1 //! This crate is responsible for the part of name resolution that doesn't require type checker.
3 //! Module structure of the crate is built here.
4 //! Paths in macros, imports, expressions, types, patterns are resolved here.
5 //! Label and lifetime names are resolved here as well.
7 //! Type-relative name resolution (methods, fields, associated items) happens in `rustc_typeck`.
9 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
10 #![feature(box_patterns)]
11 #![feature(drain_filter)]
12 #![feature(bool_to_option)]
13 #![feature(crate_visibility_modifier)]
14 #![feature(let_chains)]
16 #![feature(never_type)]
18 #![recursion_limit = "256"]
19 #![allow(rustdoc::private_intra_doc_links)]
20 #![allow(rustc::potential_query_instability)]
25 pub use rustc_hir::def::{Namespace, PerNS};
27 use rustc_arena::{DroplessArena, TypedArena};
28 use rustc_ast::node_id::NodeMap;
29 use rustc_ast::{self as ast, NodeId, CRATE_NODE_ID};
30 use rustc_ast::{Crate, Expr, ExprKind, LitKind, Path};
31 use rustc_ast_lowering::ResolverAstLowering;
32 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
33 use rustc_data_structures::intern::Interned;
34 use rustc_data_structures::sync::Lrc;
35 use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed};
36 use rustc_expand::base::{DeriveResolutions, SyntaxExtension, SyntaxExtensionKind};
37 use rustc_hir::def::Namespace::*;
38 use rustc_hir::def::{self, CtorOf, DefKind, PartialRes};
39 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, DefPathHash, LocalDefId};
40 use rustc_hir::def_id::{CRATE_DEF_ID, CRATE_DEF_INDEX, LOCAL_CRATE};
41 use rustc_hir::definitions::{DefKey, DefPathData, Definitions};
42 use rustc_hir::TraitCandidate;
43 use rustc_index::vec::IndexVec;
44 use rustc_metadata::creader::{CStore, CrateLoader};
45 use rustc_middle::metadata::ModChild;
46 use rustc_middle::middle::privacy::AccessLevels;
47 use rustc_middle::span_bug;
48 use rustc_middle::ty::query::Providers;
49 use rustc_middle::ty::{self, DefIdTree, MainDefinition, RegisteredTools, ResolverOutputs};
50 use rustc_query_system::ich::StableHashingContext;
51 use rustc_session::cstore::{CrateStore, MetadataLoaderDyn};
52 use rustc_session::lint::LintBuffer;
53 use rustc_session::Session;
54 use rustc_span::hygiene::{ExpnId, LocalExpnId, MacroKind, SyntaxContext, Transparency};
55 use rustc_span::source_map::Spanned;
56 use rustc_span::symbol::{kw, sym, Ident, Symbol};
57 use rustc_span::{Span, DUMMY_SP};
59 use smallvec::{smallvec, SmallVec};
60 use std::cell::{Cell, RefCell};
61 use std::collections::BTreeSet;
62 use std::{cmp, fmt, mem, ptr};
65 use diagnostics::{ImportSuggestion, LabelSuggestion, Suggestion};
66 use imports::{Import, ImportKind, ImportResolver, NameResolution};
67 use late::{HasGenericParams, PathSource};
68 use macros::{MacroRulesBinding, MacroRulesScope, MacroRulesScopeRef};
70 use crate::access_levels::AccessLevelsVisitor;
72 type Res = def::Res<NodeId>;
75 mod build_reduced_graph;
89 #[derive(Copy, Clone, PartialEq, Debug)]
90 pub enum Determinacy {
96 fn determined(determined: bool) -> Determinacy {
97 if determined { Determinacy::Determined } else { Determinacy::Undetermined }
101 /// A specific scope in which a name can be looked up.
102 /// This enum is currently used only for early resolution (imports and macros),
103 /// but not for late resolution yet.
104 #[derive(Clone, Copy)]
106 DeriveHelpers(LocalExpnId),
108 MacroRules(MacroRulesScopeRef<'a>),
110 // The node ID is for reporting the `PROC_MACRO_DERIVE_RESOLUTION_FALLBACK`
111 // lint if it should be reported.
112 Module(Module<'a>, Option<NodeId>),
122 /// Names from different contexts may want to visit different subsets of all specific scopes
123 /// with different restrictions when looking up the resolution.
124 /// This enum is currently used only for early resolution (imports and macros),
125 /// but not for late resolution yet.
126 #[derive(Clone, Copy)]
128 /// All scopes with the given namespace.
129 All(Namespace, /*is_import*/ bool),
130 /// Crate root, then extern prelude (used for mixed 2015-2018 mode in macros).
131 AbsolutePath(Namespace),
132 /// All scopes with macro namespace and the given macro kind restriction.
134 /// All scopes with the given namespace, used for partially performing late resolution.
135 /// The node id enables lints and is used for reporting them.
136 Late(Namespace, Module<'a>, Option<NodeId>),
139 /// Everything you need to know about a name's location to resolve it.
140 /// Serves as a starting point for the scope visitor.
141 /// This struct is currently used only for early resolution (imports and macros),
142 /// but not for late resolution yet.
143 #[derive(Clone, Copy, Debug)]
144 pub struct ParentScope<'a> {
146 expansion: LocalExpnId,
147 macro_rules: MacroRulesScopeRef<'a>,
148 derives: &'a [ast::Path],
151 impl<'a> ParentScope<'a> {
152 /// Creates a parent scope with the passed argument used as the module scope component,
153 /// and other scope components set to default empty values.
154 pub fn module(module: Module<'a>, resolver: &Resolver<'a>) -> ParentScope<'a> {
157 expansion: LocalExpnId::ROOT,
158 macro_rules: resolver.arenas.alloc_macro_rules_scope(MacroRulesScope::Empty),
164 #[derive(Copy, Debug, Clone)]
165 enum ImplTraitContext {
167 Universal(LocalDefId),
171 struct BindingError {
173 origin: BTreeSet<Span>,
174 target: BTreeSet<Span>,
178 impl PartialOrd for BindingError {
179 fn partial_cmp(&self, other: &BindingError) -> Option<cmp::Ordering> {
180 Some(self.cmp(other))
184 impl PartialEq for BindingError {
185 fn eq(&self, other: &BindingError) -> bool {
186 self.name == other.name
190 impl Ord for BindingError {
191 fn cmp(&self, other: &BindingError) -> cmp::Ordering {
192 self.name.cmp(&other.name)
196 enum ResolutionError<'a> {
197 /// Error E0401: can't use type or const parameters from outer function.
198 GenericParamsFromOuterFunction(Res, HasGenericParams),
199 /// Error E0403: the name is already used for a type or const parameter in this generic
201 NameAlreadyUsedInParameterList(Symbol, Span),
202 /// Error E0407: method is not a member of trait.
203 MethodNotMemberOfTrait(Ident, &'a str, Option<Symbol>),
204 /// Error E0437: type is not a member of trait.
205 TypeNotMemberOfTrait(Ident, &'a str, Option<Symbol>),
206 /// Error E0438: const is not a member of trait.
207 ConstNotMemberOfTrait(Ident, &'a str, Option<Symbol>),
208 /// Error E0408: variable `{}` is not bound in all patterns.
209 VariableNotBoundInPattern(&'a BindingError),
210 /// Error E0409: variable `{}` is bound in inconsistent ways within the same match arm.
211 VariableBoundWithDifferentMode(Symbol, Span),
212 /// Error E0415: identifier is bound more than once in this parameter list.
213 IdentifierBoundMoreThanOnceInParameterList(Symbol),
214 /// Error E0416: identifier is bound more than once in the same pattern.
215 IdentifierBoundMoreThanOnceInSamePattern(Symbol),
216 /// Error E0426: use of undeclared label.
217 UndeclaredLabel { name: Symbol, suggestion: Option<LabelSuggestion> },
218 /// Error E0429: `self` imports are only allowed within a `{ }` list.
219 SelfImportsOnlyAllowedWithin { root: bool, span_with_rename: Span },
220 /// Error E0430: `self` import can only appear once in the list.
221 SelfImportCanOnlyAppearOnceInTheList,
222 /// Error E0431: `self` import can only appear in an import list with a non-empty prefix.
223 SelfImportOnlyInImportListWithNonEmptyPrefix,
224 /// Error E0433: failed to resolve.
225 FailedToResolve { label: String, suggestion: Option<Suggestion> },
226 /// Error E0434: can't capture dynamic environment in a fn item.
227 CannotCaptureDynamicEnvironmentInFnItem,
228 /// Error E0435: attempt to use a non-constant value in a constant.
