[gobject-introspection] repository: Add new public gi_type_info_extract_ffi_return_value() API

[Colin Walters <walters src gnome org>]

commit c2fc7cb45243aa9e0e1e5569cc742f69c76a671a
Author: Colin Walters <walters verbum org>
Date:   Thu Feb 16 16:58:59 2012 -0500

    repository: Add new public gi_type_info_extract_ffi_return_value() API
    
    Dealing with FFI and return values is very tricky; this API allows
    sharing the bits to do it between gobject-introspection and gjs (and
    potentially other FFI binding consumers).
    
    **NOTE** I swapped the order of the arguments, under the premise that
    out arguments should generally be last.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=668902

 girepository/gicallableinfo.c |   12 +++++-------
 girepository/girffi.h         |    6 ++++++
 2 files changed, 11 insertions(+), 7 deletions(-)
---
diff --git a/girepository/gicallableinfo.c b/girepository/gicallableinfo.c
index fec77b8..25372ff 100644
--- a/girepository/gicallableinfo.c
+++ b/girepository/gicallableinfo.c
@@ -366,12 +366,10 @@ g_callable_info_iterate_return_attributes (GICallableInfo  *info,
  * Also see the ffi_call man page - the storage requirements for return
  * values are "special".
  */
-typedef GIArgument GIFFIReturnValue;
-
-static void
-set_gargument_from_ffi_return_value (GITypeInfo                  *return_info,
-                                     GIArgument                  *arg,
-                                     GIFFIReturnValue            *ffi_value)
+void
+gi_type_info_extract_ffi_return_value (GITypeInfo                  *return_info,
+                                       GIFFIReturnValue            *ffi_value,
+                                       GIArgument                  *arg)
 {
     switch (g_type_info_get_tag (return_info)) {
     case GI_TYPE_TAG_INT8:
@@ -618,7 +616,7 @@ _g_callable_info_invoke (GIFunctionInfo *info,
     }
   else
     {
-      set_gargument_from_ffi_return_value(rinfo, return_value, &ffi_return_value);
+      gi_type_info_extract_ffi_return_value (rinfo, &ffi_return_value, return_value);
       success = TRUE;
     }
  out:
diff --git a/girepository/girffi.h b/girepository/girffi.h
index e976f92..56caff7 100644
--- a/girepository/girffi.h
+++ b/girepository/girffi.h
@@ -46,10 +46,16 @@ struct _GIFunctionInvoker {
   gpointer padding[3];
 };
 
+typedef GIArgument GIFFIReturnValue;
+
 ffi_type *    gi_type_tag_get_ffi_type            (GITypeTag type_tag, gboolean is_pointer);
 
 ffi_type *    g_type_info_get_ffi_type            (GITypeInfo           *info);
 
+void          gi_type_info_extract_ffi_return_value (GITypeInfo                  *return_info,
+                                                     GIFFIReturnValue            *ffi_value,
+                                                     GIArgument                  *arg);
+
 gboolean      g_function_info_prep_invoker        (GIFunctionInfo       *info,
                                                    GIFunctionInvoker    *invoker,
                                                    GError              **error);