1 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
2 #![feature(control_flow_enum)]
3 #![feature(try_blocks)]
4 #![feature(associated_type_defaults)]
5 #![recursion_limit = "256"]
6 #![allow(rustc::potential_query_instability)]
8 use rustc_ast::MacroDef;
9 use rustc_attr as attr;
10 use rustc_data_structures::fx::FxHashSet;
11 use rustc_data_structures::intern::Interned;
12 use rustc_errors::struct_span_err;
14 use rustc_hir::def::{DefKind, Res};
15 use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdSet, CRATE_DEF_ID};
16 use rustc_hir::intravisit::{self, Visitor};
17 use rustc_hir::{AssocItemKind, HirIdSet, ItemId, Node, PatKind};
18 use rustc_middle::bug;
19 use rustc_middle::hir::nested_filter;
20 use rustc_middle::middle::privacy::{AccessLevel, AccessLevels};
21 use rustc_middle::span_bug;
22 use rustc_middle::thir::abstract_const::Node as ACNode;
23 use rustc_middle::ty::query::Providers;
24 use rustc_middle::ty::subst::InternalSubsts;
25 use rustc_middle::ty::{self, Const, DefIdTree, GenericParamDefKind};
26 use rustc_middle::ty::{TraitRef, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable, TypeVisitor};
27 use rustc_session::lint;
28 use rustc_span::hygiene::Transparency;
29 use rustc_span::symbol::{kw, Ident};
31 use rustc_trait_selection::traits::const_evaluatable::{self, AbstractConst};
33 use std::marker::PhantomData;
34 use std::ops::ControlFlow;
35 use std::{cmp, fmt, mem};
37 ////////////////////////////////////////////////////////////////////////////////
38 /// Generic infrastructure used to implement specific visitors below.
39 ////////////////////////////////////////////////////////////////////////////////
41 /// Implemented to visit all `DefId`s in a type.
42 /// Visiting `DefId`s is useful because visibilities and reachabilities are attached to them.
43 /// The idea is to visit "all components of a type", as documented in
44 /// <https://github.com/rust-lang/rfcs/blob/master/text/2145-type-privacy.md#how-to-determine-visibility-of-a-type>.
45 /// The default type visitor (`TypeVisitor`) does most of the job, but it has some shortcomings.
46 /// First, it doesn't have overridable `fn visit_trait_ref`, so we have to catch trait `DefId`s
47 /// manually. Second, it doesn't visit some type components like signatures of fn types, or traits
48 /// in `impl Trait`, see individual comments in `DefIdVisitorSkeleton::visit_ty`.
49 trait DefIdVisitor<'tcx> {
52 fn tcx(&self) -> TyCtxt<'tcx>;
53 fn shallow(&self) -> bool {
56 fn skip_assoc_tys(&self) -> bool {
63 descr: &dyn fmt::Display,
64 ) -> ControlFlow<Self::BreakTy>;
66 /// Not overridden, but used to actually visit types and traits.
67 fn skeleton(&mut self) -> DefIdVisitorSkeleton<'_, 'tcx, Self> {
68 DefIdVisitorSkeleton {
70 visited_opaque_tys: Default::default(),
71 dummy: Default::default(),
74 fn visit(&mut self, ty_fragment: impl TypeFoldable<'tcx>) -> ControlFlow<Self::BreakTy> {
75 ty_fragment.visit_with(&mut self.skeleton())
77 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> ControlFlow<Self::BreakTy> {
78 self.skeleton().visit_trait(trait_ref)
80 fn visit_projection_ty(
82 projection: ty::ProjectionTy<'tcx>,
83 ) -> ControlFlow<Self::BreakTy> {
84 self.skeleton().visit_projection_ty(projection)
88 predicates: ty::GenericPredicates<'tcx>,
89 ) -> ControlFlow<Self::BreakTy> {
90 self.skeleton().visit_predicates(predicates)
94 struct DefIdVisitorSkeleton<'v, 'tcx, V: ?Sized> {
95 def_id_visitor: &'v mut V,
96 visited_opaque_tys: FxHashSet<DefId>,
97 dummy: PhantomData<TyCtxt<'tcx>>,
100 impl<'tcx, V> DefIdVisitorSkeleton<'_, 'tcx, V>
102 V: DefIdVisitor<'tcx> + ?Sized,
104 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> ControlFlow<V::BreakTy> {
105 let TraitRef { def_id, substs } = trait_ref;
106 self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref.print_only_trait_path())?;
107 if self.def_id_visitor.shallow() { ControlFlow::CONTINUE } else { substs.visit_with(self) }
110 fn visit_projection_ty(
112 projection: ty::ProjectionTy<'tcx>,
113 ) -> ControlFlow<V::BreakTy> {
114 let (trait_ref, assoc_substs) =
115 projection.trait_ref_and_own_substs(self.def_id_visitor.tcx());
116 self.visit_trait(trait_ref)?;
117 if self.def_id_visitor.shallow() {
118 ControlFlow::CONTINUE
120 assoc_substs.iter().try_for_each(|subst| subst.visit_with(self))
124 fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> ControlFlow<V::BreakTy> {
125 match predicate.kind().skip_binder() {
126 ty::PredicateKind::Trait(ty::TraitPredicate {
130 }) => self.visit_trait(trait_ref),
131 ty::PredicateKind::Projection(ty::ProjectionPredicate { projection_ty, term }) => {
132 term.visit_with(self)?;
133 self.visit_projection_ty(projection_ty)
135 ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(ty, _region)) => {
138 ty::PredicateKind::RegionOutlives(..) => ControlFlow::CONTINUE,
139 ty::PredicateKind::ConstEvaluatable(uv)
140 if self.def_id_visitor.tcx().features().generic_const_exprs =>
142 let tcx = self.def_id_visitor.tcx();
143 if let Ok(Some(ct)) = AbstractConst::new(tcx, uv) {
144 self.visit_abstract_const_expr(tcx, ct)?;
146 ControlFlow::CONTINUE
148 _ => bug!("unexpected predicate: {:?}", predicate),
152 fn visit_abstract_const_expr(
155 ct: AbstractConst<'tcx>,
156 ) -> ControlFlow<V::BreakTy> {
157 const_evaluatable::walk_abstract_const(tcx, ct, |node| match node.root(tcx) {
158 ACNode::Leaf(leaf) => self.visit_const(leaf),
159 ACNode::Cast(_, _, ty) => self.visit_ty(ty),
160 ACNode::Binop(..) | ACNode::UnaryOp(..) | ACNode::FunctionCall(_, _) => {
161 ControlFlow::CONTINUE
168 predicates: ty::GenericPredicates<'tcx>,
169 ) -> ControlFlow<V::BreakTy> {
170 let ty::GenericPredicates { parent: _, predicates } = predicates;
171 predicates.iter().try_for_each(|&(predicate, _span)| self.visit_predicate(predicate))
175 impl<'tcx, V> TypeVisitor<'tcx> for DefIdVisitorSkeleton<'_, 'tcx, V>
177 V: DefIdVisitor<'tcx> + ?Sized,
179 type BreakTy = V::BreakTy;
181 fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<V::BreakTy> {
182 let tcx = self.def_id_visitor.tcx();
183 // InternalSubsts are not visited here because they are visited below
184 // 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 macro_module_def_id = self.tcx.local_parent(local_def_id);
460 if self.tcx.hir().opt_def_kind(macro_module_def_id) != Some(DefKind::Mod) {
461 // The macro's parent doesn't correspond to a `mod`, return early (#63164, #65252).
