diff options
Diffstat (limited to '')
| -rw-r--r-- | compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs | 182 |
1 files changed, 120 insertions, 62 deletions
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs index 8bc8964bb..583bc2e28 100644 --- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs +++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs @@ -16,7 +16,7 @@ use rustc_middle::mir::{ FakeReadCause, LocalDecl, LocalInfo, LocalKind, Location, Operand, Place, PlaceRef, ProjectionElem, Rvalue, Statement, StatementKind, Terminator, TerminatorKind, VarBindingForm, }; -use rustc_middle::ty::{self, subst::Subst, suggest_constraining_type_params, PredicateKind, Ty}; +use rustc_middle::ty::{self, suggest_constraining_type_params, PredicateKind, Ty}; use rustc_mir_dataflow::move_paths::{InitKind, MoveOutIndex, MovePathIndex}; use rustc_span::def_id::LocalDefId; use rustc_span::hygiene::DesugaringKind; @@ -198,7 +198,6 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { move_span, move_spans, *moved_place, - Some(used_place), partially_str, loop_message, move_msg, @@ -258,7 +257,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { let ty = place.ty(self.body, self.infcx.tcx).ty; // If we're in pattern, we do nothing in favor of the previous suggestion (#80913). - if is_loop_move & !in_pattern { + // Same for if we're in a loop, see #101119. + if is_loop_move & !in_pattern && !matches!(use_spans, UseSpans::ClosureUse { .. }) { if let ty::Ref(_, _, hir::Mutability::Mut) = ty.kind() { // We have a `&mut` ref, we need to reborrow on each iteration (#62112). err.span_suggestion_verbose( @@ -368,6 +368,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { let mut visitor = ConditionVisitor { spans: &spans, name: &name, errors: vec![] }; visitor.visit_body(&body); + let mut show_assign_sugg = false; let isnt_initialized = if let InitializationRequiringAction::PartialAssignment | InitializationRequiringAction::Assignment = desired_action { @@ -395,6 +396,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { .count() == 0 { + show_assign_sugg = true; "isn't initialized" } else { "is possibly-uninitialized" @@ -445,13 +447,87 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { } } } + err.span_label(decl_span, "binding declared here but left uninitialized"); + if show_assign_sugg { + struct LetVisitor { + decl_span: Span, + sugg_span: Option<Span>, + } + + impl<'v> Visitor<'v> for LetVisitor { + fn visit_stmt(&mut self, ex: &'v hir::Stmt<'v>) { + if self.sugg_span.is_some() { + return; + } + if let hir::StmtKind::Local(hir::Local { + span, ty, init: None, .. + }) = &ex.kind && span.contains(self.decl_span) { + self.sugg_span = ty.map_or(Some(self.decl_span), |ty| Some(ty.span)); + } + hir::intravisit::walk_stmt(self, ex); + } + } + + let mut visitor = LetVisitor { decl_span, sugg_span: None }; + visitor.visit_body(&body); + if let Some(span) = visitor.sugg_span { + self.suggest_assign_value(&mut err, moved_place, span); + } + } err } + fn suggest_assign_value( + &self, + err: &mut Diagnostic, + moved_place: PlaceRef<'tcx>, + sugg_span: Span, + ) { + let ty = moved_place.ty(self.body, self.infcx.tcx).ty; + debug!("ty: {:?}, kind: {:?}", ty, ty.kind()); + + let tcx = self.infcx.tcx; + let implements_default = |ty, param_env| { + let Some(default_trait) = tcx.get_diagnostic_item(sym::Default) else { + return false; + }; + // Regions are already solved, so we must use a fresh InferCtxt, + // but the type has region variables, so erase those. + tcx.infer_ctxt() + .build() + .type_implements_trait( + default_trait, + tcx.erase_regions(ty), + ty::List::empty(), + param_env, + ) + .must_apply_modulo_regions() + }; + + let assign_value = match ty.kind() { + ty::Bool => "false", + ty::Float(_) => "0.0", + ty::Int(_) | ty::Uint(_) => "0", + ty::Never | ty::Error(_) => "", + ty::Adt(def, _) if Some(def.did()) == tcx.get_diagnostic_item(sym::Vec) => "vec![]", + ty::Adt(_, _) if implements_default(ty, self.param_env) => "Default::default()", + _ => "todo!()", + }; + + if !assign_value.is_empty() { + err.span_suggestion_verbose( + sugg_span.shrink_to_hi(), + format!("consider assigning a value"), + format!