1 // Copyright 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 use self::ImportDirectiveSubclass::*;
13 use {AmbiguityError, Module, PerNS};
14 use Namespace::{self, TypeNS, MacroNS};
15 use {NameBinding, NameBindingKind, PathResult, PrivacyError};
17 use {names_to_string, module_to_string};
18 use {resolve_error, ResolutionError};
21 use rustc::lint::builtin::PUB_USE_OF_PRIVATE_EXTERN_CRATE;
22 use rustc::hir::def_id::DefId;
23 use rustc::hir::def::*;
24 use rustc::util::nodemap::{FxHashMap, FxHashSet};
26 use syntax::ast::{Ident, Name, SpannedIdent, NodeId};
27 use syntax::ext::base::Determinacy::{self, Determined, Undetermined};
28 use syntax::ext::hygiene::Mark;
29 use syntax::parse::token;
30 use syntax::symbol::keywords;
31 use syntax::util::lev_distance::find_best_match_for_name;
34 use std::cell::{Cell, RefCell};
37 /// Contains data for specific types of import directives.
38 #[derive(Clone, Debug)]
39 pub enum ImportDirectiveSubclass<'a> {
43 result: PerNS<Cell<Result<&'a NameBinding<'a>, Determinacy>>>,
48 max_vis: Cell<ty::Visibility>, // The visibility of the greatest reexport.
49 // n.b. `max_vis` is only used in `finalize_import` to check for reexport errors.
51 ExternCrate(Option<Name>),
55 /// One import directive.
56 #[derive(Debug,Clone)]
57 pub struct ImportDirective<'a> {
59 pub parent: Module<'a>,
60 pub module_path: Vec<SpannedIdent>,
61 pub imported_module: Cell<Option<Module<'a>>>, // the resolution of `module_path`
62 pub subclass: ImportDirectiveSubclass<'a>,
64 pub vis: Cell<ty::Visibility>,
69 impl<'a> ImportDirective<'a> {
70 pub fn is_glob(&self) -> bool {
71 match self.subclass { ImportDirectiveSubclass::GlobImport { .. } => true, _ => false }
75 #[derive(Clone, Default)]
76 /// Records information about the resolution of a name in a namespace of a module.
77 pub struct NameResolution<'a> {
78 /// The single imports that define the name in the namespace.
79 single_imports: SingleImports<'a>,
80 /// The least shadowable known binding for this name, or None if there are no known bindings.
81 pub binding: Option<&'a NameBinding<'a>>,
82 shadows_glob: Option<&'a NameBinding<'a>>,
85 #[derive(Clone, Debug)]
86 enum SingleImports<'a> {
87 /// No single imports can define the name in the namespace.
89 /// Only the given single import can define the name in the namespace.
90 MaybeOne(&'a ImportDirective<'a>),
91 /// At least one single import will define the name in the namespace.
95 impl<'a> Default for SingleImports<'a> {
96 /// Creates a `SingleImports<'a>` of None type.
97 fn default() -> Self {
102 impl<'a> SingleImports<'a> {
103 fn add_directive(&mut self, directive: &'a ImportDirective<'a>) {
105 SingleImports::None => *self = SingleImports::MaybeOne(directive),
106 // If two single imports can define the name in the namespace, we can assume that at
107 // least one of them will define it since otherwise both would have to define only one
108 // namespace, leading to a duplicate error.
109 SingleImports::MaybeOne(_) => *self = SingleImports::AtLeastOne,
110 SingleImports::AtLeastOne => {}
114 fn directive_failed(&mut self) {
116 SingleImports::None => unreachable!(),
117 SingleImports::MaybeOne(_) => *self = SingleImports::None,
118 SingleImports::AtLeastOne => {}
123 impl<'a> NameResolution<'a> {
124 // Returns the binding for the name if it is known or None if it not known.
125 fn binding(&self) -> Option<&'a NameBinding<'a>> {
126 self.binding.and_then(|binding| match self.single_imports {
127 SingleImports::None => Some(binding),
128 _ if !binding.is_glob_import() => Some(binding),
129 _ => None, // The binding could be shadowed by a single import, so it is not known.
134 impl<'a> Resolver<'a> {
135 fn resolution(&self, module: Module<'a>, ident: Ident, ns: Namespace)
136 -> &'a RefCell<NameResolution<'a>> {
137 *module.resolutions.borrow_mut().entry((ident.modern(), ns))
138 .or_insert_with(|| self.arenas.alloc_name_resolution())
141 /// Attempts to resolve `ident` in namespaces `ns` of `module`.
142 /// Invariant: if `record_used` is `Some`, import resolution must be complete.
143 pub fn resolve_ident_in_module_unadjusted(&mut self,
147 restricted_shadowing: bool,
150 -> Result<&'a NameBinding<'a>, Determinacy> {
151 self.populate_module_if_necessary(module);
153 let resolution = self.resolution(module, ident, ns)
155 .map_err(|_| Determined)?; // This happens when there is a cycle of imports
158 if let Some(binding) = resolution.binding {
159 if let Some(shadowed_glob) = resolution.shadows_glob {
160 let name = ident.name;
161 // Forbid expanded shadowing to avoid time travel.
162 if restricted_shadowing &&
163 binding.expansion != Mark::root() &&
164 ns != MacroNS && // In MacroNS, `try_define` always forbids this shadowing
165 binding.def() != shadowed_glob.def() {
166 self.ambiguity_errors.push(AmbiguityError {
176 if self.record_use(ident, ns, binding, path_span) {
177 return Ok(self.dummy_binding);
179 if !self.is_accessible(binding.vis) {
180 self.privacy_errors.push(PrivacyError(path_span, ident.name, binding));
184 return resolution.binding.ok_or(Determined);
187 let check_usable = |this: &mut Self, binding: &'a NameBinding<'a>| {
188 // `extern crate` are always usable for backwards compatability, see issue #37020.
189 let usable = this.is_accessible(binding.vis) || binding.is_extern_crate();
190 if usable { Ok(binding) } else { Err(Determined) }
193 // Items and single imports are not shadowable.
194 if let Some(binding) = resolution.binding {
195 if !binding.is_glob_import() {
196 return check_usable(self, binding);
200 // Check if a single import can still define the name.
201 match resolution.single_imports {
202 SingleImports::AtLeastOne => return Err(Undetermined),
203 SingleImports::MaybeOne(directive) if self.is_accessible(directive.vis.get()) => {
204 let module = match directive.imported_module.get() {
205 Some(module) => module,
206 None => return Err(Undetermined),
208 let ident = match directive.subclass {
209 SingleImport { source, .. } => source,
212 match self.resolve_ident_in_module(module, ident, ns, false, false, path_span) {
213 Err(Determined) => {}
214 _ => return Err(Undetermined),
217 SingleImports::MaybeOne(_) | SingleImports::None => {},
220 let no_unresolved_invocations =
221 restricted_shadowing || module.unresolved_invocations.borrow().is_empty();
222 match resolution.binding {
223 // In `MacroNS`, expanded bindings do not shadow (enforced in `try_define`).
224 Some(binding) if no_unresolved_invocations || ns == MacroNS =>
225 return check_usable(self, binding),
226 None if no_unresolved_invocations => {}
227 _ => return Err(Undetermined),
230 // Check if the globs are determined
231 if restricted_shadowing && module.def().is_some() {
232 return Err(Determined);
234 for directive in module.globs.borrow().iter() {
235 if !self.is_accessible(directive.vis.get()) {
238 let module = unwrap_or!(directive.imported_module.get(), return Err(Undetermined));
239 let (orig_current_module, mut ident) = (self.current_module, ident.modern());
240 match ident.ctxt.glob_adjust(module.expansion, directive.span.ctxt().modern()) {
241 Some(Some(def)) => self.current_module = self.macro_def_scope(def),
245 let result = self.resolve_ident_in_module_unadjusted(
246 module, ident, ns, false, false, path_span,
248 self.current_module = orig_current_module;
249 if let Err(Undetermined) = result {
250 return Err(Undetermined);
257 // Add an import directive to the current module.
258 pub fn add_import_directive(&mut self,
259 module_path: Vec<SpannedIdent>,
260 subclass: ImportDirectiveSubclass<'a>,
265 let current_module = self.current_module;
266 let directive = self.arenas.alloc_import_directive(ImportDirective {
267 parent: current_module,
269 imported_module: Cell::new(None),
275 used: Cell::new(false),
278 self.indeterminate_imports.push(directive);
279 match directive.subclass {
280 SingleImport { target, .. } => {
281 self.per_ns(|this, ns| {
282 let mut resolution = this.resolution(current_module, target, ns).borrow_mut();
283 resolution.single_imports.add_directive(directive);
286 // We don't add prelude imports to the globs since they only affect lexical scopes,
287 // which are not relevant to import resolution.
288 GlobImport { is_prelude: true, .. } => {}
289 GlobImport { .. } => self.current_module.globs.borrow_mut().push(directive),
294 // Given a binding and an import directive that resolves to it,
295 // return the corresponding binding defined by the import directive.
296 pub fn import(&self, binding: &'a NameBinding<'a>, directive: &'a ImportDirective<'a>)
297 -> &'a NameBinding<'a> {
298 let vis = if binding.pseudo_vis().is_at_least(directive.vis.get(), self) ||
299 // c.f. `PUB_USE_OF_PRIVATE_EXTERN_CRATE`
300 !directive.is_glob() && binding.is_extern_crate() {
306 if let GlobImport { ref max_vis, .. } = directive.subclass {
307 if vis == directive.vis.get() || vis.is_at_least(max_vis.get(), self) {
312 self.arenas.alloc_name_binding(NameBinding {
313 kind: NameBindingKind::Import {
316 used: Cell::new(false),
317 legacy_self_import: false,
319 span: directive.span,
321 expansion: directive.expansion,
325 // Define the name or return the existing binding if there is a collision.
326 pub fn try_define(&mut self,
330 binding: &'a NameBinding<'a>)
331 -> Result<(), &'a NameBinding<'a>> {
332 self.update_resolution(module, ident, ns, |this, resolution| {
333 if let Some(old_binding) = resolution.binding {
334 if binding.is_glob_import() {
335 if !old_binding.is_glob_import() &&
336 !(ns == MacroNS && old_binding.expansion != Mark::root()) {
337 resolution.shadows_glob = Some(binding);
338 } else if binding.def() != old_binding.def() {
339 resolution.binding = Some(this.ambiguity(old_binding, binding));
340 } else if !old_binding.vis.is_at_least(binding.vis, &*this) {
341 // We are glob-importing the same item but with greater visibility.
342 resolution.binding = Some(binding);
344 } else if old_binding.is_glob_import() {
345 if ns == MacroNS && binding.expansion != Mark::root() &&
346 binding.def() != old_binding.def() {
347 resolution.binding = Some(this.ambiguity(binding, old_binding));
349 resolution.binding = Some(binding);
350 resolution.shadows_glob = Some(old_binding);
353 return Err(old_binding);
356 resolution.binding = Some(binding);
363 pub fn ambiguity(&self, b1: &'a NameBinding<'a>, b2: &'a NameBinding<'a>)
364 -> &'a NameBinding<'a> {
365 self.arenas.alloc_name_binding(NameBinding {
366 kind: NameBindingKind::Ambiguity { b1: b1, b2: b2, legacy: false },
367 vis: if b1.vis.is_at_least(b2.vis, self) { b1.vis } else { b2.vis },
369 expansion: Mark::root(),
373 // Use `f` to mutate the resolution of the name in the module.
374 // If the resolution becomes a success, define it in the module's glob importers.
375 fn update_resolution<T, F>(&mut self, module: Module<'a>, ident: Ident, ns: Namespace, f: F)
377 where F: FnOnce(&mut Resolver<'a>, &mut NameResolution<'a>) -> T
379 // Ensure that `resolution` isn't borrowed when defining in the module's glob importers,
380 // during which the resolution might end up getting re-defined via a glob cycle.
382 let resolution = &mut *self.resolution(module, ident, ns).borrow_mut();
383 let old_binding = resolution.binding();
385 let t = f(self, resolution);
387 match resolution.binding() {
388 _ if old_binding.is_some() => return t,
390 Some(binding) => match old_binding {
391 Some(old_binding) if old_binding as *const _ == binding as *const _ => return t,
397 // Define `binding` in `module`s glob importers.
398 for directive in module.glob_importers.borrow_mut().iter() {
399 let mut ident = ident.modern();
400 let scope = match ident.ctxt.reverse_glob_adjust(module.expansion,
401 directive.span.ctxt().modern()) {
402 Some(Some(def)) => self.macro_def_scope(def),
403 Some(None) => directive.parent,
406 if self.is_accessible_from(binding.vis, scope) {
407 let imported_binding = self.import(binding, directive);
408 let _ = self.try_define(directive.parent, ident, ns, imported_binding);
415 // Define a "dummy" resolution containing a Def::Err as a placeholder for a
417 fn import_dummy_binding(&mut self, directive: &'a ImportDirective<'a>) {
418 if let SingleImport { target, .. } = directive.subclass {
419 let dummy_binding = self.dummy_binding;
420 let dummy_binding = self.import(dummy_binding, directive);
421 self.per_ns(|this, ns| {
422 let _ = this.try_define(directive.parent, target, ns, dummy_binding);
428 pub struct ImportResolver<'a, 'b: 'a> {
429 pub resolver: &'a mut Resolver<'b>,
432 impl<'a, 'b: 'a> ::std::ops::Deref for ImportResolver<'a, 'b> {
433 type Target = Resolver<'b>;
434 fn deref(&self) -> &Resolver<'b> {
439 impl<'a, 'b: 'a> ::std::ops::DerefMut for ImportResolver<'a, 'b> {
440 fn deref_mut(&mut self) -> &mut Resolver<'b> {
445 impl<'a, 'b: 'a> ty::DefIdTree for &'a ImportResolver<'a, 'b> {
446 fn parent(self, id: DefId) -> Option<DefId> {
447 self.resolver.parent(id)
451 impl<'a, 'b:'a> ImportResolver<'a, 'b> {
454 // This is a fixed-point algorithm. We resolve imports until our efforts
455 // are stymied by an unresolved import; then we bail out of the current
456 // module and continue. We terminate successfully once no more imports
457 // remain or unsuccessfully when no forward progress in resolving imports
460 /// Resolves all imports for the crate. This method performs the fixed-
462 pub fn resolve_imports(&mut self) {
463 let mut prev_num_indeterminates = self.indeterminate_imports.len() + 1;
464 while self.indeterminate_imports.len() < prev_num_indeterminates {
465 prev_num_indeterminates = self.indeterminate_imports.len();
466 for import in mem::replace(&mut self.indeterminate_imports, Vec::new()) {
467 match self.resolve_import(&import) {
468 true => self.determined_imports.push(import),
469 false => self.indeterminate_imports.push(import),
475 pub fn finalize_imports(&mut self) {
476 for module in self.arenas.local_modules().iter() {
477 self.finalize_resolutions_in(module);
480 let mut errors = false;
481 let mut seen_spans = FxHashSet();
482 for i in 0 .. self.determined_imports.len() {
483 let import = self.determined_imports[i];
484 if let Some((span, err)) = self.finalize_import(import) {
487 if let SingleImport { source, ref result, .. } = import.subclass {
488 if source.name == "self" {
489 // Silence `unresolved import` error if E0429 is already emitted
490 match result.value_ns.get() {
491 Err(Determined) => continue,
497 // If the error is a single failed import then create a "fake" import
498 // resolution for it so that later resolve stages won't complain.
499 self.import_dummy_binding(import);
500 if !seen_spans.contains(&span) {
501 let path = import_path_to_string(&import.module_path[..],
504 let error = ResolutionError::UnresolvedImport(Some((span, &path, &err)));
505 resolve_error(self.resolver, span, error);
506 seen_spans.insert(span);
511 // Report unresolved imports only if no hard error was already reported
512 // to avoid generating multiple errors on the same import.
514 if let Some(import) = self.indeterminate_imports.iter().next() {
515 let error = ResolutionError::UnresolvedImport(None);
516 resolve_error(self.resolver, import.span, error);
521 /// Attempts to resolve the given import, returning true if its resolution is determined.
522 /// If successful, the resolved bindings are written into the module.
523 fn resolve_import(&mut self, directive: &'b ImportDirective<'b>) -> bool {
524 debug!("(resolving import for module) resolving import `{}::...` in `{}`",
525 names_to_string(&directive.module_path[..]),
526 module_to_string(self.current_module));
528 self.current_module = directive.parent;
530 let module = if let Some(module) = directive.imported_module.get() {
533 let vis = directive.vis.get();
534 // For better failure detection, pretend that the import will not define any names
535 // while resolving its module path.
536 directive.vis.set(ty::Visibility::Invisible);
537 let result = self.resolve_path(&directive.module_path[..], None, false, directive.span);
538 directive.vis.set(vis);
541 PathResult::Module(module) => module,
542 PathResult::Indeterminate => return false,
547 directive.imported_module.set(Some(module));
548 let (source, target, result, type_ns_only) = match directive.subclass {
549 SingleImport { source, target, ref result, type_ns_only } =>
550 (source, target, result, type_ns_only),
551 GlobImport { .. } => {
552 self.resolve_glob_import(directive);
558 let mut indeterminate = false;
559 self.per_ns(|this, ns| if !type_ns_only || ns == TypeNS {
560 if let Err(Undetermined) = result[ns].get() {
561 result[ns].set(this.resolve_ident_in_module(module,
571 let parent = directive.parent;
572 match result[ns].get() {
573 Err(Undetermined) => indeterminate = true,
575 this.update_resolution(parent, target, ns, |_, resolution| {
576 resolution.single_imports.directive_failed()
579 Ok(binding) if !binding.is_importable() => {
580 let msg = format!("`{}` is not directly importable", target);
581 struct_span_err!(this.session, directive.span, E0253, "{}", &msg)
582 .span_label(directive.span, "cannot be imported directly")
584 // Do not import this illegal binding. Import a dummy binding and pretend
585 // everything is fine
586 this.import_dummy_binding(directive);
589 let imported_binding = this.import(binding, directive);
590 let conflict = this.try_define(parent, target, ns, imported_binding);
591 if let Err(old_binding) = conflict {
592 this.report_conflict(parent, target, ns, imported_binding, old_binding);
601 // If appropriate, returns an error to report.
602 fn finalize_import(&mut self, directive: &'b ImportDirective<'b>) -> Option<(Span, String)> {
603 self.current_module = directive.parent;
605 let ImportDirective { ref module_path, span, .. } = *directive;
606 let module_result = self.resolve_path(&module_path, None, true, span);
607 let module = match module_result {
608 PathResult::Module(module) => module,
609 PathResult::Failed(span, msg, _) => {
610 let (mut self_path, mut self_result) = (module_path.clone(), None);
611 if !self_path.is_empty() &&
612 !token::Ident(self_path[0].node).is_path_segment_keyword()
614 self_path[0].node.name = keywords::SelfValue.name();
615 self_result = Some(self.resolve_path(&self_path, None, false, span));
617 return if let Some(PathResult::Module(..)) = self_result {
618 Some((span, format!("Did you mean `{}`?", names_to_string(&self_path[..]))))
626 let (ident, result, type_ns_only) = match directive.subclass {
627 SingleImport { source, ref result, type_ns_only, .. } => (source, result, type_ns_only),
628 GlobImport { .. } if module.def_id() == directive.parent.def_id() => {
629 // Importing a module into itself is not allowed.
630 return Some((directive.span,
631 "Cannot glob-import a module into itself.".to_string()));
633 GlobImport { is_prelude, ref max_vis } => {
635 max_vis.get() != ty::Visibility::Invisible && // Allow empty globs.
636 !max_vis.get().is_at_least(directive.vis.get(), &*self) {
637 let msg = "A non-empty glob must import something with the glob's visibility";
638 self.session.span_err(directive.span, msg);
645 let mut all_ns_err = true;
646 let mut legacy_self_import = None;
647 self.per_ns(|this, ns| if !type_ns_only || ns == TypeNS {
648 if let Ok(binding) = result[ns].get() {
650 if this.record_use(ident, ns, binding, directive.span) {
651 this.resolution(module, ident, ns).borrow_mut().binding =
652 Some(this.dummy_binding);
655 } else if let Ok(binding) = this.resolve_ident_in_module(module,
661 legacy_self_import = Some(directive);
662 let binding = this.arenas.alloc_name_binding(NameBinding {
663 kind: NameBindingKind::Import {
666 used: Cell::new(false),
667 legacy_self_import: true,
671 let _ = this.try_define(directive.parent, ident, ns, binding);
675 if let Some(directive) = legacy_self_import {
676 self.warn_legacy_self_import(directive);
679 let mut all_ns_failed = true;
680 self.per_ns(|this, ns| if !type_ns_only || ns == TypeNS {
681 match this.resolve_ident_in_module(module, ident, ns, false, true, span) {
682 Ok(_) => all_ns_failed = false,
687 return if all_ns_failed {
688 let resolutions = module.resolutions.borrow();
689 let names = resolutions.iter().filter_map(|(&(ref i, _), resolution)| {
690 if *i == ident { return None; } // Never suggest the same name
691 match *resolution.borrow() {
692 NameResolution { binding: Some(name_binding), .. } => {
693 match name_binding.kind {
694 NameBindingKind::Import { binding, .. } => {
696 // Never suggest the name that has binding error
697 // i.e. the name that cannot be previously resolved
698 NameBindingKind::Def(Def::Err) => return None,
705 NameResolution { single_imports: SingleImports::None, .. } => None,
710 match find_best_match_for_name(names, &ident.name.as_str(), None) {
711 Some(name) => format!(". Did you mean to use `{}`?", name),
712 None => "".to_owned(),
714 let module_str = module_to_string(module);
715 let msg = if &module_str == "???" {
716 format!("no `{}` in the root{}", ident, lev_suggestion)
718 format!("no `{}` in `{}`{}", ident, module_str, lev_suggestion)
722 // `resolve_ident_in_module` reported a privacy error.
723 self.import_dummy_binding(directive);
728 let mut reexport_error = None;
729 let mut any_successful_reexport = false;
730 self.per_ns(|this, ns| {
731 if let Ok(binding) = result[ns].get() {
732 let vis = directive.vis.get();
733 if !binding.pseudo_vis().is_at_least(vis, &*this) {
734 reexport_error = Some((ns, binding));
736 any_successful_reexport = true;
741 // All namespaces must be re-exported with extra visibility for an error to occur.
742 if !any_successful_reexport {
743 let (ns, binding) = reexport_error.unwrap();
744 if ns == TypeNS && binding.is_extern_crate() {
745 let msg = format!("extern crate `{}` is private, and cannot be reexported \
746 (error E0365), consider declaring with `pub`",
748 self.session.buffer_lint(PUB_USE_OF_PRIVATE_EXTERN_CRATE,
752 } else if ns == TypeNS {
753 struct_span_err!(self.session, directive.span, E0365,
754 "`{}` is private, and cannot be reexported", ident)
755 .span_label(directive.span, format!("reexport of private `{}`", ident))
756 .note(&format!("consider declaring type or module `{}` with `pub`", ident))
759 let msg = format!("`{}` is private, and cannot be reexported", ident);
761 format!("consider marking `{}` as `pub` in the imported module", ident);
762 struct_span_err!(self.session, directive.span, E0364, "{}", &msg)
763 .span_note(directive.span, ¬e_msg)
768 // Record what this import resolves to for later uses in documentation,
769 // this may resolve to either a value or a type, but for documentation
770 // purposes it's good enough to just favor one over the other.
771 self.per_ns(|this, ns| if let Some(binding) = result[ns].get().ok() {
772 this.def_map.entry(directive.id).or_insert(PathResolution::new(binding.def()));
775 debug!("(resolving single import) successfully resolved import");
779 fn resolve_glob_import(&mut self, directive: &'b ImportDirective<'b>) {
780 let module = directive.imported_module.get().unwrap();
781 self.populate_module_if_necessary(module);
783 if let Some(Def::Trait(_)) = module.def() {
784 self.session.span_err(directive.span, "items in traits are not importable.");
786 } else if module.def_id() == directive.parent.def_id() {
788 } else if let GlobImport { is_prelude: true, .. } = directive.subclass {
789 self.prelude = Some(module);
793 // Add to module's glob_importers
794 module.glob_importers.borrow_mut().push(directive);
796 // Ensure that `resolutions` isn't borrowed during `try_define`,
797 // since it might get updated via a glob cycle.
798 let bindings = module.resolutions.borrow().iter().filter_map(|(&ident, resolution)| {
799 resolution.borrow().binding().map(|binding| (ident, binding))
800 }).collect::<Vec<_>>();
801 for ((mut ident, ns), binding) in bindings {
802 let scope = match ident.ctxt.reverse_glob_adjust(module.expansion,
803 directive.span.ctxt().modern()) {
804 Some(Some(def)) => self.macro_def_scope(def),
805 Some(None) => self.current_module,
808 if self.is_accessible_from(binding.pseudo_vis(), scope) {
809 let imported_binding = self.import(binding, directive);
810 let _ = self.try_define(directive.parent, ident, ns, imported_binding);
814 // Record the destination of this import
815 self.record_def(directive.id, PathResolution::new(module.def().unwrap()));
818 // Miscellaneous post-processing, including recording reexports,
819 // reporting conflicts, and reporting unresolved imports.
820 fn finalize_resolutions_in(&mut self, module: Module<'b>) {
821 // Since import resolution is finished, globs will not define any more names.
822 *module.globs.borrow_mut() = Vec::new();
824 let mut reexports = Vec::new();
825 let mut exported_macro_names = FxHashMap();
826 if module as *const _ == self.graph_root as *const _ {
827 let macro_exports = mem::replace(&mut self.macro_exports, Vec::new());
828 for export in macro_exports.into_iter().rev() {
829 if exported_macro_names.insert(export.ident.modern(), export.span).is_none() {
830 reexports.push(export);
835 for (&(ident, ns), resolution) in module.resolutions.borrow().iter() {
836 let resolution = &mut *resolution.borrow_mut();
837 let binding = match resolution.binding {
838 Some(binding) => binding,
842 if binding.vis == ty::Visibility::Public &&
843 (binding.is_import() || binding.is_macro_def()) {
844 let def = binding.def();
846 if !def.def_id().is_local() {
847 self.cstore.export_macros_untracked(def.def_id().krate);
849 if let Def::Macro(..) = def {
850 if let Some(&span) = exported_macro_names.get(&ident.modern()) {
852 format!("a macro named `{}` has already been exported", ident);
853 self.session.struct_span_err(span, &msg)
854 .span_label(span, format!("`{}` already exported", ident))
855 .span_note(binding.span, "previous macro export here")
859 reexports.push(Export { ident: ident.modern(), def: def, span: binding.span });
864 NameBindingKind::Import { binding: orig_binding, .. } => {
865 if ns == TypeNS && orig_binding.is_variant() &&
866 !orig_binding.vis.is_at_least(binding.vis, &*self) {
867 let msg = format!("variant `{}` is private, and cannot be reexported, \
868 consider declaring its enum as `pub`", ident);
869 self.session.span_err(binding.span, &msg);
872 NameBindingKind::Ambiguity { b1, b2, .. }
873 if b1.is_glob_import() && b2.is_glob_import() => {
874 let (orig_b1, orig_b2) = match (&b1.kind, &b2.kind) {
875 (&NameBindingKind::Import { binding: b1, .. },
876 &NameBindingKind::Import { binding: b2, .. }) => (b1, b2),
879 let (b1, b2) = match (orig_b1.vis, orig_b2.vis) {
880 (ty::Visibility::Public, ty::Visibility::Public) => continue,
881 (ty::Visibility::Public, _) => (b1, b2),
882 (_, ty::Visibility::Public) => (b2, b1),
885 resolution.binding = Some(self.arenas.alloc_name_binding(NameBinding {
886 kind: NameBindingKind::Ambiguity { b1: b1, b2: b2, legacy: true }, ..*b1
893 if reexports.len() > 0 {
894 if let Some(def_id) = module.def_id() {
895 self.export_map.insert(def_id, reexports);
901 fn import_path_to_string(names: &[SpannedIdent],
902 subclass: &ImportDirectiveSubclass,
903 span: Span) -> String {
904 let pos = names.iter()
905 .position(|p| span == p.span && p.node.name != keywords::CrateRoot.name());
906 let global = !names.is_empty() && names[0].node.name == keywords::CrateRoot.name();
907 if let Some(pos) = pos {
908 let names = if global { &names[1..pos + 1] } else { &names[..pos + 1] };
909 names_to_string(names)
911 let names = if global { &names[1..] } else { names };
912 if names.is_empty() {
913 import_directive_subclass_to_string(subclass)
916 names_to_string(names),
917 import_directive_subclass_to_string(subclass)))
922 fn import_directive_subclass_to_string(subclass: &ImportDirectiveSubclass) -> String {
924 SingleImport { source, .. } => source.to_string(),
925 GlobImport { .. } => "*".to_string(),
926 ExternCrate(_) => "<extern crate>".to_string(),
927 MacroUse => "#[macro_use]".to_string(),