tools/ocaml: Fix warnings in config.ml

Fixes warnings such as:

  File "config.ml", line 102, characters 12-27:
  102 |         | Failure "int_of_string"   -> append (k, "expect int arg")
                          ^^^^^^^^^^^^^^^
  Warning 52: Code should not depend on the actual values of
  this constructor's arguments. They are only for information
  and may change in future versions. (See manual section 9.5)

Do not rely on the string values of the `Failure` exception, but use the
`_opt` functions instead.

Signed-off-by: Edwin Török <edwin.torok@cloud.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>
Tested-by: Andrew Cooper <andrew.cooper3@citrix.com>

diff --git a/tools/ocaml/xenstored/config.ml b/tools/ocaml/xenstored/config.ml
index 95ef745a54136ebeedf7f601d8857e99e58b8371..e0df236f738ad45bbb9c197c4f6ba14346ed252d 100644 (file)
--- a/tools/ocaml/xenstored/config.ml
+++ b/tools/ocaml/xenstored/config.ml
@@ -83,25 +83,27 @@ let validate cf expected other =
   let err = ref [] in
   let append x = err := x :: !err in
   List.iter (fun (k, v) ->
+      let parse ~err_msg parser v f =
+        match parser v with
+        | None -> append (k, err_msg)
+        | Some r -> f r
+      in
       try
         if not (List.mem_assoc k expected) then
           other k v
         else let ty = List.assoc k expected in
           match ty with
           | Unit f       -> f ()
-          | Bool f       -> f (bool_of_string v)
+          | Bool f       -> parse ~err_msg:"expect bool arg" bool_of_string_opt v f
           | String f     -> f v
-          | Int f        -> f (int_of_string v)
-          | Float f      -> f (float_of_string v)
-          | Set_bool r   -> r := (bool_of_string v)
+          | Int f        -> parse ~err_msg:"expect int arg" int_of_string_opt v f
+          | Float f      -> parse ~err_msg:"expect float arg" float_of_string_opt v f
+          | Set_bool r   -> parse ~err_msg:"expect bool arg" bool_of_string_opt v (fun x -> r := x)
           | Set_string r -> r := v
-          | Set_int r    -> r := int_of_string v
-          | Set_float r  -> r := (float_of_string v)
+          | Set_int r    -> parse ~err_msg:"expect int arg" int_of_string_opt v (fun x -> r:= x)
+          | Set_float r  -> parse ~err_msg:"expect float arg" float_of_string_opt v (fun x -> r := x)
       with
       | Not_found                 -> append (k, "unknown key")
-      | Failure "int_of_string"   -> append (k, "expect int arg")
-      | Failure "bool_of_string"  -> append (k, "expect bool arg")
-      | Failure "float_of_string" -> append (k, "expect float arg")
       | exn                       -> append (k, Printexc.to_string exn)
     ) cf;
   if !err != [] then raise (Error !err)