use a mutable field instead of a reference for symbolic memory data

src/symbolic/symbolic_memory.ml

@@ -10,7 +10,7 @@ open Expr
 let page_size = Symbolic_value.const_i32 65_536l
 
 type t =
- { data : (Int32.t, Value.int32) Hashtbl.t option ref
+ { mutable data : (Int32.t, Value.int32) Hashtbl.t option
  ; parent : t option
  ; mutable size : Value.int32
  ; chunks : (Int32.t, Value.int32) Hashtbl.t
@@ -42,11 +42,11 @@ let fill _ = assert false
 let blit _ = assert false
 
 let replace m k v =
- match !(m.data) with
+ match m.data with
  | None ->
  let tbl = Hashtbl.create 16 in
  Hashtbl.add tbl k v;
- m.data := Some tbl
+ m.data <- Some tbl
  | Some tbl -> Hashtbl.replace tbl k v
 
 let blit_string m str ~src ~dst ~len =
@@ -68,18 +68,16 @@ let blit_string m str ~src ~dst ~len =
  end
 
 let clone m =
- let parent = if Option.is_none !(m.data) then m.parent else Some m in
- { data = ref None
+ let parent = if Option.is_none m.data then m.parent else Some m in
+ { data = None
  ; parent
  ; size = m.size
  ; chunks = Hashtbl.copy m.chunks (* TODO: we can make this lazy as well *)
  }
 
 let rec load_byte { parent; data; _ } a =
  try
- match !data with
- | None -> raise Not_found
- | Some data -> Hashtbl.find data a
+ match data with None -> raise Not_found | Some data -> Hashtbl.find data a
  with Not_found -> (
  match parent with
  | None -> make (Val (Num (I8 0)))

src/symbolic/symbolic_memory_concretizing.ml

@@ -4,17 +4,17 @@ module Backend = struct
  type address = Int32.t
 
  type t =
- { data : (address, Symbolic_value.int32) Hashtbl.t option ref
+ { mutable data : (address, Symbolic_value.int32) Hashtbl.t option
  ; parent : t option
  ; chunks : (address, Symbolic_value.int32) Hashtbl.t
  }
 
- let make () = { data = ref None; parent = None; chunks = Hashtbl.create 16 }
+ let make () = { data = None; parent = None; chunks = Hashtbl.create 16 }
 
  let clone m =
- let parent = if Option.is_none !(m.data) then m.parent else Some m in
+ let parent = if Option.is_none m.data then m.parent else Some m in
  (* TODO: Make chunk copying lazy *)
- { data = ref None; parent; chunks = Hashtbl.copy m.chunks }
+ { data = None; parent; chunks = Hashtbl.copy m.chunks }
 
  let address a =
  let open Symbolic_choice_without_memory in
@@ -28,7 +28,7 @@ module Backend = struct
 
  let rec load_byte { parent; data; _ } a =
  try
- match !data with
+ match data with
  | None -> raise Not_found
  | Some data -> Hashtbl.find data a
  with Not_found -> (
@@ -97,11 +97,11 @@ module Backend = struct
  | _ -> Expr.make (Extract (v, pos + 1, pos))
 
  let replace m k v =
- match !(m.data) with
+ match m.data with
  | None ->
  let tbl = Hashtbl.create 16 in
  Hashtbl.add tbl k v;
- m.data := Some tbl
+ m.data <- Some tbl
  | Some tbl -> Hashtbl.replace tbl k v
 
  let storen m a v n =