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, 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, ImportResolutionPerNamespace};
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
569 self.record_def(tref.trait_ref.ref_id, err_path_resolution())
572 intravisit::walk_poly_trait_ref(self, tref, m);
574 fn visit_variant(&mut self,
575 variant: &hir::Variant,
577 item_id: ast::NodeId) {
578 execute_callback!(hir_map::Node::NodeVariant(variant), self);
579 if let Some(ref dis_expr) = variant.node.disr_expr {
580 // resolve the discriminator expr as a constant
581 self.with_constant_rib(|this| {
582 this.visit_expr(dis_expr);
586 // `intravisit::walk_variant` without the discriminant expression.
587 self.visit_variant_data(&variant.node.data,
593 fn visit_foreign_item(&mut self, foreign_item: &hir::ForeignItem) {
594 execute_callback!(hir_map::Node::NodeForeignItem(foreign_item), self);
595 let type_parameters = match foreign_item.node {
596 ForeignItemFn(_, ref generics) => {
597 HasTypeParameters(generics, FnSpace, ItemRibKind)
599 ForeignItemStatic(..) => NoTypeParameters,
601 self.with_type_parameter_rib(type_parameters, |this| {
602 intravisit::walk_foreign_item(this, foreign_item);
605 fn visit_fn(&mut self,
606 function_kind: FnKind<'v>,
607 declaration: &'v FnDecl,
611 let rib_kind = match function_kind {
612 FnKind::ItemFn(_, generics, _, _, _, _) => {
613 self.visit_generics(generics);
616 FnKind::Method(_, sig, _) => {
617 self.visit_generics(&sig.generics);
618 self.visit_explicit_self(&sig.explicit_self);
621 FnKind::Closure => ClosureRibKind(node_id),
623 self.resolve_function(rib_kind, declaration, block);
627 type ErrorMessage = Option<(Span, String)>;
629 enum ResolveResult<T> {
630 Failed(ErrorMessage), // Failed to resolve the name, optional helpful error message.
631 Indeterminate, // Couldn't determine due to unresolved globs.
632 Success(T), // Successfully resolved the import.
635 impl<T> ResolveResult<T> {
636 fn success(&self) -> bool {
644 enum FallbackSuggestion {
649 StaticMethod(String),
653 #[derive(Copy, Clone)]
654 enum TypeParameters<'a> {
656 HasTypeParameters(// Type parameters.
659 // Identifies the things that these parameters
660 // were declared on (type, fn, etc)
663 // The kind of the rib used for type parameters.
667 // The rib kind controls the translation of local
668 // definitions (`DefLocal`) to upvars (`DefUpvar`).
669 #[derive(Copy, Clone, Debug)]
671 // No translation needs to be applied.
674 // We passed through a closure scope at the given node ID.
675 // Translate upvars as appropriate.
676 ClosureRibKind(NodeId /* func id */),
678 // We passed through an impl or trait and are now in one of its
679 // methods. Allow references to ty params that impl or trait
680 // binds. Disallow any other upvars (including other ty params that are
684 // We passed through an item scope. Disallow upvars.
687 // We're in a constant item. Can't refer to dynamic stuff.
691 #[derive(Copy, Clone)]
692 enum UseLexicalScopeFlag {
697 enum ModulePrefixResult {
699 PrefixFound(Rc<Module>, usize),
702 #[derive(Copy, Clone)]
703 enum AssocItemResolveResult {
704 /// Syntax such as `<T>::item`, which can't be resolved until type
707 /// We should have been able to resolve the associated item.
708 ResolveAttempt(Option<PathResolution>),
711 #[derive(Copy, Clone, PartialEq)]
712 enum NameSearchType {
713 /// We're doing a name search in order to resolve a `use` directive.
716 /// We're doing a name search in order to resolve a path type, a path
717 /// expression, or a path pattern.
721 #[derive(Copy, Clone)]
722 enum BareIdentifierPatternResolution {
723 FoundStructOrEnumVariant(Def, LastPrivate),
724 FoundConst(Def, LastPrivate, Name),
725 BareIdentifierPatternUnresolved,
731 bindings: HashMap<Name, DefLike>,
736 fn new(kind: RibKind) -> Rib {
738 bindings: HashMap::new(),
744 /// A definition along with the index of the rib it was found on
746 ribs: Option<(Namespace, usize)>,
751 fn from_def(def: Def) -> Self {
759 /// The link from a module up to its nearest parent node.
760 #[derive(Clone,Debug)]
763 ModuleParentLink(Weak<Module>, Name),
764 BlockParentLink(Weak<Module>, NodeId),
767 /// One node in the tree of modules.
769 parent_link: ParentLink,
770 def: Cell<Option<Def>>,
773 children: RefCell<HashMap<Name, NameBindings>>,
774 imports: RefCell<Vec<ImportDirective>>,
776 // The external module children of this node that were declared with
778 external_module_children: RefCell<HashMap<Name, Rc<Module>>>,
780 // The anonymous children of this node. Anonymous children are pseudo-
781 // modules that are implicitly created around items contained within
784 // For example, if we have this:
792 // There will be an anonymous module created around `g` with the ID of the
793 // entry block for `f`.
794 anonymous_children: RefCell<NodeMap<Rc<Module>>>,
796 // The status of resolving each import in this module.
797 import_resolutions: RefCell<HashMap<Name, ImportResolutionPerNamespace>>,
799 // The number of unresolved globs that this module exports.
800 glob_count: Cell<usize>,
802 // The number of unresolved pub imports (both regular and globs) in this module
803 pub_count: Cell<usize>,
805 // The number of unresolved pub glob imports in this module
806 pub_glob_count: Cell<usize>,
808 // The index of the import we're resolving.
809 resolved_import_count: Cell<usize>,
811 // Whether this module is populated. If not populated, any attempt to
812 // access the children must be preceded with a
813 // `populate_module_if_necessary` call.
814 populated: Cell<bool>,
818 fn new(parent_link: ParentLink,
824 parent_link: parent_link,
826 is_public: is_public,
827 children: RefCell::new(HashMap::new()),
828 imports: RefCell::new(Vec::new()),
829 external_module_children: RefCell::new(HashMap::new()),
830 anonymous_children: RefCell::new(NodeMap()),
831 import_resolutions: RefCell::new(HashMap::new()),
832 glob_count: Cell::new(0),
833 pub_count: Cell::new(0),
834 pub_glob_count: Cell::new(0),
835 resolved_import_count: Cell::new(0),
836 populated: Cell::new(!external),
840 fn def_id(&self) -> Option<DefId> {
841 self.def.get().as_ref().map(Def::def_id)
844 fn is_normal(&self) -> bool {
845 match self.def.get() {
846 Some(DefMod(_)) | Some(DefForeignMod(_)) => true,
851 fn is_trait(&self) -> bool {
852 match self.def.get() {
853 Some(DefTrait(_)) => true,
858 fn all_imports_resolved(&self) -> bool {
859 if self.imports.borrow_state() == ::std::cell::BorrowState::Writing {
860 // it is currently being resolved ! so nope
863 self.imports.borrow().len() == self.resolved_import_count.get()
869 pub fn inc_glob_count(&self) {
870 self.glob_count.set(self.glob_count.get() + 1);
872 pub fn dec_glob_count(&self) {
873 assert!(self.glob_count.get() > 0);
874 self.glob_count.set(self.glob_count.get() - 1);
876 pub fn inc_pub_count(&self) {
877 self.pub_count.set(self.pub_count.get() + 1);
879 pub fn dec_pub_count(&self) {
880 assert!(self.pub_count.get() > 0);
881 self.pub_count.set(self.pub_count.get() - 1);
883 pub fn inc_pub_glob_count(&self) {
884 self.pub_glob_count.set(self.pub_glob_count.get() + 1);
886 pub fn dec_pub_glob_count(&self) {
887 assert!(self.pub_glob_count.get() > 0);
888 self.pub_glob_count.set(self.pub_glob_count.get() - 1);
892 impl fmt::Debug for Module {
893 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
907 flags DefModifiers: u8 {
908 // Enum variants are always considered `PUBLIC`, this is needed for `use Enum::Variant`
909 // or `use Enum::*` to work on private enums.
910 const PUBLIC = 1 << 0,
911 const IMPORTABLE = 1 << 1,
912 // Variants are considered `PUBLIC`, but some of them live in private enums.
913 // We need to track them to prohibit reexports like `pub use PrivEnum::Variant`.
914 const PRIVATE_VARIANT = 1 << 2,
918 // Records a possibly-private value, type, or module definition.
921 modifiers: DefModifiers, // see note in ImportResolutionPerNamespace about how to use this
922 def_or_module: DefOrModule,
933 fn create_from_module(module: Rc<Module>, span: Option<Span>) -> Self {
934 let modifiers = if module.is_public {
937 DefModifiers::empty()
938 } | DefModifiers::IMPORTABLE;
940 NsDef { modifiers: modifiers, def_or_module: DefOrModule::Module(module), span: span }
943 fn create_from_def(def: Def, modifiers: DefModifiers, span: Option<Span>) -> Self {
944 NsDef { modifiers: modifiers, def_or_module: DefOrModule::Def(def), span: span }
947 fn module(&self) -> Option<Rc<Module>> {
948 match self.def_or_module {
949 DefOrModule::Module(ref module) => Some(module.clone()),
950 DefOrModule::Def(_) => None,
954 fn def(&self) -> Option<Def> {
955 match self.def_or_module {
956 DefOrModule::Def(def) => Some(def),
957 DefOrModule::Module(ref module) => module.def.get(),
962 // Records at most one definition that a name in a namespace is bound to
963 #[derive(Clone,Debug)]
964 pub struct NameBinding(Rc<RefCell<Option<NsDef>>>);
968 NameBinding(Rc::new(RefCell::new(None)))
971 fn create_from_module(module: Rc<Module>) -> Self {
972 NameBinding(Rc::new(RefCell::new(Some(NsDef::create_from_module(module, None)))))
975 fn set(&self, ns_def: NsDef) {
976 *self.0.borrow_mut() = Some(ns_def);
979 fn set_modifiers(&self, modifiers: DefModifiers) {
980 if let Some(ref mut ns_def) = *self.0.borrow_mut() {
981 ns_def.modifiers = modifiers
985 fn borrow(&self) -> ::std::cell::Ref<Option<NsDef>> {
989 // Lifted versions of the NsDef methods and fields
990 fn def(&self) -> Option<Def> {
991 self.borrow().as_ref().and_then(NsDef::def)
993 fn module(&self) -> Option<Rc<Module>> {
994 self.borrow().as_ref().and_then(NsDef::module)
996 fn span(&self) -> Option<Span> {
997 self.borrow().as_ref().and_then(|def| def.span)
999 fn modifiers(&self) -> Option<DefModifiers> {
1000 self.borrow().as_ref().and_then(|def| Some(def.modifiers))
1003 fn defined(&self) -> bool {
1004 self.borrow().is_some()
1007 fn defined_with(&self, modifiers: DefModifiers) -> bool {
1008 self.modifiers().map(|m| m.contains(modifiers)).unwrap_or(false)
1011 fn is_public(&self) -> bool {
1012 self.defined_with(DefModifiers::PUBLIC)
1015 fn def_and_lp(&self) -> (Def, LastPrivate) {
1016 let def = self.def().unwrap();
1017 (def, LastMod(if self.is_public() { AllPublic } else { DependsOn(def.def_id()) }))
1021 // Records the definitions (at most one for each namespace) that a name is
1023 #[derive(Clone,Debug)]
1024 pub struct NameBindings {
1025 type_ns: NameBinding, // < Meaning in type namespace.
1026 value_ns: NameBinding, // < Meaning in value namespace.
1029 impl ::std::ops::Index<Namespace> for NameBindings {
1030 type Output = NameBinding;
1031 fn index(&self, namespace: Namespace) -> &NameBinding {
1032 match namespace { TypeNS => &self.type_ns, ValueNS => &self.value_ns }
1037 fn new() -> NameBindings {
1039 type_ns: NameBinding::new(),
1040 value_ns: NameBinding::new(),
1044 /// Creates a new module in this set of name bindings.
1045 fn define_module(&self, module: Rc<Module>, sp: Span) {
1046 self.type_ns.set(NsDef::create_from_module(module, Some(sp)));
1049 /// Records a type definition.
1050 fn define_type(&self, def: Def, sp: Span, modifiers: DefModifiers) {
1051 debug!("defining type for def {:?} with modifiers {:?}", def, modifiers);
1052 self.type_ns.set(NsDef::create_from_def(def, modifiers, Some(sp)));
1055 /// Records a value definition.
1056 fn define_value(&self, def: Def, sp: Span, modifiers: DefModifiers) {
1057 debug!("defining value for def {:?} with modifiers {:?}", def, modifiers);
1058 self.value_ns.set(NsDef::create_from_def(def, modifiers, Some(sp)));
1062 /// Interns the names of the primitive types.
1063 struct PrimitiveTypeTable {
1064 primitive_types: HashMap<Name, PrimTy>,
1067 impl PrimitiveTypeTable {
1068 fn new() -> PrimitiveTypeTable {
1069 let mut table = PrimitiveTypeTable { primitive_types: HashMap::new() };
1071 table.intern("bool", TyBool);
1072 table.intern("char", TyChar);
1073 table.intern("f32", TyFloat(TyF32));
1074 table.intern("f64", TyFloat(TyF64));
1075 table.intern("isize", TyInt(TyIs));
1076 table.intern("i8", TyInt(TyI8));
1077 table.intern("i16", TyInt(TyI16));
1078 table.intern("i32", TyInt(TyI32));
1079 table.intern("i64", TyInt(TyI64));
1080 table.intern("str", TyStr);
1081 table.intern("usize", TyUint(TyUs));
1082 table.intern("u8", TyUint(TyU8));
1083 table.intern("u16", TyUint(TyU16));
1084 table.intern("u32", TyUint(TyU32));
1085 table.intern("u64", TyUint(TyU64));
1090 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1091 self.primitive_types.insert(token::intern(string), primitive_type);
1095 /// The main resolver class.
1096 pub struct Resolver<'a, 'tcx: 'a> {
1097 session: &'a Session,
1099 ast_map: &'a hir_map::Map<'tcx>,
1101 graph_root: Rc<Module>,
1103 trait_item_map: FnvHashMap<(Name, DefId), DefId>,
1105 structs: FnvHashMap<DefId, Vec<Name>>,
1107 // The number of imports that are currently unresolved.
1108 unresolved_imports: usize,
1110 // The module that represents the current item scope.
1111 current_module: Rc<Module>,
1113 // The current set of local scopes, for values.
1114 // FIXME #4948: Reuse ribs to avoid allocation.
1115 value_ribs: Vec<Rib>,
1117 // The current set of local scopes, for types.
1118 type_ribs: Vec<Rib>,
1120 // The current set of local scopes, for labels.
1121 label_ribs: Vec<Rib>,
1123 // The trait that the current context can refer to.
1124 current_trait_ref: Option<(DefId, TraitRef)>,
1126 // The current self type if inside an impl (used for better errors).
1127 current_self_type: Option<Ty>,
1129 // The idents for the primitive types.
1130 primitive_type_table: PrimitiveTypeTable,
1132 def_map: RefCell<DefMap>,
1133 freevars: FreevarMap,
1134 freevars_seen: NodeMap<NodeMap<usize>>,
1135 export_map: ExportMap,
1136 trait_map: TraitMap,
1137 external_exports: ExternalExports,
1139 // Whether or not to print error messages. Can be set to true
1140 // when getting additional info for error message suggestions,
1141 // so as to avoid printing duplicate errors
1144 make_glob_map: bool,
1145 // Maps imports to the names of items actually imported (this actually maps
1146 // all imports, but only glob imports are actually interesting).
1149 used_imports: HashSet<(NodeId, Namespace)>,
1150 used_crates: HashSet<CrateNum>,
1152 // Callback function for intercepting walks
1153 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>,
1154 // The intention is that the callback modifies this flag.
1155 // Once set, the resolver falls out of the walk, preserving the ribs.
1159 #[derive(PartialEq)]
1160 enum FallbackChecks {
1162 OnlyTraitAndStatics,
1165 impl<'a, 'tcx> Resolver<'a, 'tcx> {
1166 fn new(session: &'a Session,
1167 ast_map: &'a hir_map::Map<'tcx>,
1168 make_glob_map: MakeGlobMap)
1169 -> Resolver<'a, 'tcx> {
1170 let root_def_id = ast_map.local_def_id(CRATE_NODE_ID);
1171 let graph_root = Module::new(NoParentLink, Some(DefMod(root_def_id)), false, true);
1178 // The outermost module has def ID 0; this is not reflected in the
1180 graph_root: graph_root.clone(),
1182 trait_item_map: FnvHashMap(),
1183 structs: FnvHashMap(),
1185 unresolved_imports: 0,
1187 current_module: graph_root,
1188 value_ribs: Vec::new(),
1189 type_ribs: Vec::new(),
1190 label_ribs: Vec::new(),
1192 current_trait_ref: None,
1193 current_self_type: None,
1195 primitive_type_table: PrimitiveTypeTable::new(),
1197 def_map: RefCell::new(NodeMap()),
1198 freevars: NodeMap(),
1199 freevars_seen: NodeMap(),
1200 export_map: NodeMap(),
1201 trait_map: NodeMap(),
1202 used_imports: HashSet::new(),
1203 used_crates: HashSet::new(),
1204 external_exports: DefIdSet(),
1207 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1208 glob_map: HashMap::new(),
1216 fn record_import_use(&mut self, import_id: NodeId, name: Name) {
1217 if !self.make_glob_map {
1220 if self.glob_map.contains_key(&import_id) {
1221 self.glob_map.get_mut(&import_id).unwrap().insert(name);
1225 let mut new_set = HashSet::new();
1226 new_set.insert(name);
1227 self.glob_map.insert(import_id, new_set);
1230 fn get_trait_name(&self, did: DefId) -> Name {
1231 if let Some(node_id) = self.ast_map.as_local_node_id(did) {
1232 self.ast_map.expect_item(node_id).name
1234 self.session.cstore.item_name(did)
1238 /// Checks that the names of external crates don't collide with other
1239 /// external crates.
1240 fn check_for_conflicts_between_external_crates(&self,
1244 if module.external_module_children.borrow().contains_key(&name) {
1245 span_err!(self.session,
1248 "an external crate named `{}` has already been imported into this module",
1253 /// Checks that the names of items don't collide with external crates.
1254 fn check_for_conflicts_between_external_crates_and_items(&self,
1258 if module.external_module_children.borrow().contains_key(&name) {
1259 span_err!(self.session,
1262 "the name `{}` conflicts with an external crate that has been imported \
1268 /// Resolves the given module path from the given root `module_`.
1269 fn resolve_module_path_from_root(&mut self,
1270 module_: Rc<Module>,
1271 module_path: &[Name],
1274 name_search_type: NameSearchType,
1276 -> ResolveResult<(Rc<Module>, LastPrivate)> {
1277 fn search_parent_externals(needle: Name, module: &Rc<Module>) -> Option<Rc<Module>> {
1278 match module.external_module_children.borrow().get(&needle) {
1279 Some(_) => Some(module.clone()),
1280 None => match module.parent_link {
1281 ModuleParentLink(ref parent, _) => {
1282 search_parent_externals(needle, &parent.upgrade().unwrap())
1289 let mut search_module = module_;
1290 let mut index = index;
1291 let module_path_len = module_path.len();
1292 let mut closest_private = lp;
1294 // Resolve the module part of the path. This does not involve looking
1295 // upward though scope chains; we simply resolve names directly in
1296 // modules as we go.
1297 while index < module_path_len {
1298 let name = module_path[index];
1299 match self.resolve_name_in_module(search_module.clone(),
1305 let segment_name = name.as_str();
1306 let module_name = module_to_string(&*search_module);
1307 let mut span = span;
1308 let msg = if "???" == &module_name[..] {
1309 span.hi = span.lo + Pos::from_usize(segment_name.len());
1311 match search_parent_externals(name, &self.current_module) {
1313 let path_str = names_to_string(module_path);
1314 let target_mod_str = module_to_string(&*module);
1315 let current_mod_str = module_to_string(&*self.current_module);
1317 let prefix = if target_mod_str == current_mod_str {
1318 "self::".to_string()
1320 format!("{}::", target_mod_str)
1323 format!("Did you mean `{}{}`?", prefix, path_str)
1325 None => format!("Maybe a missing `extern crate {}`?", segment_name),
1328 format!("Could not find `{}` in `{}`", segment_name, module_name)
1331 return Failed(Some((span, msg)));
1333 Failed(err) => return Failed(err),
1335 debug!("(resolving module path for import) module resolution is \
1338 return Indeterminate;
1340 Success((target, used_proxy)) => {
1341 // Check to see whether there are type bindings, and, if
1342 // so, whether there is a module within.
1343 if let Some(module_def) = target.binding.module() {
1344 // track extern crates for unused_extern_crate lint
1345 if let Some(did) = module_def.def_id() {
1346 self.used_crates.insert(did.krate);
1349 search_module = module_def;
1351 // Keep track of the closest private module used
1352 // when resolving this import chain.
1353 if !used_proxy && !search_module.is_public {
1354 if let Some(did) = search_module.def_id() {
1355 closest_private = LastMod(DependsOn(did));
1359 let msg = format!("Not a module `{}`", name);
1360 return Failed(Some((span, msg)));
1368 return Success((search_module, closest_private));
1371 /// Attempts to resolve the module part of an import directive or path
1372 /// rooted at the given module.
1374 /// On success, returns the resolved module, and the closest *private*
1375 /// module found to the destination when resolving this path.
1376 fn resolve_module_path(&mut self,
1377 module_: Rc<Module>,
1378 module_path: &[Name],
1379 use_lexical_scope: UseLexicalScopeFlag,
1381 name_search_type: NameSearchType)
1382 -> ResolveResult<(Rc<Module>, LastPrivate)> {
1383 let module_path_len = module_path.len();
1384 assert!(module_path_len > 0);
1386 debug!("(resolving module path for import) processing `{}` rooted at `{}`",
1387 names_to_string(module_path),
1388 module_to_string(&*module_));
1390 // Resolve the module prefix, if any.
1391 let module_prefix_result = self.resolve_module_prefix(module_.clone(), module_path);
1396 match module_prefix_result {
1398 let mpath = names_to_string(module_path);
1399 let mpath = &mpath[..];
1400 match mpath.rfind(':') {
1402 let msg = format!("Could not find `{}` in `{}`",
1403 // idx +- 1 to account for the
1404 // colons on either side
1407 return Failed(Some((span, msg)));
1410 return Failed(None);
1414 Failed(err) => return Failed(err),
1416 debug!("(resolving module path for import) indeterminate; bailing");
1417 return Indeterminate;
1419 Success(NoPrefixFound) => {
1420 // There was no prefix, so we're considering the first element
1421 // of the path. How we handle this depends on whether we were
1422 // instructed to use lexical scope or not.
1423 match use_lexical_scope {
1424 DontUseLexicalScope => {
1425 // This is a crate-relative path. We will start the
1426 // resolution process at index zero.
1427 search_module = self.graph_root.clone();
1429 last_private = LastMod(AllPublic);
1431 UseLexicalScope => {
1432 // This is not a crate-relative path. We resolve the
1433 // first component of the path in the current lexical
1434 // scope and then proceed to resolve below that.
1435 match self.resolve_module_in_lexical_scope(module_, module_path[0]) {
1436 Failed(err) => return Failed(err),
1438 debug!("(resolving module path for import) indeterminate; bailing");
1439 return Indeterminate;
1441 Success(containing_module) => {
1442 search_module = containing_module;
1444 last_private = LastMod(AllPublic);
1450 Success(PrefixFound(ref containing_module, index)) => {
1451 search_module = containing_module.clone();
1452 start_index = index;
1453 last_private = LastMod(DependsOn(containing_module.def_id()
1458 self.resolve_module_path_from_root(search_module,
1466 /// Invariant: This must only be called during main resolution, not during
1467 /// import resolution.
1468 fn resolve_item_in_lexical_scope(&mut self,
1469 module_: Rc<Module>,
1471 namespace: Namespace,
1473 -> ResolveResult<(Target, bool)> {
1474 debug!("(resolving item in lexical scope) resolving `{}` in namespace {:?} in `{}`",
1477 module_to_string(&*module_));
1479 // The current module node is handled specially. First, check for
1480 // its immediate children.
1481 build_reduced_graph::populate_module_if_necessary(self, &module_);
1483 match module_.children.borrow().get(&name) {
1484 Some(name_bindings) if name_bindings[namespace].defined() => {
1485 debug!("top name bindings succeeded");
1486 return Success((Target::new(module_.clone(),
1487 name_bindings[namespace].clone(),
1492 // Not found; continue.
1496 // Now check for its import directives. We don't have to have resolved
1497 // all its imports in the usual way; this is because chains of
1498 // adjacent import statements are processed as though they mutated the
1500 if let Some(import_resolution) = module_.import_resolutions.borrow().get(&name) {
1501 match import_resolution[namespace].target.clone() {
1503 // Not found; continue.
1504 debug!("(resolving item in lexical scope) found import resolution, but not \
1509 debug!("(resolving item in lexical scope) using import resolution");
1510 // track used imports and extern crates as well
1511 let id = import_resolution[namespace].id;
1513 self.used_imports.insert((id, namespace));
1514 self.record_import_use(id, name);
1515 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id() {
1516 self.used_crates.insert(kid);
1519 return Success((target, false));
1524 // Search for external modules.
1525 if namespace == TypeNS {
1526 // FIXME (21114): In principle unclear `child` *has* to be lifted.
1527 let child = module_.external_module_children.borrow().get(&name).cloned();
1528 if let Some(module) = child {
1529 let name_binding = NameBinding::create_from_module(module);
1530 debug!("lower name bindings succeeded");
1531 return Success((Target::new(module_, name_binding, Shadowable::Never),
1536 // Finally, proceed up the scope chain looking for parent modules.
1537 let mut search_module = module_;
1539 // Go to the next parent.
1540 match search_module.parent_link.clone() {
1542 // No more parents. This module was unresolved.
1543 debug!("(resolving item in lexical scope) unresolved module");
1544 return Failed(None);
1546 ModuleParentLink(parent_module_node, _) => {
1547 if search_module.is_normal() {
1548 // We stop the search here.
1549 debug!("(resolving item in lexical scope) unresolved module: not \
1550 searching through module parents");
1551 return Failed(None);
1553 search_module = parent_module_node.upgrade().unwrap();
1556 BlockParentLink(ref parent_module_node, _) => {
1557 search_module = parent_module_node.upgrade().unwrap();
1561 // Resolve the name in the parent module.
1562 match self.resolve_name_in_module(search_module.clone(),
1567 Failed(Some((span, msg))) => {
1568 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
1570 Failed(None) => (), // Continue up the search chain.
1572 // We couldn't see through the higher scope because of an
1573 // unresolved import higher up. Bail.
1575 debug!("(resolving item in lexical scope) indeterminate higher scope; bailing");
1576 return Indeterminate;
1578 Success((target, used_reexport)) => {
1579 // We found the module.
1580 debug!("(resolving item in lexical scope) found name in module, done");
1581 return Success((target, used_reexport));
1587 /// Resolves a module name in the current lexical scope.
1588 fn resolve_module_in_lexical_scope(&mut self,
1589 module_: Rc<Module>,
1591 -> ResolveResult<Rc<Module>> {
1592 // If this module is an anonymous module, resolve the item in the
1593 // lexical scope. Otherwise, resolve the item from the crate root.
1594 let resolve_result = self.resolve_item_in_lexical_scope(module_, name, TypeNS, true);
1595 match resolve_result {
1596 Success((target, _)) => {
1597 if let Some(module_def) = target.binding.module() {
1598 return Success(module_def)
1600 debug!("!!! (resolving module in lexical scope) module \
1601 wasn't actually a module!");
1602 return Failed(None);
1606 debug!("(resolving module in lexical scope) indeterminate; bailing");
1607 return Indeterminate;
1610 debug!("(resolving module in lexical scope) failed to resolve");
1616 /// Returns the nearest normal module parent of the given module.
1617 fn get_nearest_normal_module_parent(&mut self, module_: Rc<Module>) -> Option<Rc<Module>> {
1618 let mut module_ = module_;
1620 match module_.parent_link.clone() {
1621 NoParentLink => return None,
1622 ModuleParentLink(new_module, _) |
1623 BlockParentLink(new_module, _) => {
1624 let new_module = new_module.upgrade().unwrap();
1625 if new_module.is_normal() {
1626 return Some(new_module);
1628 module_ = new_module;
1634 /// Returns the nearest normal module parent of the given module, or the
1635 /// module itself if it is a normal module.
1636 fn get_nearest_normal_module_parent_or_self(&mut self, module_: Rc<Module>) -> Rc<Module> {
1637 if module_.is_normal() {
1640 match self.get_nearest_normal_module_parent(module_.clone()) {
1642 Some(new_module) => new_module,
1646 /// Resolves a "module prefix". A module prefix is one or both of (a) `self::`;
1647 /// (b) some chain of `super::`.
1648 /// grammar: (SELF MOD_SEP ) ? (SUPER MOD_SEP) *
1649 fn resolve_module_prefix(&mut self,
1650 module_: Rc<Module>,
1651 module_path: &[Name])
1652 -> ResolveResult<ModulePrefixResult> {
1653 // Start at the current module if we see `self` or `super`, or at the
1654 // top of the crate otherwise.
1655 let mut i = match &*module_path[0].as_str() {
1658 _ => return Success(NoPrefixFound),
1660 let mut containing_module = self.get_nearest_normal_module_parent_or_self(module_);
1662 // Now loop through all the `super`s we find.
1663 while i < module_path.len() && "super" == module_path[i].as_str() {
1664 debug!("(resolving module prefix) resolving `super` at {}",
1665 module_to_string(&*containing_module));
1666 match self.get_nearest_normal_module_parent(containing_module) {
1667 None => return Failed(None),
1668 Some(new_module) => {
1669 containing_module = new_module;
1675 debug!("(resolving module prefix) finished resolving prefix at {}",
1676 module_to_string(&*containing_module));
1678 return Success(PrefixFound(containing_module, i));
1681 /// Attempts to resolve the supplied name in the given module for the
1682 /// given namespace. If successful, returns the target corresponding to
1685 /// The boolean returned on success is an indicator of whether this lookup
1686 /// passed through a public re-export proxy.
1687 fn resolve_name_in_module(&mut self,
1688 module_: Rc<Module>,
1690 namespace: Namespace,
1691 name_search_type: NameSearchType,
1692 allow_private_imports: bool)
1693 -> ResolveResult<(Target, bool)> {
1694 debug!("(resolving name in module) resolving `{}` in `{}`",
1696 module_to_string(&*module_));
1698 // First, check the direct children of the module.
1699 build_reduced_graph::populate_module_if_necessary(self, &module_);
1701 match module_.children.borrow().get(&name) {
1702 Some(name_bindings) if name_bindings[namespace].defined() => {
1703 debug!("(resolving name in module) found node as child");
1704 return Success((Target::new(module_.clone(),
1705 name_bindings[namespace].clone(),
1714 // Next, check the module's imports if necessary.
1716 // If this is a search of all imports, we should be done with glob
1717 // resolution at this point.
1718 if name_search_type == PathSearch {
1719 assert_eq!(module_.glob_count.get(), 0);
1722 // Check the list of resolved imports.
1723 match module_.import_resolutions.borrow().get(&name) {
1724 Some(import_resolution) if allow_private_imports ||
1725 import_resolution[namespace].is_public => {
1727 if import_resolution[namespace].is_public &&
1728 import_resolution.outstanding_references != 0 {
1729 debug!("(resolving name in module) import unresolved; bailing out");
1730 return Indeterminate;
1732 match import_resolution[namespace].target.clone() {
1734 debug!("(resolving name in module) name found, but not in namespace {:?}",
1738 debug!("(resolving name in module) resolved to import");
1739 // track used imports and extern crates as well
1740 let id = import_resolution[namespace].id;
1741 self.used_imports.insert((id, namespace));
1742 self.record_import_use(id, name);
1743 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id() {
1744 self.used_crates.insert(kid);
1746 return Success((target, true));
1750 Some(..) | None => {} // Continue.
1753 // Finally, search through external children.
1754 if namespace == TypeNS {
1755 // FIXME (21114): In principle unclear `child` *has* to be lifted.
1756 let child = module_.external_module_children.borrow().get(&name).cloned();
1757 if let Some(module) = child {
1758 let name_binding = NameBinding::create_from_module(module);
1759 return Success((Target::new(module_, name_binding, Shadowable::Never),
1764 // We're out of luck.
1765 debug!("(resolving name in module) failed to resolve `{}`", name);
1766 return Failed(None);
1769 fn report_unresolved_imports(&mut self, module_: Rc<Module>) {
1770 let index = module_.resolved_import_count.get();
1771 let imports = module_.imports.borrow();
1772 let import_count = imports.len();
1773 if index != import_count {
1775 (*imports)[index].span,
1776 ResolutionError::UnresolvedImport(None));
1779 // Descend into children and anonymous children.
1780 build_reduced_graph::populate_module_if_necessary(self, &module_);
1782 for (_, child_node) in module_.children.borrow().iter() {
1783 match child_node.type_ns.module() {
1787 Some(child_module) => {
1788 self.report_unresolved_imports(child_module);
1793 for (_, module_) in module_.anonymous_children.borrow().iter() {
1794 self.report_unresolved_imports(module_.clone());
1800 // We maintain a list of value ribs and type ribs.
1802 // Simultaneously, we keep track of the current position in the module
1803 // graph in the `current_module` pointer. When we go to resolve a name in
1804 // the value or type namespaces, we first look through all the ribs and
1805 // then query the module graph. When we resolve a name in the module
1806 // namespace, we can skip all the ribs (since nested modules are not
1807 // allowed within blocks in Rust) and jump straight to the current module
1810 // Named implementations are handled separately. When we find a method
1811 // call, we consult the module node to find all of the implementations in
1812 // scope. This information is lazily cached in the module node. We then
1813 // generate a fake "implementation scope" containing all the
1814 // implementations thus found, for compatibility with old resolve pass.
1816 fn with_scope<F>(&mut self, name: Option<Name>, f: F)
1817 where F: FnOnce(&mut Resolver)
1819 let orig_module = self.current_module.clone();
1821 // Move down in the graph.
1827 build_reduced_graph::populate_module_if_necessary(self, &orig_module);
1829 match orig_module.children.borrow().get(&name) {
1831 debug!("!!! (with scope) didn't find `{}` in `{}`",
1833 module_to_string(&*orig_module));
1835 Some(name_bindings) => {
1836 match name_bindings.type_ns.module() {
1838 debug!("!!! (with scope) didn't find module for `{}` in `{}`",
1840 module_to_string(&*orig_module));
1843 self.current_module = module_;
1853 self.current_module = orig_module;
1856 /// Searches the current set of local scopes for labels.
1857 /// Stops after meeting a closure.
1858 fn search_label(&self, name: Name) -> Option<DefLike> {
1859 for rib in self.label_ribs.iter().rev() {
1865 // Do not resolve labels across function boundary
1869 let result = rib.bindings.get(&name).cloned();
1870 if result.is_some() {
1877 fn resolve_crate(&mut self, krate: &hir::Crate) {
1878 debug!("(resolving crate) starting");
1880 intravisit::walk_crate(self, krate);
1883 fn check_if_primitive_type_name(&self, name: Name, span: Span) {
1884 if let Some(_) = self.primitive_type_table.primitive_types.get(&name) {
1885 span_err!(self.session,
1888 "user-defined types or type parameters cannot shadow the primitive types");
1892 fn resolve_item(&mut self, item: &Item) {
1893 let name = item.name;
1895 debug!("(resolving item) resolving {}", name);
1898 ItemEnum(_, ref generics) |
1899 ItemTy(_, ref generics) |
1900 ItemStruct(_, ref generics) => {
1901 self.check_if_primitive_type_name(name, item.span);
1903 self.with_type_parameter_rib(HasTypeParameters(generics, TypeSpace, ItemRibKind),
1904 |this| intravisit::walk_item(this, item));
1906 ItemFn(_, _, _, _, ref generics, _) => {
1907 self.with_type_parameter_rib(HasTypeParameters(generics, FnSpace, ItemRibKind),
1908 |this| intravisit::walk_item(this, item));
1911 ItemDefaultImpl(_, ref trait_ref) => {
1912 self.with_optional_trait_ref(Some(trait_ref), |_, _| {});
1914 ItemImpl(_, _, ref generics, ref opt_trait_ref, ref self_type, ref impl_items) => {
1915 self.resolve_implementation(generics,
1922 ItemTrait(_, ref generics, ref bounds, ref trait_items) => {
1923 self.check_if_primitive_type_name(name, item.span);
1925 // Create a new rib for the trait-wide type parameters.
1926 self.with_type_parameter_rib(HasTypeParameters(generics,
1930 let local_def_id = this.ast_map.local_def_id(item.id);
1931 this.with_self_rib(DefSelfTy(Some(local_def_id), None), |this| {
1932 this.visit_generics(generics);
1933 walk_list!(this, visit_ty_param_bound, bounds);
1935 for trait_item in trait_items {
1936 match trait_item.node {
1937 hir::ConstTraitItem(_, ref default) => {
1938 // Only impose the restrictions of
1939 // ConstRibKind if there's an actual constant
1940 // expression in a provided default.
1941 if default.is_some() {
1942 this.with_constant_rib(|this| {
1943 intravisit::walk_trait_item(this, trait_item)
1946 intravisit::walk_trait_item(this, trait_item)
1949 hir::MethodTraitItem(ref sig, _) => {
1950 let type_parameters =
1951 HasTypeParameters(&sig.generics,
1954 this.with_type_parameter_rib(type_parameters, |this| {
1955 intravisit::walk_trait_item(this, trait_item)
1958 hir::TypeTraitItem(..) => {
1959 this.check_if_primitive_type_name(trait_item.name,
1961 this.with_type_parameter_rib(NoTypeParameters, |this| {
1962 intravisit::walk_trait_item(this, trait_item)
1971 ItemMod(_) | ItemForeignMod(_) => {
1972 self.with_scope(Some(name), |this| {
1973 intravisit::walk_item(this, item);
1977 ItemConst(..) | ItemStatic(..) => {
1978 self.with_constant_rib(|this| {
1979 intravisit::walk_item(this, item);
1983 ItemUse(ref view_path) => {
1984 // check for imports shadowing primitive types
1985 let check_rename = |this: &Self, id, name| {
1986 match this.def_map.borrow().get(&id).map(|d| d.full_def()) {
1987 Some(DefTy(..)) | Some(DefStruct(..)) | Some(DefTrait(..)) | None => {
1988 this.check_if_primitive_type_name(name, item.span);
1994 match view_path.node {
1995 hir::ViewPathSimple(name, _) => {
1996 check_rename(self, item.id, name);
1998 hir::ViewPathList(ref prefix, ref items) => {
2000 if let Some(name) = item.node.rename() {
2001 check_rename(self, item.node.id(), name);
2005 // Resolve prefix of an import with empty braces (issue #28388)
2006 if items.is_empty() && !prefix.segments.is_empty() {
2007 match self.resolve_crate_relative_path(prefix.span,
2011 self.record_def(item.id, PathResolution::new(def, lp, 0)),
2015 ResolutionError::FailedToResolve(
2016 &path_names_to_string(prefix, 0)));
2017 self.record_def(item.id, err_path_resolution());
2026 ItemExternCrate(_) => {
2027 // do nothing, these are just around to be encoded
2032 fn with_type_parameter_rib<F>(&mut self, type_parameters: TypeParameters, f: F)
2033 where F: FnOnce(&mut Resolver)
2035 match type_parameters {
2036 HasTypeParameters(generics, space, rib_kind) => {
2037 let mut function_type_rib = Rib::new(rib_kind);
2038 let mut seen_bindings = HashSet::new();
2039 for (index, type_parameter) in generics.ty_params.iter().enumerate() {
2040 let name = type_parameter.name;
2041 debug!("with_type_parameter_rib: {}", type_parameter.id);
2043 if seen_bindings.contains(&name) {
2045 type_parameter.span,
2046 ResolutionError::NameAlreadyUsedInTypeParameterList(name));
2048 seen_bindings.insert(name);
2050 // plain insert (no renaming)
2051 function_type_rib.bindings
2053 DlDef(DefTyParam(space,
2056 .local_def_id(type_parameter.id),
2059 self.type_ribs.push(function_type_rib);
2062 NoTypeParameters => {
2069 match type_parameters {
2070 HasTypeParameters(..) => {
2072 self.type_ribs.pop();
2075 NoTypeParameters => {}
2079 fn with_label_rib<F>(&mut self, f: F)
2080 where F: FnOnce(&mut Resolver)
2082 self.label_ribs.push(Rib::new(NormalRibKind));
2085 self.label_ribs.pop();
2089 fn with_constant_rib<F>(&mut self, f: F)
2090 where F: FnOnce(&mut Resolver)
2092 self.value_ribs.push(Rib::new(ConstantItemRibKind));
2093 self.type_ribs.push(Rib::new(ConstantItemRibKind));
2096 self.type_ribs.pop();
2097 self.value_ribs.pop();
2101 fn resolve_function(&mut self, rib_kind: RibKind, declaration: &FnDecl, block: &Block) {
2102 // Create a value rib for the function.
2103 self.value_ribs.push(Rib::new(rib_kind));
2105 // Create a label rib for the function.
2106 self.label_ribs.push(Rib::new(rib_kind));
2108 // Add each argument to the rib.
2109 let mut bindings_list = HashMap::new();
2110 for argument in &declaration.inputs {
2111 self.resolve_pattern(&*argument.pat, ArgumentIrrefutableMode, &mut bindings_list);
2113 self.visit_ty(&*argument.ty);
2115 debug!("(resolving function) recorded argument");
2117 intravisit::walk_fn_ret_ty(self, &declaration.output);
2119 // Resolve the function body.
2120 self.visit_block(block);
2122 debug!("(resolving function) leaving function");
2125 self.label_ribs.pop();
2126 self.value_ribs.pop();
2130 fn resolve_trait_reference(&mut self,
2134 -> Result<PathResolution, ()> {
2135 if let Some(path_res) = self.resolve_path(id, trait_path, path_depth, TypeNS, true) {
2136 if let DefTrait(_) = path_res.base_def {
2137 debug!("(resolving trait) found trait def: {:?}", path_res);
2142 ResolutionError::IsNotATrait(&*path_names_to_string(trait_path,
2145 // If it's a typedef, give a note
2146 if let DefTy(..) = path_res.base_def {
2148 .span_note(trait_path.span, "`type` aliases cannot be used for traits");
2155 ResolutionError::UndeclaredTraitName(&*path_names_to_string(trait_path,
2161 fn resolve_generics(&mut self, generics: &Generics) {
2162 for type_parameter in generics.ty_params.iter() {
2163 self.check_if_primitive_type_name(type_parameter.name, type_parameter.span);
2165 for predicate in &generics.where_clause.predicates {
2167 &hir::WherePredicate::BoundPredicate(_) |
2168 &hir::WherePredicate::RegionPredicate(_) => {}
2169 &hir::WherePredicate::EqPredicate(ref eq_pred) => {
2170 let path_res = self.resolve_path(eq_pred.id, &eq_pred.path, 0, TypeNS, true);
2171 if let Some(PathResolution { base_def: DefTyParam(..), .. }) = path_res {
2172 self.record_def(eq_pred.id, path_res.unwrap());
2176 ResolutionError::UndeclaredAssociatedType);
2177 self.record_def(eq_pred.id, err_path_resolution());
2182 intravisit::walk_generics(self, generics);
2185 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2186 where F: FnOnce(&mut Resolver) -> T
2188 // Handle nested impls (inside fn bodies)
2189 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2190 let result = f(self);
2191 self.current_self_type = previous_value;
2195 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
2196 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2198 let mut new_val = None;
2199 let mut new_id = None;
2200 if let Some(trait_ref) = opt_trait_ref {
2201 if let Ok(path_res) = self.resolve_trait_reference(trait_ref.ref_id,
2204 assert!(path_res.depth == 0);
2205 self.record_def(trait_ref.ref_id, path_res);
2206 new_val = Some((path_res.base_def.def_id(), trait_ref.clone()));
2207 new_id = Some(path_res.base_def.def_id());
2209 self.record_def(trait_ref.ref_id, err_path_resolution());
2211 intravisit::walk_trait_ref(self, trait_ref);
2213 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2214 let result = f(self, new_id);
2215 self.current_trait_ref = original_trait_ref;
2219 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2220 where F: FnOnce(&mut Resolver)
2222 let mut self_type_rib = Rib::new(NormalRibKind);
2224 // plain insert (no renaming, types are not currently hygienic....)
