diff options
| -rw-r--r-- | compiler/rustc_mir_transform/src/shim.rs | 64 |
1 files changed, 38 insertions, 26 deletions
diff --git a/compiler/rustc_mir_transform/src/shim.rs b/compiler/rustc_mir_transform/src/shim.rs index c13ffae3649..2c92b4a752c 100644 --- a/compiler/rustc_mir_transform/src/shim.rs +++ b/compiler/rustc_mir_transform/src/shim.rs @@ -214,6 +214,43 @@ fn local_decls_for_sig<'tcx>( .collect() } +fn dropee_emit_retag<'tcx>( + tcx: TyCtxt<'tcx>, + body: &mut Body<'tcx>, + dropee_ptr: Place<'tcx>, + span: Span, +) -> Place<'tcx> { + let mut dropee_ptr = dropee_ptr; + if tcx.sess.opts.unstable_opts.mir_emit_retag { + let source_info = SourceInfo::outermost(span); + // We want to treat the function argument as if it was passed by `&mut`. As such, we + // generate + // ``` + // temp = &mut *arg; + // Retag(temp, FnEntry) + // ``` + // It's important that we do this first, before anything that depends on `dropee_ptr` + // has been put into the body. + let reborrow = Rvalue::Ref( + tcx.lifetimes.re_erased, + BorrowKind::Mut { kind: MutBorrowKind::Default }, + tcx.mk_place_deref(dropee_ptr), + ); + let ref_ty = reborrow.ty(body.local_decls(), tcx); + dropee_ptr = body.local_decls.push(LocalDecl::new(ref_ty, span)).into(); + let new_statements = [ + StatementKind::Assign(Box::new((dropee_ptr, reborrow))), + StatementKind::Retag(RetagKind::FnEntry, Box::new(dropee_ptr)), + ]; + for s in new_statements { + body.basic_blocks_mut()[START_BLOCK] + .statements + .push(Statement { source_info, kind: s }); + } + } + dropee_ptr +} + fn build_drop_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, ty: Option<Ty<'tcx>>) -> Body<'tcx> { debug!("build_drop_shim(def_id={:?}, ty={:?})", def_id, ty); @@ -248,32 +285,7 @@ fn build_drop_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, ty: Option<Ty<'tcx>>) // The first argument (index 0), but add 1 for the return value. let mut dropee_ptr = Place::from(Local::new(1 + 0)); - if tcx.sess.opts.unstable_opts.mir_emit_retag { - // We want to treat the function argument as if it was passed by `&mut`. As such, we - // generate - // ``` - // temp = &mut *arg; - // Retag(temp, FnEntry) - // ``` - // It's important that we do this first, before anything that depends on `dropee_ptr` - // has been put into the body. - let reborrow = Rvalue::Ref( - tcx.lifetimes.re_erased, - BorrowKind::Mut { kind: MutBorrowKind::Default }, - tcx.mk_place_deref(dropee_ptr), - ); - let ref_ty = reborrow.ty(body.local_decls(), tcx); - dropee_ptr = body.local_decls.push(LocalDecl::new(ref_ty, span)).into(); - let new_statements = [ - StatementKind::Assign(Box::new((dropee_ptr, reborrow))), - StatementKind::Retag(RetagKind::FnEntry, Box::new(dropee_ptr)), - ]; - for s in new_statements { - body.basic_blocks_mut()[START_BLOCK] - .statements - .push(Statement { source_info, kind: s }); - } - } + dropee_ptr = dropee_emit_retag(tcx, &mut body, dropee_ptr, span); if ty.is_some() { let patch = { |