[svn-r22123] update the VOL GET callbacks to use var_args instead of argc & argv

7 files changed, 258 insertions, 244 deletions

diff --git a/src/H5F.c b/src/H5F.c
index 72ed989..eaffc82 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -193,7 +193,7 @@ H5Fget_create_plist(hid_t uid)
     FUNC_ENTER_API(FAIL)
     H5TRACE1("i", "i", uid);
 
-    if(H5VL_file_get(uid, H5F_GET_FCPL, &ret_value, 0, NULL) < 0)
+    if(H5VL_file_get(uid, H5F_GET_FCPL, 1, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file creation properties")
 
 done:
@@ -230,7 +230,7 @@ H5Fget_access_plist(hid_t uid)
     FUNC_ENTER_API(FAIL)
     H5TRACE1("i", "i", uid);
 
-    if(H5VL_file_get(uid, H5F_GET_FAPL, &ret_value, 0, NULL) < 0)
+    if(H5VL_file_get(uid, H5F_GET_FAPL, 1, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file creation properties")
 
 done:
@@ -752,7 +752,7 @@ H5Fget_vfd_handle(hid_t uid, hid_t fapl, void **file_handle)
     if(!file_handle)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid file handle pointer")
 
-    if((ret_value = H5VL_file_get(uid, H5F_GET_VFD_HANDLE, &fapl, 1, file_handle)) < 0)
+    if((ret_value = H5VL_file_get(uid, H5F_GET_VFD_HANDLE, 2, file_handle, fapl)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file handle")
 
 done:
@@ -1979,7 +1979,7 @@ H5Fget_intent(hid_t uid, unsigned *intent_flags)
 
     /* If no intent flags were passed in, exit quietly */
     if(intent_flags) {
-        if((ret_value = H5VL_file_get(uid, H5F_GET_INTENT, (void *)intent_flags, 0, NULL)) < 0)
+        if((ret_value = H5VL_file_get(uid, H5F_GET_INTENT, 1, intent_flags)) < 0)
             HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file intent")
     }
 
@@ -2402,7 +2402,7 @@ H5Fget_freespace(hid_t uid)
     FUNC_ENTER_API(FAIL)
     H5TRACE1("Hs", "i", uid);
 
-    if(H5VL_file_get(uid, H5F_GET_FREE_SPACE, &ret_value, 0, NULL) < 0)
+    if(H5VL_file_get(uid, H5F_GET_FREE_SPACE, 1, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file free space")
 
 done:
@@ -2436,7 +2436,7 @@ H5Fget_filesize(hid_t uid, hsize_t *size)
     FUNC_ENTER_API(FAIL)
     H5TRACE2("e", "i*h", uid, size);
 
-    if((ret_value = H5VL_file_get(uid, H5F_GET_SIZE, (void *)size, 0, NULL)) < 0)
+    if((ret_value = H5VL_file_get(uid, H5F_GET_SIZE, 1, size)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file size")
 
 done:
@@ -2474,7 +2474,7 @@ H5Fget_mdc_config(hid_t uid, H5AC_cache_config_t *config_ptr)
     if((NULL == config_ptr) || (config_ptr->version != H5AC__CURR_CACHE_CONFIG_VERSION))
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Bad config_ptr")
 
-    if((ret_value = H5VL_file_get(uid, H5F_GET_MDC_CONF, (void *)config_ptr, 0, NULL)) < 0)
+    if((ret_value = H5VL_file_get(uid, H5F_GET_MDC_CONF, 1, config_ptr)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get mdc config")
 
 done:
@@ -2552,7 +2552,7 @@ H5Fget_mdc_hit_rate(hid_t uid, double *hit_rate_ptr)
     if(NULL == hit_rate_ptr)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "NULL hit rate pointer")
 
-    if((ret_value = H5VL_file_get(uid, H5F_GET_MDC_HR, (void *)hit_rate_ptr, 0, NULL)) < 0)
+    if((ret_value = H5VL_file_get(uid, H5F_GET_MDC_HR, 1, hit_rate_ptr)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get MDC hit rate")
 
 done:
@@ -2581,17 +2581,14 @@ herr_t
 H5Fget_mdc_size(hid_t uid, size_t *max_size_ptr, size_t *min_clean_size_ptr,
     size_t *cur_size_ptr, int *cur_num_entries_ptr)
 {
-    void       *argv[3];
     herr_t     ret_value = SUCCEED;     /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE5("e", "i*z*z*z*Is", uid, max_size_ptr, min_clean_size_ptr,
              cur_size_ptr, cur_num_entries_ptr);
 
-    argv[0] = (void *)max_size_ptr;
-    argv[1] = (void *)min_clean_size_ptr;
-    argv[2] = (void *)cur_size_ptr;
-    if((ret_value = H5VL_file_get(uid, H5F_GET_MDC_SIZE, (void *)cur_num_entries_ptr, 3, argv)) < 0)
+    if((ret_value = H5VL_file_get(uid, H5F_GET_MDC_SIZE, 4, max_size_ptr, 
+                                  min_clean_size_ptr, cur_size_ptr, cur_num_entries_ptr)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get MDC hit rate")
 
 done:
@@ -2672,20 +2669,17 @@ done:
 ssize_t
 H5Fget_name(hid_t uid, char *name/*out*/, size_t size)
 {
-    void          *argv[2];      /* arguments to the VOL callback */
     ssize_t       ret_value;
 
     FUNC_ENTER_API(FAIL)
     H5TRACE3("Zs", "ixz", uid, name, size);
 
     /* MSC - temp fix to handle later when all user level ids are of type UID */
-    if (H5I_FILE_PUBLIC == H5I_get_type(uid)) {
-        argv[0] = &ret_value;
-        argv[1] = &size;
-        if(H5VL_file_get(uid, H5F_GET_NAME, (void *)name, 2, argv) < 0)
+    if (H5I_FILE_PUBLIC == H5I_get_type(uid) || H5I_GROUP_PUBLIC == H5I_get_type(uid) ||
+        H5I_DATATYPE_PUBLIC == H5I_get_type(uid) || H5I_DATASET_PUBLIC == H5I_get_type(uid) ||
+        H5I_ATTRIBUTE_PUBLIC == H5I_get_type(uid)) {
+        if(H5VL_file_get(uid, H5F_GET_NAME, 3, name, &ret_value, size) < 0)
             HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file name")
-
-        ret_value = *((ssize_t *)argv[0]);
     }
     else {
         H5F_t         *f;           /* Top file in mount hierarchy */
@@ -2752,7 +2746,7 @@ H5Fget_info2(hid_t uid, H5F_info2_t *finfo)
     if(!finfo)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no info struct")
 
-    if((ret_value = H5VL_file_get(uid, H5F_GET_INFO, (void *)finfo, 0, NULL)) < 0)
+    if((ret_value = H5VL_file_get(uid, H5F_GET_INFO, 1, finfo)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file info")
 done:
     FUNC_LEAVE_API(ret_value)
@@ -2778,7 +2772,6 @@ ssize_t
 H5Fget_free_sections(hid_t uid, H5F_mem_t type, size_t nsects,
     H5F_sect_info_t *sect_info/*out*/)
 {
-    void          *argv[3];
     ssize_t       ret_value;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -2788,11 +2781,8 @@ H5Fget_free_sections(hid_t uid, H5F_mem_t type, size_t nsects,
     if(sect_info && nsects == 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "nsects must be > 0")
 
-    argv[0] = &ret_value;
-    argv[1] = &type;
-    argv[2] = &nsects;
-
-    if(H5VL_file_get(uid, H5F_GET_FREE_SECTIONS, (void *)sect_info, 3, argv) < 0)
+    if(H5VL_file_get(uid, H5F_GET_FREE_SECTIONS, 4, sect_info, &ret_value, 
+                     type, nsects) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file info")
 done:
     FUNC_LEAVE_API(ret_value)
diff --git a/src/H5G.c b/src/H5G.c
index 0ee943a..df50dd6 100644
--- a/src/H5G.c
+++ b/src/H5G.c
@@ -437,7 +437,7 @@ H5Gget_create_plist(hid_t uid)
     FUNC_ENTER_API(FAIL)
     H5TRACE1("i", "i", uid);
 
-    if(H5VL_group_get(uid, H5G_GET_GCPL, &ret_value, 0, NULL) < 0)
+    if(H5VL_group_get(uid, H5G_GET_GCPL, 1, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group creation properties")
 
 done:
@@ -459,15 +459,24 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5Gget_info(hid_t uid, H5G_info_t *grp_info)
+H5Gget_info(hid_t obj_id, H5G_info_t *grp_info)
 {
+    H5I_type_t  id_type;                /* Type of ID */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
-    H5TRACE2("e", "i*x", uid, grp_info);
+    H5TRACE2("e", "i*x", obj_id, grp_info);
 
-    if((ret_value = H5VL_group_get(uid, H5G_GET_INFO, (void *)grp_info, 0, NULL)) < 0)
+    /* Check args */
+    id_type = H5I_get_type(obj_id);
+    if(!(H5I_GROUP_PUBLIC == id_type || H5I_FILE_PUBLIC == id_type))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid argument")
+    if(!grp_info)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no info struct")
+
+    if((ret_value = H5VL_group_get(obj_id, H5G_GET_INFO, 1, grp_info)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
+
 done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Gget_info() */
@@ -490,19 +499,12 @@ herr_t
 H5Gget_info_by_name(hid_t loc_id, const char *name, H5G_info_t *grp_info,
     hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
-    H5G_loc_t   grp_loc;                /* Location used to open group */
-    H5G_name_t  grp_path;            	/* Opened object group hier. path */
-    H5O_loc_t   grp_oloc;            	/* Opened object object location */
-    hbool_t     loc_found = FALSE;      /* Location at 'name' found */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE4("e", "i*s*xi", loc_id, name, grp_info, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!name || !*name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
     if(!grp_info)
@@ -513,24 +515,10 @@ H5Gget_info_by_name(hid_t loc_id, const char *name, H5G_info_t *grp_info,
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
 
-    /* Set up opened group location to fill in */
-    grp_loc.oloc = &grp_oloc;
-    grp_loc.path = &grp_path;
-    H5G_loc_reset(&grp_loc);
-
-    /* Find the group object */
-    if(H5G_loc_find(&loc, name, &grp_loc/*out*/, lapl_id, H5AC_ind_dxpl_id) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "group not found")
-    loc_found = TRUE;
-
-    /* Retrieve the group's information */
-    if(H5G__obj_info(grp_loc.oloc, grp_info/*out*/, H5AC_ind_dxpl_id) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info")
+    if((ret_value = H5VL_group_get(loc_id, H5G_GET_INFO, 3, grp_info, name, lapl_id)) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
 done:
-    if(loc_found && H5G_loc_free(&grp_loc) < 0)
-        HDONE_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "can't free location")
-
     FUNC_LEAVE_API(ret_value)
 } /* end H5Gget_info_by_name() */
 
@@ -553,11 +541,6 @@ herr_t
 H5Gget_info_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, H5G_info_t *grp_info, hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
-    H5G_loc_t   grp_loc;                /* Location used to open group */
-    H5G_name_t  grp_path;            	/* Opened object group hier. path */
-    H5O_loc_t   grp_oloc;            	/* Opened object object location */
-    hbool_t     loc_found = FALSE;      /* Entry at 'name' found */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -565,8 +548,6 @@ H5Gget_info_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
              lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!group_name || !*group_name)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name specified")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
@@ -581,25 +562,11 @@ H5Gget_info_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
 
-    /* Set up opened group location to fill in */
-    grp_loc.oloc = &grp_oloc;
-    grp_loc.path = &grp_path;
-    H5G_loc_reset(&grp_loc);
-
-    /* Find the object's location, according to the order in the index */
-    if(H5G_loc_find_by_idx(&loc, group_name, idx_type, order, n, &grp_loc/*out*/, lapl_id, H5AC_ind_dxpl_id) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "group not found")
-    loc_found = TRUE;
-
-    /* Retrieve the group's information */
-    if(H5G__obj_info(grp_loc.oloc, grp_info/*out*/, H5AC_ind_dxpl_id) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info")
+    if((ret_value = H5VL_group_get(loc_id, H5G_GET_INFO, 6, grp_info, group_name, 
+                                   idx_type, order, n, lapl_id)) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
 done:
-    /* Release the object location */
-    if(loc_found && H5G_loc_free(&grp_loc) < 0)
-        HDONE_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "can't free location")
-
     FUNC_LEAVE_API(ret_value)
 } /* end H5Gget_info_by_idx() */
 
diff --git a/src/H5O.c b/src/H5O.c
index 1f94a14..23632b1 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -233,7 +233,6 @@ H5Oopen(hid_t loc_id, const char *name, hid_t lapl_id)
     hid_t       ret_value = FAIL;
     void       *location = NULL; /* a pointer to VOL specific token that indicates 
                                     the location of the object */
-    void       *argv[2];
 
     FUNC_ENTER_API(FAIL)
     H5TRACE3("i", "i*si", loc_id, name, lapl_id);
@@ -241,17 +240,19 @@ H5Oopen(hid_t loc_id, const char *name, hid_t lapl_id)
     if(!name || !*name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
 
-    argv[0] = (void *)name;
-    argv[1] = &lapl_id;
-
     /* Get the token for the Object location through the VOL */
-    if(H5VL_object_lookup (loc_id, H5O_LOOKUP_BY_NAME, &location, 2, argv) < 0)
+    if(H5VL_object_lookup (loc_id, H5O_LOOKUP_BY_NAME, 3, &location, name, lapl_id) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to locate object")
 
     /* Open the object through the VOL */
     if((ret_value = H5VL_object_open(loc_id, location, lapl_id)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open object")
+
 done:
+    if (NULL != location) {
+        free (location);
+        location = NULL;
+    }
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oopen() */
 
@@ -284,7 +285,6 @@ H5Oopen_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, hid_t lapl_id)
 {
     void       *location = NULL;
-    void       *argv[5];
     hid_t       ret_value = FAIL;
 
     FUNC_ENTER_API(FAIL)
@@ -303,14 +303,9 @@ H5Oopen_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
 
-    argv[0] = (void *)group_name;
-    argv[1] = &idx_type;
-    argv[2] = &order;
-    argv[3] = &n;
-    argv[4] = &lapl_id;
-    
     /* Get the token for the Object location through the VOL */
-    if(H5VL_object_lookup (loc_id, H5O_LOOKUP_BY_IDX, &location, 5, argv) < 0)
+    if(H5VL_object_lookup (loc_id, H5O_LOOKUP_BY_IDX, 6, &location, group_name,
+                           idx_type, order, n, lapl_id) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to locate object")
 
     /* Open the object through the VOL */
@@ -318,6 +313,10 @@ H5Oopen_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open object")
 
 done:
+    if (NULL != location) {
+        free (location);
+        location = NULL;
+    }
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oopen_by_idx() */
 
@@ -362,16 +361,13 @@ H5Oopen_by_addr(hid_t loc_id, haddr_t addr)
 {
     hid_t       lapl_id = H5P_LINK_ACCESS_DEFAULT; /* lapl to use to open this object */
     void       *location = NULL;
-    void       *argv[1];
     hid_t       ret_value = FAIL;
 
     FUNC_ENTER_API(FAIL)
     H5TRACE2("i", "ia", loc_id, addr);
 
-    argv[0] = &addr;
-    
     /* Get the token for the Object location through the VOL */
-    if(H5VL_object_lookup (loc_id, H5O_LOOKUP_BY_ADDR, &location, 1, argv) < 0)
+    if(H5VL_object_lookup (loc_id, H5O_LOOKUP_BY_ADDR, 2, &location, addr) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to locate object")
 
     /* Open the object through the VOL */
@@ -379,7 +375,10 @@ H5Oopen_by_addr(hid_t loc_id, haddr_t addr)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open object")
 
 done:
-
+    if (NULL != location) {
+        free (location);
+        location = NULL;
+    }
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oopen_by_addr() */
 
@@ -582,8 +581,6 @@ done:
 herr_t
 H5Oget_info(hid_t loc_id, H5O_info_t *oinfo)
 {
-    void        *argv[1];
-    hid_t       lapl_id;
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -593,10 +590,7 @@ H5Oget_info(hid_t loc_id, H5O_info_t *oinfo)
     if(!oinfo)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no info struct")
 
-    lapl_id = H5P_LINK_ACCESS_DEFAULT;
-    argv[0] = &lapl_id;
-
-    if((ret_value = H5VL_object_get(loc_id, H5O_GET_INFO, (void *)oinfo, 1, argv)) < 0)
+    if((ret_value = H5VL_object_get(loc_id, H5O_GET_INFO, 1, oinfo)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get object info")
 
 done:
@@ -620,7 +614,6 @@ done:
 herr_t
 H5Oget_info_by_name(hid_t loc_id, const char *name, H5O_info_t *oinfo, hid_t lapl_id)
 {
-    void        *argv[2];
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -637,10 +630,9 @@ H5Oget_info_by_name(hid_t loc_id, const char *name, H5O_info_t *oinfo, hid_t lap
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
 
-    argv[0] = &lapl_id;
-    argv[1] = (void *)name;
-    if((ret_value = H5VL_object_get(loc_id, H5O_GET_INFO, (void *)oinfo, 2, argv)) < 0)
+    if((ret_value = H5VL_object_get(loc_id, H5O_GET_INFO, 3, oinfo, name, lapl_id)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get object info")
+
 done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oget_info_by_name() */
@@ -664,7 +656,6 @@ herr_t
 H5Oget_info_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, H5O_info_t *oinfo, hid_t lapl_id)
 {
-    void        *argv[5];
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -686,14 +677,10 @@ H5Oget_info_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
 
-    argv[0] = (void *)group_name;
-    argv[1] = &idx_type;
-    argv[2] = &order;
-    argv[3] = &n;
-    argv[4] = &lapl_id;
-
-    if((ret_value = H5VL_object_get(loc_id, H5O_GET_INFO, (void *)oinfo, 5, argv)) < 0)
+    if((ret_value = H5VL_object_get(loc_id, H5O_GET_INFO, 6, oinfo, group_name, idx_type, 
+                                    order, n, lapl_id)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get object info")
+
 done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oget_info_by_idx() */
@@ -804,19 +791,14 @@ done:
 ssize_t
 H5Oget_comment(hid_t loc_id, char *comment, size_t bufsize)
 {
-    void       *argv[2];
     ssize_t     ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE3("Zs", "i*sz", loc_id, comment, bufsize);
 
-    argv[0] = &ret_value;
-    argv[1] = &bufsize;
-
-    if(H5VL_object_get(loc_id, H5O_GET_COMMENT, (void *)comment, 2, argv) < 0)
-        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get object comment")
+    if(H5VL_object_get(loc_id, H5O_GET_COMMENT, 3, &ret_value, comment, bufsize) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get object info")
 
-    ret_value = *((ssize_t *)argv[0]);
 done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oget_comment() */
@@ -842,7 +824,6 @@ ssize_t
 H5Oget_comment_by_name(hid_t loc_id, const char *name, char *comment, size_t bufsize,
     hid_t lapl_id)
 {
-    void       *argv[4];
     ssize_t     ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -857,14 +838,9 @@ H5Oget_comment_by_name(hid_t loc_id, const char *name, char *comment, size_t buf
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
 
-    argv[0] = &ret_value;
-    argv[1] = &bufsize;
-    argv[2] = (void *)name;
-    argv[3] = &lapl_id;
-    if(H5VL_object_get(loc_id, H5O_GET_COMMENT, (void *)comment, 4, argv) < 0)
-        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get object comment")
-
-    ret_value = *((ssize_t *)argv[0]);
+    if(H5VL_object_get(loc_id, H5O_GET_COMMENT, 5, &ret_value, comment, bufsize, 
+                       name, lapl_id) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get object info")
 
 done:
     FUNC_LEAVE_API(ret_value)
diff --git a/src/H5VL.c b/src/H5VL.c
index 126a3b0..7f68356 100644
--- a/src/H5VL.c
+++ b/src/H5VL.c
@@ -740,15 +740,18 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL_file_get(hid_t uid, H5VL_file_get_t get_type, void *data, int argc, void **argv)
+H5VL_file_get(hid_t uid, H5VL_file_get_t get_type, int num_args, ...)
 {
     H5I_t            *uid_info;              /* user id structure */
+    va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
 
     FUNC_ENTER_NOAPI(FAIL)
 
     /* Check/fix arguments. */
-    if(H5I_FILE_PUBLIC != H5I_get_type(uid))
+    if (H5I_FILE_PUBLIC != H5I_get_type(uid) && H5I_GROUP_PUBLIC != H5I_get_type(uid) &&
+        H5I_DATATYPE_PUBLIC != H5I_get_type(uid) && H5I_DATASET_PUBLIC != H5I_get_type(uid) &&
+        H5I_ATTRIBUTE_PUBLIC != H5I_get_type(uid))
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a user ID")
 
     /* get the ID struct */
@@ -757,8 +760,11 @@ H5VL_file_get(hid_t uid, H5VL_file_get_t get_type, void *data, int argc, void **
 
     if(NULL == uid_info->vol_plugin->file_cls.get)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `file get' method")
-    if((ret_value = (uid_info->vol_plugin->file_cls.get)(uid_info->obj_id, get_type, data, argc, argv)) < 0)
+
+    va_start(arguments, num_args);
+    if((ret_value = (uid_info->vol_plugin->file_cls.get)(uid_info->obj_id, get_type, num_args, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "get failed")
+    va_end(arguments);
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -928,9 +934,10 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL_group_get(hid_t uid, H5VL_group_get_t get_type, void *data, int argc, void **argv)
+H5VL_group_get(hid_t uid, H5VL_group_get_t get_type, int num_args, ...)
 {
     H5I_t            *uid_info;              /* user id structure */
+    va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -945,8 +952,12 @@ H5VL_group_get(hid_t uid, H5VL_group_get_t get_type, void *data, int argc, void
 
     if(NULL == uid_info->vol_plugin->group_cls.get)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `group get' method")
-    if((ret_value = (uid_info->vol_plugin->group_cls.get)(uid_info->obj_id, get_type, data, argc, argv)) < 0)
+
+    va_start (arguments, num_args);
+    if((ret_value = (uid_info->vol_plugin->group_cls.get)(uid_info->obj_id, get_type, 
+                                                          num_args, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "get failed")
+    va_end (arguments);
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1100,9 +1111,10 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL_object_lookup(hid_t uid, H5VL_object_lookup_t lookup_type, void **location, int argc, void **argv)
+H5VL_object_lookup(hid_t uid, H5VL_object_lookup_t lookup_type, int num_args, ...)
 {
     H5I_t            *uid_info;              /* user id structure */
+    va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -1117,10 +1129,12 @@ H5VL_object_lookup(hid_t uid, H5VL_object_lookup_t lookup_type, void **location,
 
     if(NULL == uid_info->vol_plugin->object_cls.lookup)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `object lookup' method")
+
+    va_start (arguments, num_args);
     if((ret_value = (uid_info->vol_plugin->object_cls.lookup)(uid_info->obj_id, lookup_type, 
-                                                              location, argc, argv)) < 0)
+                                                              num_args, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "lookup of object location failed")
-
+    va_end (arguments);
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5VL_object_lookup() */
@@ -1141,9 +1155,10 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL_object_get(hid_t uid, H5VL_object_get_t get_type, void *data, int argc, void **argv)
+H5VL_object_get(hid_t uid, H5VL_object_get_t get_type, int num_args, ...)
 {
     H5I_t            *uid_info;              /* user id structure */
+    va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -1159,10 +1174,12 @@ H5VL_object_get(hid_t uid, H5VL_object_get_t get_type, void *data, int argc, voi
 
     if(NULL == uid_info->vol_plugin->object_cls.get)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `object get' method")
+
+    va_start (arguments, num_args);
     if((ret_value = (uid_info->vol_plugin->object_cls.get)(uid_info->obj_id, get_type, 
-                                                           data, argc, argv)) < 0)
+                                                           num_args, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "get failed")
-
+    va_end (arguments);
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5VL_object_get() */
diff --git a/src/H5VLnative.c b/src/H5VLnative.c
index ae5ec4e..2fd48e6 100644
--- a/src/H5VLnative.c
+++ b/src/H5VLnative.c
@@ -61,7 +61,7 @@ static herr_t H5VL_native_file_close(hid_t fid);
 static hid_t  H5VL_native_file_create(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id);
 static herr_t H5VL_native_file_flush(hid_t fid, H5F_scope_t scope);
 static herr_t H5VL_native_file_get(hid_t file_id, H5VL_file_get_t get_type, 
-                                   void *data, int argc, void **argv);
+                                   int num_args, va_list arguments);
 
 static hid_t H5VL_native_dataset_create(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
                                         hid_t lcpl_id, hid_t dcpl_id, hid_t dapl_id);
@@ -80,15 +80,15 @@ static hid_t H5VL_native_group_create(hid_t loc_id, const char *name, hid_t lcpl
                                       hid_t gcpl_id, hid_t gapl_id);
 static hid_t H5VL_native_group_open(hid_t loc_id, const char *name, hid_t gapl_id);
 static herr_t H5VL_native_group_close(hid_t group_id);
-static herr_t H5VL_native_group_get(hid_t file_id, H5VL_group_get_t get_type, 
-                                    void *data, int argc, void **argv);
+static herr_t H5VL_native_group_get(hid_t obj_id, H5VL_group_get_t get_type, 
+                                    int num_args, va_list arguments);
 
 static hid_t H5VL_native_object_open(hid_t loc_id, void *location, hid_t lapl_id);
 static herr_t H5VL_native_object_close(hid_t object_id);
-static herr_t H5VL_native_object_get(hid_t id, H5VL_object_get_t get_type, void *data, 
-                                     int argc, void **argv);
+static herr_t H5VL_native_object_get(hid_t id, H5VL_object_get_t get_type, 
+                                     int num_args, va_list arguments);
 static herr_t H5VL_native_object_lookup(hid_t loc_id, H5VL_object_lookup_t lookup_type, 
-                                        void **location, int argc, void **argv);
+                                        int num_args, va_list arguments);
 
 static const H5VL_class_t H5VL_native_g = {
     "native",					/* name */
@@ -540,7 +540,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5VL_native_file_get(hid_t obj_id, H5VL_file_get_t get_type, void *data, int argc, void **argv)
+H5VL_native_file_get(hid_t obj_id, H5VL_file_get_t get_type, int num_args, va_list arguments)
 {
     H5F_t	*f = NULL;              /* File struct */
     herr_t      ret_value = SUCCEED;    /* Return value */
@@ -564,65 +564,70 @@ H5VL_native_file_get(hid_t obj_id, H5VL_file_get_t get_type, void *data, int arg
     /* H5Fget_access_plist */
     case H5F_GET_FAPL:
         {
-            hid_t plist_id;
+            hid_t *plist_id = va_arg (arguments, hid_t *);
 
             /* Retrieve the file's access property list */
-            if((plist_id = H5F_get_access_plist(f, TRUE)) < 0)
+            if((*plist_id = H5F_get_access_plist(f, TRUE)) < 0)
                 HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get file access property list")
-            *((hid_t *)data) = plist_id;
             break;
         }
     /* H5Fget_create_plist */
     case H5F_GET_FCPL:
         {
             H5P_genplist_t *plist;      /* Property list */
-            hid_t plist_id;
+            hid_t *plist_id = va_arg (arguments, hid_t *);
 
             if(NULL == (plist = (H5P_genplist_t *)H5I_object(f->shared->fcpl_id)))
                 HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
 
             /* Create the property list object to return */
-            if((plist_id = H5P_copy_plist(plist, TRUE)) < 0)
+            if((*plist_id = H5P_copy_plist(plist, TRUE)) < 0)
                 HGOTO_ERROR(H5E_INTERNAL, H5E_CANTINIT, FAIL, "unable to copy file creation properties")
-            *((hid_t *)data) = plist_id;
+
             break;
         }
     /* H5Fget_filesize */
     case H5F_GET_SIZE:
         {
             haddr_t    eof;                     /* End of file address */
+            hsize_t    *ret = va_arg (arguments, hsize_t *);
 
             /* Go get the actual file size */
             if(HADDR_UNDEF == (eof = H5FDget_eof(f->shared->lf)))
                 HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to get file size")
-            *((hsize_t *)data) = (hsize_t)eof;
+            *ret = (hsize_t)eof;
             break;
         }
     /* H5Fget_freespace */
     case H5F_GET_FREE_SPACE:
         {
             hsize_t	tot_space;	/* Amount of free space in the file */
+            hssize_t    *ret = va_arg (arguments, hssize_t *);
 
             /* Go get the actual amount of free space in the file */
             if(H5MF_get_freespace(f, H5AC_ind_dxpl_id, &tot_space, NULL) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to check free space for file")
-            *((hssize_t *)data) = (hssize_t)tot_space;
+            *ret = (hssize_t)tot_space;
             break;
         }
     case H5F_GET_FREE_SECTIONS:
         {
+            H5F_sect_info_t *sect_info = va_arg (arguments, H5F_sect_info_t *);
+            ssize_t         *ret       = va_arg (arguments, ssize_t *);
+            H5F_mem_t       type       = va_arg (arguments, H5F_mem_t);
+            size_t          nsects     = va_arg (arguments, size_t);
+
             /* Go get the free-space section information in the file */
-            if((*((ssize_t *)argv[0]) = H5MF_get_free_sections(f, H5AC_ind_dxpl_id, 
-                                                   *((H5F_mem_t *)argv[1]), 
-                                                   *((size_t *)argv[2]), 
-                                                   (H5F_sect_info_t *)data)) < 0)
+            if((*ret = H5MF_get_free_sections(f, H5AC_ind_dxpl_id, 
+                                              type, nsects, sect_info)) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to check free space for file")
             break;
         }
     /* H5Fget_info2 */
     case H5F_GET_INFO:
         {
-            H5F_info2_t *finfo = (H5F_info2_t *)data;
+            H5F_info2_t *finfo = va_arg (arguments, H5F_info2_t *);
+
             /* For file IDs, get the file object directly */
             /* (This prevents the H5G_loc() call from returning the file pointer for
              * the top file in a mount hierarchy)
@@ -656,22 +661,25 @@ H5VL_native_file_get(hid_t obj_id, H5VL_file_get_t get_type, void *data, int arg
     /* H5Fget_intent */
     case H5F_GET_INTENT:
         {
+            unsigned *ret = va_arg (arguments, unsigned *);
+
             /* HDF5 uses some flags internally that users don't know about.
              * Simplify things for them so that they only get either H5F_ACC_RDWR
              * or H5F_ACC_RDONLY.
              */
             if(H5F_INTENT(f) & H5F_ACC_RDWR)
-                *((unsigned *)data) = H5F_ACC_RDWR;
+                *ret = H5F_ACC_RDWR;
             else
-                *((unsigned *)data) = H5F_ACC_RDONLY;
+                *ret = H5F_ACC_RDONLY;
             break;
         }
     /* H5Fget_name */
     case H5F_GET_NAME:
         {
-            size_t    len, size = *((size_t *)argv[1]);
-            ssize_t   ret;
-            char      *name = (char *)data;
+            char      *name = va_arg (arguments, char *);
+            ssize_t   *ret  = va_arg (arguments, ssize_t *);
+            size_t     size = va_arg (arguments, size_t);
+            size_t     len;
 
             len = HDstrlen(H5F_OPEN_NAME(f));
 
@@ -682,50 +690,56 @@ H5VL_native_file_get(hid_t obj_id, H5VL_file_get_t get_type, void *data, int arg
             } /* end if */
 
             /* Set the return value for the API call */
-            ret = (ssize_t)len;
-            memcpy (argv[0], &ret, sizeof(ssize_t));
-
+            *ret = (ssize_t)len;
             break;
         }
     /* H5Fget_vfd_handle */
     case H5F_GET_VFD_HANDLE:
         {
-            hid_t fapl;
+            void **file_handle = va_arg (arguments, void **);
+            hid_t  fapl        = va_arg (arguments, hid_t);
 
-            fapl = *((hid_t *)data);
             /* Retrieve the VFD handle for the file */
-            if(H5F_get_vfd_handle(f, fapl, argv) < 0)
+            if(H5F_get_vfd_handle(f, fapl, file_handle) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't retrieve VFD handle")
             break;
         }
     /* H5Fget_mdc_config */
     case H5F_GET_MDC_CONF:
         {
+            H5AC_cache_config_t *config_ptr = va_arg (arguments, H5AC_cache_config_t *);
+
             /* Go get the resize configuration */
-            if(H5AC_get_cache_auto_resize_config(f->shared->cache, (H5AC_cache_config_t *)data) < 0)
+            if(H5AC_get_cache_auto_resize_config(f->shared->cache, config_ptr) < 0)
                 HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5AC_get_cache_auto_resize_config() failed.")
             break;
         }
     /* H5Fget_mdc_hit_rate */
     case H5F_GET_MDC_HR:
         {
+            double *hit_rate_ptr = va_arg (arguments, double *);
+
             /* Go get the current hit rate */
-            if(H5AC_get_cache_hit_rate(f->shared->cache, (double *)data) < 0)
+            if(H5AC_get_cache_hit_rate(f->shared->cache, hit_rate_ptr) < 0)
                 HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5AC_get_cache_hit_rate() failed.")
             break;
         }
     /* H5Fget_mdc_size */
     case H5F_GET_MDC_SIZE:
         {
-            int32_t    cur_num_entries;
+            size_t *max_size_ptr        = va_arg (arguments, size_t *);
+            size_t *min_clean_size_ptr  = va_arg (arguments, size_t *);
+            size_t *cur_size_ptr        = va_arg (arguments, size_t *); 
+            int    *cur_num_entries_ptr = va_arg (arguments, int *); 
+            int32_t cur_num_entries;
 
             /* Go get the size data */
-            if(H5AC_get_cache_size(f->shared->cache, (size_t *)argv[0], (size_t *)argv[1], 
-                                   (size_t *)argv[2], &cur_num_entries) < 0)
+            if(H5AC_get_cache_size(f->shared->cache, max_size_ptr, min_clean_size_ptr, 
+                                   cur_size_ptr, &cur_num_entries) < 0)
                 HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5AC_get_cache_size() failed.")
 
-            if(data != NULL)
-                *((int *)data) = (int)cur_num_entries;   
+            if(cur_num_entries_ptr != NULL)
+                *cur_num_entries_ptr = (int)cur_num_entries;
             break;
         }
     default:
@@ -899,10 +913,13 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5VL_native_group_get(hid_t obj_id, H5VL_group_get_t get_type, void *data, int argc, void **argv)
+H5VL_native_group_get(hid_t obj_id, H5VL_group_get_t get_type, int num_args, va_list arguments)
 {
+    H5G_loc_t   grp_loc;                /* Location used to open group */
+    hbool_t     loc_found = FALSE;      /* Location at 'name' found */
+    hid_t	*new_gcpl_id, new_id = FAIL;
     herr_t      ret_value = SUCCEED;    /* Return value */
-    hid_t	new_gcpl_id = FAIL;
+
     FUNC_ENTER_NOAPI_NOINIT
 
     switch (get_type) {
@@ -916,7 +933,8 @@ H5VL_native_group_get(hid_t obj_id, H5VL_group_get_t get_type, void *data, int a
             H5G_t		*grp = NULL;
             H5P_genplist_t      *gcpl_plist;
             H5P_genplist_t      *new_plist;
-
+            
+            new_gcpl_id = va_arg (arguments, hid_t *);
             /* Check args */
             if(NULL == (grp = (H5G_t *)H5I_object_verify(obj_id, H5I_GROUP)))
                 HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a group")
@@ -924,9 +942,9 @@ H5VL_native_group_get(hid_t obj_id, H5VL_group_get_t get_type, void *data, int a
             /* Copy the default group creation property list */
             if(NULL == (gcpl_plist = (H5P_genplist_t *)H5I_object(H5P_LST_GROUP_CREATE_g)))
                 HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get default group creation property list")
-            if((new_gcpl_id = H5P_copy_plist(gcpl_plist, TRUE)) < 0)
+            if((new_id = H5P_copy_plist(gcpl_plist, TRUE)) < 0)
                 HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "unable to copy the creation property list")
-            if(NULL == (new_plist = (H5P_genplist_t *)H5I_object(new_gcpl_id)))
+            if(NULL == (new_plist = (H5P_genplist_t *)H5I_object(new_id)))
                 HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
 
             /* Retrieve any object creation properties */
@@ -973,43 +991,86 @@ H5VL_native_group_get(hid_t obj_id, H5VL_group_get_t get_type, void *data, int a
             } /* end if */
 
             /* Set the return value */
-            *((hid_t *)data) = new_gcpl_id;
+            *new_gcpl_id = new_id;
             break;
         }
     /* H5Fget_info2 */
     case H5G_GET_INFO:
         {
-            H5I_type_t  id_type;                /* Type of ID */
-            H5G_loc_t	loc;                    /* Location of group */
-            H5G_info_t  *grp_info = (H5G_info_t *)data;
-
-            /* Check args */
-            id_type = H5I_get_type(obj_id);
-            if(!(H5I_GROUP == id_type || H5I_FILE == id_type))
-                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid argument")
-            if(!grp_info)
-                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no info struct")
+            H5G_loc_t	loc;
+            H5G_info_t  *grp_info = va_arg (arguments, H5G_info_t *);
 
             /* Get group location */
             if(H5G_loc(obj_id, &loc) < 0)
                 HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
 
-            /* Retrieve the group's information */
-            if(H5G__obj_info(loc.oloc, grp_info/*out*/, H5AC_ind_dxpl_id) < 0)
-                HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info")
+            /* Retrieve the object's information */
+            if(1 == num_args) {                
+                /* Retrieve the group's information */
+                if(H5G__obj_info(loc.oloc, grp_info/*out*/, H5AC_ind_dxpl_id) < 0)
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info")
+            }
+            else if(3 == num_args) {
+                H5G_name_t  grp_path;            	/* Opened object group hier. path */
+                H5O_loc_t   grp_oloc;            	/* Opened object object location */
+                char *name    = va_arg (arguments, char *);
+                hid_t lapl_id = va_arg (arguments, hid_t);
+
+                /* Set up opened group location to fill in */
+                grp_loc.oloc = &grp_oloc;
+                grp_loc.path = &grp_path;
+                H5G_loc_reset(&grp_loc);
+
+                /* Find the group object */
+                if(H5G_loc_find(&loc, name, &grp_loc/*out*/, lapl_id, H5AC_ind_dxpl_id) < 0)
+                    HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "group not found")
+                loc_found = TRUE;
+
+                /* Retrieve the group's information */
+                if(H5G__obj_info(grp_loc.oloc, grp_info/*out*/, H5AC_ind_dxpl_id) < 0)
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info")
+            }
+            else if (6 == num_args) {
+                H5G_name_t  grp_path;            	/* Opened object group hier. path */
+                H5O_loc_t   grp_oloc;            	/* Opened object object location */
+                char              *group_name =  va_arg (arguments, char *);
+                H5_index_t        idx_type    =  va_arg (arguments, H5_index_t);
+                H5_iter_order_t   order       =  va_arg (arguments, H5_iter_order_t);
+                hsize_t           n           =  va_arg (arguments, hsize_t);
+                hid_t             lapl_id     =  va_arg (arguments, hid_t);
+
+                /* Set up opened group location to fill in */
+                grp_loc.oloc = &grp_oloc;
+                grp_loc.path = &grp_path;
+                H5G_loc_reset(&grp_loc);
+
+                /* Find the object's location, according to the order in the index */
+                if(H5G_loc_find_by_idx(&loc, group_name, idx_type, order, n, &grp_loc/*out*/, lapl_id, H5AC_ind_dxpl_id) < 0)
+                    HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "group not found")
+                loc_found = TRUE;
+
+                /* Retrieve the group's information */
+                if(H5G__obj_info(grp_loc.oloc, grp_info/*out*/, H5AC_ind_dxpl_id) < 0)
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info")
+            }
             break;
         }
     default:
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from group")
     }
+
 done:
     if (H5G_GET_GCPL == get_type) {
-        if(*((hid_t *)data) < 0) {
-            if(new_gcpl_id > 0)
-                if(H5I_dec_app_ref(new_gcpl_id) < 0)
+        if(*new_gcpl_id < 0) {
+            if(new_id > 0)
+                if(H5I_dec_app_ref(new_id) < 0)
                     HDONE_ERROR(H5E_SYM, H5E_CANTDEC, FAIL, "can't free")
         } /* end if */
     }
+    if (H5G_GET_INFO == get_type) {
+        if(loc_found && H5G_loc_free(&grp_loc) < 0)
+            HDONE_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "can't free location")
+    }
     FUNC_LEAVE_NOAPI(ret_value)
 }
 
