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, 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::{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;
63 use syntax_pos::{Span, DUMMY_SP, MultiSpan};
64 use errors::{DiagnosticBuilder, DiagnosticId};
66 use std::cell::{Cell, RefCell};
68 use std::collections::BTreeSet;
70 use std::mem::replace;
73 use resolve_imports::{ImportDirective, ImportDirectiveSubclass, NameResolution, ImportResolver};
74 use macros::{InvocationData, LegacyBinding, LegacyScope, MacroBinding};
76 // NB: This module needs to be declared first so diagnostics are
77 // registered before they are used.
82 mod build_reduced_graph;
85 /// A free importable items suggested in case of resolution failure.
86 struct ImportSuggestion {
90 /// A field or associated item from self type suggested in case of resolution failure.
91 enum AssocSuggestion {
100 origin: BTreeSet<Span>,
101 target: BTreeSet<Span>,
104 impl PartialOrd for BindingError {
105 fn partial_cmp(&self, other: &BindingError) -> Option<cmp::Ordering> {
106 Some(self.cmp(other))
110 impl PartialEq for BindingError {
111 fn eq(&self, other: &BindingError) -> bool {
112 self.name == other.name
116 impl Ord for BindingError {
117 fn cmp(&self, other: &BindingError) -> cmp::Ordering {
118 self.name.cmp(&other.name)
122 enum ResolutionError<'a> {
123 /// error E0401: can't use type parameters from outer function
124 TypeParametersFromOuterFunction,
125 /// error E0403: the name is already used for a type parameter in this type parameter list
126 NameAlreadyUsedInTypeParameterList(Name, &'a Span),
127 /// error E0407: method is not a member of trait
128 MethodNotMemberOfTrait(Name, &'a str),
129 /// error E0437: type is not a member of trait
130 TypeNotMemberOfTrait(Name, &'a str),
131 /// error E0438: const is not a member of trait
132 ConstNotMemberOfTrait(Name, &'a str),
133 /// error E0408: variable `{}` is not bound in all patterns
134 VariableNotBoundInPattern(&'a BindingError),
135 /// error E0409: variable `{}` is bound in inconsistent ways within the same match arm
136 VariableBoundWithDifferentMode(Name, Span),
137 /// error E0415: identifier is bound more than once in this parameter list
138 IdentifierBoundMoreThanOnceInParameterList(&'a str),
139 /// error E0416: identifier is bound more than once in the same pattern
140 IdentifierBoundMoreThanOnceInSamePattern(&'a str),
141 /// error E0426: use of undeclared label
142 UndeclaredLabel(&'a str, Option<Name>),
143 /// error E0429: `self` imports are only allowed within a { } list
144 SelfImportsOnlyAllowedWithin,
145 /// error E0430: `self` import can only appear once in the list
146 SelfImportCanOnlyAppearOnceInTheList,
147 /// error E0431: `self` import can only appear in an import list with a non-empty prefix
148 SelfImportOnlyInImportListWithNonEmptyPrefix,
149 /// error E0432: unresolved import
150 UnresolvedImport(Option<(Span, &'a str, &'a str)>),
151 /// error E0433: failed to resolve
152 FailedToResolve(&'a str),
153 /// error E0434: can't capture dynamic environment in a fn item
154 CannotCaptureDynamicEnvironmentInFnItem,
155 /// error E0435: attempt to use a non-constant value in a constant
156 AttemptToUseNonConstantValueInConstant,
157 /// error E0530: X bindings cannot shadow Ys
158 BindingShadowsSomethingUnacceptable(&'a str, Name, &'a NameBinding<'a>),
159 /// error E0128: type parameters with a default cannot use forward declared identifiers
160 ForwardDeclaredTyParam,
163 fn resolve_error<'sess, 'a>(resolver: &'sess Resolver,
165 resolution_error: ResolutionError<'a>) {
166 resolve_struct_error(resolver, span, resolution_error).emit();
169 fn resolve_struct_error<'sess, 'a>(resolver: &'sess Resolver,
171 resolution_error: ResolutionError<'a>)
172 -> DiagnosticBuilder<'sess> {
173 match resolution_error {
174 ResolutionError::TypeParametersFromOuterFunction => {
175 let mut err = struct_span_err!(resolver.session,
178 "can't use type parameters from outer function; \
179 try using a local type parameter instead");
180 err.span_label(span, "use of type variable from outer function");
183 ResolutionError::NameAlreadyUsedInTypeParameterList(name, first_use_span) => {
184 let mut err = struct_span_err!(resolver.session,
187 "the name `{}` is already used for a type parameter \
188 in this type parameter list",
190 err.span_label(span, "already used");
191 err.span_label(first_use_span.clone(), format!("first use of `{}`", name));
194 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
195 let mut err = struct_span_err!(resolver.session,
198 "method `{}` is not a member of trait `{}`",
201 err.span_label(span, format!("not a member of trait `{}`", trait_));
204 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
205 let mut err = struct_span_err!(resolver.session,
208 "type `{}` is not a member of trait `{}`",
211 err.span_label(span, format!("not a member of trait `{}`", trait_));
214 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
215 let mut err = struct_span_err!(resolver.session,
218 "const `{}` is not a member of trait `{}`",
221 err.span_label(span, format!("not a member of trait `{}`", trait_));
224 ResolutionError::VariableNotBoundInPattern(binding_error) => {
225 let target_sp = binding_error.target.iter().map(|x| *x).collect::<Vec<_>>();
226 let msp = MultiSpan::from_spans(target_sp.clone());
227 let msg = format!("variable `{}` is not bound in all patterns", binding_error.name);
228 let mut err = resolver.session.struct_span_err_with_code(
231 DiagnosticId::Error("E0408".into()),
233 for sp in target_sp {
234 err.span_label(sp, format!("pattern doesn't bind `{}`", binding_error.name));
236 let origin_sp = binding_error.origin.iter().map(|x| *x).collect::<Vec<_>>();
237 for sp in origin_sp {
238 err.span_label(sp, "variable not in all patterns");
242 ResolutionError::VariableBoundWithDifferentMode(variable_name,
243 first_binding_span) => {
244 let mut err = struct_span_err!(resolver.session,
247 "variable `{}` is bound in inconsistent \
248 ways within the same match arm",
250 err.span_label(span, "bound in different ways");
251 err.span_label(first_binding_span, "first binding");
254 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
255 let mut err = struct_span_err!(resolver.session,
258 "identifier `{}` is bound more than once in this parameter list",
260 err.span_label(span, "used as parameter more than once");
263 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
264 let mut err = struct_span_err!(resolver.session,
267 "identifier `{}` is bound more than once in the same pattern",
269 err.span_label(span, "used in a pattern more than once");
272 ResolutionError::UndeclaredLabel(name, lev_candidate) => {
273 let mut err = struct_span_err!(resolver.session,
276 "use of undeclared label `{}`",
278 if let Some(lev_candidate) = lev_candidate {
279 err.span_label(span, format!("did you mean `{}`?", lev_candidate));
281 err.span_label(span, format!("undeclared label `{}`", name));
285 ResolutionError::SelfImportsOnlyAllowedWithin => {
286 struct_span_err!(resolver.session,
290 "`self` imports are only allowed within a { } list")
292 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
293 let mut err = struct_span_err!(resolver.session, span, E0430,
294 "`self` import can only appear once in an import list");
295 err.span_label(span, "can only appear once in an import list");
298 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
299 let mut err = struct_span_err!(resolver.session, span, E0431,
300 "`self` import can only appear in an import list with \
301 a non-empty prefix");
302 err.span_label(span, "can only appear in an import list with a non-empty prefix");
305 ResolutionError::UnresolvedImport(name) => {
306 let (span, msg) = match name {
307 Some((sp, n, _)) => (sp, format!("unresolved import `{}`", n)),
308 None => (span, "unresolved import".to_owned()),
310 let mut err = struct_span_err!(resolver.session, span, E0432, "{}", msg);
311 if let Some((_, _, p)) = name {
312 err.span_label(span, p);
316 ResolutionError::FailedToResolve(msg) => {
317 let mut err = struct_span_err!(resolver.session, span, E0433,
318 "failed to resolve. {}", msg);
319 err.span_label(span, msg);
322 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
323 let mut err = struct_span_err!(resolver.session,
327 "can't capture dynamic environment in a fn item");
328 err.help("use the `|| { ... }` closure form instead");
331 ResolutionError::AttemptToUseNonConstantValueInConstant => {
332 let mut err = struct_span_err!(resolver.session, span, E0435,
333 "attempt to use a non-constant value in a constant");
334 err.span_label(span, "non-constant value");
337 ResolutionError::BindingShadowsSomethingUnacceptable(what_binding, name, binding) => {
338 let shadows_what = PathResolution::new(binding.def()).kind_name();
339 let mut err = struct_span_err!(resolver.session,
342 "{}s cannot shadow {}s", what_binding, shadows_what);
343 err.span_label(span, format!("cannot be named the same as a {}", shadows_what));
344 let participle = if binding.is_import() { "imported" } else { "defined" };
345 let msg = format!("a {} `{}` is {} here", shadows_what, name, participle);
346 err.span_label(binding.span, msg);
349 ResolutionError::ForwardDeclaredTyParam => {
350 let mut err = struct_span_err!(resolver.session, span, E0128,
351 "type parameters with a default cannot use \
352 forward declared identifiers");
353 err.span_label(span, format!("defaulted type parameters cannot be forward declared"));
359 #[derive(Copy, Clone, Debug)]
362 binding_mode: BindingMode,
365 // Map from the name in a pattern to its binding mode.
366 type BindingMap = FxHashMap<Ident, BindingInfo>;
368 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
379 fn descr(self) -> &'static str {
381 PatternSource::Match => "match binding",
382 PatternSource::IfLet => "if let binding",
383 PatternSource::WhileLet => "while let binding",
384 PatternSource::Let => "let binding",
385 PatternSource::For => "for binding",
386 PatternSource::FnParam => "function parameter",
391 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
392 enum AliasPossibility {
397 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
398 enum PathSource<'a> {
399 // Type paths `Path`.
401 // Trait paths in bounds or impls.
402 Trait(AliasPossibility),
403 // Expression paths `path`, with optional parent context.
404 Expr(Option<&'a Expr>),
405 // Paths in path patterns `Path`.
407 // Paths in struct expressions and patterns `Path { .. }`.
409 // Paths in tuple struct patterns `Path(..)`.
411 // `m::A::B` in `<T as m::A>::B::C`.
412 TraitItem(Namespace),
413 // Path in `pub(path)`
415 // Path in `use a::b::{...};`
419 impl<'a> PathSource<'a> {
420 fn namespace(self) -> Namespace {
422 PathSource::Type | PathSource::Trait(_) | PathSource::Struct |
423 PathSource::Visibility | PathSource::ImportPrefix => TypeNS,
424 PathSource::Expr(..) | PathSource::Pat | PathSource::TupleStruct => ValueNS,
425 PathSource::TraitItem(ns) => ns,
429 fn global_by_default(self) -> bool {
431 PathSource::Visibility | PathSource::ImportPrefix => true,
432 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
433 PathSource::Struct | PathSource::TupleStruct |
434 PathSource::Trait(_) | PathSource::TraitItem(..) => false,
438 fn defer_to_typeck(self) -> bool {
440 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
441 PathSource::Struct | PathSource::TupleStruct => true,
442 PathSource::Trait(_) | PathSource::TraitItem(..) |
443 PathSource::Visibility | PathSource::ImportPrefix => false,
447 fn descr_expected(self) -> &'static str {
449 PathSource::Type => "type",
450 PathSource::Trait(_) => "trait",
451 PathSource::Pat => "unit struct/variant or constant",
452 PathSource::Struct => "struct, variant or union type",
453 PathSource::TupleStruct => "tuple struct/variant",
454 PathSource::Visibility => "module",
455 PathSource::ImportPrefix => "module or enum",
456 PathSource::TraitItem(ns) => match ns {
457 TypeNS => "associated type",
458 ValueNS => "method or associated constant",
459 MacroNS => bug!("associated macro"),
461 PathSource::Expr(parent) => match parent.map(|p| &p.node) {
462 // "function" here means "anything callable" rather than `Def::Fn`,
463 // this is not precise but usually more helpful than just "value".
464 Some(&ExprKind::Call(..)) => "function",
470 fn is_expected(self, def: Def) -> bool {
472 PathSource::Type => match def {
473 Def::Struct(..) | Def::Union(..) | Def::Enum(..) |
474 Def::Trait(..) | Def::TyAlias(..) | Def::AssociatedTy(..) |
475 Def::PrimTy(..) | Def::TyParam(..) | Def::SelfTy(..) |
476 Def::TyForeign(..) => true,
479 PathSource::Trait(AliasPossibility::No) => match def {
480 Def::Trait(..) => true,
483 PathSource::Trait(AliasPossibility::Maybe) => match def {
484 Def::Trait(..) => true,
485 Def::TraitAlias(..) => true,
488 PathSource::Expr(..) => match def {
489 Def::StructCtor(_, CtorKind::Const) | Def::StructCtor(_, CtorKind::Fn) |
490 Def::VariantCtor(_, CtorKind::Const) | Def::VariantCtor(_, CtorKind::Fn) |
491 Def::Const(..) | Def::Static(..) | Def::Local(..) | Def::Upvar(..) |
492 Def::Fn(..) | Def::Method(..) | Def::AssociatedConst(..) => true,
495 PathSource::Pat => match def {
496 Def::StructCtor(_, CtorKind::Const) |
497 Def::VariantCtor(_, CtorKind::Const) |
498 Def::Const(..) | Def::AssociatedConst(..) => true,
501 PathSource::TupleStruct => match def {
502 Def::StructCtor(_, CtorKind::Fn) | Def::VariantCtor(_, CtorKind::Fn) => true,
505 PathSource::Struct => match def {
506 Def::Struct(..) | Def::Union(..) | Def::Variant(..) |
507 Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) => true,
510 PathSource::TraitItem(ns) => match def {
511 Def::AssociatedConst(..) | Def::Method(..) if ns == ValueNS => true,
512 Def::AssociatedTy(..) if ns == TypeNS => true,
515 PathSource::ImportPrefix => match def {
516 Def::Mod(..) | Def::Enum(..) => true,
519 PathSource::Visibility => match def {
520 Def::Mod(..) => true,
526 fn error_code(self, has_unexpected_resolution: bool) -> &'static str {
527 __diagnostic_used!(E0404);
528 __diagnostic_used!(E0405);
529 __diagnostic_used!(E0412);
530 __diagnostic_used!(E0422);
531 __diagnostic_used!(E0423);
532 __diagnostic_used!(E0425);
533 __diagnostic_used!(E0531);
534 __diagnostic_used!(E0532);
535 __diagnostic_used!(E0573);
536 __diagnostic_used!(E0574);
537 __diagnostic_used!(E0575);
538 __diagnostic_used!(E0576);
539 __diagnostic_used!(E0577);
540 __diagnostic_used!(E0578);
541 match (self, has_unexpected_resolution) {
542 (PathSource::Trait(_), true) => "E0404",
543 (PathSource::Trait(_), false) => "E0405",
544 (PathSource::Type, true) => "E0573",
545 (PathSource::Type, false) => "E0412",
546 (PathSource::Struct, true) => "E0574",
547 (PathSource::Struct, false) => "E0422",
548 (PathSource::Expr(..), true) => "E0423",
549 (PathSource::Expr(..), false) => "E0425",
550 (PathSource::Pat, true) | (PathSource::TupleStruct, true) => "E0532",
551 (PathSource::Pat, false) | (PathSource::TupleStruct, false) => "E0531",
552 (PathSource::TraitItem(..), true) => "E0575",
553 (PathSource::TraitItem(..), false) => "E0576",
554 (PathSource::Visibility, true) | (PathSource::ImportPrefix, true) => "E0577",
555 (PathSource::Visibility, false) | (PathSource::ImportPrefix, false) => "E0578",
560 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
567 #[derive(Clone, Default, Debug)]
568 pub struct PerNS<T> {
574 impl<T> ::std::ops::Index<Namespace> for PerNS<T> {
576 fn index(&self, ns: Namespace) -> &T {
578 ValueNS => &self.value_ns,
579 TypeNS => &self.type_ns,
580 MacroNS => self.macro_ns.as_ref().unwrap(),
585 impl<T> ::std::ops::IndexMut<Namespace> for PerNS<T> {
586 fn index_mut(&mut self, ns: Namespace) -> &mut T {
588 ValueNS => &mut self.value_ns,
589 TypeNS => &mut self.type_ns,
590 MacroNS => self.macro_ns.as_mut().unwrap(),
595 struct UsePlacementFinder {
596 target_module: NodeId,
601 impl UsePlacementFinder {
602 fn check(krate: &Crate, target_module: NodeId) -> (Option<Span>, bool) {
603 let mut finder = UsePlacementFinder {
608 visit::walk_crate(&mut finder, krate);
609 (finder.span, finder.found_use)
613 impl<'tcx> Visitor<'tcx> for UsePlacementFinder {
616 module: &'tcx ast::Mod,
618 _: &[ast::Attribute],
621 if self.span.is_some() {
624 if node_id != self.target_module {
625 visit::walk_mod(self, module);
628 // find a use statement
629 for item in &module.items {
631 ItemKind::Use(..) => {
632 // don't suggest placing a use before the prelude
633 // import or other generated ones
634 if item.span.ctxt().outer().expn_info().is_none() {
635 self.span = Some(item.span.with_hi(item.span.lo()));
636 self.found_use = true;
640 // don't place use before extern crate
641 ItemKind::ExternCrate(_) => {}
642 // but place them before the first other item
643 _ => if self.span.map_or(true, |span| item.span < span ) {
644 if item.span.ctxt().outer().expn_info().is_none() {
645 // don't insert between attributes and an item
646 if item.attrs.is_empty() {
647 self.span = Some(item.span.with_hi(item.span.lo()));
649 // find the first attribute on the item
650 for attr in &item.attrs {
651 if self.span.map_or(true, |span| attr.span < span) {
652 self.span = Some(attr.span.with_hi(attr.span.lo()));
663 impl<'a, 'tcx> Visitor<'tcx> for Resolver<'a> {
664 fn visit_item(&mut self, item: &'tcx Item) {
665 self.resolve_item(item);
667 fn visit_arm(&mut self, arm: &'tcx Arm) {
668 self.resolve_arm(arm);
670 fn visit_block(&mut self, block: &'tcx Block) {
671 self.resolve_block(block);
673 fn visit_expr(&mut self, expr: &'tcx Expr) {
674 self.resolve_expr(expr, None);
676 fn visit_local(&mut self, local: &'tcx Local) {
677 self.resolve_local(local);
679 fn visit_ty(&mut self, ty: &'tcx Ty) {
681 TyKind::Path(ref qself, ref path) => {
682 self.smart_resolve_path(ty.id, qself.as_ref(), path, PathSource::Type);
684 TyKind::ImplicitSelf => {
685 let self_ty = keywords::SelfType.ident();
686 let def = self.resolve_ident_in_lexical_scope(self_ty, TypeNS, true, ty.span)
687 .map_or(Def::Err, |d| d.def());
688 self.record_def(ty.id, PathResolution::new(def));
690 TyKind::Array(ref element, ref length) => {
691 self.visit_ty(element);
692 self.with_constant_rib(|this| {
693 this.visit_expr(length);
699 visit::walk_ty(self, ty);
701 fn visit_poly_trait_ref(&mut self,
702 tref: &'tcx ast::PolyTraitRef,
703 m: &'tcx ast::TraitBoundModifier) {
704 self.smart_resolve_path(tref.trait_ref.ref_id, None,
705 &tref.trait_ref.path, PathSource::Trait(AliasPossibility::Maybe));
706 visit::walk_poly_trait_ref(self, tref, m);
708 fn visit_variant(&mut self,
709 variant: &'tcx ast::Variant,
710 generics: &'tcx Generics,
711 item_id: ast::NodeId) {
712 if let Some(ref dis_expr) = variant.node.disr_expr {
713 // resolve the discriminator expr as a constant
714 self.with_constant_rib(|this| {
715 this.visit_expr(dis_expr);
719 // `visit::walk_variant` without the discriminant expression.
720 self.visit_variant_data(&variant.node.data,
726 fn visit_foreign_item(&mut self, foreign_item: &'tcx ForeignItem) {
727 let type_parameters = match foreign_item.node {
728 ForeignItemKind::Fn(_, ref generics) => {
729 HasTypeParameters(generics, ItemRibKind)
731 ForeignItemKind::Static(..) => NoTypeParameters,
732 ForeignItemKind::Ty => NoTypeParameters,
734 self.with_type_parameter_rib(type_parameters, |this| {
735 visit::walk_foreign_item(this, foreign_item);
738 fn visit_fn(&mut self,
739 function_kind: FnKind<'tcx>,
740 declaration: &'tcx FnDecl,
743 let rib_kind = match function_kind {
744 FnKind::ItemFn(..) => {
747 FnKind::Method(_, _, _, _) => {
748 TraitOrImplItemRibKind
750 FnKind::Closure(_) => ClosureRibKind(node_id),
753 // Create a value rib for the function.
754 self.ribs[ValueNS].push(Rib::new(rib_kind));
756 // Create a label rib for the function.
757 self.label_ribs.push(Rib::new(rib_kind));
759 // Add each argument to the rib.
760 let mut bindings_list = FxHashMap();
761 for argument in &declaration.inputs {
762 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
764 self.visit_ty(&argument.ty);
766 debug!("(resolving function) recorded argument");
768 visit::walk_fn_ret_ty(self, &declaration.output);
770 // Resolve the function body.
771 match function_kind {
772 FnKind::ItemFn(.., body) |
773 FnKind::Method(.., body) => {
774 self.visit_block(body);
776 FnKind::Closure(body) => {
777 self.visit_expr(body);
781 debug!("(resolving function) leaving function");
783 self.label_ribs.pop();
784 self.ribs[ValueNS].pop();
786 fn visit_generics(&mut self, generics: &'tcx Generics) {
787 // For type parameter defaults, we have to ban access
788 // to following type parameters, as the Substs can only
789 // provide previous type parameters as they're built.
790 let mut default_ban_rib = Rib::new(ForwardTyParamBanRibKind);
791 default_ban_rib.bindings.extend(generics.params.iter()
792 .filter_map(|p| if let GenericParam::Type(ref tp) = *p { Some(tp) } else { None })
793 .skip_while(|p| p.default.is_none())
794 .map(|p| (Ident::with_empty_ctxt(p.ident.name), Def::Err)));
796 for param in &generics.params {
798 GenericParam::Lifetime(_) => self.visit_generic_param(param),
799 GenericParam::Type(ref ty_param) => {
800 for bound in &ty_param.bounds {
801 self.visit_ty_param_bound(bound);
804 if let Some(ref ty) = ty_param.default {
805 self.ribs[TypeNS].push(default_ban_rib);
807 default_ban_rib = self.ribs[TypeNS].pop().unwrap();
810 // Allow all following defaults to refer to this type parameter.
811 default_ban_rib.bindings.remove(&Ident::with_empty_ctxt(ty_param.ident.name));
815 for p in &generics.where_clause.predicates { self.visit_where_predicate(p); }
819 #[derive(Copy, Clone)]
820 enum TypeParameters<'a, 'b> {
822 HasTypeParameters(// Type parameters.
825 // The kind of the rib used for type parameters.
829 // The rib kind controls the translation of local
830 // definitions (`Def::Local`) to upvars (`Def::Upvar`).
831 #[derive(Copy, Clone, Debug)]
833 // No translation needs to be applied.
836 // We passed through a closure scope at the given node ID.
837 // Translate upvars as appropriate.
838 ClosureRibKind(NodeId /* func id */),
840 // We passed through an impl or trait and are now in one of its
841 // methods or associated types. Allow references to ty params that impl or trait
842 // binds. Disallow any other upvars (including other ty params that are
844 TraitOrImplItemRibKind,
846 // We passed through an item scope. Disallow upvars.
849 // We're in a constant item. Can't refer to dynamic stuff.
852 // We passed through a module.
853 ModuleRibKind(Module<'a>),
855 // We passed through a `macro_rules!` statement
856 MacroDefinition(DefId),
858 // All bindings in this rib are type parameters that can't be used
859 // from the default of a type parameter because they're not declared
860 // before said type parameter. Also see the `visit_generics` override.
861 ForwardTyParamBanRibKind,
867 bindings: FxHashMap<Ident, Def>,
872 fn new(kind: RibKind<'a>) -> Rib<'a> {
874 bindings: FxHashMap(),
880 enum LexicalScopeBinding<'a> {
881 Item(&'a NameBinding<'a>),
885 impl<'a> LexicalScopeBinding<'a> {
886 fn item(self) -> Option<&'a NameBinding<'a>> {
888 LexicalScopeBinding::Item(binding) => Some(binding),
893 fn def(self) -> Def {
895 LexicalScopeBinding::Item(binding) => binding.def(),
896 LexicalScopeBinding::Def(def) => def,
902 enum PathResult<'a> {
904 NonModule(PathResolution),
906 Failed(Span, String, bool /* is the error from the last segment? */),
914 /// One node in the tree of modules.
915 pub struct ModuleData<'a> {
916 parent: Option<Module<'a>>,
919 // The def id of the closest normal module (`mod`) ancestor (including this module).
920 normal_ancestor_id: DefId,
922 resolutions: RefCell<FxHashMap<(Ident, Namespace), &'a RefCell<NameResolution<'a>>>>,
923 legacy_macro_resolutions: RefCell<Vec<(Mark, Ident, Span, MacroKind)>>,
924 macro_resolutions: RefCell<Vec<(Box<[Ident]>, Span)>>,
926 // Macro invocations that can expand into items in this module.
927 unresolved_invocations: RefCell<FxHashSet<Mark>>,
929 no_implicit_prelude: bool,
931 glob_importers: RefCell<Vec<&'a ImportDirective<'a>>>,
932 globs: RefCell<Vec<&'a ImportDirective<'a>>>,
934 // Used to memoize the traits in this module for faster searches through all traits in scope.
935 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
937 // Whether this module is populated. If not populated, any attempt to
938 // access the children must be preceded with a
939 // `populate_module_if_necessary` call.
940 populated: Cell<bool>,
942 /// Span of the module itself. Used for error reporting.
948 type Module<'a> = &'a ModuleData<'a>;
950 impl<'a> ModuleData<'a> {
951 fn new(parent: Option<Module<'a>>,
953 normal_ancestor_id: DefId,
955 span: Span) -> Self {
960 resolutions: RefCell::new(FxHashMap()),
961 legacy_macro_resolutions: RefCell::new(Vec::new()),
962 macro_resolutions: RefCell::new(Vec::new()),
963 unresolved_invocations: RefCell::new(FxHashSet()),
964 no_implicit_prelude: false,
965 glob_importers: RefCell::new(Vec::new()),
966 globs: RefCell::new((Vec::new())),
967 traits: RefCell::new(None),
968 populated: Cell::new(normal_ancestor_id.is_local()),
974 fn for_each_child<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
975 for (&(ident, ns), name_resolution) in self.resolutions.borrow().iter() {
976 name_resolution.borrow().binding.map(|binding| f(ident, ns, binding));
980 fn for_each_child_stable<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
981 let resolutions = self.resolutions.borrow();
982 let mut resolutions = resolutions.iter().map(|(&(ident, ns), &resolution)| {
983 // Pre-compute keys for sorting
984 (ident.name.as_str(), ns, ident, resolution)
986 .collect::<Vec<_>>();
987 resolutions.sort_unstable_by_key(|&(str, ns, ..)| (str, ns));
988 for &(_, ns, ident, resolution) in resolutions.iter() {
989 resolution.borrow().binding.map(|binding| f(ident, ns, binding));
993 fn def(&self) -> Option<Def> {
995 ModuleKind::Def(def, _) => Some(def),
1000 fn def_id(&self) -> Option<DefId> {
1001 self.def().as_ref().map(Def::def_id)
1004 // `self` resolves to the first module ancestor that `is_normal`.
1005 fn is_normal(&self) -> bool {
1007 ModuleKind::Def(Def::Mod(_), _) => true,
1012 fn is_trait(&self) -> bool {
1014 ModuleKind::Def(Def::Trait(_), _) => true,
1019 fn is_local(&self) -> bool {
1020 self.normal_ancestor_id.is_local()
1023 fn nearest_item_scope(&'a self) -> Module<'a> {
1024 if self.is_trait() { self.parent.unwrap() } else { self }
1028 impl<'a> fmt::Debug for ModuleData<'a> {
1029 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1030 write!(f, "{:?}", self.def())
1034 // Records a possibly-private value, type, or module definition.
1035 #[derive(Clone, Debug)]
1036 pub struct NameBinding<'a> {
1037 kind: NameBindingKind<'a>,
1040 vis: ty::Visibility,
1043 pub trait ToNameBinding<'a> {
1044 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
1047 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
1048 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
1053 #[derive(Clone, Debug)]
1054 enum NameBindingKind<'a> {
1058 binding: &'a NameBinding<'a>,
1059 directive: &'a ImportDirective<'a>,
1061 legacy_self_import: bool,
1064 b1: &'a NameBinding<'a>,
1065 b2: &'a NameBinding<'a>,
1070 struct PrivacyError<'a>(Span, Name, &'a NameBinding<'a>);
1072 struct UseError<'a> {
1073 err: DiagnosticBuilder<'a>,
1074 /// Attach `use` statements for these candidates
1075 candidates: Vec<ImportSuggestion>,
1076 /// The node id of the module to place the use statements in
1078 /// Whether the diagnostic should state that it's "better"
1082 struct AmbiguityError<'a> {
1086 b1: &'a NameBinding<'a>,
1087 b2: &'a NameBinding<'a>,
1091 impl<'a> NameBinding<'a> {
1092 fn module(&self) -> Option<Module<'a>> {
1094 NameBindingKind::Module(module) => Some(module),
1095 NameBindingKind::Import { binding, .. } => binding.module(),
1096 NameBindingKind::Ambiguity { legacy: true, b1, .. } => b1.module(),
1101 fn def(&self) -> Def {
1103 NameBindingKind::Def(def) => def,
1104 NameBindingKind::Module(module) => module.def().unwrap(),
1105 NameBindingKind::Import { binding, .. } => binding.def(),
1106 NameBindingKind::Ambiguity { legacy: true, b1, .. } => b1.def(),
1107 NameBindingKind::Ambiguity { .. } => Def::Err,
1111 fn def_ignoring_ambiguity(&self) -> Def {
1113 NameBindingKind::Import { binding, .. } => binding.def_ignoring_ambiguity(),
1114 NameBindingKind::Ambiguity { b1, .. } => b1.def_ignoring_ambiguity(),
1119 fn get_macro(&self, resolver: &mut Resolver<'a>) -> Rc<SyntaxExtension> {
1120 resolver.get_macro(self.def_ignoring_ambiguity())
1123 // We sometimes need to treat variants as `pub` for backwards compatibility
1124 fn pseudo_vis(&self) -> ty::Visibility {
1125 if self.is_variant() && self.def().def_id().is_local() {
1126 ty::Visibility::Public
1132 fn is_variant(&self) -> bool {
1134 NameBindingKind::Def(Def::Variant(..)) |
1135 NameBindingKind::Def(Def::VariantCtor(..)) => true,
1140 fn is_extern_crate(&self) -> bool {
1142 NameBindingKind::Import {
1143 directive: &ImportDirective {
1144 subclass: ImportDirectiveSubclass::ExternCrate(_), ..
1151 fn is_import(&self) -> bool {
1153 NameBindingKind::Import { .. } => true,
1158 fn is_renamed_extern_crate(&self) -> bool {
1159 if let NameBindingKind::Import { directive, ..} = self.kind {
1160 if let ImportDirectiveSubclass::ExternCrate(Some(_)) = directive.subclass {
1167 fn is_glob_import(&self) -> bool {
1169 NameBindingKind::Import { directive, .. } => directive.is_glob(),
1170 NameBindingKind::Ambiguity { b1, .. } => b1.is_glob_import(),
1175 fn is_importable(&self) -> bool {
1177 Def::AssociatedConst(..) | Def::Method(..) | Def::AssociatedTy(..) => false,
1182 fn is_macro_def(&self) -> bool {
1184 NameBindingKind::Def(Def::Macro(..)) => true,
1189 fn descr(&self) -> &'static str {
1190 if self.is_extern_crate() { "extern crate" } else { self.def().kind_name() }
1194 /// Interns the names of the primitive types.
1195 struct PrimitiveTypeTable {
1196 primitive_types: FxHashMap<Name, PrimTy>,
1199 impl PrimitiveTypeTable {
1200 fn new() -> PrimitiveTypeTable {
1201 let mut table = PrimitiveTypeTable { primitive_types: FxHashMap() };
1203 table.intern("bool", TyBool);
1204 table.intern("char", TyChar);
1205 table.intern("f32", TyFloat(FloatTy::F32));
1206 table.intern("f64", TyFloat(FloatTy::F64));
1207 table.intern("isize", TyInt(IntTy::Isize));
1208 table.intern("i8", TyInt(IntTy::I8));
1209 table.intern("i16", TyInt(IntTy::I16));
1210 table.intern("i32", TyInt(IntTy::I32));
1211 table.intern("i64", TyInt(IntTy::I64));
1212 table.intern("i128", TyInt(IntTy::I128));
1213 table.intern("str", TyStr);
1214 table.intern("usize", TyUint(UintTy::Usize));
1215 table.intern("u8", TyUint(UintTy::U8));
1216 table.intern("u16", TyUint(UintTy::U16));
1217 table.intern("u32", TyUint(UintTy::U32));
1218 table.intern("u64", TyUint(UintTy::U64));
1219 table.intern("u128", TyUint(UintTy::U128));
1223 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1224 self.primitive_types.insert(Symbol::intern(string), primitive_type);
1228 /// The main resolver class.
1229 pub struct Resolver<'a> {
1230 session: &'a Session,
1231 cstore: &'a CrateStore,
1233 pub definitions: Definitions,
1235 graph_root: Module<'a>,
1237 prelude: Option<Module<'a>>,
1239 // n.b. This is used only for better diagnostics, not name resolution itself.
1240 has_self: FxHashSet<DefId>,
1242 // Names of fields of an item `DefId` accessible with dot syntax.
1243 // Used for hints during error reporting.
1244 field_names: FxHashMap<DefId, Vec<Name>>,
1246 // All imports known to succeed or fail.
1247 determined_imports: Vec<&'a ImportDirective<'a>>,
1249 // All non-determined imports.
1250 indeterminate_imports: Vec<&'a ImportDirective<'a>>,
1252 // The module that represents the current item scope.
1253 current_module: Module<'a>,
1255 // The current set of local scopes for types and values.
1256 // FIXME #4948: Reuse ribs to avoid allocation.
1257 ribs: PerNS<Vec<Rib<'a>>>,
1259 // The current set of local scopes, for labels.
1260 label_ribs: Vec<Rib<'a>>,
1262 // The trait that the current context can refer to.
1263 current_trait_ref: Option<(Module<'a>, TraitRef)>,
1265 // The current self type if inside an impl (used for better errors).
1266 current_self_type: Option<Ty>,
1268 // The idents for the primitive types.
1269 primitive_type_table: PrimitiveTypeTable,
1272 pub freevars: FreevarMap,
1273 freevars_seen: NodeMap<NodeMap<usize>>,
1274 pub export_map: ExportMap,
1275 pub trait_map: TraitMap,
1277 // A map from nodes to anonymous modules.
1278 // Anonymous modules are pseudo-modules that are implicitly created around items
1279 // contained within blocks.
1281 // For example, if we have this:
1289 // There will be an anonymous module created around `g` with the ID of the
1290 // entry block for `f`.
1291 block_map: NodeMap<Module<'a>>,
1292 module_map: FxHashMap<DefId, Module<'a>>,
1293 extern_module_map: FxHashMap<(DefId, bool /* MacrosOnly? */), Module<'a>>,
1295 pub make_glob_map: bool,
1296 /// Maps imports to the names of items actually imported (this actually maps
1297 /// all imports, but only glob imports are actually interesting).
1298 pub glob_map: GlobMap,
1300 used_imports: FxHashSet<(NodeId, Namespace)>,
1301 pub maybe_unused_trait_imports: NodeSet,
1302 pub maybe_unused_extern_crates: Vec<(NodeId, Span)>,
1304 /// privacy errors are delayed until the end in order to deduplicate them
1305 privacy_errors: Vec<PrivacyError<'a>>,
1306 /// ambiguity errors are delayed for deduplication
1307 ambiguity_errors: Vec<AmbiguityError<'a>>,
1308 /// `use` injections are delayed for better placement and deduplication
1309 use_injections: Vec<UseError<'a>>,
1310 /// `use` injections for proc macros wrongly imported with #[macro_use]
1311 proc_mac_errors: Vec<macros::ProcMacError>,
1313 gated_errors: FxHashSet<Span>,
1314 disallowed_shadowing: Vec<&'a LegacyBinding<'a>>,
1316 arenas: &'a ResolverArenas<'a>,
1317 dummy_binding: &'a NameBinding<'a>,
1318 use_extern_macros: bool, // true if `#![feature(use_extern_macros)]`
1320 crate_loader: &'a mut CrateLoader,
1321 macro_names: FxHashSet<Ident>,
1322 global_macros: FxHashMap<Name, &'a NameBinding<'a>>,
1323 lexical_macro_resolutions: Vec<(Ident, &'a Cell<LegacyScope<'a>>)>,
1324 macro_map: FxHashMap<DefId, Rc<SyntaxExtension>>,
1325 macro_defs: FxHashMap<Mark, DefId>,
1326 local_macro_def_scopes: FxHashMap<NodeId, Module<'a>>,
1327 macro_exports: Vec<Export>,
1328 pub whitelisted_legacy_custom_derives: Vec<Name>,
1329 pub found_unresolved_macro: bool,
1331 // List of crate local macros that we need to warn about as being unused.
1332 // Right now this only includes macro_rules! macros, and macros 2.0.
1333 unused_macros: FxHashSet<DefId>,
1335 // Maps the `Mark` of an expansion to its containing module or block.
1336 invocations: FxHashMap<Mark, &'a InvocationData<'a>>,
1338 // Avoid duplicated errors for "name already defined".
1339 name_already_seen: FxHashMap<Name, Span>,
1341 // If `#![feature(proc_macro)]` is set
1342 proc_macro_enabled: bool,
1344 // A set of procedural macros imported by `#[macro_use]` that have already been warned about
1345 warned_proc_macros: FxHashSet<Name>,
1347 potentially_unused_imports: Vec<&'a ImportDirective<'a>>,
1349 // This table maps struct IDs into struct constructor IDs,
1350 // it's not used during normal resolution, only for better error reporting.
1351 struct_constructors: DefIdMap<(Def, ty::Visibility)>,
1353 // Only used for better errors on `fn(): fn()`
1354 current_type_ascription: Vec<Span>,
1356 injected_crate: Option<Module<'a>>,
1359 pub struct ResolverArenas<'a> {
1360 modules: arena::TypedArena<ModuleData<'a>>,
1361 local_modules: RefCell<Vec<Module<'a>>>,
1362 name_bindings: arena::TypedArena<NameBinding<'a>>,
1363 import_directives: arena::TypedArena<ImportDirective<'a>>,
1364 name_resolutions: arena::TypedArena<RefCell<NameResolution<'a>>>,
1365 invocation_data: arena::TypedArena<InvocationData<'a>>,
1366 legacy_bindings: arena::TypedArena<LegacyBinding<'a>>,
1369 impl<'a> ResolverArenas<'a> {
1370 fn alloc_module(&'a self, module: ModuleData<'a>) -> Module<'a> {
1371 let module = self.modules.alloc(module);
1372 if module.def_id().map(|def_id| def_id.is_local()).unwrap_or(true) {
1373 self.local_modules.borrow_mut().push(module);
1377 fn local_modules(&'a self) -> ::std::cell::Ref<'a, Vec<Module<'a>>> {
1378 self.local_modules.borrow()
1380 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1381 self.name_bindings.alloc(name_binding)
1383 fn alloc_import_directive(&'a self, import_directive: ImportDirective<'a>)
1384 -> &'a ImportDirective {
1385 self.import_directives.alloc(import_directive)
1387 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1388 self.name_resolutions.alloc(Default::default())
1390 fn alloc_invocation_data(&'a self, expansion_data: InvocationData<'a>)
1391 -> &'a InvocationData<'a> {
1392 self.invocation_data.alloc(expansion_data)
1394 fn alloc_legacy_binding(&'a self, binding: LegacyBinding<'a>) -> &'a LegacyBinding<'a> {
1395 self.legacy_bindings.alloc(binding)
1399 impl<'a, 'b: 'a> ty::DefIdTree for &'a Resolver<'b> {
1400 fn parent(self, id: DefId) -> Option<DefId> {
1402 LOCAL_CRATE => self.definitions.def_key(id.index).parent,
1403 _ => self.cstore.def_key(id).parent,
1404 }.map(|index| DefId { index: index, ..id })
1408 impl<'a> hir::lowering::Resolver for Resolver<'a> {
1409 fn resolve_hir_path(&mut self, path: &mut hir::Path, is_value: bool) {
1410 let namespace = if is_value { ValueNS } else { TypeNS };
1411 let hir::Path { ref segments, span, ref mut def } = *path;
1412 let path: Vec<SpannedIdent> = segments.iter()
1413 .map(|seg| respan(span, Ident::with_empty_ctxt(seg.name)))
1415 match self.resolve_path(&path, Some(namespace), true, span) {
1416 PathResult::Module(module) => *def = module.def().unwrap(),
1417 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 =>
1418 *def = path_res.base_def(),
1419 PathResult::NonModule(..) => match self.resolve_path(&path, None, true, span) {
1420 PathResult::Failed(span, msg, _) => {
1421 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
1425 PathResult::Indeterminate => unreachable!(),
1426 PathResult::Failed(span, msg, _) => {
1427 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
1432 fn get_resolution(&mut self, id: NodeId) -> Option<PathResolution> {
1433 self.def_map.get(&id).cloned()
1436 fn definitions(&mut self) -> &mut Definitions {
1437 &mut self.definitions
1441 impl<'a> Resolver<'a> {
1442 pub fn new(session: &'a Session,
1443 cstore: &'a CrateStore,
1446 make_glob_map: MakeGlobMap,
1447 crate_loader: &'a mut CrateLoader,
1448 arenas: &'a ResolverArenas<'a>)
1450 let root_def_id = DefId::local(CRATE_DEF_INDEX);
1451 let root_module_kind = ModuleKind::Def(Def::Mod(root_def_id), keywords::Invalid.name());
1452 let graph_root = arenas.alloc_module(ModuleData {
1453 no_implicit_prelude: attr::contains_name(&krate.attrs, "no_implicit_prelude"),
1454 ..ModuleData::new(None, root_module_kind, root_def_id, Mark::root(), krate.span)
1456 let mut module_map = FxHashMap();
1457 module_map.insert(DefId::local(CRATE_DEF_INDEX), graph_root);
1459 let mut definitions = Definitions::new();
1460 DefCollector::new(&mut definitions, Mark::root())
1461 .collect_root(crate_name, session.local_crate_disambiguator());
1463 let mut invocations = FxHashMap();
1464 invocations.insert(Mark::root(),
1465 arenas.alloc_invocation_data(InvocationData::root(graph_root)));
1467 let features = session.features.borrow();
1469 let mut macro_defs = FxHashMap();
1470 macro_defs.insert(Mark::root(), root_def_id);
1479 // The outermost module has def ID 0; this is not reflected in the
1484 has_self: FxHashSet(),
1485 field_names: FxHashMap(),
1487 determined_imports: Vec::new(),
1488 indeterminate_imports: Vec::new(),
1490 current_module: graph_root,
1492 value_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1493 type_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1494 macro_ns: Some(vec![Rib::new(ModuleRibKind(graph_root))]),
1496 label_ribs: Vec::new(),
1498 current_trait_ref: None,
1499 current_self_type: None,
1501 primitive_type_table: PrimitiveTypeTable::new(),
1504 freevars: NodeMap(),
1505 freevars_seen: NodeMap(),
1506 export_map: FxHashMap(),
1507 trait_map: NodeMap(),
1509 block_map: NodeMap(),
1510 extern_module_map: FxHashMap(),
1512 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1513 glob_map: NodeMap(),
1515 used_imports: FxHashSet(),
1516 maybe_unused_trait_imports: NodeSet(),
1517 maybe_unused_extern_crates: Vec::new(),
1519 privacy_errors: Vec::new(),
1520 ambiguity_errors: Vec::new(),
1521 use_injections: Vec::new(),
1522 proc_mac_errors: Vec::new(),
1523 gated_errors: FxHashSet(),
1524 disallowed_shadowing: Vec::new(),
1527 dummy_binding: arenas.alloc_name_binding(NameBinding {
1528 kind: NameBindingKind::Def(Def::Err),
1529 expansion: Mark::root(),
1531 vis: ty::Visibility::Public,
1534 // The `proc_macro` and `decl_macro` features imply `use_extern_macros`
1536 features.use_extern_macros || features.proc_macro || features.decl_macro,
1539 macro_names: FxHashSet(),
1540 global_macros: FxHashMap(),
1541 lexical_macro_resolutions: Vec::new(),
1542 macro_map: FxHashMap(),
1543 macro_exports: Vec::new(),
1546 local_macro_def_scopes: FxHashMap(),
1547 name_already_seen: FxHashMap(),
1548 whitelisted_legacy_custom_derives: Vec::new(),
1549 proc_macro_enabled: features.proc_macro,
1550 warned_proc_macros: FxHashSet(),
1551 potentially_unused_imports: Vec::new(),
1552 struct_constructors: DefIdMap(),
1553 found_unresolved_macro: false,
1554 unused_macros: FxHashSet(),
1555 current_type_ascription: Vec::new(),
1556 injected_crate: None,
1560 pub fn arenas() -> ResolverArenas<'a> {
1562 modules: arena::TypedArena::new(),
1563 local_modules: RefCell::new(Vec::new()),
1564 name_bindings: arena::TypedArena::new(),
1565 import_directives: arena::TypedArena::new(),
1566 name_resolutions: arena::TypedArena::new(),
1567 invocation_data: arena::TypedArena::new(),
1568 legacy_bindings: arena::TypedArena::new(),
1572 fn per_ns<T, F: FnMut(&mut Self, Namespace) -> T>(&mut self, mut f: F) -> PerNS<T> {
1574 type_ns: f(self, TypeNS),
1575 value_ns: f(self, ValueNS),
1576 macro_ns: match self.use_extern_macros {
1577 true => Some(f(self, MacroNS)),
1583 fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
1585 match self.macro_defs.get(&ctxt.outer()) {
1586 Some(&def_id) => return def_id,
1587 None => ctxt.remove_mark(),
1592 /// Entry point to crate resolution.
1593 pub fn resolve_crate(&mut self, krate: &Crate) {
1594 ImportResolver { resolver: self }.finalize_imports();
1595 self.current_module = self.graph_root;
1596 self.finalize_current_module_macro_resolutions();
1598 visit::walk_crate(self, krate);
1600 check_unused::check_crate(self, krate);
1601 self.report_errors(krate);
1602 self.crate_loader.postprocess(krate);
1609 normal_ancestor_id: DefId,
1613 let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expansion, span);
1614 self.arenas.alloc_module(module)
1617 fn record_use(&mut self, ident: Ident, ns: Namespace, binding: &'a NameBinding<'a>, span: Span)
1618 -> bool /* true if an error was reported */ {
1619 match binding.kind {
1620 NameBindingKind::Import { directive, binding, ref used, legacy_self_import }
1623 directive.used.set(true);
1624 if legacy_self_import {
1625 self.warn_legacy_self_import(directive);
1628 self.used_imports.insert((directive.id, ns));
1629 self.add_to_glob_map(directive.id, ident);
1630 self.record_use(ident, ns, binding, span)
1632 NameBindingKind::Import { .. } => false,
1633 NameBindingKind::Ambiguity { b1, b2, legacy } => {
1634 self.ambiguity_errors.push(AmbiguityError {
1635 span: span, name: ident.name, lexical: false, b1: b1, b2: b2, legacy,
1638 self.record_use(ident, ns, b1, span);
1646 fn add_to_glob_map(&mut self, id: NodeId, ident: Ident) {
1647 if self.make_glob_map {
1648 self.glob_map.entry(id).or_insert_with(FxHashSet).insert(ident.name);
1652 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1653 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1654 /// `ident` in the first scope that defines it (or None if no scopes define it).
1656 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1657 /// the items are defined in the block. For example,
1660 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1663 /// g(); // This resolves to the local variable `g` since it shadows the item.
1667 /// Invariant: This must only be called during main resolution, not during
1668 /// import resolution.
1669 fn resolve_ident_in_lexical_scope(&mut self,
1674 -> Option<LexicalScopeBinding<'a>> {
1676 ident.ctxt = if ident.name == keywords::SelfType.name() {
1677 SyntaxContext::empty() // FIXME(jseyfried) improve `Self` hygiene
1683 // Walk backwards up the ribs in scope.
1684 let mut module = self.graph_root;
1685 for i in (0 .. self.ribs[ns].len()).rev() {
1686 if let Some(def) = self.ribs[ns][i].bindings.get(&ident).cloned() {
1687 // The ident resolves to a type parameter or local variable.
1688 return Some(LexicalScopeBinding::Def(
1689 self.adjust_local_def(ns, i, def, record_used, path_span)
1693 module = match self.ribs[ns][i].kind {
1694 ModuleRibKind(module) => module,
1695 MacroDefinition(def) if def == self.macro_def(ident.ctxt) => {
1696 // If an invocation of this macro created `ident`, give up on `ident`
1697 // and switch to `ident`'s source from the macro definition.
1698 ident.ctxt.remove_mark();
1704 let item = self.resolve_ident_in_module_unadjusted(
1705 module, ident, ns, false, record_used, path_span,
1707 if let Ok(binding) = item {
1708 // The ident resolves to an item.
1709 return Some(LexicalScopeBinding::Item(binding));
1713 ModuleKind::Block(..) => {}, // We can see through blocks
1718 ident.ctxt = ident.ctxt.modern();
1720 module = unwrap_or!(self.hygienic_lexical_parent(module, &mut ident.ctxt), break);
1721 let orig_current_module = self.current_module;
1722 self.current_module = module; // Lexical resolutions can never be a privacy error.
1723 let result = self.resolve_ident_in_module_unadjusted(
1724 module, ident, ns, false, record_used, path_span,
1726 self.current_module = orig_current_module;
1729 Ok(binding) => return Some(LexicalScopeBinding::Item(binding)),
1730 Err(Undetermined) => return None,
1731 Err(Determined) => {}
1735 match self.prelude {
1736 Some(prelude) if !module.no_implicit_prelude => {
1737 self.resolve_ident_in_module_unadjusted(prelude, ident, ns, false, false, path_span)
1738 .ok().map(LexicalScopeBinding::Item)
1744 fn hygienic_lexical_parent(&mut self, mut module: Module<'a>, ctxt: &mut SyntaxContext)
1745 -> Option<Module<'a>> {
1746 if !module.expansion.is_descendant_of(ctxt.outer()) {
1747 return Some(self.macro_def_scope(ctxt.remove_mark()));
1750 if let ModuleKind::Block(..) = module.kind {
1751 return Some(module.parent.unwrap());
1754 let mut module_expansion = module.expansion.modern(); // for backward compatibility
1755 while let Some(parent) = module.parent {
1756 let parent_expansion = parent.expansion.modern();
1757 if module_expansion.is_descendant_of(parent_expansion) &&
1758 parent_expansion != module_expansion {
1759 return if parent_expansion.is_descendant_of(ctxt.outer()) {
1766 module_expansion = parent_expansion;
1772 fn resolve_ident_in_module(&mut self,
1776 ignore_unresolved_invocations: bool,
1779 -> Result<&'a NameBinding<'a>, Determinacy> {
1780 ident.ctxt = ident.ctxt.modern();
1781 let orig_current_module = self.current_module;
1782 if let Some(def) = ident.ctxt.adjust(module.expansion) {
1783 self.current_module = self.macro_def_scope(def);
1785 let result = self.resolve_ident_in_module_unadjusted(
1786 module, ident, ns, ignore_unresolved_invocations, record_used, span,
1788 self.current_module = orig_current_module;
1792 fn resolve_crate_root(&mut self, mut ctxt: SyntaxContext) -> Module<'a> {
1793 let module = match ctxt.adjust(Mark::root()) {
1794 Some(def) => self.macro_def_scope(def),
1795 None => return self.graph_root,
1797 self.get_module(DefId { index: CRATE_DEF_INDEX, ..module.normal_ancestor_id })
1800 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
1801 let mut module = self.get_module(module.normal_ancestor_id);
1802 while module.span.ctxt().modern() != *ctxt {
1803 let parent = module.parent.unwrap_or_else(|| self.macro_def_scope(ctxt.remove_mark()));
1804 module = self.get_module(parent.normal_ancestor_id);
1811 // We maintain a list of value ribs and type ribs.
1813 // Simultaneously, we keep track of the current position in the module
1814 // graph in the `current_module` pointer. When we go to resolve a name in
1815 // the value or type namespaces, we first look through all the ribs and
1816 // then query the module graph. When we resolve a name in the module
1817 // namespace, we can skip all the ribs (since nested modules are not
1818 // allowed within blocks in Rust) and jump straight to the current module
1821 // Named implementations are handled separately. When we find a method
1822 // call, we consult the module node to find all of the implementations in
1823 // scope. This information is lazily cached in the module node. We then
1824 // generate a fake "implementation scope" containing all the
1825 // implementations thus found, for compatibility with old resolve pass.
1827 fn with_scope<F>(&mut self, id: NodeId, f: F)
1828 where F: FnOnce(&mut Resolver)
1830 let id = self.definitions.local_def_id(id);
1831 let module = self.module_map.get(&id).cloned(); // clones a reference
1832 if let Some(module) = module {
1833 // Move down in the graph.
1834 let orig_module = replace(&mut self.current_module, module);
1835 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(module)));
1836 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(module)));
1838 self.finalize_current_module_macro_resolutions();
1841 self.current_module = orig_module;
1842 self.ribs[ValueNS].pop();
1843 self.ribs[TypeNS].pop();
1849 /// Searches the current set of local scopes for labels. Returns the first non-None label that
1850 /// is returned by the given predicate function
1852 /// Stops after meeting a closure.
1853 fn search_label<P, R>(&self, mut ident: Ident, pred: P) -> Option<R>
1854 where P: Fn(&Rib, Ident) -> Option<R>
1856 for rib in self.label_ribs.iter().rev() {
1859 // If an invocation of this macro created `ident`, give up on `ident`
1860 // and switch to `ident`'s source from the macro definition.
1861 MacroDefinition(def) => {
1862 if def == self.macro_def(ident.ctxt) {
1863 ident.ctxt.remove_mark();
1867 // Do not resolve labels across function boundary
1871 let r = pred(rib, ident);
1879 fn resolve_item(&mut self, item: &Item) {
1880 let name = item.ident.name;
1882 debug!("(resolving item) resolving {}", name);
1884 self.check_proc_macro_attrs(&item.attrs);
1887 ItemKind::Enum(_, ref generics) |
1888 ItemKind::Ty(_, ref generics) |
1889 ItemKind::Struct(_, ref generics) |
1890 ItemKind::Union(_, ref generics) |
1891 ItemKind::Fn(.., ref generics, _) => {
1892 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind),
1893 |this| visit::walk_item(this, item));
1896 ItemKind::AutoImpl(_, ref trait_ref) => {
1897 self.with_optional_trait_ref(Some(trait_ref), |this, _| {
1898 // Resolve type arguments in trait path
1899 visit::walk_trait_ref(this, trait_ref);
1902 ItemKind::Impl(.., ref generics, ref opt_trait_ref, ref self_type, ref impl_items) =>
1903 self.resolve_implementation(generics,
1909 ItemKind::Trait(.., ref generics, ref bounds, ref trait_items) => {
1910 // Create a new rib for the trait-wide type parameters.
1911 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
1912 let local_def_id = this.definitions.local_def_id(item.id);
1913 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
1914 this.visit_generics(generics);
1915 walk_list!(this, visit_ty_param_bound, bounds);
1917 for trait_item in trait_items {
1918 this.check_proc_macro_attrs(&trait_item.attrs);
1920 let type_parameters = HasTypeParameters(&trait_item.generics,
1921 TraitOrImplItemRibKind);
1922 this.with_type_parameter_rib(type_parameters, |this| {
1923 match trait_item.node {
1924 TraitItemKind::Const(ref ty, ref default) => {
1927 // Only impose the restrictions of
1928 // ConstRibKind for an actual constant
1929 // expression in a provided default.
1930 if let Some(ref expr) = *default{
1931 this.with_constant_rib(|this| {
1932 this.visit_expr(expr);
1936 TraitItemKind::Method(_, _) => {
1937 visit::walk_trait_item(this, trait_item)
1939 TraitItemKind::Type(..) => {
1940 visit::walk_trait_item(this, trait_item)
1942 TraitItemKind::Macro(_) => {
1943 panic!("unexpanded macro in resolve!")
1952 ItemKind::TraitAlias(ref generics, ref bounds) => {
1953 // Create a new rib for the trait-wide type parameters.
1954 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
1955 let local_def_id = this.definitions.local_def_id(item.id);
1956 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
1957 this.visit_generics(generics);
1958 walk_list!(this, visit_ty_param_bound, bounds);
1963 ItemKind::Mod(_) | ItemKind::ForeignMod(_) => {
1964 self.with_scope(item.id, |this| {
1965 visit::walk_item(this, item);
1969 ItemKind::Static(ref ty, _, ref expr) |
1970 ItemKind::Const(ref ty, ref expr) => {
1971 self.with_item_rib(|this| {
1973 this.with_constant_rib(|this| {
1974 this.visit_expr(expr);
1979 ItemKind::Use(ref use_tree) => {
1982 span: use_tree.span,
1984 self.resolve_use_tree(item, use_tree, &path);
1987 ItemKind::ExternCrate(_) | ItemKind::MacroDef(..) | ItemKind::GlobalAsm(_) => {
1988 // do nothing, these are just around to be encoded
1991 ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"),
1995 fn resolve_use_tree(&mut self, item: &Item, use_tree: &ast::UseTree, prefix: &Path) {
1996 match use_tree.kind {
1997 ast::UseTreeKind::Nested(ref items) => {
1999 segments: prefix.segments
2001 .chain(use_tree.prefix.segments.iter())
2004 span: prefix.span.to(use_tree.prefix.span),
2007 if items.len() == 0 {
2008 // Resolve prefix of an import with empty braces (issue #28388).
2009 self.smart_resolve_path(item.id, None, &path, PathSource::ImportPrefix);
2011 for &(ref tree, _) in items {
2012 self.resolve_use_tree(item, tree, &path);
2016 ast::UseTreeKind::Simple(_) => {},
2017 ast::UseTreeKind::Glob => {},
2021 fn with_type_parameter_rib<'b, F>(&'b mut self, type_parameters: TypeParameters<'a, 'b>, f: F)
2022 where F: FnOnce(&mut Resolver)
2024 match type_parameters {
2025 HasTypeParameters(generics, rib_kind) => {
2026 let mut function_type_rib = Rib::new(rib_kind);
2027 let mut seen_bindings = FxHashMap();
2028 for param in &generics.params {
2029 if let GenericParam::Type(ref type_parameter) = *param {
2030 let ident = type_parameter.ident.modern();
2031 debug!("with_type_parameter_rib: {}", type_parameter.id);
2033 if seen_bindings.contains_key(&ident) {
2034 let span = seen_bindings.get(&ident).unwrap();
2035 let err = ResolutionError::NameAlreadyUsedInTypeParameterList(
2039 resolve_error(self, type_parameter.span, err);
2041 seen_bindings.entry(ident).or_insert(type_parameter.span);
2043 // plain insert (no renaming)
2044 let def_id = self.definitions.local_def_id(type_parameter.id);
2045 let def = Def::TyParam(def_id);
2046 function_type_rib.bindings.insert(ident, def);
2047 self.record_def(type_parameter.id, PathResolution::new(def));
2050 self.ribs[TypeNS].push(function_type_rib);
2053 NoTypeParameters => {
2060 if let HasTypeParameters(..) = type_parameters {
2061 self.ribs[TypeNS].pop();
2065 fn with_label_rib<F>(&mut self, f: F)
2066 where F: FnOnce(&mut Resolver)
2068 self.label_ribs.push(Rib::new(NormalRibKind));
2070 self.label_ribs.pop();
2073 fn with_item_rib<F>(&mut self, f: F)
2074 where F: FnOnce(&mut Resolver)
2076 self.ribs[ValueNS].push(Rib::new(ItemRibKind));
2077 self.ribs[TypeNS].push(Rib::new(ItemRibKind));
2079 self.ribs[TypeNS].pop();
2080 self.ribs[ValueNS].pop();
2083 fn with_constant_rib<F>(&mut self, f: F)
2084 where F: FnOnce(&mut Resolver)
2086 self.ribs[ValueNS].push(Rib::new(ConstantItemRibKind));
2088 self.ribs[ValueNS].pop();
2091 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2092 where F: FnOnce(&mut Resolver) -> T
2094 // Handle nested impls (inside fn bodies)
2095 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2096 let result = f(self);
2097 self.current_self_type = previous_value;
2101 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
2102 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2104 let mut new_val = None;
2105 let mut new_id = None;
2106 if let Some(trait_ref) = opt_trait_ref {
2107 let path: Vec<_> = trait_ref.path.segments.iter()
2108 .map(|seg| respan(seg.span, seg.identifier))
2110 let def = self.smart_resolve_path_fragment(trait_ref.ref_id,
2113 trait_ref.path.span,
2114 trait_ref.path.segments.last().unwrap().span,
2115 PathSource::Trait(AliasPossibility::No))
2117 if def != Def::Err {
2118 new_id = Some(def.def_id());
2119 let span = trait_ref.path.span;
2120 if let PathResult::Module(module) = self.resolve_path(&path, None, false, span) {
2121 new_val = Some((module, trait_ref.clone()));
2125 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2126 let result = f(self, new_id);
2127 self.current_trait_ref = original_trait_ref;
2131 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2132 where F: FnOnce(&mut Resolver)
2134 let mut self_type_rib = Rib::new(NormalRibKind);
2136 // plain insert (no renaming, types are not currently hygienic....)
2137 self_type_rib.bindings.insert(keywords::SelfType.ident(), self_def);
2138 self.ribs[TypeNS].push(self_type_rib);
2140 self.ribs[TypeNS].pop();
2143 fn resolve_implementation(&mut self,
2144 generics: &Generics,
2145 opt_trait_reference: &Option<TraitRef>,
2148 impl_items: &[ImplItem]) {
2149 // If applicable, create a rib for the type parameters.
2150 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2151 // Dummy self type for better errors if `Self` is used in the trait path.
2152 this.with_self_rib(Def::SelfTy(None, None), |this| {
2153 // Resolve the trait reference, if necessary.
2154 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2155 let item_def_id = this.definitions.local_def_id(item_id);
2156 this.with_self_rib(Def::SelfTy(trait_id, Some(item_def_id)), |this| {
2157 if let Some(trait_ref) = opt_trait_reference.as_ref() {
2158 // Resolve type arguments in trait path
2159 visit::walk_trait_ref(this, trait_ref);
2161 // Resolve the self type.
2162 this.visit_ty(self_type);
2163 // Resolve the type parameters.
2164 this.visit_generics(generics);
2165 this.with_current_self_type(self_type, |this| {
2166 for impl_item in impl_items {
2167 this.check_proc_macro_attrs(&impl_item.attrs);
2168 this.resolve_visibility(&impl_item.vis);
2170 // We also need a new scope for the impl item type parameters.
2171 let type_parameters = HasTypeParameters(&impl_item.generics,
2172 TraitOrImplItemRibKind);
2173 this.with_type_parameter_rib(type_parameters, |this| {
2174 use self::ResolutionError::*;
2175 match impl_item.node {
2176 ImplItemKind::Const(..) => {
2177 // If this is a trait impl, ensure the const
2179 this.check_trait_item(impl_item.ident,
2182 |n, s| ConstNotMemberOfTrait(n, s));
2183 this.with_constant_rib(|this|
2184 visit::walk_impl_item(this, impl_item)
2187 ImplItemKind::Method(_, _) => {
2188 // If this is a trait impl, ensure the method
2190 this.check_trait_item(impl_item.ident,
2193 |n, s| MethodNotMemberOfTrait(n, s));
2195 visit::walk_impl_item(this, impl_item);
2197 ImplItemKind::Type(ref ty) => {
2198 // If this is a trait impl, ensure the type
2200 this.check_trait_item(impl_item.ident,
2203 |n, s| TypeNotMemberOfTrait(n, s));
2207 ImplItemKind::Macro(_) =>
2208 panic!("unexpanded macro in resolve!"),
2219 fn check_trait_item<F>(&mut self, ident: Ident, ns: Namespace, span: Span, err: F)
2220 where F: FnOnce(Name, &str) -> ResolutionError
2222 // If there is a TraitRef in scope for an impl, then the method must be in the
2224 if let Some((module, _)) = self.current_trait_ref {
2225 if self.resolve_ident_in_module(module, ident, ns, false, false, span).is_err() {
2226 let path = &self.current_trait_ref.as_ref().unwrap().1.path;
2227 resolve_error(self, span, err(ident.name, &path_names_to_string(path)));
2232 fn resolve_local(&mut self, local: &Local) {
2233 // Resolve the type.
2234 walk_list!(self, visit_ty, &local.ty);
2236 // Resolve the initializer.
2237 walk_list!(self, visit_expr, &local.init);
2239 // Resolve the pattern.
2240 self.resolve_pattern(&local.pat, PatternSource::Let, &mut FxHashMap());
2243 // build a map from pattern identifiers to binding-info's.
2244 // this is done hygienically. This could arise for a macro
2245 // that expands into an or-pattern where one 'x' was from the
2246 // user and one 'x' came from the macro.
2247 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2248 let mut binding_map = FxHashMap();
2250 pat.walk(&mut |pat| {
2251 if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node {
2252 if sub_pat.is_some() || match self.def_map.get(&pat.id).map(|res| res.base_def()) {
2253 Some(Def::Local(..)) => true,
2256 let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode };
2257 binding_map.insert(ident.node, binding_info);
2266 // check that all of the arms in an or-pattern have exactly the
2267 // same set of bindings, with the same binding modes for each.
2268 fn check_consistent_bindings(&mut self, arm: &Arm) {
2269 if arm.pats.is_empty() {
2273 let mut missing_vars = FxHashMap();
2274 let mut inconsistent_vars = FxHashMap();
2275 for (i, p) in arm.pats.iter().enumerate() {
2276 let map_i = self.binding_mode_map(&p);
2278 for (j, q) in arm.pats.iter().enumerate() {
2283 let map_j = self.binding_mode_map(&q);
2284 for (&key, &binding_i) in &map_i {
2285 if map_j.len() == 0 { // Account for missing bindings when
2286 let binding_error = missing_vars // map_j has none.
2288 .or_insert(BindingError {
2290 origin: BTreeSet::new(),
2291 target: BTreeSet::new(),
2293 binding_error.origin.insert(binding_i.span);
2294 binding_error.target.insert(q.span);
2296 for (&key_j, &binding_j) in &map_j {
2297 match map_i.get(&key_j) {
2298 None => { // missing binding
2299 let binding_error = missing_vars
2301 .or_insert(BindingError {
2303 origin: BTreeSet::new(),
2304 target: BTreeSet::new(),
2306 binding_error.origin.insert(binding_j.span);
2307 binding_error.target.insert(p.span);
2309 Some(binding_i) => { // check consistent binding
2310 if binding_i.binding_mode != binding_j.binding_mode {
2313 .or_insert((binding_j.span, binding_i.span));
2321 let mut missing_vars = missing_vars.iter().collect::<Vec<_>>();
2322 missing_vars.sort();
2323 for (_, v) in missing_vars {
2325 *v.origin.iter().next().unwrap(),
2326 ResolutionError::VariableNotBoundInPattern(v));
2328 let mut inconsistent_vars = inconsistent_vars.iter().collect::<Vec<_>>();
2329 inconsistent_vars.sort();
2330 for (name, v) in inconsistent_vars {
2331 resolve_error(self, v.0, ResolutionError::VariableBoundWithDifferentMode(*name, v.1));
2335 fn resolve_arm(&mut self, arm: &Arm) {
2336 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2338 let mut bindings_list = FxHashMap();
2339 for pattern in &arm.pats {
2340 self.resolve_pattern(&pattern, PatternSource::Match, &mut bindings_list);
2343 // This has to happen *after* we determine which
2344 // pat_idents are variants
2345 self.check_consistent_bindings(arm);
2347 walk_list!(self, visit_expr, &arm.guard);
2348 self.visit_expr(&arm.body);
2350 self.ribs[ValueNS].pop();
2353 fn resolve_block(&mut self, block: &Block) {
2354 debug!("(resolving block) entering block");
2355 // Move down in the graph, if there's an anonymous module rooted here.
2356 let orig_module = self.current_module;
2357 let anonymous_module = self.block_map.get(&block.id).cloned(); // clones a reference
2359 let mut num_macro_definition_ribs = 0;
2360 if let Some(anonymous_module) = anonymous_module {
2361 debug!("(resolving block) found anonymous module, moving down");
2362 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2363 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2364 self.current_module = anonymous_module;
2365 self.finalize_current_module_macro_resolutions();
2367 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2370 // Descend into the block.
2371 for stmt in &block.stmts {
2372 if let ast::StmtKind::Item(ref item) = stmt.node {
2373 if let ast::ItemKind::MacroDef(..) = item.node {
2374 num_macro_definition_ribs += 1;
2375 let def = self.definitions.local_def_id(item.id);
2376 self.ribs[ValueNS].push(Rib::new(MacroDefinition(def)));
2377 self.label_ribs.push(Rib::new(MacroDefinition(def)));
2381 self.visit_stmt(stmt);
2385 self.current_module = orig_module;
2386 for _ in 0 .. num_macro_definition_ribs {
2387 self.ribs[ValueNS].pop();
2388 self.label_ribs.pop();
2390 self.ribs[ValueNS].pop();
2391 if let Some(_) = anonymous_module {
2392 self.ribs[TypeNS].pop();
2394 debug!("(resolving block) leaving block");
2397 fn fresh_binding(&mut self,
2398 ident: &SpannedIdent,
2400 outer_pat_id: NodeId,
2401 pat_src: PatternSource,
2402 bindings: &mut FxHashMap<Ident, NodeId>)
2404 // Add the binding to the local ribs, if it
2405 // doesn't already exist in the bindings map. (We
2406 // must not add it if it's in the bindings map
2407 // because that breaks the assumptions later
2408 // passes make about or-patterns.)
2409 let mut def = Def::Local(pat_id);
2410 match bindings.get(&ident.node).cloned() {
2411 Some(id) if id == outer_pat_id => {
2412 // `Variant(a, a)`, error
2416 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2417 &ident.node.name.as_str())
2420 Some(..) if pat_src == PatternSource::FnParam => {
2421 // `fn f(a: u8, a: u8)`, error
2425 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2426 &ident.node.name.as_str())
2429 Some(..) if pat_src == PatternSource::Match => {
2430 // `Variant1(a) | Variant2(a)`, ok
2431 // Reuse definition from the first `a`.
2432 def = self.ribs[ValueNS].last_mut().unwrap().bindings[&ident.node];
2435 span_bug!(ident.span, "two bindings with the same name from \
2436 unexpected pattern source {:?}", pat_src);
2439 // A completely fresh binding, add to the lists if it's valid.
2440 if ident.node.name != keywords::Invalid.name() {
2441 bindings.insert(ident.node, outer_pat_id);
2442 self.ribs[ValueNS].last_mut().unwrap().bindings.insert(ident.node, def);
2447 PathResolution::new(def)
2450 fn resolve_pattern(&mut self,
2452 pat_src: PatternSource,
2453 // Maps idents to the node ID for the
2454 // outermost pattern that binds them.
2455 bindings: &mut FxHashMap<Ident, NodeId>) {
2456 // Visit all direct subpatterns of this pattern.
2457 let outer_pat_id = pat.id;
2458 pat.walk(&mut |pat| {
2460 PatKind::Ident(bmode, ref ident, ref opt_pat) => {
2461 // First try to resolve the identifier as some existing
2462 // entity, then fall back to a fresh binding.
2463 let binding = self.resolve_ident_in_lexical_scope(ident.node, ValueNS,
2465 .and_then(LexicalScopeBinding::item);
2466 let resolution = binding.map(NameBinding::def).and_then(|def| {
2467 let is_syntactic_ambiguity = opt_pat.is_none() &&
2468 bmode == BindingMode::ByValue(Mutability::Immutable);
2470 Def::StructCtor(_, CtorKind::Const) |
2471 Def::VariantCtor(_, CtorKind::Const) |
2472 Def::Const(..) if is_syntactic_ambiguity => {
2473 // Disambiguate in favor of a unit struct/variant
2474 // or constant pattern.
2475 self.record_use(ident.node, ValueNS, binding.unwrap(), ident.span);
2476 Some(PathResolution::new(def))
2478 Def::StructCtor(..) | Def::VariantCtor(..) |
2479 Def::Const(..) | Def::Static(..) => {
2480 // This is unambiguously a fresh binding, either syntactically
2481 // (e.g. `IDENT @ PAT` or `ref IDENT`) or because `IDENT` resolves
2482 // to something unusable as a pattern (e.g. constructor function),
2483 // but we still conservatively report an error, see
2484 // issues/33118#issuecomment-233962221 for one reason why.
2488 ResolutionError::BindingShadowsSomethingUnacceptable(
2489 pat_src.descr(), ident.node.name, binding.unwrap())
2493 Def::Fn(..) | Def::Err => {
2494 // These entities are explicitly allowed
2495 // to be shadowed by fresh bindings.
2499 span_bug!(ident.span, "unexpected definition for an \
2500 identifier in pattern: {:?}", def);
2503 }).unwrap_or_else(|| {
2504 self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings)
2507 self.record_def(pat.id, resolution);
2510 PatKind::TupleStruct(ref path, ..) => {
2511 self.smart_resolve_path(pat.id, None, path, PathSource::TupleStruct);
2514 PatKind::Path(ref qself, ref path) => {
2515 self.smart_resolve_path(pat.id, qself.as_ref(), path, PathSource::Pat);
2518 PatKind::Struct(ref path, ..) => {
2519 self.smart_resolve_path(pat.id, None, path, PathSource::Struct);
2527 visit::walk_pat(self, pat);
2530 // High-level and context dependent path resolution routine.
2531 // Resolves the path and records the resolution into definition map.
2532 // If resolution fails tries several techniques to find likely
2533 // resolution candidates, suggest imports or other help, and report
2534 // errors in user friendly way.
2535 fn smart_resolve_path(&mut self,
2537 qself: Option<&QSelf>,
2541 let segments = &path.segments.iter()
2542 .map(|seg| respan(seg.span, seg.identifier))
2543 .collect::<Vec<_>>();
2544 let ident_span = path.segments.last().map_or(path.span, |seg| seg.span);
2545 self.smart_resolve_path_fragment(id, qself, segments, path.span, ident_span, source)
2548 fn smart_resolve_path_fragment(&mut self,
2550 qself: Option<&QSelf>,
2551 path: &[SpannedIdent],
2556 let ns = source.namespace();
2557 let is_expected = &|def| source.is_expected(def);
2558 let is_enum_variant = &|def| if let Def::Variant(..) = def { true } else { false };
2560 // Base error is amended with one short label and possibly some longer helps/notes.
2561 let report_errors = |this: &mut Self, def: Option<Def>| {
2562 // Make the base error.
2563 let expected = source.descr_expected();
2564 let path_str = names_to_string(path);
2565 let code = source.error_code(def.is_some());
2566 let (base_msg, fallback_label, base_span) = if let Some(def) = def {
2567 (format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str),
2568 format!("not a {}", expected), span)
2570 let item_str = path[path.len() - 1].node;
2571 let item_span = path[path.len() - 1].span;
2572 let (mod_prefix, mod_str) = if path.len() == 1 {
2573 (format!(""), format!("this scope"))
2574 } else if path.len() == 2 && path[0].node.name == keywords::CrateRoot.name() {
2575 (format!(""), format!("the crate root"))
2577 let mod_path = &path[..path.len() - 1];
2578 let mod_prefix = match this.resolve_path(mod_path, Some(TypeNS), false, span) {
2579 PathResult::Module(module) => module.def(),
2581 }.map_or(format!(""), |def| format!("{} ", def.kind_name()));
2582 (mod_prefix, format!("`{}`", names_to_string(mod_path)))
2584 (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str),
2585 format!("not found in {}", mod_str), item_span)
2587 let code = DiagnosticId::Error(code.into());
2588 let mut err = this.session.struct_span_err_with_code(base_span, &base_msg, code);
2590 // Emit special messages for unresolved `Self` and `self`.
2591 if is_self_type(path, ns) {
2592 __diagnostic_used!(E0411);
2593 err.code(DiagnosticId::Error("E0411".into()));
2594 err.span_label(span, "`Self` is only available in traits and impls");
2595 return (err, Vec::new());
2597 if is_self_value(path, ns) {
2598 __diagnostic_used!(E0424);
2599 err.code(DiagnosticId::Error("E0424".into()));
2600 err.span_label(span, format!("`self` value is only available in \
2601 methods with `self` parameter"));
2602 return (err, Vec::new());
2605 // Try to lookup the name in more relaxed fashion for better error reporting.
2606 let ident = *path.last().unwrap();
2607 let candidates = this.lookup_import_candidates(ident.node.name, ns, is_expected);
2608 if candidates.is_empty() && is_expected(Def::Enum(DefId::local(CRATE_DEF_INDEX))) {
2609 let enum_candidates =
2610 this.lookup_import_candidates(ident.node.name, ns, is_enum_variant);
2611 let mut enum_candidates = enum_candidates.iter()
2612 .map(|suggestion| import_candidate_to_paths(&suggestion)).collect::<Vec<_>>();
2613 enum_candidates.sort();
2614 for (sp, variant_path, enum_path) in enum_candidates {
2616 let msg = format!("there is an enum variant `{}`, \
2622 err.span_suggestion(span, "you can try using the variant's enum",
2627 if path.len() == 1 && this.self_type_is_available(span) {
2628 if let Some(candidate) = this.lookup_assoc_candidate(ident.node, ns, is_expected) {
2629 let self_is_available = this.self_value_is_available(path[0].node.ctxt, span);
2631 AssocSuggestion::Field => {
2632 err.span_suggestion(span, "try",
2633 format!("self.{}", path_str));
2634 if !self_is_available {
2635 err.span_label(span, format!("`self` value is only available in \
2636 methods with `self` parameter"));
2639 AssocSuggestion::MethodWithSelf if self_is_available => {
2640 err.span_suggestion(span, "try",
2641 format!("self.{}", path_str));
2643 AssocSuggestion::MethodWithSelf | AssocSuggestion::AssocItem => {
2644 err.span_suggestion(span, "try",
2645 format!("Self::{}", path_str));
2648 return (err, candidates);
2652 let mut levenshtein_worked = false;
2655 if let Some(candidate) = this.lookup_typo_candidate(path, ns, is_expected, span) {
2656 err.span_label(ident_span, format!("did you mean `{}`?", candidate));
2657 levenshtein_worked = true;
2660 // Try context dependent help if relaxed lookup didn't work.
2661 if let Some(def) = def {
2662 match (def, source) {
2663 (Def::Macro(..), _) => {
2664 err.span_label(span, format!("did you mean `{}!(...)`?", path_str));
2665 return (err, candidates);
2667 (Def::TyAlias(..), PathSource::Trait(_)) => {
2668 err.span_label(span, "type aliases cannot be used for traits");
2669 return (err, candidates);
2671 (Def::Mod(..), PathSource::Expr(Some(parent))) => match parent.node {
2672 ExprKind::Field(_, ident) => {
2673 err.span_label(parent.span, format!("did you mean `{}::{}`?",
2674 path_str, ident.node));
2675 return (err, candidates);
2677 ExprKind::MethodCall(ref segment, ..) => {
2678 err.span_label(parent.span, format!("did you mean `{}::{}(...)`?",
2679 path_str, segment.identifier));
2680 return (err, candidates);
2684 (Def::Enum(..), PathSource::TupleStruct)
2685 | (Def::Enum(..), PathSource::Expr(..)) => {
2686 if let Some(variants) = this.collect_enum_variants(def) {
2687 err.note(&format!("did you mean to use one \
2688 of the following variants?\n{}",
2690 .map(|suggestion| path_names_to_string(suggestion))
2691 .map(|suggestion| format!("- `{}`", suggestion))
2692 .collect::<Vec<_>>()
2696 err.note("did you mean to use one of the enum's variants?");
2698 return (err, candidates);
2700 _ if ns == ValueNS && is_struct_like(def) => {
2701 if let Def::Struct(def_id) = def {
2702 if let Some((ctor_def, ctor_vis))
2703 = this.struct_constructors.get(&def_id).cloned() {
2704 if is_expected(ctor_def) && !this.is_accessible(ctor_vis) {
2705 err.span_label(span, format!("constructor is not visible \
2706 here due to private fields"));
2710 err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?",
2712 return (err, candidates);
2719 if !levenshtein_worked {
2720 err.span_label(base_span, fallback_label);
2721 this.type_ascription_suggestion(&mut err, base_span);
2725 let report_errors = |this: &mut Self, def: Option<Def>| {
2726 let (err, candidates) = report_errors(this, def);
2727 let def_id = this.current_module.normal_ancestor_id;
2728 let node_id = this.definitions.as_local_node_id(def_id).unwrap();
2729 let better = def.is_some();
2730 this.use_injections.push(UseError { err, candidates, node_id, better });
2731 err_path_resolution()
2734 let resolution = match self.resolve_qpath_anywhere(id, qself, path, ns, span,
2735 source.defer_to_typeck(),
2736 source.global_by_default()) {
2737 Some(resolution) if resolution.unresolved_segments() == 0 => {
2738 if is_expected(resolution.base_def()) || resolution.base_def() == Def::Err {
2741 // Add a temporary hack to smooth the transition to new struct ctor
2742 // visibility rules. See #38932 for more details.
2744 if let Def::Struct(def_id) = resolution.base_def() {
2745 if let Some((ctor_def, ctor_vis))
2746 = self.struct_constructors.get(&def_id).cloned() {
2747 if is_expected(ctor_def) && self.is_accessible(ctor_vis) {
2748 let lint = lint::builtin::LEGACY_CONSTRUCTOR_VISIBILITY;
2749 self.session.buffer_lint(lint, id, span,
2750 "private struct constructors are not usable through \
2751 reexports in outer modules",
2753 res = Some(PathResolution::new(ctor_def));
2758 res.unwrap_or_else(|| report_errors(self, Some(resolution.base_def())))
2761 Some(resolution) if source.defer_to_typeck() => {
2762 // Not fully resolved associated item `T::A::B` or `<T as Tr>::A::B`
2763 // or `<T>::A::B`. If `B` should be resolved in value namespace then
2764 // it needs to be added to the trait map.
2766 let item_name = path.last().unwrap().node;
2767 let traits = self.get_traits_containing_item(item_name, ns);
2768 self.trait_map.insert(id, traits);
2772 _ => report_errors(self, None)
2775 if let PathSource::TraitItem(..) = source {} else {
2776 // Avoid recording definition of `A::B` in `<T as A>::B::C`.
2777 self.record_def(id, resolution);
2782 fn type_ascription_suggestion(&self,
2783 err: &mut DiagnosticBuilder,
2785 debug!("type_ascription_suggetion {:?}", base_span);
2786 let cm = self.session.codemap();
2787 debug!("self.current_type_ascription {:?}", self.current_type_ascription);
2788 if let Some(sp) = self.current_type_ascription.last() {
2790 loop { // try to find the `:`, bail on first non-':'/non-whitespace
2791 sp = sp.next_point();
2792 if let Ok(snippet) = cm.span_to_snippet(sp.to(sp.next_point())) {
2793 debug!("snippet {:?}", snippet);
2794 let line_sp = cm.lookup_char_pos(sp.hi()).line;
2795 let line_base_sp = cm.lookup_char_pos(base_span.lo()).line;
2796 debug!("{:?} {:?}", line_sp, line_base_sp);
2798 err.span_label(base_span,
2799 "expecting a type here because of type ascription");
2800 if line_sp != line_base_sp {
2801 err.span_suggestion_short(sp,
2802 "did you mean to use `;` here instead?",
2806 } else if snippet.trim().len() != 0 {
2807 debug!("tried to find type ascription `:` token, couldn't find it");
2817 fn self_type_is_available(&mut self, span: Span) -> bool {
2818 let binding = self.resolve_ident_in_lexical_scope(keywords::SelfType.ident(),
2819 TypeNS, false, span);
2820 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
2823 fn self_value_is_available(&mut self, ctxt: SyntaxContext, span: Span) -> bool {
2824 let ident = Ident { name: keywords::SelfValue.name(), ctxt: ctxt };
2825 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, false, span);
2826 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
2829 // Resolve in alternative namespaces if resolution in the primary namespace fails.
2830 fn resolve_qpath_anywhere(&mut self,
2832 qself: Option<&QSelf>,
2833 path: &[SpannedIdent],
2834 primary_ns: Namespace,
2836 defer_to_typeck: bool,
2837 global_by_default: bool)
2838 -> Option<PathResolution> {
2839 let mut fin_res = None;
2840 // FIXME: can't resolve paths in macro namespace yet, macros are
2841 // processed by the little special hack below.
2842 for (i, ns) in [primary_ns, TypeNS, ValueNS, /*MacroNS*/].iter().cloned().enumerate() {
2843 if i == 0 || ns != primary_ns {
2844 match self.resolve_qpath(id, qself, path, ns, span, global_by_default) {
2845 // If defer_to_typeck, then resolution > no resolution,
2846 // otherwise full resolution > partial resolution > no resolution.
2847 Some(res) if res.unresolved_segments() == 0 || defer_to_typeck =>
2849 res => if fin_res.is_none() { fin_res = res },
2853 let is_global = self.global_macros.get(&path[0].node.name).cloned()
2854 .map(|binding| binding.get_macro(self).kind() == MacroKind::Bang).unwrap_or(false);
2855 if primary_ns != MacroNS && (is_global ||
2856 self.macro_names.contains(&path[0].node.modern())) {
2857 // Return some dummy definition, it's enough for error reporting.
2859 PathResolution::new(Def::Macro(DefId::local(CRATE_DEF_INDEX), MacroKind::Bang))
2865 /// Handles paths that may refer to associated items.
2866 fn resolve_qpath(&mut self,
2868 qself: Option<&QSelf>,
2869 path: &[SpannedIdent],
2872 global_by_default: bool)
2873 -> Option<PathResolution> {
2874 if let Some(qself) = qself {
2875 if qself.position == 0 {
2876 // FIXME: Create some fake resolution that can't possibly be a type.
2877 return Some(PathResolution::with_unresolved_segments(
2878 Def::Mod(DefId::local(CRATE_DEF_INDEX)), path.len()
2881 // Make sure `A::B` in `<T as A>::B::C` is a trait item.
2882 let ns = if qself.position + 1 == path.len() { ns } else { TypeNS };
2883 let res = self.smart_resolve_path_fragment(id, None, &path[..qself.position + 1],
2884 span, span, PathSource::TraitItem(ns));
2885 return Some(PathResolution::with_unresolved_segments(
2886 res.base_def(), res.unresolved_segments() + path.len() - qself.position - 1
2890 let result = match self.resolve_path(&path, Some(ns), true, span) {
2891 PathResult::NonModule(path_res) => path_res,
2892 PathResult::Module(module) if !module.is_normal() => {
2893 PathResolution::new(module.def().unwrap())
2895 // In `a(::assoc_item)*` `a` cannot be a module. If `a` does resolve to a module we
2896 // don't report an error right away, but try to fallback to a primitive type.
2897 // So, we are still able to successfully resolve something like
2899 // use std::u8; // bring module u8 in scope
2900 // fn f() -> u8 { // OK, resolves to primitive u8, not to std::u8
2901 // u8::max_value() // OK, resolves to associated function <u8>::max_value,
2902 // // not to non-existent std::u8::max_value
2905 // Such behavior is required for backward compatibility.
2906 // The same fallback is used when `a` resolves to nothing.
2907 PathResult::Module(..) | PathResult::Failed(..)
2908 if (ns == TypeNS || path.len() > 1) &&
2909 self.primitive_type_table.primitive_types
2910 .contains_key(&path[0].node.name) => {
2911 let prim = self.primitive_type_table.primitive_types[&path[0].node.name];
2913 TyUint(UintTy::U128) | TyInt(IntTy::I128) => {
2914 if !self.session.features.borrow().i128_type {
2915 emit_feature_err(&self.session.parse_sess,
2916 "i128_type", span, GateIssue::Language,
2917 "128-bit type is unstable");
2923 PathResolution::with_unresolved_segments(Def::PrimTy(prim), path.len() - 1)
2925 PathResult::Module(module) => PathResolution::new(module.def().unwrap()),
2926 PathResult::Failed(span, msg, false) => {
2927 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
2928 err_path_resolution()
2930 PathResult::Failed(..) => return None,
2931 PathResult::Indeterminate => bug!("indetermined path result in resolve_qpath"),
2934 if path.len() > 1 && !global_by_default && result.base_def() != Def::Err &&
2935 path[0].node.name != keywords::CrateRoot.name() &&
2936 path[0].node.name != keywords::DollarCrate.name() {
2937 let unqualified_result = {
2938 match self.resolve_path(&[*path.last().unwrap()], Some(ns), false, span) {
2939 PathResult::NonModule(path_res) => path_res.base_def(),
2940 PathResult::Module(module) => module.def().unwrap(),
2941 _ => return Some(result),
2944 if result.base_def() == unqualified_result {
2945 let lint = lint::builtin::UNUSED_QUALIFICATIONS;
2946 self.session.buffer_lint(lint, id, span, "unnecessary qualification")
2953 fn resolve_path(&mut self,
2954 path: &[SpannedIdent],
2955 opt_ns: Option<Namespace>, // `None` indicates a module path
2959 let mut module = None;
2960 let mut allow_super = true;
2962 for (i, &ident) in path.iter().enumerate() {
2963 debug!("resolve_path ident {} {:?}", i, ident);
2964 let is_last = i == path.len() - 1;
2965 let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
2966 let name = ident.node.name;
2968 if i == 0 && ns == TypeNS && name == keywords::SelfValue.name() {
2969 let mut ctxt = ident.node.ctxt.modern();
2970 module = Some(self.resolve_self(&mut ctxt, self.current_module));
2972 } else if allow_super && ns == TypeNS && name == keywords::Super.name() {
2973 let mut ctxt = ident.node.ctxt.modern();
2974 let self_module = match i {
2975 0 => self.resolve_self(&mut ctxt, self.current_module),
2976 _ => module.unwrap(),
2978 if let Some(parent) = self_module.parent {
2979 module = Some(self.resolve_self(&mut ctxt, parent));
2982 let msg = "There are too many initial `super`s.".to_string();
2983 return PathResult::Failed(ident.span, msg, false);
2985 } else if i == 0 && ns == TypeNS && name == keywords::Extern.name() {
2988 allow_super = false;
2991 if (i == 0 && name == keywords::CrateRoot.name()) ||
2992 (i == 1 && name == keywords::Crate.name() &&
2993 path[0].node.name == keywords::CrateRoot.name()) {
2994 // `::a::b` or `::crate::a::b`
2995 module = Some(self.resolve_crate_root(ident.node.ctxt.modern()));
2997 } else if i == 0 && name == keywords::DollarCrate.name() {
2999 module = Some(self.resolve_crate_root(ident.node.ctxt));
3001 } else if i == 1 && !token::Ident(ident.node).is_path_segment_keyword() {
3002 let prev_name = path[0].node.name;
3003 if prev_name == keywords::Extern.name() ||
3004 prev_name == keywords::CrateRoot.name() &&
3005 self.session.features.borrow().extern_absolute_paths {
3006 // `::extern_crate::a::b`
3007 let crate_id = self.crate_loader.resolve_crate_from_path(name, ident.span);
3009 self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
3010 self.populate_module_if_necessary(crate_root);
3011 module = Some(crate_root);
3017 // Report special messages for path segment keywords in wrong positions.
3018 if name == keywords::CrateRoot.name() && i != 0 ||
3019 name == keywords::DollarCrate.name() && i != 0 ||
3020 name == keywords::SelfValue.name() && i != 0 ||
3021 name == keywords::SelfType.name() && i != 0 ||
3022 name == keywords::Super.name() && i != 0 ||
3023 name == keywords::Extern.name() && i != 0 ||
3024 name == keywords::Crate.name() && i != 1 &&
3025 path[0].node.name != keywords::CrateRoot.name() {
3026 let name_str = if name == keywords::CrateRoot.name() {
3027 format!("crate root")
3029 format!("`{}`", name)
3031 let msg = if i == 1 && path[0].node.name == keywords::CrateRoot.name() {
3032 format!("global paths cannot start with {}", name_str)
3033 } else if i == 0 && name == keywords::Crate.name() {
3034 format!("{} can only be used in absolute paths", name_str)
3036 format!("{} in paths can only be used in start position", name_str)
3038 return PathResult::Failed(ident.span, msg, false);
3041 let binding = if let Some(module) = module {
3042 self.resolve_ident_in_module(module, ident.node, ns, false, record_used, path_span)
3043 } else if opt_ns == Some(MacroNS) {
3044 self.resolve_lexical_macro_path_segment(ident.node, ns, record_used, path_span)
3045 .map(MacroBinding::binding)
3047 match self.resolve_ident_in_lexical_scope(ident.node, ns, record_used, path_span) {
3048 Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
3049 Some(LexicalScopeBinding::Def(def))
3050 if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) => {
3051 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3055 _ => Err(if record_used { Determined } else { Undetermined }),
3061 let def = binding.def();
3062 let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(def);
3063 if let Some(next_module) = binding.module() {
3064 module = Some(next_module);
3065 } else if def == Def::Err {
3066 return PathResult::NonModule(err_path_resolution());
3067 } else if opt_ns.is_some() && (is_last || maybe_assoc) {
3068 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3069 def, path.len() - i - 1
3072 return PathResult::Failed(ident.span,
3073 format!("Not a module `{}`", ident.node),
3077 Err(Undetermined) => return PathResult::Indeterminate,
3078 Err(Determined) => {
3079 if let Some(module) = module {
3080 if opt_ns.is_some() && !module.is_normal() {
3081 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3082 module.def().unwrap(), path.len() - i
3086 let msg = if module.and_then(ModuleData::def) == self.graph_root.def() {
3087 let is_mod = |def| match def { Def::Mod(..) => true, _ => false };
3088 let mut candidates =
3089 self.lookup_import_candidates(name, TypeNS, is_mod);
3090 candidates.sort_by_key(|c| (c.path.segments.len(), c.path.to_string()));
3091 if let Some(candidate) = candidates.get(0) {
3092 format!("Did you mean `{}`?", candidate.path)
3094 format!("Maybe a missing `extern crate {};`?", ident.node)
3097 format!("Use of undeclared type or module `{}`", ident.node)
3099 format!("Could not find `{}` in `{}`", ident.node, path[i - 1].node)
3101 return PathResult::Failed(ident.span, msg, is_last);
3106 PathResult::Module(module.unwrap_or(self.graph_root))
3109 // Resolve a local definition, potentially adjusting for closures.
3110 fn adjust_local_def(&mut self,
3115 span: Span) -> Def {
3116 let ribs = &self.ribs[ns][rib_index + 1..];
3118 // An invalid forward use of a type parameter from a previous default.
3119 if let ForwardTyParamBanRibKind = self.ribs[ns][rib_index].kind {
3121 resolve_error(self, span, ResolutionError::ForwardDeclaredTyParam);
3123 assert_eq!(def, Def::Err);
3129 span_bug!(span, "unexpected {:?} in bindings", def)
3131 Def::Local(node_id) => {
3134 NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) |
3135 ForwardTyParamBanRibKind => {
3136 // Nothing to do. Continue.
3138 ClosureRibKind(function_id) => {
3141 let seen = self.freevars_seen
3143 .or_insert_with(|| NodeMap());
3144 if let Some(&index) = seen.get(&node_id) {
3145 def = Def::Upvar(node_id, index, function_id);
3148 let vec = self.freevars
3150 .or_insert_with(|| vec![]);
3151 let depth = vec.len();
3152 def = Def::Upvar(node_id, depth, function_id);
3159 seen.insert(node_id, depth);
3162 ItemRibKind | TraitOrImplItemRibKind => {
3163 // This was an attempt to access an upvar inside a
3164 // named function item. This is not allowed, so we
3167 resolve_error(self, span,
3168 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
3172 ConstantItemRibKind => {
3173 // Still doesn't deal with upvars
3175 resolve_error(self, span,
3176 ResolutionError::AttemptToUseNonConstantValueInConstant);
3183 Def::TyParam(..) | Def::SelfTy(..) => {
3186 NormalRibKind | TraitOrImplItemRibKind | ClosureRibKind(..) |
3187 ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind |
3188 ConstantItemRibKind => {
3189 // Nothing to do. Continue.
3192 // This was an attempt to use a type parameter outside
3195 resolve_error(self, span,
3196 ResolutionError::TypeParametersFromOuterFunction);
3208 fn lookup_assoc_candidate<FilterFn>(&mut self,
3211 filter_fn: FilterFn)
3212 -> Option<AssocSuggestion>
3213 where FilterFn: Fn(Def) -> bool
3215 fn extract_node_id(t: &Ty) -> Option<NodeId> {
3217 TyKind::Path(None, _) => Some(t.id),
3218 TyKind::Rptr(_, ref mut_ty) => extract_node_id(&mut_ty.ty),
3219 // This doesn't handle the remaining `Ty` variants as they are not
3220 // that commonly the self_type, it might be interesting to provide
3221 // support for those in future.
3226 // Fields are generally expected in the same contexts as locals.
3227 if filter_fn(Def::Local(ast::DUMMY_NODE_ID)) {
3228 if let Some(node_id) = self.current_self_type.as_ref().and_then(extract_node_id) {
3229 // Look for a field with the same name in the current self_type.
3230 if let Some(resolution) = self.def_map.get(&node_id) {
3231 match resolution.base_def() {
3232 Def::Struct(did) | Def::Union(did)
3233 if resolution.unresolved_segments() == 0 => {
3234 if let Some(field_names) = self.field_names.get(&did) {
3235 if field_names.iter().any(|&field_name| ident.name == field_name) {
3236 return Some(AssocSuggestion::Field);
3246 // Look for associated items in the current trait.
3247 if let Some((module, _)) = self.current_trait_ref {
3248 if let Ok(binding) =
3249 self.resolve_ident_in_module(module, ident, ns, false, false, module.span) {
3250 let def = binding.def();
3252 return Some(if self.has_self.contains(&def.def_id()) {
3253 AssocSuggestion::MethodWithSelf
3255 AssocSuggestion::AssocItem
3264 fn lookup_typo_candidate<FilterFn>(&mut self,
3265 path: &[SpannedIdent],
3267 filter_fn: FilterFn,
3270 where FilterFn: Fn(Def) -> bool
3272 let add_module_candidates = |module: Module, names: &mut Vec<Name>| {
3273 for (&(ident, _), resolution) in module.resolutions.borrow().iter() {
3274 if let Some(binding) = resolution.borrow().binding {
3275 if filter_fn(binding.def()) {
3276 names.push(ident.name);
3282 let mut names = Vec::new();
3283 if path.len() == 1 {
3284 // Search in lexical scope.
3285 // Walk backwards up the ribs in scope and collect candidates.
3286 for rib in self.ribs[ns].iter().rev() {
3287 // Locals and type parameters
3288 for (ident, def) in &rib.bindings {
3289 if filter_fn(*def) {
3290 names.push(ident.name);
3294 if let ModuleRibKind(module) = rib.kind {
3295 // Items from this module
3296 add_module_candidates(module, &mut names);
3298 if let ModuleKind::Block(..) = module.kind {
3299 // We can see through blocks
3301 // Items from the prelude
3302 if let Some(prelude) = self.prelude {
3303 if !module.no_implicit_prelude {
3304 add_module_candidates(prelude, &mut names);
3311 // Add primitive types to the mix
3312 if filter_fn(Def::PrimTy(TyBool)) {
3313 for (name, _) in &self.primitive_type_table.primitive_types {
3318 // Search in module.
3319 let mod_path = &path[..path.len() - 1];
3320 if let PathResult::Module(module) = self.resolve_path(mod_path, Some(TypeNS),
3322 add_module_candidates(module, &mut names);
3326 let name = path[path.len() - 1].node.name;
3327 // Make sure error reporting is deterministic.
3328 names.sort_by_key(|name| name.as_str());
3329 match find_best_match_for_name(names.iter(), &name.as_str(), None) {
3330 Some(found) if found != name => Some(found),
3335 fn with_resolved_label<F>(&mut self, label: Option<SpannedIdent>, id: NodeId, f: F)
3336 where F: FnOnce(&mut Resolver)
3338 if let Some(label) = label {
3339 let def = Def::Label(id);
3340 self.with_label_rib(|this| {
3341 this.label_ribs.last_mut().unwrap().bindings.insert(label.node, def);
3349 fn resolve_labeled_block(&mut self, label: Option<SpannedIdent>, id: NodeId, block: &Block) {
3350 self.with_resolved_label(label, id, |this| this.visit_block(block));
3353 fn resolve_expr(&mut self, expr: &Expr, parent: Option<&Expr>) {
3354 // First, record candidate traits for this expression if it could
3355 // result in the invocation of a method call.
3357 self.record_candidate_traits_for_expr_if_necessary(expr);
3359 // Next, resolve the node.
3361 ExprKind::Path(ref qself, ref path) => {
3362 self.smart_resolve_path(expr.id, qself.as_ref(), path, PathSource::Expr(parent));
3363 visit::walk_expr(self, expr);
3366 ExprKind::Struct(ref path, ..) => {
3367 self.smart_resolve_path(expr.id, None, path, PathSource::Struct);
3368 visit::walk_expr(self, expr);
3371 ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => {
3372 match self.search_label(label.node, |rib, id| rib.bindings.get(&id).cloned()) {
3374 // Search again for close matches...
3375 // Picks the first label that is "close enough", which is not necessarily
3376 // the closest match
3377 let close_match = self.search_label(label.node, |rib, ident| {
3378 let names = rib.bindings.iter().map(|(id, _)| &id.name);
3379 find_best_match_for_name(names, &*ident.name.as_str(), None)
3381 self.record_def(expr.id, err_path_resolution());
3384 ResolutionError::UndeclaredLabel(&label.node.name.as_str(),
3387 Some(def @ Def::Label(_)) => {
3388 // Since this def is a label, it is never read.
3389 self.record_def(expr.id, PathResolution::new(def));
3392 span_bug!(expr.span, "label wasn't mapped to a label def!");
3396 // visit `break` argument if any
3397 visit::walk_expr(self, expr);
3400 ExprKind::IfLet(ref pattern, ref subexpression, ref if_block, ref optional_else) => {
3401 self.visit_expr(subexpression);
3403 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
3404 self.resolve_pattern(pattern, PatternSource::IfLet, &mut FxHashMap());
3405 self.visit_block(if_block);
3406 self.ribs[ValueNS].pop();
3408 optional_else.as_ref().map(|expr| self.visit_expr(expr));
3411 ExprKind::Loop(ref block, label) => self.resolve_labeled_block(label, expr.id, &block),
3413 ExprKind::While(ref subexpression, ref block, label) => {
3414 self.with_resolved_label(label, expr.id, |this| {
3415 this.visit_expr(subexpression);
3416 this.visit_block(block);
3420 ExprKind::WhileLet(ref pattern, ref subexpression, ref block, label) => {
3421 self.with_resolved_label(label, expr.id, |this| {
3422 this.visit_expr(subexpression);
3423 this.ribs[ValueNS].push(Rib::new(NormalRibKind));
3424 this.resolve_pattern(pattern, PatternSource::WhileLet, &mut FxHashMap());
3425 this.visit_block(block);
3426 this.ribs[ValueNS].pop();
3430 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, label) => {
3431 self.visit_expr(subexpression);
3432 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
3433 self.resolve_pattern(pattern, PatternSource::For, &mut FxHashMap());
3435 self.resolve_labeled_block(label, expr.id, block);
3437 self.ribs[ValueNS].pop();
3440 // Equivalent to `visit::walk_expr` + passing some context to children.
3441 ExprKind::Field(ref subexpression, _) => {
3442 self.resolve_expr(subexpression, Some(expr));
3444 ExprKind::MethodCall(ref segment, ref arguments) => {
3445 let mut arguments = arguments.iter();
3446 self.resolve_expr(arguments.next().unwrap(), Some(expr));
3447 for argument in arguments {
3448 self.resolve_expr(argument, None);
3450 self.visit_path_segment(expr.span, segment);
3453 ExprKind::Repeat(ref element, ref count) => {
3454 self.visit_expr(element);
3455 self.with_constant_rib(|this| {
3456 this.visit_expr(count);
3459 ExprKind::Call(ref callee, ref arguments) => {
3460 self.resolve_expr(callee, Some(expr));
3461 for argument in arguments {
3462 self.resolve_expr(argument, None);
3465 ExprKind::Type(ref type_expr, _) => {
3466 self.current_type_ascription.push(type_expr.span);
3467 visit::walk_expr(self, expr);
3468 self.current_type_ascription.pop();
3471 visit::walk_expr(self, expr);
3476 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3478 ExprKind::Field(_, name) => {
3479 // FIXME(#6890): Even though you can't treat a method like a
3480 // field, we need to add any trait methods we find that match
3481 // the field name so that we can do some nice error reporting
3482 // later on in typeck.
3483 let traits = self.get_traits_containing_item(name.node, ValueNS);
3484 self.trait_map.insert(expr.id, traits);
3486 ExprKind::MethodCall(ref segment, ..) => {
3487 debug!("(recording candidate traits for expr) recording traits for {}",
3489 let traits = self.get_traits_containing_item(segment.identifier, ValueNS);
3490 self.trait_map.insert(expr.id, traits);
3498 fn get_traits_containing_item(&mut self, mut ident: Ident, ns: Namespace)
3499 -> Vec<TraitCandidate> {
3500 debug!("(getting traits containing item) looking for '{}'", ident.name);
3502 let mut found_traits = Vec::new();
3503 // Look for the current trait.
3504 if let Some((module, _)) = self.current_trait_ref {
3505 if self.resolve_ident_in_module(module, ident, ns, false, false, module.span).is_ok() {
3506 let def_id = module.def_id().unwrap();
3507 found_traits.push(TraitCandidate { def_id: def_id, import_id: None });
3511 ident.ctxt = ident.ctxt.modern();
3512 let mut search_module = self.current_module;
3514 self.get_traits_in_module_containing_item(ident, ns, search_module, &mut found_traits);
3516 unwrap_or!(self.hygienic_lexical_parent(search_module, &mut ident.ctxt), break);
3519 if let Some(prelude) = self.prelude {
3520 if !search_module.no_implicit_prelude {
3521 self.get_traits_in_module_containing_item(ident, ns, prelude, &mut found_traits);
3528 fn get_traits_in_module_containing_item(&mut self,
3532 found_traits: &mut Vec<TraitCandidate>) {
3533 let mut traits = module.traits.borrow_mut();
3534 if traits.is_none() {
3535 let mut collected_traits = Vec::new();
3536 module.for_each_child(|name, ns, binding| {
3537 if ns != TypeNS { return }
3538 if let Def::Trait(_) = binding.def() {
3539 collected_traits.push((name, binding));
3542 *traits = Some(collected_traits.into_boxed_slice());
3545 for &(trait_name, binding) in traits.as_ref().unwrap().iter() {
3546 let module = binding.module().unwrap();
3547 let mut ident = ident;
3548 if ident.ctxt.glob_adjust(module.expansion, binding.span.ctxt().modern()).is_none() {
3551 if self.resolve_ident_in_module_unadjusted(module, ident, ns, false, false, module.span)
3553 let import_id = match binding.kind {
3554 NameBindingKind::Import { directive, .. } => {
3555 self.maybe_unused_trait_imports.insert(directive.id);
3556 self.add_to_glob_map(directive.id, trait_name);
3561 let trait_def_id = module.def_id().unwrap();
3562 found_traits.push(TraitCandidate { def_id: trait_def_id, import_id: import_id });
3567 /// When name resolution fails, this method can be used to look up candidate
3568 /// entities with the expected name. It allows filtering them using the
3569 /// supplied predicate (which should be used to only accept the types of
3570 /// definitions expected e.g. traits). The lookup spans across all crates.
3572 /// NOTE: The method does not look into imports, but this is not a problem,
3573 /// since we report the definitions (thus, the de-aliased imports).
3574 fn lookup_import_candidates<FilterFn>(&mut self,
3576 namespace: Namespace,
3577 filter_fn: FilterFn)
3578 -> Vec<ImportSuggestion>
3579 where FilterFn: Fn(Def) -> bool
3581 let mut candidates = Vec::new();
3582 let mut worklist = Vec::new();
3583 let mut seen_modules = FxHashSet();
3584 worklist.push((self.graph_root, Vec::new(), false));
3586 while let Some((in_module,
3588 in_module_is_extern)) = worklist.pop() {
3589 self.populate_module_if_necessary(in_module);
3591 // We have to visit module children in deterministic order to avoid
3592 // instabilities in reported imports (#43552).
3593 in_module.for_each_child_stable(|ident, ns, name_binding| {
3594 // avoid imports entirely
3595 if name_binding.is_import() && !name_binding.is_extern_crate() { return; }
3596 // avoid non-importable candidates as well
3597 if !name_binding.is_importable() { return; }
3599 // collect results based on the filter function
3600 if ident.name == lookup_name && ns == namespace {
3601 if filter_fn(name_binding.def()) {
3603 let mut segms = path_segments.clone();
3604 segms.push(ast::PathSegment::from_ident(ident, name_binding.span));
3606 span: name_binding.span,
3609 // the entity is accessible in the following cases:
3610 // 1. if it's defined in the same crate, it's always
3611 // accessible (since private entities can be made public)
3612 // 2. if it's defined in another crate, it's accessible
3613 // only if both the module is public and the entity is
3614 // declared as public (due to pruning, we don't explore
3615 // outside crate private modules => no need to check this)
3616 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
3617 candidates.push(ImportSuggestion { path: path });
3622 // collect submodules to explore
3623 if let Some(module) = name_binding.module() {
3625 let mut path_segments = path_segments.clone();
3626 path_segments.push(ast::PathSegment::from_ident(ident, name_binding.span));
3628 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
3629 // add the module to the lookup
3630 let is_extern = in_module_is_extern || name_binding.is_extern_crate();
3631 if seen_modules.insert(module.def_id().unwrap()) {
3632 worklist.push((module, path_segments, is_extern));
3642 fn find_module(&mut self,
3644 -> Option<(Module<'a>, ImportSuggestion)>
3646 let mut result = None;
3647 let mut worklist = Vec::new();
3648 let mut seen_modules = FxHashSet();
3649 worklist.push((self.graph_root, Vec::new()));
3651 while let Some((in_module, path_segments)) = worklist.pop() {
3652 // abort if the module is already found
3653 if let Some(_) = result { break; }
3655 self.populate_module_if_necessary(in_module);
3657 in_module.for_each_child_stable(|ident, _, name_binding| {
3658 // abort if the module is already found or if name_binding is private external
3659 if result.is_some() || !name_binding.vis.is_visible_locally() {
3662 if let Some(module) = name_binding.module() {
3664 let mut path_segments = path_segments.clone();
3665 path_segments.push(ast::PathSegment::from_ident(ident, name_binding.span));
3666 if module.def() == Some(module_def) {
3668 span: name_binding.span,
3669 segments: path_segments,
3671 result = Some((module, ImportSuggestion { path: path }));
3673 // add the module to the lookup
3674 if seen_modules.insert(module.def_id().unwrap()) {
3675 worklist.push((module, path_segments));
3685 fn collect_enum_variants(&mut self, enum_def: Def) -> Option<Vec<Path>> {
3686 if let Def::Enum(..) = enum_def {} else {
3687 panic!("Non-enum def passed to collect_enum_variants: {:?}", enum_def)
3690 self.find_module(enum_def).map(|(enum_module, enum_import_suggestion)| {
3691 self.populate_module_if_necessary(enum_module);
3693 let mut variants = Vec::new();
3694 enum_module.for_each_child_stable(|ident, _, name_binding| {
3695 if let Def::Variant(..) = name_binding.def() {
3696 let mut segms = enum_import_suggestion.path.segments.clone();
3697 segms.push(ast::PathSegment::from_ident(ident, name_binding.span));
3698 variants.push(Path {
3699 span: name_binding.span,
3708 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
3709 debug!("(recording def) recording {:?} for {}", resolution, node_id);
3710 if let Some(prev_res) = self.def_map.insert(node_id, resolution) {
3711 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
3715 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
3717 ast::Visibility::Public => ty::Visibility::Public,
3718 ast::Visibility::Crate(..) => ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX)),
3719 ast::Visibility::Inherited => {
3720 ty::Visibility::Restricted(self.current_module.normal_ancestor_id)
3722 ast::Visibility::Restricted { ref path, id } => {
3723 let def = self.smart_resolve_path(id, None, path,
3724 PathSource::Visibility).base_def();
3725 if def == Def::Err {
3726 ty::Visibility::Public
3728 let vis = ty::Visibility::Restricted(def.def_id());
3729 if self.is_accessible(vis) {
3732 self.session.span_err(path.span, "visibilities can only be restricted \
3733 to ancestor modules");
3734 ty::Visibility::Public
3741 fn is_accessible(&self, vis: ty::Visibility) -> bool {
3742 vis.is_accessible_from(self.current_module.normal_ancestor_id, self)
3745 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
3746 vis.is_accessible_from(module.normal_ancestor_id, self)
3749 fn report_errors(&mut self, krate: &Crate) {
3750 self.report_shadowing_errors();
3751 self.report_with_use_injections(krate);
3752 self.report_proc_macro_import(krate);
3753 let mut reported_spans = FxHashSet();
3755 for &AmbiguityError { span, name, b1, b2, lexical, legacy } in &self.ambiguity_errors {
3756 if !reported_spans.insert(span) { continue }
3757 let participle = |binding: &NameBinding| {
3758 if binding.is_import() { "imported" } else { "defined" }
3760 let msg1 = format!("`{}` could refer to the name {} here", name, participle(b1));
3761 let msg2 = format!("`{}` could also refer to the name {} here", name, participle(b2));
3762 let note = if b1.expansion == Mark::root() || !lexical && b1.is_glob_import() {
3763 format!("consider adding an explicit import of `{}` to disambiguate", name)
3764 } else if let Def::Macro(..) = b1.def() {
3765 format!("macro-expanded {} do not shadow",
3766 if b1.is_import() { "macro imports" } else { "macros" })
3768 format!("macro-expanded {} do not shadow when used in a macro invocation path",
3769 if b1.is_import() { "imports" } else { "items" })
3772 let id = match b2.kind {
3773 NameBindingKind::Import { directive, .. } => directive.id,
3774 _ => unreachable!(),
3776 let mut span = MultiSpan::from_span(span);
3777 span.push_span_label(b1.span, msg1);
3778 span.push_span_label(b2.span, msg2);
3779 let msg = format!("`{}` is ambiguous", name);
3780 self.session.buffer_lint(lint::builtin::LEGACY_IMPORTS, id, span, &msg);
3783 self.session.struct_span_err(span, &format!("`{}` is ambiguous", name));
3784 err.span_note(b1.span, &msg1);
3786 Def::Macro(..) if b2.span == DUMMY_SP =>
3787 err.note(&format!("`{}` is also a builtin macro", name)),
3788 _ => err.span_note(b2.span, &msg2),
3790 err.note(¬e).emit();
3794 for &PrivacyError(span, name, binding) in &self.privacy_errors {
3795 if !reported_spans.insert(span) { continue }
3796 span_err!(self.session, span, E0603, "{} `{}` is private", binding.descr(), name);
3800 fn report_with_use_injections(&mut self, krate: &Crate) {
3801 for UseError { mut err, candidates, node_id, better } in self.use_injections.drain(..) {
3802 let (span, found_use) = UsePlacementFinder::check(krate, node_id);
3803 if !candidates.is_empty() {
3804 show_candidates(&mut err, span, &candidates, better, found_use);
3810 fn report_shadowing_errors(&mut self) {
3811 for (ident, scope) in replace(&mut self.lexical_macro_resolutions, Vec::new()) {
3812 self.resolve_legacy_scope(scope, ident, true);
3815 let mut reported_errors = FxHashSet();
3816 for binding in replace(&mut self.disallowed_shadowing, Vec::new()) {
3817 if self.resolve_legacy_scope(&binding.parent, binding.ident, false).is_some() &&
3818 reported_errors.insert((binding.ident, binding.span)) {
3819 let msg = format!("`{}` is already in scope", binding.ident);
3820 self.session.struct_span_err(binding.span, &msg)
3821 .note("macro-expanded `macro_rules!`s may not shadow \
3822 existing macros (see RFC 1560)")
3828 fn report_conflict<'b>(&mut self,
3832 new_binding: &NameBinding<'b>,
3833 old_binding: &NameBinding<'b>) {
3834 // Error on the second of two conflicting names
3835 if old_binding.span.lo() > new_binding.span.lo() {
3836 return self.report_conflict(parent, ident, ns, old_binding, new_binding);
3839 let container = match parent.kind {
3840 ModuleKind::Def(Def::Mod(_), _) => "module",
3841 ModuleKind::Def(Def::Trait(_), _) => "trait",
3842 ModuleKind::Block(..) => "block",
3846 let old_noun = match old_binding.is_import() {
3848 false => "definition",
3851 let new_participle = match new_binding.is_import() {
3856 let (name, span) = (ident.name, self.session.codemap().def_span(new_binding.span));
3858 if let Some(s) = self.name_already_seen.get(&name) {
3864 let old_kind = match (ns, old_binding.module()) {
3865 (ValueNS, _) => "value",
3866 (MacroNS, _) => "macro",
3867 (TypeNS, _) if old_binding.is_extern_crate() => "extern crate",
3868 (TypeNS, Some(module)) if module.is_normal() => "module",
3869 (TypeNS, Some(module)) if module.is_trait() => "trait",
3870 (TypeNS, _) => "type",
3873 let namespace = match ns {
3879 let msg = format!("the name `{}` is defined multiple times", name);
3881 let mut err = match (old_binding.is_extern_crate(), new_binding.is_extern_crate()) {
3882 (true, true) => struct_span_err!(self.session, span, E0259, "{}", msg),
3883 (true, _) | (_, true) => match new_binding.is_import() && old_binding.is_import() {
3884 true => struct_span_err!(self.session, span, E0254, "{}", msg),
3885 false => struct_span_err!(self.session, span, E0260, "{}", msg),
3887 _ => match (old_binding.is_import(), new_binding.is_import()) {
3888 (false, false) => struct_span_err!(self.session, span, E0428, "{}", msg),
3889 (true, true) => struct_span_err!(self.session, span, E0252, "{}", msg),
3890 _ => struct_span_err!(self.session, span, E0255, "{}", msg),
3894 err.note(&format!("`{}` must be defined only once in the {} namespace of this {}",
3899 err.span_label(span, format!("`{}` re{} here", name, new_participle));
3900 if old_binding.span != syntax_pos::DUMMY_SP {
3901 err.span_label(self.session.codemap().def_span(old_binding.span),
3902 format!("previous {} of the {} `{}` here", old_noun, old_kind, name));
3905 // See https://github.com/rust-lang/rust/issues/32354
3906 if old_binding.is_import() || new_binding.is_import() {
3907 let binding = if new_binding.is_import() {
3913 let cm = self.session.codemap();
3914 let rename_msg = "You can use `as` to change the binding name of the import";
3916 if let (Ok(snippet), false) = (cm.span_to_snippet(binding.span),
3917 binding.is_renamed_extern_crate()) {
3918 err.span_suggestion(binding.span,
3920 format!("{} as Other{}", snippet, name));
3922 err.span_label(binding.span, rename_msg);
3927 self.name_already_seen.insert(name, span);
3930 fn warn_legacy_self_import(&self, directive: &'a ImportDirective<'a>) {
3931 let (id, span) = (directive.id, directive.span);
3932 let msg = "`self` no longer imports values";
3933 self.session.buffer_lint(lint::builtin::LEGACY_IMPORTS, id, span, msg);
3936 fn check_proc_macro_attrs(&mut self, attrs: &[ast::Attribute]) {
3937 if self.proc_macro_enabled { return; }
3940 if attr.path.segments.len() > 1 {
3943 let ident = attr.path.segments[0].identifier;
3944 let result = self.resolve_lexical_macro_path_segment(ident,
3948 if let Ok(binding) = result {
3949 if let SyntaxExtension::AttrProcMacro(..) = *binding.binding().get_macro(self) {
3950 attr::mark_known(attr);
3952 let msg = "attribute procedural macros are experimental";
3953 let feature = "proc_macro";
3955 feature_err(&self.session.parse_sess, feature,
3956 attr.span, GateIssue::Language, msg)
3957 .span_label(binding.span(), "procedural macro imported here")
3965 fn is_struct_like(def: Def) -> bool {
3967 Def::VariantCtor(_, CtorKind::Fictive) => true,
3968 _ => PathSource::Struct.is_expected(def),
3972 fn is_self_type(path: &[SpannedIdent], namespace: Namespace) -> bool {
3973 namespace == TypeNS && path.len() == 1 && path[0].node.name == keywords::SelfType.name()
3976 fn is_self_value(path: &[SpannedIdent], namespace: Namespace) -> bool {
3977 namespace == ValueNS && path.len() == 1 && path[0].node.name == keywords::SelfValue.name()
3980 fn names_to_string(idents: &[SpannedIdent]) -> String {
3981 let mut result = String::new();
3982 for (i, ident) in idents.iter()
3983 .filter(|i| i.node.name != keywords::CrateRoot.name())
3986 result.push_str("::");
3988 result.push_str(&ident.node.name.as_str());
3993 fn path_names_to_string(path: &Path) -> String {
3994 names_to_string(&path.segments.iter()
3995 .map(|seg| respan(seg.span, seg.identifier))
3996 .collect::<Vec<_>>())
3999 /// Get the path for an enum and the variant from an `ImportSuggestion` for an enum variant.
4000 fn import_candidate_to_paths(suggestion: &ImportSuggestion) -> (Span, String, String) {
4001 let variant_path = &suggestion.path;
4002 let variant_path_string = path_names_to_string(variant_path);
4004 let path_len = suggestion.path.segments.len();
4005 let enum_path = ast::Path {
4006 span: suggestion.path.span,
4007 segments: suggestion.path.segments[0..path_len - 1].to_vec(),
4009 let enum_path_string = path_names_to_string(&enum_path);
4011 (suggestion.path.span, variant_path_string, enum_path_string)
4015 /// When an entity with a given name is not available in scope, we search for
4016 /// entities with that name in all crates. This method allows outputting the
4017 /// results of this search in a programmer-friendly way
4018 fn show_candidates(err: &mut DiagnosticBuilder,
4019 // This is `None` if all placement locations are inside expansions
4021 candidates: &[ImportSuggestion],
4025 // we want consistent results across executions, but candidates are produced
4026 // by iterating through a hash map, so make sure they are ordered:
4027 let mut path_strings: Vec<_> =
4028 candidates.into_iter().map(|c| path_names_to_string(&c.path)).collect();
4029 path_strings.sort();
4031 let better = if better { "better " } else { "" };
4032 let msg_diff = match path_strings.len() {
4033 1 => " is found in another module, you can import it",
4034 _ => "s are found in other modules, you can import them",
4036 let msg = format!("possible {}candidate{} into scope", better, msg_diff);
4038 if let Some(span) = span {
4039 for candidate in &mut path_strings {
4040 // produce an additional newline to separate the new use statement
4041 // from the directly following item.
4042 let additional_newline = if found_use {
4047 *candidate = format!("use {};\n{}", candidate, additional_newline);
4050 err.span_suggestions(span, &msg, path_strings);
4054 for candidate in path_strings {
4056 msg.push_str(&candidate);
4061 /// A somewhat inefficient routine to obtain the name of a module.
4062 fn module_to_string(module: Module) -> String {
4063 let mut names = Vec::new();
4065 fn collect_mod(names: &mut Vec<Ident>, module: Module) {
4066 if let ModuleKind::Def(_, name) = module.kind {
4067 if let Some(parent) = module.parent {
4068 names.push(Ident::with_empty_ctxt(name));
4069 collect_mod(names, parent);
4072 // danger, shouldn't be ident?
4073 names.push(Ident::from_str("<opaque>"));
4074 collect_mod(names, module.parent.unwrap());
4077 collect_mod(&mut names, module);
4079 if names.is_empty() {
4080 return "???".to_string();
4082 names_to_string(&names.into_iter()
4084 .map(|n| dummy_spanned(n))
4085 .collect::<Vec<_>>())
4088 fn err_path_resolution() -> PathResolution {
4089 PathResolution::new(Def::Err)
4092 #[derive(PartialEq,Copy, Clone)]
4093 pub enum MakeGlobMap {
4098 #[cfg(not(stage0))] // remove after the next snapshot
4099 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }