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::node_id::NodeMap;
24 use rustc_ast::unwrap_or;
25 use rustc_ast::visit::{self, Visitor};
26 use rustc_ast::{self as ast, FloatTy, IntTy, NodeId, UintTy};
27 use rustc_ast::{Crate, CRATE_NODE_ID};
28 use rustc_ast::{ItemKind, Path};
29 use rustc_ast_lowering::ResolverAstLowering;
30 use rustc_ast_pretty::pprust;
31 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
32 use rustc_data_structures::ptr_key::PtrKey;
33 use rustc_data_structures::sync::Lrc;
34 use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder};
35 use rustc_expand::base::SyntaxExtension;
36 use rustc_hir::def::Namespace::*;
37 use rustc_hir::def::{self, CtorOf, DefKind, NonMacroAttrKind, PartialRes};
38 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId, CRATE_DEF_INDEX};
39 use rustc_hir::definitions::{DefKey, DefPathData, Definitions};
40 use rustc_hir::PrimTy::{self, Bool, Char, Float, Int, Str, Uint};
41 use rustc_hir::TraitCandidate;
42 use rustc_index::vec::IndexVec;
43 use rustc_metadata::creader::{CStore, CrateLoader};
44 use rustc_middle::hir::exports::ExportMap;
45 use rustc_middle::middle::cstore::{CrateStore, MetadataLoaderDyn};
46 use rustc_middle::ty::query::Providers;
47 use rustc_middle::ty::{self, DefIdTree, ResolverOutputs};
48 use rustc_middle::{bug, span_bug};
49 use rustc_session::lint;
50 use rustc_session::lint::{BuiltinLintDiagnostics, LintBuffer};
51 use rustc_session::Session;
52 use rustc_span::hygiene::{ExpnId, ExpnKind, MacroKind, SyntaxContext, Transparency};
53 use rustc_span::source_map::Spanned;
54 use rustc_span::symbol::{kw, sym, Ident, Symbol};
55 use rustc_span::{Span, DUMMY_SP};
57 use smallvec::{smallvec, SmallVec};
58 use std::cell::{Cell, RefCell};
59 use std::collections::BTreeSet;
60 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 ParamInTyOfConstParam(Symbol),
219 /// constant values inside of type parameter defaults must not depend on generic parameters.
220 ParamInAnonConstInTyDefault(Symbol),
221 /// generic parameters must not be used inside of non trivial constant values.
223 /// This error is only emitted when using `min_const_generics`.
224 ParamInNonTrivialAnonConst(Symbol),
225 /// Error E0735: type parameters with a default cannot use `Self`
226 SelfInTyParamDefault,
227 /// Error E0767: use of unreachable label
228 UnreachableLabel { name: Symbol, definition_span: Span, suggestion: Option<LabelSuggestion> },
231 enum VisResolutionError<'a> {
232 Relative2018(Span, &'a ast::Path),
234 FailedToResolve(Span, String, Option<Suggestion>),
235 ExpectedFound(Span, String, Res),
240 /// A minimal representation of a path segment. We use this in resolve because we synthesize 'path
241 /// segments' which don't have the rest of an AST or HIR `PathSegment`.
242 #[derive(Clone, Copy, Debug)]
246 /// Signals whether this `PathSegment` has generic arguments. Used to avoid providing
247 /// nonsensical suggestions.
248 has_generic_args: bool,
252 fn from_path(path: &Path) -> Vec<Segment> {
253 path.segments.iter().map(|s| s.into()).collect()
256 fn from_ident(ident: Ident) -> Segment {
257 Segment { ident, id: None, has_generic_args: false }
260 fn names_to_string(segments: &[Segment]) -> String {
261 names_to_string(&segments.iter().map(|seg| seg.ident.name).collect::<Vec<_>>())
265 impl<'a> From<&'a ast::PathSegment> for Segment {
266 fn from(seg: &'a ast::PathSegment) -> Segment {
267 Segment { ident: seg.ident, id: Some(seg.id), has_generic_args: seg.args.is_some() }
271 struct UsePlacementFinder {
272 target_module: NodeId,
277 impl UsePlacementFinder {
278 fn check(krate: &Crate, target_module: NodeId) -> (Option<Span>, bool) {
279 let mut finder = UsePlacementFinder { target_module, span: None, found_use: false };
280 visit::walk_crate(&mut finder, krate);
281 (finder.span, finder.found_use)
285 impl<'tcx> Visitor<'tcx> for UsePlacementFinder {
288 module: &'tcx ast::Mod,
290 _: &[ast::Attribute],
293 if self.span.is_some() {
296 if node_id != self.target_module {
297 visit::walk_mod(self, module);
300 // find a use statement
301 for item in &module.items {
303 ItemKind::Use(..) => {
304 // don't suggest placing a use before the prelude
305 // import or other generated ones
306 if !item.span.from_expansion() {
307 self.span = Some(item.span.shrink_to_lo());
308 self.found_use = true;
312 // don't place use before extern crate
313 ItemKind::ExternCrate(_) => {}
314 // but place them before the first other item
316 if self.span.map_or(true, |span| item.span < span) {
317 if !item.span.from_expansion() {
318 // don't insert between attributes and an item
319 if item.attrs.is_empty() {
320 self.span = Some(item.span.shrink_to_lo());
322 // find the first attribute on the item
323 for attr in &item.attrs {
324 if self.span.map_or(true, |span| attr.span < span) {
325 self.span = Some(attr.span.shrink_to_lo());
337 /// An intermediate resolution result.
339 /// This refers to the thing referred by a name. The difference between `Res` and `Item` is that
340 /// items are visible in their whole block, while `Res`es only from the place they are defined
343 enum LexicalScopeBinding<'a> {
344 Item(&'a NameBinding<'a>),
348 impl<'a> LexicalScopeBinding<'a> {
349 fn res(self) -> Res {
351 LexicalScopeBinding::Item(binding) => binding.res(),
352 LexicalScopeBinding::Res(res) => res,
357 #[derive(Copy, Clone, Debug)]
358 enum ModuleOrUniformRoot<'a> {
362 /// Virtual module that denotes resolution in crate root with fallback to extern prelude.
363 CrateRootAndExternPrelude,
365 /// Virtual module that denotes resolution in extern prelude.
366 /// Used for paths starting with `::` on 2018 edition.
369 /// Virtual module that denotes resolution in current scope.
370 /// Used only for resolving single-segment imports. The reason it exists is that import paths
371 /// are always split into two parts, the first of which should be some kind of module.
375 impl ModuleOrUniformRoot<'_> {
376 fn same_def(lhs: Self, rhs: Self) -> bool {
378 (ModuleOrUniformRoot::Module(lhs), ModuleOrUniformRoot::Module(rhs)) => {
379 lhs.def_id() == rhs.def_id()
382 ModuleOrUniformRoot::CrateRootAndExternPrelude,
383 ModuleOrUniformRoot::CrateRootAndExternPrelude,
385 | (ModuleOrUniformRoot::ExternPrelude, ModuleOrUniformRoot::ExternPrelude)
386 | (ModuleOrUniformRoot::CurrentScope, ModuleOrUniformRoot::CurrentScope) => true,
392 #[derive(Clone, Debug)]
393 enum PathResult<'a> {
394 Module(ModuleOrUniformRoot<'a>),
395 NonModule(PartialRes),
400 suggestion: Option<Suggestion>,
401 is_error_from_last_segment: bool,
406 /// An anonymous module; e.g., just a block.
411 /// { // This is an anonymous module
412 /// f(); // This resolves to (2) as we are inside the block.
415 /// f(); // Resolves to (1)
419 /// Any module with a name.
423 /// * A normal module ‒ either `mod from_file;` or `mod from_block { }`.
424 /// * A trait or an enum (it implicitly contains associated types, methods and variant
426 Def(DefKind, DefId, Symbol),
430 /// Get name of the module.
431 pub fn name(&self) -> Option<Symbol> {
433 ModuleKind::Block(..) => None,
434 ModuleKind::Def(.., name) => Some(*name),
439 /// A key that identifies a binding in a given `Module`.
441 /// Multiple bindings in the same module can have the same key (in a valid
442 /// program) if all but one of them come from glob imports.
443 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
445 /// The identifier for the binding, aways the `normalize_to_macros_2_0` version of the
449 /// 0 if ident is not `_`, otherwise a value that's unique to the specific
450 /// `_` in the expanded AST that introduced this binding.
454 type Resolutions<'a> = RefCell<FxIndexMap<BindingKey, &'a RefCell<NameResolution<'a>>>>;
456 /// One node in the tree of modules.
457 pub struct ModuleData<'a> {
458 parent: Option<Module<'a>>,
461 // The def id of the closest normal module (`mod`) ancestor (including this module).
462 normal_ancestor_id: DefId,
464 // Mapping between names and their (possibly in-progress) resolutions in this module.
465 // Resolutions in modules from other crates are not populated until accessed.
466 lazy_resolutions: Resolutions<'a>,
467 // True if this is a module from other crate that needs to be populated on access.
468 populate_on_access: Cell<bool>,
470 // Macro invocations that can expand into items in this module.
471 unexpanded_invocations: RefCell<FxHashSet<ExpnId>>,
473 no_implicit_prelude: bool,
475 glob_importers: RefCell<Vec<&'a Import<'a>>>,
476 globs: RefCell<Vec<&'a Import<'a>>>,
478 // Used to memoize the traits in this module for faster searches through all traits in scope.
479 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
481 /// Span of the module itself. Used for error reporting.
487 type Module<'a> = &'a ModuleData<'a>;
489 impl<'a> ModuleData<'a> {
491 parent: Option<Module<'a>>,
493 normal_ancestor_id: DefId,
501 lazy_resolutions: Default::default(),
502 populate_on_access: Cell::new(!normal_ancestor_id.is_local()),
503 unexpanded_invocations: Default::default(),
504 no_implicit_prelude: false,
505 glob_importers: RefCell::new(Vec::new()),
506 globs: RefCell::new(Vec::new()),
507 traits: RefCell::new(None),
513 fn for_each_child<R, F>(&'a self, resolver: &mut R, mut f: F)
515 R: AsMut<Resolver<'a>>,
516 F: FnMut(&mut R, Ident, Namespace, &'a NameBinding<'a>),
518 for (key, name_resolution) in resolver.as_mut().resolutions(self).borrow().iter() {
519 if let Some(binding) = name_resolution.borrow().binding {
520 f(resolver, key.ident, key.ns, binding);
525 /// This modifies `self` in place. The traits will be stored in `self.traits`.
526 fn ensure_traits<R>(&'a self, resolver: &mut R)
528 R: AsMut<Resolver<'a>>,
530 let mut traits = self.traits.borrow_mut();
531 if traits.is_none() {
532 let mut collected_traits = Vec::new();
533 self.for_each_child(resolver, |_, name, ns, binding| {
537 match binding.res() {
538 Res::Def(DefKind::Trait | DefKind::TraitAlias, _) => {
539 collected_traits.push((name, binding))
544 *traits = Some(collected_traits.into_boxed_slice());
548 fn res(&self) -> Option<Res> {
550 ModuleKind::Def(kind, def_id, _) => Some(Res::Def(kind, def_id)),
555 fn def_id(&self) -> Option<DefId> {
557 ModuleKind::Def(_, def_id, _) => Some(def_id),
562 // `self` resolves to the first module ancestor that `is_normal`.
563 fn is_normal(&self) -> bool {
565 ModuleKind::Def(DefKind::Mod, _, _) => true,
570 fn is_trait(&self) -> bool {
572 ModuleKind::Def(DefKind::Trait, _, _) => true,
577 fn nearest_item_scope(&'a self) -> Module<'a> {
579 ModuleKind::Def(DefKind::Enum | DefKind::Trait, ..) => {
580 self.parent.expect("enum or trait module without a parent")
586 fn is_ancestor_of(&self, mut other: &Self) -> bool {
587 while !ptr::eq(self, other) {
588 if let Some(parent) = other.parent {
598 impl<'a> fmt::Debug for ModuleData<'a> {
599 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
600 write!(f, "{:?}", self.res())
604 /// Records a possibly-private value, type, or module definition.
605 #[derive(Clone, Debug)]
606 pub struct NameBinding<'a> {
607 kind: NameBindingKind<'a>,
608 ambiguity: Option<(&'a NameBinding<'a>, AmbiguityKind)>,
614 pub trait ToNameBinding<'a> {
615 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
618 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
619 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
624 #[derive(Clone, Debug)]
625 enum NameBindingKind<'a> {
626 Res(Res, /* is_macro_export */ bool),
628 Import { binding: &'a NameBinding<'a>, import: &'a Import<'a>, used: Cell<bool> },
631 impl<'a> NameBindingKind<'a> {
632 /// Is this a name binding of a import?
633 fn is_import(&self) -> bool {
635 NameBindingKind::Import { .. } => true,
641 struct PrivacyError<'a> {
643 binding: &'a NameBinding<'a>,
647 struct UseError<'a> {
648 err: DiagnosticBuilder<'a>,
649 /// Candidates which user could `use` to access the missing type.
650 candidates: Vec<ImportSuggestion>,
651 /// The `DefId` of the module to place the use-statements in.
653 /// Whether the diagnostic should say "instead" (as in `consider importing ... instead`).
655 /// Extra free-form suggestion.
656 suggestion: Option<(Span, &'static str, String, Applicability)>,
659 #[derive(Clone, Copy, PartialEq, Debug)]
664 MacroRulesVsModularized,
672 fn descr(self) -> &'static str {
674 AmbiguityKind::Import => "name vs any other name during import resolution",
675 AmbiguityKind::BuiltinAttr => "built-in attribute vs any other name",
676 AmbiguityKind::DeriveHelper => "derive helper attribute vs any other name",
677 AmbiguityKind::MacroRulesVsModularized => {
678 "`macro_rules` vs non-`macro_rules` from other module"
680 AmbiguityKind::GlobVsOuter => {
681 "glob import vs any other name from outer scope during import/macro resolution"
683 AmbiguityKind::GlobVsGlob => "glob import vs glob import in the same module",
684 AmbiguityKind::GlobVsExpanded => {
685 "glob import vs macro-expanded name in the same \
686 module during import/macro resolution"
688 AmbiguityKind::MoreExpandedVsOuter => {
689 "macro-expanded name vs less macro-expanded name \
690 from outer scope during import/macro resolution"
696 /// Miscellaneous bits of metadata for better ambiguity error reporting.
697 #[derive(Clone, Copy, PartialEq)]
698 enum AmbiguityErrorMisc {
705 struct AmbiguityError<'a> {
708 b1: &'a NameBinding<'a>,
709 b2: &'a NameBinding<'a>,
710 misc1: AmbiguityErrorMisc,
711 misc2: AmbiguityErrorMisc,
714 impl<'a> NameBinding<'a> {
715 fn module(&self) -> Option<Module<'a>> {
717 NameBindingKind::Module(module) => Some(module),
718 NameBindingKind::Import { binding, .. } => binding.module(),
723 fn res(&self) -> Res {
725 NameBindingKind::Res(res, _) => res,
726 NameBindingKind::Module(module) => module.res().unwrap(),
727 NameBindingKind::Import { binding, .. } => binding.res(),
731 fn is_ambiguity(&self) -> bool {
732 self.ambiguity.is_some()
734 NameBindingKind::Import { binding, .. } => binding.is_ambiguity(),
739 fn is_possibly_imported_variant(&self) -> bool {
741 NameBindingKind::Import { binding, .. } => binding.is_possibly_imported_variant(),
742 _ => self.is_variant(),
746 // We sometimes need to treat variants as `pub` for backwards compatibility.
747 fn pseudo_vis(&self) -> ty::Visibility {
748 if self.is_variant() && self.res().def_id().is_local() {
749 ty::Visibility::Public
755 fn is_variant(&self) -> bool {
757 NameBindingKind::Res(
758 Res::Def(DefKind::Variant | DefKind::Ctor(CtorOf::Variant, ..), _),
765 fn is_extern_crate(&self) -> bool {
767 NameBindingKind::Import {
768 import: &Import { kind: ImportKind::ExternCrate { .. }, .. },
771 NameBindingKind::Module(&ModuleData {
772 kind: ModuleKind::Def(DefKind::Mod, def_id, _),
774 }) => def_id.index == CRATE_DEF_INDEX,
779 fn is_import(&self) -> bool {
781 NameBindingKind::Import { .. } => true,
786 fn is_glob_import(&self) -> bool {
788 NameBindingKind::Import { import, .. } => import.is_glob(),
793 fn is_importable(&self) -> bool {
795 Res::Def(DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy, _) => false,
800 fn is_macro_def(&self) -> bool {
802 NameBindingKind::Res(Res::Def(DefKind::Macro(..), _), _) => true,
807 fn macro_kind(&self) -> Option<MacroKind> {
808 self.res().macro_kind()
811 // Suppose that we resolved macro invocation with `invoc_parent_expansion` to binding `binding`
812 // at some expansion round `max(invoc, binding)` when they both emerged from macros.
813 // Then this function returns `true` if `self` may emerge from a macro *after* that
814 // in some later round and screw up our previously found resolution.
815 // See more detailed explanation in
816 // https://github.com/rust-lang/rust/pull/53778#issuecomment-419224049
817 fn may_appear_after(&self, invoc_parent_expansion: ExpnId, binding: &NameBinding<'_>) -> bool {
818 // self > max(invoc, binding) => !(self <= invoc || self <= binding)
819 // Expansions are partially ordered, so "may appear after" is an inversion of
820 // "certainly appears before or simultaneously" and includes unordered cases.
821 let self_parent_expansion = self.expansion;
822 let other_parent_expansion = binding.expansion;
823 let certainly_before_other_or_simultaneously =
824 other_parent_expansion.is_descendant_of(self_parent_expansion);
825 let certainly_before_invoc_or_simultaneously =
826 invoc_parent_expansion.is_descendant_of(self_parent_expansion);
827 !(certainly_before_other_or_simultaneously || certainly_before_invoc_or_simultaneously)
831 /// Interns the names of the primitive types.
833 /// All other types are defined somewhere and possibly imported, but the primitive ones need
834 /// special handling, since they have no place of origin.
835 struct PrimitiveTypeTable {
836 primitive_types: FxHashMap<Symbol, PrimTy>,
839 impl PrimitiveTypeTable {
840 fn new() -> PrimitiveTypeTable {
841 let mut table = FxHashMap::default();
843 table.insert(sym::bool, Bool);
844 table.insert(sym::char, Char);
845 table.insert(sym::f32, Float(FloatTy::F32));
846 table.insert(sym::f64, Float(FloatTy::F64));
847 table.insert(sym::isize, Int(IntTy::Isize));
848 table.insert(sym::i8, Int(IntTy::I8));
849 table.insert(sym::i16, Int(IntTy::I16));
850 table.insert(sym::i32, Int(IntTy::I32));
851 table.insert(sym::i64, Int(IntTy::I64));
852 table.insert(sym::i128, Int(IntTy::I128));
853 table.insert(sym::str, Str);
854 table.insert(sym::usize, Uint(UintTy::Usize));
855 table.insert(sym::u8, Uint(UintTy::U8));
856 table.insert(sym::u16, Uint(UintTy::U16));
857 table.insert(sym::u32, Uint(UintTy::U32));
858 table.insert(sym::u64, Uint(UintTy::U64));
859 table.insert(sym::u128, Uint(UintTy::U128));
860 Self { primitive_types: table }
864 #[derive(Debug, Default, Clone)]
865 pub struct ExternPreludeEntry<'a> {
866 extern_crate_item: Option<&'a NameBinding<'a>>,
867 pub introduced_by_item: bool,
870 /// The main resolver class.
872 /// This is the visitor that walks the whole crate.
873 pub struct Resolver<'a> {
874 session: &'a Session,
876 definitions: Definitions,
878 graph_root: Module<'a>,
880 prelude: Option<Module<'a>>,
881 extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'a>>,
883 /// N.B., this is used only for better diagnostics, not name resolution itself.
884 has_self: FxHashSet<DefId>,
886 /// Names of fields of an item `DefId` accessible with dot syntax.
887 /// Used for hints during error reporting.
888 field_names: FxHashMap<DefId, Vec<Spanned<Symbol>>>,
890 /// All imports known to succeed or fail.
891 determined_imports: Vec<&'a Import<'a>>,
893 /// All non-determined imports.
894 indeterminate_imports: Vec<&'a Import<'a>>,
896 /// FIXME: Refactor things so that these fields are passed through arguments and not resolver.
897 /// We are resolving a last import segment during import validation.
898 last_import_segment: bool,
899 /// This binding should be ignored during in-module resolution, so that we don't get
900 /// "self-confirming" import resolutions during import validation.
901 unusable_binding: Option<&'a NameBinding<'a>>,
903 /// The idents for the primitive types.
904 primitive_type_table: PrimitiveTypeTable,
906 /// Resolutions for nodes that have a single resolution.
907 partial_res_map: NodeMap<PartialRes>,
908 /// Resolutions for import nodes, which have multiple resolutions in different namespaces.
909 import_res_map: NodeMap<PerNS<Option<Res>>>,
910 /// Resolutions for labels (node IDs of their corresponding blocks or loops).
911 label_res_map: NodeMap<NodeId>,
913 /// `CrateNum` resolutions of `extern crate` items.
914 extern_crate_map: FxHashMap<LocalDefId, CrateNum>,
915 export_map: ExportMap<LocalDefId>,
916 trait_map: NodeMap<Vec<TraitCandidate>>,
918 /// A map from nodes to anonymous modules.
919 /// Anonymous modules are pseudo-modules that are implicitly created around items
920 /// contained within blocks.
922 /// For example, if we have this:
930 /// There will be an anonymous module created around `g` with the ID of the
931 /// entry block for `f`.
932 block_map: NodeMap<Module<'a>>,
933 /// A fake module that contains no definition and no prelude. Used so that
934 /// some AST passes can generate identifiers that only resolve to local or
936 empty_module: Module<'a>,
937 module_map: FxHashMap<LocalDefId, Module<'a>>,
938 extern_module_map: FxHashMap<DefId, Module<'a>>,
939 binding_parent_modules: FxHashMap<PtrKey<'a, NameBinding<'a>>, Module<'a>>,
940 underscore_disambiguator: u32,
942 /// Maps glob imports to the names of items actually imported.
943 glob_map: FxHashMap<LocalDefId, FxHashSet<Symbol>>,
945 used_imports: FxHashSet<(NodeId, Namespace)>,
946 maybe_unused_trait_imports: FxHashSet<LocalDefId>,
947 maybe_unused_extern_crates: Vec<(LocalDefId, Span)>,
949 /// Privacy errors are delayed until the end in order to deduplicate them.
950 privacy_errors: Vec<PrivacyError<'a>>,
951 /// Ambiguity errors are delayed for deduplication.
952 ambiguity_errors: Vec<AmbiguityError<'a>>,
953 /// `use` injections are delayed for better placement and deduplication.
954 use_injections: Vec<UseError<'a>>,
955 /// Crate-local macro expanded `macro_export` referred to by a module-relative path.
956 macro_expanded_macro_export_errors: BTreeSet<(Span, Span)>,
958 arenas: &'a ResolverArenas<'a>,
959 dummy_binding: &'a NameBinding<'a>,
961 crate_loader: CrateLoader<'a>,
962 macro_names: FxHashSet<Ident>,
963 builtin_macros: FxHashMap<Symbol, SyntaxExtension>,
964 registered_attrs: FxHashSet<Ident>,
965 registered_tools: FxHashSet<Ident>,
966 macro_use_prelude: FxHashMap<Symbol, &'a NameBinding<'a>>,
967 all_macros: FxHashMap<Symbol, Res>,
968 macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>,
969 dummy_ext_bang: Lrc<SyntaxExtension>,
970 dummy_ext_derive: Lrc<SyntaxExtension>,
971 non_macro_attrs: [Lrc<SyntaxExtension>; 2],
972 local_macro_def_scopes: FxHashMap<LocalDefId, Module<'a>>,
973 ast_transform_scopes: FxHashMap<ExpnId, Module<'a>>,
974 unused_macros: FxHashMap<LocalDefId, (NodeId, Span)>,
975 proc_macro_stubs: FxHashSet<LocalDefId>,
976 /// Traces collected during macro resolution and validated when it's complete.
977 single_segment_macro_resolutions:
978 Vec<(Ident, MacroKind, ParentScope<'a>, Option<&'a NameBinding<'a>>)>,
979 multi_segment_macro_resolutions:
980 Vec<(Vec<Segment>, Span, MacroKind, ParentScope<'a>, Option<Res>)>,
981 builtin_attrs: Vec<(Ident, ParentScope<'a>)>,
982 /// `derive(Copy)` marks items they are applied to so they are treated specially later.
983 /// Derive macros cannot modify the item themselves and have to store the markers in the global
984 /// context, so they attach the markers to derive container IDs using this resolver table.
985 containers_deriving_copy: FxHashSet<ExpnId>,
986 /// Parent scopes in which the macros were invoked.
987 /// FIXME: `derives` are missing in these parent scopes and need to be taken from elsewhere.
988 invocation_parent_scopes: FxHashMap<ExpnId, ParentScope<'a>>,
989 /// `macro_rules` scopes *produced* by expanding the macro invocations,
990 /// include all the `macro_rules` items and other invocations generated by them.
991 output_macro_rules_scopes: FxHashMap<ExpnId, MacroRulesScope<'a>>,
992 /// Helper attributes that are in scope for the given expansion.
993 helper_attrs: FxHashMap<ExpnId, Vec<Ident>>,
995 /// Avoid duplicated errors for "name already defined".
996 name_already_seen: FxHashMap<Symbol, Span>,
998 potentially_unused_imports: Vec<&'a Import<'a>>,
1000 /// Table for mapping struct IDs into struct constructor IDs,
1001 /// it's not used during normal resolution, only for better error reporting.
1002 struct_constructors: DefIdMap<(Res, ty::Visibility)>,
1004 /// Features enabled for this crate.
1005 active_features: FxHashSet<Symbol>,
1007 /// Stores enum visibilities to properly build a reduced graph
1008 /// when visiting the correspondent variants.
1009 variant_vis: DefIdMap<ty::Visibility>,
1011 lint_buffer: LintBuffer,
1013 next_node_id: NodeId,
1015 def_id_to_span: IndexVec<LocalDefId, Span>,
1017 node_id_to_def_id: FxHashMap<ast::NodeId, LocalDefId>,
1018 def_id_to_node_id: IndexVec<LocalDefId, ast::NodeId>,
1020 /// Indices of unnamed struct or variant fields with unresolved attributes.
1021 placeholder_field_indices: FxHashMap<NodeId, usize>,
1022 /// When collecting definitions from an AST fragment produced by a macro invocation `ExpnId`
1023 /// we know what parent node that fragment should be attached to thanks to this table.
1024 invocation_parents: FxHashMap<ExpnId, LocalDefId>,
1026 next_disambiguator: FxHashMap<(LocalDefId, DefPathData), u32>,
1029 /// Nothing really interesting here; it just provides memory for the rest of the crate.
1031 pub struct ResolverArenas<'a> {
1032 modules: TypedArena<ModuleData<'a>>,
1033 local_modules: RefCell<Vec<Module<'a>>>,
1034 name_bindings: TypedArena<NameBinding<'a>>,
1035 imports: TypedArena<Import<'a>>,
1036 name_resolutions: TypedArena<RefCell<NameResolution<'a>>>,
1037 macro_rules_bindings: TypedArena<MacroRulesBinding<'a>>,
1038 ast_paths: TypedArena<ast::Path>,
1041 impl<'a> ResolverArenas<'a> {
1042 fn alloc_module(&'a self, module: ModuleData<'a>) -> Module<'a> {
1043 let module = self.modules.alloc(module);
1044 if module.def_id().map(|def_id| def_id.is_local()).unwrap_or(true) {
1045 self.local_modules.borrow_mut().push(module);
1049 fn local_modules(&'a self) -> std::cell::Ref<'a, Vec<Module<'a>>> {
1050 self.local_modules.borrow()
1052 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1053 self.name_bindings.alloc(name_binding)
1055 fn alloc_import(&'a self, import: Import<'a>) -> &'a Import<'_> {
1056 self.imports.alloc(import)
1058 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1059 self.name_resolutions.alloc(Default::default())
1061 fn alloc_macro_rules_binding(
1063 binding: MacroRulesBinding<'a>,
1064 ) -> &'a MacroRulesBinding<'a> {
1065 self.macro_rules_bindings.alloc(binding)
1067 fn alloc_ast_paths(&'a self, paths: &[ast::Path]) -> &'a [ast::Path] {
1068 self.ast_paths.alloc_from_iter(paths.iter().cloned())
1072 impl<'a> AsMut<Resolver<'a>> for Resolver<'a> {
1073 fn as_mut(&mut self) -> &mut Resolver<'a> {
1078 impl<'a, 'b> DefIdTree for &'a Resolver<'b> {
1079 fn parent(self, id: DefId) -> Option<DefId> {
1080 match id.as_local() {
1081 Some(id) => self.definitions.def_key(id).parent,
1082 None => self.cstore().def_key(id).parent,
1084 .map(|index| DefId { index, ..id })
1088 /// This interface is used through the AST→HIR step, to embed full paths into the HIR. After that
1089 /// the resolver is no longer needed as all the relevant information is inline.
1090 impl ResolverAstLowering for Resolver<'_> {
1091 fn def_key(&mut self, id: DefId) -> DefKey {
1092 if let Some(id) = id.as_local() {
1093 self.definitions().def_key(id)
1095 self.cstore().def_key(id)
1099 fn item_generics_num_lifetimes(&self, def_id: DefId, sess: &Session) -> usize {
1100 self.cstore().item_generics_num_lifetimes(def_id, sess)
1103 fn get_partial_res(&mut self, id: NodeId) -> Option<PartialRes> {
1104 self.partial_res_map.get(&id).cloned()
1107 fn get_import_res(&mut self, id: NodeId) -> PerNS<Option<Res>> {
1108 self.import_res_map.get(&id).cloned().unwrap_or_default()
1111 fn get_label_res(&mut self, id: NodeId) -> Option<NodeId> {
1112 self.label_res_map.get(&id).cloned()
1115 fn definitions(&mut self) -> &mut Definitions {
1116 &mut self.definitions
1119 fn lint_buffer(&mut self) -> &mut LintBuffer {
1120 &mut self.lint_buffer
1123 fn next_node_id(&mut self) -> NodeId {
1127 fn trait_map(&self) -> &NodeMap<Vec<TraitCandidate>> {
1131 fn opt_local_def_id(&self, node: NodeId) -> Option<LocalDefId> {
1132 self.node_id_to_def_id.get(&node).copied()
1135 fn local_def_id(&self, node: NodeId) -> LocalDefId {
1136 self.opt_local_def_id(node).unwrap_or_else(|| panic!("no entry for node id: `{:?}`", node))
1139 /// Adds a definition with a parent definition.
1143 node_id: ast::NodeId,
1149 !self.node_id_to_def_id.contains_key(&node_id),
1150 "adding a def'n for node-id {:?} and data {:?} but a previous def'n exists: {:?}",
1153 self.definitions.def_key(self.node_id_to_def_id[&node_id]),
1156 // Find the next free disambiguator for this key.
1157 let next_disambiguator = &mut self.next_disambiguator;
1158 let next_disambiguator = |parent, data| {
1159 let next_disamb = next_disambiguator.entry((parent, data)).or_insert(0);
1160 let disambiguator = *next_disamb;
1161 *next_disamb = next_disamb.checked_add(1).expect("disambiguator overflow");
1165 let def_id = self.definitions.create_def(parent, data, expn_id, next_disambiguator);
1167 assert_eq!(self.def_id_to_span.push(span), def_id);
1169 // Some things for which we allocate `LocalDefId`s don't correspond to
1170 // anything in the AST, so they don't have a `NodeId`. For these cases
1171 // we don't need a mapping from `NodeId` to `LocalDefId`.
1172 if node_id != ast::DUMMY_NODE_ID {
1173 debug!("create_def: def_id_to_node_id[{:?}] <-> {:?}", def_id, node_id);
1174 self.node_id_to_def_id.insert(node_id, def_id);
1176 assert_eq!(self.def_id_to_node_id.push(node_id), def_id);
1182 impl<'a> Resolver<'a> {
1184 session: &'a Session,
1187 metadata_loader: &'a MetadataLoaderDyn,
1188 arenas: &'a ResolverArenas<'a>,
1190 let root_def_id = DefId::local(CRATE_DEF_INDEX);
1191 let root_module_kind = ModuleKind::Def(DefKind::Mod, root_def_id, kw::Invalid);
1192 let graph_root = arenas.alloc_module(ModuleData {
1193 no_implicit_prelude: session.contains_name(&krate.attrs, sym::no_implicit_prelude),
1194 ..ModuleData::new(None, root_module_kind, root_def_id, ExpnId::root(), krate.span)
1196 let empty_module_kind = ModuleKind::Def(DefKind::Mod, root_def_id, kw::Invalid);
1197 let empty_module = arenas.alloc_module(ModuleData {
1198 no_implicit_prelude: true,
1207 let mut module_map = FxHashMap::default();
1208 module_map.insert(LocalDefId { local_def_index: CRATE_DEF_INDEX }, graph_root);
1210 let definitions = Definitions::new(crate_name, session.local_crate_disambiguator());
1211 let root = definitions.get_root_def();
1213 let mut def_id_to_span = IndexVec::default();
1214 assert_eq!(def_id_to_span.push(rustc_span::DUMMY_SP), root);
1215 let mut def_id_to_node_id = IndexVec::default();
1216 assert_eq!(def_id_to_node_id.push(CRATE_NODE_ID), root);
1217 let mut node_id_to_def_id = FxHashMap::default();
1218 node_id_to_def_id.insert(CRATE_NODE_ID, root);
1220 let mut invocation_parents = FxHashMap::default();
1221 invocation_parents.insert(ExpnId::root(), root);
1223 let mut extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'_>> = session
1227 .filter(|(_, entry)| entry.add_prelude)
1228 .map(|(name, _)| (Ident::from_str(name), Default::default()))
1231 if !session.contains_name(&krate.attrs, sym::no_core) {
1232 extern_prelude.insert(Ident::with_dummy_span(sym::core), Default::default());
1233 if !session.contains_name(&krate.attrs, sym::no_std) {
1234 extern_prelude.insert(Ident::with_dummy_span(sym::std), Default::default());
1235 if session.rust_2018() {
1236 extern_prelude.insert(Ident::with_dummy_span(sym::meta), Default::default());
1241 let (registered_attrs, registered_tools) =
1242 macros::registered_attrs_and_tools(session, &krate.attrs);
1244 let mut invocation_parent_scopes = FxHashMap::default();
1245 invocation_parent_scopes.insert(ExpnId::root(), ParentScope::module(graph_root));
1247 let features = session.features_untracked();
1248 let non_macro_attr =
1249 |mark_used| Lrc::new(SyntaxExtension::non_macro_attr(mark_used, session.edition()));
1256 // The outermost module has def ID 0; this is not reflected in the
1262 has_self: FxHashSet::default(),
1263 field_names: FxHashMap::default(),
1265 determined_imports: Vec::new(),
1266 indeterminate_imports: Vec::new(),
1268 last_import_segment: false,
1269 unusable_binding: None,
1271 primitive_type_table: PrimitiveTypeTable::new(),
1273 partial_res_map: Default::default(),
1274 import_res_map: Default::default(),
1275 label_res_map: Default::default(),
1276 extern_crate_map: Default::default(),
1277 export_map: FxHashMap::default(),
1278 trait_map: Default::default(),
1279 underscore_disambiguator: 0,
1282 block_map: Default::default(),
1283 extern_module_map: FxHashMap::default(),
1284 binding_parent_modules: FxHashMap::default(),
1285 ast_transform_scopes: FxHashMap::default(),
1287 glob_map: Default::default(),
1289 used_imports: FxHashSet::default(),
1290 maybe_unused_trait_imports: Default::default(),
1291 maybe_unused_extern_crates: Vec::new(),
1293 privacy_errors: Vec::new(),
1294 ambiguity_errors: Vec::new(),
1295 use_injections: Vec::new(),
1296 macro_expanded_macro_export_errors: BTreeSet::new(),
1299 dummy_binding: arenas.alloc_name_binding(NameBinding {
1300 kind: NameBindingKind::Res(Res::Err, false),
1302 expansion: ExpnId::root(),
1304 vis: ty::Visibility::Public,
1307 crate_loader: CrateLoader::new(session, metadata_loader, crate_name),
1308 macro_names: FxHashSet::default(),
1309 builtin_macros: Default::default(),
1312 macro_use_prelude: FxHashMap::default(),
1313 all_macros: FxHashMap::default(),
1314 macro_map: FxHashMap::default(),
1315 dummy_ext_bang: Lrc::new(SyntaxExtension::dummy_bang(session.edition())),
1316 dummy_ext_derive: Lrc::new(SyntaxExtension::dummy_derive(session.edition())),
1317 non_macro_attrs: [non_macro_attr(false), non_macro_attr(true)],
1318 invocation_parent_scopes,
1319 output_macro_rules_scopes: Default::default(),
1320 helper_attrs: Default::default(),
1321 local_macro_def_scopes: FxHashMap::default(),
1322 name_already_seen: FxHashMap::default(),
1323 potentially_unused_imports: Vec::new(),
1324 struct_constructors: Default::default(),
1325 unused_macros: Default::default(),
1326 proc_macro_stubs: Default::default(),
1327 single_segment_macro_resolutions: Default::default(),
1328 multi_segment_macro_resolutions: Default::default(),
1329 builtin_attrs: Default::default(),
1330 containers_deriving_copy: Default::default(),
1331 active_features: features
1332 .declared_lib_features
1334 .map(|(feat, ..)| *feat)
1335 .chain(features.declared_lang_features.iter().map(|(feat, ..)| *feat))
1337 variant_vis: Default::default(),
1338 lint_buffer: LintBuffer::default(),
1339 next_node_id: NodeId::from_u32(1),
1343 placeholder_field_indices: Default::default(),
1345 next_disambiguator: Default::default(),
1349 pub fn next_node_id(&mut self) -> NodeId {
1354 .expect("input too large; ran out of NodeIds");
1355 self.next_node_id = ast::NodeId::from_usize(next);
1359 pub fn lint_buffer(&mut self) -> &mut LintBuffer {
1360 &mut self.lint_buffer
1363 pub fn arenas() -> ResolverArenas<'a> {
1367 pub fn into_outputs(self) -> ResolverOutputs {
1368 let definitions = self.definitions;
1369 let extern_crate_map = self.extern_crate_map;
1370 let export_map = self.export_map;
1371 let maybe_unused_trait_imports = self.maybe_unused_trait_imports;
1372 let maybe_unused_extern_crates = self.maybe_unused_extern_crates;
1373 let glob_map = self.glob_map;
1375 definitions: definitions,
1376 cstore: Box::new(self.crate_loader.into_cstore()),
1380 maybe_unused_trait_imports,
1381 maybe_unused_extern_crates,
1382 extern_prelude: self
1385 .map(|(ident, entry)| (ident.name, entry.introduced_by_item))
1390 pub fn clone_outputs(&self) -> ResolverOutputs {
1392 definitions: self.definitions.clone(),
1393 cstore: Box::new(self.cstore().clone()),
1394 extern_crate_map: self.extern_crate_map.clone(),
1395 export_map: self.export_map.clone(),
1396 glob_map: self.glob_map.clone(),
1397 maybe_unused_trait_imports: self.maybe_unused_trait_imports.clone(),
1398 maybe_unused_extern_crates: self.maybe_unused_extern_crates.clone(),
1399 extern_prelude: self
1402 .map(|(ident, entry)| (ident.name, entry.introduced_by_item))
1407 pub fn cstore(&self) -> &CStore {
1408 self.crate_loader.cstore()
1411 fn non_macro_attr(&self, mark_used: bool) -> Lrc<SyntaxExtension> {
1412 self.non_macro_attrs[mark_used as usize].clone()
1415 fn dummy_ext(&self, macro_kind: MacroKind) -> Lrc<SyntaxExtension> {
1417 MacroKind::Bang => self.dummy_ext_bang.clone(),
1418 MacroKind::Derive => self.dummy_ext_derive.clone(),
1419 MacroKind::Attr => self.non_macro_attr(true),
1423 /// Runs the function on each namespace.
1424 fn per_ns<F: FnMut(&mut Self, Namespace)>(&mut self, mut f: F) {
1430 fn is_builtin_macro(&mut self, res: Res) -> bool {
1431 self.get_macro(res).map_or(false, |ext| ext.is_builtin)
1434 fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
1436 match ctxt.outer_expn().expn_data().macro_def_id {
1437 Some(def_id) => return def_id,
1438 None => ctxt.remove_mark(),
1443 /// Entry point to crate resolution.
1444 pub fn resolve_crate(&mut self, krate: &Crate) {
1445 let _prof_timer = self.session.prof.generic_activity("resolve_crate");
1447 ImportResolver { r: self }.finalize_imports();
1448 self.finalize_macro_resolutions();
1450 self.late_resolve_crate(krate);
1452 self.check_unused(krate);
1453 self.report_errors(krate);
1454 self.crate_loader.postprocess(krate);
1457 fn get_traits_in_module_containing_item(
1462 found_traits: &mut Vec<TraitCandidate>,
1463 parent_scope: &ParentScope<'a>,
1465 assert!(ns == TypeNS || ns == ValueNS);
1466 module.ensure_traits(self);
1467 let traits = module.traits.borrow();
1469 for &(trait_name, binding) in traits.as_ref().unwrap().iter() {
1470 // Traits have pseudo-modules that can be used to search for the given ident.
1471 if let Some(module) = binding.module() {
1472 let mut ident = ident;
1473 if ident.span.glob_adjust(module.expansion, binding.span).is_none() {
1477 .resolve_ident_in_module_unadjusted(
1478 ModuleOrUniformRoot::Module(module),
1487 let import_ids = self.find_transitive_imports(&binding.kind, trait_name);
1488 let trait_def_id = module.def_id().unwrap();
1489 found_traits.push(TraitCandidate { def_id: trait_def_id, import_ids });
1491 } else if let Res::Def(DefKind::TraitAlias, _) = binding.res() {
1492 // For now, just treat all trait aliases as possible candidates, since we don't
1493 // know if the ident is somewhere in the transitive bounds.
1494 let import_ids = self.find_transitive_imports(&binding.kind, trait_name);
1495 let trait_def_id = binding.res().def_id();
1496 found_traits.push(TraitCandidate { def_id: trait_def_id, import_ids });
1498 bug!("candidate is not trait or trait alias?")
1503 fn find_transitive_imports(
1505 mut kind: &NameBindingKind<'_>,
1507 ) -> SmallVec<[LocalDefId; 1]> {
1508 let mut import_ids = smallvec![];
1509 while let NameBindingKind::Import { import, binding, .. } = kind {
1510 let id = self.local_def_id(import.id);
1511 self.maybe_unused_trait_imports.insert(id);
1512 self.add_to_glob_map(&import, trait_name);
1513 import_ids.push(id);
1514 kind = &binding.kind;
1523 normal_ancestor_id: DefId,
1527 let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expn_id, span);
1528 self.arenas.alloc_module(module)
1531 fn new_key(&mut self, ident: Ident, ns: Namespace) -> BindingKey {
1532 let ident = ident.normalize_to_macros_2_0();
1533 let disambiguator = if ident.name == kw::Underscore {
1534 self.underscore_disambiguator += 1;
1535 self.underscore_disambiguator
1539 BindingKey { ident, ns, disambiguator }
1542 fn resolutions(&mut self, module: Module<'a>) -> &'a Resolutions<'a> {
1543 if module.populate_on_access.get() {
1544 module.populate_on_access.set(false);
1545 self.build_reduced_graph_external(module);
1547 &module.lazy_resolutions
1554 ) -> &'a RefCell<NameResolution<'a>> {
1556 .resolutions(module)
1559 .or_insert_with(|| self.arenas.alloc_name_resolution())
1566 used_binding: &'a NameBinding<'a>,
1567 is_lexical_scope: bool,
1569 if let Some((b2, kind)) = used_binding.ambiguity {
1570 self.ambiguity_errors.push(AmbiguityError {
1575 misc1: AmbiguityErrorMisc::None,
1576 misc2: AmbiguityErrorMisc::None,
1579 if let NameBindingKind::Import { import, binding, ref used } = used_binding.kind {
1580 // Avoid marking `extern crate` items that refer to a name from extern prelude,
1581 // but not introduce it, as used if they are accessed from lexical scope.
1582 if is_lexical_scope {
1583 if let Some(entry) = self.extern_prelude.get(&ident.normalize_to_macros_2_0()) {
1584 if let Some(crate_item) = entry.extern_crate_item {
1585 if ptr::eq(used_binding, crate_item) && !entry.introduced_by_item {
1592 import.used.set(true);
1593 self.used_imports.insert((import.id, ns));
1594 self.add_to_glob_map(&import, ident);
1595 self.record_use(ident, ns, binding, false);
1600 fn add_to_glob_map(&mut self, import: &Import<'_>, ident: Ident) {
1601 if import.is_glob() {
1602 let def_id = self.local_def_id(import.id);
1603 self.glob_map.entry(def_id).or_default().insert(ident.name);
1607 /// A generic scope visitor.
1608 /// Visits scopes in order to resolve some identifier in them or perform other actions.
1609 /// If the callback returns `Some` result, we stop visiting scopes and return it.
1612 scope_set: ScopeSet,
1613 parent_scope: &ParentScope<'a>,
1615 mut visitor: impl FnMut(&mut Self, Scope<'a>, /*use_prelude*/ bool, Ident) -> Option<T>,
1617 // General principles:
1618 // 1. Not controlled (user-defined) names should have higher priority than controlled names
1619 // built into the language or standard library. This way we can add new names into the
1620 // language or standard library without breaking user code.
1621 // 2. "Closed set" below means new names cannot appear after the current resolution attempt.
1622 // Places to search (in order of decreasing priority):
1624 // 1. FIXME: Ribs (type parameters), there's no necessary infrastructure yet
1625 // (open set, not controlled).
1626 // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
1627 // (open, not controlled).
1628 // 3. Extern prelude (open, the open part is from macro expansions, not controlled).
1629 // 4. Tool modules (closed, controlled right now, but not in the future).
1630 // 5. Standard library prelude (de-facto closed, controlled).
1631 // 6. Language prelude (closed, controlled).
1633 // 1. FIXME: Ribs (local variables), there's no necessary infrastructure yet
1634 // (open set, not controlled).
1635 // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
1636 // (open, not controlled).
1637 // 3. Standard library prelude (de-facto closed, controlled).
1639 // 1-3. Derive helpers (open, not controlled). All ambiguities with other names
1640 // are currently reported as errors. They should be higher in priority than preludes
1641 // and probably even names in modules according to the "general principles" above. They
1642 // also should be subject to restricted shadowing because are effectively produced by
1643 // derives (you need to resolve the derive first to add helpers into scope), but they
1644 // should be available before the derive is expanded for compatibility.
1645 // It's mess in general, so we are being conservative for now.
1646 // 1-3. `macro_rules` (open, not controlled), loop through `macro_rules` scopes. Have higher
1647 // priority than prelude macros, but create ambiguities with macros in modules.
1648 // 1-3. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
1649 // (open, not controlled). Have higher priority than prelude macros, but create
1650 // ambiguities with `macro_rules`.
1651 // 4. `macro_use` prelude (open, the open part is from macro expansions, not controlled).
1652 // 4a. User-defined prelude from macro-use
1653 // (open, the open part is from macro expansions, not controlled).
1654 // 4b. "Standard library prelude" part implemented through `macro-use` (closed, controlled).
1655 // 4c. Standard library prelude (de-facto closed, controlled).
1656 // 6. Language prelude: builtin attributes (closed, controlled).
1658 let rust_2015 = ident.span.rust_2015();
1659 let (ns, macro_kind, is_absolute_path) = match scope_set {
1660 ScopeSet::All(ns, _) => (ns, None, false),
1661 ScopeSet::AbsolutePath(ns) => (ns, None, true),
1662 ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind), false),
1664 // Jump out of trait or enum modules, they do not act as scopes.
1665 let module = parent_scope.module.nearest_item_scope();
1666 let mut scope = match ns {
1667 _ if is_absolute_path => Scope::CrateRoot,
1668 TypeNS | ValueNS => Scope::Module(module),
1669 MacroNS => Scope::DeriveHelpers(parent_scope.expansion),
1671 let mut ident = ident.normalize_to_macros_2_0();
1672 let mut use_prelude = !module.no_implicit_prelude;
1675 let visit = match scope {
1676 // Derive helpers are not in scope when resolving derives in the same container.
1677 Scope::DeriveHelpers(expn_id) => {
1678 !(expn_id == parent_scope.expansion && macro_kind == Some(MacroKind::Derive))
1680 Scope::DeriveHelpersCompat => true,
1681 Scope::MacroRules(..) => true,
1682 Scope::CrateRoot => true,
1683 Scope::Module(..) => true,
1684 Scope::RegisteredAttrs => use_prelude,
1685 Scope::MacroUsePrelude => use_prelude || rust_2015,
1686 Scope::BuiltinAttrs => true,
1687 Scope::ExternPrelude => use_prelude || is_absolute_path,
1688 Scope::ToolPrelude => use_prelude,
1689 Scope::StdLibPrelude => use_prelude || ns == MacroNS,
1690 Scope::BuiltinTypes => true,
1694 if let break_result @ Some(..) = visitor(self, scope, use_prelude, ident) {
1695 return break_result;
1699 scope = match scope {
1700 Scope::DeriveHelpers(expn_id) if expn_id != ExpnId::root() => {
1701 // Derive helpers are not visible to code generated by bang or derive macros.
1702 let expn_data = expn_id.expn_data();
1703 match expn_data.kind {
1705 | ExpnKind::Macro(MacroKind::Bang | MacroKind::Derive, _) => {
1706 Scope::DeriveHelpersCompat
1708 _ => Scope::DeriveHelpers(expn_data.parent),
1711 Scope::DeriveHelpers(..) => Scope::DeriveHelpersCompat,
1712 Scope::DeriveHelpersCompat => Scope::MacroRules(parent_scope.macro_rules),
1713 Scope::MacroRules(macro_rules_scope) => match macro_rules_scope {
1714 MacroRulesScope::Binding(binding) => {
1715 Scope::MacroRules(binding.parent_macro_rules_scope)
1717 MacroRulesScope::Invocation(invoc_id) => Scope::MacroRules(
1718 self.output_macro_rules_scopes
1721 .unwrap_or(self.invocation_parent_scopes[&invoc_id].macro_rules),
1723 MacroRulesScope::Empty => Scope::Module(module),
1725 Scope::CrateRoot => match ns {
1727 ident.span.adjust(ExpnId::root());
1728 Scope::ExternPrelude
1730 ValueNS | MacroNS => break,
1732 Scope::Module(module) => {
1733 use_prelude = !module.no_implicit_prelude;
1734 match self.hygienic_lexical_parent(module, &mut ident.span) {
1735 Some(parent_module) => Scope::Module(parent_module),
1737 ident.span.adjust(ExpnId::root());
1739 TypeNS => Scope::ExternPrelude,
1740 ValueNS => Scope::StdLibPrelude,
1741 MacroNS => Scope::RegisteredAttrs,
1746 Scope::RegisteredAttrs => Scope::MacroUsePrelude,
1747 Scope::MacroUsePrelude => Scope::StdLibPrelude,
1748 Scope::BuiltinAttrs => break, // nowhere else to search
1749 Scope::ExternPrelude if is_absolute_path => break,
1750 Scope::ExternPrelude => Scope::ToolPrelude,
1751 Scope::ToolPrelude => Scope::StdLibPrelude,
1752 Scope::StdLibPrelude => match ns {
1753 TypeNS => Scope::BuiltinTypes,
1754 ValueNS => break, // nowhere else to search
1755 MacroNS => Scope::BuiltinAttrs,
1757 Scope::BuiltinTypes => break, // nowhere else to search
1764 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1765 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1766 /// `ident` in the first scope that defines it (or None if no scopes define it).
1768 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1769 /// the items are defined in the block. For example,
1772 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1775 /// g(); // This resolves to the local variable `g` since it shadows the item.
1779 /// Invariant: This must only be called during main resolution, not during
1780 /// import resolution.
1781 fn resolve_ident_in_lexical_scope(
1785 parent_scope: &ParentScope<'a>,
1786 record_used_id: Option<NodeId>,
1789 ) -> Option<LexicalScopeBinding<'a>> {
1790 assert!(ns == TypeNS || ns == ValueNS);
1791 if ident.name == kw::Invalid {
1792 return Some(LexicalScopeBinding::Res(Res::Err));
1794 let (general_span, normalized_span) = if ident.name == kw::SelfUpper {
1795 // FIXME(jseyfried) improve `Self` hygiene
1796 let empty_span = ident.span.with_ctxt(SyntaxContext::root());
1797 (empty_span, empty_span)
1798 } else if ns == TypeNS {
1799 let normalized_span = ident.span.normalize_to_macros_2_0();
1800 (normalized_span, normalized_span)
1802 (ident.span.normalize_to_macro_rules(), ident.span.normalize_to_macros_2_0())
1804 ident.span = general_span;
1805 let normalized_ident = Ident { span: normalized_span, ..ident };
1807 // Walk backwards up the ribs in scope.
1808 let record_used = record_used_id.is_some();
1809 let mut module = self.graph_root;
1810 for i in (0..ribs.len()).rev() {
1811 debug!("walk rib\n{:?}", ribs[i].bindings);
1812 // Use the rib kind to determine whether we are resolving parameters
1813 // (macro 2.0 hygiene) or local variables (`macro_rules` hygiene).
1814 let rib_ident = if ribs[i].kind.contains_params() { normalized_ident } else { ident };
1815 if let Some(res) = ribs[i].bindings.get(&rib_ident).cloned() {
1816 // The ident resolves to a type parameter or local variable.
1817 return Some(LexicalScopeBinding::Res(self.validate_res_from_ribs(
1827 module = match ribs[i].kind {
1828 ModuleRibKind(module) => module,
1829 MacroDefinition(def) if def == self.macro_def(ident.span.ctxt()) => {
1830 // If an invocation of this macro created `ident`, give up on `ident`
1831 // and switch to `ident`'s source from the macro definition.
1832 ident.span.remove_mark();
1838 let item = self.resolve_ident_in_module_unadjusted(
1839 ModuleOrUniformRoot::Module(module),
1846 if let Ok(binding) = item {
1847 // The ident resolves to an item.
1848 return Some(LexicalScopeBinding::Item(binding));
1852 ModuleKind::Block(..) => {} // We can see through blocks
1857 ident = normalized_ident;
1858 let mut poisoned = None;
1860 let opt_module = if let Some(node_id) = record_used_id {
1861 self.hygienic_lexical_parent_with_compatibility_fallback(
1868 self.hygienic_lexical_parent(module, &mut ident.span)
1870 module = unwrap_or!(opt_module, break);
1871 let adjusted_parent_scope = &ParentScope { module, ..*parent_scope };
1872 let result = self.resolve_ident_in_module_unadjusted(
1873 ModuleOrUniformRoot::Module(module),
1876 adjusted_parent_scope,
1883 if let Some(node_id) = poisoned {
1884 self.lint_buffer.buffer_lint_with_diagnostic(
1885 lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
1888 &format!("cannot find {} `{}` in this scope", ns.descr(), ident),
1889 BuiltinLintDiagnostics::ProcMacroDeriveResolutionFallback(ident.span),
1892 return Some(LexicalScopeBinding::Item(binding));
1894 Err(Determined) => continue,
1895 Err(Undetermined) => {
1896 span_bug!(ident.span, "undetermined resolution during main resolution pass")
1901 if !module.no_implicit_prelude {
1902 ident.span.adjust(ExpnId::root());
1904 if let Some(binding) = self.extern_prelude_get(ident, !record_used) {
1905 return Some(LexicalScopeBinding::Item(binding));
1907 if let Some(ident) = self.registered_tools.get(&ident) {
1909 (Res::ToolMod, ty::Visibility::Public, ident.span, ExpnId::root())
1910 .to_name_binding(self.arenas);
1911 return Some(LexicalScopeBinding::Item(binding));
1914 if let Some(prelude) = self.prelude {
1915 if let Ok(binding) = self.resolve_ident_in_module_unadjusted(
1916 ModuleOrUniformRoot::Module(prelude),
1923 return Some(LexicalScopeBinding::Item(binding));
1929 if let Some(prim_ty) = self.primitive_type_table.primitive_types.get(&ident.name) {
1931 (Res::PrimTy(*prim_ty), ty::Visibility::Public, DUMMY_SP, ExpnId::root())
1932 .to_name_binding(self.arenas);
1933 return Some(LexicalScopeBinding::Item(binding));
1940 fn hygienic_lexical_parent(
1944 ) -> Option<Module<'a>> {
1945 if !module.expansion.outer_expn_is_descendant_of(span.ctxt()) {
1946 return Some(self.macro_def_scope(span.remove_mark()));
1949 if let ModuleKind::Block(..) = module.kind {
1950 return Some(module.parent.unwrap().nearest_item_scope());
1956 fn hygienic_lexical_parent_with_compatibility_fallback(
1961 poisoned: &mut Option<NodeId>,
1962 ) -> Option<Module<'a>> {
1963 if let module @ Some(..) = self.hygienic_lexical_parent(module, span) {
1967 // We need to support the next case under a deprecation warning
1970 // ---- begin: this comes from a proc macro derive
1971 // mod implementation_details {
1972 // // Note that `MyStruct` is not in scope here.
1973 // impl SomeTrait for MyStruct { ... }
1977 // So we have to fall back to the module's parent during lexical resolution in this case.
1978 if let Some(parent) = module.parent {
1979 // Inner module is inside the macro, parent module is outside of the macro.
1980 if module.expansion != parent.expansion
1981 && module.expansion.is_descendant_of(parent.expansion)
1983 // The macro is a proc macro derive
1984 if let Some(def_id) = module.expansion.expn_data().macro_def_id {
1985 if let Some(ext) = self.get_macro_by_def_id(def_id) {
1986 if !ext.is_builtin && ext.macro_kind() == MacroKind::Derive {
1987 if parent.expansion.outer_expn_is_descendant_of(span.ctxt()) {
1988 *poisoned = Some(node_id);
1989 return module.parent;
2000 fn resolve_ident_in_module(
2002 module: ModuleOrUniformRoot<'a>,
2005 parent_scope: &ParentScope<'a>,
2008 ) -> Result<&'a NameBinding<'a>, Determinacy> {
2009 self.resolve_ident_in_module_ext(module, ident, ns, parent_scope, record_used, path_span)
2010 .map_err(|(determinacy, _)| determinacy)
2013 fn resolve_ident_in_module_ext(
2015 module: ModuleOrUniformRoot<'a>,
2018 parent_scope: &ParentScope<'a>,
2021 ) -> Result<&'a NameBinding<'a>, (Determinacy, Weak)> {
2022 let tmp_parent_scope;
2023 let mut adjusted_parent_scope = parent_scope;
2025 ModuleOrUniformRoot::Module(m) => {
2026 if let Some(def) = ident.span.normalize_to_macros_2_0_and_adjust(m.expansion) {
2028 ParentScope { module: self.macro_def_scope(def), ..*parent_scope };
2029 adjusted_parent_scope = &tmp_parent_scope;
2032 ModuleOrUniformRoot::ExternPrelude => {
2033 ident.span.normalize_to_macros_2_0_and_adjust(ExpnId::root());
2035 ModuleOrUniformRoot::CrateRootAndExternPrelude | ModuleOrUniformRoot::CurrentScope => {
2039 self.resolve_ident_in_module_unadjusted_ext(
2043 adjusted_parent_scope,
2050 fn resolve_crate_root(&mut self, ident: Ident) -> Module<'a> {
2051 debug!("resolve_crate_root({:?})", ident);
2052 let mut ctxt = ident.span.ctxt();
2053 let mark = if ident.name == kw::DollarCrate {
2054 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
2055 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
2056 // as described in `SyntaxContext::apply_mark`, so we ignore prepended opaque marks.
2057 // FIXME: This is only a guess and it doesn't work correctly for `macro_rules!`
2058 // definitions actually produced by `macro` and `macro` definitions produced by
2059 // `macro_rules!`, but at least such configurations are not stable yet.
2060 ctxt = ctxt.normalize_to_macro_rules();
2062 "resolve_crate_root: marks={:?}",
2063 ctxt.marks().into_iter().map(|(i, t)| (i.expn_data(), t)).collect::<Vec<_>>()
2065 let mut iter = ctxt.marks().into_iter().rev().peekable();
2066 let mut result = None;
2067 // Find the last opaque mark from the end if it exists.
2068 while let Some(&(mark, transparency)) = iter.peek() {
2069 if transparency == Transparency::Opaque {
2070 result = Some(mark);
2077 "resolve_crate_root: found opaque mark {:?} {:?}",
2079 result.map(|r| r.expn_data())
2081 // Then find the last semi-transparent mark from the end if it exists.
2082 for (mark, transparency) in iter {
2083 if transparency == Transparency::SemiTransparent {
2084 result = Some(mark);
2090 "resolve_crate_root: found semi-transparent mark {:?} {:?}",
2092 result.map(|r| r.expn_data())
2096 debug!("resolve_crate_root: not DollarCrate");
2097 ctxt = ctxt.normalize_to_macros_2_0();
2098 ctxt.adjust(ExpnId::root())
2100 let module = match mark {
2101 Some(def) => self.macro_def_scope(def),
2104 "resolve_crate_root({:?}): found no mark (ident.span = {:?})",
2107 return self.graph_root;
2110 let module = self.get_module(DefId { index: CRATE_DEF_INDEX, ..module.normal_ancestor_id });
2112 "resolve_crate_root({:?}): got module {:?} ({:?}) (ident.span = {:?})",
2121 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
2122 let mut module = self.get_module(module.normal_ancestor_id);
2123 while module.span.ctxt().normalize_to_macros_2_0() != *ctxt {
2124 let parent = module.parent.unwrap_or_else(|| self.macro_def_scope(ctxt.remove_mark()));
2125 module = self.get_module(parent.normal_ancestor_id);
2133 opt_ns: Option<Namespace>, // `None` indicates a module path in import
2134 parent_scope: &ParentScope<'a>,
2137 crate_lint: CrateLint,
2138 ) -> PathResult<'a> {
2139 self.resolve_path_with_ribs(
2150 fn resolve_path_with_ribs(
2153 opt_ns: Option<Namespace>, // `None` indicates a module path in import
2154 parent_scope: &ParentScope<'a>,
2157 crate_lint: CrateLint,
2158 ribs: Option<&PerNS<Vec<Rib<'a>>>>,
2159 ) -> PathResult<'a> {
2160 let mut module = None;
2161 let mut allow_super = true;
2162 let mut second_binding = None;
2165 "resolve_path(path={:?}, opt_ns={:?}, record_used={:?}, \
2166 path_span={:?}, crate_lint={:?})",
2167 path, opt_ns, record_used, path_span, crate_lint,
2170 for (i, &Segment { ident, id, has_generic_args: _ }) in path.iter().enumerate() {
2171 debug!("resolve_path ident {} {:?} {:?}", i, ident, id);
2172 let record_segment_res = |this: &mut Self, res| {
2174 if let Some(id) = id {
2175 if !this.partial_res_map.contains_key(&id) {
2176 assert!(id != ast::DUMMY_NODE_ID, "Trying to resolve dummy id");
2177 this.record_partial_res(id, PartialRes::new(res));
2183 let is_last = i == path.len() - 1;
2184 let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
2185 let name = ident.name;
2187 allow_super &= ns == TypeNS && (name == kw::SelfLower || name == kw::Super);
2190 if allow_super && name == kw::Super {
2191 let mut ctxt = ident.span.ctxt().normalize_to_macros_2_0();
2192 let self_module = match i {
2193 0 => Some(self.resolve_self(&mut ctxt, parent_scope.module)),
2195 Some(ModuleOrUniformRoot::Module(module)) => Some(module),
2199 if let Some(self_module) = self_module {
2200 if let Some(parent) = self_module.parent {
2201 module = Some(ModuleOrUniformRoot::Module(
2202 self.resolve_self(&mut ctxt, parent),
2207 let msg = "there are too many leading `super` keywords".to_string();
2208 return PathResult::Failed {
2212 is_error_from_last_segment: false,
2216 if name == kw::SelfLower {
2217 let mut ctxt = ident.span.ctxt().normalize_to_macros_2_0();
2218 module = Some(ModuleOrUniformRoot::Module(
2219 self.resolve_self(&mut ctxt, parent_scope.module),
2223 if name == kw::PathRoot && ident.span.rust_2018() {
2224 module = Some(ModuleOrUniformRoot::ExternPrelude);
2227 if name == kw::PathRoot && ident.span.rust_2015() && self.session.rust_2018() {
2228 // `::a::b` from 2015 macro on 2018 global edition
2229 module = Some(ModuleOrUniformRoot::CrateRootAndExternPrelude);
2232 if name == kw::PathRoot || name == kw::Crate || name == kw::DollarCrate {
2233 // `::a::b`, `crate::a::b` or `$crate::a::b`
2234 module = Some(ModuleOrUniformRoot::Module(self.resolve_crate_root(ident)));
2240 // Report special messages for path segment keywords in wrong positions.
2241 if ident.is_path_segment_keyword() && i != 0 {
2242 let name_str = if name == kw::PathRoot {
2243 "crate root".to_string()
2245 format!("`{}`", name)
2247 let label = if i == 1 && path[0].ident.name == kw::PathRoot {
2248 format!("global paths cannot start with {}", name_str)
2250 format!("{} in paths can only be used in start position", name_str)
2252 return PathResult::Failed {
2256 is_error_from_last_segment: false,
2260 enum FindBindingResult<'a> {
2261 Binding(Result<&'a NameBinding<'a>, Determinacy>),
2262 PathResult(PathResult<'a>),
2264 let find_binding_in_ns = |this: &mut Self, ns| {
2265 let binding = if let Some(module) = module {
2266 this.resolve_ident_in_module(
2274 } else if ribs.is_none() || opt_ns.is_none() || opt_ns == Some(MacroNS) {
2275 let scopes = ScopeSet::All(ns, opt_ns.is_none());
2276 this.early_resolve_ident_in_lexical_scope(
2285 let record_used_id = if record_used {
2286 crate_lint.node_id().or(Some(CRATE_NODE_ID))
2290 match this.resolve_ident_in_lexical_scope(
2298 // we found a locally-imported or available item/module
2299 Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
2300 // we found a local variable or type param
2301 Some(LexicalScopeBinding::Res(res))
2302 if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) =>
2304 record_segment_res(this, res);
2305 return FindBindingResult::PathResult(PathResult::NonModule(
2306 PartialRes::with_unresolved_segments(res, path.len() - 1),
2309 _ => Err(Determinacy::determined(record_used)),
2312 FindBindingResult::Binding(binding)
2314 let binding = match find_binding_in_ns(self, ns) {
2315 FindBindingResult::PathResult(x) => return x,
2316 FindBindingResult::Binding(binding) => binding,
2321 second_binding = Some(binding);
2323 let res = binding.res();
2324 let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(res);
2325 if let Some(next_module) = binding.module() {
2326 module = Some(ModuleOrUniformRoot::Module(next_module));
2327 record_segment_res(self, res);
2328 } else if res == Res::ToolMod && i + 1 != path.len() {
2329 if binding.is_import() {
2333 "cannot use a tool module through an import",
2335 .span_note(binding.span, "the tool module imported here")
2338 let res = Res::NonMacroAttr(NonMacroAttrKind::Tool);
2339 return PathResult::NonModule(PartialRes::new(res));
2340 } else if res == Res::Err {
2341 return PathResult::NonModule(PartialRes::new(Res::Err));
2342 } else if opt_ns.is_some() && (is_last || maybe_assoc) {
2343 self.lint_if_path_starts_with_module(
2349 return PathResult::NonModule(PartialRes::with_unresolved_segments(
2354 let label = format!(
2355 "`{}` is {} {}, not a module",
2361 return PathResult::Failed {
2365 is_error_from_last_segment: is_last,
2369 Err(Undetermined) => return PathResult::Indeterminate,
2370 Err(Determined) => {
2371 if let Some(ModuleOrUniformRoot::Module(module)) = module {
2372 if opt_ns.is_some() && !module.is_normal() {
2373 return PathResult::NonModule(PartialRes::with_unresolved_segments(
2374 module.res().unwrap(),
2379 let module_res = match module {
2380 Some(ModuleOrUniformRoot::Module(module)) => module.res(),
2383 let (label, suggestion) = if module_res == self.graph_root.res() {
2384 let is_mod = |res| match res {
2385 Res::Def(DefKind::Mod, _) => true,
2388 let mut candidates =
2389 self.lookup_import_candidates(ident, TypeNS, parent_scope, is_mod);
2390 candidates.sort_by_cached_key(|c| {
2391 (c.path.segments.len(), pprust::path_to_string(&c.path))
2393 if let Some(candidate) = candidates.get(0) {
2395 String::from("unresolved import"),
2397 vec![(ident.span, pprust::path_to_string(&candidate.path))],
2398 String::from("a similar path exists"),
2399 Applicability::MaybeIncorrect,
2403 (format!("maybe a missing crate `{}`?", ident), None)
2406 (format!("use of undeclared type or module `{}`", ident), None)
2409 format!("could not find `{}` in `{}`", ident, path[i - 1].ident);
2410 if ns == TypeNS || ns == ValueNS {
2411 let ns_to_try = if ns == TypeNS { ValueNS } else { TypeNS };
2412 if let FindBindingResult::Binding(Ok(binding)) =
2413 find_binding_in_ns(self, ns_to_try)
2415 let mut found = |what| {
2417 "expected {}, found {} `{}` in `{}`",
2424 if binding.module().is_some() {
2427 match binding.res() {
2428 def::Res::<NodeId>::Def(kind, id) => found(kind.descr(id)),
2429 _ => found(ns_to_try.descr()),
2436 return PathResult::Failed {
2440 is_error_from_last_segment: is_last,
2446 self.lint_if_path_starts_with_module(crate_lint, path, path_span, second_binding);
2448 PathResult::Module(match module {
2449 Some(module) => module,
2450 None if path.is_empty() => ModuleOrUniformRoot::CurrentScope,
2451 _ => span_bug!(path_span, "resolve_path: non-empty path `{:?}` has no module", path),
2455 fn lint_if_path_starts_with_module(
2457 crate_lint: CrateLint,
2460 second_binding: Option<&NameBinding<'_>>,
2462 let (diag_id, diag_span) = match crate_lint {
2463 CrateLint::No => return,
2464 CrateLint::SimplePath(id) => (id, path_span),
2465 CrateLint::UsePath { root_id, root_span } => (root_id, root_span),
2466 CrateLint::QPathTrait { qpath_id, qpath_span } => (qpath_id, qpath_span),
2469 let first_name = match path.get(0) {
2470 // In the 2018 edition this lint is a hard error, so nothing to do
2471 Some(seg) if seg.ident.span.rust_2015() && self.session.rust_2015() => seg.ident.name,
2475 // We're only interested in `use` paths which should start with
2476 // `{{root}}` currently.
2477 if first_name != kw::PathRoot {
2482 // If this import looks like `crate::...` it's already good
2483 Some(Segment { ident, .. }) if ident.name == kw::Crate => return,
2484 // Otherwise go below to see if it's an extern crate
2486 // If the path has length one (and it's `PathRoot` most likely)
2487 // then we don't know whether we're gonna be importing a crate or an
2488 // item in our crate. Defer this lint to elsewhere
2492 // If the first element of our path was actually resolved to an
2493 // `ExternCrate` (also used for `crate::...`) then no need to issue a
2494 // warning, this looks all good!
2495 if let Some(binding) = second_binding {
2496 if let NameBindingKind::Import { import, .. } = binding.kind {
2497 // Careful: we still want to rewrite paths from renamed extern crates.
2498 if let ImportKind::ExternCrate { source: None, .. } = import.kind {
2504 let diag = BuiltinLintDiagnostics::AbsPathWithModule(diag_span);
2505 self.lint_buffer.buffer_lint_with_diagnostic(
2506 lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
2509 "absolute paths must start with `self`, `super`, \
2510 `crate`, or an external crate name in the 2018 edition",
2515 // Validate a local resolution (from ribs).
2516 fn validate_res_from_ribs(
2523 all_ribs: &[Rib<'a>],
2525 debug!("validate_res_from_ribs({:?})", res);
2526 let ribs = &all_ribs[rib_index + 1..];
2528 // An invalid forward use of a type parameter from a previous default.
2529 if let ForwardTyParamBanRibKind = all_ribs[rib_index].kind {
2531 let res_error = if rib_ident.name == kw::SelfUpper {
2532 ResolutionError::SelfInTyParamDefault
2534 ResolutionError::ForwardDeclaredTyParam
2536 self.report_error(span, res_error);
2538 assert_eq!(res, Res::Err);
2544 use ResolutionError::*;
2545 let mut res_err = None;
2550 | ClosureOrAsyncRibKind
2552 | MacroDefinition(..)
2553 | ForwardTyParamBanRibKind => {
2554 // Nothing to do. Continue.
2556 ItemRibKind(_) | FnItemRibKind | AssocItemRibKind => {
2557 // This was an attempt to access an upvar inside a
2558 // named function item. This is not allowed, so we
2561 // We don't immediately trigger a resolve error, because
2562 // we want certain other resolution errors (namely those
2563 // emitted for `ConstantItemRibKind` below) to take
2565 res_err = Some(CannotCaptureDynamicEnvironmentInFnItem);
2568 ConstantItemRibKind(_) => {
2569 // Still doesn't deal with upvars
2571 self.report_error(span, AttemptToUseNonConstantValueInConstant);
2575 ConstParamTyRibKind => {
2577 self.report_error(span, ParamInTyOfConstParam(rib_ident.name));
2583 if let Some(res_err) = res_err {
2584 self.report_error(span, res_err);
2588 Res::Def(DefKind::TyParam, _) | Res::SelfTy(..) => {
2589 let mut in_ty_param_default = false;
2591 let has_generic_params = match rib.kind {
2593 | ClosureOrAsyncRibKind
2596 | MacroDefinition(..) => {
2597 // Nothing to do. Continue.
2601 // We only forbid constant items if we are inside of type defaults,
2602 // for example `struct Foo<T, U = [u8; std::mem::size_of::<T>()]>`
2603 ForwardTyParamBanRibKind => {
2604 in_ty_param_default = true;
2607 ConstantItemRibKind(trivial) => {
2608 // HACK(min_const_generics): We currently only allow `N` or `{ N }`.
2609 if !trivial && self.session.features_untracked().min_const_generics {
2613 ResolutionError::ParamInNonTrivialAnonConst(rib_ident.name),
2619 if in_ty_param_default {
2623 ResolutionError::ParamInAnonConstInTyDefault(
2634 // This was an attempt to use a type parameter outside its scope.
2635 ItemRibKind(has_generic_params) => has_generic_params,
2636 FnItemRibKind => HasGenericParams::Yes,
2637 ConstParamTyRibKind => {
2641 ResolutionError::ParamInTyOfConstParam(rib_ident.name),
2651 ResolutionError::GenericParamsFromOuterFunction(
2660 Res::Def(DefKind::ConstParam, _) => {
2661 let mut ribs = ribs.iter().peekable();
2662 if let Some(Rib { kind: FnItemRibKind, .. }) = ribs.peek() {
2663 // When declaring const parameters inside function signatures, the first rib
2664 // is always a `FnItemRibKind`. In this case, we can skip it, to avoid it
2665 // (spuriously) conflicting with the const param.
2669 let mut in_ty_param_default = false;
2671 let has_generic_params = match rib.kind {
2673 | ClosureOrAsyncRibKind
2676 | MacroDefinition(..) => continue,
2678 // We only forbid constant items if we are inside of type defaults,
2679 // for example `struct Foo<T, U = [u8; std::mem::size_of::<T>()]>`
2680 ForwardTyParamBanRibKind => {
2681 in_ty_param_default = true;
2684 ConstantItemRibKind(trivial) => {
2685 // HACK(min_const_generics): We currently only allow `N` or `{ N }`.
2686 if !trivial && self.session.features_untracked().min_const_generics {
2690 ResolutionError::ParamInNonTrivialAnonConst(rib_ident.name),
2696 if in_ty_param_default {
2700 ResolutionError::ParamInAnonConstInTyDefault(
2711 ItemRibKind(has_generic_params) => has_generic_params,
2712 FnItemRibKind => HasGenericParams::Yes,
2713 ConstParamTyRibKind => {
2717 ResolutionError::ParamInTyOfConstParam(rib_ident.name),
2724 // This was an attempt to use a const parameter outside its scope.
2728 ResolutionError::GenericParamsFromOuterFunction(
2742 fn record_partial_res(&mut self, node_id: NodeId, resolution: PartialRes) {
2743 debug!("(recording res) recording {:?} for {}", resolution, node_id);
2744 if let Some(prev_res) = self.partial_res_map.insert(node_id, resolution) {
2745 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
2749 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
2750 vis.is_accessible_from(module.normal_ancestor_id, self)
2753 fn set_binding_parent_module(&mut self, binding: &'a NameBinding<'a>, module: Module<'a>) {
2754 if let Some(old_module) = self.binding_parent_modules.insert(PtrKey(binding), module) {
2755 if !ptr::eq(module, old_module) {
2756 span_bug!(binding.span, "parent module is reset for binding");
2761 fn disambiguate_macro_rules_vs_modularized(
2763 macro_rules: &'a NameBinding<'a>,
2764 modularized: &'a NameBinding<'a>,
2766 // Some non-controversial subset of ambiguities "modularized macro name" vs "macro_rules"
2767 // is disambiguated to mitigate regressions from macro modularization.
2768 // Scoping for `macro_rules` behaves like scoping for `let` at module level, in general.
2770 self.binding_parent_modules.get(&PtrKey(macro_rules)),
2771 self.binding_parent_modules.get(&PtrKey(modularized)),
2773 (Some(macro_rules), Some(modularized)) => {
2774 macro_rules.normal_ancestor_id == modularized.normal_ancestor_id
2775 && modularized.is_ancestor_of(macro_rules)
2781 fn report_errors(&mut self, krate: &Crate) {
2782 self.report_with_use_injections(krate);
2784 for &(span_use, span_def) in &self.macro_expanded_macro_export_errors {
2785 let msg = "macro-expanded `macro_export` macros from the current crate \
2786 cannot be referred to by absolute paths";
2787 self.lint_buffer.buffer_lint_with_diagnostic(
2788 lint::builtin::MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS,
2792 BuiltinLintDiagnostics::MacroExpandedMacroExportsAccessedByAbsolutePaths(span_def),
2796 for ambiguity_error in &self.ambiguity_errors {
2797 self.report_ambiguity_error(ambiguity_error);
2800 let mut reported_spans = FxHashSet::default();
2801 for error in &self.privacy_errors {
2802 if reported_spans.insert(error.dedup_span) {
2803 self.report_privacy_error(error);
2808 fn report_with_use_injections(&mut self, krate: &Crate) {
2809 for UseError { mut err, candidates, def_id, instead, suggestion } in
2810 self.use_injections.drain(..)
2812 let (span, found_use) = if let Some(def_id) = def_id.as_local() {
2813 UsePlacementFinder::check(krate, self.def_id_to_node_id[def_id])
2817 if !candidates.is_empty() {
2818 diagnostics::show_candidates(&mut err, span, &candidates, instead, found_use);
2819 } else if let Some((span, msg, sugg, appl)) = suggestion {
2820 err.span_suggestion(span, msg, sugg, appl);
2826 fn report_conflict<'b>(
2831 new_binding: &NameBinding<'b>,
2832 old_binding: &NameBinding<'b>,
2834 // Error on the second of two conflicting names
2835 if old_binding.span.lo() > new_binding.span.lo() {
2836 return self.report_conflict(parent, ident, ns, old_binding, new_binding);
2839 let container = match parent.kind {
2840 ModuleKind::Def(kind, _, _) => kind.descr(parent.def_id().unwrap()),
2841 ModuleKind::Block(..) => "block",
2844 let old_noun = match old_binding.is_import() {
2846 false => "definition",
2849 let new_participle = match new_binding.is_import() {
2855 (ident.name, self.session.source_map().guess_head_span(new_binding.span));
2857 if let Some(s) = self.name_already_seen.get(&name) {
2863 let old_kind = match (ns, old_binding.module()) {
2864 (ValueNS, _) => "value",
2865 (MacroNS, _) => "macro",
2866 (TypeNS, _) if old_binding.is_extern_crate() => "extern crate",
2867 (TypeNS, Some(module)) if module.is_normal() => "module",
2868 (TypeNS, Some(module)) if module.is_trait() => "trait",
2869 (TypeNS, _) => "type",
2872 let msg = format!("the name `{}` is defined multiple times", name);
2874 let mut err = match (old_binding.is_extern_crate(), new_binding.is_extern_crate()) {
2875 (true, true) => struct_span_err!(self.session, span, E0259, "{}", msg),
2876 (true, _) | (_, true) => match new_binding.is_import() && old_binding.is_import() {
2877 true => struct_span_err!(self.session, span, E0254, "{}", msg),
2878 false => struct_span_err!(self.session, span, E0260, "{}", msg),
2880 _ => match (old_binding.is_import(), new_binding.is_import()) {
2881 (false, false) => struct_span_err!(self.session, span, E0428, "{}", msg),
2882 (true, true) => struct_span_err!(self.session, span, E0252, "{}", msg),
2883 _ => struct_span_err!(self.session, span, E0255, "{}", msg),
2888 "`{}` must be defined only once in the {} namespace of this {}",
2894 err.span_label(span, format!("`{}` re{} here", name, new_participle));
2896 self.session.source_map().guess_head_span(old_binding.span),
2897 format!("previous {} of the {} `{}` here", old_noun, old_kind, name),
2900 // See https://github.com/rust-lang/rust/issues/32354
2901 use NameBindingKind::Import;
2902 let import = match (&new_binding.kind, &old_binding.kind) {
2903 // If there are two imports where one or both have attributes then prefer removing the
2904 // import without attributes.
2905 (Import { import: new, .. }, Import { import: old, .. })
2907 !new_binding.span.is_dummy()
2908 && !old_binding.span.is_dummy()
2909 && (new.has_attributes || old.has_attributes)
2912 if old.has_attributes {
2913 Some((new, new_binding.span, true))
2915 Some((old, old_binding.span, true))
2918 // Otherwise prioritize the new binding.
2919 (Import { import, .. }, other) if !new_binding.span.is_dummy() => {
2920 Some((import, new_binding.span, other.is_import()))
2922 (other, Import { import, .. }) if !old_binding.span.is_dummy() => {
2923 Some((import, old_binding.span, other.is_import()))
2928 // Check if the target of the use for both bindings is the same.
2929 let duplicate = new_binding.res().opt_def_id() == old_binding.res().opt_def_id();
2930 let has_dummy_span = new_binding.span.is_dummy() || old_binding.span.is_dummy();
2932 self.extern_prelude.get(&ident).map(|entry| entry.introduced_by_item).unwrap_or(true);
2933 // Only suggest removing an import if both bindings are to the same def, if both spans
2934 // aren't dummy spans. Further, if both bindings are imports, then the ident must have
2935 // been introduced by a item.
2936 let should_remove_import = duplicate
2938 && ((new_binding.is_extern_crate() || old_binding.is_extern_crate()) || from_item);
2941 Some((import, span, true)) if should_remove_import && import.is_nested() => {
2942 self.add_suggestion_for_duplicate_nested_use(&mut err, import, span)
2944 Some((import, _, true)) if should_remove_import && !import.is_glob() => {
2945 // Simple case - remove the entire import. Due to the above match arm, this can
2946 // only be a single use so just remove it entirely.
2947 err.tool_only_span_suggestion(
2948 import.use_span_with_attributes,
2949 "remove unnecessary import",
2951 Applicability::MaybeIncorrect,
2954 Some((import, span, _)) => {
2955 self.add_suggestion_for_rename_of_use(&mut err, name, import, span)
2961 self.name_already_seen.insert(name, span);
2964 /// This function adds a suggestion to change the binding name of a new import that conflicts
2965 /// with an existing import.
2967 /// ```text,ignore (diagnostic)
2968 /// help: you can use `as` to change the binding name of the import
2970 /// LL | use foo::bar as other_bar;
2971 /// | ^^^^^^^^^^^^^^^^^^^^^
2973 fn add_suggestion_for_rename_of_use(
2975 err: &mut DiagnosticBuilder<'_>,
2977 import: &Import<'_>,
2980 let suggested_name = if name.as_str().chars().next().unwrap().is_uppercase() {
2981 format!("Other{}", name)
2983 format!("other_{}", name)
2986 let mut suggestion = None;
2988 ImportKind::Single { type_ns_only: true, .. } => {
2989 suggestion = Some(format!("self as {}", suggested_name))
2991 ImportKind::Single { source, .. } => {
2993 source.span.hi().0.checked_sub(binding_span.lo().0).map(|pos| pos as usize)
2995 if let Ok(snippet) = self.session.source_map().span_to_snippet(binding_span) {
2996 if pos <= snippet.len() {
2997 suggestion = Some(format!(
3001 if snippet.ends_with(';') { ";" } else { "" }
3007 ImportKind::ExternCrate { source, target, .. } => {
3008 suggestion = Some(format!(
3009 "extern crate {} as {};",
3010 source.unwrap_or(target.name),
3014 _ => unreachable!(),
3017 let rename_msg = "you can use `as` to change the binding name of the import";
3018 if let Some(suggestion) = suggestion {
3019 err.span_suggestion(
3023 Applicability::MaybeIncorrect,
3026 err.span_label(binding_span, rename_msg);
3030 /// This function adds a suggestion to remove a unnecessary binding from an import that is
3031 /// nested. In the following example, this function will be invoked to remove the `a` binding
3032 /// in the second use statement:
3034 /// ```ignore (diagnostic)
3035 /// use issue_52891::a;
3036 /// use issue_52891::{d, a, e};
3039 /// The following suggestion will be added:
3041 /// ```ignore (diagnostic)
3042 /// use issue_52891::{d, a, e};
3043 /// ^-- help: remove unnecessary import
3046 /// If the nested use contains only one import then the suggestion will remove the entire
3049 /// It is expected that the provided import is nested - this isn't checked by the
3050 /// function. If this invariant is not upheld, this function's behaviour will be unexpected
3051 /// as characters expected by span manipulations won't be present.
3052 fn add_suggestion_for_duplicate_nested_use(
3054 err: &mut DiagnosticBuilder<'_>,
3055 import: &Import<'_>,
3058 assert!(import.is_nested());
3059 let message = "remove unnecessary import";
3061 // Two examples will be used to illustrate the span manipulations we're doing:
3063 // - Given `use issue_52891::{d, a, e};` where `a` is a duplicate then `binding_span` is
3064 // `a` and `import.use_span` is `issue_52891::{d, a, e};`.
3065 // - Given `use issue_52891::{d, e, a};` where `a` is a duplicate then `binding_span` is
3066 // `a` and `import.use_span` is `issue_52891::{d, e, a};`.
3068 let (found_closing_brace, span) =
3069 find_span_of_binding_until_next_binding(self.session, binding_span, import.use_span);
3071 // If there was a closing brace then identify the span to remove any trailing commas from
3072 // previous imports.
3073 if found_closing_brace {
3074 if let Some(span) = extend_span_to_previous_binding(self.session, span) {
3075 err.tool_only_span_suggestion(
3079 Applicability::MaybeIncorrect,
3082 // Remove the entire line if we cannot extend the span back, this indicates a
3083 // `issue_52891::{self}` case.
3084 err.span_suggestion(
3085 import.use_span_with_attributes,
3088 Applicability::MaybeIncorrect,
3095 err.span_suggestion(span, message, String::new(), Applicability::MachineApplicable);
3098 fn extern_prelude_get(
3102 ) -> Option<&'a NameBinding<'a>> {
3103 if ident.is_path_segment_keyword() {
3104 // Make sure `self`, `super` etc produce an error when passed to here.
3107 self.extern_prelude.get(&ident.normalize_to_macros_2_0()).cloned().and_then(|entry| {
3108 if let Some(binding) = entry.extern_crate_item {
3109 if !speculative && entry.introduced_by_item {
3110 self.record_use(ident, TypeNS, binding, false);
3114 let crate_id = if !speculative {
3115 self.crate_loader.process_path_extern(ident.name, ident.span)
3117 self.crate_loader.maybe_process_path_extern(ident.name)?
3119 let crate_root = self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
3121 (crate_root, ty::Visibility::Public, DUMMY_SP, ExpnId::root())
3122 .to_name_binding(self.arenas),
3128 /// This is equivalent to `get_traits_in_module_containing_item`, but without filtering by the associated item.
3130 /// This is used by rustdoc for intra-doc links.
3131 pub fn traits_in_scope(&mut self, module_id: DefId) -> Vec<TraitCandidate> {
3132 let module = self.get_module(module_id);
3133 module.ensure_traits(self);
3134 let traits = module.traits.borrow();
3136 |this: &mut Self, &(trait_name, binding): &(Ident, &NameBinding<'_>)| TraitCandidate {
3137 def_id: binding.res().def_id(),
3138 import_ids: this.find_transitive_imports(&binding.kind, trait_name),
3141 let mut candidates: Vec<_> =
3142 traits.as_ref().unwrap().iter().map(|x| to_candidate(self, x)).collect();
3144 if let Some(prelude) = self.prelude {
3145 if !module.no_implicit_prelude {
3146 prelude.ensure_traits(self);
3148 prelude.traits.borrow().as_ref().unwrap().iter().map(|x| to_candidate(self, x)),
3156 /// Rustdoc uses this to resolve things in a recoverable way. `ResolutionError<'a>`
3157 /// isn't something that can be returned because it can't be made to live that long,
3158 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
3159 /// just that an error occurred.
3160 // FIXME(Manishearth): intra-doc links won't get warned of epoch changes.
3161 pub fn resolve_str_path_error(
3167 ) -> Result<(ast::Path, Res), ()> {
3168 let path = if path_str.starts_with("::") {
3171 segments: iter::once(Ident::with_dummy_span(kw::PathRoot))
3172 .chain(path_str.split("::").skip(1).map(Ident::from_str))
3173 .map(|i| self.new_ast_path_segment(i))
3181 .map(Ident::from_str)
3182 .map(|i| self.new_ast_path_segment(i))
3186 let module = self.get_module(module_id);
3187 let parent_scope = &ParentScope::module(module);
3188 let res = self.resolve_ast_path(&path, ns, parent_scope).map_err(|_| ())?;
3192 // Resolve a path passed from rustdoc or HIR lowering.
3193 fn resolve_ast_path(
3197 parent_scope: &ParentScope<'a>,
3198 ) -> Result<Res, (Span, ResolutionError<'a>)> {
3199 match self.resolve_path(
3200 &Segment::from_path(path),
3207 PathResult::Module(ModuleOrUniformRoot::Module(module)) => Ok(module.res().unwrap()),
3208 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 => {
3209 Ok(path_res.base_res())
3211 PathResult::NonModule(..) => Err((
3213 ResolutionError::FailedToResolve {
3214 label: String::from("type-relative paths are not supported in this context"),
3218 PathResult::Module(..) | PathResult::Indeterminate => unreachable!(),
3219 PathResult::Failed { span, label, suggestion, .. } => {
3220 Err((span, ResolutionError::FailedToResolve { label, suggestion }))
3225 fn new_ast_path_segment(&mut self, ident: Ident) -> ast::PathSegment {
3226 let mut seg = ast::PathSegment::from_ident(ident);
3227 seg.id = self.next_node_id();
3232 pub fn graph_root(&self) -> Module<'a> {
3237 pub fn all_macros(&self) -> &FxHashMap<Symbol, Res> {
3241 /// Retrieves the span of the given `DefId` if `DefId` is in the local crate.
3243 pub fn opt_span(&self, def_id: DefId) -> Option<Span> {
3244 if let Some(def_id) = def_id.as_local() { Some(self.def_id_to_span[def_id]) } else { None }
3248 fn names_to_string(names: &[Symbol]) -> String {
3249 let mut result = String::new();
3250 for (i, name) in names.iter().filter(|name| **name != kw::PathRoot).enumerate() {
3252 result.push_str("::");
3254 if Ident::with_dummy_span(*name).is_raw_guess() {
3255 result.push_str("r#");
3257 result.push_str(&name.as_str());
3262 fn path_names_to_string(path: &Path) -> String {
3263 names_to_string(&path.segments.iter().map(|seg| seg.ident.name).collect::<Vec<_>>())
3266 /// A somewhat inefficient routine to obtain the name of a module.
3267 fn module_to_string(module: Module<'_>) -> Option<String> {
3268 let mut names = Vec::new();
3270 fn collect_mod(names: &mut Vec<Symbol>, module: Module<'_>) {
3271 if let ModuleKind::Def(.., name) = module.kind {
3272 if let Some(parent) = module.parent {
3274 collect_mod(names, parent);
3277 names.push(Symbol::intern("<opaque>"));
3278 collect_mod(names, module.parent.unwrap());
3281 collect_mod(&mut names, module);
3283 if names.is_empty() {
3287 Some(names_to_string(&names))
3290 #[derive(Copy, Clone, Debug)]
3292 /// Do not issue the lint.
3295 /// This lint applies to some arbitrary path; e.g., `impl ::foo::Bar`.
3296 /// In this case, we can take the span of that path.
3299 /// This lint comes from a `use` statement. In this case, what we
3300 /// care about really is the *root* `use` statement; e.g., if we
3301 /// have nested things like `use a::{b, c}`, we care about the
3303 UsePath { root_id: NodeId, root_span: Span },
3305 /// This is the "trait item" from a fully qualified path. For example,
3306 /// we might be resolving `X::Y::Z` from a path like `<T as X::Y>::Z`.
3307 /// The `path_span` is the span of the to the trait itself (`X::Y`).
3308 QPathTrait { qpath_id: NodeId, qpath_span: Span },
3312 fn node_id(&self) -> Option<NodeId> {
3314 CrateLint::No => None,
3315 CrateLint::SimplePath(id)
3316 | CrateLint::UsePath { root_id: id, .. }
3317 | CrateLint::QPathTrait { qpath_id: id, .. } => Some(id),
3322 pub fn provide(providers: &mut Providers) {
3323 late::lifetimes::provide(providers);