| // ignore-tidy-filelength |
| |
| #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")] |
| |
| #![feature(crate_visibility_modifier)] |
| #![feature(label_break_value)] |
| #![feature(nll)] |
| #![feature(rustc_diagnostic_macros)] |
| #![feature(type_alias_enum_variants)] |
| |
| #![recursion_limit="256"] |
| |
| #![deny(rust_2018_idioms)] |
| #![deny(internal)] |
| #![deny(unused_lifetimes)] |
| |
| pub use rustc::hir::def::{Namespace, PerNS}; |
| |
| use GenericParameters::*; |
| use RibKind::*; |
| use smallvec::smallvec; |
| |
| use rustc::hir::map::{Definitions, DefCollector}; |
| 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::{TraitCandidate, TraitMap, GlobMap}; |
| use rustc::ty::{self, DefIdTree}; |
| use rustc::util::nodemap::{NodeMap, NodeSet, FxHashMap, FxHashSet, DefIdMap}; |
| use rustc::{bug, span_bug}; |
| |
| use rustc_metadata::creader::CrateLoader; |
| use rustc_metadata::cstore::CStore; |
| |
| use syntax::source_map::SourceMap; |
| use syntax::ext::hygiene::{Mark, Transparency, SyntaxContext}; |
| use syntax::ast::{self, Name, NodeId, Ident, FloatTy, IntTy, UintTy}; |
| use syntax::ext::base::{SyntaxExtension, SyntaxExtensionKind}; |
| use syntax::ext::base::Determinacy::{self, Determined, Undetermined}; |
| use syntax::ext::base::MacroKind; |
| use syntax::symbol::{Symbol, kw, sym}; |
| use syntax::util::lev_distance::find_best_match_for_name; |
| |
| use syntax::visit::{self, FnKind, Visitor}; |
| use syntax::attr; |
| use syntax::ast::{CRATE_NODE_ID, Arm, IsAsync, BindingMode, Block, Crate, Expr, ExprKind}; |
| use syntax::ast::{FnDecl, ForeignItem, ForeignItemKind, GenericParamKind, Generics}; |
| use syntax::ast::{Item, ItemKind, ImplItem, ImplItemKind}; |
| use syntax::ast::{Label, Local, Mutability, Pat, PatKind, Path}; |
| use syntax::ast::{QSelf, TraitItemKind, TraitRef, Ty, TyKind}; |
| use syntax::ptr::P; |
| use syntax::{span_err, struct_span_err, unwrap_or, walk_list}; |
| |
| use syntax_pos::{Span, DUMMY_SP, MultiSpan}; |
| use errors::{Applicability, DiagnosticBuilder, DiagnosticId}; |
| |
| use log::debug; |
| |
| use std::cell::{Cell, RefCell}; |
| use std::{cmp, fmt, iter, mem, ptr}; |
| use std::collections::BTreeSet; |
| use std::mem::replace; |
| use rustc_data_structures::ptr_key::PtrKey; |
| use rustc_data_structures::sync::Lrc; |
| use smallvec::SmallVec; |
| |
| use diagnostics::{find_span_of_binding_until_next_binding, extend_span_to_previous_binding}; |
| use resolve_imports::{ImportDirective, ImportDirectiveSubclass, NameResolution, ImportResolver}; |
| use macros::{InvocationData, LegacyBinding, ParentScope}; |
| |
| type Res = def::Res<NodeId>; |
| |
| // N.B., this module needs to be declared first so diagnostics are |
| // registered before they are used. |
| mod error_codes; |
| mod diagnostics; |
| mod macros; |
| mod check_unused; |
| mod build_reduced_graph; |
| mod resolve_imports; |
| |
| fn is_known_tool(name: Name) -> bool { |
| ["clippy", "rustfmt"].contains(&&*name.as_str()) |
| } |
| |
| enum Weak { |
| Yes, |
| No, |
| } |
| |
| enum ScopeSet { |
| Import(Namespace), |
| AbsolutePath(Namespace), |
| Macro(MacroKind), |
| Module, |
| } |
| |
| /// A free importable items suggested in case of resolution failure. |
| struct ImportSuggestion { |
| did: Option<DefId>, |
| path: Path, |
| } |
| |
| /// A field or associated item from self type suggested in case of resolution failure. |
| enum AssocSuggestion { |
| Field, |
| MethodWithSelf, |
| AssocItem, |
| } |
| |
| #[derive(Eq)] |
| struct BindingError { |
| name: Name, |
| origin: BTreeSet<Span>, |
| target: BTreeSet<Span>, |
| } |
| |
| struct TypoSuggestion { |
| candidate: Symbol, |
| |
| /// The kind of the binding ("crate", "module", etc.) |
| kind: &'static str, |
| |
| /// An appropriate article to refer to the binding ("a", "an", etc.) |
| article: &'static str, |
| } |
| |
| 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) |
| } |
| } |
| |
| /// A vector of spans and replacements, a message and applicability. |
| type Suggestion = (Vec<(Span, String)>, String, Applicability); |
| |
| 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, &'a 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, |
| } |
| |
| /// Combines an error with provided span and emits it. |
| /// |
| /// This takes the error provided, combines it with the span and any additional spans inside the |
| /// error and emits it. |
| fn resolve_error<'sess, 'a>(resolver: &'sess Resolver<'_>, |
| span: Span, |
| resolution_error: ResolutionError<'a>) { |
| resolve_struct_error(resolver, span, resolution_error).emit(); |
| } |
| |
| fn resolve_struct_error<'sess, 'a>(resolver: &'sess Resolver<'_>, |
| span: Span, |
| resolution_error: ResolutionError<'a>) |
| -> DiagnosticBuilder<'sess> { |
| match resolution_error { |
| ResolutionError::GenericParamsFromOuterFunction(outer_res) => { |
| let mut err = struct_span_err!(resolver.session, |
| span, |
| E0401, |
| "can't use generic parameters from outer function", |
| ); |
| err.span_label(span, format!("use of generic parameter from outer function")); |
| |
| let cm = resolver.session.source_map(); |
| match outer_res { |
| Res::SelfTy(maybe_trait_defid, maybe_impl_defid) => { |
| if let Some(impl_span) = maybe_impl_defid.and_then(|def_id| { |
| resolver.definitions.opt_span(def_id) |
| }) { |
| err.span_label( |
| reduce_impl_span_to_impl_keyword(cm, impl_span), |
| "`Self` type implicitly declared here, by this `impl`", |
| ); |
| } |
| match (maybe_trait_defid, maybe_impl_defid) { |
| (Some(_), None) => { |
| err.span_label(span, "can't use `Self` here"); |
| } |
| (_, Some(_)) => { |
| err.span_label(span, "use a type here instead"); |
| } |
| (None, None) => bug!("`impl` without trait nor type?"), |
| } |
| return err; |
| }, |
| Res::Def(DefKind::TyParam, def_id) => { |
| if let Some(span) = resolver.definitions.opt_span(def_id) { |
| err.span_label(span, "type parameter from outer function"); |
| } |
| } |
| Res::Def(DefKind::ConstParam, def_id) => { |
| if let Some(span) = resolver.definitions.opt_span(def_id) { |
| err.span_label(span, "const parameter from outer function"); |
| } |
| } |
| _ => { |
| bug!("GenericParamsFromOuterFunction should only be used with Res::SelfTy, \ |
| DefKind::TyParam"); |
| } |
| } |
| |
| // Try to retrieve the span of the function signature and generate a new message with |
| // a local type or const parameter. |
| let sugg_msg = &format!("try using a local generic parameter instead"); |
| if let Some((sugg_span, new_snippet)) = cm.generate_local_type_param_snippet(span) { |
| // Suggest the modification to the user |
| err.span_suggestion( |
| sugg_span, |
| sugg_msg, |
| new_snippet, |
| Applicability::MachineApplicable, |
| ); |
| } else if let Some(sp) = cm.generate_fn_name_span(span) { |
| err.span_label(sp, |
| format!("try adding a local generic parameter in this method instead")); |
| } else { |
| err.help(&format!("try using a local generic parameter instead")); |
| } |
| |
| err |
| } |
| ResolutionError::NameAlreadyUsedInParameterList(name, first_use_span) => { |
| let mut err = struct_span_err!(resolver.session, |
| span, |
| E0403, |
| "the name `{}` is already used for a generic \ |
| parameter in this list of generic parameters", |
| name); |
| err.span_label(span, "already used"); |
| err.span_label(first_use_span.clone(), format!("first use of `{}`", name)); |
| err |
| } |
| ResolutionError::MethodNotMemberOfTrait(method, trait_) => { |
| let mut err = struct_span_err!(resolver.session, |
| span, |
| E0407, |
| "method `{}` is not a member of trait `{}`", |
| method, |
| trait_); |
| err.span_label(span, format!("not a member of trait `{}`", trait_)); |
| err |
| } |
| ResolutionError::TypeNotMemberOfTrait(type_, trait_) => { |
| let mut err = struct_span_err!(resolver.session, |
| span, |
| E0437, |
| "type `{}` is not a member of trait `{}`", |
| type_, |
| trait_); |
| err.span_label(span, format!("not a member of trait `{}`", trait_)); |
| err |
| } |
| ResolutionError::ConstNotMemberOfTrait(const_, trait_) => { |
| let mut err = struct_span_err!(resolver.session, |
| span, |
| E0438, |
| "const `{}` is not a member of trait `{}`", |
| const_, |
| trait_); |
| err.span_label(span, format!("not a member of trait `{}`", trait_)); |
| err |
| } |
| ResolutionError::VariableNotBoundInPattern(binding_error) => { |
| let target_sp = binding_error.target.iter().cloned().collect::<Vec<_>>(); |
| let msp = MultiSpan::from_spans(target_sp.clone()); |
| let msg = format!("variable `{}` is not bound in all patterns", binding_error.name); |
| let mut err = resolver.session.struct_span_err_with_code( |
| msp, |
| &msg, |
| DiagnosticId::Error("E0408".into()), |
| ); |
| for sp in target_sp { |
| err.span_label(sp, format!("pattern doesn't bind `{}`", binding_error.name)); |
| } |
| let origin_sp = binding_error.origin.iter().cloned(); |
| for sp in origin_sp { |
| err.span_label(sp, "variable not in all patterns"); |
| } |
| err |
| } |
| ResolutionError::VariableBoundWithDifferentMode(variable_name, |
| first_binding_span) => { |
| let mut err = struct_span_err!(resolver.session, |
| span, |
| E0409, |
| "variable `{}` is bound in inconsistent \ |
| ways within the same match arm", |
| variable_name); |
| err.span_label(span, "bound in different ways"); |
| err.span_label(first_binding_span, "first binding"); |
| err |
| } |
| ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => { |
| let mut err = struct_span_err!(resolver.session, |
| span, |
| E0415, |
| "identifier `{}` is bound more than once in this parameter list", |
| identifier); |
| err.span_label(span, "used as parameter more than once"); |
| err |
| } |
| ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => { |
| let mut err = struct_span_err!(resolver.session, |
| span, |
| E0416, |
| "identifier `{}` is bound more than once in the same pattern", |
| identifier); |
| err.span_label(span, "used in a pattern more than once"); |
| err |
| } |
| ResolutionError::UndeclaredLabel(name, lev_candidate) => { |
| let mut err = struct_span_err!(resolver.session, |
| span, |
| E0426, |
| "use of undeclared label `{}`", |
| name); |
| if let Some(lev_candidate) = lev_candidate { |
| err.span_suggestion( |
| span, |
| "a label with a similar name exists in this scope", |
| lev_candidate.to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| } else { |
| err.span_label(span, format!("undeclared label `{}`", name)); |
| } |
| err |
| } |
| ResolutionError::SelfImportsOnlyAllowedWithin => { |
| struct_span_err!(resolver.session, |
| span, |
| E0429, |
| "{}", |
| "`self` imports are only allowed within a { } list") |
| } |
| ResolutionError::SelfImportCanOnlyAppearOnceInTheList => { |
| let mut err = struct_span_err!(resolver.session, span, E0430, |
| "`self` import can only appear once in an import list"); |
| err.span_label(span, "can only appear once in an import list"); |
| err |
| } |
| ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => { |
| let mut err = struct_span_err!(resolver.session, span, E0431, |
| "`self` import can only appear in an import list with \ |
| a non-empty prefix"); |
| err.span_label(span, "can only appear in an import list with a non-empty prefix"); |
| err |
| } |
| ResolutionError::FailedToResolve { label, suggestion } => { |
| let mut err = struct_span_err!(resolver.session, span, E0433, |
| "failed to resolve: {}", &label); |
| err.span_label(span, label); |
| |
| if let Some((suggestions, msg, applicability)) = suggestion { |
| err.multipart_suggestion(&msg, suggestions, applicability); |
| } |
| |
| err |
| } |
| ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => { |
| let mut err = struct_span_err!(resolver.session, |
| span, |
| E0434, |
| "{}", |
| "can't capture dynamic environment in a fn item"); |
| err.help("use the `|| { ... }` closure form instead"); |
| err |
| } |
| ResolutionError::AttemptToUseNonConstantValueInConstant => { |
| let mut err = struct_span_err!(resolver.session, span, E0435, |
| "attempt to use a non-constant value in a constant"); |
| err.span_label(span, "non-constant value"); |
| err |
| } |
| ResolutionError::BindingShadowsSomethingUnacceptable(what_binding, name, binding) => { |
| let shadows_what = binding.descr(); |
| let mut err = struct_span_err!(resolver.session, span, E0530, "{}s cannot shadow {}s", |
| what_binding, shadows_what); |
| err.span_label(span, format!("cannot be named the same as {} {}", |
| binding.article(), shadows_what)); |
| let participle = if binding.is_import() { "imported" } else { "defined" }; |
| let msg = format!("the {} `{}` is {} here", shadows_what, name, participle); |
| err.span_label(binding.span, msg); |
| err |
| } |
| ResolutionError::ForwardDeclaredTyParam => { |
| let mut err = struct_span_err!(resolver.session, span, E0128, |
| "type parameters with a default cannot use \ |
| forward declared identifiers"); |
| err.span_label( |
| span, "defaulted type parameters cannot be forward declared".to_string()); |
| err |
| } |
| ResolutionError::ConstParamDependentOnTypeParam => { |
| let mut err = struct_span_err!( |
| resolver.session, |
| span, |
| E0671, |
| "const parameters cannot depend on type parameters" |
| ); |
| err.span_label(span, format!("const parameter depends on type parameter")); |
| err |
| } |
| } |
| } |
| |
| /// Adjust the impl span so that just the `impl` keyword is taken by removing |
| /// everything after `<` (`"impl<T> Iterator for A<T> {}" -> "impl"`) and |
| /// everything after the first whitespace (`"impl Iterator for A" -> "impl"`). |
| /// |
| /// *Attention*: the method used is very fragile since it essentially duplicates the work of the |
| /// parser. If you need to use this function or something similar, please consider updating the |
| /// `source_map` functions and this function to something more robust. |
| fn reduce_impl_span_to_impl_keyword(cm: &SourceMap, impl_span: Span) -> Span { |
| let impl_span = cm.span_until_char(impl_span, '<'); |
| let impl_span = cm.span_until_whitespace(impl_span); |
| impl_span |
| } |
| |
| #[derive(Copy, Clone, Debug)] |
| struct BindingInfo { |
| span: Span, |
| binding_mode: BindingMode, |
| } |
| |
| /// Map from the name in a pattern to its binding mode. |
| type BindingMap = FxHashMap<Ident, BindingInfo>; |
| |
| #[derive(Copy, Clone, PartialEq, Eq, Debug)] |
| enum PatternSource { |
| Match, |
| Let, |
| For, |
| FnParam, |
| } |
| |
| impl PatternSource { |
| fn descr(self) -> &'static str { |
| match self { |
| PatternSource::Match => "match binding", |
| PatternSource::Let => "let binding", |
| PatternSource::For => "for binding", |
| PatternSource::FnParam => "function parameter", |
| } |
| } |
| } |
| |
| #[derive(Copy, Clone, PartialEq, Eq, Debug)] |
| enum AliasPossibility { |
| No, |
| Maybe, |
| } |
| |
| #[derive(Copy, Clone, Debug)] |
| enum PathSource<'a> { |
| // Type paths `Path`. |
| Type, |
| // Trait paths in bounds or impls. |
| Trait(AliasPossibility), |
| // Expression paths `path`, with optional parent context. |
| Expr(Option<&'a Expr>), |
| // Paths in path patterns `Path`. |
| Pat, |
| // Paths in struct expressions and patterns `Path { .. }`. |
| Struct, |
| // Paths in tuple struct patterns `Path(..)`. |
| TupleStruct, |
| // `m::A::B` in `<T as m::A>::B::C`. |
| TraitItem(Namespace), |
| // Path in `pub(path)` |
| Visibility, |
| } |
| |
| impl<'a> PathSource<'a> { |
| fn namespace(self) -> Namespace { |
| match self { |
| PathSource::Type | PathSource::Trait(_) | PathSource::Struct | |
| PathSource::Visibility => TypeNS, |
| PathSource::Expr(..) | PathSource::Pat | PathSource::TupleStruct => ValueNS, |
| PathSource::TraitItem(ns) => ns, |
| } |
| } |
| |
| fn global_by_default(self) -> bool { |
| match self { |
| PathSource::Visibility => true, |
| PathSource::Type | PathSource::Expr(..) | PathSource::Pat | |
| PathSource::Struct | PathSource::TupleStruct | |
| PathSource::Trait(_) | PathSource::TraitItem(..) => false, |
| } |
| } |
| |
| fn defer_to_typeck(self) -> bool { |
| match self { |
| PathSource::Type | PathSource::Expr(..) | PathSource::Pat | |
| PathSource::Struct | PathSource::TupleStruct => true, |
| PathSource::Trait(_) | PathSource::TraitItem(..) | |
| PathSource::Visibility => false, |
| } |
| } |
| |
| fn descr_expected(self) -> &'static str { |
| match self { |
| PathSource::Type => "type", |
| PathSource::Trait(_) => "trait", |
| PathSource::Pat => "unit struct/variant or constant", |
| PathSource::Struct => "struct, variant or union type", |
| PathSource::TupleStruct => "tuple struct/variant", |
| PathSource::Visibility => "module", |
| PathSource::TraitItem(ns) => match ns { |
| TypeNS => "associated type", |
| ValueNS => "method or associated constant", |
| MacroNS => bug!("associated macro"), |
| }, |
| PathSource::Expr(parent) => match parent.map(|p| &p.node) { |
| // "function" here means "anything callable" rather than `DefKind::Fn`, |
| // this is not precise but usually more helpful than just "value". |
| Some(&ExprKind::Call(..)) => "function", |
| _ => "value", |
| }, |
| } |
| } |
| |
| fn is_expected(self, res: Res) -> bool { |
| match self { |
| PathSource::Type => match res { |
| Res::Def(DefKind::Struct, _) |
| | Res::Def(DefKind::Union, _) |
| | Res::Def(DefKind::Enum, _) |
| | Res::Def(DefKind::Trait, _) |
| | Res::Def(DefKind::TraitAlias, _) |
| | Res::Def(DefKind::TyAlias, _) |
| | Res::Def(DefKind::AssocTy, _) |
| | Res::PrimTy(..) |
| | Res::Def(DefKind::TyParam, _) |
| | Res::SelfTy(..) |
| | Res::Def(DefKind::Existential, _) |
| | Res::Def(DefKind::ForeignTy, _) => true, |
| _ => false, |
| }, |
| PathSource::Trait(AliasPossibility::No) => match res { |
| Res::Def(DefKind::Trait, _) => true, |
| _ => false, |
| }, |
| PathSource::Trait(AliasPossibility::Maybe) => match res { |
| Res::Def(DefKind::Trait, _) => true, |
| Res::Def(DefKind::TraitAlias, _) => true, |
| _ => false, |
| }, |
| PathSource::Expr(..) => match res { |
| Res::Def(DefKind::Ctor(_, CtorKind::Const), _) |
| | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _) |
| | Res::Def(DefKind::Const, _) |
| | Res::Def(DefKind::Static, _) |
| | Res::Local(..) |
| | Res::Def(DefKind::Fn, _) |
| | Res::Def(DefKind::Method, _) |
| | Res::Def(DefKind::AssocConst, _) |
| | Res::SelfCtor(..) |
| | Res::Def(DefKind::ConstParam, _) => true, |
| _ => false, |
| }, |
| PathSource::Pat => match res { |
| Res::Def(DefKind::Ctor(_, CtorKind::Const), _) | |
| Res::Def(DefKind::Const, _) | Res::Def(DefKind::AssocConst, _) | |
| Res::SelfCtor(..) => true, |
| _ => false, |
| }, |
| PathSource::TupleStruct => match res { |
| Res::Def(DefKind::Ctor(_, CtorKind::Fn), _) | Res::SelfCtor(..) => true, |
| _ => false, |
| }, |
| PathSource::Struct => match res { |
| Res::Def(DefKind::Struct, _) |
| | Res::Def(DefKind::Union, _) |
| | Res::Def(DefKind::Variant, _) |
| | Res::Def(DefKind::TyAlias, _) |
| | Res::Def(DefKind::AssocTy, _) |
| | Res::SelfTy(..) => true, |
| _ => false, |
| }, |
| PathSource::TraitItem(ns) => match res { |
| Res::Def(DefKind::AssocConst, _) |
| | Res::Def(DefKind::Method, _) if ns == ValueNS => true, |
| Res::Def(DefKind::AssocTy, _) if ns == TypeNS => true, |
| _ => false, |
| }, |
| PathSource::Visibility => match res { |
| Res::Def(DefKind::Mod, _) => true, |
| _ => false, |
| }, |
| } |
| } |
| |
| fn error_code(self, has_unexpected_resolution: bool) -> &'static str { |
| __diagnostic_used!(E0404); |
| __diagnostic_used!(E0405); |
| __diagnostic_used!(E0412); |
| __diagnostic_used!(E0422); |
| __diagnostic_used!(E0423); |
| __diagnostic_used!(E0425); |
| __diagnostic_used!(E0531); |
| __diagnostic_used!(E0532); |
| __diagnostic_used!(E0573); |
| __diagnostic_used!(E0574); |
| __diagnostic_used!(E0575); |
| __diagnostic_used!(E0576); |
| __diagnostic_used!(E0577); |
| __diagnostic_used!(E0578); |
| match (self, has_unexpected_resolution) { |
| (PathSource::Trait(_), true) => "E0404", |
| (PathSource::Trait(_), false) => "E0405", |
| (PathSource::Type, true) => "E0573", |
| (PathSource::Type, false) => "E0412", |
| (PathSource::Struct, true) => "E0574", |
| (PathSource::Struct, false) => "E0422", |
| (PathSource::Expr(..), true) => "E0423", |
| (PathSource::Expr(..), false) => "E0425", |
| (PathSource::Pat, true) | (PathSource::TupleStruct, true) => "E0532", |
| (PathSource::Pat, false) | (PathSource::TupleStruct, false) => "E0531", |
| (PathSource::TraitItem(..), true) => "E0575", |
| (PathSource::TraitItem(..), false) => "E0576", |
| (PathSource::Visibility, true) => "E0577", |
| (PathSource::Visibility, false) => "E0578", |
| } |
| } |
| } |
| |
| // 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.ctxt().outer_expn_info().is_none() { |
| 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.ctxt().outer_expn_info().is_none() { |
| // 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()); |
| } |
| } |
| } |
| } |
| }, |
| } |
| } |
| } |
| } |
| |
| /// Walks the whole crate in DFS order, visiting each item, resolving names as it goes. |
| impl<'a, 'tcx> Visitor<'tcx> for Resolver<'a> { |
| fn visit_item(&mut self, item: &'tcx Item) { |
| self.resolve_item(item); |
| } |
| fn visit_arm(&mut self, arm: &'tcx Arm) { |
| self.resolve_arm(arm); |
| } |
| fn visit_block(&mut self, block: &'tcx Block) { |
| self.resolve_block(block); |
| } |
| fn visit_anon_const(&mut self, constant: &'tcx ast::AnonConst) { |
| debug!("visit_anon_const {:?}", constant); |
| self.with_constant_rib(|this| { |
| visit::walk_anon_const(this, constant); |
| }); |
| } |
| fn visit_expr(&mut self, expr: &'tcx Expr) { |
| self.resolve_expr(expr, None); |
| } |
| fn visit_local(&mut self, local: &'tcx Local) { |
| self.resolve_local(local); |
| } |
| fn visit_ty(&mut self, ty: &'tcx Ty) { |
| match ty.node { |
| TyKind::Path(ref qself, ref path) => { |
| self.smart_resolve_path(ty.id, qself.as_ref(), path, PathSource::Type); |
| } |
| TyKind::ImplicitSelf => { |
| let self_ty = Ident::with_empty_ctxt(kw::SelfUpper); |
| let res = self.resolve_ident_in_lexical_scope(self_ty, TypeNS, Some(ty.id), ty.span) |
| .map_or(Res::Err, |d| d.res()); |
| self.record_partial_res(ty.id, PartialRes::new(res)); |
| } |
| _ => (), |
| } |
| visit::walk_ty(self, ty); |
| } |
| fn visit_poly_trait_ref(&mut self, |
| tref: &'tcx ast::PolyTraitRef, |
| m: &'tcx ast::TraitBoundModifier) { |
| self.smart_resolve_path(tref.trait_ref.ref_id, None, |
| &tref.trait_ref.path, PathSource::Trait(AliasPossibility::Maybe)); |
| visit::walk_poly_trait_ref(self, tref, m); |
| } |
| fn visit_foreign_item(&mut self, foreign_item: &'tcx ForeignItem) { |
| let generic_params = match foreign_item.node { |
| ForeignItemKind::Fn(_, ref generics) => { |
| HasGenericParams(generics, ItemRibKind) |
| } |
| ForeignItemKind::Static(..) => NoGenericParams, |
| ForeignItemKind::Ty => NoGenericParams, |
| ForeignItemKind::Macro(..) => NoGenericParams, |
| }; |
| self.with_generic_param_rib(generic_params, |this| { |
| visit::walk_foreign_item(this, foreign_item); |
| }); |
| } |
| fn visit_fn(&mut self, |
| function_kind: FnKind<'tcx>, |
| declaration: &'tcx FnDecl, |
| _: Span, |
| _: NodeId) |
| { |
| debug!("(resolving function) entering function"); |
| let rib_kind = match function_kind { |
| FnKind::ItemFn(..) => FnItemRibKind, |
| FnKind::Method(..) => AssocItemRibKind, |
| FnKind::Closure(_) => NormalRibKind, |
| }; |
| |
| // Create a value rib for the function. |
| self.ribs[ValueNS].push(Rib::new(rib_kind)); |
| |
| // Create a label rib for the function. |
| self.label_ribs.push(Rib::new(rib_kind)); |
| |
| // Add each argument to the rib. |
| let mut bindings_list = FxHashMap::default(); |
| for argument in &declaration.inputs { |
| self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list); |
| |
| self.visit_ty(&argument.ty); |
| |
| debug!("(resolving function) recorded argument"); |
| } |
| visit::walk_fn_ret_ty(self, &declaration.output); |
| |
| // Resolve the function body, potentially inside the body of an async closure |
| match function_kind { |
| FnKind::ItemFn(.., body) | |
| FnKind::Method(.., body) => { |
| self.visit_block(body); |
| } |
| FnKind::Closure(body) => { |
| self.visit_expr(body); |
| } |
| }; |
| |
| debug!("(resolving function) leaving function"); |
| |
| self.label_ribs.pop(); |
| self.ribs[ValueNS].pop(); |
| } |
| |
| fn visit_generics(&mut self, generics: &'tcx Generics) { |
| // For type parameter defaults, we have to ban access |
| // to following type parameters, as the InternalSubsts can only |
| // provide previous type parameters as they're built. We |
| // put all the parameters on the ban list and then remove |
| // them one by one as they are processed and become available. |
| let mut default_ban_rib = Rib::new(ForwardTyParamBanRibKind); |
| let mut found_default = false; |
| default_ban_rib.bindings.extend(generics.params.iter() |
| .filter_map(|param| match param.kind { |
| GenericParamKind::Const { .. } | |
| GenericParamKind::Lifetime { .. } => None, |
| GenericParamKind::Type { ref default, .. } => { |
| found_default |= default.is_some(); |
| if found_default { |
| Some((Ident::with_empty_ctxt(param.ident.name), Res::Err)) |
| } else { |
| None |
| } |
| } |
| })); |
| |
| // We also ban access to type parameters for use as the types of const parameters. |
| let mut const_ty_param_ban_rib = Rib::new(TyParamAsConstParamTy); |
| const_ty_param_ban_rib.bindings.extend(generics.params.iter() |
| .filter(|param| { |
| if let GenericParamKind::Type { .. } = param.kind { |
| true |
| } else { |
| false |
| } |
| }) |
| .map(|param| (Ident::with_empty_ctxt(param.ident.name), Res::Err))); |
| |
| for param in &generics.params { |
| match param.kind { |
| GenericParamKind::Lifetime { .. } => self.visit_generic_param(param), |
| GenericParamKind::Type { ref default, .. } => { |
| for bound in ¶m.bounds { |
| self.visit_param_bound(bound); |
| } |
| |
| if let Some(ref ty) = default { |
| self.ribs[TypeNS].push(default_ban_rib); |
| self.visit_ty(ty); |
| default_ban_rib = self.ribs[TypeNS].pop().unwrap(); |
| } |
| |
| // Allow all following defaults to refer to this type parameter. |
| default_ban_rib.bindings.remove(&Ident::with_empty_ctxt(param.ident.name)); |
| } |
| GenericParamKind::Const { ref ty } => { |
| self.ribs[TypeNS].push(const_ty_param_ban_rib); |
| |
| for bound in ¶m.bounds { |
| self.visit_param_bound(bound); |
| } |
| |
| self.visit_ty(ty); |
| |
| const_ty_param_ban_rib = self.ribs[TypeNS].pop().unwrap(); |
| } |
| } |
| } |
| for p in &generics.where_clause.predicates { |
| self.visit_where_predicate(p); |
| } |
| } |
| } |
| |
| #[derive(Copy, Clone)] |
| enum GenericParameters<'a, 'b> { |
| NoGenericParams, |
| HasGenericParams(// Type parameters. |
| &'b Generics, |
| |
| // The kind of the rib used for type parameters. |
| RibKind<'a>), |
| } |
| |
| /// The rib kind restricts certain accesses, |
| /// e.g. to a `Res::Local` of an outer item. |
| #[derive(Copy, Clone, Debug)] |
| enum RibKind<'a> { |
| /// No restriction needs to be applied. |
| NormalRibKind, |
| |
| /// We passed through an impl or trait and are now in one of its |
| /// methods or associated types. Allow references to ty params that impl or trait |
| /// binds. Disallow any other upvars (including other ty params that are |
| /// upvars). |
| AssocItemRibKind, |
| |
| /// We passed through a function definition. Disallow upvars. |
| /// Permit only those const parameters that are specified in the function's generics. |
| FnItemRibKind, |
| |
| /// We passed through an item scope. Disallow upvars. |
| ItemRibKind, |
| |
| /// We're in a constant item. Can't refer to dynamic stuff. |
| ConstantItemRibKind, |
| |
| /// We passed through a module. |
| ModuleRibKind(Module<'a>), |
| |
| /// We passed through a `macro_rules!` statement |
| MacroDefinition(DefId), |
| |
| /// All bindings in this rib are type parameters that can't be used |
| /// from the default of a type parameter because they're not declared |
| /// before said type parameter. Also see the `visit_generics` override. |
| ForwardTyParamBanRibKind, |
| |
| /// We forbid the use of type parameters as the types of const parameters. |
| TyParamAsConstParamTy, |
| } |
| |
| /// A single local scope. |
| /// |
| /// A rib represents a scope names can live in. Note that these appear in many places, not just |
| /// around braces. At any place where the list of accessible names (of the given namespace) |
| /// changes or a new restrictions on the name accessibility are introduced, a new rib is put onto a |
| /// stack. This may be, for example, a `let` statement (because it introduces variables), a macro, |
| /// etc. |
| /// |
| /// Different [rib kinds](enum.RibKind) are transparent for different names. |
| /// |
| /// The resolution keeps a separate stack of ribs as it traverses the AST for each namespace. When |
| /// resolving, the name is looked up from inside out. |
| #[derive(Debug)] |
| struct Rib<'a, R = Res> { |
| bindings: FxHashMap<Ident, R>, |
| kind: RibKind<'a>, |
| } |
| |
| impl<'a, R> Rib<'a, R> { |
| fn new(kind: RibKind<'a>) -> Rib<'a, R> { |
| Rib { |
| bindings: Default::default(), |
| kind, |
| } |
| } |
| } |
| |
| /// 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. |
| 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), |
| } |
| } |
| } |
| |
| /// 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, |
| |
| resolutions: RefCell<FxHashMap<(Ident, Namespace), &'a RefCell<NameResolution<'a>>>>, |
| single_segment_macro_resolutions: RefCell<Vec<(Ident, MacroKind, ParentScope<'a>, |
| Option<&'a NameBinding<'a>>)>>, |
| multi_segment_macro_resolutions: RefCell<Vec<(Vec<Segment>, Span, MacroKind, ParentScope<'a>, |
| Option<Res>)>>, |
| builtin_attrs: RefCell<Vec<(Ident, ParentScope<'a>)>>, |
| |
| // Macro invocations that can expand into items in this module. |
| unresolved_invocations: RefCell<FxHashSet<Mark>>, |
| |
| 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>)]>>>, |
| |
| // Whether this module is populated. If not populated, any attempt to |
| // access the children must be preceded with a |
| // `populate_module_if_necessary` call. |
| populated: Cell<bool>, |
| |
| /// Span of the module itself. Used for error reporting. |
| span: Span, |
| |
| expansion: Mark, |
| } |
| |
| type Module<'a> = &'a ModuleData<'a>; |
| |
| impl<'a> ModuleData<'a> { |
| fn new(parent: Option<Module<'a>>, |
| kind: ModuleKind, |
| normal_ancestor_id: DefId, |
| expansion: Mark, |
| span: Span) -> Self { |
| ModuleData { |
| parent, |
| kind, |
| normal_ancestor_id, |
| resolutions: Default::default(), |
| single_segment_macro_resolutions: RefCell::new(Vec::new()), |
| multi_segment_macro_resolutions: RefCell::new(Vec::new()), |
| builtin_attrs: RefCell::new(Vec::new()), |
| unresolved_invocations: Default::default(), |
| no_implicit_prelude: false, |
| glob_importers: RefCell::new(Vec::new()), |
| globs: RefCell::new(Vec::new()), |
| traits: RefCell::new(None), |
| populated: Cell::new(normal_ancestor_id.is_local()), |
| span, |
| expansion, |
| } |
| } |
| |
| fn for_each_child<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) { |
| for (&(ident, ns), name_resolution) in self.resolutions.borrow().iter() { |
| name_resolution.borrow().binding.map(|binding| f(ident, ns, binding)); |
| } |
| } |
| |
| fn for_each_child_stable<F: FnMut(Ident, Namespace, &'a NameBinding<'a>)>(&self, mut f: F) { |
| let resolutions = self.resolutions.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(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_kind(&self) -> Option<DefKind> { |
| match self.kind { |
| ModuleKind::Def(kind, ..) => Some(kind), |
| _ => 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> { |
| if self.is_trait() { self.parent.unwrap() } else { 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: Mark, |
| 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> { |
| match self.res() { |
| Res::Def(DefKind::Macro(kind), _) => Some(kind), |
| Res::NonMacroAttr(..) => Some(MacroKind::Attr), |
| _ => None, |
| } |
| } |
| |
| fn descr(&self) -> &'static str { |
| if self.is_extern_crate() { "extern crate" } else { self.res().descr() } |
| } |
| |
| fn article(&self) -> &'static str { |
| if self.is_extern_crate() { "an" } else { self.res().article() } |
| } |
| |
| // 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: Mark, 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, |
| |
| 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>>, |
| |
| /// The module that represents the current item scope. |
| current_module: Module<'a>, |
| |
| /// The current set of local scopes for types and values. |
| /// FIXME #4948: Reuse ribs to avoid allocation. |
| ribs: PerNS<Vec<Rib<'a>>>, |
| |
| /// The current set of local scopes, for labels. |
| label_ribs: Vec<Rib<'a, NodeId>>, |
| |
| /// The trait that the current context can refer to. |
| current_trait_ref: Option<(Module<'a>, TraitRef)>, |
| |
| /// The current self type if inside an impl (used for better errors). |
| current_self_type: Option<Ty>, |
| |
| /// The current self item if inside an ADT (used for better errors). |
| current_self_item: Option<NodeId>, |
| |
| /// 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>>, |
| 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)>, |
| |
| /// A list of labels as of yet unused. Labels will be removed from this map when |
| /// they are used (in a `break` or `continue` statement) |
| pub unused_labels: FxHashMap<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, &'a NameBinding<'a>>, |
| macro_use_prelude: FxHashMap<Name, &'a NameBinding<'a>>, |
| pub all_macros: FxHashMap<Name, Res>, |
| macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>, |
| non_macro_attrs: [Lrc<SyntaxExtension>; 2], |
| macro_defs: FxHashMap<Mark, DefId>, |
| local_macro_def_scopes: FxHashMap<NodeId, Module<'a>>, |
| |
| /// List of crate local macros that we need to warn about as being unused. |
| /// Right now this only includes macro_rules! macros, and macros 2.0. |
| unused_macros: FxHashSet<DefId>, |
| |
| /// Maps the `Mark` of an expansion to its containing module or block. |
| invocations: FxHashMap<Mark, &'a InvocationData<'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)>, |
| |
| /// Only used for better errors on `fn(): fn()`. |
| current_type_ascription: Vec<Span>, |
| |
| injected_crate: Option<Module<'a>>, |
| } |
| |
| /// 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>>>, |
| invocation_data: arena::TypedArena<InvocationData<'a>>, |
| legacy_bindings: arena::TypedArena<LegacyBinding<'a>>, |
| } |
| |
| 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_invocation_data(&'a self, expansion_data: InvocationData<'a>) |
| -> &'a InvocationData<'a> { |
| self.invocation_data.alloc(expansion_data) |
| } |
| fn alloc_legacy_binding(&'a self, binding: LegacyBinding<'a>) -> &'a LegacyBinding<'a> { |
| self.legacy_bindings.alloc(binding) |
| } |
| } |
| |
| 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_hir_path( |
| &mut self, |
| path: &ast::Path, |
| is_value: bool, |
| ) -> hir::Path { |
| self.resolve_hir_path_cb(path, is_value, |
| |resolver, span, error| resolve_error(resolver, span, error)) |
| } |
| |
| fn resolve_str_path( |
| &mut self, |
| span: Span, |
| crate_root: Option<Symbol>, |
| components: &[Symbol], |
| is_value: bool |
| ) -> hir::Path { |
| let root = if crate_root.is_some() { |
| kw::PathRoot |
| } else { |
| kw::Crate |
| }; |
| let segments = iter::once(Ident::with_empty_ctxt(root)) |
| .chain( |
| crate_root.into_iter() |
| .chain(components.iter().cloned()) |
| .map(Ident::with_empty_ctxt) |
| ).map(|i| self.new_ast_path_segment(i)).collect::<Vec<_>>(); |
| |
| let path = ast::Path { |
| span, |
| segments, |
| }; |
| |
| self.resolve_hir_path(&path, is_value) |
| } |
| |
| 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 |
| } |
| } |
| |
| impl<'a> Resolver<'a> { |
| /// 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. |
| pub fn resolve_str_path_error(&mut self, span: Span, path_str: &str, is_value: bool) |
| -> Result<hir::Path, ()> { |
| let mut errored = false; |
| |
| let path = if path_str.starts_with("::") { |
| ast::Path { |
| span, |
| segments: iter::once(Ident::with_empty_ctxt(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 path = self.resolve_hir_path_cb(&path, is_value, |_, _, _| errored = true); |
| if errored || path.res == def::Res::Err { |
| Err(()) |
| } else { |
| Ok(path) |
| } |
| } |
| |
| /// Like `resolve_hir_path`, but takes a callback in case there was an error. |
| fn resolve_hir_path_cb<F>( |
| &mut self, |
| path: &ast::Path, |
| is_value: bool, |
| error_callback: F, |
| ) -> hir::Path |
| where F: for<'c, 'b> FnOnce(&'c mut Resolver<'_>, Span, ResolutionError<'b>) |
| { |
| let namespace = if is_value { ValueNS } else { TypeNS }; |
| let span = path.span; |
| let segments = &path.segments; |
| let path = Segment::from_path(&path); |
| // FIXME(Manishearth): intra-doc links won't get warned of epoch changes. |
| let res = match self.resolve_path_without_parent_scope(&path, Some(namespace), true, |
| span, CrateLint::No) { |
| PathResult::Module(ModuleOrUniformRoot::Module(module)) => |
| module.res().unwrap(), |
| PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 => |
| path_res.base_res(), |
| PathResult::NonModule(..) => { |
| error_callback(self, span, ResolutionError::FailedToResolve { |
| label: String::from("type-relative paths are not supported in this context"), |
| suggestion: None, |
| }); |
| Res::Err |
| } |
| PathResult::Module(..) | PathResult::Indeterminate => unreachable!(), |
| PathResult::Failed { span, label, suggestion, .. } => { |
| error_callback(self, span, ResolutionError::FailedToResolve { |
| label, |
| suggestion, |
| }); |
| Res::Err |
| } |
| }; |
| |
| let segments: Vec<_> = segments.iter().map(|seg| { |
| let mut hir_seg = hir::PathSegment::from_ident(seg.ident); |
| hir_seg.res = Some(self.partial_res_map.get(&seg.id).map_or(def::Res::Err, |p| { |
| p.base_res().map_id(|_| panic!("unexpected node_id")) |
| })); |
| hir_seg |
| }).collect(); |
| hir::Path { |
| span, |
| res: res.map_id(|_| panic!("unexpected node_id")), |
| segments: segments.into(), |
| } |
| } |
| |
| 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 |
| } |
| } |
| |
| 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, Mark::root(), krate.span) |
| }); |
| let mut module_map = FxHashMap::default(); |
| module_map.insert(DefId::local(CRATE_DEF_INDEX), graph_root); |
| |
| let mut definitions = Definitions::default(); |
| DefCollector::new(&mut definitions, Mark::root()) |
| .collect_root(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_empty_ctxt(sym::core), Default::default()); |
| if !attr::contains_name(&krate.attrs, sym::no_std) { |
| extern_prelude.insert(Ident::with_empty_ctxt(sym::std), Default::default()); |
| if session.rust_2018() { |
| extern_prelude.insert(Ident::with_empty_ctxt(sym::meta), Default::default()); |
| } |
| } |
| } |
| |
| let mut invocations = FxHashMap::default(); |
| invocations.insert(Mark::root(), |
| arenas.alloc_invocation_data(InvocationData::root(graph_root))); |
| |
| let mut macro_defs = FxHashMap::default(); |
| macro_defs.insert(Mark::root(), root_def_id); |
| |
| let non_macro_attr = |mark_used| Lrc::new(SyntaxExtension::default( |
| SyntaxExtensionKind::NonMacroAttr { 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(), |
| |
| current_module: graph_root, |
| ribs: PerNS { |
| value_ns: vec![Rib::new(ModuleRibKind(graph_root))], |
| type_ns: vec![Rib::new(ModuleRibKind(graph_root))], |
| macro_ns: vec![Rib::new(ModuleRibKind(graph_root))], |
| }, |
| label_ribs: Vec::new(), |
| |
| current_trait_ref: None, |
| current_self_type: None, |
| current_self_item: None, |
| 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(), |
| module_map, |
| block_map: Default::default(), |
| extern_module_map: FxHashMap::default(), |
| binding_parent_modules: FxHashMap::default(), |
| |
| glob_map: Default::default(), |
| |
| used_imports: FxHashSet::default(), |
| maybe_unused_trait_imports: Default::default(), |
| maybe_unused_extern_crates: Vec::new(), |
| |
| unused_labels: FxHashMap::default(), |
| |
| 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: Mark::root(), |
| span: DUMMY_SP, |
| vis: ty::Visibility::Public, |
| }), |
| |
| crate_loader, |
| macro_names: FxHashSet::default(), |
| builtin_macros: FxHashMap::default(), |
| macro_use_prelude: FxHashMap::default(), |
| all_macros: FxHashMap::default(), |
| macro_map: FxHashMap::default(), |
| non_macro_attrs: [non_macro_attr(false), non_macro_attr(true)], |
| invocations, |
| macro_defs, |
| local_macro_def_scopes: FxHashMap::default(), |
| name_already_seen: FxHashMap::default(), |
| potentially_unused_imports: Vec::new(), |
| struct_constructors: Default::default(), |
| unused_macros: FxHashSet::default(), |
| current_type_ascription: Vec::new(), |
| injected_crate: None, |
| } |
| } |
| |
| 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() |
| } |
| |
| /// 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 macro_def(&self, mut ctxt: SyntaxContext) -> DefId { |
| loop { |
| match self.macro_defs.get(&ctxt.outer()) { |
| Some(&def_id) => return def_id, |
| None => ctxt.remove_mark(), |
| }; |
| } |
| } |
| |
| /// Entry point to crate resolution. |
| pub fn resolve_crate(&mut self, krate: &Crate) { |
| ImportResolver { resolver: self }.finalize_imports(); |
| self.current_module = self.graph_root; |
| self.finalize_current_module_macro_resolutions(); |
| |
| visit::walk_crate(self, krate); |
| |
| check_unused::check_crate(self, krate); |
| self.report_errors(krate); |
| self.crate_loader.postprocess(krate); |
| } |
| |
| fn new_module( |
| &self, |
| parent: Module<'a>, |
| kind: ModuleKind, |
| normal_ancestor_id: DefId, |
| expansion: Mark, |
| span: Span, |
| ) -> Module<'a> { |
| let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expansion, span); |
| self.arenas.alloc_module(module) |
| } |
| |
| 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); |
| } |
| } |
| |
| /// 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, |
| record_used_id: Option<NodeId>, |
| path_span: Span) |
| -> Option<LexicalScopeBinding<'a>> { |
| assert!(ns == TypeNS || ns == ValueNS); |
| if ident.name == kw::Invalid { |
| return Some(LexicalScopeBinding::Res(Res::Err)); |
| } |
| ident.span = if ident.name == kw::SelfUpper { |
| // FIXME(jseyfried) improve `Self` hygiene |
| ident.span.with_ctxt(SyntaxContext::empty()) |
| } else if ns == TypeNS { |
| ident.span.modern() |
| } else { |
| ident.span.modern_and_legacy() |
| }; |
| |
| // 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 .. self.ribs[ns].len()).rev() { |
| debug!("walk rib\n{:?}", self.ribs[ns][i].bindings); |
| if let Some(res) = self.ribs[ns][i].bindings.get(&ident).cloned() { |
| // The ident resolves to a type parameter or local variable. |
| return Some(LexicalScopeBinding::Res( |
| self.validate_res_from_ribs(ns, i, res, record_used, path_span), |
| )); |
| } |
| |
| module = match self.ribs[ns][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, |
| 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.span = ident.span.modern(); |
| 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 orig_current_module = self.current_module; |
| self.current_module = module; // Lexical resolutions can never be a privacy error. |
| let result = self.resolve_ident_in_module_unadjusted( |
| ModuleOrUniformRoot::Module(module), |
| ident, |
| ns, |
| record_used, |
| path_span, |
| ); |
| self.current_module = orig_current_module; |
| |
| 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 { |
| if ns == TypeNS { |
| if let Some(binding) = self.extern_prelude_get(ident, !record_used) { |
| return Some(LexicalScopeBinding::Item(binding)); |
| } |
| } |
| if ns == TypeNS && is_known_tool(ident.name) { |
| let binding = (Res::ToolMod, ty::Visibility::Public, |
| DUMMY_SP, Mark::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, |
| 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_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()); |
| } |
| |
| 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 module.expansion.looks_like_proc_macro_derive() { |
| if parent.expansion.outer_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: Option<&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: Option<&ParentScope<'a>>, |
| record_used: bool, |
| path_span: Span |
| ) -> Result<&'a NameBinding<'a>, (Determinacy, Weak)> { |
| let orig_current_module = self.current_module; |
| match module { |
| ModuleOrUniformRoot::Module(module) => { |
| if let Some(def) = ident.span.modernize_and_adjust(module.expansion) { |
| self.current_module = self.macro_def_scope(def); |
| } |
| } |
| ModuleOrUniformRoot::ExternPrelude => { |
| ident.span.modernize_and_adjust(Mark::root()); |
| } |
| ModuleOrUniformRoot::CrateRootAndExternPrelude | |
| ModuleOrUniformRoot::CurrentScope => { |
| // No adjustments |
| } |
| } |
| let result = self.resolve_ident_in_module_unadjusted_ext( |
| module, ident, ns, parent_scope, false, record_used, path_span, |
| ); |
| self.current_module = orig_current_module; |
| 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(Mark::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 |
| } |
| |
| // AST resolution |
| // |
| // We maintain a list of value ribs and type ribs. |
| // |
| // Simultaneously, we keep track of the current position in the module |
| // graph in the `current_module` pointer. When we go to resolve a name in |
| // the value or type namespaces, we first look through all the ribs and |
| // then query the module graph. When we resolve a name in the module |
| // namespace, we can skip all the ribs (since nested modules are not |
| // allowed within blocks in Rust) and jump straight to the current module |
| // graph node. |
| // |
| // Named implementations are handled separately. When we find a method |
| // call, we consult the module node to find all of the implementations in |
| // scope. This information is lazily cached in the module node. We then |
| // generate a fake "implementation scope" containing all the |
| // implementations thus found, for compatibility with old resolve pass. |
| |
| pub fn with_scope<F, T>(&mut self, id: NodeId, f: F) -> T |
| where F: FnOnce(&mut Resolver<'_>) -> T |
| { |
| let id = self.definitions.local_def_id(id); |
| let module = self.module_map.get(&id).cloned(); // clones a reference |
| if let Some(module) = module { |
| // Move down in the graph. |
| let orig_module = replace(&mut self.current_module, module); |
| self.ribs[ValueNS].push(Rib::new(ModuleRibKind(module))); |
| self.ribs[TypeNS].push(Rib::new(ModuleRibKind(module))); |
| |
| self.finalize_current_module_macro_resolutions(); |
| let ret = f(self); |
| |
| self.current_module = orig_module; |
| self.ribs[ValueNS].pop(); |
| self.ribs[TypeNS].pop(); |
| ret |
| } else { |
| f(self) |
| } |
| } |
| |
| /// Searches the current set of local scopes for labels. Returns the first non-`None` label that |
| /// is returned by the given predicate function |
| /// |
| /// Stops after meeting a closure. |
| fn search_label<P, R>(&self, mut ident: Ident, pred: P) -> Option<R> |
| where P: Fn(&Rib<'_, NodeId>, Ident) -> Option<R> |
| { |
| for rib in self.label_ribs.iter().rev() { |
| match rib.kind { |
| NormalRibKind => {} |
| // If an invocation of this macro created `ident`, give up on `ident` |
| // and switch to `ident`'s source from the macro definition. |
| MacroDefinition(def) => { |
| if def == self.macro_def(ident.span.ctxt()) { |
| ident.span.remove_mark(); |
| } |
| } |
| _ => { |
| // Do not resolve labels across function boundary |
| return None; |
| } |
| } |
| let r = pred(rib, ident); |
| if r.is_some() { |
| return r; |
| } |
| } |
| None |
| } |
| |
| fn resolve_adt(&mut self, item: &Item, generics: &Generics) { |
| debug!("resolve_adt"); |
| self.with_current_self_item(item, |this| { |
| this.with_generic_param_rib(HasGenericParams(generics, ItemRibKind), |this| { |
| let item_def_id = this.definitions.local_def_id(item.id); |
| this.with_self_rib(Res::SelfTy(None, Some(item_def_id)), |this| { |
| visit::walk_item(this, item); |
| }); |
| }); |
| }); |
| } |
| |
| fn future_proof_import(&mut self, use_tree: &ast::UseTree) { |
| let segments = &use_tree.prefix.segments; |
| if !segments.is_empty() { |
| let ident = segments[0].ident; |
| if ident.is_path_segment_keyword() || ident.span.rust_2015() { |
| return; |
| } |
| |
| let nss = match use_tree.kind { |
| ast::UseTreeKind::Simple(..) if segments.len() == 1 => &[TypeNS, ValueNS][..], |
| _ => &[TypeNS], |
| }; |
| let report_error = |this: &Self, ns| { |
| let what = if ns == TypeNS { "type parameters" } else { "local variables" }; |
| this.session.span_err(ident.span, &format!("imports cannot refer to {}", what)); |
| }; |
| |
| for &ns in nss { |
| match self.resolve_ident_in_lexical_scope(ident, ns, None, use_tree.prefix.span) { |
| Some(LexicalScopeBinding::Res(..)) => { |
| report_error(self, ns); |
| } |
| Some(LexicalScopeBinding::Item(binding)) => { |
| let orig_blacklisted_binding = |
| mem::replace(&mut self.blacklisted_binding, Some(binding)); |
| if let Some(LexicalScopeBinding::Res(..)) = |
| self.resolve_ident_in_lexical_scope(ident, ns, None, |
| use_tree.prefix.span) { |
| report_error(self, ns); |
| } |
| self.blacklisted_binding = orig_blacklisted_binding; |
| } |
| None => {} |
| } |
| } |
| } else if let ast::UseTreeKind::Nested(use_trees) = &use_tree.kind { |
| for (use_tree, _) in use_trees { |
| self.future_proof_import(use_tree); |
| } |
| } |
| } |
| |
| fn resolve_item(&mut self, item: &Item) { |
| let name = item.ident.name; |
| debug!("(resolving item) resolving {} ({:?})", name, item.node); |
| |
| match item.node { |
| ItemKind::Ty(_, ref generics) => { |
| self.with_current_self_item(item, |this| { |
| this.with_generic_param_rib(HasGenericParams(generics, ItemRibKind), |this| { |
| let item_def_id = this.definitions.local_def_id(item.id); |
| this.with_self_rib(Res::SelfTy(Some(item_def_id), None), |this| { |
| visit::walk_item(this, item) |
| }) |
| }) |
| }); |
| } |
| |
| ItemKind::Existential(_, ref generics) | |
| ItemKind::Fn(_, _, ref generics, _) => { |
| self.with_generic_param_rib( |
| HasGenericParams(generics, ItemRibKind), |
| |this| visit::walk_item(this, item) |
| ); |
| } |
| |
| ItemKind::Enum(_, ref generics) | |
| ItemKind::Struct(_, ref generics) | |
| ItemKind::Union(_, ref generics) => { |
| self.resolve_adt(item, generics); |
| } |
| |
| ItemKind::Impl(.., ref generics, ref opt_trait_ref, ref self_type, ref impl_items) => |
| self.resolve_implementation(generics, |
| opt_trait_ref, |
| &self_type, |
| item.id, |
| impl_items), |
| |
| ItemKind::Trait(.., ref generics, ref bounds, ref trait_items) => { |
| // Create a new rib for the trait-wide type parameters. |
| self.with_generic_param_rib(HasGenericParams(generics, ItemRibKind), |this| { |
| let local_def_id = this.definitions.local_def_id(item.id); |
| this.with_self_rib(Res::SelfTy(Some(local_def_id), None), |this| { |
| this.visit_generics(generics); |
| walk_list!(this, visit_param_bound, bounds); |
| |
| for trait_item in trait_items { |
| let generic_params = HasGenericParams(&trait_item.generics, |
| AssocItemRibKind); |
| this.with_generic_param_rib(generic_params, |this| { |
| match trait_item.node { |
| TraitItemKind::Const(ref ty, ref default) => { |
| this.visit_ty(ty); |
| |
| // Only impose the restrictions of |
| // ConstRibKind for an actual constant |
| // expression in a provided default. |
| if let Some(ref expr) = *default{ |
| this.with_constant_rib(|this| { |
| this.visit_expr(expr); |
| }); |
| } |
| } |
| TraitItemKind::Method(_, _) => { |
| visit::walk_trait_item(this, trait_item) |
| } |
| TraitItemKind::Type(..) => { |
| visit::walk_trait_item(this, trait_item) |
| } |
| TraitItemKind::Macro(_) => { |
| panic!("unexpanded macro in resolve!") |
| } |
| }; |
| }); |
| } |
| }); |
| }); |
| } |
| |
| ItemKind::TraitAlias(ref generics, ref bounds) => { |
| // Create a new rib for the trait-wide type parameters. |
| self.with_generic_param_rib(HasGenericParams(generics, ItemRibKind), |this| { |
| let local_def_id = this.definitions.local_def_id(item.id); |
| this.with_self_rib(Res::SelfTy(Some(local_def_id), None), |this| { |
| this.visit_generics(generics); |
| walk_list!(this, visit_param_bound, bounds); |
| }); |
| }); |
| } |
| |
| ItemKind::Mod(_) | ItemKind::ForeignMod(_) => { |
| self.with_scope(item.id, |this| { |
| visit::walk_item(this, item); |
| }); |
| } |
| |
| ItemKind::Static(ref ty, _, ref expr) | |
| ItemKind::Const(ref ty, ref expr) => { |
| debug!("resolve_item ItemKind::Const"); |
| self.with_item_rib(|this| { |
| this.visit_ty(ty); |
| this.with_constant_rib(|this| { |
| this.visit_expr(expr); |
| }); |
| }); |
| } |
| |
| ItemKind::Use(ref use_tree) => { |
| self.future_proof_import(use_tree); |
| } |
| |
| ItemKind::ExternCrate(..) | |
| ItemKind::MacroDef(..) | ItemKind::GlobalAsm(..) => { |
| // do nothing, these are just around to be encoded |
| } |
| |
| ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"), |
| } |
| } |
| |
| fn with_generic_param_rib<'b, F>(&'b mut self, generic_params: GenericParameters<'a, 'b>, f: F) |
| where F: FnOnce(&mut Resolver<'_>) |
| { |
| debug!("with_generic_param_rib"); |
| match generic_params { |
| HasGenericParams(generics, rib_kind) => { |
| let mut function_type_rib = Rib::new(rib_kind); |
| let mut function_value_rib = Rib::new(rib_kind); |
| let mut seen_bindings = FxHashMap::default(); |
| for param in &generics.params { |
| match param.kind { |
| GenericParamKind::Lifetime { .. } => {} |
| GenericParamKind::Type { .. } => { |
| let ident = param.ident.modern(); |
| debug!("with_generic_param_rib: {}", param.id); |
| |
| if seen_bindings.contains_key(&ident) { |
| let span = seen_bindings.get(&ident).unwrap(); |
| let err = ResolutionError::NameAlreadyUsedInParameterList( |
| ident.name, |
| span, |
| ); |
| resolve_error(self, param.ident.span, err); |
| } |
| seen_bindings.entry(ident).or_insert(param.ident.span); |
| |
| // Plain insert (no renaming). |
| let res = Res::Def( |
| DefKind::TyParam, |
| self.definitions.local_def_id(param.id), |
| ); |
| function_type_rib.bindings.insert(ident, res); |
| self.record_partial_res(param.id, PartialRes::new(res)); |
| } |
| GenericParamKind::Const { .. } => { |
| let ident = param.ident.modern(); |
| debug!("with_generic_param_rib: {}", param.id); |
| |
| if seen_bindings.contains_key(&ident) { |
| let span = seen_bindings.get(&ident).unwrap(); |
| let err = ResolutionError::NameAlreadyUsedInParameterList( |
| ident.name, |
| span, |
| ); |
| resolve_error(self, param.ident.span, err); |
| } |
| seen_bindings.entry(ident).or_insert(param.ident.span); |
| |
| let res = Res::Def( |
| DefKind::ConstParam, |
| self.definitions.local_def_id(param.id), |
| ); |
| function_value_rib.bindings.insert(ident, res); |
| self.record_partial_res(param.id, PartialRes::new(res)); |
| } |
| } |
| } |
| self.ribs[ValueNS].push(function_value_rib); |
| self.ribs[TypeNS].push(function_type_rib); |
| } |
| |
| NoGenericParams => { |
| // Nothing to do. |
| } |
| } |
| |
| f(self); |
| |
| if let HasGenericParams(..) = generic_params { |
| self.ribs[TypeNS].pop(); |
| self.ribs[ValueNS].pop(); |
| } |
| } |
| |
| fn with_label_rib<F>(&mut self, f: F) |
| where F: FnOnce(&mut Resolver<'_>) |
| { |
| self.label_ribs.push(Rib::new(NormalRibKind)); |
| f(self); |
| self.label_ribs.pop(); |
| } |
| |
| fn with_item_rib<F>(&mut self, f: F) |
| where F: FnOnce(&mut Resolver<'_>) |
| { |
| self.ribs[ValueNS].push(Rib::new(ItemRibKind)); |
| self.ribs[TypeNS].push(Rib::new(ItemRibKind)); |
| f(self); |
| self.ribs[TypeNS].pop(); |
| self.ribs[ValueNS].pop(); |
| } |
| |
| fn with_constant_rib<F>(&mut self, f: F) |
| where F: FnOnce(&mut Resolver<'_>) |
| { |
| debug!("with_constant_rib"); |
| self.ribs[ValueNS].push(Rib::new(ConstantItemRibKind)); |
| self.label_ribs.push(Rib::new(ConstantItemRibKind)); |
| f(self); |
| self.label_ribs.pop(); |
| self.ribs[ValueNS].pop(); |
| } |
| |
| fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T |
| where F: FnOnce(&mut Resolver<'_>) -> T |
| { |
| // Handle nested impls (inside fn bodies) |
| let previous_value = replace(&mut self.current_self_type, Some(self_type.clone())); |
| let result = f(self); |
| self.current_self_type = previous_value; |
| result |
| } |
| |
| fn with_current_self_item<T, F>(&mut self, self_item: &Item, f: F) -> T |
| where F: FnOnce(&mut Resolver<'_>) -> T |
| { |
| let previous_value = replace(&mut self.current_self_item, Some(self_item.id)); |
| let result = f(self); |
| self.current_self_item = previous_value; |
| result |
| } |
| |
| /// This is called to resolve a trait reference from an `impl` (i.e., `impl Trait for Foo`). |
| fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T |
| where F: FnOnce(&mut Resolver<'_>, Option<DefId>) -> T |
| { |
| let mut new_val = None; |
| let mut new_id = None; |
| if let Some(trait_ref) = opt_trait_ref { |
| let path: Vec<_> = Segment::from_path(&trait_ref.path); |
| let res = self.smart_resolve_path_fragment( |
| trait_ref.ref_id, |
| None, |
| &path, |
| trait_ref.path.span, |
| PathSource::Trait(AliasPossibility::No), |
| CrateLint::SimplePath(trait_ref.ref_id), |
| ).base_res(); |
| if res != Res::Err { |
| new_id = Some(res.def_id()); |
| let span = trait_ref.path.span; |
| if let PathResult::Module(ModuleOrUniformRoot::Module(module)) = |
| self.resolve_path_without_parent_scope( |
| &path, |
| Some(TypeNS), |
| false, |
| span, |
| CrateLint::SimplePath(trait_ref.ref_id), |
| ) |
| { |
| new_val = Some((module, trait_ref.clone())); |
| } |
| } |
| } |
| let original_trait_ref = replace(&mut self.current_trait_ref, new_val); |
| let result = f(self, new_id); |
| self.current_trait_ref = original_trait_ref; |
| result |
| } |
| |
| fn with_self_rib<F>(&mut self, self_res: Res, f: F) |
| where F: FnOnce(&mut Resolver<'_>) |
| { |
| let mut self_type_rib = Rib::new(NormalRibKind); |
| |
| // Plain insert (no renaming, since types are not currently hygienic) |
| self_type_rib.bindings.insert(Ident::with_empty_ctxt(kw::SelfUpper), self_res); |
| self.ribs[TypeNS].push(self_type_rib); |
| f(self); |
| self.ribs[TypeNS].pop(); |
| } |
| |
| fn with_self_struct_ctor_rib<F>(&mut self, impl_id: DefId, f: F) |
| where F: FnOnce(&mut Resolver<'_>) |
| { |
| let self_res = Res::SelfCtor(impl_id); |
| let mut self_type_rib = Rib::new(NormalRibKind); |
| self_type_rib.bindings.insert(Ident::with_empty_ctxt(kw::SelfUpper), self_res); |
| self.ribs[ValueNS].push(self_type_rib); |
| f(self); |
| self.ribs[ValueNS].pop(); |
| } |
| |
| fn resolve_implementation(&mut self, |
| generics: &Generics, |
| opt_trait_reference: &Option<TraitRef>, |
| self_type: &Ty, |
| item_id: NodeId, |
| impl_items: &[ImplItem]) { |
| debug!("resolve_implementation"); |
| // If applicable, create a rib for the type parameters. |
| self.with_generic_param_rib(HasGenericParams(generics, ItemRibKind), |this| { |
| // Dummy self type for better errors if `Self` is used in the trait path. |
| this.with_self_rib(Res::SelfTy(None, None), |this| { |
| // Resolve the trait reference, if necessary. |
| this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| { |
| let item_def_id = this.definitions.local_def_id(item_id); |
| this.with_self_rib(Res::SelfTy(trait_id, Some(item_def_id)), |this| { |
| if let Some(trait_ref) = opt_trait_reference.as_ref() { |
| // Resolve type arguments in the trait path. |
| visit::walk_trait_ref(this, trait_ref); |
| } |
| // Resolve the self type. |
| this.visit_ty(self_type); |
| // Resolve the generic parameters. |
| this.visit_generics(generics); |
| // Resolve the items within the impl. |
| this.with_current_self_type(self_type, |this| { |
| this.with_self_struct_ctor_rib(item_def_id, |this| { |
| debug!("resolve_implementation with_self_struct_ctor_rib"); |
| for impl_item in impl_items { |
| this.resolve_visibility(&impl_item.vis); |
| |
| // We also need a new scope for the impl item type parameters. |
| let generic_params = HasGenericParams(&impl_item.generics, |
| AssocItemRibKind); |
| this.with_generic_param_rib(generic_params, |this| { |
| use self::ResolutionError::*; |
| match impl_item.node { |
| ImplItemKind::Const(..) => { |
| debug!( |
| "resolve_implementation ImplItemKind::Const", |
| ); |
| // If this is a trait impl, ensure the const |
| // exists in trait |
| this.check_trait_item( |
| impl_item.ident, |
| ValueNS, |
| impl_item.span, |
| |n, s| ConstNotMemberOfTrait(n, s), |
| ); |
| |
| this.with_constant_rib(|this| { |
| visit::walk_impl_item(this, impl_item) |
| }); |
| } |
| ImplItemKind::Method(..) => { |
| // If this is a trait impl, ensure the method |
| // exists in trait |
| this.check_trait_item(impl_item.ident, |
| ValueNS, |
| impl_item.span, |
| |n, s| MethodNotMemberOfTrait(n, s)); |
| |
| visit::walk_impl_item(this, impl_item); |
| } |
| ImplItemKind::Type(ref ty) => { |
| // If this is a trait impl, ensure the type |
| // exists in trait |
| this.check_trait_item(impl_item.ident, |
| TypeNS, |
| impl_item.span, |
| |n, s| TypeNotMemberOfTrait(n, s)); |
| |
| this.visit_ty(ty); |
| } |
| ImplItemKind::Existential(ref bounds) => { |
| // If this is a trait impl, ensure the type |
| // exists in trait |
| this.check_trait_item(impl_item.ident, |
| TypeNS, |
| impl_item.span, |
| |n, s| TypeNotMemberOfTrait(n, s)); |
| |
| for bound in bounds { |
| this.visit_param_bound(bound); |
| } |
| } |
| ImplItemKind::Macro(_) => |
| panic!("unexpanded macro in resolve!"), |
| } |
| }); |
| } |
| }); |
| }); |
| }); |
| }); |
| }); |
| }); |
| } |
| |
| fn check_trait_item<F>(&mut self, ident: Ident, ns: Namespace, span: Span, err: F) |
| where F: FnOnce(Name, &str) -> ResolutionError<'_> |
| { |
| // If there is a TraitRef in scope for an impl, then the method must be in the |
| // trait. |
| if let Some((module, _)) = self.current_trait_ref { |
| if self.resolve_ident_in_module( |
| ModuleOrUniformRoot::Module(module), |
| ident, |
| ns, |
| None, |
| false, |
| span, |
| ).is_err() { |
| let path = &self.current_trait_ref.as_ref().unwrap().1.path; |
| resolve_error(self, span, err(ident.name, &path_names_to_string(path))); |
| } |
| } |
| } |
| |
| fn resolve_local(&mut self, local: &Local) { |
| // Resolve the type. |
| walk_list!(self, visit_ty, &local.ty); |
| |
| // Resolve the initializer. |
| walk_list!(self, visit_expr, &local.init); |
| |
| // Resolve the pattern. |
| self.resolve_pattern(&local.pat, PatternSource::Let, &mut FxHashMap::default()); |
| } |
| |
| // build a map from pattern identifiers to binding-info's. |
| // this is done hygienically. This could arise for a macro |
| // that expands into an or-pattern where one 'x' was from the |
| // user and one 'x' came from the macro. |
| fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap { |
| let mut binding_map = FxHashMap::default(); |
| |
| pat.walk(&mut |pat| { |
| if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node { |
| if sub_pat.is_some() || match self.partial_res_map.get(&pat.id) |
| .map(|res| res.base_res()) { |
| Some(Res::Local(..)) => true, |
| _ => false, |
| } { |
| let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode }; |
| binding_map.insert(ident, binding_info); |
| } |
| } |
| true |
| }); |
| |
| binding_map |
| } |
| |
| // Checks that all of the arms in an or-pattern have exactly the |
| // same set of bindings, with the same binding modes for each. |
| fn check_consistent_bindings(&mut self, pats: &[P<Pat>]) { |
| if pats.is_empty() { |
| return; |
| } |
| |
| let mut missing_vars = FxHashMap::default(); |
| let mut inconsistent_vars = FxHashMap::default(); |
| for (i, p) in pats.iter().enumerate() { |
| let map_i = self.binding_mode_map(&p); |
| |
| for (j, q) in pats.iter().enumerate() { |
| if i == j { |
| continue; |
| } |
| |
| let map_j = self.binding_mode_map(&q); |
| for (&key, &binding_i) in &map_i { |
| if map_j.is_empty() { // Account for missing bindings when |
| let binding_error = missing_vars // `map_j` has none. |
| .entry(key.name) |
| .or_insert(BindingError { |
| name: key.name, |
| origin: BTreeSet::new(), |
| target: BTreeSet::new(), |
| }); |
| binding_error.origin.insert(binding_i.span); |
| binding_error.target.insert(q.span); |
| } |
| for (&key_j, &binding_j) in &map_j { |
| match map_i.get(&key_j) { |
| None => { // missing binding |
| let binding_error = missing_vars |
| .entry(key_j.name) |
| .or_insert(BindingError { |
| name: key_j.name, |
| origin: BTreeSet::new(), |
| target: BTreeSet::new(), |
| }); |
| binding_error.origin.insert(binding_j.span); |
| binding_error.target.insert(p.span); |
| } |
| Some(binding_i) => { // check consistent binding |
| if binding_i.binding_mode != binding_j.binding_mode { |
| inconsistent_vars |
| .entry(key.name) |
| .or_insert((binding_j.span, binding_i.span)); |
| } |
| } |
| } |
| } |
| } |
| } |
| } |
| let mut missing_vars = missing_vars.iter().collect::<Vec<_>>(); |
| missing_vars.sort(); |
| for (_, v) in missing_vars { |
| resolve_error(self, |
| *v.origin.iter().next().unwrap(), |
| ResolutionError::VariableNotBoundInPattern(v)); |
| } |
| let mut inconsistent_vars = inconsistent_vars.iter().collect::<Vec<_>>(); |
| inconsistent_vars.sort(); |
| for (name, v) in inconsistent_vars { |
| resolve_error(self, v.0, ResolutionError::VariableBoundWithDifferentMode(*name, v.1)); |
| } |
| } |
| |
| fn resolve_arm(&mut self, arm: &Arm) { |
| self.ribs[ValueNS].push(Rib::new(NormalRibKind)); |
| |
| self.resolve_pats(&arm.pats, PatternSource::Match); |
| |
| if let Some(ast::Guard::If(ref expr)) = arm.guard { |
| self.visit_expr(expr) |
| } |
| self.visit_expr(&arm.body); |
| |
| self.ribs[ValueNS].pop(); |
| } |
| |
| /// Arising from `source`, resolve a sequence of patterns (top level or-patterns). |
| fn resolve_pats(&mut self, pats: &[P<Pat>], source: PatternSource) { |
| let mut bindings_list = FxHashMap::default(); |
| for pat in pats { |
| self.resolve_pattern(pat, source, &mut bindings_list); |
| } |
| // This has to happen *after* we determine which pat_idents are variants |
| self.check_consistent_bindings(pats); |
| } |
| |
| fn resolve_block(&mut self, block: &Block) { |
| debug!("(resolving block) entering block"); |
| // Move down in the graph, if there's an anonymous module rooted here. |
| let orig_module = self.current_module; |
| let anonymous_module = self.block_map.get(&block.id).cloned(); // clones a reference |
| |
| let mut num_macro_definition_ribs = 0; |
| if let Some(anonymous_module) = anonymous_module { |
| debug!("(resolving block) found anonymous module, moving down"); |
| self.ribs[ValueNS].push(Rib::new(ModuleRibKind(anonymous_module))); |
| self.ribs[TypeNS].push(Rib::new(ModuleRibKind(anonymous_module))); |
| self.current_module = anonymous_module; |
| self.finalize_current_module_macro_resolutions(); |
| } else { |
| self.ribs[ValueNS].push(Rib::new(NormalRibKind)); |
| } |
| |
| // Descend into the block. |
| for stmt in &block.stmts { |
| if let ast::StmtKind::Item(ref item) = stmt.node { |
| if let ast::ItemKind::MacroDef(..) = item.node { |
| num_macro_definition_ribs += 1; |
| let res = self.definitions.local_def_id(item.id); |
| self.ribs[ValueNS].push(Rib::new(MacroDefinition(res))); |
| self.label_ribs.push(Rib::new(MacroDefinition(res))); |
| } |
| } |
| |
| self.visit_stmt(stmt); |
| } |
| |
| // Move back up. |
| self.current_module = orig_module; |
| for _ in 0 .. num_macro_definition_ribs { |
| self.ribs[ValueNS].pop(); |
| self.label_ribs.pop(); |
| } |
| self.ribs[ValueNS].pop(); |
| if anonymous_module.is_some() { |
| self.ribs[TypeNS].pop(); |
| } |
| debug!("(resolving block) leaving block"); |
| } |
| |
| fn fresh_binding(&mut self, |
| ident: Ident, |
| pat_id: NodeId, |
| outer_pat_id: NodeId, |
| pat_src: PatternSource, |
| bindings: &mut FxHashMap<Ident, NodeId>) |
| -> Res { |
| // Add the binding to the local ribs, if it |
| // doesn't already exist in the bindings map. (We |
| // must not add it if it's in the bindings map |
| // because that breaks the assumptions later |
| // passes make about or-patterns.) |
| let ident = ident.modern_and_legacy(); |
| let mut res = Res::Local(pat_id); |
| match bindings.get(&ident).cloned() { |
| Some(id) if id == outer_pat_id => { |
| // `Variant(a, a)`, error |
| resolve_error( |
| self, |
| ident.span, |
| ResolutionError::IdentifierBoundMoreThanOnceInSamePattern( |
| &ident.as_str()) |
| ); |
| } |
| Some(..) if pat_src == PatternSource::FnParam => { |
| // `fn f(a: u8, a: u8)`, error |
| resolve_error( |
| self, |
| ident.span, |
| ResolutionError::IdentifierBoundMoreThanOnceInParameterList( |
| &ident.as_str()) |
| ); |
| } |
| Some(..) if pat_src == PatternSource::Match || |
| pat_src == PatternSource::Let => { |
| // `Variant1(a) | Variant2(a)`, ok |
| // Reuse definition from the first `a`. |
| res = self.ribs[ValueNS].last_mut().unwrap().bindings[&ident]; |
| } |
| Some(..) => { |
| span_bug!(ident.span, "two bindings with the same name from \ |
| unexpected pattern source {:?}", pat_src); |
| } |
| None => { |
| // A completely fresh binding, add to the lists if it's valid. |
| if ident.name != kw::Invalid { |
| bindings.insert(ident, outer_pat_id); |
| self.ribs[ValueNS].last_mut().unwrap().bindings.insert(ident, res); |
| } |
| } |
| } |
| |
| res |
| } |
| |
| fn resolve_pattern(&mut self, |
| pat: &Pat, |
| pat_src: PatternSource, |
| // Maps idents to the node ID for the |
| // outermost pattern that binds them. |
| bindings: &mut FxHashMap<Ident, NodeId>) { |
| // Visit all direct subpatterns of this pattern. |
| let outer_pat_id = pat.id; |
| pat.walk(&mut |pat| { |
| debug!("resolve_pattern pat={:?} node={:?}", pat, pat.node); |
| match pat.node { |
| PatKind::Ident(bmode, ident, ref opt_pat) => { |
| // First try to resolve the identifier as some existing |
| // entity, then fall back to a fresh binding. |
| let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, |
| None, pat.span) |
| .and_then(LexicalScopeBinding::item); |
| let res = binding.map(NameBinding::res).and_then(|res| { |
| let is_syntactic_ambiguity = opt_pat.is_none() && |
| bmode == BindingMode::ByValue(Mutability::Immutable); |
| match res { |
| Res::Def(DefKind::Ctor(_, CtorKind::Const), _) | |
| Res::Def(DefKind::Const, _) if is_syntactic_ambiguity => { |
| // Disambiguate in favor of a unit struct/variant |
| // or constant pattern. |
| self.record_use(ident, ValueNS, binding.unwrap(), false); |
| Some(res) |
| } |
| Res::Def(DefKind::Ctor(..), _) |
| | Res::Def(DefKind::Const, _) |
| | Res::Def(DefKind::Static, _) => { |
| // This is unambiguously a fresh binding, either syntactically |
| // (e.g., `IDENT @ PAT` or `ref IDENT`) or because `IDENT` resolves |
| // to something unusable as a pattern (e.g., constructor function), |
| // but we still conservatively report an error, see |
| // issues/33118#issuecomment-233962221 for one reason why. |
| resolve_error( |
| self, |
| ident.span, |
| ResolutionError::BindingShadowsSomethingUnacceptable( |
| pat_src.descr(), ident.name, binding.unwrap()) |
| ); |
| None |
| } |
| Res::Def(DefKind::Fn, _) | Res::Err => { |
| // These entities are explicitly allowed |
| // to be shadowed by fresh bindings. |
| None |
| } |
| res => { |
| span_bug!(ident.span, "unexpected resolution for an \ |
| identifier in pattern: {:?}", res); |
| } |
| } |
| }).unwrap_or_else(|| { |
| self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings) |
| }); |
| |
| self.record_partial_res(pat.id, PartialRes::new(res)); |
| } |
| |
| PatKind::TupleStruct(ref path, ..) => { |
| self.smart_resolve_path(pat.id, None, path, PathSource::TupleStruct); |
| } |
| |
| PatKind::Path(ref qself, ref path) => { |
| self.smart_resolve_path(pat.id, qself.as_ref(), path, PathSource::Pat); |
| } |
| |
| PatKind::Struct(ref path, ..) => { |
| self.smart_resolve_path(pat.id, None, path, PathSource::Struct); |
| } |
| |
| _ => {} |
| } |
| true |
| }); |
| |
| visit::walk_pat(self, pat); |
| } |
| |
| // High-level and context dependent path resolution routine. |
| // Resolves the path and records the resolution into definition map. |
| // If resolution fails tries several techniques to find likely |
| // resolution candidates, suggest imports or other help, and report |
| // errors in user friendly way. |
| fn smart_resolve_path(&mut self, |
| id: NodeId, |
| qself: Option<&QSelf>, |
| path: &Path, |
| source: PathSource<'_>) { |
| self.smart_resolve_path_fragment( |
| id, |
| qself, |
| &Segment::from_path(path), |
| path.span, |
| source, |
| CrateLint::SimplePath(id), |
| ); |
| } |
| |
| fn smart_resolve_path_fragment(&mut self, |
| id: NodeId, |
| qself: Option<&QSelf>, |
| path: &[Segment], |
| span: Span, |
| source: PathSource<'_>, |
| crate_lint: CrateLint) |
| -> PartialRes { |
| let ns = source.namespace(); |
| let is_expected = &|res| source.is_expected(res); |
| |
| let report_errors = |this: &mut Self, res: Option<Res>| { |
| let (err, candidates) = this.smart_resolve_report_errors(path, span, source, res); |
| let def_id = this.current_module.normal_ancestor_id; |
| let node_id = this.definitions.as_local_node_id(def_id).unwrap(); |
| let better = res.is_some(); |
| this.use_injections.push(UseError { err, candidates, node_id, better }); |
| PartialRes::new(Res::Err) |
| }; |
| |
| let partial_res = match self.resolve_qpath_anywhere( |
| id, |
| qself, |
| path, |
| ns, |
| span, |
| source.defer_to_typeck(), |
| source.global_by_default(), |
| crate_lint, |
| ) { |
| Some(partial_res) if partial_res.unresolved_segments() == 0 => { |
| if is_expected(partial_res.base_res()) || partial_res.base_res() == Res::Err { |
| partial_res |
| } else { |
| // Add a temporary hack to smooth the transition to new struct ctor |
| // visibility rules. See #38932 for more details. |
| let mut res = None; |
| if let Res::Def(DefKind::Struct, def_id) = partial_res.base_res() { |
| if let Some((ctor_res, ctor_vis)) |
| = self.struct_constructors.get(&def_id).cloned() { |
| if is_expected(ctor_res) && self.is_accessible(ctor_vis) { |
| let lint = lint::builtin::LEGACY_CONSTRUCTOR_VISIBILITY; |
| self.session.buffer_lint(lint, id, span, |
| "private struct constructors are not usable through \ |
| re-exports in outer modules", |
| ); |
| res = Some(PartialRes::new(ctor_res)); |
| } |
| } |
| } |
| |
| res.unwrap_or_else(|| report_errors(self, Some(partial_res.base_res()))) |
| } |
| } |
| Some(partial_res) if source.defer_to_typeck() => { |
| // Not fully resolved associated item `T::A::B` or `<T as Tr>::A::B` |
| // or `<T>::A::B`. If `B` should be resolved in value namespace then |
| // it needs to be added to the trait map. |
| if ns == ValueNS { |
| let item_name = path.last().unwrap().ident; |
| let traits = self.get_traits_containing_item(item_name, ns); |
| self.trait_map.insert(id, traits); |
| } |
| |
| let mut std_path = vec![Segment::from_ident(Ident::with_empty_ctxt(sym::std))]; |
| std_path.extend(path); |
| if self.primitive_type_table.primitive_types.contains_key(&path[0].ident.name) { |
| let cl = CrateLint::No; |
| let ns = Some(ns); |
| if let PathResult::Module(_) | PathResult::NonModule(_) = |
| self.resolve_path_without_parent_scope(&std_path, ns, false, span, cl) |
| { |
| // check if we wrote `str::from_utf8` instead of `std::str::from_utf8` |
| let item_span = path.iter().last().map(|segment| segment.ident.span) |
| .unwrap_or(span); |
| debug!("accessed item from `std` submodule as a bare type {:?}", std_path); |
| let mut hm = self.session.confused_type_with_std_module.borrow_mut(); |
| hm.insert(item_span, span); |
| // In some places (E0223) we only have access to the full path |
| hm.insert(span, span); |
| } |
| } |
| partial_res |
| } |
| _ => report_errors(self, None) |
| }; |
| |
| if let PathSource::TraitItem(..) = source {} else { |
| // Avoid recording definition of `A::B` in `<T as A>::B::C`. |
| self.record_partial_res(id, partial_res); |
| } |
| partial_res |
| } |
| |
| /// Only used in a specific case of type ascription suggestions |
| #[doc(hidden)] |
| fn get_colon_suggestion_span(&self, start: Span) -> Span { |
| let cm = self.session.source_map(); |
| start.to(cm.next_point(start)) |
| } |
| |
| fn type_ascription_suggestion( |
| &self, |
| err: &mut DiagnosticBuilder<'_>, |
| base_span: Span, |
| ) { |
| debug!("type_ascription_suggetion {:?}", base_span); |
| let cm = self.session.source_map(); |
| let base_snippet = cm.span_to_snippet(base_span); |
| debug!("self.current_type_ascription {:?}", self.current_type_ascription); |
| if let Some(sp) = self.current_type_ascription.last() { |
| let mut sp = *sp; |
| loop { |
| // Try to find the `:`; bail on first non-':' / non-whitespace. |
| sp = cm.next_point(sp); |
| if let Ok(snippet) = cm.span_to_snippet(sp.to(cm.next_point(sp))) { |
| let line_sp = cm.lookup_char_pos(sp.hi()).line; |
| let line_base_sp = cm.lookup_char_pos(base_span.lo()).line; |
| if snippet == ":" { |
| let mut show_label = true; |
| if line_sp != line_base_sp { |
| err.span_suggestion_short( |
| sp, |
| "did you mean to use `;` here instead?", |
| ";".to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| } else { |
| let colon_sp = self.get_colon_suggestion_span(sp); |
| let after_colon_sp = self.get_colon_suggestion_span( |
| colon_sp.shrink_to_hi(), |
| ); |
| if !cm.span_to_snippet(after_colon_sp).map(|s| s == " ") |
| .unwrap_or(false) |
| { |
| err.span_suggestion( |
| colon_sp, |
| "maybe you meant to write a path separator here", |
| "::".to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| show_label = false; |
| } |
| if let Ok(base_snippet) = base_snippet { |
| let mut sp = after_colon_sp; |
| for _ in 0..100 { |
| // Try to find an assignment |
| sp = cm.next_point(sp); |
| let snippet = cm.span_to_snippet(sp.to(cm.next_point(sp))); |
| match snippet { |
| Ok(ref x) if x.as_str() == "=" => { |
| err.span_suggestion( |
| base_span, |
| "maybe you meant to write an assignment here", |
| format!("let {}", base_snippet), |
| Applicability::MaybeIncorrect, |
| ); |
| show_label = false; |
| break; |
| } |
| Ok(ref x) if x.as_str() == "\n" => break, |
| Err(_) => break, |
| Ok(_) => {} |
| } |
| } |
| } |
| } |
| if show_label { |
| err.span_label(base_span, |
| "expecting a type here because of type ascription"); |
| } |
| break; |
| } else if !snippet.trim().is_empty() { |
| debug!("tried to find type ascription `:` token, couldn't find it"); |
| break; |
| } |
| } else { |
| break; |
| } |
| } |
| } |
| } |
| |
| fn self_type_is_available(&mut self, span: Span) -> bool { |
| let binding = self.resolve_ident_in_lexical_scope(Ident::with_empty_ctxt(kw::SelfUpper), |
| TypeNS, None, span); |
| if let Some(LexicalScopeBinding::Res(res)) = binding { res != Res::Err } else { false } |
| } |
| |
| fn self_value_is_available(&mut self, self_span: Span, path_span: Span) -> bool { |
| let ident = Ident::new(kw::SelfLower, self_span); |
| let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, None, path_span); |
| if let Some(LexicalScopeBinding::Res(res)) = binding { res != Res::Err } else { false } |
| } |
| |
| // Resolve in alternative namespaces if resolution in the primary namespace fails. |
| fn resolve_qpath_anywhere( |
| &mut self, |
| id: NodeId, |
| qself: Option<&QSelf>, |
| path: &[Segment], |
| primary_ns: Namespace, |
| span: Span, |
| defer_to_typeck: bool, |
| global_by_default: bool, |
| crate_lint: CrateLint, |
| ) -> Option<PartialRes> { |
| let mut fin_res = None; |
| // FIXME: can't resolve paths in macro namespace yet, macros are |
| // processed by the little special hack below. |
| for (i, ns) in [primary_ns, TypeNS, ValueNS, /*MacroNS*/].iter().cloned().enumerate() { |
| if i == 0 || ns != primary_ns { |
| match self.resolve_qpath(id, qself, path, ns, span, global_by_default, crate_lint) { |
| // If defer_to_typeck, then resolution > no resolution, |
| // otherwise full resolution > partial resolution > no resolution. |
| Some(partial_res) if partial_res.unresolved_segments() == 0 || |
| defer_to_typeck => |
| return Some(partial_res), |
| partial_res => if fin_res.is_none() { fin_res = partial_res }, |
| }; |
| } |
| } |
| if primary_ns != MacroNS && |
| (self.macro_names.contains(&path[0].ident.modern()) || |
| self.builtin_macros.get(&path[0].ident.name).cloned() |
| .and_then(NameBinding::macro_kind) == Some(MacroKind::Bang) || |
| self.macro_use_prelude.get(&path[0].ident.name).cloned() |
| .and_then(NameBinding::macro_kind) == Some(MacroKind::Bang)) { |
| // Return some dummy definition, it's enough for error reporting. |
| return Some(PartialRes::new(Res::Def( |
| DefKind::Macro(MacroKind::Bang), |
| DefId::local(CRATE_DEF_INDEX), |
| ))); |
| } |
| fin_res |
| } |
| |
| /// Handles paths that may refer to associated items. |
| fn resolve_qpath( |
| &mut self, |
| id: NodeId, |
| qself: Option<&QSelf>, |
| path: &[Segment], |
| ns: Namespace, |
| span: Span, |
| global_by_default: bool, |
| crate_lint: CrateLint, |
| ) -> Option<PartialRes> { |
| debug!( |
| "resolve_qpath(id={:?}, qself={:?}, path={:?}, \ |
| ns={:?}, span={:?}, global_by_default={:?})", |
| id, |
| qself, |
| path, |
| ns, |
| span, |
| global_by_default, |
| ); |
| |
| if let Some(qself) = qself { |
| if qself.position == 0 { |
| // This is a case like `<T>::B`, where there is no |
| // trait to resolve. In that case, we leave the `B` |
| // segment to be resolved by type-check. |
| return Some(PartialRes::with_unresolved_segments( |
| Res::Def(DefKind::Mod, DefId::local(CRATE_DEF_INDEX)), path.len() |
| )); |
| } |
| |
| // Make sure `A::B` in `<T as A::B>::C` is a trait item. |
| // |
| // Currently, `path` names the full item (`A::B::C`, in |
| // our example). so we extract the prefix of that that is |
| // the trait (the slice upto and including |
| // `qself.position`). And then we recursively resolve that, |
| // but with `qself` set to `None`. |
| // |
| // However, setting `qself` to none (but not changing the |
| // span) loses the information about where this path |
| // *actually* appears, so for the purposes of the crate |
| // lint we pass along information that this is the trait |
| // name from a fully qualified path, and this also |
| // contains the full span (the `CrateLint::QPathTrait`). |
| let ns = if qself.position + 1 == path.len() { ns } else { TypeNS }; |
| let partial_res = self.smart_resolve_path_fragment( |
| id, |
| None, |
| &path[..=qself.position], |
| span, |
| PathSource::TraitItem(ns), |
| CrateLint::QPathTrait { |
| qpath_id: id, |
| qpath_span: qself.path_span, |
| }, |
| ); |
| |
| // The remaining segments (the `C` in our example) will |
| // have to be resolved by type-check, since that requires doing |
| // trait resolution. |
| return Some(PartialRes::with_unresolved_segments( |
| partial_res.base_res(), |
| partial_res.unresolved_segments() + path.len() - qself.position - 1, |
| )); |
| } |
| |
| let result = match self.resolve_path_without_parent_scope( |
| &path, |
| Some(ns), |
| true, |
| span, |
| crate_lint, |
| ) { |
| PathResult::NonModule(path_res) => path_res, |
| PathResult::Module(ModuleOrUniformRoot::Module(module)) if !module.is_normal() => { |
| PartialRes::new(module.res().unwrap()) |
| } |
| // In `a(::assoc_item)*` `a` cannot be a module. If `a` does resolve to a module we |
| // don't report an error right away, but try to fallback to a primitive type. |
| // So, we are still able to successfully resolve something like |
| // |
| // use std::u8; // bring module u8 in scope |
| // fn f() -> u8 { // OK, resolves to primitive u8, not to std::u8 |
| // u8::max_value() // OK, resolves to associated function <u8>::max_value, |
| // // not to non-existent std::u8::max_value |
| // } |
| // |
| // Such behavior is required for backward compatibility. |
| // The same fallback is used when `a` resolves to nothing. |
| PathResult::Module(ModuleOrUniformRoot::Module(_)) | |
| PathResult::Failed { .. } |
| if (ns == TypeNS || path.len() > 1) && |
| self.primitive_type_table.primitive_types |
| .contains_key(&path[0].ident.name) => { |
| let prim = self.primitive_type_table.primitive_types[&path[0].ident.name]; |
| PartialRes::with_unresolved_segments(Res::PrimTy(prim), path.len() - 1) |
| } |
| PathResult::Module(ModuleOrUniformRoot::Module(module)) => |
| PartialRes::new(module.res().unwrap()), |
| PathResult::Failed { is_error_from_last_segment: false, span, label, suggestion } => { |
| resolve_error(self, span, ResolutionError::FailedToResolve { label, suggestion }); |
| PartialRes::new(Res::Err) |
| } |
| PathResult::Module(..) | PathResult::Failed { .. } => return None, |
| PathResult::Indeterminate => bug!("indetermined path result in resolve_qpath"), |
| }; |
| |
| if path.len() > 1 && !global_by_default && result.base_res() != Res::Err && |
| path[0].ident.name != kw::PathRoot && |
| path[0].ident.name != kw::DollarCrate { |
| let unqualified_result = { |
| match self.resolve_path_without_parent_scope( |
| &[*path.last().unwrap()], |
| Some(ns), |
| false, |
| span, |
| CrateLint::No, |
| ) { |
| PathResult::NonModule(path_res) => path_res.base_res(), |
| PathResult::Module(ModuleOrUniformRoot::Module(module)) => |
| module.res().unwrap(), |
| _ => return Some(result), |
| } |
| }; |
| if result.base_res() == unqualified_result { |
| let lint = lint::builtin::UNUSED_QUALIFICATIONS; |
| self.session.buffer_lint(lint, id, span, "unnecessary qualification") |
| } |
| } |
| |
| Some(result) |
| } |
| |
| fn resolve_path_without_parent_scope( |
| &mut self, |
| path: &[Segment], |
| opt_ns: Option<Namespace>, // `None` indicates a module path in import |
| record_used: bool, |
| path_span: Span, |
| crate_lint: CrateLint, |
| ) -> PathResult<'a> { |
| // Macro and import paths must have full parent scope available during resolution, |
| // other paths will do okay with parent module alone. |
| assert!(opt_ns != None && opt_ns != Some(MacroNS)); |
| let parent_scope = ParentScope { module: self.current_module, ..self.dummy_parent_scope() }; |
| self.resolve_path(path, opt_ns, &parent_scope, record_used, path_span, crate_lint) |
| } |
| |
| 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> { |
| let mut module = None; |
| let mut allow_super = true; |
| let mut second_binding = None; |
| self.current_module = parent_scope.module; |
| |
| 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, self.current_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, self.current_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, None, record_used, path_span) |
| } else if opt_ns.is_none() || opt_ns == Some(MacroNS) { |
| assert!(ns == TypeNS); |
| let scopes = if opt_ns.is_none() { ScopeSet::Import(ns) } else { ScopeSet::Module }; |
| 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, record_used_id, path_span) { |
| // 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 `extern 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, |
| ns: Namespace, |
| rib_index: usize, |
| res: Res, |
| record_used: bool, |
| span: Span, |
| ) -> Res { |
| debug!("validate_res_from_ribs({:?})", res); |
| let ribs = &self.ribs[ns][rib_index + 1..]; |
| |
| // An invalid forward use of a type parameter from a previous default. |
| if let ForwardTyParamBanRibKind = self.ribs[ns][rib_index].kind { |
| if record_used { |
| resolve_error(self, 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 = self.ribs[ns][rib_index].kind { |
| if record_used { |
| resolve_error(self, 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 { |
| resolve_error(self, span, AttemptToUseNonConstantValueInConstant); |
| } |
| return Res::Err; |
| } |
| } |
| } |
| if let Some(res_err) = res_err { |
| resolve_error(self, 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 { |
| resolve_error( |
| self, |
| 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 { |
| resolve_error( |
| self, |
| span, |
| ResolutionError::GenericParamsFromOuterFunction(res), |
| ); |
| } |
| return Res::Err; |
| } |
| } |
| } |
| _ => {} |
| } |
| res |
| } |
| |
| fn lookup_assoc_candidate<FilterFn>(&mut self, |
| ident: Ident, |
| ns: Namespace, |
| filter_fn: FilterFn) |
| -> Option<AssocSuggestion> |
| where FilterFn: Fn(Res) -> bool |
| { |
| fn extract_node_id(t: &Ty) -> Option<NodeId> { |
| match t.node { |
| TyKind::Path(None, _) => Some(t.id), |
| TyKind::Rptr(_, ref mut_ty) => extract_node_id(&mut_ty.ty), |
| // This doesn't handle the remaining `Ty` variants as they are not |
| // that commonly the self_type, it might be interesting to provide |
| // support for those in future. |
| _ => None, |
| } |
| } |
| |
| // Fields are generally expected in the same contexts as locals. |
| if filter_fn(Res::Local(ast::DUMMY_NODE_ID)) { |
| if let Some(node_id) = self.current_self_type.as_ref().and_then(extract_node_id) { |
| // Look for a field with the same name in the current self_type. |
| if let Some(resolution) = self.partial_res_map.get(&node_id) { |
| match resolution.base_res() { |
| Res::Def(DefKind::Struct, did) | Res::Def(DefKind::Union, did) |
| if resolution.unresolved_segments() == 0 => { |
| if let Some(field_names) = self.field_names.get(&did) { |
| if field_names.iter().any(|&field_name| ident.name == field_name) { |
| return Some(AssocSuggestion::Field); |
| } |
| } |
| } |
| _ => {} |
| } |
| } |
| } |
| } |
| |
| // Look for associated items in the current trait. |
| if let Some((module, _)) = self.current_trait_ref { |
| if let Ok(binding) = self.resolve_ident_in_module( |
| ModuleOrUniformRoot::Module(module), |
| ident, |
| ns, |
| None, |
| false, |
| module.span, |
| ) { |
| let res = binding.res(); |
| if filter_fn(res) { |
| return Some(if self.has_self.contains(&res.def_id()) { |
| AssocSuggestion::MethodWithSelf |
| } else { |
| AssocSuggestion::AssocItem |
| }); |
| } |
| } |
| } |
| |
| None |
| } |
| |
| fn lookup_typo_candidate<FilterFn>( |
| &mut self, |
| path: &[Segment], |
| ns: Namespace, |
| filter_fn: FilterFn, |
| span: Span, |
| ) -> Option<TypoSuggestion> |
| where |
| FilterFn: Fn(Res) -> bool, |
| { |
| let add_module_candidates = |module: Module<'_>, names: &mut Vec<TypoSuggestion>| { |
| for (&(ident, _), resolution) in module.resolutions.borrow().iter() { |
| if let Some(binding) = resolution.borrow().binding { |
| if filter_fn(binding.res()) { |
| names.push(TypoSuggestion { |
| candidate: ident.name, |
| article: binding.res().article(), |
| kind: binding.res().descr(), |
| }); |
| } |
| } |
| } |
| }; |
| |
| let mut names = Vec::new(); |
| if path.len() == 1 { |
| // Search in lexical scope. |
| // Walk backwards up the ribs in scope and collect candidates. |
| for rib in self.ribs[ns].iter().rev() { |
| // Locals and type parameters |
| for (ident, &res) in &rib.bindings { |
| if filter_fn(res) { |
| names.push(TypoSuggestion { |
| candidate: ident.name, |
| article: res.article(), |
| kind: res.descr(), |
| }); |
| } |
| } |
| // Items in scope |
| if let ModuleRibKind(module) = rib.kind { |
| // Items from this module |
| add_module_candidates(module, &mut names); |
| |
| if let ModuleKind::Block(..) = module.kind { |
| // We can see through blocks |
| } else { |
| // Items from the prelude |
| if !module.no_implicit_prelude { |
| names.extend(self.extern_prelude.clone().iter().flat_map(|(ident, _)| { |
| self.crate_loader |
| .maybe_process_path_extern(ident.name, ident.span) |
| .and_then(|crate_id| { |
| let crate_mod = Res::Def( |
| DefKind::Mod, |
| DefId { |
| krate: crate_id, |
| index: CRATE_DEF_INDEX, |
| }, |
| ); |
| |
| if filter_fn(crate_mod) { |
| Some(TypoSuggestion { |
| candidate: ident.name, |
| article: "a", |
| kind: "crate", |
| }) |
| } else { |
| None |
| } |
| }) |
| })); |
| |
| if let Some(prelude) = self.prelude { |
| add_module_candidates(prelude, &mut names); |
| } |
| } |
| break; |
| } |
| } |
| } |
| // Add primitive types to the mix |
| if filter_fn(Res::PrimTy(Bool)) { |
| names.extend( |
| self.primitive_type_table.primitive_types.iter().map(|(name, _)| { |
| TypoSuggestion { |
| candidate: *name, |
| article: "a", |
| kind: "primitive type", |
| } |
| }) |
| ) |
| } |
| } else { |
| // Search in module. |
| let mod_path = &path[..path.len() - 1]; |
| if let PathResult::Module(module) = self.resolve_path_without_parent_scope( |
| mod_path, Some(TypeNS), false, span, CrateLint::No |
| ) { |
| if let ModuleOrUniformRoot::Module(module) = module { |
| add_module_candidates(module, &mut names); |
| } |
| } |
| } |
| |
| let name = path[path.len() - 1].ident.name; |
| // Make sure error reporting is deterministic. |
| names.sort_by_cached_key(|suggestion| suggestion.candidate.as_str()); |
| |
| match find_best_match_for_name( |
| names.iter().map(|suggestion| &suggestion.candidate), |
| &name.as_str(), |
| None, |
| ) { |
| Some(found) if found != name => names |
| .into_iter() |
| .find(|suggestion| suggestion.candidate == found), |
| _ => None, |
| } |
| } |
| |
| fn with_resolved_label<F>(&mut self, label: Option<Label>, id: NodeId, f: F) |
| where F: FnOnce(&mut Resolver<'_>) |
| { |
| if let Some(label) = label { |
| self.unused_labels.insert(id, label.ident.span); |
| self.with_label_rib(|this| { |
| let ident = label.ident.modern_and_legacy(); |
| this.label_ribs.last_mut().unwrap().bindings.insert(ident, id); |
| f(this); |
| }); |
| } else { |
| f(self); |
| } |
| } |
| |
| fn resolve_labeled_block(&mut self, label: Option<Label>, id: NodeId, block: &Block) { |
| self.with_resolved_label(label, id, |this| this.visit_block(block)); |
| } |
| |
| fn resolve_expr(&mut self, expr: &Expr, parent: Option<&Expr>) { |
| // First, record candidate traits for this expression if it could |
| // result in the invocation of a method call. |
| |
| self.record_candidate_traits_for_expr_if_necessary(expr); |
| |
| // Next, resolve the node. |
| match expr.node { |
| ExprKind::Path(ref qself, ref path) => { |
| self.smart_resolve_path(expr.id, qself.as_ref(), path, PathSource::Expr(parent)); |
| visit::walk_expr(self, expr); |
| } |
| |
| ExprKind::Struct(ref path, ..) => { |
| self.smart_resolve_path(expr.id, None, path, PathSource::Struct); |
| visit::walk_expr(self, expr); |
| } |
| |
| ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => { |
| let node_id = self.search_label(label.ident, |rib, ident| { |
| rib.bindings.get(&ident.modern_and_legacy()).cloned() |
| }); |
| match node_id { |
| None => { |
| // Search again for close matches... |
| // Picks the first label that is "close enough", which is not necessarily |
| // the closest match |
| let close_match = self.search_label(label.ident, |rib, ident| { |
| let names = rib.bindings.iter().filter_map(|(id, _)| { |
| if id.span.ctxt() == label.ident.span.ctxt() { |
| Some(&id.name) |
| } else { |
| None |
| } |
| }); |
| find_best_match_for_name(names, &*ident.as_str(), None) |
| }); |
| self.record_partial_res(expr.id, PartialRes::new(Res::Err)); |
| resolve_error(self, |
| label.ident.span, |
| ResolutionError::UndeclaredLabel(&label.ident.as_str(), |
| close_match)); |
| } |
| Some(node_id) => { |
| // Since this res is a label, it is never read. |
| self.label_res_map.insert(expr.id, node_id); |
| self.unused_labels.remove(&node_id); |
| } |
| } |
| |
| // visit `break` argument if any |
| visit::walk_expr(self, expr); |
| } |
| |
| ExprKind::Let(ref pats, ref scrutinee) => { |
| self.visit_expr(scrutinee); |
| self.resolve_pats(pats, PatternSource::Let); |
| } |
| |
| ExprKind::If(ref cond, ref then, ref opt_else) => { |
| self.ribs[ValueNS].push(Rib::new(NormalRibKind)); |
| self.visit_expr(cond); |
| self.visit_block(then); |
| self.ribs[ValueNS].pop(); |
| |
| opt_else.as_ref().map(|expr| self.visit_expr(expr)); |
| } |
| |
| ExprKind::Loop(ref block, label) => self.resolve_labeled_block(label, expr.id, &block), |
| |
| ExprKind::While(ref subexpression, ref block, label) => { |
| self.with_resolved_label(label, expr.id, |this| { |
| this.ribs[ValueNS].push(Rib::new(NormalRibKind)); |
| this.visit_expr(subexpression); |
| this.visit_block(block); |
| this.ribs[ValueNS].pop(); |
| }); |
| } |
| |
| ExprKind::ForLoop(ref pattern, ref subexpression, ref block, label) => { |
| self.visit_expr(subexpression); |
| self.ribs[ValueNS].push(Rib::new(NormalRibKind)); |
| self.resolve_pattern(pattern, PatternSource::For, &mut FxHashMap::default()); |
| |
| self.resolve_labeled_block(label, expr.id, block); |
| |
| self.ribs[ValueNS].pop(); |
| } |
| |
| ExprKind::Block(ref block, label) => self.resolve_labeled_block(label, block.id, block), |
| |
| // Equivalent to `visit::walk_expr` + passing some context to children. |
| ExprKind::Field(ref subexpression, _) => { |
| self.resolve_expr(subexpression, Some(expr)); |
| } |
| ExprKind::MethodCall(ref segment, ref arguments) => { |
| let mut arguments = arguments.iter(); |
| self.resolve_expr(arguments.next().unwrap(), Some(expr)); |
| for argument in arguments { |
| self.resolve_expr(argument, None); |
| } |
| self.visit_path_segment(expr.span, segment); |
| } |
| |
| ExprKind::Call(ref callee, ref arguments) => { |
| self.resolve_expr(callee, Some(expr)); |
| for argument in arguments { |
| self.resolve_expr(argument, None); |
| } |
| } |
| ExprKind::Type(ref type_expr, _) => { |
| self.current_type_ascription.push(type_expr.span); |
| visit::walk_expr(self, expr); |
| self.current_type_ascription.pop(); |
| } |
| // `async |x| ...` gets desugared to `|x| future_from_generator(|| ...)`, so we need to |
| // resolve the arguments within the proper scopes so that usages of them inside the |
| // closure are detected as upvars rather than normal closure arg usages. |
| ExprKind::Closure( |
| _, IsAsync::Async { .. }, _, |
| ref fn_decl, ref body, _span, |
| ) => { |
| let rib_kind = NormalRibKind; |
| self.ribs[ValueNS].push(Rib::new(rib_kind)); |
| // Resolve arguments: |
| let mut bindings_list = FxHashMap::default(); |
| for argument in &fn_decl.inputs { |
| self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list); |
| self.visit_ty(&argument.ty); |
| } |
| // No need to resolve return type-- the outer closure return type is |
| // FunctionRetTy::Default |
| |
| // Now resolve the inner closure |
| { |
| // No need to resolve arguments: the inner closure has none. |
| // Resolve the return type: |
| visit::walk_fn_ret_ty(self, &fn_decl.output); |
| // Resolve the body |
| self.visit_expr(body); |
| } |
| self.ribs[ValueNS].pop(); |
| } |
| _ => { |
| visit::walk_expr(self, expr); |
| } |
| } |
| } |
| |
| fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) { |
| match expr.node { |
| ExprKind::Field(_, ident) => { |
| // FIXME(#6890): Even though you can't treat a method like a |
| // field, we need to add any trait methods we find that match |
| // the field name so that we can do some nice error reporting |
| // later on in typeck. |
| let traits = self.get_traits_containing_item(ident, ValueNS); |
| self.trait_map.insert(expr.id, traits); |
| } |
| ExprKind::MethodCall(ref segment, ..) => { |
| debug!("(recording candidate traits for expr) recording traits for {}", |
| expr.id); |
| let traits = self.get_traits_containing_item(segment.ident, ValueNS); |
| self.trait_map.insert(expr.id, traits); |
| } |
| _ => { |
| // Nothing to do. |
| } |
| } |
| } |
| |
| fn get_traits_containing_item(&mut self, mut ident: Ident, ns: Namespace) |
| -> Vec<TraitCandidate> { |
| debug!("(getting traits containing item) looking for '{}'", ident.name); |
| |
| let mut found_traits = Vec::new(); |
| // Look for the current trait. |
| if let Some((module, _)) = self.current_trait_ref { |
| if self.resolve_ident_in_module( |
| ModuleOrUniformRoot::Module(module), |
| ident, |
| ns, |
| None, |
| false, |
| module.span, |
| ).is_ok() { |
| let def_id = module.def_id().unwrap(); |
| found_traits.push(TraitCandidate { def_id: def_id, import_ids: smallvec![] }); |
| } |
| } |
| |
| ident.span = ident.span.modern(); |
| let mut search_module = self.current_module; |
| loop { |
| self.get_traits_in_module_containing_item(ident, ns, search_module, &mut found_traits); |
| search_module = unwrap_or!( |
| self.hygienic_lexical_parent(search_module, &mut ident.span), break |
| ); |
| } |
| |
| if let Some(prelude) = self.prelude { |
| if !search_module.no_implicit_prelude { |
| self.get_traits_in_module_containing_item(ident, ns, prelude, &mut found_traits); |
| } |
| } |
| |
| found_traits |
| } |
| |
| fn get_traits_in_module_containing_item(&mut self, |
| ident: Ident, |
| ns: Namespace, |
| module: Module<'a>, |
| found_traits: &mut Vec<TraitCandidate>) { |
| assert!(ns == TypeNS || ns == ValueNS); |
| let mut traits = module.traits.borrow_mut(); |
| if traits.is_none() { |
| let mut collected_traits = Vec::new(); |
| module.for_each_child(|name, ns, binding| { |
| if ns != TypeNS { return } |
| match binding.res() { |
| Res::Def(DefKind::Trait, _) | |
| Res::Def(DefKind::TraitAlias, _) => collected_traits.push((name, binding)), |
| _ => (), |
| } |
| }); |
| *traits = Some(collected_traits.into_boxed_slice()); |
| } |
| |
| for &(trait_name, binding) in traits.as_ref().unwrap().iter() { |
| // Traits have pseudo-modules that can be used to search for the given ident. |
| if let Some(module) = binding.module() { |
| let mut ident = ident; |
| if ident.span.glob_adjust( |
| module.expansion, |
| binding.span, |
| ).is_none() { |
| continue |
| } |
| if self.resolve_ident_in_module_unadjusted( |
| ModuleOrUniformRoot::Module(module), |
| ident, |
| ns, |
| false, |
| module.span, |
| ).is_ok() { |
| let import_ids = self.find_transitive_imports(&binding.kind, trait_name); |
| let trait_def_id = module.def_id().unwrap(); |
| found_traits.push(TraitCandidate { def_id: trait_def_id, import_ids }); |
| } |
| } else if let Res::Def(DefKind::TraitAlias, _) = binding.res() { |
| // For now, just treat all trait aliases as possible candidates, since we don't |
| // know if the ident is somewhere in the transitive bounds. |
| let import_ids = self.find_transitive_imports(&binding.kind, trait_name); |
| let trait_def_id = binding.res().def_id(); |
| found_traits.push(TraitCandidate { def_id: trait_def_id, import_ids }); |
| } else { |
| bug!("candidate is not trait or trait alias?") |
| } |
| } |
| } |
| |
| fn find_transitive_imports(&mut self, mut kind: &NameBindingKind<'_>, |
| trait_name: Ident) -> SmallVec<[NodeId; 1]> { |
| let mut import_ids = smallvec![]; |
| while let NameBindingKind::Import { directive, binding, .. } = kind { |
| self.maybe_unused_trait_imports.insert(directive.id); |
| self.add_to_glob_map(&directive, trait_name); |
| import_ids.push(directive.id); |
| kind = &binding.kind; |
| }; |
| import_ids |
| } |
| |
| fn lookup_import_candidates_from_module<FilterFn>(&mut self, |
| lookup_ident: Ident, |
| namespace: Namespace, |
| start_module: &'a ModuleData<'a>, |
| crate_name: Ident, |
| filter_fn: FilterFn) |
| -> Vec<ImportSuggestion> |
| where FilterFn: Fn(Res) -> bool |
| { |
| let mut candidates = Vec::new(); |
| let mut seen_modules = FxHashSet::default(); |
| let not_local_module = crate_name.name != kw::Crate; |
| let mut worklist = vec![(start_module, Vec::<ast::PathSegment>::new(), not_local_module)]; |
| |
| while let Some((in_module, |
| path_segments, |
| in_module_is_extern)) = worklist.pop() { |
| self.populate_module_if_necessary(in_module); |
| |
| // We have to visit module children in deterministic order to avoid |
| // instabilities in reported imports (#43552). |
| in_module.for_each_child_stable(|ident, ns, name_binding| { |
| // avoid imports entirely |
| if name_binding.is_import() && !name_binding.is_extern_crate() { return; } |
| // avoid non-importable candidates as well |
| if !name_binding.is_importable() { return; } |
| |
| // collect results based on the filter function |
| if ident.name == lookup_ident.name && ns == namespace { |
| let res = name_binding.res(); |
| if filter_fn(res) { |
| // create the path |
| let mut segms = path_segments.clone(); |
| if lookup_ident.span.rust_2018() { |
| // crate-local absolute paths start with `crate::` in edition 2018 |
| // FIXME: may also be stabilized for Rust 2015 (Issues #45477, #44660) |
| segms.insert( |
| 0, ast::PathSegment::from_ident(crate_name) |
| ); |
| } |
| |
| segms.push(ast::PathSegment::from_ident(ident)); |
| let path = Path { |
| span: name_binding.span, |
| segments: segms, |
| }; |
| // the entity is accessible in the following cases: |
| // 1. if it's defined in the same crate, it's always |
| // accessible (since private entities can be made public) |
| // 2. if it's defined in another crate, it's accessible |
| // only if both the module is public and the entity is |
| // declared as public (due to pruning, we don't explore |
| // outside crate private modules => no need to check this) |
| if !in_module_is_extern || name_binding.vis == ty::Visibility::Public { |
| let did = match res { |
| Res::Def(DefKind::Ctor(..), did) => self.parent(did), |
| _ => res.opt_def_id(), |
| }; |
| candidates.push(ImportSuggestion { did, path }); |
| } |
| } |
| } |
| |
| // collect submodules to explore |
| if let Some(module) = name_binding.module() { |
| // form the path |
| let mut path_segments = path_segments.clone(); |
| path_segments.push(ast::PathSegment::from_ident(ident)); |
| |
| let is_extern_crate_that_also_appears_in_prelude = |
| name_binding.is_extern_crate() && |
| lookup_ident.span.rust_2018(); |
| |
| let is_visible_to_user = |
| !in_module_is_extern || name_binding.vis == ty::Visibility::Public; |
| |
| if !is_extern_crate_that_also_appears_in_prelude && is_visible_to_user { |
| // add the module to the lookup |
| let is_extern = in_module_is_extern || name_binding.is_extern_crate(); |
| if seen_modules.insert(module.def_id().unwrap()) { |
| worklist.push((module, path_segments, is_extern)); |
| } |
| } |
| } |
| }) |
| } |
| |
| candidates |
| } |
| |
| /// When name resolution fails, this method can be used to look up candidate |
| /// entities with the expected name. It allows filtering them using the |
| /// supplied predicate (which should be used to only accept the types of |
| /// definitions expected, e.g., traits). The lookup spans across all crates. |
| /// |
| /// N.B., the method does not look into imports, but this is not a problem, |
| /// since we report the definitions (thus, the de-aliased imports). |
| fn lookup_import_candidates<FilterFn>(&mut self, |
| lookup_ident: Ident, |
| namespace: Namespace, |
| filter_fn: FilterFn) |
| -> Vec<ImportSuggestion> |
| where FilterFn: Fn(Res) -> bool |
| { |
| let mut suggestions = self.lookup_import_candidates_from_module( |
| lookup_ident, namespace, self.graph_root, Ident::with_empty_ctxt(kw::Crate), &filter_fn |
| ); |
| |
| if lookup_ident.span.rust_2018() { |
| let extern_prelude_names = self.extern_prelude.clone(); |
| for (ident, _) in extern_prelude_names.into_iter() { |
| if let Some(crate_id) = self.crate_loader.maybe_process_path_extern(ident.name, |
| ident.span) { |
| let crate_root = self.get_module(DefId { |
| krate: crate_id, |
| index: CRATE_DEF_INDEX, |
| }); |
| self.populate_module_if_necessary(&crate_root); |
| |
| suggestions.extend(self.lookup_import_candidates_from_module( |
| lookup_ident, namespace, crate_root, ident, &filter_fn)); |
| } |
| } |
| } |
| |
| suggestions |
| } |
| |
| fn find_module(&mut self, def_id: DefId) -> Option<(Module<'a>, ImportSuggestion)> { |
| let mut result = None; |
| let mut seen_modules = FxHashSet::default(); |
| let mut worklist = vec![(self.graph_root, Vec::new())]; |
| |
| while let Some((in_module, path_segments)) = worklist.pop() { |
| // abort if the module is already found |
| if result.is_some() { break; } |
| |
| self.populate_module_if_necessary(in_module); |
| |
| in_module.for_each_child_stable(|ident, _, name_binding| { |
| // abort if the module is already found or if name_binding is private external |
| if result.is_some() || !name_binding.vis.is_visible_locally() { |
| return |
| } |
| if let Some(module) = name_binding.module() { |
| // form the path |
| let mut path_segments = path_segments.clone(); |
| path_segments.push(ast::PathSegment::from_ident(ident)); |
| let module_def_id = module.def_id().unwrap(); |
| if module_def_id == def_id { |
| let path = Path { |
| span: name_binding.span, |
| segments: path_segments, |
| }; |
| result = Some((module, ImportSuggestion { did: Some(def_id), path })); |
| } else { |
| // add the module to the lookup |
| if seen_modules.insert(module_def_id) { |
| worklist.push((module, path_segments)); |
| } |
| } |
| } |
| }); |
| } |
| |
| result |
| } |
| |
| fn collect_enum_variants(&mut self, def_id: DefId) -> Option<Vec<Path>> { |
| self.find_module(def_id).map(|(enum_module, enum_import_suggestion)| { |
| self.populate_module_if_necessary(enum_module); |
| |
| let mut variants = Vec::new(); |
| enum_module.for_each_child_stable(|ident, _, name_binding| { |
| if let Res::Def(DefKind::Variant, _) = name_binding.res() { |
| let mut segms = enum_import_suggestion.path.segments.clone(); |
| segms.push(ast::PathSegment::from_ident(ident)); |
| variants.push(Path { |
| span: name_binding.span, |
| segments: segms, |
| }); |
| } |
| }); |
| variants |
| }) |
| } |
| |
| 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 resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility { |
| match vis.node { |
| ast::VisibilityKind::Public => ty::Visibility::Public, |
| ast::VisibilityKind::Crate(..) => { |
| ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX)) |
| } |
| ast::VisibilityKind::Inherited => { |
| ty::Visibility::Restricted(self.current_module.normal_ancestor_id) |
| } |
| ast::VisibilityKind::Restricted { ref path, id, .. } => { |
| // For visibilities we are not ready to provide correct implementation of "uniform |
| // paths" right now, so on 2018 edition we only allow module-relative paths for now. |
| // On 2015 edition visibilities are resolved as crate-relative by default, |
| // so we are prepending a root segment if necessary. |
| let ident = path.segments.get(0).expect("empty path in visibility").ident; |
| let crate_root = if ident.is_path_segment_keyword() { |
| None |
| } else if ident.span.rust_2018() { |
| let msg = "relative paths are not supported in visibilities on 2018 edition"; |
| self.session.struct_span_err(ident.span, msg) |
| .span_suggestion( |
| path.span, |
| "try", |
| format!("crate::{}", path), |
| Applicability::MaybeIncorrect, |
| ) |
| .emit(); |
| return ty::Visibility::Public; |
| } else { |
| let ctxt = ident.span.ctxt(); |
| Some(Segment::from_ident(Ident::new( |
| kw::PathRoot, path.span.shrink_to_lo().with_ctxt(ctxt) |
| ))) |
| }; |
| |
| let segments = crate_root.into_iter() |
| .chain(path.segments.iter().map(|seg| seg.into())).collect::<Vec<_>>(); |
| let res = self.smart_resolve_path_fragment( |
| id, |
| None, |
| &segments, |
| path.span, |
| PathSource::Visibility, |
| CrateLint::SimplePath(id), |
| ).base_res(); |
| if res == Res::Err { |
| ty::Visibility::Public |
| } else { |
| let vis = ty::Visibility::Restricted(res.def_id()); |
| if self.is_accessible(vis) { |
| vis |
| } else { |
| self.session.span_err(path.span, "visibilities can only be restricted \ |
| to ancestor modules"); |
| ty::Visibility::Public |
| } |
| } |
| } |
| } |
| } |
| |
| fn is_accessible(&self, vis: ty::Visibility) -> bool { |
| vis.is_accessible_from(self.current_module.normal_ancestor_id, self) |
| } |
| |
| 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 { |
| 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() { b.article() } else { "a" }; |
| format!("{a}{built_in} {thing}{from}", |
| a = article, thing = b.descr(), built_in = built_in, from = from) |
| } else { |
| let introduced = if b.is_import() { "imported" } else { "defined" }; |
| format!("the {thing} {introduced} here", |
| thing = b.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 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 = b.descr(), |
| )) |
| } |
| if misc == AmbiguityErrorMisc::SuggestCrate { |
| help_msgs.push(format!( |
| "use `crate::{ident}` to refer to this {thing} unambiguously", |
| ident = ident, thing = b.descr(), |
| )) |
| } else if misc == AmbiguityErrorMisc::SuggestSelf { |
| help_msgs.push(format!( |
| "use `self::{ident}` to refer to this {thing} unambiguously", |
| ident = ident, thing = b.descr(), |
| )) |
| } |
| |
| 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) { |
| span_err!(self.session, ident.span, E0603, "{} `{}` is private", |
| binding.descr(), ident.name); |
| } |
| } |
| } |
| |
| 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() { |
| 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 }); |
| self.populate_module_if_necessary(&crate_root); |
| Some((crate_root, ty::Visibility::Public, DUMMY_SP, Mark::root()) |
| .to_name_binding(self.arenas)) |
| } |
| }) |
| } |
| } |
| |
| fn is_self_type(path: &[Segment], namespace: Namespace) -> bool { |
| namespace == TypeNS && path.len() == 1 && path[0].ident.name == kw::SelfUpper |
| } |
| |
| fn is_self_value(path: &[Segment], namespace: Namespace) -> bool { |
| namespace == ValueNS && path.len() == 1 && path[0].ident.name == kw::SelfLower |
| } |
| |
| 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<_>>()) |
| } |
| |
| /// Gets the stringified path for an enum from an `ImportSuggestion` for an enum variant. |
| fn import_candidate_to_enum_paths(suggestion: &ImportSuggestion) -> (String, String) { |
| let variant_path = &suggestion.path; |
| let variant_path_string = path_names_to_string(variant_path); |
| |
| let path_len = suggestion.path.segments.len(); |
| let enum_path = ast::Path { |
| span: suggestion.path.span, |
| segments: suggestion.path.segments[0..path_len - 1].to_vec(), |
| }; |
| let enum_path_string = path_names_to_string(&enum_path); |
| |
| (variant_path_string, enum_path_string) |
| } |
| |
| /// When an entity with a given name is not available in scope, we search for |
| /// entities with that name in all crates. This method allows outputting the |
| /// results of this search in a programmer-friendly way |
| fn show_candidates(err: &mut DiagnosticBuilder<'_>, |
| // This is `None` if all placement locations are inside expansions |
| span: Option<Span>, |
| candidates: &[ImportSuggestion], |
| better: bool, |
| found_use: bool) { |
| |
| // we want consistent results across executions, but candidates are produced |
| // by iterating through a hash map, so make sure they are ordered: |
| let mut path_strings: Vec<_> = |
| candidates.into_iter().map(|c| path_names_to_string(&c.path)).collect(); |
| path_strings.sort(); |
| |
| let better = if better { "better " } else { "" }; |
| let msg_diff = match path_strings.len() { |
| 1 => " is found in another module, you can import it", |
| _ => "s are found in other modules, you can import them", |
| }; |
| let msg = format!("possible {}candidate{} into scope", better, msg_diff); |
| |
| if let Some(span) = span { |
| for candidate in &mut path_strings { |
| // produce an additional newline to separate the new use statement |
| // from the directly following item. |
| let additional_newline = if found_use { |
| "" |
| } else { |
| "\n" |
| }; |
| *candidate = format!("use {};\n{}", candidate, additional_newline); |
| } |
| |
| err.span_suggestions( |
| span, |
| &msg, |
| path_strings.into_iter(), |
| Applicability::Unspecified, |
| ); |
| } else { |
| let mut msg = msg; |
| msg.push(':'); |
| for candidate in path_strings { |
| msg.push('\n'); |
| msg.push_str(&candidate); |
| } |
| } |
| } |
| |
| /// 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_empty_ctxt(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), |
| } |
| } |
| } |
| |
| __build_diagnostic_array! { librustc_resolve, DIAGNOSTICS } |