| //! A bunch of methods and structures more or less related to resolving imports. | |
| use std::mem; | |
| use rustc_ast::NodeId; | |
| use rustc_data_structures::fx::{FxHashSet, FxIndexSet}; | |
| use rustc_data_structures::intern::Interned; | |
| use rustc_errors::codes::*; | |
| use rustc_errors::{Applicability, Diagnostic, MultiSpan, pluralize, struct_span_code_err}; | |
| use rustc_hir::def::{self, DefKind, PartialRes}; | |
| use rustc_hir::def_id::{DefId, LocalDefIdMap}; | |
| use rustc_middle::metadata::{AmbigModChild, ModChild, Reexport}; | |
| use rustc_middle::span_bug; | |
| use rustc_middle::ty::Visibility; | |
| use rustc_session::lint::builtin::{ | |
| AMBIGUOUS_GLOB_REEXPORTS, EXPORTED_PRIVATE_DEPENDENCIES, HIDDEN_GLOB_REEXPORTS, | |
| PUB_USE_OF_PRIVATE_EXTERN_CRATE, REDUNDANT_IMPORTS, UNUSED_IMPORTS, | |
| }; | |
| use rustc_session::parse::feature_err; | |
| use rustc_span::edit_distance::find_best_match_for_name; | |
| use rustc_span::hygiene::LocalExpnId; | |
| use rustc_span::{Ident, Span, Symbol, kw, sym}; | |
| use tracing::debug; | |
| use crate::Namespace::{self, *}; | |
| use crate::diagnostics::{DiagMode, Suggestion, import_candidates}; | |
| use crate::errors::{ | |
| self, CannotBeReexportedCratePublic, CannotBeReexportedCratePublicNS, | |
| CannotBeReexportedPrivate, CannotBeReexportedPrivateNS, CannotDetermineImportResolution, | |
| CannotGlobImportAllCrates, ConsiderAddingMacroExport, ConsiderMarkingAsPub, | |
| ConsiderMarkingAsPubCrate, | |
| }; | |
| use crate::ref_mut::CmCell; | |
| use crate::{ | |
| AmbiguityError, BindingKey, CmResolver, Decl, DeclData, DeclKind, Determinacy, Finalize, | |
| IdentKey, ImportSuggestion, Module, ModuleOrUniformRoot, ParentScope, PathResult, PerNS, | |
| ResolutionError, Resolver, ScopeSet, Segment, Used, module_to_string, names_to_string, | |
| }; | |
| type Res = def::Res<NodeId>; | |
| /// A potential import declaration in the process of being planted into a module. | |
| /// Also used for lazily planting names from `--extern` flags to extern prelude. | |
| #[derive(Clone, Copy, Default, PartialEq, Debug)] | |
| pub(crate) enum PendingDecl<'ra> { | |
| Ready(Option<Decl<'ra>>), | |
| #[default] | |
| Pending, | |
| } | |
| impl<'ra> PendingDecl<'ra> { | |
| pub(crate) fn decl(self) -> Option<Decl<'ra>> { | |
| match self { | |
| PendingDecl::Ready(decl) => decl, | |
| PendingDecl::Pending => None, | |
| } | |
| } | |
| } | |
| /// Contains data for specific kinds of imports. | |
| #[derive(Clone)] | |
| pub(crate) enum ImportKind<'ra> { | |
| Single { | |
| /// `source` in `use prefix::source as target`. | |
| source: Ident, | |
| /// `target` in `use prefix::source as target`. | |
| /// It will directly use `source` when the format is `use prefix::source`. | |
| target: Ident, | |
| /// Name declarations introduced by the import. | |
| decls: PerNS<CmCell<PendingDecl<'ra>>>, | |
| /// `true` for `...::{self [as target]}` imports, `false` otherwise. | |
| type_ns_only: bool, | |
| /// Did this import result from a nested import? i.e. `use foo::{bar, baz};` | |
| nested: bool, | |
| /// The ID of the `UseTree` that imported this `Import`. | |
| /// | |
| /// In the case where the `Import` was expanded from a "nested" use tree, | |
| /// this id is the ID of the leaf tree. For example: | |
| /// | |
| /// ```ignore (pacify the merciless tidy) | |
| /// use foo::bar::{a, b} | |
| /// ``` | |
| /// | |
| /// If this is the import for `foo::bar::a`, we would have the ID of the `UseTree` | |
| /// for `a` in this field. | |
| id: NodeId, | |
| }, | |
| Glob { | |
| // The visibility of the greatest re-export. | |
| // n.b. `max_vis` is only used in `finalize_import` to check for re-export errors. | |
| max_vis: CmCell<Option<Visibility>>, | |
| id: NodeId, | |
| }, | |
| ExternCrate { | |
| source: Option<Symbol>, | |
| target: Ident, | |
| id: NodeId, | |
| }, | |
| MacroUse { | |
| /// A field has been added indicating whether it should be reported as a lint, | |
| /// addressing issue#119301. | |
| warn_private: bool, | |
| }, | |
| MacroExport, | |
| } | |
| /// Manually implement `Debug` for `ImportKind` because the `source/target_bindings` | |
| /// contain `Cell`s which can introduce infinite loops while printing. | |
| impl<'ra> std::fmt::Debug for ImportKind<'ra> { | |
| fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { | |
| use ImportKind::*; | |
| match self { | |
| Single { source, target, decls, type_ns_only, nested, id, .. } => f | |
| .debug_struct("Single") | |
| .field("source", source) | |
| .field("target", target) | |
| // Ignore the nested bindings to avoid an infinite loop while printing. | |
| .field( | |
| "decls", | |
| &decls.clone().map(|b| b.into_inner().decl().map(|_| format_args!(".."))), | |
| ) | |
| .field("type_ns_only", type_ns_only) | |
| .field("nested", nested) | |
| .field("id", id) | |
| .finish(), | |
| Glob { max_vis, id } => { | |
| f.debug_struct("Glob").field("max_vis", max_vis).field("id", id).finish() | |
| } | |
| ExternCrate { source, target, id } => f | |
| .debug_struct("ExternCrate") | |
| .field("source", source) | |
| .field("target", target) | |
| .field("id", id) | |
| .finish(), | |
| MacroUse { warn_private } => { | |
| f.debug_struct("MacroUse").field("warn_private", warn_private).finish() | |
| } | |
| MacroExport => f.debug_struct("MacroExport").finish(), | |
| } | |
| } | |
| } | |
| /// One import. | |
| #[derive(Debug, Clone)] | |
| pub(crate) struct ImportData<'ra> { | |
| pub kind: ImportKind<'ra>, | |
| /// Node ID of the "root" use item -- this is always the same as `ImportKind`'s `id` | |
| /// (if it exists) 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 | |
| /// ```ignore (incomplete code) | |
| /// use foo::bar::{a, b} | |
| /// ``` | |
| /// this would be the ID of the `use foo::bar` `UseTree` node. | |
| /// In case of imports without their own node ID it's the closest node that can be used, | |
| /// for example, for reporting lints. | |
| pub root_id: NodeId, | |
| /// Span of the entire use statement. | |
| pub use_span: Span, | |
| /// Span of the entire use statement with attributes. | |
| pub use_span_with_attributes: Span, | |
| /// Did the use statement have any attributes? | |
| pub has_attributes: bool, | |
| /// Span of this use tree. | |
| pub span: Span, | |
| /// Span of the *root* use tree (see `root_id`). | |
| pub root_span: Span, | |
| pub parent_scope: ParentScope<'ra>, | |
| pub module_path: Vec<Segment>, | |
| /// The resolution of `module_path`: | |
| /// | |
| /// | `module_path` | `imported_module` | remark | | |
| /// |-|-|-| | |
| /// |`use prefix::foo`| `ModuleOrUniformRoot::Module(prefix)` | - | | |
| /// |`use ::foo` | `ModuleOrUniformRoot::ExternPrelude` | 2018+ editions | | |
| /// |`use ::foo` | `ModuleOrUniformRoot::ModuleAndExternPrelude` | a special case in 2015 edition | | |
| /// |`use foo` | `ModuleOrUniformRoot::CurrentScope` | - | | |
| pub imported_module: CmCell<Option<ModuleOrUniformRoot<'ra>>>, | |
| pub vis: Visibility, | |
| /// Span of the visibility. | |
| pub vis_span: Span, | |
| } | |
| /// All imports are unique and allocated on a same arena, | |
| /// so we can use referential equality to compare them. | |
| pub(crate) type Import<'ra> = Interned<'ra, ImportData<'ra>>; | |
| // Allows us to use Interned without actually enforcing (via Hash/PartialEq/...) uniqueness of the | |
| // contained data. | |
| // FIXME: We may wish to actually have at least debug-level assertions that Interned's guarantees | |
| // are upheld. | |
| impl std::hash::Hash for ImportData<'_> { | |
| fn hash<H>(&self, _: &mut H) | |
| where | |
| H: std::hash::Hasher, | |
| { | |
| unreachable!() | |
| } | |
| } | |
| impl<'ra> ImportData<'ra> { | |
| pub(crate) fn is_glob(&self) -> bool { | |
| matches!(self.kind, ImportKind::Glob { .. }) | |
| } | |
| pub(crate) fn is_nested(&self) -> bool { | |
| match self.kind { | |
| ImportKind::Single { nested, .. } => nested, | |
| _ => false, | |
| } | |
| } | |
| pub(crate) fn id(&self) -> Option<NodeId> { | |
| match self.kind { | |
| ImportKind::Single { id, .. } | |
| | ImportKind::Glob { id, .. } | |
| | ImportKind::ExternCrate { id, .. } => Some(id), | |
| ImportKind::MacroUse { .. } | ImportKind::MacroExport => None, | |
| } | |
| } | |
| pub(crate) fn simplify(&self, r: &Resolver<'_, '_>) -> Reexport { | |
| let to_def_id = |id| r.local_def_id(id).to_def_id(); | |
| match self.kind { | |
| ImportKind::Single { id, .. } => Reexport::Single(to_def_id(id)), | |
| ImportKind::Glob { id, .. } => Reexport::Glob(to_def_id(id)), | |
| ImportKind::ExternCrate { id, .. } => Reexport::ExternCrate(to_def_id(id)), | |
| ImportKind::MacroUse { .. } => Reexport::MacroUse, | |
| ImportKind::MacroExport => Reexport::MacroExport, | |
| } | |
| } | |
| } | |
| /// Records information about the resolution of a name in a namespace of a module. | |
| #[derive(Clone, Debug)] | |
| pub(crate) struct NameResolution<'ra> { | |
| /// Single imports that may define the name in the namespace. | |
| /// Imports are arena-allocated, so it's ok to use pointers as keys. | |
| pub single_imports: FxIndexSet<Import<'ra>>, | |
| /// The non-glob declaration for this name, if it is known to exist. | |
| pub non_glob_decl: Option<Decl<'ra>> = None, | |
| /// The glob declaration for this name, if it is known to exist. | |
| pub glob_decl: Option<Decl<'ra>> = None, | |
| pub orig_ident_span: Span, | |
| } | |
| impl<'ra> NameResolution<'ra> { | |
| pub(crate) fn new(orig_ident_span: Span) -> Self { | |
| NameResolution { single_imports: FxIndexSet::default(), orig_ident_span, .. } | |
| } | |
| /// Returns the binding for the name if it is known or None if it not known. | |
| pub(crate) fn binding(&self) -> Option<Decl<'ra>> { | |
| self.best_decl().and_then(|binding| { | |
| if !binding.is_glob_import() || self.single_imports.is_empty() { | |
| Some(binding) | |
| } else { | |
| None | |
| } | |
| }) | |
| } | |
| pub(crate) fn best_decl(&self) -> Option<Decl<'ra>> { | |
| self.non_glob_decl.or(self.glob_decl) | |
| } | |
| } | |
| /// An error that may be transformed into a diagnostic later. Used to combine multiple unresolved | |
| /// import errors within the same use tree into a single diagnostic. | |
| #[derive(Debug, Clone)] | |
| struct UnresolvedImportError { | |
| span: Span, | |
| label: Option<String>, | |
| note: Option<String>, | |
| suggestion: Option<Suggestion>, | |
| candidates: Option<Vec<ImportSuggestion>>, | |
| segment: Option<Symbol>, | |
| /// comes from `PathRes::Failed { module }` | |
| module: Option<DefId>, | |
| } | |
| // Reexports of the form `pub use foo as bar;` where `foo` is `extern crate foo;` | |
| // are permitted for backward-compatibility under a deprecation lint. | |
| fn pub_use_of_private_extern_crate_hack(import: Import<'_>, decl: Decl<'_>) -> Option<NodeId> { | |
| match (&import.kind, &decl.kind) { | |
| (ImportKind::Single { .. }, DeclKind::Import { import: decl_import, .. }) | |
| if let ImportKind::ExternCrate { id, .. } = decl_import.kind | |
| && import.vis.is_public() => | |
| { | |
| Some(id) | |
| } | |
| _ => None, | |
| } | |
| } | |
| /// Removes identical import layers from two declarations. | |
| fn remove_same_import<'ra>(d1: Decl<'ra>, d2: Decl<'ra>) -> (Decl<'ra>, Decl<'ra>) { | |
| if let DeclKind::Import { import: import1, source_decl: d1_next } = d1.kind | |
| && let DeclKind::Import { import: import2, source_decl: d2_next } = d2.kind | |
| && import1 == import2 | |
| { | |
| assert_eq!(d1.expansion, d2.expansion); | |
| assert_eq!(d1.span, d2.span); | |
| if d1.ambiguity.get() != d2.ambiguity.get() { | |
| assert!(d1.ambiguity.get().is_some()); | |
| assert!(d2.ambiguity.get().is_none()); | |
| } | |
| // Visibility of the new import declaration may be different, | |
| // because it already incorporates the visibility of the source binding. | |
| // `warn_ambiguity` of a re-fetched glob can also change in both directions. | |
| remove_same_import(d1_next, d2_next) | |
| } else { | |
| (d1, d2) | |
| } | |
| } | |
| impl<'ra, 'tcx> Resolver<'ra, 'tcx> { | |
| /// Given an import and the declaration that it points to, | |
| /// create the corresponding import declaration. | |
| pub(crate) fn new_import_decl(&self, decl: Decl<'ra>, import: Import<'ra>) -> Decl<'ra> { | |
| let import_vis = import.vis.to_def_id(); | |
| let vis = if decl.vis().is_at_least(import_vis, self.tcx) | |
| || pub_use_of_private_extern_crate_hack(import, decl).is_some() | |
| { | |
| import_vis | |
| } else { | |
| decl.vis() | |
| }; | |
| if let ImportKind::Glob { ref max_vis, .. } = import.kind | |
| && (vis == import_vis | |
| || max_vis.get().is_none_or(|max_vis| vis.is_at_least(max_vis, self.tcx))) | |
| { | |
| max_vis.set_unchecked(Some(vis.expect_local())) | |
| } | |
| self.arenas.alloc_decl(DeclData { | |
| kind: DeclKind::Import { source_decl: decl, import }, | |
| ambiguity: CmCell::new(None), | |
| warn_ambiguity: CmCell::new(false), | |
| span: import.span, | |
| vis: CmCell::new(vis), | |
| expansion: import.parent_scope.expansion, | |
| parent_module: Some(import.parent_scope.module), | |
| }) | |
| } | |
| /// If `glob_decl` attempts to overwrite `old_glob_decl` in a module, | |
| /// decide which one to keep. | |
| fn select_glob_decl( | |
| &self, | |
| old_glob_decl: Decl<'ra>, | |
| glob_decl: Decl<'ra>, | |
| warn_ambiguity: bool, | |
| ) -> Decl<'ra> { | |
| assert!(glob_decl.is_glob_import()); | |
| assert!(old_glob_decl.is_glob_import()); | |
| assert_ne!(glob_decl, old_glob_decl); | |
| // `best_decl` with a given key in a module may be overwritten in a | |
| // number of cases (all of them can be seen below in the `match` in `try_define_local`), | |
| // all these overwrites will be re-fetched by glob imports importing | |
| // from that module without generating new ambiguities. | |
| // - A glob decl is overwritten by a non-glob decl arriving later. | |
| // - A glob decl is overwritten by its clone after setting ambiguity in it. | |
| // FIXME: avoid this by removing `warn_ambiguity`, or by triggering glob re-fetch | |
| // with the same decl in some way. | |
| // - A glob decl is overwritten by a glob decl with larger visibility. | |
| // FIXME: avoid this by updating this visibility in place. | |
| // - A glob decl is overwritten by a glob decl re-fetching an | |
| // overwritten decl from other module (the recursive case). | |
| // Here we are detecting all such re-fetches and overwrite old decls | |
| // with the re-fetched decls. | |
| // This is probably incorrect in corner cases, and the outdated decls still get | |
| // propagated to other places and get stuck there, but that's what we have at the moment. | |
| let (old_deep_decl, deep_decl) = remove_same_import(old_glob_decl, glob_decl); | |
| if deep_decl != glob_decl { | |
| // Some import layers have been removed, need to overwrite. | |
| assert_ne!(old_deep_decl, old_glob_decl); | |
| // FIXME: reenable the asserts when `warn_ambiguity` is removed (#149195). | |
| // assert_ne!(old_deep_decl, deep_decl); | |
| // assert!(old_deep_decl.is_glob_import()); | |
| // FIXME: reenable the assert when visibility is updated in place. | |
| // assert!(!deep_decl.is_glob_import()); | |
| if old_glob_decl.ambiguity.get().is_some() && glob_decl.ambiguity.get().is_none() { | |
| // Do not lose glob ambiguities when re-fetching the glob. | |
| glob_decl.ambiguity.set_unchecked(old_glob_decl.ambiguity.get()); | |
| } | |
| if glob_decl.is_ambiguity_recursive() { | |
| glob_decl.warn_ambiguity.set_unchecked(true); | |
| } | |
| glob_decl | |
| } else if glob_decl.res() != old_glob_decl.res() { | |
| old_glob_decl.ambiguity.set_unchecked(Some(glob_decl)); | |
| old_glob_decl.warn_ambiguity.set_unchecked(warn_ambiguity); | |
| if warn_ambiguity { | |
| old_glob_decl | |
| } else { | |
| // Need a fresh decl so other glob imports importing it could re-fetch it | |
| // and set their own `warn_ambiguity` to true. | |
| // FIXME: remove this when `warn_ambiguity` is removed (#149195). | |
| self.arenas.alloc_decl((*old_glob_decl).clone()) | |
| } | |
| } else if !old_glob_decl.vis().is_at_least(glob_decl.vis(), self.tcx) { | |
| // We are glob-importing the same item but with greater visibility. | |
| // FIXME: Update visibility in place, but without regressions | |
| // (#152004, #151124, #152347). | |
| glob_decl | |
| } else if glob_decl.is_ambiguity_recursive() && !old_glob_decl.is_ambiguity_recursive() { | |
| // Overwriting a non-ambiguous glob import with an ambiguous glob import. | |
| old_glob_decl.ambiguity.set_unchecked(Some(glob_decl)); | |
| old_glob_decl.warn_ambiguity.set_unchecked(true); | |
| old_glob_decl | |
| } else { | |
| old_glob_decl | |
| } | |
| } | |
| /// Attempt to put the declaration with the given name and namespace into the module, | |
| /// and return existing declaration if there is a collision. | |
| pub(crate) fn try_plant_decl_into_local_module( | |
| &mut self, | |
| ident: IdentKey, | |
| orig_ident_span: Span, | |
| ns: Namespace, | |
| decl: Decl<'ra>, | |
| warn_ambiguity: bool, | |
| ) -> Result<(), Decl<'ra>> { | |
| let module = decl.parent_module.unwrap(); | |
| let res = decl.res(); | |
| self.check_reserved_macro_name(ident.name, orig_ident_span, res); | |
| // Even if underscore names cannot be looked up, we still need to add them to modules, | |
| // because they can be fetched by glob imports from those modules, and bring traits | |
| // into scope both directly and through glob imports. | |
| let key = BindingKey::new_disambiguated(ident, ns, || { | |
| module.underscore_disambiguator.update_unchecked(|d| d + 1); | |
| module.underscore_disambiguator.get() | |
| }); | |
| self.update_local_resolution( | |
| module, | |
| key, | |
| orig_ident_span, | |
| warn_ambiguity, | |
| |this, resolution| { | |
| if let Some(old_decl) = resolution.best_decl() { | |
| assert_ne!(decl, old_decl); | |
| assert!(!decl.warn_ambiguity.get()); | |
| if res == Res::Err && old_decl.res() != Res::Err { | |
| // Do not override real declarations with `Res::Err`s from error recovery. | |
| return Ok(()); | |
| } | |
| match (old_decl.is_glob_import(), decl.is_glob_import()) { | |
| (true, true) => { | |
| resolution.glob_decl = | |
| Some(this.select_glob_decl(old_decl, decl, warn_ambiguity)); | |
| } | |
| (old_glob @ true, false) | (old_glob @ false, true) => { | |
| let (glob_decl, non_glob_decl) = | |
| if old_glob { (old_decl, decl) } else { (decl, old_decl) }; | |
| resolution.non_glob_decl = Some(non_glob_decl); | |
| if let Some(old_glob_decl) = resolution.glob_decl | |
| && old_glob_decl != glob_decl | |
| { | |
| resolution.glob_decl = | |
| Some(this.select_glob_decl(old_glob_decl, glob_decl, false)); | |
| } else { | |
| resolution.glob_decl = Some(glob_decl); | |
| } | |
| } | |
| (false, false) => { | |
| return Err(old_decl); | |
| } | |
| } | |
| } else { | |
| if decl.is_glob_import() { | |
| resolution.glob_decl = Some(decl); | |
| } else { | |
| resolution.non_glob_decl = Some(decl); | |
| } | |
| } | |
| Ok(()) | |
| }, | |
| ) | |
| } | |
| // 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_local_resolution<T, F>( | |
| &mut self, | |
| module: Module<'ra>, | |
| key: BindingKey, | |
| orig_ident_span: Span, | |
| warn_ambiguity: bool, | |
| f: F, | |
| ) -> T | |
| where | |
| F: FnOnce(&Resolver<'ra, 'tcx>, &mut NameResolution<'ra>) -> 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, warn_ambiguity) = { | |
| let resolution = &mut *self | |
| .resolution_or_default(module, key, orig_ident_span) | |
| .borrow_mut_unchecked(); | |
| let old_decl = resolution.binding(); | |
| let t = f(self, resolution); | |
| if let Some(binding) = resolution.binding() | |
| && old_decl != Some(binding) | |
| { | |
| (binding, t, warn_ambiguity || old_decl.is_some()) | |
| } else { | |
| return t; | |
| } | |
| }; | |
| let Ok(glob_importers) = module.glob_importers.try_borrow_mut_unchecked() else { | |
| return t; | |
| }; | |
| // Define or update `binding` in `module`s glob importers. | |
| for import in glob_importers.iter() { | |
| let mut ident = key.ident; | |
| let scope = match ident | |
| .ctxt | |
| .update_unchecked(|ctxt| ctxt.reverse_glob_adjust(module.expansion, import.span)) | |
| { | |
| Some(Some(def)) => self.expn_def_scope(def), | |
| Some(None) => import.parent_scope.module, | |
| None => continue, | |
| }; | |
| if self.is_accessible_from(binding.vis(), scope) { | |
| let import_decl = self.new_import_decl(binding, *import); | |
| let _ = self.try_plant_decl_into_local_module( | |
| ident, | |
| orig_ident_span, | |
| key.ns, | |
| import_decl, | |
| warn_ambiguity, | |
| ); | |
| } | |
| } | |
| t | |
| } | |
| // Define a dummy resolution containing a `Res::Err` as a placeholder for a failed | |
| // or indeterminate resolution, also mark such failed imports as used to avoid duplicate diagnostics. | |
| fn import_dummy_binding(&mut self, import: Import<'ra>, is_indeterminate: bool) { | |
| if let ImportKind::Single { target, ref decls, .. } = import.kind { | |
| if !(is_indeterminate || decls.iter().all(|d| d.get().decl().is_none())) { | |
| return; // Has resolution, do not create the dummy binding | |
| } | |
| let dummy_decl = self.dummy_decl; | |
| let dummy_decl = self.new_import_decl(dummy_decl, import); | |
| self.per_ns(|this, ns| { | |
| let module = import.parent_scope.module; | |
| let ident = IdentKey::new(target); | |
| let _ = this.try_plant_decl_into_local_module( | |
| ident, | |
| target.span, | |
| ns, | |
| dummy_decl, | |
| false, | |
| ); | |
| // Don't remove underscores from `single_imports`, they were never added. | |
| if target.name != kw::Underscore { | |
| let key = BindingKey::new(ident, ns); | |
| this.update_local_resolution( | |
| module, | |
| key, | |
| target.span, | |
| false, | |
| |_, resolution| { | |
| resolution.single_imports.swap_remove(&import); | |
| }, | |
| ) | |
| } | |
| }); | |
| self.record_use(target, dummy_decl, Used::Other); | |
| } else if import.imported_module.get().is_none() { | |
| self.import_use_map.insert(import, Used::Other); | |
| if let Some(id) = import.id() { | |
| self.used_imports.insert(id); | |
| } | |
| } | |
| } | |
| // 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(crate) fn resolve_imports(&mut self) { | |
| let mut prev_indeterminate_count = usize::MAX; | |
| let mut indeterminate_count = self.indeterminate_imports.len() * 3; | |
| while indeterminate_count < prev_indeterminate_count { | |
| prev_indeterminate_count = indeterminate_count; | |
| indeterminate_count = 0; | |
| self.assert_speculative = true; | |
| for import in mem::take(&mut self.indeterminate_imports) { | |
| let import_indeterminate_count = self.cm().resolve_import(import); | |
| indeterminate_count += import_indeterminate_count; | |
| match import_indeterminate_count { | |
| 0 => self.determined_imports.push(import), | |
| _ => self.indeterminate_imports.push(import), | |
| } | |
| } | |
| self.assert_speculative = false; | |
| } | |
| } | |
| pub(crate) fn finalize_imports(&mut self) { | |
| let mut module_children = Default::default(); | |
| let mut ambig_module_children = Default::default(); | |
| for module in &self.local_modules { | |
| self.finalize_resolutions_in(*module, &mut module_children, &mut ambig_module_children); | |
| } | |
| self.module_children = module_children; | |
| self.ambig_module_children = ambig_module_children; | |
| let mut seen_spans = FxHashSet::default(); | |
| let mut errors = vec![]; | |
| let mut prev_root_id: NodeId = NodeId::ZERO; | |
| let determined_imports = mem::take(&mut self.determined_imports); | |
| let indeterminate_imports = mem::take(&mut self.indeterminate_imports); | |
| let mut glob_error = false; | |
| for (is_indeterminate, import) in determined_imports | |
| .iter() | |
| .map(|i| (false, i)) | |
| .chain(indeterminate_imports.iter().map(|i| (true, i))) | |
| { | |
| let unresolved_import_error = self.finalize_import(*import); | |
| // If this import is unresolved then create a dummy import | |
| // resolution for it so that later resolve stages won't complain. | |
| self.import_dummy_binding(*import, is_indeterminate); | |
| let Some(err) = unresolved_import_error else { continue }; | |
| glob_error |= import.is_glob(); | |
| if let ImportKind::Single { source, ref decls, .. } = import.kind | |
| && source.name == kw::SelfLower | |
| // Silence `unresolved import` error if E0429 is already emitted | |
| && let PendingDecl::Ready(None) = decls.value_ns.get() | |
| { | |
| continue; | |
| } | |
| if prev_root_id != NodeId::ZERO && prev_root_id != import.root_id && !errors.is_empty() | |
| { | |
| // In the case of a new import line, throw a diagnostic message | |
| // for the previous line. | |
| self.throw_unresolved_import_error(errors, glob_error); | |
| errors = vec![]; | |
| } | |
| if seen_spans.insert(err.span) { | |
| errors.push((*import, err)); | |
| prev_root_id = import.root_id; | |
| } | |
| } | |
| if !errors.is_empty() { | |
| self.throw_unresolved_import_error(errors, glob_error); | |
| return; | |
| } | |
| for import in &indeterminate_imports { | |
| let path = import_path_to_string( | |
| &import.module_path.iter().map(|seg| seg.ident).collect::<Vec<_>>(), | |
| &import.kind, | |
| import.span, | |
| ); | |
| // FIXME: there should be a better way of doing this than | |
| // formatting this as a string then checking for `::` | |
| if path.contains("::") { | |
| let err = UnresolvedImportError { | |
| span: import.span, | |
| label: None, | |
| note: None, | |
| suggestion: None, | |
| candidates: None, | |
| segment: None, | |
| module: None, | |
| }; | |
| errors.push((*import, err)) | |
| } | |
| } | |
| if !errors.is_empty() { | |
| self.throw_unresolved_import_error(errors, glob_error); | |
| } | |
| } | |
| pub(crate) fn lint_reexports(&mut self, exported_ambiguities: FxHashSet<Decl<'ra>>) { | |
| for module in &self.local_modules { | |
| for (key, resolution) in self.resolutions(*module).borrow().iter() { | |
| let resolution = resolution.borrow(); | |
| let Some(binding) = resolution.best_decl() else { continue }; | |
| if let DeclKind::Import { import, .. } = binding.kind | |
| && let Some(amb_binding) = binding.ambiguity.get() | |
| && binding.res() != Res::Err | |
| && exported_ambiguities.contains(&binding) | |
| { | |
| self.lint_buffer.buffer_lint( | |
| AMBIGUOUS_GLOB_REEXPORTS, | |
| import.root_id, | |
| import.root_span, | |
| errors::AmbiguousGlobReexports { | |
| name: key.ident.name.to_string(), | |
| namespace: key.ns.descr().to_string(), | |
| first_reexport: import.root_span, | |
| duplicate_reexport: amb_binding.span, | |
| }, | |
| ); | |
| } | |
| if let Some(glob_decl) = resolution.glob_decl | |
| && resolution.non_glob_decl.is_some() | |
| { | |
| if binding.res() != Res::Err | |
| && glob_decl.res() != Res::Err | |
| && let DeclKind::Import { import: glob_import, .. } = glob_decl.kind | |
| && let Some(glob_import_id) = glob_import.id() | |
| && let glob_import_def_id = self.local_def_id(glob_import_id) | |
| && self.effective_visibilities.is_exported(glob_import_def_id) | |
| && glob_decl.vis().is_public() | |
| && !binding.vis().is_public() | |
| { | |
| let binding_id = match binding.kind { | |
| DeclKind::Def(res) => { | |
| Some(self.def_id_to_node_id(res.def_id().expect_local())) | |
| } | |
| DeclKind::Import { import, .. } => import.id(), | |
| }; | |
| if let Some(binding_id) = binding_id { | |
| self.lint_buffer.buffer_lint( | |
| HIDDEN_GLOB_REEXPORTS, | |
| binding_id, | |
| binding.span, | |
| errors::HiddenGlobReexports { | |
| name: key.ident.name.to_string(), | |
| namespace: key.ns.descr().to_owned(), | |
| glob_reexport: glob_decl.span, | |
| private_item: binding.span, | |
| }, | |
| ); | |
| } | |
| } | |
| } | |
| if let DeclKind::Import { import, .. } = binding.kind | |
| && let Some(binding_id) = import.id() | |
| && let import_def_id = self.local_def_id(binding_id) | |
| && self.effective_visibilities.is_exported(import_def_id) | |
| && let Res::Def(reexported_kind, reexported_def_id) = binding.res() | |
| && !matches!(reexported_kind, DefKind::Ctor(..)) | |
| && !reexported_def_id.is_local() | |
| && self.tcx.is_private_dep(reexported_def_id.krate) | |
| { | |
| self.lint_buffer.buffer_lint( | |
| EXPORTED_PRIVATE_DEPENDENCIES, | |
| binding_id, | |
| binding.span, | |
| crate::errors::ReexportPrivateDependency { | |
| name: key.ident.name, | |
| kind: binding.res().descr(), | |
| krate: self.tcx.crate_name(reexported_def_id.krate), | |
| }, | |
| ); | |
| } | |
| } | |
| } | |
| } | |
| fn throw_unresolved_import_error( | |
| &mut self, | |
| mut errors: Vec<(Import<'_>, UnresolvedImportError)>, | |
| glob_error: bool, | |
| ) { | |
| errors.retain(|(_import, err)| match err.module { | |
| // Skip `use` errors for `use foo::Bar;` if `foo.rs` has unrecovered parse errors. | |
| Some(def_id) if self.mods_with_parse_errors.contains(&def_id) => false, | |
| // If we've encountered something like `use _;`, we've already emitted an error stating | |
| // that `_` is not a valid identifier, so we ignore that resolve error. | |
| _ => err.segment != Some(kw::Underscore), | |
| }); | |
| if errors.is_empty() { | |
| self.tcx.dcx().delayed_bug("expected a parse or \"`_` can't be an identifier\" error"); | |
| return; | |
| } | |
| let span = MultiSpan::from_spans(errors.iter().map(|(_, err)| err.span).collect()); | |
| let paths = errors | |
| .iter() | |
| .map(|(import, err)| { | |
| let path = import_path_to_string( | |
| &import.module_path.iter().map(|seg| seg.ident).collect::<Vec<_>>(), | |
| &import.kind, | |
| err.span, | |
| ); | |
| format!("`{path}`") | |
| }) | |
| .collect::<Vec<_>>(); | |
| let msg = format!("unresolved import{} {}", pluralize!(paths.len()), paths.join(", "),); | |
| let mut diag = struct_span_code_err!(self.dcx(), span, E0432, "{msg}"); | |
| if let Some((_, UnresolvedImportError { note: Some(note), .. })) = errors.iter().last() { | |
| diag.note(note.clone()); | |
| } | |
| /// Upper limit on the number of `span_label` messages. | |
| const MAX_LABEL_COUNT: usize = 10; | |
| for (import, err) in errors.into_iter().take(MAX_LABEL_COUNT) { | |
| if let Some(label) = err.label { | |
| diag.span_label(err.span, label); | |
| } | |
| if let Some((suggestions, msg, applicability)) = err.suggestion { | |
| if suggestions.is_empty() { | |
| diag.help(msg); | |
| continue; | |
| } | |
| diag.multipart_suggestion(msg, suggestions, applicability); | |
| } | |
| if let Some(candidates) = &err.candidates { | |
| match &import.kind { | |
| ImportKind::Single { nested: false, source, target, .. } => import_candidates( | |
| self.tcx, | |
| &mut diag, | |
| Some(err.span), | |
| candidates, | |
| DiagMode::Import { append: false, unresolved_import: true }, | |
| (source != target) | |
| .then(|| format!(" as {target}")) | |
| .as_deref() | |
| .unwrap_or(""), | |
| ), | |
| ImportKind::Single { nested: true, source, target, .. } => { | |
| import_candidates( | |
| self.tcx, | |
| &mut diag, | |
| None, | |
| candidates, | |
| DiagMode::Normal, | |
| (source != target) | |
| .then(|| format!(" as {target}")) | |
| .as_deref() | |
| .unwrap_or(""), | |
| ); | |
| } | |
| _ => {} | |
| } | |
| } | |
| if matches!(import.kind, ImportKind::Single { .. }) | |
| && let Some(segment) = err.segment | |
| && let Some(module) = err.module | |
| { | |
| self.find_cfg_stripped(&mut diag, &segment, module) | |
| } | |
| } | |
| let guar = diag.emit(); | |
| if glob_error { | |
| self.glob_error = Some(guar); | |
| } | |
| } | |
| /// Attempts to resolve the given import, returning: | |
| /// - `0` means its resolution is determined. | |
| /// - Other values mean that indeterminate exists under certain namespaces. | |
| /// | |
| /// Meanwhile, if resolve successful, the resolved bindings are written | |
| /// into the module. | |
| fn resolve_import<'r>(mut self: CmResolver<'r, 'ra, 'tcx>, import: Import<'ra>) -> usize { | |
| debug!( | |
| "(resolving import for module) resolving import `{}::...` in `{}`", | |
| Segment::names_to_string(&import.module_path), | |
| module_to_string(import.parent_scope.module).unwrap_or_else(|| "???".to_string()), | |
| ); | |
| let module = if let Some(module) = import.imported_module.get() { | |
| module | |
| } else { | |
| let path_res = self.reborrow().maybe_resolve_path( | |
| &import.module_path, | |
| None, | |
| &import.parent_scope, | |
| Some(import), | |
| ); | |
| match path_res { | |
| PathResult::Module(module) => module, | |
| PathResult::Indeterminate => return 3, | |
| PathResult::NonModule(..) | PathResult::Failed { .. } => return 0, | |
| } | |
| }; | |
| import.imported_module.set_unchecked(Some(module)); | |
| let (source, target, bindings, type_ns_only) = match import.kind { | |
| ImportKind::Single { source, target, ref decls, type_ns_only, .. } => { | |
| (source, target, decls, type_ns_only) | |
| } | |
| ImportKind::Glob { .. } => { | |
| self.get_mut_unchecked().resolve_glob_import(import); | |
| return 0; | |
| } | |
| _ => unreachable!(), | |
| }; | |
| let mut indeterminate_count = 0; | |
| self.per_ns_cm(|mut this, ns| { | |
| if !type_ns_only || ns == TypeNS { | |
| if bindings[ns].get() != PendingDecl::Pending { | |
| return; | |
| }; | |
| let binding_result = this.reborrow().maybe_resolve_ident_in_module( | |
| module, | |
| source, | |
| ns, | |
| &import.parent_scope, | |
| Some(import), | |
| ); | |
| let parent = import.parent_scope.module; | |
| let binding = match binding_result { | |
| Ok(binding) => { | |
| if binding.is_assoc_item() | |
| && !this.tcx.features().import_trait_associated_functions() | |
| { | |
| feature_err( | |
| this.tcx.sess, | |
| sym::import_trait_associated_functions, | |
| import.span, | |
| "`use` associated items of traits is unstable", | |
| ) | |
| .emit(); | |
| } | |
| // We need the `target`, `source` can be extracted. | |
| let import_decl = this.new_import_decl(binding, import); | |
| this.get_mut_unchecked().plant_decl_into_local_module( | |
| IdentKey::new(target), | |
| target.span, | |
| ns, | |
| import_decl, | |
| ); | |
| PendingDecl::Ready(Some(import_decl)) | |
| } | |
| Err(Determinacy::Determined) => { | |
| // Don't remove underscores from `single_imports`, they were never added. | |
| if target.name != kw::Underscore { | |
| let key = BindingKey::new(IdentKey::new(target), ns); | |
| this.get_mut_unchecked().update_local_resolution( | |
| parent, | |
| key, | |
| target.span, | |
| false, | |
| |_, resolution| { | |
| resolution.single_imports.swap_remove(&import); | |
| }, | |
| ); | |
| } | |
| PendingDecl::Ready(None) | |
| } | |
| Err(Determinacy::Undetermined) => { | |
| indeterminate_count += 1; | |
| PendingDecl::Pending | |
| } | |
| }; | |
| bindings[ns].set_unchecked(binding); | |
| } | |
| }); | |
| indeterminate_count | |
| } | |
| /// Performs final import resolution, consistency checks and error reporting. | |
| /// | |
| /// Optionally returns an unresolved import error. This error is buffered and used to | |
| /// consolidate multiple unresolved import errors into a single diagnostic. | |
| fn finalize_import(&mut self, import: Import<'ra>) -> Option<UnresolvedImportError> { | |
| let ignore_decl = match &import.kind { | |
| ImportKind::Single { decls, .. } => decls[TypeNS].get().decl(), | |
| _ => None, | |
| }; | |
| let ambiguity_errors_len = |errors: &Vec<AmbiguityError<'_>>| { | |
| errors.iter().filter(|error| error.warning.is_none()).count() | |
| }; | |
| let prev_ambiguity_errors_len = ambiguity_errors_len(&self.ambiguity_errors); | |
| let finalize = Finalize::with_root_span(import.root_id, import.span, import.root_span); | |
| // We'll provide more context to the privacy errors later, up to `len`. | |
| let privacy_errors_len = self.privacy_errors.len(); | |
| let path_res = self.cm().resolve_path( | |
| &import.module_path, | |
| None, | |
| &import.parent_scope, | |
| Some(finalize), | |
| ignore_decl, | |
| Some(import), | |
| ); | |
| let no_ambiguity = | |
| ambiguity_errors_len(&self.ambiguity_errors) == prev_ambiguity_errors_len; | |
| let module = match path_res { | |
| PathResult::Module(module) => { | |
| // Consistency checks, analogous to `finalize_macro_resolutions`. | |
| if let Some(initial_module) = import.imported_module.get() { | |
| if module != initial_module && no_ambiguity && !self.issue_145575_hack_applied { | |
| span_bug!(import.span, "inconsistent resolution for an import"); | |
| } | |
| } else if self.privacy_errors.is_empty() { | |
| self.dcx() | |
| .create_err(CannotDetermineImportResolution { span: import.span }) | |
| .emit(); | |
| } | |
| module | |
| } | |
| PathResult::Failed { | |
| is_error_from_last_segment: false, | |
| span, | |
| segment_name, | |
| label, | |
| suggestion, | |
| module, | |
| error_implied_by_parse_error: _, | |
| message, | |
| } => { | |
| if no_ambiguity { | |
| if !self.issue_145575_hack_applied { | |
| assert!(import.imported_module.get().is_none()); | |
| } | |
| self.report_error( | |
| span, | |
| ResolutionError::FailedToResolve { | |
| segment: segment_name, | |
| label, | |
| suggestion, | |
| module, | |
| message, | |
| }, | |
| ); | |
| } | |
| return None; | |
| } | |
| PathResult::Failed { | |
| is_error_from_last_segment: true, | |
| span, | |
| label, | |
| suggestion, | |
| module, | |
| segment_name, | |
| .. | |
| } => { | |
| if no_ambiguity { | |
| if !self.issue_145575_hack_applied { | |
| assert!(import.imported_module.get().is_none()); | |
| } | |
| let module = if let Some(ModuleOrUniformRoot::Module(m)) = module { | |
| m.opt_def_id() | |
| } else { | |
| None | |
| }; | |
| let err = match self | |
| .make_path_suggestion(import.module_path.clone(), &import.parent_scope) | |
| { | |
| Some((suggestion, note)) => UnresolvedImportError { | |
| span, | |
| label: None, | |
| note, | |
| suggestion: Some(( | |
| vec![(span, Segment::names_to_string(&suggestion))], | |
| String::from("a similar path exists"), | |
| Applicability::MaybeIncorrect, | |
| )), | |
| candidates: None, | |
| segment: Some(segment_name), | |
| module, | |
| }, | |
| None => UnresolvedImportError { | |
| span, | |
| label: Some(label), | |
| note: None, | |
| suggestion, | |
| candidates: None, | |
| segment: Some(segment_name), | |
| module, | |
| }, | |
| }; | |
| return Some(err); | |
| } | |
| return None; | |
| } | |
| PathResult::NonModule(partial_res) => { | |
| if no_ambiguity && partial_res.full_res() != Some(Res::Err) { | |
| // Check if there are no ambiguities and the result is not dummy. | |
| assert!(import.imported_module.get().is_none()); | |
| } | |
| // The error was already reported earlier. | |
| return None; | |
| } | |
| PathResult::Indeterminate => unreachable!(), | |
| }; | |
| let (ident, target, bindings, type_ns_only, import_id) = match import.kind { | |
| ImportKind::Single { source, target, ref decls, type_ns_only, id, .. } => { | |
| (source, target, decls, type_ns_only, id) | |
| } | |
| ImportKind::Glob { ref max_vis, id } => { | |
| if import.module_path.len() <= 1 { | |
| // HACK(eddyb) `lint_if_path_starts_with_module` needs at least | |
| // 2 segments, so the `resolve_path` above won't trigger it. | |
| let mut full_path = import.module_path.clone(); | |
| full_path.push(Segment::from_ident(Ident::dummy())); | |
| self.lint_if_path_starts_with_module(finalize, &full_path, None); | |
| } | |
| if let ModuleOrUniformRoot::Module(module) = module | |
| && module == import.parent_scope.module | |
| { | |
| // Importing a module into itself is not allowed. | |
| return Some(UnresolvedImportError { | |
| span: import.span, | |
| label: Some(String::from("cannot glob-import a module into itself")), | |
| note: None, | |
| suggestion: None, | |
| candidates: None, | |
| segment: None, | |
| module: None, | |
| }); | |
| } | |
| if let Some(max_vis) = max_vis.get() | |
| && !max_vis.is_at_least(import.vis, self.tcx) | |
| { | |
| let def_id = self.local_def_id(id); | |
| self.lint_buffer.buffer_lint( | |
| UNUSED_IMPORTS, | |
| id, | |
| import.span, | |
| crate::errors::RedundantImportVisibility { | |
| span: import.span, | |
| help: (), | |
| max_vis: max_vis.to_string(def_id, self.tcx), | |
| import_vis: import.vis.to_string(def_id, self.tcx), | |
| }, | |
| ); | |
| } | |
| return None; | |
| } | |
| _ => unreachable!(), | |
| }; | |
| if self.privacy_errors.len() != privacy_errors_len { | |
| // Get the Res for the last element, so that we can point to alternative ways of | |
| // importing it if available. | |
| let mut path = import.module_path.clone(); | |
| path.push(Segment::from_ident(ident)); | |
| if let PathResult::Module(ModuleOrUniformRoot::Module(module)) = self.cm().resolve_path( | |
| &path, | |
| None, | |
| &import.parent_scope, | |
| Some(finalize), | |
| ignore_decl, | |
| None, | |
| ) { | |
| let res = module.res().map(|r| (r, ident)); | |
| for error in &mut self.privacy_errors[privacy_errors_len..] { | |
| error.outermost_res = res; | |
| } | |
| } | |
| } | |
| let mut all_ns_err = true; | |
| self.per_ns(|this, ns| { | |
| if !type_ns_only || ns == TypeNS { | |
| let binding = this.cm().resolve_ident_in_module( | |
| module, | |
| ident, | |
| ns, | |
| &import.parent_scope, | |
| Some(Finalize { | |
| report_private: false, | |
| import_vis: Some(import.vis), | |
| ..finalize | |
| }), | |
| bindings[ns].get().decl(), | |
| Some(import), | |
| ); | |
| match binding { | |
| Ok(binding) => { | |
| // Consistency checks, analogous to `finalize_macro_resolutions`. | |
| let initial_res = bindings[ns].get().decl().map(|binding| { | |
| let initial_binding = binding.import_source(); | |
| all_ns_err = false; | |
| if target.name == kw::Underscore | |
| && initial_binding.is_extern_crate() | |
| && !initial_binding.is_import() | |
| { | |
| let used = if import.module_path.is_empty() { | |
| Used::Scope | |
| } else { | |
| Used::Other | |
| }; | |
| this.record_use(ident, binding, used); | |
| } | |
| initial_binding.res() | |
| }); | |
| let res = binding.res(); | |
| let has_ambiguity_error = | |
| this.ambiguity_errors.iter().any(|error| error.warning.is_none()); | |
| if res == Res::Err || has_ambiguity_error { | |
| this.dcx() | |
| .span_delayed_bug(import.span, "some error happened for an import"); | |
| return; | |
| } | |
| if let Some(initial_res) = initial_res { | |
| if res != initial_res && !this.issue_145575_hack_applied { | |
| span_bug!(import.span, "inconsistent resolution for an import"); | |
| } | |
| } else if this.privacy_errors.is_empty() { | |
| this.dcx() | |
| .create_err(CannotDetermineImportResolution { span: import.span }) | |
| .emit(); | |
| } | |
| } | |
| Err(..) => { | |
| // FIXME: This assert may fire if public glob is later shadowed by a private | |
| // single import (see test `issue-55884-2.rs`). In theory single imports should | |
| // always block globs, even if they are not yet resolved, so that this kind of | |
| // self-inconsistent resolution never happens. | |
| // Re-enable the assert when the issue is fixed. | |
| // assert!(result[ns].get().is_err()); | |
| } | |
| } | |
| } | |
| }); | |
| if all_ns_err { | |
| let mut all_ns_failed = true; | |
| self.per_ns(|this, ns| { | |
| if !type_ns_only || ns == TypeNS { | |
| let binding = this.cm().resolve_ident_in_module( | |
| module, | |
| ident, | |
| ns, | |
| &import.parent_scope, | |
| Some(finalize), | |
| None, | |
| None, | |
| ); | |
| if binding.is_ok() { | |
| all_ns_failed = false; | |
| } | |
| } | |
| }); | |
| return if all_ns_failed { | |
| let names = match module { | |
| ModuleOrUniformRoot::Module(module) => { | |
| self.resolutions(module) | |
| .borrow() | |
| .iter() | |
| .filter_map(|(BindingKey { ident: i, .. }, resolution)| { | |
| if i.name == ident.name { | |
| return None; | |
| } // Never suggest the same name | |
| if i.name == kw::Underscore { | |
| return None; | |
| } // `use _` is never valid | |
| let resolution = resolution.borrow(); | |
| if let Some(name_binding) = resolution.best_decl() { | |
| match name_binding.kind { | |
| DeclKind::Import { source_decl, .. } => { | |
| match source_decl.kind { | |
| // Never suggest names that previously could not | |
| // be resolved. | |
| DeclKind::Def(Res::Err) => None, | |
| _ => Some(i.name), | |
| } | |
| } | |
| _ => Some(i.name), | |
| } | |
| } else if resolution.single_imports.is_empty() { | |
| None | |
| } else { | |
| Some(i.name) | |
| } | |
| }) | |
| .collect() | |
| } | |
| _ => Vec::new(), | |
| }; | |
| let lev_suggestion = | |
| find_best_match_for_name(&names, ident.name, None).map(|suggestion| { | |
| ( | |
| vec![(ident.span, suggestion.to_string())], | |
| String::from("a similar name exists in the module"), | |
| Applicability::MaybeIncorrect, | |
| ) | |
| }); | |
| let (suggestion, note) = | |
| match self.check_for_module_export_macro(import, module, ident) { | |
| Some((suggestion, note)) => (suggestion.or(lev_suggestion), note), | |
| _ => (lev_suggestion, None), | |
| }; | |
| let label = match module { | |
| ModuleOrUniformRoot::Module(module) => { | |
| let module_str = module_to_string(module); | |
| if let Some(module_str) = module_str { | |
| format!("no `{ident}` in `{module_str}`") | |
| } else { | |
| format!("no `{ident}` in the root") | |
| } | |
| } | |
| _ => { | |
| if !ident.is_path_segment_keyword() { | |
| format!("no external crate `{ident}`") | |
| } else { | |
| // HACK(eddyb) this shows up for `self` & `super`, which | |
| // should work instead - for now keep the same error message. | |
| format!("no `{ident}` in the root") | |
| } | |
| } | |
| }; | |
| let parent_suggestion = | |
| self.lookup_import_candidates(ident, TypeNS, &import.parent_scope, |_| true); | |
| Some(UnresolvedImportError { | |
| span: import.span, | |
| label: Some(label), | |
| note, | |
| suggestion, | |
| candidates: if !parent_suggestion.is_empty() { | |
| Some(parent_suggestion) | |
| } else { | |
| None | |
| }, | |
| module: import.imported_module.get().and_then(|module| { | |
| if let ModuleOrUniformRoot::Module(m) = module { | |
| m.opt_def_id() | |
| } else { | |
| None | |
| } | |
| }), | |
| segment: Some(ident.name), | |
| }) | |
| } else { | |
| // `resolve_ident_in_module` reported a privacy error. | |
| None | |
| }; | |
| } | |
| let mut reexport_error = None; | |
| let mut any_successful_reexport = false; | |
| let mut crate_private_reexport = false; | |
| self.per_ns(|this, ns| { | |
| let Some(binding) = bindings[ns].get().decl().map(|b| b.import_source()) else { | |
| return; | |
| }; | |
| if !binding.vis().is_at_least(import.vis, this.tcx) { | |
| reexport_error = Some((ns, binding)); | |
| if let Visibility::Restricted(binding_def_id) = binding.vis() | |
| && binding_def_id.is_top_level_module() | |
| { | |
| crate_private_reexport = true; | |
| } | |
| } 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 let Some(extern_crate_id) = pub_use_of_private_extern_crate_hack(import, binding) { | |
| let extern_crate_sp = self.tcx.source_span(self.local_def_id(extern_crate_id)); | |
| self.lint_buffer.buffer_lint( | |
| PUB_USE_OF_PRIVATE_EXTERN_CRATE, | |
| import_id, | |
| import.span, | |
| crate::errors::PrivateExternCrateReexport { | |
| ident, | |
| sugg: extern_crate_sp.shrink_to_lo(), | |
| }, | |
| ); | |
| } else if ns == TypeNS { | |
| let err = if crate_private_reexport { | |
| self.dcx() | |
| .create_err(CannotBeReexportedCratePublicNS { span: import.span, ident }) | |
| } else { | |
| self.dcx().create_err(CannotBeReexportedPrivateNS { span: import.span, ident }) | |
| }; | |
| err.emit(); | |
| } else { | |
| let mut err = if crate_private_reexport { | |
| self.dcx() | |
| .create_err(CannotBeReexportedCratePublic { span: import.span, ident }) | |
| } else { | |
| self.dcx().create_err(CannotBeReexportedPrivate { span: import.span, ident }) | |
| }; | |
| match binding.kind { | |
| DeclKind::Def(Res::Def(DefKind::Macro(_), def_id)) | |
| // exclude decl_macro | |
| if self.get_macro_by_def_id(def_id).macro_rules => | |
| { | |
| err.subdiagnostic( ConsiderAddingMacroExport { | |
| span: binding.span, | |
| }); | |
| err.subdiagnostic( ConsiderMarkingAsPubCrate { | |
| vis_span: import.vis_span, | |
| }); | |
| } | |
| _ => { | |
| err.subdiagnostic( ConsiderMarkingAsPub { | |
| span: import.span, | |
| ident, | |
| }); | |
| } | |
| } | |
| err.emit(); | |
| } | |
| } | |
| if import.module_path.len() <= 1 { | |
| // HACK(eddyb) `lint_if_path_starts_with_module` needs at least | |
| // 2 segments, so the `resolve_path` above won't trigger it. | |
| let mut full_path = import.module_path.clone(); | |
| full_path.push(Segment::from_ident(ident)); | |
| self.per_ns(|this, ns| { | |
| if let Some(binding) = bindings[ns].get().decl().map(|b| b.import_source()) { | |
| this.lint_if_path_starts_with_module(finalize, &full_path, Some(binding)); | |
| } | |
| }); | |
| } | |
| // 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) = bindings[ns].get().decl().map(|b| b.import_source()) { | |
| this.import_res_map.entry(import_id).or_default()[ns] = Some(binding.res()); | |
| } | |
| }); | |
| debug!("(resolving single import) successfully resolved import"); | |
| None | |
| } | |
| pub(crate) fn check_for_redundant_imports(&mut self, import: Import<'ra>) -> bool { | |
| // This function is only called for single imports. | |
| let ImportKind::Single { source, target, ref decls, id, .. } = import.kind else { | |
| unreachable!() | |
| }; | |
| // Skip if the import is of the form `use source as target` and source != target. | |
| if source != target { | |
| return false; | |
| } | |
| // Skip if the import was produced by a macro. | |
| if import.parent_scope.expansion != LocalExpnId::ROOT { | |
| return false; | |
| } | |
| // Skip if we are inside a named module (in contrast to an anonymous | |
| // module defined by a block). | |
| // Skip if the import is public or was used through non scope-based resolution, | |
| // e.g. through a module-relative path. | |
| if self.import_use_map.get(&import) == Some(&Used::Other) | |
| || self.effective_visibilities.is_exported(self.local_def_id(id)) | |
| { | |
| return false; | |
| } | |
| let mut is_redundant = true; | |
| let mut redundant_span = PerNS { value_ns: None, type_ns: None, macro_ns: None }; | |
| self.per_ns(|this, ns| { | |
| let binding = decls[ns].get().decl().map(|b| b.import_source()); | |
| if is_redundant && let Some(binding) = binding { | |
| if binding.res() == Res::Err { | |
| return; | |
| } | |
| match this.cm().resolve_ident_in_scope_set( | |
| target, | |
| ScopeSet::All(ns), | |
| &import.parent_scope, | |
| None, | |
| decls[ns].get().decl(), | |
| None, | |
| ) { | |
| Ok(other_binding) => { | |
| is_redundant = binding.res() == other_binding.res() | |
| && !other_binding.is_ambiguity_recursive(); | |
| if is_redundant { | |
| redundant_span[ns] = | |
| Some((other_binding.span, other_binding.is_import())); | |
| } | |
| } | |
| Err(_) => is_redundant = false, | |
| } | |
| } | |
| }); | |
| if is_redundant && !redundant_span.is_empty() { | |
| let mut redundant_spans: Vec<_> = redundant_span.present_items().collect(); | |
| redundant_spans.sort(); | |
| redundant_spans.dedup(); | |
| self.lint_buffer.dyn_buffer_lint( | |
| REDUNDANT_IMPORTS, | |
| id, | |
| import.span, | |
| move |dcx, level| { | |
| let ident = source; | |
| let subs = redundant_spans | |
| .into_iter() | |
| .map(|(span, is_imported)| match (span.is_dummy(), is_imported) { | |
| (false, true) => { | |
| errors::RedundantImportSub::ImportedHere { span, ident } | |
| } | |
| (false, false) => { | |
| errors::RedundantImportSub::DefinedHere { span, ident } | |
| } | |
| (true, true) => { | |
| errors::RedundantImportSub::ImportedPrelude { span, ident } | |
| } | |
| (true, false) => { | |
| errors::RedundantImportSub::DefinedPrelude { span, ident } | |
| } | |
| }) | |
| .collect(); | |
| errors::RedundantImport { subs, ident }.into_diag(dcx, level) | |
| }, | |
| ); | |
| return true; | |
| } | |
| false | |
| } | |
| fn resolve_glob_import(&mut self, import: Import<'ra>) { | |
| // This function is only called for glob imports. | |
| let ImportKind::Glob { id, .. } = import.kind else { unreachable!() }; | |
| let ModuleOrUniformRoot::Module(module) = import.imported_module.get().unwrap() else { | |
| self.dcx().emit_err(CannotGlobImportAllCrates { span: import.span }); | |
| return; | |
| }; | |
| if module.is_trait() && !self.tcx.features().import_trait_associated_functions() { | |
| feature_err( | |
| self.tcx.sess, | |
| sym::import_trait_associated_functions, | |
| import.span, | |
| "`use` associated items of traits is unstable", | |
| ) | |
| .emit(); | |
| } | |
| if module == import.parent_scope.module { | |
| return; | |
| } | |
| // Add to module's glob_importers | |
| module.glob_importers.borrow_mut_unchecked().push(import); | |
| // Ensure that `resolutions` isn't borrowed during `try_define`, | |
| // since it might get updated via a glob cycle. | |
| let bindings = self | |
| .resolutions(module) | |
| .borrow() | |
| .iter() | |
| .filter_map(|(key, resolution)| { | |
| let resolution = resolution.borrow(); | |
| resolution.binding().map(|binding| (*key, binding, resolution.orig_ident_span)) | |
| }) | |
| .collect::<Vec<_>>(); | |
| for (mut key, binding, orig_ident_span) in bindings { | |
| let scope = | |
| match key.ident.ctxt.update_unchecked(|ctxt| { | |
| ctxt.reverse_glob_adjust(module.expansion, import.span) | |
| }) { | |
| Some(Some(def)) => self.expn_def_scope(def), | |
| Some(None) => import.parent_scope.module, | |
| None => continue, | |
| }; | |
| if self.is_accessible_from(binding.vis(), scope) { | |
| let import_decl = self.new_import_decl(binding, import); | |
| let warn_ambiguity = self | |
| .resolution(import.parent_scope.module, key) | |
| .and_then(|r| r.binding()) | |
| .is_some_and(|binding| binding.warn_ambiguity_recursive()); | |
| let _ = self.try_plant_decl_into_local_module( | |
| key.ident, | |
| orig_ident_span, | |
| key.ns, | |
| import_decl, | |
| warn_ambiguity, | |
| ); | |
| } | |
| } | |
| // Record the destination of this import | |
| self.record_partial_res(id, PartialRes::new(module.res().unwrap())); | |
| } | |
| // Miscellaneous post-processing, including recording re-exports, | |
| // reporting conflicts, and reporting unresolved imports. | |
| fn finalize_resolutions_in( | |
| &self, | |
| module: Module<'ra>, | |
| module_children: &mut LocalDefIdMap<Vec<ModChild>>, | |
| ambig_module_children: &mut LocalDefIdMap<Vec<AmbigModChild>>, | |
| ) { | |
| // Since import resolution is finished, globs will not define any more names. | |
| *module.globs.borrow_mut(self) = Vec::new(); | |
| let Some(def_id) = module.opt_def_id() else { return }; | |
| let mut children = Vec::new(); | |
| let mut ambig_children = Vec::new(); | |
| module.for_each_child(self, |this, ident, orig_ident_span, _, binding| { | |
| let res = binding.res().expect_non_local(); | |
| if res != def::Res::Err { | |
| let ident = ident.orig(orig_ident_span); | |
| let child = | |
| |reexport_chain| ModChild { ident, res, vis: binding.vis(), reexport_chain }; | |
| if let Some((ambig_binding1, ambig_binding2)) = binding.descent_to_ambiguity() { | |
| let main = child(ambig_binding1.reexport_chain(this)); | |
| let second = ModChild { | |
| ident, | |
| res: ambig_binding2.res().expect_non_local(), | |
| vis: ambig_binding2.vis(), | |
| reexport_chain: ambig_binding2.reexport_chain(this), | |
| }; | |
| ambig_children.push(AmbigModChild { main, second }) | |
| } else { | |
| children.push(child(binding.reexport_chain(this))); | |
| } | |
| } | |
| }); | |
| if !children.is_empty() { | |
| module_children.insert(def_id.expect_local(), children); | |
| } | |
| if !ambig_children.is_empty() { | |
| ambig_module_children.insert(def_id.expect_local(), ambig_children); | |
| } | |
| } | |
| } | |
| fn import_path_to_string(names: &[Ident], import_kind: &ImportKind<'_>, span: Span) -> String { | |
| let pos = names.iter().position(|p| span == p.span && p.name != kw::PathRoot); | |
| let global = !names.is_empty() && names[0].name == kw::PathRoot; | |
| if let Some(pos) = pos { | |
| let names = if global { &names[1..pos + 1] } else { &names[..pos + 1] }; | |
| names_to_string(names.iter().map(|ident| ident.name)) | |
| } else { | |
| let names = if global { &names[1..] } else { names }; | |
| if names.is_empty() { | |
| import_kind_to_string(import_kind) | |
| } else { | |
| format!( | |
| "{}::{}", | |
| names_to_string(names.iter().map(|ident| ident.name)), | |
| import_kind_to_string(import_kind), | |
| ) | |
| } | |
| } | |
| } | |
| fn import_kind_to_string(import_kind: &ImportKind<'_>) -> String { | |
| match import_kind { | |
| ImportKind::Single { source, .. } => source.to_string(), | |
| ImportKind::Glob { .. } => "*".to_string(), | |
| ImportKind::ExternCrate { .. } => "<extern crate>".to_string(), | |
| ImportKind::MacroUse { .. } => "#[macro_use]".to_string(), | |
| ImportKind::MacroExport => "#[macro_export]".to_string(), | |
| } | |
| } |