[inferbo,cost] Fix java arrays

Reviewed By: mbouaziz, ddino

Differential Revision: D15602327

fbshipit-source-id: d17253a15

infer/src/bufferoverrun/bufferOverrunModels.ml

@@ -115,14 +115,27 @@ let malloc ~can_be_zero size_exp =
       match Dom.Mem.find_simple_alias id mem with Some (l, None) -> Loc.get_path l | _ -> None
     in
     let offset, size = (Itv.zero, Dom.Val.get_itv length) in
-    let allocsite =
     let represents_multiple_values = not (Itv.is_one size) in
+    let allocsite =
       Allocsite.make pname ~node_hash ~inst_num:0 ~dimension:1 ~path ~represents_multiple_values
     in
     let size_exp_opt =
       let size_exp = Option.value dyn_length ~default:length0 in
       Relation.SymExp.of_exp ~get_sym_f:(Sem.get_sym_f integer_type_widths mem) size_exp
     in
+    if Language.curr_language_is Java then
+      let internal_arr =
+        let allocsite =
+          Allocsite.make pname ~node_hash ~inst_num:1 ~dimension:1 ~path:None
+            ~represents_multiple_values
+        in
+        Dom.Val.of_java_array_alloc allocsite ~length:size ~traces
+      in
+      let arr_loc = Loc.of_allocsite allocsite in
+      mem
+      |> Dom.Mem.add_heap arr_loc internal_arr
+      |> Dom.Mem.add_stack (Loc.of_id id) (Dom.Val.of_pow_loc ~traces (PowLoc.singleton arr_loc))
+    else
       let v = Dom.Val.of_c_array_alloc allocsite ~stride ~offset ~size ~traces in
       mem
       |> Dom.Mem.add_stack (Loc.of_id id) v

infer/src/bufferoverrun/bufferOverrunUtils.ml

@@ -264,7 +264,12 @@ module Check = struct
 
   let lindex integer_type_widths ~array_exp ~index_exp ~last_included mem location cond_set =
     let idx = Sem.eval integer_type_widths index_exp mem in
-    let arr = Sem.eval_arr integer_type_widths array_exp mem in
+    let arr =
+      if Language.curr_language_is Java then
+        let arr_locs = Sem.eval_locs array_exp mem in
+        if PowLoc.is_empty arr_locs then Dom.Val.Itv.top else Dom.Mem.find_set arr_locs mem
+      else Sem.eval_arr integer_type_widths array_exp mem
+    in
     let idx_sym_exp =
       Relation.SymExp.of_exp ~get_sym_f:(Sem.get_sym_f integer_type_widths mem) index_exp
     in

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

@@ -1,10 +1,10 @@
 codetoanalyze/java/bufferoverrun/Array.java, codetoanalyze.java.bufferoverrun.Array.collection_remove_from_empty_Bad():java.util.ArrayList, 2, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Length trace>,Array declaration,Array access: Offset: 0 Size: 0]
 codetoanalyze/java/bufferoverrun/Array.java, codetoanalyze.java.bufferoverrun.Array.negative_alloc_Bad():void, 1, INFERBO_ALLOC_IS_NEGATIVE, no_bucket, ERROR, [Allocation: Length: -1]
 codetoanalyze/java/bufferoverrun/Array.java, codetoanalyze.java.bufferoverrun.Array.null_pruning1_Bad():void, 2, CONDITION_ALWAYS_TRUE, no_bucket, WARNING, [Here]
-codetoanalyze/java/bufferoverrun/Array.java, codetoanalyze.java.bufferoverrun.Array.null_pruning1_Bad():void, 4, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Length trace>,Array declaration,Assignment,Assignment,Array access: Offset: 10 Size: 5]
+codetoanalyze/java/bufferoverrun/Array.java, codetoanalyze.java.bufferoverrun.Array.null_pruning1_Bad():void, 4, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Length trace>,Array declaration,Array access: Offset: 10 Size: 5]
 codetoanalyze/java/bufferoverrun/Array.java, codetoanalyze.java.bufferoverrun.Array.null_pruning1_Good():void, 2, CONDITION_ALWAYS_FALSE, no_bucket, WARNING, [Here]
-codetoanalyze/java/bufferoverrun/Array.java, codetoanalyze.java.bufferoverrun.Array.null_pruning2_Bad():void, 4, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Length trace>,Array declaration,Assignment,Assignment,Array access: Offset: 10 Size: 5]
+codetoanalyze/java/bufferoverrun/Array.java, codetoanalyze.java.bufferoverrun.Array.null_pruning2_Bad():void, 4, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Length trace>,Array declaration,Array access: Offset: 10 Size: 5]
-codetoanalyze/java/bufferoverrun/Array.java, codetoanalyze.java.bufferoverrun.Array.null_pruning2_Good_FP():void, 4, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Length trace>,Array declaration,Assignment,Assignment,Array access: Offset: 10 Size: 5]
+codetoanalyze/java/bufferoverrun/Array.java, codetoanalyze.java.bufferoverrun.Array.null_pruning2_Good_FP():void, 4, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Length trace>,Array declaration,Array access: Offset: 10 Size: 5]
-codetoanalyze/java/bufferoverrun/ArrayMember.java, codetoanalyze.java.bufferoverrun.ArrayMember.load_array_member_Bad():void, 4, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Offset trace>,Parameter `this.buf[*]`,Assignment,<Length trace>,Array declaration,Assignment,Array access: Offset: [max(10, this.buf[*].lb), min(10, this.buf[*].ub)] Size: 10]
+codetoanalyze/java/bufferoverrun/ArrayMember.java, codetoanalyze.java.bufferoverrun.ArrayMember.load_array_member_Bad():void, 4, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Offset trace>,Parameter `this.buf[*]`,Assignment,<Length trace>,Array declaration,Array access: Offset: [max(10, this.buf[*].lb), min(10, this.buf[*].ub)] Size: 10]
 codetoanalyze/java/bufferoverrun/CompressedData.java, codetoanalyze.java.bufferoverrun.CompressedData.decompressData(codetoanalyze.java.bufferoverrun.CompressedData$D):int, 9, INTEGER_OVERFLOW_L5, no_bucket, ERROR, [<LHS trace>,Parameter `this.yy`,<RHS trace>,Parameter `d.cci[*].s`,Assignment,Binary operation: ([0, this.yy - 1] × d.cci[*].s):signed32]
 codetoanalyze/java/bufferoverrun/External.java, External.external_function_Bad(external.library.SomeExternalClass):void, 1, INTEGER_OVERFLOW_U5, no_bucket, ERROR, [<LHS trace>,Unknown value from: int Integer.intValue(),Assignment,<RHS trace>,Unknown value from: int Integer.intValue(),Assignment,Binary operation: ([-oo, +oo] + [-oo, +oo]):signed32]

infer/tests/codetoanalyze/java/performance/Array.java

@@ -48,4 +48,16 @@ public class Array {
   void copyOf_constant(String[] arr) {
     String[] new_arr = Arrays.copyOf(arr, 10);
   }
+
+  void init_array_linear() {
+    int[] table = new int[256];
+    for (int i = 0; i < table.length; ++i) {
+      table[i] = i;
+    }
+  }
+
+  void fill_big_constant_FP() {
+    String[] arr = new String[300];
+    Arrays.fill(arr, 0);
+  }
 }

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

@@ -1,10 +1,12 @@
 codetoanalyze/java/performance/A.java, B$BArray.error():void, 4, EXPENSIVE_ALLOCATION_CALL, no_bucket, ERROR, [with estimated cost 4, degree = 0]
 codetoanalyze/java/performance/A.java, B.error():void, 4, EXPENSIVE_ALLOCATION_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_overrun_bad():void, 4, BUFFER_OVERRUN_L2, no_bucket, ERROR, [<Offset trace>,Assignment,<Length trace>,Array declaration,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_CALL, no_bucket, ERROR, [with estimated cost 2 + 13 ⋅ length, degree = 1,{length},Loop at line 30]
 codetoanalyze/java/performance/Array.java, codetoanalyze.java.performance.Array.binary_search_log(java.lang.String[]):int, 1, EXPENSIVE_EXECUTION_CALL, no_bucket, ERROR, [with estimated cost 2 + log(arr.length), degree = 0 + 1⋅log,{arr.length},Modeled call to Arrays.binarySearch]
 codetoanalyze/java/performance/Array.java, codetoanalyze.java.performance.Array.copyOf_linear(java.lang.String[]):void, 1, EXPENSIVE_EXECUTION_CALL, no_bucket, ERROR, [with estimated cost 4 + arr.length, degree = 1,{arr.length},Modeled call to Arrays.copyOf]
+codetoanalyze/java/performance/Array.java, codetoanalyze.java.performance.Array.fill_big_constant_FP():void, 0, INFINITE_EXECUTION_TIME_CALL, no_bucket, ERROR, [Unbounded loop,Modeled call to Arrays.fill]
 codetoanalyze/java/performance/Array.java, codetoanalyze.java.performance.Array.fill_linear(java.lang.String[]):void, 1, EXPENSIVE_EXECUTION_CALL, no_bucket, ERROR, [with estimated cost 2 + arr.length, degree = 1,{arr.length},Modeled call to Arrays.fill]
+codetoanalyze/java/performance/Array.java, codetoanalyze.java.performance.Array.init_array_linear():void, 2, EXPENSIVE_EXECUTION_CALL, no_bucket, ERROR, [with estimated cost 2564, degree = 0]
 codetoanalyze/java/performance/ArrayCost.java, ArrayCost.ArrayCost(int[]):void, 5, EXPENSIVE_EXECUTION_CALL, no_bucket, ERROR, [with estimated cost 5 + 5 ⋅ mag.length, degree = 1,{mag.length},Loop at line 15]
 codetoanalyze/java/performance/ArrayCost.java, ArrayCost.isPowOfTwo_FP(int):boolean, 4, EXPENSIVE_EXECUTION_CALL, no_bucket, ERROR, [with estimated cost 883, degree = 0]
 codetoanalyze/java/performance/ArrayListTest.java, ArrayListTest.arraylist_add3_overrun_bad():void, 5, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Length trace>,Array declaration,Through,Through,Through,Array access: Offset added: 4 Size: 3]