diff options
Diffstat (limited to 'compiler/rustc_const_eval/src/transform/promote_consts.rs')
| -rw-r--r-- | compiler/rustc_const_eval/src/transform/promote_consts.rs | 116 |
1 files changed, 55 insertions, 61 deletions
diff --git a/compiler/rustc_const_eval/src/transform/promote_consts.rs b/compiler/rustc_const_eval/src/transform/promote_consts.rs index 6777fae74..fae6117f8 100644 --- a/compiler/rustc_const_eval/src/transform/promote_consts.rs +++ b/compiler/rustc_const_eval/src/transform/promote_consts.rs @@ -133,7 +133,7 @@ impl<'tcx> Visitor<'tcx> for Collector<'_, 'tcx> { } _ => { /* mark as unpromotable below */ } } - } else if let TempState::Defined { ref mut uses, .. } = *temp { + } else if let TempState::Defined { uses, .. } = temp { // We always allow borrows, even mutable ones, as we need // to promote mutable borrows of some ZSTs e.g., `&mut []`. let allowed_use = match context { @@ -216,12 +216,6 @@ impl<'tcx> Validator<'_, 'tcx> { return Err(Unpromotable); } - // We cannot promote things that need dropping, since the promoted value - // would not get dropped. - if self.qualif_local::<qualifs::NeedsDrop>(place.local) { - return Err(Unpromotable); - } - Ok(()) } _ => bug!(), @@ -262,13 +256,17 @@ impl<'tcx> Validator<'_, 'tcx> { } } } else { - let span = self.body.local_decls[local].source_info.span; - span_bug!(span, "{:?} not promotable, qualif_local shouldn't have been called", local); + false } } fn validate_local(&mut self, local: Local) -> Result<(), Unpromotable> { if let TempState::Defined { location: loc, uses, valid } = self.temps[local] { + // We cannot promote things that need dropping, since the promoted value + // would not get dropped. + if self.qualif_local::<qualifs::NeedsDrop>(local) { + return Err(Unpromotable); + } valid.or_else(|_| { let ok = { let block = &self.body[loc.block]; @@ -750,7 +748,7 @@ impl<'a, 'tcx> Promoter<'a, 'tcx> { if loc.statement_index < num_stmts { let (mut rvalue, source_info) = { let statement = &mut self.source[loc.block].statements[loc.statement_index]; - let StatementKind::Assign(box (_, ref mut rhs)) = statement.kind else { + let StatementKind::Assign(box (_, rhs)) = &mut statement.kind else { span_bug!( statement.source_info.span, "{:?} is not an assignment", @@ -780,9 +778,9 @@ impl<'a, 'tcx> Promoter<'a, 'tcx> { self.source[loc.block].terminator().clone() } else { let terminator = self.source[loc.block].terminator_mut(); - let target = match terminator.kind { - TerminatorKind::Call { target: Some(target), .. } => target, - ref kind => { + let target = match &terminator.kind { + TerminatorKind::Call { target: Some(target), .. } => *target, + kind => { span_bug!(terminator.source_info.span, "{:?} not promotable", kind); } }; @@ -816,7 +814,7 @@ impl<'a, 'tcx> Promoter<'a, 'tcx> { ..terminator }; } - ref kind => { + kind => { span_bug!(terminator.source_info.span, "{:?} not promotable", kind); } }; @@ -849,54 +847,50 @@ impl<'a, 'tcx> Promoter<'a, 'tcx> { let local_decls = &mut self.source.local_decls; let loc = candidate.location; let statement = &mut blocks[loc.block].statements[loc.statement_index]; - match statement.kind { - StatementKind::Assign(box ( - _, - Rvalue::Ref(ref mut region, borrow_kind, ref mut place), - )) => { - // Use the underlying local for this (necessarily interior) borrow. - let ty = local_decls[place.local].ty; - let span = statement.source_info.span; - - let ref_ty = tcx.mk_ref( - tcx.lifetimes.re_erased, - ty::TypeAndMut { ty, mutbl: borrow_kind.to_mutbl_lossy() }, - ); + let StatementKind::Assign(box (_, Rvalue::Ref(region, borrow_kind, place))) = &mut statement.kind else { + bug!() + }; - *region = tcx.lifetimes.re_erased; - - let mut projection = vec![PlaceElem::Deref]; - projection.extend(place.projection); - place.projection = tcx.intern_place_elems(&projection); - - // Create a temp to hold the promoted reference. - // This is because `*r` requires `r` to be a local, - // otherwise we would use the `promoted` directly. - let mut promoted_ref = LocalDecl::new(ref_ty, span); - promoted_ref.source_info = statement.source_info; - let promoted_ref = local_decls.push(promoted_ref); - assert_eq!(self.temps.push(TempState::Unpromotable), promoted_ref); - - let promoted_ref_statement = Statement { - source_info: statement.source_info, - kind: StatementKind::Assign(Box::new(( - Place::from(promoted_ref), - Rvalue::Use(promoted_operand(ref_ty, span)), - ))), - }; - self.extra_statements.push((loc, promoted_ref_statement)); - - Rvalue::Ref( - tcx.lifetimes.re_erased, - borrow_kind, - Place { - local: mem::replace(&mut place.local, promoted_ref), - projection: List::empty(), - }, - ) - } - _ => bug!(), - } + // Use the underlying local for this (necessarily interior) borrow. + let ty = local_decls[place.local].ty; + let span = statement.source_info.span; + + let ref_ty = tcx.mk_ref( + tcx.lifetimes.re_erased, + ty::TypeAndMut { ty, mutbl: borrow_kind.to_mutbl_lossy() }, + ); + + *region = tcx.lifetimes.re_erased; + + let mut projection = vec![PlaceElem::Deref]; + projection.extend(place.projection); + place.projection = tcx.intern_place_elems(&projection); + + // Create a temp to hold the promoted reference. + // This is because `*r` requires `r` to be a local, + // otherwise we would use the `promoted` directly. + let mut promoted_ref = LocalDecl::new(ref_ty, span); + promoted_ref.source_info = statement.source_info; + let promoted_ref = local_decls.push(promoted_ref); + assert_eq!(self.temps.push(TempState::Unpromotable), promoted_ref); + + let promoted_ref_statement = Statement { + source_info: statement.source_info, + kind: StatementKind::Assign(Box::new(( + Place::from(promoted_ref), + Rvalue::Use(promoted_operand(ref_ty, span)), + ))), + }; + self.extra_statements.push((loc, promoted_ref_statement)); + + Rvalue::Ref( + tcx.lifetimes.re_erased, + *borrow_kind, + Place { + local: mem::replace(&mut place.local, promoted_ref), + projection: List::empty(), + }, + ) }; assert_eq!(self.new_block(), START_BLOCK); |