2225 let name = special_names::type_self;
2226 self_type_rib.bindings.insert(name, DlDef(self_def));
2227 self.type_ribs.push(self_type_rib);
2230 self.type_ribs.pop();
2234 fn resolve_implementation(&mut self,
2235 generics: &Generics,
2236 opt_trait_reference: &Option<TraitRef>,
2239 impl_items: &[ImplItem]) {
2240 // If applicable, create a rib for the type parameters.
2241 self.with_type_parameter_rib(HasTypeParameters(generics,
2245 // Resolve the type parameters.
2246 this.visit_generics(generics);
2248 // Resolve the trait reference, if necessary.
2249 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2250 // Resolve the self type.
2251 this.visit_ty(self_type);
2253 this.with_self_rib(DefSelfTy(trait_id, Some((item_id, self_type.id))), |this| {
2254 this.with_current_self_type(self_type, |this| {
2255 for impl_item in impl_items {
2256 match impl_item.node {
2257 hir::ImplItemKind::Const(..) => {
2258 // If this is a trait impl, ensure the const
2260 this.check_trait_item(impl_item.name,
2262 |n, s| ResolutionError::ConstNotMemberOfTrait(n, s));
2263 this.with_constant_rib(|this| {
2264 intravisit::walk_impl_item(this, impl_item);
2267 hir::ImplItemKind::Method(ref sig, _) => {
2268 // If this is a trait impl, ensure the method
2270 this.check_trait_item(impl_item.name,
2272 |n, s| ResolutionError::MethodNotMemberOfTrait(n, s));
2274 // We also need a new scope for the method-
2275 // specific type parameters.
2276 let type_parameters =
2277 HasTypeParameters(&sig.generics,
2280 this.with_type_parameter_rib(type_parameters, |this| {
2281 intravisit::walk_impl_item(this, impl_item);
2284 hir::ImplItemKind::Type(ref ty) => {
2285 // If this is a trait impl, ensure the type
2287 this.check_trait_item(impl_item.name,
2289 |n, s| ResolutionError::TypeNotMemberOfTrait(n, s));
2301 fn check_trait_item<F>(&self, name: Name, span: Span, err: F)
2302 where F: FnOnce(Name, &str) -> ResolutionError
2304 // If there is a TraitRef in scope for an impl, then the method must be in the
2306 if let Some((did, ref trait_ref)) = self.current_trait_ref {
2307 if !self.trait_item_map.contains_key(&(name, did)) {
2308 let path_str = path_names_to_string(&trait_ref.path, 0);
2309 resolve_error(self, span, err(name, &*path_str));
2314 fn resolve_local(&mut self, local: &Local) {
2315 // Resolve the type.
2316 walk_list!(self, visit_ty, &local.ty);
2318 // Resolve the initializer.
2319 walk_list!(self, visit_expr, &local.init);
2321 // Resolve the pattern.
2322 self.resolve_pattern(&*local.pat, LocalIrrefutableMode, &mut HashMap::new());
2325 // build a map from pattern identifiers to binding-info's.
2326 // this is done hygienically. This could arise for a macro
2327 // that expands into an or-pattern where one 'x' was from the
2328 // user and one 'x' came from the macro.
2329 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2330 let mut result = HashMap::new();
2331 pat_bindings(&self.def_map, pat, |binding_mode, _id, sp, path1| {
2332 let name = path1.node;
2336 binding_mode: binding_mode,
2342 // check that all of the arms in an or-pattern have exactly the
2343 // same set of bindings, with the same binding modes for each.
2344 fn check_consistent_bindings(&mut self, arm: &Arm) {
2345 if arm.pats.is_empty() {
2348 let map_0 = self.binding_mode_map(&*arm.pats[0]);
2349 for (i, p) in arm.pats.iter().enumerate() {
2350 let map_i = self.binding_mode_map(&**p);
2352 for (&key, &binding_0) in &map_0 {
2353 match map_i.get(&key) {
2357 ResolutionError::VariableNotBoundInPattern(key, i + 1));
2359 Some(binding_i) => {
2360 if binding_0.binding_mode != binding_i.binding_mode {
2363 ResolutionError::VariableBoundWithDifferentMode(key,
2370 for (&key, &binding) in &map_i {
2371 if !map_0.contains_key(&key) {
2374 ResolutionError::VariableNotBoundInParentPattern(key, i + 1));
2380 fn resolve_arm(&mut self, arm: &Arm) {
2381 self.value_ribs.push(Rib::new(NormalRibKind));
2383 let mut bindings_list = HashMap::new();
2384 for pattern in &arm.pats {
2385 self.resolve_pattern(&**pattern, RefutableMode, &mut bindings_list);
2388 // This has to happen *after* we determine which
2389 // pat_idents are variants
2390 self.check_consistent_bindings(arm);
2392 walk_list!(self, visit_expr, &arm.guard);
2393 self.visit_expr(&*arm.body);
2396 self.value_ribs.pop();
2400 fn resolve_block(&mut self, block: &Block) {
2401 debug!("(resolving block) entering block");
2402 self.value_ribs.push(Rib::new(NormalRibKind));
2404 // Move down in the graph, if there's an anonymous module rooted here.
2405 let orig_module = self.current_module.clone();
2406 match orig_module.anonymous_children.borrow().get(&block.id) {
2410 Some(anonymous_module) => {
2411 debug!("(resolving block) found anonymous module, moving down");
2412 self.current_module = anonymous_module.clone();
2416 // Check for imports appearing after non-item statements.
2417 let mut found_non_item = false;
2418 for statement in &block.stmts {
2419 if let hir::StmtDecl(ref declaration, _) = statement.node {
2420 if let hir::DeclItem(i) = declaration.node {
2421 let i = self.ast_map.expect_item(i.id);
2423 ItemExternCrate(_) | ItemUse(_) if found_non_item => {
2424 span_err!(self.session,
2427 "imports are not allowed after non-item statements");
2432 found_non_item = true
2435 found_non_item = true;
2439 // Descend into the block.
2440 intravisit::walk_block(self, block);
2444 self.current_module = orig_module;
2445 self.value_ribs.pop();
2447 debug!("(resolving block) leaving block");
2450 fn resolve_type(&mut self, ty: &Ty) {
2452 TyPath(ref maybe_qself, ref path) => {
2453 let resolution = match self.resolve_possibly_assoc_item(ty.id,
2454 maybe_qself.as_ref(),
2458 // `<T>::a::b::c` is resolved by typeck alone.
2459 TypecheckRequired => {
2460 // Resolve embedded types.
2461 intravisit::walk_ty(self, ty);
2464 ResolveAttempt(resolution) => resolution,
2467 // This is a path in the type namespace. Walk through scopes
2471 // Write the result into the def map.
2472 debug!("(resolving type) writing resolution for `{}` (id {}) = {:?}",
2473 path_names_to_string(path, 0),
2476 self.record_def(ty.id, def);
2479 self.record_def(ty.id, err_path_resolution());
2481 // Keep reporting some errors even if they're ignored above.
2482 self.resolve_path(ty.id, path, 0, TypeNS, true);
2484 let kind = if maybe_qself.is_some() {
2490 let self_type_name = special_idents::type_self.name;
2491 let is_invalid_self_type_name = path.segments.len() > 0 &&
2492 maybe_qself.is_none() &&
2493 path.segments[0].identifier.name ==
2495 if is_invalid_self_type_name {
2498 ResolutionError::SelfUsedOutsideImplOrTrait);
2502 ResolutionError::UseOfUndeclared(
2504 &*path_names_to_string(path,
2513 // Resolve embedded types.
2514 intravisit::walk_ty(self, ty);
2517 fn resolve_pattern(&mut self,
2519 mode: PatternBindingMode,
2520 // Maps idents to the node ID for the (outermost)
2521 // pattern that binds them
2522 bindings_list: &mut HashMap<Name, NodeId>) {
2523 let pat_id = pattern.id;
2524 walk_pat(pattern, |pattern| {
2525 match pattern.node {
2526 PatIdent(binding_mode, ref path1, ref at_rhs) => {
2527 // The meaning of PatIdent with no type parameters
2528 // depends on whether an enum variant or unit-like struct
2529 // with that name is in scope. The probing lookup has to
2530 // be careful not to emit spurious errors. Only matching
2531 // patterns (match) can match nullary variants or
2532 // unit-like structs. For binding patterns (let
2533 // and the LHS of @-patterns), matching such a value is
2534 // simply disallowed (since it's rarely what you want).
2535 let const_ok = mode == RefutableMode && at_rhs.is_none();
2537 let ident = path1.node;
2538 let renamed = ident.name;
2540 match self.resolve_bare_identifier_pattern(ident.unhygienic_name,
2542 FoundStructOrEnumVariant(def, lp) if const_ok => {
2543 debug!("(resolving pattern) resolving `{}` to struct or enum variant",
2546 self.enforce_default_binding_mode(pattern,
2549 self.record_def(pattern.id,
2556 FoundStructOrEnumVariant(..) => {
2560 ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(
2563 self.record_def(pattern.id, err_path_resolution());
2565 FoundConst(def, lp, _) if const_ok => {
2566 debug!("(resolving pattern) resolving `{}` to constant", renamed);
2568 self.enforce_default_binding_mode(pattern, binding_mode, "a constant");
2569 self.record_def(pattern.id,
2576 FoundConst(def, _, name) => {
2580 ResolutionError::OnlyIrrefutablePatternsAllowedHere(def.def_id(),
2583 self.record_def(pattern.id, err_path_resolution());
2585 BareIdentifierPatternUnresolved => {
2586 debug!("(resolving pattern) binding `{}`", renamed);
2588 let def_id = self.ast_map.local_def_id(pattern.id);
2589 let def = DefLocal(def_id, pattern.id);
2591 // Record the definition so that later passes
2592 // will be able to distinguish variants from
2593 // locals in patterns.
2595 self.record_def(pattern.id,
2598 last_private: LastMod(AllPublic),
2602 // Add the binding to the local ribs, if it
2603 // doesn't already exist in the bindings list. (We
2604 // must not add it if it's in the bindings list
2605 // because that breaks the assumptions later
2606 // passes make about or-patterns.)
2607 if !bindings_list.contains_key(&renamed) {
2608 let this = &mut *self;
2609 let last_rib = this.value_ribs.last_mut().unwrap();
2610 last_rib.bindings.insert(renamed, DlDef(def));
2611 bindings_list.insert(renamed, pat_id);
2612 } else if mode == ArgumentIrrefutableMode &&
2613 bindings_list.contains_key(&renamed) {
2614 // Forbid duplicate bindings in the same
2619 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2620 &ident.name.as_str())
2622 } else if bindings_list.get(&renamed) == Some(&pat_id) {
2623 // Then this is a duplicate variable in the
2624 // same disjunction, which is an error.
2628 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2629 &ident.name.as_str())
2632 // Else, not bound in the same pattern: do
2638 PatEnum(ref path, _) => {
2639 // This must be an enum variant, struct or const.
2640 let resolution = match self.resolve_possibly_assoc_item(pat_id,
2645 // The below shouldn't happen because all
2646 // qualified paths should be in PatQPath.
2647 TypecheckRequired =>
2648 self.session.span_bug(path.span,
2649 "resolve_possibly_assoc_item claimed
2651 that a path in PatEnum requires typecheck
2653 to resolve, but qualified paths should be
2656 ResolveAttempt(resolution) => resolution,
2658 if let Some(path_res) = resolution {
2659 match path_res.base_def {
2660 DefVariant(..) | DefStruct(..) | DefConst(..) => {
2661 self.record_def(pattern.id, path_res);
2664 resolve_error(&self,
2666 ResolutionError::StaticVariableReference);
2667 self.record_def(pattern.id, err_path_resolution());
2670 // If anything ends up here entirely resolved,
2671 // it's an error. If anything ends up here
2672 // partially resolved, that's OK, because it may
2673 // be a `T::CONST` that typeck will resolve.
2674 if path_res.depth == 0 {
2678 ResolutionError::NotAnEnumVariantStructOrConst(
2686 self.record_def(pattern.id, err_path_resolution());
2688 let const_name = path.segments
2693 let traits = self.get_traits_containing_item(const_name);
2694 self.trait_map.insert(pattern.id, traits);
2695 self.record_def(pattern.id, path_res);
2703 ResolutionError::UnresolvedEnumVariantStructOrConst(
2704 &path.segments.last().unwrap().identifier.name.as_str())
2706 self.record_def(pattern.id, err_path_resolution());
2708 intravisit::walk_path(self, path);
2711 PatQPath(ref qself, ref path) => {
2712 // Associated constants only.
2713 let resolution = match self.resolve_possibly_assoc_item(pat_id,
2718 TypecheckRequired => {
2719 // All `<T>::CONST` should end up here, and will
2720 // require use of the trait map to resolve
2721 // during typechecking.
2722 let const_name = path.segments
2727 let traits = self.get_traits_containing_item(const_name);
2728 self.trait_map.insert(pattern.id, traits);
2729 intravisit::walk_pat(self, pattern);
2732 ResolveAttempt(resolution) => resolution,
2734 if let Some(path_res) = resolution {
2735 match path_res.base_def {
2736 // All `<T as Trait>::CONST` should end up here, and
2737 // have the trait already selected.
2738 DefAssociatedConst(..) => {
2739 self.record_def(pattern.id, path_res);
2745 ResolutionError::NotAnAssociatedConst(
2746 &path.segments.last().unwrap().identifier.name.as_str()
2749 self.record_def(pattern.id, err_path_resolution());
2755 ResolutionError::UnresolvedAssociatedConst(&path.segments
2761 self.record_def(pattern.id, err_path_resolution());
2763 intravisit::walk_pat(self, pattern);
2766 PatStruct(ref path, _, _) => {
2767 match self.resolve_path(pat_id, path, 0, TypeNS, false) {
2768 Some(definition) => {
2769 self.record_def(pattern.id, definition);
2772 debug!("(resolving pattern) didn't find struct def: {:?}", result);
2776 ResolutionError::DoesNotNameAStruct(
2777 &*path_names_to_string(path, 0))
2779 self.record_def(pattern.id, err_path_resolution());
2782 intravisit::walk_path(self, path);
2785 PatLit(_) | PatRange(..) => {
2786 intravisit::walk_pat(self, pattern);
2797 fn resolve_bare_identifier_pattern(&mut self,
2800 -> BareIdentifierPatternResolution {
2801 let module = self.current_module.clone();
2802 match self.resolve_item_in_lexical_scope(module, name, ValueNS, true) {
2803 Success((target, _)) => {
2804 debug!("(resolve bare identifier pattern) succeeded in finding {} at {:?}",
2806 target.binding.borrow());
2807 match target.binding.def() {
2809 panic!("resolved name in the value namespace to a set of name bindings \
2812 // For the two success cases, this lookup can be
2813 // considered as not having a private component because
2814 // the lookup happened only within the current module.
2815 Some(def @ DefVariant(..)) | Some(def @ DefStruct(..)) => {
2816 return FoundStructOrEnumVariant(def, LastMod(AllPublic));
2818 Some(def @ DefConst(..)) | Some(def @ DefAssociatedConst(..)) => {
2819 return FoundConst(def, LastMod(AllPublic), name);
2821 Some(DefStatic(..)) => {
2822 resolve_error(self, span, ResolutionError::StaticVariableReference);
2823 return BareIdentifierPatternUnresolved;
2825 _ => return BareIdentifierPatternUnresolved
2830 panic!("unexpected indeterminate result");
2834 Some((span, msg)) => {
2835 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
2840 debug!("(resolve bare identifier pattern) failed to find {}", name);
2841 return BareIdentifierPatternUnresolved;
2846 /// Handles paths that may refer to associated items
2847 fn resolve_possibly_assoc_item(&mut self,
2849 maybe_qself: Option<&hir::QSelf>,
2851 namespace: Namespace,
2853 -> AssocItemResolveResult {
2854 let max_assoc_types;
2858 if qself.position == 0 {
2859 return TypecheckRequired;
2861 max_assoc_types = path.segments.len() - qself.position;
2862 // Make sure the trait is valid.
2863 let _ = self.resolve_trait_reference(id, path, max_assoc_types);
2866 max_assoc_types = path.segments.len();
2870 let mut resolution = self.with_no_errors(|this| {
2871 this.resolve_path(id, path, 0, namespace, check_ribs)
2873 for depth in 1..max_assoc_types {
2874 if resolution.is_some() {
2877 self.with_no_errors(|this| {
2878 resolution = this.resolve_path(id, path, depth, TypeNS, true);
2881 if let Some(DefMod(_)) = resolution.map(|r| r.base_def) {
2882 // A module is not a valid type or value.
2885 ResolveAttempt(resolution)
2888 /// If `check_ribs` is true, checks the local definitions first; i.e.
2889 /// doesn't skip straight to the containing module.
2890 /// Skips `path_depth` trailing segments, which is also reflected in the
2891 /// returned value. See `middle::def::PathResolution` for more info.
2892 pub fn resolve_path(&mut self,
2896 namespace: Namespace,
2898 -> Option<PathResolution> {
2899 let span = path.span;
2900 let segments = &path.segments[..path.segments.len() - path_depth];
2902 let mk_res = |(def, lp)| PathResolution::new(def, lp, path_depth);
2905 let def = self.resolve_crate_relative_path(span, segments, namespace);
2906 return def.map(mk_res);
2909 // Try to find a path to an item in a module.
2910 let last_ident = segments.last().unwrap().identifier;
2911 if segments.len() <= 1 {
2912 let unqualified_def = self.resolve_identifier(last_ident, namespace, check_ribs, true);
2913 return unqualified_def.and_then(|def| self.adjust_local_def(def, span))
2915 PathResolution::new(def, LastMod(AllPublic), path_depth)
2919 let unqualified_def = self.resolve_identifier(last_ident, namespace, check_ribs, false);
2920 let def = self.resolve_module_relative_path(span, segments, namespace);
2921 match (def, unqualified_def) {
2922 (Some((ref d, _)), Some(ref ud)) if *d == ud.def => {
2924 .add_lint(lint::builtin::UNUSED_QUALIFICATIONS,
2927 "unnecessary qualification".to_string());
2935 // Resolve a single identifier
2936 fn resolve_identifier(&mut self,
2937 identifier: hir::Ident,
2938 namespace: Namespace,
2941 -> Option<LocalDef> {
2942 // First, check to see whether the name is a primitive type.
2943 if namespace == TypeNS {
2944 if let Some(&prim_ty) = self.primitive_type_table
2946 .get(&identifier.unhygienic_name) {
2947 return Some(LocalDef::from_def(DefPrimTy(prim_ty)));
2952 if let Some(def) = self.resolve_identifier_in_local_ribs(identifier, namespace) {
2957 let name = identifier.unhygienic_name;
2958 self.resolve_item_by_name_in_lexical_scope(name, namespace, record_used)
2959 .map(LocalDef::from_def)
2962 // Resolve a local definition, potentially adjusting for closures.
2963 fn adjust_local_def(&mut self, local_def: LocalDef, span: Span) -> Option<Def> {
2964 let ribs = match local_def.ribs {
2965 Some((TypeNS, i)) => &self.type_ribs[i + 1..],
2966 Some((ValueNS, i)) => &self.value_ribs[i + 1..],
2969 let mut def = local_def.def;
2972 self.session.span_bug(span, &format!("unexpected {:?} in bindings", def))
2974 DefLocal(_, node_id) => {
2978 // Nothing to do. Continue.
2980 ClosureRibKind(function_id) => {
2982 let node_def_id = self.ast_map.local_def_id(node_id);
2984 let seen = self.freevars_seen
2986 .or_insert_with(|| NodeMap());
2987 if let Some(&index) = seen.get(&node_id) {
2988 def = DefUpvar(node_def_id, node_id, index, function_id);
2991 let vec = self.freevars
2993 .or_insert_with(|| vec![]);
2994 let depth = vec.len();
3000 def = DefUpvar(node_def_id, node_id, depth, function_id);
3001 seen.insert(node_id, depth);
3003 ItemRibKind | MethodRibKind => {
3004 // This was an attempt to access an upvar inside a
3005 // named function item. This is not allowed, so we
3009 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
3012 ConstantItemRibKind => {
3013 // Still doesn't deal with upvars
3016 ResolutionError::AttemptToUseNonConstantValueInConstant);
3022 DefTyParam(..) | DefSelfTy(..) => {
3025 NormalRibKind | MethodRibKind | ClosureRibKind(..) => {
3026 // Nothing to do. Continue.
3029 // This was an attempt to use a type parameter outside
3034 ResolutionError::TypeParametersFromOuterFunction);
3037 ConstantItemRibKind => {
3039 resolve_error(self, span, ResolutionError::OuterTypeParameterContext);
3050 // resolve a "module-relative" path, e.g. a::b::c
3051 fn resolve_module_relative_path(&mut self,
3053 segments: &[hir::PathSegment],
3054 namespace: Namespace)
3055 -> Option<(Def, LastPrivate)> {
3056 let module_path = segments.split_last()
3060 .map(|ps| ps.identifier.name)
3061 .collect::<Vec<_>>();
3063 let containing_module;
3065 let current_module = self.current_module.clone();
3066 match self.resolve_module_path(current_module,
3072 let (span, msg) = match err {
3073 Some((span, msg)) => (span, msg),
3075 let msg = format!("Use of undeclared type or module `{}`",
3076 names_to_string(&module_path));
3081 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3084 Indeterminate => panic!("indeterminate unexpected"),
3085 Success((resulting_module, resulting_last_private)) => {
3086 containing_module = resulting_module;
3087 last_private = resulting_last_private;
3091 let name = segments.last().unwrap().identifier.name;
3092 let def = match self.resolve_name_in_module(containing_module.clone(),
3095 NameSearchType::PathSearch,
3097 Success((Target { binding, .. }, _)) => {
3098 let (def, lp) = binding.def_and_lp();
3099 (def, last_private.or(lp))
3103 if let Some(DefId{krate: kid, ..}) = containing_module.def_id() {
3104 self.used_crates.insert(kid);
3109 /// Invariant: This must be called only during main resolution, not during
3110 /// import resolution.
3111 fn resolve_crate_relative_path(&mut self,
3113 segments: &[hir::PathSegment],
3114 namespace: Namespace)
3115 -> Option<(Def, LastPrivate)> {
3116 let module_path = segments.split_last()
3120 .map(|ps| ps.identifier.name)
3121 .collect::<Vec<_>>();
3123 let root_module = self.graph_root.clone();
3125 let containing_module;
3127 match self.resolve_module_path_from_root(root_module,
3132 LastMod(AllPublic)) {
3134 let (span, msg) = match err {
3135 Some((span, msg)) => (span, msg),
3137 let msg = format!("Use of undeclared module `::{}`",
3138 names_to_string(&module_path[..]));
3143 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3148 panic!("indeterminate unexpected");
3151 Success((resulting_module, resulting_last_private)) => {
3152 containing_module = resulting_module;
3153 last_private = resulting_last_private;
3157 let name = segments.last().unwrap().identifier.name;
3158 match self.resolve_name_in_module(containing_module,
3161 NameSearchType::PathSearch,
3163 Success((Target { binding, .. }, _)) => {
3164 let (def, lp) = binding.def_and_lp();
3165 Some((def, last_private.or(lp)))
3171 fn resolve_identifier_in_local_ribs(&mut self,
3173 namespace: Namespace)
3174 -> Option<LocalDef> {
3175 // Check the local set of ribs.
3176 let (name, ribs) = match namespace {
3177 ValueNS => (ident.name, &self.value_ribs),
3178 TypeNS => (ident.unhygienic_name, &self.type_ribs),
3181 for (i, rib) in ribs.iter().enumerate().rev() {
3182 if let Some(def_like) = rib.bindings.get(&name).cloned() {
3185 debug!("(resolving path in local ribs) resolved `{}` to {:?} at {}",
3189 return Some(LocalDef {
3190 ribs: Some((namespace, i)),
3195 debug!("(resolving path in local ribs) resolved `{}` to pseudo-def {:?}",
3207 fn resolve_item_by_name_in_lexical_scope(&mut self,
3209 namespace: Namespace,
3213 let module = self.current_module.clone();
3214 match self.resolve_item_in_lexical_scope(module, name, namespace, record_used) {
3215 Success((target, _)) => {
3216 match target.binding.def() {
3218 // This can happen if we were looking for a type and
3219 // found a module instead. Modules don't have defs.
3220 debug!("(resolving item path by identifier in lexical scope) failed to \
3221 resolve {} after success...",
3226 debug!("(resolving item path in lexical scope) resolved `{}` to item",
3228 // This lookup is "all public" because it only searched
3229 // for one identifier in the current module (couldn't
3230 // have passed through reexports or anything like that.
3236 panic!("unexpected indeterminate result");
3239 debug!("(resolving item path by identifier in lexical scope) failed to resolve {}",
3242 if let Some((span, msg)) = err {
3243 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg))
3251 fn with_no_errors<T, F>(&mut self, f: F) -> T
3252 where F: FnOnce(&mut Resolver) -> T
3254 self.emit_errors = false;
3256 self.emit_errors = true;
3260 fn find_fallback_in_self_type(&mut self, name: Name) -> FallbackSuggestion {
3261 fn extract_path_and_node_id(t: &Ty,
3262 allow: FallbackChecks)
3263 -> Option<(Path, NodeId, FallbackChecks)> {
3265 TyPath(None, ref path) => Some((path.clone(), t.id, allow)),
3266 TyPtr(ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, OnlyTraitAndStatics),
3267 TyRptr(_, ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, allow),
3268 // This doesn't handle the remaining `Ty` variants as they are not
3269 // that commonly the self_type, it might be interesting to provide
3270 // support for those in future.
3275 fn get_module(this: &mut Resolver,
3277 name_path: &[ast::Name])
3278 -> Option<Rc<Module>> {
3279 let root = this.current_module.clone();
3280 let last_name = name_path.last().unwrap();
3282 if name_path.len() == 1 {
3283 match this.primitive_type_table.primitive_types.get(last_name) {
3286 match this.current_module.children.borrow().get(last_name) {
3287 Some(child) => child.type_ns.module(),
3293 match this.resolve_module_path(root,
3298 Success((module, _)) => Some(module),
3304 fn is_static_method(this: &Resolver, did: DefId) -> bool {
3305 if let Some(node_id) = this.ast_map.as_local_node_id(did) {
3306 let sig = match this.ast_map.get(node_id) {
3307 hir_map::NodeTraitItem(trait_item) => match trait_item.node {
3308 hir::MethodTraitItem(ref sig, _) => sig,
3311 hir_map::NodeImplItem(impl_item) => match impl_item.node {
3312 hir::ImplItemKind::Method(ref sig, _) => sig,
3317 sig.explicit_self.node == hir::SelfStatic
3319 this.session.cstore.is_static_method(did)
3323 let (path, node_id, allowed) = match self.current_self_type {
3324 Some(ref ty) => match extract_path_and_node_id(ty, Everything) {
3326 None => return NoSuggestion,
3328 None => return NoSuggestion,
3331 if allowed == Everything {
3332 // Look for a field with the same name in the current self_type.
3333 match self.def_map.borrow().get(&node_id).map(|d| d.full_def()) {
3334 Some(DefTy(did, _)) |
3335 Some(DefStruct(did)) |
3336 Some(DefVariant(_, did, _)) => match self.structs.get(&did) {
3339 if fields.iter().any(|&field_name| name == field_name) {
3344 _ => {} // Self type didn't resolve properly
3348 let name_path = path.segments.iter().map(|seg| seg.identifier.name).collect::<Vec<_>>();
3350 // Look for a method in the current self type's impl module.
3351 if let Some(module) = get_module(self, path.span, &name_path) {
3352 if let Some(binding) = module.children.borrow().get(&name) {
3353 if let Some(DefMethod(did)) = binding.value_ns.def() {
3354 if is_static_method(self, did) {
3355 return StaticMethod(path_names_to_string(&path, 0));
3357 if self.current_trait_ref.is_some() {
3359 } else if allowed == Everything {
3366 // Look for a method in the current trait.
3367 if let Some((trait_did, ref trait_ref)) = self.current_trait_ref {
3368 if let Some(&did) = self.trait_item_map.get(&(name, trait_did)) {
3369 if is_static_method(self, did) {
3370 return TraitMethod(path_names_to_string(&trait_ref.path, 0));
3380 fn find_best_match_for_name(&mut self, name: &str) -> SuggestionType {
3381 let mut maybes: Vec<token::InternedString> = Vec::new();
3382 let mut values: Vec<usize> = Vec::new();
3384 if let Some(macro_name) = self.session.available_macros
3385 .borrow().iter().find(|n| n.as_str() == name) {
3386 return SuggestionType::Macro(format!("{}!", macro_name));
3389 for rib in self.value_ribs.iter().rev() {
3390 for (&k, _) in &rib.bindings {
3391 maybes.push(k.as_str());
3392 values.push(usize::MAX);
3396 let mut smallest = 0;
3397 for (i, other) in maybes.iter().enumerate() {
3398 values[i] = lev_distance(name, &other);
3400 if values[i] <= values[smallest] {
3405 let max_distance = max_suggestion_distance(name);
3406 if !values.is_empty() && values[smallest] <= max_distance && name != &maybes[smallest][..] {
3408 SuggestionType::Function(maybes[smallest].to_string())
3411 SuggestionType::NotFound
3415 fn resolve_expr(&mut self, expr: &Expr) {
3416 // First, record candidate traits for this expression if it could
3417 // result in the invocation of a method call.
3419 self.record_candidate_traits_for_expr_if_necessary(expr);
3421 // Next, resolve the node.
3423 ExprPath(ref maybe_qself, ref path) => {
3424 let resolution = match self.resolve_possibly_assoc_item(expr.id,
3425 maybe_qself.as_ref(),
3429 // `<T>::a::b::c` is resolved by typeck alone.
3430 TypecheckRequired => {
3431 let method_name = path.segments.last().unwrap().identifier.name;
3432 let traits = self.get_traits_containing_item(method_name);
3433 self.trait_map.insert(expr.id, traits);
3434 intravisit::walk_expr(self, expr);
3437 ResolveAttempt(resolution) => resolution,
3440 // This is a local path in the value namespace. Walk through
3441 // scopes looking for it.
3442 if let Some(path_res) = resolution {
3443 // Check if struct variant
3444 if let DefVariant(_, _, true) = path_res.base_def {
3445 let path_name = path_names_to_string(path, 0);
3449 ResolutionError::StructVariantUsedAsFunction(&*path_name));
3451 let msg = format!("did you mean to write: `{} {{ /* fields */ }}`?",
3453 if self.emit_errors {
3454 self.session.fileline_help(expr.span, &msg);
3456 self.session.span_help(expr.span, &msg);
3458 self.record_def(expr.id, err_path_resolution());
3460 // Write the result into the def map.
3461 debug!("(resolving expr) resolved `{}`",
3462 path_names_to_string(path, 0));
3464 // Partial resolutions will need the set of traits in scope,
3465 // so they can be completed during typeck.
3466 if path_res.depth != 0 {
3467 let method_name = path.segments.last().unwrap().identifier.name;
3468 let traits = self.get_traits_containing_item(method_name);
3469 self.trait_map.insert(expr.id, traits);
3472 self.record_def(expr.id, path_res);
3475 // Be helpful if the name refers to a struct
3476 // (The pattern matching def_tys where the id is in self.structs
3477 // matches on regular structs while excluding tuple- and enum-like
3478 // structs, which wouldn't result in this error.)
3479 let path_name = path_names_to_string(path, 0);
3480 let type_res = self.with_no_errors(|this| {
3481 this.resolve_path(expr.id, path, 0, TypeNS, false)
3484 self.record_def(expr.id, err_path_resolution());
3485 match type_res.map(|r| r.base_def) {
3486 Some(DefTy(struct_id, _)) if self.structs.contains_key(&struct_id) => {
3490 ResolutionError::StructVariantUsedAsFunction(
3494 let msg = format!("did you mean to write: `{} {{ /* fields */ }}`?",
3496 if self.emit_errors {
3497 self.session.fileline_help(expr.span, &msg);
3499 self.session.span_help(expr.span, &msg);
3503 // Keep reporting some errors even if they're ignored above.
3504 self.resolve_path(expr.id, path, 0, ValueNS, true);
3506 let mut method_scope = false;
3507 self.value_ribs.iter().rev().all(|rib| {
3508 method_scope = match rib.kind {
3509 MethodRibKind => true,
3510 ItemRibKind | ConstantItemRibKind => false,
3511 _ => return true, // Keep advancing
3513 false // Stop advancing
3516 if method_scope && special_names::self_.as_str() == &path_name[..] {
3519 ResolutionError::SelfNotAvailableInStaticMethod);
3521 let last_name = path.segments.last().unwrap().identifier.name;
3522 let mut msg = match self.find_fallback_in_self_type(last_name) {
3524 // limit search to 5 to reduce the number
3525 // of stupid suggestions
3526 match self.find_best_match_for_name(&path_name) {
3527 SuggestionType::Macro(s) => {
3528 format!("the macro `{}`", s)
3530 SuggestionType::Function(s) => format!("`{}`", s),
3531 SuggestionType::NotFound => "".to_string(),
3534 Field => format!("`self.{}`", path_name),
3536 TraitItem => format!("to call `self.{}`", path_name),
3537 TraitMethod(path_str) |
3538 StaticMethod(path_str) =>
3539 format!("to call `{}::{}`", path_str, path_name),
3542 if !msg.is_empty() {
3543 msg = format!(". Did you mean {}?", msg)
3548 ResolutionError::UnresolvedName(&*path_name, &*msg));
3554 intravisit::walk_expr(self, expr);
3557 ExprStruct(ref path, _, _) => {
3558 // Resolve the path to the structure it goes to. We don't
3559 // check to ensure that the path is actually a structure; that
3560 // is checked later during typeck.
3561 match self.resolve_path(expr.id, path, 0, TypeNS, false) {
3562 Some(definition) => self.record_def(expr.id, definition),
3564 debug!("(resolving expression) didn't find struct def",);
3568 ResolutionError::DoesNotNameAStruct(
3569 &*path_names_to_string(path, 0))
3571 self.record_def(expr.id, err_path_resolution());
3575 intravisit::walk_expr(self, expr);
3578 ExprLoop(_, Some(label)) | ExprWhile(_, _, Some(label)) => {
3579 self.with_label_rib(|this| {
3580 let def_like = DlDef(DefLabel(expr.id));
3583 let rib = this.label_ribs.last_mut().unwrap();
3584 rib.bindings.insert(label.name, def_like);
3587 intravisit::walk_expr(this, expr);
3591 ExprBreak(Some(label)) | ExprAgain(Some(label)) => {
3592 match self.search_label(label.node.name) {
3594 self.record_def(expr.id, err_path_resolution());
3597 ResolutionError::UndeclaredLabel(&label.node.name.as_str()))
3599 Some(DlDef(def @ DefLabel(_))) => {
3600 // Since this def is a label, it is never read.
3601 self.record_def(expr.id,
3604 last_private: LastMod(AllPublic),
3609 self.session.span_bug(expr.span, "label wasn't mapped to a label def!")
3615 intravisit::walk_expr(self, expr);
3620 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3622 ExprField(_, name) => {
3623 // FIXME(#6890): Even though you can't treat a method like a
3624 // field, we need to add any trait methods we find that match
3625 // the field name so that we can do some nice error reporting
3626 // later on in typeck.
3627 let traits = self.get_traits_containing_item(name.node);
3628 self.trait_map.insert(expr.id, traits);
3630 ExprMethodCall(name, _, _) => {
3631 debug!("(recording candidate traits for expr) recording traits for {}",
3633 let traits = self.get_traits_containing_item(name.node);
3634 self.trait_map.insert(expr.id, traits);
3642 fn get_traits_containing_item(&mut self, name: Name) -> Vec<DefId> {
3643 debug!("(getting traits containing item) looking for '{}'", name);
3645 fn add_trait_info(found_traits: &mut Vec<DefId>, trait_def_id: DefId, name: Name) {
3646 debug!("(adding trait info) found trait {:?} for method '{}'",
3649 found_traits.push(trait_def_id);
3652 let mut found_traits = Vec::new();
3653 let mut search_module = self.current_module.clone();
3655 // Look for the current trait.
3656 match self.current_trait_ref {
3657 Some((trait_def_id, _)) => {
3658 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3659 add_trait_info(&mut found_traits, trait_def_id, name);
3662 None => {} // Nothing to do.
3665 // Look for trait children.
3666 build_reduced_graph::populate_module_if_necessary(self, &search_module);
3669 for (_, child_names) in search_module.children.borrow().iter() {
3670 let def = match child_names.type_ns.def() {
3674 let trait_def_id = match def {
3675 DefTrait(trait_def_id) => trait_def_id,
3678 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3679 add_trait_info(&mut found_traits, trait_def_id, name);
3684 // Look for imports.
3685 for (_, import) in search_module.import_resolutions.borrow().iter() {
3686 let target = match import.type_ns.target {
3688 Some(ref target) => target,
3690 let did = match target.binding.def() {
3691 Some(DefTrait(trait_def_id)) => trait_def_id,
3692 Some(..) | None => continue,
3694 if self.trait_item_map.contains_key(&(name, did)) {
3695 add_trait_info(&mut found_traits, did, name);
3696 let id = import.type_ns.id;
3697 self.used_imports.insert((id, TypeNS));
3698 let trait_name = self.get_trait_name(did);
3699 self.record_import_use(id, trait_name);
3700 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id() {
3701 self.used_crates.insert(kid);
3706 match search_module.parent_link.clone() {
3707 NoParentLink | ModuleParentLink(..) => break,
3708 BlockParentLink(parent_module, _) => {
3709 search_module = parent_module.upgrade().unwrap();
3717 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
3718 debug!("(recording def) recording {:?} for {}", resolution, node_id);
3719 assert!(match resolution.last_private {
3720 LastImport{..} => false,
3723 "Import should only be used for `use` directives");
3725 if let Some(prev_res) = self.def_map.borrow_mut().insert(node_id, resolution) {
3726 let span = self.ast_map.opt_span(node_id).unwrap_or(codemap::DUMMY_SP);
3727 self.session.span_bug(span,
3728 &format!("path resolved multiple times ({:?} before, {:?} now)",
3734 fn enforce_default_binding_mode(&mut self,
3736 pat_binding_mode: BindingMode,
3738 match pat_binding_mode {
3739 BindByValue(_) => {}
3743 ResolutionError::CannotUseRefBindingModeWith(descr));
3751 // Diagnostics are not particularly efficient, because they're rarely
3755 #[allow(dead_code)] // useful for debugging
3756 fn dump_module(&mut self, module_: Rc<Module>) {
3757 debug!("Dump of module `{}`:", module_to_string(&*module_));
3759 debug!("Children:");
3760 build_reduced_graph::populate_module_if_necessary(self, &module_);
3761 for (&name, _) in module_.children.borrow().iter() {
3762 debug!("* {}", name);
3765 debug!("Import resolutions:");
3766 let import_resolutions = module_.import_resolutions.borrow();
3767 for (&name, import_resolution) in import_resolutions.iter() {
3769 match import_resolution.value_ns.target {
3771 value_repr = "".to_string();
3774 value_repr = " value:?".to_string();
3780 match import_resolution.type_ns.target {
3782 type_repr = "".to_string();
3785 type_repr = " type:?".to_string();
3790 debug!("* {}:{}{}", name, value_repr, type_repr);
3796 fn names_to_string(names: &[Name]) -> String {
3797 let mut first = true;
3798 let mut result = String::new();
3803 result.push_str("::")
3805 result.push_str(&name.as_str());
3810 fn path_names_to_string(path: &Path, depth: usize) -> String {
3811 let names: Vec<ast::Name> = path.segments[..path.segments.len() - depth]
3813 .map(|seg| seg.identifier.name)
3815 names_to_string(&names[..])
3818 /// A somewhat inefficient routine to obtain the name of a module.
3819 fn module_to_string(module: &Module) -> String {
3820 let mut names = Vec::new();
3822 fn collect_mod(names: &mut Vec<ast::Name>, module: &Module) {
3823 match module.parent_link {
3825 ModuleParentLink(ref module, name) => {
3827 collect_mod(names, &*module.upgrade().unwrap());
3829 BlockParentLink(ref module, _) => {
3830 // danger, shouldn't be ident?
3831 names.push(special_idents::opaque.name);
3832 collect_mod(names, &*module.upgrade().unwrap());
3836 collect_mod(&mut names, module);
3838 if names.is_empty() {
3839 return "???".to_string();
3841 names_to_string(&names.into_iter().rev().collect::<Vec<ast::Name>>())
3844 fn err_path_resolution() -> PathResolution {
3847 last_private: LastMod(AllPublic),
3853 pub struct CrateMap {
3854 pub def_map: RefCell<DefMap>,
3855 pub freevars: FreevarMap,
3856 pub export_map: ExportMap,
3857 pub trait_map: TraitMap,
3858 pub external_exports: ExternalExports,
3859 pub glob_map: Option<GlobMap>,
3862 #[derive(PartialEq,Copy, Clone)]
3863 pub enum MakeGlobMap {
3868 /// Entry point to crate resolution.
3869 pub fn resolve_crate<'a, 'tcx>(session: &'a Session,
3870 ast_map: &'a hir_map::Map<'tcx>,
3871 make_glob_map: MakeGlobMap)
3873 let krate = ast_map.krate();
3874 let mut resolver = create_resolver(session, ast_map, krate, make_glob_map, None);
3876 resolver.resolve_crate(krate);
3878 check_unused::check_crate(&mut resolver, krate);
3881 def_map: resolver.def_map,
3882 freevars: resolver.freevars,
3883 export_map: resolver.export_map,
3884 trait_map: resolver.trait_map,
3885 external_exports: resolver.external_exports,
3886 glob_map: if resolver.make_glob_map {
3887 Some(resolver.glob_map)
3894 /// Builds a name resolution walker to be used within this module,
3895 /// or used externally, with an optional callback function.
3897 /// The callback takes a &mut bool which allows callbacks to end a
3898 /// walk when set to true, passing through the rest of the walk, while
3899 /// preserving the ribs + current module. This allows resolve_path
3900 /// calls to be made with the correct scope info. The node in the
3901 /// callback corresponds to the current node in the walk.
3902 pub fn create_resolver<'a, 'tcx>(session: &'a Session,
3903 ast_map: &'a hir_map::Map<'tcx>,
3905 make_glob_map: MakeGlobMap,
3906 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>)
3907 -> Resolver<'a, 'tcx> {
3908 let mut resolver = Resolver::new(session, ast_map, make_glob_map);
3910 resolver.callback = callback;
3912 build_reduced_graph::build_reduced_graph(&mut resolver, krate);
3913 session.abort_if_errors();
3915 resolve_imports::resolve_imports(&mut resolver);
3916 session.abort_if_errors();
3918 record_exports::record(&mut resolver);
3919 session.abort_if_errors();
3924 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }