[cost] Add some cost models of IntHashMap

Summary: Costs of `IntHashMap.getElement`, `put`, and `remove` are O(1).

Reviewed By: ezgicicek

Differential Revision: D17829788

fbshipit-source-id: f1f6edfbb

infer/src/absint/PatternMatch.ml

@@ -64,10 +64,12 @@ let implements_collections = implements "java.util.Collections"
 
 let implements_list = implements "java.util.List"
 
+let implements_xmob_utils class_name = implements ("com.moblica.common.xmob.utils." ^ class_name)
+
 let implements_pseudo_collection t s =
   implements "android.util.SparseArray" t s
   || implements "android.util.SparseIntArray" t s
-  || implements "com.moblica.common.xmob.utils.IntArrayList" t s
+  || implements_xmob_utils "IntArrayList" t s
 
 
 let implements_enumeration = implements "java.util.Enumeration"

infer/src/absint/PatternMatch.mli

@@ -91,6 +91,9 @@ val implements_google : string -> Tenv.t -> string -> bool
 val implements_android : string -> Tenv.t -> string -> bool
 (** Check whether class implements a class of Android  *)
 
+val implements_xmob_utils : string -> Tenv.t -> string -> bool
+(** Check whether class implements a class of xmod.utils  *)
+
 val supertype_exists : Tenv.t -> (Typ.Name.t -> Typ.Struct.t -> bool) -> Typ.Name.t -> bool
 (** Holds iff the predicate holds on a supertype of the named type, including the type itself *)
 

infer/src/checkers/costModels.ml

@@ -9,6 +9,8 @@ open! IStd
 module BasicCost = CostDomain.BasicCost
 open BufferOverrunUtils.ModelEnv
 
+let unit_cost_model _model_env ~ret:_ _inferbo_mem = BasicCost.one
+
 let linear exp ~of_function {integer_type_widths; location} ~ret:_ inferbo_mem =
   let itv =
     BufferOverrunSemantics.eval integer_type_widths exp inferbo_mem
@@ -164,7 +166,11 @@ module Call = struct
           $+ capt_exp $+ capt_exp $--> JavaString.substring_no_end
         ; +PatternMatch.implements_inject "Provider"
           &:: "get"
-          <>--> modeled ~of_function:"Provider.get" ]
+          <>--> modeled ~of_function:"Provider.get"
+        ; +PatternMatch.implements_xmob_utils "IntHashMap" &:: "<init>" <>--> unit_cost_model
+        ; +PatternMatch.implements_xmob_utils "IntHashMap" &:: "getElement" <>--> unit_cost_model
+        ; +PatternMatch.implements_xmob_utils "IntHashMap" &:: "put" <>--> unit_cost_model
+        ; +PatternMatch.implements_xmob_utils "IntHashMap" &:: "remove" <>--> unit_cost_model ]
     in
     merge_dispatchers dispatcher FbCostModels.Call.dispatch
 end