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resolve: Populate external modules in more automatic and lazy way
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The modules are now populated implicitly on the first access
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@petrochenkov
petrochenkov committed Aug 16, 2019
1 parent 9dd5c19 commit ea81d8c
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Showing 6 changed files with 73 additions and 71 deletions.
29 changes: 9 additions & 20 deletions src/librustc_resolve/build_reduced_graph.rs
View file
Expand Up @@ -159,19 +159,6 @@ impl<'a> Resolver<'a> {
Some(ext)
}

/// Ensures that the reduced graph rooted at the given external module
/// is built, building it if it is not.
crate fn populate_module_if_necessary(&mut self, module: Module<'a>) {
if module.populated.get() { return }
let def_id = module.def_id().unwrap();
for child in self.cstore.item_children_untracked(def_id, self.session) {
let child = child.map_id(|_| panic!("unexpected id"));
BuildReducedGraphVisitor { parent_scope: ParentScope::module(module), r: self }
.build_reduced_graph_for_external_crate_res(child);
}
module.populated.set(true)
}

crate fn build_reduced_graph(
&mut self, fragment: &AstFragment, parent_scope: ParentScope<'a>
) -> LegacyScope<'a> {
Expand All @@ -186,6 +173,10 @@ struct BuildReducedGraphVisitor<'a, 'b> {
parent_scope: ParentScope<'a>,
}

impl<'a> AsMut<Resolver<'a>> for BuildReducedGraphVisitor<'a, '_> {
fn as_mut(&mut self) -> &mut Resolver<'a> { self.r }
}

impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
let parent_scope = &self.parent_scope;
Expand Down Expand Up @@ -603,8 +594,6 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
self.r.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX })
};

self.r.populate_module_if_necessary(module);

let used = self.process_legacy_macro_imports(item, module);
let binding =
(module, ty::Visibility::Public, sp, expansion).to_name_binding(self.r.arenas);
Expand Down Expand Up @@ -922,6 +911,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
span);
self.r.define(parent, ident, TypeNS, (module, vis, DUMMY_SP, expansion));

module.populate_on_access.set(false);
for child in self.r.cstore.item_children_untracked(def_id, self.r.session) {
let res = child.res.map_id(|_| panic!("unexpected id"));
let ns = if let Res::Def(DefKind::AssocTy, _) = res {
Expand All @@ -935,7 +925,6 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
self.r.has_self.insert(res.def_id());
}
}
module.populated.set(true);
}
Res::Def(DefKind::Struct, def_id) | Res::Def(DefKind::Union, def_id) => {
self.r.define(parent, ident, TypeNS, (res, vis, DUMMY_SP, expansion));
Expand All @@ -952,7 +941,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
}

fn legacy_import_macro(&mut self,
name: Name,
name: ast::Name,
binding: &'a NameBinding<'a>,
span: Span,
allow_shadowing: bool) {
Expand Down Expand Up @@ -1021,9 +1010,9 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
if let Some(span) = import_all {
let directive = macro_use_directive(self, span);
self.r.potentially_unused_imports.push(directive);
module.for_each_child(|ident, ns, binding| if ns == MacroNS {
let imported_binding = self.r.import(binding, directive);
self.legacy_import_macro(ident.name, imported_binding, span, allow_shadowing);
module.for_each_child(self, |this, ident, ns, binding| if ns == MacroNS {
let imported_binding = this.r.import(binding, directive);
this.legacy_import_macro(ident.name, imported_binding, span, allow_shadowing);
});
} else {
for ident in single_imports.iter().cloned() {
Expand Down
27 changes: 13 additions & 14 deletions src/librustc_resolve/diagnostics.rs
View file
Expand Up @@ -73,10 +73,13 @@ crate fn add_typo_suggestion(
false
}

crate fn add_module_candidates(
module: Module<'_>, names: &mut Vec<TypoSuggestion>, filter_fn: &impl Fn(Res) -> bool
crate fn add_module_candidates<'a>(
resolver: &mut Resolver<'a>,
module: Module<'a>,
names: &mut Vec<TypoSuggestion>,
filter_fn: &impl Fn(Res) -> bool,
) {
for (&(ident, _), resolution) in module.resolutions.borrow().iter() {
for (&(ident, _), resolution) in resolver.resolutions(module).borrow().iter() {
if let Some(binding) = resolution.borrow().binding {
let res = binding.res();
if filter_fn(res) {
Expand Down Expand Up @@ -402,10 +405,10 @@ impl<'a> Resolver<'a> {
Scope::CrateRoot => {
let root_ident = Ident::new(kw::PathRoot, ident.span);
let root_module = this.resolve_crate_root(root_ident);
add_module_candidates(root_module, &mut suggestions, filter_fn);
add_module_candidates(this, root_module, &mut suggestions, filter_fn);
}
Scope::Module(module) => {
add_module_candidates(module, &mut suggestions, filter_fn);
add_module_candidates(this, module, &mut suggestions, filter_fn);
}
Scope::MacroUsePrelude => {
suggestions.extend(this.macro_use_prelude.iter().filter_map(|(name, binding)| {
Expand Down Expand Up @@ -453,7 +456,7 @@ impl<'a> Resolver<'a> {
Scope::StdLibPrelude => {
if let Some(prelude) = this.prelude {
let mut tmp_suggestions = Vec::new();
add_module_candidates(prelude, &mut tmp_suggestions, filter_fn);
add_module_candidates(this, prelude, &mut tmp_suggestions, filter_fn);
suggestions.extend(tmp_suggestions.into_iter().filter(|s| {
use_prelude || this.is_builtin_macro(s.res)
}));
Expand Down Expand Up @@ -509,11 +512,9 @@ impl<'a> Resolver<'a> {
while let Some((in_module,
path_segments,
in_module_is_extern)) = worklist.pop() {
self.populate_module_if_necessary(in_module);

// We have to visit module children in deterministic order to avoid
// instabilities in reported imports (#43552).
in_module.for_each_child_stable(|ident, ns, name_binding| {
in_module.for_each_child_stable(self, |this, ident, ns, name_binding| {
// avoid imports entirely
if name_binding.is_import() && !name_binding.is_extern_crate() { return; }
// avoid non-importable candidates as well
Expand Down Expand Up @@ -547,7 +548,7 @@ impl<'a> Resolver<'a> {
// outside crate private modules => no need to check this)
if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
let did = match res {
Res::Def(DefKind::Ctor(..), did) => self.parent(did),
Res::Def(DefKind::Ctor(..), did) => this.parent(did),
_ => res.opt_def_id(),
};
candidates.push(ImportSuggestion { did, path });
Expand Down Expand Up @@ -607,8 +608,6 @@ impl<'a> Resolver<'a> {
krate: crate_id,
index: CRATE_DEF_INDEX,
});
self.populate_module_if_necessary(&crate_root);

suggestions.extend(self.lookup_import_candidates_from_module(
lookup_ident, namespace, crate_root, ident, &filter_fn));
}
Expand Down Expand Up @@ -805,7 +804,7 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
/// at the root of the crate instead of the module where it is defined
/// ```
pub(crate) fn check_for_module_export_macro(
&self,
&mut self,
directive: &'b ImportDirective<'b>,
module: ModuleOrUniformRoot<'b>,
ident: Ident,
Expand All @@ -826,7 +825,7 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
return None;
}

let resolutions = crate_module.resolutions.borrow();
let resolutions = self.r.resolutions(crate_module).borrow();
let resolution = resolutions.get(&(ident, MacroNS))?;
let binding = resolution.borrow().binding()?;
if let Res::Def(DefKind::Macro(MacroKind::Bang), _) = binding.res() {
Expand Down
2 changes: 1 addition & 1 deletion src/librustc_resolve/late.rs
View file
Expand Up @@ -1929,7 +1929,7 @@ impl<'a, 'b> LateResolutionVisitor<'a, '_> {
let mut traits = module.traits.borrow_mut();
if traits.is_none() {
let mut collected_traits = Vec::new();
module.for_each_child(|name, ns, binding| {
module.for_each_child(self.r, |_, name, ns, binding| {
if ns != TypeNS { return }
match binding.res() {
Res::Def(DefKind::Trait, _) |
Expand Down
14 changes: 5 additions & 9 deletions src/librustc_resolve/late/diagnostics.rs
View file
Expand Up @@ -548,7 +548,7 @@ impl<'a> LateResolutionVisitor<'a, '_> {
// Items in scope
if let RibKind::ModuleRibKind(module) = rib.kind {
// Items from this module
add_module_candidates(module, &mut names, &filter_fn);
add_module_candidates(self.r, module, &mut names, &filter_fn);

if let ModuleKind::Block(..) = module.kind {
// We can see through blocks
Expand Down Expand Up @@ -577,7 +577,7 @@ impl<'a> LateResolutionVisitor<'a, '_> {
}));

if let Some(prelude) = self.r.prelude {
add_module_candidates(prelude, &mut names, &filter_fn);
add_module_candidates(self.r, prelude, &mut names, &filter_fn);
}
}
break;
Expand All @@ -599,7 +599,7 @@ impl<'a> LateResolutionVisitor<'a, '_> {
mod_path, Some(TypeNS), false, span, CrateLint::No
) {
if let ModuleOrUniformRoot::Module(module) = module {
add_module_candidates(module, &mut names, &filter_fn);
add_module_candidates(self.r, module, &mut names, &filter_fn);
}
}
}
Expand Down Expand Up @@ -717,9 +717,7 @@ impl<'a> LateResolutionVisitor<'a, '_> {
// abort if the module is already found
if result.is_some() { break; }

self.r.populate_module_if_necessary(in_module);

in_module.for_each_child_stable(|ident, _, name_binding| {
in_module.for_each_child_stable(self.r, |_, ident, _, name_binding| {
// abort if the module is already found or if name_binding is private external
if result.is_some() || !name_binding.vis.is_visible_locally() {
return
Expand Down Expand Up @@ -750,10 +748,8 @@ impl<'a> LateResolutionVisitor<'a, '_> {

fn collect_enum_variants(&mut self, def_id: DefId) -> Option<Vec<Path>> {
self.find_module(def_id).map(|(enum_module, enum_import_suggestion)| {
self.r.populate_module_if_necessary(enum_module);

let mut variants = Vec::new();
enum_module.for_each_child_stable(|ident, _, name_binding| {
enum_module.for_each_child_stable(self.r, |_, ident, _, name_binding| {
if let Res::Def(DefKind::Variant, _) = name_binding.res() {
let mut segms = enum_import_suggestion.path.segments.clone();
segms.push(ast::PathSegment::from_ident(ident));
Expand Down
38 changes: 23 additions & 15 deletions src/librustc_resolve/lib.rs
View file
Expand Up @@ -431,6 +431,8 @@ impl ModuleKind {
}
}

type Resolutions<'a> = RefCell<FxHashMap<(Ident, Namespace), &'a RefCell<NameResolution<'a>>>>;

/// One node in the tree of modules.
pub struct ModuleData<'a> {
parent: Option<Module<'a>>,
Expand All @@ -439,7 +441,11 @@ pub struct ModuleData<'a> {
// The def id of the closest normal module (`mod`) ancestor (including this module).
normal_ancestor_id: DefId,

resolutions: RefCell<FxHashMap<(Ident, Namespace), &'a RefCell<NameResolution<'a>>>>,
// Mapping between names and their (possibly in-progress) resolutions in this module.
// Resolutions in modules from other crates are not populated until accessed.
lazy_resolutions: Resolutions<'a>,
// True if this is a module from other crate that needs to be populated on access.
populate_on_access: Cell<bool>,

// Macro invocations that can expand into items in this module.
unresolved_invocations: RefCell<FxHashSet<ExpnId>>,
Expand All @@ -452,11 +458,6 @@ pub struct ModuleData<'a> {
// Used to memoize the traits in this module for faster searches through all traits in scope.
traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,

// Whether this module is populated. If not populated, any attempt to
// access the children must be preceded with a
// `populate_module_if_necessary` call.
populated: Cell<bool>,

/// Span of the module itself. Used for error reporting.
span: Span,

Expand All @@ -475,30 +476,34 @@ impl<'a> ModuleData<'a> {
parent,
kind,
normal_ancestor_id,
resolutions: Default::default(),
lazy_resolutions: Default::default(),
populate_on_access: Cell::new(!normal_ancestor_id.is_local()),
unresolved_invocations: Default::default(),
no_implicit_prelude: false,
glob_importers: RefCell::new(Vec::new()),
globs: RefCell::new(Vec::new()),
traits: RefCell::new(None),
populated: Cell::new(normal_ancestor_id.is_local()),
span,
expansion,
}
}

fn for_each_child<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
for (&(ident, ns), name_resolution) in self.resolutions.borrow().iter() {
name_resolution.borrow().binding.map(|binding| f(ident, ns, binding));
fn for_each_child<R, F>(&'a self, resolver: &mut R, mut f: F)
where R: AsMut<Resolver<'a>>, F: FnMut(&mut R, Ident, Namespace, &'a NameBinding<'a>)
{
for (&(ident, ns), name_resolution) in resolver.as_mut().resolutions(self).borrow().iter() {
name_resolution.borrow().binding.map(|binding| f(resolver, ident, ns, binding));
}
}

fn for_each_child_stable<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
let resolutions = self.resolutions.borrow();
fn for_each_child_stable<R, F>(&'a self, resolver: &mut R, mut f: F)
where R: AsMut<Resolver<'a>>, F: FnMut(&mut R, Ident, Namespace, &'a NameBinding<'a>)
{
let resolutions = resolver.as_mut().resolutions(self).borrow();
let mut resolutions = resolutions.iter().collect::<Vec<_>>();
resolutions.sort_by_cached_key(|&(&(ident, ns), _)| (ident.as_str(), ns));
for &(&(ident, ns), &resolution) in resolutions.iter() {
resolution.borrow().binding.map(|binding| f(ident, ns, binding));
resolution.borrow().binding.map(|binding| f(resolver, ident, ns, binding));
}
}

Expand Down Expand Up @@ -983,6 +988,10 @@ impl<'a> ResolverArenas<'a> {
}
}

impl<'a> AsMut<Resolver<'a>> for Resolver<'a> {
fn as_mut(&mut self) -> &mut Resolver<'a> { self }
}

impl<'a, 'b> ty::DefIdTree for &'a Resolver<'b> {
fn parent(self, id: DefId) -> Option<DefId> {
match id.krate {
Expand Down Expand Up @@ -2634,7 +2643,6 @@ impl<'a> Resolver<'a> {
return None;
};
let crate_root = self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
self.populate_module_if_necessary(&crate_root);
Some((crate_root, ty::Visibility::Public, DUMMY_SP, ExpnId::root())
.to_name_binding(self.arenas))
}
Expand Down

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