qemu-e2k/include/qemu/option.h
Kevin Wolf 8bf12c4f75 keyval: Parse help options
This adds a special meaning for 'help' and '?' as options to the keyval
parser. Instead of being an error (because of a missing value) or a
value for an implied key, they now request help, which is a new boolean
output of the parser in addition to the QDict.

A new parameter 'p_help' is added to keyval_parse() that contains on
return whether help was requested. If NULL is passed, requesting help
results in an error and all other cases work like before.

Turning previous error cases into help is a compatible extension. The
behaviour potentially changes for implied keys: They could previously
get 'help' as their value, which is now interpreted as requesting help.

This is not a problem in practice because 'help' and '?' are not a valid
values for the implied key of any option parsed with keyval_parse():

* audiodev: union Audiodev, implied key "driver" is enum AudiodevDriver,
  "help" and "?" are not among its values

* display: union DisplayOptions, implied key "type" is enum
  DisplayType, "help" and "?" are not among its values

* blockdev: union BlockdevOptions, implied key "driver is enum
  BlockdevDriver, "help" and "?" are not among its values

* export: union BlockExport, implied key "type" is enum BlockExportType,
  "help" and "?" are not among its values

* monitor: struct MonitorOptions, implied key "mode" is enum MonitorMode,
  "help" and "?" are not among its values

* nbd-server: struct NbdServerOptions, no implied key.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201011073505.1185335-5-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-15 16:06:27 +02:00

155 lines
6.5 KiB
C

/*
* Commandline option parsing functions
*
* Copyright (c) 2003-2008 Fabrice Bellard
* Copyright (c) 2009 Kevin Wolf <kwolf@redhat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef QEMU_OPTION_H
#define QEMU_OPTION_H
#include "qemu/queue.h"
/**
* get_opt_value
* @p: a pointer to the option name, delimited by commas
* @value: a non-NULL pointer that will received the delimited options
*
* The @value char pointer will be allocated and filled with
* the delimited options.
*
* Returns the position of the comma delimiter/zero byte after the
* option name in @p.
* The memory pointer in @value must be released with a call to g_free()
* when no longer required.
*/
const char *get_opt_value(const char *p, char **value);
bool parse_option_size(const char *name, const char *value,
uint64_t *ret, Error **errp);
bool has_help_option(const char *param);
enum QemuOptType {
QEMU_OPT_STRING = 0, /* no parsing (use string as-is) */
QEMU_OPT_BOOL, /* on/off */
QEMU_OPT_NUMBER, /* simple number */
QEMU_OPT_SIZE, /* size, accepts (K)ilo, (M)ega, (G)iga, (T)era postfix */
};
typedef struct QemuOptDesc {
const char *name;
enum QemuOptType type;
const char *help;
const char *def_value_str;
} QemuOptDesc;
struct QemuOptsList {
const char *name;
const char *implied_opt_name;
bool merge_lists; /* Merge multiple uses of option into a single list? */
QTAILQ_HEAD(, QemuOpts) head;
QemuOptDesc desc[];
};
const char *qemu_opt_get(QemuOpts *opts, const char *name);
char *qemu_opt_get_del(QemuOpts *opts, const char *name);
/**
* qemu_opt_has_help_opt:
* @opts: options to search for a help request
*
* Check whether the options specified by @opts include one of the
* standard strings which indicate that the user is asking for a
* list of the valid values for a command line option (as defined
* by is_help_option()).
*
* Returns: true if @opts includes 'help' or equivalent.
*/
bool qemu_opt_has_help_opt(QemuOpts *opts);
QemuOpt *qemu_opt_find(QemuOpts *opts, const char *name);
bool qemu_opt_get_bool(QemuOpts *opts, const char *name, bool defval);
uint64_t qemu_opt_get_number(QemuOpts *opts, const char *name, uint64_t defval);
uint64_t qemu_opt_get_size(QemuOpts *opts, const char *name, uint64_t defval);
bool qemu_opt_get_bool_del(QemuOpts *opts, const char *name, bool defval);
uint64_t qemu_opt_get_number_del(QemuOpts *opts, const char *name,
uint64_t defval);
uint64_t qemu_opt_get_size_del(QemuOpts *opts, const char *name,
uint64_t defval);
int qemu_opt_unset(QemuOpts *opts, const char *name);
bool qemu_opt_set(QemuOpts *opts, const char *name, const char *value,
Error **errp);
bool qemu_opt_set_bool(QemuOpts *opts, const char *name, bool val,
Error **errp);
bool qemu_opt_set_number(QemuOpts *opts, const char *name, int64_t val,
Error **errp);
typedef int (*qemu_opt_loopfunc)(void *opaque,
const char *name, const char *value,
Error **errp);
int qemu_opt_foreach(QemuOpts *opts, qemu_opt_loopfunc func, void *opaque,
Error **errp);
typedef struct {
QemuOpts *opts;
QemuOpt *opt;
const char *name;
} QemuOptsIter;
void qemu_opt_iter_init(QemuOptsIter *iter, QemuOpts *opts, const char *name);
const char *qemu_opt_iter_next(QemuOptsIter *iter);
QemuOpts *qemu_opts_find(QemuOptsList *list, const char *id);
QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id,
int fail_if_exists, Error **errp);
void qemu_opts_reset(QemuOptsList *list);
void qemu_opts_loc_restore(QemuOpts *opts);
bool qemu_opts_set(QemuOptsList *list, const char *id,
const char *name, const char *value, Error **errp);
const char *qemu_opts_id(QemuOpts *opts);
void qemu_opts_set_id(QemuOpts *opts, char *id);
void qemu_opts_del(QemuOpts *opts);
bool qemu_opts_validate(QemuOpts *opts, const QemuOptDesc *desc, Error **errp);
bool qemu_opts_do_parse(QemuOpts *opts, const char *params,
const char *firstname, Error **errp);
QemuOpts *qemu_opts_parse_noisily(QemuOptsList *list, const char *params,
bool permit_abbrev);
QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params,
bool permit_abbrev, Error **errp);
void qemu_opts_set_defaults(QemuOptsList *list, const char *params,
int permit_abbrev);
QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict,
Error **errp);
QDict *qemu_opts_to_qdict_filtered(QemuOpts *opts, QDict *qdict,
QemuOptsList *list, bool del);
QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict);
bool qemu_opts_absorb_qdict(QemuOpts *opts, QDict *qdict, Error **errp);
typedef int (*qemu_opts_loopfunc)(void *opaque, QemuOpts *opts, Error **errp);
int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func,
void *opaque, Error **errp);
void qemu_opts_print(QemuOpts *opts, const char *sep);
void qemu_opts_print_help(QemuOptsList *list, bool print_caption);
void qemu_opts_free(QemuOptsList *list);
QemuOptsList *qemu_opts_append(QemuOptsList *dst, QemuOptsList *list);
QDict *keyval_parse(const char *params, const char *implied_key,
bool *help, Error **errp);
#endif