465 if self.get(local_def_id).is_none() {
469 // Since we are starting from an externally visible module,
470 // all the parents in the loop below are also guaranteed to be modules.
471 let mut module_def_id = macro_module_def_id;
473 let changed_reachability =
474 self.update_macro_reachable(module_def_id, macro_module_def_id);
475 if changed_reachability || module_def_id == CRATE_DEF_ID {
478 module_def_id = self.tcx.local_parent(module_def_id);
482 /// Updates the item as being reachable through a macro defined in the given
483 /// module. Returns `true` if the level has changed.
484 fn update_macro_reachable(
486 module_def_id: LocalDefId,
487 defining_mod: LocalDefId,
489 if self.macro_reachable.insert((module_def_id, defining_mod)) {
490 self.update_macro_reachable_mod(module_def_id, defining_mod);
497 fn update_macro_reachable_mod(&mut self, module_def_id: LocalDefId, defining_mod: LocalDefId) {
498 let module = self.tcx.hir().get_module(module_def_id).0;
499 for item_id in module.item_ids {
500 let def_kind = self.tcx.def_kind(item_id.def_id);
501 let vis = self.tcx.visibility(item_id.def_id);
502 self.update_macro_reachable_def(item_id.def_id, def_kind, vis, defining_mod);
504 if let Some(exports) = self.tcx.module_reexports(module_def_id) {
505 for export in exports {
506 if export.vis.is_accessible_from(defining_mod.to_def_id(), self.tcx) {
507 if let Res::Def(def_kind, def_id) = export.res {
508 if let Some(def_id) = def_id.as_local() {
509 let vis = self.tcx.visibility(def_id.to_def_id());
510 self.update_macro_reachable_def(def_id, def_kind, vis, defining_mod);
518 fn update_macro_reachable_def(
525 let level = Some(AccessLevel::Reachable);
527 self.update(def_id, level);
530 // No type privacy, so can be directly marked as reachable.
531 DefKind::Const | DefKind::Static(_) | DefKind::TraitAlias | DefKind::TyAlias => {
532 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
533 self.update(def_id, level);
537 // Hygiene isn't really implemented for `macro_rules!` macros at the
538 // moment. Accordingly, marking them as reachable is unwise. `macro` macros
539 // have normal hygiene, so we can treat them like other items without type
540 // privacy and mark them reachable.
541 DefKind::Macro(_) => {
542 let item = self.tcx.hir().expect_item(def_id);
543 if let hir::ItemKind::Macro(MacroDef { macro_rules: false, .. }, _) = item.kind {
544 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
545 self.update(def_id, level);
550 // We can't use a module name as the final segment of a path, except
551 // in use statements. Since re-export checking doesn't consider
552 // hygiene these don't need to be marked reachable. The contents of
553 // the module, however may be reachable.
555 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
556 self.update_macro_reachable(def_id, module);
560 DefKind::Struct | DefKind::Union => {
561 // While structs and unions have type privacy, their fields do not.
563 let item = self.tcx.hir().expect_item(def_id);
564 if let hir::ItemKind::Struct(ref struct_def, _)
565 | hir::ItemKind::Union(ref struct_def, _) = item.kind
567 for field in struct_def.fields() {
568 let def_id = self.tcx.hir().local_def_id(field.hir_id);
569 let field_vis = self.tcx.visibility(def_id);
570 if field_vis.is_accessible_from(module.to_def_id(), self.tcx) {
571 self.reach(def_id, level).ty();
575 bug!("item {:?} with DefKind {:?}", item, def_kind);
580 // These have type privacy, so are not reachable unless they're
581 // public, or are not namespaced at all.
584 | DefKind::ConstParam
585 | DefKind::Ctor(_, _)
594 | DefKind::LifetimeParam
595 | DefKind::ExternCrate
597 | DefKind::ForeignMod
599 | DefKind::InlineConst
604 | DefKind::Generator => (),
609 impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
610 type NestedFilter = nested_filter::All;
612 /// We want to visit items in the context of their containing
613 /// module and so forth, so supply a crate for doing a deep walk.
614 fn nested_visit_map(&mut self) -> Self::Map {
618 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
619 let item_level = match item.kind {
620 hir::ItemKind::Impl { .. } => {
622 Option::<AccessLevel>::of_impl(item.def_id, self.tcx, &self.access_levels);
623 self.update(item.def_id, impl_level)
625 _ => self.get(item.def_id),
628 // Update levels of nested things.
630 hir::ItemKind::Enum(ref def, _) => {
631 for variant in def.variants {
632 let variant_level = self.update_with_hir_id(variant.id, item_level);
633 if let Some(ctor_hir_id) = variant.data.ctor_hir_id() {
634 self.update_with_hir_id(ctor_hir_id, item_level);
636 for field in variant.data.fields() {
637 self.update_with_hir_id(field.hir_id, variant_level);
641 hir::ItemKind::Impl(ref impl_) => {
642 for impl_item_ref in impl_.items {
643 if impl_.of_trait.is_some()
644 || self.tcx.visibility(impl_item_ref.id.def_id) == ty::Visibility::Public
646 self.update(impl_item_ref.id.def_id, item_level);
650 hir::ItemKind::Trait(.., trait_item_refs) => {
651 for trait_item_ref in trait_item_refs {
652 self.update(trait_item_ref.id.def_id, item_level);
655 hir::ItemKind::Struct(ref def, _) | hir::ItemKind::Union(ref def, _) => {
656 if let Some(ctor_hir_id) = def.ctor_hir_id() {
657 self.update_with_hir_id(ctor_hir_id, item_level);
659 for field in def.fields() {
660 let def_id = self.tcx.hir().local_def_id(field.hir_id);
661 let vis = self.tcx.visibility(def_id);
663 self.update_with_hir_id(field.hir_id, item_level);
667 hir::ItemKind::Macro(ref macro_def, _) => {
668 self.update_reachability_from_macro(item.def_id, macro_def);
670 hir::ItemKind::ForeignMod { items, .. } => {
671 for foreign_item in items {
672 if self.tcx.visibility(foreign_item.id.def_id) == ty::Visibility::Public {
673 self.update(foreign_item.id.def_id, item_level);
678 hir::ItemKind::OpaqueTy(..)
679 | hir::ItemKind::Use(..)
680 | hir::ItemKind::Static(..)
681 | hir::ItemKind::Const(..)
682 | hir::ItemKind::GlobalAsm(..)
683 | hir::ItemKind::TyAlias(..)
684 | hir::ItemKind::Mod(..)
685 | hir::ItemKind::TraitAlias(..)
686 | hir::ItemKind::Fn(..)
687 | hir::ItemKind::ExternCrate(..) => {}
690 // Mark all items in interfaces of reachable items as reachable.
692 // The interface is empty.
693 hir::ItemKind::Macro(..) | hir::ItemKind::ExternCrate(..) => {}
694 // All nested items are checked by `visit_item`.
695 hir::ItemKind::Mod(..) => {}
696 // Handled in the access level of in rustc_resolve
697 hir::ItemKind::Use(..) => {}
698 // The interface is empty.
699 hir::ItemKind::GlobalAsm(..) => {}
700 hir::ItemKind::OpaqueTy(..) => {
701 // HACK(jynelson): trying to infer the type of `impl trait` breaks `async-std` (and `pub async fn` in general)
702 // Since rustdoc never needs to do codegen and doesn't care about link-time reachability,
703 // mark this as unreachable.
