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"]
8 use rustc_ast::MacroDef;
9 use rustc_attr as attr;
10 use rustc_data_structures::fx::FxHashSet;
11 use rustc_errors::struct_span_err;
13 use rustc_hir::def::{DefKind, Res};
14 use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdSet, CRATE_DEF_ID};
15 use rustc_hir::intravisit::{self, DeepVisitor, NestedVisitorMap, Visitor};
16 use rustc_hir::{AssocItemKind, HirIdSet, Node, PatKind};
17 use rustc_middle::bug;
18 use rustc_middle::hir::map::Map;
19 use rustc_middle::middle::privacy::{AccessLevel, AccessLevels};
20 use rustc_middle::span_bug;
21 use rustc_middle::thir::abstract_const::Node as ACNode;
22 use rustc_middle::ty::fold::TypeVisitor;
23 use rustc_middle::ty::query::Providers;
24 use rustc_middle::ty::subst::InternalSubsts;
25 use rustc_middle::ty::{self, Const, GenericParamDefKind, TraitRef, Ty, TyCtxt, TypeFoldable};
26 use rustc_session::lint;
27 use rustc_span::hygiene::Transparency;
28 use rustc_span::symbol::{kw, Ident};
30 use rustc_trait_selection::traits::const_evaluatable::{self, AbstractConst};
32 use std::marker::PhantomData;
33 use std::ops::ControlFlow;
34 use std::{cmp, fmt, mem};
36 ////////////////////////////////////////////////////////////////////////////////
37 /// Generic infrastructure used to implement specific visitors below.
38 ////////////////////////////////////////////////////////////////////////////////
40 /// Implemented to visit all `DefId`s in a type.
41 /// Visiting `DefId`s is useful because visibilities and reachabilities are attached to them.
42 /// The idea is to visit "all components of a type", as documented in
43 /// <https://github.com/rust-lang/rfcs/blob/master/text/2145-type-privacy.md#how-to-determine-visibility-of-a-type>.
44 /// The default type visitor (`TypeVisitor`) does most of the job, but it has some shortcomings.
45 /// First, it doesn't have overridable `fn visit_trait_ref`, so we have to catch trait `DefId`s
46 /// manually. Second, it doesn't visit some type components like signatures of fn types, or traits
47 /// in `impl Trait`, see individual comments in `DefIdVisitorSkeleton::visit_ty`.
48 trait DefIdVisitor<'tcx> {
51 fn tcx(&self) -> TyCtxt<'tcx>;
52 fn shallow(&self) -> bool {
55 fn skip_assoc_tys(&self) -> bool {
62 descr: &dyn fmt::Display,
63 ) -> ControlFlow<Self::BreakTy>;
65 /// Not overridden, but used to actually visit types and traits.
66 fn skeleton(&mut self) -> DefIdVisitorSkeleton<'_, 'tcx, Self> {
67 DefIdVisitorSkeleton {
69 visited_opaque_tys: Default::default(),
70 dummy: Default::default(),
73 fn visit(&mut self, ty_fragment: impl TypeFoldable<'tcx>) -> ControlFlow<Self::BreakTy> {
74 ty_fragment.visit_with(&mut self.skeleton())
76 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> ControlFlow<Self::BreakTy> {
77 self.skeleton().visit_trait(trait_ref)
79 fn visit_projection_ty(
81 projection: ty::ProjectionTy<'tcx>,
82 ) -> ControlFlow<Self::BreakTy> {
83 self.skeleton().visit_projection_ty(projection)
87 predicates: ty::GenericPredicates<'tcx>,
88 ) -> ControlFlow<Self::BreakTy> {
89 self.skeleton().visit_predicates(predicates)
93 struct DefIdVisitorSkeleton<'v, 'tcx, V: ?Sized> {
94 def_id_visitor: &'v mut V,
95 visited_opaque_tys: FxHashSet<DefId>,
96 dummy: PhantomData<TyCtxt<'tcx>>,
99 impl<'tcx, V> DefIdVisitorSkeleton<'_, 'tcx, V>
101 V: DefIdVisitor<'tcx> + ?Sized,
103 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> ControlFlow<V::BreakTy> {
104 let TraitRef { def_id, substs } = trait_ref;
105 self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref.print_only_trait_path())?;
106 if self.def_id_visitor.shallow() { ControlFlow::CONTINUE } else { substs.visit_with(self) }
109 fn visit_projection_ty(
111 projection: ty::ProjectionTy<'tcx>,
112 ) -> ControlFlow<V::BreakTy> {
113 let (trait_ref, assoc_substs) =
114 projection.trait_ref_and_own_substs(self.def_id_visitor.tcx());
115 self.visit_trait(trait_ref)?;
116 if self.def_id_visitor.shallow() {
117 ControlFlow::CONTINUE
119 assoc_substs.iter().try_for_each(|subst| subst.visit_with(self))
123 fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> ControlFlow<V::BreakTy> {
124 match predicate.kind().skip_binder() {
125 ty::PredicateKind::Trait(ty::TraitPredicate {
129 }) => self.visit_trait(trait_ref),
130 ty::PredicateKind::Projection(ty::ProjectionPredicate { projection_ty, term }) => {
132 ty::Term::Ty(ty) => ty.visit_with(self)?,
133 ty::Term::Const(ct) => ct.visit_with(self)?,
135 self.visit_projection_ty(projection_ty)
137 ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(ty, _region)) => {
140 ty::PredicateKind::RegionOutlives(..) => ControlFlow::CONTINUE,
141 ty::PredicateKind::ConstEvaluatable(uv)
142 if self.def_id_visitor.tcx().features().generic_const_exprs =>
144 let tcx = self.def_id_visitor.tcx();
145 if let Ok(Some(ct)) = AbstractConst::new(tcx, uv) {
146 self.visit_abstract_const_expr(tcx, ct)?;
148 ControlFlow::CONTINUE
150 _ => bug!("unexpected predicate: {:?}", predicate),
154 fn visit_abstract_const_expr(
157 ct: AbstractConst<'tcx>,
158 ) -> ControlFlow<V::BreakTy> {
159 const_evaluatable::walk_abstract_const(tcx, ct, |node| match node.root(tcx) {
160 ACNode::Leaf(leaf) => self.visit_const(leaf),
161 ACNode::Cast(_, _, ty) => self.visit_ty(ty),
162 ACNode::Binop(..) | ACNode::UnaryOp(..) | ACNode::FunctionCall(_, _) => {
163 ControlFlow::CONTINUE
170 predicates: ty::GenericPredicates<'tcx>,
171 ) -> ControlFlow<V::BreakTy> {
172 let ty::GenericPredicates { parent: _, predicates } = predicates;
173 predicates.iter().try_for_each(|&(predicate, _span)| self.visit_predicate(predicate))
177 impl<'tcx, V> TypeVisitor<'tcx> for DefIdVisitorSkeleton<'_, 'tcx, V>
179 V: DefIdVisitor<'tcx> + ?Sized,
181 type BreakTy = V::BreakTy;
183 fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<V::BreakTy> {
184 let tcx = self.def_id_visitor.tcx();
185 // InternalSubsts are not visited here because they are visited below in `super_visit_with`.
187 ty::Adt(&ty::AdtDef { did: def_id, .. }, ..)
188 | ty::Foreign(def_id)
189 | ty::FnDef(def_id, ..)
190 | ty::Closure(def_id, ..)
191 | ty::Generator(def_id, ..) => {
192 self.def_id_visitor.visit_def_id(def_id, "type", &ty)?;
193 if self.def_id_visitor.shallow() {
194 return ControlFlow::CONTINUE;
196 // Default type visitor doesn't visit signatures of fn types.
197 // Something like `fn() -> Priv {my_func}` is considered a private type even if
198 // `my_func` is public, so we need to visit signatures.
199 if let ty::FnDef(..) = ty.kind() {
200 tcx.fn_sig(def_id).visit_with(self)?;
202 // Inherent static methods don't have self type in substs.
203 // Something like `fn() {my_method}` type of the method
204 // `impl Pub<Priv> { pub fn my_method() {} }` is considered a private type,
205 // so we need to visit the self type additionally.
206 if let Some(assoc_item) = tcx.opt_associated_item(def_id) {
207 if let ty::ImplContainer(impl_def_id) = assoc_item.container {
208 tcx.type_of(impl_def_id).visit_with(self)?;
212 ty::Projection(proj) => {
213 if self.def_id_visitor.skip_assoc_tys() {
214 // Visitors searching for minimal visibility/reachability want to
215 // conservatively approximate associated types like `<Type as Trait>::Alias`
216 // as visible/reachable even if both `Type` and `Trait` are private.
217 // Ideally, associated types should be substituted in the same way as
218 // free type aliases, but this isn't done yet.
219 return ControlFlow::CONTINUE;
221 // This will also visit substs if necessary, so we don't need to recurse.
222 return self.visit_projection_ty(proj);
224 ty::Dynamic(predicates, ..) => {
225 // All traits in the list are considered the "primary" part of the type
226 // and are visited by shallow visitors.
227 for predicate in predicates {
228 let trait_ref = match predicate.skip_binder() {
229 ty::ExistentialPredicate::Trait(trait_ref) => trait_ref,
230 ty::ExistentialPredicate::Projection(proj) => proj.trait_ref(tcx),
231 ty::ExistentialPredicate::AutoTrait(def_id) => {
232 ty::ExistentialTraitRef { def_id, substs: InternalSubsts::empty() }
235 let ty::ExistentialTraitRef { def_id, substs: _ } = trait_ref;
236 self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref)?;
239 ty::Opaque(def_id, ..) => {
240 // Skip repeated `Opaque`s to avoid infinite recursion.
241 if self.visited_opaque_tys.insert(def_id) {
242 // The intent is to treat `impl Trait1 + Trait2` identically to
243 // `dyn Trait1 + Trait2`. Therefore we ignore def-id of the opaque type itself
244 // (it either has no visibility, or its visibility is insignificant, like
245 // visibilities of type aliases) and recurse into bounds instead to go
246 // through the trait list (default type visitor doesn't visit those traits).
247 // All traits in the list are considered the "primary" part of the type
248 // and are visited by shallow visitors.
249 self.visit_predicates(ty::GenericPredicates {
251 predicates: tcx.explicit_item_bounds(def_id),
255 // These types don't have their own def-ids (but may have subcomponents
256 // with def-ids that should be visited recursively).
272 | ty::GeneratorWitness(..) => {}
273 ty::Bound(..) | ty::Placeholder(..) | ty::Infer(..) => {
274 bug!("unexpected type: {:?}", ty)
278 if self.def_id_visitor.shallow() {
279 ControlFlow::CONTINUE
281 ty.super_visit_with(self)
285 fn visit_const(&mut self, c: &'tcx Const<'tcx>) -> ControlFlow<Self::BreakTy> {
286 self.visit_ty(c.ty)?;
287 let tcx = self.def_id_visitor.tcx();
288 if let Ok(Some(ct)) = AbstractConst::from_const(tcx, c) {
289 self.visit_abstract_const_expr(tcx, ct)?;
291 ControlFlow::CONTINUE
295 fn min(vis1: ty::Visibility, vis2: ty::Visibility, tcx: TyCtxt<'_>) -> ty::Visibility {
296 if vis1.is_at_least(vis2, tcx) { vis2 } else { vis1 }
299 ////////////////////////////////////////////////////////////////////////////////
300 /// Visitor used to determine if pub(restricted) is used anywhere in the crate.
302 /// This is done so that `private_in_public` warnings can be turned into hard errors
303 /// in crates that have been updated to use pub(restricted).
304 ////////////////////////////////////////////////////////////////////////////////
305 struct PubRestrictedVisitor<'tcx> {
307 has_pub_restricted: bool,
310 impl<'tcx> Visitor<'tcx> for PubRestrictedVisitor<'tcx> {
311 type Map = Map<'tcx>;
313 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
314 NestedVisitorMap::All(self.tcx.hir())
316 fn visit_vis(&mut self, vis: &'tcx hir::Visibility<'tcx>) {
317 self.has_pub_restricted = self.has_pub_restricted || vis.node.is_pub_restricted();
321 ////////////////////////////////////////////////////////////////////////////////
322 /// Visitor used to determine impl visibility and reachability.
323 ////////////////////////////////////////////////////////////////////////////////
325 struct FindMin<'a, 'tcx, VL: VisibilityLike> {
327 access_levels: &'a AccessLevels,
331 impl<'a, 'tcx, VL: VisibilityLike> DefIdVisitor<'tcx> for FindMin<'a, 'tcx, VL> {
332 fn tcx(&self) -> TyCtxt<'tcx> {
335 fn shallow(&self) -> bool {
338 fn skip_assoc_tys(&self) -> bool {
345 _descr: &dyn fmt::Display,
346 ) -> ControlFlow<Self::BreakTy> {
347 self.min = VL::new_min(self, def_id);
348 ControlFlow::CONTINUE
352 trait VisibilityLike: Sized {
354 const SHALLOW: bool = false;
355 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self;
357 // Returns an over-approximation (`skip_assoc_tys` = true) of visibility due to
358 // associated types for which we can't determine visibility precisely.
359 fn of_impl(def_id: LocalDefId, tcx: TyCtxt<'_>, access_levels: &AccessLevels) -> Self {
360 let mut find = FindMin { tcx, access_levels, min: Self::MAX };
361 find.visit(tcx.type_of(def_id));
362 if let Some(trait_ref) = tcx.impl_trait_ref(def_id) {
363 find.visit_trait(trait_ref);
368 impl VisibilityLike for ty::Visibility {
369 const MAX: Self = ty::Visibility::Public;
370 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
371 min(find.tcx.visibility(def_id), find.min, find.tcx)
374 impl VisibilityLike for Option<AccessLevel> {
375 const MAX: Self = Some(AccessLevel::Public);
376 // Type inference is very smart sometimes.
377 // It can make an impl reachable even some components of its type or trait are unreachable.
378 // E.g. methods of `impl ReachableTrait<UnreachableTy> for ReachableTy<UnreachableTy> { ... }`
379 // can be usable from other crates (#57264). So we skip substs when calculating reachability
380 // and consider an impl reachable if its "shallow" type and trait are reachable.
382 // The assumption we make here is that type-inference won't let you use an impl without knowing
383 // both "shallow" version of its self type and "shallow" version of its trait if it exists
384 // (which require reaching the `DefId`s in them).
385 const SHALLOW: bool = true;
386 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
388 if let Some(def_id) = def_id.as_local() {
389 find.access_levels.map.get(&def_id).copied()
398 ////////////////////////////////////////////////////////////////////////////////
399 /// The embargo visitor, used to determine the exports of the AST.
400 ////////////////////////////////////////////////////////////////////////////////
402 struct EmbargoVisitor<'tcx> {
405 /// Accessibility levels for reachable nodes.
406 access_levels: AccessLevels,
407 /// A set of pairs corresponding to modules, where the first module is
408 /// reachable via a macro that's defined in the second module. This cannot
409 /// be represented as reachable because it can't handle the following case:
411 /// pub mod n { // Should be `Public`
412 /// pub(crate) mod p { // Should *not* be accessible
413 /// pub fn f() -> i32 { 12 } // Must be `Reachable`
419 macro_reachable: FxHashSet<(LocalDefId, LocalDefId)>,
420 /// Previous accessibility level; `None` means unreachable.
421 prev_level: Option<AccessLevel>,
422 /// Has something changed in the level map?
426 struct ReachEverythingInTheInterfaceVisitor<'a, 'tcx> {
427 access_level: Option<AccessLevel>,
428 item_def_id: LocalDefId,
429 ev: &'a mut EmbargoVisitor<'tcx>,
432 impl<'tcx> EmbargoVisitor<'tcx> {
433 fn get(&self, def_id: LocalDefId) -> Option<AccessLevel> {
434 self.access_levels.map.get(&def_id).copied()
437 fn update_with_hir_id(
440 level: Option<AccessLevel>,
441 ) -> Option<AccessLevel> {
442 let def_id = self.tcx.hir().local_def_id(hir_id);
443 self.update(def_id, level)
446 /// Updates node level and returns the updated level.
447 fn update(&mut self, def_id: LocalDefId, level: Option<AccessLevel>) -> Option<AccessLevel> {
448 let old_level = self.get(def_id);
449 // Accessibility levels can only grow.
450 if level > old_level {
451 self.access_levels.map.insert(def_id, level.unwrap());
462 access_level: Option<AccessLevel>,
463 ) -> ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
464 ReachEverythingInTheInterfaceVisitor {
465 access_level: cmp::min(access_level, Some(AccessLevel::Reachable)),
471 // We have to make sure that the items that macros might reference
472 // are reachable, since they might be exported transitively.
473 fn update_reachability_from_macro(&mut self, local_def_id: LocalDefId, md: &MacroDef) {
474 // Non-opaque macros cannot make other items more accessible than they already are.
476 let hir_id = self.tcx.hir().local_def_id_to_hir_id(local_def_id);
477 let attrs = self.tcx.hir().attrs(hir_id);
478 if attr::find_transparency(attrs, md.macro_rules).0 != Transparency::Opaque {
482 let item_def_id = local_def_id.to_def_id();
483 let macro_module_def_id =
484 ty::DefIdTree::parent(self.tcx, item_def_id).unwrap().expect_local();
485 if self.tcx.hir().opt_def_kind(macro_module_def_id) != Some(DefKind::Mod) {
486 // The macro's parent doesn't correspond to a `mod`, return early (#63164, #65252).
