[src][verbose] print error on missing cmi_infos and cmt_struct

Author: fantazio

src/deadCode.ml

@@ -483,13 +483,18 @@ let load_file fn state =
         (* TODO: stateful computations should take and return the state when possible *)
         state
   in
+  let add_bad_file err fn =
+    if state.State.config.verbose then
+      Printf.eprintf "%s\n%!" err;
+    bad_files := fn :: !bad_files
+  in
   let process_interface fn =
     last_loc := Lexing.dummy_pos;
       if state.State.config.verbose then
         Printf.eprintf "Scanning interface from %s\n%!" fn;
     init_and_continue state fn (fun state ->
     match state.file_infos.cmi_sign with
-    | None -> bad_files := fn :: !bad_files
+    | None -> add_bad_file "Missing cmi_sign" fn
     | Some cmi_sign ->
         read_interface fn cmi_sign state
     )
@@ -500,7 +505,7 @@ let load_file fn state =
       Printf.eprintf "Scanning implementation from %s\n%!" fn;
     init_and_continue state fn (fun state ->
     match state.file_infos.cmt_struct with
-    | None -> bad_files := fn :: !bad_files
+    | None -> add_bad_file "Missing cmt_struct" fn
     | Some structure ->
         regabs state;
         let prepare (loc1, loc2) =