
     }
 

compiler/rustc_monomorphize/src/errors.rs

@@ -24,6 +24,7 @@ pub(crate) struct NoOptimizedMir {
     #[note]
     pub span: Span,
     pub crate_name: Symbol,
+    pub instance: String,
 }
 
 #[derive(LintDiagnostic)]

src/tools/clippy/clippy_lints/src/derive.rs

@@ -324,11 +324,9 @@ fn check_copy_clone<'tcx>(cx: &LateContext<'tcx>, item: &Item<'_>, trait_ref: &h
     // there's a Copy impl for any instance of the adt.
     if !is_copy(cx, ty) {
         if ty_subs.non_erasable_generics().next().is_some() {
-            let has_copy_impl = cx.tcx.all_local_trait_impls(()).get(&copy_id).is_some_and(|impls| {
-                impls.iter().any(|&id| {
-                    matches!(cx.tcx.type_of(id).instantiate_identity().kind(), ty::Adt(adt, _)
+            let has_copy_impl = cx.tcx.local_trait_impls(copy_id).iter().any(|&id| {
+                matches!(cx.tcx.type_of(id).instantiate_identity().kind(), ty::Adt(adt, _)
                                         if ty_adt.did() == adt.did())
-                })
             });
             if !has_copy_impl {
                 return;

tests/ui/rmeta/no_optitimized_mir.rs

@@ -10,4 +10,4 @@ fn main() {
     rmeta_meta::missing_optimized_mir();
 }
 
-//~? ERROR missing optimized MIR for an item in the crate `rmeta_meta`
+//~? ERROR missing optimized MIR for `missing_optimized_mir` in the crate `rmeta_meta`

tests/ui/rmeta/no_optitimized_mir.stderr

@@ -1,4 +1,4 @@
-error: missing optimized MIR for an item in the crate `rmeta_meta`
+error: missing optimized MIR for `missing_optimized_mir` in the crate `rmeta_meta`
    |
 note: missing optimized MIR for this item (was the crate `rmeta_meta` compiled with `--emit=metadata`?)
   --> $DIR/auxiliary/rmeta-meta.rs:10:1