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 #![feature(rustc_diagnostic_macros)]
18 #![feature(slice_sort_by_cached_key)]
24 extern crate syntax_pos;
25 extern crate rustc_errors as errors;
29 extern crate rustc_data_structures;
30 extern crate rustc_metadata;
32 pub use rustc::hir::def::{Namespace, PerNS};
34 use self::TypeParameters::*;
37 use rustc::hir::map::{Definitions, DefCollector};
38 use rustc::hir::{self, PrimTy, Bool, Char, Float, Int, Uint, Str};
39 use rustc::middle::cstore::CrateStore;
40 use rustc::session::Session;
42 use rustc::hir::def::*;
43 use rustc::hir::def::Namespace::*;
44 use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, DefId};
46 use rustc::hir::{Freevar, FreevarMap, TraitCandidate, TraitMap, GlobMap};
47 use rustc::util::nodemap::{NodeMap, NodeSet, FxHashMap, FxHashSet, DefIdMap};
49 use rustc_metadata::creader::CrateLoader;
50 use rustc_metadata::cstore::CStore;
52 use syntax::source_map::SourceMap;
53 use syntax::ext::hygiene::{Mark, Transparency, SyntaxContext};
54 use syntax::ast::{self, Name, NodeId, Ident, FloatTy, IntTy, UintTy};
55 use syntax::ext::base::SyntaxExtension;
56 use syntax::ext::base::Determinacy::{self, Determined, Undetermined};
57 use syntax::ext::base::MacroKind;
58 use syntax::symbol::{Symbol, keywords};
59 use syntax::util::lev_distance::find_best_match_for_name;
61 use syntax::visit::{self, FnKind, Visitor};
63 use syntax::ast::{CRATE_NODE_ID, Arm, IsAsync, BindingMode, Block, Crate, Expr, ExprKind};
64 use syntax::ast::{FnDecl, ForeignItem, ForeignItemKind, GenericParamKind, Generics};
65 use syntax::ast::{Item, ItemKind, ImplItem, ImplItemKind};
66 use syntax::ast::{Label, Local, Mutability, Pat, PatKind, Path};
67 use syntax::ast::{QSelf, TraitItemKind, TraitRef, Ty, TyKind};
68 use syntax::feature_gate::{feature_err, GateIssue};
71 use syntax_pos::{Span, DUMMY_SP, MultiSpan};
72 use errors::{DiagnosticBuilder, DiagnosticId};
74 use std::cell::{Cell, RefCell};
76 use std::collections::BTreeSet;
79 use std::mem::replace;
80 use rustc_data_structures::sync::Lrc;
82 use resolve_imports::{ImportDirective, ImportDirectiveSubclass, NameResolution, ImportResolver};
83 use macros::{InvocationData, LegacyBinding};
85 // NB: This module needs to be declared first so diagnostics are
86 // registered before they are used.
91 mod build_reduced_graph;
94 fn is_known_tool(name: Name) -> bool {
95 ["clippy", "rustfmt"].contains(&&*name.as_str())
98 /// A free importable items suggested in case of resolution failure.
99 struct ImportSuggestion {
103 /// A field or associated item from self type suggested in case of resolution failure.
104 enum AssocSuggestion {
111 struct BindingError {
113 origin: BTreeSet<Span>,
114 target: BTreeSet<Span>,
117 impl PartialOrd for BindingError {
118 fn partial_cmp(&self, other: &BindingError) -> Option<cmp::Ordering> {
119 Some(self.cmp(other))
123 impl PartialEq for BindingError {
124 fn eq(&self, other: &BindingError) -> bool {
125 self.name == other.name
129 impl Ord for BindingError {
130 fn cmp(&self, other: &BindingError) -> cmp::Ordering {
131 self.name.cmp(&other.name)
135 enum ResolutionError<'a> {
136 /// error E0401: can't use type parameters from outer function
137 TypeParametersFromOuterFunction(Def),
138 /// error E0403: the name is already used for a type parameter in this type parameter list
139 NameAlreadyUsedInTypeParameterList(Name, &'a Span),
140 /// error E0407: method is not a member of trait
141 MethodNotMemberOfTrait(Name, &'a str),
142 /// error E0437: type is not a member of trait
143 TypeNotMemberOfTrait(Name, &'a str),
144 /// error E0438: const is not a member of trait
145 ConstNotMemberOfTrait(Name, &'a str),
146 /// error E0408: variable `{}` is not bound in all patterns
147 VariableNotBoundInPattern(&'a BindingError),
148 /// error E0409: variable `{}` is bound in inconsistent ways within the same match arm
149 VariableBoundWithDifferentMode(Name, Span),
150 /// error E0415: identifier is bound more than once in this parameter list
151 IdentifierBoundMoreThanOnceInParameterList(&'a str),
152 /// error E0416: identifier is bound more than once in the same pattern
153 IdentifierBoundMoreThanOnceInSamePattern(&'a str),
154 /// error E0426: use of undeclared label
155 UndeclaredLabel(&'a str, Option<Name>),
156 /// error E0429: `self` imports are only allowed within a { } list
157 SelfImportsOnlyAllowedWithin,
158 /// error E0430: `self` import can only appear once in the list
159 SelfImportCanOnlyAppearOnceInTheList,
160 /// error E0431: `self` import can only appear in an import list with a non-empty prefix
161 SelfImportOnlyInImportListWithNonEmptyPrefix,
162 /// error E0432: unresolved import
163 UnresolvedImport(Option<(Span, &'a str, &'a str)>),
164 /// error E0433: failed to resolve
165 FailedToResolve(&'a str),
166 /// error E0434: can't capture dynamic environment in a fn item
167 CannotCaptureDynamicEnvironmentInFnItem,
168 /// error E0435: attempt to use a non-constant value in a constant
169 AttemptToUseNonConstantValueInConstant,
170 /// error E0530: X bindings cannot shadow Ys
171 BindingShadowsSomethingUnacceptable(&'a str, Name, &'a NameBinding<'a>),
172 /// error E0128: type parameters with a default cannot use forward declared identifiers
173 ForwardDeclaredTyParam,
176 /// Combines an error with provided span and emits it
178 /// This takes the error provided, combines it with the span and any additional spans inside the
179 /// error and emits it.
180 fn resolve_error<'sess, 'a>(resolver: &'sess Resolver,
182 resolution_error: ResolutionError<'a>) {
183 resolve_struct_error(resolver, span, resolution_error).emit();
186 fn resolve_struct_error<'sess, 'a>(resolver: &'sess Resolver,
188 resolution_error: ResolutionError<'a>)
189 -> DiagnosticBuilder<'sess> {
190 match resolution_error {
191 ResolutionError::TypeParametersFromOuterFunction(outer_def) => {
192 let mut err = struct_span_err!(resolver.session,
195 "can't use type parameters from outer function");
196 err.span_label(span, "use of type variable from outer function");
198 let cm = resolver.session.source_map();
200 Def::SelfTy(_, maybe_impl_defid) => {
201 if let Some(impl_span) = maybe_impl_defid.map_or(None,
202 |def_id| resolver.definitions.opt_span(def_id)) {
203 err.span_label(reduce_impl_span_to_impl_keyword(cm, impl_span),
204 "`Self` type implicitly declared here, on the `impl`");
207 Def::TyParam(typaram_defid) => {
208 if let Some(typaram_span) = resolver.definitions.opt_span(typaram_defid) {
209 err.span_label(typaram_span, "type variable from outer function");
213 bug!("TypeParametersFromOuterFunction should only be used with Def::SelfTy or \
218 // Try to retrieve the span of the function signature and generate a new message with
219 // a local type parameter
220 let sugg_msg = "try using a local type parameter instead";
221 if let Some((sugg_span, new_snippet)) = cm.generate_local_type_param_snippet(span) {
222 // Suggest the modification to the user
223 err.span_suggestion(sugg_span,
226 } else if let Some(sp) = cm.generate_fn_name_span(span) {
227 err.span_label(sp, "try adding a local type parameter in this method instead");
229 err.help("try using a local type parameter instead");
234 ResolutionError::NameAlreadyUsedInTypeParameterList(name, first_use_span) => {
235 let mut err = struct_span_err!(resolver.session,
238 "the name `{}` is already used for a type parameter \
239 in this type parameter list",
241 err.span_label(span, "already used");
242 err.span_label(first_use_span.clone(), format!("first use of `{}`", name));
245 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
246 let mut err = struct_span_err!(resolver.session,
249 "method `{}` is not a member of trait `{}`",
252 err.span_label(span, format!("not a member of trait `{}`", trait_));
255 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
256 let mut err = struct_span_err!(resolver.session,
259 "type `{}` is not a member of trait `{}`",
262 err.span_label(span, format!("not a member of trait `{}`", trait_));
265 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
266 let mut err = struct_span_err!(resolver.session,
269 "const `{}` is not a member of trait `{}`",
272 err.span_label(span, format!("not a member of trait `{}`", trait_));
275 ResolutionError::VariableNotBoundInPattern(binding_error) => {
276 let target_sp = binding_error.target.iter().cloned().collect::<Vec<_>>();
277 let msp = MultiSpan::from_spans(target_sp.clone());
278 let msg = format!("variable `{}` is not bound in all patterns", binding_error.name);
279 let mut err = resolver.session.struct_span_err_with_code(
282 DiagnosticId::Error("E0408".into()),
284 for sp in target_sp {
285 err.span_label(sp, format!("pattern doesn't bind `{}`", binding_error.name));
287 let origin_sp = binding_error.origin.iter().cloned();
288 for sp in origin_sp {
289 err.span_label(sp, "variable not in all patterns");
293 ResolutionError::VariableBoundWithDifferentMode(variable_name,
294 first_binding_span) => {
295 let mut err = struct_span_err!(resolver.session,
298 "variable `{}` is bound in inconsistent \
299 ways within the same match arm",
301 err.span_label(span, "bound in different ways");
302 err.span_label(first_binding_span, "first binding");
305 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
306 let mut err = struct_span_err!(resolver.session,
309 "identifier `{}` is bound more than once in this parameter list",
311 err.span_label(span, "used as parameter more than once");
314 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
315 let mut err = struct_span_err!(resolver.session,
318 "identifier `{}` is bound more than once in the same pattern",
320 err.span_label(span, "used in a pattern more than once");
323 ResolutionError::UndeclaredLabel(name, lev_candidate) => {
324 let mut err = struct_span_err!(resolver.session,
327 "use of undeclared label `{}`",
329 if let Some(lev_candidate) = lev_candidate {
330 err.span_label(span, format!("did you mean `{}`?", lev_candidate));
332 err.span_label(span, format!("undeclared label `{}`", name));
336 ResolutionError::SelfImportsOnlyAllowedWithin => {
337 struct_span_err!(resolver.session,
341 "`self` imports are only allowed within a { } list")
343 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
344 let mut err = struct_span_err!(resolver.session, span, E0430,
345 "`self` import can only appear once in an import list");
346 err.span_label(span, "can only appear once in an import list");
349 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
350 let mut err = struct_span_err!(resolver.session, span, E0431,
351 "`self` import can only appear in an import list with \
352 a non-empty prefix");
353 err.span_label(span, "can only appear in an import list with a non-empty prefix");
356 ResolutionError::UnresolvedImport(name) => {
357 let (span, msg) = match name {
358 Some((sp, n, _)) => (sp, format!("unresolved import `{}`", n)),
359 None => (span, "unresolved import".to_owned()),
361 let mut err = struct_span_err!(resolver.session, span, E0432, "{}", msg);
362 if let Some((_, _, p)) = name {
363 err.span_label(span, p);
367 ResolutionError::FailedToResolve(msg) => {
368 let mut err = struct_span_err!(resolver.session, span, E0433,
369 "failed to resolve. {}", msg);
370 err.span_label(span, msg);
373 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
374 let mut err = struct_span_err!(resolver.session,
378 "can't capture dynamic environment in a fn item");
379 err.help("use the `|| { ... }` closure form instead");
382 ResolutionError::AttemptToUseNonConstantValueInConstant => {
383 let mut err = struct_span_err!(resolver.session, span, E0435,
384 "attempt to use a non-constant value in a constant");
385 err.span_label(span, "non-constant value");
388 ResolutionError::BindingShadowsSomethingUnacceptable(what_binding, name, binding) => {
389 let shadows_what = PathResolution::new(binding.def()).kind_name();
390 let mut err = struct_span_err!(resolver.session,
393 "{}s cannot shadow {}s", what_binding, shadows_what);
394 err.span_label(span, format!("cannot be named the same as a {}", shadows_what));
395 let participle = if binding.is_import() { "imported" } else { "defined" };
396 let msg = format!("a {} `{}` is {} here", shadows_what, name, participle);
397 err.span_label(binding.span, msg);
400 ResolutionError::ForwardDeclaredTyParam => {
401 let mut err = struct_span_err!(resolver.session, span, E0128,
402 "type parameters with a default cannot use \
403 forward declared identifiers");
405 span, "defaulted type parameters cannot be forward declared".to_string());
411 /// Adjust the impl span so that just the `impl` keyword is taken by removing
412 /// everything after `<` (`"impl<T> Iterator for A<T> {}" -> "impl"`) and
413 /// everything after the first whitespace (`"impl Iterator for A" -> "impl"`)
415 /// Attention: The method used is very fragile since it essentially duplicates the work of the
416 /// parser. If you need to use this function or something similar, please consider updating the
417 /// source_map functions and this function to something more robust.
418 fn reduce_impl_span_to_impl_keyword(cm: &SourceMap, impl_span: Span) -> Span {
419 let impl_span = cm.span_until_char(impl_span, '<');
420 let impl_span = cm.span_until_whitespace(impl_span);
424 #[derive(Copy, Clone, Debug)]
427 binding_mode: BindingMode,
430 /// Map from the name in a pattern to its binding mode.
431 type BindingMap = FxHashMap<Ident, BindingInfo>;
433 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
444 fn descr(self) -> &'static str {
446 PatternSource::Match => "match binding",
447 PatternSource::IfLet => "if let binding",
448 PatternSource::WhileLet => "while let binding",
449 PatternSource::Let => "let binding",
450 PatternSource::For => "for binding",
451 PatternSource::FnParam => "function parameter",
456 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
457 enum AliasPossibility {
462 #[derive(Copy, Clone, Debug)]
463 enum PathSource<'a> {
464 // Type paths `Path`.
466 // Trait paths in bounds or impls.
467 Trait(AliasPossibility),
468 // Expression paths `path`, with optional parent context.
469 Expr(Option<&'a Expr>),
470 // Paths in path patterns `Path`.
472 // Paths in struct expressions and patterns `Path { .. }`.
474 // Paths in tuple struct patterns `Path(..)`.
476 // `m::A::B` in `<T as m::A>::B::C`.
477 TraitItem(Namespace),
478 // Path in `pub(path)`
480 // Path in `use a::b::{...};`
484 impl<'a> PathSource<'a> {
485 fn namespace(self) -> Namespace {
487 PathSource::Type | PathSource::Trait(_) | PathSource::Struct |
488 PathSource::Visibility | PathSource::ImportPrefix => TypeNS,
489 PathSource::Expr(..) | PathSource::Pat | PathSource::TupleStruct => ValueNS,
490 PathSource::TraitItem(ns) => ns,
494 fn global_by_default(self) -> bool {
496 PathSource::Visibility | PathSource::ImportPrefix => true,
497 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
498 PathSource::Struct | PathSource::TupleStruct |
499 PathSource::Trait(_) | PathSource::TraitItem(..) => false,
503 fn defer_to_typeck(self) -> bool {
505 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
506 PathSource::Struct | PathSource::TupleStruct => true,
507 PathSource::Trait(_) | PathSource::TraitItem(..) |
508 PathSource::Visibility | PathSource::ImportPrefix => false,
512 fn descr_expected(self) -> &'static str {
514 PathSource::Type => "type",
515 PathSource::Trait(_) => "trait",
516 PathSource::Pat => "unit struct/variant or constant",
517 PathSource::Struct => "struct, variant or union type",
518 PathSource::TupleStruct => "tuple struct/variant",
519 PathSource::Visibility => "module",
520 PathSource::ImportPrefix => "module or enum",
521 PathSource::TraitItem(ns) => match ns {
522 TypeNS => "associated type",
523 ValueNS => "method or associated constant",
524 MacroNS => bug!("associated macro"),
526 PathSource::Expr(parent) => match parent.map(|p| &p.node) {
527 // "function" here means "anything callable" rather than `Def::Fn`,
528 // this is not precise but usually more helpful than just "value".
529 Some(&ExprKind::Call(..)) => "function",
535 fn is_expected(self, def: Def) -> bool {
537 PathSource::Type => match def {
538 Def::Struct(..) | Def::Union(..) | Def::Enum(..) |
539 Def::Trait(..) | Def::TyAlias(..) | Def::AssociatedTy(..) |
540 Def::PrimTy(..) | Def::TyParam(..) | Def::SelfTy(..) |
541 Def::Existential(..) |
542 Def::ForeignTy(..) => true,
545 PathSource::Trait(AliasPossibility::No) => match def {
546 Def::Trait(..) => true,
549 PathSource::Trait(AliasPossibility::Maybe) => match def {
550 Def::Trait(..) => true,
551 Def::TraitAlias(..) => true,
554 PathSource::Expr(..) => match def {
555 Def::StructCtor(_, CtorKind::Const) | Def::StructCtor(_, CtorKind::Fn) |
556 Def::VariantCtor(_, CtorKind::Const) | Def::VariantCtor(_, CtorKind::Fn) |
557 Def::Const(..) | Def::Static(..) | Def::Local(..) | Def::Upvar(..) |
558 Def::Fn(..) | Def::Method(..) | Def::AssociatedConst(..) => true,
561 PathSource::Pat => match def {
562 Def::StructCtor(_, CtorKind::Const) |
563 Def::VariantCtor(_, CtorKind::Const) |
564 Def::Const(..) | Def::AssociatedConst(..) => true,
567 PathSource::TupleStruct => match def {
568 Def::StructCtor(_, CtorKind::Fn) | Def::VariantCtor(_, CtorKind::Fn) => true,
571 PathSource::Struct => match def {
572 Def::Struct(..) | Def::Union(..) | Def::Variant(..) |
573 Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) => true,
576 PathSource::TraitItem(ns) => match def {
577 Def::AssociatedConst(..) | Def::Method(..) if ns == ValueNS => true,
578 Def::AssociatedTy(..) if ns == TypeNS => true,
581 PathSource::ImportPrefix => match def {
582 Def::Mod(..) | Def::Enum(..) => true,
585 PathSource::Visibility => match def {
586 Def::Mod(..) => true,
592 fn error_code(self, has_unexpected_resolution: bool) -> &'static str {
593 __diagnostic_used!(E0404);
594 __diagnostic_used!(E0405);
595 __diagnostic_used!(E0412);
596 __diagnostic_used!(E0422);
597 __diagnostic_used!(E0423);
598 __diagnostic_used!(E0425);
599 __diagnostic_used!(E0531);
600 __diagnostic_used!(E0532);
601 __diagnostic_used!(E0573);
602 __diagnostic_used!(E0574);
603 __diagnostic_used!(E0575);
604 __diagnostic_used!(E0576);
605 __diagnostic_used!(E0577);
606 __diagnostic_used!(E0578);
607 match (self, has_unexpected_resolution) {
608 (PathSource::Trait(_), true) => "E0404",
609 (PathSource::Trait(_), false) => "E0405",
610 (PathSource::Type, true) => "E0573",
611 (PathSource::Type, false) => "E0412",
612 (PathSource::Struct, true) => "E0574",
613 (PathSource::Struct, false) => "E0422",
614 (PathSource::Expr(..), true) => "E0423",
615 (PathSource::Expr(..), false) => "E0425",
616 (PathSource::Pat, true) | (PathSource::TupleStruct, true) => "E0532",
617 (PathSource::Pat, false) | (PathSource::TupleStruct, false) => "E0531",
618 (PathSource::TraitItem(..), true) => "E0575",
619 (PathSource::TraitItem(..), false) => "E0576",
620 (PathSource::Visibility, true) | (PathSource::ImportPrefix, true) => "E0577",
621 (PathSource::Visibility, false) | (PathSource::ImportPrefix, false) => "E0578",
626 struct UsePlacementFinder {
627 target_module: NodeId,
632 impl UsePlacementFinder {
633 fn check(krate: &Crate, target_module: NodeId) -> (Option<Span>, bool) {
634 let mut finder = UsePlacementFinder {
639 visit::walk_crate(&mut finder, krate);
640 (finder.span, finder.found_use)
644 impl<'tcx> Visitor<'tcx> for UsePlacementFinder {
647 module: &'tcx ast::Mod,
649 _: &[ast::Attribute],
652 if self.span.is_some() {
655 if node_id != self.target_module {
656 visit::walk_mod(self, module);
659 // find a use statement
660 for item in &module.items {
662 ItemKind::Use(..) => {
663 // don't suggest placing a use before the prelude
664 // import or other generated ones
665 if item.span.ctxt().outer().expn_info().is_none() {
666 self.span = Some(item.span.shrink_to_lo());
667 self.found_use = true;
671 // don't place use before extern crate
672 ItemKind::ExternCrate(_) => {}
673 // but place them before the first other item
674 _ => if self.span.map_or(true, |span| item.span < span ) {
675 if item.span.ctxt().outer().expn_info().is_none() {
676 // don't insert between attributes and an item
677 if item.attrs.is_empty() {
678 self.span = Some(item.span.shrink_to_lo());
680 // find the first attribute on the item
681 for attr in &item.attrs {
682 if self.span.map_or(true, |span| attr.span < span) {
683 self.span = Some(attr.span.shrink_to_lo());
694 /// This thing walks the whole crate in DFS manner, visiting each item, resolving names as it goes.
695 impl<'a, 'tcx, 'cl> Visitor<'tcx> for Resolver<'a, 'cl> {
696 fn visit_item(&mut self, item: &'tcx Item) {
697 self.resolve_item(item);
699 fn visit_arm(&mut self, arm: &'tcx Arm) {
700 self.resolve_arm(arm);
702 fn visit_block(&mut self, block: &'tcx Block) {
703 self.resolve_block(block);
705 fn visit_anon_const(&mut self, constant: &'tcx ast::AnonConst) {
706 self.with_constant_rib(|this| {
707 visit::walk_anon_const(this, constant);
710 fn visit_expr(&mut self, expr: &'tcx Expr) {
711 self.resolve_expr(expr, None);
713 fn visit_local(&mut self, local: &'tcx Local) {
714 self.resolve_local(local);
716 fn visit_ty(&mut self, ty: &'tcx Ty) {
718 TyKind::Path(ref qself, ref path) => {
719 self.smart_resolve_path(ty.id, qself.as_ref(), path, PathSource::Type);
721 TyKind::ImplicitSelf => {
722 let self_ty = keywords::SelfType.ident();
723 let def = self.resolve_ident_in_lexical_scope(self_ty, TypeNS, Some(ty.id), ty.span)
724 .map_or(Def::Err, |d| d.def());
725 self.record_def(ty.id, PathResolution::new(def));
729 visit::walk_ty(self, ty);
731 fn visit_poly_trait_ref(&mut self,
732 tref: &'tcx ast::PolyTraitRef,
733 m: &'tcx ast::TraitBoundModifier) {
734 self.smart_resolve_path(tref.trait_ref.ref_id, None,
735 &tref.trait_ref.path, PathSource::Trait(AliasPossibility::Maybe));
736 visit::walk_poly_trait_ref(self, tref, m);
738 fn visit_foreign_item(&mut self, foreign_item: &'tcx ForeignItem) {
739 let type_parameters = match foreign_item.node {
740 ForeignItemKind::Fn(_, ref generics) => {
741 HasTypeParameters(generics, ItemRibKind)
743 ForeignItemKind::Static(..) => NoTypeParameters,
744 ForeignItemKind::Ty => NoTypeParameters,
745 ForeignItemKind::Macro(..) => NoTypeParameters,
747 self.with_type_parameter_rib(type_parameters, |this| {
748 visit::walk_foreign_item(this, foreign_item);
751 fn visit_fn(&mut self,
752 function_kind: FnKind<'tcx>,
753 declaration: &'tcx FnDecl,
757 let (rib_kind, asyncness) = match function_kind {
758 FnKind::ItemFn(_, ref header, ..) =>
759 (ItemRibKind, header.asyncness),
760 FnKind::Method(_, ref sig, _, _) =>
761 (TraitOrImplItemRibKind, sig.header.asyncness),
762 FnKind::Closure(_) =>
763 // Async closures aren't resolved through `visit_fn`-- they're
764 // processed separately
765 (ClosureRibKind(node_id), IsAsync::NotAsync),
768 // Create a value rib for the function.
769 self.ribs[ValueNS].push(Rib::new(rib_kind));
771 // Create a label rib for the function.
772 self.label_ribs.push(Rib::new(rib_kind));
774 // Add each argument to the rib.
775 let mut bindings_list = FxHashMap();
776 for argument in &declaration.inputs {
777 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
779 self.visit_ty(&argument.ty);
781 debug!("(resolving function) recorded argument");
783 visit::walk_fn_ret_ty(self, &declaration.output);
785 // Resolve the function body, potentially inside the body of an async closure
786 if let IsAsync::Async { closure_id, .. } = asyncness {
787 let rib_kind = ClosureRibKind(closure_id);
788 self.ribs[ValueNS].push(Rib::new(rib_kind));
789 self.label_ribs.push(Rib::new(rib_kind));
792 match function_kind {
793 FnKind::ItemFn(.., body) |
794 FnKind::Method(.., body) => {
795 self.visit_block(body);
797 FnKind::Closure(body) => {
798 self.visit_expr(body);
802 // Leave the body of the async closure
803 if asyncness.is_async() {
804 self.label_ribs.pop();
805 self.ribs[ValueNS].pop();
808 debug!("(resolving function) leaving function");
810 self.label_ribs.pop();
811 self.ribs[ValueNS].pop();
813 fn visit_generics(&mut self, generics: &'tcx Generics) {
814 // For type parameter defaults, we have to ban access
815 // to following type parameters, as the Substs can only
816 // provide previous type parameters as they're built. We
817 // put all the parameters on the ban list and then remove
818 // them one by one as they are processed and become available.
819 let mut default_ban_rib = Rib::new(ForwardTyParamBanRibKind);
820 let mut found_default = false;
821 default_ban_rib.bindings.extend(generics.params.iter()
822 .filter_map(|param| match param.kind {
823 GenericParamKind::Lifetime { .. } => None,
824 GenericParamKind::Type { ref default, .. } => {
825 found_default |= default.is_some();
827 Some((Ident::with_empty_ctxt(param.ident.name), Def::Err))
834 for param in &generics.params {
836 GenericParamKind::Lifetime { .. } => self.visit_generic_param(param),
837 GenericParamKind::Type { ref default, .. } => {
838 for bound in ¶m.bounds {
839 self.visit_param_bound(bound);
842 if let Some(ref ty) = default {
843 self.ribs[TypeNS].push(default_ban_rib);
845 default_ban_rib = self.ribs[TypeNS].pop().unwrap();
848 // Allow all following defaults to refer to this type parameter.
849 default_ban_rib.bindings.remove(&Ident::with_empty_ctxt(param.ident.name));
853 for p in &generics.where_clause.predicates {
854 self.visit_where_predicate(p);
859 #[derive(Copy, Clone)]
860 enum TypeParameters<'a, 'b> {
862 HasTypeParameters(// Type parameters.
865 // The kind of the rib used for type parameters.
869 /// The rib kind controls the translation of local
870 /// definitions (`Def::Local`) to upvars (`Def::Upvar`).
871 #[derive(Copy, Clone, Debug)]
873 /// No translation needs to be applied.
876 /// We passed through a closure scope at the given node ID.
877 /// Translate upvars as appropriate.
878 ClosureRibKind(NodeId /* func id */),
880 /// We passed through an impl or trait and are now in one of its
881 /// methods or associated types. Allow references to ty params that impl or trait
882 /// binds. Disallow any other upvars (including other ty params that are
884 TraitOrImplItemRibKind,
886 /// We passed through an item scope. Disallow upvars.
889 /// We're in a constant item. Can't refer to dynamic stuff.
892 /// We passed through a module.
893 ModuleRibKind(Module<'a>),
895 /// We passed through a `macro_rules!` statement
896 MacroDefinition(DefId),
898 /// All bindings in this rib are type parameters that can't be used
899 /// from the default of a type parameter because they're not declared
900 /// before said type parameter. Also see the `visit_generics` override.
901 ForwardTyParamBanRibKind,
906 /// A rib represents a scope names can live in. Note that these appear in many places, not just
907 /// around braces. At any place where the list of accessible names (of the given namespace)
908 /// changes or a new restrictions on the name accessibility are introduced, a new rib is put onto a
909 /// stack. This may be, for example, a `let` statement (because it introduces variables), a macro,
912 /// Different [rib kinds](enum.RibKind) are transparent for different names.
914 /// The resolution keeps a separate stack of ribs as it traverses the AST for each namespace. When
915 /// resolving, the name is looked up from inside out.
918 bindings: FxHashMap<Ident, Def>,
923 fn new(kind: RibKind<'a>) -> Rib<'a> {
925 bindings: FxHashMap(),
931 /// An intermediate resolution result.
933 /// This refers to the thing referred by a name. The difference between `Def` and `Item` is that
934 /// items are visible in their whole block, while defs only from the place they are defined
936 enum LexicalScopeBinding<'a> {
937 Item(&'a NameBinding<'a>),
941 impl<'a> LexicalScopeBinding<'a> {
942 fn item(self) -> Option<&'a NameBinding<'a>> {
944 LexicalScopeBinding::Item(binding) => Some(binding),
949 fn def(self) -> Def {
951 LexicalScopeBinding::Item(binding) => binding.def(),
952 LexicalScopeBinding::Def(def) => def,
957 #[derive(Copy, Clone, Debug)]
958 pub enum ModuleOrUniformRoot<'a> {
962 /// The `{{root}}` (`CrateRoot` aka "global") / `extern` initial segment
963 /// in which external crates resolve, and also `crate` (only in `{{root}}`,
964 /// but *not* `extern`), in the Rust 2018 edition.
968 #[derive(Clone, Debug)]
969 enum PathResult<'a> {
970 Module(ModuleOrUniformRoot<'a>),
971 NonModule(PathResolution),
973 Failed(Span, String, bool /* is the error from the last segment? */),
977 /// An anonymous module, eg. just a block.
982 /// { // This is an anonymous module
983 /// f(); // This resolves to (2) as we are inside the block.
986 /// f(); // Resolves to (1)
990 /// Any module with a name.
994 /// * A normal module ‒ either `mod from_file;` or `mod from_block { }`.
995 /// * A trait or an enum (it implicitly contains associated types, methods and variant
1000 /// One node in the tree of modules.
1001 pub struct ModuleData<'a> {
1002 parent: Option<Module<'a>>,
1005 // The def id of the closest normal module (`mod`) ancestor (including this module).
1006 normal_ancestor_id: DefId,
1008 resolutions: RefCell<FxHashMap<(Ident, Namespace), &'a RefCell<NameResolution<'a>>>>,
1009 legacy_macro_resolutions: RefCell<Vec<(Mark, Ident, MacroKind, Option<Def>)>>,
1010 macro_resolutions: RefCell<Vec<(Box<[Ident]>, Span)>>,
1012 // Macro invocations that can expand into items in this module.
1013 unresolved_invocations: RefCell<FxHashSet<Mark>>,
1015 no_implicit_prelude: bool,
1017 glob_importers: RefCell<Vec<&'a ImportDirective<'a>>>,
1018 globs: RefCell<Vec<&'a ImportDirective<'a>>>,
1020 // Used to memoize the traits in this module for faster searches through all traits in scope.
1021 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
1023 // Whether this module is populated. If not populated, any attempt to
1024 // access the children must be preceded with a
1025 // `populate_module_if_necessary` call.
1026 populated: Cell<bool>,
1028 /// Span of the module itself. Used for error reporting.
1034 type Module<'a> = &'a ModuleData<'a>;
1036 impl<'a> ModuleData<'a> {
1037 fn new(parent: Option<Module<'a>>,
1039 normal_ancestor_id: DefId,
1041 span: Span) -> Self {
1046 resolutions: RefCell::new(FxHashMap()),
1047 legacy_macro_resolutions: RefCell::new(Vec::new()),
1048 macro_resolutions: RefCell::new(Vec::new()),
1049 unresolved_invocations: RefCell::new(FxHashSet()),
1050 no_implicit_prelude: false,
1051 glob_importers: RefCell::new(Vec::new()),
1052 globs: RefCell::new(Vec::new()),
1053 traits: RefCell::new(None),
1054 populated: Cell::new(normal_ancestor_id.is_local()),
1060 fn for_each_child<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
1061 for (&(ident, ns), name_resolution) in self.resolutions.borrow().iter() {
1062 name_resolution.borrow().binding.map(|binding| f(ident, ns, binding));
1066 fn for_each_child_stable<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
1067 let resolutions = self.resolutions.borrow();
1068 let mut resolutions = resolutions.iter().collect::<Vec<_>>();
1069 resolutions.sort_by_cached_key(|&(&(ident, ns), _)| (ident.as_str(), ns));
1070 for &(&(ident, ns), &resolution) in resolutions.iter() {
1071 resolution.borrow().binding.map(|binding| f(ident, ns, binding));
1075 fn def(&self) -> Option<Def> {
1077 ModuleKind::Def(def, _) => Some(def),
1082 fn def_id(&self) -> Option<DefId> {
1083 self.def().as_ref().map(Def::def_id)
1086 // `self` resolves to the first module ancestor that `is_normal`.
1087 fn is_normal(&self) -> bool {
1089 ModuleKind::Def(Def::Mod(_), _) => true,
1094 fn is_trait(&self) -> bool {
1096 ModuleKind::Def(Def::Trait(_), _) => true,
1101 fn is_local(&self) -> bool {
1102 self.normal_ancestor_id.is_local()
1105 fn nearest_item_scope(&'a self) -> Module<'a> {
1106 if self.is_trait() { self.parent.unwrap() } else { self }
1110 impl<'a> fmt::Debug for ModuleData<'a> {
1111 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1112 write!(f, "{:?}", self.def())
1116 /// Records a possibly-private value, type, or module definition.
1117 #[derive(Clone, Debug)]
1118 pub struct NameBinding<'a> {
1119 kind: NameBindingKind<'a>,
1122 vis: ty::Visibility,
1125 pub trait ToNameBinding<'a> {
1126 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
1129 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
1130 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
1135 #[derive(Clone, Debug)]
1136 enum NameBindingKind<'a> {
1137 Def(Def, /* is_macro_export */ bool),
1140 binding: &'a NameBinding<'a>,
1141 directive: &'a ImportDirective<'a>,
1145 b1: &'a NameBinding<'a>,
1146 b2: &'a NameBinding<'a>,
1150 struct PrivacyError<'a>(Span, Name, &'a NameBinding<'a>);
1152 struct UseError<'a> {
1153 err: DiagnosticBuilder<'a>,
1154 /// Attach `use` statements for these candidates
1155 candidates: Vec<ImportSuggestion>,
1156 /// The node id of the module to place the use statements in
1158 /// Whether the diagnostic should state that it's "better"
1162 struct AmbiguityError<'a> {
1166 b1: &'a NameBinding<'a>,
1167 b2: &'a NameBinding<'a>,
1170 impl<'a> NameBinding<'a> {
1171 fn module(&self) -> Option<Module<'a>> {
1173 NameBindingKind::Module(module) => Some(module),
1174 NameBindingKind::Import { binding, .. } => binding.module(),
1179 fn def(&self) -> Def {
1181 NameBindingKind::Def(def, _) => def,
1182 NameBindingKind::Module(module) => module.def().unwrap(),
1183 NameBindingKind::Import { binding, .. } => binding.def(),
1184 NameBindingKind::Ambiguity { .. } => Def::Err,
1188 fn def_ignoring_ambiguity(&self) -> Def {
1190 NameBindingKind::Import { binding, .. } => binding.def_ignoring_ambiguity(),
1191 NameBindingKind::Ambiguity { b1, .. } => b1.def_ignoring_ambiguity(),
1196 fn get_macro<'b: 'a>(&self, resolver: &mut Resolver<'a, 'b>) -> Lrc<SyntaxExtension> {
1197 resolver.get_macro(self.def_ignoring_ambiguity())
1200 // We sometimes need to treat variants as `pub` for backwards compatibility
1201 fn pseudo_vis(&self) -> ty::Visibility {
1202 if self.is_variant() && self.def().def_id().is_local() {
1203 ty::Visibility::Public
1209 fn is_variant(&self) -> bool {
1211 NameBindingKind::Def(Def::Variant(..), _) |
1212 NameBindingKind::Def(Def::VariantCtor(..), _) => true,
1217 fn is_extern_crate(&self) -> bool {
1219 NameBindingKind::Import {
1220 directive: &ImportDirective {
1221 subclass: ImportDirectiveSubclass::ExternCrate(_), ..
1228 fn is_import(&self) -> bool {
1230 NameBindingKind::Import { .. } => true,
1235 fn is_renamed_extern_crate(&self) -> bool {
1236 if let NameBindingKind::Import { directive, ..} = self.kind {
1237 if let ImportDirectiveSubclass::ExternCrate(Some(_)) = directive.subclass {
1244 fn is_glob_import(&self) -> bool {
1246 NameBindingKind::Import { directive, .. } => directive.is_glob(),
1247 NameBindingKind::Ambiguity { b1, .. } => b1.is_glob_import(),
1252 fn is_importable(&self) -> bool {
1254 Def::AssociatedConst(..) | Def::Method(..) | Def::AssociatedTy(..) => false,
1259 fn is_macro_def(&self) -> bool {
1261 NameBindingKind::Def(Def::Macro(..), _) => true,
1266 fn descr(&self) -> &'static str {
1267 if self.is_extern_crate() { "extern crate" } else { self.def().kind_name() }
1271 /// Interns the names of the primitive types.
1273 /// All other types are defined somewhere and possibly imported, but the primitive ones need
1274 /// special handling, since they have no place of origin.
1275 struct PrimitiveTypeTable {
1276 primitive_types: FxHashMap<Name, PrimTy>,
1279 impl PrimitiveTypeTable {
1280 fn new() -> PrimitiveTypeTable {
1281 let mut table = PrimitiveTypeTable { primitive_types: FxHashMap() };
1283 table.intern("bool", Bool);
1284 table.intern("char", Char);
1285 table.intern("f32", Float(FloatTy::F32));
1286 table.intern("f64", Float(FloatTy::F64));
1287 table.intern("isize", Int(IntTy::Isize));
1288 table.intern("i8", Int(IntTy::I8));
1289 table.intern("i16", Int(IntTy::I16));
1290 table.intern("i32", Int(IntTy::I32));
1291 table.intern("i64", Int(IntTy::I64));
1292 table.intern("i128", Int(IntTy::I128));
1293 table.intern("str", Str);
1294 table.intern("usize", Uint(UintTy::Usize));
1295 table.intern("u8", Uint(UintTy::U8));
1296 table.intern("u16", Uint(UintTy::U16));
1297 table.intern("u32", Uint(UintTy::U32));
1298 table.intern("u64", Uint(UintTy::U64));
1299 table.intern("u128", Uint(UintTy::U128));
1303 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1304 self.primitive_types.insert(Symbol::intern(string), primitive_type);
1308 /// The main resolver class.
1310 /// This is the visitor that walks the whole crate.
1311 pub struct Resolver<'a, 'b: 'a> {
1312 session: &'a Session,
1315 pub definitions: Definitions,
1317 graph_root: Module<'a>,
1319 prelude: Option<Module<'a>>,
1320 extern_prelude: FxHashSet<Name>,
1322 /// n.b. This is used only for better diagnostics, not name resolution itself.
1323 has_self: FxHashSet<DefId>,
1325 /// Names of fields of an item `DefId` accessible with dot syntax.
1326 /// Used for hints during error reporting.
1327 field_names: FxHashMap<DefId, Vec<Name>>,
1329 /// All imports known to succeed or fail.
1330 determined_imports: Vec<&'a ImportDirective<'a>>,
1332 /// All non-determined imports.
1333 indeterminate_imports: Vec<&'a ImportDirective<'a>>,
1335 /// The module that represents the current item scope.
1336 current_module: Module<'a>,
1338 /// The current set of local scopes for types and values.
1339 /// FIXME #4948: Reuse ribs to avoid allocation.
1340 ribs: PerNS<Vec<Rib<'a>>>,
1342 /// The current set of local scopes, for labels.
1343 label_ribs: Vec<Rib<'a>>,
1345 /// The trait that the current context can refer to.
1346 current_trait_ref: Option<(Module<'a>, TraitRef)>,
1348 /// The current self type if inside an impl (used for better errors).
1349 current_self_type: Option<Ty>,
1351 /// The idents for the primitive types.
1352 primitive_type_table: PrimitiveTypeTable,
1355 import_map: ImportMap,
1356 pub freevars: FreevarMap,
1357 freevars_seen: NodeMap<NodeMap<usize>>,
1358 pub export_map: ExportMap,
1359 pub trait_map: TraitMap,
1361 /// A map from nodes to anonymous modules.
1362 /// Anonymous modules are pseudo-modules that are implicitly created around items
1363 /// contained within blocks.
1365 /// For example, if we have this:
1373 /// There will be an anonymous module created around `g` with the ID of the
1374 /// entry block for `f`.
1375 block_map: NodeMap<Module<'a>>,
1376 module_map: FxHashMap<DefId, Module<'a>>,
1377 extern_module_map: FxHashMap<(DefId, bool /* MacrosOnly? */), Module<'a>>,
1379 pub make_glob_map: bool,
1380 /// Maps imports to the names of items actually imported (this actually maps
1381 /// all imports, but only glob imports are actually interesting).
1382 pub glob_map: GlobMap,
1384 used_imports: FxHashSet<(NodeId, Namespace)>,
1385 pub maybe_unused_trait_imports: NodeSet,
1386 pub maybe_unused_extern_crates: Vec<(NodeId, Span)>,
1388 /// A list of labels as of yet unused. Labels will be removed from this map when
1389 /// they are used (in a `break` or `continue` statement)
1390 pub unused_labels: FxHashMap<NodeId, Span>,
1392 /// privacy errors are delayed until the end in order to deduplicate them
1393 privacy_errors: Vec<PrivacyError<'a>>,
1394 /// ambiguity errors are delayed for deduplication
1395 ambiguity_errors: Vec<AmbiguityError<'a>>,
1396 /// `use` injections are delayed for better placement and deduplication
1397 use_injections: Vec<UseError<'a>>,
1398 /// `use` injections for proc macros wrongly imported with #[macro_use]
1399 proc_mac_errors: Vec<macros::ProcMacError>,
1400 /// crate-local macro expanded `macro_export` referred to by a module-relative path
1401 macro_expanded_macro_export_errors: BTreeSet<(Span, Span)>,
1402 /// macro-expanded `macro_rules` shadowing existing macros
1403 disallowed_shadowing: Vec<&'a LegacyBinding<'a>>,
1405 arenas: &'a ResolverArenas<'a>,
1406 dummy_binding: &'a NameBinding<'a>,
1408 crate_loader: &'a mut CrateLoader<'b>,
1409 macro_names: FxHashSet<Ident>,
1410 macro_prelude: FxHashMap<Name, &'a NameBinding<'a>>,
1411 pub all_macros: FxHashMap<Name, Def>,
1412 macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>,
1413 macro_defs: FxHashMap<Mark, DefId>,
1414 local_macro_def_scopes: FxHashMap<NodeId, Module<'a>>,
1415 pub whitelisted_legacy_custom_derives: Vec<Name>,
1416 pub found_unresolved_macro: bool,
1418 /// List of crate local macros that we need to warn about as being unused.
1419 /// Right now this only includes macro_rules! macros, and macros 2.0.
1420 unused_macros: FxHashSet<DefId>,
1422 /// Maps the `Mark` of an expansion to its containing module or block.
1423 invocations: FxHashMap<Mark, &'a InvocationData<'a>>,
1425 /// Avoid duplicated errors for "name already defined".
1426 name_already_seen: FxHashMap<Name, Span>,
1428 /// A set of procedural macros imported by `#[macro_use]` that have already been warned about
1429 warned_proc_macros: FxHashSet<Name>,
1431 potentially_unused_imports: Vec<&'a ImportDirective<'a>>,
1433 /// This table maps struct IDs into struct constructor IDs,
1434 /// it's not used during normal resolution, only for better error reporting.
1435 struct_constructors: DefIdMap<(Def, ty::Visibility)>,
1437 /// Only used for better errors on `fn(): fn()`
1438 current_type_ascription: Vec<Span>,
1440 injected_crate: Option<Module<'a>>,
1442 /// Only supposed to be used by rustdoc, otherwise should be false.
1443 pub ignore_extern_prelude_feature: bool,
1446 /// Nothing really interesting here, it just provides memory for the rest of the crate.
1447 pub struct ResolverArenas<'a> {
1448 modules: arena::TypedArena<ModuleData<'a>>,
1449 local_modules: RefCell<Vec<Module<'a>>>,
1450 name_bindings: arena::TypedArena<NameBinding<'a>>,
1451 import_directives: arena::TypedArena<ImportDirective<'a>>,
1452 name_resolutions: arena::TypedArena<RefCell<NameResolution<'a>>>,
1453 invocation_data: arena::TypedArena<InvocationData<'a>>,
1454 legacy_bindings: arena::TypedArena<LegacyBinding<'a>>,
1457 impl<'a> ResolverArenas<'a> {
1458 fn alloc_module(&'a self, module: ModuleData<'a>) -> Module<'a> {
1459 let module = self.modules.alloc(module);
1460 if module.def_id().map(|def_id| def_id.is_local()).unwrap_or(true) {
1461 self.local_modules.borrow_mut().push(module);
1465 fn local_modules(&'a self) -> ::std::cell::Ref<'a, Vec<Module<'a>>> {
1466 self.local_modules.borrow()
1468 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1469 self.name_bindings.alloc(name_binding)
1471 fn alloc_import_directive(&'a self, import_directive: ImportDirective<'a>)
1472 -> &'a ImportDirective {
1473 self.import_directives.alloc(import_directive)
1475 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1476 self.name_resolutions.alloc(Default::default())
1478 fn alloc_invocation_data(&'a self, expansion_data: InvocationData<'a>)
1479 -> &'a InvocationData<'a> {
1480 self.invocation_data.alloc(expansion_data)
1482 fn alloc_legacy_binding(&'a self, binding: LegacyBinding<'a>) -> &'a LegacyBinding<'a> {
1483 self.legacy_bindings.alloc(binding)
1487 impl<'a, 'b: 'a, 'cl: 'b> ty::DefIdTree for &'a Resolver<'b, 'cl> {
1488 fn parent(self, id: DefId) -> Option<DefId> {
1490 LOCAL_CRATE => self.definitions.def_key(id.index).parent,
1491 _ => self.cstore.def_key(id).parent,
1492 }.map(|index| DefId { index, ..id })
1496 /// This interface is used through the AST→HIR step, to embed full paths into the HIR. After that
1497 /// the resolver is no longer needed as all the relevant information is inline.
1498 impl<'a, 'cl> hir::lowering::Resolver for Resolver<'a, 'cl> {
1499 fn resolve_hir_path(&mut self, path: &mut hir::Path, is_value: bool) {
1500 self.resolve_hir_path_cb(path, is_value,
1501 |resolver, span, error| resolve_error(resolver, span, error))
1504 fn resolve_str_path(
1507 crate_root: Option<&str>,
1508 components: &[&str],
1509 args: Option<P<hir::GenericArgs>>,
1512 let mut segments = iter::once(keywords::CrateRoot.ident())
1514 crate_root.into_iter()
1515 .chain(components.iter().cloned())
1516 .map(Ident::from_str)
1517 ).map(hir::PathSegment::from_ident).collect::<Vec<_>>();
1519 if let Some(args) = args {
1520 let ident = segments.last().unwrap().ident;
1521 *segments.last_mut().unwrap() = hir::PathSegment {
1528 let mut path = hir::Path {
1531 segments: segments.into(),
1534 self.resolve_hir_path(&mut path, is_value);
1538 fn get_resolution(&mut self, id: NodeId) -> Option<PathResolution> {
1539 self.def_map.get(&id).cloned()
1542 fn get_import(&mut self, id: NodeId) -> PerNS<Option<PathResolution>> {
1543 self.import_map.get(&id).cloned().unwrap_or_default()
1546 fn definitions(&mut self) -> &mut Definitions {
1547 &mut self.definitions
1551 impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
1552 /// Rustdoc uses this to resolve things in a recoverable way. ResolutionError<'a>
1553 /// isn't something that can be returned because it can't be made to live that long,
1554 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
1555 /// just that an error occurred.
1556 pub fn resolve_str_path_error(&mut self, span: Span, path_str: &str, is_value: bool)
1557 -> Result<hir::Path, ()> {
1559 let mut errored = false;
1561 let mut path = if path_str.starts_with("::") {
1565 segments: iter::once(keywords::CrateRoot.ident()).chain({
1566 path_str.split("::").skip(1).map(Ident::from_str)
1567 }).map(hir::PathSegment::from_ident).collect(),
1573 segments: path_str.split("::").map(Ident::from_str)
1574 .map(hir::PathSegment::from_ident).collect(),
1577 self.resolve_hir_path_cb(&mut path, is_value, |_, _, _| errored = true);
1578 if errored || path.def == Def::Err {
1585 /// resolve_hir_path, but takes a callback in case there was an error
1586 fn resolve_hir_path_cb<F>(&mut self, path: &mut hir::Path, is_value: bool, error_callback: F)
1587 where F: for<'c, 'b> FnOnce(&'c mut Resolver, Span, ResolutionError<'b>)
1589 let namespace = if is_value { ValueNS } else { TypeNS };
1590 let hir::Path { ref segments, span, ref mut def } = *path;
1591 let path: Vec<_> = segments.iter().map(|seg| seg.ident).collect();
1592 // FIXME (Manishearth): Intra doc links won't get warned of epoch changes
1593 match self.resolve_path(None, &path, Some(namespace), true, span, CrateLint::No) {
1594 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
1595 *def = module.def().unwrap(),
1596 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 =>
1597 *def = path_res.base_def(),
1598 PathResult::NonModule(..) => match self.resolve_path(
1606 PathResult::Failed(span, msg, _) => {
1607 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1611 PathResult::Module(ModuleOrUniformRoot::UniformRoot(_)) |
1612 PathResult::Indeterminate => unreachable!(),
1613 PathResult::Failed(span, msg, _) => {
1614 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1620 impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
1621 pub fn new(session: &'a Session,
1625 make_glob_map: MakeGlobMap,
1626 crate_loader: &'a mut CrateLoader<'crateloader>,
1627 arenas: &'a ResolverArenas<'a>)
1628 -> Resolver<'a, 'crateloader> {
1629 let root_def_id = DefId::local(CRATE_DEF_INDEX);
1630 let root_module_kind = ModuleKind::Def(Def::Mod(root_def_id), keywords::Invalid.name());
1631 let graph_root = arenas.alloc_module(ModuleData {
1632 no_implicit_prelude: attr::contains_name(&krate.attrs, "no_implicit_prelude"),
1633 ..ModuleData::new(None, root_module_kind, root_def_id, Mark::root(), krate.span)
1635 let mut module_map = FxHashMap();
1636 module_map.insert(DefId::local(CRATE_DEF_INDEX), graph_root);
1638 let mut definitions = Definitions::new();
1639 DefCollector::new(&mut definitions, Mark::root())
1640 .collect_root(crate_name, session.local_crate_disambiguator());
1642 let mut extern_prelude: FxHashSet<Name> =
1643 session.opts.externs.iter().map(|kv| Symbol::intern(kv.0)).collect();
1644 if !attr::contains_name(&krate.attrs, "no_core") {
1645 if !attr::contains_name(&krate.attrs, "no_std") {
1646 extern_prelude.insert(Symbol::intern("std"));
1648 extern_prelude.insert(Symbol::intern("core"));
1652 let mut invocations = FxHashMap();
1653 invocations.insert(Mark::root(),
1654 arenas.alloc_invocation_data(InvocationData::root(graph_root)));
1656 let mut macro_defs = FxHashMap();
1657 macro_defs.insert(Mark::root(), root_def_id);
1666 // The outermost module has def ID 0; this is not reflected in the
1672 has_self: FxHashSet(),
1673 field_names: FxHashMap(),
1675 determined_imports: Vec::new(),
1676 indeterminate_imports: Vec::new(),
1678 current_module: graph_root,
1680 value_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1681 type_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1682 macro_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1684 label_ribs: Vec::new(),
1686 current_trait_ref: None,
1687 current_self_type: None,
1689 primitive_type_table: PrimitiveTypeTable::new(),
1692 import_map: NodeMap(),
1693 freevars: NodeMap(),
1694 freevars_seen: NodeMap(),
1695 export_map: FxHashMap(),
1696 trait_map: NodeMap(),
1698 block_map: NodeMap(),
1699 extern_module_map: FxHashMap(),
1701 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1702 glob_map: NodeMap(),
1704 used_imports: FxHashSet(),
1705 maybe_unused_trait_imports: NodeSet(),
1706 maybe_unused_extern_crates: Vec::new(),
1708 unused_labels: FxHashMap(),
1710 privacy_errors: Vec::new(),
1711 ambiguity_errors: Vec::new(),
1712 use_injections: Vec::new(),
1713 proc_mac_errors: Vec::new(),
1714 disallowed_shadowing: Vec::new(),
1715 macro_expanded_macro_export_errors: BTreeSet::new(),
1718 dummy_binding: arenas.alloc_name_binding(NameBinding {
1719 kind: NameBindingKind::Def(Def::Err, false),
1720 expansion: Mark::root(),
1722 vis: ty::Visibility::Public,
1726 macro_names: FxHashSet(),
1727 macro_prelude: FxHashMap(),
1728 all_macros: FxHashMap(),
1729 macro_map: FxHashMap(),
1732 local_macro_def_scopes: FxHashMap(),
1733 name_already_seen: FxHashMap(),
1734 whitelisted_legacy_custom_derives: Vec::new(),
1735 warned_proc_macros: FxHashSet(),
1736 potentially_unused_imports: Vec::new(),
1737 struct_constructors: DefIdMap(),
1738 found_unresolved_macro: false,
1739 unused_macros: FxHashSet(),
1740 current_type_ascription: Vec::new(),
1741 injected_crate: None,
1742 ignore_extern_prelude_feature: false,
1746 pub fn arenas() -> ResolverArenas<'a> {
1748 modules: arena::TypedArena::new(),
1749 local_modules: RefCell::new(Vec::new()),
1750 name_bindings: arena::TypedArena::new(),
1751 import_directives: arena::TypedArena::new(),
1752 name_resolutions: arena::TypedArena::new(),
1753 invocation_data: arena::TypedArena::new(),
1754 legacy_bindings: arena::TypedArena::new(),
1758 /// Runs the function on each namespace.
1759 fn per_ns<F: FnMut(&mut Self, Namespace)>(&mut self, mut f: F) {
1765 fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
1767 match self.macro_defs.get(&ctxt.outer()) {
1768 Some(&def_id) => return def_id,
1769 None => ctxt.remove_mark(),
1774 /// Entry point to crate resolution.
1775 pub fn resolve_crate(&mut self, krate: &Crate) {
1776 ImportResolver { resolver: self }.finalize_imports();
1777 self.current_module = self.graph_root;
1778 self.finalize_current_module_macro_resolutions();
1780 visit::walk_crate(self, krate);
1782 check_unused::check_crate(self, krate);
1783 self.report_errors(krate);
1784 self.crate_loader.postprocess(krate);
1791 normal_ancestor_id: DefId,
1795 let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expansion, span);
1796 self.arenas.alloc_module(module)
1799 fn record_use(&mut self, ident: Ident, ns: Namespace, binding: &'a NameBinding<'a>, span: Span)
1800 -> bool /* true if an error was reported */ {
1801 match binding.kind {
1802 NameBindingKind::Import { directive, binding, ref used }
1805 directive.used.set(true);
1806 self.used_imports.insert((directive.id, ns));
1807 self.add_to_glob_map(directive.id, ident);
1808 self.record_use(ident, ns, binding, span)
1810 NameBindingKind::Import { .. } => false,
1811 NameBindingKind::Ambiguity { b1, b2 } => {
1812 self.ambiguity_errors.push(AmbiguityError {
1813 span, name: ident.name, lexical: false, b1, b2,
1821 fn add_to_glob_map(&mut self, id: NodeId, ident: Ident) {
1822 if self.make_glob_map {
1823 self.glob_map.entry(id).or_default().insert(ident.name);
1827 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1828 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1829 /// `ident` in the first scope that defines it (or None if no scopes define it).
1831 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1832 /// the items are defined in the block. For example,
1835 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1838 /// g(); // This resolves to the local variable `g` since it shadows the item.
1842 /// Invariant: This must only be called during main resolution, not during
1843 /// import resolution.
1844 fn resolve_ident_in_lexical_scope(&mut self,
1847 record_used_id: Option<NodeId>,
1849 -> Option<LexicalScopeBinding<'a>> {
1850 let record_used = record_used_id.is_some();
1851 assert!(ns == TypeNS || ns == ValueNS);
1853 ident.span = if ident.name == keywords::SelfType.name() {
1854 // FIXME(jseyfried) improve `Self` hygiene
1855 ident.span.with_ctxt(SyntaxContext::empty())
1860 ident = ident.modern_and_legacy();
1863 // Walk backwards up the ribs in scope.
1864 let mut module = self.graph_root;
1865 for i in (0 .. self.ribs[ns].len()).rev() {
1866 if let Some(def) = self.ribs[ns][i].bindings.get(&ident).cloned() {
1867 // The ident resolves to a type parameter or local variable.
1868 return Some(LexicalScopeBinding::Def(
1869 self.adjust_local_def(ns, i, def, record_used, path_span)
1873 module = match self.ribs[ns][i].kind {
1874 ModuleRibKind(module) => module,
1875 MacroDefinition(def) if def == self.macro_def(ident.span.ctxt()) => {
1876 // If an invocation of this macro created `ident`, give up on `ident`
1877 // and switch to `ident`'s source from the macro definition.
1878 ident.span.remove_mark();
1884 let item = self.resolve_ident_in_module_unadjusted(
1885 ModuleOrUniformRoot::Module(module),
1892 if let Ok(binding) = item {
1893 // The ident resolves to an item.
1894 return Some(LexicalScopeBinding::Item(binding));
1898 ModuleKind::Block(..) => {}, // We can see through blocks
1903 ident.span = ident.span.modern();
1904 let mut poisoned = None;
1906 let opt_module = if let Some(node_id) = record_used_id {
1907 self.hygienic_lexical_parent_with_compatibility_fallback(module, &mut ident.span,
1908 node_id, &mut poisoned)
1910 self.hygienic_lexical_parent(module, &mut ident.span)
1912 module = unwrap_or!(opt_module, break);
1913 let orig_current_module = self.current_module;
1914 self.current_module = module; // Lexical resolutions can never be a privacy error.
1915 let result = self.resolve_ident_in_module_unadjusted(
1916 ModuleOrUniformRoot::Module(module),
1923 self.current_module = orig_current_module;
1927 if let Some(node_id) = poisoned {
1928 self.session.buffer_lint_with_diagnostic(
1929 lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
1930 node_id, ident.span,
1931 &format!("cannot find {} `{}` in this scope", ns.descr(), ident),
1932 lint::builtin::BuiltinLintDiagnostics::
1933 ProcMacroDeriveResolutionFallback(ident.span),
1936 return Some(LexicalScopeBinding::Item(binding))
1938 Err(Determined) => continue,
1939 Err(Undetermined) =>
1940 span_bug!(ident.span, "undetermined resolution during main resolution pass"),
1944 if !module.no_implicit_prelude {
1945 // `record_used` means that we don't try to load crates during speculative resolution
1946 if record_used && ns == TypeNS && self.extern_prelude.contains(&ident.name) {
1947 if !self.session.features_untracked().extern_prelude &&
1948 !self.ignore_extern_prelude_feature {
1949 feature_err(&self.session.parse_sess, "extern_prelude",
1950 ident.span, GateIssue::Language,
1951 "access to extern crates through prelude is experimental").emit();
1954 let crate_id = self.crate_loader.process_path_extern(ident.name, ident.span);
1955 let crate_root = self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
1956 self.populate_module_if_necessary(crate_root);
1958 let binding = (crate_root, ty::Visibility::Public,
1959 ident.span, Mark::root()).to_name_binding(self.arenas);
1960 return Some(LexicalScopeBinding::Item(binding));
1962 if ns == TypeNS && is_known_tool(ident.name) {
1963 let binding = (Def::ToolMod, ty::Visibility::Public,
1964 ident.span, Mark::root()).to_name_binding(self.arenas);
1965 return Some(LexicalScopeBinding::Item(binding));
1967 if let Some(prelude) = self.prelude {
1968 if let Ok(binding) = self.resolve_ident_in_module_unadjusted(
1969 ModuleOrUniformRoot::Module(prelude),
1976 return Some(LexicalScopeBinding::Item(binding));
1984 fn hygienic_lexical_parent(&mut self, module: Module<'a>, span: &mut Span)
1985 -> Option<Module<'a>> {
1986 if !module.expansion.is_descendant_of(span.ctxt().outer()) {
1987 return Some(self.macro_def_scope(span.remove_mark()));
1990 if let ModuleKind::Block(..) = module.kind {
1991 return Some(module.parent.unwrap());
1997 fn hygienic_lexical_parent_with_compatibility_fallback(&mut self, module: Module<'a>,
1998 span: &mut Span, node_id: NodeId,
1999 poisoned: &mut Option<NodeId>)
2000 -> Option<Module<'a>> {
2001 if let module @ Some(..) = self.hygienic_lexical_parent(module, span) {
2005 // We need to support the next case under a deprecation warning
2008 // ---- begin: this comes from a proc macro derive
2009 // mod implementation_details {
2010 // // Note that `MyStruct` is not in scope here.
2011 // impl SomeTrait for MyStruct { ... }
2015 // So we have to fall back to the module's parent during lexical resolution in this case.
2016 if let Some(parent) = module.parent {
2017 // Inner module is inside the macro, parent module is outside of the macro.
2018 if module.expansion != parent.expansion &&
2019 module.expansion.is_descendant_of(parent.expansion) {
2020 // The macro is a proc macro derive
2021 if module.expansion.looks_like_proc_macro_derive() {
2022 if parent.expansion.is_descendant_of(span.ctxt().outer()) {
2023 *poisoned = Some(node_id);
2024 return module.parent;
2033 fn resolve_ident_in_module(&mut self,
2034 module: ModuleOrUniformRoot<'a>,
2039 -> Result<&'a NameBinding<'a>, Determinacy> {
2040 ident.span = ident.span.modern();
2041 let orig_current_module = self.current_module;
2042 if let ModuleOrUniformRoot::Module(module) = module {
2043 if let Some(def) = ident.span.adjust(module.expansion) {
2044 self.current_module = self.macro_def_scope(def);
2047 let result = self.resolve_ident_in_module_unadjusted(
2048 module, ident, ns, false, record_used, span,
2050 self.current_module = orig_current_module;
2054 fn resolve_crate_root(&mut self, ident: Ident) -> Module<'a> {
2055 let mut ctxt = ident.span.ctxt();
2056 let mark = if ident.name == keywords::DollarCrate.name() {
2057 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
2058 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
2059 // as described in `SyntaxContext::apply_mark`, so we ignore prepended modern marks.
2060 // FIXME: This is only a guess and it doesn't work correctly for `macro_rules!`
2061 // definitions actually produced by `macro` and `macro` definitions produced by
2062 // `macro_rules!`, but at least such configurations are not stable yet.
2063 ctxt = ctxt.modern_and_legacy();
2064 let mut iter = ctxt.marks().into_iter().rev().peekable();
2065 let mut result = None;
2066 // Find the last modern mark from the end if it exists.
2067 while let Some(&(mark, transparency)) = iter.peek() {
2068 if transparency == Transparency::Opaque {
2069 result = Some(mark);
2075 // Then find the last legacy mark from the end if it exists.
2076 for (mark, transparency) in iter {
2077 if transparency == Transparency::SemiTransparent {
2078 result = Some(mark);
2085 ctxt = ctxt.modern();
2086 ctxt.adjust(Mark::root())
2088 let module = match mark {
2089 Some(def) => self.macro_def_scope(def),
2090 None => return self.graph_root,
2092 self.get_module(DefId { index: CRATE_DEF_INDEX, ..module.normal_ancestor_id })
2095 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
2096 let mut module = self.get_module(module.normal_ancestor_id);
2097 while module.span.ctxt().modern() != *ctxt {
2098 let parent = module.parent.unwrap_or_else(|| self.macro_def_scope(ctxt.remove_mark()));
2099 module = self.get_module(parent.normal_ancestor_id);
2106 // We maintain a list of value ribs and type ribs.
2108 // Simultaneously, we keep track of the current position in the module
2109 // graph in the `current_module` pointer. When we go to resolve a name in
2110 // the value or type namespaces, we first look through all the ribs and
2111 // then query the module graph. When we resolve a name in the module
2112 // namespace, we can skip all the ribs (since nested modules are not
2113 // allowed within blocks in Rust) and jump straight to the current module
2116 // Named implementations are handled separately. When we find a method
2117 // call, we consult the module node to find all of the implementations in
2118 // scope. This information is lazily cached in the module node. We then
2119 // generate a fake "implementation scope" containing all the
2120 // implementations thus found, for compatibility with old resolve pass.
2122 pub fn with_scope<F, T>(&mut self, id: NodeId, f: F) -> T
2123 where F: FnOnce(&mut Resolver) -> T
2125 let id = self.definitions.local_def_id(id);
2126 let module = self.module_map.get(&id).cloned(); // clones a reference
2127 if let Some(module) = module {
2128 // Move down in the graph.
2129 let orig_module = replace(&mut self.current_module, module);
2130 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(module)));
2131 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(module)));
2133 self.finalize_current_module_macro_resolutions();
2136 self.current_module = orig_module;
2137 self.ribs[ValueNS].pop();
2138 self.ribs[TypeNS].pop();
2145 /// Searches the current set of local scopes for labels. Returns the first non-None label that
2146 /// is returned by the given predicate function
2148 /// Stops after meeting a closure.
2149 fn search_label<P, R>(&self, mut ident: Ident, pred: P) -> Option<R>
2150 where P: Fn(&Rib, Ident) -> Option<R>
2152 for rib in self.label_ribs.iter().rev() {
2155 // If an invocation of this macro created `ident`, give up on `ident`
2156 // and switch to `ident`'s source from the macro definition.
2157 MacroDefinition(def) => {
2158 if def == self.macro_def(ident.span.ctxt()) {
2159 ident.span.remove_mark();
2163 // Do not resolve labels across function boundary
2167 let r = pred(rib, ident);
2175 fn resolve_item(&mut self, item: &Item) {
2176 let name = item.ident.name;
2177 debug!("(resolving item) resolving {}", name);
2180 ItemKind::Ty(_, ref generics) |
2181 ItemKind::Fn(_, _, ref generics, _) |
2182 ItemKind::Existential(_, ref generics) => {
2183 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind),
2184 |this| visit::walk_item(this, item));
2187 ItemKind::Enum(_, ref generics) |
2188 ItemKind::Struct(_, ref generics) |
2189 ItemKind::Union(_, ref generics) => {
2190 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2191 let item_def_id = this.definitions.local_def_id(item.id);
2192 if this.session.features_untracked().self_in_typedefs {
2193 this.with_self_rib(Def::SelfTy(None, Some(item_def_id)), |this| {
2194 visit::walk_item(this, item);
2197 visit::walk_item(this, item);
2202 ItemKind::Impl(.., ref generics, ref opt_trait_ref, ref self_type, ref impl_items) =>
2203 self.resolve_implementation(generics,
2209 ItemKind::Trait(.., ref generics, ref bounds, ref trait_items) => {
2210 // Create a new rib for the trait-wide type parameters.
2211 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2212 let local_def_id = this.definitions.local_def_id(item.id);
2213 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2214 this.visit_generics(generics);
2215 walk_list!(this, visit_param_bound, bounds);
2217 for trait_item in trait_items {
2218 let type_parameters = HasTypeParameters(&trait_item.generics,
2219 TraitOrImplItemRibKind);
2220 this.with_type_parameter_rib(type_parameters, |this| {
2221 match trait_item.node {
2222 TraitItemKind::Const(ref ty, ref default) => {
2225 // Only impose the restrictions of
2226 // ConstRibKind for an actual constant
2227 // expression in a provided default.
2228 if let Some(ref expr) = *default{
2229 this.with_constant_rib(|this| {
2230 this.visit_expr(expr);
2234 TraitItemKind::Method(_, _) => {
2235 visit::walk_trait_item(this, trait_item)
2237 TraitItemKind::Type(..) => {
2238 visit::walk_trait_item(this, trait_item)
2240 TraitItemKind::Macro(_) => {
2241 panic!("unexpanded macro in resolve!")
2250 ItemKind::TraitAlias(ref generics, ref bounds) => {
2251 // Create a new rib for the trait-wide type parameters.
2252 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2253 let local_def_id = this.definitions.local_def_id(item.id);
2254 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2255 this.visit_generics(generics);
2256 walk_list!(this, visit_param_bound, bounds);
2261 ItemKind::Mod(_) | ItemKind::ForeignMod(_) => {
2262 self.with_scope(item.id, |this| {
2263 visit::walk_item(this, item);
2267 ItemKind::Static(ref ty, _, ref expr) |
2268 ItemKind::Const(ref ty, ref expr) => {
2269 self.with_item_rib(|this| {
2271 this.with_constant_rib(|this| {
2272 this.visit_expr(expr);
2277 ItemKind::Use(ref use_tree) => {
2278 // Imports are resolved as global by default, add starting root segment.
2280 segments: use_tree.prefix.make_root().into_iter().collect(),
2281 span: use_tree.span,
2283 self.resolve_use_tree(item.id, use_tree.span, item.id, use_tree, &path);
2286 ItemKind::ExternCrate(_) | ItemKind::MacroDef(..) | ItemKind::GlobalAsm(_) => {
2287 // do nothing, these are just around to be encoded
2290 ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"),
2294 /// For the most part, use trees are desugared into `ImportDirective` instances
2295 /// when building the reduced graph (see `build_reduced_graph_for_use_tree`). But
2296 /// there is one special case we handle here: an empty nested import like
2297 /// `a::{b::{}}`, which desugares into...no import directives.
2298 fn resolve_use_tree(
2303 use_tree: &ast::UseTree,
2306 match use_tree.kind {
2307 ast::UseTreeKind::Nested(ref items) => {
2309 segments: prefix.segments
2311 .chain(use_tree.prefix.segments.iter())
2314 span: prefix.span.to(use_tree.prefix.span),
2317 if items.len() == 0 {
2318 // Resolve prefix of an import with empty braces (issue #28388).
2319 self.smart_resolve_path_with_crate_lint(
2323 PathSource::ImportPrefix,
2324 CrateLint::UsePath { root_id, root_span },
2327 for &(ref tree, nested_id) in items {
2328 self.resolve_use_tree(root_id, root_span, nested_id, tree, &path);
2332 ast::UseTreeKind::Simple(..) => {},
2333 ast::UseTreeKind::Glob => {},
2337 fn with_type_parameter_rib<'b, F>(&'b mut self, type_parameters: TypeParameters<'a, 'b>, f: F)
2338 where F: FnOnce(&mut Resolver)
2340 match type_parameters {
2341 HasTypeParameters(generics, rib_kind) => {
2342 let mut function_type_rib = Rib::new(rib_kind);
2343 let mut seen_bindings = FxHashMap();
2344 for param in &generics.params {
2346 GenericParamKind::Lifetime { .. } => {}
2347 GenericParamKind::Type { .. } => {
2348 let ident = param.ident.modern();
2349 debug!("with_type_parameter_rib: {}", param.id);
2351 if seen_bindings.contains_key(&ident) {
2352 let span = seen_bindings.get(&ident).unwrap();
2353 let err = ResolutionError::NameAlreadyUsedInTypeParameterList(
2357 resolve_error(self, param.ident.span, err);
2359 seen_bindings.entry(ident).or_insert(param.ident.span);
2361 // Plain insert (no renaming).
2362 let def = Def::TyParam(self.definitions.local_def_id(param.id));
2363 function_type_rib.bindings.insert(ident, def);
2364 self.record_def(param.id, PathResolution::new(def));
2368 self.ribs[TypeNS].push(function_type_rib);
2371 NoTypeParameters => {
2378 if let HasTypeParameters(..) = type_parameters {
2379 self.ribs[TypeNS].pop();
2383 fn with_label_rib<F>(&mut self, f: F)
2384 where F: FnOnce(&mut Resolver)
2386 self.label_ribs.push(Rib::new(NormalRibKind));
2388 self.label_ribs.pop();
2391 fn with_item_rib<F>(&mut self, f: F)
2392 where F: FnOnce(&mut Resolver)
2394 self.ribs[ValueNS].push(Rib::new(ItemRibKind));
2395 self.ribs[TypeNS].push(Rib::new(ItemRibKind));
2397 self.ribs[TypeNS].pop();
2398 self.ribs[ValueNS].pop();
2401 fn with_constant_rib<F>(&mut self, f: F)
2402 where F: FnOnce(&mut Resolver)
2404 self.ribs[ValueNS].push(Rib::new(ConstantItemRibKind));
2405 self.label_ribs.push(Rib::new(ConstantItemRibKind));
2407 self.label_ribs.pop();
2408 self.ribs[ValueNS].pop();
2411 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2412 where F: FnOnce(&mut Resolver) -> T
2414 // Handle nested impls (inside fn bodies)
2415 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2416 let result = f(self);
2417 self.current_self_type = previous_value;
2421 /// This is called to resolve a trait reference from an `impl` (i.e. `impl Trait for Foo`)
2422 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
2423 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2425 let mut new_val = None;
2426 let mut new_id = None;
2427 if let Some(trait_ref) = opt_trait_ref {
2428 let path: Vec<_> = trait_ref.path.segments.iter()
2429 .map(|seg| seg.ident)
2431 let def = self.smart_resolve_path_fragment(
2435 trait_ref.path.span,
2436 PathSource::Trait(AliasPossibility::No),
2437 CrateLint::SimplePath(trait_ref.ref_id),
2439 if def != Def::Err {
2440 new_id = Some(def.def_id());
2441 let span = trait_ref.path.span;
2442 if let PathResult::Module(ModuleOrUniformRoot::Module(module)) =
2449 CrateLint::SimplePath(trait_ref.ref_id),
2452 new_val = Some((module, trait_ref.clone()));
2456 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2457 let result = f(self, new_id);
2458 self.current_trait_ref = original_trait_ref;
2462 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2463 where F: FnOnce(&mut Resolver)
2465 let mut self_type_rib = Rib::new(NormalRibKind);
2467 // plain insert (no renaming, types are not currently hygienic....)
2468 self_type_rib.bindings.insert(keywords::SelfType.ident(), self_def);
2469 self.ribs[TypeNS].push(self_type_rib);
2471 self.ribs[TypeNS].pop();
2474 fn resolve_implementation(&mut self,
2475 generics: &Generics,
2476 opt_trait_reference: &Option<TraitRef>,
2479 impl_items: &[ImplItem]) {
2480 // If applicable, create a rib for the type parameters.
2481 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2482 // Dummy self type for better errors if `Self` is used in the trait path.
2483 this.with_self_rib(Def::SelfTy(None, None), |this| {
2484 // Resolve the trait reference, if necessary.
2485 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2486 let item_def_id = this.definitions.local_def_id(item_id);
2487 this.with_self_rib(Def::SelfTy(trait_id, Some(item_def_id)), |this| {
2488 if let Some(trait_ref) = opt_trait_reference.as_ref() {
2489 // Resolve type arguments in the trait path.
2490 visit::walk_trait_ref(this, trait_ref);
2492 // Resolve the self type.
2493 this.visit_ty(self_type);
2494 // Resolve the type parameters.
2495 this.visit_generics(generics);
2496 // Resolve the items within the impl.
2497 this.with_current_self_type(self_type, |this| {
2498 for impl_item in impl_items {
2499 this.resolve_visibility(&impl_item.vis);
2501 // We also need a new scope for the impl item type parameters.
2502 let type_parameters = HasTypeParameters(&impl_item.generics,
2503 TraitOrImplItemRibKind);
2504 this.with_type_parameter_rib(type_parameters, |this| {
2505 use self::ResolutionError::*;
2506 match impl_item.node {
2507 ImplItemKind::Const(..) => {
2508 // If this is a trait impl, ensure the const
2510 this.check_trait_item(impl_item.ident,
2513 |n, s| ConstNotMemberOfTrait(n, s));
2514 this.with_constant_rib(|this|
2515 visit::walk_impl_item(this, impl_item)
2518 ImplItemKind::Method(..) => {
2519 // If this is a trait impl, ensure the method
2521 this.check_trait_item(impl_item.ident,
2524 |n, s| MethodNotMemberOfTrait(n, s));
2526 visit::walk_impl_item(this, impl_item);
2528 ImplItemKind::Type(ref ty) => {
2529 // If this is a trait impl, ensure the type
2531 this.check_trait_item(impl_item.ident,
2534 |n, s| TypeNotMemberOfTrait(n, s));
2538 ImplItemKind::Existential(ref bounds) => {
2539 // If this is a trait impl, ensure the type
2541 this.check_trait_item(impl_item.ident,
2544 |n, s| TypeNotMemberOfTrait(n, s));
2546 for bound in bounds {
2547 this.visit_param_bound(bound);
2550 ImplItemKind::Macro(_) =>
2551 panic!("unexpanded macro in resolve!"),
2562 fn check_trait_item<F>(&mut self, ident: Ident, ns: Namespace, span: Span, err: F)
2563 where F: FnOnce(Name, &str) -> ResolutionError
2565 // If there is a TraitRef in scope for an impl, then the method must be in the
2567 if let Some((module, _)) = self.current_trait_ref {
2568 if self.resolve_ident_in_module(
2569 ModuleOrUniformRoot::Module(module),
2575 let path = &self.current_trait_ref.as_ref().unwrap().1.path;
2576 resolve_error(self, span, err(ident.name, &path_names_to_string(path)));
2581 fn resolve_local(&mut self, local: &Local) {
2582 // Resolve the type.
2583 walk_list!(self, visit_ty, &local.ty);
2585 // Resolve the initializer.
2586 walk_list!(self, visit_expr, &local.init);
2588 // Resolve the pattern.
2589 self.resolve_pattern(&local.pat, PatternSource::Let, &mut FxHashMap());
2592 // build a map from pattern identifiers to binding-info's.
2593 // this is done hygienically. This could arise for a macro
2594 // that expands into an or-pattern where one 'x' was from the
2595 // user and one 'x' came from the macro.
2596 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2597 let mut binding_map = FxHashMap();
2599 pat.walk(&mut |pat| {
2600 if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node {
2601 if sub_pat.is_some() || match self.def_map.get(&pat.id).map(|res| res.base_def()) {
2602 Some(Def::Local(..)) => true,
2605 let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode };
2606 binding_map.insert(ident, binding_info);
2615 // check that all of the arms in an or-pattern have exactly the
2616 // same set of bindings, with the same binding modes for each.
2617 fn check_consistent_bindings(&mut self, pats: &[P<Pat>]) {
2618 if pats.is_empty() {
2622 let mut missing_vars = FxHashMap();
2623 let mut inconsistent_vars = FxHashMap();
2624 for (i, p) in pats.iter().enumerate() {
2625 let map_i = self.binding_mode_map(&p);
2627 for (j, q) in pats.iter().enumerate() {
2632 let map_j = self.binding_mode_map(&q);
2633 for (&key, &binding_i) in &map_i {
2634 if map_j.len() == 0 { // Account for missing bindings when
2635 let binding_error = missing_vars // map_j has none.
2637 .or_insert(BindingError {
2639 origin: BTreeSet::new(),
2640 target: BTreeSet::new(),
2642 binding_error.origin.insert(binding_i.span);
2643 binding_error.target.insert(q.span);
2645 for (&key_j, &binding_j) in &map_j {
2646 match map_i.get(&key_j) {
2647 None => { // missing binding
2648 let binding_error = missing_vars
2650 .or_insert(BindingError {
2652 origin: BTreeSet::new(),
2653 target: BTreeSet::new(),
2655 binding_error.origin.insert(binding_j.span);
2656 binding_error.target.insert(p.span);
2658 Some(binding_i) => { // check consistent binding
2659 if binding_i.binding_mode != binding_j.binding_mode {
2662 .or_insert((binding_j.span, binding_i.span));
2670 let mut missing_vars = missing_vars.iter().collect::<Vec<_>>();
2671 missing_vars.sort();
2672 for (_, v) in missing_vars {
2674 *v.origin.iter().next().unwrap(),
2675 ResolutionError::VariableNotBoundInPattern(v));
2677 let mut inconsistent_vars = inconsistent_vars.iter().collect::<Vec<_>>();
2678 inconsistent_vars.sort();
2679 for (name, v) in inconsistent_vars {
2680 resolve_error(self, v.0, ResolutionError::VariableBoundWithDifferentMode(*name, v.1));
2684 fn resolve_arm(&mut self, arm: &Arm) {
2685 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2687 let mut bindings_list = FxHashMap();
2688 for pattern in &arm.pats {
2689 self.resolve_pattern(&pattern, PatternSource::Match, &mut bindings_list);
2692 // This has to happen *after* we determine which pat_idents are variants
2693 self.check_consistent_bindings(&arm.pats);
2695 walk_list!(self, visit_expr, &arm.guard);
2696 self.visit_expr(&arm.body);
2698 self.ribs[ValueNS].pop();
2701 fn resolve_block(&mut self, block: &Block) {
2702 debug!("(resolving block) entering block");
2703 // Move down in the graph, if there's an anonymous module rooted here.
2704 let orig_module = self.current_module;
2705 let anonymous_module = self.block_map.get(&block.id).cloned(); // clones a reference
2707 let mut num_macro_definition_ribs = 0;
2708 if let Some(anonymous_module) = anonymous_module {
2709 debug!("(resolving block) found anonymous module, moving down");
2710 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2711 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2712 self.current_module = anonymous_module;
2713 self.finalize_current_module_macro_resolutions();
2715 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2718 // Descend into the block.
2719 for stmt in &block.stmts {
2720 if let ast::StmtKind::Item(ref item) = stmt.node {
2721 if let ast::ItemKind::MacroDef(..) = item.node {
2722 num_macro_definition_ribs += 1;
2723 let def = self.definitions.local_def_id(item.id);
2724 self.ribs[ValueNS].push(Rib::new(MacroDefinition(def)));
2725 self.label_ribs.push(Rib::new(MacroDefinition(def)));
2729 self.visit_stmt(stmt);
2733 self.current_module = orig_module;
2734 for _ in 0 .. num_macro_definition_ribs {
2735 self.ribs[ValueNS].pop();
2736 self.label_ribs.pop();
2738 self.ribs[ValueNS].pop();
2739 if anonymous_module.is_some() {
2740 self.ribs[TypeNS].pop();
2742 debug!("(resolving block) leaving block");
2745 fn fresh_binding(&mut self,
2748 outer_pat_id: NodeId,
2749 pat_src: PatternSource,
2750 bindings: &mut FxHashMap<Ident, NodeId>)
2752 // Add the binding to the local ribs, if it
2753 // doesn't already exist in the bindings map. (We
2754 // must not add it if it's in the bindings map
2755 // because that breaks the assumptions later
2756 // passes make about or-patterns.)
2757 let ident = ident.modern_and_legacy();
2758 let mut def = Def::Local(pat_id);
2759 match bindings.get(&ident).cloned() {
2760 Some(id) if id == outer_pat_id => {
2761 // `Variant(a, a)`, error
2765 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2769 Some(..) if pat_src == PatternSource::FnParam => {
2770 // `fn f(a: u8, a: u8)`, error
2774 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2778 Some(..) if pat_src == PatternSource::Match ||
2779 pat_src == PatternSource::IfLet ||
2780 pat_src == PatternSource::WhileLet => {
2781 // `Variant1(a) | Variant2(a)`, ok
2782 // Reuse definition from the first `a`.
2783 def = self.ribs[ValueNS].last_mut().unwrap().bindings[&ident];
2786 span_bug!(ident.span, "two bindings with the same name from \
2787 unexpected pattern source {:?}", pat_src);
2790 // A completely fresh binding, add to the lists if it's valid.
2791 if ident.name != keywords::Invalid.name() {
2792 bindings.insert(ident, outer_pat_id);
2793 self.ribs[ValueNS].last_mut().unwrap().bindings.insert(ident, def);
2798 PathResolution::new(def)
2801 fn resolve_pattern(&mut self,
2803 pat_src: PatternSource,
2804 // Maps idents to the node ID for the
2805 // outermost pattern that binds them.
2806 bindings: &mut FxHashMap<Ident, NodeId>) {
2807 // Visit all direct subpatterns of this pattern.
2808 let outer_pat_id = pat.id;
2809 pat.walk(&mut |pat| {
2811 PatKind::Ident(bmode, ident, ref opt_pat) => {
2812 // First try to resolve the identifier as some existing
2813 // entity, then fall back to a fresh binding.
2814 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS,
2816 .and_then(LexicalScopeBinding::item);
2817 let resolution = binding.map(NameBinding::def).and_then(|def| {
2818 let is_syntactic_ambiguity = opt_pat.is_none() &&
2819 bmode == BindingMode::ByValue(Mutability::Immutable);
2821 Def::StructCtor(_, CtorKind::Const) |
2822 Def::VariantCtor(_, CtorKind::Const) |
2823 Def::Const(..) if is_syntactic_ambiguity => {
2824 // Disambiguate in favor of a unit struct/variant
2825 // or constant pattern.
2826 self.record_use(ident, ValueNS, binding.unwrap(), ident.span);
2827 Some(PathResolution::new(def))
2829 Def::StructCtor(..) | Def::VariantCtor(..) |
2830 Def::Const(..) | Def::Static(..) => {
2831 // This is unambiguously a fresh binding, either syntactically
2832 // (e.g. `IDENT @ PAT` or `ref IDENT`) or because `IDENT` resolves
2833 // to something unusable as a pattern (e.g. constructor function),
2834 // but we still conservatively report an error, see
2835 // issues/33118#issuecomment-233962221 for one reason why.
2839 ResolutionError::BindingShadowsSomethingUnacceptable(
2840 pat_src.descr(), ident.name, binding.unwrap())
2844 Def::Fn(..) | Def::Err => {
2845 // These entities are explicitly allowed
2846 // to be shadowed by fresh bindings.
2850 span_bug!(ident.span, "unexpected definition for an \
2851 identifier in pattern: {:?}", def);
2854 }).unwrap_or_else(|| {
2855 self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings)
2858 self.record_def(pat.id, resolution);
2861 PatKind::TupleStruct(ref path, ..) => {
2862 self.smart_resolve_path(pat.id, None, path, PathSource::TupleStruct);
2865 PatKind::Path(ref qself, ref path) => {
2866 self.smart_resolve_path(pat.id, qself.as_ref(), path, PathSource::Pat);
2869 PatKind::Struct(ref path, ..) => {
2870 self.smart_resolve_path(pat.id, None, path, PathSource::Struct);
2878 visit::walk_pat(self, pat);
2881 // High-level and context dependent path resolution routine.
2882 // Resolves the path and records the resolution into definition map.
2883 // If resolution fails tries several techniques to find likely
2884 // resolution candidates, suggest imports or other help, and report
2885 // errors in user friendly way.
2886 fn smart_resolve_path(&mut self,
2888 qself: Option<&QSelf>,
2892 self.smart_resolve_path_with_crate_lint(id, qself, path, source, CrateLint::SimplePath(id))
2895 /// A variant of `smart_resolve_path` where you also specify extra
2896 /// information about where the path came from; this extra info is
2897 /// sometimes needed for the lint that recommends rewriting
2898 /// absolute paths to `crate`, so that it knows how to frame the
2899 /// suggestion. If you are just resolving a path like `foo::bar`
2900 /// that appears...somewhere, though, then you just want
2901 /// `CrateLint::SimplePath`, which is what `smart_resolve_path`
2902 /// already provides.
2903 fn smart_resolve_path_with_crate_lint(
2906 qself: Option<&QSelf>,
2909 crate_lint: CrateLint
2910 ) -> PathResolution {
2911 let segments = &path.segments.iter()
2912 .map(|seg| seg.ident)
2913 .collect::<Vec<_>>();
2914 self.smart_resolve_path_fragment(id, qself, segments, path.span, source, crate_lint)
2917 fn smart_resolve_path_fragment(&mut self,
2919 qself: Option<&QSelf>,
2923 crate_lint: CrateLint)
2925 let ident_span = path.last().map_or(span, |ident| ident.span);
2926 let ns = source.namespace();
2927 let is_expected = &|def| source.is_expected(def);
2928 let is_enum_variant = &|def| if let Def::Variant(..) = def { true } else { false };
2930 // Base error is amended with one short label and possibly some longer helps/notes.
2931 let report_errors = |this: &mut Self, def: Option<Def>| {
2932 // Make the base error.
2933 let expected = source.descr_expected();
2934 let path_str = names_to_string(path);
2935 let code = source.error_code(def.is_some());
2936 let (base_msg, fallback_label, base_span) = if let Some(def) = def {
2937 (format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str),
2938 format!("not a {}", expected),
2941 let item_str = path[path.len() - 1];
2942 let item_span = path[path.len() - 1].span;
2943 let (mod_prefix, mod_str) = if path.len() == 1 {
2944 (String::new(), "this scope".to_string())
2945 } else if path.len() == 2 && path[0].name == keywords::CrateRoot.name() {
2946 (String::new(), "the crate root".to_string())
2948 let mod_path = &path[..path.len() - 1];
2949 let mod_prefix = match this.resolve_path(None, mod_path, Some(TypeNS),
2950 false, span, CrateLint::No) {
2951 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
2954 }.map_or(String::new(), |def| format!("{} ", def.kind_name()));
2955 (mod_prefix, format!("`{}`", names_to_string(mod_path)))
2957 (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str),
2958 format!("not found in {}", mod_str),
2961 let code = DiagnosticId::Error(code.into());
2962 let mut err = this.session.struct_span_err_with_code(base_span, &base_msg, code);
2964 // Emit special messages for unresolved `Self` and `self`.
2965 if is_self_type(path, ns) {
2966 __diagnostic_used!(E0411);
2967 err.code(DiagnosticId::Error("E0411".into()));
2968 let available_in = if this.session.features_untracked().self_in_typedefs {
2969 "impls, traits, and type definitions"
2973 err.span_label(span, format!("`Self` is only available in {}", available_in));
2974 return (err, Vec::new());
2976 if is_self_value(path, ns) {
2977 __diagnostic_used!(E0424);
2978 err.code(DiagnosticId::Error("E0424".into()));
2979 err.span_label(span, format!("`self` value is only available in \
2980 methods with `self` parameter"));
2981 return (err, Vec::new());
2984 // Try to lookup the name in more relaxed fashion for better error reporting.
2985 let ident = *path.last().unwrap();
2986 let candidates = this.lookup_import_candidates(ident.name, ns, is_expected);
2987 if candidates.is_empty() && is_expected(Def::Enum(DefId::local(CRATE_DEF_INDEX))) {
2988 let enum_candidates =
2989 this.lookup_import_candidates(ident.name, ns, is_enum_variant);
2990 let mut enum_candidates = enum_candidates.iter()
2991 .map(|suggestion| import_candidate_to_paths(&suggestion)).collect::<Vec<_>>();
2992 enum_candidates.sort();
2993 for (sp, variant_path, enum_path) in enum_candidates {
2995 let msg = format!("there is an enum variant `{}`, \
3001 err.span_suggestion(span, "you can try using the variant's enum",
3006 if path.len() == 1 && this.self_type_is_available(span) {
3007 if let Some(candidate) = this.lookup_assoc_candidate(ident, ns, is_expected) {
3008 let self_is_available = this.self_value_is_available(path[0].span, span);
3010 AssocSuggestion::Field => {
3011 err.span_suggestion(span, "try",
3012 format!("self.{}", path_str));
3013 if !self_is_available {
3014 err.span_label(span, format!("`self` value is only available in \
3015 methods with `self` parameter"));
3018 AssocSuggestion::MethodWithSelf if self_is_available => {
3019 err.span_suggestion(span, "try",
3020 format!("self.{}", path_str));
3022 AssocSuggestion::MethodWithSelf | AssocSuggestion::AssocItem => {
3023 err.span_suggestion(span, "try",
3024 format!("Self::{}", path_str));
3027 return (err, candidates);
3031 let mut levenshtein_worked = false;
3034 if let Some(candidate) = this.lookup_typo_candidate(path, ns, is_expected, span) {
3035 err.span_label(ident_span, format!("did you mean `{}`?", candidate));
3036 levenshtein_worked = true;
3039 // Try context dependent help if relaxed lookup didn't work.
3040 if let Some(def) = def {
3041 match (def, source) {
3042 (Def::Macro(..), _) => {
3043 err.span_label(span, format!("did you mean `{}!(...)`?", path_str));
3044 return (err, candidates);
3046 (Def::TyAlias(..), PathSource::Trait(_)) => {
3047 err.span_label(span, "type aliases cannot be used for traits");
3048 return (err, candidates);
3050 (Def::Mod(..), PathSource::Expr(Some(parent))) => match parent.node {
3051 ExprKind::Field(_, ident) => {
3052 err.span_label(parent.span, format!("did you mean `{}::{}`?",
3054 return (err, candidates);
3056 ExprKind::MethodCall(ref segment, ..) => {
3057 err.span_label(parent.span, format!("did you mean `{}::{}(...)`?",
3058 path_str, segment.ident));
3059 return (err, candidates);
3063 (Def::Enum(..), PathSource::TupleStruct)
3064 | (Def::Enum(..), PathSource::Expr(..)) => {
3065 if let Some(variants) = this.collect_enum_variants(def) {
3066 err.note(&format!("did you mean to use one \
3067 of the following variants?\n{}",
3069 .map(|suggestion| path_names_to_string(suggestion))
3070 .map(|suggestion| format!("- `{}`", suggestion))
3071 .collect::<Vec<_>>()
3075 err.note("did you mean to use one of the enum's variants?");
3077 return (err, candidates);
3079 (Def::Struct(def_id), _) if ns == ValueNS => {
3080 if let Some((ctor_def, ctor_vis))
3081 = this.struct_constructors.get(&def_id).cloned() {
3082 let accessible_ctor = this.is_accessible(ctor_vis);
3083 if is_expected(ctor_def) && !accessible_ctor {
3084 err.span_label(span, format!("constructor is not visible \
3085 here due to private fields"));
3088 // HACK(estebank): find a better way to figure out that this was a
3089 // parser issue where a struct literal is being used on an expression
3090 // where a brace being opened means a block is being started. Look
3091 // ahead for the next text to see if `span` is followed by a `{`.
3092 let cm = this.session.source_map();
3095 sp = cm.next_point(sp);
3096 match cm.span_to_snippet(sp) {
3097 Ok(ref snippet) => {
3098 if snippet.chars().any(|c| { !c.is_whitespace() }) {
3105 let followed_by_brace = match cm.span_to_snippet(sp) {
3106 Ok(ref snippet) if snippet == "{" => true,
3109 if let (PathSource::Expr(None), true) = (source, followed_by_brace) {
3112 format!("did you mean `({} {{ /* fields */ }})`?", path_str),
3117 format!("did you mean `{} {{ /* fields */ }}`?", path_str),
3121 return (err, candidates);
3123 (Def::Union(..), _) |
3124 (Def::Variant(..), _) |
3125 (Def::VariantCtor(_, CtorKind::Fictive), _) if ns == ValueNS => {
3126 err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?",
3128 return (err, candidates);
3130 (Def::SelfTy(..), _) if ns == ValueNS => {
3131 err.span_label(span, fallback_label);
3132 err.note("can't use `Self` as a constructor, you must use the \
3133 implemented struct");
3134 return (err, candidates);
3136 (Def::TyAlias(_), _) | (Def::AssociatedTy(..), _) if ns == ValueNS => {
3137 err.note("can't use a type alias as a constructor");
3138 return (err, candidates);
3145 if !levenshtein_worked {
3146 err.span_label(base_span, fallback_label);
3147 this.type_ascription_suggestion(&mut err, base_span);
3151 let report_errors = |this: &mut Self, def: Option<Def>| {
3152 let (err, candidates) = report_errors(this, def);
3153 let def_id = this.current_module.normal_ancestor_id;
3154 let node_id = this.definitions.as_local_node_id(def_id).unwrap();
3155 let better = def.is_some();
3156 this.use_injections.push(UseError { err, candidates, node_id, better });
3157 err_path_resolution()
3160 let resolution = match self.resolve_qpath_anywhere(
3166 source.defer_to_typeck(),
3167 source.global_by_default(),
3170 Some(resolution) if resolution.unresolved_segments() == 0 => {
3171 if is_expected(resolution.base_def()) || resolution.base_def() == Def::Err {
3174 // Add a temporary hack to smooth the transition to new struct ctor
3175 // visibility rules. See #38932 for more details.
3177 if let Def::Struct(def_id) = resolution.base_def() {
3178 if let Some((ctor_def, ctor_vis))
3179 = self.struct_constructors.get(&def_id).cloned() {
3180 if is_expected(ctor_def) && self.is_accessible(ctor_vis) {
3181 let lint = lint::builtin::LEGACY_CONSTRUCTOR_VISIBILITY;
3182 self.session.buffer_lint(lint, id, span,
3183 "private struct constructors are not usable through \
3184 re-exports in outer modules",
3186 res = Some(PathResolution::new(ctor_def));
3191 res.unwrap_or_else(|| report_errors(self, Some(resolution.base_def())))
3194 Some(resolution) if source.defer_to_typeck() => {
3195 // Not fully resolved associated item `T::A::B` or `<T as Tr>::A::B`
3196 // or `<T>::A::B`. If `B` should be resolved in value namespace then
3197 // it needs to be added to the trait map.
3199 let item_name = *path.last().unwrap();
3200 let traits = self.get_traits_containing_item(item_name, ns);
3201 self.trait_map.insert(id, traits);
3205 _ => report_errors(self, None)
3208 if let PathSource::TraitItem(..) = source {} else {
3209 // Avoid recording definition of `A::B` in `<T as A>::B::C`.
3210 self.record_def(id, resolution);
3215 fn type_ascription_suggestion(&self,
3216 err: &mut DiagnosticBuilder,
3218 debug!("type_ascription_suggetion {:?}", base_span);
3219 let cm = self.session.source_map();
3220 debug!("self.current_type_ascription {:?}", self.current_type_ascription);
3221 if let Some(sp) = self.current_type_ascription.last() {
3223 loop { // try to find the `:`, bail on first non-':'/non-whitespace
3224 sp = cm.next_point(sp);
3225 if let Ok(snippet) = cm.span_to_snippet(sp.to(cm.next_point(sp))) {
3226 debug!("snippet {:?}", snippet);
3227 let line_sp = cm.lookup_char_pos(sp.hi()).line;
3228 let line_base_sp = cm.lookup_char_pos(base_span.lo()).line;
3229 debug!("{:?} {:?}", line_sp, line_base_sp);
3231 err.span_label(base_span,
3232 "expecting a type here because of type ascription");
3233 if line_sp != line_base_sp {
3234 err.span_suggestion_short(sp,
3235 "did you mean to use `;` here instead?",
3239 } else if snippet.trim().len() != 0 {
3240 debug!("tried to find type ascription `:` token, couldn't find it");
3250 fn self_type_is_available(&mut self, span: Span) -> bool {
3251 let binding = self.resolve_ident_in_lexical_scope(keywords::SelfType.ident(),
3252 TypeNS, None, span);
3253 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
3256 fn self_value_is_available(&mut self, self_span: Span, path_span: Span) -> bool {
3257 let ident = Ident::new(keywords::SelfValue.name(), self_span);
3258 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, None, path_span);
3259 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
3262 // Resolve in alternative namespaces if resolution in the primary namespace fails.
3263 fn resolve_qpath_anywhere(&mut self,
3265 qself: Option<&QSelf>,
3267 primary_ns: Namespace,
3269 defer_to_typeck: bool,
3270 global_by_default: bool,
3271 crate_lint: CrateLint)
3272 -> Option<PathResolution> {
3273 let mut fin_res = None;
3274 // FIXME: can't resolve paths in macro namespace yet, macros are
3275 // processed by the little special hack below.
3276 for (i, ns) in [primary_ns, TypeNS, ValueNS, /*MacroNS*/].iter().cloned().enumerate() {
3277 if i == 0 || ns != primary_ns {
3278 match self.resolve_qpath(id, qself, path, ns, span, global_by_default, crate_lint) {
3279 // If defer_to_typeck, then resolution > no resolution,
3280 // otherwise full resolution > partial resolution > no resolution.
3281 Some(res) if res.unresolved_segments() == 0 || defer_to_typeck =>
3283 res => if fin_res.is_none() { fin_res = res },
3287 let is_global = self.macro_prelude.get(&path[0].name).cloned()
3288 .map(|binding| binding.get_macro(self).kind() == MacroKind::Bang).unwrap_or(false);
3289 if primary_ns != MacroNS && (is_global ||
3290 self.macro_names.contains(&path[0].modern())) {
3291 // Return some dummy definition, it's enough for error reporting.
3293 PathResolution::new(Def::Macro(DefId::local(CRATE_DEF_INDEX), MacroKind::Bang))
3299 /// Handles paths that may refer to associated items.
3300 fn resolve_qpath(&mut self,
3302 qself: Option<&QSelf>,
3306 global_by_default: bool,
3307 crate_lint: CrateLint)
3308 -> Option<PathResolution> {
3310 "resolve_qpath(id={:?}, qself={:?}, path={:?}, \
3311 ns={:?}, span={:?}, global_by_default={:?})",
3320 if let Some(qself) = qself {
3321 if qself.position == 0 {
3322 // This is a case like `<T>::B`, where there is no
3323 // trait to resolve. In that case, we leave the `B`
3324 // segment to be resolved by type-check.
3325 return Some(PathResolution::with_unresolved_segments(
3326 Def::Mod(DefId::local(CRATE_DEF_INDEX)), path.len()
3330 // Make sure `A::B` in `<T as A::B>::C` is a trait item.
3332 // Currently, `path` names the full item (`A::B::C`, in
3333 // our example). so we extract the prefix of that that is
3334 // the trait (the slice upto and including
3335 // `qself.position`). And then we recursively resolve that,
3336 // but with `qself` set to `None`.
3338 // However, setting `qself` to none (but not changing the
3339 // span) loses the information about where this path
3340 // *actually* appears, so for the purposes of the crate
3341 // lint we pass along information that this is the trait
3342 // name from a fully qualified path, and this also
3343 // contains the full span (the `CrateLint::QPathTrait`).
3344 let ns = if qself.position + 1 == path.len() { ns } else { TypeNS };
3345 let res = self.smart_resolve_path_fragment(
3348 &path[..qself.position + 1],
3350 PathSource::TraitItem(ns),
3351 CrateLint::QPathTrait {
3353 qpath_span: qself.path_span,
3357 // The remaining segments (the `C` in our example) will
3358 // have to be resolved by type-check, since that requires doing
3359 // trait resolution.
3360 return Some(PathResolution::with_unresolved_segments(
3361 res.base_def(), res.unresolved_segments() + path.len() - qself.position - 1
3365 let result = match self.resolve_path(
3373 PathResult::NonModule(path_res) => path_res,
3374 PathResult::Module(ModuleOrUniformRoot::Module(module)) if !module.is_normal() => {
3375 PathResolution::new(module.def().unwrap())
3377 // In `a(::assoc_item)*` `a` cannot be a module. If `a` does resolve to a module we
3378 // don't report an error right away, but try to fallback to a primitive type.
3379 // So, we are still able to successfully resolve something like
3381 // use std::u8; // bring module u8 in scope
3382 // fn f() -> u8 { // OK, resolves to primitive u8, not to std::u8
3383 // u8::max_value() // OK, resolves to associated function <u8>::max_value,
3384 // // not to non-existent std::u8::max_value
3387 // Such behavior is required for backward compatibility.
3388 // The same fallback is used when `a` resolves to nothing.
3389 PathResult::Module(ModuleOrUniformRoot::Module(_)) |
3390 PathResult::Failed(..)
3391 if (ns == TypeNS || path.len() > 1) &&
3392 self.primitive_type_table.primitive_types
3393 .contains_key(&path[0].name) => {
3394 let prim = self.primitive_type_table.primitive_types[&path[0].name];
3395 PathResolution::with_unresolved_segments(Def::PrimTy(prim), path.len() - 1)
3397 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
3398 PathResolution::new(module.def().unwrap()),
3399 PathResult::Failed(span, msg, false) => {
3400 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
3401 err_path_resolution()
3403 PathResult::Module(ModuleOrUniformRoot::UniformRoot(_)) |
3404 PathResult::Failed(..) => return None,
3405 PathResult::Indeterminate => bug!("indetermined path result in resolve_qpath"),
3408 if path.len() > 1 && !global_by_default && result.base_def() != Def::Err &&
3409 path[0].name != keywords::CrateRoot.name() &&
3410 path[0].name != keywords::DollarCrate.name() {
3411 let unqualified_result = {
3412 match self.resolve_path(
3414 &[*path.last().unwrap()],
3420 PathResult::NonModule(path_res) => path_res.base_def(),
3421 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
3422 module.def().unwrap(),
3423 _ => return Some(result),
3426 if result.base_def() == unqualified_result {
3427 let lint = lint::builtin::UNUSED_QUALIFICATIONS;
3428 self.session.buffer_lint(lint, id, span, "unnecessary qualification")
3437 base_module: Option<ModuleOrUniformRoot<'a>>,
3439 opt_ns: Option<Namespace>, // `None` indicates a module path
3442 crate_lint: CrateLint,
3443 ) -> PathResult<'a> {
3444 let mut module = base_module;
3445 let mut allow_super = true;
3446 let mut second_binding = None;
3449 "resolve_path(path={:?}, opt_ns={:?}, record_used={:?}, \
3450 path_span={:?}, crate_lint={:?})",
3458 for (i, &ident) in path.iter().enumerate() {
3459 debug!("resolve_path ident {} {:?}", i, ident);
3460 let is_last = i == path.len() - 1;
3461 let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
3462 let name = ident.name;
3464 allow_super &= ns == TypeNS &&
3465 (name == keywords::SelfValue.name() ||
3466 name == keywords::Super.name());
3469 if allow_super && name == keywords::Super.name() {
3470 let mut ctxt = ident.span.ctxt().modern();
3471 let self_module = match i {
3472 0 => Some(self.resolve_self(&mut ctxt, self.current_module)),
3474 Some(ModuleOrUniformRoot::Module(module)) => Some(module),
3478 if let Some(self_module) = self_module {
3479 if let Some(parent) = self_module.parent {
3480 module = Some(ModuleOrUniformRoot::Module(
3481 self.resolve_self(&mut ctxt, parent)));
3485 let msg = "There are too many initial `super`s.".to_string();
3486 return PathResult::Failed(ident.span, msg, false);
3489 if name == keywords::SelfValue.name() {
3490 let mut ctxt = ident.span.ctxt().modern();
3491 module = Some(ModuleOrUniformRoot::Module(
3492 self.resolve_self(&mut ctxt, self.current_module)));
3495 if name == keywords::Extern.name() ||
3496 name == keywords::CrateRoot.name() &&
3497 self.session.features_untracked().extern_absolute_paths &&
3498 self.session.rust_2018() {
3499 module = Some(ModuleOrUniformRoot::UniformRoot(name));
3502 if name == keywords::CrateRoot.name() ||
3503 name == keywords::Crate.name() ||
3504 name == keywords::DollarCrate.name() {
3505 // `::a::b`, `crate::a::b` or `$crate::a::b`
3506 module = Some(ModuleOrUniformRoot::Module(
3507 self.resolve_crate_root(ident)));
3513 // Report special messages for path segment keywords in wrong positions.
3514 if ident.is_path_segment_keyword() && i != 0 {
3515 let name_str = if name == keywords::CrateRoot.name() {
3516 "crate root".to_string()
3518 format!("`{}`", name)
3520 let msg = if i == 1 && path[0].name == keywords::CrateRoot.name() {
3521 format!("global paths cannot start with {}", name_str)
3523 format!("{} in paths can only be used in start position", name_str)
3525 return PathResult::Failed(ident.span, msg, false);
3528 let binding = if let Some(module) = module {
3529 self.resolve_ident_in_module(module, ident, ns, record_used, path_span)
3530 } else if opt_ns == Some(MacroNS) {
3531 assert!(ns == TypeNS);
3532 self.resolve_lexical_macro_path_segment(ident, ns, record_used, record_used,
3533 false, path_span).map(|(b, _)| b)
3535 let record_used_id =
3536 if record_used { crate_lint.node_id().or(Some(CRATE_NODE_ID)) } else { None };
3537 match self.resolve_ident_in_lexical_scope(ident, ns, record_used_id, path_span) {
3538 // we found a locally-imported or available item/module
3539 Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
3540 // we found a local variable or type param
3541 Some(LexicalScopeBinding::Def(def))
3542 if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) => {
3543 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3547 _ => Err(if record_used { Determined } else { Undetermined }),
3554 second_binding = Some(binding);
3556 let def = binding.def();
3557 let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(def);
3558 if let Some(next_module) = binding.module() {
3559 module = Some(ModuleOrUniformRoot::Module(next_module));
3560 } else if def == Def::ToolMod && i + 1 != path.len() {
3561 let def = Def::NonMacroAttr(NonMacroAttrKind::Tool);
3562 return PathResult::NonModule(PathResolution::new(def));
3563 } else if def == Def::Err {
3564 return PathResult::NonModule(err_path_resolution());
3565 } else if opt_ns.is_some() && (is_last || maybe_assoc) {
3566 self.lint_if_path_starts_with_module(
3572 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3573 def, path.len() - i - 1
3576 return PathResult::Failed(ident.span,
3577 format!("Not a module `{}`", ident),
3581 Err(Undetermined) => return PathResult::Indeterminate,
3582 Err(Determined) => {
3583 if let Some(ModuleOrUniformRoot::Module(module)) = module {
3584 if opt_ns.is_some() && !module.is_normal() {
3585 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3586 module.def().unwrap(), path.len() - i
3590 let module_def = match module {
3591 Some(ModuleOrUniformRoot::Module(module)) => module.def(),
3594 let msg = if module_def == self.graph_root.def() {
3595 let is_mod = |def| match def { Def::Mod(..) => true, _ => false };
3596 let mut candidates =
3597 self.lookup_import_candidates(name, TypeNS, is_mod);
3598 candidates.sort_by_cached_key(|c| {
3599 (c.path.segments.len(), c.path.to_string())
3601 if let Some(candidate) = candidates.get(0) {
3602 format!("Did you mean `{}`?", candidate.path)
3604 format!("Maybe a missing `extern crate {};`?", ident)
3607 format!("Use of undeclared type or module `{}`", ident)
3609 format!("Could not find `{}` in `{}`", ident, path[i - 1])
3611 return PathResult::Failed(ident.span, msg, is_last);
3616 self.lint_if_path_starts_with_module(crate_lint, path, path_span, second_binding);
3618 PathResult::Module(module.unwrap_or_else(|| {
3619 span_bug!(path_span, "resolve_path: empty(?) path {:?} has no module", path);
3624 fn lint_if_path_starts_with_module(
3626 crate_lint: CrateLint,
3629 second_binding: Option<&NameBinding>,
3631 // In the 2018 edition this lint is a hard error, so nothing to do
3632 if self.session.rust_2018() {
3636 // In the 2015 edition there's no use in emitting lints unless the
3637 // crate's already enabled the feature that we're going to suggest
3638 if !self.session.features_untracked().crate_in_paths {
3642 let (diag_id, diag_span) = match crate_lint {
3643 CrateLint::No => return,
3644 CrateLint::SimplePath(id) => (id, path_span),
3645 CrateLint::UsePath { root_id, root_span } => (root_id, root_span),
3646 CrateLint::QPathTrait { qpath_id, qpath_span } => (qpath_id, qpath_span),
3649 let first_name = match path.get(0) {
3650 Some(ident) => ident.name,
3654 // We're only interested in `use` paths which should start with
3655 // `{{root}}` or `extern` currently.
3656 if first_name != keywords::Extern.name() && first_name != keywords::CrateRoot.name() {
3661 // If this import looks like `crate::...` it's already good
3662 Some(ident) if ident.name == keywords::Crate.name() => return,
3663 // Otherwise go below to see if it's an extern crate
3665 // If the path has length one (and it's `CrateRoot` most likely)
3666 // then we don't know whether we're gonna be importing a crate or an
3667 // item in our crate. Defer this lint to elsewhere
3671 // If the first element of our path was actually resolved to an
3672 // `ExternCrate` (also used for `crate::...`) then no need to issue a
3673 // warning, this looks all good!
3674 if let Some(binding) = second_binding {
3675 if let NameBindingKind::Import { directive: d, .. } = binding.kind {
3676 // Careful: we still want to rewrite paths from
3677 // renamed extern crates.
3678 if let ImportDirectiveSubclass::ExternCrate(None) = d.subclass {
3684 let diag = lint::builtin::BuiltinLintDiagnostics
3685 ::AbsPathWithModule(diag_span);
3686 self.session.buffer_lint_with_diagnostic(
3687 lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
3689 "absolute paths must start with `self`, `super`, \
3690 `crate`, or an external crate name in the 2018 edition",
3694 // Resolve a local definition, potentially adjusting for closures.
3695 fn adjust_local_def(&mut self,
3700 span: Span) -> Def {
3701 let ribs = &self.ribs[ns][rib_index + 1..];
3703 // An invalid forward use of a type parameter from a previous default.
3704 if let ForwardTyParamBanRibKind = self.ribs[ns][rib_index].kind {
3706 resolve_error(self, span, ResolutionError::ForwardDeclaredTyParam);
3708 assert_eq!(def, Def::Err);
3714 span_bug!(span, "unexpected {:?} in bindings", def)
3716 Def::Local(node_id) => {
3719 NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) |
3720 ForwardTyParamBanRibKind => {
3721 // Nothing to do. Continue.
3723 ClosureRibKind(function_id) => {
3726 let seen = self.freevars_seen
3729 if let Some(&index) = seen.get(&node_id) {
3730 def = Def::Upvar(node_id, index, function_id);
3733 let vec = self.freevars
3736 let depth = vec.len();
3737 def = Def::Upvar(node_id, depth, function_id);
3744 seen.insert(node_id, depth);
3747 ItemRibKind | TraitOrImplItemRibKind => {
3748 // This was an attempt to access an upvar inside a
3749 // named function item. This is not allowed, so we
3752 resolve_error(self, span,
3753 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
3757 ConstantItemRibKind => {
3758 // Still doesn't deal with upvars
3760 resolve_error(self, span,
3761 ResolutionError::AttemptToUseNonConstantValueInConstant);
3768 Def::TyParam(..) | Def::SelfTy(..) => {
3771 NormalRibKind | TraitOrImplItemRibKind | ClosureRibKind(..) |
3772 ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind |
3773 ConstantItemRibKind => {
3774 // Nothing to do. Continue.
3777 // This was an attempt to use a type parameter outside
3780 resolve_error(self, span,
3781 ResolutionError::TypeParametersFromOuterFunction(def));
3793 fn lookup_assoc_candidate<FilterFn>(&mut self,
3796 filter_fn: FilterFn)
3797 -> Option<AssocSuggestion>
3798 where FilterFn: Fn(Def) -> bool
3800 fn extract_node_id(t: &Ty) -> Option<NodeId> {
3802 TyKind::Path(None, _) => Some(t.id),
3803 TyKind::Rptr(_, ref mut_ty) => extract_node_id(&mut_ty.ty),
3804 // This doesn't handle the remaining `Ty` variants as they are not
3805 // that commonly the self_type, it might be interesting to provide
3806 // support for those in future.
3811 // Fields are generally expected in the same contexts as locals.
3812 if filter_fn(Def::Local(ast::DUMMY_NODE_ID)) {
3813 if let Some(node_id) = self.current_self_type.as_ref().and_then(extract_node_id) {
3814 // Look for a field with the same name in the current self_type.
3815 if let Some(resolution) = self.def_map.get(&node_id) {
3816 match resolution.base_def() {
3817 Def::Struct(did) | Def::Union(did)
3818 if resolution.unresolved_segments() == 0 => {
3819 if let Some(field_names) = self.field_names.get(&did) {
3820 if field_names.iter().any(|&field_name| ident.name == field_name) {
3821 return Some(AssocSuggestion::Field);
3831 // Look for associated items in the current trait.
3832 if let Some((module, _)) = self.current_trait_ref {
3833 if let Ok(binding) = self.resolve_ident_in_module(
3834 ModuleOrUniformRoot::Module(module),
3840 let def = binding.def();
3842 return Some(if self.has_self.contains(&def.def_id()) {
3843 AssocSuggestion::MethodWithSelf
3845 AssocSuggestion::AssocItem
3854 fn lookup_typo_candidate<FilterFn>(&mut self,
3857 filter_fn: FilterFn,
3860 where FilterFn: Fn(Def) -> bool
3862 let add_module_candidates = |module: Module, names: &mut Vec<Name>| {
3863 for (&(ident, _), resolution) in module.resolutions.borrow().iter() {
3864 if let Some(binding) = resolution.borrow().binding {
3865 if filter_fn(binding.def()) {
3866 names.push(ident.name);
3872 let mut names = Vec::new();
3873 if path.len() == 1 {
3874 // Search in lexical scope.
3875 // Walk backwards up the ribs in scope and collect candidates.
3876 for rib in self.ribs[ns].iter().rev() {
3877 // Locals and type parameters
3878 for (ident, def) in &rib.bindings {
3879 if filter_fn(*def) {
3880 names.push(ident.name);
3884 if let ModuleRibKind(module) = rib.kind {
3885 // Items from this module
3886 add_module_candidates(module, &mut names);
3888 if let ModuleKind::Block(..) = module.kind {
3889 // We can see through blocks
3891 // Items from the prelude
3892 if !module.no_implicit_prelude {
3893 names.extend(self.extern_prelude.iter().cloned());
3894 if let Some(prelude) = self.prelude {
3895 add_module_candidates(prelude, &mut names);
3902 // Add primitive types to the mix
3903 if filter_fn(Def::PrimTy(Bool)) {
3905 self.primitive_type_table.primitive_types.iter().map(|(name, _)| name)
3909 // Search in module.
3910 let mod_path = &path[..path.len() - 1];
3911 if let PathResult::Module(module) = self.resolve_path(None, mod_path, Some(TypeNS),
3912 false, span, CrateLint::No) {
3913 if let ModuleOrUniformRoot::Module(module) = module {
3914 add_module_candidates(module, &mut names);
3919 let name = path[path.len() - 1].name;
3920 // Make sure error reporting is deterministic.
3921 names.sort_by_cached_key(|name| name.as_str());
3922 match find_best_match_for_name(names.iter(), &name.as_str(), None) {
3923 Some(found) if found != name => Some(found),
3928 fn with_resolved_label<F>(&mut self, label: Option<Label>, id: NodeId, f: F)
3929 where F: FnOnce(&mut Resolver)
3931 if let Some(label) = label {
3932 self.unused_labels.insert(id, label.ident.span);
3933 let def = Def::Label(id);
3934 self.with_label_rib(|this| {
3935 let ident = label.ident.modern_and_legacy();
3936 this.label_ribs.last_mut().unwrap().bindings.insert(ident, def);
3944 fn resolve_labeled_block(&mut self, label: Option<Label>, id: NodeId, block: &Block) {
3945 self.with_resolved_label(label, id, |this| this.visit_block(block));
3948 fn resolve_expr(&mut self, expr: &Expr, parent: Option<&Expr>) {
3949 // First, record candidate traits for this expression if it could
3950 // result in the invocation of a method call.
3952 self.record_candidate_traits_for_expr_if_necessary(expr);
3954 // Next, resolve the node.
3956 ExprKind::Path(ref qself, ref path) => {
3957 self.smart_resolve_path(expr.id, qself.as_ref(), path, PathSource::Expr(parent));
3958 visit::walk_expr(self, expr);
3961 ExprKind::Struct(ref path, ..) => {
3962 self.smart_resolve_path(expr.id, None, path, PathSource::Struct);
3963 visit::walk_expr(self, expr);
3966 ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => {
3967 let def = self.search_label(label.ident, |rib, ident| {
3968 rib.bindings.get(&ident.modern_and_legacy()).cloned()
3972 // Search again for close matches...
3973 // Picks the first label that is "close enough", which is not necessarily
3974 // the closest match
3975 let close_match = self.search_label(label.ident, |rib, ident| {
3976 let names = rib.bindings.iter().map(|(id, _)| &id.name);
3977 find_best_match_for_name(names, &*ident.as_str(), None)
3979 self.record_def(expr.id, err_path_resolution());
3982 ResolutionError::UndeclaredLabel(&label.ident.as_str(),
3985 Some(Def::Label(id)) => {
3986 // Since this def is a label, it is never read.
3987 self.record_def(expr.id, PathResolution::new(Def::Label(id)));
3988 self.unused_labels.remove(&id);
3991 span_bug!(expr.span, "label wasn't mapped to a label def!");
3995 // visit `break` argument if any
3996 visit::walk_expr(self, expr);
3999 ExprKind::IfLet(ref pats, ref subexpression, ref if_block, ref optional_else) => {
4000 self.visit_expr(subexpression);
4002 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
4003 let mut bindings_list = FxHashMap();
4005 self.resolve_pattern(pat, PatternSource::IfLet, &mut bindings_list);
4007 // This has to happen *after* we determine which pat_idents are variants
4008 self.check_consistent_bindings(pats);
4009 self.visit_block(if_block);
4010 self.ribs[ValueNS].pop();
4012 optional_else.as_ref().map(|expr| self.visit_expr(expr));
4015 ExprKind::Loop(ref block, label) => self.resolve_labeled_block(label, expr.id, &block),
4017 ExprKind::While(ref subexpression, ref block, label) => {
4018 self.with_resolved_label(label, expr.id, |this| {
4019 this.visit_expr(subexpression);
4020 this.visit_block(block);
4024 ExprKind::WhileLet(ref pats, ref subexpression, ref block, label) => {
4025 self.with_resolved_label(label, expr.id, |this| {
4026 this.visit_expr(subexpression);
4027 this.ribs[ValueNS].push(Rib::new(NormalRibKind));
4028 let mut bindings_list = FxHashMap();
4030 this.resolve_pattern(pat, PatternSource::WhileLet, &mut bindings_list);
4032 // This has to happen *after* we determine which pat_idents are variants
4033 this.check_consistent_bindings(pats);
4034 this.visit_block(block);
4035 this.ribs[ValueNS].pop();
4039 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, label) => {
4040 self.visit_expr(subexpression);
4041 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
4042 self.resolve_pattern(pattern, PatternSource::For, &mut FxHashMap());
4044 self.resolve_labeled_block(label, expr.id, block);
4046 self.ribs[ValueNS].pop();
4049 ExprKind::Block(ref block, label) => self.resolve_labeled_block(label, block.id, block),
4051 // Equivalent to `visit::walk_expr` + passing some context to children.
4052 ExprKind::Field(ref subexpression, _) => {
4053 self.resolve_expr(subexpression, Some(expr));
4055 ExprKind::MethodCall(ref segment, ref arguments) => {
4056 let mut arguments = arguments.iter();
4057 self.resolve_expr(arguments.next().unwrap(), Some(expr));
4058 for argument in arguments {
4059 self.resolve_expr(argument, None);
4061 self.visit_path_segment(expr.span, segment);
4064 ExprKind::Call(ref callee, ref arguments) => {
4065 self.resolve_expr(callee, Some(expr));
4066 for argument in arguments {
4067 self.resolve_expr(argument, None);
4070 ExprKind::Type(ref type_expr, _) => {
4071 self.current_type_ascription.push(type_expr.span);
4072 visit::walk_expr(self, expr);
4073 self.current_type_ascription.pop();
4075 // Resolve the body of async exprs inside the async closure to which they desugar
4076 ExprKind::Async(_, async_closure_id, ref block) => {
4077 let rib_kind = ClosureRibKind(async_closure_id);
4078 self.ribs[ValueNS].push(Rib::new(rib_kind));
4079 self.label_ribs.push(Rib::new(rib_kind));
4080 self.visit_block(&block);
4081 self.label_ribs.pop();
4082 self.ribs[ValueNS].pop();
4084 // `async |x| ...` gets desugared to `|x| future_from_generator(|| ...)`, so we need to
4085 // resolve the arguments within the proper scopes so that usages of them inside the
4086 // closure are detected as upvars rather than normal closure arg usages.
4088 _, IsAsync::Async { closure_id: inner_closure_id, .. }, _,
4089 ref fn_decl, ref body, _span,
4091 let rib_kind = ClosureRibKind(expr.id);
4092 self.ribs[ValueNS].push(Rib::new(rib_kind));
4093 self.label_ribs.push(Rib::new(rib_kind));
4094 // Resolve arguments:
4095 let mut bindings_list = FxHashMap();
4096 for argument in &fn_decl.inputs {
4097 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
4098 self.visit_ty(&argument.ty);
4100 // No need to resolve return type-- the outer closure return type is
4101 // FunctionRetTy::Default
4103 // Now resolve the inner closure
4105 let rib_kind = ClosureRibKind(inner_closure_id);
4106 self.ribs[ValueNS].push(Rib::new(rib_kind));
4107 self.label_ribs.push(Rib::new(rib_kind));
4108 // No need to resolve arguments: the inner closure has none.
4109 // Resolve the return type:
4110 visit::walk_fn_ret_ty(self, &fn_decl.output);
4112 self.visit_expr(body);
4113 self.label_ribs.pop();
4114 self.ribs[ValueNS].pop();
4116 self.label_ribs.pop();
4117 self.ribs[ValueNS].pop();
4120 visit::walk_expr(self, expr);
4125 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
4127 ExprKind::Field(_, ident) => {
4128 // FIXME(#6890): Even though you can't treat a method like a
4129 // field, we need to add any trait methods we find that match
4130 // the field name so that we can do some nice error reporting
4131 // later on in typeck.
4132 let traits = self.get_traits_containing_item(ident, ValueNS);
4133 self.trait_map.insert(expr.id, traits);
4135 ExprKind::MethodCall(ref segment, ..) => {
4136 debug!("(recording candidate traits for expr) recording traits for {}",
4138 let traits = self.get_traits_containing_item(segment.ident, ValueNS);
4139 self.trait_map.insert(expr.id, traits);
4147 fn get_traits_containing_item(&mut self, mut ident: Ident, ns: Namespace)
4148 -> Vec<TraitCandidate> {
4149 debug!("(getting traits containing item) looking for '{}'", ident.name);
4151 let mut found_traits = Vec::new();
4152 // Look for the current trait.
4153 if let Some((module, _)) = self.current_trait_ref {
4154 if self.resolve_ident_in_module(
4155 ModuleOrUniformRoot::Module(module),
4161 let def_id = module.def_id().unwrap();
4162 found_traits.push(TraitCandidate { def_id: def_id, import_id: None });
4166 ident.span = ident.span.modern();
4167 let mut search_module = self.current_module;
4169 self.get_traits_in_module_containing_item(ident, ns, search_module, &mut found_traits);
4170 search_module = unwrap_or!(
4171 self.hygienic_lexical_parent(search_module, &mut ident.span), break
4175 if let Some(prelude) = self.prelude {
4176 if !search_module.no_implicit_prelude {
4177 self.get_traits_in_module_containing_item(ident, ns, prelude, &mut found_traits);
4184 fn get_traits_in_module_containing_item(&mut self,
4188 found_traits: &mut Vec<TraitCandidate>) {
4189 assert!(ns == TypeNS || ns == ValueNS);
4190 let mut traits = module.traits.borrow_mut();
4191 if traits.is_none() {
4192 let mut collected_traits = Vec::new();
4193 module.for_each_child(|name, ns, binding| {
4194 if ns != TypeNS { return }
4195 if let Def::Trait(_) = binding.def() {
4196 collected_traits.push((name, binding));
4199 *traits = Some(collected_traits.into_boxed_slice());
4202 for &(trait_name, binding) in traits.as_ref().unwrap().iter() {
4203 let module = binding.module().unwrap();
4204 let mut ident = ident;
4205 if ident.span.glob_adjust(module.expansion, binding.span.ctxt().modern()).is_none() {
4208 if self.resolve_ident_in_module_unadjusted(
4209 ModuleOrUniformRoot::Module(module),
4216 let import_id = match binding.kind {
4217 NameBindingKind::Import { directive, .. } => {
4218 self.maybe_unused_trait_imports.insert(directive.id);
4219 self.add_to_glob_map(directive.id, trait_name);
4224 let trait_def_id = module.def_id().unwrap();
4225 found_traits.push(TraitCandidate { def_id: trait_def_id, import_id: import_id });
4230 /// When name resolution fails, this method can be used to look up candidate
4231 /// entities with the expected name. It allows filtering them using the
4232 /// supplied predicate (which should be used to only accept the types of
4233 /// definitions expected e.g. traits). The lookup spans across all crates.
4235 /// NOTE: The method does not look into imports, but this is not a problem,
4236 /// since we report the definitions (thus, the de-aliased imports).
4237 fn lookup_import_candidates<FilterFn>(&mut self,
4239 namespace: Namespace,
4240 filter_fn: FilterFn)
4241 -> Vec<ImportSuggestion>
4242 where FilterFn: Fn(Def) -> bool
4244 let mut candidates = Vec::new();
4245 let mut worklist = Vec::new();
4246 let mut seen_modules = FxHashSet();
4247 worklist.push((self.graph_root, Vec::new(), false));
4249 while let Some((in_module,
4251 in_module_is_extern)) = worklist.pop() {
4252 self.populate_module_if_necessary(in_module);
4254 // We have to visit module children in deterministic order to avoid
4255 // instabilities in reported imports (#43552).
4256 in_module.for_each_child_stable(|ident, ns, name_binding| {
4257 // avoid imports entirely
4258 if name_binding.is_import() && !name_binding.is_extern_crate() { return; }
4259 // avoid non-importable candidates as well
4260 if !name_binding.is_importable() { return; }
4262 // collect results based on the filter function
4263 if ident.name == lookup_name && ns == namespace {
4264 if filter_fn(name_binding.def()) {
4266 let mut segms = if self.session.rust_2018() && !in_module_is_extern {
4267 // crate-local absolute paths start with `crate::` in edition 2018
4268 // FIXME: may also be stabilized for Rust 2015 (Issues #45477, #44660)
4269 let mut full_segms = vec![
4270 ast::PathSegment::from_ident(keywords::Crate.ident())
4272 full_segms.extend(path_segments.clone());
4275 path_segments.clone()
4278 segms.push(ast::PathSegment::from_ident(ident));
4280 span: name_binding.span,
4283 // the entity is accessible in the following cases:
4284 // 1. if it's defined in the same crate, it's always
4285 // accessible (since private entities can be made public)
4286 // 2. if it's defined in another crate, it's accessible
4287 // only if both the module is public and the entity is
4288 // declared as public (due to pruning, we don't explore
4289 // outside crate private modules => no need to check this)
4290 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
4291 candidates.push(ImportSuggestion { path: path });
4296 // collect submodules to explore
4297 if let Some(module) = name_binding.module() {
4299 let mut path_segments = path_segments.clone();
4300 path_segments.push(ast::PathSegment::from_ident(ident));
4302 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
4303 // add the module to the lookup
4304 let is_extern = in_module_is_extern || name_binding.is_extern_crate();
4305 if seen_modules.insert(module.def_id().unwrap()) {
4306 worklist.push((module, path_segments, is_extern));
4316 fn find_module(&mut self,
4318 -> Option<(Module<'a>, ImportSuggestion)>
4320 let mut result = None;
4321 let mut worklist = Vec::new();
4322 let mut seen_modules = FxHashSet();
4323 worklist.push((self.graph_root, Vec::new()));
4325 while let Some((in_module, path_segments)) = worklist.pop() {
4326 // abort if the module is already found
4327 if result.is_some() { break; }
4329 self.populate_module_if_necessary(in_module);
4331 in_module.for_each_child_stable(|ident, _, name_binding| {
4332 // abort if the module is already found or if name_binding is private external
4333 if result.is_some() || !name_binding.vis.is_visible_locally() {
4336 if let Some(module) = name_binding.module() {
4338 let mut path_segments = path_segments.clone();
4339 path_segments.push(ast::PathSegment::from_ident(ident));
4340 if module.def() == Some(module_def) {
4342 span: name_binding.span,
4343 segments: path_segments,
4345 result = Some((module, ImportSuggestion { path: path }));
4347 // add the module to the lookup
4348 if seen_modules.insert(module.def_id().unwrap()) {
4349 worklist.push((module, path_segments));
4359 fn collect_enum_variants(&mut self, enum_def: Def) -> Option<Vec<Path>> {
4360 if let Def::Enum(..) = enum_def {} else {
4361 panic!("Non-enum def passed to collect_enum_variants: {:?}", enum_def)
4364 self.find_module(enum_def).map(|(enum_module, enum_import_suggestion)| {
4365 self.populate_module_if_necessary(enum_module);
4367 let mut variants = Vec::new();
4368 enum_module.for_each_child_stable(|ident, _, name_binding| {
4369 if let Def::Variant(..) = name_binding.def() {
4370 let mut segms = enum_import_suggestion.path.segments.clone();
4371 segms.push(ast::PathSegment::from_ident(ident));
4372 variants.push(Path {
4373 span: name_binding.span,
4382 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
4383 debug!("(recording def) recording {:?} for {}", resolution, node_id);
4384 if let Some(prev_res) = self.def_map.insert(node_id, resolution) {
4385 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
4389 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
4391 ast::VisibilityKind::Public => ty::Visibility::Public,
4392 ast::VisibilityKind::Crate(..) => {
4393 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
4395 ast::VisibilityKind::Inherited => {
4396 ty::Visibility::Restricted(self.current_module.normal_ancestor_id)
4398 ast::VisibilityKind::Restricted { ref path, id, .. } => {
4399 // Visibilities are resolved as global by default, add starting root segment.
4400 let segments = path.make_root().iter().chain(path.segments.iter())
4401 .map(|seg| seg.ident)
4402 .collect::<Vec<_>>();
4403 let def = self.smart_resolve_path_fragment(
4408 PathSource::Visibility,
4409 CrateLint::SimplePath(id),
4411 if def == Def::Err {
4412 ty::Visibility::Public
4414 let vis = ty::Visibility::Restricted(def.def_id());
4415 if self.is_accessible(vis) {
4418 self.session.span_err(path.span, "visibilities can only be restricted \
4419 to ancestor modules");
4420 ty::Visibility::Public
4427 fn is_accessible(&self, vis: ty::Visibility) -> bool {
4428 vis.is_accessible_from(self.current_module.normal_ancestor_id, self)
4431 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
4432 vis.is_accessible_from(module.normal_ancestor_id, self)
4435 fn report_ambiguity_error(
4436 &self, name: Name, span: Span, _lexical: bool,
4437 def1: Def, is_import1: bool, is_glob1: bool, from_expansion1: bool, span1: Span,
4438 def2: Def, is_import2: bool, _is_glob2: bool, _from_expansion2: bool, span2: Span,
4440 let participle = |is_import: bool| if is_import { "imported" } else { "defined" };
4441 let msg1 = format!("`{}` could refer to the name {} here", name, participle(is_import1));
4443 format!("`{}` could also refer to the name {} here", name, participle(is_import2));
4444 let note = if from_expansion1 {
4445 Some(if let Def::Macro(..) = def1 {
4446 format!("macro-expanded {} do not shadow",
4447 if is_import1 { "macro imports" } else { "macros" })
4449 format!("macro-expanded {} do not shadow when used in a macro invocation path",
4450 if is_import1 { "imports" } else { "items" })
4452 } else if is_glob1 {
4453 Some(format!("consider adding an explicit import of `{}` to disambiguate", name))
4458 let mut err = struct_span_err!(self.session, span, E0659, "`{}` is ambiguous", name);
4459 err.span_note(span1, &msg1);
4461 Def::Macro(..) if span2.is_dummy() =>
4462 err.note(&format!("`{}` is also a builtin macro", name)),
4463 _ => err.span_note(span2, &msg2),
4465 if let Some(note) = note {
4471 fn report_errors(&mut self, krate: &Crate) {
4472 self.report_shadowing_errors();
4473 self.report_with_use_injections(krate);
4474 self.report_proc_macro_import(krate);
4475 let mut reported_spans = FxHashSet();
4477 for &(span_use, span_def) in &self.macro_expanded_macro_export_errors {
4478 let msg = "macro-expanded `macro_export` macros from the current crate \
4479 cannot be referred to by absolute paths";
4480 self.session.struct_span_err(span_use, msg)
4481 .span_note(span_def, "the macro is defined here")
4485 for &AmbiguityError { span, name, b1, b2, lexical } in &self.ambiguity_errors {
4486 if reported_spans.insert(span) {
4487 self.report_ambiguity_error(
4488 name, span, lexical,
4489 b1.def(), b1.is_import(), b1.is_glob_import(),
4490 b1.expansion != Mark::root(), b1.span,
4491 b2.def(), b2.is_import(), b2.is_glob_import(),
4492 b2.expansion != Mark::root(), b2.span,
4497 for &PrivacyError(span, name, binding) in &self.privacy_errors {
4498 if !reported_spans.insert(span) { continue }
4499 span_err!(self.session, span, E0603, "{} `{}` is private", binding.descr(), name);
4503 fn report_with_use_injections(&mut self, krate: &Crate) {
4504 for UseError { mut err, candidates, node_id, better } in self.use_injections.drain(..) {
4505 let (span, found_use) = UsePlacementFinder::check(krate, node_id);
4506 if !candidates.is_empty() {
4507 show_candidates(&mut err, span, &candidates, better, found_use);
4513 fn report_shadowing_errors(&mut self) {
4514 let mut reported_errors = FxHashSet();
4515 for binding in replace(&mut self.disallowed_shadowing, Vec::new()) {
4516 if self.resolve_legacy_scope(&binding.parent, binding.ident, false).is_some() &&
4517 reported_errors.insert((binding.ident, binding.span)) {
4518 let msg = format!("`{}` is already in scope", binding.ident);
4519 self.session.struct_span_err(binding.span, &msg)
4520 .note("macro-expanded `macro_rules!`s may not shadow \
4521 existing macros (see RFC 1560)")
4527 fn report_conflict<'b>(&mut self,
4531 new_binding: &NameBinding<'b>,
4532 old_binding: &NameBinding<'b>) {
4533 // Error on the second of two conflicting names
4534 if old_binding.span.lo() > new_binding.span.lo() {
4535 return self.report_conflict(parent, ident, ns, old_binding, new_binding);
4538 let container = match parent.kind {
4539 ModuleKind::Def(Def::Mod(_), _) => "module",
4540 ModuleKind::Def(Def::Trait(_), _) => "trait",
4541 ModuleKind::Block(..) => "block",
4545 let old_noun = match old_binding.is_import() {
4547 false => "definition",
4550 let new_participle = match new_binding.is_import() {
4555 let (name, span) = (ident.name, self.session.source_map().def_span(new_binding.span));
4557 if let Some(s) = self.name_already_seen.get(&name) {
4563 let old_kind = match (ns, old_binding.module()) {
4564 (ValueNS, _) => "value",
4565 (MacroNS, _) => "macro",
4566 (TypeNS, _) if old_binding.is_extern_crate() => "extern crate",
4567 (TypeNS, Some(module)) if module.is_normal() => "module",
4568 (TypeNS, Some(module)) if module.is_trait() => "trait",
4569 (TypeNS, _) => "type",
4572 let msg = format!("the name `{}` is defined multiple times", name);
4574 let mut err = match (old_binding.is_extern_crate(), new_binding.is_extern_crate()) {
4575 (true, true) => struct_span_err!(self.session, span, E0259, "{}", msg),
4576 (true, _) | (_, true) => match new_binding.is_import() && old_binding.is_import() {
4577 true => struct_span_err!(self.session, span, E0254, "{}", msg),
4578 false => struct_span_err!(self.session, span, E0260, "{}", msg),
4580 _ => match (old_binding.is_import(), new_binding.is_import()) {
4581 (false, false) => struct_span_err!(self.session, span, E0428, "{}", msg),
4582 (true, true) => struct_span_err!(self.session, span, E0252, "{}", msg),
4583 _ => struct_span_err!(self.session, span, E0255, "{}", msg),
4587 err.note(&format!("`{}` must be defined only once in the {} namespace of this {}",
4592 err.span_label(span, format!("`{}` re{} here", name, new_participle));
4593 if !old_binding.span.is_dummy() {
4594 err.span_label(self.session.source_map().def_span(old_binding.span),
4595 format!("previous {} of the {} `{}` here", old_noun, old_kind, name));
4598 // See https://github.com/rust-lang/rust/issues/32354
4599 if old_binding.is_import() || new_binding.is_import() {
4600 let binding = if new_binding.is_import() && !new_binding.span.is_dummy() {
4606 let cm = self.session.source_map();
4607 let rename_msg = "You can use `as` to change the binding name of the import";
4609 if let (Ok(snippet), false) = (cm.span_to_snippet(binding.span),
4610 binding.is_renamed_extern_crate()) {
4611 let suggested_name = if name.as_str().chars().next().unwrap().is_uppercase() {
4612 format!("Other{}", name)
4614 format!("other_{}", name)
4617 err.span_suggestion(binding.span,
4619 if snippet.ends_with(';') {
4620 format!("{} as {};",
4621 &snippet[..snippet.len()-1],
4624 format!("{} as {}", snippet, suggested_name)
4627 err.span_label(binding.span, rename_msg);
4632 self.name_already_seen.insert(name, span);
4636 fn is_self_type(path: &[Ident], namespace: Namespace) -> bool {
4637 namespace == TypeNS && path.len() == 1 && path[0].name == keywords::SelfType.name()
4640 fn is_self_value(path: &[Ident], namespace: Namespace) -> bool {
4641 namespace == ValueNS && path.len() == 1 && path[0].name == keywords::SelfValue.name()
4644 fn names_to_string(idents: &[Ident]) -> String {
4645 let mut result = String::new();
4646 for (i, ident) in idents.iter()
4647 .filter(|ident| ident.name != keywords::CrateRoot.name())
4650 result.push_str("::");
4652 result.push_str(&ident.as_str());
4657 fn path_names_to_string(path: &Path) -> String {
4658 names_to_string(&path.segments.iter()
4659 .map(|seg| seg.ident)
4660 .collect::<Vec<_>>())
4663 /// Get the path for an enum and the variant from an `ImportSuggestion` for an enum variant.
4664 fn import_candidate_to_paths(suggestion: &ImportSuggestion) -> (Span, String, String) {
4665 let variant_path = &suggestion.path;
4666 let variant_path_string = path_names_to_string(variant_path);
4668 let path_len = suggestion.path.segments.len();
4669 let enum_path = ast::Path {
4670 span: suggestion.path.span,
4671 segments: suggestion.path.segments[0..path_len - 1].to_vec(),
4673 let enum_path_string = path_names_to_string(&enum_path);
4675 (suggestion.path.span, variant_path_string, enum_path_string)
4679 /// When an entity with a given name is not available in scope, we search for
4680 /// entities with that name in all crates. This method allows outputting the
4681 /// results of this search in a programmer-friendly way
4682 fn show_candidates(err: &mut DiagnosticBuilder,
4683 // This is `None` if all placement locations are inside expansions
4685 candidates: &[ImportSuggestion],
4689 // we want consistent results across executions, but candidates are produced
4690 // by iterating through a hash map, so make sure they are ordered:
4691 let mut path_strings: Vec<_> =
4692 candidates.into_iter().map(|c| path_names_to_string(&c.path)).collect();
4693 path_strings.sort();
4695 let better = if better { "better " } else { "" };
4696 let msg_diff = match path_strings.len() {
4697 1 => " is found in another module, you can import it",
4698 _ => "s are found in other modules, you can import them",
4700 let msg = format!("possible {}candidate{} into scope", better, msg_diff);
4702 if let Some(span) = span {
4703 for candidate in &mut path_strings {
4704 // produce an additional newline to separate the new use statement
4705 // from the directly following item.
4706 let additional_newline = if found_use {
4711 *candidate = format!("use {};\n{}", candidate, additional_newline);
4714 err.span_suggestions(span, &msg, path_strings);
4718 for candidate in path_strings {
4720 msg.push_str(&candidate);
4725 /// A somewhat inefficient routine to obtain the name of a module.
4726 fn module_to_string(module: Module) -> Option<String> {
4727 let mut names = Vec::new();
4729 fn collect_mod(names: &mut Vec<Ident>, module: Module) {
4730 if let ModuleKind::Def(_, name) = module.kind {
4731 if let Some(parent) = module.parent {
4732 names.push(Ident::with_empty_ctxt(name));
4733 collect_mod(names, parent);
4736 // danger, shouldn't be ident?
4737 names.push(Ident::from_str("<opaque>"));
4738 collect_mod(names, module.parent.unwrap());
4741 collect_mod(&mut names, module);
4743 if names.is_empty() {
4746 Some(names_to_string(&names.into_iter()
4748 .collect::<Vec<_>>()))
4751 fn err_path_resolution() -> PathResolution {
4752 PathResolution::new(Def::Err)
4755 #[derive(PartialEq,Copy, Clone)]
4756 pub enum MakeGlobMap {
4761 #[derive(Copy, Clone, Debug)]
4763 /// Do not issue the lint
4766 /// This lint applies to some random path like `impl ::foo::Bar`
4767 /// or whatever. In this case, we can take the span of that path.
4770 /// This lint comes from a `use` statement. In this case, what we
4771 /// care about really is the *root* `use` statement; e.g., if we
4772 /// have nested things like `use a::{b, c}`, we care about the
4774 UsePath { root_id: NodeId, root_span: Span },
4776 /// This is the "trait item" from a fully qualified path. For example,
4777 /// we might be resolving `X::Y::Z` from a path like `<T as X::Y>::Z`.
4778 /// The `path_span` is the span of the to the trait itself (`X::Y`).
4779 QPathTrait { qpath_id: NodeId, qpath_span: Span },
4783 fn node_id(&self) -> Option<NodeId> {
4785 CrateLint::No => None,
4786 CrateLint::SimplePath(id) |
4787 CrateLint::UsePath { root_id: id, .. } |
4788 CrateLint::QPathTrait { qpath_id: id, .. } => Some(id),
4793 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }