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Extract compute_bidirectional_outlives_predicates fn

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This commit is contained in:
Santiago Pastorino 2023-06-22 17:40:59 -03:00
parent e69c7306e2
commit 373293c3ca
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GPG Key ID: 8131A24E0C79EFAF
1 changed files with 51 additions and 33 deletions
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84
compiler/rustc_hir_analysis/src/collect/predicates_of.rs
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@ -2,7 +2,7 @@ use crate::astconv::{AstConv, OnlySelfBounds, PredicateFilter};
use crate::bounds::Bounds;
use crate::collect::ItemCtxt;
use crate::constrained_generic_params as cgp;
use hir::{HirId, Node};
use hir::{HirId, Lifetime, Node};
use rustc_data_structures::fx::FxIndexSet;
use rustc_hir as hir;
use rustc_hir::def::DefKind;
@ -10,9 +10,9 @@ use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_hir::intravisit::{self, Visitor};
use rustc_middle::ty::subst::InternalSubsts;
use rustc_middle::ty::{self, Ty, TyCtxt};
use rustc_middle::ty::{GenericPredicates, ToPredicate};
use rustc_middle::ty::{GenericPredicates, Generics, ToPredicate};
use rustc_span::symbol::{sym, Ident};
use rustc_span::{Span, DUMMY_SP};
use rustc_span::{Span, Symbol, DUMMY_SP};
/// Returns a list of all type predicates (explicit and implicit) for the definition with
/// ID `def_id`. This includes all predicates returned by `predicates_defined_on`, plus
@ -289,38 +289,16 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
bug!("unexpected {opaque_ty_node:?}")
};
debug!(?lifetimes);
for (arg, duplicate) in std::iter::zip(lifetimes, ast_generics.params) {
let lifetime_mapping = std::iter::zip(lifetimes, ast_generics.params)
.map(|(arg, dup)| {
let hir::GenericArg::Lifetime(arg) = arg else { bug!() };
let orig_region = icx.astconv().ast_region_to_region(&arg, None);
if !matches!(orig_region.kind(), ty::ReEarlyBound(..)) {
// Only early-bound regions can point to the original generic parameter.
continue;
}
(**arg, dup)
})
.filter(|(_, dup)| matches!(dup.kind, hir::GenericParamKind::Lifetime { .. }))
.map(|(lifetime, dup)| (lifetime, (dup.def_id, dup.name.ident().name, dup.span)));
let hir::GenericParamKind::Lifetime { .. } = duplicate.kind else { continue };
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 = ty::Region::new_early_bound(
tcx,
ty::EarlyBoundRegion {
def_id: dup_def,
index: dup_index,
name: duplicate.name.ident().name,
},
);
predicates.push((
ty::ClauseKind::RegionOutlives(ty::OutlivesPredicate(orig_region, dup_region))
.to_predicate(icx.tcx),
duplicate.span,
));
predicates.push((
ty::ClauseKind::RegionOutlives(ty::OutlivesPredicate(dup_region, orig_region))
.to_predicate(icx.tcx),
duplicate.span,
));
}
bidirectional_lifetime_predicates(tcx, def_id, lifetime_mapping, generics, &mut predicates);
debug!(?predicates);
}
@ -330,6 +308,46 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
}
}
/// Opaques have duplicated lifetimes and we need to compute bidirectional outlives predicates to
/// enforce that these lifetimes stay in sync.
fn compute_bidirectional_outlives_predicates<'tcx>(
tcx: TyCtxt<'tcx>,
item_def_id: LocalDefId,
lifetime_mapping: impl Iterator<Item = (Lifetime, (LocalDefId, Symbol, Span))>,
generics: &Generics,
predicates: &mut Vec<(ty::Clause<'tcx>, Span)>,
) {
let icx = ItemCtxt::new(tcx, item_def_id);
for (arg, (dup_def, name, span)) in lifetime_mapping {
let orig_region = icx.astconv().ast_region_to_region(&arg, None);
if !matches!(orig_region.kind(), ty::ReEarlyBound(..)) {
// There is no late-bound lifetime to actually match up here, since the lifetime doesn't
// show up in the opaque's parent's substs.
continue;
}
let Some(dup_index) = generics.param_def_id_to_index(icx.tcx, dup_def.to_def_id()) else { bug!() };
let dup_region = ty::Region::new_early_bound(
tcx,
ty::EarlyBoundRegion { def_id: dup_def.to_def_id(), index: dup_index, name },
);
predicates.push((
ty::ClauseKind::RegionOutlives(ty::OutlivesPredicate(orig_region, dup_region))
.to_predicate(tcx),
span,
));
predicates.push((
ty::ClauseKind::RegionOutlives(ty::OutlivesPredicate(dup_region, orig_region))
.to_predicate(tcx),
span,
));
}
}
fn const_evaluatable_predicates_of(
tcx: TyCtxt<'_>,
def_id: LocalDefId,