Use compressed marshaling to write .cmt, .cmti, .cmi, .cmo, .cma files

For .cmi, .cmt and .cmti files, the resulting files are 35-40% the size of
the uncompressed files.

For .cmo and .cma files, we compress only the debug info; this gives 50%
space savings for files with full debug info.

2 files changed, 6 insertions, 4 deletions

diff --git a/bytecomp/bytepackager.ml b/bytecomp/bytepackager.ml
index 449d423252..4ff00f2967 100644
--- a/bytecomp/bytepackager.ml
+++ b/bytecomp/bytepackager.ml
@@ -272,8 +272,9 @@ let package_object_files ~ppf_dump files targetfile targetname coercion =
       build_global_target ~ppf_dump oc targetname state components coercion in
     let pos_debug = pos_out oc in
     if !Clflags.debug && state.events <> [] then begin
-      output_value oc (List.rev state.events);
-      output_value oc (String.Set.elements state.debug_dirs);
+      Marshal.(to_channel oc (List.rev state.events) [Compression]);
+      Marshal.(to_channel oc (String.Set.elements state.debug_dirs)
+                             [Compression]);
     end;
     let force_link =
       List.exists (function
diff --git a/bytecomp/emitcode.ml b/bytecomp/emitcode.ml
index 9e70bebd9c..bd3c3f2fb5 100644
--- a/bytecomp/emitcode.ml
+++ b/bytecomp/emitcode.ml
@@ -416,8 +416,9 @@ let to_file outchan unit_name objfile ~required_globals code =
         (Filename.dirname (Location.absolute_path objfile))
         !debug_dirs;
       let p = pos_out outchan in
-      output_value outchan !events;
-      output_value outchan (String.Set.elements !debug_dirs);
+      Marshal.(to_channel outchan !events [Compression]);
+      Marshal.(to_channel outchan (String.Set.elements !debug_dirs)
+                          [Compression]);
       (p, pos_out outchan - p)
     end else
       (0, 0) in