| use crate::{CrateLint, Module, ModuleKind, ModuleOrUniformRoot}; |
| use crate::{PathResult, PathSource, Segment}; |
| use crate::path_names_to_string; |
| use crate::diagnostics::{ImportSuggestion, TypoSuggestion}; |
| use crate::late::{LateResolutionVisitor, RibKind}; |
| |
| use errors::{Applicability, DiagnosticBuilder, DiagnosticId}; |
| use log::debug; |
| use rustc::hir::def::{self, DefKind, CtorKind}; |
| use rustc::hir::def::Namespace::{self, *}; |
| use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId}; |
| use rustc::hir::PrimTy; |
| use rustc::session::config::nightly_options; |
| use rustc::util::nodemap::FxHashSet; |
| use syntax::ast::{self, Expr, ExprKind, Ident, NodeId, Path, Ty, TyKind}; |
| use syntax::symbol::kw; |
| use syntax::util::lev_distance::find_best_match_for_name; |
| use syntax_pos::hygiene::MacroKind; |
| use syntax_pos::Span; |
| |
| use rustc_error_codes::*; |
| |
| type Res = def::Res<ast::NodeId>; |
| |
| /// A field or associated item from self type suggested in case of resolution failure. |
| enum AssocSuggestion { |
| Field, |
| MethodWithSelf, |
| AssocItem, |
| } |
| |
| fn is_self_type(path: &[Segment], namespace: Namespace) -> bool { |
| namespace == TypeNS && path.len() == 1 && path[0].ident.name == kw::SelfUpper |
| } |
| |
| fn is_self_value(path: &[Segment], namespace: Namespace) -> bool { |
| namespace == ValueNS && path.len() == 1 && path[0].ident.name == kw::SelfLower |
| } |
| |
| /// Gets the stringified path for an enum from an `ImportSuggestion` for an enum variant. |
| fn import_candidate_to_enum_paths(suggestion: &ImportSuggestion) -> (String, String) { |
| let variant_path = &suggestion.path; |
| let variant_path_string = path_names_to_string(variant_path); |
| |
| let path_len = suggestion.path.segments.len(); |
| let enum_path = ast::Path { |
| span: suggestion.path.span, |
| segments: suggestion.path.segments[0..path_len - 1].to_vec(), |
| }; |
| let enum_path_string = path_names_to_string(&enum_path); |
| |
| (variant_path_string, enum_path_string) |
| } |
| |
| impl<'a> LateResolutionVisitor<'a, '_> { |
| /// Handles error reporting for `smart_resolve_path_fragment` function. |
| /// Creates base error and amends it with one short label and possibly some longer helps/notes. |
| pub(crate) fn smart_resolve_report_errors( |
| &mut self, |
| path: &[Segment], |
| span: Span, |
| source: PathSource<'_>, |
| res: Option<Res>, |
| ) -> (DiagnosticBuilder<'a>, Vec<ImportSuggestion>) { |
| let ident_span = path.last().map_or(span, |ident| ident.ident.span); |
| let ns = source.namespace(); |
| let is_expected = &|res| source.is_expected(res); |
| let is_enum_variant = &|res| { |
| if let Res::Def(DefKind::Variant, _) = res { true } else { false } |
| }; |
| |
| // Make the base error. |
| let expected = source.descr_expected(); |
| let path_str = Segment::names_to_string(path); |
| let item_str = path.last().unwrap().ident; |
| let code = source.error_code(res.is_some()); |
| let (base_msg, fallback_label, base_span, could_be_expr) = if let Some(res) = res { |
| (format!("expected {}, found {} `{}`", expected, res.descr(), path_str), |
| format!("not a {}", expected), |
| span, |
| match res { |
| Res::Def(DefKind::Fn, _) => { |
| // Verify whether this is a fn call or an Fn used as a type. |
| self.r.session.source_map().span_to_snippet(span).map(|snippet| { |
| snippet.ends_with(')') |
| }).unwrap_or(false) |
| } |
| Res::Def(DefKind::Ctor(..), _) | |
| Res::Def(DefKind::Method, _) | |
| Res::Def(DefKind::Const, _) | |
| Res::Def(DefKind::AssocConst, _) | |
| Res::SelfCtor(_) | |
