From edf95b5d8cd8553740c151c090f49fffec2e7940 Mon Sep 17 00:00:00 2001
From: Vadim Petrochenkov <vadim.petrochenkov@gmail.com>
Date: Mon, 8 May 2023 17:43:20 +0300
Subject: [PATCH] rustc_privacy: Reach underlying types of `impl Trait`s in a
separate pass
outside of fixed point iteration.
---
compiler/rustc_privacy/src/lib.rs | 46 +++++++++++++++++++------------
1 file changed, 29 insertions(+), 17 deletions(-)
diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs
index 5b06c7fbcbb..65dfdf31e54 100644
--- a/compiler/rustc_privacy/src/lib.rs
+++ b/compiler/rustc_privacy/src/lib.rs
@@ -454,6 +454,8 @@ struct EmbargoVisitor<'tcx> {
/// n::p::f()
/// }
macro_reachable: FxHashSet<(LocalDefId, LocalDefId)>,
+ /// Preliminary pass for marking all underlying types of `impl Trait`s as reachable.
+ impl_trait_pass: bool,
/// Has something changed in the level map?
changed: bool,
}
@@ -700,6 +702,20 @@ impl<'tcx> EmbargoVisitor<'tcx> {
impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
+ if self.impl_trait_pass
+ && let hir::ItemKind::OpaqueTy(ref opaque) = item.kind
+ && !opaque.in_trait {
+ // FIXME: This is some serious pessimization intended to workaround deficiencies
+ // in the reachability pass (`middle/reachable.rs`). Types are marked as link-time
+ // reachable if they are returned via `impl Trait`, even from private functions.
+ let pub_ev = EffectiveVisibility::from_vis(ty::Visibility::Public);
+ self.reach_through_impl_trait(item.owner_id.def_id, pub_ev)
+ .generics()
+ .predicates()
+ .ty();
+ return;
+ }
+
// Update levels of nested things and mark all items
// in interfaces of reachable items as reachable.
let item_ev = self.get(item.owner_id.def_id);
@@ -709,28 +725,12 @@ impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
| hir::ItemKind::ExternCrate(..)
| hir::ItemKind::GlobalAsm(..) => {}
// The interface is empty, and all nested items are processed by `visit_item`.
- hir::ItemKind::Mod(..) => {}
+ hir::ItemKind::Mod(..) | hir::ItemKind::OpaqueTy(..) => {}
hir::ItemKind::Macro(ref macro_def, _) => {
if let Some(item_ev) = item_ev {
self.update_reachability_from_macro(item.owner_id.def_id, macro_def, item_ev);
}
}
- hir::ItemKind::OpaqueTy(ref opaque) => {
- // HACK(jynelson): trying to infer the type of `impl trait` breaks `async-std` (and `pub async fn` in general)
- // Since rustdoc never needs to do codegen and doesn't care about link-time reachability,
- // mark this as unreachable.
- // See https://github.com/rust-lang/rust/issues/75100
- if !opaque.in_trait && !self.tcx.sess.opts.actually_rustdoc {
- // FIXME: This is some serious pessimization intended to workaround deficiencies
- // in the reachability pass (`middle/reachable.rs`). Types are marked as link-time
- // reachable if they are returned via `impl Trait`, even from private functions.
- let exist_ev = EffectiveVisibility::from_vis(ty::Visibility::Public);
- self.reach_through_impl_trait(item.owner_id.def_id, exist_ev)
- .generics()
- .predicates()
- .ty();
- }
- }
hir::ItemKind::Const(..)
| hir::ItemKind::Static(..)
| hir::ItemKind::Fn(..)
@@ -2130,10 +2130,22 @@ fn effective_visibilities(tcx: TyCtxt<'_>, (): ()) -> &EffectiveVisibilities {
tcx,
effective_visibilities: tcx.resolutions(()).effective_visibilities.clone(),
macro_reachable: Default::default(),
+ // HACK(jynelson): trying to infer the type of `impl Trait` breaks `async-std` (and
+ // `pub async fn` in general). Since rustdoc never needs to do codegen and doesn't
+ // care about link-time reachability, keep them unreachable (issue #75100).
+ impl_trait_pass: !tcx.sess.opts.actually_rustdoc,
changed: false,
};
visitor.effective_visibilities.check_invariants(tcx, true);
+ if visitor.impl_trait_pass {
+ // Underlying types of `impl Trait`s are marked as reachable unconditionally,
+ // so this pass doesn't need to be a part of the fixed point iteration below.
+ tcx.hir().visit_all_item_likes_in_crate(&mut visitor);
+ visitor.impl_trait_pass = false;
+ visitor.changed = false;
+ }
+
loop {
tcx.hir().visit_all_item_likes_in_crate(&mut visitor);
if visitor.changed {