1 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
2 #![feature(in_band_lifetimes)]
4 #![feature(or_patterns)]
5 #![cfg_attr(bootstrap, feature(track_caller))]
6 #![recursion_limit = "256"]
8 use rustc_attr as attr;
9 use rustc_data_structures::fx::FxHashSet;
10 use rustc_errors::struct_span_err;
12 use rustc_hir::def::{DefKind, Res};
13 use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
14 use rustc_hir::intravisit::{self, DeepVisitor, NestedVisitorMap, Visitor};
15 use rustc_hir::{AssocItemKind, HirIdSet, Node, PatKind};
16 use rustc_middle::bug;
17 use rustc_middle::hir::map::Map;
18 use rustc_middle::middle::privacy::{AccessLevel, AccessLevels};
19 use rustc_middle::ty::fold::TypeVisitor;
20 use rustc_middle::ty::query::Providers;
21 use rustc_middle::ty::subst::InternalSubsts;
22 use rustc_middle::ty::{self, GenericParamDefKind, TraitRef, Ty, TyCtxt, TypeFoldable};
23 use rustc_session::lint;
24 use rustc_span::hygiene::Transparency;
25 use rustc_span::symbol::{kw, sym, Ident};
28 use std::marker::PhantomData;
29 use std::{cmp, fmt, mem};
31 ////////////////////////////////////////////////////////////////////////////////
32 /// Generic infrastructure used to implement specific visitors below.
33 ////////////////////////////////////////////////////////////////////////////////
35 /// Implemented to visit all `DefId`s in a type.
36 /// Visiting `DefId`s is useful because visibilities and reachabilities are attached to them.
37 /// The idea is to visit "all components of a type", as documented in
38 /// https://github.com/rust-lang/rfcs/blob/master/text/2145-type-privacy.md#how-to-determine-visibility-of-a-type.
39 /// The default type visitor (`TypeVisitor`) does most of the job, but it has some shortcomings.
40 /// First, it doesn't have overridable `fn visit_trait_ref`, so we have to catch trait `DefId`s
41 /// manually. Second, it doesn't visit some type components like signatures of fn types, or traits
42 /// in `impl Trait`, see individual comments in `DefIdVisitorSkeleton::visit_ty`.
43 trait DefIdVisitor<'tcx> {
44 fn tcx(&self) -> TyCtxt<'tcx>;
45 fn shallow(&self) -> bool {
48 fn skip_assoc_tys(&self) -> bool {
51 fn visit_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool;
53 /// Not overridden, but used to actually visit types and traits.
54 fn skeleton(&mut self) -> DefIdVisitorSkeleton<'_, 'tcx, Self> {
55 DefIdVisitorSkeleton {
57 visited_opaque_tys: Default::default(),
58 dummy: Default::default(),
61 fn visit(&mut self, ty_fragment: impl TypeFoldable<'tcx>) -> bool {
62 ty_fragment.visit_with(&mut self.skeleton())
64 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> bool {
65 self.skeleton().visit_trait(trait_ref)
67 fn visit_predicates(&mut self, predicates: ty::GenericPredicates<'tcx>) -> bool {
68 self.skeleton().visit_predicates(predicates)
72 struct DefIdVisitorSkeleton<'v, 'tcx, V>
74 V: DefIdVisitor<'tcx> + ?Sized,
76 def_id_visitor: &'v mut V,
77 visited_opaque_tys: FxHashSet<DefId>,
78 dummy: PhantomData<TyCtxt<'tcx>>,
81 impl<'tcx, V> DefIdVisitorSkeleton<'_, 'tcx, V>
83 V: DefIdVisitor<'tcx> + ?Sized,
85 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> bool {
86 let TraitRef { def_id, substs } = trait_ref;
87 self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref.print_only_trait_path())
88 || (!self.def_id_visitor.shallow() && substs.visit_with(self))
91 fn visit_predicates(&mut self, predicates: ty::GenericPredicates<'tcx>) -> bool {
92 let ty::GenericPredicates { parent: _, predicates } = predicates;
93 for (predicate, _span) in predicates {
94 match predicate.kind() {
95 ty::PredicateKind::Trait(poly_predicate, _) => {
96 let ty::TraitPredicate { trait_ref } = poly_predicate.skip_binder();
97 if self.visit_trait(trait_ref) {
101 ty::PredicateKind::Projection(poly_predicate) => {
102 let ty::ProjectionPredicate { projection_ty, ty } =
103 poly_predicate.skip_binder();
104 if ty.visit_with(self) {
107 if self.visit_trait(projection_ty.trait_ref(self.def_id_visitor.tcx())) {
111 ty::PredicateKind::TypeOutlives(poly_predicate) => {
112 let ty::OutlivesPredicate(ty, _region) = poly_predicate.skip_binder();
113 if ty.visit_with(self) {
117 ty::PredicateKind::RegionOutlives(..) => {}
118 _ => bug!("unexpected predicate: {:?}", predicate),
125 impl<'tcx, V> TypeVisitor<'tcx> for DefIdVisitorSkeleton<'_, 'tcx, V>
127 V: DefIdVisitor<'tcx> + ?Sized,
129 fn visit_ty(&mut self, ty: Ty<'tcx>) -> bool {
130 let tcx = self.def_id_visitor.tcx();
131 // InternalSubsts are not visited here because they are visited below in `super_visit_with`.
133 ty::Adt(&ty::AdtDef { did: def_id, .. }, ..)
134 | ty::Foreign(def_id)
135 | ty::FnDef(def_id, ..)
136 | ty::Closure(def_id, ..)
137 | ty::Generator(def_id, ..) => {
138 if self.def_id_visitor.visit_def_id(def_id, "type", &ty) {
141 if self.def_id_visitor.shallow() {
144 // Default type visitor doesn't visit signatures of fn types.
145 // Something like `fn() -> Priv {my_func}` is considered a private type even if
146 // `my_func` is public, so we need to visit signatures.
147 if let ty::FnDef(..) = ty.kind {
148 if tcx.fn_sig(def_id).visit_with(self) {
152 // Inherent static methods don't have self type in substs.
153 // Something like `fn() {my_method}` type of the method
154 // `impl Pub<Priv> { pub fn my_method() {} }` is considered a private type,
155 // so we need to visit the self type additionally.
156 if let Some(assoc_item) = tcx.opt_associated_item(def_id) {
157 if let ty::ImplContainer(impl_def_id) = assoc_item.container {
158 if tcx.type_of(impl_def_id).visit_with(self) {
164 ty::Projection(proj) => {
165 if self.def_id_visitor.skip_assoc_tys() {
166 // Visitors searching for minimal visibility/reachability want to
167 // conservatively approximate associated types like `<Type as Trait>::Alias`
168 // as visible/reachable even if both `Type` and `Trait` are private.
169 // Ideally, associated types should be substituted in the same way as
170 // free type aliases, but this isn't done yet.
173 // This will also visit substs if necessary, so we don't need to recurse.
174 return self.visit_trait(proj.trait_ref(tcx));
176 ty::Dynamic(predicates, ..) => {
177 // All traits in the list are considered the "primary" part of the type
178 // and are visited by shallow visitors.
179 for predicate in predicates.skip_binder() {
180 let trait_ref = match predicate {
181 ty::ExistentialPredicate::Trait(trait_ref) => trait_ref,
182 ty::ExistentialPredicate::Projection(proj) => proj.trait_ref(tcx),
183 ty::ExistentialPredicate::AutoTrait(def_id) => {
184 ty::ExistentialTraitRef { def_id, substs: InternalSubsts::empty() }
187 let ty::ExistentialTraitRef { def_id, substs: _ } = trait_ref;
188 if self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref) {
193 ty::Opaque(def_id, ..) => {
194 // Skip repeated `Opaque`s to avoid infinite recursion.
195 if self.visited_opaque_tys.insert(def_id) {
196 // The intent is to treat `impl Trait1 + Trait2` identically to
197 // `dyn Trait1 + Trait2`. Therefore we ignore def-id of the opaque type itself
198 // (it either has no visibility, or its visibility is insignificant, like
199 // visibilities of type aliases) and recurse into predicates instead to go
200 // through the trait list (default type visitor doesn't visit those traits).
201 // All traits in the list are considered the "primary" part of the type
202 // and are visited by shallow visitors.
203 if self.visit_predicates(tcx.predicates_of(def_id)) {
208 // These types don't have their own def-ids (but may have subcomponents
209 // with def-ids that should be visited recursively).
225 | ty::GeneratorWitness(..) => {}
226 ty::Bound(..) | ty::Placeholder(..) | ty::Infer(..) => {
227 bug!("unexpected type: {:?}", ty)
231 !self.def_id_visitor.shallow() && ty.super_visit_with(self)
235 fn def_id_visibility<'tcx>(
238 ) -> (ty::Visibility, Span, &'static str) {
239 match def_id.as_local().map(|def_id| tcx.hir().as_local_hir_id(def_id)) {
241 let vis = match tcx.hir().get(hir_id) {
242 Node::Item(item) => &item.vis,
243 Node::ForeignItem(foreign_item) => &foreign_item.vis,
244 Node::MacroDef(macro_def) => {
245 if attr::contains_name(¯o_def.attrs, sym::macro_export) {
246 return (ty::Visibility::Public, macro_def.span, "public");
251 Node::TraitItem(..) | Node::Variant(..) => {
252 return def_id_visibility(tcx, tcx.hir().get_parent_did(hir_id).to_def_id());
254 Node::ImplItem(impl_item) => {
255 match tcx.hir().get(tcx.hir().get_parent_item(hir_id)) {
256 Node::Item(item) => match &item.kind {
257 hir::ItemKind::Impl { of_trait: None, .. } => &impl_item.vis,
258 hir::ItemKind::Impl { of_trait: Some(trait_ref), .. } => {
259 return def_id_visibility(tcx, trait_ref.path.res.def_id());
261 kind => bug!("unexpected item kind: {:?}", kind),
263 node => bug!("unexpected node kind: {:?}", node),
266 Node::Ctor(vdata) => {
267 let parent_hir_id = tcx.hir().get_parent_node(hir_id);
268 match tcx.hir().get(parent_hir_id) {
269 Node::Variant(..) => {
270 let parent_did = tcx.hir().local_def_id(parent_hir_id);
271 let (mut ctor_vis, mut span, mut descr) =
272 def_id_visibility(tcx, parent_did.to_def_id());
274 let adt_def = tcx.adt_def(tcx.hir().get_parent_did(hir_id).to_def_id());
275 let ctor_did = tcx.hir().local_def_id(vdata.ctor_hir_id().unwrap());
276 let variant = adt_def.variant_with_ctor_id(ctor_did.to_def_id());
278 if variant.is_field_list_non_exhaustive()
279 && ctor_vis == ty::Visibility::Public
282 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
283 let attrs = tcx.get_attrs(variant.def_id);
285 attr::find_by_name(&attrs, sym::non_exhaustive).unwrap().span;
286 descr = "crate-visible";
289 return (ctor_vis, span, descr);
292 let item = match tcx.hir().get(parent_hir_id) {
293 Node::Item(item) => item,
294 node => bug!("unexpected node kind: {:?}", node),
296 let (mut ctor_vis, mut span, mut descr) = (
297 ty::Visibility::from_hir(&item.vis, parent_hir_id, tcx),
299 item.vis.node.descr(),
301 for field in vdata.fields() {
302 let field_vis = ty::Visibility::from_hir(&field.vis, hir_id, tcx);
303 if ctor_vis.is_at_least(field_vis, tcx) {
304 ctor_vis = field_vis;
305 span = field.vis.span;
306 descr = field.vis.node.descr();
310 // If the structure is marked as non_exhaustive then lower the
311 // visibility to within the crate.
312 if ctor_vis == ty::Visibility::Public {
314 tcx.adt_def(tcx.hir().get_parent_did(hir_id).to_def_id());
315 if adt_def.non_enum_variant().is_field_list_non_exhaustive() {
317 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
318 span = attr::find_by_name(&item.attrs, sym::non_exhaustive)
321 descr = "crate-visible";
325 return (ctor_vis, span, descr);
327 node => bug!("unexpected node kind: {:?}", node),
330 Node::Expr(expr) => {
332 ty::Visibility::Restricted(tcx.parent_module(expr.hir_id).to_def_id()),
337 node => bug!("unexpected node kind: {:?}", node),
339 (ty::Visibility::from_hir(vis, hir_id, tcx), vis.span, vis.node.descr())
342 let vis = tcx.visibility(def_id);
343 let descr = if vis == ty::Visibility::Public { "public" } else { "private" };
344 (vis, tcx.def_span(def_id), descr)
349 fn min(vis1: ty::Visibility, vis2: ty::Visibility, tcx: TyCtxt<'_>) -> ty::Visibility {
350 if vis1.is_at_least(vis2, tcx) { vis2 } else { vis1 }
353 ////////////////////////////////////////////////////////////////////////////////
354 /// Visitor used to determine if pub(restricted) is used anywhere in the crate.
356 /// This is done so that `private_in_public` warnings can be turned into hard errors
357 /// in crates that have been updated to use pub(restricted).
358 ////////////////////////////////////////////////////////////////////////////////
359 struct PubRestrictedVisitor<'tcx> {
361 has_pub_restricted: bool,
364 impl Visitor<'tcx> for PubRestrictedVisitor<'tcx> {
365 type Map = Map<'tcx>;
367 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
368 NestedVisitorMap::All(self.tcx.hir())
370 fn visit_vis(&mut self, vis: &'tcx hir::Visibility<'tcx>) {
371 self.has_pub_restricted = self.has_pub_restricted || vis.node.is_pub_restricted();
375 ////////////////////////////////////////////////////////////////////////////////
376 /// Visitor used to determine impl visibility and reachability.
377 ////////////////////////////////////////////////////////////////////////////////
379 struct FindMin<'a, 'tcx, VL: VisibilityLike> {
381 access_levels: &'a AccessLevels,
385 impl<'a, 'tcx, VL: VisibilityLike> DefIdVisitor<'tcx> for FindMin<'a, 'tcx, VL> {
386 fn tcx(&self) -> TyCtxt<'tcx> {
389 fn shallow(&self) -> bool {
392 fn skip_assoc_tys(&self) -> bool {
395 fn visit_def_id(&mut self, def_id: DefId, _kind: &str, _descr: &dyn fmt::Display) -> bool {
396 self.min = VL::new_min(self, def_id);
401 trait VisibilityLike: Sized {
403 const SHALLOW: bool = false;
404 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self;
406 // Returns an over-approximation (`skip_assoc_tys` = true) of visibility due to
407 // associated types for which we can't determine visibility precisely.
408 fn of_impl(hir_id: hir::HirId, tcx: TyCtxt<'_>, access_levels: &AccessLevels) -> Self {
409 let mut find = FindMin { tcx, access_levels, min: Self::MAX };
410 let def_id = tcx.hir().local_def_id(hir_id);
411 find.visit(tcx.type_of(def_id));
412 if let Some(trait_ref) = tcx.impl_trait_ref(def_id) {
413 find.visit_trait(trait_ref);
418 impl VisibilityLike for ty::Visibility {
419 const MAX: Self = ty::Visibility::Public;
420 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
421 min(def_id_visibility(find.tcx, def_id).0, find.min, find.tcx)
424 impl VisibilityLike for Option<AccessLevel> {
425 const MAX: Self = Some(AccessLevel::Public);
426 // Type inference is very smart sometimes.
427 // It can make an impl reachable even some components of its type or trait are unreachable.
428 // E.g. methods of `impl ReachableTrait<UnreachableTy> for ReachableTy<UnreachableTy> { ... }`
429 // can be usable from other crates (#57264). So we skip substs when calculating reachability
430 // and consider an impl reachable if its "shallow" type and trait are reachable.
432 // The assumption we make here is that type-inference won't let you use an impl without knowing
433 // both "shallow" version of its self type and "shallow" version of its trait if it exists
434 // (which require reaching the `DefId`s in them).
435 const SHALLOW: bool = true;
436 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
438 if let Some(def_id) = def_id.as_local() {
439 let hir_id = find.tcx.hir().as_local_hir_id(def_id);
440 find.access_levels.map.get(&hir_id).cloned()
449 ////////////////////////////////////////////////////////////////////////////////
450 /// The embargo visitor, used to determine the exports of the AST.
451 ////////////////////////////////////////////////////////////////////////////////
453 struct EmbargoVisitor<'tcx> {
456 /// Accessibility levels for reachable nodes.
457 access_levels: AccessLevels,
458 /// A set of pairs corresponding to modules, where the first module is
459 /// reachable via a macro that's defined in the second module. This cannot
460 /// be represented as reachable because it can't handle the following case:
462 /// pub mod n { // Should be `Public`
463 /// pub(crate) mod p { // Should *not* be accessible
464 /// pub fn f() -> i32 { 12 } // Must be `Reachable`
470 macro_reachable: FxHashSet<(hir::HirId, DefId)>,
471 /// Previous accessibility level; `None` means unreachable.
472 prev_level: Option<AccessLevel>,
473 /// Has something changed in the level map?
477 struct ReachEverythingInTheInterfaceVisitor<'a, 'tcx> {
478 access_level: Option<AccessLevel>,
480 ev: &'a mut EmbargoVisitor<'tcx>,
483 impl EmbargoVisitor<'tcx> {
484 fn get(&self, id: hir::HirId) -> Option<AccessLevel> {
485 self.access_levels.map.get(&id).cloned()
488 /// Updates node level and returns the updated level.
489 fn update(&mut self, id: hir::HirId, level: Option<AccessLevel>) -> Option<AccessLevel> {
490 let old_level = self.get(id);
491 // Accessibility levels can only grow.
492 if level > old_level {
493 self.access_levels.map.insert(id, level.unwrap());
504 access_level: Option<AccessLevel>,
505 ) -> ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
506 ReachEverythingInTheInterfaceVisitor {
507 access_level: cmp::min(access_level, Some(AccessLevel::Reachable)),
508 item_def_id: self.tcx.hir().local_def_id(item_id).to_def_id(),
513 /// Updates the item as being reachable through a macro defined in the given
514 /// module. Returns `true` if the level has changed.
515 fn update_macro_reachable(&mut self, reachable_mod: hir::HirId, defining_mod: DefId) -> bool {
516 if self.macro_reachable.insert((reachable_mod, defining_mod)) {
517 self.update_macro_reachable_mod(reachable_mod, defining_mod);
524 fn update_macro_reachable_mod(&mut self, reachable_mod: hir::HirId, defining_mod: DefId) {
525 let module_def_id = self.tcx.hir().local_def_id(reachable_mod);
526 let module = self.tcx.hir().get_module(module_def_id).0;
527 for item_id in module.item_ids {
528 let hir_id = item_id.id;
529 let item_def_id = self.tcx.hir().local_def_id(hir_id);
530 let def_kind = self.tcx.def_kind(item_def_id);
531 let item = self.tcx.hir().expect_item(hir_id);
532 let vis = ty::Visibility::from_hir(&item.vis, hir_id, self.tcx);
533 self.update_macro_reachable_def(hir_id, def_kind, vis, defining_mod);
535 if let Some(exports) = self.tcx.module_exports(module_def_id) {
536 for export in exports {
537 if export.vis.is_accessible_from(defining_mod, self.tcx) {
538 if let Res::Def(def_kind, def_id) = export.res {
539 let vis = def_id_visibility(self.tcx, def_id).0;
540 if let Some(def_id) = def_id.as_local() {
541 let hir_id = self.tcx.hir().as_local_hir_id(def_id);
542 self.update_macro_reachable_def(hir_id, def_kind, vis, defining_mod);
550 fn update_macro_reachable_def(
557 let level = Some(AccessLevel::Reachable);
558 if let ty::Visibility::Public = vis {
559 self.update(hir_id, level);
562 // No type privacy, so can be directly marked as reachable.
566 | DefKind::TraitAlias
567 | DefKind::TyAlias => {
568 if vis.is_accessible_from(module, self.tcx) {
569 self.update(hir_id, level);
573 // We can't use a module name as the final segment of a path, except
574 // in use statements. Since re-export checking doesn't consider
575 // hygiene these don't need to be marked reachable. The contents of
576 // the module, however may be reachable.
578 if vis.is_accessible_from(module, self.tcx) {
579 self.update_macro_reachable(hir_id, module);
583 DefKind::Struct | DefKind::Union => {
584 // While structs and unions have type privacy, their fields do
586 if let ty::Visibility::Public = vis {
587 let item = self.tcx.hir().expect_item(hir_id);
588 if let hir::ItemKind::Struct(ref struct_def, _)
589 | hir::ItemKind::Union(ref struct_def, _) = item.kind
591 for field in struct_def.fields() {
593 ty::Visibility::from_hir(&field.vis, field.hir_id, self.tcx);
594 if field_vis.is_accessible_from(module, self.tcx) {
595 self.reach(field.hir_id, level).ty();
599 bug!("item {:?} with DefKind {:?}", item, def_kind);
604 // These have type privacy, so are not reachable unless they're
605 // public, or are not namespaced at all.
608 | DefKind::ConstParam
609 | DefKind::Ctor(_, _)
618 | DefKind::LifetimeParam
619 | DefKind::ExternCrate
621 | DefKind::ForeignMod
627 | DefKind::Generator => (),
631 /// Given the path segments of a `ItemKind::Use`, then we need
632 /// to update the visibility of the intermediate use so that it isn't linted
633 /// by `unreachable_pub`.
635 /// This isn't trivial as `path.res` has the `DefId` of the eventual target
636 /// of the use statement not of the next intermediate use statement.
638 /// To do this, consider the last two segments of the path to our intermediate
639 /// use statement. We expect the penultimate segment to be a module and the
640 /// last segment to be the name of the item we are exporting. We can then
641 /// look at the items contained in the module for the use statement with that
642 /// name and update that item's visibility.
644 /// FIXME: This solution won't work with glob imports and doesn't respect
645 /// namespaces. See <https://github.com/rust-lang/rust/pull/57922#discussion_r251234202>.
646 fn update_visibility_of_intermediate_use_statements(
648 segments: &[hir::PathSegment<'_>],
650 if let Some([module, segment]) = segments.rchunks_exact(2).next() {
651 if let Some(item) = module
653 .and_then(|res| res.mod_def_id())
654 // If the module is `self`, i.e. the current crate,
655 // there will be no corresponding item.
656 .filter(|def_id| def_id.index != CRATE_DEF_INDEX || def_id.krate != LOCAL_CRATE)
658 def_id.as_local().map(|def_id| self.tcx.hir().as_local_hir_id(def_id))
660 .map(|module_hir_id| self.tcx.hir().expect_item(module_hir_id))
662 if let hir::ItemKind::Mod(m) = &item.kind {
663 for item_id in m.item_ids {
664 let item = self.tcx.hir().expect_item(item_id.id);
665 let def_id = self.tcx.hir().local_def_id(item_id.id);
666 if !self.tcx.hygienic_eq(segment.ident, item.ident, def_id.to_def_id()) {
669 if let hir::ItemKind::Use(..) = item.kind {
670 self.update(item.hir_id, Some(AccessLevel::Exported));
679 impl Visitor<'tcx> for EmbargoVisitor<'tcx> {
680 type Map = Map<'tcx>;
682 /// We want to visit items in the context of their containing
683 /// module and so forth, so supply a crate for doing a deep walk.
684 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
685 NestedVisitorMap::All(self.tcx.hir())
688 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
689 let inherited_item_level = match item.kind {
690 hir::ItemKind::Impl { .. } => {
691 Option::<AccessLevel>::of_impl(item.hir_id, self.tcx, &self.access_levels)
693 // Foreign modules inherit level from parents.
694 hir::ItemKind::ForeignMod(..) => self.prev_level,
695 // Other `pub` items inherit levels from parents.
696 hir::ItemKind::Const(..)
697 | hir::ItemKind::Enum(..)
698 | hir::ItemKind::ExternCrate(..)
699 | hir::ItemKind::GlobalAsm(..)
700 | hir::ItemKind::Fn(..)
701 | hir::ItemKind::Mod(..)
702 | hir::ItemKind::Static(..)
703 | hir::ItemKind::Struct(..)
704 | hir::ItemKind::Trait(..)
705 | hir::ItemKind::TraitAlias(..)
706 | hir::ItemKind::OpaqueTy(..)
707 | hir::ItemKind::TyAlias(..)
708 | hir::ItemKind::Union(..)
709 | hir::ItemKind::Use(..) => {
710 if item.vis.node.is_pub() {
718 // Update level of the item itself.
719 let item_level = self.update(item.hir_id, inherited_item_level);
721 // Update levels of nested things.
723 hir::ItemKind::Enum(ref def, _) => {
724 for variant in def.variants {
725 let variant_level = self.update(variant.id, item_level);
726 if let Some(ctor_hir_id) = variant.data.ctor_hir_id() {
727 self.update(ctor_hir_id, item_level);
729 for field in variant.data.fields() {
730 self.update(field.hir_id, variant_level);
734 hir::ItemKind::Impl { ref of_trait, items, .. } => {
735 for impl_item_ref in items {
736 if of_trait.is_some() || impl_item_ref.vis.node.is_pub() {
737 self.update(impl_item_ref.id.hir_id, item_level);
741 hir::ItemKind::Trait(.., trait_item_refs) => {
742 for trait_item_ref in trait_item_refs {
743 self.update(trait_item_ref.id.hir_id, item_level);
746 hir::ItemKind::Struct(ref def, _) | hir::ItemKind::Union(ref def, _) => {
747 if let Some(ctor_hir_id) = def.ctor_hir_id() {
748 self.update(ctor_hir_id, item_level);
750 for field in def.fields() {
751 if field.vis.node.is_pub() {
752 self.update(field.hir_id, item_level);
756 hir::ItemKind::ForeignMod(ref foreign_mod) => {
757 for foreign_item in foreign_mod.items {
758 if foreign_item.vis.node.is_pub() {
759 self.update(foreign_item.hir_id, item_level);
763 hir::ItemKind::OpaqueTy(..)
764 | hir::ItemKind::Use(..)
765 | hir::ItemKind::Static(..)
766 | hir::ItemKind::Const(..)
767 | hir::ItemKind::GlobalAsm(..)
768 | hir::ItemKind::TyAlias(..)
769 | hir::ItemKind::Mod(..)
770 | hir::ItemKind::TraitAlias(..)
771 | hir::ItemKind::Fn(..)
772 | hir::ItemKind::ExternCrate(..) => {}
775 // Mark all items in interfaces of reachable items as reachable.
777 // The interface is empty.
778 hir::ItemKind::ExternCrate(..) => {}
779 // All nested items are checked by `visit_item`.
780 hir::ItemKind::Mod(..) => {}
781 // Re-exports are handled in `visit_mod`. However, in order to avoid looping over
782 // all of the items of a mod in `visit_mod` looking for use statements, we handle
783 // making sure that intermediate use statements have their visibilities updated here.
784 hir::ItemKind::Use(ref path, _) => {
785 if item_level.is_some() {
786 self.update_visibility_of_intermediate_use_statements(path.segments.as_ref());
789 // The interface is empty.
790 hir::ItemKind::GlobalAsm(..) => {}
791 hir::ItemKind::OpaqueTy(..) => {
792 // FIXME: This is some serious pessimization intended to workaround deficiencies
793 // in the reachability pass (`middle/reachable.rs`). Types are marked as link-time
794 // reachable if they are returned via `impl Trait`, even from private functions.
795 let exist_level = cmp::max(item_level, Some(AccessLevel::ReachableFromImplTrait));
796 self.reach(item.hir_id, exist_level).generics().predicates().ty();
799 hir::ItemKind::Const(..)
800 | hir::ItemKind::Static(..)
801 | hir::ItemKind::Fn(..)
802 | hir::ItemKind::TyAlias(..) => {
803 if item_level.is_some() {
804 self.reach(item.hir_id, item_level).generics().predicates().ty();
807 hir::ItemKind::Trait(.., trait_item_refs) => {
808 if item_level.is_some() {
809 self.reach(item.hir_id, item_level).generics().predicates();
811 for trait_item_ref in trait_item_refs {
812 let mut reach = self.reach(trait_item_ref.id.hir_id, item_level);
813 reach.generics().predicates();
815 if trait_item_ref.kind == AssocItemKind::Type
816 && !trait_item_ref.defaultness.has_value()
825 hir::ItemKind::TraitAlias(..) => {
826 if item_level.is_some() {
827 self.reach(item.hir_id, item_level).generics().predicates();
830 // Visit everything except for private impl items.
831 hir::ItemKind::Impl { items, .. } => {
832 if item_level.is_some() {
833 self.reach(item.hir_id, item_level).generics().predicates().ty().trait_ref();
835 for impl_item_ref in items {
836 let impl_item_level = self.get(impl_item_ref.id.hir_id);
837 if impl_item_level.is_some() {
838 self.reach(impl_item_ref.id.hir_id, impl_item_level)
847 // Visit everything, but enum variants have their own levels.
848 hir::ItemKind::Enum(ref def, _) => {
849 if item_level.is_some() {
850 self.reach(item.hir_id, item_level).generics().predicates();
852 for variant in def.variants {
853 let variant_level = self.get(variant.id);
854 if variant_level.is_some() {
855 for field in variant.data.fields() {
856 self.reach(field.hir_id, variant_level).ty();
858 // Corner case: if the variant is reachable, but its
859 // enum is not, make the enum reachable as well.
860 self.update(item.hir_id, variant_level);
864 // Visit everything, but foreign items have their own levels.
865 hir::ItemKind::ForeignMod(ref foreign_mod) => {
866 for foreign_item in foreign_mod.items {
867 let foreign_item_level = self.get(foreign_item.hir_id);
868 if foreign_item_level.is_some() {
869 self.reach(foreign_item.hir_id, foreign_item_level)
876 // Visit everything except for private fields.
877 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
878 if item_level.is_some() {
879 self.reach(item.hir_id, item_level).generics().predicates();
880 for field in struct_def.fields() {
881 let field_level = self.get(field.hir_id);
882 if field_level.is_some() {
883 self.reach(field.hir_id, field_level).ty();
890 let orig_level = mem::replace(&mut self.prev_level, item_level);
891 intravisit::walk_item(self, item);
892 self.prev_level = orig_level;
895 fn visit_block(&mut self, b: &'tcx hir::Block<'tcx>) {
896 // Blocks can have public items, for example impls, but they always
897 // start as completely private regardless of publicity of a function,
898 // constant, type, field, etc., in which this block resides.
899 let orig_level = mem::replace(&mut self.prev_level, None);
900 intravisit::walk_block(self, b);
901 self.prev_level = orig_level;
904 fn visit_mod(&mut self, m: &'tcx hir::Mod<'tcx>, _sp: Span, id: hir::HirId) {
905 // This code is here instead of in visit_item so that the
906 // crate module gets processed as well.
907 if self.prev_level.is_some() {
908 let def_id = self.tcx.hir().local_def_id(id);
909 if let Some(exports) = self.tcx.module_exports(def_id) {
910 for export in exports.iter() {
911 if export.vis == ty::Visibility::Public {
912 if let Some(def_id) = export.res.opt_def_id() {
913 if let Some(def_id) = def_id.as_local() {
914 let hir_id = self.tcx.hir().as_local_hir_id(def_id);
915 self.update(hir_id, Some(AccessLevel::Exported));
923 intravisit::walk_mod(self, m, id);
926 fn visit_macro_def(&mut self, md: &'tcx hir::MacroDef<'tcx>) {
927 if attr::find_transparency(&md.attrs, md.ast.macro_rules).0 != Transparency::Opaque {
928 self.update(md.hir_id, Some(AccessLevel::Public));
932 let macro_module_def_id =
933 ty::DefIdTree::parent(self.tcx, self.tcx.hir().local_def_id(md.hir_id).to_def_id())
935 // FIXME(#71104) Should really be using just `as_local_hir_id` but
936 // some `DefId` do not seem to have a corresponding HirId.
937 let hir_id = macro_module_def_id
939 .and_then(|def_id| self.tcx.hir().opt_local_def_id_to_hir_id(def_id));
940 let mut module_id = match hir_id {
941 Some(module_id) if self.tcx.hir().is_hir_id_module(module_id) => module_id,
942 // `module_id` doesn't correspond to a `mod`, return early (#63164, #65252).
945 let level = if md.vis.node.is_pub() { self.get(module_id) } else { None };
946 let new_level = self.update(md.hir_id, level);
947 if new_level.is_none() {
952 let changed_reachability = self.update_macro_reachable(module_id, macro_module_def_id);
953 if changed_reachability || module_id == hir::CRATE_HIR_ID {
956 module_id = self.tcx.hir().get_parent_node(module_id);
961 impl ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
962 fn generics(&mut self) -> &mut Self {
963 for param in &self.ev.tcx.generics_of(self.item_def_id).params {
965 GenericParamDefKind::Lifetime => {}
966 GenericParamDefKind::Type { has_default, .. } => {
968 self.visit(self.ev.tcx.type_of(param.def_id));
971 GenericParamDefKind::Const => {
972 self.visit(self.ev.tcx.type_of(param.def_id));
979 fn predicates(&mut self) -> &mut Self {
980 self.visit_predicates(self.ev.tcx.predicates_of(self.item_def_id));
984 fn ty(&mut self) -> &mut Self {
985 self.visit(self.ev.tcx.type_of(self.item_def_id));
989 fn trait_ref(&mut self) -> &mut Self {
990 if let Some(trait_ref) = self.ev.tcx.impl_trait_ref(self.item_def_id) {
991 self.visit_trait(trait_ref);
997 impl DefIdVisitor<'tcx> for ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
998 fn tcx(&self) -> TyCtxt<'tcx> {
1001 fn visit_def_id(&mut self, def_id: DefId, _kind: &str, _descr: &dyn fmt::Display) -> bool {
1002 if let Some(def_id) = def_id.as_local() {
1003 let hir_id = self.ev.tcx.hir().as_local_hir_id(def_id);
1004 if let ((ty::Visibility::Public, ..), _)
1005 | (_, Some(AccessLevel::ReachableFromImplTrait)) =
1006 (def_id_visibility(self.tcx(), def_id.to_def_id()), self.access_level)
1008 self.ev.update(hir_id, self.access_level);
1015 //////////////////////////////////////////////////////////////////////////////////////
1016 /// Name privacy visitor, checks privacy and reports violations.
1017 /// Most of name privacy checks are performed during the main resolution phase,
1018 /// or later in type checking when field accesses and associated items are resolved.
1019 /// This pass performs remaining checks for fields in struct expressions and patterns.
1020 //////////////////////////////////////////////////////////////////////////////////////
1022 struct NamePrivacyVisitor<'tcx> {
1024 maybe_typeck_tables: Option<&'tcx ty::TypeckTables<'tcx>>,
1025 current_item: Option<hir::HirId>,
1028 impl<'tcx> NamePrivacyVisitor<'tcx> {
1029 /// Gets the type-checking side-tables for the current body.
1030 /// As this will ICE if called outside bodies, only call when working with
1031 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
1033 fn tables(&self) -> &'tcx ty::TypeckTables<'tcx> {
1034 self.maybe_typeck_tables.expect("`NamePrivacyVisitor::tables` called outside of body")
1037 // Checks that a field in a struct constructor (expression or pattern) is accessible.
1040 use_ctxt: Span, // syntax context of the field name at the use site
1041 span: Span, // span of the field pattern, e.g., `x: 0`
1042 def: &'tcx ty::AdtDef, // definition of the struct or enum
1043 field: &'tcx ty::FieldDef,
1044 in_update_syntax: bool,
1046 // definition of the field
1047 let ident = Ident::new(kw::Invalid, use_ctxt);
1048 let current_hir = self.current_item.unwrap();
1049 let def_id = self.tcx.adjust_ident_and_get_scope(ident, def.did, current_hir).1;
1050 if !def.is_enum() && !field.vis.is_accessible_from(def_id, self.tcx) {
1051 let label = if in_update_syntax {
1052 format!("field `{}` is private", field.ident)
1054 "private field".to_string()
1061 "field `{}` of {} `{}` is private",
1063 def.variant_descr(),
1064 self.tcx.def_path_str(def.did)
1066 .span_label(span, label)
1072 impl<'tcx> Visitor<'tcx> for NamePrivacyVisitor<'tcx> {
1073 type Map = Map<'tcx>;
1075 /// We want to visit items in the context of their containing
1076 /// module and so forth, so supply a crate for doing a deep walk.
1077 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1078 NestedVisitorMap::All(self.tcx.hir())
1081 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
1082 // Don't visit nested modules, since we run a separate visitor walk
1083 // for each module in `privacy_access_levels`
1086 fn visit_nested_body(&mut self, body: hir::BodyId) {
1087 let old_maybe_typeck_tables = self.maybe_typeck_tables.replace(self.tcx.body_tables(body));
1088 let body = self.tcx.hir().body(body);
1089 self.visit_body(body);
1090 self.maybe_typeck_tables = old_maybe_typeck_tables;
1093 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1094 let orig_current_item = self.current_item.replace(item.hir_id);
1095 intravisit::walk_item(self, item);
1096 self.current_item = orig_current_item;
1099 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
1100 if let hir::ExprKind::Struct(ref qpath, fields, ref base) = expr.kind {
1101 let res = self.tables().qpath_res(qpath, expr.hir_id);
1102 let adt = self.tables().expr_ty(expr).ty_adt_def().unwrap();
1103 let variant = adt.variant_of_res(res);
1104 if let Some(ref base) = *base {
1105 // If the expression uses FRU we need to make sure all the unmentioned fields
1106 // are checked for privacy (RFC 736). Rather than computing the set of
1107 // unmentioned fields, just check them all.
1108 for (vf_index, variant_field) in variant.fields.iter().enumerate() {
1111 .find(|f| self.tcx.field_index(f.hir_id, self.tables()) == vf_index);
1112 let (use_ctxt, span) = match field {
1113 Some(field) => (field.ident.span, field.span),
1114 None => (base.span, base.span),
1116 self.check_field(use_ctxt, span, adt, variant_field, true);
1119 for field in fields {
1120 let use_ctxt = field.ident.span;
1121 let index = self.tcx.field_index(field.hir_id, self.tables());
1122 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1127 intravisit::walk_expr(self, expr);
1130 fn visit_pat(&mut self, pat: &'tcx hir::Pat<'tcx>) {
1131 if let PatKind::Struct(ref qpath, fields, _) = pat.kind {
1132 let res = self.tables().qpath_res(qpath, pat.hir_id);
1133 let adt = self.tables().pat_ty(pat).ty_adt_def().unwrap();
1134 let variant = adt.variant_of_res(res);
1135 for field in fields {
1136 let use_ctxt = field.ident.span;
1137 let index = self.tcx.field_index(field.hir_id, self.tables());
1138 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1142 intravisit::walk_pat(self, pat);
1146 ////////////////////////////////////////////////////////////////////////////////////////////
1147 /// Type privacy visitor, checks types for privacy and reports violations.
1148 /// Both explicitly written types and inferred types of expressions and patters are checked.
1149 /// Checks are performed on "semantic" types regardless of names and their hygiene.
1150 ////////////////////////////////////////////////////////////////////////////////////////////
1152 struct TypePrivacyVisitor<'tcx> {
1154 maybe_typeck_tables: Option<&'tcx ty::TypeckTables<'tcx>>,
1155 current_item: LocalDefId,
1159 impl<'tcx> TypePrivacyVisitor<'tcx> {
1160 /// Gets the type-checking side-tables for the current body.
1161 /// As this will ICE if called outside bodies, only call when working with
1162 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
1164 fn tables(&self) -> &'tcx ty::TypeckTables<'tcx> {
1165 self.maybe_typeck_tables.expect("`TypePrivacyVisitor::tables` called outside of body")
1168 fn item_is_accessible(&self, did: DefId) -> bool {
1169 def_id_visibility(self.tcx, did)
1171 .is_accessible_from(self.current_item.to_def_id(), self.tcx)
1174 // Take node-id of an expression or pattern and check its type for privacy.
1175 fn check_expr_pat_type(&mut self, id: hir::HirId, span: Span) -> bool {
1177 let tables = self.tables();
1178 if self.visit(tables.node_type(id)) || self.visit(tables.node_substs(id)) {
1181 if let Some(adjustments) = tables.adjustments().get(id) {
1182 for adjustment in adjustments {
1183 if self.visit(adjustment.target) {
1191 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1192 let is_error = !self.item_is_accessible(def_id);
1196 .struct_span_err(self.span, &format!("{} `{}` is private", kind, descr))
1197 .span_label(self.span, &format!("private {}", kind))
1204 impl<'tcx> Visitor<'tcx> for TypePrivacyVisitor<'tcx> {
1205 type Map = Map<'tcx>;
1207 /// We want to visit items in the context of their containing
1208 /// module and so forth, so supply a crate for doing a deep walk.
1209 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1210 NestedVisitorMap::All(self.tcx.hir())
1213 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
1214 // Don't visit nested modules, since we run a separate visitor walk
1215 // for each module in `privacy_access_levels`
1218 fn visit_nested_body(&mut self, body: hir::BodyId) {
1219 let old_maybe_typeck_tables = self.maybe_typeck_tables.replace(self.tcx.body_tables(body));
1220 let body = self.tcx.hir().body(body);
1221 self.visit_body(body);
1222 self.maybe_typeck_tables = old_maybe_typeck_tables;
1225 fn visit_ty(&mut self, hir_ty: &'tcx hir::Ty<'tcx>) {
1226 self.span = hir_ty.span;
1227 if let Some(tables) = self.maybe_typeck_tables {
1229 if self.visit(tables.node_type(hir_ty.hir_id)) {
1233 // Types in signatures.
1234 // FIXME: This is very ineffective. Ideally each HIR type should be converted
1235 // into a semantic type only once and the result should be cached somehow.
1236 if self.visit(rustc_typeck::hir_ty_to_ty(self.tcx, hir_ty)) {
1241 intravisit::walk_ty(self, hir_ty);
1244 fn visit_trait_ref(&mut self, trait_ref: &'tcx hir::TraitRef<'tcx>) {
1245 self.span = trait_ref.path.span;
1246 if self.maybe_typeck_tables.is_none() {
1247 // Avoid calling `hir_trait_to_predicates` in bodies, it will ICE.
1248 // The traits' privacy in bodies is already checked as a part of trait object types.
1249 let bounds = rustc_typeck::hir_trait_to_predicates(
1252 // NOTE: This isn't really right, but the actual type doesn't matter here. It's
1253 // just required by `ty::TraitRef`.
1254 self.tcx.types.never,
1257 for (trait_predicate, _, _) in bounds.trait_bounds {
1258 if self.visit_trait(trait_predicate.skip_binder()) {
1263 for (poly_predicate, _) in bounds.projection_bounds {
1265 if self.visit(poly_predicate.skip_binder().ty)
1266 || self.visit_trait(poly_predicate.skip_binder().projection_ty.trait_ref(tcx))
1273 intravisit::walk_trait_ref(self, trait_ref);
1276 // Check types of expressions
1277 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
1278 if self.check_expr_pat_type(expr.hir_id, expr.span) {
1279 // Do not check nested expressions if the error already happened.
1283 hir::ExprKind::Assign(_, ref rhs, _) | hir::ExprKind::Match(ref rhs, ..) => {
1284 // Do not report duplicate errors for `x = y` and `match x { ... }`.
1285 if self.check_expr_pat_type(rhs.hir_id, rhs.span) {
1289 hir::ExprKind::MethodCall(_, span, _, _) => {
1290 // Method calls have to be checked specially.
1292 if let Some(def_id) = self.tables().type_dependent_def_id(expr.hir_id) {
1293 if self.visit(self.tcx.type_of(def_id)) {
1299 .delay_span_bug(expr.span, "no type-dependent def for method call");
1305 intravisit::walk_expr(self, expr);
1308 // Prohibit access to associated items with insufficient nominal visibility.
1310 // Additionally, until better reachability analysis for macros 2.0 is available,
1311 // we prohibit access to private statics from other crates, this allows to give
1312 // more code internal visibility at link time. (Access to private functions
1313 // is already prohibited by type privacy for function types.)
1314 fn visit_qpath(&mut self, qpath: &'tcx hir::QPath<'tcx>, id: hir::HirId, span: Span) {
1315 let def = match qpath {
1316 hir::QPath::Resolved(_, path) => match path.res {
1317 Res::Def(kind, def_id) => Some((kind, def_id)),
1320 hir::QPath::TypeRelative(..) => {
1321 self.maybe_typeck_tables.and_then(|tables| tables.type_dependent_def(id))
1324 let def = def.filter(|(kind, _)| match kind {
1325 DefKind::AssocFn | DefKind::AssocConst | DefKind::AssocTy | DefKind::Static => true,
1328 if let Some((kind, def_id)) = def {
1329 let is_local_static =
1330 if let DefKind::Static = kind { def_id.is_local() } else { false };
1331 if !self.item_is_accessible(def_id) && !is_local_static {
1332 let sess = self.tcx.sess;
1333 let sm = sess.source_map();
1334 let name = match qpath {
1335 hir::QPath::Resolved(_, path) => sm.span_to_snippet(path.span).ok(),
1336 hir::QPath::TypeRelative(_, segment) => Some(segment.ident.to_string()),
1338 let kind = kind.descr(def_id);
1339 let msg = match name {
1340 Some(name) => format!("{} `{}` is private", kind, name),
1341 None => format!("{} is private", kind),
1343 sess.struct_span_err(span, &msg)
1344 .span_label(span, &format!("private {}", kind))
1350 intravisit::walk_qpath(self, qpath, id, span);
1353 // Check types of patterns.
1354 fn visit_pat(&mut self, pattern: &'tcx hir::Pat<'tcx>) {
1355 if self.check_expr_pat_type(pattern.hir_id, pattern.span) {
1356 // Do not check nested patterns if the error already happened.
1360 intravisit::walk_pat(self, pattern);
1363 fn visit_local(&mut self, local: &'tcx hir::Local<'tcx>) {
1364 if let Some(ref init) = local.init {
1365 if self.check_expr_pat_type(init.hir_id, init.span) {
1366 // Do not report duplicate errors for `let x = y`.
1371 intravisit::walk_local(self, local);
1374 // Check types in item interfaces.
1375 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1376 let orig_current_item =
1377 mem::replace(&mut self.current_item, self.tcx.hir().local_def_id(item.hir_id));
1378 let old_maybe_typeck_tables = self.maybe_typeck_tables.take();
1379 intravisit::walk_item(self, item);
1380 self.maybe_typeck_tables = old_maybe_typeck_tables;
1381 self.current_item = orig_current_item;
1385 impl DefIdVisitor<'tcx> for TypePrivacyVisitor<'tcx> {
1386 fn tcx(&self) -> TyCtxt<'tcx> {
1389 fn visit_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1390 self.check_def_id(def_id, kind, descr)
1394 ///////////////////////////////////////////////////////////////////////////////
1395 /// Obsolete visitors for checking for private items in public interfaces.
1396 /// These visitors are supposed to be kept in frozen state and produce an
1397 /// "old error node set". For backward compatibility the new visitor reports
1398 /// warnings instead of hard errors when the erroneous node is not in this old set.
1399 ///////////////////////////////////////////////////////////////////////////////
1401 struct ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1403 access_levels: &'a AccessLevels,
1405 // Set of errors produced by this obsolete visitor.
1406 old_error_set: HirIdSet,
1409 struct ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1410 inner: &'a ObsoleteVisiblePrivateTypesVisitor<'b, 'tcx>,
1411 /// Whether the type refers to private types.
1412 contains_private: bool,
1413 /// Whether we've recurred at all (i.e., if we're pointing at the
1414 /// first type on which `visit_ty` was called).
1415 at_outer_type: bool,
1416 /// Whether that first type is a public path.
1417 outer_type_is_public_path: bool,
1420 impl<'a, 'tcx> ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1421 fn path_is_private_type(&self, path: &hir::Path<'_>) -> bool {
1422 let did = match path.res {
1423 Res::PrimTy(..) | Res::SelfTy(..) | Res::Err => return false,
1424 res => res.def_id(),
1427 // A path can only be private if:
1428 // it's in this crate...
1429 if let Some(did) = did.as_local() {
1430 // .. and it corresponds to a private type in the AST (this returns
1431 // `None` for type parameters).
1432 match self.tcx.hir().find(self.tcx.hir().as_local_hir_id(did)) {
1433 Some(Node::Item(ref item)) => !item.vis.node.is_pub(),
1434 Some(_) | None => false,
1441 fn trait_is_public(&self, trait_id: hir::HirId) -> bool {
1442 // FIXME: this would preferably be using `exported_items`, but all
1443 // traits are exported currently (see `EmbargoVisitor.exported_trait`).
1444 self.access_levels.is_public(trait_id)
1447 fn check_generic_bound(&mut self, bound: &hir::GenericBound<'_>) {
1448 if let hir::GenericBound::Trait(ref trait_ref, _) = *bound {
1449 if self.path_is_private_type(&trait_ref.trait_ref.path) {
1450 self.old_error_set.insert(trait_ref.trait_ref.hir_ref_id);
1455 fn item_is_public(&self, id: &hir::HirId, vis: &hir::Visibility<'_>) -> bool {
1456 self.access_levels.is_reachable(*id) || vis.node.is_pub()
1460 impl<'a, 'b, 'tcx, 'v> Visitor<'v> for ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1461 type Map = intravisit::ErasedMap<'v>;
1463 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1464 NestedVisitorMap::None
1467 fn visit_ty(&mut self, ty: &hir::Ty<'_>) {
1468 if let hir::TyKind::Path(hir::QPath::Resolved(_, ref path)) = ty.kind {
1469 if self.inner.path_is_private_type(path) {
1470 self.contains_private = true;
1471 // Found what we're looking for, so let's stop working.
1475 if let hir::TyKind::Path(_) = ty.kind {
1476 if self.at_outer_type {
1477 self.outer_type_is_public_path = true;
1480 self.at_outer_type = false;
1481 intravisit::walk_ty(self, ty)
1484 // Don't want to recurse into `[, .. expr]`.
1485 fn visit_expr(&mut self, _: &hir::Expr<'_>) {}
1488 impl<'a, 'tcx> Visitor<'tcx> for ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1489 type Map = Map<'tcx>;
1491 /// We want to visit items in the context of their containing
1492 /// module and so forth, so supply a crate for doing a deep walk.
1493 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1494 NestedVisitorMap::All(self.tcx.hir())
1497 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1499 // Contents of a private mod can be re-exported, so we need
1500 // to check internals.
1501 hir::ItemKind::Mod(_) => {}
1503 // An `extern {}` doesn't introduce a new privacy
1504 // namespace (the contents have their own privacies).
1505 hir::ItemKind::ForeignMod(_) => {}
1507 hir::ItemKind::Trait(.., ref bounds, _) => {
1508 if !self.trait_is_public(item.hir_id) {
1512 for bound in bounds.iter() {
1513 self.check_generic_bound(bound)
1517 // Impls need some special handling to try to offer useful
1518 // error messages without (too many) false positives
1519 // (i.e., we could just return here to not check them at
1520 // all, or some worse estimation of whether an impl is
1521 // publicly visible).
1522 hir::ItemKind::Impl { generics: ref g, ref of_trait, ref self_ty, items, .. } => {
1523 // `impl [... for] Private` is never visible.
1524 let self_contains_private;
1525 // `impl [... for] Public<...>`, but not `impl [... for]
1526 // Vec<Public>` or `(Public,)`, etc.
1527 let self_is_public_path;
1529 // Check the properties of the `Self` type:
1531 let mut visitor = ObsoleteCheckTypeForPrivatenessVisitor {
1533 contains_private: false,
1534 at_outer_type: true,
1535 outer_type_is_public_path: false,
1537 visitor.visit_ty(&self_ty);
1538 self_contains_private = visitor.contains_private;
1539 self_is_public_path = visitor.outer_type_is_public_path;
1542 // Miscellaneous info about the impl:
1544 // `true` iff this is `impl Private for ...`.
1545 let not_private_trait = of_trait.as_ref().map_or(
1546 true, // no trait counts as public trait
1548 let did = tr.path.res.def_id();
1550 if let Some(did) = did.as_local() {
1551 self.trait_is_public(self.tcx.hir().as_local_hir_id(did))
1553 true // external traits must be public
1558 // `true` iff this is a trait impl or at least one method is public.
1560 // `impl Public { $( fn ...() {} )* }` is not visible.
1562 // This is required over just using the methods' privacy
1563 // directly because we might have `impl<T: Foo<Private>> ...`,
1564 // and we shouldn't warn about the generics if all the methods
1565 // are private (because `T` won't be visible externally).
1566 let trait_or_some_public_method = of_trait.is_some()
1567 || items.iter().any(|impl_item_ref| {
1568 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1569 match impl_item.kind {
1570 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..) => {
1571 self.access_levels.is_reachable(impl_item_ref.id.hir_id)
1573 hir::ImplItemKind::TyAlias(_) => false,
1577 if !self_contains_private && not_private_trait && trait_or_some_public_method {
1578 intravisit::walk_generics(self, g);
1582 for impl_item_ref in items {
1583 // This is where we choose whether to walk down
1584 // further into the impl to check its items. We
1585 // should only walk into public items so that we
1586 // don't erroneously report errors for private
1587 // types in private items.
1588 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1589 match impl_item.kind {
1590 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..)
1592 .item_is_public(&impl_item.hir_id, &impl_item.vis) =>
1594 intravisit::walk_impl_item(self, impl_item)
1596 hir::ImplItemKind::TyAlias(..) => {
1597 intravisit::walk_impl_item(self, impl_item)
1604 // Any private types in a trait impl fall into three
1606 // 1. mentioned in the trait definition
1607 // 2. mentioned in the type params/generics
1608 // 3. mentioned in the associated types of the impl
1610 // Those in 1. can only occur if the trait is in
1611 // this crate and will've been warned about on the
1612 // trait definition (there's no need to warn twice
1613 // so we don't check the methods).
1615 // Those in 2. are warned via walk_generics and this
1617 intravisit::walk_path(self, &tr.path);
1619 // Those in 3. are warned with this call.
1620 for impl_item_ref in items {
1621 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1622 if let hir::ImplItemKind::TyAlias(ref ty) = impl_item.kind {
1628 } else if of_trait.is_none() && self_is_public_path {
1629 // `impl Public<Private> { ... }`. Any public static
1630 // methods will be visible as `Public::foo`.
1631 let mut found_pub_static = false;
1632 for impl_item_ref in items {
1633 if self.item_is_public(&impl_item_ref.id.hir_id, &impl_item_ref.vis) {
1634 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1635 match impl_item_ref.kind {
1636 AssocItemKind::Const => {
1637 found_pub_static = true;
1638 intravisit::walk_impl_item(self, impl_item);
1640 AssocItemKind::Fn { has_self: false } => {
1641 found_pub_static = true;
1642 intravisit::walk_impl_item(self, impl_item);
1648 if found_pub_static {
1649 intravisit::walk_generics(self, g)
1655 // `type ... = ...;` can contain private types, because
1656 // we're introducing a new name.
1657 hir::ItemKind::TyAlias(..) => return,
1659 // Not at all public, so we don't care.
1660 _ if !self.item_is_public(&item.hir_id, &item.vis) => {
1667 // We've carefully constructed it so that if we're here, then
1668 // any `visit_ty`'s will be called on things that are in
1669 // public signatures, i.e., things that we're interested in for
1671 intravisit::walk_item(self, item);
1674 fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
1675 for param in generics.params {
1676 for bound in param.bounds {
1677 self.check_generic_bound(bound);
1680 for predicate in generics.where_clause.predicates {
1682 hir::WherePredicate::BoundPredicate(bound_pred) => {
1683 for bound in bound_pred.bounds.iter() {
1684 self.check_generic_bound(bound)
1687 hir::WherePredicate::RegionPredicate(_) => {}
1688 hir::WherePredicate::EqPredicate(eq_pred) => {
1689 self.visit_ty(&eq_pred.rhs_ty);
1695 fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem<'tcx>) {
1696 if self.access_levels.is_reachable(item.hir_id) {
1697 intravisit::walk_foreign_item(self, item)
1701 fn visit_ty(&mut self, t: &'tcx hir::Ty<'tcx>) {
1702 if let hir::TyKind::Path(hir::QPath::Resolved(_, ref path)) = t.kind {
1703 if self.path_is_private_type(path) {
1704 self.old_error_set.insert(t.hir_id);
1707 intravisit::walk_ty(self, t)
1712 v: &'tcx hir::Variant<'tcx>,
1713 g: &'tcx hir::Generics<'tcx>,
1714 item_id: hir::HirId,
1716 if self.access_levels.is_reachable(v.id) {
1717 self.in_variant = true;
1718 intravisit::walk_variant(self, v, g, item_id);
1719 self.in_variant = false;
1723 fn visit_struct_field(&mut self, s: &'tcx hir::StructField<'tcx>) {
1724 if s.vis.node.is_pub() || self.in_variant {
1725 intravisit::walk_struct_field(self, s);
1729 // We don't need to introspect into these at all: an
1730 // expression/block context can't possibly contain exported things.
1731 // (Making them no-ops stops us from traversing the whole AST without
1732 // having to be super careful about our `walk_...` calls above.)
1733 fn visit_block(&mut self, _: &'tcx hir::Block<'tcx>) {}
1734 fn visit_expr(&mut self, _: &'tcx hir::Expr<'tcx>) {}
1737 ///////////////////////////////////////////////////////////////////////////////
1738 /// SearchInterfaceForPrivateItemsVisitor traverses an item's interface and
1739 /// finds any private components in it.
1740 /// PrivateItemsInPublicInterfacesVisitor ensures there are no private types
1741 /// and traits in public interfaces.
1742 ///////////////////////////////////////////////////////////////////////////////
1744 struct SearchInterfaceForPrivateItemsVisitor<'tcx> {
1746 item_id: hir::HirId,
1749 /// The visitor checks that each component type is at least this visible.
1750 required_visibility: ty::Visibility,
1751 has_pub_restricted: bool,
1752 has_old_errors: bool,
1756 impl SearchInterfaceForPrivateItemsVisitor<'tcx> {
1757 fn generics(&mut self) -> &mut Self {
1758 for param in &self.tcx.generics_of(self.item_def_id).params {
1760 GenericParamDefKind::Lifetime => {}
1761 GenericParamDefKind::Type { has_default, .. } => {
1763 self.visit(self.tcx.type_of(param.def_id));
1766 GenericParamDefKind::Const => {
1767 self.visit(self.tcx.type_of(param.def_id));
1774 fn predicates(&mut self) -> &mut Self {
1775 // N.B., we use `explicit_predicates_of` and not `predicates_of`
1776 // because we don't want to report privacy errors due to where
1777 // clauses that the compiler inferred. We only want to
1778 // consider the ones that the user wrote. This is important
1779 // for the inferred outlives rules; see
1780 // `src/test/ui/rfc-2093-infer-outlives/privacy.rs`.
1781 self.visit_predicates(self.tcx.explicit_predicates_of(self.item_def_id));
1785 fn ty(&mut self) -> &mut Self {
1786 self.visit(self.tcx.type_of(self.item_def_id));
1790 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1791 if self.leaks_private_dep(def_id) {
1792 self.tcx.struct_span_lint_hir(
1793 lint::builtin::EXPORTED_PRIVATE_DEPENDENCIES,
1797 lint.build(&format!(
1798 "{} `{}` from private dependency '{}' in public \
1802 self.tcx.crate_name(def_id.krate)
1809 let hir_id = match def_id.as_local() {
1810 Some(def_id) => self.tcx.hir().as_local_hir_id(def_id),
1811 None => return false,
1814 let (vis, vis_span, vis_descr) = def_id_visibility(self.tcx, def_id);
1815 if !vis.is_at_least(self.required_visibility, self.tcx) {
1816 let make_msg = || format!("{} {} `{}` in public interface", vis_descr, kind, descr);
1817 if self.has_pub_restricted || self.has_old_errors || self.in_assoc_ty {
1818 let mut err = if kind == "trait" {
1819 struct_span_err!(self.tcx.sess, self.span, E0445, "{}", make_msg())
1821 struct_span_err!(self.tcx.sess, self.span, E0446, "{}", make_msg())
1823 err.span_label(self.span, format!("can't leak {} {}", vis_descr, kind));
1824 err.span_label(vis_span, format!("`{}` declared as {}", descr, vis_descr));
1827 let err_code = if kind == "trait" { "E0445" } else { "E0446" };
1828 self.tcx.struct_span_lint_hir(
1829 lint::builtin::PRIVATE_IN_PUBLIC,
1832 |lint| lint.build(&format!("{} (error {})", make_msg(), err_code)).emit(),
1840 /// An item is 'leaked' from a private dependency if all
1841 /// of the following are true:
1842 /// 1. It's contained within a public type
1843 /// 2. It comes from a private crate
1844 fn leaks_private_dep(&self, item_id: DefId) -> bool {
1845 let ret = self.required_visibility == ty::Visibility::Public
1846 && self.tcx.is_private_dep(item_id.krate);
1848 log::debug!("leaks_private_dep(item_id={:?})={}", item_id, ret);
1853 impl DefIdVisitor<'tcx> for SearchInterfaceForPrivateItemsVisitor<'tcx> {
1854 fn tcx(&self) -> TyCtxt<'tcx> {
1857 fn visit_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1858 self.check_def_id(def_id, kind, descr)
1862 struct PrivateItemsInPublicInterfacesVisitor<'a, 'tcx> {
1864 has_pub_restricted: bool,
1865 old_error_set: &'a HirIdSet,
1868 impl<'a, 'tcx> PrivateItemsInPublicInterfacesVisitor<'a, 'tcx> {
1871 item_id: hir::HirId,
1872 required_visibility: ty::Visibility,
1873 ) -> SearchInterfaceForPrivateItemsVisitor<'tcx> {
1874 let mut has_old_errors = false;
1876 // Slow path taken only if there any errors in the crate.
1877 for &id in self.old_error_set {
1878 // Walk up the nodes until we find `item_id` (or we hit a root).
1882 has_old_errors = true;
1885 let parent = self.tcx.hir().get_parent_node(id);
1897 SearchInterfaceForPrivateItemsVisitor {
1900 item_def_id: self.tcx.hir().local_def_id(item_id).to_def_id(),
1901 span: self.tcx.hir().span(item_id),
1902 required_visibility,
1903 has_pub_restricted: self.has_pub_restricted,
1909 fn check_assoc_item(
1912 assoc_item_kind: AssocItemKind,
1913 defaultness: hir::Defaultness,
1914 vis: ty::Visibility,
1916 let mut check = self.check(hir_id, vis);
1918 let (check_ty, is_assoc_ty) = match assoc_item_kind {
1919 AssocItemKind::Const | AssocItemKind::Fn { .. } => (true, false),
1920 AssocItemKind::Type => (defaultness.has_value(), true),
1922 check.in_assoc_ty = is_assoc_ty;
1923 check.generics().predicates();
1930 impl<'a, 'tcx> Visitor<'tcx> for PrivateItemsInPublicInterfacesVisitor<'a, 'tcx> {
1931 type Map = Map<'tcx>;
1933 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1934 NestedVisitorMap::OnlyBodies(self.tcx.hir())
1937 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1939 let item_visibility = ty::Visibility::from_hir(&item.vis, item.hir_id, tcx);
1942 // Crates are always public.
1943 hir::ItemKind::ExternCrate(..) => {}
1944 // All nested items are checked by `visit_item`.
1945 hir::ItemKind::Mod(..) => {}
1946 // Checked in resolve.
1947 hir::ItemKind::Use(..) => {}
1949 hir::ItemKind::GlobalAsm(..) => {}
1950 // Subitems of these items have inherited publicity.
1951 hir::ItemKind::Const(..)
1952 | hir::ItemKind::Static(..)
1953 | hir::ItemKind::Fn(..)
1954 | hir::ItemKind::TyAlias(..) => {
1955 self.check(item.hir_id, item_visibility).generics().predicates().ty();
1957 hir::ItemKind::OpaqueTy(..) => {
1958 // `ty()` for opaque types is the underlying type,
1959 // it's not a part of interface, so we skip it.
1960 self.check(item.hir_id, item_visibility).generics().predicates();
1962 hir::ItemKind::Trait(.., trait_item_refs) => {
1963 self.check(item.hir_id, item_visibility).generics().predicates();
1965 for trait_item_ref in trait_item_refs {
1966 self.check_assoc_item(
1967 trait_item_ref.id.hir_id,
1968 trait_item_ref.kind,
1969 trait_item_ref.defaultness,
1974 hir::ItemKind::TraitAlias(..) => {
1975 self.check(item.hir_id, item_visibility).generics().predicates();
1977 hir::ItemKind::Enum(ref def, _) => {
1978 self.check(item.hir_id, item_visibility).generics().predicates();
1980 for variant in def.variants {
1981 for field in variant.data.fields() {
1982 self.check(field.hir_id, item_visibility).ty();
1986 // Subitems of foreign modules have their own publicity.
1987 hir::ItemKind::ForeignMod(ref foreign_mod) => {
1988 for foreign_item in foreign_mod.items {
1989 let vis = ty::Visibility::from_hir(&foreign_item.vis, item.hir_id, tcx);
1990 self.check(foreign_item.hir_id, vis).generics().predicates().ty();
1993 // Subitems of structs and unions have their own publicity.
1994 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
1995 self.check(item.hir_id, item_visibility).generics().predicates();
1997 for field in struct_def.fields() {
1998 let field_visibility = ty::Visibility::from_hir(&field.vis, item.hir_id, tcx);
1999 self.check(field.hir_id, min(item_visibility, field_visibility, tcx)).ty();
2002 // An inherent impl is public when its type is public
2003 // Subitems of inherent impls have their own publicity.
2004 // A trait impl is public when both its type and its trait are public
2005 // Subitems of trait impls have inherited publicity.
2006 hir::ItemKind::Impl { ref of_trait, items, .. } => {
2007 let impl_vis = ty::Visibility::of_impl(item.hir_id, tcx, &Default::default());
2008 self.check(item.hir_id, impl_vis).generics().predicates();
2009 for impl_item_ref in items {
2010 let impl_item = tcx.hir().impl_item(impl_item_ref.id);
2011 let impl_item_vis = if of_trait.is_none() {
2013 ty::Visibility::from_hir(&impl_item.vis, item.hir_id, tcx),
2020 self.check_assoc_item(
2021 impl_item_ref.id.hir_id,
2023 impl_item_ref.defaultness,
2032 pub fn provide(providers: &mut Providers) {
2033 *providers = Providers {
2034 privacy_access_levels,
2035 check_private_in_public,
2041 fn check_mod_privacy(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
2042 // Check privacy of names not checked in previous compilation stages.
2043 let mut visitor = NamePrivacyVisitor { tcx, maybe_typeck_tables: None, current_item: None };
2044 let (module, span, hir_id) = tcx.hir().get_module(module_def_id);
2046 intravisit::walk_mod(&mut visitor, module, hir_id);
2048 // Check privacy of explicitly written types and traits as well as
2049 // inferred types of expressions and patterns.
2051 TypePrivacyVisitor { tcx, maybe_typeck_tables: None, current_item: module_def_id, span };
2052 intravisit::walk_mod(&mut visitor, module, hir_id);
2055 fn privacy_access_levels(tcx: TyCtxt<'_>, krate: CrateNum) -> &AccessLevels {
2056 assert_eq!(krate, LOCAL_CRATE);
2058 // Build up a set of all exported items in the AST. This is a set of all
2059 // items which are reachable from external crates based on visibility.
2060 let mut visitor = EmbargoVisitor {
2062 access_levels: Default::default(),
2063 macro_reachable: Default::default(),
2064 prev_level: Some(AccessLevel::Public),
2068 intravisit::walk_crate(&mut visitor, tcx.hir().krate());
2069 if visitor.changed {
2070 visitor.changed = false;
2075 visitor.update(hir::CRATE_HIR_ID, Some(AccessLevel::Public));
2077 tcx.arena.alloc(visitor.access_levels)
2080 fn check_private_in_public(tcx: TyCtxt<'_>, krate: CrateNum) {
2081 assert_eq!(krate, LOCAL_CRATE);
2083 let access_levels = tcx.privacy_access_levels(LOCAL_CRATE);
2085 let krate = tcx.hir().krate();
2087 let mut visitor = ObsoleteVisiblePrivateTypesVisitor {
2089 access_levels: &access_levels,
2091 old_error_set: Default::default(),
2093 intravisit::walk_crate(&mut visitor, krate);
2095 let has_pub_restricted = {
2096 let mut pub_restricted_visitor = PubRestrictedVisitor { tcx, has_pub_restricted: false };
2097 intravisit::walk_crate(&mut pub_restricted_visitor, krate);
2098 pub_restricted_visitor.has_pub_restricted
2101 // Check for private types and traits in public interfaces.
2102 let mut visitor = PrivateItemsInPublicInterfacesVisitor {
2105 old_error_set: &visitor.old_error_set,
2107 krate.visit_all_item_likes(&mut DeepVisitor::new(&mut visitor));