diff options
Diffstat (limited to 'cparser/Bitfields.ml')
-rw-r--r-- | cparser/Bitfields.ml | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/cparser/Bitfields.ml b/cparser/Bitfields.ml index 2abe6b17..a345d975 100644 --- a/cparser/Bitfields.ml +++ b/cparser/Bitfields.ml @@ -31,7 +31,9 @@ type bitfield_info = bf_carrier_typ: typ; (* type of underlying regular field *) bf_pos: int; (* start bit *) bf_size: int; (* size in bit *) - bf_signed: bool } (* signed or unsigned *) + bf_signed: bool; (* is field signed or unsigned? *) + bf_signed_res: bool (* is result of extracting field signed or unsigned? *) + } (* invariants: 0 <= pos < bitsizeof(int) @@ -71,7 +73,11 @@ let pack_bitfields env id ml = match unroll env m.fld_typ with | TInt(ik, _) -> is_signed_ikind ik | _ -> assert false (* should never happen, checked in Elab *) in - pack ((m.fld_name, pos, n, signed) :: accu) (pos + n) ms + let signed2 = + match unroll env (type_of_member env m) with + | TInt(ik, _) -> is_signed_ikind ik + | _ -> assert false (* should never happen, checked in Elab *) in + pack ((m.fld_name, pos, n, signed, signed2) :: accu) (pos + n) ms end in pack [] 0 ml @@ -85,11 +91,13 @@ let rec transf_members env id count = function let carrier = sprintf "__bf%d" count in let carrier_typ = TInt(unsigned_ikind_for_carrier nbits, []) in List.iter - (fun (name, pos, sz, signed) -> - Hashtbl.add bitfield_table - (id, name) - {bf_carrier = carrier; bf_carrier_typ = carrier_typ; - bf_pos = pos; bf_size = sz; bf_signed = signed}) + (fun (name, pos, sz, signed, signed2) -> + if name <> "" then + Hashtbl.add bitfield_table + (id, name) + {bf_carrier = carrier; bf_carrier_typ = carrier_typ; + bf_pos = pos; bf_size = sz; + bf_signed = signed; bf_signed_res = signed2}) bitfields; { fld_name = carrier; fld_typ = carrier_typ; fld_bitfield = None} :: transf_members env id (count + 1) ml' @@ -144,8 +152,13 @@ let bitfield_extract bf carrier = let ty = TInt((if bf.bf_signed then IInt else IUInt), []) in let e2 = {edesc = ECast(ty, e1); etyp = ty} in - {edesc = EBinop(Oshr, e2, right_shift_count bf, e2.etyp); - etyp = e2.etyp} + let e3 = + {edesc = EBinop(Oshr, e2, right_shift_count bf, e2.etyp); + etyp = ty} in + if bf.bf_signed_res = bf.bf_signed then e3 else begin + let ty' = TInt((if bf.bf_signed_res then IInt else IUInt), []) in + {edesc = ECast(ty', e3); etyp = ty'} + end (* Assign a bitfield within a carrier *) |