704 // See https://github.com/rust-lang/rust/issues/75100
705 if !self.tcx.sess.opts.actually_rustdoc {
706 // FIXME: This is some serious pessimization intended to workaround deficiencies
707 // in the reachability pass (`middle/reachable.rs`). Types are marked as link-time
708 // reachable if they are returned via `impl Trait`, even from private functions.
710 cmp::max(item_level, Some(AccessLevel::ReachableFromImplTrait));
711 self.reach(item.def_id, exist_level).generics().predicates().ty();
715 hir::ItemKind::Const(..)
716 | hir::ItemKind::Static(..)
717 | hir::ItemKind::Fn(..)
718 | hir::ItemKind::TyAlias(..) => {
719 if item_level.is_some() {
720 self.reach(item.def_id, item_level).generics().predicates().ty();
723 hir::ItemKind::Trait(.., trait_item_refs) => {
724 if item_level.is_some() {
725 self.reach(item.def_id, item_level).generics().predicates();
727 for trait_item_ref in trait_item_refs {
728 let mut reach = self.reach(trait_item_ref.id.def_id, item_level);
729 reach.generics().predicates();
731 if trait_item_ref.kind == AssocItemKind::Type
732 && !trait_item_ref.defaultness.has_value()
741 hir::ItemKind::TraitAlias(..) => {
742 if item_level.is_some() {
743 self.reach(item.def_id, item_level).generics().predicates();
746 // Visit everything except for private impl items.
747 hir::ItemKind::Impl(ref impl_) => {
748 if item_level.is_some() {
749 self.reach(item.def_id, item_level).generics().predicates().ty().trait_ref();
751 for impl_item_ref in impl_.items {
752 let impl_item_level = self.get(impl_item_ref.id.def_id);
753 if impl_item_level.is_some() {
754 self.reach(impl_item_ref.id.def_id, impl_item_level)
763 // Visit everything, but enum variants have their own levels.
764 hir::ItemKind::Enum(ref def, _) => {
765 if item_level.is_some() {
766 self.reach(item.def_id, item_level).generics().predicates();
768 for variant in def.variants {
769 let variant_level = self.get(self.tcx.hir().local_def_id(variant.id));
770 if variant_level.is_some() {
771 for field in variant.data.fields() {
772 self.reach(self.tcx.hir().local_def_id(field.hir_id), variant_level)
775 // Corner case: if the variant is reachable, but its
776 // enum is not, make the enum reachable as well.
777 self.reach(item.def_id, variant_level).ty();
779 if let Some(hir_id) = variant.data.ctor_hir_id() {
780 let ctor_def_id = self.tcx.hir().local_def_id(hir_id);
781 let ctor_level = self.get(ctor_def_id);
782 if ctor_level.is_some() {
783 self.reach(item.def_id, ctor_level).ty();
788 // Visit everything, but foreign items have their own levels.
789 hir::ItemKind::ForeignMod { items, .. } => {
790 for foreign_item in items {
791 let foreign_item_level = self.get(foreign_item.id.def_id);
792 if foreign_item_level.is_some() {
793 self.reach(foreign_item.id.def_id, foreign_item_level)
800 // Visit everything except for private fields.
801 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
802 if item_level.is_some() {
803 self.reach(item.def_id, item_level).generics().predicates();
804 for field in struct_def.fields() {
805 let def_id = self.tcx.hir().local_def_id(field.hir_id);
806 let field_level = self.get(def_id);
807 if field_level.is_some() {
808 self.reach(def_id, field_level).ty();
812 if let Some(hir_id) = struct_def.ctor_hir_id() {
813 let ctor_def_id = self.tcx.hir().local_def_id(hir_id);
814 let ctor_level = self.get(ctor_def_id);
815 if ctor_level.is_some() {
816 self.reach(item.def_id, ctor_level).ty();
822 let orig_level = mem::replace(&mut self.prev_level, item_level);
823 intravisit::walk_item(self, item);
824 self.prev_level = orig_level;
827 fn visit_block(&mut self, b: &'tcx hir::Block<'tcx>) {
828 // Blocks can have public items, for example impls, but they always
829 // start as completely private regardless of publicity of a function,
830 // constant, type, field, etc., in which this block resides.
831 let orig_level = mem::replace(&mut self.prev_level, None);
832 intravisit::walk_block(self, b);
833 self.prev_level = orig_level;
837 impl ReachEverythingInTheInterfaceVisitor<'_, '_> {
838 fn generics(&mut self) -> &mut Self {
839 for param in &self.ev.tcx.generics_of(self.item_def_id).params {
841 GenericParamDefKind::Lifetime => {}
842 GenericParamDefKind::Type { has_default, .. } => {
844 self.visit(self.ev.tcx.type_of(param.def_id));
847 GenericParamDefKind::Const { has_default } => {
848 self.visit(self.ev.tcx.type_of(param.def_id));
850 self.visit(self.ev.tcx.const_param_default(param.def_id));
858 fn predicates(&mut self) -> &mut Self {
859 self.visit_predicates(self.ev.tcx.predicates_of(self.item_def_id));
863 fn ty(&mut self) -> &mut Self {
864 self.visit(self.ev.tcx.type_of(self.item_def_id));
868 fn trait_ref(&mut self) -> &mut Self {
869 if let Some(trait_ref) = self.ev.tcx.impl_trait_ref(self.item_def_id) {
870 self.visit_trait(trait_ref);
876 impl<'tcx> DefIdVisitor<'tcx> for ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
877 fn tcx(&self) -> TyCtxt<'tcx> {
884 _descr: &dyn fmt::Display,
885 ) -> ControlFlow<Self::BreakTy> {
886 if let Some(def_id) = def_id.as_local() {
887 if let (ty::Visibility::Public, _) | (_, Some(AccessLevel::ReachableFromImplTrait)) =
888 (self.tcx().visibility(def_id.to_def_id()), self.access_level)
890 self.ev.update(def_id, self.access_level);
893 ControlFlow::CONTINUE
897 //////////////////////////////////////////////////////////////////////////////////////
898 /// Name privacy visitor, checks privacy and reports violations.
899 /// Most of name privacy checks are performed during the main resolution phase,
900 /// or later in type checking when field accesses and associated items are resolved.
901 /// This pass performs remaining checks for fields in struct expressions and patterns.
902 //////////////////////////////////////////////////////////////////////////////////////
904 struct NamePrivacyVisitor<'tcx> {
906 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
907 current_item: LocalDefId,
910 impl<'tcx> NamePrivacyVisitor<'tcx> {
911 /// Gets the type-checking results for the current body.
912 /// As this will ICE if called outside bodies, only call when working with
913 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
915 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
916 self.maybe_typeck_results
917 .expect("`NamePrivacyVisitor::typeck_results` called outside of body")
920 // Checks that a field in a struct constructor (expression or pattern) is accessible.
923 use_ctxt: Span, // syntax context of the field name at the use site
924 span: Span, // span of the field pattern, e.g., `x: 0`
925 def: ty::AdtDef<'tcx>, // definition of the struct or enum
926 field: &'tcx ty::FieldDef,
927 in_update_syntax: bool,
933 // definition of the field
934 let ident = Ident::new(kw::Empty, use_ctxt);
935 let hir_id = self.tcx.hir().local_def_id_to_hir_id(self.current_item);
936 let def_id = self.tcx.adjust_ident_and_get_scope(ident, def.did(), hir_id).1;
937 if !field.vis.is_accessible_from(def_id, self.tcx) {
938 let label = if in_update_syntax {
939 format!("field `{}` is private", field.name)
941 "private field".to_string()
948 "field `{}` of {} `{}` is private",
951 self.tcx.def_path_str(def.did())
953 .span_label(span, label)
959 impl<'tcx> Visitor<'tcx> for NamePrivacyVisitor<'tcx> {
960 type NestedFilter = nested_filter::All;
962 /// We want to visit items in the context of their containing
963 /// module and so forth, so supply a crate for doing a deep walk.
