Module Property_status

module Property_status: sig .. end
Status of properties.
Since Nitrogen-20111001
Consult the Plugin Development Guide for additional details.


Local status

A local status (shortly, a status) of a property is a status directly set by an emitter. Thus a property may have several distinct status according to who attempts the verification.

Emitting a status


type emitted_status = 
| True (*
for each execution path ep from the program entry point to s, the formula (/\_ h) ==> P(ep) is true
*)
| False_if_reachable (*
for each execution path ep from the program entry point to s, the formula (/\_ h) ==> P(ep) is false
*)
| False_and_reachable (*
it exists an execution path ep from the program entry point to s such that the formula (/\_ h) ==> P(ep) is false
*)
| Dont_know (*
any other case
*)
Type of status emitted by analyzers. Each Property is attached to a program point s and implicitly depends on an execution path from the program entry point to s. It also depends on an explicit set of hypotheses H indicating when emitting the property (see function Property_status.emit).
module Emitted_status: Datatype.S  with type t = emitted_status
exception Inconsistent_emitted_status of emitted_status * emitted_status
val emit : Emitter.t ->
hyps:Property.t list ->
Property.t -> ?distinct:bool -> emitted_status -> unit
emit e ~hyps p s indicates that the status of p is s, is emitted by e, and is based on the list of hypothesis hyps. If e previously emitted another status s', it must be emitted with the same hypotheses and a consistency check is performed between s and s' and the best (by default the strongest) status is kept. If distinct is true (default is false), then we consider than the given status actually merges several statuses coming from distinct execution paths. The strategy for computing the best status is changed accordingly. One example when ~distinct:true may be required is when emitting a status for a pre-condition of a function f since the status associated to a pre-condition p merges all statuses of p at each callsite of the function f.
Raises Inconsistent_emitted_status when emitting False after emitting True or conversely
Returns the kept status.
val emit_and_get : Emitter.t ->
hyps:Property.t list ->
Property.t ->
?distinct:bool ->
emitted_status -> emitted_status
Like Property_status.emit but also returns the computed status.
val logical_consequence : Emitter.t -> Property.t -> Property.t list -> unit
logical_consequence e ppt list indicates that the emitter e considers that ppt is a logical consequence of the conjunction of properties list. Thus it lets the kernel automatically computes it: e must not call functions emit* itself on this property, but the kernel ensures that the status will be up-to-date when getting it.
val legal_dependency_cycle : Emitter.t -> Property.Set.t -> unit
The given properties may define a legal dependency cycle for the given emitter.
Since Oxygen-20120901
val self : State.t
The state which stores the computed status.

Getting a (local) status


type emitter_with_properties = private {
   emitter : Emitter.Usable_emitter.t;
   mutable properties : Property.t list;
   logical_consequence : bool; (*
Is the emitted status automatically inferred?
*)
}
type inconsistent = private {
   valid : emitter_with_properties list;
   invalid : emitter_with_properties list;
}
type status = private 
| Never_tried (*
Nobody tries to verify the property
*)
| Best of emitted_status * emitter_with_properties list (*
who attempt the verification under which hypotheses
*)
| Inconsistent of inconsistent (*
someone locally says the property is valid and someone else says it is invalid: only the consolidated status may conclude.
*)
Type of the local status of a property.
include Datatype.S
val get : Property.t -> status
Returns the most precise **local** status and all its emitters. Consider using Property_status.Consolidation.get if you want to know the consolidated status of the property.
val iter_on_statuses : (emitter_with_properties ->
emitted_status -> unit) ->
Property.t -> unit
val fold_on_statuses : (emitter_with_properties ->
emitted_status -> 'a -> 'a) ->
Property.t -> 'a -> 'a
Iteration on all the individual statuses emitted for the given property.
Since Aluminium-20160501

Consolidated status


module Consolidation: sig .. end
Consolidation of a property status according to the (consolidated) status of the hypotheses of the property.
module Feedback: sig .. end
Lighter version than Consolidation
module Consolidation_graph: sig .. end
See the consolidated status of a property in a graph, which all its dependencies and their consolidated status.

Access to the registered properties


val iter : (Property.t -> unit) -> unit
val fold : (Property.t -> 'a -> 'a) -> 'a -> 'a

API not for casual users


val register : Property.t -> unit
Register the given property. It must not be already registered.
val register_property_add_hook : (Property.t -> unit) -> unit
add an hook that will be called for any newly registered property
Since Neon-20140301
val remove : Property.t -> unit
Remove the property deeply. Must be called only when removing the corresponding annotation.
val register_property_remove_hook : (Property.t -> unit) -> unit
Add and hook that will be called each time a property is removed.
Since Neon-20140301
val merge : old:Property.t list -> Property.t list -> unit
merge old new registers properties in new which are not in old and removes properties in old which are not in new.
val automatically_proven : Property.t -> bool
Is the status of the given property only automatically handled by the kernel?