[ai] remove option to join sometimes in disjunctive domain

Summary: It was unused and not obviously useful.

Reviewed By: mbouaziz, skcho

Differential Revision: D14258485

fbshipit-source-id: c028e12c1

infer/src/absint/TransferFunctions.ml

@@ -34,7 +34,7 @@ module type MakeHIL = functor (C : ProcCfg.S) -> sig
 end
 
 module type DisjunctiveConfig = sig
-  val join_policy : [`JoinAfter of int | `UnderApproximateAfter of int | `NeverJoin]
+  val join_policy : [`UnderApproximateAfter of int | `NeverJoin]
 
   val widen_policy : [`UnderApproximateAfterNumIterations of int]
 end
@@ -76,20 +76,6 @@ module MakeHILDisjunctive (TransferFunctions : HILDisjReady) (DConfig : Disjunct
             union
         | `UnderApproximateAfter n ->
             if Set.cardinal union <= n then union else lhs
-        | `JoinAfter n ->
-            if Set.cardinal union <= n then union
-            else
-              let joined =
-                Set.fold
-                  (fun dom joined ->
-                    match joined with
-                    | None ->
-                        Some dom
-                    | Some joined ->
-                        Some (TransferFunctions.Domain.join dom joined) )
-                  union None
-              in
-              Set.singleton (Option.value_exn joined)
 
 
     let widen ~prev ~next ~num_iters =

infer/src/absint/TransferFunctions.mli

@@ -39,10 +39,7 @@ end
 
 module type DisjunctiveConfig = sig
   val join_policy :
-    [ `JoinAfter of int
-      (** when the set of disjuncts gets bigger than [n] the underlying domain's join is called to
-       collapse them into one state *)
-    | `UnderApproximateAfter of int
+    [ `UnderApproximateAfter of int
       (** When the set of disjuncts gets bigger than [n] then just stop adding new states to it,
          drop any further states on the floor. This corresponds to an under-approximation/bounded
          approach. *)