| use std::cmp::Reverse; |
| |
| use errors::{Applicability, DiagnosticBuilder, DiagnosticId}; |
| use log::debug; |
| use rustc::hir::def::{self, DefKind, CtorKind, Namespace::*}; |
| use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId}; |
| use rustc::session::{Session, config::nightly_options}; |
| use syntax::ast::{self, Expr, ExprKind, Ident}; |
| use syntax::ext::base::MacroKind; |
| use syntax::symbol::{Symbol, kw}; |
| use syntax_pos::{BytePos, Span}; |
| |
| type Res = def::Res<ast::NodeId>; |
| |
| use crate::macros::ParentScope; |
| use crate::resolve_imports::{ImportDirective, ImportDirectiveSubclass, ImportResolver}; |
| use crate::{import_candidate_to_enum_paths, is_self_type, is_self_value, path_names_to_string}; |
| use crate::{AssocSuggestion, CrateLint, ImportSuggestion, ModuleOrUniformRoot, PathResult, |
| PathSource, Resolver, Segment, Suggestion}; |
| |
| impl<'a> Resolver<'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) = if let Some(res) = res { |
| (format!("expected {}, found {} `{}`", expected, res.descr(), path_str), |
| format!("not a {}", expected), |
| span) |
| } 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_without_parent_scope( |
| mod_path, Some(TypeNS), false, span, CrateLint::No |
| ) { |
| PathResult::Module(ModuleOrUniformRoot::Module(module)) => |
| module.def_kind(), |
| _ => None, |
| }.map_or(String::new(), |kind| format!("{} ", kind.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) |
| }; |
| |
| let code = DiagnosticId::Error(code.into()); |
| let mut err = self.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) { |
| __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); |
| |
| __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 `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.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.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); |
| } |
| } |
| |
| let mut levenshtein_worked = false; |
| |
| // Try Levenshtein algorithm. |
| let suggestion = self.lookup_typo_candidate(path, ns, is_expected, span); |
| if let Some(suggestion) = suggestion { |
| let msg = format!( |
| "{} {} with a similar name exists", |
| suggestion.article, suggestion.kind |
| ); |
| err.span_suggestion( |
| ident_span, |
| &msg, |
| suggestion.candidate.to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| |
| levenshtein_worked = true; |
| } |
| |
| // 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); |
| } |
| (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.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.node { |
| 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 = || { |
| 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 { |
| err.span_label( |
| span, |
| format!("did you mean `{} {{ /* fields */ }}`?", path_str), |
| ); |
| } |
| }; |
| |
| match (res, source) { |
| (Res::Def(DefKind::Macro(..), _), _) => { |
| 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.struct_constructors.get(&def_id).cloned() { |
| let accessible_ctor = self.is_accessible(ctor_vis); |
| if is_expected(ctor_def) && !accessible_ctor { |
| err.span_label( |
| span, |
| format!("constructor is not visible here due to private fields"), |
| ); |
| } |
| } else { |
| bad_struct_syntax_suggestion(); |
| } |
| } |
| (Res::Def(DefKind::Union, _), _) | |
| (Res::Def(DefKind::Variant, _), _) | |
| (Res::Def(DefKind::Ctor(_, CtorKind::Fictive), _), _) if ns == ValueNS => { |
| bad_struct_syntax_suggestion(); |
| } |
| (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 |
| } |
| } |
| |
| impl<'a, 'b:'a> 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.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.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.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.resolver.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.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( |
| &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 = crate_module.resolutions.borrow(); |
| let resolution = resolutions.get(&(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.resolver.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.resolver.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.resolver.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.resolver.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) |
| } |
