1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // Do not remove on snapshot creation. Needed for bootstrap. (Issue #22364)
12 #![cfg_attr(stage0, feature(custom_attribute))]
13 #![crate_name = "rustc_resolve"]
14 #![unstable(feature = "rustc_private", issue = "27812")]
16 #![crate_type = "dylib"]
17 #![crate_type = "rlib"]
18 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
19 html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
20 html_root_url = "https://doc.rust-lang.org/nightly/")]
22 #![feature(associated_consts)]
23 #![feature(borrow_state)]
24 #![feature(rustc_diagnostic_macros)]
25 #![feature(rustc_private)]
26 #![feature(slice_splits)]
27 #![feature(staged_api)]
29 #[macro_use] extern crate log;
30 #[macro_use] extern crate syntax;
31 #[macro_use] #[no_link] extern crate rustc_bitflags;
32 extern crate rustc_front;
36 use self::PatternBindingMode::*;
37 use self::Namespace::*;
38 use self::NamespaceResult::*;
39 use self::NameDefinition::*;
40 use self::ResolveResult::*;
41 use self::FallbackSuggestion::*;
42 use self::TypeParameters::*;
44 use self::UseLexicalScopeFlag::*;
45 use self::ModulePrefixResult::*;
46 use self::AssocItemResolveResult::*;
47 use self::NameSearchType::*;
48 use self::BareIdentifierPatternResolution::*;
49 use self::ParentLink::*;
50 use self::ModuleKind::*;
51 use self::FallbackChecks::*;
53 use rustc::front::map as hir_map;
54 use rustc::session::Session;
56 use rustc::metadata::csearch;
57 use rustc::metadata::decoder::{DefLike, DlDef, DlField, DlImpl};
58 use rustc::middle::def::*;
59 use rustc::middle::def_id::DefId;
60 use rustc::middle::pat_util::pat_bindings;
61 use rustc::middle::privacy::*;
62 use rustc::middle::subst::{ParamSpace, FnSpace, TypeSpace};
63 use rustc::middle::ty::{Freevar, FreevarMap, TraitMap, GlobMap};
64 use rustc::util::nodemap::{NodeMap, DefIdSet, FnvHashMap};
65 use rustc::util::lev_distance::lev_distance;
68 use syntax::ast::{Ident, Name, NodeId, CrateNum, TyIs, TyI8, TyI16, TyI32, TyI64};
69 use syntax::ast::{TyUs, TyU8, TyU16, TyU32, TyU64, TyF64, TyF32};
70 use syntax::attr::AttrMetaMethods;
71 use syntax::ext::mtwt;
72 use syntax::parse::token::{self, special_names, special_idents};
74 use syntax::codemap::{self, Span, Pos};
76 use rustc_front::visit::{self, FnKind, Visitor};
78 use rustc_front::hir::{Arm, BindByRef, BindByValue, BindingMode, Block};
79 use rustc_front::hir::{ConstImplItem, Crate};
80 use rustc_front::hir::{Expr, ExprAgain, ExprBreak, ExprField};
81 use rustc_front::hir::{ExprLoop, ExprWhile, ExprMethodCall};
82 use rustc_front::hir::{ExprPath, ExprStruct, FnDecl};
83 use rustc_front::hir::{ForeignItemFn, ForeignItemStatic, Generics};
84 use rustc_front::hir::{ImplItem, Item, ItemConst, ItemEnum, ItemExternCrate};
85 use rustc_front::hir::{ItemFn, ItemForeignMod, ItemImpl, ItemMod, ItemStatic, ItemDefaultImpl};
86 use rustc_front::hir::{ItemStruct, ItemTrait, ItemTy, ItemUse};
87 use rustc_front::hir::{Local, MethodImplItem};
88 use rustc_front::hir::{Pat, PatEnum, PatIdent, PatLit, PatQPath};
89 use rustc_front::hir::{PatRange, PatStruct, Path, PrimTy};
90 use rustc_front::hir::{TraitRef, Ty, TyBool, TyChar, TyFloat, TyInt};
91 use rustc_front::hir::{TyRptr, TyStr, TyUint, TyPath, TyPtr};
92 use rustc_front::hir::TypeImplItem;
93 use rustc_front::util::walk_pat;
95 use std::collections::{HashMap, HashSet};
96 use std::cell::{Cell, RefCell};
98 use std::mem::replace;
99 use std::rc::{Rc, Weak};
102 use resolve_imports::{Target, ImportDirective, ImportResolution};
103 use resolve_imports::Shadowable;
105 // NB: This module needs to be declared first so diagnostics are
106 // registered before they are used.
111 mod build_reduced_graph;
114 // Perform the callback, not walking deeper if the return is true
115 macro_rules! execute_callback {
116 ($node: expr, $walker: expr) => (
117 if let Some(ref callback) = $walker.callback {
118 if callback($node, &mut $walker.resolved) {
125 pub enum ResolutionError<'a> {
126 /// error E0401: can't use type parameters from outer function
127 TypeParametersFromOuterFunction,
128 /// error E0402: cannot use an outer type parameter in this context
129 OuterTypeParameterContext,
130 /// error E0403: the name is already used for a type parameter in this type parameter list
131 NameAlreadyUsedInTypeParameterList(Name),
132 /// error E0404: is not a trait
133 IsNotATrait(&'a str),
134 /// error E0405: use of undeclared trait name
135 UndeclaredTraitName(&'a str),
136 /// error E0406: undeclared associated type
137 UndeclaredAssociatedType,
138 /// error E0407: method is not a member of trait
139 MethodNotMemberOfTrait(Name, &'a str),
140 /// error E0437: type is not a member of trait
141 TypeNotMemberOfTrait(Name, &'a str),
142 /// error E0438: const is not a member of trait
143 ConstNotMemberOfTrait(Name, &'a str),
144 /// error E0408: variable `{}` from pattern #1 is not bound in pattern
145 VariableNotBoundInPattern(Name, usize),
146 /// error E0409: variable is bound with different mode in pattern #{} than in pattern #1
147 VariableBoundWithDifferentMode(Name, usize),
148 /// error E0410: variable from pattern is not bound in pattern #1
149 VariableNotBoundInParentPattern(Name, usize),
150 /// error E0411: use of `Self` outside of an impl or trait
151 SelfUsedOutsideImplOrTrait,
152 /// error E0412: use of undeclared
153 UseOfUndeclared(&'a str, &'a str),
154 /// error E0413: declaration shadows an enum variant or unit-like struct in scope
155 DeclarationShadowsEnumVariantOrUnitLikeStruct(Name),
156 /// error E0414: only irrefutable patterns allowed here
157 OnlyIrrefutablePatternsAllowedHere,
158 /// error E0415: identifier is bound more than once in this parameter list
159 IdentifierBoundMoreThanOnceInParameterList(&'a str),
160 /// error E0416: identifier is bound more than once in the same pattern
161 IdentifierBoundMoreThanOnceInSamePattern(&'a str),
162 /// error E0417: static variables cannot be referenced in a pattern
163 StaticVariableReference,
164 /// error E0418: is not an enum variant, struct or const
165 NotAnEnumVariantStructOrConst(&'a str),
166 /// error E0419: unresolved enum variant, struct or const
167 UnresolvedEnumVariantStructOrConst(&'a str),
168 /// error E0420: is not an associated const
169 NotAnAssociatedConst(&'a str),
170 /// error E0421: unresolved associated const
171 UnresolvedAssociatedConst(&'a str),
172 /// error E0422: does not name a struct
173 DoesNotNameAStruct(&'a str),
174 /// error E0423: is a struct variant name, but this expression uses it like a function name
175 StructVariantUsedAsFunction(&'a str),
176 /// error E0424: `self` is not available in a static method
177 SelfNotAvailableInStaticMethod,
178 /// error E0425: unresolved name
179 UnresolvedName(&'a str, &'a str),
180 /// error E0426: use of undeclared label
181 UndeclaredLabel(&'a str),
182 /// error E0427: cannot use `ref` binding mode with ...
183 CannotUseRefBindingModeWith(&'a str),
184 /// error E0428: duplicate definition
185 DuplicateDefinition(&'a str, Name),
186 /// error E0429: `self` imports are only allowed within a { } list
187 SelfImportsOnlyAllowedWithin,
188 /// error E0430: `self` import can only appear once in the list
189 SelfImportCanOnlyAppearOnceInTheList,
190 /// error E0431: `self` import can only appear in an import list with a non-empty prefix
191 SelfImportOnlyInImportListWithNonEmptyPrefix,
192 /// error E0432: unresolved import
193 UnresolvedImport(Option<(&'a str, &'a str)>),
194 /// error E0433: failed to resolve
195 FailedToResolve(&'a str),
196 /// error E0434: can't capture dynamic environment in a fn item
197 CannotCaptureDynamicEnvironmentInFnItem,
198 /// error E0435: attempt to use a non-constant value in a constant
199 AttemptToUseNonConstantValueInConstant,
202 fn resolve_error<'b, 'a:'b, 'tcx:'a>(resolver: &'b Resolver<'a, 'tcx>, span: syntax::codemap::Span,
203 resolution_error: ResolutionError<'b>) {
204 if !resolver.emit_errors {
207 match resolution_error {
208 ResolutionError::TypeParametersFromOuterFunction => {
209 span_err!(resolver.session, span, E0401, "can't use type parameters from \
210 outer function; try using a local \
211 type parameter instead");
213 ResolutionError::OuterTypeParameterContext => {
214 span_err!(resolver.session, span, E0402,
215 "cannot use an outer type parameter in this context");
217 ResolutionError::NameAlreadyUsedInTypeParameterList(name) => {
218 span_err!(resolver.session, span, E0403,
219 "the name `{}` is already used for a type \
220 parameter in this type parameter list", name);
222 ResolutionError::IsNotATrait(name) => {
223 span_err!(resolver.session, span, E0404,
224 "`{}` is not a trait",
227 ResolutionError::UndeclaredTraitName(name) => {
228 span_err!(resolver.session, span, E0405,
229 "use of undeclared trait name `{}`",
232 ResolutionError::UndeclaredAssociatedType => {
233 span_err!(resolver.session, span, E0406, "undeclared associated type");
235 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
236 span_err!(resolver.session, span, E0407,
237 "method `{}` is not a member of trait `{}`",
241 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
242 span_err!(resolver.session, span, E0437,
243 "type `{}` is not a member of trait `{}`",
247 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
248 span_err!(resolver.session, span, E0438,
249 "const `{}` is not a member of trait `{}`",
253 ResolutionError::VariableNotBoundInPattern(variable_name, pattern_number) => {
254 span_err!(resolver.session, span, E0408,
255 "variable `{}` from pattern #1 is not bound in pattern #{}",
259 ResolutionError::VariableBoundWithDifferentMode(variable_name, pattern_number) => {
260 span_err!(resolver.session, span, E0409,
261 "variable `{}` is bound with different \
262 mode in pattern #{} than in pattern #1",
266 ResolutionError::VariableNotBoundInParentPattern(variable_name, pattern_number) => {
267 span_err!(resolver.session, span, E0410,
268 "variable `{}` from pattern #{} is not bound in pattern #1",
272 ResolutionError::SelfUsedOutsideImplOrTrait => {
273 span_err!(resolver.session, span, E0411, "use of `Self` outside of an impl or trait");
275 ResolutionError::UseOfUndeclared(kind, name) => {
276 span_err!(resolver.session, span, E0412,
277 "use of undeclared {} `{}`",
281 ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(name) => {
282 span_err!(resolver.session, span, E0413,
283 "declaration of `{}` shadows an enum variant or unit-like struct in \
287 ResolutionError::OnlyIrrefutablePatternsAllowedHere => {
288 span_err!(resolver.session, span, E0414, "only irrefutable patterns allowed here");
290 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
291 span_err!(resolver.session, span, E0415,
292 "identifier `{}` is bound more than once in this parameter list",
295 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
296 span_err!(resolver.session, span, E0416,
297 "identifier `{}` is bound more than once in the same pattern",
300 ResolutionError::StaticVariableReference => {
301 span_err!(resolver.session, span, E0417, "static variables cannot be \
302 referenced in a pattern, \
303 use a `const` instead");
305 ResolutionError::NotAnEnumVariantStructOrConst(name) => {
306 span_err!(resolver.session, span, E0418,
307 "`{}` is not an enum variant, struct or const",
310 ResolutionError::UnresolvedEnumVariantStructOrConst(name) => {
311 span_err!(resolver.session, span, E0419,
312 "unresolved enum variant, struct or const `{}`",
315 ResolutionError::NotAnAssociatedConst(name) => {
316 span_err!(resolver.session, span, E0420,
317 "`{}` is not an associated const",
320 ResolutionError::UnresolvedAssociatedConst(name) => {
321 span_err!(resolver.session, span, E0421,
322 "unresolved associated const `{}`",
325 ResolutionError::DoesNotNameAStruct(name) => {
326 span_err!(resolver.session, span, E0422, "`{}` does not name a structure", name);
328 ResolutionError::StructVariantUsedAsFunction(path_name) => {
329 span_err!(resolver.session, span, E0423,
330 "`{}` is the name of a struct or struct variant, \
331 but this expression \
332 uses it like a function name",
335 ResolutionError::SelfNotAvailableInStaticMethod => {
336 span_err!(resolver.session, span, E0424, "`self` is not available in a static method. \
337 Maybe a `self` argument is missing?");
339 ResolutionError::UnresolvedName(path, name) => {
340 span_err!(resolver.session, span, E0425,
341 "unresolved name `{}`{}",
345 ResolutionError::UndeclaredLabel(name) => {
346 span_err!(resolver.session, span, E0426,
347 "use of undeclared label `{}`",
350 ResolutionError::CannotUseRefBindingModeWith(descr) => {
351 span_err!(resolver.session, span, E0427,
352 "cannot use `ref` binding mode with {}",
355 ResolutionError::DuplicateDefinition(namespace, name) => {
356 span_err!(resolver.session, span, E0428,
357 "duplicate definition of {} `{}`",
361 ResolutionError::SelfImportsOnlyAllowedWithin => {
362 span_err!(resolver.session, span, E0429, "{}",
363 "`self` imports are only allowed within a { } list");
365 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
366 span_err!(resolver.session, span, E0430,
367 "`self` import can only appear once in the list");
369 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
370 span_err!(resolver.session, span, E0431,
371 "`self` import can only appear in an import list with a \
374 ResolutionError::UnresolvedImport(name) => {
375 let msg = match name {
376 Some((n, p)) => format!("unresolved import `{}`{}", n, p),
377 None => "unresolved import".to_owned()
379 span_err!(resolver.session, span, E0432, "{}", msg);
381 ResolutionError::FailedToResolve(msg) => {
382 span_err!(resolver.session, span, E0433, "failed to resolve. {}", msg);
384 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
385 span_err!(resolver.session, span, E0434, "{}",
386 "can't capture dynamic environment in a fn item; \
387 use the || { ... } closure form instead");
389 ResolutionError::AttemptToUseNonConstantValueInConstant =>{
390 span_err!(resolver.session, span, E0435,
391 "attempt to use a non-constant value in a constant");
396 #[derive(Copy, Clone)]
399 binding_mode: BindingMode,
402 // Map from the name in a pattern to its binding mode.
403 type BindingMap = HashMap<Name, BindingInfo>;
405 #[derive(Copy, Clone, PartialEq)]
406 enum PatternBindingMode {
408 LocalIrrefutableMode,
409 ArgumentIrrefutableMode,
412 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
418 /// A NamespaceResult represents the result of resolving an import in
419 /// a particular namespace. The result is either definitely-resolved,
420 /// definitely- unresolved, or unknown.
422 enum NamespaceResult {
423 /// Means that resolve hasn't gathered enough information yet to determine
424 /// whether the name is bound in this namespace. (That is, it hasn't
425 /// resolved all `use` directives yet.)
427 /// Means that resolve has determined that the name is definitely
428 /// not bound in the namespace.
430 /// Means that resolve has determined that the name is bound in the Module
431 /// argument, and specified by the NameBindings argument.
432 BoundResult(Rc<Module>, Rc<NameBindings>)
435 impl NamespaceResult {
436 fn is_unknown(&self) -> bool {
438 UnknownResult => true,
442 fn is_unbound(&self) -> bool {
444 UnboundResult => true,
450 enum NameDefinition {
451 // The name was unbound.
453 // The name identifies an immediate child.
454 ChildNameDefinition(Def, LastPrivate),
455 // The name identifies an import.
456 ImportNameDefinition(Def, LastPrivate),
459 impl<'a, 'v, 'tcx> Visitor<'v> for Resolver<'a, 'tcx> {
460 fn visit_item(&mut self, item: &Item) {
461 execute_callback!(hir_map::Node::NodeItem(item), self);
462 self.resolve_item(item);
464 fn visit_arm(&mut self, arm: &Arm) {
465 self.resolve_arm(arm);
467 fn visit_block(&mut self, block: &Block) {
468 execute_callback!(hir_map::Node::NodeBlock(block), self);
469 self.resolve_block(block);
471 fn visit_expr(&mut self, expr: &Expr) {
472 execute_callback!(hir_map::Node::NodeExpr(expr), self);
473 self.resolve_expr(expr);
475 fn visit_local(&mut self, local: &Local) {
476 execute_callback!(hir_map::Node::NodeLocal(&*local.pat), self);
477 self.resolve_local(local);
479 fn visit_ty(&mut self, ty: &Ty) {
480 self.resolve_type(ty);
482 fn visit_generics(&mut self, generics: &Generics) {
483 self.resolve_generics(generics);
485 fn visit_poly_trait_ref(&mut self,
486 tref: &hir::PolyTraitRef,
487 m: &hir::TraitBoundModifier) {
488 match self.resolve_trait_reference(tref.trait_ref.ref_id, &tref.trait_ref.path, 0) {
489 Ok(def) => self.record_def(tref.trait_ref.ref_id, def),
490 Err(_) => { /* error already reported */ }
492 visit::walk_poly_trait_ref(self, tref, m);
494 fn visit_variant(&mut self, variant: &hir::Variant, generics: &Generics) {
495 execute_callback!(hir_map::Node::NodeVariant(variant), self);
496 if let Some(ref dis_expr) = variant.node.disr_expr {
497 // resolve the discriminator expr as a constant
498 self.with_constant_rib(|this| {
499 this.visit_expr(&**dis_expr);
503 // `visit::walk_variant` without the discriminant expression.
504 match variant.node.kind {
505 hir::TupleVariantKind(ref variant_arguments) => {
506 for variant_argument in variant_arguments {
507 self.visit_ty(&*variant_argument.ty);
510 hir::StructVariantKind(ref struct_definition) => {
511 self.visit_struct_def(&**struct_definition,
518 fn visit_foreign_item(&mut self, foreign_item: &hir::ForeignItem) {
519 execute_callback!(hir_map::Node::NodeForeignItem(foreign_item), self);
520 let type_parameters = match foreign_item.node {
521 ForeignItemFn(_, ref generics) => {
522 HasTypeParameters(generics, FnSpace, ItemRibKind)
524 ForeignItemStatic(..) => NoTypeParameters
526 self.with_type_parameter_rib(type_parameters, |this| {
527 visit::walk_foreign_item(this, foreign_item);
530 fn visit_fn(&mut self,
531 function_kind: FnKind<'v>,
532 declaration: &'v FnDecl,
536 let rib_kind = match function_kind {
537 FnKind::ItemFn(_, generics, _, _, _, _) => {
538 self.visit_generics(generics);
541 FnKind::Method(_, sig, _) => {
542 self.visit_generics(&sig.generics);
543 self.visit_explicit_self(&sig.explicit_self);
546 FnKind::Closure(..) => ClosureRibKind(node_id)
548 self.resolve_function(rib_kind, declaration, block);
552 type ErrorMessage = Option<(Span, String)>;
554 enum ResolveResult<T> {
555 Failed(ErrorMessage), // Failed to resolve the name, optional helpful error message.
556 Indeterminate, // Couldn't determine due to unresolved globs.
557 Success(T) // Successfully resolved the import.
560 impl<T> ResolveResult<T> {
561 fn success(&self) -> bool {
562 match *self { Success(_) => true, _ => false }
566 enum FallbackSuggestion {
571 StaticMethod(String),
575 #[derive(Copy, Clone)]
576 enum TypeParameters<'a> {
582 // Identifies the things that these parameters
583 // were declared on (type, fn, etc)
586 // The kind of the rib used for type parameters.
590 // The rib kind controls the translation of local
591 // definitions (`DefLocal`) to upvars (`DefUpvar`).
592 #[derive(Copy, Clone, Debug)]
594 // No translation needs to be applied.
597 // We passed through a closure scope at the given node ID.
598 // Translate upvars as appropriate.
599 ClosureRibKind(NodeId /* func id */),
601 // We passed through an impl or trait and are now in one of its
602 // methods. Allow references to ty params that impl or trait
603 // binds. Disallow any other upvars (including other ty params that are
607 // We passed through an item scope. Disallow upvars.
610 // We're in a constant item. Can't refer to dynamic stuff.
614 #[derive(Copy, Clone)]
615 enum UseLexicalScopeFlag {
620 enum ModulePrefixResult {
622 PrefixFound(Rc<Module>, usize)
625 #[derive(Copy, Clone)]
626 enum AssocItemResolveResult {
627 /// Syntax such as `<T>::item`, which can't be resolved until type
630 /// We should have been able to resolve the associated item.
631 ResolveAttempt(Option<PathResolution>),
634 #[derive(Copy, Clone, PartialEq)]
635 enum NameSearchType {
636 /// We're doing a name search in order to resolve a `use` directive.
639 /// We're doing a name search in order to resolve a path type, a path
640 /// expression, or a path pattern.
644 #[derive(Copy, Clone)]
645 enum BareIdentifierPatternResolution {
646 FoundStructOrEnumVariant(Def, LastPrivate),
647 FoundConst(Def, LastPrivate),
648 BareIdentifierPatternUnresolved
654 bindings: HashMap<Name, DefLike>,
659 fn new(kind: RibKind) -> Rib {
661 bindings: HashMap::new(),
667 /// The link from a module up to its nearest parent node.
668 #[derive(Clone,Debug)]
671 ModuleParentLink(Weak<Module>, Name),
672 BlockParentLink(Weak<Module>, NodeId)
675 /// The type of module this is.
676 #[derive(Copy, Clone, PartialEq, Debug)]
685 /// One node in the tree of modules.
687 parent_link: ParentLink,
688 def_id: Cell<Option<DefId>>,
689 kind: Cell<ModuleKind>,
692 children: RefCell<HashMap<Name, Rc<NameBindings>>>,
693 imports: RefCell<Vec<ImportDirective>>,
695 // The external module children of this node that were declared with
697 external_module_children: RefCell<HashMap<Name, Rc<Module>>>,
699 // The anonymous children of this node. Anonymous children are pseudo-
700 // modules that are implicitly created around items contained within
703 // For example, if we have this:
711 // There will be an anonymous module created around `g` with the ID of the
712 // entry block for `f`.
713 anonymous_children: RefCell<NodeMap<Rc<Module>>>,
715 // The status of resolving each import in this module.
716 import_resolutions: RefCell<HashMap<Name, ImportResolution>>,
718 // The number of unresolved globs that this module exports.
719 glob_count: Cell<usize>,
721 // The number of unresolved pub imports (both regular and globs) in this module
722 pub_count: Cell<usize>,
724 // The number of unresolved pub glob imports in this module
725 pub_glob_count: Cell<usize>,
727 // The index of the import we're resolving.
728 resolved_import_count: Cell<usize>,
730 // Whether this module is populated. If not populated, any attempt to
731 // access the children must be preceded with a
732 // `populate_module_if_necessary` call.
733 populated: Cell<bool>,
737 fn new(parent_link: ParentLink,
738 def_id: Option<DefId>,
744 parent_link: parent_link,
745 def_id: Cell::new(def_id),
746 kind: Cell::new(kind),
747 is_public: is_public,
748 children: RefCell::new(HashMap::new()),
749 imports: RefCell::new(Vec::new()),
750 external_module_children: RefCell::new(HashMap::new()),
751 anonymous_children: RefCell::new(NodeMap()),
752 import_resolutions: RefCell::new(HashMap::new()),
753 glob_count: Cell::new(0),
754 pub_count: Cell::new(0),
755 pub_glob_count: Cell::new(0),
756 resolved_import_count: Cell::new(0),
757 populated: Cell::new(!external),
761 fn all_imports_resolved(&self) -> bool {
762 if self.imports.borrow_state() == ::std::cell::BorrowState::Writing {
763 // it is currently being resolved ! so nope
766 self.imports.borrow().len() == self.resolved_import_count.get()
772 pub fn inc_glob_count(&self) {
773 self.glob_count.set(self.glob_count.get() + 1);
775 pub fn dec_glob_count(&self) {
776 assert!(self.glob_count.get() > 0);
777 self.glob_count.set(self.glob_count.get() - 1);
779 pub fn inc_pub_count(&self) {
780 self.pub_count.set(self.pub_count.get() + 1);
782 pub fn dec_pub_count(&self) {
783 assert!(self.pub_count.get() > 0);
784 self.pub_count.set(self.pub_count.get() - 1);
786 pub fn inc_pub_glob_count(&self) {
787 self.pub_glob_count.set(self.pub_glob_count.get() + 1);
789 pub fn dec_pub_glob_count(&self) {
790 assert!(self.pub_glob_count.get() > 0);
791 self.pub_glob_count.set(self.pub_glob_count.get() - 1);
795 impl fmt::Debug for Module {
796 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
797 write!(f, "{:?}, kind: {:?}, {}",
800 if self.is_public { "public" } else { "private" } )
806 flags DefModifiers: u8 {
807 const PUBLIC = 1 << 0,
808 const IMPORTABLE = 1 << 1,
812 // Records a possibly-private type definition.
813 #[derive(Clone,Debug)]
815 modifiers: DefModifiers, // see note in ImportResolution about how to use this
816 module_def: Option<Rc<Module>>,
817 type_def: Option<Def>,
818 type_span: Option<Span>
821 // Records a possibly-private value definition.
822 #[derive(Clone, Copy, Debug)]
824 modifiers: DefModifiers, // see note in ImportResolution about how to use this
826 value_span: Option<Span>,
829 // Records the definitions (at most one for each namespace) that a name is
832 pub struct NameBindings {
833 type_def: RefCell<Option<TypeNsDef>>, //< Meaning in type namespace.
834 value_def: RefCell<Option<ValueNsDef>>, //< Meaning in value namespace.
838 fn new() -> NameBindings {
840 type_def: RefCell::new(None),
841 value_def: RefCell::new(None),
845 /// Creates a new module in this set of name bindings.
846 fn define_module(&self,
847 parent_link: ParentLink,
848 def_id: Option<DefId>,
853 // Merges the module with the existing type def or creates a new one.
854 let modifiers = if is_public {
857 DefModifiers::empty()
858 } | DefModifiers::IMPORTABLE;
859 let module_ = Rc::new(Module::new(parent_link,
864 let type_def = self.type_def.borrow().clone();
867 *self.type_def.borrow_mut() = Some(TypeNsDef {
868 modifiers: modifiers,
869 module_def: Some(module_),
875 *self.type_def.borrow_mut() = Some(TypeNsDef {
876 modifiers: modifiers,
877 module_def: Some(module_),
879 type_def: type_def.type_def
885 /// Sets the kind of the module, creating a new one if necessary.
886 fn set_module_kind(&self,
887 parent_link: ParentLink,
888 def_id: Option<DefId>,
893 let modifiers = if is_public {
896 DefModifiers::empty()
897 } | DefModifiers::IMPORTABLE;
898 let type_def = self.type_def.borrow().clone();
901 let module = Module::new(parent_link,
906 *self.type_def.borrow_mut() = Some(TypeNsDef {
907 modifiers: modifiers,
908 module_def: Some(Rc::new(module)),
914 match type_def.module_def {
916 let module = Module::new(parent_link,
921 *self.type_def.borrow_mut() = Some(TypeNsDef {
922 modifiers: modifiers,
923 module_def: Some(Rc::new(module)),
924 type_def: type_def.type_def,
928 Some(module_def) => module_def.kind.set(kind),
934 /// Records a type definition.
935 fn define_type(&self, def: Def, sp: Span, modifiers: DefModifiers) {
936 debug!("defining type for def {:?} with modifiers {:?}", def, modifiers);
937 // Merges the type with the existing type def or creates a new one.
938 let type_def = self.type_def.borrow().clone();
941 *self.type_def.borrow_mut() = Some(TypeNsDef {
945 modifiers: modifiers,
949 *self.type_def.borrow_mut() = Some(TypeNsDef {
950 module_def: type_def.module_def,
953 modifiers: modifiers,
959 /// Records a value definition.
960 fn define_value(&self, def: Def, sp: Span, modifiers: DefModifiers) {
961 debug!("defining value for def {:?} with modifiers {:?}", def, modifiers);
962 *self.value_def.borrow_mut() = Some(ValueNsDef {
964 value_span: Some(sp),
965 modifiers: modifiers,
969 /// Returns the module node if applicable.
970 fn get_module_if_available(&self) -> Option<Rc<Module>> {
971 match *self.type_def.borrow() {
972 Some(ref type_def) => type_def.module_def.clone(),
977 /// Returns the module node. Panics if this node does not have a module
979 fn get_module(&self) -> Rc<Module> {
980 match self.get_module_if_available() {
982 panic!("get_module called on a node with no module \
985 Some(module_def) => module_def
989 fn defined_in_namespace(&self, namespace: Namespace) -> bool {
991 TypeNS => return self.type_def.borrow().is_some(),
992 ValueNS => return self.value_def.borrow().is_some()
996 fn defined_in_public_namespace(&self, namespace: Namespace) -> bool {
997 self.defined_in_namespace_with(namespace, DefModifiers::PUBLIC)
1000 fn defined_in_namespace_with(&self, namespace: Namespace, modifiers: DefModifiers) -> bool {
1002 TypeNS => match *self.type_def.borrow() {
1003 Some(ref def) => def.modifiers.contains(modifiers), None => false
1005 ValueNS => match *self.value_def.borrow() {
1006 Some(ref def) => def.modifiers.contains(modifiers), None => false
1011 fn def_for_namespace(&self, namespace: Namespace) -> Option<Def> {
1014 match *self.type_def.borrow() {
1016 Some(ref type_def) => {
1017 match type_def.type_def {
1018 Some(type_def) => Some(type_def),
1020 match type_def.module_def {
1021 Some(ref module) => {
1022 match module.def_id.get() {
1023 Some(did) => Some(DefMod(did)),
1035 match *self.value_def.borrow() {
1037 Some(value_def) => Some(value_def.def)
1043 fn span_for_namespace(&self, namespace: Namespace) -> Option<Span> {
1044 if self.defined_in_namespace(namespace) {
1047 match *self.type_def.borrow() {
1049 Some(ref type_def) => type_def.type_span
1053 match *self.value_def.borrow() {
1055 Some(ref value_def) => value_def.value_span
1064 fn is_public(&self, namespace: Namespace) -> bool {
1067 let type_def = self.type_def.borrow();
1068 type_def.as_ref().unwrap().modifiers.contains(DefModifiers::PUBLIC)
1071 let value_def = self.value_def.borrow();
1072 value_def.as_ref().unwrap().modifiers.contains(DefModifiers::PUBLIC)
1078 /// Interns the names of the primitive types.
1079 struct PrimitiveTypeTable {
1080 primitive_types: HashMap<Name, PrimTy>,
1083 impl PrimitiveTypeTable {
1084 fn new() -> PrimitiveTypeTable {
1085 let mut table = PrimitiveTypeTable {
1086 primitive_types: HashMap::new()
1089 table.intern("bool", TyBool);
1090 table.intern("char", TyChar);
1091 table.intern("f32", TyFloat(TyF32));
1092 table.intern("f64", TyFloat(TyF64));
1093 table.intern("isize", TyInt(TyIs));
1094 table.intern("i8", TyInt(TyI8));
1095 table.intern("i16", TyInt(TyI16));
1096 table.intern("i32", TyInt(TyI32));
1097 table.intern("i64", TyInt(TyI64));
1098 table.intern("str", TyStr);
1099 table.intern("usize", TyUint(TyUs));
1100 table.intern("u8", TyUint(TyU8));
1101 table.intern("u16", TyUint(TyU16));
1102 table.intern("u32", TyUint(TyU32));
1103 table.intern("u64", TyUint(TyU64));
1108 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1109 self.primitive_types.insert(token::intern(string), primitive_type);
1113 /// The main resolver class.
1114 pub struct Resolver<'a, 'tcx:'a> {
1115 session: &'a Session,
1117 ast_map: &'a hir_map::Map<'tcx>,
1119 graph_root: NameBindings,
1121 trait_item_map: FnvHashMap<(Name, DefId), DefId>,
1123 structs: FnvHashMap<DefId, Vec<Name>>,
1125 // The number of imports that are currently unresolved.
1126 unresolved_imports: usize,
1128 // The module that represents the current item scope.
1129 current_module: Rc<Module>,
1131 // The current set of local scopes, for values.
1132 // FIXME #4948: Reuse ribs to avoid allocation.
1133 value_ribs: Vec<Rib>,
1135 // The current set of local scopes, for types.
1136 type_ribs: Vec<Rib>,
1138 // The current set of local scopes, for labels.
1139 label_ribs: Vec<Rib>,
1141 // The trait that the current context can refer to.
1142 current_trait_ref: Option<(DefId, TraitRef)>,
1144 // The current self type if inside an impl (used for better errors).
1145 current_self_type: Option<Ty>,
1147 // The idents for the primitive types.
1148 primitive_type_table: PrimitiveTypeTable,
1151 freevars: RefCell<FreevarMap>,
1152 freevars_seen: RefCell<NodeMap<NodeMap<usize>>>,
1153 export_map: ExportMap,
1154 trait_map: TraitMap,
1155 external_exports: ExternalExports,
1157 // Whether or not to print error messages. Can be set to true
1158 // when getting additional info for error message suggestions,
1159 // so as to avoid printing duplicate errors
1162 make_glob_map: bool,
1163 // Maps imports to the names of items actually imported (this actually maps
1164 // all imports, but only glob imports are actually interesting).
1167 used_imports: HashSet<(NodeId, Namespace)>,
1168 used_crates: HashSet<CrateNum>,
1170 // Callback function for intercepting walks
1171 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>,
1172 // The intention is that the callback modifies this flag.
1173 // Once set, the resolver falls out of the walk, preserving the ribs.
1178 #[derive(PartialEq)]
1179 enum FallbackChecks {
1184 impl<'a, 'tcx> Resolver<'a, 'tcx> {
1185 fn new(session: &'a Session,
1186 ast_map: &'a hir_map::Map<'tcx>,
1188 make_glob_map: MakeGlobMap) -> Resolver<'a, 'tcx> {
1189 let graph_root = NameBindings::new();
1191 graph_root.define_module(NoParentLink,
1192 Some(DefId { krate: 0, node: 0 }),
1198 let current_module = graph_root.get_module();
1205 // The outermost module has def ID 0; this is not reflected in the
1208 graph_root: graph_root,
1210 trait_item_map: FnvHashMap(),
1211 structs: FnvHashMap(),
1213 unresolved_imports: 0,
1215 current_module: current_module,
1216 value_ribs: Vec::new(),
1217 type_ribs: Vec::new(),
1218 label_ribs: Vec::new(),
1220 current_trait_ref: None,
1221 current_self_type: None,
1223 primitive_type_table: PrimitiveTypeTable::new(),
1225 def_map: RefCell::new(NodeMap()),
1226 freevars: RefCell::new(NodeMap()),
1227 freevars_seen: RefCell::new(NodeMap()),
1228 export_map: NodeMap(),
1229 trait_map: NodeMap(),
1230 used_imports: HashSet::new(),
1231 used_crates: HashSet::new(),
1232 external_exports: DefIdSet(),
1235 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1236 glob_map: HashMap::new(),
1245 fn record_import_use(&mut self, import_id: NodeId, name: Name) {
1246 if !self.make_glob_map {
1249 if self.glob_map.contains_key(&import_id) {
1250 self.glob_map.get_mut(&import_id).unwrap().insert(name);
1254 let mut new_set = HashSet::new();
1255 new_set.insert(name);
1256 self.glob_map.insert(import_id, new_set);
1259 fn get_trait_name(&self, did: DefId) -> Name {
1261 self.ast_map.expect_item(did.node).ident.name
1263 csearch::get_trait_name(&self.session.cstore, did)
1267 fn create_name_bindings_from_module(module: Rc<Module>) -> NameBindings {
1269 type_def: RefCell::new(Some(TypeNsDef {
1270 modifiers: DefModifiers::IMPORTABLE,
1271 module_def: Some(module),
1275 value_def: RefCell::new(None),
1279 /// Checks that the names of external crates don't collide with other
1280 /// external crates.
1281 fn check_for_conflicts_between_external_crates(&self,
1285 if module.external_module_children.borrow().contains_key(&name) {
1286 span_err!(self.session, span, E0259,
1287 "an external crate named `{}` has already \
1288 been imported into this module",
1293 /// Checks that the names of items don't collide with external crates.
1294 fn check_for_conflicts_between_external_crates_and_items(&self,
1298 if module.external_module_children.borrow().contains_key(&name) {
1299 span_err!(self.session, span, E0260,
1300 "the name `{}` conflicts with an external \
1301 crate that has been imported into this \
1307 /// Resolves the given module path from the given root `module_`.
1308 fn resolve_module_path_from_root(&mut self,
1309 module_: Rc<Module>,
1310 module_path: &[Name],
1313 name_search_type: NameSearchType,
1315 -> ResolveResult<(Rc<Module>, LastPrivate)> {
1316 fn search_parent_externals(needle: Name, module: &Rc<Module>)
1317 -> Option<Rc<Module>> {
1318 match module.external_module_children.borrow().get(&needle) {
1319 Some(_) => Some(module.clone()),
1320 None => match module.parent_link {
1321 ModuleParentLink(ref parent, _) => {
1322 search_parent_externals(needle, &parent.upgrade().unwrap())
1329 let mut search_module = module_;
1330 let mut index = index;
1331 let module_path_len = module_path.len();
1332 let mut closest_private = lp;
1334 // Resolve the module part of the path. This does not involve looking
1335 // upward though scope chains; we simply resolve names directly in
1336 // modules as we go.
1337 while index < module_path_len {
1338 let name = module_path[index];
1339 match self.resolve_name_in_module(search_module.clone(),
1345 let segment_name = name.as_str();
1346 let module_name = module_to_string(&*search_module);
1347 let mut span = span;
1348 let msg = if "???" == &module_name[..] {
1349 span.hi = span.lo + Pos::from_usize(segment_name.len());
1351 match search_parent_externals(name,
1352 &self.current_module) {
1354 let path_str = names_to_string(module_path);
1355 let target_mod_str = module_to_string(&*module);
1356 let current_mod_str =
1357 module_to_string(&*self.current_module);
1359 let prefix = if target_mod_str == current_mod_str {
1360 "self::".to_string()
1362 format!("{}::", target_mod_str)
1365 format!("Did you mean `{}{}`?", prefix, path_str)
1367 None => format!("Maybe a missing `extern crate {}`?",
1371 format!("Could not find `{}` in `{}`",
1376 return Failed(Some((span, msg)));
1378 Failed(err) => return Failed(err),
1380 debug!("(resolving module path for import) module \
1381 resolution is indeterminate: {}",
1383 return Indeterminate;
1385 Success((target, used_proxy)) => {
1386 // Check to see whether there are type bindings, and, if
1387 // so, whether there is a module within.
1388 match *target.bindings.type_def.borrow() {
1389 Some(ref type_def) => {
1390 match type_def.module_def {
1392 let msg = format!("Not a module `{}`",
1395 return Failed(Some((span, msg)));
1397 Some(ref module_def) => {
1398 search_module = module_def.clone();
1400 // track extern crates for unused_extern_crate lint
1401 if let Some(did) = module_def.def_id.get() {
1402 self.used_crates.insert(did.krate);
1405 // Keep track of the closest
1406 // private module used when
1407 // resolving this import chain.
1408 if !used_proxy && !search_module.is_public {
1409 if let Some(did) = search_module.def_id.get() {
1410 closest_private = LastMod(DependsOn(did));
1417 // There are no type bindings at all.
1418 let msg = format!("Not a module `{}`",
1420 return Failed(Some((span, msg)));
1429 return Success((search_module, closest_private));
1432 /// Attempts to resolve the module part of an import directive or path
1433 /// rooted at the given module.
1435 /// On success, returns the resolved module, and the closest *private*
1436 /// module found to the destination when resolving this path.
1437 fn resolve_module_path(&mut self,
1438 module_: Rc<Module>,
1439 module_path: &[Name],
1440 use_lexical_scope: UseLexicalScopeFlag,
1442 name_search_type: NameSearchType)
1443 -> ResolveResult<(Rc<Module>, LastPrivate)> {
1444 let module_path_len = module_path.len();
1445 assert!(module_path_len > 0);
1447 debug!("(resolving module path for import) processing `{}` rooted at `{}`",
1448 names_to_string(module_path),
1449 module_to_string(&*module_));
1451 // Resolve the module prefix, if any.
1452 let module_prefix_result = self.resolve_module_prefix(module_.clone(),
1458 match module_prefix_result {
1460 let mpath = names_to_string(module_path);
1461 let mpath = &mpath[..];
1462 match mpath.rfind(':') {
1464 let msg = format!("Could not find `{}` in `{}`",
1465 // idx +- 1 to account for the
1466 // colons on either side
1469 return Failed(Some((span, msg)));
1476 Failed(err) => return Failed(err),
1478 debug!("(resolving module path for import) indeterminate; \
1480 return Indeterminate;
1482 Success(NoPrefixFound) => {
1483 // There was no prefix, so we're considering the first element
1484 // of the path. How we handle this depends on whether we were
1485 // instructed to use lexical scope or not.
1486 match use_lexical_scope {
1487 DontUseLexicalScope => {
1488 // This is a crate-relative path. We will start the
1489 // resolution process at index zero.
1490 search_module = self.graph_root.get_module();
1492 last_private = LastMod(AllPublic);
1494 UseLexicalScope => {
1495 // This is not a crate-relative path. We resolve the
1496 // first component of the path in the current lexical
1497 // scope and then proceed to resolve below that.
1498 match self.resolve_module_in_lexical_scope(module_,
1500 Failed(err) => return Failed(err),
1502 debug!("(resolving module path for import) \
1503 indeterminate; bailing");
1504 return Indeterminate;
1506 Success(containing_module) => {
1507 search_module = containing_module;
1509 last_private = LastMod(AllPublic);
1515 Success(PrefixFound(ref containing_module, index)) => {
1516 search_module = containing_module.clone();
1517 start_index = index;
1518 last_private = LastMod(DependsOn(containing_module.def_id
1524 self.resolve_module_path_from_root(search_module,
1532 /// Invariant: This must only be called during main resolution, not during
1533 /// import resolution.
1534 fn resolve_item_in_lexical_scope(&mut self,
1535 module_: Rc<Module>,
1537 namespace: Namespace)
1538 -> ResolveResult<(Target, bool)> {
1539 debug!("(resolving item in lexical scope) resolving `{}` in \
1540 namespace {:?} in `{}`",
1543 module_to_string(&*module_));
1545 // The current module node is handled specially. First, check for
1546 // its immediate children.
1547 build_reduced_graph::populate_module_if_necessary(self, &module_);
1549 match module_.children.borrow().get(&name) {
1551 if name_bindings.defined_in_namespace(namespace) => {
1552 debug!("top name bindings succeeded");
1553 return Success((Target::new(module_.clone(),
1554 name_bindings.clone(),
1558 Some(_) | None => { /* Not found; continue. */ }
1561 // Now check for its import directives. We don't have to have resolved
1562 // all its imports in the usual way; this is because chains of
1563 // adjacent import statements are processed as though they mutated the
1565 if let Some(import_resolution) = module_.import_resolutions.borrow().get(&name) {
1566 match (*import_resolution).target_for_namespace(namespace) {
1568 // Not found; continue.
1569 debug!("(resolving item in lexical scope) found \
1570 import resolution, but not in namespace {:?}",
1574 debug!("(resolving item in lexical scope) using \
1575 import resolution");
1576 // track used imports and extern crates as well
1577 let id = import_resolution.id(namespace);
1578 self.used_imports.insert((id, namespace));
1579 self.record_import_use(id, name);
1580 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id.get() {
1581 self.used_crates.insert(kid);
1583 return Success((target, false));
1588 // Search for external modules.
1589 if namespace == TypeNS {
1590 // FIXME (21114): In principle unclear `child` *has* to be lifted.
1591 let child = module_.external_module_children.borrow().get(&name).cloned();
1592 if let Some(module) = child {
1594 Rc::new(Resolver::create_name_bindings_from_module(module));
1595 debug!("lower name bindings succeeded");
1596 return Success((Target::new(module_,
1603 // Finally, proceed up the scope chain looking for parent modules.
1604 let mut search_module = module_;
1606 // Go to the next parent.
1607 match search_module.parent_link.clone() {
1609 // No more parents. This module was unresolved.
1610 debug!("(resolving item in lexical scope) unresolved \
1612 return Failed(None);
1614 ModuleParentLink(parent_module_node, _) => {
1615 match search_module.kind.get() {
1616 NormalModuleKind => {
1617 // We stop the search here.
1618 debug!("(resolving item in lexical \
1619 scope) unresolved module: not \
1620 searching through module \
1622 return Failed(None);
1627 AnonymousModuleKind => {
1628 search_module = parent_module_node.upgrade().unwrap();
1632 BlockParentLink(ref parent_module_node, _) => {
1633 search_module = parent_module_node.upgrade().unwrap();
1637 // Resolve the name in the parent module.
1638 match self.resolve_name_in_module(search_module.clone(),
1643 Failed(Some((span, msg))) => {
1644 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
1646 Failed(None) => (), // Continue up the search chain.
1648 // We couldn't see through the higher scope because of an
1649 // unresolved import higher up. Bail.
1651 debug!("(resolving item in lexical scope) indeterminate \
1652 higher scope; bailing");
1653 return Indeterminate;
1655 Success((target, used_reexport)) => {
1656 // We found the module.
1657 debug!("(resolving item in lexical scope) found name \
1659 return Success((target, used_reexport));
1665 /// Resolves a module name in the current lexical scope.
1666 fn resolve_module_in_lexical_scope(&mut self,
1667 module_: Rc<Module>,
1669 -> ResolveResult<Rc<Module>> {
1670 // If this module is an anonymous module, resolve the item in the
1671 // lexical scope. Otherwise, resolve the item from the crate root.
1672 let resolve_result = self.resolve_item_in_lexical_scope(module_, name, TypeNS);
1673 match resolve_result {
1674 Success((target, _)) => {
1675 let bindings = &*target.bindings;
1676 match *bindings.type_def.borrow() {
1677 Some(ref type_def) => {
1678 match type_def.module_def {
1680 debug!("!!! (resolving module in lexical \
1681 scope) module wasn't actually a \
1683 return Failed(None);
1685 Some(ref module_def) => {
1686 return Success(module_def.clone());
1691 debug!("!!! (resolving module in lexical scope) module
1692 wasn't actually a module!");
1693 return Failed(None);
1698 debug!("(resolving module in lexical scope) indeterminate; \
1700 return Indeterminate;
1703 debug!("(resolving module in lexical scope) failed to resolve");
1709 /// Returns the nearest normal module parent of the given module.
1710 fn get_nearest_normal_module_parent(&mut self, module_: Rc<Module>)
1711 -> Option<Rc<Module>> {
1712 let mut module_ = module_;
1714 match module_.parent_link.clone() {
1715 NoParentLink => return None,
1716 ModuleParentLink(new_module, _) |
1717 BlockParentLink(new_module, _) => {
1718 let new_module = new_module.upgrade().unwrap();
1719 match new_module.kind.get() {
1720 NormalModuleKind => return Some(new_module),
1724 AnonymousModuleKind => module_ = new_module,
1731 /// Returns the nearest normal module parent of the given module, or the
1732 /// module itself if it is a normal module.
1733 fn get_nearest_normal_module_parent_or_self(&mut self, module_: Rc<Module>)
1735 match module_.kind.get() {
1736 NormalModuleKind => return module_,
1740 AnonymousModuleKind => {
1741 match self.get_nearest_normal_module_parent(module_.clone()) {
1743 Some(new_module) => new_module
1749 /// Resolves a "module prefix". A module prefix is one or both of (a) `self::`;
1750 /// (b) some chain of `super::`.
1751 /// grammar: (SELF MOD_SEP ) ? (SUPER MOD_SEP) *
1752 fn resolve_module_prefix(&mut self,
1753 module_: Rc<Module>,
1754 module_path: &[Name])
1755 -> ResolveResult<ModulePrefixResult> {
1756 // Start at the current module if we see `self` or `super`, or at the
1757 // top of the crate otherwise.
1758 let mut i = match &*module_path[0].as_str() {
1761 _ => return Success(NoPrefixFound),
1763 let mut containing_module = self.get_nearest_normal_module_parent_or_self(module_);
1765 // Now loop through all the `super`s we find.
1766 while i < module_path.len() && "super" == module_path[i].as_str() {
1767 debug!("(resolving module prefix) resolving `super` at {}",
1768 module_to_string(&*containing_module));
1769 match self.get_nearest_normal_module_parent(containing_module) {
1770 None => return Failed(None),
1771 Some(new_module) => {
1772 containing_module = new_module;
1778 debug!("(resolving module prefix) finished resolving prefix at {}",
1779 module_to_string(&*containing_module));
1781 return Success(PrefixFound(containing_module, i));
1784 /// Attempts to resolve the supplied name in the given module for the
1785 /// given namespace. If successful, returns the target corresponding to
1788 /// The boolean returned on success is an indicator of whether this lookup
1789 /// passed through a public re-export proxy.
1790 fn resolve_name_in_module(&mut self,
1791 module_: Rc<Module>,
1793 namespace: Namespace,
1794 name_search_type: NameSearchType,
1795 allow_private_imports: bool)
1796 -> ResolveResult<(Target, bool)> {
1797 debug!("(resolving name in module) resolving `{}` in `{}`",
1799 module_to_string(&*module_));
1801 // First, check the direct children of the module.
1802 build_reduced_graph::populate_module_if_necessary(self, &module_);
1804 match module_.children.borrow().get(&name) {
1806 if name_bindings.defined_in_namespace(namespace) => {
1807 debug!("(resolving name in module) found node as child");
1808 return Success((Target::new(module_.clone(),
1809 name_bindings.clone(),
1818 // Next, check the module's imports if necessary.
1820 // If this is a search of all imports, we should be done with glob
1821 // resolution at this point.
1822 if name_search_type == PathSearch {
1823 assert_eq!(module_.glob_count.get(), 0);
1826 // Check the list of resolved imports.
1827 match module_.import_resolutions.borrow().get(&name) {
1828 Some(import_resolution) if allow_private_imports ||
1829 import_resolution.is_public => {
1831 if import_resolution.is_public &&
1832 import_resolution.outstanding_references != 0 {
1833 debug!("(resolving name in module) import \
1834 unresolved; bailing out");
1835 return Indeterminate;
1837 match import_resolution.target_for_namespace(namespace) {
1839 debug!("(resolving name in module) name found, \
1840 but not in namespace {:?}",
1844 debug!("(resolving name in module) resolved to \
1846 // track used imports and extern crates as well
1847 let id = import_resolution.id(namespace);
1848 self.used_imports.insert((id, namespace));
1849 self.record_import_use(id, name);
1850 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id.get() {
1851 self.used_crates.insert(kid);
1853 return Success((target, true));
1857 Some(..) | None => {} // Continue.
1860 // Finally, search through external children.
1861 if namespace == TypeNS {
1862 // FIXME (21114): In principle unclear `child` *has* to be lifted.
1863 let child = module_.external_module_children.borrow().get(&name).cloned();
1864 if let Some(module) = child {
1866 Rc::new(Resolver::create_name_bindings_from_module(module));
1867 return Success((Target::new(module_,
1874 // We're out of luck.
1875 debug!("(resolving name in module) failed to resolve `{}`",
1877 return Failed(None);
1880 fn report_unresolved_imports(&mut self, module_: Rc<Module>) {
1881 let index = module_.resolved_import_count.get();
1882 let imports = module_.imports.borrow();
1883 let import_count = imports.len();
1884 if index != import_count {
1886 (*imports)[index].span,
1887 ResolutionError::UnresolvedImport(None));
1890 // Descend into children and anonymous children.
1891 build_reduced_graph::populate_module_if_necessary(self, &module_);
1893 for (_, child_node) in module_.children.borrow().iter() {
1894 match child_node.get_module_if_available() {
1898 Some(child_module) => {
1899 self.report_unresolved_imports(child_module);
1904 for (_, module_) in module_.anonymous_children.borrow().iter() {
1905 self.report_unresolved_imports(module_.clone());
1911 // We maintain a list of value ribs and type ribs.
1913 // Simultaneously, we keep track of the current position in the module
1914 // graph in the `current_module` pointer. When we go to resolve a name in
1915 // the value or type namespaces, we first look through all the ribs and
1916 // then query the module graph. When we resolve a name in the module
1917 // namespace, we can skip all the ribs (since nested modules are not
1918 // allowed within blocks in Rust) and jump straight to the current module
1921 // Named implementations are handled separately. When we find a method
1922 // call, we consult the module node to find all of the implementations in
1923 // scope. This information is lazily cached in the module node. We then
1924 // generate a fake "implementation scope" containing all the
1925 // implementations thus found, for compatibility with old resolve pass.
1927 fn with_scope<F>(&mut self, name: Option<Name>, f: F) where
1928 F: FnOnce(&mut Resolver),
1930 let orig_module = self.current_module.clone();
1932 // Move down in the graph.
1938 build_reduced_graph::populate_module_if_necessary(self, &orig_module);
1940 match orig_module.children.borrow().get(&name) {
1942 debug!("!!! (with scope) didn't find `{}` in `{}`",
1944 module_to_string(&*orig_module));
1946 Some(name_bindings) => {
1947 match (*name_bindings).get_module_if_available() {
1949 debug!("!!! (with scope) didn't find module \
1952 module_to_string(&*orig_module));
1955 self.current_module = module_;
1965 self.current_module = orig_module;
1968 /// Wraps the given definition in the appropriate number of `DefUpvar`
1974 -> Option<DefLike> {
1975 let mut def = match def_like {
1977 _ => return Some(def_like)
1981 self.session.span_bug(span,
1982 &format!("unexpected {:?} in bindings", def))
1984 DefLocal(node_id) => {
1988 // Nothing to do. Continue.
1990 ClosureRibKind(function_id) => {
1993 let mut seen = self.freevars_seen.borrow_mut();
1994 let seen = seen.entry(function_id).or_insert_with(|| NodeMap());
1995 if let Some(&index) = seen.get(&node_id) {
1996 def = DefUpvar(node_id, index, function_id);
1999 let mut freevars = self.freevars.borrow_mut();
2000 let vec = freevars.entry(function_id)
2001 .or_insert_with(|| vec![]);
2002 let depth = vec.len();
2003 vec.push(Freevar { def: prev_def, span: span });
2005 def = DefUpvar(node_id, depth, function_id);
2006 seen.insert(node_id, depth);
2008 ItemRibKind | MethodRibKind => {
2009 // This was an attempt to access an upvar inside a
2010 // named function item. This is not allowed, so we
2015 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem
2019 ConstantItemRibKind => {
2020 // Still doesn't deal with upvars
2024 ResolutionError::AttemptToUseNonConstantValueInConstant
2031 DefTyParam(..) | DefSelfTy(..) => {
2034 NormalRibKind | MethodRibKind | ClosureRibKind(..) => {
2035 // Nothing to do. Continue.
2038 // This was an attempt to use a type parameter outside
2043 ResolutionError::TypeParametersFromOuterFunction);
2046 ConstantItemRibKind => {
2048 resolve_error(self, span, ResolutionError::OuterTypeParameterContext);
2059 /// Searches the current set of local scopes and
2060 /// applies translations for closures.
2061 fn search_ribs(&self,
2065 -> Option<DefLike> {
2066 // FIXME #4950: Try caching?
2068 for (i, rib) in ribs.iter().enumerate().rev() {
2069 if let Some(def_like) = rib.bindings.get(&name).cloned() {
2070 return self.upvarify(&ribs[i + 1..], def_like, span);
2077 /// Searches the current set of local scopes for labels.
2078 /// Stops after meeting a closure.
2079 fn search_label(&self, name: Name) -> Option<DefLike> {
2080 for rib in self.label_ribs.iter().rev() {
2086 // Do not resolve labels across function boundary
2090 let result = rib.bindings.get(&name).cloned();
2091 if result.is_some() {
2098 fn resolve_crate(&mut self, krate: &hir::Crate) {
2099 debug!("(resolving crate) starting");
2101 visit::walk_crate(self, krate);
2104 fn check_if_primitive_type_name(&self, name: Name, span: Span) {
2105 if let Some(_) = self.primitive_type_table.primitive_types.get(&name) {
2106 span_err!(self.session, span, E0317,
2107 "user-defined types or type parameters cannot shadow the primitive types");
2111 fn resolve_item(&mut self, item: &Item) {
2112 let name = item.ident.name;
2114 debug!("(resolving item) resolving {}",
2118 ItemEnum(_, ref generics) |
2119 ItemTy(_, ref generics) |
2120 ItemStruct(_, ref generics) => {
2121 self.check_if_primitive_type_name(name, item.span);
2123 self.with_type_parameter_rib(HasTypeParameters(generics,
2126 |this| visit::walk_item(this, item));
2128 ItemFn(_, _, _, _, ref generics, _) => {
2129 self.with_type_parameter_rib(HasTypeParameters(generics,
2132 |this| visit::walk_item(this, item));
2135 ItemDefaultImpl(_, ref trait_ref) => {
2136 self.with_optional_trait_ref(Some(trait_ref), |_, _| {});
2143 ref impl_items) => {
2144 self.resolve_implementation(generics,
2151 ItemTrait(_, ref generics, ref bounds, ref trait_items) => {
2152 self.check_if_primitive_type_name(name, item.span);
2154 // Create a new rib for the trait-wide type parameters.
2155 self.with_type_parameter_rib(HasTypeParameters(generics,
2159 this.with_self_rib(DefSelfTy(Some(DefId::local(item.id)), None), |this| {
2160 this.visit_generics(generics);
2161 visit::walk_ty_param_bounds_helper(this, bounds);
2163 for trait_item in trait_items {
2164 match trait_item.node {
2165 hir::ConstTraitItem(_, ref default) => {
2166 // Only impose the restrictions of
2167 // ConstRibKind if there's an actual constant
2168 // expression in a provided default.
2169 if default.is_some() {
2170 this.with_constant_rib(|this| {
2171 visit::walk_trait_item(this, trait_item)
2174 visit::walk_trait_item(this, trait_item)
2177 hir::MethodTraitItem(ref sig, _) => {
2178 let type_parameters =
2179 HasTypeParameters(&sig.generics,
2182 this.with_type_parameter_rib(type_parameters, |this| {
2183 visit::walk_trait_item(this, trait_item)
2186 hir::TypeTraitItem(..) => {
2187 this.check_if_primitive_type_name(trait_item.ident.name,
2189 this.with_type_parameter_rib(NoTypeParameters, |this| {
2190 visit::walk_trait_item(this, trait_item)
2199 ItemMod(_) | ItemForeignMod(_) => {
2200 self.with_scope(Some(name), |this| {
2201 visit::walk_item(this, item);
2205 ItemConst(..) | ItemStatic(..) => {
2206 self.with_constant_rib(|this| {
2207 visit::walk_item(this, item);
2211 ItemUse(ref view_path) => {
2212 // check for imports shadowing primitive types
2213 let check_rename = |id, ident: Ident| {
2214 match self.def_map.borrow().get(&id).map(|d| d.full_def()) {
2215 Some(DefTy(..)) | Some(DefStruct(..)) | Some(DefTrait(..)) | None => {
2216 self.check_if_primitive_type_name(ident.name, item.span);
2222 match view_path.node {
2223 hir::ViewPathSimple(ident, _) => {
2224 check_rename(item.id, ident);
2226 hir::ViewPathList(_, ref items) => {
2228 if let Some(ident) = item.node.rename() {
2229 check_rename(item.node.id(), ident);
2237 ItemExternCrate(_) => {
2238 // do nothing, these are just around to be encoded
2243 fn with_type_parameter_rib<F>(&mut self, type_parameters: TypeParameters, f: F) where
2244 F: FnOnce(&mut Resolver),
2246 match type_parameters {
2247 HasTypeParameters(generics, space, rib_kind) => {
2248 let mut function_type_rib = Rib::new(rib_kind);
2249 let mut seen_bindings = HashSet::new();
2250 for (index, type_parameter) in generics.ty_params.iter().enumerate() {
2251 let name = type_parameter.ident.name;
2252 debug!("with_type_parameter_rib: {}", type_parameter.id);
2254 if seen_bindings.contains(&name) {
2256 type_parameter.span,
2257 ResolutionError::NameAlreadyUsedInTypeParameterList(
2261 seen_bindings.insert(name);
2263 // plain insert (no renaming)
2264 function_type_rib.bindings.insert(name,
2265 DlDef(DefTyParam(space,
2267 DefId::local(type_parameter.id),
2270 self.type_ribs.push(function_type_rib);
2273 NoTypeParameters => {
2280 match type_parameters {
2281 HasTypeParameters(..) => { if !self.resolved { self.type_ribs.pop(); } }
2282 NoTypeParameters => { }
2286 fn with_label_rib<F>(&mut self, f: F) where
2287 F: FnOnce(&mut Resolver),
2289 self.label_ribs.push(Rib::new(NormalRibKind));
2292 self.label_ribs.pop();
2296 fn with_constant_rib<F>(&mut self, f: F) where
2297 F: FnOnce(&mut Resolver),
2299 self.value_ribs.push(Rib::new(ConstantItemRibKind));
2300 self.type_ribs.push(Rib::new(ConstantItemRibKind));
2303 self.type_ribs.pop();
2304 self.value_ribs.pop();
2308 fn resolve_function(&mut self,
2310 declaration: &FnDecl,
2312 // Create a value rib for the function.
2313 self.value_ribs.push(Rib::new(rib_kind));
2315 // Create a label rib for the function.
2316 self.label_ribs.push(Rib::new(rib_kind));
2318 // Add each argument to the rib.
2319 let mut bindings_list = HashMap::new();
2320 for argument in &declaration.inputs {
2321 self.resolve_pattern(&*argument.pat,
2322 ArgumentIrrefutableMode,
2323 &mut bindings_list);
2325 self.visit_ty(&*argument.ty);
2327 debug!("(resolving function) recorded argument");
2329 visit::walk_fn_ret_ty(self, &declaration.output);
2331 // Resolve the function body.
2332 self.visit_block(&*block);
2334 debug!("(resolving function) leaving function");
2337 self.label_ribs.pop();
2338 self.value_ribs.pop();
2342 fn resolve_trait_reference(&mut self,
2346 -> Result<PathResolution, ()> {
2347 if let Some(path_res) = self.resolve_path(id, trait_path, path_depth, TypeNS, true) {
2348 if let DefTrait(_) = path_res.base_def {
2349 debug!("(resolving trait) found trait def: {:?}", path_res);
2354 ResolutionError::IsNotATrait(&*path_names_to_string(trait_path,
2358 // If it's a typedef, give a note
2359 if let DefTy(..) = path_res.base_def {
2360 self.session.span_note(trait_path.span,
2361 "`type` aliases cannot be used for traits");
2368 ResolutionError::UndeclaredTraitName(
2369 &*path_names_to_string(trait_path, path_depth))
2375 fn resolve_generics(&mut self, generics: &Generics) {
2376 for type_parameter in generics.ty_params.iter() {
2377 self.check_if_primitive_type_name(type_parameter.ident.name, type_parameter.span);
2379 for predicate in &generics.where_clause.predicates {
2381 &hir::WherePredicate::BoundPredicate(_) |
2382 &hir::WherePredicate::RegionPredicate(_) => {}
2383 &hir::WherePredicate::EqPredicate(ref eq_pred) => {
2384 let path_res = self.resolve_path(eq_pred.id, &eq_pred.path, 0, TypeNS, true);
2385 if let Some(PathResolution { base_def: DefTyParam(..), .. }) = path_res {
2386 self.record_def(eq_pred.id, path_res.unwrap());
2390 ResolutionError::UndeclaredAssociatedType);
2395 visit::walk_generics(self, generics);
2398 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2399 where F: FnOnce(&mut Resolver) -> T
2401 // Handle nested impls (inside fn bodies)
2402 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2403 let result = f(self);
2404 self.current_self_type = previous_value;
2408 fn with_optional_trait_ref<T, F>(&mut self,
2409 opt_trait_ref: Option<&TraitRef>,
2412 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2414 let mut new_val = None;
2415 let mut new_id = None;
2416 if let Some(trait_ref) = opt_trait_ref {
2417 if let Ok(path_res) = self.resolve_trait_reference(trait_ref.ref_id,
2418 &trait_ref.path, 0) {
2419 assert!(path_res.depth == 0);
2420 self.record_def(trait_ref.ref_id, path_res);
2421 new_val = Some((path_res.base_def.def_id(), trait_ref.clone()));
2422 new_id = Some(path_res.base_def.def_id());
2424 visit::walk_trait_ref(self, trait_ref);
2426 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2427 let result = f(self, new_id);
2428 self.current_trait_ref = original_trait_ref;
2432 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2433 where F: FnOnce(&mut Resolver)
2435 let mut self_type_rib = Rib::new(NormalRibKind);
2437 // plain insert (no renaming, types are not currently hygienic....)
2438 let name = special_names::type_self;
2439 self_type_rib.bindings.insert(name, DlDef(self_def));
2440 self.type_ribs.push(self_type_rib);
2443 self.type_ribs.pop();
2447 fn resolve_implementation(&mut self,
2448 generics: &Generics,
2449 opt_trait_reference: &Option<TraitRef>,
2452 impl_items: &[P<ImplItem>]) {
2453 // If applicable, create a rib for the type parameters.
2454 self.with_type_parameter_rib(HasTypeParameters(generics,
2458 // Resolve the type parameters.
2459 this.visit_generics(generics);
2461 // Resolve the trait reference, if necessary.
2462 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2463 // Resolve the self type.
2464 this.visit_ty(self_type);
2466 this.with_self_rib(DefSelfTy(trait_id, Some((item_id, self_type.id))), |this| {
2467 this.with_current_self_type(self_type, |this| {
2468 for impl_item in impl_items {
2469 match impl_item.node {
2470 ConstImplItem(..) => {
2471 // If this is a trait impl, ensure the const
2473 this.check_trait_item(impl_item.ident.name,
2475 |n, s| ResolutionError::ConstNotMemberOfTrait(n, s));
2476 this.with_constant_rib(|this| {
2477 visit::walk_impl_item(this, impl_item);
2480 MethodImplItem(ref sig, _) => {
2481 // If this is a trait impl, ensure the method
2483 this.check_trait_item(impl_item.ident.name,
2485 |n, s| ResolutionError::MethodNotMemberOfTrait(n, s));
2487 // We also need a new scope for the method-
2488 // specific type parameters.
2489 let type_parameters =
2490 HasTypeParameters(&sig.generics,
2493 this.with_type_parameter_rib(type_parameters, |this| {
2494 visit::walk_impl_item(this, impl_item);
2497 TypeImplItem(ref ty) => {
2498 // If this is a trait impl, ensure the type
2500 this.check_trait_item(impl_item.ident.name,
2502 |n, s| ResolutionError::TypeNotMemberOfTrait(n, s));
2514 fn check_trait_item<F>(&self, name: Name, span: Span, err: F)
2515 where F: FnOnce(Name, &str) -> ResolutionError {
2516 // If there is a TraitRef in scope for an impl, then the method must be in the trait.
2517 if let Some((did, ref trait_ref)) = self.current_trait_ref {
2518 if !self.trait_item_map.contains_key(&(name, did)) {
2519 let path_str = path_names_to_string(&trait_ref.path, 0);
2522 err(name, &*path_str));
2527 fn resolve_local(&mut self, local: &Local) {
2528 // Resolve the type.
2529 visit::walk_ty_opt(self, &local.ty);
2531 // Resolve the initializer.
2532 visit::walk_expr_opt(self, &local.init);
2534 // Resolve the pattern.
2535 self.resolve_pattern(&*local.pat,
2536 LocalIrrefutableMode,
2537 &mut HashMap::new());
2540 // build a map from pattern identifiers to binding-info's.
2541 // this is done hygienically. This could arise for a macro
2542 // that expands into an or-pattern where one 'x' was from the
2543 // user and one 'x' came from the macro.
2544 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2545 let mut result = HashMap::new();
2546 pat_bindings(&self.def_map, pat, |binding_mode, _id, sp, path1| {
2547 let name = mtwt::resolve(path1.node);
2548 result.insert(name, BindingInfo {
2550 binding_mode: binding_mode
2556 // check that all of the arms in an or-pattern have exactly the
2557 // same set of bindings, with the same binding modes for each.
2558 fn check_consistent_bindings(&mut self, arm: &Arm) {
2559 if arm.pats.is_empty() {
2562 let map_0 = self.binding_mode_map(&*arm.pats[0]);
2563 for (i, p) in arm.pats.iter().enumerate() {
2564 let map_i = self.binding_mode_map(&**p);
2566 for (&key, &binding_0) in &map_0 {
2567 match map_i.get(&key) {
2571 ResolutionError::VariableNotBoundInPattern(key,
2574 Some(binding_i) => {
2575 if binding_0.binding_mode != binding_i.binding_mode {
2578 ResolutionError::VariableBoundWithDifferentMode(key,
2586 for (&key, &binding) in &map_i {
2587 if !map_0.contains_key(&key) {
2590 ResolutionError::VariableNotBoundInParentPattern(key,
2597 fn resolve_arm(&mut self, arm: &Arm) {
2598 self.value_ribs.push(Rib::new(NormalRibKind));
2600 let mut bindings_list = HashMap::new();
2601 for pattern in &arm.pats {
2602 self.resolve_pattern(&**pattern, RefutableMode, &mut bindings_list);
2605 // This has to happen *after* we determine which
2606 // pat_idents are variants
2607 self.check_consistent_bindings(arm);
2609 visit::walk_expr_opt(self, &arm.guard);
2610 self.visit_expr(&*arm.body);
2613 self.value_ribs.pop();
2617 fn resolve_block(&mut self, block: &Block) {
2618 debug!("(resolving block) entering block");
2619 self.value_ribs.push(Rib::new(NormalRibKind));
2621 // Move down in the graph, if there's an anonymous module rooted here.
2622 let orig_module = self.current_module.clone();
2623 match orig_module.anonymous_children.borrow().get(&block.id) {
2624 None => { /* Nothing to do. */ }
2625 Some(anonymous_module) => {
2626 debug!("(resolving block) found anonymous module, moving \
2628 self.current_module = anonymous_module.clone();
2632 // Check for imports appearing after non-item statements.
2633 let mut found_non_item = false;
2634 for statement in &block.stmts {
2635 if let hir::StmtDecl(ref declaration, _) = statement.node {
2636 if let hir::DeclItem(ref i) = declaration.node {
2638 ItemExternCrate(_) | ItemUse(_) if found_non_item => {
2639 span_err!(self.session, i.span, E0154,
2640 "imports are not allowed after non-item statements");
2645 found_non_item = true
2648 found_non_item = true;
2652 // Descend into the block.
2653 visit::walk_block(self, block);
2657 self.current_module = orig_module;
2658 self.value_ribs.pop();
2660 debug!("(resolving block) leaving block");
2663 fn resolve_type(&mut self, ty: &Ty) {
2665 TyPath(ref maybe_qself, ref path) => {
2667 match self.resolve_possibly_assoc_item(ty.id,
2668 maybe_qself.as_ref(),
2672 // `<T>::a::b::c` is resolved by typeck alone.
2673 TypecheckRequired => {
2674 // Resolve embedded types.
2675 visit::walk_ty(self, ty);
2678 ResolveAttempt(resolution) => resolution,
2681 // This is a path in the type namespace. Walk through scopes
2685 // Write the result into the def map.
2686 debug!("(resolving type) writing resolution for `{}` \
2688 path_names_to_string(path, 0),
2690 self.record_def(ty.id, def);
2693 // Keep reporting some errors even if they're ignored above.
2694 self.resolve_path(ty.id, path, 0, TypeNS, true);
2696 let kind = if maybe_qself.is_some() {
2702 let self_type_name = special_idents::type_self.name;
2703 let is_invalid_self_type_name =
2704 path.segments.len() > 0 &&
2705 maybe_qself.is_none() &&
2706 path.segments[0].identifier.name == self_type_name;
2707 if is_invalid_self_type_name {
2710 ResolutionError::SelfUsedOutsideImplOrTrait);
2714 ResolutionError::UseOfUndeclared(
2716 &*path_names_to_string(path,
2725 // Resolve embedded types.
2726 visit::walk_ty(self, ty);
2729 fn resolve_pattern(&mut self,
2731 mode: PatternBindingMode,
2732 // Maps idents to the node ID for the (outermost)
2733 // pattern that binds them
2734 bindings_list: &mut HashMap<Name, NodeId>) {
2735 let pat_id = pattern.id;
2736 walk_pat(pattern, |pattern| {
2737 match pattern.node {
2738 PatIdent(binding_mode, ref path1, ref at_rhs) => {
2739 // The meaning of PatIdent with no type parameters
2740 // depends on whether an enum variant or unit-like struct
2741 // with that name is in scope. The probing lookup has to
2742 // be careful not to emit spurious errors. Only matching
2743 // patterns (match) can match nullary variants or
2744 // unit-like structs. For binding patterns (let
2745 // and the LHS of @-patterns), matching such a value is
2746 // simply disallowed (since it's rarely what you want).
2747 let const_ok = mode == RefutableMode && at_rhs.is_none();
2749 let ident = path1.node;
2750 let renamed = mtwt::resolve(ident);
2752 match self.resolve_bare_identifier_pattern(ident.name, pattern.span) {
2753 FoundStructOrEnumVariant(def, lp) if const_ok => {
2754 debug!("(resolving pattern) resolving `{}` to \
2755 struct or enum variant",
2758 self.enforce_default_binding_mode(
2762 self.record_def(pattern.id, PathResolution {
2768 FoundStructOrEnumVariant(..) => {
2772 ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(
2776 FoundConst(def, lp) if const_ok => {
2777 debug!("(resolving pattern) resolving `{}` to \
2781 self.enforce_default_binding_mode(
2785 self.record_def(pattern.id, PathResolution {
2795 ResolutionError::OnlyIrrefutablePatternsAllowedHere
2798 BareIdentifierPatternUnresolved => {
2799 debug!("(resolving pattern) binding `{}`",
2802 let def = DefLocal(pattern.id);
2804 // Record the definition so that later passes
2805 // will be able to distinguish variants from
2806 // locals in patterns.
2808 self.record_def(pattern.id, PathResolution {
2810 last_private: LastMod(AllPublic),
2814 // Add the binding to the local ribs, if it
2815 // doesn't already exist in the bindings list. (We
2816 // must not add it if it's in the bindings list
2817 // because that breaks the assumptions later
2818 // passes make about or-patterns.)
2819 if !bindings_list.contains_key(&renamed) {
2820 let this = &mut *self;
2821 let last_rib = this.value_ribs.last_mut().unwrap();
2822 last_rib.bindings.insert(renamed, DlDef(def));
2823 bindings_list.insert(renamed, pat_id);
2824 } else if mode == ArgumentIrrefutableMode &&
2825 bindings_list.contains_key(&renamed) {
2826 // Forbid duplicate bindings in the same
2831 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2832 &ident.name.as_str())
2834 } else if bindings_list.get(&renamed) ==
2836 // Then this is a duplicate variable in the
2837 // same disjunction, which is an error.
2841 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2842 &ident.name.as_str())
2845 // Else, not bound in the same pattern: do
2851 PatEnum(ref path, _) => {
2852 // This must be an enum variant, struct or const.
2854 match self.resolve_possibly_assoc_item(pat_id, None,
2857 // The below shouldn't happen because all
2858 // qualified paths should be in PatQPath.
2859 TypecheckRequired =>
2860 self.session.span_bug(
2862 "resolve_possibly_assoc_item claimed
2863 that a path in PatEnum requires typecheck
2864 to resolve, but qualified paths should be
2866 ResolveAttempt(resolution) => resolution,
2868 if let Some(path_res) = resolution {
2869 match path_res.base_def {
2870 DefVariant(..) | DefStruct(..) | DefConst(..) => {
2871 self.record_def(pattern.id, path_res);
2874 resolve_error(&self,
2876 ResolutionError::StaticVariableReference);
2879 // If anything ends up here entirely resolved,
2880 // it's an error. If anything ends up here
2881 // partially resolved, that's OK, because it may
2882 // be a `T::CONST` that typeck will resolve.
2883 if path_res.depth == 0 {
2887 ResolutionError::NotAnEnumVariantStructOrConst(
2896 let const_name = path.segments.last().unwrap()
2898 let traits = self.get_traits_containing_item(const_name);
2899 self.trait_map.insert(pattern.id, traits);
2900 self.record_def(pattern.id, path_res);
2908 ResolutionError::UnresolvedEnumVariantStructOrConst(
2909 &path.segments.last().unwrap().identifier.name.as_str())
2912 visit::walk_path(self, path);
2915 PatQPath(ref qself, ref path) => {
2916 // Associated constants only.
2918 match self.resolve_possibly_assoc_item(pat_id, Some(qself),
2921 TypecheckRequired => {
2922 // All `<T>::CONST` should end up here, and will
2923 // require use of the trait map to resolve
2924 // during typechecking.
2925 let const_name = path.segments.last().unwrap()
2927 let traits = self.get_traits_containing_item(const_name);
2928 self.trait_map.insert(pattern.id, traits);
2929 visit::walk_pat(self, pattern);
2932 ResolveAttempt(resolution) => resolution,
2934 if let Some(path_res) = resolution {
2935 match path_res.base_def {
2936 // All `<T as Trait>::CONST` should end up here, and
2937 // have the trait already selected.
2938 DefAssociatedConst(..) => {
2939 self.record_def(pattern.id, path_res);
2945 ResolutionError::NotAnAssociatedConst(
2946 &path.segments.last().unwrap().identifier.name.as_str()
2955 ResolutionError::UnresolvedAssociatedConst(
2956 &path.segments.last().unwrap().identifier.name.as_str()
2960 visit::walk_pat(self, pattern);
2963 PatStruct(ref path, _, _) => {
2964 match self.resolve_path(pat_id, path, 0, TypeNS, false) {
2965 Some(definition) => {
2966 self.record_def(pattern.id, definition);
2969 debug!("(resolving pattern) didn't find struct \
2970 def: {:?}", result);
2974 ResolutionError::DoesNotNameAStruct(
2975 &*path_names_to_string(path, 0))
2979 visit::walk_path(self, path);
2982 PatLit(_) | PatRange(..) => {
2983 visit::walk_pat(self, pattern);
2994 fn resolve_bare_identifier_pattern(&mut self, name: Name, span: Span)
2995 -> BareIdentifierPatternResolution {
2996 let module = self.current_module.clone();
2997 match self.resolve_item_in_lexical_scope(module,
3000 Success((target, _)) => {
3001 debug!("(resolve bare identifier pattern) succeeded in \
3002 finding {} at {:?}",
3004 target.bindings.value_def.borrow());
3005 match *target.bindings.value_def.borrow() {
3007 panic!("resolved name in the value namespace to a \
3008 set of name bindings with no def?!");
3011 // For the two success cases, this lookup can be
3012 // considered as not having a private component because
3013 // the lookup happened only within the current module.
3015 def @ DefVariant(..) | def @ DefStruct(..) => {
3016 return FoundStructOrEnumVariant(def, LastMod(AllPublic));
3018 def @ DefConst(..) | def @ DefAssociatedConst(..) => {
3019 return FoundConst(def, LastMod(AllPublic));
3024 ResolutionError::StaticVariableReference);
3025 return BareIdentifierPatternUnresolved;
3028 return BareIdentifierPatternUnresolved;
3036 panic!("unexpected indeterminate result");
3040 Some((span, msg)) => {
3041 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3046 debug!("(resolve bare identifier pattern) failed to find {}",
3048 return BareIdentifierPatternUnresolved;
3053 /// Handles paths that may refer to associated items
3054 fn resolve_possibly_assoc_item(&mut self,
3056 maybe_qself: Option<&hir::QSelf>,
3058 namespace: Namespace,
3060 -> AssocItemResolveResult
3062 let max_assoc_types;
3066 if qself.position == 0 {
3067 return TypecheckRequired;
3069 max_assoc_types = path.segments.len() - qself.position;
3070 // Make sure the trait is valid.
3071 let _ = self.resolve_trait_reference(id, path, max_assoc_types);
3074 max_assoc_types = path.segments.len();
3078 let mut resolution = self.with_no_errors(|this| {
3079 this.resolve_path(id, path, 0, namespace, check_ribs)
3081 for depth in 1..max_assoc_types {
3082 if resolution.is_some() {
3085 self.with_no_errors(|this| {
3086 resolution = this.resolve_path(id, path, depth,
3090 if let Some(DefMod(_)) = resolution.map(|r| r.base_def) {
3091 // A module is not a valid type or value.
3094 ResolveAttempt(resolution)
3097 /// If `check_ribs` is true, checks the local definitions first; i.e.
3098 /// doesn't skip straight to the containing module.
3099 /// Skips `path_depth` trailing segments, which is also reflected in the
3100 /// returned value. See `middle::def::PathResolution` for more info.
3101 pub fn resolve_path(&mut self,
3105 namespace: Namespace,
3106 check_ribs: bool) -> Option<PathResolution> {
3107 let span = path.span;
3108 let segments = &path.segments[..path.segments.len()-path_depth];
3110 let mk_res = |(def, lp)| PathResolution::new(def, lp, path_depth);
3113 let def = self.resolve_crate_relative_path(span, segments, namespace);
3114 return def.map(mk_res);
3117 // Try to find a path to an item in a module.
3118 let unqualified_def =
3119 self.resolve_identifier(segments.last().unwrap().identifier,
3124 if segments.len() <= 1 {
3125 return unqualified_def.map(mk_res);
3128 let def = self.resolve_module_relative_path(span, segments, namespace);
3129 match (def, unqualified_def) {
3130 (Some((ref d, _)), Some((ref ud, _))) if *d == *ud => {
3132 .add_lint(lint::builtin::UNUSED_QUALIFICATIONS,
3134 "unnecessary qualification".to_string());
3142 // Resolve a single identifier.
3143 fn resolve_identifier(&mut self,
3145 namespace: Namespace,
3148 -> Option<(Def, LastPrivate)> {
3149 // First, check to see whether the name is a primitive type.
3150 if namespace == TypeNS {
3151 if let Some(&prim_ty) = self.primitive_type_table
3153 .get(&identifier.name) {
3154 return Some((DefPrimTy(prim_ty), LastMod(AllPublic)));
3159 if let Some(def) = self.resolve_identifier_in_local_ribs(identifier,
3162 return Some((def, LastMod(AllPublic)));
3166 self.resolve_item_by_name_in_lexical_scope(identifier.name, namespace)
3169 // FIXME #4952: Merge me with resolve_name_in_module?
3170 fn resolve_definition_of_name_in_module(&mut self,
3171 containing_module: Rc<Module>,
3173 namespace: Namespace)
3175 // First, search children.
3176 build_reduced_graph::populate_module_if_necessary(self, &containing_module);
3178 match containing_module.children.borrow().get(&name) {
3179 Some(child_name_bindings) => {
3180 match child_name_bindings.def_for_namespace(namespace) {
3182 // Found it. Stop the search here.
3183 let p = child_name_bindings.defined_in_public_namespace(namespace);
3184 let lp = if p {LastMod(AllPublic)} else {
3185 LastMod(DependsOn(def.def_id()))
3187 return ChildNameDefinition(def, lp);
3195 // Next, search import resolutions.
3196 match containing_module.import_resolutions.borrow().get(&name) {
3197 Some(import_resolution) if import_resolution.is_public => {
3198 if let Some(target) = (*import_resolution).target_for_namespace(namespace) {
3199 match target.bindings.def_for_namespace(namespace) {
3202 let id = import_resolution.id(namespace);
3203 // track imports and extern crates as well
3204 self.used_imports.insert((id, namespace));
3205 self.record_import_use(id, name);
3206 match target.target_module.def_id.get() {
3207 Some(DefId{krate: kid, ..}) => {
3208 self.used_crates.insert(kid);
3212 return ImportNameDefinition(def, LastMod(AllPublic));
3215 // This can happen with external impls, due to
3216 // the imperfect way we read the metadata.
3221 Some(..) | None => {} // Continue.
3224 // Finally, search through external children.
3225 if namespace == TypeNS {
3226 if let Some(module) = containing_module.external_module_children.borrow()
3227 .get(&name).cloned() {
3228 if let Some(def_id) = module.def_id.get() {
3229 // track used crates
3230 self.used_crates.insert(def_id.krate);
3231 let lp = if module.is_public {LastMod(AllPublic)} else {
3232 LastMod(DependsOn(def_id))
3234 return ChildNameDefinition(DefMod(def_id), lp);
3239 return NoNameDefinition;
3242 // resolve a "module-relative" path, e.g. a::b::c
3243 fn resolve_module_relative_path(&mut self,
3245 segments: &[hir::PathSegment],
3246 namespace: Namespace)
3247 -> Option<(Def, LastPrivate)> {
3248 let module_path = segments.split_last().unwrap().1.iter()
3249 .map(|ps| ps.identifier.name)
3250 .collect::<Vec<_>>();
3252 let containing_module;
3254 let current_module = self.current_module.clone();
3255 match self.resolve_module_path(current_module,
3261 let (span, msg) = match err {
3262 Some((span, msg)) => (span, msg),
3264 let msg = format!("Use of undeclared type or module `{}`",
3265 names_to_string(&module_path));
3270 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3273 Indeterminate => panic!("indeterminate unexpected"),
3274 Success((resulting_module, resulting_last_private)) => {
3275 containing_module = resulting_module;
3276 last_private = resulting_last_private;
3280 let name = segments.last().unwrap().identifier.name;
3281 let def = match self.resolve_definition_of_name_in_module(containing_module.clone(),
3284 NoNameDefinition => {
3285 // We failed to resolve the name. Report an error.
3288 ChildNameDefinition(def, lp) | ImportNameDefinition(def, lp) => {
3289 (def, last_private.or(lp))
3292 if let Some(DefId{krate: kid, ..}) = containing_module.def_id.get() {
3293 self.used_crates.insert(kid);
3298 /// Invariant: This must be called only during main resolution, not during
3299 /// import resolution.
3300 fn resolve_crate_relative_path(&mut self,
3302 segments: &[hir::PathSegment],
3303 namespace: Namespace)
3304 -> Option<(Def, LastPrivate)> {
3305 let module_path = segments.split_last().unwrap().1.iter()
3306 .map(|ps| ps.identifier.name)
3307 .collect::<Vec<_>>();
3309 let root_module = self.graph_root.get_module();
3311 let containing_module;
3313 match self.resolve_module_path_from_root(root_module,
3318 LastMod(AllPublic)) {
3320 let (span, msg) = match err {
3321 Some((span, msg)) => (span, msg),
3323 let msg = format!("Use of undeclared module `::{}`",
3324 names_to_string(&module_path[..]));
3329 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3334 panic!("indeterminate unexpected");
3337 Success((resulting_module, resulting_last_private)) => {
3338 containing_module = resulting_module;
3339 last_private = resulting_last_private;
3343 let name = segments.last().unwrap().identifier.name;
3344 match self.resolve_definition_of_name_in_module(containing_module,
3347 NoNameDefinition => {
3348 // We failed to resolve the name. Report an error.
3351 ChildNameDefinition(def, lp) | ImportNameDefinition(def, lp) => {
3352 return Some((def, last_private.or(lp)));
3357 fn resolve_identifier_in_local_ribs(&mut self,
3359 namespace: Namespace,
3362 // Check the local set of ribs.
3363 let search_result = match namespace {
3365 let renamed = mtwt::resolve(ident);
3366 self.search_ribs(&self.value_ribs, renamed, span)
3369 let name = ident.name;
3370 self.search_ribs(&self.type_ribs, name, span)
3374 match search_result {
3375 Some(DlDef(def)) => {
3376 debug!("(resolving path in local ribs) resolved `{}` to local: {:?}",
3381 Some(DlField) | Some(DlImpl(_)) | None => {
3387 fn resolve_item_by_name_in_lexical_scope(&mut self,
3389 namespace: Namespace)
3390 -> Option<(Def, LastPrivate)> {
3392 let module = self.current_module.clone();
3393 match self.resolve_item_in_lexical_scope(module,
3396 Success((target, _)) => {
3397 match (*target.bindings).def_for_namespace(namespace) {
3399 // This can happen if we were looking for a type and
3400 // found a module instead. Modules don't have defs.
3401 debug!("(resolving item path by identifier in lexical \
3402 scope) failed to resolve {} after success...",
3407 debug!("(resolving item path in lexical scope) \
3408 resolved `{}` to item",
3410 // This lookup is "all public" because it only searched
3411 // for one identifier in the current module (couldn't
3412 // have passed through reexports or anything like that.
3413 return Some((def, LastMod(AllPublic)));
3418 panic!("unexpected indeterminate result");
3421 debug!("(resolving item path by identifier in lexical scope) \
3422 failed to resolve {}", name);
3424 if let Some((span, msg)) = err {
3425 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg))
3433 fn with_no_errors<T, F>(&mut self, f: F) -> T where
3434 F: FnOnce(&mut Resolver) -> T,
3436 self.emit_errors = false;
3438 self.emit_errors = true;
3442 fn find_fallback_in_self_type(&mut self, name: Name) -> FallbackSuggestion {
3443 fn extract_path_and_node_id(t: &Ty, allow: FallbackChecks)
3444 -> Option<(Path, NodeId, FallbackChecks)> {
3446 TyPath(None, ref path) => Some((path.clone(), t.id, allow)),
3447 TyPtr(ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, OnlyTraitAndStatics),
3448 TyRptr(_, ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, allow),
3449 // This doesn't handle the remaining `Ty` variants as they are not
3450 // that commonly the self_type, it might be interesting to provide
3451 // support for those in future.
3456 fn get_module(this: &mut Resolver, span: Span, name_path: &[ast::Name])
3457 -> Option<Rc<Module>> {
3458 let root = this.current_module.clone();
3459 let last_name = name_path.last().unwrap();
3461 if name_path.len() == 1 {
3462 match this.primitive_type_table.primitive_types.get(last_name) {
3465 match this.current_module.children.borrow().get(last_name) {
3466 Some(child) => child.get_module_if_available(),
3472 match this.resolve_module_path(root,
3477 Success((module, _)) => Some(module),
3483 fn is_static_method(this: &Resolver, did: DefId) -> bool {
3485 let sig = match this.ast_map.get(did.node) {
3486 hir_map::NodeTraitItem(trait_item) => match trait_item.node {
3487 hir::MethodTraitItem(ref sig, _) => sig,
3490 hir_map::NodeImplItem(impl_item) => match impl_item.node {
3491 hir::MethodImplItem(ref sig, _) => sig,
3496 sig.explicit_self.node == hir::SelfStatic
3498 csearch::is_static_method(&this.session.cstore, did)
3502 let (path, node_id, allowed) = match self.current_self_type {
3503 Some(ref ty) => match extract_path_and_node_id(ty, Everything) {
3505 None => return NoSuggestion,
3507 None => return NoSuggestion,
3510 if allowed == Everything {
3511 // Look for a field with the same name in the current self_type.
3512 match self.def_map.borrow().get(&node_id).map(|d| d.full_def()) {
3513 Some(DefTy(did, _)) |
3514 Some(DefStruct(did)) |
3515 Some(DefVariant(_, did, _)) => match self.structs.get(&did) {
3518 if fields.iter().any(|&field_name| name == field_name) {
3523 _ => {} // Self type didn't resolve properly
3527 let name_path = path.segments.iter().map(|seg| seg.identifier.name).collect::<Vec<_>>();
3529 // Look for a method in the current self type's impl module.
3530 if let Some(module) = get_module(self, path.span, &name_path) {
3531 if let Some(binding) = module.children.borrow().get(&name) {
3532 if let Some(DefMethod(did)) = binding.def_for_namespace(ValueNS) {
3533 if is_static_method(self, did) {
3534 return StaticMethod(path_names_to_string(&path, 0))
3536 if self.current_trait_ref.is_some() {
3538 } else if allowed == Everything {
3545 // Look for a method in the current trait.
3546 if let Some((trait_did, ref trait_ref)) = self.current_trait_ref {
3547 if let Some(&did) = self.trait_item_map.get(&(name, trait_did)) {
3548 if is_static_method(self, did) {
3549 return TraitMethod(path_names_to_string(&trait_ref.path, 0));
3559 fn find_best_match_for_name(&mut self, name: &str) -> Option<String> {
3560 let mut maybes: Vec<token::InternedString> = Vec::new();
3561 let mut values: Vec<usize> = Vec::new();
3563 for rib in self.value_ribs.iter().rev() {
3564 for (&k, _) in &rib.bindings {
3565 maybes.push(k.as_str());
3566 values.push(usize::MAX);
3570 let mut smallest = 0;
3571 for (i, other) in maybes.iter().enumerate() {
3572 values[i] = lev_distance(name, &other);
3574 if values[i] <= values[smallest] {
3579 // As a loose rule to avoid obviously incorrect suggestions, clamp the
3580 // maximum edit distance we will accept for a suggestion to one third of
3581 // the typo'd name's length.
3582 let max_distance = std::cmp::max(name.len(), 3) / 3;
3584 if !values.is_empty() &&
3585 values[smallest] <= max_distance &&
3586 name != &maybes[smallest][..] {
3588 Some(maybes[smallest].to_string())
3595 fn resolve_expr(&mut self, expr: &Expr) {
3596 // First, record candidate traits for this expression if it could
3597 // result in the invocation of a method call.
3599 self.record_candidate_traits_for_expr_if_necessary(expr);
3601 // Next, resolve the node.
3603 ExprPath(ref maybe_qself, ref path) => {
3605 match self.resolve_possibly_assoc_item(expr.id,
3606 maybe_qself.as_ref(),
3610 // `<T>::a::b::c` is resolved by typeck alone.
3611 TypecheckRequired => {
3612 let method_name = path.segments.last().unwrap().identifier.name;
3613 let traits = self.get_traits_containing_item(method_name);
3614 self.trait_map.insert(expr.id, traits);
3615 visit::walk_expr(self, expr);
3618 ResolveAttempt(resolution) => resolution,
3621 // This is a local path in the value namespace. Walk through
3622 // scopes looking for it.
3623 if let Some(path_res) = resolution {
3624 // Check if struct variant
3625 if let DefVariant(_, _, true) = path_res.base_def {
3626 let path_name = path_names_to_string(path, 0);
3630 ResolutionError::StructVariantUsedAsFunction(&*path_name));
3632 let msg = format!("did you mean to write: \
3633 `{} {{ /* fields */ }}`?",
3635 if self.emit_errors {
3636 self.session.fileline_help(expr.span, &msg);
3638 self.session.span_help(expr.span, &msg);
3641 // Write the result into the def map.
3642 debug!("(resolving expr) resolved `{}`",
3643 path_names_to_string(path, 0));
3645 // Partial resolutions will need the set of traits in scope,
3646 // so they can be completed during typeck.
3647 if path_res.depth != 0 {
3648 let method_name = path.segments.last().unwrap().identifier.name;
3649 let traits = self.get_traits_containing_item(method_name);
3650 self.trait_map.insert(expr.id, traits);
3653 self.record_def(expr.id, path_res);
3656 // Be helpful if the name refers to a struct
3657 // (The pattern matching def_tys where the id is in self.structs
3658 // matches on regular structs while excluding tuple- and enum-like
3659 // structs, which wouldn't result in this error.)
3660 let path_name = path_names_to_string(path, 0);
3661 let type_res = self.with_no_errors(|this| {
3662 this.resolve_path(expr.id, path, 0, TypeNS, false)
3664 match type_res.map(|r| r.base_def) {
3665 Some(DefTy(struct_id, _))
3666 if self.structs.contains_key(&struct_id) => {
3670 ResolutionError::StructVariantUsedAsFunction(
3674 let msg = format!("did you mean to write: \
3675 `{} {{ /* fields */ }}`?",
3677 if self.emit_errors {
3678 self.session.fileline_help(expr.span, &msg);
3680 self.session.span_help(expr.span, &msg);
3684 // Keep reporting some errors even if they're ignored above.
3685 self.resolve_path(expr.id, path, 0, ValueNS, true);
3687 let mut method_scope = false;
3688 self.value_ribs.iter().rev().all(|rib| {
3689 method_scope = match rib.kind {
3690 MethodRibKind => true,
3691 ItemRibKind | ConstantItemRibKind => false,
3692 _ => return true, // Keep advancing
3694 false // Stop advancing
3697 if method_scope && special_names::self_ == path_name {
3701 ResolutionError::SelfNotAvailableInStaticMethod
3704 let last_name = path.segments.last().unwrap().identifier.name;
3705 let mut msg = match self.find_fallback_in_self_type(last_name) {
3707 // limit search to 5 to reduce the number
3708 // of stupid suggestions
3709 self.find_best_match_for_name(&path_name)
3710 .map_or("".to_string(),
3711 |x| format!("`{}`", x))
3713 Field => format!("`self.{}`", path_name),
3716 format!("to call `self.{}`", path_name),
3717 TraitMethod(path_str) |
3718 StaticMethod(path_str) =>
3719 format!("to call `{}::{}`", path_str, path_name)
3722 if !msg.is_empty() {
3723 msg = format!(". Did you mean {}?", msg)
3728 ResolutionError::UnresolvedName(&*path_name,
3735 visit::walk_expr(self, expr);
3738 ExprStruct(ref path, _, _) => {
3739 // Resolve the path to the structure it goes to. We don't
3740 // check to ensure that the path is actually a structure; that
3741 // is checked later during typeck.
3742 match self.resolve_path(expr.id, path, 0, TypeNS, false) {
3743 Some(definition) => self.record_def(expr.id, definition),
3745 debug!("(resolving expression) didn't find struct def",);
3749 ResolutionError::DoesNotNameAStruct(
3750 &*path_names_to_string(path, 0))
3755 visit::walk_expr(self, expr);
3758 ExprLoop(_, Some(label)) | ExprWhile(_, _, Some(label)) => {
3759 self.with_label_rib(|this| {
3760 let def_like = DlDef(DefLabel(expr.id));
3763 let rib = this.label_ribs.last_mut().unwrap();
3764 let renamed = mtwt::resolve(label);
3765 rib.bindings.insert(renamed, def_like);
3768 visit::walk_expr(this, expr);
3772 ExprBreak(Some(label)) | ExprAgain(Some(label)) => {
3773 let renamed = mtwt::resolve(label.node);
3774 match self.search_label(renamed) {
3778 ResolutionError::UndeclaredLabel(&label.node.name.as_str()))
3780 Some(DlDef(def @ DefLabel(_))) => {
3781 // Since this def is a label, it is never read.
3782 self.record_def(expr.id, PathResolution {
3784 last_private: LastMod(AllPublic),
3789 self.session.span_bug(expr.span,
3790 "label wasn't mapped to a \
3797 visit::walk_expr(self, expr);
3802 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3804 ExprField(_, ident) => {
3805 // FIXME(#6890): Even though you can't treat a method like a
3806 // field, we need to add any trait methods we find that match
3807 // the field name so that we can do some nice error reporting
3808 // later on in typeck.
3809 let traits = self.get_traits_containing_item(ident.node.name);
3810 self.trait_map.insert(expr.id, traits);
3812 ExprMethodCall(ident, _, _) => {
3813 debug!("(recording candidate traits for expr) recording \
3816 let traits = self.get_traits_containing_item(ident.node.name);
3817 self.trait_map.insert(expr.id, traits);
3825 fn get_traits_containing_item(&mut self, name: Name) -> Vec<DefId> {
3826 debug!("(getting traits containing item) looking for '{}'",
3829 fn add_trait_info(found_traits: &mut Vec<DefId>,
3830 trait_def_id: DefId,
3832 debug!("(adding trait info) found trait {}:{} for method '{}'",
3836 found_traits.push(trait_def_id);
3839 let mut found_traits = Vec::new();
3840 let mut search_module = self.current_module.clone();
3842 // Look for the current trait.
3843 match self.current_trait_ref {
3844 Some((trait_def_id, _)) => {
3845 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3846 add_trait_info(&mut found_traits, trait_def_id, name);
3849 None => {} // Nothing to do.
3852 // Look for trait children.
3853 build_reduced_graph::populate_module_if_necessary(self, &search_module);
3856 for (_, child_names) in search_module.children.borrow().iter() {
3857 let def = match child_names.def_for_namespace(TypeNS) {
3861 let trait_def_id = match def {
3862 DefTrait(trait_def_id) => trait_def_id,
3865 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3866 add_trait_info(&mut found_traits, trait_def_id, name);
3871 // Look for imports.
3872 for (_, import) in search_module.import_resolutions.borrow().iter() {
3873 let target = match import.target_for_namespace(TypeNS) {
3875 Some(target) => target,
3877 let did = match target.bindings.def_for_namespace(TypeNS) {
3878 Some(DefTrait(trait_def_id)) => trait_def_id,
3879 Some(..) | None => continue,
3881 if self.trait_item_map.contains_key(&(name, did)) {
3882 add_trait_info(&mut found_traits, did, name);
3883 let id = import.type_id;
3884 self.used_imports.insert((id, TypeNS));
3885 let trait_name = self.get_trait_name(did);
3886 self.record_import_use(id, trait_name);
3887 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id.get() {
3888 self.used_crates.insert(kid);
3893 match search_module.parent_link.clone() {
3894 NoParentLink | ModuleParentLink(..) => break,
3895 BlockParentLink(parent_module, _) => {
3896 search_module = parent_module.upgrade().unwrap();
3904 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
3905 debug!("(recording def) recording {:?} for {}", resolution, node_id);
3906 assert!(match resolution.last_private {LastImport{..} => false, _ => true},
3907 "Import should only be used for `use` directives");
3909 if let Some(prev_res) = self.def_map.borrow_mut().insert(node_id, resolution) {
3910 let span = self.ast_map.opt_span(node_id).unwrap_or(codemap::DUMMY_SP);
3911 self.session.span_bug(span, &format!("path resolved multiple times \
3912 ({:?} before, {:?} now)",
3913 prev_res, resolution));
3917 fn enforce_default_binding_mode(&mut self,
3919 pat_binding_mode: BindingMode,
3921 match pat_binding_mode {
3922 BindByValue(_) => {}
3926 ResolutionError::CannotUseRefBindingModeWith(descr));
3934 // Diagnostics are not particularly efficient, because they're rarely
3938 #[allow(dead_code)] // useful for debugging
3939 fn dump_module(&mut self, module_: Rc<Module>) {
3940 debug!("Dump of module `{}`:", module_to_string(&*module_));
3942 debug!("Children:");
3943 build_reduced_graph::populate_module_if_necessary(self, &module_);
3944 for (&name, _) in module_.children.borrow().iter() {
3945 debug!("* {}", name);
3948 debug!("Import resolutions:");
3949 let import_resolutions = module_.import_resolutions.borrow();
3950 for (&name, import_resolution) in import_resolutions.iter() {
3952 match import_resolution.target_for_namespace(ValueNS) {
3953 None => { value_repr = "".to_string(); }
3955 value_repr = " value:?".to_string();
3961 match import_resolution.target_for_namespace(TypeNS) {
3962 None => { type_repr = "".to_string(); }
3964 type_repr = " type:?".to_string();
3969 debug!("* {}:{}{}", name, value_repr, type_repr);
3975 fn names_to_string(names: &[Name]) -> String {
3976 let mut first = true;
3977 let mut result = String::new();
3982 result.push_str("::")
3984 result.push_str(&name.as_str());
3989 fn path_names_to_string(path: &Path, depth: usize) -> String {
3990 let names: Vec<ast::Name> = path.segments[..path.segments.len()-depth]
3992 .map(|seg| seg.identifier.name)
3994 names_to_string(&names[..])
3997 /// A somewhat inefficient routine to obtain the name of a module.
3998 fn module_to_string(module: &Module) -> String {
3999 let mut names = Vec::new();
4001 fn collect_mod(names: &mut Vec<ast::Name>, module: &Module) {
4002 match module.parent_link {
4004 ModuleParentLink(ref module, name) => {
4006 collect_mod(names, &*module.upgrade().unwrap());
4008 BlockParentLink(ref module, _) => {
4009 // danger, shouldn't be ident?
4010 names.push(special_idents::opaque.name);
4011 collect_mod(names, &*module.upgrade().unwrap());
4015 collect_mod(&mut names, module);
4017 if names.is_empty() {
4018 return "???".to_string();
4020 names_to_string(&names.into_iter().rev().collect::<Vec<ast::Name>>())
4024 pub struct CrateMap {
4025 pub def_map: DefMap,
4026 pub freevars: RefCell<FreevarMap>,
4027 pub export_map: ExportMap,
4028 pub trait_map: TraitMap,
4029 pub external_exports: ExternalExports,
4030 pub glob_map: Option<GlobMap>
4033 #[derive(PartialEq,Copy, Clone)]
4034 pub enum MakeGlobMap {
4039 /// Entry point to crate resolution.
4040 pub fn resolve_crate<'a, 'tcx>(session: &'a Session,
4041 ast_map: &'a hir_map::Map<'tcx>,
4042 make_glob_map: MakeGlobMap)
4044 let krate = ast_map.krate();
4045 let mut resolver = create_resolver(session, ast_map, krate, make_glob_map, None);
4047 resolver.resolve_crate(krate);
4048 session.abort_if_errors();
4050 check_unused::check_crate(&mut resolver, krate);
4053 def_map: resolver.def_map,
4054 freevars: resolver.freevars,
4055 export_map: resolver.export_map,
4056 trait_map: resolver.trait_map,
4057 external_exports: resolver.external_exports,
4058 glob_map: if resolver.make_glob_map {
4059 Some(resolver.glob_map)
4066 /// Builds a name resolution walker to be used within this module,
4067 /// or used externally, with an optional callback function.
4069 /// The callback takes a &mut bool which allows callbacks to end a
4070 /// walk when set to true, passing through the rest of the walk, while
4071 /// preserving the ribs + current module. This allows resolve_path
4072 /// calls to be made with the correct scope info. The node in the
4073 /// callback corresponds to the current node in the walk.
4074 pub fn create_resolver<'a, 'tcx>(session: &'a Session,
4075 ast_map: &'a hir_map::Map<'tcx>,
4077 make_glob_map: MakeGlobMap,
4078 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>)
4079 -> Resolver<'a, 'tcx> {
4080 let mut resolver = Resolver::new(session, ast_map, krate.span, make_glob_map);
4082 resolver.callback = callback;
4084 build_reduced_graph::build_reduced_graph(&mut resolver, krate);
4085 session.abort_if_errors();
4087 resolve_imports::resolve_imports(&mut resolver);
4088 session.abort_if_errors();
4090 record_exports::record(&mut resolver);
4091 session.abort_if_errors();
4096 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }