1 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
3 #![feature(control_flow_enum)]
4 #![feature(try_blocks)]
5 #![feature(associated_type_defaults)]
6 #![recursion_limit = "256"]
7 #![allow(rustc::potential_query_instability)]
9 use rustc_ast::MacroDef;
10 use rustc_attr as attr;
11 use rustc_data_structures::fx::FxHashSet;
12 use rustc_errors::struct_span_err;
14 use rustc_hir::def::{DefKind, Res};
15 use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdSet, CRATE_DEF_ID};
16 use rustc_hir::intravisit::{self, DeepVisitor, Visitor};
17 use rustc_hir::{AssocItemKind, HirIdSet, Node, PatKind};
18 use rustc_middle::bug;
19 use rustc_middle::hir::nested_filter;
20 use rustc_middle::middle::privacy::{AccessLevel, AccessLevels};
21 use rustc_middle::span_bug;
22 use rustc_middle::thir::abstract_const::Node as ACNode;
23 use rustc_middle::ty::fold::TypeVisitor;
24 use rustc_middle::ty::query::Providers;
25 use rustc_middle::ty::subst::InternalSubsts;
26 use rustc_middle::ty::{self, Const, GenericParamDefKind, TraitRef, Ty, TyCtxt, TypeFoldable};
27 use rustc_session::lint;
28 use rustc_span::hygiene::Transparency;
29 use rustc_span::symbol::{kw, Ident};
31 use rustc_trait_selection::traits::const_evaluatable::{self, AbstractConst};
33 use std::marker::PhantomData;
34 use std::ops::ControlFlow;
35 use std::{cmp, fmt, mem};
37 ////////////////////////////////////////////////////////////////////////////////
38 /// Generic infrastructure used to implement specific visitors below.
39 ////////////////////////////////////////////////////////////////////////////////
41 /// Implemented to visit all `DefId`s in a type.
42 /// Visiting `DefId`s is useful because visibilities and reachabilities are attached to them.
43 /// The idea is to visit "all components of a type", as documented in
44 /// <https://github.com/rust-lang/rfcs/blob/master/text/2145-type-privacy.md#how-to-determine-visibility-of-a-type>.
45 /// The default type visitor (`TypeVisitor`) does most of the job, but it has some shortcomings.
46 /// First, it doesn't have overridable `fn visit_trait_ref`, so we have to catch trait `DefId`s
47 /// manually. Second, it doesn't visit some type components like signatures of fn types, or traits
48 /// in `impl Trait`, see individual comments in `DefIdVisitorSkeleton::visit_ty`.
49 trait DefIdVisitor<'tcx> {
52 fn tcx(&self) -> TyCtxt<'tcx>;
53 fn shallow(&self) -> bool {
56 fn skip_assoc_tys(&self) -> bool {
63 descr: &dyn fmt::Display,
64 ) -> ControlFlow<Self::BreakTy>;
66 /// Not overridden, but used to actually visit types and traits.
67 fn skeleton(&mut self) -> DefIdVisitorSkeleton<'_, 'tcx, Self> {
68 DefIdVisitorSkeleton {
70 visited_opaque_tys: Default::default(),
71 dummy: Default::default(),
74 fn visit(&mut self, ty_fragment: impl TypeFoldable<'tcx>) -> ControlFlow<Self::BreakTy> {
75 ty_fragment.visit_with(&mut self.skeleton())
77 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> ControlFlow<Self::BreakTy> {
78 self.skeleton().visit_trait(trait_ref)
80 fn visit_projection_ty(
82 projection: ty::ProjectionTy<'tcx>,
83 ) -> ControlFlow<Self::BreakTy> {
84 self.skeleton().visit_projection_ty(projection)
88 predicates: ty::GenericPredicates<'tcx>,
89 ) -> ControlFlow<Self::BreakTy> {
90 self.skeleton().visit_predicates(predicates)
94 struct DefIdVisitorSkeleton<'v, 'tcx, V: ?Sized> {
95 def_id_visitor: &'v mut V,
96 visited_opaque_tys: FxHashSet<DefId>,
97 dummy: PhantomData<TyCtxt<'tcx>>,
100 impl<'tcx, V> DefIdVisitorSkeleton<'_, 'tcx, V>
102 V: DefIdVisitor<'tcx> + ?Sized,
104 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> ControlFlow<V::BreakTy> {
105 let TraitRef { def_id, substs } = trait_ref;
106 self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref.print_only_trait_path())?;
107 if self.def_id_visitor.shallow() { ControlFlow::CONTINUE } else { substs.visit_with(self) }
110 fn visit_projection_ty(
112 projection: ty::ProjectionTy<'tcx>,
113 ) -> ControlFlow<V::BreakTy> {
114 let (trait_ref, assoc_substs) =
115 projection.trait_ref_and_own_substs(self.def_id_visitor.tcx());
116 self.visit_trait(trait_ref)?;
117 if self.def_id_visitor.shallow() {
118 ControlFlow::CONTINUE
120 assoc_substs.iter().try_for_each(|subst| subst.visit_with(self))
124 fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> ControlFlow<V::BreakTy> {
125 match predicate.kind().skip_binder() {
126 ty::PredicateKind::Trait(ty::TraitPredicate {
130 }) => self.visit_trait(trait_ref),
131 ty::PredicateKind::Projection(ty::ProjectionPredicate { projection_ty, term }) => {
132 term.visit_with(self)?;
133 self.visit_projection_ty(projection_ty)
135 ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(ty, _region)) => {
138 ty::PredicateKind::RegionOutlives(..) => ControlFlow::CONTINUE,
139 ty::PredicateKind::ConstEvaluatable(uv)
140 if self.def_id_visitor.tcx().features().generic_const_exprs =>
142 let tcx = self.def_id_visitor.tcx();
143 if let Ok(Some(ct)) = AbstractConst::new(tcx, uv) {
144 self.visit_abstract_const_expr(tcx, ct)?;
146 ControlFlow::CONTINUE
148 _ => bug!("unexpected predicate: {:?}", predicate),
152 fn visit_abstract_const_expr(
155 ct: AbstractConst<'tcx>,
156 ) -> ControlFlow<V::BreakTy> {
157 const_evaluatable::walk_abstract_const(tcx, ct, |node| match node.root(tcx) {
158 ACNode::Leaf(leaf) => self.visit_const(leaf),
159 ACNode::Cast(_, _, ty) => self.visit_ty(ty),
160 ACNode::Binop(..) | ACNode::UnaryOp(..) | ACNode::FunctionCall(_, _) => {
161 ControlFlow::CONTINUE
168 predicates: ty::GenericPredicates<'tcx>,
169 ) -> ControlFlow<V::BreakTy> {
170 let ty::GenericPredicates { parent: _, predicates } = predicates;
171 predicates.iter().try_for_each(|&(predicate, _span)| self.visit_predicate(predicate))
175 impl<'tcx, V> TypeVisitor<'tcx> for DefIdVisitorSkeleton<'_, 'tcx, V>
177 V: DefIdVisitor<'tcx> + ?Sized,
179 type BreakTy = V::BreakTy;
181 fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<V::BreakTy> {
182 let tcx = self.def_id_visitor.tcx();
183 // InternalSubsts are not visited here because they are visited below in `super_visit_with`.
185 ty::Adt(&ty::AdtDef { did: def_id, .. }, ..)
186 | ty::Foreign(def_id)
187 | ty::FnDef(def_id, ..)
188 | ty::Closure(def_id, ..)
189 | ty::Generator(def_id, ..) => {
190 self.def_id_visitor.visit_def_id(def_id, "type", &ty)?;
191 if self.def_id_visitor.shallow() {
192 return ControlFlow::CONTINUE;
194 // Default type visitor doesn't visit signatures of fn types.
195 // Something like `fn() -> Priv {my_func}` is considered a private type even if
196 // `my_func` is public, so we need to visit signatures.
197 if let ty::FnDef(..) = ty.kind() {
198 tcx.fn_sig(def_id).visit_with(self)?;
200 // Inherent static methods don't have self type in substs.
201 // Something like `fn() {my_method}` type of the method
202 // `impl Pub<Priv> { pub fn my_method() {} }` is considered a private type,
203 // so we need to visit the self type additionally.
204 if let Some(assoc_item) = tcx.opt_associated_item(def_id) {
205 if let ty::ImplContainer(impl_def_id) = assoc_item.container {
206 tcx.type_of(impl_def_id).visit_with(self)?;
210 ty::Projection(proj) => {
211 if self.def_id_visitor.skip_assoc_tys() {
212 // Visitors searching for minimal visibility/reachability want to
213 // conservatively approximate associated types like `<Type as Trait>::Alias`
214 // as visible/reachable even if both `Type` and `Trait` are private.
215 // Ideally, associated types should be substituted in the same way as
216 // free type aliases, but this isn't done yet.
217 return ControlFlow::CONTINUE;
219 // This will also visit substs if necessary, so we don't need to recurse.
220 return self.visit_projection_ty(proj);
222 ty::Dynamic(predicates, ..) => {
223 // All traits in the list are considered the "primary" part of the type
224 // and are visited by shallow visitors.
225 for predicate in predicates {
226 let trait_ref = match predicate.skip_binder() {
227 ty::ExistentialPredicate::Trait(trait_ref) => trait_ref,
228 ty::ExistentialPredicate::Projection(proj) => proj.trait_ref(tcx),
229 ty::ExistentialPredicate::AutoTrait(def_id) => {
230 ty::ExistentialTraitRef { def_id, substs: InternalSubsts::empty() }
233 let ty::ExistentialTraitRef { def_id, substs: _ } = trait_ref;
234 self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref)?;
237 ty::Opaque(def_id, ..) => {
238 // Skip repeated `Opaque`s to avoid infinite recursion.
239 if self.visited_opaque_tys.insert(def_id) {
240 // The intent is to treat `impl Trait1 + Trait2` identically to
241 // `dyn Trait1 + Trait2`. Therefore we ignore def-id of the opaque type itself
242 // (it either has no visibility, or its visibility is insignificant, like
243 // visibilities of type aliases) and recurse into bounds instead to go
244 // through the trait list (default type visitor doesn't visit those traits).
245 // All traits in the list are considered the "primary" part of the type
246 // and are visited by shallow visitors.
247 self.visit_predicates(ty::GenericPredicates {
249 predicates: tcx.explicit_item_bounds(def_id),
253 // These types don't have their own def-ids (but may have subcomponents
254 // with def-ids that should be visited recursively).
270 | ty::GeneratorWitness(..) => {}
271 ty::Bound(..) | ty::Placeholder(..) | ty::Infer(..) => {
272 bug!("unexpected type: {:?}", ty)
276 if self.def_id_visitor.shallow() {
277 ControlFlow::CONTINUE
279 ty.super_visit_with(self)
283 fn visit_const(&mut self, c: Const<'tcx>) -> ControlFlow<Self::BreakTy> {
284 self.visit_ty(c.ty())?;
285 let tcx = self.def_id_visitor.tcx();
286 if let Ok(Some(ct)) = AbstractConst::from_const(tcx, c) {
287 self.visit_abstract_const_expr(tcx, ct)?;
289 ControlFlow::CONTINUE
293 fn min(vis1: ty::Visibility, vis2: ty::Visibility, tcx: TyCtxt<'_>) -> ty::Visibility {
294 if vis1.is_at_least(vis2, tcx) { vis2 } else { vis1 }
297 ////////////////////////////////////////////////////////////////////////////////
298 /// Visitor used to determine if pub(restricted) is used anywhere in the crate.
300 /// This is done so that `private_in_public` warnings can be turned into hard errors
301 /// in crates that have been updated to use pub(restricted).
302 ////////////////////////////////////////////////////////////////////////////////
303 struct PubRestrictedVisitor<'tcx> {
305 has_pub_restricted: bool,
308 impl<'tcx> Visitor<'tcx> for PubRestrictedVisitor<'tcx> {
309 type NestedFilter = nested_filter::All;
311 fn nested_visit_map(&mut self) -> Self::Map {
314 fn visit_vis(&mut self, vis: &'tcx hir::Visibility<'tcx>) {
315 self.has_pub_restricted = self.has_pub_restricted || vis.node.is_pub_restricted();
319 ////////////////////////////////////////////////////////////////////////////////
320 /// Visitor used to determine impl visibility and reachability.
321 ////////////////////////////////////////////////////////////////////////////////
323 struct FindMin<'a, 'tcx, VL: VisibilityLike> {
325 access_levels: &'a AccessLevels,
329 impl<'a, 'tcx, VL: VisibilityLike> DefIdVisitor<'tcx> for FindMin<'a, 'tcx, VL> {
330 fn tcx(&self) -> TyCtxt<'tcx> {
333 fn shallow(&self) -> bool {
336 fn skip_assoc_tys(&self) -> bool {
343 _descr: &dyn fmt::Display,
344 ) -> ControlFlow<Self::BreakTy> {
345 self.min = VL::new_min(self, def_id);
346 ControlFlow::CONTINUE
350 trait VisibilityLike: Sized {
352 const SHALLOW: bool = false;
353 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self;
355 // Returns an over-approximation (`skip_assoc_tys` = true) of visibility due to
356 // associated types for which we can't determine visibility precisely.
357 fn of_impl(def_id: LocalDefId, tcx: TyCtxt<'_>, access_levels: &AccessLevels) -> Self {
358 let mut find = FindMin { tcx, access_levels, min: Self::MAX };
359 find.visit(tcx.type_of(def_id));
360 if let Some(trait_ref) = tcx.impl_trait_ref(def_id) {
361 find.visit_trait(trait_ref);
366 impl VisibilityLike for ty::Visibility {
367 const MAX: Self = ty::Visibility::Public;
368 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
369 min(find.tcx.visibility(def_id), find.min, find.tcx)
372 impl VisibilityLike for Option<AccessLevel> {
373 const MAX: Self = Some(AccessLevel::Public);
374 // Type inference is very smart sometimes.
375 // It can make an impl reachable even some components of its type or trait are unreachable.
376 // E.g. methods of `impl ReachableTrait<UnreachableTy> for ReachableTy<UnreachableTy> { ... }`
377 // can be usable from other crates (#57264). So we skip substs when calculating reachability
378 // and consider an impl reachable if its "shallow" type and trait are reachable.
380 // The assumption we make here is that type-inference won't let you use an impl without knowing
381 // both "shallow" version of its self type and "shallow" version of its trait if it exists
382 // (which require reaching the `DefId`s in them).
383 const SHALLOW: bool = true;
384 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
386 if let Some(def_id) = def_id.as_local() {
387 find.access_levels.map.get(&def_id).copied()
396 ////////////////////////////////////////////////////////////////////////////////
397 /// The embargo visitor, used to determine the exports of the AST.
398 ////////////////////////////////////////////////////////////////////////////////
400 struct EmbargoVisitor<'tcx> {
403 /// Accessibility levels for reachable nodes.
404 access_levels: AccessLevels,
405 /// A set of pairs corresponding to modules, where the first module is
406 /// reachable via a macro that's defined in the second module. This cannot
407 /// be represented as reachable because it can't handle the following case:
409 /// pub mod n { // Should be `Public`
410 /// pub(crate) mod p { // Should *not* be accessible
411 /// pub fn f() -> i32 { 12 } // Must be `Reachable`
417 macro_reachable: FxHashSet<(LocalDefId, LocalDefId)>,
418 /// Previous accessibility level; `None` means unreachable.
419 prev_level: Option<AccessLevel>,
420 /// Has something changed in the level map?
424 struct ReachEverythingInTheInterfaceVisitor<'a, 'tcx> {
425 access_level: Option<AccessLevel>,
426 item_def_id: LocalDefId,
427 ev: &'a mut EmbargoVisitor<'tcx>,
430 impl<'tcx> EmbargoVisitor<'tcx> {
431 fn get(&self, def_id: LocalDefId) -> Option<AccessLevel> {
432 self.access_levels.map.get(&def_id).copied()
435 fn update_with_hir_id(
438 level: Option<AccessLevel>,
439 ) -> Option<AccessLevel> {
440 let def_id = self.tcx.hir().local_def_id(hir_id);
441 self.update(def_id, level)
444 /// Updates node level and returns the updated level.
445 fn update(&mut self, def_id: LocalDefId, level: Option<AccessLevel>) -> Option<AccessLevel> {
446 let old_level = self.get(def_id);
447 // Accessibility levels can only grow.
448 if level > old_level {
449 self.access_levels.map.insert(def_id, level.unwrap());
460 access_level: Option<AccessLevel>,
461 ) -> ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
462 ReachEverythingInTheInterfaceVisitor {
463 access_level: cmp::min(access_level, Some(AccessLevel::Reachable)),
469 // We have to make sure that the items that macros might reference
470 // are reachable, since they might be exported transitively.
471 fn update_reachability_from_macro(&mut self, local_def_id: LocalDefId, md: &MacroDef) {
472 // Non-opaque macros cannot make other items more accessible than they already are.
