// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png", html_favicon_url = "https://doc.rust-lang.org/favicon.ico", html_root_url = "https://doc.rust-lang.org/nightly/")] #![deny(warnings)] #![feature(rustc_diagnostic_macros)] #[macro_use] extern crate log; #[macro_use] extern crate syntax; extern crate syntax_pos; extern crate rustc_errors as errors; extern crate arena; #[macro_use] extern crate rustc; extern crate rustc_data_structures; use self::Namespace::*; use self::TypeParameters::*; use self::RibKind::*; use rustc::hir::map::{Definitions, DefCollector}; use rustc::hir::{self, PrimTy, TyBool, TyChar, TyFloat, TyInt, TyUint, TyStr}; use rustc::middle::cstore::{CrateStore, CrateLoader}; use rustc::session::Session; use rustc::lint; use rustc::hir::def::*; use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, DefId}; use rustc::ty; use rustc::hir::{Freevar, FreevarMap, TraitCandidate, TraitMap, GlobMap}; use rustc::util::nodemap::{NodeMap, NodeSet, FxHashMap, FxHashSet, DefIdMap}; use syntax::codemap::{dummy_spanned, respan}; use syntax::ext::hygiene::{Mark, MarkKind, SyntaxContext}; use syntax::ast::{self, Name, NodeId, Ident, SpannedIdent, FloatTy, IntTy, UintTy}; use syntax::ext::base::SyntaxExtension; use syntax::ext::base::Determinacy::{self, Determined, Undetermined}; use syntax::ext::base::MacroKind; use syntax::symbol::{Symbol, keywords}; use syntax::util::lev_distance::find_best_match_for_name; use syntax::visit::{self, FnKind, Visitor}; use syntax::attr; use syntax::ast::{Arm, BindingMode, Block, Crate, Expr, ExprKind}; use syntax::ast::{FnDecl, ForeignItem, ForeignItemKind, GenericParam, 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::feature_gate::{feature_err, emit_feature_err, GateIssue}; use syntax::parse::token; use syntax::ptr::P; use syntax_pos::{Span, DUMMY_SP, MultiSpan}; use errors::{DiagnosticBuilder, DiagnosticId}; use std::cell::{Cell, RefCell}; use std::cmp; use std::collections::BTreeSet; use std::fmt; use std::iter; use std::mem::replace; use rustc_data_structures::sync::Lrc; use resolve_imports::{ImportDirective, ImportDirectiveSubclass, NameResolution, ImportResolver}; use macros::{InvocationData, LegacyBinding, LegacyScope, MacroBinding}; // NB: This module needs to be declared first so diagnostics are // registered before they are used. mod diagnostics; mod macros; mod check_unused; mod build_reduced_graph; mod resolve_imports; /// A free importable items suggested in case of resolution failure. struct ImportSuggestion { 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, target: BTreeSet, } impl PartialOrd for BindingError { fn partial_cmp(&self, other: &BindingError) -> Option { Some(self.cmp(other)) } } impl PartialEq for BindingError { fn eq(&self, other: &BindingError) -> bool { self.name == other.name } } impl Ord for BindingError { fn cmp(&self, other: &BindingError) -> cmp::Ordering { self.name.cmp(&other.name) } } enum ResolutionError<'a> { /// error E0401: can't use type parameters from outer function TypeParametersFromOuterFunction, /// error E0403: the name is already used for a type parameter in this type parameter list NameAlreadyUsedInTypeParameterList(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), /// 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 E0432: unresolved import UnresolvedImport(Option<(Span, &'a str, &'a str)>), /// error E0433: failed to resolve FailedToResolve(&'a str), /// 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 Ys BindingShadowsSomethingUnacceptable(&'a str, Name, &'a NameBinding<'a>), /// error E0128: type parameters with a default cannot use forward declared identifiers ForwardDeclaredTyParam, } 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::TypeParametersFromOuterFunction => { let mut err = struct_span_err!(resolver.session, span, E0401, "can't use type parameters from outer function; \ try using a local type parameter instead"); err.span_label(span, "use of type variable from outer function"); err } ResolutionError::NameAlreadyUsedInTypeParameterList(name, first_use_span) => { let mut err = struct_span_err!(resolver.session, span, E0403, "the name `{}` is already used for a type parameter \ in this type parameter list", 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().map(|x| *x).collect::>(); 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().map(|x| *x).collect::>(); 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_label(span, format!("did you mean `{}`?", lev_candidate)); } 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::UnresolvedImport(name) => { let (span, msg) = match name { Some((sp, n, _)) => (sp, format!("unresolved import `{}`", n)), None => (span, "unresolved import".to_owned()), }; let mut err = struct_span_err!(resolver.session, span, E0432, "{}", msg); if let Some((_, _, p)) = name { err.span_label(span, p); } err } ResolutionError::FailedToResolve(msg) => { let mut err = struct_span_err!(resolver.session, span, E0433, "failed to resolve. {}", msg); err.span_label(span, msg); 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 = PathResolution::new(binding.def()).kind_name(); 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 a {}", shadows_what)); let participle = if binding.is_import() { "imported" } else { "defined" }; let msg = format!("a {} `{}` 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, format!("defaulted type parameters cannot be forward declared")); err } } } #[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; #[derive(Copy, Clone, PartialEq, Eq, Debug)] enum PatternSource { Match, IfLet, WhileLet, Let, For, FnParam, } impl PatternSource { fn descr(self) -> &'static str { match self { PatternSource::Match => "match binding", PatternSource::IfLet => "if let binding", PatternSource::WhileLet => "while let 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, PartialEq, Eq, 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 `::B::C`. TraitItem(Namespace), // Path in `pub(path)` Visibility, // Path in `use a::b::{...};` ImportPrefix, } impl<'a> PathSource<'a> { fn namespace(self) -> Namespace { match self { PathSource::Type | PathSource::Trait(_) | PathSource::Struct | PathSource::Visibility | PathSource::ImportPrefix => TypeNS, PathSource::Expr(..) | PathSource::Pat | PathSource::TupleStruct => ValueNS, PathSource::TraitItem(ns) => ns, } } fn global_by_default(self) -> bool { match self { PathSource::Visibility | PathSource::ImportPrefix => 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 | PathSource::ImportPrefix => 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::ImportPrefix => "module or enum", 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 `Def::Fn`, // this is not precise but usually more helpful than just "value". Some(&ExprKind::Call(..)) => "function", _ => "value", }, } } fn is_expected(self, def: Def) -> bool { match self { PathSource::Type => match def { Def::Struct(..) | Def::Union(..) | Def::Enum(..) | Def::Trait(..) | Def::TyAlias(..) | Def::AssociatedTy(..) | Def::PrimTy(..) | Def::TyParam(..) | Def::SelfTy(..) | Def::TyForeign(..) => true, _ => false, }, PathSource::Trait(AliasPossibility::No) => match def { Def::Trait(..) => true, _ => false, }, PathSource::Trait(AliasPossibility::Maybe) => match def { Def::Trait(..) => true, Def::TraitAlias(..) => true, _ => false, }, PathSource::Expr(..) => match def { Def::StructCtor(_, CtorKind::Const) | Def::StructCtor(_, CtorKind::Fn) | Def::VariantCtor(_, CtorKind::Const) | Def::VariantCtor(_, CtorKind::Fn) | Def::Const(..) | Def::Static(..) | Def::Local(..) | Def::Upvar(..) | Def::Fn(..) | Def::Method(..) | Def::AssociatedConst(..) => true, _ => false, }, PathSource::Pat => match def { Def::StructCtor(_, CtorKind::Const) | Def::VariantCtor(_, CtorKind::Const) | Def::Const(..) | Def::AssociatedConst(..) => true, _ => false, }, PathSource::TupleStruct => match def { Def::StructCtor(_, CtorKind::Fn) | Def::VariantCtor(_, CtorKind::Fn) => true, _ => false, }, PathSource::Struct => match def { Def::Struct(..) | Def::Union(..) | Def::Variant(..) | Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) => true, _ => false, }, PathSource::TraitItem(ns) => match def { Def::AssociatedConst(..) | Def::Method(..) if ns == ValueNS => true, Def::AssociatedTy(..) if ns == TypeNS => true, _ => false, }, PathSource::ImportPrefix => match def { Def::Mod(..) | Def::Enum(..) => true, _ => false, }, PathSource::Visibility => match def { Def::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) | (PathSource::ImportPrefix, true) => "E0577", (PathSource::Visibility, false) | (PathSource::ImportPrefix, false) => "E0578", } } } #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)] pub enum Namespace { TypeNS, ValueNS, MacroNS, } #[derive(Clone, Default, Debug)] pub struct PerNS { value_ns: T, type_ns: T, macro_ns: Option, } impl ::std::ops::Index for PerNS { type Output = T; fn index(&self, ns: Namespace) -> &T { match ns { ValueNS => &self.value_ns, TypeNS => &self.type_ns, MacroNS => self.macro_ns.as_ref().unwrap(), } } } impl ::std::ops::IndexMut for PerNS { fn index_mut(&mut self, ns: Namespace) -> &mut T { match ns { ValueNS => &mut self.value_ns, TypeNS => &mut self.type_ns, MacroNS => self.macro_ns.as_mut().unwrap(), } } } struct UsePlacementFinder { target_module: NodeId, span: Option, found_use: bool, } impl UsePlacementFinder { fn check(krate: &Crate, target_module: NodeId) -> (Option, 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.with_hi(item.span.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.with_hi(item.span.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.with_hi(attr.span.lo())); } } } } }, } } } } 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_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 = keywords::SelfType.ident(); let def = self.resolve_ident_in_lexical_scope(self_ty, TypeNS, true, ty.span) .map_or(Def::Err, |d| d.def()); self.record_def(ty.id, PathResolution::new(def)); } TyKind::Array(ref element, ref length) => { self.visit_ty(element); self.with_constant_rib(|this| { this.visit_expr(length); }); return; } _ => (), } 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_variant(&mut self, variant: &'tcx ast::Variant, generics: &'tcx Generics, item_id: ast::NodeId) { if let Some(ref dis_expr) = variant.node.disr_expr { // resolve the discriminator expr as a constant self.with_constant_rib(|this| { this.visit_expr(dis_expr); }); } // `visit::walk_variant` without the discriminant expression. self.visit_variant_data(&variant.node.data, variant.node.name, generics, item_id, variant.span); } fn visit_foreign_item(&mut self, foreign_item: &'tcx ForeignItem) { let type_parameters = match foreign_item.node { ForeignItemKind::Fn(_, ref generics) => { HasTypeParameters(generics, ItemRibKind) } ForeignItemKind::Static(..) => NoTypeParameters, ForeignItemKind::Ty => NoTypeParameters, }; self.with_type_parameter_rib(type_parameters, |this| { visit::walk_foreign_item(this, foreign_item); }); } fn visit_fn(&mut self, function_kind: FnKind<'tcx>, declaration: &'tcx FnDecl, _: Span, node_id: NodeId) { let rib_kind = match function_kind { FnKind::ItemFn(..) => { ItemRibKind } FnKind::Method(_, _, _, _) => { TraitOrImplItemRibKind } FnKind::Closure(_) => ClosureRibKind(node_id), }; // 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(); 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. 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 Substs can only // provide previous type parameters as they're built. let mut default_ban_rib = Rib::new(ForwardTyParamBanRibKind); default_ban_rib.bindings.extend(generics.params.iter() .filter_map(|p| if let GenericParam::Type(ref tp) = *p { Some(tp) } else { None }) .skip_while(|p| p.default.is_none()) .map(|p| (Ident::with_empty_ctxt(p.ident.name), Def::Err))); for param in &generics.params { match *param { GenericParam::Lifetime(_) => self.visit_generic_param(param), GenericParam::Type(ref ty_param) => { for bound in &ty_param.bounds { self.visit_ty_param_bound(bound); } if let Some(ref ty) = ty_param.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(ty_param.ident.name)); } } } for p in &generics.where_clause.predicates { self.visit_where_predicate(p); } } } #[derive(Copy, Clone)] enum TypeParameters<'a, 'b> { NoTypeParameters, HasTypeParameters(// Type parameters. &'b Generics, // The kind of the rib used for type parameters. RibKind<'a>), } // The rib kind controls the translation of local // definitions (`Def::Local`) to upvars (`Def::Upvar`). #[derive(Copy, Clone, Debug)] enum RibKind<'a> { // No translation needs to be applied. NormalRibKind, // We passed through a closure scope at the given node ID. // Translate upvars as appropriate. ClosureRibKind(NodeId /* func id */), // 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). TraitOrImplItemRibKind, // 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, } /// One local scope. #[derive(Debug)] struct Rib<'a> { bindings: FxHashMap, kind: RibKind<'a>, } impl<'a> Rib<'a> { fn new(kind: RibKind<'a>) -> Rib<'a> { Rib { bindings: FxHashMap(), kind, } } } enum LexicalScopeBinding<'a> { Item(&'a NameBinding<'a>), Def(Def), } impl<'a> LexicalScopeBinding<'a> { fn item(self) -> Option<&'a NameBinding<'a>> { match self { LexicalScopeBinding::Item(binding) => Some(binding), _ => None, } } fn def(self) -> Def { match self { LexicalScopeBinding::Item(binding) => binding.def(), LexicalScopeBinding::Def(def) => def, } } } #[derive(Clone, Debug)] enum PathResult<'a> { Module(Module<'a>), NonModule(PathResolution), Indeterminate, Failed(Span, String, bool /* is the error from the last segment? */), } enum ModuleKind { Block(NodeId), Def(Def, Name), } /// One node in the tree of modules. pub struct ModuleData<'a> { parent: Option>, kind: ModuleKind, // The def id of the closest normal module (`mod`) ancestor (including this module). normal_ancestor_id: DefId, resolutions: RefCell>>>, legacy_macro_resolutions: RefCell>, macro_resolutions: RefCell, Span)>>, // Macro invocations that can expand into items in this module. unresolved_invocations: RefCell>, no_implicit_prelude: bool, glob_importers: RefCell>>, globs: RefCell>>, // Used to memoize the traits in this module for faster searches through all traits in scope. traits: RefCell)]>>>, // 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, /// 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>, kind: ModuleKind, normal_ancestor_id: DefId, expansion: Mark, span: Span) -> Self { ModuleData { parent, kind, normal_ancestor_id, resolutions: RefCell::new(FxHashMap()), legacy_macro_resolutions: RefCell::new(Vec::new()), macro_resolutions: RefCell::new(Vec::new()), unresolved_invocations: RefCell::new(FxHashSet()), 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)>(&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)>(&self, mut f: F) { let resolutions = self.resolutions.borrow(); let mut resolutions = resolutions.iter().map(|(&(ident, ns), &resolution)| { // Pre-compute keys for sorting (ident.name.as_str(), ns, ident, resolution) }) .collect::>(); resolutions.sort_unstable_by_key(|&(str, ns, ..)| (str, ns)); for &(_, ns, ident, resolution) in resolutions.iter() { resolution.borrow().binding.map(|binding| f(ident, ns, binding)); } } fn def(&self) -> Option { match self.kind { ModuleKind::Def(def, _) => Some(def), _ => None, } } fn def_id(&self) -> Option { self.def().as_ref().map(Def::def_id) } // `self` resolves to the first module ancestor that `is_normal`. fn is_normal(&self) -> bool { match self.kind { ModuleKind::Def(Def::Mod(_), _) => true, _ => false, } } fn is_trait(&self) -> bool { match self.kind { ModuleKind::Def(Def::Trait(_), _) => true, _ => false, } } fn is_local(&self) -> bool { self.normal_ancestor_id.is_local() } fn nearest_item_scope(&'a self) -> Module<'a> { if self.is_trait() { self.parent.unwrap() } else { self } } } impl<'a> fmt::Debug for ModuleData<'a> { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "{:?}", self.def()) } } // Records a possibly-private value, type, or module definition. #[derive(Clone, Debug)] pub struct NameBinding<'a> { kind: NameBindingKind<'a>, 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> { Def(Def), Module(Module<'a>), Import { binding: &'a NameBinding<'a>, directive: &'a ImportDirective<'a>, used: Cell, legacy_self_import: bool, }, Ambiguity { b1: &'a NameBinding<'a>, b2: &'a NameBinding<'a>, legacy: bool, } } struct PrivacyError<'a>(Span, Name, &'a NameBinding<'a>); struct UseError<'a> { err: DiagnosticBuilder<'a>, /// Attach `use` statements for these candidates candidates: Vec, /// The node id of the module to place the use statements in node_id: NodeId, /// Whether the diagnostic should state that it's "better" better: bool, } struct AmbiguityError<'a> { span: Span, name: Name, lexical: bool, b1: &'a NameBinding<'a>, b2: &'a NameBinding<'a>, legacy: bool, } impl<'a> NameBinding<'a> { fn module(&self) -> Option> { match self.kind { NameBindingKind::Module(module) => Some(module), NameBindingKind::Import { binding, .. } => binding.module(), NameBindingKind::Ambiguity { legacy: true, b1, .. } => b1.module(), _ => None, } } fn def(&self) -> Def { match self.kind { NameBindingKind::Def(def) => def, NameBindingKind::Module(module) => module.def().unwrap(), NameBindingKind::Import { binding, .. } => binding.def(), NameBindingKind::Ambiguity { legacy: true, b1, .. } => b1.def(), NameBindingKind::Ambiguity { .. } => Def::Err, } } fn def_ignoring_ambiguity(&self) -> Def { match self.kind { NameBindingKind::Import { binding, .. } => binding.def_ignoring_ambiguity(), NameBindingKind::Ambiguity { b1, .. } => b1.def_ignoring_ambiguity(), _ => self.def(), } } fn get_macro(&self, resolver: &mut Resolver<'a>) -> Lrc { resolver.get_macro(self.def_ignoring_ambiguity()) } // We sometimes need to treat variants as `pub` for backwards compatibility fn pseudo_vis(&self) -> ty::Visibility { if self.is_variant() && self.def().def_id().is_local() { ty::Visibility::Public } else { self.vis } } fn is_variant(&self) -> bool { match self.kind { NameBindingKind::Def(Def::Variant(..)) | NameBindingKind::Def(Def::VariantCtor(..)) => true, _ => false, } } fn is_extern_crate(&self) -> bool { match self.kind { NameBindingKind::Import { directive: &ImportDirective { subclass: ImportDirectiveSubclass::ExternCrate(_), .. }, .. } => true, _ => false, } } fn is_import(&self) -> bool { match self.kind { NameBindingKind::Import { .. } => true, _ => false, } } fn is_renamed_extern_crate(&self) -> bool { if let NameBindingKind::Import { directive, ..} = self.kind { if let ImportDirectiveSubclass::ExternCrate(Some(_)) = directive.subclass { return true; } } false } fn is_glob_import(&self) -> bool { match self.kind { NameBindingKind::Import { directive, .. } => directive.is_glob(), NameBindingKind::Ambiguity { b1, .. } => b1.is_glob_import(), _ => false, } } fn is_importable(&self) -> bool { match self.def() { Def::AssociatedConst(..) | Def::Method(..) | Def::AssociatedTy(..) => false, _ => true, } } fn is_macro_def(&self) -> bool { match self.kind { NameBindingKind::Def(Def::Macro(..)) => true, _ => false, } } fn descr(&self) -> &'static str { if self.is_extern_crate() { "extern crate" } else { self.def().kind_name() } } } /// Interns the names of the primitive types. struct PrimitiveTypeTable { primitive_types: FxHashMap, } impl PrimitiveTypeTable { fn new() -> PrimitiveTypeTable { let mut table = PrimitiveTypeTable { primitive_types: FxHashMap() }; table.intern("bool", TyBool); table.intern("char", TyChar); table.intern("f32", TyFloat(FloatTy::F32)); table.intern("f64", TyFloat(FloatTy::F64)); table.intern("isize", TyInt(IntTy::Isize)); table.intern("i8", TyInt(IntTy::I8)); table.intern("i16", TyInt(IntTy::I16)); table.intern("i32", TyInt(IntTy::I32)); table.intern("i64", TyInt(IntTy::I64)); table.intern("i128", TyInt(IntTy::I128)); table.intern("str", TyStr); table.intern("usize", TyUint(UintTy::Usize)); table.intern("u8", TyUint(UintTy::U8)); table.intern("u16", TyUint(UintTy::U16)); table.intern("u32", TyUint(UintTy::U32)); table.intern("u64", TyUint(UintTy::U64)); table.intern("u128", TyUint(UintTy::U128)); table } fn intern(&mut self, string: &str, primitive_type: PrimTy) { self.primitive_types.insert(Symbol::intern(string), primitive_type); } } /// The main resolver class. pub struct Resolver<'a> { session: &'a Session, cstore: &'a CrateStore, pub definitions: Definitions, graph_root: Module<'a>, prelude: Option>, // n.b. This is used only for better diagnostics, not name resolution itself. has_self: FxHashSet, // Names of fields of an item `DefId` accessible with dot syntax. // Used for hints during error reporting. field_names: FxHashMap>, // 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>>, // The current set of local scopes, for labels. label_ribs: Vec>, // 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, // The idents for the primitive types. primitive_type_table: PrimitiveTypeTable, def_map: DefMap, pub freevars: FreevarMap, freevars_seen: NodeMap>, pub export_map: ExportMap, 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_map: FxHashMap>, extern_module_map: FxHashMap<(DefId, bool /* MacrosOnly? */), Module<'a>>, pub make_glob_map: bool, /// Maps imports to the names of items actually imported (this actually maps /// all imports, but only glob imports are actually interesting). pub glob_map: GlobMap, used_imports: FxHashSet<(NodeId, Namespace)>, pub maybe_unused_trait_imports: NodeSet, pub maybe_unused_extern_crates: Vec<(NodeId, Span)>, /// privacy errors are delayed until the end in order to deduplicate them privacy_errors: Vec>, /// ambiguity errors are delayed for deduplication ambiguity_errors: Vec>, /// `use` injections are delayed for better placement and deduplication use_injections: Vec>, /// `use` injections for proc macros wrongly imported with #[macro_use] proc_mac_errors: Vec, gated_errors: FxHashSet, disallowed_shadowing: Vec<&'a LegacyBinding<'a>>, arenas: &'a ResolverArenas<'a>, dummy_binding: &'a NameBinding<'a>, use_extern_macros: bool, // true if `#![feature(use_extern_macros)]` crate_loader: &'a mut CrateLoader, macro_names: FxHashSet, global_macros: FxHashMap>, pub all_macros: FxHashMap, lexical_macro_resolutions: Vec<(Ident, &'a Cell>)>, macro_map: FxHashMap>, macro_defs: FxHashMap, local_macro_def_scopes: FxHashMap>, macro_exports: Vec, pub whitelisted_legacy_custom_derives: Vec, pub found_unresolved_macro: bool, // 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, // Maps the `Mark` of an expansion to its containing module or block. invocations: FxHashMap>, // Avoid duplicated errors for "name already defined". name_already_seen: FxHashMap, // If `#![feature(proc_macro)]` is set proc_macro_enabled: bool, // A set of procedural macros imported by `#[macro_use]` that have already been warned about warned_proc_macros: FxHashSet, potentially_unused_imports: Vec<&'a ImportDirective<'a>>, // This table maps struct IDs into struct constructor IDs, // it's not used during normal resolution, only for better error reporting. struct_constructors: DefIdMap<(Def, ty::Visibility)>, // Only used for better errors on `fn(): fn()` current_type_ascription: Vec, injected_crate: Option>, } pub struct ResolverArenas<'a> { modules: arena::TypedArena>, local_modules: RefCell>>, name_bindings: arena::TypedArena>, import_directives: arena::TypedArena>, name_resolutions: arena::TypedArena>>, invocation_data: arena::TypedArena>, legacy_bindings: arena::TypedArena>, } 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>> { 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> { 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: 'a> ty::DefIdTree for &'a Resolver<'b> { fn parent(self, id: DefId) -> Option { match id.krate { LOCAL_CRATE => self.definitions.def_key(id.index).parent, _ => self.cstore.def_key(id).parent, }.map(|index| DefId { index: index, ..id }) } } impl<'a> hir::lowering::Resolver for Resolver<'a> { fn resolve_hir_path(&mut self, path: &mut hir::Path, is_value: bool) { 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<&str>, components: &[&str], is_value: bool) -> hir::Path { let mut path = hir::Path { span, def: Def::Err, segments: iter::once(keywords::CrateRoot.name()).chain({ crate_root.into_iter().chain(components.iter().cloned()).map(Symbol::intern) }).map(hir::PathSegment::from_name).collect(), }; self.resolve_hir_path(&mut path, is_value); path } fn get_resolution(&mut self, id: NodeId) -> Option { self.def_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 { use std::iter; let mut errored = false; let mut path = if path_str.starts_with("::") { hir::Path { span, def: Def::Err, segments: iter::once(keywords::CrateRoot.name()).chain({ path_str.split("::").skip(1).map(Symbol::intern) }).map(hir::PathSegment::from_name).collect(), } } else { hir::Path { span, def: Def::Err, segments: path_str.split("::").map(Symbol::intern) .map(hir::PathSegment::from_name).collect(), } }; self.resolve_hir_path_cb(&mut path, is_value, |_, _, _| errored = true); if errored || path.def == Def::Err { Err(()) } else { Ok(path) } } /// resolve_hir_path, but takes a callback in case there was an error fn resolve_hir_path_cb(&mut self, path: &mut hir::Path, is_value: bool, error_callback: F) where F: for<'c, 'b> FnOnce(&'c mut Resolver, Span, ResolutionError<'b>) { let namespace = if is_value { ValueNS } else { TypeNS }; let hir::Path { ref segments, span, ref mut def } = *path; let path: Vec = segments.iter() .map(|seg| respan(span, Ident::with_empty_ctxt(seg.name))) .collect(); match self.resolve_path(&path, Some(namespace), true, span) { PathResult::Module(module) => *def = module.def().unwrap(), PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 => *def = path_res.base_def(), PathResult::NonModule(..) => match self.resolve_path(&path, None, true, span) { PathResult::Failed(span, msg, _) => { error_callback(self, span, ResolutionError::FailedToResolve(&msg)); } _ => {} }, PathResult::Indeterminate => unreachable!(), PathResult::Failed(span, msg, _) => { error_callback(self, span, ResolutionError::FailedToResolve(&msg)); } } } } impl<'a> Resolver<'a> { pub fn new(session: &'a Session, cstore: &'a CrateStore, krate: &Crate, crate_name: &str, make_glob_map: MakeGlobMap, crate_loader: &'a mut CrateLoader, arenas: &'a ResolverArenas<'a>) -> Resolver<'a> { let root_def_id = DefId::local(CRATE_DEF_INDEX); let root_module_kind = ModuleKind::Def(Def::Mod(root_def_id), keywords::Invalid.name()); let graph_root = arenas.alloc_module(ModuleData { no_implicit_prelude: attr::contains_name(&krate.attrs, "no_implicit_prelude"), ..ModuleData::new(None, root_module_kind, root_def_id, Mark::root(), krate.span) }); let mut module_map = FxHashMap(); module_map.insert(DefId::local(CRATE_DEF_INDEX), graph_root); let mut definitions = Definitions::new(); DefCollector::new(&mut definitions, Mark::root()) .collect_root(crate_name, session.local_crate_disambiguator()); let mut invocations = FxHashMap(); invocations.insert(Mark::root(), arenas.alloc_invocation_data(InvocationData::root(graph_root))); let features = session.features_untracked(); let mut macro_defs = FxHashMap(); macro_defs.insert(Mark::root(), root_def_id); Resolver { session, cstore, definitions, // The outermost module has def ID 0; this is not reflected in the // AST. graph_root, prelude: None, has_self: FxHashSet(), field_names: FxHashMap(), 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: Some(vec![Rib::new(ModuleRibKind(graph_root))]), }, label_ribs: Vec::new(), current_trait_ref: None, current_self_type: None, primitive_type_table: PrimitiveTypeTable::new(), def_map: NodeMap(), freevars: NodeMap(), freevars_seen: NodeMap(), export_map: FxHashMap(), trait_map: NodeMap(), module_map, block_map: NodeMap(), extern_module_map: FxHashMap(), make_glob_map: make_glob_map == MakeGlobMap::Yes, glob_map: NodeMap(), used_imports: FxHashSet(), maybe_unused_trait_imports: NodeSet(), maybe_unused_extern_crates: Vec::new(), privacy_errors: Vec::new(), ambiguity_errors: Vec::new(), use_injections: Vec::new(), proc_mac_errors: Vec::new(), gated_errors: FxHashSet(), disallowed_shadowing: Vec::new(), arenas, dummy_binding: arenas.alloc_name_binding(NameBinding { kind: NameBindingKind::Def(Def::Err), expansion: Mark::root(), span: DUMMY_SP, vis: ty::Visibility::Public, }), // The `proc_macro` and `decl_macro` features imply `use_extern_macros` use_extern_macros: features.use_extern_macros || features.proc_macro || features.decl_macro, crate_loader, macro_names: FxHashSet(), global_macros: FxHashMap(), all_macros: FxHashMap(), lexical_macro_resolutions: Vec::new(), macro_map: FxHashMap(), macro_exports: Vec::new(), invocations, macro_defs, local_macro_def_scopes: FxHashMap(), name_already_seen: FxHashMap(), whitelisted_legacy_custom_derives: Vec::new(), proc_macro_enabled: features.proc_macro, warned_proc_macros: FxHashSet(), potentially_unused_imports: Vec::new(), struct_constructors: DefIdMap(), found_unresolved_macro: false, unused_macros: FxHashSet(), current_type_ascription: Vec::new(), injected_crate: None, } } pub fn arenas() -> ResolverArenas<'a> { ResolverArenas { modules: arena::TypedArena::new(), local_modules: RefCell::new(Vec::new()), name_bindings: arena::TypedArena::new(), import_directives: arena::TypedArena::new(), name_resolutions: arena::TypedArena::new(), invocation_data: arena::TypedArena::new(), legacy_bindings: arena::TypedArena::new(), } } fn per_ns T>(&mut self, mut f: F) -> PerNS { PerNS { type_ns: f(self, TypeNS), value_ns: f(self, ValueNS), macro_ns: match self.use_extern_macros { true => Some(f(self, MacroNS)), false => None, }, } } 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, binding: &'a NameBinding<'a>, span: Span) -> bool /* true if an error was reported */ { match binding.kind { NameBindingKind::Import { directive, binding, ref used, legacy_self_import } if !used.get() => { used.set(true); directive.used.set(true); if legacy_self_import { self.warn_legacy_self_import(directive); return false; } self.used_imports.insert((directive.id, ns)); self.add_to_glob_map(directive.id, ident); self.record_use(ident, ns, binding, span) } NameBindingKind::Import { .. } => false, NameBindingKind::Ambiguity { b1, b2, legacy } => { self.ambiguity_errors.push(AmbiguityError { span: span, name: ident.name, lexical: false, b1: b1, b2: b2, legacy, }); if legacy { self.record_use(ident, ns, b1, span); } !legacy } _ => false } } fn add_to_glob_map(&mut self, id: NodeId, ident: Ident) { if self.make_glob_map { self.glob_map.entry(id).or_insert_with(FxHashSet).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: bool, path_span: Span) -> Option> { if ns == TypeNS { ident.ctxt = if ident.name == keywords::SelfType.name() { SyntaxContext::empty() // FIXME(jseyfried) improve `Self` hygiene } else { ident.ctxt.modern() } } // Walk backwards up the ribs in scope. let mut module = self.graph_root; for i in (0 .. self.ribs[ns].len()).rev() { if let Some(def) = self.ribs[ns][i].bindings.get(&ident).cloned() { // The ident resolves to a type parameter or local variable. return Some(LexicalScopeBinding::Def( self.adjust_local_def(ns, i, def, record_used, path_span) )); } module = match self.ribs[ns][i].kind { ModuleRibKind(module) => module, MacroDefinition(def) if def == self.macro_def(ident.ctxt) => { // If an invocation of this macro created `ident`, give up on `ident` // and switch to `ident`'s source from the macro definition. ident.ctxt.remove_mark(); continue } _ => continue, }; let item = self.resolve_ident_in_module_unadjusted( module, ident, ns, false, 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.ctxt = ident.ctxt.modern(); loop { module = unwrap_or!(self.hygienic_lexical_parent(module, &mut ident.ctxt), 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( module, ident, ns, false, record_used, path_span, ); self.current_module = orig_current_module; match result { Ok(binding) => return Some(LexicalScopeBinding::Item(binding)), Err(Undetermined) => return None, Err(Determined) => {} } } match self.prelude { Some(prelude) if !module.no_implicit_prelude => { self.resolve_ident_in_module_unadjusted(prelude, ident, ns, false, false, path_span) .ok().map(LexicalScopeBinding::Item) } _ => None, } } fn hygienic_lexical_parent(&mut self, mut module: Module<'a>, ctxt: &mut SyntaxContext) -> Option> { if !module.expansion.is_descendant_of(ctxt.outer()) { return Some(self.macro_def_scope(ctxt.remove_mark())); } if let ModuleKind::Block(..) = module.kind { return Some(module.parent.unwrap()); } let mut module_expansion = module.expansion.modern(); // for backward compatibility while let Some(parent) = module.parent { let parent_expansion = parent.expansion.modern(); if module_expansion.is_descendant_of(parent_expansion) && parent_expansion != module_expansion { return if parent_expansion.is_descendant_of(ctxt.outer()) { Some(parent) } else { None }; } module = parent; module_expansion = parent_expansion; } None } fn resolve_ident_in_module(&mut self, module: Module<'a>, mut ident: Ident, ns: Namespace, ignore_unresolved_invocations: bool, record_used: bool, span: Span) -> Result<&'a NameBinding<'a>, Determinacy> { ident.ctxt = ident.ctxt.modern(); let orig_current_module = self.current_module; if let Some(def) = ident.ctxt.adjust(module.expansion) { self.current_module = self.macro_def_scope(def); } let result = self.resolve_ident_in_module_unadjusted( module, ident, ns, ignore_unresolved_invocations, record_used, span, ); self.current_module = orig_current_module; result } fn resolve_crate_root(&mut self, mut ctxt: SyntaxContext, legacy: bool) -> Module<'a> { let mark = if legacy { // 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. ctxt.marks().into_iter().find(|&mark| mark.kind() != MarkKind::Modern) } 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(&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(&self, mut ident: Ident, pred: P) -> Option where P: Fn(&Rib, Ident) -> Option { 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.ctxt) { ident.ctxt.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_item(&mut self, item: &Item) { let name = item.ident.name; debug!("(resolving item) resolving {}", name); self.check_proc_macro_attrs(&item.attrs); match item.node { ItemKind::Enum(_, ref generics) | ItemKind::Ty(_, ref generics) | ItemKind::Struct(_, ref generics) | ItemKind::Union(_, ref generics) | ItemKind::Fn(.., ref generics, _) => { self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| visit::walk_item(this, item)); } 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_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| { let local_def_id = this.definitions.local_def_id(item.id); this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| { this.visit_generics(generics); walk_list!(this, visit_ty_param_bound, bounds); for trait_item in trait_items { this.check_proc_macro_attrs(&trait_item.attrs); let type_parameters = HasTypeParameters(&trait_item.generics, TraitOrImplItemRibKind); this.with_type_parameter_rib(type_parameters, |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_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| { let local_def_id = this.definitions.local_def_id(item.id); this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| { this.visit_generics(generics); walk_list!(this, visit_ty_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) => { self.with_item_rib(|this| { this.visit_ty(ty); this.with_constant_rib(|this| { this.visit_expr(expr); }); }); } ItemKind::Use(ref use_tree) => { let path = Path { segments: vec![], span: use_tree.span, }; self.resolve_use_tree(item.id, use_tree, &path); } ItemKind::ExternCrate(_) | ItemKind::MacroDef(..) | ItemKind::GlobalAsm(_) => { // do nothing, these are just around to be encoded } ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"), } } fn resolve_use_tree(&mut self, id: NodeId, use_tree: &ast::UseTree, prefix: &Path) { match use_tree.kind { ast::UseTreeKind::Nested(ref items) => { let path = Path { segments: prefix.segments .iter() .chain(use_tree.prefix.segments.iter()) .cloned() .collect(), span: prefix.span.to(use_tree.prefix.span), }; if items.len() == 0 { // Resolve prefix of an import with empty braces (issue #28388). self.smart_resolve_path(id, None, &path, PathSource::ImportPrefix); } else { for &(ref tree, nested_id) in items { self.resolve_use_tree(nested_id, tree, &path); } } } ast::UseTreeKind::Simple(_) => {}, ast::UseTreeKind::Glob => {}, } } fn with_type_parameter_rib<'b, F>(&'b mut self, type_parameters: TypeParameters<'a, 'b>, f: F) where F: FnOnce(&mut Resolver) { match type_parameters { HasTypeParameters(generics, rib_kind) => { let mut function_type_rib = Rib::new(rib_kind); let mut seen_bindings = FxHashMap(); for param in &generics.params { if let GenericParam::Type(ref type_parameter) = *param { let ident = type_parameter.ident.modern(); debug!("with_type_parameter_rib: {}", type_parameter.id); if seen_bindings.contains_key(&ident) { let span = seen_bindings.get(&ident).unwrap(); let err = ResolutionError::NameAlreadyUsedInTypeParameterList( ident.name, span, ); resolve_error(self, type_parameter.span, err); } seen_bindings.entry(ident).or_insert(type_parameter.span); // plain insert (no renaming) let def_id = self.definitions.local_def_id(type_parameter.id); let def = Def::TyParam(def_id); function_type_rib.bindings.insert(ident, def); self.record_def(type_parameter.id, PathResolution::new(def)); } } self.ribs[TypeNS].push(function_type_rib); } NoTypeParameters => { // Nothing to do. } } f(self); if let HasTypeParameters(..) = type_parameters { self.ribs[TypeNS].pop(); } } fn with_label_rib(&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(&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(&mut self, f: F) where F: FnOnce(&mut Resolver) { self.ribs[ValueNS].push(Rib::new(ConstantItemRibKind)); f(self); self.ribs[ValueNS].pop(); } fn with_current_self_type(&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 } /// This is called to resolve a trait reference from an `impl` (i.e. `impl Trait for Foo`) fn with_optional_trait_ref(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T where F: FnOnce(&mut Resolver, Option) -> T { let mut new_val = None; let mut new_id = None; if let Some(trait_ref) = opt_trait_ref { let path: Vec<_> = trait_ref.path.segments.iter() .map(|seg| respan(seg.span, seg.identifier)) .collect(); let def = self.smart_resolve_path_fragment( trait_ref.ref_id, None, &path, trait_ref.path.span, trait_ref.path.segments.last().unwrap().span, PathSource::Trait(AliasPossibility::No) ).base_def(); if def != Def::Err { new_id = Some(def.def_id()); let span = trait_ref.path.span; if let PathResult::Module(module) = self.resolve_path(&path, None, false, span) { 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(&mut self, self_def: Def, f: F) where F: FnOnce(&mut Resolver) { let mut self_type_rib = Rib::new(NormalRibKind); // plain insert (no renaming, types are not currently hygienic....) self_type_rib.bindings.insert(keywords::SelfType.ident(), self_def); self.ribs[TypeNS].push(self_type_rib); f(self); self.ribs[TypeNS].pop(); } fn resolve_implementation(&mut self, generics: &Generics, opt_trait_reference: &Option, self_type: &Ty, item_id: NodeId, impl_items: &[ImplItem]) { // If applicable, create a rib for the type parameters. self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| { // Dummy self type for better errors if `Self` is used in the trait path. this.with_self_rib(Def::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(Def::SelfTy(trait_id, Some(item_def_id)), |this| { if let Some(trait_ref) = opt_trait_reference.as_ref() { // Resolve type arguments in trait path visit::walk_trait_ref(this, trait_ref); } // Resolve the self type. this.visit_ty(self_type); // Resolve the type parameters. this.visit_generics(generics); this.with_current_self_type(self_type, |this| { for impl_item in impl_items { this.check_proc_macro_attrs(&impl_item.attrs); this.resolve_visibility(&impl_item.vis); // We also need a new scope for the impl item type parameters. let type_parameters = HasTypeParameters(&impl_item.generics, TraitOrImplItemRibKind); this.with_type_parameter_rib(type_parameters, |this| { use self::ResolutionError::*; match impl_item.node { 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::Macro(_) => panic!("unexpanded macro in resolve!"), } }); } }); }); }); }); }); } fn check_trait_item(&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(module, ident, ns, false, 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()); } // 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(); pat.walk(&mut |pat| { if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node { if sub_pat.is_some() || match self.def_map.get(&pat.id).map(|res| res.base_def()) { Some(Def::Local(..)) => true, _ => false, } { let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode }; binding_map.insert(ident.node, binding_info); } } true }); binding_map } // check 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]) { if pats.is_empty() { return; } let mut missing_vars = FxHashMap(); let mut inconsistent_vars = FxHashMap(); 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.len() == 0 { // 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::>(); 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::>(); 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)); let mut bindings_list = FxHashMap(); for pattern in &arm.pats { self.resolve_pattern(&pattern, PatternSource::Match, &mut bindings_list); } // This has to happen *after* we determine which pat_idents are variants self.check_consistent_bindings(&arm.pats); walk_list!(self, visit_expr, &arm.guard); self.visit_expr(&arm.body); self.ribs[ValueNS].pop(); } 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 def = self.definitions.local_def_id(item.id); self.ribs[ValueNS].push(Rib::new(MacroDefinition(def))); self.label_ribs.push(Rib::new(MacroDefinition(def))); } } 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 let Some(_) = anonymous_module { self.ribs[TypeNS].pop(); } debug!("(resolving block) leaving block"); } fn fresh_binding(&mut self, ident: &SpannedIdent, pat_id: NodeId, outer_pat_id: NodeId, pat_src: PatternSource, bindings: &mut FxHashMap) -> PathResolution { // 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 mut def = Def::Local(pat_id); match bindings.get(&ident.node).cloned() { Some(id) if id == outer_pat_id => { // `Variant(a, a)`, error resolve_error( self, ident.span, ResolutionError::IdentifierBoundMoreThanOnceInSamePattern( &ident.node.name.as_str()) ); } Some(..) if pat_src == PatternSource::FnParam => { // `fn f(a: u8, a: u8)`, error resolve_error( self, ident.span, ResolutionError::IdentifierBoundMoreThanOnceInParameterList( &ident.node.name.as_str()) ); } Some(..) if pat_src == PatternSource::Match || pat_src == PatternSource::IfLet || pat_src == PatternSource::WhileLet => { // `Variant1(a) | Variant2(a)`, ok // Reuse definition from the first `a`. def = self.ribs[ValueNS].last_mut().unwrap().bindings[&ident.node]; } 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.node.name != keywords::Invalid.name() { bindings.insert(ident.node, outer_pat_id); self.ribs[ValueNS].last_mut().unwrap().bindings.insert(ident.node, def); } } } PathResolution::new(def) } 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) { // Visit all direct subpatterns of this pattern. let outer_pat_id = pat.id; pat.walk(&mut |pat| { match pat.node { PatKind::Ident(bmode, ref 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.node, ValueNS, false, pat.span) .and_then(LexicalScopeBinding::item); let resolution = binding.map(NameBinding::def).and_then(|def| { let is_syntactic_ambiguity = opt_pat.is_none() && bmode == BindingMode::ByValue(Mutability::Immutable); match def { Def::StructCtor(_, CtorKind::Const) | Def::VariantCtor(_, CtorKind::Const) | Def::Const(..) if is_syntactic_ambiguity => { // Disambiguate in favor of a unit struct/variant // or constant pattern. self.record_use(ident.node, ValueNS, binding.unwrap(), ident.span); Some(PathResolution::new(def)) } Def::StructCtor(..) | Def::VariantCtor(..) | Def::Const(..) | Def::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.node.name, binding.unwrap()) ); None } Def::Fn(..) | Def::Err => { // These entities are explicitly allowed // to be shadowed by fresh bindings. None } def => { span_bug!(ident.span, "unexpected definition for an \ identifier in pattern: {:?}", def); } } }).unwrap_or_else(|| { self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings) }); self.record_def(pat.id, resolution); } 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) -> PathResolution { let segments = &path.segments.iter() .map(|seg| respan(seg.span, seg.identifier)) .collect::>(); let ident_span = path.segments.last().map_or(path.span, |seg| seg.span); self.smart_resolve_path_fragment(id, qself, segments, path.span, ident_span, source) } fn smart_resolve_path_fragment(&mut self, id: NodeId, qself: Option<&QSelf>, path: &[SpannedIdent], span: Span, ident_span: Span, source: PathSource) -> PathResolution { let ns = source.namespace(); let is_expected = &|def| source.is_expected(def); let is_enum_variant = &|def| if let Def::Variant(..) = def { true } else { false }; // Base error is amended with one short label and possibly some longer helps/notes. let report_errors = |this: &mut Self, def: Option| { // Make the base error. let expected = source.descr_expected(); let path_str = names_to_string(path); let code = source.error_code(def.is_some()); let (base_msg, fallback_label, base_span) = if let Some(def) = def { (format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str), format!("not a {}", expected), span) } else { let item_str = path[path.len() - 1].node; let item_span = path[path.len() - 1].span; let (mod_prefix, mod_str) = if path.len() == 1 { (format!(""), format!("this scope")) } else if path.len() == 2 && path[0].node.name == keywords::CrateRoot.name() { (format!(""), format!("the crate root")) } else { let mod_path = &path[..path.len() - 1]; let mod_prefix = match this.resolve_path(mod_path, Some(TypeNS), false, span) { PathResult::Module(module) => module.def(), _ => None, }.map_or(format!(""), |def| format!("{} ", def.kind_name())); (mod_prefix, format!("`{}`", names_to_string(mod_path))) }; (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str), format!("not found in {}", mod_str), item_span) }; let code = DiagnosticId::Error(code.into()); let mut err = this.session.struct_span_err_with_code(base_span, &base_msg, code); // Emit special messages for unresolved `Self` and `self`. if is_self_type(path, ns) { __diagnostic_used!(E0411); err.code(DiagnosticId::Error("E0411".into())); err.span_label(span, "`Self` is only available in traits and impls"); return (err, Vec::new()); } if is_self_value(path, ns) { __diagnostic_used!(E0424); err.code(DiagnosticId::Error("E0424".into())); err.span_label(span, format!("`self` value is only available in \ methods with `self` parameter")); return (err, Vec::new()); } // Try to lookup the name in more relaxed fashion for better error reporting. let ident = *path.last().unwrap(); let candidates = this.lookup_import_candidates(ident.node.name, ns, is_expected); if candidates.is_empty() && is_expected(Def::Enum(DefId::local(CRATE_DEF_INDEX))) { let enum_candidates = this.lookup_import_candidates(ident.node.name, ns, is_enum_variant); let mut enum_candidates = enum_candidates.iter() .map(|suggestion| import_candidate_to_paths(&suggestion)).collect::>(); enum_candidates.sort(); for (sp, variant_path, enum_path) in enum_candidates { if sp == DUMMY_SP { let msg = format!("there is an enum variant `{}`, \ try using `{}`?", variant_path, enum_path); err.help(&msg); } else { err.span_suggestion(span, "you can try using the variant's enum", enum_path); } } } if path.len() == 1 && this.self_type_is_available(span) { if let Some(candidate) = this.lookup_assoc_candidate(ident.node, ns, is_expected) { let self_is_available = this.self_value_is_available(path[0].node.ctxt, span); match candidate { AssocSuggestion::Field => { err.span_suggestion(span, "try", format!("self.{}", path_str)); if !self_is_available { err.span_label(span, format!("`self` value is only available in \ methods with `self` parameter")); } } AssocSuggestion::MethodWithSelf if self_is_available => { err.span_suggestion(span, "try", format!("self.{}", path_str)); } AssocSuggestion::MethodWithSelf | AssocSuggestion::AssocItem => { err.span_suggestion(span, "try", format!("Self::{}", path_str)); } } return (err, candidates); } } let mut levenshtein_worked = false; // Try Levenshtein. if let Some(candidate) = this.lookup_typo_candidate(path, ns, is_expected, span) { err.span_label(ident_span, format!("did you mean `{}`?", candidate)); levenshtein_worked = true; } // Try context dependent help if relaxed lookup didn't work. if let Some(def) = def { match (def, source) { (Def::Macro(..), _) => { err.span_label(span, format!("did you mean `{}!(...)`?", path_str)); return (err, candidates); } (Def::TyAlias(..), PathSource::Trait(_)) => { err.span_label(span, "type aliases cannot be used for traits"); return (err, candidates); } (Def::Mod(..), PathSource::Expr(Some(parent))) => match parent.node { ExprKind::Field(_, ident) => { err.span_label(parent.span, format!("did you mean `{}::{}`?", path_str, ident.node)); return (err, candidates); } ExprKind::MethodCall(ref segment, ..) => { err.span_label(parent.span, format!("did you mean `{}::{}(...)`?", path_str, segment.identifier)); return (err, candidates); } _ => {} }, (Def::Enum(..), PathSource::TupleStruct) | (Def::Enum(..), PathSource::Expr(..)) => { if let Some(variants) = this.collect_enum_variants(def) { err.note(&format!("did you mean to use one \ of the following variants?\n{}", variants.iter() .map(|suggestion| path_names_to_string(suggestion)) .map(|suggestion| format!("- `{}`", suggestion)) .collect::>() .join("\n"))); } else { err.note("did you mean to use one of the enum's variants?"); } return (err, candidates); }, (Def::Struct(def_id), _) if ns == ValueNS => { if let Some((ctor_def, ctor_vis)) = this.struct_constructors.get(&def_id).cloned() { let accessible_ctor = this.is_accessible(ctor_vis); if is_expected(ctor_def) && !accessible_ctor { err.span_label(span, format!("constructor is not visible \ here due to private fields")); } } else { err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?", path_str)); } return (err, candidates); } (Def::Union(..), _) | (Def::Variant(..), _) | (Def::VariantCtor(_, CtorKind::Fictive), _) if ns == ValueNS => { err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?", path_str)); return (err, candidates); } (Def::SelfTy(..), _) if ns == ValueNS => { err.span_label(span, fallback_label); err.note("can't use `Self` as a constructor, you must use the \ implemented struct"); return (err, candidates); } (Def::TyAlias(_), _) | (Def::AssociatedTy(..), _) if ns == ValueNS => { err.note("can't use a type alias as a constructor"); return (err, candidates); } _ => {} } } // Fallback label. if !levenshtein_worked { err.span_label(base_span, fallback_label); this.type_ascription_suggestion(&mut err, base_span); } (err, candidates) }; let report_errors = |this: &mut Self, def: Option| { let (err, candidates) = report_errors(this, def); let def_id = this.current_module.normal_ancestor_id; let node_id = this.definitions.as_local_node_id(def_id).unwrap(); let better = def.is_some(); this.use_injections.push(UseError { err, candidates, node_id, better }); err_path_resolution() }; let resolution = match self.resolve_qpath_anywhere(id, qself, path, ns, span, source.defer_to_typeck(), source.global_by_default()) { Some(resolution) if resolution.unresolved_segments() == 0 => { if is_expected(resolution.base_def()) || resolution.base_def() == Def::Err { resolution } 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 Def::Struct(def_id) = resolution.base_def() { if let Some((ctor_def, ctor_vis)) = self.struct_constructors.get(&def_id).cloned() { if is_expected(ctor_def) && 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(PathResolution::new(ctor_def)); } } } res.unwrap_or_else(|| report_errors(self, Some(resolution.base_def()))) } } Some(resolution) if source.defer_to_typeck() => { // Not fully resolved associated item `T::A::B` or `::A::B` // or `::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().node; let traits = self.get_traits_containing_item(item_name, ns); self.trait_map.insert(id, traits); } resolution } _ => report_errors(self, None) }; if let PathSource::TraitItem(..) = source {} else { // Avoid recording definition of `A::B` in `::B::C`. self.record_def(id, resolution); } resolution } fn type_ascription_suggestion(&self, err: &mut DiagnosticBuilder, base_span: Span) { debug!("type_ascription_suggetion {:?}", base_span); let cm = self.session.codemap(); 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))) { debug!("snippet {:?}", snippet); let line_sp = cm.lookup_char_pos(sp.hi()).line; let line_base_sp = cm.lookup_char_pos(base_span.lo()).line; debug!("{:?} {:?}", line_sp, line_base_sp); if snippet == ":" { err.span_label(base_span, "expecting a type here because of type ascription"); if line_sp != line_base_sp { err.span_suggestion_short(sp, "did you mean to use `;` here instead?", ";".to_string()); } break; } else if snippet.trim().len() != 0 { 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(keywords::SelfType.ident(), TypeNS, false, span); if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::Err } else { false } } fn self_value_is_available(&mut self, ctxt: SyntaxContext, span: Span) -> bool { let ident = Ident { name: keywords::SelfValue.name(), ctxt: ctxt }; let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, false, span); if let Some(LexicalScopeBinding::Def(def)) = binding { def != Def::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: &[SpannedIdent], primary_ns: Namespace, span: Span, defer_to_typeck: bool, global_by_default: bool) -> Option { 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) { // If defer_to_typeck, then resolution > no resolution, // otherwise full resolution > partial resolution > no resolution. Some(res) if res.unresolved_segments() == 0 || defer_to_typeck => return Some(res), res => if fin_res.is_none() { fin_res = res }, }; } } let is_global = self.global_macros.get(&path[0].node.name).cloned() .map(|binding| binding.get_macro(self).kind() == MacroKind::Bang).unwrap_or(false); if primary_ns != MacroNS && (is_global || self.macro_names.contains(&path[0].node.modern())) { // Return some dummy definition, it's enough for error reporting. return Some( PathResolution::new(Def::Macro(DefId::local(CRATE_DEF_INDEX), MacroKind::Bang)) ); } fin_res } /// Handles paths that may refer to associated items. fn resolve_qpath(&mut self, id: NodeId, qself: Option<&QSelf>, path: &[SpannedIdent], ns: Namespace, span: Span, global_by_default: bool) -> Option { if let Some(qself) = qself { if qself.position == 0 { // FIXME: Create some fake resolution that can't possibly be a type. return Some(PathResolution::with_unresolved_segments( Def::Mod(DefId::local(CRATE_DEF_INDEX)), path.len() )); } // Make sure `A::B` in `::B::C` is a trait item. let ns = if qself.position + 1 == path.len() { ns } else { TypeNS }; let res = self.smart_resolve_path_fragment(id, None, &path[..qself.position + 1], span, span, PathSource::TraitItem(ns)); return Some(PathResolution::with_unresolved_segments( res.base_def(), res.unresolved_segments() + path.len() - qself.position - 1 )); } let result = match self.resolve_path(&path, Some(ns), true, span) { PathResult::NonModule(path_res) => path_res, PathResult::Module(module) if !module.is_normal() => { PathResolution::new(module.def().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 ::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(..) | PathResult::Failed(..) if (ns == TypeNS || path.len() > 1) && self.primitive_type_table.primitive_types .contains_key(&path[0].node.name) => { let prim = self.primitive_type_table.primitive_types[&path[0].node.name]; match prim { TyUint(UintTy::U128) | TyInt(IntTy::I128) => { if !self.session.features_untracked().i128_type { emit_feature_err(&self.session.parse_sess, "i128_type", span, GateIssue::Language, "128-bit type is unstable"); } } _ => {} } PathResolution::with_unresolved_segments(Def::PrimTy(prim), path.len() - 1) } PathResult::Module(module) => PathResolution::new(module.def().unwrap()), PathResult::Failed(span, msg, false) => { resolve_error(self, span, ResolutionError::FailedToResolve(&msg)); err_path_resolution() } PathResult::Failed(..) => return None, PathResult::Indeterminate => bug!("indetermined path result in resolve_qpath"), }; if path.len() > 1 && !global_by_default && result.base_def() != Def::Err && path[0].node.name != keywords::CrateRoot.name() && path[0].node.name != keywords::DollarCrate.name() { let unqualified_result = { match self.resolve_path(&[*path.last().unwrap()], Some(ns), false, span) { PathResult::NonModule(path_res) => path_res.base_def(), PathResult::Module(module) => module.def().unwrap(), _ => return Some(result), } }; if result.base_def() == unqualified_result { let lint = lint::builtin::UNUSED_QUALIFICATIONS; self.session.buffer_lint(lint, id, span, "unnecessary qualification") } } Some(result) } fn resolve_path(&mut self, path: &[SpannedIdent], opt_ns: Option, // `None` indicates a module path record_used: bool, path_span: Span) -> PathResult<'a> { let mut module = None; let mut allow_super = true; for (i, &ident) in path.iter().enumerate() { debug!("resolve_path ident {} {:?}", i, ident); let is_last = i == path.len() - 1; let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS }; let name = ident.node.name; if i == 0 && ns == TypeNS && name == keywords::SelfValue.name() { let mut ctxt = ident.node.ctxt.modern(); module = Some(self.resolve_self(&mut ctxt, self.current_module)); continue } else if allow_super && ns == TypeNS && name == keywords::Super.name() { let mut ctxt = ident.node.ctxt.modern(); let self_module = match i { 0 => self.resolve_self(&mut ctxt, self.current_module), _ => module.unwrap(), }; if let Some(parent) = self_module.parent { module = Some(self.resolve_self(&mut ctxt, parent)); continue } else { let msg = "There are too many initial `super`s.".to_string(); return PathResult::Failed(ident.span, msg, false); } } else if i == 0 && ns == TypeNS && name == keywords::Extern.name() { continue; } allow_super = false; if ns == TypeNS { if (i == 0 && name == keywords::CrateRoot.name()) || (i == 1 && name == keywords::Crate.name() && path[0].node.name == keywords::CrateRoot.name()) { // `::a::b` or `::crate::a::b` module = Some(self.resolve_crate_root(ident.node.ctxt, false)); continue } else if i == 0 && name == keywords::DollarCrate.name() { // `$crate::a::b` module = Some(self.resolve_crate_root(ident.node.ctxt, true)); continue } else if i == 1 && !token::Ident(ident.node).is_path_segment_keyword() { let prev_name = path[0].node.name; if prev_name == keywords::Extern.name() || prev_name == keywords::CrateRoot.name() && self.session.features_untracked().extern_absolute_paths { // `::extern_crate::a::b` let crate_id = self.crate_loader.resolve_crate_from_path(name, ident.span); let crate_root = self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX }); self.populate_module_if_necessary(crate_root); module = Some(crate_root); continue } } } // Report special messages for path segment keywords in wrong positions. if name == keywords::CrateRoot.name() && i != 0 || name == keywords::DollarCrate.name() && i != 0 || name == keywords::SelfValue.name() && i != 0 || name == keywords::SelfType.name() && i != 0 || name == keywords::Super.name() && i != 0 || name == keywords::Extern.name() && i != 0 || name == keywords::Crate.name() && i != 1 && path[0].node.name != keywords::CrateRoot.name() { let name_str = if name == keywords::CrateRoot.name() { format!("crate root") } else { format!("`{}`", name) }; let msg = if i == 1 && path[0].node.name == keywords::CrateRoot.name() { format!("global paths cannot start with {}", name_str) } else if i == 0 && name == keywords::Crate.name() { format!("{} can only be used in absolute paths", name_str) } else { format!("{} in paths can only be used in start position", name_str) }; return PathResult::Failed(ident.span, msg, false); } let binding = if let Some(module) = module { self.resolve_ident_in_module(module, ident.node, ns, false, record_used, path_span) } else if opt_ns == Some(MacroNS) { self.resolve_lexical_macro_path_segment(ident.node, ns, record_used, path_span) .map(MacroBinding::binding) } else { match self.resolve_ident_in_lexical_scope(ident.node, ns, record_used, path_span) { Some(LexicalScopeBinding::Item(binding)) => Ok(binding), Some(LexicalScopeBinding::Def(def)) if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) => { return PathResult::NonModule(PathResolution::with_unresolved_segments( def, path.len() - 1 )); } _ => Err(if record_used { Determined } else { Undetermined }), } }; match binding { Ok(binding) => { let def = binding.def(); let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(def); if let Some(next_module) = binding.module() { module = Some(next_module); } else if def == Def::Err { return PathResult::NonModule(err_path_resolution()); } else if opt_ns.is_some() && (is_last || maybe_assoc) { return PathResult::NonModule(PathResolution::with_unresolved_segments( def, path.len() - i - 1 )); } else { return PathResult::Failed(ident.span, format!("Not a module `{}`", ident.node), is_last); } } Err(Undetermined) => return PathResult::Indeterminate, Err(Determined) => { if let Some(module) = module { if opt_ns.is_some() && !module.is_normal() { return PathResult::NonModule(PathResolution::with_unresolved_segments( module.def().unwrap(), path.len() - i )); } } let msg = if module.and_then(ModuleData::def) == self.graph_root.def() { let is_mod = |def| match def { Def::Mod(..) => true, _ => false }; let mut candidates = self.lookup_import_candidates(name, TypeNS, is_mod); candidates.sort_by_key(|c| (c.path.segments.len(), c.path.to_string())); if let Some(candidate) = candidates.get(0) { format!("Did you mean `{}`?", candidate.path) } else { format!("Maybe a missing `extern crate {};`?", ident.node) } } else if i == 0 { format!("Use of undeclared type or module `{}`", ident.node) } else { format!("Could not find `{}` in `{}`", ident.node, path[i - 1].node) }; return PathResult::Failed(ident.span, msg, is_last); } } } PathResult::Module(module.unwrap_or(self.graph_root)) } // Resolve a local definition, potentially adjusting for closures. fn adjust_local_def(&mut self, ns: Namespace, rib_index: usize, mut def: Def, record_used: bool, span: Span) -> Def { 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!(def, Def::Err); return Def::Err; } match def { Def::Upvar(..) => { span_bug!(span, "unexpected {:?} in bindings", def) } Def::Local(node_id) => { for rib in ribs { match rib.kind { NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind => { // Nothing to do. Continue. } ClosureRibKind(function_id) => { let prev_def = def; let seen = self.freevars_seen .entry(function_id) .or_insert_with(|| NodeMap()); if let Some(&index) = seen.get(&node_id) { def = Def::Upvar(node_id, index, function_id); continue; } let vec = self.freevars .entry(function_id) .or_insert_with(|| vec![]); let depth = vec.len(); def = Def::Upvar(node_id, depth, function_id); if record_used { vec.push(Freevar { def: prev_def, span, }); seen.insert(node_id, depth); } } ItemRibKind | TraitOrImplItemRibKind => { // 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 { resolve_error(self, span, ResolutionError::CannotCaptureDynamicEnvironmentInFnItem); } return Def::Err; } ConstantItemRibKind => { // Still doesn't deal with upvars if record_used { resolve_error(self, span, ResolutionError::AttemptToUseNonConstantValueInConstant); } return Def::Err; } } } } Def::TyParam(..) | Def::SelfTy(..) => { for rib in ribs { match rib.kind { NormalRibKind | TraitOrImplItemRibKind | ClosureRibKind(..) | ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind | ConstantItemRibKind => { // Nothing to do. Continue. } ItemRibKind => { // This was an attempt to use a type parameter outside // its scope. if record_used { resolve_error(self, span, ResolutionError::TypeParametersFromOuterFunction); } return Def::Err; } } } } _ => {} } return def; } fn lookup_assoc_candidate(&mut self, ident: Ident, ns: Namespace, filter_fn: FilterFn) -> Option where FilterFn: Fn(Def) -> bool { fn extract_node_id(t: &Ty) -> Option { 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(Def::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.def_map.get(&node_id) { match resolution.base_def() { Def::Struct(did) | Def::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(module, ident, ns, false, false, module.span) { let def = binding.def(); if filter_fn(def) { return Some(if self.has_self.contains(&def.def_id()) { AssocSuggestion::MethodWithSelf } else { AssocSuggestion::AssocItem }); } } } None } fn lookup_typo_candidate(&mut self, path: &[SpannedIdent], ns: Namespace, filter_fn: FilterFn, span: Span) -> Option where FilterFn: Fn(Def) -> bool { let add_module_candidates = |module: Module, names: &mut Vec| { for (&(ident, _), resolution) in module.resolutions.borrow().iter() { if let Some(binding) = resolution.borrow().binding { if filter_fn(binding.def()) { names.push(ident.name); } } } }; 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, def) in &rib.bindings { if filter_fn(*def) { names.push(ident.name); } } // 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 let Some(prelude) = self.prelude { if !module.no_implicit_prelude { add_module_candidates(prelude, &mut names); } } break; } } } // Add primitive types to the mix if filter_fn(Def::PrimTy(TyBool)) { for (name, _) in &self.primitive_type_table.primitive_types { names.push(*name); } } } else { // Search in module. let mod_path = &path[..path.len() - 1]; if let PathResult::Module(module) = self.resolve_path(mod_path, Some(TypeNS), false, span) { add_module_candidates(module, &mut names); } } let name = path[path.len() - 1].node.name; // Make sure error reporting is deterministic. names.sort_by_key(|name| name.as_str()); match find_best_match_for_name(names.iter(), &name.as_str(), None) { Some(found) if found != name => Some(found), _ => None, } } fn with_resolved_label(&mut self, label: Option