1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
12 html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
13 html_root_url = "https://doc.rust-lang.org/nightly/")]
15 #![feature(crate_visibility_modifier)]
16 #![cfg_attr(not(stage0), feature(nll))]
17 #![cfg_attr(not(stage0), feature(infer_outlives_requirements))]
18 #![feature(rustc_diagnostic_macros)]
19 #![feature(slice_sort_by_cached_key)]
25 extern crate syntax_pos;
26 extern crate rustc_errors as errors;
30 extern crate rustc_data_structures;
31 extern crate rustc_metadata;
33 pub use rustc::hir::def::{Namespace, PerNS};
35 use self::TypeParameters::*;
38 use rustc::hir::map::{Definitions, DefCollector};
39 use rustc::hir::{self, PrimTy, Bool, Char, Float, Int, Uint, Str};
40 use rustc::middle::cstore::CrateStore;
41 use rustc::session::Session;
43 use rustc::hir::def::*;
44 use rustc::hir::def::Namespace::*;
45 use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, DefId};
47 use rustc::hir::{Freevar, FreevarMap, TraitCandidate, TraitMap, GlobMap};
48 use rustc::util::nodemap::{NodeMap, NodeSet, FxHashMap, FxHashSet, DefIdMap};
50 use rustc_metadata::creader::CrateLoader;
51 use rustc_metadata::cstore::CStore;
53 use syntax::source_map::SourceMap;
54 use syntax::ext::hygiene::{Mark, Transparency, SyntaxContext};
55 use syntax::ast::{self, Name, NodeId, Ident, FloatTy, IntTy, UintTy};
56 use syntax::ext::base::SyntaxExtension;
57 use syntax::ext::base::Determinacy::{self, Determined, Undetermined};
58 use syntax::ext::base::MacroKind;
59 use syntax::symbol::{Symbol, keywords};
60 use syntax::util::lev_distance::find_best_match_for_name;
62 use syntax::visit::{self, FnKind, Visitor};
64 use syntax::ast::{CRATE_NODE_ID, Arm, IsAsync, BindingMode, Block, Crate, Expr, ExprKind};
65 use syntax::ast::{FnDecl, ForeignItem, ForeignItemKind, GenericParamKind, Generics};
66 use syntax::ast::{Item, ItemKind, ImplItem, ImplItemKind};
67 use syntax::ast::{Label, Local, Mutability, Pat, PatKind, Path};
68 use syntax::ast::{QSelf, TraitItemKind, TraitRef, Ty, TyKind};
69 use syntax::feature_gate::{feature_err, GateIssue};
72 use syntax_pos::{Span, DUMMY_SP, MultiSpan};
73 use errors::{Applicability, DiagnosticBuilder, DiagnosticId};
75 use std::cell::{Cell, RefCell};
77 use std::collections::BTreeSet;
80 use std::mem::replace;
81 use rustc_data_structures::sync::Lrc;
83 use resolve_imports::{ImportDirective, ImportDirectiveSubclass, NameResolution, ImportResolver};
84 use macros::{InvocationData, LegacyBinding};
86 // NB: This module needs to be declared first so diagnostics are
87 // registered before they are used.
92 mod build_reduced_graph;
95 fn is_known_tool(name: Name) -> bool {
96 ["clippy", "rustfmt"].contains(&&*name.as_str())
99 /// A free importable items suggested in case of resolution failure.
100 struct ImportSuggestion {
104 /// A field or associated item from self type suggested in case of resolution failure.
105 enum AssocSuggestion {
112 struct BindingError {
114 origin: BTreeSet<Span>,
115 target: BTreeSet<Span>,
118 impl PartialOrd for BindingError {
119 fn partial_cmp(&self, other: &BindingError) -> Option<cmp::Ordering> {
120 Some(self.cmp(other))
124 impl PartialEq for BindingError {
125 fn eq(&self, other: &BindingError) -> bool {
126 self.name == other.name
130 impl Ord for BindingError {
131 fn cmp(&self, other: &BindingError) -> cmp::Ordering {
132 self.name.cmp(&other.name)
136 enum ResolutionError<'a> {
137 /// error E0401: can't use type parameters from outer function
138 TypeParametersFromOuterFunction(Def),
139 /// error E0403: the name is already used for a type parameter in this type parameter list
140 NameAlreadyUsedInTypeParameterList(Name, &'a Span),
141 /// error E0407: method is not a member of trait
142 MethodNotMemberOfTrait(Name, &'a str),
143 /// error E0437: type is not a member of trait
144 TypeNotMemberOfTrait(Name, &'a str),
145 /// error E0438: const is not a member of trait
146 ConstNotMemberOfTrait(Name, &'a str),
147 /// error E0408: variable `{}` is not bound in all patterns
148 VariableNotBoundInPattern(&'a BindingError),
149 /// error E0409: variable `{}` is bound in inconsistent ways within the same match arm
150 VariableBoundWithDifferentMode(Name, Span),
151 /// error E0415: identifier is bound more than once in this parameter list
152 IdentifierBoundMoreThanOnceInParameterList(&'a str),
153 /// error E0416: identifier is bound more than once in the same pattern
154 IdentifierBoundMoreThanOnceInSamePattern(&'a str),
155 /// error E0426: use of undeclared label
156 UndeclaredLabel(&'a str, Option<Name>),
157 /// error E0429: `self` imports are only allowed within a { } list
158 SelfImportsOnlyAllowedWithin,
159 /// error E0430: `self` import can only appear once in the list
160 SelfImportCanOnlyAppearOnceInTheList,
161 /// error E0431: `self` import can only appear in an import list with a non-empty prefix
162 SelfImportOnlyInImportListWithNonEmptyPrefix,
163 /// error E0432: unresolved import
164 UnresolvedImport(Option<(Span, &'a str, &'a str)>),
165 /// error E0433: failed to resolve
166 FailedToResolve(&'a str),
167 /// error E0434: can't capture dynamic environment in a fn item
168 CannotCaptureDynamicEnvironmentInFnItem,
169 /// error E0435: attempt to use a non-constant value in a constant
170 AttemptToUseNonConstantValueInConstant,
171 /// error E0530: X bindings cannot shadow Ys
172 BindingShadowsSomethingUnacceptable(&'a str, Name, &'a NameBinding<'a>),
173 /// error E0128: type parameters with a default cannot use forward declared identifiers
174 ForwardDeclaredTyParam,
177 /// Combines an error with provided span and emits it
179 /// This takes the error provided, combines it with the span and any additional spans inside the
180 /// error and emits it.
181 fn resolve_error<'sess, 'a>(resolver: &'sess Resolver,
183 resolution_error: ResolutionError<'a>) {
184 resolve_struct_error(resolver, span, resolution_error).emit();
187 fn resolve_struct_error<'sess, 'a>(resolver: &'sess Resolver,
189 resolution_error: ResolutionError<'a>)
190 -> DiagnosticBuilder<'sess> {
191 match resolution_error {
192 ResolutionError::TypeParametersFromOuterFunction(outer_def) => {
193 let mut err = struct_span_err!(resolver.session,
196 "can't use type parameters from outer function");
197 err.span_label(span, "use of type variable from outer function");
199 let cm = resolver.session.source_map();
201 Def::SelfTy(maybe_trait_defid, maybe_impl_defid) => {
202 if let Some(impl_span) = maybe_impl_defid.and_then(|def_id| {
203 resolver.definitions.opt_span(def_id)
206 reduce_impl_span_to_impl_keyword(cm, impl_span),
207 "`Self` type implicitly declared here, by this `impl`",
210 match (maybe_trait_defid, maybe_impl_defid) {
212 err.span_label(span, "can't use `Self` here");
215 err.span_label(span, "use a type here instead");
217 (None, None) => bug!("`impl` without trait nor type?"),
221 Def::TyParam(typaram_defid) => {
222 if let Some(typaram_span) = resolver.definitions.opt_span(typaram_defid) {
223 err.span_label(typaram_span, "type variable from outer function");
227 bug!("TypeParametersFromOuterFunction should only be used with Def::SelfTy or \
232 // Try to retrieve the span of the function signature and generate a new message with
233 // a local type parameter
234 let sugg_msg = "try using a local type parameter instead";
235 if let Some((sugg_span, new_snippet)) = cm.generate_local_type_param_snippet(span) {
236 // Suggest the modification to the user
237 err.span_suggestion_with_applicability(
241 Applicability::MachineApplicable,
243 } else if let Some(sp) = cm.generate_fn_name_span(span) {
244 err.span_label(sp, "try adding a local type parameter in this method instead");
246 err.help("try using a local type parameter instead");
251 ResolutionError::NameAlreadyUsedInTypeParameterList(name, first_use_span) => {
252 let mut err = struct_span_err!(resolver.session,
255 "the name `{}` is already used for a type parameter \
256 in this type parameter list",
258 err.span_label(span, "already used");
259 err.span_label(first_use_span.clone(), format!("first use of `{}`", name));
262 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
263 let mut err = struct_span_err!(resolver.session,
266 "method `{}` is not a member of trait `{}`",
269 err.span_label(span, format!("not a member of trait `{}`", trait_));
272 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
273 let mut err = struct_span_err!(resolver.session,
276 "type `{}` is not a member of trait `{}`",
279 err.span_label(span, format!("not a member of trait `{}`", trait_));
282 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
283 let mut err = struct_span_err!(resolver.session,
286 "const `{}` is not a member of trait `{}`",
289 err.span_label(span, format!("not a member of trait `{}`", trait_));
292 ResolutionError::VariableNotBoundInPattern(binding_error) => {
293 let target_sp = binding_error.target.iter().cloned().collect::<Vec<_>>();
294 let msp = MultiSpan::from_spans(target_sp.clone());
295 let msg = format!("variable `{}` is not bound in all patterns", binding_error.name);
296 let mut err = resolver.session.struct_span_err_with_code(
299 DiagnosticId::Error("E0408".into()),
301 for sp in target_sp {
302 err.span_label(sp, format!("pattern doesn't bind `{}`", binding_error.name));
304 let origin_sp = binding_error.origin.iter().cloned();
305 for sp in origin_sp {
306 err.span_label(sp, "variable not in all patterns");
310 ResolutionError::VariableBoundWithDifferentMode(variable_name,
311 first_binding_span) => {
312 let mut err = struct_span_err!(resolver.session,
315 "variable `{}` is bound in inconsistent \
316 ways within the same match arm",
318 err.span_label(span, "bound in different ways");
319 err.span_label(first_binding_span, "first binding");
322 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
323 let mut err = struct_span_err!(resolver.session,
326 "identifier `{}` is bound more than once in this parameter list",
328 err.span_label(span, "used as parameter more than once");
331 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
332 let mut err = struct_span_err!(resolver.session,
335 "identifier `{}` is bound more than once in the same pattern",
337 err.span_label(span, "used in a pattern more than once");
340 ResolutionError::UndeclaredLabel(name, lev_candidate) => {
341 let mut err = struct_span_err!(resolver.session,
344 "use of undeclared label `{}`",
346 if let Some(lev_candidate) = lev_candidate {
347 err.span_label(span, format!("did you mean `{}`?", lev_candidate));
349 err.span_label(span, format!("undeclared label `{}`", name));
353 ResolutionError::SelfImportsOnlyAllowedWithin => {
354 struct_span_err!(resolver.session,
358 "`self` imports are only allowed within a { } list")
360 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
361 let mut err = struct_span_err!(resolver.session, span, E0430,
362 "`self` import can only appear once in an import list");
363 err.span_label(span, "can only appear once in an import list");
366 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
367 let mut err = struct_span_err!(resolver.session, span, E0431,
368 "`self` import can only appear in an import list with \
369 a non-empty prefix");
370 err.span_label(span, "can only appear in an import list with a non-empty prefix");
373 ResolutionError::UnresolvedImport(name) => {
374 let (span, msg) = match name {
375 Some((sp, n, _)) => (sp, format!("unresolved import `{}`", n)),
376 None => (span, "unresolved import".to_owned()),
378 let mut err = struct_span_err!(resolver.session, span, E0432, "{}", msg);
379 if let Some((_, _, p)) = name {
380 err.span_label(span, p);
384 ResolutionError::FailedToResolve(msg) => {
385 let mut err = struct_span_err!(resolver.session, span, E0433,
386 "failed to resolve. {}", msg);
387 err.span_label(span, msg);
390 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
391 let mut err = struct_span_err!(resolver.session,
395 "can't capture dynamic environment in a fn item");
396 err.help("use the `|| { ... }` closure form instead");
399 ResolutionError::AttemptToUseNonConstantValueInConstant => {
400 let mut err = struct_span_err!(resolver.session, span, E0435,
401 "attempt to use a non-constant value in a constant");
402 err.span_label(span, "non-constant value");
405 ResolutionError::BindingShadowsSomethingUnacceptable(what_binding, name, binding) => {
406 let shadows_what = PathResolution::new(binding.def()).kind_name();
407 let mut err = struct_span_err!(resolver.session,
410 "{}s cannot shadow {}s", what_binding, shadows_what);
411 err.span_label(span, format!("cannot be named the same as a {}", shadows_what));
412 let participle = if binding.is_import() { "imported" } else { "defined" };
413 let msg = format!("a {} `{}` is {} here", shadows_what, name, participle);
414 err.span_label(binding.span, msg);
417 ResolutionError::ForwardDeclaredTyParam => {
418 let mut err = struct_span_err!(resolver.session, span, E0128,
419 "type parameters with a default cannot use \
420 forward declared identifiers");
422 span, "defaulted type parameters cannot be forward declared".to_string());
428 /// Adjust the impl span so that just the `impl` keyword is taken by removing
429 /// everything after `<` (`"impl<T> Iterator for A<T> {}" -> "impl"`) and
430 /// everything after the first whitespace (`"impl Iterator for A" -> "impl"`)
432 /// Attention: The method used is very fragile since it essentially duplicates the work of the
433 /// parser. If you need to use this function or something similar, please consider updating the
434 /// source_map functions and this function to something more robust.
435 fn reduce_impl_span_to_impl_keyword(cm: &SourceMap, impl_span: Span) -> Span {
436 let impl_span = cm.span_until_char(impl_span, '<');
437 let impl_span = cm.span_until_whitespace(impl_span);
441 #[derive(Copy, Clone, Debug)]
444 binding_mode: BindingMode,
447 /// Map from the name in a pattern to its binding mode.
448 type BindingMap = FxHashMap<Ident, BindingInfo>;
450 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
461 fn descr(self) -> &'static str {
463 PatternSource::Match => "match binding",
464 PatternSource::IfLet => "if let binding",
465 PatternSource::WhileLet => "while let binding",
466 PatternSource::Let => "let binding",
467 PatternSource::For => "for binding",
468 PatternSource::FnParam => "function parameter",
473 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
474 enum AliasPossibility {
479 #[derive(Copy, Clone, Debug)]
480 enum PathSource<'a> {
481 // Type paths `Path`.
483 // Trait paths in bounds or impls.
484 Trait(AliasPossibility),
485 // Expression paths `path`, with optional parent context.
486 Expr(Option<&'a Expr>),
487 // Paths in path patterns `Path`.
489 // Paths in struct expressions and patterns `Path { .. }`.
491 // Paths in tuple struct patterns `Path(..)`.
493 // `m::A::B` in `<T as m::A>::B::C`.
494 TraitItem(Namespace),
495 // Path in `pub(path)`
497 // Path in `use a::b::{...};`
501 impl<'a> PathSource<'a> {
502 fn namespace(self) -> Namespace {
504 PathSource::Type | PathSource::Trait(_) | PathSource::Struct |
505 PathSource::Visibility | PathSource::ImportPrefix => TypeNS,
506 PathSource::Expr(..) | PathSource::Pat | PathSource::TupleStruct => ValueNS,
507 PathSource::TraitItem(ns) => ns,
511 fn global_by_default(self) -> bool {
513 PathSource::Visibility | PathSource::ImportPrefix => true,
514 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
515 PathSource::Struct | PathSource::TupleStruct |
516 PathSource::Trait(_) | PathSource::TraitItem(..) => false,
520 fn defer_to_typeck(self) -> bool {
522 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
523 PathSource::Struct | PathSource::TupleStruct => true,
524 PathSource::Trait(_) | PathSource::TraitItem(..) |
525 PathSource::Visibility | PathSource::ImportPrefix => false,
529 fn descr_expected(self) -> &'static str {
531 PathSource::Type => "type",
532 PathSource::Trait(_) => "trait",
533 PathSource::Pat => "unit struct/variant or constant",
534 PathSource::Struct => "struct, variant or union type",
535 PathSource::TupleStruct => "tuple struct/variant",
536 PathSource::Visibility => "module",
537 PathSource::ImportPrefix => "module or enum",
538 PathSource::TraitItem(ns) => match ns {
539 TypeNS => "associated type",
540 ValueNS => "method or associated constant",
541 MacroNS => bug!("associated macro"),
543 PathSource::Expr(parent) => match parent.map(|p| &p.node) {
544 // "function" here means "anything callable" rather than `Def::Fn`,
545 // this is not precise but usually more helpful than just "value".
546 Some(&ExprKind::Call(..)) => "function",
552 fn is_expected(self, def: Def) -> bool {
554 PathSource::Type => match def {
555 Def::Struct(..) | Def::Union(..) | Def::Enum(..) |
556 Def::Trait(..) | Def::TyAlias(..) | Def::AssociatedTy(..) |
557 Def::PrimTy(..) | Def::TyParam(..) | Def::SelfTy(..) |
558 Def::Existential(..) |
559 Def::ForeignTy(..) => true,
562 PathSource::Trait(AliasPossibility::No) => match def {
563 Def::Trait(..) => true,
566 PathSource::Trait(AliasPossibility::Maybe) => match def {
567 Def::Trait(..) => true,
568 Def::TraitAlias(..) => true,
571 PathSource::Expr(..) => match def {
572 Def::StructCtor(_, CtorKind::Const) | Def::StructCtor(_, CtorKind::Fn) |
573 Def::VariantCtor(_, CtorKind::Const) | Def::VariantCtor(_, CtorKind::Fn) |
574 Def::Const(..) | Def::Static(..) | Def::Local(..) | Def::Upvar(..) |
575 Def::Fn(..) | Def::Method(..) | Def::AssociatedConst(..) => true,
578 PathSource::Pat => match def {
579 Def::StructCtor(_, CtorKind::Const) |
580 Def::VariantCtor(_, CtorKind::Const) |
581 Def::Const(..) | Def::AssociatedConst(..) => true,
584 PathSource::TupleStruct => match def {
585 Def::StructCtor(_, CtorKind::Fn) | Def::VariantCtor(_, CtorKind::Fn) => true,
588 PathSource::Struct => match def {
589 Def::Struct(..) | Def::Union(..) | Def::Variant(..) |
590 Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) => true,
593 PathSource::TraitItem(ns) => match def {
594 Def::AssociatedConst(..) | Def::Method(..) if ns == ValueNS => true,
595 Def::AssociatedTy(..) if ns == TypeNS => true,
598 PathSource::ImportPrefix => match def {
599 Def::Mod(..) | Def::Enum(..) => true,
602 PathSource::Visibility => match def {
603 Def::Mod(..) => true,
609 fn error_code(self, has_unexpected_resolution: bool) -> &'static str {
610 __diagnostic_used!(E0404);
611 __diagnostic_used!(E0405);
612 __diagnostic_used!(E0412);
613 __diagnostic_used!(E0422);
614 __diagnostic_used!(E0423);
615 __diagnostic_used!(E0425);
616 __diagnostic_used!(E0531);
617 __diagnostic_used!(E0532);
618 __diagnostic_used!(E0573);
619 __diagnostic_used!(E0574);
620 __diagnostic_used!(E0575);
621 __diagnostic_used!(E0576);
622 __diagnostic_used!(E0577);
623 __diagnostic_used!(E0578);
624 match (self, has_unexpected_resolution) {
625 (PathSource::Trait(_), true) => "E0404",
626 (PathSource::Trait(_), false) => "E0405",
627 (PathSource::Type, true) => "E0573",
628 (PathSource::Type, false) => "E0412",
629 (PathSource::Struct, true) => "E0574",
630 (PathSource::Struct, false) => "E0422",
631 (PathSource::Expr(..), true) => "E0423",
632 (PathSource::Expr(..), false) => "E0425",
633 (PathSource::Pat, true) | (PathSource::TupleStruct, true) => "E0532",
634 (PathSource::Pat, false) | (PathSource::TupleStruct, false) => "E0531",
635 (PathSource::TraitItem(..), true) => "E0575",
636 (PathSource::TraitItem(..), false) => "E0576",
637 (PathSource::Visibility, true) | (PathSource::ImportPrefix, true) => "E0577",
638 (PathSource::Visibility, false) | (PathSource::ImportPrefix, false) => "E0578",
643 struct UsePlacementFinder {
644 target_module: NodeId,
649 impl UsePlacementFinder {
650 fn check(krate: &Crate, target_module: NodeId) -> (Option<Span>, bool) {
651 let mut finder = UsePlacementFinder {
656 visit::walk_crate(&mut finder, krate);
657 (finder.span, finder.found_use)
661 impl<'tcx> Visitor<'tcx> for UsePlacementFinder {
664 module: &'tcx ast::Mod,
666 _: &[ast::Attribute],
669 if self.span.is_some() {
672 if node_id != self.target_module {
673 visit::walk_mod(self, module);
676 // find a use statement
677 for item in &module.items {
679 ItemKind::Use(..) => {
680 // don't suggest placing a use before the prelude
681 // import or other generated ones
682 if item.span.ctxt().outer().expn_info().is_none() {
683 self.span = Some(item.span.shrink_to_lo());
684 self.found_use = true;
688 // don't place use before extern crate
689 ItemKind::ExternCrate(_) => {}
690 // but place them before the first other item
691 _ => if self.span.map_or(true, |span| item.span < span ) {
692 if item.span.ctxt().outer().expn_info().is_none() {
693 // don't insert between attributes and an item
694 if item.attrs.is_empty() {
695 self.span = Some(item.span.shrink_to_lo());
697 // find the first attribute on the item
698 for attr in &item.attrs {
699 if self.span.map_or(true, |span| attr.span < span) {
700 self.span = Some(attr.span.shrink_to_lo());
711 /// This thing walks the whole crate in DFS manner, visiting each item, resolving names as it goes.
712 impl<'a, 'tcx, 'cl> Visitor<'tcx> for Resolver<'a, 'cl> {
713 fn visit_item(&mut self, item: &'tcx Item) {
714 self.resolve_item(item);
716 fn visit_arm(&mut self, arm: &'tcx Arm) {
717 self.resolve_arm(arm);
719 fn visit_block(&mut self, block: &'tcx Block) {
720 self.resolve_block(block);
722 fn visit_anon_const(&mut self, constant: &'tcx ast::AnonConst) {
723 self.with_constant_rib(|this| {
724 visit::walk_anon_const(this, constant);
727 fn visit_expr(&mut self, expr: &'tcx Expr) {
728 self.resolve_expr(expr, None);
730 fn visit_local(&mut self, local: &'tcx Local) {
731 self.resolve_local(local);
733 fn visit_ty(&mut self, ty: &'tcx Ty) {
735 TyKind::Path(ref qself, ref path) => {
736 self.smart_resolve_path(ty.id, qself.as_ref(), path, PathSource::Type);
738 TyKind::ImplicitSelf => {
739 let self_ty = keywords::SelfType.ident();
740 let def = self.resolve_ident_in_lexical_scope(self_ty, TypeNS, Some(ty.id), ty.span)
741 .map_or(Def::Err, |d| d.def());
742 self.record_def(ty.id, PathResolution::new(def));
746 visit::walk_ty(self, ty);
748 fn visit_poly_trait_ref(&mut self,
749 tref: &'tcx ast::PolyTraitRef,
750 m: &'tcx ast::TraitBoundModifier) {
751 self.smart_resolve_path(tref.trait_ref.ref_id, None,
752 &tref.trait_ref.path, PathSource::Trait(AliasPossibility::Maybe));
753 visit::walk_poly_trait_ref(self, tref, m);
755 fn visit_foreign_item(&mut self, foreign_item: &'tcx ForeignItem) {
756 let type_parameters = match foreign_item.node {
757 ForeignItemKind::Fn(_, ref generics) => {
758 HasTypeParameters(generics, ItemRibKind)
760 ForeignItemKind::Static(..) => NoTypeParameters,
761 ForeignItemKind::Ty => NoTypeParameters,
762 ForeignItemKind::Macro(..) => NoTypeParameters,
764 self.with_type_parameter_rib(type_parameters, |this| {
765 visit::walk_foreign_item(this, foreign_item);
768 fn visit_fn(&mut self,
769 function_kind: FnKind<'tcx>,
770 declaration: &'tcx FnDecl,
774 let (rib_kind, asyncness) = match function_kind {
775 FnKind::ItemFn(_, ref header, ..) =>
776 (ItemRibKind, header.asyncness),
777 FnKind::Method(_, ref sig, _, _) =>
778 (TraitOrImplItemRibKind, sig.header.asyncness),
779 FnKind::Closure(_) =>
780 // Async closures aren't resolved through `visit_fn`-- they're
781 // processed separately
782 (ClosureRibKind(node_id), IsAsync::NotAsync),
785 // Create a value rib for the function.
786 self.ribs[ValueNS].push(Rib::new(rib_kind));
788 // Create a label rib for the function.
789 self.label_ribs.push(Rib::new(rib_kind));
791 // Add each argument to the rib.
792 let mut bindings_list = FxHashMap();
793 for argument in &declaration.inputs {
794 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
796 self.visit_ty(&argument.ty);
798 debug!("(resolving function) recorded argument");
800 visit::walk_fn_ret_ty(self, &declaration.output);
802 // Resolve the function body, potentially inside the body of an async closure
803 if let IsAsync::Async { closure_id, .. } = asyncness {
804 let rib_kind = ClosureRibKind(closure_id);
805 self.ribs[ValueNS].push(Rib::new(rib_kind));
806 self.label_ribs.push(Rib::new(rib_kind));
809 match function_kind {
810 FnKind::ItemFn(.., body) |
811 FnKind::Method(.., body) => {
812 self.visit_block(body);
814 FnKind::Closure(body) => {
815 self.visit_expr(body);
819 // Leave the body of the async closure
820 if asyncness.is_async() {
821 self.label_ribs.pop();
822 self.ribs[ValueNS].pop();
825 debug!("(resolving function) leaving function");
827 self.label_ribs.pop();
828 self.ribs[ValueNS].pop();
830 fn visit_generics(&mut self, generics: &'tcx Generics) {
831 // For type parameter defaults, we have to ban access
832 // to following type parameters, as the Substs can only
833 // provide previous type parameters as they're built. We
834 // put all the parameters on the ban list and then remove
835 // them one by one as they are processed and become available.
836 let mut default_ban_rib = Rib::new(ForwardTyParamBanRibKind);
837 let mut found_default = false;
838 default_ban_rib.bindings.extend(generics.params.iter()
839 .filter_map(|param| match param.kind {
840 GenericParamKind::Lifetime { .. } => None,
841 GenericParamKind::Type { ref default, .. } => {
842 found_default |= default.is_some();
844 Some((Ident::with_empty_ctxt(param.ident.name), Def::Err))
851 for param in &generics.params {
853 GenericParamKind::Lifetime { .. } => self.visit_generic_param(param),
854 GenericParamKind::Type { ref default, .. } => {
855 for bound in ¶m.bounds {
856 self.visit_param_bound(bound);
859 if let Some(ref ty) = default {
860 self.ribs[TypeNS].push(default_ban_rib);
862 default_ban_rib = self.ribs[TypeNS].pop().unwrap();
865 // Allow all following defaults to refer to this type parameter.
866 default_ban_rib.bindings.remove(&Ident::with_empty_ctxt(param.ident.name));
870 for p in &generics.where_clause.predicates {
871 self.visit_where_predicate(p);
876 #[derive(Copy, Clone)]
877 enum TypeParameters<'a, 'b> {
879 HasTypeParameters(// Type parameters.
882 // The kind of the rib used for type parameters.
886 /// The rib kind controls the translation of local
887 /// definitions (`Def::Local`) to upvars (`Def::Upvar`).
888 #[derive(Copy, Clone, Debug)]
890 /// No translation needs to be applied.
893 /// We passed through a closure scope at the given node ID.
894 /// Translate upvars as appropriate.
895 ClosureRibKind(NodeId /* func id */),
897 /// We passed through an impl or trait and are now in one of its
898 /// methods or associated types. Allow references to ty params that impl or trait
899 /// binds. Disallow any other upvars (including other ty params that are
901 TraitOrImplItemRibKind,
903 /// We passed through an item scope. Disallow upvars.
906 /// We're in a constant item. Can't refer to dynamic stuff.
909 /// We passed through a module.
910 ModuleRibKind(Module<'a>),
912 /// We passed through a `macro_rules!` statement
913 MacroDefinition(DefId),
915 /// All bindings in this rib are type parameters that can't be used
916 /// from the default of a type parameter because they're not declared
917 /// before said type parameter. Also see the `visit_generics` override.
918 ForwardTyParamBanRibKind,
923 /// A rib represents a scope names can live in. Note that these appear in many places, not just
924 /// around braces. At any place where the list of accessible names (of the given namespace)
925 /// changes or a new restrictions on the name accessibility are introduced, a new rib is put onto a
926 /// stack. This may be, for example, a `let` statement (because it introduces variables), a macro,
929 /// Different [rib kinds](enum.RibKind) are transparent for different names.
931 /// The resolution keeps a separate stack of ribs as it traverses the AST for each namespace. When
932 /// resolving, the name is looked up from inside out.
935 bindings: FxHashMap<Ident, Def>,
940 fn new(kind: RibKind<'a>) -> Rib<'a> {
942 bindings: FxHashMap(),
948 /// An intermediate resolution result.
950 /// This refers to the thing referred by a name. The difference between `Def` and `Item` is that
951 /// items are visible in their whole block, while defs only from the place they are defined
953 enum LexicalScopeBinding<'a> {
954 Item(&'a NameBinding<'a>),
958 impl<'a> LexicalScopeBinding<'a> {
959 fn item(self) -> Option<&'a NameBinding<'a>> {
961 LexicalScopeBinding::Item(binding) => Some(binding),
966 fn def(self) -> Def {
968 LexicalScopeBinding::Item(binding) => binding.def(),
969 LexicalScopeBinding::Def(def) => def,
974 #[derive(Copy, Clone, Debug)]
975 pub enum ModuleOrUniformRoot<'a> {
979 /// The `{{root}}` (`CrateRoot` aka "global") / `extern` initial segment
980 /// in which external crates resolve, and also `crate` (only in `{{root}}`,
981 /// but *not* `extern`), in the Rust 2018 edition.
985 #[derive(Clone, Debug)]
986 enum PathResult<'a> {
987 Module(ModuleOrUniformRoot<'a>),
988 NonModule(PathResolution),
990 Failed(Span, String, bool /* is the error from the last segment? */),
994 /// An anonymous module, eg. just a block.
999 /// { // This is an anonymous module
1000 /// f(); // This resolves to (2) as we are inside the block.
1001 /// fn f() {} // (2)
1003 /// f(); // Resolves to (1)
1007 /// Any module with a name.
1011 /// * A normal module ‒ either `mod from_file;` or `mod from_block { }`.
1012 /// * A trait or an enum (it implicitly contains associated types, methods and variant
1017 /// One node in the tree of modules.
1018 pub struct ModuleData<'a> {
1019 parent: Option<Module<'a>>,
1022 // The def id of the closest normal module (`mod`) ancestor (including this module).
1023 normal_ancestor_id: DefId,
1025 resolutions: RefCell<FxHashMap<(Ident, Namespace), &'a RefCell<NameResolution<'a>>>>,
1026 legacy_macro_resolutions: RefCell<Vec<(Mark, Ident, MacroKind, Option<Def>)>>,
1027 macro_resolutions: RefCell<Vec<(Box<[Ident]>, Span)>>,
1029 // Macro invocations that can expand into items in this module.
1030 unresolved_invocations: RefCell<FxHashSet<Mark>>,
1032 no_implicit_prelude: bool,
1034 glob_importers: RefCell<Vec<&'a ImportDirective<'a>>>,
1035 globs: RefCell<Vec<&'a ImportDirective<'a>>>,
1037 // Used to memoize the traits in this module for faster searches through all traits in scope.
1038 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
1040 // Whether this module is populated. If not populated, any attempt to
1041 // access the children must be preceded with a
1042 // `populate_module_if_necessary` call.
1043 populated: Cell<bool>,
1045 /// Span of the module itself. Used for error reporting.
1051 type Module<'a> = &'a ModuleData<'a>;
1053 impl<'a> ModuleData<'a> {
1054 fn new(parent: Option<Module<'a>>,
1056 normal_ancestor_id: DefId,
1058 span: Span) -> Self {
1063 resolutions: RefCell::new(FxHashMap()),
1064 legacy_macro_resolutions: RefCell::new(Vec::new()),
1065 macro_resolutions: RefCell::new(Vec::new()),
1066 unresolved_invocations: RefCell::new(FxHashSet()),
1067 no_implicit_prelude: false,
1068 glob_importers: RefCell::new(Vec::new()),
1069 globs: RefCell::new(Vec::new()),
1070 traits: RefCell::new(None),
1071 populated: Cell::new(normal_ancestor_id.is_local()),
1077 fn for_each_child<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
1078 for (&(ident, ns), name_resolution) in self.resolutions.borrow().iter() {
1079 name_resolution.borrow().binding.map(|binding| f(ident, ns, binding));
1083 fn for_each_child_stable<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
1084 let resolutions = self.resolutions.borrow();
1085 let mut resolutions = resolutions.iter().collect::<Vec<_>>();
1086 resolutions.sort_by_cached_key(|&(&(ident, ns), _)| (ident.as_str(), ns));
1087 for &(&(ident, ns), &resolution) in resolutions.iter() {
1088 resolution.borrow().binding.map(|binding| f(ident, ns, binding));
1092 fn def(&self) -> Option<Def> {
1094 ModuleKind::Def(def, _) => Some(def),
1099 fn def_id(&self) -> Option<DefId> {
1100 self.def().as_ref().map(Def::def_id)
1103 // `self` resolves to the first module ancestor that `is_normal`.
1104 fn is_normal(&self) -> bool {
1106 ModuleKind::Def(Def::Mod(_), _) => true,
1111 fn is_trait(&self) -> bool {
1113 ModuleKind::Def(Def::Trait(_), _) => true,
1118 fn is_local(&self) -> bool {
1119 self.normal_ancestor_id.is_local()
1122 fn nearest_item_scope(&'a self) -> Module<'a> {
1123 if self.is_trait() { self.parent.unwrap() } else { self }
1127 impl<'a> fmt::Debug for ModuleData<'a> {
1128 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1129 write!(f, "{:?}", self.def())
1133 /// Records a possibly-private value, type, or module definition.
1134 #[derive(Clone, Debug)]
1135 pub struct NameBinding<'a> {
1136 kind: NameBindingKind<'a>,
1139 vis: ty::Visibility,
1142 pub trait ToNameBinding<'a> {
1143 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
1146 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
1147 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
1152 #[derive(Clone, Debug)]
1153 enum NameBindingKind<'a> {
1154 Def(Def, /* is_macro_export */ bool),
1157 binding: &'a NameBinding<'a>,
1158 directive: &'a ImportDirective<'a>,
1162 b1: &'a NameBinding<'a>,
1163 b2: &'a NameBinding<'a>,
1167 struct PrivacyError<'a>(Span, Name, &'a NameBinding<'a>);
1169 struct UseError<'a> {
1170 err: DiagnosticBuilder<'a>,
1171 /// Attach `use` statements for these candidates
1172 candidates: Vec<ImportSuggestion>,
1173 /// The node id of the module to place the use statements in
1175 /// Whether the diagnostic should state that it's "better"
1179 struct AmbiguityError<'a> {
1183 b1: &'a NameBinding<'a>,
1184 b2: &'a NameBinding<'a>,
1187 impl<'a> NameBinding<'a> {
1188 fn module(&self) -> Option<Module<'a>> {
1190 NameBindingKind::Module(module) => Some(module),
1191 NameBindingKind::Import { binding, .. } => binding.module(),
1196 fn def(&self) -> Def {
1198 NameBindingKind::Def(def, _) => def,
1199 NameBindingKind::Module(module) => module.def().unwrap(),
1200 NameBindingKind::Import { binding, .. } => binding.def(),
1201 NameBindingKind::Ambiguity { .. } => Def::Err,
1205 fn def_ignoring_ambiguity(&self) -> Def {
1207 NameBindingKind::Import { binding, .. } => binding.def_ignoring_ambiguity(),
1208 NameBindingKind::Ambiguity { b1, .. } => b1.def_ignoring_ambiguity(),
1213 fn get_macro<'b: 'a>(&self, resolver: &mut Resolver<'a, 'b>) -> Lrc<SyntaxExtension> {
1214 resolver.get_macro(self.def_ignoring_ambiguity())
1217 // We sometimes need to treat variants as `pub` for backwards compatibility
1218 fn pseudo_vis(&self) -> ty::Visibility {
1219 if self.is_variant() && self.def().def_id().is_local() {
1220 ty::Visibility::Public
1226 fn is_variant(&self) -> bool {
1228 NameBindingKind::Def(Def::Variant(..), _) |
1229 NameBindingKind::Def(Def::VariantCtor(..), _) => true,
1234 fn is_extern_crate(&self) -> bool {
1236 NameBindingKind::Import {
1237 directive: &ImportDirective {
1238 subclass: ImportDirectiveSubclass::ExternCrate(_), ..
1245 fn is_import(&self) -> bool {
1247 NameBindingKind::Import { .. } => true,
1252 fn is_renamed_extern_crate(&self) -> bool {
1253 if let NameBindingKind::Import { directive, ..} = self.kind {
1254 if let ImportDirectiveSubclass::ExternCrate(Some(_)) = directive.subclass {
1261 fn is_glob_import(&self) -> bool {
1263 NameBindingKind::Import { directive, .. } => directive.is_glob(),
1264 NameBindingKind::Ambiguity { b1, .. } => b1.is_glob_import(),
1269 fn is_importable(&self) -> bool {
1271 Def::AssociatedConst(..) | Def::Method(..) | Def::AssociatedTy(..) => false,
1276 fn is_macro_def(&self) -> bool {
1278 NameBindingKind::Def(Def::Macro(..), _) => true,
1283 fn descr(&self) -> &'static str {
1284 if self.is_extern_crate() { "extern crate" } else { self.def().kind_name() }
1288 /// Interns the names of the primitive types.
1290 /// All other types are defined somewhere and possibly imported, but the primitive ones need
1291 /// special handling, since they have no place of origin.
1292 struct PrimitiveTypeTable {
1293 primitive_types: FxHashMap<Name, PrimTy>,
1296 impl PrimitiveTypeTable {
1297 fn new() -> PrimitiveTypeTable {
1298 let mut table = PrimitiveTypeTable { primitive_types: FxHashMap() };
1300 table.intern("bool", Bool);
1301 table.intern("char", Char);
1302 table.intern("f32", Float(FloatTy::F32));
1303 table.intern("f64", Float(FloatTy::F64));
1304 table.intern("isize", Int(IntTy::Isize));
1305 table.intern("i8", Int(IntTy::I8));
1306 table.intern("i16", Int(IntTy::I16));
1307 table.intern("i32", Int(IntTy::I32));
1308 table.intern("i64", Int(IntTy::I64));
1309 table.intern("i128", Int(IntTy::I128));
1310 table.intern("str", Str);
1311 table.intern("usize", Uint(UintTy::Usize));
1312 table.intern("u8", Uint(UintTy::U8));
1313 table.intern("u16", Uint(UintTy::U16));
1314 table.intern("u32", Uint(UintTy::U32));
1315 table.intern("u64", Uint(UintTy::U64));
1316 table.intern("u128", Uint(UintTy::U128));
1320 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1321 self.primitive_types.insert(Symbol::intern(string), primitive_type);
1325 /// The main resolver class.
1327 /// This is the visitor that walks the whole crate.
1328 pub struct Resolver<'a, 'b: 'a> {
1329 session: &'a Session,
1332 pub definitions: Definitions,
1334 graph_root: Module<'a>,
1336 prelude: Option<Module<'a>>,
1337 extern_prelude: FxHashSet<Name>,
1339 /// n.b. This is used only for better diagnostics, not name resolution itself.
1340 has_self: FxHashSet<DefId>,
1342 /// Names of fields of an item `DefId` accessible with dot syntax.
1343 /// Used for hints during error reporting.
1344 field_names: FxHashMap<DefId, Vec<Name>>,
1346 /// All imports known to succeed or fail.
1347 determined_imports: Vec<&'a ImportDirective<'a>>,
1349 /// All non-determined imports.
1350 indeterminate_imports: Vec<&'a ImportDirective<'a>>,
1352 /// The module that represents the current item scope.
1353 current_module: Module<'a>,
1355 /// The current set of local scopes for types and values.
1356 /// FIXME #4948: Reuse ribs to avoid allocation.
1357 ribs: PerNS<Vec<Rib<'a>>>,
1359 /// The current set of local scopes, for labels.
1360 label_ribs: Vec<Rib<'a>>,
1362 /// The trait that the current context can refer to.
1363 current_trait_ref: Option<(Module<'a>, TraitRef)>,
1365 /// The current self type if inside an impl (used for better errors).
1366 current_self_type: Option<Ty>,
1368 /// The idents for the primitive types.
1369 primitive_type_table: PrimitiveTypeTable,
1372 import_map: ImportMap,
1373 pub freevars: FreevarMap,
1374 freevars_seen: NodeMap<NodeMap<usize>>,
1375 pub export_map: ExportMap,
1376 pub trait_map: TraitMap,
1378 /// A map from nodes to anonymous modules.
1379 /// Anonymous modules are pseudo-modules that are implicitly created around items
1380 /// contained within blocks.
1382 /// For example, if we have this:
1390 /// There will be an anonymous module created around `g` with the ID of the
1391 /// entry block for `f`.
1392 block_map: NodeMap<Module<'a>>,
1393 module_map: FxHashMap<DefId, Module<'a>>,
1394 extern_module_map: FxHashMap<(DefId, bool /* MacrosOnly? */), Module<'a>>,
1396 pub make_glob_map: bool,
1397 /// Maps imports to the names of items actually imported (this actually maps
1398 /// all imports, but only glob imports are actually interesting).
1399 pub glob_map: GlobMap,
1401 used_imports: FxHashSet<(NodeId, Namespace)>,
1402 pub maybe_unused_trait_imports: NodeSet,
1403 pub maybe_unused_extern_crates: Vec<(NodeId, Span)>,
1405 /// A list of labels as of yet unused. Labels will be removed from this map when
1406 /// they are used (in a `break` or `continue` statement)
1407 pub unused_labels: FxHashMap<NodeId, Span>,
1409 /// privacy errors are delayed until the end in order to deduplicate them
1410 privacy_errors: Vec<PrivacyError<'a>>,
1411 /// ambiguity errors are delayed for deduplication
1412 ambiguity_errors: Vec<AmbiguityError<'a>>,
1413 /// `use` injections are delayed for better placement and deduplication
1414 use_injections: Vec<UseError<'a>>,
1415 /// `use` injections for proc macros wrongly imported with #[macro_use]
1416 proc_mac_errors: Vec<macros::ProcMacError>,
1417 /// crate-local macro expanded `macro_export` referred to by a module-relative path
1418 macro_expanded_macro_export_errors: BTreeSet<(Span, Span)>,
1419 /// macro-expanded `macro_rules` shadowing existing macros
1420 disallowed_shadowing: Vec<&'a LegacyBinding<'a>>,
1422 arenas: &'a ResolverArenas<'a>,
1423 dummy_binding: &'a NameBinding<'a>,
1425 crate_loader: &'a mut CrateLoader<'b>,
1426 macro_names: FxHashSet<Ident>,
1427 macro_prelude: FxHashMap<Name, &'a NameBinding<'a>>,
1428 unshadowable_attrs: FxHashMap<Name, &'a NameBinding<'a>>,
1429 pub all_macros: FxHashMap<Name, Def>,
1430 macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>,
1431 macro_defs: FxHashMap<Mark, DefId>,
1432 local_macro_def_scopes: FxHashMap<NodeId, Module<'a>>,
1433 pub whitelisted_legacy_custom_derives: Vec<Name>,
1434 pub found_unresolved_macro: bool,
1436 /// List of crate local macros that we need to warn about as being unused.
1437 /// Right now this only includes macro_rules! macros, and macros 2.0.
1438 unused_macros: FxHashSet<DefId>,
1440 /// Maps the `Mark` of an expansion to its containing module or block.
1441 invocations: FxHashMap<Mark, &'a InvocationData<'a>>,
1443 /// Avoid duplicated errors for "name already defined".
1444 name_already_seen: FxHashMap<Name, Span>,
1446 /// A set of procedural macros imported by `#[macro_use]` that have already been warned about
1447 warned_proc_macros: FxHashSet<Name>,
1449 potentially_unused_imports: Vec<&'a ImportDirective<'a>>,
1451 /// This table maps struct IDs into struct constructor IDs,
1452 /// it's not used during normal resolution, only for better error reporting.
1453 struct_constructors: DefIdMap<(Def, ty::Visibility)>,
1455 /// Only used for better errors on `fn(): fn()`
1456 current_type_ascription: Vec<Span>,
1458 injected_crate: Option<Module<'a>>,
1460 /// Only supposed to be used by rustdoc, otherwise should be false.
1461 pub ignore_extern_prelude_feature: bool,
1464 /// Nothing really interesting here, it just provides memory for the rest of the crate.
1465 pub struct ResolverArenas<'a> {
1466 modules: arena::TypedArena<ModuleData<'a>>,
1467 local_modules: RefCell<Vec<Module<'a>>>,
1468 name_bindings: arena::TypedArena<NameBinding<'a>>,
1469 import_directives: arena::TypedArena<ImportDirective<'a>>,
1470 name_resolutions: arena::TypedArena<RefCell<NameResolution<'a>>>,
1471 invocation_data: arena::TypedArena<InvocationData<'a>>,
1472 legacy_bindings: arena::TypedArena<LegacyBinding<'a>>,
1475 impl<'a> ResolverArenas<'a> {
1476 fn alloc_module(&'a self, module: ModuleData<'a>) -> Module<'a> {
1477 let module = self.modules.alloc(module);
1478 if module.def_id().map(|def_id| def_id.is_local()).unwrap_or(true) {
1479 self.local_modules.borrow_mut().push(module);
1483 fn local_modules(&'a self) -> ::std::cell::Ref<'a, Vec<Module<'a>>> {
1484 self.local_modules.borrow()
1486 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1487 self.name_bindings.alloc(name_binding)
1489 fn alloc_import_directive(&'a self, import_directive: ImportDirective<'a>)
1490 -> &'a ImportDirective {
1491 self.import_directives.alloc(import_directive)
1493 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1494 self.name_resolutions.alloc(Default::default())
1496 fn alloc_invocation_data(&'a self, expansion_data: InvocationData<'a>)
1497 -> &'a InvocationData<'a> {
1498 self.invocation_data.alloc(expansion_data)
1500 fn alloc_legacy_binding(&'a self, binding: LegacyBinding<'a>) -> &'a LegacyBinding<'a> {
1501 self.legacy_bindings.alloc(binding)
1505 impl<'a, 'b: 'a, 'cl: 'b> ty::DefIdTree for &'a Resolver<'b, 'cl> {
1506 fn parent(self, id: DefId) -> Option<DefId> {
1508 LOCAL_CRATE => self.definitions.def_key(id.index).parent,
1509 _ => self.cstore.def_key(id).parent,
1510 }.map(|index| DefId { index, ..id })
1514 /// This interface is used through the AST→HIR step, to embed full paths into the HIR. After that
1515 /// the resolver is no longer needed as all the relevant information is inline.
1516 impl<'a, 'cl> hir::lowering::Resolver for Resolver<'a, 'cl> {
1517 fn resolve_hir_path(&mut self, path: &mut hir::Path, is_value: bool) {
1518 self.resolve_hir_path_cb(path, is_value,
1519 |resolver, span, error| resolve_error(resolver, span, error))
1522 fn resolve_str_path(
1525 crate_root: Option<&str>,
1526 components: &[&str],
1527 args: Option<P<hir::GenericArgs>>,
1530 let mut segments = iter::once(keywords::CrateRoot.ident())
1532 crate_root.into_iter()
1533 .chain(components.iter().cloned())
1534 .map(Ident::from_str)
1535 ).map(hir::PathSegment::from_ident).collect::<Vec<_>>();
1537 if let Some(args) = args {
1538 let ident = segments.last().unwrap().ident;
1539 *segments.last_mut().unwrap() = hir::PathSegment {
1546 let mut path = hir::Path {
1549 segments: segments.into(),
1552 self.resolve_hir_path(&mut path, is_value);
1556 fn get_resolution(&mut self, id: NodeId) -> Option<PathResolution> {
1557 self.def_map.get(&id).cloned()
1560 fn get_import(&mut self, id: NodeId) -> PerNS<Option<PathResolution>> {
1561 self.import_map.get(&id).cloned().unwrap_or_default()
1564 fn definitions(&mut self) -> &mut Definitions {
1565 &mut self.definitions
1569 impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
1570 /// Rustdoc uses this to resolve things in a recoverable way. ResolutionError<'a>
1571 /// isn't something that can be returned because it can't be made to live that long,
1572 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
1573 /// just that an error occurred.
1574 pub fn resolve_str_path_error(&mut self, span: Span, path_str: &str, is_value: bool)
1575 -> Result<hir::Path, ()> {
1577 let mut errored = false;
1579 let mut path = if path_str.starts_with("::") {
1583 segments: iter::once(keywords::CrateRoot.ident()).chain({
1584 path_str.split("::").skip(1).map(Ident::from_str)
1585 }).map(hir::PathSegment::from_ident).collect(),
1591 segments: path_str.split("::").map(Ident::from_str)
1592 .map(hir::PathSegment::from_ident).collect(),
1595 self.resolve_hir_path_cb(&mut path, is_value, |_, _, _| errored = true);
1596 if errored || path.def == Def::Err {
1603 /// resolve_hir_path, but takes a callback in case there was an error
1604 fn resolve_hir_path_cb<F>(&mut self, path: &mut hir::Path, is_value: bool, error_callback: F)
1605 where F: for<'c, 'b> FnOnce(&'c mut Resolver, Span, ResolutionError<'b>)
1607 let namespace = if is_value { ValueNS } else { TypeNS };
1608 let hir::Path { ref segments, span, ref mut def } = *path;
1609 let path: Vec<_> = segments.iter().map(|seg| seg.ident).collect();
1610 // FIXME (Manishearth): Intra doc links won't get warned of epoch changes
1611 match self.resolve_path(None, &path, Some(namespace), true, span, CrateLint::No) {
1612 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
1613 *def = module.def().unwrap(),
1614 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 =>
1615 *def = path_res.base_def(),
1616 PathResult::NonModule(..) => match self.resolve_path(
1624 PathResult::Failed(span, msg, _) => {
1625 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1629 PathResult::Module(ModuleOrUniformRoot::UniformRoot(_)) |
1630 PathResult::Indeterminate => unreachable!(),
1631 PathResult::Failed(span, msg, _) => {
1632 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1638 impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
1639 pub fn new(session: &'a Session,
1643 make_glob_map: MakeGlobMap,
1644 crate_loader: &'a mut CrateLoader<'crateloader>,
1645 arenas: &'a ResolverArenas<'a>)
1646 -> Resolver<'a, 'crateloader> {
1647 let root_def_id = DefId::local(CRATE_DEF_INDEX);
1648 let root_module_kind = ModuleKind::Def(Def::Mod(root_def_id), keywords::Invalid.name());
1649 let graph_root = arenas.alloc_module(ModuleData {
1650 no_implicit_prelude: attr::contains_name(&krate.attrs, "no_implicit_prelude"),
1651 ..ModuleData::new(None, root_module_kind, root_def_id, Mark::root(), krate.span)
1653 let mut module_map = FxHashMap();
1654 module_map.insert(DefId::local(CRATE_DEF_INDEX), graph_root);
1656 let mut definitions = Definitions::new();
1657 DefCollector::new(&mut definitions, Mark::root())
1658 .collect_root(crate_name, session.local_crate_disambiguator());
1660 let mut extern_prelude: FxHashSet<Name> =
1661 session.opts.externs.iter().map(|kv| Symbol::intern(kv.0)).collect();
1662 if !attr::contains_name(&krate.attrs, "no_core") {
1663 if !attr::contains_name(&krate.attrs, "no_std") {
1664 extern_prelude.insert(Symbol::intern("std"));
1666 extern_prelude.insert(Symbol::intern("core"));
1670 let mut invocations = FxHashMap();
1671 invocations.insert(Mark::root(),
1672 arenas.alloc_invocation_data(InvocationData::root(graph_root)));
1674 let mut macro_defs = FxHashMap();
1675 macro_defs.insert(Mark::root(), root_def_id);
1684 // The outermost module has def ID 0; this is not reflected in the
1690 has_self: FxHashSet(),
1691 field_names: FxHashMap(),
1693 determined_imports: Vec::new(),
1694 indeterminate_imports: Vec::new(),
1696 current_module: graph_root,
1698 value_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1699 type_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1700 macro_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1702 label_ribs: Vec::new(),
1704 current_trait_ref: None,
1705 current_self_type: None,
1707 primitive_type_table: PrimitiveTypeTable::new(),
1710 import_map: NodeMap(),
1711 freevars: NodeMap(),
1712 freevars_seen: NodeMap(),
1713 export_map: FxHashMap(),
1714 trait_map: NodeMap(),
1716 block_map: NodeMap(),
1717 extern_module_map: FxHashMap(),
1719 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1720 glob_map: NodeMap(),
1722 used_imports: FxHashSet(),
1723 maybe_unused_trait_imports: NodeSet(),
1724 maybe_unused_extern_crates: Vec::new(),
1726 unused_labels: FxHashMap(),
1728 privacy_errors: Vec::new(),
1729 ambiguity_errors: Vec::new(),
1730 use_injections: Vec::new(),
1731 proc_mac_errors: Vec::new(),
1732 disallowed_shadowing: Vec::new(),
1733 macro_expanded_macro_export_errors: BTreeSet::new(),
1736 dummy_binding: arenas.alloc_name_binding(NameBinding {
1737 kind: NameBindingKind::Def(Def::Err, false),
1738 expansion: Mark::root(),
1740 vis: ty::Visibility::Public,
1744 macro_names: FxHashSet(),
1745 macro_prelude: FxHashMap(),
1746 unshadowable_attrs: FxHashMap(),
1747 all_macros: FxHashMap(),
1748 macro_map: FxHashMap(),
1751 local_macro_def_scopes: FxHashMap(),
1752 name_already_seen: FxHashMap(),
1753 whitelisted_legacy_custom_derives: Vec::new(),
1754 warned_proc_macros: FxHashSet(),
1755 potentially_unused_imports: Vec::new(),
1756 struct_constructors: DefIdMap(),
1757 found_unresolved_macro: false,
1758 unused_macros: FxHashSet(),
1759 current_type_ascription: Vec::new(),
1760 injected_crate: None,
1761 ignore_extern_prelude_feature: false,
1765 pub fn arenas() -> ResolverArenas<'a> {
1767 modules: arena::TypedArena::new(),
1768 local_modules: RefCell::new(Vec::new()),
1769 name_bindings: arena::TypedArena::new(),
1770 import_directives: arena::TypedArena::new(),
1771 name_resolutions: arena::TypedArena::new(),
1772 invocation_data: arena::TypedArena::new(),
1773 legacy_bindings: arena::TypedArena::new(),
1777 /// Runs the function on each namespace.
1778 fn per_ns<F: FnMut(&mut Self, Namespace)>(&mut self, mut f: F) {
1784 fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
1786 match self.macro_defs.get(&ctxt.outer()) {
1787 Some(&def_id) => return def_id,
1788 None => ctxt.remove_mark(),
1793 /// Entry point to crate resolution.
1794 pub fn resolve_crate(&mut self, krate: &Crate) {
1795 ImportResolver { resolver: self }.finalize_imports();
1796 self.current_module = self.graph_root;
1797 self.finalize_current_module_macro_resolutions();
1799 visit::walk_crate(self, krate);
1801 check_unused::check_crate(self, krate);
1802 self.report_errors(krate);
1803 self.crate_loader.postprocess(krate);
1810 normal_ancestor_id: DefId,
1814 let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expansion, span);
1815 self.arenas.alloc_module(module)
1818 fn record_use(&mut self, ident: Ident, ns: Namespace, binding: &'a NameBinding<'a>, span: Span)
1819 -> bool /* true if an error was reported */ {
1820 match binding.kind {
1821 NameBindingKind::Import { directive, binding, ref used }
1824 directive.used.set(true);
1825 self.used_imports.insert((directive.id, ns));
1826 self.add_to_glob_map(directive.id, ident);
1827 self.record_use(ident, ns, binding, span)
1829 NameBindingKind::Import { .. } => false,
1830 NameBindingKind::Ambiguity { b1, b2 } => {
1831 self.ambiguity_errors.push(AmbiguityError {
1832 span, name: ident.name, lexical: false, b1, b2,
1840 fn add_to_glob_map(&mut self, id: NodeId, ident: Ident) {
1841 if self.make_glob_map {
1842 self.glob_map.entry(id).or_default().insert(ident.name);
1846 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1847 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1848 /// `ident` in the first scope that defines it (or None if no scopes define it).
1850 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1851 /// the items are defined in the block. For example,
1854 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1857 /// g(); // This resolves to the local variable `g` since it shadows the item.
1861 /// Invariant: This must only be called during main resolution, not during
1862 /// import resolution.
1863 fn resolve_ident_in_lexical_scope(&mut self,
1866 record_used_id: Option<NodeId>,
1868 -> Option<LexicalScopeBinding<'a>> {
1869 let record_used = record_used_id.is_some();
1870 assert!(ns == TypeNS || ns == ValueNS);
1872 ident.span = if ident.name == keywords::SelfType.name() {
1873 // FIXME(jseyfried) improve `Self` hygiene
1874 ident.span.with_ctxt(SyntaxContext::empty())
1879 ident = ident.modern_and_legacy();
1882 // Walk backwards up the ribs in scope.
1883 let mut module = self.graph_root;
1884 for i in (0 .. self.ribs[ns].len()).rev() {
1885 if let Some(def) = self.ribs[ns][i].bindings.get(&ident).cloned() {
1886 // The ident resolves to a type parameter or local variable.
1887 return Some(LexicalScopeBinding::Def(
1888 self.adjust_local_def(ns, i, def, record_used, path_span)
1892 module = match self.ribs[ns][i].kind {
1893 ModuleRibKind(module) => module,
1894 MacroDefinition(def) if def == self.macro_def(ident.span.ctxt()) => {
1895 // If an invocation of this macro created `ident`, give up on `ident`
1896 // and switch to `ident`'s source from the macro definition.
1897 ident.span.remove_mark();
1903 let item = self.resolve_ident_in_module_unadjusted(
1904 ModuleOrUniformRoot::Module(module),
1911 if let Ok(binding) = item {
1912 // The ident resolves to an item.
1913 return Some(LexicalScopeBinding::Item(binding));
1917 ModuleKind::Block(..) => {}, // We can see through blocks
1922 ident.span = ident.span.modern();
1923 let mut poisoned = None;
1925 let opt_module = if let Some(node_id) = record_used_id {
1926 self.hygienic_lexical_parent_with_compatibility_fallback(module, &mut ident.span,
1927 node_id, &mut poisoned)
1929 self.hygienic_lexical_parent(module, &mut ident.span)
1931 module = unwrap_or!(opt_module, break);
1932 let orig_current_module = self.current_module;
1933 self.current_module = module; // Lexical resolutions can never be a privacy error.
1934 let result = self.resolve_ident_in_module_unadjusted(
1935 ModuleOrUniformRoot::Module(module),
1942 self.current_module = orig_current_module;
1946 if let Some(node_id) = poisoned {
1947 self.session.buffer_lint_with_diagnostic(
1948 lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
1949 node_id, ident.span,
1950 &format!("cannot find {} `{}` in this scope", ns.descr(), ident),
1951 lint::builtin::BuiltinLintDiagnostics::
1952 ProcMacroDeriveResolutionFallback(ident.span),
1955 return Some(LexicalScopeBinding::Item(binding))
1957 Err(Determined) => continue,
1958 Err(Undetermined) =>
1959 span_bug!(ident.span, "undetermined resolution during main resolution pass"),
1963 if !module.no_implicit_prelude {
1964 // `record_used` means that we don't try to load crates during speculative resolution
1965 if record_used && ns == TypeNS && self.extern_prelude.contains(&ident.name) {
1966 if !self.session.features_untracked().extern_prelude &&
1967 !self.ignore_extern_prelude_feature {
1968 feature_err(&self.session.parse_sess, "extern_prelude",
1969 ident.span, GateIssue::Language,
1970 "access to extern crates through prelude is experimental").emit();
1973 let crate_root = self.load_extern_prelude_crate_if_needed(ident);
1975 let binding = (crate_root, ty::Visibility::Public,
1976 ident.span, Mark::root()).to_name_binding(self.arenas);
1977 return Some(LexicalScopeBinding::Item(binding));
1979 if ns == TypeNS && is_known_tool(ident.name) {
1980 let binding = (Def::ToolMod, ty::Visibility::Public,
1981 ident.span, Mark::root()).to_name_binding(self.arenas);
1982 return Some(LexicalScopeBinding::Item(binding));
1984 if let Some(prelude) = self.prelude {
1985 if let Ok(binding) = self.resolve_ident_in_module_unadjusted(
1986 ModuleOrUniformRoot::Module(prelude),
1993 return Some(LexicalScopeBinding::Item(binding));
2001 fn load_extern_prelude_crate_if_needed(&mut self, ident: Ident) -> Module<'a> {
2002 let crate_id = self.crate_loader.process_path_extern(ident.name, ident.span);
2003 let crate_root = self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
2004 self.populate_module_if_necessary(&crate_root);
2008 fn hygienic_lexical_parent(&mut self, module: Module<'a>, span: &mut Span)
2009 -> Option<Module<'a>> {
2010 if !module.expansion.is_descendant_of(span.ctxt().outer()) {
2011 return Some(self.macro_def_scope(span.remove_mark()));
2014 if let ModuleKind::Block(..) = module.kind {
2015 return Some(module.parent.unwrap());
2021 fn hygienic_lexical_parent_with_compatibility_fallback(&mut self, module: Module<'a>,
2022 span: &mut Span, node_id: NodeId,
2023 poisoned: &mut Option<NodeId>)
2024 -> Option<Module<'a>> {
2025 if let module @ Some(..) = self.hygienic_lexical_parent(module, span) {
2029 // We need to support the next case under a deprecation warning
2032 // ---- begin: this comes from a proc macro derive
2033 // mod implementation_details {
2034 // // Note that `MyStruct` is not in scope here.
2035 // impl SomeTrait for MyStruct { ... }
2039 // So we have to fall back to the module's parent during lexical resolution in this case.
2040 if let Some(parent) = module.parent {
2041 // Inner module is inside the macro, parent module is outside of the macro.
2042 if module.expansion != parent.expansion &&
2043 module.expansion.is_descendant_of(parent.expansion) {
2044 // The macro is a proc macro derive
2045 if module.expansion.looks_like_proc_macro_derive() {
2046 if parent.expansion.is_descendant_of(span.ctxt().outer()) {
2047 *poisoned = Some(node_id);
2048 return module.parent;
2057 fn resolve_ident_in_module(&mut self,
2058 module: ModuleOrUniformRoot<'a>,
2063 -> Result<&'a NameBinding<'a>, Determinacy> {
2064 ident.span = ident.span.modern();
2065 let orig_current_module = self.current_module;
2066 if let ModuleOrUniformRoot::Module(module) = module {
2067 if let Some(def) = ident.span.adjust(module.expansion) {
2068 self.current_module = self.macro_def_scope(def);
2071 let result = self.resolve_ident_in_module_unadjusted(
2072 module, ident, ns, false, record_used, span,
2074 self.current_module = orig_current_module;
2078 fn resolve_crate_root(&mut self, ident: Ident) -> Module<'a> {
2079 let mut ctxt = ident.span.ctxt();
2080 let mark = if ident.name == keywords::DollarCrate.name() {
2081 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
2082 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
2083 // as described in `SyntaxContext::apply_mark`, so we ignore prepended modern marks.
2084 // FIXME: This is only a guess and it doesn't work correctly for `macro_rules!`
2085 // definitions actually produced by `macro` and `macro` definitions produced by
2086 // `macro_rules!`, but at least such configurations are not stable yet.
2087 ctxt = ctxt.modern_and_legacy();
2088 let mut iter = ctxt.marks().into_iter().rev().peekable();
2089 let mut result = None;
2090 // Find the last modern mark from the end if it exists.
2091 while let Some(&(mark, transparency)) = iter.peek() {
2092 if transparency == Transparency::Opaque {
2093 result = Some(mark);
2099 // Then find the last legacy mark from the end if it exists.
2100 for (mark, transparency) in iter {
2101 if transparency == Transparency::SemiTransparent {
2102 result = Some(mark);
2109 ctxt = ctxt.modern();
2110 ctxt.adjust(Mark::root())
2112 let module = match mark {
2113 Some(def) => self.macro_def_scope(def),
2114 None => return self.graph_root,
2116 self.get_module(DefId { index: CRATE_DEF_INDEX, ..module.normal_ancestor_id })
2119 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
2120 let mut module = self.get_module(module.normal_ancestor_id);
2121 while module.span.ctxt().modern() != *ctxt {
2122 let parent = module.parent.unwrap_or_else(|| self.macro_def_scope(ctxt.remove_mark()));
2123 module = self.get_module(parent.normal_ancestor_id);
2130 // We maintain a list of value ribs and type ribs.
2132 // Simultaneously, we keep track of the current position in the module
2133 // graph in the `current_module` pointer. When we go to resolve a name in
2134 // the value or type namespaces, we first look through all the ribs and
2135 // then query the module graph. When we resolve a name in the module
2136 // namespace, we can skip all the ribs (since nested modules are not
2137 // allowed within blocks in Rust) and jump straight to the current module
2140 // Named implementations are handled separately. When we find a method
2141 // call, we consult the module node to find all of the implementations in
2142 // scope. This information is lazily cached in the module node. We then
2143 // generate a fake "implementation scope" containing all the
2144 // implementations thus found, for compatibility with old resolve pass.
2146 pub fn with_scope<F, T>(&mut self, id: NodeId, f: F) -> T
2147 where F: FnOnce(&mut Resolver) -> T
2149 let id = self.definitions.local_def_id(id);
2150 let module = self.module_map.get(&id).cloned(); // clones a reference
2151 if let Some(module) = module {
2152 // Move down in the graph.
2153 let orig_module = replace(&mut self.current_module, module);
2154 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(module)));
2155 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(module)));
2157 self.finalize_current_module_macro_resolutions();
2160 self.current_module = orig_module;
2161 self.ribs[ValueNS].pop();
2162 self.ribs[TypeNS].pop();
2169 /// Searches the current set of local scopes for labels. Returns the first non-None label that
2170 /// is returned by the given predicate function
2172 /// Stops after meeting a closure.
2173 fn search_label<P, R>(&self, mut ident: Ident, pred: P) -> Option<R>
2174 where P: Fn(&Rib, Ident) -> Option<R>
2176 for rib in self.label_ribs.iter().rev() {
2179 // If an invocation of this macro created `ident`, give up on `ident`
2180 // and switch to `ident`'s source from the macro definition.
2181 MacroDefinition(def) => {
2182 if def == self.macro_def(ident.span.ctxt()) {
2183 ident.span.remove_mark();
2187 // Do not resolve labels across function boundary
2191 let r = pred(rib, ident);
2199 fn resolve_item(&mut self, item: &Item) {
2200 let name = item.ident.name;
2201 debug!("(resolving item) resolving {}", name);
2204 ItemKind::Ty(_, ref generics) |
2205 ItemKind::Fn(_, _, ref generics, _) |
2206 ItemKind::Existential(_, ref generics) => {
2207 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind),
2208 |this| visit::walk_item(this, item));
2211 ItemKind::Enum(_, ref generics) |
2212 ItemKind::Struct(_, ref generics) |
2213 ItemKind::Union(_, ref generics) => {
2214 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2215 let item_def_id = this.definitions.local_def_id(item.id);
2216 if this.session.features_untracked().self_in_typedefs {
2217 this.with_self_rib(Def::SelfTy(None, Some(item_def_id)), |this| {
2218 visit::walk_item(this, item);
2221 visit::walk_item(this, item);
2226 ItemKind::Impl(.., ref generics, ref opt_trait_ref, ref self_type, ref impl_items) =>
2227 self.resolve_implementation(generics,
2233 ItemKind::Trait(.., ref generics, ref bounds, ref trait_items) => {
2234 // Create a new rib for the trait-wide type parameters.
2235 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2236 let local_def_id = this.definitions.local_def_id(item.id);
2237 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2238 this.visit_generics(generics);
2239 walk_list!(this, visit_param_bound, bounds);
2241 for trait_item in trait_items {
2242 let type_parameters = HasTypeParameters(&trait_item.generics,
2243 TraitOrImplItemRibKind);
2244 this.with_type_parameter_rib(type_parameters, |this| {
2245 match trait_item.node {
2246 TraitItemKind::Const(ref ty, ref default) => {
2249 // Only impose the restrictions of
2250 // ConstRibKind for an actual constant
2251 // expression in a provided default.
2252 if let Some(ref expr) = *default{
2253 this.with_constant_rib(|this| {
2254 this.visit_expr(expr);
2258 TraitItemKind::Method(_, _) => {
2259 visit::walk_trait_item(this, trait_item)
2261 TraitItemKind::Type(..) => {
2262 visit::walk_trait_item(this, trait_item)
2264 TraitItemKind::Macro(_) => {
2265 panic!("unexpanded macro in resolve!")
2274 ItemKind::TraitAlias(ref generics, ref bounds) => {
2275 // Create a new rib for the trait-wide type parameters.
2276 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2277 let local_def_id = this.definitions.local_def_id(item.id);
2278 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2279 this.visit_generics(generics);
2280 walk_list!(this, visit_param_bound, bounds);
2285 ItemKind::Mod(_) | ItemKind::ForeignMod(_) => {
2286 self.with_scope(item.id, |this| {
2287 visit::walk_item(this, item);
2291 ItemKind::Static(ref ty, _, ref expr) |
2292 ItemKind::Const(ref ty, ref expr) => {
2293 self.with_item_rib(|this| {
2295 this.with_constant_rib(|this| {
2296 this.visit_expr(expr);
2301 ItemKind::Use(ref use_tree) => {
2302 // Imports are resolved as global by default, add starting root segment.
2304 segments: use_tree.prefix.make_root().into_iter().collect(),
2305 span: use_tree.span,
2307 self.resolve_use_tree(item.id, use_tree.span, item.id, use_tree, &path);
2310 ItemKind::ExternCrate(_) | ItemKind::MacroDef(..) | ItemKind::GlobalAsm(_) => {
2311 // do nothing, these are just around to be encoded
2314 ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"),
2318 /// For the most part, use trees are desugared into `ImportDirective` instances
2319 /// when building the reduced graph (see `build_reduced_graph_for_use_tree`). But
2320 /// there is one special case we handle here: an empty nested import like
2321 /// `a::{b::{}}`, which desugares into...no import directives.
2322 fn resolve_use_tree(
2327 use_tree: &ast::UseTree,
2330 match use_tree.kind {
2331 ast::UseTreeKind::Nested(ref items) => {
2333 segments: prefix.segments
2335 .chain(use_tree.prefix.segments.iter())
2338 span: prefix.span.to(use_tree.prefix.span),
2341 if items.len() == 0 {
2342 // Resolve prefix of an import with empty braces (issue #28388).
2343 self.smart_resolve_path_with_crate_lint(
2347 PathSource::ImportPrefix,
2348 CrateLint::UsePath { root_id, root_span },
2351 for &(ref tree, nested_id) in items {
2352 self.resolve_use_tree(root_id, root_span, nested_id, tree, &path);
2356 ast::UseTreeKind::Simple(..) => {},
2357 ast::UseTreeKind::Glob => {},
2361 fn with_type_parameter_rib<'b, F>(&'b mut self, type_parameters: TypeParameters<'a, 'b>, f: F)
2362 where F: FnOnce(&mut Resolver)
2364 match type_parameters {
2365 HasTypeParameters(generics, rib_kind) => {
2366 let mut function_type_rib = Rib::new(rib_kind);
2367 let mut seen_bindings = FxHashMap();
2368 for param in &generics.params {
2370 GenericParamKind::Lifetime { .. } => {}
2371 GenericParamKind::Type { .. } => {
2372 let ident = param.ident.modern();
2373 debug!("with_type_parameter_rib: {}", param.id);
2375 if seen_bindings.contains_key(&ident) {
2376 let span = seen_bindings.get(&ident).unwrap();
2377 let err = ResolutionError::NameAlreadyUsedInTypeParameterList(
2381 resolve_error(self, param.ident.span, err);
2383 seen_bindings.entry(ident).or_insert(param.ident.span);
2385 // Plain insert (no renaming).
2386 let def = Def::TyParam(self.definitions.local_def_id(param.id));
2387 function_type_rib.bindings.insert(ident, def);
2388 self.record_def(param.id, PathResolution::new(def));
2392 self.ribs[TypeNS].push(function_type_rib);
2395 NoTypeParameters => {
2402 if let HasTypeParameters(..) = type_parameters {
2403 self.ribs[TypeNS].pop();
2407 fn with_label_rib<F>(&mut self, f: F)
2408 where F: FnOnce(&mut Resolver)
2410 self.label_ribs.push(Rib::new(NormalRibKind));
2412 self.label_ribs.pop();
2415 fn with_item_rib<F>(&mut self, f: F)
2416 where F: FnOnce(&mut Resolver)
2418 self.ribs[ValueNS].push(Rib::new(ItemRibKind));
2419 self.ribs[TypeNS].push(Rib::new(ItemRibKind));
2421 self.ribs[TypeNS].pop();
2422 self.ribs[ValueNS].pop();
2425 fn with_constant_rib<F>(&mut self, f: F)
2426 where F: FnOnce(&mut Resolver)
2428 self.ribs[ValueNS].push(Rib::new(ConstantItemRibKind));
2429 self.label_ribs.push(Rib::new(ConstantItemRibKind));
2431 self.label_ribs.pop();
2432 self.ribs[ValueNS].pop();
2435 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2436 where F: FnOnce(&mut Resolver) -> T
2438 // Handle nested impls (inside fn bodies)
2439 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2440 let result = f(self);
2441 self.current_self_type = previous_value;
2445 /// This is called to resolve a trait reference from an `impl` (i.e. `impl Trait for Foo`)
2446 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
2447 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2449 let mut new_val = None;
2450 let mut new_id = None;
2451 if let Some(trait_ref) = opt_trait_ref {
2452 let path: Vec<_> = trait_ref.path.segments.iter()
2453 .map(|seg| seg.ident)
2455 let def = self.smart_resolve_path_fragment(
2459 trait_ref.path.span,
2460 PathSource::Trait(AliasPossibility::No),
2461 CrateLint::SimplePath(trait_ref.ref_id),
2463 if def != Def::Err {
2464 new_id = Some(def.def_id());
2465 let span = trait_ref.path.span;
2466 if let PathResult::Module(ModuleOrUniformRoot::Module(module)) =
2473 CrateLint::SimplePath(trait_ref.ref_id),
2476 new_val = Some((module, trait_ref.clone()));
2480 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2481 let result = f(self, new_id);
2482 self.current_trait_ref = original_trait_ref;
2486 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2487 where F: FnOnce(&mut Resolver)
2489 let mut self_type_rib = Rib::new(NormalRibKind);
2491 // plain insert (no renaming, types are not currently hygienic....)
2492 self_type_rib.bindings.insert(keywords::SelfType.ident(), self_def);
2493 self.ribs[TypeNS].push(self_type_rib);
2495 self.ribs[TypeNS].pop();
2498 fn resolve_implementation(&mut self,
2499 generics: &Generics,
2500 opt_trait_reference: &Option<TraitRef>,
2503 impl_items: &[ImplItem]) {
2504 // If applicable, create a rib for the type parameters.
2505 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2506 // Dummy self type for better errors if `Self` is used in the trait path.
2507 this.with_self_rib(Def::SelfTy(None, None), |this| {
2508 // Resolve the trait reference, if necessary.
2509 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2510 let item_def_id = this.definitions.local_def_id(item_id);
2511 this.with_self_rib(Def::SelfTy(trait_id, Some(item_def_id)), |this| {
2512 if let Some(trait_ref) = opt_trait_reference.as_ref() {
2513 // Resolve type arguments in the trait path.
2514 visit::walk_trait_ref(this, trait_ref);
2516 // Resolve the self type.
2517 this.visit_ty(self_type);
2518 // Resolve the type parameters.
2519 this.visit_generics(generics);
2520 // Resolve the items within the impl.
2521 this.with_current_self_type(self_type, |this| {
2522 for impl_item in impl_items {
2523 this.resolve_visibility(&impl_item.vis);
2525 // We also need a new scope for the impl item type parameters.
2526 let type_parameters = HasTypeParameters(&impl_item.generics,
2527 TraitOrImplItemRibKind);
2528 this.with_type_parameter_rib(type_parameters, |this| {
2529 use self::ResolutionError::*;
2530 match impl_item.node {
2531 ImplItemKind::Const(..) => {
2532 // If this is a trait impl, ensure the const
2534 this.check_trait_item(impl_item.ident,
2537 |n, s| ConstNotMemberOfTrait(n, s));
2538 this.with_constant_rib(|this|
2539 visit::walk_impl_item(this, impl_item)
2542 ImplItemKind::Method(..) => {
2543 // If this is a trait impl, ensure the method
2545 this.check_trait_item(impl_item.ident,
2548 |n, s| MethodNotMemberOfTrait(n, s));
2550 visit::walk_impl_item(this, impl_item);
2552 ImplItemKind::Type(ref ty) => {
2553 // If this is a trait impl, ensure the type
2555 this.check_trait_item(impl_item.ident,
2558 |n, s| TypeNotMemberOfTrait(n, s));
2562 ImplItemKind::Existential(ref bounds) => {
2563 // If this is a trait impl, ensure the type
2565 this.check_trait_item(impl_item.ident,
2568 |n, s| TypeNotMemberOfTrait(n, s));
2570 for bound in bounds {
2571 this.visit_param_bound(bound);
2574 ImplItemKind::Macro(_) =>
2575 panic!("unexpanded macro in resolve!"),
2586 fn check_trait_item<F>(&mut self, ident: Ident, ns: Namespace, span: Span, err: F)
2587 where F: FnOnce(Name, &str) -> ResolutionError
2589 // If there is a TraitRef in scope for an impl, then the method must be in the
2591 if let Some((module, _)) = self.current_trait_ref {
2592 if self.resolve_ident_in_module(
2593 ModuleOrUniformRoot::Module(module),
2599 let path = &self.current_trait_ref.as_ref().unwrap().1.path;
2600 resolve_error(self, span, err(ident.name, &path_names_to_string(path)));
2605 fn resolve_local(&mut self, local: &Local) {
2606 // Resolve the type.
2607 walk_list!(self, visit_ty, &local.ty);
2609 // Resolve the initializer.
2610 walk_list!(self, visit_expr, &local.init);
2612 // Resolve the pattern.
2613 self.resolve_pattern(&local.pat, PatternSource::Let, &mut FxHashMap());
2616 // build a map from pattern identifiers to binding-info's.
2617 // this is done hygienically. This could arise for a macro
2618 // that expands into an or-pattern where one 'x' was from the
2619 // user and one 'x' came from the macro.
2620 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2621 let mut binding_map = FxHashMap();
2623 pat.walk(&mut |pat| {
2624 if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node {
2625 if sub_pat.is_some() || match self.def_map.get(&pat.id).map(|res| res.base_def()) {
2626 Some(Def::Local(..)) => true,
2629 let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode };
2630 binding_map.insert(ident, binding_info);
2639 // check that all of the arms in an or-pattern have exactly the
2640 // same set of bindings, with the same binding modes for each.
2641 fn check_consistent_bindings(&mut self, pats: &[P<Pat>]) {
2642 if pats.is_empty() {
2646 let mut missing_vars = FxHashMap();
2647 let mut inconsistent_vars = FxHashMap();
2648 for (i, p) in pats.iter().enumerate() {
2649 let map_i = self.binding_mode_map(&p);
2651 for (j, q) in pats.iter().enumerate() {
2656 let map_j = self.binding_mode_map(&q);
2657 for (&key, &binding_i) in &map_i {
2658 if map_j.len() == 0 { // Account for missing bindings when
2659 let binding_error = missing_vars // map_j has none.
2661 .or_insert(BindingError {
2663 origin: BTreeSet::new(),
2664 target: BTreeSet::new(),
2666 binding_error.origin.insert(binding_i.span);
2667 binding_error.target.insert(q.span);
2669 for (&key_j, &binding_j) in &map_j {
2670 match map_i.get(&key_j) {
2671 None => { // missing binding
2672 let binding_error = missing_vars
2674 .or_insert(BindingError {
2676 origin: BTreeSet::new(),
2677 target: BTreeSet::new(),
2679 binding_error.origin.insert(binding_j.span);
2680 binding_error.target.insert(p.span);
2682 Some(binding_i) => { // check consistent binding
2683 if binding_i.binding_mode != binding_j.binding_mode {
2686 .or_insert((binding_j.span, binding_i.span));
2694 let mut missing_vars = missing_vars.iter().collect::<Vec<_>>();
2695 missing_vars.sort();
2696 for (_, v) in missing_vars {
2698 *v.origin.iter().next().unwrap(),
2699 ResolutionError::VariableNotBoundInPattern(v));
2701 let mut inconsistent_vars = inconsistent_vars.iter().collect::<Vec<_>>();
2702 inconsistent_vars.sort();
2703 for (name, v) in inconsistent_vars {
2704 resolve_error(self, v.0, ResolutionError::VariableBoundWithDifferentMode(*name, v.1));
2708 fn resolve_arm(&mut self, arm: &Arm) {
2709 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2711 let mut bindings_list = FxHashMap();
2712 for pattern in &arm.pats {
2713 self.resolve_pattern(&pattern, PatternSource::Match, &mut bindings_list);
2716 // This has to happen *after* we determine which pat_idents are variants
2717 self.check_consistent_bindings(&arm.pats);
2720 Some(ast::Guard::If(ref expr)) => self.visit_expr(expr),
2723 self.visit_expr(&arm.body);
2725 self.ribs[ValueNS].pop();
2728 fn resolve_block(&mut self, block: &Block) {
2729 debug!("(resolving block) entering block");
2730 // Move down in the graph, if there's an anonymous module rooted here.
2731 let orig_module = self.current_module;
2732 let anonymous_module = self.block_map.get(&block.id).cloned(); // clones a reference
2734 let mut num_macro_definition_ribs = 0;
2735 if let Some(anonymous_module) = anonymous_module {
2736 debug!("(resolving block) found anonymous module, moving down");
2737 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2738 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2739 self.current_module = anonymous_module;
2740 self.finalize_current_module_macro_resolutions();
2742 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2745 // Descend into the block.
2746 for stmt in &block.stmts {
2747 if let ast::StmtKind::Item(ref item) = stmt.node {
2748 if let ast::ItemKind::MacroDef(..) = item.node {
2749 num_macro_definition_ribs += 1;
2750 let def = self.definitions.local_def_id(item.id);
2751 self.ribs[ValueNS].push(Rib::new(MacroDefinition(def)));
2752 self.label_ribs.push(Rib::new(MacroDefinition(def)));
2756 self.visit_stmt(stmt);
2760 self.current_module = orig_module;
2761 for _ in 0 .. num_macro_definition_ribs {
2762 self.ribs[ValueNS].pop();
2763 self.label_ribs.pop();
2765 self.ribs[ValueNS].pop();
2766 if anonymous_module.is_some() {
2767 self.ribs[TypeNS].pop();
2769 debug!("(resolving block) leaving block");
2772 fn fresh_binding(&mut self,
2775 outer_pat_id: NodeId,
2776 pat_src: PatternSource,
2777 bindings: &mut FxHashMap<Ident, NodeId>)
2779 // Add the binding to the local ribs, if it
2780 // doesn't already exist in the bindings map. (We
2781 // must not add it if it's in the bindings map
2782 // because that breaks the assumptions later
2783 // passes make about or-patterns.)
2784 let ident = ident.modern_and_legacy();
2785 let mut def = Def::Local(pat_id);
2786 match bindings.get(&ident).cloned() {
2787 Some(id) if id == outer_pat_id => {
2788 // `Variant(a, a)`, error
2792 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2796 Some(..) if pat_src == PatternSource::FnParam => {
2797 // `fn f(a: u8, a: u8)`, error
2801 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2805 Some(..) if pat_src == PatternSource::Match ||
2806 pat_src == PatternSource::IfLet ||
2807 pat_src == PatternSource::WhileLet => {
2808 // `Variant1(a) | Variant2(a)`, ok
2809 // Reuse definition from the first `a`.
2810 def = self.ribs[ValueNS].last_mut().unwrap().bindings[&ident];
2813 span_bug!(ident.span, "two bindings with the same name from \
2814 unexpected pattern source {:?}", pat_src);
2817 // A completely fresh binding, add to the lists if it's valid.
2818 if ident.name != keywords::Invalid.name() {
2819 bindings.insert(ident, outer_pat_id);
2820 self.ribs[ValueNS].last_mut().unwrap().bindings.insert(ident, def);
2825 PathResolution::new(def)
2828 fn resolve_pattern(&mut self,
2830 pat_src: PatternSource,
2831 // Maps idents to the node ID for the
2832 // outermost pattern that binds them.
2833 bindings: &mut FxHashMap<Ident, NodeId>) {
2834 // Visit all direct subpatterns of this pattern.
2835 let outer_pat_id = pat.id;
2836 pat.walk(&mut |pat| {
2838 PatKind::Ident(bmode, ident, ref opt_pat) => {
2839 // First try to resolve the identifier as some existing
2840 // entity, then fall back to a fresh binding.
2841 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS,
2843 .and_then(LexicalScopeBinding::item);
2844 let resolution = binding.map(NameBinding::def).and_then(|def| {
2845 let is_syntactic_ambiguity = opt_pat.is_none() &&
2846 bmode == BindingMode::ByValue(Mutability::Immutable);
2848 Def::StructCtor(_, CtorKind::Const) |
2849 Def::VariantCtor(_, CtorKind::Const) |
2850 Def::Const(..) if is_syntactic_ambiguity => {
2851 // Disambiguate in favor of a unit struct/variant
2852 // or constant pattern.
2853 self.record_use(ident, ValueNS, binding.unwrap(), ident.span);
2854 Some(PathResolution::new(def))
2856 Def::StructCtor(..) | Def::VariantCtor(..) |
2857 Def::Const(..) | Def::Static(..) => {
2858 // This is unambiguously a fresh binding, either syntactically
2859 // (e.g. `IDENT @ PAT` or `ref IDENT`) or because `IDENT` resolves
2860 // to something unusable as a pattern (e.g. constructor function),
2861 // but we still conservatively report an error, see
2862 // issues/33118#issuecomment-233962221 for one reason why.
2866 ResolutionError::BindingShadowsSomethingUnacceptable(
2867 pat_src.descr(), ident.name, binding.unwrap())
2871 Def::Fn(..) | Def::Err => {
2872 // These entities are explicitly allowed
2873 // to be shadowed by fresh bindings.
2877 span_bug!(ident.span, "unexpected definition for an \
2878 identifier in pattern: {:?}", def);
2881 }).unwrap_or_else(|| {
2882 self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings)
2885 self.record_def(pat.id, resolution);
2888 PatKind::TupleStruct(ref path, ..) => {
2889 self.smart_resolve_path(pat.id, None, path, PathSource::TupleStruct);
2892 PatKind::Path(ref qself, ref path) => {
2893 self.smart_resolve_path(pat.id, qself.as_ref(), path, PathSource::Pat);
2896 PatKind::Struct(ref path, ..) => {
2897 self.smart_resolve_path(pat.id, None, path, PathSource::Struct);
2905 visit::walk_pat(self, pat);
2908 // High-level and context dependent path resolution routine.
2909 // Resolves the path and records the resolution into definition map.
2910 // If resolution fails tries several techniques to find likely
2911 // resolution candidates, suggest imports or other help, and report
2912 // errors in user friendly way.
2913 fn smart_resolve_path(&mut self,
2915 qself: Option<&QSelf>,
2919 self.smart_resolve_path_with_crate_lint(id, qself, path, source, CrateLint::SimplePath(id))
2922 /// A variant of `smart_resolve_path` where you also specify extra
2923 /// information about where the path came from; this extra info is
2924 /// sometimes needed for the lint that recommends rewriting
2925 /// absolute paths to `crate`, so that it knows how to frame the
2926 /// suggestion. If you are just resolving a path like `foo::bar`
2927 /// that appears...somewhere, though, then you just want
2928 /// `CrateLint::SimplePath`, which is what `smart_resolve_path`
2929 /// already provides.
2930 fn smart_resolve_path_with_crate_lint(
2933 qself: Option<&QSelf>,
2936 crate_lint: CrateLint
2937 ) -> PathResolution {
2938 let segments = &path.segments.iter()
2939 .map(|seg| seg.ident)
2940 .collect::<Vec<_>>();
2941 self.smart_resolve_path_fragment(id, qself, segments, path.span, source, crate_lint)
2944 fn smart_resolve_path_fragment(&mut self,
2946 qself: Option<&QSelf>,
2950 crate_lint: CrateLint)
2952 let ident_span = path.last().map_or(span, |ident| ident.span);
2953 let ns = source.namespace();
2954 let is_expected = &|def| source.is_expected(def);
2955 let is_enum_variant = &|def| if let Def::Variant(..) = def { true } else { false };
2957 // Base error is amended with one short label and possibly some longer helps/notes.
2958 let report_errors = |this: &mut Self, def: Option<Def>| {
2959 // Make the base error.
2960 let expected = source.descr_expected();
2961 let path_str = names_to_string(path);
2962 let code = source.error_code(def.is_some());
2963 let (base_msg, fallback_label, base_span) = if let Some(def) = def {
2964 (format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str),
2965 format!("not a {}", expected),
2968 let item_str = path[path.len() - 1];
2969 let item_span = path[path.len() - 1].span;
2970 let (mod_prefix, mod_str) = if path.len() == 1 {
2971 (String::new(), "this scope".to_string())
2972 } else if path.len() == 2 && path[0].name == keywords::CrateRoot.name() {
2973 (String::new(), "the crate root".to_string())
2975 let mod_path = &path[..path.len() - 1];
2976 let mod_prefix = match this.resolve_path(None, mod_path, Some(TypeNS),
2977 false, span, CrateLint::No) {
2978 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
2981 }.map_or(String::new(), |def| format!("{} ", def.kind_name()));
2982 (mod_prefix, format!("`{}`", names_to_string(mod_path)))
2984 (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str),
2985 format!("not found in {}", mod_str),
2988 let code = DiagnosticId::Error(code.into());
2989 let mut err = this.session.struct_span_err_with_code(base_span, &base_msg, code);
2991 // Emit special messages for unresolved `Self` and `self`.
2992 if is_self_type(path, ns) {
2993 __diagnostic_used!(E0411);
2994 err.code(DiagnosticId::Error("E0411".into()));
2995 let available_in = if this.session.features_untracked().self_in_typedefs {
2996 "impls, traits, and type definitions"
3000 err.span_label(span, format!("`Self` is only available in {}", available_in));
3001 return (err, Vec::new());
3003 if is_self_value(path, ns) {
3004 __diagnostic_used!(E0424);
3005 err.code(DiagnosticId::Error("E0424".into()));
3006 err.span_label(span, format!("`self` value is only available in \
3007 methods with `self` parameter"));
3008 return (err, Vec::new());
3011 // Try to lookup the name in more relaxed fashion for better error reporting.
3012 let ident = *path.last().unwrap();
3013 let candidates = this.lookup_import_candidates(ident.name, ns, is_expected);
3014 if candidates.is_empty() && is_expected(Def::Enum(DefId::local(CRATE_DEF_INDEX))) {
3015 let enum_candidates =
3016 this.lookup_import_candidates(ident.name, ns, is_enum_variant);
3017 let mut enum_candidates = enum_candidates.iter()
3018 .map(|suggestion| import_candidate_to_paths(&suggestion)).collect::<Vec<_>>();
3019 enum_candidates.sort();
3020 for (sp, variant_path, enum_path) in enum_candidates {
3022 let msg = format!("there is an enum variant `{}`, \
3028 err.span_suggestion_with_applicability(
3030 "you can try using the variant's enum",
3032 Applicability::MachineApplicable,
3037 if path.len() == 1 && this.self_type_is_available(span) {
3038 if let Some(candidate) = this.lookup_assoc_candidate(ident, ns, is_expected) {
3039 let self_is_available = this.self_value_is_available(path[0].span, span);
3041 AssocSuggestion::Field => {
3042 err.span_suggestion_with_applicability(
3045 format!("self.{}", path_str),
3046 Applicability::MachineApplicable,
3048 if !self_is_available {
3049 err.span_label(span, format!("`self` value is only available in \
3050 methods with `self` parameter"));
3053 AssocSuggestion::MethodWithSelf if self_is_available => {
3054 err.span_suggestion_with_applicability(
3057 format!("self.{}", path_str),
3058 Applicability::MachineApplicable,
3061 AssocSuggestion::MethodWithSelf | AssocSuggestion::AssocItem => {
3062 err.span_suggestion_with_applicability(
3065 format!("Self::{}", path_str),
3066 Applicability::MachineApplicable,
3070 return (err, candidates);
3074 let mut levenshtein_worked = false;
3077 if let Some(candidate) = this.lookup_typo_candidate(path, ns, is_expected, span) {
3078 err.span_label(ident_span, format!("did you mean `{}`?", candidate));
3079 levenshtein_worked = true;
3082 // Try context dependent help if relaxed lookup didn't work.
3083 if let Some(def) = def {
3084 match (def, source) {
3085 (Def::Macro(..), _) => {
3086 err.span_label(span, format!("did you mean `{}!(...)`?", path_str));
3087 return (err, candidates);
3089 (Def::TyAlias(..), PathSource::Trait(_)) => {
3090 err.span_label(span, "type aliases cannot be used for traits");
3091 return (err, candidates);
3093 (Def::Mod(..), PathSource::Expr(Some(parent))) => match parent.node {
3094 ExprKind::Field(_, ident) => {
3095 err.span_label(parent.span, format!("did you mean `{}::{}`?",
3097 return (err, candidates);
3099 ExprKind::MethodCall(ref segment, ..) => {
3100 err.span_label(parent.span, format!("did you mean `{}::{}(...)`?",
3101 path_str, segment.ident));
3102 return (err, candidates);
3106 (Def::Enum(..), PathSource::TupleStruct)
3107 | (Def::Enum(..), PathSource::Expr(..)) => {
3108 if let Some(variants) = this.collect_enum_variants(def) {
3109 err.note(&format!("did you mean to use one \
3110 of the following variants?\n{}",
3112 .map(|suggestion| path_names_to_string(suggestion))
3113 .map(|suggestion| format!("- `{}`", suggestion))
3114 .collect::<Vec<_>>()
3118 err.note("did you mean to use one of the enum's variants?");
3120 return (err, candidates);
3122 (Def::Struct(def_id), _) if ns == ValueNS => {
3123 if let Some((ctor_def, ctor_vis))
3124 = this.struct_constructors.get(&def_id).cloned() {
3125 let accessible_ctor = this.is_accessible(ctor_vis);
3126 if is_expected(ctor_def) && !accessible_ctor {
3127 err.span_label(span, format!("constructor is not visible \
3128 here due to private fields"));
3131 // HACK(estebank): find a better way to figure out that this was a
3132 // parser issue where a struct literal is being used on an expression
3133 // where a brace being opened means a block is being started. Look
3134 // ahead for the next text to see if `span` is followed by a `{`.
3135 let cm = this.session.source_map();
3138 sp = cm.next_point(sp);
3139 match cm.span_to_snippet(sp) {
3140 Ok(ref snippet) => {
3141 if snippet.chars().any(|c| { !c.is_whitespace() }) {
3148 let followed_by_brace = match cm.span_to_snippet(sp) {
3149 Ok(ref snippet) if snippet == "{" => true,
3152 if let (PathSource::Expr(None), true) = (source, followed_by_brace) {
3155 format!("did you mean `({} {{ /* fields */ }})`?", path_str),
3160 format!("did you mean `{} {{ /* fields */ }}`?", path_str),
3164 return (err, candidates);
3166 (Def::Union(..), _) |
3167 (Def::Variant(..), _) |
3168 (Def::VariantCtor(_, CtorKind::Fictive), _) if ns == ValueNS => {
3169 err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?",
3171 return (err, candidates);
3173 (Def::SelfTy(..), _) if ns == ValueNS => {
3174 err.span_label(span, fallback_label);
3175 err.note("can't use `Self` as a constructor, you must use the \
3176 implemented struct");
3177 return (err, candidates);
3179 (Def::TyAlias(_), _) | (Def::AssociatedTy(..), _) if ns == ValueNS => {
3180 err.note("can't use a type alias as a constructor");
3181 return (err, candidates);
3188 if !levenshtein_worked {
3189 err.span_label(base_span, fallback_label);
3190 this.type_ascription_suggestion(&mut err, base_span);
3194 let report_errors = |this: &mut Self, def: Option<Def>| {
3195 let (err, candidates) = report_errors(this, def);
3196 let def_id = this.current_module.normal_ancestor_id;
3197 let node_id = this.definitions.as_local_node_id(def_id).unwrap();
3198 let better = def.is_some();
3199 this.use_injections.push(UseError { err, candidates, node_id, better });
3200 err_path_resolution()
3203 let resolution = match self.resolve_qpath_anywhere(
3209 source.defer_to_typeck(),
3210 source.global_by_default(),
3213 Some(resolution) if resolution.unresolved_segments() == 0 => {
3214 if is_expected(resolution.base_def()) || resolution.base_def() == Def::Err {
3217 // Add a temporary hack to smooth the transition to new struct ctor
3218 // visibility rules. See #38932 for more details.
3220 if let Def::Struct(def_id) = resolution.base_def() {
3221 if let Some((ctor_def, ctor_vis))
3222 = self.struct_constructors.get(&def_id).cloned() {
3223 if is_expected(ctor_def) && self.is_accessible(ctor_vis) {
3224 let lint = lint::builtin::LEGACY_CONSTRUCTOR_VISIBILITY;
3225 self.session.buffer_lint(lint, id, span,
3226 "private struct constructors are not usable through \
3227 re-exports in outer modules",
3229 res = Some(PathResolution::new(ctor_def));
3234 res.unwrap_or_else(|| report_errors(self, Some(resolution.base_def())))
3237 Some(resolution) if source.defer_to_typeck() => {
3238 // Not fully resolved associated item `T::A::B` or `<T as Tr>::A::B`
3239 // or `<T>::A::B`. If `B` should be resolved in value namespace then
3240 // it needs to be added to the trait map.
3242 let item_name = *path.last().unwrap();
3243 let traits = self.get_traits_containing_item(item_name, ns);
3244 self.trait_map.insert(id, traits);
3248 _ => report_errors(self, None)
3251 if let PathSource::TraitItem(..) = source {} else {
3252 // Avoid recording definition of `A::B` in `<T as A>::B::C`.
3253 self.record_def(id, resolution);
3258 fn type_ascription_suggestion(&self,
3259 err: &mut DiagnosticBuilder,
3261 debug!("type_ascription_suggetion {:?}", base_span);
3262 let cm = self.session.source_map();
3263 debug!("self.current_type_ascription {:?}", self.current_type_ascription);
3264 if let Some(sp) = self.current_type_ascription.last() {
3266 loop { // try to find the `:`, bail on first non-':'/non-whitespace
3267 sp = cm.next_point(sp);
3268 if let Ok(snippet) = cm.span_to_snippet(sp.to(cm.next_point(sp))) {
3269 debug!("snippet {:?}", snippet);
3270 let line_sp = cm.lookup_char_pos(sp.hi()).line;
3271 let line_base_sp = cm.lookup_char_pos(base_span.lo()).line;
3272 debug!("{:?} {:?}", line_sp, line_base_sp);
3274 err.span_label(base_span,
3275 "expecting a type here because of type ascription");
3276 if line_sp != line_base_sp {
3277 err.span_suggestion_short(sp,
3278 "did you mean to use `;` here instead?",
3282 } else if snippet.trim().len() != 0 {
3283 debug!("tried to find type ascription `:` token, couldn't find it");
3293 fn self_type_is_available(&mut self, span: Span) -> bool {
3294 let binding = self.resolve_ident_in_lexical_scope(keywords::SelfType.ident(),
3295 TypeNS, None, span);
3296 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
3299 fn self_value_is_available(&mut self, self_span: Span, path_span: Span) -> bool {
3300 let ident = Ident::new(keywords::SelfValue.name(), self_span);
3301 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, None, path_span);
3302 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
3305 // Resolve in alternative namespaces if resolution in the primary namespace fails.
3306 fn resolve_qpath_anywhere(&mut self,
3308 qself: Option<&QSelf>,
3310 primary_ns: Namespace,
3312 defer_to_typeck: bool,
3313 global_by_default: bool,
3314 crate_lint: CrateLint)
3315 -> Option<PathResolution> {
3316 let mut fin_res = None;
3317 // FIXME: can't resolve paths in macro namespace yet, macros are
3318 // processed by the little special hack below.
3319 for (i, ns) in [primary_ns, TypeNS, ValueNS, /*MacroNS*/].iter().cloned().enumerate() {
3320 if i == 0 || ns != primary_ns {
3321 match self.resolve_qpath(id, qself, path, ns, span, global_by_default, crate_lint) {
3322 // If defer_to_typeck, then resolution > no resolution,
3323 // otherwise full resolution > partial resolution > no resolution.
3324 Some(res) if res.unresolved_segments() == 0 || defer_to_typeck =>
3326 res => if fin_res.is_none() { fin_res = res },
3330 let is_global = self.macro_prelude.get(&path[0].name).cloned()
3331 .map(|binding| binding.get_macro(self).kind() == MacroKind::Bang).unwrap_or(false);
3332 if primary_ns != MacroNS && (is_global ||
3333 self.macro_names.contains(&path[0].modern())) {
3334 // Return some dummy definition, it's enough for error reporting.
3336 PathResolution::new(Def::Macro(DefId::local(CRATE_DEF_INDEX), MacroKind::Bang))
3342 /// Handles paths that may refer to associated items.
3343 fn resolve_qpath(&mut self,
3345 qself: Option<&QSelf>,
3349 global_by_default: bool,
3350 crate_lint: CrateLint)
3351 -> Option<PathResolution> {
3353 "resolve_qpath(id={:?}, qself={:?}, path={:?}, \
3354 ns={:?}, span={:?}, global_by_default={:?})",
3363 if let Some(qself) = qself {
3364 if qself.position == 0 {
3365 // This is a case like `<T>::B`, where there is no
3366 // trait to resolve. In that case, we leave the `B`
3367 // segment to be resolved by type-check.
3368 return Some(PathResolution::with_unresolved_segments(
3369 Def::Mod(DefId::local(CRATE_DEF_INDEX)), path.len()
3373 // Make sure `A::B` in `<T as A::B>::C` is a trait item.
3375 // Currently, `path` names the full item (`A::B::C`, in
3376 // our example). so we extract the prefix of that that is
3377 // the trait (the slice upto and including
3378 // `qself.position`). And then we recursively resolve that,
3379 // but with `qself` set to `None`.
3381 // However, setting `qself` to none (but not changing the
3382 // span) loses the information about where this path
3383 // *actually* appears, so for the purposes of the crate
3384 // lint we pass along information that this is the trait
3385 // name from a fully qualified path, and this also
3386 // contains the full span (the `CrateLint::QPathTrait`).
3387 let ns = if qself.position + 1 == path.len() { ns } else { TypeNS };
3388 let res = self.smart_resolve_path_fragment(
3391 &path[..qself.position + 1],
3393 PathSource::TraitItem(ns),
3394 CrateLint::QPathTrait {
3396 qpath_span: qself.path_span,
3400 // The remaining segments (the `C` in our example) will
3401 // have to be resolved by type-check, since that requires doing
3402 // trait resolution.
3403 return Some(PathResolution::with_unresolved_segments(
3404 res.base_def(), res.unresolved_segments() + path.len() - qself.position - 1
3408 let result = match self.resolve_path(
3416 PathResult::NonModule(path_res) => path_res,
3417 PathResult::Module(ModuleOrUniformRoot::Module(module)) if !module.is_normal() => {
3418 PathResolution::new(module.def().unwrap())
3420 // In `a(::assoc_item)*` `a` cannot be a module. If `a` does resolve to a module we
3421 // don't report an error right away, but try to fallback to a primitive type.
3422 // So, we are still able to successfully resolve something like
3424 // use std::u8; // bring module u8 in scope
3425 // fn f() -> u8 { // OK, resolves to primitive u8, not to std::u8
3426 // u8::max_value() // OK, resolves to associated function <u8>::max_value,
3427 // // not to non-existent std::u8::max_value
3430 // Such behavior is required for backward compatibility.
3431 // The same fallback is used when `a` resolves to nothing.
3432 PathResult::Module(ModuleOrUniformRoot::Module(_)) |
3433 PathResult::Failed(..)
3434 if (ns == TypeNS || path.len() > 1) &&
3435 self.primitive_type_table.primitive_types
3436 .contains_key(&path[0].name) => {
3437 let prim = self.primitive_type_table.primitive_types[&path[0].name];
3438 PathResolution::with_unresolved_segments(Def::PrimTy(prim), path.len() - 1)
3440 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
3441 PathResolution::new(module.def().unwrap()),
3442 PathResult::Failed(span, msg, false) => {
3443 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
3444 err_path_resolution()
3446 PathResult::Module(ModuleOrUniformRoot::UniformRoot(_)) |
3447 PathResult::Failed(..) => return None,
3448 PathResult::Indeterminate => bug!("indetermined path result in resolve_qpath"),
3451 if path.len() > 1 && !global_by_default && result.base_def() != Def::Err &&
3452 path[0].name != keywords::CrateRoot.name() &&
3453 path[0].name != keywords::DollarCrate.name() {
3454 let unqualified_result = {
3455 match self.resolve_path(
3457 &[*path.last().unwrap()],
3463 PathResult::NonModule(path_res) => path_res.base_def(),
3464 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
3465 module.def().unwrap(),
3466 _ => return Some(result),
3469 if result.base_def() == unqualified_result {
3470 let lint = lint::builtin::UNUSED_QUALIFICATIONS;
3471 self.session.buffer_lint(lint, id, span, "unnecessary qualification")
3480 base_module: Option<ModuleOrUniformRoot<'a>>,
3482 opt_ns: Option<Namespace>, // `None` indicates a module path
3485 crate_lint: CrateLint,
3486 ) -> PathResult<'a> {
3487 let mut module = base_module;
3488 let mut allow_super = true;
3489 let mut second_binding = None;
3492 "resolve_path(path={:?}, opt_ns={:?}, record_used={:?}, \
3493 path_span={:?}, crate_lint={:?})",
3501 for (i, &ident) in path.iter().enumerate() {
3502 debug!("resolve_path ident {} {:?}", i, ident);
3503 let is_last = i == path.len() - 1;
3504 let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
3505 let name = ident.name;
3507 allow_super &= ns == TypeNS &&
3508 (name == keywords::SelfValue.name() ||
3509 name == keywords::Super.name());
3512 if allow_super && name == keywords::Super.name() {
3513 let mut ctxt = ident.span.ctxt().modern();
3514 let self_module = match i {
3515 0 => Some(self.resolve_self(&mut ctxt, self.current_module)),
3517 Some(ModuleOrUniformRoot::Module(module)) => Some(module),
3521 if let Some(self_module) = self_module {
3522 if let Some(parent) = self_module.parent {
3523 module = Some(ModuleOrUniformRoot::Module(
3524 self.resolve_self(&mut ctxt, parent)));
3528 let msg = "There are too many initial `super`s.".to_string();
3529 return PathResult::Failed(ident.span, msg, false);
3532 if name == keywords::SelfValue.name() {
3533 let mut ctxt = ident.span.ctxt().modern();
3534 module = Some(ModuleOrUniformRoot::Module(
3535 self.resolve_self(&mut ctxt, self.current_module)));
3538 if name == keywords::Extern.name() ||
3539 name == keywords::CrateRoot.name() &&
3540 self.session.features_untracked().extern_absolute_paths &&
3541 self.session.rust_2018() {
3542 module = Some(ModuleOrUniformRoot::UniformRoot(name));
3545 if name == keywords::CrateRoot.name() ||
3546 name == keywords::Crate.name() ||
3547 name == keywords::DollarCrate.name() {
3548 // `::a::b`, `crate::a::b` or `$crate::a::b`
3549 module = Some(ModuleOrUniformRoot::Module(
3550 self.resolve_crate_root(ident)));
3556 // Report special messages for path segment keywords in wrong positions.
3557 if ident.is_path_segment_keyword() && i != 0 {
3558 let name_str = if name == keywords::CrateRoot.name() {
3559 "crate root".to_string()
3561 format!("`{}`", name)
3563 let msg = if i == 1 && path[0].name == keywords::CrateRoot.name() {
3564 format!("global paths cannot start with {}", name_str)
3566 format!("{} in paths can only be used in start position", name_str)
3568 return PathResult::Failed(ident.span, msg, false);
3571 let binding = if let Some(module) = module {
3572 self.resolve_ident_in_module(module, ident, ns, record_used, path_span)
3573 } else if opt_ns == Some(MacroNS) {
3574 assert!(ns == TypeNS);
3575 self.resolve_lexical_macro_path_segment(ident, ns, record_used, record_used,
3576 false, path_span).map(|(b, _)| b)
3578 let record_used_id =
3579 if record_used { crate_lint.node_id().or(Some(CRATE_NODE_ID)) } else { None };
3580 match self.resolve_ident_in_lexical_scope(ident, ns, record_used_id, path_span) {
3581 // we found a locally-imported or available item/module
3582 Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
3583 // we found a local variable or type param
3584 Some(LexicalScopeBinding::Def(def))
3585 if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) => {
3586 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3590 _ => Err(if record_used { Determined } else { Undetermined }),
3597 second_binding = Some(binding);
3599 let def = binding.def();
3600 let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(def);
3601 if let Some(next_module) = binding.module() {
3602 module = Some(ModuleOrUniformRoot::Module(next_module));
3603 } else if def == Def::ToolMod && i + 1 != path.len() {
3604 let def = Def::NonMacroAttr(NonMacroAttrKind::Tool);
3605 return PathResult::NonModule(PathResolution::new(def));
3606 } else if def == Def::Err {
3607 return PathResult::NonModule(err_path_resolution());
3608 } else if opt_ns.is_some() && (is_last || maybe_assoc) {
3609 self.lint_if_path_starts_with_module(
3615 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3616 def, path.len() - i - 1
3619 return PathResult::Failed(ident.span,
3620 format!("Not a module `{}`", ident),
3624 Err(Undetermined) => return PathResult::Indeterminate,
3625 Err(Determined) => {
3626 if let Some(ModuleOrUniformRoot::Module(module)) = module {
3627 if opt_ns.is_some() && !module.is_normal() {
3628 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3629 module.def().unwrap(), path.len() - i
3633 let module_def = match module {
3634 Some(ModuleOrUniformRoot::Module(module)) => module.def(),
3637 let msg = if module_def == self.graph_root.def() {
3638 let is_mod = |def| match def { Def::Mod(..) => true, _ => false };
3639 let mut candidates =
3640 self.lookup_import_candidates(name, TypeNS, is_mod);
3641 candidates.sort_by_cached_key(|c| {
3642 (c.path.segments.len(), c.path.to_string())
3644 if let Some(candidate) = candidates.get(0) {
3645 format!("Did you mean `{}`?", candidate.path)
3647 format!("Maybe a missing `extern crate {};`?", ident)
3650 format!("Use of undeclared type or module `{}`", ident)
3652 format!("Could not find `{}` in `{}`", ident, path[i - 1])
3654 return PathResult::Failed(ident.span, msg, is_last);
3659 self.lint_if_path_starts_with_module(crate_lint, path, path_span, second_binding);
3661 PathResult::Module(module.unwrap_or_else(|| {
3662 span_bug!(path_span, "resolve_path: empty(?) path {:?} has no module", path);
3667 fn lint_if_path_starts_with_module(
3669 crate_lint: CrateLint,
3672 second_binding: Option<&NameBinding>,
3674 // In the 2018 edition this lint is a hard error, so nothing to do
3675 if self.session.rust_2018() {
3679 // In the 2015 edition there's no use in emitting lints unless the
3680 // crate's already enabled the feature that we're going to suggest
3681 if !self.session.features_untracked().crate_in_paths {
3685 let (diag_id, diag_span) = match crate_lint {
3686 CrateLint::No => return,
3687 CrateLint::SimplePath(id) => (id, path_span),
3688 CrateLint::UsePath { root_id, root_span } => (root_id, root_span),
3689 CrateLint::QPathTrait { qpath_id, qpath_span } => (qpath_id, qpath_span),
3692 let first_name = match path.get(0) {
3693 Some(ident) => ident.name,
3697 // We're only interested in `use` paths which should start with
3698 // `{{root}}` or `extern` currently.
3699 if first_name != keywords::Extern.name() && first_name != keywords::CrateRoot.name() {
3704 // If this import looks like `crate::...` it's already good
3705 Some(ident) if ident.name == keywords::Crate.name() => return,
3706 // Otherwise go below to see if it's an extern crate
3708 // If the path has length one (and it's `CrateRoot` most likely)
3709 // then we don't know whether we're gonna be importing a crate or an
3710 // item in our crate. Defer this lint to elsewhere
3714 // If the first element of our path was actually resolved to an
3715 // `ExternCrate` (also used for `crate::...`) then no need to issue a
3716 // warning, this looks all good!
3717 if let Some(binding) = second_binding {
3718 if let NameBindingKind::Import { directive: d, .. } = binding.kind {
3719 // Careful: we still want to rewrite paths from
3720 // renamed extern crates.
3721 if let ImportDirectiveSubclass::ExternCrate(None) = d.subclass {
3727 let diag = lint::builtin::BuiltinLintDiagnostics
3728 ::AbsPathWithModule(diag_span);
3729 self.session.buffer_lint_with_diagnostic(
3730 lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
3732 "absolute paths must start with `self`, `super`, \
3733 `crate`, or an external crate name in the 2018 edition",
3737 // Resolve a local definition, potentially adjusting for closures.
3738 fn adjust_local_def(&mut self,
3743 span: Span) -> Def {
3744 let ribs = &self.ribs[ns][rib_index + 1..];
3746 // An invalid forward use of a type parameter from a previous default.
3747 if let ForwardTyParamBanRibKind = self.ribs[ns][rib_index].kind {
3749 resolve_error(self, span, ResolutionError::ForwardDeclaredTyParam);
3751 assert_eq!(def, Def::Err);
3757 span_bug!(span, "unexpected {:?} in bindings", def)
3759 Def::Local(node_id) => {
3762 NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) |
3763 ForwardTyParamBanRibKind => {
3764 // Nothing to do. Continue.
3766 ClosureRibKind(function_id) => {
3769 let seen = self.freevars_seen
3772 if let Some(&index) = seen.get(&node_id) {
3773 def = Def::Upvar(node_id, index, function_id);
3776 let vec = self.freevars
3779 let depth = vec.len();
3780 def = Def::Upvar(node_id, depth, function_id);
3787 seen.insert(node_id, depth);
3790 ItemRibKind | TraitOrImplItemRibKind => {
3791 // This was an attempt to access an upvar inside a
3792 // named function item. This is not allowed, so we
3795 resolve_error(self, span,
3796 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
3800 ConstantItemRibKind => {
3801 // Still doesn't deal with upvars
3803 resolve_error(self, span,
3804 ResolutionError::AttemptToUseNonConstantValueInConstant);
3811 Def::TyParam(..) | Def::SelfTy(..) => {
3814 NormalRibKind | TraitOrImplItemRibKind | ClosureRibKind(..) |
3815 ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind |
3816 ConstantItemRibKind => {
3817 // Nothing to do. Continue.
3820 // This was an attempt to use a type parameter outside
3823 resolve_error(self, span,
3824 ResolutionError::TypeParametersFromOuterFunction(def));
3836 fn lookup_assoc_candidate<FilterFn>(&mut self,
3839 filter_fn: FilterFn)
3840 -> Option<AssocSuggestion>
3841 where FilterFn: Fn(Def) -> bool
3843 fn extract_node_id(t: &Ty) -> Option<NodeId> {
3845 TyKind::Path(None, _) => Some(t.id),
3846 TyKind::Rptr(_, ref mut_ty) => extract_node_id(&mut_ty.ty),
3847 // This doesn't handle the remaining `Ty` variants as they are not
3848 // that commonly the self_type, it might be interesting to provide
3849 // support for those in future.
3854 // Fields are generally expected in the same contexts as locals.
3855 if filter_fn(Def::Local(ast::DUMMY_NODE_ID)) {
3856 if let Some(node_id) = self.current_self_type.as_ref().and_then(extract_node_id) {
3857 // Look for a field with the same name in the current self_type.
3858 if let Some(resolution) = self.def_map.get(&node_id) {
3859 match resolution.base_def() {
3860 Def::Struct(did) | Def::Union(did)
3861 if resolution.unresolved_segments() == 0 => {
3862 if let Some(field_names) = self.field_names.get(&did) {
3863 if field_names.iter().any(|&field_name| ident.name == field_name) {
3864 return Some(AssocSuggestion::Field);
3874 // Look for associated items in the current trait.
3875 if let Some((module, _)) = self.current_trait_ref {
3876 if let Ok(binding) = self.resolve_ident_in_module(
3877 ModuleOrUniformRoot::Module(module),
3883 let def = binding.def();
3885 return Some(if self.has_self.contains(&def.def_id()) {
3886 AssocSuggestion::MethodWithSelf
3888 AssocSuggestion::AssocItem
3897 fn lookup_typo_candidate<FilterFn>(&mut self,
3900 filter_fn: FilterFn,
3903 where FilterFn: Fn(Def) -> bool
3905 let add_module_candidates = |module: Module, names: &mut Vec<Name>| {
3906 for (&(ident, _), resolution) in module.resolutions.borrow().iter() {
3907 if let Some(binding) = resolution.borrow().binding {
3908 if filter_fn(binding.def()) {
3909 names.push(ident.name);
3915 let mut names = Vec::new();
3916 if path.len() == 1 {
3917 // Search in lexical scope.
3918 // Walk backwards up the ribs in scope and collect candidates.
3919 for rib in self.ribs[ns].iter().rev() {
3920 // Locals and type parameters
3921 for (ident, def) in &rib.bindings {
3922 if filter_fn(*def) {
3923 names.push(ident.name);
3927 if let ModuleRibKind(module) = rib.kind {
3928 // Items from this module
3929 add_module_candidates(module, &mut names);
3931 if let ModuleKind::Block(..) = module.kind {
3932 // We can see through blocks
3934 // Items from the prelude
3935 if !module.no_implicit_prelude {
3936 names.extend(self.extern_prelude.iter().cloned());
3937 if let Some(prelude) = self.prelude {
3938 add_module_candidates(prelude, &mut names);
3945 // Add primitive types to the mix
3946 if filter_fn(Def::PrimTy(Bool)) {
3948 self.primitive_type_table.primitive_types.iter().map(|(name, _)| name)
3952 // Search in module.
3953 let mod_path = &path[..path.len() - 1];
3954 if let PathResult::Module(module) = self.resolve_path(None, mod_path, Some(TypeNS),
3955 false, span, CrateLint::No) {
3956 if let ModuleOrUniformRoot::Module(module) = module {
3957 add_module_candidates(module, &mut names);
3962 let name = path[path.len() - 1].name;
3963 // Make sure error reporting is deterministic.
3964 names.sort_by_cached_key(|name| name.as_str());
3965 match find_best_match_for_name(names.iter(), &name.as_str(), None) {
3966 Some(found) if found != name => Some(found),
3971 fn with_resolved_label<F>(&mut self, label: Option<Label>, id: NodeId, f: F)
3972 where F: FnOnce(&mut Resolver)
3974 if let Some(label) = label {
3975 self.unused_labels.insert(id, label.ident.span);
3976 let def = Def::Label(id);
3977 self.with_label_rib(|this| {
3978 let ident = label.ident.modern_and_legacy();
3979 this.label_ribs.last_mut().unwrap().bindings.insert(ident, def);
3987 fn resolve_labeled_block(&mut self, label: Option<Label>, id: NodeId, block: &Block) {
3988 self.with_resolved_label(label, id, |this| this.visit_block(block));
3991 fn resolve_expr(&mut self, expr: &Expr, parent: Option<&Expr>) {
3992 // First, record candidate traits for this expression if it could
3993 // result in the invocation of a method call.
3995 self.record_candidate_traits_for_expr_if_necessary(expr);
3997 // Next, resolve the node.
3999 ExprKind::Path(ref qself, ref path) => {
4000 self.smart_resolve_path(expr.id, qself.as_ref(), path, PathSource::Expr(parent));
4001 visit::walk_expr(self, expr);
4004 ExprKind::Struct(ref path, ..) => {
4005 self.smart_resolve_path(expr.id, None, path, PathSource::Struct);
4006 visit::walk_expr(self, expr);
4009 ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => {
4010 let def = self.search_label(label.ident, |rib, ident| {
4011 rib.bindings.get(&ident.modern_and_legacy()).cloned()
4015 // Search again for close matches...
4016 // Picks the first label that is "close enough", which is not necessarily
4017 // the closest match
4018 let close_match = self.search_label(label.ident, |rib, ident| {
4019 let names = rib.bindings.iter().map(|(id, _)| &id.name);
4020 find_best_match_for_name(names, &*ident.as_str(), None)
4022 self.record_def(expr.id, err_path_resolution());
4025 ResolutionError::UndeclaredLabel(&label.ident.as_str(),
4028 Some(Def::Label(id)) => {
4029 // Since this def is a label, it is never read.
4030 self.record_def(expr.id, PathResolution::new(Def::Label(id)));
4031 self.unused_labels.remove(&id);
4034 span_bug!(expr.span, "label wasn't mapped to a label def!");
4038 // visit `break` argument if any
4039 visit::walk_expr(self, expr);
4042 ExprKind::IfLet(ref pats, ref subexpression, ref if_block, ref optional_else) => {
4043 self.visit_expr(subexpression);
4045 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
4046 let mut bindings_list = FxHashMap();
4048 self.resolve_pattern(pat, PatternSource::IfLet, &mut bindings_list);
4050 // This has to happen *after* we determine which pat_idents are variants
4051 self.check_consistent_bindings(pats);
4052 self.visit_block(if_block);
4053 self.ribs[ValueNS].pop();
4055 optional_else.as_ref().map(|expr| self.visit_expr(expr));
4058 ExprKind::Loop(ref block, label) => self.resolve_labeled_block(label, expr.id, &block),
4060 ExprKind::While(ref subexpression, ref block, label) => {
4061 self.with_resolved_label(label, expr.id, |this| {
4062 this.visit_expr(subexpression);
4063 this.visit_block(block);
4067 ExprKind::WhileLet(ref pats, ref subexpression, ref block, label) => {
4068 self.with_resolved_label(label, expr.id, |this| {
4069 this.visit_expr(subexpression);
4070 this.ribs[ValueNS].push(Rib::new(NormalRibKind));
4071 let mut bindings_list = FxHashMap();
4073 this.resolve_pattern(pat, PatternSource::WhileLet, &mut bindings_list);
4075 // This has to happen *after* we determine which pat_idents are variants
4076 this.check_consistent_bindings(pats);
4077 this.visit_block(block);
4078 this.ribs[ValueNS].pop();
4082 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, label) => {
4083 self.visit_expr(subexpression);
4084 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
4085 self.resolve_pattern(pattern, PatternSource::For, &mut FxHashMap());
4087 self.resolve_labeled_block(label, expr.id, block);
4089 self.ribs[ValueNS].pop();
4092 ExprKind::Block(ref block, label) => self.resolve_labeled_block(label, block.id, block),
4094 // Equivalent to `visit::walk_expr` + passing some context to children.
4095 ExprKind::Field(ref subexpression, _) => {
4096 self.resolve_expr(subexpression, Some(expr));
4098 ExprKind::MethodCall(ref segment, ref arguments) => {
4099 let mut arguments = arguments.iter();
4100 self.resolve_expr(arguments.next().unwrap(), Some(expr));
4101 for argument in arguments {
4102 self.resolve_expr(argument, None);
4104 self.visit_path_segment(expr.span, segment);
4107 ExprKind::Call(ref callee, ref arguments) => {
4108 self.resolve_expr(callee, Some(expr));
4109 for argument in arguments {
4110 self.resolve_expr(argument, None);
4113 ExprKind::Type(ref type_expr, _) => {
4114 self.current_type_ascription.push(type_expr.span);
4115 visit::walk_expr(self, expr);
4116 self.current_type_ascription.pop();
4118 // Resolve the body of async exprs inside the async closure to which they desugar
4119 ExprKind::Async(_, async_closure_id, ref block) => {
4120 let rib_kind = ClosureRibKind(async_closure_id);
4121 self.ribs[ValueNS].push(Rib::new(rib_kind));
4122 self.label_ribs.push(Rib::new(rib_kind));
4123 self.visit_block(&block);
4124 self.label_ribs.pop();
4125 self.ribs[ValueNS].pop();
4127 // `async |x| ...` gets desugared to `|x| future_from_generator(|| ...)`, so we need to
4128 // resolve the arguments within the proper scopes so that usages of them inside the
4129 // closure are detected as upvars rather than normal closure arg usages.
4131 _, IsAsync::Async { closure_id: inner_closure_id, .. }, _,
4132 ref fn_decl, ref body, _span,
4134 let rib_kind = ClosureRibKind(expr.id);
4135 self.ribs[ValueNS].push(Rib::new(rib_kind));
4136 self.label_ribs.push(Rib::new(rib_kind));
4137 // Resolve arguments:
4138 let mut bindings_list = FxHashMap();
4139 for argument in &fn_decl.inputs {
4140 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
4141 self.visit_ty(&argument.ty);
4143 // No need to resolve return type-- the outer closure return type is
4144 // FunctionRetTy::Default
4146 // Now resolve the inner closure
4148 let rib_kind = ClosureRibKind(inner_closure_id);
4149 self.ribs[ValueNS].push(Rib::new(rib_kind));
4150 self.label_ribs.push(Rib::new(rib_kind));
4151 // No need to resolve arguments: the inner closure has none.
4152 // Resolve the return type:
4153 visit::walk_fn_ret_ty(self, &fn_decl.output);
4155 self.visit_expr(body);
4156 self.label_ribs.pop();
4157 self.ribs[ValueNS].pop();
4159 self.label_ribs.pop();
4160 self.ribs[ValueNS].pop();
4163 visit::walk_expr(self, expr);
4168 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
4170 ExprKind::Field(_, ident) => {
4171 // FIXME(#6890): Even though you can't treat a method like a
4172 // field, we need to add any trait methods we find that match
4173 // the field name so that we can do some nice error reporting
4174 // later on in typeck.
4175 let traits = self.get_traits_containing_item(ident, ValueNS);
4176 self.trait_map.insert(expr.id, traits);
4178 ExprKind::MethodCall(ref segment, ..) => {
4179 debug!("(recording candidate traits for expr) recording traits for {}",
4181 let traits = self.get_traits_containing_item(segment.ident, ValueNS);
4182 self.trait_map.insert(expr.id, traits);
4190 fn get_traits_containing_item(&mut self, mut ident: Ident, ns: Namespace)
4191 -> Vec<TraitCandidate> {
4192 debug!("(getting traits containing item) looking for '{}'", ident.name);
4194 let mut found_traits = Vec::new();
4195 // Look for the current trait.
4196 if let Some((module, _)) = self.current_trait_ref {
4197 if self.resolve_ident_in_module(
4198 ModuleOrUniformRoot::Module(module),
4204 let def_id = module.def_id().unwrap();
4205 found_traits.push(TraitCandidate { def_id: def_id, import_id: None });
4209 ident.span = ident.span.modern();
4210 let mut search_module = self.current_module;
4212 self.get_traits_in_module_containing_item(ident, ns, search_module, &mut found_traits);
4213 search_module = unwrap_or!(
4214 self.hygienic_lexical_parent(search_module, &mut ident.span), break
4218 if let Some(prelude) = self.prelude {
4219 if !search_module.no_implicit_prelude {
4220 self.get_traits_in_module_containing_item(ident, ns, prelude, &mut found_traits);
4227 fn get_traits_in_module_containing_item(&mut self,
4231 found_traits: &mut Vec<TraitCandidate>) {
4232 assert!(ns == TypeNS || ns == ValueNS);
4233 let mut traits = module.traits.borrow_mut();
4234 if traits.is_none() {
4235 let mut collected_traits = Vec::new();
4236 module.for_each_child(|name, ns, binding| {
4237 if ns != TypeNS { return }
4238 if let Def::Trait(_) = binding.def() {
4239 collected_traits.push((name, binding));
4242 *traits = Some(collected_traits.into_boxed_slice());
4245 for &(trait_name, binding) in traits.as_ref().unwrap().iter() {
4246 let module = binding.module().unwrap();
4247 let mut ident = ident;
4248 if ident.span.glob_adjust(module.expansion, binding.span.ctxt().modern()).is_none() {
4251 if self.resolve_ident_in_module_unadjusted(
4252 ModuleOrUniformRoot::Module(module),
4259 let import_id = match binding.kind {
4260 NameBindingKind::Import { directive, .. } => {
4261 self.maybe_unused_trait_imports.insert(directive.id);
4262 self.add_to_glob_map(directive.id, trait_name);
4267 let trait_def_id = module.def_id().unwrap();
4268 found_traits.push(TraitCandidate { def_id: trait_def_id, import_id: import_id });
4273 fn lookup_import_candidates_from_module<FilterFn>(&mut self,
4275 namespace: Namespace,
4276 start_module: &'a ModuleData<'a>,
4278 filter_fn: FilterFn)
4279 -> Vec<ImportSuggestion>
4280 where FilterFn: Fn(Def) -> bool
4282 let mut candidates = Vec::new();
4283 let mut worklist = Vec::new();
4284 let mut seen_modules = FxHashSet();
4285 let not_local_module = crate_name != keywords::Crate.ident();
4286 worklist.push((start_module, Vec::<ast::PathSegment>::new(), not_local_module));
4288 while let Some((in_module,
4290 in_module_is_extern)) = worklist.pop() {
4291 self.populate_module_if_necessary(in_module);
4293 // We have to visit module children in deterministic order to avoid
4294 // instabilities in reported imports (#43552).
4295 in_module.for_each_child_stable(|ident, ns, name_binding| {
4296 // avoid imports entirely
4297 if name_binding.is_import() && !name_binding.is_extern_crate() { return; }
4298 // avoid non-importable candidates as well
4299 if !name_binding.is_importable() { return; }
4301 // collect results based on the filter function
4302 if ident.name == lookup_name && ns == namespace {
4303 if filter_fn(name_binding.def()) {
4305 let mut segms = path_segments.clone();
4306 if self.session.rust_2018() {
4307 // crate-local absolute paths start with `crate::` in edition 2018
4308 // FIXME: may also be stabilized for Rust 2015 (Issues #45477, #44660)
4310 0, ast::PathSegment::from_ident(crate_name)
4314 segms.push(ast::PathSegment::from_ident(ident));
4316 span: name_binding.span,
4319 // the entity is accessible in the following cases:
4320 // 1. if it's defined in the same crate, it's always
4321 // accessible (since private entities can be made public)
4322 // 2. if it's defined in another crate, it's accessible
4323 // only if both the module is public and the entity is
4324 // declared as public (due to pruning, we don't explore
4325 // outside crate private modules => no need to check this)
4326 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
4327 candidates.push(ImportSuggestion { path: path });
4332 // collect submodules to explore
4333 if let Some(module) = name_binding.module() {
4335 let mut path_segments = path_segments.clone();
4336 path_segments.push(ast::PathSegment::from_ident(ident));
4338 let is_extern_crate_that_also_appears_in_prelude =
4339 name_binding.is_extern_crate() &&
4340 self.session.rust_2018();
4342 let is_visible_to_user =
4343 !in_module_is_extern || name_binding.vis == ty::Visibility::Public;
4345 if !is_extern_crate_that_also_appears_in_prelude && is_visible_to_user {
4346 // add the module to the lookup
4347 let is_extern = in_module_is_extern || name_binding.is_extern_crate();
4348 if seen_modules.insert(module.def_id().unwrap()) {
4349 worklist.push((module, path_segments, is_extern));
4359 /// When name resolution fails, this method can be used to look up candidate
4360 /// entities with the expected name. It allows filtering them using the
4361 /// supplied predicate (which should be used to only accept the types of
4362 /// definitions expected e.g. traits). The lookup spans across all crates.
4364 /// NOTE: The method does not look into imports, but this is not a problem,
4365 /// since we report the definitions (thus, the de-aliased imports).
4366 fn lookup_import_candidates<FilterFn>(&mut self,
4368 namespace: Namespace,
4369 filter_fn: FilterFn)
4370 -> Vec<ImportSuggestion>
4371 where FilterFn: Fn(Def) -> bool
4373 let mut suggestions = vec![];
4376 self.lookup_import_candidates_from_module(
4377 lookup_name, namespace, self.graph_root, keywords::Crate.ident(), &filter_fn
4381 if self.session.features_untracked().extern_prelude {
4382 let extern_prelude_names = self.extern_prelude.clone();
4383 for &krate_name in extern_prelude_names.iter() {
4384 let krate_ident = Ident::with_empty_ctxt(krate_name);
4385 let external_prelude_module = self.load_extern_prelude_crate_if_needed(krate_ident);
4388 self.lookup_import_candidates_from_module(
4389 lookup_name, namespace, external_prelude_module, krate_ident, &filter_fn
4398 fn find_module(&mut self,
4400 -> Option<(Module<'a>, ImportSuggestion)>
4402 let mut result = None;
4403 let mut worklist = Vec::new();
4404 let mut seen_modules = FxHashSet();
4405 worklist.push((self.graph_root, Vec::new()));
4407 while let Some((in_module, path_segments)) = worklist.pop() {
4408 // abort if the module is already found
4409 if result.is_some() { break; }
4411 self.populate_module_if_necessary(in_module);
4413 in_module.for_each_child_stable(|ident, _, name_binding| {
4414 // abort if the module is already found or if name_binding is private external
4415 if result.is_some() || !name_binding.vis.is_visible_locally() {
4418 if let Some(module) = name_binding.module() {
4420 let mut path_segments = path_segments.clone();
4421 path_segments.push(ast::PathSegment::from_ident(ident));
4422 if module.def() == Some(module_def) {
4424 span: name_binding.span,
4425 segments: path_segments,
4427 result = Some((module, ImportSuggestion { path: path }));
4429 // add the module to the lookup
4430 if seen_modules.insert(module.def_id().unwrap()) {
4431 worklist.push((module, path_segments));
4441 fn collect_enum_variants(&mut self, enum_def: Def) -> Option<Vec<Path>> {
4442 if let Def::Enum(..) = enum_def {} else {
4443 panic!("Non-enum def passed to collect_enum_variants: {:?}", enum_def)
4446 self.find_module(enum_def).map(|(enum_module, enum_import_suggestion)| {
4447 self.populate_module_if_necessary(enum_module);
4449 let mut variants = Vec::new();
4450 enum_module.for_each_child_stable(|ident, _, name_binding| {
4451 if let Def::Variant(..) = name_binding.def() {
4452 let mut segms = enum_import_suggestion.path.segments.clone();
4453 segms.push(ast::PathSegment::from_ident(ident));
4454 variants.push(Path {
4455 span: name_binding.span,
4464 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
4465 debug!("(recording def) recording {:?} for {}", resolution, node_id);
4466 if let Some(prev_res) = self.def_map.insert(node_id, resolution) {
4467 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
4471 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
4473 ast::VisibilityKind::Public => ty::Visibility::Public,
4474 ast::VisibilityKind::Crate(..) => {
4475 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
4477 ast::VisibilityKind::Inherited => {
4478 ty::Visibility::Restricted(self.current_module.normal_ancestor_id)
4480 ast::VisibilityKind::Restricted { ref path, id, .. } => {
4481 // Visibilities are resolved as global by default, add starting root segment.
4482 let segments = path.make_root().iter().chain(path.segments.iter())
4483 .map(|seg| seg.ident)
4484 .collect::<Vec<_>>();
4485 let def = self.smart_resolve_path_fragment(
4490 PathSource::Visibility,
4491 CrateLint::SimplePath(id),
4493 if def == Def::Err {
4494 ty::Visibility::Public
4496 let vis = ty::Visibility::Restricted(def.def_id());
4497 if self.is_accessible(vis) {
4500 self.session.span_err(path.span, "visibilities can only be restricted \
4501 to ancestor modules");
4502 ty::Visibility::Public
4509 fn is_accessible(&self, vis: ty::Visibility) -> bool {
4510 vis.is_accessible_from(self.current_module.normal_ancestor_id, self)
4513 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
4514 vis.is_accessible_from(module.normal_ancestor_id, self)
4517 fn report_ambiguity_error(
4518 &self, name: Name, span: Span, _lexical: bool,
4519 def1: Def, is_import1: bool, is_glob1: bool, from_expansion1: bool, span1: Span,
4520 def2: Def, is_import2: bool, _is_glob2: bool, _from_expansion2: bool, span2: Span,
4522 let participle = |is_import: bool| if is_import { "imported" } else { "defined" };
4523 let msg1 = format!("`{}` could refer to the name {} here", name, participle(is_import1));
4525 format!("`{}` could also refer to the name {} here", name, participle(is_import2));
4526 let note = if from_expansion1 {
4527 Some(if let Def::Macro(..) = def1 {
4528 format!("macro-expanded {} do not shadow",
4529 if is_import1 { "macro imports" } else { "macros" })
4531 format!("macro-expanded {} do not shadow when used in a macro invocation path",
4532 if is_import1 { "imports" } else { "items" })
4534 } else if is_glob1 {
4535 Some(format!("consider adding an explicit import of `{}` to disambiguate", name))
4540 let mut err = struct_span_err!(self.session, span, E0659, "`{}` is ambiguous", name);
4541 err.span_note(span1, &msg1);
4543 Def::Macro(..) if span2.is_dummy() =>
4544 err.note(&format!("`{}` is also a builtin macro", name)),
4545 _ => err.span_note(span2, &msg2),
4547 if let Some(note) = note {
4553 fn report_errors(&mut self, krate: &Crate) {
4554 self.report_shadowing_errors();
4555 self.report_with_use_injections(krate);
4556 self.report_proc_macro_import(krate);
4557 let mut reported_spans = FxHashSet();
4559 for &(span_use, span_def) in &self.macro_expanded_macro_export_errors {
4560 let msg = "macro-expanded `macro_export` macros from the current crate \
4561 cannot be referred to by absolute paths";
4562 self.session.buffer_lint_with_diagnostic(
4563 lint::builtin::MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS,
4564 CRATE_NODE_ID, span_use, msg,
4565 lint::builtin::BuiltinLintDiagnostics::
4566 MacroExpandedMacroExportsAccessedByAbsolutePaths(span_def),
4570 for &AmbiguityError { span, name, b1, b2, lexical } in &self.ambiguity_errors {
4571 if reported_spans.insert(span) {
4572 self.report_ambiguity_error(
4573 name, span, lexical,
4574 b1.def(), b1.is_import(), b1.is_glob_import(),
4575 b1.expansion != Mark::root(), b1.span,
4576 b2.def(), b2.is_import(), b2.is_glob_import(),
4577 b2.expansion != Mark::root(), b2.span,
4582 for &PrivacyError(span, name, binding) in &self.privacy_errors {
4583 if !reported_spans.insert(span) { continue }
4584 span_err!(self.session, span, E0603, "{} `{}` is private", binding.descr(), name);
4588 fn report_with_use_injections(&mut self, krate: &Crate) {
4589 for UseError { mut err, candidates, node_id, better } in self.use_injections.drain(..) {
4590 let (span, found_use) = UsePlacementFinder::check(krate, node_id);
4591 if !candidates.is_empty() {
4592 show_candidates(&mut err, span, &candidates, better, found_use);
4598 fn report_shadowing_errors(&mut self) {
4599 let mut reported_errors = FxHashSet();
4600 for binding in replace(&mut self.disallowed_shadowing, Vec::new()) {
4601 if self.resolve_legacy_scope(&binding.parent, binding.ident, false).is_some() &&
4602 reported_errors.insert((binding.ident, binding.span)) {
4603 let msg = format!("`{}` is already in scope", binding.ident);
4604 self.session.struct_span_err(binding.span, &msg)
4605 .note("macro-expanded `macro_rules!`s may not shadow \
4606 existing macros (see RFC 1560)")
4612 fn report_conflict<'b>(&mut self,
4616 new_binding: &NameBinding<'b>,
4617 old_binding: &NameBinding<'b>) {
4618 // Error on the second of two conflicting names
4619 if old_binding.span.lo() > new_binding.span.lo() {
4620 return self.report_conflict(parent, ident, ns, old_binding, new_binding);
4623 let container = match parent.kind {
4624 ModuleKind::Def(Def::Mod(_), _) => "module",
4625 ModuleKind::Def(Def::Trait(_), _) => "trait",
4626 ModuleKind::Block(..) => "block",
4630 let old_noun = match old_binding.is_import() {
4632 false => "definition",
4635 let new_participle = match new_binding.is_import() {
4640 let (name, span) = (ident.name, self.session.source_map().def_span(new_binding.span));
4642 if let Some(s) = self.name_already_seen.get(&name) {
4648 let old_kind = match (ns, old_binding.module()) {
4649 (ValueNS, _) => "value",
4650 (MacroNS, _) => "macro",
4651 (TypeNS, _) if old_binding.is_extern_crate() => "extern crate",
4652 (TypeNS, Some(module)) if module.is_normal() => "module",
4653 (TypeNS, Some(module)) if module.is_trait() => "trait",
4654 (TypeNS, _) => "type",
4657 let msg = format!("the name `{}` is defined multiple times", name);
4659 let mut err = match (old_binding.is_extern_crate(), new_binding.is_extern_crate()) {
4660 (true, true) => struct_span_err!(self.session, span, E0259, "{}", msg),
4661 (true, _) | (_, true) => match new_binding.is_import() && old_binding.is_import() {
4662 true => struct_span_err!(self.session, span, E0254, "{}", msg),
4663 false => struct_span_err!(self.session, span, E0260, "{}", msg),
4665 _ => match (old_binding.is_import(), new_binding.is_import()) {
4666 (false, false) => struct_span_err!(self.session, span, E0428, "{}", msg),
4667 (true, true) => struct_span_err!(self.session, span, E0252, "{}", msg),
4668 _ => struct_span_err!(self.session, span, E0255, "{}", msg),
4672 err.note(&format!("`{}` must be defined only once in the {} namespace of this {}",
4677 err.span_label(span, format!("`{}` re{} here", name, new_participle));
4678 if !old_binding.span.is_dummy() {
4679 err.span_label(self.session.source_map().def_span(old_binding.span),
4680 format!("previous {} of the {} `{}` here", old_noun, old_kind, name));
4683 // See https://github.com/rust-lang/rust/issues/32354
4684 if old_binding.is_import() || new_binding.is_import() {
4685 let binding = if new_binding.is_import() && !new_binding.span.is_dummy() {
4691 let cm = self.session.source_map();
4692 let rename_msg = "You can use `as` to change the binding name of the import";
4694 if let (Ok(snippet), false) = (cm.span_to_snippet(binding.span),
4695 binding.is_renamed_extern_crate()) {
4696 let suggested_name = if name.as_str().chars().next().unwrap().is_uppercase() {
4697 format!("Other{}", name)
4699 format!("other_{}", name)
4702 err.span_suggestion_with_applicability(
4705 if snippet.ends_with(';') {
4706 format!("{} as {};", &snippet[..snippet.len() - 1], suggested_name)
4708 format!("{} as {}", snippet, suggested_name)
4710 Applicability::MachineApplicable,
4713 err.span_label(binding.span, rename_msg);
4718 self.name_already_seen.insert(name, span);
4722 fn is_self_type(path: &[Ident], namespace: Namespace) -> bool {
4723 namespace == TypeNS && path.len() == 1 && path[0].name == keywords::SelfType.name()
4726 fn is_self_value(path: &[Ident], namespace: Namespace) -> bool {
4727 namespace == ValueNS && path.len() == 1 && path[0].name == keywords::SelfValue.name()
4730 fn names_to_string(idents: &[Ident]) -> String {
4731 let mut result = String::new();
4732 for (i, ident) in idents.iter()
4733 .filter(|ident| ident.name != keywords::CrateRoot.name())
4736 result.push_str("::");
4738 result.push_str(&ident.as_str());
4743 fn path_names_to_string(path: &Path) -> String {
4744 names_to_string(&path.segments.iter()
4745 .map(|seg| seg.ident)
4746 .collect::<Vec<_>>())
4749 /// Get the path for an enum and the variant from an `ImportSuggestion` for an enum variant.
4750 fn import_candidate_to_paths(suggestion: &ImportSuggestion) -> (Span, String, String) {
4751 let variant_path = &suggestion.path;
4752 let variant_path_string = path_names_to_string(variant_path);
4754 let path_len = suggestion.path.segments.len();
4755 let enum_path = ast::Path {
4756 span: suggestion.path.span,
4757 segments: suggestion.path.segments[0..path_len - 1].to_vec(),
4759 let enum_path_string = path_names_to_string(&enum_path);
4761 (suggestion.path.span, variant_path_string, enum_path_string)
4765 /// When an entity with a given name is not available in scope, we search for
4766 /// entities with that name in all crates. This method allows outputting the
4767 /// results of this search in a programmer-friendly way
4768 fn show_candidates(err: &mut DiagnosticBuilder,
4769 // This is `None` if all placement locations are inside expansions
4771 candidates: &[ImportSuggestion],
4775 // we want consistent results across executions, but candidates are produced
4776 // by iterating through a hash map, so make sure they are ordered:
4777 let mut path_strings: Vec<_> =
4778 candidates.into_iter().map(|c| path_names_to_string(&c.path)).collect();
4779 path_strings.sort();
4781 let better = if better { "better " } else { "" };
4782 let msg_diff = match path_strings.len() {
4783 1 => " is found in another module, you can import it",
4784 _ => "s are found in other modules, you can import them",
4786 let msg = format!("possible {}candidate{} into scope", better, msg_diff);
4788 if let Some(span) = span {
4789 for candidate in &mut path_strings {
4790 // produce an additional newline to separate the new use statement
4791 // from the directly following item.
4792 let additional_newline = if found_use {
4797 *candidate = format!("use {};\n{}", candidate, additional_newline);
4800 err.span_suggestions(span, &msg, path_strings);
4804 for candidate in path_strings {
4806 msg.push_str(&candidate);
4811 /// A somewhat inefficient routine to obtain the name of a module.
4812 fn module_to_string(module: Module) -> Option<String> {
4813 let mut names = Vec::new();
4815 fn collect_mod(names: &mut Vec<Ident>, module: Module) {
4816 if let ModuleKind::Def(_, name) = module.kind {
4817 if let Some(parent) = module.parent {
4818 names.push(Ident::with_empty_ctxt(name));
4819 collect_mod(names, parent);
4822 // danger, shouldn't be ident?
4823 names.push(Ident::from_str("<opaque>"));
4824 collect_mod(names, module.parent.unwrap());
4827 collect_mod(&mut names, module);
4829 if names.is_empty() {
4832 Some(names_to_string(&names.into_iter()
4834 .collect::<Vec<_>>()))
4837 fn err_path_resolution() -> PathResolution {
4838 PathResolution::new(Def::Err)
4841 #[derive(PartialEq,Copy, Clone)]
4842 pub enum MakeGlobMap {
4847 #[derive(Copy, Clone, Debug)]
4849 /// Do not issue the lint
4852 /// This lint applies to some random path like `impl ::foo::Bar`
4853 /// or whatever. In this case, we can take the span of that path.
4856 /// This lint comes from a `use` statement. In this case, what we
4857 /// care about really is the *root* `use` statement; e.g., if we
4858 /// have nested things like `use a::{b, c}`, we care about the
4860 UsePath { root_id: NodeId, root_span: Span },
4862 /// This is the "trait item" from a fully qualified path. For example,
4863 /// we might be resolving `X::Y::Z` from a path like `<T as X::Y>::Z`.
4864 /// The `path_span` is the span of the to the trait itself (`X::Y`).
4865 QPathTrait { qpath_id: NodeId, qpath_span: Span },
4869 fn node_id(&self) -> Option<NodeId> {
4871 CrateLint::No => None,
4872 CrateLint::SimplePath(id) |
4873 CrateLint::UsePath { root_id: id, .. } |
4874 CrateLint::QPathTrait { qpath_id: id, .. } => Some(id),
4879 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }