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#![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
#![deny(rust_2018_idioms)]
#![deny(unused_lifetimes)]
#![feature(in_band_lifetimes)]
#![feature(nll)]
#![feature(rustc_diagnostic_macros)]
#![recursion_limit="256"]
#[macro_use] extern crate syntax;
use rustc::bug;
use rustc::hir::{self, Node, PatKind, AssocItemKind};
use rustc::hir::def::{Res, DefKind};
use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, CrateNum, DefId};
use rustc::hir::intravisit::{self, Visitor, NestedVisitorMap};
use rustc::hir::itemlikevisit::DeepVisitor;
use rustc::lint;
use rustc::middle::privacy::{AccessLevel, AccessLevels};
use rustc::ty::{self, TyCtxt, Ty, TraitRef, TypeFoldable, GenericParamDefKind};
use rustc::ty::fold::TypeVisitor;
use rustc::ty::query::Providers;
use rustc::ty::subst::InternalSubsts;
use rustc::util::nodemap::HirIdSet;
use rustc_data_structures::fx::FxHashSet;
use syntax::ast::Ident;
use syntax::attr;
use syntax::symbol::{kw, sym};
use syntax_pos::hygiene::Transparency;
use syntax_pos::Span;
use std::{cmp, fmt, mem};
use std::marker::PhantomData;
mod error_codes;
////////////////////////////////////////////////////////////////////////////////
/// Generic infrastructure used to implement specific visitors below.
////////////////////////////////////////////////////////////////////////////////
/// Implemented to visit all `DefId`s in a type.
/// Visiting `DefId`s is useful because visibilities and reachabilities are attached to them.
/// The idea is to visit "all components of a type", as documented in
/// https://github.com/rust-lang/rfcs/blob/master/text/2145-type-privacy.md#how-to-determine-visibility-of-a-type.
/// The default type visitor (`TypeVisitor`) does most of the job, but it has some shortcomings.
/// First, it doesn't have overridable `fn visit_trait_ref`, so we have to catch trait `DefId`s
/// manually. Second, it doesn't visit some type components like signatures of fn types, or traits
/// in `impl Trait`, see individual comments in `DefIdVisitorSkeleton::visit_ty`.
trait DefIdVisitor<'tcx> {
fn tcx(&self) -> TyCtxt<'tcx>;
fn shallow(&self) -> bool { false }
fn skip_assoc_tys(&self) -> bool { false }
fn visit_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool;
/// Not overridden, but used to actually visit types and traits.
fn skeleton(&mut self) -> DefIdVisitorSkeleton<'_, 'tcx, Self> {
DefIdVisitorSkeleton {
def_id_visitor: self,
visited_opaque_tys: Default::default(),
dummy: Default::default(),
}
}
fn visit(&mut self, ty_fragment: impl TypeFoldable<'tcx>) -> bool {
ty_fragment.visit_with(&mut self.skeleton())
}
fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> bool {
self.skeleton().visit_trait(trait_ref)
}
fn visit_predicates(&mut self, predicates: &ty::GenericPredicates<'tcx>) -> bool {
self.skeleton().visit_predicates(predicates)
}
}
struct DefIdVisitorSkeleton<'v, 'tcx, V>
where
V: DefIdVisitor<'tcx> + ?Sized,
{
def_id_visitor: &'v mut V,
visited_opaque_tys: FxHashSet<DefId>,
dummy: PhantomData<TyCtxt<'tcx>>,
}
impl<'tcx, V> DefIdVisitorSkeleton<'_, 'tcx, V>
where
V: DefIdVisitor<'tcx> + ?Sized,
{
fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> bool {
let TraitRef { def_id, substs } = trait_ref;
self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref) ||
(!self.def_id_visitor.shallow() && substs.visit_with(self))
}
fn visit_predicates(&mut self, predicates: &ty::GenericPredicates<'tcx>) -> bool {
let ty::GenericPredicates { parent: _, predicates } = predicates;
for (predicate, _span) in predicates {
match predicate {
ty::Predicate::Trait(poly_predicate) => {
let ty::TraitPredicate { trait_ref } = *poly_predicate.skip_binder();
if self.visit_trait(trait_ref) {
return true;
}
}
ty::Predicate::Projection(poly_predicate) => {
let ty::ProjectionPredicate { projection_ty, ty } =
*poly_predicate.skip_binder();
if ty.visit_with(self) {
return true;
}
if self.visit_trait(projection_ty.trait_ref(self.def_id_visitor.tcx())) {
return true;
}
}
ty::Predicate::TypeOutlives(poly_predicate) => {
let ty::OutlivesPredicate(ty, _region) = *poly_predicate.skip_binder();
if ty.visit_with(self) {
return true;
}
}
ty::Predicate::RegionOutlives(..) => {},
_ => bug!("unexpected predicate: {:?}", predicate),
}
}
false
}
}
impl<'tcx, V> TypeVisitor<'tcx> for DefIdVisitorSkeleton<'_, 'tcx, V>
where
V: DefIdVisitor<'tcx> + ?Sized,
{
fn visit_ty(&mut self, ty: Ty<'tcx>) -> bool {
let tcx = self.def_id_visitor.tcx();
// InternalSubsts are not visited here because they are visited below in `super_visit_with`.
match ty.sty {
ty::Adt(&ty::AdtDef { did: def_id, .. }, ..) |
ty::Foreign(def_id) |
ty::FnDef(def_id, ..) |
ty::Closure(def_id, ..) |
ty::Generator(def_id, ..) => {
if self.def_id_visitor.visit_def_id(def_id, "type", &ty) {
return true;
}
if self.def_id_visitor.shallow() {
return false;
}
// Default type visitor doesn't visit signatures of fn types.
// Something like `fn() -> Priv {my_func}` is considered a private type even if
// `my_func` is public, so we need to visit signatures.
if let ty::FnDef(..) = ty.sty {
if tcx.fn_sig(def_id).visit_with(self) {
return true;
}
}
// Inherent static methods don't have self type in substs.
// Something like `fn() {my_method}` type of the method
// `impl Pub<Priv> { pub fn my_method() {} }` is considered a private type,
// so we need to visit the self type additionally.
if let Some(assoc_item) = tcx.opt_associated_item(def_id) {
if let ty::ImplContainer(impl_def_id) = assoc_item.container {
if tcx.type_of(impl_def_id).visit_with(self) {
return true;
}
}
}
}
ty::Projection(proj) | ty::UnnormalizedProjection(proj) => {
if self.def_id_visitor.skip_assoc_tys() {
// Visitors searching for minimal visibility/reachability want to
// conservatively approximate associated types like `<Type as Trait>::Alias`
// as visible/reachable even if both `Type` and `Trait` are private.
// Ideally, associated types should be substituted in the same way as
// free type aliases, but this isn't done yet.
return false;
}
// This will also visit substs if necessary, so we don't need to recurse.
return self.visit_trait(proj.trait_ref(tcx));
}
ty::Dynamic(predicates, ..) => {
// All traits in the list are considered the "primary" part of the type
// and are visited by shallow visitors.
for predicate in *predicates.skip_binder() {
let trait_ref = match *predicate {
ty::ExistentialPredicate::Trait(trait_ref) => trait_ref,
ty::ExistentialPredicate::Projection(proj) => proj.trait_ref(tcx),
ty::ExistentialPredicate::AutoTrait(def_id) =>
ty::ExistentialTraitRef { def_id, substs: InternalSubsts::empty() },
};
let ty::ExistentialTraitRef { def_id, substs: _ } = trait_ref;
if self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref) {
return true;
}
}
}
ty::Opaque(def_id, ..) => {
// Skip repeated `Opaque`s to avoid infinite recursion.
if self.visited_opaque_tys.insert(def_id) {
// The intent is to treat `impl Trait1 + Trait2` identically to
// `dyn Trait1 + Trait2`. Therefore we ignore def-id of the opaque type itself
// (it either has no visibility, or its visibility is insignificant, like
// visibilities of type aliases) and recurse into predicates instead to go
// through the trait list (default type visitor doesn't visit those traits).
// All traits in the list are considered the "primary" part of the type
// and are visited by shallow visitors.
if self.visit_predicates(tcx.predicates_of(def_id)) {
return true;
}
}
}
// These types don't have their own def-ids (but may have subcomponents
// with def-ids that should be visited recursively).
ty::Bool | ty::Char | ty::Int(..) | ty::Uint(..) |
ty::Float(..) | ty::Str | ty::Never |
ty::Array(..) | ty::Slice(..) | ty::Tuple(..) |
ty::RawPtr(..) | ty::Ref(..) | ty::FnPtr(..) |
ty::Param(..) | ty::Error | ty::GeneratorWitness(..) => {}
ty::Bound(..) | ty::Placeholder(..) | ty::Infer(..) =>
bug!("unexpected type: {:?}", ty),
}
!self.def_id_visitor.shallow() && ty.super_visit_with(self)
}
}
fn def_id_visibility<'tcx>(
tcx: TyCtxt<'tcx>,
def_id: DefId,
) -> (ty::Visibility, Span, &'static str) {
match tcx.hir().as_local_hir_id(def_id) {
Some(hir_id) => {
let vis = match tcx.hir().get(hir_id) {
Node::Item(item) => &item.vis,
Node::ForeignItem(foreign_item) => &foreign_item.vis,
Node::TraitItem(..) | Node::Variant(..) => {
return def_id_visibility(tcx, tcx.hir().get_parent_did(hir_id));
}
Node::ImplItem(impl_item) => {
match tcx.hir().get(tcx.hir().get_parent_item(hir_id)) {
Node::Item(item) => match &item.node {
hir::ItemKind::Impl(.., None, _, _) => &impl_item.vis,
hir::ItemKind::Impl(.., Some(trait_ref), _, _)
=> return def_id_visibility(tcx, trait_ref.path.res.def_id()),
kind => bug!("unexpected item kind: {:?}", kind),
}
node => bug!("unexpected node kind: {:?}", node),
}
}
Node::Ctor(vdata) => {
let parent_hir_id = tcx.hir().get_parent_node(hir_id);
match tcx.hir().get(parent_hir_id) {
Node::Variant(..) => {
let parent_did = tcx.hir().local_def_id(parent_hir_id);
let (mut ctor_vis, mut span, mut descr) = def_id_visibility(
tcx, parent_did,
);
let adt_def = tcx.adt_def(tcx.hir().get_parent_did(hir_id));
let ctor_did = tcx.hir().local_def_id(
vdata.ctor_hir_id().unwrap());
let variant = adt_def.variant_with_ctor_id(ctor_did);
if variant.is_field_list_non_exhaustive() &&
ctor_vis == ty::Visibility::Public
{
ctor_vis = ty::Visibility::Restricted(
DefId::local(CRATE_DEF_INDEX));
let attrs = tcx.get_attrs(variant.def_id);
span = attr::find_by_name(&attrs, sym::non_exhaustive)
.unwrap().span;
descr = "crate-visible";
}
return (ctor_vis, span, descr);
}
Node::Item(..) => {
let item = match tcx.hir().get(parent_hir_id) {
Node::Item(item) => item,
node => bug!("unexpected node kind: {:?}", node),
};
let (mut ctor_vis, mut span, mut descr) =
(ty::Visibility::from_hir(&item.vis, parent_hir_id, tcx),
item.vis.span, item.vis.node.descr());
for field in vdata.fields() {
let field_vis = ty::Visibility::from_hir(&field.vis, hir_id, tcx);
if ctor_vis.is_at_least(field_vis, tcx) {
ctor_vis = field_vis;
span = field.vis.span;
descr = field.vis.node.descr();
}
}
// If the structure is marked as non_exhaustive then lower the
// visibility to within the crate.
if ctor_vis == ty::Visibility::Public {
let adt_def =
tcx.adt_def(tcx.hir().get_parent_did(hir_id));
if adt_def.non_enum_variant().is_field_list_non_exhaustive() {
ctor_vis =
ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
span = attr::find_by_name(&item.attrs, sym::non_exhaustive)
.unwrap().span;
descr = "crate-visible";
}
}
return (ctor_vis, span, descr);
}
node => bug!("unexpected node kind: {:?}", node),
}
}
Node::Expr(expr) => {
return (ty::Visibility::Restricted(
tcx.hir().get_module_parent(expr.hir_id)),
expr.span, "private")
}
node => bug!("unexpected node kind: {:?}", node)
};
(ty::Visibility::from_hir(vis, hir_id, tcx), vis.span, vis.node.descr())
}
None => {
let vis = tcx.visibility(def_id);
let descr = if vis == ty::Visibility::Public { "public" } else { "private" };
(vis, tcx.def_span(def_id), descr)
}
}
}
// Set the correct `TypeckTables` for the given `item_id` (or an empty table if
// there is no `TypeckTables` for the item).
fn item_tables<'a, 'tcx>(
tcx: TyCtxt<'tcx>,
hir_id: hir::HirId,
empty_tables: &'a ty::TypeckTables<'tcx>,
) -> &'a ty::TypeckTables<'tcx> {
let def_id = tcx.hir().local_def_id(hir_id);
if tcx.has_typeck_tables(def_id) { tcx.typeck_tables_of(def_id) } else { empty_tables }
}
fn min(vis1: ty::Visibility, vis2: ty::Visibility, tcx: TyCtxt<'_>) -> ty::Visibility {
if vis1.is_at_least(vis2, tcx) { vis2 } else { vis1 }
}
////////////////////////////////////////////////////////////////////////////////
/// Visitor used to determine if pub(restricted) is used anywhere in the crate.
///
/// This is done so that `private_in_public` warnings can be turned into hard errors
/// in crates that have been updated to use pub(restricted).
////////////////////////////////////////////////////////////////////////////////
struct PubRestrictedVisitor<'tcx> {
tcx: TyCtxt<'tcx>,
has_pub_restricted: bool,
}
impl Visitor<'tcx> for PubRestrictedVisitor<'tcx> {
fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
NestedVisitorMap::All(&self.tcx.hir())
}
fn visit_vis(&mut self, vis: &'tcx hir::Visibility) {
self.has_pub_restricted = self.has_pub_restricted || vis.node.is_pub_restricted();
}
}
////////////////////////////////////////////////////////////////////////////////
/// Visitor used to determine impl visibility and reachability.
////////////////////////////////////////////////////////////////////////////////
struct FindMin<'a, 'tcx, VL: VisibilityLike> {
tcx: TyCtxt<'tcx>,
access_levels: &'a AccessLevels,
min: VL,
}
impl<'a, 'tcx, VL: VisibilityLike> DefIdVisitor<'tcx> for FindMin<'a, 'tcx, VL> {
fn tcx(&self) -> TyCtxt<'tcx> { self.tcx }
fn shallow(&self) -> bool { VL::SHALLOW }
fn skip_assoc_tys(&self) -> bool { true }
fn visit_def_id(&mut self, def_id: DefId, _kind: &str, _descr: &dyn fmt::Display) -> bool {
self.min = VL::new_min(self, def_id);
false
}
}
trait VisibilityLike: Sized {
const MAX: Self;
const SHALLOW: bool = false;
fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self;
// Returns an over-approximation (`skip_assoc_tys` = true) of visibility due to
// associated types for which we can't determine visibility precisely.
fn of_impl(
hir_id: hir::HirId,
tcx: TyCtxt<'_>,
access_levels: &AccessLevels,
) -> Self {
let mut find = FindMin { tcx, access_levels, min: Self::MAX };
let def_id = tcx.hir().local_def_id(hir_id);
find.visit(tcx.type_of(def_id));
if let Some(trait_ref) = tcx.impl_trait_ref(def_id) {
find.visit_trait(trait_ref);
}
find.min
}
}
impl VisibilityLike for ty::Visibility {
const MAX: Self = ty::Visibility::Public;
fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
min(def_id_visibility(find.tcx, def_id).0, find.min, find.tcx)
}
}
impl VisibilityLike for Option<AccessLevel> {
const MAX: Self = Some(AccessLevel::Public);
// Type inference is very smart sometimes.
// It can make an impl reachable even some components of its type or trait are unreachable.
// E.g. methods of `impl ReachableTrait<UnreachableTy> for ReachableTy<UnreachableTy> { ... }`
// can be usable from other crates (#57264). So we skip substs when calculating reachability
// and consider an impl reachable if its "shallow" type and trait are reachable.
//
// The assumption we make here is that type-inference won't let you use an impl without knowing
// both "shallow" version of its self type and "shallow" version of its trait if it exists
// (which require reaching the `DefId`s in them).
const SHALLOW: bool = true;
fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
cmp::min(if let Some(hir_id) = find.tcx.hir().as_local_hir_id(def_id) {
find.access_levels.map.get(&hir_id).cloned()
} else {
Self::MAX
}, find.min)
}
}
////////////////////////////////////////////////////////////////////////////////
/// The embargo visitor, used to determine the exports of the AST.
////////////////////////////////////////////////////////////////////////////////
struct EmbargoVisitor<'tcx> {
tcx: TyCtxt<'tcx>,
// Accessibility levels for reachable nodes.
access_levels: AccessLevels,
// Previous accessibility level; `None` means unreachable.
prev_level: Option<AccessLevel>,
// Has something changed in the level map?
changed: bool,
}
struct ReachEverythingInTheInterfaceVisitor<'a, 'tcx> {
access_level: Option<AccessLevel>,
item_def_id: DefId,
ev: &'a mut EmbargoVisitor<'tcx>,
}
impl EmbargoVisitor<'tcx> {
fn get(&self, id: hir::HirId) -> Option<AccessLevel> {
self.access_levels.map.get(&id).cloned()
}
// Updates node level and returns the updated level.
fn update(&mut self, id: hir::HirId, level: Option<AccessLevel>) -> Option<AccessLevel> {
let old_level = self.get(id);
// Accessibility levels can only grow.
if level > old_level {
self.access_levels.map.insert(id, level.unwrap());
self.changed = true;
level
} else {
old_level
}
}
fn reach(
&mut self,
item_id: hir::HirId,
access_level: Option<AccessLevel>,
) -> ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
ReachEverythingInTheInterfaceVisitor {
access_level: cmp::min(access_level, Some(AccessLevel::Reachable)),
item_def_id: self.tcx.hir().local_def_id(item_id),
ev: self,
}
}
/// Given the path segments of a `ItemKind::Use`, then we need
/// to update the visibility of the intermediate use so that it isn't linted
/// by `unreachable_pub`.
///
/// This isn't trivial as `path.res` has the `DefId` of the eventual target
/// of the use statement not of the next intermediate use statement.
///
/// To do this, consider the last two segments of the path to our intermediate
/// use statement. We expect the penultimate segment to be a module and the
/// last segment to be the name of the item we are exporting. We can then
/// look at the items contained in the module for the use statement with that
/// name and update that item's visibility.
///
/// FIXME: This solution won't work with glob imports and doesn't respect
/// namespaces. See <https://github.com/rust-lang/rust/pull/57922#discussion_r251234202>.
fn update_visibility_of_intermediate_use_statements(&mut self, segments: &[hir::PathSegment]) {
if let Some([module, segment]) = segments.rchunks_exact(2).next() {
if let Some(item) = module.res
.and_then(|res| res.mod_def_id())
.and_then(|def_id| self.tcx.hir().as_local_hir_id(def_id))
.map(|module_hir_id| self.tcx.hir().expect_item(module_hir_id))
{
if let hir::ItemKind::Mod(m) = &item.node {
for item_id in m.item_ids.as_ref() {
let item = self.tcx.hir().expect_item(item_id.id);
let def_id = self.tcx.hir().local_def_id(item_id.id);
if !self.tcx.hygienic_eq(segment.ident, item.ident, def_id) { continue; }
if let hir::ItemKind::Use(..) = item.node {
self.update(item.hir_id, Some(AccessLevel::Exported));
}
}
}
}
}
}
}
impl Visitor<'tcx> for EmbargoVisitor<'tcx> {
/// We want to visit items in the context of their containing
/// module and so forth, so supply a crate for doing a deep walk.
fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
NestedVisitorMap::All(&self.tcx.hir())
}
fn visit_item(&mut self, item: &'tcx hir::Item) {
let inherited_item_level = match item.node {
hir::ItemKind::Impl(..) =>
Option::<AccessLevel>::of_impl(item.hir_id, self.tcx, &self.access_levels),
// Foreign modules inherit level from parents.
hir::ItemKind::ForeignMod(..) => self.prev_level,
// Other `pub` items inherit levels from parents.
hir::ItemKind::Const(..) | hir::ItemKind::Enum(..) | hir::ItemKind::ExternCrate(..) |
hir::ItemKind::GlobalAsm(..) | hir::ItemKind::Fn(..) | hir::ItemKind::Mod(..) |
hir::ItemKind::Static(..) | hir::ItemKind::Struct(..) |
hir::ItemKind::Trait(..) | hir::ItemKind::TraitAlias(..) |
hir::ItemKind::Existential(..) |
hir::ItemKind::Ty(..) | hir::ItemKind::Union(..) | hir::ItemKind::Use(..) => {
if item.vis.node.is_pub() { self.prev_level } else { None }
}
};
// Update level of the item itself.
let item_level = self.update(item.hir_id, inherited_item_level);
// Update levels of nested things.
match item.node {
hir::ItemKind::Enum(ref def, _) => {
for variant in &def.variants {
let variant_level = self.update(variant.node.id, item_level);
if let Some(ctor_hir_id) = variant.node.data.ctor_hir_id() {
self.update(ctor_hir_id, item_level);
}
for field in variant.node.data.fields() {
self.update(field.hir_id, variant_level);
}
}
}
hir::ItemKind::Impl(.., ref trait_ref, _, ref impl_item_refs) => {
for impl_item_ref in impl_item_refs {
if trait_ref.is_some() || impl_item_ref.vis.node.is_pub() {
self.update(impl_item_ref.id.hir_id, item_level);
}
}
}
hir::ItemKind::Trait(.., ref trait_item_refs) => {
for trait_item_ref in trait_item_refs {
self.update(trait_item_ref.id.hir_id, item_level);
}
}
hir::ItemKind::Struct(ref def, _) | hir::ItemKind::Union(ref def, _) => {
if let Some(ctor_hir_id) = def.ctor_hir_id() {
self.update(ctor_hir_id, item_level);
}
for field in def.fields() {
if field.vis.node.is_pub() {
self.update(field.hir_id, item_level);
}
}
}
hir::ItemKind::ForeignMod(ref foreign_mod) => {
for foreign_item in &foreign_mod.items {
if foreign_item.vis.node.is_pub() {
self.update(foreign_item.hir_id, item_level);
}
}
}
hir::ItemKind::Existential(..) |
hir::ItemKind::Use(..) |
hir::ItemKind::Static(..) |
hir::ItemKind::Const(..) |
hir::ItemKind::GlobalAsm(..) |
hir::ItemKind::Ty(..) |
hir::ItemKind::Mod(..) |
hir::ItemKind::TraitAlias(..) |
hir::ItemKind::Fn(..) |
hir::ItemKind::ExternCrate(..) => {}
}
// Mark all items in interfaces of reachable items as reachable.
match item.node {
// The interface is empty.
hir::ItemKind::ExternCrate(..) => {}
// All nested items are checked by `visit_item`.
hir::ItemKind::Mod(..) => {}
// Re-exports are handled in `visit_mod`. However, in order to avoid looping over
// all of the items of a mod in `visit_mod` looking for use statements, we handle
// making sure that intermediate use statements have their visibilities updated here.
hir::ItemKind::Use(ref path, _) => {
if item_level.is_some() {
self.update_visibility_of_intermediate_use_statements(path.segments.as_ref());
}
}
// The interface is empty.
hir::ItemKind::GlobalAsm(..) => {}
hir::ItemKind::Existential(..) => {
// FIXME: This is some serious pessimization intended to workaround deficiencies
// in the reachability pass (`middle/reachable.rs`). Types are marked as link-time
// reachable if they are returned via `impl Trait`, even from private functions.
let exist_level = cmp::max(item_level, Some(AccessLevel::ReachableFromImplTrait));
self.reach(item.hir_id, exist_level).generics().predicates().ty();
}
// Visit everything.
hir::ItemKind::Const(..) | hir::ItemKind::Static(..) |
hir::ItemKind::Fn(..) | hir::ItemKind::Ty(..) => {
if item_level.is_some() {
self.reach(item.hir_id, item_level).generics().predicates().ty();
}
}
hir::ItemKind::Trait(.., ref trait_item_refs) => {
if item_level.is_some() {
self.reach(item.hir_id, item_level).generics().predicates();
for trait_item_ref in trait_item_refs {
let mut reach = self.reach(trait_item_ref.id.hir_id, item_level);
reach.generics().predicates();
if trait_item_ref.kind == AssocItemKind::Type &&
!trait_item_ref.defaultness.has_value() {
// No type to visit.
} else {
reach.ty();
}
}
}
}
hir::ItemKind::TraitAlias(..) => {
if item_level.is_some() {
self.reach(item.hir_id, item_level).generics().predicates();
}
}
// Visit everything except for private impl items.
hir::ItemKind::Impl(.., ref impl_item_refs) => {
if item_level.is_some() {
self.reach(item.hir_id, item_level).generics().predicates().ty().trait_ref();
for impl_item_ref in impl_item_refs {
let impl_item_level = self.get(impl_item_ref.id.hir_id);
if impl_item_level.is_some() {
self.reach(impl_item_ref.id.hir_id, impl_item_level)
.generics().predicates().ty();
}
}
}
}
// Visit everything, but enum variants have their own levels.
hir::ItemKind::Enum(ref def, _) => {
if item_level.is_some() {
self.reach(item.hir_id, item_level).generics().predicates();
}
for variant in &def.variants {
let variant_level = self.get(variant.node.id);
if variant_level.is_some() {
for field in variant.node.data.fields() {
self.reach(field.hir_id, variant_level).ty();
}
// Corner case: if the variant is reachable, but its
// enum is not, make the enum reachable as well.
self.update(item.hir_id, variant_level);
}
}
}
// Visit everything, but foreign items have their own levels.
hir::ItemKind::ForeignMod(ref foreign_mod) => {
for foreign_item in &foreign_mod.items {
let foreign_item_level = self.get(foreign_item.hir_id);
if foreign_item_level.is_some() {
self.reach(foreign_item.hir_id, foreign_item_level)
.generics().predicates().ty();
}
}
}
// Visit everything except for private fields.
hir::ItemKind::Struct(ref struct_def, _) |
hir::ItemKind::Union(ref struct_def, _) => {
if item_level.is_some() {
self.reach(item.hir_id, item_level).generics().predicates();
for field in struct_def.fields() {
let field_level = self.get(field.hir_id);
if field_level.is_some() {
self.reach(field.hir_id, field_level).ty();
}
}
}
}
}
let orig_level = mem::replace(&mut self.prev_level, item_level);
intravisit::walk_item(self, item);
self.prev_level = orig_level;
}
fn visit_block(&mut self, b: &'tcx hir::Block) {
// Blocks can have public items, for example impls, but they always
// start as completely private regardless of publicity of a function,
// constant, type, field, etc., in which this block resides.
let orig_level = mem::replace(&mut self.prev_level, None);
intravisit::walk_block(self, b);
self.prev_level = orig_level;
}
fn visit_mod(&mut self, m: &'tcx hir::Mod, _sp: Span, id: hir::HirId) {
// This code is here instead of in visit_item so that the
// crate module gets processed as well.
if self.prev_level.is_some() {
let def_id = self.tcx.hir().local_def_id(id);
if let Some(exports) = self.tcx.module_exports(def_id) {
for export in exports.iter() {
if export.vis == ty::Visibility::Public {
if let Some(def_id) = export.res.opt_def_id() {
if let Some(hir_id) = self.tcx.hir().as_local_hir_id(def_id) {
self.update(hir_id, Some(AccessLevel::Exported));
}
}
}
}
}
}
intravisit::walk_mod(self, m, id);
}
fn visit_macro_def(&mut self, md: &'tcx hir::MacroDef) {
if attr::find_transparency(&md.attrs, md.legacy).0 != Transparency::Opaque {
self.update(md.hir_id, Some(AccessLevel::Public));
return
}
let module_did = ty::DefIdTree::parent(
self.tcx,
self.tcx.hir().local_def_id(md.hir_id)
).unwrap();
let mut module_id = self.tcx.hir().as_local_hir_id(module_did).unwrap();
let level = if md.vis.node.is_pub() { self.get(module_id) } else { None };
let level = self.update(md.hir_id, level);
if level.is_none() {
return
}
loop {
let module = if module_id == hir::CRATE_HIR_ID {
&self.tcx.hir().krate().module
} else if let hir::ItemKind::Mod(ref module) =
self.tcx.hir().expect_item(module_id).node {
module
} else {
unreachable!()
};
for id in &module.item_ids {
self.update(id.id, level);
}
let def_id = self.tcx.hir().local_def_id(module_id);
if let Some(exports) = self.tcx.module_exports(def_id) {
for export in exports.iter() {
if let Some(hir_id) = self.tcx.hir().as_local_hir_id(export.res.def_id()) {
self.update(hir_id, level);
}
}
}
if module_id == hir::CRATE_HIR_ID {
break
}
module_id = self.tcx.hir().get_parent_node(module_id);
}
}
}
impl ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
fn generics(&mut self) -> &mut Self {
for param in &self.ev.tcx.generics_of(self.item_def_id).params {
match param.kind {
GenericParamDefKind::Lifetime => {}
GenericParamDefKind::Type { has_default, .. } => {
if has_default {
self.visit(self.ev.tcx.type_of(param.def_id));
}
}
GenericParamDefKind::Const => {
self.visit(self.ev.tcx.type_of(param.def_id));
}
}
}
self
}
fn predicates(&mut self) -> &mut Self {
self.visit_predicates(self.ev.tcx.predicates_of(self.item_def_id));
self
}
fn ty(&mut self) -> &mut Self {
self.visit(self.ev.tcx.type_of(self.item_def_id));
self
}
fn trait_ref(&mut self) -> &mut Self {
if let Some(trait_ref) = self.ev.tcx.impl_trait_ref(self.item_def_id) {
self.visit_trait(trait_ref);
}
self
}
}
impl DefIdVisitor<'tcx> for ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
fn tcx(&self) -> TyCtxt<'tcx> { self.ev.tcx }
fn visit_def_id(&mut self, def_id: DefId, _kind: &str, _descr: &dyn fmt::Display) -> bool {
if let Some(hir_id) = self.ev.tcx.hir().as_local_hir_id(def_id) {
self.ev.update(hir_id, self.access_level);
}
false
}
}
//////////////////////////////////////////////////////////////////////////////////////
/// Name privacy visitor, checks privacy and reports violations.
/// Most of name privacy checks are performed during the main resolution phase,
/// or later in type checking when field accesses and associated items are resolved.
/// This pass performs remaining checks for fields in struct expressions and patterns.
//////////////////////////////////////////////////////////////////////////////////////
struct NamePrivacyVisitor<'a, 'tcx> {
tcx: TyCtxt<'tcx>,
tables: &'a ty::TypeckTables<'tcx>,
current_item: hir::HirId,
empty_tables: &'a ty::TypeckTables<'tcx>,
}
impl<'a, 'tcx> NamePrivacyVisitor<'a, 'tcx> {
// Checks that a field in a struct constructor (expression or pattern) is accessible.
fn check_field(&mut self,
use_ctxt: Span, // syntax context of the field name at the use site
span: Span, // span of the field pattern, e.g., `x: 0`
def: &'tcx ty::AdtDef, // definition of the struct or enum
field: &'tcx ty::FieldDef) { // definition of the field
let ident = Ident::new(kw::Invalid, use_ctxt);
let current_hir = self.current_item;
let def_id = self.tcx.adjust_ident_and_get_scope(ident, def.did, current_hir).1;
if !def.is_enum() && !field.vis.is_accessible_from(def_id, self.tcx) {
struct_span_err!(self.tcx.sess, span, E0451, "field `{}` of {} `{}` is private",
field.ident, def.variant_descr(), self.tcx.def_path_str(def.did))
.span_label(span, format!("field `{}` is private", field.ident))
.emit();
}
}
}
impl<'a, 'tcx> Visitor<'tcx> for NamePrivacyVisitor<'a, 'tcx> {
/// We want to visit items in the context of their containing
/// module and so forth, so supply a crate for doing a deep walk.
fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
NestedVisitorMap::All(&self.tcx.hir())
}
fn visit_mod(&mut self, _m: &'tcx hir::Mod, _s: Span, _n: hir::HirId) {
// Don't visit nested modules, since we run a separate visitor walk
// for each module in `privacy_access_levels`
}
fn visit_nested_body(&mut self, body: hir::BodyId) {
let orig_tables = mem::replace(&mut self.tables, self.tcx.body_tables(body));
let body = self.tcx.hir().body(body);
self.visit_body(body);
self.tables = orig_tables;
}
fn visit_item(&mut self, item: &'tcx hir::Item) {
let orig_current_item = mem::replace(&mut self.current_item, item.hir_id);
let orig_tables =
mem::replace(&mut self.tables, item_tables(self.tcx, item.hir_id, self.empty_tables));
intravisit::walk_item(self, item);
self.current_item = orig_current_item;
self.tables = orig_tables;
}
fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem) {
let orig_tables =
mem::replace(&mut self.tables, item_tables(self.tcx, ti.hir_id, self.empty_tables));
intravisit::walk_trait_item(self, ti);
self.tables = orig_tables;
}
fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem) {
let orig_tables =
mem::replace(&mut self.tables, item_tables(self.tcx, ii.hir_id, self.empty_tables));
intravisit::walk_impl_item(self, ii);
self.tables = orig_tables;
}
fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
match expr.node {
hir::ExprKind::Struct(ref qpath, ref fields, ref base) => {
let res = self.tables.qpath_res(qpath, expr.hir_id);
let adt = self.tables.expr_ty(expr).ty_adt_def().unwrap();
let variant = adt.variant_of_res(res);
if let Some(ref base) = *base {
// If the expression uses FRU we need to make sure all the unmentioned fields
// are checked for privacy (RFC 736). Rather than computing the set of
// unmentioned fields, just check them all.
for (vf_index, variant_field) in variant.fields.iter().enumerate() {
let field = fields.iter().find(|f| {
self.tcx.field_index(f.hir_id, self.tables) == vf_index
});
let (use_ctxt, span) = match field {
Some(field) => (field.ident.span, field.span),
None => (base.span, base.span),
};
self.check_field(use_ctxt, span, adt, variant_field);
}
} else {
for field in fields {
let use_ctxt = field.ident.span;
let index = self.tcx.field_index(field.hir_id, self.tables);
self.check_field(use_ctxt, field.span, adt, &variant.fields[index]);
}
}
}
_ => {}
}
intravisit::walk_expr(self, expr);
}
fn visit_pat(&mut self, pat: &'tcx hir::Pat) {
match pat.node {
PatKind::Struct(ref qpath, ref fields, _) => {
let res = self.tables.qpath_res(qpath, pat.hir_id);
let adt = self.tables.pat_ty(pat).ty_adt_def().unwrap();
let variant = adt.variant_of_res(res);
for field in fields {
let use_ctxt = field.node.ident.span;
let index = self.tcx.field_index(field.node.hir_id, self.tables);
self.check_field(use_ctxt, field.span, adt, &variant.fields[index]);
}
}
_ => {}
}
intravisit::walk_pat(self, pat);
}
}
////////////////////////////////////////////////////////////////////////////////////////////
/// Type privacy visitor, checks types for privacy and reports violations.
/// Both explicitly written types and inferred types of expressions and patters are checked.
/// Checks are performed on "semantic" types regardless of names and their hygiene.
////////////////////////////////////////////////////////////////////////////////////////////
struct TypePrivacyVisitor<'a, 'tcx> {
tcx: TyCtxt<'tcx>,
tables: &'a ty::TypeckTables<'tcx>,
current_item: DefId,
in_body: bool,
span: Span,
empty_tables: &'a ty::TypeckTables<'tcx>,
}
impl<'a, 'tcx> TypePrivacyVisitor<'a, 'tcx> {
fn item_is_accessible(&self, did: DefId) -> bool {
def_id_visibility(self.tcx, did).0.is_accessible_from(self.current_item, self.tcx)
}
// Take node-id of an expression or pattern and check its type for privacy.
fn check_expr_pat_type(&mut self, id: hir::HirId, span: Span) -> bool {
self.span = span;
if self.visit(self.tables.node_type(id)) || self.visit(self.tables.node_substs(id)) {
return true;
}
if let Some(adjustments) = self.tables.adjustments().get(id) {
for adjustment in adjustments {
if self.visit(adjustment.target) {
return true;
}
}
}
false
}
fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
let is_error = !self.item_is_accessible(def_id);
if is_error {
self.tcx.sess.span_err(self.span, &format!("{} `{}` is private", kind, descr));
}
is_error
}
}
impl<'a, 'tcx> Visitor<'tcx> for TypePrivacyVisitor<'a, 'tcx> {
/// We want to visit items in the context of their containing
/// module and so forth, so supply a crate for doing a deep walk.
fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
NestedVisitorMap::All(&self.tcx.hir())
}
fn visit_mod(&mut self, _m: &'tcx hir::Mod, _s: Span, _n: hir::HirId) {
// Don't visit nested modules, since we run a separate visitor walk
// for each module in `privacy_access_levels`
}
fn visit_nested_body(&mut self, body: hir::BodyId) {
let orig_tables = mem::replace(&mut self.tables, self.tcx.body_tables(body));
let orig_in_body = mem::replace(&mut self.in_body, true);
let body = self.tcx.hir().body(body);
self.visit_body(body);
self.tables = orig_tables;
self.in_body = orig_in_body;
}
fn visit_ty(&mut self, hir_ty: &'tcx hir::Ty) {
self.span = hir_ty.span;
if self.in_body {
// Types in bodies.
if self.visit(self.tables.node_type(hir_ty.hir_id)) {
return;
}
} else {
// Types in signatures.
// FIXME: This is very ineffective. Ideally each HIR type should be converted
// into a semantic type only once and the result should be cached somehow.
if self.visit(rustc_typeck::hir_ty_to_ty(self.tcx, hir_ty)) {
return;
}
}
intravisit::walk_ty(self, hir_ty);
}
fn visit_trait_ref(&mut self, trait_ref: &'tcx hir::TraitRef) {
self.span = trait_ref.path.span;
if !self.in_body {
// Avoid calling `hir_trait_to_predicates` in bodies, it will ICE.
// The traits' privacy in bodies is already checked as a part of trait object types.
let (principal, bounds) = rustc_typeck::hir_trait_to_predicates(self.tcx, trait_ref);
if self.visit_trait(*principal.skip_binder()) {
return;
}
for (poly_predicate, _) in bounds.projection_bounds {
let tcx = self.tcx;
if self.visit(poly_predicate.skip_binder().ty) ||
self.visit_trait(poly_predicate.skip_binder().projection_ty.trait_ref(tcx)) {
return;
}
}
}
intravisit::walk_trait_ref(self, trait_ref);
}
// Check types of expressions
fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
if self.check_expr_pat_type(expr.hir_id, expr.span) {
// Do not check nested expressions if the error already happened.
return;
}
match expr.node {
hir::ExprKind::Assign(.., ref rhs) | hir::ExprKind::Match(ref rhs, ..) => {
// Do not report duplicate errors for `x = y` and `match x { ... }`.
if self.check_expr_pat_type(rhs.hir_id, rhs.span) {
return;
}
}
hir::ExprKind::MethodCall(_, span, _) => {
// Method calls have to be checked specially.
self.span = span;
if let Some(def_id) = self.tables.type_dependent_def_id(expr.hir_id) {
if self.visit(self.tcx.type_of(def_id)) {
return;
}
} else {
self.tcx.sess.delay_span_bug(expr.span,
"no type-dependent def for method call");
}
}
_ => {}
}
intravisit::walk_expr(self, expr);
}
// Prohibit access to associated items with insufficient nominal visibility.
//
// Additionally, until better reachability analysis for macros 2.0 is available,
// we prohibit access to private statics from other crates, this allows to give
// more code internal visibility at link time. (Access to private functions
// is already prohibited by type privacy for function types.)
fn visit_qpath(&mut self, qpath: &'tcx hir::QPath, id: hir::HirId, span: Span) {
let def = match self.tables.qpath_res(qpath, id) {
Res::Def(kind, def_id) => Some((kind, def_id)),
_ => None,
};
let def = def.filter(|(kind, _)| {
match kind {
DefKind::Method
| DefKind::AssocConst
| DefKind::AssocTy
| DefKind::AssocExistential
| DefKind::Static => true,
_ => false,
}
});
if let Some((kind, def_id)) = def {
let is_local_static = if let DefKind::Static = kind {
def_id.is_local()
} else { false };
if !self.item_is_accessible(def_id) && !is_local_static {
let name = match *qpath {
hir::QPath::Resolved(_, ref path) => path.to_string(),
hir::QPath::TypeRelative(_, ref segment) => segment.ident.to_string(),
};
let msg = format!("{} `{}` is private", kind.descr(), name);
self.tcx.sess.span_err(span, &msg);
return;
}
}
intravisit::walk_qpath(self, qpath, id, span);
}
// Check types of patterns.
fn visit_pat(&mut self, pattern: &'tcx hir::Pat) {
if self.check_expr_pat_type(pattern.hir_id, pattern.span) {
// Do not check nested patterns if the error already happened.
return;
}
intravisit::walk_pat(self, pattern);
}
fn visit_local(&mut self, local: &'tcx hir::Local) {
if let Some(ref init) = local.init {
if self.check_expr_pat_type(init.hir_id, init.span) {
// Do not report duplicate errors for `let x = y`.
return;
}
}
intravisit::walk_local(self, local);
}
// Check types in item interfaces.
fn visit_item(&mut self, item: &'tcx hir::Item) {
let orig_current_item = mem::replace(&mut self.current_item,
self.tcx.hir().local_def_id(item.hir_id));
let orig_in_body = mem::replace(&mut self.in_body, false);
let orig_tables =
mem::replace(&mut self.tables, item_tables(self.tcx, item.hir_id, self.empty_tables));
intravisit::walk_item(self, item);
self.tables = orig_tables;
self.in_body = orig_in_body;
self.current_item = orig_current_item;
}
fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem) {
let orig_tables =
mem::replace(&mut self.tables, item_tables(self.tcx, ti.hir_id, self.empty_tables));
intravisit::walk_trait_item(self, ti);
self.tables = orig_tables;
}
fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem) {
let orig_tables =
mem::replace(&mut self.tables, item_tables(self.tcx, ii.hir_id, self.empty_tables));
intravisit::walk_impl_item(self, ii);
self.tables = orig_tables;
}
}
impl DefIdVisitor<'tcx> for TypePrivacyVisitor<'a, 'tcx> {
fn tcx(&self) -> TyCtxt<'tcx> { self.tcx }
fn visit_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
self.check_def_id(def_id, kind, descr)
}
}
///////////////////////////////////////////////////////////////////////////////
/// Obsolete visitors for checking for private items in public interfaces.
/// These visitors are supposed to be kept in frozen state and produce an
/// "old error node set". For backward compatibility the new visitor reports
/// warnings instead of hard errors when the erroneous node is not in this old set.
///////////////////////////////////////////////////////////////////////////////
struct ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
tcx: TyCtxt<'tcx>,
access_levels: &'a AccessLevels,
in_variant: bool,
// Set of errors produced by this obsolete visitor.
old_error_set: HirIdSet,
}
struct ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
inner: &'a ObsoleteVisiblePrivateTypesVisitor<'b, 'tcx>,
/// Whether the type refers to private types.
contains_private: bool,
/// Whether we've recurred at all (i.e., if we're pointing at the
/// first type on which `visit_ty` was called).
at_outer_type: bool,
/// Whether that first type is a public path.
outer_type_is_public_path: bool,
}
impl<'a, 'tcx> ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
fn path_is_private_type(&self, path: &hir::Path) -> bool {
let did = match path.res {
Res::PrimTy(..) | Res::SelfTy(..) | Res::Err => return false,
res => res.def_id(),
};
// A path can only be private if:
// it's in this crate...
if let Some(hir_id) = self.tcx.hir().as_local_hir_id(did) {
// .. and it corresponds to a private type in the AST (this returns
// `None` for type parameters).
match self.tcx.hir().find(hir_id) {
Some(Node::Item(ref item)) => !item.vis.node.is_pub(),
Some(_) | None => false,
}
} else {
return false
}
}
fn trait_is_public(&self, trait_id: hir::HirId) -> bool {
// FIXME: this would preferably be using `exported_items`, but all
// traits are exported currently (see `EmbargoVisitor.exported_trait`).
self.access_levels.is_public(trait_id)
}
fn check_generic_bound(&mut self, bound: &hir::GenericBound) {
if let hir::GenericBound::Trait(ref trait_ref, _) = *bound {
if self.path_is_private_type(&trait_ref.trait_ref.path) {
self.old_error_set.insert(trait_ref.trait_ref.hir_ref_id);
}
}
}
fn item_is_public(&self, id: &hir::HirId, vis: &hir::Visibility) -> bool {
self.access_levels.is_reachable(*id) || vis.node.is_pub()
}
}
impl<'a, 'b, 'tcx, 'v> Visitor<'v> for ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'v> {
NestedVisitorMap::None
}
fn visit_ty(&mut self, ty: &hir::Ty) {
if let hir::TyKind::Path(hir::QPath::Resolved(_, ref path)) = ty.node {
if self.inner.path_is_private_type(path) {
self.contains_private = true;
// Found what we're looking for, so let's stop working.
return
}
}
if let hir::TyKind::Path(_) = ty.node {
if self.at_outer_type {
self.outer_type_is_public_path = true;
}
}
self.at_outer_type = false;
intravisit::walk_ty(self, ty)
}
// Don't want to recurse into `[, .. expr]`.
fn visit_expr(&mut self, _: &hir::Expr) {}
}
impl<'a, 'tcx> Visitor<'tcx> for ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
/// We want to visit items in the context of their containing
/// module and so forth, so supply a crate for doing a deep walk.
fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
NestedVisitorMap::All(&self.tcx.hir())
}
fn visit_item(&mut self, item: &'tcx hir::Item) {
match item.node {
// Contents of a private mod can be re-exported, so we need
// to check internals.
hir::ItemKind::Mod(_) => {}
// An `extern {}` doesn't introduce a new privacy
// namespace (the contents have their own privacies).
hir::ItemKind::ForeignMod(_) => {}
hir::ItemKind::Trait(.., ref bounds, _) => {
if !self.trait_is_public(item.hir_id) {
return
}
for bound in bounds.iter() {
self.check_generic_bound(bound)
}
}
// Impls need some special handling to try to offer useful
// error messages without (too many) false positives
// (i.e., we could just return here to not check them at
// all, or some worse estimation of whether an impl is
// publicly visible).
hir::ItemKind::Impl(.., ref g, ref trait_ref, ref self_, ref impl_item_refs) => {
// `impl [... for] Private` is never visible.
let self_contains_private;
// `impl [... for] Public<...>`, but not `impl [... for]
// Vec<Public>` or `(Public,)`, etc.
let self_is_public_path;
// Check the properties of the `Self` type:
{
let mut visitor = ObsoleteCheckTypeForPrivatenessVisitor {
inner: self,
contains_private: false,
at_outer_type: true,
outer_type_is_public_path: false,
};
visitor.visit_ty(&self_);
self_contains_private = visitor.contains_private;
self_is_public_path = visitor.outer_type_is_public_path;
}
// Miscellaneous info about the impl:
// `true` iff this is `impl Private for ...`.
let not_private_trait =
trait_ref.as_ref().map_or(true, // no trait counts as public trait
|tr| {
let did = tr.path.res.def_id();
if let Some(hir_id) = self.tcx.hir().as_local_hir_id(did) {
self.trait_is_public(hir_id)
} else {
true // external traits must be public
}
});
// `true` iff this is a trait impl or at least one method is public.
//
// `impl Public { $( fn ...() {} )* }` is not visible.
//
// This is required over just using the methods' privacy
// directly because we might have `impl<T: Foo<Private>> ...`,
// and we shouldn't warn about the generics if all the methods
// are private (because `T` won't be visible externally).
let trait_or_some_public_method =
trait_ref.is_some() ||
impl_item_refs.iter()
.any(|impl_item_ref| {
let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
match impl_item.node {
hir::ImplItemKind::Const(..) |
hir::ImplItemKind::Method(..) => {
self.access_levels.is_reachable(
impl_item_ref.id.hir_id)
}
hir::ImplItemKind::Existential(..) |
hir::ImplItemKind::Type(_) => false,
}
});
if !self_contains_private &&
not_private_trait &&
trait_or_some_public_method {
intravisit::walk_generics(self, g);
match *trait_ref {
None => {
for impl_item_ref in impl_item_refs {
// This is where we choose whether to walk down
// further into the impl to check its items. We
// should only walk into public items so that we
// don't erroneously report errors for private
// types in private items.
let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
match impl_item.node {
hir::ImplItemKind::Const(..) |
hir::ImplItemKind::Method(..)
if self.item_is_public(&impl_item.hir_id, &impl_item.vis) =>
{
intravisit::walk_impl_item(self, impl_item)
}
hir::ImplItemKind::Type(..) => {
intravisit::walk_impl_item(self, impl_item)
}
_ => {}
}
}
}
Some(ref tr) => {
// Any private types in a trait impl fall into three
// categories.
// 1. mentioned in the trait definition
// 2. mentioned in the type params/generics
// 3. mentioned in the associated types of the impl
//
// Those in 1. can only occur if the trait is in
// this crate and will've been warned about on the
// trait definition (there's no need to warn twice
// so we don't check the methods).
//
// Those in 2. are warned via walk_generics and this
// call here.
intravisit::walk_path(self, &tr.path);
// Those in 3. are warned with this call.
for impl_item_ref in impl_item_refs {
let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
if let hir::ImplItemKind::Type(ref ty) = impl_item.node {
self.visit_ty(ty);
}
}
}
}
} else if trait_ref.is_none() && self_is_public_path {
// `impl Public<Private> { ... }`. Any public static
// methods will be visible as `Public::foo`.
let mut found_pub_static = false;
for impl_item_ref in impl_item_refs {
if self.item_is_public(&impl_item_ref.id.hir_id, &impl_item_ref.vis) {
let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
match impl_item_ref.kind {
AssocItemKind::Const => {
found_pub_static = true;
intravisit::walk_impl_item(self, impl_item);
}
AssocItemKind::Method { has_self: false } => {
found_pub_static = true;
intravisit::walk_impl_item(self, impl_item);
}
_ => {}
}
}
}
if found_pub_static {
intravisit::walk_generics(self, g)
}
}
return
}
// `type ... = ...;` can contain private types, because
// we're introducing a new name.
hir::ItemKind::Ty(..) => return,
// Not at all public, so we don't care.
_ if !self.item_is_public(&item.hir_id, &item.vis) => {
return;
}
_ => {}
}
// We've carefully constructed it so that if we're here, then
// any `visit_ty`'s will be called on things that are in
// public signatures, i.e., things that we're interested in for
// this visitor.
intravisit::walk_item(self, item);
}
fn visit_generics(&mut self, generics: &'tcx hir::Generics) {
for param in &generics.params {
for bound in &param.bounds {
self.check_generic_bound(bound);
}
}
for predicate in &generics.where_clause.predicates {
match predicate {
hir::WherePredicate::BoundPredicate(bound_pred) => {
for bound in bound_pred.bounds.iter() {
self.check_generic_bound(bound)
}
}
hir::WherePredicate::RegionPredicate(_) => {}
hir::WherePredicate::EqPredicate(eq_pred) => {
self.visit_ty(&eq_pred.rhs_ty);
}
}
}
}
fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem) {
if self.access_levels.is_reachable(item.hir_id) {
intravisit::walk_foreign_item(self, item)
}
}
fn visit_ty(&mut self, t: &'tcx hir::Ty) {
if let hir::TyKind::Path(hir::QPath::Resolved(_, ref path)) = t.node {
if self.path_is_private_type(path) {
self.old_error_set.insert(t.hir_id);
}
}
intravisit::walk_ty(self, t)
}
fn visit_variant(&mut self,
v: &'tcx hir::Variant,
g: &'tcx hir::Generics,
item_id: hir::HirId) {
if self.access_levels.is_reachable(v.node.id) {
self.in_variant = true;
intravisit::walk_variant(self, v, g, item_id);
self.in_variant = false;
}
}
fn visit_struct_field(&mut self, s: &'tcx hir::StructField) {
if s.vis.node.is_pub() || self.in_variant {
intravisit::walk_struct_field(self, s);
}
}
// We don't need to introspect into these at all: an
// expression/block context can't possibly contain exported things.
// (Making them no-ops stops us from traversing the whole AST without
// having to be super careful about our `walk_...` calls above.)
fn visit_block(&mut self, _: &'tcx hir::Block) {}
fn visit_expr(&mut self, _: &'tcx hir::Expr) {}
}
///////////////////////////////////////////////////////////////////////////////
/// SearchInterfaceForPrivateItemsVisitor traverses an item's interface and
/// finds any private components in it.
/// PrivateItemsInPublicInterfacesVisitor ensures there are no private types
/// and traits in public interfaces.
///////////////////////////////////////////////////////////////////////////////
struct SearchInterfaceForPrivateItemsVisitor<'tcx> {
tcx: TyCtxt<'tcx>,
item_id: hir::HirId,
item_def_id: DefId,
span: Span,
/// The visitor checks that each component type is at least this visible.
required_visibility: ty::Visibility,
has_pub_restricted: bool,
has_old_errors: bool,
in_assoc_ty: bool,
}
impl SearchInterfaceForPrivateItemsVisitor<'tcx> {
fn generics(&mut self) -> &mut Self {
for param in &self.tcx.generics_of(self.item_def_id).params {
match param.kind {
GenericParamDefKind::Lifetime => {}
GenericParamDefKind::Type { has_default, .. } => {
if has_default {
self.visit(self.tcx.type_of(param.def_id));
}
}
GenericParamDefKind::Const => {
self.visit(self.tcx.type_of(param.def_id));
}
}
}
self
}
fn predicates(&mut self) -> &mut Self {
// N.B., we use `explicit_predicates_of` and not `predicates_of`
// because we don't want to report privacy errors due to where
// clauses that the compiler inferred. We only want to
// consider the ones that the user wrote. This is important
// for the inferred outlives rules; see
// `src/test/ui/rfc-2093-infer-outlives/privacy.rs`.
self.visit_predicates(self.tcx.explicit_predicates_of(self.item_def_id));
self
}
fn ty(&mut self) -> &mut Self {
self.visit(self.tcx.type_of(self.item_def_id));
self
}
fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
if self.leaks_private_dep(def_id) {
self.tcx.lint_hir(lint::builtin::EXPORTED_PRIVATE_DEPENDENCIES,
self.item_id,
self.span,
&format!("{} `{}` from private dependency '{}' in public \
interface", kind, descr,
self.tcx.crate_name(def_id.krate)));
}
let hir_id = match self.tcx.hir().as_local_hir_id(def_id) {
Some(hir_id) => hir_id,
None => return false,
};
let (vis, vis_span, vis_descr) = def_id_visibility(self.tcx, def_id);
if !vis.is_at_least(self.required_visibility, self.tcx) {
let msg = format!("{} {} `{}` in public interface", vis_descr, kind, descr);
if self.has_pub_restricted || self.has_old_errors || self.in_assoc_ty {
let mut err = if kind == "trait" {
struct_span_err!(self.tcx.sess, self.span, E0445, "{}", msg)
} else {
struct_span_err!(self.tcx.sess, self.span, E0446, "{}", msg)
};
err.span_label(self.span, format!("can't leak {} {}", vis_descr, kind));
err.span_label(vis_span, format!("`{}` declared as {}", descr, vis_descr));
err.emit();
} else {
let err_code = if kind == "trait" { "E0445" } else { "E0446" };
self.tcx.lint_hir(lint::builtin::PRIVATE_IN_PUBLIC, hir_id, self.span,
&format!("{} (error {})", msg, err_code));
}
}
false
}
/// An item is 'leaked' from a private dependency if all
/// of the following are true:
/// 1. It's contained within a public type
/// 2. It comes from a private crate
fn leaks_private_dep(&self, item_id: DefId) -> bool {
let ret = self.required_visibility == ty::Visibility::Public &&
self.tcx.is_private_dep(item_id.krate);
log::debug!("leaks_private_dep(item_id={:?})={}", item_id, ret);
return ret;
}
}
impl DefIdVisitor<'tcx> for SearchInterfaceForPrivateItemsVisitor<'tcx> {
fn tcx(&self) -> TyCtxt<'tcx> { self.tcx }
fn visit_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
self.check_def_id(def_id, kind, descr)
}
}
struct PrivateItemsInPublicInterfacesVisitor<'a, 'tcx> {
tcx: TyCtxt<'tcx>,
has_pub_restricted: bool,
old_error_set: &'a HirIdSet,
}
impl<'a, 'tcx> PrivateItemsInPublicInterfacesVisitor<'a, 'tcx> {
fn check(
&self,
item_id: hir::HirId,
required_visibility: ty::Visibility,
) -> SearchInterfaceForPrivateItemsVisitor<'tcx> {
let mut has_old_errors = false;
// Slow path taken only if there any errors in the crate.
for &id in self.old_error_set {
// Walk up the nodes until we find `item_id` (or we hit a root).
let mut id = id;
loop {
if id == item_id {
has_old_errors = true;
break;
}
let parent = self.tcx.hir().get_parent_node(id);
if parent == id {
break;
}
id = parent;
}
if has_old_errors {
break;
}
}
SearchInterfaceForPrivateItemsVisitor {
tcx: self.tcx,
item_id,
item_def_id: self.tcx.hir().local_def_id(item_id),
span: self.tcx.hir().span(item_id),
required_visibility,
has_pub_restricted: self.has_pub_restricted,
has_old_errors,
in_assoc_ty: false,
}
}
fn check_assoc_item(
&self,
hir_id: hir::HirId,
assoc_item_kind: AssocItemKind,
defaultness: hir::Defaultness,
vis: ty::Visibility,
) {
let mut check = self.check(hir_id, vis);
let (check_ty, is_assoc_ty) = match assoc_item_kind {
AssocItemKind::Const | AssocItemKind::Method { .. } => (true, false),
AssocItemKind::Type => (defaultness.has_value(), true),
// `ty()` for existential types is the underlying type,
// it's not a part of interface, so we skip it.
AssocItemKind::Existential => (false, true),
};
check.in_assoc_ty = is_assoc_ty;
check.generics().predicates();
if check_ty {
check.ty();
}
}
}
impl<'a, 'tcx> Visitor<'tcx> for PrivateItemsInPublicInterfacesVisitor<'a, 'tcx> {
fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
NestedVisitorMap::OnlyBodies(&self.tcx.hir())
}
fn visit_item(&mut self, item: &'tcx hir::Item) {
let tcx = self.tcx;
let item_visibility = ty::Visibility::from_hir(&item.vis, item.hir_id, tcx);
match item.node {
// Crates are always public.
hir::ItemKind::ExternCrate(..) => {}
// All nested items are checked by `visit_item`.
hir::ItemKind::Mod(..) => {}
// Checked in resolve.
hir::ItemKind::Use(..) => {}
// No subitems.
hir::ItemKind::GlobalAsm(..) => {}
// Subitems of these items have inherited publicity.
hir::ItemKind::Const(..) | hir::ItemKind::Static(..) |
hir::ItemKind::Fn(..) | hir::ItemKind::Ty(..) => {
self.check(item.hir_id, item_visibility).generics().predicates().ty();
}
hir::ItemKind::Existential(..) => {
// `ty()` for existential types is the underlying type,
// it's not a part of interface, so we skip it.
self.check(item.hir_id, item_visibility).generics().predicates();
}
hir::ItemKind::Trait(.., ref trait_item_refs) => {
self.check(item.hir_id, item_visibility).generics().predicates();
for trait_item_ref in trait_item_refs {
self.check_assoc_item(
trait_item_ref.id.hir_id,
trait_item_ref.kind,
trait_item_ref.defaultness,
item_visibility,
);
}
}
hir::ItemKind::TraitAlias(..) => {
self.check(item.hir_id, item_visibility).generics().predicates();
}
hir::ItemKind::Enum(ref def, _) => {
self.check(item.hir_id, item_visibility).generics().predicates();
for variant in &def.variants {
for field in variant.node.data.fields() {
self.check(field.hir_id, item_visibility).ty();
}
}
}
// Subitems of foreign modules have their own publicity.
hir::ItemKind::ForeignMod(ref foreign_mod) => {
for foreign_item in &foreign_mod.items {
let vis = ty::Visibility::from_hir(&foreign_item.vis, item.hir_id, tcx);
self.check(foreign_item.hir_id, vis).generics().predicates().ty();
}
}
// Subitems of structs and unions have their own publicity.
hir::ItemKind::Struct(ref struct_def, _) |
hir::ItemKind::Union(ref struct_def, _) => {
self.check(item.hir_id, item_visibility).generics().predicates();
for field in struct_def.fields() {
let field_visibility = ty::Visibility::from_hir(&field.vis, item.hir_id, tcx);
self.check(field.hir_id, min(item_visibility, field_visibility, tcx)).ty();
}
}
// An inherent impl is public when its type is public
// Subitems of inherent impls have their own publicity.
// A trait impl is public when both its type and its trait are public
// Subitems of trait impls have inherited publicity.
hir::ItemKind::Impl(.., ref trait_ref, _, ref impl_item_refs) => {
let impl_vis = ty::Visibility::of_impl(item.hir_id, tcx, &Default::default());
self.check(item.hir_id, impl_vis).generics().predicates();
for impl_item_ref in impl_item_refs {
let impl_item = tcx.hir().impl_item(impl_item_ref.id);
let impl_item_vis = if trait_ref.is_none() {
min(ty::Visibility::from_hir(&impl_item.vis, item.hir_id, tcx),
impl_vis,
tcx)
} else {
impl_vis
};
self.check_assoc_item(
impl_item_ref.id.hir_id,
impl_item_ref.kind,
impl_item_ref.defaultness,
impl_item_vis,
);
}
}
}
}
}
pub fn provide(providers: &mut Providers<'_>) {
*providers = Providers {
privacy_access_levels,
check_private_in_public,
check_mod_privacy,
..*providers
};
}
fn check_mod_privacy(tcx: TyCtxt<'_>, module_def_id: DefId) {
let empty_tables = ty::TypeckTables::empty(None);
// Check privacy of names not checked in previous compilation stages.
let mut visitor = NamePrivacyVisitor {
tcx,
tables: &empty_tables,
current_item: hir::DUMMY_HIR_ID,
empty_tables: &empty_tables,
};
let (module, span, hir_id) = tcx.hir().get_module(module_def_id);
intravisit::walk_mod(&mut visitor, module, hir_id);
// Check privacy of explicitly written types and traits as well as
// inferred types of expressions and patterns.
let mut visitor = TypePrivacyVisitor {
tcx,
tables: &empty_tables,
current_item: module_def_id,
in_body: false,
span,
empty_tables: &empty_tables,
};
intravisit::walk_mod(&mut visitor, module, hir_id);
}
fn privacy_access_levels(tcx: TyCtxt<'_>, krate: CrateNum) -> &AccessLevels {
assert_eq!(krate, LOCAL_CRATE);
// Build up a set of all exported items in the AST. This is a set of all
// items which are reachable from external crates based on visibility.
let mut visitor = EmbargoVisitor {
tcx,
access_levels: Default::default(),
prev_level: Some(AccessLevel::Public),
changed: false,
};
loop {
intravisit::walk_crate(&mut visitor, tcx.hir().krate());
if visitor.changed {
visitor.changed = false;
} else {
break
}
}
visitor.update(hir::CRATE_HIR_ID, Some(AccessLevel::Public));
tcx.arena.alloc(visitor.access_levels)
}
fn check_private_in_public(tcx: TyCtxt<'_>, krate: CrateNum) {
assert_eq!(krate, LOCAL_CRATE);
let access_levels = tcx.privacy_access_levels(LOCAL_CRATE);
let krate = tcx.hir().krate();
let mut visitor = ObsoleteVisiblePrivateTypesVisitor {
tcx,
access_levels: &access_levels,
in_variant: false,
old_error_set: Default::default(),
};
intravisit::walk_crate(&mut visitor, krate);
let has_pub_restricted = {
let mut pub_restricted_visitor = PubRestrictedVisitor {
tcx,
has_pub_restricted: false
};
intravisit::walk_crate(&mut pub_restricted_visitor, krate);
pub_restricted_visitor.has_pub_restricted
};
// Check for private types and traits in public interfaces.
let mut visitor = PrivateItemsInPublicInterfacesVisitor {
tcx,
has_pub_restricted,
old_error_set: &visitor.old_error_set,
};
krate.visit_all_item_likes(&mut DeepVisitor::new(&mut visitor));
}
__build_diagnostic_array! { librustc_privacy, DIAGNOSTICS }
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