474 let hir_id = self.tcx.hir().local_def_id_to_hir_id(local_def_id);
475 let attrs = self.tcx.hir().attrs(hir_id);
476 if attr::find_transparency(attrs, md.macro_rules).0 != Transparency::Opaque {
480 let item_def_id = local_def_id.to_def_id();
481 let macro_module_def_id =
482 ty::DefIdTree::parent(self.tcx, item_def_id).unwrap().expect_local();
483 if self.tcx.hir().opt_def_kind(macro_module_def_id) != Some(DefKind::Mod) {
484 // The macro's parent doesn't correspond to a `mod`, return early (#63164, #65252).
488 if self.get(local_def_id).is_none() {
492 // Since we are starting from an externally visible module,
493 // all the parents in the loop below are also guaranteed to be modules.
494 let mut module_def_id = macro_module_def_id;
496 let changed_reachability =
497 self.update_macro_reachable(module_def_id, macro_module_def_id);
498 if changed_reachability || module_def_id == CRATE_DEF_ID {
502 ty::DefIdTree::parent(self.tcx, module_def_id.to_def_id()).unwrap().expect_local();
506 /// Updates the item as being reachable through a macro defined in the given
507 /// module. Returns `true` if the level has changed.
508 fn update_macro_reachable(
510 module_def_id: LocalDefId,
511 defining_mod: LocalDefId,
513 if self.macro_reachable.insert((module_def_id, defining_mod)) {
514 self.update_macro_reachable_mod(module_def_id, defining_mod);
521 fn update_macro_reachable_mod(&mut self, module_def_id: LocalDefId, defining_mod: LocalDefId) {
522 let module = self.tcx.hir().get_module(module_def_id).0;
523 for item_id in module.item_ids {
524 let def_kind = self.tcx.def_kind(item_id.def_id);
525 let vis = self.tcx.visibility(item_id.def_id);
526 self.update_macro_reachable_def(item_id.def_id, def_kind, vis, defining_mod);
528 if let Some(exports) = self.tcx.module_reexports(module_def_id) {
529 for export in exports {
530 if export.vis.is_accessible_from(defining_mod.to_def_id(), self.tcx) {
531 if let Res::Def(def_kind, def_id) = export.res {
532 if let Some(def_id) = def_id.as_local() {
533 let vis = self.tcx.visibility(def_id.to_def_id());
534 self.update_macro_reachable_def(def_id, def_kind, vis, defining_mod);
542 fn update_macro_reachable_def(
549 let level = Some(AccessLevel::Reachable);
551 self.update(def_id, level);
554 // No type privacy, so can be directly marked as reachable.
555 DefKind::Const | DefKind::Static | DefKind::TraitAlias | DefKind::TyAlias => {
556 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
557 self.update(def_id, level);
561 // Hygine isn't really implemented for `macro_rules!` macros at the
562 // moment. Accordingly, marking them as reachable is unwise. `macro` macros
563 // have normal hygine, so we can treat them like other items without type
564 // privacy and mark them reachable.
565 DefKind::Macro(_) => {
566 let item = self.tcx.hir().expect_item(def_id);
567 if let hir::ItemKind::Macro(MacroDef { macro_rules: false, .. }, _) = item.kind {
568 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
569 self.update(def_id, level);
574 // We can't use a module name as the final segment of a path, except
575 // in use statements. Since re-export checking doesn't consider
576 // hygiene these don't need to be marked reachable. The contents of
577 // the module, however may be reachable.
579 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
580 self.update_macro_reachable(def_id, module);
584 DefKind::Struct | DefKind::Union => {
585 // While structs and unions have type privacy, their fields do not.
587 let item = self.tcx.hir().expect_item(def_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() {
592 let def_id = self.tcx.hir().local_def_id(field.hir_id);
593 let field_vis = self.tcx.visibility(def_id);
594 if field_vis.is_accessible_from(module.to_def_id(), self.tcx) {
595 self.reach(def_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
623 | DefKind::InlineConst
628 | DefKind::Generator => (),
633 impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
634 type NestedFilter = nested_filter::All;
636 /// We want to visit items in the context of their containing
637 /// module and so forth, so supply a crate for doing a deep walk.
638 fn nested_visit_map(&mut self) -> Self::Map {
642 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
643 let item_level = match item.kind {
644 hir::ItemKind::Impl { .. } => {
646 Option::<AccessLevel>::of_impl(item.def_id, self.tcx, &self.access_levels);
647 self.update(item.def_id, impl_level)
649 _ => self.get(item.def_id),
652 // Update levels of nested things.
654 hir::ItemKind::Enum(ref def, _) => {
655 for variant in def.variants {
656 let variant_level = self.update_with_hir_id(variant.id, item_level);
657 if let Some(ctor_hir_id) = variant.data.ctor_hir_id() {
658 self.update_with_hir_id(ctor_hir_id, item_level);
660 for field in variant.data.fields() {
661 self.update_with_hir_id(field.hir_id, variant_level);
665 hir::ItemKind::Impl(ref impl_) => {
666 for impl_item_ref in impl_.items {
667 if impl_.of_trait.is_some()
668 || self.tcx.visibility(impl_item_ref.id.def_id) == ty::Visibility::Public
670 self.update(impl_item_ref.id.def_id, item_level);
674 hir::ItemKind::Trait(.., trait_item_refs) => {
675 for trait_item_ref in trait_item_refs {
676 self.update(trait_item_ref.id.def_id, item_level);
679 hir::ItemKind::Struct(ref def, _) | hir::ItemKind::Union(ref def, _) => {
680 if let Some(ctor_hir_id) = def.ctor_hir_id() {
681 self.update_with_hir_id(ctor_hir_id, item_level);
683 for field in def.fields() {
684 if field.vis.node.is_pub() {
685 self.update_with_hir_id(field.hir_id, item_level);
689 hir::ItemKind::Macro(ref macro_def, _) => {
690 self.update_reachability_from_macro(item.def_id, macro_def);
692 hir::ItemKind::ForeignMod { items, .. } => {
693 for foreign_item in items {
694 if self.tcx.visibility(foreign_item.id.def_id) == ty::Visibility::Public {
695 self.update(foreign_item.id.def_id, item_level);
700 hir::ItemKind::OpaqueTy(..)
701 | hir::ItemKind::Use(..)
702 | hir::ItemKind::Static(..)
703 | hir::ItemKind::Const(..)
704 | hir::ItemKind::GlobalAsm(..)
705 | hir::ItemKind::TyAlias(..)
706 | hir::ItemKind::Mod(..)
707 | hir::ItemKind::TraitAlias(..)
708 | hir::ItemKind::Fn(..)
709 | hir::ItemKind::ExternCrate(..) => {}
712 // Mark all items in interfaces of reachable items as reachable.
714 // The interface is empty.
715 hir::ItemKind::Macro(..) | hir::ItemKind::ExternCrate(..) => {}
716 // All nested items are checked by `visit_item`.
717 hir::ItemKind::Mod(..) => {}
718 // Handled in the access level of in rustc_resolve
719 hir::ItemKind::Use(..) => {}
720 // The interface is empty.
721 hir::ItemKind::GlobalAsm(..) => {}
722 hir::ItemKind::OpaqueTy(..) => {
723 // HACK(jynelson): trying to infer the type of `impl trait` breaks `async-std` (and `pub async fn` in general)
724 // Since rustdoc never needs to do codegen and doesn't care about link-time reachability,
725 // mark this as unreachable.
726 // See https://github.com/rust-lang/rust/issues/75100
727 if !self.tcx.sess.opts.actually_rustdoc {
728 // FIXME: This is some serious pessimization intended to workaround deficiencies
729 // in the reachability pass (`middle/reachable.rs`). Types are marked as link-time
730 // reachable if they are returned via `impl Trait`, even from private functions.
732 cmp::max(item_level, Some(AccessLevel::ReachableFromImplTrait));
733 self.reach(item.def_id, exist_level).generics().predicates().ty();
737 hir::ItemKind::Const(..)
738 | hir::ItemKind::Static(..)
739 | hir::ItemKind::Fn(..)
740 | hir::ItemKind::TyAlias(..) => {
741 if item_level.is_some() {
742 self.reach(item.def_id, item_level).generics().predicates().ty();
745 hir::ItemKind::Trait(.., trait_item_refs) => {
746 if item_level.is_some() {
747 self.reach(item.def_id, item_level).generics().predicates();
749 for trait_item_ref in trait_item_refs {
750 let mut reach = self.reach(trait_item_ref.id.def_id, item_level);
751 reach.generics().predicates();
753 if trait_item_ref.kind == AssocItemKind::Type
754 && !trait_item_ref.defaultness.has_value()
763 hir::ItemKind::TraitAlias(..) => {
764 if item_level.is_some() {
765 self.reach(item.def_id, item_level).generics().predicates();
768 // Visit everything except for private impl items.
769 hir::ItemKind::Impl(ref impl_) => {
770 if item_level.is_some() {
771 self.reach(item.def_id, item_level).generics().predicates().ty().trait_ref();
773 for impl_item_ref in impl_.items {
774 let impl_item_level = self.get(impl_item_ref.id.def_id);
775 if impl_item_level.is_some() {
776 self.reach(impl_item_ref.id.def_id, impl_item_level)
785 // Visit everything, but enum variants have their own levels.
786 hir::ItemKind::Enum(ref def, _) => {
787 if item_level.is_some() {
788 self.reach(item.def_id, item_level).generics().predicates();
790 for variant in def.variants {
791 let variant_level = self.get(self.tcx.hir().local_def_id(variant.id));
792 if variant_level.is_some() {
793 for field in variant.data.fields() {
794 self.reach(self.tcx.hir().local_def_id(field.hir_id), variant_level)
797 // Corner case: if the variant is reachable, but its
798 // enum is not, make the enum reachable as well.
799 self.update(item.def_id, variant_level);
803 // Visit everything, but foreign items have their own levels.
804 hir::ItemKind::ForeignMod { items, .. } => {
805 for foreign_item in items {
806 let foreign_item_level = self.get(foreign_item.id.def_id);
807 if foreign_item_level.is_some() {
808 self.reach(foreign_item.id.def_id, foreign_item_level)
815 // Visit everything except for private fields.
816 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
817 if item_level.is_some() {
818 self.reach(item.def_id, item_level).generics().predicates();
819 for field in struct_def.fields() {
820 let def_id = self.tcx.hir().local_def_id(field.hir_id);
821 let field_level = self.get(def_id);
822 if field_level.is_some() {
823 self.reach(def_id, field_level).ty();
830 let orig_level = mem::replace(&mut self.prev_level, item_level);
831 intravisit::walk_item(self, item);
832 self.prev_level = orig_level;
835 fn visit_block(&mut self, b: &'tcx hir::Block<'tcx>) {
836 // Blocks can have public items, for example impls, but they always
837 // start as completely private regardless of publicity of a function,
838 // constant, type, field, etc., in which this block resides.
839 let orig_level = mem::replace(&mut self.prev_level, None);
840 intravisit::walk_block(self, b);
841 self.prev_level = orig_level;
845 impl ReachEverythingInTheInterfaceVisitor<'_, '_> {
846 fn generics(&mut self) -> &mut Self {
847 for param in &self.ev.tcx.generics_of(self.item_def_id).params {
849 GenericParamDefKind::Lifetime => {}
850 GenericParamDefKind::Type { has_default, .. } => {
852 self.visit(self.ev.tcx.type_of(param.def_id));
855 GenericParamDefKind::Const { has_default, .. } => {
856 self.visit(self.ev.tcx.type_of(param.def_id));
858 self.visit(self.ev.tcx.const_param_default(param.def_id));
866 fn predicates(&mut self) -> &mut Self {
867 self.visit_predicates(self.ev.tcx.predicates_of(self.item_def_id));
871 fn ty(&mut self) -> &mut Self {
872 self.visit(self.ev.tcx.type_of(self.item_def_id));
876 fn trait_ref(&mut self) -> &mut Self {
877 if let Some(trait_ref) = self.ev.tcx.impl_trait_ref(self.item_def_id) {
878 self.visit_trait(trait_ref);
884 impl<'tcx> DefIdVisitor<'tcx> for ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
885 fn tcx(&self) -> TyCtxt<'tcx> {
892 _descr: &dyn fmt::Display,
893 ) -> ControlFlow<Self::BreakTy> {
894 if let Some(def_id) = def_id.as_local() {
895 if let (ty::Visibility::Public, _) | (_, Some(AccessLevel::ReachableFromImplTrait)) =
896 (self.tcx().visibility(def_id.to_def_id()), self.access_level)
898 self.ev.update(def_id, self.access_level);
901 ControlFlow::CONTINUE
905 //////////////////////////////////////////////////////////////////////////////////////
906 /// Name privacy visitor, checks privacy and reports violations.
907 /// Most of name privacy checks are performed during the main resolution phase,
908 /// or later in type checking when field accesses and associated items are resolved.
909 /// This pass performs remaining checks for fields in struct expressions and patterns.
910 //////////////////////////////////////////////////////////////////////////////////////
912 struct NamePrivacyVisitor<'tcx> {
914 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
915 current_item: LocalDefId,
918 impl<'tcx> NamePrivacyVisitor<'tcx> {
919 /// Gets the type-checking results for the current body.
920 /// As this will ICE if called outside bodies, only call when working with
921 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
923 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
924 self.maybe_typeck_results
925 .expect("`NamePrivacyVisitor::typeck_results` called outside of body")
928 // Checks that a field in a struct constructor (expression or pattern) is accessible.
931 use_ctxt: Span, // syntax context of the field name at the use site
932 span: Span, // span of the field pattern, e.g., `x: 0`
933 def: &'tcx ty::AdtDef, // definition of the struct or enum
934 field: &'tcx ty::FieldDef,
935 in_update_syntax: bool,
941 // definition of the field
942 let ident = Ident::new(kw::Empty, use_ctxt);
943 let hir_id = self.tcx.hir().local_def_id_to_hir_id(self.current_item);
944 let def_id = self.tcx.adjust_ident_and_get_scope(ident, def.did, hir_id).1;
945 if !field.vis.is_accessible_from(def_id, self.tcx) {
946 let label = if in_update_syntax {
947 format!("field `{}` is private", field.name)
949 "private field".to_string()
956 "field `{}` of {} `{}` is private",
959 self.tcx.def_path_str(def.did)
961 .span_label(span, label)
967 impl<'tcx> Visitor<'tcx> for NamePrivacyVisitor<'tcx> {
968 type NestedFilter = nested_filter::All;
970 /// We want to visit items in the context of their containing
971 /// module and so forth, so supply a crate for doing a deep walk.
972 fn nested_visit_map(&mut self) -> Self::Map {
976 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
977 // Don't visit nested modules, since we run a separate visitor walk
978 // for each module in `privacy_access_levels`
981 fn visit_nested_body(&mut self, body: hir::BodyId) {
982 let old_maybe_typeck_results =
983 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
984 let body = self.tcx.hir().body(body);
985 self.visit_body(body);
986 self.maybe_typeck_results = old_maybe_typeck_results;
989 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
990 let orig_current_item = mem::replace(&mut self.current_item, item.def_id);
991 intravisit::walk_item(self, item);
992 self.current_item = orig_current_item;
995 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
996 if let hir::ExprKind::Struct(qpath, fields, ref base) = expr.kind {
997 let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
998 let adt = self.typeck_results().expr_ty(expr).ty_adt_def().unwrap();
999 let variant = adt.variant_of_res(res);
1000 if let Some(base) = *base {
1001 // If the expression uses FRU we need to make sure all the unmentioned fields
1002 // are checked for privacy (RFC 736). Rather than computing the set of
1003 // unmentioned fields, just check them all.
1004 for (vf_index, variant_field) in variant.fields.iter().enumerate() {
1005 let field = fields.iter().find(|f| {
1006 self.tcx.field_index(f.hir_id, self.typeck_results()) == vf_index
1008 let (use_ctxt, span) = match field {
1009 Some(field) => (field.ident.span, field.span),
1010 None => (base.span, base.span),
1012 self.check_field(use_ctxt, span, adt, variant_field, true);
1015 for field in fields {
1016 let use_ctxt = field.ident.span;
1017 let index = self.tcx.field_index(field.hir_id, self.typeck_results());
1018 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1023 intravisit::walk_expr(self, expr);
1026 fn visit_pat(&mut self, pat: &'tcx hir::Pat<'tcx>) {
1027 if let PatKind::Struct(ref qpath, fields, _) = pat.kind {
1028 let res = self.typeck_results().qpath_res(qpath, pat.hir_id);
1029 let adt = self.typeck_results().pat_ty(pat).ty_adt_def().unwrap();
1030 let variant = adt.variant_of_res(res);
1031 for field in fields {
1032 let use_ctxt = field.ident.span;
1033 let index = self.tcx.field_index(field.hir_id, self.typeck_results());
1034 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1038 intravisit::walk_pat(self, pat);
1042 ////////////////////////////////////////////////////////////////////////////////////////////
1043 /// Type privacy visitor, checks types for privacy and reports violations.
1044 /// Both explicitly written types and inferred types of expressions and patterns are checked.
1045 /// Checks are performed on "semantic" types regardless of names and their hygiene.
1046 ////////////////////////////////////////////////////////////////////////////////////////////
1048 struct TypePrivacyVisitor<'tcx> {
1050 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
1051 current_item: LocalDefId,
1055 impl<'tcx> TypePrivacyVisitor<'tcx> {
1056 /// Gets the type-checking results for the current body.
1057 /// As this will ICE if called outside bodies, only call when working with
1058 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
1060 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
1061 self.maybe_typeck_results
1062 .expect("`TypePrivacyVisitor::typeck_results` called outside of body")
1065 fn item_is_accessible(&self, did: DefId) -> bool {
1066 self.tcx.visibility(did).is_accessible_from(self.current_item.to_def_id(), self.tcx)
1069 // Take node-id of an expression or pattern and check its type for privacy.
1070 fn check_expr_pat_type(&mut self, id: hir::HirId, span: Span) -> bool {
1072 let typeck_results = self.typeck_results();
1073 let result: ControlFlow<()> = try {
1074 self.visit(typeck_results.node_type(id))?;
1075 self.visit(typeck_results.node_substs(id))?;
1076 if let Some(adjustments) = typeck_results.adjustments().get(id) {
1077 adjustments.iter().try_for_each(|adjustment| self.visit(adjustment.target))?;
1083 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1084 let is_error = !self.item_is_accessible(def_id);
1088 .struct_span_err(self.span, &format!("{} `{}` is private", kind, descr))
1089 .span_label(self.span, &format!("private {}", kind))
1096 impl<'tcx> Visitor<'tcx> for TypePrivacyVisitor<'tcx> {
1097 type NestedFilter = nested_filter::All;
1099 /// We want to visit items in the context of their containing
1100 /// module and so forth, so supply a crate for doing a deep walk.
1101 fn nested_visit_map(&mut self) -> Self::Map {
1105 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
1106 // Don't visit nested modules, since we run a separate visitor walk
1107 // for each module in `privacy_access_levels`
1110 fn visit_nested_body(&mut self, body: hir::BodyId) {
1111 let old_maybe_typeck_results =
1112 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
1113 let body = self.tcx.hir().body(body);
1114 self.visit_body(body);
1115 self.maybe_typeck_results = old_maybe_typeck_results;
1118 fn visit_generic_arg(&mut self, generic_arg: &'tcx hir::GenericArg<'tcx>) {
1120 hir::GenericArg::Type(t) => self.visit_ty(t),
1121 hir::GenericArg::Infer(inf) => self.visit_infer(inf),
1122 hir::GenericArg::Lifetime(_) | hir::GenericArg::Const(_) => {}
1126 fn visit_ty(&mut self, hir_ty: &'tcx hir::Ty<'tcx>) {
1127 self.span = hir_ty.span;
1128 if let Some(typeck_results) = self.maybe_typeck_results {
1130 if self.visit(typeck_results.node_type(hir_ty.hir_id)).is_break() {
1134 // Types in signatures.
1135 // FIXME: This is very ineffective. Ideally each HIR type should be converted
1136 // into a semantic type only once and the result should be cached somehow.
1137 if self.visit(rustc_typeck::hir_ty_to_ty(self.tcx, hir_ty)).is_break() {
1142 intravisit::walk_ty(self, hir_ty);
1145 fn visit_infer(&mut self, inf: &'tcx hir::InferArg) {
1146 self.span = inf.span;
1147 if let Some(typeck_results) = self.maybe_typeck_results {
1148 if let Some(ty) = typeck_results.node_type_opt(inf.hir_id) {
1149 if self.visit(ty).is_break() {
1153 // We don't do anything for const infers here.
1156 bug!("visit_infer without typeck_results");
1158 intravisit::walk_inf(self, inf);
1161 fn visit_trait_ref(&mut self, trait_ref: &'tcx hir::TraitRef<'tcx>) {
1162 self.span = trait_ref.path.span;
1163 if self.maybe_typeck_results.is_none() {
1164 // Avoid calling `hir_trait_to_predicates` in bodies, it will ICE.
1165 // The traits' privacy in bodies is already checked as a part of trait object types.
1166 let bounds = rustc_typeck::hir_trait_to_predicates(
1169 // NOTE: This isn't really right, but the actual type doesn't matter here. It's
1170 // just required by `ty::TraitRef`.
1171 self.tcx.types.never,
1174 for (trait_predicate, _, _) in bounds.trait_bounds {
1175 if self.visit_trait(trait_predicate.skip_binder()).is_break() {
1180 for (poly_predicate, _) in bounds.projection_bounds {
1181 let pred = poly_predicate.skip_binder();
1182 let poly_pred_term = self.visit(pred.term);
1183 if poly_pred_term.is_break()
1184 || self.visit_projection_ty(pred.projection_ty).is_break()
1191 intravisit::walk_trait_ref(self, trait_ref);
1194 // Check types of expressions
1195 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
1196 if self.check_expr_pat_type(expr.hir_id, expr.span) {
1197 // Do not check nested expressions if the error already happened.
1201 hir::ExprKind::Assign(_, rhs, _) | hir::ExprKind::Match(rhs, ..) => {
1202 // Do not report duplicate errors for `x = y` and `match x { ... }`.
1203 if self.check_expr_pat_type(rhs.hir_id, rhs.span) {
1207 hir::ExprKind::MethodCall(segment, ..) => {
1208 // Method calls have to be checked specially.
1209 self.span = segment.ident.span;
1210 if let Some(def_id) = self.typeck_results().type_dependent_def_id(expr.hir_id) {
1211 if self.visit(self.tcx.type_of(def_id)).is_break() {
1217 .delay_span_bug(expr.span, "no type-dependent def for method call");
1223 intravisit::walk_expr(self, expr);
1226 // Prohibit access to associated items with insufficient nominal visibility.
1228 // Additionally, until better reachability analysis for macros 2.0 is available,
1229 // we prohibit access to private statics from other crates, this allows to give
1230 // more code internal visibility at link time. (Access to private functions
1231 // is already prohibited by type privacy for function types.)
1232 fn visit_qpath(&mut self, qpath: &'tcx hir::QPath<'tcx>, id: hir::HirId, span: Span) {
1233 let def = match qpath {
1234 hir::QPath::Resolved(_, path) => match path.res {
1235 Res::Def(kind, def_id) => Some((kind, def_id)),
1238 hir::QPath::TypeRelative(..) | hir::QPath::LangItem(..) => self
1239 .maybe_typeck_results
1240 .and_then(|typeck_results| typeck_results.type_dependent_def(id)),
1242 let def = def.filter(|(kind, _)| {
1245 DefKind::AssocFn | DefKind::AssocConst | DefKind::AssocTy | DefKind::Static
1248 if let Some((kind, def_id)) = def {
1249 let is_local_static =
1250 if let DefKind::Static = kind { def_id.is_local() } else { false };
1251 if !self.item_is_accessible(def_id) && !is_local_static {
1252 let sess = self.tcx.sess;
1253 let sm = sess.source_map();
1254 let name = match qpath {
1255 hir::QPath::Resolved(..) | hir::QPath::LangItem(..) => {
1256 sm.span_to_snippet(qpath.span()).ok()
1258 hir::QPath::TypeRelative(_, segment) => Some(segment.ident.to_string()),
1260 let kind = kind.descr(def_id);
1261 let msg = match name {
1262 Some(name) => format!("{} `{}` is private", kind, name),
1263 None => format!("{} is private", kind),
1265 sess.struct_span_err(span, &msg)
1266 .span_label(span, &format!("private {}", kind))
1272 intravisit::walk_qpath(self, qpath, id, span);
1275 // Check types of patterns.
1276 fn visit_pat(&mut self, pattern: &'tcx hir::Pat<'tcx>) {
1277 if self.check_expr_pat_type(pattern.hir_id, pattern.span) {
1278 // Do not check nested patterns if the error already happened.
1282 intravisit::walk_pat(self, pattern);
1285 fn visit_local(&mut self, local: &'tcx hir::Local<'tcx>) {
1286 if let Some(init) = local.init {
1287 if self.check_expr_pat_type(init.hir_id, init.span) {
1288 // Do not report duplicate errors for `let x = y`.
1293 intravisit::walk_local(self, local);
1296 // Check types in item interfaces.
1297 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1298 let orig_current_item = mem::replace(&mut self.current_item, item.def_id);
1299 let old_maybe_typeck_results = self.maybe_typeck_results.take();
1300 intravisit::walk_item(self, item);
1301 self.maybe_typeck_results = old_maybe_typeck_results;
1302 self.current_item = orig_current_item;
1306 impl<'tcx> DefIdVisitor<'tcx> for TypePrivacyVisitor<'tcx> {
1307 fn tcx(&self) -> TyCtxt<'tcx> {
1314 descr: &dyn fmt::Display,
1315 ) -> ControlFlow<Self::BreakTy> {
1316 if self.check_def_id(def_id, kind, descr) {
1319 ControlFlow::CONTINUE
1324 ///////////////////////////////////////////////////////////////////////////////
1325 /// Obsolete visitors for checking for private items in public interfaces.
1326 /// These visitors are supposed to be kept in frozen state and produce an
1327 /// "old error node set". For backward compatibility the new visitor reports
1328 /// warnings instead of hard errors when the erroneous node is not in this old set.
1329 ///////////////////////////////////////////////////////////////////////////////
1331 struct ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1333 access_levels: &'a AccessLevels,
1335 // Set of errors produced by this obsolete visitor.
1336 old_error_set: HirIdSet,
1339 struct ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1340 inner: &'a ObsoleteVisiblePrivateTypesVisitor<'b, 'tcx>,
1341 /// Whether the type refers to private types.
1342 contains_private: bool,
1343 /// Whether we've recurred at all (i.e., if we're pointing at the
1344 /// first type on which `visit_ty` was called).
1345 at_outer_type: bool,
1346 /// Whether that first type is a public path.
1347 outer_type_is_public_path: bool,
1350 impl<'a, 'tcx> ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1351 fn path_is_private_type(&self, path: &hir::Path<'_>) -> bool {
1352 let did = match path.res {
1353 Res::PrimTy(..) | Res::SelfTy { .. } | Res::Err => return false,
1354 res => res.def_id(),
1357 // A path can only be private if:
1358 // it's in this crate...
1359 if let Some(did) = did.as_local() {
1360 // .. and it corresponds to a private type in the AST (this returns
1361 // `None` for type parameters).
1362 match self.tcx.hir().find(self.tcx.hir().local_def_id_to_hir_id(did)) {
1363 Some(Node::Item(item)) => !item.vis.node.is_pub(),
1364 Some(_) | None => false,
1371 fn trait_is_public(&self, trait_id: LocalDefId) -> bool {
1372 // FIXME: this would preferably be using `exported_items`, but all
1373 // traits are exported currently (see `EmbargoVisitor.exported_trait`).
1374 self.access_levels.is_public(trait_id)
1377 fn check_generic_bound(&mut self, bound: &hir::GenericBound<'_>) {
1378 if let hir::GenericBound::Trait(ref trait_ref, _) = *bound {
1379 if self.path_is_private_type(trait_ref.trait_ref.path) {
1380 self.old_error_set.insert(trait_ref.trait_ref.hir_ref_id);
1385 fn item_is_public(&self, def_id: LocalDefId, vis: &hir::Visibility<'_>) -> bool {
1386 self.access_levels.is_reachable(def_id) || vis.node.is_pub()
1390 impl<'a, 'b, 'tcx, 'v> Visitor<'v> for ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1391 fn visit_generic_arg(&mut self, generic_arg: &'v hir::GenericArg<'v>) {
1393 hir::GenericArg::Type(t) => self.visit_ty(t),
1394 hir::GenericArg::Infer(inf) => self.visit_ty(&inf.to_ty()),
1395 hir::GenericArg::Lifetime(_) | hir::GenericArg::Const(_) => {}
1399 fn visit_ty(&mut self, ty: &hir::Ty<'_>) {
1400 if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = ty.kind {
1401 if self.inner.path_is_private_type(path) {
1402 self.contains_private = true;
1403 // Found what we're looking for, so let's stop working.
1407 if let hir::TyKind::Path(_) = ty.kind {
1408 if self.at_outer_type {
1409 self.outer_type_is_public_path = true;
1412 self.at_outer_type = false;
1413 intravisit::walk_ty(self, ty)
1416 // Don't want to recurse into `[, .. expr]`.
1417 fn visit_expr(&mut self, _: &hir::Expr<'_>) {}
1420 impl<'a, 'tcx> Visitor<'tcx> for ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1421 type NestedFilter = nested_filter::All;
1423 /// We want to visit items in the context of their containing
1424 /// module and so forth, so supply a crate for doing a deep walk.
1425 fn nested_visit_map(&mut self) -> Self::Map {
1429 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1431 // Contents of a private mod can be re-exported, so we need
1432 // to check internals.
1433 hir::ItemKind::Mod(_) => {}
1435 // An `extern {}` doesn't introduce a new privacy
1436 // namespace (the contents have their own privacies).
1437 hir::ItemKind::ForeignMod { .. } => {}
1439 hir::ItemKind::Trait(.., bounds, _) => {
1440 if !self.trait_is_public(item.def_id) {
1444 for bound in bounds.iter() {
1445 self.check_generic_bound(bound)
1449 // Impls need some special handling to try to offer useful
1450 // error messages without (too many) false positives
1451 // (i.e., we could just return here to not check them at
1452 // all, or some worse estimation of whether an impl is
1453 // publicly visible).
1454 hir::ItemKind::Impl(ref impl_) => {
1455 // `impl [... for] Private` is never visible.
1456 let self_contains_private;
1457 // `impl [... for] Public<...>`, but not `impl [... for]
1458 // Vec<Public>` or `(Public,)`, etc.
1459 let self_is_public_path;
1461 // Check the properties of the `Self` type:
1463 let mut visitor = ObsoleteCheckTypeForPrivatenessVisitor {
1465 contains_private: false,
1466 at_outer_type: true,
1467 outer_type_is_public_path: false,
1469 visitor.visit_ty(impl_.self_ty);
1470 self_contains_private = visitor.contains_private;
1471 self_is_public_path = visitor.outer_type_is_public_path;
1474 // Miscellaneous info about the impl:
1476 // `true` iff this is `impl Private for ...`.
1477 let not_private_trait = impl_.of_trait.as_ref().map_or(
1478 true, // no trait counts as public trait
1480 if let Some(def_id) = tr.path.res.def_id().as_local() {
1481 self.trait_is_public(def_id)
1483 true // external traits must be public
1488 // `true` iff this is a trait impl or at least one method is public.
1490 // `impl Public { $( fn ...() {} )* }` is not visible.
1492 // This is required over just using the methods' privacy
1493 // directly because we might have `impl<T: Foo<Private>> ...`,
1494 // and we shouldn't warn about the generics if all the methods
1495 // are private (because `T` won't be visible externally).
1496 let trait_or_some_public_method = impl_.of_trait.is_some()
1497 || impl_.items.iter().any(|impl_item_ref| {
1498 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1499 match impl_item.kind {
1500 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..) => {
1501 self.access_levels.is_reachable(impl_item_ref.id.def_id)
1503 hir::ImplItemKind::TyAlias(_) => false,
1507 if !self_contains_private && not_private_trait && trait_or_some_public_method {
1508 intravisit::walk_generics(self, &impl_.generics);
1510 match impl_.of_trait {
1512 for impl_item_ref in impl_.items {
1513 // This is where we choose whether to walk down
1514 // further into the impl to check its items. We
1515 // should only walk into public items so that we
1516 // don't erroneously report errors for private
1517 // types in private items.
1518 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1519 match impl_item.kind {
1520 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..)
1522 .item_is_public(impl_item.def_id, &impl_item.vis) =>
1524 intravisit::walk_impl_item(self, impl_item)
1526 hir::ImplItemKind::TyAlias(..) => {
1527 intravisit::walk_impl_item(self, impl_item)
1534 // Any private types in a trait impl fall into three
1536 // 1. mentioned in the trait definition
1537 // 2. mentioned in the type params/generics
1538 // 3. mentioned in the associated types of the impl
1540 // Those in 1. can only occur if the trait is in
1541 // this crate and will've been warned about on the
1542 // trait definition (there's no need to warn twice
1543 // so we don't check the methods).
1545 // Those in 2. are warned via walk_generics and this
1547 intravisit::walk_path(self, tr.path);
1549 // Those in 3. are warned with this call.
1550 for impl_item_ref in impl_.items {
1551 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1552 if let hir::ImplItemKind::TyAlias(ty) = impl_item.kind {
1558 } else if impl_.of_trait.is_none() && self_is_public_path {
1559 // `impl Public<Private> { ... }`. Any public static
1560 // methods will be visible as `Public::foo`.
1561 let mut found_pub_static = false;
1562 for impl_item_ref in impl_.items {
1563 if self.access_levels.is_reachable(impl_item_ref.id.def_id)
1564 || self.tcx.visibility(impl_item_ref.id.def_id)
1565 == ty::Visibility::Public
1567 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1568 match impl_item_ref.kind {
1569 AssocItemKind::Const => {
1570 found_pub_static = true;
1571 intravisit::walk_impl_item(self, impl_item);
1573 AssocItemKind::Fn { has_self: false } => {
1574 found_pub_static = true;
1575 intravisit::walk_impl_item(self, impl_item);
1581 if found_pub_static {
1582 intravisit::walk_generics(self, &impl_.generics)
1588 // `type ... = ...;` can contain private types, because
1589 // we're introducing a new name.
