diff options
Diffstat (limited to 'compiler/rustc_infer/src/infer/error_reporting/note.rs')
| -rw-r--r-- | compiler/rustc_infer/src/infer/error_reporting/note.rs | 195 |
1 files changed, 84 insertions, 111 deletions
diff --git a/compiler/rustc_infer/src/infer/error_reporting/note.rs b/compiler/rustc_infer/src/infer/error_reporting/note.rs index d2dffa4a0..b18cbd404 100644 --- a/compiler/rustc_infer/src/infer/error_reporting/note.rs +++ b/compiler/rustc_infer/src/infer/error_reporting/note.rs @@ -2,11 +2,14 @@ use crate::errors::RegionOriginNote; use crate::infer::error_reporting::{note_and_explain_region, TypeErrCtxt}; use crate::infer::{self, SubregionOrigin}; use rustc_errors::{ - fluent, struct_span_err, AddToDiagnostic, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, + fluent, struct_span_err, AddToDiagnostic, Applicability, Diagnostic, DiagnosticBuilder, + ErrorGuaranteed, }; +use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_middle::traits::ObligationCauseCode; use rustc_middle::ty::error::TypeError; -use rustc_middle::ty::{self, Region}; +use rustc_middle::ty::{self, IsSuggestable, Region}; +use rustc_span::symbol::kw; use super::ObligationCauseAsDiagArg; @@ -22,29 +25,10 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { infer::Reborrow(span) => { RegionOriginNote::Plain { span, msg: fluent::infer_reborrow }.add_to_diagnostic(err) } - infer::ReborrowUpvar(span, ref upvar_id) => { - let var_name = self.tcx.hir().name(upvar_id.var_path.hir_id); - RegionOriginNote::WithName { - span, - msg: fluent::infer_reborrow, - name: &var_name.to_string(), - continues: false, - } - .add_to_diagnostic(err); - } infer::RelateObjectBound(span) => { RegionOriginNote::Plain { span, msg: fluent::infer_relate_object_bound } .add_to_diagnostic(err); } - infer::DataBorrowed(ty, span) => { - RegionOriginNote::WithName { - span, - msg: fluent::infer_data_borrowed, - name: &self.ty_to_string(ty), - continues: false, - } - .add_to_diagnostic(err); - } infer::ReferenceOutlivesReferent(ty, span) => { RegionOriginNote::WithName { span, @@ -159,33 +143,6 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { ); err } - infer::ReborrowUpvar(span, ref upvar_id) => { - let var_name = self.tcx.hir().name(upvar_id.var_path.hir_id); - let mut err = struct_span_err!( - self.tcx.sess, - span, - E0313, - "lifetime of borrowed pointer outlives lifetime of captured variable `{}`...", - var_name - ); - note_and_explain_region( - self.tcx, - &mut err, - "...the borrowed pointer is valid for ", - sub, - "...", - None, - ); - note_and_explain_region( - self.tcx, - &mut err, - &format!("...but `{}` is only valid for ", var_name), - sup, - "", - None, - ); - err - } infer::RelateObjectBound(span) => { let mut err = struct_span_err!( self.tcx.sess, @@ -261,32 +218,6 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { ); err } - infer::DataBorrowed(ty, span) => { - let mut err = struct_span_err!( - self.tcx.sess, - span, - E0490, - "a value of type `{}` is borrowed for too long", - self.ty_to_string(ty) - ); - note_and_explain_region( - self.tcx, - &mut err, - "the type is valid for ", - sub, - "", - None, - ); - note_and_explain_region( - self.tcx, - &mut err, - "but the borrow lasts for ", - sup, - "", - None, - ); - err - } infer::ReferenceOutlivesReferent(ty, span) => { let mut err = struct_span_err!( self.tcx.sess, @@ -313,55 +244,38 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { ); err } - infer::CompareImplItemObligation { span, impl_item_def_id, trait_item_def_id } => self - .report_extra_impl_obligation( + infer::CompareImplItemObligation { span, impl_item_def_id, trait_item_def_id } => { + let mut err = self.report_extra_impl_obligation( span, impl_item_def_id, trait_item_def_id, &format!("`{}: {}`", sup, sub), - ), + ); + // We should only suggest rewriting the `where` clause if the predicate is within that `where` clause + if let Some(generics) = self.tcx.hir().get_generics(impl_item_def_id) + && generics.where_clause_span.contains(span) + { + self.suggest_copy_trait_method_bounds( + trait_item_def_id, + impl_item_def_id, + &mut err, + ); + } + err + } infer::CheckAssociatedTypeBounds { impl_item_def_id, trait_item_def_id, parent } => { let mut err = self.report_concrete_failure(*parent, sub, sup); - let trait_item_span = self.tcx.def_span(trait_item_def_id); let item_name = self.tcx.item_name(impl_item_def_id.to_def_id()); err.span_label( trait_item_span, format!("definition of `{}` from trait", item_name), ); - - let trait_predicates = self.tcx.explicit_predicates_of(trait_item_def_id); - let impl_predicates = self.tcx.explicit_predicates_of(impl_item_def_id); - - let impl_predicates: rustc_data_structures::fx::FxHashSet<_> = - impl_predicates.predicates.into_iter().map(|(pred, _)| pred).collect(); - let clauses: Vec<_> = trait_predicates - .predicates - .into_iter() - .filter(|&(pred, _)| !impl_predicates.contains(pred)) - .map(|(pred, _)| format!("{}", pred)) - .collect(); - - if !clauses.is_empty() { - let generics = self.tcx.hir().get_generics(impl_item_def_id).unwrap(); - let where_clause_span = generics.tail_span_for_predicate_suggestion(); - - let suggestion = format!( - "{} {}", - generics.add_where_or_trailing_comma(), - clauses.join(", "), - ); - err.span_suggestion( - where_clause_span, - &format!( - "try copying {} from the trait", - if clauses.len() > 1 { "these clauses" } else { "this clause" } - ), - suggestion, - rustc_errors::Applicability::MaybeIncorrect, - ); - } - + self.suggest_copy_trait_method_bounds( + trait_item_def_id, + impl_item_def_id, + &mut err, + ); err } infer::AscribeUserTypeProvePredicate(span) => { @@ -388,6 +302,65 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { } } + pub fn suggest_copy_trait_method_bounds( + &self, + trait_item_def_id: DefId, + impl_item_def_id: LocalDefId, + err: &mut Diagnostic, + ) { + // FIXME(compiler-errors): Right now this is only being used for region + // predicate mismatches. Ideally, we'd use it for *all* predicate mismatches, + // but right now it's not really very smart when it comes to implicit `Sized` + // predicates and bounds on the trait itself. + + let Some(impl_def_id) = + self.tcx.associated_item(impl_item_def_id).impl_container(self.tcx) else { return; }; + let Some(trait_ref) = self + .tcx + .impl_trait_ref(impl_def_id) + else { return; }; + let trait_substs = trait_ref + .subst_identity() + // Replace the explicit self type with `Self` for better suggestion rendering + .with_self_ty(self.tcx, self.tcx.mk_ty_param(0, kw::SelfUpper)) + .substs; + let trait_item_substs = + ty::InternalSubsts::identity_for_item(self.tcx, impl_item_def_id.to_def_id()) + .rebase_onto(self.tcx, impl_def_id, trait_substs); + + let Ok(trait_predicates) = self + .tcx + .explicit_predicates_of(trait_item_def_id) + .instantiate_own(self.tcx, trait_item_substs) + .map(|(pred, _)| { + if pred.is_suggestable(self.tcx, false) { + Ok(pred.to_string()) + } else { + Err(()) + } + }) + .collect::<Result<Vec<_>, ()>>() else { return; }; + + let Some(generics) = self.tcx.hir().get_generics(impl_item_def_id) else { return; }; + + if trait_predicates.is_empty() { + err.span_suggestion_verbose( + generics.where_clause_span, + "remove the `where` clause", + String::new(), + Applicability::MachineApplicable, + ); + } else { + let space = if generics.where_clause_span.is_empty() { " " } else { "" }; + err.span_suggestion_verbose( + generics.where_clause_span, + "copy the `where` clause predicates from the trait", + format!("{space}where {}", trait_predicates.join(", ")), + Applicability::MachineApplicable, + ); + } + } + pub(super) fn report_placeholder_failure( &self, placeholder_origin: SubregionOrigin<'tcx>, |