2 use rustc::ty::{self, TyCtxt};
4 /// Returns `true` if this place is allowed to be less aligned
5 /// than its containing struct (because it is within a packed
7 pub fn is_disaligned<'tcx, L>(
10 param_env: ty::ParamEnv<'tcx>,
14 L: HasLocalDecls<'tcx>,
16 debug!("is_disaligned({:?})", place);
17 if !is_within_packed(tcx, local_decls, place) {
18 debug!("is_disaligned({:?}) - not within packed", place);
22 let ty = place.ty(local_decls, tcx).ty;
23 match tcx.layout_raw(param_env.and(ty)) {
24 Ok(layout) if layout.align.abi.bytes() == 1 => {
25 // if the alignment is 1, the type can't be further
27 debug!("is_disaligned({:?}) - align = 1", place);
31 debug!("is_disaligned({:?}) - true", place);
37 fn is_within_packed<'tcx, L>(tcx: TyCtxt<'tcx>, local_decls: &L, place: &Place<'tcx>) -> bool
39 L: HasLocalDecls<'tcx>,
41 let mut cursor = place.projection.as_ref();
42 while let &[ref proj_base @ .., elem] = cursor {
46 // encountered a Deref, which is ABI-aligned
47 ProjectionElem::Deref => break,
48 ProjectionElem::Field(..) => {
49 let ty = Place::ty_from(&place.base, proj_base, local_decls, tcx).ty;
51 ty::Adt(def, _) if def.repr.packed() => return true,