1 // ignore-tidy-filelength
3 //! This crate is responsible for the part of name resolution that doesn't require type checker.
5 //! Module structure of the crate is built here.
6 //! Paths in macros, imports, expressions, types, patterns are resolved here.
7 //! Label and lifetime names are resolved here as well.
9 //! Type-relative name resolution (methods, fields, associated items) happens in `librustc_typeck`.
11 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
12 #![feature(bool_to_option)]
13 #![feature(crate_visibility_modifier)]
15 #![feature(or_patterns)]
16 #![recursion_limit = "256"]
18 pub use rustc_hir::def::{Namespace, PerNS};
22 use rustc_arena::TypedArena;
23 use rustc_ast::ast::{self, FloatTy, IntTy, NodeId, UintTy};
24 use rustc_ast::ast::{Crate, CRATE_NODE_ID};
25 use rustc_ast::ast::{ItemKind, Path};
27 use rustc_ast::node_id::NodeMap;
28 use rustc_ast::unwrap_or;
29 use rustc_ast::visit::{self, Visitor};
30 use rustc_ast_lowering::ResolverAstLowering;
31 use rustc_ast_pretty::pprust;
32 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
33 use rustc_data_structures::ptr_key::PtrKey;
34 use rustc_data_structures::sync::Lrc;
35 use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder};
36 use rustc_expand::base::SyntaxExtension;
37 use rustc_hir::def::Namespace::*;
38 use rustc_hir::def::{self, CtorOf, DefKind, NonMacroAttrKind, PartialRes};
39 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId, CRATE_DEF_INDEX};
40 use rustc_hir::definitions::{DefKey, DefPathData, Definitions};
41 use rustc_hir::PrimTy::{self, Bool, Char, Float, Int, Str, Uint};
42 use rustc_hir::TraitCandidate;
43 use rustc_index::vec::IndexVec;
44 use rustc_metadata::creader::{CStore, CrateLoader};
45 use rustc_middle::hir::exports::ExportMap;
46 use rustc_middle::middle::cstore::{CrateStore, MetadataLoaderDyn};
47 use rustc_middle::span_bug;
48 use rustc_middle::ty::query::Providers;
49 use rustc_middle::ty::{self, DefIdTree, ResolverOutputs};
50 use rustc_session::lint;
51 use rustc_session::lint::{BuiltinLintDiagnostics, LintBuffer};
52 use rustc_session::Session;
53 use rustc_span::hygiene::{ExpnId, ExpnKind, MacroKind, SyntaxContext, Transparency};
54 use rustc_span::source_map::Spanned;
55 use rustc_span::symbol::{kw, sym, Ident, Symbol};
56 use rustc_span::{Span, DUMMY_SP};
59 use std::cell::{Cell, RefCell};
60 use std::collections::BTreeSet;
61 use std::{cmp, fmt, iter, ptr};
63 use diagnostics::{extend_span_to_previous_binding, find_span_of_binding_until_next_binding};
64 use diagnostics::{ImportSuggestion, LabelSuggestion, Suggestion};
65 use imports::{Import, ImportKind, ImportResolver, NameResolution};
66 use late::{HasGenericParams, PathSource, Rib, RibKind::*};
67 use macros::{MacroRulesBinding, MacroRulesScope};
69 type Res = def::Res<NodeId>;
71 mod build_reduced_graph;
84 #[derive(Copy, Clone, PartialEq, Debug)]
85 pub enum Determinacy {
91 fn determined(determined: bool) -> Determinacy {
92 if determined { Determinacy::Determined } else { Determinacy::Undetermined }
96 /// A specific scope in which a name can be looked up.
97 /// This enum is currently used only for early resolution (imports and macros),
98 /// but not for late resolution yet.
99 #[derive(Clone, Copy)]
101 DeriveHelpers(ExpnId),
103 MacroRules(MacroRulesScope<'a>),
115 /// Names from different contexts may want to visit different subsets of all specific scopes
116 /// with different restrictions when looking up the resolution.
117 /// This enum is currently used only for early resolution (imports and macros),
118 /// but not for late resolution yet.
120 /// All scopes with the given namespace.
121 All(Namespace, /*is_import*/ bool),
122 /// Crate root, then extern prelude (used for mixed 2015-2018 mode in macros).
123 AbsolutePath(Namespace),
124 /// All scopes with macro namespace and the given macro kind restriction.
128 /// Everything you need to know about a name's location to resolve it.
129 /// Serves as a starting point for the scope visitor.
130 /// This struct is currently used only for early resolution (imports and macros),
131 /// but not for late resolution yet.
132 #[derive(Clone, Copy, Debug)]
133 pub struct ParentScope<'a> {
136 macro_rules: MacroRulesScope<'a>,
137 derives: &'a [ast::Path],
140 impl<'a> ParentScope<'a> {
141 /// Creates a parent scope with the passed argument used as the module scope component,
142 /// and other scope components set to default empty values.
143 pub fn module(module: Module<'a>) -> ParentScope<'a> {
146 expansion: ExpnId::root(),
147 macro_rules: MacroRulesScope::Empty,
154 struct BindingError {
156 origin: BTreeSet<Span>,
157 target: BTreeSet<Span>,
161 impl PartialOrd for BindingError {
162 fn partial_cmp(&self, other: &BindingError) -> Option<cmp::Ordering> {
163 Some(self.cmp(other))
167 impl PartialEq for BindingError {
168 fn eq(&self, other: &BindingError) -> bool {
169 self.name == other.name
173 impl Ord for BindingError {
174 fn cmp(&self, other: &BindingError) -> cmp::Ordering {
175 self.name.cmp(&other.name)
179 enum ResolutionError<'a> {
180 /// Error E0401: can't use type or const parameters from outer function.
181 GenericParamsFromOuterFunction(Res, HasGenericParams),
182 /// Error E0403: the name is already used for a type or const parameter in this generic
184 NameAlreadyUsedInParameterList(Symbol, Span),
185 /// Error E0407: method is not a member of trait.
186 MethodNotMemberOfTrait(Symbol, &'a str),
187 /// Error E0437: type is not a member of trait.
188 TypeNotMemberOfTrait(Symbol, &'a str),
189 /// Error E0438: const is not a member of trait.
190 ConstNotMemberOfTrait(Symbol, &'a str),
191 /// Error E0408: variable `{}` is not bound in all patterns.
192 VariableNotBoundInPattern(&'a BindingError),
193 /// Error E0409: variable `{}` is bound in inconsistent ways within the same match arm.
194 VariableBoundWithDifferentMode(Symbol, Span),
195 /// Error E0415: identifier is bound more than once in this parameter list.
196 IdentifierBoundMoreThanOnceInParameterList(Symbol),
197 /// Error E0416: identifier is bound more than once in the same pattern.
198 IdentifierBoundMoreThanOnceInSamePattern(Symbol),
199 /// Error E0426: use of undeclared label.
200 UndeclaredLabel { name: Symbol, suggestion: Option<LabelSuggestion> },
201 /// Error E0429: `self` imports are only allowed within a `{ }` list.
202 SelfImportsOnlyAllowedWithin { root: bool, span_with_rename: Span },
203 /// Error E0430: `self` import can only appear once in the list.
204 SelfImportCanOnlyAppearOnceInTheList,
205 /// Error E0431: `self` import can only appear in an import list with a non-empty prefix.
206 SelfImportOnlyInImportListWithNonEmptyPrefix,
207 /// Error E0433: failed to resolve.
208 FailedToResolve { label: String, suggestion: Option<Suggestion> },
209 /// Error E0434: can't capture dynamic environment in a fn item.
210 CannotCaptureDynamicEnvironmentInFnItem,
211 /// Error E0435: attempt to use a non-constant value in a constant.
212 AttemptToUseNonConstantValueInConstant,
213 /// Error E0530: `X` bindings cannot shadow `Y`s.
214 BindingShadowsSomethingUnacceptable(&'static str, Symbol, &'a NameBinding<'a>),
215 /// Error E0128: type parameters with a default cannot use forward-declared identifiers.
216 ForwardDeclaredTyParam, // FIXME(const_generics:defaults)
217 /// ERROR E0770: the type of const parameters must not depend on other generic parameters.
218 ParamInTyOfConstArg(Symbol),
219 /// Error E0735: type parameters with a default cannot use `Self`
220 SelfInTyParamDefault,
221 /// Error E0767: use of unreachable label
222 UnreachableLabel { name: Symbol, definition_span: Span, suggestion: Option<LabelSuggestion> },
225 enum VisResolutionError<'a> {
226 Relative2018(Span, &'a ast::Path),
228 FailedToResolve(Span, String, Option<Suggestion>),
229 ExpectedFound(Span, String, Res),
234 /// A minimal representation of a path segment. We use this in resolve because we synthesize 'path
235 /// segments' which don't have the rest of an AST or HIR `PathSegment`.
236 #[derive(Clone, Copy, Debug)]
240 /// Signals whether this `PathSegment` has generic arguments. Used to avoid providing
241 /// nonsensical suggestions.
242 has_generic_args: bool,
246 fn from_path(path: &Path) -> Vec<Segment> {
247 path.segments.iter().map(|s| s.into()).collect()
250 fn from_ident(ident: Ident) -> Segment {
251 Segment { ident, id: None, has_generic_args: false }
254 fn names_to_string(segments: &[Segment]) -> String {
255 names_to_string(&segments.iter().map(|seg| seg.ident.name).collect::<Vec<_>>())
259 impl<'a> From<&'a ast::PathSegment> for Segment {
260 fn from(seg: &'a ast::PathSegment) -> Segment {
261 Segment { ident: seg.ident, id: Some(seg.id), has_generic_args: seg.args.is_some() }
265 struct UsePlacementFinder {
266 target_module: NodeId,
271 impl UsePlacementFinder {
272 fn check(krate: &Crate, target_module: NodeId) -> (Option<Span>, bool) {
273 let mut finder = UsePlacementFinder { target_module, span: None, found_use: false };
274 visit::walk_crate(&mut finder, krate);
275 (finder.span, finder.found_use)
279 impl<'tcx> Visitor<'tcx> for UsePlacementFinder {
282 module: &'tcx ast::Mod,
284 _: &[ast::Attribute],
287 if self.span.is_some() {
290 if node_id != self.target_module {
291 visit::walk_mod(self, module);
294 // find a use statement
295 for item in &module.items {
297 ItemKind::Use(..) => {
298 // don't suggest placing a use before the prelude
299 // import or other generated ones
300 if !item.span.from_expansion() {
301 self.span = Some(item.span.shrink_to_lo());
302 self.found_use = true;
306 // don't place use before extern crate
307 ItemKind::ExternCrate(_) => {}
308 // but place them before the first other item
310 if self.span.map_or(true, |span| item.span < span) {
311 if !item.span.from_expansion() {
312 // don't insert between attributes and an item
313 if item.attrs.is_empty() {
314 self.span = Some(item.span.shrink_to_lo());
316 // find the first attribute on the item
317 for attr in &item.attrs {
318 if self.span.map_or(true, |span| attr.span < span) {
319 self.span = Some(attr.span.shrink_to_lo());
331 /// An intermediate resolution result.
333 /// This refers to the thing referred by a name. The difference between `Res` and `Item` is that
334 /// items are visible in their whole block, while `Res`es only from the place they are defined
337 enum LexicalScopeBinding<'a> {
338 Item(&'a NameBinding<'a>),
342 impl<'a> LexicalScopeBinding<'a> {
343 fn res(self) -> Res {
345 LexicalScopeBinding::Item(binding) => binding.res(),
346 LexicalScopeBinding::Res(res) => res,
351 #[derive(Copy, Clone, Debug)]
352 enum ModuleOrUniformRoot<'a> {
356 /// Virtual module that denotes resolution in crate root with fallback to extern prelude.
357 CrateRootAndExternPrelude,
359 /// Virtual module that denotes resolution in extern prelude.
360 /// Used for paths starting with `::` on 2018 edition.
363 /// Virtual module that denotes resolution in current scope.
364 /// Used only for resolving single-segment imports. The reason it exists is that import paths
365 /// are always split into two parts, the first of which should be some kind of module.
369 impl ModuleOrUniformRoot<'_> {
370 fn same_def(lhs: Self, rhs: Self) -> bool {
372 (ModuleOrUniformRoot::Module(lhs), ModuleOrUniformRoot::Module(rhs)) => {
373 lhs.def_id() == rhs.def_id()
376 ModuleOrUniformRoot::CrateRootAndExternPrelude,
377 ModuleOrUniformRoot::CrateRootAndExternPrelude,
379 | (ModuleOrUniformRoot::ExternPrelude, ModuleOrUniformRoot::ExternPrelude)
380 | (ModuleOrUniformRoot::CurrentScope, ModuleOrUniformRoot::CurrentScope) => true,
386 #[derive(Clone, Debug)]
387 enum PathResult<'a> {
388 Module(ModuleOrUniformRoot<'a>),
389 NonModule(PartialRes),
394 suggestion: Option<Suggestion>,
395 is_error_from_last_segment: bool,
400 /// An anonymous module; e.g., just a block.
405 /// { // This is an anonymous module
406 /// f(); // This resolves to (2) as we are inside the block.
409 /// f(); // Resolves to (1)
413 /// Any module with a name.
417 /// * A normal module ‒ either `mod from_file;` or `mod from_block { }`.
418 /// * A trait or an enum (it implicitly contains associated types, methods and variant
420 Def(DefKind, DefId, Symbol),
424 /// Get name of the module.
425 pub fn name(&self) -> Option<Symbol> {
427 ModuleKind::Block(..) => None,
428 ModuleKind::Def(.., name) => Some(*name),
433 /// A key that identifies a binding in a given `Module`.
435 /// Multiple bindings in the same module can have the same key (in a valid
436 /// program) if all but one of them come from glob imports.
437 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
439 /// The identifier for the binding, aways the `normalize_to_macros_2_0` version of the
443 /// 0 if ident is not `_`, otherwise a value that's unique to the specific
444 /// `_` in the expanded AST that introduced this binding.
448 type Resolutions<'a> = RefCell<FxIndexMap<BindingKey, &'a RefCell<NameResolution<'a>>>>;
450 /// One node in the tree of modules.
451 pub struct ModuleData<'a> {
452 parent: Option<Module<'a>>,
455 // The def id of the closest normal module (`mod`) ancestor (including this module).
456 normal_ancestor_id: DefId,
458 // Mapping between names and their (possibly in-progress) resolutions in this module.
459 // Resolutions in modules from other crates are not populated until accessed.
460 lazy_resolutions: Resolutions<'a>,
461 // True if this is a module from other crate that needs to be populated on access.
462 populate_on_access: Cell<bool>,
464 // Macro invocations that can expand into items in this module.
465 unexpanded_invocations: RefCell<FxHashSet<ExpnId>>,
467 no_implicit_prelude: bool,
469 glob_importers: RefCell<Vec<&'a Import<'a>>>,
470 globs: RefCell<Vec<&'a Import<'a>>>,
472 // Used to memoize the traits in this module for faster searches through all traits in scope.
473 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
475 /// Span of the module itself. Used for error reporting.
481 type Module<'a> = &'a ModuleData<'a>;
483 impl<'a> ModuleData<'a> {
485 parent: Option<Module<'a>>,
487 normal_ancestor_id: DefId,
495 lazy_resolutions: Default::default(),
496 populate_on_access: Cell::new(!normal_ancestor_id.is_local()),
497 unexpanded_invocations: Default::default(),
498 no_implicit_prelude: false,
499 glob_importers: RefCell::new(Vec::new()),
500 globs: RefCell::new(Vec::new()),
501 traits: RefCell::new(None),
507 fn for_each_child<R, F>(&'a self, resolver: &mut R, mut f: F)
509 R: AsMut<Resolver<'a>>,
510 F: FnMut(&mut R, Ident, Namespace, &'a NameBinding<'a>),
512 for (key, name_resolution) in resolver.as_mut().resolutions(self).borrow().iter() {
513 if let Some(binding) = name_resolution.borrow().binding {
514 f(resolver, key.ident, key.ns, binding);
519 fn res(&self) -> Option<Res> {
521 ModuleKind::Def(kind, def_id, _) => Some(Res::Def(kind, def_id)),
526 fn def_id(&self) -> Option<DefId> {
528 ModuleKind::Def(_, def_id, _) => Some(def_id),
533 // `self` resolves to the first module ancestor that `is_normal`.
534 fn is_normal(&self) -> bool {
536 ModuleKind::Def(DefKind::Mod, _, _) => true,
541 fn is_trait(&self) -> bool {
543 ModuleKind::Def(DefKind::Trait, _, _) => true,
548 fn nearest_item_scope(&'a self) -> Module<'a> {
550 ModuleKind::Def(DefKind::Enum | DefKind::Trait, ..) => {
551 self.parent.expect("enum or trait module without a parent")
557 fn is_ancestor_of(&self, mut other: &Self) -> bool {
558 while !ptr::eq(self, other) {
559 if let Some(parent) = other.parent {
569 impl<'a> fmt::Debug for ModuleData<'a> {
570 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
571 write!(f, "{:?}", self.res())
575 /// Records a possibly-private value, type, or module definition.
576 #[derive(Clone, Debug)]
577 pub struct NameBinding<'a> {
578 kind: NameBindingKind<'a>,
579 ambiguity: Option<(&'a NameBinding<'a>, AmbiguityKind)>,
585 pub trait ToNameBinding<'a> {
586 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
589 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
590 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
595 #[derive(Clone, Debug)]
596 enum NameBindingKind<'a> {
597 Res(Res, /* is_macro_export */ bool),
599 Import { binding: &'a NameBinding<'a>, import: &'a Import<'a>, used: Cell<bool> },
602 impl<'a> NameBindingKind<'a> {
603 /// Is this a name binding of a import?
604 fn is_import(&self) -> bool {
606 NameBindingKind::Import { .. } => true,
612 struct PrivacyError<'a> {
614 binding: &'a NameBinding<'a>,
618 struct UseError<'a> {
619 err: DiagnosticBuilder<'a>,
620 /// Candidates which user could `use` to access the missing type.
621 candidates: Vec<ImportSuggestion>,
622 /// The `DefId` of the module to place the use-statements in.
624 /// Whether the diagnostic should say "instead" (as in `consider importing ... instead`).
626 /// Extra free-form suggestion.
627 suggestion: Option<(Span, &'static str, String, Applicability)>,
630 #[derive(Clone, Copy, PartialEq, Debug)]
635 MacroRulesVsModularized,
643 fn descr(self) -> &'static str {
645 AmbiguityKind::Import => "name vs any other name during import resolution",
646 AmbiguityKind::BuiltinAttr => "built-in attribute vs any other name",
647 AmbiguityKind::DeriveHelper => "derive helper attribute vs any other name",
648 AmbiguityKind::MacroRulesVsModularized => {
649 "`macro_rules` vs non-`macro_rules` from other module"
651 AmbiguityKind::GlobVsOuter => {
652 "glob import vs any other name from outer scope during import/macro resolution"
654 AmbiguityKind::GlobVsGlob => "glob import vs glob import in the same module",
655 AmbiguityKind::GlobVsExpanded => {
656 "glob import vs macro-expanded name in the same \
657 module during import/macro resolution"
659 AmbiguityKind::MoreExpandedVsOuter => {
660 "macro-expanded name vs less macro-expanded name \
661 from outer scope during import/macro resolution"
667 /// Miscellaneous bits of metadata for better ambiguity error reporting.
668 #[derive(Clone, Copy, PartialEq)]
669 enum AmbiguityErrorMisc {
676 struct AmbiguityError<'a> {
679 b1: &'a NameBinding<'a>,
680 b2: &'a NameBinding<'a>,
681 misc1: AmbiguityErrorMisc,
682 misc2: AmbiguityErrorMisc,
685 impl<'a> NameBinding<'a> {
686 fn module(&self) -> Option<Module<'a>> {
688 NameBindingKind::Module(module) => Some(module),
689 NameBindingKind::Import { binding, .. } => binding.module(),
694 fn res(&self) -> Res {
696 NameBindingKind::Res(res, _) => res,
697 NameBindingKind::Module(module) => module.res().unwrap(),
698 NameBindingKind::Import { binding, .. } => binding.res(),
702 fn is_ambiguity(&self) -> bool {
703 self.ambiguity.is_some()
705 NameBindingKind::Import { binding, .. } => binding.is_ambiguity(),
710 fn is_possibly_imported_variant(&self) -> bool {
712 NameBindingKind::Import { binding, .. } => binding.is_possibly_imported_variant(),
713 _ => self.is_variant(),
717 // We sometimes need to treat variants as `pub` for backwards compatibility.
718 fn pseudo_vis(&self) -> ty::Visibility {
719 if self.is_variant() && self.res().def_id().is_local() {
720 ty::Visibility::Public
726 fn is_variant(&self) -> bool {
728 NameBindingKind::Res(
729 Res::Def(DefKind::Variant | DefKind::Ctor(CtorOf::Variant, ..), _),
736 fn is_extern_crate(&self) -> bool {
738 NameBindingKind::Import {
739 import: &Import { kind: ImportKind::ExternCrate { .. }, .. },
742 NameBindingKind::Module(&ModuleData {
743 kind: ModuleKind::Def(DefKind::Mod, def_id, _),
745 }) => def_id.index == CRATE_DEF_INDEX,
750 fn is_import(&self) -> bool {
752 NameBindingKind::Import { .. } => true,
757 fn is_glob_import(&self) -> bool {
759 NameBindingKind::Import { import, .. } => import.is_glob(),
764 fn is_importable(&self) -> bool {
766 Res::Def(DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy, _) => false,
771 fn is_macro_def(&self) -> bool {
773 NameBindingKind::Res(Res::Def(DefKind::Macro(..), _), _) => true,
778 fn macro_kind(&self) -> Option<MacroKind> {
779 self.res().macro_kind()
782 // Suppose that we resolved macro invocation with `invoc_parent_expansion` to binding `binding`
783 // at some expansion round `max(invoc, binding)` when they both emerged from macros.
784 // Then this function returns `true` if `self` may emerge from a macro *after* that
785 // in some later round and screw up our previously found resolution.
786 // See more detailed explanation in
787 // https://github.com/rust-lang/rust/pull/53778#issuecomment-419224049
788 fn may_appear_after(&self, invoc_parent_expansion: ExpnId, binding: &NameBinding<'_>) -> bool {
789 // self > max(invoc, binding) => !(self <= invoc || self <= binding)
790 // Expansions are partially ordered, so "may appear after" is an inversion of
791 // "certainly appears before or simultaneously" and includes unordered cases.
792 let self_parent_expansion = self.expansion;
793 let other_parent_expansion = binding.expansion;
794 let certainly_before_other_or_simultaneously =
795 other_parent_expansion.is_descendant_of(self_parent_expansion);
796 let certainly_before_invoc_or_simultaneously =
797 invoc_parent_expansion.is_descendant_of(self_parent_expansion);
798 !(certainly_before_other_or_simultaneously || certainly_before_invoc_or_simultaneously)
802 /// Interns the names of the primitive types.
804 /// All other types are defined somewhere and possibly imported, but the primitive ones need
805 /// special handling, since they have no place of origin.
806 struct PrimitiveTypeTable {
807 primitive_types: FxHashMap<Symbol, PrimTy>,
810 impl PrimitiveTypeTable {
811 fn new() -> PrimitiveTypeTable {
812 let mut table = FxHashMap::default();
814 table.insert(sym::bool, Bool);
815 table.insert(sym::char, Char);
816 table.insert(sym::f32, Float(FloatTy::F32));
817 table.insert(sym::f64, Float(FloatTy::F64));
818 table.insert(sym::isize, Int(IntTy::Isize));
819 table.insert(sym::i8, Int(IntTy::I8));
820 table.insert(sym::i16, Int(IntTy::I16));
821 table.insert(sym::i32, Int(IntTy::I32));
822 table.insert(sym::i64, Int(IntTy::I64));
823 table.insert(sym::i128, Int(IntTy::I128));
824 table.insert(sym::str, Str);
825 table.insert(sym::usize, Uint(UintTy::Usize));
826 table.insert(sym::u8, Uint(UintTy::U8));
827 table.insert(sym::u16, Uint(UintTy::U16));
828 table.insert(sym::u32, Uint(UintTy::U32));
829 table.insert(sym::u64, Uint(UintTy::U64));
830 table.insert(sym::u128, Uint(UintTy::U128));
831 Self { primitive_types: table }
835 #[derive(Debug, Default, Clone)]
836 pub struct ExternPreludeEntry<'a> {
837 extern_crate_item: Option<&'a NameBinding<'a>>,
838 pub introduced_by_item: bool,
841 /// The main resolver class.
843 /// This is the visitor that walks the whole crate.
844 pub struct Resolver<'a> {
845 session: &'a Session,
847 definitions: Definitions,
849 graph_root: Module<'a>,
851 prelude: Option<Module<'a>>,
852 extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'a>>,
854 /// N.B., this is used only for better diagnostics, not name resolution itself.
855 has_self: FxHashSet<DefId>,
857 /// Names of fields of an item `DefId` accessible with dot syntax.
858 /// Used for hints during error reporting.
859 field_names: FxHashMap<DefId, Vec<Spanned<Symbol>>>,
861 /// All imports known to succeed or fail.
862 determined_imports: Vec<&'a Import<'a>>,
864 /// All non-determined imports.
865 indeterminate_imports: Vec<&'a Import<'a>>,
867 /// FIXME: Refactor things so that these fields are passed through arguments and not resolver.
868 /// We are resolving a last import segment during import validation.
869 last_import_segment: bool,
870 /// This binding should be ignored during in-module resolution, so that we don't get
871 /// "self-confirming" import resolutions during import validation.
872 unusable_binding: Option<&'a NameBinding<'a>>,
874 /// The idents for the primitive types.
875 primitive_type_table: PrimitiveTypeTable,
877 /// Resolutions for nodes that have a single resolution.
878 partial_res_map: NodeMap<PartialRes>,
879 /// Resolutions for import nodes, which have multiple resolutions in different namespaces.
880 import_res_map: NodeMap<PerNS<Option<Res>>>,
881 /// Resolutions for labels (node IDs of their corresponding blocks or loops).
882 label_res_map: NodeMap<NodeId>,
884 /// `CrateNum` resolutions of `extern crate` items.
885 extern_crate_map: FxHashMap<LocalDefId, CrateNum>,
886 export_map: ExportMap<LocalDefId>,
887 trait_map: NodeMap<Vec<TraitCandidate>>,
889 /// A map from nodes to anonymous modules.
890 /// Anonymous modules are pseudo-modules that are implicitly created around items
891 /// contained within blocks.
893 /// For example, if we have this:
901 /// There will be an anonymous module created around `g` with the ID of the
902 /// entry block for `f`.
903 block_map: NodeMap<Module<'a>>,
904 /// A fake module that contains no definition and no prelude. Used so that
905 /// some AST passes can generate identifiers that only resolve to local or
907 empty_module: Module<'a>,
908 module_map: FxHashMap<LocalDefId, Module<'a>>,
909 extern_module_map: FxHashMap<DefId, Module<'a>>,
910 binding_parent_modules: FxHashMap<PtrKey<'a, NameBinding<'a>>, Module<'a>>,
911 underscore_disambiguator: u32,
913 /// Maps glob imports to the names of items actually imported.
914 glob_map: FxHashMap<LocalDefId, FxHashSet<Symbol>>,
916 used_imports: FxHashSet<(NodeId, Namespace)>,
917 maybe_unused_trait_imports: FxHashSet<LocalDefId>,
918 maybe_unused_extern_crates: Vec<(LocalDefId, Span)>,
920 /// Privacy errors are delayed until the end in order to deduplicate them.
921 privacy_errors: Vec<PrivacyError<'a>>,
922 /// Ambiguity errors are delayed for deduplication.
923 ambiguity_errors: Vec<AmbiguityError<'a>>,
924 /// `use` injections are delayed for better placement and deduplication.
925 use_injections: Vec<UseError<'a>>,
926 /// Crate-local macro expanded `macro_export` referred to by a module-relative path.
927 macro_expanded_macro_export_errors: BTreeSet<(Span, Span)>,
929 arenas: &'a ResolverArenas<'a>,
930 dummy_binding: &'a NameBinding<'a>,
932 crate_loader: CrateLoader<'a>,
933 macro_names: FxHashSet<Ident>,
934 builtin_macros: FxHashMap<Symbol, SyntaxExtension>,
935 registered_attrs: FxHashSet<Ident>,
936 registered_tools: FxHashSet<Ident>,
937 macro_use_prelude: FxHashMap<Symbol, &'a NameBinding<'a>>,
938 all_macros: FxHashMap<Symbol, Res>,
939 macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>,
940 dummy_ext_bang: Lrc<SyntaxExtension>,
941 dummy_ext_derive: Lrc<SyntaxExtension>,
942 non_macro_attrs: [Lrc<SyntaxExtension>; 2],
943 local_macro_def_scopes: FxHashMap<LocalDefId, Module<'a>>,
944 ast_transform_scopes: FxHashMap<ExpnId, Module<'a>>,
945 unused_macros: FxHashMap<LocalDefId, (NodeId, Span)>,
946 proc_macro_stubs: FxHashSet<LocalDefId>,
947 /// Traces collected during macro resolution and validated when it's complete.
948 single_segment_macro_resolutions:
949 Vec<(Ident, MacroKind, ParentScope<'a>, Option<&'a NameBinding<'a>>)>,
950 multi_segment_macro_resolutions:
951 Vec<(Vec<Segment>, Span, MacroKind, ParentScope<'a>, Option<Res>)>,
952 builtin_attrs: Vec<(Ident, ParentScope<'a>)>,
953 /// `derive(Copy)` marks items they are applied to so they are treated specially later.
954 /// Derive macros cannot modify the item themselves and have to store the markers in the global
955 /// context, so they attach the markers to derive container IDs using this resolver table.
956 containers_deriving_copy: FxHashSet<ExpnId>,
957 /// Parent scopes in which the macros were invoked.
958 /// FIXME: `derives` are missing in these parent scopes and need to be taken from elsewhere.
959 invocation_parent_scopes: FxHashMap<ExpnId, ParentScope<'a>>,
960 /// `macro_rules` scopes *produced* by expanding the macro invocations,
961 /// include all the `macro_rules` items and other invocations generated by them.
962 output_macro_rules_scopes: FxHashMap<ExpnId, MacroRulesScope<'a>>,
963 /// Helper attributes that are in scope for the given expansion.
964 helper_attrs: FxHashMap<ExpnId, Vec<Ident>>,
966 /// Avoid duplicated errors for "name already defined".
967 name_already_seen: FxHashMap<Symbol, Span>,
969 potentially_unused_imports: Vec<&'a Import<'a>>,
971 /// Table for mapping struct IDs into struct constructor IDs,
972 /// it's not used during normal resolution, only for better error reporting.
973 struct_constructors: DefIdMap<(Res, ty::Visibility)>,
975 /// Features enabled for this crate.
976 active_features: FxHashSet<Symbol>,
978 /// Stores enum visibilities to properly build a reduced graph
979 /// when visiting the correspondent variants.
980 variant_vis: DefIdMap<ty::Visibility>,
982 lint_buffer: LintBuffer,
984 next_node_id: NodeId,
986 def_id_to_span: IndexVec<LocalDefId, Span>,
988 node_id_to_def_id: FxHashMap<ast::NodeId, LocalDefId>,
989 def_id_to_node_id: IndexVec<LocalDefId, ast::NodeId>,
991 /// Indices of unnamed struct or variant fields with unresolved attributes.
992 placeholder_field_indices: FxHashMap<NodeId, usize>,
993 /// When collecting definitions from an AST fragment produced by a macro invocation `ExpnId`
994 /// we know what parent node that fragment should be attached to thanks to this table.
995 invocation_parents: FxHashMap<ExpnId, LocalDefId>,
997 next_disambiguator: FxHashMap<(LocalDefId, DefPathData), u32>,
1000 /// Nothing really interesting here; it just provides memory for the rest of the crate.
1002 pub struct ResolverArenas<'a> {
1003 modules: TypedArena<ModuleData<'a>>,
1004 local_modules: RefCell<Vec<Module<'a>>>,
1005 name_bindings: TypedArena<NameBinding<'a>>,
1006 imports: TypedArena<Import<'a>>,
1007 name_resolutions: TypedArena<RefCell<NameResolution<'a>>>,
1008 macro_rules_bindings: TypedArena<MacroRulesBinding<'a>>,
1009 ast_paths: TypedArena<ast::Path>,
1012 impl<'a> ResolverArenas<'a> {
1013 fn alloc_module(&'a self, module: ModuleData<'a>) -> Module<'a> {
1014 let module = self.modules.alloc(module);
1015 if module.def_id().map(|def_id| def_id.is_local()).unwrap_or(true) {
1016 self.local_modules.borrow_mut().push(module);
1020 fn local_modules(&'a self) -> std::cell::Ref<'a, Vec<Module<'a>>> {
1021 self.local_modules.borrow()
1023 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1024 self.name_bindings.alloc(name_binding)
1026 fn alloc_import(&'a self, import: Import<'a>) -> &'a Import<'_> {
1027 self.imports.alloc(import)
1029 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1030 self.name_resolutions.alloc(Default::default())
1032 fn alloc_macro_rules_binding(
1034 binding: MacroRulesBinding<'a>,
1035 ) -> &'a MacroRulesBinding<'a> {
1036 self.macro_rules_bindings.alloc(binding)
1038 fn alloc_ast_paths(&'a self, paths: &[ast::Path]) -> &'a [ast::Path] {
1039 self.ast_paths.alloc_from_iter(paths.iter().cloned())
1043 impl<'a> AsMut<Resolver<'a>> for Resolver<'a> {
1044 fn as_mut(&mut self) -> &mut Resolver<'a> {
1049 impl<'a, 'b> DefIdTree for &'a Resolver<'b> {
1050 fn parent(self, id: DefId) -> Option<DefId> {
1051 match id.as_local() {
1052 Some(id) => self.definitions.def_key(id).parent,
1053 None => self.cstore().def_key(id).parent,
1055 .map(|index| DefId { index, ..id })
1059 /// This interface is used through the AST→HIR step, to embed full paths into the HIR. After that
1060 /// the resolver is no longer needed as all the relevant information is inline.
1061 impl ResolverAstLowering for Resolver<'_> {
1062 fn def_key(&mut self, id: DefId) -> DefKey {
1063 if let Some(id) = id.as_local() {
1064 self.definitions().def_key(id)
1066 self.cstore().def_key(id)
1070 fn item_generics_num_lifetimes(&self, def_id: DefId, sess: &Session) -> usize {
1071 self.cstore().item_generics_num_lifetimes(def_id, sess)
1074 fn resolve_str_path(
1077 crate_root: Option<Symbol>,
1078 components: &[Symbol],
1080 ) -> (ast::Path, Res) {
1081 let root = if crate_root.is_some() { kw::PathRoot } else { kw::Crate };
1082 let segments = iter::once(Ident::with_dummy_span(root))
1086 .chain(components.iter().cloned())
1087 .map(Ident::with_dummy_span),
1089 .map(|i| self.new_ast_path_segment(i))
1090 .collect::<Vec<_>>();
1092 let path = ast::Path { span, segments };
1094 let parent_scope = &ParentScope::module(self.graph_root);
1095 let res = match self.resolve_ast_path(&path, ns, parent_scope) {
1097 Err((span, error)) => {
1098 self.report_error(span, error);
1105 fn get_partial_res(&mut self, id: NodeId) -> Option<PartialRes> {
1106 self.partial_res_map.get(&id).cloned()
1109 fn get_import_res(&mut self, id: NodeId) -> PerNS<Option<Res>> {
1110 self.import_res_map.get(&id).cloned().unwrap_or_default()
1113 fn get_label_res(&mut self, id: NodeId) -> Option<NodeId> {
1114 self.label_res_map.get(&id).cloned()
1117 fn definitions(&mut self) -> &mut Definitions {
1118 &mut self.definitions
1121 fn lint_buffer(&mut self) -> &mut LintBuffer {
1122 &mut self.lint_buffer
1125 fn next_node_id(&mut self) -> NodeId {
1129 fn trait_map(&self) -> &NodeMap<Vec<TraitCandidate>> {
1133 fn opt_local_def_id(&self, node: NodeId) -> Option<LocalDefId> {
1134 self.node_id_to_def_id.get(&node).copied()
1137 fn local_def_id(&self, node: NodeId) -> LocalDefId {
1138 self.opt_local_def_id(node).unwrap_or_else(|| panic!("no entry for node id: `{:?}`", node))
1141 /// Adds a definition with a parent definition.
1145 node_id: ast::NodeId,
1151 !self.node_id_to_def_id.contains_key(&node_id),
1152 "adding a def'n for node-id {:?} and data {:?} but a previous def'n exists: {:?}",
1155 self.definitions.def_key(self.node_id_to_def_id[&node_id]),
1158 // Find the next free disambiguator for this key.
1159 let next_disambiguator = &mut self.next_disambiguator;
1160 let next_disambiguator = |parent, data| {
1161 let next_disamb = next_disambiguator.entry((parent, data)).or_insert(0);
1162 let disambiguator = *next_disamb;
1163 *next_disamb = next_disamb.checked_add(1).expect("disambiguator overflow");
1167 let def_id = self.definitions.create_def(parent, data, expn_id, next_disambiguator);
1169 assert_eq!(self.def_id_to_span.push(span), def_id);
1171 // Some things for which we allocate `LocalDefId`s don't correspond to
1172 // anything in the AST, so they don't have a `NodeId`. For these cases
1173 // we don't need a mapping from `NodeId` to `LocalDefId`.
1174 if node_id != ast::DUMMY_NODE_ID {
1175 debug!("create_def: def_id_to_node_id[{:?}] <-> {:?}", def_id, node_id);
1176 self.node_id_to_def_id.insert(node_id, def_id);
1178 assert_eq!(self.def_id_to_node_id.push(node_id), def_id);
1184 impl<'a> Resolver<'a> {
1186 session: &'a Session,
1189 metadata_loader: &'a MetadataLoaderDyn,
1190 arenas: &'a ResolverArenas<'a>,
1192 let root_def_id = DefId::local(CRATE_DEF_INDEX);
1193 let root_module_kind = ModuleKind::Def(DefKind::Mod, root_def_id, kw::Invalid);
1194 let graph_root = arenas.alloc_module(ModuleData {
1195 no_implicit_prelude: attr::contains_name(&krate.attrs, sym::no_implicit_prelude),
1196 ..ModuleData::new(None, root_module_kind, root_def_id, ExpnId::root(), krate.span)
1198 let empty_module_kind = ModuleKind::Def(DefKind::Mod, root_def_id, kw::Invalid);
1199 let empty_module = arenas.alloc_module(ModuleData {
1200 no_implicit_prelude: true,
1209 let mut module_map = FxHashMap::default();
1210 module_map.insert(LocalDefId { local_def_index: CRATE_DEF_INDEX }, graph_root);
1212 let definitions = Definitions::new(crate_name, session.local_crate_disambiguator());
1213 let root = definitions.get_root_def();
1215 let mut def_id_to_span = IndexVec::default();
1216 assert_eq!(def_id_to_span.push(rustc_span::DUMMY_SP), root);
1217 let mut def_id_to_node_id = IndexVec::default();
1218 assert_eq!(def_id_to_node_id.push(CRATE_NODE_ID), root);
1219 let mut node_id_to_def_id = FxHashMap::default();
1220 node_id_to_def_id.insert(CRATE_NODE_ID, root);
1222 let mut invocation_parents = FxHashMap::default();
1223 invocation_parents.insert(ExpnId::root(), root);
1225 let mut extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'_>> = session
1229 .filter(|(_, entry)| entry.add_prelude)
1230 .map(|(name, _)| (Ident::from_str(name), Default::default()))
1233 if !attr::contains_name(&krate.attrs, sym::no_core) {
1234 extern_prelude.insert(Ident::with_dummy_span(sym::core), Default::default());
1235 if !attr::contains_name(&krate.attrs, sym::no_std) {
1236 extern_prelude.insert(Ident::with_dummy_span(sym::std), Default::default());
1237 if session.rust_2018() {
1238 extern_prelude.insert(Ident::with_dummy_span(sym::meta), Default::default());
1243 let (registered_attrs, registered_tools) =
1244 macros::registered_attrs_and_tools(session, &krate.attrs);
1246 let mut invocation_parent_scopes = FxHashMap::default();
1247 invocation_parent_scopes.insert(ExpnId::root(), ParentScope::module(graph_root));
1249 let features = session.features_untracked();
1250 let non_macro_attr =
1251 |mark_used| Lrc::new(SyntaxExtension::non_macro_attr(mark_used, session.edition()));
1258 // The outermost module has def ID 0; this is not reflected in the
1264 has_self: FxHashSet::default(),
1265 field_names: FxHashMap::default(),
1267 determined_imports: Vec::new(),
1268 indeterminate_imports: Vec::new(),
1270 last_import_segment: false,
1271 unusable_binding: None,
1273 primitive_type_table: PrimitiveTypeTable::new(),
1275 partial_res_map: Default::default(),
1276 import_res_map: Default::default(),
1277 label_res_map: Default::default(),
1278 extern_crate_map: Default::default(),
1279 export_map: FxHashMap::default(),
1280 trait_map: Default::default(),
1281 underscore_disambiguator: 0,
1284 block_map: Default::default(),
1285 extern_module_map: FxHashMap::default(),
1286 binding_parent_modules: FxHashMap::default(),
1287 ast_transform_scopes: FxHashMap::default(),
1289 glob_map: Default::default(),
1291 used_imports: FxHashSet::default(),
1292 maybe_unused_trait_imports: Default::default(),
1293 maybe_unused_extern_crates: Vec::new(),
1295 privacy_errors: Vec::new(),
1296 ambiguity_errors: Vec::new(),
1297 use_injections: Vec::new(),
1298 macro_expanded_macro_export_errors: BTreeSet::new(),
1301 dummy_binding: arenas.alloc_name_binding(NameBinding {
1302 kind: NameBindingKind::Res(Res::Err, false),
1304 expansion: ExpnId::root(),
1306 vis: ty::Visibility::Public,
1309 crate_loader: CrateLoader::new(session, metadata_loader, crate_name),
1310 macro_names: FxHashSet::default(),
1311 builtin_macros: Default::default(),
1314 macro_use_prelude: FxHashMap::default(),
1315 all_macros: FxHashMap::default(),
1316 macro_map: FxHashMap::default(),
1317 dummy_ext_bang: Lrc::new(SyntaxExtension::dummy_bang(session.edition())),
1318 dummy_ext_derive: Lrc::new(SyntaxExtension::dummy_derive(session.edition())),
1319 non_macro_attrs: [non_macro_attr(false), non_macro_attr(true)],
1320 invocation_parent_scopes,
1321 output_macro_rules_scopes: Default::default(),
1322 helper_attrs: Default::default(),
1323 local_macro_def_scopes: FxHashMap::default(),
1324 name_already_seen: FxHashMap::default(),
1325 potentially_unused_imports: Vec::new(),
1326 struct_constructors: Default::default(),
1327 unused_macros: Default::default(),
1328 proc_macro_stubs: Default::default(),
1329 single_segment_macro_resolutions: Default::default(),
1330 multi_segment_macro_resolutions: Default::default(),
1331 builtin_attrs: Default::default(),
1332 containers_deriving_copy: Default::default(),
1333 active_features: features
1334 .declared_lib_features
1336 .map(|(feat, ..)| *feat)
1337 .chain(features.declared_lang_features.iter().map(|(feat, ..)| *feat))
1339 variant_vis: Default::default(),
1340 lint_buffer: LintBuffer::default(),
1341 next_node_id: NodeId::from_u32(1),
1345 placeholder_field_indices: Default::default(),
1347 next_disambiguator: Default::default(),
1351 pub fn next_node_id(&mut self) -> NodeId {
1356 .expect("input too large; ran out of NodeIds");
1357 self.next_node_id = ast::NodeId::from_usize(next);
1361 pub fn lint_buffer(&mut self) -> &mut LintBuffer {
1362 &mut self.lint_buffer
1365 pub fn arenas() -> ResolverArenas<'a> {
1369 pub fn into_outputs(self) -> ResolverOutputs {
1370 let definitions = self.definitions;
1371 let extern_crate_map = self.extern_crate_map;
1372 let export_map = self.export_map;
1373 let maybe_unused_trait_imports = self.maybe_unused_trait_imports;
1374 let maybe_unused_extern_crates = self.maybe_unused_extern_crates;
1375 let glob_map = self.glob_map;
1377 definitions: definitions,
1378 cstore: Box::new(self.crate_loader.into_cstore()),
1382 maybe_unused_trait_imports,
1383 maybe_unused_extern_crates,
1384 extern_prelude: self
1387 .map(|(ident, entry)| (ident.name, entry.introduced_by_item))
1392 pub fn clone_outputs(&self) -> ResolverOutputs {
1394 definitions: self.definitions.clone(),
1395 cstore: Box::new(self.cstore().clone()),
1396 extern_crate_map: self.extern_crate_map.clone(),
1397 export_map: self.export_map.clone(),
1398 glob_map: self.glob_map.clone(),
1399 maybe_unused_trait_imports: self.maybe_unused_trait_imports.clone(),
1400 maybe_unused_extern_crates: self.maybe_unused_extern_crates.clone(),
1401 extern_prelude: self
1404 .map(|(ident, entry)| (ident.name, entry.introduced_by_item))
1409 pub fn cstore(&self) -> &CStore {
1410 self.crate_loader.cstore()
1413 fn non_macro_attr(&self, mark_used: bool) -> Lrc<SyntaxExtension> {
1414 self.non_macro_attrs[mark_used as usize].clone()
1417 fn dummy_ext(&self, macro_kind: MacroKind) -> Lrc<SyntaxExtension> {
1419 MacroKind::Bang => self.dummy_ext_bang.clone(),
1420 MacroKind::Derive => self.dummy_ext_derive.clone(),
1421 MacroKind::Attr => self.non_macro_attr(true),
1425 /// Runs the function on each namespace.
1426 fn per_ns<F: FnMut(&mut Self, Namespace)>(&mut self, mut f: F) {
1432 fn is_builtin_macro(&mut self, res: Res) -> bool {
1433 self.get_macro(res).map_or(false, |ext| ext.is_builtin)
1436 fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
1438 match ctxt.outer_expn().expn_data().macro_def_id {
1439 Some(def_id) => return def_id,
1440 None => ctxt.remove_mark(),
1445 /// Entry point to crate resolution.
1446 pub fn resolve_crate(&mut self, krate: &Crate) {
1447 let _prof_timer = self.session.prof.generic_activity("resolve_crate");
1449 ImportResolver { r: self }.finalize_imports();
1450 self.finalize_macro_resolutions();
1452 self.late_resolve_crate(krate);
1454 self.check_unused(krate);
1455 self.report_errors(krate);
1456 self.crate_loader.postprocess(krate);
1463 normal_ancestor_id: DefId,
1467 let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expn_id, span);
1468 self.arenas.alloc_module(module)
1471 fn new_key(&mut self, ident: Ident, ns: Namespace) -> BindingKey {
1472 let ident = ident.normalize_to_macros_2_0();
1473 let disambiguator = if ident.name == kw::Underscore {
1474 self.underscore_disambiguator += 1;
1475 self.underscore_disambiguator
1479 BindingKey { ident, ns, disambiguator }
1482 fn resolutions(&mut self, module: Module<'a>) -> &'a Resolutions<'a> {
1483 if module.populate_on_access.get() {
1484 module.populate_on_access.set(false);
1485 self.build_reduced_graph_external(module);
1487 &module.lazy_resolutions
1494 ) -> &'a RefCell<NameResolution<'a>> {
1496 .resolutions(module)
1499 .or_insert_with(|| self.arenas.alloc_name_resolution())
1506 used_binding: &'a NameBinding<'a>,
1507 is_lexical_scope: bool,
1509 if let Some((b2, kind)) = used_binding.ambiguity {
1510 self.ambiguity_errors.push(AmbiguityError {
1515 misc1: AmbiguityErrorMisc::None,
1516 misc2: AmbiguityErrorMisc::None,
1519 if let NameBindingKind::Import { import, binding, ref used } = used_binding.kind {
1520 // Avoid marking `extern crate` items that refer to a name from extern prelude,
1521 // but not introduce it, as used if they are accessed from lexical scope.
1522 if is_lexical_scope {
1523 if let Some(entry) = self.extern_prelude.get(&ident.normalize_to_macros_2_0()) {
1524 if let Some(crate_item) = entry.extern_crate_item {
1525 if ptr::eq(used_binding, crate_item) && !entry.introduced_by_item {
1532 import.used.set(true);
1533 self.used_imports.insert((import.id, ns));
1534 self.add_to_glob_map(&import, ident);
1535 self.record_use(ident, ns, binding, false);
1540 fn add_to_glob_map(&mut self, import: &Import<'_>, ident: Ident) {
1541 if import.is_glob() {
1542 let def_id = self.local_def_id(import.id);
1543 self.glob_map.entry(def_id).or_default().insert(ident.name);
1547 /// A generic scope visitor.
1548 /// Visits scopes in order to resolve some identifier in them or perform other actions.
1549 /// If the callback returns `Some` result, we stop visiting scopes and return it.
1552 scope_set: ScopeSet,
1553 parent_scope: &ParentScope<'a>,
1555 mut visitor: impl FnMut(&mut Self, Scope<'a>, /*use_prelude*/ bool, Ident) -> Option<T>,
1557 // General principles:
1558 // 1. Not controlled (user-defined) names should have higher priority than controlled names
1559 // built into the language or standard library. This way we can add new names into the
1560 // language or standard library without breaking user code.
1561 // 2. "Closed set" below means new names cannot appear after the current resolution attempt.
1562 // Places to search (in order of decreasing priority):
1564 // 1. FIXME: Ribs (type parameters), there's no necessary infrastructure yet
1565 // (open set, not controlled).
1566 // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
1567 // (open, not controlled).
1568 // 3. Extern prelude (open, the open part is from macro expansions, not controlled).
1569 // 4. Tool modules (closed, controlled right now, but not in the future).
1570 // 5. Standard library prelude (de-facto closed, controlled).
1571 // 6. Language prelude (closed, controlled).
1573 // 1. FIXME: Ribs (local variables), there's no necessary infrastructure yet
1574 // (open set, not controlled).
1575 // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
1576 // (open, not controlled).
1577 // 3. Standard library prelude (de-facto closed, controlled).
1579 // 1-3. Derive helpers (open, not controlled). All ambiguities with other names
1580 // are currently reported as errors. They should be higher in priority than preludes
1581 // and probably even names in modules according to the "general principles" above. They
1582 // also should be subject to restricted shadowing because are effectively produced by
1583 // derives (you need to resolve the derive first to add helpers into scope), but they
1584 // should be available before the derive is expanded for compatibility.
1585 // It's mess in general, so we are being conservative for now.
1586 // 1-3. `macro_rules` (open, not controlled), loop through `macro_rules` scopes. Have higher
1587 // priority than prelude macros, but create ambiguities with macros in modules.
1588 // 1-3. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
1589 // (open, not controlled). Have higher priority than prelude macros, but create
1590 // ambiguities with `macro_rules`.
1591 // 4. `macro_use` prelude (open, the open part is from macro expansions, not controlled).
1592 // 4a. User-defined prelude from macro-use
1593 // (open, the open part is from macro expansions, not controlled).
1594 // 4b. "Standard library prelude" part implemented through `macro-use` (closed, controlled).
1595 // 4c. Standard library prelude (de-facto closed, controlled).
1596 // 6. Language prelude: builtin attributes (closed, controlled).
1598 let rust_2015 = ident.span.rust_2015();
1599 let (ns, macro_kind, is_absolute_path) = match scope_set {
1600 ScopeSet::All(ns, _) => (ns, None, false),
1601 ScopeSet::AbsolutePath(ns) => (ns, None, true),
1602 ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind), false),
1604 // Jump out of trait or enum modules, they do not act as scopes.
1605 let module = parent_scope.module.nearest_item_scope();
1606 let mut scope = match ns {
1607 _ if is_absolute_path => Scope::CrateRoot,
1608 TypeNS | ValueNS => Scope::Module(module),
1609 MacroNS => Scope::DeriveHelpers(parent_scope.expansion),
1611 let mut ident = ident.normalize_to_macros_2_0();
1612 let mut use_prelude = !module.no_implicit_prelude;
1615 let visit = match scope {
1616 // Derive helpers are not in scope when resolving derives in the same container.
1617 Scope::DeriveHelpers(expn_id) => {
1618 !(expn_id == parent_scope.expansion && macro_kind == Some(MacroKind::Derive))
1620 Scope::DeriveHelpersCompat => true,
1621 Scope::MacroRules(..) => true,
1622 Scope::CrateRoot => true,
1623 Scope::Module(..) => true,
1624 Scope::RegisteredAttrs => use_prelude,
1625 Scope::MacroUsePrelude => use_prelude || rust_2015,
1626 Scope::BuiltinAttrs => true,
1627 Scope::ExternPrelude => use_prelude || is_absolute_path,
1628 Scope::ToolPrelude => use_prelude,
1629 Scope::StdLibPrelude => use_prelude || ns == MacroNS,
1630 Scope::BuiltinTypes => true,
1634 if let break_result @ Some(..) = visitor(self, scope, use_prelude, ident) {
1635 return break_result;
1639 scope = match scope {
1640 Scope::DeriveHelpers(expn_id) if expn_id != ExpnId::root() => {
1641 // Derive helpers are not visible to code generated by bang or derive macros.
1642 let expn_data = expn_id.expn_data();
1643 match expn_data.kind {
1645 | ExpnKind::Macro(MacroKind::Bang | MacroKind::Derive, _) => {
1646 Scope::DeriveHelpersCompat
1648 _ => Scope::DeriveHelpers(expn_data.parent),
1651 Scope::DeriveHelpers(..) => Scope::DeriveHelpersCompat,
1652 Scope::DeriveHelpersCompat => Scope::MacroRules(parent_scope.macro_rules),
1653 Scope::MacroRules(macro_rules_scope) => match macro_rules_scope {
1654 MacroRulesScope::Binding(binding) => {
1655 Scope::MacroRules(binding.parent_macro_rules_scope)
1657 MacroRulesScope::Invocation(invoc_id) => Scope::MacroRules(
1658 self.output_macro_rules_scopes
1661 .unwrap_or(self.invocation_parent_scopes[&invoc_id].macro_rules),
1663 MacroRulesScope::Empty => Scope::Module(module),
1665 Scope::CrateRoot => match ns {
1667 ident.span.adjust(ExpnId::root());
1668 Scope::ExternPrelude
1670 ValueNS | MacroNS => break,
1672 Scope::Module(module) => {
1673 use_prelude = !module.no_implicit_prelude;
1674 match self.hygienic_lexical_parent(module, &mut ident.span) {
1675 Some(parent_module) => Scope::Module(parent_module),
1677 ident.span.adjust(ExpnId::root());
1679 TypeNS => Scope::ExternPrelude,
1680 ValueNS => Scope::StdLibPrelude,
1681 MacroNS => Scope::RegisteredAttrs,
1686 Scope::RegisteredAttrs => Scope::MacroUsePrelude,
1687 Scope::MacroUsePrelude => Scope::StdLibPrelude,
1688 Scope::BuiltinAttrs => break, // nowhere else to search
1689 Scope::ExternPrelude if is_absolute_path => break,
1690 Scope::ExternPrelude => Scope::ToolPrelude,
1691 Scope::ToolPrelude => Scope::StdLibPrelude,
1692 Scope::StdLibPrelude => match ns {
1693 TypeNS => Scope::BuiltinTypes,
1694 ValueNS => break, // nowhere else to search
1695 MacroNS => Scope::BuiltinAttrs,
1697 Scope::BuiltinTypes => break, // nowhere else to search
1704 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1705 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1706 /// `ident` in the first scope that defines it (or None if no scopes define it).
1708 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1709 /// the items are defined in the block. For example,
1712 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1715 /// g(); // This resolves to the local variable `g` since it shadows the item.
1719 /// Invariant: This must only be called during main resolution, not during
1720 /// import resolution.
1721 fn resolve_ident_in_lexical_scope(
1725 parent_scope: &ParentScope<'a>,
1726 record_used_id: Option<NodeId>,
1729 ) -> Option<LexicalScopeBinding<'a>> {
1730 assert!(ns == TypeNS || ns == ValueNS);
1731 if ident.name == kw::Invalid {
1732 return Some(LexicalScopeBinding::Res(Res::Err));
1734 let (general_span, normalized_span) = if ident.name == kw::SelfUpper {
1735 // FIXME(jseyfried) improve `Self` hygiene
1736 let empty_span = ident.span.with_ctxt(SyntaxContext::root());
1737 (empty_span, empty_span)
1738 } else if ns == TypeNS {
1739 let normalized_span = ident.span.normalize_to_macros_2_0();
1740 (normalized_span, normalized_span)
1742 (ident.span.normalize_to_macro_rules(), ident.span.normalize_to_macros_2_0())
1744 ident.span = general_span;
1745 let normalized_ident = Ident { span: normalized_span, ..ident };
1747 // Walk backwards up the ribs in scope.
1748 let record_used = record_used_id.is_some();
1749 let mut module = self.graph_root;
1750 for i in (0..ribs.len()).rev() {
1751 debug!("walk rib\n{:?}", ribs[i].bindings);
1752 // Use the rib kind to determine whether we are resolving parameters
1753 // (macro 2.0 hygiene) or local variables (`macro_rules` hygiene).
1754 let rib_ident = if ribs[i].kind.contains_params() { normalized_ident } else { ident };
1755 if let Some(res) = ribs[i].bindings.get(&rib_ident).cloned() {
1756 // The ident resolves to a type parameter or local variable.
1757 return Some(LexicalScopeBinding::Res(self.validate_res_from_ribs(
1767 module = match ribs[i].kind {
1768 ModuleRibKind(module) => module,
1769 MacroDefinition(def) if def == self.macro_def(ident.span.ctxt()) => {
1770 // If an invocation of this macro created `ident`, give up on `ident`
1771 // and switch to `ident`'s source from the macro definition.
1772 ident.span.remove_mark();
1778 let item = self.resolve_ident_in_module_unadjusted(
1779 ModuleOrUniformRoot::Module(module),
1786 if let Ok(binding) = item {
1787 // The ident resolves to an item.
1788 return Some(LexicalScopeBinding::Item(binding));
1792 ModuleKind::Block(..) => {} // We can see through blocks
1797 ident = normalized_ident;
1798 let mut poisoned = None;
1800 let opt_module = if let Some(node_id) = record_used_id {
1801 self.hygienic_lexical_parent_with_compatibility_fallback(
1808 self.hygienic_lexical_parent(module, &mut ident.span)
1810 module = unwrap_or!(opt_module, break);
1811 let adjusted_parent_scope = &ParentScope { module, ..*parent_scope };
1812 let result = self.resolve_ident_in_module_unadjusted(
1813 ModuleOrUniformRoot::Module(module),
1816 adjusted_parent_scope,
1823 if let Some(node_id) = poisoned {
1824 self.lint_buffer.buffer_lint_with_diagnostic(
1825 lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
1828 &format!("cannot find {} `{}` in this scope", ns.descr(), ident),
1829 BuiltinLintDiagnostics::ProcMacroDeriveResolutionFallback(ident.span),
1832 return Some(LexicalScopeBinding::Item(binding));
1834 Err(Determined) => continue,
1835 Err(Undetermined) => {
1836 span_bug!(ident.span, "undetermined resolution during main resolution pass")
1841 if !module.no_implicit_prelude {
1842 ident.span.adjust(ExpnId::root());
1844 if let Some(binding) = self.extern_prelude_get(ident, !record_used) {
1845 return Some(LexicalScopeBinding::Item(binding));
1847 if let Some(ident) = self.registered_tools.get(&ident) {
1849 (Res::ToolMod, ty::Visibility::Public, ident.span, ExpnId::root())
1850 .to_name_binding(self.arenas);
1851 return Some(LexicalScopeBinding::Item(binding));
1854 if let Some(prelude) = self.prelude {
1855 if let Ok(binding) = self.resolve_ident_in_module_unadjusted(
1856 ModuleOrUniformRoot::Module(prelude),
1863 return Some(LexicalScopeBinding::Item(binding));
1869 if let Some(prim_ty) = self.primitive_type_table.primitive_types.get(&ident.name) {
1871 (Res::PrimTy(*prim_ty), ty::Visibility::Public, DUMMY_SP, ExpnId::root())
1872 .to_name_binding(self.arenas);
1873 return Some(LexicalScopeBinding::Item(binding));
1880 fn hygienic_lexical_parent(
1884 ) -> Option<Module<'a>> {
1885 if !module.expansion.outer_expn_is_descendant_of(span.ctxt()) {
1886 return Some(self.macro_def_scope(span.remove_mark()));
1889 if let ModuleKind::Block(..) = module.kind {
1890 return Some(module.parent.unwrap().nearest_item_scope());
1896 fn hygienic_lexical_parent_with_compatibility_fallback(
1901 poisoned: &mut Option<NodeId>,
1902 ) -> Option<Module<'a>> {
1903 if let module @ Some(..) = self.hygienic_lexical_parent(module, span) {
1907 // We need to support the next case under a deprecation warning
1910 // ---- begin: this comes from a proc macro derive
1911 // mod implementation_details {
1912 // // Note that `MyStruct` is not in scope here.
1913 // impl SomeTrait for MyStruct { ... }
1917 // So we have to fall back to the module's parent during lexical resolution in this case.
1918 if let Some(parent) = module.parent {
1919 // Inner module is inside the macro, parent module is outside of the macro.
1920 if module.expansion != parent.expansion
1921 && module.expansion.is_descendant_of(parent.expansion)
1923 // The macro is a proc macro derive
1924 if let Some(def_id) = module.expansion.expn_data().macro_def_id {
1925 if let Some(ext) = self.get_macro_by_def_id(def_id) {
1926 if !ext.is_builtin && ext.macro_kind() == MacroKind::Derive {
1927 if parent.expansion.outer_expn_is_descendant_of(span.ctxt()) {
1928 *poisoned = Some(node_id);
1929 return module.parent;
1940 fn resolve_ident_in_module(
1942 module: ModuleOrUniformRoot<'a>,
1945 parent_scope: &ParentScope<'a>,
1948 ) -> Result<&'a NameBinding<'a>, Determinacy> {
1949 self.resolve_ident_in_module_ext(module, ident, ns, parent_scope, record_used, path_span)
1950 .map_err(|(determinacy, _)| determinacy)
1953 fn resolve_ident_in_module_ext(
1955 module: ModuleOrUniformRoot<'a>,
1958 parent_scope: &ParentScope<'a>,
1961 ) -> Result<&'a NameBinding<'a>, (Determinacy, Weak)> {
1962 let tmp_parent_scope;
1963 let mut adjusted_parent_scope = parent_scope;
1965 ModuleOrUniformRoot::Module(m) => {
1966 if let Some(def) = ident.span.normalize_to_macros_2_0_and_adjust(m.expansion) {
1968 ParentScope { module: self.macro_def_scope(def), ..*parent_scope };
1969 adjusted_parent_scope = &tmp_parent_scope;
1972 ModuleOrUniformRoot::ExternPrelude => {
1973 ident.span.normalize_to_macros_2_0_and_adjust(ExpnId::root());
1975 ModuleOrUniformRoot::CrateRootAndExternPrelude | ModuleOrUniformRoot::CurrentScope => {
1979 self.resolve_ident_in_module_unadjusted_ext(
1983 adjusted_parent_scope,
1990 fn resolve_crate_root(&mut self, ident: Ident) -> Module<'a> {
1991 debug!("resolve_crate_root({:?})", ident);
1992 let mut ctxt = ident.span.ctxt();
1993 let mark = if ident.name == kw::DollarCrate {
1994 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
1995 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
1996 // as described in `SyntaxContext::apply_mark`, so we ignore prepended opaque marks.
1997 // FIXME: This is only a guess and it doesn't work correctly for `macro_rules!`
1998 // definitions actually produced by `macro` and `macro` definitions produced by
1999 // `macro_rules!`, but at least such configurations are not stable yet.
2000 ctxt = ctxt.normalize_to_macro_rules();
2002 "resolve_crate_root: marks={:?}",
2003 ctxt.marks().into_iter().map(|(i, t)| (i.expn_data(), t)).collect::<Vec<_>>()
2005 let mut iter = ctxt.marks().into_iter().rev().peekable();
2006 let mut result = None;
2007 // Find the last opaque mark from the end if it exists.
2008 while let Some(&(mark, transparency)) = iter.peek() {
2009 if transparency == Transparency::Opaque {
2010 result = Some(mark);
2017 "resolve_crate_root: found opaque mark {:?} {:?}",
2019 result.map(|r| r.expn_data())
2021 // Then find the last semi-transparent mark from the end if it exists.
2022 for (mark, transparency) in iter {
2023 if transparency == Transparency::SemiTransparent {
2024 result = Some(mark);
2030 "resolve_crate_root: found semi-transparent mark {:?} {:?}",
2032 result.map(|r| r.expn_data())
2036 debug!("resolve_crate_root: not DollarCrate");
2037 ctxt = ctxt.normalize_to_macros_2_0();
2038 ctxt.adjust(ExpnId::root())
2040 let module = match mark {
2041 Some(def) => self.macro_def_scope(def),
2044 "resolve_crate_root({:?}): found no mark (ident.span = {:?})",
2047 return self.graph_root;
2050 let module = self.get_module(DefId { index: CRATE_DEF_INDEX, ..module.normal_ancestor_id });
2052 "resolve_crate_root({:?}): got module {:?} ({:?}) (ident.span = {:?})",
2061 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
2062 let mut module = self.get_module(module.normal_ancestor_id);
2063 while module.span.ctxt().normalize_to_macros_2_0() != *ctxt {
2064 let parent = module.parent.unwrap_or_else(|| self.macro_def_scope(ctxt.remove_mark()));
2065 module = self.get_module(parent.normal_ancestor_id);
2073 opt_ns: Option<Namespace>, // `None` indicates a module path in import
2074 parent_scope: &ParentScope<'a>,
2077 crate_lint: CrateLint,
2078 ) -> PathResult<'a> {
2079 self.resolve_path_with_ribs(
2090 fn resolve_path_with_ribs(
2093 opt_ns: Option<Namespace>, // `None` indicates a module path in import
2094 parent_scope: &ParentScope<'a>,
2097 crate_lint: CrateLint,
2098 ribs: Option<&PerNS<Vec<Rib<'a>>>>,
2099 ) -> PathResult<'a> {
2100 let mut module = None;
2101 let mut allow_super = true;
2102 let mut second_binding = None;
2105 "resolve_path(path={:?}, opt_ns={:?}, record_used={:?}, \
2106 path_span={:?}, crate_lint={:?})",
2107 path, opt_ns, record_used, path_span, crate_lint,
2110 for (i, &Segment { ident, id, has_generic_args: _ }) in path.iter().enumerate() {
2111 debug!("resolve_path ident {} {:?} {:?}", i, ident, id);
2112 let record_segment_res = |this: &mut Self, res| {
2114 if let Some(id) = id {
2115 if !this.partial_res_map.contains_key(&id) {
2116 assert!(id != ast::DUMMY_NODE_ID, "Trying to resolve dummy id");
2117 this.record_partial_res(id, PartialRes::new(res));
2123 let is_last = i == path.len() - 1;
2124 let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
2125 let name = ident.name;
2127 allow_super &= ns == TypeNS && (name == kw::SelfLower || name == kw::Super);
2130 if allow_super && name == kw::Super {
2131 let mut ctxt = ident.span.ctxt().normalize_to_macros_2_0();
2132 let self_module = match i {
2133 0 => Some(self.resolve_self(&mut ctxt, parent_scope.module)),
2135 Some(ModuleOrUniformRoot::Module(module)) => Some(module),
2139 if let Some(self_module) = self_module {
2140 if let Some(parent) = self_module.parent {
2141 module = Some(ModuleOrUniformRoot::Module(
2142 self.resolve_self(&mut ctxt, parent),
2147 let msg = "there are too many leading `super` keywords".to_string();
2148 return PathResult::Failed {
2152 is_error_from_last_segment: false,
2156 if name == kw::SelfLower {
2157 let mut ctxt = ident.span.ctxt().normalize_to_macros_2_0();
2158 module = Some(ModuleOrUniformRoot::Module(
2159 self.resolve_self(&mut ctxt, parent_scope.module),
2163 if name == kw::PathRoot && ident.span.rust_2018() {
2164 module = Some(ModuleOrUniformRoot::ExternPrelude);
2167 if name == kw::PathRoot && ident.span.rust_2015() && self.session.rust_2018() {
2168 // `::a::b` from 2015 macro on 2018 global edition
2169 module = Some(ModuleOrUniformRoot::CrateRootAndExternPrelude);
2172 if name == kw::PathRoot || name == kw::Crate || name == kw::DollarCrate {
2173 // `::a::b`, `crate::a::b` or `$crate::a::b`
2174 module = Some(ModuleOrUniformRoot::Module(self.resolve_crate_root(ident)));
2180 // Report special messages for path segment keywords in wrong positions.
2181 if ident.is_path_segment_keyword() && i != 0 {
2182 let name_str = if name == kw::PathRoot {
2183 "crate root".to_string()
2185 format!("`{}`", name)
2187 let label = if i == 1 && path[0].ident.name == kw::PathRoot {
2188 format!("global paths cannot start with {}", name_str)
2190 format!("{} in paths can only be used in start position", name_str)
2192 return PathResult::Failed {
2196 is_error_from_last_segment: false,
2200 enum FindBindingResult<'a> {
2201 Binding(Result<&'a NameBinding<'a>, Determinacy>),
2202 PathResult(PathResult<'a>),
2204 let find_binding_in_ns = |this: &mut Self, ns| {
2205 let binding = if let Some(module) = module {
2206 this.resolve_ident_in_module(
2214 } else if ribs.is_none() || opt_ns.is_none() || opt_ns == Some(MacroNS) {
2215 let scopes = ScopeSet::All(ns, opt_ns.is_none());
2216 this.early_resolve_ident_in_lexical_scope(
2225 let record_used_id = if record_used {
2226 crate_lint.node_id().or(Some(CRATE_NODE_ID))
2230 match this.resolve_ident_in_lexical_scope(
2238 // we found a locally-imported or available item/module
2239 Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
2240 // we found a local variable or type param
2241 Some(LexicalScopeBinding::Res(res))
2242 if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) =>
2244 record_segment_res(this, res);
2245 return FindBindingResult::PathResult(PathResult::NonModule(
2246 PartialRes::with_unresolved_segments(res, path.len() - 1),
2249 _ => Err(Determinacy::determined(record_used)),
2252 FindBindingResult::Binding(binding)
2254 let binding = match find_binding_in_ns(self, ns) {
2255 FindBindingResult::PathResult(x) => return x,
2256 FindBindingResult::Binding(binding) => binding,
2261 second_binding = Some(binding);
2263 let res = binding.res();
2264 let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(res);
2265 if let Some(next_module) = binding.module() {
2266 module = Some(ModuleOrUniformRoot::Module(next_module));
2267 record_segment_res(self, res);
2268 } else if res == Res::ToolMod && i + 1 != path.len() {
2269 if binding.is_import() {
2273 "cannot use a tool module through an import",
2275 .span_note(binding.span, "the tool module imported here")
2278 let res = Res::NonMacroAttr(NonMacroAttrKind::Tool);
2279 return PathResult::NonModule(PartialRes::new(res));
2280 } else if res == Res::Err {
2281 return PathResult::NonModule(PartialRes::new(Res::Err));
2282 } else if opt_ns.is_some() && (is_last || maybe_assoc) {
2283 self.lint_if_path_starts_with_module(
2289 return PathResult::NonModule(PartialRes::with_unresolved_segments(
2294 let label = format!(
2295 "`{}` is {} {}, not a module",
2301 return PathResult::Failed {
2305 is_error_from_last_segment: is_last,
2309 Err(Undetermined) => return PathResult::Indeterminate,
2310 Err(Determined) => {
2311 if let Some(ModuleOrUniformRoot::Module(module)) = module {
2312 if opt_ns.is_some() && !module.is_normal() {
2313 return PathResult::NonModule(PartialRes::with_unresolved_segments(
2314 module.res().unwrap(),
2319 let module_res = match module {
2320 Some(ModuleOrUniformRoot::Module(module)) => module.res(),
2323 let (label, suggestion) = if module_res == self.graph_root.res() {
2324 let is_mod = |res| match res {
2325 Res::Def(DefKind::Mod, _) => true,
2328 let mut candidates =
2329 self.lookup_import_candidates(ident, TypeNS, parent_scope, is_mod);
2330 candidates.sort_by_cached_key(|c| {
2331 (c.path.segments.len(), pprust::path_to_string(&c.path))
2333 if let Some(candidate) = candidates.get(0) {
2335 String::from("unresolved import"),
2337 vec![(ident.span, pprust::path_to_string(&candidate.path))],
2338 String::from("a similar path exists"),
2339 Applicability::MaybeIncorrect,
2343 (format!("maybe a missing crate `{}`?", ident), None)
2346 (format!("use of undeclared type or module `{}`", ident), None)
2349 format!("could not find `{}` in `{}`", ident, path[i - 1].ident);
2350 if ns == TypeNS || ns == ValueNS {
2351 let ns_to_try = if ns == TypeNS { ValueNS } else { TypeNS };
2352 if let FindBindingResult::Binding(Ok(binding)) =
2353 find_binding_in_ns(self, ns_to_try)
2355 let mut found = |what| {
2357 "expected {}, found {} `{}` in `{}`",
2364 if binding.module().is_some() {
2367 match binding.res() {
2368 def::Res::<NodeId>::Def(kind, id) => found(kind.descr(id)),
2369 _ => found(ns_to_try.descr()),
2376 return PathResult::Failed {
2380 is_error_from_last_segment: is_last,
2386 self.lint_if_path_starts_with_module(crate_lint, path, path_span, second_binding);
2388 PathResult::Module(match module {
2389 Some(module) => module,
2390 None if path.is_empty() => ModuleOrUniformRoot::CurrentScope,
2391 _ => span_bug!(path_span, "resolve_path: non-empty path `{:?}` has no module", path),
2395 fn lint_if_path_starts_with_module(
2397 crate_lint: CrateLint,
2400 second_binding: Option<&NameBinding<'_>>,
2402 let (diag_id, diag_span) = match crate_lint {
2403 CrateLint::No => return,
2404 CrateLint::SimplePath(id) => (id, path_span),
2405 CrateLint::UsePath { root_id, root_span } => (root_id, root_span),
2406 CrateLint::QPathTrait { qpath_id, qpath_span } => (qpath_id, qpath_span),
2409 let first_name = match path.get(0) {
2410 // In the 2018 edition this lint is a hard error, so nothing to do
2411 Some(seg) if seg.ident.span.rust_2015() && self.session.rust_2015() => seg.ident.name,
2415 // We're only interested in `use` paths which should start with
2416 // `{{root}}` currently.
2417 if first_name != kw::PathRoot {
2422 // If this import looks like `crate::...` it's already good
2423 Some(Segment { ident, .. }) if ident.name == kw::Crate => return,
2424 // Otherwise go below to see if it's an extern crate
2426 // If the path has length one (and it's `PathRoot` most likely)
2427 // then we don't know whether we're gonna be importing a crate or an
2428 // item in our crate. Defer this lint to elsewhere
2432 // If the first element of our path was actually resolved to an
2433 // `ExternCrate` (also used for `crate::...`) then no need to issue a
2434 // warning, this looks all good!
2435 if let Some(binding) = second_binding {
2436 if let NameBindingKind::Import { import, .. } = binding.kind {
2437 // Careful: we still want to rewrite paths from renamed extern crates.
2438 if let ImportKind::ExternCrate { source: None, .. } = import.kind {
2444 let diag = BuiltinLintDiagnostics::AbsPathWithModule(diag_span);
2445 self.lint_buffer.buffer_lint_with_diagnostic(
2446 lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
2449 "absolute paths must start with `self`, `super`, \
2450 `crate`, or an external crate name in the 2018 edition",
2455 // Validate a local resolution (from ribs).
2456 fn validate_res_from_ribs(
2463 all_ribs: &[Rib<'a>],
2465 debug!("validate_res_from_ribs({:?})", res);
2466 let ribs = &all_ribs[rib_index + 1..];
2468 // An invalid forward use of a type parameter from a previous default.
2469 if let ForwardTyParamBanRibKind = all_ribs[rib_index].kind {
2471 let res_error = if rib_ident.name == kw::SelfUpper {
2472 ResolutionError::SelfInTyParamDefault
2474 ResolutionError::ForwardDeclaredTyParam
2476 self.report_error(span, res_error);
2478 assert_eq!(res, Res::Err);
2484 use ResolutionError::*;
2485 let mut res_err = None;
2490 | ClosureOrAsyncRibKind
2492 | MacroDefinition(..)
2493 | ForwardTyParamBanRibKind => {
2494 // Nothing to do. Continue.
2496 ItemRibKind(_) | FnItemRibKind | AssocItemRibKind => {
2497 // This was an attempt to access an upvar inside a
2498 // named function item. This is not allowed, so we
2501 // We don't immediately trigger a resolve error, because
2502 // we want certain other resolution errors (namely those
2503 // emitted for `ConstantItemRibKind` below) to take
2505 res_err = Some(CannotCaptureDynamicEnvironmentInFnItem);
2508 ConstantItemRibKind => {
2509 // Still doesn't deal with upvars
2511 self.report_error(span, AttemptToUseNonConstantValueInConstant);
2515 ConstParamTyRibKind => {
2517 self.report_error(span, ParamInTyOfConstArg(rib_ident.name));
2523 if let Some(res_err) = res_err {
2524 self.report_error(span, res_err);
2528 Res::Def(DefKind::TyParam, _) | Res::SelfTy(..) => {
2530 let has_generic_params = match rib.kind {
2532 | ClosureOrAsyncRibKind
2535 | MacroDefinition(..)
2536 | ForwardTyParamBanRibKind
2537 | ConstantItemRibKind => {
2538 // Nothing to do. Continue.
2541 // This was an attempt to use a type parameter outside its scope.
2542 ItemRibKind(has_generic_params) => has_generic_params,
2543 FnItemRibKind => HasGenericParams::Yes,
2544 ConstParamTyRibKind => {
2548 ResolutionError::ParamInTyOfConstArg(rib_ident.name),
2558 ResolutionError::GenericParamsFromOuterFunction(
2567 Res::Def(DefKind::ConstParam, _) => {
2568 let mut ribs = ribs.iter().peekable();
2569 if let Some(Rib { kind: FnItemRibKind, .. }) = ribs.peek() {
2570 // When declaring const parameters inside function signatures, the first rib
2571 // is always a `FnItemRibKind`. In this case, we can skip it, to avoid it
2572 // (spuriously) conflicting with the const param.
2576 let has_generic_params = match rib.kind {
2578 | ClosureOrAsyncRibKind
2581 | MacroDefinition(..)
2582 | ForwardTyParamBanRibKind
2583 | ConstantItemRibKind => continue,
2584 ItemRibKind(has_generic_params) => has_generic_params,
2585 FnItemRibKind => HasGenericParams::Yes,
2586 ConstParamTyRibKind => {
2590 ResolutionError::ParamInTyOfConstArg(rib_ident.name),
2597 // This was an attempt to use a const parameter outside its scope.
2601 ResolutionError::GenericParamsFromOuterFunction(
2615 fn record_partial_res(&mut self, node_id: NodeId, resolution: PartialRes) {
2616 debug!("(recording res) recording {:?} for {}", resolution, node_id);
2617 if let Some(prev_res) = self.partial_res_map.insert(node_id, resolution) {
2618 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
2622 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
2623 vis.is_accessible_from(module.normal_ancestor_id, self)
2626 fn set_binding_parent_module(&mut self, binding: &'a NameBinding<'a>, module: Module<'a>) {
2627 if let Some(old_module) = self.binding_parent_modules.insert(PtrKey(binding), module) {
2628 if !ptr::eq(module, old_module) {
2629 span_bug!(binding.span, "parent module is reset for binding");
2634 fn disambiguate_macro_rules_vs_modularized(
2636 macro_rules: &'a NameBinding<'a>,
2637 modularized: &'a NameBinding<'a>,
2639 // Some non-controversial subset of ambiguities "modularized macro name" vs "macro_rules"
2640 // is disambiguated to mitigate regressions from macro modularization.
2641 // Scoping for `macro_rules` behaves like scoping for `let` at module level, in general.
2643 self.binding_parent_modules.get(&PtrKey(macro_rules)),
2644 self.binding_parent_modules.get(&PtrKey(modularized)),
2646 (Some(macro_rules), Some(modularized)) => {
2647 macro_rules.normal_ancestor_id == modularized.normal_ancestor_id
2648 && modularized.is_ancestor_of(macro_rules)
2654 fn report_errors(&mut self, krate: &Crate) {
2655 self.report_with_use_injections(krate);
2657 for &(span_use, span_def) in &self.macro_expanded_macro_export_errors {
2658 let msg = "macro-expanded `macro_export` macros from the current crate \
2659 cannot be referred to by absolute paths";
2660 self.lint_buffer.buffer_lint_with_diagnostic(
2661 lint::builtin::MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS,
2665 BuiltinLintDiagnostics::MacroExpandedMacroExportsAccessedByAbsolutePaths(span_def),
2669 for ambiguity_error in &self.ambiguity_errors {
2670 self.report_ambiguity_error(ambiguity_error);
2673 let mut reported_spans = FxHashSet::default();
2674 for error in &self.privacy_errors {
2675 if reported_spans.insert(error.dedup_span) {
2676 self.report_privacy_error(error);
2681 fn report_with_use_injections(&mut self, krate: &Crate) {
2682 for UseError { mut err, candidates, def_id, instead, suggestion } in
2683 self.use_injections.drain(..)
2685 let (span, found_use) = if let Some(def_id) = def_id.as_local() {
2686 UsePlacementFinder::check(krate, self.def_id_to_node_id[def_id])
2690 if !candidates.is_empty() {
2691 diagnostics::show_candidates(&mut err, span, &candidates, instead, found_use);
2692 } else if let Some((span, msg, sugg, appl)) = suggestion {
2693 err.span_suggestion(span, msg, sugg, appl);
2699 fn report_conflict<'b>(
2704 new_binding: &NameBinding<'b>,
2705 old_binding: &NameBinding<'b>,
2707 // Error on the second of two conflicting names
2708 if old_binding.span.lo() > new_binding.span.lo() {
2709 return self.report_conflict(parent, ident, ns, old_binding, new_binding);
2712 let container = match parent.kind {
2713 ModuleKind::Def(kind, _, _) => kind.descr(parent.def_id().unwrap()),
2714 ModuleKind::Block(..) => "block",
2717 let old_noun = match old_binding.is_import() {
2719 false => "definition",
2722 let new_participle = match new_binding.is_import() {
2728 (ident.name, self.session.source_map().guess_head_span(new_binding.span));
2730 if let Some(s) = self.name_already_seen.get(&name) {
2736 let old_kind = match (ns, old_binding.module()) {
2737 (ValueNS, _) => "value",
2738 (MacroNS, _) => "macro",
2739 (TypeNS, _) if old_binding.is_extern_crate() => "extern crate",
2740 (TypeNS, Some(module)) if module.is_normal() => "module",
2741 (TypeNS, Some(module)) if module.is_trait() => "trait",
2742 (TypeNS, _) => "type",
2745 let msg = format!("the name `{}` is defined multiple times", name);
2747 let mut err = match (old_binding.is_extern_crate(), new_binding.is_extern_crate()) {
2748 (true, true) => struct_span_err!(self.session, span, E0259, "{}", msg),
2749 (true, _) | (_, true) => match new_binding.is_import() && old_binding.is_import() {
2750 true => struct_span_err!(self.session, span, E0254, "{}", msg),
2751 false => struct_span_err!(self.session, span, E0260, "{}", msg),
2753 _ => match (old_binding.is_import(), new_binding.is_import()) {
2754 (false, false) => struct_span_err!(self.session, span, E0428, "{}", msg),
2755 (true, true) => struct_span_err!(self.session, span, E0252, "{}", msg),
2756 _ => struct_span_err!(self.session, span, E0255, "{}", msg),
2761 "`{}` must be defined only once in the {} namespace of this {}",
2767 err.span_label(span, format!("`{}` re{} here", name, new_participle));
2769 self.session.source_map().guess_head_span(old_binding.span),
2770 format!("previous {} of the {} `{}` here", old_noun, old_kind, name),
2773 // See https://github.com/rust-lang/rust/issues/32354
2774 use NameBindingKind::Import;
2775 let import = match (&new_binding.kind, &old_binding.kind) {
2776 // If there are two imports where one or both have attributes then prefer removing the
2777 // import without attributes.
2778 (Import { import: new, .. }, Import { import: old, .. })
2780 !new_binding.span.is_dummy()
2781 && !old_binding.span.is_dummy()
2782 && (new.has_attributes || old.has_attributes)
2785 if old.has_attributes {
2786 Some((new, new_binding.span, true))
2788 Some((old, old_binding.span, true))
2791 // Otherwise prioritize the new binding.
2792 (Import { import, .. }, other) if !new_binding.span.is_dummy() => {
2793 Some((import, new_binding.span, other.is_import()))
2795 (other, Import { import, .. }) if !old_binding.span.is_dummy() => {
2796 Some((import, old_binding.span, other.is_import()))
2801 // Check if the target of the use for both bindings is the same.
2802 let duplicate = new_binding.res().opt_def_id() == old_binding.res().opt_def_id();
2803 let has_dummy_span = new_binding.span.is_dummy() || old_binding.span.is_dummy();
2805 self.extern_prelude.get(&ident).map(|entry| entry.introduced_by_item).unwrap_or(true);
2806 // Only suggest removing an import if both bindings are to the same def, if both spans
2807 // aren't dummy spans. Further, if both bindings are imports, then the ident must have
2808 // been introduced by a item.
2809 let should_remove_import = duplicate
2811 && ((new_binding.is_extern_crate() || old_binding.is_extern_crate()) || from_item);
2814 Some((import, span, true)) if should_remove_import && import.is_nested() => {
2815 self.add_suggestion_for_duplicate_nested_use(&mut err, import, span)
2817 Some((import, _, true)) if should_remove_import && !import.is_glob() => {
2818 // Simple case - remove the entire import. Due to the above match arm, this can
2819 // only be a single use so just remove it entirely.
2820 err.tool_only_span_suggestion(
2821 import.use_span_with_attributes,
2822 "remove unnecessary import",
2824 Applicability::MaybeIncorrect,
2827 Some((import, span, _)) => {
2828 self.add_suggestion_for_rename_of_use(&mut err, name, import, span)
2834 self.name_already_seen.insert(name, span);
2837 /// This function adds a suggestion to change the binding name of a new import that conflicts
2838 /// with an existing import.
2840 /// ```text,ignore (diagnostic)
2841 /// help: you can use `as` to change the binding name of the import
2843 /// LL | use foo::bar as other_bar;
2844 /// | ^^^^^^^^^^^^^^^^^^^^^
2846 fn add_suggestion_for_rename_of_use(
2848 err: &mut DiagnosticBuilder<'_>,
2850 import: &Import<'_>,
2853 let suggested_name = if name.as_str().chars().next().unwrap().is_uppercase() {
2854 format!("Other{}", name)
2856 format!("other_{}", name)
2859 let mut suggestion = None;
2861 ImportKind::Single { type_ns_only: true, .. } => {
2862 suggestion = Some(format!("self as {}", suggested_name))
2864 ImportKind::Single { source, .. } => {
2866 source.span.hi().0.checked_sub(binding_span.lo().0).map(|pos| pos as usize)
2868 if let Ok(snippet) = self.session.source_map().span_to_snippet(binding_span) {
2869 if pos <= snippet.len() {
2870 suggestion = Some(format!(
2874 if snippet.ends_with(';') { ";" } else { "" }
2880 ImportKind::ExternCrate { source, target, .. } => {
2881 suggestion = Some(format!(
2882 "extern crate {} as {};",
2883 source.unwrap_or(target.name),
2887 _ => unreachable!(),
2890 let rename_msg = "you can use `as` to change the binding name of the import";
2891 if let Some(suggestion) = suggestion {
2892 err.span_suggestion(
2896 Applicability::MaybeIncorrect,
2899 err.span_label(binding_span, rename_msg);
2903 /// This function adds a suggestion to remove a unnecessary binding from an import that is
2904 /// nested. In the following example, this function will be invoked to remove the `a` binding
2905 /// in the second use statement:
2907 /// ```ignore (diagnostic)
2908 /// use issue_52891::a;
2909 /// use issue_52891::{d, a, e};
2912 /// The following suggestion will be added:
2914 /// ```ignore (diagnostic)
2915 /// use issue_52891::{d, a, e};
2916 /// ^-- help: remove unnecessary import
2919 /// If the nested use contains only one import then the suggestion will remove the entire
2922 /// It is expected that the provided import is nested - this isn't checked by the
2923 /// function. If this invariant is not upheld, this function's behaviour will be unexpected
2924 /// as characters expected by span manipulations won't be present.
2925 fn add_suggestion_for_duplicate_nested_use(
2927 err: &mut DiagnosticBuilder<'_>,
2928 import: &Import<'_>,
2931 assert!(import.is_nested());
2932 let message = "remove unnecessary import";
2934 // Two examples will be used to illustrate the span manipulations we're doing:
2936 // - Given `use issue_52891::{d, a, e};` where `a` is a duplicate then `binding_span` is
2937 // `a` and `import.use_span` is `issue_52891::{d, a, e};`.
2938 // - Given `use issue_52891::{d, e, a};` where `a` is a duplicate then `binding_span` is
2939 // `a` and `import.use_span` is `issue_52891::{d, e, a};`.
2941 let (found_closing_brace, span) =
2942 find_span_of_binding_until_next_binding(self.session, binding_span, import.use_span);
2944 // If there was a closing brace then identify the span to remove any trailing commas from
2945 // previous imports.
2946 if found_closing_brace {
2947 if let Some(span) = extend_span_to_previous_binding(self.session, span) {
2948 err.tool_only_span_suggestion(
2952 Applicability::MaybeIncorrect,
2955 // Remove the entire line if we cannot extend the span back, this indicates a
2956 // `issue_52891::{self}` case.
2957 err.span_suggestion(
2958 import.use_span_with_attributes,
2961 Applicability::MaybeIncorrect,
2968 err.span_suggestion(span, message, String::new(), Applicability::MachineApplicable);
2971 fn extern_prelude_get(
2975 ) -> Option<&'a NameBinding<'a>> {
2976 if ident.is_path_segment_keyword() {
2977 // Make sure `self`, `super` etc produce an error when passed to here.
2980 self.extern_prelude.get(&ident.normalize_to_macros_2_0()).cloned().and_then(|entry| {
2981 if let Some(binding) = entry.extern_crate_item {
2982 if !speculative && entry.introduced_by_item {
2983 self.record_use(ident, TypeNS, binding, false);
2987 let crate_id = if !speculative {
2988 self.crate_loader.process_path_extern(ident.name, ident.span)
2990 self.crate_loader.maybe_process_path_extern(ident.name)?
2992 let crate_root = self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
2994 (crate_root, ty::Visibility::Public, DUMMY_SP, ExpnId::root())
2995 .to_name_binding(self.arenas),
3001 /// Rustdoc uses this to resolve things in a recoverable way. `ResolutionError<'a>`
3002 /// isn't something that can be returned because it can't be made to live that long,
3003 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
3004 /// just that an error occurred.
3005 // FIXME(Manishearth): intra-doc links won't get warned of epoch changes.
3006 pub fn resolve_str_path_error(
3012 ) -> Result<(ast::Path, Res), ()> {
3013 let path = if path_str.starts_with("::") {
3016 segments: iter::once(Ident::with_dummy_span(kw::PathRoot))
3017 .chain(path_str.split("::").skip(1).map(Ident::from_str))
3018 .map(|i| self.new_ast_path_segment(i))
3026 .map(Ident::from_str)
3027 .map(|i| self.new_ast_path_segment(i))
3031 let module = self.get_module(module_id);
3032 let parent_scope = &ParentScope::module(module);
3033 let res = self.resolve_ast_path(&path, ns, parent_scope).map_err(|_| ())?;
3037 // Resolve a path passed from rustdoc or HIR lowering.
3038 fn resolve_ast_path(
3042 parent_scope: &ParentScope<'a>,
3043 ) -> Result<Res, (Span, ResolutionError<'a>)> {
3044 match self.resolve_path(
3045 &Segment::from_path(path),
3052 PathResult::Module(ModuleOrUniformRoot::Module(module)) => Ok(module.res().unwrap()),
3053 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 => {
3054 Ok(path_res.base_res())
3056 PathResult::NonModule(..) => Err((
3058 ResolutionError::FailedToResolve {
3059 label: String::from("type-relative paths are not supported in this context"),
3063 PathResult::Module(..) | PathResult::Indeterminate => unreachable!(),
3064 PathResult::Failed { span, label, suggestion, .. } => {
3065 Err((span, ResolutionError::FailedToResolve { label, suggestion }))
3070 fn new_ast_path_segment(&mut self, ident: Ident) -> ast::PathSegment {
3071 let mut seg = ast::PathSegment::from_ident(ident);
3072 seg.id = self.next_node_id();
3077 pub fn graph_root(&self) -> Module<'a> {
3082 pub fn all_macros(&self) -> &FxHashMap<Symbol, Res> {
3086 /// Retrieves the span of the given `DefId` if `DefId` is in the local crate.
3088 pub fn opt_span(&self, def_id: DefId) -> Option<Span> {
3089 if let Some(def_id) = def_id.as_local() { Some(self.def_id_to_span[def_id]) } else { None }
3093 fn names_to_string(names: &[Symbol]) -> String {
3094 let mut result = String::new();
3095 for (i, name) in names.iter().filter(|name| **name != kw::PathRoot).enumerate() {
3097 result.push_str("::");
3099 if Ident::with_dummy_span(*name).is_raw_guess() {
3100 result.push_str("r#");
3102 result.push_str(&name.as_str());
3107 fn path_names_to_string(path: &Path) -> String {
3108 names_to_string(&path.segments.iter().map(|seg| seg.ident.name).collect::<Vec<_>>())
3111 /// A somewhat inefficient routine to obtain the name of a module.
3112 fn module_to_string(module: Module<'_>) -> Option<String> {
3113 let mut names = Vec::new();
3115 fn collect_mod(names: &mut Vec<Symbol>, module: Module<'_>) {
3116 if let ModuleKind::Def(.., name) = module.kind {
3117 if let Some(parent) = module.parent {
3119 collect_mod(names, parent);
3122 names.push(Symbol::intern("<opaque>"));
3123 collect_mod(names, module.parent.unwrap());
3126 collect_mod(&mut names, module);
3128 if names.is_empty() {
3132 Some(names_to_string(&names))
3135 #[derive(Copy, Clone, Debug)]
3137 /// Do not issue the lint.
3140 /// This lint applies to some arbitrary path; e.g., `impl ::foo::Bar`.
3141 /// In this case, we can take the span of that path.
3144 /// This lint comes from a `use` statement. In this case, what we
3145 /// care about really is the *root* `use` statement; e.g., if we
3146 /// have nested things like `use a::{b, c}`, we care about the
3148 UsePath { root_id: NodeId, root_span: Span },
3150 /// This is the "trait item" from a fully qualified path. For example,
3151 /// we might be resolving `X::Y::Z` from a path like `<T as X::Y>::Z`.
3152 /// The `path_span` is the span of the to the trait itself (`X::Y`).
3153 QPathTrait { qpath_id: NodeId, qpath_span: Span },
3157 fn node_id(&self) -> Option<NodeId> {
3159 CrateLint::No => None,
3160 CrateLint::SimplePath(id)
3161 | CrateLint::UsePath { root_id: id, .. }
3162 | CrateLint::QPathTrait { qpath_id: id, .. } => Some(id),
3167 pub fn provide(providers: &mut Providers) {
3168 late::lifetimes::provide(providers);