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::NamespaceResult::*;
40 use self::ResolveResult::*;
41 use self::FallbackSuggestion::*;
42 use self::TypeParameters::*;
44 use self::UseLexicalScopeFlag::*;
45 use self::ModulePrefixResult::*;
46 use self::AssocItemResolveResult::*;
47 use self::NameSearchType::*;
48 use self::BareIdentifierPatternResolution::*;
49 use self::ParentLink::*;
50 use self::FallbackChecks::*;
52 use rustc::front::map as hir_map;
53 use rustc::session::Session;
55 use rustc::middle::cstore::{CrateStore, DefLike, DlDef};
56 use rustc::middle::def::*;
57 use rustc::middle::def_id::DefId;
58 use rustc::middle::pat_util::pat_bindings;
59 use rustc::middle::privacy::*;
60 use rustc::middle::subst::{ParamSpace, FnSpace, TypeSpace};
61 use rustc::middle::ty::{Freevar, FreevarMap, TraitMap, GlobMap};
62 use rustc::util::nodemap::{NodeMap, DefIdSet, FnvHashMap};
65 use syntax::ast::{CRATE_NODE_ID, Name, NodeId, CrateNum, TyIs, TyI8, TyI16, TyI32, TyI64};
66 use syntax::ast::{TyUs, TyU8, TyU16, TyU32, TyU64, TyF64, TyF32};
67 use syntax::attr::AttrMetaMethods;
68 use syntax::codemap::{self, Span, Pos};
69 use syntax::errors::DiagnosticBuilder;
70 use syntax::parse::token::{self, special_names, special_idents};
71 use syntax::util::lev_distance::find_best_match_for_name;
73 use rustc_front::intravisit::{self, FnKind, Visitor};
75 use rustc_front::hir::{Arm, BindByRef, BindByValue, BindingMode, Block};
76 use rustc_front::hir::Crate;
77 use rustc_front::hir::{Expr, ExprAgain, ExprBreak, ExprCall, ExprField};
78 use rustc_front::hir::{ExprLoop, ExprWhile, ExprMethodCall};
79 use rustc_front::hir::{ExprPath, ExprStruct, FnDecl};
80 use rustc_front::hir::{ForeignItemFn, ForeignItemStatic, Generics};
81 use rustc_front::hir::{ImplItem, Item, ItemConst, ItemEnum, ItemExternCrate};
82 use rustc_front::hir::{ItemFn, ItemForeignMod, ItemImpl, ItemMod, ItemStatic, ItemDefaultImpl};
83 use rustc_front::hir::{ItemStruct, ItemTrait, ItemTy, ItemUse};
84 use rustc_front::hir::Local;
85 use rustc_front::hir::{Pat, PatEnum, PatIdent, PatLit, PatQPath};
86 use rustc_front::hir::{PatRange, PatStruct, Path, PrimTy};
87 use rustc_front::hir::{TraitRef, Ty, TyBool, TyChar, TyFloat, TyInt};
88 use rustc_front::hir::{TyRptr, TyStr, TyUint, TyPath, TyPtr};
89 use rustc_front::util::walk_pat;
91 use std::collections::{HashMap, HashSet};
92 use std::cell::{Cell, RefCell};
94 use std::mem::replace;
97 use resolve_imports::{Target, ImportDirective, ImportResolutionPerNamespace};
98 use resolve_imports::Shadowable;
100 // NB: This module needs to be declared first so diagnostics are
101 // registered before they are used.
105 mod build_reduced_graph;
108 // Perform the callback, not walking deeper if the return is true
109 macro_rules! execute_callback {
110 ($node: expr, $walker: expr) => (
111 if let Some(ref callback) = $walker.callback {
112 if callback($node, &mut $walker.resolved) {
119 enum SuggestionType {
121 Function(token::InternedString),
125 pub enum ResolutionError<'a> {
126 /// error E0260: name conflicts with an extern crate
127 NameConflictsWithExternCrate(Name),
128 /// error E0401: can't use type parameters from outer function
129 TypeParametersFromOuterFunction,
130 /// error E0402: cannot use an outer type parameter in this context
131 OuterTypeParameterContext,
132 /// error E0403: the name is already used for a type parameter in this type parameter list
133 NameAlreadyUsedInTypeParameterList(Name),
134 /// error E0404: is not a trait
135 IsNotATrait(&'a str),
136 /// error E0405: use of undeclared trait name
137 UndeclaredTraitName(&'a str),
138 /// error E0406: undeclared associated type
139 UndeclaredAssociatedType,
140 /// error E0407: method is not a member of trait
141 MethodNotMemberOfTrait(Name, &'a str),
142 /// error E0437: type is not a member of trait
143 TypeNotMemberOfTrait(Name, &'a str),
144 /// error E0438: const is not a member of trait
145 ConstNotMemberOfTrait(Name, &'a str),
146 /// error E0408: variable `{}` from pattern #1 is not bound in pattern
147 VariableNotBoundInPattern(Name, usize),
148 /// error E0409: variable is bound with different mode in pattern #{} than in pattern #1
149 VariableBoundWithDifferentMode(Name, usize),
150 /// error E0410: variable from pattern is not bound in pattern #1
151 VariableNotBoundInParentPattern(Name, usize),
152 /// error E0411: use of `Self` outside of an impl or trait
153 SelfUsedOutsideImplOrTrait,
154 /// error E0412: use of undeclared
155 UseOfUndeclared(&'a str, &'a str),
156 /// error E0413: declaration shadows an enum variant or unit-like struct in scope
157 DeclarationShadowsEnumVariantOrUnitLikeStruct(Name),
158 /// error E0414: only irrefutable patterns allowed here
159 OnlyIrrefutablePatternsAllowedHere(DefId, Name),
160 /// error E0415: identifier is bound more than once in this parameter list
161 IdentifierBoundMoreThanOnceInParameterList(&'a str),
162 /// error E0416: identifier is bound more than once in the same pattern
163 IdentifierBoundMoreThanOnceInSamePattern(&'a str),
164 /// error E0417: static variables cannot be referenced in a pattern
165 StaticVariableReference,
166 /// error E0418: is not an enum variant, struct or const
167 NotAnEnumVariantStructOrConst(&'a str),
168 /// error E0419: unresolved enum variant, struct or const
169 UnresolvedEnumVariantStructOrConst(&'a str),
170 /// error E0420: is not an associated const
171 NotAnAssociatedConst(&'a str),
172 /// error E0421: unresolved associated const
173 UnresolvedAssociatedConst(&'a str),
174 /// error E0422: does not name a struct
175 DoesNotNameAStruct(&'a str),
176 /// error E0423: is a struct variant name, but this expression uses it like a function name
177 StructVariantUsedAsFunction(&'a str),
178 /// error E0424: `self` is not available in a static method
179 SelfNotAvailableInStaticMethod,
180 /// error E0425: unresolved name
181 UnresolvedName(&'a str, &'a str, UnresolvedNameContext),
182 /// error E0426: use of undeclared label
183 UndeclaredLabel(&'a str),
184 /// error E0427: cannot use `ref` binding mode with ...
185 CannotUseRefBindingModeWith(&'a str),
186 /// error E0428: duplicate definition
187 DuplicateDefinition(&'a str, Name),
188 /// error E0429: `self` imports are only allowed within a { } list
189 SelfImportsOnlyAllowedWithin,
190 /// error E0430: `self` import can only appear once in the list
191 SelfImportCanOnlyAppearOnceInTheList,
192 /// error E0431: `self` import can only appear in an import list with a non-empty prefix
193 SelfImportOnlyInImportListWithNonEmptyPrefix,
194 /// error E0432: unresolved import
195 UnresolvedImport(Option<(&'a str, &'a str)>),
196 /// error E0433: failed to resolve
197 FailedToResolve(&'a str),
198 /// error E0434: can't capture dynamic environment in a fn item
199 CannotCaptureDynamicEnvironmentInFnItem,
200 /// error E0435: attempt to use a non-constant value in a constant
201 AttemptToUseNonConstantValueInConstant,
204 /// Context of where `ResolutionError::UnresolvedName` arose.
205 #[derive(Clone, PartialEq, Eq, Debug)]
206 pub enum UnresolvedNameContext {
207 /// `PathIsMod(id)` indicates that a given path, used in
208 /// expression context, actually resolved to a module rather than
209 /// a value. The `id` attached to the variant is the node id of
210 /// the erroneous path expression.
211 PathIsMod(ast::NodeId),
213 /// `Other` means we have no extra information about the context
214 /// of the unresolved name error. (Maybe we could eliminate all
215 /// such cases; but for now, this is an information-free default.)
219 fn resolve_error<'b, 'a: 'b, 'tcx: 'a>(resolver: &'b Resolver<'a, 'tcx>,
220 span: syntax::codemap::Span,
221 resolution_error: ResolutionError<'b>) {
222 resolve_struct_error(resolver, span, resolution_error).emit();
225 fn resolve_struct_error<'b, 'a: 'b, 'tcx: 'a>(resolver: &'b Resolver<'a, 'tcx>,
226 span: syntax::codemap::Span,
227 resolution_error: ResolutionError<'b>)
228 -> DiagnosticBuilder<'a> {
229 if !resolver.emit_errors {
230 return resolver.session.diagnostic().struct_dummy();
233 match resolution_error {
234 ResolutionError::NameConflictsWithExternCrate(name) => {
235 struct_span_err!(resolver.session,
238 "the name `{}` conflicts with an external crate \
239 that has been imported into this module",
242 ResolutionError::TypeParametersFromOuterFunction => {
243 struct_span_err!(resolver.session,
246 "can't use type parameters from outer function; try using a local \
247 type parameter instead")
249 ResolutionError::OuterTypeParameterContext => {
250 struct_span_err!(resolver.session,
253 "cannot use an outer type parameter in this context")
255 ResolutionError::NameAlreadyUsedInTypeParameterList(name) => {
256 struct_span_err!(resolver.session,
259 "the name `{}` is already used for a type parameter in this type \
263 ResolutionError::IsNotATrait(name) => {
264 struct_span_err!(resolver.session, span, E0404, "`{}` is not a trait", name)
266 ResolutionError::UndeclaredTraitName(name) => {
267 struct_span_err!(resolver.session,
270 "use of undeclared trait name `{}`",
273 ResolutionError::UndeclaredAssociatedType => {
274 struct_span_err!(resolver.session, span, E0406, "undeclared associated type")
276 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
277 struct_span_err!(resolver.session,
280 "method `{}` is not a member of trait `{}`",
284 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
285 struct_span_err!(resolver.session,
288 "type `{}` is not a member of trait `{}`",
292 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
293 struct_span_err!(resolver.session,
296 "const `{}` is not a member of trait `{}`",
300 ResolutionError::VariableNotBoundInPattern(variable_name, pattern_number) => {
301 struct_span_err!(resolver.session,
304 "variable `{}` from pattern #1 is not bound in pattern #{}",
308 ResolutionError::VariableBoundWithDifferentMode(variable_name, pattern_number) => {
309 struct_span_err!(resolver.session,
312 "variable `{}` is bound with different mode in pattern #{} than in \
317 ResolutionError::VariableNotBoundInParentPattern(variable_name, pattern_number) => {
318 struct_span_err!(resolver.session,
321 "variable `{}` from pattern #{} is not bound in pattern #1",
325 ResolutionError::SelfUsedOutsideImplOrTrait => {
326 struct_span_err!(resolver.session,
329 "use of `Self` outside of an impl or trait")
331 ResolutionError::UseOfUndeclared(kind, name) => {
332 struct_span_err!(resolver.session,
335 "use of undeclared {} `{}`",
339 ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(name) => {
340 struct_span_err!(resolver.session,
343 "declaration of `{}` shadows an enum variant \
344 or unit-like struct in scope",
347 ResolutionError::OnlyIrrefutablePatternsAllowedHere(did, name) => {
348 let mut err = struct_span_err!(resolver.session,
351 "only irrefutable patterns allowed here");
353 "there already is a constant in scope sharing the same \
354 name as this pattern");
355 if let Some(sp) = resolver.ast_map.span_if_local(did) {
356 err.span_note(sp, "constant defined here");
358 if let Some(directive) = resolver.current_module
362 let item = resolver.ast_map.expect_item(directive.value_ns.id);
363 err.span_note(item.span, "constant imported here");
367 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
368 struct_span_err!(resolver.session,
371 "identifier `{}` is bound more than once in this parameter list",
374 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
375 struct_span_err!(resolver.session,
378 "identifier `{}` is bound more than once in the same pattern",
381 ResolutionError::StaticVariableReference => {
382 struct_span_err!(resolver.session,
385 "static variables cannot be referenced in a pattern, use a \
388 ResolutionError::NotAnEnumVariantStructOrConst(name) => {
389 struct_span_err!(resolver.session,
392 "`{}` is not an enum variant, struct or const",
395 ResolutionError::UnresolvedEnumVariantStructOrConst(name) => {
396 struct_span_err!(resolver.session,
399 "unresolved enum variant, struct or const `{}`",
402 ResolutionError::NotAnAssociatedConst(name) => {
403 struct_span_err!(resolver.session,
406 "`{}` is not an associated const",
409 ResolutionError::UnresolvedAssociatedConst(name) => {
410 struct_span_err!(resolver.session,
413 "unresolved associated const `{}`",
416 ResolutionError::DoesNotNameAStruct(name) => {
417 struct_span_err!(resolver.session,
420 "`{}` does not name a structure",
423 ResolutionError::StructVariantUsedAsFunction(path_name) => {
424 struct_span_err!(resolver.session,
427 "`{}` is the name of a struct or struct variant, but this expression \
428 uses it like a function name",
431 ResolutionError::SelfNotAvailableInStaticMethod => {
432 struct_span_err!(resolver.session,
435 "`self` is not available in a static method. Maybe a `self` \
436 argument is missing?")
438 ResolutionError::UnresolvedName(path, msg, context) => {
439 let mut err = struct_span_err!(resolver.session,
442 "unresolved name `{}`{}",
447 UnresolvedNameContext::Other => { } // no help available
448 UnresolvedNameContext::PathIsMod(id) => {
449 let mut help_msg = String::new();
450 let parent_id = resolver.ast_map.get_parent_node(id);
451 if let Some(hir_map::Node::NodeExpr(e)) = resolver.ast_map.find(parent_id) {
453 ExprField(_, ident) => {
454 help_msg = format!("To reference an item from the \
455 `{module}` module, use \
456 `{module}::{ident}`",
460 ExprMethodCall(ident, _, _) => {
461 help_msg = format!("To call a function from the \
462 `{module}` module, use \
463 `{module}::{ident}(..)`",
468 help_msg = format!("No function corresponds to `{module}(..)`",
471 _ => { } // no help available
474 help_msg = format!("Module `{module}` cannot be the value of an expression",
478 if !help_msg.is_empty() {
479 err.fileline_help(span, &help_msg);
485 ResolutionError::UndeclaredLabel(name) => {
486 struct_span_err!(resolver.session,
489 "use of undeclared label `{}`",
492 ResolutionError::CannotUseRefBindingModeWith(descr) => {
493 struct_span_err!(resolver.session,
496 "cannot use `ref` binding mode with {}",
499 ResolutionError::DuplicateDefinition(namespace, name) => {
500 struct_span_err!(resolver.session,
503 "duplicate definition of {} `{}`",
507 ResolutionError::SelfImportsOnlyAllowedWithin => {
508 struct_span_err!(resolver.session,
512 "`self` imports are only allowed within a { } list")
514 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
515 struct_span_err!(resolver.session,
518 "`self` import can only appear once in the list")
520 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
521 struct_span_err!(resolver.session,
524 "`self` import can only appear in an import list with a \
527 ResolutionError::UnresolvedImport(name) => {
528 let msg = match name {
529 Some((n, p)) => format!("unresolved import `{}`{}", n, p),
530 None => "unresolved import".to_owned(),
532 struct_span_err!(resolver.session, span, E0432, "{}", msg)
534 ResolutionError::FailedToResolve(msg) => {
535 struct_span_err!(resolver.session, span, E0433, "failed to resolve. {}", msg)
537 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
538 struct_span_err!(resolver.session,
542 "can't capture dynamic environment in a fn item; use the || { ... } \
543 closure form instead")
545 ResolutionError::AttemptToUseNonConstantValueInConstant => {
546 struct_span_err!(resolver.session,
549 "attempt to use a non-constant value in a constant")
554 #[derive(Copy, Clone)]
557 binding_mode: BindingMode,
560 // Map from the name in a pattern to its binding mode.
561 type BindingMap = HashMap<Name, BindingInfo>;
563 #[derive(Copy, Clone, PartialEq)]
564 enum PatternBindingMode {
566 LocalIrrefutableMode,
567 ArgumentIrrefutableMode,
570 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
576 /// A NamespaceResult represents the result of resolving an import in
577 /// a particular namespace. The result is either definitely-resolved,
578 /// definitely- unresolved, or unknown.
580 enum NamespaceResult<'a> {
581 /// Means that resolve hasn't gathered enough information yet to determine
582 /// whether the name is bound in this namespace. (That is, it hasn't
583 /// resolved all `use` directives yet.)
585 /// Means that resolve has determined that the name is definitely
586 /// not bound in the namespace.
588 /// Means that resolve has determined that the name is bound in the Module
589 /// argument, and specified by the NameBinding argument.
590 BoundResult(Module<'a>, NameBinding<'a>),
593 impl<'a> NamespaceResult<'a> {
594 fn is_unknown(&self) -> bool {
596 UnknownResult => true,
600 fn is_unbound(&self) -> bool {
602 UnboundResult => true,
608 impl<'a, 'v, 'tcx> Visitor<'v> for Resolver<'a, 'tcx> {
609 fn visit_nested_item(&mut self, item: hir::ItemId) {
610 self.visit_item(self.ast_map.expect_item(item.id))
612 fn visit_item(&mut self, item: &Item) {
613 execute_callback!(hir_map::Node::NodeItem(item), self);
614 self.resolve_item(item);
616 fn visit_arm(&mut self, arm: &Arm) {
617 self.resolve_arm(arm);
619 fn visit_block(&mut self, block: &Block) {
620 execute_callback!(hir_map::Node::NodeBlock(block), self);
621 self.resolve_block(block);
623 fn visit_expr(&mut self, expr: &Expr) {
624 execute_callback!(hir_map::Node::NodeExpr(expr), self);
625 self.resolve_expr(expr);
627 fn visit_local(&mut self, local: &Local) {
628 execute_callback!(hir_map::Node::NodeLocal(&*local.pat), self);
629 self.resolve_local(local);
631 fn visit_ty(&mut self, ty: &Ty) {
632 self.resolve_type(ty);
634 fn visit_generics(&mut self, generics: &Generics) {
635 self.resolve_generics(generics);
637 fn visit_poly_trait_ref(&mut self, tref: &hir::PolyTraitRef, m: &hir::TraitBoundModifier) {
638 match self.resolve_trait_reference(tref.trait_ref.ref_id, &tref.trait_ref.path, 0) {
639 Ok(def) => self.record_def(tref.trait_ref.ref_id, def),
641 // error already reported
642 self.record_def(tref.trait_ref.ref_id, err_path_resolution())
645 intravisit::walk_poly_trait_ref(self, tref, m);
647 fn visit_variant(&mut self,
648 variant: &hir::Variant,
650 item_id: ast::NodeId) {
651 execute_callback!(hir_map::Node::NodeVariant(variant), self);
652 if let Some(ref dis_expr) = variant.node.disr_expr {
653 // resolve the discriminator expr as a constant
654 self.with_constant_rib(|this| {
655 this.visit_expr(dis_expr);
659 // `intravisit::walk_variant` without the discriminant expression.
660 self.visit_variant_data(&variant.node.data,
666 fn visit_foreign_item(&mut self, foreign_item: &hir::ForeignItem) {
667 execute_callback!(hir_map::Node::NodeForeignItem(foreign_item), self);
668 let type_parameters = match foreign_item.node {
669 ForeignItemFn(_, ref generics) => {
670 HasTypeParameters(generics, FnSpace, ItemRibKind)
672 ForeignItemStatic(..) => NoTypeParameters,
674 self.with_type_parameter_rib(type_parameters, |this| {
675 intravisit::walk_foreign_item(this, foreign_item);
678 fn visit_fn(&mut self,
679 function_kind: FnKind<'v>,
680 declaration: &'v FnDecl,
684 let rib_kind = match function_kind {
685 FnKind::ItemFn(_, generics, _, _, _, _) => {
686 self.visit_generics(generics);
689 FnKind::Method(_, sig, _) => {
690 self.visit_generics(&sig.generics);
691 self.visit_explicit_self(&sig.explicit_self);
694 FnKind::Closure => ClosureRibKind(node_id),
696 self.resolve_function(rib_kind, declaration, block);
700 type ErrorMessage = Option<(Span, String)>;
702 enum ResolveResult<T> {
703 Failed(ErrorMessage), // Failed to resolve the name, optional helpful error message.
704 Indeterminate, // Couldn't determine due to unresolved globs.
705 Success(T), // Successfully resolved the import.
708 impl<T> ResolveResult<T> {
709 fn success(&self) -> bool {
717 enum FallbackSuggestion {
722 StaticMethod(String),
726 #[derive(Copy, Clone)]
727 enum TypeParameters<'tcx, 'a> {
729 HasTypeParameters(// Type parameters.
732 // Identifies the things that these parameters
733 // were declared on (type, fn, etc)
736 // The kind of the rib used for type parameters.
740 // The rib kind controls the translation of local
741 // definitions (`Def::Local`) to upvars (`Def::Upvar`).
742 #[derive(Copy, Clone, Debug)]
744 // No translation needs to be applied.
747 // We passed through a closure scope at the given node ID.
748 // Translate upvars as appropriate.
749 ClosureRibKind(NodeId /* func id */),
751 // We passed through an impl or trait and are now in one of its
752 // methods. Allow references to ty params that impl or trait
753 // binds. Disallow any other upvars (including other ty params that are
757 // We passed through an item scope. Disallow upvars.
760 // We're in a constant item. Can't refer to dynamic stuff.
763 // We passed through an anonymous module.
764 AnonymousModuleRibKind(Module<'a>),
767 #[derive(Copy, Clone)]
768 enum UseLexicalScopeFlag {
773 enum ModulePrefixResult<'a> {
775 PrefixFound(Module<'a>, usize),
778 #[derive(Copy, Clone)]
779 enum AssocItemResolveResult {
780 /// Syntax such as `<T>::item`, which can't be resolved until type
783 /// We should have been able to resolve the associated item.
784 ResolveAttempt(Option<PathResolution>),
787 #[derive(Copy, Clone, PartialEq)]
788 enum NameSearchType {
789 /// We're doing a name search in order to resolve a `use` directive.
792 /// We're doing a name search in order to resolve a path type, a path
793 /// expression, or a path pattern.
797 #[derive(Copy, Clone)]
798 enum BareIdentifierPatternResolution {
799 FoundStructOrEnumVariant(Def, LastPrivate),
800 FoundConst(Def, LastPrivate, Name),
801 BareIdentifierPatternUnresolved,
807 bindings: HashMap<Name, DefLike>,
812 fn new(kind: RibKind<'a>) -> Rib<'a> {
814 bindings: HashMap::new(),
820 /// A definition along with the index of the rib it was found on
822 ribs: Option<(Namespace, usize)>,
827 fn from_def(def: Def) -> Self {
835 /// The link from a module up to its nearest parent node.
836 #[derive(Clone,Debug)]
837 enum ParentLink<'a> {
839 ModuleParentLink(Module<'a>, Name),
840 BlockParentLink(Module<'a>, NodeId),
843 /// One node in the tree of modules.
844 pub struct ModuleS<'a> {
845 parent_link: ParentLink<'a>,
846 def: Cell<Option<Def>>,
849 children: RefCell<HashMap<Name, NameBindings<'a>>>,
850 imports: RefCell<Vec<ImportDirective>>,
852 // The external module children of this node that were declared with
854 external_module_children: RefCell<HashMap<Name, Module<'a>>>,
856 // The anonymous children of this node. Anonymous children are pseudo-
857 // modules that are implicitly created around items contained within
860 // For example, if we have this:
868 // There will be an anonymous module created around `g` with the ID of the
869 // entry block for `f`.
870 anonymous_children: RefCell<NodeMap<Module<'a>>>,
872 // The status of resolving each import in this module.
873 import_resolutions: RefCell<HashMap<Name, ImportResolutionPerNamespace<'a>>>,
875 // The number of unresolved globs that this module exports.
876 glob_count: Cell<usize>,
878 // The number of unresolved pub imports (both regular and globs) in this module
879 pub_count: Cell<usize>,
881 // The number of unresolved pub glob imports in this module
882 pub_glob_count: Cell<usize>,
884 // The index of the import we're resolving.
885 resolved_import_count: Cell<usize>,
887 // Whether this module is populated. If not populated, any attempt to
888 // access the children must be preceded with a
889 // `populate_module_if_necessary` call.
890 populated: Cell<bool>,
893 pub type Module<'a> = &'a ModuleS<'a>;
895 impl<'a> ModuleS<'a> {
896 fn new(parent_link: ParentLink<'a>, def: Option<Def>, external: bool, is_public: bool) -> Self {
898 parent_link: parent_link,
900 is_public: is_public,
901 children: RefCell::new(HashMap::new()),
902 imports: RefCell::new(Vec::new()),
903 external_module_children: RefCell::new(HashMap::new()),
904 anonymous_children: RefCell::new(NodeMap()),
905 import_resolutions: RefCell::new(HashMap::new()),
906 glob_count: Cell::new(0),
907 pub_count: Cell::new(0),
908 pub_glob_count: Cell::new(0),
909 resolved_import_count: Cell::new(0),
910 populated: Cell::new(!external),
914 fn def_id(&self) -> Option<DefId> {
915 self.def.get().as_ref().map(Def::def_id)
918 fn is_normal(&self) -> bool {
919 match self.def.get() {
920 Some(Def::Mod(_)) | Some(Def::ForeignMod(_)) => true,
925 fn is_trait(&self) -> bool {
926 match self.def.get() {
927 Some(Def::Trait(_)) => true,
932 fn all_imports_resolved(&self) -> bool {
933 if self.imports.borrow_state() == ::std::cell::BorrowState::Writing {
934 // it is currently being resolved ! so nope
937 self.imports.borrow().len() == self.resolved_import_count.get()
941 pub fn inc_glob_count(&self) {
942 self.glob_count.set(self.glob_count.get() + 1);
944 pub fn dec_glob_count(&self) {
945 assert!(self.glob_count.get() > 0);
946 self.glob_count.set(self.glob_count.get() - 1);
948 pub fn inc_pub_count(&self) {
949 self.pub_count.set(self.pub_count.get() + 1);
951 pub fn dec_pub_count(&self) {
952 assert!(self.pub_count.get() > 0);
953 self.pub_count.set(self.pub_count.get() - 1);
955 pub fn inc_pub_glob_count(&self) {
956 self.pub_glob_count.set(self.pub_glob_count.get() + 1);
958 pub fn dec_pub_glob_count(&self) {
959 assert!(self.pub_glob_count.get() > 0);
960 self.pub_glob_count.set(self.pub_glob_count.get() - 1);
964 impl<'a> fmt::Debug for ModuleS<'a> {
965 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
979 flags DefModifiers: u8 {
980 // Enum variants are always considered `PUBLIC`, this is needed for `use Enum::Variant`
981 // or `use Enum::*` to work on private enums.
982 const PUBLIC = 1 << 0,
983 const IMPORTABLE = 1 << 1,
984 // Variants are considered `PUBLIC`, but some of them live in private enums.
985 // We need to track them to prohibit reexports like `pub use PrivEnum::Variant`.
986 const PRIVATE_VARIANT = 1 << 2,
990 // Records a possibly-private value, type, or module definition.
993 modifiers: DefModifiers, // see note in ImportResolutionPerNamespace about how to use this
994 def_or_module: DefOrModule<'a>,
999 enum DefOrModule<'a> {
1004 impl<'a> NsDef<'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 NsDef { modifiers: modifiers, def_or_module: DefOrModule::Module(module), span: span }
1015 fn create_from_def(def: Def, modifiers: DefModifiers, span: Option<Span>) -> Self {
1016 NsDef { modifiers: modifiers, def_or_module: DefOrModule::Def(def), span: span }
1019 fn module(&self) -> Option<Module<'a>> {
1020 match self.def_or_module {
1021 DefOrModule::Module(ref module) => Some(module),
1022 DefOrModule::Def(_) => None,
1026 fn def(&self) -> Option<Def> {
1027 match self.def_or_module {
1028 DefOrModule::Def(def) => Some(def),
1029 DefOrModule::Module(ref module) => module.def.get(),
1034 // Records at most one definition that a name in a namespace is bound to
1035 #[derive(Clone,Debug)]
1036 pub struct NameBinding<'a>(Rc<RefCell<Option<NsDef<'a>>>>);
1038 impl<'a> NameBinding<'a> {
1040 NameBinding(Rc::new(RefCell::new(None)))
1043 fn create_from_module(module: Module<'a>) -> Self {
1044 NameBinding(Rc::new(RefCell::new(Some(NsDef::create_from_module(module, None)))))
1047 fn set(&self, ns_def: NsDef<'a>) {
1048 *self.0.borrow_mut() = Some(ns_def);
1051 fn set_modifiers(&self, modifiers: DefModifiers) {
1052 if let Some(ref mut ns_def) = *self.0.borrow_mut() {
1053 ns_def.modifiers = modifiers
1057 fn borrow(&self) -> ::std::cell::Ref<Option<NsDef<'a>>> {
1061 // Lifted versions of the NsDef methods and fields
1062 fn def(&self) -> Option<Def> {
1063 self.borrow().as_ref().and_then(NsDef::def)
1065 fn module(&self) -> Option<Module<'a>> {
1066 self.borrow().as_ref().and_then(NsDef::module)
1068 fn span(&self) -> Option<Span> {
1069 self.borrow().as_ref().and_then(|def| def.span)
1071 fn modifiers(&self) -> Option<DefModifiers> {
1072 self.borrow().as_ref().and_then(|def| Some(def.modifiers))
1075 fn defined(&self) -> bool {
1076 self.borrow().is_some()
1079 fn defined_with(&self, modifiers: DefModifiers) -> bool {
1080 self.modifiers().map(|m| m.contains(modifiers)).unwrap_or(false)
1083 fn is_public(&self) -> bool {
1084 self.defined_with(DefModifiers::PUBLIC)
1087 fn def_and_lp(&self) -> (Def, LastPrivate) {
1088 let def = self.def().unwrap();
1089 (def, LastMod(if self.is_public() { AllPublic } else { DependsOn(def.def_id()) }))
1093 // Records the definitions (at most one for each namespace) that a name is
1095 #[derive(Clone,Debug)]
1096 pub struct NameBindings<'a> {
1097 type_ns: NameBinding<'a>, // < Meaning in type namespace.
1098 value_ns: NameBinding<'a>, // < Meaning in value namespace.
1101 impl<'a> ::std::ops::Index<Namespace> for NameBindings<'a> {
1102 type Output = NameBinding<'a>;
1103 fn index(&self, namespace: Namespace) -> &NameBinding<'a> {
1104 match namespace { TypeNS => &self.type_ns, ValueNS => &self.value_ns }
1108 impl<'a> NameBindings<'a> {
1111 type_ns: NameBinding::new(),
1112 value_ns: NameBinding::new(),
1116 /// Creates a new module in this set of name bindings.
1117 fn define_module(&self, module: Module<'a>, sp: Span) {
1118 self.type_ns.set(NsDef::create_from_module(module, Some(sp)));
1121 /// Records a type definition.
1122 fn define_type(&self, def: Def, sp: Span, modifiers: DefModifiers) {
1123 debug!("defining type for def {:?} with modifiers {:?}", def, modifiers);
1124 self.type_ns.set(NsDef::create_from_def(def, modifiers, Some(sp)));
1127 /// Records a value definition.
1128 fn define_value(&self, def: Def, sp: Span, modifiers: DefModifiers) {
1129 debug!("defining value for def {:?} with modifiers {:?}", def, modifiers);
1130 self.value_ns.set(NsDef::create_from_def(def, modifiers, Some(sp)));
1134 /// Interns the names of the primitive types.
1135 struct PrimitiveTypeTable {
1136 primitive_types: HashMap<Name, PrimTy>,
1139 impl PrimitiveTypeTable {
1140 fn new() -> PrimitiveTypeTable {
1141 let mut table = PrimitiveTypeTable { primitive_types: HashMap::new() };
1143 table.intern("bool", TyBool);
1144 table.intern("char", TyChar);
1145 table.intern("f32", TyFloat(TyF32));
1146 table.intern("f64", TyFloat(TyF64));
1147 table.intern("isize", TyInt(TyIs));
1148 table.intern("i8", TyInt(TyI8));
1149 table.intern("i16", TyInt(TyI16));
1150 table.intern("i32", TyInt(TyI32));
1151 table.intern("i64", TyInt(TyI64));
1152 table.intern("str", TyStr);
1153 table.intern("usize", TyUint(TyUs));
1154 table.intern("u8", TyUint(TyU8));
1155 table.intern("u16", TyUint(TyU16));
1156 table.intern("u32", TyUint(TyU32));
1157 table.intern("u64", TyUint(TyU64));
1162 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1163 self.primitive_types.insert(token::intern(string), primitive_type);
1167 /// The main resolver class.
1168 pub struct Resolver<'a, 'tcx: 'a> {
1169 session: &'a Session,
1171 ast_map: &'a hir_map::Map<'tcx>,
1173 graph_root: Module<'a>,
1175 trait_item_map: FnvHashMap<(Name, DefId), DefId>,
1177 structs: FnvHashMap<DefId, Vec<Name>>,
1179 // The number of imports that are currently unresolved.
1180 unresolved_imports: usize,
1182 // The module that represents the current item scope.
1183 current_module: Module<'a>,
1185 // The current set of local scopes, for values.
1186 // FIXME #4948: Reuse ribs to avoid allocation.
1187 value_ribs: Vec<Rib<'a>>,
1189 // The current set of local scopes, for types.
1190 type_ribs: Vec<Rib<'a>>,
1192 // The current set of local scopes, for labels.
1193 label_ribs: Vec<Rib<'a>>,
1195 // The trait that the current context can refer to.
1196 current_trait_ref: Option<(DefId, TraitRef)>,
1198 // The current self type if inside an impl (used for better errors).
1199 current_self_type: Option<Ty>,
1201 // The idents for the primitive types.
1202 primitive_type_table: PrimitiveTypeTable,
1204 def_map: RefCell<DefMap>,
1205 freevars: FreevarMap,
1206 freevars_seen: NodeMap<NodeMap<usize>>,
1207 export_map: ExportMap,
1208 trait_map: TraitMap,
1209 external_exports: ExternalExports,
1211 // Whether or not to print error messages. Can be set to true
1212 // when getting additional info for error message suggestions,
1213 // so as to avoid printing duplicate errors
1216 make_glob_map: bool,
1217 // Maps imports to the names of items actually imported (this actually maps
1218 // all imports, but only glob imports are actually interesting).
1221 used_imports: HashSet<(NodeId, Namespace)>,
1222 used_crates: HashSet<CrateNum>,
1224 // Callback function for intercepting walks
1225 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>,
1226 // The intention is that the callback modifies this flag.
1227 // Once set, the resolver falls out of the walk, preserving the ribs.
1230 arenas: &'a ResolverArenas<'a>,
1233 pub struct ResolverArenas<'a> {
1234 modules: arena::TypedArena<ModuleS<'a>>,
1237 #[derive(PartialEq)]
1238 enum FallbackChecks {
1240 OnlyTraitAndStatics,
1243 impl<'a, 'tcx> Resolver<'a, 'tcx> {
1244 fn new(session: &'a Session,
1245 ast_map: &'a hir_map::Map<'tcx>,
1246 make_glob_map: MakeGlobMap,
1247 arenas: &'a ResolverArenas<'a>)
1248 -> Resolver<'a, 'tcx> {
1249 let root_def_id = ast_map.local_def_id(CRATE_NODE_ID);
1250 let graph_root = ModuleS::new(NoParentLink, Some(Def::Mod(root_def_id)), false, true);
1251 let graph_root = arenas.modules.alloc(graph_root);
1258 // The outermost module has def ID 0; this is not reflected in the
1260 graph_root: graph_root,
1262 trait_item_map: FnvHashMap(),
1263 structs: FnvHashMap(),
1265 unresolved_imports: 0,
1267 current_module: graph_root,
1268 value_ribs: Vec::new(),
1269 type_ribs: Vec::new(),
1270 label_ribs: Vec::new(),
1272 current_trait_ref: None,
1273 current_self_type: None,
1275 primitive_type_table: PrimitiveTypeTable::new(),
1277 def_map: RefCell::new(NodeMap()),
1278 freevars: NodeMap(),
1279 freevars_seen: NodeMap(),
1280 export_map: NodeMap(),
1281 trait_map: NodeMap(),
1282 used_imports: HashSet::new(),
1283 used_crates: HashSet::new(),
1284 external_exports: DefIdSet(),
1287 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1288 glob_map: HashMap::new(),
1297 fn arenas() -> ResolverArenas<'a> {
1299 modules: arena::TypedArena::new(),
1303 fn new_module(&self,
1304 parent_link: ParentLink<'a>,
1307 is_public: bool) -> Module<'a> {
1308 self.arenas.modules.alloc(ModuleS::new(parent_link, def, external, is_public))
1311 fn get_ribs<'b>(&'b mut self, ns: Namespace) -> &'b mut Vec<Rib<'a>> {
1312 match ns { ValueNS => &mut self.value_ribs, TypeNS => &mut self.type_ribs }
1316 fn record_import_use(&mut self, import_id: NodeId, name: Name) {
1317 if !self.make_glob_map {
1320 if self.glob_map.contains_key(&import_id) {
1321 self.glob_map.get_mut(&import_id).unwrap().insert(name);
1325 let mut new_set = HashSet::new();
1326 new_set.insert(name);
1327 self.glob_map.insert(import_id, new_set);
1330 fn get_trait_name(&self, did: DefId) -> Name {
1331 if let Some(node_id) = self.ast_map.as_local_node_id(did) {
1332 self.ast_map.expect_item(node_id).name
1334 self.session.cstore.item_name(did)
1338 /// Check that an external crate doesn't collide with items or other external crates.
1339 fn check_for_conflicts_for_external_crate(&self, module: Module<'a>, name: Name, span: Span) {
1340 if module.external_module_children.borrow().contains_key(&name) {
1341 span_err!(self.session,
1344 "an external crate named `{}` has already been imported into this module",
1347 match module.children.borrow().get(&name) {
1348 Some(name_bindings) if name_bindings.type_ns.defined() => {
1350 name_bindings.type_ns.span().unwrap_or(codemap::DUMMY_SP),
1351 ResolutionError::NameConflictsWithExternCrate(name));
1357 /// Checks that the names of items don't collide with external crates.
1358 fn check_for_conflicts_between_external_crates_and_items(&self,
1362 if module.external_module_children.borrow().contains_key(&name) {
1363 resolve_error(self, span, ResolutionError::NameConflictsWithExternCrate(name));
1367 /// Resolves the given module path from the given root `module_`.
1368 fn resolve_module_path_from_root(&mut self,
1369 module_: Module<'a>,
1370 module_path: &[Name],
1373 name_search_type: NameSearchType,
1375 -> ResolveResult<(Module<'a>, LastPrivate)> {
1376 fn search_parent_externals<'a>(needle: Name, module: Module<'a>)
1377 -> Option<Module<'a>> {
1378 match module.external_module_children.borrow().get(&needle) {
1379 Some(_) => Some(module),
1380 None => match module.parent_link {
1381 ModuleParentLink(ref parent, _) => {
1382 search_parent_externals(needle, parent)
1389 let mut search_module = module_;
1390 let mut index = index;
1391 let module_path_len = module_path.len();
1392 let mut closest_private = lp;
1394 // Resolve the module part of the path. This does not involve looking
1395 // upward though scope chains; we simply resolve names directly in
1396 // modules as we go.
1397 while index < module_path_len {
1398 let name = module_path[index];
1399 match self.resolve_name_in_module(search_module,
1405 let segment_name = name.as_str();
1406 let module_name = module_to_string(search_module);
1407 let mut span = span;
1408 let msg = if "???" == &module_name[..] {
1409 span.hi = span.lo + Pos::from_usize(segment_name.len());
1411 match search_parent_externals(name, &self.current_module) {
1413 let path_str = names_to_string(module_path);
1414 let target_mod_str = module_to_string(&*module);
1415 let current_mod_str = module_to_string(&*self.current_module);
1417 let prefix = if target_mod_str == current_mod_str {
1418 "self::".to_string()
1420 format!("{}::", target_mod_str)
1423 format!("Did you mean `{}{}`?", prefix, path_str)
1425 None => format!("Maybe a missing `extern crate {}`?", segment_name),
1428 format!("Could not find `{}` in `{}`", segment_name, module_name)
1431 return Failed(Some((span, msg)));
1433 Failed(err) => return Failed(err),
1435 debug!("(resolving module path for import) module resolution is \
1438 return Indeterminate;
1440 Success((target, used_proxy)) => {
1441 // Check to see whether there are type bindings, and, if
1442 // so, whether there is a module within.
1443 if let Some(module_def) = target.binding.module() {
1444 // track extern crates for unused_extern_crate lint
1445 if let Some(did) = module_def.def_id() {
1446 self.used_crates.insert(did.krate);
1449 search_module = module_def;
1451 // Keep track of the closest private module used
1452 // when resolving this import chain.
1453 if !used_proxy && !search_module.is_public {
1454 if let Some(did) = search_module.def_id() {
1455 closest_private = LastMod(DependsOn(did));
1459 let msg = format!("Not a module `{}`", name);
1460 return Failed(Some((span, msg)));
1468 return Success((search_module, closest_private));
1471 /// Attempts to resolve the module part of an import directive or path
1472 /// rooted at the given module.
1474 /// On success, returns the resolved module, and the closest *private*
1475 /// module found to the destination when resolving this path.
1476 fn resolve_module_path(&mut self,
1477 module_: Module<'a>,
1478 module_path: &[Name],
1479 use_lexical_scope: UseLexicalScopeFlag,
1481 name_search_type: NameSearchType)
1482 -> ResolveResult<(Module<'a>, LastPrivate)> {
1483 let module_path_len = module_path.len();
1484 assert!(module_path_len > 0);
1486 debug!("(resolving module path for import) processing `{}` rooted at `{}`",
1487 names_to_string(module_path),
1488 module_to_string(&*module_));
1490 // Resolve the module prefix, if any.
1491 let module_prefix_result = self.resolve_module_prefix(module_, module_path);
1496 match module_prefix_result {
1498 let mpath = names_to_string(module_path);
1499 let mpath = &mpath[..];
1500 match mpath.rfind(':') {
1502 let msg = format!("Could not find `{}` in `{}`",
1503 // idx +- 1 to account for the
1504 // colons on either side
1507 return Failed(Some((span, msg)));
1510 return Failed(None);
1514 Failed(err) => return Failed(err),
1516 debug!("(resolving module path for import) indeterminate; bailing");
1517 return Indeterminate;
1519 Success(NoPrefixFound) => {
1520 // There was no prefix, so we're considering the first element
1521 // of the path. How we handle this depends on whether we were
1522 // instructed to use lexical scope or not.
1523 match use_lexical_scope {
1524 DontUseLexicalScope => {
1525 // This is a crate-relative path. We will start the
1526 // resolution process at index zero.
1527 search_module = self.graph_root;
1529 last_private = LastMod(AllPublic);
1531 UseLexicalScope => {
1532 // This is not a crate-relative path. We resolve the
1533 // first component of the path in the current lexical
1534 // scope and then proceed to resolve below that.
1535 match self.resolve_module_in_lexical_scope(module_, module_path[0]) {
1536 Failed(err) => return Failed(err),
1538 debug!("(resolving module path for import) indeterminate; bailing");
1539 return Indeterminate;
1541 Success(containing_module) => {
1542 search_module = containing_module;
1544 last_private = LastMod(AllPublic);
1550 Success(PrefixFound(ref containing_module, index)) => {
1551 search_module = containing_module;
1552 start_index = index;
1553 last_private = LastMod(DependsOn(containing_module.def_id()
1558 self.resolve_module_path_from_root(search_module,
1566 /// Invariant: This must only be called during main resolution, not during
1567 /// import resolution.
1568 fn resolve_item_in_lexical_scope(&mut self,
1569 module_: Module<'a>,
1571 namespace: Namespace,
1573 -> ResolveResult<(Target<'a>, bool)> {
1574 debug!("(resolving item in lexical scope) resolving `{}` in namespace {:?} in `{}`",
1577 module_to_string(&*module_));
1579 // The current module node is handled specially. First, check for
1580 // its immediate children.
1581 build_reduced_graph::populate_module_if_necessary(self, &module_);
1583 match module_.children.borrow().get(&name) {
1584 Some(name_bindings) if name_bindings[namespace].defined() => {
1585 debug!("top name bindings succeeded");
1586 return Success((Target::new(module_,
1587 name_bindings[namespace].clone(),
1592 // Not found; continue.
1596 // Now check for its import directives. We don't have to have resolved
1597 // all its imports in the usual way; this is because chains of
1598 // adjacent import statements are processed as though they mutated the
1600 if let Some(import_resolution) = module_.import_resolutions.borrow().get(&name) {
1601 match import_resolution[namespace].target.clone() {
1603 // Not found; continue.
1604 debug!("(resolving item in lexical scope) found import resolution, but not \
1609 debug!("(resolving item in lexical scope) using import resolution");
1610 // track used imports and extern crates as well
1611 let id = import_resolution[namespace].id;
1613 self.used_imports.insert((id, namespace));
1614 self.record_import_use(id, name);
1615 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id() {
1616 self.used_crates.insert(kid);
1619 return Success((target, false));
1624 // Search for external modules.
1625 if namespace == TypeNS {
1626 let children = module_.external_module_children.borrow();
1627 if let Some(module) = children.get(&name) {
1628 let name_binding = NameBinding::create_from_module(module);
1629 debug!("lower name bindings succeeded");
1630 return Success((Target::new(module_, name_binding, Shadowable::Never),
1635 // Finally, proceed up the scope chain looking for parent modules.
1636 let mut search_module = module_;
1638 // Go to the next parent.
1639 match search_module.parent_link {
1641 // No more parents. This module was unresolved.
1642 debug!("(resolving item in lexical scope) unresolved module");
1643 return Failed(None);
1645 ModuleParentLink(parent_module_node, _) => {
1646 if search_module.is_normal() {
1647 // We stop the search here.
1648 debug!("(resolving item in lexical scope) unresolved module: not \
1649 searching through module parents");
1650 return Failed(None);
1652 search_module = parent_module_node;
1655 BlockParentLink(parent_module_node, _) => {
1656 search_module = parent_module_node;
1660 // Resolve the name in the parent module.
1661 match self.resolve_name_in_module(search_module,
1666 Failed(Some((span, msg))) => {
1667 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
1669 Failed(None) => (), // Continue up the search chain.
1671 // We couldn't see through the higher scope because of an
1672 // unresolved import higher up. Bail.
1674 debug!("(resolving item in lexical scope) indeterminate higher scope; bailing");
1675 return Indeterminate;
1677 Success((target, used_reexport)) => {
1678 // We found the module.
1679 debug!("(resolving item in lexical scope) found name in module, done");
1680 return Success((target, used_reexport));
1686 /// Resolves a module name in the current lexical scope.
1687 fn resolve_module_in_lexical_scope(&mut self,
1688 module_: Module<'a>,
1690 -> ResolveResult<Module<'a>> {
1691 // If this module is an anonymous module, resolve the item in the
1692 // lexical scope. Otherwise, resolve the item from the crate root.
1693 let resolve_result = self.resolve_item_in_lexical_scope(module_, name, TypeNS, true);
1694 match resolve_result {
1695 Success((target, _)) => {
1696 if let Some(module_def) = target.binding.module() {
1697 return Success(module_def)
1699 debug!("!!! (resolving module in lexical scope) module \
1700 wasn't actually a module!");
1701 return Failed(None);
1705 debug!("(resolving module in lexical scope) indeterminate; bailing");
1706 return Indeterminate;
1709 debug!("(resolving module in lexical scope) failed to resolve");
1715 /// Returns the nearest normal module parent of the given module.
1716 fn get_nearest_normal_module_parent(&mut self, module_: Module<'a>) -> Option<Module<'a>> {
1717 let mut module_ = module_;
1719 match module_.parent_link {
1720 NoParentLink => return None,
1721 ModuleParentLink(new_module, _) |
1722 BlockParentLink(new_module, _) => {
1723 let new_module = new_module;
1724 if new_module.is_normal() {
1725 return Some(new_module);
1727 module_ = new_module;
1733 /// Returns the nearest normal module parent of the given module, or the
1734 /// module itself if it is a normal module.
1735 fn get_nearest_normal_module_parent_or_self(&mut self, module_: Module<'a>) -> Module<'a> {
1736 if module_.is_normal() {
1739 match self.get_nearest_normal_module_parent(module_) {
1741 Some(new_module) => new_module,
1745 /// Resolves a "module prefix". A module prefix is one or both of (a) `self::`;
1746 /// (b) some chain of `super::`.
1747 /// grammar: (SELF MOD_SEP ) ? (SUPER MOD_SEP) *
1748 fn resolve_module_prefix(&mut self,
1749 module_: Module<'a>,
1750 module_path: &[Name])
1751 -> ResolveResult<ModulePrefixResult<'a>> {
1752 // Start at the current module if we see `self` or `super`, or at the
1753 // top of the crate otherwise.
1754 let mut i = match &*module_path[0].as_str() {
1757 _ => return Success(NoPrefixFound),
1759 let mut containing_module = self.get_nearest_normal_module_parent_or_self(module_);
1761 // Now loop through all the `super`s we find.
1762 while i < module_path.len() && "super" == module_path[i].as_str() {
1763 debug!("(resolving module prefix) resolving `super` at {}",
1764 module_to_string(&*containing_module));
1765 match self.get_nearest_normal_module_parent(containing_module) {
1766 None => return Failed(None),
1767 Some(new_module) => {
1768 containing_module = new_module;
1774 debug!("(resolving module prefix) finished resolving prefix at {}",
1775 module_to_string(&*containing_module));
1777 return Success(PrefixFound(containing_module, i));
1780 /// Attempts to resolve the supplied name in the given module for the
1781 /// given namespace. If successful, returns the target corresponding to
1784 /// The boolean returned on success is an indicator of whether this lookup
1785 /// passed through a public re-export proxy.
1786 fn resolve_name_in_module(&mut self,
1787 module_: Module<'a>,
1789 namespace: Namespace,
1790 name_search_type: NameSearchType,
1791 allow_private_imports: bool)
1792 -> ResolveResult<(Target<'a>, bool)> {
1793 debug!("(resolving name in module) resolving `{}` in `{}`",
1795 module_to_string(&*module_));
1797 // First, check the direct children of the module.
1798 build_reduced_graph::populate_module_if_necessary(self, &module_);
1800 let children = module_.children.borrow();
1801 match children.get(&name) {
1802 Some(name_bindings) if name_bindings[namespace].defined() => {
1803 debug!("(resolving name in module) found node as child");
1804 return Success((Target::new(module_,
1805 name_bindings[namespace].clone(),
1814 // Check the list of resolved imports.
1815 let children = module_.import_resolutions.borrow();
1816 match children.get(&name) {
1817 Some(import_resolution) if allow_private_imports ||
1818 import_resolution[namespace].is_public => {
1820 if import_resolution[namespace].is_public &&
1821 import_resolution.outstanding_references != 0 {
1822 debug!("(resolving name in module) import unresolved; bailing out");
1823 return Indeterminate;
1825 match import_resolution[namespace].target.clone() {
1827 debug!("(resolving name in module) name found, but not in namespace {:?}",
1831 debug!("(resolving name in module) resolved to import");
1832 // track used imports and extern crates as well
1833 let id = import_resolution[namespace].id;
1834 self.used_imports.insert((id, namespace));
1835 self.record_import_use(id, name);
1836 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id() {
1837 self.used_crates.insert(kid);
1839 return Success((target, true));
1843 Some(..) | None => {} // Continue.
1846 // Finally, search through external children.
1847 if namespace == TypeNS {
1848 let children = module_.external_module_children.borrow();
1849 if let Some(module) = children.get(&name) {
1850 let name_binding = NameBinding::create_from_module(module);
1851 return Success((Target::new(module_, name_binding, Shadowable::Never),
1856 // We're out of luck.
1857 debug!("(resolving name in module) failed to resolve `{}`", name);
1858 return Failed(None);
1861 fn report_unresolved_imports(&mut self, module_: Module<'a>) {
1862 let index = module_.resolved_import_count.get();
1863 let imports = module_.imports.borrow();
1864 let import_count = imports.len();
1865 if index != import_count {
1867 (*imports)[index].span,
1868 ResolutionError::UnresolvedImport(None));
1871 // Descend into children and anonymous children.
1872 build_reduced_graph::populate_module_if_necessary(self, &module_);
1874 for (_, child_node) in module_.children.borrow().iter() {
1875 match child_node.type_ns.module() {
1879 Some(child_module) => {
1880 self.report_unresolved_imports(child_module);
1885 for (_, module_) in module_.anonymous_children.borrow().iter() {
1886 self.report_unresolved_imports(module_);
1892 // We maintain a list of value ribs and type ribs.
1894 // Simultaneously, we keep track of the current position in the module
1895 // graph in the `current_module` pointer. When we go to resolve a name in
1896 // the value or type namespaces, we first look through all the ribs and
1897 // then query the module graph. When we resolve a name in the module
1898 // namespace, we can skip all the ribs (since nested modules are not
1899 // allowed within blocks in Rust) and jump straight to the current module
1902 // Named implementations are handled separately. When we find a method
1903 // call, we consult the module node to find all of the implementations in
1904 // scope. This information is lazily cached in the module node. We then
1905 // generate a fake "implementation scope" containing all the
1906 // implementations thus found, for compatibility with old resolve pass.
1908 fn with_scope<F>(&mut self, name: Option<Name>, f: F)
1909 where F: FnOnce(&mut Resolver)
1911 let orig_module = self.current_module;
1913 // Move down in the graph.
1919 build_reduced_graph::populate_module_if_necessary(self, &orig_module);
1921 match orig_module.children.borrow().get(&name) {
1923 debug!("!!! (with scope) didn't find `{}` in `{}`",
1925 module_to_string(&*orig_module));
1927 Some(name_bindings) => {
1928 match name_bindings.type_ns.module() {
1930 debug!("!!! (with scope) didn't find module for `{}` in `{}`",
1932 module_to_string(&*orig_module));
1935 self.current_module = module_;
1945 self.current_module = orig_module;
1948 /// Searches the current set of local scopes for labels.
1949 /// Stops after meeting a closure.
1950 fn search_label(&self, name: Name) -> Option<DefLike> {
1951 for rib in self.label_ribs.iter().rev() {
1957 // Do not resolve labels across function boundary
1961 let result = rib.bindings.get(&name).cloned();
1962 if result.is_some() {
1969 fn resolve_crate(&mut self, krate: &hir::Crate) {
1970 debug!("(resolving crate) starting");
1972 intravisit::walk_crate(self, krate);
1975 fn check_if_primitive_type_name(&self, name: Name, span: Span) {
1976 if let Some(_) = self.primitive_type_table.primitive_types.get(&name) {
1977 span_err!(self.session,
1980 "user-defined types or type parameters cannot shadow the primitive types");
1984 fn resolve_item(&mut self, item: &Item) {
1985 let name = item.name;
1987 debug!("(resolving item) resolving {}", name);
1990 ItemEnum(_, ref generics) |
1991 ItemTy(_, ref generics) |
1992 ItemStruct(_, ref generics) => {
1993 self.check_if_primitive_type_name(name, item.span);
1995 self.with_type_parameter_rib(HasTypeParameters(generics, TypeSpace, ItemRibKind),
1996 |this| intravisit::walk_item(this, item));
1998 ItemFn(_, _, _, _, ref generics, _) => {
1999 self.with_type_parameter_rib(HasTypeParameters(generics, FnSpace, ItemRibKind),
2000 |this| intravisit::walk_item(this, item));
2003 ItemDefaultImpl(_, ref trait_ref) => {
2004 self.with_optional_trait_ref(Some(trait_ref), |_, _| {});
2006 ItemImpl(_, _, ref generics, ref opt_trait_ref, ref self_type, ref impl_items) => {
2007 self.resolve_implementation(generics,
2014 ItemTrait(_, ref generics, ref bounds, ref trait_items) => {
2015 self.check_if_primitive_type_name(name, item.span);
2017 // Create a new rib for the trait-wide type parameters.
2018 self.with_type_parameter_rib(HasTypeParameters(generics,
2022 let local_def_id = this.ast_map.local_def_id(item.id);
2023 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2024 this.visit_generics(generics);
2025 walk_list!(this, visit_ty_param_bound, bounds);
2027 for trait_item in trait_items {
2028 match trait_item.node {
2029 hir::ConstTraitItem(_, ref default) => {
2030 // Only impose the restrictions of
2031 // ConstRibKind if there's an actual constant
2032 // expression in a provided default.
2033 if default.is_some() {
2034 this.with_constant_rib(|this| {
2035 intravisit::walk_trait_item(this, trait_item)
2038 intravisit::walk_trait_item(this, trait_item)
2041 hir::MethodTraitItem(ref sig, _) => {
2042 let type_parameters =
2043 HasTypeParameters(&sig.generics,
2046 this.with_type_parameter_rib(type_parameters, |this| {
2047 intravisit::walk_trait_item(this, trait_item)
2050 hir::TypeTraitItem(..) => {
2051 this.check_if_primitive_type_name(trait_item.name,
2053 this.with_type_parameter_rib(NoTypeParameters, |this| {
2054 intravisit::walk_trait_item(this, trait_item)
2063 ItemMod(_) | ItemForeignMod(_) => {
2064 self.with_scope(Some(name), |this| {
2065 intravisit::walk_item(this, item);
2069 ItemConst(..) | ItemStatic(..) => {
2070 self.with_constant_rib(|this| {
2071 intravisit::walk_item(this, item);
2075 ItemUse(ref view_path) => {
2076 // check for imports shadowing primitive types
2077 let check_rename = |this: &Self, id, name| {
2078 match this.def_map.borrow().get(&id).map(|d| d.full_def()) {
2079 Some(Def::Enum(..)) | Some(Def::TyAlias(..)) | Some(Def::Struct(..)) |
2080 Some(Def::Trait(..)) | None => {
2081 this.check_if_primitive_type_name(name, item.span);
2087 match view_path.node {
2088 hir::ViewPathSimple(name, _) => {
2089 check_rename(self, item.id, name);
2091 hir::ViewPathList(ref prefix, ref items) => {
2093 if let Some(name) = item.node.rename() {
2094 check_rename(self, item.node.id(), name);
2098 // Resolve prefix of an import with empty braces (issue #28388)
2099 if items.is_empty() && !prefix.segments.is_empty() {
2100 match self.resolve_crate_relative_path(prefix.span,
2104 self.record_def(item.id, PathResolution::new(def, lp, 0)),
2108 ResolutionError::FailedToResolve(
2109 &path_names_to_string(prefix, 0)));
2110 self.record_def(item.id, err_path_resolution());
2119 ItemExternCrate(_) => {
2120 // do nothing, these are just around to be encoded
2125 fn with_type_parameter_rib<'b, F>(&'b mut self, type_parameters: TypeParameters<'a, 'b>, f: F)
2126 where F: FnOnce(&mut Resolver)
2128 match type_parameters {
2129 HasTypeParameters(generics, space, rib_kind) => {
2130 let mut function_type_rib = Rib::new(rib_kind);
2131 let mut seen_bindings = HashSet::new();
2132 for (index, type_parameter) in generics.ty_params.iter().enumerate() {
2133 let name = type_parameter.name;
2134 debug!("with_type_parameter_rib: {}", type_parameter.id);
2136 if seen_bindings.contains(&name) {
2138 type_parameter.span,
2139 ResolutionError::NameAlreadyUsedInTypeParameterList(name));
2141 seen_bindings.insert(name);
2143 // plain insert (no renaming)
2144 function_type_rib.bindings
2146 DlDef(Def::TyParam(space,
2149 .local_def_id(type_parameter.id),
2152 self.type_ribs.push(function_type_rib);
2155 NoTypeParameters => {
2162 match type_parameters {
2163 HasTypeParameters(..) => {
2165 self.type_ribs.pop();
2168 NoTypeParameters => {}
2172 fn with_label_rib<F>(&mut self, f: F)
2173 where F: FnOnce(&mut Resolver)
2175 self.label_ribs.push(Rib::new(NormalRibKind));
2178 self.label_ribs.pop();
2182 fn with_constant_rib<F>(&mut self, f: F)
2183 where F: FnOnce(&mut Resolver)
2185 self.value_ribs.push(Rib::new(ConstantItemRibKind));
2186 self.type_ribs.push(Rib::new(ConstantItemRibKind));
2189 self.type_ribs.pop();
2190 self.value_ribs.pop();
2194 fn resolve_function(&mut self, rib_kind: RibKind<'a>, declaration: &FnDecl, block: &Block) {
2195 // Create a value rib for the function.
2196 self.value_ribs.push(Rib::new(rib_kind));
2198 // Create a label rib for the function.
2199 self.label_ribs.push(Rib::new(rib_kind));
2201 // Add each argument to the rib.
2202 let mut bindings_list = HashMap::new();
2203 for argument in &declaration.inputs {
2204 self.resolve_pattern(&*argument.pat, ArgumentIrrefutableMode, &mut bindings_list);
2206 self.visit_ty(&*argument.ty);
2208 debug!("(resolving function) recorded argument");
2210 intravisit::walk_fn_ret_ty(self, &declaration.output);
2212 // Resolve the function body.
2213 self.visit_block(block);
2215 debug!("(resolving function) leaving function");
2218 self.label_ribs.pop();
2219 self.value_ribs.pop();
2223 fn resolve_trait_reference(&mut self,
2227 -> Result<PathResolution, ()> {
2228 if let Some(path_res) = self.resolve_path(id, trait_path, path_depth, TypeNS, true) {
2229 if let Def::Trait(_) = path_res.base_def {
2230 debug!("(resolving trait) found trait def: {:?}", path_res);
2234 resolve_struct_error(self,
2236 ResolutionError::IsNotATrait(&*path_names_to_string(trait_path,
2239 // If it's a typedef, give a note
2240 if let Def::TyAlias(..) = path_res.base_def {
2241 err.span_note(trait_path.span,
2242 "`type` aliases cannot be used for traits");
2250 ResolutionError::UndeclaredTraitName(&*path_names_to_string(trait_path,
2256 fn resolve_generics(&mut self, generics: &Generics) {
2257 for type_parameter in generics.ty_params.iter() {
2258 self.check_if_primitive_type_name(type_parameter.name, type_parameter.span);
2260 for predicate in &generics.where_clause.predicates {
2262 &hir::WherePredicate::BoundPredicate(_) |
2263 &hir::WherePredicate::RegionPredicate(_) => {}
2264 &hir::WherePredicate::EqPredicate(ref eq_pred) => {
2265 let path_res = self.resolve_path(eq_pred.id, &eq_pred.path, 0, TypeNS, true);
2266 if let Some(PathResolution { base_def: Def::TyParam(..), .. }) = path_res {
2267 self.record_def(eq_pred.id, path_res.unwrap());
2271 ResolutionError::UndeclaredAssociatedType);
2272 self.record_def(eq_pred.id, err_path_resolution());
2277 intravisit::walk_generics(self, generics);
2280 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2281 where F: FnOnce(&mut Resolver) -> T
2283 // Handle nested impls (inside fn bodies)
2284 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2285 let result = f(self);
2286 self.current_self_type = previous_value;
2290 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
2291 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2293 let mut new_val = None;
2294 let mut new_id = None;
2295 if let Some(trait_ref) = opt_trait_ref {
2296 if let Ok(path_res) = self.resolve_trait_reference(trait_ref.ref_id,
2299 assert!(path_res.depth == 0);
2300 self.record_def(trait_ref.ref_id, path_res);
2301 new_val = Some((path_res.base_def.def_id(), trait_ref.clone()));
2302 new_id = Some(path_res.base_def.def_id());
2304 self.record_def(trait_ref.ref_id, err_path_resolution());
2306 intravisit::walk_trait_ref(self, trait_ref);
2308 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2309 let result = f(self, new_id);
2310 self.current_trait_ref = original_trait_ref;
2314 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2315 where F: FnOnce(&mut Resolver)
2317 let mut self_type_rib = Rib::new(NormalRibKind);
2319 // plain insert (no renaming, types are not currently hygienic....)
2320 let name = special_names::type_self;
2321 self_type_rib.bindings.insert(name, DlDef(self_def));
2322 self.type_ribs.push(self_type_rib);
2325 self.type_ribs.pop();
2329 fn resolve_implementation(&mut self,
2330 generics: &Generics,
2331 opt_trait_reference: &Option<TraitRef>,
2334 impl_items: &[ImplItem]) {
2335 // If applicable, create a rib for the type parameters.
2336 self.with_type_parameter_rib(HasTypeParameters(generics,
2340 // Resolve the type parameters.
2341 this.visit_generics(generics);
2343 // Resolve the trait reference, if necessary.
2344 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2345 // Resolve the self type.
2346 this.visit_ty(self_type);
2348 this.with_self_rib(Def::SelfTy(trait_id, Some((item_id, self_type.id))), |this| {
2349 this.with_current_self_type(self_type, |this| {
2350 for impl_item in impl_items {
2351 match impl_item.node {
2352 hir::ImplItemKind::Const(..) => {
2353 // If this is a trait impl, ensure the const
2355 this.check_trait_item(impl_item.name,
2357 |n, s| ResolutionError::ConstNotMemberOfTrait(n, s));
2358 this.with_constant_rib(|this| {
2359 intravisit::walk_impl_item(this, impl_item);
2362 hir::ImplItemKind::Method(ref sig, _) => {
2363 // If this is a trait impl, ensure the method
2365 this.check_trait_item(impl_item.name,
2367 |n, s| ResolutionError::MethodNotMemberOfTrait(n, s));
2369 // We also need a new scope for the method-
2370 // specific type parameters.
2371 let type_parameters =
2372 HasTypeParameters(&sig.generics,
2375 this.with_type_parameter_rib(type_parameters, |this| {
2376 intravisit::walk_impl_item(this, impl_item);
2379 hir::ImplItemKind::Type(ref ty) => {
2380 // If this is a trait impl, ensure the type
2382 this.check_trait_item(impl_item.name,
2384 |n, s| ResolutionError::TypeNotMemberOfTrait(n, s));
2396 fn check_trait_item<F>(&self, name: Name, span: Span, err: F)
2397 where F: FnOnce(Name, &str) -> ResolutionError
2399 // If there is a TraitRef in scope for an impl, then the method must be in the
2401 if let Some((did, ref trait_ref)) = self.current_trait_ref {
2402 if !self.trait_item_map.contains_key(&(name, did)) {
2403 let path_str = path_names_to_string(&trait_ref.path, 0);
2404 resolve_error(self, span, err(name, &*path_str));
2409 fn resolve_local(&mut self, local: &Local) {
2410 // Resolve the type.
2411 walk_list!(self, visit_ty, &local.ty);
2413 // Resolve the initializer.
2414 walk_list!(self, visit_expr, &local.init);
2416 // Resolve the pattern.
2417 self.resolve_pattern(&*local.pat, LocalIrrefutableMode, &mut HashMap::new());
2420 // build a map from pattern identifiers to binding-info's.
2421 // this is done hygienically. This could arise for a macro
2422 // that expands into an or-pattern where one 'x' was from the
2423 // user and one 'x' came from the macro.
2424 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2425 let mut result = HashMap::new();
2426 pat_bindings(&self.def_map, pat, |binding_mode, _id, sp, path1| {
2427 let name = path1.node;
2431 binding_mode: binding_mode,
2437 // check that all of the arms in an or-pattern have exactly the
2438 // same set of bindings, with the same binding modes for each.
2439 fn check_consistent_bindings(&mut self, arm: &Arm) {
2440 if arm.pats.is_empty() {
2443 let map_0 = self.binding_mode_map(&*arm.pats[0]);
2444 for (i, p) in arm.pats.iter().enumerate() {
2445 let map_i = self.binding_mode_map(&**p);
2447 for (&key, &binding_0) in &map_0 {
2448 match map_i.get(&key) {
2452 ResolutionError::VariableNotBoundInPattern(key, i + 1));
2454 Some(binding_i) => {
2455 if binding_0.binding_mode != binding_i.binding_mode {
2458 ResolutionError::VariableBoundWithDifferentMode(key,
2465 for (&key, &binding) in &map_i {
2466 if !map_0.contains_key(&key) {
2469 ResolutionError::VariableNotBoundInParentPattern(key, i + 1));
2475 fn resolve_arm(&mut self, arm: &Arm) {
2476 self.value_ribs.push(Rib::new(NormalRibKind));
2478 let mut bindings_list = HashMap::new();
2479 for pattern in &arm.pats {
2480 self.resolve_pattern(&**pattern, RefutableMode, &mut bindings_list);
2483 // This has to happen *after* we determine which
2484 // pat_idents are variants
2485 self.check_consistent_bindings(arm);
2487 walk_list!(self, visit_expr, &arm.guard);
2488 self.visit_expr(&*arm.body);
2491 self.value_ribs.pop();
2495 fn resolve_block(&mut self, block: &Block) {
2496 debug!("(resolving block) entering block");
2497 // Move down in the graph, if there's an anonymous module rooted here.
2498 let orig_module = self.current_module;
2499 let anonymous_module =
2500 orig_module.anonymous_children.borrow().get(&block.id).map(|module| *module);
2502 if let Some(anonymous_module) = anonymous_module {
2503 debug!("(resolving block) found anonymous module, moving down");
2504 self.value_ribs.push(Rib::new(AnonymousModuleRibKind(anonymous_module)));
2505 self.type_ribs.push(Rib::new(AnonymousModuleRibKind(anonymous_module)));
2506 self.current_module = anonymous_module;
2508 self.value_ribs.push(Rib::new(NormalRibKind));
2511 // Check for imports appearing after non-item statements.
2512 let mut found_non_item = false;
2513 for statement in &block.stmts {
2514 if let hir::StmtDecl(ref declaration, _) = statement.node {
2515 if let hir::DeclItem(i) = declaration.node {
2516 let i = self.ast_map.expect_item(i.id);
2518 ItemExternCrate(_) | ItemUse(_) if found_non_item => {
2519 span_err!(self.session,
2522 "imports are not allowed after non-item statements");
2527 found_non_item = true
2530 found_non_item = true;
2534 // Descend into the block.
2535 intravisit::walk_block(self, block);
2539 self.current_module = orig_module;
2540 self.value_ribs.pop();
2541 if let Some(_) = anonymous_module {
2542 self.type_ribs.pop();
2545 debug!("(resolving block) leaving block");
2548 fn resolve_type(&mut self, ty: &Ty) {
2550 TyPath(ref maybe_qself, ref path) => {
2551 let resolution = match self.resolve_possibly_assoc_item(ty.id,
2552 maybe_qself.as_ref(),
2556 // `<T>::a::b::c` is resolved by typeck alone.
2557 TypecheckRequired => {
2558 // Resolve embedded types.
2559 intravisit::walk_ty(self, ty);
2562 ResolveAttempt(resolution) => resolution,
2565 // This is a path in the type namespace. Walk through scopes
2569 // Write the result into the def map.
2570 debug!("(resolving type) writing resolution for `{}` (id {}) = {:?}",
2571 path_names_to_string(path, 0),
2574 self.record_def(ty.id, def);
2577 self.record_def(ty.id, err_path_resolution());
2579 // Keep reporting some errors even if they're ignored above.
2580 self.resolve_path(ty.id, path, 0, TypeNS, true);
2582 let kind = if maybe_qself.is_some() {
2588 let self_type_name = special_idents::type_self.name;
2589 let is_invalid_self_type_name = path.segments.len() > 0 &&
2590 maybe_qself.is_none() &&
2591 path.segments[0].identifier.name ==
2593 if is_invalid_self_type_name {
2596 ResolutionError::SelfUsedOutsideImplOrTrait);
2600 ResolutionError::UseOfUndeclared(
2602 &*path_names_to_string(path,
2611 // Resolve embedded types.
2612 intravisit::walk_ty(self, ty);
2615 fn resolve_pattern(&mut self,
2617 mode: PatternBindingMode,
2618 // Maps idents to the node ID for the (outermost)
2619 // pattern that binds them
2620 bindings_list: &mut HashMap<Name, NodeId>) {
2621 let pat_id = pattern.id;
2622 walk_pat(pattern, |pattern| {
2623 match pattern.node {
2624 PatIdent(binding_mode, ref path1, ref at_rhs) => {
2625 // The meaning of PatIdent with no type parameters
2626 // depends on whether an enum variant or unit-like struct
2627 // with that name is in scope. The probing lookup has to
2628 // be careful not to emit spurious errors. Only matching
2629 // patterns (match) can match nullary variants or
2630 // unit-like structs. For binding patterns (let
2631 // and the LHS of @-patterns), matching such a value is
2632 // simply disallowed (since it's rarely what you want).
2633 let const_ok = mode == RefutableMode && at_rhs.is_none();
2635 let ident = path1.node;
2636 let renamed = ident.name;
2638 match self.resolve_bare_identifier_pattern(ident.unhygienic_name,
2640 FoundStructOrEnumVariant(def, lp) if const_ok => {
2641 debug!("(resolving pattern) resolving `{}` to struct or enum variant",
2644 self.enforce_default_binding_mode(pattern,
2647 self.record_def(pattern.id,
2654 FoundStructOrEnumVariant(..) => {
2658 ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(
2661 self.record_def(pattern.id, err_path_resolution());
2663 FoundConst(def, lp, _) if const_ok => {
2664 debug!("(resolving pattern) resolving `{}` to constant", renamed);
2666 self.enforce_default_binding_mode(pattern, binding_mode, "a constant");
2667 self.record_def(pattern.id,
2674 FoundConst(def, _, name) => {
2678 ResolutionError::OnlyIrrefutablePatternsAllowedHere(def.def_id(),
2681 self.record_def(pattern.id, err_path_resolution());
2683 BareIdentifierPatternUnresolved => {
2684 debug!("(resolving pattern) binding `{}`", renamed);
2686 let def_id = self.ast_map.local_def_id(pattern.id);
2687 let def = Def::Local(def_id, pattern.id);
2689 // Record the definition so that later passes
2690 // will be able to distinguish variants from
2691 // locals in patterns.
2693 self.record_def(pattern.id,
2696 last_private: LastMod(AllPublic),
2700 // Add the binding to the local ribs, if it
2701 // doesn't already exist in the bindings list. (We
2702 // must not add it if it's in the bindings list
2703 // because that breaks the assumptions later
2704 // passes make about or-patterns.)
2705 if !bindings_list.contains_key(&renamed) {
2706 let this = &mut *self;
2707 let last_rib = this.value_ribs.last_mut().unwrap();
2708 last_rib.bindings.insert(renamed, DlDef(def));
2709 bindings_list.insert(renamed, pat_id);
2710 } else if mode == ArgumentIrrefutableMode &&
2711 bindings_list.contains_key(&renamed) {
2712 // Forbid duplicate bindings in the same
2717 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2718 &ident.name.as_str())
2720 } else if bindings_list.get(&renamed) == Some(&pat_id) {
2721 // Then this is a duplicate variable in the
2722 // same disjunction, which is an error.
2726 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2727 &ident.name.as_str())
2730 // Else, not bound in the same pattern: do
2736 PatEnum(ref path, _) => {
2737 // This must be an enum variant, struct or const.
2738 let resolution = match self.resolve_possibly_assoc_item(pat_id,
2743 // The below shouldn't happen because all
2744 // qualified paths should be in PatQPath.
2745 TypecheckRequired =>
2746 self.session.span_bug(path.span,
2747 "resolve_possibly_assoc_item claimed
2749 that a path in PatEnum requires typecheck
2751 to resolve, but qualified paths should be
2754 ResolveAttempt(resolution) => resolution,
2756 if let Some(path_res) = resolution {
2757 match path_res.base_def {
2758 Def::Struct(..) if path_res.depth == 0 => {
2759 self.record_def(pattern.id, path_res);
2761 Def::Variant(..) | Def::Const(..) => {
2762 self.record_def(pattern.id, path_res);
2764 Def::Static(..) => {
2765 resolve_error(&self,
2767 ResolutionError::StaticVariableReference);
2768 self.record_def(pattern.id, err_path_resolution());
2771 // If anything ends up here entirely resolved,
2772 // it's an error. If anything ends up here
2773 // partially resolved, that's OK, because it may
2774 // be a `T::CONST` that typeck will resolve.
2775 if path_res.depth == 0 {
2779 ResolutionError::NotAnEnumVariantStructOrConst(
2787 self.record_def(pattern.id, err_path_resolution());
2789 let const_name = path.segments
2794 let traits = self.get_traits_containing_item(const_name);
2795 self.trait_map.insert(pattern.id, traits);
2796 self.record_def(pattern.id, path_res);
2804 ResolutionError::UnresolvedEnumVariantStructOrConst(
2805 &path.segments.last().unwrap().identifier.name.as_str())
2807 self.record_def(pattern.id, err_path_resolution());
2809 intravisit::walk_path(self, path);
2812 PatQPath(ref qself, ref path) => {
2813 // Associated constants only.
2814 let resolution = match self.resolve_possibly_assoc_item(pat_id,
2819 TypecheckRequired => {
2820 // All `<T>::CONST` should end up here, and will
2821 // require use of the trait map to resolve
2822 // during typechecking.
2823 let const_name = path.segments
2828 let traits = self.get_traits_containing_item(const_name);
2829 self.trait_map.insert(pattern.id, traits);
2830 intravisit::walk_pat(self, pattern);
2833 ResolveAttempt(resolution) => resolution,
2835 if let Some(path_res) = resolution {
2836 match path_res.base_def {
2837 // All `<T as Trait>::CONST` should end up here, and
2838 // have the trait already selected.
2839 Def::AssociatedConst(..) => {
2840 self.record_def(pattern.id, path_res);
2846 ResolutionError::NotAnAssociatedConst(
2847 &path.segments.last().unwrap().identifier.name.as_str()
2850 self.record_def(pattern.id, err_path_resolution());
2856 ResolutionError::UnresolvedAssociatedConst(&path.segments
2862 self.record_def(pattern.id, err_path_resolution());
2864 intravisit::walk_pat(self, pattern);
2867 PatStruct(ref path, _, _) => {
2868 match self.resolve_path(pat_id, path, 0, TypeNS, false) {
2869 Some(definition) => {
2870 self.record_def(pattern.id, definition);
2873 debug!("(resolving pattern) didn't find struct def: {:?}", result);
2877 ResolutionError::DoesNotNameAStruct(
2878 &*path_names_to_string(path, 0))
2880 self.record_def(pattern.id, err_path_resolution());
2883 intravisit::walk_path(self, path);
2886 PatLit(_) | PatRange(..) => {
2887 intravisit::walk_pat(self, pattern);
2898 fn resolve_bare_identifier_pattern(&mut self,
2901 -> BareIdentifierPatternResolution {
2902 let module = self.current_module;
2903 match self.resolve_item_in_lexical_scope(module, name, ValueNS, true) {
2904 Success((target, _)) => {
2905 debug!("(resolve bare identifier pattern) succeeded in finding {} at {:?}",
2907 target.binding.borrow());
2908 match target.binding.def() {
2910 panic!("resolved name in the value namespace to a set of name bindings \
2913 // For the two success cases, this lookup can be
2914 // considered as not having a private component because
2915 // the lookup happened only within the current module.
2916 Some(def @ Def::Variant(..)) | Some(def @ Def::Struct(..)) => {
2917 return FoundStructOrEnumVariant(def, LastMod(AllPublic));
2919 Some(def @ Def::Const(..)) | Some(def @ Def::AssociatedConst(..)) => {
2920 return FoundConst(def, LastMod(AllPublic), name);
2922 Some(Def::Static(..)) => {
2923 resolve_error(self, span, ResolutionError::StaticVariableReference);
2924 return BareIdentifierPatternUnresolved;
2926 _ => return BareIdentifierPatternUnresolved
2930 Indeterminate => return BareIdentifierPatternUnresolved,
2933 Some((span, msg)) => {
2934 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
2939 debug!("(resolve bare identifier pattern) failed to find {}", name);
2940 return BareIdentifierPatternUnresolved;
2945 /// Handles paths that may refer to associated items
2946 fn resolve_possibly_assoc_item(&mut self,
2948 maybe_qself: Option<&hir::QSelf>,
2950 namespace: Namespace,
2952 -> AssocItemResolveResult {
2953 let max_assoc_types;
2957 if qself.position == 0 {
2958 return TypecheckRequired;
2960 max_assoc_types = path.segments.len() - qself.position;
2961 // Make sure the trait is valid.
2962 let _ = self.resolve_trait_reference(id, path, max_assoc_types);
2965 max_assoc_types = path.segments.len();
2969 let mut resolution = self.with_no_errors(|this| {
2970 this.resolve_path(id, path, 0, namespace, check_ribs)
2972 for depth in 1..max_assoc_types {
2973 if resolution.is_some() {
2976 self.with_no_errors(|this| {
2977 resolution = this.resolve_path(id, path, depth, TypeNS, true);
2980 if let Some(Def::Mod(_)) = resolution.map(|r| r.base_def) {
2981 // A module is not a valid type or value.
2984 ResolveAttempt(resolution)
2987 /// If `check_ribs` is true, checks the local definitions first; i.e.
2988 /// doesn't skip straight to the containing module.
2989 /// Skips `path_depth` trailing segments, which is also reflected in the
2990 /// returned value. See `middle::def::PathResolution` for more info.
2991 pub fn resolve_path(&mut self,
2995 namespace: Namespace,
2997 -> Option<PathResolution> {
2998 let span = path.span;
2999 let segments = &path.segments[..path.segments.len() - path_depth];
3001 let mk_res = |(def, lp)| PathResolution::new(def, lp, path_depth);
3004 let def = self.resolve_crate_relative_path(span, segments, namespace);
3005 return def.map(mk_res);
3008 // Try to find a path to an item in a module.
3009 let last_ident = segments.last().unwrap().identifier;
3010 if segments.len() <= 1 {
3011 let unqualified_def = self.resolve_identifier(last_ident, namespace, check_ribs, true);
3012 return unqualified_def.and_then(|def| self.adjust_local_def(def, span))
3014 PathResolution::new(def, LastMod(AllPublic), path_depth)
3018 let unqualified_def = self.resolve_identifier(last_ident, namespace, check_ribs, false);
3019 let def = self.resolve_module_relative_path(span, segments, namespace);
3020 match (def, unqualified_def) {
3021 (Some((ref d, _)), Some(ref ud)) if *d == ud.def => {
3023 .add_lint(lint::builtin::UNUSED_QUALIFICATIONS,
3026 "unnecessary qualification".to_string());
3034 // Resolve a single identifier
3035 fn resolve_identifier(&mut self,
3036 identifier: hir::Ident,
3037 namespace: Namespace,
3040 -> Option<LocalDef> {
3041 if identifier.name == special_idents::invalid.name {
3042 return Some(LocalDef::from_def(Def::Err));
3045 // First, check to see whether the name is a primitive type.
3046 if namespace == TypeNS {
3047 if let Some(&prim_ty) = self.primitive_type_table
3049 .get(&identifier.unhygienic_name) {
3050 return Some(LocalDef::from_def(Def::PrimTy(prim_ty)));
3055 if let Some(def) = self.resolve_identifier_in_local_ribs(identifier, namespace) {
3060 let name = identifier.unhygienic_name;
3061 self.resolve_item_by_name_in_lexical_scope(name, namespace, record_used)
3062 .map(LocalDef::from_def)
3065 // Resolve a local definition, potentially adjusting for closures.
3066 fn adjust_local_def(&mut self, local_def: LocalDef, span: Span) -> Option<Def> {
3067 let ribs = match local_def.ribs {
3068 Some((TypeNS, i)) => &self.type_ribs[i + 1..],
3069 Some((ValueNS, i)) => &self.value_ribs[i + 1..],
3072 let mut def = local_def.def;
3075 self.session.span_bug(span, &format!("unexpected {:?} in bindings", def))
3077 Def::Local(_, node_id) => {
3080 NormalRibKind | AnonymousModuleRibKind(..) => {
3081 // Nothing to do. Continue.
3083 ClosureRibKind(function_id) => {
3085 let node_def_id = self.ast_map.local_def_id(node_id);
3087 let seen = self.freevars_seen
3089 .or_insert_with(|| NodeMap());
3090 if let Some(&index) = seen.get(&node_id) {
3091 def = Def::Upvar(node_def_id, node_id, index, function_id);
3094 let vec = self.freevars
3096 .or_insert_with(|| vec![]);
3097 let depth = vec.len();
3103 def = Def::Upvar(node_def_id, node_id, depth, function_id);
3104 seen.insert(node_id, depth);
3106 ItemRibKind | MethodRibKind => {
3107 // This was an attempt to access an upvar inside a
3108 // named function item. This is not allowed, so we
3112 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
3115 ConstantItemRibKind => {
3116 // Still doesn't deal with upvars
3119 ResolutionError::AttemptToUseNonConstantValueInConstant);
3125 Def::TyParam(..) | Def::SelfTy(..) => {
3128 NormalRibKind | MethodRibKind | ClosureRibKind(..) |
3129 AnonymousModuleRibKind(..) => {
3130 // Nothing to do. Continue.
3133 // This was an attempt to use a type parameter outside
3138 ResolutionError::TypeParametersFromOuterFunction);
3141 ConstantItemRibKind => {
3143 resolve_error(self, span, ResolutionError::OuterTypeParameterContext);
3154 // resolve a "module-relative" path, e.g. a::b::c
3155 fn resolve_module_relative_path(&mut self,
3157 segments: &[hir::PathSegment],
3158 namespace: Namespace)
3159 -> Option<(Def, LastPrivate)> {
3160 let module_path = segments.split_last()
3164 .map(|ps| ps.identifier.name)
3165 .collect::<Vec<_>>();
3167 let containing_module;
3169 let current_module = self.current_module;
3170 match self.resolve_module_path(current_module,
3176 let (span, msg) = match err {
3177 Some((span, msg)) => (span, msg),
3179 let msg = format!("Use of undeclared type or module `{}`",
3180 names_to_string(&module_path));
3185 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3188 Indeterminate => return None,
3189 Success((resulting_module, resulting_last_private)) => {
3190 containing_module = resulting_module;
3191 last_private = resulting_last_private;
3195 let name = segments.last().unwrap().identifier.name;
3196 let def = match self.resolve_name_in_module(containing_module,
3199 NameSearchType::PathSearch,
3201 Success((Target { binding, .. }, _)) => {
3202 let (def, lp) = binding.def_and_lp();
3203 (def, last_private.or(lp))
3207 if let Some(DefId{krate: kid, ..}) = containing_module.def_id() {
3208 self.used_crates.insert(kid);
3213 /// Invariant: This must be called only during main resolution, not during
3214 /// import resolution.
3215 fn resolve_crate_relative_path(&mut self,
3217 segments: &[hir::PathSegment],
3218 namespace: Namespace)
3219 -> Option<(Def, LastPrivate)> {
3220 let module_path = segments.split_last()
3224 .map(|ps| ps.identifier.name)
3225 .collect::<Vec<_>>();
3227 let root_module = self.graph_root;
3229 let containing_module;
3231 match self.resolve_module_path_from_root(root_module,
3236 LastMod(AllPublic)) {
3238 let (span, msg) = match err {
3239 Some((span, msg)) => (span, msg),
3241 let msg = format!("Use of undeclared module `::{}`",
3242 names_to_string(&module_path[..]));
3247 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3251 Indeterminate => return None,
3253 Success((resulting_module, resulting_last_private)) => {
3254 containing_module = resulting_module;
3255 last_private = resulting_last_private;
3259 let name = segments.last().unwrap().identifier.name;
3260 match self.resolve_name_in_module(containing_module,
3263 NameSearchType::PathSearch,
3265 Success((Target { binding, .. }, _)) => {
3266 let (def, lp) = binding.def_and_lp();
3267 Some((def, last_private.or(lp)))
3273 fn resolve_identifier_in_local_ribs(&mut self,
3275 namespace: Namespace)
3276 -> Option<LocalDef> {
3277 // Check the local set of ribs.
3278 let name = match namespace { ValueNS => ident.name, TypeNS => ident.unhygienic_name };
3280 for i in (0 .. self.get_ribs(namespace).len()).rev() {
3281 if let Some(def_like) = self.get_ribs(namespace)[i].bindings.get(&name).cloned() {
3284 debug!("(resolving path in local ribs) resolved `{}` to {:?} at {}",
3288 return Some(LocalDef {
3289 ribs: Some((namespace, i)),
3294 debug!("(resolving path in local ribs) resolved `{}` to pseudo-def {:?}",
3302 if let AnonymousModuleRibKind(module) = self.get_ribs(namespace)[i].kind {
3303 if let Success((target, _)) = self.resolve_name_in_module(module,
3304 ident.unhygienic_name,
3308 if let Some(def) = target.binding.def() {
3309 return Some(LocalDef::from_def(def));
3318 fn resolve_item_by_name_in_lexical_scope(&mut self,
3320 namespace: Namespace,
3324 let module = self.current_module;
3325 match self.resolve_item_in_lexical_scope(module, name, namespace, record_used) {
3326 Success((target, _)) => {
3327 match target.binding.def() {
3329 // This can happen if we were looking for a type and
3330 // found a module instead. Modules don't have defs.
3331 debug!("(resolving item path by identifier in lexical scope) failed to \
3332 resolve {} after success...",
3337 debug!("(resolving item path in lexical scope) resolved `{}` to item",
3339 // This lookup is "all public" because it only searched
3340 // for one identifier in the current module (couldn't
3341 // have passed through reexports or anything like that.
3346 Indeterminate => None,
3348 debug!("(resolving item path by identifier in lexical scope) failed to resolve {}",
3351 if let Some((span, msg)) = err {
3352 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg))
3360 fn with_no_errors<T, F>(&mut self, f: F) -> T
3361 where F: FnOnce(&mut Resolver) -> T
3363 self.emit_errors = false;
3365 self.emit_errors = true;
3369 fn find_fallback_in_self_type(&mut self, name: Name) -> FallbackSuggestion {
3370 fn extract_path_and_node_id(t: &Ty,
3371 allow: FallbackChecks)
3372 -> Option<(Path, NodeId, FallbackChecks)> {
3374 TyPath(None, ref path) => Some((path.clone(), t.id, allow)),
3375 TyPtr(ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, OnlyTraitAndStatics),
3376 TyRptr(_, ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, allow),
3377 // This doesn't handle the remaining `Ty` variants as they are not
3378 // that commonly the self_type, it might be interesting to provide
3379 // support for those in future.
3384 fn get_module<'a, 'tcx>(this: &mut Resolver<'a, 'tcx>,
3386 name_path: &[ast::Name])
3387 -> Option<Module<'a>> {
3388 let root = this.current_module;
3389 let last_name = name_path.last().unwrap();
3391 if name_path.len() == 1 {
3392 match this.primitive_type_table.primitive_types.get(last_name) {
3395 match this.current_module.children.borrow().get(last_name) {
3396 Some(child) => child.type_ns.module(),
3402 match this.resolve_module_path(root,
3407 Success((module, _)) => Some(module),
3413 fn is_static_method(this: &Resolver, did: DefId) -> bool {
3414 if let Some(node_id) = this.ast_map.as_local_node_id(did) {
3415 let sig = match this.ast_map.get(node_id) {
3416 hir_map::NodeTraitItem(trait_item) => match trait_item.node {
3417 hir::MethodTraitItem(ref sig, _) => sig,
3420 hir_map::NodeImplItem(impl_item) => match impl_item.node {
3421 hir::ImplItemKind::Method(ref sig, _) => sig,
3426 sig.explicit_self.node == hir::SelfStatic
3428 this.session.cstore.is_static_method(did)
3432 let (path, node_id, allowed) = match self.current_self_type {
3433 Some(ref ty) => match extract_path_and_node_id(ty, Everything) {
3435 None => return NoSuggestion,
3437 None => return NoSuggestion,
3440 if allowed == Everything {
3441 // Look for a field with the same name in the current self_type.
3442 match self.def_map.borrow().get(&node_id).map(|d| d.full_def()) {
3443 Some(Def::Enum(did)) |
3444 Some(Def::TyAlias(did)) |
3445 Some(Def::Struct(did)) |
3446 Some(Def::Variant(_, did)) => match self.structs.get(&did) {
3449 if fields.iter().any(|&field_name| name == field_name) {
3454 _ => {} // Self type didn't resolve properly
3458 let name_path = path.segments.iter().map(|seg| seg.identifier.name).collect::<Vec<_>>();
3460 // Look for a method in the current self type's impl module.
3461 if let Some(module) = get_module(self, path.span, &name_path) {
3462 if let Some(binding) = module.children.borrow().get(&name) {
3463 if let Some(Def::Method(did)) = binding.value_ns.def() {
3464 if is_static_method(self, did) {
3465 return StaticMethod(path_names_to_string(&path, 0));
3467 if self.current_trait_ref.is_some() {
3469 } else if allowed == Everything {
3476 // Look for a method in the current trait.
3477 if let Some((trait_did, ref trait_ref)) = self.current_trait_ref {
3478 if let Some(&did) = self.trait_item_map.get(&(name, trait_did)) {
3479 if is_static_method(self, did) {
3480 return TraitMethod(path_names_to_string(&trait_ref.path, 0));
3490 fn find_best_match(&mut self, name: &str) -> SuggestionType {
3491 if let Some(macro_name) = self.session.available_macros
3492 .borrow().iter().find(|n| n.as_str() == name) {
3493 return SuggestionType::Macro(format!("{}!", macro_name));
3496 let names = self.value_ribs
3499 .flat_map(|rib| rib.bindings.keys());
3501 if let Some(found) = find_best_match_for_name(names, name, None) {
3502 if name != &*found {
3503 return SuggestionType::Function(found);
3505 } SuggestionType::NotFound
3508 fn resolve_expr(&mut self, expr: &Expr) {
3509 // First, record candidate traits for this expression if it could
3510 // result in the invocation of a method call.
3512 self.record_candidate_traits_for_expr_if_necessary(expr);
3514 // Next, resolve the node.
3516 ExprPath(ref maybe_qself, ref path) => {
3517 let resolution = match self.resolve_possibly_assoc_item(expr.id,
3518 maybe_qself.as_ref(),
3522 // `<T>::a::b::c` is resolved by typeck alone.
3523 TypecheckRequired => {
3524 let method_name = path.segments.last().unwrap().identifier.name;
3525 let traits = self.get_traits_containing_item(method_name);
3526 self.trait_map.insert(expr.id, traits);
3527 intravisit::walk_expr(self, expr);
3530 ResolveAttempt(resolution) => resolution,
3533 // This is a local path in the value namespace. Walk through
3534 // scopes looking for it.
3535 if let Some(path_res) = resolution {
3536 // Check if struct variant
3537 let is_struct_variant = if let Def::Variant(_, variant_id) = path_res.base_def {
3538 self.structs.contains_key(&variant_id)
3542 if is_struct_variant {
3543 let _ = self.structs.contains_key(&path_res.base_def.def_id());
3544 let path_name = path_names_to_string(path, 0);
3546 let mut err = resolve_struct_error(self,
3548 ResolutionError::StructVariantUsedAsFunction(&*path_name));
3550 let msg = format!("did you mean to write: `{} {{ /* fields */ }}`?",
3552 if self.emit_errors {
3553 err.fileline_help(expr.span, &msg);
3555 err.span_help(expr.span, &msg);
3558 self.record_def(expr.id, err_path_resolution());
3560 // Write the result into the def map.
3561 debug!("(resolving expr) resolved `{}`",
3562 path_names_to_string(path, 0));
3564 // Partial resolutions will need the set of traits in scope,
3565 // so they can be completed during typeck.
3566 if path_res.depth != 0 {
3567 let method_name = path.segments.last().unwrap().identifier.name;
3568 let traits = self.get_traits_containing_item(method_name);
3569 self.trait_map.insert(expr.id, traits);
3572 self.record_def(expr.id, path_res);
3575 // Be helpful if the name refers to a struct
3576 // (The pattern matching def_tys where the id is in self.structs
3577 // matches on regular structs while excluding tuple- and enum-like
3578 // structs, which wouldn't result in this error.)
3579 let path_name = path_names_to_string(path, 0);
3580 let type_res = self.with_no_errors(|this| {
3581 this.resolve_path(expr.id, path, 0, TypeNS, false)
3584 self.record_def(expr.id, err_path_resolution());
3585 match type_res.map(|r| r.base_def) {
3586 Some(Def::Struct(..)) => {
3587 let mut err = resolve_struct_error(self,
3589 ResolutionError::StructVariantUsedAsFunction(&*path_name));
3591 let msg = format!("did you mean to write: `{} {{ /* fields */ }}`?",
3593 if self.emit_errors {
3594 err.fileline_help(expr.span, &msg);
3596 err.span_help(expr.span, &msg);
3601 // Keep reporting some errors even if they're ignored above.
3602 self.resolve_path(expr.id, path, 0, ValueNS, true);
3604 let mut method_scope = false;
3605 self.value_ribs.iter().rev().all(|rib| {
3606 method_scope = match rib.kind {
3607 MethodRibKind => true,
3608 ItemRibKind | ConstantItemRibKind => false,
3609 _ => return true, // Keep advancing
3611 false // Stop advancing
3614 if method_scope && special_names::self_.as_str() == &path_name[..] {
3617 ResolutionError::SelfNotAvailableInStaticMethod);
3619 let last_name = path.segments.last().unwrap().identifier.name;
3620 let mut msg = match self.find_fallback_in_self_type(last_name) {
3622 // limit search to 5 to reduce the number
3623 // of stupid suggestions
3624 match self.find_best_match(&path_name) {
3625 SuggestionType::Macro(s) => {
3626 format!("the macro `{}`", s)
3628 SuggestionType::Function(s) => format!("`{}`", s),
3629 SuggestionType::NotFound => "".to_string(),
3632 Field => format!("`self.{}`", path_name),
3634 TraitItem => format!("to call `self.{}`", path_name),
3635 TraitMethod(path_str) |
3636 StaticMethod(path_str) =>
3637 format!("to call `{}::{}`", path_str, path_name),
3640 let mut context = UnresolvedNameContext::Other;
3641 if !msg.is_empty() {
3642 msg = format!(". Did you mean {}?", msg);
3644 // we check if this a module and if so, we display a help
3646 let name_path = path.segments.iter()
3647 .map(|seg| seg.identifier.name)
3648 .collect::<Vec<_>>();
3649 let current_module = self.current_module;
3651 match self.resolve_module_path(current_module,
3657 context = UnresolvedNameContext::PathIsMod(expr.id);
3665 ResolutionError::UnresolvedName(
3666 &*path_name, &*msg, context));
3672 intravisit::walk_expr(self, expr);
3675 ExprStruct(ref path, _, _) => {
3676 // Resolve the path to the structure it goes to. We don't
3677 // check to ensure that the path is actually a structure; that
3678 // is checked later during typeck.
3679 match self.resolve_path(expr.id, path, 0, TypeNS, false) {
3680 Some(definition) => self.record_def(expr.id, definition),
3682 debug!("(resolving expression) didn't find struct def",);
3686 ResolutionError::DoesNotNameAStruct(
3687 &*path_names_to_string(path, 0))
3689 self.record_def(expr.id, err_path_resolution());
3693 intravisit::walk_expr(self, expr);
3696 ExprLoop(_, Some(label)) | ExprWhile(_, _, Some(label)) => {
3697 self.with_label_rib(|this| {
3698 let def_like = DlDef(Def::Label(expr.id));
3701 let rib = this.label_ribs.last_mut().unwrap();
3702 rib.bindings.insert(label.name, def_like);
3705 intravisit::walk_expr(this, expr);
3709 ExprBreak(Some(label)) | ExprAgain(Some(label)) => {
3710 match self.search_label(label.node.name) {
3712 self.record_def(expr.id, err_path_resolution());
3715 ResolutionError::UndeclaredLabel(&label.node.name.as_str()))
3717 Some(DlDef(def @ Def::Label(_))) => {
3718 // Since this def is a label, it is never read.
3719 self.record_def(expr.id,
3722 last_private: LastMod(AllPublic),
3727 self.session.span_bug(expr.span, "label wasn't mapped to a label def!")
3733 intravisit::walk_expr(self, expr);
3738 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3740 ExprField(_, name) => {
3741 // FIXME(#6890): Even though you can't treat a method like a
3742 // field, we need to add any trait methods we find that match
3743 // the field name so that we can do some nice error reporting
3744 // later on in typeck.
3745 let traits = self.get_traits_containing_item(name.node);
3746 self.trait_map.insert(expr.id, traits);
3748 ExprMethodCall(name, _, _) => {
3749 debug!("(recording candidate traits for expr) recording traits for {}",
3751 let traits = self.get_traits_containing_item(name.node);
3752 self.trait_map.insert(expr.id, traits);
3760 fn get_traits_containing_item(&mut self, name: Name) -> Vec<DefId> {
3761 debug!("(getting traits containing item) looking for '{}'", name);
3763 fn add_trait_info(found_traits: &mut Vec<DefId>, trait_def_id: DefId, name: Name) {
3764 debug!("(adding trait info) found trait {:?} for method '{}'",
3767 found_traits.push(trait_def_id);
3770 let mut found_traits = Vec::new();
3771 let mut search_module = self.current_module;
3773 // Look for the current trait.
3774 match self.current_trait_ref {
3775 Some((trait_def_id, _)) => {
3776 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3777 add_trait_info(&mut found_traits, trait_def_id, name);
3780 None => {} // Nothing to do.
3783 // Look for trait children.
3784 build_reduced_graph::populate_module_if_necessary(self, &search_module);
3787 for (_, child_names) in search_module.children.borrow().iter() {
3788 let def = match child_names.type_ns.def() {
3792 let trait_def_id = match def {
3793 Def::Trait(trait_def_id) => trait_def_id,
3796 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3797 add_trait_info(&mut found_traits, trait_def_id, name);
3802 // Look for imports.
3803 for (_, import) in search_module.import_resolutions.borrow().iter() {
3804 let target = match import.type_ns.target {
3806 Some(ref target) => target,
3808 let did = match target.binding.def() {
3809 Some(Def::Trait(trait_def_id)) => trait_def_id,
3810 Some(..) | None => continue,
3812 if self.trait_item_map.contains_key(&(name, did)) {
3813 add_trait_info(&mut found_traits, did, name);
3814 let id = import.type_ns.id;
3815 self.used_imports.insert((id, TypeNS));
3816 let trait_name = self.get_trait_name(did);
3817 self.record_import_use(id, trait_name);
3818 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id() {
3819 self.used_crates.insert(kid);
3824 match search_module.parent_link {
3825 NoParentLink | ModuleParentLink(..) => break,
3826 BlockParentLink(parent_module, _) => {
3827 search_module = parent_module;
3835 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
3836 debug!("(recording def) recording {:?} for {}", resolution, node_id);
3837 assert!(match resolution.last_private {
3838 LastImport{..} => false,
3841 "Import should only be used for `use` directives");
3843 if let Some(prev_res) = self.def_map.borrow_mut().insert(node_id, resolution) {
3844 let span = self.ast_map.opt_span(node_id).unwrap_or(codemap::DUMMY_SP);
3845 self.session.span_bug(span,
3846 &format!("path resolved multiple times ({:?} before, {:?} now)",
3852 fn enforce_default_binding_mode(&mut self,
3854 pat_binding_mode: BindingMode,
3856 match pat_binding_mode {
3857 BindByValue(_) => {}
3861 ResolutionError::CannotUseRefBindingModeWith(descr));
3869 // Diagnostics are not particularly efficient, because they're rarely
3873 #[allow(dead_code)] // useful for debugging
3874 fn dump_module(&mut self, module_: Module<'a>) {
3875 debug!("Dump of module `{}`:", module_to_string(&*module_));
3877 debug!("Children:");
3878 build_reduced_graph::populate_module_if_necessary(self, &module_);
3879 for (&name, _) in module_.children.borrow().iter() {
3880 debug!("* {}", name);
3883 debug!("Import resolutions:");
3884 let import_resolutions = module_.import_resolutions.borrow();
3885 for (&name, import_resolution) in import_resolutions.iter() {
3887 match import_resolution.value_ns.target {
3889 value_repr = "".to_string();
3892 value_repr = " value:?".to_string();
3898 match import_resolution.type_ns.target {
3900 type_repr = "".to_string();
3903 type_repr = " type:?".to_string();
3908 debug!("* {}:{}{}", name, value_repr, type_repr);
3914 fn names_to_string(names: &[Name]) -> String {
3915 let mut first = true;
3916 let mut result = String::new();
3921 result.push_str("::")
3923 result.push_str(&name.as_str());
3928 fn path_names_to_string(path: &Path, depth: usize) -> String {
3929 let names: Vec<ast::Name> = path.segments[..path.segments.len() - depth]
3931 .map(|seg| seg.identifier.name)
3933 names_to_string(&names[..])
3936 /// A somewhat inefficient routine to obtain the name of a module.
3937 fn module_to_string<'a>(module: Module<'a>) -> String {
3938 let mut names = Vec::new();
3940 fn collect_mod<'a>(names: &mut Vec<ast::Name>, module: Module<'a>) {
3941 match module.parent_link {
3943 ModuleParentLink(ref module, name) => {
3945 collect_mod(names, module);
3947 BlockParentLink(ref module, _) => {
3948 // danger, shouldn't be ident?
3949 names.push(special_idents::opaque.name);
3950 collect_mod(names, module);
3954 collect_mod(&mut names, module);
3956 if names.is_empty() {
3957 return "???".to_string();
3959 names_to_string(&names.into_iter().rev().collect::<Vec<ast::Name>>())
3962 fn err_path_resolution() -> PathResolution {
3965 last_private: LastMod(AllPublic),
3971 pub struct CrateMap {
3972 pub def_map: RefCell<DefMap>,
3973 pub freevars: FreevarMap,
3974 pub export_map: ExportMap,
3975 pub trait_map: TraitMap,
3976 pub external_exports: ExternalExports,
3977 pub glob_map: Option<GlobMap>,
3980 #[derive(PartialEq,Copy, Clone)]
3981 pub enum MakeGlobMap {
3986 /// Entry point to crate resolution.
3987 pub fn resolve_crate<'a, 'tcx>(session: &'a Session,
3988 ast_map: &'a hir_map::Map<'tcx>,
3989 make_glob_map: MakeGlobMap)
3991 let krate = ast_map.krate();
3992 let arenas = Resolver::arenas();
3993 let mut resolver = create_resolver(session, ast_map, krate, make_glob_map, &arenas, None);
3995 resolver.resolve_crate(krate);
3997 check_unused::check_crate(&mut resolver, krate);
4000 def_map: resolver.def_map,
4001 freevars: resolver.freevars,
4002 export_map: resolver.export_map,
4003 trait_map: resolver.trait_map,
4004 external_exports: resolver.external_exports,
4005 glob_map: if resolver.make_glob_map {
4006 Some(resolver.glob_map)
4013 /// Builds a name resolution walker to be used within this module,
4014 /// or used externally, with an optional callback function.
4016 /// The callback takes a &mut bool which allows callbacks to end a
4017 /// walk when set to true, passing through the rest of the walk, while
4018 /// preserving the ribs + current module. This allows resolve_path
4019 /// calls to be made with the correct scope info. The node in the
4020 /// callback corresponds to the current node in the walk.
4021 pub fn create_resolver<'a, 'tcx>(session: &'a Session,
4022 ast_map: &'a hir_map::Map<'tcx>,
4024 make_glob_map: MakeGlobMap,
4025 arenas: &'a ResolverArenas<'a>,
4026 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>)
4027 -> Resolver<'a, 'tcx> {
4028 let mut resolver = Resolver::new(session, ast_map, make_glob_map, arenas);
4030 resolver.callback = callback;
4032 build_reduced_graph::build_reduced_graph(&mut resolver, krate);
4034 resolve_imports::resolve_imports(&mut resolver);
4039 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }