diff options
Diffstat (limited to 'compiler')
6 files changed, 54 insertions, 33 deletions
diff --git a/compiler/rustc_const_eval/src/transform/check_consts/check.rs b/compiler/rustc_const_eval/src/transform/check_consts/check.rs index bcc42a376ea..e604f4c1aec 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs @@ -22,7 +22,7 @@ use std::mem; use std::ops::{ControlFlow, Deref}; use super::ops::{self, NonConstOp, Status}; -use super::qualifs::{self, CustomEq, HasMutInterior, NeedsDrop}; +use super::qualifs::{self, CustomEq, HasMutInterior, NeedsDrop, NeedsNonConstDrop}; use super::resolver::FlowSensitiveAnalysis; use super::{ConstCx, Qualif}; use crate::const_eval::is_unstable_const_fn; @@ -35,7 +35,7 @@ type QualifResults<'mir, 'tcx, Q> = pub struct Qualifs<'mir, 'tcx> { has_mut_interior: Option<QualifResults<'mir, 'tcx, HasMutInterior>>, needs_drop: Option<QualifResults<'mir, 'tcx, NeedsDrop>>, - // needs_non_const_drop: Option<QualifResults<'mir, 'tcx, NeedsNonConstDrop>>, + needs_non_const_drop: Option<QualifResults<'mir, 'tcx, NeedsNonConstDrop>>, } impl<'mir, 'tcx> Qualifs<'mir, 'tcx> { @@ -78,27 +78,25 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> { local: Local, location: Location, ) -> bool { - // FIXME(effects) replace with `NeedsNonconstDrop` after const traits work again - /* let ty = ccx.body.local_decls[local].ty; - if !NeedsDrop::in_any_value_of_ty(ccx, ty) { + // Peeking into opaque types causes cycles if the current function declares said opaque + // type. Thus we avoid short circuiting on the type and instead run the more expensive + // analysis that looks at the actual usage within this function + if !ty.has_opaque_types() && !NeedsNonConstDrop::in_any_value_of_ty(ccx, ty) { return false; } let needs_non_const_drop = self.needs_non_const_drop.get_or_insert_with(|| { let ConstCx { tcx, body, .. } = *ccx; - FlowSensitiveAnalysis::new(NeedsDrop, ccx) - .into_engine(tcx, &body) + FlowSensitiveAnalysis::new(NeedsNonConstDrop, ccx) + .into_engine(tcx, body) .iterate_to_fixpoint() - .into_results_cursor(&body) + .into_results_cursor(body) }); needs_non_const_drop.seek_before_primary_effect(location); needs_non_const_drop.get().contains(local) - */ - - self.needs_drop(ccx, local, location) } /// Returns `true` if `local` is `HasMutInterior` at the given `Location`. @@ -1013,9 +1011,8 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> { let mut err_span = self.span; let ty_of_dropped_place = dropped_place.ty(self.body, self.tcx).ty; - // FIXME(effects) replace with `NeedsNonConstDrop` once we fix const traits let ty_needs_non_const_drop = - qualifs::NeedsDrop::in_any_value_of_ty(self.ccx, ty_of_dropped_place); + qualifs::NeedsNonConstDrop::in_any_value_of_ty(self.ccx, ty_of_dropped_place); debug!(?ty_of_dropped_place, ?ty_needs_non_const_drop); diff --git a/compiler/rustc_const_eval/src/transform/check_consts/post_drop_elaboration.rs b/compiler/rustc_const_eval/src/transform/check_consts/post_drop_elaboration.rs index 06371438ec1..5cd13783c23 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/post_drop_elaboration.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/post_drop_elaboration.rs @@ -5,7 +5,7 @@ use rustc_span::{symbol::sym, Span}; use super::check::Qualifs; use super::ops::{self, NonConstOp}; -use super::qualifs::{NeedsDrop, Qualif}; +use super::qualifs::{NeedsNonConstDrop, Qualif}; use super::ConstCx; /// Returns `true` if we should use the more precise live drop checker that runs after drop @@ -83,8 +83,7 @@ impl<'tcx> Visitor<'tcx> for CheckLiveDrops<'_, 'tcx> { mir::TerminatorKind::Drop { place: dropped_place, .. } => { let dropped_ty = dropped_place.ty(self.body, self.tcx).ty; - // FIXME(effects) use `NeedsNonConstDrop` - if !NeedsDrop::in_any_value_of_ty(self.ccx, dropped_ty) { + if !NeedsNonConstDrop::in_any_value_of_ty(self.ccx, dropped_ty) { // Instead of throwing a bug, we just return here. This is because we have to // run custom `const Drop` impls. return; diff --git a/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs b/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs index de3186a53c1..d5f418e1710 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs @@ -23,8 +23,7 @@ pub fn in_any_value_of_ty<'tcx>( ConstQualifs { has_mut_interior: HasMutInterior::in_any_value_of_ty(cx, ty), needs_drop: NeedsDrop::in_any_value_of_ty(cx, ty), - // FIXME(effects) - needs_non_const_drop: NeedsDrop::in_any_value_of_ty(cx, ty), + needs_non_const_drop: NeedsNonConstDrop::in_any_value_of_ty(cx, ty), custom_eq: CustomEq::in_any_value_of_ty(cx, ty), tainted_by_errors, } @@ -155,12 +154,27 @@ impl Qualif for NeedsNonConstDrop { return false; } - // FIXME(effects) constness + // FIXME(effects): If `destruct` is not a `const_trait`, + // or effects are disabled in this crate, then give up. + let destruct_def_id = cx.tcx.require_lang_item(LangItem::Destruct, Some(cx.body.span)); + if cx.tcx.generics_of(destruct_def_id).host_effect_index.is_none() + || !cx.tcx.features().effects + { + return NeedsDrop::in_any_value_of_ty(cx, ty); + } + let obligation = Obligation::new( cx.tcx, ObligationCause::dummy_with_span(cx.body.span), cx.param_env, - ty::TraitRef::from_lang_item(cx.tcx, LangItem::Destruct, cx.body.span, [ty]), + ty::TraitRef::new( + cx.tcx, + destruct_def_id, + [ + ty::GenericArg::from(ty), + ty::GenericArg::from(cx.tcx.expected_const_effect_param_for_body(cx.def_id())), + ], + ), ); let infcx = cx.tcx.infer_ctxt().build(); diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs index 70252a4dc67..52c3529d2b4 100644 --- a/compiler/rustc_middle/src/ty/util.rs +++ b/compiler/rustc_middle/src/ty/util.rs @@ -781,9 +781,9 @@ impl<'tcx> TyCtxt<'tcx> { } pub fn expected_const_effect_param_for_body(self, def_id: LocalDefId) -> ty::Const<'tcx> { - // if the callee does have the param, we need to equate the param to some const - // value no matter whether the effects feature is enabled in the local crate, - // because inference will fail if we don't. + // FIXME(effects): This is suspicious and should probably not be done, + // especially now that we enforce host effects and then properly handle + // effect vars during fallback. let mut host_always_on = !self.features().effects || self.sess.opts.unstable_opts.unleash_the_miri_inside_of_you; diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs index 5a559bb5fa0..367de517af2 100644 --- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs +++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs @@ -872,9 +872,18 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { ) { // If the predicate is `~const Destruct` in a non-const environment, we don't actually need // to check anything. We'll short-circuit checking any obligations in confirmation, too. - // FIXME(effects) - if true { - candidates.vec.push(ConstDestructCandidate(None)); + let Some(host_effect_index) = + self.tcx().generics_of(obligation.predicate.def_id()).host_effect_index + else { + candidates.vec.push(BuiltinCandidate { has_nested: false }); + return; + }; + // If the obligation has `host = true`, then the obligation is non-const and it's always + // trivially implemented. + if obligation.predicate.skip_binder().trait_ref.args.const_at(host_effect_index) + == self.tcx().consts.true_ + { + candidates.vec.push(BuiltinCandidate { has_nested: false }); return; } diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs index fc4f6f37621..8567f4f0e70 100644 --- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs +++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs @@ -1172,11 +1172,13 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { obligation: &PolyTraitObligation<'tcx>, impl_def_id: Option<DefId>, ) -> Result<Vec<PredicateObligation<'tcx>>, SelectionError<'tcx>> { - // `~const Destruct` in a non-const environment is always trivially true, since our type is `Drop` - // FIXME(effects) - if true { - return Ok(vec![]); - } + let Some(host_effect_index) = + self.tcx().generics_of(obligation.predicate.def_id()).host_effect_index + else { + bug!() + }; + let host_effect_param: ty::GenericArg<'tcx> = + obligation.predicate.skip_binder().trait_ref.args.const_at(host_effect_index).into(); let drop_trait = self.tcx().require_lang_item(LangItem::Drop, None); @@ -1284,7 +1286,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { self.tcx(), LangItem::Destruct, cause.span, - [nested_ty], + [nested_ty.into(), host_effect_param], ), polarity: ty::ImplPolarity::Positive, }), @@ -1310,7 +1312,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { self.tcx(), LangItem::Destruct, cause.span, - [nested_ty], + [nested_ty.into(), host_effect_param], ), polarity: ty::ImplPolarity::Positive, }); |