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_data_structures::intern::Interned;
13 use rustc_errors::struct_span_err;
15 use rustc_hir::def::{DefKind, Res};
16 use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdSet, CRATE_DEF_ID};
17 use rustc_hir::intravisit::{self, DeepVisitor, Visitor};
18 use rustc_hir::{AssocItemKind, HirIdSet, Node, PatKind};
19 use rustc_middle::bug;
20 use rustc_middle::hir::nested_filter;
21 use rustc_middle::middle::privacy::{AccessLevel, AccessLevels};
22 use rustc_middle::span_bug;
23 use rustc_middle::thir::abstract_const::Node as ACNode;
24 use rustc_middle::ty::fold::TypeVisitor;
25 use rustc_middle::ty::query::Providers;
26 use rustc_middle::ty::subst::InternalSubsts;
27 use rustc_middle::ty::{self, Const, GenericParamDefKind, TraitRef, Ty, TyCtxt, TypeFoldable};
28 use rustc_session::lint;
29 use rustc_span::hygiene::Transparency;
30 use rustc_span::symbol::{kw, Ident};
32 use rustc_trait_selection::traits::const_evaluatable::{self, AbstractConst};
34 use std::marker::PhantomData;
35 use std::ops::ControlFlow;
36 use std::{cmp, fmt, mem};
38 ////////////////////////////////////////////////////////////////////////////////
39 /// Generic infrastructure used to implement specific visitors below.
40 ////////////////////////////////////////////////////////////////////////////////
42 /// Implemented to visit all `DefId`s in a type.
43 /// Visiting `DefId`s is useful because visibilities and reachabilities are attached to them.
44 /// The idea is to visit "all components of a type", as documented in
45 /// <https://github.com/rust-lang/rfcs/blob/master/text/2145-type-privacy.md#how-to-determine-visibility-of-a-type>.
46 /// The default type visitor (`TypeVisitor`) does most of the job, but it has some shortcomings.
47 /// First, it doesn't have overridable `fn visit_trait_ref`, so we have to catch trait `DefId`s
48 /// manually. Second, it doesn't visit some type components like signatures of fn types, or traits
49 /// in `impl Trait`, see individual comments in `DefIdVisitorSkeleton::visit_ty`.
50 trait DefIdVisitor<'tcx> {
53 fn tcx(&self) -> TyCtxt<'tcx>;
54 fn shallow(&self) -> bool {
57 fn skip_assoc_tys(&self) -> bool {
64 descr: &dyn fmt::Display,
65 ) -> ControlFlow<Self::BreakTy>;
67 /// Not overridden, but used to actually visit types and traits.
68 fn skeleton(&mut self) -> DefIdVisitorSkeleton<'_, 'tcx, Self> {
69 DefIdVisitorSkeleton {
71 visited_opaque_tys: Default::default(),
72 dummy: Default::default(),
75 fn visit(&mut self, ty_fragment: impl TypeFoldable<'tcx>) -> ControlFlow<Self::BreakTy> {
76 ty_fragment.visit_with(&mut self.skeleton())
78 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> ControlFlow<Self::BreakTy> {
79 self.skeleton().visit_trait(trait_ref)
81 fn visit_projection_ty(
83 projection: ty::ProjectionTy<'tcx>,
84 ) -> ControlFlow<Self::BreakTy> {
85 self.skeleton().visit_projection_ty(projection)
89 predicates: ty::GenericPredicates<'tcx>,
90 ) -> ControlFlow<Self::BreakTy> {
91 self.skeleton().visit_predicates(predicates)
95 struct DefIdVisitorSkeleton<'v, 'tcx, V: ?Sized> {
96 def_id_visitor: &'v mut V,
97 visited_opaque_tys: FxHashSet<DefId>,
98 dummy: PhantomData<TyCtxt<'tcx>>,
101 impl<'tcx, V> DefIdVisitorSkeleton<'_, 'tcx, V>
103 V: DefIdVisitor<'tcx> + ?Sized,
105 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> ControlFlow<V::BreakTy> {
106 let TraitRef { def_id, substs } = trait_ref;
107 self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref.print_only_trait_path())?;
108 if self.def_id_visitor.shallow() { ControlFlow::CONTINUE } else { substs.visit_with(self) }
111 fn visit_projection_ty(
113 projection: ty::ProjectionTy<'tcx>,
114 ) -> ControlFlow<V::BreakTy> {
115 let (trait_ref, assoc_substs) =
116 projection.trait_ref_and_own_substs(self.def_id_visitor.tcx());
117 self.visit_trait(trait_ref)?;
118 if self.def_id_visitor.shallow() {
119 ControlFlow::CONTINUE
121 assoc_substs.iter().try_for_each(|subst| subst.visit_with(self))
125 fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> ControlFlow<V::BreakTy> {
126 match predicate.kind().skip_binder() {
127 ty::PredicateKind::Trait(ty::TraitPredicate {
131 }) => self.visit_trait(trait_ref),
132 ty::PredicateKind::Projection(ty::ProjectionPredicate { projection_ty, term }) => {
133 term.visit_with(self)?;
134 self.visit_projection_ty(projection_ty)
136 ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(ty, _region)) => {
139 ty::PredicateKind::RegionOutlives(..) => ControlFlow::CONTINUE,
140 ty::PredicateKind::ConstEvaluatable(uv)
141 if self.def_id_visitor.tcx().features().generic_const_exprs =>
143 let tcx = self.def_id_visitor.tcx();
144 if let Ok(Some(ct)) = AbstractConst::new(tcx, uv) {
145 self.visit_abstract_const_expr(tcx, ct)?;
147 ControlFlow::CONTINUE
149 _ => bug!("unexpected predicate: {:?}", predicate),
153 fn visit_abstract_const_expr(
156 ct: AbstractConst<'tcx>,
157 ) -> ControlFlow<V::BreakTy> {
158 const_evaluatable::walk_abstract_const(tcx, ct, |node| match node.root(tcx) {
159 ACNode::Leaf(leaf) => self.visit_const(leaf),
160 ACNode::Cast(_, _, ty) => self.visit_ty(ty),
161 ACNode::Binop(..) | ACNode::UnaryOp(..) | ACNode::FunctionCall(_, _) => {
162 ControlFlow::CONTINUE
169 predicates: ty::GenericPredicates<'tcx>,
170 ) -> ControlFlow<V::BreakTy> {
171 let ty::GenericPredicates { parent: _, predicates } = predicates;
172 predicates.iter().try_for_each(|&(predicate, _span)| self.visit_predicate(predicate))
176 impl<'tcx, V> TypeVisitor<'tcx> for DefIdVisitorSkeleton<'_, 'tcx, V>
178 V: DefIdVisitor<'tcx> + ?Sized,
180 type BreakTy = V::BreakTy;
182 fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<V::BreakTy> {
183 let tcx = self.def_id_visitor.tcx();
184 // InternalSubsts are not visited here because they are visited below in `super_visit_with`.
186 ty::Adt(ty::AdtDef(Interned(&ty::AdtDefData { did: def_id, .. }, _)), ..)
187 | ty::Foreign(def_id)
188 | ty::FnDef(def_id, ..)
189 | ty::Closure(def_id, ..)
190 | ty::Generator(def_id, ..) => {
191 self.def_id_visitor.visit_def_id(def_id, "type", &ty)?;
192 if self.def_id_visitor.shallow() {
193 return ControlFlow::CONTINUE;
195 // Default type visitor doesn't visit signatures of fn types.
196 // Something like `fn() -> Priv {my_func}` is considered a private type even if
197 // `my_func` is public, so we need to visit signatures.
198 if let ty::FnDef(..) = ty.kind() {
199 tcx.fn_sig(def_id).visit_with(self)?;
201 // Inherent static methods don't have self type in substs.
202 // Something like `fn() {my_method}` type of the method
203 // `impl Pub<Priv> { pub fn my_method() {} }` is considered a private type,
204 // so we need to visit the self type additionally.
205 if let Some(assoc_item) = tcx.opt_associated_item(def_id) {
206 if let ty::ImplContainer(impl_def_id) = assoc_item.container {
207 tcx.type_of(impl_def_id).visit_with(self)?;
211 ty::Projection(proj) => {
212 if self.def_id_visitor.skip_assoc_tys() {
213 // Visitors searching for minimal visibility/reachability want to
214 // conservatively approximate associated types like `<Type as Trait>::Alias`
215 // as visible/reachable even if both `Type` and `Trait` are private.
216 // Ideally, associated types should be substituted in the same way as
217 // free type aliases, but this isn't done yet.
218 return ControlFlow::CONTINUE;
220 // This will also visit substs if necessary, so we don't need to recurse.
221 return self.visit_projection_ty(proj);
223 ty::Dynamic(predicates, ..) => {
224 // All traits in the list are considered the "primary" part of the type
225 // and are visited by shallow visitors.
226 for predicate in predicates {
227 let trait_ref = match predicate.skip_binder() {
228 ty::ExistentialPredicate::Trait(trait_ref) => trait_ref,
229 ty::ExistentialPredicate::Projection(proj) => proj.trait_ref(tcx),
230 ty::ExistentialPredicate::AutoTrait(def_id) => {
231 ty::ExistentialTraitRef { def_id, substs: InternalSubsts::empty() }
234 let ty::ExistentialTraitRef { def_id, substs: _ } = trait_ref;
235 self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref)?;
238 ty::Opaque(def_id, ..) => {
239 // Skip repeated `Opaque`s to avoid infinite recursion.
240 if self.visited_opaque_tys.insert(def_id) {
241 // The intent is to treat `impl Trait1 + Trait2` identically to
242 // `dyn Trait1 + Trait2`. Therefore we ignore def-id of the opaque type itself
243 // (it either has no visibility, or its visibility is insignificant, like
244 // visibilities of type aliases) and recurse into bounds instead to go
245 // through the trait list (default type visitor doesn't visit those traits).
246 // All traits in the list are considered the "primary" part of the type
247 // and are visited by shallow visitors.
248 self.visit_predicates(ty::GenericPredicates {
250 predicates: tcx.explicit_item_bounds(def_id),
254 // These types don't have their own def-ids (but may have subcomponents
255 // with def-ids that should be visited recursively).
271 | ty::GeneratorWitness(..) => {}
272 ty::Bound(..) | ty::Placeholder(..) | ty::Infer(..) => {
273 bug!("unexpected type: {:?}", ty)
277 if self.def_id_visitor.shallow() {
278 ControlFlow::CONTINUE
280 ty.super_visit_with(self)
284 fn visit_const(&mut self, c: Const<'tcx>) -> ControlFlow<Self::BreakTy> {
285 self.visit_ty(c.ty())?;
286 let tcx = self.def_id_visitor.tcx();
287 if let Ok(Some(ct)) = AbstractConst::from_const(tcx, c) {
288 self.visit_abstract_const_expr(tcx, ct)?;
290 ControlFlow::CONTINUE
294 fn min(vis1: ty::Visibility, vis2: ty::Visibility, tcx: TyCtxt<'_>) -> ty::Visibility {
295 if vis1.is_at_least(vis2, tcx) { vis2 } else { vis1 }
298 ////////////////////////////////////////////////////////////////////////////////
299 /// Visitor used to determine impl visibility and reachability.
300 ////////////////////////////////////////////////////////////////////////////////
302 struct FindMin<'a, 'tcx, VL: VisibilityLike> {
304 access_levels: &'a AccessLevels,
308 impl<'a, 'tcx, VL: VisibilityLike> DefIdVisitor<'tcx> for FindMin<'a, 'tcx, VL> {
309 fn tcx(&self) -> TyCtxt<'tcx> {
312 fn shallow(&self) -> bool {
315 fn skip_assoc_tys(&self) -> bool {
322 _descr: &dyn fmt::Display,
323 ) -> ControlFlow<Self::BreakTy> {
324 self.min = VL::new_min(self, def_id);
325 ControlFlow::CONTINUE
329 trait VisibilityLike: Sized {
331 const SHALLOW: bool = false;
332 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self;
334 // Returns an over-approximation (`skip_assoc_tys` = true) of visibility due to
335 // associated types for which we can't determine visibility precisely.
336 fn of_impl(def_id: LocalDefId, tcx: TyCtxt<'_>, access_levels: &AccessLevels) -> Self {
337 let mut find = FindMin { tcx, access_levels, min: Self::MAX };
338 find.visit(tcx.type_of(def_id));
339 if let Some(trait_ref) = tcx.impl_trait_ref(def_id) {
340 find.visit_trait(trait_ref);
345 impl VisibilityLike for ty::Visibility {
346 const MAX: Self = ty::Visibility::Public;
347 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
348 min(find.tcx.visibility(def_id), find.min, find.tcx)
351 impl VisibilityLike for Option<AccessLevel> {
352 const MAX: Self = Some(AccessLevel::Public);
353 // Type inference is very smart sometimes.
354 // It can make an impl reachable even some components of its type or trait are unreachable.
355 // E.g. methods of `impl ReachableTrait<UnreachableTy> for ReachableTy<UnreachableTy> { ... }`
356 // can be usable from other crates (#57264). So we skip substs when calculating reachability
357 // and consider an impl reachable if its "shallow" type and trait are reachable.
359 // The assumption we make here is that type-inference won't let you use an impl without knowing
360 // both "shallow" version of its self type and "shallow" version of its trait if it exists
361 // (which require reaching the `DefId`s in them).
362 const SHALLOW: bool = true;
363 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
365 if let Some(def_id) = def_id.as_local() {
366 find.access_levels.map.get(&def_id).copied()
375 ////////////////////////////////////////////////////////////////////////////////
376 /// The embargo visitor, used to determine the exports of the AST.
377 ////////////////////////////////////////////////////////////////////////////////
379 struct EmbargoVisitor<'tcx> {
382 /// Accessibility levels for reachable nodes.
383 access_levels: AccessLevels,
384 /// A set of pairs corresponding to modules, where the first module is
385 /// reachable via a macro that's defined in the second module. This cannot
386 /// be represented as reachable because it can't handle the following case:
388 /// pub mod n { // Should be `Public`
389 /// pub(crate) mod p { // Should *not* be accessible
390 /// pub fn f() -> i32 { 12 } // Must be `Reachable`
396 macro_reachable: FxHashSet<(LocalDefId, LocalDefId)>,
397 /// Previous accessibility level; `None` means unreachable.
398 prev_level: Option<AccessLevel>,
399 /// Has something changed in the level map?
403 struct ReachEverythingInTheInterfaceVisitor<'a, 'tcx> {
404 access_level: Option<AccessLevel>,
405 item_def_id: LocalDefId,
406 ev: &'a mut EmbargoVisitor<'tcx>,
409 impl<'tcx> EmbargoVisitor<'tcx> {
410 fn get(&self, def_id: LocalDefId) -> Option<AccessLevel> {
411 self.access_levels.map.get(&def_id).copied()
414 fn update_with_hir_id(
417 level: Option<AccessLevel>,
418 ) -> Option<AccessLevel> {
419 let def_id = self.tcx.hir().local_def_id(hir_id);
420 self.update(def_id, level)
423 /// Updates node level and returns the updated level.
424 fn update(&mut self, def_id: LocalDefId, level: Option<AccessLevel>) -> Option<AccessLevel> {
425 let old_level = self.get(def_id);
426 // Accessibility levels can only grow.
427 if level > old_level {
428 self.access_levels.map.insert(def_id, level.unwrap());
439 access_level: Option<AccessLevel>,
440 ) -> ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
441 ReachEverythingInTheInterfaceVisitor {
442 access_level: cmp::min(access_level, Some(AccessLevel::Reachable)),
448 // We have to make sure that the items that macros might reference
449 // are reachable, since they might be exported transitively.
450 fn update_reachability_from_macro(&mut self, local_def_id: LocalDefId, md: &MacroDef) {
451 // Non-opaque macros cannot make other items more accessible than they already are.
453 let hir_id = self.tcx.hir().local_def_id_to_hir_id(local_def_id);
454 let attrs = self.tcx.hir().attrs(hir_id);
455 if attr::find_transparency(attrs, md.macro_rules).0 != Transparency::Opaque {
459 let item_def_id = local_def_id.to_def_id();
460 let macro_module_def_id =
461 ty::DefIdTree::parent(self.tcx, item_def_id).unwrap().expect_local();
462 if self.tcx.hir().opt_def_kind(macro_module_def_id) != Some(DefKind::Mod) {
463 // The macro's parent doesn't correspond to a `mod`, return early (#63164, #65252).
467 if self.get(local_def_id).is_none() {
471 // Since we are starting from an externally visible module,
472 // all the parents in the loop below are also guaranteed to be modules.
473 let mut module_def_id = macro_module_def_id;
475 let changed_reachability =
476 self.update_macro_reachable(module_def_id, macro_module_def_id);
477 if changed_reachability || module_def_id == CRATE_DEF_ID {
481 ty::DefIdTree::parent(self.tcx, module_def_id.to_def_id()).unwrap().expect_local();
485 /// Updates the item as being reachable through a macro defined in the given
486 /// module. Returns `true` if the level has changed.
487 fn update_macro_reachable(
489 module_def_id: LocalDefId,
490 defining_mod: LocalDefId,
492 if self.macro_reachable.insert((module_def_id, defining_mod)) {
493 self.update_macro_reachable_mod(module_def_id, defining_mod);
500 fn update_macro_reachable_mod(&mut self, module_def_id: LocalDefId, defining_mod: LocalDefId) {
501 let module = self.tcx.hir().get_module(module_def_id).0;
502 for item_id in module.item_ids {
503 let def_kind = self.tcx.def_kind(item_id.def_id);
504 let vis = self.tcx.visibility(item_id.def_id);
505 self.update_macro_reachable_def(item_id.def_id, def_kind, vis, defining_mod);
507 if let Some(exports) = self.tcx.module_reexports(module_def_id) {
508 for export in exports {
509 if export.vis.is_accessible_from(defining_mod.to_def_id(), self.tcx) {
510 if let Res::Def(def_kind, def_id) = export.res {
511 if let Some(def_id) = def_id.as_local() {
512 let vis = self.tcx.visibility(def_id.to_def_id());
513 self.update_macro_reachable_def(def_id, def_kind, vis, defining_mod);
521 fn update_macro_reachable_def(
528 let level = Some(AccessLevel::Reachable);
530 self.update(def_id, level);
533 // No type privacy, so can be directly marked as reachable.
534 DefKind::Const | DefKind::Static(_) | DefKind::TraitAlias | DefKind::TyAlias => {
535 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
536 self.update(def_id, level);
540 // Hygiene isn't really implemented for `macro_rules!` macros at the
541 // moment. Accordingly, marking them as reachable is unwise. `macro` macros
542 // have normal hygiene, so we can treat them like other items without type
543 // privacy and mark them reachable.
544 DefKind::Macro(_) => {
545 let item = self.tcx.hir().expect_item(def_id);
546 if let hir::ItemKind::Macro(MacroDef { macro_rules: false, .. }, _) = item.kind {
547 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
548 self.update(def_id, level);
553 // We can't use a module name as the final segment of a path, except
554 // in use statements. Since re-export checking doesn't consider
555 // hygiene these don't need to be marked reachable. The contents of
556 // the module, however may be reachable.
558 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
559 self.update_macro_reachable(def_id, module);
563 DefKind::Struct | DefKind::Union => {
564 // While structs and unions have type privacy, their fields do not.
566 let item = self.tcx.hir().expect_item(def_id);
567 if let hir::ItemKind::Struct(ref struct_def, _)
568 | hir::ItemKind::Union(ref struct_def, _) = item.kind
570 for field in struct_def.fields() {
571 let def_id = self.tcx.hir().local_def_id(field.hir_id);
572 let field_vis = self.tcx.visibility(def_id);
573 if field_vis.is_accessible_from(module.to_def_id(), self.tcx) {
574 self.reach(def_id, level).ty();
578 bug!("item {:?} with DefKind {:?}", item, def_kind);
583 // These have type privacy, so are not reachable unless they're
584 // public, or are not namespaced at all.
587 | DefKind::ConstParam
588 | DefKind::Ctor(_, _)
597 | DefKind::LifetimeParam
598 | DefKind::ExternCrate
600 | DefKind::ForeignMod
602 | DefKind::InlineConst
607 | DefKind::Generator => (),
612 impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
613 type NestedFilter = nested_filter::All;
615 /// We want to visit items in the context of their containing
616 /// module and so forth, so supply a crate for doing a deep walk.
617 fn nested_visit_map(&mut self) -> Self::Map {
621 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
622 let item_level = match item.kind {
623 hir::ItemKind::Impl { .. } => {
625 Option::<AccessLevel>::of_impl(item.def_id, self.tcx, &self.access_levels);
626 self.update(item.def_id, impl_level)
628 _ => self.get(item.def_id),
631 // Update levels of nested things.
633 hir::ItemKind::Enum(ref def, _) => {
634 for variant in def.variants {
635 let variant_level = self.update_with_hir_id(variant.id, item_level);
636 if let Some(ctor_hir_id) = variant.data.ctor_hir_id() {
637 self.update_with_hir_id(ctor_hir_id, item_level);
639 for field in variant.data.fields() {
640 self.update_with_hir_id(field.hir_id, variant_level);
644 hir::ItemKind::Impl(ref impl_) => {
645 for impl_item_ref in impl_.items {
646 if impl_.of_trait.is_some()
647 || self.tcx.visibility(impl_item_ref.id.def_id) == ty::Visibility::Public
649 self.update(impl_item_ref.id.def_id, item_level);
653 hir::ItemKind::Trait(.., trait_item_refs) => {
654 for trait_item_ref in trait_item_refs {
655 self.update(trait_item_ref.id.def_id, item_level);
658 hir::ItemKind::Struct(ref def, _) | hir::ItemKind::Union(ref def, _) => {
659 if let Some(ctor_hir_id) = def.ctor_hir_id() {
660 self.update_with_hir_id(ctor_hir_id, item_level);
662 for field in def.fields() {
663 let def_id = self.tcx.hir().local_def_id(field.hir_id);
664 let vis = self.tcx.visibility(def_id);
666 self.update_with_hir_id(field.hir_id, item_level);
670 hir::ItemKind::Macro(ref macro_def, _) => {
671 self.update_reachability_from_macro(item.def_id, macro_def);
673 hir::ItemKind::ForeignMod { items, .. } => {
674 for foreign_item in items {
675 if self.tcx.visibility(foreign_item.id.def_id) == ty::Visibility::Public {
676 self.update(foreign_item.id.def_id, item_level);
681 hir::ItemKind::OpaqueTy(..)
682 | hir::ItemKind::Use(..)
683 | hir::ItemKind::Static(..)
684 | hir::ItemKind::Const(..)
685 | hir::ItemKind::GlobalAsm(..)
686 | hir::ItemKind::TyAlias(..)
687 | hir::ItemKind::Mod(..)
688 | hir::ItemKind::TraitAlias(..)
689 | hir::ItemKind::Fn(..)
690 | hir::ItemKind::ExternCrate(..) => {}
693 // Mark all items in interfaces of reachable items as reachable.
695 // The interface is empty.
696 hir::ItemKind::Macro(..) | hir::ItemKind::ExternCrate(..) => {}
697 // All nested items are checked by `visit_item`.
698 hir::ItemKind::Mod(..) => {}
699 // Handled in the access level of in rustc_resolve
700 hir::ItemKind::Use(..) => {}
701 // The interface is empty.
702 hir::ItemKind::GlobalAsm(..) => {}
703 hir::ItemKind::OpaqueTy(..) => {
704 // HACK(jynelson): trying to infer the type of `impl trait` breaks `async-std` (and `pub async fn` in general)
705 // Since rustdoc never needs to do codegen and doesn't care about link-time reachability,
706 // mark this as unreachable.
707 // See https://github.com/rust-lang/rust/issues/75100
708 if !self.tcx.sess.opts.actually_rustdoc {
709 // FIXME: This is some serious pessimization intended to workaround deficiencies
710 // in the reachability pass (`middle/reachable.rs`). Types are marked as link-time
711 // reachable if they are returned via `impl Trait`, even from private functions.
713 cmp::max(item_level, Some(AccessLevel::ReachableFromImplTrait));
714 self.reach(item.def_id, exist_level).generics().predicates().ty();
718 hir::ItemKind::Const(..)
719 | hir::ItemKind::Static(..)
720 | hir::ItemKind::Fn(..)
721 | hir::ItemKind::TyAlias(..) => {
722 if item_level.is_some() {
723 self.reach(item.def_id, item_level).generics().predicates().ty();
726 hir::ItemKind::Trait(.., trait_item_refs) => {
727 if item_level.is_some() {
728 self.reach(item.def_id, item_level).generics().predicates();
730 for trait_item_ref in trait_item_refs {
731 let mut reach = self.reach(trait_item_ref.id.def_id, item_level);
732 reach.generics().predicates();
734 if trait_item_ref.kind == AssocItemKind::Type
735 && !trait_item_ref.defaultness.has_value()
744 hir::ItemKind::TraitAlias(..) => {
745 if item_level.is_some() {
746 self.reach(item.def_id, item_level).generics().predicates();
749 // Visit everything except for private impl items.
750 hir::ItemKind::Impl(ref impl_) => {
751 if item_level.is_some() {
752 self.reach(item.def_id, item_level).generics().predicates().ty().trait_ref();
754 for impl_item_ref in impl_.items {
755 let impl_item_level = self.get(impl_item_ref.id.def_id);
756 if impl_item_level.is_some() {
757 self.reach(impl_item_ref.id.def_id, impl_item_level)
766 // Visit everything, but enum variants have their own levels.
767 hir::ItemKind::Enum(ref def, _) => {
768 if item_level.is_some() {
769 self.reach(item.def_id, item_level).generics().predicates();
771 for variant in def.variants {
772 let variant_level = self.get(self.tcx.hir().local_def_id(variant.id));
773 if variant_level.is_some() {
774 for field in variant.data.fields() {
775 self.reach(self.tcx.hir().local_def_id(field.hir_id), variant_level)
778 // Corner case: if the variant is reachable, but its
779 // enum is not, make the enum reachable as well.
780 self.update(item.def_id, variant_level);
784 // Visit everything, but foreign items have their own levels.
785 hir::ItemKind::ForeignMod { items, .. } => {
786 for foreign_item in items {
787 let foreign_item_level = self.get(foreign_item.id.def_id);
788 if foreign_item_level.is_some() {
789 self.reach(foreign_item.id.def_id, foreign_item_level)
796 // Visit everything except for private fields.
797 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
798 if item_level.is_some() {
799 self.reach(item.def_id, item_level).generics().predicates();
800 for field in struct_def.fields() {
801 let def_id = self.tcx.hir().local_def_id(field.hir_id);
802 let field_level = self.get(def_id);
803 if field_level.is_some() {
804 self.reach(def_id, field_level).ty();
811 let orig_level = mem::replace(&mut self.prev_level, item_level);
812 intravisit::walk_item(self, item);
813 self.prev_level = orig_level;
816 fn visit_block(&mut self, b: &'tcx hir::Block<'tcx>) {
817 // Blocks can have public items, for example impls, but they always
818 // start as completely private regardless of publicity of a function,
819 // constant, type, field, etc., in which this block resides.
820 let orig_level = mem::replace(&mut self.prev_level, None);
821 intravisit::walk_block(self, b);
822 self.prev_level = orig_level;
826 impl ReachEverythingInTheInterfaceVisitor<'_, '_> {
827 fn generics(&mut self) -> &mut Self {
828 for param in &self.ev.tcx.generics_of(self.item_def_id).params {
830 GenericParamDefKind::Lifetime => {}
831 GenericParamDefKind::Type { has_default, .. } => {
833 self.visit(self.ev.tcx.type_of(param.def_id));
836 GenericParamDefKind::Const { has_default } => {
837 self.visit(self.ev.tcx.type_of(param.def_id));
839 self.visit(self.ev.tcx.const_param_default(param.def_id));
847 fn predicates(&mut self) -> &mut Self {
848 self.visit_predicates(self.ev.tcx.predicates_of(self.item_def_id));
852 fn ty(&mut self) -> &mut Self {
853 self.visit(self.ev.tcx.type_of(self.item_def_id));
857 fn trait_ref(&mut self) -> &mut Self {
858 if let Some(trait_ref) = self.ev.tcx.impl_trait_ref(self.item_def_id) {
859 self.visit_trait(trait_ref);
865 impl<'tcx> DefIdVisitor<'tcx> for ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
866 fn tcx(&self) -> TyCtxt<'tcx> {
873 _descr: &dyn fmt::Display,
874 ) -> ControlFlow<Self::BreakTy> {
875 if let Some(def_id) = def_id.as_local() {
876 if let (ty::Visibility::Public, _) | (_, Some(AccessLevel::ReachableFromImplTrait)) =
877 (self.tcx().visibility(def_id.to_def_id()), self.access_level)
879 self.ev.update(def_id, self.access_level);
882 ControlFlow::CONTINUE
886 //////////////////////////////////////////////////////////////////////////////////////
887 /// Name privacy visitor, checks privacy and reports violations.
888 /// Most of name privacy checks are performed during the main resolution phase,
889 /// or later in type checking when field accesses and associated items are resolved.
890 /// This pass performs remaining checks for fields in struct expressions and patterns.
891 //////////////////////////////////////////////////////////////////////////////////////
893 struct NamePrivacyVisitor<'tcx> {
895 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
896 current_item: LocalDefId,
899 impl<'tcx> NamePrivacyVisitor<'tcx> {
900 /// Gets the type-checking results for the current body.
901 /// As this will ICE if called outside bodies, only call when working with
902 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
904 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
905 self.maybe_typeck_results
906 .expect("`NamePrivacyVisitor::typeck_results` called outside of body")
909 // Checks that a field in a struct constructor (expression or pattern) is accessible.
912 use_ctxt: Span, // syntax context of the field name at the use site
913 span: Span, // span of the field pattern, e.g., `x: 0`
914 def: ty::AdtDef<'tcx>, // definition of the struct or enum
915 field: &'tcx ty::FieldDef,
916 in_update_syntax: bool,
922 // definition of the field
923 let ident = Ident::new(kw::Empty, use_ctxt);
924 let hir_id = self.tcx.hir().local_def_id_to_hir_id(self.current_item);
925 let def_id = self.tcx.adjust_ident_and_get_scope(ident, def.did(), hir_id).1;
926 if !field.vis.is_accessible_from(def_id, self.tcx) {
927 let label = if in_update_syntax {
928 format!("field `{}` is private", field.name)
930 "private field".to_string()
937 "field `{}` of {} `{}` is private",
940 self.tcx.def_path_str(def.did())
942 .span_label(span, label)
948 impl<'tcx> Visitor<'tcx> for NamePrivacyVisitor<'tcx> {
949 type NestedFilter = nested_filter::All;
951 /// We want to visit items in the context of their containing
952 /// module and so forth, so supply a crate for doing a deep walk.
953 fn nested_visit_map(&mut self) -> Self::Map {
957 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
958 // Don't visit nested modules, since we run a separate visitor walk
959 // for each module in `privacy_access_levels`
962 fn visit_nested_body(&mut self, body: hir::BodyId) {
963 let old_maybe_typeck_results =
964 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
965 let body = self.tcx.hir().body(body);
966 self.visit_body(body);
967 self.maybe_typeck_results = old_maybe_typeck_results;
970 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
971 let orig_current_item = mem::replace(&mut self.current_item, item.def_id);
972 intravisit::walk_item(self, item);
973 self.current_item = orig_current_item;
976 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
977 if let hir::ExprKind::Struct(qpath, fields, ref base) = expr.kind {
978 let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
979 let adt = self.typeck_results().expr_ty(expr).ty_adt_def().unwrap();
980 let variant = adt.variant_of_res(res);
981 if let Some(base) = *base {
982 // If the expression uses FRU we need to make sure all the unmentioned fields
983 // are checked for privacy (RFC 736). Rather than computing the set of
984 // unmentioned fields, just check them all.
985 for (vf_index, variant_field) in variant.fields.iter().enumerate() {
986 let field = fields.iter().find(|f| {
987 self.tcx.field_index(f.hir_id, self.typeck_results()) == vf_index
989 let (use_ctxt, span) = match field {
990 Some(field) => (field.ident.span, field.span),
991 None => (base.span, base.span),
993 self.check_field(use_ctxt, span, adt, variant_field, true);
996 for field in fields {
997 let use_ctxt = field.ident.span;
998 let index = self.tcx.field_index(field.hir_id, self.typeck_results());
999 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1004 intravisit::walk_expr(self, expr);
1007 fn visit_pat(&mut self, pat: &'tcx hir::Pat<'tcx>) {
1008 if let PatKind::Struct(ref qpath, fields, _) = pat.kind {
1009 let res = self.typeck_results().qpath_res(qpath, pat.hir_id);
1010 let adt = self.typeck_results().pat_ty(pat).ty_adt_def().unwrap();
1011 let variant = adt.variant_of_res(res);
1012 for field in fields {
1013 let use_ctxt = field.ident.span;
1014 let index = self.tcx.field_index(field.hir_id, self.typeck_results());
1015 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1019 intravisit::walk_pat(self, pat);
1023 ////////////////////////////////////////////////////////////////////////////////////////////
1024 /// Type privacy visitor, checks types for privacy and reports violations.
1025 /// Both explicitly written types and inferred types of expressions and patterns are checked.
1026 /// Checks are performed on "semantic" types regardless of names and their hygiene.
1027 ////////////////////////////////////////////////////////////////////////////////////////////
1029 struct TypePrivacyVisitor<'tcx> {
1031 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
1032 current_item: LocalDefId,
1036 impl<'tcx> TypePrivacyVisitor<'tcx> {
1037 /// Gets the type-checking results for the current body.
1038 /// As this will ICE if called outside bodies, only call when working with
1039 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
1041 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
1042 self.maybe_typeck_results
1043 .expect("`TypePrivacyVisitor::typeck_results` called outside of body")
1046 fn item_is_accessible(&self, did: DefId) -> bool {
1047 self.tcx.visibility(did).is_accessible_from(self.current_item.to_def_id(), self.tcx)
1050 // Take node-id of an expression or pattern and check its type for privacy.
1051 fn check_expr_pat_type(&mut self, id: hir::HirId, span: Span) -> bool {
1053 let typeck_results = self.typeck_results();
1054 let result: ControlFlow<()> = try {
1055 self.visit(typeck_results.node_type(id))?;
1056 self.visit(typeck_results.node_substs(id))?;
1057 if let Some(adjustments) = typeck_results.adjustments().get(id) {
1058 adjustments.iter().try_for_each(|adjustment| self.visit(adjustment.target))?;
1064 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1065 let is_error = !self.item_is_accessible(def_id);
1069 .struct_span_err(self.span, &format!("{} `{}` is private", kind, descr))
1070 .span_label(self.span, &format!("private {}", kind))
1077 impl<'tcx> Visitor<'tcx> for TypePrivacyVisitor<'tcx> {
1078 type NestedFilter = nested_filter::All;
1080 /// We want to visit items in the context of their containing
1081 /// module and so forth, so supply a crate for doing a deep walk.
1082 fn nested_visit_map(&mut self) -> Self::Map {
1086 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
1087 // Don't visit nested modules, since we run a separate visitor walk
1088 // for each module in `privacy_access_levels`
1091 fn visit_nested_body(&mut self, body: hir::BodyId) {
1092 let old_maybe_typeck_results =
1093 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
1094 let body = self.tcx.hir().body(body);
1095 self.visit_body(body);
1096 self.maybe_typeck_results = old_maybe_typeck_results;
1099 fn visit_generic_arg(&mut self, generic_arg: &'tcx hir::GenericArg<'tcx>) {
1101 hir::GenericArg::Type(t) => self.visit_ty(t),
1102 hir::GenericArg::Infer(inf) => self.visit_infer(inf),
1103 hir::GenericArg::Lifetime(_) | hir::GenericArg::Const(_) => {}
1107 fn visit_ty(&mut self, hir_ty: &'tcx hir::Ty<'tcx>) {
1108 self.span = hir_ty.span;
1109 if let Some(typeck_results) = self.maybe_typeck_results {
1111 if self.visit(typeck_results.node_type(hir_ty.hir_id)).is_break() {
1115 // Types in signatures.
1116 // FIXME: This is very ineffective. Ideally each HIR type should be converted
1117 // into a semantic type only once and the result should be cached somehow.
1118 if self.visit(rustc_typeck::hir_ty_to_ty(self.tcx, hir_ty)).is_break() {
1123 intravisit::walk_ty(self, hir_ty);
1126 fn visit_infer(&mut self, inf: &'tcx hir::InferArg) {
1127 self.span = inf.span;
1128 if let Some(typeck_results) = self.maybe_typeck_results {
1129 if let Some(ty) = typeck_results.node_type_opt(inf.hir_id) {
1130 if self.visit(ty).is_break() {
1134 // We don't do anything for const infers here.
1137 bug!("visit_infer without typeck_results");
1139 intravisit::walk_inf(self, inf);
1142 fn visit_trait_ref(&mut self, trait_ref: &'tcx hir::TraitRef<'tcx>) {
1143 self.span = trait_ref.path.span;
1144 if self.maybe_typeck_results.is_none() {
1145 // Avoid calling `hir_trait_to_predicates` in bodies, it will ICE.
1146 // The traits' privacy in bodies is already checked as a part of trait object types.
1147 let bounds = rustc_typeck::hir_trait_to_predicates(
1150 // NOTE: This isn't really right, but the actual type doesn't matter here. It's
1151 // just required by `ty::TraitRef`.
1152 self.tcx.types.never,
1155 for (trait_predicate, _, _) in bounds.trait_bounds {
1156 if self.visit_trait(trait_predicate.skip_binder()).is_break() {
1161 for (poly_predicate, _) in bounds.projection_bounds {
1162 let pred = poly_predicate.skip_binder();
1163 let poly_pred_term = self.visit(pred.term);
1164 if poly_pred_term.is_break()
1165 || self.visit_projection_ty(pred.projection_ty).is_break()
1172 intravisit::walk_trait_ref(self, trait_ref);
1175 // Check types of expressions
1176 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
1177 if self.check_expr_pat_type(expr.hir_id, expr.span) {
1178 // Do not check nested expressions if the error already happened.
1182 hir::ExprKind::Assign(_, rhs, _) | hir::ExprKind::Match(rhs, ..) => {
1183 // Do not report duplicate errors for `x = y` and `match x { ... }`.
1184 if self.check_expr_pat_type(rhs.hir_id, rhs.span) {
1188 hir::ExprKind::MethodCall(segment, ..) => {
1189 // Method calls have to be checked specially.
1190 self.span = segment.ident.span;
1191 if let Some(def_id) = self.typeck_results().type_dependent_def_id(expr.hir_id) {
1192 if self.visit(self.tcx.type_of(def_id)).is_break() {
1198 .delay_span_bug(expr.span, "no type-dependent def for method call");
1204 intravisit::walk_expr(self, expr);
1207 // Prohibit access to associated items with insufficient nominal visibility.
1209 // Additionally, until better reachability analysis for macros 2.0 is available,
1210 // we prohibit access to private statics from other crates, this allows to give
1211 // more code internal visibility at link time. (Access to private functions
1212 // is already prohibited by type privacy for function types.)
1213 fn visit_qpath(&mut self, qpath: &'tcx hir::QPath<'tcx>, id: hir::HirId, span: Span) {
1214 let def = match qpath {
1215 hir::QPath::Resolved(_, path) => match path.res {
1216 Res::Def(kind, def_id) => Some((kind, def_id)),
1219 hir::QPath::TypeRelative(..) | hir::QPath::LangItem(..) => self
1220 .maybe_typeck_results
1221 .and_then(|typeck_results| typeck_results.type_dependent_def(id)),
1223 let def = def.filter(|(kind, _)| {
1226 DefKind::AssocFn | DefKind::AssocConst | DefKind::AssocTy | DefKind::Static(_)
1229 if let Some((kind, def_id)) = def {
1230 let is_local_static =
1231 if let DefKind::Static(_) = kind { def_id.is_local() } else { false };
1232 if !self.item_is_accessible(def_id) && !is_local_static {
1233 let sess = self.tcx.sess;
1234 let sm = sess.source_map();
1235 let name = match qpath {
1236 hir::QPath::Resolved(..) | hir::QPath::LangItem(..) => {
1237 sm.span_to_snippet(qpath.span()).ok()
1239 hir::QPath::TypeRelative(_, segment) => Some(segment.ident.to_string()),
1241 let kind = kind.descr(def_id);
1242 let msg = match name {
1243 Some(name) => format!("{} `{}` is private", kind, name),
1244 None => format!("{} is private", kind),
1246 sess.struct_span_err(span, &msg)
1247 .span_label(span, &format!("private {}", kind))
1253 intravisit::walk_qpath(self, qpath, id, span);
1256 // Check types of patterns.
1257 fn visit_pat(&mut self, pattern: &'tcx hir::Pat<'tcx>) {
1258 if self.check_expr_pat_type(pattern.hir_id, pattern.span) {
1259 // Do not check nested patterns if the error already happened.
1263 intravisit::walk_pat(self, pattern);
1266 fn visit_local(&mut self, local: &'tcx hir::Local<'tcx>) {
1267 if let Some(init) = local.init {
1268 if self.check_expr_pat_type(init.hir_id, init.span) {
1269 // Do not report duplicate errors for `let x = y`.
1274 intravisit::walk_local(self, local);
1277 // Check types in item interfaces.
1278 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1279 let orig_current_item = mem::replace(&mut self.current_item, item.def_id);
1280 let old_maybe_typeck_results = self.maybe_typeck_results.take();
1281 intravisit::walk_item(self, item);
1282 self.maybe_typeck_results = old_maybe_typeck_results;
1283 self.current_item = orig_current_item;
1287 impl<'tcx> DefIdVisitor<'tcx> for TypePrivacyVisitor<'tcx> {
1288 fn tcx(&self) -> TyCtxt<'tcx> {
1295 descr: &dyn fmt::Display,
1296 ) -> ControlFlow<Self::BreakTy> {
1297 if self.check_def_id(def_id, kind, descr) {
1300 ControlFlow::CONTINUE
1305 ///////////////////////////////////////////////////////////////////////////////
1306 /// Obsolete visitors for checking for private items in public interfaces.
1307 /// These visitors are supposed to be kept in frozen state and produce an
1308 /// "old error node set". For backward compatibility the new visitor reports
1309 /// warnings instead of hard errors when the erroneous node is not in this old set.
1310 ///////////////////////////////////////////////////////////////////////////////
1312 struct ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1314 access_levels: &'a AccessLevels,
1316 // Set of errors produced by this obsolete visitor.
1317 old_error_set: HirIdSet,
1320 struct ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1321 inner: &'a ObsoleteVisiblePrivateTypesVisitor<'b, 'tcx>,
1322 /// Whether the type refers to private types.
1323 contains_private: bool,
1324 /// Whether we've recurred at all (i.e., if we're pointing at the
1325 /// first type on which `visit_ty` was called).
1326 at_outer_type: bool,
1327 /// Whether that first type is a public path.
1328 outer_type_is_public_path: bool,
1331 impl<'a, 'tcx> ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1332 fn path_is_private_type(&self, path: &hir::Path<'_>) -> bool {
1333 let did = match path.res {
1334 Res::PrimTy(..) | Res::SelfTy { .. } | Res::Err => return false,
1335 res => res.def_id(),
1338 // A path can only be private if:
1339 // it's in this crate...
1340 if let Some(did) = did.as_local() {
1341 // .. and it corresponds to a private type in the AST (this returns
1342 // `None` for type parameters).
1343 match self.tcx.hir().find(self.tcx.hir().local_def_id_to_hir_id(did)) {
1344 Some(Node::Item(_)) => !self.tcx.visibility(did).is_public(),
1345 Some(_) | None => false,
1352 fn trait_is_public(&self, trait_id: LocalDefId) -> bool {
1353 // FIXME: this would preferably be using `exported_items`, but all
1354 // traits are exported currently (see `EmbargoVisitor.exported_trait`).
1355 self.access_levels.is_public(trait_id)
1358 fn check_generic_bound(&mut self, bound: &hir::GenericBound<'_>) {
1359 if let hir::GenericBound::Trait(ref trait_ref, _) = *bound {
1360 if self.path_is_private_type(trait_ref.trait_ref.path) {
1361 self.old_error_set.insert(trait_ref.trait_ref.hir_ref_id);
1366 fn item_is_public(&self, def_id: LocalDefId) -> bool {
1367 self.access_levels.is_reachable(def_id) || self.tcx.visibility(def_id).is_public()
1371 impl<'a, 'b, 'tcx, 'v> Visitor<'v> for ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1372 fn visit_generic_arg(&mut self, generic_arg: &'v hir::GenericArg<'v>) {
1374 hir::GenericArg::Type(t) => self.visit_ty(t),
1375 hir::GenericArg::Infer(inf) => self.visit_ty(&inf.to_ty()),
1376 hir::GenericArg::Lifetime(_) | hir::GenericArg::Const(_) => {}
1380 fn visit_ty(&mut self, ty: &hir::Ty<'_>) {
1381 if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = ty.kind {
1382 if self.inner.path_is_private_type(path) {
1383 self.contains_private = true;
1384 // Found what we're looking for, so let's stop working.
1388 if let hir::TyKind::Path(_) = ty.kind {
1389 if self.at_outer_type {
1390 self.outer_type_is_public_path = true;
1393 self.at_outer_type = false;
1394 intravisit::walk_ty(self, ty)
1397 // Don't want to recurse into `[, .. expr]`.
1398 fn visit_expr(&mut self, _: &hir::Expr<'_>) {}
1401 impl<'a, 'tcx> Visitor<'tcx> for ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1402 type NestedFilter = nested_filter::All;
1404 /// We want to visit items in the context of their containing
1405 /// module and so forth, so supply a crate for doing a deep walk.
1406 fn nested_visit_map(&mut self) -> Self::Map {
1410 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1412 // Contents of a private mod can be re-exported, so we need
1413 // to check internals.
1414 hir::ItemKind::Mod(_) => {}
1416 // An `extern {}` doesn't introduce a new privacy
1417 // namespace (the contents have their own privacies).
1418 hir::ItemKind::ForeignMod { .. } => {}
1420 hir::ItemKind::Trait(.., bounds, _) => {
1421 if !self.trait_is_public(item.def_id) {
1425 for bound in bounds.iter() {
1426 self.check_generic_bound(bound)
1430 // Impls need some special handling to try to offer useful
1431 // error messages without (too many) false positives
1432 // (i.e., we could just return here to not check them at
1433 // all, or some worse estimation of whether an impl is
1434 // publicly visible).
1435 hir::ItemKind::Impl(ref impl_) => {
1436 // `impl [... for] Private` is never visible.
1437 let self_contains_private;
1438 // `impl [... for] Public<...>`, but not `impl [... for]
1439 // Vec<Public>` or `(Public,)`, etc.
1440 let self_is_public_path;
1442 // Check the properties of the `Self` type:
1444 let mut visitor = ObsoleteCheckTypeForPrivatenessVisitor {
1446 contains_private: false,
1447 at_outer_type: true,
1448 outer_type_is_public_path: false,
1450 visitor.visit_ty(impl_.self_ty);
1451 self_contains_private = visitor.contains_private;
1452 self_is_public_path = visitor.outer_type_is_public_path;
1455 // Miscellaneous info about the impl:
1457 // `true` iff this is `impl Private for ...`.
1458 let not_private_trait = impl_.of_trait.as_ref().map_or(
1459 true, // no trait counts as public trait
1461 if let Some(def_id) = tr.path.res.def_id().as_local() {
1462 self.trait_is_public(def_id)
1464 true // external traits must be public
1469 // `true` iff this is a trait impl or at least one method is public.
1471 // `impl Public { $( fn ...() {} )* }` is not visible.
1473 // This is required over just using the methods' privacy
1474 // directly because we might have `impl<T: Foo<Private>> ...`,
1475 // and we shouldn't warn about the generics if all the methods
1476 // are private (because `T` won't be visible externally).
1477 let trait_or_some_public_method = impl_.of_trait.is_some()
1478 || impl_.items.iter().any(|impl_item_ref| {
1479 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1480 match impl_item.kind {
1481 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..) => {
1482 self.access_levels.is_reachable(impl_item_ref.id.def_id)
1484 hir::ImplItemKind::TyAlias(_) => false,
1488 if !self_contains_private && not_private_trait && trait_or_some_public_method {
1489 intravisit::walk_generics(self, &impl_.generics);
1491 match impl_.of_trait {
1493 for impl_item_ref in impl_.items {
1494 // This is where we choose whether to walk down
1495 // further into the impl to check its items. We
1496 // should only walk into public items so that we
1497 // don't erroneously report errors for private
1498 // types in private items.
1499 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1500 match impl_item.kind {
1501 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..)
1502 if self.item_is_public(impl_item.def_id) =>
1504 intravisit::walk_impl_item(self, impl_item)
1506 hir::ImplItemKind::TyAlias(..) => {
1507 intravisit::walk_impl_item(self, impl_item)
1514 // Any private types in a trait impl fall into three
1516 // 1. mentioned in the trait definition
1517 // 2. mentioned in the type params/generics
1518 // 3. mentioned in the associated types of the impl
1520 // Those in 1. can only occur if the trait is in
1521 // this crate and will have been warned about on the
1522 // trait definition (there's no need to warn twice
1523 // so we don't check the methods).
1525 // Those in 2. are warned via walk_generics and this
1527 intravisit::walk_path(self, tr.path);
1529 // Those in 3. are warned with this call.
1530 for impl_item_ref in impl_.items {
1531 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1532 if let hir::ImplItemKind::TyAlias(ty) = impl_item.kind {
1538 } else if impl_.of_trait.is_none() && self_is_public_path {
1539 // `impl Public<Private> { ... }`. Any public static
1540 // methods will be visible as `Public::foo`.
1541 let mut found_pub_static = false;
1542 for impl_item_ref in impl_.items {
1543 if self.access_levels.is_reachable(impl_item_ref.id.def_id)
1544 || self.tcx.visibility(impl_item_ref.id.def_id)
1545 == ty::Visibility::Public
1547 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1548 match impl_item_ref.kind {
1549 AssocItemKind::Const => {
1550 found_pub_static = true;
1551 intravisit::walk_impl_item(self, impl_item);
1553 AssocItemKind::Fn { has_self: false } => {
1554 found_pub_static = true;
1555 intravisit::walk_impl_item(self, impl_item);
1561 if found_pub_static {
1562 intravisit::walk_generics(self, &impl_.generics)
1568 // `type ... = ...;` can contain private types, because
1569 // we're introducing a new name.
1570 hir::ItemKind::TyAlias(..) => return,
1572 // Not at all public, so we don't care.
1573 _ if !self.item_is_public(item.def_id) => {
1580 // We've carefully constructed it so that if we're here, then
1581 // any `visit_ty`'s will be called on things that are in
1582 // public signatures, i.e., things that we're interested in for
1584 intravisit::walk_item(self, item);
1587 fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
1588 for predicate in generics.predicates {
1590 hir::WherePredicate::BoundPredicate(bound_pred) => {
1591 for bound in bound_pred.bounds.iter() {
1592 self.check_generic_bound(bound)
1595 hir::WherePredicate::RegionPredicate(_) => {}
1596 hir::WherePredicate::EqPredicate(eq_pred) => {
1597 self.visit_ty(eq_pred.rhs_ty);
1603 fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem<'tcx>) {
1604 if self.access_levels.is_reachable(item.def_id) {
1605 intravisit::walk_foreign_item(self, item)
1609 fn visit_ty(&mut self, t: &'tcx hir::Ty<'tcx>) {
1610 if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = t.kind {
1611 if self.path_is_private_type(path) {
1612 self.old_error_set.insert(t.hir_id);
1615 intravisit::walk_ty(self, t)
1620 v: &'tcx hir::Variant<'tcx>,
1621 g: &'tcx hir::Generics<'tcx>,
1622 item_id: hir::HirId,
1624 if self.access_levels.is_reachable(self.tcx.hir().local_def_id(v.id)) {
1625 self.in_variant = true;
1626 intravisit::walk_variant(self, v, g, item_id);
1627 self.in_variant = false;
1631 fn visit_field_def(&mut self, s: &'tcx hir::FieldDef<'tcx>) {
1632 let def_id = self.tcx.hir().local_def_id(s.hir_id);
1633 let vis = self.tcx.visibility(def_id);
1634 if vis.is_public() || self.in_variant {
1635 intravisit::walk_field_def(self, s);
1639 // We don't need to introspect into these at all: an
1640 // expression/block context can't possibly contain exported things.
1641 // (Making them no-ops stops us from traversing the whole AST without
1642 // having to be super careful about our `walk_...` calls above.)
1643 fn visit_block(&mut self, _: &'tcx hir::Block<'tcx>) {}
1644 fn visit_expr(&mut self, _: &'tcx hir::Expr<'tcx>) {}
1647 ///////////////////////////////////////////////////////////////////////////////
1648 /// SearchInterfaceForPrivateItemsVisitor traverses an item's interface and
1649 /// finds any private components in it.
1650 /// PrivateItemsInPublicInterfacesVisitor ensures there are no private types
1651 /// and traits in public interfaces.
1652 ///////////////////////////////////////////////////////////////////////////////
1654 struct SearchInterfaceForPrivateItemsVisitor<'tcx> {
1656 item_def_id: LocalDefId,
1657 /// The visitor checks that each component type is at least this visible.
1658 required_visibility: ty::Visibility,
1659 has_old_errors: bool,
1663 impl SearchInterfaceForPrivateItemsVisitor<'_> {
1664 fn generics(&mut self) -> &mut Self {
1665 for param in &self.tcx.generics_of(self.item_def_id).params {
1667 GenericParamDefKind::Lifetime => {}
1668 GenericParamDefKind::Type { has_default, .. } => {
1670 self.visit(self.tcx.type_of(param.def_id));
1673 // FIXME(generic_const_exprs): May want to look inside const here
1674 GenericParamDefKind::Const { .. } => {
1675 self.visit(self.tcx.type_of(param.def_id));
1682 fn predicates(&mut self) -> &mut Self {
1683 // N.B., we use `explicit_predicates_of` and not `predicates_of`
1684 // because we don't want to report privacy errors due to where
1685 // clauses that the compiler inferred. We only want to
1686 // consider the ones that the user wrote. This is important
1687 // for the inferred outlives rules; see
1688 // `src/test/ui/rfc-2093-infer-outlives/privacy.rs`.
1689 self.visit_predicates(self.tcx.explicit_predicates_of(self.item_def_id));
1693 fn bounds(&mut self) -> &mut Self {
1694 self.visit_predicates(ty::GenericPredicates {
1696 predicates: self.tcx.explicit_item_bounds(self.item_def_id),
1701 fn ty(&mut self) -> &mut Self {
1702 self.visit(self.tcx.type_of(self.item_def_id));
1706 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1707 if self.leaks_private_dep(def_id) {
1708 self.tcx.struct_span_lint_hir(
1709 lint::builtin::EXPORTED_PRIVATE_DEPENDENCIES,
1710 self.tcx.hir().local_def_id_to_hir_id(self.item_def_id),
1711 self.tcx.def_span(self.item_def_id.to_def_id()),
1713 lint.build(&format!(
1714 "{} `{}` from private dependency '{}' in public \
1718 self.tcx.crate_name(def_id.krate)
1725 let hir_id = match def_id.as_local() {
1726 Some(def_id) => self.tcx.hir().local_def_id_to_hir_id(def_id),
1727 None => return false,
1730 let vis = self.tcx.visibility(def_id);
1731 if !vis.is_at_least(self.required_visibility, self.tcx) {
1732 let vis_descr = match vis {
1733 ty::Visibility::Public => "public",
1734 ty::Visibility::Invisible => "private",
1735 ty::Visibility::Restricted(vis_def_id) => {
1736 if vis_def_id == self.tcx.parent_module(hir_id).to_def_id() {
1738 } else if vis_def_id.is_top_level_module() {
1745 let make_msg = || format!("{} {} `{}` in public interface", vis_descr, kind, descr);
1746 let span = self.tcx.def_span(self.item_def_id.to_def_id());
1747 if self.has_old_errors
1749 || self.tcx.resolutions(()).has_pub_restricted
1751 let mut err = if kind == "trait" {
1752 struct_span_err!(self.tcx.sess, span, E0445, "{}", make_msg())
1754 struct_span_err!(self.tcx.sess, span, E0446, "{}", make_msg())
1757 self.tcx.sess.source_map().guess_head_span(self.tcx.def_span(def_id));
1758 err.span_label(span, format!("can't leak {} {}", vis_descr, kind));
1759 err.span_label(vis_span, format!("`{}` declared as {}", descr, vis_descr));
1762 let err_code = if kind == "trait" { "E0445" } else { "E0446" };
1763 self.tcx.struct_span_lint_hir(
1764 lint::builtin::PRIVATE_IN_PUBLIC,
1768 lint.build(&format!("{} (error {})", make_msg(), err_code)).emit();
1777 /// An item is 'leaked' from a private dependency if all
1778 /// of the following are true:
1779 /// 1. It's contained within a public type
1780 /// 2. It comes from a private crate
1781 fn leaks_private_dep(&self, item_id: DefId) -> bool {
1782 let ret = self.required_visibility.is_public() && self.tcx.is_private_dep(item_id.krate);
1784 tracing::debug!("leaks_private_dep(item_id={:?})={}", item_id, ret);
1789 impl<'tcx> DefIdVisitor<'tcx> for SearchInterfaceForPrivateItemsVisitor<'tcx> {
1790 fn tcx(&self) -> TyCtxt<'tcx> {
1797 descr: &dyn fmt::Display,
1798 ) -> ControlFlow<Self::BreakTy> {
1799 if self.check_def_id(def_id, kind, descr) {
1802 ControlFlow::CONTINUE
1807 struct PrivateItemsInPublicInterfacesVisitor<'tcx> {
1809 old_error_set_ancestry: LocalDefIdSet,
1812 impl<'tcx> PrivateItemsInPublicInterfacesVisitor<'tcx> {
1816 required_visibility: ty::Visibility,
1817 ) -> SearchInterfaceForPrivateItemsVisitor<'tcx> {
1818 SearchInterfaceForPrivateItemsVisitor {
1820 item_def_id: def_id,
1821 required_visibility,
1822 has_old_errors: self.old_error_set_ancestry.contains(&def_id),
1827 fn check_assoc_item(
1830 assoc_item_kind: AssocItemKind,
1831 defaultness: hir::Defaultness,
1832 vis: ty::Visibility,
1834 let mut check = self.check(def_id, vis);
1836 let (check_ty, is_assoc_ty) = match assoc_item_kind {
1837 AssocItemKind::Const | AssocItemKind::Fn { .. } => (true, false),
1838 AssocItemKind::Type => (defaultness.has_value(), true),
1840 check.in_assoc_ty = is_assoc_ty;
1841 check.generics().predicates();
1848 impl<'tcx> Visitor<'tcx> for PrivateItemsInPublicInterfacesVisitor<'tcx> {
1849 type NestedFilter = nested_filter::OnlyBodies;
1851 fn nested_visit_map(&mut self) -> Self::Map {
1855 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1857 let item_visibility = tcx.visibility(item.def_id);
1860 // Crates are always public.
1861 hir::ItemKind::ExternCrate(..) => {}
1862 // All nested items are checked by `visit_item`.
1863 hir::ItemKind::Mod(..) => {}
1864 // Checked in resolve.
1865 hir::ItemKind::Use(..) => {}
1867 hir::ItemKind::Macro(..) | hir::ItemKind::GlobalAsm(..) => {}
1868 // Subitems of these items have inherited publicity.
1869 hir::ItemKind::Const(..)
1870 | hir::ItemKind::Static(..)
1871 | hir::ItemKind::Fn(..)
1872 | hir::ItemKind::TyAlias(..) => {
1873 self.check(item.def_id, item_visibility).generics().predicates().ty();
1875 hir::ItemKind::OpaqueTy(..) => {
1876 // `ty()` for opaque types is the underlying type,
1877 // it's not a part of interface, so we skip it.
1878 self.check(item.def_id, item_visibility).generics().bounds();
1880 hir::ItemKind::Trait(.., trait_item_refs) => {
1881 self.check(item.def_id, item_visibility).generics().predicates();
1883 for trait_item_ref in trait_item_refs {
1884 self.check_assoc_item(
1885 trait_item_ref.id.def_id,
1886 trait_item_ref.kind,
1887 trait_item_ref.defaultness,
1891 if let AssocItemKind::Type = trait_item_ref.kind {
1892 self.check(trait_item_ref.id.def_id, item_visibility).bounds();
1896 hir::ItemKind::TraitAlias(..) => {
1897 self.check(item.def_id, item_visibility).generics().predicates();
1899 hir::ItemKind::Enum(ref def, _) => {
1900 self.check(item.def_id, item_visibility).generics().predicates();
1902 for variant in def.variants {
1903 for field in variant.data.fields() {
1904 self.check(self.tcx.hir().local_def_id(field.hir_id), item_visibility).ty();
1908 // Subitems of foreign modules have their own publicity.
1909 hir::ItemKind::ForeignMod { items, .. } => {
1910 for foreign_item in items {
1911 let vis = tcx.visibility(foreign_item.id.def_id);
1912 self.check(foreign_item.id.def_id, vis).generics().predicates().ty();
1915 // Subitems of structs and unions have their own publicity.
1916 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
1917 self.check(item.def_id, item_visibility).generics().predicates();
1919 for field in struct_def.fields() {
1920 let def_id = tcx.hir().local_def_id(field.hir_id);
1921 let field_visibility = tcx.visibility(def_id);
1922 self.check(def_id, min(item_visibility, field_visibility, tcx)).ty();
1925 // An inherent impl is public when its type is public
1926 // Subitems of inherent impls have their own publicity.
1927 // A trait impl is public when both its type and its trait are public
1928 // Subitems of trait impls have inherited publicity.
1929 hir::ItemKind::Impl(ref impl_) => {
1930 let impl_vis = ty::Visibility::of_impl(item.def_id, tcx, &Default::default());
1931 // check that private components do not appear in the generics or predicates of inherent impls
1932 // this check is intentionally NOT performed for impls of traits, per #90586
1933 if impl_.of_trait.is_none() {
1934 self.check(item.def_id, impl_vis).generics().predicates();
1936 for impl_item_ref in impl_.items {
1937 let impl_item_vis = if impl_.of_trait.is_none() {
1938 min(tcx.visibility(impl_item_ref.id.def_id), impl_vis, tcx)
1942 self.check_assoc_item(
1943 impl_item_ref.id.def_id,
1945 impl_item_ref.defaultness,
1954 pub fn provide(providers: &mut Providers) {
1955 *providers = Providers {
1957 privacy_access_levels,
1958 check_private_in_public,
1964 fn visibility(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Visibility {
1965 let def_id = def_id.expect_local();
1966 match tcx.resolutions(()).visibilities.get(&def_id) {
1969 let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
1970 match tcx.hir().get(hir_id) {
1971 // Unique types created for closures participate in type privacy checking.
1972 // They have visibilities inherited from the module they are defined in.
1973 Node::Expr(hir::Expr { kind: hir::ExprKind::Closure(..), .. })
1974 // - AST lowering creates dummy `use` items which don't
1975 // get their entries in the resolver's visibility table.
1976 // - AST lowering also creates opaque type items with inherited visibilities.
1977 // Visibility on them should have no effect, but to avoid the visibility
1978 // query failing on some items, we provide it for opaque types as well.
1979 | Node::Item(hir::Item {
1980 kind: hir::ItemKind::Use(_, hir::UseKind::ListStem) | hir::ItemKind::OpaqueTy(..),
1982 }) => ty::Visibility::Restricted(tcx.parent_module(hir_id).to_def_id()),
1983 // Visibilities of trait impl items are inherited from their traits
1984 // and are not filled in resolve.
1985 Node::ImplItem(impl_item) => {
1986 match tcx.hir().get_by_def_id(tcx.hir().get_parent_item(hir_id)) {
1987 Node::Item(hir::Item {
1988 kind: hir::ItemKind::Impl(hir::Impl { of_trait: Some(tr), .. }),
1990 }) => tr.path.res.opt_def_id().map_or_else(
1992 tcx.sess.delay_span_bug(tr.path.span, "trait without a def-id");
1993 ty::Visibility::Public
1995 |def_id| tcx.visibility(def_id),
1997 _ => span_bug!(impl_item.span, "the parent is not a trait impl"),
2001 tcx.def_span(def_id),
2002 "visibility table unexpectedly missing a def-id: {:?}",
2010 fn check_mod_privacy(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
2011 // Check privacy of names not checked in previous compilation stages.
2013 NamePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id };
2014 let (module, span, hir_id) = tcx.hir().get_module(module_def_id);
2016 intravisit::walk_mod(&mut visitor, module, hir_id);
2018 // Check privacy of explicitly written types and traits as well as
2019 // inferred types of expressions and patterns.
2021 TypePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id, span };
2022 intravisit::walk_mod(&mut visitor, module, hir_id);
2025 fn privacy_access_levels(tcx: TyCtxt<'_>, (): ()) -> &AccessLevels {
2026 // Build up a set of all exported items in the AST. This is a set of all
2027 // items which are reachable from external crates based on visibility.
2028 let mut visitor = EmbargoVisitor {
2030 access_levels: tcx.resolutions(()).access_levels.clone(),
2031 macro_reachable: Default::default(),
2032 prev_level: Some(AccessLevel::Public),
2037 tcx.hir().walk_toplevel_module(&mut visitor);
2038 if visitor.changed {
2039 visitor.changed = false;
2045 tcx.arena.alloc(visitor.access_levels)
2048 fn check_private_in_public(tcx: TyCtxt<'_>, (): ()) {
2049 let access_levels = tcx.privacy_access_levels(());
2051 let mut visitor = ObsoleteVisiblePrivateTypesVisitor {
2055 old_error_set: Default::default(),
2057 tcx.hir().walk_toplevel_module(&mut visitor);
2059 let mut old_error_set_ancestry = HirIdSet::default();
2060 for mut id in visitor.old_error_set.iter().copied() {
2062 if !old_error_set_ancestry.insert(id) {
2065 let parent = tcx.hir().get_parent_node(id);
2073 // Check for private types and traits in public interfaces.
2074 let mut visitor = PrivateItemsInPublicInterfacesVisitor {
2076 // Only definition IDs are ever searched in `old_error_set_ancestry`,
2077 // so we can filter away all non-definition IDs at this point.
2078 old_error_set_ancestry: old_error_set_ancestry
2080 .filter_map(|hir_id| tcx.hir().opt_local_def_id(hir_id))
2083 tcx.hir().visit_all_item_likes(&mut DeepVisitor::new(&mut visitor));