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/")]
18 #![cfg_attr(not(stage0), deny(warnings))]
20 #![feature(associated_consts)]
21 #![feature(borrow_state)]
22 #![feature(rustc_diagnostic_macros)]
23 #![feature(rustc_private)]
24 #![feature(staged_api)]
33 extern crate rustc_bitflags;
34 extern crate rustc_front;
37 use self::PatternBindingMode::*;
38 use self::Namespace::*;
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::BareIdentifierPatternResolution::*;
47 use self::ParentLink::*;
48 use self::FallbackChecks::*;
50 use rustc::dep_graph::DepNode;
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};
63 use syntax::ast::{self, FloatTy};
64 use syntax::ast::{CRATE_NODE_ID, Name, NodeId, CrateNum, IntTy, UintTy};
65 use syntax::attr::AttrMetaMethods;
66 use syntax::codemap::{self, Span, Pos};
67 use syntax::errors::DiagnosticBuilder;
68 use syntax::parse::token::{self, special_names, special_idents};
69 use syntax::util::lev_distance::find_best_match_for_name;
71 use rustc_front::intravisit::{self, FnKind, Visitor};
73 use rustc_front::hir::{Arm, BindByRef, BindByValue, BindingMode, Block};
74 use rustc_front::hir::Crate;
75 use rustc_front::hir::{Expr, ExprAgain, ExprBreak, ExprCall, ExprField};
76 use rustc_front::hir::{ExprLoop, ExprWhile, ExprMethodCall};
77 use rustc_front::hir::{ExprPath, ExprStruct, FnDecl};
78 use rustc_front::hir::{ForeignItemFn, ForeignItemStatic, Generics};
79 use rustc_front::hir::{ImplItem, Item, ItemConst, ItemEnum, ItemExternCrate};
80 use rustc_front::hir::{ItemFn, ItemForeignMod, ItemImpl, ItemMod, ItemStatic, ItemDefaultImpl};
81 use rustc_front::hir::{ItemStruct, ItemTrait, ItemTy, ItemUse};
82 use rustc_front::hir::Local;
83 use rustc_front::hir::{Pat, PatKind, Path, PrimTy};
84 use rustc_front::hir::{TraitRef, Ty, TyBool, TyChar, TyFloat, TyInt};
85 use rustc_front::hir::{TyRptr, TyStr, TyUint, TyPath, TyPtr};
86 use rustc_front::util::walk_pat;
88 use std::collections::{HashMap, HashSet};
89 use std::cell::{Cell, RefCell};
91 use std::mem::replace;
93 use resolve_imports::{ImportDirective, NameResolution};
95 // NB: This module needs to be declared first so diagnostics are
96 // registered before they are used.
100 mod build_reduced_graph;
103 // Perform the callback, not walking deeper if the return is true
104 macro_rules! execute_callback {
105 ($node: expr, $walker: expr) => (
106 if let Some(ref callback) = $walker.callback {
107 if callback($node, &mut $walker.resolved) {
114 enum SuggestionType {
116 Function(token::InternedString),
120 pub enum ResolutionError<'a> {
121 /// error E0401: can't use type parameters from outer function
122 TypeParametersFromOuterFunction,
123 /// error E0402: cannot use an outer type parameter in this context
124 OuterTypeParameterContext,
125 /// error E0403: the name is already used for a type parameter in this type parameter list
126 NameAlreadyUsedInTypeParameterList(Name),
127 /// error E0404: is not a trait
128 IsNotATrait(&'a str),
129 /// error E0405: use of undeclared trait name
130 UndeclaredTraitName(&'a str),
131 /// error E0406: undeclared associated type
132 UndeclaredAssociatedType,
133 /// error E0407: method is not a member of trait
134 MethodNotMemberOfTrait(Name, &'a str),
135 /// error E0437: type is not a member of trait
136 TypeNotMemberOfTrait(Name, &'a str),
137 /// error E0438: const is not a member of trait
138 ConstNotMemberOfTrait(Name, &'a str),
139 /// error E0408: variable `{}` from pattern #1 is not bound in pattern
140 VariableNotBoundInPattern(Name, usize),
141 /// error E0409: variable is bound with different mode in pattern #{} than in pattern #1
142 VariableBoundWithDifferentMode(Name, usize),
143 /// error E0410: variable from pattern is not bound in pattern #1
144 VariableNotBoundInParentPattern(Name, usize),
145 /// error E0411: use of `Self` outside of an impl or trait
146 SelfUsedOutsideImplOrTrait,
147 /// error E0412: use of undeclared
148 UseOfUndeclared(&'a str, &'a str),
149 /// error E0413: declaration shadows an enum variant or unit-like struct in scope
150 DeclarationShadowsEnumVariantOrUnitLikeStruct(Name),
151 /// error E0414: only irrefutable patterns allowed here
152 OnlyIrrefutablePatternsAllowedHere(DefId, Name),
153 /// error E0415: identifier is bound more than once in this parameter list
154 IdentifierBoundMoreThanOnceInParameterList(&'a str),
155 /// error E0416: identifier is bound more than once in the same pattern
156 IdentifierBoundMoreThanOnceInSamePattern(&'a str),
157 /// error E0417: static variables cannot be referenced in a pattern
158 StaticVariableReference,
159 /// error E0418: is not an enum variant, struct or const
160 NotAnEnumVariantStructOrConst(&'a str),
161 /// error E0419: unresolved enum variant, struct or const
162 UnresolvedEnumVariantStructOrConst(&'a str),
163 /// error E0420: is not an associated const
164 NotAnAssociatedConst(&'a str),
165 /// error E0421: unresolved associated const
166 UnresolvedAssociatedConst(&'a str),
167 /// error E0422: does not name a struct
168 DoesNotNameAStruct(&'a str),
169 /// error E0423: is a struct variant name, but this expression uses it like a function name
170 StructVariantUsedAsFunction(&'a str),
171 /// error E0424: `self` is not available in a static method
172 SelfNotAvailableInStaticMethod,
173 /// error E0425: unresolved name
174 UnresolvedName(&'a str, &'a str, UnresolvedNameContext),
175 /// error E0426: use of undeclared label
176 UndeclaredLabel(&'a str),
177 /// error E0427: cannot use `ref` binding mode with ...
178 CannotUseRefBindingModeWith(&'a str),
179 /// error E0428: duplicate definition
180 DuplicateDefinition(&'a str, Name),
181 /// error E0429: `self` imports are only allowed within a { } list
182 SelfImportsOnlyAllowedWithin,
183 /// error E0430: `self` import can only appear once in the list
184 SelfImportCanOnlyAppearOnceInTheList,
185 /// error E0431: `self` import can only appear in an import list with a non-empty prefix
186 SelfImportOnlyInImportListWithNonEmptyPrefix,
187 /// error E0432: unresolved import
188 UnresolvedImport(Option<(&'a str, &'a str)>),
189 /// error E0433: failed to resolve
190 FailedToResolve(&'a str),
191 /// error E0434: can't capture dynamic environment in a fn item
192 CannotCaptureDynamicEnvironmentInFnItem,
193 /// error E0435: attempt to use a non-constant value in a constant
194 AttemptToUseNonConstantValueInConstant,
197 /// Context of where `ResolutionError::UnresolvedName` arose.
198 #[derive(Clone, PartialEq, Eq, Debug)]
199 pub enum UnresolvedNameContext {
200 /// `PathIsMod(id)` indicates that a given path, used in
201 /// expression context, actually resolved to a module rather than
202 /// a value. The `id` attached to the variant is the node id of
203 /// the erroneous path expression.
204 PathIsMod(ast::NodeId),
206 /// `Other` means we have no extra information about the context
207 /// of the unresolved name error. (Maybe we could eliminate all
208 /// such cases; but for now, this is an information-free default.)
212 fn resolve_error<'b, 'a: 'b, 'tcx: 'a>(resolver: &'b Resolver<'a, 'tcx>,
213 span: syntax::codemap::Span,
214 resolution_error: ResolutionError<'b>) {
215 resolve_struct_error(resolver, span, resolution_error).emit();
218 fn resolve_struct_error<'b, 'a: 'b, 'tcx: 'a>(resolver: &'b Resolver<'a, 'tcx>,
219 span: syntax::codemap::Span,
220 resolution_error: ResolutionError<'b>)
221 -> DiagnosticBuilder<'a> {
222 if !resolver.emit_errors {
223 return resolver.session.diagnostic().struct_dummy();
226 match resolution_error {
227 ResolutionError::TypeParametersFromOuterFunction => {
228 struct_span_err!(resolver.session,
231 "can't use type parameters from outer function; try using a local \
232 type parameter instead")
234 ResolutionError::OuterTypeParameterContext => {
235 struct_span_err!(resolver.session,
238 "cannot use an outer type parameter in this context")
240 ResolutionError::NameAlreadyUsedInTypeParameterList(name) => {
241 struct_span_err!(resolver.session,
244 "the name `{}` is already used for a type parameter in this type \
248 ResolutionError::IsNotATrait(name) => {
249 struct_span_err!(resolver.session, span, E0404, "`{}` is not a trait", name)
251 ResolutionError::UndeclaredTraitName(name) => {
252 struct_span_err!(resolver.session,
255 "use of undeclared trait name `{}`",
258 ResolutionError::UndeclaredAssociatedType => {
259 struct_span_err!(resolver.session, span, E0406, "undeclared associated type")
261 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
262 struct_span_err!(resolver.session,
265 "method `{}` is not a member of trait `{}`",
269 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
270 struct_span_err!(resolver.session,
273 "type `{}` is not a member of trait `{}`",
277 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
278 struct_span_err!(resolver.session,
281 "const `{}` is not a member of trait `{}`",
285 ResolutionError::VariableNotBoundInPattern(variable_name, pattern_number) => {
286 struct_span_err!(resolver.session,
289 "variable `{}` from pattern #1 is not bound in pattern #{}",
293 ResolutionError::VariableBoundWithDifferentMode(variable_name, pattern_number) => {
294 struct_span_err!(resolver.session,
297 "variable `{}` is bound with different mode in pattern #{} than in \
302 ResolutionError::VariableNotBoundInParentPattern(variable_name, pattern_number) => {
303 struct_span_err!(resolver.session,
306 "variable `{}` from pattern #{} is not bound in pattern #1",
310 ResolutionError::SelfUsedOutsideImplOrTrait => {
311 struct_span_err!(resolver.session,
314 "use of `Self` outside of an impl or trait")
316 ResolutionError::UseOfUndeclared(kind, name) => {
317 struct_span_err!(resolver.session,
320 "use of undeclared {} `{}`",
324 ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(name) => {
325 struct_span_err!(resolver.session,
328 "declaration of `{}` shadows an enum variant \
329 or unit-like struct in scope",
332 ResolutionError::OnlyIrrefutablePatternsAllowedHere(did, name) => {
333 let mut err = struct_span_err!(resolver.session,
336 "only irrefutable patterns allowed here");
338 "there already is a constant in scope sharing the same \
339 name as this pattern");
340 if let Some(sp) = resolver.ast_map.span_if_local(did) {
341 err.span_note(sp, "constant defined here");
343 if let Success(binding) = resolver.current_module.resolve_name(name, ValueNS, true) {
344 if binding.is_import() {
345 err.span_note(binding.span.unwrap(), "constant imported here");
350 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
351 struct_span_err!(resolver.session,
354 "identifier `{}` is bound more than once in this parameter list",
357 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
358 struct_span_err!(resolver.session,
361 "identifier `{}` is bound more than once in the same pattern",
364 ResolutionError::StaticVariableReference => {
365 struct_span_err!(resolver.session,
368 "static variables cannot be referenced in a pattern, use a \
371 ResolutionError::NotAnEnumVariantStructOrConst(name) => {
372 struct_span_err!(resolver.session,
375 "`{}` is not an enum variant, struct or const",
378 ResolutionError::UnresolvedEnumVariantStructOrConst(name) => {
379 struct_span_err!(resolver.session,
382 "unresolved enum variant, struct or const `{}`",
385 ResolutionError::NotAnAssociatedConst(name) => {
386 struct_span_err!(resolver.session,
389 "`{}` is not an associated const",
392 ResolutionError::UnresolvedAssociatedConst(name) => {
393 struct_span_err!(resolver.session,
396 "unresolved associated const `{}`",
399 ResolutionError::DoesNotNameAStruct(name) => {
400 struct_span_err!(resolver.session,
403 "`{}` does not name a structure",
406 ResolutionError::StructVariantUsedAsFunction(path_name) => {
407 struct_span_err!(resolver.session,
410 "`{}` is the name of a struct or struct variant, but this expression \
411 uses it like a function name",
414 ResolutionError::SelfNotAvailableInStaticMethod => {
415 struct_span_err!(resolver.session,
418 "`self` is not available in a static method. Maybe a `self` \
419 argument is missing?")
421 ResolutionError::UnresolvedName(path, msg, context) => {
422 let mut err = struct_span_err!(resolver.session,
425 "unresolved name `{}`{}",
430 UnresolvedNameContext::Other => { } // no help available
431 UnresolvedNameContext::PathIsMod(id) => {
432 let mut help_msg = String::new();
433 let parent_id = resolver.ast_map.get_parent_node(id);
434 if let Some(hir_map::Node::NodeExpr(e)) = resolver.ast_map.find(parent_id) {
436 ExprField(_, ident) => {
437 help_msg = format!("To reference an item from the \
438 `{module}` module, use \
439 `{module}::{ident}`",
443 ExprMethodCall(ident, _, _) => {
444 help_msg = format!("To call a function from the \
445 `{module}` module, use \
446 `{module}::{ident}(..)`",
451 help_msg = format!("No function corresponds to `{module}(..)`",
454 _ => { } // no help available
457 help_msg = format!("Module `{module}` cannot be the value of an expression",
461 if !help_msg.is_empty() {
462 err.fileline_help(span, &help_msg);
468 ResolutionError::UndeclaredLabel(name) => {
469 struct_span_err!(resolver.session,
472 "use of undeclared label `{}`",
475 ResolutionError::CannotUseRefBindingModeWith(descr) => {
476 struct_span_err!(resolver.session,
479 "cannot use `ref` binding mode with {}",
482 ResolutionError::DuplicateDefinition(namespace, name) => {
483 struct_span_err!(resolver.session,
486 "duplicate definition of {} `{}`",
490 ResolutionError::SelfImportsOnlyAllowedWithin => {
491 struct_span_err!(resolver.session,
495 "`self` imports are only allowed within a { } list")
497 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
498 struct_span_err!(resolver.session,
501 "`self` import can only appear once in the list")
503 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
504 struct_span_err!(resolver.session,
507 "`self` import can only appear in an import list with a \
510 ResolutionError::UnresolvedImport(name) => {
511 let msg = match name {
512 Some((n, p)) => format!("unresolved import `{}`{}", n, p),
513 None => "unresolved import".to_owned(),
515 struct_span_err!(resolver.session, span, E0432, "{}", msg)
517 ResolutionError::FailedToResolve(msg) => {
518 struct_span_err!(resolver.session, span, E0433, "failed to resolve. {}", msg)
520 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
521 struct_span_err!(resolver.session,
525 "can't capture dynamic environment in a fn item; use the || { ... } \
526 closure form instead")
528 ResolutionError::AttemptToUseNonConstantValueInConstant => {
529 struct_span_err!(resolver.session,
532 "attempt to use a non-constant value in a constant")
537 #[derive(Copy, Clone)]
540 binding_mode: BindingMode,
543 // Map from the name in a pattern to its binding mode.
544 type BindingMap = HashMap<Name, BindingInfo>;
546 #[derive(Copy, Clone, PartialEq)]
547 enum PatternBindingMode {
549 LocalIrrefutableMode,
550 ArgumentIrrefutableMode,
553 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
559 impl<'a, 'v, 'tcx> Visitor<'v> for Resolver<'a, 'tcx> {
560 fn visit_nested_item(&mut self, item: hir::ItemId) {
561 self.visit_item(self.ast_map.expect_item(item.id))
563 fn visit_item(&mut self, item: &Item) {
564 execute_callback!(hir_map::Node::NodeItem(item), self);
565 self.resolve_item(item);
567 fn visit_arm(&mut self, arm: &Arm) {
568 self.resolve_arm(arm);
570 fn visit_block(&mut self, block: &Block) {
571 execute_callback!(hir_map::Node::NodeBlock(block), self);
572 self.resolve_block(block);
574 fn visit_expr(&mut self, expr: &Expr) {
575 execute_callback!(hir_map::Node::NodeExpr(expr), self);
576 self.resolve_expr(expr);
578 fn visit_local(&mut self, local: &Local) {
579 execute_callback!(hir_map::Node::NodeLocal(&local.pat), self);
580 self.resolve_local(local);
582 fn visit_ty(&mut self, ty: &Ty) {
583 self.resolve_type(ty);
585 fn visit_generics(&mut self, generics: &Generics) {
586 self.resolve_generics(generics);
588 fn visit_poly_trait_ref(&mut self, tref: &hir::PolyTraitRef, m: &hir::TraitBoundModifier) {
589 match self.resolve_trait_reference(tref.trait_ref.ref_id, &tref.trait_ref.path, 0) {
590 Ok(def) => self.record_def(tref.trait_ref.ref_id, def),
592 // error already reported
593 self.record_def(tref.trait_ref.ref_id, err_path_resolution())
596 intravisit::walk_poly_trait_ref(self, tref, m);
598 fn visit_variant(&mut self,
599 variant: &hir::Variant,
601 item_id: ast::NodeId) {
602 execute_callback!(hir_map::Node::NodeVariant(variant), self);
603 if let Some(ref dis_expr) = variant.node.disr_expr {
604 // resolve the discriminator expr as a constant
605 self.with_constant_rib(|this| {
606 this.visit_expr(dis_expr);
610 // `intravisit::walk_variant` without the discriminant expression.
611 self.visit_variant_data(&variant.node.data,
617 fn visit_foreign_item(&mut self, foreign_item: &hir::ForeignItem) {
618 execute_callback!(hir_map::Node::NodeForeignItem(foreign_item), self);
619 let type_parameters = match foreign_item.node {
620 ForeignItemFn(_, ref generics) => {
621 HasTypeParameters(generics, FnSpace, ItemRibKind)
623 ForeignItemStatic(..) => NoTypeParameters,
625 self.with_type_parameter_rib(type_parameters, |this| {
626 intravisit::walk_foreign_item(this, foreign_item);
629 fn visit_fn(&mut self,
630 function_kind: FnKind<'v>,
631 declaration: &'v FnDecl,
635 let rib_kind = match function_kind {
636 FnKind::ItemFn(_, generics, _, _, _, _) => {
637 self.visit_generics(generics);
640 FnKind::Method(_, sig, _) => {
641 self.visit_generics(&sig.generics);
642 self.visit_explicit_self(&sig.explicit_self);
645 FnKind::Closure => ClosureRibKind(node_id),
647 self.resolve_function(rib_kind, declaration, block);
651 pub type ErrorMessage = Option<(Span, String)>;
653 #[derive(Clone, PartialEq, Eq)]
654 pub enum ResolveResult<T> {
655 Failed(ErrorMessage), // Failed to resolve the name, optional helpful error message.
656 Indeterminate, // Couldn't determine due to unresolved globs.
657 Success(T), // Successfully resolved the import.
660 impl<T> ResolveResult<T> {
661 fn and_then<U, F: FnOnce(T) -> ResolveResult<U>>(self, f: F) -> ResolveResult<U> {
663 Failed(msg) => Failed(msg),
664 Indeterminate => Indeterminate,
669 fn success(self) -> Option<T> {
671 Success(t) => Some(t),
677 enum FallbackSuggestion {
682 StaticMethod(String),
686 #[derive(Copy, Clone)]
687 enum TypeParameters<'tcx, 'a> {
689 HasTypeParameters(// Type parameters.
692 // Identifies the things that these parameters
693 // were declared on (type, fn, etc)
696 // The kind of the rib used for type parameters.
700 // The rib kind controls the translation of local
701 // definitions (`Def::Local`) to upvars (`Def::Upvar`).
702 #[derive(Copy, Clone, Debug)]
704 // No translation needs to be applied.
707 // We passed through a closure scope at the given node ID.
708 // Translate upvars as appropriate.
709 ClosureRibKind(NodeId /* func id */),
711 // We passed through an impl or trait and are now in one of its
712 // methods. Allow references to ty params that impl or trait
713 // binds. Disallow any other upvars (including other ty params that are
717 // We passed through an item scope. Disallow upvars.
720 // We're in a constant item. Can't refer to dynamic stuff.
723 // We passed through an anonymous module.
724 AnonymousModuleRibKind(Module<'a>),
727 #[derive(Copy, Clone)]
728 enum UseLexicalScopeFlag {
733 enum ModulePrefixResult<'a> {
735 PrefixFound(Module<'a>, usize),
738 #[derive(Copy, Clone)]
739 enum AssocItemResolveResult {
740 /// Syntax such as `<T>::item`, which can't be resolved until type
743 /// We should have been able to resolve the associated item.
744 ResolveAttempt(Option<PathResolution>),
747 #[derive(Copy, Clone)]
748 enum BareIdentifierPatternResolution {
749 FoundStructOrEnumVariant(Def, LastPrivate),
750 FoundConst(Def, LastPrivate, Name),
751 BareIdentifierPatternUnresolved,
757 bindings: HashMap<Name, DefLike>,
762 fn new(kind: RibKind<'a>) -> Rib<'a> {
764 bindings: HashMap::new(),
770 /// A definition along with the index of the rib it was found on
772 ribs: Option<(Namespace, usize)>,
777 fn from_def(def: Def) -> Self {
785 /// The link from a module up to its nearest parent node.
786 #[derive(Clone,Debug)]
787 enum ParentLink<'a> {
789 ModuleParentLink(Module<'a>, Name),
790 BlockParentLink(Module<'a>, NodeId),
793 /// One node in the tree of modules.
794 pub struct ModuleS<'a> {
795 parent_link: ParentLink<'a>,
798 is_extern_crate: bool,
800 resolutions: RefCell<HashMap<(Name, Namespace), NameResolution<'a>>>,
801 imports: RefCell<Vec<ImportDirective>>,
803 // The module children of this node, including normal modules and anonymous modules.
804 // Anonymous children are pseudo-modules that are implicitly created around items
805 // contained within blocks.
807 // For example, if we have this:
815 // There will be an anonymous module created around `g` with the ID of the
816 // entry block for `f`.
817 module_children: RefCell<NodeMap<Module<'a>>>,
819 shadowed_traits: RefCell<Vec<&'a NameBinding<'a>>>,
821 // The number of unresolved globs that this module exports.
822 glob_count: Cell<usize>,
824 // The number of unresolved pub imports (both regular and globs) in this module
825 pub_count: Cell<usize>,
827 // The number of unresolved pub glob imports in this module
828 pub_glob_count: Cell<usize>,
830 // The index of the import we're resolving.
831 resolved_import_count: Cell<usize>,
833 // Whether this module is populated. If not populated, any attempt to
834 // access the children must be preceded with a
835 // `populate_module_if_necessary` call.
836 populated: Cell<bool>,
839 pub type Module<'a> = &'a ModuleS<'a>;
841 impl<'a> ModuleS<'a> {
842 fn new(parent_link: ParentLink<'a>, def: Option<Def>, external: bool, is_public: bool) -> Self {
844 parent_link: parent_link,
846 is_public: is_public,
847 is_extern_crate: false,
848 resolutions: RefCell::new(HashMap::new()),
849 imports: RefCell::new(Vec::new()),
850 module_children: RefCell::new(NodeMap()),
851 shadowed_traits: RefCell::new(Vec::new()),
852 glob_count: Cell::new(0),
853 pub_count: Cell::new(0),
854 pub_glob_count: Cell::new(0),
855 resolved_import_count: Cell::new(0),
856 populated: Cell::new(!external),
860 fn resolve_name(&self, name: Name, ns: Namespace, allow_private_imports: bool)
861 -> ResolveResult<&'a NameBinding<'a>> {
863 if allow_private_imports { self.glob_count.get() } else { self.pub_glob_count.get() };
865 self.resolutions.borrow().get(&(name, ns)).cloned().unwrap_or_default().result(glob_count)
866 .and_then(|binding| {
867 let allowed = allow_private_imports || !binding.is_import() || binding.is_public();
868 if allowed { Success(binding) } else { Failed(None) }
872 // Define the name or return the existing binding if there is a collision.
873 fn try_define_child(&self, name: Name, ns: Namespace, binding: &'a NameBinding<'a>)
874 -> Result<(), &'a NameBinding<'a>> {
875 let mut children = self.resolutions.borrow_mut();
876 let resolution = children.entry((name, ns)).or_insert_with(Default::default);
878 // FIXME #31379: We can use methods from imported traits shadowed by non-import items
879 if let Some(old_binding) = resolution.binding {
880 if !old_binding.is_import() && binding.is_import() {
881 if let Some(Def::Trait(_)) = binding.def() {
882 self.shadowed_traits.borrow_mut().push(binding);
887 resolution.try_define(binding)
890 fn increment_outstanding_references_for(&self, name: Name, ns: Namespace) {
891 let mut children = self.resolutions.borrow_mut();
892 children.entry((name, ns)).or_insert_with(Default::default).outstanding_references += 1;
895 fn decrement_outstanding_references_for(&self, name: Name, ns: Namespace) {
896 match self.resolutions.borrow_mut().get_mut(&(name, ns)).unwrap().outstanding_references {
897 0 => panic!("No more outstanding references!"),
898 ref mut outstanding_references => { *outstanding_references -= 1; }
902 fn for_each_child<F: FnMut(Name, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
903 for (&(name, ns), name_resolution) in self.resolutions.borrow().iter() {
904 name_resolution.binding.map(|binding| f(name, ns, binding));
908 fn def_id(&self) -> Option<DefId> {
909 self.def.as_ref().map(Def::def_id)
912 fn is_normal(&self) -> bool {
914 Some(Def::Mod(_)) | Some(Def::ForeignMod(_)) => true,
919 fn is_trait(&self) -> bool {
921 Some(Def::Trait(_)) => true,
926 fn all_imports_resolved(&self) -> bool {
927 if self.imports.borrow_state() == ::std::cell::BorrowState::Writing {
928 // it is currently being resolved ! so nope
931 self.imports.borrow().len() == self.resolved_import_count.get()
935 pub fn inc_glob_count(&self) {
936 self.glob_count.set(self.glob_count.get() + 1);
938 pub fn dec_glob_count(&self) {
939 assert!(self.glob_count.get() > 0);
940 self.glob_count.set(self.glob_count.get() - 1);
942 pub fn inc_pub_count(&self) {
943 self.pub_count.set(self.pub_count.get() + 1);
945 pub fn dec_pub_count(&self) {
946 assert!(self.pub_count.get() > 0);
947 self.pub_count.set(self.pub_count.get() - 1);
949 pub fn inc_pub_glob_count(&self) {
950 self.pub_glob_count.set(self.pub_glob_count.get() + 1);
952 pub fn dec_pub_glob_count(&self) {
953 assert!(self.pub_glob_count.get() > 0);
954 self.pub_glob_count.set(self.pub_glob_count.get() - 1);
958 impl<'a> fmt::Debug for ModuleS<'a> {
959 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
973 flags DefModifiers: u8 {
974 // Enum variants are always considered `PUBLIC`, this is needed for `use Enum::Variant`
975 // or `use Enum::*` to work on private enums.
976 const PUBLIC = 1 << 0,
977 const IMPORTABLE = 1 << 1,
978 // Variants are considered `PUBLIC`, but some of them live in private enums.
979 // We need to track them to prohibit reexports like `pub use PrivEnum::Variant`.
980 const PRIVATE_VARIANT = 1 << 2,
981 const PRELUDE = 1 << 3,
982 const GLOB_IMPORTED = 1 << 4,
986 // Records a possibly-private value, type, or module definition.
988 pub struct NameBinding<'a> {
989 modifiers: DefModifiers,
990 kind: NameBindingKind<'a>,
995 enum NameBindingKind<'a> {
999 binding: &'a NameBinding<'a>,
1004 impl<'a> NameBinding<'a> {
1005 fn create_from_module(module: Module<'a>, span: Option<Span>) -> Self {
1006 let modifiers = if module.is_public {
1007 DefModifiers::PUBLIC
1009 DefModifiers::empty()
1010 } | DefModifiers::IMPORTABLE;
1012 NameBinding { modifiers: modifiers, kind: NameBindingKind::Module(module), span: span }
1015 fn module(&self) -> Option<Module<'a>> {
1017 NameBindingKind::Module(module) => Some(module),
1018 NameBindingKind::Def(_) => None,
1019 NameBindingKind::Import { binding, .. } => binding.module(),
1023 fn def(&self) -> Option<Def> {
1025 NameBindingKind::Def(def) => Some(def),
1026 NameBindingKind::Module(module) => module.def,
1027 NameBindingKind::Import { binding, .. } => binding.def(),
1031 fn defined_with(&self, modifiers: DefModifiers) -> bool {
1032 self.modifiers.contains(modifiers)
1035 fn is_public(&self) -> bool {
1036 self.defined_with(DefModifiers::PUBLIC)
1039 fn def_and_lp(&self) -> (Def, LastPrivate) {
1040 let def = self.def().unwrap();
1041 (def, LastMod(if self.is_public() { AllPublic } else { DependsOn(def.def_id()) }))
1044 fn is_extern_crate(&self) -> bool {
1045 self.module().map(|module| module.is_extern_crate).unwrap_or(false)
1048 fn is_import(&self) -> bool {
1050 NameBindingKind::Import { .. } => true,
1056 /// Interns the names of the primitive types.
1057 struct PrimitiveTypeTable {
1058 primitive_types: HashMap<Name, PrimTy>,
1061 impl PrimitiveTypeTable {
1062 fn new() -> PrimitiveTypeTable {
1063 let mut table = PrimitiveTypeTable { primitive_types: HashMap::new() };
1065 table.intern("bool", TyBool);
1066 table.intern("char", TyChar);
1067 table.intern("f32", TyFloat(FloatTy::F32));
1068 table.intern("f64", TyFloat(FloatTy::F64));
1069 table.intern("isize", TyInt(IntTy::Is));
1070 table.intern("i8", TyInt(IntTy::I8));
1071 table.intern("i16", TyInt(IntTy::I16));
1072 table.intern("i32", TyInt(IntTy::I32));
1073 table.intern("i64", TyInt(IntTy::I64));
1074 table.intern("str", TyStr);
1075 table.intern("usize", TyUint(UintTy::Us));
1076 table.intern("u8", TyUint(UintTy::U8));
1077 table.intern("u16", TyUint(UintTy::U16));
1078 table.intern("u32", TyUint(UintTy::U32));
1079 table.intern("u64", TyUint(UintTy::U64));
1084 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1085 self.primitive_types.insert(token::intern(string), primitive_type);
1089 /// The main resolver class.
1090 pub struct Resolver<'a, 'tcx: 'a> {
1091 session: &'a Session,
1093 ast_map: &'a hir_map::Map<'tcx>,
1095 graph_root: Module<'a>,
1097 trait_item_map: FnvHashMap<(Name, DefId), DefId>,
1099 structs: FnvHashMap<DefId, Vec<Name>>,
1101 // The number of imports that are currently unresolved.
1102 unresolved_imports: usize,
1104 // The module that represents the current item scope.
1105 current_module: Module<'a>,
1107 // The current set of local scopes, for values.
1108 // FIXME #4948: Reuse ribs to avoid allocation.
1109 value_ribs: Vec<Rib<'a>>,
1111 // The current set of local scopes, for types.
1112 type_ribs: Vec<Rib<'a>>,
1114 // The current set of local scopes, for labels.
1115 label_ribs: Vec<Rib<'a>>,
1117 // The trait that the current context can refer to.
1118 current_trait_ref: Option<(DefId, TraitRef)>,
1120 // The current self type if inside an impl (used for better errors).
1121 current_self_type: Option<Ty>,
1123 // The idents for the primitive types.
1124 primitive_type_table: PrimitiveTypeTable,
1126 def_map: RefCell<DefMap>,
1127 freevars: FreevarMap,
1128 freevars_seen: NodeMap<NodeMap<usize>>,
1129 export_map: ExportMap,
1130 trait_map: TraitMap,
1131 external_exports: ExternalExports,
1133 // Whether or not to print error messages. Can be set to true
1134 // when getting additional info for error message suggestions,
1135 // so as to avoid printing duplicate errors
1138 make_glob_map: bool,
1139 // Maps imports to the names of items actually imported (this actually maps
1140 // all imports, but only glob imports are actually interesting).
1143 used_imports: HashSet<(NodeId, Namespace)>,
1144 used_crates: HashSet<CrateNum>,
1146 // Callback function for intercepting walks
1147 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>,
1148 // The intention is that the callback modifies this flag.
1149 // Once set, the resolver falls out of the walk, preserving the ribs.
1152 arenas: &'a ResolverArenas<'a>,
1155 pub struct ResolverArenas<'a> {
1156 modules: arena::TypedArena<ModuleS<'a>>,
1157 name_bindings: arena::TypedArena<NameBinding<'a>>,
1160 #[derive(PartialEq)]
1161 enum FallbackChecks {
1163 OnlyTraitAndStatics,
1166 impl<'a, 'tcx> Resolver<'a, 'tcx> {
1167 fn new(session: &'a Session,
1168 ast_map: &'a hir_map::Map<'tcx>,
1169 make_glob_map: MakeGlobMap,
1170 arenas: &'a ResolverArenas<'a>)
1171 -> Resolver<'a, 'tcx> {
1172 let root_def_id = ast_map.local_def_id(CRATE_NODE_ID);
1173 let graph_root = ModuleS::new(NoParentLink, Some(Def::Mod(root_def_id)), false, true);
1174 let graph_root = arenas.modules.alloc(graph_root);
1181 // The outermost module has def ID 0; this is not reflected in the
1183 graph_root: graph_root,
1185 trait_item_map: FnvHashMap(),
1186 structs: FnvHashMap(),
1188 unresolved_imports: 0,
1190 current_module: graph_root,
1191 value_ribs: Vec::new(),
1192 type_ribs: Vec::new(),
1193 label_ribs: Vec::new(),
1195 current_trait_ref: None,
1196 current_self_type: None,
1198 primitive_type_table: PrimitiveTypeTable::new(),
1200 def_map: RefCell::new(NodeMap()),
1201 freevars: NodeMap(),
1202 freevars_seen: NodeMap(),
1203 export_map: NodeMap(),
1204 trait_map: NodeMap(),
1205 used_imports: HashSet::new(),
1206 used_crates: HashSet::new(),
1207 external_exports: DefIdSet(),
1210 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1211 glob_map: HashMap::new(),
1220 fn arenas() -> ResolverArenas<'a> {
1222 modules: arena::TypedArena::new(),
1223 name_bindings: arena::TypedArena::new(),
1227 fn new_module(&self,
1228 parent_link: ParentLink<'a>,
1231 is_public: bool) -> Module<'a> {
1232 self.arenas.modules.alloc(ModuleS::new(parent_link, def, external, is_public))
1235 fn new_name_binding(&self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1236 self.arenas.name_bindings.alloc(name_binding)
1239 fn new_extern_crate_module(&self, parent_link: ParentLink<'a>, def: Def) -> Module<'a> {
1240 let mut module = ModuleS::new(parent_link, Some(def), false, true);
1241 module.is_extern_crate = true;
1242 self.arenas.modules.alloc(module)
1245 fn get_ribs<'b>(&'b mut self, ns: Namespace) -> &'b mut Vec<Rib<'a>> {
1246 match ns { ValueNS => &mut self.value_ribs, TypeNS => &mut self.type_ribs }
1250 fn record_use(&mut self, name: Name, ns: Namespace, binding: &'a NameBinding<'a>) {
1251 // track extern crates for unused_extern_crate lint
1252 if let Some(DefId { krate, .. }) = binding.module().and_then(ModuleS::def_id) {
1253 self.used_crates.insert(krate);
1256 let import_id = match binding.kind {
1257 NameBindingKind::Import { id, .. } => id,
1261 self.used_imports.insert((import_id, ns));
1263 if !self.make_glob_map {
1266 if self.glob_map.contains_key(&import_id) {
1267 self.glob_map.get_mut(&import_id).unwrap().insert(name);
1271 let mut new_set = HashSet::new();
1272 new_set.insert(name);
1273 self.glob_map.insert(import_id, new_set);
1276 fn get_trait_name(&self, did: DefId) -> Name {
1277 if let Some(node_id) = self.ast_map.as_local_node_id(did) {
1278 self.ast_map.expect_item(node_id).name
1280 self.session.cstore.item_name(did)
1284 /// Resolves the given module path from the given root `module_`.
1285 fn resolve_module_path_from_root(&mut self,
1286 module_: Module<'a>,
1287 module_path: &[Name],
1291 -> ResolveResult<(Module<'a>, LastPrivate)> {
1292 fn search_parent_externals<'a>(needle: Name, module: Module<'a>) -> Option<Module<'a>> {
1293 match module.resolve_name(needle, TypeNS, false) {
1294 Success(binding) if binding.is_extern_crate() => Some(module),
1295 _ => match module.parent_link {
1296 ModuleParentLink(ref parent, _) => {
1297 search_parent_externals(needle, parent)
1304 let mut search_module = module_;
1305 let mut index = index;
1306 let module_path_len = module_path.len();
1307 let mut closest_private = lp;
1309 // Resolve the module part of the path. This does not involve looking
1310 // upward though scope chains; we simply resolve names directly in
1311 // modules as we go.
1312 while index < module_path_len {
1313 let name = module_path[index];
1314 match self.resolve_name_in_module(search_module, name, TypeNS, false, true) {
1316 let segment_name = name.as_str();
1317 let module_name = module_to_string(search_module);
1318 let mut span = span;
1319 let msg = if "???" == &module_name {
1320 span.hi = span.lo + Pos::from_usize(segment_name.len());
1322 match search_parent_externals(name, &self.current_module) {
1324 let path_str = names_to_string(module_path);
1325 let target_mod_str = module_to_string(&module);
1326 let current_mod_str = module_to_string(&self.current_module);
1328 let prefix = if target_mod_str == current_mod_str {
1329 "self::".to_string()
1331 format!("{}::", target_mod_str)
1334 format!("Did you mean `{}{}`?", prefix, path_str)
1336 None => format!("Maybe a missing `extern crate {}`?", segment_name),
1339 format!("Could not find `{}` in `{}`", segment_name, module_name)
1342 return Failed(Some((span, msg)));
1344 Failed(err) => return Failed(err),
1346 debug!("(resolving module path for import) module resolution is \
1349 return Indeterminate;
1351 Success(binding) => {
1352 // Check to see whether there are type bindings, and, if
1353 // so, whether there is a module within.
1354 if let Some(module_def) = binding.module() {
1355 search_module = module_def;
1357 // Keep track of the closest private module used
1358 // when resolving this import chain.
1359 if !binding.is_public() {
1360 if let Some(did) = search_module.def_id() {
1361 closest_private = LastMod(DependsOn(did));
1365 let msg = format!("Not a module `{}`", name);
1366 return Failed(Some((span, msg)));
1374 return Success((search_module, closest_private));
1377 /// Attempts to resolve the module part of an import directive or path
1378 /// rooted at the given module.
1380 /// On success, returns the resolved module, and the closest *private*
1381 /// module found to the destination when resolving this path.
1382 fn resolve_module_path(&mut self,
1383 module_: Module<'a>,
1384 module_path: &[Name],
1385 use_lexical_scope: UseLexicalScopeFlag,
1387 -> ResolveResult<(Module<'a>, LastPrivate)> {
1388 if module_path.len() == 0 {
1389 return Success((self.graph_root, LastMod(AllPublic))) // Use the crate root
1392 debug!("(resolving module path for import) processing `{}` rooted at `{}`",
1393 names_to_string(module_path),
1394 module_to_string(&module_));
1396 // Resolve the module prefix, if any.
1397 let module_prefix_result = self.resolve_module_prefix(module_, module_path);
1402 match module_prefix_result {
1404 let mpath = names_to_string(module_path);
1405 let mpath = &mpath[..];
1406 match mpath.rfind(':') {
1408 let msg = format!("Could not find `{}` in `{}`",
1409 // idx +- 1 to account for the
1410 // colons on either side
1413 return Failed(Some((span, msg)));
1416 return Failed(None);
1420 Failed(err) => return Failed(err),
1422 debug!("(resolving module path for import) indeterminate; bailing");
1423 return Indeterminate;
1425 Success(NoPrefixFound) => {
1426 // There was no prefix, so we're considering the first element
1427 // of the path. How we handle this depends on whether we were
1428 // instructed to use lexical scope or not.
1429 match use_lexical_scope {
1430 DontUseLexicalScope => {
1431 // This is a crate-relative path. We will start the
1432 // resolution process at index zero.
1433 search_module = self.graph_root;
1435 last_private = LastMod(AllPublic);
1437 UseLexicalScope => {
1438 // This is not a crate-relative path. We resolve the
1439 // first component of the path in the current lexical
1440 // scope and then proceed to resolve below that.
1441 match self.resolve_item_in_lexical_scope(module_,
1445 Failed(err) => return Failed(err),
1447 debug!("(resolving module path for import) indeterminate; bailing");
1448 return Indeterminate;
1450 Success(binding) => match binding.module() {
1451 Some(containing_module) => {
1452 search_module = containing_module;
1454 last_private = LastMod(AllPublic);
1456 None => return Failed(None),
1462 Success(PrefixFound(ref containing_module, index)) => {
1463 search_module = containing_module;
1464 start_index = index;
1465 last_private = LastMod(DependsOn(containing_module.def_id()
1470 self.resolve_module_path_from_root(search_module,
1477 /// Invariant: This must only be called during main resolution, not during
1478 /// import resolution.
1479 fn resolve_item_in_lexical_scope(&mut self,
1480 module_: Module<'a>,
1482 namespace: Namespace,
1484 -> ResolveResult<&'a NameBinding<'a>> {
1485 debug!("(resolving item in lexical scope) resolving `{}` in namespace {:?} in `{}`",
1488 module_to_string(&module_));
1490 // Proceed up the scope chain looking for parent modules.
1491 let mut search_module = module_;
1493 // Resolve the name in the parent module.
1494 match self.resolve_name_in_module(search_module, name, namespace, true, record_used) {
1495 Failed(Some((span, msg))) => {
1496 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
1498 Failed(None) => (), // Continue up the search chain.
1500 // We couldn't see through the higher scope because of an
1501 // unresolved import higher up. Bail.
1503 debug!("(resolving item in lexical scope) indeterminate higher scope; bailing");
1504 return Indeterminate;
1506 Success(binding) => {
1507 // We found the module.
1508 debug!("(resolving item in lexical scope) found name in module, done");
1509 return Success(binding);
1513 // Go to the next parent.
1514 match search_module.parent_link {
1516 // No more parents. This module was unresolved.
1517 debug!("(resolving item in lexical scope) unresolved module: no parent module");
1518 return Failed(None);
1520 ModuleParentLink(parent_module_node, _) => {
1521 if search_module.is_normal() {
1522 // We stop the search here.
1523 debug!("(resolving item in lexical scope) unresolved module: not \
1524 searching through module parents");
1525 return Failed(None);
1527 search_module = parent_module_node;
1530 BlockParentLink(parent_module_node, _) => {
1531 search_module = parent_module_node;
1537 /// Returns the nearest normal module parent of the given module.
1538 fn get_nearest_normal_module_parent(&mut self, module_: Module<'a>) -> Option<Module<'a>> {
1539 let mut module_ = module_;
1541 match module_.parent_link {
1542 NoParentLink => return None,
1543 ModuleParentLink(new_module, _) |
1544 BlockParentLink(new_module, _) => {
1545 let new_module = new_module;
1546 if new_module.is_normal() {
1547 return Some(new_module);
1549 module_ = new_module;
1555 /// Returns the nearest normal module parent of the given module, or the
1556 /// module itself if it is a normal module.
1557 fn get_nearest_normal_module_parent_or_self(&mut self, module_: Module<'a>) -> Module<'a> {
1558 if module_.is_normal() {
1561 match self.get_nearest_normal_module_parent(module_) {
1563 Some(new_module) => new_module,
1567 /// Resolves a "module prefix". A module prefix is one or both of (a) `self::`;
1568 /// (b) some chain of `super::`.
1569 /// grammar: (SELF MOD_SEP ) ? (SUPER MOD_SEP) *
1570 fn resolve_module_prefix(&mut self,
1571 module_: Module<'a>,
1572 module_path: &[Name])
1573 -> ResolveResult<ModulePrefixResult<'a>> {
1574 // Start at the current module if we see `self` or `super`, or at the
1575 // top of the crate otherwise.
1576 let mut i = match &*module_path[0].as_str() {
1579 _ => return Success(NoPrefixFound),
1581 let mut containing_module = self.get_nearest_normal_module_parent_or_self(module_);
1583 // Now loop through all the `super`s we find.
1584 while i < module_path.len() && "super" == module_path[i].as_str() {
1585 debug!("(resolving module prefix) resolving `super` at {}",
1586 module_to_string(&containing_module));
1587 match self.get_nearest_normal_module_parent(containing_module) {
1588 None => return Failed(None),
1589 Some(new_module) => {
1590 containing_module = new_module;
1596 debug!("(resolving module prefix) finished resolving prefix at {}",
1597 module_to_string(&containing_module));
1599 return Success(PrefixFound(containing_module, i));
1602 /// Attempts to resolve the supplied name in the given module for the
1603 /// given namespace. If successful, returns the binding corresponding to
1605 fn resolve_name_in_module(&mut self,
1608 namespace: Namespace,
1609 allow_private_imports: bool,
1611 -> ResolveResult<&'a NameBinding<'a>> {
1612 debug!("(resolving name in module) resolving `{}` in `{}`", name, module_to_string(module));
1614 build_reduced_graph::populate_module_if_necessary(self, module);
1615 module.resolve_name(name, namespace, allow_private_imports).and_then(|binding| {
1617 self.record_use(name, namespace, binding);
1623 fn report_unresolved_imports(&mut self, module_: Module<'a>) {
1624 let index = module_.resolved_import_count.get();
1625 let imports = module_.imports.borrow();
1626 let import_count = imports.len();
1627 if index != import_count {
1629 (*imports)[index].span,
1630 ResolutionError::UnresolvedImport(None));
1633 // Descend into children and anonymous children.
1634 for (_, module_) in module_.module_children.borrow().iter() {
1635 self.report_unresolved_imports(module_);
1641 // We maintain a list of value ribs and type ribs.
1643 // Simultaneously, we keep track of the current position in the module
1644 // graph in the `current_module` pointer. When we go to resolve a name in
1645 // the value or type namespaces, we first look through all the ribs and
1646 // then query the module graph. When we resolve a name in the module
1647 // namespace, we can skip all the ribs (since nested modules are not
1648 // allowed within blocks in Rust) and jump straight to the current module
1651 // Named implementations are handled separately. When we find a method
1652 // call, we consult the module node to find all of the implementations in
1653 // scope. This information is lazily cached in the module node. We then
1654 // generate a fake "implementation scope" containing all the
1655 // implementations thus found, for compatibility with old resolve pass.
1657 fn with_scope<F>(&mut self, id: NodeId, f: F)
1658 where F: FnOnce(&mut Resolver)
1660 let orig_module = self.current_module;
1662 // Move down in the graph.
1663 if let Some(module) = orig_module.module_children.borrow().get(&id) {
1664 self.current_module = module;
1669 self.current_module = orig_module;
1672 /// Searches the current set of local scopes for labels.
1673 /// Stops after meeting a closure.
1674 fn search_label(&self, name: Name) -> Option<DefLike> {
1675 for rib in self.label_ribs.iter().rev() {
1681 // Do not resolve labels across function boundary
1685 let result = rib.bindings.get(&name).cloned();
1686 if result.is_some() {
1693 fn resolve_crate(&mut self, krate: &hir::Crate) {
1694 debug!("(resolving crate) starting");
1696 intravisit::walk_crate(self, krate);
1699 fn check_if_primitive_type_name(&self, name: Name, span: Span) {
1700 if let Some(_) = self.primitive_type_table.primitive_types.get(&name) {
1701 span_err!(self.session,
1704 "user-defined types or type parameters cannot shadow the primitive types");
1708 fn resolve_item(&mut self, item: &Item) {
1709 let name = item.name;
1711 debug!("(resolving item) resolving {}", name);
1714 ItemEnum(_, ref generics) |
1715 ItemTy(_, ref generics) |
1716 ItemStruct(_, ref generics) => {
1717 self.check_if_primitive_type_name(name, item.span);
1719 self.with_type_parameter_rib(HasTypeParameters(generics, TypeSpace, ItemRibKind),
1720 |this| intravisit::walk_item(this, item));
1722 ItemFn(_, _, _, _, ref generics, _) => {
1723 self.with_type_parameter_rib(HasTypeParameters(generics, FnSpace, ItemRibKind),
1724 |this| intravisit::walk_item(this, item));
1727 ItemDefaultImpl(_, ref trait_ref) => {
1728 self.with_optional_trait_ref(Some(trait_ref), |_, _| {});
1730 ItemImpl(_, _, ref generics, ref opt_trait_ref, ref self_type, ref impl_items) => {
1731 self.resolve_implementation(generics,
1738 ItemTrait(_, ref generics, ref bounds, ref trait_items) => {
1739 self.check_if_primitive_type_name(name, item.span);
1741 // Create a new rib for the trait-wide type parameters.
1742 self.with_type_parameter_rib(HasTypeParameters(generics,
1746 let local_def_id = this.ast_map.local_def_id(item.id);
1747 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
1748 this.visit_generics(generics);
1749 walk_list!(this, visit_ty_param_bound, bounds);
1751 for trait_item in trait_items {
1752 match trait_item.node {
1753 hir::ConstTraitItem(_, ref default) => {
1754 // Only impose the restrictions of
1755 // ConstRibKind if there's an actual constant
1756 // expression in a provided default.
1757 if default.is_some() {
1758 this.with_constant_rib(|this| {
1759 intravisit::walk_trait_item(this, trait_item)
1762 intravisit::walk_trait_item(this, trait_item)
1765 hir::MethodTraitItem(ref sig, _) => {
1766 let type_parameters =
1767 HasTypeParameters(&sig.generics,
1770 this.with_type_parameter_rib(type_parameters, |this| {
1771 intravisit::walk_trait_item(this, trait_item)
1774 hir::TypeTraitItem(..) => {
1775 this.check_if_primitive_type_name(trait_item.name,
1777 this.with_type_parameter_rib(NoTypeParameters, |this| {
1778 intravisit::walk_trait_item(this, trait_item)
1787 ItemMod(_) | ItemForeignMod(_) => {
1788 self.with_scope(item.id, |this| {
1789 intravisit::walk_item(this, item);
1793 ItemConst(..) | ItemStatic(..) => {
1794 self.with_constant_rib(|this| {
1795 intravisit::walk_item(this, item);
1799 ItemUse(ref view_path) => {
1800 // check for imports shadowing primitive types
1801 let check_rename = |this: &Self, id, name| {
1802 match this.def_map.borrow().get(&id).map(|d| d.full_def()) {
1803 Some(Def::Enum(..)) | Some(Def::TyAlias(..)) | Some(Def::Struct(..)) |
1804 Some(Def::Trait(..)) | None => {
1805 this.check_if_primitive_type_name(name, item.span);
1811 match view_path.node {
1812 hir::ViewPathSimple(name, _) => {
1813 check_rename(self, item.id, name);
1815 hir::ViewPathList(ref prefix, ref items) => {
1817 if let Some(name) = item.node.rename() {
1818 check_rename(self, item.node.id(), name);
1822 // Resolve prefix of an import with empty braces (issue #28388)
1823 if items.is_empty() && !prefix.segments.is_empty() {
1824 match self.resolve_crate_relative_path(prefix.span,
1828 self.record_def(item.id, PathResolution::new(def, lp, 0)),
1832 ResolutionError::FailedToResolve(
1833 &path_names_to_string(prefix, 0)));
1834 self.record_def(item.id, err_path_resolution());
1843 ItemExternCrate(_) => {
1844 // do nothing, these are just around to be encoded
1849 fn with_type_parameter_rib<'b, F>(&'b mut self, type_parameters: TypeParameters<'a, 'b>, f: F)
1850 where F: FnOnce(&mut Resolver)
1852 match type_parameters {
1853 HasTypeParameters(generics, space, rib_kind) => {
1854 let mut function_type_rib = Rib::new(rib_kind);
1855 let mut seen_bindings = HashSet::new();
1856 for (index, type_parameter) in generics.ty_params.iter().enumerate() {
1857 let name = type_parameter.name;
1858 debug!("with_type_parameter_rib: {}", type_parameter.id);
1860 if seen_bindings.contains(&name) {
1862 type_parameter.span,
1863 ResolutionError::NameAlreadyUsedInTypeParameterList(name));
1865 seen_bindings.insert(name);
1867 // plain insert (no renaming)
1868 function_type_rib.bindings
1870 DlDef(Def::TyParam(space,
1873 .local_def_id(type_parameter.id),
1876 self.type_ribs.push(function_type_rib);
1879 NoTypeParameters => {
1886 match type_parameters {
1887 HasTypeParameters(..) => {
1889 self.type_ribs.pop();
1892 NoTypeParameters => {}
1896 fn with_label_rib<F>(&mut self, f: F)
1897 where F: FnOnce(&mut Resolver)
1899 self.label_ribs.push(Rib::new(NormalRibKind));
1902 self.label_ribs.pop();
1906 fn with_constant_rib<F>(&mut self, f: F)
1907 where F: FnOnce(&mut Resolver)
1909 self.value_ribs.push(Rib::new(ConstantItemRibKind));
1910 self.type_ribs.push(Rib::new(ConstantItemRibKind));
1913 self.type_ribs.pop();
1914 self.value_ribs.pop();
1918 fn resolve_function(&mut self, rib_kind: RibKind<'a>, declaration: &FnDecl, block: &Block) {
1919 // Create a value rib for the function.
1920 self.value_ribs.push(Rib::new(rib_kind));
1922 // Create a label rib for the function.
1923 self.label_ribs.push(Rib::new(rib_kind));
1925 // Add each argument to the rib.
1926 let mut bindings_list = HashMap::new();
1927 for argument in &declaration.inputs {
1928 self.resolve_pattern(&argument.pat, ArgumentIrrefutableMode, &mut bindings_list);
1930 self.visit_ty(&argument.ty);
1932 debug!("(resolving function) recorded argument");
1934 intravisit::walk_fn_ret_ty(self, &declaration.output);
1936 // Resolve the function body.
1937 self.visit_block(block);
1939 debug!("(resolving function) leaving function");
1942 self.label_ribs.pop();
1943 self.value_ribs.pop();
1947 fn resolve_trait_reference(&mut self,
1951 -> Result<PathResolution, ()> {
1952 if let Some(path_res) = self.resolve_path(id, trait_path, path_depth, TypeNS, true) {
1953 if let Def::Trait(_) = path_res.base_def {
1954 debug!("(resolving trait) found trait def: {:?}", path_res);
1958 resolve_struct_error(self,
1960 ResolutionError::IsNotATrait(&path_names_to_string(trait_path,
1963 // If it's a typedef, give a note
1964 if let Def::TyAlias(..) = path_res.base_def {
1965 err.span_note(trait_path.span,
1966 "`type` aliases cannot be used for traits");
1974 ResolutionError::UndeclaredTraitName(&path_names_to_string(trait_path,
1980 fn resolve_generics(&mut self, generics: &Generics) {
1981 for type_parameter in generics.ty_params.iter() {
1982 self.check_if_primitive_type_name(type_parameter.name, type_parameter.span);
1984 for predicate in &generics.where_clause.predicates {
1986 &hir::WherePredicate::BoundPredicate(_) |
1987 &hir::WherePredicate::RegionPredicate(_) => {}
1988 &hir::WherePredicate::EqPredicate(ref eq_pred) => {
1989 let path_res = self.resolve_path(eq_pred.id, &eq_pred.path, 0, TypeNS, true);
1990 if let Some(PathResolution { base_def: Def::TyParam(..), .. }) = path_res {
1991 self.record_def(eq_pred.id, path_res.unwrap());
1995 ResolutionError::UndeclaredAssociatedType);
1996 self.record_def(eq_pred.id, err_path_resolution());
2001 intravisit::walk_generics(self, generics);
2004 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2005 where F: FnOnce(&mut Resolver) -> T
2007 // Handle nested impls (inside fn bodies)
2008 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2009 let result = f(self);
2010 self.current_self_type = previous_value;
2014 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
2015 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2017 let mut new_val = None;
2018 let mut new_id = None;
2019 if let Some(trait_ref) = opt_trait_ref {
2020 if let Ok(path_res) = self.resolve_trait_reference(trait_ref.ref_id,
2023 assert!(path_res.depth == 0);
2024 self.record_def(trait_ref.ref_id, path_res);
2025 new_val = Some((path_res.base_def.def_id(), trait_ref.clone()));
2026 new_id = Some(path_res.base_def.def_id());
2028 self.record_def(trait_ref.ref_id, err_path_resolution());
2030 intravisit::walk_trait_ref(self, trait_ref);
2032 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2033 let result = f(self, new_id);
2034 self.current_trait_ref = original_trait_ref;
2038 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2039 where F: FnOnce(&mut Resolver)
2041 let mut self_type_rib = Rib::new(NormalRibKind);
2043 // plain insert (no renaming, types are not currently hygienic....)
2044 let name = special_names::type_self;
2045 self_type_rib.bindings.insert(name, DlDef(self_def));
2046 self.type_ribs.push(self_type_rib);
2049 self.type_ribs.pop();
2053 fn resolve_implementation(&mut self,
2054 generics: &Generics,
2055 opt_trait_reference: &Option<TraitRef>,
2058 impl_items: &[ImplItem]) {
2059 // If applicable, create a rib for the type parameters.
2060 self.with_type_parameter_rib(HasTypeParameters(generics,
2064 // Resolve the type parameters.
2065 this.visit_generics(generics);
2067 // Resolve the trait reference, if necessary.
2068 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2069 // Resolve the self type.
2070 this.visit_ty(self_type);
2072 this.with_self_rib(Def::SelfTy(trait_id, Some((item_id, self_type.id))), |this| {
2073 this.with_current_self_type(self_type, |this| {
2074 for impl_item in impl_items {
2075 match impl_item.node {
2076 hir::ImplItemKind::Const(..) => {
2077 // If this is a trait impl, ensure the const
2079 this.check_trait_item(impl_item.name,
2081 |n, s| ResolutionError::ConstNotMemberOfTrait(n, s));
2082 this.with_constant_rib(|this| {
2083 intravisit::walk_impl_item(this, impl_item);
2086 hir::ImplItemKind::Method(ref sig, _) => {
2087 // If this is a trait impl, ensure the method
2089 this.check_trait_item(impl_item.name,
2091 |n, s| ResolutionError::MethodNotMemberOfTrait(n, s));
2093 // We also need a new scope for the method-
2094 // specific type parameters.
2095 let type_parameters =
2096 HasTypeParameters(&sig.generics,
2099 this.with_type_parameter_rib(type_parameters, |this| {
2100 intravisit::walk_impl_item(this, impl_item);
2103 hir::ImplItemKind::Type(ref ty) => {
2104 // If this is a trait impl, ensure the type
2106 this.check_trait_item(impl_item.name,
2108 |n, s| ResolutionError::TypeNotMemberOfTrait(n, s));
2120 fn check_trait_item<F>(&self, name: Name, span: Span, err: F)
2121 where F: FnOnce(Name, &str) -> ResolutionError
2123 // If there is a TraitRef in scope for an impl, then the method must be in the
2125 if let Some((did, ref trait_ref)) = self.current_trait_ref {
2126 if !self.trait_item_map.contains_key(&(name, did)) {
2127 let path_str = path_names_to_string(&trait_ref.path, 0);
2128 resolve_error(self, span, err(name, &path_str));
2133 fn resolve_local(&mut self, local: &Local) {
2134 // Resolve the type.
2135 walk_list!(self, visit_ty, &local.ty);
2137 // Resolve the initializer.
2138 walk_list!(self, visit_expr, &local.init);
2140 // Resolve the pattern.
2141 self.resolve_pattern(&local.pat, LocalIrrefutableMode, &mut HashMap::new());
2144 // build a map from pattern identifiers to binding-info's.
2145 // this is done hygienically. This could arise for a macro
2146 // that expands into an or-pattern where one 'x' was from the
2147 // user and one 'x' came from the macro.
2148 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2149 let mut result = HashMap::new();
2150 pat_bindings(&self.def_map, pat, |binding_mode, _id, sp, path1| {
2151 let name = path1.node;
2155 binding_mode: binding_mode,
2161 // check that all of the arms in an or-pattern have exactly the
2162 // same set of bindings, with the same binding modes for each.
2163 fn check_consistent_bindings(&mut self, arm: &Arm) {
2164 if arm.pats.is_empty() {
2167 let map_0 = self.binding_mode_map(&arm.pats[0]);
2168 for (i, p) in arm.pats.iter().enumerate() {
2169 let map_i = self.binding_mode_map(&p);
2171 for (&key, &binding_0) in &map_0 {
2172 match map_i.get(&key) {
2176 ResolutionError::VariableNotBoundInPattern(key, i + 1));
2178 Some(binding_i) => {
2179 if binding_0.binding_mode != binding_i.binding_mode {
2182 ResolutionError::VariableBoundWithDifferentMode(key,
2189 for (&key, &binding) in &map_i {
2190 if !map_0.contains_key(&key) {
2193 ResolutionError::VariableNotBoundInParentPattern(key, i + 1));
2199 fn resolve_arm(&mut self, arm: &Arm) {
2200 self.value_ribs.push(Rib::new(NormalRibKind));
2202 let mut bindings_list = HashMap::new();
2203 for pattern in &arm.pats {
2204 self.resolve_pattern(&pattern, RefutableMode, &mut bindings_list);
2207 // This has to happen *after* we determine which
2208 // pat_idents are variants
2209 self.check_consistent_bindings(arm);
2211 walk_list!(self, visit_expr, &arm.guard);
2212 self.visit_expr(&arm.body);
2215 self.value_ribs.pop();
2219 fn resolve_block(&mut self, block: &Block) {
2220 debug!("(resolving block) entering block");
2221 // Move down in the graph, if there's an anonymous module rooted here.
2222 let orig_module = self.current_module;
2223 let anonymous_module =
2224 orig_module.module_children.borrow().get(&block.id).map(|module| *module);
2226 if let Some(anonymous_module) = anonymous_module {
2227 debug!("(resolving block) found anonymous module, moving down");
2228 self.value_ribs.push(Rib::new(AnonymousModuleRibKind(anonymous_module)));
2229 self.type_ribs.push(Rib::new(AnonymousModuleRibKind(anonymous_module)));
2230 self.current_module = anonymous_module;
2232 self.value_ribs.push(Rib::new(NormalRibKind));
2235 // Descend into the block.
2236 intravisit::walk_block(self, block);
2240 self.current_module = orig_module;
2241 self.value_ribs.pop();
2242 if let Some(_) = anonymous_module {
2243 self.type_ribs.pop();
2246 debug!("(resolving block) leaving block");
2249 fn resolve_type(&mut self, ty: &Ty) {
2251 TyPath(ref maybe_qself, ref path) => {
2252 let resolution = match self.resolve_possibly_assoc_item(ty.id,
2253 maybe_qself.as_ref(),
2257 // `<T>::a::b::c` is resolved by typeck alone.
2258 TypecheckRequired => {
2259 // Resolve embedded types.
2260 intravisit::walk_ty(self, ty);
2263 ResolveAttempt(resolution) => resolution,
2266 // This is a path in the type namespace. Walk through scopes
2270 // Write the result into the def map.
2271 debug!("(resolving type) writing resolution for `{}` (id {}) = {:?}",
2272 path_names_to_string(path, 0),
2275 self.record_def(ty.id, def);
2278 self.record_def(ty.id, err_path_resolution());
2280 // Keep reporting some errors even if they're ignored above.
2281 self.resolve_path(ty.id, path, 0, TypeNS, true);
2283 let kind = if maybe_qself.is_some() {
2289 let self_type_name = special_idents::type_self.name;
2290 let is_invalid_self_type_name = path.segments.len() > 0 &&
2291 maybe_qself.is_none() &&
2292 path.segments[0].identifier.name ==
2294 if is_invalid_self_type_name {
2297 ResolutionError::SelfUsedOutsideImplOrTrait);
2301 ResolutionError::UseOfUndeclared(
2303 &path_names_to_string(path,
2312 // Resolve embedded types.
2313 intravisit::walk_ty(self, ty);
2316 fn resolve_pattern(&mut self,
2318 mode: PatternBindingMode,
2319 // Maps idents to the node ID for the (outermost)
2320 // pattern that binds them
2321 bindings_list: &mut HashMap<Name, NodeId>) {
2322 let pat_id = pattern.id;
2323 walk_pat(pattern, |pattern| {
2324 match pattern.node {
2325 PatKind::Ident(binding_mode, ref path1, ref at_rhs) => {
2326 // The meaning of PatKind::Ident with no type parameters
2327 // depends on whether an enum variant or unit-like struct
2328 // with that name is in scope. The probing lookup has to
2329 // be careful not to emit spurious errors. Only matching
2330 // patterns (match) can match nullary variants or
2331 // unit-like structs. For binding patterns (let
2332 // and the LHS of @-patterns), matching such a value is
2333 // simply disallowed (since it's rarely what you want).
2334 let const_ok = mode == RefutableMode && at_rhs.is_none();
2336 let ident = path1.node;
2337 let renamed = ident.name;
2339 match self.resolve_bare_identifier_pattern(ident.unhygienic_name,
2341 FoundStructOrEnumVariant(def, lp) if const_ok => {
2342 debug!("(resolving pattern) resolving `{}` to struct or enum variant",
2345 self.enforce_default_binding_mode(pattern,
2348 self.record_def(pattern.id,
2355 FoundStructOrEnumVariant(..) => {
2359 ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(
2362 self.record_def(pattern.id, err_path_resolution());
2364 FoundConst(def, lp, _) if const_ok => {
2365 debug!("(resolving pattern) resolving `{}` to constant", renamed);
2367 self.enforce_default_binding_mode(pattern, binding_mode, "a constant");
2368 self.record_def(pattern.id,
2375 FoundConst(def, _, name) => {
2379 ResolutionError::OnlyIrrefutablePatternsAllowedHere(def.def_id(),
2382 self.record_def(pattern.id, err_path_resolution());
2384 BareIdentifierPatternUnresolved => {
2385 debug!("(resolving pattern) binding `{}`", renamed);
2387 let def_id = self.ast_map.local_def_id(pattern.id);
2388 let def = Def::Local(def_id, pattern.id);
2390 // Record the definition so that later passes
2391 // will be able to distinguish variants from
2392 // locals in patterns.
2394 self.record_def(pattern.id,
2397 last_private: LastMod(AllPublic),
2401 // Add the binding to the local ribs, if it
2402 // doesn't already exist in the bindings list. (We
2403 // must not add it if it's in the bindings list
2404 // because that breaks the assumptions later
2405 // passes make about or-patterns.)
2406 if !bindings_list.contains_key(&renamed) {
2407 let this = &mut *self;
2408 let last_rib = this.value_ribs.last_mut().unwrap();
2409 last_rib.bindings.insert(renamed, DlDef(def));
2410 bindings_list.insert(renamed, pat_id);
2411 } else if mode == ArgumentIrrefutableMode &&
2412 bindings_list.contains_key(&renamed) {
2413 // Forbid duplicate bindings in the same
2418 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2419 &ident.name.as_str())
2421 } else if bindings_list.get(&renamed) == Some(&pat_id) {
2422 // Then this is a duplicate variable in the
2423 // same disjunction, which is an error.
2427 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2428 &ident.name.as_str())
2431 // Else, not bound in the same pattern: do
2437 PatKind::TupleStruct(ref path, _) | PatKind::Path(ref path) => {
2438 // This must be an enum variant, struct or const.
2439 let resolution = match self.resolve_possibly_assoc_item(pat_id,
2444 // The below shouldn't happen because all
2445 // qualified paths should be in PatKind::QPath.
2446 TypecheckRequired =>
2447 self.session.span_bug(path.span,
2448 "resolve_possibly_assoc_item claimed that a path \
2449 in PatKind::Path or PatKind::TupleStruct \
2450 requires typecheck to resolve, but qualified \
2451 paths should be PatKind::QPath"),
2452 ResolveAttempt(resolution) => resolution,
2454 if let Some(path_res) = resolution {
2455 match path_res.base_def {
2456 Def::Struct(..) if path_res.depth == 0 => {
2457 self.record_def(pattern.id, path_res);
2459 Def::Variant(..) | Def::Const(..) => {
2460 self.record_def(pattern.id, path_res);
2462 Def::Static(..) => {
2463 resolve_error(&self,
2465 ResolutionError::StaticVariableReference);
2466 self.record_def(pattern.id, err_path_resolution());
2469 // If anything ends up here entirely resolved,
2470 // it's an error. If anything ends up here
2471 // partially resolved, that's OK, because it may
2472 // be a `T::CONST` that typeck will resolve.
2473 if path_res.depth == 0 {
2477 ResolutionError::NotAnEnumVariantStructOrConst(
2485 self.record_def(pattern.id, err_path_resolution());
2487 let const_name = path.segments
2492 let traits = self.get_traits_containing_item(const_name);
2493 self.trait_map.insert(pattern.id, traits);
2494 self.record_def(pattern.id, path_res);
2502 ResolutionError::UnresolvedEnumVariantStructOrConst(
2503 &path.segments.last().unwrap().identifier.name.as_str())
2505 self.record_def(pattern.id, err_path_resolution());
2507 intravisit::walk_path(self, path);
2510 PatKind::QPath(ref qself, ref path) => {
2511 // Associated constants only.
2512 let resolution = match self.resolve_possibly_assoc_item(pat_id,
2517 TypecheckRequired => {
2518 // All `<T>::CONST` should end up here, and will
2519 // require use of the trait map to resolve
2520 // during typechecking.
2521 let const_name = path.segments
2526 let traits = self.get_traits_containing_item(const_name);
2527 self.trait_map.insert(pattern.id, traits);
2528 intravisit::walk_pat(self, pattern);
2531 ResolveAttempt(resolution) => resolution,
2533 if let Some(path_res) = resolution {
2534 match path_res.base_def {
2535 // All `<T as Trait>::CONST` should end up here, and
2536 // have the trait already selected.
2537 Def::AssociatedConst(..) => {
2538 self.record_def(pattern.id, path_res);
2544 ResolutionError::NotAnAssociatedConst(
2545 &path.segments.last().unwrap().identifier.name.as_str()
2548 self.record_def(pattern.id, err_path_resolution());
2554 ResolutionError::UnresolvedAssociatedConst(&path.segments
2560 self.record_def(pattern.id, err_path_resolution());
2562 intravisit::walk_pat(self, pattern);
2565 PatKind::Struct(ref path, _, _) => {
2566 match self.resolve_path(pat_id, path, 0, TypeNS, false) {
2567 Some(definition) => {
2568 self.record_def(pattern.id, definition);
2571 debug!("(resolving pattern) didn't find struct def: {:?}", result);
2575 ResolutionError::DoesNotNameAStruct(
2576 &path_names_to_string(path, 0))
2578 self.record_def(pattern.id, err_path_resolution());
2581 intravisit::walk_path(self, path);
2584 PatKind::Lit(_) | PatKind::Range(..) => {
2585 intravisit::walk_pat(self, pattern);
2596 fn resolve_bare_identifier_pattern(&mut self,
2599 -> BareIdentifierPatternResolution {
2600 let module = self.current_module;
2601 match self.resolve_item_in_lexical_scope(module, name, ValueNS, true) {
2602 Success(binding) => {
2603 debug!("(resolve bare identifier pattern) succeeded in finding {} at {:?}",
2606 match binding.def() {
2608 panic!("resolved name in the value namespace to a set of name bindings \
2611 // For the two success cases, this lookup can be
2612 // considered as not having a private component because
2613 // the lookup happened only within the current module.
2614 Some(def @ Def::Variant(..)) | Some(def @ Def::Struct(..)) => {
2615 return FoundStructOrEnumVariant(def, LastMod(AllPublic));
2617 Some(def @ Def::Const(..)) | Some(def @ Def::AssociatedConst(..)) => {
2618 return FoundConst(def, LastMod(AllPublic), name);
2620 Some(Def::Static(..)) => {
2621 resolve_error(self, span, ResolutionError::StaticVariableReference);
2622 return BareIdentifierPatternUnresolved;
2624 _ => return BareIdentifierPatternUnresolved
2628 Indeterminate => return BareIdentifierPatternUnresolved,
2631 Some((span, msg)) => {
2632 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
2637 debug!("(resolve bare identifier pattern) failed to find {}", name);
2638 return BareIdentifierPatternUnresolved;
2643 /// Handles paths that may refer to associated items
2644 fn resolve_possibly_assoc_item(&mut self,
2646 maybe_qself: Option<&hir::QSelf>,
2648 namespace: Namespace,
2650 -> AssocItemResolveResult {
2651 let max_assoc_types;
2655 if qself.position == 0 {
2656 return TypecheckRequired;
2658 max_assoc_types = path.segments.len() - qself.position;
2659 // Make sure the trait is valid.
2660 let _ = self.resolve_trait_reference(id, path, max_assoc_types);
2663 max_assoc_types = path.segments.len();
2667 let mut resolution = self.with_no_errors(|this| {
2668 this.resolve_path(id, path, 0, namespace, check_ribs)
2670 for depth in 1..max_assoc_types {
2671 if resolution.is_some() {
2674 self.with_no_errors(|this| {
2675 resolution = this.resolve_path(id, path, depth, TypeNS, true);
2678 if let Some(Def::Mod(_)) = resolution.map(|r| r.base_def) {
2679 // A module is not a valid type or value.
2682 ResolveAttempt(resolution)
2685 /// If `check_ribs` is true, checks the local definitions first; i.e.
2686 /// doesn't skip straight to the containing module.
2687 /// Skips `path_depth` trailing segments, which is also reflected in the
2688 /// returned value. See `middle::def::PathResolution` for more info.
2689 pub fn resolve_path(&mut self,
2693 namespace: Namespace,
2695 -> Option<PathResolution> {
2696 let span = path.span;
2697 let segments = &path.segments[..path.segments.len() - path_depth];
2699 let mk_res = |(def, lp)| PathResolution::new(def, lp, path_depth);
2702 let def = self.resolve_crate_relative_path(span, segments, namespace);
2703 return def.map(mk_res);
2706 // Try to find a path to an item in a module.
2707 let last_ident = segments.last().unwrap().identifier;
2708 if segments.len() <= 1 {
2709 let unqualified_def = self.resolve_identifier(last_ident, namespace, check_ribs, true);
2710 return unqualified_def.and_then(|def| self.adjust_local_def(def, span))
2712 PathResolution::new(def, LastMod(AllPublic), path_depth)
2716 let unqualified_def = self.resolve_identifier(last_ident, namespace, check_ribs, false);
2717 let def = self.resolve_module_relative_path(span, segments, namespace);
2718 match (def, unqualified_def) {
2719 (Some((ref d, _)), Some(ref ud)) if *d == ud.def => {
2721 .add_lint(lint::builtin::UNUSED_QUALIFICATIONS,
2724 "unnecessary qualification".to_string());
2732 // Resolve a single identifier
2733 fn resolve_identifier(&mut self,
2734 identifier: hir::Ident,
2735 namespace: Namespace,
2738 -> Option<LocalDef> {
2739 if identifier.name == special_idents::invalid.name {
2740 return Some(LocalDef::from_def(Def::Err));
2743 // First, check to see whether the name is a primitive type.
2744 if namespace == TypeNS {
2745 if let Some(&prim_ty) = self.primitive_type_table
2747 .get(&identifier.unhygienic_name) {
2748 return Some(LocalDef::from_def(Def::PrimTy(prim_ty)));
2753 if let Some(def) = self.resolve_identifier_in_local_ribs(identifier, namespace) {
2759 let module = self.current_module;
2760 let name = identifier.unhygienic_name;
2761 match self.resolve_item_in_lexical_scope(module, name, namespace, record_used) {
2762 Success(binding) => binding.def().map(LocalDef::from_def),
2763 Failed(Some((span, msg))) => {
2764 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
2771 // Resolve a local definition, potentially adjusting for closures.
2772 fn adjust_local_def(&mut self, local_def: LocalDef, span: Span) -> Option<Def> {
2773 let ribs = match local_def.ribs {
2774 Some((TypeNS, i)) => &self.type_ribs[i + 1..],
2775 Some((ValueNS, i)) => &self.value_ribs[i + 1..],
2778 let mut def = local_def.def;
2781 self.session.span_bug(span, &format!("unexpected {:?} in bindings", def))
2783 Def::Local(_, node_id) => {
2786 NormalRibKind | AnonymousModuleRibKind(..) => {
2787 // Nothing to do. Continue.
2789 ClosureRibKind(function_id) => {
2791 let node_def_id = self.ast_map.local_def_id(node_id);
2793 let seen = self.freevars_seen
2795 .or_insert_with(|| NodeMap());
2796 if let Some(&index) = seen.get(&node_id) {
2797 def = Def::Upvar(node_def_id, node_id, index, function_id);
2800 let vec = self.freevars
2802 .or_insert_with(|| vec![]);
2803 let depth = vec.len();
2809 def = Def::Upvar(node_def_id, node_id, depth, function_id);
2810 seen.insert(node_id, depth);
2812 ItemRibKind | MethodRibKind => {
2813 // This was an attempt to access an upvar inside a
2814 // named function item. This is not allowed, so we
2818 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
2821 ConstantItemRibKind => {
2822 // Still doesn't deal with upvars
2825 ResolutionError::AttemptToUseNonConstantValueInConstant);
2831 Def::TyParam(..) | Def::SelfTy(..) => {
2834 NormalRibKind | MethodRibKind | ClosureRibKind(..) |
2835 AnonymousModuleRibKind(..) => {
2836 // Nothing to do. Continue.
2839 // This was an attempt to use a type parameter outside
2844 ResolutionError::TypeParametersFromOuterFunction);
2847 ConstantItemRibKind => {
2849 resolve_error(self, span, ResolutionError::OuterTypeParameterContext);
2860 // resolve a "module-relative" path, e.g. a::b::c
2861 fn resolve_module_relative_path(&mut self,
2863 segments: &[hir::PathSegment],
2864 namespace: Namespace)
2865 -> Option<(Def, LastPrivate)> {
2866 let module_path = segments.split_last()
2870 .map(|ps| ps.identifier.name)
2871 .collect::<Vec<_>>();
2873 let containing_module;
2875 let current_module = self.current_module;
2876 match self.resolve_module_path(current_module, &module_path, UseLexicalScope, span) {
2878 let (span, msg) = match err {
2879 Some((span, msg)) => (span, msg),
2881 let msg = format!("Use of undeclared type or module `{}`",
2882 names_to_string(&module_path));
2887 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
2890 Indeterminate => return None,
2891 Success((resulting_module, resulting_last_private)) => {
2892 containing_module = resulting_module;
2893 last_private = resulting_last_private;
2897 let name = segments.last().unwrap().identifier.name;
2898 let result = self.resolve_name_in_module(containing_module, name, namespace, false, true);
2899 let def = match result {
2900 Success(binding) => {
2901 let (def, lp) = binding.def_and_lp();
2902 (def, last_private.or(lp))
2909 /// Invariant: This must be called only during main resolution, not during
2910 /// import resolution.
2911 fn resolve_crate_relative_path(&mut self,
2913 segments: &[hir::PathSegment],
2914 namespace: Namespace)
2915 -> Option<(Def, LastPrivate)> {
2916 let module_path = segments.split_last()
2920 .map(|ps| ps.identifier.name)
2921 .collect::<Vec<_>>();
2923 let root_module = self.graph_root;
2925 let containing_module;
2927 match self.resolve_module_path_from_root(root_module,
2931 LastMod(AllPublic)) {
2933 let (span, msg) = match err {
2934 Some((span, msg)) => (span, msg),
2936 let msg = format!("Use of undeclared module `::{}`",
2937 names_to_string(&module_path));
2942 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
2946 Indeterminate => return None,
2948 Success((resulting_module, resulting_last_private)) => {
2949 containing_module = resulting_module;
2950 last_private = resulting_last_private;
2954 let name = segments.last().unwrap().identifier.name;
2955 match self.resolve_name_in_module(containing_module, name, namespace, false, true) {
2956 Success(binding) => {
2957 let (def, lp) = binding.def_and_lp();
2958 Some((def, last_private.or(lp)))
2964 fn resolve_identifier_in_local_ribs(&mut self,
2966 namespace: Namespace)
2967 -> Option<LocalDef> {
2968 // Check the local set of ribs.
2969 let name = match namespace { ValueNS => ident.name, TypeNS => ident.unhygienic_name };
2971 for i in (0 .. self.get_ribs(namespace).len()).rev() {
2972 if let Some(def_like) = self.get_ribs(namespace)[i].bindings.get(&name).cloned() {
2975 debug!("(resolving path in local ribs) resolved `{}` to {:?} at {}",
2979 return Some(LocalDef {
2980 ribs: Some((namespace, i)),
2985 debug!("(resolving path in local ribs) resolved `{}` to pseudo-def {:?}",
2993 if let AnonymousModuleRibKind(module) = self.get_ribs(namespace)[i].kind {
2994 if let Success(binding) = self.resolve_name_in_module(module,
2995 ident.unhygienic_name,
2999 if let Some(def) = binding.def() {
3000 return Some(LocalDef::from_def(def));
3009 fn with_no_errors<T, F>(&mut self, f: F) -> T
3010 where F: FnOnce(&mut Resolver) -> T
3012 self.emit_errors = false;
3014 self.emit_errors = true;
3018 fn find_fallback_in_self_type(&mut self, name: Name) -> FallbackSuggestion {
3019 fn extract_path_and_node_id(t: &Ty,
3020 allow: FallbackChecks)
3021 -> Option<(Path, NodeId, FallbackChecks)> {
3023 TyPath(None, ref path) => Some((path.clone(), t.id, allow)),
3024 TyPtr(ref mut_ty) => extract_path_and_node_id(&mut_ty.ty, OnlyTraitAndStatics),
3025 TyRptr(_, ref mut_ty) => extract_path_and_node_id(&mut_ty.ty, allow),
3026 // This doesn't handle the remaining `Ty` variants as they are not
3027 // that commonly the self_type, it might be interesting to provide
3028 // support for those in future.
3033 fn get_module<'a, 'tcx>(this: &mut Resolver<'a, 'tcx>,
3035 name_path: &[ast::Name])
3036 -> Option<Module<'a>> {
3037 let root = this.current_module;
3038 let last_name = name_path.last().unwrap();
3040 if name_path.len() == 1 {
3041 match this.primitive_type_table.primitive_types.get(last_name) {
3043 None => this.current_module.resolve_name(*last_name, TypeNS, true).success()
3044 .and_then(NameBinding::module)
3047 match this.resolve_module_path(root, &name_path, UseLexicalScope, span) {
3048 Success((module, _)) => Some(module),
3054 fn is_static_method(this: &Resolver, did: DefId) -> bool {
3055 if let Some(node_id) = this.ast_map.as_local_node_id(did) {
3056 let sig = match this.ast_map.get(node_id) {
3057 hir_map::NodeTraitItem(trait_item) => match trait_item.node {
3058 hir::MethodTraitItem(ref sig, _) => sig,
3061 hir_map::NodeImplItem(impl_item) => match impl_item.node {
3062 hir::ImplItemKind::Method(ref sig, _) => sig,
3067 sig.explicit_self.node == hir::SelfStatic
3069 this.session.cstore.is_static_method(did)
3073 let (path, node_id, allowed) = match self.current_self_type {
3074 Some(ref ty) => match extract_path_and_node_id(ty, Everything) {
3076 None => return NoSuggestion,
3078 None => return NoSuggestion,
3081 if allowed == Everything {
3082 // Look for a field with the same name in the current self_type.
3083 match self.def_map.borrow().get(&node_id).map(|d| d.full_def()) {
3084 Some(Def::Enum(did)) |
3085 Some(Def::TyAlias(did)) |
3086 Some(Def::Struct(did)) |
3087 Some(Def::Variant(_, did)) => match self.structs.get(&did) {
3090 if fields.iter().any(|&field_name| name == field_name) {
3095 _ => {} // Self type didn't resolve properly
3099 let name_path = path.segments.iter().map(|seg| seg.identifier.name).collect::<Vec<_>>();
3101 // Look for a method in the current self type's impl module.
3102 if let Some(module) = get_module(self, path.span, &name_path) {
3103 if let Success(binding) = module.resolve_name(name, ValueNS, true) {
3104 if let Some(Def::Method(did)) = binding.def() {
3105 if is_static_method(self, did) {
3106 return StaticMethod(path_names_to_string(&path, 0));
3108 if self.current_trait_ref.is_some() {
3110 } else if allowed == Everything {
3117 // Look for a method in the current trait.
3118 if let Some((trait_did, ref trait_ref)) = self.current_trait_ref {
3119 if let Some(&did) = self.trait_item_map.get(&(name, trait_did)) {
3120 if is_static_method(self, did) {
3121 return TraitMethod(path_names_to_string(&trait_ref.path, 0));
3131 fn find_best_match(&mut self, name: &str) -> SuggestionType {
3132 if let Some(macro_name) = self.session.available_macros
3133 .borrow().iter().find(|n| n.as_str() == name) {
3134 return SuggestionType::Macro(format!("{}!", macro_name));
3137 let names = self.value_ribs
3140 .flat_map(|rib| rib.bindings.keys());
3142 if let Some(found) = find_best_match_for_name(names, name, None) {
3144 return SuggestionType::Function(found);
3146 } SuggestionType::NotFound
3149 fn resolve_expr(&mut self, expr: &Expr) {
3150 // First, record candidate traits for this expression if it could
3151 // result in the invocation of a method call.
3153 self.record_candidate_traits_for_expr_if_necessary(expr);
3155 // Next, resolve the node.
3157 ExprPath(ref maybe_qself, ref path) => {
3158 let resolution = match self.resolve_possibly_assoc_item(expr.id,
3159 maybe_qself.as_ref(),
3163 // `<T>::a::b::c` is resolved by typeck alone.
3164 TypecheckRequired => {
3165 let method_name = path.segments.last().unwrap().identifier.name;
3166 let traits = self.get_traits_containing_item(method_name);
3167 self.trait_map.insert(expr.id, traits);
3168 intravisit::walk_expr(self, expr);
3171 ResolveAttempt(resolution) => resolution,
3174 // This is a local path in the value namespace. Walk through
3175 // scopes looking for it.
3176 if let Some(path_res) = resolution {
3177 // Check if struct variant
3178 let is_struct_variant = if let Def::Variant(_, variant_id) = path_res.base_def {
3179 self.structs.contains_key(&variant_id)
3183 if is_struct_variant {
3184 let _ = self.structs.contains_key(&path_res.base_def.def_id());
3185 let path_name = path_names_to_string(path, 0);
3187 let mut err = resolve_struct_error(self,
3189 ResolutionError::StructVariantUsedAsFunction(&path_name));
3191 let msg = format!("did you mean to write: `{} {{ /* fields */ }}`?",
3193 if self.emit_errors {
3194 err.fileline_help(expr.span, &msg);
3196 err.span_help(expr.span, &msg);
3199 self.record_def(expr.id, err_path_resolution());
3201 // Write the result into the def map.
3202 debug!("(resolving expr) resolved `{}`",
3203 path_names_to_string(path, 0));
3205 // Partial resolutions will need the set of traits in scope,
3206 // so they can be completed during typeck.
3207 if path_res.depth != 0 {
3208 let method_name = path.segments.last().unwrap().identifier.name;
3209 let traits = self.get_traits_containing_item(method_name);
3210 self.trait_map.insert(expr.id, traits);
3213 self.record_def(expr.id, path_res);
3216 // Be helpful if the name refers to a struct
3217 // (The pattern matching def_tys where the id is in self.structs
3218 // matches on regular structs while excluding tuple- and enum-like
3219 // structs, which wouldn't result in this error.)
3220 let path_name = path_names_to_string(path, 0);
3221 let type_res = self.with_no_errors(|this| {
3222 this.resolve_path(expr.id, path, 0, TypeNS, false)
3225 self.record_def(expr.id, err_path_resolution());
3226 match type_res.map(|r| r.base_def) {
3227 Some(Def::Struct(..)) => {
3228 let mut err = resolve_struct_error(self,
3230 ResolutionError::StructVariantUsedAsFunction(&path_name));
3232 let msg = format!("did you mean to write: `{} {{ /* fields */ }}`?",
3234 if self.emit_errors {
3235 err.fileline_help(expr.span, &msg);
3237 err.span_help(expr.span, &msg);
3242 // Keep reporting some errors even if they're ignored above.
3243 self.resolve_path(expr.id, path, 0, ValueNS, true);
3245 let mut method_scope = false;
3246 self.value_ribs.iter().rev().all(|rib| {
3247 method_scope = match rib.kind {
3248 MethodRibKind => true,
3249 ItemRibKind | ConstantItemRibKind => false,
3250 _ => return true, // Keep advancing
3252 false // Stop advancing
3255 if method_scope && special_names::self_.as_str() == &path_name[..] {
3258 ResolutionError::SelfNotAvailableInStaticMethod);
3260 let last_name = path.segments.last().unwrap().identifier.name;
3261 let mut msg = match self.find_fallback_in_self_type(last_name) {
3263 // limit search to 5 to reduce the number
3264 // of stupid suggestions
3265 match self.find_best_match(&path_name) {
3266 SuggestionType::Macro(s) => {
3267 format!("the macro `{}`", s)
3269 SuggestionType::Function(s) => format!("`{}`", s),
3270 SuggestionType::NotFound => "".to_string(),
3273 Field => format!("`self.{}`", path_name),
3275 TraitItem => format!("to call `self.{}`", path_name),
3276 TraitMethod(path_str) |
3277 StaticMethod(path_str) =>
3278 format!("to call `{}::{}`", path_str, path_name),
3281 let mut context = UnresolvedNameContext::Other;
3282 if !msg.is_empty() {
3283 msg = format!(". Did you mean {}?", msg);
3285 // we check if this a module and if so, we display a help
3287 let name_path = path.segments.iter()
3288 .map(|seg| seg.identifier.name)
3289 .collect::<Vec<_>>();
3290 let current_module = self.current_module;
3292 match self.resolve_module_path(current_module,
3297 context = UnresolvedNameContext::PathIsMod(expr.id);
3305 ResolutionError::UnresolvedName(
3306 &path_name, &msg, context));
3312 intravisit::walk_expr(self, expr);
3315 ExprStruct(ref path, _, _) => {
3316 // Resolve the path to the structure it goes to. We don't
3317 // check to ensure that the path is actually a structure; that
3318 // is checked later during typeck.
3319 match self.resolve_path(expr.id, path, 0, TypeNS, false) {
3320 Some(definition) => self.record_def(expr.id, definition),
3322 debug!("(resolving expression) didn't find struct def",);
3326 ResolutionError::DoesNotNameAStruct(
3327 &path_names_to_string(path, 0))
3329 self.record_def(expr.id, err_path_resolution());
3333 intravisit::walk_expr(self, expr);
3336 ExprLoop(_, Some(label)) | ExprWhile(_, _, Some(label)) => {
3337 self.with_label_rib(|this| {
3338 let def_like = DlDef(Def::Label(expr.id));
3341 let rib = this.label_ribs.last_mut().unwrap();
3342 rib.bindings.insert(label.name, def_like);
3345 intravisit::walk_expr(this, expr);
3349 ExprBreak(Some(label)) | ExprAgain(Some(label)) => {
3350 match self.search_label(label.node.name) {
3352 self.record_def(expr.id, err_path_resolution());
3355 ResolutionError::UndeclaredLabel(&label.node.name.as_str()))
3357 Some(DlDef(def @ Def::Label(_))) => {
3358 // Since this def is a label, it is never read.
3359 self.record_def(expr.id,
3362 last_private: LastMod(AllPublic),
3367 self.session.span_bug(expr.span, "label wasn't mapped to a label def!")
3373 intravisit::walk_expr(self, expr);
3378 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3380 ExprField(_, name) => {
3381 // FIXME(#6890): Even though you can't treat a method like a
3382 // field, we need to add any trait methods we find that match
3383 // the field name so that we can do some nice error reporting
3384 // later on in typeck.
3385 let traits = self.get_traits_containing_item(name.node);
3386 self.trait_map.insert(expr.id, traits);
3388 ExprMethodCall(name, _, _) => {
3389 debug!("(recording candidate traits for expr) recording traits for {}",
3391 let traits = self.get_traits_containing_item(name.node);
3392 self.trait_map.insert(expr.id, traits);
3400 fn get_traits_containing_item(&mut self, name: Name) -> Vec<DefId> {
3401 debug!("(getting traits containing item) looking for '{}'", name);
3403 fn add_trait_info(found_traits: &mut Vec<DefId>, trait_def_id: DefId, name: Name) {
3404 debug!("(adding trait info) found trait {:?} for method '{}'",
3407 found_traits.push(trait_def_id);
3410 let mut found_traits = Vec::new();
3411 let mut search_module = self.current_module;
3413 // Look for the current trait.
3414 match self.current_trait_ref {
3415 Some((trait_def_id, _)) => {
3416 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3417 add_trait_info(&mut found_traits, trait_def_id, name);
3420 None => {} // Nothing to do.
3423 // Look for trait children.
3424 build_reduced_graph::populate_module_if_necessary(self, &search_module);
3426 search_module.for_each_child(|_, ns, name_binding| {
3427 if ns != TypeNS { return }
3428 let trait_def_id = match name_binding.def() {
3429 Some(Def::Trait(trait_def_id)) => trait_def_id,
3430 Some(..) | None => return,
3432 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3433 add_trait_info(&mut found_traits, trait_def_id, name);
3434 let trait_name = self.get_trait_name(trait_def_id);
3435 self.record_use(trait_name, TypeNS, name_binding);
3439 // Look for shadowed traits.
3440 for binding in search_module.shadowed_traits.borrow().iter() {
3441 let did = binding.def().unwrap().def_id();
3442 if self.trait_item_map.contains_key(&(name, did)) {
3443 add_trait_info(&mut found_traits, did, name);
3444 let trait_name = self.get_trait_name(did);
3445 self.record_use(trait_name, TypeNS, binding);
3449 match search_module.parent_link {
3450 NoParentLink | ModuleParentLink(..) => break,
3451 BlockParentLink(parent_module, _) => {
3452 search_module = parent_module;
3460 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
3461 debug!("(recording def) recording {:?} for {}", resolution, node_id);
3462 assert!(match resolution.last_private {
3463 LastImport{..} => false,
3466 "Import should only be used for `use` directives");
3468 if let Some(prev_res) = self.def_map.borrow_mut().insert(node_id, resolution) {
3469 let span = self.ast_map.opt_span(node_id).unwrap_or(codemap::DUMMY_SP);
3470 self.session.span_bug(span,
3471 &format!("path resolved multiple times ({:?} before, {:?} now)",
3477 fn enforce_default_binding_mode(&mut self,
3479 pat_binding_mode: BindingMode,
3481 match pat_binding_mode {
3482 BindByValue(_) => {}
3486 ResolutionError::CannotUseRefBindingModeWith(descr));
3493 fn names_to_string(names: &[Name]) -> String {
3494 let mut first = true;
3495 let mut result = String::new();
3500 result.push_str("::")
3502 result.push_str(&name.as_str());
3507 fn path_names_to_string(path: &Path, depth: usize) -> String {
3508 let names: Vec<ast::Name> = path.segments[..path.segments.len() - depth]
3510 .map(|seg| seg.identifier.name)
3512 names_to_string(&names[..])
3515 /// A somewhat inefficient routine to obtain the name of a module.
3516 fn module_to_string<'a>(module: Module<'a>) -> String {
3517 let mut names = Vec::new();
3519 fn collect_mod<'a>(names: &mut Vec<ast::Name>, module: Module<'a>) {
3520 match module.parent_link {
3522 ModuleParentLink(ref module, name) => {
3524 collect_mod(names, module);
3526 BlockParentLink(ref module, _) => {
3527 // danger, shouldn't be ident?
3528 names.push(special_idents::opaque.name);
3529 collect_mod(names, module);
3533 collect_mod(&mut names, module);
3535 if names.is_empty() {
3536 return "???".to_string();
3538 names_to_string(&names.into_iter().rev().collect::<Vec<ast::Name>>())
3541 fn err_path_resolution() -> PathResolution {
3544 last_private: LastMod(AllPublic),
3550 pub struct CrateMap {
3551 pub def_map: RefCell<DefMap>,
3552 pub freevars: FreevarMap,
3553 pub export_map: ExportMap,
3554 pub trait_map: TraitMap,
3555 pub external_exports: ExternalExports,
3556 pub glob_map: Option<GlobMap>,
3559 #[derive(PartialEq,Copy, Clone)]
3560 pub enum MakeGlobMap {
3565 /// Entry point to crate resolution.
3566 pub fn resolve_crate<'a, 'tcx>(session: &'a Session,
3567 ast_map: &'a hir_map::Map<'tcx>,
3568 make_glob_map: MakeGlobMap)
3570 // Currently, we ignore the name resolution data structures for
3571 // the purposes of dependency tracking. Instead we will run name
3572 // resolution and include its output in the hash of each item,
3573 // much like we do for macro expansion. In other words, the hash
3574 // reflects not just its contents but the results of name
3575 // resolution on those contents. Hopefully we'll push this back at
3577 let _task = ast_map.dep_graph.in_task(DepNode::Resolve);
3579 let krate = ast_map.krate();
3580 let arenas = Resolver::arenas();
3581 let mut resolver = create_resolver(session, ast_map, krate, make_glob_map, &arenas, None);
3583 resolver.resolve_crate(krate);
3585 check_unused::check_crate(&mut resolver, krate);
3588 def_map: resolver.def_map,
3589 freevars: resolver.freevars,
3590 export_map: resolver.export_map,
3591 trait_map: resolver.trait_map,
3592 external_exports: resolver.external_exports,
3593 glob_map: if resolver.make_glob_map {
3594 Some(resolver.glob_map)
3601 /// Builds a name resolution walker to be used within this module,
3602 /// or used externally, with an optional callback function.
3604 /// The callback takes a &mut bool which allows callbacks to end a
3605 /// walk when set to true, passing through the rest of the walk, while
3606 /// preserving the ribs + current module. This allows resolve_path
3607 /// calls to be made with the correct scope info. The node in the
3608 /// callback corresponds to the current node in the walk.
3609 pub fn create_resolver<'a, 'tcx>(session: &'a Session,
3610 ast_map: &'a hir_map::Map<'tcx>,
3612 make_glob_map: MakeGlobMap,
3613 arenas: &'a ResolverArenas<'a>,
3614 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>)
3615 -> Resolver<'a, 'tcx> {
3616 let mut resolver = Resolver::new(session, ast_map, make_glob_map, arenas);
3618 resolver.callback = callback;
3620 build_reduced_graph::build_reduced_graph(&mut resolver, krate);
3622 resolve_imports::resolve_imports(&mut resolver);
3627 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }