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 #![feature(rustc_diagnostic_macros)]
17 #![feature(slice_sort_by_cached_key)]
23 extern crate syntax_pos;
24 extern crate rustc_errors as errors;
28 extern crate rustc_data_structures;
30 pub use rustc::hir::def::{Namespace, PerNS};
32 use self::TypeParameters::*;
35 use rustc::hir::map::{Definitions, DefCollector};
36 use rustc::hir::{self, PrimTy, TyBool, TyChar, TyFloat, TyInt, TyUint, TyStr};
37 use rustc::middle::cstore::{CrateStore, CrateLoader};
38 use rustc::session::Session;
40 use rustc::hir::def::*;
41 use rustc::hir::def::Namespace::*;
42 use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, DefId};
44 use rustc::hir::{Freevar, FreevarMap, TraitCandidate, TraitMap, GlobMap};
45 use rustc::util::nodemap::{NodeMap, NodeSet, FxHashMap, FxHashSet, DefIdMap};
47 use syntax::codemap::CodeMap;
48 use syntax::ext::hygiene::{Mark, Transparency, SyntaxContext};
49 use syntax::ast::{self, Name, NodeId, Ident, FloatTy, IntTy, UintTy};
50 use syntax::ext::base::SyntaxExtension;
51 use syntax::ext::base::Determinacy::{self, Determined, Undetermined};
52 use syntax::ext::base::MacroKind;
53 use syntax::symbol::{Symbol, keywords};
54 use syntax::util::lev_distance::find_best_match_for_name;
56 use syntax::visit::{self, FnKind, Visitor};
58 use syntax::ast::{Arm, IsAsync, BindingMode, Block, Crate, Expr, ExprKind};
59 use syntax::ast::{FnDecl, ForeignItem, ForeignItemKind, GenericParamKind, Generics};
60 use syntax::ast::{Item, ItemKind, ImplItem, ImplItemKind};
61 use syntax::ast::{Label, Local, Mutability, Pat, PatKind, Path};
62 use syntax::ast::{QSelf, TraitItemKind, TraitRef, Ty, TyKind};
63 use syntax::feature_gate::{feature_err, GateIssue};
66 use syntax_pos::{Span, DUMMY_SP, MultiSpan};
67 use errors::{DiagnosticBuilder, DiagnosticId};
69 use std::cell::{Cell, RefCell};
71 use std::collections::BTreeSet;
74 use std::mem::replace;
75 use rustc_data_structures::sync::Lrc;
77 use resolve_imports::{ImportDirective, ImportDirectiveSubclass, NameResolution, ImportResolver};
78 use macros::{InvocationData, LegacyBinding, LegacyScope, MacroBinding};
80 // NB: This module needs to be declared first so diagnostics are
81 // registered before they are used.
86 mod build_reduced_graph;
89 /// A free importable items suggested in case of resolution failure.
90 struct ImportSuggestion {
94 /// A field or associated item from self type suggested in case of resolution failure.
95 enum AssocSuggestion {
102 struct BindingError {
104 origin: BTreeSet<Span>,
105 target: BTreeSet<Span>,
108 impl PartialOrd for BindingError {
109 fn partial_cmp(&self, other: &BindingError) -> Option<cmp::Ordering> {
110 Some(self.cmp(other))
114 impl PartialEq for BindingError {
115 fn eq(&self, other: &BindingError) -> bool {
116 self.name == other.name
120 impl Ord for BindingError {
121 fn cmp(&self, other: &BindingError) -> cmp::Ordering {
122 self.name.cmp(&other.name)
126 enum ResolutionError<'a> {
127 /// error E0401: can't use type parameters from outer function
128 TypeParametersFromOuterFunction(Def),
129 /// error E0403: the name is already used for a type parameter in this type parameter list
130 NameAlreadyUsedInTypeParameterList(Name, &'a Span),
131 /// error E0407: method is not a member of trait
132 MethodNotMemberOfTrait(Name, &'a str),
133 /// error E0437: type is not a member of trait
134 TypeNotMemberOfTrait(Name, &'a str),
135 /// error E0438: const is not a member of trait
136 ConstNotMemberOfTrait(Name, &'a str),
137 /// error E0408: variable `{}` is not bound in all patterns
138 VariableNotBoundInPattern(&'a BindingError),
139 /// error E0409: variable `{}` is bound in inconsistent ways within the same match arm
140 VariableBoundWithDifferentMode(Name, Span),
141 /// error E0415: identifier is bound more than once in this parameter list
142 IdentifierBoundMoreThanOnceInParameterList(&'a str),
143 /// error E0416: identifier is bound more than once in the same pattern
144 IdentifierBoundMoreThanOnceInSamePattern(&'a str),
145 /// error E0426: use of undeclared label
146 UndeclaredLabel(&'a str, Option<Name>),
147 /// error E0429: `self` imports are only allowed within a { } list
148 SelfImportsOnlyAllowedWithin,
149 /// error E0430: `self` import can only appear once in the list
150 SelfImportCanOnlyAppearOnceInTheList,
151 /// error E0431: `self` import can only appear in an import list with a non-empty prefix
152 SelfImportOnlyInImportListWithNonEmptyPrefix,
153 /// error E0432: unresolved import
154 UnresolvedImport(Option<(Span, &'a str, &'a str)>),
155 /// error E0433: failed to resolve
156 FailedToResolve(&'a str),
157 /// error E0434: can't capture dynamic environment in a fn item
158 CannotCaptureDynamicEnvironmentInFnItem,
159 /// error E0435: attempt to use a non-constant value in a constant
160 AttemptToUseNonConstantValueInConstant,
161 /// error E0530: X bindings cannot shadow Ys
162 BindingShadowsSomethingUnacceptable(&'a str, Name, &'a NameBinding<'a>),
163 /// error E0128: type parameters with a default cannot use forward declared identifiers
164 ForwardDeclaredTyParam,
167 /// Combines an error with provided span and emits it
169 /// This takes the error provided, combines it with the span and any additional spans inside the
170 /// error and emits it.
171 fn resolve_error<'sess, 'a>(resolver: &'sess Resolver,
173 resolution_error: ResolutionError<'a>) {
174 resolve_struct_error(resolver, span, resolution_error).emit();
177 fn resolve_struct_error<'sess, 'a>(resolver: &'sess Resolver,
179 resolution_error: ResolutionError<'a>)
180 -> DiagnosticBuilder<'sess> {
181 match resolution_error {
182 ResolutionError::TypeParametersFromOuterFunction(outer_def) => {
183 let mut err = struct_span_err!(resolver.session,
186 "can't use type parameters from outer function");
187 err.span_label(span, "use of type variable from outer function");
189 let cm = resolver.session.codemap();
191 Def::SelfTy(_, maybe_impl_defid) => {
192 if let Some(impl_span) = maybe_impl_defid.map_or(None,
193 |def_id| resolver.definitions.opt_span(def_id)) {
194 err.span_label(reduce_impl_span_to_impl_keyword(cm, impl_span),
195 "`Self` type implicitely declared here, on the `impl`");
198 Def::TyParam(typaram_defid) => {
199 if let Some(typaram_span) = resolver.definitions.opt_span(typaram_defid) {
200 err.span_label(typaram_span, "type variable from outer function");
203 Def::Mod(..) | Def::Struct(..) | Def::Union(..) | Def::Enum(..) | Def::Variant(..) |
204 Def::Trait(..) | Def::TyAlias(..) | Def::TyForeign(..) | Def::TraitAlias(..) |
205 Def::AssociatedTy(..) | Def::PrimTy(..) | Def::Fn(..) | Def::Const(..) |
206 Def::Static(..) | Def::StructCtor(..) | Def::VariantCtor(..) | Def::Method(..) |
207 Def::AssociatedConst(..) | Def::Local(..) | Def::Upvar(..) | Def::Label(..) |
208 Def::Existential(..) |
209 Def::Macro(..) | Def::GlobalAsm(..) | Def::Err =>
210 bug!("TypeParametersFromOuterFunction should only be used with Def::SelfTy or \
214 // Try to retrieve the span of the function signature and generate a new message with
215 // a local type parameter
216 let sugg_msg = "try using a local type parameter instead";
217 if let Some((sugg_span, new_snippet)) = cm.generate_local_type_param_snippet(span) {
218 // Suggest the modification to the user
219 err.span_suggestion(sugg_span,
222 } else if let Some(sp) = cm.generate_fn_name_span(span) {
223 err.span_label(sp, "try adding a local type parameter in this method instead");
225 err.help("try using a local type parameter instead");
230 ResolutionError::NameAlreadyUsedInTypeParameterList(name, first_use_span) => {
231 let mut err = struct_span_err!(resolver.session,
234 "the name `{}` is already used for a type parameter \
235 in this type parameter list",
237 err.span_label(span, "already used");
238 err.span_label(first_use_span.clone(), format!("first use of `{}`", name));
241 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
242 let mut err = struct_span_err!(resolver.session,
245 "method `{}` is not a member of trait `{}`",
248 err.span_label(span, format!("not a member of trait `{}`", trait_));
251 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
252 let mut err = struct_span_err!(resolver.session,
255 "type `{}` is not a member of trait `{}`",
258 err.span_label(span, format!("not a member of trait `{}`", trait_));
261 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
262 let mut err = struct_span_err!(resolver.session,
265 "const `{}` is not a member of trait `{}`",
268 err.span_label(span, format!("not a member of trait `{}`", trait_));
271 ResolutionError::VariableNotBoundInPattern(binding_error) => {
272 let target_sp = binding_error.target.iter().map(|x| *x).collect::<Vec<_>>();
273 let msp = MultiSpan::from_spans(target_sp.clone());
274 let msg = format!("variable `{}` is not bound in all patterns", binding_error.name);
275 let mut err = resolver.session.struct_span_err_with_code(
278 DiagnosticId::Error("E0408".into()),
280 for sp in target_sp {
281 err.span_label(sp, format!("pattern doesn't bind `{}`", binding_error.name));
283 let origin_sp = binding_error.origin.iter().map(|x| *x).collect::<Vec<_>>();
284 for sp in origin_sp {
285 err.span_label(sp, "variable not in all patterns");
289 ResolutionError::VariableBoundWithDifferentMode(variable_name,
290 first_binding_span) => {
291 let mut err = struct_span_err!(resolver.session,
294 "variable `{}` is bound in inconsistent \
295 ways within the same match arm",
297 err.span_label(span, "bound in different ways");
298 err.span_label(first_binding_span, "first binding");
301 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
302 let mut err = struct_span_err!(resolver.session,
305 "identifier `{}` is bound more than once in this parameter list",
307 err.span_label(span, "used as parameter more than once");
310 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
311 let mut err = struct_span_err!(resolver.session,
314 "identifier `{}` is bound more than once in the same pattern",
316 err.span_label(span, "used in a pattern more than once");
319 ResolutionError::UndeclaredLabel(name, lev_candidate) => {
320 let mut err = struct_span_err!(resolver.session,
323 "use of undeclared label `{}`",
325 if let Some(lev_candidate) = lev_candidate {
326 err.span_label(span, format!("did you mean `{}`?", lev_candidate));
328 err.span_label(span, format!("undeclared label `{}`", name));
332 ResolutionError::SelfImportsOnlyAllowedWithin => {
333 struct_span_err!(resolver.session,
337 "`self` imports are only allowed within a { } list")
339 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
340 let mut err = struct_span_err!(resolver.session, span, E0430,
341 "`self` import can only appear once in an import list");
342 err.span_label(span, "can only appear once in an import list");
345 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
346 let mut err = struct_span_err!(resolver.session, span, E0431,
347 "`self` import can only appear in an import list with \
348 a non-empty prefix");
349 err.span_label(span, "can only appear in an import list with a non-empty prefix");
352 ResolutionError::UnresolvedImport(name) => {
353 let (span, msg) = match name {
354 Some((sp, n, _)) => (sp, format!("unresolved import `{}`", n)),
355 None => (span, "unresolved import".to_owned()),
357 let mut err = struct_span_err!(resolver.session, span, E0432, "{}", msg);
358 if let Some((_, _, p)) = name {
359 err.span_label(span, p);
363 ResolutionError::FailedToResolve(msg) => {
364 let mut err = struct_span_err!(resolver.session, span, E0433,
365 "failed to resolve. {}", msg);
366 err.span_label(span, msg);
369 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
370 let mut err = struct_span_err!(resolver.session,
374 "can't capture dynamic environment in a fn item");
375 err.help("use the `|| { ... }` closure form instead");
378 ResolutionError::AttemptToUseNonConstantValueInConstant => {
379 let mut err = struct_span_err!(resolver.session, span, E0435,
380 "attempt to use a non-constant value in a constant");
381 err.span_label(span, "non-constant value");
384 ResolutionError::BindingShadowsSomethingUnacceptable(what_binding, name, binding) => {
385 let shadows_what = PathResolution::new(binding.def()).kind_name();
386 let mut err = struct_span_err!(resolver.session,
389 "{}s cannot shadow {}s", what_binding, shadows_what);
390 err.span_label(span, format!("cannot be named the same as a {}", shadows_what));
391 let participle = if binding.is_import() { "imported" } else { "defined" };
392 let msg = format!("a {} `{}` is {} here", shadows_what, name, participle);
393 err.span_label(binding.span, msg);
396 ResolutionError::ForwardDeclaredTyParam => {
397 let mut err = struct_span_err!(resolver.session, span, E0128,
398 "type parameters with a default cannot use \
399 forward declared identifiers");
400 err.span_label(span, format!("defaulted type parameters cannot be forward declared"));
406 /// Adjust the impl span so that just the `impl` keyword is taken by removing
407 /// everything after `<` (`"impl<T> Iterator for A<T> {}" -> "impl"`) and
408 /// everything after the first whitespace (`"impl Iterator for A" -> "impl"`)
410 /// Attention: The method used is very fragile since it essentially duplicates the work of the
411 /// parser. If you need to use this function or something similar, please consider updating the
412 /// codemap functions and this function to something more robust.
413 fn reduce_impl_span_to_impl_keyword(cm: &CodeMap, impl_span: Span) -> Span {
414 let impl_span = cm.span_until_char(impl_span, '<');
415 let impl_span = cm.span_until_whitespace(impl_span);
419 #[derive(Copy, Clone, Debug)]
422 binding_mode: BindingMode,
425 /// Map from the name in a pattern to its binding mode.
426 type BindingMap = FxHashMap<Ident, BindingInfo>;
428 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
439 fn descr(self) -> &'static str {
441 PatternSource::Match => "match binding",
442 PatternSource::IfLet => "if let binding",
443 PatternSource::WhileLet => "while let binding",
444 PatternSource::Let => "let binding",
445 PatternSource::For => "for binding",
446 PatternSource::FnParam => "function parameter",
451 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
452 enum AliasPossibility {
457 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
458 enum PathSource<'a> {
459 // Type paths `Path`.
461 // Trait paths in bounds or impls.
462 Trait(AliasPossibility),
463 // Expression paths `path`, with optional parent context.
464 Expr(Option<&'a Expr>),
465 // Paths in path patterns `Path`.
467 // Paths in struct expressions and patterns `Path { .. }`.
469 // Paths in tuple struct patterns `Path(..)`.
471 // `m::A::B` in `<T as m::A>::B::C`.
472 TraitItem(Namespace),
473 // Path in `pub(path)`
475 // Path in `use a::b::{...};`
479 impl<'a> PathSource<'a> {
480 fn namespace(self) -> Namespace {
482 PathSource::Type | PathSource::Trait(_) | PathSource::Struct |
483 PathSource::Visibility | PathSource::ImportPrefix => TypeNS,
484 PathSource::Expr(..) | PathSource::Pat | PathSource::TupleStruct => ValueNS,
485 PathSource::TraitItem(ns) => ns,
489 fn global_by_default(self) -> bool {
491 PathSource::Visibility | PathSource::ImportPrefix => true,
492 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
493 PathSource::Struct | PathSource::TupleStruct |
494 PathSource::Trait(_) | PathSource::TraitItem(..) => false,
498 fn defer_to_typeck(self) -> bool {
500 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
501 PathSource::Struct | PathSource::TupleStruct => true,
502 PathSource::Trait(_) | PathSource::TraitItem(..) |
503 PathSource::Visibility | PathSource::ImportPrefix => false,
507 fn descr_expected(self) -> &'static str {
509 PathSource::Type => "type",
510 PathSource::Trait(_) => "trait",
511 PathSource::Pat => "unit struct/variant or constant",
512 PathSource::Struct => "struct, variant or union type",
513 PathSource::TupleStruct => "tuple struct/variant",
514 PathSource::Visibility => "module",
515 PathSource::ImportPrefix => "module or enum",
516 PathSource::TraitItem(ns) => match ns {
517 TypeNS => "associated type",
518 ValueNS => "method or associated constant",
519 MacroNS => bug!("associated macro"),
521 PathSource::Expr(parent) => match parent.map(|p| &p.node) {
522 // "function" here means "anything callable" rather than `Def::Fn`,
523 // this is not precise but usually more helpful than just "value".
524 Some(&ExprKind::Call(..)) => "function",
530 fn is_expected(self, def: Def) -> bool {
532 PathSource::Type => match def {
533 Def::Struct(..) | Def::Union(..) | Def::Enum(..) |
534 Def::Trait(..) | Def::TyAlias(..) | Def::AssociatedTy(..) |
535 Def::PrimTy(..) | Def::TyParam(..) | Def::SelfTy(..) |
536 Def::TyForeign(..) => true,
539 PathSource::Trait(AliasPossibility::No) => match def {
540 Def::Trait(..) => true,
543 PathSource::Trait(AliasPossibility::Maybe) => match def {
544 Def::Trait(..) => true,
545 Def::TraitAlias(..) => true,
548 PathSource::Expr(..) => match def {
549 Def::StructCtor(_, CtorKind::Const) | Def::StructCtor(_, CtorKind::Fn) |
550 Def::VariantCtor(_, CtorKind::Const) | Def::VariantCtor(_, CtorKind::Fn) |
551 Def::Const(..) | Def::Static(..) | Def::Local(..) | Def::Upvar(..) |
552 Def::Fn(..) | Def::Method(..) | Def::AssociatedConst(..) => true,
555 PathSource::Pat => match def {
556 Def::StructCtor(_, CtorKind::Const) |
557 Def::VariantCtor(_, CtorKind::Const) |
558 Def::Const(..) | Def::AssociatedConst(..) => true,
561 PathSource::TupleStruct => match def {
562 Def::StructCtor(_, CtorKind::Fn) | Def::VariantCtor(_, CtorKind::Fn) => true,
565 PathSource::Struct => match def {
566 Def::Struct(..) | Def::Union(..) | Def::Variant(..) |
567 Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) => true,
570 PathSource::TraitItem(ns) => match def {
571 Def::AssociatedConst(..) | Def::Method(..) if ns == ValueNS => true,
572 Def::AssociatedTy(..) if ns == TypeNS => true,
575 PathSource::ImportPrefix => match def {
576 Def::Mod(..) | Def::Enum(..) => true,
579 PathSource::Visibility => match def {
580 Def::Mod(..) => true,
586 fn error_code(self, has_unexpected_resolution: bool) -> &'static str {
587 __diagnostic_used!(E0404);
588 __diagnostic_used!(E0405);
589 __diagnostic_used!(E0412);
590 __diagnostic_used!(E0422);
591 __diagnostic_used!(E0423);
592 __diagnostic_used!(E0425);
593 __diagnostic_used!(E0531);
594 __diagnostic_used!(E0532);
595 __diagnostic_used!(E0573);
596 __diagnostic_used!(E0574);
597 __diagnostic_used!(E0575);
598 __diagnostic_used!(E0576);
599 __diagnostic_used!(E0577);
600 __diagnostic_used!(E0578);
601 match (self, has_unexpected_resolution) {
602 (PathSource::Trait(_), true) => "E0404",
603 (PathSource::Trait(_), false) => "E0405",
604 (PathSource::Type, true) => "E0573",
605 (PathSource::Type, false) => "E0412",
606 (PathSource::Struct, true) => "E0574",
607 (PathSource::Struct, false) => "E0422",
608 (PathSource::Expr(..), true) => "E0423",
609 (PathSource::Expr(..), false) => "E0425",
610 (PathSource::Pat, true) | (PathSource::TupleStruct, true) => "E0532",
611 (PathSource::Pat, false) | (PathSource::TupleStruct, false) => "E0531",
612 (PathSource::TraitItem(..), true) => "E0575",
613 (PathSource::TraitItem(..), false) => "E0576",
614 (PathSource::Visibility, true) | (PathSource::ImportPrefix, true) => "E0577",
615 (PathSource::Visibility, false) | (PathSource::ImportPrefix, false) => "E0578",
620 struct UsePlacementFinder {
621 target_module: NodeId,
626 impl UsePlacementFinder {
627 fn check(krate: &Crate, target_module: NodeId) -> (Option<Span>, bool) {
628 let mut finder = UsePlacementFinder {
633 visit::walk_crate(&mut finder, krate);
634 (finder.span, finder.found_use)
638 impl<'tcx> Visitor<'tcx> for UsePlacementFinder {
641 module: &'tcx ast::Mod,
643 _: &[ast::Attribute],
646 if self.span.is_some() {
649 if node_id != self.target_module {
650 visit::walk_mod(self, module);
653 // find a use statement
654 for item in &module.items {
656 ItemKind::Use(..) => {
657 // don't suggest placing a use before the prelude
658 // import or other generated ones
659 if item.span.ctxt().outer().expn_info().is_none() {
660 self.span = Some(item.span.shrink_to_lo());
661 self.found_use = true;
665 // don't place use before extern crate
666 ItemKind::ExternCrate(_) => {}
667 // but place them before the first other item
668 _ => if self.span.map_or(true, |span| item.span < span ) {
669 if item.span.ctxt().outer().expn_info().is_none() {
670 // don't insert between attributes and an item
671 if item.attrs.is_empty() {
672 self.span = Some(item.span.shrink_to_lo());
674 // find the first attribute on the item
675 for attr in &item.attrs {
676 if self.span.map_or(true, |span| attr.span < span) {
677 self.span = Some(attr.span.shrink_to_lo());
688 /// This thing walks the whole crate in DFS manner, visiting each item, resolving names as it goes.
689 impl<'a, 'tcx> Visitor<'tcx> for Resolver<'a> {
690 fn visit_item(&mut self, item: &'tcx Item) {
691 self.resolve_item(item);
693 fn visit_arm(&mut self, arm: &'tcx Arm) {
694 self.resolve_arm(arm);
696 fn visit_block(&mut self, block: &'tcx Block) {
697 self.resolve_block(block);
699 fn visit_anon_const(&mut self, constant: &'tcx ast::AnonConst) {
700 self.with_constant_rib(|this| {
701 visit::walk_anon_const(this, constant);
704 fn visit_expr(&mut self, expr: &'tcx Expr) {
705 self.resolve_expr(expr, None);
707 fn visit_local(&mut self, local: &'tcx Local) {
708 self.resolve_local(local);
710 fn visit_ty(&mut self, ty: &'tcx Ty) {
712 TyKind::Path(ref qself, ref path) => {
713 self.smart_resolve_path(ty.id, qself.as_ref(), path, PathSource::Type);
715 TyKind::ImplicitSelf => {
716 let self_ty = keywords::SelfType.ident();
717 let def = self.resolve_ident_in_lexical_scope(self_ty, TypeNS, true, ty.span)
718 .map_or(Def::Err, |d| d.def());
719 self.record_def(ty.id, PathResolution::new(def));
723 visit::walk_ty(self, ty);
725 fn visit_poly_trait_ref(&mut self,
726 tref: &'tcx ast::PolyTraitRef,
727 m: &'tcx ast::TraitBoundModifier) {
728 self.smart_resolve_path(tref.trait_ref.ref_id, None,
729 &tref.trait_ref.path, PathSource::Trait(AliasPossibility::Maybe));
730 visit::walk_poly_trait_ref(self, tref, m);
732 fn visit_foreign_item(&mut self, foreign_item: &'tcx ForeignItem) {
733 let type_parameters = match foreign_item.node {
734 ForeignItemKind::Fn(_, ref generics) => {
735 HasTypeParameters(generics, ItemRibKind)
737 ForeignItemKind::Static(..) => NoTypeParameters,
738 ForeignItemKind::Ty => NoTypeParameters,
739 ForeignItemKind::Macro(..) => NoTypeParameters,
741 self.with_type_parameter_rib(type_parameters, |this| {
742 visit::walk_foreign_item(this, foreign_item);
745 fn visit_fn(&mut self,
746 function_kind: FnKind<'tcx>,
747 declaration: &'tcx FnDecl,
751 let (rib_kind, asyncness) = match function_kind {
752 FnKind::ItemFn(_, ref header, ..) =>
753 (ItemRibKind, header.asyncness),
754 FnKind::Method(_, ref sig, _, _) =>
755 (TraitOrImplItemRibKind, sig.header.asyncness),
756 FnKind::Closure(_) =>
757 // Async closures aren't resolved through `visit_fn`-- they're
758 // processed separately
759 (ClosureRibKind(node_id), IsAsync::NotAsync),
762 // Create a value rib for the function.
763 self.ribs[ValueNS].push(Rib::new(rib_kind));
765 // Create a label rib for the function.
766 self.label_ribs.push(Rib::new(rib_kind));
768 // Add each argument to the rib.
769 let mut bindings_list = FxHashMap();
770 for argument in &declaration.inputs {
771 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
773 self.visit_ty(&argument.ty);
775 debug!("(resolving function) recorded argument");
777 visit::walk_fn_ret_ty(self, &declaration.output);
779 // Resolve the function body, potentially inside the body of an async closure
780 if let IsAsync::Async(async_closure_id) = asyncness {
781 let rib_kind = ClosureRibKind(async_closure_id);
782 self.ribs[ValueNS].push(Rib::new(rib_kind));
783 self.label_ribs.push(Rib::new(rib_kind));
786 match function_kind {
787 FnKind::ItemFn(.., body) |
788 FnKind::Method(.., body) => {
789 self.visit_block(body);
791 FnKind::Closure(body) => {
792 self.visit_expr(body);
796 // Leave the body of the async closure
797 if asyncness.is_async() {
798 self.label_ribs.pop();
799 self.ribs[ValueNS].pop();
802 debug!("(resolving function) leaving function");
804 self.label_ribs.pop();
805 self.ribs[ValueNS].pop();
807 fn visit_generics(&mut self, generics: &'tcx Generics) {
808 // For type parameter defaults, we have to ban access
809 // to following type parameters, as the Substs can only
810 // provide previous type parameters as they're built. We
811 // put all the parameters on the ban list and then remove
812 // them one by one as they are processed and become available.
813 let mut default_ban_rib = Rib::new(ForwardTyParamBanRibKind);
814 let mut found_default = false;
815 default_ban_rib.bindings.extend(generics.params.iter()
816 .filter_map(|param| match param.kind {
817 GenericParamKind::Lifetime { .. } => None,
818 GenericParamKind::Type { ref default, .. } => {
819 if found_default || default.is_some() {
820 found_default = true;
821 return Some((Ident::with_empty_ctxt(param.ident.name), Def::Err));
827 for param in &generics.params {
829 GenericParamKind::Lifetime { .. } => self.visit_generic_param(param),
830 GenericParamKind::Type { ref default, .. } => {
831 for bound in ¶m.bounds {
832 self.visit_param_bound(bound);
835 if let Some(ref ty) = default {
836 self.ribs[TypeNS].push(default_ban_rib);
838 default_ban_rib = self.ribs[TypeNS].pop().unwrap();
841 // Allow all following defaults to refer to this type parameter.
842 default_ban_rib.bindings.remove(&Ident::with_empty_ctxt(param.ident.name));
846 for p in &generics.where_clause.predicates {
847 self.visit_where_predicate(p);
852 #[derive(Copy, Clone)]
853 enum TypeParameters<'a, 'b> {
855 HasTypeParameters(// Type parameters.
858 // The kind of the rib used for type parameters.
862 /// The rib kind controls the translation of local
863 /// definitions (`Def::Local`) to upvars (`Def::Upvar`).
864 #[derive(Copy, Clone, Debug)]
866 /// No translation needs to be applied.
869 /// We passed through a closure scope at the given node ID.
870 /// Translate upvars as appropriate.
871 ClosureRibKind(NodeId /* func id */),
873 /// We passed through an impl or trait and are now in one of its
874 /// methods or associated types. Allow references to ty params that impl or trait
875 /// binds. Disallow any other upvars (including other ty params that are
877 TraitOrImplItemRibKind,
879 /// We passed through an item scope. Disallow upvars.
882 /// We're in a constant item. Can't refer to dynamic stuff.
885 /// We passed through a module.
886 ModuleRibKind(Module<'a>),
888 /// We passed through a `macro_rules!` statement
889 MacroDefinition(DefId),
891 /// All bindings in this rib are type parameters that can't be used
892 /// from the default of a type parameter because they're not declared
893 /// before said type parameter. Also see the `visit_generics` override.
894 ForwardTyParamBanRibKind,
899 /// A rib represents a scope names can live in. Note that these appear in many places, not just
900 /// around braces. At any place where the list of accessible names (of the given namespace)
901 /// changes or a new restrictions on the name accessibility are introduced, a new rib is put onto a
902 /// stack. This may be, for example, a `let` statement (because it introduces variables), a macro,
905 /// Different [rib kinds](enum.RibKind) are transparent for different names.
907 /// The resolution keeps a separate stack of ribs as it traverses the AST for each namespace. When
908 /// resolving, the name is looked up from inside out.
911 bindings: FxHashMap<Ident, Def>,
916 fn new(kind: RibKind<'a>) -> Rib<'a> {
918 bindings: FxHashMap(),
924 /// An intermediate resolution result.
926 /// This refers to the thing referred by a name. The difference between `Def` and `Item` is that
927 /// items are visible in their whole block, while defs only from the place they are defined
929 enum LexicalScopeBinding<'a> {
930 Item(&'a NameBinding<'a>),
934 impl<'a> LexicalScopeBinding<'a> {
935 fn item(self) -> Option<&'a NameBinding<'a>> {
937 LexicalScopeBinding::Item(binding) => Some(binding),
942 fn def(self) -> Def {
944 LexicalScopeBinding::Item(binding) => binding.def(),
945 LexicalScopeBinding::Def(def) => def,
950 #[derive(Clone, Debug)]
951 enum PathResult<'a> {
953 NonModule(PathResolution),
955 Failed(Span, String, bool /* is the error from the last segment? */),
959 /// An anonymous module, eg. just a block.
964 /// { // This is an anonymous module
965 /// f(); // This resolves to (2) as we are inside the block.
968 /// f(); // Resolves to (1)
972 /// Any module with a name.
976 /// * A normal module ‒ either `mod from_file;` or `mod from_block { }`.
977 /// * A trait or an enum (it implicitly contains associated types, methods and variant
982 /// One node in the tree of modules.
983 pub struct ModuleData<'a> {
984 parent: Option<Module<'a>>,
987 // The def id of the closest normal module (`mod`) ancestor (including this module).
988 normal_ancestor_id: DefId,
990 resolutions: RefCell<FxHashMap<(Ident, Namespace), &'a RefCell<NameResolution<'a>>>>,
991 legacy_macro_resolutions: RefCell<Vec<(Mark, Ident, MacroKind, Option<Def>)>>,
992 macro_resolutions: RefCell<Vec<(Box<[Ident]>, Span)>>,
994 // Macro invocations that can expand into items in this module.
995 unresolved_invocations: RefCell<FxHashSet<Mark>>,
997 no_implicit_prelude: bool,
999 glob_importers: RefCell<Vec<&'a ImportDirective<'a>>>,
1000 globs: RefCell<Vec<&'a ImportDirective<'a>>>,
1002 // Used to memoize the traits in this module for faster searches through all traits in scope.
1003 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
1005 // Whether this module is populated. If not populated, any attempt to
1006 // access the children must be preceded with a
1007 // `populate_module_if_necessary` call.
1008 populated: Cell<bool>,
1010 /// Span of the module itself. Used for error reporting.
1016 type Module<'a> = &'a ModuleData<'a>;
1018 impl<'a> ModuleData<'a> {
1019 fn new(parent: Option<Module<'a>>,
1021 normal_ancestor_id: DefId,
1023 span: Span) -> Self {
1028 resolutions: RefCell::new(FxHashMap()),
1029 legacy_macro_resolutions: RefCell::new(Vec::new()),
1030 macro_resolutions: RefCell::new(Vec::new()),
1031 unresolved_invocations: RefCell::new(FxHashSet()),
1032 no_implicit_prelude: false,
1033 glob_importers: RefCell::new(Vec::new()),
1034 globs: RefCell::new(Vec::new()),
1035 traits: RefCell::new(None),
1036 populated: Cell::new(normal_ancestor_id.is_local()),
1042 fn for_each_child<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
1043 for (&(ident, ns), name_resolution) in self.resolutions.borrow().iter() {
1044 name_resolution.borrow().binding.map(|binding| f(ident, ns, binding));
1048 fn for_each_child_stable<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
1049 let resolutions = self.resolutions.borrow();
1050 let mut resolutions = resolutions.iter().collect::<Vec<_>>();
1051 resolutions.sort_by_cached_key(|&(&(ident, ns), _)| (ident.as_str(), ns));
1052 for &(&(ident, ns), &resolution) in resolutions.iter() {
1053 resolution.borrow().binding.map(|binding| f(ident, ns, binding));
1057 fn def(&self) -> Option<Def> {
1059 ModuleKind::Def(def, _) => Some(def),
1064 fn def_id(&self) -> Option<DefId> {
1065 self.def().as_ref().map(Def::def_id)
1068 // `self` resolves to the first module ancestor that `is_normal`.
1069 fn is_normal(&self) -> bool {
1071 ModuleKind::Def(Def::Mod(_), _) => true,
1076 fn is_trait(&self) -> bool {
1078 ModuleKind::Def(Def::Trait(_), _) => true,
1083 fn is_local(&self) -> bool {
1084 self.normal_ancestor_id.is_local()
1087 fn nearest_item_scope(&'a self) -> Module<'a> {
1088 if self.is_trait() { self.parent.unwrap() } else { self }
1092 impl<'a> fmt::Debug for ModuleData<'a> {
1093 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1094 write!(f, "{:?}", self.def())
1098 /// Records a possibly-private value, type, or module definition.
1099 #[derive(Clone, Debug)]
1100 pub struct NameBinding<'a> {
1101 kind: NameBindingKind<'a>,
1104 vis: ty::Visibility,
1107 pub trait ToNameBinding<'a> {
1108 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
1111 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
1112 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
1117 #[derive(Clone, Debug)]
1118 enum NameBindingKind<'a> {
1122 binding: &'a NameBinding<'a>,
1123 directive: &'a ImportDirective<'a>,
1127 b1: &'a NameBinding<'a>,
1128 b2: &'a NameBinding<'a>,
1132 struct PrivacyError<'a>(Span, Name, &'a NameBinding<'a>);
1134 struct UseError<'a> {
1135 err: DiagnosticBuilder<'a>,
1136 /// Attach `use` statements for these candidates
1137 candidates: Vec<ImportSuggestion>,
1138 /// The node id of the module to place the use statements in
1140 /// Whether the diagnostic should state that it's "better"
1144 struct AmbiguityError<'a> {
1148 b1: &'a NameBinding<'a>,
1149 b2: &'a NameBinding<'a>,
1152 impl<'a> NameBinding<'a> {
1153 fn module(&self) -> Option<Module<'a>> {
1155 NameBindingKind::Module(module) => Some(module),
1156 NameBindingKind::Import { binding, .. } => binding.module(),
1161 fn def(&self) -> Def {
1163 NameBindingKind::Def(def) => def,
1164 NameBindingKind::Module(module) => module.def().unwrap(),
1165 NameBindingKind::Import { binding, .. } => binding.def(),
1166 NameBindingKind::Ambiguity { .. } => Def::Err,
1170 fn def_ignoring_ambiguity(&self) -> Def {
1172 NameBindingKind::Import { binding, .. } => binding.def_ignoring_ambiguity(),
1173 NameBindingKind::Ambiguity { b1, .. } => b1.def_ignoring_ambiguity(),
1178 fn get_macro(&self, resolver: &mut Resolver<'a>) -> Lrc<SyntaxExtension> {
1179 resolver.get_macro(self.def_ignoring_ambiguity())
1182 // We sometimes need to treat variants as `pub` for backwards compatibility
1183 fn pseudo_vis(&self) -> ty::Visibility {
1184 if self.is_variant() && self.def().def_id().is_local() {
1185 ty::Visibility::Public
1191 fn is_variant(&self) -> bool {
1193 NameBindingKind::Def(Def::Variant(..)) |
1194 NameBindingKind::Def(Def::VariantCtor(..)) => true,
1199 fn is_extern_crate(&self) -> bool {
1201 NameBindingKind::Import {
1202 directive: &ImportDirective {
1203 subclass: ImportDirectiveSubclass::ExternCrate(_), ..
1210 fn is_import(&self) -> bool {
1212 NameBindingKind::Import { .. } => true,
1217 fn is_renamed_extern_crate(&self) -> bool {
1218 if let NameBindingKind::Import { directive, ..} = self.kind {
1219 if let ImportDirectiveSubclass::ExternCrate(Some(_)) = directive.subclass {
1226 fn is_glob_import(&self) -> bool {
1228 NameBindingKind::Import { directive, .. } => directive.is_glob(),
1229 NameBindingKind::Ambiguity { b1, .. } => b1.is_glob_import(),
1234 fn is_importable(&self) -> bool {
1236 Def::AssociatedConst(..) | Def::Method(..) | Def::AssociatedTy(..) => false,
1241 fn is_macro_def(&self) -> bool {
1243 NameBindingKind::Def(Def::Macro(..)) => true,
1248 fn descr(&self) -> &'static str {
1249 if self.is_extern_crate() { "extern crate" } else { self.def().kind_name() }
1253 /// Interns the names of the primitive types.
1255 /// All other types are defined somewhere and possibly imported, but the primitive ones need
1256 /// special handling, since they have no place of origin.
1257 struct PrimitiveTypeTable {
1258 primitive_types: FxHashMap<Name, PrimTy>,
1261 impl PrimitiveTypeTable {
1262 fn new() -> PrimitiveTypeTable {
1263 let mut table = PrimitiveTypeTable { primitive_types: FxHashMap() };
1265 table.intern("bool", TyBool);
1266 table.intern("char", TyChar);
1267 table.intern("f32", TyFloat(FloatTy::F32));
1268 table.intern("f64", TyFloat(FloatTy::F64));
1269 table.intern("isize", TyInt(IntTy::Isize));
1270 table.intern("i8", TyInt(IntTy::I8));
1271 table.intern("i16", TyInt(IntTy::I16));
1272 table.intern("i32", TyInt(IntTy::I32));
1273 table.intern("i64", TyInt(IntTy::I64));
1274 table.intern("i128", TyInt(IntTy::I128));
1275 table.intern("str", TyStr);
1276 table.intern("usize", TyUint(UintTy::Usize));
1277 table.intern("u8", TyUint(UintTy::U8));
1278 table.intern("u16", TyUint(UintTy::U16));
1279 table.intern("u32", TyUint(UintTy::U32));
1280 table.intern("u64", TyUint(UintTy::U64));
1281 table.intern("u128", TyUint(UintTy::U128));
1285 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1286 self.primitive_types.insert(Symbol::intern(string), primitive_type);
1290 /// The main resolver class.
1292 /// This is the visitor that walks the whole crate.
1293 pub struct Resolver<'a> {
1294 session: &'a Session,
1295 cstore: &'a CrateStore,
1297 pub definitions: Definitions,
1299 graph_root: Module<'a>,
1301 prelude: Option<Module<'a>>,
1302 extern_prelude: FxHashSet<Name>,
1304 /// n.b. This is used only for better diagnostics, not name resolution itself.
1305 has_self: FxHashSet<DefId>,
1307 /// Names of fields of an item `DefId` accessible with dot syntax.
1308 /// Used for hints during error reporting.
1309 field_names: FxHashMap<DefId, Vec<Name>>,
1311 /// All imports known to succeed or fail.
1312 determined_imports: Vec<&'a ImportDirective<'a>>,
1314 /// All non-determined imports.
1315 indeterminate_imports: Vec<&'a ImportDirective<'a>>,
1317 /// The module that represents the current item scope.
1318 current_module: Module<'a>,
1320 /// The current set of local scopes for types and values.
1321 /// FIXME #4948: Reuse ribs to avoid allocation.
1322 ribs: PerNS<Vec<Rib<'a>>>,
1324 /// The current set of local scopes, for labels.
1325 label_ribs: Vec<Rib<'a>>,
1327 /// The trait that the current context can refer to.
1328 current_trait_ref: Option<(Module<'a>, TraitRef)>,
1330 /// The current self type if inside an impl (used for better errors).
1331 current_self_type: Option<Ty>,
1333 /// The idents for the primitive types.
1334 primitive_type_table: PrimitiveTypeTable,
1337 import_map: ImportMap,
1338 pub freevars: FreevarMap,
1339 freevars_seen: NodeMap<NodeMap<usize>>,
1340 pub export_map: ExportMap,
1341 pub trait_map: TraitMap,
1343 /// A map from nodes to anonymous modules.
1344 /// Anonymous modules are pseudo-modules that are implicitly created around items
1345 /// contained within blocks.
1347 /// For example, if we have this:
1355 /// There will be an anonymous module created around `g` with the ID of the
1356 /// entry block for `f`.
1357 block_map: NodeMap<Module<'a>>,
1358 module_map: FxHashMap<DefId, Module<'a>>,
1359 extern_module_map: FxHashMap<(DefId, bool /* MacrosOnly? */), Module<'a>>,
1361 pub make_glob_map: bool,
1362 /// Maps imports to the names of items actually imported (this actually maps
1363 /// all imports, but only glob imports are actually interesting).
1364 pub glob_map: GlobMap,
1366 used_imports: FxHashSet<(NodeId, Namespace)>,
1367 pub maybe_unused_trait_imports: NodeSet,
1368 pub maybe_unused_extern_crates: Vec<(NodeId, Span)>,
1370 /// A list of labels as of yet unused. Labels will be removed from this map when
1371 /// they are used (in a `break` or `continue` statement)
1372 pub unused_labels: FxHashMap<NodeId, Span>,
1374 /// privacy errors are delayed until the end in order to deduplicate them
1375 privacy_errors: Vec<PrivacyError<'a>>,
1376 /// ambiguity errors are delayed for deduplication
1377 ambiguity_errors: Vec<AmbiguityError<'a>>,
1378 /// `use` injections are delayed for better placement and deduplication
1379 use_injections: Vec<UseError<'a>>,
1380 /// `use` injections for proc macros wrongly imported with #[macro_use]
1381 proc_mac_errors: Vec<macros::ProcMacError>,
1383 gated_errors: FxHashSet<Span>,
1384 disallowed_shadowing: Vec<&'a LegacyBinding<'a>>,
1386 arenas: &'a ResolverArenas<'a>,
1387 dummy_binding: &'a NameBinding<'a>,
1388 /// true if `#![feature(use_extern_macros)]`
1389 use_extern_macros: bool,
1391 crate_loader: &'a mut CrateLoader,
1392 macro_names: FxHashSet<Ident>,
1393 global_macros: FxHashMap<Name, &'a NameBinding<'a>>,
1394 pub all_macros: FxHashMap<Name, Def>,
1395 lexical_macro_resolutions: Vec<(Ident, &'a Cell<LegacyScope<'a>>)>,
1396 macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>,
1397 macro_defs: FxHashMap<Mark, DefId>,
1398 local_macro_def_scopes: FxHashMap<NodeId, Module<'a>>,
1399 macro_exports: Vec<Export>,
1400 pub whitelisted_legacy_custom_derives: Vec<Name>,
1401 pub found_unresolved_macro: bool,
1403 /// List of crate local macros that we need to warn about as being unused.
1404 /// Right now this only includes macro_rules! macros, and macros 2.0.
1405 unused_macros: FxHashSet<DefId>,
1407 /// Maps the `Mark` of an expansion to its containing module or block.
1408 invocations: FxHashMap<Mark, &'a InvocationData<'a>>,
1410 /// Avoid duplicated errors for "name already defined".
1411 name_already_seen: FxHashMap<Name, Span>,
1413 /// If `#![feature(proc_macro)]` is set
1414 proc_macro_enabled: bool,
1416 /// A set of procedural macros imported by `#[macro_use]` that have already been warned about
1417 warned_proc_macros: FxHashSet<Name>,
1419 potentially_unused_imports: Vec<&'a ImportDirective<'a>>,
1421 /// This table maps struct IDs into struct constructor IDs,
1422 /// it's not used during normal resolution, only for better error reporting.
1423 struct_constructors: DefIdMap<(Def, ty::Visibility)>,
1425 /// Only used for better errors on `fn(): fn()`
1426 current_type_ascription: Vec<Span>,
1428 injected_crate: Option<Module<'a>>,
1430 /// Only supposed to be used by rustdoc, otherwise should be false.
1431 pub ignore_extern_prelude_feature: bool,
1434 /// Nothing really interesting here, it just provides memory for the rest of the crate.
1435 pub struct ResolverArenas<'a> {
1436 modules: arena::TypedArena<ModuleData<'a>>,
1437 local_modules: RefCell<Vec<Module<'a>>>,
1438 name_bindings: arena::TypedArena<NameBinding<'a>>,
1439 import_directives: arena::TypedArena<ImportDirective<'a>>,
1440 name_resolutions: arena::TypedArena<RefCell<NameResolution<'a>>>,
1441 invocation_data: arena::TypedArena<InvocationData<'a>>,
1442 legacy_bindings: arena::TypedArena<LegacyBinding<'a>>,
1445 impl<'a> ResolverArenas<'a> {
1446 fn alloc_module(&'a self, module: ModuleData<'a>) -> Module<'a> {
1447 let module = self.modules.alloc(module);
1448 if module.def_id().map(|def_id| def_id.is_local()).unwrap_or(true) {
1449 self.local_modules.borrow_mut().push(module);
1453 fn local_modules(&'a self) -> ::std::cell::Ref<'a, Vec<Module<'a>>> {
1454 self.local_modules.borrow()
1456 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1457 self.name_bindings.alloc(name_binding)
1459 fn alloc_import_directive(&'a self, import_directive: ImportDirective<'a>)
1460 -> &'a ImportDirective {
1461 self.import_directives.alloc(import_directive)
1463 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1464 self.name_resolutions.alloc(Default::default())
1466 fn alloc_invocation_data(&'a self, expansion_data: InvocationData<'a>)
1467 -> &'a InvocationData<'a> {
1468 self.invocation_data.alloc(expansion_data)
1470 fn alloc_legacy_binding(&'a self, binding: LegacyBinding<'a>) -> &'a LegacyBinding<'a> {
1471 self.legacy_bindings.alloc(binding)
1475 impl<'a, 'b: 'a> ty::DefIdTree for &'a Resolver<'b> {
1476 fn parent(self, id: DefId) -> Option<DefId> {
1478 LOCAL_CRATE => self.definitions.def_key(id.index).parent,
1479 _ => self.cstore.def_key(id).parent,
1480 }.map(|index| DefId { index, ..id })
1484 /// This interface is used through the AST→HIR step, to embed full paths into the HIR. After that
1485 /// the resolver is no longer needed as all the relevant information is inline.
1486 impl<'a> hir::lowering::Resolver for Resolver<'a> {
1487 fn resolve_hir_path(&mut self, path: &mut hir::Path, is_value: bool) {
1488 self.resolve_hir_path_cb(path, is_value,
1489 |resolver, span, error| resolve_error(resolver, span, error))
1492 fn resolve_str_path(
1495 crate_root: Option<&str>,
1496 components: &[&str],
1497 args: Option<P<hir::GenericArgs>>,
1500 let mut segments = iter::once(keywords::CrateRoot.name())
1502 crate_root.into_iter()
1503 .chain(components.iter().cloned())
1504 .map(Symbol::intern)
1505 ).map(hir::PathSegment::from_name).collect::<Vec<_>>();
1507 if let Some(args) = args {
1508 let name = segments.last().unwrap().name;
1509 *segments.last_mut().unwrap() = hir::PathSegment {
1516 let mut path = hir::Path {
1519 segments: segments.into(),
1522 self.resolve_hir_path(&mut path, is_value);
1526 fn get_resolution(&mut self, id: NodeId) -> Option<PathResolution> {
1527 self.def_map.get(&id).cloned()
1530 fn get_import(&mut self, id: NodeId) -> PerNS<Option<PathResolution>> {
1531 self.import_map.get(&id).cloned().unwrap_or_default()
1534 fn definitions(&mut self) -> &mut Definitions {
1535 &mut self.definitions
1539 impl<'a> Resolver<'a> {
1540 /// Rustdoc uses this to resolve things in a recoverable way. ResolutionError<'a>
1541 /// isn't something that can be returned because it can't be made to live that long,
1542 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
1543 /// just that an error occurred.
1544 pub fn resolve_str_path_error(&mut self, span: Span, path_str: &str, is_value: bool)
1545 -> Result<hir::Path, ()> {
1547 let mut errored = false;
1549 let mut path = if path_str.starts_with("::") {
1553 segments: iter::once(keywords::CrateRoot.name()).chain({
1554 path_str.split("::").skip(1).map(Symbol::intern)
1555 }).map(hir::PathSegment::from_name).collect(),
1561 segments: path_str.split("::").map(Symbol::intern)
1562 .map(hir::PathSegment::from_name).collect(),
1565 self.resolve_hir_path_cb(&mut path, is_value, |_, _, _| errored = true);
1566 if errored || path.def == Def::Err {
1573 /// resolve_hir_path, but takes a callback in case there was an error
1574 fn resolve_hir_path_cb<F>(&mut self, path: &mut hir::Path, is_value: bool, error_callback: F)
1575 where F: for<'c, 'b> FnOnce(&'c mut Resolver, Span, ResolutionError<'b>)
1577 let namespace = if is_value { ValueNS } else { TypeNS };
1578 let hir::Path { ref segments, span, ref mut def } = *path;
1579 let path: Vec<Ident> = segments.iter()
1580 .map(|seg| Ident::new(seg.name, span))
1582 // FIXME (Manishearth): Intra doc links won't get warned of epoch changes
1583 match self.resolve_path(&path, Some(namespace), true, span, CrateLint::No) {
1584 PathResult::Module(module) => *def = module.def().unwrap(),
1585 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 =>
1586 *def = path_res.base_def(),
1587 PathResult::NonModule(..) => match self.resolve_path(
1594 PathResult::Failed(span, msg, _) => {
1595 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1599 PathResult::Indeterminate => unreachable!(),
1600 PathResult::Failed(span, msg, _) => {
1601 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1607 impl<'a> Resolver<'a> {
1608 pub fn new(session: &'a Session,
1609 cstore: &'a CrateStore,
1612 make_glob_map: MakeGlobMap,
1613 crate_loader: &'a mut CrateLoader,
1614 arenas: &'a ResolverArenas<'a>)
1616 let root_def_id = DefId::local(CRATE_DEF_INDEX);
1617 let root_module_kind = ModuleKind::Def(Def::Mod(root_def_id), keywords::Invalid.name());
1618 let graph_root = arenas.alloc_module(ModuleData {
1619 no_implicit_prelude: attr::contains_name(&krate.attrs, "no_implicit_prelude"),
1620 ..ModuleData::new(None, root_module_kind, root_def_id, Mark::root(), krate.span)
1622 let mut module_map = FxHashMap();
1623 module_map.insert(DefId::local(CRATE_DEF_INDEX), graph_root);
1625 let mut definitions = Definitions::new();
1626 DefCollector::new(&mut definitions, Mark::root())
1627 .collect_root(crate_name, session.local_crate_disambiguator());
1629 let mut extern_prelude: FxHashSet<Name> =
1630 session.opts.externs.iter().map(|kv| Symbol::intern(kv.0)).collect();
1631 if !attr::contains_name(&krate.attrs, "no_core") {
1632 if !attr::contains_name(&krate.attrs, "no_std") {
1633 extern_prelude.insert(Symbol::intern("std"));
1635 extern_prelude.insert(Symbol::intern("core"));
1639 let mut invocations = FxHashMap();
1640 invocations.insert(Mark::root(),
1641 arenas.alloc_invocation_data(InvocationData::root(graph_root)));
1643 let features = session.features_untracked();
1645 let mut macro_defs = FxHashMap();
1646 macro_defs.insert(Mark::root(), root_def_id);
1655 // The outermost module has def ID 0; this is not reflected in the
1661 has_self: FxHashSet(),
1662 field_names: FxHashMap(),
1664 determined_imports: Vec::new(),
1665 indeterminate_imports: Vec::new(),
1667 current_module: graph_root,
1669 value_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1670 type_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1671 macro_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1673 label_ribs: Vec::new(),
1675 current_trait_ref: None,
1676 current_self_type: None,
1678 primitive_type_table: PrimitiveTypeTable::new(),
1681 import_map: NodeMap(),
1682 freevars: NodeMap(),
1683 freevars_seen: NodeMap(),
1684 export_map: FxHashMap(),
1685 trait_map: NodeMap(),
1687 block_map: NodeMap(),
1688 extern_module_map: FxHashMap(),
1690 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1691 glob_map: NodeMap(),
1693 used_imports: FxHashSet(),
1694 maybe_unused_trait_imports: NodeSet(),
1695 maybe_unused_extern_crates: Vec::new(),
1697 unused_labels: FxHashMap(),
1699 privacy_errors: Vec::new(),
1700 ambiguity_errors: Vec::new(),
1701 use_injections: Vec::new(),
1702 proc_mac_errors: Vec::new(),
1703 gated_errors: FxHashSet(),
1704 disallowed_shadowing: Vec::new(),
1707 dummy_binding: arenas.alloc_name_binding(NameBinding {
1708 kind: NameBindingKind::Def(Def::Err),
1709 expansion: Mark::root(),
1711 vis: ty::Visibility::Public,
1714 // The `proc_macro` and `decl_macro` features imply `use_extern_macros`
1716 features.use_extern_macros || features.proc_macro || features.decl_macro,
1719 macro_names: FxHashSet(),
1720 global_macros: FxHashMap(),
1721 all_macros: FxHashMap(),
1722 lexical_macro_resolutions: Vec::new(),
1723 macro_map: FxHashMap(),
1724 macro_exports: Vec::new(),
1727 local_macro_def_scopes: FxHashMap(),
1728 name_already_seen: FxHashMap(),
1729 whitelisted_legacy_custom_derives: Vec::new(),
1730 proc_macro_enabled: features.proc_macro,
1731 warned_proc_macros: FxHashSet(),
1732 potentially_unused_imports: Vec::new(),
1733 struct_constructors: DefIdMap(),
1734 found_unresolved_macro: false,
1735 unused_macros: FxHashSet(),
1736 current_type_ascription: Vec::new(),
1737 injected_crate: None,
1738 ignore_extern_prelude_feature: false,
1742 pub fn arenas() -> ResolverArenas<'a> {
1744 modules: arena::TypedArena::new(),
1745 local_modules: RefCell::new(Vec::new()),
1746 name_bindings: arena::TypedArena::new(),
1747 import_directives: arena::TypedArena::new(),
1748 name_resolutions: arena::TypedArena::new(),
1749 invocation_data: arena::TypedArena::new(),
1750 legacy_bindings: arena::TypedArena::new(),
1754 /// Runs the function on each namespace.
1755 fn per_ns<F: FnMut(&mut Self, Namespace)>(&mut self, mut f: F) {
1758 if self.use_extern_macros {
1763 fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
1765 match self.macro_defs.get(&ctxt.outer()) {
1766 Some(&def_id) => return def_id,
1767 None => ctxt.remove_mark(),
1772 /// Entry point to crate resolution.
1773 pub fn resolve_crate(&mut self, krate: &Crate) {
1774 ImportResolver { resolver: self }.finalize_imports();
1775 self.current_module = self.graph_root;
1776 self.finalize_current_module_macro_resolutions();
1778 visit::walk_crate(self, krate);
1780 check_unused::check_crate(self, krate);
1781 self.report_errors(krate);
1782 self.crate_loader.postprocess(krate);
1789 normal_ancestor_id: DefId,
1793 let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expansion, span);
1794 self.arenas.alloc_module(module)
1797 fn record_use(&mut self, ident: Ident, ns: Namespace, binding: &'a NameBinding<'a>, span: Span)
1798 -> bool /* true if an error was reported */ {
1799 match binding.kind {
1800 NameBindingKind::Import { directive, binding, ref used }
1803 directive.used.set(true);
1804 self.used_imports.insert((directive.id, ns));
1805 self.add_to_glob_map(directive.id, ident);
1806 self.record_use(ident, ns, binding, span)
1808 NameBindingKind::Import { .. } => false,
1809 NameBindingKind::Ambiguity { b1, b2 } => {
1810 self.ambiguity_errors.push(AmbiguityError {
1811 span, name: ident.name, lexical: false, b1, b2,
1819 fn add_to_glob_map(&mut self, id: NodeId, ident: Ident) {
1820 if self.make_glob_map {
1821 self.glob_map.entry(id).or_insert_with(FxHashSet).insert(ident.name);
1825 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1826 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1827 /// `ident` in the first scope that defines it (or None if no scopes define it).
1829 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1830 /// the items are defined in the block. For example,
1833 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1836 /// g(); // This resolves to the local variable `g` since it shadows the item.
1840 /// Invariant: This must only be called during main resolution, not during
1841 /// import resolution.
1842 fn resolve_ident_in_lexical_scope(&mut self,
1847 -> Option<LexicalScopeBinding<'a>> {
1849 ident.span = if ident.name == keywords::SelfType.name() {
1850 // FIXME(jseyfried) improve `Self` hygiene
1851 ident.span.with_ctxt(SyntaxContext::empty())
1857 // Walk backwards up the ribs in scope.
1858 let mut module = self.graph_root;
1859 for i in (0 .. self.ribs[ns].len()).rev() {
1860 if let Some(def) = self.ribs[ns][i].bindings.get(&ident).cloned() {
1861 // The ident resolves to a type parameter or local variable.
1862 return Some(LexicalScopeBinding::Def(
1863 self.adjust_local_def(ns, i, def, record_used, path_span)
1867 module = match self.ribs[ns][i].kind {
1868 ModuleRibKind(module) => module,
1869 MacroDefinition(def) if def == self.macro_def(ident.span.ctxt()) => {
1870 // If an invocation of this macro created `ident`, give up on `ident`
1871 // and switch to `ident`'s source from the macro definition.
1872 ident.span.remove_mark();
1878 let item = self.resolve_ident_in_module_unadjusted(
1879 module, ident, ns, false, record_used, path_span,
1881 if let Ok(binding) = item {
1882 // The ident resolves to an item.
1883 return Some(LexicalScopeBinding::Item(binding));
1887 ModuleKind::Block(..) => {}, // We can see through blocks
1892 ident.span = ident.span.modern();
1894 module = unwrap_or!(self.hygienic_lexical_parent(module, &mut ident.span), break);
1895 let orig_current_module = self.current_module;
1896 self.current_module = module; // Lexical resolutions can never be a privacy error.
1897 let result = self.resolve_ident_in_module_unadjusted(
1898 module, ident, ns, false, record_used, path_span,
1900 self.current_module = orig_current_module;
1903 Ok(binding) => return Some(LexicalScopeBinding::Item(binding)),
1904 Err(Undetermined) => return None,
1905 Err(Determined) => {}
1909 if !module.no_implicit_prelude {
1910 // `record_used` means that we don't try to load crates during speculative resolution
1911 if record_used && ns == TypeNS && self.extern_prelude.contains(&ident.name) {
1912 if !self.session.features_untracked().extern_prelude &&
1913 !self.ignore_extern_prelude_feature {
1914 feature_err(&self.session.parse_sess, "extern_prelude",
1915 ident.span, GateIssue::Language,
1916 "access to extern crates through prelude is experimental").emit();
1919 let crate_id = self.crate_loader.process_path_extern(ident.name, ident.span);
1920 let crate_root = self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
1921 self.populate_module_if_necessary(crate_root);
1923 let binding = (crate_root, ty::Visibility::Public,
1924 ident.span, Mark::root()).to_name_binding(self.arenas);
1925 return Some(LexicalScopeBinding::Item(binding));
1927 if let Some(prelude) = self.prelude {
1928 if let Ok(binding) = self.resolve_ident_in_module_unadjusted(prelude, ident, ns,
1929 false, false, path_span) {
1930 return Some(LexicalScopeBinding::Item(binding));
1938 fn hygienic_lexical_parent(&mut self, mut module: Module<'a>, span: &mut Span)
1939 -> Option<Module<'a>> {
1940 if !module.expansion.is_descendant_of(span.ctxt().outer()) {
1941 return Some(self.macro_def_scope(span.remove_mark()));
1944 if let ModuleKind::Block(..) = module.kind {
1945 return Some(module.parent.unwrap());
1948 let mut module_expansion = module.expansion.modern(); // for backward compatibility
1949 while let Some(parent) = module.parent {
1950 let parent_expansion = parent.expansion.modern();
1951 if module_expansion.is_descendant_of(parent_expansion) &&
1952 parent_expansion != module_expansion {
1953 return if parent_expansion.is_descendant_of(span.ctxt().outer()) {
1960 module_expansion = parent_expansion;
1966 fn resolve_ident_in_module(&mut self,
1970 ignore_unresolved_invocations: bool,
1973 -> Result<&'a NameBinding<'a>, Determinacy> {
1974 ident.span = ident.span.modern();
1975 let orig_current_module = self.current_module;
1976 if let Some(def) = ident.span.adjust(module.expansion) {
1977 self.current_module = self.macro_def_scope(def);
1979 let result = self.resolve_ident_in_module_unadjusted(
1980 module, ident, ns, ignore_unresolved_invocations, record_used, span,
1982 self.current_module = orig_current_module;
1986 fn resolve_crate_root(&mut self, mut ctxt: SyntaxContext, legacy: bool) -> Module<'a> {
1987 let mark = if legacy {
1988 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
1989 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
1990 // as described in `SyntaxContext::apply_mark`, so we ignore prepended modern marks.
1991 ctxt.marks().into_iter().find(|&mark| mark.transparency() != Transparency::Opaque)
1993 ctxt = ctxt.modern();
1994 ctxt.adjust(Mark::root())
1996 let module = match mark {
1997 Some(def) => self.macro_def_scope(def),
1998 None => return self.graph_root,
2000 self.get_module(DefId { index: CRATE_DEF_INDEX, ..module.normal_ancestor_id })
2003 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
2004 let mut module = self.get_module(module.normal_ancestor_id);
2005 while module.span.ctxt().modern() != *ctxt {
2006 let parent = module.parent.unwrap_or_else(|| self.macro_def_scope(ctxt.remove_mark()));
2007 module = self.get_module(parent.normal_ancestor_id);
2014 // We maintain a list of value ribs and type ribs.
2016 // Simultaneously, we keep track of the current position in the module
2017 // graph in the `current_module` pointer. When we go to resolve a name in
2018 // the value or type namespaces, we first look through all the ribs and
2019 // then query the module graph. When we resolve a name in the module
2020 // namespace, we can skip all the ribs (since nested modules are not
2021 // allowed within blocks in Rust) and jump straight to the current module
2024 // Named implementations are handled separately. When we find a method
2025 // call, we consult the module node to find all of the implementations in
2026 // scope. This information is lazily cached in the module node. We then
2027 // generate a fake "implementation scope" containing all the
2028 // implementations thus found, for compatibility with old resolve pass.
2030 pub fn with_scope<F, T>(&mut self, id: NodeId, f: F) -> T
2031 where F: FnOnce(&mut Resolver) -> T
2033 let id = self.definitions.local_def_id(id);
2034 let module = self.module_map.get(&id).cloned(); // clones a reference
2035 if let Some(module) = module {
2036 // Move down in the graph.
2037 let orig_module = replace(&mut self.current_module, module);
2038 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(module)));
2039 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(module)));
2041 self.finalize_current_module_macro_resolutions();
2044 self.current_module = orig_module;
2045 self.ribs[ValueNS].pop();
2046 self.ribs[TypeNS].pop();
2053 /// Searches the current set of local scopes for labels. Returns the first non-None label that
2054 /// is returned by the given predicate function
2056 /// Stops after meeting a closure.
2057 fn search_label<P, R>(&self, mut ident: Ident, pred: P) -> Option<R>
2058 where P: Fn(&Rib, Ident) -> Option<R>
2060 for rib in self.label_ribs.iter().rev() {
2063 // If an invocation of this macro created `ident`, give up on `ident`
2064 // and switch to `ident`'s source from the macro definition.
2065 MacroDefinition(def) => {
2066 if def == self.macro_def(ident.span.ctxt()) {
2067 ident.span.remove_mark();
2071 // Do not resolve labels across function boundary
2075 let r = pred(rib, ident);
2083 fn resolve_item(&mut self, item: &Item) {
2084 let name = item.ident.name;
2086 debug!("(resolving item) resolving {}", name);
2088 self.check_proc_macro_attrs(&item.attrs);
2091 ItemKind::Enum(_, ref generics) |
2092 ItemKind::Ty(_, ref generics) |
2093 ItemKind::Struct(_, ref generics) |
2094 ItemKind::Union(_, ref generics) |
2095 ItemKind::Fn(_, _, ref generics, _) => {
2096 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind),
2097 |this| visit::walk_item(this, item));
2100 ItemKind::Impl(.., ref generics, ref opt_trait_ref, ref self_type, ref impl_items) =>
2101 self.resolve_implementation(generics,
2107 ItemKind::Trait(.., ref generics, ref bounds, ref trait_items) => {
2108 // Create a new rib for the trait-wide type parameters.
2109 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2110 let local_def_id = this.definitions.local_def_id(item.id);
2111 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2112 this.visit_generics(generics);
2113 walk_list!(this, visit_param_bound, bounds);
2115 for trait_item in trait_items {
2116 this.check_proc_macro_attrs(&trait_item.attrs);
2118 let type_parameters = HasTypeParameters(&trait_item.generics,
2119 TraitOrImplItemRibKind);
2120 this.with_type_parameter_rib(type_parameters, |this| {
2121 match trait_item.node {
2122 TraitItemKind::Const(ref ty, ref default) => {
2125 // Only impose the restrictions of
2126 // ConstRibKind for an actual constant
2127 // expression in a provided default.
2128 if let Some(ref expr) = *default{
2129 this.with_constant_rib(|this| {
2130 this.visit_expr(expr);
2134 TraitItemKind::Method(_, _) => {
2135 visit::walk_trait_item(this, trait_item)
2137 TraitItemKind::Type(..) => {
2138 visit::walk_trait_item(this, trait_item)
2140 TraitItemKind::Macro(_) => {
2141 panic!("unexpanded macro in resolve!")
2150 ItemKind::TraitAlias(ref generics, ref bounds) => {
2151 // Create a new rib for the trait-wide type parameters.
2152 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2153 let local_def_id = this.definitions.local_def_id(item.id);
2154 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2155 this.visit_generics(generics);
2156 walk_list!(this, visit_param_bound, bounds);
2161 ItemKind::Mod(_) | ItemKind::ForeignMod(_) => {
2162 self.with_scope(item.id, |this| {
2163 visit::walk_item(this, item);
2167 ItemKind::Static(ref ty, _, ref expr) |
2168 ItemKind::Const(ref ty, ref expr) => {
2169 self.with_item_rib(|this| {
2171 this.with_constant_rib(|this| {
2172 this.visit_expr(expr);
2177 ItemKind::Use(ref use_tree) => {
2178 // Imports are resolved as global by default, add starting root segment.
2180 segments: use_tree.prefix.make_root().into_iter().collect(),
2181 span: use_tree.span,
2183 self.resolve_use_tree(item.id, use_tree.span, item.id, use_tree, &path);
2186 ItemKind::ExternCrate(_) | ItemKind::MacroDef(..) | ItemKind::GlobalAsm(_) => {
2187 // do nothing, these are just around to be encoded
2190 ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"),
2194 /// For the most part, use trees are desugared into `ImportDirective` instances
2195 /// when building the reduced graph (see `build_reduced_graph_for_use_tree`). But
2196 /// there is one special case we handle here: an empty nested import like
2197 /// `a::{b::{}}`, which desugares into...no import directives.
2198 fn resolve_use_tree(
2203 use_tree: &ast::UseTree,
2206 match use_tree.kind {
2207 ast::UseTreeKind::Nested(ref items) => {
2209 segments: prefix.segments
2211 .chain(use_tree.prefix.segments.iter())
2214 span: prefix.span.to(use_tree.prefix.span),
2217 if items.len() == 0 {
2218 // Resolve prefix of an import with empty braces (issue #28388).
2219 self.smart_resolve_path_with_crate_lint(
2223 PathSource::ImportPrefix,
2224 CrateLint::UsePath { root_id, root_span },
2227 for &(ref tree, nested_id) in items {
2228 self.resolve_use_tree(root_id, root_span, nested_id, tree, &path);
2232 ast::UseTreeKind::Simple(..) => {},
2233 ast::UseTreeKind::Glob => {},
2237 fn with_type_parameter_rib<'b, F>(&'b mut self, type_parameters: TypeParameters<'a, 'b>, f: F)
2238 where F: FnOnce(&mut Resolver)
2240 match type_parameters {
2241 HasTypeParameters(generics, rib_kind) => {
2242 let mut function_type_rib = Rib::new(rib_kind);
2243 let mut seen_bindings = FxHashMap();
2244 generics.params.iter().for_each(|param| match param.kind {
2245 GenericParamKind::Lifetime { .. } => {}
2246 GenericParamKind::Type { .. } => {
2247 let ident = param.ident.modern();
2248 debug!("with_type_parameter_rib: {}", param.id);
2250 if seen_bindings.contains_key(&ident) {
2251 let span = seen_bindings.get(&ident).unwrap();
2252 let err = ResolutionError::NameAlreadyUsedInTypeParameterList(
2256 resolve_error(self, param.ident.span, err);
2258 seen_bindings.entry(ident).or_insert(param.ident.span);
2260 // Plain insert (no renaming).
2261 let def = Def::TyParam(self.definitions.local_def_id(param.id));
2262 function_type_rib.bindings.insert(ident, def);
2263 self.record_def(param.id, PathResolution::new(def));
2266 self.ribs[TypeNS].push(function_type_rib);
2269 NoTypeParameters => {
2276 if let HasTypeParameters(..) = type_parameters {
2277 self.ribs[TypeNS].pop();
2281 fn with_label_rib<F>(&mut self, f: F)
2282 where F: FnOnce(&mut Resolver)
2284 self.label_ribs.push(Rib::new(NormalRibKind));
2286 self.label_ribs.pop();
2289 fn with_item_rib<F>(&mut self, f: F)
2290 where F: FnOnce(&mut Resolver)
2292 self.ribs[ValueNS].push(Rib::new(ItemRibKind));
2293 self.ribs[TypeNS].push(Rib::new(ItemRibKind));
2295 self.ribs[TypeNS].pop();
2296 self.ribs[ValueNS].pop();
2299 fn with_constant_rib<F>(&mut self, f: F)
2300 where F: FnOnce(&mut Resolver)
2302 self.ribs[ValueNS].push(Rib::new(ConstantItemRibKind));
2304 self.ribs[ValueNS].pop();
2307 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2308 where F: FnOnce(&mut Resolver) -> T
2310 // Handle nested impls (inside fn bodies)
2311 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2312 let result = f(self);
2313 self.current_self_type = previous_value;
2317 /// This is called to resolve a trait reference from an `impl` (i.e. `impl Trait for Foo`)
2318 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
2319 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2321 let mut new_val = None;
2322 let mut new_id = None;
2323 if let Some(trait_ref) = opt_trait_ref {
2324 let path: Vec<_> = trait_ref.path.segments.iter()
2325 .map(|seg| seg.ident)
2327 let def = self.smart_resolve_path_fragment(
2331 trait_ref.path.span,
2332 PathSource::Trait(AliasPossibility::No),
2333 CrateLint::SimplePath(trait_ref.ref_id),
2335 if def != Def::Err {
2336 new_id = Some(def.def_id());
2337 let span = trait_ref.path.span;
2338 if let PathResult::Module(module) = self.resolve_path(
2343 CrateLint::SimplePath(trait_ref.ref_id),
2345 new_val = Some((module, trait_ref.clone()));
2349 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2350 let result = f(self, new_id);
2351 self.current_trait_ref = original_trait_ref;
2355 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2356 where F: FnOnce(&mut Resolver)
2358 let mut self_type_rib = Rib::new(NormalRibKind);
2360 // plain insert (no renaming, types are not currently hygienic....)
2361 self_type_rib.bindings.insert(keywords::SelfType.ident(), self_def);
2362 self.ribs[TypeNS].push(self_type_rib);
2364 self.ribs[TypeNS].pop();
2367 fn resolve_implementation(&mut self,
2368 generics: &Generics,
2369 opt_trait_reference: &Option<TraitRef>,
2372 impl_items: &[ImplItem]) {
2373 // If applicable, create a rib for the type parameters.
2374 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2375 // Dummy self type for better errors if `Self` is used in the trait path.
2376 this.with_self_rib(Def::SelfTy(None, None), |this| {
2377 // Resolve the trait reference, if necessary.
2378 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2379 let item_def_id = this.definitions.local_def_id(item_id);
2380 this.with_self_rib(Def::SelfTy(trait_id, Some(item_def_id)), |this| {
2381 if let Some(trait_ref) = opt_trait_reference.as_ref() {
2382 // Resolve type arguments in trait path
2383 visit::walk_trait_ref(this, trait_ref);
2385 // Resolve the self type.
2386 this.visit_ty(self_type);
2387 // Resolve the type parameters.
2388 this.visit_generics(generics);
2389 this.with_current_self_type(self_type, |this| {
2390 for impl_item in impl_items {
2391 this.check_proc_macro_attrs(&impl_item.attrs);
2392 this.resolve_visibility(&impl_item.vis);
2394 // We also need a new scope for the impl item type parameters.
2395 let type_parameters = HasTypeParameters(&impl_item.generics,
2396 TraitOrImplItemRibKind);
2397 this.with_type_parameter_rib(type_parameters, |this| {
2398 use self::ResolutionError::*;
2399 match impl_item.node {
2400 ImplItemKind::Const(..) => {
2401 // If this is a trait impl, ensure the const
2403 this.check_trait_item(impl_item.ident,
2406 |n, s| ConstNotMemberOfTrait(n, s));
2407 this.with_constant_rib(|this|
2408 visit::walk_impl_item(this, impl_item)
2411 ImplItemKind::Method(..) => {
2412 // If this is a trait impl, ensure the method
2414 this.check_trait_item(impl_item.ident,
2417 |n, s| MethodNotMemberOfTrait(n, s));
2419 visit::walk_impl_item(this, impl_item);
2421 ImplItemKind::Type(ref ty) => {
2422 // If this is a trait impl, ensure the type
2424 this.check_trait_item(impl_item.ident,
2427 |n, s| TypeNotMemberOfTrait(n, s));
2431 ImplItemKind::Macro(_) =>
2432 panic!("unexpanded macro in resolve!"),
2443 fn check_trait_item<F>(&mut self, ident: Ident, ns: Namespace, span: Span, err: F)
2444 where F: FnOnce(Name, &str) -> ResolutionError
2446 // If there is a TraitRef in scope for an impl, then the method must be in the
2448 if let Some((module, _)) = self.current_trait_ref {
2449 if self.resolve_ident_in_module(module, ident, ns, false, false, span).is_err() {
2450 let path = &self.current_trait_ref.as_ref().unwrap().1.path;
2451 resolve_error(self, span, err(ident.name, &path_names_to_string(path)));
2456 fn resolve_local(&mut self, local: &Local) {
2457 // Resolve the type.
2458 walk_list!(self, visit_ty, &local.ty);
2460 // Resolve the initializer.
2461 walk_list!(self, visit_expr, &local.init);
2463 // Resolve the pattern.
2464 self.resolve_pattern(&local.pat, PatternSource::Let, &mut FxHashMap());
2467 // build a map from pattern identifiers to binding-info's.
2468 // this is done hygienically. This could arise for a macro
2469 // that expands into an or-pattern where one 'x' was from the
2470 // user and one 'x' came from the macro.
2471 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2472 let mut binding_map = FxHashMap();
2474 pat.walk(&mut |pat| {
2475 if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node {
2476 if sub_pat.is_some() || match self.def_map.get(&pat.id).map(|res| res.base_def()) {
2477 Some(Def::Local(..)) => true,
2480 let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode };
2481 binding_map.insert(ident, binding_info);
2490 // check that all of the arms in an or-pattern have exactly the
2491 // same set of bindings, with the same binding modes for each.
2492 fn check_consistent_bindings(&mut self, pats: &[P<Pat>]) {
2493 if pats.is_empty() {
2497 let mut missing_vars = FxHashMap();
2498 let mut inconsistent_vars = FxHashMap();
2499 for (i, p) in pats.iter().enumerate() {
2500 let map_i = self.binding_mode_map(&p);
2502 for (j, q) in pats.iter().enumerate() {
2507 let map_j = self.binding_mode_map(&q);
2508 for (&key, &binding_i) in &map_i {
2509 if map_j.len() == 0 { // Account for missing bindings when
2510 let binding_error = missing_vars // map_j has none.
2512 .or_insert(BindingError {
2514 origin: BTreeSet::new(),
2515 target: BTreeSet::new(),
2517 binding_error.origin.insert(binding_i.span);
2518 binding_error.target.insert(q.span);
2520 for (&key_j, &binding_j) in &map_j {
2521 match map_i.get(&key_j) {
2522 None => { // missing binding
2523 let binding_error = missing_vars
2525 .or_insert(BindingError {
2527 origin: BTreeSet::new(),
2528 target: BTreeSet::new(),
2530 binding_error.origin.insert(binding_j.span);
2531 binding_error.target.insert(p.span);
2533 Some(binding_i) => { // check consistent binding
2534 if binding_i.binding_mode != binding_j.binding_mode {
2537 .or_insert((binding_j.span, binding_i.span));
2545 let mut missing_vars = missing_vars.iter().collect::<Vec<_>>();
2546 missing_vars.sort();
2547 for (_, v) in missing_vars {
2549 *v.origin.iter().next().unwrap(),
2550 ResolutionError::VariableNotBoundInPattern(v));
2552 let mut inconsistent_vars = inconsistent_vars.iter().collect::<Vec<_>>();
2553 inconsistent_vars.sort();
2554 for (name, v) in inconsistent_vars {
2555 resolve_error(self, v.0, ResolutionError::VariableBoundWithDifferentMode(*name, v.1));
2559 fn resolve_arm(&mut self, arm: &Arm) {
2560 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2562 let mut bindings_list = FxHashMap();
2563 for pattern in &arm.pats {
2564 self.resolve_pattern(&pattern, PatternSource::Match, &mut bindings_list);
2567 // This has to happen *after* we determine which pat_idents are variants
2568 self.check_consistent_bindings(&arm.pats);
2570 walk_list!(self, visit_expr, &arm.guard);
2571 self.visit_expr(&arm.body);
2573 self.ribs[ValueNS].pop();
2576 fn resolve_block(&mut self, block: &Block) {
2577 debug!("(resolving block) entering block");
2578 // Move down in the graph, if there's an anonymous module rooted here.
2579 let orig_module = self.current_module;
2580 let anonymous_module = self.block_map.get(&block.id).cloned(); // clones a reference
2582 let mut num_macro_definition_ribs = 0;
2583 if let Some(anonymous_module) = anonymous_module {
2584 debug!("(resolving block) found anonymous module, moving down");
2585 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2586 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2587 self.current_module = anonymous_module;
2588 self.finalize_current_module_macro_resolutions();
2590 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2593 // Descend into the block.
2594 for stmt in &block.stmts {
2595 if let ast::StmtKind::Item(ref item) = stmt.node {
2596 if let ast::ItemKind::MacroDef(..) = item.node {
2597 num_macro_definition_ribs += 1;
2598 let def = self.definitions.local_def_id(item.id);
2599 self.ribs[ValueNS].push(Rib::new(MacroDefinition(def)));
2600 self.label_ribs.push(Rib::new(MacroDefinition(def)));
2604 self.visit_stmt(stmt);
2608 self.current_module = orig_module;
2609 for _ in 0 .. num_macro_definition_ribs {
2610 self.ribs[ValueNS].pop();
2611 self.label_ribs.pop();
2613 self.ribs[ValueNS].pop();
2614 if let Some(_) = anonymous_module {
2615 self.ribs[TypeNS].pop();
2617 debug!("(resolving block) leaving block");
2620 fn fresh_binding(&mut self,
2623 outer_pat_id: NodeId,
2624 pat_src: PatternSource,
2625 bindings: &mut FxHashMap<Ident, NodeId>)
2627 // Add the binding to the local ribs, if it
2628 // doesn't already exist in the bindings map. (We
2629 // must not add it if it's in the bindings map
2630 // because that breaks the assumptions later
2631 // passes make about or-patterns.)
2632 let mut def = Def::Local(pat_id);
2633 match bindings.get(&ident).cloned() {
2634 Some(id) if id == outer_pat_id => {
2635 // `Variant(a, a)`, error
2639 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2643 Some(..) if pat_src == PatternSource::FnParam => {
2644 // `fn f(a: u8, a: u8)`, error
2648 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2652 Some(..) if pat_src == PatternSource::Match ||
2653 pat_src == PatternSource::IfLet ||
2654 pat_src == PatternSource::WhileLet => {
2655 // `Variant1(a) | Variant2(a)`, ok
2656 // Reuse definition from the first `a`.
2657 def = self.ribs[ValueNS].last_mut().unwrap().bindings[&ident];
2660 span_bug!(ident.span, "two bindings with the same name from \
2661 unexpected pattern source {:?}", pat_src);
2664 // A completely fresh binding, add to the lists if it's valid.
2665 if ident.name != keywords::Invalid.name() {
2666 bindings.insert(ident, outer_pat_id);
2667 self.ribs[ValueNS].last_mut().unwrap().bindings.insert(ident, def);
2672 PathResolution::new(def)
2675 fn resolve_pattern(&mut self,
2677 pat_src: PatternSource,
2678 // Maps idents to the node ID for the
2679 // outermost pattern that binds them.
2680 bindings: &mut FxHashMap<Ident, NodeId>) {
2681 // Visit all direct subpatterns of this pattern.
2682 let outer_pat_id = pat.id;
2683 pat.walk(&mut |pat| {
2685 PatKind::Ident(bmode, ident, ref opt_pat) => {
2686 // First try to resolve the identifier as some existing
2687 // entity, then fall back to a fresh binding.
2688 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS,
2690 .and_then(LexicalScopeBinding::item);
2691 let resolution = binding.map(NameBinding::def).and_then(|def| {
2692 let is_syntactic_ambiguity = opt_pat.is_none() &&
2693 bmode == BindingMode::ByValue(Mutability::Immutable);
2695 Def::StructCtor(_, CtorKind::Const) |
2696 Def::VariantCtor(_, CtorKind::Const) |
2697 Def::Const(..) if is_syntactic_ambiguity => {
2698 // Disambiguate in favor of a unit struct/variant
2699 // or constant pattern.
2700 self.record_use(ident, ValueNS, binding.unwrap(), ident.span);
2701 Some(PathResolution::new(def))
2703 Def::StructCtor(..) | Def::VariantCtor(..) |
2704 Def::Const(..) | Def::Static(..) => {
2705 // This is unambiguously a fresh binding, either syntactically
2706 // (e.g. `IDENT @ PAT` or `ref IDENT`) or because `IDENT` resolves
2707 // to something unusable as a pattern (e.g. constructor function),
2708 // but we still conservatively report an error, see
2709 // issues/33118#issuecomment-233962221 for one reason why.
2713 ResolutionError::BindingShadowsSomethingUnacceptable(
2714 pat_src.descr(), ident.name, binding.unwrap())
2718 Def::Fn(..) | Def::Err => {
2719 // These entities are explicitly allowed
2720 // to be shadowed by fresh bindings.
2724 span_bug!(ident.span, "unexpected definition for an \
2725 identifier in pattern: {:?}", def);
2728 }).unwrap_or_else(|| {
2729 self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings)
2732 self.record_def(pat.id, resolution);
2735 PatKind::TupleStruct(ref path, ..) => {
2736 self.smart_resolve_path(pat.id, None, path, PathSource::TupleStruct);
2739 PatKind::Path(ref qself, ref path) => {
2740 self.smart_resolve_path(pat.id, qself.as_ref(), path, PathSource::Pat);
2743 PatKind::Struct(ref path, ..) => {
2744 self.smart_resolve_path(pat.id, None, path, PathSource::Struct);
2752 visit::walk_pat(self, pat);
2755 // High-level and context dependent path resolution routine.
2756 // Resolves the path and records the resolution into definition map.
2757 // If resolution fails tries several techniques to find likely
2758 // resolution candidates, suggest imports or other help, and report
2759 // errors in user friendly way.
2760 fn smart_resolve_path(&mut self,
2762 qself: Option<&QSelf>,
2766 self.smart_resolve_path_with_crate_lint(id, qself, path, source, CrateLint::SimplePath(id))
2769 /// A variant of `smart_resolve_path` where you also specify extra
2770 /// information about where the path came from; this extra info is
2771 /// sometimes needed for the lint that recommends rewriting
2772 /// absoluate paths to `crate`, so that it knows how to frame the
2773 /// suggestion. If you are just resolving a path like `foo::bar`
2774 /// that appears...somewhere, though, then you just want
2775 /// `CrateLint::SimplePath`, which is what `smart_resolve_path`
2776 /// already provides.
2777 fn smart_resolve_path_with_crate_lint(
2780 qself: Option<&QSelf>,
2783 crate_lint: CrateLint
2784 ) -> PathResolution {
2785 let segments = &path.segments.iter()
2786 .map(|seg| seg.ident)
2787 .collect::<Vec<_>>();
2788 self.smart_resolve_path_fragment(id, qself, segments, path.span, source, crate_lint)
2791 fn smart_resolve_path_fragment(&mut self,
2793 qself: Option<&QSelf>,
2797 crate_lint: CrateLint)
2799 let ident_span = path.last().map_or(span, |ident| ident.span);
2800 let ns = source.namespace();
2801 let is_expected = &|def| source.is_expected(def);
2802 let is_enum_variant = &|def| if let Def::Variant(..) = def { true } else { false };
2804 // Base error is amended with one short label and possibly some longer helps/notes.
2805 let report_errors = |this: &mut Self, def: Option<Def>| {
2806 // Make the base error.
2807 let expected = source.descr_expected();
2808 let path_str = names_to_string(path);
2809 let code = source.error_code(def.is_some());
2810 let (base_msg, fallback_label, base_span) = if let Some(def) = def {
2811 (format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str),
2812 format!("not a {}", expected),
2815 let item_str = path[path.len() - 1];
2816 let item_span = path[path.len() - 1].span;
2817 let (mod_prefix, mod_str) = if path.len() == 1 {
2818 (format!(""), format!("this scope"))
2819 } else if path.len() == 2 && path[0].name == keywords::CrateRoot.name() {
2820 (format!(""), format!("the crate root"))
2822 let mod_path = &path[..path.len() - 1];
2823 let mod_prefix = match this.resolve_path(mod_path, Some(TypeNS),
2824 false, span, CrateLint::No) {
2825 PathResult::Module(module) => module.def(),
2827 }.map_or(format!(""), |def| format!("{} ", def.kind_name()));
2828 (mod_prefix, format!("`{}`", names_to_string(mod_path)))
2830 (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str),
2831 format!("not found in {}", mod_str),
2834 let code = DiagnosticId::Error(code.into());
2835 let mut err = this.session.struct_span_err_with_code(base_span, &base_msg, code);
2837 // Emit special messages for unresolved `Self` and `self`.
2838 if is_self_type(path, ns) {
2839 __diagnostic_used!(E0411);
2840 err.code(DiagnosticId::Error("E0411".into()));
2841 err.span_label(span, "`Self` is only available in traits and impls");
2842 return (err, Vec::new());
2844 if is_self_value(path, ns) {
2845 __diagnostic_used!(E0424);
2846 err.code(DiagnosticId::Error("E0424".into()));
2847 err.span_label(span, format!("`self` value is only available in \
2848 methods with `self` parameter"));
2849 return (err, Vec::new());
2852 // Try to lookup the name in more relaxed fashion for better error reporting.
2853 let ident = *path.last().unwrap();
2854 let candidates = this.lookup_import_candidates(ident.name, ns, is_expected);
2855 if candidates.is_empty() && is_expected(Def::Enum(DefId::local(CRATE_DEF_INDEX))) {
2856 let enum_candidates =
2857 this.lookup_import_candidates(ident.name, ns, is_enum_variant);
2858 let mut enum_candidates = enum_candidates.iter()
2859 .map(|suggestion| import_candidate_to_paths(&suggestion)).collect::<Vec<_>>();
2860 enum_candidates.sort();
2861 for (sp, variant_path, enum_path) in enum_candidates {
2863 let msg = format!("there is an enum variant `{}`, \
2869 err.span_suggestion(span, "you can try using the variant's enum",
2874 if path.len() == 1 && this.self_type_is_available(span) {
2875 if let Some(candidate) = this.lookup_assoc_candidate(ident, ns, is_expected) {
2876 let self_is_available = this.self_value_is_available(path[0].span, span);
2878 AssocSuggestion::Field => {
2879 err.span_suggestion(span, "try",
2880 format!("self.{}", path_str));
2881 if !self_is_available {
2882 err.span_label(span, format!("`self` value is only available in \
2883 methods with `self` parameter"));
2886 AssocSuggestion::MethodWithSelf if self_is_available => {
2887 err.span_suggestion(span, "try",
2888 format!("self.{}", path_str));
2890 AssocSuggestion::MethodWithSelf | AssocSuggestion::AssocItem => {
2891 err.span_suggestion(span, "try",
2892 format!("Self::{}", path_str));
2895 return (err, candidates);
2899 let mut levenshtein_worked = false;
2902 if let Some(candidate) = this.lookup_typo_candidate(path, ns, is_expected, span) {
2903 err.span_label(ident_span, format!("did you mean `{}`?", candidate));
2904 levenshtein_worked = true;
2907 // Try context dependent help if relaxed lookup didn't work.
2908 if let Some(def) = def {
2909 match (def, source) {
2910 (Def::Macro(..), _) => {
2911 err.span_label(span, format!("did you mean `{}!(...)`?", path_str));
2912 return (err, candidates);
2914 (Def::TyAlias(..), PathSource::Trait(_)) => {
2915 err.span_label(span, "type aliases cannot be used for traits");
2916 return (err, candidates);
2918 (Def::Mod(..), PathSource::Expr(Some(parent))) => match parent.node {
2919 ExprKind::Field(_, ident) => {
2920 err.span_label(parent.span, format!("did you mean `{}::{}`?",
2922 return (err, candidates);
2924 ExprKind::MethodCall(ref segment, ..) => {
2925 err.span_label(parent.span, format!("did you mean `{}::{}(...)`?",
2926 path_str, segment.ident));
2927 return (err, candidates);
2931 (Def::Enum(..), PathSource::TupleStruct)
2932 | (Def::Enum(..), PathSource::Expr(..)) => {
2933 if let Some(variants) = this.collect_enum_variants(def) {
2934 err.note(&format!("did you mean to use one \
2935 of the following variants?\n{}",
2937 .map(|suggestion| path_names_to_string(suggestion))
2938 .map(|suggestion| format!("- `{}`", suggestion))
2939 .collect::<Vec<_>>()
2943 err.note("did you mean to use one of the enum's variants?");
2945 return (err, candidates);
2947 (Def::Struct(def_id), _) if ns == ValueNS => {
2948 if let Some((ctor_def, ctor_vis))
2949 = this.struct_constructors.get(&def_id).cloned() {
2950 let accessible_ctor = this.is_accessible(ctor_vis);
2951 if is_expected(ctor_def) && !accessible_ctor {
2952 err.span_label(span, format!("constructor is not visible \
2953 here due to private fields"));
2956 // HACK(estebank): find a better way to figure out that this was a
2957 // parser issue where a struct literal is being used on an expression
2958 // where a brace being opened means a block is being started. Look
2959 // ahead for the next text to see if `span` is followed by a `{`.
2960 let cm = this.session.codemap();
2963 sp = cm.next_point(sp);
2964 match cm.span_to_snippet(sp) {
2965 Ok(ref snippet) => {
2966 if snippet.chars().any(|c| { !c.is_whitespace() }) {
2973 let followed_by_brace = match cm.span_to_snippet(sp) {
2974 Ok(ref snippet) if snippet == "{" => true,
2977 if let (PathSource::Expr(None), true) = (source, followed_by_brace) {
2980 format!("did you mean `({} {{ /* fields */ }})`?", path_str),
2985 format!("did you mean `{} {{ /* fields */ }}`?", path_str),
2989 return (err, candidates);
2991 (Def::Union(..), _) |
2992 (Def::Variant(..), _) |
2993 (Def::VariantCtor(_, CtorKind::Fictive), _) if ns == ValueNS => {
2994 err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?",
2996 return (err, candidates);
2998 (Def::SelfTy(..), _) if ns == ValueNS => {
2999 err.span_label(span, fallback_label);
3000 err.note("can't use `Self` as a constructor, you must use the \
3001 implemented struct");
3002 return (err, candidates);
3004 (Def::TyAlias(_), _) | (Def::AssociatedTy(..), _) if ns == ValueNS => {
3005 err.note("can't use a type alias as a constructor");
3006 return (err, candidates);
3013 if !levenshtein_worked {
3014 err.span_label(base_span, fallback_label);
3015 this.type_ascription_suggestion(&mut err, base_span);
3019 let report_errors = |this: &mut Self, def: Option<Def>| {
3020 let (err, candidates) = report_errors(this, def);
3021 let def_id = this.current_module.normal_ancestor_id;
3022 let node_id = this.definitions.as_local_node_id(def_id).unwrap();
3023 let better = def.is_some();
3024 this.use_injections.push(UseError { err, candidates, node_id, better });
3025 err_path_resolution()
3028 let resolution = match self.resolve_qpath_anywhere(
3034 source.defer_to_typeck(),
3035 source.global_by_default(),
3038 Some(resolution) if resolution.unresolved_segments() == 0 => {
3039 if is_expected(resolution.base_def()) || resolution.base_def() == Def::Err {
3042 // Add a temporary hack to smooth the transition to new struct ctor
3043 // visibility rules. See #38932 for more details.
3045 if let Def::Struct(def_id) = resolution.base_def() {
3046 if let Some((ctor_def, ctor_vis))
3047 = self.struct_constructors.get(&def_id).cloned() {
3048 if is_expected(ctor_def) && self.is_accessible(ctor_vis) {
3049 let lint = lint::builtin::LEGACY_CONSTRUCTOR_VISIBILITY;
3050 self.session.buffer_lint(lint, id, span,
3051 "private struct constructors are not usable through \
3052 re-exports in outer modules",
3054 res = Some(PathResolution::new(ctor_def));
3059 res.unwrap_or_else(|| report_errors(self, Some(resolution.base_def())))
3062 Some(resolution) if source.defer_to_typeck() => {
3063 // Not fully resolved associated item `T::A::B` or `<T as Tr>::A::B`
3064 // or `<T>::A::B`. If `B` should be resolved in value namespace then
3065 // it needs to be added to the trait map.
3067 let item_name = *path.last().unwrap();
3068 let traits = self.get_traits_containing_item(item_name, ns);
3069 self.trait_map.insert(id, traits);
3073 _ => report_errors(self, None)
3076 if let PathSource::TraitItem(..) = source {} else {
3077 // Avoid recording definition of `A::B` in `<T as A>::B::C`.
3078 self.record_def(id, resolution);
3083 fn type_ascription_suggestion(&self,
3084 err: &mut DiagnosticBuilder,
3086 debug!("type_ascription_suggetion {:?}", base_span);
3087 let cm = self.session.codemap();
3088 debug!("self.current_type_ascription {:?}", self.current_type_ascription);
3089 if let Some(sp) = self.current_type_ascription.last() {
3091 loop { // try to find the `:`, bail on first non-':'/non-whitespace
3092 sp = cm.next_point(sp);
3093 if let Ok(snippet) = cm.span_to_snippet(sp.to(cm.next_point(sp))) {
3094 debug!("snippet {:?}", snippet);
3095 let line_sp = cm.lookup_char_pos(sp.hi()).line;
3096 let line_base_sp = cm.lookup_char_pos(base_span.lo()).line;
3097 debug!("{:?} {:?}", line_sp, line_base_sp);
3099 err.span_label(base_span,
3100 "expecting a type here because of type ascription");
3101 if line_sp != line_base_sp {
3102 err.span_suggestion_short(sp,
3103 "did you mean to use `;` here instead?",
3107 } else if snippet.trim().len() != 0 {
3108 debug!("tried to find type ascription `:` token, couldn't find it");
3118 fn self_type_is_available(&mut self, span: Span) -> bool {
3119 let binding = self.resolve_ident_in_lexical_scope(keywords::SelfType.ident(),
3120 TypeNS, false, span);
3121 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
3124 fn self_value_is_available(&mut self, self_span: Span, path_span: Span) -> bool {
3125 let ident = Ident::new(keywords::SelfValue.name(), self_span);
3126 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, false, path_span);
3127 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
3130 // Resolve in alternative namespaces if resolution in the primary namespace fails.
3131 fn resolve_qpath_anywhere(&mut self,
3133 qself: Option<&QSelf>,
3135 primary_ns: Namespace,
3137 defer_to_typeck: bool,
3138 global_by_default: bool,
3139 crate_lint: CrateLint)
3140 -> Option<PathResolution> {
3141 let mut fin_res = None;
3142 // FIXME: can't resolve paths in macro namespace yet, macros are
3143 // processed by the little special hack below.
3144 for (i, ns) in [primary_ns, TypeNS, ValueNS, /*MacroNS*/].iter().cloned().enumerate() {
3145 if i == 0 || ns != primary_ns {
3146 match self.resolve_qpath(id, qself, path, ns, span, global_by_default, crate_lint) {
3147 // If defer_to_typeck, then resolution > no resolution,
3148 // otherwise full resolution > partial resolution > no resolution.
3149 Some(res) if res.unresolved_segments() == 0 || defer_to_typeck =>
3151 res => if fin_res.is_none() { fin_res = res },
3155 let is_global = self.global_macros.get(&path[0].name).cloned()
3156 .map(|binding| binding.get_macro(self).kind() == MacroKind::Bang).unwrap_or(false);
3157 if primary_ns != MacroNS && (is_global ||
3158 self.macro_names.contains(&path[0].modern())) {
3159 // Return some dummy definition, it's enough for error reporting.
3161 PathResolution::new(Def::Macro(DefId::local(CRATE_DEF_INDEX), MacroKind::Bang))
3167 /// Handles paths that may refer to associated items.
3168 fn resolve_qpath(&mut self,
3170 qself: Option<&QSelf>,
3174 global_by_default: bool,
3175 crate_lint: CrateLint)
3176 -> Option<PathResolution> {
3178 "resolve_qpath(id={:?}, qself={:?}, path={:?}, \
3179 ns={:?}, span={:?}, global_by_default={:?})",
3188 if let Some(qself) = qself {
3189 if qself.position == 0 {
3190 // This is a case like `<T>::B`, where there is no
3191 // trait to resolve. In that case, we leave the `B`
3192 // segment to be resolved by type-check.
3193 return Some(PathResolution::with_unresolved_segments(
3194 Def::Mod(DefId::local(CRATE_DEF_INDEX)), path.len()
3198 // Make sure `A::B` in `<T as A::B>::C` is a trait item.
3200 // Currently, `path` names the full item (`A::B::C`, in
3201 // our example). so we extract the prefix of that that is
3202 // the trait (the slice upto and including
3203 // `qself.position`). And then we recursively resolve that,
3204 // but with `qself` set to `None`.
3206 // However, setting `qself` to none (but not changing the
3207 // span) loses the information about where this path
3208 // *actually* appears, so for the purposes of the crate
3209 // lint we pass along information that this is the trait
3210 // name from a fully qualified path, and this also
3211 // contains the full span (the `CrateLint::QPathTrait`).
3212 let ns = if qself.position + 1 == path.len() { ns } else { TypeNS };
3213 let res = self.smart_resolve_path_fragment(
3216 &path[..qself.position + 1],
3218 PathSource::TraitItem(ns),
3219 CrateLint::QPathTrait {
3221 qpath_span: qself.path_span,
3225 // The remaining segments (the `C` in our example) will
3226 // have to be resolved by type-check, since that requires doing
3227 // trait resolution.
3228 return Some(PathResolution::with_unresolved_segments(
3229 res.base_def(), res.unresolved_segments() + path.len() - qself.position - 1
3233 let result = match self.resolve_path(
3240 PathResult::NonModule(path_res) => path_res,
3241 PathResult::Module(module) if !module.is_normal() => {
3242 PathResolution::new(module.def().unwrap())
3244 // In `a(::assoc_item)*` `a` cannot be a module. If `a` does resolve to a module we
3245 // don't report an error right away, but try to fallback to a primitive type.
3246 // So, we are still able to successfully resolve something like
3248 // use std::u8; // bring module u8 in scope
3249 // fn f() -> u8 { // OK, resolves to primitive u8, not to std::u8
3250 // u8::max_value() // OK, resolves to associated function <u8>::max_value,
3251 // // not to non-existent std::u8::max_value
3254 // Such behavior is required for backward compatibility.
3255 // The same fallback is used when `a` resolves to nothing.
3256 PathResult::Module(..) | PathResult::Failed(..)
3257 if (ns == TypeNS || path.len() > 1) &&
3258 self.primitive_type_table.primitive_types
3259 .contains_key(&path[0].name) => {
3260 let prim = self.primitive_type_table.primitive_types[&path[0].name];
3261 PathResolution::with_unresolved_segments(Def::PrimTy(prim), path.len() - 1)
3263 PathResult::Module(module) => PathResolution::new(module.def().unwrap()),
3264 PathResult::Failed(span, msg, false) => {
3265 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
3266 err_path_resolution()
3268 PathResult::Failed(..) => return None,
3269 PathResult::Indeterminate => bug!("indetermined path result in resolve_qpath"),
3272 if path.len() > 1 && !global_by_default && result.base_def() != Def::Err &&
3273 path[0].name != keywords::CrateRoot.name() &&
3274 path[0].name != keywords::DollarCrate.name() {
3275 let unqualified_result = {
3276 match self.resolve_path(
3277 &[*path.last().unwrap()],
3283 PathResult::NonModule(path_res) => path_res.base_def(),
3284 PathResult::Module(module) => module.def().unwrap(),
3285 _ => return Some(result),
3288 if result.base_def() == unqualified_result {
3289 let lint = lint::builtin::UNUSED_QUALIFICATIONS;
3290 self.session.buffer_lint(lint, id, span, "unnecessary qualification")
3300 opt_ns: Option<Namespace>, // `None` indicates a module path
3303 crate_lint: CrateLint,
3304 ) -> PathResult<'a> {
3305 let mut module = None;
3306 let mut allow_super = true;
3307 let mut second_binding = None;
3310 "resolve_path(path={:?}, opt_ns={:?}, record_used={:?}, \
3311 path_span={:?}, crate_lint={:?})",
3319 for (i, &ident) in path.iter().enumerate() {
3320 debug!("resolve_path ident {} {:?}", i, ident);
3321 let is_last = i == path.len() - 1;
3322 let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
3323 let name = ident.name;
3325 if i == 0 && ns == TypeNS && name == keywords::SelfValue.name() {
3326 let mut ctxt = ident.span.ctxt().modern();
3327 module = Some(self.resolve_self(&mut ctxt, self.current_module));
3329 } else if allow_super && ns == TypeNS && name == keywords::Super.name() {
3330 let mut ctxt = ident.span.ctxt().modern();
3331 let self_module = match i {
3332 0 => self.resolve_self(&mut ctxt, self.current_module),
3333 _ => module.unwrap(),
3335 if let Some(parent) = self_module.parent {
3336 module = Some(self.resolve_self(&mut ctxt, parent));
3339 let msg = "There are too many initial `super`s.".to_string();
3340 return PathResult::Failed(ident.span, msg, false);
3342 } else if i == 0 && ns == TypeNS && name == keywords::Extern.name() {
3345 allow_super = false;
3348 if (i == 0 && name == keywords::CrateRoot.name()) ||
3349 (i == 0 && name == keywords::Crate.name()) ||
3350 (i == 1 && name == keywords::Crate.name() &&
3351 path[0].name == keywords::CrateRoot.name()) {
3352 // `::a::b` or `::crate::a::b`
3353 module = Some(self.resolve_crate_root(ident.span.ctxt(), false));
3355 } else if i == 0 && name == keywords::DollarCrate.name() {
3357 module = Some(self.resolve_crate_root(ident.span.ctxt(), true));
3359 } else if i == 1 && !ident.is_path_segment_keyword() {
3360 let prev_name = path[0].name;
3361 if prev_name == keywords::Extern.name() ||
3362 prev_name == keywords::CrateRoot.name() &&
3363 self.session.features_untracked().extern_absolute_paths &&
3364 self.session.rust_2018() {
3365 // `::extern_crate::a::b`
3366 let crate_id = self.crate_loader.process_path_extern(name, ident.span);
3368 self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
3369 self.populate_module_if_necessary(crate_root);
3370 module = Some(crate_root);
3376 // Report special messages for path segment keywords in wrong positions.
3377 if name == keywords::CrateRoot.name() && i != 0 ||
3378 name == keywords::DollarCrate.name() && i != 0 ||
3379 name == keywords::SelfValue.name() && i != 0 ||
3380 name == keywords::SelfType.name() && i != 0 ||
3381 name == keywords::Super.name() && i != 0 ||
3382 name == keywords::Extern.name() && i != 0 ||
3383 // we allow crate::foo and ::crate::foo but nothing else
3384 name == keywords::Crate.name() && i > 1 &&
3385 path[0].name != keywords::CrateRoot.name() ||
3386 name == keywords::Crate.name() && path.len() == 1 {
3387 let name_str = if name == keywords::CrateRoot.name() {
3388 format!("crate root")
3390 format!("`{}`", name)
3392 let msg = if i == 1 && path[0].name == keywords::CrateRoot.name() {
3393 format!("global paths cannot start with {}", name_str)
3395 format!("{} in paths can only be used in start position", name_str)
3397 return PathResult::Failed(ident.span, msg, false);
3400 let binding = if let Some(module) = module {
3401 self.resolve_ident_in_module(module, ident, ns, false, record_used, path_span)
3402 } else if opt_ns == Some(MacroNS) {
3403 self.resolve_lexical_macro_path_segment(ident, ns, record_used, path_span)
3404 .map(MacroBinding::binding)
3406 match self.resolve_ident_in_lexical_scope(ident, ns, record_used, path_span) {
3407 // we found a locally-imported or available item/module
3408 Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
3409 // we found a local variable or type param
3410 Some(LexicalScopeBinding::Def(def))
3411 if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) => {
3412 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3416 _ => Err(if record_used { Determined } else { Undetermined }),
3423 second_binding = Some(binding);
3425 let def = binding.def();
3426 let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(def);
3427 if let Some(next_module) = binding.module() {
3428 module = Some(next_module);
3429 } else if def == Def::Err {
3430 return PathResult::NonModule(err_path_resolution());
3431 } else if opt_ns.is_some() && (is_last || maybe_assoc) {
3432 self.lint_if_path_starts_with_module(
3438 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3439 def, path.len() - i - 1
3442 return PathResult::Failed(ident.span,
3443 format!("Not a module `{}`", ident),
3447 Err(Undetermined) => return PathResult::Indeterminate,
3448 Err(Determined) => {
3449 if let Some(module) = module {
3450 if opt_ns.is_some() && !module.is_normal() {
3451 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3452 module.def().unwrap(), path.len() - i
3456 let msg = if module.and_then(ModuleData::def) == self.graph_root.def() {
3457 let is_mod = |def| match def { Def::Mod(..) => true, _ => false };
3458 let mut candidates =
3459 self.lookup_import_candidates(name, TypeNS, is_mod);
3460 candidates.sort_by_cached_key(|c| {
3461 (c.path.segments.len(), c.path.to_string())
3463 if let Some(candidate) = candidates.get(0) {
3464 format!("Did you mean `{}`?", candidate.path)
3466 format!("Maybe a missing `extern crate {};`?", ident)
3469 format!("Use of undeclared type or module `{}`", ident)
3471 format!("Could not find `{}` in `{}`", ident, path[i - 1])
3473 return PathResult::Failed(ident.span, msg, is_last);
3478 self.lint_if_path_starts_with_module(crate_lint, path, path_span, second_binding);
3480 PathResult::Module(module.unwrap_or(self.graph_root))
3483 fn lint_if_path_starts_with_module(
3485 crate_lint: CrateLint,
3488 second_binding: Option<&NameBinding>,
3490 let (diag_id, diag_span) = match crate_lint {
3491 CrateLint::No => return,
3492 CrateLint::SimplePath(id) => (id, path_span),
3493 CrateLint::UsePath { root_id, root_span } => (root_id, root_span),
3494 CrateLint::QPathTrait { qpath_id, qpath_span } => (qpath_id, qpath_span),
3497 let first_name = match path.get(0) {
3498 Some(ident) => ident.name,
3502 // We're only interested in `use` paths which should start with
3503 // `{{root}}` or `extern` currently.
3504 if first_name != keywords::Extern.name() && first_name != keywords::CrateRoot.name() {
3509 // If this import looks like `crate::...` it's already good
3510 Some(name) if name.name == keywords::Crate.name() => return,
3511 // Otherwise go below to see if it's an extern crate
3513 // If the path has length one (and it's `CrateRoot` most likely)
3514 // then we don't know whether we're gonna be importing a crate or an
3515 // item in our crate. Defer this lint to elsewhere
3519 // If the first element of our path was actually resolved to an
3520 // `ExternCrate` (also used for `crate::...`) then no need to issue a
3521 // warning, this looks all good!
3522 if let Some(binding) = second_binding {
3523 if let NameBindingKind::Import { directive: d, .. } = binding.kind {
3524 // Careful: we still want to rewrite paths from
3525 // renamed extern crates.
3526 if let ImportDirectiveSubclass::ExternCrate(None) = d.subclass {
3532 self.lint_path_starts_with_module(diag_id, diag_span);
3535 fn lint_path_starts_with_module(&self, id: NodeId, span: Span) {
3536 // In the 2018 edition this lint is a hard error, so nothing to do
3537 if self.session.rust_2018() {
3540 // In the 2015 edition there's no use in emitting lints unless the
3541 // crate's already enabled the feature that we're going to suggest
3542 if !self.session.features_untracked().crate_in_paths {
3545 let diag = lint::builtin::BuiltinLintDiagnostics
3546 ::AbsPathWithModule(span);
3547 self.session.buffer_lint_with_diagnostic(
3548 lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
3550 "absolute paths must start with `self`, `super`, \
3551 `crate`, or an external crate name in the 2018 edition",
3555 // Resolve a local definition, potentially adjusting for closures.
3556 fn adjust_local_def(&mut self,
3561 span: Span) -> Def {
3562 let ribs = &self.ribs[ns][rib_index + 1..];
3564 // An invalid forward use of a type parameter from a previous default.
3565 if let ForwardTyParamBanRibKind = self.ribs[ns][rib_index].kind {
3567 resolve_error(self, span, ResolutionError::ForwardDeclaredTyParam);
3569 assert_eq!(def, Def::Err);
3575 span_bug!(span, "unexpected {:?} in bindings", def)
3577 Def::Local(node_id) => {
3580 NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) |
3581 ForwardTyParamBanRibKind => {
3582 // Nothing to do. Continue.
3584 ClosureRibKind(function_id) => {
3587 let seen = self.freevars_seen
3589 .or_insert_with(|| NodeMap());
3590 if let Some(&index) = seen.get(&node_id) {
3591 def = Def::Upvar(node_id, index, function_id);
3594 let vec = self.freevars
3596 .or_insert_with(|| vec![]);
3597 let depth = vec.len();
3598 def = Def::Upvar(node_id, depth, function_id);
3605 seen.insert(node_id, depth);
3608 ItemRibKind | TraitOrImplItemRibKind => {
3609 // This was an attempt to access an upvar inside a
3610 // named function item. This is not allowed, so we
3613 resolve_error(self, span,
3614 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
3618 ConstantItemRibKind => {
3619 // Still doesn't deal with upvars
3621 resolve_error(self, span,
3622 ResolutionError::AttemptToUseNonConstantValueInConstant);
3629 Def::TyParam(..) | Def::SelfTy(..) => {
3632 NormalRibKind | TraitOrImplItemRibKind | ClosureRibKind(..) |
3633 ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind |
3634 ConstantItemRibKind => {
3635 // Nothing to do. Continue.
3638 // This was an attempt to use a type parameter outside
3641 resolve_error(self, span,
3642 ResolutionError::TypeParametersFromOuterFunction(def));
3654 fn lookup_assoc_candidate<FilterFn>(&mut self,
3657 filter_fn: FilterFn)
3658 -> Option<AssocSuggestion>
3659 where FilterFn: Fn(Def) -> bool
3661 fn extract_node_id(t: &Ty) -> Option<NodeId> {
3663 TyKind::Path(None, _) => Some(t.id),
3664 TyKind::Rptr(_, ref mut_ty) => extract_node_id(&mut_ty.ty),
3665 // This doesn't handle the remaining `Ty` variants as they are not
3666 // that commonly the self_type, it might be interesting to provide
3667 // support for those in future.
3672 // Fields are generally expected in the same contexts as locals.
3673 if filter_fn(Def::Local(ast::DUMMY_NODE_ID)) {
3674 if let Some(node_id) = self.current_self_type.as_ref().and_then(extract_node_id) {
3675 // Look for a field with the same name in the current self_type.
3676 if let Some(resolution) = self.def_map.get(&node_id) {
3677 match resolution.base_def() {
3678 Def::Struct(did) | Def::Union(did)
3679 if resolution.unresolved_segments() == 0 => {
3680 if let Some(field_names) = self.field_names.get(&did) {
3681 if field_names.iter().any(|&field_name| ident.name == field_name) {
3682 return Some(AssocSuggestion::Field);
3692 // Look for associated items in the current trait.
3693 if let Some((module, _)) = self.current_trait_ref {
3694 if let Ok(binding) =
3695 self.resolve_ident_in_module(module, ident, ns, false, false, module.span) {
3696 let def = binding.def();
3698 return Some(if self.has_self.contains(&def.def_id()) {
3699 AssocSuggestion::MethodWithSelf
3701 AssocSuggestion::AssocItem
3710 fn lookup_typo_candidate<FilterFn>(&mut self,
3713 filter_fn: FilterFn,
3716 where FilterFn: Fn(Def) -> bool
3718 let add_module_candidates = |module: Module, names: &mut Vec<Name>| {
3719 for (&(ident, _), resolution) in module.resolutions.borrow().iter() {
3720 if let Some(binding) = resolution.borrow().binding {
3721 if filter_fn(binding.def()) {
3722 names.push(ident.name);
3728 let mut names = Vec::new();
3729 if path.len() == 1 {
3730 // Search in lexical scope.
3731 // Walk backwards up the ribs in scope and collect candidates.
3732 for rib in self.ribs[ns].iter().rev() {
3733 // Locals and type parameters
3734 for (ident, def) in &rib.bindings {
3735 if filter_fn(*def) {
3736 names.push(ident.name);
3740 if let ModuleRibKind(module) = rib.kind {
3741 // Items from this module
3742 add_module_candidates(module, &mut names);
3744 if let ModuleKind::Block(..) = module.kind {
3745 // We can see through blocks
3747 // Items from the prelude
3748 if !module.no_implicit_prelude {
3749 names.extend(self.extern_prelude.iter().cloned());
3750 if let Some(prelude) = self.prelude {
3751 add_module_candidates(prelude, &mut names);
3758 // Add primitive types to the mix
3759 if filter_fn(Def::PrimTy(TyBool)) {
3760 for (name, _) in &self.primitive_type_table.primitive_types {
3765 // Search in module.
3766 let mod_path = &path[..path.len() - 1];
3767 if let PathResult::Module(module) = self.resolve_path(mod_path, Some(TypeNS),
3768 false, span, CrateLint::No) {
3769 add_module_candidates(module, &mut names);
3773 let name = path[path.len() - 1].name;
3774 // Make sure error reporting is deterministic.
3775 names.sort_by_cached_key(|name| name.as_str());
3776 match find_best_match_for_name(names.iter(), &name.as_str(), None) {
3777 Some(found) if found != name => Some(found),
3782 fn with_resolved_label<F>(&mut self, label: Option<Label>, id: NodeId, f: F)
3783 where F: FnOnce(&mut Resolver)
3785 if let Some(label) = label {
3786 self.unused_labels.insert(id, label.ident.span);
3787 let def = Def::Label(id);
3788 self.with_label_rib(|this| {
3789 this.label_ribs.last_mut().unwrap().bindings.insert(label.ident, def);
3797 fn resolve_labeled_block(&mut self, label: Option<Label>, id: NodeId, block: &Block) {
3798 self.with_resolved_label(label, id, |this| this.visit_block(block));
3801 fn resolve_expr(&mut self, expr: &Expr, parent: Option<&Expr>) {
3802 // First, record candidate traits for this expression if it could
3803 // result in the invocation of a method call.
3805 self.record_candidate_traits_for_expr_if_necessary(expr);
3807 // Next, resolve the node.
3809 ExprKind::Path(ref qself, ref path) => {
3810 self.smart_resolve_path(expr.id, qself.as_ref(), path, PathSource::Expr(parent));
3811 visit::walk_expr(self, expr);
3814 ExprKind::Struct(ref path, ..) => {
3815 self.smart_resolve_path(expr.id, None, path, PathSource::Struct);
3816 visit::walk_expr(self, expr);
3819 ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => {
3820 match self.search_label(label.ident, |rib, id| rib.bindings.get(&id).cloned()) {
3822 // Search again for close matches...
3823 // Picks the first label that is "close enough", which is not necessarily
3824 // the closest match
3825 let close_match = self.search_label(label.ident, |rib, ident| {
3826 let names = rib.bindings.iter().map(|(id, _)| &id.name);
3827 find_best_match_for_name(names, &*ident.as_str(), None)
3829 self.record_def(expr.id, err_path_resolution());
3832 ResolutionError::UndeclaredLabel(&label.ident.as_str(),
3835 Some(Def::Label(id)) => {
3836 // Since this def is a label, it is never read.
3837 self.record_def(expr.id, PathResolution::new(Def::Label(id)));
3838 self.unused_labels.remove(&id);
3841 span_bug!(expr.span, "label wasn't mapped to a label def!");
3845 // visit `break` argument if any
3846 visit::walk_expr(self, expr);
3849 ExprKind::IfLet(ref pats, ref subexpression, ref if_block, ref optional_else) => {
3850 self.visit_expr(subexpression);
3852 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
3853 let mut bindings_list = FxHashMap();
3855 self.resolve_pattern(pat, PatternSource::IfLet, &mut bindings_list);
3857 // This has to happen *after* we determine which pat_idents are variants
3858 self.check_consistent_bindings(pats);
3859 self.visit_block(if_block);
3860 self.ribs[ValueNS].pop();
3862 optional_else.as_ref().map(|expr| self.visit_expr(expr));
3865 ExprKind::Loop(ref block, label) => self.resolve_labeled_block(label, expr.id, &block),
3867 ExprKind::While(ref subexpression, ref block, label) => {
3868 self.with_resolved_label(label, expr.id, |this| {
3869 this.visit_expr(subexpression);
3870 this.visit_block(block);
3874 ExprKind::WhileLet(ref pats, ref subexpression, ref block, label) => {
3875 self.with_resolved_label(label, expr.id, |this| {
3876 this.visit_expr(subexpression);
3877 this.ribs[ValueNS].push(Rib::new(NormalRibKind));
3878 let mut bindings_list = FxHashMap();
3880 this.resolve_pattern(pat, PatternSource::WhileLet, &mut bindings_list);
3882 // This has to happen *after* we determine which pat_idents are variants
3883 this.check_consistent_bindings(pats);
3884 this.visit_block(block);
3885 this.ribs[ValueNS].pop();
3889 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, label) => {
3890 self.visit_expr(subexpression);
3891 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
3892 self.resolve_pattern(pattern, PatternSource::For, &mut FxHashMap());
3894 self.resolve_labeled_block(label, expr.id, block);
3896 self.ribs[ValueNS].pop();
3899 ExprKind::Block(ref block, label) => self.resolve_labeled_block(label, block.id, block),
3901 // Equivalent to `visit::walk_expr` + passing some context to children.
3902 ExprKind::Field(ref subexpression, _) => {
3903 self.resolve_expr(subexpression, Some(expr));
3905 ExprKind::MethodCall(ref segment, ref arguments) => {
3906 let mut arguments = arguments.iter();
3907 self.resolve_expr(arguments.next().unwrap(), Some(expr));
3908 for argument in arguments {
3909 self.resolve_expr(argument, None);
3911 self.visit_path_segment(expr.span, segment);
3914 ExprKind::Call(ref callee, ref arguments) => {
3915 self.resolve_expr(callee, Some(expr));
3916 for argument in arguments {
3917 self.resolve_expr(argument, None);
3920 ExprKind::Type(ref type_expr, _) => {
3921 self.current_type_ascription.push(type_expr.span);
3922 visit::walk_expr(self, expr);
3923 self.current_type_ascription.pop();
3925 // Resolve the body of async exprs inside the async closure to which they desugar
3926 ExprKind::Async(_, async_closure_id, ref block) => {
3927 let rib_kind = ClosureRibKind(async_closure_id);
3928 self.ribs[ValueNS].push(Rib::new(rib_kind));
3929 self.label_ribs.push(Rib::new(rib_kind));
3930 self.visit_block(&block);
3931 self.label_ribs.pop();
3932 self.ribs[ValueNS].pop();
3934 // `async |x| ...` gets desugared to `|x| future_from_generator(|| ...)`, so we need to
3935 // resolve the arguments within the proper scopes so that usages of them inside the
3936 // closure are detected as upvars rather than normal closure arg usages.
3938 _, IsAsync::Async(inner_closure_id), _, ref fn_decl, ref body, _span) =>
3940 let rib_kind = ClosureRibKind(expr.id);
3941 self.ribs[ValueNS].push(Rib::new(rib_kind));
3942 self.label_ribs.push(Rib::new(rib_kind));
3943 // Resolve arguments:
3944 let mut bindings_list = FxHashMap();
3945 for argument in &fn_decl.inputs {
3946 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
3947 self.visit_ty(&argument.ty);
3949 // No need to resolve return type-- the outer closure return type is
3950 // FunctionRetTy::Default
3952 // Now resolve the inner closure
3954 let rib_kind = ClosureRibKind(inner_closure_id);
3955 self.ribs[ValueNS].push(Rib::new(rib_kind));
3956 self.label_ribs.push(Rib::new(rib_kind));
3957 // No need to resolve arguments: the inner closure has none.
3958 // Resolve the return type:
3959 visit::walk_fn_ret_ty(self, &fn_decl.output);
3961 self.visit_expr(body);
3962 self.label_ribs.pop();
3963 self.ribs[ValueNS].pop();
3965 self.label_ribs.pop();
3966 self.ribs[ValueNS].pop();
3969 visit::walk_expr(self, expr);
3974 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3976 ExprKind::Field(_, ident) => {
3977 // FIXME(#6890): Even though you can't treat a method like a
3978 // field, we need to add any trait methods we find that match
3979 // the field name so that we can do some nice error reporting
3980 // later on in typeck.
3981 let traits = self.get_traits_containing_item(ident, ValueNS);
3982 self.trait_map.insert(expr.id, traits);
3984 ExprKind::MethodCall(ref segment, ..) => {
3985 debug!("(recording candidate traits for expr) recording traits for {}",
3987 let traits = self.get_traits_containing_item(segment.ident, ValueNS);
3988 self.trait_map.insert(expr.id, traits);
3996 fn get_traits_containing_item(&mut self, mut ident: Ident, ns: Namespace)
3997 -> Vec<TraitCandidate> {
3998 debug!("(getting traits containing item) looking for '{}'", ident.name);
4000 let mut found_traits = Vec::new();
4001 // Look for the current trait.
4002 if let Some((module, _)) = self.current_trait_ref {
4003 if self.resolve_ident_in_module(module, ident, ns, false, false, module.span).is_ok() {
4004 let def_id = module.def_id().unwrap();
4005 found_traits.push(TraitCandidate { def_id: def_id, import_id: None });
4009 ident.span = ident.span.modern();
4010 let mut search_module = self.current_module;
4012 self.get_traits_in_module_containing_item(ident, ns, search_module, &mut found_traits);
4014 unwrap_or!(self.hygienic_lexical_parent(search_module, &mut ident.span), break);
4017 if let Some(prelude) = self.prelude {
4018 if !search_module.no_implicit_prelude {
4019 self.get_traits_in_module_containing_item(ident, ns, prelude, &mut found_traits);
4026 fn get_traits_in_module_containing_item(&mut self,
4030 found_traits: &mut Vec<TraitCandidate>) {
4031 let mut traits = module.traits.borrow_mut();
4032 if traits.is_none() {
4033 let mut collected_traits = Vec::new();
4034 module.for_each_child(|name, ns, binding| {
4035 if ns != TypeNS { return }
4036 if let Def::Trait(_) = binding.def() {
4037 collected_traits.push((name, binding));
4040 *traits = Some(collected_traits.into_boxed_slice());
4043 for &(trait_name, binding) in traits.as_ref().unwrap().iter() {
4044 let module = binding.module().unwrap();
4045 let mut ident = ident;
4046 if ident.span.glob_adjust(module.expansion, binding.span.ctxt().modern()).is_none() {
4049 if self.resolve_ident_in_module_unadjusted(module, ident, ns, false, false, module.span)
4051 let import_id = match binding.kind {
4052 NameBindingKind::Import { directive, .. } => {
4053 self.maybe_unused_trait_imports.insert(directive.id);
4054 self.add_to_glob_map(directive.id, trait_name);
4059 let trait_def_id = module.def_id().unwrap();
4060 found_traits.push(TraitCandidate { def_id: trait_def_id, import_id: import_id });
4065 /// When name resolution fails, this method can be used to look up candidate
4066 /// entities with the expected name. It allows filtering them using the
4067 /// supplied predicate (which should be used to only accept the types of
4068 /// definitions expected e.g. traits). The lookup spans across all crates.
4070 /// NOTE: The method does not look into imports, but this is not a problem,
4071 /// since we report the definitions (thus, the de-aliased imports).
4072 fn lookup_import_candidates<FilterFn>(&mut self,
4074 namespace: Namespace,
4075 filter_fn: FilterFn)
4076 -> Vec<ImportSuggestion>
4077 where FilterFn: Fn(Def) -> bool
4079 let mut candidates = Vec::new();
4080 let mut worklist = Vec::new();
4081 let mut seen_modules = FxHashSet();
4082 worklist.push((self.graph_root, Vec::new(), false));
4084 while let Some((in_module,
4086 in_module_is_extern)) = worklist.pop() {
4087 self.populate_module_if_necessary(in_module);
4089 // We have to visit module children in deterministic order to avoid
4090 // instabilities in reported imports (#43552).
4091 in_module.for_each_child_stable(|ident, ns, name_binding| {
4092 // avoid imports entirely
4093 if name_binding.is_import() && !name_binding.is_extern_crate() { return; }
4094 // avoid non-importable candidates as well
4095 if !name_binding.is_importable() { return; }
4097 // collect results based on the filter function
4098 if ident.name == lookup_name && ns == namespace {
4099 if filter_fn(name_binding.def()) {
4101 let mut segms = path_segments.clone();
4102 segms.push(ast::PathSegment::from_ident(ident));
4104 span: name_binding.span,
4107 // the entity is accessible in the following cases:
4108 // 1. if it's defined in the same crate, it's always
4109 // accessible (since private entities can be made public)
4110 // 2. if it's defined in another crate, it's accessible
4111 // only if both the module is public and the entity is
4112 // declared as public (due to pruning, we don't explore
4113 // outside crate private modules => no need to check this)
4114 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
4115 candidates.push(ImportSuggestion { path: path });
4120 // collect submodules to explore
4121 if let Some(module) = name_binding.module() {
4123 let mut path_segments = path_segments.clone();
4124 path_segments.push(ast::PathSegment::from_ident(ident));
4126 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
4127 // add the module to the lookup
4128 let is_extern = in_module_is_extern || name_binding.is_extern_crate();
4129 if seen_modules.insert(module.def_id().unwrap()) {
4130 worklist.push((module, path_segments, is_extern));
4140 fn find_module(&mut self,
4142 -> Option<(Module<'a>, ImportSuggestion)>
4144 let mut result = None;
4145 let mut worklist = Vec::new();
4146 let mut seen_modules = FxHashSet();
4147 worklist.push((self.graph_root, Vec::new()));
4149 while let Some((in_module, path_segments)) = worklist.pop() {
4150 // abort if the module is already found
4151 if let Some(_) = result { break; }
4153 self.populate_module_if_necessary(in_module);
4155 in_module.for_each_child_stable(|ident, _, name_binding| {
4156 // abort if the module is already found or if name_binding is private external
4157 if result.is_some() || !name_binding.vis.is_visible_locally() {
4160 if let Some(module) = name_binding.module() {
4162 let mut path_segments = path_segments.clone();
4163 path_segments.push(ast::PathSegment::from_ident(ident));
4164 if module.def() == Some(module_def) {
4166 span: name_binding.span,
4167 segments: path_segments,
4169 result = Some((module, ImportSuggestion { path: path }));
4171 // add the module to the lookup
4172 if seen_modules.insert(module.def_id().unwrap()) {
4173 worklist.push((module, path_segments));
4183 fn collect_enum_variants(&mut self, enum_def: Def) -> Option<Vec<Path>> {
4184 if let Def::Enum(..) = enum_def {} else {
4185 panic!("Non-enum def passed to collect_enum_variants: {:?}", enum_def)
4188 self.find_module(enum_def).map(|(enum_module, enum_import_suggestion)| {
4189 self.populate_module_if_necessary(enum_module);
4191 let mut variants = Vec::new();
4192 enum_module.for_each_child_stable(|ident, _, name_binding| {
4193 if let Def::Variant(..) = name_binding.def() {
4194 let mut segms = enum_import_suggestion.path.segments.clone();
4195 segms.push(ast::PathSegment::from_ident(ident));
4196 variants.push(Path {
4197 span: name_binding.span,
4206 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
4207 debug!("(recording def) recording {:?} for {}", resolution, node_id);
4208 if let Some(prev_res) = self.def_map.insert(node_id, resolution) {
4209 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
4213 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
4215 ast::VisibilityKind::Public => ty::Visibility::Public,
4216 ast::VisibilityKind::Crate(..) => {
4217 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
4219 ast::VisibilityKind::Inherited => {
4220 ty::Visibility::Restricted(self.current_module.normal_ancestor_id)
4222 ast::VisibilityKind::Restricted { ref path, id, .. } => {
4223 // Visibilities are resolved as global by default, add starting root segment.
4224 let segments = path.make_root().iter().chain(path.segments.iter())
4225 .map(|seg| seg.ident)
4226 .collect::<Vec<_>>();
4227 let def = self.smart_resolve_path_fragment(
4232 PathSource::Visibility,
4233 CrateLint::SimplePath(id),
4235 if def == Def::Err {
4236 ty::Visibility::Public
4238 let vis = ty::Visibility::Restricted(def.def_id());
4239 if self.is_accessible(vis) {
4242 self.session.span_err(path.span, "visibilities can only be restricted \
4243 to ancestor modules");
4244 ty::Visibility::Public
4251 fn is_accessible(&self, vis: ty::Visibility) -> bool {
4252 vis.is_accessible_from(self.current_module.normal_ancestor_id, self)
4255 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
4256 vis.is_accessible_from(module.normal_ancestor_id, self)
4259 fn report_errors(&mut self, krate: &Crate) {
4260 self.report_shadowing_errors();
4261 self.report_with_use_injections(krate);
4262 self.report_proc_macro_import(krate);
4263 let mut reported_spans = FxHashSet();
4265 for &AmbiguityError { span, name, b1, b2, lexical } in &self.ambiguity_errors {
4266 if !reported_spans.insert(span) { continue }
4267 let participle = |binding: &NameBinding| {
4268 if binding.is_import() { "imported" } else { "defined" }
4270 let msg1 = format!("`{}` could refer to the name {} here", name, participle(b1));
4271 let msg2 = format!("`{}` could also refer to the name {} here", name, participle(b2));
4272 let note = if b1.expansion == Mark::root() || !lexical && b1.is_glob_import() {
4273 format!("consider adding an explicit import of `{}` to disambiguate", name)
4274 } else if let Def::Macro(..) = b1.def() {
4275 format!("macro-expanded {} do not shadow",
4276 if b1.is_import() { "macro imports" } else { "macros" })
4278 format!("macro-expanded {} do not shadow when used in a macro invocation path",
4279 if b1.is_import() { "imports" } else { "items" })
4282 let mut err = struct_span_err!(self.session, span, E0659, "`{}` is ambiguous", name);
4283 err.span_note(b1.span, &msg1);
4285 Def::Macro(..) if b2.span == DUMMY_SP =>
4286 err.note(&format!("`{}` is also a builtin macro", name)),
4287 _ => err.span_note(b2.span, &msg2),
4289 err.note(¬e).emit();
4292 for &PrivacyError(span, name, binding) in &self.privacy_errors {
4293 if !reported_spans.insert(span) { continue }
4294 span_err!(self.session, span, E0603, "{} `{}` is private", binding.descr(), name);
4298 fn report_with_use_injections(&mut self, krate: &Crate) {
4299 for UseError { mut err, candidates, node_id, better } in self.use_injections.drain(..) {
4300 let (span, found_use) = UsePlacementFinder::check(krate, node_id);
4301 if !candidates.is_empty() {
4302 show_candidates(&mut err, span, &candidates, better, found_use);
4308 fn report_shadowing_errors(&mut self) {
4309 for (ident, scope) in replace(&mut self.lexical_macro_resolutions, Vec::new()) {
4310 self.resolve_legacy_scope(scope, ident, true);
4313 let mut reported_errors = FxHashSet();
4314 for binding in replace(&mut self.disallowed_shadowing, Vec::new()) {
4315 if self.resolve_legacy_scope(&binding.parent, binding.ident, false).is_some() &&
4316 reported_errors.insert((binding.ident, binding.span)) {
4317 let msg = format!("`{}` is already in scope", binding.ident);
4318 self.session.struct_span_err(binding.span, &msg)
4319 .note("macro-expanded `macro_rules!`s may not shadow \
4320 existing macros (see RFC 1560)")
4326 fn report_conflict<'b>(&mut self,
4330 new_binding: &NameBinding<'b>,
4331 old_binding: &NameBinding<'b>) {
4332 // Error on the second of two conflicting names
4333 if old_binding.span.lo() > new_binding.span.lo() {
4334 return self.report_conflict(parent, ident, ns, old_binding, new_binding);
4337 let container = match parent.kind {
4338 ModuleKind::Def(Def::Mod(_), _) => "module",
4339 ModuleKind::Def(Def::Trait(_), _) => "trait",
4340 ModuleKind::Block(..) => "block",
4344 let old_noun = match old_binding.is_import() {
4346 false => "definition",
4349 let new_participle = match new_binding.is_import() {
4354 let (name, span) = (ident.name, self.session.codemap().def_span(new_binding.span));
4356 if let Some(s) = self.name_already_seen.get(&name) {
4362 let old_kind = match (ns, old_binding.module()) {
4363 (ValueNS, _) => "value",
4364 (MacroNS, _) => "macro",
4365 (TypeNS, _) if old_binding.is_extern_crate() => "extern crate",
4366 (TypeNS, Some(module)) if module.is_normal() => "module",
4367 (TypeNS, Some(module)) if module.is_trait() => "trait",
4368 (TypeNS, _) => "type",
4371 let namespace = match ns {
4377 let msg = format!("the name `{}` is defined multiple times", name);
4379 let mut err = match (old_binding.is_extern_crate(), new_binding.is_extern_crate()) {
4380 (true, true) => struct_span_err!(self.session, span, E0259, "{}", msg),
4381 (true, _) | (_, true) => match new_binding.is_import() && old_binding.is_import() {
4382 true => struct_span_err!(self.session, span, E0254, "{}", msg),
4383 false => struct_span_err!(self.session, span, E0260, "{}", msg),
4385 _ => match (old_binding.is_import(), new_binding.is_import()) {
4386 (false, false) => struct_span_err!(self.session, span, E0428, "{}", msg),
4387 (true, true) => struct_span_err!(self.session, span, E0252, "{}", msg),
4388 _ => struct_span_err!(self.session, span, E0255, "{}", msg),
4392 err.note(&format!("`{}` must be defined only once in the {} namespace of this {}",
4397 err.span_label(span, format!("`{}` re{} here", name, new_participle));
4398 if old_binding.span != DUMMY_SP {
4399 err.span_label(self.session.codemap().def_span(old_binding.span),
4400 format!("previous {} of the {} `{}` here", old_noun, old_kind, name));
4403 // See https://github.com/rust-lang/rust/issues/32354
4404 if old_binding.is_import() || new_binding.is_import() {
4405 let binding = if new_binding.is_import() && new_binding.span != DUMMY_SP {
4411 let cm = self.session.codemap();
4412 let rename_msg = "You can use `as` to change the binding name of the import";
4414 if let (Ok(snippet), false) = (cm.span_to_snippet(binding.span),
4415 binding.is_renamed_extern_crate()) {
4416 let suggested_name = if name.as_str().chars().next().unwrap().is_uppercase() {
4417 format!("Other{}", name)
4419 format!("other_{}", name)
4422 err.span_suggestion(binding.span,
4424 if snippet.ends_with(';') {
4425 format!("{} as {};",
4426 &snippet[..snippet.len()-1],
4429 format!("{} as {}", snippet, suggested_name)
4432 err.span_label(binding.span, rename_msg);
4437 self.name_already_seen.insert(name, span);
4440 fn check_proc_macro_attrs(&mut self, attrs: &[ast::Attribute]) {
4441 if self.proc_macro_enabled { return; }
4444 if attr.path.segments.len() > 1 {
4447 let ident = attr.path.segments[0].ident;
4448 let result = self.resolve_lexical_macro_path_segment(ident,
4452 if let Ok(binding) = result {
4453 if let SyntaxExtension::AttrProcMacro(..) = *binding.binding().get_macro(self) {
4454 attr::mark_known(attr);
4456 let msg = "attribute procedural macros are experimental";
4457 let feature = "proc_macro";
4459 feature_err(&self.session.parse_sess, feature,
4460 attr.span, GateIssue::Language, msg)
4461 .span_label(binding.span(), "procedural macro imported here")
4469 fn is_self_type(path: &[Ident], namespace: Namespace) -> bool {
4470 namespace == TypeNS && path.len() == 1 && path[0].name == keywords::SelfType.name()
4473 fn is_self_value(path: &[Ident], namespace: Namespace) -> bool {
4474 namespace == ValueNS && path.len() == 1 && path[0].name == keywords::SelfValue.name()
4477 fn names_to_string(idents: &[Ident]) -> String {
4478 let mut result = String::new();
4479 for (i, ident) in idents.iter()
4480 .filter(|ident| ident.name != keywords::CrateRoot.name())
4483 result.push_str("::");
4485 result.push_str(&ident.as_str());
4490 fn path_names_to_string(path: &Path) -> String {
4491 names_to_string(&path.segments.iter()
4492 .map(|seg| seg.ident)
4493 .collect::<Vec<_>>())
4496 /// Get the path for an enum and the variant from an `ImportSuggestion` for an enum variant.
4497 fn import_candidate_to_paths(suggestion: &ImportSuggestion) -> (Span, String, String) {
4498 let variant_path = &suggestion.path;
4499 let variant_path_string = path_names_to_string(variant_path);
4501 let path_len = suggestion.path.segments.len();
4502 let enum_path = ast::Path {
4503 span: suggestion.path.span,
4504 segments: suggestion.path.segments[0..path_len - 1].to_vec(),
4506 let enum_path_string = path_names_to_string(&enum_path);
4508 (suggestion.path.span, variant_path_string, enum_path_string)
4512 /// When an entity with a given name is not available in scope, we search for
4513 /// entities with that name in all crates. This method allows outputting the
4514 /// results of this search in a programmer-friendly way
4515 fn show_candidates(err: &mut DiagnosticBuilder,
4516 // This is `None` if all placement locations are inside expansions
4518 candidates: &[ImportSuggestion],
4522 // we want consistent results across executions, but candidates are produced
4523 // by iterating through a hash map, so make sure they are ordered:
4524 let mut path_strings: Vec<_> =
4525 candidates.into_iter().map(|c| path_names_to_string(&c.path)).collect();
4526 path_strings.sort();
4528 let better = if better { "better " } else { "" };
4529 let msg_diff = match path_strings.len() {
4530 1 => " is found in another module, you can import it",
4531 _ => "s are found in other modules, you can import them",
4533 let msg = format!("possible {}candidate{} into scope", better, msg_diff);
4535 if let Some(span) = span {
4536 for candidate in &mut path_strings {
4537 // produce an additional newline to separate the new use statement
4538 // from the directly following item.
4539 let additional_newline = if found_use {
4544 *candidate = format!("use {};\n{}", candidate, additional_newline);
4547 err.span_suggestions(span, &msg, path_strings);
4551 for candidate in path_strings {
4553 msg.push_str(&candidate);
4558 /// A somewhat inefficient routine to obtain the name of a module.
4559 fn module_to_string(module: Module) -> Option<String> {
4560 let mut names = Vec::new();
4562 fn collect_mod(names: &mut Vec<Ident>, module: Module) {
4563 if let ModuleKind::Def(_, name) = module.kind {
4564 if let Some(parent) = module.parent {
4565 names.push(Ident::with_empty_ctxt(name));
4566 collect_mod(names, parent);
4569 // danger, shouldn't be ident?
4570 names.push(Ident::from_str("<opaque>"));
4571 collect_mod(names, module.parent.unwrap());
4574 collect_mod(&mut names, module);
4576 if names.is_empty() {
4579 Some(names_to_string(&names.into_iter()
4581 .collect::<Vec<_>>()))
4584 fn err_path_resolution() -> PathResolution {
4585 PathResolution::new(Def::Err)
4588 #[derive(PartialEq,Copy, Clone)]
4589 pub enum MakeGlobMap {
4594 #[derive(Copy, Clone, Debug)]
4596 /// Do not issue the lint
4599 /// This lint applies to some random path like `impl ::foo::Bar`
4600 /// or whatever. In this case, we can take the span of that path.
4603 /// This lint comes from a `use` statement. In this case, what we
4604 /// care about really is the *root* `use` statement; e.g., if we
4605 /// have nested things like `use a::{b, c}`, we care about the
4607 UsePath { root_id: NodeId, root_span: Span },
4609 /// This is the "trait item" from a fully qualified path. For example,
4610 /// we might be resolving `X::Y::Z` from a path like `<T as X::Y>::Z`.
4611 /// The `path_span` is the span of the to the trait itself (`X::Y`).
4612 QPathTrait { qpath_id: NodeId, qpath_span: Span },
4615 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }