Feedback cleanup

This patch splits pretty printing representation from IO operations.

- `Pp` is kept in charge of the abstract pretty printing representation.
- The `Feedback` module provides interface for doing printing IO.

The patch continues work initiated for 8.5 and has the following effects:

- The following functions in `Pp`: `pp`, `ppnl`, `pperr`, `pperrnl`,
  `pperr_flush`, `pp_flush`, `flush_all`, `msg`, `msgnl`, `msgerr`,
  `msgerrnl`, `message` are removed. `Feedback.msg_*` functions must be
  used instead.

- Feedback provides different backends to handle output, currently,
  `stdout`, `emacs` and CoqIDE backends are provided.

- Clients cannot specify flush policy anymore, thus `pp_flush` et al are
  gone.

- `Feedback.feedback` takes an `edit_or_state_id` instead of the old
  mix.

Lightly tested: Test-suite passes, Proof General and CoqIDE seem to work.

1 files changed, 2 insertions, 2 deletions

diff --git a/tools/coqdep.ml b/tools/coqdep.ml
index 13705edaa..9886b263c 100644
--- a/tools/coqdep.ml
+++ b/tools/coqdep.ml
@@ -502,7 +502,7 @@ let coqdep () =
     let user = coqlib//"user-contrib" in
     if Sys.file_exists user then add_rec_dir_no_import add_coqlib_known user [];
     List.iter (fun s -> add_rec_dir_no_import add_coqlib_known s [])
-      (Envars.xdg_dirs (fun x -> Pp.msg_warning (Pp.str x)));
+      (Envars.xdg_dirs (fun x -> Feedback.msg_warning (Pp.str x)));
     List.iter (fun s -> add_rec_dir_no_import add_coqlib_known s []) Envars.coqpath;
   end;
   List.iter (fun (f,d) -> add_mli_known f d ".mli") !mliAccu;
@@ -527,4 +527,4 @@ let _ =
     coqdep ()
   with Errors.UserError(s,p) ->
     let pp = if s <> "_" then Pp.(str s ++ str ": " ++ p) else p in
-    Pp.msgerrnl pp
+    Feedback.msg_error pp