diff options
Diffstat (limited to 'compiler/rustc_hir_typeck/src/generator_interior')
5 files changed, 51 insertions, 27 deletions
diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs index fd8ea1ad7..b3dd3031d 100644 --- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs +++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs @@ -233,6 +233,7 @@ impl<'a, 'tcx> DropRangeVisitor<'a, 'tcx> { self.tcx() .sess .delay_span_bug(expr.span, format!("could not resolve infer vars in `{ty}`")); + return; } let ty = self.tcx().erase_regions(ty); let m = self.tcx().parent_module(expr.hir_id).to_def_id(); @@ -303,8 +304,8 @@ impl<'a, 'tcx> Visitor<'tcx> for DropRangeVisitor<'a, 'tcx> { let mut reinit = None; match expr.kind { ExprKind::Assign(lhs, rhs, _) => { - self.visit_expr(lhs); self.visit_expr(rhs); + self.visit_expr(lhs); reinit = Some(lhs); } @@ -432,7 +433,7 @@ impl<'a, 'tcx> Visitor<'tcx> for DropRangeVisitor<'a, 'tcx> { self.drop_ranges.add_control_edge(self.expr_index, *target) }), - ExprKind::Break(destination, ..) => { + ExprKind::Break(destination, value) => { // destination either points to an expression or to a block. We use // find_target_expression_from_destination to use the last expression of the block // if destination points to a block. @@ -442,7 +443,11 @@ impl<'a, 'tcx> Visitor<'tcx> for DropRangeVisitor<'a, 'tcx> { // will refer to the end of the block due to the post order traversal. self.find_target_expression_from_destination(destination).map_or((), |target| { self.drop_ranges.add_control_edge_hir_id(self.expr_index, target) - }) + }); + + if let Some(value) = value { + self.visit_expr(value); + } } ExprKind::Call(f, args) => { @@ -464,6 +469,12 @@ impl<'a, 'tcx> Visitor<'tcx> for DropRangeVisitor<'a, 'tcx> { ExprKind::AddrOf(..) | ExprKind::Array(..) + // FIXME(eholk): We probably need special handling for AssignOps. The ScopeTree builder + // in region.rs runs both lhs then rhs and rhs then lhs and then sets all yields to be + // the latest they show up in either traversal. With the older scope-based + // approximation, this was fine, but it's probably not right now. What we probably want + // to do instead is still run both orders, but consider anything that showed up as a + // yield in either order. | ExprKind::AssignOp(..) | ExprKind::Binary(..) | ExprKind::Block(..) @@ -501,6 +512,9 @@ impl<'a, 'tcx> Visitor<'tcx> for DropRangeVisitor<'a, 'tcx> { // Increment expr_count here to match what InteriorVisitor expects. self.expr_index = self.expr_index + 1; + + // Save a node mapping to get better CFG visualization + self.drop_ranges.add_node_mapping(pat.hir_id, self.expr_index); } } @@ -520,7 +534,7 @@ impl DropRangesBuilder { } }); } - debug!("hir_id_map: {:?}", tracked_value_map); + debug!("hir_id_map: {:#?}", tracked_value_map); let num_values = tracked_value_map.len(); Self { tracked_value_map, diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_visualize.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_visualize.rs index c0a0bfe8e..e8d31be79 100644 --- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_visualize.rs +++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_visualize.rs @@ -2,6 +2,7 @@ //! flow graph when needed for debugging. use rustc_graphviz as dot; +use rustc_hir::{Expr, ExprKind, Node}; use rustc_middle::ty::TyCtxt; use super::{DropRangesBuilder, PostOrderId}; @@ -80,10 +81,14 @@ impl<'a> dot::Labeller<'a> for DropRangesGraph<'_, '_> { .post_order_map .iter() .find(|(_hir_id, &post_order_id)| post_order_id == *n) - .map_or("<unknown>".into(), |(hir_id, _)| self - .tcx - .hir() - .node_to_string(*hir_id)) + .map_or("<unknown>".into(), |(hir_id, _)| format!( + "{}{}", + self.tcx.hir().node_to_string(*hir_id), + match self.tcx.hir().find(*hir_id) { + Some(Node::Expr(Expr { kind: ExprKind::Yield(..), .. })) => " (yield)", + _ => "", + } + )) ) .into(), ) diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs index 2abcadcc9..f7b493bc2 100644 --- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs +++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs @@ -79,7 +79,7 @@ pub fn compute_drop_ranges<'a, 'tcx>( /// result of `foo`. On the other hand, if `place` points to `x` then `f` will /// be called both on the `ExprKind::Path` node that represents the expression /// as well as the HirId of the local `x` itself. -fn for_each_consumable<'tcx>(hir: Map<'tcx>, place: TrackedValue, mut f: impl FnMut(TrackedValue)) { +fn for_each_consumable(hir: Map<'_>, place: TrackedValue, mut f: impl FnMut(TrackedValue)) { f(place); let node = hir.find(place.hir_id()); if let Some(Node::Expr(expr)) = node { @@ -96,15 +96,13 @@ fn for_each_consumable<'tcx>(hir: Map<'tcx>, place: TrackedValue, mut f: impl Fn } rustc_index::newtype_index! { - pub struct PostOrderId { - DEBUG_FORMAT = "id({})", - } + #[debug_format = "id({})"] + pub struct PostOrderId {} } rustc_index::newtype_index! { - pub struct TrackedValueIndex { - DEBUG_FORMAT = "hidx({})", - } + #[debug_format = "hidx({})"] + pub struct TrackedValueIndex {} } /// Identifies a value whose drop state we need to track. diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs index bfe95852a..ed3d89031 100644 --- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs +++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs @@ -116,7 +116,7 @@ impl<'tcx> ExprUseDelegate<'tcx> { // where the `identity(...)` (the rvalue) produces a return type // of `&'rv mut A`, where `'a: 'rv`. We then assign this result to // `'y`, resulting in (transitively) `'a: 'y` (i.e., while `y` is in use, - // `a` will be considered borrowed). Other parts of the code will ensure + // `a` will be considered borrowed). Other parts of the code will ensure // that if `y` is live over a yield, `&'y mut A` appears in the generator // state. If `'y` is live, then any sound region analysis must conclude // that `'a` is also live. So if this causes a bug, blame some other @@ -140,7 +140,7 @@ impl<'tcx> expr_use_visitor::Delegate<'tcx> for ExprUseDelegate<'tcx> { diag_expr_id: HirId, ) { let hir = self.tcx.hir(); - let parent = match hir.find_parent_node(place_with_id.hir_id) { + let parent = match hir.opt_parent_id(place_with_id.hir_id) { Some(parent) => parent, None => place_with_id.hir_id, }; 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() { |