Upgrade from uint to stdint

The latest uint is just a wrapper around stdint anyway.

Also, switch to smaller Alpine image for Dockerfile build.

Dockerfile

@@ -1,7 +1,6 @@
-FROM ocaml/opam2@sha256:95a87466c507b160bb18e696951b55fe0ace0bdc1fe7f16cbb827ae74ef74198
-#FROM ocaml/opam2:debian-10-ocaml-4.08
-RUN sudo apt-get update
-RUN git fetch && git reset --hard 22aca1413d66271baf995f79feecf7430fc988f1 && opam update
+FROM ocurrent/opam@sha256:4d2dc158efda4a5920440e007638ff08dc2ad8c3af1d0a9ed777924ce6db94fa
+#FROM ocurrent/opam:alpine-3.10-ocaml-4.08
+RUN cd ~/opam-repository && git fetch && git reset --hard 69f81992a5b3ca023f34da67e68c8054d18c7776 && opam update
 RUN opam depext -i capnp afl-persistent conf-capnproto tls mirage-flow-lwt mirage-kv-lwt mirage-clock ptime cmdliner mirage-dns
 ADD --chown=opam *.opam /home/opam/capnp-rpc/
 WORKDIR /home/opam/capnp-rpc/

README.md

@@ -1106,18 +1106,8 @@ Note that calling `wait_forever` prevents further use of the session, however.
 
 ### How can I use this with Mirage?
 
-`capnp` uses the `uint` library, which has C stubs and does not work on most Mirage backends.
-As a quick hack, you can do:
-
-```
-opam pin add uint 'https://github.com/talex5/ocaml-uint.git#dummy'
-```
-
-This allows it to compile and run as a unikernel, by defining `type Uint64.t = Int64.t`, etc.
-However, this changes the behaviour of unsigned integers, so you should be careful with it.
-In particular, OCaml's built-in polymorphic comparison operators (`>`, etc) may give incorrect
-results.
-Ideally, someone would add proper Mirage support to the `uint` library.
+Note: `capnp` uses the `stdint` library, which has C stubs and
+[might need patching](https://github.com/mirage/mirage/issues/885) to work with the Xen backend.
 <https://github.com/ocaml/ocaml/pull/1201#issuecomment-333941042> explains why OCaml doesn't have unsigned integer support.
 
 Here is a suitable `config.ml`:

capnp-rpc-lwt/capnp_rpc_lwt.ml

@@ -41,21 +41,21 @@ module Untyped = struct
     x (StructStorage.cast_reader req) release
 
   let get_cap a i =
-    Core_types.Attachments.cap (Uint32.to_int i) (Msg.unwrap_attachments a)
+    Core_types.Attachments.cap (Stdint.Uint32.to_int i) (Msg.unwrap_attachments a)
 
   let add_cap a cap =
-    Core_types.Attachments.add_cap (Msg.unwrap_attachments a) cap |> Uint32.of_int
+    Core_types.Attachments.add_cap (Msg.unwrap_attachments a) cap |> Stdint.Uint32.of_int
 
   let clear_cap a i =
-    Core_types.Attachments.clear_cap (Msg.unwrap_attachments a) (Uint32.to_int i)
+    Core_types.Attachments.clear_cap (Msg.unwrap_attachments a) (Stdint.Uint32.to_int i)
 
   let unknown_interface ~interface_id _req release_params =
     release_params ();
-    Core_types.fail ~ty:`Unimplemented "Unknown interface %a" Uint64.printer interface_id
+    Core_types.fail ~ty:`Unimplemented "Unknown interface %a" Stdint.Uint64.printer interface_id
 
   let unknown_method ~interface_id ~method_id _req release_params =
     release_params ();
-    Core_types.fail ~ty:`Unimplemented "Unknown method %a.%d" Uint64.printer interface_id method_id
+    Core_types.fail ~ty:`Unimplemented "Unknown method %a.%d" Stdint.Uint64.printer interface_id method_id
 
   class type generic_service = Service.generic
 end

capnp-rpc-lwt/msg.ml

@@ -109,7 +109,7 @@ module Response = struct
     let msg = B.Message.init_root () in
     let ret = B.Message.return_init msg in
     let p = B.Return.results_init ret in
-    B.Payload.content_set_interface p (Some Uint32.zero);   (* Cap index 0 *)
+    B.Payload.content_set_interface p (Some Stdint.Uint32.zero);   (* Cap index 0 *)
     Builder ret
 
   let of_builder x = Builder x

capnp-rpc-lwt/parse.ml

@@ -138,7 +138,7 @@ module Make_basic
   let parse_release x =
     let open Reader in
     let export_id = Release.id_get x |> ExportId.of_uint32 in
-    let ref_count = Release.reference_count_get x |> Uint32.to_int in
+    let ref_count = Release.reference_count_get x |> Stdint.Uint32.to_int in
     `Release (export_id, ref_count)
 
   (* Parse a message received from our peer. Returns [`Not_implemented`] if we couldn't understand it. *)

capnp-rpc-lwt/service.ml

@@ -19,7 +19,7 @@ type ('a, 'b) method_t = 'a -> (unit -> unit) -> Core_types.struct_ref
 let pp_method = Capnp.RPC.Registry.pp_method
 
 class type generic = object
-  method dispatch : interface_id:Uint64.t -> method_id:int -> abstract_method_t
+  method dispatch : interface_id:Stdint.Uint64.t -> method_id:int -> abstract_method_t
   method release : unit
   method pp : Format.formatter -> unit
 end

capnp-rpc-lwt/xform.ml

@@ -6,7 +6,7 @@ let pp f = function
 
 let to_cap_index = function
   | None -> None
-  | Some i -> Some (Uint32.to_int i)
+  | Some i -> Some (Stdint.Uint32.to_int i)
 
 (* [walk ss x xs] is the interface cap index at path [x :: xs] within struct storage [ss]. *)
 let rec walk ss x = function

capnp-rpc.opam

@@ -13,7 +13,7 @@ bug-reports: "https://github.com/mirage/capnp-rpc/issues"
 doc: "https://mirage.github.io/capnp-rpc/"
 depends: [
   "ocaml" {>= "4.03.0"}
-  "uint"
+  "stdint"
   "astring"
   "fmt"
   "logs"

capnp-rpc/debug.ml

@@ -1,7 +1,7 @@
 let src = Logs.Src.create "capnp-rpc" ~doc:"Cap'n Proto RPC"
 module Log = (val Logs.src_log src: Logs.LOG)
 
-let qid_tag = Logs.Tag.def "qid" Uint32.printer
+let qid_tag = Logs.Tag.def "qid" Stdint.Uint32.printer
 
 exception Invariant_broken of (Format.formatter -> unit)
 

capnp-rpc/debug.mli

@@ -6,7 +6,7 @@ module Log : Logs.LOG
 val src : Logs.src
 (** Control the log level for [Log]. *)
 
-val qid_tag : Uint32.t Logs.Tag.def
+val qid_tag : Stdint.Uint32.t Logs.Tag.def
 (** [qid_tag] is used in log reports to tag the question (or answer) ID in the call. *)
 
 exception Invariant_broken of (Format.formatter -> unit)

capnp-rpc/dune

@@ -1,4 +1,4 @@
 (library
  (name capnp_rpc)
  (public_name capnp-rpc)
- (libraries astring fmt logs uint asetmap))
+ (libraries astring fmt logs stdint asetmap))

capnp-rpc/id.ml

@@ -1,5 +1,7 @@
 (** Unique identifiers. *)
 
+open Stdint
+
 module type S = sig
   type t = private Uint32.t
   val zero : t

examples/calc.ml

@@ -24,7 +24,7 @@ module Expr = struct
     | Expression.Literal f -> Float f
     | Expression.PreviousResult None -> failwith "PreviousResult but no cap!"
     | Expression.PreviousResult (Some v) -> Prev v
-    | Expression.Parameter p -> Param (Uint32.to_int p)
+    | Expression.Parameter p -> Param (Stdint.Uint32.to_int p)
     | Expression.Call c ->
       let fn_obj = Expression.Call.function_get c |> or_fail "Missing fn" in
       let params = Expression.Call.params_get_list c |> List.map parse in
@@ -48,7 +48,7 @@ let rec write_expr b expr =
   match expr with
   | Float f -> Expression.literal_set b f
   | Prev v -> Expression.previous_result_set b (Some v)
-  | Param i -> Expression.parameter_set b (Uint32.of_int i)
+  | Param i -> Expression.parameter_set b (Stdint.Uint32.of_int i)
   | Call (f, args) ->
     let c = Expression.call_init b in
     Expression.Call.function_set c (Some f);

test-bin/calc.ml

@@ -8,7 +8,7 @@ module Calc = Examples.Calc
 let pp_qid f = function
   | None -> ()
   | Some x ->
-    let s = Uint32.to_string x in
+    let s = Stdint.Uint32.to_string x in
     Fmt.(styled `Magenta (fun f x -> Fmt.pf f " (qid=%s)" x)) f s
 
 let reporter =

test/test.ml

@@ -1365,7 +1365,7 @@ module Level0 = struct
 
   let send t m = Queue.add m t.to_server
 
-  let qid_of_int x = S.EP.In.QuestionId.of_uint32 (Uint32.of_int x)
+  let qid_of_int x = S.EP.In.QuestionId.of_uint32 (Stdint.Uint32.of_int x)
 
   let init ~bootstrap =
     let from_server = Queue.create () in

test/testbed/test_utils.ml

@@ -14,7 +14,7 @@ let peer_tag = Logs.Tag.def "peer" pp_actor
 let pp_qid f = function
   | None -> ()
   | Some x ->
-    let s = Uint32.to_string x in
+    let s = Stdint.Uint32.to_string x in
     Fmt.(styled `Magenta (fun f x -> Fmt.pf f " (qid=%s)" x)) f s
 
 let reporter =