Driver: Check for missing/unknown opam packages

Closes ocaml#1302, closes ocaml#1296

Author: jonludlam

src/driver/bin/odoc_driver.ml

@@ -1,6 +1,19 @@
 (* Odoc driver *)
 open Odoc_driver_lib
 
+let check_packages packages =
+  match packages with
+  | [] -> ()
+  | _ -> (
+      match Opam.check packages with
+      | Ok () -> ()
+      | Error missing ->
+          Logs.err (fun m ->
+              m "Error: Unknown/uninstalled packages: %a"
+                Fmt.Dump.(list string)
+                (Util.StringSet.elements missing));
+          exit 1)
+
 let run_inner ~odoc_dir ~odocl_dir ~index_dir ~mld_dir ~compile_grep ~link_grep
     ~generate_grep ~index_grep ~remap ~index_mld packages
     {
@@ -20,6 +33,7 @@ let run_inner ~odoc_dir ~odocl_dir ~index_dir ~mld_dir ~compile_grep ~link_grep
 
   if verbose then Logs.set_level (Some Logs.Debug);
   Logs.set_reporter (Logs_fmt.reporter ());
+  check_packages packages;
   Stats.init_nprocs nb_workers;
 
   let index_mld_content =

src/driver/opam.ml

@@ -281,6 +281,29 @@ let dune_overrides () =
               [])
       | _ -> [])
 
+let check pkgs =
+  let cmd =
+    Cmd.(
+      opam % "list" % "-i" % "--columns" % "package" % "--color" % "never"
+      % "-s")
+  in
+  let cmd = List.fold_left (fun cmd pkg -> Cmd.(cmd % pkg)) cmd pkgs in
+  let out = Util.lines_of_process cmd in
+  let res =
+    List.filter_map
+      (fun x ->
+        match Astring.String.cut ~sep:"." x with
+        | Some (name, _version) -> Some name
+        | None -> None)
+      out
+  in
+  let missing = Util.StringSet.(diff (of_list pkgs) (of_list res)) in
+  let dune_pkgnames =
+    Util.StringSet.of_list (List.map (fun (p, _) -> p.name) (dune_overrides ()))
+  in
+  let missing = Util.StringSet.(diff missing dune_pkgnames) in
+  if Util.StringSet.cardinal missing = 0 then Ok () else Error missing
+
 let pkg_to_dir_map () =
   let dune_overrides = dune_overrides () in
   let pkgs = all_opam_packages () in

src/driver/opam.mli

@@ -20,6 +20,7 @@ val all_opam_packages : unit -> package list
 
 val classify_docs : Fpath.t -> string option -> Fpath.t list -> doc_file list
 
+val check : string list -> (unit, Util.StringSet.t) Result.t
 val deps : string list -> package list
 val pkg_to_dir_map : unit -> fpaths_of_package * package_of_fpath
 val pp : Format.formatter -> package -> unit