diff options
Diffstat (limited to 'compiler/rustc_resolve/src/diagnostics.rs')
| -rw-r--r-- | compiler/rustc_resolve/src/diagnostics.rs | 134 |
1 files changed, 132 insertions, 2 deletions
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs index 201b1c0a493..9149974a617 100644 --- a/compiler/rustc_resolve/src/diagnostics.rs +++ b/compiler/rustc_resolve/src/diagnostics.rs @@ -7,7 +7,7 @@ use rustc_ast::{ use rustc_ast_pretty::pprust; use rustc_attr_data_structures::{self as attr, Stability}; use rustc_data_structures::fx::{FxHashMap, FxHashSet}; -use rustc_data_structures::unord::UnordSet; +use rustc_data_structures::unord::{UnordMap, UnordSet}; use rustc_errors::codes::*; use rustc_errors::{ Applicability, Diag, DiagCtxtHandle, ErrorGuaranteed, MultiSpan, SuggestionStyle, @@ -1054,6 +1054,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { false, false, None, + None, ) else { continue; }; @@ -1482,7 +1483,35 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { parent_scope: &ParentScope<'ra>, ident: Ident, krate: &Crate, + sugg_span: Option<Span>, ) { + // Bring imported but unused `derive` macros into `macro_map` so we ensure they can be used + // for suggestions. + self.visit_scopes( + ScopeSet::Macro(MacroKind::Derive), + &parent_scope, + ident.span.ctxt(), + |this, scope, _use_prelude, _ctxt| { + let Scope::Module(m, _) = scope else { + return None; + }; + for (_, resolution) in this.resolutions(m).borrow().iter() { + let Some(binding) = resolution.borrow().binding else { + continue; + }; + let Res::Def(DefKind::Macro(MacroKind::Derive | MacroKind::Attr), def_id) = + binding.res() + else { + continue; + }; + // By doing this all *imported* macros get added to the `macro_map` even if they + // are *unused*, which makes the later suggestions find them and work. + let _ = this.get_macro_by_def_id(def_id); + } + None::<()> + }, + ); + let is_expected = &|res: Res| res.macro_kind() == Some(macro_kind); let suggestion = self.early_lookup_typo_candidate( ScopeSet::Macro(macro_kind), @@ -1490,7 +1519,9 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { ident, is_expected, ); - self.add_typo_suggestion(err, suggestion, ident.span); + if !self.add_typo_suggestion(err, suggestion, ident.span) { + self.detect_derive_attribute(err, ident, parent_scope, sugg_span); + } let import_suggestions = self.lookup_import_candidates(ident, Namespace::MacroNS, parent_scope, is_expected); @@ -1623,6 +1654,105 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { } } + /// Given an attribute macro that failed to be resolved, look for `derive` macros that could + /// provide it, either as-is or with small typos. + fn detect_derive_attribute( + &self, + err: &mut Diag<'_>, + ident: Ident, + parent_scope: &ParentScope<'ra>, + sugg_span: Option<Span>, + ) { + // Find all of the `derive`s in scope and collect their corresponding declared + // attributes. + // FIXME: this only works if the crate that owns the macro that has the helper_attr + // has already been imported. + let mut derives = vec![]; + let mut all_attrs: UnordMap<Symbol, Vec<_>> = UnordMap::default(); + // We're collecting these in a hashmap, and handle ordering the output further down. + #[allow(rustc::potential_query_instability)] + for (def_id, data) in &self.macro_map { + for helper_attr in &data.ext.helper_attrs { + let item_name = self.tcx.item_name(*def_id); + all_attrs.entry(*helper_attr).or_default().push(item_name); + if helper_attr == &ident.name { + derives.push(item_name); + } + } + } + let kind = MacroKind::Derive.descr(); + if !derives.is_empty() { + // We found an exact match for the missing attribute in a `derive` macro. Suggest it. + let mut derives: Vec<String> = derives.into_iter().map(|d| d.to_string()).collect(); + derives.sort(); + derives.dedup(); + let msg = match &derives[..] { + [derive] => format!(" `{derive}`"), + [start @ .., last] => format!( + "s {} and `{last}`", + start.iter().map(|d| format!("`{d}`")).collect::<Vec<_>>().join(", ") + ), + [] => unreachable!("we checked for this to be non-empty 10 lines above!?"), + }; + let msg = format!( + "`{}` is an attribute that can be used by the {kind}{msg}, you might be \ + missing a `derive` attribute", + ident.name, + ); + let sugg_span = if let ModuleKind::Def(DefKind::Enum, id, _) = parent_scope.module.kind + { + let span = self.def_span(id); + if span.from_expansion() { + None + } else { + // For enum variants sugg_span is empty but we can get the enum's Span. + Some(span.shrink_to_lo()) + } + } else { + // For items this `Span` will be populated, everything else it'll be None. + sugg_span + }; + match sugg_span { + Some(span) => { + err.span_suggestion_verbose( + span, + msg, + format!("#[derive({})]\n", derives.join(", ")), + Applicability::MaybeIncorrect, + ); + } + None => { + err.note(msg); + } + } + } else { + // We didn't find an exact match. Look for close matches. If any, suggest fixing typo. + let all_attr_names = all_attrs.keys().map(|s| *s).into_sorted_stable_ord(); + if let Some(best_match) = find_best_match_for_name(&all_attr_names, ident.name, None) + && let Some(macros) = all_attrs.get(&best_match) + { + let mut macros: Vec<String> = macros.into_iter().map(|d| d.to_string()).collect(); + macros.sort(); + macros.dedup(); + let msg = match ¯os[..] { + [] => return, + [name] => format!(" `{name}` accepts"), + [start @ .., end] => format!( + "s {} and `{end}` accept", + start.iter().map(|m| format!("`{m}`")).collect::<Vec<_>>().join(", "), + ), + }; + let msg = format!("the {kind}{msg} the similarly named `{best_match}` attribute"); + err.span_suggestion_verbose( + ident.span, + msg, + best_match, + Applicability::MaybeIncorrect, + ); + } + } + } + pub(crate) fn add_typo_suggestion( &self, err: &mut Diag<'_>, |