+
+static size_t count_opts_list(QemuOptsList *list)
+{
+ QemuOptDesc *desc = NULL;
+ size_t num_opts = 0;
+
+ if (!list) {
+ return 0;
+ }
+
+ desc = list->desc;
+ while (desc && desc->name) {
+ num_opts++;
+ desc++;
+ }
+
+ return num_opts;
+}
+
+void qemu_opts_free(QemuOptsList *list)
+{
+ g_free(list);
+}
+
+/* Realloc dst option list and append options from an option list (list)
+ * to it. dst could be NULL or a malloced list.
+ * The lifetime of dst must be shorter than the input list because the
+ * QemuOptDesc->name, ->help, and ->def_value_str strings are shared.
+ */
+QemuOptsList *qemu_opts_append(QemuOptsList *dst,
+ QemuOptsList *list)
+{
+ size_t num_opts, num_dst_opts;
+ QemuOptDesc *desc;
+ bool need_init = false;
+ bool need_head_update;
+
+ if (!list) {
+ return dst;
+ }
+
+ /* If dst is NULL, after realloc, some area of dst should be initialized
+ * before adding options to it.
+ */
+ if (!dst) {
+ need_init = true;
+ need_head_update = true;
+ } else {
+ /* Moreover, even if dst is not NULL, the realloc may move it to a
+ * different address in which case we may get a stale tail pointer
+ * in dst->head. */
+ need_head_update = QTAILQ_EMPTY(&dst->head);
+ }
+
+ num_opts = count_opts_list(dst);
+ num_dst_opts = num_opts;
+ num_opts += count_opts_list(list);
+ dst = g_realloc(dst, sizeof(QemuOptsList) +
+ (num_opts + 1) * sizeof(QemuOptDesc));
+ if (need_init) {
+ dst->name = NULL;
+ dst->implied_opt_name = NULL;
+ dst->merge_lists = false;
+ }
+ if (need_head_update) {
+ QTAILQ_INIT(&dst->head);
+ }
+ dst->desc[num_dst_opts].name = NULL;
+
+ /* append list->desc to dst->desc */
+ if (list) {
+ desc = list->desc;
+ while (desc && desc->name) {
+ if (find_desc_by_name(dst->desc, desc->name) == NULL) {
+ dst->desc[num_dst_opts++] = *desc;
+ dst->desc[num_dst_opts].name = NULL;
+ }
+ desc++;
+ }
+ }
+
+ return dst;
+}