[cabs] remove dependency of Cabs_debug on Pretty_utils

To be able to load Cabs_debug in ocamldebug, we need to avoid depending on
external c functions.

Makefile.generating

@@ -133,6 +133,7 @@ ifeq ($(HAS_OCAML408),yes)
         Format.String_tag str -> str \
       | _ -> raise (Invalid_argument "unsupported tag extension")
   FORMAT_STAG_OF_STRING=Format.String_tag s
+  FORMAT_PP_OPT=Format.pp_print_option
   HAS_OCAML407_OR_408=yes
 else
   DYNLINK_INIT=Dynlink.init
@@ -144,6 +145,10 @@ else
   else
     HAS_OCAML407_OR_408=no
   endif
+  FORMAT_PP_OPT=fun ?(none=(fun _ () -> ())) pp fmt o -> \
+    match o with \
+    | None -> none fmt () \
+    | Some v -> pp fmt v
 endif
 
 ifeq ($(HAS_OCAML407_OR_408),yes)
@@ -169,6 +174,7 @@ src/libraries/stdlib/transitioning.ml: \
          -e 's/@FORMAT_STAG@/$(FORMAT_STAG)/g' \
          -e 's/@FORMAT_STRING_OF_STAG@/$(FORMAT_STRING_OF_STAG)/g' \
          -e 's/@FORMAT_STAG_OF_STRING@/$(FORMAT_STAG_OF_STRING)/g' \
+         -e 's/@FORMAT_PP_OPT@/$(FORMAT_PP_OPT)/g' \
         $< > $@
 	$(CHMOD_RO) $@
 

src/kernel_services/ast_printing/cabs_debug.ml

@@ -250,17 +250,17 @@ and pp_raw_stmt fmt = function
       pp_block bl1 pp_block bl2 pp_cabsloc loc
   |     THROW(e,loc) ->
     fprintf fmt "@[<hov 2>THROW %a, loc(%a)@]"
-      (Pretty_utils.pp_opt pp_exp) e pp_cabsloc loc
+      (Transitioning.Format.pp_print_option pp_exp) e pp_cabsloc loc
   |     TRY_CATCH(s,l,loc) ->
     let print_one_catch fmt (v,s) =
       fprintf fmt "@[<v 2>@[CATCH %a {@]@;%a@]@;}"
-        (Pretty_utils.pp_opt pp_single_name) v
+        (Transitioning.Format.pp_print_option pp_single_name) v
         pp_stmt s
     in
     fprintf fmt "@[<v 2>@[TRY %a (loc %a) {@]@;%a@]@;}"
       pp_stmt s
       pp_cabsloc loc
-      (Pretty_utils.pp_list ~sep:"@;" print_one_catch) l
+      (Format.pp_print_list ~pp_sep:Format.pp_print_cut print_one_catch) l
   |     CODE_ANNOT (_,_) -> fprintf fmt "CODE_ANNOT"
   |     CODE_SPEC _ -> fprintf fmt "CODE_SPEC"
 

src/libraries/stdlib/transitioning.ml.in

@@ -78,6 +78,8 @@ module Format = struct
     Format.pp_open_@FORMAT_STAG@ fmt s
   let pp_close_stag fmt () =
     Format.pp_close_@FORMAT_STAG@ fmt ()
+
+  let pp_print_option = @FORMAT_PP_OPT@
 end
 
 module Q = struct

src/libraries/stdlib/transitioning.mli

@@ -74,6 +74,8 @@ module Format: sig
     Format.formatter -> unit -> formatter_stag_functions
   val pp_open_stag : Format.formatter -> stag -> unit
   val pp_close_stag : Format.formatter -> unit -> unit
+  val pp_print_option: ?none:(Format.formatter -> unit -> unit) ->
+       (Format.formatter -> 'a -> unit) -> Format.formatter -> 'a option -> unit
 end
 
 (** {1 Zarith} *)