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 #![feature(iter_intersperse)]
14 #![feature(let_chains)]
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};
62 use diagnostics::{ImportSuggestion, LabelSuggestion, Suggestion};
63 use imports::{Import, ImportKind, ImportResolver, NameResolution};
64 use late::{HasGenericParams, PathSource, PatternSource};
65 use macros::{MacroRulesBinding, MacroRulesScope, MacroRulesScopeRef};
67 use crate::access_levels::AccessLevelsVisitor;
69 type Res = def::Res<NodeId>;
72 mod build_reduced_graph;
86 #[derive(Copy, Clone, PartialEq, Debug)]
87 pub enum Determinacy {
93 fn determined(determined: bool) -> Determinacy {
94 if determined { Determinacy::Determined } else { Determinacy::Undetermined }
98 /// A specific scope in which a name can be looked up.
99 /// This enum is currently used only for early resolution (imports and macros),
100 /// but not for late resolution yet.
101 #[derive(Clone, Copy)]
103 DeriveHelpers(LocalExpnId),
105 MacroRules(MacroRulesScopeRef<'a>),
107 // The node ID is for reporting the `PROC_MACRO_DERIVE_RESOLUTION_FALLBACK`
108 // lint if it should be reported.
109 Module(Module<'a>, Option<NodeId>),
118 /// Names from different contexts may want to visit different subsets of all specific scopes
119 /// with different restrictions when looking up the resolution.
120 /// This enum is currently used only for early resolution (imports and macros),
121 /// but not for late resolution yet.
122 #[derive(Clone, Copy)]
124 /// All scopes with the given namespace.
125 All(Namespace, /*is_import*/ bool),
126 /// Crate root, then extern prelude (used for mixed 2015-2018 mode in macros).
127 AbsolutePath(Namespace),
128 /// All scopes with macro namespace and the given macro kind restriction.
130 /// All scopes with the given namespace, used for partially performing late resolution.
131 /// The node id enables lints and is used for reporting them.
132 Late(Namespace, Module<'a>, Option<NodeId>),
135 /// Everything you need to know about a name's location to resolve it.
136 /// Serves as a starting point for the scope visitor.
137 /// This struct is currently used only for early resolution (imports and macros),
138 /// but not for late resolution yet.
139 #[derive(Clone, Copy, Debug)]
140 pub struct ParentScope<'a> {
141 pub module: Module<'a>,
142 expansion: LocalExpnId,
143 pub macro_rules: MacroRulesScopeRef<'a>,
144 derives: &'a [ast::Path],
147 impl<'a> ParentScope<'a> {
148 /// Creates a parent scope with the passed argument used as the module scope component,
149 /// and other scope components set to default empty values.
150 pub fn module(module: Module<'a>, resolver: &Resolver<'a>) -> ParentScope<'a> {
153 expansion: LocalExpnId::ROOT,
154 macro_rules: resolver.arenas.alloc_macro_rules_scope(MacroRulesScope::Empty),
160 #[derive(Copy, Debug, Clone)]
161 enum ImplTraitContext {
163 Universal(LocalDefId),
167 struct BindingError {
169 origin: BTreeSet<Span>,
170 target: BTreeSet<Span>,
174 impl PartialOrd for BindingError {
175 fn partial_cmp(&self, other: &BindingError) -> Option<cmp::Ordering> {
176 Some(self.cmp(other))
180 impl PartialEq for BindingError {
181 fn eq(&self, other: &BindingError) -> bool {
182 self.name == other.name
186 impl Ord for BindingError {
187 fn cmp(&self, other: &BindingError) -> cmp::Ordering {
188 self.name.cmp(&other.name)
192 enum ResolutionError<'a> {
193 /// Error E0401: can't use type or const parameters from outer function.
194 GenericParamsFromOuterFunction(Res, HasGenericParams),
195 /// Error E0403: the name is already used for a type or const parameter in this generic
197 NameAlreadyUsedInParameterList(Symbol, Span),
198 /// Error E0407: method is not a member of trait.
199 MethodNotMemberOfTrait(Ident, String, Option<Symbol>),
200 /// Error E0437: type is not a member of trait.
201 TypeNotMemberOfTrait(Ident, String, Option<Symbol>),
202 /// Error E0438: const is not a member of trait.
203 ConstNotMemberOfTrait(Ident, String, Option<Symbol>),
204 /// Error E0408: variable `{}` is not bound in all patterns.
205 VariableNotBoundInPattern(BindingError, ParentScope<'a>),
206 /// Error E0409: variable `{}` is bound in inconsistent ways within the same match arm.
207 VariableBoundWithDifferentMode(Symbol, Span),
208 /// Error E0415: identifier is bound more than once in this parameter list.
209 IdentifierBoundMoreThanOnceInParameterList(Symbol),
210 /// Error E0416: identifier is bound more than once in the same pattern.
211 IdentifierBoundMoreThanOnceInSamePattern(Symbol),
212 /// Error E0426: use of undeclared label.
213 UndeclaredLabel { name: Symbol, suggestion: Option<LabelSuggestion> },
214 /// Error E0429: `self` imports are only allowed within a `{ }` list.
215 SelfImportsOnlyAllowedWithin { root: bool, span_with_rename: Span },
216 /// Error E0430: `self` import can only appear once in the list.
217 SelfImportCanOnlyAppearOnceInTheList,
218 /// Error E0431: `self` import can only appear in an import list with a non-empty prefix.
219 SelfImportOnlyInImportListWithNonEmptyPrefix,
220 /// Error E0433: failed to resolve.
221 FailedToResolve { label: String, suggestion: Option<Suggestion> },
222 /// Error E0434: can't capture dynamic environment in a fn item.
223 CannotCaptureDynamicEnvironmentInFnItem,
224 /// Error E0435: attempt to use a non-constant value in a constant.
225 AttemptToUseNonConstantValueInConstant(
227 /* suggestion */ &'static str,
228 /* current */ &'static str,
230 /// Error E0530: `X` bindings cannot shadow `Y`s.
231 BindingShadowsSomethingUnacceptable {
232 shadowing_binding: PatternSource,
234 participle: &'static str,
235 article: &'static str,
236 shadowed_binding: Res,
237 shadowed_binding_span: Span,
239 /// Error E0128: generic parameters with a default cannot use forward-declared identifiers.
240 ForwardDeclaredGenericParam,
241 /// ERROR E0770: the type of const parameters must not depend on other generic parameters.
242 ParamInTyOfConstParam(Symbol),
243 /// generic parameters must not be used inside const evaluations.
245 /// This error is only emitted when using `min_const_generics`.
246 ParamInNonTrivialAnonConst { name: Symbol, is_type: bool },
247 /// Error E0735: generic parameters with a default cannot use `Self`
248 SelfInGenericParamDefault,
249 /// Error E0767: use of unreachable label
250 UnreachableLabel { name: Symbol, definition_span: Span, suggestion: Option<LabelSuggestion> },
251 /// Error E0323, E0324, E0325: mismatch between trait item and impl item.
256 trait_item_span: Span,
257 code: rustc_errors::DiagnosticId,
259 /// Inline asm `sym` operand must refer to a `fn` or `static`.
263 enum VisResolutionError<'a> {
264 Relative2018(Span, &'a ast::Path),
266 FailedToResolve(Span, String, Option<Suggestion>),
267 ExpectedFound(Span, String, Res),
272 /// A minimal representation of a path segment. We use this in resolve because we synthesize 'path
273 /// segments' which don't have the rest of an AST or HIR `PathSegment`.
274 #[derive(Clone, Copy, Debug)]
278 /// Signals whether this `PathSegment` has generic arguments. Used to avoid providing
279 /// nonsensical suggestions.
280 has_generic_args: bool,
281 /// Signals whether this `PathSegment` has lifetime arguments.
282 has_lifetime_args: bool,
287 fn from_path(path: &Path) -> Vec<Segment> {
288 path.segments.iter().map(|s| s.into()).collect()
291 fn from_ident(ident: Ident) -> Segment {
295 has_generic_args: false,
296 has_lifetime_args: false,
301 fn from_ident_and_id(ident: Ident, id: NodeId) -> Segment {
305 has_generic_args: false,
306 has_lifetime_args: false,
311 fn names_to_string(segments: &[Segment]) -> String {
312 names_to_string(&segments.iter().map(|seg| seg.ident.name).collect::<Vec<_>>())
316 impl<'a> From<&'a ast::PathSegment> for Segment {
317 fn from(seg: &'a ast::PathSegment) -> Segment {
318 let has_generic_args = seg.args.is_some();
319 let (args_span, has_lifetime_args) = if let Some(args) = seg.args.as_deref() {
321 GenericArgs::AngleBracketed(args) => {
322 let found_lifetimes = args
325 .any(|arg| matches!(arg, AngleBracketedArg::Arg(GenericArg::Lifetime(_))));
326 (args.span, found_lifetimes)
328 GenericArgs::Parenthesized(args) => (args.span, true),
343 /// An intermediate resolution result.
345 /// This refers to the thing referred by a name. The difference between `Res` and `Item` is that
346 /// items are visible in their whole block, while `Res`es only from the place they are defined
349 enum LexicalScopeBinding<'a> {
350 Item(&'a NameBinding<'a>),
354 impl<'a> LexicalScopeBinding<'a> {
355 fn res(self) -> Res {
357 LexicalScopeBinding::Item(binding) => binding.res(),
358 LexicalScopeBinding::Res(res) => res,
363 #[derive(Copy, Clone, Debug)]
364 enum ModuleOrUniformRoot<'a> {
368 /// Virtual module that denotes resolution in crate root with fallback to extern prelude.
369 CrateRootAndExternPrelude,
371 /// Virtual module that denotes resolution in extern prelude.
372 /// Used for paths starting with `::` on 2018 edition.
375 /// Virtual module that denotes resolution in current scope.
376 /// Used only for resolving single-segment imports. The reason it exists is that import paths
377 /// are always split into two parts, the first of which should be some kind of module.
381 impl ModuleOrUniformRoot<'_> {
382 fn same_def(lhs: Self, rhs: Self) -> bool {
384 (ModuleOrUniformRoot::Module(lhs), ModuleOrUniformRoot::Module(rhs)) => {
388 ModuleOrUniformRoot::CrateRootAndExternPrelude,
389 ModuleOrUniformRoot::CrateRootAndExternPrelude,
391 | (ModuleOrUniformRoot::ExternPrelude, ModuleOrUniformRoot::ExternPrelude)
392 | (ModuleOrUniformRoot::CurrentScope, ModuleOrUniformRoot::CurrentScope) => true,
398 #[derive(Clone, Debug)]
399 enum PathResult<'a> {
400 Module(ModuleOrUniformRoot<'a>),
401 NonModule(PartialRes),
406 suggestion: Option<Suggestion>,
407 is_error_from_last_segment: bool,
411 impl<'a> PathResult<'a> {
414 is_error_from_last_segment: bool,
416 label_and_suggestion: impl FnOnce() -> (String, Option<Suggestion>),
417 ) -> PathResult<'a> {
418 let (label, suggestion) =
419 if finalize { label_and_suggestion() } else { (String::new(), None) };
420 PathResult::Failed { span, label, suggestion, is_error_from_last_segment }
426 /// An anonymous module; e.g., just a block.
431 /// { // This is an anonymous module
432 /// f(); // This resolves to (2) as we are inside the block.
435 /// f(); // Resolves to (1)
439 /// Any module with a name.
443 /// * A normal module – either `mod from_file;` or `mod from_block { }` –
444 /// or the crate root (which is conceptually a top-level module).
445 /// Note that the crate root's [name][Self::name] will be [`kw::Empty`].
446 /// * A trait or an enum (it implicitly contains associated types, methods and variant
448 Def(DefKind, DefId, Symbol),
452 /// Get name of the module.
453 pub fn name(&self) -> Option<Symbol> {
455 ModuleKind::Block => None,
456 ModuleKind::Def(.., name) => Some(*name),
461 /// A key that identifies a binding in a given `Module`.
463 /// Multiple bindings in the same module can have the same key (in a valid
464 /// program) if all but one of them come from glob imports.
465 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
467 /// The identifier for the binding, always the `normalize_to_macros_2_0` version of the
471 /// 0 if ident is not `_`, otherwise a value that's unique to the specific
472 /// `_` in the expanded AST that introduced this binding.
476 type Resolutions<'a> = RefCell<FxIndexMap<BindingKey, &'a RefCell<NameResolution<'a>>>>;
478 /// One node in the tree of modules.
480 /// Note that a "module" in resolve is broader than a `mod` that you declare in Rust code. It may be one of these:
483 /// * crate root (aka, top-level anonymous module)
486 /// * curly-braced block with statements
488 /// You can use [`ModuleData::kind`] to determine the kind of module this is.
489 pub struct ModuleData<'a> {
490 /// The direct parent module (it may not be a `mod`, however).
491 parent: Option<Module<'a>>,
492 /// What kind of module this is, because this may not be a `mod`.
495 /// Mapping between names and their (possibly in-progress) resolutions in this module.
496 /// Resolutions in modules from other crates are not populated until accessed.
497 lazy_resolutions: Resolutions<'a>,
498 /// True if this is a module from other crate that needs to be populated on access.
499 populate_on_access: Cell<bool>,
501 /// Macro invocations that can expand into items in this module.
502 unexpanded_invocations: RefCell<FxHashSet<LocalExpnId>>,
504 /// Whether `#[no_implicit_prelude]` is active.
505 no_implicit_prelude: bool,
507 glob_importers: RefCell<Vec<&'a Import<'a>>>,
508 globs: RefCell<Vec<&'a Import<'a>>>,
510 /// Used to memoize the traits in this module for faster searches through all traits in scope.
511 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
513 /// Span of the module itself. Used for error reporting.
519 type Module<'a> = &'a ModuleData<'a>;
521 impl<'a> ModuleData<'a> {
523 parent: Option<Module<'a>>,
527 no_implicit_prelude: bool,
529 let is_foreign = match kind {
530 ModuleKind::Def(_, def_id, _) => !def_id.is_local(),
531 ModuleKind::Block => false,
536 lazy_resolutions: Default::default(),
537 populate_on_access: Cell::new(is_foreign),
538 unexpanded_invocations: Default::default(),
540 glob_importers: RefCell::new(Vec::new()),
541 globs: RefCell::new(Vec::new()),
542 traits: RefCell::new(None),
548 fn for_each_child<R, F>(&'a self, resolver: &mut R, mut f: F)
550 R: AsMut<Resolver<'a>>,
551 F: FnMut(&mut R, Ident, Namespace, &'a NameBinding<'a>),
553 for (key, name_resolution) in resolver.as_mut().resolutions(self).borrow().iter() {
554 if let Some(binding) = name_resolution.borrow().binding {
555 f(resolver, key.ident, key.ns, binding);
560 /// This modifies `self` in place. The traits will be stored in `self.traits`.
561 fn ensure_traits<R>(&'a self, resolver: &mut R)
563 R: AsMut<Resolver<'a>>,
565 let mut traits = self.traits.borrow_mut();
566 if traits.is_none() {
567 let mut collected_traits = Vec::new();
568 self.for_each_child(resolver, |_, name, ns, binding| {
572 if let Res::Def(DefKind::Trait | DefKind::TraitAlias, _) = binding.res() {
573 collected_traits.push((name, binding))
576 *traits = Some(collected_traits.into_boxed_slice());
580 fn res(&self) -> Option<Res> {
582 ModuleKind::Def(kind, def_id, _) => Some(Res::Def(kind, def_id)),
587 // Public for rustdoc.
588 pub fn def_id(&self) -> DefId {
589 self.opt_def_id().expect("`ModuleData::def_id` is called on a block module")
592 fn opt_def_id(&self) -> Option<DefId> {
594 ModuleKind::Def(_, def_id, _) => Some(def_id),
599 // `self` resolves to the first module ancestor that `is_normal`.
600 fn is_normal(&self) -> bool {
601 matches!(self.kind, ModuleKind::Def(DefKind::Mod, _, _))
604 fn is_trait(&self) -> bool {
605 matches!(self.kind, ModuleKind::Def(DefKind::Trait, _, _))
608 fn nearest_item_scope(&'a self) -> Module<'a> {
610 ModuleKind::Def(DefKind::Enum | DefKind::Trait, ..) => {
611 self.parent.expect("enum or trait module without a parent")
617 /// The [`DefId`] of the nearest `mod` item ancestor (which may be this module).
618 /// This may be the crate root.
619 fn nearest_parent_mod(&self) -> DefId {
621 ModuleKind::Def(DefKind::Mod, def_id, _) => def_id,
622 _ => self.parent.expect("non-root module without parent").nearest_parent_mod(),
626 fn is_ancestor_of(&self, mut other: &Self) -> bool {
627 while !ptr::eq(self, other) {
628 if let Some(parent) = other.parent {
638 impl<'a> fmt::Debug for ModuleData<'a> {
639 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
640 write!(f, "{:?}", self.res())
644 /// Records a possibly-private value, type, or module definition.
645 #[derive(Clone, Debug)]
646 pub struct NameBinding<'a> {
647 kind: NameBindingKind<'a>,
648 ambiguity: Option<(&'a NameBinding<'a>, AmbiguityKind)>,
649 expansion: LocalExpnId,
654 pub trait ToNameBinding<'a> {
655 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
658 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
659 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
664 #[derive(Clone, Debug)]
665 enum NameBindingKind<'a> {
666 Res(Res, /* is_macro_export */ bool),
668 Import { binding: &'a NameBinding<'a>, import: &'a Import<'a>, used: Cell<bool> },
671 impl<'a> NameBindingKind<'a> {
672 /// Is this a name binding of an import?
673 fn is_import(&self) -> bool {
674 matches!(*self, NameBindingKind::Import { .. })
678 struct PrivacyError<'a> {
680 binding: &'a NameBinding<'a>,
684 struct UseError<'a> {
685 err: DiagnosticBuilder<'a, ErrorGuaranteed>,
686 /// Candidates which user could `use` to access the missing type.
687 candidates: Vec<ImportSuggestion>,
688 /// The `DefId` of the module to place the use-statements in.
690 /// Whether the diagnostic should say "instead" (as in `consider importing ... instead`).
692 /// Extra free-form suggestion.
693 suggestion: Option<(Span, &'static str, String, Applicability)>,
694 /// Path `Segment`s at the place of use that failed. Used for accurate suggestion after telling
695 /// the user to import the item directly.
699 #[derive(Clone, Copy, PartialEq, Debug)]
704 MacroRulesVsModularized,
712 fn descr(self) -> &'static str {
714 AmbiguityKind::Import => "multiple potential import sources",
715 AmbiguityKind::BuiltinAttr => "a name conflict with a builtin attribute",
716 AmbiguityKind::DeriveHelper => "a name conflict with a derive helper attribute",
717 AmbiguityKind::MacroRulesVsModularized => {
718 "a conflict between a `macro_rules` name and a non-`macro_rules` name from another module"
720 AmbiguityKind::GlobVsOuter => {
721 "a conflict between a name from a glob import and an outer scope during import or macro resolution"
723 AmbiguityKind::GlobVsGlob => "multiple glob imports of a name in the same module",
724 AmbiguityKind::GlobVsExpanded => {
725 "a conflict between a name from a glob import and a macro-expanded name in the same module during import or macro resolution"
727 AmbiguityKind::MoreExpandedVsOuter => {
728 "a conflict between a macro-expanded name and a less macro-expanded name from outer scope during import or macro resolution"
734 /// Miscellaneous bits of metadata for better ambiguity error reporting.
735 #[derive(Clone, Copy, PartialEq)]
736 enum AmbiguityErrorMisc {
743 struct AmbiguityError<'a> {
746 b1: &'a NameBinding<'a>,
747 b2: &'a NameBinding<'a>,
748 misc1: AmbiguityErrorMisc,
749 misc2: AmbiguityErrorMisc,
752 impl<'a> NameBinding<'a> {
753 fn module(&self) -> Option<Module<'a>> {
755 NameBindingKind::Module(module) => Some(module),
756 NameBindingKind::Import { binding, .. } => binding.module(),
761 fn res(&self) -> Res {
763 NameBindingKind::Res(res, _) => res,
764 NameBindingKind::Module(module) => module.res().unwrap(),
765 NameBindingKind::Import { binding, .. } => binding.res(),
769 fn is_ambiguity(&self) -> bool {
770 self.ambiguity.is_some()
772 NameBindingKind::Import { binding, .. } => binding.is_ambiguity(),
777 fn is_possibly_imported_variant(&self) -> bool {
779 NameBindingKind::Import { binding, .. } => binding.is_possibly_imported_variant(),
780 NameBindingKind::Res(
781 Res::Def(DefKind::Variant | DefKind::Ctor(CtorOf::Variant, ..), _),
784 NameBindingKind::Res(..) | NameBindingKind::Module(..) => false,
788 fn is_extern_crate(&self) -> bool {
790 NameBindingKind::Import {
791 import: &Import { kind: ImportKind::ExternCrate { .. }, .. },
794 NameBindingKind::Module(&ModuleData {
795 kind: ModuleKind::Def(DefKind::Mod, def_id, _),
797 }) => def_id.is_crate_root(),
802 fn is_import(&self) -> bool {
803 matches!(self.kind, NameBindingKind::Import { .. })
806 fn is_glob_import(&self) -> bool {
808 NameBindingKind::Import { import, .. } => import.is_glob(),
813 fn is_importable(&self) -> bool {
816 Res::Def(DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy, _)
820 fn macro_kind(&self) -> Option<MacroKind> {
821 self.res().macro_kind()
824 // Suppose that we resolved macro invocation with `invoc_parent_expansion` to binding `binding`
825 // at some expansion round `max(invoc, binding)` when they both emerged from macros.
826 // Then this function returns `true` if `self` may emerge from a macro *after* that
827 // in some later round and screw up our previously found resolution.
828 // See more detailed explanation in
829 // https://github.com/rust-lang/rust/pull/53778#issuecomment-419224049
832 invoc_parent_expansion: LocalExpnId,
833 binding: &NameBinding<'_>,
835 // self > max(invoc, binding) => !(self <= invoc || self <= binding)
836 // Expansions are partially ordered, so "may appear after" is an inversion of
837 // "certainly appears before or simultaneously" and includes unordered cases.
838 let self_parent_expansion = self.expansion;
839 let other_parent_expansion = binding.expansion;
840 let certainly_before_other_or_simultaneously =
841 other_parent_expansion.is_descendant_of(self_parent_expansion);
842 let certainly_before_invoc_or_simultaneously =
843 invoc_parent_expansion.is_descendant_of(self_parent_expansion);
844 !(certainly_before_other_or_simultaneously || certainly_before_invoc_or_simultaneously)
848 #[derive(Debug, Default, Clone)]
849 pub struct ExternPreludeEntry<'a> {
850 extern_crate_item: Option<&'a NameBinding<'a>>,
851 pub introduced_by_item: bool,
854 /// Used for better errors for E0773
855 enum BuiltinMacroState {
856 NotYetSeen(SyntaxExtensionKind),
861 resolutions: DeriveResolutions,
862 helper_attrs: Vec<(usize, Ident)>,
863 has_derive_copy: bool,
868 ext: Lrc<SyntaxExtension>,
872 /// The main resolver class.
874 /// This is the visitor that walks the whole crate.
875 pub struct Resolver<'a> {
876 session: &'a Session,
878 definitions: Definitions,
879 /// Item with a given `LocalDefId` was defined during macro expansion with ID `ExpnId`.
880 expn_that_defined: FxHashMap<LocalDefId, ExpnId>,
881 /// Reference span for definitions.
882 source_span: IndexVec<LocalDefId, Span>,
884 graph_root: Module<'a>,
886 prelude: Option<Module<'a>>,
887 extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'a>>,
889 /// N.B., this is used only for better diagnostics, not name resolution itself.
890 has_self: FxHashSet<DefId>,
892 /// Names of fields of an item `DefId` accessible with dot syntax.
893 /// Used for hints during error reporting.
894 field_names: FxHashMap<DefId, Vec<Spanned<Symbol>>>,
896 /// All imports known to succeed or fail.
897 determined_imports: Vec<&'a Import<'a>>,
899 /// All non-determined imports.
900 indeterminate_imports: Vec<&'a Import<'a>>,
902 // Spans for local variables found during pattern resolution.
903 // Used for suggestions during error reporting.
904 pat_span_map: NodeMap<Span>,
906 /// Resolutions for nodes that have a single resolution.
907 partial_res_map: NodeMap<PartialRes>,
908 /// Resolutions for import nodes, which have multiple resolutions in different namespaces.
909 import_res_map: NodeMap<PerNS<Option<Res>>>,
910 /// Resolutions for labels (node IDs of their corresponding blocks or loops).
911 label_res_map: NodeMap<NodeId>,
912 /// Resolutions for lifetimes.
913 lifetimes_res_map: NodeMap<LifetimeRes>,
914 /// Mapping from generics `def_id`s to TAIT generics `def_id`s.
915 /// For each captured lifetime (e.g., 'a), we create a new lifetime parameter that is a generic
916 /// defined on the TAIT, so we have type Foo<'a1> = ... and we establish a mapping in this
917 /// field from the original parameter 'a to the new parameter 'a1.
918 generics_def_id_map: Vec<FxHashMap<LocalDefId, LocalDefId>>,
919 /// Lifetime parameters that lowering will have to introduce.
920 extra_lifetime_params_map: NodeMap<Vec<(Ident, NodeId, LifetimeRes)>>,
922 /// `CrateNum` resolutions of `extern crate` items.
923 extern_crate_map: FxHashMap<LocalDefId, CrateNum>,
924 reexport_map: FxHashMap<LocalDefId, Vec<ModChild>>,
925 trait_map: NodeMap<Vec<TraitCandidate>>,
927 /// A map from nodes to anonymous modules.
928 /// Anonymous modules are pseudo-modules that are implicitly created around items
929 /// contained within blocks.
931 /// For example, if we have this:
939 /// There will be an anonymous module created around `g` with the ID of the
940 /// entry block for `f`.
941 block_map: NodeMap<Module<'a>>,
942 /// A fake module that contains no definition and no prelude. Used so that
943 /// some AST passes can generate identifiers that only resolve to local or
945 empty_module: Module<'a>,
946 module_map: FxHashMap<DefId, Module<'a>>,
947 binding_parent_modules: FxHashMap<Interned<'a, NameBinding<'a>>, Module<'a>>,
948 underscore_disambiguator: u32,
950 /// Maps glob imports to the names of items actually imported.
951 glob_map: FxHashMap<LocalDefId, FxHashSet<Symbol>>,
952 /// Visibilities in "lowered" form, for all entities that have them.
953 visibilities: FxHashMap<LocalDefId, ty::Visibility>,
954 has_pub_restricted: bool,
955 used_imports: FxHashSet<NodeId>,
956 maybe_unused_trait_imports: FxIndexSet<LocalDefId>,
957 maybe_unused_extern_crates: Vec<(LocalDefId, Span)>,
959 /// Privacy errors are delayed until the end in order to deduplicate them.
960 privacy_errors: Vec<PrivacyError<'a>>,
961 /// Ambiguity errors are delayed for deduplication.
962 ambiguity_errors: Vec<AmbiguityError<'a>>,
963 /// `use` injections are delayed for better placement and deduplication.
964 use_injections: Vec<UseError<'a>>,
965 /// Crate-local macro expanded `macro_export` referred to by a module-relative path.
966 macro_expanded_macro_export_errors: BTreeSet<(Span, Span)>,
968 arenas: &'a ResolverArenas<'a>,
969 dummy_binding: &'a NameBinding<'a>,
971 crate_loader: CrateLoader<'a>,
972 macro_names: FxHashSet<Ident>,
973 builtin_macros: FxHashMap<Symbol, BuiltinMacroState>,
974 /// A small map keeping true kinds of built-in macros that appear to be fn-like on
975 /// the surface (`macro` items in libcore), but are actually attributes or derives.
976 builtin_macro_kinds: FxHashMap<LocalDefId, MacroKind>,
977 registered_tools: RegisteredTools,
978 macro_use_prelude: FxHashMap<Symbol, &'a NameBinding<'a>>,
979 macro_map: FxHashMap<DefId, MacroData>,
980 dummy_ext_bang: Lrc<SyntaxExtension>,
981 dummy_ext_derive: Lrc<SyntaxExtension>,
982 non_macro_attr: Lrc<SyntaxExtension>,
983 local_macro_def_scopes: FxHashMap<LocalDefId, Module<'a>>,
984 ast_transform_scopes: FxHashMap<LocalExpnId, Module<'a>>,
985 unused_macros: FxHashMap<LocalDefId, (NodeId, Ident)>,
986 unused_macro_rules: FxHashMap<(LocalDefId, usize), (Ident, Span)>,
987 proc_macro_stubs: FxHashSet<LocalDefId>,
988 /// Traces collected during macro resolution and validated when it's complete.
989 single_segment_macro_resolutions:
990 Vec<(Ident, MacroKind, ParentScope<'a>, Option<&'a NameBinding<'a>>)>,
991 multi_segment_macro_resolutions:
992 Vec<(Vec<Segment>, Span, MacroKind, ParentScope<'a>, Option<Res>)>,
993 builtin_attrs: Vec<(Ident, ParentScope<'a>)>,
994 /// `derive(Copy)` marks items they are applied to so they are treated specially later.
995 /// Derive macros cannot modify the item themselves and have to store the markers in the global
996 /// context, so they attach the markers to derive container IDs using this resolver table.
997 containers_deriving_copy: FxHashSet<LocalExpnId>,
998 /// Parent scopes in which the macros were invoked.
999 /// FIXME: `derives` are missing in these parent scopes and need to be taken from elsewhere.
1000 invocation_parent_scopes: FxHashMap<LocalExpnId, ParentScope<'a>>,
1001 /// `macro_rules` scopes *produced* by expanding the macro invocations,
1002 /// include all the `macro_rules` items and other invocations generated by them.
1003 output_macro_rules_scopes: FxHashMap<LocalExpnId, MacroRulesScopeRef<'a>>,
1004 /// `macro_rules` scopes produced by `macro_rules` item definitions.
1005 macro_rules_scopes: FxHashMap<LocalDefId, MacroRulesScopeRef<'a>>,
1006 /// Helper attributes that are in scope for the given expansion.
1007 helper_attrs: FxHashMap<LocalExpnId, Vec<Ident>>,
1008 /// Ready or in-progress results of resolving paths inside the `#[derive(...)]` attribute
1009 /// with the given `ExpnId`.
1010 derive_data: FxHashMap<LocalExpnId, DeriveData>,
1012 /// Avoid duplicated errors for "name already defined".
1013 name_already_seen: FxHashMap<Symbol, Span>,
1015 potentially_unused_imports: Vec<&'a Import<'a>>,
1017 /// Table for mapping struct IDs into struct constructor IDs,
1018 /// it's not used during normal resolution, only for better error reporting.
1019 /// Also includes of list of each fields visibility
1020 struct_constructors: DefIdMap<(Res, ty::Visibility, Vec<ty::Visibility>)>,
1022 /// Features enabled for this crate.
1023 active_features: FxHashSet<Symbol>,
1025 lint_buffer: LintBuffer,
1027 next_node_id: NodeId,
1029 node_id_to_def_id: FxHashMap<ast::NodeId, LocalDefId>,
1030 def_id_to_node_id: IndexVec<LocalDefId, ast::NodeId>,
1032 /// Indices of unnamed struct or variant fields with unresolved attributes.
1033 placeholder_field_indices: FxHashMap<NodeId, usize>,
1034 /// When collecting definitions from an AST fragment produced by a macro invocation `ExpnId`
1035 /// we know what parent node that fragment should be attached to thanks to this table,
1036 /// and how the `impl Trait` fragments were introduced.
1037 invocation_parents: FxHashMap<LocalExpnId, (LocalDefId, ImplTraitContext)>,
1039 /// Some way to know that we are in a *trait* impl in `visit_assoc_item`.
1040 /// FIXME: Replace with a more general AST map (together with some other fields).
1041 trait_impl_items: FxHashSet<LocalDefId>,
1043 legacy_const_generic_args: FxHashMap<DefId, Option<Vec<usize>>>,
1044 /// Amount of lifetime parameters for each item in the crate.
1045 item_generics_num_lifetimes: FxHashMap<LocalDefId, usize>,
1047 main_def: Option<MainDefinition>,
1048 trait_impls: FxIndexMap<DefId, Vec<LocalDefId>>,
1049 /// A list of proc macro LocalDefIds, written out in the order in which
1050 /// they are declared in the static array generated by proc_macro_harness.
1051 proc_macros: Vec<NodeId>,
1052 confused_type_with_std_module: FxHashMap<Span, Span>,
1054 access_levels: AccessLevels,
1057 /// Nothing really interesting here; it just provides memory for the rest of the crate.
1059 pub struct ResolverArenas<'a> {
1060 modules: TypedArena<ModuleData<'a>>,
1061 local_modules: RefCell<Vec<Module<'a>>>,
1062 imports: TypedArena<Import<'a>>,
1063 name_resolutions: TypedArena<RefCell<NameResolution<'a>>>,
1064 ast_paths: TypedArena<ast::Path>,
1065 dropless: DroplessArena,
1068 impl<'a> ResolverArenas<'a> {
1071 parent: Option<Module<'a>>,
1075 no_implicit_prelude: bool,
1076 module_map: &mut FxHashMap<DefId, Module<'a>>,
1079 self.modules.alloc(ModuleData::new(parent, kind, expn_id, span, no_implicit_prelude));
1080 let def_id = module.opt_def_id();
1081 if def_id.map_or(true, |def_id| def_id.is_local()) {
1082 self.local_modules.borrow_mut().push(module);
1084 if let Some(def_id) = def_id {
1085 module_map.insert(def_id, module);
1089 fn local_modules(&'a self) -> std::cell::Ref<'a, Vec<Module<'a>>> {
1090 self.local_modules.borrow()
1092 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1093 self.dropless.alloc(name_binding)
1095 fn alloc_import(&'a self, import: Import<'a>) -> &'a Import<'_> {
1096 self.imports.alloc(import)
1098 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1099 self.name_resolutions.alloc(Default::default())
1101 fn alloc_macro_rules_scope(&'a self, scope: MacroRulesScope<'a>) -> MacroRulesScopeRef<'a> {
1102 Interned::new_unchecked(self.dropless.alloc(Cell::new(scope)))
1104 fn alloc_macro_rules_binding(
1106 binding: MacroRulesBinding<'a>,
1107 ) -> &'a MacroRulesBinding<'a> {
1108 self.dropless.alloc(binding)
1110 fn alloc_ast_paths(&'a self, paths: &[ast::Path]) -> &'a [ast::Path] {
1111 self.ast_paths.alloc_from_iter(paths.iter().cloned())
1113 fn alloc_pattern_spans(&'a self, spans: impl Iterator<Item = Span>) -> &'a [Span] {
1114 self.dropless.alloc_from_iter(spans)
1118 impl<'a> AsMut<Resolver<'a>> for Resolver<'a> {
1119 fn as_mut(&mut self) -> &mut Resolver<'a> {
1124 impl<'a, 'b> DefIdTree for &'a Resolver<'b> {
1126 fn opt_parent(self, id: DefId) -> Option<DefId> {
1127 match id.as_local() {
1128 Some(id) => self.definitions.def_key(id).parent,
1129 None => self.cstore().def_key(id).parent,
1131 .map(|index| DefId { index, ..id })
1136 fn opt_local_def_id(&self, node: NodeId) -> Option<LocalDefId> {
1137 self.node_id_to_def_id.get(&node).copied()
1140 pub fn local_def_id(&self, node: NodeId) -> LocalDefId {
1141 self.opt_local_def_id(node).unwrap_or_else(|| panic!("no entry for node id: `{:?}`", node))
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);
1163 // Create the definition.
1164 if expn_id != ExpnId::root() {
1165 self.expn_that_defined.insert(def_id, expn_id);
1168 // A relative span's parent must be an absolute span.
1169 debug_assert_eq!(span.data_untracked().parent, None);
1170 let _id = self.source_span.push(span);
1171 debug_assert_eq!(_id, def_id);
1173 // Some things for which we allocate `LocalDefId`s don't correspond to
1174 // anything in the AST, so they don't have a `NodeId`. For these cases
1175 // we don't need a mapping from `NodeId` to `LocalDefId`.
1176 if node_id != ast::DUMMY_NODE_ID {
1177 debug!("create_def: def_id_to_node_id[{:?}] <-> {:?}", def_id, node_id);
1178 self.node_id_to_def_id.insert(node_id, def_id);
1180 assert_eq!(self.def_id_to_node_id.push(node_id), def_id);
1185 fn item_generics_num_lifetimes(&self, def_id: DefId) -> usize {
1186 if let Some(def_id) = def_id.as_local() {
1187 self.item_generics_num_lifetimes[&def_id]
1189 self.cstore().item_generics_num_lifetimes(def_id, self.session)
1194 impl<'a> Resolver<'a> {
1196 session: &'a Session,
1199 metadata_loader: Box<MetadataLoaderDyn>,
1200 arenas: &'a ResolverArenas<'a>,
1202 let root_def_id = CRATE_DEF_ID.to_def_id();
1203 let mut module_map = FxHashMap::default();
1204 let graph_root = arenas.new_module(
1206 ModuleKind::Def(DefKind::Mod, root_def_id, kw::Empty),
1208 krate.spans.inner_span,
1209 session.contains_name(&krate.attrs, sym::no_implicit_prelude),
1212 let empty_module = arenas.new_module(
1214 ModuleKind::Def(DefKind::Mod, root_def_id, kw::Empty),
1218 &mut FxHashMap::default(),
1221 let definitions = Definitions::new(session.local_stable_crate_id());
1223 let mut visibilities = FxHashMap::default();
1224 visibilities.insert(CRATE_DEF_ID, ty::Visibility::Public);
1226 let mut def_id_to_node_id = IndexVec::default();
1227 assert_eq!(def_id_to_node_id.push(CRATE_NODE_ID), CRATE_DEF_ID);
1228 let mut node_id_to_def_id = FxHashMap::default();
1229 node_id_to_def_id.insert(CRATE_NODE_ID, CRATE_DEF_ID);
1231 let mut invocation_parents = FxHashMap::default();
1232 invocation_parents.insert(LocalExpnId::ROOT, (CRATE_DEF_ID, ImplTraitContext::Existential));
1234 let mut source_span = IndexVec::default();
1235 let _id = source_span.push(krate.spans.inner_span);
1236 debug_assert_eq!(_id, CRATE_DEF_ID);
1238 let mut extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'_>> = session
1242 .filter(|(_, entry)| entry.add_prelude)
1243 .map(|(name, _)| (Ident::from_str(name), Default::default()))
1246 if !session.contains_name(&krate.attrs, sym::no_core) {
1247 extern_prelude.insert(Ident::with_dummy_span(sym::core), Default::default());
1248 if !session.contains_name(&krate.attrs, sym::no_std) {
1249 extern_prelude.insert(Ident::with_dummy_span(sym::std), Default::default());
1253 let registered_tools = macros::registered_tools(session, &krate.attrs);
1255 let features = session.features_untracked();
1257 let mut resolver = Resolver {
1261 expn_that_defined: Default::default(),
1264 // The outermost module has def ID 0; this is not reflected in the
1270 has_self: FxHashSet::default(),
1271 field_names: FxHashMap::default(),
1273 determined_imports: Vec::new(),
1274 indeterminate_imports: Vec::new(),
1276 pat_span_map: Default::default(),
1277 partial_res_map: Default::default(),
1278 import_res_map: Default::default(),
1279 label_res_map: Default::default(),
1280 lifetimes_res_map: Default::default(),
1281 generics_def_id_map: Vec::new(),
1282 extra_lifetime_params_map: Default::default(),
1283 extern_crate_map: Default::default(),
1284 reexport_map: FxHashMap::default(),
1285 trait_map: NodeMap::default(),
1286 underscore_disambiguator: 0,
1289 block_map: Default::default(),
1290 binding_parent_modules: FxHashMap::default(),
1291 ast_transform_scopes: FxHashMap::default(),
1293 glob_map: Default::default(),
1295 has_pub_restricted: false,
1296 used_imports: FxHashSet::default(),
1297 maybe_unused_trait_imports: Default::default(),
1298 maybe_unused_extern_crates: Vec::new(),
1300 privacy_errors: Vec::new(),
1301 ambiguity_errors: Vec::new(),
1302 use_injections: Vec::new(),
1303 macro_expanded_macro_export_errors: BTreeSet::new(),
1306 dummy_binding: arenas.alloc_name_binding(NameBinding {
1307 kind: NameBindingKind::Res(Res::Err, false),
1309 expansion: LocalExpnId::ROOT,
1311 vis: ty::Visibility::Public,
1314 crate_loader: CrateLoader::new(session, metadata_loader, crate_name),
1315 macro_names: FxHashSet::default(),
1316 builtin_macros: Default::default(),
1317 builtin_macro_kinds: Default::default(),
1319 macro_use_prelude: FxHashMap::default(),
1320 macro_map: FxHashMap::default(),
1321 dummy_ext_bang: Lrc::new(SyntaxExtension::dummy_bang(session.edition())),
1322 dummy_ext_derive: Lrc::new(SyntaxExtension::dummy_derive(session.edition())),
1323 non_macro_attr: Lrc::new(SyntaxExtension::non_macro_attr(session.edition())),
1324 invocation_parent_scopes: Default::default(),
1325 output_macro_rules_scopes: Default::default(),
1326 macro_rules_scopes: Default::default(),
1327 helper_attrs: Default::default(),
1328 derive_data: Default::default(),
1329 local_macro_def_scopes: FxHashMap::default(),
1330 name_already_seen: FxHashMap::default(),
1331 potentially_unused_imports: Vec::new(),
1332 struct_constructors: Default::default(),
1333 unused_macros: Default::default(),
1334 unused_macro_rules: Default::default(),
1335 proc_macro_stubs: Default::default(),
1336 single_segment_macro_resolutions: Default::default(),
1337 multi_segment_macro_resolutions: Default::default(),
1338 builtin_attrs: Default::default(),
1339 containers_deriving_copy: Default::default(),
1340 active_features: features
1341 .declared_lib_features
1343 .map(|(feat, ..)| *feat)
1344 .chain(features.declared_lang_features.iter().map(|(feat, ..)| *feat))
1346 lint_buffer: LintBuffer::default(),
1347 next_node_id: CRATE_NODE_ID,
1350 placeholder_field_indices: Default::default(),
1352 trait_impl_items: Default::default(),
1353 legacy_const_generic_args: Default::default(),
1354 item_generics_num_lifetimes: Default::default(),
1355 main_def: Default::default(),
1356 trait_impls: Default::default(),
1357 proc_macros: Default::default(),
1358 confused_type_with_std_module: Default::default(),
1359 access_levels: Default::default(),
1362 let root_parent_scope = ParentScope::module(graph_root, &resolver);
1363 resolver.invocation_parent_scopes.insert(LocalExpnId::ROOT, root_parent_scope);
1370 parent: Option<Module<'a>>,
1374 no_implicit_prelude: bool,
1376 let module_map = &mut self.module_map;
1377 self.arenas.new_module(parent, kind, expn_id, span, no_implicit_prelude, module_map)
1380 pub fn next_node_id(&mut self) -> NodeId {
1381 let start = self.next_node_id;
1382 let next = start.as_u32().checked_add(1).expect("input too large; ran out of NodeIds");
1383 self.next_node_id = ast::NodeId::from_u32(next);
1387 pub fn next_node_ids(&mut self, count: usize) -> std::ops::Range<NodeId> {
1388 let start = self.next_node_id;
1389 let end = start.as_usize().checked_add(count).expect("input too large; ran out of NodeIds");
1390 self.next_node_id = ast::NodeId::from_usize(end);
1391 start..self.next_node_id
1394 pub fn lint_buffer(&mut self) -> &mut LintBuffer {
1395 &mut self.lint_buffer
1398 pub fn arenas() -> ResolverArenas<'a> {
1402 pub fn into_outputs(
1404 ) -> (Definitions, Box<CrateStoreDyn>, ResolverOutputs, ty::ResolverAstLowering) {
1405 let proc_macros = self.proc_macros.iter().map(|id| self.local_def_id(*id)).collect();
1406 let definitions = self.definitions;
1407 let cstore = Box::new(self.crate_loader.into_cstore());
1408 let source_span = self.source_span;
1409 let expn_that_defined = self.expn_that_defined;
1410 let visibilities = self.visibilities;
1411 let has_pub_restricted = self.has_pub_restricted;
1412 let extern_crate_map = self.extern_crate_map;
1413 let reexport_map = self.reexport_map;
1414 let maybe_unused_trait_imports = self.maybe_unused_trait_imports;
1415 let maybe_unused_extern_crates = self.maybe_unused_extern_crates;
1416 let glob_map = self.glob_map;
1417 let main_def = self.main_def;
1418 let confused_type_with_std_module = self.confused_type_with_std_module;
1419 let access_levels = self.access_levels;
1420 let resolutions = ResolverOutputs {
1429 maybe_unused_trait_imports,
1430 maybe_unused_extern_crates,
1431 extern_prelude: self
1434 .map(|(ident, entry)| (ident.name, entry.introduced_by_item))
1437 trait_impls: self.trait_impls,
1439 confused_type_with_std_module,
1440 registered_tools: self.registered_tools,
1442 let resolutions_lowering = ty::ResolverAstLowering {
1443 legacy_const_generic_args: self.legacy_const_generic_args,
1444 partial_res_map: self.partial_res_map,
1445 import_res_map: self.import_res_map,
1446 label_res_map: self.label_res_map,
1447 lifetimes_res_map: self.lifetimes_res_map,
1448 generics_def_id_map: self.generics_def_id_map,
1449 extra_lifetime_params_map: self.extra_lifetime_params_map,
1450 next_node_id: self.next_node_id,
1451 node_id_to_def_id: self.node_id_to_def_id,
1452 def_id_to_node_id: self.def_id_to_node_id,
1453 trait_map: self.trait_map,
1454 builtin_macro_kinds: self.builtin_macro_kinds,
1456 (definitions, cstore, resolutions, resolutions_lowering)
1459 pub fn clone_outputs(
1461 ) -> (Definitions, Box<CrateStoreDyn>, ResolverOutputs, ty::ResolverAstLowering) {
1462 let proc_macros = self.proc_macros.iter().map(|id| self.local_def_id(*id)).collect();
1463 let definitions = self.definitions.clone();
1464 let cstore = Box::new(self.cstore().clone());
1465 let resolutions = ResolverOutputs {
1466 source_span: self.source_span.clone(),
1467 expn_that_defined: self.expn_that_defined.clone(),
1468 visibilities: self.visibilities.clone(),
1469 has_pub_restricted: self.has_pub_restricted,
1470 extern_crate_map: self.extern_crate_map.clone(),
1471 reexport_map: self.reexport_map.clone(),
1472 glob_map: self.glob_map.clone(),
1473 maybe_unused_trait_imports: self.maybe_unused_trait_imports.clone(),
1474 maybe_unused_extern_crates: self.maybe_unused_extern_crates.clone(),
1475 extern_prelude: self
1478 .map(|(ident, entry)| (ident.name, entry.introduced_by_item))
1480 main_def: self.main_def,
1481 trait_impls: self.trait_impls.clone(),
1483 confused_type_with_std_module: self.confused_type_with_std_module.clone(),
1484 registered_tools: self.registered_tools.clone(),
1485 access_levels: self.access_levels.clone(),
1487 let resolutions_lowering = ty::ResolverAstLowering {
1488 legacy_const_generic_args: self.legacy_const_generic_args.clone(),
1489 partial_res_map: self.partial_res_map.clone(),
1490 import_res_map: self.import_res_map.clone(),
1491 label_res_map: self.label_res_map.clone(),
1492 lifetimes_res_map: self.lifetimes_res_map.clone(),
1493 generics_def_id_map: self.generics_def_id_map.clone(),
1494 extra_lifetime_params_map: self.extra_lifetime_params_map.clone(),
1495 next_node_id: self.next_node_id.clone(),
1496 node_id_to_def_id: self.node_id_to_def_id.clone(),
1497 def_id_to_node_id: self.def_id_to_node_id.clone(),
1498 trait_map: self.trait_map.clone(),
1499 builtin_macro_kinds: self.builtin_macro_kinds.clone(),
1501 (definitions, cstore, resolutions, resolutions_lowering)
1504 fn create_stable_hashing_context(&self) -> StableHashingContext<'_> {
1505 StableHashingContext::new(
1508 self.crate_loader.cstore(),
1513 pub fn cstore(&self) -> &CStore {
1514 self.crate_loader.cstore()
1517 fn dummy_ext(&self, macro_kind: MacroKind) -> Lrc<SyntaxExtension> {
1519 MacroKind::Bang => self.dummy_ext_bang.clone(),
1520 MacroKind::Derive => self.dummy_ext_derive.clone(),
1521 MacroKind::Attr => self.non_macro_attr.clone(),
1525 /// Runs the function on each namespace.
1526 fn per_ns<F: FnMut(&mut Self, Namespace)>(&mut self, mut f: F) {
1532 fn is_builtin_macro(&mut self, res: Res) -> bool {
1533 self.get_macro(res).map_or(false, |macro_data| macro_data.ext.builtin_name.is_some())
1536 fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
1538 match ctxt.outer_expn_data().macro_def_id {
1539 Some(def_id) => return def_id,
1540 None => ctxt.remove_mark(),
1545 /// Entry point to crate resolution.
1546 pub fn resolve_crate(&mut self, krate: &Crate) {
1547 self.session.time("resolve_crate", || {
1548 self.session.time("finalize_imports", || ImportResolver { r: self }.finalize_imports());
1549 self.session.time("resolve_access_levels", || {
1550 AccessLevelsVisitor::compute_access_levels(self, krate)
1552 self.session.time("finalize_macro_resolutions", || self.finalize_macro_resolutions());
1553 self.session.time("late_resolve_crate", || self.late_resolve_crate(krate));
1554 self.session.time("resolve_main", || self.resolve_main());
1555 self.session.time("resolve_check_unused", || self.check_unused(krate));
1556 self.session.time("resolve_report_errors", || self.report_errors(krate));
1557 self.session.time("resolve_postprocess", || self.crate_loader.postprocess(krate));
1561 pub fn traits_in_scope(
1563 current_trait: Option<Module<'a>>,
1564 parent_scope: &ParentScope<'a>,
1565 ctxt: SyntaxContext,
1566 assoc_item: Option<(Symbol, Namespace)>,
1567 ) -> Vec<TraitCandidate> {
1568 let mut found_traits = Vec::new();
1570 if let Some(module) = current_trait {
1571 if self.trait_may_have_item(Some(module), assoc_item) {
1572 let def_id = module.def_id();
1573 found_traits.push(TraitCandidate { def_id, import_ids: smallvec![] });
1577 self.visit_scopes(ScopeSet::All(TypeNS, false), parent_scope, ctxt, |this, scope, _, _| {
1579 Scope::Module(module, _) => {
1580 this.traits_in_module(module, assoc_item, &mut found_traits);
1582 Scope::StdLibPrelude => {
1583 if let Some(module) = this.prelude {
1584 this.traits_in_module(module, assoc_item, &mut found_traits);
1587 Scope::ExternPrelude | Scope::ToolPrelude | Scope::BuiltinTypes => {}
1588 _ => unreachable!(),
1596 fn traits_in_module(
1599 assoc_item: Option<(Symbol, Namespace)>,
1600 found_traits: &mut Vec<TraitCandidate>,
1602 module.ensure_traits(self);
1603 let traits = module.traits.borrow();
1604 for (trait_name, trait_binding) in traits.as_ref().unwrap().iter() {
1605 if self.trait_may_have_item(trait_binding.module(), assoc_item) {
1606 let def_id = trait_binding.res().def_id();
1607 let import_ids = self.find_transitive_imports(&trait_binding.kind, *trait_name);
1608 found_traits.push(TraitCandidate { def_id, import_ids });
1613 // List of traits in scope is pruned on best effort basis. We reject traits not having an
1614 // associated item with the given name and namespace (if specified). This is a conservative
1615 // optimization, proper hygienic type-based resolution of associated items is done in typeck.
1616 // We don't reject trait aliases (`trait_module == None`) because we don't have access to their
1617 // associated items.
1618 fn trait_may_have_item(
1620 trait_module: Option<Module<'a>>,
1621 assoc_item: Option<(Symbol, Namespace)>,
1623 match (trait_module, assoc_item) {
1624 (Some(trait_module), Some((name, ns))) => {
1625 self.resolutions(trait_module).borrow().iter().any(|resolution| {
1626 let (&BindingKey { ident: assoc_ident, ns: assoc_ns, .. }, _) = resolution;
1627 assoc_ns == ns && assoc_ident.name == name
1634 fn find_transitive_imports(
1636 mut kind: &NameBindingKind<'_>,
1638 ) -> SmallVec<[LocalDefId; 1]> {
1639 let mut import_ids = smallvec![];
1640 while let NameBindingKind::Import { import, binding, .. } = kind {
1641 let id = self.local_def_id(import.id);
1642 self.maybe_unused_trait_imports.insert(id);
1643 self.add_to_glob_map(&import, trait_name);
1644 import_ids.push(id);
1645 kind = &binding.kind;
1650 fn new_key(&mut self, ident: Ident, ns: Namespace) -> BindingKey {
1651 let ident = ident.normalize_to_macros_2_0();
1652 let disambiguator = if ident.name == kw::Underscore {
1653 self.underscore_disambiguator += 1;
1654 self.underscore_disambiguator
1658 BindingKey { ident, ns, disambiguator }
1661 fn resolutions(&mut self, module: Module<'a>) -> &'a Resolutions<'a> {
1662 if module.populate_on_access.get() {
1663 module.populate_on_access.set(false);
1664 self.build_reduced_graph_external(module);
1666 &module.lazy_resolutions
1673 ) -> &'a RefCell<NameResolution<'a>> {
1675 .resolutions(module)
1678 .or_insert_with(|| self.arenas.alloc_name_resolution())
1684 used_binding: &'a NameBinding<'a>,
1685 is_lexical_scope: bool,
1687 if let Some((b2, kind)) = used_binding.ambiguity {
1688 self.ambiguity_errors.push(AmbiguityError {
1693 misc1: AmbiguityErrorMisc::None,
1694 misc2: AmbiguityErrorMisc::None,
1697 if let NameBindingKind::Import { import, binding, ref used } = used_binding.kind {
1698 // Avoid marking `extern crate` items that refer to a name from extern prelude,
1699 // but not introduce it, as used if they are accessed from lexical scope.
1700 if is_lexical_scope {
1701 if let Some(entry) = self.extern_prelude.get(&ident.normalize_to_macros_2_0()) {
1702 if let Some(crate_item) = entry.extern_crate_item {
1703 if ptr::eq(used_binding, crate_item) && !entry.introduced_by_item {
1710 import.used.set(true);
1711 self.used_imports.insert(import.id);
1712 self.add_to_glob_map(&import, ident);
1713 self.record_use(ident, binding, false);
1718 fn add_to_glob_map(&mut self, import: &Import<'_>, ident: Ident) {
1719 if import.is_glob() {
1720 let def_id = self.local_def_id(import.id);
1721 self.glob_map.entry(def_id).or_default().insert(ident.name);
1725 fn resolve_crate_root(&mut self, ident: Ident) -> Module<'a> {
1726 debug!("resolve_crate_root({:?})", ident);
1727 let mut ctxt = ident.span.ctxt();
1728 let mark = if ident.name == kw::DollarCrate {
1729 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
1730 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
1731 // as described in `SyntaxContext::apply_mark`, so we ignore prepended opaque marks.
1732 // FIXME: This is only a guess and it doesn't work correctly for `macro_rules!`
1733 // definitions actually produced by `macro` and `macro` definitions produced by
1734 // `macro_rules!`, but at least such configurations are not stable yet.
1735 ctxt = ctxt.normalize_to_macro_rules();
1737 "resolve_crate_root: marks={:?}",
1738 ctxt.marks().into_iter().map(|(i, t)| (i.expn_data(), t)).collect::<Vec<_>>()
1740 let mut iter = ctxt.marks().into_iter().rev().peekable();
1741 let mut result = None;
1742 // Find the last opaque mark from the end if it exists.
1743 while let Some(&(mark, transparency)) = iter.peek() {
1744 if transparency == Transparency::Opaque {
1745 result = Some(mark);
1752 "resolve_crate_root: found opaque mark {:?} {:?}",
1754 result.map(|r| r.expn_data())
1756 // Then find the last semi-transparent mark from the end if it exists.
1757 for (mark, transparency) in iter {
1758 if transparency == Transparency::SemiTransparent {
1759 result = Some(mark);
1765 "resolve_crate_root: found semi-transparent mark {:?} {:?}",
1767 result.map(|r| r.expn_data())
1771 debug!("resolve_crate_root: not DollarCrate");
1772 ctxt = ctxt.normalize_to_macros_2_0();
1773 ctxt.adjust(ExpnId::root())
1775 let module = match mark {
1776 Some(def) => self.expn_def_scope(def),
1779 "resolve_crate_root({:?}): found no mark (ident.span = {:?})",
1782 return self.graph_root;
1785 let module = self.expect_module(
1786 module.opt_def_id().map_or(LOCAL_CRATE, |def_id| def_id.krate).as_def_id(),
1789 "resolve_crate_root({:?}): got module {:?} ({:?}) (ident.span = {:?})",
1798 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
1799 let mut module = self.expect_module(module.nearest_parent_mod());
1800 while module.span.ctxt().normalize_to_macros_2_0() != *ctxt {
1801 let parent = module.parent.unwrap_or_else(|| self.expn_def_scope(ctxt.remove_mark()));
1802 module = self.expect_module(parent.nearest_parent_mod());
1807 fn record_partial_res(&mut self, node_id: NodeId, resolution: PartialRes) {
1808 debug!("(recording res) recording {:?} for {}", resolution, node_id);
1809 if let Some(prev_res) = self.partial_res_map.insert(node_id, resolution) {
1810 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
1814 fn record_pat_span(&mut self, node: NodeId, span: Span) {
1815 debug!("(recording pat) recording {:?} for {:?}", node, span);
1816 self.pat_span_map.insert(node, span);
1819 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
1820 vis.is_accessible_from(module.nearest_parent_mod(), self)
1823 fn set_binding_parent_module(&mut self, binding: &'a NameBinding<'a>, module: Module<'a>) {
1824 if let Some(old_module) =
1825 self.binding_parent_modules.insert(Interned::new_unchecked(binding), module)
1827 if !ptr::eq(module, old_module) {
1828 span_bug!(binding.span, "parent module is reset for binding");
1833 fn disambiguate_macro_rules_vs_modularized(
1835 macro_rules: &'a NameBinding<'a>,
1836 modularized: &'a NameBinding<'a>,
1838 // Some non-controversial subset of ambiguities "modularized macro name" vs "macro_rules"
1839 // is disambiguated to mitigate regressions from macro modularization.
1840 // Scoping for `macro_rules` behaves like scoping for `let` at module level, in general.
1842 self.binding_parent_modules.get(&Interned::new_unchecked(macro_rules)),
1843 self.binding_parent_modules.get(&Interned::new_unchecked(modularized)),
1845 (Some(macro_rules), Some(modularized)) => {
1846 macro_rules.nearest_parent_mod() == modularized.nearest_parent_mod()
1847 && modularized.is_ancestor_of(macro_rules)
1853 fn extern_prelude_get(&mut self, ident: Ident, finalize: bool) -> Option<&'a NameBinding<'a>> {
1854 if ident.is_path_segment_keyword() {
1855 // Make sure `self`, `super` etc produce an error when passed to here.
1858 self.extern_prelude.get(&ident.normalize_to_macros_2_0()).cloned().and_then(|entry| {
1859 if let Some(binding) = entry.extern_crate_item {
1860 if finalize && entry.introduced_by_item {
1861 self.record_use(ident, binding, false);
1865 let crate_id = if finalize {
1866 let Some(crate_id) =
1867 self.crate_loader.process_path_extern(ident.name, ident.span) else { return Some(self.dummy_binding); };
1870 self.crate_loader.maybe_process_path_extern(ident.name)?
1872 let crate_root = self.expect_module(crate_id.as_def_id());
1874 (crate_root, ty::Visibility::Public, DUMMY_SP, LocalExpnId::ROOT)
1875 .to_name_binding(self.arenas),
1881 /// Rustdoc uses this to resolve doc link paths in a recoverable way. `PathResult<'a>`
1882 /// isn't something that can be returned because it can't be made to live that long,
1883 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
1884 /// just that an error occurred.
1885 pub fn resolve_rustdoc_path(
1889 mut parent_scope: ParentScope<'a>,
1892 Vec::from_iter(path_str.split("::").map(Ident::from_str).map(Segment::from_ident));
1893 if let Some(segment) = segments.first_mut() {
1894 if segment.ident.name == kw::Crate {
1895 // FIXME: `resolve_path` always resolves `crate` to the current crate root, but
1896 // rustdoc wants it to resolve to the `parent_scope`'s crate root. This trick of
1897 // replacing `crate` with `self` and changing the current module should achieve
1899 segment.ident.name = kw::SelfLower;
1900 parent_scope.module =
1901 self.expect_module(parent_scope.module.def_id().krate.as_def_id());
1902 } else if segment.ident.name == kw::Empty {
1903 segment.ident.name = kw::PathRoot;
1907 match self.maybe_resolve_path(&segments, Some(ns), &parent_scope) {
1908 PathResult::Module(ModuleOrUniformRoot::Module(module)) => Some(module.res().unwrap()),
1909 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 => {
1910 Some(path_res.base_res())
1912 PathResult::Module(ModuleOrUniformRoot::ExternPrelude)
1913 | PathResult::NonModule(..)
1914 | PathResult::Failed { .. } => None,
1915 PathResult::Module(..) | PathResult::Indeterminate => unreachable!(),
1920 /// For local modules returns only reexports, for external modules returns all children.
1921 pub fn module_children_or_reexports(&self, def_id: DefId) -> Vec<ModChild> {
1922 if let Some(def_id) = def_id.as_local() {
1923 self.reexport_map.get(&def_id).cloned().unwrap_or_default()
1925 self.cstore().module_children_untracked(def_id, self.session)
1930 pub fn macro_rules_scope(&self, def_id: LocalDefId) -> (MacroRulesScopeRef<'a>, Res) {
1931 let scope = *self.macro_rules_scopes.get(&def_id).expect("not a `macro_rules` item");
1933 MacroRulesScope::Binding(mb) => (scope, mb.binding.res()),
1934 _ => unreachable!(),
1938 /// Retrieves the span of the given `DefId` if `DefId` is in the local crate.
1940 pub fn opt_span(&self, def_id: DefId) -> Option<Span> {
1941 def_id.as_local().map(|def_id| self.source_span[def_id])
1944 /// Retrieves the name of the given `DefId`.
1946 pub fn opt_name(&self, def_id: DefId) -> Option<Symbol> {
1947 let def_key = match def_id.as_local() {
1948 Some(def_id) => self.definitions.def_key(def_id),
1949 None => self.cstore().def_key(def_id),
1951 def_key.get_opt_name()
1954 /// Checks if an expression refers to a function marked with
1955 /// `#[rustc_legacy_const_generics]` and returns the argument index list
1956 /// from the attribute.
1957 pub fn legacy_const_generic_args(&mut self, expr: &Expr) -> Option<Vec<usize>> {
1958 if let ExprKind::Path(None, path) = &expr.kind {
1959 // Don't perform legacy const generics rewriting if the path already
1960 // has generic arguments.
1961 if path.segments.last().unwrap().args.is_some() {
1965 let partial_res = self.partial_res_map.get(&expr.id)?;
1966 if partial_res.unresolved_segments() != 0 {
1970 if let Res::Def(def::DefKind::Fn, def_id) = partial_res.base_res() {
1971 // We only support cross-crate argument rewriting. Uses
1972 // within the same crate should be updated to use the new
1973 // const generics style.
1974 if def_id.is_local() {
1978 if let Some(v) = self.legacy_const_generic_args.get(&def_id) {
1984 .item_attrs_untracked(def_id, self.session)
1985 .find(|a| a.has_name(sym::rustc_legacy_const_generics))?;
1986 let mut ret = Vec::new();
1987 for meta in attr.meta_item_list()? {
1988 match meta.literal()?.kind {
1989 LitKind::Int(a, _) => ret.push(a as usize),
1990 _ => panic!("invalid arg index"),
1993 // Cache the lookup to avoid parsing attributes for an item multiple times.
1994 self.legacy_const_generic_args.insert(def_id, Some(ret.clone()));
2001 fn resolve_main(&mut self) {
2002 let module = self.graph_root;
2003 let ident = Ident::with_dummy_span(sym::main);
2004 let parent_scope = &ParentScope::module(module, self);
2006 let Ok(name_binding) = self.maybe_resolve_ident_in_module(
2007 ModuleOrUniformRoot::Module(module),
2015 let res = name_binding.res();
2016 let is_import = name_binding.is_import();
2017 let span = name_binding.span;
2018 if let Res::Def(DefKind::Fn, _) = res {
2019 self.record_use(ident, name_binding, false);
2021 self.main_def = Some(MainDefinition { res, is_import, span });
2025 fn names_to_string(names: &[Symbol]) -> String {
2026 let mut result = String::new();
2027 for (i, name) in names.iter().filter(|name| **name != kw::PathRoot).enumerate() {
2029 result.push_str("::");
2031 if Ident::with_dummy_span(*name).is_raw_guess() {
2032 result.push_str("r#");
2034 result.push_str(name.as_str());
2039 fn path_names_to_string(path: &Path) -> String {
2040 names_to_string(&path.segments.iter().map(|seg| seg.ident.name).collect::<Vec<_>>())
2043 /// A somewhat inefficient routine to obtain the name of a module.
2044 fn module_to_string(module: Module<'_>) -> Option<String> {
2045 let mut names = Vec::new();
2047 fn collect_mod(names: &mut Vec<Symbol>, module: Module<'_>) {
2048 if let ModuleKind::Def(.., name) = module.kind {
2049 if let Some(parent) = module.parent {
2051 collect_mod(names, parent);
2054 names.push(Symbol::intern("<opaque>"));
2055 collect_mod(names, module.parent.unwrap());
2058 collect_mod(&mut names, module);
2060 if names.is_empty() {
2064 Some(names_to_string(&names))
2067 #[derive(Copy, Clone, Debug)]
2069 /// Node ID for linting.
2071 /// Span of the whole path or some its characteristic fragment.
2072 /// E.g. span of `b` in `foo::{a, b, c}`, or full span for regular paths.
2074 /// Span of the path start, suitable for prepending something to to it.
2075 /// E.g. span of `foo` in `foo::{a, b, c}`, or full span for regular paths.
2077 /// Whether to report privacy errors or silently return "no resolution" for them,
2078 /// similarly to speculative resolution.
2079 report_private: bool,
2083 fn new(node_id: NodeId, path_span: Span) -> Finalize {
2084 Finalize::with_root_span(node_id, path_span, path_span)
2087 fn with_root_span(node_id: NodeId, path_span: Span, root_span: Span) -> Finalize {
2088 Finalize { node_id, path_span, root_span, report_private: true }
2092 pub fn provide(providers: &mut Providers) {
2093 late::lifetimes::provide(providers);