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_impl_defid) => {
202 if let Some(impl_span) = maybe_impl_defid.map_or(None,
203 |def_id| resolver.definitions.opt_span(def_id)) {
204 err.span_label(reduce_impl_span_to_impl_keyword(cm, impl_span),
205 "`Self` type implicitly declared here, on the `impl`");
208 Def::TyParam(typaram_defid) => {
209 if let Some(typaram_span) = resolver.definitions.opt_span(typaram_defid) {
210 err.span_label(typaram_span, "type variable from outer function");
214 bug!("TypeParametersFromOuterFunction should only be used with Def::SelfTy or \
219 // Try to retrieve the span of the function signature and generate a new message with
220 // a local type parameter
221 let sugg_msg = "try using a local type parameter instead";
222 if let Some((sugg_span, new_snippet)) = cm.generate_local_type_param_snippet(span) {
223 // Suggest the modification to the user
224 err.span_suggestion_with_applicability(
228 Applicability::MachineApplicable,
230 } else if let Some(sp) = cm.generate_fn_name_span(span) {
231 err.span_label(sp, "try adding a local type parameter in this method instead");
233 err.help("try using a local type parameter instead");
238 ResolutionError::NameAlreadyUsedInTypeParameterList(name, first_use_span) => {
239 let mut err = struct_span_err!(resolver.session,
242 "the name `{}` is already used for a type parameter \
243 in this type parameter list",
245 err.span_label(span, "already used");
246 err.span_label(first_use_span.clone(), format!("first use of `{}`", name));
249 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
250 let mut err = struct_span_err!(resolver.session,
253 "method `{}` is not a member of trait `{}`",
256 err.span_label(span, format!("not a member of trait `{}`", trait_));
259 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
260 let mut err = struct_span_err!(resolver.session,
263 "type `{}` is not a member of trait `{}`",
266 err.span_label(span, format!("not a member of trait `{}`", trait_));
269 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
270 let mut err = struct_span_err!(resolver.session,
273 "const `{}` is not a member of trait `{}`",
276 err.span_label(span, format!("not a member of trait `{}`", trait_));
279 ResolutionError::VariableNotBoundInPattern(binding_error) => {
280 let target_sp = binding_error.target.iter().cloned().collect::<Vec<_>>();
281 let msp = MultiSpan::from_spans(target_sp.clone());
282 let msg = format!("variable `{}` is not bound in all patterns", binding_error.name);
283 let mut err = resolver.session.struct_span_err_with_code(
286 DiagnosticId::Error("E0408".into()),
288 for sp in target_sp {
289 err.span_label(sp, format!("pattern doesn't bind `{}`", binding_error.name));
291 let origin_sp = binding_error.origin.iter().cloned();
292 for sp in origin_sp {
293 err.span_label(sp, "variable not in all patterns");
297 ResolutionError::VariableBoundWithDifferentMode(variable_name,
298 first_binding_span) => {
299 let mut err = struct_span_err!(resolver.session,
302 "variable `{}` is bound in inconsistent \
303 ways within the same match arm",
305 err.span_label(span, "bound in different ways");
306 err.span_label(first_binding_span, "first binding");
309 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
310 let mut err = struct_span_err!(resolver.session,
313 "identifier `{}` is bound more than once in this parameter list",
315 err.span_label(span, "used as parameter more than once");
318 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
319 let mut err = struct_span_err!(resolver.session,
322 "identifier `{}` is bound more than once in the same pattern",
324 err.span_label(span, "used in a pattern more than once");
327 ResolutionError::UndeclaredLabel(name, lev_candidate) => {
328 let mut err = struct_span_err!(resolver.session,
331 "use of undeclared label `{}`",
333 if let Some(lev_candidate) = lev_candidate {
334 err.span_label(span, format!("did you mean `{}`?", lev_candidate));
336 err.span_label(span, format!("undeclared label `{}`", name));
340 ResolutionError::SelfImportsOnlyAllowedWithin => {
341 struct_span_err!(resolver.session,
345 "`self` imports are only allowed within a { } list")
347 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
348 let mut err = struct_span_err!(resolver.session, span, E0430,
349 "`self` import can only appear once in an import list");
350 err.span_label(span, "can only appear once in an import list");
353 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
354 let mut err = struct_span_err!(resolver.session, span, E0431,
355 "`self` import can only appear in an import list with \
356 a non-empty prefix");
357 err.span_label(span, "can only appear in an import list with a non-empty prefix");
360 ResolutionError::UnresolvedImport(name) => {
361 let (span, msg) = match name {
362 Some((sp, n, _)) => (sp, format!("unresolved import `{}`", n)),
363 None => (span, "unresolved import".to_owned()),
365 let mut err = struct_span_err!(resolver.session, span, E0432, "{}", msg);
366 if let Some((_, _, p)) = name {
367 err.span_label(span, p);
371 ResolutionError::FailedToResolve(msg) => {
372 let mut err = struct_span_err!(resolver.session, span, E0433,
373 "failed to resolve. {}", msg);
374 err.span_label(span, msg);
377 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
378 let mut err = struct_span_err!(resolver.session,
382 "can't capture dynamic environment in a fn item");
383 err.help("use the `|| { ... }` closure form instead");
386 ResolutionError::AttemptToUseNonConstantValueInConstant => {
387 let mut err = struct_span_err!(resolver.session, span, E0435,
388 "attempt to use a non-constant value in a constant");
389 err.span_label(span, "non-constant value");
392 ResolutionError::BindingShadowsSomethingUnacceptable(what_binding, name, binding) => {
393 let shadows_what = PathResolution::new(binding.def()).kind_name();
394 let mut err = struct_span_err!(resolver.session,
397 "{}s cannot shadow {}s", what_binding, shadows_what);
398 err.span_label(span, format!("cannot be named the same as a {}", shadows_what));
399 let participle = if binding.is_import() { "imported" } else { "defined" };
400 let msg = format!("a {} `{}` is {} here", shadows_what, name, participle);
401 err.span_label(binding.span, msg);
404 ResolutionError::ForwardDeclaredTyParam => {
405 let mut err = struct_span_err!(resolver.session, span, E0128,
406 "type parameters with a default cannot use \
407 forward declared identifiers");
409 span, "defaulted type parameters cannot be forward declared".to_string());
415 /// Adjust the impl span so that just the `impl` keyword is taken by removing
416 /// everything after `<` (`"impl<T> Iterator for A<T> {}" -> "impl"`) and
417 /// everything after the first whitespace (`"impl Iterator for A" -> "impl"`)
419 /// Attention: The method used is very fragile since it essentially duplicates the work of the
420 /// parser. If you need to use this function or something similar, please consider updating the
421 /// source_map functions and this function to something more robust.
422 fn reduce_impl_span_to_impl_keyword(cm: &SourceMap, impl_span: Span) -> Span {
423 let impl_span = cm.span_until_char(impl_span, '<');
424 let impl_span = cm.span_until_whitespace(impl_span);
428 #[derive(Copy, Clone, Debug)]
431 binding_mode: BindingMode,
434 /// Map from the name in a pattern to its binding mode.
435 type BindingMap = FxHashMap<Ident, BindingInfo>;
437 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
448 fn descr(self) -> &'static str {
450 PatternSource::Match => "match binding",
451 PatternSource::IfLet => "if let binding",
452 PatternSource::WhileLet => "while let binding",
453 PatternSource::Let => "let binding",
454 PatternSource::For => "for binding",
455 PatternSource::FnParam => "function parameter",
460 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
461 enum AliasPossibility {
466 #[derive(Copy, Clone, Debug)]
467 enum PathSource<'a> {
468 // Type paths `Path`.
470 // Trait paths in bounds or impls.
471 Trait(AliasPossibility),
472 // Expression paths `path`, with optional parent context.
473 Expr(Option<&'a Expr>),
474 // Paths in path patterns `Path`.
476 // Paths in struct expressions and patterns `Path { .. }`.
478 // Paths in tuple struct patterns `Path(..)`.
480 // `m::A::B` in `<T as m::A>::B::C`.
481 TraitItem(Namespace),
482 // Path in `pub(path)`
484 // Path in `use a::b::{...};`
488 impl<'a> PathSource<'a> {
489 fn namespace(self) -> Namespace {
491 PathSource::Type | PathSource::Trait(_) | PathSource::Struct |
492 PathSource::Visibility | PathSource::ImportPrefix => TypeNS,
493 PathSource::Expr(..) | PathSource::Pat | PathSource::TupleStruct => ValueNS,
494 PathSource::TraitItem(ns) => ns,
498 fn global_by_default(self) -> bool {
500 PathSource::Visibility | PathSource::ImportPrefix => true,
501 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
502 PathSource::Struct | PathSource::TupleStruct |
503 PathSource::Trait(_) | PathSource::TraitItem(..) => false,
507 fn defer_to_typeck(self) -> bool {
509 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
510 PathSource::Struct | PathSource::TupleStruct => true,
511 PathSource::Trait(_) | PathSource::TraitItem(..) |
512 PathSource::Visibility | PathSource::ImportPrefix => false,
516 fn descr_expected(self) -> &'static str {
518 PathSource::Type => "type",
519 PathSource::Trait(_) => "trait",
520 PathSource::Pat => "unit struct/variant or constant",
521 PathSource::Struct => "struct, variant or union type",
522 PathSource::TupleStruct => "tuple struct/variant",
523 PathSource::Visibility => "module",
524 PathSource::ImportPrefix => "module or enum",
525 PathSource::TraitItem(ns) => match ns {
526 TypeNS => "associated type",
527 ValueNS => "method or associated constant",
528 MacroNS => bug!("associated macro"),
530 PathSource::Expr(parent) => match parent.map(|p| &p.node) {
531 // "function" here means "anything callable" rather than `Def::Fn`,
532 // this is not precise but usually more helpful than just "value".
533 Some(&ExprKind::Call(..)) => "function",
539 fn is_expected(self, def: Def) -> bool {
541 PathSource::Type => match def {
542 Def::Struct(..) | Def::Union(..) | Def::Enum(..) |
543 Def::Trait(..) | Def::TyAlias(..) | Def::AssociatedTy(..) |
544 Def::PrimTy(..) | Def::TyParam(..) | Def::SelfTy(..) |
545 Def::Existential(..) |
546 Def::ForeignTy(..) => true,
549 PathSource::Trait(AliasPossibility::No) => match def {
550 Def::Trait(..) => true,
553 PathSource::Trait(AliasPossibility::Maybe) => match def {
554 Def::Trait(..) => true,
555 Def::TraitAlias(..) => true,
558 PathSource::Expr(..) => match def {
559 Def::StructCtor(_, CtorKind::Const) | Def::StructCtor(_, CtorKind::Fn) |
560 Def::VariantCtor(_, CtorKind::Const) | Def::VariantCtor(_, CtorKind::Fn) |
561 Def::Const(..) | Def::Static(..) | Def::Local(..) | Def::Upvar(..) |
562 Def::Fn(..) | Def::Method(..) | Def::AssociatedConst(..) => true,
565 PathSource::Pat => match def {
566 Def::StructCtor(_, CtorKind::Const) |
567 Def::VariantCtor(_, CtorKind::Const) |
568 Def::Const(..) | Def::AssociatedConst(..) => true,
571 PathSource::TupleStruct => match def {
572 Def::StructCtor(_, CtorKind::Fn) | Def::VariantCtor(_, CtorKind::Fn) => true,
575 PathSource::Struct => match def {
576 Def::Struct(..) | Def::Union(..) | Def::Variant(..) |
577 Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) => true,
580 PathSource::TraitItem(ns) => match def {
581 Def::AssociatedConst(..) | Def::Method(..) if ns == ValueNS => true,
582 Def::AssociatedTy(..) if ns == TypeNS => true,
585 PathSource::ImportPrefix => match def {
586 Def::Mod(..) | Def::Enum(..) => true,
589 PathSource::Visibility => match def {
590 Def::Mod(..) => true,
596 fn error_code(self, has_unexpected_resolution: bool) -> &'static str {
597 __diagnostic_used!(E0404);
598 __diagnostic_used!(E0405);
599 __diagnostic_used!(E0412);
600 __diagnostic_used!(E0422);
601 __diagnostic_used!(E0423);
602 __diagnostic_used!(E0425);
603 __diagnostic_used!(E0531);
604 __diagnostic_used!(E0532);
605 __diagnostic_used!(E0573);
606 __diagnostic_used!(E0574);
607 __diagnostic_used!(E0575);
608 __diagnostic_used!(E0576);
609 __diagnostic_used!(E0577);
610 __diagnostic_used!(E0578);
611 match (self, has_unexpected_resolution) {
612 (PathSource::Trait(_), true) => "E0404",
613 (PathSource::Trait(_), false) => "E0405",
614 (PathSource::Type, true) => "E0573",
615 (PathSource::Type, false) => "E0412",
616 (PathSource::Struct, true) => "E0574",
617 (PathSource::Struct, false) => "E0422",
618 (PathSource::Expr(..), true) => "E0423",
619 (PathSource::Expr(..), false) => "E0425",
620 (PathSource::Pat, true) | (PathSource::TupleStruct, true) => "E0532",
621 (PathSource::Pat, false) | (PathSource::TupleStruct, false) => "E0531",
622 (PathSource::TraitItem(..), true) => "E0575",
623 (PathSource::TraitItem(..), false) => "E0576",
624 (PathSource::Visibility, true) | (PathSource::ImportPrefix, true) => "E0577",
625 (PathSource::Visibility, false) | (PathSource::ImportPrefix, false) => "E0578",
630 struct UsePlacementFinder {
631 target_module: NodeId,
636 impl UsePlacementFinder {
637 fn check(krate: &Crate, target_module: NodeId) -> (Option<Span>, bool) {
638 let mut finder = UsePlacementFinder {
643 visit::walk_crate(&mut finder, krate);
644 (finder.span, finder.found_use)
648 impl<'tcx> Visitor<'tcx> for UsePlacementFinder {
651 module: &'tcx ast::Mod,
653 _: &[ast::Attribute],
656 if self.span.is_some() {
659 if node_id != self.target_module {
660 visit::walk_mod(self, module);
663 // find a use statement
664 for item in &module.items {
666 ItemKind::Use(..) => {
667 // don't suggest placing a use before the prelude
668 // import or other generated ones
669 if item.span.ctxt().outer().expn_info().is_none() {
670 self.span = Some(item.span.shrink_to_lo());
671 self.found_use = true;
675 // don't place use before extern crate
676 ItemKind::ExternCrate(_) => {}
677 // but place them before the first other item
678 _ => if self.span.map_or(true, |span| item.span < span ) {
679 if item.span.ctxt().outer().expn_info().is_none() {
680 // don't insert between attributes and an item
681 if item.attrs.is_empty() {
682 self.span = Some(item.span.shrink_to_lo());
684 // find the first attribute on the item
685 for attr in &item.attrs {
686 if self.span.map_or(true, |span| attr.span < span) {
687 self.span = Some(attr.span.shrink_to_lo());
698 /// This thing walks the whole crate in DFS manner, visiting each item, resolving names as it goes.
699 impl<'a, 'tcx, 'cl> Visitor<'tcx> for Resolver<'a, 'cl> {
700 fn visit_item(&mut self, item: &'tcx Item) {
701 self.resolve_item(item);
703 fn visit_arm(&mut self, arm: &'tcx Arm) {
704 self.resolve_arm(arm);
706 fn visit_block(&mut self, block: &'tcx Block) {
707 self.resolve_block(block);
709 fn visit_anon_const(&mut self, constant: &'tcx ast::AnonConst) {
710 self.with_constant_rib(|this| {
711 visit::walk_anon_const(this, constant);
714 fn visit_expr(&mut self, expr: &'tcx Expr) {
715 self.resolve_expr(expr, None);
717 fn visit_local(&mut self, local: &'tcx Local) {
718 self.resolve_local(local);
720 fn visit_ty(&mut self, ty: &'tcx Ty) {
722 TyKind::Path(ref qself, ref path) => {
723 self.smart_resolve_path(ty.id, qself.as_ref(), path, PathSource::Type);
725 TyKind::ImplicitSelf => {
726 let self_ty = keywords::SelfType.ident();
727 let def = self.resolve_ident_in_lexical_scope(self_ty, TypeNS, Some(ty.id), ty.span)
728 .map_or(Def::Err, |d| d.def());
729 self.record_def(ty.id, PathResolution::new(def));
733 visit::walk_ty(self, ty);
735 fn visit_poly_trait_ref(&mut self,
736 tref: &'tcx ast::PolyTraitRef,
737 m: &'tcx ast::TraitBoundModifier) {
738 self.smart_resolve_path(tref.trait_ref.ref_id, None,
739 &tref.trait_ref.path, PathSource::Trait(AliasPossibility::Maybe));
740 visit::walk_poly_trait_ref(self, tref, m);
742 fn visit_foreign_item(&mut self, foreign_item: &'tcx ForeignItem) {
743 let type_parameters = match foreign_item.node {
744 ForeignItemKind::Fn(_, ref generics) => {
745 HasTypeParameters(generics, ItemRibKind)
747 ForeignItemKind::Static(..) => NoTypeParameters,
748 ForeignItemKind::Ty => NoTypeParameters,
749 ForeignItemKind::Macro(..) => NoTypeParameters,
751 self.with_type_parameter_rib(type_parameters, |this| {
752 visit::walk_foreign_item(this, foreign_item);
755 fn visit_fn(&mut self,
756 function_kind: FnKind<'tcx>,
757 declaration: &'tcx FnDecl,
761 let (rib_kind, asyncness) = match function_kind {
762 FnKind::ItemFn(_, ref header, ..) =>
763 (ItemRibKind, header.asyncness),
764 FnKind::Method(_, ref sig, _, _) =>
765 (TraitOrImplItemRibKind, sig.header.asyncness),
766 FnKind::Closure(_) =>
767 // Async closures aren't resolved through `visit_fn`-- they're
768 // processed separately
769 (ClosureRibKind(node_id), IsAsync::NotAsync),
772 // Create a value rib for the function.
