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|
use crate::{ImportKind, NameBindingKind, Resolver};
use rustc_ast::ast;
use rustc_ast::visit;
use rustc_ast::visit::Visitor;
use rustc_ast::Crate;
use rustc_ast::EnumDef;
use rustc_hir::def_id::LocalDefId;
use rustc_hir::def_id::CRATE_DEF_ID;
use rustc_middle::middle::privacy::Level;
use rustc_middle::ty::{DefIdTree, Visibility};
pub struct EffectiveVisibilitiesVisitor<'r, 'a> {
r: &'r mut Resolver<'a>,
changed: bool,
}
impl<'r, 'a> EffectiveVisibilitiesVisitor<'r, 'a> {
/// Fills the `Resolver::effective_visibilities` 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_effective_visibilities<'c>(r: &'r mut Resolver<'a>, krate: &'c Crate) {
let mut visitor = EffectiveVisibilitiesVisitor { r, changed: false };
visitor.update(CRATE_DEF_ID, Visibility::Public, CRATE_DEF_ID, Level::Direct);
visitor.set_bindings_effective_visibilities(CRATE_DEF_ID);
while visitor.changed {
visitor.reset();
visit::walk_crate(&mut visitor, krate);
}
info!("resolve::effective_visibilities: {:#?}", r.effective_visibilities);
}
fn reset(&mut self) {
self.changed = false;
}
/// Update effective visibilities of bindings in the given module,
/// including their whole reexport chains.
fn set_bindings_effective_visibilities(&mut self, module_id: LocalDefId) {
assert!(self.r.module_map.contains_key(&&module_id.to_def_id()));
let module = self.r.get_module(module_id.to_def_id()).unwrap();
let resolutions = self.r.resolutions(module);
for (_, name_resolution) in resolutions.borrow().iter() {
if let Some(mut binding) = name_resolution.borrow().binding() && !binding.is_ambiguity() {
// Set the given effective visibility level to `Level::Direct` and
// sets the rest of the `use` chain to `Level::Reexported` until
// we hit the actual exported item.
// FIXME: tag and is_public() condition should be removed, but assertions occur.
let tag = if binding.is_import() { Level::Reexported } else { Level::Direct };
if binding.vis.is_public() {
let mut prev_parent_id = module_id;
let mut level = Level::Direct;
while let NameBindingKind::Import { binding: nested_binding, import, .. } =
binding.kind
{
let mut update = |node_id| self.update(
self.r.local_def_id(node_id),
binding.vis.expect_local(),
prev_parent_id,
level,
);
// In theory all the import IDs have individual visibilities and effective
// visibilities, but in practice these IDs go straigth to HIR where all
// their few uses assume that their (effective) visibility applies to the
// whole syntactic `use` item. So we update them all to the maximum value
// among the potential individual effective visibilities. Maybe HIR for
// imports shouldn't use three IDs at all.
update(import.id);
if let ImportKind::Single { additional_ids, .. } = import.kind {
update(additional_ids.0);
update(additional_ids.1);
}
level = Level::Reexported;
prev_parent_id = self.r.local_def_id(import.id);
binding = nested_binding;
}
}
if let Some(def_id) = binding.res().opt_def_id().and_then(|id| id.as_local()) {
self.update(def_id, binding.vis.expect_local(), module_id, tag);
}
}
}
}
fn update(
&mut self,
def_id: LocalDefId,
nominal_vis: Visibility,
parent_id: LocalDefId,
tag: Level,
) {
let module_id = self
.r
.get_nearest_non_block_module(def_id.to_def_id())
.nearest_parent_mod()
.expect_local();
if nominal_vis == Visibility::Restricted(module_id)
|| self.r.visibilities[&parent_id] == Visibility::Restricted(module_id)
{
return;
}
let mut effective_visibilities = std::mem::take(&mut self.r.effective_visibilities);
self.changed |= effective_visibilities.update(
def_id,
nominal_vis,
|| Visibility::Restricted(module_id),
parent_id,
tag,
&*self.r,
);
self.r.effective_visibilities = effective_visibilities;
}
}
impl<'r, 'ast> Visitor<'ast> for EffectiveVisibilitiesVisitor<'ast, 'r> {
fn visit_item(&mut self, item: &'ast ast::Item) {
let def_id = self.r.local_def_id(item.id);
// Update effective visibilities of nested items.
// If it's a mod, also make the visitor walk all of its items
match item.kind {
// Resolved in rustc_privacy when types are available
ast::ItemKind::Impl(..) => return,
// Should be unreachable at this stage
ast::ItemKind::MacCall(..) => panic!(
"ast::ItemKind::MacCall encountered, this should not anymore appear at this stage"
),
// Foreign modules inherit level from parents.
ast::ItemKind::ForeignMod(..) => {
let parent_id = self.r.local_parent(def_id);
self.update(def_id, Visibility::Public, parent_id, Level::Direct);
}
// Only exported `macro_rules!` items are public, but they always are
ast::ItemKind::MacroDef(ref macro_def) if macro_def.macro_rules => {
let parent_id = self.r.local_parent(def_id);
let vis = self.r.visibilities[&def_id];
self.update(def_id, vis, parent_id, Level::Direct);
}
ast::ItemKind::Mod(..) => {
self.set_bindings_effective_visibilities(def_id);
visit::walk_item(self, item);
}
ast::ItemKind::Enum(EnumDef { ref variants }, _) => {
self.set_bindings_effective_visibilities(def_id);
for variant in variants {
let variant_def_id = self.r.local_def_id(variant.id);
for field in variant.data.fields() {
let field_def_id = self.r.local_def_id(field.id);
let vis = self.r.visibilities[&field_def_id];
self.update(field_def_id, vis, variant_def_id, Level::Direct);
}
}
}
ast::ItemKind::Struct(ref def, _) | ast::ItemKind::Union(ref def, _) => {
for field in def.fields() {
let field_def_id = self.r.local_def_id(field.id);
let vis = self.r.visibilities[&field_def_id];
self.update(field_def_id, vis, def_id, Level::Direct);
}
}
ast::ItemKind::Trait(..) => {
self.set_bindings_effective_visibilities(def_id);
}
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,
}
}
}
|
