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) {
495 execute_callback!(hir_map::Node::NodeVariant(variant), self);
496 if let Some(ref dis_expr) = variant.node.disr_expr {
497 // resolve the discriminator expr as a constant
498 self.with_constant_rib(|this| {
499 this.visit_expr(&**dis_expr);
503 // `visit::walk_variant` without the discriminant expression.
504 match variant.node.kind {
505 hir::TupleVariantKind(ref variant_arguments) => {
506 for variant_argument in variant_arguments {
507 self.visit_ty(&*variant_argument.ty);
510 hir::StructVariantKind(ref struct_definition) => {
511 self.visit_struct_def(&**struct_definition,
518 fn visit_foreign_item(&mut self, foreign_item: &hir::ForeignItem) {
519 execute_callback!(hir_map::Node::NodeForeignItem(foreign_item), self);
520 let type_parameters = match foreign_item.node {
521 ForeignItemFn(_, ref generics) => {
522 HasTypeParameters(generics, FnSpace, ItemRibKind)
524 ForeignItemStatic(..) => NoTypeParameters
526 self.with_type_parameter_rib(type_parameters, |this| {
527 visit::walk_foreign_item(this, foreign_item);
530 fn visit_fn(&mut self,
531 function_kind: FnKind<'v>,
532 declaration: &'v FnDecl,
536 let rib_kind = match function_kind {
537 FnKind::ItemFn(_, generics, _, _, _, _) => {
538 self.visit_generics(generics);
541 FnKind::Method(_, sig, _) => {
542 self.visit_generics(&sig.generics);
543 self.visit_explicit_self(&sig.explicit_self);
546 FnKind::Closure(..) => ClosureRibKind(node_id)
548 self.resolve_function(rib_kind, declaration, block);
552 type ErrorMessage = Option<(Span, String)>;
554 enum ResolveResult<T> {
555 Failed(ErrorMessage), // Failed to resolve the name, optional helpful error message.
556 Indeterminate, // Couldn't determine due to unresolved globs.
557 Success(T) // Successfully resolved the import.
560 impl<T> ResolveResult<T> {
561 fn success(&self) -> bool {
562 match *self { Success(_) => true, _ => false }
566 enum FallbackSuggestion {
571 StaticMethod(String),
575 #[derive(Copy, Clone)]
576 enum TypeParameters<'a> {
582 // Identifies the things that these parameters
583 // were declared on (type, fn, etc)
586 // The kind of the rib used for type parameters.
590 // The rib kind controls the translation of local
591 // definitions (`DefLocal`) to upvars (`DefUpvar`).
592 #[derive(Copy, Clone, Debug)]
594 // No translation needs to be applied.
597 // We passed through a closure scope at the given node ID.
598 // Translate upvars as appropriate.
599 ClosureRibKind(NodeId /* func id */),
601 // We passed through an impl or trait and are now in one of its
602 // methods. Allow references to ty params that impl or trait
603 // binds. Disallow any other upvars (including other ty params that are
607 // We passed through an item scope. Disallow upvars.
610 // We're in a constant item. Can't refer to dynamic stuff.
614 #[derive(Copy, Clone)]
615 enum UseLexicalScopeFlag {
620 enum ModulePrefixResult {
622 PrefixFound(Rc<Module>, usize)
625 #[derive(Copy, Clone)]
626 enum AssocItemResolveResult {
627 /// Syntax such as `<T>::item`, which can't be resolved until type
630 /// We should have been able to resolve the associated item.
631 ResolveAttempt(Option<PathResolution>),
634 #[derive(Copy, Clone, PartialEq)]
635 enum NameSearchType {
636 /// We're doing a name search in order to resolve a `use` directive.
639 /// We're doing a name search in order to resolve a path type, a path
640 /// expression, or a path pattern.
644 #[derive(Copy, Clone)]
645 enum BareIdentifierPatternResolution {
646 FoundStructOrEnumVariant(Def, LastPrivate),
647 FoundConst(Def, LastPrivate),
648 BareIdentifierPatternUnresolved
654 bindings: HashMap<Name, DefLike>,
659 fn new(kind: RibKind) -> Rib {
661 bindings: HashMap::new(),
667 /// The link from a module up to its nearest parent node.
668 #[derive(Clone,Debug)]
671 ModuleParentLink(Weak<Module>, Name),
672 BlockParentLink(Weak<Module>, NodeId)
675 /// The type of module this is.
676 #[derive(Copy, Clone, PartialEq, Debug)]
685 /// One node in the tree of modules.
687 parent_link: ParentLink,
688 def_id: Cell<Option<DefId>>,
689 kind: Cell<ModuleKind>,
692 children: RefCell<HashMap<Name, Rc<NameBindings>>>,
693 imports: RefCell<Vec<ImportDirective>>,
695 // The external module children of this node that were declared with
697 external_module_children: RefCell<HashMap<Name, Rc<Module>>>,
699 // The anonymous children of this node. Anonymous children are pseudo-
700 // modules that are implicitly created around items contained within
703 // For example, if we have this:
711 // There will be an anonymous module created around `g` with the ID of the
712 // entry block for `f`.
713 anonymous_children: RefCell<NodeMap<Rc<Module>>>,
715 // The status of resolving each import in this module.
716 import_resolutions: RefCell<HashMap<Name, ImportResolution>>,
718 // The number of unresolved globs that this module exports.
719 glob_count: Cell<usize>,
721 // The number of unresolved pub imports (both regular and globs) in this module
722 pub_count: Cell<usize>,
724 // The number of unresolved pub glob imports in this module
725 pub_glob_count: Cell<usize>,
727 // The index of the import we're resolving.
728 resolved_import_count: Cell<usize>,
730 // Whether this module is populated. If not populated, any attempt to
731 // access the children must be preceded with a
732 // `populate_module_if_necessary` call.
733 populated: Cell<bool>,
737 fn new(parent_link: ParentLink,
738 def_id: Option<DefId>,
744 parent_link: parent_link,
745 def_id: Cell::new(def_id),
746 kind: Cell::new(kind),
747 is_public: is_public,
748 children: RefCell::new(HashMap::new()),
749 imports: RefCell::new(Vec::new()),
750 external_module_children: RefCell::new(HashMap::new()),
751 anonymous_children: RefCell::new(NodeMap()),
752 import_resolutions: RefCell::new(HashMap::new()),
753 glob_count: Cell::new(0),
754 pub_count: Cell::new(0),
755 pub_glob_count: Cell::new(0),
756 resolved_import_count: Cell::new(0),
757 populated: Cell::new(!external),
761 fn all_imports_resolved(&self) -> bool {
762 if self.imports.borrow_state() == ::std::cell::BorrowState::Writing {
763 // it is currently being resolved ! so nope
766 self.imports.borrow().len() == self.resolved_import_count.get()
772 pub fn inc_glob_count(&self) {
773 self.glob_count.set(self.glob_count.get() + 1);
775 pub fn dec_glob_count(&self) {
776 assert!(self.glob_count.get() > 0);
777 self.glob_count.set(self.glob_count.get() - 1);
779 pub fn inc_pub_count(&self) {
780 self.pub_count.set(self.pub_count.get() + 1);
782 pub fn dec_pub_count(&self) {
783 assert!(self.pub_count.get() > 0);
784 self.pub_count.set(self.pub_count.get() - 1);
786 pub fn inc_pub_glob_count(&self) {
787 self.pub_glob_count.set(self.pub_glob_count.get() + 1);
789 pub fn dec_pub_glob_count(&self) {
790 assert!(self.pub_glob_count.get() > 0);
791 self.pub_glob_count.set(self.pub_glob_count.get() - 1);
795 impl fmt::Debug for Module {
796 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
797 write!(f, "{:?}, kind: {:?}, {}",
800 if self.is_public { "public" } else { "private" } )
806 flags DefModifiers: u8 {
807 const PUBLIC = 1 << 0,
808 const IMPORTABLE = 1 << 1,
812 // Records a possibly-private type definition.
813 #[derive(Clone,Debug)]
815 modifiers: DefModifiers, // see note in ImportResolution about how to use this
816 module_def: Option<Rc<Module>>,
817 type_def: Option<Def>,
818 type_span: Option<Span>
821 // Records a possibly-private value definition.
822 #[derive(Clone, Copy, Debug)]
824 modifiers: DefModifiers, // see note in ImportResolution about how to use this
826 value_span: Option<Span>,
829 // Records the definitions (at most one for each namespace) that a name is
832 pub struct NameBindings {
833 type_def: RefCell<Option<TypeNsDef>>, //< Meaning in type namespace.
834 value_def: RefCell<Option<ValueNsDef>>, //< Meaning in value namespace.
838 fn new() -> NameBindings {
840 type_def: RefCell::new(None),
841 value_def: RefCell::new(None),
845 /// Creates a new module in this set of name bindings.
846 fn define_module(&self,
847 parent_link: ParentLink,
848 def_id: Option<DefId>,
853 // Merges the module with the existing type def or creates a new one.
854 let modifiers = if is_public {
857 DefModifiers::empty()
858 } | DefModifiers::IMPORTABLE;
859 let module_ = Rc::new(Module::new(parent_link,
864 let type_def = self.type_def.borrow().clone();
867 *self.type_def.borrow_mut() = Some(TypeNsDef {
868 modifiers: modifiers,
869 module_def: Some(module_),
875 *self.type_def.borrow_mut() = Some(TypeNsDef {
876 modifiers: modifiers,
877 module_def: Some(module_),
879 type_def: type_def.type_def
885 /// Sets the kind of the module, creating a new one if necessary.
886 fn set_module_kind(&self,
887 parent_link: ParentLink,
888 def_id: Option<DefId>,
893 let modifiers = if is_public {
896 DefModifiers::empty()
897 } | DefModifiers::IMPORTABLE;
898 let type_def = self.type_def.borrow().clone();
901 let module = Module::new(parent_link,
906 *self.type_def.borrow_mut() = Some(TypeNsDef {
907 modifiers: modifiers,
908 module_def: Some(Rc::new(module)),
914 match type_def.module_def {
916 let module = Module::new(parent_link,
921 *self.type_def.borrow_mut() = Some(TypeNsDef {
922 modifiers: modifiers,
923 module_def: Some(Rc::new(module)),
924 type_def: type_def.type_def,
928 Some(module_def) => module_def.kind.set(kind),
934 /// Records a type definition.
935 fn define_type(&self, def: Def, sp: Span, modifiers: DefModifiers) {
936 debug!("defining type for def {:?} with modifiers {:?}", def, modifiers);
937 // Merges the type with the existing type def or creates a new one.
938 let type_def = self.type_def.borrow().clone();
941 *self.type_def.borrow_mut() = Some(TypeNsDef {
945 modifiers: modifiers,
949 *self.type_def.borrow_mut() = Some(TypeNsDef {
950 module_def: type_def.module_def,
953 modifiers: modifiers,
959 /// Records a value definition.
960 fn define_value(&self, def: Def, sp: Span, modifiers: DefModifiers) {
961 debug!("defining value for def {:?} with modifiers {:?}", def, modifiers);
962 *self.value_def.borrow_mut() = Some(ValueNsDef {
964 value_span: Some(sp),
965 modifiers: modifiers,
969 /// Returns the module node if applicable.
970 fn get_module_if_available(&self) -> Option<Rc<Module>> {
971 match *self.type_def.borrow() {
972 Some(ref type_def) => type_def.module_def.clone(),
977 /// Returns the module node. Panics if this node does not have a module
979 fn get_module(&self) -> Rc<Module> {
980 match self.get_module_if_available() {
982 panic!("get_module called on a node with no module \
985 Some(module_def) => module_def
989 fn defined_in_namespace(&self, namespace: Namespace) -> bool {
991 TypeNS => return self.type_def.borrow().is_some(),
992 ValueNS => return self.value_def.borrow().is_some()
996 fn defined_in_public_namespace(&self, namespace: Namespace) -> bool {
997 self.defined_in_namespace_with(namespace, DefModifiers::PUBLIC)
1000 fn defined_in_namespace_with(&self, namespace: Namespace, modifiers: DefModifiers) -> bool {
1002 TypeNS => match *self.type_def.borrow() {
1003 Some(ref def) => def.modifiers.contains(modifiers), None => false
1005 ValueNS => match *self.value_def.borrow() {
1006 Some(ref def) => def.modifiers.contains(modifiers), None => false
1011 fn def_for_namespace(&self, namespace: Namespace) -> Option<Def> {
1014 match *self.type_def.borrow() {
1016 Some(ref type_def) => {
1017 match type_def.type_def {
1018 Some(type_def) => Some(type_def),
1020 match type_def.module_def {
1021 Some(ref module) => {
1022 match module.def_id.get() {
1023 Some(did) => Some(DefMod(did)),
1035 match *self.value_def.borrow() {
1037 Some(value_def) => Some(value_def.def)
1043 fn span_for_namespace(&self, namespace: Namespace) -> Option<Span> {
1044 if self.defined_in_namespace(namespace) {
1047 match *self.type_def.borrow() {
1049 Some(ref type_def) => type_def.type_span
1053 match *self.value_def.borrow() {
1055 Some(ref value_def) => value_def.value_span
1064 fn is_public(&self, namespace: Namespace) -> bool {
1067 let type_def = self.type_def.borrow();
1068 type_def.as_ref().unwrap().modifiers.contains(DefModifiers::PUBLIC)
1071 let value_def = self.value_def.borrow();
1072 value_def.as_ref().unwrap().modifiers.contains(DefModifiers::PUBLIC)
1078 /// Interns the names of the primitive types.
1079 struct PrimitiveTypeTable {
1080 primitive_types: HashMap<Name, PrimTy>,
1083 impl PrimitiveTypeTable {
1084 fn new() -> PrimitiveTypeTable {
1085 let mut table = PrimitiveTypeTable {
1086 primitive_types: HashMap::new()
1089 table.intern("bool", TyBool);
1090 table.intern("char", TyChar);
1091 table.intern("f32", TyFloat(TyF32));
1092 table.intern("f64", TyFloat(TyF64));
1093 table.intern("isize", TyInt(TyIs));
1094 table.intern("i8", TyInt(TyI8));
1095 table.intern("i16", TyInt(TyI16));
1096 table.intern("i32", TyInt(TyI32));
1097 table.intern("i64", TyInt(TyI64));
1098 table.intern("str", TyStr);
1099 table.intern("usize", TyUint(TyUs));
1100 table.intern("u8", TyUint(TyU8));
1101 table.intern("u16", TyUint(TyU16));
1102 table.intern("u32", TyUint(TyU32));
1103 table.intern("u64", TyUint(TyU64));
1108 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1109 self.primitive_types.insert(token::intern(string), primitive_type);
1113 /// The main resolver class.
1114 pub struct Resolver<'a, 'tcx:'a> {
1115 session: &'a Session,
1117 ast_map: &'a hir_map::Map<'tcx>,
1119 graph_root: NameBindings,
1121 trait_item_map: FnvHashMap<(Name, DefId), DefId>,
1123 structs: FnvHashMap<DefId, Vec<Name>>,
1125 // The number of imports that are currently unresolved.
1126 unresolved_imports: usize,
1128 // The module that represents the current item scope.
1129 current_module: Rc<Module>,
1131 // The current set of local scopes, for values.
1132 // FIXME #4948: Reuse ribs to avoid allocation.
1133 value_ribs: Vec<Rib>,
1135 // The current set of local scopes, for types.
1136 type_ribs: Vec<Rib>,
1138 // The current set of local scopes, for labels.
1139 label_ribs: Vec<Rib>,
1141 // The trait that the current context can refer to.
1142 current_trait_ref: Option<(DefId, TraitRef)>,
1144 // The current self type if inside an impl (used for better errors).
1145 current_self_type: Option<Ty>,
1147 // The idents for the primitive types.
1148 primitive_type_table: PrimitiveTypeTable,
1151 freevars: RefCell<FreevarMap>,
1152 freevars_seen: RefCell<NodeMap<NodeMap<usize>>>,
1153 export_map: ExportMap,
1154 trait_map: TraitMap,
1155 external_exports: ExternalExports,
1157 // Whether or not to print error messages. Can be set to true
1158 // when getting additional info for error message suggestions,
1159 // so as to avoid printing duplicate errors
1162 make_glob_map: bool,
1163 // Maps imports to the names of items actually imported (this actually maps
1164 // all imports, but only glob imports are actually interesting).
1167 used_imports: HashSet<(NodeId, Namespace)>,
1168 used_crates: HashSet<CrateNum>,
1170 // Callback function for intercepting walks
1171 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>,
1172 // The intention is that the callback modifies this flag.
1173 // Once set, the resolver falls out of the walk, preserving the ribs.
1178 #[derive(PartialEq)]
1179 enum FallbackChecks {
1184 impl<'a, 'tcx> Resolver<'a, 'tcx> {
1185 fn new(session: &'a Session,
1186 ast_map: &'a hir_map::Map<'tcx>,
1188 make_glob_map: MakeGlobMap) -> Resolver<'a, 'tcx> {
1189 let graph_root = NameBindings::new();
1191 let root_def_id = ast_map.local_def_id(CRATE_NODE_ID);
1192 graph_root.define_module(NoParentLink,
1199 let current_module = graph_root.get_module();
1206 // The outermost module has def ID 0; this is not reflected in the
1209 graph_root: graph_root,
1211 trait_item_map: FnvHashMap(),
1212 structs: FnvHashMap(),
1214 unresolved_imports: 0,
1216 current_module: current_module,
1217 value_ribs: Vec::new(),
1218 type_ribs: Vec::new(),
1219 label_ribs: Vec::new(),
1221 current_trait_ref: None,
1222 current_self_type: None,
1224 primitive_type_table: PrimitiveTypeTable::new(),
1226 def_map: RefCell::new(NodeMap()),
1227 freevars: RefCell::new(NodeMap()),
1228 freevars_seen: RefCell::new(NodeMap()),
1229 export_map: NodeMap(),
1230 trait_map: NodeMap(),
1231 used_imports: HashSet::new(),
1232 used_crates: HashSet::new(),
1233 external_exports: DefIdSet(),
1236 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1237 glob_map: HashMap::new(),
1246 fn record_import_use(&mut self, import_id: NodeId, name: Name) {
1247 if !self.make_glob_map {
1250 if self.glob_map.contains_key(&import_id) {
1251 self.glob_map.get_mut(&import_id).unwrap().insert(name);
1255 let mut new_set = HashSet::new();
1256 new_set.insert(name);
1257 self.glob_map.insert(import_id, new_set);
1260 fn get_trait_name(&self, did: DefId) -> Name {
1261 if let Some(node_id) = self.ast_map.as_local_node_id(did) {
1262 self.ast_map.expect_item(node_id).name
1264 csearch::get_trait_name(&self.session.cstore, did)
1268 fn create_name_bindings_from_module(module: Rc<Module>) -> NameBindings {
1270 type_def: RefCell::new(Some(TypeNsDef {
1271 modifiers: DefModifiers::IMPORTABLE,
1272 module_def: Some(module),
1276 value_def: RefCell::new(None),
1280 /// Checks that the names of external crates don't collide with other
1281 /// external crates.
1282 fn check_for_conflicts_between_external_crates(&self,
1286 if module.external_module_children.borrow().contains_key(&name) {
1287 span_err!(self.session, span, E0259,
1288 "an external crate named `{}` has already \
1289 been imported into this module",
1294 /// Checks that the names of items don't collide with external crates.
1295 fn check_for_conflicts_between_external_crates_and_items(&self,
1299 if module.external_module_children.borrow().contains_key(&name) {
1300 span_err!(self.session, span, E0260,
1301 "the name `{}` conflicts with an external \
1302 crate that has been imported into this \
1308 /// Resolves the given module path from the given root `module_`.
1309 fn resolve_module_path_from_root(&mut self,
1310 module_: Rc<Module>,
1311 module_path: &[Name],
1314 name_search_type: NameSearchType,
1316 -> ResolveResult<(Rc<Module>, LastPrivate)> {
1317 fn search_parent_externals(needle: Name, module: &Rc<Module>)
1318 -> Option<Rc<Module>> {
1319 match module.external_module_children.borrow().get(&needle) {
1320 Some(_) => Some(module.clone()),
1321 None => match module.parent_link {
1322 ModuleParentLink(ref parent, _) => {
1323 search_parent_externals(needle, &parent.upgrade().unwrap())
1330 let mut search_module = module_;
1331 let mut index = index;
1332 let module_path_len = module_path.len();
1333 let mut closest_private = lp;
1335 // Resolve the module part of the path. This does not involve looking
1336 // upward though scope chains; we simply resolve names directly in
1337 // modules as we go.
1338 while index < module_path_len {
1339 let name = module_path[index];
1340 match self.resolve_name_in_module(search_module.clone(),
1346 let segment_name = name.as_str();
1347 let module_name = module_to_string(&*search_module);
1348 let mut span = span;
1349 let msg = if "???" == &module_name[..] {
1350 span.hi = span.lo + Pos::from_usize(segment_name.len());
1352 match search_parent_externals(name,
1353 &self.current_module) {
1355 let path_str = names_to_string(module_path);
1356 let target_mod_str = module_to_string(&*module);
1357 let current_mod_str =
1358 module_to_string(&*self.current_module);
1360 let prefix = if target_mod_str == current_mod_str {
1361 "self::".to_string()
1363 format!("{}::", target_mod_str)
1366 format!("Did you mean `{}{}`?", prefix, path_str)
1368 None => format!("Maybe a missing `extern crate {}`?",
1372 format!("Could not find `{}` in `{}`",
1377 return Failed(Some((span, msg)));
1379 Failed(err) => return Failed(err),
1381 debug!("(resolving module path for import) module \
1382 resolution is indeterminate: {}",
1384 return Indeterminate;
1386 Success((target, used_proxy)) => {
1387 // Check to see whether there are type bindings, and, if
1388 // so, whether there is a module within.
1389 match *target.bindings.type_def.borrow() {
1390 Some(ref type_def) => {
1391 match type_def.module_def {
1393 let msg = format!("Not a module `{}`",
1396 return Failed(Some((span, msg)));
1398 Some(ref module_def) => {
1399 search_module = module_def.clone();
1401 // track extern crates for unused_extern_crate lint
1402 if let Some(did) = module_def.def_id.get() {
1403 self.used_crates.insert(did.krate);
1406 // Keep track of the closest
1407 // private module used when
1408 // resolving this import chain.
1409 if !used_proxy && !search_module.is_public {
1410 if let Some(did) = search_module.def_id.get() {
1411 closest_private = LastMod(DependsOn(did));
1418 // There are no type bindings at all.
1419 let msg = format!("Not a module `{}`",
1421 return Failed(Some((span, msg)));
1430 return Success((search_module, closest_private));
1433 /// Attempts to resolve the module part of an import directive or path
1434 /// rooted at the given module.
1436 /// On success, returns the resolved module, and the closest *private*
1437 /// module found to the destination when resolving this path.
1438 fn resolve_module_path(&mut self,
1439 module_: Rc<Module>,
1440 module_path: &[Name],
1441 use_lexical_scope: UseLexicalScopeFlag,
1443 name_search_type: NameSearchType)
1444 -> ResolveResult<(Rc<Module>, LastPrivate)> {
1445 let module_path_len = module_path.len();
1446 assert!(module_path_len > 0);
1448 debug!("(resolving module path for import) processing `{}` rooted at `{}`",
1449 names_to_string(module_path),
1450 module_to_string(&*module_));
1452 // Resolve the module prefix, if any.
1453 let module_prefix_result = self.resolve_module_prefix(module_.clone(),
1459 match module_prefix_result {
1461 let mpath = names_to_string(module_path);
1462 let mpath = &mpath[..];
1463 match mpath.rfind(':') {
1465 let msg = format!("Could not find `{}` in `{}`",
1466 // idx +- 1 to account for the
1467 // colons on either side
1470 return Failed(Some((span, msg)));
1477 Failed(err) => return Failed(err),
1479 debug!("(resolving module path for import) indeterminate; \
1481 return Indeterminate;
1483 Success(NoPrefixFound) => {
1484 // There was no prefix, so we're considering the first element
1485 // of the path. How we handle this depends on whether we were
1486 // instructed to use lexical scope or not.
1487 match use_lexical_scope {
1488 DontUseLexicalScope => {
1489 // This is a crate-relative path. We will start the
1490 // resolution process at index zero.
1491 search_module = self.graph_root.get_module();
1493 last_private = LastMod(AllPublic);
1495 UseLexicalScope => {
1496 // This is not a crate-relative path. We resolve the
1497 // first component of the path in the current lexical
1498 // scope and then proceed to resolve below that.
1499 match self.resolve_module_in_lexical_scope(module_,
1501 Failed(err) => return Failed(err),
1503 debug!("(resolving module path for import) \
1504 indeterminate; bailing");
1505 return Indeterminate;
1507 Success(containing_module) => {
1508 search_module = containing_module;
1510 last_private = LastMod(AllPublic);
1516 Success(PrefixFound(ref containing_module, index)) => {
1517 search_module = containing_module.clone();
1518 start_index = index;
1519 last_private = LastMod(DependsOn(containing_module.def_id
1525 self.resolve_module_path_from_root(search_module,
1533 /// Invariant: This must only be called during main resolution, not during
1534 /// import resolution.
1535 fn resolve_item_in_lexical_scope(&mut self,
1536 module_: Rc<Module>,
1538 namespace: Namespace)
1539 -> ResolveResult<(Target, bool)> {
1540 debug!("(resolving item in lexical scope) resolving `{}` in \
1541 namespace {:?} in `{}`",
1544 module_to_string(&*module_));
1546 // The current module node is handled specially. First, check for
1547 // its immediate children.
1548 build_reduced_graph::populate_module_if_necessary(self, &module_);
1550 match module_.children.borrow().get(&name) {
1552 if name_bindings.defined_in_namespace(namespace) => {
1553 debug!("top name bindings succeeded");
1554 return Success((Target::new(module_.clone(),
1555 name_bindings.clone(),
1559 Some(_) | None => { /* Not found; continue. */ }
1562 // Now check for its import directives. We don't have to have resolved
1563 // all its imports in the usual way; this is because chains of
1564 // adjacent import statements are processed as though they mutated the
1566 if let Some(import_resolution) = module_.import_resolutions.borrow().get(&name) {
1567 match (*import_resolution).target_for_namespace(namespace) {
1569 // Not found; continue.
1570 debug!("(resolving item in lexical scope) found \
1571 import resolution, but not in namespace {:?}",
1575 debug!("(resolving item in lexical scope) using \
1576 import resolution");
1577 // track used imports and extern crates as well
1578 let id = import_resolution.id(namespace);
1579 self.used_imports.insert((id, namespace));
1580 self.record_import_use(id, name);
1581 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id.get() {
1582 self.used_crates.insert(kid);
1584 return Success((target, false));
1589 // Search for external modules.
1590 if namespace == TypeNS {
1591 // FIXME (21114): In principle unclear `child` *has* to be lifted.
1592 let child = module_.external_module_children.borrow().get(&name).cloned();
1593 if let Some(module) = child {
1595 Rc::new(Resolver::create_name_bindings_from_module(module));
1596 debug!("lower name bindings succeeded");
1597 return Success((Target::new(module_,
1604 // Finally, proceed up the scope chain looking for parent modules.
1605 let mut search_module = module_;
1607 // Go to the next parent.
1608 match search_module.parent_link.clone() {
1610 // No more parents. This module was unresolved.
1611 debug!("(resolving item in lexical scope) unresolved \
1613 return Failed(None);
1615 ModuleParentLink(parent_module_node, _) => {
1616 match search_module.kind.get() {
1617 NormalModuleKind => {
1618 // We stop the search here.
1619 debug!("(resolving item in lexical \
1620 scope) unresolved module: not \
1621 searching through module \
1623 return Failed(None);
1628 AnonymousModuleKind => {
1629 search_module = parent_module_node.upgrade().unwrap();
1633 BlockParentLink(ref parent_module_node, _) => {
1634 search_module = parent_module_node.upgrade().unwrap();
1638 // Resolve the name in the parent module.
1639 match self.resolve_name_in_module(search_module.clone(),
1644 Failed(Some((span, msg))) => {
1645 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
1647 Failed(None) => (), // Continue up the search chain.
1649 // We couldn't see through the higher scope because of an
1650 // unresolved import higher up. Bail.
1652 debug!("(resolving item in lexical scope) indeterminate \
1653 higher scope; bailing");
1654 return Indeterminate;
1656 Success((target, used_reexport)) => {
1657 // We found the module.
1658 debug!("(resolving item in lexical scope) found name \
1660 return Success((target, used_reexport));
1666 /// Resolves a module name in the current lexical scope.
1667 fn resolve_module_in_lexical_scope(&mut self,
1668 module_: Rc<Module>,
1670 -> ResolveResult<Rc<Module>> {
1671 // If this module is an anonymous module, resolve the item in the
1672 // lexical scope. Otherwise, resolve the item from the crate root.
1673 let resolve_result = self.resolve_item_in_lexical_scope(module_, name, TypeNS);
1674 match resolve_result {
1675 Success((target, _)) => {
1676 let bindings = &*target.bindings;
1677 match *bindings.type_def.borrow() {
1678 Some(ref type_def) => {
1679 match type_def.module_def {
1681 debug!("!!! (resolving module in lexical \
1682 scope) module wasn't actually a \
1684 return Failed(None);
1686 Some(ref module_def) => {
1687 return Success(module_def.clone());
1692 debug!("!!! (resolving module in lexical scope) module
1693 wasn't actually a module!");
1694 return Failed(None);
1699 debug!("(resolving module in lexical scope) indeterminate; \
1701 return Indeterminate;
1704 debug!("(resolving module in lexical scope) failed to resolve");
1710 /// Returns the nearest normal module parent of the given module.
1711 fn get_nearest_normal_module_parent(&mut self, module_: Rc<Module>)
1712 -> Option<Rc<Module>> {
1713 let mut module_ = module_;
1715 match module_.parent_link.clone() {
1716 NoParentLink => return None,
1717 ModuleParentLink(new_module, _) |
1718 BlockParentLink(new_module, _) => {
1719 let new_module = new_module.upgrade().unwrap();
1720 match new_module.kind.get() {
1721 NormalModuleKind => return Some(new_module),
1725 AnonymousModuleKind => module_ = new_module,
1732 /// Returns the nearest normal module parent of the given module, or the
1733 /// module itself if it is a normal module.
1734 fn get_nearest_normal_module_parent_or_self(&mut self, module_: Rc<Module>)
1736 match module_.kind.get() {
1737 NormalModuleKind => return module_,
1741 AnonymousModuleKind => {
1742 match self.get_nearest_normal_module_parent(module_.clone()) {
1744 Some(new_module) => new_module
1750 /// Resolves a "module prefix". A module prefix is one or both of (a) `self::`;
1751 /// (b) some chain of `super::`.
1752 /// grammar: (SELF MOD_SEP ) ? (SUPER MOD_SEP) *
1753 fn resolve_module_prefix(&mut self,
1754 module_: Rc<Module>,
1755 module_path: &[Name])
1756 -> ResolveResult<ModulePrefixResult> {
1757 // Start at the current module if we see `self` or `super`, or at the
1758 // top of the crate otherwise.
1759 let mut i = match &*module_path[0].as_str() {
1762 _ => return Success(NoPrefixFound),
1764 let mut containing_module = self.get_nearest_normal_module_parent_or_self(module_);
1766 // Now loop through all the `super`s we find.
1767 while i < module_path.len() && "super" == module_path[i].as_str() {
1768 debug!("(resolving module prefix) resolving `super` at {}",
1769 module_to_string(&*containing_module));
1770 match self.get_nearest_normal_module_parent(containing_module) {
1771 None => return Failed(None),
1772 Some(new_module) => {
1773 containing_module = new_module;
1779 debug!("(resolving module prefix) finished resolving prefix at {}",
1780 module_to_string(&*containing_module));
1782 return Success(PrefixFound(containing_module, i));
1785 /// Attempts to resolve the supplied name in the given module for the
1786 /// given namespace. If successful, returns the target corresponding to
1789 /// The boolean returned on success is an indicator of whether this lookup
1790 /// passed through a public re-export proxy.
1791 fn resolve_name_in_module(&mut self,
1792 module_: Rc<Module>,
1794 namespace: Namespace,
1795 name_search_type: NameSearchType,
1796 allow_private_imports: bool)
1797 -> ResolveResult<(Target, bool)> {
1798 debug!("(resolving name in module) resolving `{}` in `{}`",
1800 module_to_string(&*module_));
1802 // First, check the direct children of the module.
1803 build_reduced_graph::populate_module_if_necessary(self, &module_);
1805 match module_.children.borrow().get(&name) {
1807 if name_bindings.defined_in_namespace(namespace) => {
1808 debug!("(resolving name in module) found node as child");
1809 return Success((Target::new(module_.clone(),
1810 name_bindings.clone(),
1819 // Next, check the module's imports if necessary.
1821 // If this is a search of all imports, we should be done with glob
1822 // resolution at this point.
1823 if name_search_type == PathSearch {
1824 assert_eq!(module_.glob_count.get(), 0);
1827 // Check the list of resolved imports.
1828 match module_.import_resolutions.borrow().get(&name) {
1829 Some(import_resolution) if allow_private_imports ||
1830 import_resolution.is_public => {
1832 if import_resolution.is_public &&
1833 import_resolution.outstanding_references != 0 {
1834 debug!("(resolving name in module) import \
1835 unresolved; bailing out");
1836 return Indeterminate;
1838 match import_resolution.target_for_namespace(namespace) {
1840 debug!("(resolving name in module) name found, \
1841 but not in namespace {:?}",
1845 debug!("(resolving name in module) resolved to \
1847 // track used imports and extern crates as well
1848 let id = import_resolution.id(namespace);
1849 self.used_imports.insert((id, namespace));
1850 self.record_import_use(id, name);
1851 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id.get() {
1852 self.used_crates.insert(kid);
1854 return Success((target, true));
1858 Some(..) | None => {} // Continue.
1861 // Finally, search through external children.
1862 if namespace == TypeNS {
1863 // FIXME (21114): In principle unclear `child` *has* to be lifted.
1864 let child = module_.external_module_children.borrow().get(&name).cloned();
1865 if let Some(module) = child {
1867 Rc::new(Resolver::create_name_bindings_from_module(module));
1868 return Success((Target::new(module_,
1875 // We're out of luck.
1876 debug!("(resolving name in module) failed to resolve `{}`",
1878 return Failed(None);
1881 fn report_unresolved_imports(&mut self, module_: Rc<Module>) {
1882 let index = module_.resolved_import_count.get();
1883 let imports = module_.imports.borrow();
1884 let import_count = imports.len();
1885 if index != import_count {
1887 (*imports)[index].span,
1888 ResolutionError::UnresolvedImport(None));
1891 // Descend into children and anonymous children.
1892 build_reduced_graph::populate_module_if_necessary(self, &module_);
1894 for (_, child_node) in module_.children.borrow().iter() {
1895 match child_node.get_module_if_available() {
1899 Some(child_module) => {
1900 self.report_unresolved_imports(child_module);
1905 for (_, module_) in module_.anonymous_children.borrow().iter() {
1906 self.report_unresolved_imports(module_.clone());
1912 // We maintain a list of value ribs and type ribs.
1914 // Simultaneously, we keep track of the current position in the module
1915 // graph in the `current_module` pointer. When we go to resolve a name in
1916 // the value or type namespaces, we first look through all the ribs and
1917 // then query the module graph. When we resolve a name in the module
1918 // namespace, we can skip all the ribs (since nested modules are not
1919 // allowed within blocks in Rust) and jump straight to the current module
1922 // Named implementations are handled separately. When we find a method
1923 // call, we consult the module node to find all of the implementations in
1924 // scope. This information is lazily cached in the module node. We then
1925 // generate a fake "implementation scope" containing all the
1926 // implementations thus found, for compatibility with old resolve pass.
1928 fn with_scope<F>(&mut self, name: Option<Name>, f: F) where
1929 F: FnOnce(&mut Resolver),
1931 let orig_module = self.current_module.clone();
1933 // Move down in the graph.
1939 build_reduced_graph::populate_module_if_necessary(self, &orig_module);
1941 match orig_module.children.borrow().get(&name) {
1943 debug!("!!! (with scope) didn't find `{}` in `{}`",
1945 module_to_string(&*orig_module));
1947 Some(name_bindings) => {
1948 match (*name_bindings).get_module_if_available() {
1950 debug!("!!! (with scope) didn't find module \
1953 module_to_string(&*orig_module));
1956 self.current_module = module_;
1966 self.current_module = orig_module;
1969 /// Wraps the given definition in the appropriate number of `DefUpvar`
1975 -> Option<DefLike> {
1976 let mut def = match def_like {
1978 _ => return Some(def_like)
1982 self.session.span_bug(span,
1983 &format!("unexpected {:?} in bindings", def))
1985 DefLocal(node_id) => {
1989 // Nothing to do. Continue.
1991 ClosureRibKind(function_id) => {
1994 let mut seen = self.freevars_seen.borrow_mut();
1995 let seen = seen.entry(function_id).or_insert_with(|| NodeMap());
1996 if let Some(&index) = seen.get(&node_id) {
1997 def = DefUpvar(node_id, index, function_id);
2000 let mut freevars = self.freevars.borrow_mut();
2001 let vec = freevars.entry(function_id)
2002 .or_insert_with(|| vec![]);
2003 let depth = vec.len();
2004 vec.push(Freevar { def: prev_def, span: span });
2006 def = DefUpvar(node_id, depth, function_id);
2007 seen.insert(node_id, depth);
2009 ItemRibKind | MethodRibKind => {
2010 // This was an attempt to access an upvar inside a
2011 // named function item. This is not allowed, so we
2016 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem
2020 ConstantItemRibKind => {
2021 // Still doesn't deal with upvars
2025 ResolutionError::AttemptToUseNonConstantValueInConstant
2032 DefTyParam(..) | DefSelfTy(..) => {
2035 NormalRibKind | MethodRibKind | ClosureRibKind(..) => {
2036 // Nothing to do. Continue.
2039 // This was an attempt to use a type parameter outside
2044 ResolutionError::TypeParametersFromOuterFunction);
2047 ConstantItemRibKind => {
2049 resolve_error(self, span, ResolutionError::OuterTypeParameterContext);
2060 /// Searches the current set of local scopes and
2061 /// applies translations for closures.
2062 fn search_ribs(&self,
2066 -> Option<DefLike> {
2067 // FIXME #4950: Try caching?
2069 for (i, rib) in ribs.iter().enumerate().rev() {
2070 if let Some(def_like) = rib.bindings.get(&name).cloned() {
2071 return self.upvarify(&ribs[i + 1..], def_like, span);
2078 /// Searches the current set of local scopes for labels.
2079 /// Stops after meeting a closure.
2080 fn search_label(&self, name: Name) -> Option<DefLike> {
2081 for rib in self.label_ribs.iter().rev() {
2087 // Do not resolve labels across function boundary
2091 let result = rib.bindings.get(&name).cloned();
2092 if result.is_some() {
2099 fn resolve_crate(&mut self, krate: &hir::Crate) {
2100 debug!("(resolving crate) starting");
2102 visit::walk_crate(self, krate);
2105 fn check_if_primitive_type_name(&self, name: Name, span: Span) {
2106 if let Some(_) = self.primitive_type_table.primitive_types.get(&name) {
2107 span_err!(self.session, span, E0317,
2108 "user-defined types or type parameters cannot shadow the primitive types");
2112 fn resolve_item(&mut self, item: &Item) {
2113 let name = item.name;
2115 debug!("(resolving item) resolving {}",
2119 ItemEnum(_, ref generics) |
2120 ItemTy(_, ref generics) |
2121 ItemStruct(_, ref generics) => {
2122 self.check_if_primitive_type_name(name, item.span);
2124 self.with_type_parameter_rib(HasTypeParameters(generics,
2127 |this| visit::walk_item(this, item));
2129 ItemFn(_, _, _, _, ref generics, _) => {
2130 self.with_type_parameter_rib(HasTypeParameters(generics,
2133 |this| visit::walk_item(this, item));
2136 ItemDefaultImpl(_, ref trait_ref) => {
2137 self.with_optional_trait_ref(Some(trait_ref), |_, _| {});
2144 ref impl_items) => {
2145 self.resolve_implementation(generics,
2152 ItemTrait(_, ref generics, ref bounds, ref trait_items) => {
2153 self.check_if_primitive_type_name(name, item.span);
2155 // Create a new rib for the trait-wide type parameters.
2156 self.with_type_parameter_rib(HasTypeParameters(generics,
2160 let local_def_id = this.ast_map.local_def_id(item.id);
2161 this.with_self_rib(DefSelfTy(Some(local_def_id), None), |this| {
2162 this.visit_generics(generics);
2163 walk_list!(this, visit_ty_param_bound, bounds);
2165 for trait_item in trait_items {
2166 match trait_item.node {
2167 hir::ConstTraitItem(_, ref default) => {
2168 // Only impose the restrictions of
2169 // ConstRibKind if there's an actual constant
2170 // expression in a provided default.
2171 if default.is_some() {
2172 this.with_constant_rib(|this| {
2173 visit::walk_trait_item(this, trait_item)
2176 visit::walk_trait_item(this, trait_item)
2179 hir::MethodTraitItem(ref sig, _) => {
2180 let type_parameters =
2181 HasTypeParameters(&sig.generics,
2184 this.with_type_parameter_rib(type_parameters, |this| {
2185 visit::walk_trait_item(this, trait_item)
2188 hir::TypeTraitItem(..) => {
2189 this.check_if_primitive_type_name(trait_item.name,
2191 this.with_type_parameter_rib(NoTypeParameters, |this| {
2192 visit::walk_trait_item(this, trait_item)
2201 ItemMod(_) | ItemForeignMod(_) => {
2202 self.with_scope(Some(name), |this| {
2203 visit::walk_item(this, item);
2207 ItemConst(..) | ItemStatic(..) => {
2208 self.with_constant_rib(|this| {
2209 visit::walk_item(this, item);
2213 ItemUse(ref view_path) => {
2214 // check for imports shadowing primitive types
2215 let check_rename = |this: &Self, id, name| {
2216 match this.def_map.borrow().get(&id).map(|d| d.full_def()) {
2217 Some(DefTy(..)) | Some(DefStruct(..)) | Some(DefTrait(..)) | None => {
2218 this.check_if_primitive_type_name(name, item.span);
2224 match view_path.node {
2225 hir::ViewPathSimple(name, _) => {
2226 check_rename(self, item.id, name);
2228 hir::ViewPathList(ref prefix, ref items) => {
2230 if let Some(name) = item.node.rename() {
2231 check_rename(self, item.node.id(), name);
2235 // Resolve prefix of an import with empty braces (issue #28388)
2236 if items.is_empty() && !prefix.segments.is_empty() {
2237 match self.resolve_crate_relative_path(prefix.span,
2240 Some((def, lp)) => self.record_def(item.id,
2241 PathResolution::new(def, lp, 0)),
2245 ResolutionError::FailedToResolve(
2246 &path_names_to_string(prefix, 0)));
2255 ItemExternCrate(_) => {
2256 // do nothing, these are just around to be encoded
2261 fn with_type_parameter_rib<F>(&mut self, type_parameters: TypeParameters, f: F) where
2262 F: FnOnce(&mut Resolver),
2264 match type_parameters {
2265 HasTypeParameters(generics, space, rib_kind) => {
2266 let mut function_type_rib = Rib::new(rib_kind);
2267 let mut seen_bindings = HashSet::new();
2268 for (index, type_parameter) in generics.ty_params.iter().enumerate() {
2269 let name = type_parameter.name;
2270 debug!("with_type_parameter_rib: {}", type_parameter.id);
2272 if seen_bindings.contains(&name) {
2274 type_parameter.span,
2275 ResolutionError::NameAlreadyUsedInTypeParameterList(
2279 seen_bindings.insert(name);
2281 // plain insert (no renaming)
2282 function_type_rib.bindings.insert(name,
2283 DlDef(DefTyParam(space,
2285 self.ast_map.local_def_id(type_parameter.id),
2288 self.type_ribs.push(function_type_rib);
2291 NoTypeParameters => {
2298 match type_parameters {
2299 HasTypeParameters(..) => { if !self.resolved { self.type_ribs.pop(); } }
2300 NoTypeParameters => { }
2304 fn with_label_rib<F>(&mut self, f: F) where
2305 F: FnOnce(&mut Resolver),
2307 self.label_ribs.push(Rib::new(NormalRibKind));
2310 self.label_ribs.pop();
2314 fn with_constant_rib<F>(&mut self, f: F) where
2315 F: FnOnce(&mut Resolver),
2317 self.value_ribs.push(Rib::new(ConstantItemRibKind));
2318 self.type_ribs.push(Rib::new(ConstantItemRibKind));
2321 self.type_ribs.pop();
2322 self.value_ribs.pop();
2326 fn resolve_function(&mut self,
2328 declaration: &FnDecl,
2330 // Create a value rib for the function.
2331 self.value_ribs.push(Rib::new(rib_kind));
2333 // Create a label rib for the function.
2334 self.label_ribs.push(Rib::new(rib_kind));
2336 // Add each argument to the rib.
2337 let mut bindings_list = HashMap::new();
2338 for argument in &declaration.inputs {
2339 self.resolve_pattern(&*argument.pat,
2340 ArgumentIrrefutableMode,
2341 &mut bindings_list);
2343 self.visit_ty(&*argument.ty);
2345 debug!("(resolving function) recorded argument");
2347 visit::walk_fn_ret_ty(self, &declaration.output);
2349 // Resolve the function body.
2350 self.visit_block(&*block);
2352 debug!("(resolving function) leaving function");
2355 self.label_ribs.pop();
2356 self.value_ribs.pop();
2360 fn resolve_trait_reference(&mut self,
2364 -> Result<PathResolution, ()> {
2365 if let Some(path_res) = self.resolve_path(id, trait_path, path_depth, TypeNS, true) {
2366 if let DefTrait(_) = path_res.base_def {
2367 debug!("(resolving trait) found trait def: {:?}", path_res);
2372 ResolutionError::IsNotATrait(&*path_names_to_string(trait_path,
2376 // If it's a typedef, give a note
2377 if let DefTy(..) = path_res.base_def {
2378 self.session.span_note(trait_path.span,
2379 "`type` aliases cannot be used for traits");
2386 ResolutionError::UndeclaredTraitName(
2387 &*path_names_to_string(trait_path, path_depth))
2393 fn resolve_generics(&mut self, generics: &Generics) {
2394 for type_parameter in generics.ty_params.iter() {
2395 self.check_if_primitive_type_name(type_parameter.name, type_parameter.span);
2397 for predicate in &generics.where_clause.predicates {
2399 &hir::WherePredicate::BoundPredicate(_) |
2400 &hir::WherePredicate::RegionPredicate(_) => {}
2401 &hir::WherePredicate::EqPredicate(ref eq_pred) => {
2402 let path_res = self.resolve_path(eq_pred.id, &eq_pred.path, 0, TypeNS, true);
2403 if let Some(PathResolution { base_def: DefTyParam(..), .. }) = path_res {
2404 self.record_def(eq_pred.id, path_res.unwrap());
2408 ResolutionError::UndeclaredAssociatedType);
2413 visit::walk_generics(self, generics);
2416 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2417 where F: FnOnce(&mut Resolver) -> T
2419 // Handle nested impls (inside fn bodies)
2420 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2421 let result = f(self);
2422 self.current_self_type = previous_value;
2426 fn with_optional_trait_ref<T, F>(&mut self,
2427 opt_trait_ref: Option<&TraitRef>,
2430 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2432 let mut new_val = None;
2433 let mut new_id = None;
2434 if let Some(trait_ref) = opt_trait_ref {
2435 if let Ok(path_res) = self.resolve_trait_reference(trait_ref.ref_id,
2436 &trait_ref.path, 0) {
2437 assert!(path_res.depth == 0);
2438 self.record_def(trait_ref.ref_id, path_res);
2439 new_val = Some((path_res.base_def.def_id(), trait_ref.clone()));
2440 new_id = Some(path_res.base_def.def_id());
2442 visit::walk_trait_ref(self, trait_ref);
2444 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2445 let result = f(self, new_id);
2446 self.current_trait_ref = original_trait_ref;
2450 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2451 where F: FnOnce(&mut Resolver)
2453 let mut self_type_rib = Rib::new(NormalRibKind);
2455 // plain insert (no renaming, types are not currently hygienic....)
2456 let name = special_names::type_self;
2457 self_type_rib.bindings.insert(name, DlDef(self_def));
2458 self.type_ribs.push(self_type_rib);
2461 self.type_ribs.pop();
2465 fn resolve_implementation(&mut self,
2466 generics: &Generics,
2467 opt_trait_reference: &Option<TraitRef>,
2470 impl_items: &[P<ImplItem>]) {
2471 // If applicable, create a rib for the type parameters.
2472 self.with_type_parameter_rib(HasTypeParameters(generics,
2476 // Resolve the type parameters.
2477 this.visit_generics(generics);
2479 // Resolve the trait reference, if necessary.
2480 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2481 // Resolve the self type.
2482 this.visit_ty(self_type);
2484 this.with_self_rib(DefSelfTy(trait_id, Some((item_id, self_type.id))), |this| {
2485 this.with_current_self_type(self_type, |this| {
2486 for impl_item in impl_items {
2487 match impl_item.node {
2488 ConstImplItem(..) => {
2489 // If this is a trait impl, ensure the const
2491 this.check_trait_item(impl_item.name,
2493 |n, s| ResolutionError::ConstNotMemberOfTrait(n, s));
2494 this.with_constant_rib(|this| {
2495 visit::walk_impl_item(this, impl_item);
2498 MethodImplItem(ref sig, _) => {
2499 // If this is a trait impl, ensure the method
2501 this.check_trait_item(impl_item.name,
2503 |n, s| ResolutionError::MethodNotMemberOfTrait(n, s));
2505 // We also need a new scope for the method-
2506 // specific type parameters.
2507 let type_parameters =
2508 HasTypeParameters(&sig.generics,
2511 this.with_type_parameter_rib(type_parameters, |this| {
2512 visit::walk_impl_item(this, impl_item);
2515 TypeImplItem(ref ty) => {
2516 // If this is a trait impl, ensure the type
2518 this.check_trait_item(impl_item.name,
2520 |n, s| ResolutionError::TypeNotMemberOfTrait(n, s));
2532 fn check_trait_item<F>(&self, name: Name, span: Span, err: F)
2533 where F: FnOnce(Name, &str) -> ResolutionError {
2534 // If there is a TraitRef in scope for an impl, then the method must be in the trait.
2535 if let Some((did, ref trait_ref)) = self.current_trait_ref {
2536 if !self.trait_item_map.contains_key(&(name, did)) {
2537 let path_str = path_names_to_string(&trait_ref.path, 0);
2540 err(name, &*path_str));
2545 fn resolve_local(&mut self, local: &Local) {
2546 // Resolve the type.
2547 walk_list!(self, visit_ty, &local.ty);
2549 // Resolve the initializer.
2550 walk_list!(self, visit_expr, &local.init);
2552 // Resolve the pattern.
2553 self.resolve_pattern(&*local.pat,
2554 LocalIrrefutableMode,
2555 &mut HashMap::new());
2558 // build a map from pattern identifiers to binding-info's.
2559 // this is done hygienically. This could arise for a macro
2560 // that expands into an or-pattern where one 'x' was from the
2561 // user and one 'x' came from the macro.
2562 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2563 let mut result = HashMap::new();
2564 pat_bindings_hygienic(&self.def_map, pat, |binding_mode, _id, sp, path1| {
2565 let name = mtwt::resolve(path1.node);
2566 result.insert(name, BindingInfo {
2568 binding_mode: binding_mode
2574 // check that all of the arms in an or-pattern have exactly the
2575 // same set of bindings, with the same binding modes for each.
2576 fn check_consistent_bindings(&mut self, arm: &Arm) {
2577 if arm.pats.is_empty() {
2580 let map_0 = self.binding_mode_map(&*arm.pats[0]);
2581 for (i, p) in arm.pats.iter().enumerate() {
2582 let map_i = self.binding_mode_map(&**p);
2584 for (&key, &binding_0) in &map_0 {
2585 match map_i.get(&key) {
2589 ResolutionError::VariableNotBoundInPattern(key,
2592 Some(binding_i) => {
2593 if binding_0.binding_mode != binding_i.binding_mode {
2596 ResolutionError::VariableBoundWithDifferentMode(key,
2604 for (&key, &binding) in &map_i {
2605 if !map_0.contains_key(&key) {
2608 ResolutionError::VariableNotBoundInParentPattern(key,
2615 fn resolve_arm(&mut self, arm: &Arm) {
2616 self.value_ribs.push(Rib::new(NormalRibKind));
2618 let mut bindings_list = HashMap::new();
2619 for pattern in &arm.pats {
2620 self.resolve_pattern(&**pattern, RefutableMode, &mut bindings_list);
2623 // This has to happen *after* we determine which
2624 // pat_idents are variants
2625 self.check_consistent_bindings(arm);
2627 walk_list!(self, visit_expr, &arm.guard);
2628 self.visit_expr(&*arm.body);
2631 self.value_ribs.pop();
2635 fn resolve_block(&mut self, block: &Block) {
2636 debug!("(resolving block) entering block");
2637 self.value_ribs.push(Rib::new(NormalRibKind));
2639 // Move down in the graph, if there's an anonymous module rooted here.
2640 let orig_module = self.current_module.clone();
2641 match orig_module.anonymous_children.borrow().get(&block.id) {
2642 None => { /* Nothing to do. */ }
2643 Some(anonymous_module) => {
2644 debug!("(resolving block) found anonymous module, moving \
2646 self.current_module = anonymous_module.clone();
2650 // Check for imports appearing after non-item statements.
2651 let mut found_non_item = false;
2652 for statement in &block.stmts {
2653 if let hir::StmtDecl(ref declaration, _) = statement.node {
2654 if let hir::DeclItem(ref i) = declaration.node {
2656 ItemExternCrate(_) | ItemUse(_) if found_non_item => {
2657 span_err!(self.session, i.span, E0154,
2658 "imports are not allowed after non-item statements");
2663 found_non_item = true
2666 found_non_item = true;
2670 // Descend into the block.
2671 visit::walk_block(self, block);
2675 self.current_module = orig_module;
2676 self.value_ribs.pop();
2678 debug!("(resolving block) leaving block");
2681 fn resolve_type(&mut self, ty: &Ty) {
2683 TyPath(ref maybe_qself, ref path) => {
2685 match self.resolve_possibly_assoc_item(ty.id,
2686 maybe_qself.as_ref(),
2690 // `<T>::a::b::c` is resolved by typeck alone.
2691 TypecheckRequired => {
2692 // Resolve embedded types.
2693 visit::walk_ty(self, ty);
2696 ResolveAttempt(resolution) => resolution,
2699 // This is a path in the type namespace. Walk through scopes
2703 // Write the result into the def map.
2704 debug!("(resolving type) writing resolution for `{}` \
2706 path_names_to_string(path, 0),
2708 self.record_def(ty.id, def);
2711 // Keep reporting some errors even if they're ignored above.
2712 self.resolve_path(ty.id, path, 0, TypeNS, true);
2714 let kind = if maybe_qself.is_some() {
2720 let self_type_name = special_idents::type_self.name;
2721 let is_invalid_self_type_name =
2722 path.segments.len() > 0 &&
2723 maybe_qself.is_none() &&
2724 path.segments[0].identifier.name == self_type_name;
2725 if is_invalid_self_type_name {
2728 ResolutionError::SelfUsedOutsideImplOrTrait);
2732 ResolutionError::UseOfUndeclared(
2734 &*path_names_to_string(path,
2743 // Resolve embedded types.
2744 visit::walk_ty(self, ty);
2747 fn resolve_pattern(&mut self,
2749 mode: PatternBindingMode,
2750 // Maps idents to the node ID for the (outermost)
2751 // pattern that binds them
2752 bindings_list: &mut HashMap<Name, NodeId>) {
2753 let pat_id = pattern.id;
2754 walk_pat(pattern, |pattern| {
2755 match pattern.node {
2756 PatIdent(binding_mode, ref path1, ref at_rhs) => {
2757 // The meaning of PatIdent with no type parameters
2758 // depends on whether an enum variant or unit-like struct
2759 // with that name is in scope. The probing lookup has to
2760 // be careful not to emit spurious errors. Only matching
2761 // patterns (match) can match nullary variants or
2762 // unit-like structs. For binding patterns (let
2763 // and the LHS of @-patterns), matching such a value is
2764 // simply disallowed (since it's rarely what you want).
2765 let const_ok = mode == RefutableMode && at_rhs.is_none();
2767 let ident = path1.node;
2768 let renamed = mtwt::resolve(ident);
2770 match self.resolve_bare_identifier_pattern(ident.name, pattern.span) {
2771 FoundStructOrEnumVariant(def, lp) if const_ok => {
2772 debug!("(resolving pattern) resolving `{}` to \
2773 struct or enum variant",
2776 self.enforce_default_binding_mode(
2780 self.record_def(pattern.id, PathResolution {
2786 FoundStructOrEnumVariant(..) => {
2790 ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(
2794 FoundConst(def, lp) if const_ok => {
2795 debug!("(resolving pattern) resolving `{}` to \
2799 self.enforce_default_binding_mode(
2803 self.record_def(pattern.id, PathResolution {
2813 ResolutionError::OnlyIrrefutablePatternsAllowedHere
2816 BareIdentifierPatternUnresolved => {
2817 debug!("(resolving pattern) binding `{}`",
2820 let def = DefLocal(pattern.id);
2822 // Record the definition so that later passes
2823 // will be able to distinguish variants from
2824 // locals in patterns.
2826 self.record_def(pattern.id, PathResolution {
2828 last_private: LastMod(AllPublic),
2832 // Add the binding to the local ribs, if it
2833 // doesn't already exist in the bindings list. (We
2834 // must not add it if it's in the bindings list
2835 // because that breaks the assumptions later
2836 // passes make about or-patterns.)
2837 if !bindings_list.contains_key(&renamed) {
2838 let this = &mut *self;
2839 let last_rib = this.value_ribs.last_mut().unwrap();
2840 last_rib.bindings.insert(renamed, DlDef(def));
2841 bindings_list.insert(renamed, pat_id);
2842 } else if mode == ArgumentIrrefutableMode &&
2843 bindings_list.contains_key(&renamed) {
2844 // Forbid duplicate bindings in the same
2849 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2850 &ident.name.as_str())
2852 } else if bindings_list.get(&renamed) ==
2854 // Then this is a duplicate variable in the
2855 // same disjunction, which is an error.
2859 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2860 &ident.name.as_str())
2863 // Else, not bound in the same pattern: do
2869 PatEnum(ref path, _) => {
2870 // This must be an enum variant, struct or const.
2872 match self.resolve_possibly_assoc_item(pat_id, None,
2875 // The below shouldn't happen because all
2876 // qualified paths should be in PatQPath.
2877 TypecheckRequired =>
2878 self.session.span_bug(
2880 "resolve_possibly_assoc_item claimed
2881 that a path in PatEnum requires typecheck
2882 to resolve, but qualified paths should be
2884 ResolveAttempt(resolution) => resolution,
2886 if let Some(path_res) = resolution {
2887 match path_res.base_def {
2888 DefVariant(..) | DefStruct(..) | DefConst(..) => {
2889 self.record_def(pattern.id, path_res);
2892 resolve_error(&self,
2894 ResolutionError::StaticVariableReference);
2897 // If anything ends up here entirely resolved,
2898 // it's an error. If anything ends up here
2899 // partially resolved, that's OK, because it may
2900 // be a `T::CONST` that typeck will resolve.
2901 if path_res.depth == 0 {
2905 ResolutionError::NotAnEnumVariantStructOrConst(
2914 let const_name = path.segments.last().unwrap()
2916 let traits = self.get_traits_containing_item(const_name);
2917 self.trait_map.insert(pattern.id, traits);
2918 self.record_def(pattern.id, path_res);
2926 ResolutionError::UnresolvedEnumVariantStructOrConst(
2927 &path.segments.last().unwrap().identifier.name.as_str())
2930 visit::walk_path(self, path);
2933 PatQPath(ref qself, ref path) => {
2934 // Associated constants only.
2936 match self.resolve_possibly_assoc_item(pat_id, Some(qself),
2939 TypecheckRequired => {
2940 // All `<T>::CONST` should end up here, and will
2941 // require use of the trait map to resolve
2942 // during typechecking.
2943 let const_name = path.segments.last().unwrap()
2945 let traits = self.get_traits_containing_item(const_name);
2946 self.trait_map.insert(pattern.id, traits);
2947 visit::walk_pat(self, pattern);
2950 ResolveAttempt(resolution) => resolution,
2952 if let Some(path_res) = resolution {
2953 match path_res.base_def {
2954 // All `<T as Trait>::CONST` should end up here, and
2955 // have the trait already selected.
2956 DefAssociatedConst(..) => {
2957 self.record_def(pattern.id, path_res);
2963 ResolutionError::NotAnAssociatedConst(
2964 &path.segments.last().unwrap().identifier.name.as_str()
2973 ResolutionError::UnresolvedAssociatedConst(
2974 &path.segments.last().unwrap().identifier.name.as_str()
2978 visit::walk_pat(self, pattern);
2981 PatStruct(ref path, _, _) => {
2982 match self.resolve_path(pat_id, path, 0, TypeNS, false) {
2983 Some(definition) => {
2984 self.record_def(pattern.id, definition);
2987 debug!("(resolving pattern) didn't find struct \
2988 def: {:?}", result);
2992 ResolutionError::DoesNotNameAStruct(
2993 &*path_names_to_string(path, 0))
2997 visit::walk_path(self, path);
3000 PatLit(_) | PatRange(..) => {
3001 visit::walk_pat(self, pattern);
3012 fn resolve_bare_identifier_pattern(&mut self, name: Name, span: Span)
3013 -> BareIdentifierPatternResolution {
3014 let module = self.current_module.clone();
3015 match self.resolve_item_in_lexical_scope(module,
3018 Success((target, _)) => {
3019 debug!("(resolve bare identifier pattern) succeeded in \
3020 finding {} at {:?}",
3022 target.bindings.value_def.borrow());
3023 match *target.bindings.value_def.borrow() {
3025 panic!("resolved name in the value namespace to a \
3026 set of name bindings with no def?!");
3029 // For the two success cases, this lookup can be
3030 // considered as not having a private component because
3031 // the lookup happened only within the current module.
3033 def @ DefVariant(..) | def @ DefStruct(..) => {
3034 return FoundStructOrEnumVariant(def, LastMod(AllPublic));
3036 def @ DefConst(..) | def @ DefAssociatedConst(..) => {
3037 return FoundConst(def, LastMod(AllPublic));
3042 ResolutionError::StaticVariableReference);
3043 return BareIdentifierPatternUnresolved;
3046 return BareIdentifierPatternUnresolved;
3054 panic!("unexpected indeterminate result");
3058 Some((span, msg)) => {
3059 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3064 debug!("(resolve bare identifier pattern) failed to find {}",
3066 return BareIdentifierPatternUnresolved;
3071 /// Handles paths that may refer to associated items
3072 fn resolve_possibly_assoc_item(&mut self,
3074 maybe_qself: Option<&hir::QSelf>,
3076 namespace: Namespace,
3078 -> AssocItemResolveResult
3080 let max_assoc_types;
3084 if qself.position == 0 {
3085 return TypecheckRequired;
3087 max_assoc_types = path.segments.len() - qself.position;
3088 // Make sure the trait is valid.
3089 let _ = self.resolve_trait_reference(id, path, max_assoc_types);
3092 max_assoc_types = path.segments.len();
3096 let mut resolution = self.with_no_errors(|this| {
3097 this.resolve_path(id, path, 0, namespace, check_ribs)
3099 for depth in 1..max_assoc_types {
3100 if resolution.is_some() {
3103 self.with_no_errors(|this| {
3104 resolution = this.resolve_path(id, path, depth,
3108 if let Some(DefMod(_)) = resolution.map(|r| r.base_def) {
3109 // A module is not a valid type or value.
3112 ResolveAttempt(resolution)
3115 /// If `check_ribs` is true, checks the local definitions first; i.e.
3116 /// doesn't skip straight to the containing module.
3117 /// Skips `path_depth` trailing segments, which is also reflected in the
3118 /// returned value. See `middle::def::PathResolution` for more info.
3119 pub fn resolve_path(&mut self,
3123 namespace: Namespace,
3124 check_ribs: bool) -> Option<PathResolution> {
3125 let span = path.span;
3126 let segments = &path.segments[..path.segments.len()-path_depth];
3128 let mk_res = |(def, lp)| PathResolution::new(def, lp, path_depth);
3131 let def = self.resolve_crate_relative_path(span, segments, namespace);
3132 return def.map(mk_res);
3135 // Try to find a path to an item in a module.
3136 let unqualified_def =
3137 self.resolve_identifier(segments.last().unwrap().identifier,
3142 if segments.len() <= 1 {
3143 return unqualified_def.map(mk_res);
3146 let def = self.resolve_module_relative_path(span, segments, namespace);
3147 match (def, unqualified_def) {
3148 (Some((ref d, _)), Some((ref ud, _))) if *d == *ud => {
3150 .add_lint(lint::builtin::UNUSED_QUALIFICATIONS,
3152 "unnecessary qualification".to_string());
3160 // Resolve a single identifier.
3161 fn resolve_identifier(&mut self,
3163 namespace: Namespace,
3166 -> Option<(Def, LastPrivate)> {
3167 // First, check to see whether the name is a primitive type.
3168 if namespace == TypeNS {
3169 if let Some(&prim_ty) = self.primitive_type_table
3171 .get(&identifier.name) {
3172 return Some((DefPrimTy(prim_ty), LastMod(AllPublic)));
3177 if let Some(def) = self.resolve_identifier_in_local_ribs(identifier,
3180 return Some((def, LastMod(AllPublic)));
3184 self.resolve_item_by_name_in_lexical_scope(identifier.name, namespace)
3187 // FIXME #4952: Merge me with resolve_name_in_module?
3188 fn resolve_definition_of_name_in_module(&mut self,
3189 containing_module: Rc<Module>,
3191 namespace: Namespace)
3193 // First, search children.
3194 build_reduced_graph::populate_module_if_necessary(self, &containing_module);
3196 match containing_module.children.borrow().get(&name) {
3197 Some(child_name_bindings) => {
3198 match child_name_bindings.def_for_namespace(namespace) {
3200 // Found it. Stop the search here.
3201 let p = child_name_bindings.defined_in_public_namespace(namespace);
3202 let lp = if p {LastMod(AllPublic)} else {
3203 LastMod(DependsOn(def.def_id()))
3205 return ChildNameDefinition(def, lp);
3213 // Next, search import resolutions.
3214 match containing_module.import_resolutions.borrow().get(&name) {
3215 Some(import_resolution) if import_resolution.is_public => {
3216 if let Some(target) = (*import_resolution).target_for_namespace(namespace) {
3217 match target.bindings.def_for_namespace(namespace) {
3220 let id = import_resolution.id(namespace);
3221 // track imports and extern crates as well
3222 self.used_imports.insert((id, namespace));
3223 self.record_import_use(id, name);
3224 match target.target_module.def_id.get() {
3225 Some(DefId{krate: kid, ..}) => {
3226 self.used_crates.insert(kid);
3230 return ImportNameDefinition(def, LastMod(AllPublic));
3233 // This can happen with external impls, due to
3234 // the imperfect way we read the metadata.
3239 Some(..) | None => {} // Continue.
3242 // Finally, search through external children.
3243 if namespace == TypeNS {
3244 if let Some(module) = containing_module.external_module_children.borrow()
3245 .get(&name).cloned() {
3246 if let Some(def_id) = module.def_id.get() {
3247 // track used crates
3248 self.used_crates.insert(def_id.krate);
3249 let lp = if module.is_public {LastMod(AllPublic)} else {
3250 LastMod(DependsOn(def_id))
3252 return ChildNameDefinition(DefMod(def_id), lp);
3257 return NoNameDefinition;
3260 // resolve a "module-relative" path, e.g. a::b::c
3261 fn resolve_module_relative_path(&mut self,
3263 segments: &[hir::PathSegment],
3264 namespace: Namespace)
3265 -> Option<(Def, LastPrivate)> {
3266 let module_path = segments.split_last().unwrap().1.iter()
3267 .map(|ps| ps.identifier.name)
3268 .collect::<Vec<_>>();
3270 let containing_module;
3272 let current_module = self.current_module.clone();
3273 match self.resolve_module_path(current_module,
3279 let (span, msg) = match err {
3280 Some((span, msg)) => (span, msg),
3282 let msg = format!("Use of undeclared type or module `{}`",
3283 names_to_string(&module_path));
3288 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3291 Indeterminate => panic!("indeterminate unexpected"),
3292 Success((resulting_module, resulting_last_private)) => {
3293 containing_module = resulting_module;
3294 last_private = resulting_last_private;
3298 let name = segments.last().unwrap().identifier.name;
3299 let def = match self.resolve_definition_of_name_in_module(containing_module.clone(),
3302 NoNameDefinition => {
3303 // We failed to resolve the name. Report an error.
3306 ChildNameDefinition(def, lp) | ImportNameDefinition(def, lp) => {
3307 (def, last_private.or(lp))
3310 if let Some(DefId{krate: kid, ..}) = containing_module.def_id.get() {
3311 self.used_crates.insert(kid);
3316 /// Invariant: This must be called only during main resolution, not during
3317 /// import resolution.
3318 fn resolve_crate_relative_path(&mut self,
3320 segments: &[hir::PathSegment],
3321 namespace: Namespace)
3322 -> Option<(Def, LastPrivate)> {
3323 let module_path = segments.split_last().unwrap().1.iter()
3324 .map(|ps| ps.identifier.name)
3325 .collect::<Vec<_>>();
3327 let root_module = self.graph_root.get_module();
3329 let containing_module;
3331 match self.resolve_module_path_from_root(root_module,
3336 LastMod(AllPublic)) {
3338 let (span, msg) = match err {
3339 Some((span, msg)) => (span, msg),
3341 let msg = format!("Use of undeclared module `::{}`",
3342 names_to_string(&module_path[..]));
3347 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
3352 panic!("indeterminate unexpected");
3355 Success((resulting_module, resulting_last_private)) => {
3356 containing_module = resulting_module;
3357 last_private = resulting_last_private;
3361 let name = segments.last().unwrap().identifier.name;
3362 match self.resolve_definition_of_name_in_module(containing_module,
3365 NoNameDefinition => {
3366 // We failed to resolve the name. Report an error.
3369 ChildNameDefinition(def, lp) | ImportNameDefinition(def, lp) => {
3370 return Some((def, last_private.or(lp)));
3375 fn resolve_identifier_in_local_ribs(&mut self,
3377 namespace: Namespace,
3380 // Check the local set of ribs.
3381 let search_result = match namespace {
3383 let renamed = mtwt::resolve(ident);
3384 self.search_ribs(&self.value_ribs, renamed, span)
3387 let name = ident.name;
3388 self.search_ribs(&self.type_ribs, name, span)
3392 match search_result {
3393 Some(DlDef(def)) => {
3394 debug!("(resolving path in local ribs) resolved `{}` to local: {:?}",
3399 Some(DlField) | Some(DlImpl(_)) | None => {
3405 fn resolve_item_by_name_in_lexical_scope(&mut self,
3407 namespace: Namespace)
3408 -> Option<(Def, LastPrivate)> {
3410 let module = self.current_module.clone();
3411 match self.resolve_item_in_lexical_scope(module,
3414 Success((target, _)) => {
3415 match (*target.bindings).def_for_namespace(namespace) {
3417 // This can happen if we were looking for a type and
3418 // found a module instead. Modules don't have defs.
3419 debug!("(resolving item path by identifier in lexical \
3420 scope) failed to resolve {} after success...",
3425 debug!("(resolving item path in lexical scope) \
3426 resolved `{}` to item",
3428 // This lookup is "all public" because it only searched
3429 // for one identifier in the current module (couldn't
3430 // have passed through reexports or anything like that.
3431 return Some((def, LastMod(AllPublic)));
3436 panic!("unexpected indeterminate result");
3439 debug!("(resolving item path by identifier in lexical scope) \
3440 failed to resolve {}", name);
3442 if let Some((span, msg)) = err {
3443 resolve_error(self, span, ResolutionError::FailedToResolve(&*msg))
3451 fn with_no_errors<T, F>(&mut self, f: F) -> T where
3452 F: FnOnce(&mut Resolver) -> T,
3454 self.emit_errors = false;
3456 self.emit_errors = true;
3460 fn find_fallback_in_self_type(&mut self, name: Name) -> FallbackSuggestion {
3461 fn extract_path_and_node_id(t: &Ty, allow: FallbackChecks)
3462 -> Option<(Path, NodeId, FallbackChecks)> {
3464 TyPath(None, ref path) => Some((path.clone(), t.id, allow)),
3465 TyPtr(ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, OnlyTraitAndStatics),
3466 TyRptr(_, ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, allow),
3467 // This doesn't handle the remaining `Ty` variants as they are not
3468 // that commonly the self_type, it might be interesting to provide
3469 // support for those in future.
3474 fn get_module(this: &mut Resolver, span: Span, name_path: &[ast::Name])
3475 -> Option<Rc<Module>> {
3476 let root = this.current_module.clone();
3477 let last_name = name_path.last().unwrap();
3479 if name_path.len() == 1 {
3480 match this.primitive_type_table.primitive_types.get(last_name) {
3483 match this.current_module.children.borrow().get(last_name) {
3484 Some(child) => child.get_module_if_available(),
3490 match this.resolve_module_path(root,
3495 Success((module, _)) => Some(module),
3501 fn is_static_method(this: &Resolver, did: DefId) -> bool {
3502 if let Some(node_id) = this.ast_map.as_local_node_id(did) {
3503 let sig = match this.ast_map.get(node_id) {
3504 hir_map::NodeTraitItem(trait_item) => match trait_item.node {
3505 hir::MethodTraitItem(ref sig, _) => sig,
3508 hir_map::NodeImplItem(impl_item) => match impl_item.node {
3509 hir::MethodImplItem(ref sig, _) => sig,
3514 sig.explicit_self.node == hir::SelfStatic
3516 csearch::is_static_method(&this.session.cstore, did)
3520 let (path, node_id, allowed) = match self.current_self_type {
3521 Some(ref ty) => match extract_path_and_node_id(ty, Everything) {
3523 None => return NoSuggestion,
3525 None => return NoSuggestion,
3528 if allowed == Everything {
3529 // Look for a field with the same name in the current self_type.
3530 match self.def_map.borrow().get(&node_id).map(|d| d.full_def()) {
3531 Some(DefTy(did, _)) |
3532 Some(DefStruct(did)) |
3533 Some(DefVariant(_, did, _)) => match self.structs.get(&did) {
3536 if fields.iter().any(|&field_name| name == field_name) {
3541 _ => {} // Self type didn't resolve properly
3545 let name_path = path.segments.iter().map(|seg| seg.identifier.name).collect::<Vec<_>>();
3547 // Look for a method in the current self type's impl module.
3548 if let Some(module) = get_module(self, path.span, &name_path) {
3549 if let Some(binding) = module.children.borrow().get(&name) {
3550 if let Some(DefMethod(did)) = binding.def_for_namespace(ValueNS) {
3551 if is_static_method(self, did) {
3552 return StaticMethod(path_names_to_string(&path, 0))
3554 if self.current_trait_ref.is_some() {
3556 } else if allowed == Everything {
3563 // Look for a method in the current trait.
3564 if let Some((trait_did, ref trait_ref)) = self.current_trait_ref {
3565 if let Some(&did) = self.trait_item_map.get(&(name, trait_did)) {
3566 if is_static_method(self, did) {
3567 return TraitMethod(path_names_to_string(&trait_ref.path, 0));
3577 fn find_best_match_for_name(&mut self, name: &str) -> Option<String> {
3578 let mut maybes: Vec<token::InternedString> = Vec::new();
3579 let mut values: Vec<usize> = Vec::new();
3581 for rib in self.value_ribs.iter().rev() {
3582 for (&k, _) in &rib.bindings {
3583 maybes.push(k.as_str());
3584 values.push(usize::MAX);
3588 let mut smallest = 0;
3589 for (i, other) in maybes.iter().enumerate() {
3590 values[i] = lev_distance(name, &other);
3592 if values[i] <= values[smallest] {
3597 // As a loose rule to avoid obviously incorrect suggestions, clamp the
3598 // maximum edit distance we will accept for a suggestion to one third of
3599 // the typo'd name's length.
3600 let max_distance = std::cmp::max(name.len(), 3) / 3;
3602 if !values.is_empty() &&
3603 values[smallest] <= max_distance &&
3604 name != &maybes[smallest][..] {
3606 Some(maybes[smallest].to_string())
3613 fn resolve_expr(&mut self, expr: &Expr) {
3614 // First, record candidate traits for this expression if it could
3615 // result in the invocation of a method call.
3617 self.record_candidate_traits_for_expr_if_necessary(expr);
3619 // Next, resolve the node.
3621 ExprPath(ref maybe_qself, ref path) => {
3623 match self.resolve_possibly_assoc_item(expr.id,
3624 maybe_qself.as_ref(),
3628 // `<T>::a::b::c` is resolved by typeck alone.
3629 TypecheckRequired => {
3630 let method_name = path.segments.last().unwrap().identifier.name;
3631 let traits = self.get_traits_containing_item(method_name);
3632 self.trait_map.insert(expr.id, traits);
3633 visit::walk_expr(self, expr);
3636 ResolveAttempt(resolution) => resolution,
3639 // This is a local path in the value namespace. Walk through
3640 // scopes looking for it.
3641 if let Some(path_res) = resolution {
3642 // Check if struct variant
3643 if let DefVariant(_, _, true) = path_res.base_def {
3644 let path_name = path_names_to_string(path, 0);
3648 ResolutionError::StructVariantUsedAsFunction(&*path_name));
3650 let msg = format!("did you mean to write: \
3651 `{} {{ /* fields */ }}`?",
3653 if self.emit_errors {
3654 self.session.fileline_help(expr.span, &msg);
3656 self.session.span_help(expr.span, &msg);
3659 // Write the result into the def map.
3660 debug!("(resolving expr) resolved `{}`",
3661 path_names_to_string(path, 0));
3663 // Partial resolutions will need the set of traits in scope,
3664 // so they can be completed during typeck.
3665 if path_res.depth != 0 {
3666 let method_name = path.segments.last().unwrap().identifier.name;
3667 let traits = self.get_traits_containing_item(method_name);
3668 self.trait_map.insert(expr.id, traits);
3671 self.record_def(expr.id, path_res);
3674 // Be helpful if the name refers to a struct
3675 // (The pattern matching def_tys where the id is in self.structs
3676 // matches on regular structs while excluding tuple- and enum-like
3677 // structs, which wouldn't result in this error.)
3678 let path_name = path_names_to_string(path, 0);
3679 let type_res = self.with_no_errors(|this| {
3680 this.resolve_path(expr.id, path, 0, TypeNS, false)
3682 match type_res.map(|r| r.base_def) {
3683 Some(DefTy(struct_id, _))
3684 if self.structs.contains_key(&struct_id) => {
3688 ResolutionError::StructVariantUsedAsFunction(
3692 let msg = format!("did you mean to write: \
3693 `{} {{ /* fields */ }}`?",
3695 if self.emit_errors {
3696 self.session.fileline_help(expr.span, &msg);
3698 self.session.span_help(expr.span, &msg);
3702 // Keep reporting some errors even if they're ignored above.
3703 self.resolve_path(expr.id, path, 0, ValueNS, true);
3705 let mut method_scope = false;
3706 self.value_ribs.iter().rev().all(|rib| {
3707 method_scope = match rib.kind {
3708 MethodRibKind => true,
3709 ItemRibKind | ConstantItemRibKind => false,
3710 _ => return true, // Keep advancing
3712 false // Stop advancing
3715 if method_scope && special_names::self_.as_str() == &path_name[..] {
3719 ResolutionError::SelfNotAvailableInStaticMethod
3722 let last_name = path.segments.last().unwrap().identifier.name;
3723 let mut msg = match self.find_fallback_in_self_type(last_name) {
3725 // limit search to 5 to reduce the number
3726 // of stupid suggestions
3727 self.find_best_match_for_name(&path_name)
3728 .map_or("".to_string(),
3729 |x| format!("`{}`", x))
3731 Field => format!("`self.{}`", path_name),
3734 format!("to call `self.{}`", path_name),
3735 TraitMethod(path_str) |
3736 StaticMethod(path_str) =>
3737 format!("to call `{}::{}`", path_str, path_name)
3740 if !msg.is_empty() {
3741 msg = format!(". Did you mean {}?", msg)
3746 ResolutionError::UnresolvedName(&*path_name,
3753 visit::walk_expr(self, expr);
3756 ExprStruct(ref path, _, _) => {
3757 // Resolve the path to the structure it goes to. We don't
3758 // check to ensure that the path is actually a structure; that
3759 // is checked later during typeck.
3760 match self.resolve_path(expr.id, path, 0, TypeNS, false) {
3761 Some(definition) => self.record_def(expr.id, definition),
3763 debug!("(resolving expression) didn't find struct def",);
3767 ResolutionError::DoesNotNameAStruct(
3768 &*path_names_to_string(path, 0))
3773 visit::walk_expr(self, expr);
3776 ExprLoop(_, Some(label)) | ExprWhile(_, _, Some(label)) => {
3777 self.with_label_rib(|this| {
3778 let def_like = DlDef(DefLabel(expr.id));
3781 let rib = this.label_ribs.last_mut().unwrap();
3782 let renamed = mtwt::resolve(label);
3783 rib.bindings.insert(renamed, def_like);
3786 visit::walk_expr(this, expr);
3790 ExprBreak(Some(label)) | ExprAgain(Some(label)) => {
3791 let renamed = mtwt::resolve(label.node);
3792 match self.search_label(renamed) {
3796 ResolutionError::UndeclaredLabel(&label.node.name.as_str()))
3798 Some(DlDef(def @ DefLabel(_))) => {
3799 // Since this def is a label, it is never read.
3800 self.record_def(expr.id, PathResolution {
3802 last_private: LastMod(AllPublic),
3807 self.session.span_bug(expr.span,
3808 "label wasn't mapped to a \
3815 visit::walk_expr(self, expr);
3820 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3822 ExprField(_, name) => {
3823 // FIXME(#6890): Even though you can't treat a method like a
3824 // field, we need to add any trait methods we find that match
3825 // the field name so that we can do some nice error reporting
3826 // later on in typeck.
3827 let traits = self.get_traits_containing_item(name.node);
3828 self.trait_map.insert(expr.id, traits);
3830 ExprMethodCall(name, _, _) => {
3831 debug!("(recording candidate traits for expr) recording \
3834 let traits = self.get_traits_containing_item(name.node);
3835 self.trait_map.insert(expr.id, traits);
3843 fn get_traits_containing_item(&mut self, name: Name) -> Vec<DefId> {
3844 debug!("(getting traits containing item) looking for '{}'",
3847 fn add_trait_info(found_traits: &mut Vec<DefId>,
3848 trait_def_id: DefId,
3850 debug!("(adding trait info) found trait {:?} for method '{}'",
3853 found_traits.push(trait_def_id);
3856 let mut found_traits = Vec::new();
3857 let mut search_module = self.current_module.clone();
3859 // Look for the current trait.
3860 match self.current_trait_ref {
3861 Some((trait_def_id, _)) => {
3862 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3863 add_trait_info(&mut found_traits, trait_def_id, name);
3866 None => {} // Nothing to do.
3869 // Look for trait children.
3870 build_reduced_graph::populate_module_if_necessary(self, &search_module);
3873 for (_, child_names) in search_module.children.borrow().iter() {
3874 let def = match child_names.def_for_namespace(TypeNS) {
3878 let trait_def_id = match def {
3879 DefTrait(trait_def_id) => trait_def_id,
3882 if self.trait_item_map.contains_key(&(name, trait_def_id)) {
3883 add_trait_info(&mut found_traits, trait_def_id, name);
3888 // Look for imports.
3889 for (_, import) in search_module.import_resolutions.borrow().iter() {
3890 let target = match import.target_for_namespace(TypeNS) {
3892 Some(target) => target,
3894 let did = match target.bindings.def_for_namespace(TypeNS) {
3895 Some(DefTrait(trait_def_id)) => trait_def_id,
3896 Some(..) | None => continue,
3898 if self.trait_item_map.contains_key(&(name, did)) {
3899 add_trait_info(&mut found_traits, did, name);
3900 let id = import.type_id;
3901 self.used_imports.insert((id, TypeNS));
3902 let trait_name = self.get_trait_name(did);
3903 self.record_import_use(id, trait_name);
3904 if let Some(DefId{krate: kid, ..}) = target.target_module.def_id.get() {
3905 self.used_crates.insert(kid);
3910 match search_module.parent_link.clone() {
3911 NoParentLink | ModuleParentLink(..) => break,
3912 BlockParentLink(parent_module, _) => {
3913 search_module = parent_module.upgrade().unwrap();
3921 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
3922 debug!("(recording def) recording {:?} for {}", resolution, node_id);
3923 assert!(match resolution.last_private {LastImport{..} => false, _ => true},
3924 "Import should only be used for `use` directives");
3926 if let Some(prev_res) = self.def_map.borrow_mut().insert(node_id, resolution) {
3927 let span = self.ast_map.opt_span(node_id).unwrap_or(codemap::DUMMY_SP);
3928 self.session.span_bug(span, &format!("path resolved multiple times \
3929 ({:?} before, {:?} now)",
3930 prev_res, resolution));
3934 fn enforce_default_binding_mode(&mut self,
3936 pat_binding_mode: BindingMode,
3938 match pat_binding_mode {
3939 BindByValue(_) => {}
3943 ResolutionError::CannotUseRefBindingModeWith(descr));
3951 // Diagnostics are not particularly efficient, because they're rarely
3955 #[allow(dead_code)] // useful for debugging
3956 fn dump_module(&mut self, module_: Rc<Module>) {
3957 debug!("Dump of module `{}`:", module_to_string(&*module_));
3959 debug!("Children:");
3960 build_reduced_graph::populate_module_if_necessary(self, &module_);
3961 for (&name, _) in module_.children.borrow().iter() {
3962 debug!("* {}", name);
3965 debug!("Import resolutions:");
3966 let import_resolutions = module_.import_resolutions.borrow();
3967 for (&name, import_resolution) in import_resolutions.iter() {
3969 match import_resolution.target_for_namespace(ValueNS) {
3970 None => { value_repr = "".to_string(); }
3972 value_repr = " value:?".to_string();
3978 match import_resolution.target_for_namespace(TypeNS) {
3979 None => { type_repr = "".to_string(); }
3981 type_repr = " type:?".to_string();
3986 debug!("* {}:{}{}", name, value_repr, type_repr);
3992 fn names_to_string(names: &[Name]) -> String {
3993 let mut first = true;
3994 let mut result = String::new();
3999 result.push_str("::")
4001 result.push_str(&name.as_str());
4006 fn path_names_to_string(path: &Path, depth: usize) -> String {
4007 let names: Vec<ast::Name> = path.segments[..path.segments.len()-depth]
4009 .map(|seg| seg.identifier.name)
4011 names_to_string(&names[..])
4014 /// A somewhat inefficient routine to obtain the name of a module.
4015 fn module_to_string(module: &Module) -> String {
4016 let mut names = Vec::new();
4018 fn collect_mod(names: &mut Vec<ast::Name>, module: &Module) {
4019 match module.parent_link {
4021 ModuleParentLink(ref module, name) => {
4023 collect_mod(names, &*module.upgrade().unwrap());
4025 BlockParentLink(ref module, _) => {
4026 // danger, shouldn't be ident?
4027 names.push(special_idents::opaque.name);
4028 collect_mod(names, &*module.upgrade().unwrap());
4032 collect_mod(&mut names, module);
4034 if names.is_empty() {
4035 return "???".to_string();
4037 names_to_string(&names.into_iter().rev().collect::<Vec<ast::Name>>())
4041 pub struct CrateMap {
4042 pub def_map: DefMap,
4043 pub freevars: RefCell<FreevarMap>,
4044 pub export_map: ExportMap,
4045 pub trait_map: TraitMap,
4046 pub external_exports: ExternalExports,
4047 pub glob_map: Option<GlobMap>
4050 #[derive(PartialEq,Copy, Clone)]
4051 pub enum MakeGlobMap {
4056 /// Entry point to crate resolution.
4057 pub fn resolve_crate<'a, 'tcx>(session: &'a Session,
4058 ast_map: &'a hir_map::Map<'tcx>,
4059 make_glob_map: MakeGlobMap)
4061 let krate = ast_map.krate();
4062 let mut resolver = create_resolver(session, ast_map, krate, make_glob_map, None);
4064 resolver.resolve_crate(krate);
4065 session.abort_if_errors();
4067 check_unused::check_crate(&mut resolver, krate);
4070 def_map: resolver.def_map,
4071 freevars: resolver.freevars,
4072 export_map: resolver.export_map,
4073 trait_map: resolver.trait_map,
4074 external_exports: resolver.external_exports,
4075 glob_map: if resolver.make_glob_map {
4076 Some(resolver.glob_map)
4083 /// Builds a name resolution walker to be used within this module,
4084 /// or used externally, with an optional callback function.
4086 /// The callback takes a &mut bool which allows callbacks to end a
4087 /// walk when set to true, passing through the rest of the walk, while
4088 /// preserving the ribs + current module. This allows resolve_path
4089 /// calls to be made with the correct scope info. The node in the
4090 /// callback corresponds to the current node in the walk.
4091 pub fn create_resolver<'a, 'tcx>(session: &'a Session,
4092 ast_map: &'a hir_map::Map<'tcx>,
4094 make_glob_map: MakeGlobMap,
4095 callback: Option<Box<Fn(hir_map::Node, &mut bool) -> bool>>)
4096 -> Resolver<'a, 'tcx> {
4097 let mut resolver = Resolver::new(session, ast_map, krate.span, make_glob_map);
4099 resolver.callback = callback;
4101 build_reduced_graph::build_reduced_graph(&mut resolver, krate);
4102 session.abort_if_errors();
4104 resolve_imports::resolve_imports(&mut resolver);
4105 session.abort_if_errors();
4107 record_exports::record(&mut resolver);
4108 session.abort_if_errors();
4113 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }