| // Copyright 2015 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| use self::ImportDirectiveSubclass::*; |
| |
| use {AmbiguityError, CrateLint, Module, PerNS}; |
| use Namespace::{self, TypeNS, MacroNS}; |
| use {NameBinding, NameBindingKind, ToNameBinding, PathResult, PrivacyError}; |
| use Resolver; |
| use {names_to_string, module_to_string}; |
| use {resolve_error, ResolutionError}; |
| |
| use rustc_data_structures::ptr_key::PtrKey; |
| use rustc::ty; |
| use rustc::lint::builtin::BuiltinLintDiagnostics; |
| use rustc::lint::builtin::{DUPLICATE_MACRO_EXPORTS, PUB_USE_OF_PRIVATE_EXTERN_CRATE}; |
| use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId}; |
| use rustc::hir::def::*; |
| use rustc::session::DiagnosticMessageId; |
| use rustc::util::nodemap::{FxHashMap, FxHashSet}; |
| |
| use syntax::ast::{Ident, Name, NodeId, CRATE_NODE_ID}; |
| use syntax::ext::base::Determinacy::{self, Determined, Undetermined}; |
| use syntax::ext::hygiene::Mark; |
| use syntax::symbol::keywords; |
| use syntax::util::lev_distance::find_best_match_for_name; |
| use syntax_pos::Span; |
| |
| use std::cell::{Cell, RefCell}; |
| use std::{mem, ptr}; |
| |
| /// Contains data for specific types of import directives. |
| #[derive(Clone, Debug)] |
| pub enum ImportDirectiveSubclass<'a> { |
| SingleImport { |
| target: Ident, |
| source: Ident, |
| result: PerNS<Cell<Result<&'a NameBinding<'a>, Determinacy>>>, |
| type_ns_only: bool, |
| }, |
| GlobImport { |
| is_prelude: bool, |
| max_vis: Cell<ty::Visibility>, // The visibility of the greatest re-export. |
| // n.b. `max_vis` is only used in `finalize_import` to check for re-export errors. |
| }, |
| ExternCrate(Option<Name>), |
| MacroUse, |
| } |
| |
| /// One import directive. |
| #[derive(Debug,Clone)] |
| pub struct ImportDirective<'a> { |
| /// The id of the `extern crate`, `UseTree` etc that imported this `ImportDirective`. |
| /// |
| /// In the case where the `ImportDirective` was expanded from a "nested" use tree, |
| /// this id is the id of the leaf tree. For example: |
| /// |
| /// ```ignore (pacify the mercilous tidy) |
| /// use foo::bar::{a, b} |
| /// ``` |
| /// |
| /// If this is the import directive for `foo::bar::a`, we would have the id of the `UseTree` |
| /// for `a` in this field. |
| pub id: NodeId, |
| |
| /// The `id` of the "root" use-kind -- this is always the same as |
| /// `id` except in the case of "nested" use trees, in which case |
| /// it will be the `id` of the root use tree. e.g., in the example |
| /// from `id`, this would be the id of the `use foo::bar` |
| /// `UseTree` node. |
| pub root_id: NodeId, |
| |
| /// Span of this use tree. |
| pub span: Span, |
| |
| /// Span of the *root* use tree (see `root_id`). |
| pub root_span: Span, |
| |
| pub parent: Module<'a>, |
| pub module_path: Vec<Ident>, |
| pub imported_module: Cell<Option<Module<'a>>>, // the resolution of `module_path` |
| pub subclass: ImportDirectiveSubclass<'a>, |
| pub vis: Cell<ty::Visibility>, |
| pub expansion: Mark, |
| pub used: Cell<bool>, |
| } |
| |
| impl<'a> ImportDirective<'a> { |
| pub fn is_glob(&self) -> bool { |
| match self.subclass { ImportDirectiveSubclass::GlobImport { .. } => true, _ => false } |
| } |
| |
| crate fn crate_lint(&self) -> CrateLint { |
| CrateLint::UsePath { root_id: self.root_id, root_span: self.root_span } |
| } |
| } |
| |
| #[derive(Clone, Default, Debug)] |
| /// Records information about the resolution of a name in a namespace of a module. |
| pub struct NameResolution<'a> { |
| /// Single imports that may define the name in the namespace. |
| /// Import directives are arena-allocated, so it's ok to use pointers as keys. |
| single_imports: FxHashSet<PtrKey<'a, ImportDirective<'a>>>, |
| /// The least shadowable known binding for this name, or None if there are no known bindings. |
| pub binding: Option<&'a NameBinding<'a>>, |
| shadowed_glob: Option<&'a NameBinding<'a>>, |
| } |
| |
| impl<'a> NameResolution<'a> { |
| // Returns the binding for the name if it is known or None if it not known. |
| fn binding(&self) -> Option<&'a NameBinding<'a>> { |
| self.binding.and_then(|binding| { |
| if !binding.is_glob_import() || |
| self.single_imports.is_empty() { Some(binding) } else { None } |
| }) |
| } |
| } |
| |
| impl<'a, 'crateloader> Resolver<'a, 'crateloader> { |
| fn resolution(&self, module: Module<'a>, ident: Ident, ns: Namespace) |
| -> &'a RefCell<NameResolution<'a>> { |
| *module.resolutions.borrow_mut().entry((ident.modern(), ns)) |
| .or_insert_with(|| self.arenas.alloc_name_resolution()) |
| } |
| |
| /// Attempts to resolve `ident` in namespaces `ns` of `module`. |
| /// Invariant: if `record_used` is `Some`, expansion and import resolution must be complete. |
| pub fn resolve_ident_in_module_unadjusted(&mut self, |
| module: Module<'a>, |
| ident: Ident, |
| ns: Namespace, |
| restricted_shadowing: bool, |
| record_used: bool, |
| path_span: Span) |
| -> Result<&'a NameBinding<'a>, Determinacy> { |
| self.populate_module_if_necessary(module); |
| |
| let resolution = self.resolution(module, ident, ns) |
| .try_borrow_mut() |
| .map_err(|_| Determined)?; // This happens when there is a cycle of imports |
| |
| if record_used { |
| if let Some(binding) = resolution.binding { |
| if let Some(shadowed_glob) = resolution.shadowed_glob { |
| let name = ident.name; |
| // Forbid expanded shadowing to avoid time travel. |
| if restricted_shadowing && |
| binding.expansion != Mark::root() && |
| ns != MacroNS && // In MacroNS, `try_define` always forbids this shadowing |
| binding.def() != shadowed_glob.def() { |
| self.ambiguity_errors.push(AmbiguityError { |
| span: path_span, |
| name, |
| lexical: false, |
| b1: binding, |
| b2: shadowed_glob, |
| }); |
| } |
| } |
| if self.record_use(ident, ns, binding, path_span) { |
| return Ok(self.dummy_binding); |
| } |
| if !self.is_accessible(binding.vis) { |
| self.privacy_errors.push(PrivacyError(path_span, ident.name, binding)); |
| } |
| } |
| |
| return resolution.binding.ok_or(Determined); |
| } |
| |
| let check_usable = |this: &mut Self, binding: &'a NameBinding<'a>| { |
| // `extern crate` are always usable for backwards compatibility, see issue #37020. |
| let usable = this.is_accessible(binding.vis) || binding.is_extern_crate(); |
| if usable { Ok(binding) } else { Err(Determined) } |
| }; |
| |
| // Items and single imports are not shadowable, if we have one, then it's determined. |
| if let Some(binding) = resolution.binding { |
| if !binding.is_glob_import() { |
| return check_usable(self, binding); |
| } |
| } |
| |
| // --- From now on we either have a glob resolution or no resolution. --- |
| |
| // Check if one of single imports can still define the name, |
| // if it can then our result is not determined and can be invalidated. |
| for single_import in &resolution.single_imports { |
| if !self.is_accessible(single_import.vis.get()) { |
| continue; |
| } |
| let module = unwrap_or!(single_import.imported_module.get(), return Err(Undetermined)); |
| let ident = match single_import.subclass { |
| SingleImport { source, .. } => source, |
| _ => unreachable!(), |
| }; |
| match self.resolve_ident_in_module(module, ident, ns, false, path_span) { |
| Err(Determined) => continue, |
| Ok(_) | Err(Undetermined) => return Err(Undetermined), |
| } |
| } |
| |
| // So we have a resolution that's from a glob import. This resolution is determined |
| // if it cannot be shadowed by some new item/import expanded from a macro. |
| // This happens either if there are no unexpanded macros, or expanded names cannot |
| // shadow globs (that happens in macro namespace or with restricted shadowing). |
| let unexpanded_macros = !module.unresolved_invocations.borrow().is_empty() || |
| (ns == MacroNS && ptr::eq(module, self.graph_root) && |
| !self.unresolved_invocations_macro_export.is_empty()); |
| if let Some(binding) = resolution.binding { |
| if !unexpanded_macros || ns == MacroNS || restricted_shadowing { |
| return check_usable(self, binding); |
| } else { |
| return Err(Undetermined); |
| } |
| } |
| |
| // --- From now on we have no resolution. --- |
| |
| // Now we are in situation when new item/import can appear only from a glob or a macro |
| // expansion. With restricted shadowing names from globs and macro expansions cannot |
| // shadow names from outer scopes, so we can freely fallback from module search to search |
| // in outer scopes. To continue search in outer scopes we have to lie a bit and return |
| // `Determined` to `resolve_lexical_macro_path_segment` even if the correct answer |
| // for in-module resolution could be `Undetermined`. |
| if restricted_shadowing { |
| return Err(Determined); |
| } |
| |
| // Check if one of unexpanded macros can still define the name, |
| // if it can then our "no resolution" result is not determined and can be invalidated. |
| if unexpanded_macros { |
| return Err(Undetermined); |
| } |
| |
| // Check if one of glob imports can still define the name, |
| // if it can then our "no resolution" result is not determined and can be invalidated. |
| for glob_import in module.globs.borrow().iter() { |
| if !self.is_accessible(glob_import.vis.get()) { |
| continue |
| } |
| let module = unwrap_or!(glob_import.imported_module.get(), return Err(Undetermined)); |
| let (orig_current_module, mut ident) = (self.current_module, ident.modern()); |
| match ident.span.glob_adjust(module.expansion, glob_import.span.ctxt().modern()) { |
| Some(Some(def)) => self.current_module = self.macro_def_scope(def), |
| Some(None) => {} |
| None => continue, |
| }; |
| let result = self.resolve_ident_in_module_unadjusted( |
| module, ident, ns, false, false, path_span, |
| ); |
| self.current_module = orig_current_module; |
| match result { |
| Err(Determined) => continue, |
| Ok(_) | Err(Undetermined) => return Err(Undetermined), |
| } |
| } |
| |
| // No resolution and no one else can define the name - determinate error. |
| Err(Determined) |
| } |
| |
| // Add an import directive to the current module. |
| pub fn add_import_directive(&mut self, |
| module_path: Vec<Ident>, |
| subclass: ImportDirectiveSubclass<'a>, |
| span: Span, |
| id: NodeId, |
| root_span: Span, |
| root_id: NodeId, |
| vis: ty::Visibility, |
| expansion: Mark) { |
| let current_module = self.current_module; |
| let directive = self.arenas.alloc_import_directive(ImportDirective { |
| parent: current_module, |
| module_path, |
| imported_module: Cell::new(None), |
| subclass, |
| span, |
| id, |
| root_span, |
| root_id, |
| vis: Cell::new(vis), |
| expansion, |
| used: Cell::new(false), |
| }); |
| |
| self.indeterminate_imports.push(directive); |
| match directive.subclass { |
| SingleImport { target, type_ns_only, .. } => { |
| self.per_ns(|this, ns| if !type_ns_only || ns == TypeNS { |
| let mut resolution = this.resolution(current_module, target, ns).borrow_mut(); |
| resolution.single_imports.insert(PtrKey(directive)); |
| }); |
| } |
| // We don't add prelude imports to the globs since they only affect lexical scopes, |
| // which are not relevant to import resolution. |
| GlobImport { is_prelude: true, .. } => {} |
| GlobImport { .. } => self.current_module.globs.borrow_mut().push(directive), |
| _ => unreachable!(), |
| } |
| } |
| |
| // Given a binding and an import directive that resolves to it, |
| // return the corresponding binding defined by the import directive. |
| pub fn import(&self, binding: &'a NameBinding<'a>, directive: &'a ImportDirective<'a>) |
| -> &'a NameBinding<'a> { |
| let vis = if binding.pseudo_vis().is_at_least(directive.vis.get(), self) || |
| // c.f. `PUB_USE_OF_PRIVATE_EXTERN_CRATE` |
| !directive.is_glob() && binding.is_extern_crate() { |
| directive.vis.get() |
| } else { |
| binding.pseudo_vis() |
| }; |
| |
| if let GlobImport { ref max_vis, .. } = directive.subclass { |
| if vis == directive.vis.get() || vis.is_at_least(max_vis.get(), self) { |
| max_vis.set(vis) |
| } |
| } |
| |
| self.arenas.alloc_name_binding(NameBinding { |
| kind: NameBindingKind::Import { |
| binding, |
| directive, |
| used: Cell::new(false), |
| }, |
| span: directive.span, |
| vis, |
| expansion: directive.expansion, |
| }) |
| } |
| |
| // Define the name or return the existing binding if there is a collision. |
| pub fn try_define(&mut self, |
| module: Module<'a>, |
| ident: Ident, |
| ns: Namespace, |
| binding: &'a NameBinding<'a>) |
| -> Result<(), &'a NameBinding<'a>> { |
| self.update_resolution(module, ident, ns, |this, resolution| { |
| if let Some(old_binding) = resolution.binding { |
| if binding.is_glob_import() { |
| if !old_binding.is_glob_import() && |
| !(ns == MacroNS && old_binding.expansion != Mark::root()) { |
| resolution.shadowed_glob = Some(binding); |
| } else if binding.def() != old_binding.def() { |
| resolution.binding = Some(this.ambiguity(old_binding, binding)); |
| } else if !old_binding.vis.is_at_least(binding.vis, &*this) { |
| // We are glob-importing the same item but with greater visibility. |
| resolution.binding = Some(binding); |
| } |
| } else if old_binding.is_glob_import() { |
| if ns == MacroNS && binding.expansion != Mark::root() && |
| binding.def() != old_binding.def() { |
| resolution.binding = Some(this.ambiguity(binding, old_binding)); |
| } else { |
| resolution.binding = Some(binding); |
| resolution.shadowed_glob = Some(old_binding); |
| } |
| } else if let (&NameBindingKind::Def(_, true), &NameBindingKind::Def(_, true)) = |
| (&old_binding.kind, &binding.kind) { |
| |
| this.session.buffer_lint_with_diagnostic( |
| DUPLICATE_MACRO_EXPORTS, |
| CRATE_NODE_ID, |
| binding.span, |
| &format!("a macro named `{}` has already been exported", ident), |
| BuiltinLintDiagnostics::DuplicatedMacroExports( |
| ident, old_binding.span, binding.span)); |
| |
| resolution.binding = Some(binding); |
| } else { |
| return Err(old_binding); |
| } |
| } else { |
| resolution.binding = Some(binding); |
| } |
| |
| Ok(()) |
| }) |
| } |
| |
| pub fn ambiguity(&self, b1: &'a NameBinding<'a>, b2: &'a NameBinding<'a>) |
| -> &'a NameBinding<'a> { |
| self.arenas.alloc_name_binding(NameBinding { |
| kind: NameBindingKind::Ambiguity { b1, b2 }, |
| vis: if b1.vis.is_at_least(b2.vis, self) { b1.vis } else { b2.vis }, |
| span: b1.span, |
| expansion: Mark::root(), |
| }) |
| } |
| |
| // Use `f` to mutate the resolution of the name in the module. |
| // If the resolution becomes a success, define it in the module's glob importers. |
| fn update_resolution<T, F>(&mut self, module: Module<'a>, ident: Ident, ns: Namespace, f: F) |
| -> T |
| where F: FnOnce(&mut Resolver<'a, 'crateloader>, &mut NameResolution<'a>) -> T |
| { |
| // Ensure that `resolution` isn't borrowed when defining in the module's glob importers, |
| // during which the resolution might end up getting re-defined via a glob cycle. |
| let (binding, t) = { |
| let resolution = &mut *self.resolution(module, ident, ns).borrow_mut(); |
| let old_binding = resolution.binding(); |
| |
| let t = f(self, resolution); |
| |
| match resolution.binding() { |
| _ if old_binding.is_some() => return t, |
| None => return t, |
| Some(binding) => match old_binding { |
| Some(old_binding) if ptr::eq(old_binding, binding) => return t, |
| _ => (binding, t), |
| } |
| } |
| }; |
| |
| // Define `binding` in `module`s glob importers. |
| for directive in module.glob_importers.borrow_mut().iter() { |
| let mut ident = ident.modern(); |
| let scope = match ident.span.reverse_glob_adjust(module.expansion, |
| directive.span.ctxt().modern()) { |
| Some(Some(def)) => self.macro_def_scope(def), |
| Some(None) => directive.parent, |
| None => continue, |
| }; |
| if self.is_accessible_from(binding.vis, scope) { |
| let imported_binding = self.import(binding, directive); |
| let _ = self.try_define(directive.parent, ident, ns, imported_binding); |
| } |
| } |
| |
| t |
| } |
| |
| // Define a "dummy" resolution containing a Def::Err as a placeholder for a |
| // failed resolution |
| fn import_dummy_binding(&mut self, directive: &'a ImportDirective<'a>) { |
| if let SingleImport { target, .. } = directive.subclass { |
| let dummy_binding = self.dummy_binding; |
| let dummy_binding = self.import(dummy_binding, directive); |
| self.per_ns(|this, ns| { |
| let _ = this.try_define(directive.parent, target, ns, dummy_binding); |
| }); |
| } |
| } |
| } |
| |
| pub struct ImportResolver<'a, 'b: 'a, 'c: 'a + 'b> { |
| pub resolver: &'a mut Resolver<'b, 'c>, |
| } |
| |
| impl<'a, 'b: 'a, 'c: 'a + 'b> ::std::ops::Deref for ImportResolver<'a, 'b, 'c> { |
| type Target = Resolver<'b, 'c>; |
| fn deref(&self) -> &Resolver<'b, 'c> { |
| self.resolver |
| } |
| } |
| |
| impl<'a, 'b: 'a, 'c: 'a + 'b> ::std::ops::DerefMut for ImportResolver<'a, 'b, 'c> { |
| fn deref_mut(&mut self) -> &mut Resolver<'b, 'c> { |
| self.resolver |
| } |
| } |
| |
| impl<'a, 'b: 'a, 'c: 'a + 'b> ty::DefIdTree for &'a ImportResolver<'a, 'b, 'c> { |
| fn parent(self, id: DefId) -> Option<DefId> { |
| self.resolver.parent(id) |
| } |
| } |
| |
| impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> { |
| // Import resolution |
| // |
| // This is a fixed-point algorithm. We resolve imports until our efforts |
| // are stymied by an unresolved import; then we bail out of the current |
| // module and continue. We terminate successfully once no more imports |
| // remain or unsuccessfully when no forward progress in resolving imports |
| // is made. |
| |
| /// Resolves all imports for the crate. This method performs the fixed- |
| /// point iteration. |
| pub fn resolve_imports(&mut self) { |
| let mut prev_num_indeterminates = self.indeterminate_imports.len() + 1; |
| while self.indeterminate_imports.len() < prev_num_indeterminates { |
| prev_num_indeterminates = self.indeterminate_imports.len(); |
| for import in mem::replace(&mut self.indeterminate_imports, Vec::new()) { |
| match self.resolve_import(&import) { |
| true => self.determined_imports.push(import), |
| false => self.indeterminate_imports.push(import), |
| } |
| } |
| } |
| } |
| |
| pub fn finalize_imports(&mut self) { |
| for module in self.arenas.local_modules().iter() { |
| self.finalize_resolutions_in(module); |
| } |
| |
| let mut errors = false; |
| let mut seen_spans = FxHashSet(); |
| for i in 0 .. self.determined_imports.len() { |
| let import = self.determined_imports[i]; |
| if let Some((span, err)) = self.finalize_import(import) { |
| errors = true; |
| |
| if let SingleImport { source, ref result, .. } = import.subclass { |
| if source.name == "self" { |
| // Silence `unresolved import` error if E0429 is already emitted |
| match result.value_ns.get() { |
| Err(Determined) => continue, |
| _ => {}, |
| } |
| } |
| } |
| |
| // If the error is a single failed import then create a "fake" import |
| // resolution for it so that later resolve stages won't complain. |
| self.import_dummy_binding(import); |
| if !seen_spans.contains(&span) { |
| let path = import_path_to_string(&import.module_path[..], |
| &import.subclass, |
| span); |
| let error = ResolutionError::UnresolvedImport(Some((span, &path, &err))); |
| resolve_error(self.resolver, span, error); |
| seen_spans.insert(span); |
| } |
| } |
| } |
| |
| // Report unresolved imports only if no hard error was already reported |
| // to avoid generating multiple errors on the same import. |
| if !errors { |
| if let Some(import) = self.indeterminate_imports.iter().next() { |
| let error = ResolutionError::UnresolvedImport(None); |
| resolve_error(self.resolver, import.span, error); |
| } |
| } |
| } |
| |
| /// Attempts to resolve the given import, returning true if its resolution is determined. |
| /// If successful, the resolved bindings are written into the module. |
| fn resolve_import(&mut self, directive: &'b ImportDirective<'b>) -> bool { |
| debug!("(resolving import for module) resolving import `{}::...` in `{}`", |
| names_to_string(&directive.module_path[..]), |
| module_to_string(self.current_module).unwrap_or("???".to_string())); |
| |
| self.current_module = directive.parent; |
| |
| let module = if let Some(module) = directive.imported_module.get() { |
| module |
| } else { |
| let vis = directive.vis.get(); |
| // For better failure detection, pretend that the import will not define any names |
| // while resolving its module path. |
| directive.vis.set(ty::Visibility::Invisible); |
| let result = self.resolve_path(&directive.module_path[..], None, false, |
| directive.span, directive.crate_lint()); |
| directive.vis.set(vis); |
| |
| match result { |
| PathResult::Module(module) => module, |
| PathResult::Indeterminate => return false, |
| _ => return true, |
| } |
| }; |
| |
| directive.imported_module.set(Some(module)); |
| let (source, target, result, type_ns_only) = match directive.subclass { |
| SingleImport { source, target, ref result, type_ns_only } => |
| (source, target, result, type_ns_only), |
| GlobImport { .. } => { |
| self.resolve_glob_import(directive); |
| return true; |
| } |
| _ => unreachable!(), |
| }; |
| |
| let mut indeterminate = false; |
| self.per_ns(|this, ns| if !type_ns_only || ns == TypeNS { |
| if let Err(Undetermined) = result[ns].get() { |
| result[ns].set(this.resolve_ident_in_module(module, |
| source, |
| ns, |
| false, |
| directive.span)); |
| } else { |
| return |
| }; |
| |
| let parent = directive.parent; |
| match result[ns].get() { |
| Err(Undetermined) => indeterminate = true, |
| Err(Determined) => { |
| this.update_resolution(parent, target, ns, |_, resolution| { |
| resolution.single_imports.remove(&PtrKey(directive)); |
| }); |
| } |
| Ok(binding) if !binding.is_importable() => { |
| let msg = format!("`{}` is not directly importable", target); |
| struct_span_err!(this.session, directive.span, E0253, "{}", &msg) |
| .span_label(directive.span, "cannot be imported directly") |
| .emit(); |
| // Do not import this illegal binding. Import a dummy binding and pretend |
| // everything is fine |
| this.import_dummy_binding(directive); |
| } |
| Ok(binding) => { |
| let imported_binding = this.import(binding, directive); |
| let conflict = this.try_define(parent, target, ns, imported_binding); |
| if let Err(old_binding) = conflict { |
| this.report_conflict(parent, target, ns, imported_binding, old_binding); |
| } |
| } |
| } |
| }); |
| |
| !indeterminate |
| } |
| |
| // If appropriate, returns an error to report. |
| fn finalize_import(&mut self, directive: &'b ImportDirective<'b>) -> Option<(Span, String)> { |
| self.current_module = directive.parent; |
| let ImportDirective { ref module_path, span, .. } = *directive; |
| let mut warn_if_binding_comes_from_local_crate = false; |
| |
| // FIXME: Last path segment is treated specially in import resolution, so extern crate |
| // mode for absolute paths needs some special support for single-segment imports. |
| if module_path.len() == 1 && (module_path[0].name == keywords::CrateRoot.name() || |
| module_path[0].name == keywords::Extern.name()) { |
| let is_extern = module_path[0].name == keywords::Extern.name() || |
| (self.session.features_untracked().extern_absolute_paths && |
| self.session.rust_2018()); |
| match directive.subclass { |
| GlobImport { .. } if is_extern => { |
| return Some((directive.span, |
| "cannot glob-import all possible crates".to_string())); |
| } |
| GlobImport { .. } if self.session.features_untracked().extern_absolute_paths => { |
| self.lint_path_starts_with_module( |
| directive.root_id, |
| directive.root_span, |
| ); |
| } |
| SingleImport { source, target, .. } => { |
| let crate_root = if source.name == keywords::Crate.name() && |
| module_path[0].name != keywords::Extern.name() { |
| if target.name == keywords::Crate.name() { |
| return Some((directive.span, |
| "crate root imports need to be explicitly named: \ |
| `use crate as name;`".to_string())); |
| } else { |
| Some(self.resolve_crate_root(source)) |
| } |
| } else if is_extern && !source.is_path_segment_keyword() { |
| let crate_id = |
| self.resolver.crate_loader.process_use_extern( |
| source.name, |
| directive.span, |
| directive.id, |
| &self.resolver.definitions, |
| ); |
| let crate_root = |
| self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX }); |
| self.populate_module_if_necessary(crate_root); |
| Some(crate_root) |
| } else { |
| warn_if_binding_comes_from_local_crate = true; |
| None |
| }; |
| |
| if let Some(crate_root) = crate_root { |
| let binding = (crate_root, ty::Visibility::Public, directive.span, |
| directive.expansion).to_name_binding(self.arenas); |
| let binding = self.arenas.alloc_name_binding(NameBinding { |
| kind: NameBindingKind::Import { |
| binding, |
| directive, |
| used: Cell::new(false), |
| }, |
| vis: directive.vis.get(), |
| span: directive.span, |
| expansion: directive.expansion, |
| }); |
| let _ = self.try_define(directive.parent, target, TypeNS, binding); |
| let import = self.import_map.entry(directive.id).or_default(); |
| import[TypeNS] = Some(PathResolution::new(binding.def())); |
| return None; |
| } |
| } |
| _ => {} |
| } |
| } |
| |
| let module_result = self.resolve_path( |
| &module_path, |
| None, |
| true, |
| span, |
| directive.crate_lint(), |
| ); |
| let module = match module_result { |
| PathResult::Module(module) => module, |
| PathResult::Failed(span, msg, false) => { |
| resolve_error(self, span, ResolutionError::FailedToResolve(&msg)); |
| return None; |
| } |
| PathResult::Failed(span, msg, true) => { |
| let (mut self_path, mut self_result) = (module_path.clone(), None); |
| let is_special = |ident: Ident| ident.is_path_segment_keyword() && |
| ident.name != keywords::CrateRoot.name(); |
| if !self_path.is_empty() && !is_special(self_path[0]) && |
| !(self_path.len() > 1 && is_special(self_path[1])) { |
| self_path[0].name = keywords::SelfValue.name(); |
| self_result = Some(self.resolve_path(&self_path, None, false, |
| span, CrateLint::No)); |
| } |
| return if let Some(PathResult::Module(..)) = self_result { |
| Some((span, format!("Did you mean `{}`?", names_to_string(&self_path[..])))) |
| } else { |
| Some((span, msg)) |
| }; |
| }, |
| _ => return None, |
| }; |
| |
| let (ident, result, type_ns_only) = match directive.subclass { |
| SingleImport { source, ref result, type_ns_only, .. } => (source, result, type_ns_only), |
| GlobImport { .. } if module.def_id() == directive.parent.def_id() => { |
| // Importing a module into itself is not allowed. |
| return Some((directive.span, |
| "Cannot glob-import a module into itself.".to_string())); |
| } |
| GlobImport { is_prelude, ref max_vis } => { |
| if !is_prelude && |
| max_vis.get() != ty::Visibility::Invisible && // Allow empty globs. |
| !max_vis.get().is_at_least(directive.vis.get(), &*self) { |
| let msg = "A non-empty glob must import something with the glob's visibility"; |
| self.session.span_err(directive.span, msg); |
| } |
| return None; |
| } |
| _ => unreachable!(), |
| }; |
| |
| let mut all_ns_err = true; |
| self.per_ns(|this, ns| if !type_ns_only || ns == TypeNS { |
| if let Ok(binding) = result[ns].get() { |
| all_ns_err = false; |
| if this.record_use(ident, ns, binding, directive.span) { |
| this.resolution(module, ident, ns).borrow_mut().binding = |
| Some(this.dummy_binding); |
| } |
| } |
| }); |
| |
| if all_ns_err { |
| let mut all_ns_failed = true; |
| self.per_ns(|this, ns| if !type_ns_only || ns == TypeNS { |
| match this.resolve_ident_in_module(module, ident, ns, true, span) { |
| Ok(_) => all_ns_failed = false, |
| _ => {} |
| } |
| }); |
| |
| return if all_ns_failed { |
| let resolutions = module.resolutions.borrow(); |
| let names = resolutions.iter().filter_map(|(&(ref i, _), resolution)| { |
| if *i == ident { return None; } // Never suggest the same name |
| match *resolution.borrow() { |
| NameResolution { binding: Some(name_binding), .. } => { |
| match name_binding.kind { |
| NameBindingKind::Import { binding, .. } => { |
| match binding.kind { |
| // Never suggest the name that has binding error |
| // i.e. the name that cannot be previously resolved |
| NameBindingKind::Def(Def::Err, _) => return None, |
| _ => Some(&i.name), |
| } |
| }, |
| _ => Some(&i.name), |
| } |
| }, |
| NameResolution { ref single_imports, .. } |
| if single_imports.is_empty() => None, |
| _ => Some(&i.name), |
| } |
| }); |
| let lev_suggestion = |
| match find_best_match_for_name(names, &ident.as_str(), None) { |
| Some(name) => format!(". Did you mean to use `{}`?", name), |
| None => "".to_owned(), |
| }; |
| let module_str = module_to_string(module); |
| let msg = if let Some(module_str) = module_str { |
| format!("no `{}` in `{}`{}", ident, module_str, lev_suggestion) |
| } else { |
| format!("no `{}` in the root{}", ident, lev_suggestion) |
| }; |
| Some((span, msg)) |
| } else { |
| // `resolve_ident_in_module` reported a privacy error. |
| self.import_dummy_binding(directive); |
| None |
| } |
| } |
| |
| let mut reexport_error = None; |
| let mut any_successful_reexport = false; |
| self.per_ns(|this, ns| { |
| if let Ok(binding) = result[ns].get() { |
| let vis = directive.vis.get(); |
| if !binding.pseudo_vis().is_at_least(vis, &*this) { |
| reexport_error = Some((ns, binding)); |
| } else { |
| any_successful_reexport = true; |
| } |
| } |
| }); |
| |
| // All namespaces must be re-exported with extra visibility for an error to occur. |
| if !any_successful_reexport { |
| let (ns, binding) = reexport_error.unwrap(); |
| if ns == TypeNS && binding.is_extern_crate() { |
| let msg = format!("extern crate `{}` is private, and cannot be \ |
| re-exported (error E0365), consider declaring with \ |
| `pub`", |
| ident); |
| self.session.buffer_lint(PUB_USE_OF_PRIVATE_EXTERN_CRATE, |
| directive.id, |
| directive.span, |
| &msg); |
| } else if ns == TypeNS { |
| struct_span_err!(self.session, directive.span, E0365, |
| "`{}` is private, and cannot be re-exported", ident) |
| .span_label(directive.span, format!("re-export of private `{}`", ident)) |
| .note(&format!("consider declaring type or module `{}` with `pub`", ident)) |
| .emit(); |
| } else { |
| let msg = format!("`{}` is private, and cannot be re-exported", ident); |
| let note_msg = |
| format!("consider marking `{}` as `pub` in the imported module", ident); |
| struct_span_err!(self.session, directive.span, E0364, "{}", &msg) |
| .span_note(directive.span, ¬e_msg) |
| .emit(); |
| } |
| } |
| |
| if warn_if_binding_comes_from_local_crate { |
| let mut warned = false; |
| self.per_ns(|this, ns| { |
| let binding = match result[ns].get().ok() { |
| Some(b) => b, |
| None => return |
| }; |
| if let NameBindingKind::Import { directive: d, .. } = binding.kind { |
| if let ImportDirectiveSubclass::ExternCrate(..) = d.subclass { |
| return |
| } |
| } |
| if warned { |
| return |
| } |
| warned = true; |
| this.lint_path_starts_with_module( |
| directive.root_id, |
| directive.root_span, |
| ); |
| }); |
| } |
| |
| // Record what this import resolves to for later uses in documentation, |
| // this may resolve to either a value or a type, but for documentation |
| // purposes it's good enough to just favor one over the other. |
| self.per_ns(|this, ns| if let Some(binding) = result[ns].get().ok() { |
| let import = this.import_map.entry(directive.id).or_default(); |
| import[ns] = Some(PathResolution::new(binding.def())); |
| }); |
| |
| debug!("(resolving single import) successfully resolved import"); |
| None |
| } |
| |
| fn resolve_glob_import(&mut self, directive: &'b ImportDirective<'b>) { |
| let module = directive.imported_module.get().unwrap(); |
| self.populate_module_if_necessary(module); |
| |
| if let Some(Def::Trait(_)) = module.def() { |
| self.session.span_err(directive.span, "items in traits are not importable."); |
| return; |
| } else if module.def_id() == directive.parent.def_id() { |
| return; |
| } else if let GlobImport { is_prelude: true, .. } = directive.subclass { |
| self.prelude = Some(module); |
| return; |
| } |
| |
| // Add to module's glob_importers |
| module.glob_importers.borrow_mut().push(directive); |
| |
| // Ensure that `resolutions` isn't borrowed during `try_define`, |
| // since it might get updated via a glob cycle. |
| let bindings = module.resolutions.borrow().iter().filter_map(|(&ident, resolution)| { |
| resolution.borrow().binding().map(|binding| (ident, binding)) |
| }).collect::<Vec<_>>(); |
| for ((mut ident, ns), binding) in bindings { |
| let scope = match ident.span.reverse_glob_adjust(module.expansion, |
| directive.span.ctxt().modern()) { |
| Some(Some(def)) => self.macro_def_scope(def), |
| Some(None) => self.current_module, |
| None => continue, |
| }; |
| if self.is_accessible_from(binding.pseudo_vis(), scope) { |
| let imported_binding = self.import(binding, directive); |
| let _ = self.try_define(directive.parent, ident, ns, imported_binding); |
| } |
| } |
| |
| // Record the destination of this import |
| self.record_def(directive.id, PathResolution::new(module.def().unwrap())); |
| } |
| |
| // Miscellaneous post-processing, including recording re-exports, |
| // reporting conflicts, and reporting unresolved imports. |
| fn finalize_resolutions_in(&mut self, module: Module<'b>) { |
| // Since import resolution is finished, globs will not define any more names. |
| *module.globs.borrow_mut() = Vec::new(); |
| |
| let mut reexports = Vec::new(); |
| let mut exported_macro_names = FxHashMap(); |
| if ptr::eq(module, self.graph_root) { |
| let macro_exports = mem::replace(&mut self.macro_exports, Vec::new()); |
| for export in macro_exports.into_iter().rev() { |
| if let Some(later_span) = exported_macro_names.insert(export.ident.modern(), |
| export.span) { |
| self.session.buffer_lint_with_diagnostic( |
| DUPLICATE_MACRO_EXPORTS, |
| CRATE_NODE_ID, |
| later_span, |
| &format!("a macro named `{}` has already been exported", export.ident), |
| BuiltinLintDiagnostics::DuplicatedMacroExports( |
| export.ident, export.span, later_span)); |
| } else { |
| reexports.push(export); |
| } |
| } |
| } |
| |
| for (&(ident, ns), resolution) in module.resolutions.borrow().iter() { |
| let resolution = &mut *resolution.borrow_mut(); |
| let binding = match resolution.binding { |
| Some(binding) => binding, |
| None => continue, |
| }; |
| |
| if binding.is_import() || binding.is_macro_def() { |
| let def = binding.def(); |
| if def != Def::Err { |
| if !def.def_id().is_local() { |
| self.cstore.export_macros_untracked(def.def_id().krate); |
| } |
| if let Def::Macro(..) = def { |
| if let Some(&span) = exported_macro_names.get(&ident.modern()) { |
| let msg = |
| format!("a macro named `{}` has already been exported", ident); |
| self.session.struct_span_err(span, &msg) |
| .span_label(span, format!("`{}` already exported", ident)) |
| .span_note(binding.span, "previous macro export here") |
| .emit(); |
| } |
| } |
| reexports.push(Export { |
| ident: ident.modern(), |
| def: def, |
| span: binding.span, |
| vis: binding.vis, |
| }); |
| } |
| } |
| |
| match binding.kind { |
| NameBindingKind::Import { binding: orig_binding, directive, .. } => { |
| if ns == TypeNS && orig_binding.is_variant() && |
| !orig_binding.vis.is_at_least(binding.vis, &*self) { |
| let msg = match directive.subclass { |
| ImportDirectiveSubclass::SingleImport { .. } => { |
| format!("variant `{}` is private and cannot be re-exported", |
| ident) |
| }, |
| ImportDirectiveSubclass::GlobImport { .. } => { |
| let msg = "enum is private and its variants \ |
| cannot be re-exported".to_owned(); |
| let error_id = (DiagnosticMessageId::ErrorId(0), // no code?! |
| Some(binding.span), |
| msg.clone()); |
| let fresh = self.session.one_time_diagnostics |
| .borrow_mut().insert(error_id); |
| if !fresh { |
| continue; |
| } |
| msg |
| }, |
| ref s @ _ => bug!("unexpected import subclass {:?}", s) |
| }; |
| let mut err = self.session.struct_span_err(binding.span, &msg); |
| |
| let imported_module = directive.imported_module.get() |
| .expect("module should exist"); |
| let resolutions = imported_module.parent.expect("parent should exist") |
| .resolutions.borrow(); |
| let enum_path_segment_index = directive.module_path.len() - 1; |
| let enum_ident = directive.module_path[enum_path_segment_index]; |
| |
| let enum_resolution = resolutions.get(&(enum_ident, TypeNS)) |
| .expect("resolution should exist"); |
| let enum_span = enum_resolution.borrow() |
| .binding.expect("binding should exist") |
| .span; |
| let enum_def_span = self.session.codemap().def_span(enum_span); |
| let enum_def_snippet = self.session.codemap() |
| .span_to_snippet(enum_def_span).expect("snippet should exist"); |
| // potentially need to strip extant `crate`/`pub(path)` for suggestion |
| let after_vis_index = enum_def_snippet.find("enum") |
| .expect("`enum` keyword should exist in snippet"); |
| let suggestion = format!("pub {}", |
| &enum_def_snippet[after_vis_index..]); |
| |
| self.session |
| .diag_span_suggestion_once(&mut err, |
| DiagnosticMessageId::ErrorId(0), |
| enum_def_span, |
| "consider making the enum public", |
| suggestion); |
| err.emit(); |
| } |
| } |
| _ => {} |
| } |
| } |
| |
| if reexports.len() > 0 { |
| if let Some(def_id) = module.def_id() { |
| self.export_map.insert(def_id, reexports); |
| } |
| } |
| } |
| } |
| |
| fn import_path_to_string(names: &[Ident], |
| subclass: &ImportDirectiveSubclass, |
| span: Span) -> String { |
| let pos = names.iter() |
| .position(|p| span == p.span && p.name != keywords::CrateRoot.name()); |
| let global = !names.is_empty() && names[0].name == keywords::CrateRoot.name(); |
| if let Some(pos) = pos { |
| let names = if global { &names[1..pos + 1] } else { &names[..pos + 1] }; |
| names_to_string(names) |
| } else { |
| let names = if global { &names[1..] } else { names }; |
| if names.is_empty() { |
| import_directive_subclass_to_string(subclass) |
| } else { |
| format!("{}::{}", |
| names_to_string(names), |
| import_directive_subclass_to_string(subclass)) |
| } |
| } |
| } |
| |
| fn import_directive_subclass_to_string(subclass: &ImportDirectiveSubclass) -> String { |
| match *subclass { |
| SingleImport { source, .. } => source.to_string(), |
| GlobImport { .. } => "*".to_string(), |
| ExternCrate(_) => "<extern crate>".to_string(), |
| MacroUse => "#[macro_use]".to_string(), |
| } |
| } |
