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 #![crate_name = "rustc_resolve"]
12 #![unstable(feature = "rustc_private", issue = "27812")]
13 #![crate_type = "dylib"]
14 #![crate_type = "rlib"]
15 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
16 html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
17 html_root_url = "https://doc.rust-lang.org/nightly/")]
19 #![feature(associated_consts)]
20 #![feature(borrow_state)]
21 #![feature(rustc_diagnostic_macros)]
22 #![feature(rustc_private)]
23 #![feature(staged_api)]
32 extern crate rustc_bitflags;
33 extern crate rustc_front;
36 use self::PatternBindingMode::*;
37 use self::Namespace::*;
38 use self::NamespaceResult::*;
39 use self::ResolveResult::*;
40 use self::FallbackSuggestion::*;
41 use self::TypeParameters::*;
43 use self::UseLexicalScopeFlag::*;
44 use self::ModulePrefixResult::*;
45 use self::AssocItemResolveResult::*;
46 use self::NameSearchType::*;
47 use self::BareIdentifierPatternResolution::*;
48 use self::ParentLink::*;
49 use self::FallbackChecks::*;
51 use rustc::front::map as hir_map;
52 use rustc::session::Session;
54 use rustc::middle::cstore::{CrateStore, DefLike, DlDef};
55 use rustc::middle::def::*;
56 use rustc::middle::def_id::DefId;
57 use rustc::middle::pat_util::pat_bindings;
58 use rustc::middle::privacy::*;
59 use rustc::middle::subst::{ParamSpace, FnSpace, TypeSpace};
60 use rustc::middle::ty::{Freevar, FreevarMap, TraitMap, GlobMap};
61 use rustc::util::nodemap::{NodeMap, DefIdSet, FnvHashMap};
64 use syntax::ast::{CRATE_NODE_ID, Name, NodeId, CrateNum, TyIs, TyI8, TyI16, TyI32, TyI64};
65 use syntax::ast::{TyUs, TyU8, TyU16, TyU32, TyU64, TyF64, TyF32};
66 use syntax::attr::AttrMetaMethods;
67 use syntax::codemap::{self, Span, Pos};
68 use syntax::errors::DiagnosticBuilder;
69 use syntax::parse::token::{self, special_names, special_idents};
70 use syntax::util::lev_distance::find_best_match_for_name;
72 use rustc_front::intravisit::{self, FnKind, Visitor};
74 use rustc_front::hir::{Arm, BindByRef, BindByValue, BindingMode, Block};
75 use rustc_front::hir::Crate;
76 use rustc_front::hir::{Expr, ExprAgain, ExprBreak, ExprCall, ExprField};
77 use rustc_front::hir::{ExprLoop, ExprWhile, ExprMethodCall};
78 use rustc_front::hir::{ExprPath, ExprStruct, FnDecl};
79 use rustc_front::hir::{ForeignItemFn, ForeignItemStatic, Generics};
80 use rustc_front::hir::{ImplItem, Item, ItemConst, ItemEnum, ItemExternCrate};
81 use rustc_front::hir::{ItemFn, ItemForeignMod, ItemImpl, ItemMod, ItemStatic, ItemDefaultImpl};
82 use rustc_front::hir::{ItemStruct, ItemTrait, ItemTy, ItemUse};
83 use rustc_front::hir::Local;
84 use rustc_front::hir::{Pat, PatEnum, PatIdent, PatLit, PatQPath};
85 use rustc_front::hir::{PatRange, PatStruct, Path, PrimTy};
86 use rustc_front::hir::{TraitRef, Ty, TyBool, TyChar, TyFloat, TyInt};
87 use rustc_front::hir::{TyRptr, TyStr, TyUint, TyPath, TyPtr};
88 use rustc_front::util::walk_pat;
90 use std::collections::{HashMap, HashSet};
91 use std::cell::{Cell, RefCell};
93 use std::mem::replace;
96 use resolve_imports::{Target, ImportDirective, ImportResolutionPerNamespace};
97 use resolve_imports::Shadowable;
99 // NB: This module needs to be declared first so diagnostics are
100 // registered before they are used.
104 mod build_reduced_graph;
107 // Perform the callback, not walking deeper if the return is true
108 macro_rules! execute_callback {
109 ($node: expr, $walker: expr) => (
110 if let Some(ref callback) = $walker.callback {
111 if callback($node, &mut $walker.resolved) {
118 enum SuggestionType {
120 Function(token::InternedString),
124 pub enum ResolutionError<'a> {
125 /// error E0260: name conflicts with an extern crate
126 NameConflictsWithExternCrate(Name),
127 /// error E0401: can't use type parameters from outer function
128 TypeParametersFromOuterFunction,
129 /// error E0402: cannot use an outer type parameter in this context
130 OuterTypeParameterContext,
131 /// error E0403: the name is already used for a type parameter in this type parameter list
132 NameAlreadyUsedInTypeParameterList(Name),
133 /// error E0404: is not a trait
134 IsNotATrait(&'a str),
135 /// error E0405: use of undeclared trait name
136 UndeclaredTraitName(&'a str),
137 /// error E0406: undeclared associated type
138 UndeclaredAssociatedType,
139 /// error E0407: method is not a member of trait
140 MethodNotMemberOfTrait(Name, &'a str),
141 /// error E0437: type is not a member of trait
142 TypeNotMemberOfTrait(Name, &'a str),
143 /// error E0438: const is not a member of trait
144 ConstNotMemberOfTrait(Name, &'a str),
145 /// error E0408: variable `{}` from pattern #1 is not bound in pattern
146 VariableNotBoundInPattern(Name, usize),
147 /// error E0409: variable is bound with different mode in pattern #{} than in pattern #1
148 VariableBoundWithDifferentMode(Name, usize),
149 /// error E0410: variable from pattern is not bound in pattern #1
150 VariableNotBoundInParentPattern(Name, usize),
151 /// error E0411: use of `Self` outside of an impl or trait
152 SelfUsedOutsideImplOrTrait,
153 /// error E0412: use of undeclared
154 UseOfUndeclared(&'a str, &'a str),
155 /// error E0413: declaration shadows an enum variant or unit-like struct in scope
156 DeclarationShadowsEnumVariantOrUnitLikeStruct(Name),
157 /// error E0414: only irrefutable patterns allowed here
158 OnlyIrrefutablePatternsAllowedHere(DefId, Name),
159 /// error E0415: identifier is bound more than once in this parameter list
160 IdentifierBoundMoreThanOnceInParameterList(&'a str),
161 /// error E0416: identifier is bound more than once in the same pattern
162 IdentifierBoundMoreThanOnceInSamePattern(&'a str),
163 /// error E0417: static variables cannot be referenced in a pattern
164 StaticVariableReference,
165 /// error E0418: is not an enum variant, struct or const
166 NotAnEnumVariantStructOrConst(&'a str),
167 /// error E0419: unresolved enum variant, struct or const
168 UnresolvedEnumVariantStructOrConst(&'a str),
169 /// error E0420: is not an associated const
170 NotAnAssociatedConst(&'a str),
171 /// error E0421: unresolved associated const
172 UnresolvedAssociatedConst(&'a str),
173 /// error E0422: does not name a struct
174 DoesNotNameAStruct(&'a str),
175 /// error E0423: is a struct variant name, but this expression uses it like a function name
176 StructVariantUsedAsFunction(&'a str),
177 /// error E0424: `self` is not available in a static method
178 SelfNotAvailableInStaticMethod,
179 /// error E0425: unresolved name
180 UnresolvedName(&'a str, &'a str, UnresolvedNameContext),
181 /// error E0426: use of undeclared label
182 UndeclaredLabel(&'a str),
183 /// error E0427: cannot use `ref` binding mode with ...
184 CannotUseRefBindingModeWith(&'a str),
185 /// error E0428: duplicate definition
186 DuplicateDefinition(&'a str, Name),
187 /// error E0429: `self` imports are only allowed within a { } list
188 SelfImportsOnlyAllowedWithin,
189 /// error E0430: `self` import can only appear once in the list
190 SelfImportCanOnlyAppearOnceInTheList,
191 /// error E0431: `self` import can only appear in an import list with a non-empty prefix
192 SelfImportOnlyInImportListWithNonEmptyPrefix,
193 /// error E0432: unresolved import
194 UnresolvedImport(Option<(&'a str, &'a str)>),
195 /// error E0433: failed to resolve
196 FailedToResolve(&'a str),
197 /// error E0434: can't capture dynamic environment in a fn item
198 CannotCaptureDynamicEnvironmentInFnItem,
199 /// error E0435: attempt to use a non-constant value in a constant
200 AttemptToUseNonConstantValueInConstant,
203 /// Context of where `ResolutionError::UnresolvedName` arose.
204 #[derive(Clone, PartialEq, Eq, Debug)]
205 pub enum UnresolvedNameContext {
206 /// `PathIsMod(id)` indicates that a given path, used in
207 /// expression context, actually resolved to a module rather than
208 /// a value. The `id` attached to the variant is the node id of
209 /// the erroneous path expression.
210 PathIsMod(ast::NodeId),
212 /// `Other` means we have no extra information about the context
213 /// of the unresolved name error. (Maybe we could eliminate all
214 /// such cases; but for now, this is an information-free default.)
218 fn resolve_error<'b, 'a: 'b, 'tcx: 'a>(resolver: &'b Resolver<'a, 'tcx>,
219 span: syntax::codemap::Span,
220 resolution_error: ResolutionError<'b>) {
221 resolve_struct_error(resolver, span, resolution_error).emit();
224 fn resolve_struct_error<'b, 'a: 'b, 'tcx: 'a>(resolver: &'b Resolver<'a, 'tcx>,
225 span: syntax::codemap::Span,
226 resolution_error: ResolutionError<'b>)
227 -> DiagnosticBuilder<'a> {
228 if !resolver.emit_errors {
229 return resolver.session.diagnostic().struct_dummy();
232 match resolution_error {
233 ResolutionError::NameConflictsWithExternCrate(name) => {
234 struct_span_err!(resolver.session,
237 "the name `{}` conflicts with an external crate \
238 that has been imported into this module",
241 ResolutionError::TypeParametersFromOuterFunction => {
242 struct_span_err!(resolver.session,
245 "can't use type parameters from outer function; try using a local \
246 type parameter instead")
248 ResolutionError::OuterTypeParameterContext => {
249 struct_span_err!(resolver.session,
252 "cannot use an outer type parameter in this context")
254 ResolutionError::NameAlreadyUsedInTypeParameterList(name) => {
255 struct_span_err!(resolver.session,
258 "the name `{}` is already used for a type parameter in this type \
262 ResolutionError::IsNotATrait(name) => {
263 struct_span_err!(resolver.session, span, E0404, "`{}` is not a trait", name)
265 ResolutionError::UndeclaredTraitName(name) => {
266 struct_span_err!(resolver.session,
269 "use of undeclared trait name `{}`",
272 ResolutionError::UndeclaredAssociatedType => {
273 struct_span_err!(resolver.session, span, E0406, "undeclared associated type")
275 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
276 struct_span_err!(resolver.session,
279 "method `{}` is not a member of trait `{}`",
283 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
284 struct_span_err!(resolver.session,
287 "type `{}` is not a member of trait `{}`",
291 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
292 struct_span_err!(resolver.session,
295 "const `{}` is not a member of trait `{}`",
299 ResolutionError::VariableNotBoundInPattern(variable_name, pattern_number) => {
300 struct_span_err!(resolver.session,
303 "variable `{}` from pattern #1 is not bound in pattern #{}",
307 ResolutionError::VariableBoundWithDifferentMode(variable_name, pattern_number) => {
308 struct_span_err!(resolver.session,
311 "variable `{}` is bound with different mode in pattern #{} than in \
316 ResolutionError::VariableNotBoundInParentPattern(variable_name, pattern_number) => {
317 struct_span_err!(resolver.session,
320 "variable `{}` from pattern #{} is not bound in pattern #1",
324 ResolutionError::SelfUsedOutsideImplOrTrait => {
325 struct_span_err!(resolver.session,
328 "use of `Self` outside of an impl or trait")
330 ResolutionError::UseOfUndeclared(kind, name) => {
331 struct_span_err!(resolver.session,
334 "use of undeclared {} `{}`",
338 ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(name) => {
339 struct_span_err!(resolver.session,
342 "declaration of `{}` shadows an enum variant \
343 or unit-like struct in scope",
346 ResolutionError::OnlyIrrefutablePatternsAllowedHere(did, name) => {
347 let mut err = struct_span_err!(resolver.session,
350 "only irrefutable patterns allowed here");
352 "there already is a constant in scope sharing the same \
353 name as this pattern");
354 if let Some(sp) = resolver.ast_map.span_if_local(did) {
355 err.span_note(sp, "constant defined here");
357 if let Some(directive) = resolver.current_module
361 let item = resolver.ast_map.expect_item(directive.value_ns.id);
362 err.span_note(item.span, "constant imported here");
366 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
367 struct_span_err!(resolver.session,
370 "identifier `{}` is bound more than once in this parameter list",
373 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
374 struct_span_err!(resolver.session,
377 "identifier `{}` is bound more than once in the same pattern",
380 ResolutionError::StaticVariableReference => {
381 struct_span_err!(resolver.session,
384 "static variables cannot be referenced in a pattern, use a \
387 ResolutionError::NotAnEnumVariantStructOrConst(name) => {
388 struct_span_err!(resolver.session,
391 "`{}` is not an enum variant, struct or const",
394 ResolutionError::UnresolvedEnumVariantStructOrConst(name) => {
395 struct_span_err!(resolver.session,
398 "unresolved enum variant, struct or const `{}`",
401 ResolutionError::NotAnAssociatedConst(name) => {
402 struct_span_err!(resolver.session,
405 "`{}` is not an associated const",
408 ResolutionError::UnresolvedAssociatedConst(name) => {
409 struct_span_err!(resolver.session,
412 "unresolved associated const `{}`",
415 ResolutionError::DoesNotNameAStruct(name) => {
416 struct_span_err!(resolver.session,
419 "`{}` does not name a structure",
422 ResolutionError::StructVariantUsedAsFunction(path_name) => {
423 struct_span_err!(resolver.session,
426 "`{}` is the name of a struct or struct variant, but this expression \
427 uses it like a function name",
430 ResolutionError::SelfNotAvailableInStaticMethod => {
431 struct_span_err!(resolver.session,
434 "`self` is not available in a static method. Maybe a `self` \
435 argument is missing?")
