2 * Commandline option parsing functions
4 * Copyright (c) 2003-2008 Fabrice Bellard
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26 #include "qemu/osdep.h"
28 #include "qapi/error.h"
29 #include "qemu-common.h"
30 #include "qemu/error-report.h"
31 #include "qapi/qmp/types.h"
32 #include "qapi/qmp/qerror.h"
33 #include "qemu/option_int.h"
34 #include "qemu/cutils.h"
36 #include "qemu/help_option.h"
39 * Extracts the name of an option from the parameter string (p points at the
40 * first byte of the option name)
42 * The option name is delimited by delim (usually , or =) or the string end
43 * and is copied into buf. If the option name is longer than buf_size, it is
44 * truncated. buf is always zero terminated.
46 * The return value is the position of the delimiter/zero byte after the option
49 const char *get_opt_name(char *buf, int buf_size, const char *p, char delim)
54 while (*p != '\0' && *p != delim) {
55 if (q && (q - buf) < buf_size - 1)
66 * Extracts the value of an option from the parameter string p (p points at the
67 * first byte of the option value)
69 * This function is comparable to get_opt_name with the difference that the
70 * delimiter is fixed to be comma which starts a new option. To specify an
71 * option value that contains commas, double each comma.
73 const char *get_opt_value(char *buf, int buf_size, const char *p)
84 if (q && (q - buf) < buf_size - 1)
94 int get_next_param_value(char *buf, int buf_size,
95 const char *tag, const char **pstr)
102 p = get_opt_name(option, sizeof(option), p, '=');
106 if (!strcmp(tag, option)) {
107 *pstr = get_opt_value(buf, buf_size, p);
113 p = get_opt_value(NULL, 0, p);
122 int get_param_value(char *buf, int buf_size,
123 const char *tag, const char *str)
125 return get_next_param_value(buf, buf_size, tag, &str);
128 static void parse_option_bool(const char *name, const char *value, bool *ret,
132 if (!strcmp(value, "on")) {
134 } else if (!strcmp(value, "off")) {
137 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
138 name, "'on' or 'off'");
145 static void parse_option_number(const char *name, const char *value,
146 uint64_t *ret, Error **errp)
152 number = strtoull(value, &postfix, 0);
153 if (*postfix != '\0') {
154 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a number");
159 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a number");
163 static const QemuOptDesc *find_desc_by_name(const QemuOptDesc *desc,
168 for (i = 0; desc[i].name != NULL; i++) {
169 if (strcmp(desc[i].name, name) == 0) {
177 void parse_option_size(const char *name, const char *value,
178 uint64_t *ret, Error **errp)
184 sizef = strtod(value, &postfix);
185 if (sizef < 0 || sizef > UINT64_MAX) {
186 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name,
187 "a non-negative number below 2^64");
206 *ret = (uint64_t) sizef;
209 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a size");
210 error_append_hint(errp, "You may use k, M, G or T suffixes for "
211 "kilobytes, megabytes, gigabytes and terabytes.\n");
215 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a size");
219 bool has_help_option(const char *param)
221 size_t buflen = strlen(param) + 1;
222 char *buf = g_malloc(buflen);
223 const char *p = param;
227 p = get_opt_value(buf, buflen, p);
232 if (is_help_option(buf)) {
243 bool is_valid_option_list(const char *param)
245 size_t buflen = strlen(param) + 1;
246 char *buf = g_malloc(buflen);
247 const char *p = param;
251 p = get_opt_value(buf, buflen, p);
257 if (!*buf || *buf == ',') {
268 void qemu_opts_print_help(QemuOptsList *list)
274 printf("Supported options:\n");
275 while (desc && desc->name) {
276 printf("%-16s %s\n", desc->name,
277 desc->help ? desc->help : "No description available");
281 /* ------------------------------------------------------------------ */
283 QemuOpt *qemu_opt_find(QemuOpts *opts, const char *name)
287 QTAILQ_FOREACH_REVERSE(opt, &opts->head, QemuOptHead, next) {
288 if (strcmp(opt->name, name) != 0)
295 static void qemu_opt_del(QemuOpt *opt)
297 QTAILQ_REMOVE(&opt->opts->head, opt, next);
303 /* qemu_opt_set allows many settings for the same option.
304 * This function deletes all settings for an option.
306 static void qemu_opt_del_all(QemuOpts *opts, const char *name)
308 QemuOpt *opt, *next_opt;
310 QTAILQ_FOREACH_SAFE(opt, &opts->head, next, next_opt) {
311 if (!strcmp(opt->name, name)) {
317 const char *qemu_opt_get(QemuOpts *opts, const char *name)
325 opt = qemu_opt_find(opts, name);
327 const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
328 if (desc && desc->def_value_str) {
329 return desc->def_value_str;
332 return opt ? opt->str : NULL;
335 /* Get a known option (or its default) and remove it from the list
336 * all in one action. Return a malloced string of the option value.
337 * Result must be freed by caller with g_free().
339 char *qemu_opt_get_del(QemuOpts *opts, const char *name)
342 const QemuOptDesc *desc;
349 opt = qemu_opt_find(opts, name);
351 desc = find_desc_by_name(opts->list->desc, name);
352 if (desc && desc->def_value_str) {
353 str = g_strdup(desc->def_value_str);
359 qemu_opt_del_all(opts, name);
363 bool qemu_opt_has_help_opt(QemuOpts *opts)
367 QTAILQ_FOREACH_REVERSE(opt, &opts->head, QemuOptHead, next) {
368 if (is_help_option(opt->name)) {
375 static bool qemu_opt_get_bool_helper(QemuOpts *opts, const char *name,
376 bool defval, bool del)
385 opt = qemu_opt_find(opts, name);
387 const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
388 if (desc && desc->def_value_str) {
389 parse_option_bool(name, desc->def_value_str, &ret, &error_abort);
393 assert(opt->desc && opt->desc->type == QEMU_OPT_BOOL);
394 ret = opt->value.boolean;
396 qemu_opt_del_all(opts, name);
401 bool qemu_opt_get_bool(QemuOpts *opts, const char *name, bool defval)
403 return qemu_opt_get_bool_helper(opts, name, defval, false);
406 bool qemu_opt_get_bool_del(QemuOpts *opts, const char *name, bool defval)
408 return qemu_opt_get_bool_helper(opts, name, defval, true);
411 static uint64_t qemu_opt_get_number_helper(QemuOpts *opts, const char *name,
412 uint64_t defval, bool del)
415 uint64_t ret = defval;
421 opt = qemu_opt_find(opts, name);
423 const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
424 if (desc && desc->def_value_str) {
425 parse_option_number(name, desc->def_value_str, &ret, &error_abort);
429 assert(opt->desc && opt->desc->type == QEMU_OPT_NUMBER);
430 ret = opt->value.uint;
432 qemu_opt_del_all(opts, name);
437 uint64_t qemu_opt_get_number(QemuOpts *opts, const char *name, uint64_t defval)
439 return qemu_opt_get_number_helper(opts, name, defval, false);
442 uint64_t qemu_opt_get_number_del(QemuOpts *opts, const char *name,
445 return qemu_opt_get_number_helper(opts, name, defval, true);
448 static uint64_t qemu_opt_get_size_helper(QemuOpts *opts, const char *name,
449 uint64_t defval, bool del)
452 uint64_t ret = defval;
458 opt = qemu_opt_find(opts, name);
460 const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
461 if (desc && desc->def_value_str) {
462 parse_option_size(name, desc->def_value_str, &ret, &error_abort);
466 assert(opt->desc && opt->desc->type == QEMU_OPT_SIZE);
467 ret = opt->value.uint;
469 qemu_opt_del_all(opts, name);
474 uint64_t qemu_opt_get_size(QemuOpts *opts, const char *name, uint64_t defval)
476 return qemu_opt_get_size_helper(opts, name, defval, false);
479 uint64_t qemu_opt_get_size_del(QemuOpts *opts, const char *name,
482 return qemu_opt_get_size_helper(opts, name, defval, true);
485 static void qemu_opt_parse(QemuOpt *opt, Error **errp)
487 if (opt->desc == NULL)
490 switch (opt->desc->type) {
491 case QEMU_OPT_STRING:
495 parse_option_bool(opt->name, opt->str, &opt->value.boolean, errp);
497 case QEMU_OPT_NUMBER:
498 parse_option_number(opt->name, opt->str, &opt->value.uint, errp);
501 parse_option_size(opt->name, opt->str, &opt->value.uint, errp);
508 static bool opts_accepts_any(const QemuOpts *opts)
510 return opts->list->desc[0].name == NULL;
513 int qemu_opt_unset(QemuOpts *opts, const char *name)
515 QemuOpt *opt = qemu_opt_find(opts, name);
517 assert(opts_accepts_any(opts));
527 static void opt_set(QemuOpts *opts, const char *name, const char *value,
528 bool prepend, Error **errp)
531 const QemuOptDesc *desc;
532 Error *local_err = NULL;
534 desc = find_desc_by_name(opts->list->desc, name);
535 if (!desc && !opts_accepts_any(opts)) {
536 error_setg(errp, QERR_INVALID_PARAMETER, name);
540 opt = g_malloc0(sizeof(*opt));
541 opt->name = g_strdup(name);
544 QTAILQ_INSERT_HEAD(&opts->head, opt, next);
546 QTAILQ_INSERT_TAIL(&opts->head, opt, next);
549 opt->str = g_strdup(value);
550 qemu_opt_parse(opt, &local_err);
552 error_propagate(errp, local_err);
557 void qemu_opt_set(QemuOpts *opts, const char *name, const char *value,
560 opt_set(opts, name, value, false, errp);
563 void qemu_opt_set_bool(QemuOpts *opts, const char *name, bool val,
567 const QemuOptDesc *desc = opts->list->desc;
569 opt = g_malloc0(sizeof(*opt));
570 opt->desc = find_desc_by_name(desc, name);
571 if (!opt->desc && !opts_accepts_any(opts)) {
572 error_setg(errp, QERR_INVALID_PARAMETER, name);
577 opt->name = g_strdup(name);
579 opt->value.boolean = !!val;
580 opt->str = g_strdup(val ? "on" : "off");
581 QTAILQ_INSERT_TAIL(&opts->head, opt, next);
584 void qemu_opt_set_number(QemuOpts *opts, const char *name, int64_t val,
588 const QemuOptDesc *desc = opts->list->desc;
590 opt = g_malloc0(sizeof(*opt));
591 opt->desc = find_desc_by_name(desc, name);
592 if (!opt->desc && !opts_accepts_any(opts)) {
593 error_setg(errp, QERR_INVALID_PARAMETER, name);
598 opt->name = g_strdup(name);
600 opt->value.uint = val;
601 opt->str = g_strdup_printf("%" PRId64, val);
602 QTAILQ_INSERT_TAIL(&opts->head, opt, next);
606 * For each member of @opts, call @func(@opaque, name, value, @errp).
607 * @func() may store an Error through @errp, but must return non-zero then.
608 * When @func() returns non-zero, break the loop and return that value.
609 * Return zero when the loop completes.
611 int qemu_opt_foreach(QemuOpts *opts, qemu_opt_loopfunc func, void *opaque,
617 QTAILQ_FOREACH(opt, &opts->head, next) {
618 rc = func(opaque, opt->name, opt->str, errp);
622 assert(!errp || !*errp);
627 QemuOpts *qemu_opts_find(QemuOptsList *list, const char *id)
631 QTAILQ_FOREACH(opts, &list->head, next) {
632 if (!opts->id && !id) {
635 if (opts->id && id && !strcmp(opts->id, id)) {
642 QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id,
643 int fail_if_exists, Error **errp)
645 QemuOpts *opts = NULL;
648 if (!id_wellformed(id)) {
649 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id",
651 error_append_hint(errp, "Identifiers consist of letters, digits, "
652 "'-', '.', '_', starting with a letter.\n");
655 opts = qemu_opts_find(list, id);
657 if (fail_if_exists && !list->merge_lists) {
658 error_setg(errp, "Duplicate ID '%s' for %s", id, list->name);
664 } else if (list->merge_lists) {
665 opts = qemu_opts_find(list, NULL);
670 opts = g_malloc0(sizeof(*opts));
671 opts->id = g_strdup(id);
673 loc_save(&opts->loc);
674 QTAILQ_INIT(&opts->head);
675 QTAILQ_INSERT_TAIL(&list->head, opts, next);
679 void qemu_opts_reset(QemuOptsList *list)
681 QemuOpts *opts, *next_opts;
683 QTAILQ_FOREACH_SAFE(opts, &list->head, next, next_opts) {
688 void qemu_opts_loc_restore(QemuOpts *opts)
690 loc_restore(&opts->loc);
693 void qemu_opts_set(QemuOptsList *list, const char *id,
694 const char *name, const char *value, Error **errp)
697 Error *local_err = NULL;
699 opts = qemu_opts_create(list, id, 1, &local_err);
701 error_propagate(errp, local_err);
704 qemu_opt_set(opts, name, value, errp);
707 const char *qemu_opts_id(QemuOpts *opts)
712 /* The id string will be g_free()d by qemu_opts_del */
713 void qemu_opts_set_id(QemuOpts *opts, char *id)
718 void qemu_opts_del(QemuOpts *opts)
727 opt = QTAILQ_FIRST(&opts->head);
732 QTAILQ_REMOVE(&opts->list->head, opts, next);
737 /* print value, escaping any commas in value */
738 static void escaped_print(const char *value)
742 for (ptr = value; *ptr; ++ptr) {
750 void qemu_opts_print(QemuOpts *opts, const char *separator)
753 QemuOptDesc *desc = opts->list->desc;
754 const char *sep = "";
757 printf("id=%s", opts->id); /* passed id_wellformed -> no commas */
761 if (desc[0].name == NULL) {
762 QTAILQ_FOREACH(opt, &opts->head, next) {
763 printf("%s%s=", sep, opt->name);
764 escaped_print(opt->str);
769 for (; desc && desc->name; desc++) {
771 QemuOpt *opt = qemu_opt_find(opts, desc->name);
773 value = opt ? opt->str : desc->def_value_str;
777 if (desc->type == QEMU_OPT_STRING) {
778 printf("%s%s=", sep, desc->name);
779 escaped_print(value);
780 } else if ((desc->type == QEMU_OPT_SIZE ||
781 desc->type == QEMU_OPT_NUMBER) && opt) {
782 printf("%s%s=%" PRId64, sep, desc->name, opt->value.uint);
784 printf("%s%s=%s", sep, desc->name, value);
790 static void opts_do_parse(QemuOpts *opts, const char *params,
791 const char *firstname, bool prepend, Error **errp)
793 char option[128], value[1024];
794 const char *p,*pe,*pc;
795 Error *local_err = NULL;
797 for (p = params; *p != '\0'; p++) {
800 if (!pe || (pc && pc < pe)) {
801 /* found "foo,more" */
802 if (p == params && firstname) {
803 /* implicitly named first option */
804 pstrcpy(option, sizeof(option), firstname);
805 p = get_opt_value(value, sizeof(value), p);
807 /* option without value, probably a flag */
808 p = get_opt_name(option, sizeof(option), p, ',');
809 if (strncmp(option, "no", 2) == 0) {
810 memmove(option, option+2, strlen(option+2)+1);
811 pstrcpy(value, sizeof(value), "off");
813 pstrcpy(value, sizeof(value), "on");
817 /* found "foo=bar,more" */
818 p = get_opt_name(option, sizeof(option), p, '=');
823 p = get_opt_value(value, sizeof(value), p);
825 if (strcmp(option, "id") != 0) {
826 /* store and parse */
827 opt_set(opts, option, value, prepend, &local_err);
829 error_propagate(errp, local_err);
840 * Store options parsed from @params into @opts.
841 * If @firstname is non-null, the first key=value in @params may omit
842 * key=, and is treated as if key was @firstname.
843 * On error, store an error object through @errp if non-null.
845 void qemu_opts_do_parse(QemuOpts *opts, const char *params,
846 const char *firstname, Error **errp)
848 opts_do_parse(opts, params, firstname, false, errp);
851 static QemuOpts *opts_parse(QemuOptsList *list, const char *params,
852 bool permit_abbrev, bool defaults, Error **errp)
854 const char *firstname;
855 char value[1024], *id = NULL;
858 Error *local_err = NULL;
860 assert(!permit_abbrev || list->implied_opt_name);
861 firstname = permit_abbrev ? list->implied_opt_name : NULL;
863 if (strncmp(params, "id=", 3) == 0) {
864 get_opt_value(value, sizeof(value), params+3);
866 } else if ((p = strstr(params, ",id=")) != NULL) {
867 get_opt_value(value, sizeof(value), p+4);
872 * This code doesn't work for defaults && !list->merge_lists: when
873 * params has no id=, and list has an element with !opts->id, it
874 * appends a new element instead of returning the existing opts.
875 * However, we got no use for this case. Guard against possible
876 * (if unlikely) future misuse:
878 assert(!defaults || list->merge_lists);
879 opts = qemu_opts_create(list, id, !defaults, &local_err);
881 error_propagate(errp, local_err);
885 opts_do_parse(opts, params, firstname, defaults, &local_err);
887 error_propagate(errp, local_err);
896 * Create a QemuOpts in @list and with options parsed from @params.
897 * If @permit_abbrev, the first key=value in @params may omit key=,
898 * and is treated as if key was @list->implied_opt_name.
899 * On error, store an error object through @errp if non-null.
900 * Return the new QemuOpts on success, null pointer on error.
902 QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params,
903 bool permit_abbrev, Error **errp)
905 return opts_parse(list, params, permit_abbrev, false, errp);
909 * Create a QemuOpts in @list and with options parsed from @params.
910 * If @permit_abbrev, the first key=value in @params may omit key=,
911 * and is treated as if key was @list->implied_opt_name.
912 * Report errors with error_report_err(). This is inappropriate in
913 * QMP context. Do not use this function there!
914 * Return the new QemuOpts on success, null pointer on error.
916 QemuOpts *qemu_opts_parse_noisily(QemuOptsList *list, const char *params,
922 opts = opts_parse(list, params, permit_abbrev, false, &err);
924 error_report_err(err);
929 void qemu_opts_set_defaults(QemuOptsList *list, const char *params,
934 opts = opts_parse(list, params, permit_abbrev, true, NULL);
938 typedef struct OptsFromQDictState {
941 } OptsFromQDictState;
943 static void qemu_opts_from_qdict_1(const char *key, QObject *obj, void *opaque)
945 OptsFromQDictState *state = opaque;
950 if (!strcmp(key, "id") || *state->errp) {
954 switch (qobject_type(obj)) {
956 value = qstring_get_str(qobject_to_qstring(obj));
959 n = snprintf(buf, sizeof(buf), "%" PRId64,
960 qint_get_int(qobject_to_qint(obj)));
961 assert(n < sizeof(buf));
965 n = snprintf(buf, sizeof(buf), "%.17g",
966 qfloat_get_double(qobject_to_qfloat(obj)));
967 assert(n < sizeof(buf));
971 pstrcpy(buf, sizeof(buf),
972 qbool_get_bool(qobject_to_qbool(obj)) ? "on" : "off");
979 qemu_opt_set(state->opts, key, value, state->errp);
983 * Create QemuOpts from a QDict.
984 * Use value of key "id" as ID if it exists and is a QString.
985 * Only QStrings, QInts, QFloats and QBools are copied. Entries with
986 * other types are silently ignored.
988 QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict,
991 OptsFromQDictState state;
992 Error *local_err = NULL;
995 opts = qemu_opts_create(list, qdict_get_try_str(qdict, "id"), 1,
998 error_propagate(errp, local_err);
1002 assert(opts != NULL);
1004 state.errp = &local_err;
1006 qdict_iter(qdict, qemu_opts_from_qdict_1, &state);
1008 error_propagate(errp, local_err);
1009 qemu_opts_del(opts);
1017 * Adds all QDict entries to the QemuOpts that can be added and removes them
1018 * from the QDict. When this function returns, the QDict contains only those
1019 * entries that couldn't be added to the QemuOpts.
1021 void qemu_opts_absorb_qdict(QemuOpts *opts, QDict *qdict, Error **errp)
1023 const QDictEntry *entry, *next;
1025 entry = qdict_first(qdict);
1027 while (entry != NULL) {
1028 Error *local_err = NULL;
1029 OptsFromQDictState state = {
1034 next = qdict_next(qdict, entry);
1036 if (find_desc_by_name(opts->list->desc, entry->key)) {
1037 qemu_opts_from_qdict_1(entry->key, entry->value, &state);
1039 error_propagate(errp, local_err);
1042 qdict_del(qdict, entry->key);
1051 * Convert from QemuOpts to QDict.
1052 * The QDict values are of type QString.
1053 * TODO We'll want to use types appropriate for opt->desc->type, but
1054 * this is enough for now.
1056 QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict)
1062 qdict = qdict_new();
1065 qdict_put(qdict, "id", qstring_from_str(opts->id));
1067 QTAILQ_FOREACH(opt, &opts->head, next) {
1068 val = QOBJECT(qstring_from_str(opt->str));
1069 qdict_put_obj(qdict, opt->name, val);
1074 /* Validate parsed opts against descriptions where no
1075 * descriptions were provided in the QemuOptsList.
1077 void qemu_opts_validate(QemuOpts *opts, const QemuOptDesc *desc, Error **errp)
1080 Error *local_err = NULL;
1082 assert(opts_accepts_any(opts));
1084 QTAILQ_FOREACH(opt, &opts->head, next) {
1085 opt->desc = find_desc_by_name(desc, opt->name);
1087 error_setg(errp, QERR_INVALID_PARAMETER, opt->name);
1091 qemu_opt_parse(opt, &local_err);
1093 error_propagate(errp, local_err);
1100 * For each member of @list, call @func(@opaque, member, @errp).
1101 * Call it with the current location temporarily set to the member's.
1102 * @func() may store an Error through @errp, but must return non-zero then.
1103 * When @func() returns non-zero, break the loop and return that value.
1104 * Return zero when the loop completes.
1106 int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func,
1107 void *opaque, Error **errp)
1113 loc_push_none(&loc);
1114 QTAILQ_FOREACH(opts, &list->head, next) {
1115 loc_restore(&opts->loc);
1116 rc = func(opaque, opts, errp);
1120 assert(!errp || !*errp);
1126 static size_t count_opts_list(QemuOptsList *list)
1128 QemuOptDesc *desc = NULL;
1129 size_t num_opts = 0;
1136 while (desc && desc->name) {
1144 void qemu_opts_free(QemuOptsList *list)
1149 /* Realloc dst option list and append options from an option list (list)
1150 * to it. dst could be NULL or a malloced list.
1151 * The lifetime of dst must be shorter than the input list because the
1152 * QemuOptDesc->name, ->help, and ->def_value_str strings are shared.
1154 QemuOptsList *qemu_opts_append(QemuOptsList *dst,
1157 size_t num_opts, num_dst_opts;
1159 bool need_init = false;
1160 bool need_head_update;
1166 /* If dst is NULL, after realloc, some area of dst should be initialized
1167 * before adding options to it.
1171 need_head_update = true;
1173 /* Moreover, even if dst is not NULL, the realloc may move it to a
1174 * different address in which case we may get a stale tail pointer
1176 need_head_update = QTAILQ_EMPTY(&dst->head);
1179 num_opts = count_opts_list(dst);
1180 num_dst_opts = num_opts;
1181 num_opts += count_opts_list(list);
1182 dst = g_realloc(dst, sizeof(QemuOptsList) +
1183 (num_opts + 1) * sizeof(QemuOptDesc));
1186 dst->implied_opt_name = NULL;
1187 dst->merge_lists = false;
1189 if (need_head_update) {
1190 QTAILQ_INIT(&dst->head);
1192 dst->desc[num_dst_opts].name = NULL;
1194 /* append list->desc to dst->desc */
1197 while (desc && desc->name) {
1198 if (find_desc_by_name(dst->desc, desc->name) == NULL) {
1199 dst->desc[num_dst_opts++] = *desc;
1200 dst->desc[num_dst_opts].name = NULL;