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/")]
15 #![feature(crate_visibility_modifier)]
16 #![cfg_attr(not(stage0), feature(nll))]
17 #![cfg_attr(not(stage0), feature(infer_outlives_requirements))]
18 #![feature(rustc_diagnostic_macros)]
19 #![feature(slice_sort_by_cached_key)]
25 extern crate syntax_pos;
26 extern crate rustc_errors as errors;
30 extern crate rustc_data_structures;
31 extern crate rustc_metadata;
33 pub use rustc::hir::def::{Namespace, PerNS};
35 use self::TypeParameters::*;
38 use rustc::hir::map::{Definitions, DefCollector};
39 use rustc::hir::{self, PrimTy, Bool, Char, Float, Int, Uint, Str};
40 use rustc::middle::cstore::CrateStore;
41 use rustc::session::Session;
43 use rustc::hir::def::*;
44 use rustc::hir::def::Namespace::*;
45 use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, DefId};
47 use rustc::hir::{Freevar, FreevarMap, TraitCandidate, TraitMap, GlobMap};
48 use rustc::util::nodemap::{NodeMap, NodeSet, FxHashMap, FxHashSet, DefIdMap};
50 use rustc_metadata::creader::CrateLoader;
51 use rustc_metadata::cstore::CStore;
53 use syntax::source_map::SourceMap;
54 use syntax::ext::hygiene::{Mark, Transparency, SyntaxContext};
55 use syntax::ast::{self, Name, NodeId, Ident, FloatTy, IntTy, UintTy};
56 use syntax::ext::base::SyntaxExtension;
57 use syntax::ext::base::Determinacy::{self, Determined, Undetermined};
58 use syntax::ext::base::MacroKind;
59 use syntax::symbol::{Symbol, keywords};
60 use syntax::util::lev_distance::find_best_match_for_name;
62 use syntax::visit::{self, FnKind, Visitor};
64 use syntax::ast::{CRATE_NODE_ID, Arm, IsAsync, BindingMode, Block, Crate, Expr, ExprKind};
65 use syntax::ast::{FnDecl, ForeignItem, ForeignItemKind, GenericParamKind, Generics};
66 use syntax::ast::{Item, ItemKind, ImplItem, ImplItemKind};
67 use syntax::ast::{Label, Local, Mutability, Pat, PatKind, Path};
68 use syntax::ast::{QSelf, TraitItemKind, TraitRef, Ty, TyKind};
69 use syntax::feature_gate::{feature_err, GateIssue};
72 use syntax_pos::{Span, DUMMY_SP, MultiSpan};
73 use errors::{DiagnosticBuilder, DiagnosticId};
75 use std::cell::{Cell, RefCell};
77 use std::collections::BTreeSet;
80 use std::mem::replace;
81 use rustc_data_structures::sync::Lrc;
83 use resolve_imports::{ImportDirective, ImportDirectiveSubclass, NameResolution, ImportResolver};
84 use macros::{InvocationData, LegacyBinding};
86 // NB: This module needs to be declared first so diagnostics are
87 // registered before they are used.
92 mod build_reduced_graph;
95 fn is_known_tool(name: Name) -> bool {
96 ["clippy", "rustfmt"].contains(&&*name.as_str())
99 /// A free importable items suggested in case of resolution failure.
100 struct ImportSuggestion {
104 /// A field or associated item from self type suggested in case of resolution failure.
105 enum AssocSuggestion {
112 struct BindingError {
114 origin: BTreeSet<Span>,
115 target: BTreeSet<Span>,
118 impl PartialOrd for BindingError {
119 fn partial_cmp(&self, other: &BindingError) -> Option<cmp::Ordering> {
120 Some(self.cmp(other))
124 impl PartialEq for BindingError {
125 fn eq(&self, other: &BindingError) -> bool {
126 self.name == other.name
130 impl Ord for BindingError {
131 fn cmp(&self, other: &BindingError) -> cmp::Ordering {
132 self.name.cmp(&other.name)
136 enum ResolutionError<'a> {
137 /// error E0401: can't use type parameters from outer function
138 TypeParametersFromOuterFunction(Def),
139 /// error E0403: the name is already used for a type parameter in this type parameter list
140 NameAlreadyUsedInTypeParameterList(Name, &'a Span),
141 /// error E0407: method is not a member of trait
142 MethodNotMemberOfTrait(Name, &'a str),
143 /// error E0437: type is not a member of trait
144 TypeNotMemberOfTrait(Name, &'a str),
145 /// error E0438: const is not a member of trait
146 ConstNotMemberOfTrait(Name, &'a str),
147 /// error E0408: variable `{}` is not bound in all patterns
148 VariableNotBoundInPattern(&'a BindingError),
149 /// error E0409: variable `{}` is bound in inconsistent ways within the same match arm
150 VariableBoundWithDifferentMode(Name, Span),
151 /// error E0415: identifier is bound more than once in this parameter list
152 IdentifierBoundMoreThanOnceInParameterList(&'a str),
153 /// error E0416: identifier is bound more than once in the same pattern
154 IdentifierBoundMoreThanOnceInSamePattern(&'a str),
155 /// error E0426: use of undeclared label
156 UndeclaredLabel(&'a str, Option<Name>),
157 /// error E0429: `self` imports are only allowed within a { } list
158 SelfImportsOnlyAllowedWithin,
159 /// error E0430: `self` import can only appear once in the list
160 SelfImportCanOnlyAppearOnceInTheList,
161 /// error E0431: `self` import can only appear in an import list with a non-empty prefix
162 SelfImportOnlyInImportListWithNonEmptyPrefix,
163 /// error E0432: unresolved import
164 UnresolvedImport(Option<(Span, &'a str, &'a str)>),
165 /// error E0433: failed to resolve
166 FailedToResolve(&'a str),
167 /// error E0434: can't capture dynamic environment in a fn item
168 CannotCaptureDynamicEnvironmentInFnItem,
169 /// error E0435: attempt to use a non-constant value in a constant
170 AttemptToUseNonConstantValueInConstant,
171 /// error E0530: X bindings cannot shadow Ys
172 BindingShadowsSomethingUnacceptable(&'a str, Name, &'a NameBinding<'a>),
173 /// error E0128: type parameters with a default cannot use forward declared identifiers
174 ForwardDeclaredTyParam,
177 /// Combines an error with provided span and emits it
179 /// This takes the error provided, combines it with the span and any additional spans inside the
180 /// error and emits it.
181 fn resolve_error<'sess, 'a>(resolver: &'sess Resolver,
183 resolution_error: ResolutionError<'a>) {
184 resolve_struct_error(resolver, span, resolution_error).emit();
187 fn resolve_struct_error<'sess, 'a>(resolver: &'sess Resolver,
189 resolution_error: ResolutionError<'a>)
190 -> DiagnosticBuilder<'sess> {
191 match resolution_error {
192 ResolutionError::TypeParametersFromOuterFunction(outer_def) => {
193 let mut err = struct_span_err!(resolver.session,
196 "can't use type parameters from outer function");
197 err.span_label(span, "use of type variable from outer function");
199 let cm = resolver.session.source_map();
201 Def::SelfTy(_, maybe_impl_defid) => {
202 if let Some(impl_span) = maybe_impl_defid.map_or(None,
203 |def_id| resolver.definitions.opt_span(def_id)) {
204 err.span_label(reduce_impl_span_to_impl_keyword(cm, impl_span),
205 "`Self` type implicitly declared here, on the `impl`");
208 Def::TyParam(typaram_defid) => {
209 if let Some(typaram_span) = resolver.definitions.opt_span(typaram_defid) {
210 err.span_label(typaram_span, "type variable from outer function");
214 bug!("TypeParametersFromOuterFunction should only be used with Def::SelfTy or \
219 // Try to retrieve the span of the function signature and generate a new message with
220 // a local type parameter
221 let sugg_msg = "try using a local type parameter instead";
222 if let Some((sugg_span, new_snippet)) = cm.generate_local_type_param_snippet(span) {
223 // Suggest the modification to the user
224 err.span_suggestion(sugg_span,
227 } else if let Some(sp) = cm.generate_fn_name_span(span) {
228 err.span_label(sp, "try adding a local type parameter in this method instead");
230 err.help("try using a local type parameter instead");
235 ResolutionError::NameAlreadyUsedInTypeParameterList(name, first_use_span) => {
236 let mut err = struct_span_err!(resolver.session,
239 "the name `{}` is already used for a type parameter \
240 in this type parameter list",
242 err.span_label(span, "already used");
243 err.span_label(first_use_span.clone(), format!("first use of `{}`", name));
246 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
247 let mut err = struct_span_err!(resolver.session,
250 "method `{}` is not a member of trait `{}`",
253 err.span_label(span, format!("not a member of trait `{}`", trait_));
256 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
257 let mut err = struct_span_err!(resolver.session,
260 "type `{}` is not a member of trait `{}`",
263 err.span_label(span, format!("not a member of trait `{}`", trait_));
266 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
267 let mut err = struct_span_err!(resolver.session,
270 "const `{}` is not a member of trait `{}`",
273 err.span_label(span, format!("not a member of trait `{}`", trait_));
276 ResolutionError::VariableNotBoundInPattern(binding_error) => {
277 let target_sp = binding_error.target.iter().cloned().collect::<Vec<_>>();
278 let msp = MultiSpan::from_spans(target_sp.clone());
279 let msg = format!("variable `{}` is not bound in all patterns", binding_error.name);
280 let mut err = resolver.session.struct_span_err_with_code(
283 DiagnosticId::Error("E0408".into()),
285 for sp in target_sp {
286 err.span_label(sp, format!("pattern doesn't bind `{}`", binding_error.name));
288 let origin_sp = binding_error.origin.iter().cloned();
289 for sp in origin_sp {
290 err.span_label(sp, "variable not in all patterns");
294 ResolutionError::VariableBoundWithDifferentMode(variable_name,
295 first_binding_span) => {
296 let mut err = struct_span_err!(resolver.session,
299 "variable `{}` is bound in inconsistent \
300 ways within the same match arm",
302 err.span_label(span, "bound in different ways");
303 err.span_label(first_binding_span, "first binding");
306 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
307 let mut err = struct_span_err!(resolver.session,
310 "identifier `{}` is bound more than once in this parameter list",
312 err.span_label(span, "used as parameter more than once");
315 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
316 let mut err = struct_span_err!(resolver.session,
319 "identifier `{}` is bound more than once in the same pattern",
321 err.span_label(span, "used in a pattern more than once");
324 ResolutionError::UndeclaredLabel(name, lev_candidate) => {
325 let mut err = struct_span_err!(resolver.session,
328 "use of undeclared label `{}`",
330 if let Some(lev_candidate) = lev_candidate {
331 err.span_label(span, format!("did you mean `{}`?", lev_candidate));
333 err.span_label(span, format!("undeclared label `{}`", name));
337 ResolutionError::SelfImportsOnlyAllowedWithin => {
338 struct_span_err!(resolver.session,
342 "`self` imports are only allowed within a { } list")
344 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
345 let mut err = struct_span_err!(resolver.session, span, E0430,
346 "`self` import can only appear once in an import list");
347 err.span_label(span, "can only appear once in an import list");
350 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
351 let mut err = struct_span_err!(resolver.session, span, E0431,
352 "`self` import can only appear in an import list with \
353 a non-empty prefix");
354 err.span_label(span, "can only appear in an import list with a non-empty prefix");
357 ResolutionError::UnresolvedImport(name) => {
358 let (span, msg) = match name {
359 Some((sp, n, _)) => (sp, format!("unresolved import `{}`", n)),
360 None => (span, "unresolved import".to_owned()),
362 let mut err = struct_span_err!(resolver.session, span, E0432, "{}", msg);
363 if let Some((_, _, p)) = name {
364 err.span_label(span, p);
368 ResolutionError::FailedToResolve(msg) => {
369 let mut err = struct_span_err!(resolver.session, span, E0433,
370 "failed to resolve. {}", msg);
371 err.span_label(span, msg);
374 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
375 let mut err = struct_span_err!(resolver.session,
379 "can't capture dynamic environment in a fn item");
380 err.help("use the `|| { ... }` closure form instead");
383 ResolutionError::AttemptToUseNonConstantValueInConstant => {
384 let mut err = struct_span_err!(resolver.session, span, E0435,
385 "attempt to use a non-constant value in a constant");
386 err.span_label(span, "non-constant value");
389 ResolutionError::BindingShadowsSomethingUnacceptable(what_binding, name, binding) => {
390 let shadows_what = PathResolution::new(binding.def()).kind_name();
391 let mut err = struct_span_err!(resolver.session,
394 "{}s cannot shadow {}s", what_binding, shadows_what);
395 err.span_label(span, format!("cannot be named the same as a {}", shadows_what));
396 let participle = if binding.is_import() { "imported" } else { "defined" };
397 let msg = format!("a {} `{}` is {} here", shadows_what, name, participle);
398 err.span_label(binding.span, msg);
401 ResolutionError::ForwardDeclaredTyParam => {
402 let mut err = struct_span_err!(resolver.session, span, E0128,
403 "type parameters with a default cannot use \
404 forward declared identifiers");
406 span, "defaulted type parameters cannot be forward declared".to_string());
412 /// Adjust the impl span so that just the `impl` keyword is taken by removing
413 /// everything after `<` (`"impl<T> Iterator for A<T> {}" -> "impl"`) and
414 /// everything after the first whitespace (`"impl Iterator for A" -> "impl"`)
416 /// Attention: The method used is very fragile since it essentially duplicates the work of the
417 /// parser. If you need to use this function or something similar, please consider updating the
418 /// source_map functions and this function to something more robust.
419 fn reduce_impl_span_to_impl_keyword(cm: &SourceMap, impl_span: Span) -> Span {
420 let impl_span = cm.span_until_char(impl_span, '<');
421 let impl_span = cm.span_until_whitespace(impl_span);
425 #[derive(Copy, Clone, Debug)]
428 binding_mode: BindingMode,
431 /// Map from the name in a pattern to its binding mode.
432 type BindingMap = FxHashMap<Ident, BindingInfo>;
434 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
445 fn descr(self) -> &'static str {
447 PatternSource::Match => "match binding",
448 PatternSource::IfLet => "if let binding",
449 PatternSource::WhileLet => "while let binding",
450 PatternSource::Let => "let binding",
451 PatternSource::For => "for binding",
452 PatternSource::FnParam => "function parameter",
457 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
458 enum AliasPossibility {
463 #[derive(Copy, Clone, Debug)]
464 enum PathSource<'a> {
465 // Type paths `Path`.
467 // Trait paths in bounds or impls.
468 Trait(AliasPossibility),
469 // Expression paths `path`, with optional parent context.
470 Expr(Option<&'a Expr>),
471 // Paths in path patterns `Path`.
473 // Paths in struct expressions and patterns `Path { .. }`.
475 // Paths in tuple struct patterns `Path(..)`.
477 // `m::A::B` in `<T as m::A>::B::C`.
478 TraitItem(Namespace),
479 // Path in `pub(path)`
481 // Path in `use a::b::{...};`
485 impl<'a> PathSource<'a> {
486 fn namespace(self) -> Namespace {
488 PathSource::Type | PathSource::Trait(_) | PathSource::Struct |
489 PathSource::Visibility | PathSource::ImportPrefix => TypeNS,
490 PathSource::Expr(..) | PathSource::Pat | PathSource::TupleStruct => ValueNS,
491 PathSource::TraitItem(ns) => ns,
495 fn global_by_default(self) -> bool {
497 PathSource::Visibility | PathSource::ImportPrefix => true,
498 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
499 PathSource::Struct | PathSource::TupleStruct |
500 PathSource::Trait(_) | PathSource::TraitItem(..) => false,
504 fn defer_to_typeck(self) -> bool {
506 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
507 PathSource::Struct | PathSource::TupleStruct => true,
508 PathSource::Trait(_) | PathSource::TraitItem(..) |
509 PathSource::Visibility | PathSource::ImportPrefix => false,
513 fn descr_expected(self) -> &'static str {
515 PathSource::Type => "type",
516 PathSource::Trait(_) => "trait",
517 PathSource::Pat => "unit struct/variant or constant",
518 PathSource::Struct => "struct, variant or union type",
519 PathSource::TupleStruct => "tuple struct/variant",
520 PathSource::Visibility => "module",
521 PathSource::ImportPrefix => "module or enum",
522 PathSource::TraitItem(ns) => match ns {
523 TypeNS => "associated type",
524 ValueNS => "method or associated constant",
525 MacroNS => bug!("associated macro"),
527 PathSource::Expr(parent) => match parent.map(|p| &p.node) {
528 // "function" here means "anything callable" rather than `Def::Fn`,
529 // this is not precise but usually more helpful than just "value".
530 Some(&ExprKind::Call(..)) => "function",
536 fn is_expected(self, def: Def) -> bool {
538 PathSource::Type => match def {
539 Def::Struct(..) | Def::Union(..) | Def::Enum(..) |
540 Def::Trait(..) | Def::TyAlias(..) | Def::AssociatedTy(..) |
541 Def::PrimTy(..) | Def::TyParam(..) | Def::SelfTy(..) |
542 Def::Existential(..) |
543 Def::ForeignTy(..) => true,
546 PathSource::Trait(AliasPossibility::No) => match def {
547 Def::Trait(..) => true,
550 PathSource::Trait(AliasPossibility::Maybe) => match def {
551 Def::Trait(..) => true,
552 Def::TraitAlias(..) => true,
555 PathSource::Expr(..) => match def {
556 Def::StructCtor(_, CtorKind::Const) | Def::StructCtor(_, CtorKind::Fn) |
557 Def::VariantCtor(_, CtorKind::Const) | Def::VariantCtor(_, CtorKind::Fn) |
558 Def::Const(..) | Def::Static(..) | Def::Local(..) | Def::Upvar(..) |
559 Def::Fn(..) | Def::Method(..) | Def::AssociatedConst(..) => true,
562 PathSource::Pat => match def {
563 Def::StructCtor(_, CtorKind::Const) |
564 Def::VariantCtor(_, CtorKind::Const) |
565 Def::Const(..) | Def::AssociatedConst(..) => true,
568 PathSource::TupleStruct => match def {
569 Def::StructCtor(_, CtorKind::Fn) | Def::VariantCtor(_, CtorKind::Fn) => true,
572 PathSource::Struct => match def {
573 Def::Struct(..) | Def::Union(..) | Def::Variant(..) |
574 Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) => true,
577 PathSource::TraitItem(ns) => match def {
578 Def::AssociatedConst(..) | Def::Method(..) if ns == ValueNS => true,
579 Def::AssociatedTy(..) if ns == TypeNS => true,
582 PathSource::ImportPrefix => match def {
583 Def::Mod(..) | Def::Enum(..) => true,
586 PathSource::Visibility => match def {
587 Def::Mod(..) => true,
593 fn error_code(self, has_unexpected_resolution: bool) -> &'static str {
594 __diagnostic_used!(E0404);
595 __diagnostic_used!(E0405);
596 __diagnostic_used!(E0412);
597 __diagnostic_used!(E0422);
598 __diagnostic_used!(E0423);
599 __diagnostic_used!(E0425);
600 __diagnostic_used!(E0531);
601 __diagnostic_used!(E0532);
602 __diagnostic_used!(E0573);
603 __diagnostic_used!(E0574);
604 __diagnostic_used!(E0575);
605 __diagnostic_used!(E0576);
606 __diagnostic_used!(E0577);
607 __diagnostic_used!(E0578);
608 match (self, has_unexpected_resolution) {
609 (PathSource::Trait(_), true) => "E0404",
610 (PathSource::Trait(_), false) => "E0405",
611 (PathSource::Type, true) => "E0573",
612 (PathSource::Type, false) => "E0412",
613 (PathSource::Struct, true) => "E0574",
614 (PathSource::Struct, false) => "E0422",
615 (PathSource::Expr(..), true) => "E0423",
616 (PathSource::Expr(..), false) => "E0425",
617 (PathSource::Pat, true) | (PathSource::TupleStruct, true) => "E0532",
618 (PathSource::Pat, false) | (PathSource::TupleStruct, false) => "E0531",
619 (PathSource::TraitItem(..), true) => "E0575",
620 (PathSource::TraitItem(..), false) => "E0576",
621 (PathSource::Visibility, true) | (PathSource::ImportPrefix, true) => "E0577",
622 (PathSource::Visibility, false) | (PathSource::ImportPrefix, false) => "E0578",
627 struct UsePlacementFinder {
628 target_module: NodeId,
633 impl UsePlacementFinder {
634 fn check(krate: &Crate, target_module: NodeId) -> (Option<Span>, bool) {
635 let mut finder = UsePlacementFinder {
640 visit::walk_crate(&mut finder, krate);
641 (finder.span, finder.found_use)
645 impl<'tcx> Visitor<'tcx> for UsePlacementFinder {
648 module: &'tcx ast::Mod,
650 _: &[ast::Attribute],
653 if self.span.is_some() {
656 if node_id != self.target_module {
657 visit::walk_mod(self, module);
660 // find a use statement
661 for item in &module.items {
663 ItemKind::Use(..) => {
664 // don't suggest placing a use before the prelude
665 // import or other generated ones
666 if item.span.ctxt().outer().expn_info().is_none() {
667 self.span = Some(item.span.shrink_to_lo());
668 self.found_use = true;
672 // don't place use before extern crate
673 ItemKind::ExternCrate(_) => {}
674 // but place them before the first other item
675 _ => if self.span.map_or(true, |span| item.span < span ) {
676 if item.span.ctxt().outer().expn_info().is_none() {
677 // don't insert between attributes and an item
678 if item.attrs.is_empty() {
679 self.span = Some(item.span.shrink_to_lo());
681 // find the first attribute on the item
682 for attr in &item.attrs {
683 if self.span.map_or(true, |span| attr.span < span) {
684 self.span = Some(attr.span.shrink_to_lo());
695 /// This thing walks the whole crate in DFS manner, visiting each item, resolving names as it goes.
696 impl<'a, 'tcx, 'cl> Visitor<'tcx> for Resolver<'a, 'cl> {
697 fn visit_item(&mut self, item: &'tcx Item) {
698 self.resolve_item(item);
700 fn visit_arm(&mut self, arm: &'tcx Arm) {
701 self.resolve_arm(arm);
703 fn visit_block(&mut self, block: &'tcx Block) {
704 self.resolve_block(block);
706 fn visit_anon_const(&mut self, constant: &'tcx ast::AnonConst) {
707 self.with_constant_rib(|this| {
708 visit::walk_anon_const(this, constant);
711 fn visit_expr(&mut self, expr: &'tcx Expr) {
712 self.resolve_expr(expr, None);
714 fn visit_local(&mut self, local: &'tcx Local) {
715 self.resolve_local(local);
717 fn visit_ty(&mut self, ty: &'tcx Ty) {
719 TyKind::Path(ref qself, ref path) => {
720 self.smart_resolve_path(ty.id, qself.as_ref(), path, PathSource::Type);
722 TyKind::ImplicitSelf => {
723 let self_ty = keywords::SelfType.ident();
724 let def = self.resolve_ident_in_lexical_scope(self_ty, TypeNS, Some(ty.id), ty.span)
725 .map_or(Def::Err, |d| d.def());
726 self.record_def(ty.id, PathResolution::new(def));
730 visit::walk_ty(self, ty);
732 fn visit_poly_trait_ref(&mut self,
733 tref: &'tcx ast::PolyTraitRef,
734 m: &'tcx ast::TraitBoundModifier) {
735 self.smart_resolve_path(tref.trait_ref.ref_id, None,
736 &tref.trait_ref.path, PathSource::Trait(AliasPossibility::Maybe));
737 visit::walk_poly_trait_ref(self, tref, m);
739 fn visit_foreign_item(&mut self, foreign_item: &'tcx ForeignItem) {
740 let type_parameters = match foreign_item.node {
741 ForeignItemKind::Fn(_, ref generics) => {
742 HasTypeParameters(generics, ItemRibKind)
744 ForeignItemKind::Static(..) => NoTypeParameters,
745 ForeignItemKind::Ty => NoTypeParameters,
746 ForeignItemKind::Macro(..) => NoTypeParameters,
748 self.with_type_parameter_rib(type_parameters, |this| {
749 visit::walk_foreign_item(this, foreign_item);
752 fn visit_fn(&mut self,
753 function_kind: FnKind<'tcx>,
754 declaration: &'tcx FnDecl,
758 let (rib_kind, asyncness) = match function_kind {
759 FnKind::ItemFn(_, ref header, ..) =>
760 (ItemRibKind, header.asyncness),
761 FnKind::Method(_, ref sig, _, _) =>
762 (TraitOrImplItemRibKind, sig.header.asyncness),
763 FnKind::Closure(_) =>
764 // Async closures aren't resolved through `visit_fn`-- they're
765 // processed separately
766 (ClosureRibKind(node_id), IsAsync::NotAsync),
769 // Create a value rib for the function.
770 self.ribs[ValueNS].push(Rib::new(rib_kind));
772 // Create a label rib for the function.
773 self.label_ribs.push(Rib::new(rib_kind));
775 // Add each argument to the rib.
776 let mut bindings_list = FxHashMap();
777 for argument in &declaration.inputs {
778 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
780 self.visit_ty(&argument.ty);
782 debug!("(resolving function) recorded argument");
784 visit::walk_fn_ret_ty(self, &declaration.output);
786 // Resolve the function body, potentially inside the body of an async closure
787 if let IsAsync::Async { closure_id, .. } = asyncness {
788 let rib_kind = ClosureRibKind(closure_id);
789 self.ribs[ValueNS].push(Rib::new(rib_kind));
790 self.label_ribs.push(Rib::new(rib_kind));
793 match function_kind {
794 FnKind::ItemFn(.., body) |
795 FnKind::Method(.., body) => {
796 self.visit_block(body);
798 FnKind::Closure(body) => {
799 self.visit_expr(body);
803 // Leave the body of the async closure
804 if asyncness.is_async() {
805 self.label_ribs.pop();
806 self.ribs[ValueNS].pop();
809 debug!("(resolving function) leaving function");
811 self.label_ribs.pop();
812 self.ribs[ValueNS].pop();
814 fn visit_generics(&mut self, generics: &'tcx Generics) {
815 // For type parameter defaults, we have to ban access
816 // to following type parameters, as the Substs can only
817 // provide previous type parameters as they're built. We
818 // put all the parameters on the ban list and then remove
819 // them one by one as they are processed and become available.
820 let mut default_ban_rib = Rib::new(ForwardTyParamBanRibKind);
821 let mut found_default = false;
822 default_ban_rib.bindings.extend(generics.params.iter()
823 .filter_map(|param| match param.kind {
824 GenericParamKind::Lifetime { .. } => None,
825 GenericParamKind::Type { ref default, .. } => {
826 found_default |= default.is_some();
828 Some((Ident::with_empty_ctxt(param.ident.name), Def::Err))
835 for param in &generics.params {
837 GenericParamKind::Lifetime { .. } => self.visit_generic_param(param),
838 GenericParamKind::Type { ref default, .. } => {
839 for bound in ¶m.bounds {
840 self.visit_param_bound(bound);
843 if let Some(ref ty) = default {
844 self.ribs[TypeNS].push(default_ban_rib);
846 default_ban_rib = self.ribs[TypeNS].pop().unwrap();
849 // Allow all following defaults to refer to this type parameter.
850 default_ban_rib.bindings.remove(&Ident::with_empty_ctxt(param.ident.name));
854 for p in &generics.where_clause.predicates {
855 self.visit_where_predicate(p);
860 #[derive(Copy, Clone)]
861 enum TypeParameters<'a, 'b> {
863 HasTypeParameters(// Type parameters.
866 // The kind of the rib used for type parameters.
870 /// The rib kind controls the translation of local
871 /// definitions (`Def::Local`) to upvars (`Def::Upvar`).
872 #[derive(Copy, Clone, Debug)]
874 /// No translation needs to be applied.
877 /// We passed through a closure scope at the given node ID.
878 /// Translate upvars as appropriate.
879 ClosureRibKind(NodeId /* func id */),
881 /// We passed through an impl or trait and are now in one of its
882 /// methods or associated types. Allow references to ty params that impl or trait
883 /// binds. Disallow any other upvars (including other ty params that are
885 TraitOrImplItemRibKind,
887 /// We passed through an item scope. Disallow upvars.
890 /// We're in a constant item. Can't refer to dynamic stuff.
893 /// We passed through a module.
894 ModuleRibKind(Module<'a>),
896 /// We passed through a `macro_rules!` statement
897 MacroDefinition(DefId),
899 /// All bindings in this rib are type parameters that can't be used
900 /// from the default of a type parameter because they're not declared
901 /// before said type parameter. Also see the `visit_generics` override.
902 ForwardTyParamBanRibKind,
907 /// A rib represents a scope names can live in. Note that these appear in many places, not just
908 /// around braces. At any place where the list of accessible names (of the given namespace)
909 /// changes or a new restrictions on the name accessibility are introduced, a new rib is put onto a
910 /// stack. This may be, for example, a `let` statement (because it introduces variables), a macro,
913 /// Different [rib kinds](enum.RibKind) are transparent for different names.
915 /// The resolution keeps a separate stack of ribs as it traverses the AST for each namespace. When
916 /// resolving, the name is looked up from inside out.
919 bindings: FxHashMap<Ident, Def>,
924 fn new(kind: RibKind<'a>) -> Rib<'a> {
926 bindings: FxHashMap(),
932 /// An intermediate resolution result.
934 /// This refers to the thing referred by a name. The difference between `Def` and `Item` is that
935 /// items are visible in their whole block, while defs only from the place they are defined
937 enum LexicalScopeBinding<'a> {
938 Item(&'a NameBinding<'a>),
942 impl<'a> LexicalScopeBinding<'a> {
943 fn item(self) -> Option<&'a NameBinding<'a>> {
945 LexicalScopeBinding::Item(binding) => Some(binding),
950 fn def(self) -> Def {
952 LexicalScopeBinding::Item(binding) => binding.def(),
953 LexicalScopeBinding::Def(def) => def,
958 #[derive(Copy, Clone, Debug)]
959 pub enum ModuleOrUniformRoot<'a> {
963 /// The `{{root}}` (`CrateRoot` aka "global") / `extern` initial segment
964 /// in which external crates resolve, and also `crate` (only in `{{root}}`,
965 /// but *not* `extern`), in the Rust 2018 edition.
969 #[derive(Clone, Debug)]
970 enum PathResult<'a> {
971 Module(ModuleOrUniformRoot<'a>),
972 NonModule(PathResolution),
974 Failed(Span, String, bool /* is the error from the last segment? */),
978 /// An anonymous module, eg. just a block.
983 /// { // This is an anonymous module
984 /// f(); // This resolves to (2) as we are inside the block.
987 /// f(); // Resolves to (1)
991 /// Any module with a name.
995 /// * A normal module ‒ either `mod from_file;` or `mod from_block { }`.
996 /// * A trait or an enum (it implicitly contains associated types, methods and variant
1001 /// One node in the tree of modules.
1002 pub struct ModuleData<'a> {
1003 parent: Option<Module<'a>>,
1006 // The def id of the closest normal module (`mod`) ancestor (including this module).
1007 normal_ancestor_id: DefId,
1009 resolutions: RefCell<FxHashMap<(Ident, Namespace), &'a RefCell<NameResolution<'a>>>>,
1010 legacy_macro_resolutions: RefCell<Vec<(Mark, Ident, MacroKind, Option<Def>)>>,
1011 macro_resolutions: RefCell<Vec<(Box<[Ident]>, Span)>>,
1013 // Macro invocations that can expand into items in this module.
1014 unresolved_invocations: RefCell<FxHashSet<Mark>>,
1016 no_implicit_prelude: bool,
1018 glob_importers: RefCell<Vec<&'a ImportDirective<'a>>>,
1019 globs: RefCell<Vec<&'a ImportDirective<'a>>>,
1021 // Used to memoize the traits in this module for faster searches through all traits in scope.
1022 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
1024 // Whether this module is populated. If not populated, any attempt to
1025 // access the children must be preceded with a
1026 // `populate_module_if_necessary` call.
1027 populated: Cell<bool>,
1029 /// Span of the module itself. Used for error reporting.
1035 type Module<'a> = &'a ModuleData<'a>;
1037 impl<'a> ModuleData<'a> {
1038 fn new(parent: Option<Module<'a>>,
1040 normal_ancestor_id: DefId,
1042 span: Span) -> Self {
1047 resolutions: RefCell::new(FxHashMap()),
1048 legacy_macro_resolutions: RefCell::new(Vec::new()),
1049 macro_resolutions: RefCell::new(Vec::new()),
1050 unresolved_invocations: RefCell::new(FxHashSet()),
1051 no_implicit_prelude: false,
1052 glob_importers: RefCell::new(Vec::new()),
1053 globs: RefCell::new(Vec::new()),
1054 traits: RefCell::new(None),
1055 populated: Cell::new(normal_ancestor_id.is_local()),
1061 fn for_each_child<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
1062 for (&(ident, ns), name_resolution) in self.resolutions.borrow().iter() {
1063 name_resolution.borrow().binding.map(|binding| f(ident, ns, binding));
1067 fn for_each_child_stable<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
1068 let resolutions = self.resolutions.borrow();
1069 let mut resolutions = resolutions.iter().collect::<Vec<_>>();
1070 resolutions.sort_by_cached_key(|&(&(ident, ns), _)| (ident.as_str(), ns));
1071 for &(&(ident, ns), &resolution) in resolutions.iter() {
1072 resolution.borrow().binding.map(|binding| f(ident, ns, binding));
1076 fn def(&self) -> Option<Def> {
1078 ModuleKind::Def(def, _) => Some(def),
1083 fn def_id(&self) -> Option<DefId> {
1084 self.def().as_ref().map(Def::def_id)
1087 // `self` resolves to the first module ancestor that `is_normal`.
1088 fn is_normal(&self) -> bool {
1090 ModuleKind::Def(Def::Mod(_), _) => true,
1095 fn is_trait(&self) -> bool {
1097 ModuleKind::Def(Def::Trait(_), _) => true,
1102 fn is_local(&self) -> bool {
1103 self.normal_ancestor_id.is_local()
1106 fn nearest_item_scope(&'a self) -> Module<'a> {
1107 if self.is_trait() { self.parent.unwrap() } else { self }
1111 impl<'a> fmt::Debug for ModuleData<'a> {
1112 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1113 write!(f, "{:?}", self.def())
1117 /// Records a possibly-private value, type, or module definition.
1118 #[derive(Clone, Debug)]
1119 pub struct NameBinding<'a> {
1120 kind: NameBindingKind<'a>,
1123 vis: ty::Visibility,
1126 pub trait ToNameBinding<'a> {
1127 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
1130 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
1131 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
1136 #[derive(Clone, Debug)]
1137 enum NameBindingKind<'a> {
1138 Def(Def, /* is_macro_export */ bool),
1141 binding: &'a NameBinding<'a>,
1142 directive: &'a ImportDirective<'a>,
1146 b1: &'a NameBinding<'a>,
1147 b2: &'a NameBinding<'a>,
1151 struct PrivacyError<'a>(Span, Name, &'a NameBinding<'a>);
1153 struct UseError<'a> {
1154 err: DiagnosticBuilder<'a>,
1155 /// Attach `use` statements for these candidates
1156 candidates: Vec<ImportSuggestion>,
1157 /// The node id of the module to place the use statements in
1159 /// Whether the diagnostic should state that it's "better"
1163 struct AmbiguityError<'a> {
1167 b1: &'a NameBinding<'a>,
1168 b2: &'a NameBinding<'a>,
1171 impl<'a> NameBinding<'a> {
1172 fn module(&self) -> Option<Module<'a>> {
1174 NameBindingKind::Module(module) => Some(module),
1175 NameBindingKind::Import { binding, .. } => binding.module(),
1180 fn def(&self) -> Def {
1182 NameBindingKind::Def(def, _) => def,
1183 NameBindingKind::Module(module) => module.def().unwrap(),
1184 NameBindingKind::Import { binding, .. } => binding.def(),
1185 NameBindingKind::Ambiguity { .. } => Def::Err,
1189 fn def_ignoring_ambiguity(&self) -> Def {
1191 NameBindingKind::Import { binding, .. } => binding.def_ignoring_ambiguity(),
1192 NameBindingKind::Ambiguity { b1, .. } => b1.def_ignoring_ambiguity(),
1197 fn get_macro<'b: 'a>(&self, resolver: &mut Resolver<'a, 'b>) -> Lrc<SyntaxExtension> {
1198 resolver.get_macro(self.def_ignoring_ambiguity())
1201 // We sometimes need to treat variants as `pub` for backwards compatibility
1202 fn pseudo_vis(&self) -> ty::Visibility {
1203 if self.is_variant() && self.def().def_id().is_local() {
1204 ty::Visibility::Public
1210 fn is_variant(&self) -> bool {
1212 NameBindingKind::Def(Def::Variant(..), _) |
1213 NameBindingKind::Def(Def::VariantCtor(..), _) => true,
1218 fn is_extern_crate(&self) -> bool {
1220 NameBindingKind::Import {
1221 directive: &ImportDirective {
1222 subclass: ImportDirectiveSubclass::ExternCrate(_), ..
1229 fn is_import(&self) -> bool {
1231 NameBindingKind::Import { .. } => true,
1236 fn is_renamed_extern_crate(&self) -> bool {
1237 if let NameBindingKind::Import { directive, ..} = self.kind {
1238 if let ImportDirectiveSubclass::ExternCrate(Some(_)) = directive.subclass {
1245 fn is_glob_import(&self) -> bool {
1247 NameBindingKind::Import { directive, .. } => directive.is_glob(),
1248 NameBindingKind::Ambiguity { b1, .. } => b1.is_glob_import(),
1253 fn is_importable(&self) -> bool {
1255 Def::AssociatedConst(..) | Def::Method(..) | Def::AssociatedTy(..) => false,
1260 fn is_macro_def(&self) -> bool {
1262 NameBindingKind::Def(Def::Macro(..), _) => true,
1267 fn descr(&self) -> &'static str {
1268 if self.is_extern_crate() { "extern crate" } else { self.def().kind_name() }
1272 /// Interns the names of the primitive types.
1274 /// All other types are defined somewhere and possibly imported, but the primitive ones need
1275 /// special handling, since they have no place of origin.
1276 struct PrimitiveTypeTable {
1277 primitive_types: FxHashMap<Name, PrimTy>,
1280 impl PrimitiveTypeTable {
1281 fn new() -> PrimitiveTypeTable {
1282 let mut table = PrimitiveTypeTable { primitive_types: FxHashMap() };
1284 table.intern("bool", Bool);
1285 table.intern("char", Char);
1286 table.intern("f32", Float(FloatTy::F32));
1287 table.intern("f64", Float(FloatTy::F64));
1288 table.intern("isize", Int(IntTy::Isize));
1289 table.intern("i8", Int(IntTy::I8));
1290 table.intern("i16", Int(IntTy::I16));
1291 table.intern("i32", Int(IntTy::I32));
1292 table.intern("i64", Int(IntTy::I64));
1293 table.intern("i128", Int(IntTy::I128));
1294 table.intern("str", Str);
1295 table.intern("usize", Uint(UintTy::Usize));
1296 table.intern("u8", Uint(UintTy::U8));
1297 table.intern("u16", Uint(UintTy::U16));
1298 table.intern("u32", Uint(UintTy::U32));
1299 table.intern("u64", Uint(UintTy::U64));
1300 table.intern("u128", Uint(UintTy::U128));
1304 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1305 self.primitive_types.insert(Symbol::intern(string), primitive_type);
1309 /// The main resolver class.
1311 /// This is the visitor that walks the whole crate.
1312 pub struct Resolver<'a, 'b: 'a> {
1313 session: &'a Session,
1316 pub definitions: Definitions,
1318 graph_root: Module<'a>,
1320 prelude: Option<Module<'a>>,
1321 extern_prelude: FxHashSet<Name>,
1323 /// n.b. This is used only for better diagnostics, not name resolution itself.
1324 has_self: FxHashSet<DefId>,
1326 /// Names of fields of an item `DefId` accessible with dot syntax.
1327 /// Used for hints during error reporting.
1328 field_names: FxHashMap<DefId, Vec<Name>>,
1330 /// All imports known to succeed or fail.
1331 determined_imports: Vec<&'a ImportDirective<'a>>,
1333 /// All non-determined imports.
1334 indeterminate_imports: Vec<&'a ImportDirective<'a>>,
1336 /// The module that represents the current item scope.
1337 current_module: Module<'a>,
1339 /// The current set of local scopes for types and values.
1340 /// FIXME #4948: Reuse ribs to avoid allocation.
1341 ribs: PerNS<Vec<Rib<'a>>>,
1343 /// The current set of local scopes, for labels.
1344 label_ribs: Vec<Rib<'a>>,
1346 /// The trait that the current context can refer to.
1347 current_trait_ref: Option<(Module<'a>, TraitRef)>,
1349 /// The current self type if inside an impl (used for better errors).
1350 current_self_type: Option<Ty>,
1352 /// The idents for the primitive types.
1353 primitive_type_table: PrimitiveTypeTable,
1356 import_map: ImportMap,
1357 pub freevars: FreevarMap,
1358 freevars_seen: NodeMap<NodeMap<usize>>,
1359 pub export_map: ExportMap,
1360 pub trait_map: TraitMap,
1362 /// A map from nodes to anonymous modules.
1363 /// Anonymous modules are pseudo-modules that are implicitly created around items
1364 /// contained within blocks.
1366 /// For example, if we have this:
1374 /// There will be an anonymous module created around `g` with the ID of the
1375 /// entry block for `f`.
1376 block_map: NodeMap<Module<'a>>,
1377 module_map: FxHashMap<DefId, Module<'a>>,
1378 extern_module_map: FxHashMap<(DefId, bool /* MacrosOnly? */), Module<'a>>,
1380 pub make_glob_map: bool,
1381 /// Maps imports to the names of items actually imported (this actually maps
1382 /// all imports, but only glob imports are actually interesting).
1383 pub glob_map: GlobMap,
1385 used_imports: FxHashSet<(NodeId, Namespace)>,
1386 pub maybe_unused_trait_imports: NodeSet,
1387 pub maybe_unused_extern_crates: Vec<(NodeId, Span)>,
1389 /// A list of labels as of yet unused. Labels will be removed from this map when
1390 /// they are used (in a `break` or `continue` statement)
1391 pub unused_labels: FxHashMap<NodeId, Span>,
1393 /// privacy errors are delayed until the end in order to deduplicate them
1394 privacy_errors: Vec<PrivacyError<'a>>,
1395 /// ambiguity errors are delayed for deduplication
1396 ambiguity_errors: Vec<AmbiguityError<'a>>,
1397 /// `use` injections are delayed for better placement and deduplication
1398 use_injections: Vec<UseError<'a>>,
1399 /// `use` injections for proc macros wrongly imported with #[macro_use]
1400 proc_mac_errors: Vec<macros::ProcMacError>,
1401 /// crate-local macro expanded `macro_export` referred to by a module-relative path
1402 macro_expanded_macro_export_errors: BTreeSet<(Span, Span)>,
1403 /// macro-expanded `macro_rules` shadowing existing macros
1404 disallowed_shadowing: Vec<&'a LegacyBinding<'a>>,
1406 arenas: &'a ResolverArenas<'a>,
1407 dummy_binding: &'a NameBinding<'a>,
1409 crate_loader: &'a mut CrateLoader<'b>,
1410 macro_names: FxHashSet<Ident>,
1411 macro_prelude: FxHashMap<Name, &'a NameBinding<'a>>,
1412 pub all_macros: FxHashMap<Name, Def>,
1413 macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>,
1414 macro_defs: FxHashMap<Mark, DefId>,
1415 local_macro_def_scopes: FxHashMap<NodeId, Module<'a>>,
1416 pub whitelisted_legacy_custom_derives: Vec<Name>,
1417 pub found_unresolved_macro: bool,
1419 /// List of crate local macros that we need to warn about as being unused.
1420 /// Right now this only includes macro_rules! macros, and macros 2.0.
1421 unused_macros: FxHashSet<DefId>,
1423 /// Maps the `Mark` of an expansion to its containing module or block.
1424 invocations: FxHashMap<Mark, &'a InvocationData<'a>>,
1426 /// Avoid duplicated errors for "name already defined".
1427 name_already_seen: FxHashMap<Name, Span>,
1429 /// A set of procedural macros imported by `#[macro_use]` that have already been warned about
1430 warned_proc_macros: FxHashSet<Name>,
1432 potentially_unused_imports: Vec<&'a ImportDirective<'a>>,
1434 /// This table maps struct IDs into struct constructor IDs,
1435 /// it's not used during normal resolution, only for better error reporting.
1436 struct_constructors: DefIdMap<(Def, ty::Visibility)>,
1438 /// Only used for better errors on `fn(): fn()`
1439 current_type_ascription: Vec<Span>,
1441 injected_crate: Option<Module<'a>>,
1443 /// Only supposed to be used by rustdoc, otherwise should be false.
1444 pub ignore_extern_prelude_feature: bool,
1447 /// Nothing really interesting here, it just provides memory for the rest of the crate.
1448 pub struct ResolverArenas<'a> {
1449 modules: arena::TypedArena<ModuleData<'a>>,
1450 local_modules: RefCell<Vec<Module<'a>>>,
1451 name_bindings: arena::TypedArena<NameBinding<'a>>,
1452 import_directives: arena::TypedArena<ImportDirective<'a>>,
1453 name_resolutions: arena::TypedArena<RefCell<NameResolution<'a>>>,
1454 invocation_data: arena::TypedArena<InvocationData<'a>>,
1455 legacy_bindings: arena::TypedArena<LegacyBinding<'a>>,
1458 impl<'a> ResolverArenas<'a> {
1459 fn alloc_module(&'a self, module: ModuleData<'a>) -> Module<'a> {
1460 let module = self.modules.alloc(module);
1461 if module.def_id().map(|def_id| def_id.is_local()).unwrap_or(true) {
1462 self.local_modules.borrow_mut().push(module);
1466 fn local_modules(&'a self) -> ::std::cell::Ref<'a, Vec<Module<'a>>> {
1467 self.local_modules.borrow()
1469 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1470 self.name_bindings.alloc(name_binding)
1472 fn alloc_import_directive(&'a self, import_directive: ImportDirective<'a>)
1473 -> &'a ImportDirective {
1474 self.import_directives.alloc(import_directive)
1476 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1477 self.name_resolutions.alloc(Default::default())
1479 fn alloc_invocation_data(&'a self, expansion_data: InvocationData<'a>)
1480 -> &'a InvocationData<'a> {
1481 self.invocation_data.alloc(expansion_data)
1483 fn alloc_legacy_binding(&'a self, binding: LegacyBinding<'a>) -> &'a LegacyBinding<'a> {
1484 self.legacy_bindings.alloc(binding)
1488 impl<'a, 'b: 'a, 'cl: 'b> ty::DefIdTree for &'a Resolver<'b, 'cl> {
1489 fn parent(self, id: DefId) -> Option<DefId> {
1491 LOCAL_CRATE => self.definitions.def_key(id.index).parent,
1492 _ => self.cstore.def_key(id).parent,
1493 }.map(|index| DefId { index, ..id })
1497 /// This interface is used through the AST→HIR step, to embed full paths into the HIR. After that
1498 /// the resolver is no longer needed as all the relevant information is inline.
1499 impl<'a, 'cl> hir::lowering::Resolver for Resolver<'a, 'cl> {
1500 fn resolve_hir_path(&mut self, path: &mut hir::Path, is_value: bool) {
1501 self.resolve_hir_path_cb(path, is_value,
1502 |resolver, span, error| resolve_error(resolver, span, error))
1505 fn resolve_str_path(
1508 crate_root: Option<&str>,
1509 components: &[&str],
1510 args: Option<P<hir::GenericArgs>>,
1513 let mut segments = iter::once(keywords::CrateRoot.ident())
1515 crate_root.into_iter()
1516 .chain(components.iter().cloned())
1517 .map(Ident::from_str)
1518 ).map(hir::PathSegment::from_ident).collect::<Vec<_>>();
1520 if let Some(args) = args {
1521 let ident = segments.last().unwrap().ident;
1522 *segments.last_mut().unwrap() = hir::PathSegment {
1529 let mut path = hir::Path {
1532 segments: segments.into(),
1535 self.resolve_hir_path(&mut path, is_value);
1539 fn get_resolution(&mut self, id: NodeId) -> Option<PathResolution> {
1540 self.def_map.get(&id).cloned()
1543 fn get_import(&mut self, id: NodeId) -> PerNS<Option<PathResolution>> {
1544 self.import_map.get(&id).cloned().unwrap_or_default()
1547 fn definitions(&mut self) -> &mut Definitions {
1548 &mut self.definitions
1552 impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
1553 /// Rustdoc uses this to resolve things in a recoverable way. ResolutionError<'a>
1554 /// isn't something that can be returned because it can't be made to live that long,
1555 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
1556 /// just that an error occurred.
1557 pub fn resolve_str_path_error(&mut self, span: Span, path_str: &str, is_value: bool)
1558 -> Result<hir::Path, ()> {
1560 let mut errored = false;
1562 let mut path = if path_str.starts_with("::") {
1566 segments: iter::once(keywords::CrateRoot.ident()).chain({
1567 path_str.split("::").skip(1).map(Ident::from_str)
1568 }).map(hir::PathSegment::from_ident).collect(),
1574 segments: path_str.split("::").map(Ident::from_str)
1575 .map(hir::PathSegment::from_ident).collect(),
1578 self.resolve_hir_path_cb(&mut path, is_value, |_, _, _| errored = true);
1579 if errored || path.def == Def::Err {
1586 /// resolve_hir_path, but takes a callback in case there was an error
1587 fn resolve_hir_path_cb<F>(&mut self, path: &mut hir::Path, is_value: bool, error_callback: F)
1588 where F: for<'c, 'b> FnOnce(&'c mut Resolver, Span, ResolutionError<'b>)
1590 let namespace = if is_value { ValueNS } else { TypeNS };
1591 let hir::Path { ref segments, span, ref mut def } = *path;
1592 let path: Vec<_> = segments.iter().map(|seg| seg.ident).collect();
1593 // FIXME (Manishearth): Intra doc links won't get warned of epoch changes
1594 match self.resolve_path(None, &path, Some(namespace), true, span, CrateLint::No) {
1595 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
1596 *def = module.def().unwrap(),
1597 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 =>
1598 *def = path_res.base_def(),
1599 PathResult::NonModule(..) => match self.resolve_path(
1607 PathResult::Failed(span, msg, _) => {
1608 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1612 PathResult::Module(ModuleOrUniformRoot::UniformRoot(_)) |
1613 PathResult::Indeterminate => unreachable!(),
1614 PathResult::Failed(span, msg, _) => {
1615 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1621 impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
1622 pub fn new(session: &'a Session,
1626 make_glob_map: MakeGlobMap,
1627 crate_loader: &'a mut CrateLoader<'crateloader>,
1628 arenas: &'a ResolverArenas<'a>)
1629 -> Resolver<'a, 'crateloader> {
1630 let root_def_id = DefId::local(CRATE_DEF_INDEX);
1631 let root_module_kind = ModuleKind::Def(Def::Mod(root_def_id), keywords::Invalid.name());
1632 let graph_root = arenas.alloc_module(ModuleData {
1633 no_implicit_prelude: attr::contains_name(&krate.attrs, "no_implicit_prelude"),
1634 ..ModuleData::new(None, root_module_kind, root_def_id, Mark::root(), krate.span)
1636 let mut module_map = FxHashMap();
1637 module_map.insert(DefId::local(CRATE_DEF_INDEX), graph_root);
1639 let mut definitions = Definitions::new();
1640 DefCollector::new(&mut definitions, Mark::root())
1641 .collect_root(crate_name, session.local_crate_disambiguator());
1643 let mut extern_prelude: FxHashSet<Name> =
1644 session.opts.externs.iter().map(|kv| Symbol::intern(kv.0)).collect();
1645 if !attr::contains_name(&krate.attrs, "no_core") {
1646 if !attr::contains_name(&krate.attrs, "no_std") {
1647 extern_prelude.insert(Symbol::intern("std"));
1649 extern_prelude.insert(Symbol::intern("core"));
1653 let mut invocations = FxHashMap();
1654 invocations.insert(Mark::root(),
1655 arenas.alloc_invocation_data(InvocationData::root(graph_root)));
1657 let mut macro_defs = FxHashMap();
1658 macro_defs.insert(Mark::root(), root_def_id);
1667 // The outermost module has def ID 0; this is not reflected in the
1673 has_self: FxHashSet(),
1674 field_names: FxHashMap(),
1676 determined_imports: Vec::new(),
1677 indeterminate_imports: Vec::new(),
1679 current_module: graph_root,
1681 value_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1682 type_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1683 macro_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1685 label_ribs: Vec::new(),
1687 current_trait_ref: None,
1688 current_self_type: None,
1690 primitive_type_table: PrimitiveTypeTable::new(),
1693 import_map: NodeMap(),
1694 freevars: NodeMap(),
1695 freevars_seen: NodeMap(),
1696 export_map: FxHashMap(),
1697 trait_map: NodeMap(),
1699 block_map: NodeMap(),
1700 extern_module_map: FxHashMap(),
1702 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1703 glob_map: NodeMap(),
1705 used_imports: FxHashSet(),
1706 maybe_unused_trait_imports: NodeSet(),
1707 maybe_unused_extern_crates: Vec::new(),
1709 unused_labels: FxHashMap(),
1711 privacy_errors: Vec::new(),
1712 ambiguity_errors: Vec::new(),
1713 use_injections: Vec::new(),
1714 proc_mac_errors: Vec::new(),
1715 disallowed_shadowing: Vec::new(),
1716 macro_expanded_macro_export_errors: BTreeSet::new(),
1719 dummy_binding: arenas.alloc_name_binding(NameBinding {
1720 kind: NameBindingKind::Def(Def::Err, false),
1721 expansion: Mark::root(),
1723 vis: ty::Visibility::Public,
1727 macro_names: FxHashSet(),
1728 macro_prelude: FxHashMap(),
1729 all_macros: FxHashMap(),
1730 macro_map: FxHashMap(),
1733 local_macro_def_scopes: FxHashMap(),
1734 name_already_seen: FxHashMap(),
1735 whitelisted_legacy_custom_derives: Vec::new(),
1736 warned_proc_macros: FxHashSet(),
1737 potentially_unused_imports: Vec::new(),
1738 struct_constructors: DefIdMap(),
1739 found_unresolved_macro: false,
1740 unused_macros: FxHashSet(),
1741 current_type_ascription: Vec::new(),
1742 injected_crate: None,
1743 ignore_extern_prelude_feature: false,
1747 pub fn arenas() -> ResolverArenas<'a> {
1749 modules: arena::TypedArena::new(),
1750 local_modules: RefCell::new(Vec::new()),
1751 name_bindings: arena::TypedArena::new(),
1752 import_directives: arena::TypedArena::new(),
1753 name_resolutions: arena::TypedArena::new(),
1754 invocation_data: arena::TypedArena::new(),
1755 legacy_bindings: arena::TypedArena::new(),
1759 /// Runs the function on each namespace.
1760 fn per_ns<F: FnMut(&mut Self, Namespace)>(&mut self, mut f: F) {
1766 fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
1768 match self.macro_defs.get(&ctxt.outer()) {
1769 Some(&def_id) => return def_id,
1770 None => ctxt.remove_mark(),
1775 /// Entry point to crate resolution.
1776 pub fn resolve_crate(&mut self, krate: &Crate) {
1777 ImportResolver { resolver: self }.finalize_imports();
1778 self.current_module = self.graph_root;
1779 self.finalize_current_module_macro_resolutions();
1781 visit::walk_crate(self, krate);
1783 check_unused::check_crate(self, krate);
1784 self.report_errors(krate);
1785 self.crate_loader.postprocess(krate);
1792 normal_ancestor_id: DefId,
1796 let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expansion, span);
1797 self.arenas.alloc_module(module)
1800 fn record_use(&mut self, ident: Ident, ns: Namespace, binding: &'a NameBinding<'a>, span: Span)
1801 -> bool /* true if an error was reported */ {
1802 match binding.kind {
1803 NameBindingKind::Import { directive, binding, ref used }
1806 directive.used.set(true);
1807 self.used_imports.insert((directive.id, ns));
1808 self.add_to_glob_map(directive.id, ident);
1809 self.record_use(ident, ns, binding, span)
1811 NameBindingKind::Import { .. } => false,
1812 NameBindingKind::Ambiguity { b1, b2 } => {
1813 self.ambiguity_errors.push(AmbiguityError {
1814 span, name: ident.name, lexical: false, b1, b2,
1822 fn add_to_glob_map(&mut self, id: NodeId, ident: Ident) {
1823 if self.make_glob_map {
1824 self.glob_map.entry(id).or_default().insert(ident.name);
1828 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1829 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1830 /// `ident` in the first scope that defines it (or None if no scopes define it).
1832 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1833 /// the items are defined in the block. For example,
1836 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1839 /// g(); // This resolves to the local variable `g` since it shadows the item.
1843 /// Invariant: This must only be called during main resolution, not during
1844 /// import resolution.
1845 fn resolve_ident_in_lexical_scope(&mut self,
1848 record_used_id: Option<NodeId>,
1850 -> Option<LexicalScopeBinding<'a>> {
1851 let record_used = record_used_id.is_some();
1852 assert!(ns == TypeNS || ns == ValueNS);
1854 ident.span = if ident.name == keywords::SelfType.name() {
1855 // FIXME(jseyfried) improve `Self` hygiene
1856 ident.span.with_ctxt(SyntaxContext::empty())
1861 ident = ident.modern_and_legacy();
1864 // Walk backwards up the ribs in scope.
1865 let mut module = self.graph_root;
1866 for i in (0 .. self.ribs[ns].len()).rev() {
1867 if let Some(def) = self.ribs[ns][i].bindings.get(&ident).cloned() {
1868 // The ident resolves to a type parameter or local variable.
1869 return Some(LexicalScopeBinding::Def(
1870 self.adjust_local_def(ns, i, def, record_used, path_span)
1874 module = match self.ribs[ns][i].kind {
1875 ModuleRibKind(module) => module,
1876 MacroDefinition(def) if def == self.macro_def(ident.span.ctxt()) => {
1877 // If an invocation of this macro created `ident`, give up on `ident`
1878 // and switch to `ident`'s source from the macro definition.
1879 ident.span.remove_mark();
1885 let item = self.resolve_ident_in_module_unadjusted(
1886 ModuleOrUniformRoot::Module(module),
1893 if let Ok(binding) = item {
1894 // The ident resolves to an item.
1895 return Some(LexicalScopeBinding::Item(binding));
1899 ModuleKind::Block(..) => {}, // We can see through blocks
1904 ident.span = ident.span.modern();
1905 let mut poisoned = None;
1907 let opt_module = if let Some(node_id) = record_used_id {
1908 self.hygienic_lexical_parent_with_compatibility_fallback(module, &mut ident.span,
1909 node_id, &mut poisoned)
1911 self.hygienic_lexical_parent(module, &mut ident.span)
1913 module = unwrap_or!(opt_module, break);
1914 let orig_current_module = self.current_module;
1915 self.current_module = module; // Lexical resolutions can never be a privacy error.
1916 let result = self.resolve_ident_in_module_unadjusted(
1917 ModuleOrUniformRoot::Module(module),
1924 self.current_module = orig_current_module;
1928 if let Some(node_id) = poisoned {
1929 self.session.buffer_lint_with_diagnostic(
1930 lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
1931 node_id, ident.span,
1932 &format!("cannot find {} `{}` in this scope", ns.descr(), ident),
1933 lint::builtin::BuiltinLintDiagnostics::
1934 ProcMacroDeriveResolutionFallback(ident.span),
1937 return Some(LexicalScopeBinding::Item(binding))
1939 Err(Determined) => continue,
1940 Err(Undetermined) =>
1941 span_bug!(ident.span, "undetermined resolution during main resolution pass"),
1945 if !module.no_implicit_prelude {
1946 // `record_used` means that we don't try to load crates during speculative resolution
1947 if record_used && ns == TypeNS && self.extern_prelude.contains(&ident.name) {
1948 if !self.session.features_untracked().extern_prelude &&
1949 !self.ignore_extern_prelude_feature {
1950 feature_err(&self.session.parse_sess, "extern_prelude",
1951 ident.span, GateIssue::Language,
1952 "access to extern crates through prelude is experimental").emit();
1955 let crate_id = self.crate_loader.process_path_extern(ident.name, ident.span);
1956 let crate_root = self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
1957 self.populate_module_if_necessary(crate_root);
1959 let binding = (crate_root, ty::Visibility::Public,
1960 ident.span, Mark::root()).to_name_binding(self.arenas);
1961 return Some(LexicalScopeBinding::Item(binding));
1963 if ns == TypeNS && is_known_tool(ident.name) {
1964 let binding = (Def::ToolMod, ty::Visibility::Public,
1965 ident.span, Mark::root()).to_name_binding(self.arenas);
1966 return Some(LexicalScopeBinding::Item(binding));
1968 if let Some(prelude) = self.prelude {
1969 if let Ok(binding) = self.resolve_ident_in_module_unadjusted(
1970 ModuleOrUniformRoot::Module(prelude),
1977 return Some(LexicalScopeBinding::Item(binding));
1985 fn hygienic_lexical_parent(&mut self, module: Module<'a>, span: &mut Span)
1986 -> Option<Module<'a>> {
1987 if !module.expansion.is_descendant_of(span.ctxt().outer()) {
1988 return Some(self.macro_def_scope(span.remove_mark()));
1991 if let ModuleKind::Block(..) = module.kind {
1992 return Some(module.parent.unwrap());
1998 fn hygienic_lexical_parent_with_compatibility_fallback(&mut self, module: Module<'a>,
1999 span: &mut Span, node_id: NodeId,
2000 poisoned: &mut Option<NodeId>)
2001 -> Option<Module<'a>> {
2002 if let module @ Some(..) = self.hygienic_lexical_parent(module, span) {
2006 // We need to support the next case under a deprecation warning
2009 // ---- begin: this comes from a proc macro derive
2010 // mod implementation_details {
2011 // // Note that `MyStruct` is not in scope here.
2012 // impl SomeTrait for MyStruct { ... }
2016 // So we have to fall back to the module's parent during lexical resolution in this case.
2017 if let Some(parent) = module.parent {
2018 // Inner module is inside the macro, parent module is outside of the macro.
2019 if module.expansion != parent.expansion &&
2020 module.expansion.is_descendant_of(parent.expansion) {
2021 // The macro is a proc macro derive
2022 if module.expansion.looks_like_proc_macro_derive() {
2023 if parent.expansion.is_descendant_of(span.ctxt().outer()) {
2024 *poisoned = Some(node_id);
2025 return module.parent;
2034 fn resolve_ident_in_module(&mut self,
2035 module: ModuleOrUniformRoot<'a>,
2040 -> Result<&'a NameBinding<'a>, Determinacy> {
2041 ident.span = ident.span.modern();
2042 let orig_current_module = self.current_module;
2043 if let ModuleOrUniformRoot::Module(module) = module {
2044 if let Some(def) = ident.span.adjust(module.expansion) {
2045 self.current_module = self.macro_def_scope(def);
2048 let result = self.resolve_ident_in_module_unadjusted(
2049 module, ident, ns, false, record_used, span,
2051 self.current_module = orig_current_module;
2055 fn resolve_crate_root(&mut self, ident: Ident) -> Module<'a> {
2056 let mut ctxt = ident.span.ctxt();
2057 let mark = if ident.name == keywords::DollarCrate.name() {
2058 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
2059 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
2060 // as described in `SyntaxContext::apply_mark`, so we ignore prepended modern marks.
2061 // FIXME: This is only a guess and it doesn't work correctly for `macro_rules!`
2062 // definitions actually produced by `macro` and `macro` definitions produced by
2063 // `macro_rules!`, but at least such configurations are not stable yet.
2064 ctxt = ctxt.modern_and_legacy();
2065 let mut iter = ctxt.marks().into_iter().rev().peekable();
2066 let mut result = None;
2067 // Find the last modern mark from the end if it exists.
2068 while let Some(&(mark, transparency)) = iter.peek() {
2069 if transparency == Transparency::Opaque {
2070 result = Some(mark);
2076 // Then find the last legacy mark from the end if it exists.
2077 for (mark, transparency) in iter {
2078 if transparency == Transparency::SemiTransparent {
2079 result = Some(mark);
2086 ctxt = ctxt.modern();
2087 ctxt.adjust(Mark::root())
2089 let module = match mark {
2090 Some(def) => self.macro_def_scope(def),
2091 None => return self.graph_root,
2093 self.get_module(DefId { index: CRATE_DEF_INDEX, ..module.normal_ancestor_id })
2096 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
2097 let mut module = self.get_module(module.normal_ancestor_id);
2098 while module.span.ctxt().modern() != *ctxt {
2099 let parent = module.parent.unwrap_or_else(|| self.macro_def_scope(ctxt.remove_mark()));
2100 module = self.get_module(parent.normal_ancestor_id);
2107 // We maintain a list of value ribs and type ribs.
2109 // Simultaneously, we keep track of the current position in the module
2110 // graph in the `current_module` pointer. When we go to resolve a name in
2111 // the value or type namespaces, we first look through all the ribs and
2112 // then query the module graph. When we resolve a name in the module
2113 // namespace, we can skip all the ribs (since nested modules are not
2114 // allowed within blocks in Rust) and jump straight to the current module
2117 // Named implementations are handled separately. When we find a method
2118 // call, we consult the module node to find all of the implementations in
2119 // scope. This information is lazily cached in the module node. We then
2120 // generate a fake "implementation scope" containing all the
2121 // implementations thus found, for compatibility with old resolve pass.
2123 pub fn with_scope<F, T>(&mut self, id: NodeId, f: F) -> T
2124 where F: FnOnce(&mut Resolver) -> T
2126 let id = self.definitions.local_def_id(id);
2127 let module = self.module_map.get(&id).cloned(); // clones a reference
2128 if let Some(module) = module {
2129 // Move down in the graph.
2130 let orig_module = replace(&mut self.current_module, module);
2131 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(module)));
2132 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(module)));
2134 self.finalize_current_module_macro_resolutions();
2137 self.current_module = orig_module;
2138 self.ribs[ValueNS].pop();
2139 self.ribs[TypeNS].pop();
2146 /// Searches the current set of local scopes for labels. Returns the first non-None label that
2147 /// is returned by the given predicate function
2149 /// Stops after meeting a closure.
2150 fn search_label<P, R>(&self, mut ident: Ident, pred: P) -> Option<R>
2151 where P: Fn(&Rib, Ident) -> Option<R>
2153 for rib in self.label_ribs.iter().rev() {
2156 // If an invocation of this macro created `ident`, give up on `ident`
2157 // and switch to `ident`'s source from the macro definition.
2158 MacroDefinition(def) => {
2159 if def == self.macro_def(ident.span.ctxt()) {
2160 ident.span.remove_mark();
2164 // Do not resolve labels across function boundary
2168 let r = pred(rib, ident);
2176 fn resolve_item(&mut self, item: &Item) {
2177 let name = item.ident.name;
2178 debug!("(resolving item) resolving {}", name);
2181 ItemKind::Ty(_, ref generics) |
2182 ItemKind::Fn(_, _, ref generics, _) |
2183 ItemKind::Existential(_, ref generics) => {
2184 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind),
2185 |this| visit::walk_item(this, item));
2188 ItemKind::Enum(_, ref generics) |
2189 ItemKind::Struct(_, ref generics) |
2190 ItemKind::Union(_, ref generics) => {
2191 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2192 let item_def_id = this.definitions.local_def_id(item.id);
2193 if this.session.features_untracked().self_in_typedefs {
2194 this.with_self_rib(Def::SelfTy(None, Some(item_def_id)), |this| {
2195 visit::walk_item(this, item);
2198 visit::walk_item(this, item);
2203 ItemKind::Impl(.., ref generics, ref opt_trait_ref, ref self_type, ref impl_items) =>
2204 self.resolve_implementation(generics,
2210 ItemKind::Trait(.., ref generics, ref bounds, ref trait_items) => {
2211 // Create a new rib for the trait-wide type parameters.
2212 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2213 let local_def_id = this.definitions.local_def_id(item.id);
2214 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2215 this.visit_generics(generics);
2216 walk_list!(this, visit_param_bound, bounds);
2218 for trait_item in trait_items {
2219 let type_parameters = HasTypeParameters(&trait_item.generics,
2220 TraitOrImplItemRibKind);
2221 this.with_type_parameter_rib(type_parameters, |this| {
2222 match trait_item.node {
2223 TraitItemKind::Const(ref ty, ref default) => {
2226 // Only impose the restrictions of
2227 // ConstRibKind for an actual constant
2228 // expression in a provided default.
2229 if let Some(ref expr) = *default{
2230 this.with_constant_rib(|this| {
2231 this.visit_expr(expr);
2235 TraitItemKind::Method(_, _) => {
2236 visit::walk_trait_item(this, trait_item)
2238 TraitItemKind::Type(..) => {
2239 visit::walk_trait_item(this, trait_item)
2241 TraitItemKind::Macro(_) => {
2242 panic!("unexpanded macro in resolve!")
2251 ItemKind::TraitAlias(ref generics, ref bounds) => {
2252 // Create a new rib for the trait-wide type parameters.
2253 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2254 let local_def_id = this.definitions.local_def_id(item.id);
2255 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2256 this.visit_generics(generics);
2257 walk_list!(this, visit_param_bound, bounds);
2262 ItemKind::Mod(_) | ItemKind::ForeignMod(_) => {
2263 self.with_scope(item.id, |this| {
2264 visit::walk_item(this, item);
2268 ItemKind::Static(ref ty, _, ref expr) |
2269 ItemKind::Const(ref ty, ref expr) => {
2270 self.with_item_rib(|this| {
2272 this.with_constant_rib(|this| {
2273 this.visit_expr(expr);
2278 ItemKind::Use(ref use_tree) => {
2279 // Imports are resolved as global by default, add starting root segment.
2281 segments: use_tree.prefix.make_root().into_iter().collect(),
2282 span: use_tree.span,
2284 self.resolve_use_tree(item.id, use_tree.span, item.id, use_tree, &path);
2287 ItemKind::ExternCrate(_) | ItemKind::MacroDef(..) | ItemKind::GlobalAsm(_) => {
2288 // do nothing, these are just around to be encoded
2291 ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"),
2295 /// For the most part, use trees are desugared into `ImportDirective` instances
2296 /// when building the reduced graph (see `build_reduced_graph_for_use_tree`). But
2297 /// there is one special case we handle here: an empty nested import like
2298 /// `a::{b::{}}`, which desugares into...no import directives.
2299 fn resolve_use_tree(
2304 use_tree: &ast::UseTree,
2307 match use_tree.kind {
2308 ast::UseTreeKind::Nested(ref items) => {
2310 segments: prefix.segments
2312 .chain(use_tree.prefix.segments.iter())
2315 span: prefix.span.to(use_tree.prefix.span),
2318 if items.len() == 0 {
2319 // Resolve prefix of an import with empty braces (issue #28388).
2320 self.smart_resolve_path_with_crate_lint(
2324 PathSource::ImportPrefix,
2325 CrateLint::UsePath { root_id, root_span },
2328 for &(ref tree, nested_id) in items {
2329 self.resolve_use_tree(root_id, root_span, nested_id, tree, &path);
2333 ast::UseTreeKind::Simple(..) => {},
2334 ast::UseTreeKind::Glob => {},
2338 fn with_type_parameter_rib<'b, F>(&'b mut self, type_parameters: TypeParameters<'a, 'b>, f: F)
2339 where F: FnOnce(&mut Resolver)
2341 match type_parameters {
2342 HasTypeParameters(generics, rib_kind) => {
2343 let mut function_type_rib = Rib::new(rib_kind);
2344 let mut seen_bindings = FxHashMap();
2345 for param in &generics.params {
2347 GenericParamKind::Lifetime { .. } => {}
2348 GenericParamKind::Type { .. } => {
2349 let ident = param.ident.modern();
2350 debug!("with_type_parameter_rib: {}", param.id);
2352 if seen_bindings.contains_key(&ident) {
2353 let span = seen_bindings.get(&ident).unwrap();
2354 let err = ResolutionError::NameAlreadyUsedInTypeParameterList(
2358 resolve_error(self, param.ident.span, err);
2360 seen_bindings.entry(ident).or_insert(param.ident.span);
2362 // Plain insert (no renaming).
2363 let def = Def::TyParam(self.definitions.local_def_id(param.id));
2364 function_type_rib.bindings.insert(ident, def);
2365 self.record_def(param.id, PathResolution::new(def));
2369 self.ribs[TypeNS].push(function_type_rib);
2372 NoTypeParameters => {
2379 if let HasTypeParameters(..) = type_parameters {
2380 self.ribs[TypeNS].pop();
2384 fn with_label_rib<F>(&mut self, f: F)
2385 where F: FnOnce(&mut Resolver)
2387 self.label_ribs.push(Rib::new(NormalRibKind));
2389 self.label_ribs.pop();
2392 fn with_item_rib<F>(&mut self, f: F)
2393 where F: FnOnce(&mut Resolver)
2395 self.ribs[ValueNS].push(Rib::new(ItemRibKind));
2396 self.ribs[TypeNS].push(Rib::new(ItemRibKind));
2398 self.ribs[TypeNS].pop();
2399 self.ribs[ValueNS].pop();
2402 fn with_constant_rib<F>(&mut self, f: F)
2403 where F: FnOnce(&mut Resolver)
2405 self.ribs[ValueNS].push(Rib::new(ConstantItemRibKind));
2406 self.label_ribs.push(Rib::new(ConstantItemRibKind));
2408 self.label_ribs.pop();
2409 self.ribs[ValueNS].pop();
2412 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2413 where F: FnOnce(&mut Resolver) -> T
2415 // Handle nested impls (inside fn bodies)
2416 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2417 let result = f(self);
2418 self.current_self_type = previous_value;
2422 /// This is called to resolve a trait reference from an `impl` (i.e. `impl Trait for Foo`)
2423 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
2424 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2426 let mut new_val = None;
2427 let mut new_id = None;
2428 if let Some(trait_ref) = opt_trait_ref {
2429 let path: Vec<_> = trait_ref.path.segments.iter()
2430 .map(|seg| seg.ident)
2432 let def = self.smart_resolve_path_fragment(
2436 trait_ref.path.span,
2437 PathSource::Trait(AliasPossibility::No),
2438 CrateLint::SimplePath(trait_ref.ref_id),
2440 if def != Def::Err {
2441 new_id = Some(def.def_id());
2442 let span = trait_ref.path.span;
2443 if let PathResult::Module(ModuleOrUniformRoot::Module(module)) =
2450 CrateLint::SimplePath(trait_ref.ref_id),
2453 new_val = Some((module, trait_ref.clone()));
2457 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2458 let result = f(self, new_id);
2459 self.current_trait_ref = original_trait_ref;
2463 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2464 where F: FnOnce(&mut Resolver)
2466 let mut self_type_rib = Rib::new(NormalRibKind);
2468 // plain insert (no renaming, types are not currently hygienic....)
2469 self_type_rib.bindings.insert(keywords::SelfType.ident(), self_def);
2470 self.ribs[TypeNS].push(self_type_rib);
2472 self.ribs[TypeNS].pop();
2475 fn resolve_implementation(&mut self,
2476 generics: &Generics,
2477 opt_trait_reference: &Option<TraitRef>,
2480 impl_items: &[ImplItem]) {
2481 // If applicable, create a rib for the type parameters.
2482 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2483 // Dummy self type for better errors if `Self` is used in the trait path.
2484 this.with_self_rib(Def::SelfTy(None, None), |this| {
2485 // Resolve the trait reference, if necessary.
2486 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2487 let item_def_id = this.definitions.local_def_id(item_id);
2488 this.with_self_rib(Def::SelfTy(trait_id, Some(item_def_id)), |this| {
2489 if let Some(trait_ref) = opt_trait_reference.as_ref() {
2490 // Resolve type arguments in the trait path.
2491 visit::walk_trait_ref(this, trait_ref);
2493 // Resolve the self type.
2494 this.visit_ty(self_type);
2495 // Resolve the type parameters.
2496 this.visit_generics(generics);
2497 // Resolve the items within the impl.
2498 this.with_current_self_type(self_type, |this| {
2499 for impl_item in impl_items {
2500 this.resolve_visibility(&impl_item.vis);
2502 // We also need a new scope for the impl item type parameters.
2503 let type_parameters = HasTypeParameters(&impl_item.generics,
2504 TraitOrImplItemRibKind);
2505 this.with_type_parameter_rib(type_parameters, |this| {
2506 use self::ResolutionError::*;
2507 match impl_item.node {
2508 ImplItemKind::Const(..) => {
2509 // If this is a trait impl, ensure the const
2511 this.check_trait_item(impl_item.ident,
2514 |n, s| ConstNotMemberOfTrait(n, s));
2515 this.with_constant_rib(|this|
2516 visit::walk_impl_item(this, impl_item)
2519 ImplItemKind::Method(..) => {
2520 // If this is a trait impl, ensure the method
2522 this.check_trait_item(impl_item.ident,
2525 |n, s| MethodNotMemberOfTrait(n, s));
2527 visit::walk_impl_item(this, impl_item);
2529 ImplItemKind::Type(ref ty) => {
2530 // If this is a trait impl, ensure the type
2532 this.check_trait_item(impl_item.ident,
2535 |n, s| TypeNotMemberOfTrait(n, s));
2539 ImplItemKind::Existential(ref bounds) => {
2540 // If this is a trait impl, ensure the type
2542 this.check_trait_item(impl_item.ident,
2545 |n, s| TypeNotMemberOfTrait(n, s));
2547 for bound in bounds {
2548 this.visit_param_bound(bound);
2551 ImplItemKind::Macro(_) =>
2552 panic!("unexpanded macro in resolve!"),
2563 fn check_trait_item<F>(&mut self, ident: Ident, ns: Namespace, span: Span, err: F)
2564 where F: FnOnce(Name, &str) -> ResolutionError
2566 // If there is a TraitRef in scope for an impl, then the method must be in the
2568 if let Some((module, _)) = self.current_trait_ref {
2569 if self.resolve_ident_in_module(
2570 ModuleOrUniformRoot::Module(module),
2576 let path = &self.current_trait_ref.as_ref().unwrap().1.path;
2577 resolve_error(self, span, err(ident.name, &path_names_to_string(path)));
2582 fn resolve_local(&mut self, local: &Local) {
2583 // Resolve the type.
2584 walk_list!(self, visit_ty, &local.ty);
2586 // Resolve the initializer.
2587 walk_list!(self, visit_expr, &local.init);
2589 // Resolve the pattern.
2590 self.resolve_pattern(&local.pat, PatternSource::Let, &mut FxHashMap());
2593 // build a map from pattern identifiers to binding-info's.
2594 // this is done hygienically. This could arise for a macro
2595 // that expands into an or-pattern where one 'x' was from the
2596 // user and one 'x' came from the macro.
2597 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2598 let mut binding_map = FxHashMap();
2600 pat.walk(&mut |pat| {
2601 if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node {
2602 if sub_pat.is_some() || match self.def_map.get(&pat.id).map(|res| res.base_def()) {
2603 Some(Def::Local(..)) => true,
2606 let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode };
2607 binding_map.insert(ident, binding_info);
2616 // check that all of the arms in an or-pattern have exactly the
2617 // same set of bindings, with the same binding modes for each.
2618 fn check_consistent_bindings(&mut self, pats: &[P<Pat>]) {
2619 if pats.is_empty() {
2623 let mut missing_vars = FxHashMap();
2624 let mut inconsistent_vars = FxHashMap();
2625 for (i, p) in pats.iter().enumerate() {
2626 let map_i = self.binding_mode_map(&p);
2628 for (j, q) in pats.iter().enumerate() {
2633 let map_j = self.binding_mode_map(&q);
2634 for (&key, &binding_i) in &map_i {
2635 if map_j.len() == 0 { // Account for missing bindings when
2636 let binding_error = missing_vars // map_j has none.
2638 .or_insert(BindingError {
2640 origin: BTreeSet::new(),
2641 target: BTreeSet::new(),
2643 binding_error.origin.insert(binding_i.span);
2644 binding_error.target.insert(q.span);
2646 for (&key_j, &binding_j) in &map_j {
2647 match map_i.get(&key_j) {
2648 None => { // missing binding
2649 let binding_error = missing_vars
2651 .or_insert(BindingError {
2653 origin: BTreeSet::new(),
2654 target: BTreeSet::new(),
2656 binding_error.origin.insert(binding_j.span);
2657 binding_error.target.insert(p.span);
2659 Some(binding_i) => { // check consistent binding
2660 if binding_i.binding_mode != binding_j.binding_mode {
2663 .or_insert((binding_j.span, binding_i.span));
2671 let mut missing_vars = missing_vars.iter().collect::<Vec<_>>();
2672 missing_vars.sort();
2673 for (_, v) in missing_vars {
2675 *v.origin.iter().next().unwrap(),
2676 ResolutionError::VariableNotBoundInPattern(v));
2678 let mut inconsistent_vars = inconsistent_vars.iter().collect::<Vec<_>>();
2679 inconsistent_vars.sort();
2680 for (name, v) in inconsistent_vars {
2681 resolve_error(self, v.0, ResolutionError::VariableBoundWithDifferentMode(*name, v.1));
2685 fn resolve_arm(&mut self, arm: &Arm) {
2686 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2688 let mut bindings_list = FxHashMap();
2689 for pattern in &arm.pats {
2690 self.resolve_pattern(&pattern, PatternSource::Match, &mut bindings_list);
2693 // This has to happen *after* we determine which pat_idents are variants
2694 self.check_consistent_bindings(&arm.pats);
2696 walk_list!(self, visit_expr, &arm.guard);
2697 self.visit_expr(&arm.body);
2699 self.ribs[ValueNS].pop();
2702 fn resolve_block(&mut self, block: &Block) {
2703 debug!("(resolving block) entering block");
2704 // Move down in the graph, if there's an anonymous module rooted here.
2705 let orig_module = self.current_module;
2706 let anonymous_module = self.block_map.get(&block.id).cloned(); // clones a reference
2708 let mut num_macro_definition_ribs = 0;
2709 if let Some(anonymous_module) = anonymous_module {
2710 debug!("(resolving block) found anonymous module, moving down");
2711 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2712 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2713 self.current_module = anonymous_module;
2714 self.finalize_current_module_macro_resolutions();
2716 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2719 // Descend into the block.
2720 for stmt in &block.stmts {
2721 if let ast::StmtKind::Item(ref item) = stmt.node {
2722 if let ast::ItemKind::MacroDef(..) = item.node {
2723 num_macro_definition_ribs += 1;
2724 let def = self.definitions.local_def_id(item.id);
2725 self.ribs[ValueNS].push(Rib::new(MacroDefinition(def)));
2726 self.label_ribs.push(Rib::new(MacroDefinition(def)));
2730 self.visit_stmt(stmt);
2734 self.current_module = orig_module;
2735 for _ in 0 .. num_macro_definition_ribs {
2736 self.ribs[ValueNS].pop();
2737 self.label_ribs.pop();
2739 self.ribs[ValueNS].pop();
2740 if anonymous_module.is_some() {
2741 self.ribs[TypeNS].pop();
2743 debug!("(resolving block) leaving block");
2746 fn fresh_binding(&mut self,
2749 outer_pat_id: NodeId,
2750 pat_src: PatternSource,
2751 bindings: &mut FxHashMap<Ident, NodeId>)
2753 // Add the binding to the local ribs, if it
2754 // doesn't already exist in the bindings map. (We
2755 // must not add it if it's in the bindings map
2756 // because that breaks the assumptions later
2757 // passes make about or-patterns.)
2758 let ident = ident.modern_and_legacy();
2759 let mut def = Def::Local(pat_id);
2760 match bindings.get(&ident).cloned() {
2761 Some(id) if id == outer_pat_id => {
2762 // `Variant(a, a)`, error
2766 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2770 Some(..) if pat_src == PatternSource::FnParam => {
2771 // `fn f(a: u8, a: u8)`, error
2775 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2779 Some(..) if pat_src == PatternSource::Match ||
2780 pat_src == PatternSource::IfLet ||
2781 pat_src == PatternSource::WhileLet => {
2782 // `Variant1(a) | Variant2(a)`, ok
2783 // Reuse definition from the first `a`.
2784 def = self.ribs[ValueNS].last_mut().unwrap().bindings[&ident];
2787 span_bug!(ident.span, "two bindings with the same name from \
2788 unexpected pattern source {:?}", pat_src);
2791 // A completely fresh binding, add to the lists if it's valid.
2792 if ident.name != keywords::Invalid.name() {
2793 bindings.insert(ident, outer_pat_id);
2794 self.ribs[ValueNS].last_mut().unwrap().bindings.insert(ident, def);
2799 PathResolution::new(def)
2802 fn resolve_pattern(&mut self,
2804 pat_src: PatternSource,
2805 // Maps idents to the node ID for the
2806 // outermost pattern that binds them.
2807 bindings: &mut FxHashMap<Ident, NodeId>) {
2808 // Visit all direct subpatterns of this pattern.
2809 let outer_pat_id = pat.id;
2810 pat.walk(&mut |pat| {
2812 PatKind::Ident(bmode, ident, ref opt_pat) => {
2813 // First try to resolve the identifier as some existing
2814 // entity, then fall back to a fresh binding.
2815 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS,
2817 .and_then(LexicalScopeBinding::item);
2818 let resolution = binding.map(NameBinding::def).and_then(|def| {
2819 let is_syntactic_ambiguity = opt_pat.is_none() &&
2820 bmode == BindingMode::ByValue(Mutability::Immutable);
2822 Def::StructCtor(_, CtorKind::Const) |
2823 Def::VariantCtor(_, CtorKind::Const) |
2824 Def::Const(..) if is_syntactic_ambiguity => {
2825 // Disambiguate in favor of a unit struct/variant
2826 // or constant pattern.
2827 self.record_use(ident, ValueNS, binding.unwrap(), ident.span);
2828 Some(PathResolution::new(def))
2830 Def::StructCtor(..) | Def::VariantCtor(..) |
2831 Def::Const(..) | Def::Static(..) => {
2832 // This is unambiguously a fresh binding, either syntactically
2833 // (e.g. `IDENT @ PAT` or `ref IDENT`) or because `IDENT` resolves
2834 // to something unusable as a pattern (e.g. constructor function),
2835 // but we still conservatively report an error, see
2836 // issues/33118#issuecomment-233962221 for one reason why.
2840 ResolutionError::BindingShadowsSomethingUnacceptable(
2841 pat_src.descr(), ident.name, binding.unwrap())
2845 Def::Fn(..) | Def::Err => {
2846 // These entities are explicitly allowed
2847 // to be shadowed by fresh bindings.
2851 span_bug!(ident.span, "unexpected definition for an \
2852 identifier in pattern: {:?}", def);
2855 }).unwrap_or_else(|| {
2856 self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings)
2859 self.record_def(pat.id, resolution);
2862 PatKind::TupleStruct(ref path, ..) => {
2863 self.smart_resolve_path(pat.id, None, path, PathSource::TupleStruct);
2866 PatKind::Path(ref qself, ref path) => {
2867 self.smart_resolve_path(pat.id, qself.as_ref(), path, PathSource::Pat);
2870 PatKind::Struct(ref path, ..) => {
2871 self.smart_resolve_path(pat.id, None, path, PathSource::Struct);
2879 visit::walk_pat(self, pat);
2882 // High-level and context dependent path resolution routine.
2883 // Resolves the path and records the resolution into definition map.
2884 // If resolution fails tries several techniques to find likely
2885 // resolution candidates, suggest imports or other help, and report
2886 // errors in user friendly way.
2887 fn smart_resolve_path(&mut self,
2889 qself: Option<&QSelf>,
2893 self.smart_resolve_path_with_crate_lint(id, qself, path, source, CrateLint::SimplePath(id))
2896 /// A variant of `smart_resolve_path` where you also specify extra
2897 /// information about where the path came from; this extra info is
2898 /// sometimes needed for the lint that recommends rewriting
2899 /// absolute paths to `crate`, so that it knows how to frame the
2900 /// suggestion. If you are just resolving a path like `foo::bar`
2901 /// that appears...somewhere, though, then you just want
2902 /// `CrateLint::SimplePath`, which is what `smart_resolve_path`
2903 /// already provides.
2904 fn smart_resolve_path_with_crate_lint(
2907 qself: Option<&QSelf>,
2910 crate_lint: CrateLint
2911 ) -> PathResolution {
2912 let segments = &path.segments.iter()
2913 .map(|seg| seg.ident)
2914 .collect::<Vec<_>>();
2915 self.smart_resolve_path_fragment(id, qself, segments, path.span, source, crate_lint)
2918 fn smart_resolve_path_fragment(&mut self,
2920 qself: Option<&QSelf>,
2924 crate_lint: CrateLint)
2926 let ident_span = path.last().map_or(span, |ident| ident.span);
2927 let ns = source.namespace();
2928 let is_expected = &|def| source.is_expected(def);
2929 let is_enum_variant = &|def| if let Def::Variant(..) = def { true } else { false };
2931 // Base error is amended with one short label and possibly some longer helps/notes.
2932 let report_errors = |this: &mut Self, def: Option<Def>| {
2933 // Make the base error.
2934 let expected = source.descr_expected();
2935 let path_str = names_to_string(path);
2936 let code = source.error_code(def.is_some());
2937 let (base_msg, fallback_label, base_span) = if let Some(def) = def {
2938 (format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str),
2939 format!("not a {}", expected),
2942 let item_str = path[path.len() - 1];
2943 let item_span = path[path.len() - 1].span;
2944 let (mod_prefix, mod_str) = if path.len() == 1 {
2945 (String::new(), "this scope".to_string())
2946 } else if path.len() == 2 && path[0].name == keywords::CrateRoot.name() {
2947 (String::new(), "the crate root".to_string())
2949 let mod_path = &path[..path.len() - 1];
2950 let mod_prefix = match this.resolve_path(None, mod_path, Some(TypeNS),
2951 false, span, CrateLint::No) {
2952 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
2955 }.map_or(String::new(), |def| format!("{} ", def.kind_name()));
2956 (mod_prefix, format!("`{}`", names_to_string(mod_path)))
2958 (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str),
2959 format!("not found in {}", mod_str),
2962 let code = DiagnosticId::Error(code.into());
2963 let mut err = this.session.struct_span_err_with_code(base_span, &base_msg, code);
2965 // Emit special messages for unresolved `Self` and `self`.
2966 if is_self_type(path, ns) {
2967 __diagnostic_used!(E0411);
2968 err.code(DiagnosticId::Error("E0411".into()));
2969 let available_in = if this.session.features_untracked().self_in_typedefs {
2970 "impls, traits, and type definitions"
2974 err.span_label(span, format!("`Self` is only available in {}", available_in));
2975 return (err, Vec::new());
2977 if is_self_value(path, ns) {
2978 __diagnostic_used!(E0424);
2979 err.code(DiagnosticId::Error("E0424".into()));
2980 err.span_label(span, format!("`self` value is only available in \
2981 methods with `self` parameter"));
2982 return (err, Vec::new());
2985 // Try to lookup the name in more relaxed fashion for better error reporting.
2986 let ident = *path.last().unwrap();
2987 let candidates = this.lookup_import_candidates(ident.name, ns, is_expected);
2988 if candidates.is_empty() && is_expected(Def::Enum(DefId::local(CRATE_DEF_INDEX))) {
2989 let enum_candidates =
2990 this.lookup_import_candidates(ident.name, ns, is_enum_variant);
2991 let mut enum_candidates = enum_candidates.iter()
2992 .map(|suggestion| import_candidate_to_paths(&suggestion)).collect::<Vec<_>>();
2993 enum_candidates.sort();
2994 for (sp, variant_path, enum_path) in enum_candidates {
2996 let msg = format!("there is an enum variant `{}`, \
3002 err.span_suggestion(span, "you can try using the variant's enum",
3007 if path.len() == 1 && this.self_type_is_available(span) {
3008 if let Some(candidate) = this.lookup_assoc_candidate(ident, ns, is_expected) {
3009 let self_is_available = this.self_value_is_available(path[0].span, span);
3011 AssocSuggestion::Field => {
3012 err.span_suggestion(span, "try",
3013 format!("self.{}", path_str));
3014 if !self_is_available {
3015 err.span_label(span, format!("`self` value is only available in \
3016 methods with `self` parameter"));
3019 AssocSuggestion::MethodWithSelf if self_is_available => {
3020 err.span_suggestion(span, "try",
3021 format!("self.{}", path_str));
3023 AssocSuggestion::MethodWithSelf | AssocSuggestion::AssocItem => {
3024 err.span_suggestion(span, "try",
3025 format!("Self::{}", path_str));
3028 return (err, candidates);
3032 let mut levenshtein_worked = false;
3035 if let Some(candidate) = this.lookup_typo_candidate(path, ns, is_expected, span) {
3036 err.span_label(ident_span, format!("did you mean `{}`?", candidate));
3037 levenshtein_worked = true;
3040 // Try context dependent help if relaxed lookup didn't work.
3041 if let Some(def) = def {
3042 match (def, source) {
3043 (Def::Macro(..), _) => {
3044 err.span_label(span, format!("did you mean `{}!(...)`?", path_str));
3045 return (err, candidates);
3047 (Def::TyAlias(..), PathSource::Trait(_)) => {
3048 err.span_label(span, "type aliases cannot be used for traits");
3049 return (err, candidates);
3051 (Def::Mod(..), PathSource::Expr(Some(parent))) => match parent.node {
3052 ExprKind::Field(_, ident) => {
3053 err.span_label(parent.span, format!("did you mean `{}::{}`?",
3055 return (err, candidates);
3057 ExprKind::MethodCall(ref segment, ..) => {
3058 err.span_label(parent.span, format!("did you mean `{}::{}(...)`?",
3059 path_str, segment.ident));
3060 return (err, candidates);
3064 (Def::Enum(..), PathSource::TupleStruct)
3065 | (Def::Enum(..), PathSource::Expr(..)) => {
3066 if let Some(variants) = this.collect_enum_variants(def) {
3067 err.note(&format!("did you mean to use one \
3068 of the following variants?\n{}",
3070 .map(|suggestion| path_names_to_string(suggestion))
3071 .map(|suggestion| format!("- `{}`", suggestion))
3072 .collect::<Vec<_>>()
3076 err.note("did you mean to use one of the enum's variants?");
3078 return (err, candidates);
3080 (Def::Struct(def_id), _) if ns == ValueNS => {
3081 if let Some((ctor_def, ctor_vis))
3082 = this.struct_constructors.get(&def_id).cloned() {
3083 let accessible_ctor = this.is_accessible(ctor_vis);
3084 if is_expected(ctor_def) && !accessible_ctor {
3085 err.span_label(span, format!("constructor is not visible \
3086 here due to private fields"));
3089 // HACK(estebank): find a better way to figure out that this was a
3090 // parser issue where a struct literal is being used on an expression
3091 // where a brace being opened means a block is being started. Look
3092 // ahead for the next text to see if `span` is followed by a `{`.
3093 let cm = this.session.source_map();
3096 sp = cm.next_point(sp);
3097 match cm.span_to_snippet(sp) {
3098 Ok(ref snippet) => {
3099 if snippet.chars().any(|c| { !c.is_whitespace() }) {
3106 let followed_by_brace = match cm.span_to_snippet(sp) {
3107 Ok(ref snippet) if snippet == "{" => true,
3110 if let (PathSource::Expr(None), true) = (source, followed_by_brace) {
3113 format!("did you mean `({} {{ /* fields */ }})`?", path_str),
3118 format!("did you mean `{} {{ /* fields */ }}`?", path_str),
3122 return (err, candidates);
3124 (Def::Union(..), _) |
3125 (Def::Variant(..), _) |
3126 (Def::VariantCtor(_, CtorKind::Fictive), _) if ns == ValueNS => {
3127 err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?",
3129 return (err, candidates);
3131 (Def::SelfTy(..), _) if ns == ValueNS => {
3132 err.span_label(span, fallback_label);
3133 err.note("can't use `Self` as a constructor, you must use the \
3134 implemented struct");
3135 return (err, candidates);
3137 (Def::TyAlias(_), _) | (Def::AssociatedTy(..), _) if ns == ValueNS => {
3138 err.note("can't use a type alias as a constructor");
3139 return (err, candidates);
3146 if !levenshtein_worked {
3147 err.span_label(base_span, fallback_label);
3148 this.type_ascription_suggestion(&mut err, base_span);
3152 let report_errors = |this: &mut Self, def: Option<Def>| {
3153 let (err, candidates) = report_errors(this, def);
3154 let def_id = this.current_module.normal_ancestor_id;
3155 let node_id = this.definitions.as_local_node_id(def_id).unwrap();
3156 let better = def.is_some();
3157 this.use_injections.push(UseError { err, candidates, node_id, better });
3158 err_path_resolution()
3161 let resolution = match self.resolve_qpath_anywhere(
3167 source.defer_to_typeck(),
3168 source.global_by_default(),
3171 Some(resolution) if resolution.unresolved_segments() == 0 => {
3172 if is_expected(resolution.base_def()) || resolution.base_def() == Def::Err {
3175 // Add a temporary hack to smooth the transition to new struct ctor
3176 // visibility rules. See #38932 for more details.
3178 if let Def::Struct(def_id) = resolution.base_def() {
3179 if let Some((ctor_def, ctor_vis))
3180 = self.struct_constructors.get(&def_id).cloned() {
3181 if is_expected(ctor_def) && self.is_accessible(ctor_vis) {
3182 let lint = lint::builtin::LEGACY_CONSTRUCTOR_VISIBILITY;
3183 self.session.buffer_lint(lint, id, span,
3184 "private struct constructors are not usable through \
3185 re-exports in outer modules",
3187 res = Some(PathResolution::new(ctor_def));
3192 res.unwrap_or_else(|| report_errors(self, Some(resolution.base_def())))
3195 Some(resolution) if source.defer_to_typeck() => {
3196 // Not fully resolved associated item `T::A::B` or `<T as Tr>::A::B`
3197 // or `<T>::A::B`. If `B` should be resolved in value namespace then
3198 // it needs to be added to the trait map.
3200 let item_name = *path.last().unwrap();
3201 let traits = self.get_traits_containing_item(item_name, ns);
3202 self.trait_map.insert(id, traits);
3206 _ => report_errors(self, None)
3209 if let PathSource::TraitItem(..) = source {} else {
3210 // Avoid recording definition of `A::B` in `<T as A>::B::C`.
3211 self.record_def(id, resolution);
3216 fn type_ascription_suggestion(&self,
3217 err: &mut DiagnosticBuilder,
3219 debug!("type_ascription_suggetion {:?}", base_span);
3220 let cm = self.session.source_map();
3221 debug!("self.current_type_ascription {:?}", self.current_type_ascription);
3222 if let Some(sp) = self.current_type_ascription.last() {
3224 loop { // try to find the `:`, bail on first non-':'/non-whitespace
3225 sp = cm.next_point(sp);
3226 if let Ok(snippet) = cm.span_to_snippet(sp.to(cm.next_point(sp))) {
3227 debug!("snippet {:?}", snippet);
3228 let line_sp = cm.lookup_char_pos(sp.hi()).line;
3229 let line_base_sp = cm.lookup_char_pos(base_span.lo()).line;
3230 debug!("{:?} {:?}", line_sp, line_base_sp);
3232 err.span_label(base_span,
3233 "expecting a type here because of type ascription");
3234 if line_sp != line_base_sp {
3235 err.span_suggestion_short(sp,
3236 "did you mean to use `;` here instead?",
3240 } else if snippet.trim().len() != 0 {
3241 debug!("tried to find type ascription `:` token, couldn't find it");
3251 fn self_type_is_available(&mut self, span: Span) -> bool {
3252 let binding = self.resolve_ident_in_lexical_scope(keywords::SelfType.ident(),
3253 TypeNS, None, span);
3254 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
3257 fn self_value_is_available(&mut self, self_span: Span, path_span: Span) -> bool {
3258 let ident = Ident::new(keywords::SelfValue.name(), self_span);
3259 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, None, path_span);
3260 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
3263 // Resolve in alternative namespaces if resolution in the primary namespace fails.
3264 fn resolve_qpath_anywhere(&mut self,
3266 qself: Option<&QSelf>,
3268 primary_ns: Namespace,
3270 defer_to_typeck: bool,
3271 global_by_default: bool,
3272 crate_lint: CrateLint)
3273 -> Option<PathResolution> {
3274 let mut fin_res = None;
3275 // FIXME: can't resolve paths in macro namespace yet, macros are
3276 // processed by the little special hack below.
3277 for (i, ns) in [primary_ns, TypeNS, ValueNS, /*MacroNS*/].iter().cloned().enumerate() {
3278 if i == 0 || ns != primary_ns {
3279 match self.resolve_qpath(id, qself, path, ns, span, global_by_default, crate_lint) {
3280 // If defer_to_typeck, then resolution > no resolution,
3281 // otherwise full resolution > partial resolution > no resolution.
3282 Some(res) if res.unresolved_segments() == 0 || defer_to_typeck =>
3284 res => if fin_res.is_none() { fin_res = res },
3288 let is_global = self.macro_prelude.get(&path[0].name).cloned()
3289 .map(|binding| binding.get_macro(self).kind() == MacroKind::Bang).unwrap_or(false);
3290 if primary_ns != MacroNS && (is_global ||
3291 self.macro_names.contains(&path[0].modern())) {
3292 // Return some dummy definition, it's enough for error reporting.
3294 PathResolution::new(Def::Macro(DefId::local(CRATE_DEF_INDEX), MacroKind::Bang))
3300 /// Handles paths that may refer to associated items.
3301 fn resolve_qpath(&mut self,
3303 qself: Option<&QSelf>,
3307 global_by_default: bool,
3308 crate_lint: CrateLint)
3309 -> Option<PathResolution> {
3311 "resolve_qpath(id={:?}, qself={:?}, path={:?}, \
3312 ns={:?}, span={:?}, global_by_default={:?})",
3321 if let Some(qself) = qself {
3322 if qself.position == 0 {
3323 // This is a case like `<T>::B`, where there is no
3324 // trait to resolve. In that case, we leave the `B`
3325 // segment to be resolved by type-check.
3326 return Some(PathResolution::with_unresolved_segments(
3327 Def::Mod(DefId::local(CRATE_DEF_INDEX)), path.len()
3331 // Make sure `A::B` in `<T as A::B>::C` is a trait item.
3333 // Currently, `path` names the full item (`A::B::C`, in
3334 // our example). so we extract the prefix of that that is
3335 // the trait (the slice upto and including
3336 // `qself.position`). And then we recursively resolve that,
3337 // but with `qself` set to `None`.
3339 // However, setting `qself` to none (but not changing the
3340 // span) loses the information about where this path
3341 // *actually* appears, so for the purposes of the crate
3342 // lint we pass along information that this is the trait
3343 // name from a fully qualified path, and this also
3344 // contains the full span (the `CrateLint::QPathTrait`).
3345 let ns = if qself.position + 1 == path.len() { ns } else { TypeNS };
3346 let res = self.smart_resolve_path_fragment(
3349 &path[..qself.position + 1],
3351 PathSource::TraitItem(ns),
3352 CrateLint::QPathTrait {
3354 qpath_span: qself.path_span,
3358 // The remaining segments (the `C` in our example) will
3359 // have to be resolved by type-check, since that requires doing
3360 // trait resolution.
3361 return Some(PathResolution::with_unresolved_segments(
3362 res.base_def(), res.unresolved_segments() + path.len() - qself.position - 1
3366 let result = match self.resolve_path(
3374 PathResult::NonModule(path_res) => path_res,
3375 PathResult::Module(ModuleOrUniformRoot::Module(module)) if !module.is_normal() => {
3376 PathResolution::new(module.def().unwrap())
3378 // In `a(::assoc_item)*` `a` cannot be a module. If `a` does resolve to a module we
3379 // don't report an error right away, but try to fallback to a primitive type.
3380 // So, we are still able to successfully resolve something like
3382 // use std::u8; // bring module u8 in scope
3383 // fn f() -> u8 { // OK, resolves to primitive u8, not to std::u8
3384 // u8::max_value() // OK, resolves to associated function <u8>::max_value,
3385 // // not to non-existent std::u8::max_value
3388 // Such behavior is required for backward compatibility.
3389 // The same fallback is used when `a` resolves to nothing.
3390 PathResult::Module(ModuleOrUniformRoot::Module(_)) |
3391 PathResult::Failed(..)
3392 if (ns == TypeNS || path.len() > 1) &&
3393 self.primitive_type_table.primitive_types
3394 .contains_key(&path[0].name) => {
3395 let prim = self.primitive_type_table.primitive_types[&path[0].name];
3396 PathResolution::with_unresolved_segments(Def::PrimTy(prim), path.len() - 1)
3398 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
3399 PathResolution::new(module.def().unwrap()),
3400 PathResult::Failed(span, msg, false) => {
3401 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
3402 err_path_resolution()
3404 PathResult::Module(ModuleOrUniformRoot::UniformRoot(_)) |
3405 PathResult::Failed(..) => return None,
3406 PathResult::Indeterminate => bug!("indetermined path result in resolve_qpath"),
3409 if path.len() > 1 && !global_by_default && result.base_def() != Def::Err &&
3410 path[0].name != keywords::CrateRoot.name() &&
3411 path[0].name != keywords::DollarCrate.name() {
3412 let unqualified_result = {
3413 match self.resolve_path(
3415 &[*path.last().unwrap()],
3421 PathResult::NonModule(path_res) => path_res.base_def(),
3422 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
3423 module.def().unwrap(),
3424 _ => return Some(result),
3427 if result.base_def() == unqualified_result {
3428 let lint = lint::builtin::UNUSED_QUALIFICATIONS;
3429 self.session.buffer_lint(lint, id, span, "unnecessary qualification")
3438 base_module: Option<ModuleOrUniformRoot<'a>>,
3440 opt_ns: Option<Namespace>, // `None` indicates a module path
3443 crate_lint: CrateLint,
3444 ) -> PathResult<'a> {
3445 let mut module = base_module;
3446 let mut allow_super = true;
3447 let mut second_binding = None;
3450 "resolve_path(path={:?}, opt_ns={:?}, record_used={:?}, \
3451 path_span={:?}, crate_lint={:?})",
3459 for (i, &ident) in path.iter().enumerate() {
3460 debug!("resolve_path ident {} {:?}", i, ident);
3461 let is_last = i == path.len() - 1;
3462 let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
3463 let name = ident.name;
3465 allow_super &= ns == TypeNS &&
3466 (name == keywords::SelfValue.name() ||
3467 name == keywords::Super.name());
3470 if allow_super && name == keywords::Super.name() {
3471 let mut ctxt = ident.span.ctxt().modern();
3472 let self_module = match i {
3473 0 => Some(self.resolve_self(&mut ctxt, self.current_module)),
3475 Some(ModuleOrUniformRoot::Module(module)) => Some(module),
3479 if let Some(self_module) = self_module {
3480 if let Some(parent) = self_module.parent {
3481 module = Some(ModuleOrUniformRoot::Module(
3482 self.resolve_self(&mut ctxt, parent)));
3486 let msg = "There are too many initial `super`s.".to_string();
3487 return PathResult::Failed(ident.span, msg, false);
3490 if name == keywords::SelfValue.name() {
3491 let mut ctxt = ident.span.ctxt().modern();
3492 module = Some(ModuleOrUniformRoot::Module(
3493 self.resolve_self(&mut ctxt, self.current_module)));
3496 if name == keywords::Extern.name() ||
3497 name == keywords::CrateRoot.name() &&
3498 self.session.features_untracked().extern_absolute_paths &&
3499 self.session.rust_2018() {
3500 module = Some(ModuleOrUniformRoot::UniformRoot(name));
3503 if name == keywords::CrateRoot.name() ||
3504 name == keywords::Crate.name() ||
3505 name == keywords::DollarCrate.name() {
3506 // `::a::b`, `crate::a::b` or `$crate::a::b`
3507 module = Some(ModuleOrUniformRoot::Module(
3508 self.resolve_crate_root(ident)));
3514 // Report special messages for path segment keywords in wrong positions.
3515 if ident.is_path_segment_keyword() && i != 0 {
3516 let name_str = if name == keywords::CrateRoot.name() {
3517 "crate root".to_string()
3519 format!("`{}`", name)
3521 let msg = if i == 1 && path[0].name == keywords::CrateRoot.name() {
3522 format!("global paths cannot start with {}", name_str)
3524 format!("{} in paths can only be used in start position", name_str)
3526 return PathResult::Failed(ident.span, msg, false);
3529 let binding = if let Some(module) = module {
3530 self.resolve_ident_in_module(module, ident, ns, record_used, path_span)
3531 } else if opt_ns == Some(MacroNS) {
3532 assert!(ns == TypeNS);
3533 self.resolve_lexical_macro_path_segment(ident, ns, record_used, record_used,
3534 false, path_span).map(|(b, _)| b)
3536 let record_used_id =
3537 if record_used { crate_lint.node_id().or(Some(CRATE_NODE_ID)) } else { None };
3538 match self.resolve_ident_in_lexical_scope(ident, ns, record_used_id, path_span) {
3539 // we found a locally-imported or available item/module
3540 Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
3541 // we found a local variable or type param
3542 Some(LexicalScopeBinding::Def(def))
3543 if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) => {
3544 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3548 _ => Err(if record_used { Determined } else { Undetermined }),
3555 second_binding = Some(binding);
3557 let def = binding.def();
3558 let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(def);
3559 if let Some(next_module) = binding.module() {
3560 module = Some(ModuleOrUniformRoot::Module(next_module));
3561 } else if def == Def::ToolMod && i + 1 != path.len() {
3562 let def = Def::NonMacroAttr(NonMacroAttrKind::Tool);
3563 return PathResult::NonModule(PathResolution::new(def));
3564 } else if def == Def::Err {
3565 return PathResult::NonModule(err_path_resolution());
3566 } else if opt_ns.is_some() && (is_last || maybe_assoc) {
3567 self.lint_if_path_starts_with_module(
3573 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3574 def, path.len() - i - 1
3577 return PathResult::Failed(ident.span,
3578 format!("Not a module `{}`", ident),
3582 Err(Undetermined) => return PathResult::Indeterminate,
3583 Err(Determined) => {
3584 if let Some(ModuleOrUniformRoot::Module(module)) = module {
3585 if opt_ns.is_some() && !module.is_normal() {
3586 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3587 module.def().unwrap(), path.len() - i
3591 let module_def = match module {
3592 Some(ModuleOrUniformRoot::Module(module)) => module.def(),
3595 let msg = if module_def == self.graph_root.def() {
3596 let is_mod = |def| match def { Def::Mod(..) => true, _ => false };
3597 let mut candidates =
3598 self.lookup_import_candidates(name, TypeNS, is_mod);
3599 candidates.sort_by_cached_key(|c| {
3600 (c.path.segments.len(), c.path.to_string())
3602 if let Some(candidate) = candidates.get(0) {
3603 format!("Did you mean `{}`?", candidate.path)
3605 format!("Maybe a missing `extern crate {};`?", ident)
3608 format!("Use of undeclared type or module `{}`", ident)
3610 format!("Could not find `{}` in `{}`", ident, path[i - 1])
3612 return PathResult::Failed(ident.span, msg, is_last);
3617 self.lint_if_path_starts_with_module(crate_lint, path, path_span, second_binding);
3619 PathResult::Module(module.unwrap_or_else(|| {
3620 span_bug!(path_span, "resolve_path: empty(?) path {:?} has no module", path);
3625 fn lint_if_path_starts_with_module(
3627 crate_lint: CrateLint,
3630 second_binding: Option<&NameBinding>,
3632 // In the 2018 edition this lint is a hard error, so nothing to do
3633 if self.session.rust_2018() {
3637 // In the 2015 edition there's no use in emitting lints unless the
3638 // crate's already enabled the feature that we're going to suggest
3639 if !self.session.features_untracked().crate_in_paths {
3643 let (diag_id, diag_span) = match crate_lint {
3644 CrateLint::No => return,
3645 CrateLint::SimplePath(id) => (id, path_span),
3646 CrateLint::UsePath { root_id, root_span } => (root_id, root_span),
3647 CrateLint::QPathTrait { qpath_id, qpath_span } => (qpath_id, qpath_span),
3650 let first_name = match path.get(0) {
3651 Some(ident) => ident.name,
3655 // We're only interested in `use` paths which should start with
3656 // `{{root}}` or `extern` currently.
3657 if first_name != keywords::Extern.name() && first_name != keywords::CrateRoot.name() {
3662 // If this import looks like `crate::...` it's already good
3663 Some(ident) if ident.name == keywords::Crate.name() => return,
3664 // Otherwise go below to see if it's an extern crate
3666 // If the path has length one (and it's `CrateRoot` most likely)
3667 // then we don't know whether we're gonna be importing a crate or an
3668 // item in our crate. Defer this lint to elsewhere
3672 // If the first element of our path was actually resolved to an
3673 // `ExternCrate` (also used for `crate::...`) then no need to issue a
3674 // warning, this looks all good!
3675 if let Some(binding) = second_binding {
3676 if let NameBindingKind::Import { directive: d, .. } = binding.kind {
3677 // Careful: we still want to rewrite paths from
3678 // renamed extern crates.
3679 if let ImportDirectiveSubclass::ExternCrate(None) = d.subclass {
3685 let diag = lint::builtin::BuiltinLintDiagnostics
3686 ::AbsPathWithModule(diag_span);
3687 self.session.buffer_lint_with_diagnostic(
3688 lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
3690 "absolute paths must start with `self`, `super`, \
3691 `crate`, or an external crate name in the 2018 edition",
3695 // Resolve a local definition, potentially adjusting for closures.
3696 fn adjust_local_def(&mut self,
3701 span: Span) -> Def {
3702 let ribs = &self.ribs[ns][rib_index + 1..];
3704 // An invalid forward use of a type parameter from a previous default.
3705 if let ForwardTyParamBanRibKind = self.ribs[ns][rib_index].kind {
3707 resolve_error(self, span, ResolutionError::ForwardDeclaredTyParam);
3709 assert_eq!(def, Def::Err);
3715 span_bug!(span, "unexpected {:?} in bindings", def)
3717 Def::Local(node_id) => {
3720 NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) |
3721 ForwardTyParamBanRibKind => {
3722 // Nothing to do. Continue.
3724 ClosureRibKind(function_id) => {
3727 let seen = self.freevars_seen
3730 if let Some(&index) = seen.get(&node_id) {
3731 def = Def::Upvar(node_id, index, function_id);
3734 let vec = self.freevars
3737 let depth = vec.len();
3738 def = Def::Upvar(node_id, depth, function_id);
3745 seen.insert(node_id, depth);
3748 ItemRibKind | TraitOrImplItemRibKind => {
3749 // This was an attempt to access an upvar inside a
3750 // named function item. This is not allowed, so we
3753 resolve_error(self, span,
3754 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
3758 ConstantItemRibKind => {
3759 // Still doesn't deal with upvars
3761 resolve_error(self, span,
3762 ResolutionError::AttemptToUseNonConstantValueInConstant);
3769 Def::TyParam(..) | Def::SelfTy(..) => {
3772 NormalRibKind | TraitOrImplItemRibKind | ClosureRibKind(..) |
3773 ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind |
3774 ConstantItemRibKind => {
3775 // Nothing to do. Continue.
3778 // This was an attempt to use a type parameter outside
3781 resolve_error(self, span,
3782 ResolutionError::TypeParametersFromOuterFunction(def));
3794 fn lookup_assoc_candidate<FilterFn>(&mut self,
3797 filter_fn: FilterFn)
3798 -> Option<AssocSuggestion>
3799 where FilterFn: Fn(Def) -> bool
3801 fn extract_node_id(t: &Ty) -> Option<NodeId> {
3803 TyKind::Path(None, _) => Some(t.id),
3804 TyKind::Rptr(_, ref mut_ty) => extract_node_id(&mut_ty.ty),
3805 // This doesn't handle the remaining `Ty` variants as they are not
3806 // that commonly the self_type, it might be interesting to provide
3807 // support for those in future.
3812 // Fields are generally expected in the same contexts as locals.
3813 if filter_fn(Def::Local(ast::DUMMY_NODE_ID)) {
3814 if let Some(node_id) = self.current_self_type.as_ref().and_then(extract_node_id) {
3815 // Look for a field with the same name in the current self_type.
3816 if let Some(resolution) = self.def_map.get(&node_id) {
3817 match resolution.base_def() {
3818 Def::Struct(did) | Def::Union(did)
3819 if resolution.unresolved_segments() == 0 => {
3820 if let Some(field_names) = self.field_names.get(&did) {
3821 if field_names.iter().any(|&field_name| ident.name == field_name) {
3822 return Some(AssocSuggestion::Field);
3832 // Look for associated items in the current trait.
3833 if let Some((module, _)) = self.current_trait_ref {
3834 if let Ok(binding) = self.resolve_ident_in_module(
3835 ModuleOrUniformRoot::Module(module),
3841 let def = binding.def();
3843 return Some(if self.has_self.contains(&def.def_id()) {
3844 AssocSuggestion::MethodWithSelf
3846 AssocSuggestion::AssocItem
3855 fn lookup_typo_candidate<FilterFn>(&mut self,
3858 filter_fn: FilterFn,
3861 where FilterFn: Fn(Def) -> bool
3863 let add_module_candidates = |module: Module, names: &mut Vec<Name>| {
3864 for (&(ident, _), resolution) in module.resolutions.borrow().iter() {
3865 if let Some(binding) = resolution.borrow().binding {
3866 if filter_fn(binding.def()) {
3867 names.push(ident.name);
3873 let mut names = Vec::new();
3874 if path.len() == 1 {
3875 // Search in lexical scope.
3876 // Walk backwards up the ribs in scope and collect candidates.
3877 for rib in self.ribs[ns].iter().rev() {
3878 // Locals and type parameters
3879 for (ident, def) in &rib.bindings {
3880 if filter_fn(*def) {
3881 names.push(ident.name);
3885 if let ModuleRibKind(module) = rib.kind {
3886 // Items from this module
3887 add_module_candidates(module, &mut names);
3889 if let ModuleKind::Block(..) = module.kind {
3890 // We can see through blocks
3892 // Items from the prelude
3893 if !module.no_implicit_prelude {
3894 names.extend(self.extern_prelude.iter().cloned());
3895 if let Some(prelude) = self.prelude {
3896 add_module_candidates(prelude, &mut names);
3903 // Add primitive types to the mix
3904 if filter_fn(Def::PrimTy(Bool)) {
3906 self.primitive_type_table.primitive_types.iter().map(|(name, _)| name)
3910 // Search in module.
3911 let mod_path = &path[..path.len() - 1];
3912 if let PathResult::Module(module) = self.resolve_path(None, mod_path, Some(TypeNS),
3913 false, span, CrateLint::No) {
3914 if let ModuleOrUniformRoot::Module(module) = module {
3915 add_module_candidates(module, &mut names);
3920 let name = path[path.len() - 1].name;
3921 // Make sure error reporting is deterministic.
3922 names.sort_by_cached_key(|name| name.as_str());
3923 match find_best_match_for_name(names.iter(), &name.as_str(), None) {
3924 Some(found) if found != name => Some(found),
3929 fn with_resolved_label<F>(&mut self, label: Option<Label>, id: NodeId, f: F)
3930 where F: FnOnce(&mut Resolver)
3932 if let Some(label) = label {
3933 self.unused_labels.insert(id, label.ident.span);
3934 let def = Def::Label(id);
3935 self.with_label_rib(|this| {
3936 let ident = label.ident.modern_and_legacy();
3937 this.label_ribs.last_mut().unwrap().bindings.insert(ident, def);
3945 fn resolve_labeled_block(&mut self, label: Option<Label>, id: NodeId, block: &Block) {
3946 self.with_resolved_label(label, id, |this| this.visit_block(block));
3949 fn resolve_expr(&mut self, expr: &Expr, parent: Option<&Expr>) {
3950 // First, record candidate traits for this expression if it could
3951 // result in the invocation of a method call.
3953 self.record_candidate_traits_for_expr_if_necessary(expr);
3955 // Next, resolve the node.
3957 ExprKind::Path(ref qself, ref path) => {
3958 self.smart_resolve_path(expr.id, qself.as_ref(), path, PathSource::Expr(parent));
3959 visit::walk_expr(self, expr);
3962 ExprKind::Struct(ref path, ..) => {
3963 self.smart_resolve_path(expr.id, None, path, PathSource::Struct);
3964 visit::walk_expr(self, expr);
3967 ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => {
3968 let def = self.search_label(label.ident, |rib, ident| {
3969 rib.bindings.get(&ident.modern_and_legacy()).cloned()
3973 // Search again for close matches...
3974 // Picks the first label that is "close enough", which is not necessarily
3975 // the closest match
3976 let close_match = self.search_label(label.ident, |rib, ident| {
3977 let names = rib.bindings.iter().map(|(id, _)| &id.name);
3978 find_best_match_for_name(names, &*ident.as_str(), None)
3980 self.record_def(expr.id, err_path_resolution());
3983 ResolutionError::UndeclaredLabel(&label.ident.as_str(),
3986 Some(Def::Label(id)) => {
3987 // Since this def is a label, it is never read.
3988 self.record_def(expr.id, PathResolution::new(Def::Label(id)));
3989 self.unused_labels.remove(&id);
3992 span_bug!(expr.span, "label wasn't mapped to a label def!");
3996 // visit `break` argument if any
3997 visit::walk_expr(self, expr);
4000 ExprKind::IfLet(ref pats, ref subexpression, ref if_block, ref optional_else) => {
4001 self.visit_expr(subexpression);
4003 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
4004 let mut bindings_list = FxHashMap();
4006 self.resolve_pattern(pat, PatternSource::IfLet, &mut bindings_list);
4008 // This has to happen *after* we determine which pat_idents are variants
4009 self.check_consistent_bindings(pats);
4010 self.visit_block(if_block);
4011 self.ribs[ValueNS].pop();
4013 optional_else.as_ref().map(|expr| self.visit_expr(expr));
4016 ExprKind::Loop(ref block, label) => self.resolve_labeled_block(label, expr.id, &block),
4018 ExprKind::While(ref subexpression, ref block, label) => {
4019 self.with_resolved_label(label, expr.id, |this| {
4020 this.visit_expr(subexpression);
4021 this.visit_block(block);
4025 ExprKind::WhileLet(ref pats, ref subexpression, ref block, label) => {
4026 self.with_resolved_label(label, expr.id, |this| {
4027 this.visit_expr(subexpression);
4028 this.ribs[ValueNS].push(Rib::new(NormalRibKind));
4029 let mut bindings_list = FxHashMap();
4031 this.resolve_pattern(pat, PatternSource::WhileLet, &mut bindings_list);
4033 // This has to happen *after* we determine which pat_idents are variants
4034 this.check_consistent_bindings(pats);
4035 this.visit_block(block);
4036 this.ribs[ValueNS].pop();
4040 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, label) => {
4041 self.visit_expr(subexpression);
4042 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
4043 self.resolve_pattern(pattern, PatternSource::For, &mut FxHashMap());
4045 self.resolve_labeled_block(label, expr.id, block);
4047 self.ribs[ValueNS].pop();
4050 ExprKind::Block(ref block, label) => self.resolve_labeled_block(label, block.id, block),
4052 // Equivalent to `visit::walk_expr` + passing some context to children.
4053 ExprKind::Field(ref subexpression, _) => {
4054 self.resolve_expr(subexpression, Some(expr));
4056 ExprKind::MethodCall(ref segment, ref arguments) => {
4057 let mut arguments = arguments.iter();
4058 self.resolve_expr(arguments.next().unwrap(), Some(expr));
4059 for argument in arguments {
4060 self.resolve_expr(argument, None);
4062 self.visit_path_segment(expr.span, segment);
4065 ExprKind::Call(ref callee, ref arguments) => {
4066 self.resolve_expr(callee, Some(expr));
4067 for argument in arguments {
4068 self.resolve_expr(argument, None);
4071 ExprKind::Type(ref type_expr, _) => {
4072 self.current_type_ascription.push(type_expr.span);
4073 visit::walk_expr(self, expr);
4074 self.current_type_ascription.pop();
4076 // Resolve the body of async exprs inside the async closure to which they desugar
4077 ExprKind::Async(_, async_closure_id, ref block) => {
4078 let rib_kind = ClosureRibKind(async_closure_id);
4079 self.ribs[ValueNS].push(Rib::new(rib_kind));
4080 self.label_ribs.push(Rib::new(rib_kind));
4081 self.visit_block(&block);
4082 self.label_ribs.pop();
4083 self.ribs[ValueNS].pop();
4085 // `async |x| ...` gets desugared to `|x| future_from_generator(|| ...)`, so we need to
4086 // resolve the arguments within the proper scopes so that usages of them inside the
4087 // closure are detected as upvars rather than normal closure arg usages.
4089 _, IsAsync::Async { closure_id: inner_closure_id, .. }, _,
4090 ref fn_decl, ref body, _span,
4092 let rib_kind = ClosureRibKind(expr.id);
4093 self.ribs[ValueNS].push(Rib::new(rib_kind));
4094 self.label_ribs.push(Rib::new(rib_kind));
4095 // Resolve arguments:
4096 let mut bindings_list = FxHashMap();
4097 for argument in &fn_decl.inputs {
4098 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
4099 self.visit_ty(&argument.ty);
4101 // No need to resolve return type-- the outer closure return type is
4102 // FunctionRetTy::Default
4104 // Now resolve the inner closure
4106 let rib_kind = ClosureRibKind(inner_closure_id);
4107 self.ribs[ValueNS].push(Rib::new(rib_kind));
4108 self.label_ribs.push(Rib::new(rib_kind));
4109 // No need to resolve arguments: the inner closure has none.
4110 // Resolve the return type:
4111 visit::walk_fn_ret_ty(self, &fn_decl.output);
4113 self.visit_expr(body);
4114 self.label_ribs.pop();
4115 self.ribs[ValueNS].pop();
4117 self.label_ribs.pop();
4118 self.ribs[ValueNS].pop();
4121 visit::walk_expr(self, expr);
4126 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
4128 ExprKind::Field(_, ident) => {
4129 // FIXME(#6890): Even though you can't treat a method like a
4130 // field, we need to add any trait methods we find that match
4131 // the field name so that we can do some nice error reporting
4132 // later on in typeck.
4133 let traits = self.get_traits_containing_item(ident, ValueNS);
4134 self.trait_map.insert(expr.id, traits);
4136 ExprKind::MethodCall(ref segment, ..) => {
4137 debug!("(recording candidate traits for expr) recording traits for {}",
4139 let traits = self.get_traits_containing_item(segment.ident, ValueNS);
4140 self.trait_map.insert(expr.id, traits);
4148 fn get_traits_containing_item(&mut self, mut ident: Ident, ns: Namespace)
4149 -> Vec<TraitCandidate> {
4150 debug!("(getting traits containing item) looking for '{}'", ident.name);
4152 let mut found_traits = Vec::new();
4153 // Look for the current trait.
4154 if let Some((module, _)) = self.current_trait_ref {
4155 if self.resolve_ident_in_module(
4156 ModuleOrUniformRoot::Module(module),
4162 let def_id = module.def_id().unwrap();
4163 found_traits.push(TraitCandidate { def_id: def_id, import_id: None });
4167 ident.span = ident.span.modern();
4168 let mut search_module = self.current_module;
4170 self.get_traits_in_module_containing_item(ident, ns, search_module, &mut found_traits);
4171 search_module = unwrap_or!(
4172 self.hygienic_lexical_parent(search_module, &mut ident.span), break
4176 if let Some(prelude) = self.prelude {
4177 if !search_module.no_implicit_prelude {
4178 self.get_traits_in_module_containing_item(ident, ns, prelude, &mut found_traits);
4185 fn get_traits_in_module_containing_item(&mut self,
4189 found_traits: &mut Vec<TraitCandidate>) {
4190 assert!(ns == TypeNS || ns == ValueNS);
4191 let mut traits = module.traits.borrow_mut();
4192 if traits.is_none() {
4193 let mut collected_traits = Vec::new();
4194 module.for_each_child(|name, ns, binding| {
4195 if ns != TypeNS { return }
4196 if let Def::Trait(_) = binding.def() {
4197 collected_traits.push((name, binding));
4200 *traits = Some(collected_traits.into_boxed_slice());
4203 for &(trait_name, binding) in traits.as_ref().unwrap().iter() {
4204 let module = binding.module().unwrap();
4205 let mut ident = ident;
4206 if ident.span.glob_adjust(module.expansion, binding.span.ctxt().modern()).is_none() {
4209 if self.resolve_ident_in_module_unadjusted(
4210 ModuleOrUniformRoot::Module(module),
4217 let import_id = match binding.kind {
4218 NameBindingKind::Import { directive, .. } => {
4219 self.maybe_unused_trait_imports.insert(directive.id);
4220 self.add_to_glob_map(directive.id, trait_name);
4225 let trait_def_id = module.def_id().unwrap();
4226 found_traits.push(TraitCandidate { def_id: trait_def_id, import_id: import_id });
4231 /// When name resolution fails, this method can be used to look up candidate
4232 /// entities with the expected name. It allows filtering them using the
4233 /// supplied predicate (which should be used to only accept the types of
4234 /// definitions expected e.g. traits). The lookup spans across all crates.
4236 /// NOTE: The method does not look into imports, but this is not a problem,
4237 /// since we report the definitions (thus, the de-aliased imports).
4238 fn lookup_import_candidates<FilterFn>(&mut self,
4240 namespace: Namespace,
4241 filter_fn: FilterFn)
4242 -> Vec<ImportSuggestion>
4243 where FilterFn: Fn(Def) -> bool
4245 let mut candidates = Vec::new();
4246 let mut worklist = Vec::new();
4247 let mut seen_modules = FxHashSet();
4248 worklist.push((self.graph_root, Vec::new(), false));
4250 while let Some((in_module,
4252 in_module_is_extern)) = worklist.pop() {
4253 self.populate_module_if_necessary(in_module);
4255 // We have to visit module children in deterministic order to avoid
4256 // instabilities in reported imports (#43552).
4257 in_module.for_each_child_stable(|ident, ns, name_binding| {
4258 // avoid imports entirely
4259 if name_binding.is_import() && !name_binding.is_extern_crate() { return; }
4260 // avoid non-importable candidates as well
4261 if !name_binding.is_importable() { return; }
4263 // collect results based on the filter function
4264 if ident.name == lookup_name && ns == namespace {
4265 if filter_fn(name_binding.def()) {
4267 let mut segms = if self.session.rust_2018() && !in_module_is_extern {
4268 // crate-local absolute paths start with `crate::` in edition 2018
4269 // FIXME: may also be stabilized for Rust 2015 (Issues #45477, #44660)
4270 let mut full_segms = vec![
4271 ast::PathSegment::from_ident(keywords::Crate.ident())
4273 full_segms.extend(path_segments.clone());
4276 path_segments.clone()
4279 segms.push(ast::PathSegment::from_ident(ident));
4281 span: name_binding.span,
4284 // the entity is accessible in the following cases:
4285 // 1. if it's defined in the same crate, it's always
4286 // accessible (since private entities can be made public)
4287 // 2. if it's defined in another crate, it's accessible
4288 // only if both the module is public and the entity is
4289 // declared as public (due to pruning, we don't explore
4290 // outside crate private modules => no need to check this)
4291 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
4292 candidates.push(ImportSuggestion { path: path });
4297 // collect submodules to explore
4298 if let Some(module) = name_binding.module() {
4300 let mut path_segments = path_segments.clone();
4301 path_segments.push(ast::PathSegment::from_ident(ident));
4303 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
4304 // add the module to the lookup
4305 let is_extern = in_module_is_extern || name_binding.is_extern_crate();
4306 if seen_modules.insert(module.def_id().unwrap()) {
4307 worklist.push((module, path_segments, is_extern));
4317 fn find_module(&mut self,
4319 -> Option<(Module<'a>, ImportSuggestion)>
4321 let mut result = None;
4322 let mut worklist = Vec::new();
4323 let mut seen_modules = FxHashSet();
4324 worklist.push((self.graph_root, Vec::new()));
4326 while let Some((in_module, path_segments)) = worklist.pop() {
4327 // abort if the module is already found
4328 if result.is_some() { break; }
4330 self.populate_module_if_necessary(in_module);
4332 in_module.for_each_child_stable(|ident, _, name_binding| {
4333 // abort if the module is already found or if name_binding is private external
4334 if result.is_some() || !name_binding.vis.is_visible_locally() {
4337 if let Some(module) = name_binding.module() {
4339 let mut path_segments = path_segments.clone();
4340 path_segments.push(ast::PathSegment::from_ident(ident));
4341 if module.def() == Some(module_def) {
4343 span: name_binding.span,
4344 segments: path_segments,
4346 result = Some((module, ImportSuggestion { path: path }));
4348 // add the module to the lookup
4349 if seen_modules.insert(module.def_id().unwrap()) {
4350 worklist.push((module, path_segments));
4360 fn collect_enum_variants(&mut self, enum_def: Def) -> Option<Vec<Path>> {
4361 if let Def::Enum(..) = enum_def {} else {
4362 panic!("Non-enum def passed to collect_enum_variants: {:?}", enum_def)
4365 self.find_module(enum_def).map(|(enum_module, enum_import_suggestion)| {
4366 self.populate_module_if_necessary(enum_module);
4368 let mut variants = Vec::new();
4369 enum_module.for_each_child_stable(|ident, _, name_binding| {
4370 if let Def::Variant(..) = name_binding.def() {
4371 let mut segms = enum_import_suggestion.path.segments.clone();
4372 segms.push(ast::PathSegment::from_ident(ident));
4373 variants.push(Path {
4374 span: name_binding.span,
4383 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
4384 debug!("(recording def) recording {:?} for {}", resolution, node_id);
4385 if let Some(prev_res) = self.def_map.insert(node_id, resolution) {
4386 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
4390 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
4392 ast::VisibilityKind::Public => ty::Visibility::Public,
4393 ast::VisibilityKind::Crate(..) => {
4394 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
4396 ast::VisibilityKind::Inherited => {
4397 ty::Visibility::Restricted(self.current_module.normal_ancestor_id)
4399 ast::VisibilityKind::Restricted { ref path, id, .. } => {
4400 // Visibilities are resolved as global by default, add starting root segment.
4401 let segments = path.make_root().iter().chain(path.segments.iter())
4402 .map(|seg| seg.ident)
4403 .collect::<Vec<_>>();
4404 let def = self.smart_resolve_path_fragment(
4409 PathSource::Visibility,
4410 CrateLint::SimplePath(id),
4412 if def == Def::Err {
4413 ty::Visibility::Public
4415 let vis = ty::Visibility::Restricted(def.def_id());
4416 if self.is_accessible(vis) {
4419 self.session.span_err(path.span, "visibilities can only be restricted \
4420 to ancestor modules");
4421 ty::Visibility::Public
4428 fn is_accessible(&self, vis: ty::Visibility) -> bool {
4429 vis.is_accessible_from(self.current_module.normal_ancestor_id, self)
4432 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
4433 vis.is_accessible_from(module.normal_ancestor_id, self)
4436 fn report_ambiguity_error(
4437 &self, name: Name, span: Span, _lexical: bool,
4438 def1: Def, is_import1: bool, is_glob1: bool, from_expansion1: bool, span1: Span,
4439 def2: Def, is_import2: bool, _is_glob2: bool, _from_expansion2: bool, span2: Span,
4441 let participle = |is_import: bool| if is_import { "imported" } else { "defined" };
4442 let msg1 = format!("`{}` could refer to the name {} here", name, participle(is_import1));
4444 format!("`{}` could also refer to the name {} here", name, participle(is_import2));
4445 let note = if from_expansion1 {
4446 Some(if let Def::Macro(..) = def1 {
4447 format!("macro-expanded {} do not shadow",
4448 if is_import1 { "macro imports" } else { "macros" })
4450 format!("macro-expanded {} do not shadow when used in a macro invocation path",
4451 if is_import1 { "imports" } else { "items" })
4453 } else if is_glob1 {
4454 Some(format!("consider adding an explicit import of `{}` to disambiguate", name))
4459 let mut err = struct_span_err!(self.session, span, E0659, "`{}` is ambiguous", name);
4460 err.span_note(span1, &msg1);
4462 Def::Macro(..) if span2.is_dummy() =>
4463 err.note(&format!("`{}` is also a builtin macro", name)),
4464 _ => err.span_note(span2, &msg2),
4466 if let Some(note) = note {
4472 fn report_errors(&mut self, krate: &Crate) {
4473 self.report_shadowing_errors();
4474 self.report_with_use_injections(krate);
4475 self.report_proc_macro_import(krate);
4476 let mut reported_spans = FxHashSet();
4478 for &(span_use, span_def) in &self.macro_expanded_macro_export_errors {
4479 let msg = "macro-expanded `macro_export` macros from the current crate \
4480 cannot be referred to by absolute paths";
4481 self.session.struct_span_err(span_use, msg)
4482 .span_note(span_def, "the macro is defined here")
4486 for &AmbiguityError { span, name, b1, b2, lexical } in &self.ambiguity_errors {
4487 if reported_spans.insert(span) {
4488 self.report_ambiguity_error(
4489 name, span, lexical,
4490 b1.def(), b1.is_import(), b1.is_glob_import(),
4491 b1.expansion != Mark::root(), b1.span,
4492 b2.def(), b2.is_import(), b2.is_glob_import(),
4493 b2.expansion != Mark::root(), b2.span,
4498 for &PrivacyError(span, name, binding) in &self.privacy_errors {
4499 if !reported_spans.insert(span) { continue }
4500 span_err!(self.session, span, E0603, "{} `{}` is private", binding.descr(), name);
4504 fn report_with_use_injections(&mut self, krate: &Crate) {
4505 for UseError { mut err, candidates, node_id, better } in self.use_injections.drain(..) {
4506 let (span, found_use) = UsePlacementFinder::check(krate, node_id);
4507 if !candidates.is_empty() {
4508 show_candidates(&mut err, span, &candidates, better, found_use);
4514 fn report_shadowing_errors(&mut self) {
4515 let mut reported_errors = FxHashSet();
4516 for binding in replace(&mut self.disallowed_shadowing, Vec::new()) {
4517 if self.resolve_legacy_scope(&binding.parent, binding.ident, false).is_some() &&
4518 reported_errors.insert((binding.ident, binding.span)) {
4519 let msg = format!("`{}` is already in scope", binding.ident);
4520 self.session.struct_span_err(binding.span, &msg)
4521 .note("macro-expanded `macro_rules!`s may not shadow \
4522 existing macros (see RFC 1560)")
4528 fn report_conflict<'b>(&mut self,
4532 new_binding: &NameBinding<'b>,
4533 old_binding: &NameBinding<'b>) {
4534 // Error on the second of two conflicting names
4535 if old_binding.span.lo() > new_binding.span.lo() {
4536 return self.report_conflict(parent, ident, ns, old_binding, new_binding);
4539 let container = match parent.kind {
4540 ModuleKind::Def(Def::Mod(_), _) => "module",
4541 ModuleKind::Def(Def::Trait(_), _) => "trait",
4542 ModuleKind::Block(..) => "block",
4546 let old_noun = match old_binding.is_import() {
4548 false => "definition",
4551 let new_participle = match new_binding.is_import() {
4556 let (name, span) = (ident.name, self.session.source_map().def_span(new_binding.span));
4558 if let Some(s) = self.name_already_seen.get(&name) {
4564 let old_kind = match (ns, old_binding.module()) {
4565 (ValueNS, _) => "value",
4566 (MacroNS, _) => "macro",
4567 (TypeNS, _) if old_binding.is_extern_crate() => "extern crate",
4568 (TypeNS, Some(module)) if module.is_normal() => "module",
4569 (TypeNS, Some(module)) if module.is_trait() => "trait",
4570 (TypeNS, _) => "type",
4573 let msg = format!("the name `{}` is defined multiple times", name);
4575 let mut err = match (old_binding.is_extern_crate(), new_binding.is_extern_crate()) {
4576 (true, true) => struct_span_err!(self.session, span, E0259, "{}", msg),
4577 (true, _) | (_, true) => match new_binding.is_import() && old_binding.is_import() {
4578 true => struct_span_err!(self.session, span, E0254, "{}", msg),
4579 false => struct_span_err!(self.session, span, E0260, "{}", msg),
4581 _ => match (old_binding.is_import(), new_binding.is_import()) {
4582 (false, false) => struct_span_err!(self.session, span, E0428, "{}", msg),
4583 (true, true) => struct_span_err!(self.session, span, E0252, "{}", msg),
4584 _ => struct_span_err!(self.session, span, E0255, "{}", msg),
4588 err.note(&format!("`{}` must be defined only once in the {} namespace of this {}",
4593 err.span_label(span, format!("`{}` re{} here", name, new_participle));
4594 if !old_binding.span.is_dummy() {
4595 err.span_label(self.session.source_map().def_span(old_binding.span),
4596 format!("previous {} of the {} `{}` here", old_noun, old_kind, name));
4599 // See https://github.com/rust-lang/rust/issues/32354
4600 if old_binding.is_import() || new_binding.is_import() {
4601 let binding = if new_binding.is_import() && !new_binding.span.is_dummy() {
4607 let cm = self.session.source_map();
4608 let rename_msg = "You can use `as` to change the binding name of the import";
4610 if let (Ok(snippet), false) = (cm.span_to_snippet(binding.span),
4611 binding.is_renamed_extern_crate()) {
4612 let suggested_name = if name.as_str().chars().next().unwrap().is_uppercase() {
4613 format!("Other{}", name)
4615 format!("other_{}", name)
4618 err.span_suggestion(binding.span,
4620 if snippet.ends_with(';') {
4621 format!("{} as {};",
4622 &snippet[..snippet.len()-1],
4625 format!("{} as {}", snippet, suggested_name)
4628 err.span_label(binding.span, rename_msg);
4633 self.name_already_seen.insert(name, span);
4637 fn is_self_type(path: &[Ident], namespace: Namespace) -> bool {
4638 namespace == TypeNS && path.len() == 1 && path[0].name == keywords::SelfType.name()
4641 fn is_self_value(path: &[Ident], namespace: Namespace) -> bool {
4642 namespace == ValueNS && path.len() == 1 && path[0].name == keywords::SelfValue.name()
4645 fn names_to_string(idents: &[Ident]) -> String {
4646 let mut result = String::new();
4647 for (i, ident) in idents.iter()
4648 .filter(|ident| ident.name != keywords::CrateRoot.name())
4651 result.push_str("::");
4653 result.push_str(&ident.as_str());
4658 fn path_names_to_string(path: &Path) -> String {
4659 names_to_string(&path.segments.iter()
4660 .map(|seg| seg.ident)
4661 .collect::<Vec<_>>())
4664 /// Get the path for an enum and the variant from an `ImportSuggestion` for an enum variant.
4665 fn import_candidate_to_paths(suggestion: &ImportSuggestion) -> (Span, String, String) {
4666 let variant_path = &suggestion.path;
4667 let variant_path_string = path_names_to_string(variant_path);
4669 let path_len = suggestion.path.segments.len();
4670 let enum_path = ast::Path {
4671 span: suggestion.path.span,
4672 segments: suggestion.path.segments[0..path_len - 1].to_vec(),
4674 let enum_path_string = path_names_to_string(&enum_path);
4676 (suggestion.path.span, variant_path_string, enum_path_string)
4680 /// When an entity with a given name is not available in scope, we search for
4681 /// entities with that name in all crates. This method allows outputting the
4682 /// results of this search in a programmer-friendly way
4683 fn show_candidates(err: &mut DiagnosticBuilder,
4684 // This is `None` if all placement locations are inside expansions
4686 candidates: &[ImportSuggestion],
4690 // we want consistent results across executions, but candidates are produced
4691 // by iterating through a hash map, so make sure they are ordered:
4692 let mut path_strings: Vec<_> =
4693 candidates.into_iter().map(|c| path_names_to_string(&c.path)).collect();
4694 path_strings.sort();
4696 let better = if better { "better " } else { "" };
4697 let msg_diff = match path_strings.len() {
4698 1 => " is found in another module, you can import it",
4699 _ => "s are found in other modules, you can import them",
4701 let msg = format!("possible {}candidate{} into scope", better, msg_diff);
4703 if let Some(span) = span {
4704 for candidate in &mut path_strings {
4705 // produce an additional newline to separate the new use statement
4706 // from the directly following item.
4707 let additional_newline = if found_use {
4712 *candidate = format!("use {};\n{}", candidate, additional_newline);
4715 err.span_suggestions(span, &msg, path_strings);
4719 for candidate in path_strings {
4721 msg.push_str(&candidate);
4726 /// A somewhat inefficient routine to obtain the name of a module.
4727 fn module_to_string(module: Module) -> Option<String> {
4728 let mut names = Vec::new();
4730 fn collect_mod(names: &mut Vec<Ident>, module: Module) {
4731 if let ModuleKind::Def(_, name) = module.kind {
4732 if let Some(parent) = module.parent {
4733 names.push(Ident::with_empty_ctxt(name));
4734 collect_mod(names, parent);
4737 // danger, shouldn't be ident?
4738 names.push(Ident::from_str("<opaque>"));
4739 collect_mod(names, module.parent.unwrap());
4742 collect_mod(&mut names, module);
4744 if names.is_empty() {
4747 Some(names_to_string(&names.into_iter()
4749 .collect::<Vec<_>>()))
4752 fn err_path_resolution() -> PathResolution {
4753 PathResolution::new(Def::Err)
4756 #[derive(PartialEq,Copy, Clone)]
4757 pub enum MakeGlobMap {
4762 #[derive(Copy, Clone, Debug)]
4764 /// Do not issue the lint
4767 /// This lint applies to some random path like `impl ::foo::Bar`
4768 /// or whatever. In this case, we can take the span of that path.
4771 /// This lint comes from a `use` statement. In this case, what we
4772 /// care about really is the *root* `use` statement; e.g., if we
4773 /// have nested things like `use a::{b, c}`, we care about the
4775 UsePath { root_id: NodeId, root_span: Span },
4777 /// This is the "trait item" from a fully qualified path. For example,
4778 /// we might be resolving `X::Y::Z` from a path like `<T as X::Y>::Z`.
4779 /// The `path_span` is the span of the to the trait itself (`X::Y`).
4780 QPathTrait { qpath_id: NodeId, qpath_span: Span },
4784 fn node_id(&self) -> Option<NodeId> {
4786 CrateLint::No => None,
4787 CrateLint::SimplePath(id) |
4788 CrateLint::UsePath { root_id: id, .. } |
4789 CrateLint::QPathTrait { qpath_id: id, .. } => Some(id),
4794 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }