bjoernager/rust
bjoernager/rust
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implement new effects desugaring

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This commit is contained in:
Deadbeef 2024-06-14 12:16:15 +00:00
parent 99f77a2eda
commit 72e8244e64
50 changed files with 636 additions and 228 deletions
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168
compiler/rustc_ty_utils/src/assoc.rs
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@ -4,8 +4,9 @@ use rustc_hir::def::DefKind;
use rustc_hir::def_id::{DefId, DefIdMap, LocalDefId};
use rustc_hir::intravisit::{self, Visitor};
use rustc_middle::query::Providers;
use rustc_middle::ty::{self, ImplTraitInTraitData, TyCtxt};
use rustc_middle::ty::{self, ImplTraitInTraitData, Ty, TyCtxt};
use rustc_middle::{bug, span_bug};
use rustc_span::sym;
use rustc_span::symbol::kw;
pub(crate) fn provide(providers: &mut Providers) {
@ -14,6 +15,7 @@ pub(crate) fn provide(providers: &mut Providers) {
associated_item_def_ids,
associated_items,
associated_types_for_impl_traits_in_associated_fn,
associated_type_for_effects,
associated_type_for_impl_trait_in_trait,
impl_item_implementor_ids,
..*providers
@ -44,7 +46,8 @@ fn associated_item_def_ids(tcx: TyCtxt<'_>, def_id: LocalDefId) -> &[DefId] {
)
})
.copied(),
),
)
.chain(tcx.associated_type_for_effects(def_id)),
)
}
hir::ItemKind::Impl(impl_) => {
@ -70,7 +73,8 @@ fn associated_item_def_ids(tcx: TyCtxt<'_>, def_id: LocalDefId) -> &[DefId] {
)
})
.copied()
})),
}))
.chain(tcx.associated_type_for_effects(def_id)),
)
}
_ => span_bug!(item.span, "associated_item_def_ids: not impl or trait"),
@ -143,6 +147,7 @@ fn associated_item_from_trait_item_ref(trait_item_ref: &hir::TraitItemRef) -> ty
container: ty::TraitContainer,
fn_has_self_parameter: has_self,
opt_rpitit_info: None,
is_effects_desugaring: false,
}
}
@ -162,6 +167,161 @@ fn associated_item_from_impl_item_ref(impl_item_ref: &hir::ImplItemRef) -> ty::A
container: ty::ImplContainer,
fn_has_self_parameter: has_self,
opt_rpitit_info: None,
is_effects_desugaring: false,
}
}
/// Given an `def_id` of a trait or a trait impl:
///
/// If `def_id` is a trait that has `#[const_trait]`, then it synthesizes
/// a new def id corresponding to a new associated type for the effects.
///
/// If `def_id` is an impl, then synthesize the associated type according
/// to the constness of the impl.
fn associated_type_for_effects(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<DefId> {
match tcx.def_kind(def_id) {
DefKind::Trait => {
let trait_def_id = def_id;
let Some(attr) = tcx.get_attr(def_id, sym::const_trait) else {
return None;
};
let span = attr.span;
let trait_assoc_ty = tcx.at(span).create_def(trait_def_id, kw::Empty, DefKind::AssocTy);
let local_def_id = trait_assoc_ty.def_id();
let def_id = local_def_id.to_def_id();
trait_assoc_ty.feed_hir();
// Copy span of the attribute.
trait_assoc_ty.def_ident_span(Some(span));
trait_assoc_ty.associated_item(ty::AssocItem {
name: kw::Empty,
kind: ty::AssocKind::Type,
def_id,
trait_item_def_id: None,
container: ty::TraitContainer,
fn_has_self_parameter: false,
opt_rpitit_info: None,
is_effects_desugaring: true,
});
// visibility is public.
trait_assoc_ty.visibility(ty::Visibility::Public);
// No default type
trait_assoc_ty.defaultness(hir::Defaultness::Default { has_value: false });
trait_assoc_ty.is_type_alias_impl_trait(false);
// Copy generics_of of the trait, making the trait as parent.
trait_assoc_ty.generics_of({
let parent_generics = tcx.generics_of(trait_def_id);
let parent_count = parent_generics.parent_count + parent_generics.own_params.len();
ty::Generics {
parent: Some(trait_def_id.to_def_id()),
parent_count,
own_params: vec![],
param_def_id_to_index: parent_generics.param_def_id_to_index.clone(),
has_self: false,
has_late_bound_regions: None,
host_effect_index: parent_generics.host_effect_index,
}
});
trait_assoc_ty.explicit_item_bounds(ty::EarlyBinder::bind(&[]));
trait_assoc_ty.explicit_item_super_predicates(ty::EarlyBinder::bind(&[]));
// There are no inferred outlives for the synthesized associated type.
trait_assoc_ty.inferred_outlives_of(&[]);
Some(def_id)
}
DefKind::Impl { .. } => {
let impl_def_id = def_id;
let Some(trait_id) = tcx.trait_id_of_impl(def_id.to_def_id()) else { return None };
// first get the DefId of the assoc type on the trait, if there is not,
// then we don't need to generate it on the impl.
let Some(trait_assoc_id) = tcx.associated_type_for_effects(trait_id) else {
return None;
};
// TODO span is bad
let span = tcx.def_ident_span(def_id).unwrap();
let impl_assoc_ty = tcx.at(span).create_def(def_id, kw::Empty, DefKind::AssocTy);
let local_def_id = impl_assoc_ty.def_id();
let def_id = local_def_id.to_def_id();
impl_assoc_ty.feed_hir();
impl_assoc_ty.def_ident_span(Some(span));
impl_assoc_ty.associated_item(ty::AssocItem {
name: kw::Empty,
kind: ty::AssocKind::Type,
def_id,
trait_item_def_id: Some(trait_assoc_id),
container: ty::ImplContainer,
fn_has_self_parameter: false,
opt_rpitit_info: None,
is_effects_desugaring: true,
});
// visibility is public.
impl_assoc_ty.visibility(ty::Visibility::Public);
// no default value.
impl_assoc_ty.defaultness(hir::Defaultness::Final);
// set the type of the associated type! If this is a const impl,
// we set to Maybe, otherwise we set to `Runtime`.
let type_def_id = if tcx.is_const_trait_impl_raw(impl_def_id.to_def_id()) {
tcx.require_lang_item(hir::LangItem::EffectsMaybe, Some(span))
} else {
tcx.require_lang_item(hir::LangItem::EffectsRuntime, Some(span))
};
// TODO this is wrong
impl_assoc_ty.type_of(ty::EarlyBinder::bind(Ty::new_adt(
tcx,
tcx.adt_def(type_def_id),
ty::GenericArgs::empty(),
)));
// Copy generics_of of the impl, making the impl as parent.
impl_assoc_ty.generics_of({
let parent_generics = tcx.generics_of(impl_def_id);
let parent_count = parent_generics.parent_count + parent_generics.own_params.len();
ty::Generics {
parent: Some(impl_def_id.to_def_id()),
parent_count,
own_params: vec![],
param_def_id_to_index: parent_generics.param_def_id_to_index.clone(),
has_self: false,
has_late_bound_regions: None,
host_effect_index: parent_generics.host_effect_index,
}
});
impl_assoc_ty.explicit_item_bounds(ty::EarlyBinder::bind(&[]));
impl_assoc_ty.explicit_item_super_predicates(ty::EarlyBinder::bind(&[]));
// There are no inferred outlives for the synthesized associated type.
impl_assoc_ty.inferred_outlives_of(&[]);
Some(def_id)
}
def_kind => bug!(
"associated_type_for_effects: {:?} should be Trait or Impl but is {:?}",
def_id,
def_kind
),
}
}
@ -275,6 +435,7 @@ fn associated_type_for_impl_trait_in_trait(
fn_def_id: fn_def_id.to_def_id(),
opaque_def_id: opaque_ty_def_id.to_def_id(),
}),
is_effects_desugaring: false,
});
// Copy visility of the containing function.
@ -326,6 +487,7 @@ fn associated_type_for_impl_trait_in_impl(
container: ty::ImplContainer,
fn_has_self_parameter: false,
opt_rpitit_info: Some(ImplTraitInTraitData::Impl { fn_def_id: impl_fn_def_id.to_def_id() }),
is_effects_desugaring: false,
});
// Copy visility of the containing function.