Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly
Sign up
Appearance settings

Commit 67b57f6

Browse files
resolve: Make disambiguators for underscore bindings module-local
1 parent 5a30e43 commit 67b57f6

File tree

4 files changed

+58
-45
lines changed

4 files changed

+58
-45
lines changed

‎compiler/rustc_resolve/src/build_reduced_graph.rs‎

Lines changed: 17 additions & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -49,8 +49,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
4949
ns: Namespace,
5050
binding: NameBinding<'ra>,
5151
) {
52-
let key = self.new_disambiguated_key(ident, ns);
53-
if let Err(old_binding) = self.try_define(parent, key, binding, false) {
52+
if let Err(old_binding) = self.try_define(parent, ident, ns, binding, false) {
5453
self.report_conflict(parent, ident, ns, old_binding, binding);
5554
}
5655
}
@@ -442,16 +441,18 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
442441

443442
self.r.indeterminate_imports.push(import);
444443
match import.kind {
445-
// Don't add unresolved underscore imports to modules
446-
ImportKind::Single { target: Ident { name: kw::Underscore, .. }, .. } => {}
447444
ImportKind::Single { target, type_ns_only, .. } => {
448-
self.r.per_ns(|this, ns| {
449-
if !type_ns_only || ns == TypeNS {
450-
let key = BindingKey::new(target, ns);
451-
let mut resolution = this.resolution(current_module, key).borrow_mut();
452-
resolution.single_imports.insert(import);
453-
}
454-
});
445+
// Don't add underscore imports to `single_imports`
446+
// because they cannot define any usable names.
447+
if target.name != kw::Underscore {
448+
self.r.per_ns(|this, ns| {
449+
if !type_ns_only || ns == TypeNS {
450+
let key = BindingKey::new(target, ns);
451+
let mut resolution = this.resolution(current_module, key).borrow_mut();
452+
resolution.single_imports.insert(import);
453+
}
454+
});
455+
}
455456
}
456457
// We don't add prelude imports to the globs since they only affect lexical scopes,
457458
// which are not relevant to import resolution.
@@ -1408,9 +1409,12 @@ impl<'a, 'ra, 'tcx> Visitor<'a> for BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
14081409
let parent = self.parent_scope.module;
14091410
let expansion = self.parent_scope.expansion;
14101411
self.r.define(parent, ident, ns, self.res(def_id), vis, item.span, expansion);
1411-
} else if !matches!(&item.kind, AssocItemKind::Delegation(deleg) if deleg.from_glob) {
1412+
} else if !matches!(&item.kind, AssocItemKind::Delegation(deleg) if deleg.from_glob)
1413+
&& ident.name != kw::Underscore
1414+
{
1415+
// Don't add underscore names, they cannot be looked up anyway.
14121416
let impl_def_id = self.r.tcx.local_parent(local_def_id);
1413-
let key = BindingKey::new(ident.normalize_to_macros_2_0(), ns);
1417+
let key = BindingKey::new(ident, ns);
14141418
self.r.impl_binding_keys.entry(impl_def_id).or_default().insert(key);
14151419
}
14161420

‎compiler/rustc_resolve/src/imports.rs‎

Lines changed: 25 additions & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -25,7 +25,7 @@ use rustc_span::{Ident, Span, Symbol, kw, sym};
2525
use smallvec::SmallVec;
2626
use tracing::debug;
2727

28-
use crate::Namespace::*;
28+
use crate::Namespace::{self,*};
2929
use crate::diagnostics::{DiagMode, Suggestion, import_candidates};
3030
use crate::errors::{
3131
CannotBeReexportedCratePublic, CannotBeReexportedCratePublicNS, CannotBeReexportedPrivate,
@@ -338,13 +338,20 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
338338
pub(crate) fn try_define(
339339
&mut self,
340340
module: Module<'ra>,
341-
key: BindingKey,
341+
ident: Ident,
342+
ns: Namespace,
342343
binding: NameBinding<'ra>,
343344
warn_ambiguity: bool,
344345
) -> Result<(), NameBinding<'ra>> {
345346
let res = binding.res();
346-
self.check_reserved_macro_name(key.ident, res);
347+
self.check_reserved_macro_name(ident, res);
347348
self.set_binding_parent_module(binding, module);
349+
// Even if underscore names cannot be looked up, we still need to add them to modules,
350+
// because they can be fetched by glob imports from those modules, and bring traits
351+
// into scope both directly and through glob imports.
352+
let key = BindingKey::new_disambiguated(ident, ns, || {
353+
(module.0.0.lazy_resolutions.borrow().len() + 1).try_into().unwrap()
354+
});
348355
self.update_resolution(module, key, warn_ambiguity, |this, resolution| {
349356
if let Some(old_binding) = resolution.best_binding() {
350357
if res == Res::Err && old_binding.res() != Res::Err {
@@ -383,7 +390,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
383390
(old_glob @ true, false) | (old_glob @ false, true) => {
384391
let (glob_binding, non_glob_binding) =
385392
if old_glob { (old_binding, binding) } else { (binding, old_binding) };
386-
if key.ns == MacroNS
393+
if ns == MacroNS
387394
&& non_glob_binding.expansion != LocalExpnId::ROOT
388395
&& glob_binding.res() != non_glob_binding.res()
389396
{
@@ -489,10 +496,10 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
489496
};
490497
if self.is_accessible_from(binding.vis, scope) {
491498
let imported_binding = self.import(binding, *import);
492-
let key = BindingKey { ident, ..key };
493499
let _ = self.try_define(
494500
import.parent_scope.module,
495-
key,
501+
ident,
502+
key.ns,
496503
imported_binding,
497504
warn_ambiguity,
498505
);
@@ -514,11 +521,15 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
514521
let dummy_binding = self.dummy_binding;
515522
let dummy_binding = self.import(dummy_binding, import);
516523
self.per_ns(|this, ns| {
517-
let key = BindingKey::new(target, ns);
518-
let _ = this.try_define(import.parent_scope.module, key, dummy_binding, false);
519-
this.update_resolution(import.parent_scope.module, key, false, |_, resolution| {
520-
resolution.single_imports.swap_remove(&import);
521-
})
524+
let module = import.parent_scope.module;
525+
let _ = this.try_define(module, target, ns, dummy_binding, false);
526+
// Don't remove underscores from `single_imports`, they were never added.
527+
if target.name != kw::Underscore {
528+
let key = BindingKey::new(target, ns);
529+
this.update_resolution(module, key, false, |_, resolution| {
530+
resolution.single_imports.swap_remove(&import);
531+
})
532+
}
522533
});
523534
self.record_use(target, dummy_binding, Used::Other);
524535
} else if import.imported_module.get().is_none() {
@@ -895,7 +906,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
895906
PendingBinding::Ready(Some(imported_binding))
896907
}
897908
Err(Determinacy::Determined) => {
898-
// Don't update the resolution for underscores, because it was never added.
909+
// Don't remove underscores from `single_imports`, they were never added.
899910
if target.name != kw::Underscore {
900911
let key = BindingKey::new(target, ns);
901912
this.update_resolution(parent, key, false, |_, resolution| {
@@ -1510,7 +1521,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
15101521
.is_some_and(|binding| binding.warn_ambiguity_recursive());
15111522
let _ = self.try_define(
15121523
import.parent_scope.module,
1513-
key,
1524+
key.ident,
1525+
key.ns,
15141526
imported_binding,
15151527
warn_ambiguity,
15161528
);

‎compiler/rustc_resolve/src/lib.rs‎

Lines changed: 15 additions & 18 deletions
Original file line numberDiff line numberDiff line change
@@ -532,15 +532,26 @@ struct BindingKey {
532532
/// identifier.
533533
ident: Ident,
534534
ns: Namespace,
535-
/// 0 if ident is not `_`, otherwise a value that's unique to the specific
536-
/// `_` in the expanded AST that introduced this binding.
535+
/// When we add an underscore binding (with ident `_`) to some module, this field has
536+
/// a non-zero value that uniquely identifies this binding in that module.
537+
/// For non-underscore bindings this field is zero.
538+
/// When a key is constructed for name lookup (as opposed to name definition), this field is
539+
/// also zero, even for underscore names, so for underscores the lookup will never succeed.
537540
disambiguator: u32,
538541
}
539542

540543
impl BindingKey {
541544
fn new(ident: Ident, ns: Namespace) -> Self {
542-
let ident = ident.normalize_to_macros_2_0();
543-
BindingKey { ident, ns, disambiguator: 0 }
545+
BindingKey { ident: ident.normalize_to_macros_2_0(), ns, disambiguator: 0 }
546+
}
547+
548+
fn new_disambiguated(
549+
ident: Ident,
550+
ns: Namespace,
551+
disambiguator: impl FnOnce() -> u32,
552+
) -> BindingKey {
553+
let disambiguator = if ident.name == kw::Underscore { disambiguator() } else { 0 };
554+
BindingKey { ident: ident.normalize_to_macros_2_0(), ns, disambiguator }
544555
}
545556
}
546557

@@ -1087,8 +1098,6 @@ pub struct Resolver<'ra, 'tcx> {
10871098
extern_module_map: RefCell<FxIndexMap<DefId, Module<'ra>>>,
10881099
binding_parent_modules: FxHashMap<NameBinding<'ra>, Module<'ra>>,
10891100

1090-
underscore_disambiguator: u32,
1091-
10921101
/// Maps glob imports to the names of items actually imported.
10931102
glob_map: FxIndexMap<LocalDefId, FxIndexSet<Symbol>>,
10941103
glob_error: Option<ErrorGuaranteed>,
@@ -1500,7 +1509,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
15001509
extern_crate_map: Default::default(),
15011510
module_children: Default::default(),
15021511
trait_map: NodeMap::default(),
1503-
underscore_disambiguator: 0,
15041512
empty_module,
15051513
local_module_map,
15061514
extern_module_map: Default::default(),
@@ -1881,17 +1889,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
18811889
import_ids
18821890
}
18831891

1884-
fn new_disambiguated_key(&mut self, ident: Ident, ns: Namespace) -> BindingKey {
1885-
let ident = ident.normalize_to_macros_2_0();
1886-
let disambiguator = if ident.name == kw::Underscore {
1887-
self.underscore_disambiguator += 1;
1888-
self.underscore_disambiguator
1889-
} else {
1890-
0
1891-
};
1892-
BindingKey { ident, ns, disambiguator }
1893-
}
1894-
18951892
fn resolutions(&mut self, module: Module<'ra>) -> &'ra Resolutions<'ra> {
18961893
if module.populate_on_access.get() {
18971894
module.populate_on_access.set(false);

‎compiler/rustc_resolve/src/macros.rs‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -530,7 +530,7 @@ impl<'ra, 'tcx> ResolverExpand for Resolver<'ra, 'tcx> {
530530
target_trait.for_each_child(self, |this, ident, ns, _binding| {
531531
// FIXME: Adjust hygiene for idents from globs, like for glob imports.
532532
if let Some(overriding_keys) = this.impl_binding_keys.get(&impl_def_id)
533-
&& overriding_keys.contains(&BindingKey::new(ident.normalize_to_macros_2_0(), ns))
533+
&& overriding_keys.contains(&BindingKey::new(ident, ns))
534534
{
535535
// The name is overridden, do not produce it from the glob delegation.
536536
} else {

0 commit comments

Comments
(0)

AltStyle によって変換されたページ (->オリジナル) /