Auto merge of #129752 - compiler-errors:predicates-of-defaulted, r=<try>

Make supertrait and implied predicates queries defaulted

r? `@ghost` only last commit is meaningful

Author: bors

compiler/rustc_hir_analysis/src/collect.rs

@@ -420,7 +420,7 @@ impl<'tcx> HirTyLowerer<'tcx> for ItemCtxt<'tcx> {
         span: Span,
         def_id: LocalDefId,
         assoc_name: Ident,
-    ) -> ty::GenericPredicates<'tcx> {
+    ) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
         self.tcx.at(span).type_param_predicates((self.item_def_id, def_id, assoc_name))
     }
 

compiler/rustc_hir_analysis/src/collect/predicates_of.rs

@@ -580,24 +580,24 @@ pub(super) fn explicit_predicates_of<'tcx>(
 /// Ensures that the super-predicates of the trait with a `DefId`
 /// of `trait_def_id` are lowered and stored. This also ensures that
 /// the transitive super-predicates are lowered.
-pub(super) fn explicit_super_predicates_of(
-    tcx: TyCtxt<'_>,
+pub(super) fn explicit_super_predicates_of<'tcx>(
+    tcx: TyCtxt<'tcx>,
     trait_def_id: LocalDefId,
-) -> ty::GenericPredicates<'_> {
+) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
     implied_predicates_with_filter(tcx, trait_def_id.to_def_id(), PredicateFilter::SelfOnly)
 }
 
-pub(super) fn explicit_supertraits_containing_assoc_item(
-    tcx: TyCtxt<'_>,
+pub(super) fn explicit_supertraits_containing_assoc_item<'tcx>(
+    tcx: TyCtxt<'tcx>,
     (trait_def_id, assoc_name): (DefId, Ident),
-) -> ty::GenericPredicates<'_> {
+) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
     implied_predicates_with_filter(tcx, trait_def_id, PredicateFilter::SelfThatDefines(assoc_name))
 }
 
-pub(super) fn explicit_implied_predicates_of(
-    tcx: TyCtxt<'_>,
+pub(super) fn explicit_implied_predicates_of<'tcx>(
+    tcx: TyCtxt<'tcx>,
     trait_def_id: LocalDefId,
-) -> ty::GenericPredicates<'_> {
+) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
     implied_predicates_with_filter(
         tcx,
         trait_def_id.to_def_id(),
@@ -612,11 +612,11 @@ pub(super) fn explicit_implied_predicates_of(
 /// Ensures that the super-predicates of the trait with a `DefId`
 /// of `trait_def_id` are lowered and stored. This also ensures that
 /// the transitive super-predicates are lowered.
-pub(super) fn implied_predicates_with_filter(
-    tcx: TyCtxt<'_>,
+pub(super) fn implied_predicates_with_filter<'tcx>(
+    tcx: TyCtxt<'tcx>,
     trait_def_id: DefId,
     filter: PredicateFilter,
-) -> ty::GenericPredicates<'_> {
+) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
     let Some(trait_def_id) = trait_def_id.as_local() else {
         // if `assoc_name` is None, then the query should've been redirected to an
         // external provider
@@ -679,20 +679,16 @@ pub(super) fn implied_predicates_with_filter(
         _ => {}
     }
 
-    ty::GenericPredicates {
-        parent: None,
-        predicates: implied_bounds,
-        effects_min_tys: ty::List::empty(),
-    }
+    ty::EarlyBinder::bind(implied_bounds)
 }
 
 /// Returns the predicates defined on `item_def_id` of the form
 /// `X: Foo` where `X` is the type parameter `def_id`.
 #[instrument(level = "trace", skip(tcx))]
-pub(super) fn type_param_predicates(
-    tcx: TyCtxt<'_>,
+pub(super) fn type_param_predicates<'tcx>(
+    tcx: TyCtxt<'tcx>,
     (item_def_id, def_id, assoc_name): (LocalDefId, LocalDefId, Ident),
-) -> ty::GenericPredicates<'_> {
+) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
     use rustc_hir::*;
     use rustc_middle::ty::Ty;
 
@@ -713,18 +709,20 @@ pub(super) fn type_param_predicates(
         tcx.generics_of(item_def_id).parent.map(|def_id| def_id.expect_local())
     };
 
