Oversized shift no longer produce an assertion failure

Reviewed By: jeremydubreil

Differential Revision: D5504825

fbshipit-source-id: 1eff425

infer/src/IR/IntLit.ml

@@ -13,6 +13,8 @@ module F = Format
 (** signed and unsigned integer literals *)
 type t = bool * Int64.t * bool
 
+exception OversizedShift
+
 (* the first bool indicates whether this is an unsigned value,
    and the second whether it is a pointer *)
 
@@ -108,7 +110,7 @@ let shift_left (unsigned1, i1, ptr1) (_, i2, _) =
   | None
    -> failwithf "Shifting failed with operand %a" Int64.pp i2
   | Some i2
-   -> if i2 < 0 || i2 >= 64 then failwithf "Oversized shift: %d" i2 ;
+   -> if i2 < 0 || i2 >= 64 then raise OversizedShift ;
       let res = Int64.shift_left i1 i2 in
       (unsigned1, res, ptr1)
 
@@ -117,7 +119,7 @@ let shift_right (unsigned1, i1, ptr1) (_, i2, _) =
   | None
    -> failwithf "Shifting failed with operand %a" Int64.pp i2
   | Some i2
-   -> if i2 < 0 || i2 >= 64 then failwithf "Oversized shift: %d" i2 ;
+   -> if i2 < 0 || i2 >= 64 then raise OversizedShift ;
       let res = Int64.shift_right i1 i2 in
       (unsigned1, res, ptr1)
 

infer/src/IR/IntLit.mli

@@ -14,6 +14,8 @@ module F = Format
 (** signed and unsigned integer literals *)
 type t
 
+exception OversizedShift
+
 val add : t -> t -> t
 
 val compare : t -> t -> int

infer/src/backend/prop.ml

@@ -996,8 +996,9 @@ module Normalize = struct
           if abs then Exp.get_undefined false
           else
             match (e1, e2) with
-            | Const Cint n, Const Cint m
-             -> Exp.int (IntLit.shift_left n m)
+            | Const Cint n, Const Cint m -> (
+              try Exp.int (IntLit.shift_left n m)
+              with IntLit.OversizedShift -> BinOp (Shiftlt, eval e1, eval e2) )
             | _, Const Cint m when IntLit.iszero m
              -> eval e1
             | _, Const Cint m when IntLit.isone m
@@ -1011,8 +1012,9 @@ module Normalize = struct
           if abs then Exp.get_undefined false
           else
             match (e1, e2) with
-            | Const Cint n, Const Cint m
-             -> Exp.int (IntLit.shift_right n m)
+            | Const Cint n, Const Cint m -> (
+              try Exp.int (IntLit.shift_right n m)
+              with IntLit.OversizedShift -> BinOp (Shiftrt, eval e1, eval e2) )
             | _, Const Cint m when IntLit.iszero m
              -> eval e1
             | Const Cint m, _ when IntLit.iszero m