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Module Lmap

module Lmap: sig .. end

Maps from bases to memory maps. The memory maps are those of the Offsetmap module.

type 'a default_contents =
| Bottom
| Top of 'a
| Constant of 'a
| Other

Contents of a variable when it is not present in the state. See function default_contents in the functor below

module Make_LOffset: 
functor (V : sig
include Offsetmap_lattice_with_isotropy
include Lattice_type.With_Top_Opt
end) -> 
functor (Offsetmap : module type of Offsetmap_sig 
     with type v = V.t
      and type widen_hint = V.numerical_widen_hint) -> 
functor (Default_offsetmap : sig
val name : string

Used to create different datatypes each time the functor is applied

val default_offsetmap : Base.t -> Offsetmap.t Lattice_bounds.or_bottom

Value returned when a map is queried, and the base is not present. `Bottom indicates that the base is never bound in such a map.

val default_contents : V.t Lmap.default_contents

This function is used to optimize functions that add keys in a map, in particular when maintaining canonicity w.r.t. default contents. It describes the contents c of the offsetmap resulting from default_offsetmap b. The possible values are:

  • Bottom means that c is V.bottom everywhere, and furthermore that V.bottom has an empty concretization. We deduce from this fact that unmapped keys do not contribute to a join, and that join c v is never c as soon as v is not itself v.
  • Top means that c is V.top everywhere. Thus unmapped keys have a default value more general than the one in a map where the key is bound.
  • `Constant v means that c is an offsetmap with a single interval containing v everywhere. v must be isotropic (in the sense of V.is_isotropic).
  • `Other means that default_offsetmap returns something arbitrary.

This function is only used on keys that change values. Thus it is safe to have default_offsetmap return something that do not match default_contents on constant keys.

end) -> module type of Lmap_sig 
  with type v = V.t
   and type widen_hint_base = V.numerical_widen_hint
   and type offsetmap = Offsetmap.t