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(if_let_guard)]
13 #![cfg_attr(bootstrap, feature(let_chains))]
14 #![feature(iter_intersperse)]
16 #![feature(never_type)]
17 #![recursion_limit = "256"]
18 #![allow(rustdoc::private_intra_doc_links)]
19 #![allow(rustc::potential_query_instability)]
24 pub use rustc_hir::def::{Namespace, PerNS};
26 use rustc_arena::{DroplessArena, TypedArena};
27 use rustc_ast::node_id::NodeMap;
28 use rustc_ast::{self as ast, NodeId, CRATE_NODE_ID};
29 use rustc_ast::{AngleBracketedArg, Crate, Expr, ExprKind, GenericArg, GenericArgs, LitKind, Path};
30 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet};
31 use rustc_data_structures::intern::Interned;
32 use rustc_data_structures::sync::Lrc;
33 use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed};
34 use rustc_expand::base::{DeriveResolutions, SyntaxExtension, SyntaxExtensionKind};
35 use rustc_hir::def::Namespace::*;
36 use rustc_hir::def::{self, CtorOf, DefKind, LifetimeRes, PartialRes};
37 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId};
38 use rustc_hir::def_id::{CRATE_DEF_ID, LOCAL_CRATE};
39 use rustc_hir::definitions::{DefPathData, Definitions};
40 use rustc_hir::TraitCandidate;
41 use rustc_index::vec::IndexVec;
42 use rustc_metadata::creader::{CStore, CrateLoader};
43 use rustc_middle::metadata::ModChild;
44 use rustc_middle::middle::privacy::AccessLevels;
45 use rustc_middle::span_bug;
46 use rustc_middle::ty::query::Providers;
47 use rustc_middle::ty::{self, DefIdTree, MainDefinition, RegisteredTools, ResolverOutputs};
48 use rustc_query_system::ich::StableHashingContext;
49 use rustc_session::cstore::{CrateStore, CrateStoreDyn, MetadataLoaderDyn};
50 use rustc_session::lint::LintBuffer;
51 use rustc_session::Session;
52 use rustc_span::hygiene::{ExpnId, LocalExpnId, 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, ptr};
63 use diagnostics::{ImportSuggestion, LabelSuggestion, Suggestion};
64 use imports::{Import, ImportKind, ImportResolver, NameResolution};
65 use late::{HasGenericParams, PathSource, PatternSource};
66 use macros::{MacroRulesBinding, MacroRulesScope, MacroRulesScopeRef};
68 use crate::access_levels::AccessLevelsVisitor;
70 type Res = def::Res<NodeId>;
73 mod build_reduced_graph;
87 #[derive(Copy, Clone, PartialEq, Debug)]
88 pub enum Determinacy {
94 fn determined(determined: bool) -> Determinacy {
95 if determined { Determinacy::Determined } else { Determinacy::Undetermined }
99 /// A specific scope in which a name can be looked up.
100 /// This enum is currently used only for early resolution (imports and macros),
101 /// but not for late resolution yet.
102 #[derive(Clone, Copy)]
104 DeriveHelpers(LocalExpnId),
106 MacroRules(MacroRulesScopeRef<'a>),
108 // The node ID is for reporting the `PROC_MACRO_DERIVE_RESOLUTION_FALLBACK`
109 // lint if it should be reported.
110 Module(Module<'a>, Option<NodeId>),
120 /// Names from different contexts may want to visit different subsets of all specific scopes
121 /// with different restrictions when looking up the resolution.
122 /// This enum is currently used only for early resolution (imports and macros),
123 /// but not for late resolution yet.
124 #[derive(Clone, Copy)]
126 /// All scopes with the given namespace.
127 All(Namespace, /*is_import*/ bool),
128 /// Crate root, then extern prelude (used for mixed 2015-2018 mode in macros).
129 AbsolutePath(Namespace),
130 /// All scopes with macro namespace and the given macro kind restriction.
132 /// All scopes with the given namespace, used for partially performing late resolution.
133 /// The node id enables lints and is used for reporting them.
134 Late(Namespace, Module<'a>, Option<NodeId>),
137 /// Everything you need to know about a name's location to resolve it.
138 /// Serves as a starting point for the scope visitor.
139 /// This struct is currently used only for early resolution (imports and macros),
140 /// but not for late resolution yet.
141 #[derive(Clone, Copy, Debug)]
142 pub struct ParentScope<'a> {
143 pub module: Module<'a>,
144 expansion: LocalExpnId,
145 pub macro_rules: MacroRulesScopeRef<'a>,
146 derives: &'a [ast::Path],
149 impl<'a> ParentScope<'a> {
150 /// Creates a parent scope with the passed argument used as the module scope component,
151 /// and other scope components set to default empty values.
152 pub fn module(module: Module<'a>, resolver: &Resolver<'a>) -> ParentScope<'a> {
155 expansion: LocalExpnId::ROOT,
156 macro_rules: resolver.arenas.alloc_macro_rules_scope(MacroRulesScope::Empty),
162 #[derive(Copy, Debug, Clone)]
163 enum ImplTraitContext {
165 Universal(LocalDefId),
169 struct BindingError {
171 origin: BTreeSet<Span>,
172 target: BTreeSet<Span>,
176 impl PartialOrd for BindingError {
177 fn partial_cmp(&self, other: &BindingError) -> Option<cmp::Ordering> {
178 Some(self.cmp(other))
182 impl PartialEq for BindingError {
183 fn eq(&self, other: &BindingError) -> bool {
184 self.name == other.name
188 impl Ord for BindingError {
189 fn cmp(&self, other: &BindingError) -> cmp::Ordering {
190 self.name.cmp(&other.name)
194 enum ResolutionError<'a> {
195 /// Error E0401: can't use type or const parameters from outer function.
196 GenericParamsFromOuterFunction(Res, HasGenericParams),
197 /// Error E0403: the name is already used for a type or const parameter in this generic
199 NameAlreadyUsedInParameterList(Symbol, Span),
200 /// Error E0407: method is not a member of trait.
201 MethodNotMemberOfTrait(Ident, String, Option<Symbol>),
202 /// Error E0437: type is not a member of trait.
203 TypeNotMemberOfTrait(Ident, String, Option<Symbol>),
204 /// Error E0438: const is not a member of trait.
205 ConstNotMemberOfTrait(Ident, String, Option<Symbol>),
206 /// Error E0408: variable `{}` is not bound in all patterns.
207 VariableNotBoundInPattern(BindingError, ParentScope<'a>),
208 /// Error E0409: variable `{}` is bound in inconsistent ways within the same match arm.
209 VariableBoundWithDifferentMode(Symbol, Span),
210 /// Error E0415: identifier is bound more than once in this parameter list.
211 IdentifierBoundMoreThanOnceInParameterList(Symbol),
212 /// Error E0416: identifier is bound more than once in the same pattern.
213 IdentifierBoundMoreThanOnceInSamePattern(Symbol),
214 /// Error E0426: use of undeclared label.
215 UndeclaredLabel { name: Symbol, suggestion: Option<LabelSuggestion> },
216 /// Error E0429: `self` imports are only allowed within a `{ }` list.
217 SelfImportsOnlyAllowedWithin { root: bool, span_with_rename: Span },
218 /// Error E0430: `self` import can only appear once in the list.
219 SelfImportCanOnlyAppearOnceInTheList,
220 /// Error E0431: `self` import can only appear in an import list with a non-empty prefix.
221 SelfImportOnlyInImportListWithNonEmptyPrefix,
222 /// Error E0433: failed to resolve.
223 FailedToResolve { label: String, suggestion: Option<Suggestion> },
224 /// Error E0434: can't capture dynamic environment in a fn item.
225 CannotCaptureDynamicEnvironmentInFnItem,
226 /// Error E0435: attempt to use a non-constant value in a constant.
227 AttemptToUseNonConstantValueInConstant(
229 /* suggestion */ &'static str,
230 /* current */ &'static str,
232 /// Error E0530: `X` bindings cannot shadow `Y`s.
233 BindingShadowsSomethingUnacceptable {
234 shadowing_binding: PatternSource,
236 participle: &'static str,
237 article: &'static str,
238 shadowed_binding: Res,
239 shadowed_binding_span: Span,
241 /// Error E0128: generic parameters with a default cannot use forward-declared identifiers.
242 ForwardDeclaredGenericParam,
243 /// ERROR E0770: the type of const parameters must not depend on other generic parameters.
244 ParamInTyOfConstParam(Symbol),
245 /// generic parameters must not be used inside const evaluations.
247 /// This error is only emitted when using `min_const_generics`.
248 ParamInNonTrivialAnonConst { name: Symbol, is_type: bool },
249 /// Error E0735: generic parameters with a default cannot use `Self`
250 SelfInGenericParamDefault,
251 /// Error E0767: use of unreachable label
252 UnreachableLabel { name: Symbol, definition_span: Span, suggestion: Option<LabelSuggestion> },
253 /// Error E0323, E0324, E0325: mismatch between trait item and impl item.
258 trait_item_span: Span,
259 code: rustc_errors::DiagnosticId,
261 /// Inline asm `sym` operand must refer to a `fn` or `static`.
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,
283 /// Signals whether this `PathSegment` has lifetime arguments.
284 has_lifetime_args: bool,
289 fn from_path(path: &Path) -> Vec<Segment> {
290 path.segments.iter().map(|s| s.into()).collect()
293 fn from_ident(ident: Ident) -> Segment {
297 has_generic_args: false,
298 has_lifetime_args: false,
303 fn from_ident_and_id(ident: Ident, id: NodeId) -> Segment {
307 has_generic_args: false,
308 has_lifetime_args: false,
313 fn names_to_string(segments: &[Segment]) -> String {
314 names_to_string(&segments.iter().map(|seg| seg.ident.name).collect::<Vec<_>>())
318 impl<'a> From<&'a ast::PathSegment> for Segment {
319 fn from(seg: &'a ast::PathSegment) -> Segment {
320 let has_generic_args = seg.args.is_some();
321 let (args_span, has_lifetime_args) = if let Some(args) = seg.args.as_deref() {
323 GenericArgs::AngleBracketed(args) => {
324 let found_lifetimes = args
327 .any(|arg| matches!(arg, AngleBracketedArg::Arg(GenericArg::Lifetime(_))));
328 (args.span, found_lifetimes)
330 GenericArgs::Parenthesized(args) => (args.span, true),
345 /// An intermediate resolution result.
347 /// This refers to the thing referred by a name. The difference between `Res` and `Item` is that
348 /// items are visible in their whole block, while `Res`es only from the place they are defined
351 enum LexicalScopeBinding<'a> {
352 Item(&'a NameBinding<'a>),
356 impl<'a> LexicalScopeBinding<'a> {
357 fn res(self) -> Res {
359 LexicalScopeBinding::Item(binding) => binding.res(),
360 LexicalScopeBinding::Res(res) => res,
365 #[derive(Copy, Clone, Debug)]
366 enum ModuleOrUniformRoot<'a> {
370 /// Virtual module that denotes resolution in crate root with fallback to extern prelude.
371 CrateRootAndExternPrelude,
373 /// Virtual module that denotes resolution in extern prelude.
374 /// Used for paths starting with `::` on 2018 edition.
377 /// Virtual module that denotes resolution in current scope.
378 /// Used only for resolving single-segment imports. The reason it exists is that import paths
379 /// are always split into two parts, the first of which should be some kind of module.
383 impl ModuleOrUniformRoot<'_> {
384 fn same_def(lhs: Self, rhs: Self) -> bool {
386 (ModuleOrUniformRoot::Module(lhs), ModuleOrUniformRoot::Module(rhs)) => {
390 ModuleOrUniformRoot::CrateRootAndExternPrelude,
391 ModuleOrUniformRoot::CrateRootAndExternPrelude,
393 | (ModuleOrUniformRoot::ExternPrelude, ModuleOrUniformRoot::ExternPrelude)
394 | (ModuleOrUniformRoot::CurrentScope, ModuleOrUniformRoot::CurrentScope) => true,
400 #[derive(Clone, Debug)]
401 enum PathResult<'a> {
402 Module(ModuleOrUniformRoot<'a>),
403 NonModule(PartialRes),
408 suggestion: Option<Suggestion>,
409 is_error_from_last_segment: bool,
413 impl<'a> PathResult<'a> {
416 is_error_from_last_segment: bool,
418 label_and_suggestion: impl FnOnce() -> (String, Option<Suggestion>),
419 ) -> PathResult<'a> {
420 let (label, suggestion) =
421 if finalize { label_and_suggestion() } else { (String::new(), None) };
422 PathResult::Failed { span, label, suggestion, is_error_from_last_segment }
428 /// An anonymous module; e.g., just a block.
433 /// { // This is an anonymous module
434 /// f(); // This resolves to (2) as we are inside the block.
437 /// f(); // Resolves to (1)
441 /// Any module with a name.
445 /// * A normal module – either `mod from_file;` or `mod from_block { }` –
446 /// or the crate root (which is conceptually a top-level module).
447 /// Note that the crate root's [name][Self::name] will be [`kw::Empty`].
448 /// * A trait or an enum (it implicitly contains associated types, methods and variant
450 Def(DefKind, DefId, Symbol),
454 /// Get name of the module.
455 pub fn name(&self) -> Option<Symbol> {
457 ModuleKind::Block(..) => None,
458 ModuleKind::Def(.., name) => Some(*name),
463 /// A key that identifies a binding in a given `Module`.
465 /// Multiple bindings in the same module can have the same key (in a valid
466 /// program) if all but one of them come from glob imports.
467 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
469 /// The identifier for the binding, always the `normalize_to_macros_2_0` version of the
473 /// 0 if ident is not `_`, otherwise a value that's unique to the specific
474 /// `_` in the expanded AST that introduced this binding.
478 type Resolutions<'a> = RefCell<FxIndexMap<BindingKey, &'a RefCell<NameResolution<'a>>>>;
480 /// One node in the tree of modules.
482 /// Note that a "module" in resolve is broader than a `mod` that you declare in Rust code. It may be one of these:
485 /// * crate root (aka, top-level anonymous module)
488 /// * curly-braced block with statements
490 /// You can use [`ModuleData::kind`] to determine the kind of module this is.
491 pub struct ModuleData<'a> {
492 /// The direct parent module (it may not be a `mod`, however).
493 parent: Option<Module<'a>>,
494 /// What kind of module this is, because this may not be a `mod`.
497 /// Mapping between names and their (possibly in-progress) resolutions in this module.
498 /// Resolutions in modules from other crates are not populated until accessed.
499 lazy_resolutions: Resolutions<'a>,
500 /// True if this is a module from other crate that needs to be populated on access.
501 populate_on_access: Cell<bool>,
503 /// Macro invocations that can expand into items in this module.
504 unexpanded_invocations: RefCell<FxHashSet<LocalExpnId>>,
506 /// Whether `#[no_implicit_prelude]` is active.
507 no_implicit_prelude: bool,
509 glob_importers: RefCell<Vec<&'a Import<'a>>>,
510 globs: RefCell<Vec<&'a Import<'a>>>,
512 /// Used to memoize the traits in this module for faster searches through all traits in scope.
513 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
515 /// Span of the module itself. Used for error reporting.
521 type Module<'a> = &'a ModuleData<'a>;
523 impl<'a> ModuleData<'a> {
525 parent: Option<Module<'a>>,
529 no_implicit_prelude: bool,
531 let is_foreign = match kind {
532 ModuleKind::Def(_, def_id, _) => !def_id.is_local(),
533 ModuleKind::Block(_) => false,
538 lazy_resolutions: Default::default(),
539 populate_on_access: Cell::new(is_foreign),
540 unexpanded_invocations: Default::default(),
542 glob_importers: RefCell::new(Vec::new()),
543 globs: RefCell::new(Vec::new()),
544 traits: RefCell::new(None),
550 fn for_each_child<R, F>(&'a self, resolver: &mut R, mut f: F)
552 R: AsMut<Resolver<'a>>,
553 F: FnMut(&mut R, Ident, Namespace, &'a NameBinding<'a>),
555 for (key, name_resolution) in resolver.as_mut().resolutions(self).borrow().iter() {
556 if let Some(binding) = name_resolution.borrow().binding {
557 f(resolver, key.ident, key.ns, binding);
562 /// This modifies `self` in place. The traits will be stored in `self.traits`.
563 fn ensure_traits<R>(&'a self, resolver: &mut R)
565 R: AsMut<Resolver<'a>>,
567 let mut traits = self.traits.borrow_mut();
568 if traits.is_none() {
569 let mut collected_traits = Vec::new();
570 self.for_each_child(resolver, |_, name, ns, binding| {
574 if let Res::Def(DefKind::Trait | DefKind::TraitAlias, _) = binding.res() {
575 collected_traits.push((name, binding))
578 *traits = Some(collected_traits.into_boxed_slice());
582 fn res(&self) -> Option<Res> {
584 ModuleKind::Def(kind, def_id, _) => Some(Res::Def(kind, def_id)),
589 // Public for rustdoc.
590 pub fn def_id(&self) -> DefId {
591 self.opt_def_id().expect("`ModuleData::def_id` is called on a block module")
594 fn opt_def_id(&self) -> Option<DefId> {
596 ModuleKind::Def(_, def_id, _) => Some(def_id),
601 // `self` resolves to the first module ancestor that `is_normal`.
602 fn is_normal(&self) -> bool {
603 matches!(self.kind, ModuleKind::Def(DefKind::Mod, _, _))
606 fn is_trait(&self) -> bool {
607 matches!(self.kind, ModuleKind::Def(DefKind::Trait, _, _))
610 fn nearest_item_scope(&'a self) -> Module<'a> {
612 ModuleKind::Def(DefKind::Enum | DefKind::Trait, ..) => {
613 self.parent.expect("enum or trait module without a parent")
619 /// The [`DefId`] of the nearest `mod` item ancestor (which may be this module).
620 /// This may be the crate root.
621 fn nearest_parent_mod(&self) -> DefId {
623 ModuleKind::Def(DefKind::Mod, def_id, _) => def_id,
624 _ => self.parent.expect("non-root module without parent").nearest_parent_mod(),
628 fn is_ancestor_of(&self, mut other: &Self) -> bool {
629 while !ptr::eq(self, other) {
630 if let Some(parent) = other.parent {
640 impl<'a> fmt::Debug for ModuleData<'a> {
641 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
642 write!(f, "{:?}", self.res())
646 /// Records a possibly-private value, type, or module definition.
647 #[derive(Clone, Debug)]
648 pub struct NameBinding<'a> {
649 kind: NameBindingKind<'a>,
650 ambiguity: Option<(&'a NameBinding<'a>, AmbiguityKind)>,
651 expansion: LocalExpnId,
656 pub trait ToNameBinding<'a> {
657 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
660 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
661 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
666 #[derive(Clone, Debug)]
667 enum NameBindingKind<'a> {
668 Res(Res, /* is_macro_export */ bool),
670 Import { binding: &'a NameBinding<'a>, import: &'a Import<'a>, used: Cell<bool> },
673 impl<'a> NameBindingKind<'a> {
674 /// Is this a name binding of an import?
675 fn is_import(&self) -> bool {
676 matches!(*self, NameBindingKind::Import { .. })
680 struct PrivacyError<'a> {
682 binding: &'a NameBinding<'a>,
686 struct UseError<'a> {
687 err: DiagnosticBuilder<'a, ErrorGuaranteed>,
688 /// Candidates which user could `use` to access the missing type.
689 candidates: Vec<ImportSuggestion>,
690 /// The `DefId` of the module to place the use-statements in.
692 /// Whether the diagnostic should say "instead" (as in `consider importing ... instead`).
694 /// Extra free-form suggestion.
695 suggestion: Option<(Span, &'static str, String, Applicability)>,
696 /// Path `Segment`s at the place of use that failed. Used for accurate suggestion after telling
697 /// the user to import the item directly.
701 #[derive(Clone, Copy, PartialEq, Debug)]
706 MacroRulesVsModularized,
714 fn descr(self) -> &'static str {
716 AmbiguityKind::Import => "multiple potential import sources",
717 AmbiguityKind::BuiltinAttr => "a name conflict with a builtin attribute",
718 AmbiguityKind::DeriveHelper => "a name conflict with a derive helper attribute",
719 AmbiguityKind::MacroRulesVsModularized => {
720 "a conflict between a `macro_rules` name and a non-`macro_rules` name from another module"
722 AmbiguityKind::GlobVsOuter => {
723 "a conflict between a name from a glob import and an outer scope during import or macro resolution"
725 AmbiguityKind::GlobVsGlob => "multiple glob imports of a name in the same module",
726 AmbiguityKind::GlobVsExpanded => {
727 "a conflict between a name from a glob import and a macro-expanded name in the same module during import or macro resolution"
729 AmbiguityKind::MoreExpandedVsOuter => {
730 "a conflict between a macro-expanded name and a less macro-expanded name from outer scope during import or macro resolution"
736 /// Miscellaneous bits of metadata for better ambiguity error reporting.
737 #[derive(Clone, Copy, PartialEq)]
738 enum AmbiguityErrorMisc {
745 struct AmbiguityError<'a> {
748 b1: &'a NameBinding<'a>,
749 b2: &'a NameBinding<'a>,
750 misc1: AmbiguityErrorMisc,
751 misc2: AmbiguityErrorMisc,
754 impl<'a> NameBinding<'a> {
755 fn module(&self) -> Option<Module<'a>> {
757 NameBindingKind::Module(module) => Some(module),
758 NameBindingKind::Import { binding, .. } => binding.module(),
763 fn res(&self) -> Res {
765 NameBindingKind::Res(res, _) => res,
766 NameBindingKind::Module(module) => module.res().unwrap(),
767 NameBindingKind::Import { binding, .. } => binding.res(),
771 fn is_ambiguity(&self) -> bool {
772 self.ambiguity.is_some()
774 NameBindingKind::Import { binding, .. } => binding.is_ambiguity(),
779 fn is_possibly_imported_variant(&self) -> bool {
781 NameBindingKind::Import { binding, .. } => binding.is_possibly_imported_variant(),
782 NameBindingKind::Res(
783 Res::Def(DefKind::Variant | DefKind::Ctor(CtorOf::Variant, ..), _),
786 NameBindingKind::Res(..) | NameBindingKind::Module(..) => false,
790 fn is_extern_crate(&self) -> bool {
792 NameBindingKind::Import {
793 import: &Import { kind: ImportKind::ExternCrate { .. }, .. },
796 NameBindingKind::Module(&ModuleData {
797 kind: ModuleKind::Def(DefKind::Mod, def_id, _),
799 }) => def_id.is_crate_root(),
804 fn is_import(&self) -> bool {
805 matches!(self.kind, NameBindingKind::Import { .. })
808 fn is_glob_import(&self) -> bool {
810 NameBindingKind::Import { import, .. } => import.is_glob(),
815 fn is_importable(&self) -> bool {
818 Res::Def(DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy, _)
822 fn macro_kind(&self) -> Option<MacroKind> {
823 self.res().macro_kind()
826 // Suppose that we resolved macro invocation with `invoc_parent_expansion` to binding `binding`
827 // at some expansion round `max(invoc, binding)` when they both emerged from macros.
828 // Then this function returns `true` if `self` may emerge from a macro *after* that
829 // in some later round and screw up our previously found resolution.
830 // See more detailed explanation in
831 // https://github.com/rust-lang/rust/pull/53778#issuecomment-419224049
834 invoc_parent_expansion: LocalExpnId,
835 binding: &NameBinding<'_>,
837 // self > max(invoc, binding) => !(self <= invoc || self <= binding)
838 // Expansions are partially ordered, so "may appear after" is an inversion of
839 // "certainly appears before or simultaneously" and includes unordered cases.
840 let self_parent_expansion = self.expansion;
841 let other_parent_expansion = binding.expansion;
842 let certainly_before_other_or_simultaneously =
843 other_parent_expansion.is_descendant_of(self_parent_expansion);
844 let certainly_before_invoc_or_simultaneously =
845 invoc_parent_expansion.is_descendant_of(self_parent_expansion);
846 !(certainly_before_other_or_simultaneously || certainly_before_invoc_or_simultaneously)
850 #[derive(Debug, Default, Clone)]
851 pub struct ExternPreludeEntry<'a> {
852 extern_crate_item: Option<&'a NameBinding<'a>>,
853 pub introduced_by_item: bool,
856 /// Used for better errors for E0773
857 enum BuiltinMacroState {
858 NotYetSeen(SyntaxExtensionKind),
863 resolutions: DeriveResolutions,
864 helper_attrs: Vec<(usize, Ident)>,
865 has_derive_copy: bool,
870 ext: Lrc<SyntaxExtension>,
874 /// The main resolver class.
876 /// This is the visitor that walks the whole crate.
877 pub struct Resolver<'a> {
878 session: &'a Session,
880 definitions: Definitions,
881 /// Item with a given `LocalDefId` was defined during macro expansion with ID `ExpnId`.
882 expn_that_defined: FxHashMap<LocalDefId, ExpnId>,
883 /// Reference span for definitions.
884 source_span: IndexVec<LocalDefId, Span>,
886 graph_root: Module<'a>,
888 prelude: Option<Module<'a>>,
889 extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'a>>,
891 /// N.B., this is used only for better diagnostics, not name resolution itself.
892 has_self: FxHashSet<DefId>,
894 /// Names of fields of an item `DefId` accessible with dot syntax.
895 /// Used for hints during error reporting.
896 field_names: FxHashMap<DefId, Vec<Spanned<Symbol>>>,
898 /// All imports known to succeed or fail.
899 determined_imports: Vec<&'a Import<'a>>,
901 /// All non-determined imports.
902 indeterminate_imports: Vec<&'a Import<'a>>,
904 // Spans for local variables found during pattern resolution.
905 // Used for suggestions during error reporting.
906 pat_span_map: NodeMap<Span>,
908 /// Resolutions for nodes that have a single resolution.
909 partial_res_map: NodeMap<PartialRes>,
910 /// Resolutions for import nodes, which have multiple resolutions in different namespaces.
911 import_res_map: NodeMap<PerNS<Option<Res>>>,
912 /// Resolutions for labels (node IDs of their corresponding blocks or loops).
913 label_res_map: NodeMap<NodeId>,
914 /// Resolutions for lifetimes.
915 lifetimes_res_map: NodeMap<LifetimeRes>,
916 /// Lifetime parameters that lowering will have to introduce.
917 extra_lifetime_params_map: NodeMap<Vec<(Ident, NodeId, LifetimeRes)>>,
919 /// `CrateNum` resolutions of `extern crate` items.
920 extern_crate_map: FxHashMap<LocalDefId, CrateNum>,
921 reexport_map: FxHashMap<LocalDefId, Vec<ModChild>>,
922 trait_map: NodeMap<Vec<TraitCandidate>>,
924 /// A map from nodes to anonymous modules.
925 /// Anonymous modules are pseudo-modules that are implicitly created around items
926 /// contained within blocks.
928 /// For example, if we have this:
936 /// There will be an anonymous module created around `g` with the ID of the
937 /// entry block for `f`.
938 block_map: NodeMap<Module<'a>>,
939 /// A fake module that contains no definition and no prelude. Used so that
940 /// some AST passes can generate identifiers that only resolve to local or
942 empty_module: Module<'a>,
943 module_map: FxHashMap<DefId, Module<'a>>,
944 binding_parent_modules: FxHashMap<Interned<'a, NameBinding<'a>>, Module<'a>>,
945 underscore_disambiguator: u32,
947 /// Maps glob imports to the names of items actually imported.
948 glob_map: FxHashMap<LocalDefId, FxHashSet<Symbol>>,
949 /// Visibilities in "lowered" form, for all entities that have them.
950 visibilities: FxHashMap<LocalDefId, ty::Visibility>,
951 has_pub_restricted: bool,
952 used_imports: FxHashSet<NodeId>,
953 maybe_unused_trait_imports: FxIndexSet<LocalDefId>,
954 maybe_unused_extern_crates: Vec<(LocalDefId, Span)>,
956 /// Privacy errors are delayed until the end in order to deduplicate them.
957 privacy_errors: Vec<PrivacyError<'a>>,
958 /// Ambiguity errors are delayed for deduplication.
959 ambiguity_errors: Vec<AmbiguityError<'a>>,
960 /// `use` injections are delayed for better placement and deduplication.
961 use_injections: Vec<UseError<'a>>,
962 /// Crate-local macro expanded `macro_export` referred to by a module-relative path.
963 macro_expanded_macro_export_errors: BTreeSet<(Span, Span)>,
965 arenas: &'a ResolverArenas<'a>,
966 dummy_binding: &'a NameBinding<'a>,
968 crate_loader: CrateLoader<'a>,
969 macro_names: FxHashSet<Ident>,
970 builtin_macros: FxHashMap<Symbol, BuiltinMacroState>,
971 /// A small map keeping true kinds of built-in macros that appear to be fn-like on
972 /// the surface (`macro` items in libcore), but are actually attributes or derives.
973 builtin_macro_kinds: FxHashMap<LocalDefId, MacroKind>,
974 registered_attrs: FxHashSet<Ident>,
975 registered_tools: RegisteredTools,
976 macro_use_prelude: FxHashMap<Symbol, &'a NameBinding<'a>>,
977 macro_map: FxHashMap<DefId, MacroData>,
978 dummy_ext_bang: Lrc<SyntaxExtension>,
979 dummy_ext_derive: Lrc<SyntaxExtension>,
980 non_macro_attr: Lrc<SyntaxExtension>,
981 local_macro_def_scopes: FxHashMap<LocalDefId, Module<'a>>,
982 ast_transform_scopes: FxHashMap<LocalExpnId, Module<'a>>,
983 unused_macros: FxHashMap<LocalDefId, (NodeId, Ident)>,
984 unused_macro_rules: FxHashMap<(LocalDefId, usize), (Ident, Span)>,
985 proc_macro_stubs: FxHashSet<LocalDefId>,
986 /// Traces collected during macro resolution and validated when it's complete.
987 single_segment_macro_resolutions:
988 Vec<(Ident, MacroKind, ParentScope<'a>, Option<&'a NameBinding<'a>>)>,
989 multi_segment_macro_resolutions:
990 Vec<(Vec<Segment>, Span, MacroKind, ParentScope<'a>, Option<Res>)>,
991 builtin_attrs: Vec<(Ident, ParentScope<'a>)>,
992 /// `derive(Copy)` marks items they are applied to so they are treated specially later.
993 /// Derive macros cannot modify the item themselves and have to store the markers in the global
994 /// context, so they attach the markers to derive container IDs using this resolver table.
995 containers_deriving_copy: FxHashSet<LocalExpnId>,
996 /// Parent scopes in which the macros were invoked.
997 /// FIXME: `derives` are missing in these parent scopes and need to be taken from elsewhere.
998 invocation_parent_scopes: FxHashMap<LocalExpnId, ParentScope<'a>>,
999 /// `macro_rules` scopes *produced* by expanding the macro invocations,
1000 /// include all the `macro_rules` items and other invocations generated by them.
1001 output_macro_rules_scopes: FxHashMap<LocalExpnId, MacroRulesScopeRef<'a>>,
1002 /// `macro_rules` scopes produced by `macro_rules` item definitions.
1003 macro_rules_scopes: FxHashMap<LocalDefId, MacroRulesScopeRef<'a>>,
1004 /// Helper attributes that are in scope for the given expansion.
1005 helper_attrs: FxHashMap<LocalExpnId, Vec<Ident>>,
1006 /// Ready or in-progress results of resolving paths inside the `#[derive(...)]` attribute
1007 /// with the given `ExpnId`.
1008 derive_data: FxHashMap<LocalExpnId, DeriveData>,
1010 /// Avoid duplicated errors for "name already defined".
1011 name_already_seen: FxHashMap<Symbol, Span>,
1013 potentially_unused_imports: Vec<&'a Import<'a>>,
1015 /// Table for mapping struct IDs into struct constructor IDs,
1016 /// it's not used during normal resolution, only for better error reporting.
1017 /// Also includes of list of each fields visibility
1018 struct_constructors: DefIdMap<(Res, ty::Visibility, Vec<ty::Visibility>)>,
1020 /// Features enabled for this crate.
1021 active_features: FxHashSet<Symbol>,
1023 lint_buffer: LintBuffer,
1025 next_node_id: NodeId,
1027 node_id_to_def_id: FxHashMap<ast::NodeId, LocalDefId>,
1028 def_id_to_node_id: IndexVec<LocalDefId, ast::NodeId>,
1030 /// Indices of unnamed struct or variant fields with unresolved attributes.
1031 placeholder_field_indices: FxHashMap<NodeId, usize>,
1032 /// When collecting definitions from an AST fragment produced by a macro invocation `ExpnId`
1033 /// we know what parent node that fragment should be attached to thanks to this table,
1034 /// and how the `impl Trait` fragments were introduced.
1035 invocation_parents: FxHashMap<LocalExpnId, (LocalDefId, ImplTraitContext)>,
1037 /// Some way to know that we are in a *trait* impl in `visit_assoc_item`.
1038 /// FIXME: Replace with a more general AST map (together with some other fields).
1039 trait_impl_items: FxHashSet<LocalDefId>,
1041 legacy_const_generic_args: FxHashMap<DefId, Option<Vec<usize>>>,
1042 /// Amount of lifetime parameters for each item in the crate.
1043 item_generics_num_lifetimes: FxHashMap<LocalDefId, usize>,
1045 main_def: Option<MainDefinition>,
1046 trait_impls: FxIndexMap<DefId, Vec<LocalDefId>>,
1047 /// A list of proc macro LocalDefIds, written out in the order in which
1048 /// they are declared in the static array generated by proc_macro_harness.
1049 proc_macros: Vec<NodeId>,
1050 confused_type_with_std_module: FxHashMap<Span, Span>,
1052 access_levels: AccessLevels,
1055 /// Nothing really interesting here; it just provides memory for the rest of the crate.
1057 pub struct ResolverArenas<'a> {
1058 modules: TypedArena<ModuleData<'a>>,
1059 local_modules: RefCell<Vec<Module<'a>>>,
1060 imports: TypedArena<Import<'a>>,
1061 name_resolutions: TypedArena<RefCell<NameResolution<'a>>>,
1062 ast_paths: TypedArena<ast::Path>,
1063 dropless: DroplessArena,
1066 impl<'a> ResolverArenas<'a> {
1069 parent: Option<Module<'a>>,
1073 no_implicit_prelude: bool,
1074 module_map: &mut FxHashMap<DefId, Module<'a>>,
1077 self.modules.alloc(ModuleData::new(parent, kind, expn_id, span, no_implicit_prelude));
1078 let def_id = module.opt_def_id();
1079 if def_id.map_or(true, |def_id| def_id.is_local()) {
1080 self.local_modules.borrow_mut().push(module);
1082 if let Some(def_id) = def_id {
1083 module_map.insert(def_id, module);
1087 fn local_modules(&'a self) -> std::cell::Ref<'a, Vec<Module<'a>>> {
1088 self.local_modules.borrow()
1090 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1091 self.dropless.alloc(name_binding)
1093 fn alloc_import(&'a self, import: Import<'a>) -> &'a Import<'_> {
1094 self.imports.alloc(import)
1096 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1097 self.name_resolutions.alloc(Default::default())
1099 fn alloc_macro_rules_scope(&'a self, scope: MacroRulesScope<'a>) -> MacroRulesScopeRef<'a> {
1100 Interned::new_unchecked(self.dropless.alloc(Cell::new(scope)))
1102 fn alloc_macro_rules_binding(
1104 binding: MacroRulesBinding<'a>,
1105 ) -> &'a MacroRulesBinding<'a> {
1106 self.dropless.alloc(binding)
1108 fn alloc_ast_paths(&'a self, paths: &[ast::Path]) -> &'a [ast::Path] {
1109 self.ast_paths.alloc_from_iter(paths.iter().cloned())
1111 fn alloc_pattern_spans(&'a self, spans: impl Iterator<Item = Span>) -> &'a [Span] {
1112 self.dropless.alloc_from_iter(spans)
1116 impl<'a> AsMut<Resolver<'a>> for Resolver<'a> {
1117 fn as_mut(&mut self) -> &mut Resolver<'a> {
1122 impl<'a, 'b> DefIdTree for &'a Resolver<'b> {
1124 fn opt_parent(self, id: DefId) -> Option<DefId> {
1125 match id.as_local() {
1126 Some(id) => self.definitions.def_key(id).parent,
1127 None => self.cstore().def_key(id).parent,
1129 .map(|index| DefId { index, ..id })
1134 fn opt_local_def_id(&self, node: NodeId) -> Option<LocalDefId> {
1135 self.node_id_to_def_id.get(&node).copied()
1138 pub fn local_def_id(&self, node: NodeId) -> LocalDefId {
1139 self.opt_local_def_id(node).unwrap_or_else(|| panic!("no entry for node id: `{:?}`", node))
1142 /// Adds a definition with a parent definition.
1146 node_id: ast::NodeId,
1152 !self.node_id_to_def_id.contains_key(&node_id),
1153 "adding a def'n for node-id {:?} and data {:?} but a previous def'n exists: {:?}",
1156 self.definitions.def_key(self.node_id_to_def_id[&node_id]),
1159 let def_id = self.definitions.create_def(parent, data);
1161 // Create the definition.
1162 if expn_id != ExpnId::root() {
1163 self.expn_that_defined.insert(def_id, expn_id);
1166 // A relative span's parent must be an absolute span.
1167 debug_assert_eq!(span.data_untracked().parent, None);
1168 let _id = self.source_span.push(span);
1169 debug_assert_eq!(_id, def_id);
1171 // Some things for which we allocate `LocalDefId`s don't correspond to
1172 // anything in the AST, so they don't have a `NodeId`. For these cases
1173 // we don't need a mapping from `NodeId` to `LocalDefId`.
1174 if node_id != ast::DUMMY_NODE_ID {
1175 debug!("create_def: def_id_to_node_id[{:?}] <-> {:?}", def_id, node_id);
1176 self.node_id_to_def_id.insert(node_id, def_id);
1178 assert_eq!(self.def_id_to_node_id.push(node_id), def_id);
1183 fn item_generics_num_lifetimes(&self, def_id: DefId) -> usize {
1184 if let Some(def_id) = def_id.as_local() {
1185 self.item_generics_num_lifetimes[&def_id]
1187 self.cstore().item_generics_num_lifetimes(def_id, self.session)
1192 impl<'a> Resolver<'a> {
1194 session: &'a Session,
1197 metadata_loader: Box<MetadataLoaderDyn>,
1198 arenas: &'a ResolverArenas<'a>,
1200 let root_def_id = CRATE_DEF_ID.to_def_id();
1201 let mut module_map = FxHashMap::default();
1202 let graph_root = arenas.new_module(
1204 ModuleKind::Def(DefKind::Mod, root_def_id, kw::Empty),
1206 krate.spans.inner_span,
1207 session.contains_name(&krate.attrs, sym::no_implicit_prelude),
1210 let empty_module = arenas.new_module(
1212 ModuleKind::Def(DefKind::Mod, root_def_id, kw::Empty),
1216 &mut FxHashMap::default(),
1219 let definitions = Definitions::new(session.local_stable_crate_id());
1221 let mut visibilities = FxHashMap::default();
1222 visibilities.insert(CRATE_DEF_ID, ty::Visibility::Public);
1224 let mut def_id_to_node_id = IndexVec::default();
1225 assert_eq!(def_id_to_node_id.push(CRATE_NODE_ID), CRATE_DEF_ID);
1226 let mut node_id_to_def_id = FxHashMap::default();
1227 node_id_to_def_id.insert(CRATE_NODE_ID, CRATE_DEF_ID);
1229 let mut invocation_parents = FxHashMap::default();
1230 invocation_parents.insert(LocalExpnId::ROOT, (CRATE_DEF_ID, ImplTraitContext::Existential));
1232 let mut source_span = IndexVec::default();
1233 let _id = source_span.push(krate.spans.inner_span);
1234 debug_assert_eq!(_id, CRATE_DEF_ID);
1236 let mut extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'_>> = session
1240 .filter(|(_, entry)| entry.add_prelude)
1241 .map(|(name, _)| (Ident::from_str(name), Default::default()))
1244 if !session.contains_name(&krate.attrs, sym::no_core) {
1245 extern_prelude.insert(Ident::with_dummy_span(sym::core), Default::default());
1246 if !session.contains_name(&krate.attrs, sym::no_std) {
1247 extern_prelude.insert(Ident::with_dummy_span(sym::std), Default::default());
1251 let (registered_attrs, registered_tools) =
1252 macros::registered_attrs_and_tools(session, &krate.attrs);
1254 let features = session.features_untracked();
1256 let mut resolver = Resolver {
1260 expn_that_defined: Default::default(),
1263 // The outermost module has def ID 0; this is not reflected in the
1269 has_self: FxHashSet::default(),
1270 field_names: FxHashMap::default(),
1272 determined_imports: Vec::new(),
1273 indeterminate_imports: Vec::new(),
1275 pat_span_map: Default::default(),
1276 partial_res_map: Default::default(),
1277 import_res_map: Default::default(),
1278 label_res_map: Default::default(),
1279 lifetimes_res_map: Default::default(),
1280 extra_lifetime_params_map: Default::default(),
1281 extern_crate_map: Default::default(),
1282 reexport_map: FxHashMap::default(),
1283 trait_map: NodeMap::default(),
1284 underscore_disambiguator: 0,
1287 block_map: Default::default(),
1288 binding_parent_modules: FxHashMap::default(),
1289 ast_transform_scopes: FxHashMap::default(),
1291 glob_map: Default::default(),
1293 has_pub_restricted: false,
1294 used_imports: FxHashSet::default(),
1295 maybe_unused_trait_imports: Default::default(),
1296 maybe_unused_extern_crates: Vec::new(),
1298 privacy_errors: Vec::new(),
1299 ambiguity_errors: Vec::new(),
1300 use_injections: Vec::new(),
1301 macro_expanded_macro_export_errors: BTreeSet::new(),
1304 dummy_binding: arenas.alloc_name_binding(NameBinding {
1305 kind: NameBindingKind::Res(Res::Err, false),
1307 expansion: LocalExpnId::ROOT,
1309 vis: ty::Visibility::Public,
1312 crate_loader: CrateLoader::new(session, metadata_loader, crate_name),
1313 macro_names: FxHashSet::default(),
1314 builtin_macros: Default::default(),
1315 builtin_macro_kinds: Default::default(),
1318 macro_use_prelude: FxHashMap::default(),
1319 macro_map: FxHashMap::default(),
1320 dummy_ext_bang: Lrc::new(SyntaxExtension::dummy_bang(session.edition())),
1321 dummy_ext_derive: Lrc::new(SyntaxExtension::dummy_derive(session.edition())),
1322 non_macro_attr: Lrc::new(SyntaxExtension::non_macro_attr(session.edition())),
1323 invocation_parent_scopes: Default::default(),
1324 output_macro_rules_scopes: Default::default(),
1325 macro_rules_scopes: Default::default(),
1326 helper_attrs: Default::default(),
1327 derive_data: Default::default(),
1328 local_macro_def_scopes: FxHashMap::default(),
1329 name_already_seen: FxHashMap::default(),
1330 potentially_unused_imports: Vec::new(),
1331 struct_constructors: Default::default(),
1332 unused_macros: Default::default(),
1333 unused_macro_rules: Default::default(),
1334 proc_macro_stubs: Default::default(),
1335 single_segment_macro_resolutions: Default::default(),
1336 multi_segment_macro_resolutions: Default::default(),
1337 builtin_attrs: Default::default(),
1338 containers_deriving_copy: Default::default(),
1339 active_features: features
1340 .declared_lib_features
1342 .map(|(feat, ..)| *feat)
1343 .chain(features.declared_lang_features.iter().map(|(feat, ..)| *feat))
1345 lint_buffer: LintBuffer::default(),
1346 next_node_id: CRATE_NODE_ID,
1349 placeholder_field_indices: Default::default(),
1351 trait_impl_items: Default::default(),
1352 legacy_const_generic_args: Default::default(),
1353 item_generics_num_lifetimes: Default::default(),
1354 main_def: Default::default(),
1355 trait_impls: Default::default(),
1356 proc_macros: Default::default(),
1357 confused_type_with_std_module: Default::default(),
1358 access_levels: Default::default(),
1361 let root_parent_scope = ParentScope::module(graph_root, &resolver);
1362 resolver.invocation_parent_scopes.insert(LocalExpnId::ROOT, root_parent_scope);
1369 parent: Option<Module<'a>>,
1373 no_implicit_prelude: bool,
1375 let module_map = &mut self.module_map;
1376 self.arenas.new_module(parent, kind, expn_id, span, no_implicit_prelude, module_map)
1379 pub fn next_node_id(&mut self) -> NodeId {
1380 let start = self.next_node_id;
1381 let next = start.as_u32().checked_add(1).expect("input too large; ran out of NodeIds");
1382 self.next_node_id = ast::NodeId::from_u32(next);
1386 pub fn next_node_ids(&mut self, count: usize) -> std::ops::Range<NodeId> {
1387 let start = self.next_node_id;
1388 let end = start.as_usize().checked_add(count).expect("input too large; ran out of NodeIds");
1389 self.next_node_id = ast::NodeId::from_usize(end);
1390 start..self.next_node_id
1393 pub fn lint_buffer(&mut self) -> &mut LintBuffer {
1394 &mut self.lint_buffer
1397 pub fn arenas() -> ResolverArenas<'a> {
1401 pub fn into_outputs(
1403 ) -> (Definitions, Box<CrateStoreDyn>, ResolverOutputs, ty::ResolverAstLowering) {
1404 let proc_macros = self.proc_macros.iter().map(|id| self.local_def_id(*id)).collect();
1405 let definitions = self.definitions;
1406 let cstore = Box::new(self.crate_loader.into_cstore());
1407 let source_span = self.source_span;
1408 let expn_that_defined = self.expn_that_defined;
1409 let visibilities = self.visibilities;
1410 let has_pub_restricted = self.has_pub_restricted;
1411 let extern_crate_map = self.extern_crate_map;
1412 let reexport_map = self.reexport_map;
1413 let maybe_unused_trait_imports = self.maybe_unused_trait_imports;
1414 let maybe_unused_extern_crates = self.maybe_unused_extern_crates;
1415 let glob_map = self.glob_map;
1416 let main_def = self.main_def;
1417 let confused_type_with_std_module = self.confused_type_with_std_module;
1418 let access_levels = self.access_levels;
1419 let resolutions = ResolverOutputs {
1428 maybe_unused_trait_imports,
1429 maybe_unused_extern_crates,
1430 extern_prelude: self
1433 .map(|(ident, entry)| (ident.name, entry.introduced_by_item))
1436 trait_impls: self.trait_impls,
1438 confused_type_with_std_module,
1439 registered_tools: self.registered_tools,
1441 let resolutions_lowering = ty::ResolverAstLowering {
1442 legacy_const_generic_args: self.legacy_const_generic_args,
1443 partial_res_map: self.partial_res_map,
1444 import_res_map: self.import_res_map,
1445 label_res_map: self.label_res_map,
1446 lifetimes_res_map: self.lifetimes_res_map,
1447 extra_lifetime_params_map: self.extra_lifetime_params_map,
1448 next_node_id: self.next_node_id,
1449 node_id_to_def_id: self.node_id_to_def_id,
1450 def_id_to_node_id: self.def_id_to_node_id,
1451 trait_map: self.trait_map,
1452 builtin_macro_kinds: self.builtin_macro_kinds,
1454 (definitions, cstore, resolutions, resolutions_lowering)
1457 pub fn clone_outputs(
1459 ) -> (Definitions, Box<CrateStoreDyn>, ResolverOutputs, ty::ResolverAstLowering) {
1460 let proc_macros = self.proc_macros.iter().map(|id| self.local_def_id(*id)).collect();
1461 let definitions = self.definitions.clone();
1462 let cstore = Box::new(self.cstore().clone());
1463 let resolutions = ResolverOutputs {
1464 source_span: self.source_span.clone(),
1465 expn_that_defined: self.expn_that_defined.clone(),
1466 visibilities: self.visibilities.clone(),
1467 has_pub_restricted: self.has_pub_restricted,
1468 extern_crate_map: self.extern_crate_map.clone(),
1469 reexport_map: self.reexport_map.clone(),
1470 glob_map: self.glob_map.clone(),
1471 maybe_unused_trait_imports: self.maybe_unused_trait_imports.clone(),
1472 maybe_unused_extern_crates: self.maybe_unused_extern_crates.clone(),
1473 extern_prelude: self
1476 .map(|(ident, entry)| (ident.name, entry.introduced_by_item))
1478 main_def: self.main_def,
1479 trait_impls: self.trait_impls.clone(),
1481 confused_type_with_std_module: self.confused_type_with_std_module.clone(),
1482 registered_tools: self.registered_tools.clone(),
1483 access_levels: self.access_levels.clone(),
1485 let resolutions_lowering = ty::ResolverAstLowering {
1486 legacy_const_generic_args: self.legacy_const_generic_args.clone(),
1487 partial_res_map: self.partial_res_map.clone(),
1488 import_res_map: self.import_res_map.clone(),
1489 label_res_map: self.label_res_map.clone(),
1490 lifetimes_res_map: self.lifetimes_res_map.clone(),
1491 extra_lifetime_params_map: self.extra_lifetime_params_map.clone(),
1492 next_node_id: self.next_node_id.clone(),
1493 node_id_to_def_id: self.node_id_to_def_id.clone(),
1494 def_id_to_node_id: self.def_id_to_node_id.clone(),
1495 trait_map: self.trait_map.clone(),
1496 builtin_macro_kinds: self.builtin_macro_kinds.clone(),
1498 (definitions, cstore, resolutions, resolutions_lowering)
1501 fn create_stable_hashing_context(&self) -> StableHashingContext<'_> {
1502 StableHashingContext::new(
1505 self.crate_loader.cstore(),
1510 pub fn cstore(&self) -> &CStore {
1511 self.crate_loader.cstore()
1514 fn dummy_ext(&self, macro_kind: MacroKind) -> Lrc<SyntaxExtension> {
1516 MacroKind::Bang => self.dummy_ext_bang.clone(),
1517 MacroKind::Derive => self.dummy_ext_derive.clone(),
1518 MacroKind::Attr => self.non_macro_attr.clone(),
1522 /// Runs the function on each namespace.
1523 fn per_ns<F: FnMut(&mut Self, Namespace)>(&mut self, mut f: F) {
1529 fn is_builtin_macro(&mut self, res: Res) -> bool {
1530 self.get_macro(res).map_or(false, |macro_data| macro_data.ext.builtin_name.is_some())
1533 fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
1535 match ctxt.outer_expn_data().macro_def_id {
1536 Some(def_id) => return def_id,
1537 None => ctxt.remove_mark(),
1542 /// Entry point to crate resolution.
1543 pub fn resolve_crate(&mut self, krate: &Crate) {
1544 self.session.time("resolve_crate", || {
1545 self.session.time("finalize_imports", || ImportResolver { r: self }.finalize_imports());
1546 self.session.time("resolve_access_levels", || {
1547 AccessLevelsVisitor::compute_access_levels(self, krate)
1549 self.session.time("finalize_macro_resolutions", || self.finalize_macro_resolutions());
1550 self.session.time("late_resolve_crate", || self.late_resolve_crate(krate));
1551 self.session.time("resolve_main", || self.resolve_main());
1552 self.session.time("resolve_check_unused", || self.check_unused(krate));
1553 self.session.time("resolve_report_errors", || self.report_errors(krate));
1554 self.session.time("resolve_postprocess", || self.crate_loader.postprocess(krate));
1558 pub fn traits_in_scope(
1560 current_trait: Option<Module<'a>>,
1561 parent_scope: &ParentScope<'a>,
1562 ctxt: SyntaxContext,
1563 assoc_item: Option<(Symbol, Namespace)>,
1564 ) -> Vec<TraitCandidate> {
1565 let mut found_traits = Vec::new();
1567 if let Some(module) = current_trait {
1568 if self.trait_may_have_item(Some(module), assoc_item) {
1569 let def_id = module.def_id();
1570 found_traits.push(TraitCandidate { def_id, import_ids: smallvec![] });
1574 self.visit_scopes(ScopeSet::All(TypeNS, false), parent_scope, ctxt, |this, scope, _, _| {
1576 Scope::Module(module, _) => {
1577 this.traits_in_module(module, assoc_item, &mut found_traits);
1579 Scope::StdLibPrelude => {
1580 if let Some(module) = this.prelude {
1581 this.traits_in_module(module, assoc_item, &mut found_traits);
1584 Scope::ExternPrelude | Scope::ToolPrelude | Scope::BuiltinTypes => {}
1585 _ => unreachable!(),
1593 fn traits_in_module(
1596 assoc_item: Option<(Symbol, Namespace)>,
1597 found_traits: &mut Vec<TraitCandidate>,
1599 module.ensure_traits(self);
1600 let traits = module.traits.borrow();
1601 for (trait_name, trait_binding) in traits.as_ref().unwrap().iter() {
1602 if self.trait_may_have_item(trait_binding.module(), assoc_item) {
1603 let def_id = trait_binding.res().def_id();
1604 let import_ids = self.find_transitive_imports(&trait_binding.kind, *trait_name);
1605 found_traits.push(TraitCandidate { def_id, import_ids });
1610 // List of traits in scope is pruned on best effort basis. We reject traits not having an
1611 // associated item with the given name and namespace (if specified). This is a conservative
1612 // optimization, proper hygienic type-based resolution of associated items is done in typeck.
1613 // We don't reject trait aliases (`trait_module == None`) because we don't have access to their
1614 // associated items.
1615 fn trait_may_have_item(
1617 trait_module: Option<Module<'a>>,
1618 assoc_item: Option<(Symbol, Namespace)>,
1620 match (trait_module, assoc_item) {
1621 (Some(trait_module), Some((name, ns))) => {
1622 self.resolutions(trait_module).borrow().iter().any(|resolution| {
1623 let (&BindingKey { ident: assoc_ident, ns: assoc_ns, .. }, _) = resolution;
1624 assoc_ns == ns && assoc_ident.name == name
1631 fn find_transitive_imports(
1633 mut kind: &NameBindingKind<'_>,
1635 ) -> SmallVec<[LocalDefId; 1]> {
1636 let mut import_ids = smallvec![];
1637 while let NameBindingKind::Import { import, binding, .. } = kind {
1638 let id = self.local_def_id(import.id);
1639 self.maybe_unused_trait_imports.insert(id);
1640 self.add_to_glob_map(&import, trait_name);
1641 import_ids.push(id);
1642 kind = &binding.kind;
1647 fn new_key(&mut self, ident: Ident, ns: Namespace) -> BindingKey {
1648 let ident = ident.normalize_to_macros_2_0();
1649 let disambiguator = if ident.name == kw::Underscore {
1650 self.underscore_disambiguator += 1;
1651 self.underscore_disambiguator
1655 BindingKey { ident, ns, disambiguator }
1658 fn resolutions(&mut self, module: Module<'a>) -> &'a Resolutions<'a> {
1659 if module.populate_on_access.get() {
1660 module.populate_on_access.set(false);
1661 self.build_reduced_graph_external(module);
1663 &module.lazy_resolutions
1670 ) -> &'a RefCell<NameResolution<'a>> {
1672 .resolutions(module)
1675 .or_insert_with(|| self.arenas.alloc_name_resolution())
1681 used_binding: &'a NameBinding<'a>,
1682 is_lexical_scope: bool,
1684 if let Some((b2, kind)) = used_binding.ambiguity {
1685 self.ambiguity_errors.push(AmbiguityError {
1690 misc1: AmbiguityErrorMisc::None,
1691 misc2: AmbiguityErrorMisc::None,
1694 if let NameBindingKind::Import { import, binding, ref used } = used_binding.kind {
1695 // Avoid marking `extern crate` items that refer to a name from extern prelude,
1696 // but not introduce it, as used if they are accessed from lexical scope.
1697 if is_lexical_scope {
1698 if let Some(entry) = self.extern_prelude.get(&ident.normalize_to_macros_2_0()) {
1699 if let Some(crate_item) = entry.extern_crate_item {
1700 if ptr::eq(used_binding, crate_item) && !entry.introduced_by_item {
1707 import.used.set(true);
1708 self.used_imports.insert(import.id);
1709 self.add_to_glob_map(&import, ident);
1710 self.record_use(ident, binding, false);
1715 fn add_to_glob_map(&mut self, import: &Import<'_>, ident: Ident) {
1716 if import.is_glob() {
1717 let def_id = self.local_def_id(import.id);
1718 self.glob_map.entry(def_id).or_default().insert(ident.name);
1722 fn resolve_crate_root(&mut self, ident: Ident) -> Module<'a> {
1723 debug!("resolve_crate_root({:?})", ident);
1724 let mut ctxt = ident.span.ctxt();
1725 let mark = if ident.name == kw::DollarCrate {
1726 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
1727 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
1728 // as described in `SyntaxContext::apply_mark`, so we ignore prepended opaque marks.
1729 // FIXME: This is only a guess and it doesn't work correctly for `macro_rules!`
1730 // definitions actually produced by `macro` and `macro` definitions produced by
1731 // `macro_rules!`, but at least such configurations are not stable yet.
1732 ctxt = ctxt.normalize_to_macro_rules();
1734 "resolve_crate_root: marks={:?}",
1735 ctxt.marks().into_iter().map(|(i, t)| (i.expn_data(), t)).collect::<Vec<_>>()
1737 let mut iter = ctxt.marks().into_iter().rev().peekable();
1738 let mut result = None;
1739 // Find the last opaque mark from the end if it exists.
1740 while let Some(&(mark, transparency)) = iter.peek() {
1741 if transparency == Transparency::Opaque {
1742 result = Some(mark);
1749 "resolve_crate_root: found opaque mark {:?} {:?}",
1751 result.map(|r| r.expn_data())
1753 // Then find the last semi-transparent mark from the end if it exists.
1754 for (mark, transparency) in iter {
1755 if transparency == Transparency::SemiTransparent {
1756 result = Some(mark);
1762 "resolve_crate_root: found semi-transparent mark {:?} {:?}",
1764 result.map(|r| r.expn_data())
1768 debug!("resolve_crate_root: not DollarCrate");
1769 ctxt = ctxt.normalize_to_macros_2_0();
1770 ctxt.adjust(ExpnId::root())
1772 let module = match mark {
1773 Some(def) => self.expn_def_scope(def),
1776 "resolve_crate_root({:?}): found no mark (ident.span = {:?})",
1779 return self.graph_root;
1782 let module = self.expect_module(
1783 module.opt_def_id().map_or(LOCAL_CRATE, |def_id| def_id.krate).as_def_id(),
1786 "resolve_crate_root({:?}): got module {:?} ({:?}) (ident.span = {:?})",
1795 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
1796 let mut module = self.expect_module(module.nearest_parent_mod());
1797 while module.span.ctxt().normalize_to_macros_2_0() != *ctxt {
1798 let parent = module.parent.unwrap_or_else(|| self.expn_def_scope(ctxt.remove_mark()));
1799 module = self.expect_module(parent.nearest_parent_mod());
1804 fn record_partial_res(&mut self, node_id: NodeId, resolution: PartialRes) {
1805 debug!("(recording res) recording {:?} for {}", resolution, node_id);
1806 if let Some(prev_res) = self.partial_res_map.insert(node_id, resolution) {
1807 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
1811 fn record_pat_span(&mut self, node: NodeId, span: Span) {
1812 debug!("(recording pat) recording {:?} for {:?}", node, span);
1813 self.pat_span_map.insert(node, span);
1816 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
1817 vis.is_accessible_from(module.nearest_parent_mod(), self)
1820 fn set_binding_parent_module(&mut self, binding: &'a NameBinding<'a>, module: Module<'a>) {
1821 if let Some(old_module) =
1822 self.binding_parent_modules.insert(Interned::new_unchecked(binding), module)
1824 if !ptr::eq(module, old_module) {
1825 span_bug!(binding.span, "parent module is reset for binding");
1830 fn disambiguate_macro_rules_vs_modularized(
1832 macro_rules: &'a NameBinding<'a>,
1833 modularized: &'a NameBinding<'a>,
1835 // Some non-controversial subset of ambiguities "modularized macro name" vs "macro_rules"
1836 // is disambiguated to mitigate regressions from macro modularization.
1837 // Scoping for `macro_rules` behaves like scoping for `let` at module level, in general.
1839 self.binding_parent_modules.get(&Interned::new_unchecked(macro_rules)),
1840 self.binding_parent_modules.get(&Interned::new_unchecked(modularized)),
1842 (Some(macro_rules), Some(modularized)) => {
1843 macro_rules.nearest_parent_mod() == modularized.nearest_parent_mod()
1844 && modularized.is_ancestor_of(macro_rules)
1850 fn extern_prelude_get(&mut self, ident: Ident, finalize: bool) -> Option<&'a NameBinding<'a>> {
1851 if ident.is_path_segment_keyword() {
1852 // Make sure `self`, `super` etc produce an error when passed to here.
1855 self.extern_prelude.get(&ident.normalize_to_macros_2_0()).cloned().and_then(|entry| {
1856 if let Some(binding) = entry.extern_crate_item {
1857 if finalize && entry.introduced_by_item {
1858 self.record_use(ident, binding, false);
1862 let crate_id = if finalize {
1863 let Some(crate_id) =
1864 self.crate_loader.process_path_extern(ident.name, ident.span) else { return Some(self.dummy_binding); };
1867 self.crate_loader.maybe_process_path_extern(ident.name)?
1869 let crate_root = self.expect_module(crate_id.as_def_id());
1871 (crate_root, ty::Visibility::Public, DUMMY_SP, LocalExpnId::ROOT)
1872 .to_name_binding(self.arenas),
1878 /// Rustdoc uses this to resolve doc link paths in a recoverable way. `PathResult<'a>`
1879 /// isn't something that can be returned because it can't be made to live that long,
1880 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
1881 /// just that an error occurred.
1882 pub fn resolve_rustdoc_path(
1886 mut parent_scope: ParentScope<'a>,
1889 Vec::from_iter(path_str.split("::").map(Ident::from_str).map(Segment::from_ident));
1890 if let Some(segment) = segments.first_mut() {
1891 if segment.ident.name == kw::Crate {
1892 // FIXME: `resolve_path` always resolves `crate` to the current crate root, but
1893 // rustdoc wants it to resolve to the `parent_scope`'s crate root. This trick of
1894 // replacing `crate` with `self` and changing the current module should achieve
1896 segment.ident.name = kw::SelfLower;
1897 parent_scope.module =
1898 self.expect_module(parent_scope.module.def_id().krate.as_def_id());
1899 } else if segment.ident.name == kw::Empty {
1900 segment.ident.name = kw::PathRoot;
1904 match self.maybe_resolve_path(&segments, Some(ns), &parent_scope) {
1905 PathResult::Module(ModuleOrUniformRoot::Module(module)) => Some(module.res().unwrap()),
1906 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 => {
1907 Some(path_res.base_res())
1909 PathResult::Module(ModuleOrUniformRoot::ExternPrelude)
1910 | PathResult::NonModule(..)
1911 | PathResult::Failed { .. } => None,
1912 PathResult::Module(..) | PathResult::Indeterminate => unreachable!(),
1917 /// For local modules returns only reexports, for external modules returns all children.
1918 pub fn module_children_or_reexports(&self, def_id: DefId) -> Vec<ModChild> {
1919 if let Some(def_id) = def_id.as_local() {
1920 self.reexport_map.get(&def_id).cloned().unwrap_or_default()
1922 self.cstore().module_children_untracked(def_id, self.session)
1927 pub fn macro_rules_scope(&self, def_id: LocalDefId) -> (MacroRulesScopeRef<'a>, Res) {
1928 let scope = *self.macro_rules_scopes.get(&def_id).expect("not a `macro_rules` item");
1930 MacroRulesScope::Binding(mb) => (scope, mb.binding.res()),
1931 _ => unreachable!(),
1935 /// Retrieves the span of the given `DefId` if `DefId` is in the local crate.
1937 pub fn opt_span(&self, def_id: DefId) -> Option<Span> {
1938 def_id.as_local().map(|def_id| self.source_span[def_id])
1941 /// Checks if an expression refers to a function marked with
1942 /// `#[rustc_legacy_const_generics]` and returns the argument index list
1943 /// from the attribute.
1944 pub fn legacy_const_generic_args(&mut self, expr: &Expr) -> Option<Vec<usize>> {
1945 if let ExprKind::Path(None, path) = &expr.kind {
1946 // Don't perform legacy const generics rewriting if the path already
1947 // has generic arguments.
1948 if path.segments.last().unwrap().args.is_some() {
1952 let partial_res = self.partial_res_map.get(&expr.id)?;
1953 if partial_res.unresolved_segments() != 0 {
1957 if let Res::Def(def::DefKind::Fn, def_id) = partial_res.base_res() {
1958 // We only support cross-crate argument rewriting. Uses
1959 // within the same crate should be updated to use the new
1960 // const generics style.
1961 if def_id.is_local() {
1965 if let Some(v) = self.legacy_const_generic_args.get(&def_id) {
1971 .item_attrs_untracked(def_id, self.session)
1972 .find(|a| a.has_name(sym::rustc_legacy_const_generics))?;
1973 let mut ret = Vec::new();
1974 for meta in attr.meta_item_list()? {
1975 match meta.literal()?.kind {
1976 LitKind::Int(a, _) => ret.push(a as usize),
1977 _ => panic!("invalid arg index"),
1980 // Cache the lookup to avoid parsing attributes for an iterm multiple times.
1981 self.legacy_const_generic_args.insert(def_id, Some(ret.clone()));
1988 fn resolve_main(&mut self) {
1989 let module = self.graph_root;
1990 let ident = Ident::with_dummy_span(sym::main);
1991 let parent_scope = &ParentScope::module(module, self);
1993 let Ok(name_binding) = self.maybe_resolve_ident_in_module(
1994 ModuleOrUniformRoot::Module(module),
2002 let res = name_binding.res();
2003 let is_import = name_binding.is_import();
2004 let span = name_binding.span;
2005 if let Res::Def(DefKind::Fn, _) = res {
2006 self.record_use(ident, name_binding, false);
2008 self.main_def = Some(MainDefinition { res, is_import, span });
2012 fn names_to_string(names: &[Symbol]) -> String {
2013 let mut result = String::new();
2014 for (i, name) in names.iter().filter(|name| **name != kw::PathRoot).enumerate() {
2016 result.push_str("::");
2018 if Ident::with_dummy_span(*name).is_raw_guess() {
2019 result.push_str("r#");
2021 result.push_str(name.as_str());
2026 fn path_names_to_string(path: &Path) -> String {
2027 names_to_string(&path.segments.iter().map(|seg| seg.ident.name).collect::<Vec<_>>())
2030 /// A somewhat inefficient routine to obtain the name of a module.
2031 fn module_to_string(module: Module<'_>) -> Option<String> {
2032 let mut names = Vec::new();
2034 fn collect_mod(names: &mut Vec<Symbol>, module: Module<'_>) {
2035 if let ModuleKind::Def(.., name) = module.kind {
2036 if let Some(parent) = module.parent {
2038 collect_mod(names, parent);
2041 names.push(Symbol::intern("<opaque>"));
2042 collect_mod(names, module.parent.unwrap());
2045 collect_mod(&mut names, module);
2047 if names.is_empty() {
2051 Some(names_to_string(&names))
2054 #[derive(Copy, Clone, Debug)]
2056 /// Node ID for linting.
2058 /// Span of the whole path or some its characteristic fragment.
2059 /// E.g. span of `b` in `foo::{a, b, c}`, or full span for regular paths.
2061 /// Span of the path start, suitable for prepending something to to it.
2062 /// E.g. span of `foo` in `foo::{a, b, c}`, or full span for regular paths.
2064 /// Whether to report privacy errors or silently return "no resolution" for them,
2065 /// similarly to speculative resolution.
2066 report_private: bool,
2070 fn new(node_id: NodeId, path_span: Span) -> Finalize {
2071 Finalize::with_root_span(node_id, path_span, path_span)
2074 fn with_root_span(node_id: NodeId, path_span: Span, root_span: Span) -> Finalize {
2075 Finalize { node_id, path_span, root_span, report_private: true }
2079 pub fn provide(providers: &mut Providers) {
2080 late::lifetimes::provide(providers);