Experimental support for a comment in the files' preamble in extraction.

Scheme comments are output on a single line because Ocaml's Format
module which serves as a backend to Pp has an integer, rather than a string
as identation value, so we cannot make it so that each new line in the
comment starts with ";; ".

I've tried something with Pp.ifb but it was hackish at best and had somewhat
strange results.

Known bug: as Pp.std_ppcmds is non-persistent, the comment is actually printed
only once per Extraction command, even if it outputs several files.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@15763 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 6 insertions, 2 deletions

diff --git a/plugins/extraction/extract_env.ml b/plugins/extraction/extract_env.ml
index 292ae7955..588fe0cf2 100644
--- a/plugins/extraction/extract_env.ml
+++ b/plugins/extraction/extract_env.ml
@@ -470,10 +470,14 @@ let print_structure_to_file (fn,si,mo) dry struc =
   (* Print the implementation *)
   let cout = if dry then None else Option.map open_out fn in
   let ft = formatter dry cout in
+  let file_comment =
+    let split_comment = Str.split (Str.regexp "[ \t\n]+") (file_comment ()) in
+    prlist_with_sep spc str split_comment
+  in
   begin try
     (* The real printing of the implementation *)
     set_phase Impl;
-    pp_with ft (d.preamble mo opened unsafe_needs);
+    pp_with ft (d.preamble mo file_comment opened unsafe_needs);
     pp_with ft (d.pp_struct struc);
     Option.iter close_out cout;
   with e ->
@@ -487,7 +491,7 @@ let print_structure_to_file (fn,si,mo) dry struc =
        let ft = formatter false (Some cout) in
        begin try
 	 set_phase Intf;
-	 pp_with ft (d.sig_preamble mo opened unsafe_needs);
+	 pp_with ft (d.sig_preamble mo file_comment opened unsafe_needs);
 	 pp_with ft (d.pp_sig (signature_of_structure struc));
 	 close_out cout;
        with e ->