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)]
30 extern crate syntax_pos;
31 extern crate rustc_errors as errors;
36 use self::Namespace::*;
37 use self::ResolveResult::*;
38 use self::FallbackSuggestion::*;
39 use self::TypeParameters::*;
41 use self::UseLexicalScopeFlag::*;
42 use self::ModulePrefixResult::*;
43 use self::ParentLink::*;
45 use rustc::hir::map::Definitions;
46 use rustc::hir::{self, PrimTy, TyBool, TyChar, TyFloat, TyInt, TyUint, TyStr};
47 use rustc::session::Session;
49 use rustc::hir::def::*;
50 use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId};
52 use rustc::hir::{Freevar, FreevarMap, TraitCandidate, TraitMap, GlobMap};
53 use rustc::util::nodemap::{NodeMap, NodeSet, FnvHashMap, FnvHashSet};
55 use syntax::ext::hygiene::Mark;
56 use syntax::ast::{self, FloatTy};
57 use syntax::ast::{CRATE_NODE_ID, Name, NodeId, CrateNum, IntTy, UintTy};
58 use syntax::parse::token::{self, keywords};
59 use syntax::util::lev_distance::find_best_match_for_name;
61 use syntax::visit::{self, FnKind, Visitor};
62 use syntax::ast::{Arm, BindingMode, Block, Crate, Expr, ExprKind};
63 use syntax::ast::{FnDecl, ForeignItem, ForeignItemKind, Generics};
64 use syntax::ast::{Item, ItemKind, ImplItem, ImplItemKind};
65 use syntax::ast::{Local, Mutability, Pat, PatKind, Path};
66 use syntax::ast::{PathSegment, PathParameters, QSelf, TraitItemKind, TraitRef, Ty, TyKind};
69 use errors::DiagnosticBuilder;
71 use std::collections::{HashMap, HashSet};
72 use std::cell::{Cell, RefCell};
74 use std::mem::replace;
76 use resolve_imports::{ImportDirective, NameResolution};
78 // NB: This module needs to be declared first so diagnostics are
79 // registered before they are used.
83 mod build_reduced_graph;
89 Function(token::InternedString),
93 /// Candidates for a name resolution failure
94 struct SuggestedCandidates {
96 candidates: Vec<Path>,
99 enum ResolutionError<'a> {
100 /// error E0401: can't use type parameters from outer function
101 TypeParametersFromOuterFunction,
102 /// error E0402: cannot use an outer type parameter in this context
103 OuterTypeParameterContext,
104 /// error E0403: the name is already used for a type parameter in this type parameter list
105 NameAlreadyUsedInTypeParameterList(Name),
106 /// error E0404: is not a trait
107 IsNotATrait(&'a str),
108 /// error E0405: use of undeclared trait name
109 UndeclaredTraitName(&'a str, SuggestedCandidates),
110 /// error E0407: method is not a member of trait
111 MethodNotMemberOfTrait(Name, &'a str),
112 /// error E0437: type is not a member of trait
113 TypeNotMemberOfTrait(Name, &'a str),
114 /// error E0438: const is not a member of trait
115 ConstNotMemberOfTrait(Name, &'a str),
116 /// error E0408: variable `{}` from pattern #{} is not bound in pattern #{}
117 VariableNotBoundInPattern(Name, usize, usize),
118 /// error E0409: variable is bound with different mode in pattern #{} than in pattern #1
119 VariableBoundWithDifferentMode(Name, usize, Span),
120 /// error E0411: use of `Self` outside of an impl or trait
121 SelfUsedOutsideImplOrTrait,
122 /// error E0412: use of undeclared
123 UseOfUndeclared(&'a str, &'a str, SuggestedCandidates),
124 /// error E0415: identifier is bound more than once in this parameter list
125 IdentifierBoundMoreThanOnceInParameterList(&'a str),
126 /// error E0416: identifier is bound more than once in the same pattern
127 IdentifierBoundMoreThanOnceInSamePattern(&'a str),
128 /// error E0422: does not name a struct
129 DoesNotNameAStruct(&'a str),
130 /// error E0423: is a struct variant name, but this expression uses it like a function name
131 StructVariantUsedAsFunction(&'a str),
132 /// error E0424: `self` is not available in a static method
133 SelfNotAvailableInStaticMethod,
134 /// error E0425: unresolved name
138 context: UnresolvedNameContext<'a>,
139 is_static_method: bool,
143 /// error E0426: use of undeclared label
144 UndeclaredLabel(&'a str),
145 /// error E0429: `self` imports are only allowed within a { } list
146 SelfImportsOnlyAllowedWithin,
147 /// error E0430: `self` import can only appear once in the list
148 SelfImportCanOnlyAppearOnceInTheList,
149 /// error E0431: `self` import can only appear in an import list with a non-empty prefix
150 SelfImportOnlyInImportListWithNonEmptyPrefix,
151 /// error E0432: unresolved import
152 UnresolvedImport(Option<(&'a str, &'a str)>),
153 /// error E0433: failed to resolve
154 FailedToResolve(&'a str),
155 /// error E0434: can't capture dynamic environment in a fn item
156 CannotCaptureDynamicEnvironmentInFnItem,
157 /// error E0435: attempt to use a non-constant value in a constant
158 AttemptToUseNonConstantValueInConstant,
159 /// error E0530: X bindings cannot shadow Ys
160 BindingShadowsSomethingUnacceptable(&'a str, Name, &'a NameBinding<'a>),
161 /// error E0531: unresolved pattern path kind `name`
162 PatPathUnresolved(&'a str, &'a Path),
163 /// error E0532: expected pattern path kind, found another pattern path kind
164 PatPathUnexpected(&'a str, &'a str, &'a Path),
167 /// Context of where `ResolutionError::UnresolvedName` arose.
168 #[derive(Clone, PartialEq, Eq, Debug)]
169 enum UnresolvedNameContext<'a> {
170 /// `PathIsMod(parent)` indicates that a given path, used in
171 /// expression context, actually resolved to a module rather than
172 /// a value. The optional expression attached to the variant is the
173 /// the parent of the erroneous path expression.
174 PathIsMod(Option<&'a Expr>),
176 /// `Other` means we have no extra information about the context
177 /// of the unresolved name error. (Maybe we could eliminate all
178 /// such cases; but for now, this is an information-free default.)
182 fn resolve_error<'b, 'a: 'b, 'c>(resolver: &'b Resolver<'a>,
183 span: syntax_pos::Span,
184 resolution_error: ResolutionError<'c>) {
185 resolve_struct_error(resolver, span, resolution_error).emit();
188 fn resolve_struct_error<'b, 'a: 'b, 'c>(resolver: &'b Resolver<'a>,
189 span: syntax_pos::Span,
190 resolution_error: ResolutionError<'c>)
191 -> DiagnosticBuilder<'a> {
192 if !resolver.emit_errors {
193 return resolver.session.diagnostic().struct_dummy();
196 match resolution_error {
197 ResolutionError::TypeParametersFromOuterFunction => {
198 let mut err = struct_span_err!(resolver.session,
201 "can't use type parameters from outer function; \
202 try using a local type parameter instead");
203 err.span_label(span, &format!("use of type variable from outer function"));
206 ResolutionError::OuterTypeParameterContext => {
207 struct_span_err!(resolver.session,
210 "cannot use an outer type parameter in this context")
212 ResolutionError::NameAlreadyUsedInTypeParameterList(name) => {
213 struct_span_err!(resolver.session,
216 "the name `{}` is already used for a type parameter in this type \
220 ResolutionError::IsNotATrait(name) => {
221 let mut err = struct_span_err!(resolver.session,
224 "`{}` is not a trait",
226 err.span_label(span, &format!("not a trait"));
229 ResolutionError::UndeclaredTraitName(name, candidates) => {
230 let mut err = struct_span_err!(resolver.session,
233 "trait `{}` is not in scope",
235 show_candidates(&mut err, &candidates);
236 err.span_label(span, &format!("`{}` is not in scope", name));
239 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
240 struct_span_err!(resolver.session,
243 "method `{}` is not a member of trait `{}`",
247 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
248 struct_span_err!(resolver.session,
251 "type `{}` is not a member of trait `{}`",
255 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
256 struct_span_err!(resolver.session,
259 "const `{}` is not a member of trait `{}`",
263 ResolutionError::VariableNotBoundInPattern(variable_name, from, to) => {
264 struct_span_err!(resolver.session,
267 "variable `{}` from pattern #{} is not bound in pattern #{}",
272 ResolutionError::VariableBoundWithDifferentMode(variable_name,
274 first_binding_span) => {
275 let mut err = struct_span_err!(resolver.session,
278 "variable `{}` is bound with different mode in pattern #{} than in \
282 err.span_label(span, &format!("bound in different ways"));
283 err.span_label(first_binding_span, &format!("first binding"));
286 ResolutionError::SelfUsedOutsideImplOrTrait => {
287 let mut err = struct_span_err!(resolver.session,
290 "use of `Self` outside of an impl or trait");
291 err.span_label(span, &format!("used outside of impl or trait"));
294 ResolutionError::UseOfUndeclared(kind, name, candidates) => {
295 let mut err = struct_span_err!(resolver.session,
298 "{} `{}` is undefined or not in scope",
301 show_candidates(&mut err, &candidates);
302 err.span_label(span, &format!("undefined or not in scope"));
305 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
306 let mut err = struct_span_err!(resolver.session,
309 "identifier `{}` is bound more than once in this parameter list",
311 err.span_label(span, &format!("used as parameter more than once"));
314 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
315 let mut err = struct_span_err!(resolver.session,
318 "identifier `{}` is bound more than once in the same pattern",
320 err.span_label(span, &format!("used in a pattern more than once"));
323 ResolutionError::DoesNotNameAStruct(name) => {
324 let mut err = struct_span_err!(resolver.session,
327 "`{}` does not name a structure",
329 err.span_label(span, &format!("not a structure"));
332 ResolutionError::StructVariantUsedAsFunction(path_name) => {
333 struct_span_err!(resolver.session,
336 "`{}` is the name of a struct or struct variant, but this expression \
337 uses it like a function name",
340 ResolutionError::SelfNotAvailableInStaticMethod => {
341 struct_span_err!(resolver.session,
344 "`self` is not available in a static method. Maybe a `self` \
345 argument is missing?")
347 ResolutionError::UnresolvedName { path, message: msg, context, is_static_method,
349 let mut err = struct_span_err!(resolver.session,
352 "unresolved name `{}`{}",
356 UnresolvedNameContext::Other => {
357 if msg.is_empty() && is_static_method && is_field {
358 err.help("this is an associated function, you don't have access to \
359 this type's fields or methods");
362 UnresolvedNameContext::PathIsMod(parent) => {
363 err.help(&match parent.map(|parent| &parent.node) {
364 Some(&ExprKind::Field(_, ident)) => {
365 format!("to reference an item from the `{module}` module, \
366 use `{module}::{ident}`",
370 Some(&ExprKind::MethodCall(ident, _, _)) => {
371 format!("to call a function from the `{module}` module, \
372 use `{module}::{ident}(..)`",
377 format!("{def} `{module}` cannot be used as an expression",
378 def = def.kind_name(),
386 ResolutionError::UndeclaredLabel(name) => {
387 struct_span_err!(resolver.session,
390 "use of undeclared label `{}`",
393 ResolutionError::SelfImportsOnlyAllowedWithin => {
394 struct_span_err!(resolver.session,
398 "`self` imports are only allowed within a { } list")
400 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
401 struct_span_err!(resolver.session,
404 "`self` import can only appear once in the list")
406 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
407 struct_span_err!(resolver.session,
410 "`self` import can only appear in an import list with a \
413 ResolutionError::UnresolvedImport(name) => {
414 let msg = match name {
415 Some((n, p)) => format!("unresolved import `{}`{}", n, p),
416 None => "unresolved import".to_owned(),
418 struct_span_err!(resolver.session, span, E0432, "{}", msg)
420 ResolutionError::FailedToResolve(msg) => {
421 let mut err = struct_span_err!(resolver.session, span, E0433,
422 "failed to resolve. {}", msg);
423 err.span_label(span, &msg);
426 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
427 struct_span_err!(resolver.session,
431 "can't capture dynamic environment in a fn item; use the || { ... } \
432 closure form instead")
434 ResolutionError::AttemptToUseNonConstantValueInConstant => {
435 struct_span_err!(resolver.session,
438 "attempt to use a non-constant value in a constant")
440 ResolutionError::BindingShadowsSomethingUnacceptable(what_binding, name, binding) => {
441 let shadows_what = PathResolution::new(binding.def().unwrap()).kind_name();
442 let mut err = struct_span_err!(resolver.session,
445 "{}s cannot shadow {}s", what_binding, shadows_what);
446 err.span_label(span, &format!("cannot be named the same as a {}", shadows_what));
447 let participle = if binding.is_import() { "imported" } else { "defined" };
448 let msg = &format!("a {} `{}` is {} here", shadows_what, name, participle);
449 err.span_label(binding.span, msg);
452 ResolutionError::PatPathUnresolved(expected_what, path) => {
453 struct_span_err!(resolver.session,
456 "unresolved {} `{}`",
458 path.segments.last().unwrap().identifier)
460 ResolutionError::PatPathUnexpected(expected_what, found_what, path) => {
461 struct_span_err!(resolver.session,
464 "expected {}, found {} `{}`",
467 path.segments.last().unwrap().identifier)
472 #[derive(Copy, Clone)]
475 binding_mode: BindingMode,
478 // Map from the name in a pattern to its binding mode.
479 type BindingMap = HashMap<ast::Ident, BindingInfo>;
481 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
492 fn is_refutable(self) -> bool {
494 PatternSource::Match | PatternSource::IfLet | PatternSource::WhileLet => true,
495 PatternSource::Let | PatternSource::For | PatternSource::FnParam => false,
498 fn descr(self) -> &'static str {
500 PatternSource::Match => "match binding",
501 PatternSource::IfLet => "if let binding",
502 PatternSource::WhileLet => "while let binding",
503 PatternSource::Let => "let binding",
504 PatternSource::For => "for binding",
505 PatternSource::FnParam => "function parameter",
510 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
516 impl<'a> Visitor for Resolver<'a> {
517 fn visit_item(&mut self, item: &Item) {
518 self.resolve_item(item);
520 fn visit_arm(&mut self, arm: &Arm) {
521 self.resolve_arm(arm);
523 fn visit_block(&mut self, block: &Block) {
524 self.resolve_block(block);
526 fn visit_expr(&mut self, expr: &Expr) {
527 self.resolve_expr(expr, None);
529 fn visit_local(&mut self, local: &Local) {
530 self.resolve_local(local);
532 fn visit_ty(&mut self, ty: &Ty) {
533 self.resolve_type(ty);
535 fn visit_poly_trait_ref(&mut self, tref: &ast::PolyTraitRef, m: &ast::TraitBoundModifier) {
536 match self.resolve_trait_reference(tref.trait_ref.ref_id, &tref.trait_ref.path, 0) {
537 Ok(def) => self.record_def(tref.trait_ref.ref_id, def),
539 // error already reported
540 self.record_def(tref.trait_ref.ref_id, err_path_resolution())
543 visit::walk_poly_trait_ref(self, tref, m);
545 fn visit_variant(&mut self,
546 variant: &ast::Variant,
548 item_id: ast::NodeId) {
549 if let Some(ref dis_expr) = variant.node.disr_expr {
550 // resolve the discriminator expr as a constant
551 self.with_constant_rib(|this| {
552 this.visit_expr(dis_expr);
556 // `visit::walk_variant` without the discriminant expression.
557 self.visit_variant_data(&variant.node.data,
563 fn visit_foreign_item(&mut self, foreign_item: &ForeignItem) {
564 let type_parameters = match foreign_item.node {
565 ForeignItemKind::Fn(_, ref generics) => {
566 HasTypeParameters(generics, ItemRibKind)
568 ForeignItemKind::Static(..) => NoTypeParameters,
570 self.with_type_parameter_rib(type_parameters, |this| {
571 visit::walk_foreign_item(this, foreign_item);
574 fn visit_fn(&mut self,
575 function_kind: FnKind,
576 declaration: &FnDecl,
580 let rib_kind = match function_kind {
581 FnKind::ItemFn(_, generics, _, _, _, _) => {
582 self.visit_generics(generics);
585 FnKind::Method(_, sig, _) => {
586 self.visit_generics(&sig.generics);
587 MethodRibKind(!sig.decl.has_self())
589 FnKind::Closure => ClosureRibKind(node_id),
591 self.resolve_function(rib_kind, declaration, block);
595 pub type ErrorMessage = Option<(Span, String)>;
597 #[derive(Clone, PartialEq, Eq)]
598 pub enum ResolveResult<T> {
599 Failed(ErrorMessage), // Failed to resolve the name, optional helpful error message.
600 Indeterminate, // Couldn't determine due to unresolved globs.
601 Success(T), // Successfully resolved the import.
604 impl<T> ResolveResult<T> {
605 fn and_then<U, F: FnOnce(T) -> ResolveResult<U>>(self, f: F) -> ResolveResult<U> {
607 Failed(msg) => Failed(msg),
608 Indeterminate => Indeterminate,
613 fn success(self) -> Option<T> {
615 Success(t) => Some(t),
621 enum FallbackSuggestion {
628 #[derive(Copy, Clone)]
629 enum TypeParameters<'a, 'b> {
631 HasTypeParameters(// Type parameters.
634 // The kind of the rib used for type parameters.
638 // The rib kind controls the translation of local
639 // definitions (`Def::Local`) to upvars (`Def::Upvar`).
640 #[derive(Copy, Clone, Debug)]
642 // No translation needs to be applied.
645 // We passed through a closure scope at the given node ID.
646 // Translate upvars as appropriate.
647 ClosureRibKind(NodeId /* func id */),
649 // We passed through an impl or trait and are now in one of its
650 // methods. Allow references to ty params that impl or trait
651 // binds. Disallow any other upvars (including other ty params that are
654 // The boolean value represents the fact that this method is static or not.
657 // We passed through an item scope. Disallow upvars.
660 // We're in a constant item. Can't refer to dynamic stuff.
663 // We passed through a module.
664 ModuleRibKind(Module<'a>),
666 // We passed through a `macro_rules!` statement with the given expansion
667 MacroDefinition(Mark),
670 #[derive(Copy, Clone)]
671 enum UseLexicalScopeFlag {
676 enum ModulePrefixResult<'a> {
678 PrefixFound(Module<'a>, usize),
684 bindings: HashMap<ast::Ident, Def>,
689 fn new(kind: RibKind<'a>) -> Rib<'a> {
691 bindings: HashMap::new(),
697 /// A definition along with the index of the rib it was found on
699 ribs: Option<(Namespace, usize)>,
704 fn from_def(def: Def) -> Self {
712 enum LexicalScopeBinding<'a> {
713 Item(&'a NameBinding<'a>),
717 impl<'a> LexicalScopeBinding<'a> {
718 fn local_def(self) -> LocalDef {
720 LexicalScopeBinding::LocalDef(local_def) => local_def,
721 LexicalScopeBinding::Item(binding) => LocalDef::from_def(binding.def().unwrap()),
725 fn item(self) -> Option<&'a NameBinding<'a>> {
727 LexicalScopeBinding::Item(binding) => Some(binding),
732 fn module(self) -> Option<Module<'a>> {
733 self.item().and_then(NameBinding::module)
737 /// The link from a module up to its nearest parent node.
738 #[derive(Clone,Debug)]
739 enum ParentLink<'a> {
741 ModuleParentLink(Module<'a>, Name),
742 BlockParentLink(Module<'a>, NodeId),
745 /// One node in the tree of modules.
746 pub struct ModuleS<'a> {
747 parent_link: ParentLink<'a>,
750 // If the module is an extern crate, `def` is root of the external crate and `extern_crate_id`
751 // is the NodeId of the local `extern crate` item (otherwise, `extern_crate_id` is None).
752 extern_crate_id: Option<NodeId>,
754 resolutions: RefCell<HashMap<(Name, Namespace), &'a RefCell<NameResolution<'a>>>>,
756 no_implicit_prelude: Cell<bool>,
758 glob_importers: RefCell<Vec<&'a ImportDirective<'a>>>,
759 globs: RefCell<Vec<&'a ImportDirective<'a>>>,
761 // Used to memoize the traits in this module for faster searches through all traits in scope.
762 traits: RefCell<Option<Box<[(Name, &'a NameBinding<'a>)]>>>,
764 // Whether this module is populated. If not populated, any attempt to
765 // access the children must be preceded with a
766 // `populate_module_if_necessary` call.
767 populated: Cell<bool>,
770 pub type Module<'a> = &'a ModuleS<'a>;
772 impl<'a> ModuleS<'a> {
773 fn new(parent_link: ParentLink<'a>, def: Option<Def>, external: bool) -> Self {
775 parent_link: parent_link,
777 extern_crate_id: None,
778 resolutions: RefCell::new(HashMap::new()),
779 no_implicit_prelude: Cell::new(false),
780 glob_importers: RefCell::new(Vec::new()),
781 globs: RefCell::new((Vec::new())),
782 traits: RefCell::new(None),
783 populated: Cell::new(!external),
787 fn for_each_child<F: FnMut(Name, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
788 for (&(name, ns), name_resolution) in self.resolutions.borrow().iter() {
789 name_resolution.borrow().binding.map(|binding| f(name, ns, binding));
793 fn def_id(&self) -> Option<DefId> {
794 self.def.as_ref().map(Def::def_id)
797 // `self` resolves to the first module ancestor that `is_normal`.
798 fn is_normal(&self) -> bool {
800 Some(Def::Mod(_)) => true,
805 fn is_trait(&self) -> bool {
807 Some(Def::Trait(_)) => true,
813 impl<'a> fmt::Debug for ModuleS<'a> {
814 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
815 write!(f, "{:?}", self.def)
819 // Records a possibly-private value, type, or module definition.
820 #[derive(Clone, Debug)]
821 pub struct NameBinding<'a> {
822 kind: NameBindingKind<'a>,
827 pub trait ToNameBinding<'a> {
828 fn to_name_binding(self) -> NameBinding<'a>;
831 impl<'a> ToNameBinding<'a> for NameBinding<'a> {
832 fn to_name_binding(self) -> NameBinding<'a> {
837 #[derive(Clone, Debug)]
838 enum NameBindingKind<'a> {
842 binding: &'a NameBinding<'a>,
843 directive: &'a ImportDirective<'a>,
847 #[derive(Clone, Debug)]
848 struct PrivacyError<'a>(Span, Name, &'a NameBinding<'a>);
850 impl<'a> NameBinding<'a> {
851 fn module(&self) -> Option<Module<'a>> {
853 NameBindingKind::Module(module) => Some(module),
854 NameBindingKind::Def(_) => None,
855 NameBindingKind::Import { binding, .. } => binding.module(),
859 fn def(&self) -> Option<Def> {
861 NameBindingKind::Def(def) => Some(def),
862 NameBindingKind::Module(module) => module.def,
863 NameBindingKind::Import { binding, .. } => binding.def(),
867 fn is_pseudo_public(&self) -> bool {
868 self.pseudo_vis() == ty::Visibility::Public
871 // We sometimes need to treat variants as `pub` for backwards compatibility
872 fn pseudo_vis(&self) -> ty::Visibility {
873 if self.is_variant() { ty::Visibility::Public } else { self.vis }
876 fn is_variant(&self) -> bool {
878 NameBindingKind::Def(Def::Variant(..)) => true,
883 fn is_extern_crate(&self) -> bool {
884 self.module().and_then(|module| module.extern_crate_id).is_some()
887 fn is_import(&self) -> bool {
889 NameBindingKind::Import { .. } => true,
894 fn is_glob_import(&self) -> bool {
896 NameBindingKind::Import { directive, .. } => directive.is_glob(),
901 fn is_importable(&self) -> bool {
902 match self.def().unwrap() {
903 Def::AssociatedConst(..) | Def::Method(..) | Def::AssociatedTy(..) => false,
909 /// Interns the names of the primitive types.
910 struct PrimitiveTypeTable {
911 primitive_types: HashMap<Name, PrimTy>,
914 impl PrimitiveTypeTable {
915 fn new() -> PrimitiveTypeTable {
916 let mut table = PrimitiveTypeTable { primitive_types: HashMap::new() };
918 table.intern("bool", TyBool);
919 table.intern("char", TyChar);
920 table.intern("f32", TyFloat(FloatTy::F32));
921 table.intern("f64", TyFloat(FloatTy::F64));
922 table.intern("isize", TyInt(IntTy::Is));
923 table.intern("i8", TyInt(IntTy::I8));
924 table.intern("i16", TyInt(IntTy::I16));
925 table.intern("i32", TyInt(IntTy::I32));
926 table.intern("i64", TyInt(IntTy::I64));
927 table.intern("str", TyStr);
928 table.intern("usize", TyUint(UintTy::Us));
929 table.intern("u8", TyUint(UintTy::U8));
930 table.intern("u16", TyUint(UintTy::U16));
931 table.intern("u32", TyUint(UintTy::U32));
932 table.intern("u64", TyUint(UintTy::U64));
937 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
938 self.primitive_types.insert(token::intern(string), primitive_type);
942 /// The main resolver class.
943 pub struct Resolver<'a> {
944 session: &'a Session,
946 pub definitions: Definitions,
948 // Maps the node id of a statement to the expansions of the `macro_rules!`s
949 // immediately above the statement (if appropriate).
950 macros_at_scope: HashMap<NodeId, Vec<Mark>>,
952 graph_root: Module<'a>,
954 prelude: Option<Module<'a>>,
956 trait_item_map: FnvHashMap<(Name, DefId), bool /* is static method? */>,
958 structs: FnvHashMap<DefId, Vec<Name>>,
960 // All indeterminate imports (i.e. imports not known to succeed or fail).
961 indeterminate_imports: Vec<&'a ImportDirective<'a>>,
963 // The module that represents the current item scope.
964 current_module: Module<'a>,
966 // The visibility of `pub(self)` items in the current scope.
967 // Equivalently, the visibility required for an item to be accessible from the current scope.
968 current_vis: ty::Visibility,
970 // The current set of local scopes, for values.
971 // FIXME #4948: Reuse ribs to avoid allocation.
972 value_ribs: Vec<Rib<'a>>,
974 // The current set of local scopes, for types.
975 type_ribs: Vec<Rib<'a>>,
977 // The current set of local scopes, for labels.
978 label_ribs: Vec<Rib<'a>>,
980 // The trait that the current context can refer to.
981 current_trait_ref: Option<(DefId, TraitRef)>,
983 // The current self type if inside an impl (used for better errors).
984 current_self_type: Option<Ty>,
986 // The idents for the primitive types.
987 primitive_type_table: PrimitiveTypeTable,
990 pub freevars: FreevarMap,
991 freevars_seen: NodeMap<NodeMap<usize>>,
992 pub export_map: ExportMap,
993 pub trait_map: TraitMap,
995 // A map from nodes to modules, both normal (`mod`) modules and anonymous modules.
996 // Anonymous modules are pseudo-modules that are implicitly created around items
997 // contained within blocks.
999 // For example, if we have this:
1007 // There will be an anonymous module created around `g` with the ID of the
1008 // entry block for `f`.
1009 module_map: NodeMap<Module<'a>>,
1011 // Whether or not to print error messages. Can be set to true
1012 // when getting additional info for error message suggestions,
1013 // so as to avoid printing duplicate errors
1016 pub make_glob_map: bool,
1017 // Maps imports to the names of items actually imported (this actually maps
1018 // all imports, but only glob imports are actually interesting).
1019 pub glob_map: GlobMap,
1021 used_imports: HashSet<(NodeId, Namespace)>,
1022 used_crates: HashSet<CrateNum>,
1023 pub maybe_unused_trait_imports: NodeSet,
1025 privacy_errors: Vec<PrivacyError<'a>>,
1027 arenas: &'a ResolverArenas<'a>,
1030 pub struct ResolverArenas<'a> {
1031 modules: arena::TypedArena<ModuleS<'a>>,
1032 local_modules: RefCell<Vec<Module<'a>>>,
1033 name_bindings: arena::TypedArena<NameBinding<'a>>,
1034 import_directives: arena::TypedArena<ImportDirective<'a>>,
1035 name_resolutions: arena::TypedArena<RefCell<NameResolution<'a>>>,
1038 impl<'a> ResolverArenas<'a> {
1039 fn alloc_module(&'a self, module: ModuleS<'a>) -> Module<'a> {
1040 let module = self.modules.alloc(module);
1041 if module.def_id().map(|def_id| def_id.is_local()).unwrap_or(true) {
1042 self.local_modules.borrow_mut().push(module);
1046 fn local_modules(&'a self) -> ::std::cell::Ref<'a, Vec<Module<'a>>> {
1047 self.local_modules.borrow()
1049 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1050 self.name_bindings.alloc(name_binding)
1052 fn alloc_import_directive(&'a self, import_directive: ImportDirective<'a>)
1053 -> &'a ImportDirective {
1054 self.import_directives.alloc(import_directive)
1056 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1057 self.name_resolutions.alloc(Default::default())
1061 impl<'a> ty::NodeIdTree for Resolver<'a> {
1062 fn is_descendant_of(&self, node: NodeId, ancestor: NodeId) -> bool {
1063 let ancestor = self.definitions.local_def_id(ancestor);
1064 let mut module = *self.module_map.get(&node).unwrap();
1065 while module.def_id() != Some(ancestor) {
1066 let module_parent = match self.get_nearest_normal_module_parent(module) {
1067 Some(parent) => parent,
1068 None => return false,
1070 module = module_parent;
1076 impl<'a> hir::lowering::Resolver for Resolver<'a> {
1077 fn resolve_generated_global_path(&mut self, path: &hir::Path, is_value: bool) -> Def {
1078 let namespace = if is_value { ValueNS } else { TypeNS };
1079 match self.resolve_crate_relative_path(path.span, &path.segments, namespace) {
1080 Ok(binding) => binding.def().unwrap(),
1081 Err(true) => Def::Err,
1083 let path_name = &format!("{}", path);
1085 ResolutionError::UnresolvedName {
1088 context: UnresolvedNameContext::Other,
1089 is_static_method: false,
1093 resolve_error(self, path.span, error);
1099 fn get_resolution(&mut self, id: NodeId) -> Option<PathResolution> {
1100 self.def_map.get(&id).cloned()
1103 fn record_resolution(&mut self, id: NodeId, def: Def) {
1104 self.def_map.insert(id, PathResolution::new(def));
1107 fn definitions(&mut self) -> Option<&mut Definitions> {
1108 Some(&mut self.definitions)
1113 fn name(&self) -> Name;
1116 impl Named for ast::PathSegment {
1117 fn name(&self) -> Name {
1118 self.identifier.name
1122 impl Named for hir::PathSegment {
1123 fn name(&self) -> Name {
1128 impl<'a> Resolver<'a> {
1129 pub fn new(session: &'a Session, make_glob_map: MakeGlobMap, arenas: &'a ResolverArenas<'a>)
1131 let root_def_id = DefId::local(CRATE_DEF_INDEX);
1133 ModuleS::new(NoParentLink, Some(Def::Mod(root_def_id)), false);
1134 let graph_root = arenas.alloc_module(graph_root);
1135 let mut module_map = NodeMap();
1136 module_map.insert(CRATE_NODE_ID, graph_root);
1141 definitions: Definitions::new(),
1142 macros_at_scope: HashMap::new(),
1144 // The outermost module has def ID 0; this is not reflected in the
1146 graph_root: graph_root,
1149 trait_item_map: FnvHashMap(),
1150 structs: FnvHashMap(),
1152 indeterminate_imports: Vec::new(),
1154 current_module: graph_root,
1155 current_vis: ty::Visibility::Restricted(ast::CRATE_NODE_ID),
1156 value_ribs: vec![Rib::new(ModuleRibKind(graph_root))],
1157 type_ribs: vec![Rib::new(ModuleRibKind(graph_root))],
1158 label_ribs: Vec::new(),
1160 current_trait_ref: None,
1161 current_self_type: None,
1163 primitive_type_table: PrimitiveTypeTable::new(),
1166 freevars: NodeMap(),
1167 freevars_seen: NodeMap(),
1168 export_map: NodeMap(),
1169 trait_map: NodeMap(),
1170 module_map: module_map,
1173 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1174 glob_map: NodeMap(),
1176 used_imports: HashSet::new(),
1177 used_crates: HashSet::new(),
1178 maybe_unused_trait_imports: NodeSet(),
1180 privacy_errors: Vec::new(),
1186 pub fn arenas() -> ResolverArenas<'a> {
1188 modules: arena::TypedArena::new(),
1189 local_modules: RefCell::new(Vec::new()),
1190 name_bindings: arena::TypedArena::new(),
1191 import_directives: arena::TypedArena::new(),
1192 name_resolutions: arena::TypedArena::new(),
1196 /// Entry point to crate resolution.
1197 pub fn resolve_crate(&mut self, krate: &Crate) {
1198 self.current_module = self.graph_root;
1199 self.current_vis = ty::Visibility::Restricted(ast::CRATE_NODE_ID);
1200 visit::walk_crate(self, krate);
1202 check_unused::check_crate(self, krate);
1203 self.report_privacy_errors();
1206 fn new_module(&self, parent_link: ParentLink<'a>, def: Option<Def>, external: bool)
1208 self.arenas.alloc_module(ModuleS::new(parent_link, def, external))
1211 fn new_extern_crate_module(&self, parent_link: ParentLink<'a>, def: Def, local_node_id: NodeId)
1213 let mut module = ModuleS::new(parent_link, Some(def), false);
1214 module.extern_crate_id = Some(local_node_id);
1215 self.arenas.modules.alloc(module)
1218 fn get_ribs<'b>(&'b mut self, ns: Namespace) -> &'b mut Vec<Rib<'a>> {
1219 match ns { ValueNS => &mut self.value_ribs, TypeNS => &mut self.type_ribs }
1222 fn record_use(&mut self, name: Name, ns: Namespace, binding: &'a NameBinding<'a>) {
1223 // track extern crates for unused_extern_crate lint
1224 if let Some(DefId { krate, .. }) = binding.module().and_then(ModuleS::def_id) {
1225 self.used_crates.insert(krate);
1228 if let NameBindingKind::Import { directive, .. } = binding.kind {
1229 self.used_imports.insert((directive.id, ns));
1230 self.add_to_glob_map(directive.id, name);
1234 fn add_to_glob_map(&mut self, id: NodeId, name: Name) {
1235 if self.make_glob_map {
1236 self.glob_map.entry(id).or_insert_with(FnvHashSet).insert(name);
1240 /// Resolves the given module path from the given root `search_module`.
1241 fn resolve_module_path_from_root(&mut self,
1242 mut search_module: Module<'a>,
1243 module_path: &[Name],
1246 -> ResolveResult<Module<'a>> {
1247 fn search_parent_externals<'a>(this: &mut Resolver<'a>, needle: Name, module: Module<'a>)
1248 -> Option<Module<'a>> {
1249 match this.resolve_name_in_module(module, needle, TypeNS, false, None) {
1250 Success(binding) if binding.is_extern_crate() => Some(module),
1251 _ => match module.parent_link {
1252 ModuleParentLink(ref parent, _) => {
1253 search_parent_externals(this, needle, parent)
1260 let mut index = index;
1261 let module_path_len = module_path.len();
1263 // Resolve the module part of the path. This does not involve looking
1264 // upward though scope chains; we simply resolve names directly in
1265 // modules as we go.
1266 while index < module_path_len {
1267 let name = module_path[index];
1268 match self.resolve_name_in_module(search_module, name, TypeNS, false, span) {
1270 let segment_name = name.as_str();
1271 let module_name = module_to_string(search_module);
1272 let msg = if "???" == &module_name {
1273 let current_module = self.current_module;
1274 match search_parent_externals(self, name, current_module) {
1276 let path_str = names_to_string(module_path);
1277 let target_mod_str = module_to_string(&module);
1278 let current_mod_str = module_to_string(current_module);
1280 let prefix = if target_mod_str == current_mod_str {
1281 "self::".to_string()
1283 format!("{}::", target_mod_str)
1286 format!("Did you mean `{}{}`?", prefix, path_str)
1288 None => format!("Maybe a missing `extern crate {}`?", segment_name),
1291 format!("Could not find `{}` in `{}`", segment_name, module_name)
1294 return Failed(span.map(|span| (span, msg)));
1296 Failed(err) => return Failed(err),
1298 debug!("(resolving module path for import) module resolution is \
1301 return Indeterminate;
1303 Success(binding) => {
1304 // Check to see whether there are type bindings, and, if
1305 // so, whether there is a module within.
1306 if let Some(module_def) = binding.module() {
1307 search_module = module_def;
1309 let msg = format!("Not a module `{}`", name);
1310 return Failed(span.map(|span| (span, msg)));
1318 return Success(search_module);
1321 /// Attempts to resolve the module part of an import directive or path
1322 /// rooted at the given module.
1323 fn resolve_module_path(&mut self,
1324 module_path: &[Name],
1325 use_lexical_scope: UseLexicalScopeFlag,
1327 -> ResolveResult<Module<'a>> {
1328 if module_path.len() == 0 {
1329 return Success(self.graph_root) // Use the crate root
1332 debug!("(resolving module path for import) processing `{}` rooted at `{}`",
1333 names_to_string(module_path),
1334 module_to_string(self.current_module));
1336 // Resolve the module prefix, if any.
1337 let module_prefix_result = self.resolve_module_prefix(module_path, span);
1341 match module_prefix_result {
1342 Failed(err) => return Failed(err),
1344 debug!("(resolving module path for import) indeterminate; bailing");
1345 return Indeterminate;
1347 Success(NoPrefixFound) => {
1348 // There was no prefix, so we're considering the first element
1349 // of the path. How we handle this depends on whether we were
1350 // instructed to use lexical scope or not.
1351 match use_lexical_scope {
1352 DontUseLexicalScope => {
1353 // This is a crate-relative path. We will start the
1354 // resolution process at index zero.
1355 search_module = self.graph_root;
1358 UseLexicalScope => {
1359 // This is not a crate-relative path. We resolve the
1360 // first component of the path in the current lexical
1361 // scope and then proceed to resolve below that.
1362 let ident = ast::Ident::with_empty_ctxt(module_path[0]);
1363 match self.resolve_ident_in_lexical_scope(ident, TypeNS, span)
1364 .and_then(LexicalScopeBinding::module) {
1365 None => return Failed(None),
1366 Some(containing_module) => {
1367 search_module = containing_module;
1374 Success(PrefixFound(ref containing_module, index)) => {
1375 search_module = containing_module;
1376 start_index = index;
1380 self.resolve_module_path_from_root(search_module, module_path, start_index, span)
1383 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1384 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1385 /// `ident` in the first scope that defines it (or None if no scopes define it).
1387 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1388 /// the items are defined in the block. For example,
1391 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1394 /// g(); // This resolves to the local variable `g` since it shadows the item.
1398 /// Invariant: This must only be called during main resolution, not during
1399 /// import resolution.
1400 fn resolve_ident_in_lexical_scope(&mut self,
1401 mut ident: ast::Ident,
1403 record_used: Option<Span>)
1404 -> Option<LexicalScopeBinding<'a>> {
1406 ident = ast::Ident::with_empty_ctxt(ident.name);
1409 // Walk backwards up the ribs in scope.
1410 for i in (0 .. self.get_ribs(ns).len()).rev() {
1411 if let Some(def) = self.get_ribs(ns)[i].bindings.get(&ident).cloned() {
1412 // The ident resolves to a type parameter or local variable.
1413 return Some(LexicalScopeBinding::LocalDef(LocalDef {
1414 ribs: Some((ns, i)),
1419 if let ModuleRibKind(module) = self.get_ribs(ns)[i].kind {
1420 let name = ident.name;
1421 let item = self.resolve_name_in_module(module, name, ns, true, record_used);
1422 if let Success(binding) = item {
1423 // The ident resolves to an item.
1424 return Some(LexicalScopeBinding::Item(binding));
1427 // We can only see through anonymous modules
1428 if module.def.is_some() {
1429 return match self.prelude {
1430 Some(prelude) if !module.no_implicit_prelude.get() => {
1431 self.resolve_name_in_module(prelude, name, ns, false, None).success()
1432 .map(LexicalScopeBinding::Item)
1439 if let MacroDefinition(mac) = self.get_ribs(ns)[i].kind {
1440 // If an invocation of this macro created `ident`, give up on `ident`
1441 // and switch to `ident`'s source from the macro definition.
1442 let (source_ctxt, source_macro) = ident.ctxt.source();
1443 if source_macro == mac {
1444 ident.ctxt = source_ctxt;
1452 /// Returns the nearest normal module parent of the given module.
1453 fn get_nearest_normal_module_parent(&self, mut module: Module<'a>) -> Option<Module<'a>> {
1455 match module.parent_link {
1456 NoParentLink => return None,
1457 ModuleParentLink(new_module, _) |
1458 BlockParentLink(new_module, _) => {
1459 let new_module = new_module;
1460 if new_module.is_normal() {
1461 return Some(new_module);
1463 module = new_module;
1469 /// Returns the nearest normal module parent of the given module, or the
1470 /// module itself if it is a normal module.
1471 fn get_nearest_normal_module_parent_or_self(&self, module: Module<'a>) -> Module<'a> {
1472 if module.is_normal() {
1475 match self.get_nearest_normal_module_parent(module) {
1477 Some(new_module) => new_module,
1481 /// Resolves a "module prefix". A module prefix is one or both of (a) `self::`;
1482 /// (b) some chain of `super::`.
1483 /// grammar: (SELF MOD_SEP ) ? (SUPER MOD_SEP) *
1484 fn resolve_module_prefix(&mut self, module_path: &[Name], span: Option<Span>)
1485 -> ResolveResult<ModulePrefixResult<'a>> {
1486 // Start at the current module if we see `self` or `super`, or at the
1487 // top of the crate otherwise.
1488 let mut i = match &*module_path[0].as_str() {
1491 _ => return Success(NoPrefixFound),
1493 let mut containing_module =
1494 self.get_nearest_normal_module_parent_or_self(self.current_module);
1496 // Now loop through all the `super`s we find.
1497 while i < module_path.len() && "super" == module_path[i].as_str() {
1498 debug!("(resolving module prefix) resolving `super` at {}",
1499 module_to_string(&containing_module));
1500 match self.get_nearest_normal_module_parent(containing_module) {
1502 let msg = "There are too many initial `super`s.".into();
1503 return Failed(span.map(|span| (span, msg)));
1505 Some(new_module) => {
1506 containing_module = new_module;
1512 debug!("(resolving module prefix) finished resolving prefix at {}",
1513 module_to_string(&containing_module));
1515 return Success(PrefixFound(containing_module, i));
1520 // We maintain a list of value ribs and type ribs.
1522 // Simultaneously, we keep track of the current position in the module
1523 // graph in the `current_module` pointer. When we go to resolve a name in
1524 // the value or type namespaces, we first look through all the ribs and
1525 // then query the module graph. When we resolve a name in the module
1526 // namespace, we can skip all the ribs (since nested modules are not
1527 // allowed within blocks in Rust) and jump straight to the current module
1530 // Named implementations are handled separately. When we find a method
1531 // call, we consult the module node to find all of the implementations in
1532 // scope. This information is lazily cached in the module node. We then
1533 // generate a fake "implementation scope" containing all the
1534 // implementations thus found, for compatibility with old resolve pass.
1536 fn with_scope<F>(&mut self, id: NodeId, f: F)
1537 where F: FnOnce(&mut Resolver)
1539 let module = self.module_map.get(&id).cloned(); // clones a reference
1540 if let Some(module) = module {
1541 // Move down in the graph.
1542 let orig_module = replace(&mut self.current_module, module);
1543 let orig_vis = replace(&mut self.current_vis, ty::Visibility::Restricted(id));
1544 self.value_ribs.push(Rib::new(ModuleRibKind(module)));
1545 self.type_ribs.push(Rib::new(ModuleRibKind(module)));
1549 self.current_module = orig_module;
1550 self.current_vis = orig_vis;
1551 self.value_ribs.pop();
1552 self.type_ribs.pop();
1558 /// Searches the current set of local scopes for labels.
1559 /// Stops after meeting a closure.
1560 fn search_label(&self, mut ident: ast::Ident) -> Option<Def> {
1561 for rib in self.label_ribs.iter().rev() {
1566 MacroDefinition(mac) => {
1567 // If an invocation of this macro created `ident`, give up on `ident`
1568 // and switch to `ident`'s source from the macro definition.
1569 let (source_ctxt, source_macro) = ident.ctxt.source();
1570 if source_macro == mac {
1571 ident.ctxt = source_ctxt;
1575 // Do not resolve labels across function boundary
1579 let result = rib.bindings.get(&ident).cloned();
1580 if result.is_some() {
1587 fn resolve_item(&mut self, item: &Item) {
1588 let name = item.ident.name;
1590 debug!("(resolving item) resolving {}", name);
1593 ItemKind::Enum(_, ref generics) |
1594 ItemKind::Ty(_, ref generics) |
1595 ItemKind::Struct(_, ref generics) |
1596 ItemKind::Fn(_, _, _, _, ref generics, _) => {
1597 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind),
1598 |this| visit::walk_item(this, item));
1601 ItemKind::DefaultImpl(_, ref trait_ref) => {
1602 self.with_optional_trait_ref(Some(trait_ref), |_, _| {});
1604 ItemKind::Impl(_, _, ref generics, ref opt_trait_ref, ref self_type, ref impl_items) =>
1605 self.resolve_implementation(generics,
1611 ItemKind::Trait(_, ref generics, ref bounds, ref trait_items) => {
1612 // Create a new rib for the trait-wide type parameters.
1613 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
1614 let local_def_id = this.definitions.local_def_id(item.id);
1615 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
1616 this.visit_generics(generics);
1617 walk_list!(this, visit_ty_param_bound, bounds);
1619 for trait_item in trait_items {
1620 match trait_item.node {
1621 TraitItemKind::Const(_, ref default) => {
1622 // Only impose the restrictions of
1623 // ConstRibKind if there's an actual constant
1624 // expression in a provided default.
1625 if default.is_some() {
1626 this.with_constant_rib(|this| {
1627 visit::walk_trait_item(this, trait_item)
1630 visit::walk_trait_item(this, trait_item)
1633 TraitItemKind::Method(ref sig, _) => {
1634 let type_parameters =
1635 HasTypeParameters(&sig.generics,
1636 MethodRibKind(!sig.decl.has_self()));
1637 this.with_type_parameter_rib(type_parameters, |this| {
1638 visit::walk_trait_item(this, trait_item)
1641 TraitItemKind::Type(..) => {
1642 this.with_type_parameter_rib(NoTypeParameters, |this| {
1643 visit::walk_trait_item(this, trait_item)
1646 TraitItemKind::Macro(_) => panic!("unexpanded macro in resolve!"),
1653 ItemKind::Mod(_) | ItemKind::ForeignMod(_) => {
1654 self.with_scope(item.id, |this| {
1655 visit::walk_item(this, item);
1659 ItemKind::Const(..) | ItemKind::Static(..) => {
1660 self.with_constant_rib(|this| {
1661 visit::walk_item(this, item);
1665 ItemKind::Use(ref view_path) => {
1666 match view_path.node {
1667 ast::ViewPathList(ref prefix, ref items) => {
1668 // Resolve prefix of an import with empty braces (issue #28388)
1669 if items.is_empty() && !prefix.segments.is_empty() {
1670 match self.resolve_crate_relative_path(prefix.span,
1674 let def = binding.def().unwrap();
1675 self.record_def(item.id, PathResolution::new(def));
1677 Err(true) => self.record_def(item.id, err_path_resolution()),
1681 ResolutionError::FailedToResolve(
1682 &path_names_to_string(prefix, 0)));
1683 self.record_def(item.id, err_path_resolution());
1692 ItemKind::ExternCrate(_) => {
1693 // do nothing, these are just around to be encoded
1696 ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"),
1700 fn with_type_parameter_rib<'b, F>(&'b mut self, type_parameters: TypeParameters<'a, 'b>, f: F)
1701 where F: FnOnce(&mut Resolver)
1703 match type_parameters {
1704 HasTypeParameters(generics, rib_kind) => {
1705 let mut function_type_rib = Rib::new(rib_kind);
1706 let mut seen_bindings = HashSet::new();
1707 for type_parameter in &generics.ty_params {
1708 let name = type_parameter.ident.name;
1709 debug!("with_type_parameter_rib: {}", type_parameter.id);
1711 if seen_bindings.contains(&name) {
1713 type_parameter.span,
1714 ResolutionError::NameAlreadyUsedInTypeParameterList(name));
1716 seen_bindings.insert(name);
1718 // plain insert (no renaming)
1719 let def_id = self.definitions.local_def_id(type_parameter.id);
1720 let def = Def::TyParam(def_id);
1721 function_type_rib.bindings.insert(ast::Ident::with_empty_ctxt(name), def);
1722 self.record_def(type_parameter.id, PathResolution::new(def));
1724 self.type_ribs.push(function_type_rib);
1727 NoTypeParameters => {
1734 if let HasTypeParameters(..) = type_parameters {
1735 self.type_ribs.pop();
1739 fn with_label_rib<F>(&mut self, f: F)
1740 where F: FnOnce(&mut Resolver)
1742 self.label_ribs.push(Rib::new(NormalRibKind));
1744 self.label_ribs.pop();
1747 fn with_constant_rib<F>(&mut self, f: F)
1748 where F: FnOnce(&mut Resolver)
1750 self.value_ribs.push(Rib::new(ConstantItemRibKind));
1751 self.type_ribs.push(Rib::new(ConstantItemRibKind));
1753 self.type_ribs.pop();
1754 self.value_ribs.pop();
1757 fn resolve_function(&mut self,
1758 rib_kind: RibKind<'a>,
1759 declaration: &FnDecl,
1761 // Create a value rib for the function.
1762 self.value_ribs.push(Rib::new(rib_kind));
1764 // Create a label rib for the function.
1765 self.label_ribs.push(Rib::new(rib_kind));
1767 // Add each argument to the rib.
1768 let mut bindings_list = HashMap::new();
1769 for argument in &declaration.inputs {
1770 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
1772 self.visit_ty(&argument.ty);
1774 debug!("(resolving function) recorded argument");
1776 visit::walk_fn_ret_ty(self, &declaration.output);
1778 // Resolve the function body.
1779 self.visit_block(block);
1781 debug!("(resolving function) leaving function");
1783 self.label_ribs.pop();
1784 self.value_ribs.pop();
1787 fn resolve_trait_reference(&mut self,
1791 -> Result<PathResolution, ()> {
1792 self.resolve_path(id, trait_path, path_depth, TypeNS).and_then(|path_res| {
1793 match path_res.base_def {
1795 debug!("(resolving trait) found trait def: {:?}", path_res);
1796 return Ok(path_res);
1798 Def::Err => return Err(true),
1802 let mut err = resolve_struct_error(self, trait_path.span, {
1803 ResolutionError::IsNotATrait(&path_names_to_string(trait_path, path_depth))
1806 // If it's a typedef, give a note
1807 if let Def::TyAlias(..) = path_res.base_def {
1808 err.note(&format!("type aliases cannot be used for traits"));
1812 }).map_err(|error_reported| {
1813 if error_reported { return }
1815 // find possible candidates
1816 let trait_name = trait_path.segments.last().unwrap().identifier.name;
1818 self.lookup_candidates(
1822 Def::Trait(_) => true,
1827 // create error object
1828 let name = &path_names_to_string(trait_path, path_depth);
1830 ResolutionError::UndeclaredTraitName(
1835 resolve_error(self, trait_path.span, error);
1839 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
1840 where F: FnOnce(&mut Resolver) -> T
1842 // Handle nested impls (inside fn bodies)
1843 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
1844 let result = f(self);
1845 self.current_self_type = previous_value;
1849 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
1850 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
1852 let mut new_val = None;
1853 let mut new_id = None;
1854 if let Some(trait_ref) = opt_trait_ref {
1855 if let Ok(path_res) = self.resolve_trait_reference(trait_ref.ref_id,
1858 assert!(path_res.depth == 0);
1859 self.record_def(trait_ref.ref_id, path_res);
1860 new_val = Some((path_res.base_def.def_id(), trait_ref.clone()));
1861 new_id = Some(path_res.base_def.def_id());
1863 self.record_def(trait_ref.ref_id, err_path_resolution());
1865 visit::walk_trait_ref(self, trait_ref);
1867 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
1868 let result = f(self, new_id);
1869 self.current_trait_ref = original_trait_ref;
1873 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
1874 where F: FnOnce(&mut Resolver)
1876 let mut self_type_rib = Rib::new(NormalRibKind);
1878 // plain insert (no renaming, types are not currently hygienic....)
1879 self_type_rib.bindings.insert(keywords::SelfType.ident(), self_def);
1880 self.type_ribs.push(self_type_rib);
1882 self.type_ribs.pop();
1885 fn resolve_implementation(&mut self,
1886 generics: &Generics,
1887 opt_trait_reference: &Option<TraitRef>,
1890 impl_items: &[ImplItem]) {
1891 // If applicable, create a rib for the type parameters.
1892 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
1893 // Resolve the type parameters.
1894 this.visit_generics(generics);
1896 // Resolve the trait reference, if necessary.
1897 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
1898 // Resolve the self type.
1899 this.visit_ty(self_type);
1901 this.with_self_rib(Def::SelfTy(trait_id, Some(item_id)), |this| {
1902 this.with_current_self_type(self_type, |this| {
1903 for impl_item in impl_items {
1904 this.resolve_visibility(&impl_item.vis);
1905 match impl_item.node {
1906 ImplItemKind::Const(..) => {
1907 // If this is a trait impl, ensure the const
1909 this.check_trait_item(impl_item.ident.name,
1911 |n, s| ResolutionError::ConstNotMemberOfTrait(n, s));
1912 visit::walk_impl_item(this, impl_item);
1914 ImplItemKind::Method(ref sig, _) => {
1915 // If this is a trait impl, ensure the method
1917 this.check_trait_item(impl_item.ident.name,
1919 |n, s| ResolutionError::MethodNotMemberOfTrait(n, s));
1921 // We also need a new scope for the method-
1922 // specific type parameters.
1923 let type_parameters =
1924 HasTypeParameters(&sig.generics,
1925 MethodRibKind(!sig.decl.has_self()));
1926 this.with_type_parameter_rib(type_parameters, |this| {
1927 visit::walk_impl_item(this, impl_item);
1930 ImplItemKind::Type(ref ty) => {
1931 // If this is a trait impl, ensure the type
1933 this.check_trait_item(impl_item.ident.name,
1935 |n, s| ResolutionError::TypeNotMemberOfTrait(n, s));
1939 ImplItemKind::Macro(_) => panic!("unexpanded macro in resolve!"),
1948 fn check_trait_item<F>(&self, name: Name, span: Span, err: F)
1949 where F: FnOnce(Name, &str) -> ResolutionError
1951 // If there is a TraitRef in scope for an impl, then the method must be in the
1953 if let Some((did, ref trait_ref)) = self.current_trait_ref {
1954 if !self.trait_item_map.contains_key(&(name, did)) {
1955 let path_str = path_names_to_string(&trait_ref.path, 0);
1956 resolve_error(self, span, err(name, &path_str));
1961 fn resolve_local(&mut self, local: &Local) {
1962 // Resolve the type.
1963 walk_list!(self, visit_ty, &local.ty);
1965 // Resolve the initializer.
1966 walk_list!(self, visit_expr, &local.init);
1968 // Resolve the pattern.
1969 self.resolve_pattern(&local.pat, PatternSource::Let, &mut HashMap::new());
1972 // build a map from pattern identifiers to binding-info's.
1973 // this is done hygienically. This could arise for a macro
1974 // that expands into an or-pattern where one 'x' was from the
1975 // user and one 'x' came from the macro.
1976 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
1977 let mut binding_map = HashMap::new();
1979 pat.walk(&mut |pat| {
1980 if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node {
1981 if sub_pat.is_some() || match self.def_map.get(&pat.id) {
1982 Some(&PathResolution { base_def: Def::Local(..), .. }) => true,
1985 let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode };
1986 binding_map.insert(ident.node, binding_info);
1995 // check that all of the arms in an or-pattern have exactly the
1996 // same set of bindings, with the same binding modes for each.
1997 fn check_consistent_bindings(&mut self, arm: &Arm) {
1998 if arm.pats.is_empty() {
2001 let map_0 = self.binding_mode_map(&arm.pats[0]);
2002 for (i, p) in arm.pats.iter().enumerate() {
2003 let map_i = self.binding_mode_map(&p);
2005 for (&key, &binding_0) in &map_0 {
2006 match map_i.get(&key) {
2008 let error = ResolutionError::VariableNotBoundInPattern(key.name, 1, i + 1);
2009 resolve_error(self, p.span, error);
2011 Some(binding_i) => {
2012 if binding_0.binding_mode != binding_i.binding_mode {
2015 ResolutionError::VariableBoundWithDifferentMode(
2024 for (&key, &binding) in &map_i {
2025 if !map_0.contains_key(&key) {
2028 ResolutionError::VariableNotBoundInPattern(key.name, i + 1, 1));
2034 fn resolve_arm(&mut self, arm: &Arm) {
2035 self.value_ribs.push(Rib::new(NormalRibKind));
2037 let mut bindings_list = HashMap::new();
2038 for pattern in &arm.pats {
2039 self.resolve_pattern(&pattern, PatternSource::Match, &mut bindings_list);
2042 // This has to happen *after* we determine which
2043 // pat_idents are variants
2044 self.check_consistent_bindings(arm);
2046 walk_list!(self, visit_expr, &arm.guard);
2047 self.visit_expr(&arm.body);
2049 self.value_ribs.pop();
2052 fn resolve_block(&mut self, block: &Block) {
2053 debug!("(resolving block) entering block");
2054 // Move down in the graph, if there's an anonymous module rooted here.
2055 let orig_module = self.current_module;
2056 let anonymous_module = self.module_map.get(&block.id).cloned(); // clones a reference
2058 let mut num_macro_definition_ribs = 0;
2059 if let Some(anonymous_module) = anonymous_module {
2060 debug!("(resolving block) found anonymous module, moving down");
2061 self.value_ribs.push(Rib::new(ModuleRibKind(anonymous_module)));
2062 self.type_ribs.push(Rib::new(ModuleRibKind(anonymous_module)));
2063 self.current_module = anonymous_module;
2065 self.value_ribs.push(Rib::new(NormalRibKind));
2068 // Descend into the block.
2069 for stmt in &block.stmts {
2070 if let Some(marks) = self.macros_at_scope.remove(&stmt.id) {
2071 num_macro_definition_ribs += marks.len() as u32;
2073 self.value_ribs.push(Rib::new(MacroDefinition(mark)));
2074 self.label_ribs.push(Rib::new(MacroDefinition(mark)));
2078 self.visit_stmt(stmt);
2082 self.current_module = orig_module;
2083 for _ in 0 .. num_macro_definition_ribs {
2084 self.value_ribs.pop();
2085 self.label_ribs.pop();
2087 self.value_ribs.pop();
2088 if let Some(_) = anonymous_module {
2089 self.type_ribs.pop();
2091 debug!("(resolving block) leaving block");
2094 fn resolve_type(&mut self, ty: &Ty) {
2096 TyKind::Path(ref maybe_qself, ref path) => {
2097 // This is a path in the type namespace. Walk through scopes
2099 if let Some(def) = self.resolve_possibly_assoc_item(ty.id, maybe_qself.as_ref(),
2101 match def.base_def {
2102 Def::Mod(..) if def.depth == 0 => {
2103 self.session.span_err(path.span, "expected type, found module");
2104 self.record_def(ty.id, err_path_resolution());
2107 // Write the result into the def map.
2108 debug!("(resolving type) writing resolution for `{}` (id {}) = {:?}",
2109 path_names_to_string(path, 0), ty.id, def);
2110 self.record_def(ty.id, def);
2114 self.record_def(ty.id, err_path_resolution());
2116 // Keep reporting some errors even if they're ignored above.
2117 if let Err(true) = self.resolve_path(ty.id, path, 0, TypeNS) {
2118 // `resolve_path` already reported the error
2120 let kind = if maybe_qself.is_some() {
2126 let is_invalid_self_type_name = path.segments.len() > 0 &&
2127 maybe_qself.is_none() &&
2128 path.segments[0].identifier.name ==
2129 keywords::SelfType.name();
2130 if is_invalid_self_type_name {
2133 ResolutionError::SelfUsedOutsideImplOrTrait);
2135 let segment = path.segments.last();
2136 let segment = segment.expect("missing name in path");
2137 let type_name = segment.identifier.name;
2140 self.lookup_candidates(
2147 Def::TyAlias(_) => true,
2152 // create error object
2153 let name = &path_names_to_string(path, 0);
2155 ResolutionError::UseOfUndeclared(
2161 resolve_error(self, ty.span, error);
2168 // Resolve embedded types.
2169 visit::walk_ty(self, ty);
2172 fn fresh_binding(&mut self,
2173 ident: &ast::SpannedIdent,
2175 outer_pat_id: NodeId,
2176 pat_src: PatternSource,
2177 bindings: &mut HashMap<ast::Ident, NodeId>)
2179 // Add the binding to the local ribs, if it
2180 // doesn't already exist in the bindings map. (We
2181 // must not add it if it's in the bindings map
2182 // because that breaks the assumptions later
2183 // passes make about or-patterns.)
2184 let mut def = Def::Local(self.definitions.local_def_id(pat_id), pat_id);
2185 match bindings.get(&ident.node).cloned() {
2186 Some(id) if id == outer_pat_id => {
2187 // `Variant(a, a)`, error
2191 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2192 &ident.node.name.as_str())
2195 Some(..) if pat_src == PatternSource::FnParam => {
2196 // `fn f(a: u8, a: u8)`, error
2200 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2201 &ident.node.name.as_str())
2204 Some(..) if pat_src == PatternSource::Match => {
2205 // `Variant1(a) | Variant2(a)`, ok
2206 // Reuse definition from the first `a`.
2207 def = self.value_ribs.last_mut().unwrap().bindings[&ident.node];
2210 span_bug!(ident.span, "two bindings with the same name from \
2211 unexpected pattern source {:?}", pat_src);
2214 // A completely fresh binding, add to the lists if it's valid.
2215 if ident.node.name != keywords::Invalid.name() {
2216 bindings.insert(ident.node, outer_pat_id);
2217 self.value_ribs.last_mut().unwrap().bindings.insert(ident.node, def);
2222 PathResolution::new(def)
2225 fn resolve_pattern_path<ExpectedFn>(&mut self,
2227 qself: Option<&QSelf>,
2229 namespace: Namespace,
2230 expected_fn: ExpectedFn,
2231 expected_what: &str)
2232 where ExpectedFn: FnOnce(Def) -> bool
2234 let resolution = if let Some(resolution) = self.resolve_possibly_assoc_item(pat_id,
2235 qself, path, namespace) {
2236 if resolution.depth == 0 {
2237 if expected_fn(resolution.base_def) || resolution.base_def == Def::Err {
2243 ResolutionError::PatPathUnexpected(expected_what,
2244 resolution.kind_name(), path)
2246 err_path_resolution()
2249 // Not fully resolved associated item `T::A::B` or `<T as Tr>::A::B`
2250 // or `<T>::A::B`. If `B` should be resolved in value namespace then
2251 // it needs to be added to the trait map.
2252 if namespace == ValueNS {
2253 let item_name = path.segments.last().unwrap().identifier.name;
2254 let traits = self.get_traits_containing_item(item_name);
2255 self.trait_map.insert(pat_id, traits);
2260 if let Err(false) = self.resolve_path(pat_id, path, 0, namespace) {
2264 ResolutionError::PatPathUnresolved(expected_what, path)
2267 err_path_resolution()
2270 self.record_def(pat_id, resolution);
2273 fn resolve_pattern(&mut self,
2275 pat_src: PatternSource,
2276 // Maps idents to the node ID for the
2277 // outermost pattern that binds them.
2278 bindings: &mut HashMap<ast::Ident, NodeId>) {
2279 // Visit all direct subpatterns of this pattern.
2280 let outer_pat_id = pat.id;
2281 pat.walk(&mut |pat| {
2283 PatKind::Ident(bmode, ref ident, ref opt_pat) => {
2284 // First try to resolve the identifier as some existing
2285 // entity, then fall back to a fresh binding.
2286 let binding = self.resolve_ident_in_lexical_scope(ident.node, ValueNS, None)
2287 .and_then(LexicalScopeBinding::item);
2288 let resolution = binding.and_then(NameBinding::def).and_then(|def| {
2289 let always_binding = !pat_src.is_refutable() || opt_pat.is_some() ||
2290 bmode != BindingMode::ByValue(Mutability::Immutable);
2292 Def::Struct(..) | Def::Variant(..) |
2293 Def::Const(..) | Def::AssociatedConst(..) if !always_binding => {
2294 // A constant, unit variant, etc pattern.
2295 self.record_use(ident.node.name, ValueNS, binding.unwrap());
2296 Some(PathResolution::new(def))
2298 Def::Struct(..) | Def::Variant(..) |
2299 Def::Const(..) | Def::AssociatedConst(..) | Def::Static(..) => {
2300 // A fresh binding that shadows something unacceptable.
2304 ResolutionError::BindingShadowsSomethingUnacceptable(
2305 pat_src.descr(), ident.node.name, binding.unwrap())
2309 Def::Local(..) | Def::Upvar(..) | Def::Fn(..) | Def::Err => {
2310 // These entities are explicitly allowed
2311 // to be shadowed by fresh bindings.
2315 span_bug!(ident.span, "unexpected definition for an \
2316 identifier in pattern {:?}", def);
2319 }).unwrap_or_else(|| {
2320 self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings)
2323 self.record_def(pat.id, resolution);
2326 PatKind::TupleStruct(ref path, _, _) => {
2327 self.resolve_pattern_path(pat.id, None, path, ValueNS, |def| {
2329 Def::Struct(..) | Def::Variant(..) => true,
2332 }, "variant or struct");
2335 PatKind::Path(ref qself, ref path) => {
2336 self.resolve_pattern_path(pat.id, qself.as_ref(), path, ValueNS, |def| {
2338 Def::Struct(..) | Def::Variant(..) |
2339 Def::Const(..) | Def::AssociatedConst(..) => true,
2342 }, "variant, struct or constant");
2345 PatKind::Struct(ref path, _, _) => {
2346 self.resolve_pattern_path(pat.id, None, path, TypeNS, |def| {
2348 Def::Struct(..) | Def::Variant(..) |
2349 Def::TyAlias(..) | Def::AssociatedTy(..) => true,
2352 }, "variant, struct or type alias");
2360 visit::walk_pat(self, pat);
2363 /// Handles paths that may refer to associated items
2364 fn resolve_possibly_assoc_item(&mut self,
2366 maybe_qself: Option<&QSelf>,
2368 namespace: Namespace)
2369 -> Option<PathResolution> {
2370 let max_assoc_types;
2374 if qself.position == 0 {
2375 // FIXME: Create some fake resolution that can't possibly be a type.
2376 return Some(PathResolution {
2377 base_def: Def::Mod(self.definitions.local_def_id(ast::CRATE_NODE_ID)),
2378 depth: path.segments.len(),
2381 max_assoc_types = path.segments.len() - qself.position;
2382 // Make sure the trait is valid.
2383 let _ = self.resolve_trait_reference(id, path, max_assoc_types);
2386 max_assoc_types = path.segments.len();
2390 let mut resolution = self.with_no_errors(|this| {
2391 this.resolve_path(id, path, 0, namespace).ok()
2393 for depth in 1..max_assoc_types {
2394 if resolution.is_some() {
2397 self.with_no_errors(|this| {
2398 let partial_resolution = this.resolve_path(id, path, depth, TypeNS).ok();
2399 if let Some(Def::Mod(..)) = partial_resolution.map(|r| r.base_def) {
2400 // Modules cannot have associated items
2402 resolution = partial_resolution;
2409 /// Skips `path_depth` trailing segments, which is also reflected in the
2410 /// returned value. See `hir::def::PathResolution` for more info.
2411 fn resolve_path(&mut self, id: NodeId, path: &Path, path_depth: usize, namespace: Namespace)
2412 -> Result<PathResolution, bool /* true if an error was reported */ > {
2413 debug!("resolve_path(id={:?} path={:?}, path_depth={:?})", id, path, path_depth);
2415 let span = path.span;
2416 let segments = &path.segments[..path.segments.len() - path_depth];
2418 let mk_res = |def| PathResolution { base_def: def, depth: path_depth };
2421 let binding = self.resolve_crate_relative_path(span, segments, namespace);
2422 return binding.map(|binding| mk_res(binding.def().unwrap()));
2425 // Try to find a path to an item in a module.
2426 let last_ident = segments.last().unwrap().identifier;
2427 // Resolve a single identifier with fallback to primitive types
2428 let resolve_identifier_with_fallback = |this: &mut Self, record_used| {
2429 let def = this.resolve_identifier(last_ident, namespace, record_used);
2431 None | Some(LocalDef{def: Def::Mod(..), ..}) if namespace == TypeNS =>
2432 this.primitive_type_table
2434 .get(&last_ident.name)
2435 .map_or(def, |prim_ty| Some(LocalDef::from_def(Def::PrimTy(*prim_ty)))),
2440 if segments.len() == 1 {
2441 // In `a(::assoc_item)*` `a` cannot be a module. If `a` does resolve to a module we
2442 // don't report an error right away, but try to fallback to a primitive type.
2443 // So, we are still able to successfully resolve something like
2445 // use std::u8; // bring module u8 in scope
2446 // fn f() -> u8 { // OK, resolves to primitive u8, not to std::u8
2447 // u8::max_value() // OK, resolves to associated function <u8>::max_value,
2448 // // not to non-existent std::u8::max_value
2451 // Such behavior is required for backward compatibility.
2452 // The same fallback is used when `a` resolves to nothing.
2453 let def = resolve_identifier_with_fallback(self, Some(span)).ok_or(false);
2454 return def.and_then(|def| self.adjust_local_def(def, span).ok_or(true)).map(mk_res);
2457 let unqualified_def = resolve_identifier_with_fallback(self, None);
2458 let qualified_binding = self.resolve_module_relative_path(span, segments, namespace);
2459 match (qualified_binding, unqualified_def) {
2460 (Ok(binding), Some(ref ud)) if binding.def().unwrap() == ud.def => {
2462 .add_lint(lint::builtin::UNUSED_QUALIFICATIONS,
2465 "unnecessary qualification".to_string());
2470 qualified_binding.map(|binding| mk_res(binding.def().unwrap()))
2473 // Resolve a single identifier
2474 fn resolve_identifier(&mut self,
2475 identifier: ast::Ident,
2476 namespace: Namespace,
2477 record_used: Option<Span>)
2478 -> Option<LocalDef> {
2479 if identifier.name == keywords::Invalid.name() {
2483 self.resolve_ident_in_lexical_scope(identifier, namespace, record_used)
2484 .map(LexicalScopeBinding::local_def)
2487 // Resolve a local definition, potentially adjusting for closures.
2488 fn adjust_local_def(&mut self, local_def: LocalDef, span: Span) -> Option<Def> {
2489 let ribs = match local_def.ribs {
2490 Some((TypeNS, i)) => &self.type_ribs[i + 1..],
2491 Some((ValueNS, i)) => &self.value_ribs[i + 1..],
2494 let mut def = local_def.def;
2497 span_bug!(span, "unexpected {:?} in bindings", def)
2499 Def::Local(_, node_id) => {
2502 NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) => {
2503 // Nothing to do. Continue.
2505 ClosureRibKind(function_id) => {
2507 let node_def_id = self.definitions.local_def_id(node_id);
2509 let seen = self.freevars_seen
2511 .or_insert_with(|| NodeMap());
2512 if let Some(&index) = seen.get(&node_id) {
2513 def = Def::Upvar(node_def_id, node_id, index, function_id);
2516 let vec = self.freevars
2518 .or_insert_with(|| vec![]);
2519 let depth = vec.len();
2525 def = Def::Upvar(node_def_id, node_id, depth, function_id);
2526 seen.insert(node_id, depth);
2528 ItemRibKind | MethodRibKind(_) => {
2529 // This was an attempt to access an upvar inside a
2530 // named function item. This is not allowed, so we
2534 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
2537 ConstantItemRibKind => {
2538 // Still doesn't deal with upvars
2541 ResolutionError::AttemptToUseNonConstantValueInConstant);
2547 Def::TyParam(..) | Def::SelfTy(..) => {
2550 NormalRibKind | MethodRibKind(_) | ClosureRibKind(..) |
2551 ModuleRibKind(..) | MacroDefinition(..) => {
2552 // Nothing to do. Continue.
2555 // This was an attempt to use a type parameter outside
2560 ResolutionError::TypeParametersFromOuterFunction);
2563 ConstantItemRibKind => {
2565 resolve_error(self, span, ResolutionError::OuterTypeParameterContext);
2576 // resolve a "module-relative" path, e.g. a::b::c
2577 fn resolve_module_relative_path(&mut self,
2579 segments: &[ast::PathSegment],
2580 namespace: Namespace)
2581 -> Result<&'a NameBinding<'a>,
2582 bool /* true if an error was reported */> {
2583 let module_path = segments.split_last()
2587 .map(|ps| ps.identifier.name)
2588 .collect::<Vec<_>>();
2590 let containing_module;
2591 match self.resolve_module_path(&module_path, UseLexicalScope, Some(span)) {
2593 let (span, msg) = match err {
2594 Some((span, msg)) => (span, msg),
2596 let msg = format!("Use of undeclared type or module `{}`",
2597 names_to_string(&module_path));
2602 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
2605 Indeterminate => return Err(false),
2606 Success(resulting_module) => {
2607 containing_module = resulting_module;
2611 let name = segments.last().unwrap().identifier.name;
2613 self.resolve_name_in_module(containing_module, name, namespace, false, Some(span));
2614 result.success().ok_or(false)
2617 /// Invariant: This must be called only during main resolution, not during
2618 /// import resolution.
2619 fn resolve_crate_relative_path<T>(&mut self, span: Span, segments: &[T], namespace: Namespace)
2620 -> Result<&'a NameBinding<'a>,
2621 bool /* true if an error was reported */>
2624 let module_path = segments.split_last().unwrap().1.iter().map(T::name).collect::<Vec<_>>();
2625 let root_module = self.graph_root;
2627 let containing_module;
2628 match self.resolve_module_path_from_root(root_module, &module_path, 0, Some(span)) {
2630 let (span, msg) = match err {
2631 Some((span, msg)) => (span, msg),
2633 let msg = format!("Use of undeclared module `::{}`",
2634 names_to_string(&module_path));
2639 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
2643 Indeterminate => return Err(false),
2645 Success(resulting_module) => {
2646 containing_module = resulting_module;
2650 let name = segments.last().unwrap().name();
2652 self.resolve_name_in_module(containing_module, name, namespace, false, Some(span));
2653 result.success().ok_or(false)
2656 fn with_no_errors<T, F>(&mut self, f: F) -> T
2657 where F: FnOnce(&mut Resolver) -> T
2659 self.emit_errors = false;
2661 self.emit_errors = true;
2665 // Calls `f` with a `Resolver` whose current lexical scope is `module`'s lexical scope,
2666 // i.e. the module's items and the prelude (unless the module is `#[no_implicit_prelude]`).
2667 // FIXME #34673: This needs testing.
2668 pub fn with_module_lexical_scope<T, F>(&mut self, module: Module<'a>, f: F) -> T
2669 where F: FnOnce(&mut Resolver<'a>) -> T,
2671 self.with_empty_ribs(|this| {
2672 this.value_ribs.push(Rib::new(ModuleRibKind(module)));
2673 this.type_ribs.push(Rib::new(ModuleRibKind(module)));
2678 fn with_empty_ribs<T, F>(&mut self, f: F) -> T
2679 where F: FnOnce(&mut Resolver<'a>) -> T,
2681 let value_ribs = replace(&mut self.value_ribs, Vec::new());
2682 let type_ribs = replace(&mut self.type_ribs, Vec::new());
2683 let label_ribs = replace(&mut self.label_ribs, Vec::new());
2685 let result = f(self);
2686 self.value_ribs = value_ribs;
2687 self.type_ribs = type_ribs;
2688 self.label_ribs = label_ribs;
2692 fn find_fallback_in_self_type(&mut self, name: Name) -> FallbackSuggestion {
2693 fn extract_node_id(t: &Ty) -> Option<NodeId> {
2695 TyKind::Path(None, _) => Some(t.id),
2696 TyKind::Rptr(_, ref mut_ty) => extract_node_id(&mut_ty.ty),
2697 // This doesn't handle the remaining `Ty` variants as they are not
2698 // that commonly the self_type, it might be interesting to provide
2699 // support for those in future.
2704 if let Some(node_id) = self.current_self_type.as_ref().and_then(extract_node_id) {
2705 // Look for a field with the same name in the current self_type.
2706 if let Some(resolution) = self.def_map.get(&node_id) {
2707 match resolution.base_def {
2708 Def::Enum(did) | Def::TyAlias(did) |
2709 Def::Struct(did) | Def::Variant(_, did) if resolution.depth == 0 => {
2710 if let Some(fields) = self.structs.get(&did) {
2711 if fields.iter().any(|&field_name| name == field_name) {
2721 // Look for a method in the current trait.
2722 if let Some((trait_did, ref trait_ref)) = self.current_trait_ref {
2723 if let Some(&is_static_method) = self.trait_item_map.get(&(name, trait_did)) {
2724 if is_static_method {
2725 return TraitMethod(path_names_to_string(&trait_ref.path, 0));
2735 fn find_best_match(&mut self, name: &str) -> SuggestionType {
2736 if let Some(macro_name) = self.session.available_macros
2737 .borrow().iter().find(|n| n.as_str() == name) {
2738 return SuggestionType::Macro(format!("{}!", macro_name));
2741 let names = self.value_ribs
2744 .flat_map(|rib| rib.bindings.keys().map(|ident| &ident.name));
2746 if let Some(found) = find_best_match_for_name(names, name, None) {
2748 return SuggestionType::Function(found);
2750 } SuggestionType::NotFound
2753 fn resolve_labeled_block(&mut self, label: Option<ast::Ident>, id: NodeId, block: &Block) {
2754 if let Some(label) = label {
2755 let def = Def::Label(id);
2756 self.with_label_rib(|this| {
2757 this.label_ribs.last_mut().unwrap().bindings.insert(label, def);
2758 this.visit_block(block);
2761 self.visit_block(block);
2765 fn resolve_expr(&mut self, expr: &Expr, parent: Option<&Expr>) {
2766 // First, record candidate traits for this expression if it could
2767 // result in the invocation of a method call.
2769 self.record_candidate_traits_for_expr_if_necessary(expr);
2771 // Next, resolve the node.
2773 ExprKind::Path(ref maybe_qself, ref path) => {
2774 // This is a local path in the value namespace. Walk through
2775 // scopes looking for it.
2776 if let Some(path_res) = self.resolve_possibly_assoc_item(expr.id,
2777 maybe_qself.as_ref(), path, ValueNS) {
2778 // Check if struct variant
2779 let is_struct_variant = if let Def::Variant(_, variant_id) = path_res.base_def {
2780 self.structs.contains_key(&variant_id)
2784 if is_struct_variant {
2785 let _ = self.structs.contains_key(&path_res.base_def.def_id());
2786 let path_name = path_names_to_string(path, 0);
2788 let mut err = resolve_struct_error(self,
2790 ResolutionError::StructVariantUsedAsFunction(&path_name));
2792 let msg = format!("did you mean to write: `{} {{ /* fields */ }}`?",
2794 if self.emit_errors {
2797 err.span_help(expr.span, &msg);
2800 self.record_def(expr.id, err_path_resolution());
2802 // Write the result into the def map.
2803 debug!("(resolving expr) resolved `{}`",
2804 path_names_to_string(path, 0));
2806 // Partial resolutions will need the set of traits in scope,
2807 // so they can be completed during typeck.
2808 if path_res.depth != 0 {
2809 let method_name = path.segments.last().unwrap().identifier.name;
2810 let traits = self.get_traits_containing_item(method_name);
2811 self.trait_map.insert(expr.id, traits);
2814 self.record_def(expr.id, path_res);
2817 // Be helpful if the name refers to a struct
2818 // (The pattern matching def_tys where the id is in self.structs
2819 // matches on regular structs while excluding tuple- and enum-like
2820 // structs, which wouldn't result in this error.)
2821 let path_name = path_names_to_string(path, 0);
2822 let type_res = self.with_no_errors(|this| {
2823 this.resolve_path(expr.id, path, 0, TypeNS)
2826 self.record_def(expr.id, err_path_resolution());
2828 if let Ok(Def::Struct(..)) = type_res.map(|r| r.base_def) {
2830 ResolutionError::StructVariantUsedAsFunction(&path_name);
2831 let mut err = resolve_struct_error(self, expr.span, error_variant);
2833 let msg = format!("did you mean to write: `{} {{ /* fields */ }}`?",
2836 if self.emit_errors {
2839 err.span_help(expr.span, &msg);
2843 // Keep reporting some errors even if they're ignored above.
2844 if let Err(true) = self.resolve_path(expr.id, path, 0, ValueNS) {
2845 // `resolve_path` already reported the error
2847 let mut method_scope = false;
2848 let mut is_static = false;
2849 self.value_ribs.iter().rev().all(|rib| {
2850 method_scope = match rib.kind {
2851 MethodRibKind(is_static_) => {
2852 is_static = is_static_;
2855 ItemRibKind | ConstantItemRibKind => false,
2856 _ => return true, // Keep advancing
2858 false // Stop advancing
2862 &path_name[..] == keywords::SelfValue.name().as_str() {
2865 ResolutionError::SelfNotAvailableInStaticMethod);
2867 let last_name = path.segments.last().unwrap().identifier.name;
2868 let (mut msg, is_field) =
2869 match self.find_fallback_in_self_type(last_name) {
2871 // limit search to 5 to reduce the number
2872 // of stupid suggestions
2873 (match self.find_best_match(&path_name) {
2874 SuggestionType::Macro(s) => {
2875 format!("the macro `{}`", s)
2877 SuggestionType::Function(s) => format!("`{}`", s),
2878 SuggestionType::NotFound => "".to_string(),
2882 (if is_static && method_scope {
2885 format!("`self.{}`", path_name)
2888 TraitItem => (format!("to call `self.{}`", path_name), false),
2889 TraitMethod(path_str) =>
2890 (format!("to call `{}::{}`", path_str, path_name), false),
2893 let mut context = UnresolvedNameContext::Other;
2894 let mut def = Def::Err;
2895 if !msg.is_empty() {
2896 msg = format!(". Did you mean {}?", msg);
2898 // we display a help message if this is a module
2899 let name_path = path.segments.iter()
2900 .map(|seg| seg.identifier.name)
2901 .collect::<Vec<_>>();
2903 match self.resolve_module_path(&name_path[..],
2907 if let Some(def_type) = e.def {
2910 context = UnresolvedNameContext::PathIsMod(parent);
2918 ResolutionError::UnresolvedName {
2922 is_static_method: method_scope && is_static,
2931 visit::walk_expr(self, expr);
2934 ExprKind::Struct(ref path, _, _) => {
2935 // Resolve the path to the structure it goes to. We don't
2936 // check to ensure that the path is actually a structure; that
2937 // is checked later during typeck.
2938 match self.resolve_path(expr.id, path, 0, TypeNS) {
2939 Ok(definition) => self.record_def(expr.id, definition),
2940 Err(true) => self.record_def(expr.id, err_path_resolution()),
2942 debug!("(resolving expression) didn't find struct def",);
2946 ResolutionError::DoesNotNameAStruct(
2947 &path_names_to_string(path, 0))
2949 self.record_def(expr.id, err_path_resolution());
2953 visit::walk_expr(self, expr);
2956 ExprKind::Loop(_, Some(label)) | ExprKind::While(_, _, Some(label)) => {
2957 self.with_label_rib(|this| {
2958 let def = Def::Label(expr.id);
2961 let rib = this.label_ribs.last_mut().unwrap();
2962 rib.bindings.insert(label.node, def);
2965 visit::walk_expr(this, expr);
2969 ExprKind::Break(Some(label)) | ExprKind::Continue(Some(label)) => {
2970 match self.search_label(label.node) {
2972 self.record_def(expr.id, err_path_resolution());
2975 ResolutionError::UndeclaredLabel(&label.node.name.as_str()))
2977 Some(def @ Def::Label(_)) => {
2978 // Since this def is a label, it is never read.
2979 self.record_def(expr.id, PathResolution::new(def))
2982 span_bug!(expr.span, "label wasn't mapped to a label def!")
2987 ExprKind::IfLet(ref pattern, ref subexpression, ref if_block, ref optional_else) => {
2988 self.visit_expr(subexpression);
2990 self.value_ribs.push(Rib::new(NormalRibKind));
2991 self.resolve_pattern(pattern, PatternSource::IfLet, &mut HashMap::new());
2992 self.visit_block(if_block);
2993 self.value_ribs.pop();
2995 optional_else.as_ref().map(|expr| self.visit_expr(expr));
2998 ExprKind::WhileLet(ref pattern, ref subexpression, ref block, label) => {
2999 self.visit_expr(subexpression);
3000 self.value_ribs.push(Rib::new(NormalRibKind));
3001 self.resolve_pattern(pattern, PatternSource::WhileLet, &mut HashMap::new());
3003 self.resolve_labeled_block(label.map(|l| l.node), expr.id, block);
3005 self.value_ribs.pop();
3008 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, label) => {
3009 self.visit_expr(subexpression);
3010 self.value_ribs.push(Rib::new(NormalRibKind));
3011 self.resolve_pattern(pattern, PatternSource::For, &mut HashMap::new());
3013 self.resolve_labeled_block(label.map(|l| l.node), expr.id, block);
3015 self.value_ribs.pop();
3018 ExprKind::Field(ref subexpression, _) => {
3019 self.resolve_expr(subexpression, Some(expr));
3021 ExprKind::MethodCall(_, ref types, ref arguments) => {
3022 let mut arguments = arguments.iter();
3023 self.resolve_expr(arguments.next().unwrap(), Some(expr));
3024 for argument in arguments {
3025 self.resolve_expr(argument, None);
3027 for ty in types.iter() {
3033 visit::walk_expr(self, expr);
3038 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3040 ExprKind::Field(_, name) => {
3041 // FIXME(#6890): Even though you can't treat a method like a
3042 // field, we need to add any trait methods we find that match
3043 // the field name so that we can do some nice error reporting
3044 // later on in typeck.
3045 let traits = self.get_traits_containing_item(name.node.name);
3046 self.trait_map.insert(expr.id, traits);
3048 ExprKind::MethodCall(name, _, _) => {
3049 debug!("(recording candidate traits for expr) recording traits for {}",
3051 let traits = self.get_traits_containing_item(name.node.name);
3052 self.trait_map.insert(expr.id, traits);
3060 fn get_traits_containing_item(&mut self, name: Name) -> Vec<TraitCandidate> {
3061 debug!("(getting traits containing item) looking for '{}'", name);
3063 fn add_trait_info(found_traits: &mut Vec<TraitCandidate>,
3064 trait_def_id: DefId,
3065 import_id: Option<NodeId>,
3067 debug!("(adding trait info) found trait {:?} for method '{}'",
3070 found_traits.push(TraitCandidate {
3071 def_id: trait_def_id,
3072 import_id: import_id,
3076 let mut found_traits = Vec::new();
3077 // Look for the current trait.
3078 if let Some((trait_def_id, _)) = self.current_trait_ref {
3079 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3080 add_trait_info(&mut found_traits, trait_def_id, None, name);
3084 let mut search_module = self.current_module;
3086 // Look for trait children.
3087 let mut search_in_module = |this: &mut Self, module: Module<'a>| {
3088 let mut traits = module.traits.borrow_mut();
3089 if traits.is_none() {
3090 let mut collected_traits = Vec::new();
3091 module.for_each_child(|name, ns, binding| {
3092 if ns != TypeNS { return }
3093 if let Some(Def::Trait(_)) = binding.def() {
3094 collected_traits.push((name, binding));
3097 *traits = Some(collected_traits.into_boxed_slice());
3100 for &(trait_name, binding) in traits.as_ref().unwrap().iter() {
3101 let trait_def_id = binding.def().unwrap().def_id();
3102 if this.trait_item_map.contains_key(&(name, trait_def_id)) {
3103 let mut import_id = None;
3104 if let NameBindingKind::Import { directive, .. } = binding.kind {
3105 let id = directive.id;
3106 this.maybe_unused_trait_imports.insert(id);
3107 this.add_to_glob_map(id, trait_name);
3108 import_id = Some(id);
3110 add_trait_info(&mut found_traits, trait_def_id, import_id, name);
3114 search_in_module(self, search_module);
3116 match search_module.parent_link {
3117 NoParentLink | ModuleParentLink(..) => {
3118 if !search_module.no_implicit_prelude.get() {
3119 self.prelude.map(|prelude| search_in_module(self, prelude));
3123 BlockParentLink(parent_module, _) => {
3124 search_module = parent_module;
3132 /// When name resolution fails, this method can be used to look up candidate
3133 /// entities with the expected name. It allows filtering them using the
3134 /// supplied predicate (which should be used to only accept the types of
3135 /// definitions expected e.g. traits). The lookup spans across all crates.
3137 /// NOTE: The method does not look into imports, but this is not a problem,
3138 /// since we report the definitions (thus, the de-aliased imports).
3139 fn lookup_candidates<FilterFn>(&mut self,
3141 namespace: Namespace,
3142 filter_fn: FilterFn) -> SuggestedCandidates
3143 where FilterFn: Fn(Def) -> bool {
3145 let mut lookup_results = Vec::new();
3146 let mut worklist = Vec::new();
3147 worklist.push((self.graph_root, Vec::new(), false));
3149 while let Some((in_module,
3151 in_module_is_extern)) = worklist.pop() {
3152 self.populate_module_if_necessary(in_module);
3154 in_module.for_each_child(|name, ns, name_binding| {
3156 // avoid imports entirely
3157 if name_binding.is_import() { return; }
3159 // collect results based on the filter function
3160 if let Some(def) = name_binding.def() {
3161 if name == lookup_name && ns == namespace && filter_fn(def) {
3163 let ident = ast::Ident::with_empty_ctxt(name);
3164 let params = PathParameters::none();
3165 let segment = PathSegment {
3169 let span = name_binding.span;
3170 let mut segms = path_segments.clone();
3171 segms.push(segment);
3177 // the entity is accessible in the following cases:
3178 // 1. if it's defined in the same crate, it's always
3179 // accessible (since private entities can be made public)
3180 // 2. if it's defined in another crate, it's accessible
3181 // only if both the module is public and the entity is
3182 // declared as public (due to pruning, we don't explore
3183 // outside crate private modules => no need to check this)
3184 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
3185 lookup_results.push(path);
3190 // collect submodules to explore
3191 if let Some(module) = name_binding.module() {
3193 let path_segments = match module.parent_link {
3194 NoParentLink => path_segments.clone(),
3195 ModuleParentLink(_, name) => {
3196 let mut paths = path_segments.clone();
3197 let ident = ast::Ident::with_empty_ctxt(name);
3198 let params = PathParameters::none();
3199 let segm = PathSegment {
3209 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
3210 // add the module to the lookup
3211 let is_extern = in_module_is_extern || name_binding.is_extern_crate();
3212 if !worklist.iter().any(|&(m, _, _)| m.def == module.def) {
3213 worklist.push((module, path_segments, is_extern));
3220 SuggestedCandidates {
3221 name: lookup_name.as_str().to_string(),
3222 candidates: lookup_results,
3226 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
3227 debug!("(recording def) recording {:?} for {}", resolution, node_id);
3228 if let Some(prev_res) = self.def_map.insert(node_id, resolution) {
3229 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
3233 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
3234 let (path, id) = match *vis {
3235 ast::Visibility::Public => return ty::Visibility::Public,
3236 ast::Visibility::Crate(_) => return ty::Visibility::Restricted(ast::CRATE_NODE_ID),
3237 ast::Visibility::Restricted { ref path, id } => (path, id),
3238 ast::Visibility::Inherited => return self.current_vis,
3241 let segments: Vec<_> = path.segments.iter().map(|seg| seg.identifier.name).collect();
3242 let mut path_resolution = err_path_resolution();
3243 let vis = match self.resolve_module_path(&segments, DontUseLexicalScope, Some(path.span)) {
3244 Success(module) => {
3245 let def = module.def.unwrap();
3246 path_resolution = PathResolution::new(def);
3247 ty::Visibility::Restricted(self.definitions.as_local_node_id(def.def_id()).unwrap())
3249 Failed(Some((span, msg))) => {
3250 self.session.span_err(span, &format!("failed to resolve module path. {}", msg));
3251 ty::Visibility::Public
3254 self.session.span_err(path.span, "unresolved module path");
3255 ty::Visibility::Public
3258 self.def_map.insert(id, path_resolution);
3259 if !self.is_accessible(vis) {
3260 let msg = format!("visibilities can only be restricted to ancestor modules");
3261 self.session.span_err(path.span, &msg);
3266 fn is_accessible(&self, vis: ty::Visibility) -> bool {
3267 vis.is_at_least(self.current_vis, self)
3270 fn report_privacy_errors(&self) {
3271 if self.privacy_errors.len() == 0 { return }
3272 let mut reported_spans = HashSet::new();
3273 for &PrivacyError(span, name, binding) in &self.privacy_errors {
3274 if !reported_spans.insert(span) { continue }
3275 if binding.is_extern_crate() {
3276 // Warn when using an inaccessible extern crate.
3277 let node_id = binding.module().unwrap().extern_crate_id.unwrap();
3278 let msg = format!("extern crate `{}` is private", name);
3279 self.session.add_lint(lint::builtin::INACCESSIBLE_EXTERN_CRATE, node_id, span, msg);
3281 let def = binding.def().unwrap();
3282 self.session.span_err(span, &format!("{} `{}` is private", def.kind_name(), name));
3287 fn report_conflict(&self,
3291 binding: &NameBinding,
3292 old_binding: &NameBinding) {
3293 // Error on the second of two conflicting names
3294 if old_binding.span.lo > binding.span.lo {
3295 return self.report_conflict(parent, name, ns, old_binding, binding);
3298 let container = match parent.def {
3299 Some(Def::Mod(_)) => "module",
3300 Some(Def::Trait(_)) => "trait",
3305 let (participle, noun) = match old_binding.is_import() || old_binding.is_extern_crate() {
3306 true => ("imported", "import"),
3307 false => ("defined", "definition"),
3310 let span = binding.span;
3312 let kind = match (ns, old_binding.module()) {
3313 (ValueNS, _) => "a value",
3314 (TypeNS, Some(module)) if module.extern_crate_id.is_some() => "an extern crate",
3315 (TypeNS, Some(module)) if module.is_normal() => "a module",
3316 (TypeNS, Some(module)) if module.is_trait() => "a trait",
3317 (TypeNS, _) => "a type",
3319 format!("{} named `{}` has already been {} in this {}",
3320 kind, name, participle, container)
3323 let mut err = match (old_binding.is_extern_crate(), binding.is_extern_crate()) {
3324 (true, true) => struct_span_err!(self.session, span, E0259, "{}", msg),
3325 (true, _) | (_, true) if binding.is_import() || old_binding.is_import() => {
3326 let mut e = struct_span_err!(self.session, span, E0254, "{}", msg);
3327 e.span_label(span, &"already imported");
3330 (true, _) | (_, true) => struct_span_err!(self.session, span, E0260, "{}", msg),
3331 _ => match (old_binding.is_import(), binding.is_import()) {
3332 (false, false) => struct_span_err!(self.session, span, E0428, "{}", msg),
3334 let mut e = struct_span_err!(self.session, span, E0252, "{}", msg);
3335 e.span_label(span, &format!("already imported"));
3339 let mut e = struct_span_err!(self.session, span, E0255, "{}", msg);
3340 e.span_label(span, &format!("`{}` was already imported", name));
3346 if old_binding.span != syntax_pos::DUMMY_SP {
3347 err.span_label(old_binding.span, &format!("previous {} of `{}` here", noun, name));
3353 fn names_to_string(names: &[Name]) -> String {
3354 let mut first = true;
3355 let mut result = String::new();
3360 result.push_str("::")
3362 result.push_str(&name.as_str());
3367 fn path_names_to_string(path: &Path, depth: usize) -> String {
3368 let names: Vec<ast::Name> = path.segments[..path.segments.len() - depth]
3370 .map(|seg| seg.identifier.name)
3372 names_to_string(&names[..])
3375 /// When an entity with a given name is not available in scope, we search for
3376 /// entities with that name in all crates. This method allows outputting the
3377 /// results of this search in a programmer-friendly way
3378 fn show_candidates(session: &mut DiagnosticBuilder,
3379 candidates: &SuggestedCandidates) {
3381 let paths = &candidates.candidates;
3383 if paths.len() > 0 {
3384 // don't show more than MAX_CANDIDATES results, so
3385 // we're consistent with the trait suggestions
3386 const MAX_CANDIDATES: usize = 5;
3388 // we want consistent results across executions, but candidates are produced
3389 // by iterating through a hash map, so make sure they are ordered:
3390 let mut path_strings: Vec<_> = paths.into_iter()
3391 .map(|p| path_names_to_string(&p, 0))
3393 path_strings.sort();
3395 // behave differently based on how many candidates we have:
3396 if !paths.is_empty() {
3397 if paths.len() == 1 {
3399 &format!("you can import it into scope: `use {};`.",
3403 session.help("you can import several candidates \
3404 into scope (`use ...;`):");
3405 let count = path_strings.len() as isize - MAX_CANDIDATES as isize + 1;
3407 for (idx, path_string) in path_strings.iter().enumerate() {
3408 if idx == MAX_CANDIDATES - 1 && count > 1 {
3410 &format!(" and {} other candidates", count).to_string(),
3415 &format!(" `{}`", path_string).to_string(),
3424 &format!("no candidates by the name of `{}` found in your \
3425 project; maybe you misspelled the name or forgot to import \
3426 an external crate?", candidates.name.to_string()),
3431 /// A somewhat inefficient routine to obtain the name of a module.
3432 fn module_to_string(module: Module) -> String {
3433 let mut names = Vec::new();
3435 fn collect_mod(names: &mut Vec<ast::Name>, module: Module) {
3436 match module.parent_link {
3438 ModuleParentLink(ref module, name) => {
3440 collect_mod(names, module);
3442 BlockParentLink(ref module, _) => {
3443 // danger, shouldn't be ident?
3444 names.push(token::intern("<opaque>"));
3445 collect_mod(names, module);
3449 collect_mod(&mut names, module);
3451 if names.is_empty() {
3452 return "???".to_string();
3454 names_to_string(&names.into_iter().rev().collect::<Vec<ast::Name>>())
3457 fn err_path_resolution() -> PathResolution {
3458 PathResolution::new(Def::Err)
3461 #[derive(PartialEq,Copy, Clone)]
3462 pub enum MakeGlobMap {
3467 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }