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/")]
16 #![feature(rustc_diagnostic_macros)]
22 extern crate syntax_pos;
23 extern crate rustc_errors as errors;
27 extern crate rustc_data_structures;
29 use self::Namespace::*;
30 use self::TypeParameters::*;
33 use rustc::hir::map::{Definitions, DefCollector};
34 use rustc::hir::{self, PrimTy, TyBool, TyChar, TyFloat, TyInt, TyUint, TyStr};
35 use rustc::middle::cstore::{CrateStore, CrateLoader};
36 use rustc::session::Session;
38 use rustc::hir::def::*;
39 use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, DefId};
41 use rustc::hir::{Freevar, FreevarMap, TraitCandidate, TraitMap, GlobMap};
42 use rustc::util::nodemap::{NodeMap, NodeSet, FxHashMap, FxHashSet, DefIdMap};
44 use syntax::codemap::{dummy_spanned, respan};
45 use syntax::ext::hygiene::{Mark, MarkKind, SyntaxContext};
46 use syntax::ast::{self, Name, NodeId, Ident, SpannedIdent, FloatTy, IntTy, UintTy};
47 use syntax::ext::base::SyntaxExtension;
48 use syntax::ext::base::Determinacy::{self, Determined, Undetermined};
49 use syntax::ext::base::MacroKind;
50 use syntax::symbol::{Symbol, keywords};
51 use syntax::util::lev_distance::find_best_match_for_name;
53 use syntax::visit::{self, FnKind, Visitor};
55 use syntax::ast::{Arm, BindingMode, Block, Crate, Expr, ExprKind};
56 use syntax::ast::{FnDecl, ForeignItem, ForeignItemKind, GenericParam, Generics};
57 use syntax::ast::{Item, ItemKind, ImplItem, ImplItemKind};
58 use syntax::ast::{Label, Local, Mutability, Pat, PatKind, Path};
59 use syntax::ast::{QSelf, TraitItemKind, TraitRef, Ty, TyKind};
60 use syntax::feature_gate::{feature_err, emit_feature_err, GateIssue};
61 use syntax::parse::token;
63 use syntax_pos::{Span, DUMMY_SP, MultiSpan};
64 use errors::{DiagnosticBuilder, DiagnosticId};
66 use std::cell::{Cell, RefCell};
68 use std::collections::BTreeSet;
71 use std::mem::replace;
74 use resolve_imports::{ImportDirective, ImportDirectiveSubclass, NameResolution, ImportResolver};
75 use macros::{InvocationData, LegacyBinding, LegacyScope, MacroBinding};
77 // NB: This module needs to be declared first so diagnostics are
78 // registered before they are used.
83 mod build_reduced_graph;
86 /// A free importable items suggested in case of resolution failure.
87 struct ImportSuggestion {
91 /// A field or associated item from self type suggested in case of resolution failure.
92 enum AssocSuggestion {
101 origin: BTreeSet<Span>,
102 target: BTreeSet<Span>,
105 impl PartialOrd for BindingError {
106 fn partial_cmp(&self, other: &BindingError) -> Option<cmp::Ordering> {
107 Some(self.cmp(other))
111 impl PartialEq for BindingError {
112 fn eq(&self, other: &BindingError) -> bool {
113 self.name == other.name
117 impl Ord for BindingError {
118 fn cmp(&self, other: &BindingError) -> cmp::Ordering {
119 self.name.cmp(&other.name)
123 enum ResolutionError<'a> {
124 /// error E0401: can't use type parameters from outer function
125 TypeParametersFromOuterFunction,
126 /// error E0403: the name is already used for a type parameter in this type parameter list
127 NameAlreadyUsedInTypeParameterList(Name, &'a Span),
128 /// error E0407: method is not a member of trait
129 MethodNotMemberOfTrait(Name, &'a str),
130 /// error E0437: type is not a member of trait
131 TypeNotMemberOfTrait(Name, &'a str),
132 /// error E0438: const is not a member of trait
133 ConstNotMemberOfTrait(Name, &'a str),
134 /// error E0408: variable `{}` is not bound in all patterns
135 VariableNotBoundInPattern(&'a BindingError),
136 /// error E0409: variable `{}` is bound in inconsistent ways within the same match arm
137 VariableBoundWithDifferentMode(Name, Span),
138 /// error E0415: identifier is bound more than once in this parameter list
139 IdentifierBoundMoreThanOnceInParameterList(&'a str),
140 /// error E0416: identifier is bound more than once in the same pattern
141 IdentifierBoundMoreThanOnceInSamePattern(&'a str),
142 /// error E0426: use of undeclared label
143 UndeclaredLabel(&'a str, Option<Name>),
144 /// error E0429: `self` imports are only allowed within a { } list
145 SelfImportsOnlyAllowedWithin,
146 /// error E0430: `self` import can only appear once in the list
147 SelfImportCanOnlyAppearOnceInTheList,
148 /// error E0431: `self` import can only appear in an import list with a non-empty prefix
149 SelfImportOnlyInImportListWithNonEmptyPrefix,
150 /// error E0432: unresolved import
151 UnresolvedImport(Option<(Span, &'a str, &'a str)>),
152 /// error E0433: failed to resolve
153 FailedToResolve(&'a str),
154 /// error E0434: can't capture dynamic environment in a fn item
155 CannotCaptureDynamicEnvironmentInFnItem,
156 /// error E0435: attempt to use a non-constant value in a constant
157 AttemptToUseNonConstantValueInConstant,
158 /// error E0530: X bindings cannot shadow Ys
159 BindingShadowsSomethingUnacceptable(&'a str, Name, &'a NameBinding<'a>),
160 /// error E0128: type parameters with a default cannot use forward declared identifiers
161 ForwardDeclaredTyParam,
164 fn resolve_error<'sess, 'a>(resolver: &'sess Resolver,
166 resolution_error: ResolutionError<'a>) {
167 resolve_struct_error(resolver, span, resolution_error).emit();
170 fn resolve_struct_error<'sess, 'a>(resolver: &'sess Resolver,
172 resolution_error: ResolutionError<'a>)
173 -> DiagnosticBuilder<'sess> {
174 match resolution_error {
175 ResolutionError::TypeParametersFromOuterFunction => {
176 let mut err = struct_span_err!(resolver.session,
179 "can't use type parameters from outer function; \
180 try using a local type parameter instead");
181 err.span_label(span, "use of type variable from outer function");
184 ResolutionError::NameAlreadyUsedInTypeParameterList(name, first_use_span) => {
185 let mut err = struct_span_err!(resolver.session,
188 "the name `{}` is already used for a type parameter \
189 in this type parameter list",
191 err.span_label(span, "already used");
192 err.span_label(first_use_span.clone(), format!("first use of `{}`", name));
195 ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
196 let mut err = struct_span_err!(resolver.session,
199 "method `{}` is not a member of trait `{}`",
202 err.span_label(span, format!("not a member of trait `{}`", trait_));
205 ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
206 let mut err = struct_span_err!(resolver.session,
209 "type `{}` is not a member of trait `{}`",
212 err.span_label(span, format!("not a member of trait `{}`", trait_));
215 ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
216 let mut err = struct_span_err!(resolver.session,
219 "const `{}` is not a member of trait `{}`",
222 err.span_label(span, format!("not a member of trait `{}`", trait_));
225 ResolutionError::VariableNotBoundInPattern(binding_error) => {
226 let target_sp = binding_error.target.iter().map(|x| *x).collect::<Vec<_>>();
227 let msp = MultiSpan::from_spans(target_sp.clone());
228 let msg = format!("variable `{}` is not bound in all patterns", binding_error.name);
229 let mut err = resolver.session.struct_span_err_with_code(
232 DiagnosticId::Error("E0408".into()),
234 for sp in target_sp {
235 err.span_label(sp, format!("pattern doesn't bind `{}`", binding_error.name));
237 let origin_sp = binding_error.origin.iter().map(|x| *x).collect::<Vec<_>>();
238 for sp in origin_sp {
239 err.span_label(sp, "variable not in all patterns");
243 ResolutionError::VariableBoundWithDifferentMode(variable_name,
244 first_binding_span) => {
245 let mut err = struct_span_err!(resolver.session,
248 "variable `{}` is bound in inconsistent \
249 ways within the same match arm",
251 err.span_label(span, "bound in different ways");
252 err.span_label(first_binding_span, "first binding");
255 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
256 let mut err = struct_span_err!(resolver.session,
259 "identifier `{}` is bound more than once in this parameter list",
261 err.span_label(span, "used as parameter more than once");
264 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
265 let mut err = struct_span_err!(resolver.session,
268 "identifier `{}` is bound more than once in the same pattern",
270 err.span_label(span, "used in a pattern more than once");
273 ResolutionError::UndeclaredLabel(name, lev_candidate) => {
274 let mut err = struct_span_err!(resolver.session,
277 "use of undeclared label `{}`",
279 if let Some(lev_candidate) = lev_candidate {
280 err.span_label(span, format!("did you mean `{}`?", lev_candidate));
282 err.span_label(span, format!("undeclared label `{}`", name));
286 ResolutionError::SelfImportsOnlyAllowedWithin => {
287 struct_span_err!(resolver.session,
291 "`self` imports are only allowed within a { } list")
293 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
294 let mut err = struct_span_err!(resolver.session, span, E0430,
295 "`self` import can only appear once in an import list");
296 err.span_label(span, "can only appear once in an import list");
299 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
300 let mut err = struct_span_err!(resolver.session, span, E0431,
301 "`self` import can only appear in an import list with \
302 a non-empty prefix");
303 err.span_label(span, "can only appear in an import list with a non-empty prefix");
306 ResolutionError::UnresolvedImport(name) => {
307 let (span, msg) = match name {
308 Some((sp, n, _)) => (sp, format!("unresolved import `{}`", n)),
309 None => (span, "unresolved import".to_owned()),
311 let mut err = struct_span_err!(resolver.session, span, E0432, "{}", msg);
312 if let Some((_, _, p)) = name {
313 err.span_label(span, p);
317 ResolutionError::FailedToResolve(msg) => {
318 let mut err = struct_span_err!(resolver.session, span, E0433,
319 "failed to resolve. {}", msg);
320 err.span_label(span, msg);
323 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
324 let mut err = struct_span_err!(resolver.session,
328 "can't capture dynamic environment in a fn item");
329 err.help("use the `|| { ... }` closure form instead");
332 ResolutionError::AttemptToUseNonConstantValueInConstant => {
333 let mut err = struct_span_err!(resolver.session, span, E0435,
334 "attempt to use a non-constant value in a constant");
335 err.span_label(span, "non-constant value");
338 ResolutionError::BindingShadowsSomethingUnacceptable(what_binding, name, binding) => {
339 let shadows_what = PathResolution::new(binding.def()).kind_name();
340 let mut err = struct_span_err!(resolver.session,
343 "{}s cannot shadow {}s", what_binding, shadows_what);
344 err.span_label(span, format!("cannot be named the same as a {}", shadows_what));
345 let participle = if binding.is_import() { "imported" } else { "defined" };
346 let msg = format!("a {} `{}` is {} here", shadows_what, name, participle);
347 err.span_label(binding.span, msg);
350 ResolutionError::ForwardDeclaredTyParam => {
351 let mut err = struct_span_err!(resolver.session, span, E0128,
352 "type parameters with a default cannot use \
353 forward declared identifiers");
354 err.span_label(span, format!("defaulted type parameters cannot be forward declared"));
360 #[derive(Copy, Clone, Debug)]
363 binding_mode: BindingMode,
366 // Map from the name in a pattern to its binding mode.
367 type BindingMap = FxHashMap<Ident, BindingInfo>;
369 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
380 fn descr(self) -> &'static str {
382 PatternSource::Match => "match binding",
383 PatternSource::IfLet => "if let binding",
384 PatternSource::WhileLet => "while let binding",
385 PatternSource::Let => "let binding",
386 PatternSource::For => "for binding",
387 PatternSource::FnParam => "function parameter",
392 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
393 enum AliasPossibility {
398 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
399 enum PathSource<'a> {
400 // Type paths `Path`.
402 // Trait paths in bounds or impls.
403 Trait(AliasPossibility),
404 // Expression paths `path`, with optional parent context.
405 Expr(Option<&'a Expr>),
406 // Paths in path patterns `Path`.
408 // Paths in struct expressions and patterns `Path { .. }`.
410 // Paths in tuple struct patterns `Path(..)`.
412 // `m::A::B` in `<T as m::A>::B::C`.
413 TraitItem(Namespace),
414 // Path in `pub(path)`
416 // Path in `use a::b::{...};`
420 impl<'a> PathSource<'a> {
421 fn namespace(self) -> Namespace {
423 PathSource::Type | PathSource::Trait(_) | PathSource::Struct |
424 PathSource::Visibility | PathSource::ImportPrefix => TypeNS,
425 PathSource::Expr(..) | PathSource::Pat | PathSource::TupleStruct => ValueNS,
426 PathSource::TraitItem(ns) => ns,
430 fn global_by_default(self) -> bool {
432 PathSource::Visibility | PathSource::ImportPrefix => true,
433 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
434 PathSource::Struct | PathSource::TupleStruct |
435 PathSource::Trait(_) | PathSource::TraitItem(..) => false,
439 fn defer_to_typeck(self) -> bool {
441 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
442 PathSource::Struct | PathSource::TupleStruct => true,
443 PathSource::Trait(_) | PathSource::TraitItem(..) |
444 PathSource::Visibility | PathSource::ImportPrefix => false,
448 fn descr_expected(self) -> &'static str {
450 PathSource::Type => "type",
451 PathSource::Trait(_) => "trait",
452 PathSource::Pat => "unit struct/variant or constant",
453 PathSource::Struct => "struct, variant or union type",
454 PathSource::TupleStruct => "tuple struct/variant",
455 PathSource::Visibility => "module",
456 PathSource::ImportPrefix => "module or enum",
457 PathSource::TraitItem(ns) => match ns {
458 TypeNS => "associated type",
459 ValueNS => "method or associated constant",
460 MacroNS => bug!("associated macro"),
462 PathSource::Expr(parent) => match parent.map(|p| &p.node) {
463 // "function" here means "anything callable" rather than `Def::Fn`,
464 // this is not precise but usually more helpful than just "value".
465 Some(&ExprKind::Call(..)) => "function",
471 fn is_expected(self, def: Def) -> bool {
473 PathSource::Type => match def {
474 Def::Struct(..) | Def::Union(..) | Def::Enum(..) |
475 Def::Trait(..) | Def::TyAlias(..) | Def::AssociatedTy(..) |
476 Def::PrimTy(..) | Def::TyParam(..) | Def::SelfTy(..) |
477 Def::TyForeign(..) => true,
480 PathSource::Trait(AliasPossibility::No) => match def {
481 Def::Trait(..) => true,
484 PathSource::Trait(AliasPossibility::Maybe) => match def {
485 Def::Trait(..) => true,
486 Def::TraitAlias(..) => true,
489 PathSource::Expr(..) => match def {
490 Def::StructCtor(_, CtorKind::Const) | Def::StructCtor(_, CtorKind::Fn) |
491 Def::VariantCtor(_, CtorKind::Const) | Def::VariantCtor(_, CtorKind::Fn) |
492 Def::Const(..) | Def::Static(..) | Def::Local(..) | Def::Upvar(..) |
493 Def::Fn(..) | Def::Method(..) | Def::AssociatedConst(..) => true,
496 PathSource::Pat => match def {
497 Def::StructCtor(_, CtorKind::Const) |
498 Def::VariantCtor(_, CtorKind::Const) |
499 Def::Const(..) | Def::AssociatedConst(..) => true,
502 PathSource::TupleStruct => match def {
503 Def::StructCtor(_, CtorKind::Fn) | Def::VariantCtor(_, CtorKind::Fn) => true,
506 PathSource::Struct => match def {
507 Def::Struct(..) | Def::Union(..) | Def::Variant(..) |
508 Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) => true,
511 PathSource::TraitItem(ns) => match def {
512 Def::AssociatedConst(..) | Def::Method(..) if ns == ValueNS => true,
513 Def::AssociatedTy(..) if ns == TypeNS => true,
516 PathSource::ImportPrefix => match def {
517 Def::Mod(..) | Def::Enum(..) => true,
520 PathSource::Visibility => match def {
521 Def::Mod(..) => true,
527 fn error_code(self, has_unexpected_resolution: bool) -> &'static str {
528 __diagnostic_used!(E0404);
529 __diagnostic_used!(E0405);
530 __diagnostic_used!(E0412);
531 __diagnostic_used!(E0422);
532 __diagnostic_used!(E0423);
533 __diagnostic_used!(E0425);
534 __diagnostic_used!(E0531);
535 __diagnostic_used!(E0532);
536 __diagnostic_used!(E0573);
537 __diagnostic_used!(E0574);
538 __diagnostic_used!(E0575);
539 __diagnostic_used!(E0576);
540 __diagnostic_used!(E0577);
541 __diagnostic_used!(E0578);
542 match (self, has_unexpected_resolution) {
543 (PathSource::Trait(_), true) => "E0404",
544 (PathSource::Trait(_), false) => "E0405",
545 (PathSource::Type, true) => "E0573",
546 (PathSource::Type, false) => "E0412",
547 (PathSource::Struct, true) => "E0574",
548 (PathSource::Struct, false) => "E0422",
549 (PathSource::Expr(..), true) => "E0423",
550 (PathSource::Expr(..), false) => "E0425",
551 (PathSource::Pat, true) | (PathSource::TupleStruct, true) => "E0532",
552 (PathSource::Pat, false) | (PathSource::TupleStruct, false) => "E0531",
553 (PathSource::TraitItem(..), true) => "E0575",
554 (PathSource::TraitItem(..), false) => "E0576",
555 (PathSource::Visibility, true) | (PathSource::ImportPrefix, true) => "E0577",
556 (PathSource::Visibility, false) | (PathSource::ImportPrefix, false) => "E0578",
561 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
568 #[derive(Clone, Default, Debug)]
569 pub struct PerNS<T> {
575 impl<T> ::std::ops::Index<Namespace> for PerNS<T> {
577 fn index(&self, ns: Namespace) -> &T {
579 ValueNS => &self.value_ns,
580 TypeNS => &self.type_ns,
581 MacroNS => self.macro_ns.as_ref().unwrap(),
586 impl<T> ::std::ops::IndexMut<Namespace> for PerNS<T> {
587 fn index_mut(&mut self, ns: Namespace) -> &mut T {
589 ValueNS => &mut self.value_ns,
590 TypeNS => &mut self.type_ns,
591 MacroNS => self.macro_ns.as_mut().unwrap(),
596 struct UsePlacementFinder {
597 target_module: NodeId,
602 impl UsePlacementFinder {
603 fn check(krate: &Crate, target_module: NodeId) -> (Option<Span>, bool) {
604 let mut finder = UsePlacementFinder {
609 visit::walk_crate(&mut finder, krate);
610 (finder.span, finder.found_use)
614 impl<'tcx> Visitor<'tcx> for UsePlacementFinder {
617 module: &'tcx ast::Mod,
619 _: &[ast::Attribute],
622 if self.span.is_some() {
625 if node_id != self.target_module {
626 visit::walk_mod(self, module);
629 // find a use statement
630 for item in &module.items {
632 ItemKind::Use(..) => {
633 // don't suggest placing a use before the prelude
634 // import or other generated ones
635 if item.span.ctxt().outer().expn_info().is_none() {
636 self.span = Some(item.span.with_hi(item.span.lo()));
637 self.found_use = true;
641 // don't place use before extern crate
642 ItemKind::ExternCrate(_) => {}
643 // but place them before the first other item
644 _ => if self.span.map_or(true, |span| item.span < span ) {
645 if item.span.ctxt().outer().expn_info().is_none() {
646 // don't insert between attributes and an item
647 if item.attrs.is_empty() {
648 self.span = Some(item.span.with_hi(item.span.lo()));
650 // find the first attribute on the item
651 for attr in &item.attrs {
652 if self.span.map_or(true, |span| attr.span < span) {
653 self.span = Some(attr.span.with_hi(attr.span.lo()));
664 impl<'a, 'tcx> Visitor<'tcx> for Resolver<'a> {
665 fn visit_item(&mut self, item: &'tcx Item) {
666 self.resolve_item(item);
668 fn visit_arm(&mut self, arm: &'tcx Arm) {
669 self.resolve_arm(arm);
671 fn visit_block(&mut self, block: &'tcx Block) {
672 self.resolve_block(block);
674 fn visit_expr(&mut self, expr: &'tcx Expr) {
675 self.resolve_expr(expr, None);
677 fn visit_local(&mut self, local: &'tcx Local) {
678 self.resolve_local(local);
680 fn visit_ty(&mut self, ty: &'tcx Ty) {
682 TyKind::Path(ref qself, ref path) => {
683 self.smart_resolve_path(ty.id, qself.as_ref(), path, PathSource::Type);
685 TyKind::ImplicitSelf => {
686 let self_ty = keywords::SelfType.ident();
687 let def = self.resolve_ident_in_lexical_scope(self_ty, TypeNS, true, ty.span)
688 .map_or(Def::Err, |d| d.def());
689 self.record_def(ty.id, PathResolution::new(def));
691 TyKind::Array(ref element, ref length) => {
692 self.visit_ty(element);
693 self.with_constant_rib(|this| {
694 this.visit_expr(length);
700 visit::walk_ty(self, ty);
702 fn visit_poly_trait_ref(&mut self,
703 tref: &'tcx ast::PolyTraitRef,
704 m: &'tcx ast::TraitBoundModifier) {
705 self.smart_resolve_path(tref.trait_ref.ref_id, None,
706 &tref.trait_ref.path, PathSource::Trait(AliasPossibility::Maybe));
707 visit::walk_poly_trait_ref(self, tref, m);
709 fn visit_variant(&mut self,
710 variant: &'tcx ast::Variant,
711 generics: &'tcx Generics,
712 item_id: ast::NodeId) {
713 if let Some(ref dis_expr) = variant.node.disr_expr {
714 // resolve the discriminator expr as a constant
715 self.with_constant_rib(|this| {
716 this.visit_expr(dis_expr);
720 // `visit::walk_variant` without the discriminant expression.
721 self.visit_variant_data(&variant.node.data,
727 fn visit_foreign_item(&mut self, foreign_item: &'tcx ForeignItem) {
728 let type_parameters = match foreign_item.node {
729 ForeignItemKind::Fn(_, ref generics) => {
730 HasTypeParameters(generics, ItemRibKind)
732 ForeignItemKind::Static(..) => NoTypeParameters,
733 ForeignItemKind::Ty => NoTypeParameters,
735 self.with_type_parameter_rib(type_parameters, |this| {
736 visit::walk_foreign_item(this, foreign_item);
739 fn visit_fn(&mut self,
740 function_kind: FnKind<'tcx>,
741 declaration: &'tcx FnDecl,
744 let rib_kind = match function_kind {
745 FnKind::ItemFn(..) => {
748 FnKind::Method(_, _, _, _) => {
749 TraitOrImplItemRibKind
751 FnKind::Closure(_) => ClosureRibKind(node_id),
754 // Create a value rib for the function.
755 self.ribs[ValueNS].push(Rib::new(rib_kind));
757 // Create a label rib for the function.
758 self.label_ribs.push(Rib::new(rib_kind));
760 // Add each argument to the rib.
761 let mut bindings_list = FxHashMap();
762 for argument in &declaration.inputs {
763 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
765 self.visit_ty(&argument.ty);
767 debug!("(resolving function) recorded argument");
769 visit::walk_fn_ret_ty(self, &declaration.output);
771 // Resolve the function body.
772 match function_kind {
773 FnKind::ItemFn(.., body) |
774 FnKind::Method(.., body) => {
775 self.visit_block(body);
777 FnKind::Closure(body) => {
778 self.visit_expr(body);
782 debug!("(resolving function) leaving function");
784 self.label_ribs.pop();
785 self.ribs[ValueNS].pop();
787 fn visit_generics(&mut self, generics: &'tcx Generics) {
788 // For type parameter defaults, we have to ban access
789 // to following type parameters, as the Substs can only
790 // provide previous type parameters as they're built.
791 let mut default_ban_rib = Rib::new(ForwardTyParamBanRibKind);
792 default_ban_rib.bindings.extend(generics.params.iter()
793 .filter_map(|p| if let GenericParam::Type(ref tp) = *p { Some(tp) } else { None })
794 .skip_while(|p| p.default.is_none())
795 .map(|p| (Ident::with_empty_ctxt(p.ident.name), Def::Err)));
797 for param in &generics.params {
799 GenericParam::Lifetime(_) => self.visit_generic_param(param),
800 GenericParam::Type(ref ty_param) => {
801 for bound in &ty_param.bounds {
802 self.visit_ty_param_bound(bound);
805 if let Some(ref ty) = ty_param.default {
806 self.ribs[TypeNS].push(default_ban_rib);
808 default_ban_rib = self.ribs[TypeNS].pop().unwrap();
811 // Allow all following defaults to refer to this type parameter.
812 default_ban_rib.bindings.remove(&Ident::with_empty_ctxt(ty_param.ident.name));
816 for p in &generics.where_clause.predicates { self.visit_where_predicate(p); }
820 #[derive(Copy, Clone)]
821 enum TypeParameters<'a, 'b> {
823 HasTypeParameters(// Type parameters.
826 // The kind of the rib used for type parameters.
830 // The rib kind controls the translation of local
831 // definitions (`Def::Local`) to upvars (`Def::Upvar`).
832 #[derive(Copy, Clone, Debug)]
834 // No translation needs to be applied.
837 // We passed through a closure scope at the given node ID.
838 // Translate upvars as appropriate.
839 ClosureRibKind(NodeId /* func id */),
841 // We passed through an impl or trait and are now in one of its
842 // methods or associated types. Allow references to ty params that impl or trait
843 // binds. Disallow any other upvars (including other ty params that are
845 TraitOrImplItemRibKind,
847 // We passed through an item scope. Disallow upvars.
850 // We're in a constant item. Can't refer to dynamic stuff.
853 // We passed through a module.
854 ModuleRibKind(Module<'a>),
856 // We passed through a `macro_rules!` statement
857 MacroDefinition(DefId),
859 // All bindings in this rib are type parameters that can't be used
860 // from the default of a type parameter because they're not declared
861 // before said type parameter. Also see the `visit_generics` override.
862 ForwardTyParamBanRibKind,
868 bindings: FxHashMap<Ident, Def>,
873 fn new(kind: RibKind<'a>) -> Rib<'a> {
875 bindings: FxHashMap(),
881 enum LexicalScopeBinding<'a> {
882 Item(&'a NameBinding<'a>),
886 impl<'a> LexicalScopeBinding<'a> {
887 fn item(self) -> Option<&'a NameBinding<'a>> {
889 LexicalScopeBinding::Item(binding) => Some(binding),
894 fn def(self) -> Def {
896 LexicalScopeBinding::Item(binding) => binding.def(),
897 LexicalScopeBinding::Def(def) => def,
902 #[derive(Clone, Debug)]
903 enum PathResult<'a> {
905 NonModule(PathResolution),
907 Failed(Span, String, bool /* is the error from the last segment? */),
915 /// One node in the tree of modules.
916 pub struct ModuleData<'a> {
917 parent: Option<Module<'a>>,
920 // The def id of the closest normal module (`mod`) ancestor (including this module).
921 normal_ancestor_id: DefId,
923 resolutions: RefCell<FxHashMap<(Ident, Namespace), &'a RefCell<NameResolution<'a>>>>,
924 legacy_macro_resolutions: RefCell<Vec<(Mark, Ident, Span, MacroKind)>>,
925 macro_resolutions: RefCell<Vec<(Box<[Ident]>, Span)>>,
927 // Macro invocations that can expand into items in this module.
928 unresolved_invocations: RefCell<FxHashSet<Mark>>,
930 no_implicit_prelude: bool,
932 glob_importers: RefCell<Vec<&'a ImportDirective<'a>>>,
933 globs: RefCell<Vec<&'a ImportDirective<'a>>>,
935 // Used to memoize the traits in this module for faster searches through all traits in scope.
936 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
938 // Whether this module is populated. If not populated, any attempt to
939 // access the children must be preceded with a
940 // `populate_module_if_necessary` call.
941 populated: Cell<bool>,
943 /// Span of the module itself. Used for error reporting.
949 type Module<'a> = &'a ModuleData<'a>;
951 impl<'a> ModuleData<'a> {
952 fn new(parent: Option<Module<'a>>,
954 normal_ancestor_id: DefId,
956 span: Span) -> Self {
961 resolutions: RefCell::new(FxHashMap()),
962 legacy_macro_resolutions: RefCell::new(Vec::new()),
963 macro_resolutions: RefCell::new(Vec::new()),
964 unresolved_invocations: RefCell::new(FxHashSet()),
965 no_implicit_prelude: false,
966 glob_importers: RefCell::new(Vec::new()),
967 globs: RefCell::new(Vec::new()),
968 traits: RefCell::new(None),
969 populated: Cell::new(normal_ancestor_id.is_local()),
975 fn for_each_child<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
976 for (&(ident, ns), name_resolution) in self.resolutions.borrow().iter() {
977 name_resolution.borrow().binding.map(|binding| f(ident, ns, binding));
981 fn for_each_child_stable<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
982 let resolutions = self.resolutions.borrow();
983 let mut resolutions = resolutions.iter().map(|(&(ident, ns), &resolution)| {
984 // Pre-compute keys for sorting
985 (ident.name.as_str(), ns, ident, resolution)
987 .collect::<Vec<_>>();
988 resolutions.sort_unstable_by_key(|&(str, ns, ..)| (str, ns));
989 for &(_, ns, ident, resolution) in resolutions.iter() {
990 resolution.borrow().binding.map(|binding| f(ident, ns, binding));
994 fn def(&self) -> Option<Def> {
996 ModuleKind::Def(def, _) => Some(def),
1001 fn def_id(&self) -> Option<DefId> {
1002 self.def().as_ref().map(Def::def_id)
1005 // `self` resolves to the first module ancestor that `is_normal`.
1006 fn is_normal(&self) -> bool {
1008 ModuleKind::Def(Def::Mod(_), _) => true,
1013 fn is_trait(&self) -> bool {
1015 ModuleKind::Def(Def::Trait(_), _) => true,
1020 fn is_local(&self) -> bool {
1021 self.normal_ancestor_id.is_local()
1024 fn nearest_item_scope(&'a self) -> Module<'a> {
1025 if self.is_trait() { self.parent.unwrap() } else { self }
1029 impl<'a> fmt::Debug for ModuleData<'a> {
1030 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1031 write!(f, "{:?}", self.def())
1035 // Records a possibly-private value, type, or module definition.
1036 #[derive(Clone, Debug)]
1037 pub struct NameBinding<'a> {
1038 kind: NameBindingKind<'a>,
1041 vis: ty::Visibility,
1044 pub trait ToNameBinding<'a> {
1045 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
1048 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
1049 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
1054 #[derive(Clone, Debug)]
1055 enum NameBindingKind<'a> {
1059 binding: &'a NameBinding<'a>,
1060 directive: &'a ImportDirective<'a>,
1062 legacy_self_import: bool,
1065 b1: &'a NameBinding<'a>,
1066 b2: &'a NameBinding<'a>,
1071 struct PrivacyError<'a>(Span, Name, &'a NameBinding<'a>);
1073 struct UseError<'a> {
1074 err: DiagnosticBuilder<'a>,
1075 /// Attach `use` statements for these candidates
1076 candidates: Vec<ImportSuggestion>,
1077 /// The node id of the module to place the use statements in
1079 /// Whether the diagnostic should state that it's "better"
1083 struct AmbiguityError<'a> {
1087 b1: &'a NameBinding<'a>,
1088 b2: &'a NameBinding<'a>,
1092 impl<'a> NameBinding<'a> {
1093 fn module(&self) -> Option<Module<'a>> {
1095 NameBindingKind::Module(module) => Some(module),
1096 NameBindingKind::Import { binding, .. } => binding.module(),
1097 NameBindingKind::Ambiguity { legacy: true, b1, .. } => b1.module(),
1102 fn def(&self) -> Def {
1104 NameBindingKind::Def(def) => def,
1105 NameBindingKind::Module(module) => module.def().unwrap(),
1106 NameBindingKind::Import { binding, .. } => binding.def(),
1107 NameBindingKind::Ambiguity { legacy: true, b1, .. } => b1.def(),
1108 NameBindingKind::Ambiguity { .. } => Def::Err,
1112 fn def_ignoring_ambiguity(&self) -> Def {
1114 NameBindingKind::Import { binding, .. } => binding.def_ignoring_ambiguity(),
1115 NameBindingKind::Ambiguity { b1, .. } => b1.def_ignoring_ambiguity(),
1120 fn get_macro(&self, resolver: &mut Resolver<'a>) -> Rc<SyntaxExtension> {
1121 resolver.get_macro(self.def_ignoring_ambiguity())
1124 // We sometimes need to treat variants as `pub` for backwards compatibility
1125 fn pseudo_vis(&self) -> ty::Visibility {
1126 if self.is_variant() && self.def().def_id().is_local() {
1127 ty::Visibility::Public
1133 fn is_variant(&self) -> bool {
1135 NameBindingKind::Def(Def::Variant(..)) |
1136 NameBindingKind::Def(Def::VariantCtor(..)) => true,
1141 fn is_extern_crate(&self) -> bool {
1143 NameBindingKind::Import {
1144 directive: &ImportDirective {
1145 subclass: ImportDirectiveSubclass::ExternCrate(_), ..
1152 fn is_import(&self) -> bool {
1154 NameBindingKind::Import { .. } => true,
1159 fn is_renamed_extern_crate(&self) -> bool {
1160 if let NameBindingKind::Import { directive, ..} = self.kind {
1161 if let ImportDirectiveSubclass::ExternCrate(Some(_)) = directive.subclass {
1168 fn is_glob_import(&self) -> bool {
1170 NameBindingKind::Import { directive, .. } => directive.is_glob(),
1171 NameBindingKind::Ambiguity { b1, .. } => b1.is_glob_import(),
1176 fn is_importable(&self) -> bool {
1178 Def::AssociatedConst(..) | Def::Method(..) | Def::AssociatedTy(..) => false,
1183 fn is_macro_def(&self) -> bool {
1185 NameBindingKind::Def(Def::Macro(..)) => true,
1190 fn descr(&self) -> &'static str {
1191 if self.is_extern_crate() { "extern crate" } else { self.def().kind_name() }
1195 /// Interns the names of the primitive types.
1196 struct PrimitiveTypeTable {
1197 primitive_types: FxHashMap<Name, PrimTy>,
1200 impl PrimitiveTypeTable {
1201 fn new() -> PrimitiveTypeTable {
1202 let mut table = PrimitiveTypeTable { primitive_types: FxHashMap() };
1204 table.intern("bool", TyBool);
1205 table.intern("char", TyChar);
1206 table.intern("f32", TyFloat(FloatTy::F32));
1207 table.intern("f64", TyFloat(FloatTy::F64));
1208 table.intern("isize", TyInt(IntTy::Isize));
1209 table.intern("i8", TyInt(IntTy::I8));
1210 table.intern("i16", TyInt(IntTy::I16));
1211 table.intern("i32", TyInt(IntTy::I32));
1212 table.intern("i64", TyInt(IntTy::I64));
1213 table.intern("i128", TyInt(IntTy::I128));
1214 table.intern("str", TyStr);
1215 table.intern("usize", TyUint(UintTy::Usize));
1216 table.intern("u8", TyUint(UintTy::U8));
1217 table.intern("u16", TyUint(UintTy::U16));
1218 table.intern("u32", TyUint(UintTy::U32));
1219 table.intern("u64", TyUint(UintTy::U64));
1220 table.intern("u128", TyUint(UintTy::U128));
1224 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1225 self.primitive_types.insert(Symbol::intern(string), primitive_type);
1229 /// The main resolver class.
1230 pub struct Resolver<'a> {
1231 session: &'a Session,
1232 cstore: &'a CrateStore,
1234 pub definitions: Definitions,
1236 graph_root: Module<'a>,
1238 prelude: Option<Module<'a>>,
1240 // n.b. This is used only for better diagnostics, not name resolution itself.
1241 has_self: FxHashSet<DefId>,
1243 // Names of fields of an item `DefId` accessible with dot syntax.
1244 // Used for hints during error reporting.
1245 field_names: FxHashMap<DefId, Vec<Name>>,
1247 // All imports known to succeed or fail.
1248 determined_imports: Vec<&'a ImportDirective<'a>>,
1250 // All non-determined imports.
1251 indeterminate_imports: Vec<&'a ImportDirective<'a>>,
1253 // The module that represents the current item scope.
1254 current_module: Module<'a>,
1256 // The current set of local scopes for types and values.
1257 // FIXME #4948: Reuse ribs to avoid allocation.
1258 ribs: PerNS<Vec<Rib<'a>>>,
1260 // The current set of local scopes, for labels.
1261 label_ribs: Vec<Rib<'a>>,
1263 // The trait that the current context can refer to.
1264 current_trait_ref: Option<(Module<'a>, TraitRef)>,
1266 // The current self type if inside an impl (used for better errors).
1267 current_self_type: Option<Ty>,
1269 // The idents for the primitive types.
1270 primitive_type_table: PrimitiveTypeTable,
1273 pub freevars: FreevarMap,
1274 freevars_seen: NodeMap<NodeMap<usize>>,
1275 pub export_map: ExportMap,
1276 pub trait_map: TraitMap,
1278 // A map from nodes to anonymous modules.
1279 // Anonymous modules are pseudo-modules that are implicitly created around items
1280 // contained within blocks.
1282 // For example, if we have this:
1290 // There will be an anonymous module created around `g` with the ID of the
1291 // entry block for `f`.
1292 block_map: NodeMap<Module<'a>>,
1293 module_map: FxHashMap<DefId, Module<'a>>,
1294 extern_module_map: FxHashMap<(DefId, bool /* MacrosOnly? */), Module<'a>>,
1296 pub make_glob_map: bool,
1297 /// Maps imports to the names of items actually imported (this actually maps
1298 /// all imports, but only glob imports are actually interesting).
1299 pub glob_map: GlobMap,
1301 used_imports: FxHashSet<(NodeId, Namespace)>,
1302 pub maybe_unused_trait_imports: NodeSet,
1303 pub maybe_unused_extern_crates: Vec<(NodeId, Span)>,
1305 /// privacy errors are delayed until the end in order to deduplicate them
1306 privacy_errors: Vec<PrivacyError<'a>>,
1307 /// ambiguity errors are delayed for deduplication
1308 ambiguity_errors: Vec<AmbiguityError<'a>>,
1309 /// `use` injections are delayed for better placement and deduplication
1310 use_injections: Vec<UseError<'a>>,
1311 /// `use` injections for proc macros wrongly imported with #[macro_use]
1312 proc_mac_errors: Vec<macros::ProcMacError>,
1314 gated_errors: FxHashSet<Span>,
1315 disallowed_shadowing: Vec<&'a LegacyBinding<'a>>,
1317 arenas: &'a ResolverArenas<'a>,
1318 dummy_binding: &'a NameBinding<'a>,
1319 use_extern_macros: bool, // true if `#![feature(use_extern_macros)]`
1321 crate_loader: &'a mut CrateLoader,
1322 macro_names: FxHashSet<Ident>,
1323 global_macros: FxHashMap<Name, &'a NameBinding<'a>>,
1324 pub all_macros: FxHashMap<Name, Def>,
1325 lexical_macro_resolutions: Vec<(Ident, &'a Cell<LegacyScope<'a>>)>,
1326 macro_map: FxHashMap<DefId, Rc<SyntaxExtension>>,
1327 macro_defs: FxHashMap<Mark, DefId>,
1328 local_macro_def_scopes: FxHashMap<NodeId, Module<'a>>,
1329 macro_exports: Vec<Export>,
1330 pub whitelisted_legacy_custom_derives: Vec<Name>,
1331 pub found_unresolved_macro: bool,
1333 // List of crate local macros that we need to warn about as being unused.
1334 // Right now this only includes macro_rules! macros, and macros 2.0.
1335 unused_macros: FxHashSet<DefId>,
1337 // Maps the `Mark` of an expansion to its containing module or block.
1338 invocations: FxHashMap<Mark, &'a InvocationData<'a>>,
1340 // Avoid duplicated errors for "name already defined".
1341 name_already_seen: FxHashMap<Name, Span>,
1343 // If `#![feature(proc_macro)]` is set
1344 proc_macro_enabled: bool,
1346 // A set of procedural macros imported by `#[macro_use]` that have already been warned about
1347 warned_proc_macros: FxHashSet<Name>,
1349 potentially_unused_imports: Vec<&'a ImportDirective<'a>>,
1351 // This table maps struct IDs into struct constructor IDs,
1352 // it's not used during normal resolution, only for better error reporting.
1353 struct_constructors: DefIdMap<(Def, ty::Visibility)>,
1355 // Only used for better errors on `fn(): fn()`
1356 current_type_ascription: Vec<Span>,
1358 injected_crate: Option<Module<'a>>,
1361 pub struct ResolverArenas<'a> {
1362 modules: arena::TypedArena<ModuleData<'a>>,
1363 local_modules: RefCell<Vec<Module<'a>>>,
1364 name_bindings: arena::TypedArena<NameBinding<'a>>,
1365 import_directives: arena::TypedArena<ImportDirective<'a>>,
1366 name_resolutions: arena::TypedArena<RefCell<NameResolution<'a>>>,
1367 invocation_data: arena::TypedArena<InvocationData<'a>>,
1368 legacy_bindings: arena::TypedArena<LegacyBinding<'a>>,
1371 impl<'a> ResolverArenas<'a> {
1372 fn alloc_module(&'a self, module: ModuleData<'a>) -> Module<'a> {
1373 let module = self.modules.alloc(module);
1374 if module.def_id().map(|def_id| def_id.is_local()).unwrap_or(true) {
1375 self.local_modules.borrow_mut().push(module);
1379 fn local_modules(&'a self) -> ::std::cell::Ref<'a, Vec<Module<'a>>> {
1380 self.local_modules.borrow()
1382 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1383 self.name_bindings.alloc(name_binding)
1385 fn alloc_import_directive(&'a self, import_directive: ImportDirective<'a>)
1386 -> &'a ImportDirective {
1387 self.import_directives.alloc(import_directive)
1389 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1390 self.name_resolutions.alloc(Default::default())
1392 fn alloc_invocation_data(&'a self, expansion_data: InvocationData<'a>)
1393 -> &'a InvocationData<'a> {
1394 self.invocation_data.alloc(expansion_data)
1396 fn alloc_legacy_binding(&'a self, binding: LegacyBinding<'a>) -> &'a LegacyBinding<'a> {
1397 self.legacy_bindings.alloc(binding)
1401 impl<'a, 'b: 'a> ty::DefIdTree for &'a Resolver<'b> {
1402 fn parent(self, id: DefId) -> Option<DefId> {
1404 LOCAL_CRATE => self.definitions.def_key(id.index).parent,
1405 _ => self.cstore.def_key(id).parent,
1406 }.map(|index| DefId { index: index, ..id })
1410 impl<'a> hir::lowering::Resolver for Resolver<'a> {
1411 fn resolve_hir_path(&mut self, path: &mut hir::Path, is_value: bool) {
1412 self.resolve_hir_path_cb(path, is_value,
1413 |resolver, span, error| resolve_error(resolver, span, error))
1416 fn resolve_str_path(&mut self, span: Span, crate_root: Option<&str>,
1417 components: &[&str], is_value: bool) -> hir::Path {
1418 let mut path = hir::Path {
1421 segments: iter::once(keywords::CrateRoot.name()).chain({
1422 crate_root.into_iter().chain(components.iter().cloned()).map(Symbol::intern)
1423 }).map(hir::PathSegment::from_name).collect(),
1426 self.resolve_hir_path(&mut path, is_value);
1430 fn get_resolution(&mut self, id: NodeId) -> Option<PathResolution> {
1431 self.def_map.get(&id).cloned()
1434 fn definitions(&mut self) -> &mut Definitions {
1435 &mut self.definitions
1439 impl<'a> Resolver<'a> {
1440 /// Rustdoc uses this to resolve things in a recoverable way. ResolutionError<'a>
1441 /// isn't something that can be returned because it can't be made to live that long,
1442 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
1443 /// just that an error occured.
1444 pub fn resolve_str_path_error(&mut self, span: Span, path_str: &str, is_value: bool)
1445 -> Result<hir::Path, ()> {
1447 let mut errored = false;
1449 let mut path = if path_str.starts_with("::") {
1453 segments: iter::once(keywords::CrateRoot.name()).chain({
1454 path_str.split("::").skip(1).map(Symbol::intern)
1455 }).map(hir::PathSegment::from_name).collect(),
1461 segments: path_str.split("::").map(Symbol::intern)
1462 .map(hir::PathSegment::from_name).collect(),
1465 self.resolve_hir_path_cb(&mut path, is_value, |_, _, _| errored = true);
1466 if errored || path.def == Def::Err {
1473 /// resolve_hir_path, but takes a callback in case there was an error
1474 fn resolve_hir_path_cb<F>(&mut self, path: &mut hir::Path, is_value: bool, error_callback: F)
1475 where F: for<'c, 'b> FnOnce(&'c mut Resolver, Span, ResolutionError<'b>)
1477 let namespace = if is_value { ValueNS } else { TypeNS };
1478 let hir::Path { ref segments, span, ref mut def } = *path;
1479 let path: Vec<SpannedIdent> = segments.iter()
1480 .map(|seg| respan(span, Ident::with_empty_ctxt(seg.name)))
1482 match self.resolve_path(&path, Some(namespace), true, span) {
1483 PathResult::Module(module) => *def = module.def().unwrap(),
1484 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 =>
1485 *def = path_res.base_def(),
1486 PathResult::NonModule(..) => match self.resolve_path(&path, None, true, span) {
1487 PathResult::Failed(span, msg, _) => {
1488 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1492 PathResult::Indeterminate => unreachable!(),
1493 PathResult::Failed(span, msg, _) => {
1494 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
1500 impl<'a> Resolver<'a> {
1501 pub fn new(session: &'a Session,
1502 cstore: &'a CrateStore,
1505 make_glob_map: MakeGlobMap,
1506 crate_loader: &'a mut CrateLoader,
1507 arenas: &'a ResolverArenas<'a>)
1509 let root_def_id = DefId::local(CRATE_DEF_INDEX);
1510 let root_module_kind = ModuleKind::Def(Def::Mod(root_def_id), keywords::Invalid.name());
1511 let graph_root = arenas.alloc_module(ModuleData {
1512 no_implicit_prelude: attr::contains_name(&krate.attrs, "no_implicit_prelude"),
1513 ..ModuleData::new(None, root_module_kind, root_def_id, Mark::root(), krate.span)
1515 let mut module_map = FxHashMap();
1516 module_map.insert(DefId::local(CRATE_DEF_INDEX), graph_root);
1518 let mut definitions = Definitions::new();
1519 DefCollector::new(&mut definitions, Mark::root())
1520 .collect_root(crate_name, session.local_crate_disambiguator());
1522 let mut invocations = FxHashMap();
1523 invocations.insert(Mark::root(),
1524 arenas.alloc_invocation_data(InvocationData::root(graph_root)));
1526 let features = session.features.borrow();
1528 let mut macro_defs = FxHashMap();
1529 macro_defs.insert(Mark::root(), root_def_id);
1538 // The outermost module has def ID 0; this is not reflected in the
1543 has_self: FxHashSet(),
1544 field_names: FxHashMap(),
1546 determined_imports: Vec::new(),
1547 indeterminate_imports: Vec::new(),
1549 current_module: graph_root,
1551 value_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1552 type_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1553 macro_ns: Some(vec![Rib::new(ModuleRibKind(graph_root))]),
1555 label_ribs: Vec::new(),
1557 current_trait_ref: None,
1558 current_self_type: None,
1560 primitive_type_table: PrimitiveTypeTable::new(),
1563 freevars: NodeMap(),
1564 freevars_seen: NodeMap(),
1565 export_map: FxHashMap(),
1566 trait_map: NodeMap(),
1568 block_map: NodeMap(),
1569 extern_module_map: FxHashMap(),
1571 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1572 glob_map: NodeMap(),
1574 used_imports: FxHashSet(),
1575 maybe_unused_trait_imports: NodeSet(),
1576 maybe_unused_extern_crates: Vec::new(),
1578 privacy_errors: Vec::new(),
1579 ambiguity_errors: Vec::new(),
1580 use_injections: Vec::new(),
1581 proc_mac_errors: Vec::new(),
1582 gated_errors: FxHashSet(),
1583 disallowed_shadowing: Vec::new(),
1586 dummy_binding: arenas.alloc_name_binding(NameBinding {
1587 kind: NameBindingKind::Def(Def::Err),
1588 expansion: Mark::root(),
1590 vis: ty::Visibility::Public,
1593 // The `proc_macro` and `decl_macro` features imply `use_extern_macros`
1595 features.use_extern_macros || features.proc_macro || features.decl_macro,
1598 macro_names: FxHashSet(),
1599 global_macros: FxHashMap(),
1600 all_macros: FxHashMap(),
1601 lexical_macro_resolutions: Vec::new(),
1602 macro_map: FxHashMap(),
1603 macro_exports: Vec::new(),
1606 local_macro_def_scopes: FxHashMap(),
1607 name_already_seen: FxHashMap(),
1608 whitelisted_legacy_custom_derives: Vec::new(),
1609 proc_macro_enabled: features.proc_macro,
1610 warned_proc_macros: FxHashSet(),
1611 potentially_unused_imports: Vec::new(),
1612 struct_constructors: DefIdMap(),
1613 found_unresolved_macro: false,
1614 unused_macros: FxHashSet(),
1615 current_type_ascription: Vec::new(),
1616 injected_crate: None,
1620 pub fn arenas() -> ResolverArenas<'a> {
1622 modules: arena::TypedArena::new(),
1623 local_modules: RefCell::new(Vec::new()),
1624 name_bindings: arena::TypedArena::new(),
1625 import_directives: arena::TypedArena::new(),
1626 name_resolutions: arena::TypedArena::new(),
1627 invocation_data: arena::TypedArena::new(),
1628 legacy_bindings: arena::TypedArena::new(),
1632 fn per_ns<T, F: FnMut(&mut Self, Namespace) -> T>(&mut self, mut f: F) -> PerNS<T> {
1634 type_ns: f(self, TypeNS),
1635 value_ns: f(self, ValueNS),
1636 macro_ns: match self.use_extern_macros {
1637 true => Some(f(self, MacroNS)),
1643 fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
1645 match self.macro_defs.get(&ctxt.outer()) {
1646 Some(&def_id) => return def_id,
1647 None => ctxt.remove_mark(),
1652 /// Entry point to crate resolution.
1653 pub fn resolve_crate(&mut self, krate: &Crate) {
1654 ImportResolver { resolver: self }.finalize_imports();
1655 self.current_module = self.graph_root;
1656 self.finalize_current_module_macro_resolutions();
1658 visit::walk_crate(self, krate);
1660 check_unused::check_crate(self, krate);
1661 self.report_errors(krate);
1662 self.crate_loader.postprocess(krate);
1669 normal_ancestor_id: DefId,
1673 let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expansion, span);
1674 self.arenas.alloc_module(module)
1677 fn record_use(&mut self, ident: Ident, ns: Namespace, binding: &'a NameBinding<'a>, span: Span)
1678 -> bool /* true if an error was reported */ {
1679 match binding.kind {
1680 NameBindingKind::Import { directive, binding, ref used, legacy_self_import }
1683 directive.used.set(true);
1684 if legacy_self_import {
1685 self.warn_legacy_self_import(directive);
1688 self.used_imports.insert((directive.id, ns));
1689 self.add_to_glob_map(directive.id, ident);
1690 self.record_use(ident, ns, binding, span)
1692 NameBindingKind::Import { .. } => false,
1693 NameBindingKind::Ambiguity { b1, b2, legacy } => {
1694 self.ambiguity_errors.push(AmbiguityError {
1695 span: span, name: ident.name, lexical: false, b1: b1, b2: b2, legacy,
1698 self.record_use(ident, ns, b1, span);
1706 fn add_to_glob_map(&mut self, id: NodeId, ident: Ident) {
1707 if self.make_glob_map {
1708 self.glob_map.entry(id).or_insert_with(FxHashSet).insert(ident.name);
1712 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1713 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1714 /// `ident` in the first scope that defines it (or None if no scopes define it).
1716 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1717 /// the items are defined in the block. For example,
1720 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1723 /// g(); // This resolves to the local variable `g` since it shadows the item.
1727 /// Invariant: This must only be called during main resolution, not during
1728 /// import resolution.
1729 fn resolve_ident_in_lexical_scope(&mut self,
1734 -> Option<LexicalScopeBinding<'a>> {
1736 ident.ctxt = if ident.name == keywords::SelfType.name() {
1737 SyntaxContext::empty() // FIXME(jseyfried) improve `Self` hygiene
1743 // Walk backwards up the ribs in scope.
1744 let mut module = self.graph_root;
1745 for i in (0 .. self.ribs[ns].len()).rev() {
1746 if let Some(def) = self.ribs[ns][i].bindings.get(&ident).cloned() {
1747 // The ident resolves to a type parameter or local variable.
1748 return Some(LexicalScopeBinding::Def(
1749 self.adjust_local_def(ns, i, def, record_used, path_span)
1753 module = match self.ribs[ns][i].kind {
1754 ModuleRibKind(module) => module,
1755 MacroDefinition(def) if def == self.macro_def(ident.ctxt) => {
1756 // If an invocation of this macro created `ident`, give up on `ident`
1757 // and switch to `ident`'s source from the macro definition.
1758 ident.ctxt.remove_mark();
1764 let item = self.resolve_ident_in_module_unadjusted(
1765 module, ident, ns, false, record_used, path_span,
1767 if let Ok(binding) = item {
1768 // The ident resolves to an item.
1769 return Some(LexicalScopeBinding::Item(binding));
1773 ModuleKind::Block(..) => {}, // We can see through blocks
1778 ident.ctxt = ident.ctxt.modern();
1780 module = unwrap_or!(self.hygienic_lexical_parent(module, &mut ident.ctxt), break);
1781 let orig_current_module = self.current_module;
1782 self.current_module = module; // Lexical resolutions can never be a privacy error.
1783 let result = self.resolve_ident_in_module_unadjusted(
1784 module, ident, ns, false, record_used, path_span,
1786 self.current_module = orig_current_module;
1789 Ok(binding) => return Some(LexicalScopeBinding::Item(binding)),
1790 Err(Undetermined) => return None,
1791 Err(Determined) => {}
1795 match self.prelude {
1796 Some(prelude) if !module.no_implicit_prelude => {
1797 self.resolve_ident_in_module_unadjusted(prelude, ident, ns, false, false, path_span)
1798 .ok().map(LexicalScopeBinding::Item)
1804 fn hygienic_lexical_parent(&mut self, mut module: Module<'a>, ctxt: &mut SyntaxContext)
1805 -> Option<Module<'a>> {
1806 if !module.expansion.is_descendant_of(ctxt.outer()) {
1807 return Some(self.macro_def_scope(ctxt.remove_mark()));
1810 if let ModuleKind::Block(..) = module.kind {
1811 return Some(module.parent.unwrap());
1814 let mut module_expansion = module.expansion.modern(); // for backward compatibility
1815 while let Some(parent) = module.parent {
1816 let parent_expansion = parent.expansion.modern();
1817 if module_expansion.is_descendant_of(parent_expansion) &&
1818 parent_expansion != module_expansion {
1819 return if parent_expansion.is_descendant_of(ctxt.outer()) {
1826 module_expansion = parent_expansion;
1832 fn resolve_ident_in_module(&mut self,
1836 ignore_unresolved_invocations: bool,
1839 -> Result<&'a NameBinding<'a>, Determinacy> {
1840 ident.ctxt = ident.ctxt.modern();
1841 let orig_current_module = self.current_module;
1842 if let Some(def) = ident.ctxt.adjust(module.expansion) {
1843 self.current_module = self.macro_def_scope(def);
1845 let result = self.resolve_ident_in_module_unadjusted(
1846 module, ident, ns, ignore_unresolved_invocations, record_used, span,
1848 self.current_module = orig_current_module;
1852 fn resolve_crate_root(&mut self, mut ctxt: SyntaxContext, legacy: bool) -> Module<'a> {
1853 let mark = if legacy {
1854 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
1855 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
1856 // as described in `SyntaxContext::apply_mark`, so we ignore prepended modern marks.
1857 ctxt.marks().into_iter().find(|&mark| mark.kind() != MarkKind::Modern)
1859 ctxt = ctxt.modern();
1860 ctxt.adjust(Mark::root())
1862 let module = match mark {
1863 Some(def) => self.macro_def_scope(def),
1864 None => return self.graph_root,
1866 self.get_module(DefId { index: CRATE_DEF_INDEX, ..module.normal_ancestor_id })
1869 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
1870 let mut module = self.get_module(module.normal_ancestor_id);
1871 while module.span.ctxt().modern() != *ctxt {
1872 let parent = module.parent.unwrap_or_else(|| self.macro_def_scope(ctxt.remove_mark()));
1873 module = self.get_module(parent.normal_ancestor_id);
1880 // We maintain a list of value ribs and type ribs.
1882 // Simultaneously, we keep track of the current position in the module
1883 // graph in the `current_module` pointer. When we go to resolve a name in
1884 // the value or type namespaces, we first look through all the ribs and
1885 // then query the module graph. When we resolve a name in the module
1886 // namespace, we can skip all the ribs (since nested modules are not
1887 // allowed within blocks in Rust) and jump straight to the current module
1890 // Named implementations are handled separately. When we find a method
1891 // call, we consult the module node to find all of the implementations in
1892 // scope. This information is lazily cached in the module node. We then
1893 // generate a fake "implementation scope" containing all the
1894 // implementations thus found, for compatibility with old resolve pass.
1896 pub fn with_scope<F, T>(&mut self, id: NodeId, f: F) -> T
1897 where F: FnOnce(&mut Resolver) -> T
1899 let id = self.definitions.local_def_id(id);
1900 let module = self.module_map.get(&id).cloned(); // clones a reference
1901 if let Some(module) = module {
1902 // Move down in the graph.
1903 let orig_module = replace(&mut self.current_module, module);
1904 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(module)));
1905 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(module)));
1907 self.finalize_current_module_macro_resolutions();
1910 self.current_module = orig_module;
1911 self.ribs[ValueNS].pop();
1912 self.ribs[TypeNS].pop();
1919 /// Searches the current set of local scopes for labels. Returns the first non-None label that
1920 /// is returned by the given predicate function
1922 /// Stops after meeting a closure.
1923 fn search_label<P, R>(&self, mut ident: Ident, pred: P) -> Option<R>
1924 where P: Fn(&Rib, Ident) -> Option<R>
1926 for rib in self.label_ribs.iter().rev() {
1929 // If an invocation of this macro created `ident`, give up on `ident`
1930 // and switch to `ident`'s source from the macro definition.
1931 MacroDefinition(def) => {
1932 if def == self.macro_def(ident.ctxt) {
1933 ident.ctxt.remove_mark();
1937 // Do not resolve labels across function boundary
1941 let r = pred(rib, ident);
1949 fn resolve_item(&mut self, item: &Item) {
1950 let name = item.ident.name;
1952 debug!("(resolving item) resolving {}", name);
1954 self.check_proc_macro_attrs(&item.attrs);
1957 ItemKind::Enum(_, ref generics) |
1958 ItemKind::Ty(_, ref generics) |
1959 ItemKind::Struct(_, ref generics) |
1960 ItemKind::Union(_, ref generics) |
1961 ItemKind::Fn(.., ref generics, _) => {
1962 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind),
1963 |this| visit::walk_item(this, item));
1966 ItemKind::Impl(.., ref generics, ref opt_trait_ref, ref self_type, ref impl_items) =>
1967 self.resolve_implementation(generics,
1973 ItemKind::Trait(.., ref generics, ref bounds, ref trait_items) => {
1974 // Create a new rib for the trait-wide type parameters.
1975 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
1976 let local_def_id = this.definitions.local_def_id(item.id);
1977 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
1978 this.visit_generics(generics);
1979 walk_list!(this, visit_ty_param_bound, bounds);
1981 for trait_item in trait_items {
1982 this.check_proc_macro_attrs(&trait_item.attrs);
1984 let type_parameters = HasTypeParameters(&trait_item.generics,
1985 TraitOrImplItemRibKind);
1986 this.with_type_parameter_rib(type_parameters, |this| {
1987 match trait_item.node {
1988 TraitItemKind::Const(ref ty, ref default) => {
1991 // Only impose the restrictions of
1992 // ConstRibKind for an actual constant
1993 // expression in a provided default.
1994 if let Some(ref expr) = *default{
1995 this.with_constant_rib(|this| {
1996 this.visit_expr(expr);
2000 TraitItemKind::Method(_, _) => {
2001 visit::walk_trait_item(this, trait_item)
2003 TraitItemKind::Type(..) => {
2004 visit::walk_trait_item(this, trait_item)
2006 TraitItemKind::Macro(_) => {
2007 panic!("unexpanded macro in resolve!")
2016 ItemKind::TraitAlias(ref generics, ref bounds) => {
2017 // Create a new rib for the trait-wide type parameters.
2018 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2019 let local_def_id = this.definitions.local_def_id(item.id);
2020 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
2021 this.visit_generics(generics);
2022 walk_list!(this, visit_ty_param_bound, bounds);
2027 ItemKind::Mod(_) | ItemKind::ForeignMod(_) => {
2028 self.with_scope(item.id, |this| {
2029 visit::walk_item(this, item);
2033 ItemKind::Static(ref ty, _, ref expr) |
2034 ItemKind::Const(ref ty, ref expr) => {
2035 self.with_item_rib(|this| {
2037 this.with_constant_rib(|this| {
2038 this.visit_expr(expr);
2043 ItemKind::Use(ref use_tree) => {
2046 span: use_tree.span,
2048 self.resolve_use_tree(item.id, use_tree, &path);
2051 ItemKind::ExternCrate(_) | ItemKind::MacroDef(..) | ItemKind::GlobalAsm(_) => {
2052 // do nothing, these are just around to be encoded
2055 ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"),
2059 fn resolve_use_tree(&mut self, id: NodeId, use_tree: &ast::UseTree, prefix: &Path) {
2060 match use_tree.kind {
2061 ast::UseTreeKind::Nested(ref items) => {
2063 segments: prefix.segments
2065 .chain(use_tree.prefix.segments.iter())
2068 span: prefix.span.to(use_tree.prefix.span),
2071 if items.len() == 0 {
2072 // Resolve prefix of an import with empty braces (issue #28388).
2073 self.smart_resolve_path(id, None, &path, PathSource::ImportPrefix);
2075 for &(ref tree, nested_id) in items {
2076 self.resolve_use_tree(nested_id, tree, &path);
2080 ast::UseTreeKind::Simple(_) => {},
2081 ast::UseTreeKind::Glob => {},
2085 fn with_type_parameter_rib<'b, F>(&'b mut self, type_parameters: TypeParameters<'a, 'b>, f: F)
2086 where F: FnOnce(&mut Resolver)
2088 match type_parameters {
2089 HasTypeParameters(generics, rib_kind) => {
2090 let mut function_type_rib = Rib::new(rib_kind);
2091 let mut seen_bindings = FxHashMap();
2092 for param in &generics.params {
2093 if let GenericParam::Type(ref type_parameter) = *param {
2094 let ident = type_parameter.ident.modern();
2095 debug!("with_type_parameter_rib: {}", type_parameter.id);
2097 if seen_bindings.contains_key(&ident) {
2098 let span = seen_bindings.get(&ident).unwrap();
2099 let err = ResolutionError::NameAlreadyUsedInTypeParameterList(
2103 resolve_error(self, type_parameter.span, err);
2105 seen_bindings.entry(ident).or_insert(type_parameter.span);
2107 // plain insert (no renaming)
2108 let def_id = self.definitions.local_def_id(type_parameter.id);
2109 let def = Def::TyParam(def_id);
2110 function_type_rib.bindings.insert(ident, def);
2111 self.record_def(type_parameter.id, PathResolution::new(def));
2114 self.ribs[TypeNS].push(function_type_rib);
2117 NoTypeParameters => {
2124 if let HasTypeParameters(..) = type_parameters {
2125 self.ribs[TypeNS].pop();
2129 fn with_label_rib<F>(&mut self, f: F)
2130 where F: FnOnce(&mut Resolver)
2132 self.label_ribs.push(Rib::new(NormalRibKind));
2134 self.label_ribs.pop();
2137 fn with_item_rib<F>(&mut self, f: F)
2138 where F: FnOnce(&mut Resolver)
2140 self.ribs[ValueNS].push(Rib::new(ItemRibKind));
2141 self.ribs[TypeNS].push(Rib::new(ItemRibKind));
2143 self.ribs[TypeNS].pop();
2144 self.ribs[ValueNS].pop();
2147 fn with_constant_rib<F>(&mut self, f: F)
2148 where F: FnOnce(&mut Resolver)
2150 self.ribs[ValueNS].push(Rib::new(ConstantItemRibKind));
2152 self.ribs[ValueNS].pop();
2155 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
2156 where F: FnOnce(&mut Resolver) -> T
2158 // Handle nested impls (inside fn bodies)
2159 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
2160 let result = f(self);
2161 self.current_self_type = previous_value;
2165 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
2166 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
2168 let mut new_val = None;
2169 let mut new_id = None;
2170 if let Some(trait_ref) = opt_trait_ref {
2171 let path: Vec<_> = trait_ref.path.segments.iter()
2172 .map(|seg| respan(seg.span, seg.identifier))
2174 let def = self.smart_resolve_path_fragment(trait_ref.ref_id,
2177 trait_ref.path.span,
2178 trait_ref.path.segments.last().unwrap().span,
2179 PathSource::Trait(AliasPossibility::No))
2181 if def != Def::Err {
2182 new_id = Some(def.def_id());
2183 let span = trait_ref.path.span;
2184 if let PathResult::Module(module) = self.resolve_path(&path, None, false, span) {
2185 new_val = Some((module, trait_ref.clone()));
2189 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2190 let result = f(self, new_id);
2191 self.current_trait_ref = original_trait_ref;
2195 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2196 where F: FnOnce(&mut Resolver)
2198 let mut self_type_rib = Rib::new(NormalRibKind);
2200 // plain insert (no renaming, types are not currently hygienic....)
2201 self_type_rib.bindings.insert(keywords::SelfType.ident(), self_def);
2202 self.ribs[TypeNS].push(self_type_rib);
2204 self.ribs[TypeNS].pop();
2207 fn resolve_implementation(&mut self,
2208 generics: &Generics,
2209 opt_trait_reference: &Option<TraitRef>,
2212 impl_items: &[ImplItem]) {
2213 // If applicable, create a rib for the type parameters.
2214 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2215 // Dummy self type for better errors if `Self` is used in the trait path.
2216 this.with_self_rib(Def::SelfTy(None, None), |this| {
2217 // Resolve the trait reference, if necessary.
2218 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2219 let item_def_id = this.definitions.local_def_id(item_id);
2220 this.with_self_rib(Def::SelfTy(trait_id, Some(item_def_id)), |this| {
2221 if let Some(trait_ref) = opt_trait_reference.as_ref() {
2222 // Resolve type arguments in trait path
2223 visit::walk_trait_ref(this, trait_ref);
2225 // Resolve the self type.
2226 this.visit_ty(self_type);
2227 // Resolve the type parameters.
2228 this.visit_generics(generics);
2229 this.with_current_self_type(self_type, |this| {
2230 for impl_item in impl_items {
2231 this.check_proc_macro_attrs(&impl_item.attrs);
2232 this.resolve_visibility(&impl_item.vis);
2234 // We also need a new scope for the impl item type parameters.
2235 let type_parameters = HasTypeParameters(&impl_item.generics,
2236 TraitOrImplItemRibKind);
2237 this.with_type_parameter_rib(type_parameters, |this| {
2238 use self::ResolutionError::*;
2239 match impl_item.node {
2240 ImplItemKind::Const(..) => {
2241 // If this is a trait impl, ensure the const
2243 this.check_trait_item(impl_item.ident,
2246 |n, s| ConstNotMemberOfTrait(n, s));
2247 this.with_constant_rib(|this|
2248 visit::walk_impl_item(this, impl_item)
2251 ImplItemKind::Method(_, _) => {
2252 // If this is a trait impl, ensure the method
2254 this.check_trait_item(impl_item.ident,
2257 |n, s| MethodNotMemberOfTrait(n, s));
2259 visit::walk_impl_item(this, impl_item);
2261 ImplItemKind::Type(ref ty) => {
2262 // If this is a trait impl, ensure the type
2264 this.check_trait_item(impl_item.ident,
2267 |n, s| TypeNotMemberOfTrait(n, s));
2271 ImplItemKind::Macro(_) =>
2272 panic!("unexpanded macro in resolve!"),
2283 fn check_trait_item<F>(&mut self, ident: Ident, ns: Namespace, span: Span, err: F)
2284 where F: FnOnce(Name, &str) -> ResolutionError
2286 // If there is a TraitRef in scope for an impl, then the method must be in the
2288 if let Some((module, _)) = self.current_trait_ref {
2289 if self.resolve_ident_in_module(module, ident, ns, false, false, span).is_err() {
2290 let path = &self.current_trait_ref.as_ref().unwrap().1.path;
2291 resolve_error(self, span, err(ident.name, &path_names_to_string(path)));
2296 fn resolve_local(&mut self, local: &Local) {
2297 // Resolve the type.
2298 walk_list!(self, visit_ty, &local.ty);
2300 // Resolve the initializer.
2301 walk_list!(self, visit_expr, &local.init);
2303 // Resolve the pattern.
2304 self.resolve_pattern(&local.pat, PatternSource::Let, &mut FxHashMap());
2307 // build a map from pattern identifiers to binding-info's.
2308 // this is done hygienically. This could arise for a macro
2309 // that expands into an or-pattern where one 'x' was from the
2310 // user and one 'x' came from the macro.
2311 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2312 let mut binding_map = FxHashMap();
2314 pat.walk(&mut |pat| {
2315 if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node {
2316 if sub_pat.is_some() || match self.def_map.get(&pat.id).map(|res| res.base_def()) {
2317 Some(Def::Local(..)) => true,
2320 let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode };
2321 binding_map.insert(ident.node, binding_info);
2330 // check that all of the arms in an or-pattern have exactly the
2331 // same set of bindings, with the same binding modes for each.
2332 fn check_consistent_bindings(&mut self, arm: &Arm) {
2333 if arm.pats.is_empty() {
2337 let mut missing_vars = FxHashMap();
2338 let mut inconsistent_vars = FxHashMap();
2339 for (i, p) in arm.pats.iter().enumerate() {
2340 let map_i = self.binding_mode_map(&p);
2342 for (j, q) in arm.pats.iter().enumerate() {
2347 let map_j = self.binding_mode_map(&q);
2348 for (&key, &binding_i) in &map_i {
2349 if map_j.len() == 0 { // Account for missing bindings when
2350 let binding_error = missing_vars // map_j has none.
2352 .or_insert(BindingError {
2354 origin: BTreeSet::new(),
2355 target: BTreeSet::new(),
2357 binding_error.origin.insert(binding_i.span);
2358 binding_error.target.insert(q.span);
2360 for (&key_j, &binding_j) in &map_j {
2361 match map_i.get(&key_j) {
2362 None => { // missing binding
2363 let binding_error = missing_vars
2365 .or_insert(BindingError {
2367 origin: BTreeSet::new(),
2368 target: BTreeSet::new(),
2370 binding_error.origin.insert(binding_j.span);
2371 binding_error.target.insert(p.span);
2373 Some(binding_i) => { // check consistent binding
2374 if binding_i.binding_mode != binding_j.binding_mode {
2377 .or_insert((binding_j.span, binding_i.span));
2385 let mut missing_vars = missing_vars.iter().collect::<Vec<_>>();
2386 missing_vars.sort();
2387 for (_, v) in missing_vars {
2389 *v.origin.iter().next().unwrap(),
2390 ResolutionError::VariableNotBoundInPattern(v));
2392 let mut inconsistent_vars = inconsistent_vars.iter().collect::<Vec<_>>();
2393 inconsistent_vars.sort();
2394 for (name, v) in inconsistent_vars {
2395 resolve_error(self, v.0, ResolutionError::VariableBoundWithDifferentMode(*name, v.1));
2399 fn resolve_arm(&mut self, arm: &Arm) {
2400 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2402 let mut bindings_list = FxHashMap();
2403 for pattern in &arm.pats {
2404 self.resolve_pattern(&pattern, PatternSource::Match, &mut bindings_list);
2407 // This has to happen *after* we determine which
2408 // pat_idents are variants
2409 self.check_consistent_bindings(arm);
2411 walk_list!(self, visit_expr, &arm.guard);
2412 self.visit_expr(&arm.body);
2414 self.ribs[ValueNS].pop();
2417 fn resolve_block(&mut self, block: &Block) {
2418 debug!("(resolving block) entering block");
2419 // Move down in the graph, if there's an anonymous module rooted here.
2420 let orig_module = self.current_module;
2421 let anonymous_module = self.block_map.get(&block.id).cloned(); // clones a reference
2423 let mut num_macro_definition_ribs = 0;
2424 if let Some(anonymous_module) = anonymous_module {
2425 debug!("(resolving block) found anonymous module, moving down");
2426 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2427 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2428 self.current_module = anonymous_module;
2429 self.finalize_current_module_macro_resolutions();
2431 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2434 // Descend into the block.
2435 for stmt in &block.stmts {
2436 if let ast::StmtKind::Item(ref item) = stmt.node {
2437 if let ast::ItemKind::MacroDef(..) = item.node {
2438 num_macro_definition_ribs += 1;
2439 let def = self.definitions.local_def_id(item.id);
2440 self.ribs[ValueNS].push(Rib::new(MacroDefinition(def)));
2441 self.label_ribs.push(Rib::new(MacroDefinition(def)));
2445 self.visit_stmt(stmt);
2449 self.current_module = orig_module;
2450 for _ in 0 .. num_macro_definition_ribs {
2451 self.ribs[ValueNS].pop();
2452 self.label_ribs.pop();
2454 self.ribs[ValueNS].pop();
2455 if let Some(_) = anonymous_module {
2456 self.ribs[TypeNS].pop();
2458 debug!("(resolving block) leaving block");
2461 fn fresh_binding(&mut self,
2462 ident: &SpannedIdent,
2464 outer_pat_id: NodeId,
2465 pat_src: PatternSource,
2466 bindings: &mut FxHashMap<Ident, NodeId>)
2468 // Add the binding to the local ribs, if it
2469 // doesn't already exist in the bindings map. (We
2470 // must not add it if it's in the bindings map
2471 // because that breaks the assumptions later
2472 // passes make about or-patterns.)
2473 let mut def = Def::Local(pat_id);
2474 match bindings.get(&ident.node).cloned() {
2475 Some(id) if id == outer_pat_id => {
2476 // `Variant(a, a)`, error
2480 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2481 &ident.node.name.as_str())
2484 Some(..) if pat_src == PatternSource::FnParam => {
2485 // `fn f(a: u8, a: u8)`, error
2489 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2490 &ident.node.name.as_str())
2493 Some(..) if pat_src == PatternSource::Match => {
2494 // `Variant1(a) | Variant2(a)`, ok
2495 // Reuse definition from the first `a`.
2496 def = self.ribs[ValueNS].last_mut().unwrap().bindings[&ident.node];
2499 span_bug!(ident.span, "two bindings with the same name from \
2500 unexpected pattern source {:?}", pat_src);
2503 // A completely fresh binding, add to the lists if it's valid.
2504 if ident.node.name != keywords::Invalid.name() {
2505 bindings.insert(ident.node, outer_pat_id);
2506 self.ribs[ValueNS].last_mut().unwrap().bindings.insert(ident.node, def);
2511 PathResolution::new(def)
2514 fn resolve_pattern(&mut self,
2516 pat_src: PatternSource,
2517 // Maps idents to the node ID for the
2518 // outermost pattern that binds them.
2519 bindings: &mut FxHashMap<Ident, NodeId>) {
2520 // Visit all direct subpatterns of this pattern.
2521 let outer_pat_id = pat.id;
2522 pat.walk(&mut |pat| {
2524 PatKind::Ident(bmode, ref ident, ref opt_pat) => {
2525 // First try to resolve the identifier as some existing
2526 // entity, then fall back to a fresh binding.
2527 let binding = self.resolve_ident_in_lexical_scope(ident.node, ValueNS,
2529 .and_then(LexicalScopeBinding::item);
2530 let resolution = binding.map(NameBinding::def).and_then(|def| {
2531 let is_syntactic_ambiguity = opt_pat.is_none() &&
2532 bmode == BindingMode::ByValue(Mutability::Immutable);
2534 Def::StructCtor(_, CtorKind::Const) |
2535 Def::VariantCtor(_, CtorKind::Const) |
2536 Def::Const(..) if is_syntactic_ambiguity => {
2537 // Disambiguate in favor of a unit struct/variant
2538 // or constant pattern.
2539 self.record_use(ident.node, ValueNS, binding.unwrap(), ident.span);
2540 Some(PathResolution::new(def))
2542 Def::StructCtor(..) | Def::VariantCtor(..) |
2543 Def::Const(..) | Def::Static(..) => {
2544 // This is unambiguously a fresh binding, either syntactically
2545 // (e.g. `IDENT @ PAT` or `ref IDENT`) or because `IDENT` resolves
2546 // to something unusable as a pattern (e.g. constructor function),
2547 // but we still conservatively report an error, see
2548 // issues/33118#issuecomment-233962221 for one reason why.
2552 ResolutionError::BindingShadowsSomethingUnacceptable(
2553 pat_src.descr(), ident.node.name, binding.unwrap())
2557 Def::Fn(..) | Def::Err => {
2558 // These entities are explicitly allowed
2559 // to be shadowed by fresh bindings.
2563 span_bug!(ident.span, "unexpected definition for an \
2564 identifier in pattern: {:?}", def);
2567 }).unwrap_or_else(|| {
2568 self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings)
2571 self.record_def(pat.id, resolution);
2574 PatKind::TupleStruct(ref path, ..) => {
2575 self.smart_resolve_path(pat.id, None, path, PathSource::TupleStruct);
2578 PatKind::Path(ref qself, ref path) => {
2579 self.smart_resolve_path(pat.id, qself.as_ref(), path, PathSource::Pat);
2582 PatKind::Struct(ref path, ..) => {
2583 self.smart_resolve_path(pat.id, None, path, PathSource::Struct);
2591 visit::walk_pat(self, pat);
2594 // High-level and context dependent path resolution routine.
2595 // Resolves the path and records the resolution into definition map.
2596 // If resolution fails tries several techniques to find likely
2597 // resolution candidates, suggest imports or other help, and report
2598 // errors in user friendly way.
2599 fn smart_resolve_path(&mut self,
2601 qself: Option<&QSelf>,
2605 let segments = &path.segments.iter()
2606 .map(|seg| respan(seg.span, seg.identifier))
2607 .collect::<Vec<_>>();
2608 let ident_span = path.segments.last().map_or(path.span, |seg| seg.span);
2609 self.smart_resolve_path_fragment(id, qself, segments, path.span, ident_span, source)
2612 fn smart_resolve_path_fragment(&mut self,
2614 qself: Option<&QSelf>,
2615 path: &[SpannedIdent],
2620 let ns = source.namespace();
2621 let is_expected = &|def| source.is_expected(def);
2622 let is_enum_variant = &|def| if let Def::Variant(..) = def { true } else { false };
2624 // Base error is amended with one short label and possibly some longer helps/notes.
2625 let report_errors = |this: &mut Self, def: Option<Def>| {
2626 // Make the base error.
2627 let expected = source.descr_expected();
2628 let path_str = names_to_string(path);
2629 let code = source.error_code(def.is_some());
2630 let (base_msg, fallback_label, base_span) = if let Some(def) = def {
2631 (format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str),
2632 format!("not a {}", expected),
2635 let item_str = path[path.len() - 1].node;
2636 let item_span = path[path.len() - 1].span;
2637 let (mod_prefix, mod_str) = if path.len() == 1 {
2638 (format!(""), format!("this scope"))
2639 } else if path.len() == 2 && path[0].node.name == keywords::CrateRoot.name() {
2640 (format!(""), format!("the crate root"))
2642 let mod_path = &path[..path.len() - 1];
2643 let mod_prefix = match this.resolve_path(mod_path, Some(TypeNS), false, span) {
2644 PathResult::Module(module) => module.def(),
2646 }.map_or(format!(""), |def| format!("{} ", def.kind_name()));
2647 (mod_prefix, format!("`{}`", names_to_string(mod_path)))
2649 (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str),
2650 format!("not found in {}", mod_str),
2653 let code = DiagnosticId::Error(code.into());
2654 let mut err = this.session.struct_span_err_with_code(base_span, &base_msg, code);
2656 // Emit special messages for unresolved `Self` and `self`.
2657 if is_self_type(path, ns) {
2658 __diagnostic_used!(E0411);
2659 err.code(DiagnosticId::Error("E0411".into()));
2660 err.span_label(span, "`Self` is only available in traits and impls");
2661 return (err, Vec::new());
2663 if is_self_value(path, ns) {
2664 __diagnostic_used!(E0424);
2665 err.code(DiagnosticId::Error("E0424".into()));
2666 err.span_label(span, format!("`self` value is only available in \
2667 methods with `self` parameter"));
2668 return (err, Vec::new());
2671 // Try to lookup the name in more relaxed fashion for better error reporting.
2672 let ident = *path.last().unwrap();
2673 let candidates = this.lookup_import_candidates(ident.node.name, ns, is_expected);
2674 if candidates.is_empty() && is_expected(Def::Enum(DefId::local(CRATE_DEF_INDEX))) {
2675 let enum_candidates =
2676 this.lookup_import_candidates(ident.node.name, ns, is_enum_variant);
2677 let mut enum_candidates = enum_candidates.iter()
2678 .map(|suggestion| import_candidate_to_paths(&suggestion)).collect::<Vec<_>>();
2679 enum_candidates.sort();
2680 for (sp, variant_path, enum_path) in enum_candidates {
2682 let msg = format!("there is an enum variant `{}`, \
2688 err.span_suggestion(span, "you can try using the variant's enum",
2693 if path.len() == 1 && this.self_type_is_available(span) {
2694 if let Some(candidate) = this.lookup_assoc_candidate(ident.node, ns, is_expected) {
2695 let self_is_available = this.self_value_is_available(path[0].node.ctxt, span);
2697 AssocSuggestion::Field => {
2698 err.span_suggestion(span, "try",
2699 format!("self.{}", path_str));
2700 if !self_is_available {
2701 err.span_label(span, format!("`self` value is only available in \
2702 methods with `self` parameter"));
2705 AssocSuggestion::MethodWithSelf if self_is_available => {
2706 err.span_suggestion(span, "try",
2707 format!("self.{}", path_str));
2709 AssocSuggestion::MethodWithSelf | AssocSuggestion::AssocItem => {
2710 err.span_suggestion(span, "try",
2711 format!("Self::{}", path_str));
2714 return (err, candidates);
2718 let mut levenshtein_worked = false;
2721 if let Some(candidate) = this.lookup_typo_candidate(path, ns, is_expected, span) {
2722 err.span_label(ident_span, format!("did you mean `{}`?", candidate));
2723 levenshtein_worked = true;
2726 // Try context dependent help if relaxed lookup didn't work.
2727 if let Some(def) = def {
2728 match (def, source) {
2729 (Def::Macro(..), _) => {
2730 err.span_label(span, format!("did you mean `{}!(...)`?", path_str));
2731 return (err, candidates);
2733 (Def::TyAlias(..), PathSource::Trait(_)) => {
2734 err.span_label(span, "type aliases cannot be used for traits");
2735 return (err, candidates);
2737 (Def::Mod(..), PathSource::Expr(Some(parent))) => match parent.node {
2738 ExprKind::Field(_, ident) => {
2739 err.span_label(parent.span, format!("did you mean `{}::{}`?",
2740 path_str, ident.node));
2741 return (err, candidates);
2743 ExprKind::MethodCall(ref segment, ..) => {
2744 err.span_label(parent.span, format!("did you mean `{}::{}(...)`?",
2745 path_str, segment.identifier));
2746 return (err, candidates);
2750 (Def::Enum(..), PathSource::TupleStruct)
2751 | (Def::Enum(..), PathSource::Expr(..)) => {
2752 if let Some(variants) = this.collect_enum_variants(def) {
2753 err.note(&format!("did you mean to use one \
2754 of the following variants?\n{}",
2756 .map(|suggestion| path_names_to_string(suggestion))
2757 .map(|suggestion| format!("- `{}`", suggestion))
2758 .collect::<Vec<_>>()
2762 err.note("did you mean to use one of the enum's variants?");
2764 return (err, candidates);
2766 (Def::Struct(def_id), _) if ns == ValueNS => {
2767 if let Some((ctor_def, ctor_vis))
2768 = this.struct_constructors.get(&def_id).cloned() {
2769 let accessible_ctor = this.is_accessible(ctor_vis);
2770 if is_expected(ctor_def) && !accessible_ctor {
2771 err.span_label(span, format!("constructor is not visible \
2772 here due to private fields"));
2775 err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?",
2778 return (err, candidates);
2780 (Def::Union(..), _) |
2781 (Def::Variant(..), _) |
2782 (Def::VariantCtor(_, CtorKind::Fictive), _) if ns == ValueNS => {
2783 err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?",
2785 return (err, candidates);
2787 (Def::SelfTy(..), _) if ns == ValueNS => {
2788 err.span_label(span, fallback_label);
2789 err.note("can't use `Self` as a constructor, you must use the \
2790 implemented struct");
2791 return (err, candidates);
2793 (Def::TyAlias(_), _) | (Def::AssociatedTy(..), _) if ns == ValueNS => {
2794 err.note("can't use a type alias as a constructor");
2795 return (err, candidates);
2802 if !levenshtein_worked {
2803 err.span_label(base_span, fallback_label);
2804 this.type_ascription_suggestion(&mut err, base_span);
2808 let report_errors = |this: &mut Self, def: Option<Def>| {
2809 let (err, candidates) = report_errors(this, def);
2810 let def_id = this.current_module.normal_ancestor_id;
2811 let node_id = this.definitions.as_local_node_id(def_id).unwrap();
2812 let better = def.is_some();
2813 this.use_injections.push(UseError { err, candidates, node_id, better });
2814 err_path_resolution()
2817 let resolution = match self.resolve_qpath_anywhere(id, qself, path, ns, span,
2818 source.defer_to_typeck(),
2819 source.global_by_default()) {
2820 Some(resolution) if resolution.unresolved_segments() == 0 => {
2821 if is_expected(resolution.base_def()) || resolution.base_def() == Def::Err {
2824 // Add a temporary hack to smooth the transition to new struct ctor
2825 // visibility rules. See #38932 for more details.
2827 if let Def::Struct(def_id) = resolution.base_def() {
2828 if let Some((ctor_def, ctor_vis))
2829 = self.struct_constructors.get(&def_id).cloned() {
2830 if is_expected(ctor_def) && self.is_accessible(ctor_vis) {
2831 let lint = lint::builtin::LEGACY_CONSTRUCTOR_VISIBILITY;
2832 self.session.buffer_lint(lint, id, span,
2833 "private struct constructors are not usable through \
2834 re-exports in outer modules",
2836 res = Some(PathResolution::new(ctor_def));
2841 res.unwrap_or_else(|| report_errors(self, Some(resolution.base_def())))
2844 Some(resolution) if source.defer_to_typeck() => {
2845 // Not fully resolved associated item `T::A::B` or `<T as Tr>::A::B`
2846 // or `<T>::A::B`. If `B` should be resolved in value namespace then
2847 // it needs to be added to the trait map.
2849 let item_name = path.last().unwrap().node;
2850 let traits = self.get_traits_containing_item(item_name, ns);
2851 self.trait_map.insert(id, traits);
2855 _ => report_errors(self, None)
2858 if let PathSource::TraitItem(..) = source {} else {
2859 // Avoid recording definition of `A::B` in `<T as A>::B::C`.
2860 self.record_def(id, resolution);
2865 fn type_ascription_suggestion(&self,
2866 err: &mut DiagnosticBuilder,
2868 debug!("type_ascription_suggetion {:?}", base_span);
2869 let cm = self.session.codemap();
2870 debug!("self.current_type_ascription {:?}", self.current_type_ascription);
2871 if let Some(sp) = self.current_type_ascription.last() {
2873 loop { // try to find the `:`, bail on first non-':'/non-whitespace
2874 sp = cm.next_point(sp);
2875 if let Ok(snippet) = cm.span_to_snippet(sp.to(cm.next_point(sp))) {
2876 debug!("snippet {:?}", snippet);
2877 let line_sp = cm.lookup_char_pos(sp.hi()).line;
2878 let line_base_sp = cm.lookup_char_pos(base_span.lo()).line;
2879 debug!("{:?} {:?}", line_sp, line_base_sp);
2881 err.span_label(base_span,
2882 "expecting a type here because of type ascription");
2883 if line_sp != line_base_sp {
2884 err.span_suggestion_short(sp,
2885 "did you mean to use `;` here instead?",
2889 } else if snippet.trim().len() != 0 {
2890 debug!("tried to find type ascription `:` token, couldn't find it");
2900 fn self_type_is_available(&mut self, span: Span) -> bool {
2901 let binding = self.resolve_ident_in_lexical_scope(keywords::SelfType.ident(),
2902 TypeNS, false, span);
2903 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
2906 fn self_value_is_available(&mut self, ctxt: SyntaxContext, span: Span) -> bool {
2907 let ident = Ident { name: keywords::SelfValue.name(), ctxt: ctxt };
2908 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, false, span);
2909 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
2912 // Resolve in alternative namespaces if resolution in the primary namespace fails.
2913 fn resolve_qpath_anywhere(&mut self,
2915 qself: Option<&QSelf>,
2916 path: &[SpannedIdent],
2917 primary_ns: Namespace,
2919 defer_to_typeck: bool,
2920 global_by_default: bool)
2921 -> Option<PathResolution> {
2922 let mut fin_res = None;
2923 // FIXME: can't resolve paths in macro namespace yet, macros are
2924 // processed by the little special hack below.
2925 for (i, ns) in [primary_ns, TypeNS, ValueNS, /*MacroNS*/].iter().cloned().enumerate() {
2926 if i == 0 || ns != primary_ns {
2927 match self.resolve_qpath(id, qself, path, ns, span, global_by_default) {
2928 // If defer_to_typeck, then resolution > no resolution,
2929 // otherwise full resolution > partial resolution > no resolution.
2930 Some(res) if res.unresolved_segments() == 0 || defer_to_typeck =>
2932 res => if fin_res.is_none() { fin_res = res },
2936 let is_global = self.global_macros.get(&path[0].node.name).cloned()
2937 .map(|binding| binding.get_macro(self).kind() == MacroKind::Bang).unwrap_or(false);
2938 if primary_ns != MacroNS && (is_global ||
2939 self.macro_names.contains(&path[0].node.modern())) {
2940 // Return some dummy definition, it's enough for error reporting.
2942 PathResolution::new(Def::Macro(DefId::local(CRATE_DEF_INDEX), MacroKind::Bang))
2948 /// Handles paths that may refer to associated items.
2949 fn resolve_qpath(&mut self,
2951 qself: Option<&QSelf>,
2952 path: &[SpannedIdent],
2955 global_by_default: bool)
2956 -> Option<PathResolution> {
2957 if let Some(qself) = qself {
2958 if qself.position == 0 {
2959 // FIXME: Create some fake resolution that can't possibly be a type.
2960 return Some(PathResolution::with_unresolved_segments(
2961 Def::Mod(DefId::local(CRATE_DEF_INDEX)), path.len()
2964 // Make sure `A::B` in `<T as A>::B::C` is a trait item.
2965 let ns = if qself.position + 1 == path.len() { ns } else { TypeNS };
2966 let res = self.smart_resolve_path_fragment(id, None, &path[..qself.position + 1],
2967 span, span, PathSource::TraitItem(ns));
2968 return Some(PathResolution::with_unresolved_segments(
2969 res.base_def(), res.unresolved_segments() + path.len() - qself.position - 1
2973 let result = match self.resolve_path(&path, Some(ns), true, span) {
2974 PathResult::NonModule(path_res) => path_res,
2975 PathResult::Module(module) if !module.is_normal() => {
2976 PathResolution::new(module.def().unwrap())
2978 // In `a(::assoc_item)*` `a` cannot be a module. If `a` does resolve to a module we
2979 // don't report an error right away, but try to fallback to a primitive type.
2980 // So, we are still able to successfully resolve something like
2982 // use std::u8; // bring module u8 in scope
2983 // fn f() -> u8 { // OK, resolves to primitive u8, not to std::u8
2984 // u8::max_value() // OK, resolves to associated function <u8>::max_value,
2985 // // not to non-existent std::u8::max_value
2988 // Such behavior is required for backward compatibility.
2989 // The same fallback is used when `a` resolves to nothing.
2990 PathResult::Module(..) | PathResult::Failed(..)
2991 if (ns == TypeNS || path.len() > 1) &&
2992 self.primitive_type_table.primitive_types
2993 .contains_key(&path[0].node.name) => {
2994 let prim = self.primitive_type_table.primitive_types[&path[0].node.name];
2996 TyUint(UintTy::U128) | TyInt(IntTy::I128) => {
2997 if !self.session.features.borrow().i128_type {
2998 emit_feature_err(&self.session.parse_sess,
2999 "i128_type", span, GateIssue::Language,
3000 "128-bit type is unstable");
3006 PathResolution::with_unresolved_segments(Def::PrimTy(prim), path.len() - 1)
3008 PathResult::Module(module) => PathResolution::new(module.def().unwrap()),
3009 PathResult::Failed(span, msg, false) => {
3010 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
3011 err_path_resolution()
3013 PathResult::Failed(..) => return None,
3014 PathResult::Indeterminate => bug!("indetermined path result in resolve_qpath"),
3017 if path.len() > 1 && !global_by_default && result.base_def() != Def::Err &&
3018 path[0].node.name != keywords::CrateRoot.name() &&
3019 path[0].node.name != keywords::DollarCrate.name() {
3020 let unqualified_result = {
3021 match self.resolve_path(&[*path.last().unwrap()], Some(ns), false, span) {
3022 PathResult::NonModule(path_res) => path_res.base_def(),
3023 PathResult::Module(module) => module.def().unwrap(),
3024 _ => return Some(result),
3027 if result.base_def() == unqualified_result {
3028 let lint = lint::builtin::UNUSED_QUALIFICATIONS;
3029 self.session.buffer_lint(lint, id, span, "unnecessary qualification")
3036 fn resolve_path(&mut self,
3037 path: &[SpannedIdent],
3038 opt_ns: Option<Namespace>, // `None` indicates a module path
3042 let mut module = None;
3043 let mut allow_super = true;
3045 for (i, &ident) in path.iter().enumerate() {
3046 debug!("resolve_path ident {} {:?}", i, ident);
3047 let is_last = i == path.len() - 1;
3048 let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
3049 let name = ident.node.name;
3051 if i == 0 && ns == TypeNS && name == keywords::SelfValue.name() {
3052 let mut ctxt = ident.node.ctxt.modern();
3053 module = Some(self.resolve_self(&mut ctxt, self.current_module));
3055 } else if allow_super && ns == TypeNS && name == keywords::Super.name() {
3056 let mut ctxt = ident.node.ctxt.modern();
3057 let self_module = match i {
3058 0 => self.resolve_self(&mut ctxt, self.current_module),
3059 _ => module.unwrap(),
3061 if let Some(parent) = self_module.parent {
3062 module = Some(self.resolve_self(&mut ctxt, parent));
3065 let msg = "There are too many initial `super`s.".to_string();
3066 return PathResult::Failed(ident.span, msg, false);
3068 } else if i == 0 && ns == TypeNS && name == keywords::Extern.name() {
3071 allow_super = false;
3074 if (i == 0 && name == keywords::CrateRoot.name()) ||
3075 (i == 1 && name == keywords::Crate.name() &&
3076 path[0].node.name == keywords::CrateRoot.name()) {
3077 // `::a::b` or `::crate::a::b`
3078 module = Some(self.resolve_crate_root(ident.node.ctxt, false));
3080 } else if i == 0 && name == keywords::DollarCrate.name() {
3082 module = Some(self.resolve_crate_root(ident.node.ctxt, true));
3084 } else if i == 1 && !token::Ident(ident.node).is_path_segment_keyword() {
3085 let prev_name = path[0].node.name;
3086 if prev_name == keywords::Extern.name() ||
3087 prev_name == keywords::CrateRoot.name() &&
3088 self.session.features.borrow().extern_absolute_paths {
3089 // `::extern_crate::a::b`
3090 let crate_id = self.crate_loader.resolve_crate_from_path(name, ident.span);
3092 self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
3093 self.populate_module_if_necessary(crate_root);
3094 module = Some(crate_root);
3100 // Report special messages for path segment keywords in wrong positions.
3101 if name == keywords::CrateRoot.name() && i != 0 ||
3102 name == keywords::DollarCrate.name() && i != 0 ||
3103 name == keywords::SelfValue.name() && i != 0 ||
3104 name == keywords::SelfType.name() && i != 0 ||
3105 name == keywords::Super.name() && i != 0 ||
3106 name == keywords::Extern.name() && i != 0 ||
3107 name == keywords::Crate.name() && i != 1 &&
3108 path[0].node.name != keywords::CrateRoot.name() {
3109 let name_str = if name == keywords::CrateRoot.name() {
3110 format!("crate root")
3112 format!("`{}`", name)
3114 let msg = if i == 1 && path[0].node.name == keywords::CrateRoot.name() {
3115 format!("global paths cannot start with {}", name_str)
3116 } else if i == 0 && name == keywords::Crate.name() {
3117 format!("{} can only be used in absolute paths", name_str)
3119 format!("{} in paths can only be used in start position", name_str)
3121 return PathResult::Failed(ident.span, msg, false);
3124 let binding = if let Some(module) = module {
3125 self.resolve_ident_in_module(module, ident.node, ns, false, record_used, path_span)
3126 } else if opt_ns == Some(MacroNS) {
3127 self.resolve_lexical_macro_path_segment(ident.node, ns, record_used, path_span)
3128 .map(MacroBinding::binding)
3130 match self.resolve_ident_in_lexical_scope(ident.node, ns, record_used, path_span) {
3131 Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
3132 Some(LexicalScopeBinding::Def(def))
3133 if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) => {
3134 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3138 _ => Err(if record_used { Determined } else { Undetermined }),
3144 let def = binding.def();
3145 let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(def);
3146 if let Some(next_module) = binding.module() {
3147 module = Some(next_module);
3148 } else if def == Def::Err {
3149 return PathResult::NonModule(err_path_resolution());
3150 } else if opt_ns.is_some() && (is_last || maybe_assoc) {
3151 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3152 def, path.len() - i - 1
3155 return PathResult::Failed(ident.span,
3156 format!("Not a module `{}`", ident.node),
3160 Err(Undetermined) => return PathResult::Indeterminate,
3161 Err(Determined) => {
3162 if let Some(module) = module {
3163 if opt_ns.is_some() && !module.is_normal() {
3164 return PathResult::NonModule(PathResolution::with_unresolved_segments(
3165 module.def().unwrap(), path.len() - i
3169 let msg = if module.and_then(ModuleData::def) == self.graph_root.def() {
3170 let is_mod = |def| match def { Def::Mod(..) => true, _ => false };
3171 let mut candidates =
3172 self.lookup_import_candidates(name, TypeNS, is_mod);
3173 candidates.sort_by_key(|c| (c.path.segments.len(), c.path.to_string()));
3174 if let Some(candidate) = candidates.get(0) {
3175 format!("Did you mean `{}`?", candidate.path)
3177 format!("Maybe a missing `extern crate {};`?", ident.node)
3180 format!("Use of undeclared type or module `{}`", ident.node)
3182 format!("Could not find `{}` in `{}`", ident.node, path[i - 1].node)
3184 return PathResult::Failed(ident.span, msg, is_last);
3189 PathResult::Module(module.unwrap_or(self.graph_root))
3192 // Resolve a local definition, potentially adjusting for closures.
3193 fn adjust_local_def(&mut self,
3198 span: Span) -> Def {
3199 let ribs = &self.ribs[ns][rib_index + 1..];
3201 // An invalid forward use of a type parameter from a previous default.
3202 if let ForwardTyParamBanRibKind = self.ribs[ns][rib_index].kind {
3204 resolve_error(self, span, ResolutionError::ForwardDeclaredTyParam);
3206 assert_eq!(def, Def::Err);
3212 span_bug!(span, "unexpected {:?} in bindings", def)
3214 Def::Local(node_id) => {
3217 NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) |
3218 ForwardTyParamBanRibKind => {
3219 // Nothing to do. Continue.
3221 ClosureRibKind(function_id) => {
3224 let seen = self.freevars_seen
3226 .or_insert_with(|| NodeMap());
3227 if let Some(&index) = seen.get(&node_id) {
3228 def = Def::Upvar(node_id, index, function_id);
3231 let vec = self.freevars
3233 .or_insert_with(|| vec![]);
3234 let depth = vec.len();
3235 def = Def::Upvar(node_id, depth, function_id);
3242 seen.insert(node_id, depth);
3245 ItemRibKind | TraitOrImplItemRibKind => {
3246 // This was an attempt to access an upvar inside a
3247 // named function item. This is not allowed, so we
3250 resolve_error(self, span,
3251 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
3255 ConstantItemRibKind => {
3256 // Still doesn't deal with upvars
3258 resolve_error(self, span,
3259 ResolutionError::AttemptToUseNonConstantValueInConstant);
3266 Def::TyParam(..) | Def::SelfTy(..) => {
3269 NormalRibKind | TraitOrImplItemRibKind | ClosureRibKind(..) |
3270 ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind |
3271 ConstantItemRibKind => {
3272 // Nothing to do. Continue.
3275 // This was an attempt to use a type parameter outside
3278 resolve_error(self, span,
3279 ResolutionError::TypeParametersFromOuterFunction);
3291 fn lookup_assoc_candidate<FilterFn>(&mut self,
3294 filter_fn: FilterFn)
3295 -> Option<AssocSuggestion>
3296 where FilterFn: Fn(Def) -> bool
3298 fn extract_node_id(t: &Ty) -> Option<NodeId> {
3300 TyKind::Path(None, _) => Some(t.id),
3301 TyKind::Rptr(_, ref mut_ty) => extract_node_id(&mut_ty.ty),
3302 // This doesn't handle the remaining `Ty` variants as they are not
3303 // that commonly the self_type, it might be interesting to provide
3304 // support for those in future.
3309 // Fields are generally expected in the same contexts as locals.
3310 if filter_fn(Def::Local(ast::DUMMY_NODE_ID)) {
3311 if let Some(node_id) = self.current_self_type.as_ref().and_then(extract_node_id) {
3312 // Look for a field with the same name in the current self_type.
3313 if let Some(resolution) = self.def_map.get(&node_id) {
3314 match resolution.base_def() {
3315 Def::Struct(did) | Def::Union(did)
3316 if resolution.unresolved_segments() == 0 => {
3317 if let Some(field_names) = self.field_names.get(&did) {
3318 if field_names.iter().any(|&field_name| ident.name == field_name) {
3319 return Some(AssocSuggestion::Field);
3329 // Look for associated items in the current trait.
3330 if let Some((module, _)) = self.current_trait_ref {
3331 if let Ok(binding) =
3332 self.resolve_ident_in_module(module, ident, ns, false, false, module.span) {
3333 let def = binding.def();
3335 return Some(if self.has_self.contains(&def.def_id()) {
3336 AssocSuggestion::MethodWithSelf
3338 AssocSuggestion::AssocItem
3347 fn lookup_typo_candidate<FilterFn>(&mut self,
3348 path: &[SpannedIdent],
3350 filter_fn: FilterFn,
3353 where FilterFn: Fn(Def) -> bool
3355 let add_module_candidates = |module: Module, names: &mut Vec<Name>| {
3356 for (&(ident, _), resolution) in module.resolutions.borrow().iter() {
3357 if let Some(binding) = resolution.borrow().binding {
3358 if filter_fn(binding.def()) {
3359 names.push(ident.name);
3365 let mut names = Vec::new();
3366 if path.len() == 1 {
3367 // Search in lexical scope.
3368 // Walk backwards up the ribs in scope and collect candidates.
3369 for rib in self.ribs[ns].iter().rev() {
3370 // Locals and type parameters
3371 for (ident, def) in &rib.bindings {
3372 if filter_fn(*def) {
3373 names.push(ident.name);
3377 if let ModuleRibKind(module) = rib.kind {
3378 // Items from this module
3379 add_module_candidates(module, &mut names);
3381 if let ModuleKind::Block(..) = module.kind {
3382 // We can see through blocks
3384 // Items from the prelude
3385 if let Some(prelude) = self.prelude {
3386 if !module.no_implicit_prelude {
3387 add_module_candidates(prelude, &mut names);
3394 // Add primitive types to the mix
3395 if filter_fn(Def::PrimTy(TyBool)) {
3396 for (name, _) in &self.primitive_type_table.primitive_types {
3401 // Search in module.
3402 let mod_path = &path[..path.len() - 1];
3403 if let PathResult::Module(module) = self.resolve_path(mod_path, Some(TypeNS),
3405 add_module_candidates(module, &mut names);
3409 let name = path[path.len() - 1].node.name;
3410 // Make sure error reporting is deterministic.
3411 names.sort_by_key(|name| name.as_str());
3412 match find_best_match_for_name(names.iter(), &name.as_str(), None) {
3413 Some(found) if found != name => Some(found),
3418 fn with_resolved_label<F>(&mut self, label: Option<Label>, id: NodeId, f: F)
3419 where F: FnOnce(&mut Resolver)
3421 if let Some(label) = label {
3422 let def = Def::Label(id);
3423 self.with_label_rib(|this| {
3424 this.label_ribs.last_mut().unwrap().bindings.insert(label.ident, def);
3432 fn resolve_labeled_block(&mut self, label: Option<Label>, id: NodeId, block: &Block) {
3433 self.with_resolved_label(label, id, |this| this.visit_block(block));
3436 fn resolve_expr(&mut self, expr: &Expr, parent: Option<&Expr>) {
3437 // First, record candidate traits for this expression if it could
3438 // result in the invocation of a method call.
3440 self.record_candidate_traits_for_expr_if_necessary(expr);
3442 // Next, resolve the node.
3444 ExprKind::Path(ref qself, ref path) => {
3445 self.smart_resolve_path(expr.id, qself.as_ref(), path, PathSource::Expr(parent));
3446 visit::walk_expr(self, expr);
3449 ExprKind::Struct(ref path, ..) => {
3450 self.smart_resolve_path(expr.id, None, path, PathSource::Struct);
3451 visit::walk_expr(self, expr);
3454 ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => {
3455 match self.search_label(label.ident, |rib, id| rib.bindings.get(&id).cloned()) {
3457 // Search again for close matches...
3458 // Picks the first label that is "close enough", which is not necessarily
3459 // the closest match
3460 let close_match = self.search_label(label.ident, |rib, ident| {
3461 let names = rib.bindings.iter().map(|(id, _)| &id.name);
3462 find_best_match_for_name(names, &*ident.name.as_str(), None)
3464 self.record_def(expr.id, err_path_resolution());
3467 ResolutionError::UndeclaredLabel(&label.ident.name.as_str(),
3470 Some(def @ Def::Label(_)) => {
3471 // Since this def is a label, it is never read.
3472 self.record_def(expr.id, PathResolution::new(def));
3475 span_bug!(expr.span, "label wasn't mapped to a label def!");
3479 // visit `break` argument if any
3480 visit::walk_expr(self, expr);
3483 ExprKind::IfLet(ref pattern, ref subexpression, ref if_block, ref optional_else) => {
3484 self.visit_expr(subexpression);
3486 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
3487 self.resolve_pattern(pattern, PatternSource::IfLet, &mut FxHashMap());
3488 self.visit_block(if_block);
3489 self.ribs[ValueNS].pop();
3491 optional_else.as_ref().map(|expr| self.visit_expr(expr));
3494 ExprKind::Loop(ref block, label) => self.resolve_labeled_block(label, expr.id, &block),
3496 ExprKind::While(ref subexpression, ref block, label) => {
3497 self.with_resolved_label(label, expr.id, |this| {
3498 this.visit_expr(subexpression);
3499 this.visit_block(block);
3503 ExprKind::WhileLet(ref pattern, ref subexpression, ref block, label) => {
3504 self.with_resolved_label(label, expr.id, |this| {
3505 this.visit_expr(subexpression);
3506 this.ribs[ValueNS].push(Rib::new(NormalRibKind));
3507 this.resolve_pattern(pattern, PatternSource::WhileLet, &mut FxHashMap());
3508 this.visit_block(block);
3509 this.ribs[ValueNS].pop();
3513 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, label) => {
3514 self.visit_expr(subexpression);
3515 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
3516 self.resolve_pattern(pattern, PatternSource::For, &mut FxHashMap());
3518 self.resolve_labeled_block(label, expr.id, block);
3520 self.ribs[ValueNS].pop();
3523 // Equivalent to `visit::walk_expr` + passing some context to children.
3524 ExprKind::Field(ref subexpression, _) => {
3525 self.resolve_expr(subexpression, Some(expr));
3527 ExprKind::MethodCall(ref segment, ref arguments) => {
3528 let mut arguments = arguments.iter();
3529 self.resolve_expr(arguments.next().unwrap(), Some(expr));
3530 for argument in arguments {
3531 self.resolve_expr(argument, None);
3533 self.visit_path_segment(expr.span, segment);
3536 ExprKind::Repeat(ref element, ref count) => {
3537 self.visit_expr(element);
3538 self.with_constant_rib(|this| {
3539 this.visit_expr(count);
3542 ExprKind::Call(ref callee, ref arguments) => {
3543 self.resolve_expr(callee, Some(expr));
3544 for argument in arguments {
3545 self.resolve_expr(argument, None);
3548 ExprKind::Type(ref type_expr, _) => {
3549 self.current_type_ascription.push(type_expr.span);
3550 visit::walk_expr(self, expr);
3551 self.current_type_ascription.pop();
3554 visit::walk_expr(self, expr);
3559 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3561 ExprKind::Field(_, name) => {
3562 // FIXME(#6890): Even though you can't treat a method like a
3563 // field, we need to add any trait methods we find that match
3564 // the field name so that we can do some nice error reporting
3565 // later on in typeck.
3566 let traits = self.get_traits_containing_item(name.node, ValueNS);
3567 self.trait_map.insert(expr.id, traits);
3569 ExprKind::MethodCall(ref segment, ..) => {
3570 debug!("(recording candidate traits for expr) recording traits for {}",
3572 let traits = self.get_traits_containing_item(segment.identifier, ValueNS);
3573 self.trait_map.insert(expr.id, traits);
3581 fn get_traits_containing_item(&mut self, mut ident: Ident, ns: Namespace)
3582 -> Vec<TraitCandidate> {
3583 debug!("(getting traits containing item) looking for '{}'", ident.name);
3585 let mut found_traits = Vec::new();
3586 // Look for the current trait.
3587 if let Some((module, _)) = self.current_trait_ref {
3588 if self.resolve_ident_in_module(module, ident, ns, false, false, module.span).is_ok() {
3589 let def_id = module.def_id().unwrap();
3590 found_traits.push(TraitCandidate { def_id: def_id, import_id: None });
3594 ident.ctxt = ident.ctxt.modern();
3595 let mut search_module = self.current_module;
3597 self.get_traits_in_module_containing_item(ident, ns, search_module, &mut found_traits);
3599 unwrap_or!(self.hygienic_lexical_parent(search_module, &mut ident.ctxt), break);
3602 if let Some(prelude) = self.prelude {
3603 if !search_module.no_implicit_prelude {
3604 self.get_traits_in_module_containing_item(ident, ns, prelude, &mut found_traits);
3611 fn get_traits_in_module_containing_item(&mut self,
3615 found_traits: &mut Vec<TraitCandidate>) {
3616 let mut traits = module.traits.borrow_mut();
3617 if traits.is_none() {
3618 let mut collected_traits = Vec::new();
3619 module.for_each_child(|name, ns, binding| {
3620 if ns != TypeNS { return }
3621 if let Def::Trait(_) = binding.def() {
3622 collected_traits.push((name, binding));
3625 *traits = Some(collected_traits.into_boxed_slice());
3628 for &(trait_name, binding) in traits.as_ref().unwrap().iter() {
3629 let module = binding.module().unwrap();
3630 let mut ident = ident;
3631 if ident.ctxt.glob_adjust(module.expansion, binding.span.ctxt().modern()).is_none() {
3634 if self.resolve_ident_in_module_unadjusted(module, ident, ns, false, false, module.span)
3636 let import_id = match binding.kind {
3637 NameBindingKind::Import { directive, .. } => {
3638 self.maybe_unused_trait_imports.insert(directive.id);
3639 self.add_to_glob_map(directive.id, trait_name);
3644 let trait_def_id = module.def_id().unwrap();
3645 found_traits.push(TraitCandidate { def_id: trait_def_id, import_id: import_id });
3650 /// When name resolution fails, this method can be used to look up candidate
3651 /// entities with the expected name. It allows filtering them using the
3652 /// supplied predicate (which should be used to only accept the types of
3653 /// definitions expected e.g. traits). The lookup spans across all crates.
3655 /// NOTE: The method does not look into imports, but this is not a problem,
3656 /// since we report the definitions (thus, the de-aliased imports).
3657 fn lookup_import_candidates<FilterFn>(&mut self,
3659 namespace: Namespace,
3660 filter_fn: FilterFn)
3661 -> Vec<ImportSuggestion>
3662 where FilterFn: Fn(Def) -> bool
3664 let mut candidates = Vec::new();
3665 let mut worklist = Vec::new();
3666 let mut seen_modules = FxHashSet();
3667 worklist.push((self.graph_root, Vec::new(), false));
3669 while let Some((in_module,
3671 in_module_is_extern)) = worklist.pop() {
3672 self.populate_module_if_necessary(in_module);
3674 // We have to visit module children in deterministic order to avoid
3675 // instabilities in reported imports (#43552).
3676 in_module.for_each_child_stable(|ident, ns, name_binding| {
3677 // avoid imports entirely
3678 if name_binding.is_import() && !name_binding.is_extern_crate() { return; }
3679 // avoid non-importable candidates as well
3680 if !name_binding.is_importable() { return; }
3682 // collect results based on the filter function
3683 if ident.name == lookup_name && ns == namespace {
3684 if filter_fn(name_binding.def()) {
3686 let mut segms = path_segments.clone();
3687 segms.push(ast::PathSegment::from_ident(ident, name_binding.span));
3689 span: name_binding.span,
3692 // the entity is accessible in the following cases:
3693 // 1. if it's defined in the same crate, it's always
3694 // accessible (since private entities can be made public)
3695 // 2. if it's defined in another crate, it's accessible
3696 // only if both the module is public and the entity is
3697 // declared as public (due to pruning, we don't explore
3698 // outside crate private modules => no need to check this)
3699 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
3700 candidates.push(ImportSuggestion { path: path });
3705 // collect submodules to explore
3706 if let Some(module) = name_binding.module() {
3708 let mut path_segments = path_segments.clone();
3709 path_segments.push(ast::PathSegment::from_ident(ident, name_binding.span));
3711 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
3712 // add the module to the lookup
3713 let is_extern = in_module_is_extern || name_binding.is_extern_crate();
3714 if seen_modules.insert(module.def_id().unwrap()) {
3715 worklist.push((module, path_segments, is_extern));
3725 fn find_module(&mut self,
3727 -> Option<(Module<'a>, ImportSuggestion)>
3729 let mut result = None;
3730 let mut worklist = Vec::new();
3731 let mut seen_modules = FxHashSet();
3732 worklist.push((self.graph_root, Vec::new()));
3734 while let Some((in_module, path_segments)) = worklist.pop() {
3735 // abort if the module is already found
3736 if let Some(_) = result { break; }
3738 self.populate_module_if_necessary(in_module);
3740 in_module.for_each_child_stable(|ident, _, name_binding| {
3741 // abort if the module is already found or if name_binding is private external
3742 if result.is_some() || !name_binding.vis.is_visible_locally() {
3745 if let Some(module) = name_binding.module() {
3747 let mut path_segments = path_segments.clone();
3748 path_segments.push(ast::PathSegment::from_ident(ident, name_binding.span));
3749 if module.def() == Some(module_def) {
3751 span: name_binding.span,
3752 segments: path_segments,
3754 result = Some((module, ImportSuggestion { path: path }));
3756 // add the module to the lookup
3757 if seen_modules.insert(module.def_id().unwrap()) {
3758 worklist.push((module, path_segments));
3768 fn collect_enum_variants(&mut self, enum_def: Def) -> Option<Vec<Path>> {
3769 if let Def::Enum(..) = enum_def {} else {
3770 panic!("Non-enum def passed to collect_enum_variants: {:?}", enum_def)
3773 self.find_module(enum_def).map(|(enum_module, enum_import_suggestion)| {
3774 self.populate_module_if_necessary(enum_module);
3776 let mut variants = Vec::new();
3777 enum_module.for_each_child_stable(|ident, _, name_binding| {
3778 if let Def::Variant(..) = name_binding.def() {
3779 let mut segms = enum_import_suggestion.path.segments.clone();
3780 segms.push(ast::PathSegment::from_ident(ident, name_binding.span));
3781 variants.push(Path {
3782 span: name_binding.span,
3791 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
3792 debug!("(recording def) recording {:?} for {}", resolution, node_id);
3793 if let Some(prev_res) = self.def_map.insert(node_id, resolution) {
3794 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
3798 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
3800 ast::Visibility::Public => ty::Visibility::Public,
3801 ast::Visibility::Crate(..) => ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX)),
3802 ast::Visibility::Inherited => {
3803 ty::Visibility::Restricted(self.current_module.normal_ancestor_id)
3805 ast::Visibility::Restricted { ref path, id } => {
3806 let def = self.smart_resolve_path(id, None, path,
3807 PathSource::Visibility).base_def();
3808 if def == Def::Err {
3809 ty::Visibility::Public
3811 let vis = ty::Visibility::Restricted(def.def_id());
3812 if self.is_accessible(vis) {
3815 self.session.span_err(path.span, "visibilities can only be restricted \
3816 to ancestor modules");
3817 ty::Visibility::Public
3824 fn is_accessible(&self, vis: ty::Visibility) -> bool {
3825 vis.is_accessible_from(self.current_module.normal_ancestor_id, self)
3828 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
3829 vis.is_accessible_from(module.normal_ancestor_id, self)
3832 fn report_errors(&mut self, krate: &Crate) {
3833 self.report_shadowing_errors();
3834 self.report_with_use_injections(krate);
3835 self.report_proc_macro_import(krate);
3836 let mut reported_spans = FxHashSet();
3838 for &AmbiguityError { span, name, b1, b2, lexical, legacy } in &self.ambiguity_errors {
3839 if !reported_spans.insert(span) { continue }
3840 let participle = |binding: &NameBinding| {
3841 if binding.is_import() { "imported" } else { "defined" }
3843 let msg1 = format!("`{}` could refer to the name {} here", name, participle(b1));
3844 let msg2 = format!("`{}` could also refer to the name {} here", name, participle(b2));
3845 let note = if b1.expansion == Mark::root() || !lexical && b1.is_glob_import() {
3846 format!("consider adding an explicit import of `{}` to disambiguate", name)
3847 } else if let Def::Macro(..) = b1.def() {
3848 format!("macro-expanded {} do not shadow",
3849 if b1.is_import() { "macro imports" } else { "macros" })
3851 format!("macro-expanded {} do not shadow when used in a macro invocation path",
3852 if b1.is_import() { "imports" } else { "items" })
3855 let id = match b2.kind {
3856 NameBindingKind::Import { directive, .. } => directive.id,
3857 _ => unreachable!(),
3859 let mut span = MultiSpan::from_span(span);
3860 span.push_span_label(b1.span, msg1);
3861 span.push_span_label(b2.span, msg2);
3862 let msg = format!("`{}` is ambiguous", name);
3863 self.session.buffer_lint(lint::builtin::LEGACY_IMPORTS, id, span, &msg);
3866 struct_span_err!(self.session, span, E0659, "`{}` is ambiguous", name);
3867 err.span_note(b1.span, &msg1);
3869 Def::Macro(..) if b2.span == DUMMY_SP =>
3870 err.note(&format!("`{}` is also a builtin macro", name)),
3871 _ => err.span_note(b2.span, &msg2),
3873 err.note(¬e).emit();
3877 for &PrivacyError(span, name, binding) in &self.privacy_errors {
3878 if !reported_spans.insert(span) { continue }
3879 span_err!(self.session, span, E0603, "{} `{}` is private", binding.descr(), name);
3883 fn report_with_use_injections(&mut self, krate: &Crate) {
3884 for UseError { mut err, candidates, node_id, better } in self.use_injections.drain(..) {
3885 let (span, found_use) = UsePlacementFinder::check(krate, node_id);
3886 if !candidates.is_empty() {
3887 show_candidates(&mut err, span, &candidates, better, found_use);
3893 fn report_shadowing_errors(&mut self) {
3894 for (ident, scope) in replace(&mut self.lexical_macro_resolutions, Vec::new()) {
3895 self.resolve_legacy_scope(scope, ident, true);
3898 let mut reported_errors = FxHashSet();
3899 for binding in replace(&mut self.disallowed_shadowing, Vec::new()) {
3900 if self.resolve_legacy_scope(&binding.parent, binding.ident, false).is_some() &&
3901 reported_errors.insert((binding.ident, binding.span)) {
3902 let msg = format!("`{}` is already in scope", binding.ident);
3903 self.session.struct_span_err(binding.span, &msg)
3904 .note("macro-expanded `macro_rules!`s may not shadow \
3905 existing macros (see RFC 1560)")
3911 fn report_conflict<'b>(&mut self,
3915 new_binding: &NameBinding<'b>,
3916 old_binding: &NameBinding<'b>) {
3917 // Error on the second of two conflicting names
3918 if old_binding.span.lo() > new_binding.span.lo() {
3919 return self.report_conflict(parent, ident, ns, old_binding, new_binding);
3922 let container = match parent.kind {
3923 ModuleKind::Def(Def::Mod(_), _) => "module",
3924 ModuleKind::Def(Def::Trait(_), _) => "trait",
3925 ModuleKind::Block(..) => "block",
3929 let old_noun = match old_binding.is_import() {
3931 false => "definition",
3934 let new_participle = match new_binding.is_import() {
3939 let (name, span) = (ident.name, self.session.codemap().def_span(new_binding.span));
3941 if let Some(s) = self.name_already_seen.get(&name) {
3947 let old_kind = match (ns, old_binding.module()) {
3948 (ValueNS, _) => "value",
3949 (MacroNS, _) => "macro",
3950 (TypeNS, _) if old_binding.is_extern_crate() => "extern crate",
3951 (TypeNS, Some(module)) if module.is_normal() => "module",
3952 (TypeNS, Some(module)) if module.is_trait() => "trait",
3953 (TypeNS, _) => "type",
3956 let namespace = match ns {
3962 let msg = format!("the name `{}` is defined multiple times", name);
3964 let mut err = match (old_binding.is_extern_crate(), new_binding.is_extern_crate()) {
3965 (true, true) => struct_span_err!(self.session, span, E0259, "{}", msg),
3966 (true, _) | (_, true) => match new_binding.is_import() && old_binding.is_import() {
3967 true => struct_span_err!(self.session, span, E0254, "{}", msg),
3968 false => struct_span_err!(self.session, span, E0260, "{}", msg),
3970 _ => match (old_binding.is_import(), new_binding.is_import()) {
3971 (false, false) => struct_span_err!(self.session, span, E0428, "{}", msg),
3972 (true, true) => struct_span_err!(self.session, span, E0252, "{}", msg),
3973 _ => struct_span_err!(self.session, span, E0255, "{}", msg),
3977 err.note(&format!("`{}` must be defined only once in the {} namespace of this {}",
3982 err.span_label(span, format!("`{}` re{} here", name, new_participle));
3983 if old_binding.span != DUMMY_SP {
3984 err.span_label(self.session.codemap().def_span(old_binding.span),
3985 format!("previous {} of the {} `{}` here", old_noun, old_kind, name));
3988 // See https://github.com/rust-lang/rust/issues/32354
3989 if old_binding.is_import() || new_binding.is_import() {
3990 let binding = if new_binding.is_import() && new_binding.span != DUMMY_SP {
3996 let cm = self.session.codemap();
3997 let rename_msg = "You can use `as` to change the binding name of the import";
3999 if let (Ok(snippet), false) = (cm.span_to_snippet(binding.span),
4000 binding.is_renamed_extern_crate()) {
4001 let suggested_name = if name.as_str().chars().next().unwrap().is_uppercase() {
4002 format!("Other{}", name)
4004 format!("other_{}", name)
4007 err.span_suggestion(binding.span,
4009 if snippet.ends_with(';') {
4010 format!("{} as {};",
4011 &snippet[..snippet.len()-1],
4014 format!("{} as {}", snippet, suggested_name)
4017 err.span_label(binding.span, rename_msg);
4022 self.name_already_seen.insert(name, span);
4025 fn warn_legacy_self_import(&self, directive: &'a ImportDirective<'a>) {
4026 let (id, span) = (directive.id, directive.span);
4027 let msg = "`self` no longer imports values";
4028 self.session.buffer_lint(lint::builtin::LEGACY_IMPORTS, id, span, msg);
4031 fn check_proc_macro_attrs(&mut self, attrs: &[ast::Attribute]) {
4032 if self.proc_macro_enabled { return; }
4035 if attr.path.segments.len() > 1 {
4038 let ident = attr.path.segments[0].identifier;
4039 let result = self.resolve_lexical_macro_path_segment(ident,
4043 if let Ok(binding) = result {
4044 if let SyntaxExtension::AttrProcMacro(..) = *binding.binding().get_macro(self) {
4045 attr::mark_known(attr);
4047 let msg = "attribute procedural macros are experimental";
4048 let feature = "proc_macro";
4050 feature_err(&self.session.parse_sess, feature,
4051 attr.span, GateIssue::Language, msg)
4052 .span_label(binding.span(), "procedural macro imported here")
4060 fn is_self_type(path: &[SpannedIdent], namespace: Namespace) -> bool {
4061 namespace == TypeNS && path.len() == 1 && path[0].node.name == keywords::SelfType.name()
4064 fn is_self_value(path: &[SpannedIdent], namespace: Namespace) -> bool {
4065 namespace == ValueNS && path.len() == 1 && path[0].node.name == keywords::SelfValue.name()
4068 fn names_to_string(idents: &[SpannedIdent]) -> String {
4069 let mut result = String::new();
4070 for (i, ident) in idents.iter()
4071 .filter(|i| i.node.name != keywords::CrateRoot.name())
4074 result.push_str("::");
4076 result.push_str(&ident.node.name.as_str());
4081 fn path_names_to_string(path: &Path) -> String {
4082 names_to_string(&path.segments.iter()
4083 .map(|seg| respan(seg.span, seg.identifier))
4084 .collect::<Vec<_>>())
4087 /// Get the path for an enum and the variant from an `ImportSuggestion` for an enum variant.
4088 fn import_candidate_to_paths(suggestion: &ImportSuggestion) -> (Span, String, String) {
4089 let variant_path = &suggestion.path;
4090 let variant_path_string = path_names_to_string(variant_path);
4092 let path_len = suggestion.path.segments.len();
4093 let enum_path = ast::Path {
4094 span: suggestion.path.span,
4095 segments: suggestion.path.segments[0..path_len - 1].to_vec(),
4097 let enum_path_string = path_names_to_string(&enum_path);
4099 (suggestion.path.span, variant_path_string, enum_path_string)
4103 /// When an entity with a given name is not available in scope, we search for
4104 /// entities with that name in all crates. This method allows outputting the
4105 /// results of this search in a programmer-friendly way
4106 fn show_candidates(err: &mut DiagnosticBuilder,
4107 // This is `None` if all placement locations are inside expansions
4109 candidates: &[ImportSuggestion],
4113 // we want consistent results across executions, but candidates are produced
4114 // by iterating through a hash map, so make sure they are ordered:
4115 let mut path_strings: Vec<_> =
4116 candidates.into_iter().map(|c| path_names_to_string(&c.path)).collect();
4117 path_strings.sort();
4119 let better = if better { "better " } else { "" };
4120 let msg_diff = match path_strings.len() {
4121 1 => " is found in another module, you can import it",
4122 _ => "s are found in other modules, you can import them",
4124 let msg = format!("possible {}candidate{} into scope", better, msg_diff);
4126 if let Some(span) = span {
4127 for candidate in &mut path_strings {
4128 // produce an additional newline to separate the new use statement
4129 // from the directly following item.
4130 let additional_newline = if found_use {
4135 *candidate = format!("use {};\n{}", candidate, additional_newline);
4138 err.span_suggestions(span, &msg, path_strings);
4142 for candidate in path_strings {
4144 msg.push_str(&candidate);
4149 /// A somewhat inefficient routine to obtain the name of a module.
4150 fn module_to_string(module: Module) -> Option<String> {
4151 let mut names = Vec::new();
4153 fn collect_mod(names: &mut Vec<Ident>, module: Module) {
4154 if let ModuleKind::Def(_, name) = module.kind {
4155 if let Some(parent) = module.parent {
4156 names.push(Ident::with_empty_ctxt(name));
4157 collect_mod(names, parent);
4160 // danger, shouldn't be ident?
4161 names.push(Ident::from_str("<opaque>"));
4162 collect_mod(names, module.parent.unwrap());
4165 collect_mod(&mut names, module);
4167 if names.is_empty() {
4170 Some(names_to_string(&names.into_iter()
4172 .map(|n| dummy_spanned(n))
4173 .collect::<Vec<_>>()))
4176 fn err_path_resolution() -> PathResolution {
4177 PathResolution::new(Def::Err)
4180 #[derive(PartialEq,Copy, Clone)]
4181 pub enum MakeGlobMap {
4186 #[cfg(not(stage0))] // remove after the next snapshot
4187 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }