| //! 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 names are resolved here as well. |
| //! |
| //! Type-relative name resolution (methods, fields, associated items) happens in `librustc_typeck`. |
| //! Lifetime names are resolved in `librustc/middle/resolve_lifetime.rs`. |
| |
| #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")] |
| |
| #![feature(inner_deref)] |
| #![feature(crate_visibility_modifier)] |
| #![feature(label_break_value)] |
| #![feature(mem_take)] |
| #![feature(nll)] |
| |
| #![recursion_limit="256"] |
| |
| pub use rustc::hir::def::{Namespace, PerNS}; |
| |
| use Determinacy::*; |
| |
| use rustc::hir::map::Definitions; |
| use rustc::hir::{self, PrimTy, Bool, Char, Float, Int, Uint, Str}; |
| use rustc::middle::cstore::CrateStore; |
| use rustc::session::Session; |
| use rustc::lint; |
| use rustc::hir::def::{self, DefKind, PartialRes, CtorKind, CtorOf, NonMacroAttrKind, ExportMap}; |
| use rustc::hir::def::Namespace::*; |
| use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, DefId}; |
| use rustc::hir::{TraitMap, GlobMap}; |
| use rustc::ty; |
| use rustc::util::nodemap::{NodeMap, NodeSet, FxHashMap, FxHashSet, DefIdMap}; |
| use rustc::span_bug; |
| |
| use rustc_metadata::creader::CrateLoader; |
| use rustc_metadata::cstore::CStore; |
| |
| use syntax::ext::hygiene::{ExpnId, Transparency, SyntaxContext}; |
| use syntax::ast::{self, Name, NodeId, Ident, FloatTy, IntTy, UintTy}; |
| use syntax::ext::base::{SyntaxExtension, MacroKind, SpecialDerives}; |
| use syntax::symbol::{Symbol, kw, sym}; |
| |
| use syntax::visit::{self, Visitor}; |
| use syntax::attr; |
| use syntax::ast::{CRATE_NODE_ID, Crate}; |
| use syntax::ast::{ItemKind, Path}; |
| use syntax::{struct_span_err, unwrap_or}; |
| |
| use syntax_pos::{Span, DUMMY_SP}; |
| use errors::{Applicability, DiagnosticBuilder}; |
| |
| use log::debug; |
| |
| use std::cell::{Cell, RefCell}; |
| use std::{cmp, fmt, iter, ptr}; |
| use std::collections::BTreeSet; |
| use rustc_data_structures::ptr_key::PtrKey; |
| use rustc_data_structures::sync::Lrc; |
| |
| use diagnostics::{Suggestion, ImportSuggestion}; |
| use diagnostics::{find_span_of_binding_until_next_binding, extend_span_to_previous_binding}; |
| use late::{PathSource, Rib, RibKind::*}; |
| use resolve_imports::{ImportDirective, ImportDirectiveSubclass, NameResolution, ImportResolver}; |
| use macros::{LegacyBinding, LegacyScope}; |
| |
| type Res = def::Res<NodeId>; |
| |
| pub mod error_codes; |
| mod diagnostics; |
| mod late; |
| mod macros; |
| mod check_unused; |
| mod build_reduced_graph; |
| mod resolve_imports; |
| |
| const KNOWN_TOOLS: &[Name] = &[sym::clippy, sym::rustfmt]; |
| |
| enum Weak { |
| Yes, |
| No, |
| } |
| |
| #[derive(Copy, Clone, PartialEq, Debug)] |
| pub 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)] |
| enum Scope<'a> { |
| DeriveHelpers, |
| MacroRules(LegacyScope<'a>), |
| CrateRoot, |
| Module(Module<'a>), |
| MacroUsePrelude, |
| BuiltinAttrs, |
| LegacyPluginHelpers, |
| 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. |
| enum ScopeSet { |
| /// All scopes with the given namespace. |
| All(Namespace, /*is_import*/ bool), |
| /// 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), |
| } |
| |
| /// 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)] |
| pub struct ParentScope<'a> { |
| module: Module<'a>, |
| expansion: ExpnId, |
| legacy: LegacyScope<'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. |
| pub fn module(module: Module<'a>) -> ParentScope<'a> { |
| ParentScope { |
| module, |
| expansion: ExpnId::root(), |
| legacy: LegacyScope::Empty, |
| derives: &[], |
| } |
| } |
| } |
| |
| #[derive(Eq)] |
| struct BindingError { |
| name: Name, |
| origin: BTreeSet<Span>, |
| target: BTreeSet<Span>, |
| could_be_path: bool |
| } |
| |
| impl PartialOrd for BindingError { |
| fn partial_cmp(&self, other: &BindingError) -> Option<cmp::Ordering> { |
| Some(self.cmp(other)) |
| } |
| } |
| |
| impl PartialEq for BindingError { |
| fn eq(&self, other: &BindingError) -> bool { |
| self.name == other.name |
| } |
| } |
| |
| impl Ord for BindingError { |
| fn cmp(&self, other: &BindingError) -> cmp::Ordering { |
| self.name.cmp(&other.name) |
| } |
| } |
| |
| enum ResolutionError<'a> { |
| /// Error E0401: can't use type or const parameters from outer function. |
| GenericParamsFromOuterFunction(Res), |
| /// Error E0403: the name is already used for a type or const parameter in this generic |
| /// parameter list. |
| NameAlreadyUsedInParameterList(Name, Span), |
| /// Error E0407: method is not a member of trait. |
| MethodNotMemberOfTrait(Name, &'a str), |
| /// Error E0437: type is not a member of trait. |
| TypeNotMemberOfTrait(Name, &'a str), |
| /// Error E0438: const is not a member of trait. |
| ConstNotMemberOfTrait(Name, &'a str), |
| /// Error E0408: variable `{}` is not bound in all patterns. |
| VariableNotBoundInPattern(&'a BindingError), |
| /// Error E0409: variable `{}` is bound in inconsistent ways within the same match arm. |
| VariableBoundWithDifferentMode(Name, Span), |
| /// Error E0415: identifier is bound more than once in this parameter list. |
| IdentifierBoundMoreThanOnceInParameterList(&'a str), |
| /// Error E0416: identifier is bound more than once in the same pattern. |
| IdentifierBoundMoreThanOnceInSamePattern(&'a str), |
| /// Error E0426: use of undeclared label. |
| UndeclaredLabel(&'a str, Option<Name>), |
| /// Error E0429: `self` imports are only allowed within a `{ }` list. |
| SelfImportsOnlyAllowedWithin, |
| /// 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 { label: String, suggestion: Option<Suggestion> }, |
| /// 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, |
| /// Error E0530: `X` bindings cannot shadow `Y`s. |
| BindingShadowsSomethingUnacceptable(&'a str, Name, &'a NameBinding<'a>), |
| /// Error E0128: type parameters with a default cannot use forward-declared identifiers. |
| ForwardDeclaredTyParam, // FIXME(const_generics:defaults) |
| /// Error E0671: const parameter cannot depend on type parameter. |
| ConstParamDependentOnTypeParam, |
| } |
| |
| // 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)] |
| pub struct Segment { |
| ident: Ident, |
| id: Option<NodeId>, |
| } |
| |
| 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, |
| } |
| } |
| |
| fn names_to_string(segments: &[Segment]) -> String { |
| names_to_string(&segments.iter() |
| .map(|seg| seg.ident) |
| .collect::<Vec<_>>()) |
| } |
| } |
| |
| impl<'a> From<&'a ast::PathSegment> for Segment { |
| fn from(seg: &'a ast::PathSegment) -> Segment { |
| Segment { |
| ident: seg.ident, |
| id: Some(seg.id), |
| } |
| } |
| } |
| |
| struct UsePlacementFinder { |
| target_module: NodeId, |
| span: Option<Span>, |
| found_use: bool, |
| } |
| |
| impl UsePlacementFinder { |
| fn check(krate: &Crate, target_module: NodeId) -> (Option<Span>, bool) { |
| let mut finder = UsePlacementFinder { |
| target_module, |
| span: None, |
| found_use: false, |
| }; |
| visit::walk_crate(&mut finder, krate); |
| (finder.span, finder.found_use) |
| } |
| } |
| |
| impl<'tcx> Visitor<'tcx> for UsePlacementFinder { |
| fn visit_mod( |
| &mut self, |
| module: &'tcx ast::Mod, |
| _: Span, |
| _: &[ast::Attribute], |
| node_id: NodeId, |
| ) { |
| if self.span.is_some() { |
| return; |
| } |
| if node_id != self.target_module { |
| visit::walk_mod(self, module); |
| return; |
| } |
| // find a use statement |
| for item in &module.items { |
| match item.node { |
| ItemKind::Use(..) => { |
| // don't suggest placing a use before the prelude |
| // import or other generated ones |
| if !item.span.from_expansion() { |
| self.span = Some(item.span.shrink_to_lo()); |
| self.found_use = true; |
| return; |
| } |
| }, |
| // don't place use before extern crate |
| ItemKind::ExternCrate(_) => {} |
| // but place them before the first other item |
| _ => if self.span.map_or(true, |span| item.span < span ) { |
| if !item.span.from_expansion() { |
| // don't insert between attributes and an item |
| if item.attrs.is_empty() { |
| self.span = Some(item.span.shrink_to_lo()); |
| } else { |
| // find the first attribute on the item |
| for attr in &item.attrs { |
| if self.span.map_or(true, |span| attr.span < span) { |
| self.span = Some(attr.span.shrink_to_lo()); |
| } |
| } |
| } |
| } |
| }, |
| } |
| } |
| } |
| } |
| |
| /// 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(&'a NameBinding<'a>), |
| Res(Res), |
| } |
| |
| impl<'a> LexicalScopeBinding<'a> { |
| fn item(self) -> Option<&'a NameBinding<'a>> { |
| match self { |
| LexicalScopeBinding::Item(binding) => Some(binding), |
| _ => None, |
| } |
| } |
| |
| fn res(self) -> Res { |
| match self { |
| LexicalScopeBinding::Item(binding) => binding.res(), |
| LexicalScopeBinding::Res(res) => res, |
| } |
| } |
| } |
| |
| #[derive(Copy, Clone, 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, |
| } |
| |
| impl ModuleOrUniformRoot<'_> { |
| fn same_def(lhs: Self, rhs: Self) -> bool { |
| match (lhs, rhs) { |
| (ModuleOrUniformRoot::Module(lhs), |
| ModuleOrUniformRoot::Module(rhs)) => lhs.def_id() == rhs.def_id(), |
| (ModuleOrUniformRoot::CrateRootAndExternPrelude, |
| ModuleOrUniformRoot::CrateRootAndExternPrelude) | |
| (ModuleOrUniformRoot::ExternPrelude, ModuleOrUniformRoot::ExternPrelude) | |
| (ModuleOrUniformRoot::CurrentScope, ModuleOrUniformRoot::CurrentScope) => true, |
| _ => false, |
| } |
| } |
| } |
| |
| #[derive(Clone, Debug)] |
| enum PathResult<'a> { |
| Module(ModuleOrUniformRoot<'a>), |
| NonModule(PartialRes), |
| Indeterminate, |
| Failed { |
| span: Span, |
| label: String, |
| suggestion: Option<Suggestion>, |
| is_error_from_last_segment: bool, |
| }, |
| } |
| |
| 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(NodeId), |
| /// Any module with a name. |
| /// |
| /// This could be: |
| /// |
| /// * A normal module ‒ either `mod from_file;` or `mod from_block { }`. |
| /// * A trait or an enum (it implicitly contains associated types, methods and variant |
| /// constructors). |
| Def(DefKind, DefId, Name), |
| } |
| |
| impl ModuleKind { |
| /// Get name of the module. |
| pub fn name(&self) -> Option<Name> { |
| match self { |
| ModuleKind::Block(..) => None, |
| ModuleKind::Def(.., name) => Some(*name), |
| } |
| } |
| } |
| |
| type Resolutions<'a> = RefCell<FxHashMap<(Ident, Namespace), &'a RefCell<NameResolution<'a>>>>; |
| |
| /// One node in the tree of modules. |
| pub struct ModuleData<'a> { |
| parent: Option<Module<'a>>, |
| kind: ModuleKind, |
| |
| // The def id of the closest normal module (`mod`) ancestor (including this module). |
| normal_ancestor_id: DefId, |
| |
| // 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<ExpnId>>, |
| |
| no_implicit_prelude: bool, |
| |
| glob_importers: RefCell<Vec<&'a ImportDirective<'a>>>, |
| globs: RefCell<Vec<&'a ImportDirective<'a>>>, |
| |
| // Used to memoize the traits in this module for faster searches through all traits in scope. |
| traits: RefCell<Option<Box<[(Ident, &'a NameBinding<'a>)]>>>, |
| |
| /// Span of the module itself. Used for error reporting. |
| span: Span, |
| |
| expansion: ExpnId, |
| } |
| |
| type Module<'a> = &'a ModuleData<'a>; |
| |
| impl<'a> ModuleData<'a> { |
| fn new(parent: Option<Module<'a>>, |
| kind: ModuleKind, |
| normal_ancestor_id: DefId, |
| expansion: ExpnId, |
| span: Span) -> Self { |
| ModuleData { |
| parent, |
| kind, |
| normal_ancestor_id, |
| lazy_resolutions: Default::default(), |
| populate_on_access: Cell::new(!normal_ancestor_id.is_local()), |
| unexpanded_invocations: Default::default(), |
| no_implicit_prelude: false, |
| glob_importers: RefCell::new(Vec::new()), |
| globs: RefCell::new(Vec::new()), |
| traits: RefCell::new(None), |
| span, |
| expansion, |
| } |
| } |
| |
| fn for_each_child<R, F>(&'a self, resolver: &mut R, mut f: F) |
| where R: AsMut<Resolver<'a>>, F: FnMut(&mut R, Ident, Namespace, &'a NameBinding<'a>) |
| { |
| for (&(ident, ns), name_resolution) in resolver.as_mut().resolutions(self).borrow().iter() { |
| name_resolution.borrow().binding.map(|binding| f(resolver, ident, ns, binding)); |
| } |
| } |
| |
| fn for_each_child_stable<R, F>(&'a self, resolver: &mut R, mut f: F) |
| where R: AsMut<Resolver<'a>>, F: FnMut(&mut R, Ident, Namespace, &'a NameBinding<'a>) |
| { |
| let resolutions = resolver.as_mut().resolutions(self).borrow(); |
| let mut resolutions = resolutions.iter().collect::<Vec<_>>(); |
| resolutions.sort_by_cached_key(|&(&(ident, ns), _)| (ident.as_str(), ns)); |
| for &(&(ident, ns), &resolution) in resolutions.iter() { |
| resolution.borrow().binding.map(|binding| f(resolver, ident, ns, binding)); |
| } |
| } |
| |
| fn res(&self) -> Option<Res> { |
| match self.kind { |
| ModuleKind::Def(kind, def_id, _) => Some(Res::Def(kind, def_id)), |
| _ => None, |
| } |
| } |
| |
| fn 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 { |
| match self.kind { |
| ModuleKind::Def(DefKind::Mod, _, _) => true, |
| _ => false, |
| } |
| } |
| |
| fn is_trait(&self) -> bool { |
| match self.kind { |
| ModuleKind::Def(DefKind::Trait, _, _) => true, |
| _ => false, |
| } |
| } |
| |
| fn nearest_item_scope(&'a self) -> Module<'a> { |
| match self.kind { |
| ModuleKind::Def(DefKind::Enum, ..) | ModuleKind::Def(DefKind::Trait, ..) => |
| self.parent.expect("enum or trait module without a parent"), |
| _ => self, |
| } |
| } |
| |
| fn is_ancestor_of(&self, mut other: &Self) -> bool { |
| while !ptr::eq(self, other) { |
| if let Some(parent) = other.parent { |
| other = parent; |
| } else { |
| return false; |
| } |
| } |
| true |
| } |
| } |
| |
| impl<'a> fmt::Debug for ModuleData<'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)] |
| pub struct NameBinding<'a> { |
| kind: NameBindingKind<'a>, |
| ambiguity: Option<(&'a NameBinding<'a>, AmbiguityKind)>, |
| expansion: ExpnId, |
| span: Span, |
| vis: ty::Visibility, |
| } |
| |
| pub trait ToNameBinding<'a> { |
| fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a>; |
| } |
| |
| impl<'a> ToNameBinding<'a> for &'a NameBinding<'a> { |
| fn to_name_binding(self, _: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> { |
| self |
| } |
| } |
| |
| #[derive(Clone, Debug)] |
| enum NameBindingKind<'a> { |
| Res(Res, /* is_macro_export */ bool), |
| Module(Module<'a>), |
| Import { |
| binding: &'a NameBinding<'a>, |
| directive: &'a ImportDirective<'a>, |
| used: Cell<bool>, |
| }, |
| } |
| |
| impl<'a> NameBindingKind<'a> { |
| /// Is this a name binding of a import? |
| fn is_import(&self) -> bool { |
| match *self { |
| NameBindingKind::Import { .. } => true, |
| _ => false, |
| } |
| } |
| } |
| |
| struct PrivacyError<'a>(Span, Ident, &'a NameBinding<'a>); |
| |
| struct UseError<'a> { |
| err: DiagnosticBuilder<'a>, |
| /// Attach `use` statements for these candidates. |
| candidates: Vec<ImportSuggestion>, |
| /// The `NodeId` of the module to place the use-statements in. |
| node_id: NodeId, |
| /// Whether the diagnostic should state that it's "better". |
| better: bool, |
| } |
| |
| #[derive(Clone, Copy, PartialEq, Debug)] |
| enum AmbiguityKind { |
| Import, |
| BuiltinAttr, |
| DeriveHelper, |
| LegacyHelperVsPrelude, |
| LegacyVsModern, |
| GlobVsOuter, |
| GlobVsGlob, |
| GlobVsExpanded, |
| MoreExpandedVsOuter, |
| } |
| |
| impl AmbiguityKind { |
| fn descr(self) -> &'static str { |
| match self { |
| AmbiguityKind::Import => |
| "name vs any other name during import resolution", |
| AmbiguityKind::BuiltinAttr => |
| "built-in attribute vs any other name", |
| AmbiguityKind::DeriveHelper => |
| "derive helper attribute vs any other name", |
| AmbiguityKind::LegacyHelperVsPrelude => |
| "legacy plugin helper attribute vs name from prelude", |
| AmbiguityKind::LegacyVsModern => |
| "`macro_rules` vs non-`macro_rules` from other module", |
| AmbiguityKind::GlobVsOuter => |
| "glob import vs any other name from outer scope during import/macro resolution", |
| AmbiguityKind::GlobVsGlob => |
| "glob import vs glob import in the same module", |
| AmbiguityKind::GlobVsExpanded => |
| "glob import vs macro-expanded name in the same \ |
| module during import/macro resolution", |
| AmbiguityKind::MoreExpandedVsOuter => |
| "macro-expanded name vs less macro-expanded name \ |
| from outer scope during import/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: &'a NameBinding<'a>, |
| b2: &'a NameBinding<'a>, |
| misc1: AmbiguityErrorMisc, |
| misc2: AmbiguityErrorMisc, |
| } |
| |
| impl<'a> NameBinding<'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, |
| } |
| } |
| |
| // We sometimes need to treat variants as `pub` for backwards compatibility. |
| fn pseudo_vis(&self) -> ty::Visibility { |
| if self.is_variant() && self.res().def_id().is_local() { |
| ty::Visibility::Public |
| } else { |
| self.vis |
| } |
| } |
| |
| fn is_variant(&self) -> bool { |
| match self.kind { |
| NameBindingKind::Res(Res::Def(DefKind::Variant, _), _) | |
| NameBindingKind::Res(Res::Def(DefKind::Ctor(CtorOf::Variant, ..), _), _) => true, |
| _ => false, |
| } |
| } |
| |
| fn is_extern_crate(&self) -> bool { |
| match self.kind { |
| NameBindingKind::Import { |
| directive: &ImportDirective { |
| subclass: ImportDirectiveSubclass::ExternCrate { .. }, .. |
| }, .. |
| } => true, |
| NameBindingKind::Module( |
| &ModuleData { kind: ModuleKind::Def(DefKind::Mod, def_id, _), .. } |
| ) => def_id.index == CRATE_DEF_INDEX, |
| _ => false, |
| } |
| } |
| |
| fn is_import(&self) -> bool { |
| match self.kind { |
| NameBindingKind::Import { .. } => true, |
| _ => false, |
| } |
| } |
| |
| fn is_glob_import(&self) -> bool { |
| match self.kind { |
| NameBindingKind::Import { directive, .. } => directive.is_glob(), |
| _ => false, |
| } |
| } |
| |
| fn is_importable(&self) -> bool { |
| match self.res() { |
| Res::Def(DefKind::AssocConst, _) |
| | Res::Def(DefKind::Method, _) |
| | Res::Def(DefKind::AssocTy, _) => false, |
| _ => true, |
| } |
| } |
| |
| fn is_macro_def(&self) -> bool { |
| match self.kind { |
| NameBindingKind::Res(Res::Def(DefKind::Macro(..), _), _) => true, |
| _ => false, |
| } |
| } |
| |
| 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: ExpnId, 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) |
| } |
| } |
| |
| /// Interns the names of the primitive types. |
| /// |
| /// All other types are defined somewhere and possibly imported, but the primitive ones need |
| /// special handling, since they have no place of origin. |
| struct PrimitiveTypeTable { |
| primitive_types: FxHashMap<Name, PrimTy>, |
| } |
| |
| impl PrimitiveTypeTable { |
| fn new() -> PrimitiveTypeTable { |
| let mut table = FxHashMap::default(); |
| |
| table.insert(sym::bool, Bool); |
| table.insert(sym::char, Char); |
| table.insert(sym::f32, Float(FloatTy::F32)); |
| table.insert(sym::f64, Float(FloatTy::F64)); |
| table.insert(sym::isize, Int(IntTy::Isize)); |
| table.insert(sym::i8, Int(IntTy::I8)); |
| table.insert(sym::i16, Int(IntTy::I16)); |
| table.insert(sym::i32, Int(IntTy::I32)); |
| table.insert(sym::i64, Int(IntTy::I64)); |
| table.insert(sym::i128, Int(IntTy::I128)); |
| table.insert(sym::str, Str); |
| table.insert(sym::usize, Uint(UintTy::Usize)); |
| table.insert(sym::u8, Uint(UintTy::U8)); |
| table.insert(sym::u16, Uint(UintTy::U16)); |
| table.insert(sym::u32, Uint(UintTy::U32)); |
| table.insert(sym::u64, Uint(UintTy::U64)); |
| table.insert(sym::u128, Uint(UintTy::U128)); |
| Self { primitive_types: table } |
| } |
| } |
| |
| #[derive(Debug, Default, Clone)] |
| pub struct ExternPreludeEntry<'a> { |
| extern_crate_item: Option<&'a NameBinding<'a>>, |
| pub introduced_by_item: bool, |
| } |
| |
| /// The main resolver class. |
| /// |
| /// This is the visitor that walks the whole crate. |
| pub struct Resolver<'a> { |
| session: &'a Session, |
| cstore: &'a CStore, |
| |
| pub definitions: Definitions, |
| |
| pub graph_root: Module<'a>, |
| |
| prelude: Option<Module<'a>>, |
| pub extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'a>>, |
| |
| /// N.B., this is used only for better diagnostics, not name resolution itself. |
| has_self: FxHashSet<DefId>, |
| |
| /// Names of fields of an item `DefId` accessible with dot syntax. |
| /// Used for hints during error reporting. |
| field_names: FxHashMap<DefId, Vec<Name>>, |
| |
| /// All imports known to succeed or fail. |
| determined_imports: Vec<&'a ImportDirective<'a>>, |
| |
| /// All non-determined imports. |
| indeterminate_imports: Vec<&'a ImportDirective<'a>>, |
| |
| /// FIXME: Refactor things so that these fields are passed through arguments and not resolver. |
| /// We are resolving a last import segment during import validation. |
| last_import_segment: bool, |
| /// This binding should be ignored during in-module resolution, so that we don't get |
| /// "self-confirming" import resolutions during import validation. |
| blacklisted_binding: Option<&'a NameBinding<'a>>, |
| |
| /// The idents for the primitive types. |
| primitive_type_table: PrimitiveTypeTable, |
| |
| /// 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>, |
| |
| pub export_map: ExportMap<NodeId>, |
| pub trait_map: TraitMap, |
| |
| /// 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>>, |
| extern_module_map: FxHashMap<(DefId, bool /* MacrosOnly? */), Module<'a>>, |
| binding_parent_modules: FxHashMap<PtrKey<'a, NameBinding<'a>>, Module<'a>>, |
| |
| /// Maps glob imports to the names of items actually imported. |
| pub glob_map: GlobMap, |
| |
| used_imports: FxHashSet<(NodeId, Namespace)>, |
| pub maybe_unused_trait_imports: NodeSet, |
| pub maybe_unused_extern_crates: Vec<(NodeId, Span)>, |
| |
| /// 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<'a>>, |
| /// 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: &'a NameBinding<'a>, |
| |
| crate_loader: &'a mut CrateLoader<'a>, |
| macro_names: FxHashSet<Ident>, |
| builtin_macros: FxHashMap<Name, SyntaxExtension>, |
| macro_use_prelude: FxHashMap<Name, &'a NameBinding<'a>>, |
| pub all_macros: FxHashMap<Name, Res>, |
| macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>, |
| dummy_ext_bang: Lrc<SyntaxExtension>, |
| dummy_ext_derive: Lrc<SyntaxExtension>, |
| non_macro_attrs: [Lrc<SyntaxExtension>; 2], |
| macro_defs: FxHashMap<ExpnId, DefId>, |
| local_macro_def_scopes: FxHashMap<NodeId, Module<'a>>, |
| ast_transform_scopes: FxHashMap<ExpnId, Module<'a>>, |
| unused_macros: NodeMap<Span>, |
| proc_macro_stubs: NodeSet, |
| /// Traces collected during macro resolution and validated when it's complete. |
| single_segment_macro_resolutions: Vec<(Ident, MacroKind, ParentScope<'a>, |
| Option<&'a NameBinding<'a>>)>, |
| multi_segment_macro_resolutions: Vec<(Vec<Segment>, Span, MacroKind, ParentScope<'a>, |
| Option<Res>)>, |
| builtin_attrs: Vec<(Ident, ParentScope<'a>)>, |
| /// Some built-in derives mark 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. |
| /// FIXME: Find a way for `PartialEq` and `Eq` to emulate `#[structural_match]` |
| /// by marking the produced impls rather than the original items. |
| special_derives: FxHashMap<ExpnId, SpecialDerives>, |
| /// 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<ExpnId, ParentScope<'a>>, |
| /// Legacy scopes *produced* by expanding the macro invocations, |
| /// include all the `macro_rules` items and other invocations generated by them. |
| output_legacy_scopes: FxHashMap<ExpnId, LegacyScope<'a>>, |
| |
| /// Avoid duplicated errors for "name already defined". |
| name_already_seen: FxHashMap<Name, Span>, |
| |
| potentially_unused_imports: Vec<&'a ImportDirective<'a>>, |
| |
| /// Table for mapping struct IDs into struct constructor IDs, |
| /// it's not used during normal resolution, only for better error reporting. |
| struct_constructors: DefIdMap<(Res, ty::Visibility)>, |
| |
| /// Features enabled for this crate. |
| active_features: FxHashSet<Symbol>, |
| |
| /// Stores enum visibilities to properly build a reduced graph |
| /// when visiting the correspondent variants. |
| variant_vis: DefIdMap<ty::Visibility>, |
| } |
| |
| /// Nothing really interesting here; it just provides memory for the rest of the crate. |
| #[derive(Default)] |
| pub struct ResolverArenas<'a> { |
| modules: arena::TypedArena<ModuleData<'a>>, |
| local_modules: RefCell<Vec<Module<'a>>>, |
| name_bindings: arena::TypedArena<NameBinding<'a>>, |
| import_directives: arena::TypedArena<ImportDirective<'a>>, |
| name_resolutions: arena::TypedArena<RefCell<NameResolution<'a>>>, |
| legacy_bindings: arena::TypedArena<LegacyBinding<'a>>, |
| ast_paths: arena::TypedArena<ast::Path>, |
| } |
| |
| impl<'a> ResolverArenas<'a> { |
| fn alloc_module(&'a self, module: ModuleData<'a>) -> Module<'a> { |
| let module = self.modules.alloc(module); |
| if module.def_id().map(|def_id| def_id.is_local()).unwrap_or(true) { |
| self.local_modules.borrow_mut().push(module); |
| } |
| 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: NameBinding<'a>) -> &'a NameBinding<'a> { |
| self.name_bindings.alloc(name_binding) |
| } |
| fn alloc_import_directive(&'a self, import_directive: ImportDirective<'a>) |
| -> &'a ImportDirective<'_> { |
| self.import_directives.alloc(import_directive) |
| } |
| fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> { |
| self.name_resolutions.alloc(Default::default()) |
| } |
| fn alloc_legacy_binding(&'a self, binding: LegacyBinding<'a>) -> &'a LegacyBinding<'a> { |
| self.legacy_bindings.alloc(binding) |
| } |
| fn alloc_ast_paths(&'a self, paths: &[ast::Path]) -> &'a [ast::Path] { |
| self.ast_paths.alloc_from_iter(paths.iter().cloned()) |
| } |
| } |
| |
| impl<'a> AsMut<Resolver<'a>> for Resolver<'a> { |
| fn as_mut(&mut self) -> &mut Resolver<'a> { self } |
| } |
| |
| impl<'a, 'b> ty::DefIdTree for &'a Resolver<'b> { |
| fn parent(self, id: DefId) -> Option<DefId> { |
| match id.krate { |
| LOCAL_CRATE => self.definitions.def_key(id.index).parent, |
| _ => self.cstore.def_key(id).parent, |
| }.map(|index| DefId { index, ..id }) |
| } |
| } |
| |
| /// This interface is used through the AST→HIR step, to embed full paths into the HIR. After that |
| /// the resolver is no longer needed as all the relevant information is inline. |
| impl<'a> hir::lowering::Resolver for Resolver<'a> { |
| fn resolve_str_path( |
| &mut self, |
| span: Span, |
| crate_root: Option<Symbol>, |
| components: &[Symbol], |
| ns: Namespace, |
| ) -> (ast::Path, Res) { |
| let root = if crate_root.is_some() { |
| kw::PathRoot |
| } else { |
| kw::Crate |
| }; |
| let segments = iter::once(Ident::with_dummy_span(root)) |
| .chain( |
| crate_root.into_iter() |
| .chain(components.iter().cloned()) |
| .map(Ident::with_dummy_span) |
| ).map(|i| self.new_ast_path_segment(i)).collect::<Vec<_>>(); |
| |
| let path = ast::Path { |
| span, |
| segments, |
| }; |
| |
| let parent_scope = &ParentScope::module(self.graph_root); |
| let res = match self.resolve_ast_path(&path, ns, parent_scope) { |
| Ok(res) => res, |
| Err((span, error)) => { |
| self.report_error(span, error); |
| Res::Err |
| } |
| }; |
| (path, res) |
| } |
| |
| fn get_partial_res(&mut self, id: NodeId) -> Option<PartialRes> { |
| self.partial_res_map.get(&id).cloned() |
| } |
| |
| fn get_import_res(&mut self, id: NodeId) -> PerNS<Option<Res>> { |
| self.import_res_map.get(&id).cloned().unwrap_or_default() |
| } |
| |
| fn get_label_res(&mut self, id: NodeId) -> Option<NodeId> { |
| self.label_res_map.get(&id).cloned() |
| } |
| |
| fn definitions(&mut self) -> &mut Definitions { |
| &mut self.definitions |
| } |
| |
| fn has_derives(&self, node_id: NodeId, derives: SpecialDerives) -> bool { |
| let def_id = self.definitions.local_def_id(node_id); |
| let expn_id = self.definitions.expansion_that_defined(def_id.index); |
| self.has_derives(expn_id, derives) |
| } |
| } |
| |
| impl<'a> Resolver<'a> { |
| pub fn new(session: &'a Session, |
| cstore: &'a CStore, |
| krate: &Crate, |
| crate_name: &str, |
| crate_loader: &'a mut CrateLoader<'a>, |
| arenas: &'a ResolverArenas<'a>) |
| -> Resolver<'a> { |
| let root_def_id = DefId::local(CRATE_DEF_INDEX); |
| let root_module_kind = ModuleKind::Def( |
| DefKind::Mod, |
| root_def_id, |
| kw::Invalid, |
| ); |
| let graph_root = arenas.alloc_module(ModuleData { |
| no_implicit_prelude: attr::contains_name(&krate.attrs, sym::no_implicit_prelude), |
| ..ModuleData::new(None, root_module_kind, root_def_id, ExpnId::root(), krate.span) |
| }); |
| let empty_module_kind = ModuleKind::Def( |
| DefKind::Mod, |
| root_def_id, |
| kw::Invalid, |
| ); |
| let empty_module = arenas.alloc_module(ModuleData { |
| no_implicit_prelude: true, |
| ..ModuleData::new( |
| Some(graph_root), |
| empty_module_kind, |
| root_def_id, |
| ExpnId::root(), |
| DUMMY_SP, |
| ) |
| }); |
| let mut module_map = FxHashMap::default(); |
| module_map.insert(DefId::local(CRATE_DEF_INDEX), graph_root); |
| |
| let mut definitions = Definitions::default(); |
| definitions.create_root_def(crate_name, session.local_crate_disambiguator()); |
| |
| let mut extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'_>> = |
| session.opts.externs.iter().map(|kv| (Ident::from_str(kv.0), Default::default())) |
| .collect(); |
| |
| if !attr::contains_name(&krate.attrs, sym::no_core) { |
| extern_prelude.insert(Ident::with_dummy_span(sym::core), Default::default()); |
| if !attr::contains_name(&krate.attrs, sym::no_std) { |
| extern_prelude.insert(Ident::with_dummy_span(sym::std), Default::default()); |
| if session.rust_2018() { |
| extern_prelude.insert(Ident::with_dummy_span(sym::meta), Default::default()); |
| } |
| } |
| } |
| |
| let mut invocation_parent_scopes = FxHashMap::default(); |
| invocation_parent_scopes.insert(ExpnId::root(), ParentScope::module(graph_root)); |
| |
| let mut macro_defs = FxHashMap::default(); |
| macro_defs.insert(ExpnId::root(), root_def_id); |
| |
| let features = session.features_untracked(); |
| let non_macro_attr = |
| |mark_used| Lrc::new(SyntaxExtension::non_macro_attr(mark_used, session.edition())); |
| |
| Resolver { |
| session, |
| |
| cstore, |
| |
| definitions, |
| |
| // The outermost module has def ID 0; this is not reflected in the |
| // AST. |
| graph_root, |
| prelude: None, |
| extern_prelude, |
| |
| has_self: FxHashSet::default(), |
| field_names: FxHashMap::default(), |
| |
| determined_imports: Vec::new(), |
| indeterminate_imports: Vec::new(), |
| |
| last_import_segment: false, |
| blacklisted_binding: None, |
| |
| primitive_type_table: PrimitiveTypeTable::new(), |
| |
| partial_res_map: Default::default(), |
| import_res_map: Default::default(), |
| label_res_map: Default::default(), |
| export_map: FxHashMap::default(), |
| trait_map: Default::default(), |
| empty_module, |
| module_map, |
| block_map: Default::default(), |
| extern_module_map: FxHashMap::default(), |
| binding_parent_modules: FxHashMap::default(), |
| ast_transform_scopes: FxHashMap::default(), |
| |
| glob_map: Default::default(), |
| |
| used_imports: FxHashSet::default(), |
| maybe_unused_trait_imports: Default::default(), |
| maybe_unused_extern_crates: Vec::new(), |
| |
| privacy_errors: Vec::new(), |
| ambiguity_errors: Vec::new(), |
| use_injections: Vec::new(), |
| macro_expanded_macro_export_errors: BTreeSet::new(), |
| |
| arenas, |
| dummy_binding: arenas.alloc_name_binding(NameBinding { |
| kind: NameBindingKind::Res(Res::Err, false), |
| ambiguity: None, |
| expansion: ExpnId::root(), |
| span: DUMMY_SP, |
| vis: ty::Visibility::Public, |
| }), |
| |
| crate_loader, |
| macro_names: FxHashSet::default(), |
| builtin_macros: Default::default(), |
| macro_use_prelude: FxHashMap::default(), |
| all_macros: FxHashMap::default(), |
| macro_map: FxHashMap::default(), |
| dummy_ext_bang: Lrc::new(SyntaxExtension::dummy_bang(session.edition())), |
| dummy_ext_derive: Lrc::new(SyntaxExtension::dummy_derive(session.edition())), |
| non_macro_attrs: [non_macro_attr(false), non_macro_attr(true)], |
| invocation_parent_scopes, |
| output_legacy_scopes: Default::default(), |
| macro_defs, |
| local_macro_def_scopes: FxHashMap::default(), |
| name_already_seen: FxHashMap::default(), |
| potentially_unused_imports: Vec::new(), |
| struct_constructors: Default::default(), |
| unused_macros: Default::default(), |
| proc_macro_stubs: Default::default(), |
| single_segment_macro_resolutions: Default::default(), |
| multi_segment_macro_resolutions: Default::default(), |
| builtin_attrs: Default::default(), |
| special_derives: Default::default(), |
| active_features: |
| features.declared_lib_features.iter().map(|(feat, ..)| *feat) |
| .chain(features.declared_lang_features.iter().map(|(feat, ..)| *feat)) |
| .collect(), |
| variant_vis: Default::default() |
| } |
| } |
| |
| pub fn arenas() -> ResolverArenas<'a> { |
| Default::default() |
| } |
| |
| fn non_macro_attr(&self, mark_used: bool) -> Lrc<SyntaxExtension> { |
| self.non_macro_attrs[mark_used as usize].clone() |
| } |
| |
| 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(true), |
| } |
| } |
| |
| /// 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).map_or(false, |ext| ext.is_builtin) |
| } |
| |
| fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId { |
| loop { |
| match self.macro_defs.get(&ctxt.outer_expn()) { |
| Some(&def_id) => return def_id, |
| None => ctxt.remove_mark(), |
| }; |
| } |
| } |
| |
| fn has_derives(&self, expn_id: ExpnId, markers: SpecialDerives) -> bool { |
| self.special_derives.get(&expn_id).map_or(false, |m| m.contains(markers)) |
| } |
| |
| /// Entry point to crate resolution. |
| pub fn resolve_crate(&mut self, krate: &Crate) { |
| ImportResolver { r: self }.finalize_imports(); |
| self.finalize_macro_resolutions(); |
| |
| self.late_resolve_crate(krate); |
| |
| self.check_unused(krate); |
| self.report_errors(krate); |
| self.crate_loader.postprocess(krate); |
| } |
| |
| fn new_module( |
| &self, |
| parent: Module<'a>, |
| kind: ModuleKind, |
| normal_ancestor_id: DefId, |
| expn_id: ExpnId, |
| span: Span, |
| ) -> Module<'a> { |
| let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expn_id, span); |
| self.arenas.alloc_module(module) |
| } |
| |
| 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.lazy_resolutions |
| } |
| |
| fn resolution(&mut self, module: Module<'a>, ident: Ident, ns: Namespace) |
| -> &'a RefCell<NameResolution<'a>> { |
| *self.resolutions(module).borrow_mut().entry((ident.modern(), ns)) |
| .or_insert_with(|| self.arenas.alloc_name_resolution()) |
| } |
| |
| fn record_use(&mut self, ident: Ident, ns: Namespace, |
| used_binding: &'a NameBinding<'a>, is_lexical_scope: bool) { |
| if let Some((b2, kind)) = used_binding.ambiguity { |
| self.ambiguity_errors.push(AmbiguityError { |
| kind, ident, b1: used_binding, b2, |
| misc1: AmbiguityErrorMisc::None, |
| misc2: AmbiguityErrorMisc::None, |
| }); |
| } |
| if let NameBindingKind::Import { directive, 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.modern()) { |
| if let Some(crate_item) = entry.extern_crate_item { |
| if ptr::eq(used_binding, crate_item) && !entry.introduced_by_item { |
| return; |
| } |
| } |
| } |
| } |
| used.set(true); |
| directive.used.set(true); |
| self.used_imports.insert((directive.id, ns)); |
| self.add_to_glob_map(&directive, ident); |
| self.record_use(ident, ns, binding, false); |
| } |
| } |
| |
| #[inline] |
| fn add_to_glob_map(&mut self, directive: &ImportDirective<'_>, ident: Ident) { |
| if directive.is_glob() { |
| self.glob_map.entry(directive.id).or_default().insert(ident.name); |
| } |
| } |
| |
| /// A generic scope visitor. |
| /// Visits scopes in order to resolve some identifier in them or perform other actions. |
| /// If the callback returns `Some` result, we stop visiting scopes and return it. |
| fn visit_scopes<T>( |
| &mut self, |
| scope_set: ScopeSet, |
| parent_scope: &ParentScope<'a>, |
| ident: Ident, |
| mut visitor: impl FnMut(&mut Self, Scope<'a>, /*use_prelude*/ bool, Ident) -> Option<T>, |
| ) -> Option<T> { |
| // General principles: |
| // 1. Not controlled (user-defined) names should have higher priority than controlled names |
| // built into the language or standard library. This way we can add new names into the |
| // language or standard library without breaking user code. |
| // 2. "Closed set" below means new names cannot appear after the current resolution attempt. |
| // Places to search (in order of decreasing priority): |
| // (Type NS) |
| // 1. FIXME: Ribs (type parameters), there's no necessary infrastructure yet |
| // (open set, not controlled). |
| // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents |
| // (open, not controlled). |
| // 3. Extern prelude (open, the open part is from macro expansions, not controlled). |
| // 4. Tool modules (closed, controlled right now, but not in the future). |
| // 5. Standard library prelude (de-facto closed, controlled). |
| // 6. Language prelude (closed, controlled). |
| // (Value NS) |
| // 1. FIXME: Ribs (local variables), there's no necessary infrastructure yet |
| // (open set, not controlled). |
| // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents |
| // (open, not controlled). |
| // 3. Standard library prelude (de-facto closed, controlled). |
| // (Macro NS) |
| // 1-3. Derive helpers (open, not controlled). All ambiguities with other names |
| // are currently reported as errors. They should be higher in priority than preludes |
| // and probably even names in modules according to the "general principles" above. They |
| // also should be subject to restricted shadowing because are effectively produced by |
| // derives (you need to resolve the derive first to add helpers into scope), but they |
| // should be available before the derive is expanded for compatibility. |
| // It's mess in general, so we are being conservative for now. |
| // 1-3. `macro_rules` (open, not controlled), loop through legacy scopes. Have higher |
| // priority than prelude macros, but create ambiguities with macros in modules. |
| // 1-3. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents |
| // (open, not controlled). Have higher priority than prelude macros, but create |
| // ambiguities with `macro_rules`. |
| // 4. `macro_use` prelude (open, the open part is from macro expansions, not controlled). |
| // 4a. User-defined prelude from macro-use |
| // (open, the open part is from macro expansions, not controlled). |
| // 4b. "Standard library prelude" part implemented through `macro-use` (closed, controlled). |
| // 4c. Standard library prelude (de-facto closed, controlled). |
| // 6. Language prelude: builtin attributes (closed, controlled). |
| // 4-6. Legacy plugin helpers (open, not controlled). Similar to derive helpers, |
| // but introduced by legacy plugins using `register_attribute`. Priority is somewhere |
| // in prelude, not sure where exactly (creates ambiguities with any other prelude names). |
| |
| let rust_2015 = ident.span.rust_2015(); |
| let (ns, is_absolute_path) = match scope_set { |
| ScopeSet::All(ns, _) => (ns, false), |
| ScopeSet::AbsolutePath(ns) => (ns, true), |
| ScopeSet::Macro(_) => (MacroNS, false), |
| }; |
| // Jump out of trait or enum modules, they do not act as scopes. |
| let module = parent_scope.module.nearest_item_scope(); |
| let mut scope = match ns { |
| _ if is_absolute_path => Scope::CrateRoot, |
| TypeNS | ValueNS => Scope::Module(module), |
| MacroNS => Scope::DeriveHelpers, |
| }; |
| let mut ident = ident.modern(); |
| let mut use_prelude = !module.no_implicit_prelude; |
| |
| loop { |
| let visit = match scope { |
| Scope::DeriveHelpers => true, |
| Scope::MacroRules(..) => true, |
| Scope::CrateRoot => true, |
| Scope::Module(..) => true, |
| Scope::MacroUsePrelude => use_prelude || rust_2015, |
| Scope::BuiltinAttrs => true, |
| Scope::LegacyPluginHelpers => use_prelude || rust_2015, |
| Scope::ExternPrelude => use_prelude || is_absolute_path, |
| Scope::ToolPrelude => use_prelude, |
| Scope::StdLibPrelude => use_prelude || ns == MacroNS, |
| Scope::BuiltinTypes => true, |
| }; |
| |
| if visit { |
| if let break_result @ Some(..) = visitor(self, scope, use_prelude, ident) { |
| return break_result; |
| } |
| } |
| |
| scope = match scope { |
| Scope::DeriveHelpers => |
| Scope::MacroRules(parent_scope.legacy), |
| Scope::MacroRules(legacy_scope) => match legacy_scope { |
| LegacyScope::Binding(binding) => Scope::MacroRules( |
| binding.parent_legacy_scope |
| ), |
| LegacyScope::Invocation(invoc_id) => Scope::MacroRules( |
| self.output_legacy_scopes.get(&invoc_id).cloned() |
| .unwrap_or(self.invocation_parent_scopes[&invoc_id].legacy) |
| ), |
| LegacyScope::Empty => Scope::Module(module), |
| } |
| Scope::CrateRoot => match ns { |
| TypeNS => { |
| ident.span.adjust(ExpnId::root()); |
| Scope::ExternPrelude |
| } |
| ValueNS | MacroNS => break, |
| } |
| Scope::Module(module) => { |
| use_prelude = !module.no_implicit_prelude; |
| match self.hygienic_lexical_parent(module, &mut ident.span) { |
| Some(parent_module) => Scope::Module(parent_module), |
| None => { |
| ident.span.adjust(ExpnId::root()); |
| match ns { |
| TypeNS => Scope::ExternPrelude, |
| ValueNS => Scope::StdLibPrelude, |
| MacroNS => Scope::MacroUsePrelude, |
| } |
| } |
| } |
| } |
| Scope::MacroUsePrelude => Scope::StdLibPrelude, |
| Scope::BuiltinAttrs => Scope::LegacyPluginHelpers, |
| Scope::LegacyPluginHelpers => break, // nowhere else to search |
| Scope::ExternPrelude if is_absolute_path => break, |
| Scope::ExternPrelude => Scope::ToolPrelude, |
| Scope::ToolPrelude => Scope::StdLibPrelude, |
| Scope::StdLibPrelude => match ns { |
| TypeNS => Scope::BuiltinTypes, |
| ValueNS => break, // nowhere else to search |
| MacroNS => Scope::BuiltinAttrs, |
| } |
| Scope::BuiltinTypes => break, // nowhere else to search |
| }; |
| } |
| |
| None |
| } |
| |
| /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope. |
| /// More specifically, we proceed up the hierarchy of scopes and return the binding for |
| /// `ident` in the first scope that defines it (or None if no scopes define it). |
| /// |
| /// A block's items are above its local variables in the scope hierarchy, regardless of where |
| /// the items are defined in the block. For example, |
| /// ```rust |
| /// fn f() { |
| /// g(); // Since there are no local variables in scope yet, this resolves to the item. |
| /// let g = || {}; |
| /// fn g() {} |
| /// g(); // This resolves to the local variable `g` since it shadows the item. |
| /// } |
| /// ``` |
| /// |
| /// Invariant: This must only be called during main resolution, not during |
| /// import resolution. |
| fn resolve_ident_in_lexical_scope(&mut self, |
| mut ident: Ident, |
| ns: Namespace, |
| parent_scope: &ParentScope<'a>, |
| record_used_id: Option<NodeId>, |
| path_span: Span, |
| ribs: &[Rib<'a>]) |
| -> Option<LexicalScopeBinding<'a>> { |
| assert!(ns == TypeNS || ns == ValueNS); |
| if ident.name == kw::Invalid { |
| return Some(LexicalScopeBinding::Res(Res::Err)); |
| } |
| let (general_span, modern_span) = if ident.name == kw::SelfUpper { |
| // FIXME(jseyfried) improve `Self` hygiene |
| let empty_span = ident.span.with_ctxt(SyntaxContext::root()); |
| (empty_span, empty_span) |
| } else if ns == TypeNS { |
| let modern_span = ident.span.modern(); |
| (modern_span, modern_span) |
| } else { |
| (ident.span.modern_and_legacy(), ident.span.modern()) |
| }; |
| ident.span = general_span; |
| let modern_ident = Ident { span: modern_span, ..ident }; |
| |
| // Walk backwards up the ribs in scope. |
| let record_used = record_used_id.is_some(); |
| let mut module = self.graph_root; |
| for i in (0 .. ribs.len()).rev() { |
| debug!("walk rib\n{:?}", ribs[i].bindings); |
| // Use the rib kind to determine whether we are resolving parameters |
| // (modern hygiene) or local variables (legacy hygiene). |
| let rib_ident = if ribs[i].kind.contains_params() { |
| modern_ident |
| } else { |
| ident |
| }; |
| if let Some(res) = ribs[i].bindings.get(&rib_ident).cloned() { |
| // The ident resolves to a type parameter or local variable. |
| return Some(LexicalScopeBinding::Res( |
| self.validate_res_from_ribs(i, res, record_used, path_span, ribs), |
| )); |
| } |
| |
| module = match ribs[i].kind { |
| ModuleRibKind(module) => module, |
| MacroDefinition(def) if def == self.macro_def(ident.span.ctxt()) => { |
| // If an invocation of this macro created `ident`, give up on `ident` |
| // and switch to `ident`'s source from the macro definition. |
| ident.span.remove_mark(); |
| continue |
| } |
| _ => continue, |
| }; |
| |
| |
| let item = self.resolve_ident_in_module_unadjusted( |
| ModuleOrUniformRoot::Module(module), |
| ident, |
| ns, |
| parent_scope, |
| record_used, |
| path_span, |
| ); |
| if let Ok(binding) = item { |
| // The ident resolves to an item. |
| return Some(LexicalScopeBinding::Item(binding)); |
| } |
| |
| match module.kind { |
| ModuleKind::Block(..) => {}, // We can see through blocks |
| _ => break, |
| } |
| } |
| |
| ident = modern_ident; |
| let mut poisoned = None; |
| loop { |
| let opt_module = if let Some(node_id) = record_used_id { |
| self.hygienic_lexical_parent_with_compatibility_fallback(module, &mut ident.span, |
| node_id, &mut poisoned) |
| } else { |
| self.hygienic_lexical_parent(module, &mut ident.span) |
| }; |
| module = unwrap_or!(opt_module, break); |
| let adjusted_parent_scope = &ParentScope { module, ..*parent_scope }; |
| let result = self.resolve_ident_in_module_unadjusted( |
| ModuleOrUniformRoot::Module(module), |
| ident, |
| ns, |
| adjusted_parent_scope, |
| record_used, |
| path_span, |
| ); |
| |
| match result { |
| Ok(binding) => { |
| if let Some(node_id) = poisoned { |
| self.session.buffer_lint_with_diagnostic( |
| lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK, |
| node_id, ident.span, |
| &format!("cannot find {} `{}` in this scope", ns.descr(), ident), |
| lint::builtin::BuiltinLintDiagnostics:: |
| ProcMacroDeriveResolutionFallback(ident.span), |
| ); |
| } |
| return Some(LexicalScopeBinding::Item(binding)) |
| } |
| Err(Determined) => continue, |
| Err(Undetermined) => |
| span_bug!(ident.span, "undetermined resolution during main resolution pass"), |
| } |
| } |
| |
| if !module.no_implicit_prelude { |
| ident.span.adjust(ExpnId::root()); |
| if ns == TypeNS { |
| if let Some(binding) = self.extern_prelude_get(ident, !record_used) { |
| return Some(LexicalScopeBinding::Item(binding)); |
| } |
| } |
| if ns == TypeNS && KNOWN_TOOLS.contains(&ident.name) { |
| let binding = (Res::ToolMod, ty::Visibility::Public, |
| DUMMY_SP, ExpnId::root()).to_name_binding(self.arenas); |
| return Some(LexicalScopeBinding::Item(binding)); |
| } |
| if let Some(prelude) = self.prelude { |
| if let Ok(binding) = self.resolve_ident_in_module_unadjusted( |
| ModuleOrUniformRoot::Module(prelude), |
| ident, |
| ns, |
| parent_scope, |
| false, |
| path_span, |
| ) { |
| return Some(LexicalScopeBinding::Item(binding)); |
| } |
| } |
| } |
| |
| None |
| } |
| |
| fn hygienic_lexical_parent(&mut self, module: Module<'a>, span: &mut Span) |
| -> Option<Module<'a>> { |
| if !module.expansion.outer_expn_is_descendant_of(span.ctxt()) { |
| return Some(self.macro_def_scope(span.remove_mark())); |
| } |
| |
| if let ModuleKind::Block(..) = module.kind { |
| return Some(module.parent.unwrap().nearest_item_scope()); |
| } |
| |
| None |
| } |
| |
| fn hygienic_lexical_parent_with_compatibility_fallback(&mut self, module: Module<'a>, |
| span: &mut Span, node_id: NodeId, |
| poisoned: &mut Option<NodeId>) |
| -> Option<Module<'a>> { |
| if let module @ Some(..) = self.hygienic_lexical_parent(module, span) { |
| return module; |
| } |
| |
| // We need to support the next case under a deprecation warning |
| // ``` |
| // struct MyStruct; |
| // ---- begin: this comes from a proc macro derive |
| // mod implementation_details { |
| // // Note that `MyStruct` is not in scope here. |
| // impl SomeTrait for MyStruct { ... } |
| // } |
| // ---- end |
| // ``` |
| // So we have to fall back to the module's parent during lexical resolution in this case. |
| if let Some(parent) = module.parent { |
| // Inner module is inside the macro, parent module is outside of the macro. |
| if module.expansion != parent.expansion && |
| module.expansion.is_descendant_of(parent.expansion) { |
| // The macro is a proc macro derive |
| if let Some(&def_id) = self.macro_defs.get(&module.expansion) { |
| if let Some(ext) = self.get_macro_by_def_id(def_id) { |
| if !ext.is_builtin && ext.macro_kind() == MacroKind::Derive { |
| if parent.expansion.outer_expn_is_descendant_of(span.ctxt()) { |
| *poisoned = Some(node_id); |
| return module.parent; |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| None |
| } |
| |
| fn resolve_ident_in_module( |
| &mut self, |
| module: ModuleOrUniformRoot<'a>, |
| ident: Ident, |
| ns: Namespace, |
| parent_scope: &ParentScope<'a>, |
| record_used: bool, |
| path_span: Span |
| ) -> Result<&'a NameBinding<'a>, Determinacy> { |
| self.resolve_ident_in_module_ext( |
| module, ident, ns, parent_scope, record_used, path_span |
| ).map_err(|(determinacy, _)| determinacy) |
| } |
| |
| fn resolve_ident_in_module_ext( |
| &mut self, |
| module: ModuleOrUniformRoot<'a>, |
| mut ident: Ident, |
| ns: Namespace, |
| parent_scope: &ParentScope<'a>, |
| record_used: bool, |
| path_span: Span |
| ) -> Result<&'a NameBinding<'a>, (Determinacy, Weak)> { |
| let tmp_parent_scope; |
| let mut adjusted_parent_scope = parent_scope; |
| match module { |
| ModuleOrUniformRoot::Module(m) => { |
| if let Some(def) = ident.span.modernize_and_adjust(m.expansion) { |
| tmp_parent_scope = |
| ParentScope { module: self.macro_def_scope(def), ..*parent_scope }; |
| adjusted_parent_scope = &tmp_parent_scope; |
| } |
| } |
| ModuleOrUniformRoot::ExternPrelude => { |
| ident.span.modernize_and_adjust(ExpnId::root()); |
| } |
| ModuleOrUniformRoot::CrateRootAndExternPrelude | |
| ModuleOrUniformRoot::CurrentScope => { |
| // No adjustments |
| } |
| } |
| let result = self.resolve_ident_in_module_unadjusted_ext( |
| module, ident, ns, adjusted_parent_scope, false, record_used, path_span, |
| ); |
| result |
| } |
| |
| fn resolve_crate_root(&mut self, ident: Ident) -> Module<'a> { |
| 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 modern 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.modern_and_legacy(); |
| let mut iter = ctxt.marks().into_iter().rev().peekable(); |
| let mut result = None; |
| // Find the last modern 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; |
| } |
| } |
| // Then find the last legacy mark from the end if it exists. |
| for (mark, transparency) in iter { |
| if transparency == Transparency::SemiTransparent { |
| result = Some(mark); |
| } else { |
| break; |
| } |
| } |
| result |
| } else { |
| ctxt = ctxt.modern(); |
| ctxt.adjust(ExpnId::root()) |
| }; |
| let module = match mark { |
| Some(def) => self.macro_def_scope(def), |
| None => return self.graph_root, |
| }; |
| self.get_module(DefId { index: CRATE_DEF_INDEX, ..module.normal_ancestor_id }) |
| } |
| |
| fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> { |
| let mut module = self.get_module(module.normal_ancestor_id); |
| while module.span.ctxt().modern() != *ctxt { |
| let parent = module.parent.unwrap_or_else(|| self.macro_def_scope(ctxt.remove_mark())); |
| module = self.get_module(parent.normal_ancestor_id); |
| } |
| module |
| } |
| |
| fn resolve_path( |
| &mut self, |
| path: &[Segment], |
| opt_ns: Option<Namespace>, // `None` indicates a module path in import |
| parent_scope: &ParentScope<'a>, |
| record_used: bool, |
| path_span: Span, |
| crate_lint: CrateLint, |
| ) -> PathResult<'a> { |
| self.resolve_path_with_ribs( |
| path, opt_ns, parent_scope, record_used, path_span, crate_lint, None |
| ) |
| } |
| |
| fn resolve_path_with_ribs( |
| &mut self, |
| path: &[Segment], |
| opt_ns: Option<Namespace>, // `None` indicates a module path in import |
| parent_scope: &ParentScope<'a>, |
| record_used: bool, |
| path_span: Span, |
| crate_lint: CrateLint, |
| ribs: Option<&PerNS<Vec<Rib<'a>>>>, |
| ) -> PathResult<'a> { |
| let mut module = None; |
| let mut allow_super = true; |
| let mut second_binding = None; |
| |
| debug!( |
| "resolve_path(path={:?}, opt_ns={:?}, record_used={:?}, \ |
| path_span={:?}, crate_lint={:?})", |
| path, |
| opt_ns, |
| record_used, |
| path_span, |
| crate_lint, |
| ); |
| |
| for (i, &Segment { ident, id }) in path.iter().enumerate() { |
| debug!("resolve_path ident {} {:?} {:?}", i, ident, id); |
| let record_segment_res = |this: &mut Self, res| { |
| if record_used { |
| if let Some(id) = id { |
| if !this.partial_res_map.contains_key(&id) { |
| assert!(id != ast::DUMMY_NODE_ID, "Trying to resolve dummy id"); |
| this.record_partial_res(id, PartialRes::new(res)); |
| } |
| } |
| } |
| }; |
| |
| let is_last = i == path.len() - 1; |
| let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS }; |
| let name = ident.name; |
| |
| allow_super &= ns == TypeNS && |
| (name == kw::SelfLower || |
| name == kw::Super); |
| |
| if ns == TypeNS { |
| if allow_super && name == kw::Super { |
| let mut ctxt = ident.span.ctxt().modern(); |
| let self_module = match i { |
| 0 => Some(self.resolve_self(&mut ctxt, parent_scope.module)), |
| _ => match module { |
| Some(ModuleOrUniformRoot::Module(module)) => Some(module), |
| _ => None, |
| }, |
| }; |
| if let Some(self_module) = self_module { |
| if let Some(parent) = self_module.parent { |
| module = Some(ModuleOrUniformRoot::Module( |
| self.resolve_self(&mut ctxt, parent))); |
| continue; |
| } |
| } |
| let msg = "there are too many initial `super`s.".to_string(); |
| return PathResult::Failed { |
| span: ident.span, |
| label: msg, |
| suggestion: None, |
| is_error_from_last_segment: false, |
| }; |
| } |
| if i == 0 { |
| if name == kw::SelfLower { |
| let mut ctxt = ident.span.ctxt().modern(); |
| module = Some(ModuleOrUniformRoot::Module( |
| self.resolve_self(&mut ctxt, parent_scope.module))); |
| continue; |
| } |
| if name == kw::PathRoot && ident.span.rust_2018() { |
| module = Some(ModuleOrUniformRoot::ExternPrelude); |
| continue; |
| } |
| if name == kw::PathRoot && |
| ident.span.rust_2015() && self.session.rust_2018() { |
| // `::a::b` from 2015 macro on 2018 global edition |
| module = Some(ModuleOrUniformRoot::CrateRootAndExternPrelude); |
| continue; |
| } |
| if name == kw::PathRoot || |
| name == kw::Crate || |
| name == kw::DollarCrate { |
| // `::a::b`, `crate::a::b` or `$crate::a::b` |
| module = Some(ModuleOrUniformRoot::Module( |
| self.resolve_crate_root(ident))); |
| continue; |
| } |
| } |
| } |
| |
| // Report special messages for path segment keywords in wrong positions. |
| if ident.is_path_segment_keyword() && i != 0 { |
| let name_str = if name == kw::PathRoot { |
| "crate root".to_string() |
| } else { |
| format!("`{}`", name) |
| }; |
| let label = if i == 1 && path[0].ident.name == kw::PathRoot { |
| format!("global paths cannot start with {}", name_str) |
| } else { |
| format!("{} in paths can only be used in start position", name_str) |
| }; |
| return PathResult::Failed { |
| span: ident.span, |
| label, |
| suggestion: None, |
| is_error_from_last_segment: false, |
| }; |
| } |
| |
| let binding = if let Some(module) = module { |
| self.resolve_ident_in_module( |
| module, ident, ns, parent_scope, record_used, path_span |
| ) |
| } else if ribs.is_none() || opt_ns.is_none() || opt_ns == Some(MacroNS) { |
| let scopes = ScopeSet::All(ns, opt_ns.is_none()); |
| self.early_resolve_ident_in_lexical_scope(ident, scopes, parent_scope, record_used, |
| record_used, path_span) |
| } else { |
| let record_used_id = |
| if record_used { crate_lint.node_id().or(Some(CRATE_NODE_ID)) } else { None }; |
| match self.resolve_ident_in_lexical_scope( |
| ident, ns, parent_scope, record_used_id, path_span, &ribs.unwrap()[ns] |
| ) { |
| // we found a locally-imported or available item/module |
| Some(LexicalScopeBinding::Item(binding)) => Ok(binding), |
| // we found a local variable or type param |
| Some(LexicalScopeBinding::Res(res)) |
| if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) => { |
| record_segment_res(self, res); |
| return PathResult::NonModule(PartialRes::with_unresolved_segments( |
| res, path.len() - 1 |
| )); |
| } |
| _ => Err(Determinacy::determined(record_used)), |
| } |
| }; |
| |
| match binding { |
| Ok(binding) => { |
| if i == 1 { |
| second_binding = Some(binding); |
| } |
| let res = binding.res(); |
| let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(res); |
| if let Some(next_module) = binding.module() { |
| module = Some(ModuleOrUniformRoot::Module(next_module)); |
| record_segment_res(self, res); |
| } else if res == Res::ToolMod && i + 1 != path.len() { |
| if binding.is_import() { |
| self.session.struct_span_err( |
| ident.span, "cannot use a tool module through an import" |
| ).span_note( |
| binding.span, "the tool module imported here" |
| ).emit(); |
| } |
| let res = Res::NonMacroAttr(NonMacroAttrKind::Tool); |
| return PathResult::NonModule(PartialRes::new(res)); |
| } else if res == Res::Err { |
| return PathResult::NonModule(PartialRes::new(Res::Err)); |
| } else if opt_ns.is_some() && (is_last || maybe_assoc) { |
| self.lint_if_path_starts_with_module( |
| crate_lint, |
| path, |
| path_span, |
| second_binding, |
| ); |
| return PathResult::NonModule(PartialRes::with_unresolved_segments( |
| res, path.len() - i - 1 |
| )); |
| } else { |
| let label = format!( |
| "`{}` is {} {}, not a module", |
| ident, |
| res.article(), |
| res.descr(), |
| ); |
| |
| return PathResult::Failed { |
| span: ident.span, |
| label, |
| suggestion: None, |
| is_error_from_last_segment: is_last, |
| }; |
| } |
| } |
| Err(Undetermined) => return PathResult::Indeterminate, |
| Err(Determined) => { |
| if let Some(ModuleOrUniformRoot::Module(module)) = module { |
| if opt_ns.is_some() && !module.is_normal() { |
| return PathResult::NonModule(PartialRes::with_unresolved_segments( |
| module.res().unwrap(), path.len() - i |
| )); |
| } |
| } |
| let module_res = match module { |
| Some(ModuleOrUniformRoot::Module(module)) => module.res(), |
| _ => None, |
| }; |
| let (label, suggestion) = if module_res == self.graph_root.res() { |
| let is_mod = |res| { |
| match res { Res::Def(DefKind::Mod, _) => true, _ => false } |
| }; |
| let mut candidates = |
| self.lookup_import_candidates(ident, TypeNS, is_mod); |
| candidates.sort_by_cached_key(|c| { |
| (c.path.segments.len(), c.path.to_string()) |
| }); |
| if let Some(candidate) = candidates.get(0) { |
| ( |
| String::from("unresolved import"), |
| Some(( |
| vec![(ident.span, candidate.path.to_string())], |
| String::from("a similar path exists"), |
| Applicability::MaybeIncorrect, |
| )), |
| ) |
| } else if !ident.is_reserved() { |
| (format!("maybe a missing crate `{}`?", ident), None) |
| } else { |
| // the parser will already have complained about the keyword being used |
| return PathResult::NonModule(PartialRes::new(Res::Err)); |
| } |
| } else if i == 0 { |
| (format!("use of undeclared type or module `{}`", ident), None) |
| } else { |
| (format!("could not find `{}` in `{}`", ident, path[i - 1].ident), None) |
| }; |
| return PathResult::Failed { |
| span: ident.span, |
| label, |
| suggestion, |
| is_error_from_last_segment: is_last, |
| }; |
| } |
| } |
| } |
| |
| self.lint_if_path_starts_with_module(crate_lint, path, path_span, second_binding); |
| |
| PathResult::Module(match module { |
| Some(module) => module, |
| None if path.is_empty() => ModuleOrUniformRoot::CurrentScope, |
| _ => span_bug!(path_span, "resolve_path: non-empty path `{:?}` has no module", path), |
| }) |
| } |
| |
| fn lint_if_path_starts_with_module( |
| &self, |
| crate_lint: CrateLint, |
| path: &[Segment], |
| path_span: Span, |
| second_binding: Option<&NameBinding<'_>>, |
| ) { |
| let (diag_id, diag_span) = match crate_lint { |
| CrateLint::No => return, |
| CrateLint::SimplePath(id) => (id, path_span), |
| CrateLint::UsePath { root_id, root_span } => (root_id, root_span), |
| CrateLint::QPathTrait { qpath_id, qpath_span } => (qpath_id, qpath_span), |
| }; |
| |
| let first_name = match path.get(0) { |
| // In the 2018 edition this lint is a hard error, so nothing to do |
| Some(seg) if seg.ident.span.rust_2015() && self.session.rust_2015() => seg.ident.name, |
| _ => return, |
| }; |
| |
| // We're only interested in `use` paths which should start with |
| // `{{root}}` currently. |
| if first_name != kw::PathRoot { |
| return |
| } |
| |
| match path.get(1) { |
| // If this import looks like `crate::...` it's already good |
| Some(Segment { ident, .. }) if ident.name == kw::Crate => return, |
| // Otherwise go below to see if it's an extern crate |
| Some(_) => {} |
| // If the path has length one (and it's `PathRoot` most likely) |
| // then we don't know whether we're gonna be importing a crate or an |
| // item in our crate. Defer this lint to elsewhere |
| None => return, |
| } |
| |
| // If the first element of our path was actually resolved to an |
| // `ExternCrate` (also used for `crate::...`) then no need to issue a |
| // warning, this looks all good! |
| if let Some(binding) = second_binding { |
| if let NameBindingKind::Import { directive: d, .. } = binding.kind { |
| // Careful: we still want to rewrite paths from |
| // renamed extern crates. |
| if let ImportDirectiveSubclass::ExternCrate { source: None, .. } = d.subclass { |
| return |
| } |
| } |
| } |
| |
| let diag = lint::builtin::BuiltinLintDiagnostics |
| ::AbsPathWithModule(diag_span); |
| self.session.buffer_lint_with_diagnostic( |
| lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE, |
| diag_id, diag_span, |
| "absolute paths must start with `self`, `super`, \ |
| `crate`, or an external crate name in the 2018 edition", |
| diag); |
| } |
| |
| // Validate a local resolution (from ribs). |
| fn validate_res_from_ribs( |
| &mut self, |
| rib_index: usize, |
| res: Res, |
| record_used: bool, |
| span: Span, |
| all_ribs: &[Rib<'a>], |
| ) -> Res { |
| debug!("validate_res_from_ribs({:?})", res); |
| let ribs = &all_ribs[rib_index + 1..]; |
| |
| // An invalid forward use of a type parameter from a previous default. |
| if let ForwardTyParamBanRibKind = all_ribs[rib_index].kind { |
| if record_used { |
| self.report_error(span, ResolutionError::ForwardDeclaredTyParam); |
| } |
| assert_eq!(res, Res::Err); |
| return Res::Err; |
| } |
| |
| // An invalid use of a type parameter as the type of a const parameter. |
| if let TyParamAsConstParamTy = all_ribs[rib_index].kind { |
| if record_used { |
| self.report_error(span, ResolutionError::ConstParamDependentOnTypeParam); |
| } |
| assert_eq!(res, Res::Err); |
| return Res::Err; |
| } |
| |
| match res { |
| Res::Local(_) => { |
| use ResolutionError::*; |
| let mut res_err = None; |
| |
| for rib in ribs { |
| match rib.kind { |
| NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) | |
| ForwardTyParamBanRibKind | TyParamAsConstParamTy => { |
| // Nothing to do. Continue. |
| } |
| ItemRibKind | FnItemRibKind | AssocItemRibKind => { |
| // This was an attempt to access an upvar inside a |
| // named function item. This is not allowed, so we |
| // report an error. |
| if record_used { |
| // We don't immediately trigger a resolve error, because |
| // we want certain other resolution errors (namely those |
| // emitted for `ConstantItemRibKind` below) to take |
| // precedence. |
| res_err = Some(CannotCaptureDynamicEnvironmentInFnItem); |
| } |
| } |
| ConstantItemRibKind => { |
| // Still doesn't deal with upvars |
| if record_used { |
| self.report_error(span, AttemptToUseNonConstantValueInConstant); |
| } |
| return Res::Err; |
| } |
| } |
| } |
| if let Some(res_err) = res_err { |
| self.report_error(span, res_err); |
| return Res::Err; |
| } |
| } |
| Res::Def(DefKind::TyParam, _) | Res::SelfTy(..) => { |
| for rib in ribs { |
| match rib.kind { |
| NormalRibKind | AssocItemRibKind | |
| ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind | |
| ConstantItemRibKind | TyParamAsConstParamTy => { |
| // Nothing to do. Continue. |
| } |
| ItemRibKind | FnItemRibKind => { |
| // This was an attempt to use a type parameter outside its scope. |
| if record_used { |
| self.report_error( |
| span, ResolutionError::GenericParamsFromOuterFunction(res) |
| ); |
| } |
| return Res::Err; |
| } |
| } |
| } |
| } |
| Res::Def(DefKind::ConstParam, _) => { |
| let mut ribs = ribs.iter().peekable(); |
| if let Some(Rib { kind: FnItemRibKind, .. }) = ribs.peek() { |
| // When declaring const parameters inside function signatures, the first rib |
| // is always a `FnItemRibKind`. In this case, we can skip it, to avoid it |
| // (spuriously) conflicting with the const param. |
| ribs.next(); |
| } |
| for rib in ribs { |
| if let ItemRibKind | FnItemRibKind = rib.kind { |
| // This was an attempt to use a const parameter outside its scope. |
| if record_used { |
| self.report_error( |
| span, ResolutionError::GenericParamsFromOuterFunction(res) |
| ); |
| } |
| return Res::Err; |
| } |
| } |
| } |
| _ => {} |
| } |
| res |
| } |
| |
| 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 ({:?} before, {:?} now)", prev_res, resolution); |
| } |
| } |
| |
| fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool { |
| vis.is_accessible_from(module.normal_ancestor_id, self) |
| } |
| |
| fn set_binding_parent_module(&mut self, binding: &'a NameBinding<'a>, module: Module<'a>) { |
| if let Some(old_module) = self.binding_parent_modules.insert(PtrKey(binding), module) { |
| if !ptr::eq(module, old_module) { |
| span_bug!(binding.span, "parent module is reset for binding"); |
| } |
| } |
| } |
| |
| fn disambiguate_legacy_vs_modern( |
| &self, |
| legacy: &'a NameBinding<'a>, |
| modern: &'a NameBinding<'a>, |
| ) -> bool { |
| // Some non-controversial subset of ambiguities "modern 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(&PtrKey(legacy)), |
| self.binding_parent_modules.get(&PtrKey(modern))) { |
| (Some(legacy), Some(modern)) => |
| legacy.normal_ancestor_id == modern.normal_ancestor_id && |
| modern.is_ancestor_of(legacy), |
| _ => false, |
| } |
| } |
| |
| fn binding_description(&self, b: &NameBinding<'_>, ident: Ident, from_prelude: bool) -> String { |
| let res = b.res(); |
| if b.span.is_dummy() { |
| let add_built_in = match b.res() { |
| // These already contain the "built-in" prefix or look bad with it. |
| Res::NonMacroAttr(..) | Res::PrimTy(..) | Res::ToolMod => false, |
| _ => true, |
| }; |
| let (built_in, from) = if from_prelude { |
| ("", " from prelude") |
| } else if b.is_extern_crate() && !b.is_import() && |
| self.session.opts.externs.get(&ident.as_str()).is_some() { |
| ("", " passed with `--extern`") |
| } else if add_built_in { |
| (" built-in", "") |
| } else { |
| ("", "") |
| }; |
| |
| let article = if built_in.is_empty() { res.article() } else { "a" }; |
| format!("{a}{built_in} {thing}{from}", |
| a = article, thing = res.descr(), built_in = built_in, from = from) |
| } else { |
| let introduced = if b.is_import() { "imported" } else { "defined" }; |
| format!("the {thing} {introduced} here", |
| thing = res.descr(), introduced = introduced) |
| } |
| } |
| |
| fn report_ambiguity_error(&self, ambiguity_error: &AmbiguityError<'_>) { |
| let AmbiguityError { kind, ident, b1, b2, misc1, misc2 } = *ambiguity_error; |
| let (b1, b2, misc1, misc2, swapped) = if b2.span.is_dummy() && !b1.span.is_dummy() { |
| // We have to print the span-less alternative first, otherwise formatting looks bad. |
| (b2, b1, misc2, misc1, true) |
| } else { |
| (b1, b2, misc1, misc2, false) |
| }; |
| |
| let mut err = struct_span_err!(self.session, ident.span, E0659, |
| "`{ident}` is ambiguous ({why})", |
| ident = ident, why = kind.descr()); |
| err.span_label(ident.span, "ambiguous name"); |
| |
| let mut could_refer_to = |b: &NameBinding<'_>, misc: AmbiguityErrorMisc, also: &str| { |
| let what = self.binding_description(b, ident, misc == AmbiguityErrorMisc::FromPrelude); |
| let note_msg = format!("`{ident}` could{also} refer to {what}", |
| ident = ident, also = also, what = what); |
| |
| let thing = b.res().descr(); |
| let mut help_msgs = Vec::new(); |
| if b.is_glob_import() && (kind == AmbiguityKind::GlobVsGlob || |
| kind == AmbiguityKind::GlobVsExpanded || |
| kind == AmbiguityKind::GlobVsOuter && |
| swapped != also.is_empty()) { |
| help_msgs.push(format!("consider adding an explicit import of \ |
| `{ident}` to disambiguate", ident = ident)) |
| } |
| if b.is_extern_crate() && ident.span.rust_2018() { |
| help_msgs.push(format!( |
| "use `::{ident}` to refer to this {thing} unambiguously", |
| ident = ident, thing = thing, |
| )) |
| } |
| if misc == AmbiguityErrorMisc::SuggestCrate { |
| help_msgs.push(format!( |
| "use `crate::{ident}` to refer to this {thing} unambiguously", |
| ident = ident, thing = thing, |
| )) |
| } else if misc == AmbiguityErrorMisc::SuggestSelf { |
| help_msgs.push(format!( |
| "use `self::{ident}` to refer to this {thing} unambiguously", |
| ident = ident, thing = thing, |
| )) |
| } |
| |
| err.span_note(b.span, ¬e_msg); |
| for (i, help_msg) in help_msgs.iter().enumerate() { |
| let or = if i == 0 { "" } else { "or " }; |
| err.help(&format!("{}{}", or, help_msg)); |
| } |
| }; |
| |
| could_refer_to(b1, misc1, ""); |
| could_refer_to(b2, misc2, " also"); |
| err.emit(); |
| } |
| |
| fn report_errors(&mut self, krate: &Crate) { |
| self.report_with_use_injections(krate); |
| |
| for &(span_use, span_def) in &self.macro_expanded_macro_export_errors { |
| let msg = "macro-expanded `macro_export` macros from the current crate \ |
| cannot be referred to by absolute paths"; |
| self.session.buffer_lint_with_diagnostic( |
| lint::builtin::MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS, |
| CRATE_NODE_ID, span_use, msg, |
| lint::builtin::BuiltinLintDiagnostics:: |
| MacroExpandedMacroExportsAccessedByAbsolutePaths(span_def), |
| ); |
| } |
| |
| for ambiguity_error in &self.ambiguity_errors { |
| self.report_ambiguity_error(ambiguity_error); |
| } |
| |
| let mut reported_spans = FxHashSet::default(); |
| for &PrivacyError(dedup_span, ident, binding) in &self.privacy_errors { |
| if reported_spans.insert(dedup_span) { |
| let mut err = struct_span_err!( |
| self.session, |
| ident.span, |
| E0603, |
| "{} `{}` is private", |
| binding.res().descr(), |
| ident.name, |
| ); |
| // FIXME: use the ctor's `def_id` to check wether any of the fields is not visible |
| match binding.kind { |
| NameBindingKind::Res(Res::Def(DefKind::Ctor( |
| CtorOf::Struct, |
| CtorKind::Fn, |
| ), _def_id), _) => { |
| err.note("a tuple struct constructor is private if any of its fields \ |
| is private"); |
| } |
| NameBindingKind::Res(Res::Def(DefKind::Ctor( |
| CtorOf::Variant, |
| CtorKind::Fn, |
| ), _def_id), _) => { |
| err.note("a tuple variant constructor is private if any of its fields \ |
| is private"); |
| } |
| _ => {} |
| } |
| err.emit(); |
| } |
| } |
| } |
| |
| fn report_with_use_injections(&mut self, krate: &Crate) { |
| for UseError { mut err, candidates, node_id, better } in self.use_injections.drain(..) { |
| let (span, found_use) = UsePlacementFinder::check(krate, node_id); |
| if !candidates.is_empty() { |
| diagnostics::show_candidates(&mut err, span, &candidates, better, found_use); |
| } |
| err.emit(); |
| } |
| } |
| |
| fn report_conflict<'b>(&mut self, |
| parent: Module<'_>, |
| ident: Ident, |
| ns: Namespace, |
| new_binding: &NameBinding<'b>, |
| old_binding: &NameBinding<'b>) { |
| // Error on the second of two conflicting names |
| if old_binding.span.lo() > new_binding.span.lo() { |
| return self.report_conflict(parent, ident, ns, old_binding, new_binding); |
| } |
| |
| let container = match parent.kind { |
| ModuleKind::Def(DefKind::Mod, _, _) => "module", |
| ModuleKind::Def(DefKind::Trait, _, _) => "trait", |
| ModuleKind::Block(..) => "block", |
| _ => "enum", |
| }; |
| |
| let old_noun = match old_binding.is_import() { |
| true => "import", |
| false => "definition", |
| }; |
| |
| let new_participle = match new_binding.is_import() { |
| true => "imported", |
| false => "defined", |
| }; |
| |
| let (name, span) = (ident.name, self.session.source_map().def_span(new_binding.span)); |
| |
| if let Some(s) = self.name_already_seen.get(&name) { |
| if s == &span { |
| return; |
| } |
| } |
| |
| let old_kind = match (ns, old_binding.module()) { |
| (ValueNS, _) => "value", |
| (MacroNS, _) => "macro", |
| (TypeNS, _) if old_binding.is_extern_crate() => "extern crate", |
| (TypeNS, Some(module)) if module.is_normal() => "module", |
| (TypeNS, Some(module)) if module.is_trait() => "trait", |
| (TypeNS, _) => "type", |
| }; |
| |
| let msg = format!("the name `{}` is defined multiple times", name); |
| |
| let mut err = match (old_binding.is_extern_crate(), new_binding.is_extern_crate()) { |
| (true, true) => struct_span_err!(self.session, span, E0259, "{}", msg), |
| (true, _) | (_, true) => match new_binding.is_import() && old_binding.is_import() { |
| true => struct_span_err!(self.session, span, E0254, "{}", msg), |
| false => struct_span_err!(self.session, span, E0260, "{}", msg), |
| }, |
| _ => match (old_binding.is_import(), new_binding.is_import()) { |
| (false, false) => struct_span_err!(self.session, span, E0428, "{}", msg), |
| (true, true) => struct_span_err!(self.session, span, E0252, "{}", msg), |
| _ => struct_span_err!(self.session, span, E0255, "{}", msg), |
| }, |
| }; |
| |
| err.note(&format!("`{}` must be defined only once in the {} namespace of this {}", |
| name, |
| ns.descr(), |
| container)); |
| |
| err.span_label(span, format!("`{}` re{} here", name, new_participle)); |
| err.span_label( |
| self.session.source_map().def_span(old_binding.span), |
| format!("previous {} of the {} `{}` here", old_noun, old_kind, name), |
| ); |
| |
| // See https://github.com/rust-lang/rust/issues/32354 |
| use NameBindingKind::Import; |
| let directive = match (&new_binding.kind, &old_binding.kind) { |
| // If there are two imports where one or both have attributes then prefer removing the |
| // import without attributes. |
| (Import { directive: new, .. }, Import { directive: old, .. }) if { |
| !new_binding.span.is_dummy() && !old_binding.span.is_dummy() && |
| (new.has_attributes || old.has_attributes) |
| } => { |
| if old.has_attributes { |
| Some((new, new_binding.span, true)) |
| } else { |
| Some((old, old_binding.span, true)) |
| } |
| }, |
| // Otherwise prioritize the new binding. |
| (Import { directive, .. }, other) if !new_binding.span.is_dummy() => |
| Some((directive, new_binding.span, other.is_import())), |
| (other, Import { directive, .. }) if !old_binding.span.is_dummy() => |
| Some((directive, old_binding.span, other.is_import())), |
| _ => None, |
| }; |
| |
| // Check if the target of the use for both bindings is the same. |
| let duplicate = new_binding.res().opt_def_id() == old_binding.res().opt_def_id(); |
| let has_dummy_span = new_binding.span.is_dummy() || old_binding.span.is_dummy(); |
| let from_item = self.extern_prelude.get(&ident) |
| .map(|entry| entry.introduced_by_item) |
| .unwrap_or(true); |
| // Only suggest removing an import if both bindings are to the same def, if both spans |
| // aren't dummy spans. Further, if both bindings are imports, then the ident must have |
| // been introduced by a item. |
| let should_remove_import = duplicate && !has_dummy_span && |
| ((new_binding.is_extern_crate() || old_binding.is_extern_crate()) || from_item); |
| |
| match directive { |
| Some((directive, span, true)) if should_remove_import && directive.is_nested() => |
| self.add_suggestion_for_duplicate_nested_use(&mut err, directive, span), |
| Some((directive, _, true)) if should_remove_import && !directive.is_glob() => { |
| // Simple case - remove the entire import. Due to the above match arm, this can |
| // only be a single use so just remove it entirely. |
| err.tool_only_span_suggestion( |
| directive.use_span_with_attributes, |
| "remove unnecessary import", |
| String::new(), |
| Applicability::MaybeIncorrect, |
| ); |
| }, |
| Some((directive, span, _)) => |
| self.add_suggestion_for_rename_of_use(&mut err, name, directive, span), |
| _ => {}, |
| } |
| |
| err.emit(); |
| self.name_already_seen.insert(name, span); |
| } |
| |
| /// This function adds a suggestion to change the binding name of a new import that conflicts |
| /// with an existing import. |
| /// |
| /// ```ignore (diagnostic) |
| /// help: you can use `as` to change the binding name of the import |
| /// | |
| /// LL | use foo::bar as other_bar; |
| /// | ^^^^^^^^^^^^^^^^^^^^^ |
| /// ``` |
| fn add_suggestion_for_rename_of_use( |
| &self, |
| err: &mut DiagnosticBuilder<'_>, |
| name: Symbol, |
| directive: &ImportDirective<'_>, |
| binding_span: Span, |
| ) { |
| let suggested_name = if name.as_str().chars().next().unwrap().is_uppercase() { |
| format!("Other{}", name) |
| } else { |
| format!("other_{}", name) |
| }; |
| |
| let mut suggestion = None; |
| match directive.subclass { |
| ImportDirectiveSubclass::SingleImport { type_ns_only: true, .. } => |
| suggestion = Some(format!("self as {}", suggested_name)), |
| ImportDirectiveSubclass::SingleImport { source, .. } => { |
| if let Some(pos) = source.span.hi().0.checked_sub(binding_span.lo().0) |
| .map(|pos| pos as usize) { |
| if let Ok(snippet) = self.session.source_map() |
| .span_to_snippet(binding_span) { |
| if pos <= snippet.len() { |
| suggestion = Some(format!( |
| "{} as {}{}", |
| &snippet[..pos], |
| suggested_name, |
| if snippet.ends_with(";") { ";" } else { "" } |
| )) |
| } |
| } |
| } |
| } |
| ImportDirectiveSubclass::ExternCrate { source, target, .. } => |
| suggestion = Some(format!( |
| "extern crate {} as {};", |
| source.unwrap_or(target.name), |
| suggested_name, |
| )), |
| _ => unreachable!(), |
| } |
| |
| let rename_msg = "you can use `as` to change the binding name of the import"; |
| if let Some(suggestion) = suggestion { |
| err.span_suggestion( |
| binding_span, |
| rename_msg, |
| suggestion, |
| Applicability::MaybeIncorrect, |
| ); |
| } else { |
| err.span_label(binding_span, rename_msg); |
| } |
| } |
| |
| /// This function adds a suggestion to remove a unnecessary binding from an import that is |
| /// nested. In the following example, this function will be invoked to remove the `a` binding |
| /// in the second use statement: |
| /// |
| /// ```ignore (diagnostic) |
| /// use issue_52891::a; |
| /// use issue_52891::{d, a, e}; |
| /// ``` |
| /// |
| /// The following suggestion will be added: |
| /// |
| /// ```ignore (diagnostic) |
| /// use issue_52891::{d, a, e}; |
| /// ^-- help: remove unnecessary import |
| /// ``` |
| /// |
| /// If the nested use contains only one import then the suggestion will remove the entire |
| /// line. |
| /// |
| /// It is expected that the directive provided is a nested import - this isn't checked by the |
| /// function. If this invariant is not upheld, this function's behaviour will be unexpected |
| /// as characters expected by span manipulations won't be present. |
| fn add_suggestion_for_duplicate_nested_use( |
| &self, |
| err: &mut DiagnosticBuilder<'_>, |
| directive: &ImportDirective<'_>, |
| binding_span: Span, |
| ) { |
| assert!(directive.is_nested()); |
| let message = "remove unnecessary import"; |
| |
| // Two examples will be used to illustrate the span manipulations we're doing: |
| // |
| // - Given `use issue_52891::{d, a, e};` where `a` is a duplicate then `binding_span` is |
| // `a` and `directive.use_span` is `issue_52891::{d, a, e};`. |
| // - Given `use issue_52891::{d, e, a};` where `a` is a duplicate then `binding_span` is |
| // `a` and `directive.use_span` is `issue_52891::{d, e, a};`. |
| |
| let (found_closing_brace, span) = find_span_of_binding_until_next_binding( |
| self.session, binding_span, directive.use_span, |
| ); |
| |
| // If there was a closing brace then identify the span to remove any trailing commas from |
| // previous imports. |
| if found_closing_brace { |
| if let Some(span) = extend_span_to_previous_binding(self.session, span) { |
| err.tool_only_span_suggestion(span, message, String::new(), |
| Applicability::MaybeIncorrect); |
| } else { |
| // Remove the entire line if we cannot extend the span back, this indicates a |
| // `issue_52891::{self}` case. |
| err.span_suggestion(directive.use_span_with_attributes, message, String::new(), |
| Applicability::MaybeIncorrect); |
| } |
| |
| return; |
| } |
| |
| err.span_suggestion(span, message, String::new(), Applicability::MachineApplicable); |
| } |
| |
| fn extern_prelude_get(&mut self, ident: Ident, speculative: bool) |
| -> Option<&'a NameBinding<'a>> { |
| if ident.is_path_segment_keyword() { |
| // Make sure `self`, `super` etc produce an error when passed to here. |
| return None; |
| } |
| self.extern_prelude.get(&ident.modern()).cloned().and_then(|entry| { |
| if let Some(binding) = entry.extern_crate_item { |
| if !speculative && entry.introduced_by_item { |
| self.record_use(ident, TypeNS, binding, false); |
| } |
| Some(binding) |
| } else { |
| let crate_id = if !speculative { |
| self.crate_loader.process_path_extern(ident.name, ident.span) |
| } else if let Some(crate_id) = |
| self.crate_loader.maybe_process_path_extern(ident.name, ident.span) { |
| crate_id |
| } else { |
| return None; |
| }; |
| let crate_root = self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX }); |
| Some((crate_root, ty::Visibility::Public, DUMMY_SP, ExpnId::root()) |
| .to_name_binding(self.arenas)) |
| } |
| }) |
| } |
| |
| /// Rustdoc uses this to resolve things in a recoverable way. `ResolutionError<'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. |
| // FIXME(Manishearth): intra-doc links won't get warned of epoch changes. |
| pub fn resolve_str_path_error( |
| &mut self, span: Span, path_str: &str, ns: Namespace, module_id: NodeId |
| ) -> Result<(ast::Path, Res), ()> { |
| let path = if path_str.starts_with("::") { |
| ast::Path { |
| span, |
| segments: iter::once(Ident::with_dummy_span(kw::PathRoot)) |
| .chain({ |
| path_str.split("::").skip(1).map(Ident::from_str) |
| }) |
| .map(|i| self.new_ast_path_segment(i)) |
| .collect(), |
| } |
| } else { |
| ast::Path { |
| span, |
| segments: path_str |
| .split("::") |
| .map(Ident::from_str) |
| .map(|i| self.new_ast_path_segment(i)) |
| .collect(), |
| } |
| }; |
| let module = self.block_map.get(&module_id).copied().unwrap_or_else(|| { |
| let def_id = self.definitions.local_def_id(module_id); |
| self.module_map.get(&def_id).copied().unwrap_or(self.graph_root) |
| }); |
| let parent_scope = &ParentScope::module(module); |
| let res = self.resolve_ast_path(&path, ns, parent_scope).map_err(|_| ())?; |
| Ok((path, res)) |
| } |
| |
| // Resolve a path passed from rustdoc or HIR lowering. |
| fn resolve_ast_path( |
| &mut self, |
| path: &ast::Path, |
| ns: Namespace, |
| parent_scope: &ParentScope<'a>, |
| ) -> Result<Res, (Span, ResolutionError<'a>)> { |
| match self.resolve_path( |
| &Segment::from_path(path), Some(ns), parent_scope, true, path.span, CrateLint::No |
| ) { |
| PathResult::Module(ModuleOrUniformRoot::Module(module)) => |
| Ok(module.res().unwrap()), |
| PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 => |
| Ok(path_res.base_res()), |
| PathResult::NonModule(..) => { |
| Err((path.span, ResolutionError::FailedToResolve { |
| label: String::from("type-relative paths are not supported in this context"), |
| suggestion: None, |
| })) |
| } |
| PathResult::Module(..) | PathResult::Indeterminate => unreachable!(), |
| PathResult::Failed { span, label, suggestion, .. } => { |
| Err((span, ResolutionError::FailedToResolve { |
| label, |
| suggestion, |
| })) |
| } |
| } |
| } |
| |
| fn new_ast_path_segment(&self, ident: Ident) -> ast::PathSegment { |
| let mut seg = ast::PathSegment::from_ident(ident); |
| seg.id = self.session.next_node_id(); |
| seg |
| } |
| } |
| |
| fn names_to_string(idents: &[Ident]) -> String { |
| let mut result = String::new(); |
| for (i, ident) in idents.iter() |
| .filter(|ident| ident.name != kw::PathRoot) |
| .enumerate() { |
| if i > 0 { |
| result.push_str("::"); |
| } |
| result.push_str(&ident.as_str()); |
| } |
| result |
| } |
| |
| fn path_names_to_string(path: &Path) -> String { |
| names_to_string(&path.segments.iter() |
| .map(|seg| seg.ident) |
| .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<Ident>, module: Module<'_>) { |
| if let ModuleKind::Def(.., name) = module.kind { |
| if let Some(parent) = module.parent { |
| names.push(Ident::with_dummy_span(name)); |
| collect_mod(names, parent); |
| } |
| } else { |
| // danger, shouldn't be ident? |
| names.push(Ident::from_str("<opaque>")); |
| collect_mod(names, module.parent.unwrap()); |
| } |
| } |
| collect_mod(&mut names, module); |
| |
| if names.is_empty() { |
| return None; |
| } |
| Some(names_to_string(&names.into_iter() |
| .rev() |
| .collect::<Vec<_>>())) |
| } |
| |
| #[derive(Copy, Clone, Debug)] |
| enum CrateLint { |
| /// Do not issue the lint. |
| No, |
| |
| /// This lint applies to some arbitrary path; e.g., `impl ::foo::Bar`. |
| /// In this case, we can take the span of that path. |
| SimplePath(NodeId), |
| |
| /// This lint comes from a `use` statement. In this case, what we |
| /// care about really is the *root* `use` statement; e.g., if we |
| /// have nested things like `use a::{b, c}`, we care about the |
| /// `use a` part. |
| UsePath { root_id: NodeId, root_span: Span }, |
| |
| /// This is the "trait item" from a fully qualified path. For example, |
| /// we might be resolving `X::Y::Z` from a path like `<T as X::Y>::Z`. |
| /// The `path_span` is the span of the to the trait itself (`X::Y`). |
| QPathTrait { qpath_id: NodeId, qpath_span: Span }, |
| } |
| |
| impl CrateLint { |
| fn node_id(&self) -> Option<NodeId> { |
| match *self { |
| CrateLint::No => None, |
| CrateLint::SimplePath(id) | |
| CrateLint::UsePath { root_id: id, .. } | |
| CrateLint::QPathTrait { qpath_id: id, .. } => Some(id), |
| } |
| } |
| } |