1149 lines
49 KiB
Rust
1149 lines
49 KiB
Rust
use std::cmp::Reverse;
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use errors::{Applicability, DiagnosticBuilder, DiagnosticId};
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use log::debug;
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use rustc::bug;
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use rustc::hir::def::{self, DefKind, NonMacroAttrKind};
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use rustc::hir::def::Namespace::{self, *};
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use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId};
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use rustc::session::Session;
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use rustc::ty::{self, DefIdTree};
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use rustc::util::nodemap::FxHashSet;
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use syntax::ast::{self, Ident, Path};
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use syntax_expand::base::MacroKind;
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use syntax::feature_gate::BUILTIN_ATTRIBUTES;
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use syntax::source_map::SourceMap;
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use syntax::struct_span_err;
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use syntax::symbol::{Symbol, kw};
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use syntax::util::lev_distance::find_best_match_for_name;
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use syntax_pos::{BytePos, Span, MultiSpan};
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use crate::resolve_imports::{ImportDirective, ImportDirectiveSubclass, ImportResolver};
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use crate::{path_names_to_string, KNOWN_TOOLS};
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use crate::{BindingError, CrateLint, HasGenericParams, LegacyScope, Module, ModuleOrUniformRoot};
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use crate::{PathResult, ParentScope, ResolutionError, Resolver, Scope, ScopeSet, Segment};
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type Res = def::Res<ast::NodeId>;
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/// A vector of spans and replacements, a message and applicability.
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crate type Suggestion = (Vec<(Span, String)>, String, Applicability);
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crate struct TypoSuggestion {
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pub candidate: Symbol,
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pub res: Res,
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}
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impl TypoSuggestion {
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crate fn from_res(candidate: Symbol, res: Res) -> TypoSuggestion {
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TypoSuggestion { candidate, res }
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}
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}
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/// A free importable items suggested in case of resolution failure.
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crate struct ImportSuggestion {
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pub did: Option<DefId>,
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pub path: Path,
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}
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/// Adjust the impl span so that just the `impl` keyword is taken by removing
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/// everything after `<` (`"impl<T> Iterator for A<T> {}" -> "impl"`) and
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/// everything after the first whitespace (`"impl Iterator for A" -> "impl"`).
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///
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/// *Attention*: the method used is very fragile since it essentially duplicates the work of the
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/// parser. If you need to use this function or something similar, please consider updating the
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/// `source_map` functions and this function to something more robust.
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fn reduce_impl_span_to_impl_keyword(cm: &SourceMap, impl_span: Span) -> Span {
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let impl_span = cm.span_until_char(impl_span, '<');
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let impl_span = cm.span_until_whitespace(impl_span);
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impl_span
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}
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crate fn add_typo_suggestion(
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err: &mut DiagnosticBuilder<'_>, suggestion: Option<TypoSuggestion>, span: Span
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) -> bool {
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if let Some(suggestion) = suggestion {
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let msg = format!(
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"{} {} with a similar name exists", suggestion.res.article(), suggestion.res.descr()
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);
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err.span_suggestion(
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span, &msg, suggestion.candidate.to_string(), Applicability::MaybeIncorrect
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);
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return true;
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}
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false
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}
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impl<'a> Resolver<'a> {
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crate fn add_module_candidates(
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&mut self,
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module: Module<'a>,
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names: &mut Vec<TypoSuggestion>,
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filter_fn: &impl Fn(Res) -> bool,
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) {
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for (key, resolution) in self.resolutions(module).borrow().iter() {
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if let Some(binding) = resolution.borrow().binding {
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let res = binding.res();
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if filter_fn(res) {
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names.push(TypoSuggestion::from_res(key.ident.name, res));
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}
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}
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}
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}
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/// Combines an error with provided span and emits it.
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///
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/// This takes the error provided, combines it with the span and any additional spans inside the
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/// error and emits it.
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crate fn report_error(&self, span: Span, resolution_error: ResolutionError<'_>) {
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self.into_struct_error(span, resolution_error).emit();
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}
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crate fn into_struct_error(
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&self, span: Span, resolution_error: ResolutionError<'_>
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) -> DiagnosticBuilder<'_> {
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match resolution_error {
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ResolutionError::GenericParamsFromOuterFunction(outer_res, has_generic_params) => {
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let mut err = struct_span_err!(self.session,
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span,
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E0401,
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"can't use generic parameters from outer function",
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);
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err.span_label(span, format!("use of generic parameter from outer function"));
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let cm = self.session.source_map();
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match outer_res {
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Res::SelfTy(maybe_trait_defid, maybe_impl_defid) => {
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if let Some(impl_span) = maybe_impl_defid.and_then(|def_id| {
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self.definitions.opt_span(def_id)
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}) {
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err.span_label(
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reduce_impl_span_to_impl_keyword(cm, impl_span),
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"`Self` type implicitly declared here, by this `impl`",
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);
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}
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match (maybe_trait_defid, maybe_impl_defid) {
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(Some(_), None) => {
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err.span_label(span, "can't use `Self` here");
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}
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(_, Some(_)) => {
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err.span_label(span, "use a type here instead");
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}
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(None, None) => bug!("`impl` without trait nor type?"),
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}
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return err;
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},
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Res::Def(DefKind::TyParam, def_id) => {
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if let Some(span) = self.definitions.opt_span(def_id) {
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err.span_label(span, "type parameter from outer function");
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}
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}
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Res::Def(DefKind::ConstParam, def_id) => {
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if let Some(span) = self.definitions.opt_span(def_id) {
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err.span_label(span, "const parameter from outer function");
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}
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}
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_ => {
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bug!("GenericParamsFromOuterFunction should only be used with Res::SelfTy, \
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DefKind::TyParam");
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}
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}
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if has_generic_params == HasGenericParams::Yes {
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// Try to retrieve the span of the function signature and generate a new
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// message with a local type or const parameter.
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let sugg_msg = &format!("try using a local generic parameter instead");
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if let Some((sugg_span, snippet)) = cm.generate_local_type_param_snippet(span) {
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// Suggest the modification to the user
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err.span_suggestion(
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sugg_span,
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sugg_msg,
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snippet,
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Applicability::MachineApplicable,
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);
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} else if let Some(sp) = cm.generate_fn_name_span(span) {
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err.span_label(sp,
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format!("try adding a local generic parameter in this method instead"));
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} else {
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err.help(&format!("try using a local generic parameter instead"));
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}
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}
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err
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}
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ResolutionError::NameAlreadyUsedInParameterList(name, first_use_span) => {
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let mut err = struct_span_err!(
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self.session,
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span,
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E0403,
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"the name `{}` is already used for a generic \
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parameter in this item's generic parameters",
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name,
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);
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err.span_label(span, "already used");
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err.span_label(first_use_span, format!("first use of `{}`", name));
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err
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}
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ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
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let mut err = struct_span_err!(self.session,
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span,
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E0407,
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"method `{}` is not a member of trait `{}`",
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method,
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trait_);
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err.span_label(span, format!("not a member of trait `{}`", trait_));
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err
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}
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ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
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let mut err = struct_span_err!(self.session,
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span,
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E0437,
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"type `{}` is not a member of trait `{}`",
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type_,
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trait_);
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err.span_label(span, format!("not a member of trait `{}`", trait_));
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err
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}
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ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
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let mut err = struct_span_err!(self.session,
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span,
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E0438,
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"const `{}` is not a member of trait `{}`",
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const_,
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trait_);
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err.span_label(span, format!("not a member of trait `{}`", trait_));
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err
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}
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ResolutionError::VariableNotBoundInPattern(binding_error) => {
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let BindingError { name, target, origin, could_be_path } = binding_error;
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let target_sp = target.iter().copied().collect::<Vec<_>>();
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let origin_sp = origin.iter().copied().collect::<Vec<_>>();
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let msp = MultiSpan::from_spans(target_sp.clone());
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let msg = format!("variable `{}` is not bound in all patterns", name);
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let mut err = self.session.struct_span_err_with_code(
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msp,
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&msg,
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DiagnosticId::Error("E0408".into()),
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);
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for sp in target_sp {
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err.span_label(sp, format!("pattern doesn't bind `{}`", name));
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}
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for sp in origin_sp {
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err.span_label(sp, "variable not in all patterns");
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}
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if *could_be_path {
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let help_msg = format!(
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"if you meant to match on a variant or a `const` item, consider \
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making the path in the pattern qualified: `?::{}`",
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name,
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);
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err.span_help(span, &help_msg);
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}
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err
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}
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ResolutionError::VariableBoundWithDifferentMode(variable_name,
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first_binding_span) => {
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let mut err = struct_span_err!(self.session,
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span,
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E0409,
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"variable `{}` is bound in inconsistent \
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ways within the same match arm",
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variable_name);
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err.span_label(span, "bound in different ways");
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err.span_label(first_binding_span, "first binding");
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err
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}
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ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
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let mut err = struct_span_err!(self.session,
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span,
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E0415,
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"identifier `{}` is bound more than once in this parameter list",
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identifier);
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err.span_label(span, "used as parameter more than once");
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err
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}
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ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
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let mut err = struct_span_err!(self.session,
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span,
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E0416,
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"identifier `{}` is bound more than once in the same pattern",
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identifier);
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err.span_label(span, "used in a pattern more than once");
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err
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}
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ResolutionError::UndeclaredLabel(name, lev_candidate) => {
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let mut err = struct_span_err!(self.session,
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span,
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E0426,
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"use of undeclared label `{}`",
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name);
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if let Some(lev_candidate) = lev_candidate {
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err.span_suggestion(
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span,
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"a label with a similar name exists in this scope",
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lev_candidate.to_string(),
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Applicability::MaybeIncorrect,
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);
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} else {
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err.span_label(span, format!("undeclared label `{}`", name));
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}
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err
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}
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ResolutionError::SelfImportsOnlyAllowedWithin => {
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struct_span_err!(self.session,
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span,
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E0429,
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"{}",
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"`self` imports are only allowed within a { } list")
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}
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ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
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let mut err = struct_span_err!(self.session, span, E0430,
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"`self` import can only appear once in an import list");
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err.span_label(span, "can only appear once in an import list");
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err
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}
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ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
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let mut err = struct_span_err!(self.session, span, E0431,
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"`self` import can only appear in an import list with \
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a non-empty prefix");
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err.span_label(span, "can only appear in an import list with a non-empty prefix");
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err
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}
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ResolutionError::FailedToResolve { label, suggestion } => {
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let mut err = struct_span_err!(self.session, span, E0433,
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"failed to resolve: {}", &label);
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err.span_label(span, label);
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if let Some((suggestions, msg, applicability)) = suggestion {
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err.multipart_suggestion(&msg, suggestions, applicability);
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}
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err
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}
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ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
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let mut err = struct_span_err!(self.session,
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span,
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E0434,
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"{}",
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"can't capture dynamic environment in a fn item");
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err.help("use the `|| { ... }` closure form instead");
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err
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}
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ResolutionError::AttemptToUseNonConstantValueInConstant => {
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let mut err = struct_span_err!(self.session, span, E0435,
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"attempt to use a non-constant value in a constant");
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err.span_label(span, "non-constant value");
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err
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}
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ResolutionError::BindingShadowsSomethingUnacceptable(what_binding, name, binding) => {
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let res = binding.res();
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let shadows_what = res.descr();
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let mut err = struct_span_err!(self.session, span, E0530, "{}s cannot shadow {}s",
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what_binding, shadows_what);
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err.span_label(span, format!("cannot be named the same as {} {}",
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res.article(), shadows_what));
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let participle = if binding.is_import() { "imported" } else { "defined" };
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let msg = format!("the {} `{}` is {} here", shadows_what, name, participle);
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err.span_label(binding.span, msg);
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err
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}
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ResolutionError::ForwardDeclaredTyParam => {
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let mut err = struct_span_err!(self.session, span, E0128,
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"type parameters with a default cannot use \
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forward declared identifiers");
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err.span_label(
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span, "defaulted type parameters cannot be forward declared".to_string());
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err
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}
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ResolutionError::SelfInTyParamDefault => {
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let mut err = struct_span_err!(
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self.session,
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span,
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E0735,
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"type parameters cannot use `Self` in their defaults"
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);
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err.span_label(
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span, "`Self` in type parameter default".to_string());
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err
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}
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ResolutionError::ConstParamDependentOnTypeParam => {
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let mut err = struct_span_err!(
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self.session,
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span,
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E0671,
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"const parameters cannot depend on type parameters"
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);
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err.span_label(span, format!("const parameter depends on type parameter"));
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err
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}
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}
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}
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/// Lookup typo candidate in scope for a macro or import.
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fn early_lookup_typo_candidate(
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&mut self,
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scope_set: ScopeSet,
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parent_scope: &ParentScope<'a>,
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ident: Ident,
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filter_fn: &impl Fn(Res) -> bool,
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) -> Option<TypoSuggestion> {
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let mut suggestions = Vec::new();
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self.visit_scopes(scope_set, parent_scope, ident, |this, scope, use_prelude, _| {
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match scope {
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Scope::DeriveHelpers => {
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let res = Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper);
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if filter_fn(res) {
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for derive in parent_scope.derives {
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let parent_scope =
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&ParentScope { derives: &[], ..*parent_scope };
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if let Ok((Some(ext), _)) = this.resolve_macro_path(
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derive, Some(MacroKind::Derive), parent_scope, false, false
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) {
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suggestions.extend(ext.helper_attrs.iter().map(|name| {
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TypoSuggestion::from_res(*name, res)
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}));
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}
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}
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}
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}
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Scope::MacroRules(legacy_scope) => {
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if let LegacyScope::Binding(legacy_binding) = legacy_scope {
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let res = legacy_binding.binding.res();
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if filter_fn(res) {
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suggestions.push(
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TypoSuggestion::from_res(legacy_binding.ident.name, res)
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)
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}
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}
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}
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Scope::CrateRoot => {
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let root_ident = Ident::new(kw::PathRoot, ident.span);
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let root_module = this.resolve_crate_root(root_ident);
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this.add_module_candidates(root_module, &mut suggestions, filter_fn);
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}
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Scope::Module(module) => {
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this.add_module_candidates(module, &mut suggestions, filter_fn);
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}
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Scope::MacroUsePrelude => {
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suggestions.extend(this.macro_use_prelude.iter().filter_map(|(name, binding)| {
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let res = binding.res();
|
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if filter_fn(res) {
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Some(TypoSuggestion::from_res(*name, res))
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} else {
|
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None
|
|
}
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}));
|
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}
|
|
Scope::BuiltinAttrs => {
|
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let res = Res::NonMacroAttr(NonMacroAttrKind::Builtin);
|
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if filter_fn(res) {
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suggestions.extend(BUILTIN_ATTRIBUTES.iter().map(|(name, ..)| {
|
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TypoSuggestion::from_res(*name, res)
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|
}));
|
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}
|
|
}
|
|
Scope::LegacyPluginHelpers => {
|
|
let res = Res::NonMacroAttr(NonMacroAttrKind::LegacyPluginHelper);
|
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if filter_fn(res) {
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let plugin_attributes = this.session.plugin_attributes.borrow();
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suggestions.extend(plugin_attributes.iter().map(|(name, _)| {
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TypoSuggestion::from_res(*name, res)
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}));
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}
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}
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|
Scope::ExternPrelude => {
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suggestions.extend(this.extern_prelude.iter().filter_map(|(ident, _)| {
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let res = Res::Def(DefKind::Mod, DefId::local(CRATE_DEF_INDEX));
|
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if filter_fn(res) {
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Some(TypoSuggestion::from_res(ident.name, res))
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} else {
|
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None
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|
}
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}));
|
|
}
|
|
Scope::ToolPrelude => {
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|
let res = Res::NonMacroAttr(NonMacroAttrKind::Tool);
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suggestions.extend(KNOWN_TOOLS.iter().map(|name| {
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TypoSuggestion::from_res(*name, res)
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|
}));
|
|
}
|
|
Scope::StdLibPrelude => {
|
|
if let Some(prelude) = this.prelude {
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let mut tmp_suggestions = Vec::new();
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this.add_module_candidates(prelude, &mut tmp_suggestions, filter_fn);
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suggestions.extend(tmp_suggestions.into_iter().filter(|s| {
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use_prelude || this.is_builtin_macro(s.res)
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}));
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}
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}
|
|
Scope::BuiltinTypes => {
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|
let primitive_types = &this.primitive_type_table.primitive_types;
|
|
suggestions.extend(
|
|
primitive_types.iter().flat_map(|(name, prim_ty)| {
|
|
let res = Res::PrimTy(*prim_ty);
|
|
if filter_fn(res) {
|
|
Some(TypoSuggestion::from_res(*name, res))
|
|
} else {
|
|
None
|
|
}
|
|
})
|
|
)
|
|
}
|
|
}
|
|
|
|
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),
|
|
&ident.as_str(),
|
|
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,
|
|
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 not_local_module = crate_name.name != kw::Crate;
|
|
let mut worklist = vec![(start_module, Vec::<ast::PathSegment>::new(), not_local_module)];
|
|
|
|
while let Some((in_module,
|
|
path_segments,
|
|
in_module_is_extern)) = worklist.pop() {
|
|
// 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 imports entirely
|
|
if name_binding.is_import() && !name_binding.is_extern_crate() { return; }
|
|
// avoid non-importable candidates as well
|
|
if !name_binding.is_importable() { return; }
|
|
|
|
// collect results based on the filter function
|
|
if ident.name == lookup_ident.name && ns == namespace {
|
|
let res = name_binding.res();
|
|
if filter_fn(res) {
|
|
// create the path
|
|
let mut segms = path_segments.clone();
|
|
if lookup_ident.span.rust_2018() {
|
|
// crate-local absolute paths start with `crate::` in edition 2018
|
|
// FIXME: may also be stabilized for Rust 2015 (Issues #45477, #44660)
|
|
segms.insert(
|
|
0, ast::PathSegment::from_ident(crate_name)
|
|
);
|
|
}
|
|
|
|
segms.push(ast::PathSegment::from_ident(ident));
|
|
let path = Path {
|
|
span: name_binding.span,
|
|
segments: segms,
|
|
};
|
|
// the entity is accessible in the following cases:
|
|
// 1. if it's defined in the same crate, it's always
|
|
// accessible (since private entities can be made public)
|
|
// 2. if it's defined in another crate, it's accessible
|
|
// only if both the module is public and the entity is
|
|
// declared as public (due to pruning, we don't explore
|
|
// outside crate private modules => no need to check this)
|
|
if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
|
|
let did = match res {
|
|
Res::Def(DefKind::Ctor(..), did) => this.parent(did),
|
|
_ => res.opt_def_id(),
|
|
};
|
|
candidates.push(ImportSuggestion { did, path });
|
|
}
|
|
}
|
|
}
|
|
|
|
// collect submodules to explore
|
|
if let Some(module) = name_binding.module() {
|
|
// form the path
|
|
let mut path_segments = path_segments.clone();
|
|
path_segments.push(ast::PathSegment::from_ident(ident));
|
|
|
|
let is_extern_crate_that_also_appears_in_prelude =
|
|
name_binding.is_extern_crate() &&
|
|
lookup_ident.span.rust_2018();
|
|
|
|
let is_visible_to_user =
|
|
!in_module_is_extern || name_binding.vis == ty::Visibility::Public;
|
|
|
|
if !is_extern_crate_that_also_appears_in_prelude && is_visible_to_user {
|
|
// add the module to the lookup
|
|
let is_extern = in_module_is_extern || name_binding.is_extern_crate();
|
|
if seen_modules.insert(module.def_id().unwrap()) {
|
|
worklist.push((module, path_segments, is_extern));
|
|
}
|
|
}
|
|
}
|
|
})
|
|
}
|
|
|
|
candidates
|
|
}
|
|
|
|
/// When name resolution fails, this method can be used to look up candidate
|
|
/// entities with the expected name. It allows filtering them using the
|
|
/// supplied predicate (which should be used to only accept the types of
|
|
/// definitions expected, e.g., traits). The lookup spans across all crates.
|
|
///
|
|
/// N.B., the method does not look into imports, but this is not a problem,
|
|
/// since we report the definitions (thus, the de-aliased imports).
|
|
crate fn lookup_import_candidates<FilterFn>(
|
|
&mut self, lookup_ident: Ident, namespace: Namespace, filter_fn: FilterFn
|
|
) -> Vec<ImportSuggestion>
|
|
where FilterFn: Fn(Res) -> bool
|
|
{
|
|
let mut suggestions = self.lookup_import_candidates_from_module(
|
|
lookup_ident, namespace, self.graph_root, Ident::with_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,
|
|
ident.span) {
|
|
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, 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
|
|
);
|
|
add_typo_suggestion(err, suggestion, ident.span);
|
|
|
|
if macro_kind == MacroKind::Derive &&
|
|
(ident.as_str() == "Send" || ident.as_str() == "Sync") {
|
|
let msg = format!("unsafe traits like `{}` should be implemented explicitly", ident);
|
|
err.span_note(ident.span, &msg);
|
|
}
|
|
if self.macro_names.contains(&ident.modern()) {
|
|
err.help("have you added the `#[macro_use]` on the module/import?");
|
|
}
|
|
}
|
|
}
|
|
|
|
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.
|
|
///
|
|
/// ```
|
|
/// |
|
|
/// 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.
|
|
///
|
|
/// ```
|
|
/// |
|
|
/// 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.
|
|
///
|
|
/// ```
|
|
/// |
|
|
/// 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.
|
|
///
|
|
/// ```
|
|
/// |
|
|
/// 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 dignostics, 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.
|
|
///
|
|
/// ```
|
|
/// 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,
|
|
directive: &'b ImportDirective<'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 = match directive.subclass {
|
|
ImportDirectiveSubclass::SingleImport { source, target, .. } if source != target =>
|
|
format!("{} as {}", source, target),
|
|
_ => format!("{}", ident),
|
|
};
|
|
|
|
let mut corrections: Vec<(Span, String)> = Vec::new();
|
|
if !directive.is_nested() {
|
|
// Assume this is the easy case of `use issue_59764::foo::makro;` and just remove
|
|
// intermediate segments.
|
|
corrections.push((directive.span, format!("{}::{}", module_name, import)));
|
|
} 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, directive.span, directive.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, directive.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)
|
|
} else {
|
|
// In this case, add a `{`, then the moved import, then whatever
|
|
// was there before.
|
|
format!("{{{}, {}", import, 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; }
|
|
match c {
|
|
':' if num_colons == 2 => false,
|
|
_ => true,
|
|
}
|
|
});
|
|
// 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
|
|
span: Option<Span>,
|
|
candidates: &[ImportSuggestion],
|
|
better: bool,
|
|
found_use: bool,
|
|
) {
|
|
// we want consistent results across executions, but candidates are produced
|
|
// by iterating through a hash map, so make sure they are ordered:
|
|
let mut path_strings: Vec<_> =
|
|
candidates.into_iter().map(|c| path_names_to_string(&c.path)).collect();
|
|
path_strings.sort();
|
|
|
|
let better = if better { "better " } else { "" };
|
|
let msg_diff = match path_strings.len() {
|
|
1 => " is found in another module, you can import it",
|
|
_ => "s are found in other modules, you can import them",
|
|
};
|
|
let msg = format!("possible {}candidate{} into scope", better, msg_diff);
|
|
|
|
if let Some(span) = span {
|
|
for candidate in &mut path_strings {
|
|
// produce an additional newline to separate the new use statement
|
|
// from the directly following item.
|
|
let additional_newline = if found_use {
|
|
""
|
|
} else {
|
|
"\n"
|
|
};
|
|
*candidate = format!("use {};\n{}", candidate, additional_newline);
|
|
}
|
|
|
|
err.span_suggestions(
|
|
span,
|
|
&msg,
|
|
path_strings.into_iter(),
|
|
Applicability::Unspecified,
|
|
);
|
|
} else {
|
|
let mut msg = msg;
|
|
msg.push(':');
|
|
for candidate in path_strings {
|
|
msg.push('\n');
|
|
msg.push_str(&candidate);
|
|
}
|
|
}
|
|
}
|