@@ -1112,7 +1173,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5VL_native_object_get(hid_t id, H5VL_object_get_t get_type, void *data, int argc, void **argv)
+H5VL_native_object_get(hid_t id, H5VL_object_get_t get_type, int num_args, va_list arguments)
 {
     herr_t      ret_value = SUCCEED;    /* Return value */
     H5G_loc_t	loc;                    /* Location of group */
@@ -1128,27 +1189,29 @@ H5VL_native_object_get(hid_t id, H5VL_object_get_t get_type, void *data, int arg
     /* H5Oget_info / H5Oget_info_by_name / H5Oget_info_by_idx */
     case H5O_GET_INFO:
         {
-            H5O_info_t  *obj_info = (H5O_info_t *)data;
+            H5O_info_t  *obj_info = va_arg (arguments, H5O_info_t *);
+
             /* Retrieve the object's information */
-            if(1 == argc) {
+            if(1 == num_args) {
                 if(H5G_loc_info(&loc, ".", TRUE, obj_info/*out*/, H5P_LINK_ACCESS_DEFAULT, 
                                 H5AC_ind_dxpl_id) < 0)
                     HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "object not found")
             }
-            else if(2 == argc) {
-                hid_t lapl_id = *((hid_t *)argv[0]);
-                char *name = (char *)argv[1];
+            else if(3 == num_args) {
+                char *name    = va_arg (arguments, char *);
+                hid_t lapl_id = va_arg (arguments, hid_t);
+
                 if(H5G_loc_info(&loc, name, TRUE, obj_info/*out*/, lapl_id, H5AC_ind_dxpl_id) < 0)
                     HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "object not found")
             }
-            else if (5 == argc) {
-                H5G_name_t  obj_path;            	/* Opened object group hier. path */
-                H5O_loc_t   obj_oloc;            	/* Opened object object location */
-                char       *group_name = (char *)argv[0];
-                H5_index_t  idx_type = *((H5_index_t *)argv[1]);
-                H5_iter_order_t order = *((H5_iter_order_t *)argv[2]);
-                hsize_t     n = *((hsize_t *)argv[3]);
-                hid_t       lapl_id = *((hid_t *)argv[4]);
+            else if (6 == num_args) {
+                H5G_name_t        obj_path;            	/* Opened object group hier. path */
+                H5O_loc_t         obj_oloc;            	/* Opened object object location */
+                char              *group_name =  va_arg (arguments, char *);
+                H5_index_t        idx_type    =  va_arg (arguments, H5_index_t);
+                H5_iter_order_t   order       =  va_arg (arguments, H5_iter_order_t);
+                hsize_t           n           =  va_arg (arguments, hsize_t);
+                hid_t             lapl_id     =  va_arg (arguments, hid_t);
                 
                 /* Set up opened group location to fill in */
                 obj_loc.oloc = &obj_oloc;
@@ -1169,26 +1232,24 @@ H5VL_native_object_get(hid_t id, H5VL_object_get_t get_type, void *data, int arg
     /* H5Oget_comment / H5Oget_comment_by_name */
     case H5O_GET_COMMENT:
         {
-            size_t   bufsize = *((size_t *)argv[1]);
-            ssize_t   ret;
-            char      *comment = (char *)data;
+            ssize_t  *ret     =  va_arg (arguments, ssize_t *);
+            char     *comment =  va_arg (arguments, char *);
+            size_t   bufsize  =  va_arg (arguments, size_t);
 
-            if(2 == argc) {
+            if(3 == num_args) {
                 /* Retrieve the object's comment */
-                if((ret = H5G_loc_get_comment(&loc, ".", comment/*out*/, bufsize, 
+                if((*ret = H5G_loc_get_comment(&loc, ".", comment/*out*/, bufsize, 
                                               H5P_LINK_ACCESS_DEFAULT, H5AC_ind_dxpl_id)) < 0)
                     HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "object not found")
             }
-            else if(4 == argc) {
-                char *name = (char *) argv[2];
-                hid_t lapl_id = *((hid_t *)argv[3]);
+            else if(5 == num_args) {
+                char *name    = va_arg (arguments, char *);
+                hid_t lapl_id = va_arg (arguments, hid_t);
 
                 /* Retrieve the object's comment */
-                if((ret = H5G_loc_get_comment(&loc, name, comment/*out*/, bufsize, lapl_id, H5AC_ind_dxpl_id)) < 0)
+                if((*ret = H5G_loc_get_comment(&loc, name, comment/*out*/, bufsize, lapl_id, H5AC_ind_dxpl_id)) < 0)
                     HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "object not found")
             }
-
-            memcpy (argv[0], &ret, sizeof(ssize_t));
             break;
         }
     default:
@@ -1216,10 +1277,11 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5VL_native_object_lookup(hid_t loc_id, H5VL_object_lookup_t lookup_type, void **location, int argc, void **argv)
+H5VL_native_object_lookup(hid_t loc_id, H5VL_object_lookup_t lookup_type, 
+                          int num_args, va_list arguments)
 {
     H5G_loc_t	loc;
-    H5G_loc_t   *obj_loc;        /* Location used to open group */
+    H5G_loc_t   *obj_loc, **location;        /* Location used to open group */
     hbool_t     loc_found = FALSE;      /* Entry at 'name' found */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
@@ -1228,6 +1290,8 @@ H5VL_native_object_lookup(hid_t loc_id, H5VL_object_lookup_t lookup_type, void *
     if(H5G_loc(loc_id, &loc) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
 
+    location = va_arg (arguments, H5G_loc_t **);
+
     if (NULL == (*location = (H5G_loc_t *)malloc(sizeof(H5G_loc_t))))
         HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "memory allocation failed for object location")
 
@@ -1241,8 +1305,8 @@ H5VL_native_object_lookup(hid_t loc_id, H5VL_object_lookup_t lookup_type, void *
     switch (lookup_type) {
     case H5O_LOOKUP_BY_NAME:
         {
-            char        *name = (char *)argv[0];
-            hid_t       lapl_id = *((hid_t *)argv[1]);
+            char        *name   = va_arg (arguments, char *);
+            hid_t       lapl_id = va_arg (arguments, hid_t);
 
             HDassert(&loc);
             HDassert(name && *name);
@@ -1255,11 +1319,11 @@ H5VL_native_object_lookup(hid_t loc_id, H5VL_object_lookup_t lookup_type, void *
         }
     case H5O_LOOKUP_BY_IDX:
         {
-            char *group_name = (char *)argv[0];
-            H5_index_t idx_type = *((H5_index_t *)argv[1]);
-            H5_iter_order_t order = *((H5_iter_order_t *)argv[2]);
-            hsize_t n = *((hsize_t *)argv[3]);
-            hid_t       lapl_id = *((hid_t *)argv[4]);
+            char            *group_name   = va_arg (arguments, char *);
+            H5_index_t      idx_type      = va_arg (arguments, H5_index_t);
+            H5_iter_order_t order         = va_arg (arguments, H5_iter_order_t);
+            hsize_t         n             = va_arg (arguments, hsize_t);
+            hid_t           lapl_id       = va_arg (arguments, hid_t);
 
             /* Find the object's location, according to the order in the index */
             if((ret_value = H5G_loc_find_by_idx(&loc, group_name, idx_type, order, n,
@@ -1270,7 +1334,7 @@ H5VL_native_object_lookup(hid_t loc_id, H5VL_object_lookup_t lookup_type, void *
         }
     case H5O_LOOKUP_BY_ADDR:
         {
-            haddr_t addr = *((haddr_t *)argv[0]);
+            haddr_t addr = va_arg (arguments, haddr_t);
 
             if(!H5F_addr_defined(addr))
                 HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no address supplied")
diff --git a/src/H5VLprivate.h b/src/H5VLprivate.h
index 867a05c..71d0e8b 100644
--- a/src/H5VLprivate.h
+++ b/src/H5VLprivate.h
@@ -53,7 +53,7 @@ H5_DLL hid_t  H5VL_file_open(const char *name, unsigned flags, hid_t fcpl_id,
 H5_DLL hid_t  H5VL_file_create(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id);
 H5_DLL herr_t H5VL_file_close(hid_t file_id);
 H5_DLL herr_t H5VL_file_flush(hid_t file_id, H5F_scope_t scope);
-H5_DLL herr_t H5VL_file_get(hid_t uid, H5VL_file_get_t get_type, void *data, int argc, void **argv);
+H5_DLL herr_t H5VL_file_get(hid_t uid, H5VL_file_get_t get_type, int num_args, ...);
 
 H5_DLL hid_t H5VL_dataset_create(hid_t uid, const char *name, hid_t dtype_id, hid_t space_id, hid_t lcpl_id, hid_t dcpl_id, hid_t dapl_id);
 H5_DLL hid_t H5VL_dataset_open(hid_t uid, const char *name, hid_t dapl_id);
@@ -67,12 +67,12 @@ H5_DLL hid_t H5VL_datatype_open(hid_t loc_id, const char *name, hid_t tapl_id);
 H5_DLL hid_t H5VL_group_create(hid_t uid, const char *name, hid_t lcpl_id, hid_t gcpl_id, hid_t gapl_id);
 H5_DLL hid_t H5VL_group_open(hid_t uid, const char *name, hid_t gapl_id);
 H5_DLL herr_t H5VL_group_close(hid_t uid);
-H5_DLL herr_t H5VL_group_get(hid_t uid, H5VL_group_get_t get_type, void *data, int argc, void **argv);
+H5_DLL herr_t H5VL_group_get(hid_t uid, H5VL_group_get_t get_type, int num_args, ...);
 
 H5_DLL hid_t H5VL_object_open(hid_t uid, void *obj_loc, hid_t lapl_id);
 H5_DLL herr_t H5VL_object_close(hid_t uid);
-H5_DLL herr_t H5VL_object_get(hid_t uid, H5VL_object_get_t get_type, void *data, int argc, void **argv);
-H5_DLL herr_t H5VL_object_lookup(hid_t uid, H5VL_object_lookup_t lookup_type, void **location, int argc, void **argv);
+H5_DLL herr_t H5VL_object_get(hid_t uid, H5VL_object_get_t get_type, int num_args, ...);
+H5_DLL herr_t H5VL_object_lookup(hid_t uid, H5VL_object_lookup_t lookup_type, int num_args, ...);
 
 H5_DLL herr_t H5VL_fapl_open(struct H5P_genplist_t *plist, hid_t vol_id, const void *vol_info);
 H5_DLL herr_t H5VL_fapl_copy(hid_t vol_id, const void *fapl, void **copied_fapl);
diff --git a/src/H5VLpublic.h b/src/H5VLpublic.h
index b374d78..06201cb 100644
--- a/src/H5VLpublic.h
+++ b/src/H5VLpublic.h
@@ -69,7 +69,7 @@ typedef struct H5VL_file_class_t {
     herr_t (*close) (hid_t file_id);
     hid_t  (*create)(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id);
     herr_t (*flush) (hid_t file_id, H5F_scope_t scope);
-    herr_t (*get)   (hid_t file_id, H5VL_file_get_t get_type, void *data, int argc, void **argv);
+    herr_t (*get)   (hid_t file_id, H5VL_file_get_t get_type, int num_args, va_list arguments);
 } H5VL_file_class_t;
 
 /* H5D routines */
@@ -120,7 +120,7 @@ typedef struct H5VL_group_class_t {
     hid_t  (*create)(hid_t loc_id, const char *name, hid_t lcpl_id, hid_t gcpl_id, hid_t gapl_id);
     hid_t  (*open)  (hid_t loc_id, const char *name, hid_t gapl_id);
     herr_t (*close) (hid_t group_id);
-    herr_t (*get)   (hid_t file_id, H5VL_group_get_t get_type, void *data, int argc, void **argv);
+    herr_t (*get)   (hid_t file_id, H5VL_group_get_t get_type, int num_args, va_list arguments);
 } H5VL_group_class_t;
 
 /* H5O routines */
@@ -131,8 +131,8 @@ typedef struct H5VL_object_class_t {
                      const char *dest_name, hid_t lcpl, hid_t lapl);
     herr_t (*copy)  (hid_t src_loc_id, const char *src_name, hid_t dst_loc_id, const char *dst_name,
                      hid_t ocpypl_id, hid_t lcpl_id );
-    herr_t (*lookup)(hid_t loc_id, H5VL_object_lookup_t lookup_type, void **location, int argc, void **argv);
-    herr_t (*get)   (hid_t loc_id, H5VL_object_get_t get_type, void *data, int argc, void **argv);
+    herr_t (*lookup)(hid_t loc_id, H5VL_object_lookup_t lookup_type, int num_args, va_list arguments);
+    herr_t (*get)   (hid_t loc_id, H5VL_object_get_t get_type, int num_args, va_list arguments);
 } H5VL_object_class_t;
 
 /* Class information for each VOL driver */