3 use rustc_infer::infer::canonical::Canonical;
4 use rustc_infer::traits::query::NoSolution;
5 use rustc_middle::mir::ConstraintCategory;
6 use rustc_middle::ty::{self, ToPredicate, TypeFoldable};
7 use rustc_span::def_id::DefId;
9 use rustc_trait_selection::traits::query::type_op::{self, TypeOpOutput};
10 use rustc_trait_selection::traits::query::Fallible;
12 use crate::diagnostics::{ToUniverseInfo, UniverseInfo};
14 use super::{Locations, NormalizeLocation, TypeChecker};
16 impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
17 /// Given some operation `op` that manipulates types, proves
18 /// predicates, or otherwise uses the inference context, executes
19 /// `op` and then executes all the further obligations that `op`
20 /// returns. This will yield a set of outlives constraints amongst
21 /// regions which are extracted and stored as having occurred at
24 /// **Any `rustc_infer::infer` operations that might generate region
25 /// constraints should occur within this method so that those
26 /// constraints can be properly localized!**
27 #[instrument(skip(self, op), level = "trace")]
28 pub(super) fn fully_perform_op<R: fmt::Debug, Op>(
31 category: ConstraintCategory<'tcx>,
35 Op: type_op::TypeOp<'tcx, Output = R>,
36 Op::ErrorInfo: ToUniverseInfo<'tcx>,
38 let old_universe = self.infcx.universe();
40 let TypeOpOutput { output, constraints, error_info } = op.fully_perform(self.infcx)?;
42 debug!(?output, ?constraints);
44 if let Some(data) = constraints {
45 self.push_region_constraints(locations, category, data);
48 let universe = self.infcx.universe();
50 if old_universe != universe {
51 let universe_info = match error_info {
52 Some(error_info) => error_info.to_universe_info(old_universe),
53 None => UniverseInfo::other(),
55 for u in (old_universe + 1)..=universe {
56 self.borrowck_context.constraints.universe_causes.insert(u, universe_info.clone());
63 pub(super) fn instantiate_canonical_with_fresh_inference_vars<T>(
66 canonical: &Canonical<'tcx, T>,
69 T: TypeFoldable<'tcx>,
71 let old_universe = self.infcx.universe();
73 let (instantiated, _) =
74 self.infcx.instantiate_canonical_with_fresh_inference_vars(span, canonical);
76 for u in (old_universe + 1)..=self.infcx.universe() {
77 self.borrowck_context.constraints.universe_causes.insert(u, UniverseInfo::other());
83 #[instrument(skip(self), level = "debug")]
84 pub(super) fn prove_trait_ref(
86 trait_ref: ty::TraitRef<'tcx>,
88 category: ConstraintCategory<'tcx>,
91 ty::Binder::dummy(ty::PredicateKind::Trait(ty::TraitPredicate {
93 constness: ty::BoundConstness::NotConst,
94 polarity: ty::ImplPolarity::Positive,
101 #[instrument(level = "debug", skip(self))]
102 pub(super) fn normalize_and_prove_instantiated_predicates(
104 // Keep this parameter for now, in case we start using
105 // it in `ConstraintCategory` at some point.
107 instantiated_predicates: ty::InstantiatedPredicates<'tcx>,
108 locations: Locations,
110 for (predicate, span) in instantiated_predicates
113 .zip(instantiated_predicates.spans.into_iter())
116 let category = ConstraintCategory::Predicate(span);
117 let predicate = self.normalize_with_category(predicate, locations, category);
118 self.prove_predicate(predicate, locations, category);
122 pub(super) fn prove_predicates(
124 predicates: impl IntoIterator<
125 Item = impl ToPredicate<'tcx, ty::Predicate<'tcx>> + std::fmt::Debug,
127 locations: Locations,
128 category: ConstraintCategory<'tcx>,
130 for predicate in predicates {
131 self.prove_predicate(predicate, locations, category);
135 #[instrument(skip(self), level = "debug")]
136 pub(super) fn prove_predicate(
138 predicate: impl ToPredicate<'tcx, ty::Predicate<'tcx>> + std::fmt::Debug,
139 locations: Locations,
140 category: ConstraintCategory<'tcx>,
142 let param_env = self.param_env;
143 let predicate = predicate.to_predicate(self.tcx());
144 self.fully_perform_op(
147 param_env.and(type_op::prove_predicate::ProvePredicate::new(predicate)),
149 .unwrap_or_else(|NoSolution| {
150 span_mirbug!(self, NoSolution, "could not prove {:?}", predicate);
154 pub(super) fn normalize<T>(&mut self, value: T, location: impl NormalizeLocation) -> T
156 T: type_op::normalize::Normalizable<'tcx> + fmt::Display + Copy + 'tcx,
158 self.normalize_with_category(value, location, ConstraintCategory::Boring)
161 #[instrument(skip(self), level = "debug")]
162 pub(super) fn normalize_with_category<T>(
165 location: impl NormalizeLocation,
166 category: ConstraintCategory<'tcx>,
169 T: type_op::normalize::Normalizable<'tcx> + fmt::Display + Copy + 'tcx,
171 let param_env = self.param_env;
172 self.fully_perform_op(
173 location.to_locations(),
175 param_env.and(type_op::normalize::Normalize::new(value)),
177 .unwrap_or_else(|NoSolution| {
178 span_mirbug!(self, NoSolution, "failed to normalize `{:?}`", value);