diff options
Diffstat (limited to 'compiler/rustc_hir_analysis/src/collect/predicates_of.rs')
| -rw-r--r-- | compiler/rustc_hir_analysis/src/collect/predicates_of.rs | 65 |
1 files changed, 56 insertions, 9 deletions
diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs index 46b277d98..2badd66e3 100644 --- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs +++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs @@ -9,8 +9,8 @@ use rustc_hir::def::DefKind; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::intravisit::{self, Visitor}; use rustc_middle::ty::subst::InternalSubsts; -use rustc_middle::ty::ToPredicate; use rustc_middle::ty::{self, Ty, TyCtxt}; +use rustc_middle::ty::{GenericPredicates, ToPredicate}; use rustc_span::symbol::{sym, Ident}; use rustc_span::{Span, DUMMY_SP}; @@ -151,7 +151,8 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP trace!(?generics); // Collect the predicates that were written inline by the user on each - // type parameter (e.g., `<T: Foo>`). + // type parameter (e.g., `<T: Foo>`). Also add `ConstArgHasType` predicates + // for each const parameter. for param in ast_generics.params { match param.kind { // We already dealt with early bound lifetimes above. @@ -175,7 +176,19 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP trace!(?predicates); } GenericParamKind::Const { .. } => { - // Bounds on const parameters are currently not possible. + let name = param.name.ident().name; + let param_const = ty::ParamConst::new(index, name); + + let ct_ty = tcx.type_of(param.def_id.to_def_id()).subst_identity(); + + let ct = tcx.mk_const(param_const, ct_ty); + + let predicate = ty::Binder::dummy(ty::PredicateKind::Clause( + ty::Clause::ConstArgHasType(ct, ct_ty), + )) + .to_predicate(tcx); + predicates.insert((predicate, param.span)); + index += 1; } } @@ -251,7 +264,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP // in trait checking. See `setup_constraining_predicates` // for details. if let Node::Item(&Item { kind: ItemKind::Impl { .. }, .. }) = node { - let self_ty = tcx.type_of(def_id); + let self_ty = tcx.type_of(def_id).subst_identity(); let trait_ref = tcx.impl_trait_ref(def_id).map(ty::EarlyBinder::subst_identity); cgp::setup_constraining_predicates( tcx, @@ -280,15 +293,15 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP } let hir::GenericParamKind::Lifetime { .. } = duplicate.kind else { continue }; - let dup_def = tcx.hir().local_def_id(duplicate.hir_id).to_def_id(); + let dup_def = duplicate.def_id.to_def_id(); let Some(dup_index) = generics.param_def_id_to_index(tcx, dup_def) else { bug!() }; - let dup_region = tcx.mk_region(ty::ReEarlyBound(ty::EarlyBoundRegion { + let dup_region = tcx.mk_re_early_bound(ty::EarlyBoundRegion { def_id: dup_def, index: dup_index, name: duplicate.name.ident().name, - })); + }); predicates.push(( ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::RegionOutlives( ty::OutlivesPredicate(orig_region, dup_region), @@ -439,7 +452,9 @@ pub(super) fn explicit_predicates_of<'tcx>( let hir_id = tcx.hir().local_def_id_to_hir_id(def_id.expect_local()); let parent_def_id = tcx.hir().get_parent_item(hir_id); - if tcx.hir().opt_const_param_default_param_def_id(hir_id).is_some() { + if let Some(defaulted_param_def_id) = + tcx.hir().opt_const_param_default_param_def_id(hir_id) + { // In `generics_of` we set the generics' parent to be our parent's parent which means that // we lose out on the predicates of our actual parent if we dont return those predicates here. // (See comment in `generics_of` for more information on why the parent shenanigans is necessary) @@ -452,7 +467,39 @@ pub(super) fn explicit_predicates_of<'tcx>( // // In the above code we want the anon const to have predicates in its param env for `T: Trait` // and we would be calling `explicit_predicates_of(Foo)` here - return tcx.explicit_predicates_of(parent_def_id); + let parent_preds = tcx.explicit_predicates_of(parent_def_id); + + // If we dont filter out `ConstArgHasType` predicates then every single defaulted const parameter + // will ICE because of #106994. FIXME(generic_const_exprs): remove this when a more general solution + // to #106994 is implemented. + let filtered_predicates = parent_preds + .predicates + .into_iter() + .filter(|(pred, _)| { + if let ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(ct, _)) = + pred.kind().skip_binder() + { + match ct.kind() { + ty::ConstKind::Param(param_const) => { + let defaulted_param_idx = tcx + .generics_of(parent_def_id) + .param_def_id_to_index[&defaulted_param_def_id.to_def_id()]; + param_const.index < defaulted_param_idx + } + _ => bug!( + "`ConstArgHasType` in `predicates_of`\ + that isn't a `Param` const" + ), + } + } else { + true + } + }) + .cloned(); + return GenericPredicates { + parent: parent_preds.parent, + predicates: { tcx.arena.alloc_from_iter(filtered_predicates) }, + }; } let parent_def_kind = tcx.def_kind(parent_def_id); |