437 ResolutionError::UnresolvedName(path, msg, context) => {
438 let mut err = struct_span_err!(resolver.session,
441 "unresolved name `{}`{}",
446 UnresolvedNameContext::Other => { } // no help available
447 UnresolvedNameContext::PathIsMod(id) => {
448 let mut help_msg = String::new();
449 let parent_id = resolver.ast_map.get_parent_node(id);
450 if let Some(hir_map::Node::NodeExpr(e)) = resolver.ast_map.find(parent_id) {
452 ExprField(_, ident) => {
453 help_msg = format!("To reference an item from the \
454 `{module}` module, use \
455 `{module}::{ident}`",
459 ExprMethodCall(ident, _, _) => {
460 help_msg = format!("To call a function from the \
461 `{module}` module, use \
462 `{module}::{ident}(..)`",
467 help_msg = format!("No function corresponds to `{module}(..)`",
470 _ => { } // no help available
473 help_msg = format!("Module `{module}` cannot be the value of an expression",
477 if !help_msg.is_empty() {
478 err.fileline_help(span, &help_msg);
484 ResolutionError::UndeclaredLabel(name) => {
485 struct_span_err!(resolver.session,
488 "use of undeclared label `{}`",
491 ResolutionError::CannotUseRefBindingModeWith(descr) => {
492 struct_span_err!(resolver.session,
495 "cannot use `ref` binding mode with {}",
498 ResolutionError::DuplicateDefinition(namespace, name) => {
499 struct_span_err!(resolver.session,
502 "duplicate definition of {} `{}`",
506 ResolutionError::SelfImportsOnlyAllowedWithin => {
507 struct_span_err!(resolver.session,
511 "`self` imports are only allowed within a { } list")
513 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
514 struct_span_err!(resolver.session,
517 "`self` import can only appear once in the list")
519 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
520 struct_span_err!(resolver.session,
523 "`self` import can only appear in an import list with a \
526 ResolutionError::UnresolvedImport(name) => {
527 let msg = match name {
528 Some((n, p)) => format!("unresolved import `{}`{}", n, p),
529 None => "unresolved import".to_owned(),
531 struct_span_err!(resolver.session, span, E0432, "{}", msg)
533 ResolutionError::FailedToResolve(msg) => {
534 struct_span_err!(resolver.session, span, E0433, "failed to resolve. {}", msg)
536 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
537 struct_span_err!(resolver.session,
541 "can't capture dynamic environment in a fn item; use the || { ... } \
542 closure form instead")
544 ResolutionError::AttemptToUseNonConstantValueInConstant => {
545 struct_span_err!(resolver.session,
548 "attempt to use a non-constant value in a constant")
553 #[derive(Copy, Clone)]
556 binding_mode: BindingMode,
559 // Map from the name in a pattern to its binding mode.
560 type BindingMap = HashMap<Name, BindingInfo>;
562 #[derive(Copy, Clone, PartialEq)]
563 enum PatternBindingMode {
565 LocalIrrefutableMode,
566 ArgumentIrrefutableMode,
569 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
575 /// A NamespaceResult represents the result of resolving an import in
576 /// a particular namespace. The result is either definitely-resolved,
577 /// definitely- unresolved, or unknown.
579 enum NamespaceResult<'a> {
580 /// Means that resolve hasn't gathered enough information yet to determine
581 /// whether the name is bound in this namespace. (That is, it hasn't
582 /// resolved all `use` directives yet.)
584 /// Means that resolve has determined that the name is definitely
585 /// not bound in the namespace.
587 /// Means that resolve has determined that the name is bound in the Module
588 /// argument, and specified by the NameBinding argument.
589 BoundResult(Module<'a>, NameBinding<'a>),
592 impl<'a> NamespaceResult<'a> {
593 fn is_unknown(&self) -> bool {
595 UnknownResult => true,
599 fn is_unbound(&self) -> bool {
601 UnboundResult => true,
607 impl<'a, 'v, 'tcx> Visitor<'v> for Resolver<'a, 'tcx> {
608 fn visit_nested_item(&mut self, item: hir::ItemId) {
609 self.visit_item(self.ast_map.expect_item(item.id))
611 fn visit_item(&mut self, item: &Item) {
612 execute_callback!(hir_map::Node::NodeItem(item), self);
613 self.resolve_item(item);
615 fn visit_arm(&mut self, arm: &Arm) {
616 self.resolve_arm(arm);
618 fn visit_block(&mut self, block: &Block) {
619 execute_callback!(hir_map::Node::NodeBlock(block), self);
620 self.resolve_block(block);
622 fn visit_expr(&mut self, expr: &Expr) {
623 execute_callback!(hir_map::Node::NodeExpr(expr), self);
624 self.resolve_expr(expr);
626 fn visit_local(&mut self, local: &Local) {
627 execute_callback!(hir_map::Node::NodeLocal(&*local.pat), self);
628 self.resolve_local(local);
630 fn visit_ty(&mut self, ty: &Ty) {
631 self.resolve_type(ty);
633 fn visit_generics(&mut self, generics: &Generics) {
634 self.resolve_generics(generics);
636 fn visit_poly_trait_ref(&mut self, tref: &hir::PolyTraitRef, m: &hir::TraitBoundModifier) {
637 match self.resolve_trait_reference(tref.trait_ref.ref_id, &tref.trait_ref.path, 0) {
638 Ok(def) => self.record_def(tref.trait_ref.ref_id, def),
640 // error already reported
641 self.record_def(tref.trait_ref.ref_id, err_path_resolution())
644 intravisit::walk_poly_trait_ref(self, tref, m);
646 fn visit_variant(&mut self,
647 variant: &hir::Variant,
649 item_id: ast::NodeId) {
650 execute_callback!(hir_map::Node::NodeVariant(variant), self);
651 if let Some(ref dis_expr) = variant.node.disr_expr {
652 // resolve the discriminator expr as a constant
653 self.with_constant_rib(|this| {
654 this.visit_expr(dis_expr);
658 // `intravisit::walk_variant` without the discriminant expression.
659 self.visit_variant_data(&variant.node.data,
665 fn visit_foreign_item(&mut self, foreign_item: &hir::ForeignItem) {
666 execute_callback!(hir_map::Node::NodeForeignItem(foreign_item), self);
667 let type_parameters = match foreign_item.node {
668 ForeignItemFn(_, ref generics) => {
669 HasTypeParameters(generics, FnSpace, ItemRibKind)
671 ForeignItemStatic(..) => NoTypeParameters,
673 self.with_type_parameter_rib(type_parameters, |this| {
674 intravisit::walk_foreign_item(this, foreign_item);
677 fn visit_fn(&mut self,
678 function_kind: FnKind<'v>,
679 declaration: &'v FnDecl,
683 let rib_kind = match function_kind {
684 FnKind::ItemFn(_, generics, _, _, _, _) => {
685 self.visit_generics(generics);
688 FnKind::Method(_, sig, _) => {
689 self.visit_generics(&sig.generics);
690 self.visit_explicit_self(&sig.explicit_self);
693 FnKind::Closure => ClosureRibKind(node_id),
695 self.resolve_function(rib_kind, declaration, block);
699 type ErrorMessage = Option<(Span, String)>;
701 enum ResolveResult<T> {
702 Failed(ErrorMessage), // Failed to resolve the name, optional helpful error message.
703 Indeterminate, // Couldn't determine due to unresolved globs.
704 Success(T), // Successfully resolved the import.
707 impl<T> ResolveResult<T> {
708 fn success(&self) -> bool {
716 enum FallbackSuggestion {
721 StaticMethod(String),
725 #[derive(Copy, Clone)]
726 enum TypeParameters<'a> {
728 HasTypeParameters(// Type parameters.
731 // Identifies the things that these parameters
732 // were declared on (type, fn, etc)
735 // The kind of the rib used for type parameters.
739 // The rib kind controls the translation of local
740 // definitions (`Def::Local`) to upvars (`Def::Upvar`).
741 #[derive(Copy, Clone, Debug)]
743 // No translation needs to be applied.
746 // We passed through a closure scope at the given node ID.
747 // Translate upvars as appropriate.
748 ClosureRibKind(NodeId /* func id */),
750 // We passed through an impl or trait and are now in one of its
751 // methods. Allow references to ty params that impl or trait
752 // binds. Disallow any other upvars (including other ty params that are
756 // We passed through an item scope. Disallow upvars.
759 // We're in a constant item. Can't refer to dynamic stuff.
763 #[derive(Copy, Clone)]
764 enum UseLexicalScopeFlag {
769 enum ModulePrefixResult<'a> {
771 PrefixFound(Module<'a>, usize),
774 #[derive(Copy, Clone)]
775 enum AssocItemResolveResult {
776 /// Syntax such as `<T>::item`, which can't be resolved until type
779 /// We should have been able to resolve the associated item.
780 ResolveAttempt(Option<PathResolution>),
783 #[derive(Copy, Clone, PartialEq)]
784 enum NameSearchType {
785 /// We're doing a name search in order to resolve a `use` directive.
788 /// We're doing a name search in order to resolve a path type, a path
789 /// expression, or a path pattern.
793 #[derive(Copy, Clone)]
794 enum BareIdentifierPatternResolution {
795 FoundStructOrEnumVariant(Def, LastPrivate),
796 FoundConst(Def, LastPrivate, Name),
797 BareIdentifierPatternUnresolved,
803 bindings: HashMap<Name, DefLike>,
808 fn new(kind: RibKind) -> Rib {
810 bindings: HashMap::new(),
816 /// A definition along with the index of the rib it was found on
818 ribs: Option<(Namespace, usize)>,
823 fn from_def(def: Def) -> Self {
831 /// The link from a module up to its nearest parent node.
832 #[derive(Clone,Debug)]
833 enum ParentLink<'a> {
835 ModuleParentLink(Module<'a>, Name),
836 BlockParentLink(Module<'a>, NodeId),
839 /// One node in the tree of modules.
840 pub struct ModuleS<'a> {
841 parent_link: ParentLink<'a>,
842 def: Cell<Option<Def>>,
845 children: RefCell<HashMap<Name, NameBindings<'a>>>,
846 imports: RefCell<Vec<ImportDirective>>,
848 // The external module children of this node that were declared with
850 external_module_children: RefCell<HashMap<Name, Module<'a>>>,
852 // The anonymous children of this node. Anonymous children are pseudo-
853 // modules that are implicitly created around items contained within
856 // For example, if we have this:
864 // There will be an anonymous module created around `g` with the ID of the
865 // entry block for `f`.
866 anonymous_children: RefCell<NodeMap<Module<'a>>>,
868 // The status of resolving each import in this module.
869 import_resolutions: RefCell<HashMap<Name, ImportResolutionPerNamespace<'a>>>,
871 // The number of unresolved globs that this module exports.
872 glob_count: Cell<usize>,
874 // The number of unresolved pub imports (both regular and globs) in this module
875 pub_count: Cell<usize>,
877 // The number of unresolved pub glob imports in this module
878 pub_glob_count: Cell<usize>,
880 // The index of the import we're resolving.
881 resolved_import_count: Cell<usize>,
883 // Whether this module is populated. If not populated, any attempt to
884 // access the children must be preceded with a
885 // `populate_module_if_necessary` call.
886 populated: Cell<bool>,
889 pub type Module<'a> = &'a ModuleS<'a>;
891 impl<'a> ModuleS<'a> {
892 fn new(parent_link: ParentLink<'a>, def: Option<Def>, external: bool, is_public: bool) -> Self {
894 parent_link: parent_link,
896 is_public: is_public,
897 children: RefCell::new(HashMap::new()),
898 imports: RefCell::new(Vec::new()),
899 external_module_children: RefCell::new(HashMap::new()),
900 anonymous_children: RefCell::new(NodeMap()),
901 import_resolutions: RefCell::new(HashMap::new()),
902 glob_count: Cell::new(0),
903 pub_count: Cell::new(0),
904 pub_glob_count: Cell::new(0),
905 resolved_import_count: Cell::new(0),
906 populated: Cell::new(!external),
910 fn def_id(&self) -> Option<DefId> {
911 self.def.get().as_ref().map(Def::def_id)
914 fn is_normal(&self) -> bool {
915 match self.def.get() {
916 Some(Def::Mod(_)) | Some(Def::ForeignMod(_)) => true,
921 fn is_trait(&self) -> bool {
922 match self.def.get() {
923 Some(Def::Trait(_)) => true,
928 fn all_imports_resolved(&self) -> bool {
929 if self.imports.borrow_state() == ::std::cell::BorrowState::Writing {
930 // it is currently being resolved ! so nope
933 self.imports.borrow().len() == self.resolved_import_count.get()
937 pub fn inc_glob_count(&self) {
938 self.glob_count.set(self.glob_count.get() + 1);
940 pub fn dec_glob_count(&self) {
941 assert!(self.glob_count.get() > 0);
942 self.glob_count.set(self.glob_count.get() - 1);
944 pub fn inc_pub_count(&self) {
945 self.pub_count.set(self.pub_count.get() + 1);
947 pub fn dec_pub_count(&self) {
948 assert!(self.pub_count.get() > 0);
949 self.pub_count.set(self.pub_count.get() - 1);
951 pub fn inc_pub_glob_count(&self) {
952 self.pub_glob_count.set(self.pub_glob_count.get() + 1);
954 pub fn dec_pub_glob_count(&self) {
955 assert!(self.pub_glob_count.get() > 0);
956 self.pub_glob_count.set(self.pub_glob_count.get() - 1);
960 impl<'a> fmt::Debug for ModuleS<'a> {
961 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
975 flags DefModifiers: u8 {
976 // Enum variants are always considered `PUBLIC`, this is needed for `use Enum::Variant`
977 // or `use Enum::*` to work on private enums.
978 const PUBLIC = 1 << 0,
979 const IMPORTABLE = 1 << 1,
980 // Variants are considered `PUBLIC`, but some of them live in private enums.
981 // We need to track them to prohibit reexports like `pub use PrivEnum::Variant`.
982 const PRIVATE_VARIANT = 1 << 2,
986 // Records a possibly-private value, type, or module definition.
989 modifiers: DefModifiers, // see note in ImportResolutionPerNamespace about how to use this
990 def_or_module: DefOrModule<'a>,
995 enum DefOrModule<'a> {
1000 impl<'a> NsDef<'a> {
1001 fn create_from_module(module: Module<'a>, span: Option<Span>) -> Self {
1002 let modifiers = if module.is_public {
1003 DefModifiers::PUBLIC
1005 DefModifiers::empty()
1006 } | DefModifiers::IMPORTABLE;
1008 NsDef { modifiers: modifiers, def_or_module: DefOrModule::Module(module), span: span }
1011 fn create_from_def(def: Def, modifiers: DefModifiers, span: Option<Span>) -> Self {
1012 NsDef { modifiers: modifiers, def_or_module: DefOrModule::Def(def), span: span }
1015 fn module(&self) -> Option<Module<'a>> {
1016 match self.def_or_module {
1017 DefOrModule::Module(ref module) => Some(module),
1018 DefOrModule::Def(_) => None,
1022 fn def(&self) -> Option<Def> {
1023 match self.def_or_module {
1024 DefOrModule::Def(def) => Some(def),
1025 DefOrModule::Module(ref module) => module.def.get(),
1030 // Records at most one definition that a name in a namespace is bound to
1031 #[derive(Clone,Debug)]
1032 pub struct NameBinding<'a>(Rc<RefCell<Option<NsDef<'a>>>>);
1034 impl<'a> NameBinding<'a> {
1036 NameBinding(Rc::new(RefCell::new(None)))
1039 fn create_from_module(module: Module<'a>) -> Self {
1040 NameBinding(Rc::new(RefCell::new(Some(NsDef::create_from_module(module, None)))))
1043 fn set(&self, ns_def: NsDef<'a>) {
1044 *self.0.borrow_mut() = Some(ns_def);
1047 fn set_modifiers(&self, modifiers: DefModifiers) {
1048 if let Some(ref mut ns_def) = *self.0.borrow_mut() {
1049 ns_def.modifiers = modifiers
1053 fn borrow(&self) -> ::std::cell::Ref<Option<NsDef<'a>>> {
1057 // Lifted versions of the NsDef methods and fields
1058 fn def(&self) -> Option<Def> {
1059 self.borrow().as_ref().and_then(NsDef::def)
1061 fn module(&self) -> Option<Module<'a>> {
1062 self.borrow().as_ref().and_then(NsDef::module)
1064 fn span(&self) -> Option<Span> {
1065 self.borrow().as_ref().and_then(|def| def.span)
1067 fn modifiers(&self) -> Option<DefModifiers> {
1068 self.borrow().as_ref().and_then(|def| Some(def.modifiers))
1071 fn defined(&self) -> bool {
1072 self.borrow().is_some()
1075 fn defined_with(&self, modifiers: DefModifiers) -> bool {
1076 self.modifiers().map(|m| m.contains(modifiers)).unwrap_or(false)
1079 fn is_public(&self) -> bool {
1080 self.defined_with(DefModifiers::PUBLIC)
1083 fn def_and_lp(&self) -> (Def, LastPrivate) {
1084 let def = self.def().unwrap();
1085 (def, LastMod(if self.is_public() { AllPublic } else { DependsOn(def.def_id()) }))
1089 // Records the definitions (at most one for each namespace) that a name is
1091 #[derive(Clone,Debug)]
1092 pub struct NameBindings<'a> {
1093 type_ns: NameBinding<'a>, // < Meaning in type namespace.
1094 value_ns: NameBinding<'a>, // < Meaning in value namespace.
1097 impl<'a> ::std::ops::Index<Namespace> for NameBindings<'a> {
1098 type Output = NameBinding<'a>;
1099 fn index(&self, namespace: Namespace) -> &NameBinding<'a> {
1100 match namespace { TypeNS => &self.type_ns, ValueNS => &self.value_ns }
1104 impl<'a> NameBindings<'a> {
1107 type_ns: NameBinding::new(),
1108 value_ns: NameBinding::new(),
1112 /// Creates a new module in this set of name bindings.
1113 fn define_module(&self, module: Module<'a>, sp: Span) {
1114 self.type_ns.set(NsDef::create_from_module(module, Some(sp)));
1117 /// Records a type definition.
1118 fn define_type(&self, def: Def, sp: Span, modifiers: DefModifiers) {
1119 debug!("defining type for def {:?} with modifiers {:?}", def, modifiers);
1120 self.type_ns.set(NsDef::create_from_def(def, modifiers, Some(sp)));
1123 /// Records a value definition.
1124 fn define_value(&self, def: Def, sp: Span, modifiers: DefModifiers) {
1125 debug!("defining value for def {:?} with modifiers {:?}", def, modifiers);
1126 self.value_ns.set(NsDef::create_from_def(def, modifiers, Some(sp)));
1130 /// Interns the names of the primitive types.
1131 struct PrimitiveTypeTable {
1132 primitive_types: HashMap<Name, PrimTy>,
1135 impl PrimitiveTypeTable {
1136 fn new() -> PrimitiveTypeTable {
1137 let mut table = PrimitiveTypeTable { primitive_types: HashMap::new() };
1139 table.intern("bool", TyBool);
1140 table.intern("char", TyChar);
1141 table.intern("f32", TyFloat(TyF32));
1142 table.intern("f64", TyFloat(TyF64));
1143 table.intern("isize", TyInt(TyIs));
1144 table.intern("i8", TyInt(TyI8));
1145 table.intern("i16", TyInt(TyI16));
1146 table.intern("i32", TyInt(TyI32));
1147 table.intern("i64", TyInt(TyI64));
1148 table.intern("str", TyStr);
1149 table.intern("usize", TyUint(TyUs));
1150 table.intern("u8", TyUint(TyU8));
1151 table.intern("u16", TyUint(TyU16));
1152 table.intern("u32", TyUint(TyU32));
1153 table.intern("u64", TyUint(TyU64));
1158 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1159 self.primitive_types.insert(token::intern(string), primitive_type);
1163 /// The main resolver class.
1164 pub struct Resolver<'a, 'tcx: 'a> {
1165 session: &'a Session,
1167 ast_map: &'a hir_map::Map<'tcx>,
1169 graph_root: Module<'a>,
1171 trait_item_map: FnvHashMap<(Name, DefId), DefId>,
1173 structs: FnvHashMap<DefId, Vec<Name>>,
1175 // The number of imports that are currently unresolved.
1176 unresolved_imports: usize,
1178 // The module that represents the current item scope.
1179 current_module: Module<'a>,
1181 // The current set of local scopes, for values.
1182 // FIXME #4948: Reuse ribs to avoid allocation.
1183 value_ribs: Vec<Rib>,
1185 // The current set of local scopes, for types.
1186 type_ribs: Vec<Rib>,
1188 // The current set of local scopes, for labels.
1189 label_ribs: Vec<Rib>,
1191 // The trait that the current context can refer to.
1192 current_trait_ref: Option<(DefId, TraitRef)>,
1194 // The current self type if inside an impl (used for better errors).
1195 current_self_type: Option<Ty>,
1197 // The idents for the primitive types.
1198 primitive_type_table: PrimitiveTypeTable,
1200 def_map: RefCell<DefMap>,
1201 freevars: FreevarMap,
1202 freevars_seen: NodeMap<NodeMap<usize>>,
1203 export_map: ExportMap,
1204 trait_map: TraitMap,
1205 external_exports: ExternalExports,
1207 // Whether or not to print error messages. Can be set to true
1208 // when getting additional info for error message suggestions,
1209 // so as to avoid printing duplicate errors
1212 make_glob_map: bool,
1213 // Maps imports to the names of items actually imported (this actually maps
1214 // all imports, but only glob imports are actually interesting).
1217 used_imports: HashSet<(NodeId, Namespace)>,
1218 used_crates: HashSet<CrateNum>,
1220 // Callback function for intercepting walks
1221 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>,
1222 // The intention is that the callback modifies this flag.
1223 // Once set, the resolver falls out of the walk, preserving the ribs.
1226 arenas: &'a ResolverArenas<'a>,
1229 pub struct ResolverArenas<'a> {
1230 modules: arena::TypedArena<ModuleS<'a>>,
1233 #[derive(PartialEq)]
1234 enum FallbackChecks {
1236 OnlyTraitAndStatics,
1239 impl<'a, 'tcx> Resolver<'a, 'tcx> {
1240 fn new(session: &'a Session,
1241 ast_map: &'a hir_map::Map<'tcx>,
1242 make_glob_map: MakeGlobMap,
1243 arenas: &'a ResolverArenas<'a>)
1244 -> Resolver<'a, 'tcx> {
1245 let root_def_id = ast_map.local_def_id(CRATE_NODE_ID);
1246 let graph_root = ModuleS::new(NoParentLink, Some(Def::Mod(root_def_id)), false, true);
1247 let graph_root = arenas.modules.alloc(graph_root);
1254 // The outermost module has def ID 0; this is not reflected in the
1256 graph_root: graph_root,
1258 trait_item_map: FnvHashMap(),
1259 structs: FnvHashMap(),
1261 unresolved_imports: 0,
1263 current_module: graph_root,
1264 value_ribs: Vec::new(),
1265 type_ribs: Vec::new(),
1266 label_ribs: Vec::new(),
1268 current_trait_ref: None,
1269 current_self_type: None,
1271 primitive_type_table: PrimitiveTypeTable::new(),
1273 def_map: RefCell::new(NodeMap()),
1274 freevars: NodeMap(),
1275 freevars_seen: NodeMap(),
1276 export_map: NodeMap(),
1277 trait_map: NodeMap(),
1278 used_imports: HashSet::new(),
1279 used_crates: HashSet::new(),
1280 external_exports: DefIdSet(),
1283 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1284 glob_map: HashMap::new(),
1293 fn arenas() -> ResolverArenas<'a> {
1295 modules: arena::TypedArena::new(),
1299 fn new_module(&self,
1300 parent_link: ParentLink<'a>,
1303 is_public: bool) -> Module<'a> {
1304 self.arenas.modules.alloc(ModuleS::new(parent_link, def, external, is_public))
1308 fn record_import_use(&mut self, import_id: NodeId, name: Name) {
1309 if !self.make_glob_map {
1312 if self.glob_map.contains_key(&import_id) {
1313 self.glob_map.get_mut(&import_id).unwrap().insert(name);
1317 let mut new_set = HashSet::new();
1318 new_set.insert(name);
1319 self.glob_map.insert(import_id, new_set);
1322 fn get_trait_name(&self, did: DefId) -> Name {
1323 if let Some(node_id) = self.ast_map.as_local_node_id(did) {
1324 self.ast_map.expect_item(node_id).name
1326 self.session.cstore.item_name(did)
1330 /// Check that an external crate doesn't collide with items or other external crates.
1331 fn check_for_conflicts_for_external_crate(&self, module: Module<'a>, name: Name, span: Span) {
1332 if module.external_module_children.borrow().contains_key(&name) {
1333 span_err!(self.session,
1336 "an external crate named `{}` has already been imported into this module",
1339 match module.children.borrow().get(&name) {
1340 Some(name_bindings) if name_bindings.type_ns.defined() => {
1342 name_bindings.type_ns.span().unwrap_or(codemap::DUMMY_SP),
1343 ResolutionError::NameConflictsWithExternCrate(name));
1349 /// Checks that the names of items don't collide with external crates.
1350 fn check_for_conflicts_between_external_crates_and_items(&self,
1354 if module.external_module_children.borrow().contains_key(&name) {
1355 resolve_error(self, span, ResolutionError::NameConflictsWithExternCrate(name));
1359 /// Resolves the given module path from the given root `module_`.
1360 fn resolve_module_path_from_root(&mut self,
1361 module_: Module<'a>,
1362 module_path: &[Name],
1365 name_search_type: NameSearchType,
1367 -> ResolveResult<(Module<'a>, LastPrivate)> {
1368 fn search_parent_externals<'a>(needle: Name, module: Module<'a>)
1369 -> Option<Module<'a>> {
1370 match module.external_module_children.borrow().get(&needle) {
1371 Some(_) => Some(module),
1372 None => match module.parent_link {
1373 ModuleParentLink(ref parent, _) => {
1374 search_parent_externals(needle, parent)
1381 let mut search_module = module_;
1382 let mut index = index;
1383 let module_path_len = module_path.len();
1384 let mut closest_private = lp;
1386 // Resolve the module part of the path. This does not involve looking
1387 // upward though scope chains; we simply resolve names directly in
1388 // modules as we go.
1389 while index < module_path_len {
1390 let name = module_path[index];
1391 match self.resolve_name_in_module(search_module,
1397 let segment_name = name.as_str();
1398 let module_name = module_to_string(search_module);
1399 let mut span = span;
1400 let msg = if "???" == &module_name[..] {
1401 span.hi = span.lo + Pos::from_usize(segment_name.len());
1403 match search_parent_externals(name, &self.current_module) {
1405 let path_str = names_to_string(module_path);
1406 let target_mod_str = module_to_string(&*module);
1407 let current_mod_str = module_to_string(&*self.current_module);
1409 let prefix = if target_mod_str == current_mod_str {
1410 "self::".to_string()
1412 format!("{}::", target_mod_str)
1415 format!("Did you mean `{}{}`?", prefix, path_str)
1417 None => format!("Maybe a missing `extern crate {}`?", segment_name),
1420 format!("Could not find `{}` in `{}`", segment_name, module_name)
1423 return Failed(Some((span, msg)));
1425 Failed(err) => return Failed(err),
1427 debug!("(resolving module path for import) module resolution is \
1430 return Indeterminate;
1432 Success((target, used_proxy)) => {
1433 // Check to see whether there are type bindings, and, if
1434 // so, whether there is a module within.
1435 if let Some(module_def) = target.binding.module() {
1436 // track extern crates for unused_extern_crate lint
1437 if let Some(did) = module_def.def_id() {
1438 self.used_crates.insert(did.krate);
1441 search_module = module_def;
1443 // Keep track of the closest private module used
1444 // when resolving this import chain.
1445 if !used_proxy && !search_module.is_public {
1446 if let Some(did) = search_module.def_id() {
1447 closest_private = LastMod(DependsOn(did));
1451 let msg = format!("Not a module `{}`", name);
1452 return Failed(Some((span, msg)));
1460 return Success((search_module, closest_private));
1463 /// Attempts to resolve the module part of an import directive or path
1464 /// rooted at the given module.
1466 /// On success, returns the resolved module, and the closest *private*
1467 /// module found to the destination when resolving this path.
1468 fn resolve_module_path(&mut self,
1469 module_: Module<'a>,
1470 module_path: &[Name],
1471 use_lexical_scope: UseLexicalScopeFlag,
1473 name_search_type: NameSearchType)
1474 -> ResolveResult<(Module<'a>, LastPrivate)> {
1475 let module_path_len = module_path.len();
1476 assert!(module_path_len > 0);
1478 debug!("(resolving module path for import) processing `{}` rooted at `{}`",
1479 names_to_string(module_path),
1480 module_to_string(&*module_));
1482 // Resolve the module prefix, if any.
1483 let module_prefix_result = self.resolve_module_prefix(module_, module_path);
1488 match module_prefix_result {
1490 let mpath = names_to_string(module_path);
1491 let mpath = &mpath[..];
1492 match mpath.rfind(':') {
1494 let msg = format!("Could not find `{}` in `{}`",
1495 // idx +- 1 to account for the
1496 // colons on either side
1499 return Failed(Some((span, msg)));
1502 return Failed(None);
1506 Failed(err) => return Failed(err),
1508 debug!("(resolving module path for import) indeterminate; bailing");
1509 return Indeterminate;
1511 Success(NoPrefixFound) => {
1512 // There was no prefix, so we're considering the first element
1513 // of the path. How we handle this depends on whether we were
1514 // instructed to use lexical scope or not.
1515 match use_lexical_scope {
1516 DontUseLexicalScope => {
1517 // This is a crate-relative path. We will start the
1518 // resolution process at index zero.
1519 search_module = self.graph_root;
1521 last_private = LastMod(AllPublic);
1523 UseLexicalScope => {
1524 // This is not a crate-relative path. We resolve the
1525 // first component of the path in the current lexical
1526 // scope and then proceed to resolve below that.
1527 match self.resolve_module_in_lexical_scope(module_, module_path[0]) {
1528 Failed(err) => return Failed(err),
1530 debug!("(resolving module path for import) indeterminate; bailing");
1531 return Indeterminate;
1533 Success(containing_module) => {
1534 search_module = containing_module;
1536 last_private = LastMod(AllPublic);
1542 Success(PrefixFound(ref containing_module, index)) => {
1543 search_module = containing_module;
1544 start_index = index;
1545 last_private = LastMod(DependsOn(containing_module.def_id()
1550 self.resolve_module_path_from_root(search_module,
1558 /// Invariant: This must only be called during main resolution, not during
1559 /// import resolution.
1560 fn resolve_item_in_lexical_scope(&mut self,
1561 module_: Module<'a>,
1563 namespace: Namespace,
1565 -> ResolveResult<(Target<'a>, bool)> {
1566 debug!("(resolving item in lexical scope) resolving `{}` in namespace {:?} in `{}`",
1569 module_to_string(&*module_));
1571 // The current module node is handled specially. First, check for
1572 // its immediate children.
1573 build_reduced_graph::populate_module_if_necessary(self, &module_);
1575 match module_.children.borrow().get(&name) {
1576 Some(name_bindings) if name_bindings[namespace].defined() => {
1577 debug!("top name bindings succeeded");
1578 return Success((Target::new(module_,
1579 name_bindings[namespace].clone(),
1584 // Not found; continue.
1588 // Now check for its import directives. We don't have to have resolved
1589 // all its imports in the usual way; this is because chains of
1590 // adjacent import statements are processed as though they mutated the
1592 if let Some(import_resolution) = module_.import_resolutions.borrow().get(&name) {
1593 match import_resolution[namespace].target.clone() {
1595 // Not found; continue.
1596 debug!("(resolving item in lexical scope) found import resolution, but not \
1601 debug!("(resolving item in lexical scope) using import resolution");
1602 // track used imports and extern crates as well
1603 let id = import_resolution[namespace].id;
1605 self.used_imports.insert((id, namespace));
1606 self.record_import_use(id, name);
1607 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id() {
1608 self.used_crates.insert(kid);
1611 return Success((target, false));
1616 // Search for external modules.
1617 if namespace == TypeNS {
1618 let children = module_.external_module_children.borrow();
1619 if let Some(module) = children.get(&name) {
1620 let name_binding = NameBinding::create_from_module(module);
1621 debug!("lower name bindings succeeded");
1622 return Success((Target::new(module_, name_binding, Shadowable::Never),
1627 // Finally, proceed up the scope chain looking for parent modules.
1628 let mut search_module = module_;
1630 // Go to the next parent.
1631 match search_module.parent_link {
1633 // No more parents. This module was unresolved.
1634 debug!("(resolving item in lexical scope) unresolved module");
1635 return Failed(None);
1637 ModuleParentLink(parent_module_node, _) => {
1638 if search_module.is_normal() {
1639 // We stop the search here.
1640 debug!("(resolving item in lexical scope) unresolved module: not \
1641 searching through module parents");
1642 return Failed(None);
1644 search_module = parent_module_node;
1647 BlockParentLink(parent_module_node, _) => {
1648 search_module = parent_module_node;
1652 // Resolve the name in the parent module.
1653 match self.resolve_name_in_module(search_module,
1658 Failed(Some((span, msg))) => {
1659 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
1661 Failed(None) => (), // Continue up the search chain.
1663 // We couldn't see through the higher scope because of an
1664 // unresolved import higher up. Bail.
1666 debug!("(resolving item in lexical scope) indeterminate higher scope; bailing");
1667 return Indeterminate;
1669 Success((target, used_reexport)) => {
1670 // We found the module.
1671 debug!("(resolving item in lexical scope) found name in module, done");
1672 return Success((target, used_reexport));
1678 /// Resolves a module name in the current lexical scope.
1679 fn resolve_module_in_lexical_scope(&mut self,
1680 module_: Module<'a>,
1682 -> ResolveResult<Module<'a>> {
1683 // If this module is an anonymous module, resolve the item in the
1684 // lexical scope. Otherwise, resolve the item from the crate root.
1685 let resolve_result = self.resolve_item_in_lexical_scope(module_, name, TypeNS, true);
1686 match resolve_result {
1687 Success((target, _)) => {
1688 if let Some(module_def) = target.binding.module() {
1689 return Success(module_def)
1691 debug!("!!! (resolving module in lexical scope) module \
1692 wasn't actually a module!");
1693 return Failed(None);
1697 debug!("(resolving module in lexical scope) indeterminate; bailing");
1698 return Indeterminate;
1701 debug!("(resolving module in lexical scope) failed to resolve");
1707 /// Returns the nearest normal module parent of the given module.
1708 fn get_nearest_normal_module_parent(&mut self, module_: Module<'a>) -> Option<Module<'a>> {
1709 let mut module_ = module_;
1711 match module_.parent_link {
1712 NoParentLink => return None,
1713 ModuleParentLink(new_module, _) |
1714 BlockParentLink(new_module, _) => {
1715 let new_module = new_module;
1716 if new_module.is_normal() {
1717 return Some(new_module);
1719 module_ = new_module;
1725 /// Returns the nearest normal module parent of the given module, or the
1726 /// module itself if it is a normal module.
1727 fn get_nearest_normal_module_parent_or_self(&mut self, module_: Module<'a>) -> Module<'a> {
1728 if module_.is_normal() {
1731 match self.get_nearest_normal_module_parent(module_) {
1733 Some(new_module) => new_module,
1737 /// Resolves a "module prefix". A module prefix is one or both of (a) `self::`;
1738 /// (b) some chain of `super::`.
1739 /// grammar: (SELF MOD_SEP ) ? (SUPER MOD_SEP) *
1740 fn resolve_module_prefix(&mut self,
1741 module_: Module<'a>,
1742 module_path: &[Name])
1743 -> ResolveResult<ModulePrefixResult<'a>> {
1744 // Start at the current module if we see `self` or `super`, or at the
1745 // top of the crate otherwise.
1746 let mut i = match &*module_path[0].as_str() {
1749 _ => return Success(NoPrefixFound),
1751 let mut containing_module = self.get_nearest_normal_module_parent_or_self(module_);
1753 // Now loop through all the `super`s we find.
1754 while i < module_path.len() && "super" == module_path[i].as_str() {
1755 debug!("(resolving module prefix) resolving `super` at {}",
1756 module_to_string(&*containing_module));
1757 match self.get_nearest_normal_module_parent(containing_module) {
1758 None => return Failed(None),
1759 Some(new_module) => {
1760 containing_module = new_module;
1766 debug!("(resolving module prefix) finished resolving prefix at {}",
1767 module_to_string(&*containing_module));
1769 return Success(PrefixFound(containing_module, i));
1772 /// Attempts to resolve the supplied name in the given module for the
1773 /// given namespace. If successful, returns the target corresponding to
1776 /// The boolean returned on success is an indicator of whether this lookup
1777 /// passed through a public re-export proxy.
1778 fn resolve_name_in_module(&mut self,
1779 module_: Module<'a>,
1781 namespace: Namespace,
1782 name_search_type: NameSearchType,
1783 allow_private_imports: bool)
1784 -> ResolveResult<(Target<'a>, bool)> {
1785 debug!("(resolving name in module) resolving `{}` in `{}`",
1787 module_to_string(&*module_));
1789 // First, check the direct children of the module.
1790 build_reduced_graph::populate_module_if_necessary(self, &module_);
1792 let children = module_.children.borrow();
1793 match children.get(&name) {
1794 Some(name_bindings) if name_bindings[namespace].defined() => {
1795 debug!("(resolving name in module) found node as child");
1796 return Success((Target::new(module_,
1797 name_bindings[namespace].clone(),
1806 // Next, check the module's imports if necessary.
1808 // If this is a search of all imports, we should be done with glob
1809 // resolution at this point.
1810 if name_search_type == PathSearch {
1811 assert_eq!(module_.glob_count.get(), 0);
1814 // Check the list of resolved imports.
1815 let children = module_.import_resolutions.borrow();
1816 match children.get(&name) {
1817 Some(import_resolution) if allow_private_imports ||
1818 import_resolution[namespace].is_public => {
1820 if import_resolution[namespace].is_public &&
1821 import_resolution.outstanding_references != 0 {
1822 debug!("(resolving name in module) import unresolved; bailing out");
1823 return Indeterminate;
1825 match import_resolution[namespace].target.clone() {
1827 debug!("(resolving name in module) name found, but not in namespace {:?}",
1831 debug!("(resolving name in module) resolved to import");
1832 // track used imports and extern crates as well
1833 let id = import_resolution[namespace].id;
1834 self.used_imports.insert((id, namespace));
1835 self.record_import_use(id, name);
1836 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id() {
1837 self.used_crates.insert(kid);
1839 return Success((target, true));
1843 Some(..) | None => {} // Continue.
1846 // Finally, search through external children.
1847 if namespace == TypeNS {
1848 let children = module_.external_module_children.borrow();
1849 if let Some(module) = children.get(&name) {
1850 let name_binding = NameBinding::create_from_module(module);
1851 return Success((Target::new(module_, name_binding, Shadowable::Never),
1856 // We're out of luck.
1857 debug!("(resolving name in module) failed to resolve `{}`", name);
1858 return Failed(None);
1861 fn report_unresolved_imports(&mut self, module_: Module<'a>) {
1862 let index = module_.resolved_import_count.get();
1863 let imports = module_.imports.borrow();
1864 let import_count = imports.len();
1865 if index != import_count {
1867 (*imports)[index].span,
1868 ResolutionError::UnresolvedImport(None));
1871 // Descend into children and anonymous children.
1872 build_reduced_graph::populate_module_if_necessary(self, &module_);
1874 for (_, child_node) in module_.children.borrow().iter() {
1875 match child_node.type_ns.module() {
1879 Some(child_module) => {
1880 self.report_unresolved_imports(child_module);
1885 for (_, module_) in module_.anonymous_children.borrow().iter() {
1886 self.report_unresolved_imports(module_);
1892 // We maintain a list of value ribs and type ribs.
1894 // Simultaneously, we keep track of the current position in the module
1895 // graph in the `current_module` pointer. When we go to resolve a name in
1896 // the value or type namespaces, we first look through all the ribs and
1897 // then query the module graph. When we resolve a name in the module
1898 // namespace, we can skip all the ribs (since nested modules are not
1899 // allowed within blocks in Rust) and jump straight to the current module
1902 // Named implementations are handled separately. When we find a method
1903 // call, we consult the module node to find all of the implementations in
1904 // scope. This information is lazily cached in the module node. We then
1905 // generate a fake "implementation scope" containing all the
1906 // implementations thus found, for compatibility with old resolve pass.
1908 fn with_scope<F>(&mut self, name: Option<Name>, f: F)
1909 where F: FnOnce(&mut Resolver)
1911 let orig_module = self.current_module;
1913 // Move down in the graph.
1919 build_reduced_graph::populate_module_if_necessary(self, &orig_module);
1921 match orig_module.children.borrow().get(&name) {
1923 debug!("!!! (with scope) didn't find `{}` in `{}`",
1925 module_to_string(&*orig_module));
1927 Some(name_bindings) => {
1928 match name_bindings.type_ns.module() {
1930 debug!("!!! (with scope) didn't find module for `{}` in `{}`",
1932 module_to_string(&*orig_module));
1935 self.current_module = module_;
1945 self.current_module = orig_module;
1948 /// Searches the current set of local scopes for labels.
1949 /// Stops after meeting a closure.
1950 fn search_label(&self, name: Name) -> Option<DefLike> {
1951 for rib in self.label_ribs.iter().rev() {
1957 // Do not resolve labels across function boundary
1961 let result = rib.bindings.get(&name).cloned();
1962 if result.is_some() {
1969 fn resolve_crate(&mut self, krate: &hir::Crate) {
1970 debug!("(resolving crate) starting");
1972 intravisit::walk_crate(self, krate);
1975 fn check_if_primitive_type_name(&self, name: Name, span: Span) {
1976 if let Some(_) = self.primitive_type_table.primitive_types.get(&name) {
1977 span_err!(self.session,
1980 "user-defined types or type parameters cannot shadow the primitive types");
1984 fn resolve_item(&mut self, item: &Item) {
1985 let name = item.name;
1987 debug!("(resolving item) resolving {}", name);
1990 ItemEnum(_, ref generics) |
1991 ItemTy(_, ref generics) |
1992 ItemStruct(_, ref generics) => {
1993 self.check_if_primitive_type_name(name, item.span);
1995 self.with_type_parameter_rib(HasTypeParameters(generics, TypeSpace, ItemRibKind),
1996 |this| intravisit::walk_item(this, item));
1998 ItemFn(_, _, _, _, ref generics, _) => {
1999 self.with_type_parameter_rib(HasTypeParameters(generics, FnSpace, ItemRibKind),
2000 |this| intravisit::walk_item(this, item));
2003 ItemDefaultImpl(_, ref trait_ref) => {
2004 self.with_optional_trait_ref(Some(trait_ref), |_, _| {});
2006 ItemImpl(_, _, ref generics, ref opt_trait_ref, ref self_type, ref impl_items) => {
2007 self.resolve_implementation(generics,
2014 ItemTrait(_, ref generics, ref bounds, ref trait_items) => {
2015 self.check_if_primitive_type_name(name, item.span);
2017 // Create a new rib for the trait-wide type parameters.
2018 self.with_type_parameter_rib(HasTypeParameters(generics,
2022 let local_def_id = this.ast_map.local_def_id(item.id);
2023 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2024 this.visit_generics(generics);
2025 walk_list!(this, visit_ty_param_bound, bounds);
2027 for trait_item in trait_items {
2028 match trait_item.node {
2029 hir::ConstTraitItem(_, ref default) => {
2030 // Only impose the restrictions of
2031 // ConstRibKind if there's an actual constant
2032 // expression in a provided default.
2033 if default.is_some() {
2034 this.with_constant_rib(|this| {
2035 intravisit::walk_trait_item(this, trait_item)
2038 intravisit::walk_trait_item(this, trait_item)
2041 hir::MethodTraitItem(ref sig, _) => {
2042 let type_parameters =
2043 HasTypeParameters(&sig.generics,
2046 this.with_type_parameter_rib(type_parameters, |this| {
2047 intravisit::walk_trait_item(this, trait_item)
2050 hir::TypeTraitItem(..) => {
2051 this.check_if_primitive_type_name(trait_item.name,
2053 this.with_type_parameter_rib(NoTypeParameters, |this| {
2054 intravisit::walk_trait_item(this, trait_item)
2063 ItemMod(_) | ItemForeignMod(_) => {
2064 self.with_scope(Some(name), |this| {
2065 intravisit::walk_item(this, item);
2069 ItemConst(..) | ItemStatic(..) => {
2070 self.with_constant_rib(|this| {
2071 intravisit::walk_item(this, item);
2075 ItemUse(ref view_path) => {
2076 // check for imports shadowing primitive types
2077 let check_rename = |this: &Self, id, name| {
2078 match this.def_map.borrow().get(&id).map(|d| d.full_def()) {
2079 Some(Def::Enum(..)) | Some(Def::TyAlias(..)) | Some(Def::Struct(..)) |
2080 Some(Def::Trait(..)) | None => {
2081 this.check_if_primitive_type_name(name, item.span);
2087 match view_path.node {
2088 hir::ViewPathSimple(name, _) => {
2089 check_rename(self, item.id, name);
2091 hir::ViewPathList(ref prefix, ref items) => {
2093 if let Some(name) = item.node.rename() {
2094 check_rename(self, item.node.id(), name);
2098 // Resolve prefix of an import with empty braces (issue #28388)
2099 if items.is_empty() && !prefix.segments.is_empty() {
2100 match self.resolve_crate_relative_path(prefix.span,
2104 self.record_def(item.id, PathResolution::new(def, lp, 0)),
2108 ResolutionError::FailedToResolve(
2109 &path_names_to_string(prefix, 0)));
2110 self.record_def(item.id, err_path_resolution());
2119 ItemExternCrate(_) => {
2120 // do nothing, these are just around to be encoded
2125 fn with_type_parameter_rib<F>(&mut self, type_parameters: TypeParameters, f: F)
2126 where F: FnOnce(&mut Resolver)
2128 match type_parameters {
2129 HasTypeParameters(generics, space, rib_kind) => {
2130 let mut function_type_rib = Rib::new(rib_kind);
2131 let mut seen_bindings = HashSet::new();
2132 for (index, type_parameter) in generics.ty_params.iter().enumerate() {
2133 let name = type_parameter.name;
2134 debug!("with_type_parameter_rib: {}", type_parameter.id);
2136 if seen_bindings.contains(&name) {
2138 type_parameter.span,
2139 ResolutionError::NameAlreadyUsedInTypeParameterList(name));
2141 seen_bindings.insert(name);
2143 // plain insert (no renaming)
2144 function_type_rib.bindings
2146 DlDef(Def::TyParam(space,
2149 .local_def_id(type_parameter.id),
2152 self.type_ribs.push(function_type_rib);
2155 NoTypeParameters => {
2162 match type_parameters {
2163 HasTypeParameters(..) => {
2165 self.type_ribs.pop();
2168 NoTypeParameters => {}
2172 fn with_label_rib<F>(&mut self, f: F)
2173 where F: FnOnce(&mut Resolver)
2175 self.label_ribs.push(Rib::new(NormalRibKind));
2178 self.label_ribs.pop();
2182 fn with_constant_rib<F>(&mut self, f: F)
2183 where F: FnOnce(&mut Resolver)
2185 self.value_ribs.push(Rib::new(ConstantItemRibKind));
2186 self.type_ribs.push(Rib::new(ConstantItemRibKind));
2189 self.type_ribs.pop();
2190 self.value_ribs.pop();
2194 fn resolve_function(&mut self, rib_kind: RibKind, declaration: &FnDecl, block: &Block) {
2195 // Create a value rib for the function.
2196 self.value_ribs.push(Rib::new(rib_kind));
2198 // Create a label rib for the function.
2199 self.label_ribs.push(Rib::new(rib_kind));
2201 // Add each argument to the rib.
2202 let mut bindings_list = HashMap::new();
2203 for argument in &declaration.inputs {
2204 self.resolve_pattern(&*argument.pat, ArgumentIrrefutableMode, &mut bindings_list);
2206 self.visit_ty(&*argument.ty);
2208 debug!("(resolving function) recorded argument");
2210 intravisit::walk_fn_ret_ty(self, &declaration.output);
2212 // Resolve the function body.
2213 self.visit_block(block);
2215 debug!("(resolving function) leaving function");
2218 self.label_ribs.pop();
2219 self.value_ribs.pop();
2223 fn resolve_trait_reference(&mut self,
2227 -> Result<PathResolution, ()> {
2228 if let Some(path_res) = self.resolve_path(id, trait_path, path_depth, TypeNS, true) {
2229 if let Def::Trait(_) = path_res.base_def {
2230 debug!("(resolving trait) found trait def: {:?}", path_res);
2234 resolve_struct_error(self,
2236 ResolutionError::IsNotATrait(&*path_names_to_string(trait_path,
2239 // If it's a typedef, give a note
2240 if let Def::TyAlias(..) = path_res.base_def {
2241 err.span_note(trait_path.span,
2242 "`type` aliases cannot be used for traits");
2250 ResolutionError::UndeclaredTraitName(&*path_names_to_string(trait_path,
2256 fn resolve_generics(&mut self, generics: &Generics) {
2257 for type_parameter in generics.ty_params.iter() {
2258 self.check_if_primitive_type_name(type_parameter.name, type_parameter.span);
2260 for predicate in &generics.where_clause.predicates {
2262 &hir::WherePredicate::BoundPredicate(_) |
2263 &hir::WherePredicate::RegionPredicate(_) => {}
2264 &hir::WherePredicate::EqPredicate(ref eq_pred) => {
2265 let path_res = self.resolve_path(eq_pred.id, &eq_pred.path, 0, TypeNS, true);
2266 if let Some(PathResolution { base_def: Def::TyParam(..), .. }) = path_res {
2267 self.record_def(eq_pred.id, path_res.unwrap());
2271 ResolutionError::UndeclaredAssociatedType);
2272 self.record_def(eq_pred.id, err_path_resolution());
2277 intravisit::walk_generics(self, generics);
2280 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2281 where F: FnOnce(&mut Resolver) -> T
2283 // Handle nested impls (inside fn bodies)
2284 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2285 let result = f(self);
2286 self.current_self_type = previous_value;
2290 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
2291 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2293 let mut new_val = None;
2294 let mut new_id = None;
2295 if let Some(trait_ref) = opt_trait_ref {
2296 if let Ok(path_res) = self.resolve_trait_reference(trait_ref.ref_id,
2299 assert!(path_res.depth == 0);
2300 self.record_def(trait_ref.ref_id, path_res);
2301 new_val = Some((path_res.base_def.def_id(), trait_ref.clone()));
2302 new_id = Some(path_res.base_def.def_id());
2304 self.record_def(trait_ref.ref_id, err_path_resolution());
2306 intravisit::walk_trait_ref(self, trait_ref);
2308 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2309 let result = f(self, new_id);
2310 self.current_trait_ref = original_trait_ref;
2314 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2315 where F: FnOnce(&mut Resolver)
2317 let mut self_type_rib = Rib::new(NormalRibKind);
2319 // plain insert (no renaming, types are not currently hygienic....)
2320 let name = special_names::type_self;
2321 self_type_rib.bindings.insert(name, DlDef(self_def));
2322 self.type_ribs.push(self_type_rib);
2325 self.type_ribs.pop();
2329 fn resolve_implementation(&mut self,
2330 generics: &Generics,
2331 opt_trait_reference: &Option<TraitRef>,
2334 impl_items: &[ImplItem]) {
2335 // If applicable, create a rib for the type parameters.
2336 self.with_type_parameter_rib(HasTypeParameters(generics,
2340 // Resolve the type parameters.
2341 this.visit_generics(generics);
2343 // Resolve the trait reference, if necessary.
2344 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2345 // Resolve the self type.
2346 this.visit_ty(self_type);
2348 this.with_self_rib(Def::SelfTy(trait_id, Some((item_id, self_type.id))), |this| {
2349 this.with_current_self_type(self_type, |this| {
2350 for impl_item in impl_items {
2351 match impl_item.node {
2352 hir::ImplItemKind::Const(..) => {
2353 // If this is a trait impl, ensure the const
2355 this.check_trait_item(impl_item.name,
2357 |n, s| ResolutionError::ConstNotMemberOfTrait(n, s));
2358 this.with_constant_rib(|this| {
2359 intravisit::walk_impl_item(this, impl_item);
2362 hir::ImplItemKind::Method(ref sig, _) => {
2363 // If this is a trait impl, ensure the method
2365 this.check_trait_item(impl_item.name,
2367 |n, s| ResolutionError::MethodNotMemberOfTrait(n, s));
2369 // We also need a new scope for the method-
2370 // specific type parameters.
2371 let type_parameters =
2372 HasTypeParameters(&sig.generics,
2375 this.with_type_parameter_rib(type_parameters, |this| {
2376 intravisit::walk_impl_item(this, impl_item);
2379 hir::ImplItemKind::Type(ref ty) => {
2380 // If this is a trait impl, ensure the type
2382 this.check_trait_item(impl_item.name,
2384 |n, s| ResolutionError::TypeNotMemberOfTrait(n, s));
2396 fn check_trait_item<F>(&self, name: Name, span: Span, err: F)
2397 where F: FnOnce(Name, &str) -> ResolutionError
2399 // If there is a TraitRef in scope for an impl, then the method must be in the
2401 if let Some((did, ref trait_ref)) = self.current_trait_ref {
2402 if !self.trait_item_map.contains_key(&(name, did)) {
2403 let path_str = path_names_to_string(&trait_ref.path, 0);
2404 resolve_error(self, span, err(name, &*path_str));
2409 fn resolve_local(&mut self, local: &Local) {
2410 // Resolve the type.
2411 walk_list!(self, visit_ty, &local.ty);
2413 // Resolve the initializer.
2414 walk_list!(self, visit_expr, &local.init);
2416 // Resolve the pattern.
2417 self.resolve_pattern(&*local.pat, LocalIrrefutableMode, &mut HashMap::new());
2420 // build a map from pattern identifiers to binding-info's.
2421 // this is done hygienically. This could arise for a macro
2422 // that expands into an or-pattern where one 'x' was from the
2423 // user and one 'x' came from the macro.
2424 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2425 let mut result = HashMap::new();
2426 pat_bindings(&self.def_map, pat, |binding_mode, _id, sp, path1| {
2427 let name = path1.node;
2431 binding_mode: binding_mode,
2437 // check that all of the arms in an or-pattern have exactly the
2438 // same set of bindings, with the same binding modes for each.
2439 fn check_consistent_bindings(&mut self, arm: &Arm) {
2440 if arm.pats.is_empty() {
2443 let map_0 = self.binding_mode_map(&*arm.pats[0]);
2444 for (i, p) in arm.pats.iter().enumerate() {
2445 let map_i = self.binding_mode_map(&**p);
2447 for (&key, &binding_0) in &map_0 {
2448 match map_i.get(&key) {
2452 ResolutionError::VariableNotBoundInPattern(key, i + 1));
2454 Some(binding_i) => {
2455 if binding_0.binding_mode != binding_i.binding_mode {
2458 ResolutionError::VariableBoundWithDifferentMode(key,
2465 for (&key, &binding) in &map_i {
2466 if !map_0.contains_key(&key) {
2469 ResolutionError::VariableNotBoundInParentPattern(key, i + 1));
2475 fn resolve_arm(&mut self, arm: &Arm) {
2476 self.value_ribs.push(Rib::new(NormalRibKind));
2478 let mut bindings_list = HashMap::new();
2479 for pattern in &arm.pats {
2480 self.resolve_pattern(&**pattern, RefutableMode, &mut bindings_list);
2483 // This has to happen *after* we determine which
2484 // pat_idents are variants
2485 self.check_consistent_bindings(arm);
2487 walk_list!(self, visit_expr, &arm.guard);
2488 self.visit_expr(&*arm.body);
2491 self.value_ribs.pop();
2495 fn resolve_block(&mut self, block: &Block) {
2496 debug!("(resolving block) entering block");
2497 self.value_ribs.push(Rib::new(NormalRibKind));
2499 // Move down in the graph, if there's an anonymous module rooted here.
2500 let orig_module = self.current_module;
2501 match orig_module.anonymous_children.borrow().get(&block.id) {
2505 Some(anonymous_module) => {
2506 debug!("(resolving block) found anonymous module, moving down");
2507 self.current_module = anonymous_module;
2511 // Check for imports appearing after non-item statements.
2512 let mut found_non_item = false;
2513 for statement in &block.stmts {
2514 if let hir::StmtDecl(ref declaration, _) = statement.node {
2515 if let hir::DeclItem(i) = declaration.node {
2516 let i = self.ast_map.expect_item(i.id);
2518 ItemExternCrate(_) | ItemUse(_) if found_non_item => {
2519 span_err!(self.session,
2522 "imports are not allowed after non-item statements");
2527 found_non_item = true
2530 found_non_item = true;
2534 // Descend into the block.
2535 intravisit::walk_block(self, block);
2539 self.current_module = orig_module;
2540 self.value_ribs.pop();
2542 debug!("(resolving block) leaving block");
2545 fn resolve_type(&mut self, ty: &Ty) {
2547 TyPath(ref maybe_qself, ref path) => {
2548 let resolution = match self.resolve_possibly_assoc_item(ty.id,
2549 maybe_qself.as_ref(),
2553 // `<T>::a::b::c` is resolved by typeck alone.
2554 TypecheckRequired => {
2555 // Resolve embedded types.
2556 intravisit::walk_ty(self, ty);
2559 ResolveAttempt(resolution) => resolution,
2562 // This is a path in the type namespace. Walk through scopes
2566 // Write the result into the def map.
2567 debug!("(resolving type) writing resolution for `{}` (id {}) = {:?}",
2568 path_names_to_string(path, 0),
2571 self.record_def(ty.id, def);
2574 self.record_def(ty.id, err_path_resolution());
2576 // Keep reporting some errors even if they're ignored above.
2577 self.resolve_path(ty.id, path, 0, TypeNS, true);
2579 let kind = if maybe_qself.is_some() {
2585 let self_type_name = special_idents::type_self.name;
2586 let is_invalid_self_type_name = path.segments.len() > 0 &&
2587 maybe_qself.is_none() &&
2588 path.segments[0].identifier.name ==
2590 if is_invalid_self_type_name {
2593 ResolutionError::SelfUsedOutsideImplOrTrait);
2597 ResolutionError::UseOfUndeclared(
2599 &*path_names_to_string(path,
2608 // Resolve embedded types.
2609 intravisit::walk_ty(self, ty);
2612 fn resolve_pattern(&mut self,
2614 mode: PatternBindingMode,
2615 // Maps idents to the node ID for the (outermost)
2616 // pattern that binds them
2617 bindings_list: &mut HashMap<Name, NodeId>) {
2618 let pat_id = pattern.id;
2619 walk_pat(pattern, |pattern| {
2620 match pattern.node {
2621 PatIdent(binding_mode, ref path1, ref at_rhs) => {
2622 // The meaning of PatIdent with no type parameters
2623 // depends on whether an enum variant or unit-like struct
2624 // with that name is in scope. The probing lookup has to
2625 // be careful not to emit spurious errors. Only matching
2626 // patterns (match) can match nullary variants or
2627 // unit-like structs. For binding patterns (let
2628 // and the LHS of @-patterns), matching such a value is
2629 // simply disallowed (since it's rarely what you want).
2630 let const_ok = mode == RefutableMode && at_rhs.is_none();
2632 let ident = path1.node;
2633 let renamed = ident.name;
2635 match self.resolve_bare_identifier_pattern(ident.unhygienic_name,
2637 FoundStructOrEnumVariant(def, lp) if const_ok => {
2638 debug!("(resolving pattern) resolving `{}` to struct or enum variant",
2641 self.enforce_default_binding_mode(pattern,
2644 self.record_def(pattern.id,
2651 FoundStructOrEnumVariant(..) => {
2655 ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(
2658 self.record_def(pattern.id, err_path_resolution());
2660 FoundConst(def, lp, _) if const_ok => {
2661 debug!("(resolving pattern) resolving `{}` to constant", renamed);
2663 self.enforce_default_binding_mode(pattern, binding_mode, "a constant");
2664 self.record_def(pattern.id,
2671 FoundConst(def, _, name) => {
2675 ResolutionError::OnlyIrrefutablePatternsAllowedHere(def.def_id(),
2678 self.record_def(pattern.id, err_path_resolution());
2680 BareIdentifierPatternUnresolved => {
2681 debug!("(resolving pattern) binding `{}`", renamed);
2683 let def_id = self.ast_map.local_def_id(pattern.id);
2684 let def = Def::Local(def_id, pattern.id);
2686 // Record the definition so that later passes
2687 // will be able to distinguish variants from
2688 // locals in patterns.
2690 self.record_def(pattern.id,
2693 last_private: LastMod(AllPublic),
2697 // Add the binding to the local ribs, if it
2698 // doesn't already exist in the bindings list. (We
2699 // must not add it if it's in the bindings list
2700 // because that breaks the assumptions later
2701 // passes make about or-patterns.)
2702 if !bindings_list.contains_key(&renamed) {
2703 let this = &mut *self;
2704 let last_rib = this.value_ribs.last_mut().unwrap();
2705 last_rib.bindings.insert(renamed, DlDef(def));
2706 bindings_list.insert(renamed, pat_id);
2707 } else if mode == ArgumentIrrefutableMode &&
2708 bindings_list.contains_key(&renamed) {
2709 // Forbid duplicate bindings in the same
2714 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2715 &ident.name.as_str())
2717 } else if bindings_list.get(&renamed) == Some(&pat_id) {
2718 // Then this is a duplicate variable in the
2719 // same disjunction, which is an error.
2723 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2724 &ident.name.as_str())
2727 // Else, not bound in the same pattern: do
2733 PatEnum(ref path, _) => {
2734 // This must be an enum variant, struct or const.
2735 let resolution = match self.resolve_possibly_assoc_item(pat_id,
2740 // The below shouldn't happen because all
2741 // qualified paths should be in PatQPath.
2742 TypecheckRequired =>
2743 self.session.span_bug(path.span,
2744 "resolve_possibly_assoc_item claimed
2746 that a path in PatEnum requires typecheck
2748 to resolve, but qualified paths should be
2751 ResolveAttempt(resolution) => resolution,
2753 if let Some(path_res) = resolution {
2754 match path_res.base_def {
2755 Def::Struct(..) if path_res.depth == 0 => {
2756 self.record_def(pattern.id, path_res);
2758 Def::Variant(..) | Def::Const(..) => {
2759 self.record_def(pattern.id, path_res);
2761 Def::Static(..) => {
2762 resolve_error(&self,
2764 ResolutionError::StaticVariableReference);
2765 self.record_def(pattern.id, err_path_resolution());
2768 // If anything ends up here entirely resolved,
2769 // it's an error. If anything ends up here
2770 // partially resolved, that's OK, because it may
2771 // be a `T::CONST` that typeck will resolve.
2772 if path_res.depth == 0 {
2776 ResolutionError::NotAnEnumVariantStructOrConst(
2784 self.record_def(pattern.id, err_path_resolution());
2786 let const_name = path.segments
2791 let traits = self.get_traits_containing_item(const_name);
2792 self.trait_map.insert(pattern.id, traits);
2793 self.record_def(pattern.id, path_res);
2801 ResolutionError::UnresolvedEnumVariantStructOrConst(
2802 &path.segments.last().unwrap().identifier.name.as_str())
2804 self.record_def(pattern.id, err_path_resolution());
2806 intravisit::walk_path(self, path);
2809 PatQPath(ref qself, ref path) => {
2810 // Associated constants only.
2811 let resolution = match self.resolve_possibly_assoc_item(pat_id,
2816 TypecheckRequired => {
2817 // All `<T>::CONST` should end up here, and will
2818 // require use of the trait map to resolve
2819 // during typechecking.
2820 let const_name = path.segments
2825 let traits = self.get_traits_containing_item(const_name);
2826 self.trait_map.insert(pattern.id, traits);
2827 intravisit::walk_pat(self, pattern);
2830 ResolveAttempt(resolution) => resolution,
2832 if let Some(path_res) = resolution {
2833 match path_res.base_def {
2834 // All `<T as Trait>::CONST` should end up here, and
2835 // have the trait already selected.
2836 Def::AssociatedConst(..) => {
2837 self.record_def(pattern.id, path_res);
2843 ResolutionError::NotAnAssociatedConst(
2844 &path.segments.last().unwrap().identifier.name.as_str()
2847 self.record_def(pattern.id, err_path_resolution());
2853 ResolutionError::UnresolvedAssociatedConst(&path.segments
2859 self.record_def(pattern.id, err_path_resolution());
2861 intravisit::walk_pat(self, pattern);
2864 PatStruct(ref path, _, _) => {
2865 match self.resolve_path(pat_id, path, 0, TypeNS, false) {
2866 Some(definition) => {
2867 self.record_def(pattern.id, definition);
2870 debug!("(resolving pattern) didn't find struct def: {:?}", result);
2874 ResolutionError::DoesNotNameAStruct(
2875 &*path_names_to_string(path, 0))
2877 self.record_def(pattern.id, err_path_resolution());
2880 intravisit::walk_path(self, path);
2883 PatLit(_) | PatRange(..) => {
2884 intravisit::walk_pat(self, pattern);
2895 fn resolve_bare_identifier_pattern(&mut self,
2898 -> BareIdentifierPatternResolution {
2899 let module = self.current_module;
2900 match self.resolve_item_in_lexical_scope(module, name, ValueNS, true) {
2901 Success((target, _)) => {
2902 debug!("(resolve bare identifier pattern) succeeded in finding {} at {:?}",
2904 target.binding.borrow());
2905 match target.binding.def() {
2907 panic!("resolved name in the value namespace to a set of name bindings \
2910 // For the two success cases, this lookup can be
2911 // considered as not having a private component because
2912 // the lookup happened only within the current module.
2913 Some(def @ Def::Variant(..)) | Some(def @ Def::Struct(..)) => {
2914 return FoundStructOrEnumVariant(def, LastMod(AllPublic));
2916 Some(def @ Def::Const(..)) | Some(def @ Def::AssociatedConst(..)) => {
2917 return FoundConst(def, LastMod(AllPublic), name);
2919 Some(Def::Static(..)) => {
2920 resolve_error(self, span, ResolutionError::StaticVariableReference);
2921 return BareIdentifierPatternUnresolved;
2923 _ => return BareIdentifierPatternUnresolved
2928 panic!("unexpected indeterminate result");
2932 Some((span, msg)) => {
2933 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
2938 debug!("(resolve bare identifier pattern) failed to find {}", name);
2939 return BareIdentifierPatternUnresolved;
2944 /// Handles paths that may refer to associated items
2945 fn resolve_possibly_assoc_item(&mut self,
2947 maybe_qself: Option<&hir::QSelf>,
2949 namespace: Namespace,
2951 -> AssocItemResolveResult {
2952 let max_assoc_types;
2956 if qself.position == 0 {
2957 return TypecheckRequired;
2959 max_assoc_types = path.segments.len() - qself.position;
2960 // Make sure the trait is valid.
2961 let _ = self.resolve_trait_reference(id, path, max_assoc_types);
2964 max_assoc_types = path.segments.len();
2968 let mut resolution = self.with_no_errors(|this| {
2969 this.resolve_path(id, path, 0, namespace, check_ribs)
2971 for depth in 1..max_assoc_types {
2972 if resolution.is_some() {
2975 self.with_no_errors(|this| {
2976 resolution = this.resolve_path(id, path, depth, TypeNS, true);
2979 if let Some(Def::Mod(_)) = resolution.map(|r| r.base_def) {
2980 // A module is not a valid type or value.
2983 ResolveAttempt(resolution)
2986 /// If `check_ribs` is true, checks the local definitions first; i.e.
2987 /// doesn't skip straight to the containing module.
2988 /// Skips `path_depth` trailing segments, which is also reflected in the
2989 /// returned value. See `middle::def::PathResolution` for more info.
2990 pub fn resolve_path(&mut self,
2994 namespace: Namespace,
2996 -> Option<PathResolution> {
2997 let span = path.span;
2998 let segments = &path.segments[..path.segments.len() - path_depth];
3000 let mk_res = |(def, lp)| PathResolution::new(def, lp, path_depth);
3003 let def = self.resolve_crate_relative_path(span, segments, namespace);
3004 return def.map(mk_res);
3007 // Try to find a path to an item in a module.
3008 let last_ident = segments.last().unwrap().identifier;
3009 if segments.len() <= 1 {
3010 let unqualified_def = self.resolve_identifier(last_ident, namespace, check_ribs, true);
3011 return unqualified_def.and_then(|def| self.adjust_local_def(def, span))
3013 PathResolution::new(def, LastMod(AllPublic), path_depth)
3017 let unqualified_def = self.resolve_identifier(last_ident, namespace, check_ribs, false);
3018 let def = self.resolve_module_relative_path(span, segments, namespace);
3019 match (def, unqualified_def) {
3020 (Some((ref d, _)), Some(ref ud)) if *d == ud.def => {
3022 .add_lint(lint::builtin::UNUSED_QUALIFICATIONS,
3025 "unnecessary qualification".to_string());
3033 // Resolve a single identifier
3034 fn resolve_identifier(&mut self,
3035 identifier: hir::Ident,
3036 namespace: Namespace,
3039 -> Option<LocalDef> {
3040 // First, check to see whether the name is a primitive type.
3041 if namespace == TypeNS {
3042 if let Some(&prim_ty) = self.primitive_type_table
3044 .get(&identifier.unhygienic_name) {
3045 return Some(LocalDef::from_def(Def::PrimTy(prim_ty)));
3050 if let Some(def) = self.resolve_identifier_in_local_ribs(identifier, namespace) {
3055 let name = identifier.unhygienic_name;
3056 self.resolve_item_by_name_in_lexical_scope(name, namespace, record_used)
3057 .map(LocalDef::from_def)
3060 // Resolve a local definition, potentially adjusting for closures.
3061 fn adjust_local_def(&mut self, local_def: LocalDef, span: Span) -> Option<Def> {
3062 let ribs = match local_def.ribs {
3063 Some((TypeNS, i)) => &self.type_ribs[i + 1..],
3064 Some((ValueNS, i)) => &self.value_ribs[i + 1..],
3067 let mut def = local_def.def;
3070 self.session.span_bug(span, &format!("unexpected {:?} in bindings", def))
3072 Def::Local(_, node_id) => {
3076 // Nothing to do. Continue.
3078 ClosureRibKind(function_id) => {
3080 let node_def_id = self.ast_map.local_def_id(node_id);
3082 let seen = self.freevars_seen
3084 .or_insert_with(|| NodeMap());
3085 if let Some(&index) = seen.get(&node_id) {
3086 def = Def::Upvar(node_def_id, node_id, index, function_id);
3089 let vec = self.freevars
3091 .or_insert_with(|| vec![]);
3092 let depth = vec.len();
3098 def = Def::Upvar(node_def_id, node_id, depth, function_id);
3099 seen.insert(node_id, depth);
3101 ItemRibKind | MethodRibKind => {
3102 // This was an attempt to access an upvar inside a
3103 // named function item. This is not allowed, so we
3107 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
3110 ConstantItemRibKind => {
3111 // Still doesn't deal with upvars
3114 ResolutionError::AttemptToUseNonConstantValueInConstant);
3120 Def::TyParam(..) | Def::SelfTy(..) => {
3123 NormalRibKind | MethodRibKind | ClosureRibKind(..) => {
3124 // Nothing to do. Continue.
3127 // This was an attempt to use a type parameter outside
3132 ResolutionError::TypeParametersFromOuterFunction);
3135 ConstantItemRibKind => {
3137 resolve_error(self, span, ResolutionError::OuterTypeParameterContext);
3148 // resolve a "module-relative" path, e.g. a::b::c
3149 fn resolve_module_relative_path(&mut self,
3151 segments: &[hir::PathSegment],
3152 namespace: Namespace)
3153 -> Option<(Def, LastPrivate)> {
3154 let module_path = segments.split_last()
3158 .map(|ps| ps.identifier.name)
3159 .collect::<Vec<_>>();
3161 let containing_module;
3163 let current_module = self.current_module;
3164 match self.resolve_module_path(current_module,
3170 let (span, msg) = match err {
3171 Some((span, msg)) => (span, msg),
3173 let msg = format!("Use of undeclared type or module `{}`",
3174 names_to_string(&module_path));
3179 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3182 Indeterminate => panic!("indeterminate unexpected"),
3183 Success((resulting_module, resulting_last_private)) => {
3184 containing_module = resulting_module;
3185 last_private = resulting_last_private;
3189 let name = segments.last().unwrap().identifier.name;
3190 let def = match self.resolve_name_in_module(containing_module,
3193 NameSearchType::PathSearch,
3195 Success((Target { binding, .. }, _)) => {
3196 let (def, lp) = binding.def_and_lp();
3197 (def, last_private.or(lp))
3201 if let Some(DefId{krate: kid, ..}) = containing_module.def_id() {
3202 self.used_crates.insert(kid);
3207 /// Invariant: This must be called only during main resolution, not during
3208 /// import resolution.
3209 fn resolve_crate_relative_path(&mut self,
3211 segments: &[hir::PathSegment],
3212 namespace: Namespace)
3213 -> Option<(Def, LastPrivate)> {
3214 let module_path = segments.split_last()
3218 .map(|ps| ps.identifier.name)
3219 .collect::<Vec<_>>();
3221 let root_module = self.graph_root;
3223 let containing_module;
3225 match self.resolve_module_path_from_root(root_module,
3230 LastMod(AllPublic)) {
3232 let (span, msg) = match err {
3233 Some((span, msg)) => (span, msg),
3235 let msg = format!("Use of undeclared module `::{}`",
3236 names_to_string(&module_path[..]));
3241 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3246 panic!("indeterminate unexpected");
3249 Success((resulting_module, resulting_last_private)) => {
3250 containing_module = resulting_module;
3251 last_private = resulting_last_private;
3255 let name = segments.last().unwrap().identifier.name;
3256 match self.resolve_name_in_module(containing_module,
3259 NameSearchType::PathSearch,
3261 Success((Target { binding, .. }, _)) => {
3262 let (def, lp) = binding.def_and_lp();
3263 Some((def, last_private.or(lp)))
3269 fn resolve_identifier_in_local_ribs(&mut self,
3271 namespace: Namespace)
3272 -> Option<LocalDef> {
3273 // Check the local set of ribs.
3274 let (name, ribs) = match namespace {
3275 ValueNS => (ident.name, &self.value_ribs),
3276 TypeNS => (ident.unhygienic_name, &self.type_ribs),
3279 for (i, rib) in ribs.iter().enumerate().rev() {
3280 if let Some(def_like) = rib.bindings.get(&name).cloned() {
3283 debug!("(resolving path in local ribs) resolved `{}` to {:?} at {}",
3287 return Some(LocalDef {
3288 ribs: Some((namespace, i)),
3293 debug!("(resolving path in local ribs) resolved `{}` to pseudo-def {:?}",
3305 fn resolve_item_by_name_in_lexical_scope(&mut self,
3307 namespace: Namespace,
3311 let module = self.current_module;
3312 match self.resolve_item_in_lexical_scope(module, name, namespace, record_used) {
3313 Success((target, _)) => {
3314 match target.binding.def() {
3316 // This can happen if we were looking for a type and
3317 // found a module instead. Modules don't have defs.
3318 debug!("(resolving item path by identifier in lexical scope) failed to \
3319 resolve {} after success...",
3324 debug!("(resolving item path in lexical scope) resolved `{}` to item",
3326 // This lookup is "all public" because it only searched
3327 // for one identifier in the current module (couldn't
3328 // have passed through reexports or anything like that.
3334 panic!("unexpected indeterminate result");
3337 debug!("(resolving item path by identifier in lexical scope) failed to resolve {}",
3340 if let Some((span, msg)) = err {
3341 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg))
3349 fn with_no_errors<T, F>(&mut self, f: F) -> T
3350 where F: FnOnce(&mut Resolver) -> T
3352 self.emit_errors = false;
3354 self.emit_errors = true;
3358 fn find_fallback_in_self_type(&mut self, name: Name) -> FallbackSuggestion {
3359 fn extract_path_and_node_id(t: &Ty,
3360 allow: FallbackChecks)
3361 -> Option<(Path, NodeId, FallbackChecks)> {
3363 TyPath(None, ref path) => Some((path.clone(), t.id, allow)),
3364 TyPtr(ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, OnlyTraitAndStatics),
3365 TyRptr(_, ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, allow),
3366 // This doesn't handle the remaining `Ty` variants as they are not
3367 // that commonly the self_type, it might be interesting to provide
3368 // support for those in future.
3373 fn get_module<'a, 'tcx>(this: &mut Resolver<'a, 'tcx>,
3375 name_path: &[ast::Name])
3376 -> Option<Module<'a>> {
3377 let root = this.current_module;
3378 let last_name = name_path.last().unwrap();
3380 if name_path.len() == 1 {
3381 match this.primitive_type_table.primitive_types.get(last_name) {
3384 match this.current_module.children.borrow().get(last_name) {
3385 Some(child) => child.type_ns.module(),
3391 match this.resolve_module_path(root,
3396 Success((module, _)) => Some(module),
3402 fn is_static_method(this: &Resolver, did: DefId) -> bool {
3403 if let Some(node_id) = this.ast_map.as_local_node_id(did) {
3404 let sig = match this.ast_map.get(node_id) {
3405 hir_map::NodeTraitItem(trait_item) => match trait_item.node {
3406 hir::MethodTraitItem(ref sig, _) => sig,
3409 hir_map::NodeImplItem(impl_item) => match impl_item.node {
3410 hir::ImplItemKind::Method(ref sig, _) => sig,
3415 sig.explicit_self.node == hir::SelfStatic
3417 this.session.cstore.is_static_method(did)
3421 let (path, node_id, allowed) = match self.current_self_type {
3422 Some(ref ty) => match extract_path_and_node_id(ty, Everything) {
3424 None => return NoSuggestion,
3426 None => return NoSuggestion,
3429 if allowed == Everything {
3430 // Look for a field with the same name in the current self_type.
3431 match self.def_map.borrow().get(&node_id).map(|d| d.full_def()) {
3432 Some(Def::Enum(did)) |
3433 Some(Def::TyAlias(did)) |
3434 Some(Def::Struct(did)) |
3435 Some(Def::Variant(_, did)) => match self.structs.get(&did) {
3438 if fields.iter().any(|&field_name| name == field_name) {
3443 _ => {} // Self type didn't resolve properly
3447 let name_path = path.segments.iter().map(|seg| seg.identifier.name).collect::<Vec<_>>();
3449 // Look for a method in the current self type's impl module.
3450 if let Some(module) = get_module(self, path.span, &name_path) {
3451 if let Some(binding) = module.children.borrow().get(&name) {
3452 if let Some(Def::Method(did)) = binding.value_ns.def() {
3453 if is_static_method(self, did) {
3454 return StaticMethod(path_names_to_string(&path, 0));
3456 if self.current_trait_ref.is_some() {
3458 } else if allowed == Everything {
3465 // Look for a method in the current trait.
3466 if let Some((trait_did, ref trait_ref)) = self.current_trait_ref {
3467 if let Some(&did) = self.trait_item_map.get(&(name, trait_did)) {
3468 if is_static_method(self, did) {
3469 return TraitMethod(path_names_to_string(&trait_ref.path, 0));
3479 fn find_best_match(&mut self, name: &str) -> SuggestionType {
3480 if let Some(macro_name) = self.session.available_macros
3481 .borrow().iter().find(|n| n.as_str() == name) {
3482 return SuggestionType::Macro(format!("{}!", macro_name));
3485 let names = self.value_ribs
3488 .flat_map(|rib| rib.bindings.keys());
3490 if let Some(found) = find_best_match_for_name(names, name, None) {
3491 if name != &*found {
3492 return SuggestionType::Function(found);
3494 } SuggestionType::NotFound
3497 fn resolve_expr(&mut self, expr: &Expr) {
3498 // First, record candidate traits for this expression if it could
3499 // result in the invocation of a method call.
3501 self.record_candidate_traits_for_expr_if_necessary(expr);
3503 // Next, resolve the node.
3505 ExprPath(ref maybe_qself, ref path) => {
3506 let resolution = match self.resolve_possibly_assoc_item(expr.id,
3507 maybe_qself.as_ref(),
3511 // `<T>::a::b::c` is resolved by typeck alone.
3512 TypecheckRequired => {
3513 let method_name = path.segments.last().unwrap().identifier.name;
3514 let traits = self.get_traits_containing_item(method_name);
3515 self.trait_map.insert(expr.id, traits);
3516 intravisit::walk_expr(self, expr);
3519 ResolveAttempt(resolution) => resolution,
3522 // This is a local path in the value namespace. Walk through
3523 // scopes looking for it.
3524 if let Some(path_res) = resolution {
3525 // Check if struct variant
3526 let is_struct_variant = if let Def::Variant(_, variant_id) = path_res.base_def {
3527 self.structs.contains_key(&variant_id)
3531 if is_struct_variant {
3532 let _ = self.structs.contains_key(&path_res.base_def.def_id());
3533 let path_name = path_names_to_string(path, 0);
3535 let mut err = resolve_struct_error(self,
3537 ResolutionError::StructVariantUsedAsFunction(&*path_name));
3539 let msg = format!("did you mean to write: `{} {{ /* fields */ }}`?",
3541 if self.emit_errors {
3542 err.fileline_help(expr.span, &msg);
3544 err.span_help(expr.span, &msg);
3547 self.record_def(expr.id, err_path_resolution());
3549 // Write the result into the def map.
3550 debug!("(resolving expr) resolved `{}`",
3551 path_names_to_string(path, 0));
3553 // Partial resolutions will need the set of traits in scope,
3554 // so they can be completed during typeck.
3555 if path_res.depth != 0 {
3556 let method_name = path.segments.last().unwrap().identifier.name;
3557 let traits = self.get_traits_containing_item(method_name);
3558 self.trait_map.insert(expr.id, traits);
3561 self.record_def(expr.id, path_res);
3564 // Be helpful if the name refers to a struct
3565 // (The pattern matching def_tys where the id is in self.structs
3566 // matches on regular structs while excluding tuple- and enum-like
3567 // structs, which wouldn't result in this error.)
3568 let path_name = path_names_to_string(path, 0);
3569 let type_res = self.with_no_errors(|this| {
3570 this.resolve_path(expr.id, path, 0, TypeNS, false)
3573 self.record_def(expr.id, err_path_resolution());
3574 match type_res.map(|r| r.base_def) {
3575 Some(Def::Struct(..)) => {
3576 let mut err = resolve_struct_error(self,
3578 ResolutionError::StructVariantUsedAsFunction(&*path_name));
3580 let msg = format!("did you mean to write: `{} {{ /* fields */ }}`?",
3582 if self.emit_errors {
3583 err.fileline_help(expr.span, &msg);
3585 err.span_help(expr.span, &msg);
3590 // Keep reporting some errors even if they're ignored above.
3591 self.resolve_path(expr.id, path, 0, ValueNS, true);
3593 let mut method_scope = false;
3594 self.value_ribs.iter().rev().all(|rib| {
3595 method_scope = match rib.kind {
3596 MethodRibKind => true,
3597 ItemRibKind | ConstantItemRibKind => false,
3598 _ => return true, // Keep advancing
3600 false // Stop advancing
3603 if method_scope && special_names::self_.as_str() == &path_name[..] {
3606 ResolutionError::SelfNotAvailableInStaticMethod);
3608 let last_name = path.segments.last().unwrap().identifier.name;
3609 let mut msg = match self.find_fallback_in_self_type(last_name) {
3611 // limit search to 5 to reduce the number
3612 // of stupid suggestions
3613 match self.find_best_match(&path_name) {
3614 SuggestionType::Macro(s) => {
3615 format!("the macro `{}`", s)
3617 SuggestionType::Function(s) => format!("`{}`", s),
3618 SuggestionType::NotFound => "".to_string(),
3621 Field => format!("`self.{}`", path_name),
3623 TraitItem => format!("to call `self.{}`", path_name),
3624 TraitMethod(path_str) |
3625 StaticMethod(path_str) =>
3626 format!("to call `{}::{}`", path_str, path_name),
3629 let mut context = UnresolvedNameContext::Other;
3630 if !msg.is_empty() {
3631 msg = format!(". Did you mean {}?", msg);
3633 // we check if this a module and if so, we display a help
3635 let name_path = path.segments.iter()
3636 .map(|seg| seg.identifier.name)
3637 .collect::<Vec<_>>();
3638 let current_module = self.current_module;
3640 match self.resolve_module_path(current_module,
3646 context = UnresolvedNameContext::PathIsMod(expr.id);
3654 ResolutionError::UnresolvedName(
3655 &*path_name, &*msg, context));
3661 intravisit::walk_expr(self, expr);
3664 ExprStruct(ref path, _, _) => {
3665 // Resolve the path to the structure it goes to. We don't
3666 // check to ensure that the path is actually a structure; that
3667 // is checked later during typeck.
3668 match self.resolve_path(expr.id, path, 0, TypeNS, false) {
3669 Some(definition) => self.record_def(expr.id, definition),
3671 debug!("(resolving expression) didn't find struct def",);
3675 ResolutionError::DoesNotNameAStruct(
3676 &*path_names_to_string(path, 0))
3678 self.record_def(expr.id, err_path_resolution());
3682 intravisit::walk_expr(self, expr);
3685 ExprLoop(_, Some(label)) | ExprWhile(_, _, Some(label)) => {
3686 self.with_label_rib(|this| {
3687 let def_like = DlDef(Def::Label(expr.id));
3690 let rib = this.label_ribs.last_mut().unwrap();
3691 rib.bindings.insert(label.name, def_like);
3694 intravisit::walk_expr(this, expr);
3698 ExprBreak(Some(label)) | ExprAgain(Some(label)) => {
3699 match self.search_label(label.node.name) {
3701 self.record_def(expr.id, err_path_resolution());
3704 ResolutionError::UndeclaredLabel(&label.node.name.as_str()))
3706 Some(DlDef(def @ Def::Label(_))) => {
3707 // Since this def is a label, it is never read.
3708 self.record_def(expr.id,
3711 last_private: LastMod(AllPublic),
3716 self.session.span_bug(expr.span, "label wasn't mapped to a label def!")
3722 intravisit::walk_expr(self, expr);
3727 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3729 ExprField(_, name) => {
3730 // FIXME(#6890): Even though you can't treat a method like a
3731 // field, we need to add any trait methods we find that match
3732 // the field name so that we can do some nice error reporting
3733 // later on in typeck.
3734 let traits = self.get_traits_containing_item(name.node);
3735 self.trait_map.insert(expr.id, traits);
3737 ExprMethodCall(name, _, _) => {
3738 debug!("(recording candidate traits for expr) recording traits for {}",
3740 let traits = self.get_traits_containing_item(name.node);
3741 self.trait_map.insert(expr.id, traits);
3749 fn get_traits_containing_item(&mut self, name: Name) -> Vec<DefId> {
3750 debug!("(getting traits containing item) looking for '{}'", name);
3752 fn add_trait_info(found_traits: &mut Vec<DefId>, trait_def_id: DefId, name: Name) {
3753 debug!("(adding trait info) found trait {:?} for method '{}'",
3756 found_traits.push(trait_def_id);
3759 let mut found_traits = Vec::new();
3760 let mut search_module = self.current_module;
3762 // Look for the current trait.
3763 match self.current_trait_ref {
3764 Some((trait_def_id, _)) => {
3765 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3766 add_trait_info(&mut found_traits, trait_def_id, name);
3769 None => {} // Nothing to do.
3772 // Look for trait children.
3773 build_reduced_graph::populate_module_if_necessary(self, &search_module);
3776 for (_, child_names) in search_module.children.borrow().iter() {
3777 let def = match child_names.type_ns.def() {
3781 let trait_def_id = match def {
3782 Def::Trait(trait_def_id) => trait_def_id,
3785 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3786 add_trait_info(&mut found_traits, trait_def_id, name);
3791 // Look for imports.
3792 for (_, import) in search_module.import_resolutions.borrow().iter() {
3793 let target = match import.type_ns.target {
3795 Some(ref target) => target,
3797 let did = match target.binding.def() {
3798 Some(Def::Trait(trait_def_id)) => trait_def_id,
3799 Some(..) | None => continue,
3801 if self.trait_item_map.contains_key(&(name, did)) {
3802 add_trait_info(&mut found_traits, did, name);
3803 let id = import.type_ns.id;
3804 self.used_imports.insert((id, TypeNS));
3805 let trait_name = self.get_trait_name(did);
3806 self.record_import_use(id, trait_name);
3807 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id() {
3808 self.used_crates.insert(kid);
3813 match search_module.parent_link {
3814 NoParentLink | ModuleParentLink(..) => break,
3815 BlockParentLink(parent_module, _) => {
3816 search_module = parent_module;
3824 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
3825 debug!("(recording def) recording {:?} for {}", resolution, node_id);
3826 assert!(match resolution.last_private {
3827 LastImport{..} => false,
3830 "Import should only be used for `use` directives");
3832 if let Some(prev_res) = self.def_map.borrow_mut().insert(node_id, resolution) {
3833 let span = self.ast_map.opt_span(node_id).unwrap_or(codemap::DUMMY_SP);
3834 self.session.span_bug(span,
3835 &format!("path resolved multiple times ({:?} before, {:?} now)",
3841 fn enforce_default_binding_mode(&mut self,
3843 pat_binding_mode: BindingMode,
3845 match pat_binding_mode {
3846 BindByValue(_) => {}
3850 ResolutionError::CannotUseRefBindingModeWith(descr));
3858 // Diagnostics are not particularly efficient, because they're rarely
3862 #[allow(dead_code)] // useful for debugging
3863 fn dump_module(&mut self, module_: Module<'a>) {
3864 debug!("Dump of module `{}`:", module_to_string(&*module_));
3866 debug!("Children:");
3867 build_reduced_graph::populate_module_if_necessary(self, &module_);
3868 for (&name, _) in module_.children.borrow().iter() {
3869 debug!("* {}", name);
3872 debug!("Import resolutions:");
3873 let import_resolutions = module_.import_resolutions.borrow();
3874 for (&name, import_resolution) in import_resolutions.iter() {
3876 match import_resolution.value_ns.target {
3878 value_repr = "".to_string();
3881 value_repr = " value:?".to_string();
3887 match import_resolution.type_ns.target {
3889 type_repr = "".to_string();
3892 type_repr = " type:?".to_string();
3897 debug!("* {}:{}{}", name, value_repr, type_repr);
3903 fn names_to_string(names: &[Name]) -> String {
3904 let mut first = true;
3905 let mut result = String::new();
3910 result.push_str("::")
3912 result.push_str(&name.as_str());
3917 fn path_names_to_string(path: &Path, depth: usize) -> String {
3918 let names: Vec<ast::Name> = path.segments[..path.segments.len() - depth]
3920 .map(|seg| seg.identifier.name)
3922 names_to_string(&names[..])
3925 /// A somewhat inefficient routine to obtain the name of a module.
3926 fn module_to_string<'a>(module: Module<'a>) -> String {
3927 let mut names = Vec::new();
3929 fn collect_mod<'a>(names: &mut Vec<ast::Name>, module: Module<'a>) {
3930 match module.parent_link {
3932 ModuleParentLink(ref module, name) => {
3934 collect_mod(names, module);
3936 BlockParentLink(ref module, _) => {
3937 // danger, shouldn't be ident?
3938 names.push(special_idents::opaque.name);
3939 collect_mod(names, module);
3943 collect_mod(&mut names, module);
3945 if names.is_empty() {
3946 return "???".to_string();
3948 names_to_string(&names.into_iter().rev().collect::<Vec<ast::Name>>())
3951 fn err_path_resolution() -> PathResolution {
3954 last_private: LastMod(AllPublic),
3960 pub struct CrateMap {
3961 pub def_map: RefCell<DefMap>,
3962 pub freevars: FreevarMap,
3963 pub export_map: ExportMap,
3964 pub trait_map: TraitMap,
3965 pub external_exports: ExternalExports,
3966 pub glob_map: Option<GlobMap>,
3969 #[derive(PartialEq,Copy, Clone)]
3970 pub enum MakeGlobMap {
3975 /// Entry point to crate resolution.
3976 pub fn resolve_crate<'a, 'tcx>(session: &'a Session,
3977 ast_map: &'a hir_map::Map<'tcx>,
3978 make_glob_map: MakeGlobMap)
3980 let krate = ast_map.krate();
3981 let arenas = Resolver::arenas();
3982 let mut resolver = create_resolver(session, ast_map, krate, make_glob_map, &arenas, None);
3984 resolver.resolve_crate(krate);
3986 check_unused::check_crate(&mut resolver, krate);
3989 def_map: resolver.def_map,
3990 freevars: resolver.freevars,
3991 export_map: resolver.export_map,
3992 trait_map: resolver.trait_map,
3993 external_exports: resolver.external_exports,
3994 glob_map: if resolver.make_glob_map {
3995 Some(resolver.glob_map)
4002 /// Builds a name resolution walker to be used within this module,
4003 /// or used externally, with an optional callback function.
4005 /// The callback takes a &mut bool which allows callbacks to end a
4006 /// walk when set to true, passing through the rest of the walk, while
4007 /// preserving the ribs + current module. This allows resolve_path
4008 /// calls to be made with the correct scope info. The node in the
4009 /// callback corresponds to the current node in the walk.
4010 pub fn create_resolver<'a, 'tcx>(session: &'a Session,
4011 ast_map: &'a hir_map::Map<'tcx>,
4013 make_glob_map: MakeGlobMap,
4014 arenas: &'a ResolverArenas<'a>,
4015 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>)
4016 -> Resolver<'a, 'tcx> {
4017 let mut resolver = Resolver::new(session, ast_map, make_glob_map, arenas);
4019 resolver.callback = callback;
4021 build_reduced_graph::build_reduced_graph(&mut resolver, krate);
4022 session.abort_if_errors();
4024 resolve_imports::resolve_imports(&mut resolver);
4025 session.abort_if_errors();
4030 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }