Merge pull request #1431 from reynir/err-no-dev

app_has_no_arguments: also catch when behind `if'

lib/functoria/impl.ml

@@ -42,10 +42,12 @@ and 'a device = ('a, abstract) Device.t
 
 let abstract t = Abstract t
 
-let app_has_no_arguments = function
+let rec app_has_no_arguments = function
   | App { args = Cons _; _ } | Dev { args = Cons _; _ } -> false
   | App _ | Dev _ -> true
-  | If _ -> false
+  | If { cond = _; branches; default } ->
+    app_has_no_arguments default ||
+    List.exists (fun (_, branch) -> app_has_no_arguments branch) branches
 
 (* Devices *)
 

test/mirage/job-no-device-behind-if/config.ml

@@ -0,0 +1,9 @@
+open Mirage
+
+let main = main "App" job
+
+let key =
+  let doc = Key.Arg.info ~doc:"How to say hello." [ "hello" ] in
+  Key.(create "hello" Arg.(opt string "Hello World!" doc))
+
+let () = register ~keys:[ Key.v key ] ~src:`None "noop" [ if_impl Key.is_solo5 main main ]

test/mirage/job-no-device-behind-if/configure.t

@@ -0,0 +1,6 @@
+  $ export MIRAGE_DEFAULT_TARGET=unix
+
+Configure
+  $ ./config.exe configure
+  Fatal error: exception Invalid_argument("Your configuration includes a job without arguments. Please add a dependency in your config.ml: use `let main = Mirage.main \"Unikernel.hello\" (job @-> job) register \"hello\" [ main $ noop ]` instead of `.. job .. [ main ]`.")
+  [2]

test/mirage/job-no-device-behind-if/dune

@@ -0,0 +1,7 @@
+(executable
+ (name config)
+ (libraries mirage))
+
+(cram
+ (package mirage)
+ (deps config.exe))