fix compat

Author: hhugo

compiler/lib/ocaml_compiler.ml

@@ -284,5 +284,11 @@ module Cmo_format = struct
 
   let force_link (t : t) = t.cu_force_link
 
-  let hints_pos (t : t) = t.cu_hint
+  let hints_pos (t : t) = t.cu_hint [@@if ocaml_version >= (5, 3, 1)]
+
+  let hints_size (t : t) = t.cu_hintsize [@@if ocaml_version >= (5, 3, 1)]
+
+  let hints_size _ = 0 [@@if ocaml_version < (5, 3, 1)]
+
+  let hints_pos _ = 0 [@@if ocaml_version < (5, 3, 1)]
 end

compiler/lib/ocaml_compiler.mli

@@ -75,4 +75,6 @@ module Cmo_format : sig
   val imports : t -> (string * string option) list
 
   val hints_pos : t -> int
+
+  val hints_size : t -> int
 end

compiler/lib/parse_bytecode.ml

@@ -3196,7 +3196,7 @@ let from_cmo ?(includes = []) ?(include_cmis = false) ?(debug = false) compunit
     Debug.read_event_list debug_data ~crcs:[] ~includes ~orig:0 ic);
   if times () then Format.eprintf "    read debug events: %a@." Timer.print t;
   let hints = Hints.create () in
-  if Ocaml_compiler.Cmo_format.hints_pos compunit <> 0
+  if Ocaml_compiler.Cmo_format.hints_size compunit > 0
   then (
     seek_in ic (Ocaml_compiler.Cmo_format.hints_pos compunit);
     Hints.read hints ~orig:0 ic);
@@ -3221,7 +3221,7 @@ let from_cma ?(includes = []) ?(include_cmis = false) ?(debug = false) lib ic =
         then (
           seek_in ic compunit.Cmo_format.cu_debug;
           Debug.read_event_list debug_data ~crcs:[] ~includes ~orig:!orig ic);
-        if Ocaml_compiler.Cmo_format.hints_pos compunit <> 0
+        if Ocaml_compiler.Cmo_format.hints_size compunit > 0
         then (
           seek_in ic (Ocaml_compiler.Cmo_format.hints_pos compunit);
           Hints.read hints ~orig:!orig ic);