diff options
Diffstat (limited to 'compiler/rustc_hir_analysis/src/astconv/errors.rs')
| -rw-r--r-- | compiler/rustc_hir_analysis/src/astconv/errors.rs | 123 |
1 files changed, 84 insertions, 39 deletions
diff --git a/compiler/rustc_hir_analysis/src/astconv/errors.rs b/compiler/rustc_hir_analysis/src/astconv/errors.rs index c49e4d9d5..113c3f08a 100644 --- a/compiler/rustc_hir_analysis/src/astconv/errors.rs +++ b/compiler/rustc_hir_analysis/src/astconv/errors.rs @@ -1,10 +1,14 @@ use crate::astconv::AstConv; -use crate::errors::{ManualImplementation, MissingTypeParams}; +use crate::errors::{ + AssocTypeBindingNotAllowed, ManualImplementation, MissingTypeParams, + ParenthesizedFnTraitExpansion, +}; use rustc_data_structures::fx::FxHashMap; use rustc_errors::{pluralize, struct_span_err, Applicability, Diagnostic, ErrorGuaranteed}; use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_infer::traits::FulfillmentError; +use rustc_middle::ty::TyCtxt; use rustc_middle::ty::{self, Ty}; use rustc_session::parse::feature_err; use rustc_span::edit_distance::find_best_match_for_name; @@ -51,7 +55,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { let trait_def = self.tcx().trait_def(trait_def_id); if !trait_def.paren_sugar { - if trait_segment.args().parenthesized { + if trait_segment.args().parenthesized == hir::GenericArgsParentheses::ParenSugar { // For now, require that parenthetical notation be used only with `Fn()` etc. let mut err = feature_err( &self.tcx().sess.parse_sess, @@ -67,7 +71,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { let sess = self.tcx().sess; - if !trait_segment.args().parenthesized { + if trait_segment.args().parenthesized != hir::GenericArgsParentheses::ParenSugar { // For now, require that parenthetical notation be used only with `Fn()` etc. let mut err = feature_err( &sess.parse_sess, @@ -78,43 +82,10 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { // Do not suggest the other syntax if we are in trait impl: // the desugaring would contain an associated type constraint. if !is_impl { - let args = trait_segment - .args - .as_ref() - .and_then(|args| args.args.get(0)) - .and_then(|arg| match arg { - hir::GenericArg::Type(ty) => match ty.kind { - hir::TyKind::Tup(t) => t - .iter() - .map(|e| sess.source_map().span_to_snippet(e.span)) - .collect::<Result<Vec<_>, _>>() - .map(|a| a.join(", ")), - _ => sess.source_map().span_to_snippet(ty.span), - } - .map(|s| format!("({})", s)) - .ok(), - _ => None, - }) - .unwrap_or_else(|| "()".to_string()); - let ret = trait_segment - .args() - .bindings - .iter() - .find_map(|b| match (b.ident.name == sym::Output, &b.kind) { - (true, hir::TypeBindingKind::Equality { term }) => { - let span = match term { - hir::Term::Ty(ty) => ty.span, - hir::Term::Const(c) => self.tcx().hir().span(c.hir_id), - }; - sess.source_map().span_to_snippet(span).ok() - } - _ => None, - }) - .unwrap_or_else(|| "()".to_string()); err.span_suggestion( span, "use parenthetical notation instead", - format!("{}{} -> {}", trait_segment.ident, args, ret), + fn_trait_to_string(self.tcx(), trait_segment, true), Applicability::MaybeIncorrect, ); } @@ -512,8 +483,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { [segment] if segment.args.is_none() => { trait_bound_spans = vec![segment.ident.span]; associated_types = associated_types - .into_iter() - .map(|(_, items)| (segment.ident.span, items)) + .into_values() + .map(|items| (segment.ident.span, items)) .collect(); } _ => {} @@ -629,3 +600,77 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { err.emit(); } } + +/// Emits an error regarding forbidden type binding associations +pub fn prohibit_assoc_ty_binding( + tcx: TyCtxt<'_>, + span: Span, + segment: Option<(&hir::PathSegment<'_>, Span)>, +) { + tcx.sess.emit_err(AssocTypeBindingNotAllowed { + span, + fn_trait_expansion: if let Some((segment, span)) = segment + && segment.args().parenthesized == hir::GenericArgsParentheses::ParenSugar + { + Some(ParenthesizedFnTraitExpansion { + span, + expanded_type: fn_trait_to_string(tcx, segment, false), + }) + } else { + None + }, + }); +} + +pub(crate) fn fn_trait_to_string( + tcx: TyCtxt<'_>, + trait_segment: &hir::PathSegment<'_>, + parenthesized: bool, +) -> String { + let args = trait_segment + .args + .as_ref() + .and_then(|args| args.args.get(0)) + .and_then(|arg| match arg { + hir::GenericArg::Type(ty) => match ty.kind { + hir::TyKind::Tup(t) => t + .iter() + .map(|e| tcx.sess.source_map().span_to_snippet(e.span)) + .collect::<Result<Vec<_>, _>>() + .map(|a| a.join(", ")), + _ => tcx.sess.source_map().span_to_snippet(ty.span), + } + .map(|s| { + // `s.empty()` checks to see if the type is the unit tuple, if so we don't want a comma + if parenthesized || s.is_empty() { format!("({})", s) } else { format!("({},)", s) } + }) + .ok(), + _ => None, + }) + .unwrap_or_else(|| "()".to_string()); + + let ret = trait_segment + .args() + .bindings + .iter() + .find_map(|b| match (b.ident.name == sym::Output, &b.kind) { + (true, hir::TypeBindingKind::Equality { term }) => { + let span = match term { + hir::Term::Ty(ty) => ty.span, + hir::Term::Const(c) => tcx.hir().span(c.hir_id), + }; + + (span != tcx.hir().span(trait_segment.hir_id)) + .then_some(tcx.sess.source_map().span_to_snippet(span).ok()) + .flatten() + } + _ => None, + }) + .unwrap_or_else(|| "()".to_string()); + + if parenthesized { + format!("{}{} -> {}", trait_segment.ident, args, ret) + } else { + format!("{}<{}, Output={}>", trait_segment.ident, args, ret) + } +} |