diff options
| author |  xleroy <xleroy@fca1b0fc-160b-0410-b1d3-a4f43f01ea2e> | 2012-12-18 07:54:35 +0000 |
|---|---|---|
| committer | xleroy <xleroy@fca1b0fc-160b-0410-b1d3-a4f43f01ea2e> | 2012-12-18 07:54:35 +0000 |
| commit | 712f3cbae6bfd3c6f6cc40d44f438aa0affcd371 (patch) | |
| tree | 913762a241b5f97b3ef4df086ba6adaeb2ff45c4 /cparser/Bitfields.ml | |
| parent | c629161139899e43a2fe7c5af59ca926cdab370e (diff) | |
Support for inline assembly (asm statements).
cparser: add primitive support for enum types.
bitfield emulation: for bitfields with enum type, choose signed/unsigned as appropriate
git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2074 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
Diffstat (limited to 'cparser/Bitfields.ml')
| -rw-r--r-- | cparser/Bitfields.ml | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/cparser/Bitfields.ml b/cparser/Bitfields.ml index 257f6c8..937a61f 100644 --- a/cparser/Bitfields.ml +++ b/cparser/Bitfields.ml @@ -46,7 +46,7 @@ type bitfield_info = let bitfield_table = (Hashtbl.create 57: (ident * string, bitfield_info) Hashtbl.t) -(* Packing algorithm -- keep consistent with [Cutil.pack_bitfield]! *) +(* Signedness issues *) let unsigned_ikind_for_carrier nbits = if nbits <= 8 then IUChar else @@ -56,7 +56,26 @@ let unsigned_ikind_for_carrier nbits = if nbits <= 8 * !config.sizeof_longlong then IULongLong else assert false -let pack_bitfields env id ml = +let fits_unsigned v n = + v >= 0L && v < Int64.shift_left 1L n + +let fits_signed v n = + let p = Int64.shift_left 1L (n-1) in v >= Int64.neg p && v < p + +let is_signed_enum_bitfield env sid fld eid n = + let info = Env.find_enum env eid in + if List.for_all (fun (_, v, _) -> int_representable v n false) info.Env.ei_members + then false + else if List.for_all (fun (_, v, _) -> int_representable v n true) info.Env.ei_members + then true + else begin + Cerrors.warning "Warning: not all values of type 'enum %s' can be represented in bit-field '%s' of struct '%s' (%d bits are not enough)" eid.name fld sid.name n; + false + end + +(* Packing algorithm -- keep consistent with [Cutil.pack_bitfield]! *) + +let pack_bitfields env sid ml = let rec pack accu pos = function | [] -> (pos, accu, []) @@ -72,6 +91,7 @@ let pack_bitfields env id ml = let signed = match unroll env m.fld_typ with | TInt(ik, _) -> is_signed_ikind ik + | TEnum(eid, _) -> is_signed_enum_bitfield env sid m.fld_name eid n | _ -> assert false (* should never happen, checked in Elab *) in let signed2 = match unroll env (type_of_member env m) with |