-    let mut result = parent
-        .map(|parent| {
-            let icx = ItemCtxt::new(tcx, parent);
-            icx.probe_ty_param_bounds(DUMMY_SP, def_id, assoc_name)
-        })
-        .unwrap_or_default();
+    let result = if let Some(parent) = parent {
+        let icx = ItemCtxt::new(tcx, parent);
+        icx.probe_ty_param_bounds(DUMMY_SP, def_id, assoc_name)
+    } else {
+        ty::EarlyBinder::bind(&[] as &[_])
+    };
     let mut extend = None;
 
     let item_hir_id = tcx.local_def_id_to_hir_id(item_def_id);
 
     let hir_node = tcx.hir_node(item_hir_id);
-    let Some(hir_generics) = hir_node.generics() else { return result };
+    let Some(hir_generics) = hir_node.generics() else {
+        return result;
+    };
     if let Node::Item(item) = hir_node
         && let ItemKind::Trait(..) = item.kind
         // Implied `Self: Trait` and supertrait bounds.
@@ -748,9 +746,10 @@ pub(super) fn type_param_predicates(
             _ => false,
         }),
     );
-    result.predicates =
-        tcx.arena.alloc_from_iter(result.predicates.iter().copied().chain(extra_predicates));
-    result
+
+    ty::EarlyBinder::bind(
+        tcx.arena.alloc_from_iter(result.skip_binder().iter().copied().chain(extra_predicates)),
+    )
 }
 
 impl<'tcx> ItemCtxt<'tcx> {

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -1761,7 +1761,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
                 break Some((bound_vars.into_iter().collect(), assoc_item));
             }
             let predicates = tcx.explicit_supertraits_containing_assoc_item((def_id, assoc_name));
-            let obligations = predicates.predicates.iter().filter_map(|&(pred, _)| {
+            let obligations = predicates.iter_identity_copied().filter_map(|(pred, _)| {
                 let bound_predicate = pred.kind();
                 match bound_predicate.skip_binder() {
                     ty::ClauseKind::Trait(data) => {

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -136,7 +136,7 @@ pub trait HirTyLowerer<'tcx> {
         span: Span,
         def_id: LocalDefId,
         assoc_name: Ident,
-    ) -> ty::GenericPredicates<'tcx>;
+    ) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]>;
 
     /// Lower an associated type to a projection.
     ///
@@ -831,13 +831,13 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         debug!(?ty_param_def_id, ?assoc_name, ?span);
         let tcx = self.tcx();
 
-        let predicates = &self.probe_ty_param_bounds(span, ty_param_def_id, assoc_name).predicates;
+        let predicates = &self.probe_ty_param_bounds(span, ty_param_def_id, assoc_name);
         debug!("predicates={:#?}", predicates);
 
         self.probe_single_bound_for_assoc_item(
             || {
                 let trait_refs = predicates
-                    .iter()
+                    .iter_identity_copied()
                     .filter_map(|(p, _)| Some(p.as_trait_clause()?.map_bound(|t| t.trait_ref)));
                 traits::transitive_bounds_that_define_assoc_item(tcx, trait_refs, assoc_name)
             },

compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs

@@ -263,27 +263,24 @@ impl<'tcx> HirTyLowerer<'tcx> for FnCtxt<'_, 'tcx> {
         _: Span,
         def_id: LocalDefId,
         _: Ident,
-    ) -> ty::GenericPredicates<'tcx> {
+    ) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
         let tcx = self.tcx;
         let item_def_id = tcx.hir().ty_param_owner(def_id);
         let generics = tcx.generics_of(item_def_id);
         let index = generics.param_def_id_to_index[&def_id.to_def_id()];
         // HACK(eddyb) should get the original `Span`.
         let span = tcx.def_span(def_id);
-        ty::GenericPredicates {
-            parent: None,
-            predicates: tcx.arena.alloc_from_iter(
-                self.param_env.caller_bounds().iter().filter_map(|predicate| {
-                    match predicate.kind().skip_binder() {
-                        ty::ClauseKind::Trait(data) if data.self_ty().is_param(index) => {
-                            Some((predicate, span))
-                        }
-                        _ => None,
+
+        ty::EarlyBinder::bind(tcx.arena.alloc_from_iter(
+            self.param_env.caller_bounds().iter().filter_map(|predicate| {
+                match predicate.kind().skip_binder() {
+                    ty::ClauseKind::Trait(data) if data.self_ty().is_param(index) => {
+                        Some((predicate, span))
                     }
-                }),
-            ),
-            effects_min_tys: ty::List::empty(),
-        }
+                    _ => None,
+                }
+            }),
+        ))
     }
 
     fn lower_assoc_ty(

compiler/rustc_infer/src/traits/util.rs

@@ -123,7 +123,7 @@ pub fn transitive_bounds_that_define_assoc_item<'tcx>(
 
             stack.extend(
                 tcx.explicit_supertraits_containing_assoc_item((trait_ref.def_id(), assoc_name))
-                    .instantiate_own_identity()
+                    .iter_identity_copied()
                     .map(|(clause, _)| clause.instantiate_supertrait(tcx, trait_ref))
                     .filter_map(|clause| clause.as_trait_clause())
                     // FIXME: Negative supertraits are elaborated here lol

compiler/rustc_lint/src/multiple_supertrait_upcastable.rs

@@ -45,8 +45,7 @@ impl<'tcx> LateLintPass<'tcx> for MultipleSupertraitUpcastable {
             let direct_super_traits_iter = cx
                 .tcx
                 .explicit_super_predicates_of(def_id)
-                .predicates
-                .into_iter()
+                .iter_identity_copied()
                 .filter_map(|(pred, _)| pred.as_trait_clause());
             if direct_super_traits_iter.count() > 1 {
                 cx.emit_span_lint(

compiler/rustc_metadata/src/rmeta/decoder.rs

@@ -1070,34 +1070,6 @@ impl<'a> CrateMetadataRef<'a> {
         )
     }
 
-    fn get_explicit_item_bounds<'tcx>(
-        self,
-        index: DefIndex,
-        tcx: TyCtxt<'tcx>,
-    ) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
-        let lazy = self.root.tables.explicit_item_bounds.get(self, index);
-        let output = if lazy.is_default() {
-            &mut []
-        } else {
-            tcx.arena.alloc_from_iter(lazy.decode((self, tcx)))
-        };
-        ty::EarlyBinder::bind(&*output)
-    }
-
-    fn get_explicit_item_super_predicates<'tcx>(
-        self,
-        index: DefIndex,
-        tcx: TyCtxt<'tcx>,
-    ) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
-        let lazy = self.root.tables.explicit_item_super_predicates.get(self, index);
-        let output = if lazy.is_default() {
-            &mut []
-        } else {
-            tcx.arena.alloc_from_iter(lazy.decode((self, tcx)))
-        };
-        ty::EarlyBinder::bind(&*output)
-    }
-
     fn get_variant(
         self,
         kind: DefKind,
@@ -1323,10 +1295,6 @@ impl<'a> CrateMetadataRef<'a> {
         self.root.tables.optimized_mir.get(self, id).is_some()
     }
 
-    fn cross_crate_inlinable(self, id: DefIndex) -> bool {
-        self.root.tables.cross_crate_inlinable.get(self, id)
-    }
-
     fn get_fn_has_self_parameter(self, id: DefIndex, sess: &'a Session) -> bool {
         self.root
             .tables

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

@@ -32,13 +32,20 @@ trait ProcessQueryValue<'tcx, T> {
     fn process_decoded(self, _tcx: TyCtxt<'tcx>, _err: impl Fn() -> !) -> T;
 }
 
-impl<T> ProcessQueryValue<'_, Option<T>> for Option<T> {
+impl<T> ProcessQueryValue<'_, T> for T {
     #[inline(always)]
-    fn process_decoded(self, _tcx: TyCtxt<'_>, _err: impl Fn() -> !) -> Option<T> {
+    fn process_decoded(self, _tcx: TyCtxt<'_>, _err: impl Fn() -> !) -> T {
         self
     }
 }
 
+impl<'tcx, T> ProcessQueryValue<'tcx, ty::EarlyBinder<'tcx, T>> for T {
+    #[inline(always)]
+    fn process_decoded(self, _tcx: TyCtxt<'_>, _err: impl Fn() -> !) -> ty::EarlyBinder<'tcx, T> {
+        ty::EarlyBinder::bind(self)
+    }
+}
+
 impl<T> ProcessQueryValue<'_, T> for Option<T> {
     #[inline(always)]
     fn process_decoded(self, _tcx: TyCtxt<'_>, err: impl Fn() -> !) -> T {
@@ -69,6 +76,24 @@ impl<'a, 'tcx, T: Copy + Decodable<DecodeContext<'a, 'tcx>>> ProcessQueryValue<'
     }
 }
 
+impl<'a, 'tcx, T: Copy + Decodable<DecodeContext<'a, 'tcx>>>
+    ProcessQueryValue<'tcx, ty::EarlyBinder<'tcx, &'tcx [T]>>
+    for Option<DecodeIterator<'a, 'tcx, T>>
+{
+    #[inline(always)]
+    fn process_decoded(
+        self,
+        tcx: TyCtxt<'tcx>,
+        _err: impl Fn() -> !,
+    ) -> ty::EarlyBinder<'tcx, &'tcx [T]> {
+        ty::EarlyBinder::bind(if let Some(iter) = self {
+            tcx.arena.alloc_from_iter(iter)
+        } else {
+            &[]
+        })
+    }
+}
+
 impl<'a, 'tcx, T: Copy + Decodable<DecodeContext<'a, 'tcx>>>
     ProcessQueryValue<'tcx, Option<&'tcx [T]>> for Option<DecodeIterator<'a, 'tcx, T>>
 {
@@ -103,7 +128,12 @@ macro_rules! provide_one {
         provide_one! {
             $tcx, $def_id, $other, $cdata, $name => {
                 let lazy = $cdata.root.tables.$name.get($cdata, $def_id.index);
-                if lazy.is_default() { &[] } else { $tcx.arena.alloc_from_iter(lazy.decode(($cdata, $tcx))) }
+                let value = if lazy.is_default() {
+                    &[] as &[_]
+                } else {
+                    $tcx.arena.alloc_from_iter(lazy.decode(($cdata, $tcx)))
+                };
+                value.process_decoded($tcx, || panic!("{:?} does not have a {:?}", $def_id, stringify!($name)))
             }
         }
     };
@@ -212,15 +242,15 @@ impl IntoArgs for (CrateNum, SimplifiedType) {
 }
 
 provide! { tcx, def_id, other, cdata,
-    explicit_item_bounds => { cdata.get_explicit_item_bounds(def_id.index, tcx) }
-    explicit_item_super_predicates => { cdata.get_explicit_item_super_predicates(def_id.index, tcx) }
+    explicit_item_bounds => { table_defaulted_array }
+    explicit_item_super_predicates => { table_defaulted_array }
     explicit_predicates_of => { table }
     generics_of => { table }
     inferred_outlives_of => { table_defaulted_array }
-    explicit_super_predicates_of => { table }
-    explicit_implied_predicates_of => { table }
+    explicit_super_predicates_of => { table_defaulted_array }
+    explicit_implied_predicates_of => { table_defaulted_array }
     type_of => { table }
-    type_alias_is_lazy => { cdata.root.tables.type_alias_is_lazy.get(cdata, def_id.index) }
+    type_alias_is_lazy => { table_direct }
     variances_of => { table }
     fn_sig => { table }
     codegen_fn_attrs => { table }
@@ -241,7 +271,7 @@ provide! { tcx, def_id, other, cdata,
     lookup_default_body_stability => { table }
     lookup_deprecation_entry => { table }
     params_in_repr => { table }
-    unused_generic_params => { cdata.root.tables.unused_generic_params.get(cdata, def_id.index) }
+    unused_generic_params => { table_direct }
     def_kind => { cdata.def_kind(def_id.index) }
     impl_parent => { table }
     defaultness => { table_direct }
@@ -287,9 +317,7 @@ provide! { tcx, def_id, other, cdata,
             .process_decoded(tcx, || panic!("{def_id:?} does not have trait_impl_trait_tys")))
     }
 
-    associated_type_for_effects => {
-        table
-    }
+    associated_type_for_effects => { table }
     associated_types_for_impl_traits_in_associated_fn => { table_defaulted_array }
 
     visibility => { cdata.get_visibility(def_id.index) }
@@ -310,7 +338,7 @@ provide! { tcx, def_id, other, cdata,
     item_attrs => { tcx.arena.alloc_from_iter(cdata.get_item_attrs(def_id.index, tcx.sess)) }
     is_mir_available => { cdata.is_item_mir_available(def_id.index) }
     is_ctfe_mir_available => { cdata.is_ctfe_mir_available(def_id.index) }
-    cross_crate_inlinable => { cdata.cross_crate_inlinable(def_id.index) }
+    cross_crate_inlinable => { table_direct }
 
     dylib_dependency_formats => { cdata.get_dylib_dependency_formats(tcx) }
     is_private_dep => { cdata.private_dep }