Frama-C:
Plug-ins:
Libraries:

Frama-C API - Bit_utils

Some bit manipulations.

val sizeofchar : unit -> Z.t

sizeof(char) in bits

val sizeofpointer : unit -> int

sizeof(char* ) in bits

val sizeof : Cil_types.typ -> Int_Base.t

sizeof ty is the size of ty in bits. This function may return Int_Base.top.

val osizeof : Cil_types.typ -> Int_Base.t

osizeof ty is the size of ty in bytes. This function may return Int_Base.top.

exception Neither_Int_Nor_Enum_Nor_Pointer
val is_signed_int_enum_pointer : Cil_types.typ -> bool

true means that the type is signed.

val signof_typeof_lval : Cil_types.lval -> bool
  • returns

    the sign of type of the lval. true means that the type is signed.

val sizeof_vid : Cil_types.varinfo -> Int_Base.t
  • returns

    the size of the type of the variable in bits.

val sizeof_lval : Cil_types.lval -> Int_Base.t
  • returns

    the size of the type of the left value in bits.

val sizeof_pointed : Cil_types.typ -> Int_Base.t
  • returns

    the size of the type pointed by a pointer or array type in bits. Never call it on a non pointer or non array type .

val osizeof_pointed : Cil_types.typ -> Int_Base.t
  • returns

    the size of the type pointed by a pointer or array type in bytes. Never call it on a non pointer or array type.

val sizeof_pointed_lval : Cil_types.lval -> Int_Base.t
  • returns

    the size of the type pointed by a pointer type of the lval in bits. Never call it on a non pointer type lval.

val max_bit_address : unit -> Z.t
  • returns

    the maximal possible offset in bits of a memory base.

val max_bit_size : unit -> Z.t
  • returns

    the maximal possible size in bits of a memory base.

val max_byte_address : unit -> Z.t
  • returns

    the maximal possible offset in bytes of a memory base.

  • since Aluminium-20160501
val max_byte_size : unit -> Z.t
  • returns

    the maximal possible size in bytes of a memory base.

  • since Aluminium-20160501

Pretty printing

val pretty_bits : Cil_types.typ -> use_align:bool -> align:Abstract_interp.Rel.t -> rh_size:Z.t -> start:Z.t -> stop:Z.t -> Stdlib.Format.formatter -> bool * Cil_types.typ option

Pretty prints a range of bits in a type for the user. Tries to find field names and array indexes, whenever possible.

Mapping from numeric offsets to symbolic ones.

val type_compatible : Cil_types.typ -> Cil_types.typ -> bool

Comparison of the shape of two types. Attributes are completely ignored.

type offset_match =
  1. | MatchType of Cil_types.typ
    (*

    Offset that has this type (modulo attributes)

    *)
  2. | MatchSize of Z.t
    (*

    Offset that has a type of this size

    *)
  3. | MatchFirst
    (*

    Return first symbolic offset that matches

    *)
  4. | MatchLast
    (*

    Return the longest offset that matches

    *)

We want to find a symbolic offset that corresponds to a numeric one, with one additional criterion:

exception NoMatchingOffset
val find_offset : Cil_types.typ -> offset:Z.t -> offset_match -> Cil_types.offset * Cil_types.typ

find_offset typ ~offset ~size finds a subtype t of typ that describes the type of the bits offset..offset+size-1 in typ. May return a subtype of typ, or a type that is a sub-array of an array type in typ. Also returns a Cil_types.offset off that corresponds to offset. (But we do not have the guarantee that typeof(off) == typ, because of sub-arrays.)