| Res::PrimTy(_) | |
| Res::Local(_) => true, |
| _ => false, |
| }) |
| } else { |
| let item_span = path.last().unwrap().ident.span; |
| let (mod_prefix, mod_str) = if path.len() == 1 { |
| (String::new(), "this scope".to_string()) |
| } else if path.len() == 2 && path[0].ident.name == kw::PathRoot { |
| (String::new(), "the crate root".to_string()) |
| } else { |
| let mod_path = &path[..path.len() - 1]; |
| let mod_prefix = match self.resolve_path( |
| mod_path, Some(TypeNS), false, span, CrateLint::No |
| ) { |
| PathResult::Module(ModuleOrUniformRoot::Module(module)) => module.res(), |
| _ => None, |
| }.map_or(String::new(), |res| format!("{} ", res.descr())); |
| (mod_prefix, format!("`{}`", Segment::names_to_string(mod_path))) |
| }; |
| (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str), |
| format!("not found in {}", mod_str), |
| item_span, |
| false) |
| }; |
| |
| let code = DiagnosticId::Error(code.into()); |
| let mut err = self.r.session.struct_span_err_with_code(base_span, &base_msg, code); |
| |
| // Emit help message for fake-self from other languages (e.g., `this` in Javascript). |
| if ["this", "my"].contains(&&*item_str.as_str()) |
| && self.self_value_is_available(path[0].ident.span, span) { |
| err.span_suggestion( |
| span, |
| "did you mean", |
| "self".to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| |
| // Emit special messages for unresolved `Self` and `self`. |
| if is_self_type(path, ns) { |
| syntax::diagnostic_used!(E0411); |
| err.code(DiagnosticId::Error("E0411".into())); |
| err.span_label( |
| span, |
| format!("`Self` is only available in impls, traits, and type definitions"), |
| ); |
| return (err, Vec::new()); |
| } |
| if is_self_value(path, ns) { |
| debug!("smart_resolve_path_fragment: E0424, source={:?}", source); |
| |
| syntax::diagnostic_used!(E0424); |
| err.code(DiagnosticId::Error("E0424".into())); |
| err.span_label(span, match source { |
| PathSource::Pat => format!( |
| "`self` value is a keyword and may not be bound to variables or shadowed", |
| ), |
| _ => format!( |
| "`self` value is a keyword only available in methods with a `self` parameter", |
| ), |
| }); |
| if let Some(span) = &self.diagnostic_metadata.current_function { |
| err.span_label(*span, "this function doesn't have a `self` parameter"); |
| } |
| return (err, Vec::new()); |
| } |
| |
| // Try to lookup name in more relaxed fashion for better error reporting. |
| let ident = path.last().unwrap().ident; |
| let candidates = self.r.lookup_import_candidates(ident, ns, is_expected) |
| .drain(..) |
| .filter(|ImportSuggestion { did, .. }| { |
| match (did, res.and_then(|res| res.opt_def_id())) { |
| (Some(suggestion_did), Some(actual_did)) => *suggestion_did != actual_did, |
| _ => true, |
| } |
| }) |
| .collect::<Vec<_>>(); |
| let crate_def_id = DefId::local(CRATE_DEF_INDEX); |
| if candidates.is_empty() && is_expected(Res::Def(DefKind::Enum, crate_def_id)) { |
| let enum_candidates = |
| self.r.lookup_import_candidates(ident, ns, is_enum_variant); |
| let mut enum_candidates = enum_candidates.iter() |
| .map(|suggestion| { |
| import_candidate_to_enum_paths(&suggestion) |
| }).collect::<Vec<_>>(); |
| enum_candidates.sort(); |
| |
| if !enum_candidates.is_empty() { |
| // Contextualize for E0412 "cannot find type", but don't belabor the point |
| // (that it's a variant) for E0573 "expected type, found variant". |
| let preamble = if res.is_none() { |
| let others = match enum_candidates.len() { |
| 1 => String::new(), |
| 2 => " and 1 other".to_owned(), |
| n => format!(" and {} others", n) |
| }; |
| format!("there is an enum variant `{}`{}; ", |
| enum_candidates[0].0, others) |
| } else { |
| String::new() |
| }; |
| let msg = format!("{}try using the variant's enum", preamble); |
| |
| err.span_suggestions( |
| span, |
| &msg, |
| enum_candidates.into_iter() |
| .map(|(_variant_path, enum_ty_path)| enum_ty_path) |
| // Variants re-exported in prelude doesn't mean `prelude::v1` is the |
| // type name! |
| // FIXME: is there a more principled way to do this that |
| // would work for other re-exports? |
| .filter(|enum_ty_path| enum_ty_path != "std::prelude::v1") |
| // Also write `Option` rather than `std::prelude::v1::Option`. |
| .map(|enum_ty_path| { |
| // FIXME #56861: DRY-er prelude filtering. |
| enum_ty_path.trim_start_matches("std::prelude::v1::").to_owned() |
| }), |
| Applicability::MachineApplicable, |
| ); |
| } |
| } |
| if path.len() == 1 && self.self_type_is_available(span) { |
| if let Some(candidate) = self.lookup_assoc_candidate(ident, ns, is_expected) { |
| let self_is_available = self.self_value_is_available(path[0].ident.span, span); |
| match candidate { |
| AssocSuggestion::Field => { |
| if self_is_available { |
| err.span_suggestion( |
| span, |
| "you might have meant to use the available field", |
| format!("self.{}", path_str), |
| Applicability::MachineApplicable, |
| ); |
| } else { |
| err.span_label( |
| span, |
| "a field by this name exists in `Self`", |
| ); |
| } |
| } |
| AssocSuggestion::MethodWithSelf if self_is_available => { |
| err.span_suggestion( |
| span, |
| "try", |
| format!("self.{}", path_str), |
| Applicability::MachineApplicable, |
| ); |
| } |
| AssocSuggestion::MethodWithSelf | AssocSuggestion::AssocItem => { |
| err.span_suggestion( |
| span, |
| "try", |
| format!("Self::{}", path_str), |
| Applicability::MachineApplicable, |
| ); |
| } |
| } |
| return (err, candidates); |
| } |
| } |
| |
| // Try Levenshtein algorithm. |
| let typo_sugg = self.lookup_typo_candidate(path, ns, is_expected, span); |
| let levenshtein_worked = self.r.add_typo_suggestion(&mut err, typo_sugg, ident_span); |
| |
| // Try context-dependent help if relaxed lookup didn't work. |
| if let Some(res) = res { |
| if self.smart_resolve_context_dependent_help( |
| &mut err, |
| span, |
| source, |
| res, |
| &path_str, |
| &fallback_label, |
| ) { |
| return (err, candidates); |
| } |
| } |
| |
| // Fallback label. |
| if !levenshtein_worked { |
| err.span_label(base_span, fallback_label); |
| self.type_ascription_suggestion(&mut err, base_span); |
| match self.diagnostic_metadata.current_let_binding { |
| Some((pat_sp, Some(ty_sp), None)) |
| if ty_sp.contains(base_span) && could_be_expr => { |
| err.span_suggestion_short( |
| pat_sp.between(ty_sp), |
| "use `=` if you meant to assign", |
| " = ".to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| _ => {} |
| } |
| } |
| (err, candidates) |
| } |
| |
| fn followed_by_brace(&self, span: Span) -> (bool, Option<(Span, String)>) { |
| // HACK(estebank): find a better way to figure out that this was a |
| // parser issue where a struct literal is being used on an expression |
| // where a brace being opened means a block is being started. Look |
| // ahead for the next text to see if `span` is followed by a `{`. |
| let sm = self.r.session.source_map(); |
| let mut sp = span; |
| loop { |
| sp = sm.next_point(sp); |
| match sm.span_to_snippet(sp) { |
| Ok(ref snippet) => { |
| if snippet.chars().any(|c| { !c.is_whitespace() }) { |
| break; |
| } |
| } |
| _ => break, |
| } |
| } |
| let followed_by_brace = match sm.span_to_snippet(sp) { |
| Ok(ref snippet) if snippet == "{" => true, |
| _ => false, |
| }; |
| // In case this could be a struct literal that needs to be surrounded |
| // by parenthesis, find the appropriate span. |
| let mut i = 0; |
| let mut closing_brace = None; |
| loop { |
| sp = sm.next_point(sp); |
| match sm.span_to_snippet(sp) { |
| Ok(ref snippet) => { |
| if snippet == "}" { |
| let sp = span.to(sp); |
| if let Ok(snippet) = sm.span_to_snippet(sp) { |
| closing_brace = Some((sp, snippet)); |
| } |
| break; |
| } |
| } |
| _ => break, |
| } |
| i += 1; |
| // The bigger the span, the more likely we're incorrect -- |
| // bound it to 100 chars long. |
| if i > 100 { |
| break; |
| } |
| } |
| return (followed_by_brace, closing_brace) |
| } |
| |
| /// Provides context-dependent help for errors reported by the `smart_resolve_path_fragment` |
| /// function. |
| /// Returns `true` if able to provide context-dependent help. |
| fn smart_resolve_context_dependent_help( |
| &mut self, |
| err: &mut DiagnosticBuilder<'a>, |
| span: Span, |
| source: PathSource<'_>, |
| res: Res, |
| path_str: &str, |
| fallback_label: &str, |
| ) -> bool { |
| let ns = source.namespace(); |
| let is_expected = &|res| source.is_expected(res); |
| |
| let path_sep = |err: &mut DiagnosticBuilder<'_>, expr: &Expr| match expr.kind { |
| ExprKind::Field(_, ident) => { |
| err.span_suggestion( |
| expr.span, |
| "use the path separator to refer to an item", |
| format!("{}::{}", path_str, ident), |
| Applicability::MaybeIncorrect, |
| ); |
| true |
| } |
| ExprKind::MethodCall(ref segment, ..) => { |
| let span = expr.span.with_hi(segment.ident.span.hi()); |
| err.span_suggestion( |
| span, |
| "use the path separator to refer to an item", |
| format!("{}::{}", path_str, segment.ident), |
| Applicability::MaybeIncorrect, |
| ); |
| true |
| } |
| _ => false, |
| }; |
| |
| let mut bad_struct_syntax_suggestion = |def_id: DefId| { |
| let (followed_by_brace, closing_brace) = self.followed_by_brace(span); |
| let mut suggested = false; |
| match source { |
| PathSource::Expr(Some(parent)) => { |
| suggested = path_sep(err, &parent); |
| } |
| PathSource::Expr(None) if followed_by_brace == true => { |
| if let Some((sp, snippet)) = closing_brace { |
| err.span_suggestion( |
| sp, |
| "surround the struct literal with parenthesis", |
| format!("({})", snippet), |
| Applicability::MaybeIncorrect, |
| ); |
| } else { |
| err.span_label( |
| span, // Note the parenthesis surrounding the suggestion below |
| format!("did you mean `({} {{ /* fields */ }})`?", path_str), |
| ); |
| } |
| suggested = true; |
| }, |
| _ => {} |
| } |
| if !suggested { |
| if let Some(span) = self.r.definitions.opt_span(def_id) { |
| err.span_label(span, &format!("`{}` defined here", path_str)); |
| } |
| err.span_label( |
| span, |
| format!("did you mean `{} {{ /* fields */ }}`?", path_str), |
| ); |
| } |
| }; |
| |
| match (res, source) { |
| (Res::Def(DefKind::Macro(MacroKind::Bang), _), _) => { |
| err.span_suggestion( |
| span, |
| "use `!` to invoke the macro", |
| format!("{}!", path_str), |
| Applicability::MaybeIncorrect, |
| ); |
| if path_str == "try" && span.rust_2015() { |
| err.note("if you want the `try` keyword, you need to be in the 2018 edition"); |
| } |
| } |
| (Res::Def(DefKind::TyAlias, _), PathSource::Trait(_)) => { |
| err.span_label(span, "type aliases cannot be used as traits"); |
| if nightly_options::is_nightly_build() { |
| err.note("did you mean to use a trait alias?"); |
| } |
| } |
| (Res::Def(DefKind::Mod, _), PathSource::Expr(Some(parent))) => { |
| if !path_sep(err, &parent) { |
| return false; |
| } |
| } |
| (Res::Def(DefKind::Enum, def_id), PathSource::TupleStruct) |
| | (Res::Def(DefKind::Enum, def_id), PathSource::Expr(..)) => { |
| if let Some(variants) = self.collect_enum_variants(def_id) { |
| if !variants.is_empty() { |
| let msg = if variants.len() == 1 { |
| "try using the enum's variant" |
| } else { |
| "try using one of the enum's variants" |
| }; |
| |
| err.span_suggestions( |
| span, |
| msg, |
| variants.iter().map(path_names_to_string), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| } else { |
| err.note("did you mean to use one of the enum's variants?"); |
| } |
| } |
| (Res::Def(DefKind::Struct, def_id), _) if ns == ValueNS => { |
| if let Some((ctor_def, ctor_vis)) |
| = self.r.struct_constructors.get(&def_id).cloned() { |
| let accessible_ctor = |
| self.r.is_accessible_from(ctor_vis, self.parent_scope.module); |
| if is_expected(ctor_def) && !accessible_ctor { |
| err.span_label( |
| span, |
| format!("constructor is not visible here due to private fields"), |
| ); |
| } |
| } else { |
| bad_struct_syntax_suggestion(def_id); |
| } |
| } |
| (Res::Def(DefKind::Union, def_id), _) | |
| (Res::Def(DefKind::Variant, def_id), _) | |
| (Res::Def(DefKind::Ctor(_, CtorKind::Fictive), def_id), _) if ns == ValueNS => { |
| bad_struct_syntax_suggestion(def_id); |
| } |
| (Res::Def(DefKind::Ctor(_, CtorKind::Fn), def_id), _) if ns == ValueNS => { |
| if let Some(span) = self.r.definitions.opt_span(def_id) { |
| err.span_label(span, &format!("`{}` defined here", path_str)); |
| } |
| err.span_label( |
| span, |
| format!("did you mean `{}( /* fields */ )`?", path_str), |
| ); |
| } |
| (Res::SelfTy(..), _) if ns == ValueNS => { |
| err.span_label(span, fallback_label); |
| err.note("can't use `Self` as a constructor, you must use the implemented struct"); |
| } |
| (Res::Def(DefKind::TyAlias, _), _) |
| | (Res::Def(DefKind::AssocTy, _), _) if ns == ValueNS => { |
| err.note("can't use a type alias as a constructor"); |
| } |
| _ => return false, |
| } |
| true |
| } |
| |
| fn lookup_assoc_candidate<FilterFn>(&mut self, |
| ident: Ident, |
| ns: Namespace, |
| filter_fn: FilterFn) |
| -> Option<AssocSuggestion> |
| where FilterFn: Fn(Res) -> bool |
| { |
| fn extract_node_id(t: &Ty) -> Option<NodeId> { |
| match t.kind { |
| TyKind::Path(None, _) => Some(t.id), |
| TyKind::Rptr(_, ref mut_ty) => extract_node_id(&mut_ty.ty), |
| // This doesn't handle the remaining `Ty` variants as they are not |
| // that commonly the self_type, it might be interesting to provide |
| // support for those in future. |
| _ => None, |
| } |
| } |
| |
| // Fields are generally expected in the same contexts as locals. |
| if filter_fn(Res::Local(ast::DUMMY_NODE_ID)) { |
| if let Some(node_id) = self.diagnostic_metadata.current_self_type.as_ref() |
| .and_then(extract_node_id) |
| { |
| // Look for a field with the same name in the current self_type. |
| if let Some(resolution) = self.r.partial_res_map.get(&node_id) { |
| match resolution.base_res() { |
| Res::Def(DefKind::Struct, did) | Res::Def(DefKind::Union, did) |
| if resolution.unresolved_segments() == 0 => { |
| if let Some(field_names) = self.r.field_names.get(&did) { |
| if field_names.iter() |
| .any(|&field_name| ident.name == field_name.node) { |
| return Some(AssocSuggestion::Field); |
| } |
| } |
| } |
| _ => {} |
| } |
| } |
| } |
| } |
| |
| for assoc_type_ident in &self.diagnostic_metadata.current_trait_assoc_types { |
| if *assoc_type_ident == ident { |
| return Some(AssocSuggestion::AssocItem); |
| } |
| } |
| |
| // Look for associated items in the current trait. |
| if let Some((module, _)) = self.current_trait_ref { |
| if let Ok(binding) = self.r.resolve_ident_in_module( |
| ModuleOrUniformRoot::Module(module), |
| ident, |
| ns, |
| &self.parent_scope, |
| false, |
| module.span, |
| ) { |
| let res = binding.res(); |
| if filter_fn(res) { |
| return Some(if self.r.has_self.contains(&res.def_id()) { |
| AssocSuggestion::MethodWithSelf |
| } else { |
| AssocSuggestion::AssocItem |
| }); |
| } |
| } |
| } |
| |
| None |
| } |
| |
| fn lookup_typo_candidate( |
| &mut self, |
| path: &[Segment], |
| ns: Namespace, |
| filter_fn: &impl Fn(Res) -> bool, |
| span: Span, |
| ) -> Option<TypoSuggestion> { |
| let mut names = Vec::new(); |
| if path.len() == 1 { |
| // Search in lexical scope. |
| // Walk backwards up the ribs in scope and collect candidates. |
| for rib in self.ribs[ns].iter().rev() { |
| // Locals and type parameters |
| for (ident, &res) in &rib.bindings { |
| if filter_fn(res) { |
| names.push(TypoSuggestion::from_res(ident.name, res)); |
| } |
| } |
| // Items in scope |
| if let RibKind::ModuleRibKind(module) = rib.kind { |
| // Items from this module |
| self.r.add_module_candidates(module, &mut names, &filter_fn); |
| |
| if let ModuleKind::Block(..) = module.kind { |
| // We can see through blocks |
| } else { |
| // Items from the prelude |
| if !module.no_implicit_prelude { |
| let extern_prelude = self.r.extern_prelude.clone(); |
| names.extend(extern_prelude.iter().flat_map(|(ident, _)| { |
| self.r.crate_loader |
| .maybe_process_path_extern(ident.name, ident.span) |
| .and_then(|crate_id| { |
| let crate_mod = Res::Def( |
| DefKind::Mod, |
| DefId { |
| krate: crate_id, |
| index: CRATE_DEF_INDEX, |
| }, |
| ); |
| |
| if filter_fn(crate_mod) { |
| Some(TypoSuggestion::from_res(ident.name, crate_mod)) |
| } else { |
| None |
| } |
| }) |
| })); |
| |
| if let Some(prelude) = self.r.prelude { |
| self.r.add_module_candidates(prelude, &mut names, &filter_fn); |
| } |
| } |
| break; |
| } |
| } |
| } |
| // Add primitive types to the mix |
| if filter_fn(Res::PrimTy(PrimTy::Bool)) { |
| names.extend( |
| self.r.primitive_type_table.primitive_types.iter().map(|(name, prim_ty)| { |
| TypoSuggestion::from_res(*name, Res::PrimTy(*prim_ty)) |
| }) |
| ) |
| } |
| } else { |
| // Search in module. |
| let mod_path = &path[..path.len() - 1]; |
| if let PathResult::Module(module) = self.resolve_path( |
| mod_path, Some(TypeNS), false, span, CrateLint::No |
| ) { |
| if let ModuleOrUniformRoot::Module(module) = module { |
| self.r.add_module_candidates(module, &mut names, &filter_fn); |
| } |
| } |
| } |
| |
| let name = path[path.len() - 1].ident.name; |
| // Make sure error reporting is deterministic. |
| names.sort_by_cached_key(|suggestion| suggestion.candidate.as_str()); |
| |
| match find_best_match_for_name( |
| names.iter().map(|suggestion| &suggestion.candidate), |
| &name.as_str(), |
| None, |
| ) { |
| Some(found) if found != name => names |
| .into_iter() |
| .find(|suggestion| suggestion.candidate == found), |
| _ => None, |
| } |
| } |
| |
| /// Only used in a specific case of type ascription suggestions |
| fn get_colon_suggestion_span(&self, start: Span) -> Span { |
| let cm = self.r.session.source_map(); |
| start.to(cm.next_point(start)) |
| } |
| |
| fn type_ascription_suggestion( |
| &self, |
| err: &mut DiagnosticBuilder<'_>, |
| base_span: Span, |
| ) { |
| let cm = self.r.session.source_map(); |
| let base_snippet = cm.span_to_snippet(base_span); |
| if let Some(sp) = self.diagnostic_metadata.current_type_ascription.last() { |
| let mut sp = *sp; |
| loop { |
| // Try to find the `:`; bail on first non-':' / non-whitespace. |
| sp = cm.next_point(sp); |
| if let Ok(snippet) = cm.span_to_snippet(sp.to(cm.next_point(sp))) { |
| let line_sp = cm.lookup_char_pos(sp.hi()).line; |
| let line_base_sp = cm.lookup_char_pos(base_span.lo()).line; |
| if snippet == ":" { |
| let mut show_label = true; |
| if line_sp != line_base_sp { |
| err.span_suggestion_short( |
| sp, |
| "did you mean to use `;` here instead?", |
| ";".to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| } else { |
| let colon_sp = self.get_colon_suggestion_span(sp); |
| let after_colon_sp = self.get_colon_suggestion_span( |
| colon_sp.shrink_to_hi(), |
| ); |
| if !cm.span_to_snippet(after_colon_sp).map(|s| s == " ") |
| .unwrap_or(false) |
| { |
| err.span_suggestion( |
| colon_sp, |
| "maybe you meant to write a path separator here", |
| "::".to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| show_label = false; |
| } |
| if let Ok(base_snippet) = base_snippet { |
| let mut sp = after_colon_sp; |
| for _ in 0..100 { |
| // Try to find an assignment |
| sp = cm.next_point(sp); |
| let snippet = cm.span_to_snippet(sp.to(cm.next_point(sp))); |
| match snippet { |
| Ok(ref x) if x.as_str() == "=" => { |
| err.span_suggestion( |
| base_span, |
| "maybe you meant to write an assignment here", |
| format!("let {}", base_snippet), |
| Applicability::MaybeIncorrect, |
| ); |
| show_label = false; |
| break; |
| } |
| Ok(ref x) if x.as_str() == "\n" => break, |
| Err(_) => break, |
| Ok(_) => {} |
| } |
| } |
| } |
| } |
| if show_label { |
| err.span_label(base_span, |
| "expecting a type here because of type ascription"); |
| } |
| break; |
| } else if !snippet.trim().is_empty() { |
| debug!("tried to find type ascription `:` token, couldn't find it"); |
| break; |
| } |
| } else { |
| break; |
| } |
| } |
| } |
| } |
| |
| fn find_module(&mut self, def_id: DefId) -> Option<(Module<'a>, ImportSuggestion)> { |
| let mut result = None; |
| let mut seen_modules = FxHashSet::default(); |
| let mut worklist = vec![(self.r.graph_root, Vec::new())]; |
| |
| while let Some((in_module, path_segments)) = worklist.pop() { |
| // abort if the module is already found |
| if result.is_some() { break; } |
| |
| in_module.for_each_child(self.r, |_, ident, _, name_binding| { |
| // abort if the module is already found or if name_binding is private external |
| if result.is_some() || !name_binding.vis.is_visible_locally() { |
| return |
| } |
| if let Some(module) = name_binding.module() { |
| // form the path |
| let mut path_segments = path_segments.clone(); |
| path_segments.push(ast::PathSegment::from_ident(ident)); |
| let module_def_id = module.def_id().unwrap(); |
| if module_def_id == def_id { |
| let path = Path { |
| span: name_binding.span, |
| segments: path_segments, |
| }; |
| result = Some((module, ImportSuggestion { did: Some(def_id), path })); |
| } else { |
| // add the module to the lookup |
| if seen_modules.insert(module_def_id) { |
| worklist.push((module, path_segments)); |
| } |
| } |
| } |
| }); |
| } |
| |
| result |
| } |
| |
| fn collect_enum_variants(&mut self, def_id: DefId) -> Option<Vec<Path>> { |
| self.find_module(def_id).map(|(enum_module, enum_import_suggestion)| { |
| let mut variants = Vec::new(); |
| enum_module.for_each_child(self.r, |_, ident, _, name_binding| { |
| if let Res::Def(DefKind::Variant, _) = name_binding.res() { |
| let mut segms = enum_import_suggestion.path.segments.clone(); |
| segms.push(ast::PathSegment::from_ident(ident)); |
| variants.push(Path { |
| span: name_binding.span, |
| segments: segms, |
| }); |
| } |
| }); |
| variants |
| }) |
| } |
| } |