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Diffstat (limited to 'compiler/rustc_resolve/src/lib.rs')
| -rw-r--r-- | compiler/rustc_resolve/src/lib.rs | 2175 |
1 files changed, 2175 insertions, 0 deletions
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs new file mode 100644 index 00000000000..90aa7d79bf0 --- /dev/null +++ b/compiler/rustc_resolve/src/lib.rs @@ -0,0 +1,2175 @@ +//! This crate is responsible for the part of name resolution that doesn't require type checker. +//! +//! Module structure of the crate is built here. +//! Paths in macros, imports, expressions, types, patterns are resolved here. +//! Label and lifetime names are resolved here as well. +//! +//! Type-relative name resolution (methods, fields, associated items) happens in `rustc_hir_analysis`. + +#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")] +#![doc(rust_logo)] +#![feature(rustdoc_internals)] +#![feature(assert_matches)] +#![feature(box_patterns)] +#![feature(extract_if)] +#![feature(if_let_guard)] +#![feature(iter_intersperse)] +#![feature(let_chains)] +#![feature(never_type)] +#![feature(rustc_attrs)] +#![recursion_limit = "256"] +#![allow(rustdoc::private_intra_doc_links)] +#![allow(rustc::potential_query_instability)] +#![allow(internal_features)] + +#[macro_use] +extern crate tracing; + +use errors::{ + ParamKindInEnumDiscriminant, ParamKindInNonTrivialAnonConst, ParamKindInTyOfConstParam, +}; +use rustc_arena::{DroplessArena, TypedArena}; +use rustc_ast::expand::StrippedCfgItem; +use rustc_ast::node_id::NodeMap; +use rustc_ast::{self as ast, attr, NodeId, CRATE_NODE_ID}; +use rustc_ast::{AngleBracketedArg, Crate, Expr, ExprKind, GenericArg, GenericArgs, LitKind, Path}; +use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet}; +use rustc_data_structures::intern::Interned; +use rustc_data_structures::steal::Steal; +use rustc_data_structures::sync::{FreezeReadGuard, Lrc}; +use rustc_errors::{Applicability, DiagnosticBuilder}; +use rustc_expand::base::{DeriveResolutions, SyntaxExtension, SyntaxExtensionKind}; +use rustc_feature::BUILTIN_ATTRIBUTES; +use rustc_hir::def::Namespace::{self, *}; +use rustc_hir::def::NonMacroAttrKind; +use rustc_hir::def::{self, CtorOf, DefKind, DocLinkResMap, LifetimeRes, PartialRes, PerNS}; +use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LocalDefIdMap, LocalDefIdSet}; +use rustc_hir::def_id::{CRATE_DEF_ID, LOCAL_CRATE}; +use rustc_hir::{PrimTy, TraitCandidate}; +use rustc_index::IndexVec; +use rustc_metadata::creader::{CStore, CrateLoader}; +use rustc_middle::metadata::ModChild; +use rustc_middle::middle::privacy::EffectiveVisibilities; +use rustc_middle::query::Providers; +use rustc_middle::span_bug; +use rustc_middle::ty::{self, MainDefinition, RegisteredTools, TyCtxt}; +use rustc_middle::ty::{ResolverGlobalCtxt, ResolverOutputs}; +use rustc_query_system::ich::StableHashingContext; +use rustc_session::lint::LintBuffer; +use rustc_span::hygiene::{ExpnId, LocalExpnId, MacroKind, SyntaxContext, Transparency}; +use rustc_span::symbol::{kw, sym, Ident, Symbol}; +use rustc_span::{Span, DUMMY_SP}; + +use smallvec::{smallvec, SmallVec}; +use std::cell::{Cell, RefCell}; +use std::collections::BTreeSet; +use std::fmt; + +use diagnostics::{ImportSuggestion, LabelSuggestion, Suggestion}; +use imports::{Import, ImportData, ImportKind, NameResolution}; +use late::{HasGenericParams, PathSource, PatternSource}; +use macros::{MacroRulesBinding, MacroRulesScope, MacroRulesScopeRef}; + +use crate::effective_visibilities::EffectiveVisibilitiesVisitor; + +type Res = def::Res<NodeId>; + +mod build_reduced_graph; +mod check_unused; +mod def_collector; +mod diagnostics; +mod effective_visibilities; +mod errors; +mod ident; +mod imports; +mod late; +mod macros; +pub mod rustdoc; + +rustc_fluent_macro::fluent_messages! { "../messages.ftl" } + +#[derive(Debug)] +enum Weak { + Yes, + No, +} + +#[derive(Copy, Clone, PartialEq, Debug)] +enum Determinacy { + Determined, + Undetermined, +} + +impl Determinacy { + fn determined(determined: bool) -> Determinacy { + if determined { Determinacy::Determined } else { Determinacy::Undetermined } + } +} + +/// A specific scope in which a name can be looked up. +/// This enum is currently used only for early resolution (imports and macros), +/// but not for late resolution yet. +#[derive(Clone, Copy, Debug)] +enum Scope<'a> { + DeriveHelpers(LocalExpnId), + DeriveHelpersCompat, + MacroRules(MacroRulesScopeRef<'a>), + CrateRoot, + // The node ID is for reporting the `PROC_MACRO_DERIVE_RESOLUTION_FALLBACK` + // lint if it should be reported. + Module(Module<'a>, Option<NodeId>), + MacroUsePrelude, + BuiltinAttrs, + ExternPrelude, + ToolPrelude, + StdLibPrelude, + BuiltinTypes, +} + +/// Names from different contexts may want to visit different subsets of all specific scopes +/// with different restrictions when looking up the resolution. +/// This enum is currently used only for early resolution (imports and macros), +/// but not for late resolution yet. +#[derive(Clone, Copy, Debug)] +enum ScopeSet<'a> { + /// All scopes with the given namespace. + All(Namespace), + /// Crate root, then extern prelude (used for mixed 2015-2018 mode in macros). + AbsolutePath(Namespace), + /// All scopes with macro namespace and the given macro kind restriction. + Macro(MacroKind), + /// All scopes with the given namespace, used for partially performing late resolution. + /// The node id enables lints and is used for reporting them. + Late(Namespace, Module<'a>, Option<NodeId>), +} + +/// Everything you need to know about a name's location to resolve it. +/// Serves as a starting point for the scope visitor. +/// This struct is currently used only for early resolution (imports and macros), +/// but not for late resolution yet. +#[derive(Clone, Copy, Debug)] +struct ParentScope<'a> { + module: Module<'a>, + expansion: LocalExpnId, + macro_rules: MacroRulesScopeRef<'a>, + derives: &'a [ast::Path], +} + +impl<'a> ParentScope<'a> { + /// Creates a parent scope with the passed argument used as the module scope component, + /// and other scope components set to default empty values. + fn module(module: Module<'a>, resolver: &Resolver<'a, '_>) -> ParentScope<'a> { + ParentScope { + module, + expansion: LocalExpnId::ROOT, + macro_rules: resolver.arenas.alloc_macro_rules_scope(MacroRulesScope::Empty), + derives: &[], + } + } +} + +#[derive(Copy, Debug, Clone)] +enum ImplTraitContext { + Existential, + Universal, +} + +#[derive(Debug)] +struct BindingError { + name: Symbol, + origin: BTreeSet<Span>, + target: BTreeSet<Span>, + could_be_path: bool, +} + +#[derive(Debug)] +enum ResolutionError<'a> { + /// Error E0401: can't use type or const parameters from outer item. + GenericParamsFromOuterItem(Res, HasGenericParams), + /// Error E0403: the name is already used for a type or const parameter in this generic + /// parameter list. + NameAlreadyUsedInParameterList(Symbol, Span), + /// Error E0407: method is not a member of trait. + MethodNotMemberOfTrait(Ident, String, Option<Symbol>), + /// Error E0437: type is not a member of trait. + TypeNotMemberOfTrait(Ident, String, Option<Symbol>), + /// Error E0438: const is not a member of trait. + ConstNotMemberOfTrait(Ident, String, Option<Symbol>), + /// Error E0408: variable `{}` is not bound in all patterns. + VariableNotBoundInPattern(BindingError, ParentScope<'a>), + /// Error E0409: variable `{}` is bound in inconsistent ways within the same match arm. + VariableBoundWithDifferentMode(Symbol, Span), + /// Error E0415: identifier is bound more than once in this parameter list. + IdentifierBoundMoreThanOnceInParameterList(Symbol), + /// Error E0416: identifier is bound more than once in the same pattern. + IdentifierBoundMoreThanOnceInSamePattern(Symbol), + /// Error E0426: use of undeclared label. + UndeclaredLabel { name: Symbol, suggestion: Option<LabelSuggestion> }, + /// Error E0429: `self` imports are only allowed within a `{ }` list. + SelfImportsOnlyAllowedWithin { root: bool, span_with_rename: Span }, + /// Error E0430: `self` import can only appear once in the list. + SelfImportCanOnlyAppearOnceInTheList, + /// Error E0431: `self` import can only appear in an import list with a non-empty prefix. + SelfImportOnlyInImportListWithNonEmptyPrefix, + /// Error E0433: failed to resolve. + FailedToResolve { + segment: Option<Symbol>, + label: String, + suggestion: Option<Suggestion>, + module: Option<ModuleOrUniformRoot<'a>>, + }, + /// Error E0434: can't capture dynamic environment in a fn item. + CannotCaptureDynamicEnvironmentInFnItem, + /// Error E0435: attempt to use a non-constant value in a constant. + AttemptToUseNonConstantValueInConstant( + Ident, + /* suggestion */ &'static str, + /* current */ &'static str, + ), + /// Error E0530: `X` bindings cannot shadow `Y`s. + BindingShadowsSomethingUnacceptable { + shadowing_binding: PatternSource, + name: Symbol, + participle: &'static str, + article: &'static str, + shadowed_binding: Res, + shadowed_binding_span: Span, + }, + /// Error E0128: generic parameters with a default cannot use forward-declared identifiers. + ForwardDeclaredGenericParam, + /// ERROR E0770: the type of const parameters must not depend on other generic parameters. + ParamInTyOfConstParam { name: Symbol, param_kind: Option<ParamKindInTyOfConstParam> }, + /// generic parameters must not be used inside const evaluations. + /// + /// This error is only emitted when using `min_const_generics`. + ParamInNonTrivialAnonConst { name: Symbol, param_kind: ParamKindInNonTrivialAnonConst }, + /// generic parameters must not be used inside enum discriminants. + /// + /// This error is emitted even with `generic_const_exprs`. + ParamInEnumDiscriminant { name: Symbol, param_kind: ParamKindInEnumDiscriminant }, + /// Error E0735: generic parameters with a default cannot use `Self` + SelfInGenericParamDefault, + /// Error E0767: use of unreachable label + UnreachableLabel { name: Symbol, definition_span: Span, suggestion: Option<LabelSuggestion> }, + /// Error E0323, E0324, E0325: mismatch between trait item and impl item. + TraitImplMismatch { + name: Symbol, + kind: &'static str, + trait_path: String, + trait_item_span: Span, + code: rustc_errors::DiagnosticId, + }, + /// Error E0201: multiple impl items for the same trait item. + TraitImplDuplicate { name: Symbol, trait_item_span: Span, old_span: Span }, + /// Inline asm `sym` operand must refer to a `fn` or `static`. + InvalidAsmSym, + /// `self` used instead of `Self` in a generic parameter + LowercaseSelf, +} + +enum VisResolutionError<'a> { + Relative2018(Span, &'a ast::Path), + AncestorOnly(Span), + FailedToResolve(Span, String, Option<Suggestion>), + ExpectedFound(Span, String, Res), + Indeterminate(Span), + ModuleOnly(Span), +} + +/// A minimal representation of a path segment. We use this in resolve because we synthesize 'path +/// segments' which don't have the rest of an AST or HIR `PathSegment`. +#[derive(Clone, Copy, Debug)] +struct Segment { + ident: Ident, + id: Option<NodeId>, + /// Signals whether this `PathSegment` has generic arguments. Used to avoid providing + /// nonsensical suggestions. + has_generic_args: bool, + /// Signals whether this `PathSegment` has lifetime arguments. + has_lifetime_args: bool, + args_span: Span, +} + +impl Segment { + fn from_path(path: &Path) -> Vec<Segment> { + path.segments.iter().map(|s| s.into()).collect() + } + + fn from_ident(ident: Ident) -> Segment { + Segment { + ident, + id: None, + has_generic_args: false, + has_lifetime_args: false, + args_span: DUMMY_SP, + } + } + + fn from_ident_and_id(ident: Ident, id: NodeId) -> Segment { + Segment { + ident, + id: Some(id), + has_generic_args: false, + has_lifetime_args: false, + args_span: DUMMY_SP, + } + } + + fn names_to_string(segments: &[Segment]) -> String { + names_to_string(&segments.iter().map(|seg| seg.ident.name).collect::<Vec<_>>()) + } +} + +impl<'a> From<&'a ast::PathSegment> for Segment { + fn from(seg: &'a ast::PathSegment) -> Segment { + let has_generic_args = seg.args.is_some(); + let (args_span, has_lifetime_args) = if let Some(args) = seg.args.as_deref() { + match args { + GenericArgs::AngleBracketed(args) => { + let found_lifetimes = args + .args + .iter() + .any(|arg| matches!(arg, AngleBracketedArg::Arg(GenericArg::Lifetime(_)))); + (args.span, found_lifetimes) + } + GenericArgs::Parenthesized(args) => (args.span, true), + } + } else { + (DUMMY_SP, false) + }; + Segment { + ident: seg.ident, + id: Some(seg.id), + has_generic_args, + has_lifetime_args, + args_span, + } + } +} + +/// An intermediate resolution result. +/// +/// This refers to the thing referred by a name. The difference between `Res` and `Item` is that +/// items are visible in their whole block, while `Res`es only from the place they are defined +/// forward. +#[derive(Debug)] +enum LexicalScopeBinding<'a> { + Item(NameBinding<'a>), + Res(Res), +} + +impl<'a> LexicalScopeBinding<'a> { + fn res(self) -> Res { + match self { + LexicalScopeBinding::Item(binding) => binding.res(), + LexicalScopeBinding::Res(res) => res, + } + } +} + +#[derive(Copy, Clone, PartialEq, Debug)] +enum ModuleOrUniformRoot<'a> { + /// Regular module. + Module(Module<'a>), + + /// Virtual module that denotes resolution in crate root with fallback to extern prelude. + CrateRootAndExternPrelude, + + /// Virtual module that denotes resolution in extern prelude. + /// Used for paths starting with `::` on 2018 edition. + ExternPrelude, + + /// Virtual module that denotes resolution in current scope. + /// Used only for resolving single-segment imports. The reason it exists is that import paths + /// are always split into two parts, the first of which should be some kind of module. + CurrentScope, +} + +#[derive(Debug)] +enum PathResult<'a> { + Module(ModuleOrUniformRoot<'a>), + NonModule(PartialRes), + Indeterminate, + Failed { + span: Span, + label: String, + suggestion: Option<Suggestion>, + is_error_from_last_segment: bool, + module: Option<ModuleOrUniformRoot<'a>>, + /// The segment name of target + segment_name: Symbol, + }, +} + +impl<'a> PathResult<'a> { + fn failed( + ident: Ident, + is_error_from_last_segment: bool, + finalize: bool, + module: Option<ModuleOrUniformRoot<'a>>, + label_and_suggestion: impl FnOnce() -> (String, Option<Suggestion>), + ) -> PathResult<'a> { + let (label, suggestion) = + if finalize { label_and_suggestion() } else { (String::new(), None) }; + PathResult::Failed { + span: ident.span, + segment_name: ident.name, + label, + suggestion, + is_error_from_last_segment, + module, + } + } +} + +#[derive(Debug)] +enum ModuleKind { + /// An anonymous module; e.g., just a block. + /// + /// ``` + /// fn main() { + /// fn f() {} // (1) + /// { // This is an anonymous module + /// f(); // This resolves to (2) as we are inside the block. + /// fn f() {} // (2) + /// } + /// f(); // Resolves to (1) + /// } + /// ``` + Block, + /// Any module with a name. + /// + /// This could be: + /// + /// * A normal module – either `mod from_file;` or `mod from_block { }` – + /// or the crate root (which is conceptually a top-level module). + /// Note that the crate root's [name][Self::name] will be [`kw::Empty`]. + /// * A trait or an enum (it implicitly contains associated types, methods and variant + /// constructors). + Def(DefKind, DefId, Symbol), +} + +impl ModuleKind { + /// Get name of the module. + fn name(&self) -> Option<Symbol> { + match self { + ModuleKind::Block => None, + ModuleKind::Def(.., name) => Some(*name), + } + } +} + +/// A key that identifies a binding in a given `Module`. +/// +/// Multiple bindings in the same module can have the same key (in a valid +/// program) if all but one of them come from glob imports. +#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)] +struct BindingKey { + /// The identifier for the binding, always the `normalize_to_macros_2_0` version of the + /// identifier. + ident: Ident, + ns: Namespace, + /// 0 if ident is not `_`, otherwise a value that's unique to the specific + /// `_` in the expanded AST that introduced this binding. + disambiguator: u32, +} + +impl BindingKey { + fn new(ident: Ident, ns: Namespace) -> Self { + let ident = ident.normalize_to_macros_2_0(); + BindingKey { ident, ns, disambiguator: 0 } + } +} + +type Resolutions<'a> = RefCell<FxIndexMap<BindingKey, &'a RefCell<NameResolution<'a>>>>; + +/// One node in the tree of modules. +/// +/// Note that a "module" in resolve is broader than a `mod` that you declare in Rust code. It may be one of these: +/// +/// * `mod` +/// * crate root (aka, top-level anonymous module) +/// * `enum` +/// * `trait` +/// * curly-braced block with statements +/// +/// You can use [`ModuleData::kind`] to determine the kind of module this is. +struct ModuleData<'a> { + /// The direct parent module (it may not be a `mod`, however). + parent: Option<Module<'a>>, + /// What kind of module this is, because this may not be a `mod`. + kind: ModuleKind, + + /// Mapping between names and their (possibly in-progress) resolutions in this module. + /// Resolutions in modules from other crates are not populated until accessed. + lazy_resolutions: Resolutions<'a>, + /// True if this is a module from other crate that needs to be populated on access. + populate_on_access: Cell<bool>, + + /// Macro invocations that can expand into items in this module. + unexpanded_invocations: RefCell<FxHashSet<LocalExpnId>>, + + /// Whether `#[no_implicit_prelude]` is active. + no_implicit_prelude: bool, + + glob_importers: RefCell<Vec<Import<'a>>>, + globs: RefCell<Vec<Import<'a>>>, + + /// Used to memoize the traits in this module for faster searches through all traits in scope. + traits: RefCell<Option<Box<[(Ident, NameBinding<'a>)]>>>, + + /// Span of the module itself. Used for error reporting. + span: Span, + + expansion: ExpnId, +} + +/// All modules are unique and allocated on a same arena, +/// so we can use referential equality to compare them. +#[derive(Clone, Copy, PartialEq, Eq, Hash)] +#[rustc_pass_by_value] +struct Module<'a>(Interned<'a, ModuleData<'a>>); + +impl<'a> ModuleData<'a> { + fn new( + parent: Option<Module<'a>>, + kind: ModuleKind, + expansion: ExpnId, + span: Span, + no_implicit_prelude: bool, + ) -> Self { + let is_foreign = match kind { + ModuleKind::Def(_, def_id, _) => !def_id.is_local(), + ModuleKind::Block => false, + }; + ModuleData { + parent, + kind, + lazy_resolutions: Default::default(), + populate_on_access: Cell::new(is_foreign), + unexpanded_invocations: Default::default(), + no_implicit_prelude, + glob_importers: RefCell::new(Vec::new()), + globs: RefCell::new(Vec::new()), + traits: RefCell::new(None), + span, + expansion, + } + } +} + +impl<'a> Module<'a> { + fn for_each_child<'tcx, R, F>(self, resolver: &mut R, mut f: F) + where + R: AsMut<Resolver<'a, 'tcx>>, + F: FnMut(&mut R, Ident, Namespace, NameBinding<'a>), + { + for (key, name_resolution) in resolver.as_mut().resolutions(self).borrow().iter() { + if let Some(binding) = name_resolution.borrow().binding { + f(resolver, key.ident, key.ns, binding); + } + } + } + + /// This modifies `self` in place. The traits will be stored in `self.traits`. + fn ensure_traits<'tcx, R>(self, resolver: &mut R) + where + R: AsMut<Resolver<'a, 'tcx>>, + { + let mut traits = self.traits.borrow_mut(); + if traits.is_none() { + let mut collected_traits = Vec::new(); + self.for_each_child(resolver, |_, name, ns, binding| { + if ns != TypeNS { + return; + } + if let Res::Def(DefKind::Trait | DefKind::TraitAlias, _) = binding.res() { + collected_traits.push((name, binding)) + } + }); + *traits = Some(collected_traits.into_boxed_slice()); + } + } + + fn res(self) -> Option<Res> { + match self.kind { + ModuleKind::Def(kind, def_id, _) => Some(Res::Def(kind, def_id)), + _ => None, + } + } + + // Public for rustdoc. + fn def_id(self) -> DefId { + self.opt_def_id().expect("`ModuleData::def_id` is called on a block module") + } + + fn opt_def_id(self) -> Option<DefId> { + match self.kind { + ModuleKind::Def(_, def_id, _) => Some(def_id), + _ => None, + } + } + + // `self` resolves to the first module ancestor that `is_normal`. + fn is_normal(self) -> bool { + matches!(self.kind, ModuleKind::Def(DefKind::Mod, _, _)) + } + + fn is_trait(self) -> bool { + matches!(self.kind, ModuleKind::Def(DefKind::Trait, _, _)) + } + + fn nearest_item_scope(self) -> Module<'a> { + match self.kind { + ModuleKind::Def(DefKind::Enum | DefKind::Trait, ..) => { + self.parent.expect("enum or trait module without a parent") + } + _ => self, + } + } + + /// The [`DefId`] of the nearest `mod` item ancestor (which may be this module). + /// This may be the crate root. + fn nearest_parent_mod(self) -> DefId { + match self.kind { + ModuleKind::Def(DefKind::Mod, def_id, _) => def_id, + _ => self.parent.expect("non-root module without parent").nearest_parent_mod(), + } + } + + fn is_ancestor_of(self, mut other: Self) -> bool { + while self != other { + if let Some(parent) = other.parent { + other = parent; + } else { + return false; + } + } + true + } +} + +impl<'a> std::ops::Deref for Module<'a> { + type Target = ModuleData<'a>; + + fn deref(&self) -> &Self::Target { + &self.0 + } +} + +impl<'a> fmt::Debug for Module<'a> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!(f, "{:?}", self.res()) + } +} + +/// Records a possibly-private value, type, or module definition. +#[derive(Clone, Debug)] +struct NameBindingData<'a> { + kind: NameBindingKind<'a>, + ambiguity: Option<(NameBinding<'a>, AmbiguityKind)>, + warn_ambiguity: bool, + expansion: LocalExpnId, + span: Span, + vis: ty::Visibility<DefId>, +} + +/// All name bindings are unique and allocated on a same arena, +/// so we can use referential equality to compare them. +type NameBinding<'a> = Interned<'a, NameBindingData<'a>>; + +trait ToNameBinding<'a> { + fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> NameBinding<'a>; +} + +impl<'a> ToNameBinding<'a> for NameBinding<'a> { + fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> NameBinding<'a> { + self + } +} + +#[derive(Clone, Debug)] +enum NameBindingKind<'a> { + Res(Res), + Module(Module<'a>), + Import { binding: NameBinding<'a>, import: Import<'a>, used: Cell<bool> }, +} + +impl<'a> NameBindingKind<'a> { + /// Is this a name binding of an import? + fn is_import(&self) -> bool { + matches!(*self, NameBindingKind::Import { .. }) + } +} + +#[derive(Debug)] +struct PrivacyError<'a> { + ident: Ident, + binding: NameBinding<'a>, + dedup_span: Span, + outermost_res: Option<(Res, Ident)>, + parent_scope: ParentScope<'a>, +} + +#[derive(Debug)] +struct UseError<'a> { + err: DiagnosticBuilder<'a>, + /// Candidates which user could `use` to access the missing type. + candidates: Vec<ImportSuggestion>, + /// The `DefId` of the module to place the use-statements in. + def_id: DefId, + /// Whether the diagnostic should say "instead" (as in `consider importing ... instead`). + instead: bool, + /// Extra free-form suggestion. + suggestion: Option<(Span, &'static str, String, Applicability)>, + /// Path `Segment`s at the place of use that failed. Used for accurate suggestion after telling + /// the user to import the item directly. + path: Vec<Segment>, + /// Whether the expected source is a call + is_call: bool, +} + +#[derive(Clone, Copy, PartialEq, Debug)] +enum AmbiguityKind { + BuiltinAttr, + DeriveHelper, + MacroRulesVsModularized, + GlobVsOuter, + GlobVsGlob, + GlobVsExpanded, + MoreExpandedVsOuter, +} + +impl AmbiguityKind { + fn descr(self) -> &'static str { + match self { + AmbiguityKind::BuiltinAttr => "a name conflict with a builtin attribute", + AmbiguityKind::DeriveHelper => "a name conflict with a derive helper attribute", + AmbiguityKind::MacroRulesVsModularized => { + "a conflict between a `macro_rules` name and a non-`macro_rules` name from another module" + } + AmbiguityKind::GlobVsOuter => { + "a conflict between a name from a glob import and an outer scope during import or macro resolution" + } + AmbiguityKind::GlobVsGlob => "multiple glob imports of a name in the same module", + AmbiguityKind::GlobVsExpanded => { + "a conflict between a name from a glob import and a macro-expanded name in the same module during import or macro resolution" + } + AmbiguityKind::MoreExpandedVsOuter => { + "a conflict between a macro-expanded name and a less macro-expanded name from outer scope during import or macro resolution" + } + } + } +} + +/// Miscellaneous bits of metadata for better ambiguity error reporting. +#[derive(Clone, Copy, PartialEq)] +enum AmbiguityErrorMisc { + SuggestCrate, + SuggestSelf, + FromPrelude, + None, +} + +struct AmbiguityError<'a> { + kind: AmbiguityKind, + ident: Ident, + b1: NameBinding<'a>, + b2: NameBinding<'a>, + misc1: AmbiguityErrorMisc, + misc2: AmbiguityErrorMisc, + warning: bool, +} + +impl<'a> NameBindingData<'a> { + fn module(&self) -> Option<Module<'a>> { + match self.kind { + NameBindingKind::Module(module) => Some(module), + NameBindingKind::Import { binding, .. } => binding.module(), + _ => None, + } + } + + fn res(&self) -> Res { + match self.kind { + NameBindingKind::Res(res) => res, + NameBindingKind::Module(module) => module.res().unwrap(), + NameBindingKind::Import { binding, .. } => binding.res(), + } + } + + fn is_ambiguity(&self) -> bool { + self.ambiguity.is_some() + || match self.kind { + NameBindingKind::Import { binding, .. } => binding.is_ambiguity(), + _ => false, + } + } + + fn is_warn_ambiguity(&self) -> bool { + self.warn_ambiguity + || match self.kind { + NameBindingKind::Import { binding, .. } => binding.is_warn_ambiguity(), + _ => false, + } + } + + fn is_possibly_imported_variant(&self) -> bool { + match self.kind { + NameBindingKind::Import { binding, .. } => binding.is_possibly_imported_variant(), + NameBindingKind::Res(Res::Def( + DefKind::Variant | DefKind::Ctor(CtorOf::Variant, ..), + _, + )) => true, + NameBindingKind::Res(..) | NameBindingKind::Module(..) => false, + } + } + + fn is_extern_crate(&self) -> bool { + match self.kind { + NameBindingKind::Import { import, .. } => { + matches!(import.kind, ImportKind::ExternCrate { .. }) + } + NameBindingKind::Module(module) + if let ModuleKind::Def(DefKind::Mod, def_id, _) = module.kind => + { + def_id.is_crate_root() + } + _ => false, + } + } + + fn is_import(&self) -> bool { + matches!(self.kind, NameBindingKind::Import { .. }) + } + + /// The binding introduced by `#[macro_export] macro_rules` is a public import, but it might + /// not be perceived as such by users, so treat it as a non-import in some diagnostics. + fn is_import_user_facing(&self) -> bool { + matches!(self.kind, NameBindingKind::Import { import, .. } + if !matches!(import.kind, ImportKind::MacroExport)) + } + + fn is_glob_import(&self) -> bool { + match self.kind { + NameBindingKind::Import { import, .. } => import.is_glob(), + _ => false, + } + } + + fn is_importable(&self) -> bool { + !matches!( + self.res(), + Res::Def(DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy, _) + ) + } + + fn macro_kind(&self) -> Option<MacroKind> { + self.res().macro_kind() + } + + // Suppose that we resolved macro invocation with `invoc_parent_expansion` to binding `binding` + // at some expansion round `max(invoc, binding)` when they both emerged from macros. + // Then this function returns `true` if `self` may emerge from a macro *after* that + // in some later round and screw up our previously found resolution. + // See more detailed explanation in + // https://github.com/rust-lang/rust/pull/53778#issuecomment-419224049 + fn may_appear_after( + &self, + invoc_parent_expansion: LocalExpnId, + binding: NameBinding<'_>, + ) -> bool { + // self > max(invoc, binding) => !(self <= invoc || self <= binding) + // Expansions are partially ordered, so "may appear after" is an inversion of + // "certainly appears before or simultaneously" and includes unordered cases. + let self_parent_expansion = self.expansion; + let other_parent_expansion = binding.expansion; + let certainly_before_other_or_simultaneously = + other_parent_expansion.is_descendant_of(self_parent_expansion); + let certainly_before_invoc_or_simultaneously = + invoc_parent_expansion.is_descendant_of(self_parent_expansion); + !(certainly_before_other_or_simultaneously || certainly_before_invoc_or_simultaneously) + } + + // Its purpose is to postpone the determination of a single binding because + // we can't predict whether it will be overwritten by recently expanded macros. + // FIXME: How can we integrate it with the `update_resolution`? + fn determined(&self) -> bool { + match &self.kind { + NameBindingKind::Import { binding, import, .. } if import.is_glob() => { + import.parent_scope.module.unexpanded_invocations.borrow().is_empty() + && binding.determined() + } + _ => true, + } + } +} + +#[derive(Default, Clone)] +struct ExternPreludeEntry<'a> { + binding: Option<NameBinding<'a>>, + introduced_by_item: bool, +} + +impl ExternPreludeEntry<'_> { + fn is_import(&self) -> bool { + self.binding.is_some_and(|binding| binding.is_import()) + } +} + +/// Used for better errors for E0773 +enum BuiltinMacroState { + NotYetSeen(SyntaxExtensionKind), + AlreadySeen(Span), +} + +struct DeriveData { + resolutions: DeriveResolutions, + helper_attrs: Vec<(usize, Ident)>, + has_derive_copy: bool, +} + +#[derive(Clone)] +struct MacroData { + ext: Lrc<SyntaxExtension>, + rule_spans: Vec<(usize, Span)>, + macro_rules: bool, +} + +impl MacroData { + fn new(ext: Lrc<SyntaxExtension>) -> MacroData { + MacroData { ext, rule_spans: Vec::new(), macro_rules: false } + } +} + +/// The main resolver class. +/// +/// This is the visitor that walks the whole crate. +pub struct Resolver<'a, 'tcx> { + tcx: TyCtxt<'tcx>, + + /// Item with a given `LocalDefId` was defined during macro expansion with ID `ExpnId`. + expn_that_defined: FxHashMap<LocalDefId, ExpnId>, + + graph_root: Module<'a>, + + prelude: Option<Module<'a>>, + extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'a>>, + + /// N.B., this is used only for better diagnostics, not name resolution itself. + has_self: LocalDefIdSet, + field_def_ids: LocalDefIdMap<&'tcx [DefId]>, + + /// Span of the privacy modifier in fields of an item `DefId` accessible with dot syntax. + /// Used for hints during error reporting. + field_visibility_spans: FxHashMap<DefId, Vec<Span>>, + + /// All imports known to succeed or fail. + determined_imports: Vec<Import<'a>>, + + /// All non-determined imports. + indeterminate_imports: Vec<Import<'a>>, + + // Spans for local variables found during pattern resolution. + // Used for suggestions during error reporting. + pat_span_map: NodeMap<Span>, + + /// Resolutions for nodes that have a single resolution. + partial_res_map: NodeMap<PartialRes>, + /// Resolutions for import nodes, which have multiple resolutions in different namespaces. + import_res_map: NodeMap<PerNS<Option<Res>>>, + /// Resolutions for labels (node IDs of their corresponding blocks or loops). + label_res_map: NodeMap<NodeId>, + /// Resolutions for lifetimes. + lifetimes_res_map: NodeMap<LifetimeRes>, + /// Lifetime parameters that lowering will have to introduce. + extra_lifetime_params_map: NodeMap<Vec<(Ident, NodeId, LifetimeRes)>>, + + /// `CrateNum` resolutions of `extern crate` items. + extern_crate_map: FxHashMap<LocalDefId, CrateNum>, + module_children: LocalDefIdMap<Vec<ModChild>>, + trait_map: NodeMap<Vec<TraitCandidate>>, + + /// A map from nodes to anonymous modules. + /// Anonymous modules are pseudo-modules that are implicitly created around items + /// contained within blocks. + /// + /// For example, if we have this: + /// + /// fn f() { + /// fn g() { + /// ... + /// } + /// } + /// + /// There will be an anonymous module created around `g` with the ID of the + /// entry block for `f`. + block_map: NodeMap<Module<'a>>, + /// A fake module that contains no definition and no prelude. Used so that + /// some AST passes can generate identifiers that only resolve to local or + /// language items. + empty_module: Module<'a>, + module_map: FxHashMap<DefId, Module<'a>>, + binding_parent_modules: FxHashMap<NameBinding<'a>, Module<'a>>, + + underscore_disambiguator: u32, + + /// Maps glob imports to the names of items actually imported. + glob_map: FxHashMap<LocalDefId, FxHashSet<Symbol>>, + visibilities_for_hashing: Vec<(LocalDefId, ty::Visibility)>, + used_imports: FxHashSet<NodeId>, + maybe_unused_trait_imports: FxIndexSet<LocalDefId>, + + /// Privacy errors are delayed until the end in order to deduplicate them. + privacy_errors: Vec<PrivacyError<'a>>, + /// Ambiguity errors are delayed for deduplication. + ambiguity_errors: Vec<AmbiguityError<'a>>, + /// `use` injections are delayed for better placement and deduplication. + use_injections: Vec<UseError<'tcx>>, + /// Crate-local macro expanded `macro_export` referred to by a module-relative path. + macro_expanded_macro_export_errors: BTreeSet<(Span, Span)>, + + arenas: &'a ResolverArenas<'a>, + dummy_binding: NameBinding<'a>, + builtin_types_bindings: FxHashMap<Symbol, NameBinding<'a>>, + builtin_attrs_bindings: FxHashMap<Symbol, NameBinding<'a>>, + registered_tool_bindings: FxHashMap<Ident, NameBinding<'a>>, + /// Binding for implicitly declared names that come with a module, + /// like `self` (not yet used), or `crate`/`$crate` (for root modules). + module_self_bindings: FxHashMap<Module<'a>, NameBinding<'a>>, + + used_extern_options: FxHashSet<Symbol>, + macro_names: FxHashSet<Ident>, + builtin_macros: FxHashMap<Symbol, BuiltinMacroState>, + registered_tools: &'tcx RegisteredTools, + macro_use_prelude: FxHashMap<Symbol, NameBinding<'a>>, + macro_map: FxHashMap<DefId, MacroData>, + dummy_ext_bang: Lrc<SyntaxExtension>, + dummy_ext_derive: Lrc<SyntaxExtension>, + non_macro_attr: MacroData, + local_macro_def_scopes: FxHashMap<LocalDefId, Module<'a>>, + ast_transform_scopes: FxHashMap<LocalExpnId, Module<'a>>, + unused_macros: FxHashMap<LocalDefId, (NodeId, Ident)>, + unused_macro_rules: FxHashMap<(LocalDefId, usize), (Ident, Span)>, + proc_macro_stubs: FxHashSet<LocalDefId>, + /// Traces collected during macro resolution and validated when it's complete. + single_segment_macro_resolutions: + Vec<(Ident, MacroKind, ParentScope<'a>, Option<NameBinding<'a>>)>, + multi_segment_macro_resolutions: + Vec<(Vec<Segment>, Span, MacroKind, ParentScope<'a>, Option<Res>)>, + builtin_attrs: Vec<(Ident, ParentScope<'a>)>, + /// `derive(Copy)` marks items they are applied to so they are treated specially later. + /// Derive macros cannot modify the item themselves and have to store the markers in the global + /// context, so they attach the markers to derive container IDs using this resolver table. + containers_deriving_copy: FxHashSet<LocalExpnId>, + /// Parent scopes in which the macros were invoked. + /// FIXME: `derives` are missing in these parent scopes and need to be taken from elsewhere. + invocation_parent_scopes: FxHashMap<LocalExpnId, ParentScope<'a>>, + /// `macro_rules` scopes *produced* by expanding the macro invocations, + /// include all the `macro_rules` items and other invocations generated by them. + output_macro_rules_scopes: FxHashMap<LocalExpnId, MacroRulesScopeRef<'a>>, + /// `macro_rules` scopes produced by `macro_rules` item definitions. + macro_rules_scopes: FxHashMap<LocalDefId, MacroRulesScopeRef<'a>>, + /// Helper attributes that are in scope for the given expansion. + helper_attrs: FxHashMap<LocalExpnId, Vec<(Ident, NameBinding<'a>)>>, + /// Ready or in-progress results of resolving paths inside the `#[derive(...)]` attribute + /// with the given `ExpnId`. + derive_data: FxHashMap<LocalExpnId, DeriveData>, + + /// Avoid duplicated errors for "name already defined". + name_already_seen: FxHashMap<Symbol, Span>, + + potentially_unused_imports: Vec<Import<'a>>, + + /// Table for mapping struct IDs into struct constructor IDs, + /// it's not used during normal resolution, only for better error reporting. + /// Also includes of list of each fields visibility + struct_constructors: LocalDefIdMap<(Res, ty::Visibility<DefId>, Vec<ty::Visibility<DefId>>)>, + + /// Features declared for this crate. + declared_features: FxHashSet<Symbol>, + + lint_buffer: LintBuffer, + + next_node_id: NodeId, + + node_id_to_def_id: NodeMap<LocalDefId>, + def_id_to_node_id: IndexVec<LocalDefId, ast::NodeId>, + + /// Indices of unnamed struct or variant fields with unresolved attributes. + placeholder_field_indices: FxHashMap<NodeId, usize>, + /// When collecting definitions from an AST fragment produced by a macro invocation `ExpnId` + /// we know what parent node that fragment should be attached to thanks to this table, + /// and how the `impl Trait` fragments were introduced. + invocation_parents: FxHashMap<LocalExpnId, (LocalDefId, ImplTraitContext)>, + + /// Some way to know that we are in a *trait* impl in `visit_assoc_item`. + /// FIXME: Replace with a more general AST map (together with some other fields). + trait_impl_items: FxHashSet<LocalDefId>, + + legacy_const_generic_args: FxHashMap<DefId, Option<Vec<usize>>>, + /// Amount of lifetime parameters for each item in the crate. + item_generics_num_lifetimes: FxHashMap<LocalDefId, usize>, + /// Amount of parameters for each function in the crate. + fn_parameter_counts: LocalDefIdMap<usize>, + + main_def: Option<MainDefinition>, + trait_impls: FxIndexMap<DefId, Vec<LocalDefId>>, + /// A list of proc macro LocalDefIds, written out in the order in which + /// they are declared in the static array generated by proc_macro_harness. + proc_macros: Vec<NodeId>, + confused_type_with_std_module: FxHashMap<Span, Span>, + /// Whether lifetime elision was successful. + lifetime_elision_allowed: FxHashSet<NodeId>, + + /// Names of items that were stripped out via cfg with their corresponding cfg meta item. + stripped_cfg_items: Vec<StrippedCfgItem<NodeId>>, + + effective_visibilities: EffectiveVisibilities, + doc_link_resolutions: FxHashMap<LocalDefId, DocLinkResMap>, + doc_link_traits_in_scope: FxHashMap<LocalDefId, Vec<DefId>>, + all_macro_rules: FxHashMap<Symbol, Res>, +} + +/// Nothing really interesting here; it just provides memory for the rest of the crate. +#[derive(Default)] +pub struct ResolverArenas<'a> { + modules: TypedArena<ModuleData<'a>>, + local_modules: RefCell<Vec<Module<'a>>>, + imports: TypedArena<ImportData<'a>>, + name_resolutions: TypedArena<RefCell<NameResolution<'a>>>, + ast_paths: TypedArena<ast::Path>, + dropless: DroplessArena, +} + +impl<'a> ResolverArenas<'a> { + fn new_module( + &'a self, + parent: Option<Module<'a>>, + kind: ModuleKind, + expn_id: ExpnId, + span: Span, + no_implicit_prelude: bool, + module_map: &mut FxHashMap<DefId, Module<'a>>, + module_self_bindings: &mut FxHashMap<Module<'a>, NameBinding<'a>>, + ) -> Module<'a> { + let module = Module(Interned::new_unchecked(self.modules.alloc(ModuleData::new( + parent, + kind, + expn_id, + span, + no_implicit_prelude, + )))); + let def_id = module.opt_def_id(); + if def_id.map_or(true, |def_id| def_id.is_local()) { + self.local_modules.borrow_mut().push(module); + } + if let Some(def_id) = def_id { + module_map.insert(def_id, module); + let vis = ty::Visibility::<DefId>::Public; + let binding = (module, vis, module.span, LocalExpnId::ROOT).to_name_binding(self); + module_self_bindings.insert(module, binding); + } + module + } + fn local_modules(&'a self) -> std::cell::Ref<'a, Vec<Module<'a>>> { + self.local_modules.borrow() + } + fn alloc_name_binding(&'a self, name_binding: NameBindingData<'a>) -> NameBinding<'a> { + Interned::new_unchecked(self.dropless.alloc(name_binding)) + } + fn alloc_import(&'a self, import: ImportData<'a>) -> Import<'a> { + Interned::new_unchecked(self.imports.alloc(import)) + } + fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> { + self.name_resolutions.alloc(Default::default()) + } + fn alloc_macro_rules_scope(&'a self, scope: MacroRulesScope<'a>) -> MacroRulesScopeRef<'a> { + Interned::new_unchecked(self.dropless.alloc(Cell::new(scope))) + } + fn alloc_macro_rules_binding( + &'a self, + binding: MacroRulesBinding<'a>, + ) -> &'a MacroRulesBinding<'a> { + self.dropless.alloc(binding) + } + fn alloc_ast_paths(&'a self, paths: &[ast::Path]) -> &'a [ast::Path] { + self.ast_paths.alloc_from_iter(paths.iter().cloned()) + } + fn alloc_pattern_spans(&'a self, spans: impl Iterator<Item = Span>) -> &'a [Span] { + self.dropless.alloc_from_iter(spans) + } +} + +impl<'a, 'tcx> AsMut<Resolver<'a, 'tcx>> for Resolver<'a, 'tcx> { + fn as_mut(&mut self) -> &mut Resolver<'a, 'tcx> { + self + } +} + +impl<'tcx> Resolver<'_, 'tcx> { + fn opt_local_def_id(&self, node: NodeId) -> Option<LocalDefId> { + self.node_id_to_def_id.get(&node).copied() + } + + fn local_def_id(&self, node: NodeId) -> LocalDefId { + self.opt_local_def_id(node).unwrap_or_else(|| panic!("no entry for node id: `{node:?}`")) + } + + /// Adds a definition with a parent definition. + fn create_def( + &mut self, + parent: LocalDefId, + node_id: ast::NodeId, + name: Symbol, + def_kind: DefKind, + expn_id: ExpnId, + span: Span, + ) -> LocalDefId { + let data = def_kind.def_path_data(name); + assert!( + !self.node_id_to_def_id.contains_key(&node_id), + "adding a def'n for node-id {:?} and data {:?} but a previous def'n exists: {:?}", + node_id, + data, + self.tcx.definitions_untracked().def_key(self.node_id_to_def_id[&node_id]), + ); + + // FIXME: remove `def_span` body, pass in the right spans here and call `tcx.at().create_def()` + let def_id = self.tcx.create_def(parent, name, def_kind); + + // Create the definition. + if expn_id != ExpnId::root() { + self.expn_that_defined.insert(def_id, expn_id); + } + + // A relative span's parent must be an absolute span. + debug_assert_eq!(span.data_untracked().parent, None); + let _id = self.tcx.untracked().source_span.push(span); + debug_assert_eq!(_id, def_id); + + // Some things for which we allocate `LocalDefId`s don't correspond to + // anything in the AST, so they don't have a `NodeId`. For these cases + // we don't need a mapping from `NodeId` to `LocalDefId`. + if node_id != ast::DUMMY_NODE_ID { + debug!("create_def: def_id_to_node_id[{:?}] <-> {:?}", def_id, node_id); + self.node_id_to_def_id.insert(node_id, def_id); + } + assert_eq!(self.def_id_to_node_id.push(node_id), def_id); + + def_id + } + + fn item_generics_num_lifetimes(&self, def_id: DefId) -> usize { + if let Some(def_id) = def_id.as_local() { + self.item_generics_num_lifetimes[&def_id] + } else { + self.tcx.generics_of(def_id).own_counts().lifetimes + } + } + + pub fn tcx(&self) -> TyCtxt<'tcx> { + self.tcx + } +} + +impl<'a, 'tcx> Resolver<'a, 'tcx> { + pub fn new( + tcx: TyCtxt<'tcx>, + attrs: &[ast::Attribute], + crate_span: Span, + arenas: &'a ResolverArenas<'a>, + ) -> Resolver<'a, 'tcx> { + let root_def_id = CRATE_DEF_ID.to_def_id(); + let mut module_map = FxHashMap::default(); + let mut module_self_bindings = FxHashMap::default(); + let graph_root = arenas.new_module( + None, + ModuleKind::Def(DefKind::Mod, root_def_id, kw::Empty), + ExpnId::root(), + crate_span, + attr::contains_name(attrs, sym::no_implicit_prelude), + &mut module_map, + &mut module_self_bindings, + ); + let empty_module = arenas.new_module( + None, + ModuleKind::Def(DefKind::Mod, root_def_id, kw::Empty), + ExpnId::root(), + DUMMY_SP, + true, + &mut FxHashMap::default(), + &mut FxHashMap::default(), + ); + + let mut def_id_to_node_id = IndexVec::default(); + assert_eq!(def_id_to_node_id.push(CRATE_NODE_ID), CRATE_DEF_ID); + let mut node_id_to_def_id = NodeMap::default(); + node_id_to_def_id.insert(CRATE_NODE_ID, CRATE_DEF_ID); + + let mut invocation_parents = FxHashMap::default(); + invocation_parents.insert(LocalExpnId::ROOT, (CRATE_DEF_ID, ImplTraitContext::Existential)); + + let mut extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'_>> = tcx + .sess + .opts + .externs + .iter() + .filter(|(_, entry)| entry.add_prelude) + .map(|(name, _)| (Ident::from_str(name), Default::default())) + .collect(); + + if !attr::contains_name(attrs, sym::no_core) { + extern_prelude.insert(Ident::with_dummy_span(sym::core), Default::default()); + if !attr::contains_name(attrs, sym::no_std) { + extern_prelude.insert(Ident::with_dummy_span(sym::std), Default::default()); + } + } + + let registered_tools = tcx.registered_tools(()); + + let features = tcx.features(); + let pub_vis = ty::Visibility::<DefId>::Public; + let edition = tcx.sess.edition(); + + let mut resolver = Resolver { + tcx, + + expn_that_defined: Default::default(), + + // The outermost module has def ID 0; this is not reflected in the + // AST. + graph_root, + prelude: None, + extern_prelude, + + has_self: Default::default(), + field_def_ids: Default::default(), + field_visibility_spans: FxHashMap::default(), + + determined_imports: Vec::new(), + indeterminate_imports: Vec::new(), + + pat_span_map: Default::default(), + partial_res_map: Default::default(), + import_res_map: Default::default(), + label_res_map: Default::default(), + lifetimes_res_map: Default::default(), + extra_lifetime_params_map: Default::default(), + extern_crate_map: Default::default(), + module_children: Default::default(), + trait_map: NodeMap::default(), + underscore_disambiguator: 0, + empty_module, + module_map, + block_map: Default::default(), + binding_parent_modules: FxHashMap::default(), + ast_transform_scopes: FxHashMap::default(), + + glob_map: Default::default(), + visibilities_for_hashing: Default::default(), + used_imports: FxHashSet::default(), + maybe_unused_trait_imports: Default::default(), + + privacy_errors: Vec::new(), + ambiguity_errors: Vec::new(), + use_injections: Vec::new(), + macro_expanded_macro_export_errors: BTreeSet::new(), + + arenas, + dummy_binding: (Res::Err, pub_vis, DUMMY_SP, LocalExpnId::ROOT).to_name_binding(arenas), + builtin_types_bindings: PrimTy::ALL + .iter() + .map(|prim_ty| { + let binding = (Res::PrimTy(*prim_ty), pub_vis, DUMMY_SP, LocalExpnId::ROOT) + .to_name_binding(arenas); + (prim_ty.name(), binding) + }) + .collect(), + builtin_attrs_bindings: BUILTIN_ATTRIBUTES + .iter() + .map(|builtin_attr| { + let res = Res::NonMacroAttr(NonMacroAttrKind::Builtin(builtin_attr.name)); + let binding = + (res, pub_vis, DUMMY_SP, LocalExpnId::ROOT).to_name_binding(arenas); + (builtin_attr.name, binding) + }) + .collect(), + registered_tool_bindings: registered_tools + .iter() + .map(|ident| { + let binding = (Res::ToolMod, pub_vis, ident.span, LocalExpnId::ROOT) + .to_name_binding(arenas); + (*ident, binding) + }) + .collect(), + module_self_bindings, + + used_extern_options: Default::default(), + macro_names: FxHashSet::default(), + builtin_macros: Default::default(), + registered_tools, + macro_use_prelude: FxHashMap::default(), + macro_map: FxHashMap::default(), + dummy_ext_bang: Lrc::new(SyntaxExtension::dummy_bang(edition)), + dummy_ext_derive: Lrc::new(SyntaxExtension::dummy_derive(edition)), + non_macro_attr: MacroData::new(Lrc::new(SyntaxExtension::non_macro_attr(edition))), + invocation_parent_scopes: Default::default(), + output_macro_rules_scopes: Default::default(), + macro_rules_scopes: Default::default(), + helper_attrs: Default::default(), + derive_data: Default::default(), + local_macro_def_scopes: FxHashMap::default(), + name_already_seen: FxHashMap::default(), + potentially_unused_imports: Vec::new(), + struct_constructors: Default::default(), + unused_macros: Default::default(), + unused_macro_rules: Default::default(), + proc_macro_stubs: Default::default(), + single_segment_macro_resolutions: Default::default(), + multi_segment_macro_resolutions: Default::default(), + builtin_attrs: Default::default(), + containers_deriving_copy: Default::default(), + declared_features: features.declared_features.clone(), + lint_buffer: LintBuffer::default(), + next_node_id: CRATE_NODE_ID, + node_id_to_def_id, + def_id_to_node_id, + placeholder_field_indices: Default::default(), + invocation_parents, + trait_impl_items: Default::default(), + legacy_const_generic_args: Default::default(), + item_generics_num_lifetimes: Default::default(), + main_def: Default::default(), + trait_impls: Default::default(), + proc_macros: Default::default(), + confused_type_with_std_module: Default::default(), + lifetime_elision_allowed: Default::default(), + stripped_cfg_items: Default::default(), + effective_visibilities: Default::default(), + doc_link_resolutions: Default::default(), + doc_link_traits_in_scope: Default::default(), + all_macro_rules: Default::default(), + fn_parameter_counts: Default::default(), + }; + + let root_parent_scope = ParentScope::module(graph_root, &resolver); + resolver.invocation_parent_scopes.insert(LocalExpnId::ROOT, root_parent_scope); + resolver.feed_visibility(CRATE_DEF_ID, ty::Visibility::Public); + + resolver + } + + fn new_module( + &mut self, + parent: Option<Module<'a>>, + kind: ModuleKind, + expn_id: ExpnId, + span: Span, + no_implicit_prelude: bool, + ) -> Module<'a> { + let module_map = &mut self.module_map; + let module_self_bindings = &mut self.module_self_bindings; + self.arenas.new_module( + parent, + kind, + expn_id, + span, + no_implicit_prelude, + module_map, + module_self_bindings, + ) + } + + fn next_node_id(&mut self) -> NodeId { + let start = self.next_node_id; + let next = start.as_u32().checked_add(1).expect("input too large; ran out of NodeIds"); + self.next_node_id = ast::NodeId::from_u32(next); + start + } + + fn next_node_ids(&mut self, count: usize) -> std::ops::Range<NodeId> { + let start = self.next_node_id; + let end = start.as_usize().checked_add(count).expect("input too large; ran out of NodeIds"); + self.next_node_id = ast::NodeId::from_usize(end); + start..self.next_node_id + } + + pub fn lint_buffer(&mut self) -> &mut LintBuffer { + &mut self.lint_buffer + } + + pub fn arenas() -> ResolverArenas<'a> { + Default::default() + } + + fn feed_visibility(&mut self, def_id: LocalDefId, vis: ty::Visibility) { + self.tcx.feed_local_def_id(def_id).visibility(vis.to_def_id()); + self.visibilities_for_hashing.push((def_id, vis)); + } + + pub fn into_outputs(self) -> ResolverOutputs { + let proc_macros = self.proc_macros.iter().map(|id| self.local_def_id(*id)).collect(); + let expn_that_defined = self.expn_that_defined; + let extern_crate_map = self.extern_crate_map; + let maybe_unused_trait_imports = self.maybe_unused_trait_imports; + let glob_map = self.glob_map; + let main_def = self.main_def; + let confused_type_with_std_module = self.confused_type_with_std_module; + let effective_visibilities = self.effective_visibilities; + + self.tcx.feed_local_crate().stripped_cfg_items(self.tcx.arena.alloc_from_iter( + self.stripped_cfg_items.into_iter().filter_map(|item| { + let parent_module = self.node_id_to_def_id.get(&item.parent_module)?.to_def_id(); + Some(StrippedCfgItem { parent_module, name: item.name, cfg: item.cfg }) + }), + )); + + let global_ctxt = ResolverGlobalCtxt { + expn_that_defined, + visibilities_for_hashing: self.visibilities_for_hashing, + effective_visibilities, + extern_crate_map, + module_children: self.module_children, + glob_map, + maybe_unused_trait_imports, + main_def, + trait_impls: self.trait_impls, + proc_macros, + confused_type_with_std_module, + doc_link_resolutions: self.doc_link_resolutions, + doc_link_traits_in_scope: self.doc_link_traits_in_scope, + all_macro_rules: self.all_macro_rules, + }; + let ast_lowering = ty::ResolverAstLowering { + legacy_const_generic_args: self.legacy_const_generic_args, + partial_res_map: self.partial_res_map, + import_res_map: self.import_res_map, + label_res_map: self.label_res_map, + lifetimes_res_map: self.lifetimes_res_map, + extra_lifetime_params_map: self.extra_lifetime_params_map, + next_node_id: self.next_node_id, + node_id_to_def_id: self.node_id_to_def_id, + def_id_to_node_id: self.def_id_to_node_id, + trait_map: self.trait_map, + lifetime_elision_allowed: self.lifetime_elision_allowed, + lint_buffer: Steal::new(self.lint_buffer), + has_self: self.has_self, + fn_parameter_counts: self.fn_parameter_counts, + }; + ResolverOutputs { global_ctxt, ast_lowering } + } + + fn create_stable_hashing_context(&self) -> StableHashingContext<'_> { + StableHashingContext::new(self.tcx.sess, self.tcx.untracked()) + } + + fn crate_loader<T>(&mut self, f: impl FnOnce(&mut CrateLoader<'_, '_>) -> T) -> T { + f(&mut CrateLoader::new( + self.tcx, + &mut CStore::from_tcx_mut(self.tcx), + &mut self.used_extern_options, + )) + } + + fn cstore(&self) -> FreezeReadGuard<'_, CStore> { + CStore::from_tcx(self.tcx) + } + + fn dummy_ext(&self, macro_kind: MacroKind) -> Lrc<SyntaxExtension> { + match macro_kind { + MacroKind::Bang => self.dummy_ext_bang.clone(), + MacroKind::Derive => self.dummy_ext_derive.clone(), + MacroKind::Attr => self.non_macro_attr.ext.clone(), + } + } + + /// Runs the function on each namespace. + fn per_ns<F: FnMut(&mut Self, Namespace)>(&mut self, mut f: F) { + f(self, TypeNS); + f(self, ValueNS); + f(self, MacroNS); + } + + fn is_builtin_macro(&mut self, res: Res) -> bool { + self.get_macro(res).is_some_and(|macro_data| macro_data.ext.builtin_name.is_some()) + } + + fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId { + loop { + match ctxt.outer_expn_data().macro_def_id { + Some(def_id) => return def_id, + None => ctxt.remove_mark(), + }; + } + } + + /// Entry point to crate resolution. + pub fn resolve_crate(&mut self, krate: &Crate) { + self.tcx.sess.time("resolve_crate", || { + self.tcx.sess.time("finalize_imports", || self.finalize_imports()); + let exported_ambiguities = self.tcx.sess.time("compute_effective_visibilities", || { + EffectiveVisibilitiesVisitor::compute_effective_visibilities(self, krate) + }); + self.tcx.sess.time("check_hidden_glob_reexports", || { + self.check_hidden_glob_reexports(exported_ambiguities) + }); + self.tcx + .sess + .time("finalize_macro_resolutions", || self.finalize_macro_resolutions(krate)); + self.tcx.sess.time("late_resolve_crate", || self.late_resolve_crate(krate)); + self.tcx.sess.time("resolve_main", || self.resolve_main()); + self.tcx.sess.time("resolve_check_unused", || self.check_unused(krate)); + self.tcx.sess.time("resolve_report_errors", || self.report_errors(krate)); + self.tcx + .sess + .time("resolve_postprocess", || self.crate_loader(|c| c.postprocess(krate))); + }); + + // Make sure we don't mutate the cstore from here on. + self.tcx.untracked().cstore.freeze(); + } + + fn traits_in_scope( + &mut self, + current_trait: Option<Module<'a>>, + parent_scope: &ParentScope<'a>, + ctxt: SyntaxContext, + assoc_item: Option<(Symbol, Namespace)>, + ) -> Vec<TraitCandidate> { + let mut found_traits = Vec::new(); + + if let Some(module) = current_trait { + if self.trait_may_have_item(Some(module), assoc_item) { + let def_id = module.def_id(); + found_traits.push(TraitCandidate { def_id, import_ids: smallvec![] }); + } + } + + self.visit_scopes(ScopeSet::All(TypeNS), parent_scope, ctxt, |this, scope, _, _| { + match scope { + Scope::Module(module, _) => { + this.traits_in_module(module, assoc_item, &mut found_traits); + } + Scope::StdLibPrelude => { + if let Some(module) = this.prelude { + this.traits_in_module(module, assoc_item, &mut found_traits); + } + } + Scope::ExternPrelude | Scope::ToolPrelude | Scope::BuiltinTypes => {} + _ => unreachable!(), + } + None::<()> + }); + + found_traits + } + + fn traits_in_module( + &mut self, + module: Module<'a>, + assoc_item: Option<(Symbol, Namespace)>, + found_traits: &mut Vec<TraitCandidate>, + ) { + module.ensure_traits(self); + let traits = module.traits.borrow(); + for (trait_name, trait_binding) in traits.as_ref().unwrap().iter() { + if self.trait_may_have_item(trait_binding.module(), assoc_item) { + let def_id = trait_binding.res().def_id(); + let import_ids = self.find_transitive_imports(&trait_binding.kind, *trait_name); + found_traits.push(TraitCandidate { def_id, import_ids }); + } + } + } + + // List of traits in scope is pruned on best effort basis. We reject traits not having an + // associated item with the given name and namespace (if specified). This is a conservative + // optimization, proper hygienic type-based resolution of associated items is done in typeck. + // We don't reject trait aliases (`trait_module == None`) because we don't have access to their + // associated items. + fn trait_may_have_item( + &mut self, + trait_module: Option<Module<'a>>, + assoc_item: Option<(Symbol, Namespace)>, + ) -> bool { + match (trait_module, assoc_item) { + (Some(trait_module), Some((name, ns))) => { + self.resolutions(trait_module).borrow().iter().any(|resolution| { + let (&BindingKey { ident: assoc_ident, ns: assoc_ns, .. }, _) = resolution; + assoc_ns == ns && assoc_ident.name == name + }) + } + _ => true, + } + } + + fn find_transitive_imports( + &mut self, + mut kind: &NameBindingKind<'_>, + trait_name: Ident, + ) -> SmallVec<[LocalDefId; 1]> { + let mut import_ids = smallvec![]; + while let NameBindingKind::Import { import, binding, .. } = kind { + if let Some(node_id) = import.id() { + let def_id = self.local_def_id(node_id); + self.maybe_unused_trait_imports.insert(def_id); + import_ids.push(def_id); + } + self.add_to_glob_map(*import, trait_name); + kind = &binding.kind; + } + import_ids + } + + fn new_disambiguated_key(&mut self, ident: Ident, ns: Namespace) -> BindingKey { + let ident = ident.normalize_to_macros_2_0(); + let disambiguator = if ident.name == kw::Underscore { + self.underscore_disambiguator += 1; + self.underscore_disambiguator + } else { + 0 + }; + BindingKey { ident, ns, disambiguator } + } + + fn resolutions(&mut self, module: Module<'a>) -> &'a Resolutions<'a> { + if module.populate_on_access.get() { + module.populate_on_access.set(false); + self.build_reduced_graph_external(module); + } + &module.0.0.lazy_resolutions + } + + fn resolution( + &mut self, + module: Module<'a>, + key: BindingKey, + ) -> &'a RefCell<NameResolution<'a>> { + *self + .resolutions(module) + .borrow_mut() + .entry(key) + .or_insert_with(|| self.arenas.alloc_name_resolution()) + } + + /// Test if AmbiguityError ambi is any identical to any one inside ambiguity_errors + fn matches_previous_ambiguity_error(&mut self, ambi: &AmbiguityError<'_>) -> bool { + for ambiguity_error in &self.ambiguity_errors { + // if the span location and ident as well as its span are the same + if ambiguity_error.kind == ambi.kind + && ambiguity_error.ident == ambi.ident + && ambiguity_error.ident.span == ambi.ident.span + && ambiguity_error.b1.span == ambi.b1.span + && ambiguity_error.b2.span == ambi.b2.span + && ambiguity_error.misc1 == ambi.misc1 + && ambiguity_error.misc2 == ambi.misc2 + { + return true; + } + } + false + } + + fn record_use(&mut self, ident: Ident, used_binding: NameBinding<'a>, is_lexical_scope: bool) { + self.record_use_inner(ident, used_binding, is_lexical_scope, used_binding.warn_ambiguity); + } + + fn record_use_inner( + &mut self, + ident: Ident, + used_binding: NameBinding<'a>, + is_lexical_scope: bool, + warn_ambiguity: bool, + ) { + if let Some((b2, kind)) = used_binding.ambiguity { + let ambiguity_error = AmbiguityError { + kind, + ident, + b1: used_binding, + b2, + misc1: AmbiguityErrorMisc::None, + misc2: AmbiguityErrorMisc::None, + warning: warn_ambiguity, + }; + if !self.matches_previous_ambiguity_error(&ambiguity_error) { + // avoid duplicated span information to be emit out + self.ambiguity_errors.push(ambiguity_error); + } + } + if let NameBindingKind::Import { import, binding, ref used } = used_binding.kind { + // Avoid marking `extern crate` items that refer to a name from extern prelude, + // but not introduce it, as used if they are accessed from lexical scope. + if is_lexical_scope { + if let Some(entry) = self.extern_prelude.get(&ident.normalize_to_macros_2_0()) { + if !entry.introduced_by_item && entry.binding == Some(used_binding) { + return; + } + } + } + used.set(true); + import.used.set(true); + if let Some(id) = import.id() { + self.used_imports.insert(id); + } + self.add_to_glob_map(import, ident); + self.record_use_inner(ident, binding, false, warn_ambiguity || binding.warn_ambiguity); + } + } + + #[inline] + fn add_to_glob_map(&mut self, import: Import<'_>, ident: Ident) { + if let ImportKind::Glob { id, .. } = import.kind { + let def_id = self.local_def_id(id); + self.glob_map.entry(def_id).or_default().insert(ident.name); + } + } + + fn resolve_crate_root(&mut self, ident: Ident) -> Module<'a> { + debug!("resolve_crate_root({:?})", ident); + let mut ctxt = ident.span.ctxt(); + let mark = if ident.name == kw::DollarCrate { + // When resolving `$crate` from a `macro_rules!` invoked in a `macro`, + // we don't want to pretend that the `macro_rules!` definition is in the `macro` + // as described in `SyntaxContext::apply_mark`, so we ignore prepended opaque marks. + // FIXME: This is only a guess and it doesn't work correctly for `macro_rules!` + // definitions actually produced by `macro` and `macro` definitions produced by + // `macro_rules!`, but at least such configurations are not stable yet. + ctxt = ctxt.normalize_to_macro_rules(); + debug!( + "resolve_crate_root: marks={:?}", + ctxt.marks().into_iter().map(|(i, t)| (i.expn_data(), t)).collect::<Vec<_>>() + ); + let mut iter = ctxt.marks().into_iter().rev().peekable(); + let mut result = None; + // Find the last opaque mark from the end if it exists. + while let Some(&(mark, transparency)) = iter.peek() { + if transparency == Transparency::Opaque { + result = Some(mark); + iter.next(); + } else { + break; + } + } + debug!( + "resolve_crate_root: found opaque mark {:?} {:?}", + result, + result.map(|r| r.expn_data()) + ); + // Then find the last semi-transparent mark from the end if it exists. + for (mark, transparency) in iter { + if transparency == Transparency::SemiTransparent { + result = Some(mark); + } else { + break; + } + } + debug!( + "resolve_crate_root: found semi-transparent mark {:?} {:?}", + result, + result.map(|r| r.expn_data()) + ); + result + } else { + debug!("resolve_crate_root: not DollarCrate"); + ctxt = ctxt.normalize_to_macros_2_0(); + ctxt.adjust(ExpnId::root()) + }; + let module = match mark { + Some(def) => self.expn_def_scope(def), + None => { + debug!( + "resolve_crate_root({:?}): found no mark (ident.span = {:?})", + ident, ident.span + ); + return self.graph_root; + } + }; + let module = self.expect_module( + module.opt_def_id().map_or(LOCAL_CRATE, |def_id| def_id.krate).as_def_id(), + ); + debug!( + "resolve_crate_root({:?}): got module {:?} ({:?}) (ident.span = {:?})", + ident, + module, + module.kind.name(), + ident.span + ); + module + } + + fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> { + let mut module = self.expect_module(module.nearest_parent_mod()); + while module.span.ctxt().normalize_to_macros_2_0() != *ctxt { + let parent = module.parent.unwrap_or_else(|| self.expn_def_scope(ctxt.remove_mark())); + module = self.expect_module(parent.nearest_parent_mod()); + } + module + } + + fn record_partial_res(&mut self, node_id: NodeId, resolution: PartialRes) { + debug!("(recording res) recording {:?} for {}", resolution, node_id); + if let Some(prev_res) = self.partial_res_map.insert(node_id, resolution) { + panic!("path resolved multiple times ({prev_res:?} before, {resolution:?} now)"); + } + } + + fn record_pat_span(&mut self, node: NodeId, span: Span) { + debug!("(recording pat) recording {:?} for {:?}", node, span); + self.pat_span_map.insert(node, span); + } + + fn is_accessible_from( + &self, + vis: ty::Visibility<impl Into<DefId>>, + module: Module<'a>, + ) -> bool { + vis.is_accessible_from(module.nearest_parent_mod(), self.tcx) + } + + fn set_binding_parent_module(&mut self, binding: NameBinding<'a>, module: Module<'a>) { + if let Some(old_module) = self.binding_parent_modules.insert(binding, module) { + if module != old_module { + span_bug!(binding.span, "parent module is reset for binding"); + } + } + } + + fn disambiguate_macro_rules_vs_modularized( + &self, + macro_rules: NameBinding<'a>, + modularized: NameBinding<'a>, + ) -> bool { + // Some non-controversial subset of ambiguities "modularized macro name" vs "macro_rules" + // is disambiguated to mitigate regressions from macro modularization. + // Scoping for `macro_rules` behaves like scoping for `let` at module level, in general. + match ( + self.binding_parent_modules.get(¯o_rules), + self.binding_parent_modules.get(&modularized), + ) { + (Some(macro_rules), Some(modularized)) => { + macro_rules.nearest_parent_mod() == modularized.nearest_parent_mod() + && modularized.is_ancestor_of(*macro_rules) + } + _ => false, + } + } + + fn extern_prelude_get(&mut self, ident: Ident, finalize: bool) -> Option<NameBinding<'a>> { + if ident.is_path_segment_keyword() { + // Make sure `self`, `super` etc produce an error when passed to here. + return None; + } + + let norm_ident = ident.normalize_to_macros_2_0(); + let binding = self.extern_prelude.get(&norm_ident).cloned().and_then(|entry| { + Some(if let Some(binding) = entry.binding { + if finalize { + if !entry.is_import() { + self.crate_loader(|c| c.process_path_extern(ident.name, ident.span)); + } else if entry.introduced_by_item { + self.record_use(ident, binding, false); + } + } + binding + } else { + let crate_id = if finalize { + let Some(crate_id) = + self.crate_loader(|c| c.process_path_extern(ident.name, ident.span)) + else { + return Some(self.dummy_binding); + }; + crate_id + } else { + self.crate_loader(|c| c.maybe_process_path_extern(ident.name))? + }; + let crate_root = self.expect_module(crate_id.as_def_id()); + let vis = ty::Visibility::<DefId>::Public; + (crate_root, vis, DUMMY_SP, LocalExpnId::ROOT).to_name_binding(self.arenas) + }) + }); + + if let Some(entry) = self.extern_prelude.get_mut(&norm_ident) { + entry.binding = binding; + } + + binding + } + + /// Rustdoc uses this to resolve doc link paths in a recoverable way. `PathResult<'a>` + /// isn't something that can be returned because it can't be made to live that long, + /// and also it's a private type. Fortunately rustdoc doesn't need to know the error, + /// just that an error occurred. + fn resolve_rustdoc_path( + &mut self, + path_str: &str, + ns: Namespace, + parent_scope: ParentScope<'a>, + ) -> Option<Res> { + let mut segments = + Vec::from_iter(path_str.split("::").map(Ident::from_str).map(Segment::from_ident)); + if let Some(segment) = segments.first_mut() { + if segment.ident.name == kw::Empty { + segment.ident.name = kw::PathRoot; + } + } + + match self.maybe_resolve_path(&segments, Some(ns), &parent_scope) { + PathResult::Module(ModuleOrUniformRoot::Module(module)) => Some(module.res().unwrap()), + PathResult::NonModule(path_res) => path_res.full_res(), + PathResult::Module(ModuleOrUniformRoot::ExternPrelude) | PathResult::Failed { .. } => { + None + } + PathResult::Module(..) | PathResult::Indeterminate => unreachable!(), + } + } + + /// Retrieves definition span of the given `DefId`. + fn def_span(&self, def_id: DefId) -> Span { + match def_id.as_local() { + Some(def_id) => self.tcx.source_span(def_id), + // Query `def_span` is not used because hashing its result span is expensive. + None => self.cstore().def_span_untracked(def_id, self.tcx.sess), + } + } + + fn field_def_ids(&self, def_id: DefId) -> Option<&'tcx [DefId]> { + match def_id.as_local() { + Some(def_id) => self.field_def_ids.get(&def_id).copied(), + None => Some(self.tcx.associated_item_def_ids(def_id)), + } + } + + /// Checks if an expression refers to a function marked with + /// `#[rustc_legacy_const_generics]` and returns the argument index list + /// from the attribute. + fn legacy_const_generic_args(&mut self, expr: &Expr) -> Option<Vec<usize>> { + if let ExprKind::Path(None, path) = &expr.kind { + // Don't perform legacy const generics rewriting if the path already + // has generic arguments. + if path.segments.last().unwrap().args.is_some() { + return None; + } + + let res = self.partial_res_map.get(&expr.id)?.full_res()?; + if let Res::Def(def::DefKind::Fn, def_id) = res { + // We only support cross-crate argument rewriting. Uses + // within the same crate should be updated to use the new + // const generics style. + if def_id.is_local() { + return None; + } + + if let Some(v) = self.legacy_const_generic_args.get(&def_id) { + return v.clone(); + } + + let attr = self.tcx.get_attr(def_id, sym::rustc_legacy_const_generics)?; + let mut ret = Vec::new(); + for meta in attr.meta_item_list()? { + match meta.lit()?.kind { + LitKind::Int(a, _) => ret.push(a as usize), + _ => panic!("invalid arg index"), + } + } + // Cache the lookup to avoid parsing attributes for an item multiple times. + self.legacy_const_generic_args.insert(def_id, Some(ret.clone())); + return Some(ret); + } + } + None + } + + fn resolve_main(&mut self) { + let module = self.graph_root; + let ident = Ident::with_dummy_span(sym::main); + let parent_scope = &ParentScope::module(module, self); + + let Ok(name_binding) = self.maybe_resolve_ident_in_module( + ModuleOrUniformRoot::Module(module), + ident, + ValueNS, + parent_scope, + ) else { + return; + }; + + let res = name_binding.res(); + let is_import = name_binding.is_import(); + let span = name_binding.span; + if let Res::Def(DefKind::Fn, _) = res { + self.record_use(ident, name_binding, false); + } + self.main_def = Some(MainDefinition { res, is_import, span }); + } +} + +fn names_to_string(names: &[Symbol]) -> String { + let mut result = String::new(); + for (i, name) in names.iter().filter(|name| **name != kw::PathRoot).enumerate() { + if i > 0 { + result.push_str("::"); + } + if Ident::with_dummy_span(*name).is_raw_guess() { + result.push_str("r#"); + } + result.push_str(name.as_str()); + } + result +} + +fn path_names_to_string(path: &Path) -> String { + names_to_string(&path.segments.iter().map(|seg| seg.ident.name).collect::<Vec<_>>()) +} + +/// A somewhat inefficient routine to obtain the name of a module. +fn module_to_string(module: Module<'_>) -> Option<String> { + let mut names = Vec::new(); + + fn collect_mod(names: &mut Vec<Symbol>, module: Module<'_>) { + if let ModuleKind::Def(.., name) = module.kind { + if let Some(parent) = module.parent { + names.push(name); + collect_mod(names, parent); + } + } else { + names.push(Symbol::intern("<opaque>")); + collect_mod(names, module.parent.unwrap()); + } + } + collect_mod(&mut names, module); + + if names.is_empty() { + return None; + } + names.reverse(); + Some(names_to_string(&names)) +} + +#[derive(Copy, Clone, Debug)] +struct Finalize { + /// Node ID for linting. + node_id: NodeId, + /// Span of the whole path or some its characteristic fragment. + /// E.g. span of `b` in `foo::{a, b, c}`, or full span for regular paths. + path_span: Span, + /// Span of the path start, suitable for prepending something to it. + /// E.g. span of `foo` in `foo::{a, b, c}`, or full span for regular paths. + root_span: Span, + /// Whether to report privacy errors or silently return "no resolution" for them, + /// similarly to speculative resolution. + report_private: bool, +} + +impl Finalize { + fn new(node_id: NodeId, path_span: Span) -> Finalize { + Finalize::with_root_span(node_id, path_span, path_span) + } + + fn with_root_span(node_id: NodeId, path_span: Span, root_span: Span) -> Finalize { + Finalize { node_id, path_span, root_span, report_private: true } + } +} + +pub fn provide(providers: &mut Providers) { + providers.registered_tools = macros::registered_tools; +} |