diff options
Diffstat (limited to 'compiler/rustc_hir_typeck/src/generator_interior/mod.rs')
| -rw-r--r-- | compiler/rustc_hir_typeck/src/generator_interior/mod.rs | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/compiler/rustc_hir_typeck/src/generator_interior/mod.rs b/compiler/rustc_hir_typeck/src/generator_interior/mod.rs index 3b1518ff7..7af526053 100644 --- a/compiler/rustc_hir_typeck/src/generator_interior/mod.rs +++ b/compiler/rustc_hir_typeck/src/generator_interior/mod.rs @@ -71,10 +71,8 @@ impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> { yield_data.expr_and_pat_count, self.expr_count, source_span ); - if self.fcx.sess().opts.unstable_opts.drop_tracking - && self - .drop_ranges - .is_dropped_at(hir_id, yield_data.expr_and_pat_count) + if self + .is_dropped_at_yield_location(hir_id, yield_data.expr_and_pat_count) { debug!("value is dropped at yield point; not recording"); return false; @@ -173,6 +171,18 @@ impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> { } } } + + /// If drop tracking is enabled, consult drop_ranges to see if a value is + /// known to be dropped at a yield point and therefore can be omitted from + /// the generator witness. + fn is_dropped_at_yield_location(&self, value_hir_id: HirId, yield_location: usize) -> bool { + // short-circuit if drop tracking is not enabled. + if !self.fcx.sess().opts.unstable_opts.drop_tracking { + return false; + } + + self.drop_ranges.is_dropped_at(value_hir_id, yield_location) + } } pub fn resolve_interior<'a, 'tcx>( @@ -448,7 +458,7 @@ impl<'a, 'tcx> Visitor<'tcx> for InteriorVisitor<'a, 'tcx> { // the yield, even if it's not borrowed or referenced after the yield. Ideally this would // *only* happen for types with observable drop, not all types which wrap them, but that // doesn't match the behavior of MIR borrowck and causes ICEs. See the FIXME comment in - // src/test/ui/generator/drop-tracking-parent-expression.rs. + // tests/ui/generator/drop-tracking-parent-expression.rs. let scope = if self.drop_ranges.is_borrowed_temporary(expr) || ty.map_or(true, |ty| { // Avoid ICEs in needs_drop. @@ -563,7 +573,7 @@ fn check_must_not_suspend_ty<'tcx>( } ty::Adt(def, _) => check_must_not_suspend_def(fcx.tcx, def.did(), hir_id, data), // FIXME: support adding the attribute to TAITs - ty::Opaque(def, _) => { + ty::Alias(ty::Opaque, ty::AliasTy { def_id: def, .. }) => { let mut has_emitted = false; for &(predicate, _) in fcx.tcx.explicit_item_bounds(def) { // We only look at the `DefId`, so it is safe to skip the binder here. @@ -607,10 +617,7 @@ fn check_must_not_suspend_ty<'tcx>( ty::Tuple(fields) => { let mut has_emitted = false; let comps = match data.expr.map(|e| &e.kind) { - Some(hir::ExprKind::Tup(comps)) => { - debug_assert_eq!(comps.len(), fields.len()); - Some(comps) - } + Some(hir::ExprKind::Tup(comps)) if comps.len() == fields.len() => Some(comps), _ => None, }; for (i, ty) in fields.iter().enumerate() { |