Inferbo: size of arrayblk is unsigned

Reviewed By: skcho

Differential Revision: D8370803

fbshipit-source-id: 1276b7e

infer/src/bufferoverrun/bufferOverrunChecker.ml

@@ -64,7 +64,7 @@ module TransferFunctions (CFG : ProcCfg.S) = struct
             let size =
               match length with
               | Some length when may_last_field && (IntLit.iszero length || IntLit.isone length) ->
-                  Some (Itv.make_sym pname new_sym_num)
+                  None (* Will be made symbolic by [decl_sym_arr] *)
               | _ ->
                   Option.map ~f:Itv.of_int_lit length
             in

infer/src/bufferoverrun/bufferOverrunUtils.ml

@@ -60,9 +60,8 @@ module Exec = struct
    fun ~decl_sym_val pname tenv ~node_hash location ~depth loc typ ?offset ?size ~inst_num
        ~new_sym_num ~new_alloc_num mem ->
     let option_value opt_x default_f = match opt_x with Some x -> x | None -> default_f () in
-    let itv_make_sym () = Itv.make_sym pname new_sym_num in
-    let offset = option_value offset itv_make_sym in
-    let size = option_value size itv_make_sym in
+    let offset = option_value offset (fun () -> Itv.make_sym pname new_sym_num) in
+    let size = option_value size (fun () -> Itv.make_sym ~unsigned:true pname new_sym_num) in
     let alloc_num = Itv.Counter.next new_alloc_num in
     let elem = Trace.SymAssign (loc, location) in
     let arr =

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

@@ -2,8 +2,8 @@ codetoanalyze/java/performance/ArrayCost.java, boolean ArrayCost.isPowOfTwo_FP(i
 codetoanalyze/java/performance/ArrayCost.java, boolean ArrayCost.isPowOfTwo_FP(int), 4, EXPENSIVE_EXECUTION_TIME_CALL, no_bucket, ERROR, [with estimated cost 882]
 codetoanalyze/java/performance/ArrayCost.java, boolean ArrayCost.isPowOfTwo_FP(int), 5, EXPENSIVE_EXECUTION_TIME_CALL, no_bucket, ERROR, [with estimated cost 882]
 codetoanalyze/java/performance/ArrayCost.java, boolean ArrayCost.isPowOfTwo_FP(int), 12, EXPENSIVE_EXECUTION_TIME_CALL, no_bucket, ERROR, [with estimated cost 889]
-codetoanalyze/java/performance/ArrayCost.java, void ArrayCost.ArrayCost(int[]), 5, EXPENSIVE_EXECUTION_TIME_CALL, no_bucket, ERROR, [with estimated cost 6 + 5 * s$7^2]
-codetoanalyze/java/performance/ArrayCost.java, void ArrayCost.ArrayCost(int[]), 5, EXPENSIVE_EXECUTION_TIME_CALL, no_bucket, ERROR, [with estimated cost 5 + 5 * s$7^2]
+codetoanalyze/java/performance/ArrayCost.java, void ArrayCost.ArrayCost(int[]), 5, EXPENSIVE_EXECUTION_TIME_CALL, no_bucket, ERROR, [with estimated cost 5 + 5 * u$7^2]
+codetoanalyze/java/performance/ArrayCost.java, void ArrayCost.ArrayCost(int[]), 5, EXPENSIVE_EXECUTION_TIME_CALL, no_bucket, ERROR, [with estimated cost 6 + 5 * u$7^2]
 codetoanalyze/java/performance/Break.java, int Break.break_constant(int), 2, EXPENSIVE_EXECUTION_TIME_CALL, no_bucket, ERROR, [with estimated cost 8 + 7 * s$1]
 codetoanalyze/java/performance/Break.java, int Break.break_loop(int,int), 1, EXPENSIVE_EXECUTION_TIME_CALL, no_bucket, ERROR, [with estimated cost 1 + 7 * s$1]
 codetoanalyze/java/performance/Break.java, int Break.break_loop(int,int), 1, EXPENSIVE_EXECUTION_TIME_CALL, no_bucket, ERROR, [with estimated cost 2 + 7 * s$1]