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 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
12 html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
13 html_root_url = "https://doc.rust-lang.org/nightly/")]
16 #![feature(rustc_diagnostic_macros)]
22 extern crate syntax_pos;
23 extern crate rustc_errors as errors;
27 extern crate rustc_data_structures;
29 use self::Namespace::*;
30 use self::TypeParameters::*;
33 use rustc::hir::map::{Definitions, DefCollector};
34 use rustc::hir::{self, PrimTy, TyBool, TyChar, TyFloat, TyInt, TyUint, TyStr};
35 use rustc::middle::cstore::{CrateStore, CrateLoader};
36 use rustc::session::Session;
38 use rustc::hir::def::*;
39 use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, DefId};
41 use rustc::hir::{Freevar, FreevarMap, TraitCandidate, TraitMap, GlobMap};
42 use rustc::util::nodemap::{NodeMap, NodeSet, FxHashMap, FxHashSet, DefIdMap};
44 use syntax::codemap::{dummy_spanned, respan};
45 use syntax::ext::hygiene::{Mark, MarkKind, SyntaxContext};
46 use syntax::ast::{self, Name, NodeId, Ident, SpannedIdent, FloatTy, IntTy, UintTy};
47 use syntax::ext::base::SyntaxExtension;
48 use syntax::ext::base::Determinacy::{self, Determined, Undetermined};
49 use syntax::ext::base::MacroKind;
50 use syntax::symbol::{Symbol, keywords};
51 use syntax::util::lev_distance::find_best_match_for_name;
53 use syntax::visit::{self, FnKind, Visitor};
55 use syntax::ast::{Arm, BindingMode, Block, Crate, Expr, ExprKind};
56 use syntax::ast::{FnDecl, ForeignItem, ForeignItemKind, GenericParam, Generics};
57 use syntax::ast::{Item, ItemKind, ImplItem, ImplItemKind};
58 use syntax::ast::{Label, Local, Mutability, Pat, PatKind, Path};
59 use syntax::ast::{QSelf, TraitItemKind, TraitRef, Ty, TyKind};
60 use syntax::feature_gate::{feature_err, emit_feature_err, GateIssue};
61 use syntax::parse::token;
64 use syntax_pos::{Span, DUMMY_SP, MultiSpan};
65 use errors::{DiagnosticBuilder, DiagnosticId};
67 use std::cell::{Cell, RefCell};
69 use std::collections::BTreeSet;
72 use std::mem::replace;
73 use rustc_data_structures::sync::Lrc;
75 use resolve_imports::{ImportDirective, ImportDirectiveSubclass, NameResolution, ImportResolver};
76 use macros::{InvocationData, LegacyBinding, LegacyScope, MacroBinding};
78 // NB: This module needs to be declared first so diagnostics are
79 // registered before they are used.
84 mod build_reduced_graph;
87 /// A free importable items suggested in case of resolution failure.
88 struct ImportSuggestion {
92 /// A field or associated item from self type suggested in case of resolution failure.
93 enum AssocSuggestion {
100 struct BindingError {
102 origin: BTreeSet<Span>,
103 target: BTreeSet<Span>,
106 impl PartialOrd for BindingError {
107 fn partial_cmp(&self, other: &BindingError) -> Option<cmp::Ordering> {
108 Some(self.cmp(other))
112 impl PartialEq for BindingError {
113 fn eq(&self, other: &BindingError) -> bool {
114 self.name == other.name
118 impl Ord for BindingError {
119 fn cmp(&self, other: &BindingError) -> cmp::Ordering {
120 self.name.cmp(&other.name)
124 enum ResolutionError<'a> {
125 /// error E0401: can't use type parameters from outer function
126 TypeParametersFromOuterFunction,
127 /// error E0403: the name is already used for a type parameter in this type parameter list
128 NameAlreadyUsedInTypeParameterList(Name, &'a Span),
129 /// error E0407: method is not a member of trait
130 MethodNotMemberOfTrait(Name, &'a str),
131 /// error E0437: type is not a member of trait
132 TypeNotMemberOfTrait(Name, &'a str),
133 /// error E0438: const is not a member of trait
134 ConstNotMemberOfTrait(Name, &'a str),
135 /// error E0408: variable `{}` is not bound in all patterns
136 VariableNotBoundInPattern(&'a BindingError),
137 /// error E0409: variable `{}` is bound in inconsistent ways within the same match arm
138 VariableBoundWithDifferentMode(Name, Span),
139 /// error E0415: identifier is bound more than once in this parameter list
140 IdentifierBoundMoreThanOnceInParameterList(&'a str),
141 /// error E0416: identifier is bound more than once in the same pattern
142 IdentifierBoundMoreThanOnceInSamePattern(&'a str),
143 /// error E0426: use of undeclared label
144 UndeclaredLabel(&'a str, Option<Name>),
145 /// error E0429: `self` imports are only allowed within a { } list
146 SelfImportsOnlyAllowedWithin,
147 /// error E0430: `self` import can only appear once in the list
148 SelfImportCanOnlyAppearOnceInTheList,
149 /// error E0431: `self` import can only appear in an import list with a non-empty prefix
150 SelfImportOnlyInImportListWithNonEmptyPrefix,
151 /// error E0432: unresolved import
152 UnresolvedImport(Option<(Span, &'a str, &'a str)>),
153 /// error E0433: failed to resolve
154 FailedToResolve(&'a str),
155 /// error E0434: can't capture dynamic environment in a fn item
156 CannotCaptureDynamicEnvironmentInFnItem,
157 /// error E0435: attempt to use a non-constant value in a constant
158 AttemptToUseNonConstantValueInConstant,
159 /// error E0530: X bindings cannot shadow Ys
160 BindingShadowsSomethingUnacceptable(&'a str, Name, &'a NameBinding<'a>),
161 /// error E0128: type parameters with a default cannot use forward declared identifiers
162 ForwardDeclaredTyParam,
165 fn resolve_error<'sess, 'a>(resolver: &'sess Resolver,
167 resolution_error: ResolutionError<'a>) {
168 resolve_struct_error(resolver, span, resolution_error).emit();
171 fn resolve_struct_error<'sess, 'a>(resolver: &'sess Resolver,
173 resolution_error: ResolutionError<'a>)
174 -> DiagnosticBuilder<'sess> {
175 match resolution_error {
176 ResolutionError::TypeParametersFromOuterFunction => {
177 let mut err = struct_span_err!(resolver.session,
180 "can't use type parameters from outer function; \
181 try using a local type parameter instead");
182 err.span_label(span, "use of type variable from outer function");
185 ResolutionError::NameAlreadyUsedInTypeParameterList(name, first_use_span) => {
186 let mut err = struct_span_err!(resolver.session,
189 "the name `{}` is already used for a type parameter \
190 in this type parameter list",
192 err.span_label(span, "already used");
193 err.span_label(first_use_span.clone(), format!("first use of `{}`", name));
196 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
197 let mut err = struct_span_err!(resolver.session,
200 "method `{}` is not a member of trait `{}`",
203 err.span_label(span, format!("not a member of trait `{}`", trait_));
206 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
207 let mut err = struct_span_err!(resolver.session,
210 "type `{}` is not a member of trait `{}`",
213 err.span_label(span, format!("not a member of trait `{}`", trait_));
216 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
217 let mut err = struct_span_err!(resolver.session,
220 "const `{}` is not a member of trait `{}`",
223 err.span_label(span, format!("not a member of trait `{}`", trait_));
226 ResolutionError::VariableNotBoundInPattern(binding_error) => {
227 let target_sp = binding_error.target.iter().map(|x| *x).collect::<Vec<_>>();
228 let msp = MultiSpan::from_spans(target_sp.clone());
229 let msg = format!("variable `{}` is not bound in all patterns", binding_error.name);
230 let mut err = resolver.session.struct_span_err_with_code(
233 DiagnosticId::Error("E0408".into()),
235 for sp in target_sp {
236 err.span_label(sp, format!("pattern doesn't bind `{}`", binding_error.name));
238 let origin_sp = binding_error.origin.iter().map(|x| *x).collect::<Vec<_>>();
239 for sp in origin_sp {
240 err.span_label(sp, "variable not in all patterns");
244 ResolutionError::VariableBoundWithDifferentMode(variable_name,
245 first_binding_span) => {
246 let mut err = struct_span_err!(resolver.session,
249 "variable `{}` is bound in inconsistent \
250 ways within the same match arm",
252 err.span_label(span, "bound in different ways");
253 err.span_label(first_binding_span, "first binding");
256 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
257 let mut err = struct_span_err!(resolver.session,
260 "identifier `{}` is bound more than once in this parameter list",
262 err.span_label(span, "used as parameter more than once");
265 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
266 let mut err = struct_span_err!(resolver.session,
269 "identifier `{}` is bound more than once in the same pattern",
271 err.span_label(span, "used in a pattern more than once");
274 ResolutionError::UndeclaredLabel(name, lev_candidate) => {
275 let mut err = struct_span_err!(resolver.session,
278 "use of undeclared label `{}`",
280 if let Some(lev_candidate) = lev_candidate {
281 err.span_label(span, format!("did you mean `{}`?", lev_candidate));
283 err.span_label(span, format!("undeclared label `{}`", name));
287 ResolutionError::SelfImportsOnlyAllowedWithin => {
288 struct_span_err!(resolver.session,
292 "`self` imports are only allowed within a { } list")
294 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
295 let mut err = struct_span_err!(resolver.session, span, E0430,
296 "`self` import can only appear once in an import list");
297 err.span_label(span, "can only appear once in an import list");
300 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
301 let mut err = struct_span_err!(resolver.session, span, E0431,
302 "`self` import can only appear in an import list with \
303 a non-empty prefix");
304 err.span_label(span, "can only appear in an import list with a non-empty prefix");
307 ResolutionError::UnresolvedImport(name) => {
308 let (span, msg) = match name {
309 Some((sp, n, _)) => (sp, format!("unresolved import `{}`", n)),
310 None => (span, "unresolved import".to_owned()),
312 let mut err = struct_span_err!(resolver.session, span, E0432, "{}", msg);
313 if let Some((_, _, p)) = name {
314 err.span_label(span, p);
318 ResolutionError::FailedToResolve(msg) => {
319 let mut err = struct_span_err!(resolver.session, span, E0433,
320 "failed to resolve. {}", msg);
321 err.span_label(span, msg);
324 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
325 let mut err = struct_span_err!(resolver.session,
329 "can't capture dynamic environment in a fn item");
330 err.help("use the `|| { ... }` closure form instead");
333 ResolutionError::AttemptToUseNonConstantValueInConstant => {
334 let mut err = struct_span_err!(resolver.session, span, E0435,
335 "attempt to use a non-constant value in a constant");
336 err.span_label(span, "non-constant value");
339 ResolutionError::BindingShadowsSomethingUnacceptable(what_binding, name, binding) => {
340 let shadows_what = PathResolution::new(binding.def()).kind_name();
341 let mut err = struct_span_err!(resolver.session,
344 "{}s cannot shadow {}s", what_binding, shadows_what);
345 err.span_label(span, format!("cannot be named the same as a {}", shadows_what));
346 let participle = if binding.is_import() { "imported" } else { "defined" };
347 let msg = format!("a {} `{}` is {} here", shadows_what, name, participle);
348 err.span_label(binding.span, msg);
351 ResolutionError::ForwardDeclaredTyParam => {
352 let mut err = struct_span_err!(resolver.session, span, E0128,
353 "type parameters with a default cannot use \
354 forward declared identifiers");
355 err.span_label(span, format!("defaulted type parameters cannot be forward declared"));
361 #[derive(Copy, Clone, Debug)]
364 binding_mode: BindingMode,
367 // Map from the name in a pattern to its binding mode.
368 type BindingMap = FxHashMap<Ident, BindingInfo>;
370 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
381 fn descr(self) -> &'static str {
383 PatternSource::Match => "match binding",
384 PatternSource::IfLet => "if let binding",
385 PatternSource::WhileLet => "while let binding",
386 PatternSource::Let => "let binding",
387 PatternSource::For => "for binding",
388 PatternSource::FnParam => "function parameter",
393 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
394 enum AliasPossibility {
399 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
400 enum PathSource<'a> {
401 // Type paths `Path`.
403 // Trait paths in bounds or impls.
404 Trait(AliasPossibility),
405 // Expression paths `path`, with optional parent context.
406 Expr(Option<&'a Expr>),
407 // Paths in path patterns `Path`.
409 // Paths in struct expressions and patterns `Path { .. }`.
411 // Paths in tuple struct patterns `Path(..)`.
413 // `m::A::B` in `<T as m::A>::B::C`.
414 TraitItem(Namespace),
415 // Path in `pub(path)`
417 // Path in `use a::b::{...};`
421 impl<'a> PathSource<'a> {
422 fn namespace(self) -> Namespace {
424 PathSource::Type | PathSource::Trait(_) | PathSource::Struct |
425 PathSource::Visibility | PathSource::ImportPrefix => TypeNS,
426 PathSource::Expr(..) | PathSource::Pat | PathSource::TupleStruct => ValueNS,
427 PathSource::TraitItem(ns) => ns,
431 fn global_by_default(self) -> bool {
433 PathSource::Visibility | PathSource::ImportPrefix => true,
434 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
435 PathSource::Struct | PathSource::TupleStruct |
436 PathSource::Trait(_) | PathSource::TraitItem(..) => false,
440 fn defer_to_typeck(self) -> bool {
442 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
443 PathSource::Struct | PathSource::TupleStruct => true,
444 PathSource::Trait(_) | PathSource::TraitItem(..) |
445 PathSource::Visibility | PathSource::ImportPrefix => false,
449 fn descr_expected(self) -> &'static str {
451 PathSource::Type => "type",
452 PathSource::Trait(_) => "trait",
453 PathSource::Pat => "unit struct/variant or constant",
454 PathSource::Struct => "struct, variant or union type",
455 PathSource::TupleStruct => "tuple struct/variant",
456 PathSource::Visibility => "module",
457 PathSource::ImportPrefix => "module or enum",
458 PathSource::TraitItem(ns) => match ns {
459 TypeNS => "associated type",
460 ValueNS => "method or associated constant",
461 MacroNS => bug!("associated macro"),
463 PathSource::Expr(parent) => match parent.map(|p| &p.node) {
464 // "function" here means "anything callable" rather than `Def::Fn`,
465 // this is not precise but usually more helpful than just "value".
466 Some(&ExprKind::Call(..)) => "function",
472 fn is_expected(self, def: Def) -> bool {
474 PathSource::Type => match def {
475 Def::Struct(..) | Def::Union(..) | Def::Enum(..) |
476 Def::Trait(..) | Def::TyAlias(..) | Def::AssociatedTy(..) |
477 Def::PrimTy(..) | Def::TyParam(..) | Def::SelfTy(..) |
478 Def::TyForeign(..) => true,
481 PathSource::Trait(AliasPossibility::No) => match def {
482 Def::Trait(..) => true,
485 PathSource::Trait(AliasPossibility::Maybe) => match def {
486 Def::Trait(..) => true,
487 Def::TraitAlias(..) => true,
490 PathSource::Expr(..) => match def {
491 Def::StructCtor(_, CtorKind::Const) | Def::StructCtor(_, CtorKind::Fn) |
492 Def::VariantCtor(_, CtorKind::Const) | Def::VariantCtor(_, CtorKind::Fn) |
493 Def::Const(..) | Def::Static(..) | Def::Local(..) | Def::Upvar(..) |
494 Def::Fn(..) | Def::Method(..) | Def::AssociatedConst(..) => true,
497 PathSource::Pat => match def {
498 Def::StructCtor(_, CtorKind::Const) |
499 Def::VariantCtor(_, CtorKind::Const) |
500 Def::Const(..) | Def::AssociatedConst(..) => true,
503 PathSource::TupleStruct => match def {
504 Def::StructCtor(_, CtorKind::Fn) | Def::VariantCtor(_, CtorKind::Fn) => true,
507 PathSource::Struct => match def {
508 Def::Struct(..) | Def::Union(..) | Def::Variant(..) |
509 Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) => true,
512 PathSource::TraitItem(ns) => match def {
513 Def::AssociatedConst(..) | Def::Method(..) if ns == ValueNS => true,
514 Def::AssociatedTy(..) if ns == TypeNS => true,
517 PathSource::ImportPrefix => match def {
518 Def::Mod(..) | Def::Enum(..) => true,
521 PathSource::Visibility => match def {
522 Def::Mod(..) => true,
528 fn error_code(self, has_unexpected_resolution: bool) -> &'static str {
529 __diagnostic_used!(E0404);
530 __diagnostic_used!(E0405);
531 __diagnostic_used!(E0412);
532 __diagnostic_used!(E0422);
533 __diagnostic_used!(E0423);
534 __diagnostic_used!(E0425);
535 __diagnostic_used!(E0531);
536 __diagnostic_used!(E0532);
537 __diagnostic_used!(E0573);
538 __diagnostic_used!(E0574);
539 __diagnostic_used!(E0575);
540 __diagnostic_used!(E0576);
541 __diagnostic_used!(E0577);
542 __diagnostic_used!(E0578);
543 match (self, has_unexpected_resolution) {
544 (PathSource::Trait(_), true) => "E0404",
545 (PathSource::Trait(_), false) => "E0405",
546 (PathSource::Type, true) => "E0573",
547 (PathSource::Type, false) => "E0412",
548 (PathSource::Struct, true) => "E0574",
549 (PathSource::Struct, false) => "E0422",
550 (PathSource::Expr(..), true) => "E0423",
551 (PathSource::Expr(..), false) => "E0425",
552 (PathSource::Pat, true) | (PathSource::TupleStruct, true) => "E0532",
553 (PathSource::Pat, false) | (PathSource::TupleStruct, false) => "E0531",
554 (PathSource::TraitItem(..), true) => "E0575",
555 (PathSource::TraitItem(..), false) => "E0576",
556 (PathSource::Visibility, true) | (PathSource::ImportPrefix, true) => "E0577",
557 (PathSource::Visibility, false) | (PathSource::ImportPrefix, false) => "E0578",
562 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
569 #[derive(Clone, Default, Debug)]
570 pub struct PerNS<T> {
576 impl<T> ::std::ops::Index<Namespace> for PerNS<T> {
578 fn index(&self, ns: Namespace) -> &T {
580 ValueNS => &self.value_ns,
581 TypeNS => &self.type_ns,
582 MacroNS => self.macro_ns.as_ref().unwrap(),
587 impl<T> ::std::ops::IndexMut<Namespace> for PerNS<T> {
588 fn index_mut(&mut self, ns: Namespace) -> &mut T {
590 ValueNS => &mut self.value_ns,
591 TypeNS => &mut self.type_ns,
592 MacroNS => self.macro_ns.as_mut().unwrap(),
597 struct UsePlacementFinder {
598 target_module: NodeId,
603 impl UsePlacementFinder {
604 fn check(krate: &Crate, target_module: NodeId) -> (Option<Span>, bool) {
605 let mut finder = UsePlacementFinder {
610 visit::walk_crate(&mut finder, krate);
611 (finder.span, finder.found_use)
615 impl<'tcx> Visitor<'tcx> for UsePlacementFinder {
618 module: &'tcx ast::Mod,
620 _: &[ast::Attribute],
623 if self.span.is_some() {
626 if node_id != self.target_module {
627 visit::walk_mod(self, module);
630 // find a use statement
631 for item in &module.items {
633 ItemKind::Use(..) => {
634 // don't suggest placing a use before the prelude
635 // import or other generated ones
636 if item.span.ctxt().outer().expn_info().is_none() {
637 self.span = Some(item.span.with_hi(item.span.lo()));
638 self.found_use = true;
642 // don't place use before extern crate
643 ItemKind::ExternCrate(_) => {}
644 // but place them before the first other item
645 _ => if self.span.map_or(true, |span| item.span < span ) {
646 if item.span.ctxt().outer().expn_info().is_none() {
647 // don't insert between attributes and an item
648 if item.attrs.is_empty() {
649 self.span = Some(item.span.with_hi(item.span.lo()));
651 // find the first attribute on the item
652 for attr in &item.attrs {
653 if self.span.map_or(true, |span| attr.span < span) {
654 self.span = Some(attr.span.with_hi(attr.span.lo()));
665 impl<'a, 'tcx> Visitor<'tcx> for Resolver<'a> {
666 fn visit_item(&mut self, item: &'tcx Item) {
667 self.resolve_item(item);
669 fn visit_arm(&mut self, arm: &'tcx Arm) {
670 self.resolve_arm(arm);
672 fn visit_block(&mut self, block: &'tcx Block) {
673 self.resolve_block(block);
675 fn visit_expr(&mut self, expr: &'tcx Expr) {
676 self.resolve_expr(expr, None);
678 fn visit_local(&mut self, local: &'tcx Local) {
679 self.resolve_local(local);
681 fn visit_ty(&mut self, ty: &'tcx Ty) {
683 TyKind::Path(ref qself, ref path) => {
684 self.smart_resolve_path(ty.id, qself.as_ref(), path, PathSource::Type);
686 TyKind::ImplicitSelf => {
687 let self_ty = keywords::SelfType.ident();
688 let def = self.resolve_ident_in_lexical_scope(self_ty, TypeNS, true, ty.span)
689 .map_or(Def::Err, |d| d.def());
690 self.record_def(ty.id, PathResolution::new(def));
692 TyKind::Array(ref element, ref length) => {
693 self.visit_ty(element);
694 self.with_constant_rib(|this| {
695 this.visit_expr(length);
701 visit::walk_ty(self, ty);
703 fn visit_poly_trait_ref(&mut self,
704 tref: &'tcx ast::PolyTraitRef,
705 m: &'tcx ast::TraitBoundModifier) {
706 self.smart_resolve_path(tref.trait_ref.ref_id, None,
707 &tref.trait_ref.path, PathSource::Trait(AliasPossibility::Maybe));
708 visit::walk_poly_trait_ref(self, tref, m);
710 fn visit_variant(&mut self,
711 variant: &'tcx ast::Variant,
712 generics: &'tcx Generics,
713 item_id: ast::NodeId) {
714 if let Some(ref dis_expr) = variant.node.disr_expr {
715 // resolve the discriminator expr as a constant
716 self.with_constant_rib(|this| {
717 this.visit_expr(dis_expr);
721 // `visit::walk_variant` without the discriminant expression.
722 self.visit_variant_data(&variant.node.data,
728 fn visit_foreign_item(&mut self, foreign_item: &'tcx ForeignItem) {
729 let type_parameters = match foreign_item.node {
730 ForeignItemKind::Fn(_, ref generics) => {
731 HasTypeParameters(generics, ItemRibKind)
733 ForeignItemKind::Static(..) => NoTypeParameters,
734 ForeignItemKind::Ty => NoTypeParameters,
736 self.with_type_parameter_rib(type_parameters, |this| {
737 visit::walk_foreign_item(this, foreign_item);
740 fn visit_fn(&mut self,
741 function_kind: FnKind<'tcx>,
742 declaration: &'tcx FnDecl,
745 let rib_kind = match function_kind {
746 FnKind::ItemFn(..) => {
749 FnKind::Method(_, _, _, _) => {
750 TraitOrImplItemRibKind
752 FnKind::Closure(_) => ClosureRibKind(node_id),
755 // Create a value rib for the function.
756 self.ribs[ValueNS].push(Rib::new(rib_kind));
758 // Create a label rib for the function.
759 self.label_ribs.push(Rib::new(rib_kind));
761 // Add each argument to the rib.
762 let mut bindings_list = FxHashMap();
763 for argument in &declaration.inputs {
764 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
766 self.visit_ty(&argument.ty);
768 debug!("(resolving function) recorded argument");
770 visit::walk_fn_ret_ty(self, &declaration.output);
772 // Resolve the function body.
773 match function_kind {
774 FnKind::ItemFn(.., body) |
775 FnKind::Method(.., body) => {
776 self.visit_block(body);
778 FnKind::Closure(body) => {
779 self.visit_expr(body);
783 debug!("(resolving function) leaving function");
785 self.label_ribs.pop();
786 self.ribs[ValueNS].pop();
788 fn visit_generics(&mut self, generics: &'tcx Generics) {
789 // For type parameter defaults, we have to ban access
790 // to following type parameters, as the Substs can only
791 // provide previous type parameters as they're built.
792 let mut default_ban_rib = Rib::new(ForwardTyParamBanRibKind);
793 default_ban_rib.bindings.extend(generics.params.iter()
794 .filter_map(|p| if let GenericParam::Type(ref tp) = *p { Some(tp) } else { None })
795 .skip_while(|p| p.default.is_none())
796 .map(|p| (Ident::with_empty_ctxt(p.ident.name), Def::Err)));
798 for param in &generics.params {
800 GenericParam::Lifetime(_) => self.visit_generic_param(param),
801 GenericParam::Type(ref ty_param) => {
802 for bound in &ty_param.bounds {
803 self.visit_ty_param_bound(bound);
806 if let Some(ref ty) = ty_param.default {
807 self.ribs[TypeNS].push(default_ban_rib);
809 default_ban_rib = self.ribs[TypeNS].pop().unwrap();
812 // Allow all following defaults to refer to this type parameter.
813 default_ban_rib.bindings.remove(&Ident::with_empty_ctxt(ty_param.ident.name));
817 for p in &generics.where_clause.predicates { self.visit_where_predicate(p); }
821 #[derive(Copy, Clone)]
822 enum TypeParameters<'a, 'b> {
824 HasTypeParameters(// Type parameters.
827 // The kind of the rib used for type parameters.
831 // The rib kind controls the translation of local
832 // definitions (`Def::Local`) to upvars (`Def::Upvar`).
833 #[derive(Copy, Clone, Debug)]
835 // No translation needs to be applied.
838 // We passed through a closure scope at the given node ID.
839 // Translate upvars as appropriate.
840 ClosureRibKind(NodeId /* func id */),
842 // We passed through an impl or trait and are now in one of its
843 // methods or associated types. Allow references to ty params that impl or trait
844 // binds. Disallow any other upvars (including other ty params that are
846 TraitOrImplItemRibKind,
848 // We passed through an item scope. Disallow upvars.
851 // We're in a constant item. Can't refer to dynamic stuff.
854 // We passed through a module.
855 ModuleRibKind(Module<'a>),
857 // We passed through a `macro_rules!` statement
858 MacroDefinition(DefId),
860 // All bindings in this rib are type parameters that can't be used
861 // from the default of a type parameter because they're not declared
862 // before said type parameter. Also see the `visit_generics` override.
863 ForwardTyParamBanRibKind,
869 bindings: FxHashMap<Ident, Def>,
874 fn new(kind: RibKind<'a>) -> Rib<'a> {
876 bindings: FxHashMap(),
882 enum LexicalScopeBinding<'a> {
883 Item(&'a NameBinding<'a>),
887 impl<'a> LexicalScopeBinding<'a> {
888 fn item(self) -> Option<&'a NameBinding<'a>> {
890 LexicalScopeBinding::Item(binding) => Some(binding),
895 fn def(self) -> Def {
897 LexicalScopeBinding::Item(binding) => binding.def(),
898 LexicalScopeBinding::Def(def) => def,
903 #[derive(Clone, Debug)]
904 enum PathResult<'a> {
906 NonModule(PathResolution),
908 Failed(Span, String, bool /* is the error from the last segment? */),
916 /// One node in the tree of modules.
917 pub struct ModuleData<'a> {
918 parent: Option<Module<'a>>,
921 // The def id of the closest normal module (`mod`) ancestor (including this module).
922 normal_ancestor_id: DefId,
924 resolutions: RefCell<FxHashMap<(Ident, Namespace), &'a RefCell<NameResolution<'a>>>>,
925 legacy_macro_resolutions: RefCell<Vec<(Mark, Ident, Span, MacroKind)>>,
926 macro_resolutions: RefCell<Vec<(Box<[Ident]>, Span)>>,
928 // Macro invocations that can expand into items in this module.
929 unresolved_invocations: RefCell<FxHashSet<Mark>>,
931 no_implicit_prelude: bool,
933 glob_importers: RefCell<Vec<&'a ImportDirective<'a>>>,
934 globs: RefCell<Vec<&'a ImportDirective<'a>>>,
936 // Used to memoize the traits in this module for faster searches through all traits in scope.
937 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
939 // Whether this module is populated. If not populated, any attempt to
940 // access the children must be preceded with a
941 // `populate_module_if_necessary` call.
942 populated: Cell<bool>,
944 /// Span of the module itself. Used for error reporting.
950 type Module<'a> = &'a ModuleData<'a>;
952 impl<'a> ModuleData<'a> {
953 fn new(parent: Option<Module<'a>>,
955 normal_ancestor_id: DefId,
957 span: Span) -> Self {
962 resolutions: RefCell::new(FxHashMap()),
963 legacy_macro_resolutions: RefCell::new(Vec::new()),
964 macro_resolutions: RefCell::new(Vec::new()),
965 unresolved_invocations: RefCell::new(FxHashSet()),
966 no_implicit_prelude: false,
967 glob_importers: RefCell::new(Vec::new()),
968 globs: RefCell::new(Vec::new()),
969 traits: RefCell::new(None),
970 populated: Cell::new(normal_ancestor_id.is_local()),
976 fn for_each_child<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
977 for (&(ident, ns), name_resolution) in self.resolutions.borrow().iter() {
978 name_resolution.borrow().binding.map(|binding| f(ident, ns, binding));
982 fn for_each_child_stable<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
983 let resolutions = self.resolutions.borrow();
984 let mut resolutions = resolutions.iter().map(|(&(ident, ns), &resolution)| {
985 // Pre-compute keys for sorting
986 (ident.name.as_str(), ns, ident, resolution)
988 .collect::<Vec<_>>();
989 resolutions.sort_unstable_by_key(|&(str, ns, ..)| (str, ns));
990 for &(_, ns, ident, resolution) in resolutions.iter() {
991 resolution.borrow().binding.map(|binding| f(ident, ns, binding));
995 fn def(&self) -> Option<Def> {
997 ModuleKind::Def(def, _) => Some(def),
1002 fn def_id(&self) -> Option<DefId> {
1003 self.def().as_ref().map(Def::def_id)
1006 // `self` resolves to the first module ancestor that `is_normal`.
1007 fn is_normal(&self) -> bool {
1009 ModuleKind::Def(Def::Mod(_), _) => true,
1014 fn is_trait(&self) -> bool {
1016 ModuleKind::Def(Def::Trait(_), _) => true,
1021 fn is_local(&self) -> bool {
1022 self.normal_ancestor_id.is_local()
1025 fn nearest_item_scope(&'a self) -> Module<'a> {
1026 if self.is_trait() { self.parent.unwrap() } else { self }
1030 impl<'a> fmt::Debug for ModuleData<'a> {
1031 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1032 write!(f, "{:?}", self.def())
1036 // Records a possibly-private value, type, or module definition.
1037 #[derive(Clone, Debug)]
1038 pub struct NameBinding<'a> {
1039 kind: NameBindingKind<'a>,
1042 vis: ty::Visibility,
1045 pub trait ToNameBinding<'a> {
1046 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
1049 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
1050 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
1055 #[derive(Clone, Debug)]
1056 enum NameBindingKind<'a> {
1060 binding: &'a NameBinding<'a>,
1061 directive: &'a ImportDirective<'a>,
1063 legacy_self_import: bool,
1066 b1: &'a NameBinding<'a>,
1067 b2: &'a NameBinding<'a>,
1072 struct PrivacyError<'a>(Span, Name, &'a NameBinding<'a>);
1074 struct UseError<'a> {
1075 err: DiagnosticBuilder<'a>,
1076 /// Attach `use` statements for these candidates
1077 candidates: Vec<ImportSuggestion>,
1078 /// The node id of the module to place the use statements in
1080 /// Whether the diagnostic should state that it's "better"
1084 struct AmbiguityError<'a> {
1088 b1: &'a NameBinding<'a>,
1089 b2: &'a NameBinding<'a>,
1093 impl<'a> NameBinding<'a> {
1094 fn module(&self) -> Option<Module<'a>> {
1096 NameBindingKind::Module(module) => Some(module),
1097 NameBindingKind::Import { binding, .. } => binding.module(),
1098 NameBindingKind::Ambiguity { legacy: true, b1, .. } => b1.module(),
1103 fn def(&self) -> Def {
1105 NameBindingKind::Def(def) => def,
1106 NameBindingKind::Module(module) => module.def().unwrap(),
1107 NameBindingKind::Import { binding, .. } => binding.def(),
1108 NameBindingKind::Ambiguity { legacy: true, b1, .. } => b1.def(),
1109 NameBindingKind::Ambiguity { .. } => Def::Err,
1113 fn def_ignoring_ambiguity(&self) -> Def {
1115 NameBindingKind::Import { binding, .. } => binding.def_ignoring_ambiguity(),
1116 NameBindingKind::Ambiguity { b1, .. } => b1.def_ignoring_ambiguity(),
1121 fn get_macro(&self, resolver: &mut Resolver<'a>) -> Lrc<SyntaxExtension> {
1122 resolver.get_macro(self.def_ignoring_ambiguity())
1125 // We sometimes need to treat variants as `pub` for backwards compatibility
1126 fn pseudo_vis(&self) -> ty::Visibility {
1127 if self.is_variant() && self.def().def_id().is_local() {
1128 ty::Visibility::Public
1134 fn is_variant(&self) -> bool {
1136 NameBindingKind::Def(Def::Variant(..)) |
1137 NameBindingKind::Def(Def::VariantCtor(..)) => true,
1142 fn is_extern_crate(&self) -> bool {
1144 NameBindingKind::Import {
1145 directive: &ImportDirective {
1146 subclass: ImportDirectiveSubclass::ExternCrate(_), ..
1153 fn is_import(&self) -> bool {
1155 NameBindingKind::Import { .. } => true,
1160 fn is_renamed_extern_crate(&self) -> bool {
1161 if let NameBindingKind::Import { directive, ..} = self.kind {
1162 if let ImportDirectiveSubclass::ExternCrate(Some(_)) = directive.subclass {
1169 fn is_glob_import(&self) -> bool {
1171 NameBindingKind::Import { directive, .. } => directive.is_glob(),
1172 NameBindingKind::Ambiguity { b1, .. } => b1.is_glob_import(),
1177 fn is_importable(&self) -> bool {
1179 Def::AssociatedConst(..) | Def::Method(..) | Def::AssociatedTy(..) => false,
1184 fn is_macro_def(&self) -> bool {
1186 NameBindingKind::Def(Def::Macro(..)) => true,
1191 fn descr(&self) -> &'static str {
1192 if self.is_extern_crate() { "extern crate" } else { self.def().kind_name() }
1196 /// Interns the names of the primitive types.
1197 struct PrimitiveTypeTable {
1198 primitive_types: FxHashMap<Name, PrimTy>,
1201 impl PrimitiveTypeTable {
1202 fn new() -> PrimitiveTypeTable {
1203 let mut table = PrimitiveTypeTable { primitive_types: FxHashMap() };
1205 table.intern("bool", TyBool);
1206 table.intern("char", TyChar);
1207 table.intern("f32", TyFloat(FloatTy::F32));
1208 table.intern("f64", TyFloat(FloatTy::F64));
1209 table.intern("isize", TyInt(IntTy::Isize));
1210 table.intern("i8", TyInt(IntTy::I8));
1211 table.intern("i16", TyInt(IntTy::I16));
1212 table.intern("i32", TyInt(IntTy::I32));
1213 table.intern("i64", TyInt(IntTy::I64));
1214 table.intern("i128", TyInt(IntTy::I128));
1215 table.intern("str", TyStr);
1216 table.intern("usize", TyUint(UintTy::Usize));
1217 table.intern("u8", TyUint(UintTy::U8));
1218 table.intern("u16", TyUint(UintTy::U16));
1219 table.intern("u32", TyUint(UintTy::U32));
1220 table.intern("u64", TyUint(UintTy::U64));
1221 table.intern("u128", TyUint(UintTy::U128));
1225 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1226 self.primitive_types.insert(Symbol::intern(string), primitive_type);
1230 /// The main resolver class.
1231 pub struct Resolver<'a> {
1232 session: &'a Session,
1233 cstore: &'a CrateStore,
1235 pub definitions: Definitions,
1237 graph_root: Module<'a>,
1239 prelude: Option<Module<'a>>,
1241 // n.b. This is used only for better diagnostics, not name resolution itself.
1242 has_self: FxHashSet<DefId>,
1244 // Names of fields of an item `DefId` accessible with dot syntax.
1245 // Used for hints during error reporting.
1246 field_names: FxHashMap<DefId, Vec<Name>>,
1248 // All imports known to succeed or fail.
1249 determined_imports: Vec<&'a ImportDirective<'a>>,
1251 // All non-determined imports.
1252 indeterminate_imports: Vec<&'a ImportDirective<'a>>,
1254 // The module that represents the current item scope.
1255 current_module: Module<'a>,
1257 // The current set of local scopes for types and values.
1258 // FIXME #4948: Reuse ribs to avoid allocation.
1259 ribs: PerNS<Vec<Rib<'a>>>,
1261 // The current set of local scopes, for labels.
1262 label_ribs: Vec<Rib<'a>>,
1264 // The trait that the current context can refer to.
1265 current_trait_ref: Option<(Module<'a>, TraitRef)>,
1267 // The current self type if inside an impl (used for better errors).
1268 current_self_type: Option<Ty>,
1270 // The idents for the primitive types.
1271 primitive_type_table: PrimitiveTypeTable,
1274 pub freevars: FreevarMap,
1275 freevars_seen: NodeMap<NodeMap<usize>>,
1276 pub export_map: ExportMap,
1277 pub trait_map: TraitMap,
1279 // A map from nodes to anonymous modules.
1280 // Anonymous modules are pseudo-modules that are implicitly created around items
1281 // contained within blocks.
1283 // For example, if we have this:
1291 // There will be an anonymous module created around `g` with the ID of the
1292 // entry block for `f`.
1293 block_map: NodeMap<Module<'a>>,
1294 module_map: FxHashMap<DefId, Module<'a>>,
1295 extern_module_map: FxHashMap<(DefId, bool /* MacrosOnly? */), Module<'a>>,
1297 pub make_glob_map: bool,
1298 /// Maps imports to the names of items actually imported (this actually maps
1299 /// all imports, but only glob imports are actually interesting).
1300 pub glob_map: GlobMap,
1302 used_imports: FxHashSet<(NodeId, Namespace)>,
1303 pub maybe_unused_trait_imports: NodeSet,
1304 pub maybe_unused_extern_crates: Vec<(NodeId, Span)>,
1306 /// privacy errors are delayed until the end in order to deduplicate them
1307 privacy_errors: Vec<PrivacyError<'a>>,
1308 /// ambiguity errors are delayed for deduplication
1309 ambiguity_errors: Vec<AmbiguityError<'a>>,
1310 /// `use` injections are delayed for better placement and deduplication
1311 use_injections: Vec<UseError<'a>>,
1312 /// `use` injections for proc macros wrongly imported with #[macro_use]
1313 proc_mac_errors: Vec<macros::ProcMacError>,
1315 gated_errors: FxHashSet<Span>,
1316 disallowed_shadowing: Vec<&'a LegacyBinding<'a>>,
1318 arenas: &'a ResolverArenas<'a>,
1319 dummy_binding: &'a NameBinding<'a>,
1320 use_extern_macros: bool, // true if `#![feature(use_extern_macros)]`
1322 crate_loader: &'a mut CrateLoader,
1323 macro_names: FxHashSet<Ident>,
1324 global_macros: FxHashMap<Name, &'a NameBinding<'a>>,
1325 pub all_macros: FxHashMap<Name, Def>,
1326 lexical_macro_resolutions: Vec<(Ident, &'a Cell<LegacyScope<'a>>)>,
1327 macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>,
1328 macro_defs: FxHashMap<Mark, DefId>,
1329 local_macro_def_scopes: FxHashMap<NodeId, Module<'a>>,
1330 macro_exports: Vec<Export>,
1331 pub whitelisted_legacy_custom_derives: Vec<Name>,
1332 pub found_unresolved_macro: bool,
1334 // List of crate local macros that we need to warn about as being unused.
1335 // Right now this only includes macro_rules! macros, and macros 2.0.
1336 unused_macros: FxHashSet<DefId>,
1338 // Maps the `Mark` of an expansion to its containing module or block.
1339 invocations: FxHashMap<Mark, &'a InvocationData<'a>>,
1341 // Avoid duplicated errors for "name already defined".
1342 name_already_seen: FxHashMap<Name, Span>,
1344 // If `#![feature(proc_macro)]` is set
1345 proc_macro_enabled: bool,
1347 // A set of procedural macros imported by `#[macro_use]` that have already been warned about
1348 warned_proc_macros: FxHashSet<Name>,
1350 potentially_unused_imports: Vec<&'a ImportDirective<'a>>,
1352 // This table maps struct IDs into struct constructor IDs,
1353 // it's not used during normal resolution, only for better error reporting.
1354 struct_constructors: DefIdMap<(Def, ty::Visibility)>,
1356 // Only used for better errors on `fn(): fn()`
1357 current_type_ascription: Vec<Span>,
1359 injected_crate: Option<Module<'a>>,
1362 pub struct ResolverArenas<'a> {
1363 modules: arena::TypedArena<ModuleData<'a>>,
1364 local_modules: RefCell<Vec<Module<'a>>>,
1365 name_bindings: arena::TypedArena<NameBinding<'a>>,
1366 import_directives: arena::TypedArena<ImportDirective<'a>>,
1367 name_resolutions: arena::TypedArena<RefCell<NameResolution<'a>>>,
1368 invocation_data: arena::TypedArena<InvocationData<'a>>,
1369 legacy_bindings: arena::TypedArena<LegacyBinding<'a>>,
1372 impl<'a> ResolverArenas<'a> {
1373 fn alloc_module(&'a self, module: ModuleData<'a>) -> Module<'a> {
1374 let module = self.modules.alloc(module);
1375 if module.def_id().map(|def_id| def_id.is_local()).unwrap_or(true) {
1376 self.local_modules.borrow_mut().push(module);
1380 fn local_modules(&'a self) -> ::std::cell::Ref<'a, Vec<Module<'a>>> {
1381 self.local_modules.borrow()
1383 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1384 self.name_bindings.alloc(name_binding)
1386 fn alloc_import_directive(&'a self, import_directive: ImportDirective<'a>)
1387 -> &'a ImportDirective {
1388 self.import_directives.alloc(import_directive)
1390 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1391 self.name_resolutions.alloc(Default::default())
1393 fn alloc_invocation_data(&'a self, expansion_data: InvocationData<'a>)
1394 -> &'a InvocationData<'a> {
1395 self.invocation_data.alloc(expansion_data)
1397 fn alloc_legacy_binding(&'a self, binding: LegacyBinding<'a>) -> &'a LegacyBinding<'a> {
1398 self.legacy_bindings.alloc(binding)
1402 impl<'a, 'b: 'a> ty::DefIdTree for &'a Resolver<'b> {
1403 fn parent(self, id: DefId) -> Option<DefId> {
1405 LOCAL_CRATE => self.definitions.def_key(id.index).parent,
1406 _ => self.cstore.def_key(id).parent,
1407 }.map(|index| DefId { index: index, ..id })
1411 impl<'a> hir::lowering::Resolver for Resolver<'a> {
1412 fn resolve_hir_path(&mut self, path: &mut hir::Path, is_value: bool) {
1413 self.resolve_hir_path_cb(path, is_value,
1414 |resolver, span, error| resolve_error(resolver, span, error))
1417 fn resolve_str_path(&mut self, span: Span, crate_root: Option<&str>,
1418 components: &[&str], is_value: bool) -> hir::Path {
1419 let mut path = hir::Path {
1422 segments: iter::once(keywords::CrateRoot.name()).chain({
1423 crate_root.into_iter().chain(components.iter().cloned()).map(Symbol::intern)
1424 }).map(hir::PathSegment::from_name).collect(),
1427 self.resolve_hir_path(&mut path, is_value);
1431 fn get_resolution(&mut self, id: NodeId) -> Option<PathResolution> {
1432 self.def_map.get(&id).cloned()
1435 fn definitions(&mut self) -> &mut Definitions {
1436 &mut self.definitions
1440 impl<'a> Resolver<'a> {
1441 /// Rustdoc uses this to resolve things in a recoverable way. ResolutionError<'a>
1442 /// isn't something that can be returned because it can't be made to live that long,
1443 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
1444 /// just that an error occurred.
1445 pub fn resolve_str_path_error(&mut self, span: Span, path_str: &str, is_value: bool)
1446 -> Result<hir::Path, ()> {
1448 let mut errored = false;
1450 let mut path = if path_str.starts_with("::") {
1454 segments: iter::once(keywords::CrateRoot.name()).chain({
1455 path_str.split("::").skip(1).map(Symbol::intern)
1456 }).map(hir::PathSegment::from_name).collect(),
1462 segments: path_str.split("::").map(Symbol::intern)
1463 .map(hir::PathSegment::from_name).collect(),
1466 self.resolve_hir_path_cb(&mut path, is_value, |_, _, _| errored = true);
1467 if errored || path.def == Def::Err {
1474 /// resolve_hir_path, but takes a callback in case there was an error
1475 fn resolve_hir_path_cb<F>(&mut self, path: &mut hir::Path, is_value: bool, error_callback: F)
1476 where F: for<'c, 'b> FnOnce(&'c mut Resolver, Span, ResolutionError<'b>)
1478 let namespace = if is_value { ValueNS } else { TypeNS };
1479 let hir::Path { ref segments, span, ref mut def } = *path;
1480 let path: Vec<SpannedIdent> = segments.iter()
1481 .map(|seg| respan(span, Ident::with_empty_ctxt(seg.name)))
1483 match self.resolve_path(&path, Some(namespace), true, span) {
1484 PathResult::Module(module) => *def = module.def().unwrap(),
1485 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 =>
1486 *def = path_res.base_def(),
1487 PathResult::NonModule(..) => match self.resolve_path(&path, None, true, span) {
1488 PathResult::Failed(span, msg, _) => {
1489 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1493 PathResult::Indeterminate => unreachable!(),
1494 PathResult::Failed(span, msg, _) => {
1495 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1501 impl<'a> Resolver<'a> {
1502 pub fn new(session: &'a Session,
1503 cstore: &'a CrateStore,
1506 make_glob_map: MakeGlobMap,
1507 crate_loader: &'a mut CrateLoader,
1508 arenas: &'a ResolverArenas<'a>)
1510 let root_def_id = DefId::local(CRATE_DEF_INDEX);
1511 let root_module_kind = ModuleKind::Def(Def::Mod(root_def_id), keywords::Invalid.name());
1512 let graph_root = arenas.alloc_module(ModuleData {
1513 no_implicit_prelude: attr::contains_name(&krate.attrs, "no_implicit_prelude"),
1514 ..ModuleData::new(None, root_module_kind, root_def_id, Mark::root(), krate.span)
1516 let mut module_map = FxHashMap();
1517 module_map.insert(DefId::local(CRATE_DEF_INDEX), graph_root);
1519 let mut definitions = Definitions::new();
1520 DefCollector::new(&mut definitions, Mark::root())
1521 .collect_root(crate_name, session.local_crate_disambiguator());
1523 let mut invocations = FxHashMap();
1524 invocations.insert(Mark::root(),
1525 arenas.alloc_invocation_data(InvocationData::root(graph_root)));
1527 let features = session.features_untracked();
1529 let mut macro_defs = FxHashMap();
1530 macro_defs.insert(Mark::root(), root_def_id);
1539 // The outermost module has def ID 0; this is not reflected in the
1544 has_self: FxHashSet(),
1545 field_names: FxHashMap(),
1547 determined_imports: Vec::new(),
1548 indeterminate_imports: Vec::new(),
1550 current_module: graph_root,
1552 value_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1553 type_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1554 macro_ns: Some(vec![Rib::new(ModuleRibKind(graph_root))]),
1556 label_ribs: Vec::new(),
1558 current_trait_ref: None,
1559 current_self_type: None,
1561 primitive_type_table: PrimitiveTypeTable::new(),
1564 freevars: NodeMap(),
1565 freevars_seen: NodeMap(),
1566 export_map: FxHashMap(),
1567 trait_map: NodeMap(),
1569 block_map: NodeMap(),
1570 extern_module_map: FxHashMap(),
1572 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1573 glob_map: NodeMap(),
1575 used_imports: FxHashSet(),
1576 maybe_unused_trait_imports: NodeSet(),
1577 maybe_unused_extern_crates: Vec::new(),
1579 privacy_errors: Vec::new(),
1580 ambiguity_errors: Vec::new(),
1581 use_injections: Vec::new(),
1582 proc_mac_errors: Vec::new(),
1583 gated_errors: FxHashSet(),
1584 disallowed_shadowing: Vec::new(),
1587 dummy_binding: arenas.alloc_name_binding(NameBinding {
1588 kind: NameBindingKind::Def(Def::Err),
1589 expansion: Mark::root(),
1591 vis: ty::Visibility::Public,
1594 // The `proc_macro` and `decl_macro` features imply `use_extern_macros`
1596 features.use_extern_macros || features.proc_macro || features.decl_macro,
1599 macro_names: FxHashSet(),
1600 global_macros: FxHashMap(),
1601 all_macros: FxHashMap(),
1602 lexical_macro_resolutions: Vec::new(),
1603 macro_map: FxHashMap(),
1604 macro_exports: Vec::new(),
1607 local_macro_def_scopes: FxHashMap(),
1608 name_already_seen: FxHashMap(),
1609 whitelisted_legacy_custom_derives: Vec::new(),
1610 proc_macro_enabled: features.proc_macro,
1611 warned_proc_macros: FxHashSet(),
1612 potentially_unused_imports: Vec::new(),
1613 struct_constructors: DefIdMap(),
1614 found_unresolved_macro: false,
1615 unused_macros: FxHashSet(),
1616 current_type_ascription: Vec::new(),
1617 injected_crate: None,
1621 pub fn arenas() -> ResolverArenas<'a> {
1623 modules: arena::TypedArena::new(),
1624 local_modules: RefCell::new(Vec::new()),
1625 name_bindings: arena::TypedArena::new(),
1626 import_directives: arena::TypedArena::new(),
1627 name_resolutions: arena::TypedArena::new(),
1628 invocation_data: arena::TypedArena::new(),
1629 legacy_bindings: arena::TypedArena::new(),
1633 fn per_ns<T, F: FnMut(&mut Self, Namespace) -> T>(&mut self, mut f: F) -> PerNS<T> {
1635 type_ns: f(self, TypeNS),
1636 value_ns: f(self, ValueNS),
1637 macro_ns: match self.use_extern_macros {
1638 true => Some(f(self, MacroNS)),
1644 fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
1646 match self.macro_defs.get(&ctxt.outer()) {
1647 Some(&def_id) => return def_id,
1648 None => ctxt.remove_mark(),
1653 /// Entry point to crate resolution.
1654 pub fn resolve_crate(&mut self, krate: &Crate) {
1655 ImportResolver { resolver: self }.finalize_imports();
1656 self.current_module = self.graph_root;
1657 self.finalize_current_module_macro_resolutions();
1659 visit::walk_crate(self, krate);
1661 check_unused::check_crate(self, krate);
1662 self.report_errors(krate);
1663 self.crate_loader.postprocess(krate);
1670 normal_ancestor_id: DefId,
1674 let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expansion, span);
1675 self.arenas.alloc_module(module)
1678 fn record_use(&mut self, ident: Ident, ns: Namespace, binding: &'a NameBinding<'a>, span: Span)
1679 -> bool /* true if an error was reported */ {
1680 match binding.kind {
1681 NameBindingKind::Import { directive, binding, ref used, legacy_self_import }
1684 directive.used.set(true);
1685 if legacy_self_import {
1686 self.warn_legacy_self_import(directive);
1689 self.used_imports.insert((directive.id, ns));
1690 self.add_to_glob_map(directive.id, ident);
1691 self.record_use(ident, ns, binding, span)
1693 NameBindingKind::Import { .. } => false,
1694 NameBindingKind::Ambiguity { b1, b2, legacy } => {
1695 self.ambiguity_errors.push(AmbiguityError {
1696 span: span, name: ident.name, lexical: false, b1: b1, b2: b2, legacy,
1699 self.record_use(ident, ns, b1, span);
1707 fn add_to_glob_map(&mut self, id: NodeId, ident: Ident) {
1708 if self.make_glob_map {
1709 self.glob_map.entry(id).or_insert_with(FxHashSet).insert(ident.name);
1713 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1714 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1715 /// `ident` in the first scope that defines it (or None if no scopes define it).
1717 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1718 /// the items are defined in the block. For example,
1721 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1724 /// g(); // This resolves to the local variable `g` since it shadows the item.
1728 /// Invariant: This must only be called during main resolution, not during
1729 /// import resolution.
1730 fn resolve_ident_in_lexical_scope(&mut self,
1735 -> Option<LexicalScopeBinding<'a>> {
1737 ident.ctxt = if ident.name == keywords::SelfType.name() {
1738 SyntaxContext::empty() // FIXME(jseyfried) improve `Self` hygiene
1744 // Walk backwards up the ribs in scope.
1745 let mut module = self.graph_root;
1746 for i in (0 .. self.ribs[ns].len()).rev() {
1747 if let Some(def) = self.ribs[ns][i].bindings.get(&ident).cloned() {
1748 // The ident resolves to a type parameter or local variable.
1749 return Some(LexicalScopeBinding::Def(
1750 self.adjust_local_def(ns, i, def, record_used, path_span)
1754 module = match self.ribs[ns][i].kind {
1755 ModuleRibKind(module) => module,
1756 MacroDefinition(def) if def == self.macro_def(ident.ctxt) => {
1757 // If an invocation of this macro created `ident`, give up on `ident`
1758 // and switch to `ident`'s source from the macro definition.
1759 ident.ctxt.remove_mark();
1765 let item = self.resolve_ident_in_module_unadjusted(
1766 module, ident, ns, false, record_used, path_span,
1768 if let Ok(binding) = item {
1769 // The ident resolves to an item.
1770 return Some(LexicalScopeBinding::Item(binding));
1774 ModuleKind::Block(..) => {}, // We can see through blocks
1779 ident.ctxt = ident.ctxt.modern();
1781 module = unwrap_or!(self.hygienic_lexical_parent(module, &mut ident.ctxt), break);
1782 let orig_current_module = self.current_module;
1783 self.current_module = module; // Lexical resolutions can never be a privacy error.
1784 let result = self.resolve_ident_in_module_unadjusted(
1785 module, ident, ns, false, record_used, path_span,
1787 self.current_module = orig_current_module;
1790 Ok(binding) => return Some(LexicalScopeBinding::Item(binding)),
1791 Err(Undetermined) => return None,
1792 Err(Determined) => {}
1796 match self.prelude {
1797 Some(prelude) if !module.no_implicit_prelude => {
1798 self.resolve_ident_in_module_unadjusted(prelude, ident, ns, false, false, path_span)
1799 .ok().map(LexicalScopeBinding::Item)
1805 fn hygienic_lexical_parent(&mut self, mut module: Module<'a>, ctxt: &mut SyntaxContext)
1806 -> Option<Module<'a>> {
1807 if !module.expansion.is_descendant_of(ctxt.outer()) {
1808 return Some(self.macro_def_scope(ctxt.remove_mark()));
1811 if let ModuleKind::Block(..) = module.kind {
1812 return Some(module.parent.unwrap());
1815 let mut module_expansion = module.expansion.modern(); // for backward compatibility
1816 while let Some(parent) = module.parent {
1817 let parent_expansion = parent.expansion.modern();
1818 if module_expansion.is_descendant_of(parent_expansion) &&
1819 parent_expansion != module_expansion {
1820 return if parent_expansion.is_descendant_of(ctxt.outer()) {
1827 module_expansion = parent_expansion;
1833 fn resolve_ident_in_module(&mut self,
1837 ignore_unresolved_invocations: bool,
1840 -> Result<&'a NameBinding<'a>, Determinacy> {
1841 ident.ctxt = ident.ctxt.modern();
1842 let orig_current_module = self.current_module;
1843 if let Some(def) = ident.ctxt.adjust(module.expansion) {
1844 self.current_module = self.macro_def_scope(def);
1846 let result = self.resolve_ident_in_module_unadjusted(
1847 module, ident, ns, ignore_unresolved_invocations, record_used, span,
1849 self.current_module = orig_current_module;
1853 fn resolve_crate_root(&mut self, mut ctxt: SyntaxContext, legacy: bool) -> Module<'a> {
1854 let mark = if legacy {
1855 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
1856 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
1857 // as described in `SyntaxContext::apply_mark`, so we ignore prepended modern marks.
1858 ctxt.marks().into_iter().find(|&mark| mark.kind() != MarkKind::Modern)
1860 ctxt = ctxt.modern();
1861 ctxt.adjust(Mark::root())
1863 let module = match mark {
1864 Some(def) => self.macro_def_scope(def),
1865 None => return self.graph_root,
1867 self.get_module(DefId { index: CRATE_DEF_INDEX, ..module.normal_ancestor_id })
1870 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
1871 let mut module = self.get_module(module.normal_ancestor_id);
1872 while module.span.ctxt().modern() != *ctxt {
1873 let parent = module.parent.unwrap_or_else(|| self.macro_def_scope(ctxt.remove_mark()));
1874 module = self.get_module(parent.normal_ancestor_id);
1881 // We maintain a list of value ribs and type ribs.
1883 // Simultaneously, we keep track of the current position in the module
1884 // graph in the `current_module` pointer. When we go to resolve a name in
1885 // the value or type namespaces, we first look through all the ribs and
1886 // then query the module graph. When we resolve a name in the module
1887 // namespace, we can skip all the ribs (since nested modules are not
1888 // allowed within blocks in Rust) and jump straight to the current module
1891 // Named implementations are handled separately. When we find a method
1892 // call, we consult the module node to find all of the implementations in
1893 // scope. This information is lazily cached in the module node. We then
1894 // generate a fake "implementation scope" containing all the
1895 // implementations thus found, for compatibility with old resolve pass.
1897 pub fn with_scope<F, T>(&mut self, id: NodeId, f: F) -> T
1898 where F: FnOnce(&mut Resolver) -> T
1900 let id = self.definitions.local_def_id(id);
1901 let module = self.module_map.get(&id).cloned(); // clones a reference
1902 if let Some(module) = module {
1903 // Move down in the graph.
1904 let orig_module = replace(&mut self.current_module, module);
1905 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(module)));
1906 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(module)));
1908 self.finalize_current_module_macro_resolutions();
1911 self.current_module = orig_module;
1912 self.ribs[ValueNS].pop();
1913 self.ribs[TypeNS].pop();
1920 /// Searches the current set of local scopes for labels. Returns the first non-None label that
1921 /// is returned by the given predicate function
1923 /// Stops after meeting a closure.
1924 fn search_label<P, R>(&self, mut ident: Ident, pred: P) -> Option<R>
1925 where P: Fn(&Rib, Ident) -> Option<R>
1927 for rib in self.label_ribs.iter().rev() {
1930 // If an invocation of this macro created `ident`, give up on `ident`
1931 // and switch to `ident`'s source from the macro definition.
1932 MacroDefinition(def) => {
1933 if def == self.macro_def(ident.ctxt) {
1934 ident.ctxt.remove_mark();
1938 // Do not resolve labels across function boundary
1942 let r = pred(rib, ident);
1950 fn resolve_item(&mut self, item: &Item) {
1951 let name = item.ident.name;
1953 debug!("(resolving item) resolving {}", name);
1955 self.check_proc_macro_attrs(&item.attrs);
1958 ItemKind::Enum(_, ref generics) |
1959 ItemKind::Ty(_, ref generics) |
1960 ItemKind::Struct(_, ref generics) |
1961 ItemKind::Union(_, ref generics) |
1962 ItemKind::Fn(.., ref generics, _) => {
1963 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind),
1964 |this| visit::walk_item(this, item));
1967 ItemKind::Impl(.., ref generics, ref opt_trait_ref, ref self_type, ref impl_items) =>
1968 self.resolve_implementation(generics,
1974 ItemKind::Trait(.., ref generics, ref bounds, ref trait_items) => {
1975 // Create a new rib for the trait-wide type parameters.
1976 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
1977 let local_def_id = this.definitions.local_def_id(item.id);
1978 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
1979 this.visit_generics(generics);
1980 walk_list!(this, visit_ty_param_bound, bounds);
1982 for trait_item in trait_items {
1983 this.check_proc_macro_attrs(&trait_item.attrs);
1985 let type_parameters = HasTypeParameters(&trait_item.generics,
1986 TraitOrImplItemRibKind);
1987 this.with_type_parameter_rib(type_parameters, |this| {
1988 match trait_item.node {
1989 TraitItemKind::Const(ref ty, ref default) => {
1992 // Only impose the restrictions of
1993 // ConstRibKind for an actual constant
1994 // expression in a provided default.
1995 if let Some(ref expr) = *default{
1996 this.with_constant_rib(|this| {
1997 this.visit_expr(expr);
2001 TraitItemKind::Method(_, _) => {
2002 visit::walk_trait_item(this, trait_item)
2004 TraitItemKind::Type(..) => {
2005 visit::walk_trait_item(this, trait_item)
2007 TraitItemKind::Macro(_) => {
2008 panic!("unexpanded macro in resolve!")
2017 ItemKind::TraitAlias(ref generics, ref bounds) => {
2018 // Create a new rib for the trait-wide type parameters.
2019 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2020 let local_def_id = this.definitions.local_def_id(item.id);
2021 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2022 this.visit_generics(generics);
2023 walk_list!(this, visit_ty_param_bound, bounds);
2028 ItemKind::Mod(_) | ItemKind::ForeignMod(_) => {
2029 self.with_scope(item.id, |this| {
2030 visit::walk_item(this, item);
2034 ItemKind::Static(ref ty, _, ref expr) |
2035 ItemKind::Const(ref ty, ref expr) => {
2036 self.with_item_rib(|this| {
2038 this.with_constant_rib(|this| {
2039 this.visit_expr(expr);
2044 ItemKind::Use(ref use_tree) => {
2047 span: use_tree.span,
2049 self.resolve_use_tree(item.id, use_tree, &path);
2052 ItemKind::ExternCrate(_) | ItemKind::MacroDef(..) | ItemKind::GlobalAsm(_) => {
2053 // do nothing, these are just around to be encoded
2056 ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"),
2060 fn resolve_use_tree(&mut self, id: NodeId, use_tree: &ast::UseTree, prefix: &Path) {
2061 match use_tree.kind {
2062 ast::UseTreeKind::Nested(ref items) => {
2064 segments: prefix.segments
2066 .chain(use_tree.prefix.segments.iter())
2069 span: prefix.span.to(use_tree.prefix.span),
2072 if items.len() == 0 {
2073 // Resolve prefix of an import with empty braces (issue #28388).
2074 self.smart_resolve_path(id, None, &path, PathSource::ImportPrefix);
2076 for &(ref tree, nested_id) in items {
2077 self.resolve_use_tree(nested_id, tree, &path);
2081 ast::UseTreeKind::Simple(_) => {},
2082 ast::UseTreeKind::Glob => {},
2086 fn with_type_parameter_rib<'b, F>(&'b mut self, type_parameters: TypeParameters<'a, 'b>, f: F)
2087 where F: FnOnce(&mut Resolver)
2089 match type_parameters {
2090 HasTypeParameters(generics, rib_kind) => {
2091 let mut function_type_rib = Rib::new(rib_kind);
2092 let mut seen_bindings = FxHashMap();
2093 for param in &generics.params {
2094 if let GenericParam::Type(ref type_parameter) = *param {
2095 let ident = type_parameter.ident.modern();
2096 debug!("with_type_parameter_rib: {}", type_parameter.id);
2098 if seen_bindings.contains_key(&ident) {
2099 let span = seen_bindings.get(&ident).unwrap();
2100 let err = ResolutionError::NameAlreadyUsedInTypeParameterList(
2104 resolve_error(self, type_parameter.span, err);
2106 seen_bindings.entry(ident).or_insert(type_parameter.span);
2108 // plain insert (no renaming)
2109 let def_id = self.definitions.local_def_id(type_parameter.id);
2110 let def = Def::TyParam(def_id);
2111 function_type_rib.bindings.insert(ident, def);
2112 self.record_def(type_parameter.id, PathResolution::new(def));
2115 self.ribs[TypeNS].push(function_type_rib);
2118 NoTypeParameters => {
2125 if let HasTypeParameters(..) = type_parameters {
2126 self.ribs[TypeNS].pop();
2130 fn with_label_rib<F>(&mut self, f: F)
2131 where F: FnOnce(&mut Resolver)
2133 self.label_ribs.push(Rib::new(NormalRibKind));
2135 self.label_ribs.pop();
2138 fn with_item_rib<F>(&mut self, f: F)
2139 where F: FnOnce(&mut Resolver)
2141 self.ribs[ValueNS].push(Rib::new(ItemRibKind));
2142 self.ribs[TypeNS].push(Rib::new(ItemRibKind));
2144 self.ribs[TypeNS].pop();
2145 self.ribs[ValueNS].pop();
2148 fn with_constant_rib<F>(&mut self, f: F)
2149 where F: FnOnce(&mut Resolver)
2151 self.ribs[ValueNS].push(Rib::new(ConstantItemRibKind));
2153 self.ribs[ValueNS].pop();
2156 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2157 where F: FnOnce(&mut Resolver) -> T
2159 // Handle nested impls (inside fn bodies)
2160 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2161 let result = f(self);
2162 self.current_self_type = previous_value;
2166 /// This is called to resolve a trait reference from an `impl` (i.e. `impl Trait for Foo`)
2167 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
2168 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2170 let mut new_val = None;
2171 let mut new_id = None;
2172 if let Some(trait_ref) = opt_trait_ref {
2173 let path: Vec<_> = trait_ref.path.segments.iter()
2174 .map(|seg| respan(seg.span, seg.identifier))
2176 let def = self.smart_resolve_path_fragment(
2180 trait_ref.path.span,
2181 trait_ref.path.segments.last().unwrap().span,
2182 PathSource::Trait(AliasPossibility::No)
2184 if def != Def::Err {
2185 new_id = Some(def.def_id());
2186 let span = trait_ref.path.span;
2187 if let PathResult::Module(module) = self.resolve_path(&path, None, false, span) {
2188 new_val = Some((module, trait_ref.clone()));
2192 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2193 let result = f(self, new_id);
2194 self.current_trait_ref = original_trait_ref;
2198 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2199 where F: FnOnce(&mut Resolver)
2201 let mut self_type_rib = Rib::new(NormalRibKind);
2203 // plain insert (no renaming, types are not currently hygienic....)
2204 self_type_rib.bindings.insert(keywords::SelfType.ident(), self_def);
2205 self.ribs[TypeNS].push(self_type_rib);
2207 self.ribs[TypeNS].pop();
2210 fn resolve_implementation(&mut self,
2211 generics: &Generics,
2212 opt_trait_reference: &Option<TraitRef>,
2215 impl_items: &[ImplItem]) {
2216 // If applicable, create a rib for the type parameters.
2217 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2218 // Dummy self type for better errors if `Self` is used in the trait path.
2219 this.with_self_rib(Def::SelfTy(None, None), |this| {
2220 // Resolve the trait reference, if necessary.
2221 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2222 let item_def_id = this.definitions.local_def_id(item_id);
2223 this.with_self_rib(Def::SelfTy(trait_id, Some(item_def_id)), |this| {
2224 if let Some(trait_ref) = opt_trait_reference.as_ref() {
2225 // Resolve type arguments in trait path
2226 visit::walk_trait_ref(this, trait_ref);
2228 // Resolve the self type.
2229 this.visit_ty(self_type);
2230 // Resolve the type parameters.
2231 this.visit_generics(generics);
2232 this.with_current_self_type(self_type, |this| {
2233 for impl_item in impl_items {
2234 this.check_proc_macro_attrs(&impl_item.attrs);
2235 this.resolve_visibility(&impl_item.vis);
2237 // We also need a new scope for the impl item type parameters.
2238 let type_parameters = HasTypeParameters(&impl_item.generics,
2239 TraitOrImplItemRibKind);
2240 this.with_type_parameter_rib(type_parameters, |this| {
2241 use self::ResolutionError::*;
2242 match impl_item.node {
2243 ImplItemKind::Const(..) => {
2244 // If this is a trait impl, ensure the const
2246 this.check_trait_item(impl_item.ident,
2249 |n, s| ConstNotMemberOfTrait(n, s));
2250 this.with_constant_rib(|this|
2251 visit::walk_impl_item(this, impl_item)
2254 ImplItemKind::Method(_, _) => {
2255 // If this is a trait impl, ensure the method
2257 this.check_trait_item(impl_item.ident,
2260 |n, s| MethodNotMemberOfTrait(n, s));
2262 visit::walk_impl_item(this, impl_item);
2264 ImplItemKind::Type(ref ty) => {
2265 // If this is a trait impl, ensure the type
2267 this.check_trait_item(impl_item.ident,
2270 |n, s| TypeNotMemberOfTrait(n, s));
2274 ImplItemKind::Macro(_) =>
2275 panic!("unexpanded macro in resolve!"),
2286 fn check_trait_item<F>(&mut self, ident: Ident, ns: Namespace, span: Span, err: F)
2287 where F: FnOnce(Name, &str) -> ResolutionError
2289 // If there is a TraitRef in scope for an impl, then the method must be in the
2291 if let Some((module, _)) = self.current_trait_ref {
2292 if self.resolve_ident_in_module(module, ident, ns, false, false, span).is_err() {
2293 let path = &self.current_trait_ref.as_ref().unwrap().1.path;
2294 resolve_error(self, span, err(ident.name, &path_names_to_string(path)));
2299 fn resolve_local(&mut self, local: &Local) {
2300 // Resolve the type.
2301 walk_list!(self, visit_ty, &local.ty);
2303 // Resolve the initializer.
2304 walk_list!(self, visit_expr, &local.init);
2306 // Resolve the pattern.
2307 self.resolve_pattern(&local.pat, PatternSource::Let, &mut FxHashMap());
2310 // build a map from pattern identifiers to binding-info's.
2311 // this is done hygienically. This could arise for a macro
2312 // that expands into an or-pattern where one 'x' was from the
2313 // user and one 'x' came from the macro.
2314 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2315 let mut binding_map = FxHashMap();
2317 pat.walk(&mut |pat| {
2318 if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node {
2319 if sub_pat.is_some() || match self.def_map.get(&pat.id).map(|res| res.base_def()) {
2320 Some(Def::Local(..)) => true,
2323 let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode };
2324 binding_map.insert(ident.node, binding_info);
2333 // check that all of the arms in an or-pattern have exactly the
2334 // same set of bindings, with the same binding modes for each.
2335 fn check_consistent_bindings(&mut self, pats: &[P<Pat>]) {
2336 if pats.is_empty() {
2340 let mut missing_vars = FxHashMap();
2341 let mut inconsistent_vars = FxHashMap();
2342 for (i, p) in pats.iter().enumerate() {
2343 let map_i = self.binding_mode_map(&p);
2345 for (j, q) in pats.iter().enumerate() {
2350 let map_j = self.binding_mode_map(&q);
2351 for (&key, &binding_i) in &map_i {
2352 if map_j.len() == 0 { // Account for missing bindings when
2353 let binding_error = missing_vars // map_j has none.
2355 .or_insert(BindingError {
2357 origin: BTreeSet::new(),
2358 target: BTreeSet::new(),
2360 binding_error.origin.insert(binding_i.span);
2361 binding_error.target.insert(q.span);
2363 for (&key_j, &binding_j) in &map_j {
2364 match map_i.get(&key_j) {
2365 None => { // missing binding
2366 let binding_error = missing_vars
2368 .or_insert(BindingError {
2370 origin: BTreeSet::new(),
2371 target: BTreeSet::new(),
2373 binding_error.origin.insert(binding_j.span);
2374 binding_error.target.insert(p.span);
2376 Some(binding_i) => { // check consistent binding
2377 if binding_i.binding_mode != binding_j.binding_mode {
2380 .or_insert((binding_j.span, binding_i.span));
2388 let mut missing_vars = missing_vars.iter().collect::<Vec<_>>();
2389 missing_vars.sort();
2390 for (_, v) in missing_vars {
2392 *v.origin.iter().next().unwrap(),
2393 ResolutionError::VariableNotBoundInPattern(v));
2395 let mut inconsistent_vars = inconsistent_vars.iter().collect::<Vec<_>>();
2396 inconsistent_vars.sort();
2397 for (name, v) in inconsistent_vars {
2398 resolve_error(self, v.0, ResolutionError::VariableBoundWithDifferentMode(*name, v.1));
2402 fn resolve_arm(&mut self, arm: &Arm) {
2403 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2405 let mut bindings_list = FxHashMap();
2406 for pattern in &arm.pats {
2407 self.resolve_pattern(&pattern, PatternSource::Match, &mut bindings_list);
2410 // This has to happen *after* we determine which pat_idents are variants
2411 self.check_consistent_bindings(&arm.pats);
2413 walk_list!(self, visit_expr, &arm.guard);
2414 self.visit_expr(&arm.body);
2416 self.ribs[ValueNS].pop();
2419 fn resolve_block(&mut self, block: &Block) {
2420 debug!("(resolving block) entering block");
2421 // Move down in the graph, if there's an anonymous module rooted here.
2422 let orig_module = self.current_module;
2423 let anonymous_module = self.block_map.get(&block.id).cloned(); // clones a reference
2425 let mut num_macro_definition_ribs = 0;
2426 if let Some(anonymous_module) = anonymous_module {
2427 debug!("(resolving block) found anonymous module, moving down");
2428 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2429 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2430 self.current_module = anonymous_module;
2431 self.finalize_current_module_macro_resolutions();
2433 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2436 // Descend into the block.
2437 for stmt in &block.stmts {
2438 if let ast::StmtKind::Item(ref item) = stmt.node {
2439 if let ast::ItemKind::MacroDef(..) = item.node {
2440 num_macro_definition_ribs += 1;
2441 let def = self.definitions.local_def_id(item.id);
2442 self.ribs[ValueNS].push(Rib::new(MacroDefinition(def)));
2443 self.label_ribs.push(Rib::new(MacroDefinition(def)));
2447 self.visit_stmt(stmt);
2451 self.current_module = orig_module;
2452 for _ in 0 .. num_macro_definition_ribs {
2453 self.ribs[ValueNS].pop();
2454 self.label_ribs.pop();
2456 self.ribs[ValueNS].pop();
2457 if let Some(_) = anonymous_module {
2458 self.ribs[TypeNS].pop();
2460 debug!("(resolving block) leaving block");
2463 fn fresh_binding(&mut self,
2464 ident: &SpannedIdent,
2466 outer_pat_id: NodeId,
2467 pat_src: PatternSource,
2468 bindings: &mut FxHashMap<Ident, NodeId>)
2470 // Add the binding to the local ribs, if it
2471 // doesn't already exist in the bindings map. (We
2472 // must not add it if it's in the bindings map
2473 // because that breaks the assumptions later
2474 // passes make about or-patterns.)
2475 let mut def = Def::Local(pat_id);
2476 match bindings.get(&ident.node).cloned() {
2477 Some(id) if id == outer_pat_id => {
2478 // `Variant(a, a)`, error
2482 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2483 &ident.node.name.as_str())
2486 Some(..) if pat_src == PatternSource::FnParam => {
2487 // `fn f(a: u8, a: u8)`, error
2491 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2492 &ident.node.name.as_str())
2495 Some(..) if pat_src == PatternSource::Match ||
2496 pat_src == PatternSource::IfLet ||
2497 pat_src == PatternSource::WhileLet => {
2498 // `Variant1(a) | Variant2(a)`, ok
2499 // Reuse definition from the first `a`.
2500 def = self.ribs[ValueNS].last_mut().unwrap().bindings[&ident.node];
2503 span_bug!(ident.span, "two bindings with the same name from \
2504 unexpected pattern source {:?}", pat_src);
2507 // A completely fresh binding, add to the lists if it's valid.
2508 if ident.node.name != keywords::Invalid.name() {
2509 bindings.insert(ident.node, outer_pat_id);
2510 self.ribs[ValueNS].last_mut().unwrap().bindings.insert(ident.node, def);
2515 PathResolution::new(def)
2518 fn resolve_pattern(&mut self,
2520 pat_src: PatternSource,
2521 // Maps idents to the node ID for the
2522 // outermost pattern that binds them.
2523 bindings: &mut FxHashMap<Ident, NodeId>) {
2524 // Visit all direct subpatterns of this pattern.
2525 let outer_pat_id = pat.id;
2526 pat.walk(&mut |pat| {
2528 PatKind::Ident(bmode, ref ident, ref opt_pat) => {
2529 // First try to resolve the identifier as some existing
2530 // entity, then fall back to a fresh binding.
2531 let binding = self.resolve_ident_in_lexical_scope(ident.node, ValueNS,
2533 .and_then(LexicalScopeBinding::item);
2534 let resolution = binding.map(NameBinding::def).and_then(|def| {
2535 let is_syntactic_ambiguity = opt_pat.is_none() &&
2536 bmode == BindingMode::ByValue(Mutability::Immutable);
2538 Def::StructCtor(_, CtorKind::Const) |
2539 Def::VariantCtor(_, CtorKind::Const) |
2540 Def::Const(..) if is_syntactic_ambiguity => {
2541 // Disambiguate in favor of a unit struct/variant
2542 // or constant pattern.
2543 self.record_use(ident.node, ValueNS, binding.unwrap(), ident.span);
2544 Some(PathResolution::new(def))
2546 Def::StructCtor(..) | Def::VariantCtor(..) |
2547 Def::Const(..) | Def::Static(..) => {
2548 // This is unambiguously a fresh binding, either syntactically
2549 // (e.g. `IDENT @ PAT` or `ref IDENT`) or because `IDENT` resolves
2550 // to something unusable as a pattern (e.g. constructor function),
2551 // but we still conservatively report an error, see
2552 // issues/33118#issuecomment-233962221 for one reason why.
2556 ResolutionError::BindingShadowsSomethingUnacceptable(
2557 pat_src.descr(), ident.node.name, binding.unwrap())
2561 Def::Fn(..) | Def::Err => {
2562 // These entities are explicitly allowed
2563 // to be shadowed by fresh bindings.
2567 span_bug!(ident.span, "unexpected definition for an \
2568 identifier in pattern: {:?}", def);
2571 }).unwrap_or_else(|| {
2572 self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings)
2575 self.record_def(pat.id, resolution);
2578 PatKind::TupleStruct(ref path, ..) => {
2579 self.smart_resolve_path(pat.id, None, path, PathSource::TupleStruct);
2582 PatKind::Path(ref qself, ref path) => {
2583 self.smart_resolve_path(pat.id, qself.as_ref(), path, PathSource::Pat);
2586 PatKind::Struct(ref path, ..) => {
2587 self.smart_resolve_path(pat.id, None, path, PathSource::Struct);
2595 visit::walk_pat(self, pat);
2598 // High-level and context dependent path resolution routine.
2599 // Resolves the path and records the resolution into definition map.
2600 // If resolution fails tries several techniques to find likely
2601 // resolution candidates, suggest imports or other help, and report
2602 // errors in user friendly way.
2603 fn smart_resolve_path(&mut self,
2605 qself: Option<&QSelf>,
2609 let segments = &path.segments.iter()
2610 .map(|seg| respan(seg.span, seg.identifier))
2611 .collect::<Vec<_>>();
2612 let ident_span = path.segments.last().map_or(path.span, |seg| seg.span);
2613 self.smart_resolve_path_fragment(id, qself, segments, path.span, ident_span, source)
2616 fn smart_resolve_path_fragment(&mut self,
2618 qself: Option<&QSelf>,
2619 path: &[SpannedIdent],
2624 let ns = source.namespace();
2625 let is_expected = &|def| source.is_expected(def);
2626 let is_enum_variant = &|def| if let Def::Variant(..) = def { true } else { false };
2628 // Base error is amended with one short label and possibly some longer helps/notes.
2629 let report_errors = |this: &mut Self, def: Option<Def>| {
2630 // Make the base error.
2631 let expected = source.descr_expected();
2632 let path_str = names_to_string(path);
2633 let code = source.error_code(def.is_some());
2634 let (base_msg, fallback_label, base_span) = if let Some(def) = def {
2635 (format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str),
2636 format!("not a {}", expected),
2639 let item_str = path[path.len() - 1].node;
2640 let item_span = path[path.len() - 1].span;
2641 let (mod_prefix, mod_str) = if path.len() == 1 {
2642 (format!(""), format!("this scope"))
2643 } else if path.len() == 2 && path[0].node.name == keywords::CrateRoot.name() {
2644 (format!(""), format!("the crate root"))
2646 let mod_path = &path[..path.len() - 1];
2647 let mod_prefix = match this.resolve_path(mod_path, Some(TypeNS), false, span) {
2648 PathResult::Module(module) => module.def(),
2650 }.map_or(format!(""), |def| format!("{} ", def.kind_name()));
2651 (mod_prefix, format!("`{}`", names_to_string(mod_path)))
2653 (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str),
2654 format!("not found in {}", mod_str),
2657 let code = DiagnosticId::Error(code.into());
2658 let mut err = this.session.struct_span_err_with_code(base_span, &base_msg, code);
2660 // Emit special messages for unresolved `Self` and `self`.
2661 if is_self_type(path, ns) {
2662 __diagnostic_used!(E0411);
2663 err.code(DiagnosticId::Error("E0411".into()));
2664 err.span_label(span, "`Self` is only available in traits and impls");
2665 return (err, Vec::new());
2667 if is_self_value(path, ns) {
2668 __diagnostic_used!(E0424);
2669 err.code(DiagnosticId::Error("E0424".into()));
2670 err.span_label(span, format!("`self` value is only available in \
2671 methods with `self` parameter"));
2672 return (err, Vec::new());
2675 // Try to lookup the name in more relaxed fashion for better error reporting.
2676 let ident = *path.last().unwrap();
2677 let candidates = this.lookup_import_candidates(ident.node.name, ns, is_expected);
2678 if candidates.is_empty() && is_expected(Def::Enum(DefId::local(CRATE_DEF_INDEX))) {
2679 let enum_candidates =
2680 this.lookup_import_candidates(ident.node.name, ns, is_enum_variant);
2681 let mut enum_candidates = enum_candidates.iter()
2682 .map(|suggestion| import_candidate_to_paths(&suggestion)).collect::<Vec<_>>();
2683 enum_candidates.sort();
2684 for (sp, variant_path, enum_path) in enum_candidates {
2686 let msg = format!("there is an enum variant `{}`, \
2692 err.span_suggestion(span, "you can try using the variant's enum",
2697 if path.len() == 1 && this.self_type_is_available(span) {
2698 if let Some(candidate) = this.lookup_assoc_candidate(ident.node, ns, is_expected) {
2699 let self_is_available = this.self_value_is_available(path[0].node.ctxt, span);
2701 AssocSuggestion::Field => {
2702 err.span_suggestion(span, "try",
2703 format!("self.{}", path_str));
2704 if !self_is_available {
2705 err.span_label(span, format!("`self` value is only available in \
2706 methods with `self` parameter"));
2709 AssocSuggestion::MethodWithSelf if self_is_available => {
2710 err.span_suggestion(span, "try",
2711 format!("self.{}", path_str));
2713 AssocSuggestion::MethodWithSelf | AssocSuggestion::AssocItem => {
2714 err.span_suggestion(span, "try",
2715 format!("Self::{}", path_str));
2718 return (err, candidates);
2722 let mut levenshtein_worked = false;
2725 if let Some(candidate) = this.lookup_typo_candidate(path, ns, is_expected, span) {
2726 err.span_label(ident_span, format!("did you mean `{}`?", candidate));
2727 levenshtein_worked = true;
2730 // Try context dependent help if relaxed lookup didn't work.
2731 if let Some(def) = def {
2732 match (def, source) {
2733 (Def::Macro(..), _) => {
2734 err.span_label(span, format!("did you mean `{}!(...)`?", path_str));
2735 return (err, candidates);
2737 (Def::TyAlias(..), PathSource::Trait(_)) => {
2738 err.span_label(span, "type aliases cannot be used for traits");
2739 return (err, candidates);
2741 (Def::Mod(..), PathSource::Expr(Some(parent))) => match parent.node {
2742 ExprKind::Field(_, ident) => {
2743 err.span_label(parent.span, format!("did you mean `{}::{}`?",
2744 path_str, ident.node));
2745 return (err, candidates);
2747 ExprKind::MethodCall(ref segment, ..) => {
2748 err.span_label(parent.span, format!("did you mean `{}::{}(...)`?",
2749 path_str, segment.identifier));
2750 return (err, candidates);
2754 (Def::Enum(..), PathSource::TupleStruct)
2755 | (Def::Enum(..), PathSource::Expr(..)) => {
2756 if let Some(variants) = this.collect_enum_variants(def) {
2757 err.note(&format!("did you mean to use one \
2758 of the following variants?\n{}",
2760 .map(|suggestion| path_names_to_string(suggestion))
2761 .map(|suggestion| format!("- `{}`", suggestion))
2762 .collect::<Vec<_>>()
2766 err.note("did you mean to use one of the enum's variants?");
2768 return (err, candidates);
2770 (Def::Struct(def_id), _) if ns == ValueNS => {
2771 if let Some((ctor_def, ctor_vis))
2772 = this.struct_constructors.get(&def_id).cloned() {
2773 let accessible_ctor = this.is_accessible(ctor_vis);
2774 if is_expected(ctor_def) && !accessible_ctor {
2775 err.span_label(span, format!("constructor is not visible \
2776 here due to private fields"));
2779 err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?",
2782 return (err, candidates);
2784 (Def::Union(..), _) |
2785 (Def::Variant(..), _) |
2786 (Def::VariantCtor(_, CtorKind::Fictive), _) if ns == ValueNS => {
2787 err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?",
2789 return (err, candidates);
2791 (Def::SelfTy(..), _) if ns == ValueNS => {
2792 err.span_label(span, fallback_label);
2793 err.note("can't use `Self` as a constructor, you must use the \
2794 implemented struct");
2795 return (err, candidates);
2797 (Def::TyAlias(_), _) | (Def::AssociatedTy(..), _) if ns == ValueNS => {
2798 err.note("can't use a type alias as a constructor");
2799 return (err, candidates);
2806 if !levenshtein_worked {
2807 err.span_label(base_span, fallback_label);
2808 this.type_ascription_suggestion(&mut err, base_span);
2812 let report_errors = |this: &mut Self, def: Option<Def>| {
2813 let (err, candidates) = report_errors(this, def);
2814 let def_id = this.current_module.normal_ancestor_id;
2815 let node_id = this.definitions.as_local_node_id(def_id).unwrap();
2816 let better = def.is_some();
2817 this.use_injections.push(UseError { err, candidates, node_id, better });
2818 err_path_resolution()
2821 let resolution = match self.resolve_qpath_anywhere(id, qself, path, ns, span,
2822 source.defer_to_typeck(),
2823 source.global_by_default()) {
2824 Some(resolution) if resolution.unresolved_segments() == 0 => {
2825 if is_expected(resolution.base_def()) || resolution.base_def() == Def::Err {
2828 // Add a temporary hack to smooth the transition to new struct ctor
2829 // visibility rules. See #38932 for more details.
2831 if let Def::Struct(def_id) = resolution.base_def() {
2832 if let Some((ctor_def, ctor_vis))
2833 = self.struct_constructors.get(&def_id).cloned() {
2834 if is_expected(ctor_def) && self.is_accessible(ctor_vis) {
2835 let lint = lint::builtin::LEGACY_CONSTRUCTOR_VISIBILITY;
2836 self.session.buffer_lint(lint, id, span,
2837 "private struct constructors are not usable through \
2838 re-exports in outer modules",
2840 res = Some(PathResolution::new(ctor_def));
2845 res.unwrap_or_else(|| report_errors(self, Some(resolution.base_def())))
2848 Some(resolution) if source.defer_to_typeck() => {
2849 // Not fully resolved associated item `T::A::B` or `<T as Tr>::A::B`
2850 // or `<T>::A::B`. If `B` should be resolved in value namespace then
2851 // it needs to be added to the trait map.
2853 let item_name = path.last().unwrap().node;
2854 let traits = self.get_traits_containing_item(item_name, ns);
2855 self.trait_map.insert(id, traits);
2859 _ => report_errors(self, None)
2862 if let PathSource::TraitItem(..) = source {} else {
2863 // Avoid recording definition of `A::B` in `<T as A>::B::C`.
2864 self.record_def(id, resolution);
2869 fn type_ascription_suggestion(&self,
2870 err: &mut DiagnosticBuilder,
2872 debug!("type_ascription_suggetion {:?}", base_span);
2873 let cm = self.session.codemap();
2874 debug!("self.current_type_ascription {:?}", self.current_type_ascription);
2875 if let Some(sp) = self.current_type_ascription.last() {
2877 loop { // try to find the `:`, bail on first non-':'/non-whitespace
2878 sp = cm.next_point(sp);
2879 if let Ok(snippet) = cm.span_to_snippet(sp.to(cm.next_point(sp))) {
2880 debug!("snippet {:?}", snippet);
2881 let line_sp = cm.lookup_char_pos(sp.hi()).line;
2882 let line_base_sp = cm.lookup_char_pos(base_span.lo()).line;
2883 debug!("{:?} {:?}", line_sp, line_base_sp);
2885 err.span_label(base_span,
2886 "expecting a type here because of type ascription");
2887 if line_sp != line_base_sp {
2888 err.span_suggestion_short(sp,
2889 "did you mean to use `;` here instead?",
2893 } else if snippet.trim().len() != 0 {
2894 debug!("tried to find type ascription `:` token, couldn't find it");
2904 fn self_type_is_available(&mut self, span: Span) -> bool {
2905 let binding = self.resolve_ident_in_lexical_scope(keywords::SelfType.ident(),
2906 TypeNS, false, span);
2907 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
2910 fn self_value_is_available(&mut self, ctxt: SyntaxContext, span: Span) -> bool {
2911 let ident = Ident { name: keywords::SelfValue.name(), ctxt: ctxt };
2912 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, false, span);
2913 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
2916 // Resolve in alternative namespaces if resolution in the primary namespace fails.
2917 fn resolve_qpath_anywhere(&mut self,
2919 qself: Option<&QSelf>,
2920 path: &[SpannedIdent],
2921 primary_ns: Namespace,
2923 defer_to_typeck: bool,
2924 global_by_default: bool)
2925 -> Option<PathResolution> {
2926 let mut fin_res = None;
2927 // FIXME: can't resolve paths in macro namespace yet, macros are
2928 // processed by the little special hack below.
2929 for (i, ns) in [primary_ns, TypeNS, ValueNS, /*MacroNS*/].iter().cloned().enumerate() {
2930 if i == 0 || ns != primary_ns {
2931 match self.resolve_qpath(id, qself, path, ns, span, global_by_default) {
2932 // If defer_to_typeck, then resolution > no resolution,
2933 // otherwise full resolution > partial resolution > no resolution.
2934 Some(res) if res.unresolved_segments() == 0 || defer_to_typeck =>
2936 res => if fin_res.is_none() { fin_res = res },
2940 let is_global = self.global_macros.get(&path[0].node.name).cloned()
2941 .map(|binding| binding.get_macro(self).kind() == MacroKind::Bang).unwrap_or(false);
2942 if primary_ns != MacroNS && (is_global ||
2943 self.macro_names.contains(&path[0].node.modern())) {
2944 // Return some dummy definition, it's enough for error reporting.
2946 PathResolution::new(Def::Macro(DefId::local(CRATE_DEF_INDEX), MacroKind::Bang))
2952 /// Handles paths that may refer to associated items.
2953 fn resolve_qpath(&mut self,
2955 qself: Option<&QSelf>,
2956 path: &[SpannedIdent],
2959 global_by_default: bool)
2960 -> Option<PathResolution> {
2961 if let Some(qself) = qself {
2962 if qself.position == 0 {
2963 // FIXME: Create some fake resolution that can't possibly be a type.
2964 return Some(PathResolution::with_unresolved_segments(
2965 Def::Mod(DefId::local(CRATE_DEF_INDEX)), path.len()
2968 // Make sure `A::B` in `<T as A>::B::C` is a trait item.
2969 let ns = if qself.position + 1 == path.len() { ns } else { TypeNS };
2970 let res = self.smart_resolve_path_fragment(id, None, &path[..qself.position + 1],
2971 span, span, PathSource::TraitItem(ns));
2972 return Some(PathResolution::with_unresolved_segments(
2973 res.base_def(), res.unresolved_segments() + path.len() - qself.position - 1
2977 let result = match self.resolve_path(&path, Some(ns), true, span) {
2978 PathResult::NonModule(path_res) => path_res,
2979 PathResult::Module(module) if !module.is_normal() => {
2980 PathResolution::new(module.def().unwrap())
2982 // In `a(::assoc_item)*` `a` cannot be a module. If `a` does resolve to a module we
2983 // don't report an error right away, but try to fallback to a primitive type.
2984 // So, we are still able to successfully resolve something like
2986 // use std::u8; // bring module u8 in scope
2987 // fn f() -> u8 { // OK, resolves to primitive u8, not to std::u8
2988 // u8::max_value() // OK, resolves to associated function <u8>::max_value,
2989 // // not to non-existent std::u8::max_value
2992 // Such behavior is required for backward compatibility.
2993 // The same fallback is used when `a` resolves to nothing.
2994 PathResult::Module(..) | PathResult::Failed(..)
2995 if (ns == TypeNS || path.len() > 1) &&
2996 self.primitive_type_table.primitive_types
2997 .contains_key(&path[0].node.name) => {
2998 let prim = self.primitive_type_table.primitive_types[&path[0].node.name];
3000 TyUint(UintTy::U128) | TyInt(IntTy::I128) => {
3001 if !self.session.features_untracked().i128_type {
3002 emit_feature_err(&self.session.parse_sess,
3003 "i128_type", span, GateIssue::Language,
3004 "128-bit type is unstable");
3010 PathResolution::with_unresolved_segments(Def::PrimTy(prim), path.len() - 1)
3012 PathResult::Module(module) => PathResolution::new(module.def().unwrap()),
3013 PathResult::Failed(span, msg, false) => {
3014 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
3015 err_path_resolution()
3017 PathResult::Failed(..) => return None,
3018 PathResult::Indeterminate => bug!("indetermined path result in resolve_qpath"),
3021 if path.len() > 1 && !global_by_default && result.base_def() != Def::Err &&
3022 path[0].node.name != keywords::CrateRoot.name() &&
3023 path[0].node.name != keywords::DollarCrate.name() {
3024 let unqualified_result = {
3025 match self.resolve_path(&[*path.last().unwrap()], Some(ns), false, span) {
3026 PathResult::NonModule(path_res) => path_res.base_def(),
3027 PathResult::Module(module) => module.def().unwrap(),
3028 _ => return Some(result),
3031 if result.base_def() == unqualified_result {
3032 let lint = lint::builtin::UNUSED_QUALIFICATIONS;
3033 self.session.buffer_lint(lint, id, span, "unnecessary qualification")
3040 fn resolve_path(&mut self,
3041 path: &[SpannedIdent],
3042 opt_ns: Option<Namespace>, // `None` indicates a module path
3046 let mut module = None;
3047 let mut allow_super = true;
3049 for (i, &ident) in path.iter().enumerate() {
3050 debug!("resolve_path ident {} {:?}", i, ident);
3051 let is_last = i == path.len() - 1;
3052 let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
3053 let name = ident.node.name;
3055 if i == 0 && ns == TypeNS && name == keywords::SelfValue.name() {
3056 let mut ctxt = ident.node.ctxt.modern();
3057 module = Some(self.resolve_self(&mut ctxt, self.current_module));
3059 } else if allow_super && ns == TypeNS && name == keywords::Super.name() {
3060 let mut ctxt = ident.node.ctxt.modern();
3061 let self_module = match i {
3062 0 => self.resolve_self(&mut ctxt, self.current_module),
3063 _ => module.unwrap(),
3065 if let Some(parent) = self_module.parent {
3066 module = Some(self.resolve_self(&mut ctxt, parent));
3069 let msg = "There are too many initial `super`s.".to_string();
3070 return PathResult::Failed(ident.span, msg, false);
3072 } else if i == 0 && ns == TypeNS && name == keywords::Extern.name() {
3075 allow_super = false;
3078 if (i == 0 && name == keywords::CrateRoot.name()) ||
3079 (i == 1 && name == keywords::Crate.name() &&
3080 path[0].node.name == keywords::CrateRoot.name()) {
3081 // `::a::b` or `::crate::a::b`
3082 module = Some(self.resolve_crate_root(ident.node.ctxt, false));
3084 } else if i == 0 && name == keywords::DollarCrate.name() {
3086 module = Some(self.resolve_crate_root(ident.node.ctxt, true));
3088 } else if i == 1 && !token::Ident(ident.node).is_path_segment_keyword() {
3089 let prev_name = path[0].node.name;
3090 if prev_name == keywords::Extern.name() ||
3091 prev_name == keywords::CrateRoot.name() &&
3092 self.session.features_untracked().extern_absolute_paths {
3093 // `::extern_crate::a::b`
3094 let crate_id = self.crate_loader.resolve_crate_from_path(name, ident.span);
3096 self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
3097 self.populate_module_if_necessary(crate_root);
3098 module = Some(crate_root);
3104 // Report special messages for path segment keywords in wrong positions.
3105 if name == keywords::CrateRoot.name() && i != 0 ||
3106 name == keywords::DollarCrate.name() && i != 0 ||
3107 name == keywords::SelfValue.name() && i != 0 ||
3108 name == keywords::SelfType.name() && i != 0 ||
3109 name == keywords::Super.name() && i != 0 ||
3110 name == keywords::Extern.name() && i != 0 ||
3111 name == keywords::Crate.name() && i != 1 &&
3112 path[0].node.name != keywords::CrateRoot.name() {
3113 let name_str = if name == keywords::CrateRoot.name() {
3114 format!("crate root")
3116 format!("`{}`", name)
3118 let msg = if i == 1 && path[0].node.name == keywords::CrateRoot.name() {
3119 format!("global paths cannot start with {}", name_str)
3120 } else if i == 0 && name == keywords::Crate.name() {
3121 format!("{} can only be used in absolute paths", name_str)
3123 format!("{} in paths can only be used in start position", name_str)
3125 return PathResult::Failed(ident.span, msg, false);
3128 let binding = if let Some(module) = module {
3129 self.resolve_ident_in_module(module, ident.node, ns, false, record_used, path_span)
3130 } else if opt_ns == Some(MacroNS) {
3131 self.resolve_lexical_macro_path_segment(ident.node, ns, record_used, path_span)
3132 .map(MacroBinding::binding)
3134 match self.resolve_ident_in_lexical_scope(ident.node, ns, record_used, path_span) {
3135 Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
3136 Some(LexicalScopeBinding::Def(def))
3137 if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) => {
3138 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3142 _ => Err(if record_used { Determined } else { Undetermined }),
3148 let def = binding.def();
3149 let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(def);
3150 if let Some(next_module) = binding.module() {
3151 module = Some(next_module);
3152 } else if def == Def::Err {
3153 return PathResult::NonModule(err_path_resolution());
3154 } else if opt_ns.is_some() && (is_last || maybe_assoc) {
3155 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3156 def, path.len() - i - 1
3159 return PathResult::Failed(ident.span,
3160 format!("Not a module `{}`", ident.node),
3164 Err(Undetermined) => return PathResult::Indeterminate,
3165 Err(Determined) => {
3166 if let Some(module) = module {
3167 if opt_ns.is_some() && !module.is_normal() {
3168 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3169 module.def().unwrap(), path.len() - i
3173 let msg = if module.and_then(ModuleData::def) == self.graph_root.def() {
3174 let is_mod = |def| match def { Def::Mod(..) => true, _ => false };
3175 let mut candidates =
3176 self.lookup_import_candidates(name, TypeNS, is_mod);
3177 candidates.sort_by_key(|c| (c.path.segments.len(), c.path.to_string()));
3178 if let Some(candidate) = candidates.get(0) {
3179 format!("Did you mean `{}`?", candidate.path)
3181 format!("Maybe a missing `extern crate {};`?", ident.node)
3184 format!("Use of undeclared type or module `{}`", ident.node)
3186 format!("Could not find `{}` in `{}`", ident.node, path[i - 1].node)
3188 return PathResult::Failed(ident.span, msg, is_last);
3193 PathResult::Module(module.unwrap_or(self.graph_root))
3196 // Resolve a local definition, potentially adjusting for closures.
3197 fn adjust_local_def(&mut self,
3202 span: Span) -> Def {
3203 let ribs = &self.ribs[ns][rib_index + 1..];
3205 // An invalid forward use of a type parameter from a previous default.
3206 if let ForwardTyParamBanRibKind = self.ribs[ns][rib_index].kind {
3208 resolve_error(self, span, ResolutionError::ForwardDeclaredTyParam);
3210 assert_eq!(def, Def::Err);
3216 span_bug!(span, "unexpected {:?} in bindings", def)
3218 Def::Local(node_id) => {
3221 NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) |
3222 ForwardTyParamBanRibKind => {
3223 // Nothing to do. Continue.
3225 ClosureRibKind(function_id) => {
3228 let seen = self.freevars_seen
3230 .or_insert_with(|| NodeMap());
3231 if let Some(&index) = seen.get(&node_id) {
3232 def = Def::Upvar(node_id, index, function_id);
3235 let vec = self.freevars
3237 .or_insert_with(|| vec![]);
3238 let depth = vec.len();
3239 def = Def::Upvar(node_id, depth, function_id);
3246 seen.insert(node_id, depth);
3249 ItemRibKind | TraitOrImplItemRibKind => {
3250 // This was an attempt to access an upvar inside a
3251 // named function item. This is not allowed, so we
3254 resolve_error(self, span,
3255 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
3259 ConstantItemRibKind => {
3260 // Still doesn't deal with upvars
3262 resolve_error(self, span,
3263 ResolutionError::AttemptToUseNonConstantValueInConstant);
3270 Def::TyParam(..) | Def::SelfTy(..) => {
3273 NormalRibKind | TraitOrImplItemRibKind | ClosureRibKind(..) |
3274 ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind |
3275 ConstantItemRibKind => {
3276 // Nothing to do. Continue.
3279 // This was an attempt to use a type parameter outside
3282 resolve_error(self, span,
3283 ResolutionError::TypeParametersFromOuterFunction);
3295 fn lookup_assoc_candidate<FilterFn>(&mut self,
3298 filter_fn: FilterFn)
3299 -> Option<AssocSuggestion>
3300 where FilterFn: Fn(Def) -> bool
3302 fn extract_node_id(t: &Ty) -> Option<NodeId> {
3304 TyKind::Path(None, _) => Some(t.id),
3305 TyKind::Rptr(_, ref mut_ty) => extract_node_id(&mut_ty.ty),
3306 // This doesn't handle the remaining `Ty` variants as they are not
3307 // that commonly the self_type, it might be interesting to provide
3308 // support for those in future.
3313 // Fields are generally expected in the same contexts as locals.
3314 if filter_fn(Def::Local(ast::DUMMY_NODE_ID)) {
3315 if let Some(node_id) = self.current_self_type.as_ref().and_then(extract_node_id) {
3316 // Look for a field with the same name in the current self_type.
3317 if let Some(resolution) = self.def_map.get(&node_id) {
3318 match resolution.base_def() {
3319 Def::Struct(did) | Def::Union(did)
3320 if resolution.unresolved_segments() == 0 => {
3321 if let Some(field_names) = self.field_names.get(&did) {
3322 if field_names.iter().any(|&field_name| ident.name == field_name) {
3323 return Some(AssocSuggestion::Field);
3333 // Look for associated items in the current trait.
3334 if let Some((module, _)) = self.current_trait_ref {
3335 if let Ok(binding) =
3336 self.resolve_ident_in_module(module, ident, ns, false, false, module.span) {
3337 let def = binding.def();
3339 return Some(if self.has_self.contains(&def.def_id()) {
3340 AssocSuggestion::MethodWithSelf
3342 AssocSuggestion::AssocItem
3351 fn lookup_typo_candidate<FilterFn>(&mut self,
3352 path: &[SpannedIdent],
3354 filter_fn: FilterFn,
3357 where FilterFn: Fn(Def) -> bool
3359 let add_module_candidates = |module: Module, names: &mut Vec<Name>| {
3360 for (&(ident, _), resolution) in module.resolutions.borrow().iter() {
3361 if let Some(binding) = resolution.borrow().binding {
3362 if filter_fn(binding.def()) {
3363 names.push(ident.name);
3369 let mut names = Vec::new();
3370 if path.len() == 1 {
3371 // Search in lexical scope.
3372 // Walk backwards up the ribs in scope and collect candidates.
3373 for rib in self.ribs[ns].iter().rev() {
3374 // Locals and type parameters
3375 for (ident, def) in &rib.bindings {
3376 if filter_fn(*def) {
3377 names.push(ident.name);
3381 if let ModuleRibKind(module) = rib.kind {
3382 // Items from this module
3383 add_module_candidates(module, &mut names);
3385 if let ModuleKind::Block(..) = module.kind {
3386 // We can see through blocks
3388 // Items from the prelude
3389 if let Some(prelude) = self.prelude {
3390 if !module.no_implicit_prelude {
3391 add_module_candidates(prelude, &mut names);
3398 // Add primitive types to the mix
3399 if filter_fn(Def::PrimTy(TyBool)) {
3400 for (name, _) in &self.primitive_type_table.primitive_types {
3405 // Search in module.
3406 let mod_path = &path[..path.len() - 1];
3407 if let PathResult::Module(module) = self.resolve_path(mod_path, Some(TypeNS),
3409 add_module_candidates(module, &mut names);
3413 let name = path[path.len() - 1].node.name;
3414 // Make sure error reporting is deterministic.
3415 names.sort_by_key(|name| name.as_str());
3416 match find_best_match_for_name(names.iter(), &name.as_str(), None) {
3417 Some(found) if found != name => Some(found),
3422 fn with_resolved_label<F>(&mut self, label: Option<Label>, id: NodeId, f: F)
3423 where F: FnOnce(&mut Resolver)
3425 if let Some(label) = label {
3426 let def = Def::Label(id);
3427 self.with_label_rib(|this| {
3428 this.label_ribs.last_mut().unwrap().bindings.insert(label.ident, def);
3436 fn resolve_labeled_block(&mut self, label: Option<Label>, id: NodeId, block: &Block) {
3437 self.with_resolved_label(label, id, |this| this.visit_block(block));
3440 fn resolve_expr(&mut self, expr: &Expr, parent: Option<&Expr>) {
3441 // First, record candidate traits for this expression if it could
3442 // result in the invocation of a method call.
3444 self.record_candidate_traits_for_expr_if_necessary(expr);
3446 // Next, resolve the node.
3448 ExprKind::Path(ref qself, ref path) => {
3449 self.smart_resolve_path(expr.id, qself.as_ref(), path, PathSource::Expr(parent));
3450 visit::walk_expr(self, expr);
3453 ExprKind::Struct(ref path, ..) => {
3454 self.smart_resolve_path(expr.id, None, path, PathSource::Struct);
3455 visit::walk_expr(self, expr);
3458 ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => {
3459 match self.search_label(label.ident, |rib, id| rib.bindings.get(&id).cloned()) {
3461 // Search again for close matches...
3462 // Picks the first label that is "close enough", which is not necessarily
3463 // the closest match
3464 let close_match = self.search_label(label.ident, |rib, ident| {
3465 let names = rib.bindings.iter().map(|(id, _)| &id.name);
3466 find_best_match_for_name(names, &*ident.name.as_str(), None)
3468 self.record_def(expr.id, err_path_resolution());
3471 ResolutionError::UndeclaredLabel(&label.ident.name.as_str(),
3474 Some(def @ Def::Label(_)) => {
3475 // Since this def is a label, it is never read.
3476 self.record_def(expr.id, PathResolution::new(def));
3479 span_bug!(expr.span, "label wasn't mapped to a label def!");
3483 // visit `break` argument if any
3484 visit::walk_expr(self, expr);
3487 ExprKind::IfLet(ref pats, ref subexpression, ref if_block, ref optional_else) => {
3488 self.visit_expr(subexpression);
3490 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
3491 let mut bindings_list = FxHashMap();
3493 self.resolve_pattern(pat, PatternSource::IfLet, &mut bindings_list);
3495 // This has to happen *after* we determine which pat_idents are variants
3496 self.check_consistent_bindings(pats);
3497 self.visit_block(if_block);
3498 self.ribs[ValueNS].pop();
3500 optional_else.as_ref().map(|expr| self.visit_expr(expr));
3503 ExprKind::Loop(ref block, label) => self.resolve_labeled_block(label, expr.id, &block),
3505 ExprKind::While(ref subexpression, ref block, label) => {
3506 self.with_resolved_label(label, expr.id, |this| {
3507 this.visit_expr(subexpression);
3508 this.visit_block(block);
3512 ExprKind::WhileLet(ref pats, ref subexpression, ref block, label) => {
3513 self.with_resolved_label(label, expr.id, |this| {
3514 this.visit_expr(subexpression);
3515 this.ribs[ValueNS].push(Rib::new(NormalRibKind));
3516 let mut bindings_list = FxHashMap();
3518 this.resolve_pattern(pat, PatternSource::WhileLet, &mut bindings_list);
3520 // This has to happen *after* we determine which pat_idents are variants
3521 this.check_consistent_bindings(pats);
3522 this.visit_block(block);
3523 this.ribs[ValueNS].pop();
3527 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, label) => {
3528 self.visit_expr(subexpression);
3529 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
3530 self.resolve_pattern(pattern, PatternSource::For, &mut FxHashMap());
3532 self.resolve_labeled_block(label, expr.id, block);
3534 self.ribs[ValueNS].pop();
3537 // Equivalent to `visit::walk_expr` + passing some context to children.
3538 ExprKind::Field(ref subexpression, _) => {
3539 self.resolve_expr(subexpression, Some(expr));
3541 ExprKind::MethodCall(ref segment, ref arguments) => {
3542 let mut arguments = arguments.iter();
3543 self.resolve_expr(arguments.next().unwrap(), Some(expr));
3544 for argument in arguments {
3545 self.resolve_expr(argument, None);
3547 self.visit_path_segment(expr.span, segment);
3550 ExprKind::Repeat(ref element, ref count) => {
3551 self.visit_expr(element);
3552 self.with_constant_rib(|this| {
3553 this.visit_expr(count);
3556 ExprKind::Call(ref callee, ref arguments) => {
3557 self.resolve_expr(callee, Some(expr));
3558 for argument in arguments {
3559 self.resolve_expr(argument, None);
3562 ExprKind::Type(ref type_expr, _) => {
3563 self.current_type_ascription.push(type_expr.span);
3564 visit::walk_expr(self, expr);
3565 self.current_type_ascription.pop();
3568 visit::walk_expr(self, expr);
3573 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3575 ExprKind::Field(_, name) => {
3576 // FIXME(#6890): Even though you can't treat a method like a
3577 // field, we need to add any trait methods we find that match
3578 // the field name so that we can do some nice error reporting
3579 // later on in typeck.
3580 let traits = self.get_traits_containing_item(name.node, ValueNS);
3581 self.trait_map.insert(expr.id, traits);
3583 ExprKind::MethodCall(ref segment, ..) => {
3584 debug!("(recording candidate traits for expr) recording traits for {}",
3586 let traits = self.get_traits_containing_item(segment.identifier, ValueNS);
3587 self.trait_map.insert(expr.id, traits);
3595 fn get_traits_containing_item(&mut self, mut ident: Ident, ns: Namespace)
3596 -> Vec<TraitCandidate> {
3597 debug!("(getting traits containing item) looking for '{}'", ident.name);
3599 let mut found_traits = Vec::new();
3600 // Look for the current trait.
3601 if let Some((module, _)) = self.current_trait_ref {
3602 if self.resolve_ident_in_module(module, ident, ns, false, false, module.span).is_ok() {
3603 let def_id = module.def_id().unwrap();
3604 found_traits.push(TraitCandidate { def_id: def_id, import_id: None });
3608 ident.ctxt = ident.ctxt.modern();
3609 let mut search_module = self.current_module;
3611 self.get_traits_in_module_containing_item(ident, ns, search_module, &mut found_traits);
3613 unwrap_or!(self.hygienic_lexical_parent(search_module, &mut ident.ctxt), break);
3616 if let Some(prelude) = self.prelude {
3617 if !search_module.no_implicit_prelude {
3618 self.get_traits_in_module_containing_item(ident, ns, prelude, &mut found_traits);
3625 fn get_traits_in_module_containing_item(&mut self,
3629 found_traits: &mut Vec<TraitCandidate>) {
3630 let mut traits = module.traits.borrow_mut();
3631 if traits.is_none() {
3632 let mut collected_traits = Vec::new();
3633 module.for_each_child(|name, ns, binding| {
3634 if ns != TypeNS { return }
3635 if let Def::Trait(_) = binding.def() {
3636 collected_traits.push((name, binding));
3639 *traits = Some(collected_traits.into_boxed_slice());
3642 for &(trait_name, binding) in traits.as_ref().unwrap().iter() {
3643 let module = binding.module().unwrap();
3644 let mut ident = ident;
3645 if ident.ctxt.glob_adjust(module.expansion, binding.span.ctxt().modern()).is_none() {
3648 if self.resolve_ident_in_module_unadjusted(module, ident, ns, false, false, module.span)
3650 let import_id = match binding.kind {
3651 NameBindingKind::Import { directive, .. } => {
3652 self.maybe_unused_trait_imports.insert(directive.id);
3653 self.add_to_glob_map(directive.id, trait_name);
3658 let trait_def_id = module.def_id().unwrap();
3659 found_traits.push(TraitCandidate { def_id: trait_def_id, import_id: import_id });
3664 /// When name resolution fails, this method can be used to look up candidate
3665 /// entities with the expected name. It allows filtering them using the
3666 /// supplied predicate (which should be used to only accept the types of
3667 /// definitions expected e.g. traits). The lookup spans across all crates.
3669 /// NOTE: The method does not look into imports, but this is not a problem,
3670 /// since we report the definitions (thus, the de-aliased imports).
3671 fn lookup_import_candidates<FilterFn>(&mut self,
3673 namespace: Namespace,
3674 filter_fn: FilterFn)
3675 -> Vec<ImportSuggestion>
3676 where FilterFn: Fn(Def) -> bool
3678 let mut candidates = Vec::new();
3679 let mut worklist = Vec::new();
3680 let mut seen_modules = FxHashSet();
3681 worklist.push((self.graph_root, Vec::new(), false));
3683 while let Some((in_module,
3685 in_module_is_extern)) = worklist.pop() {
3686 self.populate_module_if_necessary(in_module);
3688 // We have to visit module children in deterministic order to avoid
3689 // instabilities in reported imports (#43552).
3690 in_module.for_each_child_stable(|ident, ns, name_binding| {
3691 // avoid imports entirely
3692 if name_binding.is_import() && !name_binding.is_extern_crate() { return; }
3693 // avoid non-importable candidates as well
3694 if !name_binding.is_importable() { return; }
3696 // collect results based on the filter function
3697 if ident.name == lookup_name && ns == namespace {
3698 if filter_fn(name_binding.def()) {
3700 let mut segms = path_segments.clone();
3701 segms.push(ast::PathSegment::from_ident(ident, name_binding.span));
3703 span: name_binding.span,
3706 // the entity is accessible in the following cases:
3707 // 1. if it's defined in the same crate, it's always
3708 // accessible (since private entities can be made public)
3709 // 2. if it's defined in another crate, it's accessible
3710 // only if both the module is public and the entity is
3711 // declared as public (due to pruning, we don't explore
3712 // outside crate private modules => no need to check this)
3713 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
3714 candidates.push(ImportSuggestion { path: path });
3719 // collect submodules to explore
3720 if let Some(module) = name_binding.module() {
3722 let mut path_segments = path_segments.clone();
3723 path_segments.push(ast::PathSegment::from_ident(ident, name_binding.span));
3725 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
3726 // add the module to the lookup
3727 let is_extern = in_module_is_extern || name_binding.is_extern_crate();
3728 if seen_modules.insert(module.def_id().unwrap()) {
3729 worklist.push((module, path_segments, is_extern));
3739 fn find_module(&mut self,
3741 -> Option<(Module<'a>, ImportSuggestion)>
3743 let mut result = None;
3744 let mut worklist = Vec::new();
3745 let mut seen_modules = FxHashSet();
3746 worklist.push((self.graph_root, Vec::new()));
3748 while let Some((in_module, path_segments)) = worklist.pop() {
3749 // abort if the module is already found
3750 if let Some(_) = result { break; }
3752 self.populate_module_if_necessary(in_module);
3754 in_module.for_each_child_stable(|ident, _, name_binding| {
3755 // abort if the module is already found or if name_binding is private external
3756 if result.is_some() || !name_binding.vis.is_visible_locally() {
3759 if let Some(module) = name_binding.module() {
3761 let mut path_segments = path_segments.clone();
3762 path_segments.push(ast::PathSegment::from_ident(ident, name_binding.span));
3763 if module.def() == Some(module_def) {
3765 span: name_binding.span,
3766 segments: path_segments,
3768 result = Some((module, ImportSuggestion { path: path }));
3770 // add the module to the lookup
3771 if seen_modules.insert(module.def_id().unwrap()) {
3772 worklist.push((module, path_segments));
3782 fn collect_enum_variants(&mut self, enum_def: Def) -> Option<Vec<Path>> {
3783 if let Def::Enum(..) = enum_def {} else {
3784 panic!("Non-enum def passed to collect_enum_variants: {:?}", enum_def)
3787 self.find_module(enum_def).map(|(enum_module, enum_import_suggestion)| {
3788 self.populate_module_if_necessary(enum_module);
3790 let mut variants = Vec::new();
3791 enum_module.for_each_child_stable(|ident, _, name_binding| {
3792 if let Def::Variant(..) = name_binding.def() {
3793 let mut segms = enum_import_suggestion.path.segments.clone();
3794 segms.push(ast::PathSegment::from_ident(ident, name_binding.span));
3795 variants.push(Path {
3796 span: name_binding.span,
3805 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
3806 debug!("(recording def) recording {:?} for {}", resolution, node_id);
3807 if let Some(prev_res) = self.def_map.insert(node_id, resolution) {
3808 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
3812 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
3814 ast::VisibilityKind::Public => ty::Visibility::Public,
3815 ast::VisibilityKind::Crate(..) => {
3816 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
3818 ast::VisibilityKind::Inherited => {
3819 ty::Visibility::Restricted(self.current_module.normal_ancestor_id)
3821 ast::VisibilityKind::Restricted { ref path, id, .. } => {
3822 let def = self.smart_resolve_path(id, None, path,
3823 PathSource::Visibility).base_def();
3824 if def == Def::Err {
3825 ty::Visibility::Public
3827 let vis = ty::Visibility::Restricted(def.def_id());
3828 if self.is_accessible(vis) {
3831 self.session.span_err(path.span, "visibilities can only be restricted \
3832 to ancestor modules");
3833 ty::Visibility::Public
3840 fn is_accessible(&self, vis: ty::Visibility) -> bool {
3841 vis.is_accessible_from(self.current_module.normal_ancestor_id, self)
3844 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
3845 vis.is_accessible_from(module.normal_ancestor_id, self)
3848 fn report_errors(&mut self, krate: &Crate) {
3849 self.report_shadowing_errors();
3850 self.report_with_use_injections(krate);
3851 self.report_proc_macro_import(krate);
3852 let mut reported_spans = FxHashSet();
3854 for &AmbiguityError { span, name, b1, b2, lexical, legacy } in &self.ambiguity_errors {
3855 if !reported_spans.insert(span) { continue }
3856 let participle = |binding: &NameBinding| {
3857 if binding.is_import() { "imported" } else { "defined" }
3859 let msg1 = format!("`{}` could refer to the name {} here", name, participle(b1));
3860 let msg2 = format!("`{}` could also refer to the name {} here", name, participle(b2));
3861 let note = if b1.expansion == Mark::root() || !lexical && b1.is_glob_import() {
3862 format!("consider adding an explicit import of `{}` to disambiguate", name)
3863 } else if let Def::Macro(..) = b1.def() {
3864 format!("macro-expanded {} do not shadow",
3865 if b1.is_import() { "macro imports" } else { "macros" })
3867 format!("macro-expanded {} do not shadow when used in a macro invocation path",
3868 if b1.is_import() { "imports" } else { "items" })
3871 let id = match b2.kind {
3872 NameBindingKind::Import { directive, .. } => directive.id,
3873 _ => unreachable!(),
3875 let mut span = MultiSpan::from_span(span);
3876 span.push_span_label(b1.span, msg1);
3877 span.push_span_label(b2.span, msg2);
3878 let msg = format!("`{}` is ambiguous", name);
3879 self.session.buffer_lint(lint::builtin::LEGACY_IMPORTS, id, span, &msg);
3882 struct_span_err!(self.session, span, E0659, "`{}` is ambiguous", name);
3883 err.span_note(b1.span, &msg1);
3885 Def::Macro(..) if b2.span == DUMMY_SP =>
3886 err.note(&format!("`{}` is also a builtin macro", name)),
3887 _ => err.span_note(b2.span, &msg2),
3889 err.note(¬e).emit();
3893 for &PrivacyError(span, name, binding) in &self.privacy_errors {
3894 if !reported_spans.insert(span) { continue }
3895 span_err!(self.session, span, E0603, "{} `{}` is private", binding.descr(), name);
3899 fn report_with_use_injections(&mut self, krate: &Crate) {
3900 for UseError { mut err, candidates, node_id, better } in self.use_injections.drain(..) {
3901 let (span, found_use) = UsePlacementFinder::check(krate, node_id);
3902 if !candidates.is_empty() {
3903 show_candidates(&mut err, span, &candidates, better, found_use);
3909 fn report_shadowing_errors(&mut self) {
3910 for (ident, scope) in replace(&mut self.lexical_macro_resolutions, Vec::new()) {
3911 self.resolve_legacy_scope(scope, ident, true);
3914 let mut reported_errors = FxHashSet();
3915 for binding in replace(&mut self.disallowed_shadowing, Vec::new()) {
3916 if self.resolve_legacy_scope(&binding.parent, binding.ident, false).is_some() &&
3917 reported_errors.insert((binding.ident, binding.span)) {
3918 let msg = format!("`{}` is already in scope", binding.ident);
3919 self.session.struct_span_err(binding.span, &msg)
3920 .note("macro-expanded `macro_rules!`s may not shadow \
3921 existing macros (see RFC 1560)")
3927 fn report_conflict<'b>(&mut self,
3931 new_binding: &NameBinding<'b>,
3932 old_binding: &NameBinding<'b>) {
3933 // Error on the second of two conflicting names
3934 if old_binding.span.lo() > new_binding.span.lo() {
3935 return self.report_conflict(parent, ident, ns, old_binding, new_binding);
3938 let container = match parent.kind {
3939 ModuleKind::Def(Def::Mod(_), _) => "module",
3940 ModuleKind::Def(Def::Trait(_), _) => "trait",
3941 ModuleKind::Block(..) => "block",
3945 let old_noun = match old_binding.is_import() {
3947 false => "definition",
3950 let new_participle = match new_binding.is_import() {
3955 let (name, span) = (ident.name, self.session.codemap().def_span(new_binding.span));
3957 if let Some(s) = self.name_already_seen.get(&name) {
3963 let old_kind = match (ns, old_binding.module()) {
3964 (ValueNS, _) => "value",
3965 (MacroNS, _) => "macro",
3966 (TypeNS, _) if old_binding.is_extern_crate() => "extern crate",
3967 (TypeNS, Some(module)) if module.is_normal() => "module",
3968 (TypeNS, Some(module)) if module.is_trait() => "trait",
3969 (TypeNS, _) => "type",
3972 let namespace = match ns {
3978 let msg = format!("the name `{}` is defined multiple times", name);
3980 let mut err = match (old_binding.is_extern_crate(), new_binding.is_extern_crate()) {
3981 (true, true) => struct_span_err!(self.session, span, E0259, "{}", msg),
3982 (true, _) | (_, true) => match new_binding.is_import() && old_binding.is_import() {
3983 true => struct_span_err!(self.session, span, E0254, "{}", msg),
3984 false => struct_span_err!(self.session, span, E0260, "{}", msg),
3986 _ => match (old_binding.is_import(), new_binding.is_import()) {
3987 (false, false) => struct_span_err!(self.session, span, E0428, "{}", msg),
3988 (true, true) => struct_span_err!(self.session, span, E0252, "{}", msg),
3989 _ => struct_span_err!(self.session, span, E0255, "{}", msg),
3993 err.note(&format!("`{}` must be defined only once in the {} namespace of this {}",
3998 err.span_label(span, format!("`{}` re{} here", name, new_participle));
3999 if old_binding.span != DUMMY_SP {
4000 err.span_label(self.session.codemap().def_span(old_binding.span),
4001 format!("previous {} of the {} `{}` here", old_noun, old_kind, name));
4004 // See https://github.com/rust-lang/rust/issues/32354
4005 if old_binding.is_import() || new_binding.is_import() {
4006 let binding = if new_binding.is_import() && new_binding.span != DUMMY_SP {
4012 let cm = self.session.codemap();
4013 let rename_msg = "You can use `as` to change the binding name of the import";
4015 if let (Ok(snippet), false) = (cm.span_to_snippet(binding.span),
4016 binding.is_renamed_extern_crate()) {
4017 let suggested_name = if name.as_str().chars().next().unwrap().is_uppercase() {
4018 format!("Other{}", name)
4020 format!("other_{}", name)
4023 err.span_suggestion(binding.span,
4025 if snippet.ends_with(';') {
4026 format!("{} as {};",
4027 &snippet[..snippet.len()-1],
4030 format!("{} as {}", snippet, suggested_name)
4033 err.span_label(binding.span, rename_msg);
4038 self.name_already_seen.insert(name, span);
4041 fn warn_legacy_self_import(&self, directive: &'a ImportDirective<'a>) {
4042 let (id, span) = (directive.id, directive.span);
4043 let msg = "`self` no longer imports values";
4044 self.session.buffer_lint(lint::builtin::LEGACY_IMPORTS, id, span, msg);
4047 fn check_proc_macro_attrs(&mut self, attrs: &[ast::Attribute]) {
4048 if self.proc_macro_enabled { return; }
4051 if attr.path.segments.len() > 1 {
4054 let ident = attr.path.segments[0].identifier;
4055 let result = self.resolve_lexical_macro_path_segment(ident,
4059 if let Ok(binding) = result {
4060 if let SyntaxExtension::AttrProcMacro(..) = *binding.binding().get_macro(self) {
4061 attr::mark_known(attr);
4063 let msg = "attribute procedural macros are experimental";
4064 let feature = "proc_macro";
4066 feature_err(&self.session.parse_sess, feature,
4067 attr.span, GateIssue::Language, msg)
4068 .span_label(binding.span(), "procedural macro imported here")
4076 fn is_self_type(path: &[SpannedIdent], namespace: Namespace) -> bool {
4077 namespace == TypeNS && path.len() == 1 && path[0].node.name == keywords::SelfType.name()
4080 fn is_self_value(path: &[SpannedIdent], namespace: Namespace) -> bool {
4081 namespace == ValueNS && path.len() == 1 && path[0].node.name == keywords::SelfValue.name()
4084 fn names_to_string(idents: &[SpannedIdent]) -> String {
4085 let mut result = String::new();
4086 for (i, ident) in idents.iter()
4087 .filter(|i| i.node.name != keywords::CrateRoot.name())
4090 result.push_str("::");
4092 result.push_str(&ident.node.name.as_str());
4097 fn path_names_to_string(path: &Path) -> String {
4098 names_to_string(&path.segments.iter()
4099 .map(|seg| respan(seg.span, seg.identifier))
4100 .collect::<Vec<_>>())
4103 /// Get the path for an enum and the variant from an `ImportSuggestion` for an enum variant.
4104 fn import_candidate_to_paths(suggestion: &ImportSuggestion) -> (Span, String, String) {
4105 let variant_path = &suggestion.path;
4106 let variant_path_string = path_names_to_string(variant_path);
4108 let path_len = suggestion.path.segments.len();
4109 let enum_path = ast::Path {
4110 span: suggestion.path.span,
4111 segments: suggestion.path.segments[0..path_len - 1].to_vec(),
4113 let enum_path_string = path_names_to_string(&enum_path);
4115 (suggestion.path.span, variant_path_string, enum_path_string)
4119 /// When an entity with a given name is not available in scope, we search for
4120 /// entities with that name in all crates. This method allows outputting the
4121 /// results of this search in a programmer-friendly way
4122 fn show_candidates(err: &mut DiagnosticBuilder,
4123 // This is `None` if all placement locations are inside expansions
4125 candidates: &[ImportSuggestion],
4129 // we want consistent results across executions, but candidates are produced
4130 // by iterating through a hash map, so make sure they are ordered:
4131 let mut path_strings: Vec<_> =
4132 candidates.into_iter().map(|c| path_names_to_string(&c.path)).collect();
4133 path_strings.sort();
4135 let better = if better { "better " } else { "" };
4136 let msg_diff = match path_strings.len() {
4137 1 => " is found in another module, you can import it",
4138 _ => "s are found in other modules, you can import them",
4140 let msg = format!("possible {}candidate{} into scope", better, msg_diff);
4142 if let Some(span) = span {
4143 for candidate in &mut path_strings {
4144 // produce an additional newline to separate the new use statement
4145 // from the directly following item.
4146 let additional_newline = if found_use {
4151 *candidate = format!("use {};\n{}", candidate, additional_newline);
4154 err.span_suggestions(span, &msg, path_strings);
4158 for candidate in path_strings {
4160 msg.push_str(&candidate);
4165 /// A somewhat inefficient routine to obtain the name of a module.
4166 fn module_to_string(module: Module) -> Option<String> {
4167 let mut names = Vec::new();
4169 fn collect_mod(names: &mut Vec<Ident>, module: Module) {
4170 if let ModuleKind::Def(_, name) = module.kind {
4171 if let Some(parent) = module.parent {
4172 names.push(Ident::with_empty_ctxt(name));
4173 collect_mod(names, parent);
4176 // danger, shouldn't be ident?
4177 names.push(Ident::from_str("<opaque>"));
4178 collect_mod(names, module.parent.unwrap());
4181 collect_mod(&mut names, module);
4183 if names.is_empty() {
4186 Some(names_to_string(&names.into_iter()
4188 .map(|n| dummy_spanned(n))
4189 .collect::<Vec<_>>()))
4192 fn err_path_resolution() -> PathResolution {
4193 PathResolution::new(Def::Err)
4196 #[derive(PartialEq,Copy, Clone)]
4197 pub enum MakeGlobMap {
4202 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }