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 #![crate_name = "rustc_resolve"]
12 #![crate_type = "dylib"]
13 #![crate_type = "rlib"]
14 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
15 html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
16 html_root_url = "https://doc.rust-lang.org/nightly/")]
19 #![feature(rustc_diagnostic_macros)]
25 extern crate syntax_pos;
26 extern crate rustc_errors as errors;
31 use self::Namespace::*;
32 use self::TypeParameters::*;
35 use rustc::hir::map::{Definitions, DefCollector};
36 use rustc::hir::{self, PrimTy, TyBool, TyChar, TyFloat, TyInt, TyUint, TyStr};
37 use rustc::middle::cstore::CrateLoader;
38 use rustc::session::Session;
40 use rustc::hir::def::*;
41 use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, DefId};
43 use rustc::hir::{Freevar, FreevarMap, TraitCandidate, TraitMap, GlobMap};
44 use rustc::util::nodemap::{NodeMap, NodeSet, FxHashMap, FxHashSet, DefIdMap};
46 use syntax::codemap::{dummy_spanned, respan};
47 use syntax::ext::hygiene::{Mark, SyntaxContext};
48 use syntax::ast::{self, Name, NodeId, Ident, SpannedIdent, FloatTy, IntTy, UintTy};
49 use syntax::ext::base::SyntaxExtension;
50 use syntax::ext::base::Determinacy::{self, Determined, Undetermined};
51 use syntax::ext::base::MacroKind;
52 use syntax::symbol::{Symbol, keywords};
53 use syntax::util::lev_distance::find_best_match_for_name;
55 use syntax::visit::{self, FnKind, Visitor};
57 use syntax::ast::{Arm, BindingMode, Block, Crate, Expr, ExprKind};
58 use syntax::ast::{FnDecl, ForeignItem, ForeignItemKind, Generics};
59 use syntax::ast::{Item, ItemKind, ImplItem, ImplItemKind};
60 use syntax::ast::{Local, Mutability, Pat, PatKind, Path};
61 use syntax::ast::{QSelf, TraitItemKind, TraitRef, Ty, TyKind};
62 use syntax::feature_gate::{feature_err, emit_feature_err, GateIssue};
64 use syntax_pos::{Span, DUMMY_SP, MultiSpan};
65 use errors::DiagnosticBuilder;
67 use std::cell::{Cell, RefCell};
69 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),
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(msp, &msg, "E0408");
230 for sp in target_sp {
231 err.span_label(sp, format!("pattern doesn't bind `{}`", binding_error.name));
233 let origin_sp = binding_error.origin.iter().map(|x| *x).collect::<Vec<_>>();
234 for sp in origin_sp {
235 err.span_label(sp, "variable not in all patterns");
239 ResolutionError::VariableBoundWithDifferentMode(variable_name,
240 first_binding_span) => {
241 let mut err = struct_span_err!(resolver.session,
244 "variable `{}` is bound in inconsistent \
245 ways within the same match arm",
247 err.span_label(span, "bound in different ways");
248 err.span_label(first_binding_span, "first binding");
251 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
252 let mut err = struct_span_err!(resolver.session,
255 "identifier `{}` is bound more than once in this parameter list",
257 err.span_label(span, "used as parameter more than once");
260 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
261 let mut err = struct_span_err!(resolver.session,
264 "identifier `{}` is bound more than once in the same pattern",
266 err.span_label(span, "used in a pattern more than once");
269 ResolutionError::UndeclaredLabel(name) => {
270 let mut err = struct_span_err!(resolver.session,
273 "use of undeclared label `{}`",
275 err.span_label(span, format!("undeclared label `{}`", name));
278 ResolutionError::SelfImportsOnlyAllowedWithin => {
279 struct_span_err!(resolver.session,
283 "`self` imports are only allowed within a { } list")
285 ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
286 struct_span_err!(resolver.session,
289 "`self` import can only appear once in the list")
291 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
292 struct_span_err!(resolver.session,
295 "`self` import can only appear in an import list with a \
298 ResolutionError::UnresolvedImport(name) => {
299 let (span, msg) = match name {
300 Some((sp, n, _)) => (sp, format!("unresolved import `{}`", n)),
301 None => (span, "unresolved import".to_owned()),
303 let mut err = struct_span_err!(resolver.session, span, E0432, "{}", msg);
304 if let Some((_, _, p)) = name {
305 err.span_label(span, p);
309 ResolutionError::FailedToResolve(msg) => {
310 let mut err = struct_span_err!(resolver.session, span, E0433,
311 "failed to resolve. {}", msg);
312 err.span_label(span, msg);
315 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
316 struct_span_err!(resolver.session,
320 "can't capture dynamic environment in a fn item; use the || { ... } \
321 closure form instead")
323 ResolutionError::AttemptToUseNonConstantValueInConstant => {
324 let mut err = struct_span_err!(resolver.session,
327 "attempt to use a non-constant value in a constant");
328 err.span_label(span, "non-constant value");
331 ResolutionError::BindingShadowsSomethingUnacceptable(what_binding, name, binding) => {
332 let shadows_what = PathResolution::new(binding.def()).kind_name();
333 let mut err = struct_span_err!(resolver.session,
336 "{}s cannot shadow {}s", what_binding, shadows_what);
337 err.span_label(span, format!("cannot be named the same as a {}", shadows_what));
338 let participle = if binding.is_import() { "imported" } else { "defined" };
339 let msg = format!("a {} `{}` is {} here", shadows_what, name, participle);
340 err.span_label(binding.span, msg);
343 ResolutionError::ForwardDeclaredTyParam => {
344 let mut err = struct_span_err!(resolver.session, span, E0128,
345 "type parameters with a default cannot use \
346 forward declared identifiers");
347 err.span_label(span, format!("defaulted type parameters \
348 cannot be forward declared"));
354 #[derive(Copy, Clone, Debug)]
357 binding_mode: BindingMode,
360 // Map from the name in a pattern to its binding mode.
361 type BindingMap = FxHashMap<Ident, BindingInfo>;
363 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
374 fn is_refutable(self) -> bool {
376 PatternSource::Match | PatternSource::IfLet | PatternSource::WhileLet => true,
377 PatternSource::Let | PatternSource::For | PatternSource::FnParam => false,
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 PathSource<'a> {
394 // Type paths `Path`.
396 // Trait paths in bounds or impls.
398 // Expression paths `path`, with optional parent context.
399 Expr(Option<&'a Expr>),
400 // Paths in path patterns `Path`.
402 // Paths in struct expressions and patterns `Path { .. }`.
404 // Paths in tuple struct patterns `Path(..)`.
406 // `m::A::B` in `<T as m::A>::B::C`.
407 TraitItem(Namespace),
408 // Path in `pub(path)`
410 // Path in `use a::b::{...};`
414 impl<'a> PathSource<'a> {
415 fn namespace(self) -> Namespace {
417 PathSource::Type | PathSource::Trait | PathSource::Struct |
418 PathSource::Visibility | PathSource::ImportPrefix => TypeNS,
419 PathSource::Expr(..) | PathSource::Pat | PathSource::TupleStruct => ValueNS,
420 PathSource::TraitItem(ns) => ns,
424 fn global_by_default(self) -> bool {
426 PathSource::Visibility | PathSource::ImportPrefix => true,
427 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
428 PathSource::Struct | PathSource::TupleStruct |
429 PathSource::Trait | PathSource::TraitItem(..) => false,
433 fn defer_to_typeck(self) -> bool {
435 PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
436 PathSource::Struct | PathSource::TupleStruct => true,
437 PathSource::Trait | PathSource::TraitItem(..) |
438 PathSource::Visibility | PathSource::ImportPrefix => false,
442 fn descr_expected(self) -> &'static str {
444 PathSource::Type => "type",
445 PathSource::Trait => "trait",
446 PathSource::Pat => "unit struct/variant or constant",
447 PathSource::Struct => "struct, variant or union type",
448 PathSource::TupleStruct => "tuple struct/variant",
449 PathSource::Visibility => "module",
450 PathSource::ImportPrefix => "module or enum",
451 PathSource::TraitItem(ns) => match ns {
452 TypeNS => "associated type",
453 ValueNS => "method or associated constant",
454 MacroNS => bug!("associated macro"),
456 PathSource::Expr(parent) => match parent.map(|p| &p.node) {
457 // "function" here means "anything callable" rather than `Def::Fn`,
458 // this is not precise but usually more helpful than just "value".
459 Some(&ExprKind::Call(..)) => "function",
465 fn is_expected(self, def: Def) -> bool {
467 PathSource::Type => match def {
468 Def::Struct(..) | Def::Union(..) | Def::Enum(..) |
469 Def::Trait(..) | Def::TyAlias(..) | Def::AssociatedTy(..) |
470 Def::PrimTy(..) | Def::TyParam(..) | Def::SelfTy(..) => true,
473 PathSource::Trait => match def {
474 Def::Trait(..) => true,
477 PathSource::Expr(..) => match def {
478 Def::StructCtor(_, CtorKind::Const) | Def::StructCtor(_, CtorKind::Fn) |
479 Def::VariantCtor(_, CtorKind::Const) | Def::VariantCtor(_, CtorKind::Fn) |
480 Def::Const(..) | Def::Static(..) | Def::Local(..) | Def::Upvar(..) |
481 Def::Fn(..) | Def::Method(..) | Def::AssociatedConst(..) => true,
484 PathSource::Pat => match def {
485 Def::StructCtor(_, CtorKind::Const) |
486 Def::VariantCtor(_, CtorKind::Const) |
487 Def::Const(..) | Def::AssociatedConst(..) => true,
490 PathSource::TupleStruct => match def {
491 Def::StructCtor(_, CtorKind::Fn) | Def::VariantCtor(_, CtorKind::Fn) => true,
494 PathSource::Struct => match def {
495 Def::Struct(..) | Def::Union(..) | Def::Variant(..) |
496 Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) => true,
499 PathSource::TraitItem(ns) => match def {
500 Def::AssociatedConst(..) | Def::Method(..) if ns == ValueNS => true,
501 Def::AssociatedTy(..) if ns == TypeNS => true,
504 PathSource::ImportPrefix => match def {
505 Def::Mod(..) | Def::Enum(..) => true,
508 PathSource::Visibility => match def {
509 Def::Mod(..) => true,
515 fn error_code(self, has_unexpected_resolution: bool) -> &'static str {
516 __diagnostic_used!(E0404);
517 __diagnostic_used!(E0405);
518 __diagnostic_used!(E0412);
519 __diagnostic_used!(E0422);
520 __diagnostic_used!(E0423);
521 __diagnostic_used!(E0425);
522 __diagnostic_used!(E0531);
523 __diagnostic_used!(E0532);
524 __diagnostic_used!(E0573);
525 __diagnostic_used!(E0574);
526 __diagnostic_used!(E0575);
527 __diagnostic_used!(E0576);
528 __diagnostic_used!(E0577);
529 __diagnostic_used!(E0578);
530 match (self, has_unexpected_resolution) {
531 (PathSource::Trait, true) => "E0404",
532 (PathSource::Trait, false) => "E0405",
533 (PathSource::Type, true) => "E0573",
534 (PathSource::Type, false) => "E0412",
535 (PathSource::Struct, true) => "E0574",
536 (PathSource::Struct, false) => "E0422",
537 (PathSource::Expr(..), true) => "E0423",
538 (PathSource::Expr(..), false) => "E0425",
539 (PathSource::Pat, true) | (PathSource::TupleStruct, true) => "E0532",
540 (PathSource::Pat, false) | (PathSource::TupleStruct, false) => "E0531",
541 (PathSource::TraitItem(..), true) => "E0575",
542 (PathSource::TraitItem(..), false) => "E0576",
543 (PathSource::Visibility, true) | (PathSource::ImportPrefix, true) => "E0577",
544 (PathSource::Visibility, false) | (PathSource::ImportPrefix, false) => "E0578",
549 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
556 #[derive(Clone, Default, Debug)]
557 pub struct PerNS<T> {
563 impl<T> ::std::ops::Index<Namespace> for PerNS<T> {
565 fn index(&self, ns: Namespace) -> &T {
567 ValueNS => &self.value_ns,
568 TypeNS => &self.type_ns,
569 MacroNS => self.macro_ns.as_ref().unwrap(),
574 impl<T> ::std::ops::IndexMut<Namespace> for PerNS<T> {
575 fn index_mut(&mut self, ns: Namespace) -> &mut T {
577 ValueNS => &mut self.value_ns,
578 TypeNS => &mut self.type_ns,
579 MacroNS => self.macro_ns.as_mut().unwrap(),
584 struct UsePlacementFinder {
585 target_module: NodeId,
590 impl<'tcx> Visitor<'tcx> for UsePlacementFinder {
593 module: &'tcx ast::Mod,
595 _: &[ast::Attribute],
598 if self.span.is_some() {
601 if node_id != self.target_module {
602 visit::walk_mod(self, module);
605 // find a use statement
606 for item in &module.items {
608 ItemKind::Use(..) => {
609 // don't suggest placing a use before the prelude
610 // import or other generated ones
611 if item.span == DUMMY_SP {
612 let mut span = item.span;
614 self.span = Some(span);
615 self.found_use = true;
619 // don't place use before extern crate
620 ItemKind::ExternCrate(_) => {}
621 // but place them before the first other item
622 _ => if self.span.map_or(true, |span| item.span < span ) {
623 let mut span = item.span;
625 self.span = Some(span);
629 assert!(self.span.is_some(), "a file can't have no items and emit suggestions");
633 impl<'a, 'tcx> Visitor<'tcx> for Resolver<'a> {
634 fn visit_item(&mut self, item: &'tcx Item) {
635 self.resolve_item(item);
637 fn visit_arm(&mut self, arm: &'tcx Arm) {
638 self.resolve_arm(arm);
640 fn visit_block(&mut self, block: &'tcx Block) {
641 self.resolve_block(block);
643 fn visit_expr(&mut self, expr: &'tcx Expr) {
644 self.resolve_expr(expr, None);
646 fn visit_local(&mut self, local: &'tcx Local) {
647 self.resolve_local(local);
649 fn visit_ty(&mut self, ty: &'tcx Ty) {
651 TyKind::Path(ref qself, ref path) => {
652 self.smart_resolve_path(ty.id, qself.as_ref(), path, PathSource::Type);
654 TyKind::ImplicitSelf => {
655 let self_ty = keywords::SelfType.ident();
656 let def = self.resolve_ident_in_lexical_scope(self_ty, TypeNS, true, ty.span)
657 .map_or(Def::Err, |d| d.def());
658 self.record_def(ty.id, PathResolution::new(def));
660 TyKind::Array(ref element, ref length) => {
661 self.visit_ty(element);
662 self.with_constant_rib(|this| {
663 this.visit_expr(length);
669 visit::walk_ty(self, ty);
671 fn visit_poly_trait_ref(&mut self,
672 tref: &'tcx ast::PolyTraitRef,
673 m: &'tcx ast::TraitBoundModifier) {
674 self.smart_resolve_path(tref.trait_ref.ref_id, None,
675 &tref.trait_ref.path, PathSource::Trait);
676 visit::walk_poly_trait_ref(self, tref, m);
678 fn visit_variant(&mut self,
679 variant: &'tcx ast::Variant,
680 generics: &'tcx Generics,
681 item_id: ast::NodeId) {
682 if let Some(ref dis_expr) = variant.node.disr_expr {
683 // resolve the discriminator expr as a constant
684 self.with_constant_rib(|this| {
685 this.visit_expr(dis_expr);
689 // `visit::walk_variant` without the discriminant expression.
690 self.visit_variant_data(&variant.node.data,
696 fn visit_foreign_item(&mut self, foreign_item: &'tcx ForeignItem) {
697 let type_parameters = match foreign_item.node {
698 ForeignItemKind::Fn(_, ref generics) => {
699 HasTypeParameters(generics, ItemRibKind)
701 ForeignItemKind::Static(..) => NoTypeParameters,
703 self.with_type_parameter_rib(type_parameters, |this| {
704 visit::walk_foreign_item(this, foreign_item);
707 fn visit_fn(&mut self,
708 function_kind: FnKind<'tcx>,
709 declaration: &'tcx FnDecl,
712 let rib_kind = match function_kind {
713 FnKind::ItemFn(_, generics, ..) => {
714 self.visit_generics(generics);
717 FnKind::Method(_, sig, _, _) => {
718 self.visit_generics(&sig.generics);
719 MethodRibKind(!sig.decl.has_self())
721 FnKind::Closure(_) => ClosureRibKind(node_id),
724 // Create a value rib for the function.
725 self.ribs[ValueNS].push(Rib::new(rib_kind));
727 // Create a label rib for the function.
728 self.label_ribs.push(Rib::new(rib_kind));
730 // Add each argument to the rib.
731 let mut bindings_list = FxHashMap();
732 for argument in &declaration.inputs {
733 self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
735 self.visit_ty(&argument.ty);
737 debug!("(resolving function) recorded argument");
739 visit::walk_fn_ret_ty(self, &declaration.output);
741 // Resolve the function body.
742 match function_kind {
743 FnKind::ItemFn(.., body) |
744 FnKind::Method(.., body) => {
745 self.visit_block(body);
747 FnKind::Closure(body) => {
748 self.visit_expr(body);
752 debug!("(resolving function) leaving function");
754 self.label_ribs.pop();
755 self.ribs[ValueNS].pop();
757 fn visit_generics(&mut self, generics: &'tcx Generics) {
758 // For type parameter defaults, we have to ban access
759 // to following type parameters, as the Substs can only
760 // provide previous type parameters as they're built.
761 let mut default_ban_rib = Rib::new(ForwardTyParamBanRibKind);
762 default_ban_rib.bindings.extend(generics.ty_params.iter()
763 .skip_while(|p| p.default.is_none())
764 .map(|p| (Ident::with_empty_ctxt(p.ident.name), Def::Err)));
766 for param in &generics.ty_params {
767 for bound in ¶m.bounds {
768 self.visit_ty_param_bound(bound);
771 if let Some(ref ty) = param.default {
772 self.ribs[TypeNS].push(default_ban_rib);
774 default_ban_rib = self.ribs[TypeNS].pop().unwrap();
777 // Allow all following defaults to refer to this type parameter.
778 default_ban_rib.bindings.remove(&Ident::with_empty_ctxt(param.ident.name));
780 for lt in &generics.lifetimes { self.visit_lifetime_def(lt); }
781 for p in &generics.where_clause.predicates { self.visit_where_predicate(p); }
785 pub type ErrorMessage = Option<(Span, String)>;
787 #[derive(Copy, Clone)]
788 enum TypeParameters<'a, 'b> {
790 HasTypeParameters(// Type parameters.
793 // The kind of the rib used for type parameters.
797 // The rib kind controls the translation of local
798 // definitions (`Def::Local`) to upvars (`Def::Upvar`).
799 #[derive(Copy, Clone, Debug)]
801 // No translation needs to be applied.
804 // We passed through a closure scope at the given node ID.
805 // Translate upvars as appropriate.
806 ClosureRibKind(NodeId /* func id */),
808 // We passed through an impl or trait and are now in one of its
809 // methods. Allow references to ty params that impl or trait
810 // binds. Disallow any other upvars (including other ty params that are
813 // The boolean value represents the fact that this method is static or not.
816 // We passed through an item scope. Disallow upvars.
819 // We're in a constant item. Can't refer to dynamic stuff.
822 // We passed through a module.
823 ModuleRibKind(Module<'a>),
825 // We passed through a `macro_rules!` statement
826 MacroDefinition(DefId),
828 // All bindings in this rib are type parameters that can't be used
829 // from the default of a type parameter because they're not declared
830 // before said type parameter. Also see the `visit_generics` override.
831 ForwardTyParamBanRibKind,
837 bindings: FxHashMap<Ident, Def>,
842 fn new(kind: RibKind<'a>) -> Rib<'a> {
844 bindings: FxHashMap(),
850 enum LexicalScopeBinding<'a> {
851 Item(&'a NameBinding<'a>),
855 impl<'a> LexicalScopeBinding<'a> {
856 fn item(self) -> Option<&'a NameBinding<'a>> {
858 LexicalScopeBinding::Item(binding) => Some(binding),
863 fn def(self) -> Def {
865 LexicalScopeBinding::Item(binding) => binding.def(),
866 LexicalScopeBinding::Def(def) => def,
872 enum PathResult<'a> {
874 NonModule(PathResolution),
876 Failed(Span, String, bool /* is the error from the last segment? */),
884 /// One node in the tree of modules.
885 pub struct ModuleData<'a> {
886 parent: Option<Module<'a>>,
889 // The def id of the closest normal module (`mod`) ancestor (including this module).
890 normal_ancestor_id: DefId,
892 resolutions: RefCell<FxHashMap<(Ident, Namespace), &'a RefCell<NameResolution<'a>>>>,
893 legacy_macro_resolutions: RefCell<Vec<(Mark, Ident, Span, MacroKind)>>,
894 macro_resolutions: RefCell<Vec<(Box<[Ident]>, Span)>>,
896 // Macro invocations that can expand into items in this module.
897 unresolved_invocations: RefCell<FxHashSet<Mark>>,
899 no_implicit_prelude: bool,
901 glob_importers: RefCell<Vec<&'a ImportDirective<'a>>>,
902 globs: RefCell<Vec<&'a ImportDirective<'a>>>,
904 // Used to memoize the traits in this module for faster searches through all traits in scope.
905 traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>,
907 // Whether this module is populated. If not populated, any attempt to
908 // access the children must be preceded with a
909 // `populate_module_if_necessary` call.
910 populated: Cell<bool>,
912 /// Span of the module itself. Used for error reporting.
918 pub type Module<'a> = &'a ModuleData<'a>;
920 impl<'a> ModuleData<'a> {
921 fn new(parent: Option<Module<'a>>,
923 normal_ancestor_id: DefId,
925 span: Span) -> Self {
930 resolutions: RefCell::new(FxHashMap()),
931 legacy_macro_resolutions: RefCell::new(Vec::new()),
932 macro_resolutions: RefCell::new(Vec::new()),
933 unresolved_invocations: RefCell::new(FxHashSet()),
934 no_implicit_prelude: false,
935 glob_importers: RefCell::new(Vec::new()),
936 globs: RefCell::new((Vec::new())),
937 traits: RefCell::new(None),
938 populated: Cell::new(normal_ancestor_id.is_local()),
944 fn for_each_child<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
945 for (&(ident, ns), name_resolution) in self.resolutions.borrow().iter() {
946 name_resolution.borrow().binding.map(|binding| f(ident, ns, binding));
950 fn for_each_child_stable<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) {
951 let resolutions = self.resolutions.borrow();
952 let mut resolutions = resolutions.iter().map(|(&(ident, ns), &resolution)| {
953 // Pre-compute keys for sorting
954 (ident.name.as_str(), ns, ident, resolution)
956 .collect::<Vec<_>>();
957 resolutions.sort_unstable_by_key(|&(str, ns, ..)| (str, ns));
958 for &(_, ns, ident, resolution) in resolutions.iter() {
959 resolution.borrow().binding.map(|binding| f(ident, ns, binding));
963 fn def(&self) -> Option<Def> {
965 ModuleKind::Def(def, _) => Some(def),
970 fn def_id(&self) -> Option<DefId> {
971 self.def().as_ref().map(Def::def_id)
974 // `self` resolves to the first module ancestor that `is_normal`.
975 fn is_normal(&self) -> bool {
977 ModuleKind::Def(Def::Mod(_), _) => true,
982 fn is_trait(&self) -> bool {
984 ModuleKind::Def(Def::Trait(_), _) => true,
989 fn is_local(&self) -> bool {
990 self.normal_ancestor_id.is_local()
993 fn nearest_item_scope(&'a self) -> Module<'a> {
994 if self.is_trait() { self.parent.unwrap() } else { self }
998 impl<'a> fmt::Debug for ModuleData<'a> {
999 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1000 write!(f, "{:?}", self.def())
1004 // Records a possibly-private value, type, or module definition.
1005 #[derive(Clone, Debug)]
1006 pub struct NameBinding<'a> {
1007 kind: NameBindingKind<'a>,
1010 vis: ty::Visibility,
1013 pub trait ToNameBinding<'a> {
1014 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>;
1017 impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> {
1018 fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
1023 #[derive(Clone, Debug)]
1024 enum NameBindingKind<'a> {
1028 binding: &'a NameBinding<'a>,
1029 directive: &'a ImportDirective<'a>,
1031 legacy_self_import: bool,
1034 b1: &'a NameBinding<'a>,
1035 b2: &'a NameBinding<'a>,
1040 struct PrivacyError<'a>(Span, Name, &'a NameBinding<'a>);
1042 struct UseError<'a> {
1043 err: DiagnosticBuilder<'a>,
1044 /// Attach `use` statements for these candidates
1045 candidates: Vec<ImportSuggestion>,
1046 /// The node id of the module to place the use statements in
1048 /// Whether the diagnostic should state that it's "better"
1052 struct AmbiguityError<'a> {
1056 b1: &'a NameBinding<'a>,
1057 b2: &'a NameBinding<'a>,
1061 impl<'a> NameBinding<'a> {
1062 fn module(&self) -> Option<Module<'a>> {
1064 NameBindingKind::Module(module) => Some(module),
1065 NameBindingKind::Import { binding, .. } => binding.module(),
1066 NameBindingKind::Ambiguity { legacy: true, b1, .. } => b1.module(),
1071 fn def(&self) -> Def {
1073 NameBindingKind::Def(def) => def,
1074 NameBindingKind::Module(module) => module.def().unwrap(),
1075 NameBindingKind::Import { binding, .. } => binding.def(),
1076 NameBindingKind::Ambiguity { legacy: true, b1, .. } => b1.def(),
1077 NameBindingKind::Ambiguity { .. } => Def::Err,
1081 fn def_ignoring_ambiguity(&self) -> Def {
1083 NameBindingKind::Import { binding, .. } => binding.def_ignoring_ambiguity(),
1084 NameBindingKind::Ambiguity { b1, .. } => b1.def_ignoring_ambiguity(),
1089 fn get_macro(&self, resolver: &mut Resolver<'a>) -> Rc<SyntaxExtension> {
1090 resolver.get_macro(self.def_ignoring_ambiguity())
1093 // We sometimes need to treat variants as `pub` for backwards compatibility
1094 fn pseudo_vis(&self) -> ty::Visibility {
1095 if self.is_variant() { ty::Visibility::Public } else { self.vis }
1098 fn is_variant(&self) -> bool {
1100 NameBindingKind::Def(Def::Variant(..)) |
1101 NameBindingKind::Def(Def::VariantCtor(..)) => true,
1106 fn is_extern_crate(&self) -> bool {
1108 NameBindingKind::Import {
1109 directive: &ImportDirective {
1110 subclass: ImportDirectiveSubclass::ExternCrate, ..
1117 fn is_import(&self) -> bool {
1119 NameBindingKind::Import { .. } => true,
1124 fn is_glob_import(&self) -> bool {
1126 NameBindingKind::Import { directive, .. } => directive.is_glob(),
1127 NameBindingKind::Ambiguity { b1, .. } => b1.is_glob_import(),
1132 fn is_importable(&self) -> bool {
1134 Def::AssociatedConst(..) | Def::Method(..) | Def::AssociatedTy(..) => false,
1139 fn is_macro_def(&self) -> bool {
1141 NameBindingKind::Def(Def::Macro(..)) => true,
1146 fn descr(&self) -> &'static str {
1147 if self.is_extern_crate() { "extern crate" } else { self.def().kind_name() }
1151 /// Interns the names of the primitive types.
1152 struct PrimitiveTypeTable {
1153 primitive_types: FxHashMap<Name, PrimTy>,
1156 impl PrimitiveTypeTable {
1157 fn new() -> PrimitiveTypeTable {
1158 let mut table = PrimitiveTypeTable { primitive_types: FxHashMap() };
1160 table.intern("bool", TyBool);
1161 table.intern("char", TyChar);
1162 table.intern("f32", TyFloat(FloatTy::F32));
1163 table.intern("f64", TyFloat(FloatTy::F64));
1164 table.intern("isize", TyInt(IntTy::Is));
1165 table.intern("i8", TyInt(IntTy::I8));
1166 table.intern("i16", TyInt(IntTy::I16));
1167 table.intern("i32", TyInt(IntTy::I32));
1168 table.intern("i64", TyInt(IntTy::I64));
1169 table.intern("i128", TyInt(IntTy::I128));
1170 table.intern("str", TyStr);
1171 table.intern("usize", TyUint(UintTy::Us));
1172 table.intern("u8", TyUint(UintTy::U8));
1173 table.intern("u16", TyUint(UintTy::U16));
1174 table.intern("u32", TyUint(UintTy::U32));
1175 table.intern("u64", TyUint(UintTy::U64));
1176 table.intern("u128", TyUint(UintTy::U128));
1180 fn intern(&mut self, string: &str, primitive_type: PrimTy) {
1181 self.primitive_types.insert(Symbol::intern(string), primitive_type);
1185 /// The main resolver class.
1186 pub struct Resolver<'a> {
1187 session: &'a Session,
1189 pub definitions: Definitions,
1191 graph_root: Module<'a>,
1193 prelude: Option<Module<'a>>,
1195 // n.b. This is used only for better diagnostics, not name resolution itself.
1196 has_self: FxHashSet<DefId>,
1198 // Names of fields of an item `DefId` accessible with dot syntax.
1199 // Used for hints during error reporting.
1200 field_names: FxHashMap<DefId, Vec<Name>>,
1202 // All imports known to succeed or fail.
1203 determined_imports: Vec<&'a ImportDirective<'a>>,
1205 // All non-determined imports.
1206 indeterminate_imports: Vec<&'a ImportDirective<'a>>,
1208 // The module that represents the current item scope.
1209 current_module: Module<'a>,
1211 // The current set of local scopes for types and values.
1212 // FIXME #4948: Reuse ribs to avoid allocation.
1213 ribs: PerNS<Vec<Rib<'a>>>,
1215 // The current set of local scopes, for labels.
1216 label_ribs: Vec<Rib<'a>>,
1218 // The trait that the current context can refer to.
1219 current_trait_ref: Option<(Module<'a>, TraitRef)>,
1221 // The current self type if inside an impl (used for better errors).
1222 current_self_type: Option<Ty>,
1224 // The idents for the primitive types.
1225 primitive_type_table: PrimitiveTypeTable,
1228 pub freevars: FreevarMap,
1229 freevars_seen: NodeMap<NodeMap<usize>>,
1230 pub export_map: ExportMap,
1231 pub trait_map: TraitMap,
1233 // A map from nodes to anonymous modules.
1234 // Anonymous modules are pseudo-modules that are implicitly created around items
1235 // contained within blocks.
1237 // For example, if we have this:
1245 // There will be an anonymous module created around `g` with the ID of the
1246 // entry block for `f`.
1247 block_map: NodeMap<Module<'a>>,
1248 module_map: FxHashMap<DefId, Module<'a>>,
1249 extern_module_map: FxHashMap<(DefId, bool /* MacrosOnly? */), Module<'a>>,
1251 pub make_glob_map: bool,
1252 /// Maps imports to the names of items actually imported (this actually maps
1253 /// all imports, but only glob imports are actually interesting).
1254 pub glob_map: GlobMap,
1256 used_imports: FxHashSet<(NodeId, Namespace)>,
1257 pub maybe_unused_trait_imports: NodeSet,
1259 /// privacy errors are delayed until the end in order to deduplicate them
1260 privacy_errors: Vec<PrivacyError<'a>>,
1261 /// ambiguity errors are delayed for deduplication
1262 ambiguity_errors: Vec<AmbiguityError<'a>>,
1263 /// `use` injections are delayed for better placement and deduplication
1264 use_injections: Vec<UseError<'a>>,
1266 gated_errors: FxHashSet<Span>,
1267 disallowed_shadowing: Vec<&'a LegacyBinding<'a>>,
1269 arenas: &'a ResolverArenas<'a>,
1270 dummy_binding: &'a NameBinding<'a>,
1271 use_extern_macros: bool, // true if `#![feature(use_extern_macros)]`
1273 crate_loader: &'a mut CrateLoader,
1274 macro_names: FxHashSet<Ident>,
1275 global_macros: FxHashMap<Name, &'a NameBinding<'a>>,
1276 lexical_macro_resolutions: Vec<(Ident, &'a Cell<LegacyScope<'a>>)>,
1277 macro_map: FxHashMap<DefId, Rc<SyntaxExtension>>,
1278 macro_defs: FxHashMap<Mark, DefId>,
1279 local_macro_def_scopes: FxHashMap<NodeId, Module<'a>>,
1280 macro_exports: Vec<Export>,
1281 pub whitelisted_legacy_custom_derives: Vec<Name>,
1282 pub found_unresolved_macro: bool,
1284 // List of crate local macros that we need to warn about as being unused.
1285 // Right now this only includes macro_rules! macros, and macros 2.0.
1286 unused_macros: FxHashSet<DefId>,
1288 // Maps the `Mark` of an expansion to its containing module or block.
1289 invocations: FxHashMap<Mark, &'a InvocationData<'a>>,
1291 // Avoid duplicated errors for "name already defined".
1292 name_already_seen: FxHashMap<Name, Span>,
1294 // If `#![feature(proc_macro)]` is set
1295 proc_macro_enabled: bool,
1297 // A set of procedural macros imported by `#[macro_use]` that have already been warned about
1298 warned_proc_macros: FxHashSet<Name>,
1300 potentially_unused_imports: Vec<&'a ImportDirective<'a>>,
1302 // This table maps struct IDs into struct constructor IDs,
1303 // it's not used during normal resolution, only for better error reporting.
1304 struct_constructors: DefIdMap<(Def, ty::Visibility)>,
1306 // Only used for better errors on `fn(): fn()`
1307 current_type_ascription: Vec<Span>,
1310 pub struct ResolverArenas<'a> {
1311 modules: arena::TypedArena<ModuleData<'a>>,
1312 local_modules: RefCell<Vec<Module<'a>>>,
1313 name_bindings: arena::TypedArena<NameBinding<'a>>,
1314 import_directives: arena::TypedArena<ImportDirective<'a>>,
1315 name_resolutions: arena::TypedArena<RefCell<NameResolution<'a>>>,
1316 invocation_data: arena::TypedArena<InvocationData<'a>>,
1317 legacy_bindings: arena::TypedArena<LegacyBinding<'a>>,
1320 impl<'a> ResolverArenas<'a> {
1321 fn alloc_module(&'a self, module: ModuleData<'a>) -> Module<'a> {
1322 let module = self.modules.alloc(module);
1323 if module.def_id().map(|def_id| def_id.is_local()).unwrap_or(true) {
1324 self.local_modules.borrow_mut().push(module);
1328 fn local_modules(&'a self) -> ::std::cell::Ref<'a, Vec<Module<'a>>> {
1329 self.local_modules.borrow()
1331 fn alloc_name_binding(&'a self, name_binding: NameBinding<'a>) -> &'a NameBinding<'a> {
1332 self.name_bindings.alloc(name_binding)
1334 fn alloc_import_directive(&'a self, import_directive: ImportDirective<'a>)
1335 -> &'a ImportDirective {
1336 self.import_directives.alloc(import_directive)
1338 fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
1339 self.name_resolutions.alloc(Default::default())
1341 fn alloc_invocation_data(&'a self, expansion_data: InvocationData<'a>)
1342 -> &'a InvocationData<'a> {
1343 self.invocation_data.alloc(expansion_data)
1345 fn alloc_legacy_binding(&'a self, binding: LegacyBinding<'a>) -> &'a LegacyBinding<'a> {
1346 self.legacy_bindings.alloc(binding)
1350 impl<'a, 'b: 'a> ty::DefIdTree for &'a Resolver<'b> {
1351 fn parent(self, id: DefId) -> Option<DefId> {
1353 LOCAL_CRATE => self.definitions.def_key(id.index).parent,
1354 _ => self.session.cstore.def_key(id).parent,
1355 }.map(|index| DefId { index: index, ..id })
1359 impl<'a> hir::lowering::Resolver for Resolver<'a> {
1360 fn resolve_hir_path(&mut self, path: &mut hir::Path, is_value: bool) {
1361 let namespace = if is_value { ValueNS } else { TypeNS };
1362 let hir::Path { ref segments, span, ref mut def } = *path;
1363 let path: Vec<SpannedIdent> = segments.iter()
1364 .map(|seg| respan(span, Ident::with_empty_ctxt(seg.name)))
1366 match self.resolve_path(&path, Some(namespace), true, span) {
1367 PathResult::Module(module) => *def = module.def().unwrap(),
1368 PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 =>
1369 *def = path_res.base_def(),
1370 PathResult::NonModule(..) => match self.resolve_path(&path, None, true, span) {
1371 PathResult::Failed(span, msg, _) => {
1372 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
1376 PathResult::Indeterminate => unreachable!(),
1377 PathResult::Failed(span, msg, _) => {
1378 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
1383 fn get_resolution(&mut self, id: NodeId) -> Option<PathResolution> {
1384 self.def_map.get(&id).cloned()
1387 fn definitions(&mut self) -> &mut Definitions {
1388 &mut self.definitions
1392 impl<'a> Resolver<'a> {
1393 pub fn new(session: &'a Session,
1396 make_glob_map: MakeGlobMap,
1397 crate_loader: &'a mut CrateLoader,
1398 arenas: &'a ResolverArenas<'a>)
1400 let root_def_id = DefId::local(CRATE_DEF_INDEX);
1401 let root_module_kind = ModuleKind::Def(Def::Mod(root_def_id), keywords::Invalid.name());
1402 let graph_root = arenas.alloc_module(ModuleData {
1403 no_implicit_prelude: attr::contains_name(&krate.attrs, "no_implicit_prelude"),
1404 ..ModuleData::new(None, root_module_kind, root_def_id, Mark::root(), krate.span)
1406 let mut module_map = FxHashMap();
1407 module_map.insert(DefId::local(CRATE_DEF_INDEX), graph_root);
1409 let mut definitions = Definitions::new();
1410 DefCollector::new(&mut definitions, Mark::root())
1411 .collect_root(crate_name, &session.local_crate_disambiguator().as_str());
1413 let mut invocations = FxHashMap();
1414 invocations.insert(Mark::root(),
1415 arenas.alloc_invocation_data(InvocationData::root(graph_root)));
1417 let features = session.features.borrow();
1419 let mut macro_defs = FxHashMap();
1420 macro_defs.insert(Mark::root(), root_def_id);
1427 // The outermost module has def ID 0; this is not reflected in the
1432 has_self: FxHashSet(),
1433 field_names: FxHashMap(),
1435 determined_imports: Vec::new(),
1436 indeterminate_imports: Vec::new(),
1438 current_module: graph_root,
1440 value_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1441 type_ns: vec![Rib::new(ModuleRibKind(graph_root))],
1442 macro_ns: Some(vec![Rib::new(ModuleRibKind(graph_root))]),
1444 label_ribs: Vec::new(),
1446 current_trait_ref: None,
1447 current_self_type: None,
1449 primitive_type_table: PrimitiveTypeTable::new(),
1452 freevars: NodeMap(),
1453 freevars_seen: NodeMap(),
1454 export_map: NodeMap(),
1455 trait_map: NodeMap(),
1457 block_map: NodeMap(),
1458 extern_module_map: FxHashMap(),
1460 make_glob_map: make_glob_map == MakeGlobMap::Yes,
1461 glob_map: NodeMap(),
1463 used_imports: FxHashSet(),
1464 maybe_unused_trait_imports: NodeSet(),
1466 privacy_errors: Vec::new(),
1467 ambiguity_errors: Vec::new(),
1468 use_injections: Vec::new(),
1469 gated_errors: FxHashSet(),
1470 disallowed_shadowing: Vec::new(),
1473 dummy_binding: arenas.alloc_name_binding(NameBinding {
1474 kind: NameBindingKind::Def(Def::Err),
1475 expansion: Mark::root(),
1477 vis: ty::Visibility::Public,
1480 // The `proc_macro` and `decl_macro` features imply `use_extern_macros`
1482 features.use_extern_macros || features.proc_macro || features.decl_macro,
1485 macro_names: FxHashSet(),
1486 global_macros: FxHashMap(),
1487 lexical_macro_resolutions: Vec::new(),
1488 macro_map: FxHashMap(),
1489 macro_exports: Vec::new(),
1492 local_macro_def_scopes: FxHashMap(),
1493 name_already_seen: FxHashMap(),
1494 whitelisted_legacy_custom_derives: Vec::new(),
1495 proc_macro_enabled: features.proc_macro,
1496 warned_proc_macros: FxHashSet(),
1497 potentially_unused_imports: Vec::new(),
1498 struct_constructors: DefIdMap(),
1499 found_unresolved_macro: false,
1500 unused_macros: FxHashSet(),
1501 current_type_ascription: Vec::new(),
1505 pub fn arenas() -> ResolverArenas<'a> {
1507 modules: arena::TypedArena::new(),
1508 local_modules: RefCell::new(Vec::new()),
1509 name_bindings: arena::TypedArena::new(),
1510 import_directives: arena::TypedArena::new(),
1511 name_resolutions: arena::TypedArena::new(),
1512 invocation_data: arena::TypedArena::new(),
1513 legacy_bindings: arena::TypedArena::new(),
1517 fn per_ns<T, F: FnMut(&mut Self, Namespace) -> T>(&mut self, mut f: F) -> PerNS<T> {
1519 type_ns: f(self, TypeNS),
1520 value_ns: f(self, ValueNS),
1521 macro_ns: match self.use_extern_macros {
1522 true => Some(f(self, MacroNS)),
1528 /// Entry point to crate resolution.
1529 pub fn resolve_crate(&mut self, krate: &Crate) {
1530 ImportResolver { resolver: self }.finalize_imports();
1531 self.current_module = self.graph_root;
1532 self.finalize_current_module_macro_resolutions();
1534 visit::walk_crate(self, krate);
1536 check_unused::check_crate(self, krate);
1537 self.report_errors(krate);
1538 self.crate_loader.postprocess(krate);
1545 normal_ancestor_id: DefId,
1549 let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expansion, span);
1550 self.arenas.alloc_module(module)
1553 fn record_use(&mut self, ident: Ident, ns: Namespace, binding: &'a NameBinding<'a>, span: Span)
1554 -> bool /* true if an error was reported */ {
1555 match binding.kind {
1556 NameBindingKind::Import { directive, binding, ref used, legacy_self_import }
1559 directive.used.set(true);
1560 if legacy_self_import {
1561 self.warn_legacy_self_import(directive);
1564 self.used_imports.insert((directive.id, ns));
1565 self.add_to_glob_map(directive.id, ident);
1566 self.record_use(ident, ns, binding, span)
1568 NameBindingKind::Import { .. } => false,
1569 NameBindingKind::Ambiguity { b1, b2, legacy } => {
1570 self.ambiguity_errors.push(AmbiguityError {
1571 span: span, name: ident.name, lexical: false, b1: b1, b2: b2, legacy,
1574 self.record_use(ident, ns, b1, span);
1582 fn add_to_glob_map(&mut self, id: NodeId, ident: Ident) {
1583 if self.make_glob_map {
1584 self.glob_map.entry(id).or_insert_with(FxHashSet).insert(ident.name);
1588 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1589 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1590 /// `ident` in the first scope that defines it (or None if no scopes define it).
1592 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1593 /// the items are defined in the block. For example,
1596 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1599 /// g(); // This resolves to the local variable `g` since it shadows the item.
1603 /// Invariant: This must only be called during main resolution, not during
1604 /// import resolution.
1605 fn resolve_ident_in_lexical_scope(&mut self,
1610 -> Option<LexicalScopeBinding<'a>> {
1612 ident.ctxt = if ident.name == keywords::SelfType.name() {
1613 SyntaxContext::empty() // FIXME(jseyfried) improve `Self` hygiene
1619 // Walk backwards up the ribs in scope.
1620 let mut module = self.graph_root;
1621 for i in (0 .. self.ribs[ns].len()).rev() {
1622 if let Some(def) = self.ribs[ns][i].bindings.get(&ident).cloned() {
1623 // The ident resolves to a type parameter or local variable.
1624 return Some(LexicalScopeBinding::Def(
1625 self.adjust_local_def(ns, i, def, record_used, path_span)
1629 module = match self.ribs[ns][i].kind {
1630 ModuleRibKind(module) => module,
1631 MacroDefinition(def) if def == self.macro_defs[&ident.ctxt.outer()] => {
1632 // If an invocation of this macro created `ident`, give up on `ident`
1633 // and switch to `ident`'s source from the macro definition.
1634 ident.ctxt.remove_mark();
1640 let item = self.resolve_ident_in_module_unadjusted(
1641 module, ident, ns, false, record_used, path_span,
1643 if let Ok(binding) = item {
1644 // The ident resolves to an item.
1645 return Some(LexicalScopeBinding::Item(binding));
1649 ModuleKind::Block(..) => {}, // We can see through blocks
1654 ident.ctxt = ident.ctxt.modern();
1656 module = unwrap_or!(self.hygienic_lexical_parent(module, &mut ident.ctxt), break);
1657 let orig_current_module = self.current_module;
1658 self.current_module = module; // Lexical resolutions can never be a privacy error.
1659 let result = self.resolve_ident_in_module_unadjusted(
1660 module, ident, ns, false, record_used, path_span,
1662 self.current_module = orig_current_module;
1665 Ok(binding) => return Some(LexicalScopeBinding::Item(binding)),
1666 Err(Undetermined) => return None,
1667 Err(Determined) => {}
1671 match self.prelude {
1672 Some(prelude) if !module.no_implicit_prelude => {
1673 self.resolve_ident_in_module_unadjusted(prelude, ident, ns, false, false, path_span)
1674 .ok().map(LexicalScopeBinding::Item)
1680 fn hygienic_lexical_parent(&mut self, mut module: Module<'a>, ctxt: &mut SyntaxContext)
1681 -> Option<Module<'a>> {
1682 if !module.expansion.is_descendant_of(ctxt.outer()) {
1683 return Some(self.macro_def_scope(ctxt.remove_mark()));
1686 if let ModuleKind::Block(..) = module.kind {
1687 return Some(module.parent.unwrap());
1690 let mut module_expansion = module.expansion.modern(); // for backward compatibility
1691 while let Some(parent) = module.parent {
1692 let parent_expansion = parent.expansion.modern();
1693 if module_expansion.is_descendant_of(parent_expansion) &&
1694 parent_expansion != module_expansion {
1695 return if parent_expansion.is_descendant_of(ctxt.outer()) {
1702 module_expansion = parent_expansion;
1708 fn resolve_ident_in_module(&mut self,
1712 ignore_unresolved_invocations: bool,
1715 -> Result<&'a NameBinding<'a>, Determinacy> {
1716 ident.ctxt = ident.ctxt.modern();
1717 let orig_current_module = self.current_module;
1718 if let Some(def) = ident.ctxt.adjust(module.expansion) {
1719 self.current_module = self.macro_def_scope(def);
1721 let result = self.resolve_ident_in_module_unadjusted(
1722 module, ident, ns, ignore_unresolved_invocations, record_used, span,
1724 self.current_module = orig_current_module;
1728 fn resolve_crate_root(&mut self, mut ctxt: SyntaxContext) -> Module<'a> {
1729 let module = match ctxt.adjust(Mark::root()) {
1730 Some(def) => self.macro_def_scope(def),
1731 None => return self.graph_root,
1733 self.get_module(DefId { index: CRATE_DEF_INDEX, ..module.normal_ancestor_id })
1736 fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
1737 let mut module = self.get_module(module.normal_ancestor_id);
1738 while module.span.ctxt.modern() != *ctxt {
1739 let parent = module.parent.unwrap_or_else(|| self.macro_def_scope(ctxt.remove_mark()));
1740 module = self.get_module(parent.normal_ancestor_id);
1747 // We maintain a list of value ribs and type ribs.
1749 // Simultaneously, we keep track of the current position in the module
1750 // graph in the `current_module` pointer. When we go to resolve a name in
1751 // the value or type namespaces, we first look through all the ribs and
1752 // then query the module graph. When we resolve a name in the module
1753 // namespace, we can skip all the ribs (since nested modules are not
1754 // allowed within blocks in Rust) and jump straight to the current module
1757 // Named implementations are handled separately. When we find a method
1758 // call, we consult the module node to find all of the implementations in
1759 // scope. This information is lazily cached in the module node. We then
1760 // generate a fake "implementation scope" containing all the
1761 // implementations thus found, for compatibility with old resolve pass.
1763 fn with_scope<F>(&mut self, id: NodeId, f: F)
1764 where F: FnOnce(&mut Resolver)
1766 let id = self.definitions.local_def_id(id);
1767 let module = self.module_map.get(&id).cloned(); // clones a reference
1768 if let Some(module) = module {
1769 // Move down in the graph.
1770 let orig_module = replace(&mut self.current_module, module);
1771 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(module)));
1772 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(module)));
1774 self.finalize_current_module_macro_resolutions();
1777 self.current_module = orig_module;
1778 self.ribs[ValueNS].pop();
1779 self.ribs[TypeNS].pop();
1785 /// Searches the current set of local scopes for labels.
1786 /// Stops after meeting a closure.
1787 fn search_label(&self, mut ident: Ident) -> Option<Def> {
1788 for rib in self.label_ribs.iter().rev() {
1791 // If an invocation of this macro created `ident`, give up on `ident`
1792 // and switch to `ident`'s source from the macro definition.
1793 MacroDefinition(def) => {
1794 if def == self.macro_defs[&ident.ctxt.outer()] {
1795 ident.ctxt.remove_mark();
1799 // Do not resolve labels across function boundary
1803 let result = rib.bindings.get(&ident).cloned();
1804 if result.is_some() {
1811 fn resolve_item(&mut self, item: &Item) {
1812 let name = item.ident.name;
1814 debug!("(resolving item) resolving {}", name);
1816 self.check_proc_macro_attrs(&item.attrs);
1819 ItemKind::Enum(_, ref generics) |
1820 ItemKind::Ty(_, ref generics) |
1821 ItemKind::Struct(_, ref generics) |
1822 ItemKind::Union(_, ref generics) |
1823 ItemKind::Fn(.., ref generics, _) => {
1824 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind),
1825 |this| visit::walk_item(this, item));
1828 ItemKind::DefaultImpl(_, ref trait_ref) => {
1829 self.with_optional_trait_ref(Some(trait_ref), |this, _| {
1830 // Resolve type arguments in trait path
1831 visit::walk_trait_ref(this, trait_ref);
1834 ItemKind::Impl(.., ref generics, ref opt_trait_ref, ref self_type, ref impl_items) =>
1835 self.resolve_implementation(generics,
1841 ItemKind::Trait(_, ref generics, ref bounds, ref trait_items) => {
1842 // Create a new rib for the trait-wide type parameters.
1843 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
1844 let local_def_id = this.definitions.local_def_id(item.id);
1845 this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
1846 this.visit_generics(generics);
1847 walk_list!(this, visit_ty_param_bound, bounds);
1849 for trait_item in trait_items {
1850 this.check_proc_macro_attrs(&trait_item.attrs);
1852 match trait_item.node {
1853 TraitItemKind::Const(ref ty, ref default) => {
1856 // Only impose the restrictions of
1857 // ConstRibKind for an actual constant
1858 // expression in a provided default.
1859 if let Some(ref expr) = *default{
1860 this.with_constant_rib(|this| {
1861 this.visit_expr(expr);
1865 TraitItemKind::Method(ref sig, _) => {
1866 let type_parameters =
1867 HasTypeParameters(&sig.generics,
1868 MethodRibKind(!sig.decl.has_self()));
1869 this.with_type_parameter_rib(type_parameters, |this| {
1870 visit::walk_trait_item(this, trait_item)
1873 TraitItemKind::Type(..) => {
1874 this.with_type_parameter_rib(NoTypeParameters, |this| {
1875 visit::walk_trait_item(this, trait_item)
1878 TraitItemKind::Macro(_) => panic!("unexpanded macro in resolve!"),
1885 ItemKind::Mod(_) | ItemKind::ForeignMod(_) => {
1886 self.with_scope(item.id, |this| {
1887 visit::walk_item(this, item);
1891 ItemKind::Static(ref ty, _, ref expr) |
1892 ItemKind::Const(ref ty, ref expr) => {
1893 self.with_item_rib(|this| {
1895 this.with_constant_rib(|this| {
1896 this.visit_expr(expr);
1901 ItemKind::Use(ref view_path) => {
1902 match view_path.node {
1903 ast::ViewPathList(ref prefix, ref items) if items.is_empty() => {
1904 // Resolve prefix of an import with empty braces (issue #28388).
1905 self.smart_resolve_path(item.id, None, prefix, PathSource::ImportPrefix);
1911 ItemKind::ExternCrate(_) | ItemKind::MacroDef(..) | ItemKind::GlobalAsm(_)=> {
1912 // do nothing, these are just around to be encoded
1915 ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"),
1919 fn with_type_parameter_rib<'b, F>(&'b mut self, type_parameters: TypeParameters<'a, 'b>, f: F)
1920 where F: FnOnce(&mut Resolver)
1922 match type_parameters {
1923 HasTypeParameters(generics, rib_kind) => {
1924 let mut function_type_rib = Rib::new(rib_kind);
1925 let mut seen_bindings = FxHashMap();
1926 for type_parameter in &generics.ty_params {
1927 let ident = type_parameter.ident.modern();
1928 debug!("with_type_parameter_rib: {}", type_parameter.id);
1930 if seen_bindings.contains_key(&ident) {
1931 let span = seen_bindings.get(&ident).unwrap();
1933 ResolutionError::NameAlreadyUsedInTypeParameterList(ident.name, span);
1934 resolve_error(self, type_parameter.span, err);
1936 seen_bindings.entry(ident).or_insert(type_parameter.span);
1938 // plain insert (no renaming)
1939 let def_id = self.definitions.local_def_id(type_parameter.id);
1940 let def = Def::TyParam(def_id);
1941 function_type_rib.bindings.insert(ident, def);
1942 self.record_def(type_parameter.id, PathResolution::new(def));
1944 self.ribs[TypeNS].push(function_type_rib);
1947 NoTypeParameters => {
1954 if let HasTypeParameters(..) = type_parameters {
1955 self.ribs[TypeNS].pop();
1959 fn with_label_rib<F>(&mut self, f: F)
1960 where F: FnOnce(&mut Resolver)
1962 self.label_ribs.push(Rib::new(NormalRibKind));
1964 self.label_ribs.pop();
1967 fn with_item_rib<F>(&mut self, f: F)
1968 where F: FnOnce(&mut Resolver)
1970 self.ribs[ValueNS].push(Rib::new(ItemRibKind));
1971 self.ribs[TypeNS].push(Rib::new(ItemRibKind));
1973 self.ribs[TypeNS].pop();
1974 self.ribs[ValueNS].pop();
1977 fn with_constant_rib<F>(&mut self, f: F)
1978 where F: FnOnce(&mut Resolver)
1980 self.ribs[ValueNS].push(Rib::new(ConstantItemRibKind));
1982 self.ribs[ValueNS].pop();
1985 fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
1986 where F: FnOnce(&mut Resolver) -> T
1988 // Handle nested impls (inside fn bodies)
1989 let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
1990 let result = f(self);
1991 self.current_self_type = previous_value;
1995 fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
1996 where F: FnOnce(&mut Resolver, Option<DefId>) -> T
1998 let mut new_val = None;
1999 let mut new_id = None;
2000 if let Some(trait_ref) = opt_trait_ref {
2001 let path: Vec<_> = trait_ref.path.segments.iter()
2002 .map(|seg| respan(seg.span, seg.identifier))
2004 let def = self.smart_resolve_path_fragment(trait_ref.ref_id,
2007 trait_ref.path.span,
2008 trait_ref.path.segments.last().unwrap().span,
2011 if def != Def::Err {
2012 new_id = Some(def.def_id());
2013 let span = trait_ref.path.span;
2014 if let PathResult::Module(module) = self.resolve_path(&path, None, false, span) {
2015 new_val = Some((module, trait_ref.clone()));
2019 let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
2020 let result = f(self, new_id);
2021 self.current_trait_ref = original_trait_ref;
2025 fn with_self_rib<F>(&mut self, self_def: Def, f: F)
2026 where F: FnOnce(&mut Resolver)
2028 let mut self_type_rib = Rib::new(NormalRibKind);
2030 // plain insert (no renaming, types are not currently hygienic....)
2031 self_type_rib.bindings.insert(keywords::SelfType.ident(), self_def);
2032 self.ribs[TypeNS].push(self_type_rib);
2034 self.ribs[TypeNS].pop();
2037 fn resolve_implementation(&mut self,
2038 generics: &Generics,
2039 opt_trait_reference: &Option<TraitRef>,
2042 impl_items: &[ImplItem]) {
2043 // If applicable, create a rib for the type parameters.
2044 self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
2045 // Dummy self type for better errors if `Self` is used in the trait path.
2046 this.with_self_rib(Def::SelfTy(None, None), |this| {
2047 // Resolve the trait reference, if necessary.
2048 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
2049 let item_def_id = this.definitions.local_def_id(item_id);
2050 this.with_self_rib(Def::SelfTy(trait_id, Some(item_def_id)), |this| {
2051 if let Some(trait_ref) = opt_trait_reference.as_ref() {
2052 // Resolve type arguments in trait path
2053 visit::walk_trait_ref(this, trait_ref);
2055 // Resolve the self type.
2056 this.visit_ty(self_type);
2057 // Resolve the type parameters.
2058 this.visit_generics(generics);
2059 this.with_current_self_type(self_type, |this| {
2060 for impl_item in impl_items {
2061 this.check_proc_macro_attrs(&impl_item.attrs);
2062 this.resolve_visibility(&impl_item.vis);
2063 match impl_item.node {
2064 ImplItemKind::Const(..) => {
2065 // If this is a trait impl, ensure the const
2067 this.check_trait_item(impl_item.ident,
2070 |n, s| ResolutionError::ConstNotMemberOfTrait(n, s));
2071 visit::walk_impl_item(this, impl_item);
2073 ImplItemKind::Method(ref sig, _) => {
2074 // If this is a trait impl, ensure the method
2076 this.check_trait_item(impl_item.ident,
2079 |n, s| ResolutionError::MethodNotMemberOfTrait(n, s));
2081 // We also need a new scope for the method-
2082 // specific type parameters.
2083 let type_parameters =
2084 HasTypeParameters(&sig.generics,
2085 MethodRibKind(!sig.decl.has_self()));
2086 this.with_type_parameter_rib(type_parameters, |this| {
2087 visit::walk_impl_item(this, impl_item);
2090 ImplItemKind::Type(ref ty) => {
2091 // If this is a trait impl, ensure the type
2093 this.check_trait_item(impl_item.ident,
2096 |n, s| ResolutionError::TypeNotMemberOfTrait(n, s));
2100 ImplItemKind::Macro(_) =>
2101 panic!("unexpanded macro in resolve!"),
2111 fn check_trait_item<F>(&mut self, ident: Ident, ns: Namespace, span: Span, err: F)
2112 where F: FnOnce(Name, &str) -> ResolutionError
2114 // If there is a TraitRef in scope for an impl, then the method must be in the
2116 if let Some((module, _)) = self.current_trait_ref {
2117 if self.resolve_ident_in_module(module, ident, ns, false, false, span).is_err() {
2118 let path = &self.current_trait_ref.as_ref().unwrap().1.path;
2119 resolve_error(self, span, err(ident.name, &path_names_to_string(path)));
2124 fn resolve_local(&mut self, local: &Local) {
2125 // Resolve the type.
2126 walk_list!(self, visit_ty, &local.ty);
2128 // Resolve the initializer.
2129 walk_list!(self, visit_expr, &local.init);
2131 // Resolve the pattern.
2132 self.resolve_pattern(&local.pat, PatternSource::Let, &mut FxHashMap());
2135 // build a map from pattern identifiers to binding-info's.
2136 // this is done hygienically. This could arise for a macro
2137 // that expands into an or-pattern where one 'x' was from the
2138 // user and one 'x' came from the macro.
2139 fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
2140 let mut binding_map = FxHashMap();
2142 pat.walk(&mut |pat| {
2143 if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node {
2144 if sub_pat.is_some() || match self.def_map.get(&pat.id).map(|res| res.base_def()) {
2145 Some(Def::Local(..)) => true,
2148 let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode };
2149 binding_map.insert(ident.node, binding_info);
2158 // check that all of the arms in an or-pattern have exactly the
2159 // same set of bindings, with the same binding modes for each.
2160 fn check_consistent_bindings(&mut self, arm: &Arm) {
2161 if arm.pats.is_empty() {
2165 let mut missing_vars = FxHashMap();
2166 let mut inconsistent_vars = FxHashMap();
2167 for (i, p) in arm.pats.iter().enumerate() {
2168 let map_i = self.binding_mode_map(&p);
2170 for (j, q) in arm.pats.iter().enumerate() {
2175 let map_j = self.binding_mode_map(&q);
2176 for (&key, &binding_i) in &map_i {
2177 if map_j.len() == 0 { // Account for missing bindings when
2178 let binding_error = missing_vars // map_j has none.
2180 .or_insert(BindingError {
2182 origin: BTreeSet::new(),
2183 target: BTreeSet::new(),
2185 binding_error.origin.insert(binding_i.span);
2186 binding_error.target.insert(q.span);
2188 for (&key_j, &binding_j) in &map_j {
2189 match map_i.get(&key_j) {
2190 None => { // missing binding
2191 let binding_error = missing_vars
2193 .or_insert(BindingError {
2195 origin: BTreeSet::new(),
2196 target: BTreeSet::new(),
2198 binding_error.origin.insert(binding_j.span);
2199 binding_error.target.insert(p.span);
2201 Some(binding_i) => { // check consistent binding
2202 if binding_i.binding_mode != binding_j.binding_mode {
2205 .or_insert((binding_j.span, binding_i.span));
2213 let mut missing_vars = missing_vars.iter().collect::<Vec<_>>();
2214 missing_vars.sort();
2215 for (_, v) in missing_vars {
2217 *v.origin.iter().next().unwrap(),
2218 ResolutionError::VariableNotBoundInPattern(v));
2220 let mut inconsistent_vars = inconsistent_vars.iter().collect::<Vec<_>>();
2221 inconsistent_vars.sort();
2222 for (name, v) in inconsistent_vars {
2223 resolve_error(self, v.0, ResolutionError::VariableBoundWithDifferentMode(*name, v.1));
2227 fn resolve_arm(&mut self, arm: &Arm) {
2228 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2230 let mut bindings_list = FxHashMap();
2231 for pattern in &arm.pats {
2232 self.resolve_pattern(&pattern, PatternSource::Match, &mut bindings_list);
2235 // This has to happen *after* we determine which
2236 // pat_idents are variants
2237 self.check_consistent_bindings(arm);
2239 walk_list!(self, visit_expr, &arm.guard);
2240 self.visit_expr(&arm.body);
2242 self.ribs[ValueNS].pop();
2245 fn resolve_block(&mut self, block: &Block) {
2246 debug!("(resolving block) entering block");
2247 // Move down in the graph, if there's an anonymous module rooted here.
2248 let orig_module = self.current_module;
2249 let anonymous_module = self.block_map.get(&block.id).cloned(); // clones a reference
2251 let mut num_macro_definition_ribs = 0;
2252 if let Some(anonymous_module) = anonymous_module {
2253 debug!("(resolving block) found anonymous module, moving down");
2254 self.ribs[ValueNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2255 self.ribs[TypeNS].push(Rib::new(ModuleRibKind(anonymous_module)));
2256 self.current_module = anonymous_module;
2257 self.finalize_current_module_macro_resolutions();
2259 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
2262 // Descend into the block.
2263 for stmt in &block.stmts {
2264 if let ast::StmtKind::Item(ref item) = stmt.node {
2265 if let ast::ItemKind::MacroDef(..) = item.node {
2266 num_macro_definition_ribs += 1;
2267 let def = self.definitions.local_def_id(item.id);
2268 self.ribs[ValueNS].push(Rib::new(MacroDefinition(def)));
2269 self.label_ribs.push(Rib::new(MacroDefinition(def)));
2273 self.visit_stmt(stmt);
2277 self.current_module = orig_module;
2278 for _ in 0 .. num_macro_definition_ribs {
2279 self.ribs[ValueNS].pop();
2280 self.label_ribs.pop();
2282 self.ribs[ValueNS].pop();
2283 if let Some(_) = anonymous_module {
2284 self.ribs[TypeNS].pop();
2286 debug!("(resolving block) leaving block");
2289 fn fresh_binding(&mut self,
2290 ident: &SpannedIdent,
2292 outer_pat_id: NodeId,
2293 pat_src: PatternSource,
2294 bindings: &mut FxHashMap<Ident, NodeId>)
2296 // Add the binding to the local ribs, if it
2297 // doesn't already exist in the bindings map. (We
2298 // must not add it if it's in the bindings map
2299 // because that breaks the assumptions later
2300 // passes make about or-patterns.)
2301 let mut def = Def::Local(self.definitions.local_def_id(pat_id));
2302 match bindings.get(&ident.node).cloned() {
2303 Some(id) if id == outer_pat_id => {
2304 // `Variant(a, a)`, error
2308 ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
2309 &ident.node.name.as_str())
2312 Some(..) if pat_src == PatternSource::FnParam => {
2313 // `fn f(a: u8, a: u8)`, error
2317 ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
2318 &ident.node.name.as_str())
2321 Some(..) if pat_src == PatternSource::Match => {
2322 // `Variant1(a) | Variant2(a)`, ok
2323 // Reuse definition from the first `a`.
2324 def = self.ribs[ValueNS].last_mut().unwrap().bindings[&ident.node];
2327 span_bug!(ident.span, "two bindings with the same name from \
2328 unexpected pattern source {:?}", pat_src);
2331 // A completely fresh binding, add to the lists if it's valid.
2332 if ident.node.name != keywords::Invalid.name() {
2333 bindings.insert(ident.node, outer_pat_id);
2334 self.ribs[ValueNS].last_mut().unwrap().bindings.insert(ident.node, def);
2339 PathResolution::new(def)
2342 fn resolve_pattern(&mut self,
2344 pat_src: PatternSource,
2345 // Maps idents to the node ID for the
2346 // outermost pattern that binds them.
2347 bindings: &mut FxHashMap<Ident, NodeId>) {
2348 // Visit all direct subpatterns of this pattern.
2349 let outer_pat_id = pat.id;
2350 pat.walk(&mut |pat| {
2352 PatKind::Ident(bmode, ref ident, ref opt_pat) => {
2353 // First try to resolve the identifier as some existing
2354 // entity, then fall back to a fresh binding.
2355 let binding = self.resolve_ident_in_lexical_scope(ident.node, ValueNS,
2357 .and_then(LexicalScopeBinding::item);
2358 let resolution = binding.map(NameBinding::def).and_then(|def| {
2359 let ivmode = BindingMode::ByValue(Mutability::Immutable);
2360 let always_binding = !pat_src.is_refutable() || opt_pat.is_some() ||
2363 Def::StructCtor(_, CtorKind::Const) |
2364 Def::VariantCtor(_, CtorKind::Const) |
2365 Def::Const(..) if !always_binding => {
2366 // A unit struct/variant or constant pattern.
2367 self.record_use(ident.node, ValueNS, binding.unwrap(), ident.span);
2368 Some(PathResolution::new(def))
2370 Def::StructCtor(..) | Def::VariantCtor(..) |
2371 Def::Const(..) | Def::Static(..) => {
2372 // A fresh binding that shadows something unacceptable.
2376 ResolutionError::BindingShadowsSomethingUnacceptable(
2377 pat_src.descr(), ident.node.name, binding.unwrap())
2381 Def::Local(..) | Def::Upvar(..) | Def::Fn(..) | Def::Err => {
2382 // These entities are explicitly allowed
2383 // to be shadowed by fresh bindings.
2387 span_bug!(ident.span, "unexpected definition for an \
2388 identifier in pattern: {:?}", def);
2391 }).unwrap_or_else(|| {
2392 self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings)
2395 self.record_def(pat.id, resolution);
2398 PatKind::TupleStruct(ref path, ..) => {
2399 self.smart_resolve_path(pat.id, None, path, PathSource::TupleStruct);
2402 PatKind::Path(ref qself, ref path) => {
2403 self.smart_resolve_path(pat.id, qself.as_ref(), path, PathSource::Pat);
2406 PatKind::Struct(ref path, ..) => {
2407 self.smart_resolve_path(pat.id, None, path, PathSource::Struct);
2415 visit::walk_pat(self, pat);
2418 // High-level and context dependent path resolution routine.
2419 // Resolves the path and records the resolution into definition map.
2420 // If resolution fails tries several techniques to find likely
2421 // resolution candidates, suggest imports or other help, and report
2422 // errors in user friendly way.
2423 fn smart_resolve_path(&mut self,
2425 qself: Option<&QSelf>,
2429 let segments = &path.segments.iter()
2430 .map(|seg| respan(seg.span, seg.identifier))
2431 .collect::<Vec<_>>();
2432 let ident_span = path.segments.last().map_or(path.span, |seg| seg.span);
2433 self.smart_resolve_path_fragment(id, qself, segments, path.span, ident_span, source)
2436 fn smart_resolve_path_fragment(&mut self,
2438 qself: Option<&QSelf>,
2439 path: &[SpannedIdent],
2444 let ns = source.namespace();
2445 let is_expected = &|def| source.is_expected(def);
2446 let is_enum_variant = &|def| if let Def::Variant(..) = def { true } else { false };
2448 // Base error is amended with one short label and possibly some longer helps/notes.
2449 let report_errors = |this: &mut Self, def: Option<Def>| {
2450 // Make the base error.
2451 let expected = source.descr_expected();
2452 let path_str = names_to_string(path);
2453 let code = source.error_code(def.is_some());
2454 let (base_msg, fallback_label, base_span) = if let Some(def) = def {
2455 (format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str),
2456 format!("not a {}", expected), span)
2458 let item_str = path[path.len() - 1].node;
2459 let item_span = path[path.len() - 1].span;
2460 let (mod_prefix, mod_str) = if path.len() == 1 {
2461 (format!(""), format!("this scope"))
2462 } else if path.len() == 2 && path[0].node.name == keywords::CrateRoot.name() {
2463 (format!(""), format!("the crate root"))
2465 let mod_path = &path[..path.len() - 1];
2466 let mod_prefix = match this.resolve_path(mod_path, Some(TypeNS), false, span) {
2467 PathResult::Module(module) => module.def(),
2469 }.map_or(format!(""), |def| format!("{} ", def.kind_name()));
2470 (mod_prefix, format!("`{}`", names_to_string(mod_path)))
2472 (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str),
2473 format!("not found in {}", mod_str), item_span)
2475 let mut err = this.session.struct_span_err_with_code(base_span, &base_msg, code);
2477 // Emit special messages for unresolved `Self` and `self`.
2478 if is_self_type(path, ns) {
2479 __diagnostic_used!(E0411);
2480 err.code("E0411".into());
2481 err.span_label(span, "`Self` is only available in traits and impls");
2482 return (err, Vec::new());
2484 if is_self_value(path, ns) {
2485 __diagnostic_used!(E0424);
2486 err.code("E0424".into());
2487 err.span_label(span, format!("`self` value is only available in \
2488 methods with `self` parameter"));
2489 return (err, Vec::new());
2492 // Try to lookup the name in more relaxed fashion for better error reporting.
2493 let ident = *path.last().unwrap();
2494 let candidates = this.lookup_import_candidates(ident.node.name, ns, is_expected);
2495 if candidates.is_empty() && is_expected(Def::Enum(DefId::local(CRATE_DEF_INDEX))) {
2496 let enum_candidates =
2497 this.lookup_import_candidates(ident.node.name, ns, is_enum_variant);
2498 let mut enum_candidates = enum_candidates.iter()
2499 .map(|suggestion| import_candidate_to_paths(&suggestion)).collect::<Vec<_>>();
2500 enum_candidates.sort();
2501 for (sp, variant_path, enum_path) in enum_candidates {
2503 let msg = format!("there is an enum variant `{}`, \
2509 err.span_suggestion(span, "you can try using the variant's enum",
2514 if path.len() == 1 && this.self_type_is_available(span) {
2515 if let Some(candidate) = this.lookup_assoc_candidate(ident.node, ns, is_expected) {
2516 let self_is_available = this.self_value_is_available(path[0].node.ctxt, span);
2518 AssocSuggestion::Field => {
2519 err.span_suggestion(span, "try",
2520 format!("self.{}", path_str));
2521 if !self_is_available {
2522 err.span_label(span, format!("`self` value is only available in \
2523 methods with `self` parameter"));
2526 AssocSuggestion::MethodWithSelf if self_is_available => {
2527 err.span_suggestion(span, "try",
2528 format!("self.{}", path_str));
2530 AssocSuggestion::MethodWithSelf | AssocSuggestion::AssocItem => {
2531 err.span_suggestion(span, "try",
2532 format!("Self::{}", path_str));
2535 return (err, candidates);
2539 let mut levenshtein_worked = false;
2542 if let Some(candidate) = this.lookup_typo_candidate(path, ns, is_expected, span) {
2543 err.span_label(ident_span, format!("did you mean `{}`?", candidate));
2544 levenshtein_worked = true;
2547 // Try context dependent help if relaxed lookup didn't work.
2548 if let Some(def) = def {
2549 match (def, source) {
2550 (Def::Macro(..), _) => {
2551 err.span_label(span, format!("did you mean `{}!(...)`?", path_str));
2552 return (err, candidates);
2554 (Def::TyAlias(..), PathSource::Trait) => {
2555 err.span_label(span, "type aliases cannot be used for traits");
2556 return (err, candidates);
2558 (Def::Mod(..), PathSource::Expr(Some(parent))) => match parent.node {
2559 ExprKind::Field(_, ident) => {
2560 err.span_label(parent.span, format!("did you mean `{}::{}`?",
2561 path_str, ident.node));
2562 return (err, candidates);
2564 ExprKind::MethodCall(ref segment, ..) => {
2565 err.span_label(parent.span, format!("did you mean `{}::{}(...)`?",
2566 path_str, segment.identifier));
2567 return (err, candidates);
2571 _ if ns == ValueNS && is_struct_like(def) => {
2572 if let Def::Struct(def_id) = def {
2573 if let Some((ctor_def, ctor_vis))
2574 = this.struct_constructors.get(&def_id).cloned() {
2575 if is_expected(ctor_def) && !this.is_accessible(ctor_vis) {
2576 err.span_label(span, format!("constructor is not visible \
2577 here due to private fields"));
2581 err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?",
2583 return (err, candidates);
2590 if !levenshtein_worked {
2591 err.span_label(base_span, fallback_label);
2592 this.type_ascription_suggestion(&mut err, base_span);
2596 let report_errors = |this: &mut Self, def: Option<Def>| {
2597 let (err, candidates) = report_errors(this, def);
2598 let def_id = this.current_module.normal_ancestor_id;
2599 let node_id = this.definitions.as_local_node_id(def_id).unwrap();
2600 let better = def.is_some();
2601 this.use_injections.push(UseError { err, candidates, node_id, better });
2602 err_path_resolution()
2605 let resolution = match self.resolve_qpath_anywhere(id, qself, path, ns, span,
2606 source.defer_to_typeck(),
2607 source.global_by_default()) {
2608 Some(resolution) if resolution.unresolved_segments() == 0 => {
2609 if is_expected(resolution.base_def()) || resolution.base_def() == Def::Err {
2612 // Add a temporary hack to smooth the transition to new struct ctor
2613 // visibility rules. See #38932 for more details.
2615 if let Def::Struct(def_id) = resolution.base_def() {
2616 if let Some((ctor_def, ctor_vis))
2617 = self.struct_constructors.get(&def_id).cloned() {
2618 if is_expected(ctor_def) && self.is_accessible(ctor_vis) {
2619 let lint = lint::builtin::LEGACY_CONSTRUCTOR_VISIBILITY;
2620 self.session.buffer_lint(lint, id, span,
2621 "private struct constructors are not usable through \
2622 reexports in outer modules",
2624 res = Some(PathResolution::new(ctor_def));
2629 res.unwrap_or_else(|| report_errors(self, Some(resolution.base_def())))
2632 Some(resolution) if source.defer_to_typeck() => {
2633 // Not fully resolved associated item `T::A::B` or `<T as Tr>::A::B`
2634 // or `<T>::A::B`. If `B` should be resolved in value namespace then
2635 // it needs to be added to the trait map.
2637 let item_name = path.last().unwrap().node;
2638 let traits = self.get_traits_containing_item(item_name, ns);
2639 self.trait_map.insert(id, traits);
2643 _ => report_errors(self, None)
2646 if let PathSource::TraitItem(..) = source {} else {
2647 // Avoid recording definition of `A::B` in `<T as A>::B::C`.
2648 self.record_def(id, resolution);
2653 fn type_ascription_suggestion(&self,
2654 err: &mut DiagnosticBuilder,
2656 debug!("type_ascription_suggetion {:?}", base_span);
2657 let cm = self.session.codemap();
2658 debug!("self.current_type_ascription {:?}", self.current_type_ascription);
2659 if let Some(sp) = self.current_type_ascription.last() {
2661 loop { // try to find the `:`, bail on first non-':'/non-whitespace
2662 sp = sp.next_point();
2663 if let Ok(snippet) = cm.span_to_snippet(sp.to(sp.next_point())) {
2664 debug!("snippet {:?}", snippet);
2665 let line_sp = cm.lookup_char_pos(sp.hi).line;
2666 let line_base_sp = cm.lookup_char_pos(base_span.lo).line;
2667 debug!("{:?} {:?}", line_sp, line_base_sp);
2669 err.span_label(base_span,
2670 "expecting a type here because of type ascription");
2671 if line_sp != line_base_sp {
2672 err.span_suggestion_short(sp,
2673 "did you mean to use `;` here instead?",
2677 } else if snippet.trim().len() != 0 {
2678 debug!("tried to find type ascription `:` token, couldn't find it");
2688 fn self_type_is_available(&mut self, span: Span) -> bool {
2689 let binding = self.resolve_ident_in_lexical_scope(keywords::SelfType.ident(),
2690 TypeNS, false, span);
2691 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
2694 fn self_value_is_available(&mut self, ctxt: SyntaxContext, span: Span) -> bool {
2695 let ident = Ident { name: keywords::SelfValue.name(), ctxt: ctxt };
2696 let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, false, span);
2697 if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false }
2700 // Resolve in alternative namespaces if resolution in the primary namespace fails.
2701 fn resolve_qpath_anywhere(&mut self,
2703 qself: Option<&QSelf>,
2704 path: &[SpannedIdent],
2705 primary_ns: Namespace,
2707 defer_to_typeck: bool,
2708 global_by_default: bool)
2709 -> Option<PathResolution> {
2710 let mut fin_res = None;
2711 // FIXME: can't resolve paths in macro namespace yet, macros are
2712 // processed by the little special hack below.
2713 for (i, ns) in [primary_ns, TypeNS, ValueNS, /*MacroNS*/].iter().cloned().enumerate() {
2714 if i == 0 || ns != primary_ns {
2715 match self.resolve_qpath(id, qself, path, ns, span, global_by_default) {
2716 // If defer_to_typeck, then resolution > no resolution,
2717 // otherwise full resolution > partial resolution > no resolution.
2718 Some(res) if res.unresolved_segments() == 0 || defer_to_typeck =>
2720 res => if fin_res.is_none() { fin_res = res },
2724 let is_global = self.global_macros.get(&path[0].node.name).cloned()
2725 .map(|binding| binding.get_macro(self).kind() == MacroKind::Bang).unwrap_or(false);
2726 if primary_ns != MacroNS && (is_global ||
2727 self.macro_names.contains(&path[0].node.modern())) {
2728 // Return some dummy definition, it's enough for error reporting.
2730 PathResolution::new(Def::Macro(DefId::local(CRATE_DEF_INDEX), MacroKind::Bang))
2736 /// Handles paths that may refer to associated items.
2737 fn resolve_qpath(&mut self,
2739 qself: Option<&QSelf>,
2740 path: &[SpannedIdent],
2743 global_by_default: bool)
2744 -> Option<PathResolution> {
2745 if let Some(qself) = qself {
2746 if qself.position == 0 {
2747 // FIXME: Create some fake resolution that can't possibly be a type.
2748 return Some(PathResolution::with_unresolved_segments(
2749 Def::Mod(DefId::local(CRATE_DEF_INDEX)), path.len()
2752 // Make sure `A::B` in `<T as A>::B::C` is a trait item.
2753 let ns = if qself.position + 1 == path.len() { ns } else { TypeNS };
2754 let res = self.smart_resolve_path_fragment(id, None, &path[..qself.position + 1],
2755 span, span, PathSource::TraitItem(ns));
2756 return Some(PathResolution::with_unresolved_segments(
2757 res.base_def(), res.unresolved_segments() + path.len() - qself.position - 1
2761 let result = match self.resolve_path(&path, Some(ns), true, span) {
2762 PathResult::NonModule(path_res) => path_res,
2763 PathResult::Module(module) if !module.is_normal() => {
2764 PathResolution::new(module.def().unwrap())
2766 // In `a(::assoc_item)*` `a` cannot be a module. If `a` does resolve to a module we
2767 // don't report an error right away, but try to fallback to a primitive type.
2768 // So, we are still able to successfully resolve something like
2770 // use std::u8; // bring module u8 in scope
2771 // fn f() -> u8 { // OK, resolves to primitive u8, not to std::u8
2772 // u8::max_value() // OK, resolves to associated function <u8>::max_value,
2773 // // not to non-existent std::u8::max_value
2776 // Such behavior is required for backward compatibility.
2777 // The same fallback is used when `a` resolves to nothing.
2778 PathResult::Module(..) | PathResult::Failed(..)
2779 if (ns == TypeNS || path.len() > 1) &&
2780 self.primitive_type_table.primitive_types
2781 .contains_key(&path[0].node.name) => {
2782 let prim = self.primitive_type_table.primitive_types[&path[0].node.name];
2784 TyUint(UintTy::U128) | TyInt(IntTy::I128) => {
2785 if !self.session.features.borrow().i128_type {
2786 emit_feature_err(&self.session.parse_sess,
2787 "i128_type", span, GateIssue::Language,
2788 "128-bit type is unstable");
2794 PathResolution::with_unresolved_segments(Def::PrimTy(prim), path.len() - 1)
2796 PathResult::Module(module) => PathResolution::new(module.def().unwrap()),
2797 PathResult::Failed(span, msg, false) => {
2798 resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
2799 err_path_resolution()
2801 PathResult::Failed(..) => return None,
2802 PathResult::Indeterminate => bug!("indetermined path result in resolve_qpath"),
2805 if path.len() > 1 && !global_by_default && result.base_def() != Def::Err &&
2806 path[0].node.name != keywords::CrateRoot.name() &&
2807 path[0].node.name != keywords::DollarCrate.name() {
2808 let unqualified_result = {
2809 match self.resolve_path(&[*path.last().unwrap()], Some(ns), false, span) {
2810 PathResult::NonModule(path_res) => path_res.base_def(),
2811 PathResult::Module(module) => module.def().unwrap(),
2812 _ => return Some(result),
2815 if result.base_def() == unqualified_result {
2816 let lint = lint::builtin::UNUSED_QUALIFICATIONS;
2817 self.session.buffer_lint(lint, id, span, "unnecessary qualification")
2824 fn resolve_path(&mut self,
2825 path: &[SpannedIdent],
2826 opt_ns: Option<Namespace>, // `None` indicates a module path
2830 let mut module = None;
2831 let mut allow_super = true;
2833 for (i, &ident) in path.iter().enumerate() {
2834 debug!("resolve_path ident {} {:?}", i, ident);
2835 let is_last = i == path.len() - 1;
2836 let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
2838 if i == 0 && ns == TypeNS && ident.node.name == keywords::SelfValue.name() {
2839 let mut ctxt = ident.node.ctxt.modern();
2840 module = Some(self.resolve_self(&mut ctxt, self.current_module));
2842 } else if allow_super && ns == TypeNS && ident.node.name == keywords::Super.name() {
2843 let mut ctxt = ident.node.ctxt.modern();
2844 let self_module = match i {
2845 0 => self.resolve_self(&mut ctxt, self.current_module),
2846 _ => module.unwrap(),
2848 if let Some(parent) = self_module.parent {
2849 module = Some(self.resolve_self(&mut ctxt, parent));
2852 let msg = "There are too many initial `super`s.".to_string();
2853 return PathResult::Failed(ident.span, msg, false);
2856 allow_super = false;
2858 if i == 0 && ns == TypeNS && ident.node.name == keywords::CrateRoot.name() {
2859 module = Some(self.resolve_crate_root(ident.node.ctxt.modern()));
2861 } else if i == 0 && ns == TypeNS && ident.node.name == keywords::DollarCrate.name() {
2862 module = Some(self.resolve_crate_root(ident.node.ctxt));
2866 let binding = if let Some(module) = module {
2867 self.resolve_ident_in_module(module, ident.node, ns, false, record_used, path_span)
2868 } else if opt_ns == Some(MacroNS) {
2869 self.resolve_lexical_macro_path_segment(ident.node, ns, record_used, path_span)
2870 .map(MacroBinding::binding)
2872 match self.resolve_ident_in_lexical_scope(ident.node, ns, record_used, path_span) {
2873 Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
2874 Some(LexicalScopeBinding::Def(def))
2875 if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) => {
2876 return PathResult::NonModule(PathResolution::with_unresolved_segments(
2880 _ => Err(if record_used { Determined } else { Undetermined }),
2886 let def = binding.def();
2887 let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(def);
2888 if let Some(next_module) = binding.module() {
2889 module = Some(next_module);
2890 } else if def == Def::Err {
2891 return PathResult::NonModule(err_path_resolution());
2892 } else if opt_ns.is_some() && (is_last || maybe_assoc) {
2893 return PathResult::NonModule(PathResolution::with_unresolved_segments(
2894 def, path.len() - i - 1
2897 return PathResult::Failed(ident.span,
2898 format!("Not a module `{}`", ident.node),
2902 Err(Undetermined) => return PathResult::Indeterminate,
2903 Err(Determined) => {
2904 if let Some(module) = module {
2905 if opt_ns.is_some() && !module.is_normal() {
2906 return PathResult::NonModule(PathResolution::with_unresolved_segments(
2907 module.def().unwrap(), path.len() - i
2911 let msg = if module.and_then(ModuleData::def) == self.graph_root.def() {
2912 let is_mod = |def| match def { Def::Mod(..) => true, _ => false };
2913 let mut candidates =
2914 self.lookup_import_candidates(ident.node.name, TypeNS, is_mod);
2915 candidates.sort_by_key(|c| (c.path.segments.len(), c.path.to_string()));
2916 if let Some(candidate) = candidates.get(0) {
2917 format!("Did you mean `{}`?", candidate.path)
2919 format!("Maybe a missing `extern crate {};`?", ident.node)
2922 format!("Use of undeclared type or module `{}`", ident.node)
2924 format!("Could not find `{}` in `{}`", ident.node, path[i - 1].node)
2926 return PathResult::Failed(ident.span, msg, is_last);
2931 PathResult::Module(module.unwrap_or(self.graph_root))
2934 // Resolve a local definition, potentially adjusting for closures.
2935 fn adjust_local_def(&mut self,
2940 span: Span) -> Def {
2941 let ribs = &self.ribs[ns][rib_index + 1..];
2943 // An invalid forward use of a type parameter from a previous default.
2944 if let ForwardTyParamBanRibKind = self.ribs[ns][rib_index].kind {
2946 resolve_error(self, span, ResolutionError::ForwardDeclaredTyParam);
2948 assert_eq!(def, Def::Err);
2954 span_bug!(span, "unexpected {:?} in bindings", def)
2956 Def::Local(def_id) => {
2959 NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) |
2960 ForwardTyParamBanRibKind => {
2961 // Nothing to do. Continue.
2963 ClosureRibKind(function_id) => {
2965 let node_id = self.definitions.as_local_node_id(def_id).unwrap();
2967 let seen = self.freevars_seen
2969 .or_insert_with(|| NodeMap());
2970 if let Some(&index) = seen.get(&node_id) {
2971 def = Def::Upvar(def_id, index, function_id);
2974 let vec = self.freevars
2976 .or_insert_with(|| vec![]);
2977 let depth = vec.len();
2978 def = Def::Upvar(def_id, depth, function_id);
2985 seen.insert(node_id, depth);
2988 ItemRibKind | MethodRibKind(_) => {
2989 // This was an attempt to access an upvar inside a
2990 // named function item. This is not allowed, so we
2993 resolve_error(self, span,
2994 ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
2998 ConstantItemRibKind => {
2999 // Still doesn't deal with upvars
3001 resolve_error(self, span,
3002 ResolutionError::AttemptToUseNonConstantValueInConstant);
3009 Def::TyParam(..) | Def::SelfTy(..) => {
3012 NormalRibKind | MethodRibKind(_) | ClosureRibKind(..) |
3013 ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind |
3014 ConstantItemRibKind => {
3015 // Nothing to do. Continue.
3018 // This was an attempt to use a type parameter outside
3021 resolve_error(self, span,
3022 ResolutionError::TypeParametersFromOuterFunction);
3034 // Calls `f` with a `Resolver` whose current lexical scope is `module`'s lexical scope,
3035 // i.e. the module's items and the prelude (unless the module is `#[no_implicit_prelude]`).
3036 // FIXME #34673: This needs testing.
3037 pub fn with_module_lexical_scope<T, F>(&mut self, module: Module<'a>, f: F) -> T
3038 where F: FnOnce(&mut Resolver<'a>) -> T,
3040 self.with_empty_ribs(|this| {
3041 this.ribs[ValueNS].push(Rib::new(ModuleRibKind(module)));
3042 this.ribs[TypeNS].push(Rib::new(ModuleRibKind(module)));
3047 fn with_empty_ribs<T, F>(&mut self, f: F) -> T
3048 where F: FnOnce(&mut Resolver<'a>) -> T,
3050 let ribs = replace(&mut self.ribs, PerNS::<Vec<Rib>>::default());
3051 let label_ribs = replace(&mut self.label_ribs, Vec::new());
3053 let result = f(self);
3055 self.label_ribs = label_ribs;
3059 fn lookup_assoc_candidate<FilterFn>(&mut self,
3062 filter_fn: FilterFn)
3063 -> Option<AssocSuggestion>
3064 where FilterFn: Fn(Def) -> bool
3066 fn extract_node_id(t: &Ty) -> Option<NodeId> {
3068 TyKind::Path(None, _) => Some(t.id),
3069 TyKind::Rptr(_, ref mut_ty) => extract_node_id(&mut_ty.ty),
3070 // This doesn't handle the remaining `Ty` variants as they are not
3071 // that commonly the self_type, it might be interesting to provide
3072 // support for those in future.
3077 // Fields are generally expected in the same contexts as locals.
3078 if filter_fn(Def::Local(DefId::local(CRATE_DEF_INDEX))) {
3079 if let Some(node_id) = self.current_self_type.as_ref().and_then(extract_node_id) {
3080 // Look for a field with the same name in the current self_type.
3081 if let Some(resolution) = self.def_map.get(&node_id) {
3082 match resolution.base_def() {
3083 Def::Struct(did) | Def::Union(did)
3084 if resolution.unresolved_segments() == 0 => {
3085 if let Some(field_names) = self.field_names.get(&did) {
3086 if field_names.iter().any(|&field_name| ident.name == field_name) {
3087 return Some(AssocSuggestion::Field);
3097 // Look for associated items in the current trait.
3098 if let Some((module, _)) = self.current_trait_ref {
3099 if let Ok(binding) =
3100 self.resolve_ident_in_module(module, ident, ns, false, false, module.span) {
3101 let def = binding.def();
3103 return Some(if self.has_self.contains(&def.def_id()) {
3104 AssocSuggestion::MethodWithSelf
3106 AssocSuggestion::AssocItem
3115 fn lookup_typo_candidate<FilterFn>(&mut self,
3116 path: &[SpannedIdent],
3118 filter_fn: FilterFn,
3121 where FilterFn: Fn(Def) -> bool
3123 let add_module_candidates = |module: Module, names: &mut Vec<Name>| {
3124 for (&(ident, _), resolution) in module.resolutions.borrow().iter() {
3125 if let Some(binding) = resolution.borrow().binding {
3126 if filter_fn(binding.def()) {
3127 names.push(ident.name);
3133 let mut names = Vec::new();
3134 if path.len() == 1 {
3135 // Search in lexical scope.
3136 // Walk backwards up the ribs in scope and collect candidates.
3137 for rib in self.ribs[ns].iter().rev() {
3138 // Locals and type parameters
3139 for (ident, def) in &rib.bindings {
3140 if filter_fn(*def) {
3141 names.push(ident.name);
3145 if let ModuleRibKind(module) = rib.kind {
3146 // Items from this module
3147 add_module_candidates(module, &mut names);
3149 if let ModuleKind::Block(..) = module.kind {
3150 // We can see through blocks
3152 // Items from the prelude
3153 if let Some(prelude) = self.prelude {
3154 if !module.no_implicit_prelude {
3155 add_module_candidates(prelude, &mut names);
3162 // Add primitive types to the mix
3163 if filter_fn(Def::PrimTy(TyBool)) {
3164 for (name, _) in &self.primitive_type_table.primitive_types {
3169 // Search in module.
3170 let mod_path = &path[..path.len() - 1];
3171 if let PathResult::Module(module) = self.resolve_path(mod_path, Some(TypeNS),
3173 add_module_candidates(module, &mut names);
3177 let name = path[path.len() - 1].node.name;
3178 // Make sure error reporting is deterministic.
3179 names.sort_by_key(|name| name.as_str());
3180 match find_best_match_for_name(names.iter(), &name.as_str(), None) {
3181 Some(found) if found != name => Some(found),
3186 fn with_resolved_label<F>(&mut self, label: Option<SpannedIdent>, id: NodeId, f: F)
3187 where F: FnOnce(&mut Resolver)
3189 if let Some(label) = label {
3190 let def = Def::Label(id);
3191 self.with_label_rib(|this| {
3192 this.label_ribs.last_mut().unwrap().bindings.insert(label.node, def);
3200 fn resolve_labeled_block(&mut self, label: Option<SpannedIdent>, id: NodeId, block: &Block) {
3201 self.with_resolved_label(label, id, |this| this.visit_block(block));
3204 fn resolve_expr(&mut self, expr: &Expr, parent: Option<&Expr>) {
3205 // First, record candidate traits for this expression if it could
3206 // result in the invocation of a method call.
3208 self.record_candidate_traits_for_expr_if_necessary(expr);
3210 // Next, resolve the node.
3212 ExprKind::Path(ref qself, ref path) => {
3213 self.smart_resolve_path(expr.id, qself.as_ref(), path, PathSource::Expr(parent));
3214 visit::walk_expr(self, expr);
3217 ExprKind::Struct(ref path, ..) => {
3218 self.smart_resolve_path(expr.id, None, path, PathSource::Struct);
3219 visit::walk_expr(self, expr);
3222 ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => {
3223 match self.search_label(label.node) {
3225 self.record_def(expr.id, err_path_resolution());
3228 ResolutionError::UndeclaredLabel(&label.node.name.as_str()));
3230 Some(def @ Def::Label(_)) => {
3231 // Since this def is a label, it is never read.
3232 self.record_def(expr.id, PathResolution::new(def));
3235 span_bug!(expr.span, "label wasn't mapped to a label def!");
3239 // visit `break` argument if any
3240 visit::walk_expr(self, expr);
3243 ExprKind::IfLet(ref pattern, ref subexpression, ref if_block, ref optional_else) => {
3244 self.visit_expr(subexpression);
3246 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
3247 self.resolve_pattern(pattern, PatternSource::IfLet, &mut FxHashMap());
3248 self.visit_block(if_block);
3249 self.ribs[ValueNS].pop();
3251 optional_else.as_ref().map(|expr| self.visit_expr(expr));
3254 ExprKind::Loop(ref block, label) => self.resolve_labeled_block(label, expr.id, &block),
3256 ExprKind::While(ref subexpression, ref block, label) => {
3257 self.with_resolved_label(label, expr.id, |this| {
3258 this.visit_expr(subexpression);
3259 this.visit_block(block);
3263 ExprKind::WhileLet(ref pattern, ref subexpression, ref block, label) => {
3264 self.with_resolved_label(label, expr.id, |this| {
3265 this.visit_expr(subexpression);
3266 this.ribs[ValueNS].push(Rib::new(NormalRibKind));
3267 this.resolve_pattern(pattern, PatternSource::WhileLet, &mut FxHashMap());
3268 this.visit_block(block);
3269 this.ribs[ValueNS].pop();
3273 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, label) => {
3274 self.visit_expr(subexpression);
3275 self.ribs[ValueNS].push(Rib::new(NormalRibKind));
3276 self.resolve_pattern(pattern, PatternSource::For, &mut FxHashMap());
3278 self.resolve_labeled_block(label, expr.id, block);
3280 self.ribs[ValueNS].pop();
3283 // Equivalent to `visit::walk_expr` + passing some context to children.
3284 ExprKind::Field(ref subexpression, _) => {
3285 self.resolve_expr(subexpression, Some(expr));
3287 ExprKind::MethodCall(ref segment, ref arguments) => {
3288 let mut arguments = arguments.iter();
3289 self.resolve_expr(arguments.next().unwrap(), Some(expr));
3290 for argument in arguments {
3291 self.resolve_expr(argument, None);
3293 self.visit_path_segment(expr.span, segment);
3296 ExprKind::Repeat(ref element, ref count) => {
3297 self.visit_expr(element);
3298 self.with_constant_rib(|this| {
3299 this.visit_expr(count);
3302 ExprKind::Call(ref callee, ref arguments) => {
3303 self.resolve_expr(callee, Some(expr));
3304 for argument in arguments {
3305 self.resolve_expr(argument, None);
3308 ExprKind::Type(ref type_expr, _) => {
3309 self.current_type_ascription.push(type_expr.span);
3310 visit::walk_expr(self, expr);
3311 self.current_type_ascription.pop();
3314 visit::walk_expr(self, expr);
3319 fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
3321 ExprKind::Field(_, name) => {
3322 // FIXME(#6890): Even though you can't treat a method like a
3323 // field, we need to add any trait methods we find that match
3324 // the field name so that we can do some nice error reporting
3325 // later on in typeck.
3326 let traits = self.get_traits_containing_item(name.node, ValueNS);
3327 self.trait_map.insert(expr.id, traits);
3329 ExprKind::MethodCall(ref segment, ..) => {
3330 debug!("(recording candidate traits for expr) recording traits for {}",
3332 let traits = self.get_traits_containing_item(segment.identifier, ValueNS);
3333 self.trait_map.insert(expr.id, traits);
3341 fn get_traits_containing_item(&mut self, mut ident: Ident, ns: Namespace)
3342 -> Vec<TraitCandidate> {
3343 debug!("(getting traits containing item) looking for '{}'", ident.name);
3345 let mut found_traits = Vec::new();
3346 // Look for the current trait.
3347 if let Some((module, _)) = self.current_trait_ref {
3348 if self.resolve_ident_in_module(module, ident, ns, false, false, module.span).is_ok() {
3349 let def_id = module.def_id().unwrap();
3350 found_traits.push(TraitCandidate { def_id: def_id, import_id: None });
3354 ident.ctxt = ident.ctxt.modern();
3355 let mut search_module = self.current_module;
3357 self.get_traits_in_module_containing_item(ident, ns, search_module, &mut found_traits);
3359 unwrap_or!(self.hygienic_lexical_parent(search_module, &mut ident.ctxt), break);
3362 if let Some(prelude) = self.prelude {
3363 if !search_module.no_implicit_prelude {
3364 self.get_traits_in_module_containing_item(ident, ns, prelude, &mut found_traits);
3371 fn get_traits_in_module_containing_item(&mut self,
3375 found_traits: &mut Vec<TraitCandidate>) {
3376 let mut traits = module.traits.borrow_mut();
3377 if traits.is_none() {
3378 let mut collected_traits = Vec::new();
3379 module.for_each_child(|name, ns, binding| {
3380 if ns != TypeNS { return }
3381 if let Def::Trait(_) = binding.def() {
3382 collected_traits.push((name, binding));
3385 *traits = Some(collected_traits.into_boxed_slice());
3388 for &(trait_name, binding) in traits.as_ref().unwrap().iter() {
3389 let module = binding.module().unwrap();
3390 let mut ident = ident;
3391 if ident.ctxt.glob_adjust(module.expansion, binding.span.ctxt.modern()).is_none() {
3394 if self.resolve_ident_in_module_unadjusted(module, ident, ns, false, false, module.span)
3396 let import_id = match binding.kind {
3397 NameBindingKind::Import { directive, .. } => {
3398 self.maybe_unused_trait_imports.insert(directive.id);
3399 self.add_to_glob_map(directive.id, trait_name);
3404 let trait_def_id = module.def_id().unwrap();
3405 found_traits.push(TraitCandidate { def_id: trait_def_id, import_id: import_id });
3410 /// When name resolution fails, this method can be used to look up candidate
3411 /// entities with the expected name. It allows filtering them using the
3412 /// supplied predicate (which should be used to only accept the types of
3413 /// definitions expected e.g. traits). The lookup spans across all crates.
3415 /// NOTE: The method does not look into imports, but this is not a problem,
3416 /// since we report the definitions (thus, the de-aliased imports).
3417 fn lookup_import_candidates<FilterFn>(&mut self,
3419 namespace: Namespace,
3420 filter_fn: FilterFn)
3421 -> Vec<ImportSuggestion>
3422 where FilterFn: Fn(Def) -> bool
3424 let mut candidates = Vec::new();
3425 let mut worklist = Vec::new();
3426 let mut seen_modules = FxHashSet();
3427 worklist.push((self.graph_root, Vec::new(), false));
3429 while let Some((in_module,
3431 in_module_is_extern)) = worklist.pop() {
3432 self.populate_module_if_necessary(in_module);
3434 // We have to visit module children in deterministic order to avoid
3435 // instabilities in reported imports (#43552).
3436 in_module.for_each_child_stable(|ident, ns, name_binding| {
3437 // avoid imports entirely
3438 if name_binding.is_import() && !name_binding.is_extern_crate() { return; }
3439 // avoid non-importable candidates as well
3440 if !name_binding.is_importable() { return; }
3442 // collect results based on the filter function
3443 if ident.name == lookup_name && ns == namespace {
3444 if filter_fn(name_binding.def()) {
3446 let mut segms = path_segments.clone();
3447 segms.push(ast::PathSegment::from_ident(ident, name_binding.span));
3449 span: name_binding.span,
3452 // the entity is accessible in the following cases:
3453 // 1. if it's defined in the same crate, it's always
3454 // accessible (since private entities can be made public)
3455 // 2. if it's defined in another crate, it's accessible
3456 // only if both the module is public and the entity is
3457 // declared as public (due to pruning, we don't explore
3458 // outside crate private modules => no need to check this)
3459 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
3460 candidates.push(ImportSuggestion { path: path });
3465 // collect submodules to explore
3466 if let Some(module) = name_binding.module() {
3468 let mut path_segments = path_segments.clone();
3469 path_segments.push(ast::PathSegment::from_ident(ident, name_binding.span));
3471 if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
3472 // add the module to the lookup
3473 let is_extern = in_module_is_extern || name_binding.is_extern_crate();
3474 if seen_modules.insert(module.def_id().unwrap()) {
3475 worklist.push((module, path_segments, is_extern));
3485 fn record_def(&mut self, node_id: NodeId, resolution: PathResolution) {
3486 debug!("(recording def) recording {:?} for {}", resolution, node_id);
3487 if let Some(prev_res) = self.def_map.insert(node_id, resolution) {
3488 panic!("path resolved multiple times ({:?} before, {:?} now)", prev_res, resolution);
3492 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
3494 ast::Visibility::Public => ty::Visibility::Public,
3495 ast::Visibility::Crate(..) => ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX)),
3496 ast::Visibility::Inherited => {
3497 ty::Visibility::Restricted(self.current_module.normal_ancestor_id)
3499 ast::Visibility::Restricted { ref path, id } => {
3500 let def = self.smart_resolve_path(id, None, path,
3501 PathSource::Visibility).base_def();
3502 if def == Def::Err {
3503 ty::Visibility::Public
3505 let vis = ty::Visibility::Restricted(def.def_id());
3506 if self.is_accessible(vis) {
3509 self.session.span_err(path.span, "visibilities can only be restricted \
3510 to ancestor modules");
3511 ty::Visibility::Public
3518 fn is_accessible(&self, vis: ty::Visibility) -> bool {
3519 vis.is_accessible_from(self.current_module.normal_ancestor_id, self)
3522 fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
3523 vis.is_accessible_from(module.normal_ancestor_id, self)
3526 fn report_errors(&mut self, krate: &Crate) {
3527 self.report_shadowing_errors();
3528 self.report_with_use_injections(krate);
3529 let mut reported_spans = FxHashSet();
3531 for &AmbiguityError { span, name, b1, b2, lexical, legacy } in &self.ambiguity_errors {
3532 if !reported_spans.insert(span) { continue }
3533 let participle = |binding: &NameBinding| {
3534 if binding.is_import() { "imported" } else { "defined" }
3536 let msg1 = format!("`{}` could refer to the name {} here", name, participle(b1));
3537 let msg2 = format!("`{}` could also refer to the name {} here", name, participle(b2));
3538 let note = if b1.expansion == Mark::root() || !lexical && b1.is_glob_import() {
3539 format!("consider adding an explicit import of `{}` to disambiguate", name)
3540 } else if let Def::Macro(..) = b1.def() {
3541 format!("macro-expanded {} do not shadow",
3542 if b1.is_import() { "macro imports" } else { "macros" })
3544 format!("macro-expanded {} do not shadow when used in a macro invocation path",
3545 if b1.is_import() { "imports" } else { "items" })
3548 let id = match b2.kind {
3549 NameBindingKind::Import { directive, .. } => directive.id,
3550 _ => unreachable!(),
3552 let mut span = MultiSpan::from_span(span);
3553 span.push_span_label(b1.span, msg1);
3554 span.push_span_label(b2.span, msg2);
3555 let msg = format!("`{}` is ambiguous", name);
3556 self.session.buffer_lint(lint::builtin::LEGACY_IMPORTS, id, span, &msg);
3559 self.session.struct_span_err(span, &format!("`{}` is ambiguous", name));
3560 err.span_note(b1.span, &msg1);
3562 Def::Macro(..) if b2.span == DUMMY_SP =>
3563 err.note(&format!("`{}` is also a builtin macro", name)),
3564 _ => err.span_note(b2.span, &msg2),
3566 err.note(¬e).emit();
3570 for &PrivacyError(span, name, binding) in &self.privacy_errors {
3571 if !reported_spans.insert(span) { continue }
3572 span_err!(self.session, span, E0603, "{} `{}` is private", binding.descr(), name);
3576 fn report_with_use_injections(&mut self, krate: &Crate) {
3577 for UseError { mut err, candidates, node_id, better } in self.use_injections.drain(..) {
3578 let mut finder = UsePlacementFinder {
3579 target_module: node_id,
3583 visit::walk_crate(&mut finder, krate);
3584 if !candidates.is_empty() {
3585 let span = finder.span.expect("did not find module");
3586 show_candidates(&mut err, span, &candidates, better, finder.found_use);
3592 fn report_shadowing_errors(&mut self) {
3593 for (ident, scope) in replace(&mut self.lexical_macro_resolutions, Vec::new()) {
3594 self.resolve_legacy_scope(scope, ident, true);
3597 let mut reported_errors = FxHashSet();
3598 for binding in replace(&mut self.disallowed_shadowing, Vec::new()) {
3599 if self.resolve_legacy_scope(&binding.parent, binding.ident, false).is_some() &&
3600 reported_errors.insert((binding.ident, binding.span)) {
3601 let msg = format!("`{}` is already in scope", binding.ident);
3602 self.session.struct_span_err(binding.span, &msg)
3603 .note("macro-expanded `macro_rules!`s may not shadow \
3604 existing macros (see RFC 1560)")
3610 fn report_conflict(&mut self,
3614 new_binding: &NameBinding,
3615 old_binding: &NameBinding) {
3616 // Error on the second of two conflicting names
3617 if old_binding.span.lo > new_binding.span.lo {
3618 return self.report_conflict(parent, ident, ns, old_binding, new_binding);
3621 let container = match parent.kind {
3622 ModuleKind::Def(Def::Mod(_), _) => "module",
3623 ModuleKind::Def(Def::Trait(_), _) => "trait",
3624 ModuleKind::Block(..) => "block",
3628 let old_noun = match old_binding.is_import() {
3630 false => "definition",
3633 let new_participle = match new_binding.is_import() {
3638 let (name, span) = (ident.name, new_binding.span);
3640 if let Some(s) = self.name_already_seen.get(&name) {
3646 let old_kind = match (ns, old_binding.module()) {
3647 (ValueNS, _) => "value",
3648 (MacroNS, _) => "macro",
3649 (TypeNS, _) if old_binding.is_extern_crate() => "extern crate",
3650 (TypeNS, Some(module)) if module.is_normal() => "module",
3651 (TypeNS, Some(module)) if module.is_trait() => "trait",
3652 (TypeNS, _) => "type",
3655 let namespace = match ns {
3661 let msg = format!("the name `{}` is defined multiple times", name);
3663 let mut err = match (old_binding.is_extern_crate(), new_binding.is_extern_crate()) {
3664 (true, true) => struct_span_err!(self.session, span, E0259, "{}", msg),
3665 (true, _) | (_, true) => match new_binding.is_import() && old_binding.is_import() {
3666 true => struct_span_err!(self.session, span, E0254, "{}", msg),
3667 false => struct_span_err!(self.session, span, E0260, "{}", msg),
3669 _ => match (old_binding.is_import(), new_binding.is_import()) {
3670 (false, false) => struct_span_err!(self.session, span, E0428, "{}", msg),
3671 (true, true) => struct_span_err!(self.session, span, E0252, "{}", msg),
3672 _ => struct_span_err!(self.session, span, E0255, "{}", msg),
3676 err.note(&format!("`{}` must be defined only once in the {} namespace of this {}",
3681 err.span_label(span, format!("`{}` re{} here", name, new_participle));
3682 if old_binding.span != syntax_pos::DUMMY_SP {
3683 err.span_label(old_binding.span, format!("previous {} of the {} `{}` here",
3684 old_noun, old_kind, name));
3688 self.name_already_seen.insert(name, span);
3691 fn warn_legacy_self_import(&self, directive: &'a ImportDirective<'a>) {
3692 let (id, span) = (directive.id, directive.span);
3693 let msg = "`self` no longer imports values";
3694 self.session.buffer_lint(lint::builtin::LEGACY_IMPORTS, id, span, msg);
3697 fn check_proc_macro_attrs(&mut self, attrs: &[ast::Attribute]) {
3698 if self.proc_macro_enabled { return; }
3701 if attr.path.segments.len() > 1 {
3704 let ident = attr.path.segments[0].identifier;
3705 let result = self.resolve_lexical_macro_path_segment(ident,
3709 if let Ok(binding) = result {
3710 if let SyntaxExtension::AttrProcMacro(..) = *binding.binding().get_macro(self) {
3711 attr::mark_known(attr);
3713 let msg = "attribute procedural macros are experimental";
3714 let feature = "proc_macro";
3716 feature_err(&self.session.parse_sess, feature,
3717 attr.span, GateIssue::Language, msg)
3718 .span_note(binding.span(), "procedural macro imported here")
3726 fn is_struct_like(def: Def) -> bool {
3728 Def::VariantCtor(_, CtorKind::Fictive) => true,
3729 _ => PathSource::Struct.is_expected(def),
3733 fn is_self_type(path: &[SpannedIdent], namespace: Namespace) -> bool {
3734 namespace == TypeNS && path.len() == 1 && path[0].node.name == keywords::SelfType.name()
3737 fn is_self_value(path: &[SpannedIdent], namespace: Namespace) -> bool {
3738 namespace == ValueNS && path.len() == 1 && path[0].node.name == keywords::SelfValue.name()
3741 fn names_to_string(idents: &[SpannedIdent]) -> String {
3742 let mut result = String::new();
3743 for (i, ident) in idents.iter()
3744 .filter(|i| i.node.name != keywords::CrateRoot.name())
3747 result.push_str("::");
3749 result.push_str(&ident.node.name.as_str());
3754 fn path_names_to_string(path: &Path) -> String {
3755 names_to_string(&path.segments.iter()
3756 .map(|seg| respan(seg.span, seg.identifier))
3757 .collect::<Vec<_>>())
3760 /// Get the path for an enum and the variant from an `ImportSuggestion` for an enum variant.
3761 fn import_candidate_to_paths(suggestion: &ImportSuggestion) -> (Span, String, String) {
3762 let variant_path = &suggestion.path;
3763 let variant_path_string = path_names_to_string(variant_path);
3765 let path_len = suggestion.path.segments.len();
3766 let enum_path = ast::Path {
3767 span: suggestion.path.span,
3768 segments: suggestion.path.segments[0..path_len - 1].to_vec(),
3770 let enum_path_string = path_names_to_string(&enum_path);
3772 (suggestion.path.span, variant_path_string, enum_path_string)
3776 /// When an entity with a given name is not available in scope, we search for
3777 /// entities with that name in all crates. This method allows outputting the
3778 /// results of this search in a programmer-friendly way
3779 fn show_candidates(err: &mut DiagnosticBuilder,
3781 candidates: &[ImportSuggestion],
3785 // we want consistent results across executions, but candidates are produced
3786 // by iterating through a hash map, so make sure they are ordered:
3787 let mut path_strings: Vec<_> =
3788 candidates.into_iter().map(|c| path_names_to_string(&c.path)).collect();
3789 path_strings.sort();
3791 let better = if better { "better " } else { "" };
3792 let msg_diff = match path_strings.len() {
3793 1 => " is found in another module, you can import it",
3794 _ => "s are found in other modules, you can import them",
3796 let msg = format!("possible {}candidate{} into scope", better, msg_diff);
3798 for candidate in &mut path_strings {
3799 // produce an additional newline to separate the new use statement
3800 // from the directly following item.
3801 let additional_newline = if found_use {
3806 *candidate = format!("use {};\n{}", candidate, additional_newline);
3809 err.span_suggestions(span, &msg, path_strings);
3812 /// A somewhat inefficient routine to obtain the name of a module.
3813 fn module_to_string(module: Module) -> String {
3814 let mut names = Vec::new();
3816 fn collect_mod(names: &mut Vec<Ident>, module: Module) {
3817 if let ModuleKind::Def(_, name) = module.kind {
3818 if let Some(parent) = module.parent {
3819 names.push(Ident::with_empty_ctxt(name));
3820 collect_mod(names, parent);
3823 // danger, shouldn't be ident?
3824 names.push(Ident::from_str("<opaque>"));
3825 collect_mod(names, module.parent.unwrap());
3828 collect_mod(&mut names, module);
3830 if names.is_empty() {
3831 return "???".to_string();
3833 names_to_string(&names.into_iter()
3835 .map(|n| dummy_spanned(n))
3836 .collect::<Vec<_>>())
3839 fn err_path_resolution() -> PathResolution {
3840 PathResolution::new(Def::Err)
3843 #[derive(PartialEq,Copy, Clone)]
3844 pub enum MakeGlobMap {
3849 __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }