[Qemu-ppc] [PATCH v6 11/23] ppc: Improve use of qapi visitors

[Eric Blake]

The implementation of prop_get_fdt() is taking some shortcuts
with the qapi visitor functions.  Document them, and use
error_abort rather than NULL to ensure that any changes to
the visitors do not break our use of shortcuts.

Signed-off-by: Eric Blake <address@hidden>

---
v6: new patch, split from RFC on v5 7/46
---
 hw/ppc/spapr_drc.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
index 1846b4f..03a1879 100644
--- a/hw/ppc/spapr_drc.c
+++ b/hw/ppc/spapr_drc.c
@@ -276,21 +276,26 @@ static void prop_get_fdt(Object *obj, Visitor *v, void 
*opaque,
         case FDT_BEGIN_NODE:
             fdt_depth++;
             name = fdt_get_name(fdt, fdt_offset, &name_len);
-            visit_start_struct(v, NULL, NULL, name, 0, NULL);
+            visit_start_struct(v, NULL, "fdt", name, 0, &error_abort);
             break;
         case FDT_END_NODE:
             /* shouldn't ever see an FDT_END_NODE before FDT_BEGIN_NODE */
             g_assert(fdt_depth > 0);
-            visit_end_struct(v, NULL);
+            visit_end_struct(v, &error_abort);
             fdt_depth--;
             break;
         case FDT_PROP: {
             int i;
             prop = fdt_get_property_by_offset(fdt, fdt_offset, &prop_len);
             name = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
-            visit_start_list(v, name, NULL);
+            /* Note: since v is an output visitor, we can get away
+             * with just visiting a direct sequence of uint8 into the
+             * output array, instead of creating a uint8List and using
+             * visit_type_uint8List(). */
+            visit_start_list(v, name, &error_abort);
             for (i = 0; i < prop_len; i++) {
-                visit_type_uint8(v, (uint8_t *)&prop->data[i], NULL, NULL);
+                visit_type_uint8(v, (uint8_t *)&prop->data[i], NULL,
+                                 &error_abort);

             }
             visit_end_list(v);
-- 
2.4.3