1//! A bunch of methods and structures more or less related to resolving imports.23use std::cmp::Ordering;4use std::mem;56use rustc_ast::NodeId;7use rustc_data_structures::fx::{FxHashSet, FxIndexSet};8use rustc_data_structures::intern::Interned;9use rustc_errors::{Applicability, BufferedEarlyLint, Diagnostic};10use rustc_expand::base::SyntaxExtensionKind;11use rustc_hir::def::{self, DefKind, PartialRes};12use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdMap};13use rustc_middle::metadata::{AmbigModChild, ModChild, Reexport};14use rustc_middle::span_bug;15use rustc_middle::ty::Visibility;16use rustc_session::errors::feature_err;17use rustc_session::lint::LintId;18use rustc_session::lint::builtin::{19 AMBIGUOUS_GLOB_REEXPORTS, EXPORTED_PRIVATE_DEPENDENCIES, HIDDEN_GLOB_REEXPORTS,20 PUB_USE_OF_PRIVATE_EXTERN_CRATE, REDUNDANT_IMPORTS, UNUSED_IMPORTS,21};22use rustc_span::edit_distance::find_best_match_for_name;23use rustc_span::hygiene::LocalExpnId;24use rustc_span::{Ident, Span, Symbol, kw, sym};25use tracing::debug;2627use crate::Namespace::{self, *};28use crate::diagnostics::{29 self, CannotBeReexportedCratePublic, CannotBeReexportedCratePublicNS,30 CannotBeReexportedPrivate, CannotBeReexportedPrivateNS, CannotDetermineImportResolution,31 CannotGlobImportAllCrates, ConsiderAddingMacroExport, ConsiderMarkingAsPub,32 ConsiderMarkingAsPubCrate,33};34use crate::error_helper::{OnUnknownData, Suggestion};35use crate::ref_mut::CmCell;36use crate::{37 AmbiguityError, BindingKey, CmResolver, Decl, DeclData, DeclKind, Determinacy, Finalize,38 IdentKey, ImportSuggestion, ImportSummary, LocalModule, ModuleOrUniformRoot, ParentScope,39 PathResult, PerNS, Res, ResolutionError, Resolver, ScopeSet, Segment, Used, module_to_string,40 names_to_string,41};4243/// A potential import declaration in the process of being planted into a module.44/// Also used for lazily planting names from `--extern` flags to extern prelude.45#[derive(Clone, Copy, Default, PartialEq, Debug)]46pub(crate) enum PendingDecl<'ra> {47 Ready(Option<Decl<'ra>>),48 #[default]49 Pending,50}5152enum ImportResolutionKind<'ra> {53 Single(PerNS<PendingDecl<'ra>>),54 Glob(Vec<(Decl<'ra>, BindingKey, Span /* orig_ident_span */)>),55}5657struct ImportResolution<'ra> {58 kind: ImportResolutionKind<'ra>,59 imported_module: ModuleOrUniformRoot<'ra>,60}6162impl<'ra> PendingDecl<'ra> {63 pub(crate) fn decl(self) -> Option<Decl<'ra>> {64 match self {65 PendingDecl::Ready(decl) => decl,66 PendingDecl::Pending => None,67 }68 }69}7071/// Contains data for specific kinds of imports.72#[derive(Clone)]73pub(crate) enum ImportKind<'ra> {74 Single {75 /// `source` in `use prefix::source as target`.76 source: Ident,77 /// `target` in `use prefix::source as target`.78 /// It will directly use `source` when the format is `use prefix::source`.79 target: Ident,80 /// Name declarations introduced by the import.81 decls: PerNS<CmCell<PendingDecl<'ra>>>,82 /// Did this import result from a nested import? i.e. `use foo::{bar, baz};`83 nested: bool,84 /// The ID of the `UseTree` that imported this `Import`.85 ///86 /// In the case where the `Import` was expanded from a "nested" use tree,87 /// this id is the ID of the leaf tree. For example:88 ///89 /// ```ignore (pacify the merciless tidy)90 /// use foo::bar::{a, b}91 /// ```92 ///93 /// If this is the import for `foo::bar::a`, we would have the ID of the `UseTree`94 /// for `a` in this field.95 id: NodeId,96 def_id: LocalDefId,97 },98 Glob {99 // The visibility of the greatest re-export.100 // n.b. `max_vis` is only used in `finalize_import` to check for re-export errors.101 max_vis: CmCell<Option<Visibility>>,102 id: NodeId,103 def_id: LocalDefId,104 },105 ExternCrate {106 source: Option<Symbol>,107 target: Ident,108 id: NodeId,109 def_id: LocalDefId,110 },111 MacroUse {112 /// A field has been added indicating whether it should be reported as a lint,113 /// addressing issue#119301.114 warn_private: bool,115 },116 MacroExport,117}118119/// Manually implement `Debug` for `ImportKind` because the `source/target_bindings`120/// contain `Cell`s which can introduce infinite loops while printing.121impl<'ra> std::fmt::Debug for ImportKind<'ra> {122 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {123 use ImportKind::*;124 match self {125 Single { source, target, decls, nested, id, def_id } => f126 .debug_struct("Single")127 .field("source", source)128 .field("target", target)129 // Ignore the nested bindings to avoid an infinite loop while printing.130 .field(131 "decls",132 &decls.clone().map(|b| b.into_inner().decl().map(|_| format_args!(".."))),133 )134 .field("nested", nested)135 .field("id", id)136 .field("def_id", def_id)137 .finish(),138 Glob { max_vis, id, def_id } => f139 .debug_struct("Glob")140 .field("max_vis", max_vis)141 .field("id", id)142 .field("def_id", def_id)143 .finish(),144 ExternCrate { source, target, id, def_id } => f145 .debug_struct("ExternCrate")146 .field("source", source)147 .field("target", target)148 .field("id", id)149 .field("def_id", def_id)150 .finish(),151 MacroUse { warn_private } => {152 f.debug_struct("MacroUse").field("warn_private", warn_private).finish()153 }154 MacroExport => f.debug_struct("MacroExport").finish(),155 }156 }157}158159/// One import.160#[derive(Debug, Clone)]161pub(crate) struct ImportData<'ra> {162 pub kind: ImportKind<'ra>,163164 /// Node ID of the "root" use item -- this is always the same as `ImportKind`'s `id`165 /// (if it exists) except in the case of "nested" use trees, in which case166 /// it will be the ID of the root use tree. e.g., in the example167 /// ```ignore (incomplete code)168 /// use foo::bar::{a, b}169 /// ```170 /// this would be the ID of the `use foo::bar` `UseTree` node.171 /// In case of imports without their own node ID it's the closest node that can be used,172 /// for example, for reporting lints.173 pub root_id: NodeId,174175 /// Span of the entire use statement.176 pub use_span: Span,177178 /// Span of the entire use statement with attributes.179 pub use_span_with_attributes: Span,180181 /// Did the use statement have any attributes?182 pub has_attributes: bool,183184 /// Span of this use tree.185 pub span: Span,186187 /// Span of the *root* use tree (see `root_id`).188 pub root_span: Span,189190 pub parent_scope: ParentScope<'ra>,191 pub module_path: Vec<Segment>,192 /// The resolution of `module_path`:193 ///194 /// | `module_path` | `imported_module` | remark |195 /// |-|-|-|196 /// |`use prefix::foo`| `ModuleOrUniformRoot::Module(prefix)` | - |197 /// |`use ::foo` | `ModuleOrUniformRoot::ExternPrelude` | 2018+ editions |198 /// |`use ::foo` | `ModuleOrUniformRoot::ModuleAndExternPrelude` | a special case in 2015 edition |199 /// |`use foo` | `ModuleOrUniformRoot::CurrentScope` | - |200 pub imported_module: CmCell<Option<ModuleOrUniformRoot<'ra>>>,201 pub vis: Visibility,202203 /// Span of the visibility.204 pub vis_span: Span,205206 /// A `#[diagnostic::on_unknown]` attribute applied207 /// to the given import. This allows crates to specify208 /// custom error messages for a specific import209 ///210 /// This is `None` if the feature flag for `diagnostic::on_unknown` is disabled.211 pub on_unknown_attr: Option<OnUnknownData>,212}213214/// All imports are unique and allocated on a same arena,215/// so we can use referential equality to compare them.216pub(crate) type Import<'ra> = Interned<'ra, ImportData<'ra>>;217218// Allows us to use Interned without actually enforcing (via Hash/PartialEq/...) uniqueness of the219// contained data.220// FIXME: We may wish to actually have at least debug-level assertions that Interned's guarantees221// are upheld.222impl std::hash::Hash for ImportData<'_> {223 fn hash<H>(&self, _: &mut H)224 where225 H: std::hash::Hasher,226 {227 unreachable!()228 }229}230231impl<'ra> ImportData<'ra> {232 pub(crate) fn is_glob(&self) -> bool {233 matches!(self.kind, ImportKind::Glob { .. })234 }235236 pub(crate) fn is_nested(&self) -> bool {237 match self.kind {238 ImportKind::Single { nested, .. } => nested,239 _ => false,240 }241 }242243 pub(crate) fn id(&self) -> Option<NodeId> {244 match self.kind {245 ImportKind::Single { id, .. }246 | ImportKind::Glob { id, .. }247 | ImportKind::ExternCrate { id, .. } => Some(id),248 ImportKind::MacroUse { .. } | ImportKind::MacroExport => None,249 }250 }251252 pub(crate) fn def_id(&self) -> Option<LocalDefId> {253 match self.kind {254 ImportKind::Single { def_id, .. }255 | ImportKind::Glob { def_id, .. }256 | ImportKind::ExternCrate { def_id, .. } => Some(def_id),257 ImportKind::MacroUse { .. } | ImportKind::MacroExport => None,258 }259 }260261 pub(crate) fn simplify(&self) -> Reexport {262 match self.kind {263 ImportKind::Single { def_id, .. } => Reexport::Single(def_id.to_def_id()),264 ImportKind::Glob { def_id, .. } => Reexport::Glob(def_id.to_def_id()),265 ImportKind::ExternCrate { def_id, .. } => Reexport::ExternCrate(def_id.to_def_id()),266 ImportKind::MacroUse { .. } => Reexport::MacroUse,267 ImportKind::MacroExport => Reexport::MacroExport,268 }269 }270271 fn summary(&self) -> ImportSummary {272 ImportSummary {273 vis: self.vis,274 nearest_parent_mod: self.parent_scope.module.nearest_parent_mod().expect_local(),275 is_single: matches!(self.kind, ImportKind::Single { .. }),276 priv_macro_use: matches!(self.kind, ImportKind::MacroUse { warn_private: true }),277 span: self.span,278 }279 }280}281282/// Records information about the resolution of a name in a namespace of a module.283#[derive(Clone, Debug)]284pub(crate) struct NameResolution<'ra> {285 /// Single imports that may define the name in the namespace.286 /// Imports are arena-allocated, so it's ok to use pointers as keys.287 pub single_imports: FxIndexSet<Import<'ra>>,288 /// The non-glob declaration for this name, if it is known to exist.289 pub non_glob_decl: Option<Decl<'ra>> = None,290 /// The glob declaration for this name, if it is known to exist.291 pub glob_decl: Option<Decl<'ra>> = None,292 pub orig_ident_span: Span,293}294295impl<'ra> NameResolution<'ra> {296 pub(crate) fn new(orig_ident_span: Span) -> Self {297 NameResolution { single_imports: FxIndexSet::default(), orig_ident_span, .. }298 }299300 /// Returns the best declaration if it is not going to change, and `None` if the best301 /// declaration may still change to something else.302 /// FIXME: this function considers `single_imports`, but not `unexpanded_invocations`, so303 /// the returned declaration may actually change after expanding macros in the same module,304 /// because of this fact we have glob overwriting (`select_glob_decl`). Consider using305 /// `unexpanded_invocations` here and avoiding glob overwriting entirely, if it doesn't cause306 /// code breakage in practice.307 /// FIXME: relationship between this function and similar `DeclData::determined` is unclear.308 pub(crate) fn determined_decl(&self) -> Option<Decl<'ra>> {309 if self.non_glob_decl.is_some() {310 self.non_glob_decl311 } else if self.glob_decl.is_some() && self.single_imports.is_empty() {312 self.glob_decl313 } else {314 None315 }316 }317318 pub(crate) fn best_decl(&self) -> Option<Decl<'ra>> {319 self.non_glob_decl.or(self.glob_decl)320 }321}322323/// An error that may be transformed into a diagnostic later. Used to combine multiple unresolved324/// import errors within the same use tree into a single diagnostic.325#[derive(Debug, Clone)]326pub(crate) struct UnresolvedImportError {327 pub(crate) span: Span,328 pub(crate) label: Option<String>,329 pub(crate) note: Option<String>,330 pub(crate) suggestion: Option<Suggestion>,331 pub(crate) candidates: Option<Vec<ImportSuggestion>>,332 pub(crate) segment: Option<Ident>,333 /// comes from `PathRes::Failed { module }`334 pub(crate) module: Option<DefId>,335 pub(crate) on_unknown_attr: Option<OnUnknownData>,336}337338// Reexports of the form `pub use foo as bar;` where `foo` is `extern crate foo;`339// are permitted for backward-compatibility under a deprecation lint.340fn pub_use_of_private_extern_crate_hack(341 import: ImportSummary,342 decl: Decl<'_>,343) -> Option<LocalDefId> {344 match (import.is_single, decl.kind) {345 (true, DeclKind::Import { import: decl_import, .. })346 if let ImportKind::ExternCrate { def_id, .. } = decl_import.kind347 && import.vis.is_public() =>348 {349 Some(def_id)350 }351 _ => None,352 }353}354355/// Removes identical import layers from two declarations.356fn remove_same_import<'ra>(d1: Decl<'ra>, d2: Decl<'ra>) -> (Decl<'ra>, Decl<'ra>) {357 if let DeclKind::Import { import: import1, source_decl: d1_next } = d1.kind358 && let DeclKind::Import { import: import2, source_decl: d2_next } = d2.kind359 && import1 == import2360 {361 assert_eq!(d1.expansion, d2.expansion);362 assert_eq!(d1.span, d2.span);363 if d1.ambiguity.get() != d2.ambiguity.get() {364 assert!(d1.ambiguity.get().is_some());365 }366 // Visibility of the new import declaration may be different,367 // because it already incorporates the visibility of the source binding.368 remove_same_import(d1_next, d2_next)369 } else {370 (d1, d2)371 }372}373374impl<'ra, 'tcx> Resolver<'ra, 'tcx> {375 pub(crate) fn import_decl_vis(&self, decl: Decl<'ra>, import: ImportSummary) -> Visibility {376 self.import_decl_vis_ext(decl, import, false)377 }378379 pub(crate) fn import_decl_vis_ext(380 &self,381 decl: Decl<'ra>,382 import: ImportSummary,383 min: bool,384 ) -> Visibility {385 assert!(import.vis.is_accessible_from(import.nearest_parent_mod, self.tcx));386 let decl_vis = if min { decl.min_vis() } else { decl.vis() };387 let ord = decl_vis.partial_cmp(import.vis, self.tcx);388 let extern_crate_hack = pub_use_of_private_extern_crate_hack(import, decl).is_some();389 if ord == Some(Ordering::Less)390 && decl_vis.is_accessible_from(import.nearest_parent_mod, self.tcx)391 && !extern_crate_hack392 {393 // Imported declaration is less visible than the import, but is still visible394 // from the current module, use the declaration's visibility.395 decl_vis.expect_local()396 } else {397 // Good case - imported declaration is more visible than the import, or the same,398 // use the import's visibility.399 //400 // Bad case - imported declaration is too private for the current module.401 // It doesn't matter what visibility we choose here (except in the `PRIVATE_MACRO_USE`402 // and `PUB_USE_OF_PRIVATE_EXTERN_CRATE` cases), because an error will be reported.403 // Use import visibility to keep the all declaration visibilities in a module ordered.404 if !min405 && matches!(ord, None | Some(Ordering::Less))406 && !extern_crate_hack407 && !import.priv_macro_use408 {409 let msg = format!("cannot extend visibility from {decl_vis:?} to {:?}", import.vis);410 self.dcx().span_delayed_bug(import.span, msg);411 }412 import.vis413 }414 }415416 /// Given an import and the declaration that it points to,417 /// create the corresponding import declaration.418 pub(crate) fn new_import_decl(&self, decl: Decl<'ra>, import: Import<'ra>) -> Decl<'ra> {419 let vis = self.import_decl_vis(decl, import.summary());420421 if let ImportKind::Glob { ref max_vis, .. } = import.kind422 && (vis == import.vis423 || max_vis.get().is_none_or(|max_vis| vis.greater_than(max_vis, self.tcx)))424 {425 // `set` can't fail because this can only happen during "write_import_resolutions"426 max_vis.set(Some(vis), self)427 }428429 self.arenas.alloc_decl(DeclData {430 kind: DeclKind::Import { source_decl: decl, import },431 ambiguity: CmCell::new(None),432 span: import.span,433 initial_vis: vis.to_def_id(),434 ambiguity_vis_max: CmCell::new(None),435 ambiguity_vis_min: CmCell::new(None),436 expansion: import.parent_scope.expansion,437 parent_module: Some(import.parent_scope.module),438 })439 }440441 fn is_noise_0_7_0(&self, old_glob_decl: Decl<'ra>, glob_decl: Decl<'ra>) -> bool {442 let DeclKind::Import { import: i1, .. } = glob_decl.kind else { unreachable!() };443 let DeclKind::Import { import: i2, .. } = old_glob_decl.kind else { unreachable!() };444 let [seg1, seg2] = &i1.module_path[..] else { return false };445 if seg1.ident.name != kw::SelfLower || seg2.ident.name.as_str() != "perlin_surflet" {446 return false;447 }448 let [seg1, seg2] = &i2.module_path[..] else { return false };449 if seg1.ident.name != kw::SelfLower || seg2.ident.name.as_str() != "perlin" {450 return false;451 }452 let Some(def_id1) = glob_decl.res().opt_def_id() else { return false };453 let Some(def_id2) = old_glob_decl.res().opt_def_id() else { return false };454 self.def_path_str(def_id1).ends_with("noise_fns::generators::perlin_surflet::Perlin")455 && self.def_path_str(def_id2).ends_with("noise_fns::generators::perlin::Perlin")456 }457458 fn is_rustybuzz_0_4_0(&self, old_glob_decl: Decl<'ra>, glob_decl: Decl<'ra>) -> bool {459 let DeclKind::Import { import: i1, .. } = glob_decl.kind else { unreachable!() };460 let DeclKind::Import { import: i2, .. } = old_glob_decl.kind else { unreachable!() };461 let [seg1, seg2] = &i1.module_path[..] else { return false };462 if seg1.ident.name != kw::Super || seg2.ident.name.as_str() != "gsubgpos" {463 return false;464 }465 let [seg1] = &i2.module_path[..] else { return false };466 if seg1.ident.name != kw::Super {467 return false;468 }469 let Some(def_id1) = glob_decl.res().opt_def_id() else { return false };470 let Some(def_id2) = old_glob_decl.res().opt_def_id() else { return false };471 self.def_path_str(def_id1).ends_with("tables::gsubgpos::Class")472 && self.def_path_str(def_id2).ends_with("ggg::Class")473 }474475 fn is_pdf_0_9_0(&self, old_glob_decl: Decl<'ra>, glob_decl: Decl<'ra>) -> bool {476 let DeclKind::Import { import: i1, .. } = glob_decl.kind else { unreachable!() };477 let DeclKind::Import { import: i2, .. } = old_glob_decl.kind else { unreachable!() };478 let [seg1, seg2] = &i1.module_path[..] else { return false };479 if seg1.ident.name != kw::Crate || seg2.ident.name.as_str() != "content" {480 return false;481 }482 let [seg1, seg2] = &i2.module_path[..] else { return false };483 if seg1.ident.name != kw::Crate || seg2.ident.name.as_str() != "object" {484 return false;485 }486 let Some(def_id1) = glob_decl.res().opt_def_id() else { return false };487 let Some(def_id2) = old_glob_decl.res().opt_def_id() else { return false };488 self.def_path_str(def_id1).ends_with("crate::content::Rect")489 && self.def_path_str(def_id2).ends_with("crate::object::types::Rect")490 }491492 fn is_net2_0_2_39(&self, old_glob_decl: Decl<'ra>, glob_decl: Decl<'ra>) -> bool {493 let DeclKind::Import { import: i1, .. } = glob_decl.kind else { unreachable!() };494 let DeclKind::Import { import: i2, .. } = old_glob_decl.kind else { unreachable!() };495 let [seg1, seg2, seg3, seg4] = &i1.module_path[..] else { return false };496 if seg1.ident.name != kw::PathRoot497 || seg2.ident.name.as_str() != "winapi"498 || seg3.ident.name.as_str() != "shared"499 || seg4.ident.name.as_str() != "ws2def"500 {501 return false;502 }503 let [seg1, seg2, seg3, seg4] = &i2.module_path[..] else { return false };504 if seg1.ident.name != kw::PathRoot505 || seg2.ident.name.as_str() != "winapi"506 || seg3.ident.name.as_str() != "um"507 || seg4.ident.name.as_str() != "winsock2"508 {509 return false;510 }511 let Some(def_id1) = glob_decl.res().opt_def_id() else { return false };512 let Some(def_id2) = old_glob_decl.res().opt_def_id() else { return false };513 self.def_path_str(def_id1).starts_with("winapi::shared::ws2def::")514 && self.def_path_str(def_id2).starts_with("winapi::um::winsock2::")515 }516517 /// If `glob_decl` attempts to overwrite `old_glob_decl` in a module,518 /// decide which one to keep.519 fn select_glob_decl(&self, old_glob_decl: Decl<'ra>, glob_decl: Decl<'ra>) -> Decl<'ra> {520 assert!(glob_decl.is_glob_import());521 assert!(old_glob_decl.is_glob_import());522 assert_ne!(glob_decl, old_glob_decl);523 // `best_decl` with a given key in a module may be overwritten in a524 // number of cases (all of them can be seen below in the `match` in `try_define_local`),525 // all these overwrites will be re-fetched by glob imports importing526 // from that module without generating new ambiguities.527 // - A glob decl is overwritten by a non-glob decl arriving later.528 // - A glob decl is overwritten by a glob decl re-fetching an529 // overwritten decl from other module (the recursive case).530 // Here we are detecting all such re-fetches and overwrite old decls531 // with the re-fetched decls.532 // This is probably incorrect in corner cases, and the outdated decls still get533 // propagated to other places and get stuck there, but that's what we have at the moment.534 let (old_deep_decl, deep_decl) = remove_same_import(old_glob_decl, glob_decl);535 if deep_decl != glob_decl {536 // Some import layers have been removed, need to overwrite.537 assert_ne!(old_deep_decl, old_glob_decl);538 assert!(!deep_decl.is_glob_import());539 if let Some((old_ambig, _)) = old_glob_decl.ambiguity.get()540 && glob_decl.ambiguity.get().is_none()541 {542 // Do not lose glob ambiguities when re-fetching the glob.543 glob_decl.ambiguity.set(Some((old_ambig, true)), self);544 }545 glob_decl546 } else if glob_decl.res() != old_glob_decl.res() {547 let warning = self.is_noise_0_7_0(old_glob_decl, glob_decl)548 || self.is_rustybuzz_0_4_0(old_glob_decl, glob_decl)549 || self.is_pdf_0_9_0(old_glob_decl, glob_decl)550 || self.is_net2_0_2_39(old_glob_decl, glob_decl);551 old_glob_decl.ambiguity.set(Some((glob_decl, warning)), self);552 old_glob_decl553 } else if let old_vis = old_glob_decl.vis()554 && let vis = glob_decl.vis()555 && old_vis != vis556 {557 // We are glob-importing the same item but with a different visibility.558 // All visibilities here are ordered because all of them are ancestors of `module`.559 if vis.greater_than(old_vis, self.tcx) {560 old_glob_decl.ambiguity_vis_max.set(Some(glob_decl), self);561 } else if let old_min_vis = old_glob_decl.min_vis()562 && old_min_vis != vis563 && old_min_vis.greater_than(vis, self.tcx)564 {565 old_glob_decl.ambiguity_vis_min.set(Some(glob_decl), self);566 }567 old_glob_decl568 } else if glob_decl.is_ambiguity_recursive() && !old_glob_decl.is_ambiguity_recursive() {569 // Overwriting a non-ambiguous glob import with an ambiguous glob import.570 old_glob_decl.ambiguity.set(Some((glob_decl, true)), self);571 old_glob_decl572 } else {573 old_glob_decl574 }575 }576577 /// Attempt to put the declaration with the given name and namespace into the module,578 /// and return existing declaration if there is a collision.579 pub(crate) fn try_plant_decl_into_local_module(580 &mut self,581 ident: IdentKey,582 orig_ident_span: Span,583 ns: Namespace,584 decl: Decl<'ra>,585 ) -> Result<(), Decl<'ra>> {586 assert!(decl.ambiguity.get().is_none());587 assert!(decl.ambiguity_vis_max.get().is_none());588 assert!(decl.ambiguity_vis_min.get().is_none());589 let module = decl.parent_module.unwrap().expect_local();590 assert!(self.is_accessible_from(decl.vis(), module.to_module()));591 let res = decl.res();592 self.check_reserved_macro_name(ident.name, orig_ident_span, res);593 // Even if underscore names cannot be looked up, we still need to add them to modules,594 // because they can be fetched by glob imports from those modules, and bring traits595 // into scope both directly and through glob imports.596 let key = BindingKey::new_disambiguated(ident, ns, || {597 module.underscore_disambiguator.update(self, |d| d + 1);598 module.underscore_disambiguator.get()599 });600 self.update_local_resolution(module, key, orig_ident_span, |this, resolution| {601 if res == Res::Err602 && let Some(old_decl) = resolution.best_decl()603 && old_decl.res() != Res::Err604 {605 // Do not override real declarations with `Res::Err`s from error recovery.606 // FIXME: this special case shouldn't be necessary, but removing it triggers an ICE607 // due to some other issues (#157406, tests/ui/imports/dummy-import-ice.rs).608 return Ok(());609 }610 if decl.is_glob_import() {611 resolution.glob_decl = Some(match resolution.glob_decl {612 Some(old_decl) => this.select_glob_decl(old_decl, decl),613 None => decl,614 });615 } else {616 resolution.non_glob_decl = Some(match resolution.non_glob_decl {617 Some(old_decl) => return Err(old_decl),618 None => decl,619 })620 }621622 Ok(())623 })624 }625626 // Use `f` to mutate the resolution of the name in the module.627 // If the resolution becomes a success, define it in the module's glob importers.628 fn update_local_resolution<T, F>(629 &mut self,630 module: LocalModule<'ra>,631 key: BindingKey,632 orig_ident_span: Span,633 f: F,634 ) -> T635 where636 F: FnOnce(&Resolver<'ra, 'tcx>, &mut NameResolution<'ra>) -> T,637 {638 // Ensure that `resolution` isn't borrowed when defining in the module's glob importers,639 // during which the resolution might end up getting re-defined via a glob cycle.640 let (binding, t) = {641 let resolution = &mut *self642 .resolution_or_default(module.to_module(), key, orig_ident_span)643 .borrow_mut(self);644 let old_decl = resolution.determined_decl();645 let old_vis = old_decl.map(|d| d.vis());646647 let t = f(self, resolution);648649 if let Some(binding) = resolution.determined_decl()650 && (old_decl != Some(binding) || old_vis != Some(binding.vis()))651 {652 (binding, t)653 } else {654 return t;655 }656 };657658 let Ok(glob_importers) = module.glob_importers.try_borrow_mut(self) else {659 return t;660 };661662 // Define or update `binding` in `module`s glob importers.663 for import in glob_importers.iter() {664 let mut ident = key.ident;665 let scope = match ident666 .ctxt667 .update_unchecked(|ctxt| ctxt.reverse_glob_adjust(module.expansion, import.span))668 {669 Some(Some(def)) => self.expn_def_scope(def),670 Some(None) => import.parent_scope.module,671 None => continue,672 };673 if self.is_accessible_from(binding.vis(), scope) {674 let import_decl = self.new_import_decl(binding, *import);675 self.try_plant_decl_into_local_module(ident, orig_ident_span, key.ns, import_decl)676 .expect("planting a glob cannot fail");677 }678 }679680 t681 }682683 // Define a dummy resolution containing a `Res::Err` as a placeholder for a failed684 // or indeterminate resolution, also mark such failed imports as used to avoid duplicate diagnostics.685 fn import_dummy_binding(&mut self, import: Import<'ra>, is_indeterminate: bool) {686 if let ImportKind::Single { target, ref decls, .. } = import.kind {687 if !(is_indeterminate || decls.iter().all(|d| d.get().decl().is_none())) {688 return; // Has resolution, do not create the dummy binding689 }690 let dummy_decl = self.dummy_decl;691 let dummy_decl = self.new_import_decl(dummy_decl, import);692 self.per_ns(|this, ns| {693 let ident = IdentKey::new(target);694 // This can fail, dummies are inserted only in non-occupied slots.695 let _ = this.try_plant_decl_into_local_module(ident, target.span, ns, dummy_decl);696 // Don't remove underscores from `single_imports`, they were never added.697 if target.name != kw::Underscore {698 let key = BindingKey::new(ident, ns);699 this.update_local_resolution(700 import.parent_scope.module.expect_local(),701 key,702 target.span,703 |_, resolution| {704 resolution.single_imports.swap_remove(&import);705 },706 )707 }708 });709 self.record_use(target, dummy_decl, Used::Other);710 } else if import.imported_module.get().is_none() {711 self.import_use_map.insert(import, Used::Other);712 if let Some(id) = import.id() {713 self.used_imports.insert(id);714 }715 }716 }717718 // Import resolution719 //720 // This is a batched fixed-point algorithm. Each import is resolved in721 // isolation, with any resolutions collected for later.722 // After a full pass over the current set of `indeterminate_imports`,723 // the collected resolutions are committed together. The process724 // repeats until either no imports remain or no further progress can725 // be made.726727 /// Resolves all imports for the crate. This method performs the fixed-728 /// point iteration.729 pub(crate) fn resolve_imports(&mut self) {730 let mut prev_indeterminate_count = usize::MAX;731 let mut indeterminate_count = self.indeterminate_imports.len() * 3;732 while indeterminate_count < prev_indeterminate_count {733 prev_indeterminate_count = indeterminate_count;734 indeterminate_count = 0;735 let mut resolutions = Vec::new();736 self.assert_speculative = true;737 for import in mem::take(&mut self.indeterminate_imports) {738 let (resolution, import_indeterminate_count) = self.cm().resolve_import(import);739 indeterminate_count += import_indeterminate_count;740 match import_indeterminate_count {741 0 => self.determined_imports.push(import),742 _ => self.indeterminate_imports.push(import),743 }744 if let Some(resolution) = resolution {745 resolutions.push((import, resolution));746 }747 }748 self.assert_speculative = false;749 self.write_import_resolutions(resolutions);750 }751 }752753 fn write_import_resolutions(754 &mut self,755 import_resolutions: Vec<(Import<'ra>, ImportResolution<'ra>)>,756 ) {757 for (import, resolution) in &import_resolutions {758 let ImportResolution { imported_module, .. } = resolution;759 import.imported_module.set(Some(*imported_module), self);760761 if import.is_glob()762 && let ModuleOrUniformRoot::Module(module) = imported_module763 && import.parent_scope.module != *module764 && module.is_local()765 {766 module.glob_importers.borrow_mut(self).push(*import);767 }768 }769770 for (import, resolution) in import_resolutions {771 let ImportResolution { imported_module, kind: resolution_kind } = resolution;772773 match (&import.kind, resolution_kind) {774 (775 ImportKind::Single { target, decls, .. },776 ImportResolutionKind::Single(import_decls),777 ) => {778 self.per_ns(|this, ns| {779 match import_decls[ns] {780 PendingDecl::Ready(Some(import_decl)) => {781 if import_decl.is_assoc_item()782 && !this.tcx.features().import_trait_associated_functions()783 {784 feature_err(785 this.tcx.sess,786 sym::import_trait_associated_functions,787 import.span,788 "`use` associated items of traits is unstable",789 )790 .emit();791 }792 this.plant_decl_into_local_module(793 IdentKey::new(*target),794 target.span,795 ns,796 import_decl,797 );798 decls[ns].set(PendingDecl::Ready(Some(import_decl)), this);799 }800 PendingDecl::Ready(None) => {801 // Don't remove underscores from `single_imports`, they were never added.802 if target.name != kw::Underscore {803 let key = BindingKey::new(IdentKey::new(*target), ns);804 this.update_local_resolution(805 import.parent_scope.module.expect_local(),806 key,807 target.span,808 |_, resolution| {809 resolution.single_imports.swap_remove(&import);810 },811 );812 }813 decls[ns].set(PendingDecl::Ready(None), this);814 }815 PendingDecl::Pending => {}816 }817 });818 }819 (ImportKind::Glob { id, .. }, ImportResolutionKind::Glob(imported_decls)) => {820 let ModuleOrUniformRoot::Module(module) = imported_module else {821 self.dcx().emit_err(CannotGlobImportAllCrates { span: import.span });822 continue;823 };824825 if module.is_trait() && !self.tcx.features().import_trait_associated_functions()826 {827 feature_err(828 self.tcx.sess,829 sym::import_trait_associated_functions,830 import.span,831 "`use` associated items of traits is unstable",832 )833 .emit();834 }835836 for (binding, key, orig_ident_span) in imported_decls {837 let import_decl = self.new_import_decl(binding, import);838 let _ = self839 .try_plant_decl_into_local_module(840 key.ident,841 orig_ident_span,842 key.ns,843 import_decl,844 )845 .expect("planting a glob cannot fail");846 }847848 self.record_partial_res(*id, PartialRes::new(module.res().unwrap()));849 }850851 // Something weird happened, which shouldn't have happened.852 _ => unreachable!("mismatched import and resolution kind"),853 }854 }855 }856857 pub(crate) fn finalize_imports(&mut self) {858 let mut module_children = Default::default();859 let mut ambig_module_children = Default::default();860 for module in &self.local_modules {861 self.finalize_resolutions_in(*module, &mut module_children, &mut ambig_module_children);862 }863 self.module_children = module_children;864 self.ambig_module_children = ambig_module_children;865866 let mut seen_spans = FxHashSet::default();867 let mut errors = vec![];868 let mut prev_root_id: NodeId = NodeId::ZERO;869 let determined_imports = mem::take(&mut self.determined_imports);870 let indeterminate_imports = mem::take(&mut self.indeterminate_imports);871872 let mut glob_error = false;873 for (is_indeterminate, import) in determined_imports874 .iter()875 .map(|i| (false, i))876 .chain(indeterminate_imports.iter().map(|i| (true, i)))877 {878 let unresolved_import_error = self.finalize_import(*import);879 // If this import is unresolved then create a dummy import880 // resolution for it so that later resolve stages won't complain.881 self.import_dummy_binding(*import, is_indeterminate);882883 let Some(err) = unresolved_import_error else { continue };884885 glob_error |= import.is_glob();886887 if let ImportKind::Single { source, ref decls, .. } = import.kind888 && source.name == kw::SelfLower889 // Silence `unresolved import` error if E0429 is already emitted890 && let PendingDecl::Ready(None) = decls.value_ns.get()891 {892 continue;893 }894895 if prev_root_id != NodeId::ZERO && prev_root_id != import.root_id && !errors.is_empty()896 {897 // In the case of a new import line, throw a diagnostic message898 // for the previous line.899 self.throw_unresolved_import_error(errors, glob_error);900 errors = vec![];901 }902 if seen_spans.insert(err.span) {903 errors.push((*import, err));904 prev_root_id = import.root_id;905 }906 }907908 if self.cstore().had_extern_crate_load_failure() {909 self.tcx.sess.dcx().abort_if_errors();910 }911912 if !errors.is_empty() {913 self.throw_unresolved_import_error(errors, glob_error);914 return;915 }916917 for import in &indeterminate_imports {918 let path = import_path_to_string(919 &import.module_path.iter().map(|seg| seg.ident).collect::<Vec<_>>(),920 &import.kind,921 import.span,922 );923 // FIXME: there should be a better way of doing this than924 // formatting this as a string then checking for `::`925 if path.contains("::") {926 let err = UnresolvedImportError {927 span: import.span,928 label: None,929 note: None,930 suggestion: None,931 candidates: None,932 segment: None,933 module: None,934 on_unknown_attr: import.on_unknown_attr.clone(),935 };936 errors.push((*import, err))937 }938 }939940 if !errors.is_empty() {941 self.throw_unresolved_import_error(errors, glob_error);942 }943 }944945 pub(crate) fn lint_reexports(&mut self, exported_ambiguities: FxHashSet<Decl<'ra>>) {946 for module in &self.local_modules {947 for (key, resolution) in self.resolutions(module.to_module()).borrow().iter() {948 let resolution = resolution.borrow();949 let Some(binding) = resolution.best_decl() else { continue };950951 // Report "cannot reexport" errors for exotic cases involving macros 2.0952 // privacy bending or invariant-breaking code under deprecation lints.953 for decl in [resolution.non_glob_decl, resolution.glob_decl] {954 if let Some(decl) = decl955 && let DeclKind::Import { source_decl, import } = decl.kind956 // FIXME: Do not check visibility-ambiguous imports for now. To check them957 // properly we need to preserve all imports in ambiguous glob sets and958 // check them all individually.959 && decl.ambiguity_vis_max.get().is_none()960 {961 // The source entity is too private to be reexported962 // with the given import declaration's visibility.963 let ord = source_decl.vis().partial_cmp(decl.vis(), self.tcx);964 if matches!(ord, None | Some(Ordering::Less)) {965 let ident = match import.kind {966 ImportKind::Single { source, .. } => source,967 _ => key.ident.orig(resolution.orig_ident_span),968 };969 if let Some(lint) =970 self.report_cannot_reexport(import, source_decl, ident, key.ns)971 {972 self.lint_buffer.add_early_lint(lint);973 }974 }975 }976 }977978 if let DeclKind::Import { import, .. } = binding.kind979 && let Some((amb_binding, _)) = binding.ambiguity.get()980 && binding.res() != Res::Err981 && exported_ambiguities.contains(&binding)982 {983 self.lint_buffer.buffer_lint(984 AMBIGUOUS_GLOB_REEXPORTS,985 import.root_id,986 import.root_span,987 diagnostics::AmbiguousGlobReexports {988 name: key.ident.name.to_string(),989 namespace: key.ns.descr().to_string(),990 first_reexport: import.root_span,991 duplicate_reexport: amb_binding.span,992 },993 );994 }995996 if let Some(glob_decl) = resolution.glob_decl997 && resolution.non_glob_decl.is_some()998 {999 if binding.res() != Res::Err1000 && glob_decl.res() != Res::Err1001 && let DeclKind::Import { import: glob_import, .. } = glob_decl.kind1002 && let Some(glob_import_def_id) = glob_import.def_id()1003 && self.effective_visibilities.is_exported(glob_import_def_id)1004 && glob_decl.vis().is_public()1005 && !binding.vis().is_public()1006 {1007 let binding_id = match binding.kind {1008 DeclKind::Def(res) => {1009 Some(self.def_id_to_node_id(res.def_id().expect_local()))1010 }1011 DeclKind::Import { import, .. } => import.id(),1012 };1013 if let Some(binding_id) = binding_id {1014 self.lint_buffer.buffer_lint(1015 HIDDEN_GLOB_REEXPORTS,1016 binding_id,1017 binding.span,1018 diagnostics::HiddenGlobReexports {1019 name: key.ident.name.to_string(),1020 namespace: key.ns.descr().to_owned(),1021 glob_reexport: glob_decl.span,1022 private_item: binding.span,1023 },1024 );1025 }1026 }1027 }10281029 if let DeclKind::Import { import, .. } = binding.kind1030 && let Some(binding_id) = import.id()1031 && let import_def_id = import.def_id().unwrap()1032 && self.effective_visibilities.is_exported(import_def_id)1033 && let Res::Def(reexported_kind, reexported_def_id) = binding.res()1034 && !matches!(reexported_kind, DefKind::Ctor(..))1035 && !reexported_def_id.is_local()1036 && self.tcx.is_private_dep(reexported_def_id.krate)1037 {1038 self.lint_buffer.buffer_lint(1039 EXPORTED_PRIVATE_DEPENDENCIES,1040 binding_id,1041 binding.span,1042 crate::diagnostics::ReexportPrivateDependency {1043 name: key.ident.name,1044 kind: binding.res().descr(),1045 krate: self.tcx.crate_name(reexported_def_id.krate),1046 },1047 );1048 }1049 }1050 }1051 }10521053 /// Attempts to resolve the given import, returning:1054 /// - `0` means its resolution is determined.1055 /// - Other values mean that indeterminate exists under certain namespaces.1056 ///1057 /// Meanwhile, if resolution is successful, its result is returned.1058 fn resolve_import<'r>(1059 mut self: CmResolver<'r, 'ra, 'tcx>,1060 import: Import<'ra>,1061 ) -> (Option<ImportResolution<'ra>>, usize) {1062 debug!(1063 "(resolving import for module) resolving import `{}::{}` in `{}`",1064 Segment::names_to_string(&import.module_path),1065 import_kind_to_string(&import.kind),1066 module_to_string(import.parent_scope.module).unwrap_or_else(|| "???".to_string()),1067 );1068 let module = if let Some(module) = import.imported_module.get() {1069 module1070 } else {1071 let path_res = self.reborrow().maybe_resolve_path(1072 &import.module_path,1073 None,1074 &import.parent_scope,1075 Some(import),1076 );10771078 match path_res {1079 PathResult::Module(module) => module,1080 PathResult::Indeterminate => return (None, 3),1081 PathResult::NonModule(..) | PathResult::Failed { .. } => return (None, 0),1082 }1083 };10841085 let (source, bindings) = match import.kind {1086 ImportKind::Single { source, ref decls, .. } => (source, decls),1087 ImportKind::Glob { .. } => {1088 let import_resolution = ImportResolution {1089 imported_module: module,1090 kind: self.resolve_glob_import(import, module),1091 };1092 return (Some(import_resolution), 0);1093 }1094 _ => unreachable!(),1095 };10961097 let mut import_decls = PerNS::default();1098 let mut indeterminate_count = 0;1099 self.per_ns_cm(|mut this, ns| {1100 if bindings[ns].get() != PendingDecl::Pending {1101 return;1102 };1103 let binding_result = this.reborrow().maybe_resolve_ident_in_module(1104 module,1105 source,1106 ns,1107 &import.parent_scope,1108 Some(import),1109 );1110 let pending_decl = match binding_result {1111 Ok(binding) => {1112 // We need the `target`, `source` can be extracted.1113 let import_decl = this.new_import_decl(binding, import);1114 PendingDecl::Ready(Some(import_decl))1115 }1116 Err(Determinacy::Determined) => PendingDecl::Ready(None),1117 Err(Determinacy::Undetermined) => {1118 indeterminate_count += 1;1119 PendingDecl::Pending1120 }1121 };1122 import_decls[ns] = pending_decl;1123 });1124 let import_resolution = ImportResolution {1125 imported_module: module,1126 kind: ImportResolutionKind::Single(import_decls),1127 };11281129 (Some(import_resolution), indeterminate_count)1130 }11311132 /// Performs final import resolution, consistency checks and error reporting.1133 ///1134 /// Optionally returns an unresolved import error. This error is buffered and used to1135 /// consolidate multiple unresolved import errors into a single diagnostic.1136 fn finalize_import(&mut self, import: Import<'ra>) -> Option<UnresolvedImportError> {1137 let ignore_decl = match &import.kind {1138 ImportKind::Single { decls, .. } => decls[TypeNS].get().decl(),1139 _ => None,1140 };1141 let ambiguity_errors_len = |errors: &Vec<AmbiguityError<'_>>| {1142 errors.iter().filter(|error| error.warning.is_none()).count()1143 };1144 let prev_ambiguity_errors_len = ambiguity_errors_len(&self.ambiguity_errors);1145 let finalize = Finalize::with_root_span(import.root_id, import.span, import.root_span);11461147 // We'll provide more context to the privacy errors later, up to `len`.1148 let privacy_errors_len = self.privacy_errors.len();11491150 let path_res = self.cm().resolve_path(1151 &import.module_path,1152 None,1153 &import.parent_scope,1154 Some(finalize),1155 ignore_decl,1156 Some(import),1157 );11581159 let no_ambiguity =1160 ambiguity_errors_len(&self.ambiguity_errors) == prev_ambiguity_errors_len;11611162 let module = match path_res {1163 PathResult::Module(module) => {1164 // Consistency checks, analogous to `finalize_macro_resolutions`.1165 if let Some(initial_module) = import.imported_module.get() {1166 if module != initial_module && no_ambiguity && !self.issue_145575_hack_applied {1167 span_bug!(import.span, "inconsistent resolution for an import");1168 }1169 } else if self.privacy_errors.is_empty() {1170 self.dcx()1171 .create_err(CannotDetermineImportResolution { span: import.span })1172 .emit();1173 }11741175 module1176 }1177 PathResult::Failed {1178 is_error_from_last_segment: false,1179 span,1180 segment,1181 label,1182 suggestion,1183 module,1184 error_implied_by_parse_error: _,1185 message,1186 note: _,1187 } => {1188 if no_ambiguity {1189 if !self.issue_145575_hack_applied {1190 assert!(import.imported_module.get().is_none());1191 }1192 self.report_error(1193 span,1194 ResolutionError::FailedToResolve {1195 segment: segment.name,1196 label,1197 suggestion,1198 module,1199 message,1200 },1201 );1202 }1203 return None;1204 }1205 PathResult::Failed {1206 is_error_from_last_segment: true,1207 span,1208 label,1209 suggestion,1210 module,1211 segment,1212 note,1213 ..1214 } => {1215 if no_ambiguity {1216 if !self.issue_145575_hack_applied {1217 assert!(import.imported_module.get().is_none());1218 }1219 let module = if let Some(ModuleOrUniformRoot::Module(m)) = module {1220 m.opt_def_id()1221 } else {1222 None1223 };1224 let err = match self1225 .make_path_suggestion(import.module_path.clone(), &import.parent_scope)1226 {1227 Some((suggestion, note)) => UnresolvedImportError {1228 span,1229 label: None,1230 note,1231 suggestion: Some((1232 vec![(span, Segment::names_to_string(&suggestion))],1233 String::from("a similar path exists"),1234 Applicability::MaybeIncorrect,1235 )),1236 candidates: None,1237 segment: Some(segment),1238 module,1239 on_unknown_attr: import.on_unknown_attr.clone(),1240 },1241 None => UnresolvedImportError {1242 span,1243 label: Some(label),1244 note,1245 suggestion,1246 candidates: None,1247 segment: Some(segment),1248 module,1249 on_unknown_attr: import.on_unknown_attr.clone(),1250 },1251 };1252 return Some(err);1253 }1254 return None;1255 }1256 PathResult::NonModule(partial_res) => {1257 if no_ambiguity && partial_res.full_res() != Some(Res::Err) {1258 // Check if there are no ambiguities and the result is not dummy.1259 assert!(import.imported_module.get().is_none());1260 }1261 // The error was already reported earlier.1262 return None;1263 }1264 PathResult::Indeterminate => unreachable!(),1265 };12661267 let (ident, target, bindings, import_id) = match import.kind {1268 ImportKind::Single { source, target, ref decls, id, .. } => (source, target, decls, id),1269 ImportKind::Glob { ref max_vis, id, def_id } => {1270 if import.module_path.len() <= 1 {1271 // HACK(eddyb) `lint_if_path_starts_with_module` needs at least1272 // 2 segments, so the `resolve_path` above won't trigger it.1273 let mut full_path = import.module_path.clone();1274 full_path.push(Segment::from_ident(Ident::dummy()));1275 self.lint_if_path_starts_with_module(finalize, &full_path, None);1276 }12771278 if let ModuleOrUniformRoot::Module(module) = module1279 && module == import.parent_scope.module1280 {1281 // Importing a module into itself is not allowed.1282 return Some(UnresolvedImportError {1283 span: import.span,1284 label: Some(String::from("cannot glob-import a module into itself")),1285 note: None,1286 suggestion: None,1287 candidates: None,1288 segment: None,1289 module: None,1290 on_unknown_attr: None,1291 });1292 }1293 if let Some(max_vis) = max_vis.get()1294 && import.vis.greater_than(max_vis, self.tcx)1295 {1296 self.lint_buffer.buffer_lint(1297 UNUSED_IMPORTS,1298 id,1299 import.span,1300 crate::diagnostics::RedundantImportVisibility {1301 span: import.span,1302 help: (),1303 max_vis: max_vis.to_string(def_id, self.tcx),1304 import_vis: import.vis.to_string(def_id, self.tcx),1305 },1306 );1307 }1308 return None;1309 }1310 _ => unreachable!(),1311 };13121313 if self.privacy_errors.len() != privacy_errors_len {1314 // Get the Res for the last element, so that we can point to alternative ways of1315 // importing it if available.1316 let mut path = import.module_path.clone();1317 path.push(Segment::from_ident(ident));1318 if let PathResult::Module(ModuleOrUniformRoot::Module(module)) = self.cm().resolve_path(1319 &path,1320 None,1321 &import.parent_scope,1322 Some(finalize),1323 ignore_decl,1324 None,1325 ) {1326 let res = module.res().map(|r| (r, ident));1327 for error in &mut self.privacy_errors[privacy_errors_len..] {1328 error.outermost_res = res;1329 }1330 } else {1331 // The final item is not a module (e.g., a struct, function, or macro).1332 // Resolve it directly in the parent module to get its Res, so1333 // `report_privacy_error()` can search for public re-export paths.1334 for ns in [TypeNS, ValueNS, MacroNS] {1335 if let Ok(binding) = self.cm().resolve_ident_in_module(1336 module,1337 ident,1338 ns,1339 &import.parent_scope,1340 None,1341 ignore_decl,1342 None,1343 ) {1344 let res = binding.res();1345 for error in &mut self.privacy_errors[privacy_errors_len..] {1346 error.outermost_res = Some((res, ident));1347 }1348 break;1349 }1350 }1351 }1352 }13531354 let mut all_ns_err = true;1355 self.per_ns(|this, ns| {1356 let binding = this.cm().resolve_ident_in_module(1357 module,1358 ident,1359 ns,1360 &import.parent_scope,1361 Some(Finalize {1362 report_private: false,1363 import: Some(import.summary()),1364 ..finalize1365 }),1366 bindings[ns].get().decl(),1367 Some(import),1368 );13691370 match binding {1371 Ok(binding) => {1372 // Consistency checks, analogous to `finalize_macro_resolutions`.1373 let initial_res = bindings[ns].get().decl().map(|binding| {1374 let initial_binding = binding.import_source();1375 all_ns_err = false;1376 if target.name == kw::Underscore1377 && initial_binding.is_extern_crate()1378 && !initial_binding.is_import()1379 {1380 let used = if import.module_path.is_empty() {1381 Used::Scope1382 } else {1383 Used::Other1384 };1385 this.record_use(ident, binding, used);1386 }1387 initial_binding.res()1388 });1389 let res = binding.res();1390 let has_ambiguity_error =1391 this.ambiguity_errors.iter().any(|error| error.warning.is_none());1392 if res == Res::Err || has_ambiguity_error {1393 this.dcx()1394 .span_delayed_bug(import.span, "some error happened for an import");1395 return;1396 }1397 if let Some(initial_res) = initial_res {1398 if res != initial_res && !this.issue_145575_hack_applied {1399 span_bug!(import.span, "inconsistent resolution for an import");1400 }1401 } else if this.privacy_errors.is_empty() {1402 this.dcx()1403 .create_err(CannotDetermineImportResolution { span: import.span })1404 .emit();1405 }1406 }1407 Err(..) => {1408 // FIXME: This assert may fire if public glob is later shadowed by a private1409 // single import (see test `issue-55884-2.rs`). In theory single imports should1410 // always block globs, even if they are not yet resolved, so that this kind of1411 // self-inconsistent resolution never happens.1412 // Re-enable the assert when the issue is fixed.1413 // assert!(result[ns].get().is_err());1414 }1415 }1416 });14171418 if all_ns_err {1419 let mut all_ns_failed = true;1420 self.per_ns(|this, ns| {1421 let binding = this.cm().resolve_ident_in_module(1422 module,1423 ident,1424 ns,1425 &import.parent_scope,1426 Some(finalize),1427 None,1428 None,1429 );1430 if binding.is_ok() {1431 all_ns_failed = false;1432 }1433 });14341435 return if all_ns_failed {1436 let names = match module {1437 ModuleOrUniformRoot::Module(module) => {1438 self.resolutions(module)1439 .borrow()1440 .iter()1441 .filter_map(|(BindingKey { ident: i, .. }, resolution)| {1442 if i.name == ident.name {1443 return None;1444 } // Never suggest the same name1445 if i.name == kw::Underscore {1446 return None;1447 } // `use _` is never valid14481449 let resolution = resolution.borrow();1450 if let Some(name_binding) = resolution.best_decl() {1451 match name_binding.kind {1452 DeclKind::Import { source_decl, .. } => {1453 match source_decl.kind {1454 // Never suggest names that previously could not1455 // be resolved.1456 DeclKind::Def(Res::Err) => None,1457 _ => Some(i.name),1458 }1459 }1460 _ => Some(i.name),1461 }1462 } else if resolution.single_imports.is_empty() {1463 None1464 } else {1465 Some(i.name)1466 }1467 })1468 .collect()1469 }1470 _ => Vec::new(),1471 };14721473 let lev_suggestion =1474 find_best_match_for_name(&names, ident.name, None).map(|suggestion| {1475 (1476 vec![(ident.span, suggestion.to_string())],1477 String::from("a similar name exists in the module"),1478 Applicability::MaybeIncorrect,1479 )1480 });14811482 let (suggestion, note) =1483 match self.check_for_module_export_macro(import, module, ident) {1484 Some((suggestion, note)) => (suggestion.or(lev_suggestion), note),1485 _ => (lev_suggestion, None),1486 };14871488 // If importing of trait asscoiated items is enabled, an also find an1489 // `Enum`, then note that inherent associated items cannot be imported.1490 let note = if self.tcx.features().import_trait_associated_functions()1491 && let PathResult::Module(ModuleOrUniformRoot::Module(m)) = path_res1492 && let Some(Res::Def(DefKind::Enum, _)) = m.res()1493 {1494 note.or(Some(1495 "cannot import inherent associated items, only trait associated items"1496 .to_string(),1497 ))1498 } else {1499 note1500 };15011502 let label = match module {1503 ModuleOrUniformRoot::Module(module) => {1504 let module_str = module_to_string(module);1505 if let Some(module_str) = module_str {1506 format!("no `{ident}` in `{module_str}`")1507 } else {1508 format!("no `{ident}` in the root")1509 }1510 }1511 _ => {1512 if !ident.is_path_segment_keyword() {1513 format!("no external crate `{ident}`")1514 } else {1515 // HACK(eddyb) this shows up for `self` & `super`, which1516 // should work instead - for now keep the same error message.1517 format!("no `{ident}` in the root")1518 }1519 }1520 };15211522 let parent_suggestion =1523 self.lookup_import_candidates(ident, TypeNS, &import.parent_scope, |_| true);15241525 Some(UnresolvedImportError {1526 span: import.span,1527 label: Some(label),1528 note,1529 suggestion,1530 candidates: if !parent_suggestion.is_empty() {1531 Some(parent_suggestion)1532 } else {1533 None1534 },1535 module: import.imported_module.get().and_then(|module| {1536 if let ModuleOrUniformRoot::Module(m) = module {1537 m.opt_def_id()1538 } else {1539 None1540 }1541 }),1542 segment: Some(ident),1543 on_unknown_attr: import.on_unknown_attr.clone(),1544 })1545 } else {1546 // `resolve_ident_in_module` reported a privacy error.1547 None1548 };1549 }15501551 let mut reexport_error = None;1552 let mut any_successful_reexport = false;1553 self.per_ns(|this, ns| {1554 let Some(binding) = bindings[ns].get().decl() else {1555 return;1556 };15571558 if import.vis.greater_than(binding.vis(), this.tcx) {1559 // In isolation, a declaration like this is not an error, but if *all* 1-31560 // declarations introduced by the import are more private than the import item's1561 // nominal visibility, then it's an error.1562 reexport_error = Some((ns, binding.import_source()));1563 } else {1564 any_successful_reexport = true;1565 }1566 });15671568 if !any_successful_reexport {1569 let (ns, binding) = reexport_error.unwrap();1570 if let Some(lint) = self.report_cannot_reexport(import, binding, ident, ns) {1571 self.lint_buffer.add_early_lint(lint);1572 }1573 }15741575 if import.module_path.len() <= 1 {1576 // HACK(eddyb) `lint_if_path_starts_with_module` needs at least1577 // 2 segments, so the `resolve_path` above won't trigger it.1578 let mut full_path = import.module_path.clone();1579 full_path.push(Segment::from_ident(ident));1580 self.per_ns(|this, ns| {1581 if let Some(binding) = bindings[ns].get().decl().map(|b| b.import_source()) {1582 this.lint_if_path_starts_with_module(finalize, &full_path, Some(binding));1583 }1584 });1585 }15861587 // Record what this import resolves to for later uses in documentation,1588 // this may resolve to either a value or a type, but for documentation1589 // purposes it's good enough to just favor one over the other.1590 self.per_ns(|this, ns| {1591 if let Some(binding) = bindings[ns].get().decl().map(|b| b.import_source()) {1592 this.owners.get_mut(&import_id).unwrap().import_res[ns] = Some(binding.res());1593 }1594 });15951596 debug!("(resolving single import) successfully resolved import");1597 None1598 }15991600 fn report_cannot_reexport(1601 &self,1602 import: Import<'ra>,1603 decl: Decl<'ra>,1604 ident: Ident,1605 ns: Namespace,1606 ) -> Option<BufferedEarlyLint> {1607 let crate_private_reexport = match decl.vis() {1608 Visibility::Restricted(def_id) if def_id.is_top_level_module() => true,1609 _ => false,1610 };16111612 if let Some(extern_crate_id) = pub_use_of_private_extern_crate_hack(import.summary(), decl)1613 {1614 let ImportKind::Single { id, .. } = import.kind else { unreachable!() };1615 let sugg = self.tcx.source_span(extern_crate_id).shrink_to_lo();1616 let diagnostic = crate::diagnostics::PrivateExternCrateReexport { ident, sugg };1617 return Some(BufferedEarlyLint {1618 lint_id: LintId::of(PUB_USE_OF_PRIVATE_EXTERN_CRATE),1619 node_id: id,1620 span: Some(import.span.into()),1621 diagnostic: diagnostic.into(),1622 });1623 } else if ns == TypeNS {1624 let err = if crate_private_reexport {1625 self.dcx().create_err(CannotBeReexportedCratePublicNS { span: import.span, ident })1626 } else {1627 self.dcx().create_err(CannotBeReexportedPrivateNS { span: import.span, ident })1628 };1629 err.emit();1630 } else {1631 let mut err = if crate_private_reexport {1632 self.dcx().create_err(CannotBeReexportedCratePublic { span: import.span, ident })1633 } else {1634 self.dcx().create_err(CannotBeReexportedPrivate { span: import.span, ident })1635 };16361637 match decl.kind {1638 // exclude decl_macro1639 DeclKind::Def(Res::Def(DefKind::Macro(_), def_id))1640 if let SyntaxExtensionKind::MacroRules(mr) =1641 &self.get_macro_by_def_id(def_id).kind1642 && mr.is_macro_rules() =>1643 {1644 err.subdiagnostic(ConsiderAddingMacroExport { span: decl.span });1645 err.subdiagnostic(ConsiderMarkingAsPubCrate { vis_span: import.vis_span });1646 }1647 _ => {1648 err.subdiagnostic(ConsiderMarkingAsPub { span: import.span, ident });1649 }1650 }1651 err.emit();1652 }16531654 None1655 }16561657 pub(crate) fn check_for_redundant_imports(&mut self, import: Import<'ra>) -> bool {1658 // This function is only called for single imports.1659 let ImportKind::Single { source, target, ref decls, id, def_id, .. } = import.kind else {1660 unreachable!()1661 };16621663 // Skip if the import is of the form `use source as target` and source != target.1664 if source != target {1665 return false;1666 }16671668 // Skip if the import was produced by a macro.1669 if import.parent_scope.expansion != LocalExpnId::ROOT {1670 return false;1671 }16721673 // Skip if we are inside a named module (in contrast to an anonymous1674 // module defined by a block).1675 // Skip if the import is public or was used through non scope-based resolution,1676 // e.g. through a module-relative path.1677 if self.import_use_map.get(&import) == Some(&Used::Other)1678 || self.effective_visibilities.is_exported(def_id)1679 {1680 return false;1681 }16821683 let mut is_redundant = true;1684 let mut redundant_span = PerNS { value_ns: None, type_ns: None, macro_ns: None };1685 self.per_ns(|this, ns| {1686 let binding = decls[ns].get().decl().map(|b| b.import_source());1687 if is_redundant && let Some(binding) = binding {1688 if binding.res() == Res::Err {1689 return;1690 }16911692 match this.cm().resolve_ident_in_scope_set(1693 target,1694 ScopeSet::All(ns),1695 &import.parent_scope,1696 None,1697 decls[ns].get().decl(),1698 None,1699 ) {1700 Ok(other_binding) => {1701 is_redundant = binding.res() == other_binding.res()1702 && !other_binding.is_ambiguity_recursive();1703 if is_redundant {1704 redundant_span[ns] =1705 Some((other_binding.span, other_binding.is_import()));1706 }1707 }1708 Err(_) => is_redundant = false,1709 }1710 }1711 });17121713 if is_redundant && !redundant_span.is_empty() {1714 let mut redundant_spans: Vec<_> = redundant_span.present_items().collect();1715 redundant_spans.sort();1716 redundant_spans.dedup();1717 self.lint_buffer.dyn_buffer_lint(1718 REDUNDANT_IMPORTS,1719 id,1720 import.span,1721 move |dcx, level| {1722 let ident = source;1723 let subs = redundant_spans1724 .into_iter()1725 .map(|(span, is_imported)| match (span.is_dummy(), is_imported) {1726 (false, true) => {1727 diagnostics::RedundantImportSub::ImportedHere { span, ident }1728 }1729 (false, false) => {1730 diagnostics::RedundantImportSub::DefinedHere { span, ident }1731 }1732 (true, true) => {1733 diagnostics::RedundantImportSub::ImportedPrelude { span, ident }1734 }1735 (true, false) => {1736 diagnostics::RedundantImportSub::DefinedPrelude { span, ident }1737 }1738 })1739 .collect();1740 diagnostics::RedundantImport { subs, ident }.into_diag(dcx, level)1741 },1742 );1743 return true;1744 }17451746 false1747 }17481749 fn resolve_glob_import(1750 &self,1751 import: Import<'ra>,1752 imported_module: ModuleOrUniformRoot<'ra>,1753 ) -> ImportResolutionKind<'ra> {1754 let import_bindings = match imported_module {1755 ModuleOrUniformRoot::Module(module) if module != import.parent_scope.module => self1756 .resolutions(module)1757 .borrow()1758 .iter()1759 .filter_map(|(key, resolution)| {1760 let res = resolution.borrow();1761 let decl = res.determined_decl()?;1762 let mut key = *key;1763 let scope = match key.ident.ctxt.update_unchecked(|ctxt| {1764 ctxt.reverse_glob_adjust(module.expansion, import.span)1765 }) {1766 Some(Some(def)) => self.expn_def_scope(def),1767 Some(None) => import.parent_scope.module,1768 None => return None,1769 };1770 self.is_accessible_from(decl.vis(), scope).then_some((1771 decl,1772 key,1773 res.orig_ident_span,1774 ))1775 })1776 .collect::<Vec<_>>(),17771778 // Errors are reported in `write_imports_resolutions`1779 _ => vec![],1780 };17811782 ImportResolutionKind::Glob(import_bindings)1783 }17841785 // Hack for the `rust_embed` regression observed in the crater run of #145108.1786 fn rust_embed_hack(&self, module: LocalModule<'ra>, decl: Decl<'ra>) -> bool {1787 // We are looking for this pattern:1788 // ```rust1789 // #[macro_use]1790 // extern crate rust_embed_impl;1791 // pub use rust_embed_impl::*;1792 //1793 // pub use RustEmbed as Embed;1794 // ```1795 if let DeclKind::Import { source_decl, import } = decl.kind1796 // Check that `decl` is the re-export: "pub use RustEmbed as Embed;"1797 && let ImportKind::Single { source, .. } = import.kind1798 && source.name == sym::RustEmbed1799 // make sure that the import points to the #[macro_use] import1800 && let DeclKind::Import { import, .. } = source_decl.kind1801 && matches!(import.kind, ImportKind::MacroUse { .. })1802 && self.macro_use_prelude.contains_key(&source.name) // and that the name actually exists in the macro_use_prelude1803 // Then check that `RustEmbed` exists in the modules Macro namespace.1804 && let Some(y_decl) = self1805 .resolution(module.to_module(), BindingKey::new(IdentKey::new(source), MacroNS))1806 .and_then(|res| res.best_decl())1807 // which comes from "pub use rust_embed_impl::*"1808 && y_decl.is_glob_import()1809 && y_decl.vis().is_public()1810 {1811 return true;1812 }18131814 false1815 }18161817 // Miscellaneous post-processing, including recording re-exports,1818 // reporting conflicts, and reporting unresolved imports.1819 fn finalize_resolutions_in(1820 &self,1821 module: LocalModule<'ra>,1822 module_children: &mut LocalDefIdMap<Vec<ModChild>>,1823 ambig_module_children: &mut LocalDefIdMap<Vec<AmbigModChild>>,1824 ) {1825 // Since import resolution is finished, globs will not define any more names.1826 *module.globs.borrow_mut(self) = Vec::new();18271828 let Some(def_id) = module.opt_def_id() else { return };18291830 let mut children = Vec::new();1831 let mut ambig_children = Vec::new();18321833 module.to_module().for_each_child(self, |this, ident, orig_ident_span, _, decl| {1834 let res = decl.res().expect_non_local();1835 if res != def::Res::Err {1836 let vis = if this.rust_embed_hack(module, decl) {1837 Visibility::Public1838 } else {1839 decl.vis()1840 };1841 let ident = ident.orig(orig_ident_span);1842 let child = |reexport_chain| ModChild { ident, res, vis, reexport_chain };1843 if let Some((ambig_binding1, ambig_binding2)) = decl.descent_to_ambiguity() {1844 let main = child(ambig_binding1.reexport_chain());1845 let second = ModChild {1846 ident,1847 res: ambig_binding2.res().expect_non_local(),1848 vis: ambig_binding2.vis(),1849 reexport_chain: ambig_binding2.reexport_chain(),1850 };1851 ambig_children.push(AmbigModChild { main, second })1852 } else {1853 children.push(child(decl.reexport_chain()));1854 }1855 }1856 });18571858 if !children.is_empty() {1859 module_children.insert(def_id.expect_local(), children);1860 }1861 if !ambig_children.is_empty() {1862 ambig_module_children.insert(def_id.expect_local(), ambig_children);1863 }1864 }1865}18661867pub(crate) fn import_path_to_string(1868 names: &[Ident],1869 import_kind: &ImportKind<'_>,1870 span: Span,1871) -> String {1872 let pos = names.iter().position(|p| span == p.span && p.name != kw::PathRoot);1873 let global = !names.is_empty() && names[0].name == kw::PathRoot;1874 if let Some(pos) = pos {1875 let names = if global { &names[1..pos + 1] } else { &names[..pos + 1] };1876 names_to_string(names.iter().map(|ident| ident.name))1877 } else {1878 let names = if global { &names[1..] } else { names };1879 if names.is_empty() {1880 import_kind_to_string(import_kind)1881 } else {1882 format!(1883 "{}::{}",1884 names_to_string(names.iter().map(|ident| ident.name)),1885 import_kind_to_string(import_kind),1886 )1887 }1888 }1889}18901891fn import_kind_to_string(import_kind: &ImportKind<'_>) -> String {1892 match import_kind {1893 ImportKind::Single { source, .. } => source.to_string(),1894 ImportKind::Glob { .. } => "*".to_string(),1895 ImportKind::ExternCrate { .. } => "<extern crate>".to_string(),1896 ImportKind::MacroUse { .. } => "#[macro_use]".to_string(),1897 ImportKind::MacroExport => "#[macro_export]".to_string(),1898 }1899}
Findings
✓ No findings reported for this file.