rust/compiler/rustc_resolve/src/access_levels.rs
2022-06-14 22:44:27 +02:00

238 lines
9.0 KiB
Rust

use rustc_ast::ast;
use rustc_ast::visit;
use rustc_ast::visit::Visitor;
use rustc_ast::Crate;
use rustc_ast::EnumDef;
use rustc_ast::ForeignMod;
use rustc_ast::NodeId;
use rustc_hir::def_id::LocalDefId;
use rustc_hir::def_id::CRATE_DEF_ID;
use rustc_middle::middle::privacy::AccessLevel;
use rustc_middle::ty::Visibility;
use rustc_span::sym;
use crate::imports::ImportKind;
use crate::BindingKey;
use crate::NameBinding;
use crate::NameBindingKind;
use crate::Resolver;
pub struct AccessLevelsVisitor<'r, 'a> {
r: &'r mut Resolver<'a>,
prev_level: Option<AccessLevel>,
changed: bool,
}
impl<'r, 'a> AccessLevelsVisitor<'r, 'a> {
/// Fills the `Resolver::access_levels` table with public & exported items
/// For now, this doesn't resolve macros (FIXME) and cannot resolve Impl, as we
/// need access to a TyCtxt for that.
pub fn compute_access_levels<'c>(r: &'r mut Resolver<'a>, krate: &'c Crate) {
let mut visitor =
AccessLevelsVisitor { r, changed: false, prev_level: Some(AccessLevel::Public) };
visitor.set_access_level_def_id(CRATE_DEF_ID, Some(AccessLevel::Public));
visitor.set_exports_access_level(CRATE_DEF_ID);
while visitor.changed {
visitor.reset();
visit::walk_crate(&mut visitor, krate);
}
tracing::info!("resolve::access_levels: {:#?}", r.access_levels);
}
fn reset(&mut self) {
self.changed = false;
self.prev_level = Some(AccessLevel::Public);
}
/// Update the access level of the exports of the given module accordingly. The module access
/// level has to be Exported or Public.
/// This will also follow `use` chains (see PrivacyVisitor::set_import_binding_access_level).
fn set_exports_access_level(&mut self, module_id: LocalDefId) {
assert!(self.r.module_map.contains_key(&&module_id.to_def_id()));
// Set the given binding access level to `AccessLevel::Public` and
// sets the rest of the `use` chain to `AccessLevel::Exported` until
// we hit the actual exported item.
let set_import_binding_access_level =
|this: &mut Self, mut binding: &NameBinding<'a>, mut access_level| {
while let NameBindingKind::Import { binding: nested_binding, import, .. } =
binding.kind
{
this.set_access_level(import.id, access_level);
if let ImportKind::Single { additional_ids, .. } = import.kind {
this.set_access_level(additional_ids.0, access_level);
this.set_access_level(additional_ids.1, access_level);
}
access_level = Some(AccessLevel::Exported);
binding = nested_binding;
}
};
let module_level = self.r.access_levels.map.get(&module_id).copied();
assert!(module_level >= Some(AccessLevel::Exported));
if let Some(exports) = self.r.reexport_map.get(&module_id) {
let pub_exports = exports
.iter()
.filter(|ex| ex.vis == Visibility::Public)
.cloned()
.collect::<Vec<_>>();
let module = self.r.get_module(module_id.to_def_id()).unwrap();
for export in pub_exports.into_iter() {
if let Some(export_def_id) = export.res.opt_def_id().and_then(|id| id.as_local()) {
self.set_access_level_def_id(export_def_id, Some(AccessLevel::Exported));
}
if let Some(ns) = export.res.ns() {
let key = BindingKey { ident: export.ident, ns, disambiguator: 0 };
let name_res = self.r.resolution(module, key);
if let Some(binding) = name_res.borrow().binding() {
set_import_binding_access_level(self, binding, module_level)
}
}
}
}
}
/// Sets the access level of the `LocalDefId` corresponding to the given `NodeId`.
/// This function will panic if the `NodeId` does not have a `LocalDefId`
fn set_access_level(
&mut self,
node_id: NodeId,
access_level: Option<AccessLevel>,
) -> Option<AccessLevel> {
self.set_access_level_def_id(self.r.local_def_id(node_id), access_level)
}
fn set_access_level_def_id(
&mut self,
def_id: LocalDefId,
access_level: Option<AccessLevel>,
) -> Option<AccessLevel> {
let old_level = self.r.access_levels.map.get(&def_id).copied();
if old_level < access_level {
self.r.access_levels.map.insert(def_id, access_level.unwrap());
self.changed = true;
access_level
} else {
old_level
}
}
}
impl<'r, 'ast> Visitor<'ast> for AccessLevelsVisitor<'ast, 'r> {
fn visit_item(&mut self, item: &'ast ast::Item) {
let inherited_item_level = match item.kind {
// Resolved in rustc_privacy when types are available
ast::ItemKind::Impl(..) => return,
// Only exported `macro_rules!` items are public, but they always are
ast::ItemKind::MacroDef(ref macro_def) if macro_def.macro_rules => {
let is_macro_export =
item.attrs.iter().any(|attr| attr.has_name(sym::macro_export));
if is_macro_export { Some(AccessLevel::Public) } else { None }
}
// Foreign modules inherit level from parents.
ast::ItemKind::ForeignMod(..) => self.prev_level,
// Other `pub` items inherit levels from parents.
ast::ItemKind::ExternCrate(..)
| ast::ItemKind::Use(..)
| ast::ItemKind::Static(..)
| ast::ItemKind::Const(..)
| ast::ItemKind::Fn(..)
| ast::ItemKind::Mod(..)
| ast::ItemKind::GlobalAsm(..)
| ast::ItemKind::TyAlias(..)
| ast::ItemKind::Enum(..)
| ast::ItemKind::Struct(..)
| ast::ItemKind::Union(..)
| ast::ItemKind::Trait(..)
| ast::ItemKind::TraitAlias(..)
| ast::ItemKind::MacroDef(..) => {
if item.vis.kind.is_pub() {
self.prev_level
} else {
None
}
}
// Should be unreachable at this stage
ast::ItemKind::MacCall(..) => panic!(
"ast::ItemKind::MacCall encountered, this should not anymore appear at this stage"
),
};
let access_level = self.set_access_level(item.id, inherited_item_level);
// Set access level of nested items.
// If it's a mod, also make the visitor walk all of its items
match item.kind {
ast::ItemKind::Mod(..) => {
if access_level.is_some() {
self.set_exports_access_level(self.r.local_def_id(item.id));
}
let orig_level = std::mem::replace(&mut self.prev_level, access_level);
visit::walk_item(self, item);
self.prev_level = orig_level;
}
ast::ItemKind::ForeignMod(ForeignMod { ref items, .. }) => {
for nested in items {
if nested.vis.kind.is_pub() {
self.set_access_level(nested.id, access_level);
}
}
}
ast::ItemKind::Enum(EnumDef { ref variants }, _) => {
for variant in variants {
let variant_level = self.set_access_level(variant.id, access_level);
if let Some(ctor_id) = variant.data.ctor_id() {
self.set_access_level(ctor_id, access_level);
}
for field in variant.data.fields() {
self.set_access_level(field.id, variant_level);
}
}
}
ast::ItemKind::Struct(ref def, _) | ast::ItemKind::Union(ref def, _) => {
if let Some(ctor_id) = def.ctor_id() {
self.set_access_level(ctor_id, access_level);
}
for field in def.fields() {
if field.vis.kind.is_pub() {
self.set_access_level(field.id, access_level);
}
}
}
ast::ItemKind::Trait(ref trait_kind) => {
for nested in trait_kind.items.iter() {
self.set_access_level(nested.id, access_level);
}
}
ast::ItemKind::ExternCrate(..)
| ast::ItemKind::Use(..)
| ast::ItemKind::Static(..)
| ast::ItemKind::Const(..)
| ast::ItemKind::GlobalAsm(..)
| ast::ItemKind::TyAlias(..)
| ast::ItemKind::TraitAlias(..)
| ast::ItemKind::MacroDef(..)
| ast::ItemKind::Fn(..) => return,
// Unreachable kinds
ast::ItemKind::Impl(..) | ast::ItemKind::MacCall(..) => unreachable!(),
}
}
}