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Auto merge of #89648 - nbdd0121:issue-89606, r=nikomatsakis

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Ignore type of projections for upvar capturing

Fix #89606

Ignore type of projections for upvar capturing. Originally HashMap is used, and the hash/eq implementation of Place takes the type of projections into account. These types may differ by lifetime which causes #89606 to ICE.

I originally considered erasing regions but `place.ty()` is used when creating upvar tuple type, more than just serving as a key type, so I switched to a linear comparison with custom eq (`compare_place_ignore_ty`) instead.

r? `@wesleywiser`

`@rustbot` label +T-compiler
This commit is contained in:
bors 2021-10-11 21:39:11 +00:00
commit 7cc8c44871
2 changed files with 49 additions and 6 deletions
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15
compiler/rustc_typeck/src/check/upvar.rs
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@ -65,6 +65,7 @@ use std::iter;
enum PlaceAncestryRelation {
Ancestor,
Descendant,
SamePlace,
Divergent,
}
@ -564,7 +565,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
for possible_ancestor in min_cap_list.iter_mut() {
match determine_place_ancestry_relation(&place, &possible_ancestor.place) {
// current place is descendant of possible_ancestor
PlaceAncestryRelation::Descendant => {
PlaceAncestryRelation::Descendant | PlaceAncestryRelation::SamePlace => {
ancestor_found = true;
let backup_path_expr_id = possible_ancestor.info.path_expr_id;
@ -2278,15 +2279,17 @@ fn determine_place_ancestry_relation(
let projections_b = &place_b.projections;
let same_initial_projections =
iter::zip(projections_a, projections_b).all(|(proj_a, proj_b)| proj_a == proj_b);
iter::zip(projections_a, projections_b).all(|(proj_a, proj_b)| proj_a.kind == proj_b.kind);
if same_initial_projections {
use std::cmp::Ordering;
// First min(n, m) projections are the same
// Select Ancestor/Descendant
if projections_b.len() >= projections_a.len() {
PlaceAncestryRelation::Ancestor
} else {
PlaceAncestryRelation::Descendant
match projections_b.len().cmp(&projections_a.len()) {
Ordering::Greater => PlaceAncestryRelation::Ancestor,
Ordering::Equal => PlaceAncestryRelation::SamePlace,
Ordering::Less => PlaceAncestryRelation::Descendant,
}
} else {
PlaceAncestryRelation::Divergent