Address goal nits

This commit is contained in:
Michael Goulet 2023-01-20 18:38:33 +00:00
parent d6a411c086
commit 444cbcd729
4 changed files with 54 additions and 38 deletions

View File

@ -1,7 +1,7 @@
//! Code shared by trait and projection goals for candidate assembly.
use super::infcx_ext::InferCtxtExt;
use super::{CanonicalResponse, Certainty, EvalCtxt, Goal, MaybeCause, QueryResult};
use super::{CanonicalResponse, Certainty, EvalCtxt, Goal, QueryResult};
use rustc_hir::def_id::DefId;
use rustc_infer::traits::query::NoSolution;
use rustc_infer::traits::util::elaborate_predicates;
@ -148,9 +148,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
if goal.predicate.self_ty().is_ty_var() {
return vec![Candidate {
source: CandidateSource::BuiltinImpl,
result: self
.make_canonical_response(Certainty::Maybe(MaybeCause::Ambiguity))
.unwrap(),
result: self.make_canonical_response(Certainty::AMBIGUOUS).unwrap(),
}];
}

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@ -19,6 +19,7 @@
use std::mem;
use rustc_hir::def_id::DefId;
use rustc_infer::infer::canonical::{Canonical, CanonicalVarKind, CanonicalVarValues};
use rustc_infer::infer::canonical::{OriginalQueryValues, QueryRegionConstraints, QueryResponse};
use rustc_infer::infer::{InferCtxt, InferOk, TyCtxtInferExt};
@ -27,7 +28,7 @@ use rustc_infer::traits::Obligation;
use rustc_middle::infer::canonical::Certainty as OldCertainty;
use rustc_middle::ty::{self, Ty, TyCtxt};
use rustc_middle::ty::{
RegionOutlivesPredicate, SubtypePredicate, ToPredicate, TypeOutlivesPredicate,
CoercePredicate, RegionOutlivesPredicate, SubtypePredicate, ToPredicate, TypeOutlivesPredicate,
};
use rustc_span::DUMMY_SP;
@ -89,6 +90,8 @@ pub enum Certainty {
}
impl Certainty {
pub const AMBIGUOUS: Certainty = Certainty::Maybe(MaybeCause::Ambiguity);
/// When proving multiple goals using **AND**, e.g. nested obligations for an impl,
/// use this function to unify the certainty of these goals
pub fn unify_and(self, other: Certainty) -> Certainty {
@ -248,21 +251,15 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
ty::PredicateKind::Subtype(predicate) => {
self.compute_subtype_goal(Goal { param_env, predicate })
}
ty::PredicateKind::Coerce(predicate) => self.compute_subtype_goal(Goal {
param_env,
predicate: SubtypePredicate {
a_is_expected: true,
a: predicate.a,
b: predicate.b,
},
}),
ty::PredicateKind::ClosureKind(_, substs, kind) => self.compute_closure_kind_goal(
substs.as_closure().kind_ty().to_opt_closure_kind(),
kind,
),
ty::PredicateKind::Ambiguous => {
self.make_canonical_response(Certainty::Maybe(MaybeCause::Ambiguity))
ty::PredicateKind::Coerce(predicate) => {
self.compute_coerce_goal(Goal { param_env, predicate })
}
ty::PredicateKind::ClosureKind(def_id, substs, kind) => self
.compute_closure_kind_goal(Goal {
param_env,
predicate: (def_id, substs, kind),
}),
ty::PredicateKind::Ambiguous => self.make_canonical_response(Certainty::AMBIGUOUS),
// FIXME: implement these predicates :)
ty::PredicateKind::WellFormed(_)
| ty::PredicateKind::ObjectSafe(_)
@ -296,10 +293,29 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
self.make_canonical_response(Certainty::Yes)
}
fn compute_coerce_goal(
&mut self,
goal: Goal<'tcx, CoercePredicate<'tcx>>,
) -> QueryResult<'tcx> {
self.compute_subtype_goal(Goal {
param_env: goal.param_env,
predicate: SubtypePredicate {
a_is_expected: false,
a: goal.predicate.a,
b: goal.predicate.b,
},
})
}
fn compute_subtype_goal(
&mut self,
goal: Goal<'tcx, SubtypePredicate<'tcx>>,
) -> QueryResult<'tcx> {
if goal.predicate.a.is_ty_var() && goal.predicate.b.is_ty_var() {
// FIXME: Do we want to register a subtype relation between these vars?
// That won't actually reflect in the query response, so it seems moot.
self.make_canonical_response(Certainty::AMBIGUOUS)
} else {
self.infcx.probe(|_| {
let InferOk { value: (), obligations } = self
.infcx
@ -310,14 +326,17 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
)
})
}
}
fn compute_closure_kind_goal(
&mut self,
found_kind: Option<ty::ClosureKind>,
expected_kind: ty::ClosureKind,
goal: Goal<'tcx, (DefId, ty::SubstsRef<'tcx>, ty::ClosureKind)>,
) -> QueryResult<'tcx> {
let (_, substs, expected_kind) = goal.predicate;
let found_kind = substs.as_closure().kind_ty().to_opt_closure_kind();
let Some(found_kind) = found_kind else {
return self.make_canonical_response(Certainty::Maybe(MaybeCause::Ambiguity));
return self.make_canonical_response(Certainty::AMBIGUOUS);
};
if found_kind.extends(expected_kind) {
self.make_canonical_response(Certainty::Yes)

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@ -3,7 +3,7 @@ use crate::traits::{specialization_graph, translate_substs};
use super::assembly::{self, Candidate, CandidateSource};
use super::infcx_ext::InferCtxtExt;
use super::trait_goals::structural_traits;
use super::{Certainty, EvalCtxt, Goal, MaybeCause, QueryResult};
use super::{Certainty, EvalCtxt, Goal, QueryResult};
use rustc_errors::ErrorGuaranteed;
use rustc_hir::def::DefKind;
use rustc_hir::def_id::DefId;
@ -229,8 +229,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
goal.predicate.def_id(),
impl_def_id
)? else {
let certainty = Certainty::Maybe(MaybeCause::Ambiguity);
return ecx.make_canonical_response(trait_ref_certainty.unify_and(certainty));
return ecx.make_canonical_response(trait_ref_certainty.unify_and(Certainty::AMBIGUOUS));
};
if !assoc_def.item.defaultness(tcx).has_value() {
@ -382,7 +381,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
.to_predicate(ecx.tcx());
Self::consider_assumption(ecx, goal, pred)
} else {
ecx.make_canonical_response(Certainty::Maybe(MaybeCause::Ambiguity))
ecx.make_canonical_response(Certainty::AMBIGUOUS)
}
}

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@ -4,7 +4,7 @@ use std::iter;
use super::assembly::{self, Candidate, CandidateSource};
use super::infcx_ext::InferCtxtExt;
use super::{Certainty, EvalCtxt, Goal, MaybeCause, QueryResult};
use super::{Certainty, EvalCtxt, Goal, QueryResult};
use rustc_hir::def_id::DefId;
use rustc_infer::infer::InferCtxt;
use rustc_infer::traits::query::NoSolution;
@ -133,7 +133,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
goal: Goal<'tcx, Self>,
) -> QueryResult<'tcx> {
if goal.predicate.self_ty().has_non_region_infer() {
return ecx.make_canonical_response(Certainty::Maybe(MaybeCause::Ambiguity));
return ecx.make_canonical_response(Certainty::AMBIGUOUS);
}
let tcx = ecx.tcx();
@ -171,7 +171,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
.to_predicate(ecx.tcx());
Self::consider_assumption(ecx, goal, pred)
} else {
ecx.make_canonical_response(Certainty::Maybe(MaybeCause::Ambiguity))
ecx.make_canonical_response(Certainty::AMBIGUOUS)
}
}