1 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
2 #![feature(in_band_lifetimes)]
4 #![feature(or_patterns)]
5 #![recursion_limit = "256"]
7 use rustc_attr as attr;
8 use rustc_data_structures::fx::FxHashSet;
9 use rustc_errors::struct_span_err;
11 use rustc_hir::def::{DefKind, Res};
12 use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
13 use rustc_hir::intravisit::{self, DeepVisitor, NestedVisitorMap, Visitor};
14 use rustc_hir::{AssocItemKind, HirIdSet, Node, PatKind};
15 use rustc_middle::bug;
16 use rustc_middle::hir::map::Map;
17 use rustc_middle::middle::privacy::{AccessLevel, AccessLevels};
18 use rustc_middle::ty::fold::TypeVisitor;
19 use rustc_middle::ty::query::Providers;
20 use rustc_middle::ty::subst::InternalSubsts;
21 use rustc_middle::ty::{self, GenericParamDefKind, TraitRef, Ty, TyCtxt, TypeFoldable};
22 use rustc_session::lint;
23 use rustc_span::hygiene::Transparency;
24 use rustc_span::symbol::{kw, sym, Ident};
27 use std::marker::PhantomData;
28 use std::{cmp, fmt, mem};
30 ////////////////////////////////////////////////////////////////////////////////
31 /// Generic infrastructure used to implement specific visitors below.
32 ////////////////////////////////////////////////////////////////////////////////
34 /// Implemented to visit all `DefId`s in a type.
35 /// Visiting `DefId`s is useful because visibilities and reachabilities are attached to them.
36 /// The idea is to visit "all components of a type", as documented in
37 /// https://github.com/rust-lang/rfcs/blob/master/text/2145-type-privacy.md#how-to-determine-visibility-of-a-type.
38 /// The default type visitor (`TypeVisitor`) does most of the job, but it has some shortcomings.
39 /// First, it doesn't have overridable `fn visit_trait_ref`, so we have to catch trait `DefId`s
40 /// manually. Second, it doesn't visit some type components like signatures of fn types, or traits
41 /// in `impl Trait`, see individual comments in `DefIdVisitorSkeleton::visit_ty`.
42 trait DefIdVisitor<'tcx> {
43 fn tcx(&self) -> TyCtxt<'tcx>;
44 fn shallow(&self) -> bool {
47 fn skip_assoc_tys(&self) -> bool {
50 fn visit_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool;
52 /// Not overridden, but used to actually visit types and traits.
53 fn skeleton(&mut self) -> DefIdVisitorSkeleton<'_, 'tcx, Self> {
54 DefIdVisitorSkeleton {
56 visited_opaque_tys: Default::default(),
57 dummy: Default::default(),
60 fn visit(&mut self, ty_fragment: impl TypeFoldable<'tcx>) -> bool {
61 ty_fragment.visit_with(&mut self.skeleton())
63 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> bool {
64 self.skeleton().visit_trait(trait_ref)
66 fn visit_predicates(&mut self, predicates: ty::GenericPredicates<'tcx>) -> bool {
67 self.skeleton().visit_predicates(predicates)
71 struct DefIdVisitorSkeleton<'v, 'tcx, V: ?Sized> {
72 def_id_visitor: &'v mut V,
73 visited_opaque_tys: FxHashSet<DefId>,
74 dummy: PhantomData<TyCtxt<'tcx>>,
77 impl<'tcx, V> DefIdVisitorSkeleton<'_, 'tcx, V>
79 V: DefIdVisitor<'tcx> + ?Sized,
81 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> bool {
82 let TraitRef { def_id, substs } = trait_ref;
83 self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref.print_only_trait_path())
84 || (!self.def_id_visitor.shallow() && substs.visit_with(self))
87 fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> bool {
88 match predicate.kind() {
89 &ty::PredicateKind::ForAll(pred) => {
90 // This visitor does not care about bound regions as we only
92 self.visit_predicate(pred.skip_binder())
94 &ty::PredicateKind::Trait(ty::TraitPredicate { trait_ref }, _) => {
95 self.visit_trait(trait_ref)
97 &ty::PredicateKind::Projection(ty::ProjectionPredicate { projection_ty, ty }) => {
99 || self.visit_trait(projection_ty.trait_ref(self.def_id_visitor.tcx()))
101 &ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(ty, _region)) => {
104 ty::PredicateKind::RegionOutlives(..) => false,
105 _ => bug!("unexpected predicate: {:?}", predicate),
109 fn visit_predicates(&mut self, predicates: ty::GenericPredicates<'tcx>) -> bool {
110 let ty::GenericPredicates { parent: _, predicates } = predicates;
111 for &(predicate, _span) in predicates {
112 if self.visit_predicate(predicate) {
120 impl<'tcx, V> TypeVisitor<'tcx> for DefIdVisitorSkeleton<'_, 'tcx, V>
122 V: DefIdVisitor<'tcx> + ?Sized,
124 fn visit_ty(&mut self, ty: Ty<'tcx>) -> bool {
125 let tcx = self.def_id_visitor.tcx();
126 // InternalSubsts are not visited here because they are visited below in `super_visit_with`.
128 ty::Adt(&ty::AdtDef { did: def_id, .. }, ..)
129 | ty::Foreign(def_id)
130 | ty::FnDef(def_id, ..)
131 | ty::Closure(def_id, ..)
132 | ty::Generator(def_id, ..) => {
133 if self.def_id_visitor.visit_def_id(def_id, "type", &ty) {
136 if self.def_id_visitor.shallow() {
139 // Default type visitor doesn't visit signatures of fn types.
140 // Something like `fn() -> Priv {my_func}` is considered a private type even if
141 // `my_func` is public, so we need to visit signatures.
142 if let ty::FnDef(..) = ty.kind {
143 if tcx.fn_sig(def_id).visit_with(self) {
147 // Inherent static methods don't have self type in substs.
148 // Something like `fn() {my_method}` type of the method
149 // `impl Pub<Priv> { pub fn my_method() {} }` is considered a private type,
150 // so we need to visit the self type additionally.
151 if let Some(assoc_item) = tcx.opt_associated_item(def_id) {
152 if let ty::ImplContainer(impl_def_id) = assoc_item.container {
153 if tcx.type_of(impl_def_id).visit_with(self) {
159 ty::Projection(proj) => {
160 if self.def_id_visitor.skip_assoc_tys() {
161 // Visitors searching for minimal visibility/reachability want to
162 // conservatively approximate associated types like `<Type as Trait>::Alias`
163 // as visible/reachable even if both `Type` and `Trait` are private.
164 // Ideally, associated types should be substituted in the same way as
165 // free type aliases, but this isn't done yet.
168 // This will also visit substs if necessary, so we don't need to recurse.
169 return self.visit_trait(proj.trait_ref(tcx));
171 ty::Dynamic(predicates, ..) => {
172 // All traits in the list are considered the "primary" part of the type
173 // and are visited by shallow visitors.
174 for predicate in predicates.skip_binder() {
175 let trait_ref = match predicate {
176 ty::ExistentialPredicate::Trait(trait_ref) => trait_ref,
177 ty::ExistentialPredicate::Projection(proj) => proj.trait_ref(tcx),
178 ty::ExistentialPredicate::AutoTrait(def_id) => {
179 ty::ExistentialTraitRef { def_id, substs: InternalSubsts::empty() }
182 let ty::ExistentialTraitRef { def_id, substs: _ } = trait_ref;
183 if self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref) {
188 ty::Opaque(def_id, ..) => {
189 // Skip repeated `Opaque`s to avoid infinite recursion.
190 if self.visited_opaque_tys.insert(def_id) {
191 // The intent is to treat `impl Trait1 + Trait2` identically to
192 // `dyn Trait1 + Trait2`. Therefore we ignore def-id of the opaque type itself
193 // (it either has no visibility, or its visibility is insignificant, like
194 // visibilities of type aliases) and recurse into predicates instead to go
195 // through the trait list (default type visitor doesn't visit those traits).
196 // All traits in the list are considered the "primary" part of the type
197 // and are visited by shallow visitors.
198 if self.visit_predicates(tcx.predicates_of(def_id)) {
203 // These types don't have their own def-ids (but may have subcomponents
204 // with def-ids that should be visited recursively).
220 | ty::GeneratorWitness(..) => {}
221 ty::Bound(..) | ty::Placeholder(..) | ty::Infer(..) => {
222 bug!("unexpected type: {:?}", ty)
226 !self.def_id_visitor.shallow() && ty.super_visit_with(self)
230 fn def_id_visibility<'tcx>(
233 ) -> (ty::Visibility, Span, &'static str) {
234 match def_id.as_local().map(|def_id| tcx.hir().as_local_hir_id(def_id)) {
236 let vis = match tcx.hir().get(hir_id) {
237 Node::Item(item) => &item.vis,
238 Node::ForeignItem(foreign_item) => &foreign_item.vis,
239 Node::MacroDef(macro_def) => {
240 if attr::contains_name(¯o_def.attrs, sym::macro_export) {
241 return (ty::Visibility::Public, macro_def.span, "public");
246 Node::TraitItem(..) | Node::Variant(..) => {
247 return def_id_visibility(tcx, tcx.hir().get_parent_did(hir_id).to_def_id());
249 Node::ImplItem(impl_item) => {
250 match tcx.hir().get(tcx.hir().get_parent_item(hir_id)) {
251 Node::Item(item) => match &item.kind {
252 hir::ItemKind::Impl { of_trait: None, .. } => &impl_item.vis,
253 hir::ItemKind::Impl { of_trait: Some(trait_ref), .. } => {
254 return def_id_visibility(tcx, trait_ref.path.res.def_id());
256 kind => bug!("unexpected item kind: {:?}", kind),
258 node => bug!("unexpected node kind: {:?}", node),
261 Node::Ctor(vdata) => {
262 let parent_hir_id = tcx.hir().get_parent_node(hir_id);
263 match tcx.hir().get(parent_hir_id) {
264 Node::Variant(..) => {
265 let parent_did = tcx.hir().local_def_id(parent_hir_id);
266 let (mut ctor_vis, mut span, mut descr) =
267 def_id_visibility(tcx, parent_did.to_def_id());
269 let adt_def = tcx.adt_def(tcx.hir().get_parent_did(hir_id).to_def_id());
270 let ctor_did = tcx.hir().local_def_id(vdata.ctor_hir_id().unwrap());
271 let variant = adt_def.variant_with_ctor_id(ctor_did.to_def_id());
273 if variant.is_field_list_non_exhaustive()
274 && ctor_vis == ty::Visibility::Public
277 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
278 let attrs = tcx.get_attrs(variant.def_id);
280 attr::find_by_name(&attrs, sym::non_exhaustive).unwrap().span;
281 descr = "crate-visible";
284 return (ctor_vis, span, descr);
287 let item = match tcx.hir().get(parent_hir_id) {
288 Node::Item(item) => item,
289 node => bug!("unexpected node kind: {:?}", node),
291 let (mut ctor_vis, mut span, mut descr) = (
292 ty::Visibility::from_hir(&item.vis, parent_hir_id, tcx),
294 item.vis.node.descr(),
296 for field in vdata.fields() {
297 let field_vis = ty::Visibility::from_hir(&field.vis, hir_id, tcx);
298 if ctor_vis.is_at_least(field_vis, tcx) {
299 ctor_vis = field_vis;
300 span = field.vis.span;
301 descr = field.vis.node.descr();
305 // If the structure is marked as non_exhaustive then lower the
306 // visibility to within the crate.
307 if ctor_vis == ty::Visibility::Public {
309 tcx.adt_def(tcx.hir().get_parent_did(hir_id).to_def_id());
310 if adt_def.non_enum_variant().is_field_list_non_exhaustive() {
312 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
313 span = attr::find_by_name(&item.attrs, sym::non_exhaustive)
316 descr = "crate-visible";
320 return (ctor_vis, span, descr);
322 node => bug!("unexpected node kind: {:?}", node),
325 Node::Expr(expr) => {
327 ty::Visibility::Restricted(tcx.parent_module(expr.hir_id).to_def_id()),
332 node => bug!("unexpected node kind: {:?}", node),
334 (ty::Visibility::from_hir(vis, hir_id, tcx), vis.span, vis.node.descr())
337 let vis = tcx.visibility(def_id);
338 let descr = if vis == ty::Visibility::Public { "public" } else { "private" };
339 (vis, tcx.def_span(def_id), descr)
344 fn min(vis1: ty::Visibility, vis2: ty::Visibility, tcx: TyCtxt<'_>) -> ty::Visibility {
345 if vis1.is_at_least(vis2, tcx) { vis2 } else { vis1 }
348 ////////////////////////////////////////////////////////////////////////////////
349 /// Visitor used to determine if pub(restricted) is used anywhere in the crate.
351 /// This is done so that `private_in_public` warnings can be turned into hard errors
352 /// in crates that have been updated to use pub(restricted).
353 ////////////////////////////////////////////////////////////////////////////////
354 struct PubRestrictedVisitor<'tcx> {
356 has_pub_restricted: bool,
359 impl Visitor<'tcx> for PubRestrictedVisitor<'tcx> {
360 type Map = Map<'tcx>;
362 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
363 NestedVisitorMap::All(self.tcx.hir())
365 fn visit_vis(&mut self, vis: &'tcx hir::Visibility<'tcx>) {
366 self.has_pub_restricted = self.has_pub_restricted || vis.node.is_pub_restricted();
370 ////////////////////////////////////////////////////////////////////////////////
371 /// Visitor used to determine impl visibility and reachability.
372 ////////////////////////////////////////////////////////////////////////////////
374 struct FindMin<'a, 'tcx, VL: VisibilityLike> {
376 access_levels: &'a AccessLevels,
380 impl<'a, 'tcx, VL: VisibilityLike> DefIdVisitor<'tcx> for FindMin<'a, 'tcx, VL> {
381 fn tcx(&self) -> TyCtxt<'tcx> {
384 fn shallow(&self) -> bool {
387 fn skip_assoc_tys(&self) -> bool {
390 fn visit_def_id(&mut self, def_id: DefId, _kind: &str, _descr: &dyn fmt::Display) -> bool {
391 self.min = VL::new_min(self, def_id);
396 trait VisibilityLike: Sized {
398 const SHALLOW: bool = false;
399 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self;
401 // Returns an over-approximation (`skip_assoc_tys` = true) of visibility due to
402 // associated types for which we can't determine visibility precisely.
403 fn of_impl(hir_id: hir::HirId, tcx: TyCtxt<'_>, access_levels: &AccessLevels) -> Self {
404 let mut find = FindMin { tcx, access_levels, min: Self::MAX };
405 let def_id = tcx.hir().local_def_id(hir_id);
406 find.visit(tcx.type_of(def_id));
407 if let Some(trait_ref) = tcx.impl_trait_ref(def_id) {
408 find.visit_trait(trait_ref);
413 impl VisibilityLike for ty::Visibility {
414 const MAX: Self = ty::Visibility::Public;
415 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
416 min(def_id_visibility(find.tcx, def_id).0, find.min, find.tcx)
419 impl VisibilityLike for Option<AccessLevel> {
420 const MAX: Self = Some(AccessLevel::Public);
421 // Type inference is very smart sometimes.
422 // It can make an impl reachable even some components of its type or trait are unreachable.
423 // E.g. methods of `impl ReachableTrait<UnreachableTy> for ReachableTy<UnreachableTy> { ... }`
424 // can be usable from other crates (#57264). So we skip substs when calculating reachability
425 // and consider an impl reachable if its "shallow" type and trait are reachable.
427 // The assumption we make here is that type-inference won't let you use an impl without knowing
428 // both "shallow" version of its self type and "shallow" version of its trait if it exists
429 // (which require reaching the `DefId`s in them).
430 const SHALLOW: bool = true;
431 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
433 if let Some(def_id) = def_id.as_local() {
434 let hir_id = find.tcx.hir().as_local_hir_id(def_id);
435 find.access_levels.map.get(&hir_id).cloned()
444 ////////////////////////////////////////////////////////////////////////////////
445 /// The embargo visitor, used to determine the exports of the AST.
446 ////////////////////////////////////////////////////////////////////////////////
448 struct EmbargoVisitor<'tcx> {
451 /// Accessibility levels for reachable nodes.
452 access_levels: AccessLevels,
453 /// A set of pairs corresponding to modules, where the first module is
454 /// reachable via a macro that's defined in the second module. This cannot
455 /// be represented as reachable because it can't handle the following case:
457 /// pub mod n { // Should be `Public`
458 /// pub(crate) mod p { // Should *not* be accessible
459 /// pub fn f() -> i32 { 12 } // Must be `Reachable`
465 macro_reachable: FxHashSet<(hir::HirId, DefId)>,
466 /// Previous accessibility level; `None` means unreachable.
467 prev_level: Option<AccessLevel>,
468 /// Has something changed in the level map?
472 struct ReachEverythingInTheInterfaceVisitor<'a, 'tcx> {
473 access_level: Option<AccessLevel>,
475 ev: &'a mut EmbargoVisitor<'tcx>,
478 impl EmbargoVisitor<'tcx> {
479 fn get(&self, id: hir::HirId) -> Option<AccessLevel> {
480 self.access_levels.map.get(&id).cloned()
483 /// Updates node level and returns the updated level.
484 fn update(&mut self, id: hir::HirId, level: Option<AccessLevel>) -> Option<AccessLevel> {
485 let old_level = self.get(id);
486 // Accessibility levels can only grow.
487 if level > old_level {
488 self.access_levels.map.insert(id, level.unwrap());
499 access_level: Option<AccessLevel>,
500 ) -> ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
501 ReachEverythingInTheInterfaceVisitor {
502 access_level: cmp::min(access_level, Some(AccessLevel::Reachable)),
503 item_def_id: self.tcx.hir().local_def_id(item_id).to_def_id(),
508 /// Updates the item as being reachable through a macro defined in the given
509 /// module. Returns `true` if the level has changed.
510 fn update_macro_reachable(&mut self, reachable_mod: hir::HirId, defining_mod: DefId) -> bool {
511 if self.macro_reachable.insert((reachable_mod, defining_mod)) {
512 self.update_macro_reachable_mod(reachable_mod, defining_mod);
519 fn update_macro_reachable_mod(&mut self, reachable_mod: hir::HirId, defining_mod: DefId) {
520 let module_def_id = self.tcx.hir().local_def_id(reachable_mod);
521 let module = self.tcx.hir().get_module(module_def_id).0;
522 for item_id in module.item_ids {
523 let hir_id = item_id.id;
524 let item_def_id = self.tcx.hir().local_def_id(hir_id);
525 let def_kind = self.tcx.def_kind(item_def_id);
526 let item = self.tcx.hir().expect_item(hir_id);
527 let vis = ty::Visibility::from_hir(&item.vis, hir_id, self.tcx);
528 self.update_macro_reachable_def(hir_id, def_kind, vis, defining_mod);
530 if let Some(exports) = self.tcx.module_exports(module_def_id) {
531 for export in exports {
532 if export.vis.is_accessible_from(defining_mod, self.tcx) {
533 if let Res::Def(def_kind, def_id) = export.res {
534 let vis = def_id_visibility(self.tcx, def_id).0;
535 if let Some(def_id) = def_id.as_local() {
536 let hir_id = self.tcx.hir().as_local_hir_id(def_id);
537 self.update_macro_reachable_def(hir_id, def_kind, vis, defining_mod);
545 fn update_macro_reachable_def(
552 let level = Some(AccessLevel::Reachable);
553 if let ty::Visibility::Public = vis {
554 self.update(hir_id, level);
557 // No type privacy, so can be directly marked as reachable.
561 | DefKind::TraitAlias
562 | DefKind::TyAlias => {
563 if vis.is_accessible_from(module, self.tcx) {
564 self.update(hir_id, level);
568 // We can't use a module name as the final segment of a path, except
569 // in use statements. Since re-export checking doesn't consider
570 // hygiene these don't need to be marked reachable. The contents of
571 // the module, however may be reachable.
573 if vis.is_accessible_from(module, self.tcx) {
574 self.update_macro_reachable(hir_id, module);
578 DefKind::Struct | DefKind::Union => {
579 // While structs and unions have type privacy, their fields do
581 if let ty::Visibility::Public = vis {
582 let item = self.tcx.hir().expect_item(hir_id);
583 if let hir::ItemKind::Struct(ref struct_def, _)
584 | hir::ItemKind::Union(ref struct_def, _) = item.kind
586 for field in struct_def.fields() {
588 ty::Visibility::from_hir(&field.vis, field.hir_id, self.tcx);
589 if field_vis.is_accessible_from(module, self.tcx) {
590 self.reach(field.hir_id, level).ty();
594 bug!("item {:?} with DefKind {:?}", item, def_kind);
599 // These have type privacy, so are not reachable unless they're
600 // public, or are not namespaced at all.
603 | DefKind::ConstParam
604 | DefKind::Ctor(_, _)
613 | DefKind::LifetimeParam
614 | DefKind::ExternCrate
616 | DefKind::ForeignMod
622 | DefKind::Generator => (),
626 /// Given the path segments of a `ItemKind::Use`, then we need
627 /// to update the visibility of the intermediate use so that it isn't linted
628 /// by `unreachable_pub`.
630 /// This isn't trivial as `path.res` has the `DefId` of the eventual target
631 /// of the use statement not of the next intermediate use statement.
633 /// To do this, consider the last two segments of the path to our intermediate
634 /// use statement. We expect the penultimate segment to be a module and the
635 /// last segment to be the name of the item we are exporting. We can then
636 /// look at the items contained in the module for the use statement with that
637 /// name and update that item's visibility.
639 /// FIXME: This solution won't work with glob imports and doesn't respect
640 /// namespaces. See <https://github.com/rust-lang/rust/pull/57922#discussion_r251234202>.
641 fn update_visibility_of_intermediate_use_statements(
643 segments: &[hir::PathSegment<'_>],
645 if let Some([module, segment]) = segments.rchunks_exact(2).next() {
646 if let Some(item) = module
648 .and_then(|res| res.mod_def_id())
649 // If the module is `self`, i.e. the current crate,
650 // there will be no corresponding item.
651 .filter(|def_id| def_id.index != CRATE_DEF_INDEX || def_id.krate != LOCAL_CRATE)
653 def_id.as_local().map(|def_id| self.tcx.hir().as_local_hir_id(def_id))
655 .map(|module_hir_id| self.tcx.hir().expect_item(module_hir_id))
657 if let hir::ItemKind::Mod(m) = &item.kind {
658 for item_id in m.item_ids {
659 let item = self.tcx.hir().expect_item(item_id.id);
660 let def_id = self.tcx.hir().local_def_id(item_id.id);
661 if !self.tcx.hygienic_eq(segment.ident, item.ident, def_id.to_def_id()) {
664 if let hir::ItemKind::Use(..) = item.kind {
665 self.update(item.hir_id, Some(AccessLevel::Exported));
674 impl Visitor<'tcx> for EmbargoVisitor<'tcx> {
675 type Map = Map<'tcx>;
677 /// We want to visit items in the context of their containing
678 /// module and so forth, so supply a crate for doing a deep walk.
679 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
680 NestedVisitorMap::All(self.tcx.hir())
683 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
684 let inherited_item_level = match item.kind {
685 hir::ItemKind::Impl { .. } => {
686 Option::<AccessLevel>::of_impl(item.hir_id, self.tcx, &self.access_levels)
688 // Foreign modules inherit level from parents.
689 hir::ItemKind::ForeignMod(..) => self.prev_level,
690 // Other `pub` items inherit levels from parents.
691 hir::ItemKind::Const(..)
692 | hir::ItemKind::Enum(..)
693 | hir::ItemKind::ExternCrate(..)
694 | hir::ItemKind::GlobalAsm(..)
695 | hir::ItemKind::Fn(..)
696 | hir::ItemKind::Mod(..)
697 | hir::ItemKind::Static(..)
698 | hir::ItemKind::Struct(..)
699 | hir::ItemKind::Trait(..)
700 | hir::ItemKind::TraitAlias(..)
701 | hir::ItemKind::OpaqueTy(..)
702 | hir::ItemKind::TyAlias(..)
703 | hir::ItemKind::Union(..)
704 | hir::ItemKind::Use(..) => {
705 if item.vis.node.is_pub() {
713 // Update level of the item itself.
714 let item_level = self.update(item.hir_id, inherited_item_level);
716 // Update levels of nested things.
718 hir::ItemKind::Enum(ref def, _) => {
719 for variant in def.variants {
720 let variant_level = self.update(variant.id, item_level);
721 if let Some(ctor_hir_id) = variant.data.ctor_hir_id() {
722 self.update(ctor_hir_id, item_level);
724 for field in variant.data.fields() {
725 self.update(field.hir_id, variant_level);
729 hir::ItemKind::Impl { ref of_trait, items, .. } => {
730 for impl_item_ref in items {
731 if of_trait.is_some() || impl_item_ref.vis.node.is_pub() {
732 self.update(impl_item_ref.id.hir_id, item_level);
736 hir::ItemKind::Trait(.., trait_item_refs) => {
737 for trait_item_ref in trait_item_refs {
738 self.update(trait_item_ref.id.hir_id, item_level);
741 hir::ItemKind::Struct(ref def, _) | hir::ItemKind::Union(ref def, _) => {
742 if let Some(ctor_hir_id) = def.ctor_hir_id() {
743 self.update(ctor_hir_id, item_level);
745 for field in def.fields() {
746 if field.vis.node.is_pub() {
747 self.update(field.hir_id, item_level);
751 hir::ItemKind::ForeignMod(ref foreign_mod) => {
752 for foreign_item in foreign_mod.items {
753 if foreign_item.vis.node.is_pub() {
754 self.update(foreign_item.hir_id, item_level);
758 hir::ItemKind::OpaqueTy(..)
759 | hir::ItemKind::Use(..)
760 | hir::ItemKind::Static(..)
761 | hir::ItemKind::Const(..)
762 | hir::ItemKind::GlobalAsm(..)
763 | hir::ItemKind::TyAlias(..)
764 | hir::ItemKind::Mod(..)
765 | hir::ItemKind::TraitAlias(..)
766 | hir::ItemKind::Fn(..)
767 | hir::ItemKind::ExternCrate(..) => {}
770 // Mark all items in interfaces of reachable items as reachable.
772 // The interface is empty.
773 hir::ItemKind::ExternCrate(..) => {}
774 // All nested items are checked by `visit_item`.
775 hir::ItemKind::Mod(..) => {}
776 // Re-exports are handled in `visit_mod`. However, in order to avoid looping over
777 // all of the items of a mod in `visit_mod` looking for use statements, we handle
778 // making sure that intermediate use statements have their visibilities updated here.
779 hir::ItemKind::Use(ref path, _) => {
780 if item_level.is_some() {
781 self.update_visibility_of_intermediate_use_statements(path.segments.as_ref());
784 // The interface is empty.
785 hir::ItemKind::GlobalAsm(..) => {}
786 hir::ItemKind::OpaqueTy(..) => {
787 // FIXME: This is some serious pessimization intended to workaround deficiencies
788 // in the reachability pass (`middle/reachable.rs`). Types are marked as link-time
789 // reachable if they are returned via `impl Trait`, even from private functions.
790 let exist_level = cmp::max(item_level, Some(AccessLevel::ReachableFromImplTrait));
791 self.reach(item.hir_id, exist_level).generics().predicates().ty();
794 hir::ItemKind::Const(..)
795 | hir::ItemKind::Static(..)
796 | hir::ItemKind::Fn(..)
797 | hir::ItemKind::TyAlias(..) => {
798 if item_level.is_some() {
799 self.reach(item.hir_id, item_level).generics().predicates().ty();
802 hir::ItemKind::Trait(.., trait_item_refs) => {
803 if item_level.is_some() {
804 self.reach(item.hir_id, item_level).generics().predicates();
806 for trait_item_ref in trait_item_refs {
807 let mut reach = self.reach(trait_item_ref.id.hir_id, item_level);
808 reach.generics().predicates();
810 if trait_item_ref.kind == AssocItemKind::Type
811 && !trait_item_ref.defaultness.has_value()
820 hir::ItemKind::TraitAlias(..) => {
821 if item_level.is_some() {
822 self.reach(item.hir_id, item_level).generics().predicates();
825 // Visit everything except for private impl items.
826 hir::ItemKind::Impl { items, .. } => {
827 if item_level.is_some() {
828 self.reach(item.hir_id, item_level).generics().predicates().ty().trait_ref();
830 for impl_item_ref in items {
831 let impl_item_level = self.get(impl_item_ref.id.hir_id);
832 if impl_item_level.is_some() {
833 self.reach(impl_item_ref.id.hir_id, impl_item_level)
842 // Visit everything, but enum variants have their own levels.
843 hir::ItemKind::Enum(ref def, _) => {
844 if item_level.is_some() {
845 self.reach(item.hir_id, item_level).generics().predicates();
847 for variant in def.variants {
848 let variant_level = self.get(variant.id);
849 if variant_level.is_some() {
850 for field in variant.data.fields() {
851 self.reach(field.hir_id, variant_level).ty();
853 // Corner case: if the variant is reachable, but its
854 // enum is not, make the enum reachable as well.
855 self.update(item.hir_id, variant_level);
859 // Visit everything, but foreign items have their own levels.
860 hir::ItemKind::ForeignMod(ref foreign_mod) => {
861 for foreign_item in foreign_mod.items {
862 let foreign_item_level = self.get(foreign_item.hir_id);
863 if foreign_item_level.is_some() {
864 self.reach(foreign_item.hir_id, foreign_item_level)
871 // Visit everything except for private fields.
872 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
873 if item_level.is_some() {
874 self.reach(item.hir_id, item_level).generics().predicates();
875 for field in struct_def.fields() {
876 let field_level = self.get(field.hir_id);
877 if field_level.is_some() {
878 self.reach(field.hir_id, field_level).ty();
885 let orig_level = mem::replace(&mut self.prev_level, item_level);
886 intravisit::walk_item(self, item);
887 self.prev_level = orig_level;
890 fn visit_block(&mut self, b: &'tcx hir::Block<'tcx>) {
891 // Blocks can have public items, for example impls, but they always
892 // start as completely private regardless of publicity of a function,
893 // constant, type, field, etc., in which this block resides.
894 let orig_level = mem::replace(&mut self.prev_level, None);
895 intravisit::walk_block(self, b);
896 self.prev_level = orig_level;
899 fn visit_mod(&mut self, m: &'tcx hir::Mod<'tcx>, _sp: Span, id: hir::HirId) {
900 // This code is here instead of in visit_item so that the
901 // crate module gets processed as well.
902 if self.prev_level.is_some() {
903 let def_id = self.tcx.hir().local_def_id(id);
904 if let Some(exports) = self.tcx.module_exports(def_id) {
905 for export in exports.iter() {
906 if export.vis == ty::Visibility::Public {
907 if let Some(def_id) = export.res.opt_def_id() {
908 if let Some(def_id) = def_id.as_local() {
909 let hir_id = self.tcx.hir().as_local_hir_id(def_id);
910 self.update(hir_id, Some(AccessLevel::Exported));
918 intravisit::walk_mod(self, m, id);
921 fn visit_macro_def(&mut self, md: &'tcx hir::MacroDef<'tcx>) {
922 if attr::find_transparency(&md.attrs, md.ast.macro_rules).0 != Transparency::Opaque {
923 self.update(md.hir_id, Some(AccessLevel::Public));
927 let macro_module_def_id =
928 ty::DefIdTree::parent(self.tcx, self.tcx.hir().local_def_id(md.hir_id).to_def_id())
930 // FIXME(#71104) Should really be using just `as_local_hir_id` but
931 // some `DefId` do not seem to have a corresponding HirId.
932 let hir_id = macro_module_def_id
934 .and_then(|def_id| self.tcx.hir().opt_local_def_id_to_hir_id(def_id));
935 let mut module_id = match hir_id {
936 Some(module_id) if self.tcx.hir().is_hir_id_module(module_id) => module_id,
937 // `module_id` doesn't correspond to a `mod`, return early (#63164, #65252).
940 let level = if md.vis.node.is_pub() { self.get(module_id) } else { None };
941 let new_level = self.update(md.hir_id, level);
942 if new_level.is_none() {
947 let changed_reachability = self.update_macro_reachable(module_id, macro_module_def_id);
948 if changed_reachability || module_id == hir::CRATE_HIR_ID {
951 module_id = self.tcx.hir().get_parent_node(module_id);
956 impl ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
957 fn generics(&mut self) -> &mut Self {
958 for param in &self.ev.tcx.generics_of(self.item_def_id).params {
960 GenericParamDefKind::Lifetime => {}
961 GenericParamDefKind::Type { has_default, .. } => {
963 self.visit(self.ev.tcx.type_of(param.def_id));
966 GenericParamDefKind::Const => {
967 self.visit(self.ev.tcx.type_of(param.def_id));
974 fn predicates(&mut self) -> &mut Self {
975 self.visit_predicates(self.ev.tcx.predicates_of(self.item_def_id));
979 fn ty(&mut self) -> &mut Self {
980 self.visit(self.ev.tcx.type_of(self.item_def_id));
984 fn trait_ref(&mut self) -> &mut Self {
985 if let Some(trait_ref) = self.ev.tcx.impl_trait_ref(self.item_def_id) {
986 self.visit_trait(trait_ref);
992 impl DefIdVisitor<'tcx> for ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
993 fn tcx(&self) -> TyCtxt<'tcx> {
996 fn visit_def_id(&mut self, def_id: DefId, _kind: &str, _descr: &dyn fmt::Display) -> bool {
997 if let Some(def_id) = def_id.as_local() {
998 let hir_id = self.ev.tcx.hir().as_local_hir_id(def_id);
999 if let ((ty::Visibility::Public, ..), _)
1000 | (_, Some(AccessLevel::ReachableFromImplTrait)) =
1001 (def_id_visibility(self.tcx(), def_id.to_def_id()), self.access_level)
1003 self.ev.update(hir_id, self.access_level);
1010 //////////////////////////////////////////////////////////////////////////////////////
1011 /// Name privacy visitor, checks privacy and reports violations.
1012 /// Most of name privacy checks are performed during the main resolution phase,
1013 /// or later in type checking when field accesses and associated items are resolved.
1014 /// This pass performs remaining checks for fields in struct expressions and patterns.
1015 //////////////////////////////////////////////////////////////////////////////////////
1017 struct NamePrivacyVisitor<'tcx> {
1019 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
1020 current_item: Option<hir::HirId>,
1023 impl<'tcx> NamePrivacyVisitor<'tcx> {
1024 /// Gets the type-checking results for the current body.
1025 /// As this will ICE if called outside bodies, only call when working with
1026 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
1028 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
1029 self.maybe_typeck_results
1030 .expect("`NamePrivacyVisitor::typeck_results` called outside of body")
1033 // Checks that a field in a struct constructor (expression or pattern) is accessible.
1036 use_ctxt: Span, // syntax context of the field name at the use site
1037 span: Span, // span of the field pattern, e.g., `x: 0`
1038 def: &'tcx ty::AdtDef, // definition of the struct or enum
1039 field: &'tcx ty::FieldDef,
1040 in_update_syntax: bool,
1042 // definition of the field
1043 let ident = Ident::new(kw::Invalid, use_ctxt);
1044 let current_hir = self.current_item.unwrap();
1045 let def_id = self.tcx.adjust_ident_and_get_scope(ident, def.did, current_hir).1;
1046 if !def.is_enum() && !field.vis.is_accessible_from(def_id, self.tcx) {
1047 let label = if in_update_syntax {
1048 format!("field `{}` is private", field.ident)
1050 "private field".to_string()
1057 "field `{}` of {} `{}` is private",
1059 def.variant_descr(),
1060 self.tcx.def_path_str(def.did)
1062 .span_label(span, label)
1068 impl<'tcx> Visitor<'tcx> for NamePrivacyVisitor<'tcx> {
1069 type Map = Map<'tcx>;
1071 /// We want to visit items in the context of their containing
1072 /// module and so forth, so supply a crate for doing a deep walk.
1073 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1074 NestedVisitorMap::All(self.tcx.hir())
1077 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
1078 // Don't visit nested modules, since we run a separate visitor walk
1079 // for each module in `privacy_access_levels`
1082 fn visit_nested_body(&mut self, body: hir::BodyId) {
1083 let old_maybe_typeck_results =
1084 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
1085 let body = self.tcx.hir().body(body);
1086 self.visit_body(body);
1087 self.maybe_typeck_results = old_maybe_typeck_results;
1090 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1091 let orig_current_item = self.current_item.replace(item.hir_id);
1092 intravisit::walk_item(self, item);
1093 self.current_item = orig_current_item;
1096 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
1097 if let hir::ExprKind::Struct(ref qpath, fields, ref base) = expr.kind {
1098 let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
1099 let adt = self.typeck_results().expr_ty(expr).ty_adt_def().unwrap();
1100 let variant = adt.variant_of_res(res);
1101 if let Some(ref base) = *base {
1102 // If the expression uses FRU we need to make sure all the unmentioned fields
1103 // are checked for privacy (RFC 736). Rather than computing the set of
1104 // unmentioned fields, just check them all.
1105 for (vf_index, variant_field) in variant.fields.iter().enumerate() {
1106 let field = fields.iter().find(|f| {
1107 self.tcx.field_index(f.hir_id, self.typeck_results()) == vf_index
1109 let (use_ctxt, span) = match field {
1110 Some(field) => (field.ident.span, field.span),
1111 None => (base.span, base.span),
1113 self.check_field(use_ctxt, span, adt, variant_field, true);
1116 for field in fields {
1117 let use_ctxt = field.ident.span;
1118 let index = self.tcx.field_index(field.hir_id, self.typeck_results());
1119 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1124 intravisit::walk_expr(self, expr);
1127 fn visit_pat(&mut self, pat: &'tcx hir::Pat<'tcx>) {
1128 if let PatKind::Struct(ref qpath, fields, _) = pat.kind {
1129 let res = self.typeck_results().qpath_res(qpath, pat.hir_id);
1130 let adt = self.typeck_results().pat_ty(pat).ty_adt_def().unwrap();
1131 let variant = adt.variant_of_res(res);
1132 for field in fields {
1133 let use_ctxt = field.ident.span;
1134 let index = self.tcx.field_index(field.hir_id, self.typeck_results());
1135 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1139 intravisit::walk_pat(self, pat);
1143 ////////////////////////////////////////////////////////////////////////////////////////////
1144 /// Type privacy visitor, checks types for privacy and reports violations.
1145 /// Both explicitly written types and inferred types of expressions and patters are checked.
1146 /// Checks are performed on "semantic" types regardless of names and their hygiene.
1147 ////////////////////////////////////////////////////////////////////////////////////////////
1149 struct TypePrivacyVisitor<'tcx> {
1151 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
1152 current_item: LocalDefId,
1156 impl<'tcx> TypePrivacyVisitor<'tcx> {
1157 /// Gets the type-checking results for the current body.
1158 /// As this will ICE if called outside bodies, only call when working with
1159 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
1161 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
1162 self.maybe_typeck_results
1163 .expect("`TypePrivacyVisitor::typeck_results` called outside of body")
1166 fn item_is_accessible(&self, did: DefId) -> bool {
1167 def_id_visibility(self.tcx, did)
1169 .is_accessible_from(self.current_item.to_def_id(), self.tcx)
1172 // Take node-id of an expression or pattern and check its type for privacy.
1173 fn check_expr_pat_type(&mut self, id: hir::HirId, span: Span) -> bool {
1175 let typeck_results = self.typeck_results();
1176 if self.visit(typeck_results.node_type(id)) || self.visit(typeck_results.node_substs(id)) {
1179 if let Some(adjustments) = typeck_results.adjustments().get(id) {
1180 for adjustment in adjustments {
1181 if self.visit(adjustment.target) {
1189 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1190 let is_error = !self.item_is_accessible(def_id);
1194 .struct_span_err(self.span, &format!("{} `{}` is private", kind, descr))
1195 .span_label(self.span, &format!("private {}", kind))
1202 impl<'tcx> Visitor<'tcx> for TypePrivacyVisitor<'tcx> {
1203 type Map = Map<'tcx>;
1205 /// We want to visit items in the context of their containing
1206 /// module and so forth, so supply a crate for doing a deep walk.
1207 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1208 NestedVisitorMap::All(self.tcx.hir())
1211 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
1212 // Don't visit nested modules, since we run a separate visitor walk
1213 // for each module in `privacy_access_levels`
1216 fn visit_nested_body(&mut self, body: hir::BodyId) {
1217 let old_maybe_typeck_results =
1218 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
1219 let body = self.tcx.hir().body(body);
1220 self.visit_body(body);
1221 self.maybe_typeck_results = old_maybe_typeck_results;
1224 fn visit_ty(&mut self, hir_ty: &'tcx hir::Ty<'tcx>) {
1225 self.span = hir_ty.span;
1226 if let Some(typeck_results) = self.maybe_typeck_results {
1228 if self.visit(typeck_results.node_type(hir_ty.hir_id)) {
1232 // Types in signatures.
1233 // FIXME: This is very ineffective. Ideally each HIR type should be converted
1234 // into a semantic type only once and the result should be cached somehow.
1235 if self.visit(rustc_typeck::hir_ty_to_ty(self.tcx, hir_ty)) {
1240 intravisit::walk_ty(self, hir_ty);
1243 fn visit_trait_ref(&mut self, trait_ref: &'tcx hir::TraitRef<'tcx>) {
1244 self.span = trait_ref.path.span;
1245 if self.maybe_typeck_results.is_none() {
1246 // Avoid calling `hir_trait_to_predicates` in bodies, it will ICE.
1247 // The traits' privacy in bodies is already checked as a part of trait object types.
1248 let bounds = rustc_typeck::hir_trait_to_predicates(
1251 // NOTE: This isn't really right, but the actual type doesn't matter here. It's
1252 // just required by `ty::TraitRef`.
1253 self.tcx.types.never,
1256 for (trait_predicate, _, _) in bounds.trait_bounds {
1257 if self.visit_trait(trait_predicate.skip_binder()) {
1262 for (poly_predicate, _) in bounds.projection_bounds {
1264 if self.visit(poly_predicate.skip_binder().ty)
1265 || self.visit_trait(poly_predicate.skip_binder().projection_ty.trait_ref(tcx))
1272 intravisit::walk_trait_ref(self, trait_ref);
1275 // Check types of expressions
1276 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
1277 if self.check_expr_pat_type(expr.hir_id, expr.span) {
1278 // Do not check nested expressions if the error already happened.
1282 hir::ExprKind::Assign(_, ref rhs, _) | hir::ExprKind::Match(ref rhs, ..) => {
1283 // Do not report duplicate errors for `x = y` and `match x { ... }`.
1284 if self.check_expr_pat_type(rhs.hir_id, rhs.span) {
1288 hir::ExprKind::MethodCall(_, span, _, _) => {
1289 // Method calls have to be checked specially.
1291 if let Some(def_id) = self.typeck_results().type_dependent_def_id(expr.hir_id) {
1292 if self.visit(self.tcx.type_of(def_id)) {
1298 .delay_span_bug(expr.span, "no type-dependent def for method call");
1304 intravisit::walk_expr(self, expr);
1307 // Prohibit access to associated items with insufficient nominal visibility.
1309 // Additionally, until better reachability analysis for macros 2.0 is available,
1310 // we prohibit access to private statics from other crates, this allows to give
1311 // more code internal visibility at link time. (Access to private functions
1312 // is already prohibited by type privacy for function types.)
1313 fn visit_qpath(&mut self, qpath: &'tcx hir::QPath<'tcx>, id: hir::HirId, span: Span) {
1314 let def = match qpath {
1315 hir::QPath::Resolved(_, path) => match path.res {
1316 Res::Def(kind, def_id) => Some((kind, def_id)),
1319 hir::QPath::TypeRelative(..) => self
1320 .maybe_typeck_results
1321 .and_then(|typeck_results| typeck_results.type_dependent_def(id)),
1323 let def = def.filter(|(kind, _)| match kind {
1324 DefKind::AssocFn | DefKind::AssocConst | DefKind::AssocTy | DefKind::Static => true,
1327 if let Some((kind, def_id)) = def {
1328 let is_local_static =
1329 if let DefKind::Static = kind { def_id.is_local() } else { false };
1330 if !self.item_is_accessible(def_id) && !is_local_static {
1331 let sess = self.tcx.sess;
1332 let sm = sess.source_map();
1333 let name = match qpath {
1334 hir::QPath::Resolved(_, path) => sm.span_to_snippet(path.span).ok(),
1335 hir::QPath::TypeRelative(_, segment) => Some(segment.ident.to_string()),
1337 let kind = kind.descr(def_id);
1338 let msg = match name {
1339 Some(name) => format!("{} `{}` is private", kind, name),
1340 None => format!("{} is private", kind),
1342 sess.struct_span_err(span, &msg)
1343 .span_label(span, &format!("private {}", kind))
1349 intravisit::walk_qpath(self, qpath, id, span);
1352 // Check types of patterns.
1353 fn visit_pat(&mut self, pattern: &'tcx hir::Pat<'tcx>) {
1354 if self.check_expr_pat_type(pattern.hir_id, pattern.span) {
1355 // Do not check nested patterns if the error already happened.
1359 intravisit::walk_pat(self, pattern);
1362 fn visit_local(&mut self, local: &'tcx hir::Local<'tcx>) {
1363 if let Some(ref init) = local.init {
1364 if self.check_expr_pat_type(init.hir_id, init.span) {
1365 // Do not report duplicate errors for `let x = y`.
1370 intravisit::walk_local(self, local);
1373 // Check types in item interfaces.
1374 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1375 let orig_current_item =
1376 mem::replace(&mut self.current_item, self.tcx.hir().local_def_id(item.hir_id));
1377 let old_maybe_typeck_results = self.maybe_typeck_results.take();
1378 intravisit::walk_item(self, item);
1379 self.maybe_typeck_results = old_maybe_typeck_results;
1380 self.current_item = orig_current_item;
1384 impl DefIdVisitor<'tcx> for TypePrivacyVisitor<'tcx> {
1385 fn tcx(&self) -> TyCtxt<'tcx> {
1388 fn visit_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1389 self.check_def_id(def_id, kind, descr)
1393 ///////////////////////////////////////////////////////////////////////////////
1394 /// Obsolete visitors for checking for private items in public interfaces.
1395 /// These visitors are supposed to be kept in frozen state and produce an
1396 /// "old error node set". For backward compatibility the new visitor reports
1397 /// warnings instead of hard errors when the erroneous node is not in this old set.
1398 ///////////////////////////////////////////////////////////////////////////////
1400 struct ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1402 access_levels: &'a AccessLevels,
1404 // Set of errors produced by this obsolete visitor.
1405 old_error_set: HirIdSet,
1408 struct ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1409 inner: &'a ObsoleteVisiblePrivateTypesVisitor<'b, 'tcx>,
1410 /// Whether the type refers to private types.
1411 contains_private: bool,
1412 /// Whether we've recurred at all (i.e., if we're pointing at the
1413 /// first type on which `visit_ty` was called).
1414 at_outer_type: bool,
1415 /// Whether that first type is a public path.
1416 outer_type_is_public_path: bool,
1419 impl<'a, 'tcx> ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1420 fn path_is_private_type(&self, path: &hir::Path<'_>) -> bool {
1421 let did = match path.res {
1422 Res::PrimTy(..) | Res::SelfTy(..) | Res::Err => return false,
1423 res => res.def_id(),
1426 // A path can only be private if:
1427 // it's in this crate...
1428 if let Some(did) = did.as_local() {
1429 // .. and it corresponds to a private type in the AST (this returns
1430 // `None` for type parameters).
1431 match self.tcx.hir().find(self.tcx.hir().as_local_hir_id(did)) {
1432 Some(Node::Item(ref item)) => !item.vis.node.is_pub(),
1433 Some(_) | None => false,
1440 fn trait_is_public(&self, trait_id: hir::HirId) -> bool {
1441 // FIXME: this would preferably be using `exported_items`, but all
1442 // traits are exported currently (see `EmbargoVisitor.exported_trait`).
1443 self.access_levels.is_public(trait_id)
1446 fn check_generic_bound(&mut self, bound: &hir::GenericBound<'_>) {
1447 if let hir::GenericBound::Trait(ref trait_ref, _) = *bound {
1448 if self.path_is_private_type(&trait_ref.trait_ref.path) {
1449 self.old_error_set.insert(trait_ref.trait_ref.hir_ref_id);
1454 fn item_is_public(&self, id: &hir::HirId, vis: &hir::Visibility<'_>) -> bool {
1455 self.access_levels.is_reachable(*id) || vis.node.is_pub()
1459 impl<'a, 'b, 'tcx, 'v> Visitor<'v> for ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1460 type Map = intravisit::ErasedMap<'v>;
1462 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1463 NestedVisitorMap::None
1466 fn visit_ty(&mut self, ty: &hir::Ty<'_>) {
1467 if let hir::TyKind::Path(hir::QPath::Resolved(_, ref path)) = ty.kind {
1468 if self.inner.path_is_private_type(path) {
1469 self.contains_private = true;
1470 // Found what we're looking for, so let's stop working.
1474 if let hir::TyKind::Path(_) = ty.kind {
1475 if self.at_outer_type {
1476 self.outer_type_is_public_path = true;
1479 self.at_outer_type = false;
1480 intravisit::walk_ty(self, ty)
1483 // Don't want to recurse into `[, .. expr]`.
1484 fn visit_expr(&mut self, _: &hir::Expr<'_>) {}
1487 impl<'a, 'tcx> Visitor<'tcx> for ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1488 type Map = Map<'tcx>;
1490 /// We want to visit items in the context of their containing
1491 /// module and so forth, so supply a crate for doing a deep walk.
1492 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1493 NestedVisitorMap::All(self.tcx.hir())
1496 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1498 // Contents of a private mod can be re-exported, so we need
1499 // to check internals.
1500 hir::ItemKind::Mod(_) => {}
1502 // An `extern {}` doesn't introduce a new privacy
1503 // namespace (the contents have their own privacies).
1504 hir::ItemKind::ForeignMod(_) => {}
1506 hir::ItemKind::Trait(.., ref bounds, _) => {
1507 if !self.trait_is_public(item.hir_id) {
1511 for bound in bounds.iter() {
1512 self.check_generic_bound(bound)
1516 // Impls need some special handling to try to offer useful
1517 // error messages without (too many) false positives
1518 // (i.e., we could just return here to not check them at
1519 // all, or some worse estimation of whether an impl is
1520 // publicly visible).
1521 hir::ItemKind::Impl { generics: ref g, ref of_trait, ref self_ty, items, .. } => {
1522 // `impl [... for] Private` is never visible.
1523 let self_contains_private;
1524 // `impl [... for] Public<...>`, but not `impl [... for]
1525 // Vec<Public>` or `(Public,)`, etc.
1526 let self_is_public_path;
1528 // Check the properties of the `Self` type:
1530 let mut visitor = ObsoleteCheckTypeForPrivatenessVisitor {
1532 contains_private: false,
1533 at_outer_type: true,
1534 outer_type_is_public_path: false,
1536 visitor.visit_ty(&self_ty);
1537 self_contains_private = visitor.contains_private;
1538 self_is_public_path = visitor.outer_type_is_public_path;
1541 // Miscellaneous info about the impl:
1543 // `true` iff this is `impl Private for ...`.
1544 let not_private_trait = of_trait.as_ref().map_or(
1545 true, // no trait counts as public trait
1547 let did = tr.path.res.def_id();
1549 if let Some(did) = did.as_local() {
1550 self.trait_is_public(self.tcx.hir().as_local_hir_id(did))
1552 true // external traits must be public
1557 // `true` iff this is a trait impl or at least one method is public.
1559 // `impl Public { $( fn ...() {} )* }` is not visible.
1561 // This is required over just using the methods' privacy
1562 // directly because we might have `impl<T: Foo<Private>> ...`,
1563 // and we shouldn't warn about the generics if all the methods
1564 // are private (because `T` won't be visible externally).
1565 let trait_or_some_public_method = of_trait.is_some()
1566 || items.iter().any(|impl_item_ref| {
1567 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1568 match impl_item.kind {
1569 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..) => {
1570 self.access_levels.is_reachable(impl_item_ref.id.hir_id)
1572 hir::ImplItemKind::TyAlias(_) => false,
1576 if !self_contains_private && not_private_trait && trait_or_some_public_method {
1577 intravisit::walk_generics(self, g);
1581 for impl_item_ref in items {
1582 // This is where we choose whether to walk down
1583 // further into the impl to check its items. We
1584 // should only walk into public items so that we
1585 // don't erroneously report errors for private
1586 // types in private items.
1587 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1588 match impl_item.kind {
1589 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..)
1591 .item_is_public(&impl_item.hir_id, &impl_item.vis) =>
1593 intravisit::walk_impl_item(self, impl_item)
1595 hir::ImplItemKind::TyAlias(..) => {
1596 intravisit::walk_impl_item(self, impl_item)
1603 // Any private types in a trait impl fall into three
1605 // 1. mentioned in the trait definition
1606 // 2. mentioned in the type params/generics
1607 // 3. mentioned in the associated types of the impl
1609 // Those in 1. can only occur if the trait is in
1610 // this crate and will've been warned about on the
1611 // trait definition (there's no need to warn twice
1612 // so we don't check the methods).
1614 // Those in 2. are warned via walk_generics and this
1616 intravisit::walk_path(self, &tr.path);
1618 // Those in 3. are warned with this call.
1619 for impl_item_ref in items {
1620 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1621 if let hir::ImplItemKind::TyAlias(ref ty) = impl_item.kind {
1627 } else if of_trait.is_none() && self_is_public_path {
1628 // `impl Public<Private> { ... }`. Any public static
1629 // methods will be visible as `Public::foo`.
1630 let mut found_pub_static = false;
1631 for impl_item_ref in items {
1632 if self.item_is_public(&impl_item_ref.id.hir_id, &impl_item_ref.vis) {
1633 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1634 match impl_item_ref.kind {
1635 AssocItemKind::Const => {
1636 found_pub_static = true;
1637 intravisit::walk_impl_item(self, impl_item);
1639 AssocItemKind::Fn { has_self: false } => {
1640 found_pub_static = true;
1641 intravisit::walk_impl_item(self, impl_item);
1647 if found_pub_static {
1648 intravisit::walk_generics(self, g)
1654 // `type ... = ...;` can contain private types, because
1655 // we're introducing a new name.
1656 hir::ItemKind::TyAlias(..) => return,
1658 // Not at all public, so we don't care.
1659 _ if !self.item_is_public(&item.hir_id, &item.vis) => {
1666 // We've carefully constructed it so that if we're here, then
1667 // any `visit_ty`'s will be called on things that are in
1668 // public signatures, i.e., things that we're interested in for
1670 intravisit::walk_item(self, item);
1673 fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
1674 for param in generics.params {
1675 for bound in param.bounds {
1676 self.check_generic_bound(bound);
1679 for predicate in generics.where_clause.predicates {
1681 hir::WherePredicate::BoundPredicate(bound_pred) => {
1682 for bound in bound_pred.bounds.iter() {
1683 self.check_generic_bound(bound)
1686 hir::WherePredicate::RegionPredicate(_) => {}
1687 hir::WherePredicate::EqPredicate(eq_pred) => {
1688 self.visit_ty(&eq_pred.rhs_ty);
1694 fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem<'tcx>) {
1695 if self.access_levels.is_reachable(item.hir_id) {
1696 intravisit::walk_foreign_item(self, item)
1700 fn visit_ty(&mut self, t: &'tcx hir::Ty<'tcx>) {
1701 if let hir::TyKind::Path(hir::QPath::Resolved(_, ref path)) = t.kind {
1702 if self.path_is_private_type(path) {
1703 self.old_error_set.insert(t.hir_id);
1706 intravisit::walk_ty(self, t)
1711 v: &'tcx hir::Variant<'tcx>,
1712 g: &'tcx hir::Generics<'tcx>,
1713 item_id: hir::HirId,
1715 if self.access_levels.is_reachable(v.id) {
1716 self.in_variant = true;
1717 intravisit::walk_variant(self, v, g, item_id);
1718 self.in_variant = false;
1722 fn visit_struct_field(&mut self, s: &'tcx hir::StructField<'tcx>) {
1723 if s.vis.node.is_pub() || self.in_variant {
1724 intravisit::walk_struct_field(self, s);
1728 // We don't need to introspect into these at all: an
1729 // expression/block context can't possibly contain exported things.
1730 // (Making them no-ops stops us from traversing the whole AST without
1731 // having to be super careful about our `walk_...` calls above.)
1732 fn visit_block(&mut self, _: &'tcx hir::Block<'tcx>) {}
1733 fn visit_expr(&mut self, _: &'tcx hir::Expr<'tcx>) {}
1736 ///////////////////////////////////////////////////////////////////////////////
1737 /// SearchInterfaceForPrivateItemsVisitor traverses an item's interface and
1738 /// finds any private components in it.
1739 /// PrivateItemsInPublicInterfacesVisitor ensures there are no private types
1740 /// and traits in public interfaces.
1741 ///////////////////////////////////////////////////////////////////////////////
1743 struct SearchInterfaceForPrivateItemsVisitor<'tcx> {
1745 item_id: hir::HirId,
1748 /// The visitor checks that each component type is at least this visible.
1749 required_visibility: ty::Visibility,
1750 has_pub_restricted: bool,
1751 has_old_errors: bool,
1755 impl SearchInterfaceForPrivateItemsVisitor<'tcx> {
1756 fn generics(&mut self) -> &mut Self {
1757 for param in &self.tcx.generics_of(self.item_def_id).params {
1759 GenericParamDefKind::Lifetime => {}
1760 GenericParamDefKind::Type { has_default, .. } => {
1762 self.visit(self.tcx.type_of(param.def_id));
1765 GenericParamDefKind::Const => {
1766 self.visit(self.tcx.type_of(param.def_id));
1773 fn predicates(&mut self) -> &mut Self {
1774 // N.B., we use `explicit_predicates_of` and not `predicates_of`
1775 // because we don't want to report privacy errors due to where
1776 // clauses that the compiler inferred. We only want to
1777 // consider the ones that the user wrote. This is important
1778 // for the inferred outlives rules; see
1779 // `src/test/ui/rfc-2093-infer-outlives/privacy.rs`.
1780 self.visit_predicates(self.tcx.explicit_predicates_of(self.item_def_id));
1784 fn ty(&mut self) -> &mut Self {
1785 self.visit(self.tcx.type_of(self.item_def_id));
1789 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1790 if self.leaks_private_dep(def_id) {
1791 self.tcx.struct_span_lint_hir(
1792 lint::builtin::EXPORTED_PRIVATE_DEPENDENCIES,
1796 lint.build(&format!(
1797 "{} `{}` from private dependency '{}' in public \
1801 self.tcx.crate_name(def_id.krate)
1808 let hir_id = match def_id.as_local() {
1809 Some(def_id) => self.tcx.hir().as_local_hir_id(def_id),
1810 None => return false,
1813 let (vis, vis_span, vis_descr) = def_id_visibility(self.tcx, def_id);
1814 if !vis.is_at_least(self.required_visibility, self.tcx) {
1815 let make_msg = || format!("{} {} `{}` in public interface", vis_descr, kind, descr);
1816 if self.has_pub_restricted || self.has_old_errors || self.in_assoc_ty {
1817 let mut err = if kind == "trait" {
1818 struct_span_err!(self.tcx.sess, self.span, E0445, "{}", make_msg())
1820 struct_span_err!(self.tcx.sess, self.span, E0446, "{}", make_msg())
1822 err.span_label(self.span, format!("can't leak {} {}", vis_descr, kind));
1823 err.span_label(vis_span, format!("`{}` declared as {}", descr, vis_descr));
1826 let err_code = if kind == "trait" { "E0445" } else { "E0446" };
1827 self.tcx.struct_span_lint_hir(
1828 lint::builtin::PRIVATE_IN_PUBLIC,
1831 |lint| lint.build(&format!("{} (error {})", make_msg(), err_code)).emit(),
1839 /// An item is 'leaked' from a private dependency if all
1840 /// of the following are true:
1841 /// 1. It's contained within a public type
1842 /// 2. It comes from a private crate
1843 fn leaks_private_dep(&self, item_id: DefId) -> bool {
1844 let ret = self.required_visibility == ty::Visibility::Public
1845 && self.tcx.is_private_dep(item_id.krate);
1847 log::debug!("leaks_private_dep(item_id={:?})={}", item_id, ret);
1852 impl DefIdVisitor<'tcx> for SearchInterfaceForPrivateItemsVisitor<'tcx> {
1853 fn tcx(&self) -> TyCtxt<'tcx> {
1856 fn visit_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1857 self.check_def_id(def_id, kind, descr)
1861 struct PrivateItemsInPublicInterfacesVisitor<'a, 'tcx> {
1863 has_pub_restricted: bool,
1864 old_error_set: &'a HirIdSet,
1867 impl<'a, 'tcx> PrivateItemsInPublicInterfacesVisitor<'a, 'tcx> {
1870 item_id: hir::HirId,
1871 required_visibility: ty::Visibility,
1872 ) -> SearchInterfaceForPrivateItemsVisitor<'tcx> {
1873 let mut has_old_errors = false;
1875 // Slow path taken only if there any errors in the crate.
1876 for &id in self.old_error_set {
1877 // Walk up the nodes until we find `item_id` (or we hit a root).
1881 has_old_errors = true;
1884 let parent = self.tcx.hir().get_parent_node(id);
1896 SearchInterfaceForPrivateItemsVisitor {
1899 item_def_id: self.tcx.hir().local_def_id(item_id).to_def_id(),
1900 span: self.tcx.hir().span(item_id),
1901 required_visibility,
1902 has_pub_restricted: self.has_pub_restricted,
1908 fn check_assoc_item(
1911 assoc_item_kind: AssocItemKind,
1912 defaultness: hir::Defaultness,
1913 vis: ty::Visibility,
1915 let mut check = self.check(hir_id, vis);
1917 let (check_ty, is_assoc_ty) = match assoc_item_kind {
1918 AssocItemKind::Const | AssocItemKind::Fn { .. } => (true, false),
1919 AssocItemKind::Type => (defaultness.has_value(), true),
1921 check.in_assoc_ty = is_assoc_ty;
1922 check.generics().predicates();
1929 impl<'a, 'tcx> Visitor<'tcx> for PrivateItemsInPublicInterfacesVisitor<'a, 'tcx> {
1930 type Map = Map<'tcx>;
1932 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1933 NestedVisitorMap::OnlyBodies(self.tcx.hir())
1936 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1938 let item_visibility = ty::Visibility::from_hir(&item.vis, item.hir_id, tcx);
1941 // Crates are always public.
1942 hir::ItemKind::ExternCrate(..) => {}
1943 // All nested items are checked by `visit_item`.
1944 hir::ItemKind::Mod(..) => {}
1945 // Checked in resolve.
1946 hir::ItemKind::Use(..) => {}
1948 hir::ItemKind::GlobalAsm(..) => {}
1949 // Subitems of these items have inherited publicity.
1950 hir::ItemKind::Const(..)
1951 | hir::ItemKind::Static(..)
1952 | hir::ItemKind::Fn(..)
1953 | hir::ItemKind::TyAlias(..) => {
1954 self.check(item.hir_id, item_visibility).generics().predicates().ty();
1956 hir::ItemKind::OpaqueTy(..) => {
1957 // `ty()` for opaque types is the underlying type,
1958 // it's not a part of interface, so we skip it.
1959 self.check(item.hir_id, item_visibility).generics().predicates();
1961 hir::ItemKind::Trait(.., trait_item_refs) => {
1962 self.check(item.hir_id, item_visibility).generics().predicates();
1964 for trait_item_ref in trait_item_refs {
1965 self.check_assoc_item(
1966 trait_item_ref.id.hir_id,
1967 trait_item_ref.kind,
1968 trait_item_ref.defaultness,
1973 hir::ItemKind::TraitAlias(..) => {
1974 self.check(item.hir_id, item_visibility).generics().predicates();
1976 hir::ItemKind::Enum(ref def, _) => {
1977 self.check(item.hir_id, item_visibility).generics().predicates();
1979 for variant in def.variants {
1980 for field in variant.data.fields() {
1981 self.check(field.hir_id, item_visibility).ty();
1985 // Subitems of foreign modules have their own publicity.
1986 hir::ItemKind::ForeignMod(ref foreign_mod) => {
1987 for foreign_item in foreign_mod.items {
1988 let vis = ty::Visibility::from_hir(&foreign_item.vis, item.hir_id, tcx);
1989 self.check(foreign_item.hir_id, vis).generics().predicates().ty();
1992 // Subitems of structs and unions have their own publicity.
1993 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
1994 self.check(item.hir_id, item_visibility).generics().predicates();
1996 for field in struct_def.fields() {
1997 let field_visibility = ty::Visibility::from_hir(&field.vis, item.hir_id, tcx);
1998 self.check(field.hir_id, min(item_visibility, field_visibility, tcx)).ty();
2001 // An inherent impl is public when its type is public
2002 // Subitems of inherent impls have their own publicity.
2003 // A trait impl is public when both its type and its trait are public
2004 // Subitems of trait impls have inherited publicity.
2005 hir::ItemKind::Impl { ref of_trait, items, .. } => {
2006 let impl_vis = ty::Visibility::of_impl(item.hir_id, tcx, &Default::default());
2007 self.check(item.hir_id, impl_vis).generics().predicates();
2008 for impl_item_ref in items {
2009 let impl_item = tcx.hir().impl_item(impl_item_ref.id);
2010 let impl_item_vis = if of_trait.is_none() {
2012 ty::Visibility::from_hir(&impl_item.vis, item.hir_id, tcx),
2019 self.check_assoc_item(
2020 impl_item_ref.id.hir_id,
2022 impl_item_ref.defaultness,
2031 pub fn provide(providers: &mut Providers) {
2032 *providers = Providers {
2033 privacy_access_levels,
2034 check_private_in_public,
2040 fn check_mod_privacy(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
2041 // Check privacy of names not checked in previous compilation stages.
2042 let mut visitor = NamePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: None };
2043 let (module, span, hir_id) = tcx.hir().get_module(module_def_id);
2045 intravisit::walk_mod(&mut visitor, module, hir_id);
2047 // Check privacy of explicitly written types and traits as well as
2048 // inferred types of expressions and patterns.
2050 TypePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id, span };
2051 intravisit::walk_mod(&mut visitor, module, hir_id);
2054 fn privacy_access_levels(tcx: TyCtxt<'_>, krate: CrateNum) -> &AccessLevels {
2055 assert_eq!(krate, LOCAL_CRATE);
2057 // Build up a set of all exported items in the AST. This is a set of all
2058 // items which are reachable from external crates based on visibility.
2059 let mut visitor = EmbargoVisitor {
2061 access_levels: Default::default(),
2062 macro_reachable: Default::default(),
2063 prev_level: Some(AccessLevel::Public),
2067 intravisit::walk_crate(&mut visitor, tcx.hir().krate());
2068 if visitor.changed {
2069 visitor.changed = false;
2074 visitor.update(hir::CRATE_HIR_ID, Some(AccessLevel::Public));
2076 tcx.arena.alloc(visitor.access_levels)
2079 fn check_private_in_public(tcx: TyCtxt<'_>, krate: CrateNum) {
2080 assert_eq!(krate, LOCAL_CRATE);
2082 let access_levels = tcx.privacy_access_levels(LOCAL_CRATE);
2084 let krate = tcx.hir().krate();
2086 let mut visitor = ObsoleteVisiblePrivateTypesVisitor {
2088 access_levels: &access_levels,
2090 old_error_set: Default::default(),
2092 intravisit::walk_crate(&mut visitor, krate);
2094 let has_pub_restricted = {
2095 let mut pub_restricted_visitor = PubRestrictedVisitor { tcx, has_pub_restricted: false };
2096 intravisit::walk_crate(&mut pub_restricted_visitor, krate);
2097 pub_restricted_visitor.has_pub_restricted
2100 // Check for private types and traits in public interfaces.
2101 let mut visitor = PrivateItemsInPublicInterfacesVisitor {
2104 old_error_set: &visitor.old_error_set,
2106 krate.visit_all_item_likes(&mut DeepVisitor::new(&mut visitor));