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_hygienic;
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::{CRATE_NODE_ID, 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, item_id: ast::NodeId) {
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 self.visit_struct_def(&variant.node.def, variant.node.name, generics, item_id);
506 fn visit_foreign_item(&mut self, foreign_item: &hir::ForeignItem) {
507 execute_callback!(hir_map::Node::NodeForeignItem(foreign_item), self);
508 let type_parameters = match foreign_item.node {
509 ForeignItemFn(_, ref generics) => {
510 HasTypeParameters(generics, FnSpace, ItemRibKind)
512 ForeignItemStatic(..) => NoTypeParameters
514 self.with_type_parameter_rib(type_parameters, |this| {
515 visit::walk_foreign_item(this, foreign_item);
518 fn visit_fn(&mut self,
519 function_kind: FnKind<'v>,
520 declaration: &'v FnDecl,
524 let rib_kind = match function_kind {
525 FnKind::ItemFn(_, generics, _, _, _, _) => {
526 self.visit_generics(generics);
529 FnKind::Method(_, sig, _) => {
530 self.visit_generics(&sig.generics);
531 self.visit_explicit_self(&sig.explicit_self);
534 FnKind::Closure(..) => ClosureRibKind(node_id)
536 self.resolve_function(rib_kind, declaration, block);
540 type ErrorMessage = Option<(Span, String)>;
542 enum ResolveResult<T> {
543 Failed(ErrorMessage), // Failed to resolve the name, optional helpful error message.
544 Indeterminate, // Couldn't determine due to unresolved globs.
545 Success(T) // Successfully resolved the import.
548 impl<T> ResolveResult<T> {
549 fn success(&self) -> bool {
550 match *self { Success(_) => true, _ => false }
554 enum FallbackSuggestion {
559 StaticMethod(String),
563 #[derive(Copy, Clone)]
564 enum TypeParameters<'a> {
570 // Identifies the things that these parameters
571 // were declared on (type, fn, etc)
574 // The kind of the rib used for type parameters.
578 // The rib kind controls the translation of local
579 // definitions (`DefLocal`) to upvars (`DefUpvar`).
580 #[derive(Copy, Clone, Debug)]
582 // No translation needs to be applied.
585 // We passed through a closure scope at the given node ID.
586 // Translate upvars as appropriate.
587 ClosureRibKind(NodeId /* func id */),
589 // We passed through an impl or trait and are now in one of its
590 // methods. Allow references to ty params that impl or trait
591 // binds. Disallow any other upvars (including other ty params that are
595 // We passed through an item scope. Disallow upvars.
598 // We're in a constant item. Can't refer to dynamic stuff.
602 #[derive(Copy, Clone)]
603 enum UseLexicalScopeFlag {
608 enum ModulePrefixResult {
610 PrefixFound(Rc<Module>, usize)
613 #[derive(Copy, Clone)]
614 enum AssocItemResolveResult {
615 /// Syntax such as `<T>::item`, which can't be resolved until type
618 /// We should have been able to resolve the associated item.
619 ResolveAttempt(Option<PathResolution>),
622 #[derive(Copy, Clone, PartialEq)]
623 enum NameSearchType {
624 /// We're doing a name search in order to resolve a `use` directive.
627 /// We're doing a name search in order to resolve a path type, a path
628 /// expression, or a path pattern.
632 #[derive(Copy, Clone)]
633 enum BareIdentifierPatternResolution {
634 FoundStructOrEnumVariant(Def, LastPrivate),
635 FoundConst(Def, LastPrivate),
636 BareIdentifierPatternUnresolved
642 bindings: HashMap<Name, DefLike>,
647 fn new(kind: RibKind) -> Rib {
649 bindings: HashMap::new(),
655 /// The link from a module up to its nearest parent node.
656 #[derive(Clone,Debug)]
659 ModuleParentLink(Weak<Module>, Name),
660 BlockParentLink(Weak<Module>, NodeId)
663 /// The type of module this is.
664 #[derive(Copy, Clone, PartialEq, Debug)]
673 /// One node in the tree of modules.
675 parent_link: ParentLink,
676 def_id: Cell<Option<DefId>>,
677 kind: Cell<ModuleKind>,
680 children: RefCell<HashMap<Name, Rc<NameBindings>>>,
681 imports: RefCell<Vec<ImportDirective>>,
683 // The external module children of this node that were declared with
685 external_module_children: RefCell<HashMap<Name, Rc<Module>>>,
687 // The anonymous children of this node. Anonymous children are pseudo-
688 // modules that are implicitly created around items contained within
691 // For example, if we have this:
699 // There will be an anonymous module created around `g` with the ID of the
700 // entry block for `f`.
701 anonymous_children: RefCell<NodeMap<Rc<Module>>>,
703 // The status of resolving each import in this module.
704 import_resolutions: RefCell<HashMap<Name, ImportResolution>>,
706 // The number of unresolved globs that this module exports.
707 glob_count: Cell<usize>,
709 // The number of unresolved pub imports (both regular and globs) in this module
710 pub_count: Cell<usize>,
712 // The number of unresolved pub glob imports in this module
713 pub_glob_count: Cell<usize>,
715 // The index of the import we're resolving.
716 resolved_import_count: Cell<usize>,
718 // Whether this module is populated. If not populated, any attempt to
719 // access the children must be preceded with a
720 // `populate_module_if_necessary` call.
721 populated: Cell<bool>,
725 fn new(parent_link: ParentLink,
726 def_id: Option<DefId>,
732 parent_link: parent_link,
733 def_id: Cell::new(def_id),
734 kind: Cell::new(kind),
735 is_public: is_public,
736 children: RefCell::new(HashMap::new()),
737 imports: RefCell::new(Vec::new()),
738 external_module_children: RefCell::new(HashMap::new()),
739 anonymous_children: RefCell::new(NodeMap()),
740 import_resolutions: RefCell::new(HashMap::new()),
741 glob_count: Cell::new(0),
742 pub_count: Cell::new(0),
743 pub_glob_count: Cell::new(0),
744 resolved_import_count: Cell::new(0),
745 populated: Cell::new(!external),
749 fn all_imports_resolved(&self) -> bool {
750 if self.imports.borrow_state() == ::std::cell::BorrowState::Writing {
751 // it is currently being resolved ! so nope
754 self.imports.borrow().len() == self.resolved_import_count.get()
760 pub fn inc_glob_count(&self) {
761 self.glob_count.set(self.glob_count.get() + 1);
763 pub fn dec_glob_count(&self) {
764 assert!(self.glob_count.get() > 0);
765 self.glob_count.set(self.glob_count.get() - 1);
767 pub fn inc_pub_count(&self) {
768 self.pub_count.set(self.pub_count.get() + 1);
770 pub fn dec_pub_count(&self) {
771 assert!(self.pub_count.get() > 0);
772 self.pub_count.set(self.pub_count.get() - 1);
774 pub fn inc_pub_glob_count(&self) {
775 self.pub_glob_count.set(self.pub_glob_count.get() + 1);
777 pub fn dec_pub_glob_count(&self) {
778 assert!(self.pub_glob_count.get() > 0);
779 self.pub_glob_count.set(self.pub_glob_count.get() - 1);
783 impl fmt::Debug for Module {
784 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
785 write!(f, "{:?}, kind: {:?}, {}",
788 if self.is_public { "public" } else { "private" } )
794 flags DefModifiers: u8 {
795 const PUBLIC = 1 << 0,
796 const IMPORTABLE = 1 << 1,
800 // Records a possibly-private type definition.
801 #[derive(Clone,Debug)]
803 modifiers: DefModifiers, // see note in ImportResolution about how to use this
804 module_def: Option<Rc<Module>>,
805 type_def: Option<Def>,
806 type_span: Option<Span>
809 // Records a possibly-private value definition.
810 #[derive(Clone, Copy, Debug)]
812 modifiers: DefModifiers, // see note in ImportResolution about how to use this
814 value_span: Option<Span>,
817 // Records the definitions (at most one for each namespace) that a name is
820 pub struct NameBindings {
821 type_def: RefCell<Option<TypeNsDef>>, //< Meaning in type namespace.
822 value_def: RefCell<Option<ValueNsDef>>, //< Meaning in value namespace.
826 fn new() -> NameBindings {
828 type_def: RefCell::new(None),
829 value_def: RefCell::new(None),
833 /// Creates a new module in this set of name bindings.
834 fn define_module(&self,
835 parent_link: ParentLink,
836 def_id: Option<DefId>,
841 // Merges the module with the existing type def or creates a new one.
842 let modifiers = if is_public {
845 DefModifiers::empty()
846 } | DefModifiers::IMPORTABLE;
847 let module_ = Rc::new(Module::new(parent_link,
852 let type_def = self.type_def.borrow().clone();
855 *self.type_def.borrow_mut() = Some(TypeNsDef {
856 modifiers: modifiers,
857 module_def: Some(module_),
863 *self.type_def.borrow_mut() = Some(TypeNsDef {
864 modifiers: modifiers,
865 module_def: Some(module_),
867 type_def: type_def.type_def
873 /// Sets the kind of the module, creating a new one if necessary.
874 fn set_module_kind(&self,
875 parent_link: ParentLink,
876 def_id: Option<DefId>,
881 let modifiers = if is_public {
884 DefModifiers::empty()
885 } | DefModifiers::IMPORTABLE;
886 let type_def = self.type_def.borrow().clone();
889 let module = Module::new(parent_link,
894 *self.type_def.borrow_mut() = Some(TypeNsDef {
895 modifiers: modifiers,
896 module_def: Some(Rc::new(module)),
902 match type_def.module_def {
904 let module = Module::new(parent_link,
909 *self.type_def.borrow_mut() = Some(TypeNsDef {
910 modifiers: modifiers,
911 module_def: Some(Rc::new(module)),
912 type_def: type_def.type_def,
916 Some(module_def) => module_def.kind.set(kind),
922 /// Records a type definition.
923 fn define_type(&self, def: Def, sp: Span, modifiers: DefModifiers) {
924 debug!("defining type for def {:?} with modifiers {:?}", def, modifiers);
925 // Merges the type with the existing type def or creates a new one.
926 let type_def = self.type_def.borrow().clone();
929 *self.type_def.borrow_mut() = Some(TypeNsDef {
933 modifiers: modifiers,
937 *self.type_def.borrow_mut() = Some(TypeNsDef {
938 module_def: type_def.module_def,
941 modifiers: modifiers,
947 /// Records a value definition.
948 fn define_value(&self, def: Def, sp: Span, modifiers: DefModifiers) {
949 debug!("defining value for def {:?} with modifiers {:?}", def, modifiers);
950 *self.value_def.borrow_mut() = Some(ValueNsDef {
952 value_span: Some(sp),
953 modifiers: modifiers,
957 /// Returns the module node if applicable.
958 fn get_module_if_available(&self) -> Option<Rc<Module>> {
959 match *self.type_def.borrow() {
960 Some(ref type_def) => type_def.module_def.clone(),
965 /// Returns the module node. Panics if this node does not have a module
967 fn get_module(&self) -> Rc<Module> {
968 match self.get_module_if_available() {
970 panic!("get_module called on a node with no module \
973 Some(module_def) => module_def
977 fn defined_in_namespace(&self, namespace: Namespace) -> bool {
979 TypeNS => return self.type_def.borrow().is_some(),
980 ValueNS => return self.value_def.borrow().is_some()
984 fn defined_in_public_namespace(&self, namespace: Namespace) -> bool {
985 self.defined_in_namespace_with(namespace, DefModifiers::PUBLIC)
988 fn defined_in_namespace_with(&self, namespace: Namespace, modifiers: DefModifiers) -> bool {
990 TypeNS => match *self.type_def.borrow() {
991 Some(ref def) => def.modifiers.contains(modifiers), None => false
993 ValueNS => match *self.value_def.borrow() {
994 Some(ref def) => def.modifiers.contains(modifiers), None => false
999 fn def_for_namespace(&self, namespace: Namespace) -> Option<Def> {
1002 match *self.type_def.borrow() {
1004 Some(ref type_def) => {
1005 match type_def.type_def {
1006 Some(type_def) => Some(type_def),
1008 match type_def.module_def {
1009 Some(ref module) => {
1010 match module.def_id.get() {
1011 Some(did) => Some(DefMod(did)),
1023 match *self.value_def.borrow() {
1025 Some(value_def) => Some(value_def.def)
1031 fn span_for_namespace(&self, namespace: Namespace) -> Option<Span> {
1032 if self.defined_in_namespace(namespace) {
1035 match *self.type_def.borrow() {
1037 Some(ref type_def) => type_def.type_span
1041 match *self.value_def.borrow() {
1043 Some(ref value_def) => value_def.value_span
1052 fn is_public(&self, namespace: Namespace) -> bool {
1055 let type_def = self.type_def.borrow();
1056 type_def.as_ref().unwrap().modifiers.contains(DefModifiers::PUBLIC)
1059 let value_def = self.value_def.borrow();
1060 value_def.as_ref().unwrap().modifiers.contains(DefModifiers::PUBLIC)
1066 /// Interns the names of the primitive types.
1067 struct PrimitiveTypeTable {
1068 primitive_types: HashMap<Name, PrimTy>,
1071 impl PrimitiveTypeTable {
1072 fn new() -> PrimitiveTypeTable {
1073 let mut table = PrimitiveTypeTable {
1074 primitive_types: HashMap::new()
1077 table.intern("bool", TyBool);
1078 table.intern("char", TyChar);
1079 table.intern("f32", TyFloat(TyF32));
1080 table.intern("f64", TyFloat(TyF64));
1081 table.intern("isize", TyInt(TyIs));
1082 table.intern("i8", TyInt(TyI8));
1083 table.intern("i16", TyInt(TyI16));
1084 table.intern("i32", TyInt(TyI32));
1085 table.intern("i64", TyInt(TyI64));
1086 table.intern("str", TyStr);
1087 table.intern("usize", TyUint(TyUs));
1088 table.intern("u8", TyUint(TyU8));
1089 table.intern("u16", TyUint(TyU16));
1090 table.intern("u32", TyUint(TyU32));
1091 table.intern("u64", TyUint(TyU64));
1096 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1097 self.primitive_types.insert(token::intern(string), primitive_type);
1101 /// The main resolver class.
1102 pub struct Resolver<'a, 'tcx:'a> {
1103 session: &'a Session,
1105 ast_map: &'a hir_map::Map<'tcx>,
1107 graph_root: NameBindings,
1109 trait_item_map: FnvHashMap<(Name, DefId), DefId>,
1111 structs: FnvHashMap<DefId, Vec<Name>>,
1113 // The number of imports that are currently unresolved.
1114 unresolved_imports: usize,
1116 // The module that represents the current item scope.
1117 current_module: Rc<Module>,
1119 // The current set of local scopes, for values.
1120 // FIXME #4948: Reuse ribs to avoid allocation.
1121 value_ribs: Vec<Rib>,
1123 // The current set of local scopes, for types.
1124 type_ribs: Vec<Rib>,
1126 // The current set of local scopes, for labels.
1127 label_ribs: Vec<Rib>,
1129 // The trait that the current context can refer to.
1130 current_trait_ref: Option<(DefId, TraitRef)>,
1132 // The current self type if inside an impl (used for better errors).
1133 current_self_type: Option<Ty>,
1135 // The idents for the primitive types.
1136 primitive_type_table: PrimitiveTypeTable,
1139 freevars: RefCell<FreevarMap>,
1140 freevars_seen: RefCell<NodeMap<NodeMap<usize>>>,
1141 export_map: ExportMap,
1142 trait_map: TraitMap,
1143 external_exports: ExternalExports,
1145 // Whether or not to print error messages. Can be set to true
1146 // when getting additional info for error message suggestions,
1147 // so as to avoid printing duplicate errors
1150 make_glob_map: bool,
1151 // Maps imports to the names of items actually imported (this actually maps
1152 // all imports, but only glob imports are actually interesting).
1155 used_imports: HashSet<(NodeId, Namespace)>,
1156 used_crates: HashSet<CrateNum>,
1158 // Callback function for intercepting walks
1159 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>,
1160 // The intention is that the callback modifies this flag.
1161 // Once set, the resolver falls out of the walk, preserving the ribs.
1166 #[derive(PartialEq)]
1167 enum FallbackChecks {
1172 impl<'a, 'tcx> Resolver<'a, 'tcx> {
1173 fn new(session: &'a Session,
1174 ast_map: &'a hir_map::Map<'tcx>,
1176 make_glob_map: MakeGlobMap) -> Resolver<'a, 'tcx> {
1177 let graph_root = NameBindings::new();
1179 let root_def_id = ast_map.local_def_id(CRATE_NODE_ID);
1180 graph_root.define_module(NoParentLink,
1187 let current_module = graph_root.get_module();
1194 // The outermost module has def ID 0; this is not reflected in the
1197 graph_root: graph_root,
1199 trait_item_map: FnvHashMap(),
1200 structs: FnvHashMap(),
1202 unresolved_imports: 0,
1204 current_module: current_module,
1205 value_ribs: Vec::new(),
1206 type_ribs: Vec::new(),
1207 label_ribs: Vec::new(),
1209 current_trait_ref: None,
1210 current_self_type: None,
1212 primitive_type_table: PrimitiveTypeTable::new(),
1214 def_map: RefCell::new(NodeMap()),
1215 freevars: RefCell::new(NodeMap()),
1216 freevars_seen: RefCell::new(NodeMap()),
1217 export_map: NodeMap(),
1218 trait_map: NodeMap(),
1219 used_imports: HashSet::new(),
1220 used_crates: HashSet::new(),
1221 external_exports: DefIdSet(),
1224 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1225 glob_map: HashMap::new(),
1234 fn record_import_use(&mut self, import_id: NodeId, name: Name) {
1235 if !self.make_glob_map {
1238 if self.glob_map.contains_key(&import_id) {
1239 self.glob_map.get_mut(&import_id).unwrap().insert(name);
1243 let mut new_set = HashSet::new();
1244 new_set.insert(name);
1245 self.glob_map.insert(import_id, new_set);
1248 fn get_trait_name(&self, did: DefId) -> Name {
1249 if let Some(node_id) = self.ast_map.as_local_node_id(did) {
1250 self.ast_map.expect_item(node_id).name
1252 csearch::get_trait_name(&self.session.cstore, did)
1256 fn create_name_bindings_from_module(module: Rc<Module>) -> NameBindings {
1258 type_def: RefCell::new(Some(TypeNsDef {
1259 modifiers: DefModifiers::IMPORTABLE,
1260 module_def: Some(module),
1264 value_def: RefCell::new(None),
1268 /// Checks that the names of external crates don't collide with other
1269 /// external crates.
1270 fn check_for_conflicts_between_external_crates(&self,
1274 if module.external_module_children.borrow().contains_key(&name) {
1275 span_err!(self.session, span, E0259,
1276 "an external crate named `{}` has already \
1277 been imported into this module",
1282 /// Checks that the names of items don't collide with external crates.
1283 fn check_for_conflicts_between_external_crates_and_items(&self,
1287 if module.external_module_children.borrow().contains_key(&name) {
1288 span_err!(self.session, span, E0260,
1289 "the name `{}` conflicts with an external \
1290 crate that has been imported into this \
1296 /// Resolves the given module path from the given root `module_`.
1297 fn resolve_module_path_from_root(&mut self,
1298 module_: Rc<Module>,
1299 module_path: &[Name],
1302 name_search_type: NameSearchType,
1304 -> ResolveResult<(Rc<Module>, LastPrivate)> {
1305 fn search_parent_externals(needle: Name, module: &Rc<Module>)
1306 -> Option<Rc<Module>> {
1307 match module.external_module_children.borrow().get(&needle) {
1308 Some(_) => Some(module.clone()),
1309 None => match module.parent_link {
1310 ModuleParentLink(ref parent, _) => {
1311 search_parent_externals(needle, &parent.upgrade().unwrap())
1318 let mut search_module = module_;
1319 let mut index = index;
1320 let module_path_len = module_path.len();
1321 let mut closest_private = lp;
1323 // Resolve the module part of the path. This does not involve looking
1324 // upward though scope chains; we simply resolve names directly in
1325 // modules as we go.
1326 while index < module_path_len {
1327 let name = module_path[index];
1328 match self.resolve_name_in_module(search_module.clone(),
1334 let segment_name = name.as_str();
1335 let module_name = module_to_string(&*search_module);
1336 let mut span = span;
1337 let msg = if "???" == &module_name[..] {
1338 span.hi = span.lo + Pos::from_usize(segment_name.len());
1340 match search_parent_externals(name,
1341 &self.current_module) {
1343 let path_str = names_to_string(module_path);
1344 let target_mod_str = module_to_string(&*module);
1345 let current_mod_str =
1346 module_to_string(&*self.current_module);
1348 let prefix = if target_mod_str == current_mod_str {
1349 "self::".to_string()
1351 format!("{}::", target_mod_str)
1354 format!("Did you mean `{}{}`?", prefix, path_str)
1356 None => format!("Maybe a missing `extern crate {}`?",
1360 format!("Could not find `{}` in `{}`",
1365 return Failed(Some((span, msg)));
1367 Failed(err) => return Failed(err),
1369 debug!("(resolving module path for import) module \
1370 resolution is indeterminate: {}",
1372 return Indeterminate;
1374 Success((target, used_proxy)) => {
1375 // Check to see whether there are type bindings, and, if
1376 // so, whether there is a module within.
1377 match *target.bindings.type_def.borrow() {
1378 Some(ref type_def) => {
1379 match type_def.module_def {
1381 let msg = format!("Not a module `{}`",
1384 return Failed(Some((span, msg)));
1386 Some(ref module_def) => {
1387 search_module = module_def.clone();
1389 // track extern crates for unused_extern_crate lint
1390 if let Some(did) = module_def.def_id.get() {
1391 self.used_crates.insert(did.krate);
1394 // Keep track of the closest
1395 // private module used when
1396 // resolving this import chain.
1397 if !used_proxy && !search_module.is_public {
1398 if let Some(did) = search_module.def_id.get() {
1399 closest_private = LastMod(DependsOn(did));
1406 // There are no type bindings at all.
1407 let msg = format!("Not a module `{}`",
1409 return Failed(Some((span, msg)));
1418 return Success((search_module, closest_private));
1421 /// Attempts to resolve the module part of an import directive or path
1422 /// rooted at the given module.
1424 /// On success, returns the resolved module, and the closest *private*
1425 /// module found to the destination when resolving this path.
1426 fn resolve_module_path(&mut self,
1427 module_: Rc<Module>,
1428 module_path: &[Name],
1429 use_lexical_scope: UseLexicalScopeFlag,
1431 name_search_type: NameSearchType)
1432 -> ResolveResult<(Rc<Module>, LastPrivate)> {
1433 let module_path_len = module_path.len();
1434 assert!(module_path_len > 0);
1436 debug!("(resolving module path for import) processing `{}` rooted at `{}`",
1437 names_to_string(module_path),
1438 module_to_string(&*module_));
1440 // Resolve the module prefix, if any.
1441 let module_prefix_result = self.resolve_module_prefix(module_.clone(),
1447 match module_prefix_result {
1449 let mpath = names_to_string(module_path);
1450 let mpath = &mpath[..];
1451 match mpath.rfind(':') {
1453 let msg = format!("Could not find `{}` in `{}`",
1454 // idx +- 1 to account for the
1455 // colons on either side
1458 return Failed(Some((span, msg)));
1465 Failed(err) => return Failed(err),
1467 debug!("(resolving module path for import) indeterminate; \
1469 return Indeterminate;
1471 Success(NoPrefixFound) => {
1472 // There was no prefix, so we're considering the first element
1473 // of the path. How we handle this depends on whether we were
1474 // instructed to use lexical scope or not.
1475 match use_lexical_scope {
1476 DontUseLexicalScope => {
1477 // This is a crate-relative path. We will start the
1478 // resolution process at index zero.
1479 search_module = self.graph_root.get_module();
1481 last_private = LastMod(AllPublic);
1483 UseLexicalScope => {
1484 // This is not a crate-relative path. We resolve the
1485 // first component of the path in the current lexical
1486 // scope and then proceed to resolve below that.
1487 match self.resolve_module_in_lexical_scope(module_,
1489 Failed(err) => return Failed(err),
1491 debug!("(resolving module path for import) \
1492 indeterminate; bailing");
1493 return Indeterminate;
1495 Success(containing_module) => {
1496 search_module = containing_module;
1498 last_private = LastMod(AllPublic);
1504 Success(PrefixFound(ref containing_module, index)) => {
1505 search_module = containing_module.clone();
1506 start_index = index;
1507 last_private = LastMod(DependsOn(containing_module.def_id
1513 self.resolve_module_path_from_root(search_module,
1521 /// Invariant: This must only be called during main resolution, not during
1522 /// import resolution.
1523 fn resolve_item_in_lexical_scope(&mut self,
1524 module_: Rc<Module>,
1526 namespace: Namespace)
1527 -> ResolveResult<(Target, bool)> {
1528 debug!("(resolving item in lexical scope) resolving `{}` in \
1529 namespace {:?} in `{}`",
1532 module_to_string(&*module_));
1534 // The current module node is handled specially. First, check for
1535 // its immediate children.
1536 build_reduced_graph::populate_module_if_necessary(self, &module_);
1538 match module_.children.borrow().get(&name) {
1540 if name_bindings.defined_in_namespace(namespace) => {
1541 debug!("top name bindings succeeded");
1542 return Success((Target::new(module_.clone(),
1543 name_bindings.clone(),
1547 Some(_) | None => { /* Not found; continue. */ }
1550 // Now check for its import directives. We don't have to have resolved
1551 // all its imports in the usual way; this is because chains of
1552 // adjacent import statements are processed as though they mutated the
1554 if let Some(import_resolution) = module_.import_resolutions.borrow().get(&name) {
1555 match (*import_resolution).target_for_namespace(namespace) {
1557 // Not found; continue.
1558 debug!("(resolving item in lexical scope) found \
1559 import resolution, but not in namespace {:?}",
1563 debug!("(resolving item in lexical scope) using \
1564 import resolution");
1565 // track used imports and extern crates as well
1566 let id = import_resolution.id(namespace);
1567 self.used_imports.insert((id, namespace));
1568 self.record_import_use(id, name);
1569 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id.get() {
1570 self.used_crates.insert(kid);
1572 return Success((target, false));
1577 // Search for external modules.
1578 if namespace == TypeNS {
1579 // FIXME (21114): In principle unclear `child` *has* to be lifted.
1580 let child = module_.external_module_children.borrow().get(&name).cloned();
1581 if let Some(module) = child {
1583 Rc::new(Resolver::create_name_bindings_from_module(module));
1584 debug!("lower name bindings succeeded");
1585 return Success((Target::new(module_,
1592 // Finally, proceed up the scope chain looking for parent modules.
1593 let mut search_module = module_;
1595 // Go to the next parent.
1596 match search_module.parent_link.clone() {
1598 // No more parents. This module was unresolved.
1599 debug!("(resolving item in lexical scope) unresolved \
1601 return Failed(None);
1603 ModuleParentLink(parent_module_node, _) => {
1604 match search_module.kind.get() {
1605 NormalModuleKind => {
1606 // We stop the search here.
1607 debug!("(resolving item in lexical \
1608 scope) unresolved module: not \
1609 searching through module \
1611 return Failed(None);
1616 AnonymousModuleKind => {
1617 search_module = parent_module_node.upgrade().unwrap();
1621 BlockParentLink(ref parent_module_node, _) => {
1622 search_module = parent_module_node.upgrade().unwrap();
1626 // Resolve the name in the parent module.
1627 match self.resolve_name_in_module(search_module.clone(),
1632 Failed(Some((span, msg))) => {
1633 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
1635 Failed(None) => (), // Continue up the search chain.
1637 // We couldn't see through the higher scope because of an
1638 // unresolved import higher up. Bail.
1640 debug!("(resolving item in lexical scope) indeterminate \
1641 higher scope; bailing");
1642 return Indeterminate;
1644 Success((target, used_reexport)) => {
1645 // We found the module.
1646 debug!("(resolving item in lexical scope) found name \
1648 return Success((target, used_reexport));
1654 /// Resolves a module name in the current lexical scope.
1655 fn resolve_module_in_lexical_scope(&mut self,
1656 module_: Rc<Module>,
1658 -> ResolveResult<Rc<Module>> {
1659 // If this module is an anonymous module, resolve the item in the
1660 // lexical scope. Otherwise, resolve the item from the crate root.
1661 let resolve_result = self.resolve_item_in_lexical_scope(module_, name, TypeNS);
1662 match resolve_result {
1663 Success((target, _)) => {
1664 let bindings = &*target.bindings;
1665 match *bindings.type_def.borrow() {
1666 Some(ref type_def) => {
1667 match type_def.module_def {
1669 debug!("!!! (resolving module in lexical \
1670 scope) module wasn't actually a \
1672 return Failed(None);
1674 Some(ref module_def) => {
1675 return Success(module_def.clone());
1680 debug!("!!! (resolving module in lexical scope) module
1681 wasn't actually a module!");
1682 return Failed(None);
1687 debug!("(resolving module in lexical scope) indeterminate; \
1689 return Indeterminate;
1692 debug!("(resolving module in lexical scope) failed to resolve");
1698 /// Returns the nearest normal module parent of the given module.
1699 fn get_nearest_normal_module_parent(&mut self, module_: Rc<Module>)
1700 -> Option<Rc<Module>> {
1701 let mut module_ = module_;
1703 match module_.parent_link.clone() {
1704 NoParentLink => return None,
1705 ModuleParentLink(new_module, _) |
1706 BlockParentLink(new_module, _) => {
1707 let new_module = new_module.upgrade().unwrap();
1708 match new_module.kind.get() {
1709 NormalModuleKind => return Some(new_module),
1713 AnonymousModuleKind => module_ = new_module,
1720 /// Returns the nearest normal module parent of the given module, or the
1721 /// module itself if it is a normal module.
1722 fn get_nearest_normal_module_parent_or_self(&mut self, module_: Rc<Module>)
1724 match module_.kind.get() {
1725 NormalModuleKind => return module_,
1729 AnonymousModuleKind => {
1730 match self.get_nearest_normal_module_parent(module_.clone()) {
1732 Some(new_module) => new_module
1738 /// Resolves a "module prefix". A module prefix is one or both of (a) `self::`;
1739 /// (b) some chain of `super::`.
1740 /// grammar: (SELF MOD_SEP ) ? (SUPER MOD_SEP) *
1741 fn resolve_module_prefix(&mut self,
1742 module_: Rc<Module>,
1743 module_path: &[Name])
1744 -> ResolveResult<ModulePrefixResult> {
1745 // Start at the current module if we see `self` or `super`, or at the
1746 // top of the crate otherwise.
1747 let mut i = match &*module_path[0].as_str() {
1750 _ => return Success(NoPrefixFound),
1752 let mut containing_module = self.get_nearest_normal_module_parent_or_self(module_);
1754 // Now loop through all the `super`s we find.
1755 while i < module_path.len() && "super" == module_path[i].as_str() {
1756 debug!("(resolving module prefix) resolving `super` at {}",
1757 module_to_string(&*containing_module));
1758 match self.get_nearest_normal_module_parent(containing_module) {
1759 None => return Failed(None),
1760 Some(new_module) => {
1761 containing_module = new_module;
1767 debug!("(resolving module prefix) finished resolving prefix at {}",
1768 module_to_string(&*containing_module));
1770 return Success(PrefixFound(containing_module, i));
1773 /// Attempts to resolve the supplied name in the given module for the
1774 /// given namespace. If successful, returns the target corresponding to
1777 /// The boolean returned on success is an indicator of whether this lookup
1778 /// passed through a public re-export proxy.
1779 fn resolve_name_in_module(&mut self,
1780 module_: Rc<Module>,
1782 namespace: Namespace,
1783 name_search_type: NameSearchType,
1784 allow_private_imports: bool)
1785 -> ResolveResult<(Target, bool)> {
1786 debug!("(resolving name in module) resolving `{}` in `{}`",
1788 module_to_string(&*module_));
1790 // First, check the direct children of the module.
1791 build_reduced_graph::populate_module_if_necessary(self, &module_);
1793 match module_.children.borrow().get(&name) {
1795 if name_bindings.defined_in_namespace(namespace) => {
1796 debug!("(resolving name in module) found node as child");
1797 return Success((Target::new(module_.clone(),
1798 name_bindings.clone(),
1807 // Next, check the module's imports if necessary.
1809 // If this is a search of all imports, we should be done with glob
1810 // resolution at this point.
1811 if name_search_type == PathSearch {
1812 assert_eq!(module_.glob_count.get(), 0);
1815 // Check the list of resolved imports.
1816 match module_.import_resolutions.borrow().get(&name) {
1817 Some(import_resolution) if allow_private_imports ||
1818 import_resolution.is_public => {
1820 if import_resolution.is_public &&
1821 import_resolution.outstanding_references != 0 {
1822 debug!("(resolving name in module) import \
1823 unresolved; bailing out");
1824 return Indeterminate;
1826 match import_resolution.target_for_namespace(namespace) {
1828 debug!("(resolving name in module) name found, \
1829 but not in namespace {:?}",
1833 debug!("(resolving name in module) resolved to \
1835 // track used imports and extern crates as well
1836 let id = import_resolution.id(namespace);
1837 self.used_imports.insert((id, namespace));
1838 self.record_import_use(id, name);
1839 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id.get() {
1840 self.used_crates.insert(kid);
1842 return Success((target, true));
1846 Some(..) | None => {} // Continue.
1849 // Finally, search through external children.
1850 if namespace == TypeNS {
1851 // FIXME (21114): In principle unclear `child` *has* to be lifted.
1852 let child = module_.external_module_children.borrow().get(&name).cloned();
1853 if let Some(module) = child {
1855 Rc::new(Resolver::create_name_bindings_from_module(module));
1856 return Success((Target::new(module_,
1863 // We're out of luck.
1864 debug!("(resolving name in module) failed to resolve `{}`",
1866 return Failed(None);
1869 fn report_unresolved_imports(&mut self, module_: Rc<Module>) {
1870 let index = module_.resolved_import_count.get();
1871 let imports = module_.imports.borrow();
1872 let import_count = imports.len();
1873 if index != import_count {
1875 (*imports)[index].span,
1876 ResolutionError::UnresolvedImport(None));
1879 // Descend into children and anonymous children.
1880 build_reduced_graph::populate_module_if_necessary(self, &module_);
1882 for (_, child_node) in module_.children.borrow().iter() {
1883 match child_node.get_module_if_available() {
1887 Some(child_module) => {
1888 self.report_unresolved_imports(child_module);
1893 for (_, module_) in module_.anonymous_children.borrow().iter() {
1894 self.report_unresolved_imports(module_.clone());
1900 // We maintain a list of value ribs and type ribs.
1902 // Simultaneously, we keep track of the current position in the module
1903 // graph in the `current_module` pointer. When we go to resolve a name in
1904 // the value or type namespaces, we first look through all the ribs and
1905 // then query the module graph. When we resolve a name in the module
1906 // namespace, we can skip all the ribs (since nested modules are not
1907 // allowed within blocks in Rust) and jump straight to the current module
1910 // Named implementations are handled separately. When we find a method
1911 // call, we consult the module node to find all of the implementations in
1912 // scope. This information is lazily cached in the module node. We then
1913 // generate a fake "implementation scope" containing all the
1914 // implementations thus found, for compatibility with old resolve pass.
1916 fn with_scope<F>(&mut self, name: Option<Name>, f: F) where
1917 F: FnOnce(&mut Resolver),
1919 let orig_module = self.current_module.clone();
1921 // Move down in the graph.
1927 build_reduced_graph::populate_module_if_necessary(self, &orig_module);
1929 match orig_module.children.borrow().get(&name) {
1931 debug!("!!! (with scope) didn't find `{}` in `{}`",
1933 module_to_string(&*orig_module));
1935 Some(name_bindings) => {
1936 match (*name_bindings).get_module_if_available() {
1938 debug!("!!! (with scope) didn't find module \
1941 module_to_string(&*orig_module));
1944 self.current_module = module_;
1954 self.current_module = orig_module;
1957 /// Wraps the given definition in the appropriate number of `DefUpvar`
1963 -> Option<DefLike> {
1964 let mut def = match def_like {
1966 _ => return Some(def_like)
1970 self.session.span_bug(span,
1971 &format!("unexpected {:?} in bindings", def))
1973 DefLocal(_, node_id) => {
1977 // Nothing to do. Continue.
1979 ClosureRibKind(function_id) => {
1981 let node_def_id = self.ast_map.local_def_id(node_id);
1983 let mut seen = self.freevars_seen.borrow_mut();
1984 let seen = seen.entry(function_id).or_insert_with(|| NodeMap());
1985 if let Some(&index) = seen.get(&node_id) {
1986 def = DefUpvar(node_def_id, node_id, index, function_id);
1989 let mut freevars = self.freevars.borrow_mut();
1990 let vec = freevars.entry(function_id)
1991 .or_insert_with(|| vec![]);
1992 let depth = vec.len();
1993 vec.push(Freevar { def: prev_def, span: span });
1995 def = DefUpvar(node_def_id, node_id, depth, function_id);
1996 seen.insert(node_id, depth);
1998 ItemRibKind | MethodRibKind => {
1999 // This was an attempt to access an upvar inside a
2000 // named function item. This is not allowed, so we
2005 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem
2009 ConstantItemRibKind => {
2010 // Still doesn't deal with upvars
2014 ResolutionError::AttemptToUseNonConstantValueInConstant
2021 DefTyParam(..) | DefSelfTy(..) => {
2024 NormalRibKind | MethodRibKind | ClosureRibKind(..) => {
2025 // Nothing to do. Continue.
2028 // This was an attempt to use a type parameter outside
2033 ResolutionError::TypeParametersFromOuterFunction);
2036 ConstantItemRibKind => {
2038 resolve_error(self, span, ResolutionError::OuterTypeParameterContext);
2049 /// Searches the current set of local scopes and
2050 /// applies translations for closures.
2051 fn search_ribs(&self,
2055 -> Option<DefLike> {
2056 // FIXME #4950: Try caching?
2058 for (i, rib) in ribs.iter().enumerate().rev() {
2059 if let Some(def_like) = rib.bindings.get(&name).cloned() {
2060 return self.upvarify(&ribs[i + 1..], def_like, span);
2067 /// Searches the current set of local scopes for labels.
2068 /// Stops after meeting a closure.
2069 fn search_label(&self, name: Name) -> Option<DefLike> {
2070 for rib in self.label_ribs.iter().rev() {
2076 // Do not resolve labels across function boundary
2080 let result = rib.bindings.get(&name).cloned();
2081 if result.is_some() {
2088 fn resolve_crate(&mut self, krate: &hir::Crate) {
2089 debug!("(resolving crate) starting");
2091 visit::walk_crate(self, krate);
2094 fn check_if_primitive_type_name(&self, name: Name, span: Span) {
2095 if let Some(_) = self.primitive_type_table.primitive_types.get(&name) {
2096 span_err!(self.session, span, E0317,
2097 "user-defined types or type parameters cannot shadow the primitive types");
2101 fn resolve_item(&mut self, item: &Item) {
2102 let name = item.name;
2104 debug!("(resolving item) resolving {}",
2108 ItemEnum(_, ref generics) |
2109 ItemTy(_, ref generics) |
2110 ItemStruct(_, ref generics) => {
2111 self.check_if_primitive_type_name(name, item.span);
2113 self.with_type_parameter_rib(HasTypeParameters(generics,
2116 |this| visit::walk_item(this, item));
2118 ItemFn(_, _, _, _, ref generics, _) => {
2119 self.with_type_parameter_rib(HasTypeParameters(generics,
2122 |this| visit::walk_item(this, item));
2125 ItemDefaultImpl(_, ref trait_ref) => {
2126 self.with_optional_trait_ref(Some(trait_ref), |_, _| {});
2133 ref impl_items) => {
2134 self.resolve_implementation(generics,
2141 ItemTrait(_, ref generics, ref bounds, ref trait_items) => {
2142 self.check_if_primitive_type_name(name, item.span);
2144 // Create a new rib for the trait-wide type parameters.
2145 self.with_type_parameter_rib(HasTypeParameters(generics,
2149 let local_def_id = this.ast_map.local_def_id(item.id);
2150 this.with_self_rib(DefSelfTy(Some(local_def_id), None), |this| {
2151 this.visit_generics(generics);
2152 walk_list!(this, visit_ty_param_bound, bounds);
2154 for trait_item in trait_items {
2155 match trait_item.node {
2156 hir::ConstTraitItem(_, ref default) => {
2157 // Only impose the restrictions of
2158 // ConstRibKind if there's an actual constant
2159 // expression in a provided default.
2160 if default.is_some() {
2161 this.with_constant_rib(|this| {
2162 visit::walk_trait_item(this, trait_item)
2165 visit::walk_trait_item(this, trait_item)
2168 hir::MethodTraitItem(ref sig, _) => {
2169 let type_parameters =
2170 HasTypeParameters(&sig.generics,
2173 this.with_type_parameter_rib(type_parameters, |this| {
2174 visit::walk_trait_item(this, trait_item)
2177 hir::TypeTraitItem(..) => {
2178 this.check_if_primitive_type_name(trait_item.name,
2180 this.with_type_parameter_rib(NoTypeParameters, |this| {
2181 visit::walk_trait_item(this, trait_item)
2190 ItemMod(_) | ItemForeignMod(_) => {
2191 self.with_scope(Some(name), |this| {
2192 visit::walk_item(this, item);
2196 ItemConst(..) | ItemStatic(..) => {
2197 self.with_constant_rib(|this| {
2198 visit::walk_item(this, item);
2202 ItemUse(ref view_path) => {
2203 // check for imports shadowing primitive types
2204 let check_rename = |this: &Self, id, name| {
2205 match this.def_map.borrow().get(&id).map(|d| d.full_def()) {
2206 Some(DefTy(..)) | Some(DefStruct(..)) | Some(DefTrait(..)) | None => {
2207 this.check_if_primitive_type_name(name, item.span);
2213 match view_path.node {
2214 hir::ViewPathSimple(name, _) => {
2215 check_rename(self, item.id, name);
2217 hir::ViewPathList(ref prefix, ref items) => {
2219 if let Some(name) = item.node.rename() {
2220 check_rename(self, item.node.id(), name);
2224 // Resolve prefix of an import with empty braces (issue #28388)
2225 if items.is_empty() && !prefix.segments.is_empty() {
2226 match self.resolve_crate_relative_path(prefix.span,
2229 Some((def, lp)) => self.record_def(item.id,
2230 PathResolution::new(def, lp, 0)),
2234 ResolutionError::FailedToResolve(
2235 &path_names_to_string(prefix, 0)));
2244 ItemExternCrate(_) => {
2245 // do nothing, these are just around to be encoded
2250 fn with_type_parameter_rib<F>(&mut self, type_parameters: TypeParameters, f: F) where
2251 F: FnOnce(&mut Resolver),
2253 match type_parameters {
2254 HasTypeParameters(generics, space, rib_kind) => {
2255 let mut function_type_rib = Rib::new(rib_kind);
2256 let mut seen_bindings = HashSet::new();
2257 for (index, type_parameter) in generics.ty_params.iter().enumerate() {
2258 let name = type_parameter.name;
2259 debug!("with_type_parameter_rib: {}", type_parameter.id);
2261 if seen_bindings.contains(&name) {
2263 type_parameter.span,
2264 ResolutionError::NameAlreadyUsedInTypeParameterList(
2268 seen_bindings.insert(name);
2270 // plain insert (no renaming)
2271 function_type_rib.bindings.insert(name,
2272 DlDef(DefTyParam(space,
2274 self.ast_map.local_def_id(type_parameter.id),
2277 self.type_ribs.push(function_type_rib);
2280 NoTypeParameters => {
2287 match type_parameters {
2288 HasTypeParameters(..) => { if !self.resolved { self.type_ribs.pop(); } }
2289 NoTypeParameters => { }
2293 fn with_label_rib<F>(&mut self, f: F) where
2294 F: FnOnce(&mut Resolver),
2296 self.label_ribs.push(Rib::new(NormalRibKind));
2299 self.label_ribs.pop();
2303 fn with_constant_rib<F>(&mut self, f: F) where
2304 F: FnOnce(&mut Resolver),
2306 self.value_ribs.push(Rib::new(ConstantItemRibKind));
2307 self.type_ribs.push(Rib::new(ConstantItemRibKind));
2310 self.type_ribs.pop();
2311 self.value_ribs.pop();
2315 fn resolve_function(&mut self,
2317 declaration: &FnDecl,
2319 // Create a value rib for the function.
2320 self.value_ribs.push(Rib::new(rib_kind));
2322 // Create a label rib for the function.
2323 self.label_ribs.push(Rib::new(rib_kind));
2325 // Add each argument to the rib.
2326 let mut bindings_list = HashMap::new();
2327 for argument in &declaration.inputs {
2328 self.resolve_pattern(&*argument.pat,
2329 ArgumentIrrefutableMode,
2330 &mut bindings_list);
2332 self.visit_ty(&*argument.ty);
2334 debug!("(resolving function) recorded argument");
2336 visit::walk_fn_ret_ty(self, &declaration.output);
2338 // Resolve the function body.
2339 self.visit_block(&*block);
2341 debug!("(resolving function) leaving function");
2344 self.label_ribs.pop();
2345 self.value_ribs.pop();
2349 fn resolve_trait_reference(&mut self,
2353 -> Result<PathResolution, ()> {
2354 if let Some(path_res) = self.resolve_path(id, trait_path, path_depth, TypeNS, true) {
2355 if let DefTrait(_) = path_res.base_def {
2356 debug!("(resolving trait) found trait def: {:?}", path_res);
2361 ResolutionError::IsNotATrait(&*path_names_to_string(trait_path,
2365 // If it's a typedef, give a note
2366 if let DefTy(..) = path_res.base_def {
2367 self.session.span_note(trait_path.span,
2368 "`type` aliases cannot be used for traits");
2375 ResolutionError::UndeclaredTraitName(
2376 &*path_names_to_string(trait_path, path_depth))
2382 fn resolve_generics(&mut self, generics: &Generics) {
2383 for type_parameter in generics.ty_params.iter() {
2384 self.check_if_primitive_type_name(type_parameter.name, type_parameter.span);
2386 for predicate in &generics.where_clause.predicates {
2388 &hir::WherePredicate::BoundPredicate(_) |
2389 &hir::WherePredicate::RegionPredicate(_) => {}
2390 &hir::WherePredicate::EqPredicate(ref eq_pred) => {
2391 let path_res = self.resolve_path(eq_pred.id, &eq_pred.path, 0, TypeNS, true);
2392 if let Some(PathResolution { base_def: DefTyParam(..), .. }) = path_res {
2393 self.record_def(eq_pred.id, path_res.unwrap());
2397 ResolutionError::UndeclaredAssociatedType);
2402 visit::walk_generics(self, generics);
2405 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2406 where F: FnOnce(&mut Resolver) -> T
2408 // Handle nested impls (inside fn bodies)
2409 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2410 let result = f(self);
2411 self.current_self_type = previous_value;
2415 fn with_optional_trait_ref<T, F>(&mut self,
2416 opt_trait_ref: Option<&TraitRef>,
2419 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2421 let mut new_val = None;
2422 let mut new_id = None;
2423 if let Some(trait_ref) = opt_trait_ref {
2424 if let Ok(path_res) = self.resolve_trait_reference(trait_ref.ref_id,
2425 &trait_ref.path, 0) {
2426 assert!(path_res.depth == 0);
2427 self.record_def(trait_ref.ref_id, path_res);
2428 new_val = Some((path_res.base_def.def_id(), trait_ref.clone()));
2429 new_id = Some(path_res.base_def.def_id());
2431 visit::walk_trait_ref(self, trait_ref);
2433 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2434 let result = f(self, new_id);
2435 self.current_trait_ref = original_trait_ref;
2439 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2440 where F: FnOnce(&mut Resolver)
2442 let mut self_type_rib = Rib::new(NormalRibKind);
2444 // plain insert (no renaming, types are not currently hygienic....)
2445 let name = special_names::type_self;
2446 self_type_rib.bindings.insert(name, DlDef(self_def));
2447 self.type_ribs.push(self_type_rib);
2450 self.type_ribs.pop();
2454 fn resolve_implementation(&mut self,
2455 generics: &Generics,
2456 opt_trait_reference: &Option<TraitRef>,
2459 impl_items: &[P<ImplItem>]) {
2460 // If applicable, create a rib for the type parameters.
2461 self.with_type_parameter_rib(HasTypeParameters(generics,
2465 // Resolve the type parameters.
2466 this.visit_generics(generics);
2468 // Resolve the trait reference, if necessary.
2469 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2470 // Resolve the self type.
2471 this.visit_ty(self_type);
2473 this.with_self_rib(DefSelfTy(trait_id, Some((item_id, self_type.id))), |this| {
2474 this.with_current_self_type(self_type, |this| {
2475 for impl_item in impl_items {
2476 match impl_item.node {
2477 ConstImplItem(..) => {
2478 // If this is a trait impl, ensure the const
2480 this.check_trait_item(impl_item.name,
2482 |n, s| ResolutionError::ConstNotMemberOfTrait(n, s));
2483 this.with_constant_rib(|this| {
2484 visit::walk_impl_item(this, impl_item);
2487 MethodImplItem(ref sig, _) => {
2488 // If this is a trait impl, ensure the method
2490 this.check_trait_item(impl_item.name,
2492 |n, s| ResolutionError::MethodNotMemberOfTrait(n, s));
2494 // We also need a new scope for the method-
2495 // specific type parameters.
2496 let type_parameters =
2497 HasTypeParameters(&sig.generics,
2500 this.with_type_parameter_rib(type_parameters, |this| {
2501 visit::walk_impl_item(this, impl_item);
2504 TypeImplItem(ref ty) => {
2505 // If this is a trait impl, ensure the type
2507 this.check_trait_item(impl_item.name,
2509 |n, s| ResolutionError::TypeNotMemberOfTrait(n, s));
2521 fn check_trait_item<F>(&self, name: Name, span: Span, err: F)
2522 where F: FnOnce(Name, &str) -> ResolutionError {
2523 // If there is a TraitRef in scope for an impl, then the method must be in the trait.
2524 if let Some((did, ref trait_ref)) = self.current_trait_ref {
2525 if !self.trait_item_map.contains_key(&(name, did)) {
2526 let path_str = path_names_to_string(&trait_ref.path, 0);
2529 err(name, &*path_str));
2534 fn resolve_local(&mut self, local: &Local) {
2535 // Resolve the type.
2536 walk_list!(self, visit_ty, &local.ty);
2538 // Resolve the initializer.
2539 walk_list!(self, visit_expr, &local.init);
2541 // Resolve the pattern.
2542 self.resolve_pattern(&*local.pat,
2543 LocalIrrefutableMode,
2544 &mut HashMap::new());
2547 // build a map from pattern identifiers to binding-info's.
2548 // this is done hygienically. This could arise for a macro
2549 // that expands into an or-pattern where one 'x' was from the
2550 // user and one 'x' came from the macro.
2551 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2552 let mut result = HashMap::new();
2553 pat_bindings_hygienic(&self.def_map, pat, |binding_mode, _id, sp, path1| {
2554 let name = mtwt::resolve(path1.node);
2555 result.insert(name, BindingInfo {
2557 binding_mode: binding_mode
2563 // check that all of the arms in an or-pattern have exactly the
2564 // same set of bindings, with the same binding modes for each.
2565 fn check_consistent_bindings(&mut self, arm: &Arm) {
2566 if arm.pats.is_empty() {
2569 let map_0 = self.binding_mode_map(&*arm.pats[0]);
2570 for (i, p) in arm.pats.iter().enumerate() {
2571 let map_i = self.binding_mode_map(&**p);
2573 for (&key, &binding_0) in &map_0 {
2574 match map_i.get(&key) {
2578 ResolutionError::VariableNotBoundInPattern(key,
2581 Some(binding_i) => {
2582 if binding_0.binding_mode != binding_i.binding_mode {
2585 ResolutionError::VariableBoundWithDifferentMode(key,
2593 for (&key, &binding) in &map_i {
2594 if !map_0.contains_key(&key) {
2597 ResolutionError::VariableNotBoundInParentPattern(key,
2604 fn resolve_arm(&mut self, arm: &Arm) {
2605 self.value_ribs.push(Rib::new(NormalRibKind));
2607 let mut bindings_list = HashMap::new();
2608 for pattern in &arm.pats {
2609 self.resolve_pattern(&**pattern, RefutableMode, &mut bindings_list);
2612 // This has to happen *after* we determine which
2613 // pat_idents are variants
2614 self.check_consistent_bindings(arm);
2616 walk_list!(self, visit_expr, &arm.guard);
2617 self.visit_expr(&*arm.body);
2620 self.value_ribs.pop();
2624 fn resolve_block(&mut self, block: &Block) {
2625 debug!("(resolving block) entering block");
2626 self.value_ribs.push(Rib::new(NormalRibKind));
2628 // Move down in the graph, if there's an anonymous module rooted here.
2629 let orig_module = self.current_module.clone();
2630 match orig_module.anonymous_children.borrow().get(&block.id) {
2631 None => { /* Nothing to do. */ }
2632 Some(anonymous_module) => {
2633 debug!("(resolving block) found anonymous module, moving \
2635 self.current_module = anonymous_module.clone();
2639 // Check for imports appearing after non-item statements.
2640 let mut found_non_item = false;
2641 for statement in &block.stmts {
2642 if let hir::StmtDecl(ref declaration, _) = statement.node {
2643 if let hir::DeclItem(ref i) = declaration.node {
2645 ItemExternCrate(_) | ItemUse(_) if found_non_item => {
2646 span_err!(self.session, i.span, E0154,
2647 "imports are not allowed after non-item statements");
2652 found_non_item = true
2655 found_non_item = true;
2659 // Descend into the block.
2660 visit::walk_block(self, block);
2664 self.current_module = orig_module;
2665 self.value_ribs.pop();
2667 debug!("(resolving block) leaving block");
2670 fn resolve_type(&mut self, ty: &Ty) {
2672 TyPath(ref maybe_qself, ref path) => {
2674 match self.resolve_possibly_assoc_item(ty.id,
2675 maybe_qself.as_ref(),
2679 // `<T>::a::b::c` is resolved by typeck alone.
2680 TypecheckRequired => {
2681 // Resolve embedded types.
2682 visit::walk_ty(self, ty);
2685 ResolveAttempt(resolution) => resolution,
2688 // This is a path in the type namespace. Walk through scopes
2692 // Write the result into the def map.
2693 debug!("(resolving type) writing resolution for `{}` \
2695 path_names_to_string(path, 0),
2697 self.record_def(ty.id, def);
2700 // Keep reporting some errors even if they're ignored above.
2701 self.resolve_path(ty.id, path, 0, TypeNS, true);
2703 let kind = if maybe_qself.is_some() {
2709 let self_type_name = special_idents::type_self.name;
2710 let is_invalid_self_type_name =
2711 path.segments.len() > 0 &&
2712 maybe_qself.is_none() &&
2713 path.segments[0].identifier.name == self_type_name;
2714 if is_invalid_self_type_name {
2717 ResolutionError::SelfUsedOutsideImplOrTrait);
2721 ResolutionError::UseOfUndeclared(
2723 &*path_names_to_string(path,
2732 // Resolve embedded types.
2733 visit::walk_ty(self, ty);
2736 fn resolve_pattern(&mut self,
2738 mode: PatternBindingMode,
2739 // Maps idents to the node ID for the (outermost)
2740 // pattern that binds them
2741 bindings_list: &mut HashMap<Name, NodeId>) {
2742 let pat_id = pattern.id;
2743 walk_pat(pattern, |pattern| {
2744 match pattern.node {
2745 PatIdent(binding_mode, ref path1, ref at_rhs) => {
2746 // The meaning of PatIdent with no type parameters
2747 // depends on whether an enum variant or unit-like struct
2748 // with that name is in scope. The probing lookup has to
2749 // be careful not to emit spurious errors. Only matching
2750 // patterns (match) can match nullary variants or
2751 // unit-like structs. For binding patterns (let
2752 // and the LHS of @-patterns), matching such a value is
2753 // simply disallowed (since it's rarely what you want).
2754 let const_ok = mode == RefutableMode && at_rhs.is_none();
2756 let ident = path1.node;
2757 let renamed = mtwt::resolve(ident);
2759 match self.resolve_bare_identifier_pattern(ident.name, pattern.span) {
2760 FoundStructOrEnumVariant(def, lp) if const_ok => {
2761 debug!("(resolving pattern) resolving `{}` to \
2762 struct or enum variant",
2765 self.enforce_default_binding_mode(
2769 self.record_def(pattern.id, PathResolution {
2775 FoundStructOrEnumVariant(..) => {
2779 ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(
2783 FoundConst(def, lp) if const_ok => {
2784 debug!("(resolving pattern) resolving `{}` to \
2788 self.enforce_default_binding_mode(
2792 self.record_def(pattern.id, PathResolution {
2802 ResolutionError::OnlyIrrefutablePatternsAllowedHere
2805 BareIdentifierPatternUnresolved => {
2806 debug!("(resolving pattern) binding `{}`",
2809 let def_id = self.ast_map.local_def_id(pattern.id);
2810 let def = DefLocal(def_id, pattern.id);
2812 // Record the definition so that later passes
2813 // will be able to distinguish variants from
2814 // locals in patterns.
2816 self.record_def(pattern.id, PathResolution {
2818 last_private: LastMod(AllPublic),
2822 // Add the binding to the local ribs, if it
2823 // doesn't already exist in the bindings list. (We
2824 // must not add it if it's in the bindings list
2825 // because that breaks the assumptions later
2826 // passes make about or-patterns.)
2827 if !bindings_list.contains_key(&renamed) {
2828 let this = &mut *self;
2829 let last_rib = this.value_ribs.last_mut().unwrap();
2830 last_rib.bindings.insert(renamed, DlDef(def));
2831 bindings_list.insert(renamed, pat_id);
2832 } else if mode == ArgumentIrrefutableMode &&
2833 bindings_list.contains_key(&renamed) {
2834 // Forbid duplicate bindings in the same
2839 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2840 &ident.name.as_str())
2842 } else if bindings_list.get(&renamed) ==
2844 // Then this is a duplicate variable in the
2845 // same disjunction, which is an error.
2849 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2850 &ident.name.as_str())
2853 // Else, not bound in the same pattern: do
2859 PatEnum(ref path, _) => {
2860 // This must be an enum variant, struct or const.
2862 match self.resolve_possibly_assoc_item(pat_id, None,
2865 // The below shouldn't happen because all
2866 // qualified paths should be in PatQPath.
2867 TypecheckRequired =>
2868 self.session.span_bug(
2870 "resolve_possibly_assoc_item claimed
2871 that a path in PatEnum requires typecheck
2872 to resolve, but qualified paths should be
2874 ResolveAttempt(resolution) => resolution,
2876 if let Some(path_res) = resolution {
2877 match path_res.base_def {
2878 DefVariant(..) | DefStruct(..) | DefConst(..) => {
2879 self.record_def(pattern.id, path_res);
2882 resolve_error(&self,
2884 ResolutionError::StaticVariableReference);
2887 // If anything ends up here entirely resolved,
2888 // it's an error. If anything ends up here
2889 // partially resolved, that's OK, because it may
2890 // be a `T::CONST` that typeck will resolve.
2891 if path_res.depth == 0 {
2895 ResolutionError::NotAnEnumVariantStructOrConst(
2904 let const_name = path.segments.last().unwrap()
2906 let traits = self.get_traits_containing_item(const_name);
2907 self.trait_map.insert(pattern.id, traits);
2908 self.record_def(pattern.id, path_res);
2916 ResolutionError::UnresolvedEnumVariantStructOrConst(
2917 &path.segments.last().unwrap().identifier.name.as_str())
2920 visit::walk_path(self, path);
2923 PatQPath(ref qself, ref path) => {
2924 // Associated constants only.
2926 match self.resolve_possibly_assoc_item(pat_id, Some(qself),
2929 TypecheckRequired => {
2930 // All `<T>::CONST` should end up here, and will
2931 // require use of the trait map to resolve
2932 // during typechecking.
2933 let const_name = path.segments.last().unwrap()
2935 let traits = self.get_traits_containing_item(const_name);
2936 self.trait_map.insert(pattern.id, traits);
2937 visit::walk_pat(self, pattern);
2940 ResolveAttempt(resolution) => resolution,
2942 if let Some(path_res) = resolution {
2943 match path_res.base_def {
2944 // All `<T as Trait>::CONST` should end up here, and
2945 // have the trait already selected.
2946 DefAssociatedConst(..) => {
2947 self.record_def(pattern.id, path_res);
2953 ResolutionError::NotAnAssociatedConst(
2954 &path.segments.last().unwrap().identifier.name.as_str()
2963 ResolutionError::UnresolvedAssociatedConst(
2964 &path.segments.last().unwrap().identifier.name.as_str()
2968 visit::walk_pat(self, pattern);
2971 PatStruct(ref path, _, _) => {
2972 match self.resolve_path(pat_id, path, 0, TypeNS, false) {
2973 Some(definition) => {
2974 self.record_def(pattern.id, definition);
2977 debug!("(resolving pattern) didn't find struct \
2978 def: {:?}", result);
2982 ResolutionError::DoesNotNameAStruct(
2983 &*path_names_to_string(path, 0))
2987 visit::walk_path(self, path);
2990 PatLit(_) | PatRange(..) => {
2991 visit::walk_pat(self, pattern);
3002 fn resolve_bare_identifier_pattern(&mut self, name: Name, span: Span)
3003 -> BareIdentifierPatternResolution {
3004 let module = self.current_module.clone();
3005 match self.resolve_item_in_lexical_scope(module,
3008 Success((target, _)) => {
3009 debug!("(resolve bare identifier pattern) succeeded in \
3010 finding {} at {:?}",
3012 target.bindings.value_def.borrow());
3013 match *target.bindings.value_def.borrow() {
3015 panic!("resolved name in the value namespace to a \
3016 set of name bindings with no def?!");
3019 // For the two success cases, this lookup can be
3020 // considered as not having a private component because
3021 // the lookup happened only within the current module.
3023 def @ DefVariant(..) | def @ DefStruct(..) => {
3024 return FoundStructOrEnumVariant(def, LastMod(AllPublic));
3026 def @ DefConst(..) | def @ DefAssociatedConst(..) => {
3027 return FoundConst(def, LastMod(AllPublic));
3032 ResolutionError::StaticVariableReference);
3033 return BareIdentifierPatternUnresolved;
3036 return BareIdentifierPatternUnresolved;
3044 panic!("unexpected indeterminate result");
3048 Some((span, msg)) => {
3049 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3054 debug!("(resolve bare identifier pattern) failed to find {}",
3056 return BareIdentifierPatternUnresolved;
3061 /// Handles paths that may refer to associated items
3062 fn resolve_possibly_assoc_item(&mut self,
3064 maybe_qself: Option<&hir::QSelf>,
3066 namespace: Namespace,
3068 -> AssocItemResolveResult
3070 let max_assoc_types;
3074 if qself.position == 0 {
3075 return TypecheckRequired;
3077 max_assoc_types = path.segments.len() - qself.position;
3078 // Make sure the trait is valid.
3079 let _ = self.resolve_trait_reference(id, path, max_assoc_types);
3082 max_assoc_types = path.segments.len();
3086 let mut resolution = self.with_no_errors(|this| {
3087 this.resolve_path(id, path, 0, namespace, check_ribs)
3089 for depth in 1..max_assoc_types {
3090 if resolution.is_some() {
3093 self.with_no_errors(|this| {
3094 resolution = this.resolve_path(id, path, depth,
3098 if let Some(DefMod(_)) = resolution.map(|r| r.base_def) {
3099 // A module is not a valid type or value.
3102 ResolveAttempt(resolution)
3105 /// If `check_ribs` is true, checks the local definitions first; i.e.
3106 /// doesn't skip straight to the containing module.
3107 /// Skips `path_depth` trailing segments, which is also reflected in the
3108 /// returned value. See `middle::def::PathResolution` for more info.
3109 pub fn resolve_path(&mut self,
3113 namespace: Namespace,
3114 check_ribs: bool) -> Option<PathResolution> {
3115 let span = path.span;
3116 let segments = &path.segments[..path.segments.len()-path_depth];
3118 let mk_res = |(def, lp)| PathResolution::new(def, lp, path_depth);
3121 let def = self.resolve_crate_relative_path(span, segments, namespace);
3122 return def.map(mk_res);
3125 // Try to find a path to an item in a module.
3126 let unqualified_def =
3127 self.resolve_identifier(segments.last().unwrap().identifier,
3132 if segments.len() <= 1 {
3133 return unqualified_def.map(mk_res);
3136 let def = self.resolve_module_relative_path(span, segments, namespace);
3137 match (def, unqualified_def) {
3138 (Some((ref d, _)), Some((ref ud, _))) if *d == *ud => {
3140 .add_lint(lint::builtin::UNUSED_QUALIFICATIONS,
3142 "unnecessary qualification".to_string());
3150 // Resolve a single identifier.
3151 fn resolve_identifier(&mut self,
3153 namespace: Namespace,
3156 -> Option<(Def, LastPrivate)> {
3157 // First, check to see whether the name is a primitive type.
3158 if namespace == TypeNS {
3159 if let Some(&prim_ty) = self.primitive_type_table
3161 .get(&identifier.name) {
3162 return Some((DefPrimTy(prim_ty), LastMod(AllPublic)));
3167 if let Some(def) = self.resolve_identifier_in_local_ribs(identifier,
3170 return Some((def, LastMod(AllPublic)));
3174 self.resolve_item_by_name_in_lexical_scope(identifier.name, namespace)
3177 // FIXME #4952: Merge me with resolve_name_in_module?
3178 fn resolve_definition_of_name_in_module(&mut self,
3179 containing_module: Rc<Module>,
3181 namespace: Namespace)
3183 // First, search children.
3184 build_reduced_graph::populate_module_if_necessary(self, &containing_module);
3186 match containing_module.children.borrow().get(&name) {
3187 Some(child_name_bindings) => {
3188 match child_name_bindings.def_for_namespace(namespace) {
3190 // Found it. Stop the search here.
3191 let p = child_name_bindings.defined_in_public_namespace(namespace);
3192 let lp = if p {LastMod(AllPublic)} else {
3193 LastMod(DependsOn(def.def_id()))
3195 return ChildNameDefinition(def, lp);
3203 // Next, search import resolutions.
3204 match containing_module.import_resolutions.borrow().get(&name) {
3205 Some(import_resolution) if import_resolution.is_public => {
3206 if let Some(target) = (*import_resolution).target_for_namespace(namespace) {
3207 match target.bindings.def_for_namespace(namespace) {
3210 let id = import_resolution.id(namespace);
3211 // track imports and extern crates as well
3212 self.used_imports.insert((id, namespace));
3213 self.record_import_use(id, name);
3214 match target.target_module.def_id.get() {
3215 Some(DefId{krate: kid, ..}) => {
3216 self.used_crates.insert(kid);
3220 return ImportNameDefinition(def, LastMod(AllPublic));
3223 // This can happen with external impls, due to
3224 // the imperfect way we read the metadata.
3229 Some(..) | None => {} // Continue.
3232 // Finally, search through external children.
3233 if namespace == TypeNS {
3234 if let Some(module) = containing_module.external_module_children.borrow()
3235 .get(&name).cloned() {
3236 if let Some(def_id) = module.def_id.get() {
3237 // track used crates
3238 self.used_crates.insert(def_id.krate);
3239 let lp = if module.is_public {LastMod(AllPublic)} else {
3240 LastMod(DependsOn(def_id))
3242 return ChildNameDefinition(DefMod(def_id), lp);
3247 return NoNameDefinition;
3250 // resolve a "module-relative" path, e.g. a::b::c
3251 fn resolve_module_relative_path(&mut self,
3253 segments: &[hir::PathSegment],
3254 namespace: Namespace)
3255 -> Option<(Def, LastPrivate)> {
3256 let module_path = segments.split_last().unwrap().1.iter()
3257 .map(|ps| ps.identifier.name)
3258 .collect::<Vec<_>>();
3260 let containing_module;
3262 let current_module = self.current_module.clone();
3263 match self.resolve_module_path(current_module,
3269 let (span, msg) = match err {
3270 Some((span, msg)) => (span, msg),
3272 let msg = format!("Use of undeclared type or module `{}`",
3273 names_to_string(&module_path));
3278 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3281 Indeterminate => panic!("indeterminate unexpected"),
3282 Success((resulting_module, resulting_last_private)) => {
3283 containing_module = resulting_module;
3284 last_private = resulting_last_private;
3288 let name = segments.last().unwrap().identifier.name;
3289 let def = match self.resolve_definition_of_name_in_module(containing_module.clone(),
3292 NoNameDefinition => {
3293 // We failed to resolve the name. Report an error.
3296 ChildNameDefinition(def, lp) | ImportNameDefinition(def, lp) => {
3297 (def, last_private.or(lp))
3300 if let Some(DefId{krate: kid, ..}) = containing_module.def_id.get() {
3301 self.used_crates.insert(kid);
3306 /// Invariant: This must be called only during main resolution, not during
3307 /// import resolution.
3308 fn resolve_crate_relative_path(&mut self,
3310 segments: &[hir::PathSegment],
3311 namespace: Namespace)
3312 -> Option<(Def, LastPrivate)> {
3313 let module_path = segments.split_last().unwrap().1.iter()
3314 .map(|ps| ps.identifier.name)
3315 .collect::<Vec<_>>();
3317 let root_module = self.graph_root.get_module();
3319 let containing_module;
3321 match self.resolve_module_path_from_root(root_module,
3326 LastMod(AllPublic)) {
3328 let (span, msg) = match err {
3329 Some((span, msg)) => (span, msg),
3331 let msg = format!("Use of undeclared module `::{}`",
3332 names_to_string(&module_path[..]));
3337 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3342 panic!("indeterminate unexpected");
3345 Success((resulting_module, resulting_last_private)) => {
3346 containing_module = resulting_module;
3347 last_private = resulting_last_private;
3351 let name = segments.last().unwrap().identifier.name;
3352 match self.resolve_definition_of_name_in_module(containing_module,
3355 NoNameDefinition => {
3356 // We failed to resolve the name. Report an error.
3359 ChildNameDefinition(def, lp) | ImportNameDefinition(def, lp) => {
3360 return Some((def, last_private.or(lp)));
3365 fn resolve_identifier_in_local_ribs(&mut self,
3367 namespace: Namespace,
3370 // Check the local set of ribs.
3371 let search_result = match namespace {
3373 let renamed = mtwt::resolve(ident);
3374 self.search_ribs(&self.value_ribs, renamed, span)
3377 let name = ident.name;
3378 self.search_ribs(&self.type_ribs, name, span)
3382 match search_result {
3383 Some(DlDef(def)) => {
3384 debug!("(resolving path in local ribs) resolved `{}` to local: {:?}",
3389 Some(DlField) | Some(DlImpl(_)) | None => {
3395 fn resolve_item_by_name_in_lexical_scope(&mut self,
3397 namespace: Namespace)
3398 -> Option<(Def, LastPrivate)> {
3400 let module = self.current_module.clone();
3401 match self.resolve_item_in_lexical_scope(module,
3404 Success((target, _)) => {
3405 match (*target.bindings).def_for_namespace(namespace) {
3407 // This can happen if we were looking for a type and
3408 // found a module instead. Modules don't have defs.
3409 debug!("(resolving item path by identifier in lexical \
3410 scope) failed to resolve {} after success...",
3415 debug!("(resolving item path in lexical scope) \
3416 resolved `{}` to item",
3418 // This lookup is "all public" because it only searched
3419 // for one identifier in the current module (couldn't
3420 // have passed through reexports or anything like that.
3421 return Some((def, LastMod(AllPublic)));
3426 panic!("unexpected indeterminate result");
3429 debug!("(resolving item path by identifier in lexical scope) \
3430 failed to resolve {}", name);
3432 if let Some((span, msg)) = err {
3433 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg))
3441 fn with_no_errors<T, F>(&mut self, f: F) -> T where
3442 F: FnOnce(&mut Resolver) -> T,
3444 self.emit_errors = false;
3446 self.emit_errors = true;
3450 fn find_fallback_in_self_type(&mut self, name: Name) -> FallbackSuggestion {
3451 fn extract_path_and_node_id(t: &Ty, allow: FallbackChecks)
3452 -> Option<(Path, NodeId, FallbackChecks)> {
3454 TyPath(None, ref path) => Some((path.clone(), t.id, allow)),
3455 TyPtr(ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, OnlyTraitAndStatics),
3456 TyRptr(_, ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, allow),
3457 // This doesn't handle the remaining `Ty` variants as they are not
3458 // that commonly the self_type, it might be interesting to provide
3459 // support for those in future.
3464 fn get_module(this: &mut Resolver, span: Span, name_path: &[ast::Name])
3465 -> Option<Rc<Module>> {
3466 let root = this.current_module.clone();
3467 let last_name = name_path.last().unwrap();
3469 if name_path.len() == 1 {
3470 match this.primitive_type_table.primitive_types.get(last_name) {
3473 match this.current_module.children.borrow().get(last_name) {
3474 Some(child) => child.get_module_if_available(),
3480 match this.resolve_module_path(root,
3485 Success((module, _)) => Some(module),
3491 fn is_static_method(this: &Resolver, did: DefId) -> bool {
3492 if let Some(node_id) = this.ast_map.as_local_node_id(did) {
3493 let sig = match this.ast_map.get(node_id) {
3494 hir_map::NodeTraitItem(trait_item) => match trait_item.node {
3495 hir::MethodTraitItem(ref sig, _) => sig,
3498 hir_map::NodeImplItem(impl_item) => match impl_item.node {
3499 hir::MethodImplItem(ref sig, _) => sig,
3504 sig.explicit_self.node == hir::SelfStatic
3506 csearch::is_static_method(&this.session.cstore, did)
3510 let (path, node_id, allowed) = match self.current_self_type {
3511 Some(ref ty) => match extract_path_and_node_id(ty, Everything) {
3513 None => return NoSuggestion,
3515 None => return NoSuggestion,
3518 if allowed == Everything {
3519 // Look for a field with the same name in the current self_type.
3520 match self.def_map.borrow().get(&node_id).map(|d| d.full_def()) {
3521 Some(DefTy(did, _)) |
3522 Some(DefStruct(did)) |
3523 Some(DefVariant(_, did, _)) => match self.structs.get(&did) {
3526 if fields.iter().any(|&field_name| name == field_name) {
3531 _ => {} // Self type didn't resolve properly
3535 let name_path = path.segments.iter().map(|seg| seg.identifier.name).collect::<Vec<_>>();
3537 // Look for a method in the current self type's impl module.
3538 if let Some(module) = get_module(self, path.span, &name_path) {
3539 if let Some(binding) = module.children.borrow().get(&name) {
3540 if let Some(DefMethod(did)) = binding.def_for_namespace(ValueNS) {
3541 if is_static_method(self, did) {
3542 return StaticMethod(path_names_to_string(&path, 0))
3544 if self.current_trait_ref.is_some() {
3546 } else if allowed == Everything {
3553 // Look for a method in the current trait.
3554 if let Some((trait_did, ref trait_ref)) = self.current_trait_ref {
3555 if let Some(&did) = self.trait_item_map.get(&(name, trait_did)) {
3556 if is_static_method(self, did) {
3557 return TraitMethod(path_names_to_string(&trait_ref.path, 0));
3567 fn find_best_match_for_name(&mut self, name: &str) -> Option<String> {
3568 let mut maybes: Vec<token::InternedString> = Vec::new();
3569 let mut values: Vec<usize> = Vec::new();
3571 for rib in self.value_ribs.iter().rev() {
3572 for (&k, _) in &rib.bindings {
3573 maybes.push(k.as_str());
3574 values.push(usize::MAX);
3578 let mut smallest = 0;
3579 for (i, other) in maybes.iter().enumerate() {
3580 values[i] = lev_distance(name, &other);
3582 if values[i] <= values[smallest] {
3587 // As a loose rule to avoid obviously incorrect suggestions, clamp the
3588 // maximum edit distance we will accept for a suggestion to one third of
3589 // the typo'd name's length.
3590 let max_distance = std::cmp::max(name.len(), 3) / 3;
3592 if !values.is_empty() &&
3593 values[smallest] <= max_distance &&
3594 name != &maybes[smallest][..] {
3596 Some(maybes[smallest].to_string())
3603 fn resolve_expr(&mut self, expr: &Expr) {
3604 // First, record candidate traits for this expression if it could
3605 // result in the invocation of a method call.
3607 self.record_candidate_traits_for_expr_if_necessary(expr);
3609 // Next, resolve the node.
3611 ExprPath(ref maybe_qself, ref path) => {
3613 match self.resolve_possibly_assoc_item(expr.id,
3614 maybe_qself.as_ref(),
3618 // `<T>::a::b::c` is resolved by typeck alone.
3619 TypecheckRequired => {
3620 let method_name = path.segments.last().unwrap().identifier.name;
3621 let traits = self.get_traits_containing_item(method_name);
3622 self.trait_map.insert(expr.id, traits);
3623 visit::walk_expr(self, expr);
3626 ResolveAttempt(resolution) => resolution,
3629 // This is a local path in the value namespace. Walk through
3630 // scopes looking for it.
3631 if let Some(path_res) = resolution {
3632 // Check if struct variant
3633 if let DefVariant(_, _, true) = path_res.base_def {
3634 let path_name = path_names_to_string(path, 0);
3638 ResolutionError::StructVariantUsedAsFunction(&*path_name));
3640 let msg = format!("did you mean to write: \
3641 `{} {{ /* fields */ }}`?",
3643 if self.emit_errors {
3644 self.session.fileline_help(expr.span, &msg);
3646 self.session.span_help(expr.span, &msg);
3649 // Write the result into the def map.
3650 debug!("(resolving expr) resolved `{}`",
3651 path_names_to_string(path, 0));
3653 // Partial resolutions will need the set of traits in scope,
3654 // so they can be completed during typeck.
3655 if path_res.depth != 0 {
3656 let method_name = path.segments.last().unwrap().identifier.name;
3657 let traits = self.get_traits_containing_item(method_name);
3658 self.trait_map.insert(expr.id, traits);
3661 self.record_def(expr.id, path_res);
3664 // Be helpful if the name refers to a struct
3665 // (The pattern matching def_tys where the id is in self.structs
3666 // matches on regular structs while excluding tuple- and enum-like
3667 // structs, which wouldn't result in this error.)
3668 let path_name = path_names_to_string(path, 0);
3669 let type_res = self.with_no_errors(|this| {
3670 this.resolve_path(expr.id, path, 0, TypeNS, false)
3672 match type_res.map(|r| r.base_def) {
3673 Some(DefTy(struct_id, _))
3674 if self.structs.contains_key(&struct_id) => {
3678 ResolutionError::StructVariantUsedAsFunction(
3682 let msg = format!("did you mean to write: \
3683 `{} {{ /* fields */ }}`?",
3685 if self.emit_errors {
3686 self.session.fileline_help(expr.span, &msg);
3688 self.session.span_help(expr.span, &msg);
3692 // Keep reporting some errors even if they're ignored above.
3693 self.resolve_path(expr.id, path, 0, ValueNS, true);
3695 let mut method_scope = false;
3696 self.value_ribs.iter().rev().all(|rib| {
3697 method_scope = match rib.kind {
3698 MethodRibKind => true,
3699 ItemRibKind | ConstantItemRibKind => false,
3700 _ => return true, // Keep advancing
3702 false // Stop advancing
3705 if method_scope && special_names::self_.as_str() == &path_name[..] {
3709 ResolutionError::SelfNotAvailableInStaticMethod
3712 let last_name = path.segments.last().unwrap().identifier.name;
3713 let mut msg = match self.find_fallback_in_self_type(last_name) {
3715 // limit search to 5 to reduce the number
3716 // of stupid suggestions
3717 self.find_best_match_for_name(&path_name)
3718 .map_or("".to_string(),
3719 |x| format!("`{}`", x))
3721 Field => format!("`self.{}`", path_name),
3724 format!("to call `self.{}`", path_name),
3725 TraitMethod(path_str) |
3726 StaticMethod(path_str) =>
3727 format!("to call `{}::{}`", path_str, path_name)
3730 if !msg.is_empty() {
3731 msg = format!(". Did you mean {}?", msg)
3736 ResolutionError::UnresolvedName(&*path_name,
3743 visit::walk_expr(self, expr);
3746 ExprStruct(ref path, _, _) => {
3747 // Resolve the path to the structure it goes to. We don't
3748 // check to ensure that the path is actually a structure; that
3749 // is checked later during typeck.
3750 match self.resolve_path(expr.id, path, 0, TypeNS, false) {
3751 Some(definition) => self.record_def(expr.id, definition),
3753 debug!("(resolving expression) didn't find struct def",);
3757 ResolutionError::DoesNotNameAStruct(
3758 &*path_names_to_string(path, 0))
3763 visit::walk_expr(self, expr);
3766 ExprLoop(_, Some(label)) | ExprWhile(_, _, Some(label)) => {
3767 self.with_label_rib(|this| {
3768 let def_like = DlDef(DefLabel(expr.id));
3771 let rib = this.label_ribs.last_mut().unwrap();
3772 let renamed = mtwt::resolve(label);
3773 rib.bindings.insert(renamed, def_like);
3776 visit::walk_expr(this, expr);
3780 ExprBreak(Some(label)) | ExprAgain(Some(label)) => {
3781 let renamed = mtwt::resolve(label.node);
3782 match self.search_label(renamed) {
3786 ResolutionError::UndeclaredLabel(&label.node.name.as_str()))
3788 Some(DlDef(def @ DefLabel(_))) => {
3789 // Since this def is a label, it is never read.
3790 self.record_def(expr.id, PathResolution {
3792 last_private: LastMod(AllPublic),
3797 self.session.span_bug(expr.span,
3798 "label wasn't mapped to a \
3805 visit::walk_expr(self, expr);
3810 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3812 ExprField(_, name) => {
3813 // FIXME(#6890): Even though you can't treat a method like a
3814 // field, we need to add any trait methods we find that match
3815 // the field name so that we can do some nice error reporting
3816 // later on in typeck.
3817 let traits = self.get_traits_containing_item(name.node);
3818 self.trait_map.insert(expr.id, traits);
3820 ExprMethodCall(name, _, _) => {
3821 debug!("(recording candidate traits for expr) recording \
3824 let traits = self.get_traits_containing_item(name.node);
3825 self.trait_map.insert(expr.id, traits);
3833 fn get_traits_containing_item(&mut self, name: Name) -> Vec<DefId> {
3834 debug!("(getting traits containing item) looking for '{}'",
3837 fn add_trait_info(found_traits: &mut Vec<DefId>,
3838 trait_def_id: DefId,
3840 debug!("(adding trait info) found trait {:?} for method '{}'",
3843 found_traits.push(trait_def_id);
3846 let mut found_traits = Vec::new();
3847 let mut search_module = self.current_module.clone();
3849 // Look for the current trait.
3850 match self.current_trait_ref {
3851 Some((trait_def_id, _)) => {
3852 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3853 add_trait_info(&mut found_traits, trait_def_id, name);
3856 None => {} // Nothing to do.
3859 // Look for trait children.
3860 build_reduced_graph::populate_module_if_necessary(self, &search_module);
3863 for (_, child_names) in search_module.children.borrow().iter() {
3864 let def = match child_names.def_for_namespace(TypeNS) {
3868 let trait_def_id = match def {
3869 DefTrait(trait_def_id) => trait_def_id,
3872 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3873 add_trait_info(&mut found_traits, trait_def_id, name);
3878 // Look for imports.
3879 for (_, import) in search_module.import_resolutions.borrow().iter() {
3880 let target = match import.target_for_namespace(TypeNS) {
3882 Some(target) => target,
3884 let did = match target.bindings.def_for_namespace(TypeNS) {
3885 Some(DefTrait(trait_def_id)) => trait_def_id,
3886 Some(..) | None => continue,
3888 if self.trait_item_map.contains_key(&(name, did)) {
3889 add_trait_info(&mut found_traits, did, name);
3890 let id = import.type_id;
3891 self.used_imports.insert((id, TypeNS));
3892 let trait_name = self.get_trait_name(did);
3893 self.record_import_use(id, trait_name);
3894 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id.get() {
3895 self.used_crates.insert(kid);
3900 match search_module.parent_link.clone() {
3901 NoParentLink | ModuleParentLink(..) => break,
3902 BlockParentLink(parent_module, _) => {
3903 search_module = parent_module.upgrade().unwrap();
3911 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
3912 debug!("(recording def) recording {:?} for {}", resolution, node_id);
3913 assert!(match resolution.last_private {LastImport{..} => false, _ => true},
3914 "Import should only be used for `use` directives");
3916 if let Some(prev_res) = self.def_map.borrow_mut().insert(node_id, resolution) {
3917 let span = self.ast_map.opt_span(node_id).unwrap_or(codemap::DUMMY_SP);
3918 self.session.span_bug(span, &format!("path resolved multiple times \
3919 ({:?} before, {:?} now)",
3920 prev_res, resolution));
3924 fn enforce_default_binding_mode(&mut self,
3926 pat_binding_mode: BindingMode,
3928 match pat_binding_mode {
3929 BindByValue(_) => {}
3933 ResolutionError::CannotUseRefBindingModeWith(descr));
3941 // Diagnostics are not particularly efficient, because they're rarely
3945 #[allow(dead_code)] // useful for debugging
3946 fn dump_module(&mut self, module_: Rc<Module>) {
3947 debug!("Dump of module `{}`:", module_to_string(&*module_));
3949 debug!("Children:");
3950 build_reduced_graph::populate_module_if_necessary(self, &module_);
3951 for (&name, _) in module_.children.borrow().iter() {
3952 debug!("* {}", name);
3955 debug!("Import resolutions:");
3956 let import_resolutions = module_.import_resolutions.borrow();
3957 for (&name, import_resolution) in import_resolutions.iter() {
3959 match import_resolution.target_for_namespace(ValueNS) {
3960 None => { value_repr = "".to_string(); }
3962 value_repr = " value:?".to_string();
3968 match import_resolution.target_for_namespace(TypeNS) {
3969 None => { type_repr = "".to_string(); }
3971 type_repr = " type:?".to_string();
3976 debug!("* {}:{}{}", name, value_repr, type_repr);
3982 fn names_to_string(names: &[Name]) -> String {
3983 let mut first = true;
3984 let mut result = String::new();
3989 result.push_str("::")
3991 result.push_str(&name.as_str());
3996 fn path_names_to_string(path: &Path, depth: usize) -> String {
3997 let names: Vec<ast::Name> = path.segments[..path.segments.len()-depth]
3999 .map(|seg| seg.identifier.name)
4001 names_to_string(&names[..])
4004 /// A somewhat inefficient routine to obtain the name of a module.
4005 fn module_to_string(module: &Module) -> String {
4006 let mut names = Vec::new();
4008 fn collect_mod(names: &mut Vec<ast::Name>, module: &Module) {
4009 match module.parent_link {
4011 ModuleParentLink(ref module, name) => {
4013 collect_mod(names, &*module.upgrade().unwrap());
4015 BlockParentLink(ref module, _) => {
4016 // danger, shouldn't be ident?
4017 names.push(special_idents::opaque.name);
4018 collect_mod(names, &*module.upgrade().unwrap());
4022 collect_mod(&mut names, module);
4024 if names.is_empty() {
4025 return "???".to_string();
4027 names_to_string(&names.into_iter().rev().collect::<Vec<ast::Name>>())
4031 pub struct CrateMap {
4032 pub def_map: DefMap,
4033 pub freevars: RefCell<FreevarMap>,
4034 pub export_map: ExportMap,
4035 pub trait_map: TraitMap,
4036 pub external_exports: ExternalExports,
4037 pub glob_map: Option<GlobMap>
4040 #[derive(PartialEq,Copy, Clone)]
4041 pub enum MakeGlobMap {
4046 /// Entry point to crate resolution.
4047 pub fn resolve_crate<'a, 'tcx>(session: &'a Session,
4048 ast_map: &'a hir_map::Map<'tcx>,
4049 make_glob_map: MakeGlobMap)
4051 let krate = ast_map.krate();
4052 let mut resolver = create_resolver(session, ast_map, krate, make_glob_map, None);
4054 resolver.resolve_crate(krate);
4055 session.abort_if_errors();
4057 check_unused::check_crate(&mut resolver, krate);
4060 def_map: resolver.def_map,
4061 freevars: resolver.freevars,
4062 export_map: resolver.export_map,
4063 trait_map: resolver.trait_map,
4064 external_exports: resolver.external_exports,
4065 glob_map: if resolver.make_glob_map {
4066 Some(resolver.glob_map)
4073 /// Builds a name resolution walker to be used within this module,
4074 /// or used externally, with an optional callback function.
4076 /// The callback takes a &mut bool which allows callbacks to end a
4077 /// walk when set to true, passing through the rest of the walk, while
4078 /// preserving the ribs + current module. This allows resolve_path
4079 /// calls to be made with the correct scope info. The node in the
4080 /// callback corresponds to the current node in the walk.
4081 pub fn create_resolver<'a, 'tcx>(session: &'a Session,
4082 ast_map: &'a hir_map::Map<'tcx>,
4084 make_glob_map: MakeGlobMap,
4085 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>)
4086 -> Resolver<'a, 'tcx> {
4087 let mut resolver = Resolver::new(session, ast_map, krate.span, make_glob_map);
4089 resolver.callback = callback;
4091 build_reduced_graph::build_reduced_graph(&mut resolver, krate);
4092 session.abort_if_errors();
4094 resolve_imports::resolve_imports(&mut resolver);
4095 session.abort_if_errors();
4097 record_exports::record(&mut resolver);
4098 session.abort_if_errors();
4103 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }