1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // Do not remove on snapshot creation. Needed for bootstrap. (Issue #22364)
12 #![cfg_attr(stage0, feature(custom_attribute))]
13 #![crate_name = "rustc_resolve"]
14 #![unstable(feature = "rustc_private", issue = "27812")]
15 #![cfg_attr(stage0, staged_api)]
16 #![crate_type = "dylib"]
17 #![crate_type = "rlib"]
18 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
19 html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
20 html_root_url = "https://doc.rust-lang.org/nightly/")]
22 #![feature(associated_consts)]
23 #![feature(borrow_state)]
24 #![feature(rustc_diagnostic_macros)]
25 #![feature(rustc_private)]
26 #![feature(staged_api)]
34 extern crate rustc_bitflags;
35 extern crate rustc_front;
39 use self::PatternBindingMode::*;
40 use self::Namespace::*;
41 use self::NamespaceResult::*;
42 use self::ResolveResult::*;
43 use self::FallbackSuggestion::*;
44 use self::TypeParameters::*;
46 use self::UseLexicalScopeFlag::*;
47 use self::ModulePrefixResult::*;
48 use self::AssocItemResolveResult::*;
49 use self::NameSearchType::*;
50 use self::BareIdentifierPatternResolution::*;
51 use self::ParentLink::*;
52 use self::FallbackChecks::*;
54 use rustc::front::map as hir_map;
55 use rustc::session::Session;
57 use rustc::middle::cstore::{CrateStore, DefLike, DlDef};
58 use rustc::middle::def::*;
59 use rustc::middle::def_id::DefId;
60 use rustc::middle::pat_util::pat_bindings;
61 use rustc::middle::privacy::*;
62 use rustc::middle::subst::{ParamSpace, FnSpace, TypeSpace};
63 use rustc::middle::ty::{Freevar, FreevarMap, TraitMap, GlobMap};
64 use rustc::util::nodemap::{NodeMap, DefIdSet, FnvHashMap};
67 use syntax::ast::{CRATE_NODE_ID, Ident, Name, NodeId, CrateNum, TyIs, TyI8, TyI16, TyI32, TyI64};
68 use syntax::ast::{TyUs, TyU8, TyU16, TyU32, TyU64, TyF64, TyF32};
69 use syntax::attr::AttrMetaMethods;
70 use syntax::parse::token::{self, special_names, special_idents};
71 use syntax::codemap::{self, Span, Pos};
72 use syntax::util::lev_distance::{lev_distance, max_suggestion_distance};
74 use rustc_front::intravisit::{self, FnKind, Visitor};
76 use rustc_front::hir::{Arm, BindByRef, BindByValue, BindingMode, Block};
77 use rustc_front::hir::Crate;
78 use rustc_front::hir::{Expr, ExprAgain, ExprBreak, ExprField};
79 use rustc_front::hir::{ExprLoop, ExprWhile, ExprMethodCall};
80 use rustc_front::hir::{ExprPath, ExprStruct, FnDecl};
81 use rustc_front::hir::{ForeignItemFn, ForeignItemStatic, Generics};
82 use rustc_front::hir::{ImplItem, Item, ItemConst, ItemEnum, ItemExternCrate};
83 use rustc_front::hir::{ItemFn, ItemForeignMod, ItemImpl, ItemMod, ItemStatic, ItemDefaultImpl};
84 use rustc_front::hir::{ItemStruct, ItemTrait, ItemTy, ItemUse};
85 use rustc_front::hir::Local;
86 use rustc_front::hir::{Pat, PatEnum, PatIdent, PatLit, PatQPath};
87 use rustc_front::hir::{PatRange, PatStruct, Path, PrimTy};
88 use rustc_front::hir::{TraitRef, Ty, TyBool, TyChar, TyFloat, TyInt};
89 use rustc_front::hir::{TyRptr, TyStr, TyUint, TyPath, TyPtr};
90 use rustc_front::util::walk_pat;
92 use std::collections::{HashMap, HashSet};
93 use std::cell::{Cell, RefCell};
95 use std::mem::replace;
96 use std::rc::{Rc, Weak};
99 use resolve_imports::{Target, ImportDirective, ImportResolution};
100 use resolve_imports::Shadowable;
102 // NB: This module needs to be declared first so diagnostics are
103 // registered before they are used.
108 mod build_reduced_graph;
111 // Perform the callback, not walking deeper if the return is true
112 macro_rules! execute_callback {
113 ($node: expr, $walker: expr) => (
114 if let Some(ref callback) = $walker.callback {
115 if callback($node, &mut $walker.resolved) {
122 enum SuggestionType {
128 pub enum ResolutionError<'a> {
129 /// error E0401: can't use type parameters from outer function
130 TypeParametersFromOuterFunction,
131 /// error E0402: cannot use an outer type parameter in this context
132 OuterTypeParameterContext,
133 /// error E0403: the name is already used for a type parameter in this type parameter list
134 NameAlreadyUsedInTypeParameterList(Name),
135 /// error E0404: is not a trait
136 IsNotATrait(&'a str),
137 /// error E0405: use of undeclared trait name
138 UndeclaredTraitName(&'a str),
139 /// error E0406: undeclared associated type
140 UndeclaredAssociatedType,
141 /// error E0407: method is not a member of trait
142 MethodNotMemberOfTrait(Name, &'a str),
143 /// error E0437: type is not a member of trait
144 TypeNotMemberOfTrait(Name, &'a str),
145 /// error E0438: const is not a member of trait
146 ConstNotMemberOfTrait(Name, &'a str),
147 /// error E0408: variable `{}` from pattern #1 is not bound in pattern
148 VariableNotBoundInPattern(Name, usize),
149 /// error E0409: variable is bound with different mode in pattern #{} than in pattern #1
150 VariableBoundWithDifferentMode(Name, usize),
151 /// error E0410: variable from pattern is not bound in pattern #1
152 VariableNotBoundInParentPattern(Name, usize),
153 /// error E0411: use of `Self` outside of an impl or trait
154 SelfUsedOutsideImplOrTrait,
155 /// error E0412: use of undeclared
156 UseOfUndeclared(&'a str, &'a str),
157 /// error E0413: declaration shadows an enum variant or unit-like struct in scope
158 DeclarationShadowsEnumVariantOrUnitLikeStruct(Name),
159 /// error E0414: only irrefutable patterns allowed here
160 OnlyIrrefutablePatternsAllowedHere(DefId, Name),
161 /// error E0415: identifier is bound more than once in this parameter list
162 IdentifierBoundMoreThanOnceInParameterList(&'a str),
163 /// error E0416: identifier is bound more than once in the same pattern
164 IdentifierBoundMoreThanOnceInSamePattern(&'a str),
165 /// error E0417: static variables cannot be referenced in a pattern
166 StaticVariableReference,
167 /// error E0418: is not an enum variant, struct or const
168 NotAnEnumVariantStructOrConst(&'a str),
169 /// error E0419: unresolved enum variant, struct or const
170 UnresolvedEnumVariantStructOrConst(&'a str),
171 /// error E0420: is not an associated const
172 NotAnAssociatedConst(&'a str),
173 /// error E0421: unresolved associated const
174 UnresolvedAssociatedConst(&'a str),
175 /// error E0422: does not name a struct
176 DoesNotNameAStruct(&'a str),
177 /// error E0423: is a struct variant name, but this expression uses it like a function name
178 StructVariantUsedAsFunction(&'a str),
179 /// error E0424: `self` is not available in a static method
180 SelfNotAvailableInStaticMethod,
181 /// error E0425: unresolved name
182 UnresolvedName(&'a str, &'a str),
183 /// error E0426: use of undeclared label
184 UndeclaredLabel(&'a str),
185 /// error E0427: cannot use `ref` binding mode with ...
186 CannotUseRefBindingModeWith(&'a str),
187 /// error E0428: duplicate definition
188 DuplicateDefinition(&'a str, Name),
189 /// error E0429: `self` imports are only allowed within a { } list
190 SelfImportsOnlyAllowedWithin,
191 /// error E0430: `self` import can only appear once in the list
192 SelfImportCanOnlyAppearOnceInTheList,
193 /// error E0431: `self` import can only appear in an import list with a non-empty prefix
194 SelfImportOnlyInImportListWithNonEmptyPrefix,
195 /// error E0432: unresolved import
196 UnresolvedImport(Option<(&'a str, &'a str)>),
197 /// error E0433: failed to resolve
198 FailedToResolve(&'a str),
199 /// error E0434: can't capture dynamic environment in a fn item
200 CannotCaptureDynamicEnvironmentInFnItem,
201 /// error E0435: attempt to use a non-constant value in a constant
202 AttemptToUseNonConstantValueInConstant,
205 fn resolve_error<'b, 'a: 'b, 'tcx: 'a>(resolver: &'b Resolver<'a, 'tcx>,
206 span: syntax::codemap::Span,
207 resolution_error: ResolutionError<'b>) {
208 if !resolver.emit_errors {
211 match resolution_error {
212 ResolutionError::TypeParametersFromOuterFunction => {
213 span_err!(resolver.session,
216 "can't use type parameters from outer function; try using a local type \
219 ResolutionError::OuterTypeParameterContext => {
220 span_err!(resolver.session,
223 "cannot use an outer type parameter in this context");
225 ResolutionError::NameAlreadyUsedInTypeParameterList(name) => {
226 span_err!(resolver.session,
229 "the name `{}` is already used for a type parameter in this type parameter \
233 ResolutionError::IsNotATrait(name) => {
234 span_err!(resolver.session, span, E0404, "`{}` is not a trait", name);
236 ResolutionError::UndeclaredTraitName(name) => {
237 span_err!(resolver.session,
240 "use of undeclared trait name `{}`",
243 ResolutionError::UndeclaredAssociatedType => {
244 span_err!(resolver.session, span, E0406, "undeclared associated type");
246 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
247 span_err!(resolver.session,
250 "method `{}` is not a member of trait `{}`",
254 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
255 span_err!(resolver.session,
258 "type `{}` is not a member of trait `{}`",
262 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
263 span_err!(resolver.session,
266 "const `{}` is not a member of trait `{}`",
270 ResolutionError::VariableNotBoundInPattern(variable_name, pattern_number) => {
271 span_err!(resolver.session,
274 "variable `{}` from pattern #1 is not bound in pattern #{}",
278 ResolutionError::VariableBoundWithDifferentMode(variable_name, pattern_number) => {
279 span_err!(resolver.session,
282 "variable `{}` is bound with different mode in pattern #{} than in pattern \
287 ResolutionError::VariableNotBoundInParentPattern(variable_name, pattern_number) => {
288 span_err!(resolver.session,
291 "variable `{}` from pattern #{} is not bound in pattern #1",
295 ResolutionError::SelfUsedOutsideImplOrTrait => {
296 span_err!(resolver.session,
299 "use of `Self` outside of an impl or trait");
301 ResolutionError::UseOfUndeclared(kind, name) => {
302 span_err!(resolver.session,
305 "use of undeclared {} `{}`",
309 ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(name) => {
310 span_err!(resolver.session,
313 "declaration of `{}` shadows an enum variant or unit-like struct in scope",
316 ResolutionError::OnlyIrrefutablePatternsAllowedHere(did, name) => {
317 span_err!(resolver.session,
320 "only irrefutable patterns allowed here");
321 resolver.session.span_note(span,
322 "there already is a constant in scope sharing the same \
323 name as this pattern");
324 if let Some(sp) = resolver.ast_map.span_if_local(did) {
325 resolver.session.span_note(sp, "constant defined here");
327 if let Some(directive) = resolver.current_module
331 let item = resolver.ast_map.expect_item(directive.value_ns.id);
332 resolver.session.span_note(item.span, "constant imported here");
335 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
336 span_err!(resolver.session,
339 "identifier `{}` is bound more than once in this parameter list",
342 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
343 span_err!(resolver.session,
346 "identifier `{}` is bound more than once in the same pattern",
349 ResolutionError::StaticVariableReference => {
350 span_err!(resolver.session,
353 "static variables cannot be referenced in a pattern, use a `const` instead");
355 ResolutionError::NotAnEnumVariantStructOrConst(name) => {
356 span_err!(resolver.session,
359 "`{}` is not an enum variant, struct or const",
362 ResolutionError::UnresolvedEnumVariantStructOrConst(name) => {
363 span_err!(resolver.session,
366 "unresolved enum variant, struct or const `{}`",
369 ResolutionError::NotAnAssociatedConst(name) => {
370 span_err!(resolver.session,
373 "`{}` is not an associated const",
376 ResolutionError::UnresolvedAssociatedConst(name) => {
377 span_err!(resolver.session,
380 "unresolved associated const `{}`",
383 ResolutionError::DoesNotNameAStruct(name) => {
384 span_err!(resolver.session,
387 "`{}` does not name a structure",
390 ResolutionError::StructVariantUsedAsFunction(path_name) => {
391 span_err!(resolver.session,
394 "`{}` is the name of a struct or struct variant, but this expression uses \
395 it like a function name",
398 ResolutionError::SelfNotAvailableInStaticMethod => {
399 span_err!(resolver.session,
402 "`self` is not available in a static method. Maybe a `self` argument is \
405 ResolutionError::UnresolvedName(path, name) => {
406 span_err!(resolver.session,
409 "unresolved name `{}`{}",
413 ResolutionError::UndeclaredLabel(name) => {
414 span_err!(resolver.session,
417 "use of undeclared label `{}`",
420 ResolutionError::CannotUseRefBindingModeWith(descr) => {
421 span_err!(resolver.session,
424 "cannot use `ref` binding mode with {}",
427 ResolutionError::DuplicateDefinition(namespace, name) => {
428 span_err!(resolver.session,
431 "duplicate definition of {} `{}`",
435 ResolutionError::SelfImportsOnlyAllowedWithin => {
436 span_err!(resolver.session,
440 "`self` imports are only allowed within a { } list");
442 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
443 span_err!(resolver.session,
446 "`self` import can only appear once in the list");
448 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
449 span_err!(resolver.session,
452 "`self` import can only appear in an import list with a non-empty prefix");
454 ResolutionError::UnresolvedImport(name) => {
455 let msg = match name {
456 Some((n, p)) => format!("unresolved import `{}`{}", n, p),
457 None => "unresolved import".to_owned(),
459 span_err!(resolver.session, span, E0432, "{}", msg);
461 ResolutionError::FailedToResolve(msg) => {
462 span_err!(resolver.session, span, E0433, "failed to resolve. {}", msg);
464 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
465 span_err!(resolver.session,
469 "can't capture dynamic environment in a fn item; use the || { ... } \
470 closure form instead");
472 ResolutionError::AttemptToUseNonConstantValueInConstant => {
473 span_err!(resolver.session,
476 "attempt to use a non-constant value in a constant");
481 #[derive(Copy, Clone)]
484 binding_mode: BindingMode,
487 // Map from the name in a pattern to its binding mode.
488 type BindingMap = HashMap<Name, BindingInfo>;
490 #[derive(Copy, Clone, PartialEq)]
491 enum PatternBindingMode {
493 LocalIrrefutableMode,
494 ArgumentIrrefutableMode,
497 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
503 /// A NamespaceResult represents the result of resolving an import in
504 /// a particular namespace. The result is either definitely-resolved,
505 /// definitely- unresolved, or unknown.
507 enum NamespaceResult {
508 /// Means that resolve hasn't gathered enough information yet to determine
509 /// whether the name is bound in this namespace. (That is, it hasn't
510 /// resolved all `use` directives yet.)
512 /// Means that resolve has determined that the name is definitely
513 /// not bound in the namespace.
515 /// Means that resolve has determined that the name is bound in the Module
516 /// argument, and specified by the NameBinding argument.
517 BoundResult(Rc<Module>, NameBinding),
520 impl NamespaceResult {
521 fn is_unknown(&self) -> bool {
523 UnknownResult => true,
527 fn is_unbound(&self) -> bool {
529 UnboundResult => true,
535 impl<'a, 'v, 'tcx> Visitor<'v> for Resolver<'a, 'tcx> {
536 fn visit_nested_item(&mut self, item: hir::ItemId) {
537 self.visit_item(self.ast_map.expect_item(item.id))
539 fn visit_item(&mut self, item: &Item) {
540 execute_callback!(hir_map::Node::NodeItem(item), self);
541 self.resolve_item(item);
543 fn visit_arm(&mut self, arm: &Arm) {
544 self.resolve_arm(arm);
546 fn visit_block(&mut self, block: &Block) {
547 execute_callback!(hir_map::Node::NodeBlock(block), self);
548 self.resolve_block(block);
550 fn visit_expr(&mut self, expr: &Expr) {
551 execute_callback!(hir_map::Node::NodeExpr(expr), self);
552 self.resolve_expr(expr);
554 fn visit_local(&mut self, local: &Local) {
555 execute_callback!(hir_map::Node::NodeLocal(&*local.pat), self);
556 self.resolve_local(local);
558 fn visit_ty(&mut self, ty: &Ty) {
559 self.resolve_type(ty);
561 fn visit_generics(&mut self, generics: &Generics) {
562 self.resolve_generics(generics);
564 fn visit_poly_trait_ref(&mut self, tref: &hir::PolyTraitRef, m: &hir::TraitBoundModifier) {
565 match self.resolve_trait_reference(tref.trait_ref.ref_id, &tref.trait_ref.path, 0) {
566 Ok(def) => self.record_def(tref.trait_ref.ref_id, def),
568 // error already reported
571 intravisit::walk_poly_trait_ref(self, tref, m);
573 fn visit_variant(&mut self,
574 variant: &hir::Variant,
576 item_id: ast::NodeId) {
577 execute_callback!(hir_map::Node::NodeVariant(variant), self);
578 if let Some(ref dis_expr) = variant.node.disr_expr {
579 // resolve the discriminator expr as a constant
580 self.with_constant_rib(|this| {
581 this.visit_expr(dis_expr);
585 // `intravisit::walk_variant` without the discriminant expression.
586 self.visit_variant_data(&variant.node.data,
592 fn visit_foreign_item(&mut self, foreign_item: &hir::ForeignItem) {
593 execute_callback!(hir_map::Node::NodeForeignItem(foreign_item), self);
594 let type_parameters = match foreign_item.node {
595 ForeignItemFn(_, ref generics) => {
596 HasTypeParameters(generics, FnSpace, ItemRibKind)
598 ForeignItemStatic(..) => NoTypeParameters,
600 self.with_type_parameter_rib(type_parameters, |this| {
601 intravisit::walk_foreign_item(this, foreign_item);
604 fn visit_fn(&mut self,
605 function_kind: FnKind<'v>,
606 declaration: &'v FnDecl,
610 let rib_kind = match function_kind {
611 FnKind::ItemFn(_, generics, _, _, _, _) => {
612 self.visit_generics(generics);
615 FnKind::Method(_, sig, _) => {
616 self.visit_generics(&sig.generics);
617 self.visit_explicit_self(&sig.explicit_self);
620 FnKind::Closure => ClosureRibKind(node_id),
622 self.resolve_function(rib_kind, declaration, block);
626 type ErrorMessage = Option<(Span, String)>;
628 enum ResolveResult<T> {
629 Failed(ErrorMessage), // Failed to resolve the name, optional helpful error message.
630 Indeterminate, // Couldn't determine due to unresolved globs.
631 Success(T), // Successfully resolved the import.
634 impl<T> ResolveResult<T> {
635 fn success(&self) -> bool {
643 enum FallbackSuggestion {
648 StaticMethod(String),
652 #[derive(Copy, Clone)]
653 enum TypeParameters<'a> {
655 HasTypeParameters(// Type parameters.
658 // Identifies the things that these parameters
659 // were declared on (type, fn, etc)
662 // The kind of the rib used for type parameters.
666 // The rib kind controls the translation of local
667 // definitions (`DefLocal`) to upvars (`DefUpvar`).
668 #[derive(Copy, Clone, Debug)]
670 // No translation needs to be applied.
673 // We passed through a closure scope at the given node ID.
674 // Translate upvars as appropriate.
675 ClosureRibKind(NodeId /* func id */),
677 // We passed through an impl or trait and are now in one of its
678 // methods. Allow references to ty params that impl or trait
679 // binds. Disallow any other upvars (including other ty params that are
683 // We passed through an item scope. Disallow upvars.
686 // We're in a constant item. Can't refer to dynamic stuff.
690 #[derive(Copy, Clone)]
691 enum UseLexicalScopeFlag {
696 enum ModulePrefixResult {
698 PrefixFound(Rc<Module>, usize),
701 #[derive(Copy, Clone)]
702 enum AssocItemResolveResult {
703 /// Syntax such as `<T>::item`, which can't be resolved until type
706 /// We should have been able to resolve the associated item.
707 ResolveAttempt(Option<PathResolution>),
710 #[derive(Copy, Clone, PartialEq)]
711 enum NameSearchType {
712 /// We're doing a name search in order to resolve a `use` directive.
715 /// We're doing a name search in order to resolve a path type, a path
716 /// expression, or a path pattern.
720 #[derive(Copy, Clone)]
721 enum BareIdentifierPatternResolution {
722 FoundStructOrEnumVariant(Def, LastPrivate),
723 FoundConst(Def, LastPrivate, Name),
724 BareIdentifierPatternUnresolved,
730 bindings: HashMap<Name, DefLike>,
735 fn new(kind: RibKind) -> Rib {
737 bindings: HashMap::new(),
743 /// A definition along with the index of the rib it was found on
745 ribs: Option<(Namespace, usize)>,
750 fn from_def(def: Def) -> Self {
758 /// The link from a module up to its nearest parent node.
759 #[derive(Clone,Debug)]
762 ModuleParentLink(Weak<Module>, Name),
763 BlockParentLink(Weak<Module>, NodeId),
766 /// One node in the tree of modules.
768 parent_link: ParentLink,
769 def: Cell<Option<Def>>,
772 children: RefCell<HashMap<Name, NameBindings>>,
773 imports: RefCell<Vec<ImportDirective>>,
775 // The external module children of this node that were declared with
777 external_module_children: RefCell<HashMap<Name, Rc<Module>>>,
779 // The anonymous children of this node. Anonymous children are pseudo-
780 // modules that are implicitly created around items contained within
783 // For example, if we have this:
791 // There will be an anonymous module created around `g` with the ID of the
792 // entry block for `f`.
793 anonymous_children: RefCell<NodeMap<Rc<Module>>>,
795 // The status of resolving each import in this module.
796 import_resolutions: RefCell<HashMap<Name, ImportResolution>>,
798 // The number of unresolved globs that this module exports.
799 glob_count: Cell<usize>,
801 // The number of unresolved pub imports (both regular and globs) in this module
802 pub_count: Cell<usize>,
804 // The number of unresolved pub glob imports in this module
805 pub_glob_count: Cell<usize>,
807 // The index of the import we're resolving.
808 resolved_import_count: Cell<usize>,
810 // Whether this module is populated. If not populated, any attempt to
811 // access the children must be preceded with a
812 // `populate_module_if_necessary` call.
813 populated: Cell<bool>,
817 fn new(parent_link: ParentLink,
823 parent_link: parent_link,
825 is_public: is_public,
826 children: RefCell::new(HashMap::new()),
827 imports: RefCell::new(Vec::new()),
828 external_module_children: RefCell::new(HashMap::new()),
829 anonymous_children: RefCell::new(NodeMap()),
830 import_resolutions: RefCell::new(HashMap::new()),
831 glob_count: Cell::new(0),
832 pub_count: Cell::new(0),
833 pub_glob_count: Cell::new(0),
834 resolved_import_count: Cell::new(0),
835 populated: Cell::new(!external),
839 fn def_id(&self) -> Option<DefId> {
840 self.def.get().as_ref().map(Def::def_id)
843 fn is_normal(&self) -> bool {
844 match self.def.get() {
845 Some(DefMod(_)) | Some(DefForeignMod(_)) => true,
850 fn is_trait(&self) -> bool {
851 match self.def.get() {
852 Some(DefTrait(_)) => true,
857 fn all_imports_resolved(&self) -> bool {
858 if self.imports.borrow_state() == ::std::cell::BorrowState::Writing {
859 // it is currently being resolved ! so nope
862 self.imports.borrow().len() == self.resolved_import_count.get()
868 pub fn inc_glob_count(&self) {
869 self.glob_count.set(self.glob_count.get() + 1);
871 pub fn dec_glob_count(&self) {
872 assert!(self.glob_count.get() > 0);
873 self.glob_count.set(self.glob_count.get() - 1);
875 pub fn inc_pub_count(&self) {
876 self.pub_count.set(self.pub_count.get() + 1);
878 pub fn dec_pub_count(&self) {
879 assert!(self.pub_count.get() > 0);
880 self.pub_count.set(self.pub_count.get() - 1);
882 pub fn inc_pub_glob_count(&self) {
883 self.pub_glob_count.set(self.pub_glob_count.get() + 1);
885 pub fn dec_pub_glob_count(&self) {
886 assert!(self.pub_glob_count.get() > 0);
887 self.pub_glob_count.set(self.pub_glob_count.get() - 1);
891 impl fmt::Debug for Module {
892 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
906 flags DefModifiers: u8 {
907 const PUBLIC = 1 << 0,
908 const IMPORTABLE = 1 << 1,
912 // Records a possibly-private value, type, or module definition.
915 modifiers: DefModifiers, // see note in ImportResolution about how to use this
916 def_or_module: DefOrModule,
927 fn create_from_module(module: Rc<Module>, span: Option<Span>) -> Self {
928 let modifiers = if module.is_public {
931 DefModifiers::empty()
932 } | DefModifiers::IMPORTABLE;
934 NsDef { modifiers: modifiers, def_or_module: DefOrModule::Module(module), span: span }
937 fn create_from_def(def: Def, modifiers: DefModifiers, span: Option<Span>) -> Self {
938 NsDef { modifiers: modifiers, def_or_module: DefOrModule::Def(def), span: span }
941 fn module(&self) -> Option<Rc<Module>> {
942 match self.def_or_module {
943 DefOrModule::Module(ref module) => Some(module.clone()),
944 DefOrModule::Def(_) => None,
948 fn def(&self) -> Option<Def> {
949 match self.def_or_module {
950 DefOrModule::Def(def) => Some(def),
951 DefOrModule::Module(ref module) => module.def.get(),
956 // Records at most one definition that a name in a namespace is bound to
957 #[derive(Clone,Debug)]
958 pub struct NameBinding(Rc<RefCell<Option<NsDef>>>);
962 NameBinding(Rc::new(RefCell::new(None)))
965 fn create_from_module(module: Rc<Module>) -> Self {
966 NameBinding(Rc::new(RefCell::new(Some(NsDef::create_from_module(module, None)))))
969 fn set(&self, ns_def: NsDef) {
970 *self.0.borrow_mut() = Some(ns_def);
973 fn set_modifiers(&self, modifiers: DefModifiers) {
974 if let Some(ref mut ns_def) = *self.0.borrow_mut() {
975 ns_def.modifiers = modifiers
979 fn borrow(&self) -> ::std::cell::Ref<Option<NsDef>> {
983 // Lifted versions of the NsDef methods and fields
984 fn def(&self) -> Option<Def> {
985 self.borrow().as_ref().and_then(NsDef::def)
987 fn module(&self) -> Option<Rc<Module>> {
988 self.borrow().as_ref().and_then(NsDef::module)
990 fn span(&self) -> Option<Span> {
991 self.borrow().as_ref().and_then(|def| def.span)
993 fn modifiers(&self) -> Option<DefModifiers> {
994 self.borrow().as_ref().and_then(|def| Some(def.modifiers))
997 fn defined(&self) -> bool {
998 self.borrow().is_some()
1001 fn defined_with(&self, modifiers: DefModifiers) -> bool {
1002 self.modifiers().map(|m| m.contains(modifiers)).unwrap_or(false)
1005 fn is_public(&self) -> bool {
1006 self.defined_with(DefModifiers::PUBLIC)
1009 fn def_and_lp(&self) -> (Def, LastPrivate) {
1010 let def = self.def().unwrap();
1011 (def, LastMod(if self.is_public() { AllPublic } else { DependsOn(def.def_id()) }))
1015 // Records the definitions (at most one for each namespace) that a name is
1017 #[derive(Clone,Debug)]
1018 pub struct NameBindings {
1019 type_ns: NameBinding, // < Meaning in type namespace.
1020 value_ns: NameBinding, // < Meaning in value namespace.
1023 impl ::std::ops::Index<Namespace> for NameBindings {
1024 type Output = NameBinding;
1025 fn index(&self, namespace: Namespace) -> &NameBinding {
1026 match namespace { TypeNS => &self.type_ns, ValueNS => &self.value_ns }
1031 fn new() -> NameBindings {
1033 type_ns: NameBinding::new(),
1034 value_ns: NameBinding::new(),
1038 /// Creates a new module in this set of name bindings.
1039 fn define_module(&self, module: Rc<Module>, sp: Span) {
1040 self.type_ns.set(NsDef::create_from_module(module, Some(sp)));
1043 /// Records a type definition.
1044 fn define_type(&self, def: Def, sp: Span, modifiers: DefModifiers) {
1045 debug!("defining type for def {:?} with modifiers {:?}", def, modifiers);
1046 self.type_ns.set(NsDef::create_from_def(def, modifiers, Some(sp)));
1049 /// Records a value definition.
1050 fn define_value(&self, def: Def, sp: Span, modifiers: DefModifiers) {
1051 debug!("defining value for def {:?} with modifiers {:?}", def, modifiers);
1052 self.value_ns.set(NsDef::create_from_def(def, modifiers, Some(sp)));
1056 /// Interns the names of the primitive types.
1057 struct PrimitiveTypeTable {
1058 primitive_types: HashMap<Name, PrimTy>,
1061 impl PrimitiveTypeTable {
1062 fn new() -> PrimitiveTypeTable {
1063 let mut table = PrimitiveTypeTable { primitive_types: HashMap::new() };
1065 table.intern("bool", TyBool);
1066 table.intern("char", TyChar);
1067 table.intern("f32", TyFloat(TyF32));
1068 table.intern("f64", TyFloat(TyF64));
1069 table.intern("isize", TyInt(TyIs));
1070 table.intern("i8", TyInt(TyI8));
1071 table.intern("i16", TyInt(TyI16));
1072 table.intern("i32", TyInt(TyI32));
1073 table.intern("i64", TyInt(TyI64));
1074 table.intern("str", TyStr);
1075 table.intern("usize", TyUint(TyUs));
1076 table.intern("u8", TyUint(TyU8));
1077 table.intern("u16", TyUint(TyU16));
1078 table.intern("u32", TyUint(TyU32));
1079 table.intern("u64", TyUint(TyU64));
1084 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1085 self.primitive_types.insert(token::intern(string), primitive_type);
1089 /// The main resolver class.
1090 pub struct Resolver<'a, 'tcx: 'a> {
1091 session: &'a Session,
1093 ast_map: &'a hir_map::Map<'tcx>,
1095 graph_root: Rc<Module>,
1097 trait_item_map: FnvHashMap<(Name, DefId), DefId>,
1099 structs: FnvHashMap<DefId, Vec<Name>>,
1101 // The number of imports that are currently unresolved.
1102 unresolved_imports: usize,
1104 // The module that represents the current item scope.
1105 current_module: Rc<Module>,
1107 // The current set of local scopes, for values.
1108 // FIXME #4948: Reuse ribs to avoid allocation.
1109 value_ribs: Vec<Rib>,
1111 // The current set of local scopes, for types.
1112 type_ribs: Vec<Rib>,
1114 // The current set of local scopes, for labels.
1115 label_ribs: Vec<Rib>,
1117 // The trait that the current context can refer to.
1118 current_trait_ref: Option<(DefId, TraitRef)>,
1120 // The current self type if inside an impl (used for better errors).
1121 current_self_type: Option<Ty>,
1123 // The idents for the primitive types.
1124 primitive_type_table: PrimitiveTypeTable,
1126 def_map: RefCell<DefMap>,
1127 freevars: FreevarMap,
1128 freevars_seen: NodeMap<NodeMap<usize>>,
1129 export_map: ExportMap,
1130 trait_map: TraitMap,
1131 external_exports: ExternalExports,
1133 // Whether or not to print error messages. Can be set to true
1134 // when getting additional info for error message suggestions,
1135 // so as to avoid printing duplicate errors
1138 make_glob_map: bool,
1139 // Maps imports to the names of items actually imported (this actually maps
1140 // all imports, but only glob imports are actually interesting).
1143 used_imports: HashSet<(NodeId, Namespace)>,
1144 used_crates: HashSet<CrateNum>,
1146 // Callback function for intercepting walks
1147 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>,
1148 // The intention is that the callback modifies this flag.
1149 // Once set, the resolver falls out of the walk, preserving the ribs.
1153 #[derive(PartialEq)]
1154 enum FallbackChecks {
1156 OnlyTraitAndStatics,
1159 impl<'a, 'tcx> Resolver<'a, 'tcx> {
1160 fn new(session: &'a Session,
1161 ast_map: &'a hir_map::Map<'tcx>,
1162 make_glob_map: MakeGlobMap)
1163 -> Resolver<'a, 'tcx> {
1164 let root_def_id = ast_map.local_def_id(CRATE_NODE_ID);
1165 let graph_root = Module::new(NoParentLink, Some(DefMod(root_def_id)), false, true);
1172 // The outermost module has def ID 0; this is not reflected in the
1174 graph_root: graph_root.clone(),
1176 trait_item_map: FnvHashMap(),
1177 structs: FnvHashMap(),
1179 unresolved_imports: 0,
1181 current_module: graph_root,
1182 value_ribs: Vec::new(),
1183 type_ribs: Vec::new(),
1184 label_ribs: Vec::new(),
1186 current_trait_ref: None,
1187 current_self_type: None,
1189 primitive_type_table: PrimitiveTypeTable::new(),
1191 def_map: RefCell::new(NodeMap()),
1192 freevars: NodeMap(),
1193 freevars_seen: NodeMap(),
1194 export_map: NodeMap(),
1195 trait_map: NodeMap(),
1196 used_imports: HashSet::new(),
1197 used_crates: HashSet::new(),
1198 external_exports: DefIdSet(),
1201 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1202 glob_map: HashMap::new(),
1210 fn record_import_use(&mut self, import_id: NodeId, name: Name) {
1211 if !self.make_glob_map {
1214 if self.glob_map.contains_key(&import_id) {
1215 self.glob_map.get_mut(&import_id).unwrap().insert(name);
1219 let mut new_set = HashSet::new();
1220 new_set.insert(name);
1221 self.glob_map.insert(import_id, new_set);
1224 fn get_trait_name(&self, did: DefId) -> Name {
1225 if let Some(node_id) = self.ast_map.as_local_node_id(did) {
1226 self.ast_map.expect_item(node_id).name
1228 self.session.cstore.item_name(did)
1232 /// Checks that the names of external crates don't collide with other
1233 /// external crates.
1234 fn check_for_conflicts_between_external_crates(&self,
1238 if module.external_module_children.borrow().contains_key(&name) {
1239 span_err!(self.session,
1242 "an external crate named `{}` has already been imported into this module",
1247 /// Checks that the names of items don't collide with external crates.
1248 fn check_for_conflicts_between_external_crates_and_items(&self,
1252 if module.external_module_children.borrow().contains_key(&name) {
1253 span_err!(self.session,
1256 "the name `{}` conflicts with an external crate that has been imported \
1262 /// Resolves the given module path from the given root `module_`.
1263 fn resolve_module_path_from_root(&mut self,
1264 module_: Rc<Module>,
1265 module_path: &[Name],
1268 name_search_type: NameSearchType,
1270 -> ResolveResult<(Rc<Module>, LastPrivate)> {
1271 fn search_parent_externals(needle: Name, module: &Rc<Module>) -> Option<Rc<Module>> {
1272 match module.external_module_children.borrow().get(&needle) {
1273 Some(_) => Some(module.clone()),
1274 None => match module.parent_link {
1275 ModuleParentLink(ref parent, _) => {
1276 search_parent_externals(needle, &parent.upgrade().unwrap())
1283 let mut search_module = module_;
1284 let mut index = index;
1285 let module_path_len = module_path.len();
1286 let mut closest_private = lp;
1288 // Resolve the module part of the path. This does not involve looking
1289 // upward though scope chains; we simply resolve names directly in
1290 // modules as we go.
1291 while index < module_path_len {
1292 let name = module_path[index];
1293 match self.resolve_name_in_module(search_module.clone(),
1299 let segment_name = name.as_str();
1300 let module_name = module_to_string(&*search_module);
1301 let mut span = span;
1302 let msg = if "???" == &module_name[..] {
1303 span.hi = span.lo + Pos::from_usize(segment_name.len());
1305 match search_parent_externals(name, &self.current_module) {
1307 let path_str = names_to_string(module_path);
1308 let target_mod_str = module_to_string(&*module);
1309 let current_mod_str = module_to_string(&*self.current_module);
1311 let prefix = if target_mod_str == current_mod_str {
1312 "self::".to_string()
1314 format!("{}::", target_mod_str)
1317 format!("Did you mean `{}{}`?", prefix, path_str)
1319 None => format!("Maybe a missing `extern crate {}`?", segment_name),
1322 format!("Could not find `{}` in `{}`", segment_name, module_name)
1325 return Failed(Some((span, msg)));
1327 Failed(err) => return Failed(err),
1329 debug!("(resolving module path for import) module resolution is \
1332 return Indeterminate;
1334 Success((target, used_proxy)) => {
1335 // Check to see whether there are type bindings, and, if
1336 // so, whether there is a module within.
1337 if let Some(module_def) = target.binding.module() {
1338 // track extern crates for unused_extern_crate lint
1339 if let Some(did) = module_def.def_id() {
1340 self.used_crates.insert(did.krate);
1343 search_module = module_def;
1345 // Keep track of the closest private module used
1346 // when resolving this import chain.
1347 if !used_proxy && !search_module.is_public {
1348 if let Some(did) = search_module.def_id() {
1349 closest_private = LastMod(DependsOn(did));
1353 let msg = format!("Not a module `{}`", name);
1354 return Failed(Some((span, msg)));
1362 return Success((search_module, closest_private));
1365 /// Attempts to resolve the module part of an import directive or path
1366 /// rooted at the given module.
1368 /// On success, returns the resolved module, and the closest *private*
1369 /// module found to the destination when resolving this path.
1370 fn resolve_module_path(&mut self,
1371 module_: Rc<Module>,
1372 module_path: &[Name],
1373 use_lexical_scope: UseLexicalScopeFlag,
1375 name_search_type: NameSearchType)
1376 -> ResolveResult<(Rc<Module>, LastPrivate)> {
1377 let module_path_len = module_path.len();
1378 assert!(module_path_len > 0);
1380 debug!("(resolving module path for import) processing `{}` rooted at `{}`",
1381 names_to_string(module_path),
1382 module_to_string(&*module_));
1384 // Resolve the module prefix, if any.
1385 let module_prefix_result = self.resolve_module_prefix(module_.clone(), module_path);
1390 match module_prefix_result {
1392 let mpath = names_to_string(module_path);
1393 let mpath = &mpath[..];
1394 match mpath.rfind(':') {
1396 let msg = format!("Could not find `{}` in `{}`",
1397 // idx +- 1 to account for the
1398 // colons on either side
1401 return Failed(Some((span, msg)));
1404 return Failed(None);
1408 Failed(err) => return Failed(err),
1410 debug!("(resolving module path for import) indeterminate; bailing");
1411 return Indeterminate;
1413 Success(NoPrefixFound) => {
1414 // There was no prefix, so we're considering the first element
1415 // of the path. How we handle this depends on whether we were
1416 // instructed to use lexical scope or not.
1417 match use_lexical_scope {
1418 DontUseLexicalScope => {
1419 // This is a crate-relative path. We will start the
1420 // resolution process at index zero.
1421 search_module = self.graph_root.clone();
1423 last_private = LastMod(AllPublic);
1425 UseLexicalScope => {
1426 // This is not a crate-relative path. We resolve the
1427 // first component of the path in the current lexical
1428 // scope and then proceed to resolve below that.
1429 match self.resolve_module_in_lexical_scope(module_, module_path[0]) {
1430 Failed(err) => return Failed(err),
1432 debug!("(resolving module path for import) indeterminate; bailing");
1433 return Indeterminate;
1435 Success(containing_module) => {
1436 search_module = containing_module;
1438 last_private = LastMod(AllPublic);
1444 Success(PrefixFound(ref containing_module, index)) => {
1445 search_module = containing_module.clone();
1446 start_index = index;
1447 last_private = LastMod(DependsOn(containing_module.def_id()
1452 self.resolve_module_path_from_root(search_module,
1460 /// Invariant: This must only be called during main resolution, not during
1461 /// import resolution.
1462 fn resolve_item_in_lexical_scope(&mut self,
1463 module_: Rc<Module>,
1465 namespace: Namespace)
1466 -> ResolveResult<(Target, bool)> {
1467 debug!("(resolving item in lexical scope) resolving `{}` in namespace {:?} in `{}`",
1470 module_to_string(&*module_));
1472 // The current module node is handled specially. First, check for
1473 // its immediate children.
1474 build_reduced_graph::populate_module_if_necessary(self, &module_);
1476 match module_.children.borrow().get(&name) {
1477 Some(name_bindings) if name_bindings[namespace].defined() => {
1478 debug!("top name bindings succeeded");
1479 return Success((Target::new(module_.clone(),
1480 name_bindings[namespace].clone(),
1485 // Not found; continue.
1489 // Now check for its import directives. We don't have to have resolved
1490 // all its imports in the usual way; this is because chains of
1491 // adjacent import statements are processed as though they mutated the
1493 if let Some(import_resolution) = module_.import_resolutions.borrow().get(&name) {
1494 match import_resolution[namespace].target.clone() {
1496 // Not found; continue.
1497 debug!("(resolving item in lexical scope) found import resolution, but not \
1502 debug!("(resolving item in lexical scope) using import resolution");
1503 // track used imports and extern crates as well
1504 let id = import_resolution[namespace].id;
1505 self.used_imports.insert((id, namespace));
1506 self.record_import_use(id, name);
1507 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id() {
1508 self.used_crates.insert(kid);
1510 return Success((target, false));
1515 // Search for external modules.
1516 if namespace == TypeNS {
1517 // FIXME (21114): In principle unclear `child` *has* to be lifted.
1518 let child = module_.external_module_children.borrow().get(&name).cloned();
1519 if let Some(module) = child {
1520 let name_binding = NameBinding::create_from_module(module);
1521 debug!("lower name bindings succeeded");
1522 return Success((Target::new(module_, name_binding, Shadowable::Never),
1527 // Finally, proceed up the scope chain looking for parent modules.
1528 let mut search_module = module_;
1530 // Go to the next parent.
1531 match search_module.parent_link.clone() {
1533 // No more parents. This module was unresolved.
1534 debug!("(resolving item in lexical scope) unresolved module");
1535 return Failed(None);
1537 ModuleParentLink(parent_module_node, _) => {
1538 if search_module.is_normal() {
1539 // We stop the search here.
1540 debug!("(resolving item in lexical scope) unresolved module: not \
1541 searching through module parents");
1542 return Failed(None);
1544 search_module = parent_module_node.upgrade().unwrap();
1547 BlockParentLink(ref parent_module_node, _) => {
1548 search_module = parent_module_node.upgrade().unwrap();
1552 // Resolve the name in the parent module.
1553 match self.resolve_name_in_module(search_module.clone(),
1558 Failed(Some((span, msg))) => {
1559 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
1561 Failed(None) => (), // Continue up the search chain.
1563 // We couldn't see through the higher scope because of an
1564 // unresolved import higher up. Bail.
1566 debug!("(resolving item in lexical scope) indeterminate higher scope; bailing");
1567 return Indeterminate;
1569 Success((target, used_reexport)) => {
1570 // We found the module.
1571 debug!("(resolving item in lexical scope) found name in module, done");
1572 return Success((target, used_reexport));
1578 /// Resolves a module name in the current lexical scope.
1579 fn resolve_module_in_lexical_scope(&mut self,
1580 module_: Rc<Module>,
1582 -> ResolveResult<Rc<Module>> {
1583 // If this module is an anonymous module, resolve the item in the
1584 // lexical scope. Otherwise, resolve the item from the crate root.
1585 let resolve_result = self.resolve_item_in_lexical_scope(module_, name, TypeNS);
1586 match resolve_result {
1587 Success((target, _)) => {
1588 if let Some(module_def) = target.binding.module() {
1589 return Success(module_def)
1591 debug!("!!! (resolving module in lexical scope) module \
1592 wasn't actually a module!");
1593 return Failed(None);
1597 debug!("(resolving module in lexical scope) indeterminate; bailing");
1598 return Indeterminate;
1601 debug!("(resolving module in lexical scope) failed to resolve");
1607 /// Returns the nearest normal module parent of the given module.
1608 fn get_nearest_normal_module_parent(&mut self, module_: Rc<Module>) -> Option<Rc<Module>> {
1609 let mut module_ = module_;
1611 match module_.parent_link.clone() {
1612 NoParentLink => return None,
1613 ModuleParentLink(new_module, _) |
1614 BlockParentLink(new_module, _) => {
1615 let new_module = new_module.upgrade().unwrap();
1616 if new_module.is_normal() {
1617 return Some(new_module);
1619 module_ = new_module;
1625 /// Returns the nearest normal module parent of the given module, or the
1626 /// module itself if it is a normal module.
1627 fn get_nearest_normal_module_parent_or_self(&mut self, module_: Rc<Module>) -> Rc<Module> {
1628 if module_.is_normal() {
1631 match self.get_nearest_normal_module_parent(module_.clone()) {
1633 Some(new_module) => new_module,
1637 /// Resolves a "module prefix". A module prefix is one or both of (a) `self::`;
1638 /// (b) some chain of `super::`.
1639 /// grammar: (SELF MOD_SEP ) ? (SUPER MOD_SEP) *
1640 fn resolve_module_prefix(&mut self,
1641 module_: Rc<Module>,
1642 module_path: &[Name])
1643 -> ResolveResult<ModulePrefixResult> {
1644 // Start at the current module if we see `self` or `super`, or at the
1645 // top of the crate otherwise.
1646 let mut i = match &*module_path[0].as_str() {
1649 _ => return Success(NoPrefixFound),
1651 let mut containing_module = self.get_nearest_normal_module_parent_or_self(module_);
1653 // Now loop through all the `super`s we find.
1654 while i < module_path.len() && "super" == module_path[i].as_str() {
1655 debug!("(resolving module prefix) resolving `super` at {}",
1656 module_to_string(&*containing_module));
1657 match self.get_nearest_normal_module_parent(containing_module) {
1658 None => return Failed(None),
1659 Some(new_module) => {
1660 containing_module = new_module;
1666 debug!("(resolving module prefix) finished resolving prefix at {}",
1667 module_to_string(&*containing_module));
1669 return Success(PrefixFound(containing_module, i));
1672 /// Attempts to resolve the supplied name in the given module for the
1673 /// given namespace. If successful, returns the target corresponding to
1676 /// The boolean returned on success is an indicator of whether this lookup
1677 /// passed through a public re-export proxy.
1678 fn resolve_name_in_module(&mut self,
1679 module_: Rc<Module>,
1681 namespace: Namespace,
1682 name_search_type: NameSearchType,
1683 allow_private_imports: bool)
1684 -> ResolveResult<(Target, bool)> {
1685 debug!("(resolving name in module) resolving `{}` in `{}`",
1687 module_to_string(&*module_));
1689 // First, check the direct children of the module.
1690 build_reduced_graph::populate_module_if_necessary(self, &module_);
1692 match module_.children.borrow().get(&name) {
1693 Some(name_bindings) if name_bindings[namespace].defined() => {
1694 debug!("(resolving name in module) found node as child");
1695 return Success((Target::new(module_.clone(),
1696 name_bindings[namespace].clone(),
1705 // Next, check the module's imports if necessary.
1707 // If this is a search of all imports, we should be done with glob
1708 // resolution at this point.
1709 if name_search_type == PathSearch {
1710 assert_eq!(module_.glob_count.get(), 0);
1713 // Check the list of resolved imports.
1714 match module_.import_resolutions.borrow().get(&name) {
1715 Some(import_resolution) if allow_private_imports ||
1716 import_resolution[namespace].is_public => {
1718 if import_resolution[namespace].is_public &&
1719 import_resolution.outstanding_references != 0 {
1720 debug!("(resolving name in module) import unresolved; bailing out");
1721 return Indeterminate;
1723 match import_resolution[namespace].target.clone() {
1725 debug!("(resolving name in module) name found, but not in namespace {:?}",
1729 debug!("(resolving name in module) resolved to import");
1730 // track used imports and extern crates as well
1731 let id = import_resolution[namespace].id;
1732 self.used_imports.insert((id, namespace));
1733 self.record_import_use(id, name);
1734 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id() {
1735 self.used_crates.insert(kid);
1737 return Success((target, true));
1741 Some(..) | None => {} // Continue.
1744 // Finally, search through external children.
1745 if namespace == TypeNS {
1746 // FIXME (21114): In principle unclear `child` *has* to be lifted.
1747 let child = module_.external_module_children.borrow().get(&name).cloned();
1748 if let Some(module) = child {
1749 let name_binding = NameBinding::create_from_module(module);
1750 return Success((Target::new(module_, name_binding, Shadowable::Never),
1755 // We're out of luck.
1756 debug!("(resolving name in module) failed to resolve `{}`", name);
1757 return Failed(None);
1760 fn report_unresolved_imports(&mut self, module_: Rc<Module>) {
1761 let index = module_.resolved_import_count.get();
1762 let imports = module_.imports.borrow();
1763 let import_count = imports.len();
1764 if index != import_count {
1766 (*imports)[index].span,
1767 ResolutionError::UnresolvedImport(None));
1770 // Descend into children and anonymous children.
1771 build_reduced_graph::populate_module_if_necessary(self, &module_);
1773 for (_, child_node) in module_.children.borrow().iter() {
1774 match child_node.type_ns.module() {
1778 Some(child_module) => {
1779 self.report_unresolved_imports(child_module);
1784 for (_, module_) in module_.anonymous_children.borrow().iter() {
1785 self.report_unresolved_imports(module_.clone());
1791 // We maintain a list of value ribs and type ribs.
1793 // Simultaneously, we keep track of the current position in the module
1794 // graph in the `current_module` pointer. When we go to resolve a name in
1795 // the value or type namespaces, we first look through all the ribs and
1796 // then query the module graph. When we resolve a name in the module
1797 // namespace, we can skip all the ribs (since nested modules are not
1798 // allowed within blocks in Rust) and jump straight to the current module
1801 // Named implementations are handled separately. When we find a method
1802 // call, we consult the module node to find all of the implementations in
1803 // scope. This information is lazily cached in the module node. We then
1804 // generate a fake "implementation scope" containing all the
1805 // implementations thus found, for compatibility with old resolve pass.
1807 fn with_scope<F>(&mut self, name: Option<Name>, f: F)
1808 where F: FnOnce(&mut Resolver)
1810 let orig_module = self.current_module.clone();
1812 // Move down in the graph.
1818 build_reduced_graph::populate_module_if_necessary(self, &orig_module);
1820 match orig_module.children.borrow().get(&name) {
1822 debug!("!!! (with scope) didn't find `{}` in `{}`",
1824 module_to_string(&*orig_module));
1826 Some(name_bindings) => {
1827 match name_bindings.type_ns.module() {
1829 debug!("!!! (with scope) didn't find module for `{}` in `{}`",
1831 module_to_string(&*orig_module));
1834 self.current_module = module_;
1844 self.current_module = orig_module;
1847 /// Searches the current set of local scopes for labels.
1848 /// Stops after meeting a closure.
1849 fn search_label(&self, name: Name) -> Option<DefLike> {
1850 for rib in self.label_ribs.iter().rev() {
1856 // Do not resolve labels across function boundary
1860 let result = rib.bindings.get(&name).cloned();
1861 if result.is_some() {
1868 fn resolve_crate(&mut self, krate: &hir::Crate) {
1869 debug!("(resolving crate) starting");
1871 intravisit::walk_crate(self, krate);
1874 fn check_if_primitive_type_name(&self, name: Name, span: Span) {
1875 if let Some(_) = self.primitive_type_table.primitive_types.get(&name) {
1876 span_err!(self.session,
1879 "user-defined types or type parameters cannot shadow the primitive types");
1883 fn resolve_item(&mut self, item: &Item) {
1884 let name = item.name;
1886 debug!("(resolving item) resolving {}", name);
1889 ItemEnum(_, ref generics) |
1890 ItemTy(_, ref generics) |
1891 ItemStruct(_, ref generics) => {
1892 self.check_if_primitive_type_name(name, item.span);
1894 self.with_type_parameter_rib(HasTypeParameters(generics, TypeSpace, ItemRibKind),
1895 |this| intravisit::walk_item(this, item));
1897 ItemFn(_, _, _, _, ref generics, _) => {
1898 self.with_type_parameter_rib(HasTypeParameters(generics, FnSpace, ItemRibKind),
1899 |this| intravisit::walk_item(this, item));
1902 ItemDefaultImpl(_, ref trait_ref) => {
1903 self.with_optional_trait_ref(Some(trait_ref), |_, _| {});
1905 ItemImpl(_, _, ref generics, ref opt_trait_ref, ref self_type, ref impl_items) => {
1906 self.resolve_implementation(generics,
1913 ItemTrait(_, ref generics, ref bounds, ref trait_items) => {
1914 self.check_if_primitive_type_name(name, item.span);
1916 // Create a new rib for the trait-wide type parameters.
1917 self.with_type_parameter_rib(HasTypeParameters(generics,
1921 let local_def_id = this.ast_map.local_def_id(item.id);
1922 this.with_self_rib(DefSelfTy(Some(local_def_id), None), |this| {
1923 this.visit_generics(generics);
1924 walk_list!(this, visit_ty_param_bound, bounds);
1926 for trait_item in trait_items {
1927 match trait_item.node {
1928 hir::ConstTraitItem(_, ref default) => {
1929 // Only impose the restrictions of
1930 // ConstRibKind if there's an actual constant
1931 // expression in a provided default.
1932 if default.is_some() {
1933 this.with_constant_rib(|this| {
1934 intravisit::walk_trait_item(this, trait_item)
1937 intravisit::walk_trait_item(this, trait_item)
1940 hir::MethodTraitItem(ref sig, _) => {
1941 let type_parameters =
1942 HasTypeParameters(&sig.generics,
1945 this.with_type_parameter_rib(type_parameters, |this| {
1946 intravisit::walk_trait_item(this, trait_item)
1949 hir::TypeTraitItem(..) => {
1950 this.check_if_primitive_type_name(trait_item.name,
1952 this.with_type_parameter_rib(NoTypeParameters, |this| {
1953 intravisit::walk_trait_item(this, trait_item)
1962 ItemMod(_) | ItemForeignMod(_) => {
1963 self.with_scope(Some(name), |this| {
1964 intravisit::walk_item(this, item);
1968 ItemConst(..) | ItemStatic(..) => {
1969 self.with_constant_rib(|this| {
1970 intravisit::walk_item(this, item);
1974 ItemUse(ref view_path) => {
1975 // check for imports shadowing primitive types
1976 let check_rename = |this: &Self, id, name| {
1977 match this.def_map.borrow().get(&id).map(|d| d.full_def()) {
1978 Some(DefTy(..)) | Some(DefStruct(..)) | Some(DefTrait(..)) | None => {
1979 this.check_if_primitive_type_name(name, item.span);
1985 match view_path.node {
1986 hir::ViewPathSimple(name, _) => {
1987 check_rename(self, item.id, name);
1989 hir::ViewPathList(ref prefix, ref items) => {
1991 if let Some(name) = item.node.rename() {
1992 check_rename(self, item.node.id(), name);
1996 // Resolve prefix of an import with empty braces (issue #28388)
1997 if items.is_empty() && !prefix.segments.is_empty() {
1998 match self.resolve_crate_relative_path(prefix.span,
2002 self.record_def(item.id, PathResolution::new(def, lp, 0)),
2006 ResolutionError::FailedToResolve(
2007 &path_names_to_string(prefix, 0)));
2016 ItemExternCrate(_) => {
2017 // do nothing, these are just around to be encoded
2022 fn with_type_parameter_rib<F>(&mut self, type_parameters: TypeParameters, f: F)
2023 where F: FnOnce(&mut Resolver)
2025 match type_parameters {
2026 HasTypeParameters(generics, space, rib_kind) => {
2027 let mut function_type_rib = Rib::new(rib_kind);
2028 let mut seen_bindings = HashSet::new();
2029 for (index, type_parameter) in generics.ty_params.iter().enumerate() {
2030 let name = type_parameter.name;
2031 debug!("with_type_parameter_rib: {}", type_parameter.id);
2033 if seen_bindings.contains(&name) {
2035 type_parameter.span,
2036 ResolutionError::NameAlreadyUsedInTypeParameterList(name));
2038 seen_bindings.insert(name);
2040 // plain insert (no renaming)
2041 function_type_rib.bindings
2043 DlDef(DefTyParam(space,
2046 .local_def_id(type_parameter.id),
2049 self.type_ribs.push(function_type_rib);
2052 NoTypeParameters => {
2059 match type_parameters {
2060 HasTypeParameters(..) => {
2062 self.type_ribs.pop();
2065 NoTypeParameters => {}
2069 fn with_label_rib<F>(&mut self, f: F)
2070 where F: FnOnce(&mut Resolver)
2072 self.label_ribs.push(Rib::new(NormalRibKind));
2075 self.label_ribs.pop();
2079 fn with_constant_rib<F>(&mut self, f: F)
2080 where F: FnOnce(&mut Resolver)
2082 self.value_ribs.push(Rib::new(ConstantItemRibKind));
2083 self.type_ribs.push(Rib::new(ConstantItemRibKind));
2086 self.type_ribs.pop();
2087 self.value_ribs.pop();
2091 fn resolve_function(&mut self, rib_kind: RibKind, declaration: &FnDecl, block: &Block) {
2092 // Create a value rib for the function.
2093 self.value_ribs.push(Rib::new(rib_kind));
2095 // Create a label rib for the function.
2096 self.label_ribs.push(Rib::new(rib_kind));
2098 // Add each argument to the rib.
2099 let mut bindings_list = HashMap::new();
2100 for argument in &declaration.inputs {
2101 self.resolve_pattern(&*argument.pat, ArgumentIrrefutableMode, &mut bindings_list);
2103 self.visit_ty(&*argument.ty);
2105 debug!("(resolving function) recorded argument");
2107 intravisit::walk_fn_ret_ty(self, &declaration.output);
2109 // Resolve the function body.
2110 self.visit_block(block);
2112 debug!("(resolving function) leaving function");
2115 self.label_ribs.pop();
2116 self.value_ribs.pop();
2120 fn resolve_trait_reference(&mut self,
2124 -> Result<PathResolution, ()> {
2125 if let Some(path_res) = self.resolve_path(id, trait_path, path_depth, TypeNS, true) {
2126 if let DefTrait(_) = path_res.base_def {
2127 debug!("(resolving trait) found trait def: {:?}", path_res);
2132 ResolutionError::IsNotATrait(&*path_names_to_string(trait_path,
2135 // If it's a typedef, give a note
2136 if let DefTy(..) = path_res.base_def {
2138 .span_note(trait_path.span, "`type` aliases cannot be used for traits");
2145 ResolutionError::UndeclaredTraitName(&*path_names_to_string(trait_path,
2151 fn resolve_generics(&mut self, generics: &Generics) {
2152 for type_parameter in generics.ty_params.iter() {
2153 self.check_if_primitive_type_name(type_parameter.name, type_parameter.span);
2155 for predicate in &generics.where_clause.predicates {
2157 &hir::WherePredicate::BoundPredicate(_) |
2158 &hir::WherePredicate::RegionPredicate(_) => {}
2159 &hir::WherePredicate::EqPredicate(ref eq_pred) => {
2160 let path_res = self.resolve_path(eq_pred.id, &eq_pred.path, 0, TypeNS, true);
2161 if let Some(PathResolution { base_def: DefTyParam(..), .. }) = path_res {
2162 self.record_def(eq_pred.id, path_res.unwrap());
2166 ResolutionError::UndeclaredAssociatedType);
2171 intravisit::walk_generics(self, generics);
2174 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2175 where F: FnOnce(&mut Resolver) -> T
2177 // Handle nested impls (inside fn bodies)
2178 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2179 let result = f(self);
2180 self.current_self_type = previous_value;
2184 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
2185 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2187 let mut new_val = None;
2188 let mut new_id = None;
2189 if let Some(trait_ref) = opt_trait_ref {
2190 if let Ok(path_res) = self.resolve_trait_reference(trait_ref.ref_id,
2193 assert!(path_res.depth == 0);
2194 self.record_def(trait_ref.ref_id, path_res);
2195 new_val = Some((path_res.base_def.def_id(), trait_ref.clone()));
2196 new_id = Some(path_res.base_def.def_id());
2198 intravisit::walk_trait_ref(self, trait_ref);
2200 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2201 let result = f(self, new_id);
2202 self.current_trait_ref = original_trait_ref;
2206 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2207 where F: FnOnce(&mut Resolver)
2209 let mut self_type_rib = Rib::new(NormalRibKind);
2211 // plain insert (no renaming, types are not currently hygienic....)
2212 let name = special_names::type_self;
2213 self_type_rib.bindings.insert(name, DlDef(self_def));
2214 self.type_ribs.push(self_type_rib);
2217 self.type_ribs.pop();
2221 fn resolve_implementation(&mut self,
2222 generics: &Generics,
2223 opt_trait_reference: &Option<TraitRef>,
2226 impl_items: &[ImplItem]) {
2227 // If applicable, create a rib for the type parameters.
2228 self.with_type_parameter_rib(HasTypeParameters(generics,
2232 // Resolve the type parameters.
2233 this.visit_generics(generics);
2235 // Resolve the trait reference, if necessary.
2236 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2237 // Resolve the self type.
2238 this.visit_ty(self_type);
2240 this.with_self_rib(DefSelfTy(trait_id, Some((item_id, self_type.id))), |this| {
2241 this.with_current_self_type(self_type, |this| {
2242 for impl_item in impl_items {
2243 match impl_item.node {
2244 hir::ImplItemKind::Const(..) => {
2245 // If this is a trait impl, ensure the const
2247 this.check_trait_item(impl_item.name,
2249 |n, s| ResolutionError::ConstNotMemberOfTrait(n, s));
2250 this.with_constant_rib(|this| {
2251 intravisit::walk_impl_item(this, impl_item);
2254 hir::ImplItemKind::Method(ref sig, _) => {
2255 // If this is a trait impl, ensure the method
2257 this.check_trait_item(impl_item.name,
2259 |n, s| ResolutionError::MethodNotMemberOfTrait(n, s));
2261 // We also need a new scope for the method-
2262 // specific type parameters.
2263 let type_parameters =
2264 HasTypeParameters(&sig.generics,
2267 this.with_type_parameter_rib(type_parameters, |this| {
2268 intravisit::walk_impl_item(this, impl_item);
2271 hir::ImplItemKind::Type(ref ty) => {
2272 // If this is a trait impl, ensure the type
2274 this.check_trait_item(impl_item.name,
2276 |n, s| ResolutionError::TypeNotMemberOfTrait(n, s));
2288 fn check_trait_item<F>(&self, name: Name, span: Span, err: F)
2289 where F: FnOnce(Name, &str) -> ResolutionError
2291 // If there is a TraitRef in scope for an impl, then the method must be in the
2293 if let Some((did, ref trait_ref)) = self.current_trait_ref {
2294 if !self.trait_item_map.contains_key(&(name, did)) {
2295 let path_str = path_names_to_string(&trait_ref.path, 0);
2296 resolve_error(self, span, err(name, &*path_str));
2301 fn resolve_local(&mut self, local: &Local) {
2302 // Resolve the type.
2303 walk_list!(self, visit_ty, &local.ty);
2305 // Resolve the initializer.
2306 walk_list!(self, visit_expr, &local.init);
2308 // Resolve the pattern.
2309 self.resolve_pattern(&*local.pat, LocalIrrefutableMode, &mut HashMap::new());
2312 // build a map from pattern identifiers to binding-info's.
2313 // this is done hygienically. This could arise for a macro
2314 // that expands into an or-pattern where one 'x' was from the
2315 // user and one 'x' came from the macro.
2316 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2317 let mut result = HashMap::new();
2318 pat_bindings(&self.def_map, pat, |binding_mode, _id, sp, path1| {
2319 let name = path1.node;
2323 binding_mode: binding_mode,
2329 // check that all of the arms in an or-pattern have exactly the
2330 // same set of bindings, with the same binding modes for each.
2331 fn check_consistent_bindings(&mut self, arm: &Arm) {
2332 if arm.pats.is_empty() {
2335 let map_0 = self.binding_mode_map(&*arm.pats[0]);
2336 for (i, p) in arm.pats.iter().enumerate() {
2337 let map_i = self.binding_mode_map(&**p);
2339 for (&key, &binding_0) in &map_0 {
2340 match map_i.get(&key) {
2344 ResolutionError::VariableNotBoundInPattern(key, i + 1));
2346 Some(binding_i) => {
2347 if binding_0.binding_mode != binding_i.binding_mode {
2350 ResolutionError::VariableBoundWithDifferentMode(key,
2357 for (&key, &binding) in &map_i {
2358 if !map_0.contains_key(&key) {
2361 ResolutionError::VariableNotBoundInParentPattern(key, i + 1));
2367 fn resolve_arm(&mut self, arm: &Arm) {
2368 self.value_ribs.push(Rib::new(NormalRibKind));
2370 let mut bindings_list = HashMap::new();
2371 for pattern in &arm.pats {
2372 self.resolve_pattern(&**pattern, RefutableMode, &mut bindings_list);
2375 // This has to happen *after* we determine which
2376 // pat_idents are variants
2377 self.check_consistent_bindings(arm);
2379 walk_list!(self, visit_expr, &arm.guard);
2380 self.visit_expr(&*arm.body);
2383 self.value_ribs.pop();
2387 fn resolve_block(&mut self, block: &Block) {
2388 debug!("(resolving block) entering block");
2389 self.value_ribs.push(Rib::new(NormalRibKind));
2391 // Move down in the graph, if there's an anonymous module rooted here.
2392 let orig_module = self.current_module.clone();
2393 match orig_module.anonymous_children.borrow().get(&block.id) {
2397 Some(anonymous_module) => {
2398 debug!("(resolving block) found anonymous module, moving down");
2399 self.current_module = anonymous_module.clone();
2403 // Check for imports appearing after non-item statements.
2404 let mut found_non_item = false;
2405 for statement in &block.stmts {
2406 if let hir::StmtDecl(ref declaration, _) = statement.node {
2407 if let hir::DeclItem(i) = declaration.node {
2408 let i = self.ast_map.expect_item(i.id);
2410 ItemExternCrate(_) | ItemUse(_) if found_non_item => {
2411 span_err!(self.session,
2414 "imports are not allowed after non-item statements");
2419 found_non_item = true
2422 found_non_item = true;
2426 // Descend into the block.
2427 intravisit::walk_block(self, block);
2431 self.current_module = orig_module;
2432 self.value_ribs.pop();
2434 debug!("(resolving block) leaving block");
2437 fn resolve_type(&mut self, ty: &Ty) {
2439 TyPath(ref maybe_qself, ref path) => {
2440 let resolution = match self.resolve_possibly_assoc_item(ty.id,
2441 maybe_qself.as_ref(),
2445 // `<T>::a::b::c` is resolved by typeck alone.
2446 TypecheckRequired => {
2447 // Resolve embedded types.
2448 intravisit::walk_ty(self, ty);
2451 ResolveAttempt(resolution) => resolution,
2454 // This is a path in the type namespace. Walk through scopes
2458 // Write the result into the def map.
2459 debug!("(resolving type) writing resolution for `{}` (id {}) = {:?}",
2460 path_names_to_string(path, 0),
2463 self.record_def(ty.id, def);
2466 // Keep reporting some errors even if they're ignored above.
2467 self.resolve_path(ty.id, path, 0, TypeNS, true);
2469 let kind = if maybe_qself.is_some() {
2475 let self_type_name = special_idents::type_self.name;
2476 let is_invalid_self_type_name = path.segments.len() > 0 &&
2477 maybe_qself.is_none() &&
2478 path.segments[0].identifier.name ==
2480 if is_invalid_self_type_name {
2483 ResolutionError::SelfUsedOutsideImplOrTrait);
2487 ResolutionError::UseOfUndeclared(
2489 &*path_names_to_string(path,
2498 // Resolve embedded types.
2499 intravisit::walk_ty(self, ty);
2502 fn resolve_pattern(&mut self,
2504 mode: PatternBindingMode,
2505 // Maps idents to the node ID for the (outermost)
2506 // pattern that binds them
2507 bindings_list: &mut HashMap<Name, NodeId>) {
2508 let pat_id = pattern.id;
2509 walk_pat(pattern, |pattern| {
2510 match pattern.node {
2511 PatIdent(binding_mode, ref path1, ref at_rhs) => {
2512 // The meaning of PatIdent with no type parameters
2513 // depends on whether an enum variant or unit-like struct
2514 // with that name is in scope. The probing lookup has to
2515 // be careful not to emit spurious errors. Only matching
2516 // patterns (match) can match nullary variants or
2517 // unit-like structs. For binding patterns (let
2518 // and the LHS of @-patterns), matching such a value is
2519 // simply disallowed (since it's rarely what you want).
2520 let const_ok = mode == RefutableMode && at_rhs.is_none();
2522 let ident = path1.node;
2523 let renamed = ident.name;
2525 match self.resolve_bare_identifier_pattern(ident.unhygienic_name,
2527 FoundStructOrEnumVariant(def, lp) if const_ok => {
2528 debug!("(resolving pattern) resolving `{}` to struct or enum variant",
2531 self.enforce_default_binding_mode(pattern,
2534 self.record_def(pattern.id,
2541 FoundStructOrEnumVariant(..) => {
2545 ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(
2549 FoundConst(def, lp, _) if const_ok => {
2550 debug!("(resolving pattern) resolving `{}` to constant", renamed);
2552 self.enforce_default_binding_mode(pattern, binding_mode, "a constant");
2553 self.record_def(pattern.id,
2560 FoundConst(def, _, name) => {
2564 ResolutionError::OnlyIrrefutablePatternsAllowedHere(def.def_id(),
2568 BareIdentifierPatternUnresolved => {
2569 debug!("(resolving pattern) binding `{}`", renamed);
2571 let def_id = self.ast_map.local_def_id(pattern.id);
2572 let def = DefLocal(def_id, pattern.id);
2574 // Record the definition so that later passes
2575 // will be able to distinguish variants from
2576 // locals in patterns.
2578 self.record_def(pattern.id,
2581 last_private: LastMod(AllPublic),
2585 // Add the binding to the local ribs, if it
2586 // doesn't already exist in the bindings list. (We
2587 // must not add it if it's in the bindings list
2588 // because that breaks the assumptions later
2589 // passes make about or-patterns.)
2590 if !bindings_list.contains_key(&renamed) {
2591 let this = &mut *self;
2592 let last_rib = this.value_ribs.last_mut().unwrap();
2593 last_rib.bindings.insert(renamed, DlDef(def));
2594 bindings_list.insert(renamed, pat_id);
2595 } else if mode == ArgumentIrrefutableMode &&
2596 bindings_list.contains_key(&renamed) {
2597 // Forbid duplicate bindings in the same
2602 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2603 &ident.name.as_str())
2605 } else if bindings_list.get(&renamed) == Some(&pat_id) {
2606 // Then this is a duplicate variable in the
2607 // same disjunction, which is an error.
2611 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2612 &ident.name.as_str())
2615 // Else, not bound in the same pattern: do
2621 PatEnum(ref path, _) => {
2622 // This must be an enum variant, struct or const.
2623 let resolution = match self.resolve_possibly_assoc_item(pat_id,
2628 // The below shouldn't happen because all
2629 // qualified paths should be in PatQPath.
2630 TypecheckRequired =>
2631 self.session.span_bug(path.span,
2632 "resolve_possibly_assoc_item claimed
2634 that a path in PatEnum requires typecheck
2636 to resolve, but qualified paths should be
2639 ResolveAttempt(resolution) => resolution,
2641 if let Some(path_res) = resolution {
2642 match path_res.base_def {
2643 DefVariant(..) | DefStruct(..) | DefConst(..) => {
2644 self.record_def(pattern.id, path_res);
2647 resolve_error(&self,
2649 ResolutionError::StaticVariableReference);
2652 // If anything ends up here entirely resolved,
2653 // it's an error. If anything ends up here
2654 // partially resolved, that's OK, because it may
2655 // be a `T::CONST` that typeck will resolve.
2656 if path_res.depth == 0 {
2660 ResolutionError::NotAnEnumVariantStructOrConst(
2669 let const_name = path.segments
2674 let traits = self.get_traits_containing_item(const_name);
2675 self.trait_map.insert(pattern.id, traits);
2676 self.record_def(pattern.id, path_res);
2684 ResolutionError::UnresolvedEnumVariantStructOrConst(
2685 &path.segments.last().unwrap().identifier.name.as_str())
2688 intravisit::walk_path(self, path);
2691 PatQPath(ref qself, ref path) => {
2692 // Associated constants only.
2693 let resolution = match self.resolve_possibly_assoc_item(pat_id,
2698 TypecheckRequired => {
2699 // All `<T>::CONST` should end up here, and will
2700 // require use of the trait map to resolve
2701 // during typechecking.
2702 let const_name = path.segments
2707 let traits = self.get_traits_containing_item(const_name);
2708 self.trait_map.insert(pattern.id, traits);
2709 intravisit::walk_pat(self, pattern);
2712 ResolveAttempt(resolution) => resolution,
2714 if let Some(path_res) = resolution {
2715 match path_res.base_def {
2716 // All `<T as Trait>::CONST` should end up here, and
2717 // have the trait already selected.
2718 DefAssociatedConst(..) => {
2719 self.record_def(pattern.id, path_res);
2725 ResolutionError::NotAnAssociatedConst(
2726 &path.segments.last().unwrap().identifier.name.as_str()
2734 ResolutionError::UnresolvedAssociatedConst(&path.segments
2741 intravisit::walk_pat(self, pattern);
2744 PatStruct(ref path, _, _) => {
2745 match self.resolve_path(pat_id, path, 0, TypeNS, false) {
2746 Some(definition) => {
2747 self.record_def(pattern.id, definition);
2750 debug!("(resolving pattern) didn't find struct def: {:?}", result);
2754 ResolutionError::DoesNotNameAStruct(
2755 &*path_names_to_string(path, 0))
2759 intravisit::walk_path(self, path);
2762 PatLit(_) | PatRange(..) => {
2763 intravisit::walk_pat(self, pattern);
2774 fn resolve_bare_identifier_pattern(&mut self,
2777 -> BareIdentifierPatternResolution {
2778 let module = self.current_module.clone();
2779 match self.resolve_item_in_lexical_scope(module, name, ValueNS) {
2780 Success((target, _)) => {
2781 debug!("(resolve bare identifier pattern) succeeded in finding {} at {:?}",
2783 target.binding.borrow());
2784 match target.binding.def() {
2786 panic!("resolved name in the value namespace to a set of name bindings \
2789 // For the two success cases, this lookup can be
2790 // considered as not having a private component because
2791 // the lookup happened only within the current module.
2792 Some(def @ DefVariant(..)) | Some(def @ DefStruct(..)) => {
2793 return FoundStructOrEnumVariant(def, LastMod(AllPublic));
2795 Some(def @ DefConst(..)) | Some(def @ DefAssociatedConst(..)) => {
2796 return FoundConst(def, LastMod(AllPublic), name);
2798 Some(DefStatic(..)) => {
2799 resolve_error(self, span, ResolutionError::StaticVariableReference);
2800 return BareIdentifierPatternUnresolved;
2802 _ => return BareIdentifierPatternUnresolved
2807 panic!("unexpected indeterminate result");
2811 Some((span, msg)) => {
2812 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
2817 debug!("(resolve bare identifier pattern) failed to find {}", name);
2818 return BareIdentifierPatternUnresolved;
2823 /// Handles paths that may refer to associated items
2824 fn resolve_possibly_assoc_item(&mut self,
2826 maybe_qself: Option<&hir::QSelf>,
2828 namespace: Namespace,
2830 -> AssocItemResolveResult {
2831 let max_assoc_types;
2835 if qself.position == 0 {
2836 return TypecheckRequired;
2838 max_assoc_types = path.segments.len() - qself.position;
2839 // Make sure the trait is valid.
2840 let _ = self.resolve_trait_reference(id, path, max_assoc_types);
2843 max_assoc_types = path.segments.len();
2847 let mut resolution = self.with_no_errors(|this| {
2848 this.resolve_path(id, path, 0, namespace, check_ribs)
2850 for depth in 1..max_assoc_types {
2851 if resolution.is_some() {
2854 self.with_no_errors(|this| {
2855 resolution = this.resolve_path(id, path, depth, TypeNS, true);
2858 if let Some(DefMod(_)) = resolution.map(|r| r.base_def) {
2859 // A module is not a valid type or value.
2862 ResolveAttempt(resolution)
2865 /// If `check_ribs` is true, checks the local definitions first; i.e.
2866 /// doesn't skip straight to the containing module.
2867 /// Skips `path_depth` trailing segments, which is also reflected in the
2868 /// returned value. See `middle::def::PathResolution` for more info.
2869 pub fn resolve_path(&mut self,
2873 namespace: Namespace,
2875 -> Option<PathResolution> {
2876 let span = path.span;
2877 let segments = &path.segments[..path.segments.len() - path_depth];
2879 let mk_res = |(def, lp)| PathResolution::new(def, lp, path_depth);
2882 let def = self.resolve_crate_relative_path(span, segments, namespace);
2883 return def.map(mk_res);
2886 // Try to find a path to an item in a module.
2887 let unqualified_def = self.resolve_identifier(segments.last().unwrap().identifier,
2891 if segments.len() <= 1 {
2892 return unqualified_def.and_then(|def| self.adjust_local_def(def, span))
2894 PathResolution::new(def, LastMod(AllPublic), path_depth)
2898 let def = self.resolve_module_relative_path(span, segments, namespace);
2899 match (def, unqualified_def) {
2900 (Some((ref d, _)), Some(ref ud)) if *d == ud.def => {
2902 .add_lint(lint::builtin::UNUSED_QUALIFICATIONS,
2905 "unnecessary qualification".to_string());
2913 // Resolve a single identifier
2914 fn resolve_identifier(&mut self,
2915 identifier: hir::Ident,
2916 namespace: Namespace,
2918 -> Option<LocalDef> {
2919 // First, check to see whether the name is a primitive type.
2920 if namespace == TypeNS {
2921 if let Some(&prim_ty) = self.primitive_type_table
2923 .get(&identifier.unhygienic_name) {
2924 return Some(LocalDef::from_def(DefPrimTy(prim_ty)));
2929 if let Some(def) = self.resolve_identifier_in_local_ribs(identifier, namespace) {
2934 self.resolve_item_by_name_in_lexical_scope(identifier.unhygienic_name, namespace)
2935 .map(LocalDef::from_def)
2938 // Resolve a local definition, potentially adjusting for closures.
2939 fn adjust_local_def(&mut self, local_def: LocalDef, span: Span) -> Option<Def> {
2940 let ribs = match local_def.ribs {
2941 Some((TypeNS, i)) => &self.type_ribs[i + 1..],
2942 Some((ValueNS, i)) => &self.value_ribs[i + 1..],
2945 let mut def = local_def.def;
2948 self.session.span_bug(span, &format!("unexpected {:?} in bindings", def))
2950 DefLocal(_, node_id) => {
2954 // Nothing to do. Continue.
2956 ClosureRibKind(function_id) => {
2958 let node_def_id = self.ast_map.local_def_id(node_id);
2960 let seen = self.freevars_seen
2962 .or_insert_with(|| NodeMap());
2963 if let Some(&index) = seen.get(&node_id) {
2964 def = DefUpvar(node_def_id, node_id, index, function_id);
2967 let vec = self.freevars
2969 .or_insert_with(|| vec![]);
2970 let depth = vec.len();
2976 def = DefUpvar(node_def_id, node_id, depth, function_id);
2977 seen.insert(node_id, depth);
2979 ItemRibKind | MethodRibKind => {
2980 // This was an attempt to access an upvar inside a
2981 // named function item. This is not allowed, so we
2985 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
2988 ConstantItemRibKind => {
2989 // Still doesn't deal with upvars
2992 ResolutionError::AttemptToUseNonConstantValueInConstant);
2998 DefTyParam(..) | DefSelfTy(..) => {
3001 NormalRibKind | MethodRibKind | ClosureRibKind(..) => {
3002 // Nothing to do. Continue.
3005 // This was an attempt to use a type parameter outside
3010 ResolutionError::TypeParametersFromOuterFunction);
3013 ConstantItemRibKind => {
3015 resolve_error(self, span, ResolutionError::OuterTypeParameterContext);
3026 // resolve a "module-relative" path, e.g. a::b::c
3027 fn resolve_module_relative_path(&mut self,
3029 segments: &[hir::PathSegment],
3030 namespace: Namespace)
3031 -> Option<(Def, LastPrivate)> {
3032 let module_path = segments.split_last()
3036 .map(|ps| ps.identifier.name)
3037 .collect::<Vec<_>>();
3039 let containing_module;
3041 let current_module = self.current_module.clone();
3042 match self.resolve_module_path(current_module,
3048 let (span, msg) = match err {
3049 Some((span, msg)) => (span, msg),
3051 let msg = format!("Use of undeclared type or module `{}`",
3052 names_to_string(&module_path));
3057 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3060 Indeterminate => panic!("indeterminate unexpected"),
3061 Success((resulting_module, resulting_last_private)) => {
3062 containing_module = resulting_module;
3063 last_private = resulting_last_private;
3067 let name = segments.last().unwrap().identifier.name;
3068 let def = match self.resolve_name_in_module(containing_module.clone(),
3071 NameSearchType::PathSearch,
3073 Success((Target { binding, .. }, _)) => {
3074 let (def, lp) = binding.def_and_lp();
3075 (def, last_private.or(lp))
3079 if let Some(DefId{krate: kid, ..}) = containing_module.def_id() {
3080 self.used_crates.insert(kid);
3085 /// Invariant: This must be called only during main resolution, not during
3086 /// import resolution.
3087 fn resolve_crate_relative_path(&mut self,
3089 segments: &[hir::PathSegment],
3090 namespace: Namespace)
3091 -> Option<(Def, LastPrivate)> {
3092 let module_path = segments.split_last()
3096 .map(|ps| ps.identifier.name)
3097 .collect::<Vec<_>>();
3099 let root_module = self.graph_root.clone();
3101 let containing_module;
3103 match self.resolve_module_path_from_root(root_module,
3108 LastMod(AllPublic)) {
3110 let (span, msg) = match err {
3111 Some((span, msg)) => (span, msg),
3113 let msg = format!("Use of undeclared module `::{}`",
3114 names_to_string(&module_path[..]));
3119 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3124 panic!("indeterminate unexpected");
3127 Success((resulting_module, resulting_last_private)) => {
3128 containing_module = resulting_module;
3129 last_private = resulting_last_private;
3133 let name = segments.last().unwrap().identifier.name;
3134 match self.resolve_name_in_module(containing_module,
3137 NameSearchType::PathSearch,
3139 Success((Target { binding, .. }, _)) => {
3140 let (def, lp) = binding.def_and_lp();
3141 Some((def, last_private.or(lp)))
3147 fn resolve_identifier_in_local_ribs(&mut self,
3149 namespace: Namespace)
3150 -> Option<LocalDef> {
3151 // Check the local set of ribs.
3152 let (name, ribs) = match namespace {
3153 ValueNS => (ident.name, &self.value_ribs),
3154 TypeNS => (ident.unhygienic_name, &self.type_ribs),
3157 for (i, rib) in ribs.iter().enumerate().rev() {
3158 if let Some(def_like) = rib.bindings.get(&name).cloned() {
3161 debug!("(resolving path in local ribs) resolved `{}` to {:?} at {}",
3165 return Some(LocalDef {
3166 ribs: Some((namespace, i)),
3171 debug!("(resolving path in local ribs) resolved `{}` to pseudo-def {:?}",
3183 fn resolve_item_by_name_in_lexical_scope(&mut self,
3185 namespace: Namespace)
3188 let module = self.current_module.clone();
3189 match self.resolve_item_in_lexical_scope(module, name, namespace) {
3190 Success((target, _)) => {
3191 match target.binding.def() {
3193 // This can happen if we were looking for a type and
3194 // found a module instead. Modules don't have defs.
3195 debug!("(resolving item path by identifier in lexical scope) failed to \
3196 resolve {} after success...",
3201 debug!("(resolving item path in lexical scope) resolved `{}` to item",
3203 // This lookup is "all public" because it only searched
3204 // for one identifier in the current module (couldn't
3205 // have passed through reexports or anything like that.
3211 panic!("unexpected indeterminate result");
3214 debug!("(resolving item path by identifier in lexical scope) failed to resolve {}",
3217 if let Some((span, msg)) = err {
3218 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg))
3226 fn with_no_errors<T, F>(&mut self, f: F) -> T
3227 where F: FnOnce(&mut Resolver) -> T
3229 self.emit_errors = false;
3231 self.emit_errors = true;
3235 fn find_fallback_in_self_type(&mut self, name: Name) -> FallbackSuggestion {
3236 fn extract_path_and_node_id(t: &Ty,
3237 allow: FallbackChecks)
3238 -> Option<(Path, NodeId, FallbackChecks)> {
3240 TyPath(None, ref path) => Some((path.clone(), t.id, allow)),
3241 TyPtr(ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, OnlyTraitAndStatics),
3242 TyRptr(_, ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, allow),
3243 // This doesn't handle the remaining `Ty` variants as they are not
3244 // that commonly the self_type, it might be interesting to provide
3245 // support for those in future.
3250 fn get_module(this: &mut Resolver,
3252 name_path: &[ast::Name])
3253 -> Option<Rc<Module>> {
3254 let root = this.current_module.clone();
3255 let last_name = name_path.last().unwrap();
3257 if name_path.len() == 1 {
3258 match this.primitive_type_table.primitive_types.get(last_name) {
3261 match this.current_module.children.borrow().get(last_name) {
3262 Some(child) => child.type_ns.module(),
3268 match this.resolve_module_path(root,
3273 Success((module, _)) => Some(module),
3279 fn is_static_method(this: &Resolver, did: DefId) -> bool {
3280 if let Some(node_id) = this.ast_map.as_local_node_id(did) {
3281 let sig = match this.ast_map.get(node_id) {
3282 hir_map::NodeTraitItem(trait_item) => match trait_item.node {
3283 hir::MethodTraitItem(ref sig, _) => sig,
3286 hir_map::NodeImplItem(impl_item) => match impl_item.node {
3287 hir::ImplItemKind::Method(ref sig, _) => sig,
3292 sig.explicit_self.node == hir::SelfStatic
3294 this.session.cstore.is_static_method(did)
3298 let (path, node_id, allowed) = match self.current_self_type {
3299 Some(ref ty) => match extract_path_and_node_id(ty, Everything) {
3301 None => return NoSuggestion,
3303 None => return NoSuggestion,
3306 if allowed == Everything {
3307 // Look for a field with the same name in the current self_type.
3308 match self.def_map.borrow().get(&node_id).map(|d| d.full_def()) {
3309 Some(DefTy(did, _)) |
3310 Some(DefStruct(did)) |
3311 Some(DefVariant(_, did, _)) => match self.structs.get(&did) {
3314 if fields.iter().any(|&field_name| name == field_name) {
3319 _ => {} // Self type didn't resolve properly
3323 let name_path = path.segments.iter().map(|seg| seg.identifier.name).collect::<Vec<_>>();
3325 // Look for a method in the current self type's impl module.
3326 if let Some(module) = get_module(self, path.span, &name_path) {
3327 if let Some(binding) = module.children.borrow().get(&name) {
3328 if let Some(DefMethod(did)) = binding.value_ns.def() {
3329 if is_static_method(self, did) {
3330 return StaticMethod(path_names_to_string(&path, 0));
3332 if self.current_trait_ref.is_some() {
3334 } else if allowed == Everything {
3341 // Look for a method in the current trait.
3342 if let Some((trait_did, ref trait_ref)) = self.current_trait_ref {
3343 if let Some(&did) = self.trait_item_map.get(&(name, trait_did)) {
3344 if is_static_method(self, did) {
3345 return TraitMethod(path_names_to_string(&trait_ref.path, 0));
3355 fn find_best_match_for_name(&mut self, name: &str) -> SuggestionType {
3356 let mut maybes: Vec<token::InternedString> = Vec::new();
3357 let mut values: Vec<usize> = Vec::new();
3359 if let Some(macro_name) = self.session.available_macros
3360 .borrow().iter().find(|n| n.as_str() == name) {
3361 return SuggestionType::Macro(format!("{}!", macro_name));
3364 for rib in self.value_ribs.iter().rev() {
3365 for (&k, _) in &rib.bindings {
3366 maybes.push(k.as_str());
3367 values.push(usize::MAX);
3371 let mut smallest = 0;
3372 for (i, other) in maybes.iter().enumerate() {
3373 values[i] = lev_distance(name, &other);
3375 if values[i] <= values[smallest] {
3380 let max_distance = max_suggestion_distance(name);
3381 if !values.is_empty() && values[smallest] <= max_distance && name != &maybes[smallest][..] {
3383 SuggestionType::Function(maybes[smallest].to_string())
3386 SuggestionType::NotFound
3390 fn resolve_expr(&mut self, expr: &Expr) {
3391 // First, record candidate traits for this expression if it could
3392 // result in the invocation of a method call.
3394 self.record_candidate_traits_for_expr_if_necessary(expr);
3396 // Next, resolve the node.
3398 ExprPath(ref maybe_qself, ref path) => {
3399 let resolution = match self.resolve_possibly_assoc_item(expr.id,
3400 maybe_qself.as_ref(),
3404 // `<T>::a::b::c` is resolved by typeck alone.
3405 TypecheckRequired => {
3406 let method_name = path.segments.last().unwrap().identifier.name;
3407 let traits = self.get_traits_containing_item(method_name);
3408 self.trait_map.insert(expr.id, traits);
3409 intravisit::walk_expr(self, expr);
3412 ResolveAttempt(resolution) => resolution,
3415 // This is a local path in the value namespace. Walk through
3416 // scopes looking for it.
3417 if let Some(path_res) = resolution {
3418 // Check if struct variant
3419 if let DefVariant(_, _, true) = path_res.base_def {
3420 let path_name = path_names_to_string(path, 0);
3424 ResolutionError::StructVariantUsedAsFunction(&*path_name));
3426 let msg = format!("did you mean to write: `{} {{ /* fields */ }}`?",
3428 if self.emit_errors {
3429 self.session.fileline_help(expr.span, &msg);
3431 self.session.span_help(expr.span, &msg);
3434 // Write the result into the def map.
3435 debug!("(resolving expr) resolved `{}`",
3436 path_names_to_string(path, 0));
3438 // Partial resolutions will need the set of traits in scope,
3439 // so they can be completed during typeck.
3440 if path_res.depth != 0 {
3441 let method_name = path.segments.last().unwrap().identifier.name;
3442 let traits = self.get_traits_containing_item(method_name);
3443 self.trait_map.insert(expr.id, traits);
3446 self.record_def(expr.id, path_res);
3449 // Be helpful if the name refers to a struct
3450 // (The pattern matching def_tys where the id is in self.structs
3451 // matches on regular structs while excluding tuple- and enum-like
3452 // structs, which wouldn't result in this error.)
3453 let path_name = path_names_to_string(path, 0);
3454 let type_res = self.with_no_errors(|this| {
3455 this.resolve_path(expr.id, path, 0, TypeNS, false)
3457 match type_res.map(|r| r.base_def) {
3458 Some(DefTy(struct_id, _)) if self.structs.contains_key(&struct_id) => {
3462 ResolutionError::StructVariantUsedAsFunction(
3466 let msg = format!("did you mean to write: `{} {{ /* fields */ }}`?",
3468 if self.emit_errors {
3469 self.session.fileline_help(expr.span, &msg);
3471 self.session.span_help(expr.span, &msg);
3475 // Keep reporting some errors even if they're ignored above.
3476 self.resolve_path(expr.id, path, 0, ValueNS, true);
3478 let mut method_scope = false;
3479 self.value_ribs.iter().rev().all(|rib| {
3480 method_scope = match rib.kind {
3481 MethodRibKind => true,
3482 ItemRibKind | ConstantItemRibKind => false,
3483 _ => return true, // Keep advancing
3485 false // Stop advancing
3488 if method_scope && special_names::self_.as_str() == &path_name[..] {
3491 ResolutionError::SelfNotAvailableInStaticMethod);
3493 let last_name = path.segments.last().unwrap().identifier.name;
3494 let mut msg = match self.find_fallback_in_self_type(last_name) {
3496 // limit search to 5 to reduce the number
3497 // of stupid suggestions
3498 match self.find_best_match_for_name(&path_name) {
3499 SuggestionType::Macro(s) => {
3500 format!("the macro `{}`", s)
3502 SuggestionType::Function(s) => format!("`{}`", s),
3503 SuggestionType::NotFound => "".to_string(),
3506 Field => format!("`self.{}`", path_name),
3508 TraitItem => format!("to call `self.{}`", path_name),
3509 TraitMethod(path_str) |
3510 StaticMethod(path_str) =>
3511 format!("to call `{}::{}`", path_str, path_name),
3514 if !msg.is_empty() {
3515 msg = format!(". Did you mean {}?", msg)
3520 ResolutionError::UnresolvedName(&*path_name, &*msg));
3526 intravisit::walk_expr(self, expr);
3529 ExprStruct(ref path, _, _) => {
3530 // Resolve the path to the structure it goes to. We don't
3531 // check to ensure that the path is actually a structure; that
3532 // is checked later during typeck.
3533 match self.resolve_path(expr.id, path, 0, TypeNS, false) {
3534 Some(definition) => self.record_def(expr.id, definition),
3536 debug!("(resolving expression) didn't find struct def",);
3540 ResolutionError::DoesNotNameAStruct(
3541 &*path_names_to_string(path, 0))
3546 intravisit::walk_expr(self, expr);
3549 ExprLoop(_, Some(label)) | ExprWhile(_, _, Some(label)) => {
3550 self.with_label_rib(|this| {
3551 let def_like = DlDef(DefLabel(expr.id));
3554 let rib = this.label_ribs.last_mut().unwrap();
3555 rib.bindings.insert(label.name, def_like);
3558 intravisit::walk_expr(this, expr);
3562 ExprBreak(Some(label)) | ExprAgain(Some(label)) => {
3563 match self.search_label(label.node.name) {
3567 ResolutionError::UndeclaredLabel(&label.node.name.as_str()))
3569 Some(DlDef(def @ DefLabel(_))) => {
3570 // Since this def is a label, it is never read.
3571 self.record_def(expr.id,
3574 last_private: LastMod(AllPublic),
3579 self.session.span_bug(expr.span, "label wasn't mapped to a label def!")
3585 intravisit::walk_expr(self, expr);
3590 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3592 ExprField(_, name) => {
3593 // FIXME(#6890): Even though you can't treat a method like a
3594 // field, we need to add any trait methods we find that match
3595 // the field name so that we can do some nice error reporting
3596 // later on in typeck.
3597 let traits = self.get_traits_containing_item(name.node);
3598 self.trait_map.insert(expr.id, traits);
3600 ExprMethodCall(name, _, _) => {
3601 debug!("(recording candidate traits for expr) recording traits for {}",
3603 let traits = self.get_traits_containing_item(name.node);
3604 self.trait_map.insert(expr.id, traits);
3612 fn get_traits_containing_item(&mut self, name: Name) -> Vec<DefId> {
3613 debug!("(getting traits containing item) looking for '{}'", name);
3615 fn add_trait_info(found_traits: &mut Vec<DefId>, trait_def_id: DefId, name: Name) {
3616 debug!("(adding trait info) found trait {:?} for method '{}'",
3619 found_traits.push(trait_def_id);
3622 let mut found_traits = Vec::new();
3623 let mut search_module = self.current_module.clone();
3625 // Look for the current trait.
3626 match self.current_trait_ref {
3627 Some((trait_def_id, _)) => {
3628 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3629 add_trait_info(&mut found_traits, trait_def_id, name);
3632 None => {} // Nothing to do.
3635 // Look for trait children.
3636 build_reduced_graph::populate_module_if_necessary(self, &search_module);
3639 for (_, child_names) in search_module.children.borrow().iter() {
3640 let def = match child_names.type_ns.def() {
3644 let trait_def_id = match def {
3645 DefTrait(trait_def_id) => trait_def_id,
3648 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3649 add_trait_info(&mut found_traits, trait_def_id, name);
3654 // Look for imports.
3655 for (_, import) in search_module.import_resolutions.borrow().iter() {
3656 let target = match import.type_ns.target {
3658 Some(ref target) => target,
3660 let did = match target.binding.def() {
3661 Some(DefTrait(trait_def_id)) => trait_def_id,
3662 Some(..) | None => continue,
3664 if self.trait_item_map.contains_key(&(name, did)) {
3665 add_trait_info(&mut found_traits, did, name);
3666 let id = import.type_ns.id;
3667 self.used_imports.insert((id, TypeNS));
3668 let trait_name = self.get_trait_name(did);
3669 self.record_import_use(id, trait_name);
3670 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id() {
3671 self.used_crates.insert(kid);
3676 match search_module.parent_link.clone() {
3677 NoParentLink | ModuleParentLink(..) => break,
3678 BlockParentLink(parent_module, _) => {
3679 search_module = parent_module.upgrade().unwrap();
3687 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
3688 debug!("(recording def) recording {:?} for {}", resolution, node_id);
3689 assert!(match resolution.last_private {
3690 LastImport{..} => false,
3693 "Import should only be used for `use` directives");
3695 if let Some(prev_res) = self.def_map.borrow_mut().insert(node_id, resolution) {
3696 let span = self.ast_map.opt_span(node_id).unwrap_or(codemap::DUMMY_SP);
3697 self.session.span_bug(span,
3698 &format!("path resolved multiple times ({:?} before, {:?} now)",
3704 fn enforce_default_binding_mode(&mut self,
3706 pat_binding_mode: BindingMode,
3708 match pat_binding_mode {
3709 BindByValue(_) => {}
3713 ResolutionError::CannotUseRefBindingModeWith(descr));
3721 // Diagnostics are not particularly efficient, because they're rarely
3725 #[allow(dead_code)] // useful for debugging
3726 fn dump_module(&mut self, module_: Rc<Module>) {
3727 debug!("Dump of module `{}`:", module_to_string(&*module_));
3729 debug!("Children:");
3730 build_reduced_graph::populate_module_if_necessary(self, &module_);
3731 for (&name, _) in module_.children.borrow().iter() {
3732 debug!("* {}", name);
3735 debug!("Import resolutions:");
3736 let import_resolutions = module_.import_resolutions.borrow();
3737 for (&name, import_resolution) in import_resolutions.iter() {
3739 match import_resolution.value_ns.target {
3741 value_repr = "".to_string();
3744 value_repr = " value:?".to_string();
3750 match import_resolution.type_ns.target {
3752 type_repr = "".to_string();
3755 type_repr = " type:?".to_string();
3760 debug!("* {}:{}{}", name, value_repr, type_repr);
3766 fn names_to_string(names: &[Name]) -> String {
3767 let mut first = true;
3768 let mut result = String::new();
3773 result.push_str("::")
3775 result.push_str(&name.as_str());
3780 fn path_names_to_string(path: &Path, depth: usize) -> String {
3781 let names: Vec<ast::Name> = path.segments[..path.segments.len() - depth]
3783 .map(|seg| seg.identifier.name)
3785 names_to_string(&names[..])
3788 /// A somewhat inefficient routine to obtain the name of a module.
3789 fn module_to_string(module: &Module) -> String {
3790 let mut names = Vec::new();
3792 fn collect_mod(names: &mut Vec<ast::Name>, module: &Module) {
3793 match module.parent_link {
3795 ModuleParentLink(ref module, name) => {
3797 collect_mod(names, &*module.upgrade().unwrap());
3799 BlockParentLink(ref module, _) => {
3800 // danger, shouldn't be ident?
3801 names.push(special_idents::opaque.name);
3802 collect_mod(names, &*module.upgrade().unwrap());
3806 collect_mod(&mut names, module);
3808 if names.is_empty() {
3809 return "???".to_string();
3811 names_to_string(&names.into_iter().rev().collect::<Vec<ast::Name>>())
3815 pub struct CrateMap {
3816 pub def_map: RefCell<DefMap>,
3817 pub freevars: FreevarMap,
3818 pub export_map: ExportMap,
3819 pub trait_map: TraitMap,
3820 pub external_exports: ExternalExports,
3821 pub glob_map: Option<GlobMap>,
3824 #[derive(PartialEq,Copy, Clone)]
3825 pub enum MakeGlobMap {
3830 /// Entry point to crate resolution.
3831 pub fn resolve_crate<'a, 'tcx>(session: &'a Session,
3832 ast_map: &'a hir_map::Map<'tcx>,
3833 make_glob_map: MakeGlobMap)
3835 let krate = ast_map.krate();
3836 let mut resolver = create_resolver(session, ast_map, krate, make_glob_map, None);
3838 resolver.resolve_crate(krate);
3839 session.abort_if_errors();
3841 check_unused::check_crate(&mut resolver, krate);
3844 def_map: resolver.def_map,
3845 freevars: resolver.freevars,
3846 export_map: resolver.export_map,
3847 trait_map: resolver.trait_map,
3848 external_exports: resolver.external_exports,
3849 glob_map: if resolver.make_glob_map {
3850 Some(resolver.glob_map)
3857 /// Builds a name resolution walker to be used within this module,
3858 /// or used externally, with an optional callback function.
3860 /// The callback takes a &mut bool which allows callbacks to end a
3861 /// walk when set to true, passing through the rest of the walk, while
3862 /// preserving the ribs + current module. This allows resolve_path
3863 /// calls to be made with the correct scope info. The node in the
3864 /// callback corresponds to the current node in the walk.
3865 pub fn create_resolver<'a, 'tcx>(session: &'a Session,
3866 ast_map: &'a hir_map::Map<'tcx>,
3868 make_glob_map: MakeGlobMap,
3869 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>)
3870 -> Resolver<'a, 'tcx> {
3871 let mut resolver = Resolver::new(session, ast_map, make_glob_map);
3873 resolver.callback = callback;
3875 build_reduced_graph::build_reduced_graph(&mut resolver, krate);
3876 session.abort_if_errors();
3878 resolve_imports::resolve_imports(&mut resolver);
3879 session.abort_if_errors();
3881 record_exports::record(&mut resolver);
3882 session.abort_if_errors();
3887 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }