diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src/remove_uninit_drops.rs')
| -rw-r--r-- | compiler/rustc_mir_transform/src/remove_uninit_drops.rs | 28 |
1 files changed, 8 insertions, 20 deletions
diff --git a/compiler/rustc_mir_transform/src/remove_uninit_drops.rs b/compiler/rustc_mir_transform/src/remove_uninit_drops.rs index 78b6f714a..1f9e521d3 100644 --- a/compiler/rustc_mir_transform/src/remove_uninit_drops.rs +++ b/compiler/rustc_mir_transform/src/remove_uninit_drops.rs @@ -1,14 +1,15 @@ use rustc_index::bit_set::ChunkedBitSet; -use rustc_middle::mir::{Body, Field, Rvalue, Statement, StatementKind, TerminatorKind}; +use rustc_middle::mir::{Body, TerminatorKind}; use rustc_middle::ty::subst::SubstsRef; use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt, VariantDef}; use rustc_mir_dataflow::impls::MaybeInitializedPlaces; use rustc_mir_dataflow::move_paths::{LookupResult, MoveData, MovePathIndex}; use rustc_mir_dataflow::{self, move_path_children_matching, Analysis, MoveDataParamEnv}; +use rustc_target::abi::FieldIdx; use crate::MirPass; -/// Removes `Drop` and `DropAndReplace` terminators whose target is known to be uninitialized at +/// Removes `Drop` terminators whose target is known to be uninitialized at /// that point. /// /// This is redundant with drop elaboration, but we need to do it prior to const-checking, and @@ -37,8 +38,7 @@ impl<'tcx> MirPass<'tcx> for RemoveUninitDrops { let mut to_remove = vec![]; for (bb, block) in body.basic_blocks.iter_enumerated() { let terminator = block.terminator(); - let (TerminatorKind::Drop { place, .. } | TerminatorKind::DropAndReplace { place, .. }) - = &terminator.kind + let TerminatorKind::Drop { place, .. } = &terminator.kind else { continue }; maybe_inits.seek_before_primary_effect(body.terminator_loc(bb)); @@ -64,24 +64,12 @@ impl<'tcx> MirPass<'tcx> for RemoveUninitDrops { for bb in to_remove { let block = &mut body.basic_blocks_mut()[bb]; - let (TerminatorKind::Drop { target, .. } | TerminatorKind::DropAndReplace { target, .. }) + let TerminatorKind::Drop { target, .. } = &block.terminator().kind else { unreachable!() }; // Replace block terminator with `Goto`. - let target = *target; - let old_terminator_kind = std::mem::replace( - &mut block.terminator_mut().kind, - TerminatorKind::Goto { target }, - ); - - // If this is a `DropAndReplace`, we need to emulate the assignment to the return place. - if let TerminatorKind::DropAndReplace { place, value, .. } = old_terminator_kind { - block.statements.push(Statement { - source_info: block.terminator().source_info, - kind: StatementKind::Assign(Box::new((place, Rvalue::Use(value)))), - }); - } + block.terminator_mut().kind = TerminatorKind::Goto { target: *target }; } } } @@ -143,7 +131,7 @@ fn is_needs_drop_and_init<'tcx>( .fields .iter() .enumerate() - .map(|(f, field)| (Field::from_usize(f), field.ty(tcx, substs), mpi)) + .map(|(f, field)| (FieldIdx::from_usize(f), field.ty(tcx, substs), mpi)) .any(field_needs_drop_and_init) }) } @@ -151,7 +139,7 @@ fn is_needs_drop_and_init<'tcx>( ty::Tuple(fields) => fields .iter() .enumerate() - .map(|(f, f_ty)| (Field::from_usize(f), f_ty, mpi)) + .map(|(f, f_ty)| (FieldIdx::from_usize(f), f_ty, mpi)) .any(field_needs_drop_and_init), _ => true, |