Module Bit_utils

module Bit_utils: sig .. end

Some bit manipulations.

val sizeofchar : unit -> Integer.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.

Raises Neither_Int_Nor_Enum_Nor_Pointer if the sign of the type is not meaningful.

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 -> Integer.t

Returns the maximal possible offset in bits of a memory base.

val max_bit_size : unit -> Integer.t

Returns the maximal possible size in bits of a memory base.

val max_byte_address : unit -> Integer.t

Since Aluminium-20160501
Returns the maximal possible offset in bytes of a memory base.

val max_byte_size : unit -> Integer.t

Since Aluminium-20160501
Returns the maximal possible size in bytes of a memory base.

Pretty printing

val pretty_bits : Cil_types.typ ->
       use_align:bool ->
       align:Abstract_interp.Rel.t ->
       rh_size:Integer.t ->
       start:Integer.t ->
       stop:Integer.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 =

`\|`	`MatchType of Cil_types.typ`	`(*`	Offset that has this type (modulo attributes)	`*)`
`\|`	`MatchSize of Integer.t`	`(*`	Offset that has a type of this size	`*)`
`\|`	`MatchFirst`	`(*`	Return first symbolic 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:Integer.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.)

Raises NoMatchingOffset when no offset matches.