(" = {}", assign_value), + Applicability::MaybeIncorrect, + ); + } + } + fn suggest_borrow_fn_like( &self, - err: &mut DiagnosticBuilder<'tcx, ErrorGuaranteed>, + err: &mut Diagnostic, ty: Ty<'tcx>, move_sites: &[MoveSite], value_name: &str, @@ -526,12 +602,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { true } - fn suggest_adding_copy_bounds( - &self, - err: &mut DiagnosticBuilder<'tcx, ErrorGuaranteed>, - ty: Ty<'tcx>, - span: Span, - ) { + fn suggest_adding_copy_bounds(&self, err: &mut Diagnostic, ty: Ty<'tcx>, span: Span) { let tcx = self.infcx.tcx; let generics = tcx.generics_of(self.mir_def_id()); @@ -541,41 +612,40 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { .and_then(|def_id| tcx.hir().get_generics(def_id)) else { return; }; // Try to find predicates on *generic params* that would allow copying `ty` - let predicates: Result<Vec<_>, _> = tcx.infer_ctxt().enter(|infcx| { - let mut fulfill_cx = <dyn rustc_infer::traits::TraitEngine<'_>>::new(infcx.tcx); + let infcx = tcx.infer_ctxt().build(); + let mut fulfill_cx = <dyn rustc_infer::traits::TraitEngine<'_>>::new(infcx.tcx); - let copy_did = infcx.tcx.lang_items().copy_trait().unwrap(); - let cause = ObligationCause::new( - span, - self.mir_hir_id(), - rustc_infer::traits::ObligationCauseCode::MiscObligation, - ); - fulfill_cx.register_bound( - &infcx, - self.param_env, - // Erase any region vids from the type, which may not be resolved - infcx.tcx.erase_regions(ty), - copy_did, - cause, - ); - // Select all, including ambiguous predicates - let errors = fulfill_cx.select_all_or_error(&infcx); - - // Only emit suggestion if all required predicates are on generic - errors - .into_iter() - .map(|err| match err.obligation.predicate.kind().skip_binder() { - PredicateKind::Trait(predicate) => match predicate.self_ty().kind() { - ty::Param(param_ty) => Ok(( - generics.type_param(param_ty, tcx), - predicate.trait_ref.print_only_trait_path().to_string(), - )), - _ => Err(()), - }, + let copy_did = infcx.tcx.lang_items().copy_trait().unwrap(); + let cause = ObligationCause::new( + span, + self.mir_hir_id(), + rustc_infer::traits::ObligationCauseCode::MiscObligation, + ); + fulfill_cx.register_bound( + &infcx, + self.param_env, + // Erase any region vids from the type, which may not be resolved + infcx.tcx.erase_regions(ty), + copy_did, + cause, + ); + // Select all, including ambiguous predicates + let errors = fulfill_cx.select_all_or_error(&infcx); + + // Only emit suggestion if all required predicates are on generic + let predicates: Result<Vec<_>, _> = errors + .into_iter() + .map(|err| match err.obligation.predicate.kind().skip_binder() { + PredicateKind::Trait(predicate) => match predicate.self_ty().kind() { + ty::Param(param_ty) => Ok(( + generics.type_param(param_ty, tcx), + predicate.trait_ref.print_only_trait_path().to_string(), + )), _ => Err(()), - }) - .collect() - }); + }, + _ => Err(()), + }) + .collect(); if let Ok(predicates) = predicates { suggest_constraining_type_params( @@ -1124,6 +1194,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { /// short a lifetime. (But sometimes it is more useful to report /// it as a more direct conflict between the execution of a /// `Drop::drop` with an aliasing borrow.) + #[instrument(level = "debug", skip(self))] pub(crate) fn report_borrowed_value_does_not_live_long_enough( &mut self, location: Location, @@ -1131,13 +1202,6 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { place_span: (Place<'tcx>, Span), kind: Option<WriteKind>, ) { - debug!( - "report_borrowed_value_does_not_live_long_enough(\ - {:?}, {:?}, {:?}, {:?}\ - )", - location, borrow, place_span, kind - ); - let drop_span = place_span.1; let root_place = self.prefixes(borrow.borrowed_place.as_ref(), PrefixSet::All).last().unwrap(); @@ -1194,10 +1258,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { let kind_place = kind.filter(|_| place_desc.is_some()).map(|k| (k, place_span.0)); let explanation = self.explain_why_borrow_contains_point(location, &borrow, kind_place); - debug!( - "report_borrowed_value_does_not_live_long_enough(place_desc: {:?}, explanation: {:?})", - place_desc, explanation - ); + debug!(?place_desc, ?explanation); + let err = match (place_desc, explanation) { // If the outlives constraint comes from inside the closure, // for example: @@ -1469,6 +1531,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { err } + #[instrument(level = "debug", skip(self))] fn report_temporary_value_does_not_live_long_enough( &mut self, location: Location, @@ -1478,13 +1541,6 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { proper_span: Span, explanation: BorrowExplanation<'tcx>, ) -> DiagnosticBuilder<'cx, ErrorGuaranteed> { - debug!( - "report_temporary_value_does_not_live_long_enough(\ - {:?}, {:?}, {:?}, {:?}\ - )", - location, borrow, drop_span, proper_span - ); - if let BorrowExplanation::MustBeValidFor { category, span, from_closure: false, .. } = explanation { @@ -2164,7 +2220,9 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { } StorageDeadOrDrop::Destructor(_) => kind, }, - ProjectionElem::Field(..) | ProjectionElem::Downcast(..) => { + ProjectionElem::OpaqueCast { .. } + | ProjectionElem::Field(..) + | ProjectionElem::Downcast(..) => { match place_ty.ty.kind() { ty::Adt(def, _) if def.has_dtor(tcx) => { // Report the outermost adt with a destructor |