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Rename ~const Drop to ~const Destruct

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This commit is contained in:
Deadbeef 2022-03-21 16:52:41 +11:00
parent 4df2a28aee
commit 1f3ee7f32e
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GPG key ID: 6D017A96D8E6C2F9
32 changed files with 296 additions and 192 deletions
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60
compiler/rustc_trait_selection/src/traits/select/confirmation.rs
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@ -8,7 +8,6 @@
//! https://rustc-dev-guide.rust-lang.org/traits/resolution.html#confirmation
use rustc_data_structures::stack::ensure_sufficient_stack;
use rustc_hir::lang_items::LangItem;
use rustc_hir::Constness;
use rustc_index::bit_set::GrowableBitSet;
use rustc_infer::infer::InferOk;
use rustc_infer::infer::LateBoundRegionConversionTime::HigherRankedType;
@ -29,9 +28,9 @@ use crate::traits::TraitNotObjectSafe;
use crate::traits::VtblSegment;
use crate::traits::{BuiltinDerivedObligation, ImplDerivedObligation};
use crate::traits::{
ImplSourceAutoImplData, ImplSourceBuiltinData, ImplSourceClosureData, ImplSourceConstDropData,
ImplSourceDiscriminantKindData, ImplSourceFnPointerData, ImplSourceGeneratorData,
ImplSourceObjectData, ImplSourcePointeeData, ImplSourceTraitAliasData,
ImplSourceAutoImplData, ImplSourceBuiltinData, ImplSourceClosureData,
ImplSourceConstDestructData, ImplSourceDiscriminantKindData, ImplSourceFnPointerData,
ImplSourceGeneratorData, ImplSourceObjectData, ImplSourcePointeeData, ImplSourceTraitAliasData,
ImplSourceTraitUpcastingData, ImplSourceUserDefinedData,
};
use crate::traits::{ObjectCastObligation, PredicateObligation, TraitObligation};
@ -156,9 +155,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
Ok(ImplSource::TraitUpcasting(data))
}
ConstDropCandidate(def_id) => {
let data = self.confirm_const_drop_candidate(obligation, def_id)?;
Ok(ImplSource::ConstDrop(data))
ConstDestructCandidate(def_id) => {
let data = self.confirm_const_destruct_candidate(obligation, def_id)?;
Ok(ImplSource::ConstDestruct(data))
}
}
}
@ -1037,14 +1036,24 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
Ok(ImplSourceBuiltinData { nested })
}
fn confirm_const_drop_candidate(
fn confirm_const_destruct_candidate(
&mut self,
obligation: &TraitObligation<'tcx>,
impl_def_id: Option<DefId>,
) -> Result<ImplSourceConstDropData<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
// `~const Drop` in a non-const environment is always trivially true, since our type is `Drop`
if obligation.param_env.constness() == Constness::NotConst {
return Ok(ImplSourceConstDropData { nested: vec![] });
) -> Result<ImplSourceConstDestructData<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
// `~const Destruct` in a non-const environment is always trivially true, since our type is `Drop`
if !obligation.is_const() {
return Ok(ImplSourceConstDestructData { nested: vec![] });
}
let drop_trait = self.tcx().require_lang_item(LangItem::Drop, None);
// FIXME: remove if statement below when beta is bumped
#[cfg(bootstrap)]
{}
if obligation.predicate.skip_binder().def_id() == drop_trait
{
return Ok(ImplSourceConstDestructData { nested: vec![] });
}
let tcx = self.tcx();
@ -1054,9 +1063,26 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
let cause = obligation.derived_cause(BuiltinDerivedObligation);
// If we have a custom `impl const Drop`, then
// first check it like a regular impl candidate
// first check it like a regular impl candidate.
// This is copied from confirm_impl_candidate but remaps the predicate to `~const Drop` beforehand.
if let Some(impl_def_id) = impl_def_id {
nested.extend(self.confirm_impl_candidate(obligation, impl_def_id).nested);
let obligations = self.infcx.commit_unconditionally(|_| {
let mut new_obligation = obligation.clone();
new_obligation.predicate = new_obligation.predicate.map_bound(|mut trait_pred| { trait_pred.trait_ref.def_id = drop_trait; trait_pred });
let substs = self.rematch_impl(impl_def_id, &new_obligation);
debug!(?substs, "impl substs");
let cause = obligation.derived_cause(ImplDerivedObligation);
ensure_sufficient_stack(|| {
self.vtable_impl(
impl_def_id,
substs,
cause,
new_obligation.recursion_depth + 1,
new_obligation.param_env,
)
})
});
nested.extend(obligations.nested);
}
// We want to confirm the ADT's fields if we have an ADT
@ -1114,7 +1140,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
self_ty
.rebind(ty::TraitPredicate {
trait_ref: ty::TraitRef {
def_id: self.tcx().require_lang_item(LangItem::Drop, None),
def_id: self.tcx().require_lang_item(LangItem::Destruct, None),
substs: self.tcx().mk_substs_trait(nested_ty, &[]),
},
constness: ty::BoundConstness::ConstIfConst,
@ -1140,7 +1166,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
let predicate = self_ty
.rebind(ty::TraitPredicate {
trait_ref: ty::TraitRef {
def_id: self.tcx().require_lang_item(LangItem::Drop, None),
def_id: self.tcx().require_lang_item(LangItem::Destruct, None),
substs: self.tcx().mk_substs_trait(nested_ty, &[]),
},
constness: ty::BoundConstness::ConstIfConst,
@ -1158,6 +1184,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
}
Ok(ImplSourceConstDropData { nested })
Ok(ImplSourceConstDestructData { nested })
}
}