964 fn nested_visit_map(&mut self) -> Self::Map {
968 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
969 // Don't visit nested modules, since we run a separate visitor walk
970 // for each module in `privacy_access_levels`
973 fn visit_nested_body(&mut self, body: hir::BodyId) {
974 let old_maybe_typeck_results =
975 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
976 let body = self.tcx.hir().body(body);
977 self.visit_body(body);
978 self.maybe_typeck_results = old_maybe_typeck_results;
981 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
982 let orig_current_item = mem::replace(&mut self.current_item, item.def_id);
983 intravisit::walk_item(self, item);
984 self.current_item = orig_current_item;
987 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
988 if let hir::ExprKind::Struct(qpath, fields, ref base) = expr.kind {
989 let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
990 let adt = self.typeck_results().expr_ty(expr).ty_adt_def().unwrap();
991 let variant = adt.variant_of_res(res);
992 if let Some(base) = *base {
993 // If the expression uses FRU we need to make sure all the unmentioned fields
994 // are checked for privacy (RFC 736). Rather than computing the set of
995 // unmentioned fields, just check them all.
996 for (vf_index, variant_field) in variant.fields.iter().enumerate() {
997 let field = fields.iter().find(|f| {
998 self.tcx.field_index(f.hir_id, self.typeck_results()) == vf_index
1000 let (use_ctxt, span) = match field {
1001 Some(field) => (field.ident.span, field.span),
1002 None => (base.span, base.span),
1004 self.check_field(use_ctxt, span, adt, variant_field, true);
1007 for field in fields {
1008 let use_ctxt = field.ident.span;
1009 let index = self.tcx.field_index(field.hir_id, self.typeck_results());
1010 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1015 intravisit::walk_expr(self, expr);
1018 fn visit_pat(&mut self, pat: &'tcx hir::Pat<'tcx>) {
1019 if let PatKind::Struct(ref qpath, fields, _) = pat.kind {
1020 let res = self.typeck_results().qpath_res(qpath, pat.hir_id);
1021 let adt = self.typeck_results().pat_ty(pat).ty_adt_def().unwrap();
1022 let variant = adt.variant_of_res(res);
1023 for field in fields {
1024 let use_ctxt = field.ident.span;
1025 let index = self.tcx.field_index(field.hir_id, self.typeck_results());
1026 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1030 intravisit::walk_pat(self, pat);
1034 ////////////////////////////////////////////////////////////////////////////////////////////
1035 /// Type privacy visitor, checks types for privacy and reports violations.
1036 /// Both explicitly written types and inferred types of expressions and patterns are checked.
1037 /// Checks are performed on "semantic" types regardless of names and their hygiene.
1038 ////////////////////////////////////////////////////////////////////////////////////////////
1040 struct TypePrivacyVisitor<'tcx> {
1042 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
1043 current_item: LocalDefId,
1047 impl<'tcx> TypePrivacyVisitor<'tcx> {
1048 /// Gets the type-checking results for the current body.
1049 /// As this will ICE if called outside bodies, only call when working with
1050 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
1052 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
1053 self.maybe_typeck_results
1054 .expect("`TypePrivacyVisitor::typeck_results` called outside of body")
1057 fn item_is_accessible(&self, did: DefId) -> bool {
1058 self.tcx.visibility(did).is_accessible_from(self.current_item.to_def_id(), self.tcx)
1061 // Take node-id of an expression or pattern and check its type for privacy.
1062 fn check_expr_pat_type(&mut self, id: hir::HirId, span: Span) -> bool {
1064 let typeck_results = self.typeck_results();
1065 let result: ControlFlow<()> = try {
1066 self.visit(typeck_results.node_type(id))?;
1067 self.visit(typeck_results.node_substs(id))?;
1068 if let Some(adjustments) = typeck_results.adjustments().get(id) {
1069 adjustments.iter().try_for_each(|adjustment| self.visit(adjustment.target))?;
1075 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1076 let is_error = !self.item_is_accessible(def_id);
1080 .struct_span_err(self.span, &format!("{} `{}` is private", kind, descr))
1081 .span_label(self.span, &format!("private {}", kind))
1088 impl<'tcx> Visitor<'tcx> for TypePrivacyVisitor<'tcx> {
1089 type NestedFilter = nested_filter::All;
1091 /// We want to visit items in the context of their containing
1092 /// module and so forth, so supply a crate for doing a deep walk.
1093 fn nested_visit_map(&mut self) -> Self::Map {
1097 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
1098 // Don't visit nested modules, since we run a separate visitor walk
1099 // for each module in `privacy_access_levels`
1102 fn visit_nested_body(&mut self, body: hir::BodyId) {
1103 let old_maybe_typeck_results =
1104 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
1105 let body = self.tcx.hir().body(body);
1106 self.visit_body(body);
1107 self.maybe_typeck_results = old_maybe_typeck_results;
1110 fn visit_generic_arg(&mut self, generic_arg: &'tcx hir::GenericArg<'tcx>) {
1112 hir::GenericArg::Type(t) => self.visit_ty(t),
1113 hir::GenericArg::Infer(inf) => self.visit_infer(inf),
1114 hir::GenericArg::Lifetime(_) | hir::GenericArg::Const(_) => {}
1118 fn visit_ty(&mut self, hir_ty: &'tcx hir::Ty<'tcx>) {
1119 self.span = hir_ty.span;
1120 if let Some(typeck_results) = self.maybe_typeck_results {
1122 if self.visit(typeck_results.node_type(hir_ty.hir_id)).is_break() {
1126 // Types in signatures.
1127 // FIXME: This is very ineffective. Ideally each HIR type should be converted
1128 // into a semantic type only once and the result should be cached somehow.
1129 if self.visit(rustc_typeck::hir_ty_to_ty(self.tcx, hir_ty)).is_break() {
1134 intravisit::walk_ty(self, hir_ty);
1137 fn visit_infer(&mut self, inf: &'tcx hir::InferArg) {
1138 self.span = inf.span;
1139 if let Some(typeck_results) = self.maybe_typeck_results {
1140 if let Some(ty) = typeck_results.node_type_opt(inf.hir_id) {
1141 if self.visit(ty).is_break() {
1145 // We don't do anything for const infers here.
1148 bug!("visit_infer without typeck_results");
1150 intravisit::walk_inf(self, inf);
1153 fn visit_trait_ref(&mut self, trait_ref: &'tcx hir::TraitRef<'tcx>) {
1154 self.span = trait_ref.path.span;
1155 if self.maybe_typeck_results.is_none() {
1156 // Avoid calling `hir_trait_to_predicates` in bodies, it will ICE.
1157 // The traits' privacy in bodies is already checked as a part of trait object types.
1158 let bounds = rustc_typeck::hir_trait_to_predicates(
1161 // NOTE: This isn't really right, but the actual type doesn't matter here. It's
1162 // just required by `ty::TraitRef`.
1163 self.tcx.types.never,
1166 for (trait_predicate, _, _) in bounds.trait_bounds {
1167 if self.visit_trait(trait_predicate.skip_binder()).is_break() {
1172 for (poly_predicate, _) in bounds.projection_bounds {
1173 let pred = poly_predicate.skip_binder();
1174 let poly_pred_term = self.visit(pred.term);
1175 if poly_pred_term.is_break()
1176 || self.visit_projection_ty(pred.projection_ty).is_break()
1183 intravisit::walk_trait_ref(self, trait_ref);
1186 // Check types of expressions
1187 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
1188 if self.check_expr_pat_type(expr.hir_id, expr.span) {
1189 // Do not check nested expressions if the error already happened.
1193 hir::ExprKind::Assign(_, rhs, _) | hir::ExprKind::Match(rhs, ..) => {
1194 // Do not report duplicate errors for `x = y` and `match x { ... }`.
1195 if self.check_expr_pat_type(rhs.hir_id, rhs.span) {
1199 hir::ExprKind::MethodCall(segment, ..) => {
1200 // Method calls have to be checked specially.
1201 self.span = segment.ident.span;
1202 if let Some(def_id) = self.typeck_results().type_dependent_def_id(expr.hir_id) {
1203 if self.visit(self.tcx.type_of(def_id)).is_break() {
1209 .delay_span_bug(expr.span, "no type-dependent def for method call");
1215 intravisit::walk_expr(self, expr);
1218 // Prohibit access to associated items with insufficient nominal visibility.
1220 // Additionally, until better reachability analysis for macros 2.0 is available,
1221 // we prohibit access to private statics from other crates, this allows to give
1222 // more code internal visibility at link time. (Access to private functions
1223 // is already prohibited by type privacy for function types.)
1224 fn visit_qpath(&mut self, qpath: &'tcx hir::QPath<'tcx>, id: hir::HirId, span: Span) {
1225 let def = match qpath {
1226 hir::QPath::Resolved(_, path) => match path.res {
1227 Res::Def(kind, def_id) => Some((kind, def_id)),
1230 hir::QPath::TypeRelative(..) | hir::QPath::LangItem(..) => self
1231 .maybe_typeck_results
1232 .and_then(|typeck_results| typeck_results.type_dependent_def(id)),
1234 let def = def.filter(|(kind, _)| {
1237 DefKind::AssocFn | DefKind::AssocConst | DefKind::AssocTy | DefKind::Static(_)
1240 if let Some((kind, def_id)) = def {
1241 let is_local_static =
1242 if let DefKind::Static(_) = kind { def_id.is_local() } else { false };
1243 if !self.item_is_accessible(def_id) && !is_local_static {
1244 let sess = self.tcx.sess;
1245 let sm = sess.source_map();
1246 let name = match qpath {
1247 hir::QPath::Resolved(..) | hir::QPath::LangItem(..) => {
1248 sm.span_to_snippet(qpath.span()).ok()
1250 hir::QPath::TypeRelative(_, segment) => Some(segment.ident.to_string()),
1252 let kind = kind.descr(def_id);
1253 let msg = match name {
1254 Some(name) => format!("{} `{}` is private", kind, name),
1255 None => format!("{} is private", kind),
1257 sess.struct_span_err(span, &msg)
1258 .span_label(span, &format!("private {}", kind))
1264 intravisit::walk_qpath(self, qpath, id, span);
1267 // Check types of patterns.
1268 fn visit_pat(&mut self, pattern: &'tcx hir::Pat<'tcx>) {
1269 if self.check_expr_pat_type(pattern.hir_id, pattern.span) {
1270 // Do not check nested patterns if the error already happened.
1274 intravisit::walk_pat(self, pattern);
1277 fn visit_local(&mut self, local: &'tcx hir::Local<'tcx>) {
1278 if let Some(init) = local.init {
1279 if self.check_expr_pat_type(init.hir_id, init.span) {
1280 // Do not report duplicate errors for `let x = y`.
1285 intravisit::walk_local(self, local);
1288 // Check types in item interfaces.
1289 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1290 let orig_current_item = mem::replace(&mut self.current_item, item.def_id);
1291 let old_maybe_typeck_results = self.maybe_typeck_results.take();
1292 intravisit::walk_item(self, item);
1293 self.maybe_typeck_results = old_maybe_typeck_results;
1294 self.current_item = orig_current_item;
1298 impl<'tcx> DefIdVisitor<'tcx> for TypePrivacyVisitor<'tcx> {
1299 fn tcx(&self) -> TyCtxt<'tcx> {
1306 descr: &dyn fmt::Display,
1307 ) -> ControlFlow<Self::BreakTy> {
1308 if self.check_def_id(def_id, kind, descr) {
1311 ControlFlow::CONTINUE
1316 ///////////////////////////////////////////////////////////////////////////////
1317 /// Obsolete visitors for checking for private items in public interfaces.
1318 /// These visitors are supposed to be kept in frozen state and produce an
1319 /// "old error node set". For backward compatibility the new visitor reports
1320 /// warnings instead of hard errors when the erroneous node is not in this old set.
1321 ///////////////////////////////////////////////////////////////////////////////
1323 struct ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1325 access_levels: &'a AccessLevels,
1327 // Set of errors produced by this obsolete visitor.
1328 old_error_set: HirIdSet,
1331 struct ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1332 inner: &'a ObsoleteVisiblePrivateTypesVisitor<'b, 'tcx>,
1333 /// Whether the type refers to private types.
1334 contains_private: bool,
1335 /// Whether we've recurred at all (i.e., if we're pointing at the
1336 /// first type on which `visit_ty` was called).
1337 at_outer_type: bool,
1338 /// Whether that first type is a public path.
1339 outer_type_is_public_path: bool,
1342 impl<'a, 'tcx> ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1343 fn path_is_private_type(&self, path: &hir::Path<'_>) -> bool {
1344 let did = match path.res {
1345 Res::PrimTy(..) | Res::SelfTy { .. } | Res::Err => return false,
1346 res => res.def_id(),
1349 // A path can only be private if:
1350 // it's in this crate...
1351 if let Some(did) = did.as_local() {
1352 // .. and it corresponds to a private type in the AST (this returns
1353 // `None` for type parameters).
1354 match self.tcx.hir().find(self.tcx.hir().local_def_id_to_hir_id(did)) {
1355 Some(Node::Item(_)) => !self.tcx.visibility(did).is_public(),
1356 Some(_) | None => false,
1363 fn trait_is_public(&self, trait_id: LocalDefId) -> bool {
1364 // FIXME: this would preferably be using `exported_items`, but all
1365 // traits are exported currently (see `EmbargoVisitor.exported_trait`).
1366 self.access_levels.is_public(trait_id)
1369 fn check_generic_bound(&mut self, bound: &hir::GenericBound<'_>) {
1370 if let hir::GenericBound::Trait(ref trait_ref, _) = *bound {
1371 if self.path_is_private_type(trait_ref.trait_ref.path) {
1372 self.old_error_set.insert(trait_ref.trait_ref.hir_ref_id);
1377 fn item_is_public(&self, def_id: LocalDefId) -> bool {
1378 self.access_levels.is_reachable(def_id) || self.tcx.visibility(def_id).is_public()
1382 impl<'a, 'b, 'tcx, 'v> Visitor<'v> for ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1383 fn visit_generic_arg(&mut self, generic_arg: &'v hir::GenericArg<'v>) {
1385 hir::GenericArg::Type(t) => self.visit_ty(t),
1386 hir::GenericArg::Infer(inf) => self.visit_ty(&inf.to_ty()),
1387 hir::GenericArg::Lifetime(_) | hir::GenericArg::Const(_) => {}
1391 fn visit_ty(&mut self, ty: &hir::Ty<'_>) {
1392 if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = ty.kind {
1393 if self.inner.path_is_private_type(path) {
1394 self.contains_private = true;
1395 // Found what we're looking for, so let's stop working.
1399 if let hir::TyKind::Path(_) = ty.kind {
1400 if self.at_outer_type {
1401 self.outer_type_is_public_path = true;
1404 self.at_outer_type = false;
1405 intravisit::walk_ty(self, ty)
1408 // Don't want to recurse into `[, .. expr]`.
1409 fn visit_expr(&mut self, _: &hir::Expr<'_>) {}
1412 impl<'a, 'tcx> Visitor<'tcx> for ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1413 type NestedFilter = nested_filter::All;
1415 /// We want to visit items in the context of their containing
1416 /// module and so forth, so supply a crate for doing a deep walk.
1417 fn nested_visit_map(&mut self) -> Self::Map {
1421 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1423 // Contents of a private mod can be re-exported, so we need
1424 // to check internals.
1425 hir::ItemKind::Mod(_) => {}
1427 // An `extern {}` doesn't introduce a new privacy
1428 // namespace (the contents have their own privacies).
1429 hir::ItemKind::ForeignMod { .. } => {}
1431 hir::ItemKind::Trait(.., bounds, _) => {
1432 if !self.trait_is_public(item.def_id) {
1436 for bound in bounds.iter() {
1437 self.check_generic_bound(bound)
1441 // Impls need some special handling to try to offer useful
1442 // error messages without (too many) false positives
1443 // (i.e., we could just return here to not check them at
1444 // all, or some worse estimation of whether an impl is
1445 // publicly visible).
1446 hir::ItemKind::Impl(ref impl_) => {
1447 // `impl [... for] Private` is never visible.
1448 let self_contains_private;
1449 // `impl [... for] Public<...>`, but not `impl [... for]
1450 // Vec<Public>` or `(Public,)`, etc.
1451 let self_is_public_path;
1453 // Check the properties of the `Self` type:
1455 let mut visitor = ObsoleteCheckTypeForPrivatenessVisitor {
1457 contains_private: false,
1458 at_outer_type: true,
1459 outer_type_is_public_path: false,
1461 visitor.visit_ty(impl_.self_ty);
1462 self_contains_private = visitor.contains_private;
1463 self_is_public_path = visitor.outer_type_is_public_path;
1466 // Miscellaneous info about the impl:
1468 // `true` iff this is `impl Private for ...`.
1469 let not_private_trait = impl_.of_trait.as_ref().map_or(
1470 true, // no trait counts as public trait
1472 if let Some(def_id) = tr.path.res.def_id().as_local() {
1473 self.trait_is_public(def_id)
1475 true // external traits must be public
1480 // `true` iff this is a trait impl or at least one method is public.
1482 // `impl Public { $( fn ...() {} )* }` is not visible.
1484 // This is required over just using the methods' privacy
1485 // directly because we might have `impl<T: Foo<Private>> ...`,
1486 // and we shouldn't warn about the generics if all the methods
1487 // are private (because `T` won't be visible externally).
1488 let trait_or_some_public_method = impl_.of_trait.is_some()
1489 || impl_.items.iter().any(|impl_item_ref| {
1490 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1491 match impl_item.kind {
1492 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..) => {
1493 self.access_levels.is_reachable(impl_item_ref.id.def_id)
1495 hir::ImplItemKind::TyAlias(_) => false,
1499 if !self_contains_private && not_private_trait && trait_or_some_public_method {
1500 intravisit::walk_generics(self, &impl_.generics);
1502 match impl_.of_trait {
1504 for impl_item_ref in impl_.items {
1505 // This is where we choose whether to walk down
1506 // further into the impl to check its items. We
1507 // should only walk into public items so that we
1508 // don't erroneously report errors for private
1509 // types in private items.
1510 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1511 match impl_item.kind {
1512 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..)
1513 if self.item_is_public(impl_item.def_id) =>
1515 intravisit::walk_impl_item(self, impl_item)
1517 hir::ImplItemKind::TyAlias(..) => {
1518 intravisit::walk_impl_item(self, impl_item)
1525 // Any private types in a trait impl fall into three
1527 // 1. mentioned in the trait definition
1528 // 2. mentioned in the type params/generics
1529 // 3. mentioned in the associated types of the impl
1531 // Those in 1. can only occur if the trait is in
1532 // this crate and will have been warned about on the
1533 // trait definition (there's no need to warn twice
1534 // so we don't check the methods).
1536 // Those in 2. are warned via walk_generics and this
1538 intravisit::walk_path(self, tr.path);
1540 // Those in 3. are warned with this call.
1541 for impl_item_ref in impl_.items {
1542 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1543 if let hir::ImplItemKind::TyAlias(ty) = impl_item.kind {
1549 } else if impl_.of_trait.is_none() && self_is_public_path {
1550 // `impl Public<Private> { ... }`. Any public static
1551 // methods will be visible as `Public::foo`.
1552 let mut found_pub_static = false;
1553 for impl_item_ref in impl_.items {
1554 if self.access_levels.is_reachable(impl_item_ref.id.def_id)
1555 || self.tcx.visibility(impl_item_ref.id.def_id)
1556 == ty::Visibility::Public
1558 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1559 match impl_item_ref.kind {
1560 AssocItemKind::Const => {
1561 found_pub_static = true;
1562 intravisit::walk_impl_item(self, impl_item);
1564 AssocItemKind::Fn { has_self: false } => {
1565 found_pub_static = true;
1566 intravisit::walk_impl_item(self, impl_item);
1572 if found_pub_static {
1573 intravisit::walk_generics(self, &impl_.generics)
1579 // `type ... = ...;` can contain private types, because
1580 // we're introducing a new name.
1581 hir::ItemKind::TyAlias(..) => return,
1583 // Not at all public, so we don't care.
1584 _ if !self.item_is_public(item.def_id) => {
1591 // We've carefully constructed it so that if we're here, then
1592 // any `visit_ty`'s will be called on things that are in
1593 // public signatures, i.e., things that we're interested in for
1595 intravisit::walk_item(self, item);
1598 fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
1599 for predicate in generics.predicates {
1601 hir::WherePredicate::BoundPredicate(bound_pred) => {
1602 for bound in bound_pred.bounds.iter() {
1603 self.check_generic_bound(bound)
1606 hir::WherePredicate::RegionPredicate(_) => {}
1607 hir::WherePredicate::EqPredicate(eq_pred) => {
1608 self.visit_ty(eq_pred.rhs_ty);
1614 fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem<'tcx>) {
1615 if self.access_levels.is_reachable(item.def_id) {
1616 intravisit::walk_foreign_item(self, item)
1620 fn visit_ty(&mut self, t: &'tcx hir::Ty<'tcx>) {
1621 if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = t.kind {
1622 if self.path_is_private_type(path) {
1623 self.old_error_set.insert(t.hir_id);
1626 intravisit::walk_ty(self, t)
1631 v: &'tcx hir::Variant<'tcx>,
1632 g: &'tcx hir::Generics<'tcx>,
1633 item_id: hir::HirId,
1635 if self.access_levels.is_reachable(self.tcx.hir().local_def_id(v.id)) {
1636 self.in_variant = true;
1637 intravisit::walk_variant(self, v, g, item_id);
1638 self.in_variant = false;
1642 fn visit_field_def(&mut self, s: &'tcx hir::FieldDef<'tcx>) {
1643 let def_id = self.tcx.hir().local_def_id(s.hir_id);
1644 let vis = self.tcx.visibility(def_id);
1645 if vis.is_public() || self.in_variant {
1646 intravisit::walk_field_def(self, s);
1650 // We don't need to introspect into these at all: an
1651 // expression/block context can't possibly contain exported things.
1652 // (Making them no-ops stops us from traversing the whole AST without
1653 // having to be super careful about our `walk_...` calls above.)
1654 fn visit_block(&mut self, _: &'tcx hir::Block<'tcx>) {}
1655 fn visit_expr(&mut self, _: &'tcx hir::Expr<'tcx>) {}
1658 ///////////////////////////////////////////////////////////////////////////////
1659 /// SearchInterfaceForPrivateItemsVisitor traverses an item's interface and
1660 /// finds any private components in it.
1661 /// PrivateItemsInPublicInterfacesVisitor ensures there are no private types
1662 /// and traits in public interfaces.
1663 ///////////////////////////////////////////////////////////////////////////////
1665 struct SearchInterfaceForPrivateItemsVisitor<'tcx> {
1667 item_def_id: LocalDefId,
1668 /// The visitor checks that each component type is at least this visible.
1669 required_visibility: ty::Visibility,
1670 has_old_errors: bool,
1674 impl SearchInterfaceForPrivateItemsVisitor<'_> {
1675 fn generics(&mut self) -> &mut Self {
1676 for param in &self.tcx.generics_of(self.item_def_id).params {
1678 GenericParamDefKind::Lifetime => {}
1679 GenericParamDefKind::Type { has_default, .. } => {
1681 self.visit(self.tcx.type_of(param.def_id));
1684 // FIXME(generic_const_exprs): May want to look inside const here
1685 GenericParamDefKind::Const { .. } => {
1686 self.visit(self.tcx.type_of(param.def_id));
1693 fn predicates(&mut self) -> &mut Self {
1694 // N.B., we use `explicit_predicates_of` and not `predicates_of`
1695 // because we don't want to report privacy errors due to where
1696 // clauses that the compiler inferred. We only want to
1697 // consider the ones that the user wrote. This is important
1698 // for the inferred outlives rules; see
1699 // `src/test/ui/rfc-2093-infer-outlives/privacy.rs`.
1700 self.visit_predicates(self.tcx.explicit_predicates_of(self.item_def_id));
1704 fn bounds(&mut self) -> &mut Self {
1705 self.visit_predicates(ty::GenericPredicates {
1707 predicates: self.tcx.explicit_item_bounds(self.item_def_id),
1712 fn ty(&mut self) -> &mut Self {
1713 self.visit(self.tcx.type_of(self.item_def_id));
1717 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1718 if self.leaks_private_dep(def_id) {
1719 self.tcx.struct_span_lint_hir(
1720 lint::builtin::EXPORTED_PRIVATE_DEPENDENCIES,
1721 self.tcx.hir().local_def_id_to_hir_id(self.item_def_id),
1722 self.tcx.def_span(self.item_def_id.to_def_id()),
1724 lint.build(&format!(
1725 "{} `{}` from private dependency '{}' in public \
1729 self.tcx.crate_name(def_id.krate)
1736 let hir_id = match def_id.as_local() {
1737 Some(def_id) => self.tcx.hir().local_def_id_to_hir_id(def_id),
1738 None => return false,
1741 let vis = self.tcx.visibility(def_id);
1742 if !vis.is_at_least(self.required_visibility, self.tcx) {
1743 let vis_descr = match vis {
1744 ty::Visibility::Public => "public",
1745 ty::Visibility::Invisible => "private",
1746 ty::Visibility::Restricted(vis_def_id) => {
1747 if vis_def_id == self.tcx.parent_module(hir_id).to_def_id() {
1749 } else if vis_def_id.is_top_level_module() {
1756 let make_msg = || format!("{} {} `{}` in public interface", vis_descr, kind, descr);
1757 let span = self.tcx.def_span(self.item_def_id.to_def_id());
1758 if self.has_old_errors
1760 || self.tcx.resolutions(()).has_pub_restricted
1762 let mut err = if kind == "trait" {
1763 struct_span_err!(self.tcx.sess, span, E0445, "{}", make_msg())
1765 struct_span_err!(self.tcx.sess, span, E0446, "{}", make_msg())
1768 self.tcx.sess.source_map().guess_head_span(self.tcx.def_span(def_id));
1769 err.span_label(span, format!("can't leak {} {}", vis_descr, kind));
1770 err.span_label(vis_span, format!("`{}` declared as {}", descr, vis_descr));
1773 let err_code = if kind == "trait" { "E0445" } else { "E0446" };
1774 self.tcx.struct_span_lint_hir(
1775 lint::builtin::PRIVATE_IN_PUBLIC,
1779 lint.build(&format!("{} (error {})", make_msg(), err_code)).emit();
1788 /// An item is 'leaked' from a private dependency if all
1789 /// of the following are true:
1790 /// 1. It's contained within a public type
1791 /// 2. It comes from a private crate
1792 fn leaks_private_dep(&self, item_id: DefId) -> bool {
1793 let ret = self.required_visibility.is_public() && self.tcx.is_private_dep(item_id.krate);
1795 tracing::debug!("leaks_private_dep(item_id={:?})={}", item_id, ret);
1800 impl<'tcx> DefIdVisitor<'tcx> for SearchInterfaceForPrivateItemsVisitor<'tcx> {
1801 fn tcx(&self) -> TyCtxt<'tcx> {
1808 descr: &dyn fmt::Display,
1809 ) -> ControlFlow<Self::BreakTy> {
1810 if self.check_def_id(def_id, kind, descr) {
1813 ControlFlow::CONTINUE
1818 struct PrivateItemsInPublicInterfacesChecker<'tcx> {
1820 old_error_set_ancestry: LocalDefIdSet,
1823 impl<'tcx> PrivateItemsInPublicInterfacesChecker<'tcx> {
1827 required_visibility: ty::Visibility,
1828 ) -> SearchInterfaceForPrivateItemsVisitor<'tcx> {
1829 SearchInterfaceForPrivateItemsVisitor {
1831 item_def_id: def_id,
1832 required_visibility,
1833 has_old_errors: self.old_error_set_ancestry.contains(&def_id),
1838 fn check_assoc_item(
1841 assoc_item_kind: AssocItemKind,
1842 defaultness: hir::Defaultness,
1843 vis: ty::Visibility,
1845 let mut check = self.check(def_id, vis);
1847 let (check_ty, is_assoc_ty) = match assoc_item_kind {
1848 AssocItemKind::Const | AssocItemKind::Fn { .. } => (true, false),
1849 AssocItemKind::Type => (defaultness.has_value(), true),
1851 check.in_assoc_ty = is_assoc_ty;
1852 check.generics().predicates();
1858 pub fn check_item(&mut self, id: ItemId) {
1860 let item_visibility = tcx.visibility(id.def_id);
1861 let def_kind = tcx.def_kind(id.def_id);
1864 DefKind::Const | DefKind::Static(_) | DefKind::Fn | DefKind::TyAlias => {
1865 self.check(id.def_id, item_visibility).generics().predicates().ty();
1867 DefKind::OpaqueTy => {
1868 // `ty()` for opaque types is the underlying type,
1869 // it's not a part of interface, so we skip it.
1870 self.check(id.def_id, item_visibility).generics().bounds();
1873 let item = tcx.hir().item(id);
1874 if let hir::ItemKind::Trait(.., trait_item_refs) = item.kind {
1875 self.check(item.def_id, item_visibility).generics().predicates();
1877 for trait_item_ref in trait_item_refs {
1878 self.check_assoc_item(
1879 trait_item_ref.id.def_id,
1880 trait_item_ref.kind,
1881 trait_item_ref.defaultness,
1885 if let AssocItemKind::Type = trait_item_ref.kind {
1886 self.check(trait_item_ref.id.def_id, item_visibility).bounds();
1891 DefKind::TraitAlias => {
1892 self.check(id.def_id, item_visibility).generics().predicates();
1895 let item = tcx.hir().item(id);
1896 if let hir::ItemKind::Enum(ref def, _) = item.kind {
1897 self.check(item.def_id, item_visibility).generics().predicates();
1899 for variant in def.variants {
1900 for field in variant.data.fields() {
1901 self.check(self.tcx.hir().local_def_id(field.hir_id), item_visibility)
1907 // Subitems of foreign modules have their own publicity.
1908 DefKind::ForeignMod => {
1909 let item = tcx.hir().item(id);
1910 if let hir::ItemKind::ForeignMod { items, .. } = item.kind {
1911 for foreign_item in items {
1912 let vis = tcx.visibility(foreign_item.id.def_id);
1913 self.check(foreign_item.id.def_id, vis).generics().predicates().ty();
1917 // Subitems of structs and unions have their own publicity.
1918 DefKind::Struct | DefKind::Union => {
1919 let item = tcx.hir().item(id);
1920 if let hir::ItemKind::Struct(ref struct_def, _)
1921 | hir::ItemKind::Union(ref struct_def, _) = item.kind
1923 self.check(item.def_id, item_visibility).generics().predicates();
1925 for field in struct_def.fields() {
1926 let def_id = tcx.hir().local_def_id(field.hir_id);
1927 let field_visibility = tcx.visibility(def_id);
1928 self.check(def_id, min(item_visibility, field_visibility, tcx)).ty();
1932 // An inherent impl is public when its type is public
1933 // Subitems of inherent impls have their own publicity.
1934 // A trait impl is public when both its type and its trait are public
1935 // Subitems of trait impls have inherited publicity.
1937 let item = tcx.hir().item(id);
1938 if let hir::ItemKind::Impl(ref impl_) = item.kind {
1939 let impl_vis = ty::Visibility::of_impl(item.def_id, tcx, &Default::default());
1940 // check that private components do not appear in the generics or predicates of inherent impls
1941 // this check is intentionally NOT performed for impls of traits, per #90586
1942 if impl_.of_trait.is_none() {
1943 self.check(item.def_id, impl_vis).generics().predicates();
1945 for impl_item_ref in impl_.items {
1946 let impl_item_vis = if impl_.of_trait.is_none() {
1947 min(tcx.visibility(impl_item_ref.id.def_id), impl_vis, tcx)
1951 self.check_assoc_item(
1952 impl_item_ref.id.def_id,
1954 impl_item_ref.defaultness,
1965 pub fn provide(providers: &mut Providers) {
1966 *providers = Providers {
1968 privacy_access_levels,
1969 check_private_in_public,
1975 fn visibility(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Visibility {
1976 let def_id = def_id.expect_local();
1977 match tcx.resolutions(()).visibilities.get(&def_id) {
1980 let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
1981 match tcx.hir().get(hir_id) {
1982 // Unique types created for closures participate in type privacy checking.
1983 // They have visibilities inherited from the module they are defined in.
1984 Node::Expr(hir::Expr { kind: hir::ExprKind::Closure(..), .. })
1985 // - AST lowering creates dummy `use` items which don't
1986 // get their entries in the resolver's visibility table.
1987 // - AST lowering also creates opaque type items with inherited visibilities.
1988 // Visibility on them should have no effect, but to avoid the visibility
1989 // query failing on some items, we provide it for opaque types as well.
1990 | Node::Item(hir::Item {
1991 kind: hir::ItemKind::Use(_, hir::UseKind::ListStem) | hir::ItemKind::OpaqueTy(..),
1993 }) => ty::Visibility::Restricted(tcx.parent_module(hir_id).to_def_id()),
1994 // Visibilities of trait impl items are inherited from their traits
1995 // and are not filled in resolve.
1996 Node::ImplItem(impl_item) => {
1997 match tcx.hir().get_by_def_id(tcx.hir().get_parent_item(hir_id)) {
1998 Node::Item(hir::Item {
1999 kind: hir::ItemKind::Impl(hir::Impl { of_trait: Some(tr), .. }),
2001 }) => tr.path.res.opt_def_id().map_or_else(
2003 tcx.sess.delay_span_bug(tr.path.span, "trait without a def-id");
2004 ty::Visibility::Public
2006 |def_id| tcx.visibility(def_id),
2008 _ => span_bug!(impl_item.span, "the parent is not a trait impl"),
2012 tcx.def_span(def_id),
2013 "visibility table unexpectedly missing a def-id: {:?}",
2021 fn check_mod_privacy(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
2022 // Check privacy of names not checked in previous compilation stages.
2024 NamePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id };
2025 let (module, span, hir_id) = tcx.hir().get_module(module_def_id);
2027 intravisit::walk_mod(&mut visitor, module, hir_id);
2029 // Check privacy of explicitly written types and traits as well as
2030 // inferred types of expressions and patterns.
2032 TypePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id, span };
2033 intravisit::walk_mod(&mut visitor, module, hir_id);
2036 fn privacy_access_levels(tcx: TyCtxt<'_>, (): ()) -> &AccessLevels {
2037 // Build up a set of all exported items in the AST. This is a set of all
2038 // items which are reachable from external crates based on visibility.
2039 let mut visitor = EmbargoVisitor {
2041 access_levels: tcx.resolutions(()).access_levels.clone(),
2042 macro_reachable: Default::default(),
2043 prev_level: Some(AccessLevel::Public),
2048 tcx.hir().walk_toplevel_module(&mut visitor);
2049 if visitor.changed {
2050 visitor.changed = false;
2056 tcx.arena.alloc(visitor.access_levels)
2059 fn check_private_in_public(tcx: TyCtxt<'_>, (): ()) {
2060 let access_levels = tcx.privacy_access_levels(());
2062 let mut visitor = ObsoleteVisiblePrivateTypesVisitor {
2066 old_error_set: Default::default(),
2068 tcx.hir().walk_toplevel_module(&mut visitor);
2070 let mut old_error_set_ancestry = HirIdSet::default();
2071 for mut id in visitor.old_error_set.iter().copied() {
2073 if !old_error_set_ancestry.insert(id) {
2076 let parent = tcx.hir().get_parent_node(id);
2084 // Check for private types and traits in public interfaces.
2085 let mut checker = PrivateItemsInPublicInterfacesChecker {
2087 // Only definition IDs are ever searched in `old_error_set_ancestry`,
2088 // so we can filter away all non-definition IDs at this point.
2089 old_error_set_ancestry: old_error_set_ancestry
2091 .filter_map(|hir_id| tcx.hir().opt_local_def_id(hir_id))
2095 for id in tcx.hir().items() {
2096 checker.check_item(id);