1590 hir::ItemKind::TyAlias(..) => return,
1592 // Not at all public, so we don't care.
1593 _ if !self.item_is_public(item.def_id, &item.vis) => {
1600 // We've carefully constructed it so that if we're here, then
1601 // any `visit_ty`'s will be called on things that are in
1602 // public signatures, i.e., things that we're interested in for
1604 intravisit::walk_item(self, item);
1607 fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
1608 for param in generics.params {
1609 for bound in param.bounds {
1610 self.check_generic_bound(bound);
1613 for predicate in generics.where_clause.predicates {
1615 hir::WherePredicate::BoundPredicate(bound_pred) => {
1616 for bound in bound_pred.bounds.iter() {
1617 self.check_generic_bound(bound)
1620 hir::WherePredicate::RegionPredicate(_) => {}
1621 hir::WherePredicate::EqPredicate(eq_pred) => {
1622 self.visit_ty(eq_pred.rhs_ty);
1628 fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem<'tcx>) {
1629 if self.access_levels.is_reachable(item.def_id) {
1630 intravisit::walk_foreign_item(self, item)
1634 fn visit_ty(&mut self, t: &'tcx hir::Ty<'tcx>) {
1635 if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = t.kind {
1636 if self.path_is_private_type(path) {
1637 self.old_error_set.insert(t.hir_id);
1640 intravisit::walk_ty(self, t)
1645 v: &'tcx hir::Variant<'tcx>,
1646 g: &'tcx hir::Generics<'tcx>,
1647 item_id: hir::HirId,
1649 if self.access_levels.is_reachable(self.tcx.hir().local_def_id(v.id)) {
1650 self.in_variant = true;
1651 intravisit::walk_variant(self, v, g, item_id);
1652 self.in_variant = false;
1656 fn visit_field_def(&mut self, s: &'tcx hir::FieldDef<'tcx>) {
1657 if s.vis.node.is_pub() || self.in_variant {
1658 intravisit::walk_field_def(self, s);
1662 // We don't need to introspect into these at all: an
1663 // expression/block context can't possibly contain exported things.
1664 // (Making them no-ops stops us from traversing the whole AST without
1665 // having to be super careful about our `walk_...` calls above.)
1666 fn visit_block(&mut self, _: &'tcx hir::Block<'tcx>) {}
1667 fn visit_expr(&mut self, _: &'tcx hir::Expr<'tcx>) {}
1670 ///////////////////////////////////////////////////////////////////////////////
1671 /// SearchInterfaceForPrivateItemsVisitor traverses an item's interface and
1672 /// finds any private components in it.
1673 /// PrivateItemsInPublicInterfacesVisitor ensures there are no private types
1674 /// and traits in public interfaces.
1675 ///////////////////////////////////////////////////////////////////////////////
1677 struct SearchInterfaceForPrivateItemsVisitor<'tcx> {
1679 item_def_id: LocalDefId,
1680 /// The visitor checks that each component type is at least this visible.
1681 required_visibility: ty::Visibility,
1682 has_pub_restricted: bool,
1683 has_old_errors: bool,
1687 impl SearchInterfaceForPrivateItemsVisitor<'_> {
1688 fn generics(&mut self) -> &mut Self {
1689 for param in &self.tcx.generics_of(self.item_def_id).params {
1691 GenericParamDefKind::Lifetime => {}
1692 GenericParamDefKind::Type { has_default, .. } => {
1694 self.visit(self.tcx.type_of(param.def_id));
1697 // FIXME(generic_const_exprs): May want to look inside const here
1698 GenericParamDefKind::Const { .. } => {
1699 self.visit(self.tcx.type_of(param.def_id));
1706 fn predicates(&mut self) -> &mut Self {
1707 // N.B., we use `explicit_predicates_of` and not `predicates_of`
1708 // because we don't want to report privacy errors due to where
1709 // clauses that the compiler inferred. We only want to
1710 // consider the ones that the user wrote. This is important
1711 // for the inferred outlives rules; see
1712 // `src/test/ui/rfc-2093-infer-outlives/privacy.rs`.
1713 self.visit_predicates(self.tcx.explicit_predicates_of(self.item_def_id));
1717 fn bounds(&mut self) -> &mut Self {
1718 self.visit_predicates(ty::GenericPredicates {
1720 predicates: self.tcx.explicit_item_bounds(self.item_def_id),
1725 fn ty(&mut self) -> &mut Self {
1726 self.visit(self.tcx.type_of(self.item_def_id));
1730 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1731 if self.leaks_private_dep(def_id) {
1732 self.tcx.struct_span_lint_hir(
1733 lint::builtin::EXPORTED_PRIVATE_DEPENDENCIES,
1734 self.tcx.hir().local_def_id_to_hir_id(self.item_def_id),
1735 self.tcx.def_span(self.item_def_id.to_def_id()),
1737 lint.build(&format!(
1738 "{} `{}` from private dependency '{}' in public \
1742 self.tcx.crate_name(def_id.krate)
1749 let hir_id = match def_id.as_local() {
1750 Some(def_id) => self.tcx.hir().local_def_id_to_hir_id(def_id),
1751 None => return false,
1754 let vis = self.tcx.visibility(def_id);
1755 if !vis.is_at_least(self.required_visibility, self.tcx) {
1756 let vis_descr = match vis {
1757 ty::Visibility::Public => "public",
1758 ty::Visibility::Invisible => "private",
1759 ty::Visibility::Restricted(vis_def_id) => {
1760 if vis_def_id == self.tcx.parent_module(hir_id).to_def_id() {
1762 } else if vis_def_id.is_top_level_module() {
1769 let make_msg = || format!("{} {} `{}` in public interface", vis_descr, kind, descr);
1770 let span = self.tcx.def_span(self.item_def_id.to_def_id());
1771 if self.has_pub_restricted || self.has_old_errors || self.in_assoc_ty {
1772 let mut err = if kind == "trait" {
1773 struct_span_err!(self.tcx.sess, span, E0445, "{}", make_msg())
1775 struct_span_err!(self.tcx.sess, span, E0446, "{}", make_msg())
1778 self.tcx.sess.source_map().guess_head_span(self.tcx.def_span(def_id));
1779 err.span_label(span, format!("can't leak {} {}", vis_descr, kind));
1780 err.span_label(vis_span, format!("`{}` declared as {}", descr, vis_descr));
1783 let err_code = if kind == "trait" { "E0445" } else { "E0446" };
1784 self.tcx.struct_span_lint_hir(
1785 lint::builtin::PRIVATE_IN_PUBLIC,
1788 |lint| lint.build(&format!("{} (error {})", make_msg(), err_code)).emit(),
1796 /// An item is 'leaked' from a private dependency if all
1797 /// of the following are true:
1798 /// 1. It's contained within a public type
1799 /// 2. It comes from a private crate
1800 fn leaks_private_dep(&self, item_id: DefId) -> bool {
1801 let ret = self.required_visibility.is_public() && self.tcx.is_private_dep(item_id.krate);
1803 tracing::debug!("leaks_private_dep(item_id={:?})={}", item_id, ret);
1808 impl<'tcx> DefIdVisitor<'tcx> for SearchInterfaceForPrivateItemsVisitor<'tcx> {
1809 fn tcx(&self) -> TyCtxt<'tcx> {
1816 descr: &dyn fmt::Display,
1817 ) -> ControlFlow<Self::BreakTy> {
1818 if self.check_def_id(def_id, kind, descr) {
1821 ControlFlow::CONTINUE
1826 struct PrivateItemsInPublicInterfacesVisitor<'tcx> {
1828 has_pub_restricted: bool,
1829 old_error_set_ancestry: LocalDefIdSet,
1832 impl<'tcx> PrivateItemsInPublicInterfacesVisitor<'tcx> {
1836 required_visibility: ty::Visibility,
1837 ) -> SearchInterfaceForPrivateItemsVisitor<'tcx> {
1838 SearchInterfaceForPrivateItemsVisitor {
1840 item_def_id: def_id,
1841 required_visibility,
1842 has_pub_restricted: self.has_pub_restricted,
1843 has_old_errors: self.old_error_set_ancestry.contains(&def_id),
1848 fn check_assoc_item(
1851 assoc_item_kind: AssocItemKind,
1852 defaultness: hir::Defaultness,
1853 vis: ty::Visibility,
1855 let mut check = self.check(def_id, vis);
1857 let (check_ty, is_assoc_ty) = match assoc_item_kind {
1858 AssocItemKind::Const | AssocItemKind::Fn { .. } => (true, false),
1859 AssocItemKind::Type => (defaultness.has_value(), true),
1861 check.in_assoc_ty = is_assoc_ty;
1862 check.generics().predicates();
1869 impl<'tcx> Visitor<'tcx> for PrivateItemsInPublicInterfacesVisitor<'tcx> {
1870 type NestedFilter = nested_filter::OnlyBodies;
1872 fn nested_visit_map(&mut self) -> Self::Map {
1876 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1878 let item_visibility = tcx.visibility(item.def_id);
1881 // Crates are always public.
1882 hir::ItemKind::ExternCrate(..) => {}
1883 // All nested items are checked by `visit_item`.
1884 hir::ItemKind::Mod(..) => {}
1885 // Checked in resolve.
1886 hir::ItemKind::Use(..) => {}
1888 hir::ItemKind::Macro(..) | hir::ItemKind::GlobalAsm(..) => {}
1889 // Subitems of these items have inherited publicity.
1890 hir::ItemKind::Const(..)
1891 | hir::ItemKind::Static(..)
1892 | hir::ItemKind::Fn(..)
1893 | hir::ItemKind::TyAlias(..) => {
1894 self.check(item.def_id, item_visibility).generics().predicates().ty();
1896 hir::ItemKind::OpaqueTy(..) => {
1897 // `ty()` for opaque types is the underlying type,
1898 // it's not a part of interface, so we skip it.
1899 self.check(item.def_id, item_visibility).generics().bounds();
1901 hir::ItemKind::Trait(.., trait_item_refs) => {
1902 self.check(item.def_id, item_visibility).generics().predicates();
1904 for trait_item_ref in trait_item_refs {
1905 self.check_assoc_item(
1906 trait_item_ref.id.def_id,
1907 trait_item_ref.kind,
1908 trait_item_ref.defaultness,
1912 if let AssocItemKind::Type = trait_item_ref.kind {
1913 self.check(trait_item_ref.id.def_id, item_visibility).bounds();
1917 hir::ItemKind::TraitAlias(..) => {
1918 self.check(item.def_id, item_visibility).generics().predicates();
1920 hir::ItemKind::Enum(ref def, _) => {
1921 self.check(item.def_id, item_visibility).generics().predicates();
1923 for variant in def.variants {
1924 for field in variant.data.fields() {
1925 self.check(self.tcx.hir().local_def_id(field.hir_id), item_visibility).ty();
1929 // Subitems of foreign modules have their own publicity.
1930 hir::ItemKind::ForeignMod { items, .. } => {
1931 for foreign_item in items {
1932 let vis = tcx.visibility(foreign_item.id.def_id);
1933 self.check(foreign_item.id.def_id, vis).generics().predicates().ty();
1936 // Subitems of structs and unions have their own publicity.
1937 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
1938 self.check(item.def_id, item_visibility).generics().predicates();
1940 for field in struct_def.fields() {
1941 let def_id = tcx.hir().local_def_id(field.hir_id);
1942 let field_visibility = tcx.visibility(def_id);
1943 self.check(def_id, min(item_visibility, field_visibility, tcx)).ty();
1946 // An inherent impl is public when its type is public
1947 // Subitems of inherent impls have their own publicity.
1948 // A trait impl is public when both its type and its trait are public
1949 // Subitems of trait impls have inherited publicity.
1950 hir::ItemKind::Impl(ref impl_) => {
1951 let impl_vis = ty::Visibility::of_impl(item.def_id, tcx, &Default::default());
1952 // check that private components do not appear in the generics or predicates of inherent impls
1953 // this check is intentionally NOT performed for impls of traits, per #90586
1954 if impl_.of_trait.is_none() {
1955 self.check(item.def_id, impl_vis).generics().predicates();
1957 for impl_item_ref in impl_.items {
1958 let impl_item_vis = if impl_.of_trait.is_none() {
1959 min(tcx.visibility(impl_item_ref.id.def_id), impl_vis, tcx)
1963 self.check_assoc_item(
1964 impl_item_ref.id.def_id,
1966 impl_item_ref.defaultness,
1975 pub fn provide(providers: &mut Providers) {
1976 *providers = Providers {
1978 privacy_access_levels,
1979 check_private_in_public,
1985 fn visibility(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Visibility {
1986 let def_id = def_id.expect_local();
1987 match tcx.resolutions(()).visibilities.get(&def_id) {
1990 let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
1991 match tcx.hir().get(hir_id) {
1992 // Unique types created for closures participate in type privacy checking.
1993 // They have visibilities inherited from the module they are defined in.
1994 Node::Expr(hir::Expr { kind: hir::ExprKind::Closure(..), .. }) => {
1995 ty::Visibility::Restricted(tcx.parent_module(hir_id).to_def_id())
1997 // - AST lowering may clone `use` items and the clones don't
1998 // get their entries in the resolver's visibility table.
1999 // - AST lowering also creates opaque type items with inherited visibilies.
2000 // Visibility on them should have no effect, but to avoid the visibility
2001 // query failing on some items, we provide it for opaque types as well.
2002 Node::Item(hir::Item {
2004 kind: hir::ItemKind::Use(..) | hir::ItemKind::OpaqueTy(..),
2006 }) => ty::Visibility::from_hir(vis, hir_id, tcx),
2007 // Visibilities of trait impl items are inherited from their traits
2008 // and are not filled in resolve.
2009 Node::ImplItem(impl_item) => {
2010 match tcx.hir().get_by_def_id(tcx.hir().get_parent_item(hir_id)) {
2011 Node::Item(hir::Item {
2012 kind: hir::ItemKind::Impl(hir::Impl { of_trait: Some(tr), .. }),
2014 }) => tr.path.res.opt_def_id().map_or_else(
2016 tcx.sess.delay_span_bug(tr.path.span, "trait without a def-id");
2017 ty::Visibility::Public
2019 |def_id| tcx.visibility(def_id),
2021 _ => span_bug!(impl_item.span, "the parent is not a trait impl"),
2025 tcx.def_span(def_id),
2026 "visibility table unexpectedly missing a def-id: {:?}",
2034 fn check_mod_privacy(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
2035 // Check privacy of names not checked in previous compilation stages.
2037 NamePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id };
2038 let (module, span, hir_id) = tcx.hir().get_module(module_def_id);
2040 intravisit::walk_mod(&mut visitor, module, hir_id);
2042 // Check privacy of explicitly written types and traits as well as
2043 // inferred types of expressions and patterns.
2045 TypePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id, span };
2046 intravisit::walk_mod(&mut visitor, module, hir_id);
2049 fn privacy_access_levels(tcx: TyCtxt<'_>, (): ()) -> &AccessLevels {
2050 // Build up a set of all exported items in the AST. This is a set of all
2051 // items which are reachable from external crates based on visibility.
2052 let mut visitor = EmbargoVisitor {
2054 access_levels: tcx.resolutions(()).access_levels.clone(),
2055 macro_reachable: Default::default(),
2056 prev_level: Some(AccessLevel::Public),
2061 tcx.hir().walk_toplevel_module(&mut visitor);
2062 if visitor.changed {
2063 visitor.changed = false;
2069 tcx.arena.alloc(visitor.access_levels)
2072 fn check_private_in_public(tcx: TyCtxt<'_>, (): ()) {
2073 let access_levels = tcx.privacy_access_levels(());
2075 let mut visitor = ObsoleteVisiblePrivateTypesVisitor {
2079 old_error_set: Default::default(),
2081 tcx.hir().walk_toplevel_module(&mut visitor);
2083 let has_pub_restricted = {
2084 let mut pub_restricted_visitor = PubRestrictedVisitor { tcx, has_pub_restricted: false };
2085 tcx.hir().walk_toplevel_module(&mut pub_restricted_visitor);
2086 pub_restricted_visitor.has_pub_restricted
2089 let mut old_error_set_ancestry = HirIdSet::default();
2090 for mut id in visitor.old_error_set.iter().copied() {
2092 if !old_error_set_ancestry.insert(id) {
2095 let parent = tcx.hir().get_parent_node(id);
2103 // Check for private types and traits in public interfaces.
2104 let mut visitor = PrivateItemsInPublicInterfacesVisitor {
2107 // Only definition IDs are ever searched in `old_error_set_ancestry`,
2108 // so we can filter away all non-definition IDs at this point.
2109 old_error_set_ancestry: old_error_set_ancestry
2111 .filter_map(|hir_id| tcx.hir().opt_local_def_id(hir_id))
2114 tcx.hir().visit_all_item_likes(&mut DeepVisitor::new(&mut visitor));