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Prepopulate opaques in canonical input

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This commit is contained in:
Michael Goulet
2023-05-16 23:51:23 +00:00
parent a2d7ffc635
commit f3c9c21658
11 changed files with 243 additions and 81 deletions
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29
compiler/rustc_trait_selection/src/solve/project_goals.rs
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@@ -22,24 +22,25 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
&mut self,
goal: Goal<'tcx, ProjectionPredicate<'tcx>>,
) -> QueryResult<'tcx> {
// To only compute normalization once for each projection we only
// normalize if the expected term is an unconstrained inference variable.
//
// E.g. for `<T as Trait>::Assoc == u32` we recursively compute the goal
// `exists<U> <T as Trait>::Assoc == U` and then take the resulting type for
// `U` and equate it with `u32`. This means that we don't need a separate
// projection cache in the solver.
if self.term_is_fully_unconstrained(goal) {
match goal.predicate.projection_ty.kind(self.tcx()) {
ty::AliasKind::Projection => {
match goal.predicate.projection_ty.kind(self.tcx()) {
ty::AliasKind::Projection => {
// To only compute normalization once for each projection we only
// normalize if the expected term is an unconstrained inference variable.
//
// E.g. for `<T as Trait>::Assoc == u32` we recursively compute the goal
// `exists<U> <T as Trait>::Assoc == U` and then take the resulting type for
// `U` and equate it with `u32`. This means that we don't need a separate
// projection cache in the solver.
if self.term_is_fully_unconstrained(goal) {
let candidates = self.assemble_and_evaluate_candidates(goal);
self.merge_candidates(candidates)
} else {
self.set_normalizes_to_hack_goal(goal);
self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
}
ty::AliasKind::Opaque => self.normalize_opaque_type(goal),
}
} else {
self.set_normalizes_to_hack_goal(goal);
self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
ty::AliasKind::Opaque => self.normalize_opaque_type(goal),
ty::AliasKind::Inherent => bug!("IATs not supported here yet"),
}
}
}