773 self.ribs[ValueNS].push(Rib::new(rib_kind));
775 // Create a label rib for the function.
776 self.label_ribs.push(Rib::new(rib_kind));
778 // Add each argument to the rib.
779 let mut bindings_list = FxHashMap();
780 for argument in &declaration.inputs {
781 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
783 self.visit_ty(&argument.ty);
785 debug!("(resolving function) recorded argument");
787 visit::walk_fn_ret_ty(self, &declaration.output);
789 // Resolve the function body, potentially inside the body of an async closure
790 if let IsAsync::Async { closure_id, .. } = asyncness {
791 let rib_kind = ClosureRibKind(closure_id);
792 self.ribs[ValueNS].push(Rib::new(rib_kind));
793 self.label_ribs.push(Rib::new(rib_kind));
796 match function_kind {
797 FnKind::ItemFn(.., body) |
798 FnKind::Method(.., body) => {
799 self.visit_block(body);
801 FnKind::Closure(body) => {
802 self.visit_expr(body);
806 // Leave the body of the async closure
807 if asyncness.is_async() {
808 self.label_ribs.pop();
809 self.ribs[ValueNS].pop();
812 debug!("(resolving function) leaving function");
814 self.label_ribs.pop();
815 self.ribs[ValueNS].pop();
817 fn visit_generics(&mut self, generics: &'tcx Generics) {
818 // For type parameter defaults, we have to ban access
819 // to following type parameters, as the Substs can only
820 // provide previous type parameters as they're built. We
821 // put all the parameters on the ban list and then remove
822 // them one by one as they are processed and become available.
823 let mut default_ban_rib = Rib::new(ForwardTyParamBanRibKind);
824 let mut found_default = false;
825 default_ban_rib.bindings.extend(generics.params.iter()
826 .filter_map(|param| match param.kind {
827 GenericParamKind::Lifetime { .. } => None,
828 GenericParamKind::Type { ref default, .. } => {
829 found_default |= default.is_some();
831 Some((Ident::with_empty_ctxt(param.ident.name), Def::Err))
838 for param in &generics.params {
840 GenericParamKind::Lifetime { .. } => self.visit_generic_param(param),
841 GenericParamKind::Type { ref default, .. } => {
842 for bound in ¶m.bounds {
843 self.visit_param_bound(bound);
846 if let Some(ref ty) = default {
847 self.ribs[TypeNS].push(default_ban_rib);
849 default_ban_rib = self.ribs[TypeNS].pop().unwrap();
852 // Allow all following defaults to refer to this type parameter.
853 default_ban_rib.bindings.remove(&Ident::with_empty_ctxt(param.ident.name));
857 for p in &generics.where_clause.predicates {
858 self.visit_where_predicate(p);
863 #[derive(Copy, Clone)]
864 enum TypeParameters<'a, 'b> {
866 HasTypeParameters(// Type parameters.
869 // The kind of the rib used for type parameters.
873 /// The rib kind controls the translation of local
874 /// definitions (`Def::Local`) to upvars (`Def::Upvar`).
875 #[derive(Copy, Clone, Debug)]
877 /// No translation needs to be applied.
880 /// We passed through a closure scope at the given node ID.
881 /// Translate upvars as appropriate.
882 ClosureRibKind(NodeId /* func id */),
884 /// We passed through an impl or trait and are now in one of its
885 /// methods or associated types. Allow references to ty params that impl or trait
886 /// binds. Disallow any other upvars (including other ty params that are
888 TraitOrImplItemRibKind,
890 /// We passed through an item scope. Disallow upvars.
893 /// We're in a constant item. Can't refer to dynamic stuff.
896 /// We passed through a module.
897 ModuleRibKind(Module<'a>),
899 /// We passed through a `macro_rules!` statement
900 MacroDefinition(DefId),
902 /// All bindings in this rib are type parameters that can't be used
903 /// from the default of a type parameter because they're not declared
904 /// before said type parameter. Also see the `visit_generics` override.
905 ForwardTyParamBanRibKind,
910 /// A rib represents a scope names can live in. Note that these appear in many places, not just
911 /// around braces. At any place where the list of accessible names (of the given namespace)
912 /// changes or a new restrictions on the name accessibility are introduced, a new rib is put onto a
913 /// stack. This may be, for example, a `let` statement (because it introduces variables), a macro,
916 /// Different [rib kinds](enum.RibKind) are transparent for different names.
918 /// The resolution keeps a separate stack of ribs as it traverses the AST for each namespace. When
919 /// resolving, the name is looked up from inside out.
922 bindings: FxHashMap<Ident, Def>,
927 fn new(kind: RibKind<'a>) -> Rib<'a> {
929 bindings: FxHashMap(),
935 /// An intermediate resolution result.
937 /// This refers to the thing referred by a name. The difference between `Def` and `Item` is that
938 /// items are visible in their whole block, while defs only from the place they are defined
940 enum LexicalScopeBinding<'a> {
941 Item(&'a NameBinding<'a>),
945 impl<'a> LexicalScopeBinding<'a> {
946 fn item(self) -> Option<&'a NameBinding<'a>> {
948 LexicalScopeBinding::Item(binding) => Some(binding),
953 fn def(self) -> Def {
955 LexicalScopeBinding::Item(binding) => binding.def(),
956 LexicalScopeBinding::Def(def) => def,
961 #[derive(Copy, Clone, Debug)]
962 pub enum ModuleOrUniformRoot<'a> {
966 /// The `{{root}}` (`CrateRoot` aka "global") / `extern` initial segment
967 /// in which external crates resolve, and also `crate` (only in `{{root}}`,
968 /// but *not* `extern`), in the Rust 2018 edition.
972 #[derive(Clone, Debug)]
973 enum PathResult<'a> {
974 Module(ModuleOrUniformRoot<'a>),
975 NonModule(PathResolution),
977 Failed(Span, String, bool /* is the error from the last segment? */),
981 /// An anonymous module, eg. just a block.
986 /// { // This is an anonymous module
987 /// f(); // This resolves to (2) as we are inside the block.
990 /// f(); // Resolves to (1)
994 /// Any module with a name.
998 /// * A normal module ‒ either `mod from_file;` or `mod from_block { }`.
999 /// * A trait or an enum (it implicitly contains associated types, methods and variant
1004 /// One node in the tree of modules.
1005 pub struct ModuleData<'a> {
1006 parent: Option<Module<'a>>,
1009 // The def id of the closest normal module (`mod`) ancestor (including this module).
1010 normal_ancestor_id: DefId,
1012 resolutions: RefCell<FxHashMap<(Ident, Namespace), &'a RefCell<NameResolution<'a>>>>,
1013 legacy_macro_resolutions: RefCell<Vec<(Mark, Ident, MacroKind, Option<Def>)>>,
1014 macro_resolutions: RefCell<Vec<(Box<[Ident]>, Span)>>,
1016 // Macro invocations that can expand into items in this module.
1017 unresolved_invocations: RefCell<FxHashSet<Mark>>,
1019 no_implicit_prelude: bool,
1021 glob_importers: RefCell<Vec<&'a ImportDirective<'a>>>,
1022 globs: RefCell<Vec<&'a ImportDirective<'a>>>,
1024 // Used to memoize the traits in this module for faster searches through all traits in scope.
1025 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
1027 // Whether this module is populated. If not populated, any attempt to
1028 // access the children must be preceded with a
1029 // `populate_module_if_necessary` call.
1030 populated: Cell<bool>,
1032 /// Span of the module itself. Used for error reporting.
1038 type Module<'a> = &'a ModuleData<'a>;
1040 impl<'a> ModuleData<'a> {
1041 fn new(parent: Option<Module<'a>>,
1043 normal_ancestor_id: DefId,
1045 span: Span) -> Self {
1050 resolutions: RefCell::new(FxHashMap()),
1051 legacy_macro_resolutions: RefCell::new(Vec::new()),
1052 macro_resolutions: RefCell::new(Vec::new()),
1053 unresolved_invocations: RefCell::new(FxHashSet()),
1054 no_implicit_prelude: false,
1055 glob_importers: RefCell::new(Vec::new()),
1056 globs: RefCell::new(Vec::new()),
1057 traits: RefCell::new(None),
1058 populated: Cell::new(normal_ancestor_id.is_local()),
1064 fn for_each_child<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
1065 for (&(ident, ns), name_resolution) in self.resolutions.borrow().iter() {
1066 name_resolution.borrow().binding.map(|binding| f(ident, ns, binding));
1070 fn for_each_child_stable<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
1071 let resolutions = self.resolutions.borrow();
1072 let mut resolutions = resolutions.iter().collect::<Vec<_>>();
1073 resolutions.sort_by_cached_key(|&(&(ident, ns), _)| (ident.as_str(), ns));
1074 for &(&(ident, ns), &resolution) in resolutions.iter() {
1075 resolution.borrow().binding.map(|binding| f(ident, ns, binding));
1079 fn def(&self) -> Option<Def> {
1081 ModuleKind::Def(def, _) => Some(def),
1086 fn def_id(&self) -> Option<DefId> {
1087 self.def().as_ref().map(Def::def_id)
1090 // `self` resolves to the first module ancestor that `is_normal`.
1091 fn is_normal(&self) -> bool {
1093 ModuleKind::Def(Def::Mod(_), _) => true,
1098 fn is_trait(&self) -> bool {
1100 ModuleKind::Def(Def::Trait(_), _) => true,
1105 fn is_local(&self) -> bool {
1106 self.normal_ancestor_id.is_local()
1109 fn nearest_item_scope(&'a self) -> Module<'a> {
1110 if self.is_trait() { self.parent.unwrap() } else { self }
1114 impl<'a> fmt::Debug for ModuleData<'a> {
1115 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1116 write!(f, "{:?}", self.def())
1120 /// Records a possibly-private value, type, or module definition.
1121 #[derive(Clone, Debug)]
1122 pub struct NameBinding<'a> {
1123 kind: NameBindingKind<'a>,
1126 vis: ty::Visibility,
1129 pub trait ToNameBinding<'a> {
1130 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
1133 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
1134 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
1139 #[derive(Clone, Debug)]
1140 enum NameBindingKind<'a> {
1141 Def(Def, /* is_macro_export */ bool),
1144 binding: &'a NameBinding<'a>,
1145 directive: &'a ImportDirective<'a>,
1149 b1: &'a NameBinding<'a>,
1150 b2: &'a NameBinding<'a>,
1154 struct PrivacyError<'a>(Span, Name, &'a NameBinding<'a>);
1156 struct UseError<'a> {
1157 err: DiagnosticBuilder<'a>,
1158 /// Attach `use` statements for these candidates
1159 candidates: Vec<ImportSuggestion>,
1160 /// The node id of the module to place the use statements in
1162 /// Whether the diagnostic should state that it's "better"
1166 struct AmbiguityError<'a> {
1170 b1: &'a NameBinding<'a>,
1171 b2: &'a NameBinding<'a>,
1174 impl<'a> NameBinding<'a> {
1175 fn module(&self) -> Option<Module<'a>> {
1177 NameBindingKind::Module(module) => Some(module),
1178 NameBindingKind::Import { binding, .. } => binding.module(),
1183 fn def(&self) -> Def {
1185 NameBindingKind::Def(def, _) => def,
1186 NameBindingKind::Module(module) => module.def().unwrap(),
1187 NameBindingKind::Import { binding, .. } => binding.def(),
1188 NameBindingKind::Ambiguity { .. } => Def::Err,
1192 fn def_ignoring_ambiguity(&self) -> Def {
1194 NameBindingKind::Import { binding, .. } => binding.def_ignoring_ambiguity(),
1195 NameBindingKind::Ambiguity { b1, .. } => b1.def_ignoring_ambiguity(),
1200 fn get_macro<'b: 'a>(&self, resolver: &mut Resolver<'a, 'b>) -> Lrc<SyntaxExtension> {
1201 resolver.get_macro(self.def_ignoring_ambiguity())
1204 // We sometimes need to treat variants as `pub` for backwards compatibility
1205 fn pseudo_vis(&self) -> ty::Visibility {
1206 if self.is_variant() && self.def().def_id().is_local() {
1207 ty::Visibility::Public
1213 fn is_variant(&self) -> bool {
1215 NameBindingKind::Def(Def::Variant(..), _) |
1216 NameBindingKind::Def(Def::VariantCtor(..), _) => true,
1221 fn is_extern_crate(&self) -> bool {
1223 NameBindingKind::Import {
1224 directive: &ImportDirective {
1225 subclass: ImportDirectiveSubclass::ExternCrate(_), ..
1232 fn is_import(&self) -> bool {
1234 NameBindingKind::Import { .. } => true,
1239 fn is_renamed_extern_crate(&self) -> bool {
1240 if let NameBindingKind::Import { directive, ..} = self.kind {
1241 if let ImportDirectiveSubclass::ExternCrate(Some(_)) = directive.subclass {
1248 fn is_glob_import(&self) -> bool {
1250 NameBindingKind::Import { directive, .. } => directive.is_glob(),
1251 NameBindingKind::Ambiguity { b1, .. } => b1.is_glob_import(),
1256 fn is_importable(&self) -> bool {
1258 Def::AssociatedConst(..) | Def::Method(..) | Def::AssociatedTy(..) => false,
1263 fn is_macro_def(&self) -> bool {
1265 NameBindingKind::Def(Def::Macro(..), _) => true,
1270 fn descr(&self) -> &'static str {
1271 if self.is_extern_crate() { "extern crate" } else { self.def().kind_name() }
1275 /// Interns the names of the primitive types.
1277 /// All other types are defined somewhere and possibly imported, but the primitive ones need
1278 /// special handling, since they have no place of origin.
1279 struct PrimitiveTypeTable {
1280 primitive_types: FxHashMap<Name, PrimTy>,
1283 impl PrimitiveTypeTable {
1284 fn new() -> PrimitiveTypeTable {
1285 let mut table = PrimitiveTypeTable { primitive_types: FxHashMap() };
1287 table.intern("bool", Bool);
1288 table.intern("char", Char);
1289 table.intern("f32", Float(FloatTy::F32));
1290 table.intern("f64", Float(FloatTy::F64));
1291 table.intern("isize", Int(IntTy::Isize));
1292 table.intern("i8", Int(IntTy::I8));
1293 table.intern("i16", Int(IntTy::I16));
1294 table.intern("i32", Int(IntTy::I32));
1295 table.intern("i64", Int(IntTy::I64));
1296 table.intern("i128", Int(IntTy::I128));
1297 table.intern("str", Str);
1298 table.intern("usize", Uint(UintTy::Usize));
1299 table.intern("u8", Uint(UintTy::U8));
1300 table.intern("u16", Uint(UintTy::U16));
1301 table.intern("u32", Uint(UintTy::U32));
1302 table.intern("u64", Uint(UintTy::U64));
1303 table.intern("u128", Uint(UintTy::U128));
1307 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1308 self.primitive_types.insert(Symbol::intern(string), primitive_type);
1312 /// The main resolver class.
1314 /// This is the visitor that walks the whole crate.
1315 pub struct Resolver<'a, 'b: 'a> {
1316 session: &'a Session,
1319 pub definitions: Definitions,
1321 graph_root: Module<'a>,
1323 prelude: Option<Module<'a>>,
1324 extern_prelude: FxHashSet<Name>,
1326 /// n.b. This is used only for better diagnostics, not name resolution itself.
1327 has_self: FxHashSet<DefId>,
1329 /// Names of fields of an item `DefId` accessible with dot syntax.
1330 /// Used for hints during error reporting.
1331 field_names: FxHashMap<DefId, Vec<Name>>,
1333 /// All imports known to succeed or fail.
1334 determined_imports: Vec<&'a ImportDirective<'a>>,
1336 /// All non-determined imports.
1337 indeterminate_imports: Vec<&'a ImportDirective<'a>>,
1339 /// The module that represents the current item scope.
1340 current_module: Module<'a>,
1342 /// The current set of local scopes for types and values.
1343 /// FIXME #4948: Reuse ribs to avoid allocation.
1344 ribs: PerNS<Vec<Rib<'a>>>,
1346 /// The current set of local scopes, for labels.
1347 label_ribs: Vec<Rib<'a>>,
1349 /// The trait that the current context can refer to.
1350 current_trait_ref: Option<(Module<'a>, TraitRef)>,
1352 /// The current self type if inside an impl (used for better errors).
1353 current_self_type: Option<Ty>,
1355 /// The idents for the primitive types.
1356 primitive_type_table: PrimitiveTypeTable,
1359 import_map: ImportMap,
1360 pub freevars: FreevarMap,
1361 freevars_seen: NodeMap<NodeMap<usize>>,
1362 pub export_map: ExportMap,
1363 pub trait_map: TraitMap,
1365 /// A map from nodes to anonymous modules.
1366 /// Anonymous modules are pseudo-modules that are implicitly created around items
1367 /// contained within blocks.
1369 /// For example, if we have this:
1377 /// There will be an anonymous module created around `g` with the ID of the
1378 /// entry block for `f`.
1379 block_map: NodeMap<Module<'a>>,
1380 module_map: FxHashMap<DefId, Module<'a>>,
1381 extern_module_map: FxHashMap<(DefId, bool /* MacrosOnly? */), Module<'a>>,
1383 pub make_glob_map: bool,
1384 /// Maps imports to the names of items actually imported (this actually maps
1385 /// all imports, but only glob imports are actually interesting).
1386 pub glob_map: GlobMap,
1388 used_imports: FxHashSet<(NodeId, Namespace)>,
1389 pub maybe_unused_trait_imports: NodeSet,
1390 pub maybe_unused_extern_crates: Vec<(NodeId, Span)>,
1392 /// A list of labels as of yet unused. Labels will be removed from this map when
1393 /// they are used (in a `break` or `continue` statement)
1394 pub unused_labels: FxHashMap<NodeId, Span>,
1396 /// privacy errors are delayed until the end in order to deduplicate them
1397 privacy_errors: Vec<PrivacyError<'a>>,
1398 /// ambiguity errors are delayed for deduplication
1399 ambiguity_errors: Vec<AmbiguityError<'a>>,
1400 /// `use` injections are delayed for better placement and deduplication
1401 use_injections: Vec<UseError<'a>>,
1402 /// `use` injections for proc macros wrongly imported with #[macro_use]
1403 proc_mac_errors: Vec<macros::ProcMacError>,
1404 /// crate-local macro expanded `macro_export` referred to by a module-relative path
1405 macro_expanded_macro_export_errors: BTreeSet<(Span, Span)>,
1406 /// macro-expanded `macro_rules` shadowing existing macros
1407 disallowed_shadowing: Vec<&'a LegacyBinding<'a>>,
1409 arenas: &'a ResolverArenas<'a>,
1410 dummy_binding: &'a NameBinding<'a>,
1412 crate_loader: &'a mut CrateLoader<'b>,
1413 macro_names: FxHashSet<Ident>,
1414 macro_prelude: FxHashMap<Name, &'a NameBinding<'a>>,
1415 unshadowable_attrs: FxHashMap<Name, &'a NameBinding<'a>>,
1416 pub all_macros: FxHashMap<Name, Def>,
1417 macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>,
1418 macro_defs: FxHashMap<Mark, DefId>,
1419 local_macro_def_scopes: FxHashMap<NodeId, Module<'a>>,
1420 pub whitelisted_legacy_custom_derives: Vec<Name>,
1421 pub found_unresolved_macro: bool,
1423 /// List of crate local macros that we need to warn about as being unused.
1424 /// Right now this only includes macro_rules! macros, and macros 2.0.
1425 unused_macros: FxHashSet<DefId>,
1427 /// Maps the `Mark` of an expansion to its containing module or block.
1428 invocations: FxHashMap<Mark, &'a InvocationData<'a>>,
1430 /// Avoid duplicated errors for "name already defined".
1431 name_already_seen: FxHashMap<Name, Span>,
1433 /// A set of procedural macros imported by `#[macro_use]` that have already been warned about
1434 warned_proc_macros: FxHashSet<Name>,
1436 potentially_unused_imports: Vec<&'a ImportDirective<'a>>,
1438 /// This table maps struct IDs into struct constructor IDs,
1439 /// it's not used during normal resolution, only for better error reporting.
1440 struct_constructors: DefIdMap<(Def, ty::Visibility)>,
1442 /// Only used for better errors on `fn(): fn()`
1443 current_type_ascription: Vec<Span>,
1445 injected_crate: Option<Module<'a>>,
1447 /// Only supposed to be used by rustdoc, otherwise should be false.
1448 pub ignore_extern_prelude_feature: bool,
1451 /// Nothing really interesting here, it just provides memory for the rest of the crate.
1452 pub struct ResolverArenas<'a> {
1453 modules: arena::TypedArena<ModuleData<'a>>,
1454 local_modules: RefCell<Vec<Module<'a>>>,
1455 name_bindings: arena::TypedArena<NameBinding<'a>>,
1456 import_directives: arena::TypedArena<ImportDirective<'a>>,
1457 name_resolutions: arena::TypedArena<RefCell<NameResolution<'a>>>,
1458 invocation_data: arena::TypedArena<InvocationData<'a>>,
1459 legacy_bindings: arena::TypedArena<LegacyBinding<'a>>,
1462 impl<'a> ResolverArenas<'a> {
1463 fn alloc_module(&'a self, module: ModuleData<'a>) -> Module<'a> {
1464 let module = self.modules.alloc(module);
1465 if module.def_id().map(|def_id| def_id.is_local()).unwrap_or(true) {
1466 self.local_modules.borrow_mut().push(module);
1470 fn local_modules(&'a self) -> ::std::cell::Ref<'a, Vec<Module<'a>>> {
1471 self.local_modules.borrow()
1473 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1474 self.name_bindings.alloc(name_binding)
1476 fn alloc_import_directive(&'a self, import_directive: ImportDirective<'a>)
1477 -> &'a ImportDirective {
1478 self.import_directives.alloc(import_directive)
1480 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1481 self.name_resolutions.alloc(Default::default())
1483 fn alloc_invocation_data(&'a self, expansion_data: InvocationData<'a>)
1484 -> &'a InvocationData<'a> {
1485 self.invocation_data.alloc(expansion_data)
1487 fn alloc_legacy_binding(&'a self, binding: LegacyBinding<'a>) -> &'a LegacyBinding<'a> {
1488 self.legacy_bindings.alloc(binding)
1492 impl<'a, 'b: 'a, 'cl: 'b> ty::DefIdTree for &'a Resolver<'b, 'cl> {
1493 fn parent(self, id: DefId) -> Option<DefId> {
1495 LOCAL_CRATE => self.definitions.def_key(id.index).parent,
1496 _ => self.cstore.def_key(id).parent,
1497 }.map(|index| DefId { index, ..id })
1501 /// This interface is used through the AST→HIR step, to embed full paths into the HIR. After that
1502 /// the resolver is no longer needed as all the relevant information is inline.
1503 impl<'a, 'cl> hir::lowering::Resolver for Resolver<'a, 'cl> {
1504 fn resolve_hir_path(&mut self, path: &mut hir::Path, is_value: bool) {
1505 self.resolve_hir_path_cb(path, is_value,
1506 |resolver, span, error| resolve_error(resolver, span, error))
1509 fn resolve_str_path(
1512 crate_root: Option<&str>,
1513 components: &[&str],
1514 args: Option<P<hir::GenericArgs>>,
1517 let mut segments = iter::once(keywords::CrateRoot.ident())
1519 crate_root.into_iter()
1520 .chain(components.iter().cloned())
1521 .map(Ident::from_str)
1522 ).map(hir::PathSegment::from_ident).collect::<Vec<_>>();
1524 if let Some(args) = args {
1525 let ident = segments.last().unwrap().ident;
1526 *segments.last_mut().unwrap() = hir::PathSegment {
1533 let mut path = hir::Path {
1536 segments: segments.into(),
1539 self.resolve_hir_path(&mut path, is_value);
1543 fn get_resolution(&mut self, id: NodeId) -> Option<PathResolution> {
1544 self.def_map.get(&id).cloned()
1547 fn get_import(&mut self, id: NodeId) -> PerNS<Option<PathResolution>> {
1548 self.import_map.get(&id).cloned().unwrap_or_default()
1551 fn definitions(&mut self) -> &mut Definitions {
1552 &mut self.definitions
1556 impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
1557 /// Rustdoc uses this to resolve things in a recoverable way. ResolutionError<'a>
1558 /// isn't something that can be returned because it can't be made to live that long,
1559 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
1560 /// just that an error occurred.
1561 pub fn resolve_str_path_error(&mut self, span: Span, path_str: &str, is_value: bool)
1562 -> Result<hir::Path, ()> {
1564 let mut errored = false;
1566 let mut path = if path_str.starts_with("::") {
1570 segments: iter::once(keywords::CrateRoot.ident()).chain({
1571 path_str.split("::").skip(1).map(Ident::from_str)
1572 }).map(hir::PathSegment::from_ident).collect(),
1578 segments: path_str.split("::").map(Ident::from_str)
1579 .map(hir::PathSegment::from_ident).collect(),
1582 self.resolve_hir_path_cb(&mut path, is_value, |_, _, _| errored = true);
1583 if errored || path.def == Def::Err {
1590 /// resolve_hir_path, but takes a callback in case there was an error
1591 fn resolve_hir_path_cb<F>(&mut self, path: &mut hir::Path, is_value: bool, error_callback: F)
1592 where F: for<'c, 'b> FnOnce(&'c mut Resolver, Span, ResolutionError<'b>)
1594 let namespace = if is_value { ValueNS } else { TypeNS };
1595 let hir::Path { ref segments, span, ref mut def } = *path;
1596 let path: Vec<_> = segments.iter().map(|seg| seg.ident).collect();
1597 // FIXME (Manishearth): Intra doc links won't get warned of epoch changes
1598 match self.resolve_path(None, &path, Some(namespace), true, span, CrateLint::No) {
1599 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
1600 *def = module.def().unwrap(),
1601 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 =>
1602 *def = path_res.base_def(),
1603 PathResult::NonModule(..) => match self.resolve_path(
1611 PathResult::Failed(span, msg, _) => {
1612 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1616 PathResult::Module(ModuleOrUniformRoot::UniformRoot(_)) |
1617 PathResult::Indeterminate => unreachable!(),
1618 PathResult::Failed(span, msg, _) => {
1619 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1625 impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
1626 pub fn new(session: &'a Session,
1630 make_glob_map: MakeGlobMap,
1631 crate_loader: &'a mut CrateLoader<'crateloader>,
1632 arenas: &'a ResolverArenas<'a>)
1633 -> Resolver<'a, 'crateloader> {
1634 let root_def_id = DefId::local(CRATE_DEF_INDEX);
1635 let root_module_kind = ModuleKind::Def(Def::Mod(root_def_id), keywords::Invalid.name());
1636 let graph_root = arenas.alloc_module(ModuleData {
1637 no_implicit_prelude: attr::contains_name(&krate.attrs, "no_implicit_prelude"),
1638 ..ModuleData::new(None, root_module_kind, root_def_id, Mark::root(), krate.span)
1640 let mut module_map = FxHashMap();
1641 module_map.insert(DefId::local(CRATE_DEF_INDEX), graph_root);
1643 let mut definitions = Definitions::new();
1644 DefCollector::new(&mut definitions, Mark::root())
1645 .collect_root(crate_name, session.local_crate_disambiguator());
1647 let mut extern_prelude: FxHashSet<Name> =
1648 session.opts.externs.iter().map(|kv| Symbol::intern(kv.0)).collect();
1649 if !attr::contains_name(&krate.attrs, "no_core") {
1650 if !attr::contains_name(&krate.attrs, "no_std") {
1651 extern_prelude.insert(Symbol::intern("std"));
1653 extern_prelude.insert(Symbol::intern("core"));
1657 let mut invocations = FxHashMap();
1658 invocations.insert(Mark::root(),
1659 arenas.alloc_invocation_data(InvocationData::root(graph_root)));
1661 let mut macro_defs = FxHashMap();
1662 macro_defs.insert(Mark::root(), root_def_id);
1671 // The outermost module has def ID 0; this is not reflected in the
1677 has_self: FxHashSet(),
1678 field_names: FxHashMap(),
1680 determined_imports: Vec::new(),
1681 indeterminate_imports: Vec::new(),
1683 current_module: graph_root,
1685 value_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1686 type_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1687 macro_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1689 label_ribs: Vec::new(),
1691 current_trait_ref: None,
1692 current_self_type: None,
1694 primitive_type_table: PrimitiveTypeTable::new(),
1697 import_map: NodeMap(),
1698 freevars: NodeMap(),
1699 freevars_seen: NodeMap(),
1700 export_map: FxHashMap(),
1701 trait_map: NodeMap(),
1703 block_map: NodeMap(),
1704 extern_module_map: FxHashMap(),
1706 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1707 glob_map: NodeMap(),
1709 used_imports: FxHashSet(),
1710 maybe_unused_trait_imports: NodeSet(),
1711 maybe_unused_extern_crates: Vec::new(),
1713 unused_labels: FxHashMap(),
1715 privacy_errors: Vec::new(),
1716 ambiguity_errors: Vec::new(),
1717 use_injections: Vec::new(),
1718 proc_mac_errors: Vec::new(),
1719 disallowed_shadowing: Vec::new(),
1720 macro_expanded_macro_export_errors: BTreeSet::new(),
1723 dummy_binding: arenas.alloc_name_binding(NameBinding {
1724 kind: NameBindingKind::Def(Def::Err, false),
1725 expansion: Mark::root(),
1727 vis: ty::Visibility::Public,
1731 macro_names: FxHashSet(),
1732 macro_prelude: FxHashMap(),
1733 unshadowable_attrs: FxHashMap(),
1734 all_macros: FxHashMap(),
1735 macro_map: FxHashMap(),
1738 local_macro_def_scopes: FxHashMap(),
1739 name_already_seen: FxHashMap(),
1740 whitelisted_legacy_custom_derives: Vec::new(),
1741 warned_proc_macros: FxHashSet(),
1742 potentially_unused_imports: Vec::new(),
1743 struct_constructors: DefIdMap(),
1744 found_unresolved_macro: false,
1745 unused_macros: FxHashSet(),
1746 current_type_ascription: Vec::new(),
1747 injected_crate: None,
1748 ignore_extern_prelude_feature: false,
1752 pub fn arenas() -> ResolverArenas<'a> {
1754 modules: arena::TypedArena::new(),
1755 local_modules: RefCell::new(Vec::new()),
1756 name_bindings: arena::TypedArena::new(),
1757 import_directives: arena::TypedArena::new(),
1758 name_resolutions: arena::TypedArena::new(),
1759 invocation_data: arena::TypedArena::new(),
1760 legacy_bindings: arena::TypedArena::new(),
1764 /// Runs the function on each namespace.
1765 fn per_ns<F: FnMut(&mut Self, Namespace)>(&mut self, mut f: F) {
1771 fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
1773 match self.macro_defs.get(&ctxt.outer()) {
1774 Some(&def_id) => return def_id,
1775 None => ctxt.remove_mark(),
1780 /// Entry point to crate resolution.
1781 pub fn resolve_crate(&mut self, krate: &Crate) {
1782 ImportResolver { resolver: self }.finalize_imports();
1783 self.current_module = self.graph_root;
1784 self.finalize_current_module_macro_resolutions();
1786 visit::walk_crate(self, krate);
1788 check_unused::check_crate(self, krate);
1789 self.report_errors(krate);
1790 self.crate_loader.postprocess(krate);
1797 normal_ancestor_id: DefId,
1801 let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expansion, span);
1802 self.arenas.alloc_module(module)
1805 fn record_use(&mut self, ident: Ident, ns: Namespace, binding: &'a NameBinding<'a>, span: Span)
1806 -> bool /* true if an error was reported */ {
1807 match binding.kind {
1808 NameBindingKind::Import { directive, binding, ref used }
1811 directive.used.set(true);
1812 self.used_imports.insert((directive.id, ns));
1813 self.add_to_glob_map(directive.id, ident);
1814 self.record_use(ident, ns, binding, span)
1816 NameBindingKind::Import { .. } => false,
1817 NameBindingKind::Ambiguity { b1, b2 } => {
1818 self.ambiguity_errors.push(AmbiguityError {
1819 span, name: ident.name, lexical: false, b1, b2,
1827 fn add_to_glob_map(&mut self, id: NodeId, ident: Ident) {
1828 if self.make_glob_map {
1829 self.glob_map.entry(id).or_default().insert(ident.name);
1833 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1834 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1835 /// `ident` in the first scope that defines it (or None if no scopes define it).
1837 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1838 /// the items are defined in the block. For example,
1841 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1844 /// g(); // This resolves to the local variable `g` since it shadows the item.
1848 /// Invariant: This must only be called during main resolution, not during
1849 /// import resolution.
1850 fn resolve_ident_in_lexical_scope(&mut self,
1853 record_used_id: Option<NodeId>,
1855 -> Option<LexicalScopeBinding<'a>> {
1856 let record_used = record_used_id.is_some();
1857 assert!(ns == TypeNS || ns == ValueNS);
1859 ident.span = if ident.name == keywords::SelfType.name() {
1860 // FIXME(jseyfried) improve `Self` hygiene
1861 ident.span.with_ctxt(SyntaxContext::empty())
1866 ident = ident.modern_and_legacy();
1869 // Walk backwards up the ribs in scope.
1870 let mut module = self.graph_root;
1871 for i in (0 .. self.ribs[ns].len()).rev() {
1872 if let Some(def) = self.ribs[ns][i].bindings.get(&ident).cloned() {
1873 // The ident resolves to a type parameter or local variable.
1874 return Some(LexicalScopeBinding::Def(
1875 self.adjust_local_def(ns, i, def, record_used, path_span)
1879 module = match self.ribs[ns][i].kind {
1880 ModuleRibKind(module) => module,
1881 MacroDefinition(def) if def == self.macro_def(ident.span.ctxt()) => {
1882 // If an invocation of this macro created `ident`, give up on `ident`
1883 // and switch to `ident`'s source from the macro definition.
1884 ident.span.remove_mark();
1890 let item = self.resolve_ident_in_module_unadjusted(
1891 ModuleOrUniformRoot::Module(module),
1898 if let Ok(binding) = item {
1899 // The ident resolves to an item.
1900 return Some(LexicalScopeBinding::Item(binding));
1904 ModuleKind::Block(..) => {}, // We can see through blocks
1909 ident.span = ident.span.modern();
1910 let mut poisoned = None;
1912 let opt_module = if let Some(node_id) = record_used_id {
1913 self.hygienic_lexical_parent_with_compatibility_fallback(module, &mut ident.span,
1914 node_id, &mut poisoned)
1916 self.hygienic_lexical_parent(module, &mut ident.span)
1918 module = unwrap_or!(opt_module, break);
1919 let orig_current_module = self.current_module;
1920 self.current_module = module; // Lexical resolutions can never be a privacy error.
1921 let result = self.resolve_ident_in_module_unadjusted(
1922 ModuleOrUniformRoot::Module(module),
1929 self.current_module = orig_current_module;
1933 if let Some(node_id) = poisoned {
1934 self.session.buffer_lint_with_diagnostic(
1935 lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
1936 node_id, ident.span,
1937 &format!("cannot find {} `{}` in this scope", ns.descr(), ident),
1938 lint::builtin::BuiltinLintDiagnostics::
1939 ProcMacroDeriveResolutionFallback(ident.span),
1942 return Some(LexicalScopeBinding::Item(binding))
1944 Err(Determined) => continue,
1945 Err(Undetermined) =>
1946 span_bug!(ident.span, "undetermined resolution during main resolution pass"),
1950 if !module.no_implicit_prelude {
1951 // `record_used` means that we don't try to load crates during speculative resolution
1952 if record_used && ns == TypeNS && self.extern_prelude.contains(&ident.name) {
1953 if !self.session.features_untracked().extern_prelude &&
1954 !self.ignore_extern_prelude_feature {
1955 feature_err(&self.session.parse_sess, "extern_prelude",
1956 ident.span, GateIssue::Language,
1957 "access to extern crates through prelude is experimental").emit();
1960 let crate_root = self.load_extern_prelude_crate_if_needed(ident);
1962 let binding = (crate_root, ty::Visibility::Public,
1963 ident.span, Mark::root()).to_name_binding(self.arenas);
1964 return Some(LexicalScopeBinding::Item(binding));
1966 if ns == TypeNS && is_known_tool(ident.name) {
1967 let binding = (Def::ToolMod, ty::Visibility::Public,
1968 ident.span, Mark::root()).to_name_binding(self.arenas);
1969 return Some(LexicalScopeBinding::Item(binding));
1971 if let Some(prelude) = self.prelude {
1972 if let Ok(binding) = self.resolve_ident_in_module_unadjusted(
1973 ModuleOrUniformRoot::Module(prelude),
1980 return Some(LexicalScopeBinding::Item(binding));
1988 fn load_extern_prelude_crate_if_needed(&mut self, ident: Ident) -> Module<'a> {
1989 let crate_id = self.crate_loader.process_path_extern(ident.name, ident.span);
1990 let crate_root = self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
1991 self.populate_module_if_necessary(&crate_root);
1995 fn hygienic_lexical_parent(&mut self, module: Module<'a>, span: &mut Span)
1996 -> Option<Module<'a>> {
1997 if !module.expansion.is_descendant_of(span.ctxt().outer()) {
1998 return Some(self.macro_def_scope(span.remove_mark()));
2001 if let ModuleKind::Block(..) = module.kind {
2002 return Some(module.parent.unwrap());
2008 fn hygienic_lexical_parent_with_compatibility_fallback(&mut self, module: Module<'a>,
2009 span: &mut Span, node_id: NodeId,
2010 poisoned: &mut Option<NodeId>)
2011 -> Option<Module<'a>> {
2012 if let module @ Some(..) = self.hygienic_lexical_parent(module, span) {
2016 // We need to support the next case under a deprecation warning
2019 // ---- begin: this comes from a proc macro derive
2020 // mod implementation_details {
2021 // // Note that `MyStruct` is not in scope here.
2022 // impl SomeTrait for MyStruct { ... }
2026 // So we have to fall back to the module's parent during lexical resolution in this case.
2027 if let Some(parent) = module.parent {
2028 // Inner module is inside the macro, parent module is outside of the macro.
2029 if module.expansion != parent.expansion &&
2030 module.expansion.is_descendant_of(parent.expansion) {
2031 // The macro is a proc macro derive
2032 if module.expansion.looks_like_proc_macro_derive() {
2033 if parent.expansion.is_descendant_of(span.ctxt().outer()) {
2034 *poisoned = Some(node_id);
2035 return module.parent;
2044 fn resolve_ident_in_module(&mut self,
2045 module: ModuleOrUniformRoot<'a>,
2050 -> Result<&'a NameBinding<'a>, Determinacy> {
2051 ident.span = ident.span.modern();
2052 let orig_current_module = self.current_module;
2053 if let ModuleOrUniformRoot::Module(module) = module {
2054 if let Some(def) = ident.span.adjust(module.expansion) {
2055 self.current_module = self.macro_def_scope(def);
2058 let result = self.resolve_ident_in_module_unadjusted(
2059 module, ident, ns, false, record_used, span,
2061 self.current_module = orig_current_module;
2065 fn resolve_crate_root(&mut self, ident: Ident) -> Module<'a> {
2066 let mut ctxt = ident.span.ctxt();
2067 let mark = if ident.name == keywords::DollarCrate.name() {
2068 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
2069 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
2070 // as described in `SyntaxContext::apply_mark`, so we ignore prepended modern marks.
2071 // FIXME: This is only a guess and it doesn't work correctly for `macro_rules!`
2072 // definitions actually produced by `macro` and `macro` definitions produced by
2073 // `macro_rules!`, but at least such configurations are not stable yet.
2074 ctxt = ctxt.modern_and_legacy();
2075 let mut iter = ctxt.marks().into_iter().rev().peekable();
2076 let mut result = None;
2077 // Find the last modern mark from the end if it exists.
2078 while let Some(&(mark, transparency)) = iter.peek() {
2079 if transparency == Transparency::Opaque {
2080 result = Some(mark);
2086 // Then find the last legacy mark from the end if it exists.
2087 for (mark, transparency) in iter {
2088 if transparency == Transparency::SemiTransparent {
2089 result = Some(mark);
2096 ctxt = ctxt.modern();
2097 ctxt.adjust(Mark::root())
2099 let module = match mark {
2100 Some(def) => self.macro_def_scope(def),
2101 None => return self.graph_root,
2103 self.get_module(DefId { index: CRATE_DEF_INDEX, ..module.normal_ancestor_id })
2106 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
2107 let mut module = self.get_module(module.normal_ancestor_id);
2108 while module.span.ctxt().modern() != *ctxt {
2109 let parent = module.parent.unwrap_or_else(|| self.macro_def_scope(ctxt.remove_mark()));
2110 module = self.get_module(parent.normal_ancestor_id);
2117 // We maintain a list of value ribs and type ribs.
2119 // Simultaneously, we keep track of the current position in the module
2120 // graph in the `current_module` pointer. When we go to resolve a name in
2121 // the value or type namespaces, we first look through all the ribs and
2122 // then query the module graph. When we resolve a name in the module
2123 // namespace, we can skip all the ribs (since nested modules are not
2124 // allowed within blocks in Rust) and jump straight to the current module
2127 // Named implementations are handled separately. When we find a method
2128 // call, we consult the module node to find all of the implementations in
2129 // scope. This information is lazily cached in the module node. We then
2130 // generate a fake "implementation scope" containing all the
2131 // implementations thus found, for compatibility with old resolve pass.
2133 pub fn with_scope<F, T>(&mut self, id: NodeId, f: F) -> T
2134 where F: FnOnce(&mut Resolver) -> T
2136 let id = self.definitions.local_def_id(id);
2137 let module = self.module_map.get(&id).cloned(); // clones a reference
2138 if let Some(module) = module {
2139 // Move down in the graph.
2140 let orig_module = replace(&mut self.current_module, module);
2141 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(module)));
2142 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(module)));
2144 self.finalize_current_module_macro_resolutions();
2147 self.current_module = orig_module;
2148 self.ribs[ValueNS].pop();
2149 self.ribs[TypeNS].pop();
2156 /// Searches the current set of local scopes for labels. Returns the first non-None label that
2157 /// is returned by the given predicate function
2159 /// Stops after meeting a closure.
2160 fn search_label<P, R>(&self, mut ident: Ident, pred: P) -> Option<R>
2161 where P: Fn(&Rib, Ident) -> Option<R>
2163 for rib in self.label_ribs.iter().rev() {
2166 // If an invocation of this macro created `ident`, give up on `ident`
2167 // and switch to `ident`'s source from the macro definition.
2168 MacroDefinition(def) => {
2169 if def == self.macro_def(ident.span.ctxt()) {
2170 ident.span.remove_mark();
2174 // Do not resolve labels across function boundary
2178 let r = pred(rib, ident);
2186 fn resolve_item(&mut self, item: &Item) {
2187 let name = item.ident.name;
2188 debug!("(resolving item) resolving {}", name);
2191 ItemKind::Ty(_, ref generics) |
2192 ItemKind::Fn(_, _, ref generics, _) |
2193 ItemKind::Existential(_, ref generics) => {
2194 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind),
2195 |this| visit::walk_item(this, item));
2198 ItemKind::Enum(_, ref generics) |
2199 ItemKind::Struct(_, ref generics) |
2200 ItemKind::Union(_, ref generics) => {
2201 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2202 let item_def_id = this.definitions.local_def_id(item.id);
2203 if this.session.features_untracked().self_in_typedefs {
2204 this.with_self_rib(Def::SelfTy(None, Some(item_def_id)), |this| {
2205 visit::walk_item(this, item);
2208 visit::walk_item(this, item);
2213 ItemKind::Impl(.., ref generics, ref opt_trait_ref, ref self_type, ref impl_items) =>
2214 self.resolve_implementation(generics,
2220 ItemKind::Trait(.., ref generics, ref bounds, ref trait_items) => {
2221 // Create a new rib for the trait-wide type parameters.
2222 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2223 let local_def_id = this.definitions.local_def_id(item.id);
2224 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2225 this.visit_generics(generics);
2226 walk_list!(this, visit_param_bound, bounds);
2228 for trait_item in trait_items {
2229 let type_parameters = HasTypeParameters(&trait_item.generics,
2230 TraitOrImplItemRibKind);
2231 this.with_type_parameter_rib(type_parameters, |this| {
2232 match trait_item.node {
2233 TraitItemKind::Const(ref ty, ref default) => {
2236 // Only impose the restrictions of
2237 // ConstRibKind for an actual constant
2238 // expression in a provided default.
2239 if let Some(ref expr) = *default{
2240 this.with_constant_rib(|this| {
2241 this.visit_expr(expr);
2245 TraitItemKind::Method(_, _) => {
2246 visit::walk_trait_item(this, trait_item)
2248 TraitItemKind::Type(..) => {
2249 visit::walk_trait_item(this, trait_item)
2251 TraitItemKind::Macro(_) => {
2252 panic!("unexpanded macro in resolve!")
2261 ItemKind::TraitAlias(ref generics, ref bounds) => {
2262 // Create a new rib for the trait-wide type parameters.
2263 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2264 let local_def_id = this.definitions.local_def_id(item.id);
2265 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2266 this.visit_generics(generics);
2267 walk_list!(this, visit_param_bound, bounds);
2272 ItemKind::Mod(_) | ItemKind::ForeignMod(_) => {
2273 self.with_scope(item.id, |this| {
2274 visit::walk_item(this, item);
2278 ItemKind::Static(ref ty, _, ref expr) |
2279 ItemKind::Const(ref ty, ref expr) => {
2280 self.with_item_rib(|this| {
2282 this.with_constant_rib(|this| {
2283 this.visit_expr(expr);
2288 ItemKind::Use(ref use_tree) => {
2289 // Imports are resolved as global by default, add starting root segment.
2291 segments: use_tree.prefix.make_root().into_iter().collect(),
2292 span: use_tree.span,
2294 self.resolve_use_tree(item.id, use_tree.span, item.id, use_tree, &path);
2297 ItemKind::ExternCrate(_) | ItemKind::MacroDef(..) | ItemKind::GlobalAsm(_) => {
2298 // do nothing, these are just around to be encoded
2301 ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"),
2305 /// For the most part, use trees are desugared into `ImportDirective` instances
2306 /// when building the reduced graph (see `build_reduced_graph_for_use_tree`). But
2307 /// there is one special case we handle here: an empty nested import like
2308 /// `a::{b::{}}`, which desugares into...no import directives.
2309 fn resolve_use_tree(
2314 use_tree: &ast::UseTree,
2317 match use_tree.kind {
2318 ast::UseTreeKind::Nested(ref items) => {
2320 segments: prefix.segments
2322 .chain(use_tree.prefix.segments.iter())
2325 span: prefix.span.to(use_tree.prefix.span),
2328 if items.len() == 0 {
2329 // Resolve prefix of an import with empty braces (issue #28388).
2330 self.smart_resolve_path_with_crate_lint(
2334 PathSource::ImportPrefix,
2335 CrateLint::UsePath { root_id, root_span },
2338 for &(ref tree, nested_id) in items {
2339 self.resolve_use_tree(root_id, root_span, nested_id, tree, &path);
2343 ast::UseTreeKind::Simple(..) => {},
2344 ast::UseTreeKind::Glob => {},
2348 fn with_type_parameter_rib<'b, F>(&'b mut self, type_parameters: TypeParameters<'a, 'b>, f: F)
2349 where F: FnOnce(&mut Resolver)
2351 match type_parameters {
2352 HasTypeParameters(generics, rib_kind) => {
2353 let mut function_type_rib = Rib::new(rib_kind);
2354 let mut seen_bindings = FxHashMap();
2355 for param in &generics.params {
2357 GenericParamKind::Lifetime { .. } => {}
2358 GenericParamKind::Type { .. } => {
2359 let ident = param.ident.modern();
2360 debug!("with_type_parameter_rib: {}", param.id);
2362 if seen_bindings.contains_key(&ident) {
2363 let span = seen_bindings.get(&ident).unwrap();
2364 let err = ResolutionError::NameAlreadyUsedInTypeParameterList(
2368 resolve_error(self, param.ident.span, err);
2370 seen_bindings.entry(ident).or_insert(param.ident.span);
2372 // Plain insert (no renaming).
2373 let def = Def::TyParam(self.definitions.local_def_id(param.id));
2374 function_type_rib.bindings.insert(ident, def);
2375 self.record_def(param.id, PathResolution::new(def));
2379 self.ribs[TypeNS].push(function_type_rib);
2382 NoTypeParameters => {
2389 if let HasTypeParameters(..) = type_parameters {
2390 self.ribs[TypeNS].pop();
2394 fn with_label_rib<F>(&mut self, f: F)
2395 where F: FnOnce(&mut Resolver)
2397 self.label_ribs.push(Rib::new(NormalRibKind));
2399 self.label_ribs.pop();
2402 fn with_item_rib<F>(&mut self, f: F)
2403 where F: FnOnce(&mut Resolver)
2405 self.ribs[ValueNS].push(Rib::new(ItemRibKind));
2406 self.ribs[TypeNS].push(Rib::new(ItemRibKind));
2408 self.ribs[TypeNS].pop();
2409 self.ribs[ValueNS].pop();
2412 fn with_constant_rib<F>(&mut self, f: F)
2413 where F: FnOnce(&mut Resolver)
2415 self.ribs[ValueNS].push(Rib::new(ConstantItemRibKind));
2416 self.label_ribs.push(Rib::new(ConstantItemRibKind));
2418 self.label_ribs.pop();
2419 self.ribs[ValueNS].pop();
2422 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2423 where F: FnOnce(&mut Resolver) -> T
2425 // Handle nested impls (inside fn bodies)
2426 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2427 let result = f(self);
2428 self.current_self_type = previous_value;
2432 /// This is called to resolve a trait reference from an `impl` (i.e. `impl Trait for Foo`)
2433 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
2434 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2436 let mut new_val = None;
2437 let mut new_id = None;
2438 if let Some(trait_ref) = opt_trait_ref {
2439 let path: Vec<_> = trait_ref.path.segments.iter()
2440 .map(|seg| seg.ident)
2442 let def = self.smart_resolve_path_fragment(
2446 trait_ref.path.span,
2447 PathSource::Trait(AliasPossibility::No),
2448 CrateLint::SimplePath(trait_ref.ref_id),
2450 if def != Def::Err {
2451 new_id = Some(def.def_id());
2452 let span = trait_ref.path.span;
2453 if let PathResult::Module(ModuleOrUniformRoot::Module(module)) =
2460 CrateLint::SimplePath(trait_ref.ref_id),
2463 new_val = Some((module, trait_ref.clone()));
2467 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2468 let result = f(self, new_id);
2469 self.current_trait_ref = original_trait_ref;
2473 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2474 where F: FnOnce(&mut Resolver)
2476 let mut self_type_rib = Rib::new(NormalRibKind);
2478 // plain insert (no renaming, types are not currently hygienic....)
2479 self_type_rib.bindings.insert(keywords::SelfType.ident(), self_def);
2480 self.ribs[TypeNS].push(self_type_rib);
2482 self.ribs[TypeNS].pop();
2485 fn resolve_implementation(&mut self,
2486 generics: &Generics,
2487 opt_trait_reference: &Option<TraitRef>,
2490 impl_items: &[ImplItem]) {
2491 // If applicable, create a rib for the type parameters.
2492 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2493 // Dummy self type for better errors if `Self` is used in the trait path.
2494 this.with_self_rib(Def::SelfTy(None, None), |this| {
2495 // Resolve the trait reference, if necessary.
2496 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2497 let item_def_id = this.definitions.local_def_id(item_id);
2498 this.with_self_rib(Def::SelfTy(trait_id, Some(item_def_id)), |this| {
2499 if let Some(trait_ref) = opt_trait_reference.as_ref() {
2500 // Resolve type arguments in the trait path.
2501 visit::walk_trait_ref(this, trait_ref);
2503 // Resolve the self type.
2504 this.visit_ty(self_type);
2505 // Resolve the type parameters.
2506 this.visit_generics(generics);
2507 // Resolve the items within the impl.
2508 this.with_current_self_type(self_type, |this| {
2509 for impl_item in impl_items {
2510 this.resolve_visibility(&impl_item.vis);
2512 // We also need a new scope for the impl item type parameters.
2513 let type_parameters = HasTypeParameters(&impl_item.generics,
2514 TraitOrImplItemRibKind);
2515 this.with_type_parameter_rib(type_parameters, |this| {
2516 use self::ResolutionError::*;
2517 match impl_item.node {
2518 ImplItemKind::Const(..) => {
2519 // If this is a trait impl, ensure the const
2521 this.check_trait_item(impl_item.ident,
2524 |n, s| ConstNotMemberOfTrait(n, s));
2525 this.with_constant_rib(|this|
2526 visit::walk_impl_item(this, impl_item)
2529 ImplItemKind::Method(..) => {
2530 // If this is a trait impl, ensure the method
2532 this.check_trait_item(impl_item.ident,
2535 |n, s| MethodNotMemberOfTrait(n, s));
2537 visit::walk_impl_item(this, impl_item);
2539 ImplItemKind::Type(ref ty) => {
2540 // If this is a trait impl, ensure the type
2542 this.check_trait_item(impl_item.ident,
2545 |n, s| TypeNotMemberOfTrait(n, s));
2549 ImplItemKind::Existential(ref bounds) => {
2550 // If this is a trait impl, ensure the type
2552 this.check_trait_item(impl_item.ident,
2555 |n, s| TypeNotMemberOfTrait(n, s));
2557 for bound in bounds {
2558 this.visit_param_bound(bound);
2561 ImplItemKind::Macro(_) =>
2562 panic!("unexpanded macro in resolve!"),
2573 fn check_trait_item<F>(&mut self, ident: Ident, ns: Namespace, span: Span, err: F)
2574 where F: FnOnce(Name, &str) -> ResolutionError
2576 // If there is a TraitRef in scope for an impl, then the method must be in the
2578 if let Some((module, _)) = self.current_trait_ref {
2579 if self.resolve_ident_in_module(
2580 ModuleOrUniformRoot::Module(module),
2586 let path = &self.current_trait_ref.as_ref().unwrap().1.path;
2587 resolve_error(self, span, err(ident.name, &path_names_to_string(path)));
2592 fn resolve_local(&mut self, local: &Local) {
2593 // Resolve the type.
2594 walk_list!(self, visit_ty, &local.ty);
2596 // Resolve the initializer.
2597 walk_list!(self, visit_expr, &local.init);
2599 // Resolve the pattern.
2600 self.resolve_pattern(&local.pat, PatternSource::Let, &mut FxHashMap());
2603 // build a map from pattern identifiers to binding-info's.
2604 // this is done hygienically. This could arise for a macro
2605 // that expands into an or-pattern where one 'x' was from the
2606 // user and one 'x' came from the macro.
2607 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2608 let mut binding_map = FxHashMap();
2610 pat.walk(&mut |pat| {
2611 if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node {
2612 if sub_pat.is_some() || match self.def_map.get(&pat.id).map(|res| res.base_def()) {
2613 Some(Def::Local(..)) => true,
2616 let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode };
2617 binding_map.insert(ident, binding_info);
2626 // check that all of the arms in an or-pattern have exactly the
2627 // same set of bindings, with the same binding modes for each.
2628 fn check_consistent_bindings(&mut self, pats: &[P<Pat>]) {
2629 if pats.is_empty() {
2633 let mut missing_vars = FxHashMap();
2634 let mut inconsistent_vars = FxHashMap();
2635 for (i, p) in pats.iter().enumerate() {
2636 let map_i = self.binding_mode_map(&p);
2638 for (j, q) in pats.iter().enumerate() {
2643 let map_j = self.binding_mode_map(&q);
2644 for (&key, &binding_i) in &map_i {
2645 if map_j.len() == 0 { // Account for missing bindings when
2646 let binding_error = missing_vars // map_j has none.
2648 .or_insert(BindingError {
2650 origin: BTreeSet::new(),
2651 target: BTreeSet::new(),
2653 binding_error.origin.insert(binding_i.span);
2654 binding_error.target.insert(q.span);
2656 for (&key_j, &binding_j) in &map_j {
2657 match map_i.get(&key_j) {
2658 None => { // missing binding
2659 let binding_error = missing_vars
2661 .or_insert(BindingError {
2663 origin: BTreeSet::new(),
2664 target: BTreeSet::new(),
2666 binding_error.origin.insert(binding_j.span);
2667 binding_error.target.insert(p.span);
2669 Some(binding_i) => { // check consistent binding
2670 if binding_i.binding_mode != binding_j.binding_mode {
2673 .or_insert((binding_j.span, binding_i.span));
2681 let mut missing_vars = missing_vars.iter().collect::<Vec<_>>();
2682 missing_vars.sort();
2683 for (_, v) in missing_vars {
2685 *v.origin.iter().next().unwrap(),
2686 ResolutionError::VariableNotBoundInPattern(v));
2688 let mut inconsistent_vars = inconsistent_vars.iter().collect::<Vec<_>>();
2689 inconsistent_vars.sort();
2690 for (name, v) in inconsistent_vars {
2691 resolve_error(self, v.0, ResolutionError::VariableBoundWithDifferentMode(*name, v.1));
2695 fn resolve_arm(&mut self, arm: &Arm) {
2696 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2698 let mut bindings_list = FxHashMap();
2699 for pattern in &arm.pats {
2700 self.resolve_pattern(&pattern, PatternSource::Match, &mut bindings_list);
2703 // This has to happen *after* we determine which pat_idents are variants
2704 self.check_consistent_bindings(&arm.pats);
2707 Some(ast::Guard::If(ref expr)) => self.visit_expr(expr),
2710 self.visit_expr(&arm.body);
2712 self.ribs[ValueNS].pop();
2715 fn resolve_block(&mut self, block: &Block) {
2716 debug!("(resolving block) entering block");
2717 // Move down in the graph, if there's an anonymous module rooted here.
2718 let orig_module = self.current_module;
2719 let anonymous_module = self.block_map.get(&block.id).cloned(); // clones a reference
2721 let mut num_macro_definition_ribs = 0;
2722 if let Some(anonymous_module) = anonymous_module {
2723 debug!("(resolving block) found anonymous module, moving down");
2724 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2725 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2726 self.current_module = anonymous_module;
2727 self.finalize_current_module_macro_resolutions();
2729 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2732 // Descend into the block.
2733 for stmt in &block.stmts {
2734 if let ast::StmtKind::Item(ref item) = stmt.node {
2735 if let ast::ItemKind::MacroDef(..) = item.node {
2736 num_macro_definition_ribs += 1;
2737 let def = self.definitions.local_def_id(item.id);
2738 self.ribs[ValueNS].push(Rib::new(MacroDefinition(def)));
2739 self.label_ribs.push(Rib::new(MacroDefinition(def)));
2743 self.visit_stmt(stmt);
2747 self.current_module = orig_module;
2748 for _ in 0 .. num_macro_definition_ribs {
2749 self.ribs[ValueNS].pop();
2750 self.label_ribs.pop();
2752 self.ribs[ValueNS].pop();
2753 if anonymous_module.is_some() {
2754 self.ribs[TypeNS].pop();
2756 debug!("(resolving block) leaving block");
2759 fn fresh_binding(&mut self,
2762 outer_pat_id: NodeId,
2763 pat_src: PatternSource,
2764 bindings: &mut FxHashMap<Ident, NodeId>)
2766 // Add the binding to the local ribs, if it
2767 // doesn't already exist in the bindings map. (We
2768 // must not add it if it's in the bindings map
2769 // because that breaks the assumptions later
2770 // passes make about or-patterns.)
2771 let ident = ident.modern_and_legacy();
2772 let mut def = Def::Local(pat_id);
2773 match bindings.get(&ident).cloned() {
2774 Some(id) if id == outer_pat_id => {
2775 // `Variant(a, a)`, error
2779 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2783 Some(..) if pat_src == PatternSource::FnParam => {
2784 // `fn f(a: u8, a: u8)`, error
2788 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2792 Some(..) if pat_src == PatternSource::Match ||
2793 pat_src == PatternSource::IfLet ||
2794 pat_src == PatternSource::WhileLet => {
2795 // `Variant1(a) | Variant2(a)`, ok
2796 // Reuse definition from the first `a`.
2797 def = self.ribs[ValueNS].last_mut().unwrap().bindings[&ident];
2800 span_bug!(ident.span, "two bindings with the same name from \
2801 unexpected pattern source {:?}", pat_src);
2804 // A completely fresh binding, add to the lists if it's valid.
2805 if ident.name != keywords::Invalid.name() {
2806 bindings.insert(ident, outer_pat_id);
2807 self.ribs[ValueNS].last_mut().unwrap().bindings.insert(ident, def);
2812 PathResolution::new(def)
2815 fn resolve_pattern(&mut self,
2817 pat_src: PatternSource,
2818 // Maps idents to the node ID for the
2819 // outermost pattern that binds them.
2820 bindings: &mut FxHashMap<Ident, NodeId>) {
2821 // Visit all direct subpatterns of this pattern.
2822 let outer_pat_id = pat.id;
2823 pat.walk(&mut |pat| {
2825 PatKind::Ident(bmode, ident, ref opt_pat) => {
2826 // First try to resolve the identifier as some existing
2827 // entity, then fall back to a fresh binding.
2828 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS,
2830 .and_then(LexicalScopeBinding::item);
2831 let resolution = binding.map(NameBinding::def).and_then(|def| {
2832 let is_syntactic_ambiguity = opt_pat.is_none() &&
2833 bmode == BindingMode::ByValue(Mutability::Immutable);
2835 Def::StructCtor(_, CtorKind::Const) |
2836 Def::VariantCtor(_, CtorKind::Const) |
2837 Def::Const(..) if is_syntactic_ambiguity => {
2838 // Disambiguate in favor of a unit struct/variant
2839 // or constant pattern.
2840 self.record_use(ident, ValueNS, binding.unwrap(), ident.span);
2841 Some(PathResolution::new(def))
2843 Def::StructCtor(..) | Def::VariantCtor(..) |
2844 Def::Const(..) | Def::Static(..) => {
2845 // This is unambiguously a fresh binding, either syntactically
2846 // (e.g. `IDENT @ PAT` or `ref IDENT`) or because `IDENT` resolves
2847 // to something unusable as a pattern (e.g. constructor function),
2848 // but we still conservatively report an error, see
2849 // issues/33118#issuecomment-233962221 for one reason why.
2853 ResolutionError::BindingShadowsSomethingUnacceptable(
2854 pat_src.descr(), ident.name, binding.unwrap())
2858 Def::Fn(..) | Def::Err => {
2859 // These entities are explicitly allowed
2860 // to be shadowed by fresh bindings.
2864 span_bug!(ident.span, "unexpected definition for an \
2865 identifier in pattern: {:?}", def);
2868 }).unwrap_or_else(|| {
2869 self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings)
2872 self.record_def(pat.id, resolution);
2875 PatKind::TupleStruct(ref path, ..) => {
2876 self.smart_resolve_path(pat.id, None, path, PathSource::TupleStruct);
2879 PatKind::Path(ref qself, ref path) => {
2880 self.smart_resolve_path(pat.id, qself.as_ref(), path, PathSource::Pat);
2883 PatKind::Struct(ref path, ..) => {
2884 self.smart_resolve_path(pat.id, None, path, PathSource::Struct);
2892 visit::walk_pat(self, pat);
2895 // High-level and context dependent path resolution routine.
2896 // Resolves the path and records the resolution into definition map.
2897 // If resolution fails tries several techniques to find likely
2898 // resolution candidates, suggest imports or other help, and report
2899 // errors in user friendly way.
2900 fn smart_resolve_path(&mut self,
2902 qself: Option<&QSelf>,
2906 self.smart_resolve_path_with_crate_lint(id, qself, path, source, CrateLint::SimplePath(id))
2909 /// A variant of `smart_resolve_path` where you also specify extra
2910 /// information about where the path came from; this extra info is
2911 /// sometimes needed for the lint that recommends rewriting
2912 /// absolute paths to `crate`, so that it knows how to frame the
2913 /// suggestion. If you are just resolving a path like `foo::bar`
2914 /// that appears...somewhere, though, then you just want
2915 /// `CrateLint::SimplePath`, which is what `smart_resolve_path`
2916 /// already provides.
2917 fn smart_resolve_path_with_crate_lint(
2920 qself: Option<&QSelf>,
2923 crate_lint: CrateLint
2924 ) -> PathResolution {
2925 let segments = &path.segments.iter()
2926 .map(|seg| seg.ident)
2927 .collect::<Vec<_>>();
2928 self.smart_resolve_path_fragment(id, qself, segments, path.span, source, crate_lint)
2931 fn smart_resolve_path_fragment(&mut self,
2933 qself: Option<&QSelf>,
2937 crate_lint: CrateLint)
2939 let ident_span = path.last().map_or(span, |ident| ident.span);
2940 let ns = source.namespace();
2941 let is_expected = &|def| source.is_expected(def);
2942 let is_enum_variant = &|def| if let Def::Variant(..) = def { true } else { false };
2944 // Base error is amended with one short label and possibly some longer helps/notes.
2945 let report_errors = |this: &mut Self, def: Option<Def>| {
2946 // Make the base error.
2947 let expected = source.descr_expected();
2948 let path_str = names_to_string(path);
2949 let code = source.error_code(def.is_some());
2950 let (base_msg, fallback_label, base_span) = if let Some(def) = def {
2951 (format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str),
2952 format!("not a {}", expected),
2955 let item_str = path[path.len() - 1];
2956 let item_span = path[path.len() - 1].span;
2957 let (mod_prefix, mod_str) = if path.len() == 1 {
2958 (String::new(), "this scope".to_string())
2959 } else if path.len() == 2 && path[0].name == keywords::CrateRoot.name() {
2960 (String::new(), "the crate root".to_string())
2962 let mod_path = &path[..path.len() - 1];
2963 let mod_prefix = match this.resolve_path(None, mod_path, Some(TypeNS),
2964 false, span, CrateLint::No) {
2965 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
2968 }.map_or(String::new(), |def| format!("{} ", def.kind_name()));
2969 (mod_prefix, format!("`{}`", names_to_string(mod_path)))
2971 (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str),
2972 format!("not found in {}", mod_str),
2975 let code = DiagnosticId::Error(code.into());
2976 let mut err = this.session.struct_span_err_with_code(base_span, &base_msg, code);
2978 // Emit special messages for unresolved `Self` and `self`.
2979 if is_self_type(path, ns) {
2980 __diagnostic_used!(E0411);
2981 err.code(DiagnosticId::Error("E0411".into()));
2982 let available_in = if this.session.features_untracked().self_in_typedefs {
2983 "impls, traits, and type definitions"
2987 err.span_label(span, format!("`Self` is only available in {}", available_in));
2988 return (err, Vec::new());
2990 if is_self_value(path, ns) {
2991 __diagnostic_used!(E0424);
2992 err.code(DiagnosticId::Error("E0424".into()));
2993 err.span_label(span, format!("`self` value is only available in \
2994 methods with `self` parameter"));
2995 return (err, Vec::new());
2998 // Try to lookup the name in more relaxed fashion for better error reporting.
2999 let ident = *path.last().unwrap();
3000 let candidates = this.lookup_import_candidates(ident.name, ns, is_expected);
3001 if candidates.is_empty() && is_expected(Def::Enum(DefId::local(CRATE_DEF_INDEX))) {
3002 let enum_candidates =
3003 this.lookup_import_candidates(ident.name, ns, is_enum_variant);
3004 let mut enum_candidates = enum_candidates.iter()
3005 .map(|suggestion| import_candidate_to_paths(&suggestion)).collect::<Vec<_>>();
3006 enum_candidates.sort();
3007 for (sp, variant_path, enum_path) in enum_candidates {
3009 let msg = format!("there is an enum variant `{}`, \
3015 err.span_suggestion_with_applicability(
3017 "you can try using the variant's enum",
3019 Applicability::MachineApplicable,
3024 if path.len() == 1 && this.self_type_is_available(span) {
3025 if let Some(candidate) = this.lookup_assoc_candidate(ident, ns, is_expected) {
3026 let self_is_available = this.self_value_is_available(path[0].span, span);
3028 AssocSuggestion::Field => {
3029 err.span_suggestion_with_applicability(
3032 format!("self.{}", path_str),
3033 Applicability::MachineApplicable,
3035 if !self_is_available {
3036 err.span_label(span, format!("`self` value is only available in \
3037 methods with `self` parameter"));
3040 AssocSuggestion::MethodWithSelf if self_is_available => {
3041 err.span_suggestion_with_applicability(
3044 format!("self.{}", path_str),
3045 Applicability::MachineApplicable,
3048 AssocSuggestion::MethodWithSelf | AssocSuggestion::AssocItem => {
3049 err.span_suggestion_with_applicability(
3052 format!("Self::{}", path_str),
3053 Applicability::MachineApplicable,
3057 return (err, candidates);
3061 let mut levenshtein_worked = false;
3064 if let Some(candidate) = this.lookup_typo_candidate(path, ns, is_expected, span) {
3065 err.span_label(ident_span, format!("did you mean `{}`?", candidate));
3066 levenshtein_worked = true;
3069 // Try context dependent help if relaxed lookup didn't work.
3070 if let Some(def) = def {
3071 match (def, source) {
3072 (Def::Macro(..), _) => {
3073 err.span_label(span, format!("did you mean `{}!(...)`?", path_str));
3074 return (err, candidates);
3076 (Def::TyAlias(..), PathSource::Trait(_)) => {
3077 err.span_label(span, "type aliases cannot be used for traits");
3078 return (err, candidates);
3080 (Def::Mod(..), PathSource::Expr(Some(parent))) => match parent.node {
3081 ExprKind::Field(_, ident) => {
3082 err.span_label(parent.span, format!("did you mean `{}::{}`?",
3084 return (err, candidates);
3086 ExprKind::MethodCall(ref segment, ..) => {
3087 err.span_label(parent.span, format!("did you mean `{}::{}(...)`?",
3088 path_str, segment.ident));
3089 return (err, candidates);
3093 (Def::Enum(..), PathSource::TupleStruct)
3094 | (Def::Enum(..), PathSource::Expr(..)) => {
3095 if let Some(variants) = this.collect_enum_variants(def) {
3096 err.note(&format!("did you mean to use one \
3097 of the following variants?\n{}",
3099 .map(|suggestion| path_names_to_string(suggestion))
3100 .map(|suggestion| format!("- `{}`", suggestion))
3101 .collect::<Vec<_>>()
3105 err.note("did you mean to use one of the enum's variants?");
3107 return (err, candidates);
3109 (Def::Struct(def_id), _) if ns == ValueNS => {
3110 if let Some((ctor_def, ctor_vis))
3111 = this.struct_constructors.get(&def_id).cloned() {
3112 let accessible_ctor = this.is_accessible(ctor_vis);
3113 if is_expected(ctor_def) && !accessible_ctor {
3114 err.span_label(span, format!("constructor is not visible \
3115 here due to private fields"));
3118 // HACK(estebank): find a better way to figure out that this was a
3119 // parser issue where a struct literal is being used on an expression
3120 // where a brace being opened means a block is being started. Look
3121 // ahead for the next text to see if `span` is followed by a `{`.
3122 let cm = this.session.source_map();
3125 sp = cm.next_point(sp);
3126 match cm.span_to_snippet(sp) {
3127 Ok(ref snippet) => {
3128 if snippet.chars().any(|c| { !c.is_whitespace() }) {
3135 let followed_by_brace = match cm.span_to_snippet(sp) {
3136 Ok(ref snippet) if snippet == "{" => true,
3139 if let (PathSource::Expr(None), true) = (source, followed_by_brace) {
3142 format!("did you mean `({} {{ /* fields */ }})`?", path_str),
3147 format!("did you mean `{} {{ /* fields */ }}`?", path_str),
3151 return (err, candidates);
3153 (Def::Union(..), _) |
3154 (Def::Variant(..), _) |
3155 (Def::VariantCtor(_, CtorKind::Fictive), _) if ns == ValueNS => {
3156 err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?",
3158 return (err, candidates);
3160 (Def::SelfTy(..), _) if ns == ValueNS => {
3161 err.span_label(span, fallback_label);
3162 err.note("can't use `Self` as a constructor, you must use the \
3163 implemented struct");
3164 return (err, candidates);
3166 (Def::TyAlias(_), _) | (Def::AssociatedTy(..), _) if ns == ValueNS => {
3167 err.note("can't use a type alias as a constructor");
3168 return (err, candidates);
3175 if !levenshtein_worked {
3176 err.span_label(base_span, fallback_label);
3177 this.type_ascription_suggestion(&mut err, base_span);
3181 let report_errors = |this: &mut Self, def: Option<Def>| {
3182 let (err, candidates) = report_errors(this, def);
3183 let def_id = this.current_module.normal_ancestor_id;
3184 let node_id = this.definitions.as_local_node_id(def_id).unwrap();
3185 let better = def.is_some();
3186 this.use_injections.push(UseError { err, candidates, node_id, better });
3187 err_path_resolution()
3190 let resolution = match self.resolve_qpath_anywhere(
3196 source.defer_to_typeck(),
3197 source.global_by_default(),
3200 Some(resolution) if resolution.unresolved_segments() == 0 => {
3201 if is_expected(resolution.base_def()) || resolution.base_def() == Def::Err {
3204 // Add a temporary hack to smooth the transition to new struct ctor
3205 // visibility rules. See #38932 for more details.
3207 if let Def::Struct(def_id) = resolution.base_def() {
3208 if let Some((ctor_def, ctor_vis))
3209 = self.struct_constructors.get(&def_id).cloned() {
3210 if is_expected(ctor_def) && self.is_accessible(ctor_vis) {
3211 let lint = lint::builtin::LEGACY_CONSTRUCTOR_VISIBILITY;
3212 self.session.buffer_lint(lint, id, span,
3213 "private struct constructors are not usable through \
3214 re-exports in outer modules",
3216 res = Some(PathResolution::new(ctor_def));
3221 res.unwrap_or_else(|| report_errors(self, Some(resolution.base_def())))
3224 Some(resolution) if source.defer_to_typeck() => {
3225 // Not fully resolved associated item `T::A::B` or `<T as Tr>::A::B`
3226 // or `<T>::A::B`. If `B` should be resolved in value namespace then
3227 // it needs to be added to the trait map.
3229 let item_name = *path.last().unwrap();
3230 let traits = self.get_traits_containing_item(item_name, ns);
3231 self.trait_map.insert(id, traits);
3235 _ => report_errors(self, None)
3238 if let PathSource::TraitItem(..) = source {} else {
3239 // Avoid recording definition of `A::B` in `<T as A>::B::C`.
3240 self.record_def(id, resolution);
3245 fn type_ascription_suggestion(&self,
3246 err: &mut DiagnosticBuilder,
3248 debug!("type_ascription_suggetion {:?}", base_span);
3249 let cm = self.session.source_map();
3250 debug!("self.current_type_ascription {:?}", self.current_type_ascription);
3251 if let Some(sp) = self.current_type_ascription.last() {
3253 loop { // try to find the `:`, bail on first non-':'/non-whitespace
3254 sp = cm.next_point(sp);
3255 if let Ok(snippet) = cm.span_to_snippet(sp.to(cm.next_point(sp))) {
3256 debug!("snippet {:?}", snippet);
3257 let line_sp = cm.lookup_char_pos(sp.hi()).line;
3258 let line_base_sp = cm.lookup_char_pos(base_span.lo()).line;
3259 debug!("{:?} {:?}", line_sp, line_base_sp);
3261 err.span_label(base_span,
3262 "expecting a type here because of type ascription");
3263 if line_sp != line_base_sp {
3264 err.span_suggestion_short(sp,
3265 "did you mean to use `;` here instead?",
3269 } else if snippet.trim().len() != 0 {
3270 debug!("tried to find type ascription `:` token, couldn't find it");
3280 fn self_type_is_available(&mut self, span: Span) -> bool {
3281 let binding = self.resolve_ident_in_lexical_scope(keywords::SelfType.ident(),
3282 TypeNS, None, span);
3283 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
3286 fn self_value_is_available(&mut self, self_span: Span, path_span: Span) -> bool {
3287 let ident = Ident::new(keywords::SelfValue.name(), self_span);
3288 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, None, path_span);
3289 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
3292 // Resolve in alternative namespaces if resolution in the primary namespace fails.
3293 fn resolve_qpath_anywhere(&mut self,
3295 qself: Option<&QSelf>,
3297 primary_ns: Namespace,
3299 defer_to_typeck: bool,
3300 global_by_default: bool,
3301 crate_lint: CrateLint)
3302 -> Option<PathResolution> {
3303 let mut fin_res = None;
3304 // FIXME: can't resolve paths in macro namespace yet, macros are
3305 // processed by the little special hack below.
3306 for (i, ns) in [primary_ns, TypeNS, ValueNS, /*MacroNS*/].iter().cloned().enumerate() {
3307 if i == 0 || ns != primary_ns {
3308 match self.resolve_qpath(id, qself, path, ns, span, global_by_default, crate_lint) {
3309 // If defer_to_typeck, then resolution > no resolution,
3310 // otherwise full resolution > partial resolution > no resolution.
3311 Some(res) if res.unresolved_segments() == 0 || defer_to_typeck =>
3313 res => if fin_res.is_none() { fin_res = res },
3317 let is_global = self.macro_prelude.get(&path[0].name).cloned()
3318 .map(|binding| binding.get_macro(self).kind() == MacroKind::Bang).unwrap_or(false);
3319 if primary_ns != MacroNS && (is_global ||
3320 self.macro_names.contains(&path[0].modern())) {
3321 // Return some dummy definition, it's enough for error reporting.
3323 PathResolution::new(Def::Macro(DefId::local(CRATE_DEF_INDEX), MacroKind::Bang))
3329 /// Handles paths that may refer to associated items.
3330 fn resolve_qpath(&mut self,
3332 qself: Option<&QSelf>,
3336 global_by_default: bool,
3337 crate_lint: CrateLint)
3338 -> Option<PathResolution> {
3340 "resolve_qpath(id={:?}, qself={:?}, path={:?}, \
3341 ns={:?}, span={:?}, global_by_default={:?})",
3350 if let Some(qself) = qself {
3351 if qself.position == 0 {
3352 // This is a case like `<T>::B`, where there is no
3353 // trait to resolve. In that case, we leave the `B`
3354 // segment to be resolved by type-check.
3355 return Some(PathResolution::with_unresolved_segments(
3356 Def::Mod(DefId::local(CRATE_DEF_INDEX)), path.len()
3360 // Make sure `A::B` in `<T as A::B>::C` is a trait item.
3362 // Currently, `path` names the full item (`A::B::C`, in
3363 // our example). so we extract the prefix of that that is
3364 // the trait (the slice upto and including
3365 // `qself.position`). And then we recursively resolve that,
3366 // but with `qself` set to `None`.
3368 // However, setting `qself` to none (but not changing the
3369 // span) loses the information about where this path
3370 // *actually* appears, so for the purposes of the crate
3371 // lint we pass along information that this is the trait
3372 // name from a fully qualified path, and this also
3373 // contains the full span (the `CrateLint::QPathTrait`).
3374 let ns = if qself.position + 1 == path.len() { ns } else { TypeNS };
3375 let res = self.smart_resolve_path_fragment(
3378 &path[..qself.position + 1],
3380 PathSource::TraitItem(ns),
3381 CrateLint::QPathTrait {
3383 qpath_span: qself.path_span,
3387 // The remaining segments (the `C` in our example) will
3388 // have to be resolved by type-check, since that requires doing
3389 // trait resolution.
3390 return Some(PathResolution::with_unresolved_segments(
3391 res.base_def(), res.unresolved_segments() + path.len() - qself.position - 1
3395 let result = match self.resolve_path(
3403 PathResult::NonModule(path_res) => path_res,
3404 PathResult::Module(ModuleOrUniformRoot::Module(module)) if !module.is_normal() => {
3405 PathResolution::new(module.def().unwrap())
3407 // In `a(::assoc_item)*` `a` cannot be a module. If `a` does resolve to a module we
3408 // don't report an error right away, but try to fallback to a primitive type.
3409 // So, we are still able to successfully resolve something like
3411 // use std::u8; // bring module u8 in scope
3412 // fn f() -> u8 { // OK, resolves to primitive u8, not to std::u8
3413 // u8::max_value() // OK, resolves to associated function <u8>::max_value,
3414 // // not to non-existent std::u8::max_value
3417 // Such behavior is required for backward compatibility.
3418 // The same fallback is used when `a` resolves to nothing.
3419 PathResult::Module(ModuleOrUniformRoot::Module(_)) |
3420 PathResult::Failed(..)
3421 if (ns == TypeNS || path.len() > 1) &&
3422 self.primitive_type_table.primitive_types
3423 .contains_key(&path[0].name) => {
3424 let prim = self.primitive_type_table.primitive_types[&path[0].name];
3425 PathResolution::with_unresolved_segments(Def::PrimTy(prim), path.len() - 1)
3427 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
3428 PathResolution::new(module.def().unwrap()),
3429 PathResult::Failed(span, msg, false) => {
3430 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
3431 err_path_resolution()
3433 PathResult::Module(ModuleOrUniformRoot::UniformRoot(_)) |
3434 PathResult::Failed(..) => return None,
3435 PathResult::Indeterminate => bug!("indetermined path result in resolve_qpath"),
3438 if path.len() > 1 && !global_by_default && result.base_def() != Def::Err &&
3439 path[0].name != keywords::CrateRoot.name() &&
3440 path[0].name != keywords::DollarCrate.name() {
3441 let unqualified_result = {
3442 match self.resolve_path(
3444 &[*path.last().unwrap()],
3450 PathResult::NonModule(path_res) => path_res.base_def(),
3451 PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
3452 module.def().unwrap(),
3453 _ => return Some(result),
3456 if result.base_def() == unqualified_result {
3457 let lint = lint::builtin::UNUSED_QUALIFICATIONS;
3458 self.session.buffer_lint(lint, id, span, "unnecessary qualification")
3467 base_module: Option<ModuleOrUniformRoot<'a>>,
3469 opt_ns: Option<Namespace>, // `None` indicates a module path
3472 crate_lint: CrateLint,
3473 ) -> PathResult<'a> {
3474 let mut module = base_module;
3475 let mut allow_super = true;
3476 let mut second_binding = None;
3479 "resolve_path(path={:?}, opt_ns={:?}, record_used={:?}, \
3480 path_span={:?}, crate_lint={:?})",
3488 for (i, &ident) in path.iter().enumerate() {
3489 debug!("resolve_path ident {} {:?}", i, ident);
3490 let is_last = i == path.len() - 1;
3491 let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
3492 let name = ident.name;
3494 allow_super &= ns == TypeNS &&
3495 (name == keywords::SelfValue.name() ||
3496 name == keywords::Super.name());
3499 if allow_super && name == keywords::Super.name() {
3500 let mut ctxt = ident.span.ctxt().modern();
3501 let self_module = match i {
3502 0 => Some(self.resolve_self(&mut ctxt, self.current_module)),
3504 Some(ModuleOrUniformRoot::Module(module)) => Some(module),
3508 if let Some(self_module) = self_module {
3509 if let Some(parent) = self_module.parent {
3510 module = Some(ModuleOrUniformRoot::Module(
3511 self.resolve_self(&mut ctxt, parent)));
3515 let msg = "There are too many initial `super`s.".to_string();
3516 return PathResult::Failed(ident.span, msg, false);
3519 if name == keywords::SelfValue.name() {
3520 let mut ctxt = ident.span.ctxt().modern();
3521 module = Some(ModuleOrUniformRoot::Module(
3522 self.resolve_self(&mut ctxt, self.current_module)));
3525 if name == keywords::Extern.name() ||
3526 name == keywords::CrateRoot.name() &&
3527 self.session.features_untracked().extern_absolute_paths &&
3528 self.session.rust_2018() {
3529 module = Some(ModuleOrUniformRoot::UniformRoot(name));
3532 if name == keywords::CrateRoot.name() ||
3533 name == keywords::Crate.name() ||
3534 name == keywords::DollarCrate.name() {
3535 // `::a::b`, `crate::a::b` or `$crate::a::b`
3536 module = Some(ModuleOrUniformRoot::Module(
3537 self.resolve_crate_root(ident)));
3543 // Report special messages for path segment keywords in wrong positions.
3544 if ident.is_path_segment_keyword() && i != 0 {
3545 let name_str = if name == keywords::CrateRoot.name() {
3546 "crate root".to_string()
3548 format!("`{}`", name)
3550 let msg = if i == 1 && path[0].name == keywords::CrateRoot.name() {
3551 format!("global paths cannot start with {}", name_str)
3553 format!("{} in paths can only be used in start position", name_str)
3555 return PathResult::Failed(ident.span, msg, false);
3558 let binding = if let Some(module) = module {
3559 self.resolve_ident_in_module(module, ident, ns, record_used, path_span)
3560 } else if opt_ns == Some(MacroNS) {
3561 assert!(ns == TypeNS);
3562 self.resolve_lexical_macro_path_segment(ident, ns, record_used, record_used,
3563 false, path_span).map(|(b, _)| b)
3565 let record_used_id =
3566 if record_used { crate_lint.node_id().or(Some(CRATE_NODE_ID)) } else { None };
3567 match self.resolve_ident_in_lexical_scope(ident, ns, record_used_id, path_span) {
3568 // we found a locally-imported or available item/module
3569 Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
3570 // we found a local variable or type param
3571 Some(LexicalScopeBinding::Def(def))
3572 if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) => {
3573 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3577 _ => Err(if record_used { Determined } else { Undetermined }),
3584 second_binding = Some(binding);
3586 let def = binding.def();
3587 let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(def);
3588 if let Some(next_module) = binding.module() {
3589 module = Some(ModuleOrUniformRoot::Module(next_module));
3590 } else if def == Def::ToolMod && i + 1 != path.len() {
3591 let def = Def::NonMacroAttr(NonMacroAttrKind::Tool);
3592 return PathResult::NonModule(PathResolution::new(def));
3593 } else if def == Def::Err {
3594 return PathResult::NonModule(err_path_resolution());
3595 } else if opt_ns.is_some() && (is_last || maybe_assoc) {
3596 self.lint_if_path_starts_with_module(
3602 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3603 def, path.len() - i - 1
3606 return PathResult::Failed(ident.span,
3607 format!("Not a module `{}`", ident),
3611 Err(Undetermined) => return PathResult::Indeterminate,
3612 Err(Determined) => {
3613 if let Some(ModuleOrUniformRoot::Module(module)) = module {
3614 if opt_ns.is_some() && !module.is_normal() {
3615 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3616 module.def().unwrap(), path.len() - i
3620 let module_def = match module {
3621 Some(ModuleOrUniformRoot::Module(module)) => module.def(),
3624 let msg = if module_def == self.graph_root.def() {
3625 let is_mod = |def| match def { Def::Mod(..) => true, _ => false };
3626 let mut candidates =
3627 self.lookup_import_candidates(name, TypeNS, is_mod);
3628 candidates.sort_by_cached_key(|c| {
3629 (c.path.segments.len(), c.path.to_string())
3631 if let Some(candidate) = candidates.get(0) {
3632 format!("Did you mean `{}`?", candidate.path)
3634 format!("Maybe a missing `extern crate {};`?", ident)
3637 format!("Use of undeclared type or module `{}`", ident)
3639 format!("Could not find `{}` in `{}`", ident, path[i - 1])
3641 return PathResult::Failed(ident.span, msg, is_last);
3646 self.lint_if_path_starts_with_module(crate_lint, path, path_span, second_binding);
3648 PathResult::Module(module.unwrap_or_else(|| {
3649 span_bug!(path_span, "resolve_path: empty(?) path {:?} has no module", path);
3654 fn lint_if_path_starts_with_module(
3656 crate_lint: CrateLint,
3659 second_binding: Option<&NameBinding>,
3661 // In the 2018 edition this lint is a hard error, so nothing to do
3662 if self.session.rust_2018() {
3666 // In the 2015 edition there's no use in emitting lints unless the
3667 // crate's already enabled the feature that we're going to suggest
3668 if !self.session.features_untracked().crate_in_paths {
3672 let (diag_id, diag_span) = match crate_lint {
3673 CrateLint::No => return,
3674 CrateLint::SimplePath(id) => (id, path_span),
3675 CrateLint::UsePath { root_id, root_span } => (root_id, root_span),
3676 CrateLint::QPathTrait { qpath_id, qpath_span } => (qpath_id, qpath_span),
3679 let first_name = match path.get(0) {
3680 Some(ident) => ident.name,
3684 // We're only interested in `use` paths which should start with
3685 // `{{root}}` or `extern` currently.
3686 if first_name != keywords::Extern.name() && first_name != keywords::CrateRoot.name() {
3691 // If this import looks like `crate::...` it's already good
3692 Some(ident) if ident.name == keywords::Crate.name() => return,
3693 // Otherwise go below to see if it's an extern crate
3695 // If the path has length one (and it's `CrateRoot` most likely)
3696 // then we don't know whether we're gonna be importing a crate or an
3697 // item in our crate. Defer this lint to elsewhere
3701 // If the first element of our path was actually resolved to an
3702 // `ExternCrate` (also used for `crate::...`) then no need to issue a
3703 // warning, this looks all good!
3704 if let Some(binding) = second_binding {
3705 if let NameBindingKind::Import { directive: d, .. } = binding.kind {
3706 // Careful: we still want to rewrite paths from
3707 // renamed extern crates.
3708 if let ImportDirectiveSubclass::ExternCrate(None) = d.subclass {
3714 let diag = lint::builtin::BuiltinLintDiagnostics
3715 ::AbsPathWithModule(diag_span);
3716 self.session.buffer_lint_with_diagnostic(
3717 lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
3719 "absolute paths must start with `self`, `super`, \
3720 `crate`, or an external crate name in the 2018 edition",
3724 // Resolve a local definition, potentially adjusting for closures.
3725 fn adjust_local_def(&mut self,
3730 span: Span) -> Def {
3731 let ribs = &self.ribs[ns][rib_index + 1..];
3733 // An invalid forward use of a type parameter from a previous default.
3734 if let ForwardTyParamBanRibKind = self.ribs[ns][rib_index].kind {
3736 resolve_error(self, span, ResolutionError::ForwardDeclaredTyParam);
3738 assert_eq!(def, Def::Err);
3744 span_bug!(span, "unexpected {:?} in bindings", def)
3746 Def::Local(node_id) => {
3749 NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) |
3750 ForwardTyParamBanRibKind => {
3751 // Nothing to do. Continue.
3753 ClosureRibKind(function_id) => {
3756 let seen = self.freevars_seen
3759 if let Some(&index) = seen.get(&node_id) {
3760 def = Def::Upvar(node_id, index, function_id);
3763 let vec = self.freevars
3766 let depth = vec.len();
3767 def = Def::Upvar(node_id, depth, function_id);
3774 seen.insert(node_id, depth);
3777 ItemRibKind | TraitOrImplItemRibKind => {
3778 // This was an attempt to access an upvar inside a
3779 // named function item. This is not allowed, so we
3782 resolve_error(self, span,
3783 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
3787 ConstantItemRibKind => {
3788 // Still doesn't deal with upvars
3790 resolve_error(self, span,
3791 ResolutionError::AttemptToUseNonConstantValueInConstant);
3798 Def::TyParam(..) | Def::SelfTy(..) => {
3801 NormalRibKind | TraitOrImplItemRibKind | ClosureRibKind(..) |
3802 ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind |
3803 ConstantItemRibKind => {
3804 // Nothing to do. Continue.
3807 // This was an attempt to use a type parameter outside
3810 resolve_error(self, span,
3811 ResolutionError::TypeParametersFromOuterFunction(def));
3823 fn lookup_assoc_candidate<FilterFn>(&mut self,
3826 filter_fn: FilterFn)
3827 -> Option<AssocSuggestion>
3828 where FilterFn: Fn(Def) -> bool
3830 fn extract_node_id(t: &Ty) -> Option<NodeId> {
3832 TyKind::Path(None, _) => Some(t.id),
3833 TyKind::Rptr(_, ref mut_ty) => extract_node_id(&mut_ty.ty),
3834 // This doesn't handle the remaining `Ty` variants as they are not
3835 // that commonly the self_type, it might be interesting to provide
3836 // support for those in future.
3841 // Fields are generally expected in the same contexts as locals.
3842 if filter_fn(Def::Local(ast::DUMMY_NODE_ID)) {
3843 if let Some(node_id) = self.current_self_type.as_ref().and_then(extract_node_id) {
3844 // Look for a field with the same name in the current self_type.
3845 if let Some(resolution) = self.def_map.get(&node_id) {
3846 match resolution.base_def() {
3847 Def::Struct(did) | Def::Union(did)
3848 if resolution.unresolved_segments() == 0 => {
3849 if let Some(field_names) = self.field_names.get(&did) {
3850 if field_names.iter().any(|&field_name| ident.name == field_name) {
3851 return Some(AssocSuggestion::Field);
3861 // Look for associated items in the current trait.
3862 if let Some((module, _)) = self.current_trait_ref {
3863 if let Ok(binding) = self.resolve_ident_in_module(
3864 ModuleOrUniformRoot::Module(module),
3870 let def = binding.def();
3872 return Some(if self.has_self.contains(&def.def_id()) {
3873 AssocSuggestion::MethodWithSelf
3875 AssocSuggestion::AssocItem
3884 fn lookup_typo_candidate<FilterFn>(&mut self,
3887 filter_fn: FilterFn,
3890 where FilterFn: Fn(Def) -> bool
3892 let add_module_candidates = |module: Module, names: &mut Vec<Name>| {
3893 for (&(ident, _), resolution) in module.resolutions.borrow().iter() {
3894 if let Some(binding) = resolution.borrow().binding {
3895 if filter_fn(binding.def()) {
3896 names.push(ident.name);
3902 let mut names = Vec::new();
3903 if path.len() == 1 {
3904 // Search in lexical scope.
3905 // Walk backwards up the ribs in scope and collect candidates.
3906 for rib in self.ribs[ns].iter().rev() {
3907 // Locals and type parameters
3908 for (ident, def) in &rib.bindings {
3909 if filter_fn(*def) {
3910 names.push(ident.name);
3914 if let ModuleRibKind(module) = rib.kind {
3915 // Items from this module
3916 add_module_candidates(module, &mut names);
3918 if let ModuleKind::Block(..) = module.kind {
3919 // We can see through blocks
3921 // Items from the prelude
3922 if !module.no_implicit_prelude {
3923 names.extend(self.extern_prelude.iter().cloned());
3924 if let Some(prelude) = self.prelude {
3925 add_module_candidates(prelude, &mut names);
3932 // Add primitive types to the mix
3933 if filter_fn(Def::PrimTy(Bool)) {
3935 self.primitive_type_table.primitive_types.iter().map(|(name, _)| name)
3939 // Search in module.
3940 let mod_path = &path[..path.len() - 1];
3941 if let PathResult::Module(module) = self.resolve_path(None, mod_path, Some(TypeNS),
3942 false, span, CrateLint::No) {
3943 if let ModuleOrUniformRoot::Module(module) = module {
3944 add_module_candidates(module, &mut names);
3949 let name = path[path.len() - 1].name;
3950 // Make sure error reporting is deterministic.
3951 names.sort_by_cached_key(|name| name.as_str());
3952 match find_best_match_for_name(names.iter(), &name.as_str(), None) {
3953 Some(found) if found != name => Some(found),
3958 fn with_resolved_label<F>(&mut self, label: Option<Label>, id: NodeId, f: F)
3959 where F: FnOnce(&mut Resolver)
3961 if let Some(label) = label {
3962 self.unused_labels.insert(id, label.ident.span);
3963 let def = Def::Label(id);
3964 self.with_label_rib(|this| {
3965 let ident = label.ident.modern_and_legacy();
3966 this.label_ribs.last_mut().unwrap().bindings.insert(ident, def);
3974 fn resolve_labeled_block(&mut self, label: Option<Label>, id: NodeId, block: &Block) {
3975 self.with_resolved_label(label, id, |this| this.visit_block(block));
3978 fn resolve_expr(&mut self, expr: &Expr, parent: Option<&Expr>) {
3979 // First, record candidate traits for this expression if it could
3980 // result in the invocation of a method call.
3982 self.record_candidate_traits_for_expr_if_necessary(expr);
3984 // Next, resolve the node.
3986 ExprKind::Path(ref qself, ref path) => {
3987 self.smart_resolve_path(expr.id, qself.as_ref(), path, PathSource::Expr(parent));
3988 visit::walk_expr(self, expr);
3991 ExprKind::Struct(ref path, ..) => {
3992 self.smart_resolve_path(expr.id, None, path, PathSource::Struct);
3993 visit::walk_expr(self, expr);
3996 ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => {
3997 let def = self.search_label(label.ident, |rib, ident| {
3998 rib.bindings.get(&ident.modern_and_legacy()).cloned()
4002 // Search again for close matches...
4003 // Picks the first label that is "close enough", which is not necessarily
4004 // the closest match
4005 let close_match = self.search_label(label.ident, |rib, ident| {
4006 let names = rib.bindings.iter().map(|(id, _)| &id.name);
4007 find_best_match_for_name(names, &*ident.as_str(), None)
4009 self.record_def(expr.id, err_path_resolution());
4012 ResolutionError::UndeclaredLabel(&label.ident.as_str(),
4015 Some(Def::Label(id)) => {
4016 // Since this def is a label, it is never read.
4017 self.record_def(expr.id, PathResolution::new(Def::Label(id)));
4018 self.unused_labels.remove(&id);
4021 span_bug!(expr.span, "label wasn't mapped to a label def!");
4025 // visit `break` argument if any
4026 visit::walk_expr(self, expr);
4029 ExprKind::IfLet(ref pats, ref subexpression, ref if_block, ref optional_else) => {
4030 self.visit_expr(subexpression);
4032 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
4033 let mut bindings_list = FxHashMap();
4035 self.resolve_pattern(pat, PatternSource::IfLet, &mut bindings_list);
4037 // This has to happen *after* we determine which pat_idents are variants
4038 self.check_consistent_bindings(pats);
4039 self.visit_block(if_block);
4040 self.ribs[ValueNS].pop();
4042 optional_else.as_ref().map(|expr| self.visit_expr(expr));
4045 ExprKind::Loop(ref block, label) => self.resolve_labeled_block(label, expr.id, &block),
4047 ExprKind::While(ref subexpression, ref block, label) => {
4048 self.with_resolved_label(label, expr.id, |this| {
4049 this.visit_expr(subexpression);
4050 this.visit_block(block);
4054 ExprKind::WhileLet(ref pats, ref subexpression, ref block, label) => {
4055 self.with_resolved_label(label, expr.id, |this| {
4056 this.visit_expr(subexpression);
4057 this.ribs[ValueNS].push(Rib::new(NormalRibKind));
4058 let mut bindings_list = FxHashMap();
4060 this.resolve_pattern(pat, PatternSource::WhileLet, &mut bindings_list);
4062 // This has to happen *after* we determine which pat_idents are variants
4063 this.check_consistent_bindings(pats);
4064 this.visit_block(block);
4065 this.ribs[ValueNS].pop();
4069 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, label) => {
4070 self.visit_expr(subexpression);
4071 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
4072 self.resolve_pattern(pattern, PatternSource::For, &mut FxHashMap());
4074 self.resolve_labeled_block(label, expr.id, block);
4076 self.ribs[ValueNS].pop();
4079 ExprKind::Block(ref block, label) => self.resolve_labeled_block(label, block.id, block),
4081 // Equivalent to `visit::walk_expr` + passing some context to children.
4082 ExprKind::Field(ref subexpression, _) => {
4083 self.resolve_expr(subexpression, Some(expr));
4085 ExprKind::MethodCall(ref segment, ref arguments) => {
4086 let mut arguments = arguments.iter();
4087 self.resolve_expr(arguments.next().unwrap(), Some(expr));
4088 for argument in arguments {
4089 self.resolve_expr(argument, None);
4091 self.visit_path_segment(expr.span, segment);
4094 ExprKind::Call(ref callee, ref arguments) => {
4095 self.resolve_expr(callee, Some(expr));
4096 for argument in arguments {
4097 self.resolve_expr(argument, None);
4100 ExprKind::Type(ref type_expr, _) => {
4101 self.current_type_ascription.push(type_expr.span);
4102 visit::walk_expr(self, expr);
4103 self.current_type_ascription.pop();
4105 // Resolve the body of async exprs inside the async closure to which they desugar
4106 ExprKind::Async(_, async_closure_id, ref block) => {
4107 let rib_kind = ClosureRibKind(async_closure_id);
4108 self.ribs[ValueNS].push(Rib::new(rib_kind));
4109 self.label_ribs.push(Rib::new(rib_kind));
4110 self.visit_block(&block);
4111 self.label_ribs.pop();
4112 self.ribs[ValueNS].pop();
4114 // `async |x| ...` gets desugared to `|x| future_from_generator(|| ...)`, so we need to
4115 // resolve the arguments within the proper scopes so that usages of them inside the
4116 // closure are detected as upvars rather than normal closure arg usages.
4118 _, IsAsync::Async { closure_id: inner_closure_id, .. }, _,
4119 ref fn_decl, ref body, _span,
4121 let rib_kind = ClosureRibKind(expr.id);
4122 self.ribs[ValueNS].push(Rib::new(rib_kind));
4123 self.label_ribs.push(Rib::new(rib_kind));
4124 // Resolve arguments:
4125 let mut bindings_list = FxHashMap();
4126 for argument in &fn_decl.inputs {
4127 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
4128 self.visit_ty(&argument.ty);
4130 // No need to resolve return type-- the outer closure return type is
4131 // FunctionRetTy::Default
4133 // Now resolve the inner closure
4135 let rib_kind = ClosureRibKind(inner_closure_id);
4136 self.ribs[ValueNS].push(Rib::new(rib_kind));
4137 self.label_ribs.push(Rib::new(rib_kind));
4138 // No need to resolve arguments: the inner closure has none.
4139 // Resolve the return type:
4140 visit::walk_fn_ret_ty(self, &fn_decl.output);
4142 self.visit_expr(body);
4143 self.label_ribs.pop();
4144 self.ribs[ValueNS].pop();
4146 self.label_ribs.pop();
4147 self.ribs[ValueNS].pop();
4150 visit::walk_expr(self, expr);
4155 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
4157 ExprKind::Field(_, ident) => {
4158 // FIXME(#6890): Even though you can't treat a method like a
4159 // field, we need to add any trait methods we find that match
4160 // the field name so that we can do some nice error reporting
4161 // later on in typeck.
4162 let traits = self.get_traits_containing_item(ident, ValueNS);
4163 self.trait_map.insert(expr.id, traits);
4165 ExprKind::MethodCall(ref segment, ..) => {
4166 debug!("(recording candidate traits for expr) recording traits for {}",
4168 let traits = self.get_traits_containing_item(segment.ident, ValueNS);
4169 self.trait_map.insert(expr.id, traits);
4177 fn get_traits_containing_item(&mut self, mut ident: Ident, ns: Namespace)
4178 -> Vec<TraitCandidate> {
4179 debug!("(getting traits containing item) looking for '{}'", ident.name);
4181 let mut found_traits = Vec::new();
4182 // Look for the current trait.
4183 if let Some((module, _)) = self.current_trait_ref {
4184 if self.resolve_ident_in_module(
4185 ModuleOrUniformRoot::Module(module),
4191 let def_id = module.def_id().unwrap();
4192 found_traits.push(TraitCandidate { def_id: def_id, import_id: None });
4196 ident.span = ident.span.modern();
4197 let mut search_module = self.current_module;
4199 self.get_traits_in_module_containing_item(ident, ns, search_module, &mut found_traits);
4200 search_module = unwrap_or!(
4201 self.hygienic_lexical_parent(search_module, &mut ident.span), break
4205 if let Some(prelude) = self.prelude {
4206 if !search_module.no_implicit_prelude {
4207 self.get_traits_in_module_containing_item(ident, ns, prelude, &mut found_traits);
4214 fn get_traits_in_module_containing_item(&mut self,
4218 found_traits: &mut Vec<TraitCandidate>) {
4219 assert!(ns == TypeNS || ns == ValueNS);
4220 let mut traits = module.traits.borrow_mut();
4221 if traits.is_none() {
4222 let mut collected_traits = Vec::new();
4223 module.for_each_child(|name, ns, binding| {
4224 if ns != TypeNS { return }
4225 if let Def::Trait(_) = binding.def() {
4226 collected_traits.push((name, binding));
4229 *traits = Some(collected_traits.into_boxed_slice());
4232 for &(trait_name, binding) in traits.as_ref().unwrap().iter() {
4233 let module = binding.module().unwrap();
4234 let mut ident = ident;
4235 if ident.span.glob_adjust(module.expansion, binding.span.ctxt().modern()).is_none() {
4238 if self.resolve_ident_in_module_unadjusted(
4239 ModuleOrUniformRoot::Module(module),
4246 let import_id = match binding.kind {
4247 NameBindingKind::Import { directive, .. } => {
4248 self.maybe_unused_trait_imports.insert(directive.id);
4249 self.add_to_glob_map(directive.id, trait_name);
4254 let trait_def_id = module.def_id().unwrap();
4255 found_traits.push(TraitCandidate { def_id: trait_def_id, import_id: import_id });
4260 fn lookup_import_candidates_from_module<FilterFn>(&mut self,
4262 namespace: Namespace,
4263 start_module: &'a ModuleData<'a>,
4265 filter_fn: FilterFn)
4266 -> Vec<ImportSuggestion>
4267 where FilterFn: Fn(Def) -> bool
4269 let mut candidates = Vec::new();
4270 let mut worklist = Vec::new();
4271 let mut seen_modules = FxHashSet();
4272 let not_local_module = crate_name != keywords::Crate.ident();
4273 worklist.push((start_module, Vec::<ast::PathSegment>::new(), not_local_module));
4275 while let Some((in_module,
4277 in_module_is_extern)) = worklist.pop() {
4278 self.populate_module_if_necessary(in_module);
4280 // We have to visit module children in deterministic order to avoid
4281 // instabilities in reported imports (#43552).
4282 in_module.for_each_child_stable(|ident, ns, name_binding| {
4283 // avoid imports entirely
4284 if name_binding.is_import() && !name_binding.is_extern_crate() { return; }
4285 // avoid non-importable candidates as well
4286 if !name_binding.is_importable() { return; }
4288 // collect results based on the filter function
4289 if ident.name == lookup_name && ns == namespace {
4290 if filter_fn(name_binding.def()) {
4292 let mut segms = path_segments.clone();
4293 if self.session.rust_2018() {
4294 // crate-local absolute paths start with `crate::` in edition 2018
4295 // FIXME: may also be stabilized for Rust 2015 (Issues #45477, #44660)
4297 0, ast::PathSegment::from_ident(crate_name)
4301 segms.push(ast::PathSegment::from_ident(ident));
4303 span: name_binding.span,
4306 // the entity is accessible in the following cases:
4307 // 1. if it's defined in the same crate, it's always
4308 // accessible (since private entities can be made public)
4309 // 2. if it's defined in another crate, it's accessible
4310 // only if both the module is public and the entity is
4311 // declared as public (due to pruning, we don't explore
4312 // outside crate private modules => no need to check this)
4313 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
4314 candidates.push(ImportSuggestion { path: path });
4319 // collect submodules to explore
4320 if let Some(module) = name_binding.module() {
4322 let mut path_segments = path_segments.clone();
4323 path_segments.push(ast::PathSegment::from_ident(ident));
4325 let is_extern_crate_that_also_appears_in_prelude =
4326 name_binding.is_extern_crate() &&
4327 self.session.rust_2018();
4329 let is_visible_to_user =
4330 !in_module_is_extern || name_binding.vis == ty::Visibility::Public;
4332 if !is_extern_crate_that_also_appears_in_prelude && is_visible_to_user {
4333 // add the module to the lookup
4334 let is_extern = in_module_is_extern || name_binding.is_extern_crate();
4335 if seen_modules.insert(module.def_id().unwrap()) {
4336 worklist.push((module, path_segments, is_extern));
4346 /// When name resolution fails, this method can be used to look up candidate
4347 /// entities with the expected name. It allows filtering them using the
4348 /// supplied predicate (which should be used to only accept the types of
4349 /// definitions expected e.g. traits). The lookup spans across all crates.
4351 /// NOTE: The method does not look into imports, but this is not a problem,
4352 /// since we report the definitions (thus, the de-aliased imports).
4353 fn lookup_import_candidates<FilterFn>(&mut self,
4355 namespace: Namespace,
4356 filter_fn: FilterFn)
4357 -> Vec<ImportSuggestion>
4358 where FilterFn: Fn(Def) -> bool
4360 let mut suggestions = vec![];
4363 self.lookup_import_candidates_from_module(
4364 lookup_name, namespace, self.graph_root, keywords::Crate.ident(), &filter_fn
4368 if self.session.features_untracked().extern_prelude {
4369 let extern_prelude_names = self.extern_prelude.clone();
4370 for &krate_name in extern_prelude_names.iter() {
4371 let krate_ident = Ident::with_empty_ctxt(krate_name);
4372 let external_prelude_module = self.load_extern_prelude_crate_if_needed(krate_ident);
4375 self.lookup_import_candidates_from_module(
4376 lookup_name, namespace, external_prelude_module, krate_ident, &filter_fn
4385 fn find_module(&mut self,
4387 -> Option<(Module<'a>, ImportSuggestion)>
4389 let mut result = None;
4390 let mut worklist = Vec::new();
4391 let mut seen_modules = FxHashSet();
4392 worklist.push((self.graph_root, Vec::new()));
4394 while let Some((in_module, path_segments)) = worklist.pop() {
4395 // abort if the module is already found
4396 if result.is_some() { break; }
4398 self.populate_module_if_necessary(in_module);
4400 in_module.for_each_child_stable(|ident, _, name_binding| {
4401 // abort if the module is already found or if name_binding is private external
4402 if result.is_some() || !name_binding.vis.is_visible_locally() {
4405 if let Some(module) = name_binding.module() {
4407 let mut path_segments = path_segments.clone();
4408 path_segments.push(ast::PathSegment::from_ident(ident));
4409 if module.def() == Some(module_def) {
4411 span: name_binding.span,
4412 segments: path_segments,
4414 result = Some((module, ImportSuggestion { path: path }));
4416 // add the module to the lookup
4417 if seen_modules.insert(module.def_id().unwrap()) {
4418 worklist.push((module, path_segments));
4428 fn collect_enum_variants(&mut self, enum_def: Def) -> Option<Vec<Path>> {
4429 if let Def::Enum(..) = enum_def {} else {
4430 panic!("Non-enum def passed to collect_enum_variants: {:?}", enum_def)
4433 self.find_module(enum_def).map(|(enum_module, enum_import_suggestion)| {
4434 self.populate_module_if_necessary(enum_module);
4436 let mut variants = Vec::new();
4437 enum_module.for_each_child_stable(|ident, _, name_binding| {
4438 if let Def::Variant(..) = name_binding.def() {
4439 let mut segms = enum_import_suggestion.path.segments.clone();
4440 segms.push(ast::PathSegment::from_ident(ident));
4441 variants.push(Path {
4442 span: name_binding.span,
4451 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
4452 debug!("(recording def) recording {:?} for {}", resolution, node_id);
4453 if let Some(prev_res) = self.def_map.insert(node_id, resolution) {
4454 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
4458 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
4460 ast::VisibilityKind::Public => ty::Visibility::Public,
4461 ast::VisibilityKind::Crate(..) => {
4462 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
4464 ast::VisibilityKind::Inherited => {
4465 ty::Visibility::Restricted(self.current_module.normal_ancestor_id)
4467 ast::VisibilityKind::Restricted { ref path, id, .. } => {
4468 // Visibilities are resolved as global by default, add starting root segment.
4469 let segments = path.make_root().iter().chain(path.segments.iter())
4470 .map(|seg| seg.ident)
4471 .collect::<Vec<_>>();
4472 let def = self.smart_resolve_path_fragment(
4477 PathSource::Visibility,
4478 CrateLint::SimplePath(id),
4480 if def == Def::Err {
4481 ty::Visibility::Public
4483 let vis = ty::Visibility::Restricted(def.def_id());
4484 if self.is_accessible(vis) {
4487 self.session.span_err(path.span, "visibilities can only be restricted \
4488 to ancestor modules");
4489 ty::Visibility::Public
4496 fn is_accessible(&self, vis: ty::Visibility) -> bool {
4497 vis.is_accessible_from(self.current_module.normal_ancestor_id, self)
4500 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
4501 vis.is_accessible_from(module.normal_ancestor_id, self)
4504 fn report_ambiguity_error(
4505 &self, name: Name, span: Span, _lexical: bool,
4506 def1: Def, is_import1: bool, is_glob1: bool, from_expansion1: bool, span1: Span,
4507 def2: Def, is_import2: bool, _is_glob2: bool, _from_expansion2: bool, span2: Span,
4509 let participle = |is_import: bool| if is_import { "imported" } else { "defined" };
4510 let msg1 = format!("`{}` could refer to the name {} here", name, participle(is_import1));
4512 format!("`{}` could also refer to the name {} here", name, participle(is_import2));
4513 let note = if from_expansion1 {
4514 Some(if let Def::Macro(..) = def1 {
4515 format!("macro-expanded {} do not shadow",
4516 if is_import1 { "macro imports" } else { "macros" })
4518 format!("macro-expanded {} do not shadow when used in a macro invocation path",
4519 if is_import1 { "imports" } else { "items" })
4521 } else if is_glob1 {
4522 Some(format!("consider adding an explicit import of `{}` to disambiguate", name))
4527 let mut err = struct_span_err!(self.session, span, E0659, "`{}` is ambiguous", name);
4528 err.span_note(span1, &msg1);
4530 Def::Macro(..) if span2.is_dummy() =>
4531 err.note(&format!("`{}` is also a builtin macro", name)),
4532 _ => err.span_note(span2, &msg2),
4534 if let Some(note) = note {
4540 fn report_errors(&mut self, krate: &Crate) {
4541 self.report_shadowing_errors();
4542 self.report_with_use_injections(krate);
4543 self.report_proc_macro_import(krate);
4544 let mut reported_spans = FxHashSet();
4546 for &(span_use, span_def) in &self.macro_expanded_macro_export_errors {
4547 let msg = "macro-expanded `macro_export` macros from the current crate \
4548 cannot be referred to by absolute paths";
4549 self.session.buffer_lint_with_diagnostic(
4550 lint::builtin::MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS,
4551 CRATE_NODE_ID, span_use, msg,
4552 lint::builtin::BuiltinLintDiagnostics::
4553 MacroExpandedMacroExportsAccessedByAbsolutePaths(span_def),
4557 for &AmbiguityError { span, name, b1, b2, lexical } in &self.ambiguity_errors {
4558 if reported_spans.insert(span) {
4559 self.report_ambiguity_error(
4560 name, span, lexical,
4561 b1.def(), b1.is_import(), b1.is_glob_import(),
4562 b1.expansion != Mark::root(), b1.span,
4563 b2.def(), b2.is_import(), b2.is_glob_import(),
4564 b2.expansion != Mark::root(), b2.span,
4569 for &PrivacyError(span, name, binding) in &self.privacy_errors {
4570 if !reported_spans.insert(span) { continue }
4571 span_err!(self.session, span, E0603, "{} `{}` is private", binding.descr(), name);
4575 fn report_with_use_injections(&mut self, krate: &Crate) {
4576 for UseError { mut err, candidates, node_id, better } in self.use_injections.drain(..) {
4577 let (span, found_use) = UsePlacementFinder::check(krate, node_id);
4578 if !candidates.is_empty() {
4579 show_candidates(&mut err, span, &candidates, better, found_use);
4585 fn report_shadowing_errors(&mut self) {
4586 let mut reported_errors = FxHashSet();
4587 for binding in replace(&mut self.disallowed_shadowing, Vec::new()) {
4588 if self.resolve_legacy_scope(&binding.parent, binding.ident, false).is_some() &&
4589 reported_errors.insert((binding.ident, binding.span)) {
4590 let msg = format!("`{}` is already in scope", binding.ident);
4591 self.session.struct_span_err(binding.span, &msg)
4592 .note("macro-expanded `macro_rules!`s may not shadow \
4593 existing macros (see RFC 1560)")
4599 fn report_conflict<'b>(&mut self,
4603 new_binding: &NameBinding<'b>,
4604 old_binding: &NameBinding<'b>) {
4605 // Error on the second of two conflicting names
4606 if old_binding.span.lo() > new_binding.span.lo() {
4607 return self.report_conflict(parent, ident, ns, old_binding, new_binding);
4610 let container = match parent.kind {
4611 ModuleKind::Def(Def::Mod(_), _) => "module",
4612 ModuleKind::Def(Def::Trait(_), _) => "trait",
4613 ModuleKind::Block(..) => "block",
4617 let old_noun = match old_binding.is_import() {
4619 false => "definition",
4622 let new_participle = match new_binding.is_import() {
4627 let (name, span) = (ident.name, self.session.source_map().def_span(new_binding.span));
4629 if let Some(s) = self.name_already_seen.get(&name) {
4635 let old_kind = match (ns, old_binding.module()) {
4636 (ValueNS, _) => "value",
4637 (MacroNS, _) => "macro",
4638 (TypeNS, _) if old_binding.is_extern_crate() => "extern crate",
4639 (TypeNS, Some(module)) if module.is_normal() => "module",
4640 (TypeNS, Some(module)) if module.is_trait() => "trait",
4641 (TypeNS, _) => "type",
4644 let msg = format!("the name `{}` is defined multiple times", name);
4646 let mut err = match (old_binding.is_extern_crate(), new_binding.is_extern_crate()) {
4647 (true, true) => struct_span_err!(self.session, span, E0259, "{}", msg),
4648 (true, _) | (_, true) => match new_binding.is_import() && old_binding.is_import() {
4649 true => struct_span_err!(self.session, span, E0254, "{}", msg),
4650 false => struct_span_err!(self.session, span, E0260, "{}", msg),
4652 _ => match (old_binding.is_import(), new_binding.is_import()) {
4653 (false, false) => struct_span_err!(self.session, span, E0428, "{}", msg),
4654 (true, true) => struct_span_err!(self.session, span, E0252, "{}", msg),
4655 _ => struct_span_err!(self.session, span, E0255, "{}", msg),
4659 err.note(&format!("`{}` must be defined only once in the {} namespace of this {}",
4664 err.span_label(span, format!("`{}` re{} here", name, new_participle));
4665 if !old_binding.span.is_dummy() {
4666 err.span_label(self.session.source_map().def_span(old_binding.span),
4667 format!("previous {} of the {} `{}` here", old_noun, old_kind, name));
4670 // See https://github.com/rust-lang/rust/issues/32354
4671 if old_binding.is_import() || new_binding.is_import() {
4672 let binding = if new_binding.is_import() && !new_binding.span.is_dummy() {
4678 let cm = self.session.source_map();
4679 let rename_msg = "You can use `as` to change the binding name of the import";
4681 if let (Ok(snippet), false) = (cm.span_to_snippet(binding.span),
4682 binding.is_renamed_extern_crate()) {
4683 let suggested_name = if name.as_str().chars().next().unwrap().is_uppercase() {
4684 format!("Other{}", name)
4686 format!("other_{}", name)
4689 err.span_suggestion_with_applicability(
4692 if snippet.ends_with(';') {
4693 format!("{} as {};", &snippet[..snippet.len() - 1], suggested_name)
4695 format!("{} as {}", snippet, suggested_name)
4697 Applicability::MachineApplicable,
4700 err.span_label(binding.span, rename_msg);
4705 self.name_already_seen.insert(name, span);
4709 fn is_self_type(path: &[Ident], namespace: Namespace) -> bool {
4710 namespace == TypeNS && path.len() == 1 && path[0].name == keywords::SelfType.name()
4713 fn is_self_value(path: &[Ident], namespace: Namespace) -> bool {
4714 namespace == ValueNS && path.len() == 1 && path[0].name == keywords::SelfValue.name()
4717 fn names_to_string(idents: &[Ident]) -> String {
4718 let mut result = String::new();
4719 for (i, ident) in idents.iter()
4720 .filter(|ident| ident.name != keywords::CrateRoot.name())
4723 result.push_str("::");
4725 result.push_str(&ident.as_str());
4730 fn path_names_to_string(path: &Path) -> String {
4731 names_to_string(&path.segments.iter()
4732 .map(|seg| seg.ident)
4733 .collect::<Vec<_>>())
4736 /// Get the path for an enum and the variant from an `ImportSuggestion` for an enum variant.
4737 fn import_candidate_to_paths(suggestion: &ImportSuggestion) -> (Span, String, String) {
4738 let variant_path = &suggestion.path;
4739 let variant_path_string = path_names_to_string(variant_path);
4741 let path_len = suggestion.path.segments.len();
4742 let enum_path = ast::Path {
4743 span: suggestion.path.span,
4744 segments: suggestion.path.segments[0..path_len - 1].to_vec(),
4746 let enum_path_string = path_names_to_string(&enum_path);
4748 (suggestion.path.span, variant_path_string, enum_path_string)
4752 /// When an entity with a given name is not available in scope, we search for
4753 /// entities with that name in all crates. This method allows outputting the
4754 /// results of this search in a programmer-friendly way
4755 fn show_candidates(err: &mut DiagnosticBuilder,
4756 // This is `None` if all placement locations are inside expansions
4758 candidates: &[ImportSuggestion],
4762 // we want consistent results across executions, but candidates are produced
4763 // by iterating through a hash map, so make sure they are ordered:
4764 let mut path_strings: Vec<_> =
4765 candidates.into_iter().map(|c| path_names_to_string(&c.path)).collect();
4766 path_strings.sort();
4768 let better = if better { "better " } else { "" };
4769 let msg_diff = match path_strings.len() {
4770 1 => " is found in another module, you can import it",
4771 _ => "s are found in other modules, you can import them",
4773 let msg = format!("possible {}candidate{} into scope", better, msg_diff);
4775 if let Some(span) = span {
4776 for candidate in &mut path_strings {
4777 // produce an additional newline to separate the new use statement
4778 // from the directly following item.
4779 let additional_newline = if found_use {
4784 *candidate = format!("use {};\n{}", candidate, additional_newline);
4787 err.span_suggestions(span, &msg, path_strings);
4791 for candidate in path_strings {
4793 msg.push_str(&candidate);
4798 /// A somewhat inefficient routine to obtain the name of a module.
4799 fn module_to_string(module: Module) -> Option<String> {
4800 let mut names = Vec::new();
4802 fn collect_mod(names: &mut Vec<Ident>, module: Module) {
4803 if let ModuleKind::Def(_, name) = module.kind {
4804 if let Some(parent) = module.parent {
4805 names.push(Ident::with_empty_ctxt(name));
4806 collect_mod(names, parent);
4809 // danger, shouldn't be ident?
4810 names.push(Ident::from_str("<opaque>"));
4811 collect_mod(names, module.parent.unwrap());
4814 collect_mod(&mut names, module);
4816 if names.is_empty() {
4819 Some(names_to_string(&names.into_iter()
4821 .collect::<Vec<_>>()))
4824 fn err_path_resolution() -> PathResolution {
4825 PathResolution::new(Def::Err)
4828 #[derive(PartialEq,Copy, Clone)]
4829 pub enum MakeGlobMap {
4834 #[derive(Copy, Clone, Debug)]
4836 /// Do not issue the lint
4839 /// This lint applies to some random path like `impl ::foo::Bar`
4840 /// or whatever. In this case, we can take the span of that path.
4843 /// This lint comes from a `use` statement. In this case, what we
4844 /// care about really is the *root* `use` statement; e.g., if we
4845 /// have nested things like `use a::{b, c}`, we care about the
4847 UsePath { root_id: NodeId, root_span: Span },
4849 /// This is the "trait item" from a fully qualified path. For example,
4850 /// we might be resolving `X::Y::Z` from a path like `<T as X::Y>::Z`.
4851 /// The `path_span` is the span of the to the trait itself (`X::Y`).
4852 QPathTrait { qpath_id: NodeId, qpath_span: Span },
4856 fn node_id(&self) -> Option<NodeId> {
4858 CrateLint::No => None,
4859 CrateLint::SimplePath(id) |
4860 CrateLint::UsePath { root_id: id, .. } |
4861 CrateLint::QPathTrait { qpath_id: id, .. } => Some(id),
4866 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }