added allocation

Reviewed By: mbouaziz

Differential Revision: D14322430

fbshipit-source-id: 5c27a37db

infer/src/checkers/cost.ml

@@ -28,7 +28,10 @@ module ReportConfig = struct
       , { name= "The execution time"
         ; threshold= Option.some_if Config.use_cost_threshold 200
         ; top_and_bottom= true } )
-    ; (CostDomain.AllocationCost, {name= "The allocations"; threshold= None; top_and_bottom= false})
+    ; ( CostDomain.AllocationCost
+      , { name= "The allocations"
+        ; threshold= Option.some_if Config.use_cost_threshold 3
+        ; top_and_bottom= false } )
     ; (CostDomain.IOCost, {name= "The IOs"; threshold= None; top_and_bottom= false}) ]
 
 
@@ -551,12 +554,19 @@ module InstrBasicCost = struct
     For example for basic operation we set it to 1 and for function call we take it from the spec of the function.
   *)
 
+  let allocation_functions = [BuiltinDecl.__new]
+
+  let is_allocation_function callee_pname =
+    List.exists allocation_functions ~f:(fun f -> Typ.Procname.equal callee_pname f)
+
+
   let get_instr_cost_record extras instr_node instr =
     match instr with
-    | Sil.Call (_, Exp.Const (Const.Cfun callee_pname), params, _, _) -> (
+    | Sil.Call (_, Exp.Const (Const.Cfun callee_pname), params, _, _) ->
         let {inferbo_invariant_map; integer_type_widths; get_callee_summary_and_formals} =
           extras
         in
+        let operation_cost =
           match
             BufferOverrunAnalysis.extract_pre (InstrCFG.Node.id instr_node) inferbo_invariant_map
           with
@@ -574,7 +584,11 @@ module InstrBasicCost = struct
                         instantiate_cost integer_type_widths ~inferbo_caller_mem:inferbo_mem
                           ~callee_pname ~callee_formals ~params ~callee_cost ~loc )
                 | None ->
-                  CostDomain.unit_cost_atomic_operation ) ) )
+                    CostDomain.unit_cost_atomic_operation ) )
+        in
+        if is_allocation_function callee_pname then
+          CostDomain.plus CostDomain.unit_cost_allocation operation_cost
+        else operation_cost
     | Sil.Load _ | Sil.Store _ | Sil.Call _ | Sil.Prune _ ->
         CostDomain.unit_cost_atomic_operation
     | Sil.ExitScope _ -> (

infer/src/checkers/costDomain.ml

@@ -91,6 +91,9 @@ let plus cost_record1 cost_record2 =
 (* Map representing cost record {OperationCost:1; AllocationCost:0; IOCost:0} *)
 let unit_cost_atomic_operation = VariantCostMap.increment OperationCost zero_record
 
+(* Map representing cost record {OperationCost:0; AllocationCost:1; IOCost:0} *)
+let unit_cost_allocation = VariantCostMap.increment AllocationCost zero_record
+
 (* Map representing cost record {OperationCost:operation_cost; AllocationCost:0; IOCost:0} *)
 let of_operation_cost operation_cost =
   VariantCostMap.increase_by OperationCost operation_cost zero_record

infer/tests/codetoanalyze/java/performance/A.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2019-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+public class A {}
+
+class B {
+
+  void error() {
+    A a1 = new A();
+    A a2 = new A();
+    A a3 = new A();
+    A a4 = new A();
+  }
+
+  void ok() {
+    A a1 = new A();
+  }
+}

infer/tests/codetoanalyze/java/performance/issues.exp

@@ -1,3 +1,4 @@
+codetoanalyze/java/performance/A.java, B.error():void, 4, EXPENSIVE_EXECUTION_TIME_CALL, no_bucket, ERROR, [with estimated cost 4, degree = 0]
 codetoanalyze/java/performance/Array.java, codetoanalyze.java.performance.Array.array_access_overrun_bad():void, 4, BUFFER_OVERRUN_L2, no_bucket, ERROR, [<Offset trace>,Assignment,<Length trace>,Array declaration,Assignment,Array access: Offset: [2, 8] Size: 8]
 codetoanalyze/java/performance/Array.java, codetoanalyze.java.performance.Array.array_access_weird_ok(long[],int):void, 1, EXPENSIVE_EXECUTION_TIME_CALL, no_bucket, ERROR, [with estimated cost 2 + 15 ⋅ length, degree = 1,{length},Loop at line 28]
 codetoanalyze/java/performance/ArrayCost.java, ArrayCost.ArrayCost(int[]):void, 5, EXPENSIVE_EXECUTION_TIME_CALL, no_bucket, ERROR, [with estimated cost 6 + 5 ⋅ mag.length, degree = 1,{mag.length},Loop at line 15]