229 AttemptToUseNonConstantValueInConstant(
231 /* suggestion */ &'static str,
232 /* current */ &'static str,
234 /// Error E0530: `X` bindings cannot shadow `Y`s.
235 BindingShadowsSomethingUnacceptable {
236 shadowing_binding_descr: &'static str,
238 participle: &'static str,
239 article: &'static str,
240 shadowed_binding_descr: &'static str,
241 shadowed_binding_span: Span,
243 /// Error E0128: generic parameters with a default cannot use forward-declared identifiers.
244 ForwardDeclaredGenericParam,
245 /// ERROR E0770: the type of const parameters must not depend on other generic parameters.
246 ParamInTyOfConstParam(Symbol),
247 /// generic parameters must not be used inside const evaluations.
249 /// This error is only emitted when using `min_const_generics`.
250 ParamInNonTrivialAnonConst { name: Symbol, is_type: bool },
251 /// Error E0735: generic parameters with a default cannot use `Self`
252 SelfInGenericParamDefault,
253 /// Error E0767: use of unreachable label
254 UnreachableLabel { name: Symbol, definition_span: Span, suggestion: Option<LabelSuggestion> },
255 /// Error E0323, E0324, E0325: mismatch between trait item and impl item.
260 trait_item_span: Span,
261 code: rustc_errors::DiagnosticId,
265 enum VisResolutionError<'a> {
266 Relative2018(Span, &'a ast::Path),
268 FailedToResolve(Span, String, Option<Suggestion>),
269 ExpectedFound(Span, String, Res),
274 /// A minimal representation of a path segment. We use this in resolve because we synthesize 'path
275 /// segments' which don't have the rest of an AST or HIR `PathSegment`.
276 #[derive(Clone, Copy, Debug)]
280 /// Signals whether this `PathSegment` has generic arguments. Used to avoid providing
281 /// nonsensical suggestions.
282 has_generic_args: bool,
286 fn from_path(path: &Path) -> Vec<Segment> {
287 path.segments.iter().map(|s| s.into()).collect()
290 fn from_ident(ident: Ident) -> Segment {
291 Segment { ident, id: None, has_generic_args: false }
294 fn names_to_string(segments: &[Segment]) -> String {
295 names_to_string(&segments.iter().map(|seg| seg.ident.name).collect::<Vec<_>>())
299 impl<'a> From<&'a ast::PathSegment> for Segment {
300 fn from(seg: &'a ast::PathSegment) -> Segment {
301 Segment { ident: seg.ident, id: Some(seg.id), has_generic_args: seg.args.is_some() }
305 /// An intermediate resolution result.
307 /// This refers to the thing referred by a name. The difference between `Res` and `Item` is that
308 /// items are visible in their whole block, while `Res`es only from the place they are defined
311 enum LexicalScopeBinding<'a> {
312 Item(&'a NameBinding<'a>),
316 impl<'a> LexicalScopeBinding<'a> {
317 fn res(self) -> Res {
319 LexicalScopeBinding::Item(binding) => binding.res(),
320 LexicalScopeBinding::Res(res) => res,
325 #[derive(Copy, Clone, Debug)]
326 enum ModuleOrUniformRoot<'a> {
330 /// Virtual module that denotes resolution in crate root with fallback to extern prelude.
331 CrateRootAndExternPrelude,
333 /// Virtual module that denotes resolution in extern prelude.
334 /// Used for paths starting with `::` on 2018 edition.
337 /// Virtual module that denotes resolution in current scope.
338 /// Used only for resolving single-segment imports. The reason it exists is that import paths
339 /// are always split into two parts, the first of which should be some kind of module.
343 impl ModuleOrUniformRoot<'_> {
344 fn same_def(lhs: Self, rhs: Self) -> bool {
346 (ModuleOrUniformRoot::Module(lhs), ModuleOrUniformRoot::Module(rhs)) => {
350 ModuleOrUniformRoot::CrateRootAndExternPrelude,
351 ModuleOrUniformRoot::CrateRootAndExternPrelude,
353 | (ModuleOrUniformRoot::ExternPrelude, ModuleOrUniformRoot::ExternPrelude)
354 | (ModuleOrUniformRoot::CurrentScope, ModuleOrUniformRoot::CurrentScope) => true,
360 #[derive(Clone, Debug)]
361 enum PathResult<'a> {
362 Module(ModuleOrUniformRoot<'a>),
363 NonModule(PartialRes),
368 suggestion: Option<Suggestion>,
369 is_error_from_last_segment: bool,
373 impl<'a> PathResult<'a> {
376 is_error_from_last_segment: bool,
378 label_and_suggestion: impl FnOnce() -> (String, Option<Suggestion>),
379 ) -> PathResult<'a> {
380 let (label, suggestion) =
381 if finalize { label_and_suggestion() } else { (String::new(), None) };
382 PathResult::Failed { span, label, suggestion, is_error_from_last_segment }
388 /// An anonymous module; e.g., just a block.
393 /// { // This is an anonymous module
394 /// f(); // This resolves to (2) as we are inside the block.
397 /// f(); // Resolves to (1)
401 /// Any module with a name.
405 /// * A normal module – either `mod from_file;` or `mod from_block { }` –
406 /// or the crate root (which is conceptually a top-level module).
407 /// Note that the crate root's [name][Self::name] will be [`kw::Empty`].
408 /// * A trait or an enum (it implicitly contains associated types, methods and variant
410 Def(DefKind, DefId, Symbol),
414 /// Get name of the module.
415 pub fn name(&self) -> Option<Symbol> {
417 ModuleKind::Block(..) => None,
418 ModuleKind::Def(.., name) => Some(*name),
423 /// A key that identifies a binding in a given `Module`.
425 /// Multiple bindings in the same module can have the same key (in a valid
426 /// program) if all but one of them come from glob imports.
427 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
429 /// The identifier for the binding, always the `normalize_to_macros_2_0` version of the
433 /// 0 if ident is not `_`, otherwise a value that's unique to the specific
434 /// `_` in the expanded AST that introduced this binding.
438 type Resolutions<'a> = RefCell<FxIndexMap<BindingKey, &'a RefCell<NameResolution<'a>>>>;
440 /// One node in the tree of modules.
442 /// Note that a "module" in resolve is broader than a `mod` that you declare in Rust code. It may be one of these:
445 /// * crate root (aka, top-level anonymous module)
448 /// * curly-braced block with statements
450 /// You can use [`ModuleData::kind`] to determine the kind of module this is.
451 pub struct ModuleData<'a> {
452 /// The direct parent module (it may not be a `mod`, however).
453 parent: Option<Module<'a>>,
454 /// What kind of module this is, because this may not be a `mod`.
457 /// Mapping between names and their (possibly in-progress) resolutions in this module.
458 /// Resolutions in modules from other crates are not populated until accessed.
459 lazy_resolutions: Resolutions<'a>,
460 /// True if this is a module from other crate that needs to be populated on access.
461 populate_on_access: Cell<bool>,
463 /// Macro invocations that can expand into items in this module.
464 unexpanded_invocations: RefCell<FxHashSet<LocalExpnId>>,
466 /// Whether `#[no_implicit_prelude]` is active.
467 no_implicit_prelude: bool,
469 glob_importers: RefCell<Vec<&'a Import<'a>>>,
470 globs: RefCell<Vec<&'a Import<'a>>>,
472 /// Used to memoize the traits in this module for faster searches through all traits in scope.
473 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
475 /// Span of the module itself. Used for error reporting.
481 type Module<'a> = &'a ModuleData<'a>;
483 impl<'a> ModuleData<'a> {
485 parent: Option<Module<'a>>,
489 no_implicit_prelude: bool,
491 let is_foreign = match kind {
492 ModuleKind::Def(_, def_id, _) => !def_id.is_local(),
493 ModuleKind::Block(_) => false,
498 lazy_resolutions: Default::default(),
499 populate_on_access: Cell::new(is_foreign),
500 unexpanded_invocations: Default::default(),
502 glob_importers: RefCell::new(Vec::new()),
503 globs: RefCell::new(Vec::new()),
504 traits: RefCell::new(None),
510 fn for_each_child<R, F>(&'a self, resolver: &mut R, mut f: F)
512 R: AsMut<Resolver<'a>>,
513 F: FnMut(&mut R, Ident, Namespace, &'a NameBinding<'a>),
515 for (key, name_resolution) in resolver.as_mut().resolutions(self).borrow().iter() {
516 if let Some(binding) = name_resolution.borrow().binding {
517 f(resolver, key.ident, key.ns, binding);
522 /// This modifies `self` in place. The traits will be stored in `self.traits`.
523 fn ensure_traits<R>(&'a self, resolver: &mut R)
525 R: AsMut<Resolver<'a>>,
527 let mut traits = self.traits.borrow_mut();
528 if traits.is_none() {
529 let mut collected_traits = Vec::new();
530 self.for_each_child(resolver, |_, name, ns, binding| {
534 if let Res::Def(DefKind::Trait | DefKind::TraitAlias, _) = binding.res() {
535 collected_traits.push((name, binding))
538 *traits = Some(collected_traits.into_boxed_slice());
542 fn res(&self) -> Option<Res> {
544 ModuleKind::Def(kind, def_id, _) => Some(Res::Def(kind, def_id)),
549 // Public for rustdoc.
550 pub fn def_id(&self) -> DefId {
551 self.opt_def_id().expect("`ModuleData::def_id` is called on a block module")
554 fn opt_def_id(&self) -> Option<DefId> {
556 ModuleKind::Def(_, def_id, _) => Some(def_id),
561 // `self` resolves to the first module ancestor that `is_normal`.
562 fn is_normal(&self) -> bool {
563 matches!(self.kind, ModuleKind::Def(DefKind::Mod, _, _))
566 fn is_trait(&self) -> bool {
567 matches!(self.kind, ModuleKind::Def(DefKind::Trait, _, _))
570 fn nearest_item_scope(&'a self) -> Module<'a> {
572 ModuleKind::Def(DefKind::Enum | DefKind::Trait, ..) => {
573 self.parent.expect("enum or trait module without a parent")
579 /// The [`DefId`] of the nearest `mod` item ancestor (which may be this module).
580 /// This may be the crate root.
581 fn nearest_parent_mod(&self) -> DefId {
583 ModuleKind::Def(DefKind::Mod, def_id, _) => def_id,
584 _ => self.parent.expect("non-root module without parent").nearest_parent_mod(),
588 fn is_ancestor_of(&self, mut other: &Self) -> bool {
589 while !ptr::eq(self, other) {
590 if let Some(parent) = other.parent {
600 impl<'a> fmt::Debug for ModuleData<'a> {
601 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
602 write!(f, "{:?}", self.res())
606 /// Records a possibly-private value, type, or module definition.
607 #[derive(Clone, Debug)]
608 pub struct NameBinding<'a> {
609 kind: NameBindingKind<'a>,
610 ambiguity: Option<(&'a NameBinding<'a>, AmbiguityKind)>,
611 expansion: LocalExpnId,
616 pub trait ToNameBinding<'a> {
617 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
620 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
621 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
626 #[derive(Clone, Debug)]
627 enum NameBindingKind<'a> {
628 Res(Res, /* is_macro_export */ bool),
630 Import { binding: &'a NameBinding<'a>, import: &'a Import<'a>, used: Cell<bool> },
633 impl<'a> NameBindingKind<'a> {
634 /// Is this a name binding of an import?
635 fn is_import(&self) -> bool {
636 matches!(*self, NameBindingKind::Import { .. })
640 struct PrivacyError<'a> {
642 binding: &'a NameBinding<'a>,
646 struct UseError<'a> {
647 err: DiagnosticBuilder<'a, ErrorGuaranteed>,
648 /// Candidates which user could `use` to access the missing type.
649 candidates: Vec<ImportSuggestion>,
650 /// The `DefId` of the module to place the use-statements in.
652 /// Whether the diagnostic should say "instead" (as in `consider importing ... instead`).
654 /// Extra free-form suggestion.
655 suggestion: Option<(Span, &'static str, String, Applicability)>,
658 #[derive(Clone, Copy, PartialEq, Debug)]
663 MacroRulesVsModularized,
671 fn descr(self) -> &'static str {
673 AmbiguityKind::Import => "multiple potential import sources",
674 AmbiguityKind::BuiltinAttr => "a name conflict with a builtin attribute",
675 AmbiguityKind::DeriveHelper => "a name conflict with a derive helper attribute",
676 AmbiguityKind::MacroRulesVsModularized => {
677 "a conflict between a `macro_rules` name and a non-`macro_rules` name from another module"
679 AmbiguityKind::GlobVsOuter => {
680 "a conflict between a name from a glob import and an outer scope during import or macro resolution"
682 AmbiguityKind::GlobVsGlob => "multiple glob imports of a name in the same module",
683 AmbiguityKind::GlobVsExpanded => {
684 "a conflict between a name from a glob import and a macro-expanded name in the same module during import or macro resolution"
686 AmbiguityKind::MoreExpandedVsOuter => {
687 "a conflict between a macro-expanded name and a less macro-expanded name from outer scope during import or macro resolution"
693 /// Miscellaneous bits of metadata for better ambiguity error reporting.
694 #[derive(Clone, Copy, PartialEq)]
695 enum AmbiguityErrorMisc {
702 struct AmbiguityError<'a> {
705 b1: &'a NameBinding<'a>,
706 b2: &'a NameBinding<'a>,
707 misc1: AmbiguityErrorMisc,
708 misc2: AmbiguityErrorMisc,
711 impl<'a> NameBinding<'a> {
712 fn module(&self) -> Option<Module<'a>> {
714 NameBindingKind::Module(module) => Some(module),
715 NameBindingKind::Import { binding, .. } => binding.module(),
720 fn res(&self) -> Res {
722 NameBindingKind::Res(res, _) => res,
723 NameBindingKind::Module(module) => module.res().unwrap(),
724 NameBindingKind::Import { binding, .. } => binding.res(),
728 fn is_ambiguity(&self) -> bool {
729 self.ambiguity.is_some()
731 NameBindingKind::Import { binding, .. } => binding.is_ambiguity(),
736 fn is_possibly_imported_variant(&self) -> bool {
738 NameBindingKind::Import { binding, .. } => binding.is_possibly_imported_variant(),
739 NameBindingKind::Res(
740 Res::Def(DefKind::Variant | DefKind::Ctor(CtorOf::Variant, ..), _),
743 NameBindingKind::Res(..) | NameBindingKind::Module(..) => false,
747 fn is_extern_crate(&self) -> bool {
749 NameBindingKind::Import {
750 import: &Import { kind: ImportKind::ExternCrate { .. }, .. },
753 NameBindingKind::Module(&ModuleData {
754 kind: ModuleKind::Def(DefKind::Mod, def_id, _),
756 }) => def_id.index == CRATE_DEF_INDEX,
761 fn is_import(&self) -> bool {
762 matches!(self.kind, NameBindingKind::Import { .. })
765 fn is_glob_import(&self) -> bool {
767 NameBindingKind::Import { import, .. } => import.is_glob(),
772 fn is_importable(&self) -> bool {
775 Res::Def(DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy, _)
779 fn macro_kind(&self) -> Option<MacroKind> {
780 self.res().macro_kind()
783 // Suppose that we resolved macro invocation with `invoc_parent_expansion` to binding `binding`
784 // at some expansion round `max(invoc, binding)` when they both emerged from macros.
785 // Then this function returns `true` if `self` may emerge from a macro *after* that
786 // in some later round and screw up our previously found resolution.
787 // See more detailed explanation in
788 // https://github.com/rust-lang/rust/pull/53778#issuecomment-419224049
791 invoc_parent_expansion: LocalExpnId,
792 binding: &NameBinding<'_>,
794 // self > max(invoc, binding) => !(self <= invoc || self <= binding)
795 // Expansions are partially ordered, so "may appear after" is an inversion of
796 // "certainly appears before or simultaneously" and includes unordered cases.
797 let self_parent_expansion = self.expansion;
798 let other_parent_expansion = binding.expansion;
799 let certainly_before_other_or_simultaneously =
800 other_parent_expansion.is_descendant_of(self_parent_expansion);
801 let certainly_before_invoc_or_simultaneously =
802 invoc_parent_expansion.is_descendant_of(self_parent_expansion);
803 !(certainly_before_other_or_simultaneously || certainly_before_invoc_or_simultaneously)
807 #[derive(Debug, Default, Clone)]
808 pub struct ExternPreludeEntry<'a> {
809 extern_crate_item: Option<&'a NameBinding<'a>>,
810 pub introduced_by_item: bool,
813 /// Used for better errors for E0773
814 enum BuiltinMacroState {
815 NotYetSeen(SyntaxExtensionKind),
820 resolutions: DeriveResolutions,
821 helper_attrs: Vec<(usize, Ident)>,
822 has_derive_copy: bool,
825 /// The main resolver class.
827 /// This is the visitor that walks the whole crate.
828 pub struct Resolver<'a> {
829 session: &'a Session,
831 definitions: Definitions,
833 graph_root: Module<'a>,
835 prelude: Option<Module<'a>>,
836 extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'a>>,
838 /// N.B., this is used only for better diagnostics, not name resolution itself.
839 has_self: FxHashSet<DefId>,
841 /// Names of fields of an item `DefId` accessible with dot syntax.
842 /// Used for hints during error reporting.
843 field_names: FxHashMap<DefId, Vec<Spanned<Symbol>>>,
845 /// All imports known to succeed or fail.
846 determined_imports: Vec<&'a Import<'a>>,
848 /// All non-determined imports.
849 indeterminate_imports: Vec<&'a Import<'a>>,
851 // Spans for local variables found during pattern resolution.
852 // Used for suggestions during error reporting.
853 pat_span_map: NodeMap<Span>,
855 /// Resolutions for nodes that have a single resolution.
856 partial_res_map: NodeMap<PartialRes>,
857 /// Resolutions for import nodes, which have multiple resolutions in different namespaces.
858 import_res_map: NodeMap<PerNS<Option<Res>>>,
859 /// Resolutions for labels (node IDs of their corresponding blocks or loops).
860 label_res_map: NodeMap<NodeId>,
862 /// `CrateNum` resolutions of `extern crate` items.
863 extern_crate_map: FxHashMap<LocalDefId, CrateNum>,
864 reexport_map: FxHashMap<LocalDefId, Vec<ModChild>>,
865 trait_map: NodeMap<Vec<TraitCandidate>>,
867 /// A map from nodes to anonymous modules.
868 /// Anonymous modules are pseudo-modules that are implicitly created around items
869 /// contained within blocks.
871 /// For example, if we have this:
879 /// There will be an anonymous module created around `g` with the ID of the
880 /// entry block for `f`.
881 block_map: NodeMap<Module<'a>>,
882 /// A fake module that contains no definition and no prelude. Used so that
883 /// some AST passes can generate identifiers that only resolve to local or
885 empty_module: Module<'a>,
886 module_map: FxHashMap<DefId, Module<'a>>,
887 binding_parent_modules: FxHashMap<Interned<'a, NameBinding<'a>>, Module<'a>>,
888 underscore_disambiguator: u32,
890 /// Maps glob imports to the names of items actually imported.
891 glob_map: FxHashMap<LocalDefId, FxHashSet<Symbol>>,
892 /// Visibilities in "lowered" form, for all entities that have them.
893 visibilities: FxHashMap<LocalDefId, ty::Visibility>,
894 used_imports: FxHashSet<NodeId>,
895 maybe_unused_trait_imports: FxHashSet<LocalDefId>,
896 maybe_unused_extern_crates: Vec<(LocalDefId, Span)>,
898 /// Privacy errors are delayed until the end in order to deduplicate them.
899 privacy_errors: Vec<PrivacyError<'a>>,
900 /// Ambiguity errors are delayed for deduplication.
901 ambiguity_errors: Vec<AmbiguityError<'a>>,
902 /// `use` injections are delayed for better placement and deduplication.
903 use_injections: Vec<UseError<'a>>,
904 /// Crate-local macro expanded `macro_export` referred to by a module-relative path.
905 macro_expanded_macro_export_errors: BTreeSet<(Span, Span)>,
907 arenas: &'a ResolverArenas<'a>,
908 dummy_binding: &'a NameBinding<'a>,
910 crate_loader: CrateLoader<'a>,
911 macro_names: FxHashSet<Ident>,
912 builtin_macros: FxHashMap<Symbol, BuiltinMacroState>,
913 /// A small map keeping true kinds of built-in macros that appear to be fn-like on
914 /// the surface (`macro` items in libcore), but are actually attributes or derives.
915 builtin_macro_kinds: FxHashMap<LocalDefId, MacroKind>,
916 registered_attrs: FxHashSet<Ident>,
917 registered_tools: RegisteredTools,
918 macro_use_prelude: FxHashMap<Symbol, &'a NameBinding<'a>>,
919 /// FIXME: The only user of this is a doc link resolution hack for rustdoc.
920 all_macro_rules: FxHashMap<Symbol, Res>,
921 macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>,
922 dummy_ext_bang: Lrc<SyntaxExtension>,
923 dummy_ext_derive: Lrc<SyntaxExtension>,
924 non_macro_attr: Lrc<SyntaxExtension>,
925 local_macro_def_scopes: FxHashMap<LocalDefId, Module<'a>>,
926 ast_transform_scopes: FxHashMap<LocalExpnId, Module<'a>>,
927 unused_macros: FxHashMap<LocalDefId, (NodeId, Ident)>,
928 proc_macro_stubs: FxHashSet<LocalDefId>,
929 /// Traces collected during macro resolution and validated when it's complete.
930 single_segment_macro_resolutions:
931 Vec<(Ident, MacroKind, ParentScope<'a>, Option<&'a NameBinding<'a>>)>,
932 multi_segment_macro_resolutions:
933 Vec<(Vec<Segment>, Span, MacroKind, ParentScope<'a>, Option<Res>)>,
934 builtin_attrs: Vec<(Ident, ParentScope<'a>)>,
935 /// `derive(Copy)` marks items they are applied to so they are treated specially later.
936 /// Derive macros cannot modify the item themselves and have to store the markers in the global
937 /// context, so they attach the markers to derive container IDs using this resolver table.
938 containers_deriving_copy: FxHashSet<LocalExpnId>,
939 /// Parent scopes in which the macros were invoked.
940 /// FIXME: `derives` are missing in these parent scopes and need to be taken from elsewhere.
941 invocation_parent_scopes: FxHashMap<LocalExpnId, ParentScope<'a>>,
942 /// `macro_rules` scopes *produced* by expanding the macro invocations,
943 /// include all the `macro_rules` items and other invocations generated by them.
944 output_macro_rules_scopes: FxHashMap<LocalExpnId, MacroRulesScopeRef<'a>>,
945 /// Helper attributes that are in scope for the given expansion.
946 helper_attrs: FxHashMap<LocalExpnId, Vec<Ident>>,
947 /// Ready or in-progress results of resolving paths inside the `#[derive(...)]` attribute
948 /// with the given `ExpnId`.
949 derive_data: FxHashMap<LocalExpnId, DeriveData>,
951 /// Avoid duplicated errors for "name already defined".
952 name_already_seen: FxHashMap<Symbol, Span>,
954 potentially_unused_imports: Vec<&'a Import<'a>>,
956 /// Table for mapping struct IDs into struct constructor IDs,
957 /// it's not used during normal resolution, only for better error reporting.
958 /// Also includes of list of each fields visibility
959 struct_constructors: DefIdMap<(Res, ty::Visibility, Vec<ty::Visibility>)>,
961 /// Features enabled for this crate.
962 active_features: FxHashSet<Symbol>,
964 lint_buffer: LintBuffer,
966 next_node_id: NodeId,
968 node_id_to_def_id: FxHashMap<ast::NodeId, LocalDefId>,
969 def_id_to_node_id: IndexVec<LocalDefId, ast::NodeId>,
971 /// Indices of unnamed struct or variant fields with unresolved attributes.
972 placeholder_field_indices: FxHashMap<NodeId, usize>,
973 /// When collecting definitions from an AST fragment produced by a macro invocation `ExpnId`
974 /// we know what parent node that fragment should be attached to thanks to this table,
975 /// and how the `impl Trait` fragments were introduced.
976 invocation_parents: FxHashMap<LocalExpnId, (LocalDefId, ImplTraitContext)>,
978 /// Some way to know that we are in a *trait* impl in `visit_assoc_item`.
979 /// FIXME: Replace with a more general AST map (together with some other fields).
980 trait_impl_items: FxHashSet<LocalDefId>,
982 legacy_const_generic_args: FxHashMap<DefId, Option<Vec<usize>>>,
983 /// Amount of lifetime parameters for each item in the crate.
984 item_generics_num_lifetimes: FxHashMap<LocalDefId, usize>,
986 main_def: Option<MainDefinition>,
987 trait_impls: FxIndexMap<DefId, Vec<LocalDefId>>,
988 /// A list of proc macro LocalDefIds, written out in the order in which
989 /// they are declared in the static array generated by proc_macro_harness.
990 proc_macros: Vec<NodeId>,
991 confused_type_with_std_module: FxHashMap<Span, Span>,
993 access_levels: AccessLevels,
996 /// Nothing really interesting here; it just provides memory for the rest of the crate.
998 pub struct ResolverArenas<'a> {
999 modules: TypedArena<ModuleData<'a>>,
1000 local_modules: RefCell<Vec<Module<'a>>>,
1001 imports: TypedArena<Import<'a>>,
1002 name_resolutions: TypedArena<RefCell<NameResolution<'a>>>,
1003 ast_paths: TypedArena<ast::Path>,
1004 dropless: DroplessArena,
1007 impl<'a> ResolverArenas<'a> {
1010 parent: Option<Module<'a>>,
1014 no_implicit_prelude: bool,
1015 module_map: &mut FxHashMap<DefId, Module<'a>>,
1018 self.modules.alloc(ModuleData::new(parent, kind, expn_id, span, no_implicit_prelude));
1019 let def_id = module.opt_def_id();
1020 if def_id.map_or(true, |def_id| def_id.is_local()) {
1021 self.local_modules.borrow_mut().push(module);
1023 if let Some(def_id) = def_id {
1024 module_map.insert(def_id, module);
1028 fn local_modules(&'a self) -> std::cell::Ref<'a, Vec<Module<'a>>> {
1029 self.local_modules.borrow()
1031 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1032 self.dropless.alloc(name_binding)
1034 fn alloc_import(&'a self, import: Import<'a>) -> &'a Import<'_> {
1035 self.imports.alloc(import)
1037 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1038 self.name_resolutions.alloc(Default::default())
1040 fn alloc_macro_rules_scope(&'a self, scope: MacroRulesScope<'a>) -> MacroRulesScopeRef<'a> {
1041 Interned::new_unchecked(self.dropless.alloc(Cell::new(scope)))
1043 fn alloc_macro_rules_binding(
1045 binding: MacroRulesBinding<'a>,
1046 ) -> &'a MacroRulesBinding<'a> {
1047 self.dropless.alloc(binding)
1049 fn alloc_ast_paths(&'a self, paths: &[ast::Path]) -> &'a [ast::Path] {
1050 self.ast_paths.alloc_from_iter(paths.iter().cloned())
1052 fn alloc_pattern_spans(&'a self, spans: impl Iterator<Item = Span>) -> &'a [Span] {
1053 self.dropless.alloc_from_iter(spans)
1057 impl<'a> AsMut<Resolver<'a>> for Resolver<'a> {
1058 fn as_mut(&mut self) -> &mut Resolver<'a> {
1063 impl<'a, 'b> DefIdTree for &'a Resolver<'b> {
1064 fn parent(self, id: DefId) -> Option<DefId> {
1065 match id.as_local() {
1066 Some(id) => self.definitions.def_key(id).parent,
1067 None => self.cstore().def_key(id).parent,
1069 .map(|index| DefId { index, ..id })
1073 /// This interface is used through the AST→HIR step, to embed full paths into the HIR. After that
1074 /// the resolver is no longer needed as all the relevant information is inline.
1075 impl ResolverAstLowering for Resolver<'_> {
1076 fn def_key(&self, id: DefId) -> DefKey {
1077 if let Some(id) = id.as_local() {
1078 self.definitions.def_key(id)
1080 self.cstore().def_key(id)
1085 fn def_span(&self, id: LocalDefId) -> Span {
1086 self.definitions.def_span(id)
1089 fn item_generics_num_lifetimes(&self, def_id: DefId) -> usize {
1090 if let Some(def_id) = def_id.as_local() {
1091 self.item_generics_num_lifetimes[&def_id]
1093 self.cstore().item_generics_num_lifetimes(def_id, self.session)
1097 fn legacy_const_generic_args(&mut self, expr: &Expr) -> Option<Vec<usize>> {
1098 self.legacy_const_generic_args(expr)
1101 fn get_partial_res(&self, id: NodeId) -> Option<PartialRes> {
1102 self.partial_res_map.get(&id).cloned()
1105 fn get_import_res(&self, id: NodeId) -> PerNS<Option<Res>> {
1106 self.import_res_map.get(&id).cloned().unwrap_or_default()
1109 fn get_label_res(&self, id: NodeId) -> Option<NodeId> {
1110 self.label_res_map.get(&id).cloned()
1113 fn create_stable_hashing_context(&self) -> StableHashingContext<'_> {
1114 StableHashingContext::new(self.session, &self.definitions, self.crate_loader.cstore())
1117 fn definitions(&self) -> &Definitions {
1121 fn next_node_id(&mut self) -> NodeId {
1125 fn take_trait_map(&mut self, node: NodeId) -> Option<Vec<TraitCandidate>> {
1126 self.trait_map.remove(&node)
1129 fn opt_local_def_id(&self, node: NodeId) -> Option<LocalDefId> {
1130 self.node_id_to_def_id.get(&node).copied()
1133 fn local_def_id(&self, node: NodeId) -> LocalDefId {
1134 self.opt_local_def_id(node).unwrap_or_else(|| panic!("no entry for node id: `{:?}`", node))
1137 fn def_path_hash(&self, def_id: DefId) -> DefPathHash {
1138 match def_id.as_local() {
1139 Some(def_id) => self.definitions.def_path_hash(def_id),
1140 None => self.cstore().def_path_hash(def_id),
1144 /// Adds a definition with a parent definition.
1148 node_id: ast::NodeId,
1154 !self.node_id_to_def_id.contains_key(&node_id),
1155 "adding a def'n for node-id {:?} and data {:?} but a previous def'n exists: {:?}",
1158 self.definitions.def_key(self.node_id_to_def_id[&node_id]),
1161 let def_id = self.definitions.create_def(parent, data, expn_id, span);
1163 // Some things for which we allocate `LocalDefId`s don't correspond to
1164 // anything in the AST, so they don't have a `NodeId`. For these cases
1165 // we don't need a mapping from `NodeId` to `LocalDefId`.
1166 if node_id != ast::DUMMY_NODE_ID {
1167 debug!("create_def: def_id_to_node_id[{:?}] <-> {:?}", def_id, node_id);
1168 self.node_id_to_def_id.insert(node_id, def_id);
1170 assert_eq!(self.def_id_to_node_id.push(node_id), def_id);
1175 fn decl_macro_kind(&self, def_id: LocalDefId) -> MacroKind {
1176 self.builtin_macro_kinds.get(&def_id).copied().unwrap_or(MacroKind::Bang)
1180 impl<'a> Resolver<'a> {
1182 session: &'a Session,
1185 metadata_loader: Box<MetadataLoaderDyn>,
1186 arenas: &'a ResolverArenas<'a>,
1188 let root_def_id = CRATE_DEF_ID.to_def_id();
1189 let mut module_map = FxHashMap::default();
1190 let graph_root = arenas.new_module(
1192 ModuleKind::Def(DefKind::Mod, root_def_id, kw::Empty),
1194 krate.spans.inner_span,
1195 session.contains_name(&krate.attrs, sym::no_implicit_prelude),
1198 let empty_module = arenas.new_module(
1200 ModuleKind::Def(DefKind::Mod, root_def_id, kw::Empty),
1204 &mut FxHashMap::default(),
1207 let definitions = Definitions::new(session.local_stable_crate_id(), krate.spans.inner_span);
1208 let root = definitions.get_root_def();
1210 let mut visibilities = FxHashMap::default();
1211 visibilities.insert(CRATE_DEF_ID, ty::Visibility::Public);
1213 let mut def_id_to_node_id = IndexVec::default();
1214 assert_eq!(def_id_to_node_id.push(CRATE_NODE_ID), root);
1215 let mut node_id_to_def_id = FxHashMap::default();
1216 node_id_to_def_id.insert(CRATE_NODE_ID, root);
1218 let mut invocation_parents = FxHashMap::default();
1219 invocation_parents.insert(LocalExpnId::ROOT, (root, ImplTraitContext::Existential));
1221 let mut extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'_>> = session
1225 .filter(|(_, entry)| entry.add_prelude)
1226 .map(|(name, _)| (Ident::from_str(name), Default::default()))
1229 if !session.contains_name(&krate.attrs, sym::no_core) {
1230 extern_prelude.insert(Ident::with_dummy_span(sym::core), Default::default());
1231 if !session.contains_name(&krate.attrs, sym::no_std) {
1232 extern_prelude.insert(Ident::with_dummy_span(sym::std), Default::default());
1236 let (registered_attrs, registered_tools) =
1237 macros::registered_attrs_and_tools(session, &krate.attrs);
1239 let features = session.features_untracked();
1241 let mut resolver = Resolver {
1246 // The outermost module has def ID 0; this is not reflected in the
1252 has_self: FxHashSet::default(),
1253 field_names: FxHashMap::default(),
1255 determined_imports: Vec::new(),
1256 indeterminate_imports: Vec::new(),
1258 pat_span_map: Default::default(),
1259 partial_res_map: Default::default(),
1260 import_res_map: Default::default(),
1261 label_res_map: Default::default(),
1262 extern_crate_map: Default::default(),
1263 reexport_map: FxHashMap::default(),
1264 trait_map: NodeMap::default(),
1265 underscore_disambiguator: 0,
1268 block_map: Default::default(),
1269 binding_parent_modules: FxHashMap::default(),
1270 ast_transform_scopes: FxHashMap::default(),
1272 glob_map: Default::default(),
1274 used_imports: FxHashSet::default(),
1275 maybe_unused_trait_imports: Default::default(),
1276 maybe_unused_extern_crates: Vec::new(),
1278 privacy_errors: Vec::new(),
1279 ambiguity_errors: Vec::new(),
1280 use_injections: Vec::new(),
1281 macro_expanded_macro_export_errors: BTreeSet::new(),
1284 dummy_binding: arenas.alloc_name_binding(NameBinding {
1285 kind: NameBindingKind::Res(Res::Err, false),
1287 expansion: LocalExpnId::ROOT,
1289 vis: ty::Visibility::Public,
1292 crate_loader: CrateLoader::new(session, metadata_loader, crate_name),
1293 macro_names: FxHashSet::default(),
1294 builtin_macros: Default::default(),
1295 builtin_macro_kinds: Default::default(),
1298 macro_use_prelude: FxHashMap::default(),
1299 all_macro_rules: Default::default(),
1300 macro_map: FxHashMap::default(),
1301 dummy_ext_bang: Lrc::new(SyntaxExtension::dummy_bang(session.edition())),
1302 dummy_ext_derive: Lrc::new(SyntaxExtension::dummy_derive(session.edition())),
1303 non_macro_attr: Lrc::new(SyntaxExtension::non_macro_attr(session.edition())),
1304 invocation_parent_scopes: Default::default(),
1305 output_macro_rules_scopes: Default::default(),
1306 helper_attrs: Default::default(),
1307 derive_data: Default::default(),
1308 local_macro_def_scopes: FxHashMap::default(),
1309 name_already_seen: FxHashMap::default(),
1310 potentially_unused_imports: Vec::new(),
1311 struct_constructors: Default::default(),
1312 unused_macros: Default::default(),
1313 proc_macro_stubs: Default::default(),
1314 single_segment_macro_resolutions: Default::default(),
1315 multi_segment_macro_resolutions: Default::default(),
1316 builtin_attrs: Default::default(),
1317 containers_deriving_copy: Default::default(),
1318 active_features: features
1319 .declared_lib_features
1321 .map(|(feat, ..)| *feat)
1322 .chain(features.declared_lang_features.iter().map(|(feat, ..)| *feat))
1324 lint_buffer: LintBuffer::default(),
1325 next_node_id: CRATE_NODE_ID,
1328 placeholder_field_indices: Default::default(),
1330 trait_impl_items: Default::default(),
1331 legacy_const_generic_args: Default::default(),
1332 item_generics_num_lifetimes: Default::default(),
1333 main_def: Default::default(),
1334 trait_impls: Default::default(),
1335 proc_macros: Default::default(),
1336 confused_type_with_std_module: Default::default(),
1337 access_levels: Default::default(),
1340 let root_parent_scope = ParentScope::module(graph_root, &resolver);
1341 resolver.invocation_parent_scopes.insert(LocalExpnId::ROOT, root_parent_scope);
1348 parent: Option<Module<'a>>,
1352 no_implicit_prelude: bool,
1354 let module_map = &mut self.module_map;
1355 self.arenas.new_module(parent, kind, expn_id, span, no_implicit_prelude, module_map)
1358 pub fn next_node_id(&mut self) -> NodeId {
1360 self.next_node_id.as_u32().checked_add(1).expect("input too large; ran out of NodeIds");
1361 mem::replace(&mut self.next_node_id, ast::NodeId::from_u32(next))
1364 pub fn lint_buffer(&mut self) -> &mut LintBuffer {
1365 &mut self.lint_buffer
1368 pub fn arenas() -> ResolverArenas<'a> {
1372 pub fn into_outputs(self) -> ResolverOutputs {
1373 let proc_macros = self.proc_macros.iter().map(|id| self.local_def_id(*id)).collect();
1374 let definitions = self.definitions;
1375 let visibilities = self.visibilities;
1376 let extern_crate_map = self.extern_crate_map;
1377 let reexport_map = self.reexport_map;
1378 let maybe_unused_trait_imports = self.maybe_unused_trait_imports;
1379 let maybe_unused_extern_crates = self.maybe_unused_extern_crates;
1380 let glob_map = self.glob_map;
1381 let main_def = self.main_def;
1382 let confused_type_with_std_module = self.confused_type_with_std_module;
1383 let access_levels = self.access_levels;
1386 cstore: Box::new(self.crate_loader.into_cstore()),
1392 maybe_unused_trait_imports,
1393 maybe_unused_extern_crates,
1394 extern_prelude: self
1397 .map(|(ident, entry)| (ident.name, entry.introduced_by_item))
1400 trait_impls: self.trait_impls,
1402 confused_type_with_std_module,
1403 registered_tools: self.registered_tools,
1407 pub fn clone_outputs(&self) -> ResolverOutputs {
1408 let proc_macros = self.proc_macros.iter().map(|id| self.local_def_id(*id)).collect();
1410 definitions: self.definitions.clone(),
1411 access_levels: self.access_levels.clone(),
1412 cstore: Box::new(self.cstore().clone()),
1413 visibilities: self.visibilities.clone(),
1414 extern_crate_map: self.extern_crate_map.clone(),
1415 reexport_map: self.reexport_map.clone(),
1416 glob_map: self.glob_map.clone(),
1417 maybe_unused_trait_imports: self.maybe_unused_trait_imports.clone(),
1418 maybe_unused_extern_crates: self.maybe_unused_extern_crates.clone(),
1419 extern_prelude: self
1422 .map(|(ident, entry)| (ident.name, entry.introduced_by_item))
1424 main_def: self.main_def,
1425 trait_impls: self.trait_impls.clone(),
1427 confused_type_with_std_module: self.confused_type_with_std_module.clone(),
1428 registered_tools: self.registered_tools.clone(),
1432 pub fn cstore(&self) -> &CStore {
1433 self.crate_loader.cstore()
1436 fn dummy_ext(&self, macro_kind: MacroKind) -> Lrc<SyntaxExtension> {
1438 MacroKind::Bang => self.dummy_ext_bang.clone(),
1439 MacroKind::Derive => self.dummy_ext_derive.clone(),
1440 MacroKind::Attr => self.non_macro_attr.clone(),
1444 /// Runs the function on each namespace.
1445 fn per_ns<F: FnMut(&mut Self, Namespace)>(&mut self, mut f: F) {
1451 fn is_builtin_macro(&mut self, res: Res) -> bool {
1452 self.get_macro(res).map_or(false, |ext| ext.builtin_name.is_some())
1455 fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
1457 match ctxt.outer_expn_data().macro_def_id {
1458 Some(def_id) => return def_id,
1459 None => ctxt.remove_mark(),
1464 /// Entry point to crate resolution.
1465 pub fn resolve_crate(&mut self, krate: &Crate) {
1466 self.session.time("resolve_crate", || {
1467 self.session.time("finalize_imports", || ImportResolver { r: self }.finalize_imports());
1468 self.session.time("resolve_access_levels", || {
1469 AccessLevelsVisitor::compute_access_levels(self, krate)
1471 self.session.time("finalize_macro_resolutions", || self.finalize_macro_resolutions());
1472 self.session.time("late_resolve_crate", || self.late_resolve_crate(krate));
1473 self.session.time("resolve_main", || self.resolve_main());
1474 self.session.time("resolve_check_unused", || self.check_unused(krate));
1475 self.session.time("resolve_report_errors", || self.report_errors(krate));
1476 self.session.time("resolve_postprocess", || self.crate_loader.postprocess(krate));
1480 pub fn traits_in_scope(
1482 current_trait: Option<Module<'a>>,
1483 parent_scope: &ParentScope<'a>,
1484 ctxt: SyntaxContext,
1485 assoc_item: Option<(Symbol, Namespace)>,
1486 ) -> Vec<TraitCandidate> {
1487 let mut found_traits = Vec::new();
1489 if let Some(module) = current_trait {
1490 if self.trait_may_have_item(Some(module), assoc_item) {
1491 let def_id = module.def_id();
1492 found_traits.push(TraitCandidate { def_id, import_ids: smallvec![] });
1496 self.visit_scopes(ScopeSet::All(TypeNS, false), parent_scope, ctxt, |this, scope, _, _| {
1498 Scope::Module(module, _) => {
1499 this.traits_in_module(module, assoc_item, &mut found_traits);
1501 Scope::StdLibPrelude => {
1502 if let Some(module) = this.prelude {
1503 this.traits_in_module(module, assoc_item, &mut found_traits);
1506 Scope::ExternPrelude | Scope::ToolPrelude | Scope::BuiltinTypes => {}
1507 _ => unreachable!(),
1515 fn traits_in_module(
1518 assoc_item: Option<(Symbol, Namespace)>,
1519 found_traits: &mut Vec<TraitCandidate>,
1521 module.ensure_traits(self);
1522 let traits = module.traits.borrow();
1523 for (trait_name, trait_binding) in traits.as_ref().unwrap().iter() {
1524 if self.trait_may_have_item(trait_binding.module(), assoc_item) {
1525 let def_id = trait_binding.res().def_id();
1526 let import_ids = self.find_transitive_imports(&trait_binding.kind, *trait_name);
1527 found_traits.push(TraitCandidate { def_id, import_ids });
1532 // List of traits in scope is pruned on best effort basis. We reject traits not having an
1533 // associated item with the given name and namespace (if specified). This is a conservative
1534 // optimization, proper hygienic type-based resolution of associated items is done in typeck.
1535 // We don't reject trait aliases (`trait_module == None`) because we don't have access to their
1536 // associated items.
1537 fn trait_may_have_item(
1539 trait_module: Option<Module<'a>>,
1540 assoc_item: Option<(Symbol, Namespace)>,
1542 match (trait_module, assoc_item) {
1543 (Some(trait_module), Some((name, ns))) => {
1544 self.resolutions(trait_module).borrow().iter().any(|resolution| {
1545 let (&BindingKey { ident: assoc_ident, ns: assoc_ns, .. }, _) = resolution;
1546 assoc_ns == ns && assoc_ident.name == name
1553 fn find_transitive_imports(
1555 mut kind: &NameBindingKind<'_>,
1557 ) -> SmallVec<[LocalDefId; 1]> {
1558 let mut import_ids = smallvec![];
1559 while let NameBindingKind::Import { import, binding, .. } = kind {
1560 let id = self.local_def_id(import.id);
1561 self.maybe_unused_trait_imports.insert(id);
1562 self.add_to_glob_map(&import, trait_name);
1563 import_ids.push(id);
1564 kind = &binding.kind;
1569 fn new_key(&mut self, ident: Ident, ns: Namespace) -> BindingKey {
1570 let ident = ident.normalize_to_macros_2_0();
1571 let disambiguator = if ident.name == kw::Underscore {
1572 self.underscore_disambiguator += 1;
1573 self.underscore_disambiguator
1577 BindingKey { ident, ns, disambiguator }
1580 fn resolutions(&mut self, module: Module<'a>) -> &'a Resolutions<'a> {
1581 if module.populate_on_access.get() {
1582 module.populate_on_access.set(false);
1583 self.build_reduced_graph_external(module);
1585 &module.lazy_resolutions
1592 ) -> &'a RefCell<NameResolution<'a>> {
1594 .resolutions(module)
1597 .or_insert_with(|| self.arenas.alloc_name_resolution())
1603 used_binding: &'a NameBinding<'a>,
1604 is_lexical_scope: bool,
1606 if let Some((b2, kind)) = used_binding.ambiguity {
1607 self.ambiguity_errors.push(AmbiguityError {
1612 misc1: AmbiguityErrorMisc::None,
1613 misc2: AmbiguityErrorMisc::None,
1616 if let NameBindingKind::Import { import, binding, ref used } = used_binding.kind {
1617 // Avoid marking `extern crate` items that refer to a name from extern prelude,
1618 // but not introduce it, as used if they are accessed from lexical scope.
1619 if is_lexical_scope {
1620 if let Some(entry) = self.extern_prelude.get(&ident.normalize_to_macros_2_0()) {
1621 if let Some(crate_item) = entry.extern_crate_item {
1622 if ptr::eq(used_binding, crate_item) && !entry.introduced_by_item {
1629 import.used.set(true);
1630 self.used_imports.insert(import.id);
1631 self.add_to_glob_map(&import, ident);
1632 self.record_use(ident, binding, false);
1637 fn add_to_glob_map(&mut self, import: &Import<'_>, ident: Ident) {
1638 if import.is_glob() {
1639 let def_id = self.local_def_id(import.id);
1640 self.glob_map.entry(def_id).or_default().insert(ident.name);
1644 fn resolve_crate_root(&mut self, ident: Ident) -> Module<'a> {
1645 debug!("resolve_crate_root({:?})", ident);
1646 let mut ctxt = ident.span.ctxt();
1647 let mark = if ident.name == kw::DollarCrate {
1648 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
1649 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
1650 // as described in `SyntaxContext::apply_mark`, so we ignore prepended opaque marks.
1651 // FIXME: This is only a guess and it doesn't work correctly for `macro_rules!`
1652 // definitions actually produced by `macro` and `macro` definitions produced by
1653 // `macro_rules!`, but at least such configurations are not stable yet.
1654 ctxt = ctxt.normalize_to_macro_rules();
1656 "resolve_crate_root: marks={:?}",
1657 ctxt.marks().into_iter().map(|(i, t)| (i.expn_data(), t)).collect::<Vec<_>>()
1659 let mut iter = ctxt.marks().into_iter().rev().peekable();
1660 let mut result = None;
1661 // Find the last opaque mark from the end if it exists.
1662 while let Some(&(mark, transparency)) = iter.peek() {
1663 if transparency == Transparency::Opaque {
1664 result = Some(mark);
1671 "resolve_crate_root: found opaque mark {:?} {:?}",
1673 result.map(|r| r.expn_data())
1675 // Then find the last semi-transparent mark from the end if it exists.
1676 for (mark, transparency) in iter {
1677 if transparency == Transparency::SemiTransparent {
1678 result = Some(mark);
1684 "resolve_crate_root: found semi-transparent mark {:?} {:?}",
1686 result.map(|r| r.expn_data())
1690 debug!("resolve_crate_root: not DollarCrate");
1691 ctxt = ctxt.normalize_to_macros_2_0();
1692 ctxt.adjust(ExpnId::root())
1694 let module = match mark {
1695 Some(def) => self.expn_def_scope(def),
1698 "resolve_crate_root({:?}): found no mark (ident.span = {:?})",
1701 return self.graph_root;
1704 let module = self.expect_module(
1705 module.opt_def_id().map_or(LOCAL_CRATE, |def_id| def_id.krate).as_def_id(),
1708 "resolve_crate_root({:?}): got module {:?} ({:?}) (ident.span = {:?})",
1717 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
1718 let mut module = self.expect_module(module.nearest_parent_mod());
1719 while module.span.ctxt().normalize_to_macros_2_0() != *ctxt {
1720 let parent = module.parent.unwrap_or_else(|| self.expn_def_scope(ctxt.remove_mark()));
1721 module = self.expect_module(parent.nearest_parent_mod());
1726 fn record_partial_res(&mut self, node_id: NodeId, resolution: PartialRes) {
1727 debug!("(recording res) recording {:?} for {}", resolution, node_id);
1728 if let Some(prev_res) = self.partial_res_map.insert(node_id, resolution) {
1729 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
1733 fn record_pat_span(&mut self, node: NodeId, span: Span) {
1734 debug!("(recording pat) recording {:?} for {:?}", node, span);
1735 self.pat_span_map.insert(node, span);
1738 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
1739 vis.is_accessible_from(module.nearest_parent_mod(), self)
1742 fn set_binding_parent_module(&mut self, binding: &'a NameBinding<'a>, module: Module<'a>) {
1743 if let Some(old_module) =
1744 self.binding_parent_modules.insert(Interned::new_unchecked(binding), module)
1746 if !ptr::eq(module, old_module) {
1747 span_bug!(binding.span, "parent module is reset for binding");
1752 fn disambiguate_macro_rules_vs_modularized(
1754 macro_rules: &'a NameBinding<'a>,
1755 modularized: &'a NameBinding<'a>,
1757 // Some non-controversial subset of ambiguities "modularized macro name" vs "macro_rules"
1758 // is disambiguated to mitigate regressions from macro modularization.
1759 // Scoping for `macro_rules` behaves like scoping for `let` at module level, in general.
1761 self.binding_parent_modules.get(&Interned::new_unchecked(macro_rules)),
1762 self.binding_parent_modules.get(&Interned::new_unchecked(modularized)),
1764 (Some(macro_rules), Some(modularized)) => {
1765 macro_rules.nearest_parent_mod() == modularized.nearest_parent_mod()
1766 && modularized.is_ancestor_of(macro_rules)
1772 fn extern_prelude_get(&mut self, ident: Ident, finalize: bool) -> Option<&'a NameBinding<'a>> {
1773 if ident.is_path_segment_keyword() {
1774 // Make sure `self`, `super` etc produce an error when passed to here.
1777 self.extern_prelude.get(&ident.normalize_to_macros_2_0()).cloned().and_then(|entry| {
1778 if let Some(binding) = entry.extern_crate_item {
1779 if finalize && entry.introduced_by_item {
1780 self.record_use(ident, binding, false);
1784 let crate_id = if finalize {
1785 let Some(crate_id) =
1786 self.crate_loader.process_path_extern(ident.name, ident.span) else { return Some(self.dummy_binding); };
1789 self.crate_loader.maybe_process_path_extern(ident.name)?
1791 let crate_root = self.expect_module(crate_id.as_def_id());
1793 (crate_root, ty::Visibility::Public, DUMMY_SP, LocalExpnId::ROOT)
1794 .to_name_binding(self.arenas),
1800 /// Rustdoc uses this to resolve doc link paths in a recoverable way. `PathResult<'a>`
1801 /// isn't something that can be returned because it can't be made to live that long,
1802 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
1803 /// just that an error occurred.
1804 pub fn resolve_rustdoc_path(
1808 mut module_id: DefId,
1811 Vec::from_iter(path_str.split("::").map(Ident::from_str).map(Segment::from_ident));
1812 if let Some(segment) = segments.first_mut() {
1813 if segment.ident.name == kw::Crate {
1814 // FIXME: `resolve_path` always resolves `crate` to the current crate root, but
1815 // rustdoc wants it to resolve to the `module_id`'s crate root. This trick of
1816 // replacing `crate` with `self` and changing the current module should achieve
1818 segment.ident.name = kw::SelfLower;
1819 module_id = module_id.krate.as_def_id();
1820 } else if segment.ident.name == kw::Empty {
1821 segment.ident.name = kw::PathRoot;
1825 let module = self.expect_module(module_id);
1826 match self.maybe_resolve_path(&segments, Some(ns), &ParentScope::module(module, self)) {
1827 PathResult::Module(ModuleOrUniformRoot::Module(module)) => Some(module.res().unwrap()),
1828 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 => {
1829 Some(path_res.base_res())
1831 PathResult::Module(ModuleOrUniformRoot::ExternPrelude)
1832 | PathResult::NonModule(..)
1833 | PathResult::Failed { .. } => None,
1834 PathResult::Module(..) | PathResult::Indeterminate => unreachable!(),
1839 pub fn graph_root(&self) -> Module<'a> {
1844 pub fn take_all_macro_rules(&mut self) -> FxHashMap<Symbol, Res> {
1845 mem::take(&mut self.all_macro_rules)
1849 /// For local modules returns only reexports, for external modules returns all children.
1850 pub fn module_children_or_reexports(&self, def_id: DefId) -> Vec<ModChild> {
1851 if let Some(def_id) = def_id.as_local() {
1852 self.reexport_map.get(&def_id).cloned().unwrap_or_default()
1854 self.cstore().module_children_untracked(def_id, self.session)
1858 /// Retrieves the span of the given `DefId` if `DefId` is in the local crate.
1860 pub fn opt_span(&self, def_id: DefId) -> Option<Span> {
1861 def_id.as_local().map(|def_id| self.definitions.def_span(def_id))
1864 /// Checks if an expression refers to a function marked with
1865 /// `#[rustc_legacy_const_generics]` and returns the argument index list
1866 /// from the attribute.
1867 pub fn legacy_const_generic_args(&mut self, expr: &Expr) -> Option<Vec<usize>> {
1868 if let ExprKind::Path(None, path) = &expr.kind {
1869 // Don't perform legacy const generics rewriting if the path already
1870 // has generic arguments.
1871 if path.segments.last().unwrap().args.is_some() {
1875 let partial_res = self.partial_res_map.get(&expr.id)?;
1876 if partial_res.unresolved_segments() != 0 {
1880 if let Res::Def(def::DefKind::Fn, def_id) = partial_res.base_res() {
1881 // We only support cross-crate argument rewriting. Uses
1882 // within the same crate should be updated to use the new
1883 // const generics style.
1884 if def_id.is_local() {
1888 if let Some(v) = self.legacy_const_generic_args.get(&def_id) {
1894 .item_attrs_untracked(def_id, self.session)
1895 .find(|a| a.has_name(sym::rustc_legacy_const_generics))?;
1896 let mut ret = Vec::new();
1897 for meta in attr.meta_item_list()? {
1898 match meta.literal()?.kind {
1899 LitKind::Int(a, _) => ret.push(a as usize),
1900 _ => panic!("invalid arg index"),
1903 // Cache the lookup to avoid parsing attributes for an iterm multiple times.
1904 self.legacy_const_generic_args.insert(def_id, Some(ret.clone()));
1911 fn resolve_main(&mut self) {
1912 let module = self.graph_root;
1913 let ident = Ident::with_dummy_span(sym::main);
1914 let parent_scope = &ParentScope::module(module, self);
1916 let Ok(name_binding) = self.maybe_resolve_ident_in_module(
1917 ModuleOrUniformRoot::Module(module),
1925 let res = name_binding.res();
1926 let is_import = name_binding.is_import();
1927 let span = name_binding.span;
1928 if let Res::Def(DefKind::Fn, _) = res {
1929 self.record_use(ident, name_binding, false);
1931 self.main_def = Some(MainDefinition { res, is_import, span });
1935 fn names_to_string(names: &[Symbol]) -> String {
1936 let mut result = String::new();
1937 for (i, name) in names.iter().filter(|name| **name != kw::PathRoot).enumerate() {
1939 result.push_str("::");
1941 if Ident::with_dummy_span(*name).is_raw_guess() {
1942 result.push_str("r#");
1944 result.push_str(name.as_str());
1949 fn path_names_to_string(path: &Path) -> String {
1950 names_to_string(&path.segments.iter().map(|seg| seg.ident.name).collect::<Vec<_>>())
1953 /// A somewhat inefficient routine to obtain the name of a module.
1954 fn module_to_string(module: Module<'_>) -> Option<String> {
1955 let mut names = Vec::new();
1957 fn collect_mod(names: &mut Vec<Symbol>, module: Module<'_>) {
1958 if let ModuleKind::Def(.., name) = module.kind {
1959 if let Some(parent) = module.parent {
1961 collect_mod(names, parent);
1964 names.push(Symbol::intern("<opaque>"));
1965 collect_mod(names, module.parent.unwrap());
1968 collect_mod(&mut names, module);
1970 if names.is_empty() {
1974 Some(names_to_string(&names))
1977 #[derive(Copy, Clone, Debug)]
1979 /// Do not issue the lint.
1982 /// This lint applies to some arbitrary path; e.g., `impl ::foo::Bar`.
1983 /// In this case, we can take the span of that path.
1984 SimplePath(NodeId, Span),
1986 /// This lint comes from a `use` statement. In this case, what we
1987 /// care about really is the *root* `use` statement; e.g., if we
1988 /// have nested things like `use a::{b, c}`, we care about the
1990 UsePath { root_id: NodeId, root_span: Span, path_span: Span },
1992 /// This is the "trait item" from a fully qualified path. For example,
1993 /// we might be resolving `X::Y::Z` from a path like `<T as X::Y>::Z`.
1994 /// The `path_span` is the span of the to the trait itself (`X::Y`).
1995 QPathTrait { qpath_id: NodeId, qpath_span: Span, path_span: Span },
1999 fn node_id_and_path_span(&self) -> Option<(NodeId, Span)> {
2001 Finalize::No => None,
2002 Finalize::SimplePath(id, path_span)
2003 | Finalize::UsePath { root_id: id, path_span, .. }
2004 | Finalize::QPathTrait { qpath_id: id, path_span, .. } => Some((id, path_span)),
2008 fn node_id(&self) -> Option<NodeId> {
2009 self.node_id_and_path_span().map(|(id, _)| id)
2012 fn path_span(&self) -> Option<Span> {
2013 self.node_id_and_path_span().map(|(_, path_span)| path_span)
2017 pub fn provide(providers: &mut Providers) {
2018 late::lifetimes::provide(providers);