490 if self.get(local_def_id).is_none() {
494 // Since we are starting from an externally visible module,
495 // all the parents in the loop below are also guaranteed to be modules.
496 let mut module_def_id = macro_module_def_id;
498 let changed_reachability =
499 self.update_macro_reachable(module_def_id, macro_module_def_id);
500 if changed_reachability || module_def_id == CRATE_DEF_ID {
504 ty::DefIdTree::parent(self.tcx, module_def_id.to_def_id()).unwrap().expect_local();
508 /// Updates the item as being reachable through a macro defined in the given
509 /// module. Returns `true` if the level has changed.
510 fn update_macro_reachable(
512 module_def_id: LocalDefId,
513 defining_mod: LocalDefId,
515 if self.macro_reachable.insert((module_def_id, defining_mod)) {
516 self.update_macro_reachable_mod(module_def_id, defining_mod);
523 fn update_macro_reachable_mod(&mut self, module_def_id: LocalDefId, defining_mod: LocalDefId) {
524 let module = self.tcx.hir().get_module(module_def_id).0;
525 for item_id in module.item_ids {
526 let def_kind = self.tcx.def_kind(item_id.def_id);
527 let vis = self.tcx.visibility(item_id.def_id);
528 self.update_macro_reachable_def(item_id.def_id, def_kind, vis, defining_mod);
530 if let Some(exports) = self.tcx.module_reexports(module_def_id) {
531 for export in exports {
532 if export.vis.is_accessible_from(defining_mod.to_def_id(), self.tcx) {
533 if let Res::Def(def_kind, def_id) = export.res {
534 if let Some(def_id) = def_id.as_local() {
535 let vis = self.tcx.visibility(def_id.to_def_id());
536 self.update_macro_reachable_def(def_id, def_kind, vis, defining_mod);
544 fn update_macro_reachable_def(
551 let level = Some(AccessLevel::Reachable);
553 self.update(def_id, level);
556 // No type privacy, so can be directly marked as reachable.
557 DefKind::Const | DefKind::Static | DefKind::TraitAlias | DefKind::TyAlias => {
558 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
559 self.update(def_id, level);
563 // Hygine isn't really implemented for `macro_rules!` macros at the
564 // moment. Accordingly, marking them as reachable is unwise. `macro` macros
565 // have normal hygine, so we can treat them like other items without type
566 // privacy and mark them reachable.
567 DefKind::Macro(_) => {
568 let item = self.tcx.hir().expect_item(def_id);
569 if let hir::ItemKind::Macro(MacroDef { macro_rules: false, .. }) = item.kind {
570 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
571 self.update(def_id, level);
576 // We can't use a module name as the final segment of a path, except
577 // in use statements. Since re-export checking doesn't consider
578 // hygiene these don't need to be marked reachable. The contents of
579 // the module, however may be reachable.
581 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
582 self.update_macro_reachable(def_id, module);
586 DefKind::Struct | DefKind::Union => {
587 // While structs and unions have type privacy, their fields do not.
589 let item = self.tcx.hir().expect_item(def_id);
590 if let hir::ItemKind::Struct(ref struct_def, _)
591 | hir::ItemKind::Union(ref struct_def, _) = item.kind
593 for field in struct_def.fields() {
594 let def_id = self.tcx.hir().local_def_id(field.hir_id);
595 let field_vis = self.tcx.visibility(def_id);
596 if field_vis.is_accessible_from(module.to_def_id(), self.tcx) {
597 self.reach(def_id, level).ty();
601 bug!("item {:?} with DefKind {:?}", item, def_kind);
606 // These have type privacy, so are not reachable unless they're
607 // public, or are not namespaced at all.
610 | DefKind::ConstParam
611 | DefKind::Ctor(_, _)
620 | DefKind::LifetimeParam
621 | DefKind::ExternCrate
623 | DefKind::ForeignMod
625 | DefKind::InlineConst
630 | DefKind::Generator => (),
635 impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
636 type Map = Map<'tcx>;
638 /// We want to visit items in the context of their containing
639 /// module and so forth, so supply a crate for doing a deep walk.
640 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
641 NestedVisitorMap::All(self.tcx.hir())
644 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
645 let item_level = match item.kind {
646 hir::ItemKind::Impl { .. } => {
648 Option::<AccessLevel>::of_impl(item.def_id, self.tcx, &self.access_levels);
649 self.update(item.def_id, impl_level)
651 _ => self.get(item.def_id),
654 // Update levels of nested things.
656 hir::ItemKind::Enum(ref def, _) => {
657 for variant in def.variants {
658 let variant_level = self.update_with_hir_id(variant.id, item_level);
659 if let Some(ctor_hir_id) = variant.data.ctor_hir_id() {
660 self.update_with_hir_id(ctor_hir_id, item_level);
662 for field in variant.data.fields() {
663 self.update_with_hir_id(field.hir_id, variant_level);
667 hir::ItemKind::Impl(ref impl_) => {
668 for impl_item_ref in impl_.items {
669 if impl_.of_trait.is_some()
670 || self.tcx.visibility(impl_item_ref.id.def_id) == ty::Visibility::Public
672 self.update(impl_item_ref.id.def_id, item_level);
676 hir::ItemKind::Trait(.., trait_item_refs) => {
677 for trait_item_ref in trait_item_refs {
678 self.update(trait_item_ref.id.def_id, item_level);
681 hir::ItemKind::Struct(ref def, _) | hir::ItemKind::Union(ref def, _) => {
682 if let Some(ctor_hir_id) = def.ctor_hir_id() {
683 self.update_with_hir_id(ctor_hir_id, item_level);
685 for field in def.fields() {
686 if field.vis.node.is_pub() {
687 self.update_with_hir_id(field.hir_id, item_level);
691 hir::ItemKind::Macro(ref macro_def) => {
692 self.update_reachability_from_macro(item.def_id, macro_def);
694 hir::ItemKind::ForeignMod { items, .. } => {
695 for foreign_item in items {
696 if self.tcx.visibility(foreign_item.id.def_id) == ty::Visibility::Public {
697 self.update(foreign_item.id.def_id, item_level);
702 hir::ItemKind::OpaqueTy(..)
703 | hir::ItemKind::Use(..)
704 | hir::ItemKind::Static(..)
705 | hir::ItemKind::Const(..)
706 | hir::ItemKind::GlobalAsm(..)
707 | hir::ItemKind::TyAlias(..)
708 | hir::ItemKind::Mod(..)
709 | hir::ItemKind::TraitAlias(..)
710 | hir::ItemKind::Fn(..)
711 | hir::ItemKind::ExternCrate(..) => {}
714 // Mark all items in interfaces of reachable items as reachable.
716 // The interface is empty.
717 hir::ItemKind::Macro(..) | hir::ItemKind::ExternCrate(..) => {}
718 // All nested items are checked by `visit_item`.
719 hir::ItemKind::Mod(..) => {}
720 // Handled in the access level of in rustc_resolve
721 hir::ItemKind::Use(..) => {}
722 // The interface is empty.
723 hir::ItemKind::GlobalAsm(..) => {}
724 hir::ItemKind::OpaqueTy(..) => {
725 // HACK(jynelson): trying to infer the type of `impl trait` breaks `async-std` (and `pub async fn` in general)
726 // Since rustdoc never needs to do codegen and doesn't care about link-time reachability,
727 // mark this as unreachable.
728 // See https://github.com/rust-lang/rust/issues/75100
729 if !self.tcx.sess.opts.actually_rustdoc {
730 // FIXME: This is some serious pessimization intended to workaround deficiencies
731 // in the reachability pass (`middle/reachable.rs`). Types are marked as link-time
732 // reachable if they are returned via `impl Trait`, even from private functions.
734 cmp::max(item_level, Some(AccessLevel::ReachableFromImplTrait));
735 self.reach(item.def_id, exist_level).generics().predicates().ty();
739 hir::ItemKind::Const(..)
740 | hir::ItemKind::Static(..)
741 | hir::ItemKind::Fn(..)
742 | hir::ItemKind::TyAlias(..) => {
743 if item_level.is_some() {
744 self.reach(item.def_id, item_level).generics().predicates().ty();
747 hir::ItemKind::Trait(.., trait_item_refs) => {
748 if item_level.is_some() {
749 self.reach(item.def_id, item_level).generics().predicates();
751 for trait_item_ref in trait_item_refs {
752 let mut reach = self.reach(trait_item_ref.id.def_id, item_level);
753 reach.generics().predicates();
755 if trait_item_ref.kind == AssocItemKind::Type
756 && !trait_item_ref.defaultness.has_value()
765 hir::ItemKind::TraitAlias(..) => {
766 if item_level.is_some() {
767 self.reach(item.def_id, item_level).generics().predicates();
770 // Visit everything except for private impl items.
771 hir::ItemKind::Impl(ref impl_) => {
772 if item_level.is_some() {
773 self.reach(item.def_id, item_level).generics().predicates().ty().trait_ref();
775 for impl_item_ref in impl_.items {
776 let impl_item_level = self.get(impl_item_ref.id.def_id);
777 if impl_item_level.is_some() {
778 self.reach(impl_item_ref.id.def_id, impl_item_level)
787 // Visit everything, but enum variants have their own levels.
788 hir::ItemKind::Enum(ref def, _) => {
789 if item_level.is_some() {
790 self.reach(item.def_id, item_level).generics().predicates();
792 for variant in def.variants {
793 let variant_level = self.get(self.tcx.hir().local_def_id(variant.id));
794 if variant_level.is_some() {
795 for field in variant.data.fields() {
796 self.reach(self.tcx.hir().local_def_id(field.hir_id), variant_level)
799 // Corner case: if the variant is reachable, but its
800 // enum is not, make the enum reachable as well.
801 self.update(item.def_id, variant_level);
805 // Visit everything, but foreign items have their own levels.
806 hir::ItemKind::ForeignMod { items, .. } => {
807 for foreign_item in items {
808 let foreign_item_level = self.get(foreign_item.id.def_id);
809 if foreign_item_level.is_some() {
810 self.reach(foreign_item.id.def_id, foreign_item_level)
817 // Visit everything except for private fields.
818 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
819 if item_level.is_some() {
820 self.reach(item.def_id, item_level).generics().predicates();
821 for field in struct_def.fields() {
822 let def_id = self.tcx.hir().local_def_id(field.hir_id);
823 let field_level = self.get(def_id);
824 if field_level.is_some() {
825 self.reach(def_id, field_level).ty();
832 let orig_level = mem::replace(&mut self.prev_level, item_level);
833 intravisit::walk_item(self, item);
834 self.prev_level = orig_level;
837 fn visit_block(&mut self, b: &'tcx hir::Block<'tcx>) {
838 // Blocks can have public items, for example impls, but they always
839 // start as completely private regardless of publicity of a function,
840 // constant, type, field, etc., in which this block resides.
841 let orig_level = mem::replace(&mut self.prev_level, None);
842 intravisit::walk_block(self, b);
843 self.prev_level = orig_level;
847 impl ReachEverythingInTheInterfaceVisitor<'_, '_> {
848 fn generics(&mut self) -> &mut Self {
849 for param in &self.ev.tcx.generics_of(self.item_def_id).params {
851 GenericParamDefKind::Lifetime => {}
852 GenericParamDefKind::Type { has_default, .. } => {
854 self.visit(self.ev.tcx.type_of(param.def_id));
857 GenericParamDefKind::Const { has_default, .. } => {
858 self.visit(self.ev.tcx.type_of(param.def_id));
860 self.visit(self.ev.tcx.const_param_default(param.def_id));
868 fn predicates(&mut self) -> &mut Self {
869 self.visit_predicates(self.ev.tcx.predicates_of(self.item_def_id));
873 fn ty(&mut self) -> &mut Self {
874 self.visit(self.ev.tcx.type_of(self.item_def_id));
878 fn trait_ref(&mut self) -> &mut Self {
879 if let Some(trait_ref) = self.ev.tcx.impl_trait_ref(self.item_def_id) {
880 self.visit_trait(trait_ref);
886 impl<'tcx> DefIdVisitor<'tcx> for ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
887 fn tcx(&self) -> TyCtxt<'tcx> {
894 _descr: &dyn fmt::Display,
895 ) -> ControlFlow<Self::BreakTy> {
896 if let Some(def_id) = def_id.as_local() {
897 if let (ty::Visibility::Public, _) | (_, Some(AccessLevel::ReachableFromImplTrait)) =
898 (self.tcx().visibility(def_id.to_def_id()), self.access_level)
900 self.ev.update(def_id, self.access_level);
903 ControlFlow::CONTINUE
907 //////////////////////////////////////////////////////////////////////////////////////
908 /// Name privacy visitor, checks privacy and reports violations.
909 /// Most of name privacy checks are performed during the main resolution phase,
910 /// or later in type checking when field accesses and associated items are resolved.
911 /// This pass performs remaining checks for fields in struct expressions and patterns.
912 //////////////////////////////////////////////////////////////////////////////////////
914 struct NamePrivacyVisitor<'tcx> {
916 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
917 current_item: LocalDefId,
920 impl<'tcx> NamePrivacyVisitor<'tcx> {
921 /// Gets the type-checking results for the current body.
922 /// As this will ICE if called outside bodies, only call when working with
923 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
925 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
926 self.maybe_typeck_results
927 .expect("`NamePrivacyVisitor::typeck_results` called outside of body")
930 // Checks that a field in a struct constructor (expression or pattern) is accessible.
933 use_ctxt: Span, // syntax context of the field name at the use site
934 span: Span, // span of the field pattern, e.g., `x: 0`
935 def: &'tcx ty::AdtDef, // definition of the struct or enum
936 field: &'tcx ty::FieldDef,
937 in_update_syntax: bool,
943 // definition of the field
944 let ident = Ident::new(kw::Empty, use_ctxt);
945 let hir_id = self.tcx.hir().local_def_id_to_hir_id(self.current_item);
946 let def_id = self.tcx.adjust_ident_and_get_scope(ident, def.did, hir_id).1;
947 if !field.vis.is_accessible_from(def_id, self.tcx) {
948 let label = if in_update_syntax {
949 format!("field `{}` is private", field.name)
951 "private field".to_string()
958 "field `{}` of {} `{}` is private",
961 self.tcx.def_path_str(def.did)
963 .span_label(span, label)
969 impl<'tcx> Visitor<'tcx> for NamePrivacyVisitor<'tcx> {
970 type Map = Map<'tcx>;
972 /// We want to visit items in the context of their containing
973 /// module and so forth, so supply a crate for doing a deep walk.
974 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
975 NestedVisitorMap::All(self.tcx.hir())
978 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
979 // Don't visit nested modules, since we run a separate visitor walk
980 // for each module in `privacy_access_levels`
983 fn visit_nested_body(&mut self, body: hir::BodyId) {
984 let old_maybe_typeck_results =
985 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
986 let body = self.tcx.hir().body(body);
987 self.visit_body(body);
988 self.maybe_typeck_results = old_maybe_typeck_results;
991 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
992 let orig_current_item = mem::replace(&mut self.current_item, item.def_id);
993 intravisit::walk_item(self, item);
994 self.current_item = orig_current_item;
997 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
998 if let hir::ExprKind::Struct(qpath, fields, ref base) = expr.kind {
999 let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
1000 let adt = self.typeck_results().expr_ty(expr).ty_adt_def().unwrap();
1001 let variant = adt.variant_of_res(res);
1002 if let Some(base) = *base {
1003 // If the expression uses FRU we need to make sure all the unmentioned fields
1004 // are checked for privacy (RFC 736). Rather than computing the set of
1005 // unmentioned fields, just check them all.
1006 for (vf_index, variant_field) in variant.fields.iter().enumerate() {
1007 let field = fields.iter().find(|f| {
1008 self.tcx.field_index(f.hir_id, self.typeck_results()) == vf_index
1010 let (use_ctxt, span) = match field {
1011 Some(field) => (field.ident.span, field.span),
1012 None => (base.span, base.span),
1014 self.check_field(use_ctxt, span, adt, variant_field, true);
1017 for field in fields {
1018 let use_ctxt = field.ident.span;
1019 let index = self.tcx.field_index(field.hir_id, self.typeck_results());
1020 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1025 intravisit::walk_expr(self, expr);
1028 fn visit_pat(&mut self, pat: &'tcx hir::Pat<'tcx>) {
1029 if let PatKind::Struct(ref qpath, fields, _) = pat.kind {
1030 let res = self.typeck_results().qpath_res(qpath, pat.hir_id);
1031 let adt = self.typeck_results().pat_ty(pat).ty_adt_def().unwrap();
1032 let variant = adt.variant_of_res(res);
1033 for field in fields {
1034 let use_ctxt = field.ident.span;
1035 let index = self.tcx.field_index(field.hir_id, self.typeck_results());
1036 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1040 intravisit::walk_pat(self, pat);
1044 ////////////////////////////////////////////////////////////////////////////////////////////
1045 /// Type privacy visitor, checks types for privacy and reports violations.
1046 /// Both explicitly written types and inferred types of expressions and patterns are checked.
1047 /// Checks are performed on "semantic" types regardless of names and their hygiene.
1048 ////////////////////////////////////////////////////////////////////////////////////////////
1050 struct TypePrivacyVisitor<'tcx> {
1052 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
1053 current_item: LocalDefId,
1057 impl<'tcx> TypePrivacyVisitor<'tcx> {
1058 /// Gets the type-checking results for the current body.
1059 /// As this will ICE if called outside bodies, only call when working with
1060 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
1062 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
1063 self.maybe_typeck_results
1064 .expect("`TypePrivacyVisitor::typeck_results` called outside of body")
1067 fn item_is_accessible(&self, did: DefId) -> bool {
1068 self.tcx.visibility(did).is_accessible_from(self.current_item.to_def_id(), self.tcx)
1071 // Take node-id of an expression or pattern and check its type for privacy.
1072 fn check_expr_pat_type(&mut self, id: hir::HirId, span: Span) -> bool {
1074 let typeck_results = self.typeck_results();
1075 let result: ControlFlow<()> = try {
1076 self.visit(typeck_results.node_type(id))?;
1077 self.visit(typeck_results.node_substs(id))?;
1078 if let Some(adjustments) = typeck_results.adjustments().get(id) {
1079 adjustments.iter().try_for_each(|adjustment| self.visit(adjustment.target))?;
1085 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1086 let is_error = !self.item_is_accessible(def_id);
1090 .struct_span_err(self.span, &format!("{} `{}` is private", kind, descr))
1091 .span_label(self.span, &format!("private {}", kind))
1098 impl<'tcx> Visitor<'tcx> for TypePrivacyVisitor<'tcx> {
1099 type Map = Map<'tcx>;
1101 /// We want to visit items in the context of their containing
1102 /// module and so forth, so supply a crate for doing a deep walk.
1103 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1104 NestedVisitorMap::All(self.tcx.hir())
1107 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
1108 // Don't visit nested modules, since we run a separate visitor walk
1109 // for each module in `privacy_access_levels`
1112 fn visit_nested_body(&mut self, body: hir::BodyId) {
1113 let old_maybe_typeck_results =
1114 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
1115 let body = self.tcx.hir().body(body);
1116 self.visit_body(body);
1117 self.maybe_typeck_results = old_maybe_typeck_results;
1120 fn visit_generic_arg(&mut self, generic_arg: &'tcx hir::GenericArg<'tcx>) {
1122 hir::GenericArg::Type(t) => self.visit_ty(t),
1123 hir::GenericArg::Infer(inf) => self.visit_infer(inf),
1124 hir::GenericArg::Lifetime(_) | hir::GenericArg::Const(_) => {}
1128 fn visit_ty(&mut self, hir_ty: &'tcx hir::Ty<'tcx>) {
1129 self.span = hir_ty.span;
1130 if let Some(typeck_results) = self.maybe_typeck_results {
1132 if self.visit(typeck_results.node_type(hir_ty.hir_id)).is_break() {
1136 // Types in signatures.
1137 // FIXME: This is very ineffective. Ideally each HIR type should be converted
1138 // into a semantic type only once and the result should be cached somehow.
1139 if self.visit(rustc_typeck::hir_ty_to_ty(self.tcx, hir_ty)).is_break() {
1144 intravisit::walk_ty(self, hir_ty);
1147 fn visit_infer(&mut self, inf: &'tcx hir::InferArg) {
1148 self.span = inf.span;
1149 if let Some(typeck_results) = self.maybe_typeck_results {
1150 if let Some(ty) = typeck_results.node_type_opt(inf.hir_id) {
1151 if self.visit(ty).is_break() {
1156 let local_id = self.tcx.hir().local_def_id(inf.hir_id);
1157 if let Some(did) = self.tcx.opt_const_param_of(local_id) {
1158 if self.visit_def_id(did, "inferred", &"").is_break() {
1163 // FIXME see above note for same issue.
1164 if self.visit(rustc_typeck::hir_ty_to_ty(self.tcx, &inf.to_ty())).is_break() {
1168 intravisit::walk_inf(self, inf);
1171 fn visit_trait_ref(&mut self, trait_ref: &'tcx hir::TraitRef<'tcx>) {
1172 self.span = trait_ref.path.span;
1173 if self.maybe_typeck_results.is_none() {
1174 // Avoid calling `hir_trait_to_predicates` in bodies, it will ICE.
1175 // The traits' privacy in bodies is already checked as a part of trait object types.
1176 let bounds = rustc_typeck::hir_trait_to_predicates(
1179 // NOTE: This isn't really right, but the actual type doesn't matter here. It's
1180 // just required by `ty::TraitRef`.
1181 self.tcx.types.never,
1184 for (trait_predicate, _, _) in bounds.trait_bounds {
1185 if self.visit_trait(trait_predicate.skip_binder()).is_break() {
1190 for (poly_predicate, _) in bounds.projection_bounds {
1191 let pred = poly_predicate.skip_binder();
1192 let poly_pred_term = match pred.term {
1193 ty::Term::Ty(ty) => self.visit(ty),
1194 ty::Term::Const(ct) => self.visit(ct),
1196 if poly_pred_term.is_break()
1197 || self.visit_projection_ty(pred.projection_ty).is_break()
1204 intravisit::walk_trait_ref(self, trait_ref);
1207 // Check types of expressions
1208 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
1209 if self.check_expr_pat_type(expr.hir_id, expr.span) {
1210 // Do not check nested expressions if the error already happened.
1214 hir::ExprKind::Assign(_, rhs, _) | hir::ExprKind::Match(rhs, ..) => {
1215 // Do not report duplicate errors for `x = y` and `match x { ... }`.
1216 if self.check_expr_pat_type(rhs.hir_id, rhs.span) {
1220 hir::ExprKind::MethodCall(_, span, _, _) => {
1221 // Method calls have to be checked specially.
1223 if let Some(def_id) = self.typeck_results().type_dependent_def_id(expr.hir_id) {
1224 if self.visit(self.tcx.type_of(def_id)).is_break() {
1230 .delay_span_bug(expr.span, "no type-dependent def for method call");
1236 intravisit::walk_expr(self, expr);
1239 // Prohibit access to associated items with insufficient nominal visibility.
1241 // Additionally, until better reachability analysis for macros 2.0 is available,
1242 // we prohibit access to private statics from other crates, this allows to give
1243 // more code internal visibility at link time. (Access to private functions
1244 // is already prohibited by type privacy for function types.)
1245 fn visit_qpath(&mut self, qpath: &'tcx hir::QPath<'tcx>, id: hir::HirId, span: Span) {
1246 let def = match qpath {
1247 hir::QPath::Resolved(_, path) => match path.res {
1248 Res::Def(kind, def_id) => Some((kind, def_id)),
1251 hir::QPath::TypeRelative(..) | hir::QPath::LangItem(..) => self
1252 .maybe_typeck_results
1253 .and_then(|typeck_results| typeck_results.type_dependent_def(id)),
1255 let def = def.filter(|(kind, _)| {
1258 DefKind::AssocFn | DefKind::AssocConst | DefKind::AssocTy | DefKind::Static
1261 if let Some((kind, def_id)) = def {
1262 let is_local_static =
1263 if let DefKind::Static = kind { def_id.is_local() } else { false };
1264 if !self.item_is_accessible(def_id) && !is_local_static {
1265 let sess = self.tcx.sess;
1266 let sm = sess.source_map();
1267 let name = match qpath {
1268 hir::QPath::Resolved(..) | hir::QPath::LangItem(..) => {
1269 sm.span_to_snippet(qpath.span()).ok()
1271 hir::QPath::TypeRelative(_, segment) => Some(segment.ident.to_string()),
1273 let kind = kind.descr(def_id);
1274 let msg = match name {
1275 Some(name) => format!("{} `{}` is private", kind, name),
1276 None => format!("{} is private", kind),
1278 sess.struct_span_err(span, &msg)
1279 .span_label(span, &format!("private {}", kind))
1285 intravisit::walk_qpath(self, qpath, id, span);
1288 // Check types of patterns.
1289 fn visit_pat(&mut self, pattern: &'tcx hir::Pat<'tcx>) {
1290 if self.check_expr_pat_type(pattern.hir_id, pattern.span) {
1291 // Do not check nested patterns if the error already happened.
1295 intravisit::walk_pat(self, pattern);
1298 fn visit_local(&mut self, local: &'tcx hir::Local<'tcx>) {
1299 if let Some(init) = local.init {
1300 if self.check_expr_pat_type(init.hir_id, init.span) {
1301 // Do not report duplicate errors for `let x = y`.
1306 intravisit::walk_local(self, local);
1309 // Check types in item interfaces.
1310 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1311 let orig_current_item = mem::replace(&mut self.current_item, item.def_id);
1312 let old_maybe_typeck_results = self.maybe_typeck_results.take();
1313 intravisit::walk_item(self, item);
1314 self.maybe_typeck_results = old_maybe_typeck_results;
1315 self.current_item = orig_current_item;
1319 impl<'tcx> DefIdVisitor<'tcx> for TypePrivacyVisitor<'tcx> {
1320 fn tcx(&self) -> TyCtxt<'tcx> {
1327 descr: &dyn fmt::Display,
1328 ) -> ControlFlow<Self::BreakTy> {
1329 if self.check_def_id(def_id, kind, descr) {
1332 ControlFlow::CONTINUE
1337 ///////////////////////////////////////////////////////////////////////////////
1338 /// Obsolete visitors for checking for private items in public interfaces.
1339 /// These visitors are supposed to be kept in frozen state and produce an
1340 /// "old error node set". For backward compatibility the new visitor reports
1341 /// warnings instead of hard errors when the erroneous node is not in this old set.
1342 ///////////////////////////////////////////////////////////////////////////////
1344 struct ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1346 access_levels: &'a AccessLevels,
1348 // Set of errors produced by this obsolete visitor.
1349 old_error_set: HirIdSet,
1352 struct ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1353 inner: &'a ObsoleteVisiblePrivateTypesVisitor<'b, 'tcx>,
1354 /// Whether the type refers to private types.
1355 contains_private: bool,
1356 /// Whether we've recurred at all (i.e., if we're pointing at the
1357 /// first type on which `visit_ty` was called).
1358 at_outer_type: bool,
1359 /// Whether that first type is a public path.
1360 outer_type_is_public_path: bool,
1363 impl<'a, 'tcx> ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1364 fn path_is_private_type(&self, path: &hir::Path<'_>) -> bool {
1365 let did = match path.res {
1366 Res::PrimTy(..) | Res::SelfTy(..) | Res::Err => return false,
1367 res => res.def_id(),
1370 // A path can only be private if:
1371 // it's in this crate...
1372 if let Some(did) = did.as_local() {
1373 // .. and it corresponds to a private type in the AST (this returns
1374 // `None` for type parameters).
1375 match self.tcx.hir().find(self.tcx.hir().local_def_id_to_hir_id(did)) {
1376 Some(Node::Item(item)) => !item.vis.node.is_pub(),
1377 Some(_) | None => false,
1384 fn trait_is_public(&self, trait_id: LocalDefId) -> bool {
1385 // FIXME: this would preferably be using `exported_items`, but all
1386 // traits are exported currently (see `EmbargoVisitor.exported_trait`).
1387 self.access_levels.is_public(trait_id)
1390 fn check_generic_bound(&mut self, bound: &hir::GenericBound<'_>) {
1391 if let hir::GenericBound::Trait(ref trait_ref, _) = *bound {
1392 if self.path_is_private_type(trait_ref.trait_ref.path) {
1393 self.old_error_set.insert(trait_ref.trait_ref.hir_ref_id);
1398 fn item_is_public(&self, def_id: LocalDefId, vis: &hir::Visibility<'_>) -> bool {
1399 self.access_levels.is_reachable(def_id) || vis.node.is_pub()
1403 impl<'a, 'b, 'tcx, 'v> Visitor<'v> for ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1404 type Map = intravisit::ErasedMap<'v>;
1406 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1407 NestedVisitorMap::None
1410 fn visit_generic_arg(&mut self, generic_arg: &'v hir::GenericArg<'v>) {
1412 hir::GenericArg::Type(t) => self.visit_ty(t),
1413 hir::GenericArg::Infer(inf) => self.visit_ty(&inf.to_ty()),
1414 hir::GenericArg::Lifetime(_) | hir::GenericArg::Const(_) => {}
1418 fn visit_ty(&mut self, ty: &hir::Ty<'_>) {
1419 if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = ty.kind {
1420 if self.inner.path_is_private_type(path) {
1421 self.contains_private = true;
1422 // Found what we're looking for, so let's stop working.
1426 if let hir::TyKind::Path(_) = ty.kind {
1427 if self.at_outer_type {
1428 self.outer_type_is_public_path = true;
1431 self.at_outer_type = false;
1432 intravisit::walk_ty(self, ty)
1435 // Don't want to recurse into `[, .. expr]`.
1436 fn visit_expr(&mut self, _: &hir::Expr<'_>) {}
1439 impl<'a, 'tcx> Visitor<'tcx> for ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1440 type Map = Map<'tcx>;
1442 /// We want to visit items in the context of their containing
1443 /// module and so forth, so supply a crate for doing a deep walk.
1444 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1445 NestedVisitorMap::All(self.tcx.hir())
1448 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1450 // Contents of a private mod can be re-exported, so we need
1451 // to check internals.
1452 hir::ItemKind::Mod(_) => {}
1454 // An `extern {}` doesn't introduce a new privacy
1455 // namespace (the contents have their own privacies).
1456 hir::ItemKind::ForeignMod { .. } => {}
1458 hir::ItemKind::Trait(.., bounds, _) => {
1459 if !self.trait_is_public(item.def_id) {
1463 for bound in bounds.iter() {
1464 self.check_generic_bound(bound)
1468 // Impls need some special handling to try to offer useful
1469 // error messages without (too many) false positives
1470 // (i.e., we could just return here to not check them at
1471 // all, or some worse estimation of whether an impl is
1472 // publicly visible).
1473 hir::ItemKind::Impl(ref impl_) => {
1474 // `impl [... for] Private` is never visible.
1475 let self_contains_private;
1476 // `impl [... for] Public<...>`, but not `impl [... for]
1477 // Vec<Public>` or `(Public,)`, etc.
1478 let self_is_public_path;
1480 // Check the properties of the `Self` type:
1482 let mut visitor = ObsoleteCheckTypeForPrivatenessVisitor {
1484 contains_private: false,
1485 at_outer_type: true,
1486 outer_type_is_public_path: false,
1488 visitor.visit_ty(impl_.self_ty);
1489 self_contains_private = visitor.contains_private;
1490 self_is_public_path = visitor.outer_type_is_public_path;
1493 // Miscellaneous info about the impl:
1495 // `true` iff this is `impl Private for ...`.
1496 let not_private_trait = impl_.of_trait.as_ref().map_or(
1497 true, // no trait counts as public trait
1499 if let Some(def_id) = tr.path.res.def_id().as_local() {
1500 self.trait_is_public(def_id)
1502 true // external traits must be public
1507 // `true` iff this is a trait impl or at least one method is public.
1509 // `impl Public { $( fn ...() {} )* }` is not visible.
1511 // This is required over just using the methods' privacy
1512 // directly because we might have `impl<T: Foo<Private>> ...`,
1513 // and we shouldn't warn about the generics if all the methods
1514 // are private (because `T` won't be visible externally).
1515 let trait_or_some_public_method = impl_.of_trait.is_some()
1516 || impl_.items.iter().any(|impl_item_ref| {
1517 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1518 match impl_item.kind {
1519 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..) => {
1520 self.access_levels.is_reachable(impl_item_ref.id.def_id)
1522 hir::ImplItemKind::TyAlias(_) => false,
1526 if !self_contains_private && not_private_trait && trait_or_some_public_method {
1527 intravisit::walk_generics(self, &impl_.generics);
1529 match impl_.of_trait {
1531 for impl_item_ref in impl_.items {
1532 // This is where we choose whether to walk down
1533 // further into the impl to check its items. We
1534 // should only walk into public items so that we
1535 // don't erroneously report errors for private
1536 // types in private items.
1537 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1538 match impl_item.kind {
1539 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..)
1541 .item_is_public(impl_item.def_id, &impl_item.vis) =>
1543 intravisit::walk_impl_item(self, impl_item)
1545 hir::ImplItemKind::TyAlias(..) => {
1546 intravisit::walk_impl_item(self, impl_item)
1553 // Any private types in a trait impl fall into three
1555 // 1. mentioned in the trait definition
1556 // 2. mentioned in the type params/generics
1557 // 3. mentioned in the associated types of the impl
1559 // Those in 1. can only occur if the trait is in
1560 // this crate and will've been warned about on the
1561 // trait definition (there's no need to warn twice
1562 // so we don't check the methods).
1564 // Those in 2. are warned via walk_generics and this
1566 intravisit::walk_path(self, tr.path);
1568 // Those in 3. are warned with this call.
1569 for impl_item_ref in impl_.items {
1570 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1571 if let hir::ImplItemKind::TyAlias(ty) = impl_item.kind {
1577 } else if impl_.of_trait.is_none() && self_is_public_path {
1578 // `impl Public<Private> { ... }`. Any public static
1579 // methods will be visible as `Public::foo`.
1580 let mut found_pub_static = false;
1581 for impl_item_ref in impl_.items {
1582 if self.access_levels.is_reachable(impl_item_ref.id.def_id)
1583 || self.tcx.visibility(impl_item_ref.id.def_id)
1584 == ty::Visibility::Public
1586 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1587 match impl_item_ref.kind {
1588 AssocItemKind::Const => {
1589 found_pub_static = true;
1590 intravisit::walk_impl_item(self, impl_item);
1592 AssocItemKind::Fn { has_self: false } => {
1593 found_pub_static = true;
1594 intravisit::walk_impl_item(self, impl_item);
1600 if found_pub_static {
1601 intravisit::walk_generics(self, &impl_.generics)
1607 // `type ... = ...;` can contain private types, because
1608 // we're introducing a new name.
1609 hir::ItemKind::TyAlias(..) => return,
1611 // Not at all public, so we don't care.
1612 _ if !self.item_is_public(item.def_id, &item.vis) => {
1619 // We've carefully constructed it so that if we're here, then
1620 // any `visit_ty`'s will be called on things that are in
1621 // public signatures, i.e., things that we're interested in for
1623 intravisit::walk_item(self, item);
1626 fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
1627 for param in generics.params {
1628 for bound in param.bounds {
1629 self.check_generic_bound(bound);
1632 for predicate in generics.where_clause.predicates {
1634 hir::WherePredicate::BoundPredicate(bound_pred) => {
1635 for bound in bound_pred.bounds.iter() {
1636 self.check_generic_bound(bound)
1639 hir::WherePredicate::RegionPredicate(_) => {}
1640 hir::WherePredicate::EqPredicate(eq_pred) => {
1641 self.visit_ty(eq_pred.rhs_ty);
1647 fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem<'tcx>) {
1648 if self.access_levels.is_reachable(item.def_id) {
1649 intravisit::walk_foreign_item(self, item)
1653 fn visit_ty(&mut self, t: &'tcx hir::Ty<'tcx>) {
1654 if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = t.kind {
1655 if self.path_is_private_type(path) {
1656 self.old_error_set.insert(t.hir_id);
1659 intravisit::walk_ty(self, t)
1664 v: &'tcx hir::Variant<'tcx>,
1665 g: &'tcx hir::Generics<'tcx>,
1666 item_id: hir::HirId,
1668 if self.access_levels.is_reachable(self.tcx.hir().local_def_id(v.id)) {
1669 self.in_variant = true;
1670 intravisit::walk_variant(self, v, g, item_id);
1671 self.in_variant = false;
1675 fn visit_field_def(&mut self, s: &'tcx hir::FieldDef<'tcx>) {
1676 if s.vis.node.is_pub() || self.in_variant {
1677 intravisit::walk_field_def(self, s);
1681 // We don't need to introspect into these at all: an
1682 // expression/block context can't possibly contain exported things.
1683 // (Making them no-ops stops us from traversing the whole AST without
1684 // having to be super careful about our `walk_...` calls above.)
1685 fn visit_block(&mut self, _: &'tcx hir::Block<'tcx>) {}
1686 fn visit_expr(&mut self, _: &'tcx hir::Expr<'tcx>) {}
1689 ///////////////////////////////////////////////////////////////////////////////
1690 /// SearchInterfaceForPrivateItemsVisitor traverses an item's interface and
1691 /// finds any private components in it.
1692 /// PrivateItemsInPublicInterfacesVisitor ensures there are no private types
1693 /// and traits in public interfaces.
1694 ///////////////////////////////////////////////////////////////////////////////
1696 struct SearchInterfaceForPrivateItemsVisitor<'tcx> {
1698 item_def_id: LocalDefId,
1699 /// The visitor checks that each component type is at least this visible.
1700 required_visibility: ty::Visibility,
1701 has_pub_restricted: bool,
1702 has_old_errors: bool,
1706 impl SearchInterfaceForPrivateItemsVisitor<'_> {
1707 fn generics(&mut self) -> &mut Self {
1708 for param in &self.tcx.generics_of(self.item_def_id).params {
1710 GenericParamDefKind::Lifetime => {}
1711 GenericParamDefKind::Type { has_default, .. } => {
1713 self.visit(self.tcx.type_of(param.def_id));
1716 // FIXME(generic_const_exprs): May want to look inside const here
1717 GenericParamDefKind::Const { .. } => {
1718 self.visit(self.tcx.type_of(param.def_id));
1725 fn predicates(&mut self) -> &mut Self {
1726 // N.B., we use `explicit_predicates_of` and not `predicates_of`
1727 // because we don't want to report privacy errors due to where
1728 // clauses that the compiler inferred. We only want to
1729 // consider the ones that the user wrote. This is important
1730 // for the inferred outlives rules; see
1731 // `src/test/ui/rfc-2093-infer-outlives/privacy.rs`.
1732 self.visit_predicates(self.tcx.explicit_predicates_of(self.item_def_id));
1736 fn bounds(&mut self) -> &mut Self {
1737 self.visit_predicates(ty::GenericPredicates {
1739 predicates: self.tcx.explicit_item_bounds(self.item_def_id),
1744 fn ty(&mut self) -> &mut Self {
1745 self.visit(self.tcx.type_of(self.item_def_id));
1749 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1750 if self.leaks_private_dep(def_id) {
1751 self.tcx.struct_span_lint_hir(
1752 lint::builtin::EXPORTED_PRIVATE_DEPENDENCIES,
1753 self.tcx.hir().local_def_id_to_hir_id(self.item_def_id),
1754 self.tcx.def_span(self.item_def_id.to_def_id()),
1756 lint.build(&format!(
1757 "{} `{}` from private dependency '{}' in public \
1761 self.tcx.crate_name(def_id.krate)
1768 let hir_id = match def_id.as_local() {
1769 Some(def_id) => self.tcx.hir().local_def_id_to_hir_id(def_id),
1770 None => return false,
1773 let vis = self.tcx.visibility(def_id);
1774 if !vis.is_at_least(self.required_visibility, self.tcx) {
1775 let vis_descr = match vis {
1776 ty::Visibility::Public => "public",
1777 ty::Visibility::Invisible => "private",
1778 ty::Visibility::Restricted(vis_def_id) => {
1779 if vis_def_id == self.tcx.parent_module(hir_id).to_def_id() {
1781 } else if vis_def_id.is_top_level_module() {
1788 let make_msg = || format!("{} {} `{}` in public interface", vis_descr, kind, descr);
1789 let span = self.tcx.def_span(self.item_def_id.to_def_id());
1790 if self.has_pub_restricted || self.has_old_errors || self.in_assoc_ty {
1791 let mut err = if kind == "trait" {
1792 struct_span_err!(self.tcx.sess, span, E0445, "{}", make_msg())
1794 struct_span_err!(self.tcx.sess, span, E0446, "{}", make_msg())
1797 self.tcx.sess.source_map().guess_head_span(self.tcx.def_span(def_id));
1798 err.span_label(span, format!("can't leak {} {}", vis_descr, kind));
1799 err.span_label(vis_span, format!("`{}` declared as {}", descr, vis_descr));
1802 let err_code = if kind == "trait" { "E0445" } else { "E0446" };
1803 self.tcx.struct_span_lint_hir(
1804 lint::builtin::PRIVATE_IN_PUBLIC,
1807 |lint| lint.build(&format!("{} (error {})", make_msg(), err_code)).emit(),
1815 /// An item is 'leaked' from a private dependency if all
1816 /// of the following are true:
1817 /// 1. It's contained within a public type
1818 /// 2. It comes from a private crate
1819 fn leaks_private_dep(&self, item_id: DefId) -> bool {
1820 let ret = self.required_visibility.is_public() && self.tcx.is_private_dep(item_id.krate);
1822 tracing::debug!("leaks_private_dep(item_id={:?})={}", item_id, ret);
1827 impl<'tcx> DefIdVisitor<'tcx> for SearchInterfaceForPrivateItemsVisitor<'tcx> {
1828 fn tcx(&self) -> TyCtxt<'tcx> {
1835 descr: &dyn fmt::Display,
1836 ) -> ControlFlow<Self::BreakTy> {
1837 if self.check_def_id(def_id, kind, descr) {
1840 ControlFlow::CONTINUE
1845 struct PrivateItemsInPublicInterfacesVisitor<'tcx> {
1847 has_pub_restricted: bool,
1848 old_error_set_ancestry: LocalDefIdSet,
1851 impl<'tcx> PrivateItemsInPublicInterfacesVisitor<'tcx> {
1855 required_visibility: ty::Visibility,
1856 ) -> SearchInterfaceForPrivateItemsVisitor<'tcx> {
1857 SearchInterfaceForPrivateItemsVisitor {
1859 item_def_id: def_id,
1860 required_visibility,
1861 has_pub_restricted: self.has_pub_restricted,
1862 has_old_errors: self.old_error_set_ancestry.contains(&def_id),
1867 fn check_assoc_item(
1870 assoc_item_kind: AssocItemKind,
1871 defaultness: hir::Defaultness,
1872 vis: ty::Visibility,
1874 let mut check = self.check(def_id, vis);
1876 let (check_ty, is_assoc_ty) = match assoc_item_kind {
1877 AssocItemKind::Const | AssocItemKind::Fn { .. } => (true, false),
1878 AssocItemKind::Type => (defaultness.has_value(), true),
1880 check.in_assoc_ty = is_assoc_ty;
1881 check.generics().predicates();
1888 impl<'tcx> Visitor<'tcx> for PrivateItemsInPublicInterfacesVisitor<'tcx> {
1889 type Map = Map<'tcx>;
1891 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1892 NestedVisitorMap::OnlyBodies(self.tcx.hir())
1895 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1897 let item_visibility = tcx.visibility(item.def_id);
1900 // Crates are always public.
1901 hir::ItemKind::ExternCrate(..) => {}
1902 // All nested items are checked by `visit_item`.
1903 hir::ItemKind::Mod(..) => {}
1904 // Checked in resolve.
1905 hir::ItemKind::Use(..) => {}
1907 hir::ItemKind::Macro(..) | hir::ItemKind::GlobalAsm(..) => {}
1908 // Subitems of these items have inherited publicity.
1909 hir::ItemKind::Const(..)
1910 | hir::ItemKind::Static(..)
1911 | hir::ItemKind::Fn(..)
1912 | hir::ItemKind::TyAlias(..) => {
1913 self.check(item.def_id, item_visibility).generics().predicates().ty();
1915 hir::ItemKind::OpaqueTy(..) => {
1916 // `ty()` for opaque types is the underlying type,
1917 // it's not a part of interface, so we skip it.
1918 self.check(item.def_id, item_visibility).generics().bounds();
1920 hir::ItemKind::Trait(.., trait_item_refs) => {
1921 self.check(item.def_id, item_visibility).generics().predicates();
1923 for trait_item_ref in trait_item_refs {
1924 self.check_assoc_item(
1925 trait_item_ref.id.def_id,
1926 trait_item_ref.kind,
1927 trait_item_ref.defaultness,
1931 if let AssocItemKind::Type = trait_item_ref.kind {
1932 self.check(trait_item_ref.id.def_id, item_visibility).bounds();
1936 hir::ItemKind::TraitAlias(..) => {
1937 self.check(item.def_id, item_visibility).generics().predicates();
1939 hir::ItemKind::Enum(ref def, _) => {
1940 self.check(item.def_id, item_visibility).generics().predicates();
1942 for variant in def.variants {
1943 for field in variant.data.fields() {
1944 self.check(self.tcx.hir().local_def_id(field.hir_id), item_visibility).ty();
1948 // Subitems of foreign modules have their own publicity.
1949 hir::ItemKind::ForeignMod { items, .. } => {
1950 for foreign_item in items {
1951 let vis = tcx.visibility(foreign_item.id.def_id);
1952 self.check(foreign_item.id.def_id, vis).generics().predicates().ty();
1955 // Subitems of structs and unions have their own publicity.
1956 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
1957 self.check(item.def_id, item_visibility).generics().predicates();
1959 for field in struct_def.fields() {
1960 let def_id = tcx.hir().local_def_id(field.hir_id);
1961 let field_visibility = tcx.visibility(def_id);
1962 self.check(def_id, min(item_visibility, field_visibility, tcx)).ty();
1965 // An inherent impl is public when its type is public
1966 // Subitems of inherent impls have their own publicity.
1967 // A trait impl is public when both its type and its trait are public
1968 // Subitems of trait impls have inherited publicity.
1969 hir::ItemKind::Impl(ref impl_) => {
1970 let impl_vis = ty::Visibility::of_impl(item.def_id, tcx, &Default::default());
1971 // check that private components do not appear in the generics or predicates of inherent impls
1972 // this check is intentionally NOT performed for impls of traits, per #90586
1973 if impl_.of_trait.is_none() {
1974 self.check(item.def_id, impl_vis).generics().predicates();
1976 for impl_item_ref in impl_.items {
1977 let impl_item_vis = if impl_.of_trait.is_none() {
1978 min(tcx.visibility(impl_item_ref.id.def_id), impl_vis, tcx)
1982 self.check_assoc_item(
1983 impl_item_ref.id.def_id,
1985 impl_item_ref.defaultness,
1994 pub fn provide(providers: &mut Providers) {
1995 *providers = Providers {
1997 privacy_access_levels,
1998 check_private_in_public,
2004 fn visibility(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Visibility {
2005 let def_id = def_id.expect_local();
2006 match tcx.resolutions(()).visibilities.get(&def_id) {
2009 let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
2010 match tcx.hir().get(hir_id) {
2011 // Unique types created for closures participate in type privacy checking.
2012 // They have visibilities inherited from the module they are defined in.
2013 Node::Expr(hir::Expr { kind: hir::ExprKind::Closure(..), .. }) => {
2014 ty::Visibility::Restricted(tcx.parent_module(hir_id).to_def_id())
2016 // - AST lowering may clone `use` items and the clones don't
2017 // get their entries in the resolver's visibility table.
2018 // - AST lowering also creates opaque type items with inherited visibilies.
2019 // Visibility on them should have no effect, but to avoid the visibility
2020 // query failing on some items, we provide it for opaque types as well.
2021 Node::Item(hir::Item {
2023 kind: hir::ItemKind::Use(..) | hir::ItemKind::OpaqueTy(..),
2025 }) => ty::Visibility::from_hir(vis, hir_id, tcx),
2026 // Visibilities of trait impl items are inherited from their traits
2027 // and are not filled in resolve.
2028 Node::ImplItem(impl_item) => {
2029 match tcx.hir().get_by_def_id(tcx.hir().get_parent_item(hir_id)) {
2030 Node::Item(hir::Item {
2031 kind: hir::ItemKind::Impl(hir::Impl { of_trait: Some(tr), .. }),
2033 }) => tr.path.res.opt_def_id().map_or_else(
2035 tcx.sess.delay_span_bug(tr.path.span, "trait without a def-id");
2036 ty::Visibility::Public
2038 |def_id| tcx.visibility(def_id),
2040 _ => span_bug!(impl_item.span, "the parent is not a trait impl"),
2044 tcx.def_span(def_id),
2045 "visibility table unexpectedly missing a def-id: {:?}",
2053 fn check_mod_privacy(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
2054 // Check privacy of names not checked in previous compilation stages.
2056 NamePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id };
2057 let (module, span, hir_id) = tcx.hir().get_module(module_def_id);
2059 intravisit::walk_mod(&mut visitor, module, hir_id);
2061 // Check privacy of explicitly written types and traits as well as
2062 // inferred types of expressions and patterns.
2064 TypePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id, span };
2065 intravisit::walk_mod(&mut visitor, module, hir_id);
2068 fn privacy_access_levels(tcx: TyCtxt<'_>, (): ()) -> &AccessLevels {
2069 // Build up a set of all exported items in the AST. This is a set of all
2070 // items which are reachable from external crates based on visibility.
2071 let mut visitor = EmbargoVisitor {
2073 access_levels: tcx.resolutions(()).access_levels.clone(),
2074 macro_reachable: Default::default(),
2075 prev_level: Some(AccessLevel::Public),
2080 tcx.hir().walk_toplevel_module(&mut visitor);
2081 if visitor.changed {
2082 visitor.changed = false;
2088 tcx.arena.alloc(visitor.access_levels)
2091 fn check_private_in_public(tcx: TyCtxt<'_>, (): ()) {
2092 let access_levels = tcx.privacy_access_levels(());
2094 let mut visitor = ObsoleteVisiblePrivateTypesVisitor {
2098 old_error_set: Default::default(),
2100 tcx.hir().walk_toplevel_module(&mut visitor);
2102 let has_pub_restricted = {
2103 let mut pub_restricted_visitor = PubRestrictedVisitor { tcx, has_pub_restricted: false };
2104 tcx.hir().walk_toplevel_module(&mut pub_restricted_visitor);
2105 pub_restricted_visitor.has_pub_restricted
2108 let mut old_error_set_ancestry = HirIdSet::default();
2109 for mut id in visitor.old_error_set.iter().copied() {
2111 if !old_error_set_ancestry.insert(id) {
2114 let parent = tcx.hir().get_parent_node(id);
2122 // Check for private types and traits in public interfaces.
2123 let mut visitor = PrivateItemsInPublicInterfacesVisitor {
2126 // Only definition IDs are ever searched in `old_error_set_ancestry`,
2127 // so we can filter away all non-definition IDs at this point.
2128 old_error_set_ancestry: old_error_set_ancestry
2130 .filter_map(|hir_id| tcx.hir().opt_local_def_id(hir_id))
2133 tcx.hir().visit_all_item_likes(&mut DeepVisitor::new(&mut visitor));