[ocaml] fix uint32 parsing

Don't use int32 to represent uint32 so we don't get overflows...
When extracting an uint32 from a bytestream, copy it to a C uint32 first,
then convert that to an int64 for usage in OCaml (since it doesn't have unsigned ints)

This addresses #793 at least for unsigned 32bit values.
Only tested on 64bit system so far...

sw/ground_segment/tmtc/fw_server.ml

@@ -44,6 +44,7 @@ let fvalue = fun x ->
   match x with
       Pprz.Float x -> x
     | Pprz.Int32 x -> Int32.to_float x
+    | Pprz.Int64 x -> Int64.to_float x
     | Pprz.Int x -> float_of_int x
     | _ -> failwith (sprintf "Receive.log_and_parse: float expected, got '%s'" (Pprz.string_of_value x))
 
@@ -52,6 +53,7 @@ let ivalue = fun x ->
   match x with
       Pprz.Int x -> x
     | Pprz.Int32 x -> Int32.to_int x
+    | Pprz.Int64 x -> Int64.to_int x
     | _ -> failwith "Receive.log_and_parse: int expected"
 
 let format_string_field = fun s ->

sw/ground_segment/tmtc/rotorcraft_server.ml

@@ -44,6 +44,7 @@ let fvalue = fun x ->
   match x with
       Pprz.Float x -> x
     | Pprz.Int32 x -> Int32.to_float x
+    | Pprz.Int64 x -> Int64.to_float x
     | Pprz.Int x -> float_of_int x
     | _ -> failwith (sprintf "Receive.log_and_parse: float expected, got '%s'" (Pprz.string_of_value x))
 
@@ -52,6 +53,7 @@ let ivalue = fun x ->
   match x with
       Pprz.Int x -> x
     | Pprz.Int32 x -> Int32.to_int x
+    | Pprz.Int64 x -> Int64.to_int x
     | _ -> failwith "Receive.log_and_parse: int expected"
 
 (*

sw/lib/ocaml/convert.c

@@ -29,6 +29,7 @@
 #include <stdio.h>
 #include "caml/mlvalues.h"
 #include "caml/alloc.h"
+#include "inttypes.h"
 
 #ifdef ARCH_ALIGN_DOUBLE
 value
@@ -145,6 +146,18 @@ c_int32_of_indexed_bytes(value s, value index)
   return copy_int32(*x);
 }
 
+value
+c_uint32_of_indexed_bytes(value s, value index)
+{
+  uint32_t *x = (uint32_t*)(String_val(s) + Int_val(index));
+
+  /* since OCaml doesn't have unsigned integers,
+   * we represent it as 64bit signed int to make sure it doesn't overflow
+   */
+  int64_t y = *x;
+  return copy_int64(y);
+}
+
 #ifdef ARCH_ALIGN_INT64
 value
 c_int64_of_indexed_bytes(value s, value index)

sw/lib/ocaml/pprz.ml

@@ -76,9 +76,10 @@ let units_file = Env.paparazzi_src // "conf" // "units.xml"
 
 external float_of_bytes : string -> int -> float = "c_float_of_indexed_bytes"
 external double_of_bytes : string -> int -> float = "c_double_of_indexed_bytes"
-external int32_of_bytes : string -> int -> int32 = "c_int32_of_indexed_bytes"
 external int8_of_bytes : string -> int -> int = "c_int8_of_indexed_bytes"
 external int16_of_bytes : string -> int -> int = "c_int16_of_indexed_bytes"
+external int32_of_bytes : string -> int -> int32 = "c_int32_of_indexed_bytes"
+external uint32_of_bytes : string -> int -> int64 = "c_uint32_of_indexed_bytes"
 external int64_of_bytes : string -> int -> int64 = "c_int64_of_indexed_bytes"
 external sprint_float : string -> int -> float -> unit = "c_sprint_float"
 external sprint_double : string -> int -> float -> unit = "c_sprint_double"
@@ -141,7 +142,8 @@ let int_of_string = fun x ->
 let rec value = fun t v ->
   match t with
       Scalar ("uint8" | "uint16" | "int8" | "int16") -> Int (int_of_string v)
-    | Scalar ("uint32" | "int32") -> Int32 (Int32.of_string v)
+    | Scalar "int32" -> Int32 (Int32.of_string v)
+    | Scalar "uint32" -> Int64 (Int64.of_string v)
     | Scalar ("uint64" | "int64") -> Int64 (Int64.of_string v)
     | Scalar ("float" | "double") -> Float (float_of_string v)
     | Scalar "string" -> String v
@@ -351,7 +353,8 @@ let rec value_of_bin = fun buffer index _type ->
     | Scalar "int16" -> Int (int16_of_bytes buffer index), sizeof _type
     | Scalar "float" -> Float (float_of_bytes buffer index), sizeof _type
     | Scalar "double" -> Float (double_of_bytes buffer index), sizeof _type
-    | Scalar ("int32"  | "uint32") -> Int32 (int32_of_bytes buffer index), sizeof _type
+    | Scalar "int32" -> Int32 (int32_of_bytes buffer index), sizeof _type
+    | Scalar "uint32" -> Int64 (uint32_of_bytes buffer index), sizeof _type
     | Scalar ("int64"  | "uint64") -> Int64 (int64_of_bytes buffer index), sizeof _type
     | ArrayType t ->
       (** First get the number of values *)

sw/lib/ocaml/pprz.mli

@@ -51,6 +51,7 @@ type message = {
 
 
 external int32_of_bytes : string -> int -> int32 = "c_int32_of_indexed_bytes"
+external uint32_of_bytes : string -> int -> int64 = "c_uint32_of_indexed_bytes"
 external int64_of_bytes : string -> int -> int64 = "c_int64_of_indexed_bytes"
 (** [int32_of_bytes buffer offset] *)