Module type Abstract_location.S

module type S = sig .. end

Signature of abstract memory locations.

type value

type location

abstract locations

type offset

abstract offsets

val equal_loc : location -> location -> bool

val equal_offset : offset -> offset -> bool

val pretty_loc : Format.formatter -> location -> unit

val pretty_offset : Format.formatter -> offset -> unit

val to_value : location -> value

val size : location -> Int_Base.t

val partially_overlap : location -> location -> bool

val check_non_overlapping : (Cil_types.lval * location) list ->
       (Cil_types.lval * location) list -> unit Eval.evaluated

Needed for unspecified sequences.

val offset_cardinal_zero_or_one : offset -> bool

Needed for Evaluation.get_influential_vars

Forward Offset Operations

val no_offset : offset

val forward_field : Cil_types.typ ->
       Cil_types.fieldinfo ->
       offset -> offset

Computes the field offset of a fieldinfo, with the given remaining offset. The given type must the one of the structure or the union.

val forward_index : Cil_types.typ ->
       value ->
       offset -> offset

forward_index typ value offset computes the array index offset of (Index (ind, off)), where the index expression ind evaluates to value and the remaining offset off evaluates to offset. typ must be the type pointed by the array.

val reduce_index_by_array_size : size_expr:Cil_types.exp ->
       index_expr:Cil_types.exp ->
       Integer.t ->
       value -> value Eval.evaluated

reduce_index_by_array_size ~size_expr ~index_expr size index reduces the value index to fit into the inverval 0..(size-1). It also returns out-of-bound alarms if it was not already the case. size_expr and index_expr are the Cil expressions of the array size and the index, needed to create the alarms.

Forward Locations Operations

Evaluation of the location of an lvalue, when the offset has already been evaluated. In case of a pointer, its expression has also been evaluated to a value.

val forward_variable : Cil_types.typ ->
       Cil_types.varinfo ->
       offset -> location Eval.or_bottom

Var case in the AST: the host is a variable.

val forward_pointer : Cil_types.typ ->
       value ->
       offset -> location Eval.or_bottom

Mem case in the AST: the host is a pointer.

val eval_varinfo : Cil_types.varinfo -> location

val reduce_loc_by_validity : for_writing:bool ->
       bitfield:bool ->
       Cil_types.lval ->
       location -> location Eval.evaluated

reduce_loc_by_validity for_writing bitfield lval loc reduce the location loc by its valid part for a read or write operation, according to the for_writing boolean. It also returns the alarms enusuring this validity. bitfield indicates whether the location may be the one of a bitfield; if it does not hold, the location is assumed to be byte aligned. lval is only used to create the alarms.

Backward Operations

For an unary forward operation F, the inverse backward opereror B tries to reduce the argument values of the operation, given its result.

It must satisfy: if B arg res = v then ∀ a ⊆ arg such that F a ⊆ res, a ⊆ v

i.e. B arg res returns a value v larger than all subvalues of arg whose result through F is included in res.

If F arg ∈ res is impossible, then v should be bottom.

Any n-ary operator may be considered as a unary operator on a vector of values, the inclusion being lifted pointwise.

val backward_variable : Cil_types.varinfo ->
       location -> offset Eval.or_bottom

val backward_pointer : value ->
       offset ->
       location ->
       (value * offset) Eval.or_bottom

val backward_field : Cil_types.typ ->
       Cil_types.fieldinfo ->
       offset -> offset Eval.or_bottom

val backward_index : Cil_types.typ ->
       index:value ->
       remaining:offset ->
       offset ->
       (value * offset) Eval.or_bottom