| use std::cmp::Reverse; |
| use std::ptr; |
| |
| use rustc_ast::{self as ast, Path}; |
| use rustc_ast_pretty::pprust; |
| use rustc_data_structures::fx::FxHashSet; |
| use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder}; |
| use rustc_feature::BUILTIN_ATTRIBUTES; |
| use rustc_hir::def::Namespace::{self, *}; |
| use rustc_hir::def::{self, CtorKind, CtorOf, DefKind, NonMacroAttrKind}; |
| use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX, LOCAL_CRATE}; |
| use rustc_hir::PrimTy; |
| use rustc_middle::bug; |
| use rustc_middle::ty::{self, DefIdTree}; |
| use rustc_session::Session; |
| use rustc_span::hygiene::MacroKind; |
| use rustc_span::lev_distance::find_best_match_for_name; |
| use rustc_span::source_map::SourceMap; |
| use rustc_span::symbol::{kw, sym, Ident, Symbol}; |
| use rustc_span::{BytePos, MultiSpan, Span}; |
| use tracing::debug; |
| |
| use crate::imports::{Import, ImportKind, ImportResolver}; |
| use crate::path_names_to_string; |
| use crate::{AmbiguityError, AmbiguityErrorMisc, AmbiguityKind}; |
| use crate::{ |
| BindingError, CrateLint, HasGenericParams, MacroRulesScope, Module, ModuleOrUniformRoot, |
| }; |
| use crate::{NameBinding, NameBindingKind, PrivacyError, VisResolutionError}; |
| use crate::{ParentScope, PathResult, ResolutionError, Resolver, Scope, ScopeSet, Segment}; |
| |
| type Res = def::Res<ast::NodeId>; |
| |
| /// A vector of spans and replacements, a message and applicability. |
| crate type Suggestion = (Vec<(Span, String)>, String, Applicability); |
| |
| /// Potential candidate for an undeclared or out-of-scope label - contains the ident of a |
| /// similarly named label and whether or not it is reachable. |
| crate type LabelSuggestion = (Ident, bool); |
| |
| crate struct TypoSuggestion { |
| pub candidate: Symbol, |
| pub res: Res, |
| } |
| |
| impl TypoSuggestion { |
| crate fn from_res(candidate: Symbol, res: Res) -> TypoSuggestion { |
| TypoSuggestion { candidate, res } |
| } |
| } |
| |
| /// A free importable items suggested in case of resolution failure. |
| crate struct ImportSuggestion { |
| pub did: Option<DefId>, |
| pub descr: &'static str, |
| pub path: Path, |
| pub accessible: bool, |
| } |
| |
| /// Adjust the impl span so that just the `impl` keyword is taken by removing |
| /// everything after `<` (`"impl<T> Iterator for A<T> {}" -> "impl"`) and |
| /// everything after the first whitespace (`"impl Iterator for A" -> "impl"`). |
| /// |
| /// *Attention*: the method used is very fragile since it essentially duplicates the work of the |
| /// parser. If you need to use this function or something similar, please consider updating the |
| /// `source_map` functions and this function to something more robust. |
| fn reduce_impl_span_to_impl_keyword(sm: &SourceMap, impl_span: Span) -> Span { |
| let impl_span = sm.span_until_char(impl_span, '<'); |
| sm.span_until_whitespace(impl_span) |
| } |
| |
| impl<'a> Resolver<'a> { |
| crate fn add_module_candidates( |
| &mut self, |
| module: Module<'a>, |
| names: &mut Vec<TypoSuggestion>, |
| filter_fn: &impl Fn(Res) -> bool, |
| ) { |
| for (key, resolution) in self.resolutions(module).borrow().iter() { |
| if let Some(binding) = resolution.borrow().binding { |
| let res = binding.res(); |
| if filter_fn(res) { |
| names.push(TypoSuggestion::from_res(key.ident.name, res)); |
| } |
| } |
| } |
| } |
| |
| /// Combines an error with provided span and emits it. |
| /// |
| /// This takes the error provided, combines it with the span and any additional spans inside the |
| /// error and emits it. |
| crate fn report_error(&self, span: Span, resolution_error: ResolutionError<'_>) { |
| self.into_struct_error(span, resolution_error).emit(); |
| } |
| |
| crate fn into_struct_error( |
| &self, |
| span: Span, |
| resolution_error: ResolutionError<'_>, |
| ) -> DiagnosticBuilder<'_> { |
| match resolution_error { |
| ResolutionError::GenericParamsFromOuterFunction(outer_res, has_generic_params) => { |
| let mut err = struct_span_err!( |
| self.session, |
| span, |
| E0401, |
| "can't use generic parameters from outer function", |
| ); |
| err.span_label(span, "use of generic parameter from outer function".to_string()); |
| |
| let sm = self.session.source_map(); |
| match outer_res { |
| Res::SelfTy(maybe_trait_defid, maybe_impl_defid) => { |
| if let Some(impl_span) = |
| maybe_impl_defid.and_then(|(def_id, _)| self.opt_span(def_id)) |
| { |
| err.span_label( |
| reduce_impl_span_to_impl_keyword(sm, impl_span), |
| "`Self` type implicitly declared here, by this `impl`", |
| ); |
| } |
| match (maybe_trait_defid, maybe_impl_defid) { |
| (Some(_), None) => { |
| err.span_label(span, "can't use `Self` here"); |
| } |
| (_, Some(_)) => { |
| err.span_label(span, "use a type here instead"); |
| } |
| (None, None) => bug!("`impl` without trait nor type?"), |
| } |
| return err; |
| } |
| Res::Def(DefKind::TyParam, def_id) => { |
| if let Some(span) = self.opt_span(def_id) { |
| err.span_label(span, "type parameter from outer function"); |
| } |
| } |
| Res::Def(DefKind::ConstParam, def_id) => { |
| if let Some(span) = self.opt_span(def_id) { |
| err.span_label(span, "const parameter from outer function"); |
| } |
| } |
| _ => { |
| bug!( |
| "GenericParamsFromOuterFunction should only be used with Res::SelfTy, \ |
| DefKind::TyParam or DefKind::ConstParam" |
| ); |
| } |
| } |
| |
| if has_generic_params == HasGenericParams::Yes { |
| // Try to retrieve the span of the function signature and generate a new |
| // message with a local type or const parameter. |
| let sugg_msg = "try using a local generic parameter instead"; |
| if let Some((sugg_span, snippet)) = sm.generate_local_type_param_snippet(span) { |
| // Suggest the modification to the user |
| err.span_suggestion( |
| sugg_span, |
| sugg_msg, |
| snippet, |
| Applicability::MachineApplicable, |
| ); |
| } else if let Some(sp) = sm.generate_fn_name_span(span) { |
| err.span_label( |
| sp, |
| "try adding a local generic parameter in this method instead" |
| .to_string(), |
| ); |
| } else { |
| err.help("try using a local generic parameter instead"); |
| } |
| } |
| |
| err |
| } |
| ResolutionError::NameAlreadyUsedInParameterList(name, first_use_span) => { |
| let mut err = struct_span_err!( |
| self.session, |
| span, |
| E0403, |
| "the name `{}` is already used for a generic \ |
| parameter in this item's generic parameters", |
| name, |
| ); |
| err.span_label(span, "already used"); |
| err.span_label(first_use_span, format!("first use of `{}`", name)); |
| err |
| } |
| ResolutionError::MethodNotMemberOfTrait(method, trait_) => { |
| let mut err = struct_span_err!( |
| self.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!( |
| self.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!( |
| self.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 BindingError { name, target, origin, could_be_path } = binding_error; |
| |
| let target_sp = target.iter().copied().collect::<Vec<_>>(); |
| let origin_sp = origin.iter().copied().collect::<Vec<_>>(); |
| |
| let msp = MultiSpan::from_spans(target_sp.clone()); |
| let mut err = struct_span_err!( |
| self.session, |
| msp, |
| E0408, |
| "variable `{}` is not bound in all patterns", |
| name, |
| ); |
| for sp in target_sp { |
| err.span_label(sp, format!("pattern doesn't bind `{}`", name)); |
| } |
| for sp in origin_sp { |
| err.span_label(sp, "variable not in all patterns"); |
| } |
| if *could_be_path { |
| let help_msg = format!( |
| "if you meant to match on a variant or a `const` item, consider \ |
| making the path in the pattern qualified: `?::{}`", |
| name, |
| ); |
| err.span_help(span, &help_msg); |
| } |
| err |
| } |
| ResolutionError::VariableBoundWithDifferentMode(variable_name, first_binding_span) => { |
| let mut err = struct_span_err!( |
| self.session, |
| span, |
| E0409, |
| "variable `{}` is bound inconsistently across alternatives separated by `|`", |
| 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!( |
| self.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!( |
| self.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, suggestion } => { |
| let mut err = struct_span_err!( |
| self.session, |
| span, |
| E0426, |
| "use of undeclared label `{}`", |
| name |
| ); |
| |
| err.span_label(span, format!("undeclared label `{}`", name)); |
| |
| match suggestion { |
| // A reachable label with a similar name exists. |
| Some((ident, true)) => { |
| err.span_label(ident.span, "a label with a similar name is reachable"); |
| err.span_suggestion( |
| span, |
| "try using similarly named label", |
| ident.name.to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| // An unreachable label with a similar name exists. |
| Some((ident, false)) => { |
| err.span_label( |
| ident.span, |
| "a label with a similar name exists but is unreachable", |
| ); |
| } |
| // No similarly-named labels exist. |
| None => (), |
| } |
| |
| err |
| } |
| ResolutionError::SelfImportsOnlyAllowedWithin { root, span_with_rename } => { |
| let mut err = struct_span_err!( |
| self.session, |
| span, |
| E0429, |
| "{}", |
| "`self` imports are only allowed within a { } list" |
| ); |
| |
| // None of the suggestions below would help with a case like `use self`. |
| if !root { |
| // use foo::bar::self -> foo::bar |
| // use foo::bar::self as abc -> foo::bar as abc |
| err.span_suggestion( |
| span, |
| "consider importing the module directly", |
| "".to_string(), |
| Applicability::MachineApplicable, |
| ); |
| |
| // use foo::bar::self -> foo::bar::{self} |
| // use foo::bar::self as abc -> foo::bar::{self as abc} |
| let braces = vec![ |
| (span_with_rename.shrink_to_lo(), "{".to_string()), |
| (span_with_rename.shrink_to_hi(), "}".to_string()), |
| ]; |
| err.multipart_suggestion( |
| "alternatively, use the multi-path `use` syntax to import `self`", |
| braces, |
| Applicability::MachineApplicable, |
| ); |
| } |
| err |
| } |
| ResolutionError::SelfImportCanOnlyAppearOnceInTheList => { |
| let mut err = struct_span_err!( |
| self.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!( |
| self.session, |
| span, |
| E0431, |
| "`self` import can only appear in an import list with \ |
| a non-empty prefix" |
| ); |
| err.span_label(span, "can only appear in an import list with a non-empty prefix"); |
| err |
| } |
| ResolutionError::FailedToResolve { label, suggestion } => { |
| let mut err = |
| struct_span_err!(self.session, span, E0433, "failed to resolve: {}", &label); |
| err.span_label(span, label); |
| |
| if let Some((suggestions, msg, applicability)) = suggestion { |
| err.multipart_suggestion(&msg, suggestions, applicability); |
| } |
| |
| err |
| } |
| ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => { |
| let mut err = struct_span_err!( |
| self.session, |
| span, |
| E0434, |
| "{}", |
| "can't capture dynamic environment in a fn item" |
| ); |
| err.help("use the `|| { ... }` closure form instead"); |
| err |
| } |
| ResolutionError::AttemptToUseNonConstantValueInConstant(ident, sugg, current) => { |
| let mut err = struct_span_err!( |
| self.session, |
| span, |
| E0435, |
| "attempt to use a non-constant value in a constant" |
| ); |
| // let foo =... |
| // ^^^ given this Span |
| // ------- get this Span to have an applicable suggestion |
| let sp = |
| self.session.source_map().span_extend_to_prev_str(ident.span, current, true); |
| if sp.lo().0 == 0 { |
| err.span_label(ident.span, &format!("this would need to be a `{}`", sugg)); |
| } else { |
| let sp = sp.with_lo(BytePos(sp.lo().0 - current.len() as u32)); |
| err.span_suggestion( |
| sp, |
| &format!("consider using `{}` instead of `{}`", sugg, current), |
| format!("{} {}", sugg, ident), |
| Applicability::MaybeIncorrect, |
| ); |
| err.span_label(span, "non-constant value"); |
| } |
| err |
| } |
| ResolutionError::BindingShadowsSomethingUnacceptable { |
| shadowing_binding_descr, |
| name, |
| participle, |
| article, |
| shadowed_binding_descr, |
| shadowed_binding_span, |
| } => { |
| let mut err = struct_span_err!( |
| self.session, |
| span, |
| E0530, |
| "{}s cannot shadow {}s", |
| shadowing_binding_descr, |
| shadowed_binding_descr, |
| ); |
| err.span_label( |
| span, |
| format!("cannot be named the same as {} {}", article, shadowed_binding_descr), |
| ); |
| let msg = |
| format!("the {} `{}` is {} here", shadowed_binding_descr, name, participle); |
| err.span_label(shadowed_binding_span, msg); |
| err |
| } |
| ResolutionError::ForwardDeclaredGenericParam => { |
| let mut err = struct_span_err!( |
| self.session, |
| span, |
| E0128, |
| "generic parameters with a default cannot use \ |
| forward declared identifiers" |
| ); |
| err.span_label( |
| span, |
| "defaulted generic parameters cannot be forward declared".to_string(), |
| ); |
| err |
| } |
| ResolutionError::ParamInTyOfConstParam(name) => { |
| let mut err = struct_span_err!( |
| self.session, |
| span, |
| E0770, |
| "the type of const parameters must not depend on other generic parameters" |
| ); |
| err.span_label( |
| span, |
| format!("the type must not depend on the parameter `{}`", name), |
| ); |
| err |
| } |
| ResolutionError::ParamInNonTrivialAnonConst { name, is_type } => { |
| let mut err = self.session.struct_span_err( |
| span, |
| "generic parameters may not be used in const operations", |
| ); |
| err.span_label(span, &format!("cannot perform const operation using `{}`", name)); |
| |
| if is_type { |
| err.note("type parameters may not be used in const expressions"); |
| } else { |
| err.help(&format!( |
| "const parameters may only be used as standalone arguments, i.e. `{}`", |
| name |
| )); |
| } |
| |
| if self.session.is_nightly_build() { |
| err.help( |
| "use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` \ |
| to allow generic const expressions" |
| ); |
| } |
| |
| err |
| } |
| ResolutionError::SelfInGenericParamDefault => { |
| let mut err = struct_span_err!( |
| self.session, |
| span, |
| E0735, |
| "generic parameters cannot use `Self` in their defaults" |
| ); |
| err.span_label(span, "`Self` in generic parameter default".to_string()); |
| err |
| } |
| ResolutionError::UnreachableLabel { name, definition_span, suggestion } => { |
| let mut err = struct_span_err!( |
| self.session, |
| span, |
| E0767, |
| "use of unreachable label `{}`", |
| name, |
| ); |
| |
| err.span_label(definition_span, "unreachable label defined here"); |
| err.span_label(span, format!("unreachable label `{}`", name)); |
| err.note( |
| "labels are unreachable through functions, closures, async blocks and modules", |
| ); |
| |
| match suggestion { |
| // A reachable label with a similar name exists. |
| Some((ident, true)) => { |
| err.span_label(ident.span, "a label with a similar name is reachable"); |
| err.span_suggestion( |
| span, |
| "try using similarly named label", |
| ident.name.to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| // An unreachable label with a similar name exists. |
| Some((ident, false)) => { |
| err.span_label( |
| ident.span, |
| "a label with a similar name exists but is also unreachable", |
| ); |
| } |
| // No similarly-named labels exist. |
| None => (), |
| } |
| |
| err |
| } |
| } |
| } |
| |
| crate fn report_vis_error(&self, vis_resolution_error: VisResolutionError<'_>) { |
| match vis_resolution_error { |
| VisResolutionError::Relative2018(span, path) => { |
| let mut err = self.session.struct_span_err( |
| span, |
| "relative paths are not supported in visibilities on 2018 edition", |
| ); |
| err.span_suggestion( |
| path.span, |
| "try", |
| format!("crate::{}", pprust::path_to_string(&path)), |
| Applicability::MaybeIncorrect, |
| ); |
| err |
| } |
| VisResolutionError::AncestorOnly(span) => struct_span_err!( |
| self.session, |
| span, |
| E0742, |
| "visibilities can only be restricted to ancestor modules" |
| ), |
| VisResolutionError::FailedToResolve(span, label, suggestion) => { |
| self.into_struct_error(span, ResolutionError::FailedToResolve { label, suggestion }) |
| } |
| VisResolutionError::ExpectedFound(span, path_str, res) => { |
| let mut err = struct_span_err!( |
| self.session, |
| span, |
| E0577, |
| "expected module, found {} `{}`", |
| res.descr(), |
| path_str |
| ); |
| err.span_label(span, "not a module"); |
| err |
| } |
| VisResolutionError::Indeterminate(span) => struct_span_err!( |
| self.session, |
| span, |
| E0578, |
| "cannot determine resolution for the visibility" |
| ), |
| VisResolutionError::ModuleOnly(span) => { |
| self.session.struct_span_err(span, "visibility must resolve to a module") |
| } |
| } |
| .emit() |
| } |
| |
| /// Lookup typo candidate in scope for a macro or import. |
| fn early_lookup_typo_candidate( |
| &mut self, |
| scope_set: ScopeSet<'a>, |
| parent_scope: &ParentScope<'a>, |
| ident: Ident, |
| filter_fn: &impl Fn(Res) -> bool, |
| ) -> Option<TypoSuggestion> { |
| let mut suggestions = Vec::new(); |
| let ctxt = ident.span.ctxt(); |
| self.visit_scopes(scope_set, parent_scope, ctxt, |this, scope, use_prelude, _| { |
| match scope { |
| Scope::DeriveHelpers(expn_id) => { |
| let res = Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper); |
| if filter_fn(res) { |
| suggestions.extend( |
| this.helper_attrs |
| .get(&expn_id) |
| .into_iter() |
| .flatten() |
| .map(|ident| TypoSuggestion::from_res(ident.name, res)), |
| ); |
| } |
| } |
| Scope::DeriveHelpersCompat => { |
| let res = Res::NonMacroAttr(NonMacroAttrKind::DeriveHelperCompat); |
| if filter_fn(res) { |
| for derive in parent_scope.derives { |
| let parent_scope = &ParentScope { derives: &[], ..*parent_scope }; |
| if let Ok((Some(ext), _)) = this.resolve_macro_path( |
| derive, |
| Some(MacroKind::Derive), |
| parent_scope, |
| false, |
| false, |
| ) { |
| suggestions.extend( |
| ext.helper_attrs |
| .iter() |
| .map(|name| TypoSuggestion::from_res(*name, res)), |
| ); |
| } |
| } |
| } |
| } |
| Scope::MacroRules(macro_rules_scope) => { |
| if let MacroRulesScope::Binding(macro_rules_binding) = macro_rules_scope.get() { |
| let res = macro_rules_binding.binding.res(); |
| if filter_fn(res) { |
| suggestions |
| .push(TypoSuggestion::from_res(macro_rules_binding.ident.name, res)) |
| } |
| } |
| } |
| Scope::CrateRoot => { |
| let root_ident = Ident::new(kw::PathRoot, ident.span); |
| let root_module = this.resolve_crate_root(root_ident); |
| this.add_module_candidates(root_module, &mut suggestions, filter_fn); |
| } |
| Scope::Module(module, _) => { |
| this.add_module_candidates(module, &mut suggestions, filter_fn); |
| } |
| Scope::RegisteredAttrs => { |
| let res = Res::NonMacroAttr(NonMacroAttrKind::Registered); |
| if filter_fn(res) { |
| suggestions.extend( |
| this.registered_attrs |
| .iter() |
| .map(|ident| TypoSuggestion::from_res(ident.name, res)), |
| ); |
| } |
| } |
| Scope::MacroUsePrelude => { |
| suggestions.extend(this.macro_use_prelude.iter().filter_map( |
| |(name, binding)| { |
| let res = binding.res(); |
| filter_fn(res).then_some(TypoSuggestion::from_res(*name, res)) |
| }, |
| )); |
| } |
| Scope::BuiltinAttrs => { |
| let res = Res::NonMacroAttr(NonMacroAttrKind::Builtin(kw::Empty)); |
| if filter_fn(res) { |
| suggestions.extend( |
| BUILTIN_ATTRIBUTES |
| .iter() |
| .map(|(name, ..)| TypoSuggestion::from_res(*name, res)), |
| ); |
| } |
| } |
| Scope::ExternPrelude => { |
| suggestions.extend(this.extern_prelude.iter().filter_map(|(ident, _)| { |
| let res = Res::Def(DefKind::Mod, DefId::local(CRATE_DEF_INDEX)); |
| filter_fn(res).then_some(TypoSuggestion::from_res(ident.name, res)) |
| })); |
| } |
| Scope::ToolPrelude => { |
| let res = Res::NonMacroAttr(NonMacroAttrKind::Tool); |
| suggestions.extend( |
| this.registered_tools |
| .iter() |
| .map(|ident| TypoSuggestion::from_res(ident.name, res)), |
| ); |
| } |
| Scope::StdLibPrelude => { |
| if let Some(prelude) = this.prelude { |
| let mut tmp_suggestions = Vec::new(); |
| this.add_module_candidates(prelude, &mut tmp_suggestions, filter_fn); |
| suggestions.extend( |
| tmp_suggestions |
| .into_iter() |
| .filter(|s| use_prelude || this.is_builtin_macro(s.res)), |
| ); |
| } |
| } |
| Scope::BuiltinTypes => { |
| suggestions.extend(PrimTy::ALL.iter().filter_map(|prim_ty| { |
| let res = Res::PrimTy(*prim_ty); |
| filter_fn(res).then_some(TypoSuggestion::from_res(prim_ty.name(), res)) |
| })) |
| } |
| } |
| |
| None::<()> |
| }); |
| |
| // Make sure error reporting is deterministic. |
| suggestions.sort_by_cached_key(|suggestion| suggestion.candidate.as_str()); |
| |
| match find_best_match_for_name( |
| &suggestions.iter().map(|suggestion| suggestion.candidate).collect::<Vec<Symbol>>(), |
| ident.name, |
| None, |
| ) { |
| Some(found) if found != ident.name => { |
| suggestions.into_iter().find(|suggestion| suggestion.candidate == found) |
| } |
| _ => None, |
| } |
| } |
| |
| fn lookup_import_candidates_from_module<FilterFn>( |
| &mut self, |
| lookup_ident: Ident, |
| namespace: Namespace, |
| parent_scope: &ParentScope<'a>, |
| start_module: Module<'a>, |
| crate_name: Ident, |
| filter_fn: FilterFn, |
| ) -> Vec<ImportSuggestion> |
| where |
| FilterFn: Fn(Res) -> bool, |
| { |
| let mut candidates = Vec::new(); |
| let mut seen_modules = FxHashSet::default(); |
| let mut worklist = vec![(start_module, Vec::<ast::PathSegment>::new(), true)]; |
| let mut worklist_via_import = vec![]; |
| |
| while let Some((in_module, path_segments, accessible)) = match worklist.pop() { |
| None => worklist_via_import.pop(), |
| Some(x) => Some(x), |
| } { |
| let in_module_is_extern = !in_module.def_id().unwrap().is_local(); |
| // We have to visit module children in deterministic order to avoid |
| // instabilities in reported imports (#43552). |
| in_module.for_each_child(self, |this, ident, ns, name_binding| { |
| // avoid non-importable candidates |
| if !name_binding.is_importable() { |
| return; |
| } |
| |
| let child_accessible = |
| accessible && this.is_accessible_from(name_binding.vis, parent_scope.module); |
| |
| // do not venture inside inaccessible items of other crates |
| if in_module_is_extern && !child_accessible { |
| return; |
| } |
| |
| let via_import = name_binding.is_import() && !name_binding.is_extern_crate(); |
| |
| // There is an assumption elsewhere that paths of variants are in the enum's |
| // declaration and not imported. With this assumption, the variant component is |
| // chopped and the rest of the path is assumed to be the enum's own path. For |
| // errors where a variant is used as the type instead of the enum, this causes |
| // funny looking invalid suggestions, i.e `foo` instead of `foo::MyEnum`. |
| if via_import && name_binding.is_possibly_imported_variant() { |
| return; |
| } |
| |
| // collect results based on the filter function |
| // avoid suggesting anything from the same module in which we are resolving |
| if ident.name == lookup_ident.name |
| && ns == namespace |
| && !ptr::eq(in_module, parent_scope.module) |
| { |
| let res = name_binding.res(); |
| if filter_fn(res) { |
| // create the path |
| let mut segms = path_segments.clone(); |
| if lookup_ident.span.rust_2018() { |
| // crate-local absolute paths start with `crate::` in edition 2018 |
| // FIXME: may also be stabilized for Rust 2015 (Issues #45477, #44660) |
| segms.insert(0, ast::PathSegment::from_ident(crate_name)); |
| } |
| |
| segms.push(ast::PathSegment::from_ident(ident)); |
| let path = Path { span: name_binding.span, segments: segms, tokens: None }; |
| let did = match res { |
| Res::Def(DefKind::Ctor(..), did) => this.parent(did), |
| _ => res.opt_def_id(), |
| }; |
| |
| if child_accessible { |
| // Remove invisible match if exists |
| if let Some(idx) = candidates |
| .iter() |
| .position(|v: &ImportSuggestion| v.did == did && !v.accessible) |
| { |
| candidates.remove(idx); |
| } |
| } |
| |
| if candidates.iter().all(|v: &ImportSuggestion| v.did != did) { |
| candidates.push(ImportSuggestion { |
| did, |
| descr: res.descr(), |
| path, |
| accessible: child_accessible, |
| }); |
| } |
| } |
| } |
| |
| // collect submodules to explore |
| if let Some(module) = name_binding.module() { |
| // form the path |
| let mut path_segments = path_segments.clone(); |
| path_segments.push(ast::PathSegment::from_ident(ident)); |
| |
| let is_extern_crate_that_also_appears_in_prelude = |
| name_binding.is_extern_crate() && lookup_ident.span.rust_2018(); |
| |
| if !is_extern_crate_that_also_appears_in_prelude { |
| // add the module to the lookup |
| if seen_modules.insert(module.def_id().unwrap()) { |
| if via_import { &mut worklist_via_import } else { &mut worklist } |
| .push((module, path_segments, child_accessible)); |
| } |
| } |
| } |
| }) |
| } |
| |
| // If only some candidates are accessible, take just them |
| if !candidates.iter().all(|v: &ImportSuggestion| !v.accessible) { |
| candidates = candidates.into_iter().filter(|x| x.accessible).collect(); |
| } |
| |
| candidates |
| } |
| |
| /// When name resolution fails, this method can be used to look up candidate |
| /// entities with the expected name. It allows filtering them using the |
| /// supplied predicate (which should be used to only accept the types of |
| /// definitions expected, e.g., traits). The lookup spans across all crates. |
| /// |
| /// N.B., the method does not look into imports, but this is not a problem, |
| /// since we report the definitions (thus, the de-aliased imports). |
| crate fn lookup_import_candidates<FilterFn>( |
| &mut self, |
| lookup_ident: Ident, |
| namespace: Namespace, |
| parent_scope: &ParentScope<'a>, |
| filter_fn: FilterFn, |
| ) -> Vec<ImportSuggestion> |
| where |
| FilterFn: Fn(Res) -> bool, |
| { |
| let mut suggestions = self.lookup_import_candidates_from_module( |
| lookup_ident, |
| namespace, |
| parent_scope, |
| self.graph_root, |
| Ident::with_dummy_span(kw::Crate), |
| &filter_fn, |
| ); |
| |
| if lookup_ident.span.rust_2018() { |
| let extern_prelude_names = self.extern_prelude.clone(); |
| for (ident, _) in extern_prelude_names.into_iter() { |
| if ident.span.from_expansion() { |
| // Idents are adjusted to the root context before being |
| // resolved in the extern prelude, so reporting this to the |
| // user is no help. This skips the injected |
| // `extern crate std` in the 2018 edition, which would |
| // otherwise cause duplicate suggestions. |
| continue; |
| } |
| if let Some(crate_id) = self.crate_loader.maybe_process_path_extern(ident.name) { |
| let crate_root = |
| self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX }); |
| suggestions.extend(self.lookup_import_candidates_from_module( |
| lookup_ident, |
| namespace, |
| parent_scope, |
| crate_root, |
| ident, |
| &filter_fn, |
| )); |
| } |
| } |
| } |
| |
| suggestions |
| } |
| |
| crate fn unresolved_macro_suggestions( |
| &mut self, |
| err: &mut DiagnosticBuilder<'a>, |
| macro_kind: MacroKind, |
| parent_scope: &ParentScope<'a>, |
| ident: Ident, |
| ) { |
| let is_expected = &|res: Res| res.macro_kind() == Some(macro_kind); |
| let suggestion = self.early_lookup_typo_candidate( |
| ScopeSet::Macro(macro_kind), |
| parent_scope, |
| ident, |
| is_expected, |
| ); |
| self.add_typo_suggestion(err, suggestion, ident.span); |
| |
| let import_suggestions = |
| self.lookup_import_candidates(ident, Namespace::MacroNS, parent_scope, |res| { |
| matches!(res, Res::Def(DefKind::Macro(MacroKind::Bang), _)) |
| }); |
| show_candidates(err, None, &import_suggestions, false, true); |
| |
| if macro_kind == MacroKind::Derive && (ident.name == sym::Send || ident.name == sym::Sync) { |
| let msg = format!("unsafe traits like `{}` should be implemented explicitly", ident); |
| err.span_note(ident.span, &msg); |
| } |
| if self.macro_names.contains(&ident.normalize_to_macros_2_0()) { |
| err.help("have you added the `#[macro_use]` on the module/import?"); |
| } |
| } |
| |
| crate fn add_typo_suggestion( |
| &self, |
| err: &mut DiagnosticBuilder<'_>, |
| suggestion: Option<TypoSuggestion>, |
| span: Span, |
| ) -> bool { |
| let suggestion = match suggestion { |
| None => return false, |
| // We shouldn't suggest underscore. |
| Some(suggestion) if suggestion.candidate == kw::Underscore => return false, |
| Some(suggestion) => suggestion, |
| }; |
| let def_span = suggestion.res.opt_def_id().and_then(|def_id| match def_id.krate { |
| LOCAL_CRATE => self.opt_span(def_id), |
| _ => Some( |
| self.session |
| .source_map() |
| .guess_head_span(self.cstore().get_span_untracked(def_id, self.session)), |
| ), |
| }); |
| if let Some(def_span) = def_span { |
| if span.overlaps(def_span) { |
| // Don't suggest typo suggestion for itself like in the following: |
| // error[E0423]: expected function, tuple struct or tuple variant, found struct `X` |
| // --> $DIR/issue-64792-bad-unicode-ctor.rs:3:14 |
| // | |
| // LL | struct X {} |
| // | ----------- `X` defined here |
| // LL | |
| // LL | const Y: X = X("ö"); |
| // | -------------^^^^^^- similarly named constant `Y` defined here |
| // | |
| // help: use struct literal syntax instead |
| // | |
| // LL | const Y: X = X {}; |
| // | ^^^^ |
| // help: a constant with a similar name exists |
| // | |
| // LL | const Y: X = Y("ö"); |
| // | ^ |
| return false; |
| } |
| err.span_label( |
| self.session.source_map().guess_head_span(def_span), |
| &format!( |
| "similarly named {} `{}` defined here", |
| suggestion.res.descr(), |
| suggestion.candidate.as_str(), |
| ), |
| ); |
| } |
| let msg = format!( |
| "{} {} with a similar name exists", |
| suggestion.res.article(), |
| suggestion.res.descr() |
| ); |
| err.span_suggestion( |
| span, |
| &msg, |
| suggestion.candidate.to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| true |
| } |
| |
| fn binding_description(&self, b: &NameBinding<'_>, ident: Ident, from_prelude: bool) -> String { |
| let res = b.res(); |
| if b.span.is_dummy() { |
| // These already contain the "built-in" prefix or look bad with it. |
| let add_built_in = |
| !matches!(b.res(), Res::NonMacroAttr(..) | Res::PrimTy(..) | Res::ToolMod); |
| let (built_in, from) = if from_prelude { |
| ("", " from prelude") |
| } else if b.is_extern_crate() |
| && !b.is_import() |
| && self.session.opts.externs.get(&ident.as_str()).is_some() |
| { |
| ("", " passed with `--extern`") |
| } else if add_built_in { |
| (" built-in", "") |
| } else { |
| ("", "") |
| }; |
| |
| let a = if built_in.is_empty() { res.article() } else { "a" }; |
| format!("{a}{built_in} {thing}{from}", thing = res.descr()) |
| } else { |
| let introduced = if b.is_import() { "imported" } else { "defined" }; |
| format!("the {thing} {introduced} here", thing = res.descr()) |
| } |
| } |
| |
| crate fn report_ambiguity_error(&self, ambiguity_error: &AmbiguityError<'_>) { |
| let AmbiguityError { kind, ident, b1, b2, misc1, misc2 } = *ambiguity_error; |
| let (b1, b2, misc1, misc2, swapped) = if b2.span.is_dummy() && !b1.span.is_dummy() { |
| // We have to print the span-less alternative first, otherwise formatting looks bad. |
| (b2, b1, misc2, misc1, true) |
| } else { |
| (b1, b2, misc1, misc2, false) |
| }; |
| |
| let mut err = struct_span_err!( |
| self.session, |
| ident.span, |
| E0659, |
| "`{ident}` is ambiguous ({why})", |
| why = kind.descr() |
| ); |
| err.span_label(ident.span, "ambiguous name"); |
| |
| let mut could_refer_to = |b: &NameBinding<'_>, misc: AmbiguityErrorMisc, also: &str| { |
| let what = self.binding_description(b, ident, misc == AmbiguityErrorMisc::FromPrelude); |
| let note_msg = format!("`{ident}` could{also} refer to {what}"); |
| |
| let thing = b.res().descr(); |
| let mut help_msgs = Vec::new(); |
| if b.is_glob_import() |
| && (kind == AmbiguityKind::GlobVsGlob |
| || kind == AmbiguityKind::GlobVsExpanded |
| || kind == AmbiguityKind::GlobVsOuter && swapped != also.is_empty()) |
| { |
| help_msgs.push(format!( |
| "consider adding an explicit import of `{ident}` to disambiguate" |
| )) |
| } |
| if b.is_extern_crate() && ident.span.rust_2018() { |
| help_msgs.push(format!("use `::{ident}` to refer to this {thing} unambiguously")) |
| } |
| if misc == AmbiguityErrorMisc::SuggestCrate { |
| help_msgs |
| .push(format!("use `crate::{ident}` to refer to this {thing} unambiguously")) |
| } else if misc == AmbiguityErrorMisc::SuggestSelf { |
| help_msgs |
| .push(format!("use `self::{ident}` to refer to this {thing} unambiguously")) |
| } |
| |
| err.span_note(b.span, ¬e_msg); |
| for (i, help_msg) in help_msgs.iter().enumerate() { |
| let or = if i == 0 { "" } else { "or " }; |
| err.help(&format!("{}{}", or, help_msg)); |
| } |
| }; |
| |
| could_refer_to(b1, misc1, ""); |
| could_refer_to(b2, misc2, " also"); |
| err.emit(); |
| } |
| |
| /// If the binding refers to a tuple struct constructor with fields, |
| /// returns the span of its fields. |
| fn ctor_fields_span(&self, binding: &NameBinding<'_>) -> Option<Span> { |
| if let NameBindingKind::Res( |
| Res::Def(DefKind::Ctor(CtorOf::Struct, CtorKind::Fn), ctor_def_id), |
| _, |
| ) = binding.kind |
| { |
| let def_id = self.parent(ctor_def_id).expect("no parent for a constructor"); |
| let fields = self.field_names.get(&def_id)?; |
| return fields.iter().map(|name| name.span).reduce(Span::to); // None for `struct Foo()` |
| } |
| None |
| } |
| |
| crate fn report_privacy_error(&self, privacy_error: &PrivacyError<'_>) { |
| let PrivacyError { ident, binding, .. } = *privacy_error; |
| |
| let res = binding.res(); |
| let ctor_fields_span = self.ctor_fields_span(binding); |
| let plain_descr = res.descr().to_string(); |
| let nonimport_descr = |
| if ctor_fields_span.is_some() { plain_descr + " constructor" } else { plain_descr }; |
| let import_descr = nonimport_descr.clone() + " import"; |
| let get_descr = |
| |b: &NameBinding<'_>| if b.is_import() { &import_descr } else { &nonimport_descr }; |
| |
| // Print the primary message. |
| let descr = get_descr(binding); |
| let mut err = |
| struct_span_err!(self.session, ident.span, E0603, "{} `{}` is private", descr, ident); |
| err.span_label(ident.span, &format!("private {}", descr)); |
| if let Some(span) = ctor_fields_span { |
| err.span_label(span, "a constructor is private if any of the fields is private"); |
| } |
| |
| // Print the whole import chain to make it easier to see what happens. |
| let first_binding = binding; |
| let mut next_binding = Some(binding); |
| let mut next_ident = ident; |
| while let Some(binding) = next_binding { |
| let name = next_ident; |
| next_binding = match binding.kind { |
| _ if res == Res::Err => None, |
| NameBindingKind::Import { binding, import, .. } => match import.kind { |
| _ if binding.span.is_dummy() => None, |
| ImportKind::Single { source, .. } => { |
| next_ident = source; |
| Some(binding) |
| } |
| ImportKind::Glob { .. } | ImportKind::MacroUse => Some(binding), |
| ImportKind::ExternCrate { .. } => None, |
| }, |
| _ => None, |
| }; |
| |
| let first = ptr::eq(binding, first_binding); |
| let msg = format!( |
| "{and_refers_to}the {item} `{name}`{which} is defined here{dots}", |
| and_refers_to = if first { "" } else { "...and refers to " }, |
| item = get_descr(binding), |
| which = if first { "" } else { " which" }, |
| dots = if next_binding.is_some() { "..." } else { "" }, |
| ); |
| let def_span = self.session.source_map().guess_head_span(binding.span); |
| let mut note_span = MultiSpan::from_span(def_span); |
| if !first && binding.vis == ty::Visibility::Public { |
| note_span.push_span_label(def_span, "consider importing it directly".into()); |
| } |
| err.span_note(note_span, &msg); |
| } |
| |
| err.emit(); |
| } |
| } |
| |
| impl<'a, 'b> ImportResolver<'a, 'b> { |
| /// Adds suggestions for a path that cannot be resolved. |
| pub(crate) fn make_path_suggestion( |
| &mut self, |
| span: Span, |
| mut path: Vec<Segment>, |
| parent_scope: &ParentScope<'b>, |
| ) -> Option<(Vec<Segment>, Vec<String>)> { |
| debug!("make_path_suggestion: span={:?} path={:?}", span, path); |
| |
| match (path.get(0), path.get(1)) { |
| // `{{root}}::ident::...` on both editions. |
| // On 2015 `{{root}}` is usually added implicitly. |
| (Some(fst), Some(snd)) |
| if fst.ident.name == kw::PathRoot && !snd.ident.is_path_segment_keyword() => {} |
| // `ident::...` on 2018. |
| (Some(fst), _) |
| if fst.ident.span.rust_2018() && !fst.ident.is_path_segment_keyword() => |
| { |
| // Insert a placeholder that's later replaced by `self`/`super`/etc. |
| path.insert(0, Segment::from_ident(Ident::invalid())); |
| } |
| _ => return None, |
| } |
| |
| self.make_missing_self_suggestion(span, path.clone(), parent_scope) |
| .or_else(|| self.make_missing_crate_suggestion(span, path.clone(), parent_scope)) |
| .or_else(|| self.make_missing_super_suggestion(span, path.clone(), parent_scope)) |
| .or_else(|| self.make_external_crate_suggestion(span, path, parent_scope)) |
| } |
| |
| /// Suggest a missing `self::` if that resolves to an correct module. |
| /// |
| /// ```text |
| /// | |
| /// LL | use foo::Bar; |
| /// | ^^^ did you mean `self::foo`? |
| /// ``` |
| fn make_missing_self_suggestion( |
| &mut self, |
| span: Span, |
| mut path: Vec<Segment>, |
| parent_scope: &ParentScope<'b>, |
| ) -> Option<(Vec<Segment>, Vec<String>)> { |
| // Replace first ident with `self` and check if that is valid. |
| path[0].ident.name = kw::SelfLower; |
| let result = self.r.resolve_path(&path, None, parent_scope, false, span, CrateLint::No); |
| debug!("make_missing_self_suggestion: path={:?} result={:?}", path, result); |
| if let PathResult::Module(..) = result { Some((path, Vec::new())) } else { None } |
| } |
| |
| /// Suggests a missing `crate::` if that resolves to an correct module. |
| /// |
| /// ```text |
| /// | |
| /// LL | use foo::Bar; |
| /// | ^^^ did you mean `crate::foo`? |
| /// ``` |
| fn make_missing_crate_suggestion( |
| &mut self, |
| span: Span, |
| mut path: Vec<Segment>, |
| parent_scope: &ParentScope<'b>, |
| ) -> Option<(Vec<Segment>, Vec<String>)> { |
| // Replace first ident with `crate` and check if that is valid. |
| path[0].ident.name = kw::Crate; |
| let result = self.r.resolve_path(&path, None, parent_scope, false, span, CrateLint::No); |
| debug!("make_missing_crate_suggestion: path={:?} result={:?}", path, result); |
| if let PathResult::Module(..) = result { |
| Some(( |
| path, |
| vec![ |
| "`use` statements changed in Rust 2018; read more at \ |
| <https://doc.rust-lang.org/edition-guide/rust-2018/module-system/path-\ |
| clarity.html>" |
| .to_string(), |
| ], |
| )) |
| } else { |
| None |
| } |
| } |
| |
| /// Suggests a missing `super::` if that resolves to an correct module. |
| /// |
| /// ```text |
| /// | |
| /// LL | use foo::Bar; |
| /// | ^^^ did you mean `super::foo`? |
| /// ``` |
| fn make_missing_super_suggestion( |
| &mut self, |
| span: Span, |
| mut path: Vec<Segment>, |
| parent_scope: &ParentScope<'b>, |
| ) -> Option<(Vec<Segment>, Vec<String>)> { |
| // Replace first ident with `crate` and check if that is valid. |
| path[0].ident.name = kw::Super; |
| let result = self.r.resolve_path(&path, None, parent_scope, false, span, CrateLint::No); |
| debug!("make_missing_super_suggestion: path={:?} result={:?}", path, result); |
| if let PathResult::Module(..) = result { Some((path, Vec::new())) } else { None } |
| } |
| |
| /// Suggests a missing external crate name if that resolves to an correct module. |
| /// |
| /// ```text |
| /// | |
| /// LL | use foobar::Baz; |
| /// | ^^^^^^ did you mean `baz::foobar`? |
| /// ``` |
| /// |
| /// Used when importing a submodule of an external crate but missing that crate's |
| /// name as the first part of path. |
| fn make_external_crate_suggestion( |
| &mut self, |
| span: Span, |
| mut path: Vec<Segment>, |
| parent_scope: &ParentScope<'b>, |
| ) -> Option<(Vec<Segment>, Vec<String>)> { |
| if path[1].ident.span.rust_2015() { |
| return None; |
| } |
| |
| // Sort extern crate names in reverse order to get |
| // 1) some consistent ordering for emitted diagnostics, and |
| // 2) `std` suggestions before `core` suggestions. |
| let mut extern_crate_names = |
| self.r.extern_prelude.iter().map(|(ident, _)| ident.name).collect::<Vec<_>>(); |
| extern_crate_names.sort_by_key(|name| Reverse(name.as_str())); |
| |
| for name in extern_crate_names.into_iter() { |
| // Replace first ident with a crate name and check if that is valid. |
| path[0].ident.name = name; |
| let result = self.r.resolve_path(&path, None, parent_scope, false, span, CrateLint::No); |
| debug!( |
| "make_external_crate_suggestion: name={:?} path={:?} result={:?}", |
| name, path, result |
| ); |
| if let PathResult::Module(..) = result { |
| return Some((path, Vec::new())); |
| } |
| } |
| |
| None |
| } |
| |
| /// Suggests importing a macro from the root of the crate rather than a module within |
| /// the crate. |
| /// |
| /// ```text |
| /// help: a macro with this name exists at the root of the crate |
| /// | |
| /// LL | use issue_59764::makro; |
| /// | ^^^^^^^^^^^^^^^^^^ |
| /// | |
| /// = note: this could be because a macro annotated with `#[macro_export]` will be exported |
| /// at the root of the crate instead of the module where it is defined |
| /// ``` |
| pub(crate) fn check_for_module_export_macro( |
| &mut self, |
| import: &'b Import<'b>, |
| module: ModuleOrUniformRoot<'b>, |
| ident: Ident, |
| ) -> Option<(Option<Suggestion>, Vec<String>)> { |
| let mut crate_module = if let ModuleOrUniformRoot::Module(module) = module { |
| module |
| } else { |
| return None; |
| }; |
| |
| while let Some(parent) = crate_module.parent { |
| crate_module = parent; |
| } |
| |
| if ModuleOrUniformRoot::same_def(ModuleOrUniformRoot::Module(crate_module), module) { |
| // Don't make a suggestion if the import was already from the root of the |
| // crate. |
| return None; |
| } |
| |
| let resolutions = self.r.resolutions(crate_module).borrow(); |
| let resolution = resolutions.get(&self.r.new_key(ident, MacroNS))?; |
| let binding = resolution.borrow().binding()?; |
| if let Res::Def(DefKind::Macro(MacroKind::Bang), _) = binding.res() { |
| let module_name = crate_module.kind.name().unwrap(); |
| let import_snippet = match import.kind { |
| ImportKind::Single { source, target, .. } if source != target => { |
| format!("{} as {}", source, target) |
| } |
| _ => format!("{}", ident), |
| }; |
| |
| let mut corrections: Vec<(Span, String)> = Vec::new(); |
| if !import.is_nested() { |
| // Assume this is the easy case of `use issue_59764::foo::makro;` and just remove |
| // intermediate segments. |
| corrections.push((import.span, format!("{}::{}", module_name, import_snippet))); |
| } else { |
| // Find the binding span (and any trailing commas and spaces). |
| // ie. `use a::b::{c, d, e};` |
| // ^^^ |
| let (found_closing_brace, binding_span) = find_span_of_binding_until_next_binding( |
| self.r.session, |
| import.span, |
| import.use_span, |
| ); |
| debug!( |
| "check_for_module_export_macro: found_closing_brace={:?} binding_span={:?}", |
| found_closing_brace, binding_span |
| ); |
| |
| let mut removal_span = binding_span; |
| if found_closing_brace { |
| // If the binding span ended with a closing brace, as in the below example: |
| // ie. `use a::b::{c, d};` |
| // ^ |
| // Then expand the span of characters to remove to include the previous |
| // binding's trailing comma. |
| // ie. `use a::b::{c, d};` |
| // ^^^ |
| if let Some(previous_span) = |
| extend_span_to_previous_binding(self.r.session, binding_span) |
| { |
| debug!("check_for_module_export_macro: previous_span={:?}", previous_span); |
| removal_span = removal_span.with_lo(previous_span.lo()); |
| } |
| } |
| debug!("check_for_module_export_macro: removal_span={:?}", removal_span); |
| |
| // Remove the `removal_span`. |
| corrections.push((removal_span, "".to_string())); |
| |
| // Find the span after the crate name and if it has nested imports immediatately |
| // after the crate name already. |
| // ie. `use a::b::{c, d};` |
| // ^^^^^^^^^ |
| // or `use a::{b, c, d}};` |
| // ^^^^^^^^^^^ |
| let (has_nested, after_crate_name) = find_span_immediately_after_crate_name( |
| self.r.session, |
| module_name, |
| import.use_span, |
| ); |
| debug!( |
| "check_for_module_export_macro: has_nested={:?} after_crate_name={:?}", |
| has_nested, after_crate_name |
| ); |
| |
| let source_map = self.r.session.source_map(); |
| |
| // Add the import to the start, with a `{` if required. |
| let start_point = source_map.start_point(after_crate_name); |
| if let Ok(start_snippet) = source_map.span_to_snippet(start_point) { |
| corrections.push(( |
| start_point, |
| if has_nested { |
| // In this case, `start_snippet` must equal '{'. |
| format!("{}{}, ", start_snippet, import_snippet) |
| } else { |
| // In this case, add a `{`, then the moved import, then whatever |
| // was there before. |
| format!("{{{}, {}", import_snippet, start_snippet) |
| }, |
| )); |
| } |
| |
| // Add a `};` to the end if nested, matching the `{` added at the start. |
| if !has_nested { |
| corrections.push((source_map.end_point(after_crate_name), "};".to_string())); |
| } |
| } |
| |
| let suggestion = Some(( |
| corrections, |
| String::from("a macro with this name exists at the root of the crate"), |
| Applicability::MaybeIncorrect, |
| )); |
| let note = vec![ |
| "this could be because a macro annotated with `#[macro_export]` will be exported \ |
| at the root of the crate instead of the module where it is defined" |
| .to_string(), |
| ]; |
| Some((suggestion, note)) |
| } else { |
| None |
| } |
| } |
| } |
| |
| /// Given a `binding_span` of a binding within a use statement: |
| /// |
| /// ``` |
| /// use foo::{a, b, c}; |
| /// ^ |
| /// ``` |
| /// |
| /// then return the span until the next binding or the end of the statement: |
| /// |
| /// ``` |
| /// use foo::{a, b, c}; |
| /// ^^^ |
| /// ``` |
| pub(crate) fn find_span_of_binding_until_next_binding( |
| sess: &Session, |
| binding_span: Span, |
| use_span: Span, |
| ) -> (bool, Span) { |
| let source_map = sess.source_map(); |
| |
| // Find the span of everything after the binding. |
| // ie. `a, e};` or `a};` |
| let binding_until_end = binding_span.with_hi(use_span.hi()); |
| |
| // Find everything after the binding but not including the binding. |
| // ie. `, e};` or `};` |
| let after_binding_until_end = binding_until_end.with_lo(binding_span.hi()); |
| |
| // Keep characters in the span until we encounter something that isn't a comma or |
| // whitespace. |
| // ie. `, ` or ``. |
| // |
| // Also note whether a closing brace character was encountered. If there |
| // was, then later go backwards to remove any trailing commas that are left. |
| let mut found_closing_brace = false; |
| let after_binding_until_next_binding = |
| source_map.span_take_while(after_binding_until_end, |&ch| { |
| if ch == '}' { |
| found_closing_brace = true; |
| } |
| ch == ' ' || ch == ',' |
| }); |
| |
| // Combine the two spans. |
| // ie. `a, ` or `a`. |
| // |
| // Removing these would leave `issue_52891::{d, e};` or `issue_52891::{d, e, };` |
| let span = binding_span.with_hi(after_binding_until_next_binding.hi()); |
| |
| (found_closing_brace, span) |
| } |
| |
| /// Given a `binding_span`, return the span through to the comma or opening brace of the previous |
| /// binding. |
| /// |
| /// ``` |
| /// use foo::a::{a, b, c}; |
| /// ^^--- binding span |
| /// | |
| /// returned span |
| /// |
| /// use foo::{a, b, c}; |
| /// --- binding span |
| /// ``` |
| pub(crate) fn extend_span_to_previous_binding(sess: &Session, binding_span: Span) -> Option<Span> { |
| let source_map = sess.source_map(); |
| |
| // `prev_source` will contain all of the source that came before the span. |
| // Then split based on a command and take the first (ie. closest to our span) |
| // snippet. In the example, this is a space. |
| let prev_source = source_map.span_to_prev_source(binding_span).ok()?; |
| |
| let prev_comma = prev_source.rsplit(',').collect::<Vec<_>>(); |
| let prev_starting_brace = prev_source.rsplit('{').collect::<Vec<_>>(); |
| if prev_comma.len() <= 1 || prev_starting_brace.len() <= 1 { |
| return None; |
| } |
| |
| let prev_comma = prev_comma.first().unwrap(); |
| let prev_starting_brace = prev_starting_brace.first().unwrap(); |
| |
| // If the amount of source code before the comma is greater than |
| // the amount of source code before the starting brace then we've only |
| // got one item in the nested item (eg. `issue_52891::{self}`). |
| if prev_comma.len() > prev_starting_brace.len() { |
| return None; |
| } |
| |
| Some(binding_span.with_lo(BytePos( |
| // Take away the number of bytes for the characters we've found and an |
| // extra for the comma. |
| binding_span.lo().0 - (prev_comma.as_bytes().len() as u32) - 1, |
| ))) |
| } |
| |
| /// Given a `use_span` of a binding within a use statement, returns the highlighted span and if |
| /// it is a nested use tree. |
| /// |
| /// ``` |
| /// use foo::a::{b, c}; |
| /// ^^^^^^^^^^ // false |
| /// |
| /// use foo::{a, b, c}; |
| /// ^^^^^^^^^^ // true |
| /// |
| /// use foo::{a, b::{c, d}}; |
| /// ^^^^^^^^^^^^^^^ // true |
| /// ``` |
| fn find_span_immediately_after_crate_name( |
| sess: &Session, |
| module_name: Symbol, |
| use_span: Span, |
| ) -> (bool, Span) { |
| debug!( |
| "find_span_immediately_after_crate_name: module_name={:?} use_span={:?}", |
| module_name, use_span |
| ); |
| let source_map = sess.source_map(); |
| |
| // Using `use issue_59764::foo::{baz, makro};` as an example throughout.. |
| let mut num_colons = 0; |
| // Find second colon.. `use issue_59764:` |
| let until_second_colon = source_map.span_take_while(use_span, |c| { |
| if *c == ':' { |
| num_colons += 1; |
| } |
| !matches!(c, ':' if num_colons == 2) |
| }); |
| // Find everything after the second colon.. `foo::{baz, makro};` |
| let from_second_colon = use_span.with_lo(until_second_colon.hi() + BytePos(1)); |
| |
| let mut found_a_non_whitespace_character = false; |
| // Find the first non-whitespace character in `from_second_colon`.. `f` |
| let after_second_colon = source_map.span_take_while(from_second_colon, |c| { |
| if found_a_non_whitespace_character { |
| return false; |
| } |
| if !c.is_whitespace() { |
| found_a_non_whitespace_character = true; |
| } |
| true |
| }); |
| |
| // Find the first `{` in from_second_colon.. `foo::{` |
| let next_left_bracket = source_map.span_through_char(from_second_colon, '{'); |
| |
| (next_left_bracket == after_second_colon, from_second_colon) |
| } |
| |
| /// When an entity with a given name is not available in scope, we search for |
| /// entities with that name in all crates. This method allows outputting the |
| /// results of this search in a programmer-friendly way |
| crate fn show_candidates( |
| err: &mut DiagnosticBuilder<'_>, |
| // This is `None` if all placement locations are inside expansions |
| use_placement_span: Option<Span>, |
| candidates: &[ImportSuggestion], |
| instead: bool, |
| found_use: bool, |
| ) { |
| if candidates.is_empty() { |
| return; |
| } |
| |
| // we want consistent results across executions, but candidates are produced |
| // by iterating through a hash map, so make sure they are ordered: |
| let mut path_strings: Vec<_> = |
| candidates.iter().map(|c| path_names_to_string(&c.path)).collect(); |
| |
| path_strings.sort(); |
| path_strings.dedup(); |
| |
| let (determiner, kind) = if candidates.len() == 1 { |
| ("this", candidates[0].descr) |
| } else { |
| ("one of these", "items") |
| }; |
| |
| let instead = if instead { " instead" } else { "" }; |
| let mut msg = format!("consider importing {} {}{}", determiner, kind, instead); |
| |
| if let Some(span) = use_placement_span { |
| for candidate in &mut path_strings { |
| // produce an additional newline to separate the new use statement |
| // from the directly following item. |
| let additional_newline = if found_use { "" } else { "\n" }; |
| *candidate = format!("use {};\n{}", candidate, additional_newline); |
| } |
| |
| err.span_suggestions(span, &msg, path_strings.into_iter(), Applicability::Unspecified); |
| } else { |
| msg.push(':'); |
| |
| for candidate in path_strings { |
| msg.push('\n'); |
| msg.push_str(&candidate); |
| } |
| |
| err.note(&msg); |
| } |
| } |
