mpv/core/m_config.c

792 lines
26 KiB
C

/*
* This file is part of MPlayer.
*
* MPlayer is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* MPlayer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/// \file
/// \ingroup Config
#include "config.h"
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <assert.h>
#include <stdbool.h>
#include "talloc.h"
#include "m_config.h"
#include "core/m_option.h"
#include "core/mp_msg.h"
// Profiles allow to predefine some sets of options that can then
// be applied later on with the internal -profile option.
#define MAX_PROFILE_DEPTH 20
struct m_profile {
struct m_profile *next;
char *name;
char *desc;
int num_opts;
// Option/value pair array.
char **opts;
};
// In the file local case, this contains the old global value.
struct m_opt_backup {
struct m_opt_backup *next;
struct m_config_option *co;
void *backup;
};
static int parse_include(struct m_config *config, struct bstr param, bool set)
{
if (param.len == 0)
return M_OPT_MISSING_PARAM;
if (!set)
return 1;
char *filename = bstrdup0(NULL, param);
config->includefunc(config, filename);
talloc_free(filename);
return 1;
}
static int parse_profile(struct m_config *config, const struct m_option *opt,
struct bstr name, struct bstr param, bool set)
{
if (!bstrcmp0(param, "help")) {
struct m_profile *p;
if (!config->profiles) {
mp_tmsg(MSGT_CFGPARSER, MSGL_INFO,
"No profiles have been defined.\n");
return M_OPT_EXIT - 1;
}
mp_tmsg(MSGT_CFGPARSER, MSGL_INFO, "Available profiles:\n");
for (p = config->profiles; p; p = p->next)
mp_msg(MSGT_CFGPARSER, MSGL_INFO, "\t%s\t%s\n", p->name,
p->desc ? p->desc : "");
mp_msg(MSGT_CFGPARSER, MSGL_INFO, "\n");
return M_OPT_EXIT - 1;
}
char **list = NULL;
int r = m_option_type_string_list.parse(opt, name, param, &list);
if (r < 0)
return r;
if (!list || !list[0])
return M_OPT_INVALID;
for (int i = 0; list[i]; i++) {
struct m_profile *p = m_config_get_profile0(config, list[i]);
if (!p) {
mp_tmsg(MSGT_CFGPARSER, MSGL_WARN, "Unknown profile '%s'.\n",
list[i]);
r = M_OPT_INVALID;
} else if (set)
m_config_set_profile(config, p);
}
m_option_free(opt, &list);
return r;
}
static int show_profile(struct m_config *config, bstr param)
{
struct m_profile *p;
int i, j;
if (!param.len)
return M_OPT_MISSING_PARAM;
if (!(p = m_config_get_profile(config, param))) {
mp_tmsg(MSGT_CFGPARSER, MSGL_ERR, "Unknown profile '%.*s'.\n",
BSTR_P(param));
return M_OPT_EXIT - 1;
}
if (!config->profile_depth)
mp_tmsg(MSGT_CFGPARSER, MSGL_INFO, "Profile %s: %s\n", p->name,
p->desc ? p->desc : "");
config->profile_depth++;
for (i = 0; i < p->num_opts; i++) {
char spc[config->profile_depth + 1];
for (j = 0; j < config->profile_depth; j++)
spc[j] = ' ';
spc[config->profile_depth] = '\0';
mp_msg(MSGT_CFGPARSER, MSGL_INFO, "%s%s=%s\n", spc,
p->opts[2 * i], p->opts[2 * i + 1]);
if (config->profile_depth < MAX_PROFILE_DEPTH
&& !strcmp(p->opts[2*i], "profile")) {
char *e, *list = p->opts[2 * i + 1];
while ((e = strchr(list, ','))) {
int l = e - list;
char tmp[l+1];
if (!l)
continue;
memcpy(tmp, list, l);
tmp[l] = '\0';
show_profile(config, bstr0(tmp));
list = e + 1;
}
if (list[0] != '\0')
show_profile(config, bstr0(list));
}
}
config->profile_depth--;
if (!config->profile_depth)
mp_msg(MSGT_CFGPARSER, MSGL_INFO, "\n");
return M_OPT_EXIT - 1;
}
static int list_options(struct m_config *config)
{
m_config_print_option_list(config);
return M_OPT_EXIT;
}
// The memcpys are supposed to work around the struct aliasing violation,
// that would result if we just dereferenced a void** (where the void** is
// actually casted from struct some_type* ).
static void *substruct_read_ptr(void *ptr)
{
void *res;
memcpy(&res, ptr, sizeof(void*));
return res;
}
static void substruct_write_ptr(void *ptr, void *val)
{
memcpy(ptr, &val, sizeof(void*));
}
static struct m_config_option *m_config_add_option(struct m_config *config,
const char *prefix,
struct m_config_option *parent,
const struct m_option *arg);
static void add_options(struct m_config *config,
struct m_config_option *parent,
const struct m_option *defs);
static int config_destroy(void *p)
{
struct m_config *config = p;
if (config->file_local_mode)
m_config_leave_file_local(config);
for (struct m_config_option *copt = config->opts; copt; copt = copt->next)
m_option_free(copt->opt, copt->data);
return 0;
}
struct m_config *m_config_new(void *talloc_parent, size_t size,
const void *defaults,
const struct m_option *options,
const char *suboptinit)
{
struct m_config *config = talloc(talloc_parent, struct m_config);
talloc_set_destructor(config, config_destroy);
*config = (struct m_config) {
.optstruct_size = size,
.optstruct_defaults = defaults,
.options = options,
.suboptinit = suboptinit,
};
if (size) { // size==0 means a dummy object is created
config->optstruct = talloc_zero_size(config, size);
if (defaults)
memcpy(config->optstruct, defaults, size);
if (options)
add_options(config, NULL, options);
}
if (suboptinit) {
bstr s = bstr0(suboptinit);
int r = m_obj_parse_sub_config(bstr0("internal"), bstr0("-"), &s,
config, 0, NULL);
if (r < 0 || s.len > 0)
mp_msg(MSGT_CFGPARSER, MSGL_ERR, "Internal error: preset broken\n");
}
return config;
}
struct m_config *m_config_from_obj_desc(void *talloc_parent,
struct m_obj_desc *desc)
{
return m_config_new(talloc_parent, desc->priv_size, desc->priv_defaults,
desc->options, desc->init_options);
}
int m_config_set_obj_params(struct m_config *conf, char **args)
{
for (int n = 0; args && args[n * 2 + 0]; n++) {
int r = m_config_set_option(conf, bstr0(args[n * 2 + 0]),
bstr0(args[n * 2 + 1]));
if (r < 0)
return r;
}
return 0;
}
int m_config_initialize_obj(struct m_config *config, struct m_obj_desc *desc,
void **ppriv, char ***pargs)
{
if (desc->priv_size) {
int r = m_config_set_obj_params(config, *pargs);
if (r < 0)
return r;
*ppriv = config->optstruct;
*pargs = NULL;
} else if (*pargs && !strcmp((*pargs)[0], "_oldargs_")) {
// Handle things which still use the old subopt parser
*pargs = (char **)((*pargs)[1]);
} else {
*pargs = NULL;
}
return 0;
}
static void ensure_backup(struct m_config *config, struct m_config_option *co)
{
if (!config->file_local_mode)
return;
if (co->opt->type->flags & M_OPT_TYPE_HAS_CHILD)
return;
if (co->opt->flags & M_OPT_GLOBAL)
return;
if (!co->data)
return;
for (struct m_opt_backup *cur = config->backup_opts; cur; cur = cur->next) {
if (cur->co->data == co->data) // comparing data ptr catches aliases
return;
}
struct m_opt_backup *bc = talloc_ptrtype(NULL, bc);
*bc = (struct m_opt_backup) {
.co = co,
.backup = talloc_zero_size(bc, co->opt->type->size),
};
m_option_copy(co->opt, bc->backup, co->data);
bc->next = config->backup_opts;
config->backup_opts = bc;
}
void m_config_enter_file_local(struct m_config *config)
{
assert(!config->file_local_mode);
config->file_local_mode = true;
for (struct m_config_option *co = config->opts; co; co = co->next) {
if (co->opt->flags & M_OPT_LOCAL)
ensure_backup(config, co);
}
}
void m_config_leave_file_local(struct m_config *config)
{
assert(config->file_local_mode);
config->file_local_mode = false;
while (config->backup_opts) {
struct m_opt_backup *bc = config->backup_opts;
config->backup_opts = bc->next;
m_option_copy(bc->co->opt, bc->co->data, bc->backup);
m_option_free(bc->co->opt, bc->backup);
talloc_free(bc);
}
}
void m_config_mark_file_local(struct m_config *config, const char *opt)
{
struct m_config_option *co = m_config_get_co(config, bstr0(opt));
if (co) {
ensure_backup(config, co);
} else {
mp_tmsg(MSGT_CFGPARSER, MSGL_ERR, "Option %s not found.\n", opt);
}
}
void m_config_mark_all_file_local(struct m_config *config)
{
for (struct m_config_option *co = config->opts; co; co = co->next)
ensure_backup(config, co);
}
// Given an option --opt, add --no-opt (if applicable).
static void add_negation_option(struct m_config *config,
struct m_config_option *parent,
const struct m_option *opt)
{
int value;
if (opt->type == CONF_TYPE_FLAG) {
value = opt->min;
} else if (opt->type == CONF_TYPE_CHOICE) {
// Find out whether there's a "no" choice.
// m_option_parse() should be used for this, but it prints
// unsilenceable error messages.
struct m_opt_choice_alternatives *alt = opt->priv;
for ( ; alt->name; alt++) {
if (strcmp(alt->name, "no") == 0)
break;
}
if (!alt->name)
return;
value = alt->value;
} else {
return;
}
struct m_option *no_opt = talloc_ptrtype(config, no_opt);
*no_opt = (struct m_option) {
.name = talloc_asprintf(no_opt, "no-%s", opt->name),
.type = CONF_TYPE_STORE,
.flags = opt->flags & (M_OPT_NOCFG | M_OPT_GLOBAL | M_OPT_LOCAL |
M_OPT_PRE_PARSE),
.new = opt->new,
.p = opt->p,
.offset = opt->offset,
.max = value,
};
struct m_config_option *co = m_config_add_option(config, "", parent, no_opt);
co->is_generated = true;
// Consider a parent option "--sub" and a subopt "opt". Then the above
// call will add "no-opt". Add "--no-sub-opt" too. (This former call will
// also generate "--sub-no-opt", which is not really needed or wanted, but
// is a consequence of supporting "--sub=...:no-opt".)
if (parent && parent->name && strlen(parent->name)) {
no_opt = talloc_memdup(config, no_opt, sizeof(*no_opt));
no_opt->name = opt->name;
co = m_config_add_option(config, "no-", parent, no_opt);
co->is_generated = true;
}
}
static void add_options(struct m_config *config,
struct m_config_option *parent,
const struct m_option *defs)
{
for (int i = 0; defs[i].name; i++)
m_config_add_option(config, "", parent, defs + i);
}
// Sub-config that adds all its children to the parent.
static bool is_merge_opt(const struct m_option *opt)
{
return (opt->type->flags & M_OPT_TYPE_HAS_CHILD) && strlen(opt->name) == 0;
}
static struct m_config_option *m_config_add_option(struct m_config *config,
const char *prefix,
struct m_config_option *parent,
const struct m_option *arg)
{
assert(config != NULL);
assert(arg != NULL);
// Allocate a new entry for this option
struct m_config_option *co = talloc_zero(config, struct m_config_option);
co->opt = arg;
void *optstruct = config->optstruct;
if (parent && (parent->opt->type->flags & M_OPT_TYPE_USE_SUBSTRUCT))
optstruct = substruct_read_ptr(parent->data);
co->data = arg->new ? (char *)optstruct + arg->offset : arg->p;
if (parent) {
// Merge case: pretend it has no parent (note that we still must follow
// the "real" parent for accessing struct fields)
co->parent = is_merge_opt(parent->opt) ? parent->parent : parent;
}
// Fill in the full name
if (co->parent) {
co->name = talloc_asprintf(co, "%s-%s", co->parent->name, arg->name);
} else {
co->name = (char *)arg->name;
}
co->name = talloc_asprintf(co, "%s%s", prefix, co->name);
// Option with children -> add them
if (arg->type->flags & M_OPT_TYPE_HAS_CHILD) {
if (arg->type->flags & M_OPT_TYPE_USE_SUBSTRUCT) {
const struct m_sub_options *subopts = arg->priv;
if (!substruct_read_ptr(co->data)) {
void *subdata = m_config_alloc_struct(config, subopts);
substruct_write_ptr(co->data, subdata);
}
add_options(config, co, subopts->opts);
} else {
const struct m_option *sub = arg->p;
add_options(config, co, sub);
}
} else {
// Initialize options
if (co->data) {
if (arg->defval) {
// Target data in optstruct is supposed to be cleared (consider
// m_option freeing previously set dynamic data).
m_option_copy(arg, co->data, arg->defval);
} else if (arg->type->flags & M_OPT_TYPE_DYNAMIC) {
// Initialize dynamically managed fields from static data (like
// string options): copy the option into temporary memory,
// clear the original option (to stop m_option from freeing the
// static data), copy it back.
// This would leak memory when done on aliased options.
bool aliased = false;
for (struct m_config_option *i = config->opts; i; i = i->next) {
if (co->data == i->data) {
aliased = true;
break;
}
}
if (!aliased) {
union m_option_value temp = {0};
m_option_copy(arg, &temp, co->data);
memset(co->data, 0, arg->type->size);
m_option_copy(arg, co->data, &temp);
m_option_free(arg, &temp);
}
}
}
}
// pretend that merge options don't exist (only their children matter)
if (!is_merge_opt(co->opt)) {
struct m_config_option **last = &config->opts;
while (*last)
last = &(*last)->next;
*last = co;
}
add_negation_option(config, parent, arg);
return co;
}
struct m_config_option *m_config_get_co(const struct m_config *config,
struct bstr name)
{
struct m_config_option *co;
for (co = config->opts; co; co = co->next) {
struct bstr coname = bstr0(co->name);
if ((co->opt->type->flags & M_OPT_TYPE_ALLOW_WILDCARD)
&& bstr_endswith0(coname, "*")) {
coname.len--;
if (bstrcmp(bstr_splice(name, 0, coname.len), coname) == 0)
return co;
} else if (bstrcmp(coname, name) == 0)
return co;
}
return NULL;
}
const char *m_config_get_positional_option(const struct m_config *config, int n)
{
int pos = 0;
for (struct m_config_option *co = config->opts; co; co = co->next) {
if (!co->is_generated) {
if (pos == n)
return co->name;
pos++;
}
}
return NULL;
}
static int parse_subopts(struct m_config *config, void *optstruct, char *name,
char *prefix, struct bstr param, int flags);
static int m_config_parse_option(struct m_config *config, void *optstruct,
struct bstr name, struct bstr param, int flags)
{
assert(config != NULL);
assert(name.len != 0);
bool set = !(flags & M_SETOPT_CHECK_ONLY);
struct m_config_option *co = m_config_get_co(config, name);
if (!co)
return M_OPT_UNKNOWN;
// This is the only mandatory function
assert(co->opt->type->parse);
if ((flags & M_SETOPT_PRE_PARSE_ONLY) && !(co->opt->flags & M_OPT_PRE_PARSE))
return 0;
// Check if this option isn't forbidden in the current mode
if ((flags & M_SETOPT_FROM_CONFIG_FILE) && (co->opt->flags & M_OPT_NOCFG)) {
mp_tmsg(MSGT_CFGPARSER, MSGL_ERR,
"The %.*s option can't be used in a config file.\n",
BSTR_P(name));
return M_OPT_INVALID;
}
if (config->file_local_mode && (co->opt->flags & M_OPT_GLOBAL)) {
mp_tmsg(MSGT_CFGPARSER, MSGL_ERR,
"The %.*s option is global and can't be set per-file.\n",
BSTR_P(name));
return M_OPT_INVALID;
}
if (config->includefunc && bstr_equals0(name, "include"))
return parse_include(config, param, set);
if (config->use_profiles && bstr_equals0(name, "profile"))
return parse_profile(config, co->opt, name, param, set);
if (config->use_profiles && bstr_equals0(name, "show-profile"))
return show_profile(config, param);
if (bstr_equals0(name, "list-options"))
return list_options(config);
// Option with children are a bit different to parse
if (co->opt->type->flags & M_OPT_TYPE_HAS_CHILD) {
char prefix[110];
assert(strlen(co->name) < 100);
sprintf(prefix, "%s-", co->name);
return parse_subopts(config, optstruct, co->name, prefix, param, flags);
}
if (set)
ensure_backup(config, co);
return m_option_parse(co->opt, name, param, set ? co->data : NULL);
}
static int parse_subopts(struct m_config *config, void *optstruct, char *name,
char *prefix, struct bstr param, int flags)
{
char **lst = NULL;
// Split the argument into child options
int r = m_option_type_subconfig.parse(NULL, bstr0(""), param, &lst);
if (r < 0)
return r;
// Parse the child options
for (int i = 0; lst && lst[2 * i]; i++) {
// Build the full name
char n[110];
if (snprintf(n, 110, "%s%s", prefix, lst[2 * i]) > 100)
abort();
r = m_config_parse_option(config, optstruct, bstr0(n),
bstr0(lst[2 * i + 1]), flags);
if (r < 0) {
if (r > M_OPT_EXIT) {
mp_tmsg(MSGT_CFGPARSER, MSGL_ERR,
"Error parsing suboption %s/%s (%s)\n",
name, lst[2 * i], m_option_strerror(r));
r = M_OPT_INVALID;
}
break;
}
}
talloc_free(lst);
return r;
}
int m_config_parse_suboptions(struct m_config *config, char *name,
char *subopts)
{
if (!subopts || !*subopts)
return 0;
int r = parse_subopts(config, config->optstruct, name, "", bstr0(subopts), 0);
if (r < 0 && r > M_OPT_EXIT) {
mp_tmsg(MSGT_CFGPARSER, MSGL_ERR, "Error parsing suboption %s (%s)\n",
name, m_option_strerror(r));
r = M_OPT_INVALID;
}
return r;
}
int m_config_set_option_ext(struct m_config *config, struct bstr name,
struct bstr param, int flags)
{
int r = m_config_parse_option(config, config->optstruct, name, param, flags);
if (r < 0 && r > M_OPT_EXIT) {
mp_tmsg(MSGT_CFGPARSER, MSGL_ERR, "Error parsing option %.*s (%s)\n",
BSTR_P(name), m_option_strerror(r));
r = M_OPT_INVALID;
}
return r;
}
int m_config_set_option(struct m_config *config, struct bstr name,
struct bstr param)
{
return m_config_set_option_ext(config, name, param, 0);
}
const struct m_option *m_config_get_option(const struct m_config *config,
struct bstr name)
{
struct m_config_option *co;
assert(config != NULL);
co = m_config_get_co(config, name);
if (co)
return co->opt;
else
return NULL;
}
int m_config_option_requires_param(struct m_config *config, bstr name)
{
const struct m_option *opt = m_config_get_option(config, name);
if (opt) {
if (bstr_endswith0(name, "-clr"))
return 0;
return m_option_required_params(opt);
}
return M_OPT_UNKNOWN;
}
static struct m_config *get_defaults(const struct m_config *config)
{
return m_config_new(NULL, config->optstruct_size,
config->optstruct_defaults, config->options,
config->suboptinit);
}
static char *get_option_value_string(const struct m_config *config,
const char *name)
{
struct m_config_option *co = m_config_get_co(config, bstr0(name));
if (!co || !co->data)
return NULL;
return m_option_print(co->opt, co->data);
}
void m_config_print_option_list(const struct m_config *config)
{
char min[50], max[50];
struct m_config_option *co;
int count = 0;
if (!config->opts)
return;
struct m_config *defaults = get_defaults(config);
mp_tmsg(MSGT_CFGPARSER, MSGL_INFO, "Options:\n\n");
for (co = config->opts; co; co = co->next) {
const struct m_option *opt = co->opt;
if (opt->type->flags & M_OPT_TYPE_HAS_CHILD)
continue;
if (co->is_generated)
continue;
mp_msg(MSGT_CFGPARSER, MSGL_INFO, " %-30.30s", co->name);
if (opt->type == &m_option_type_choice) {
mp_msg(MSGT_CFGPARSER, MSGL_INFO, " Choices:");
struct m_opt_choice_alternatives *alt = opt->priv;
for (int n = 0; alt[n].name; n++)
mp_msg(MSGT_CFGPARSER, MSGL_INFO, " %s", alt[n].name);
if (opt->flags & (M_OPT_MIN | M_OPT_MAX))
mp_msg(MSGT_CFGPARSER, MSGL_INFO, " (or an integer)");
} else {
mp_msg(MSGT_CFGPARSER, MSGL_INFO, " %s", co->opt->type->name);
}
if (opt->flags & (M_OPT_MIN | M_OPT_MAX)) {
snprintf(min, sizeof(min), "any");
snprintf(max, sizeof(max), "any");
if (opt->flags & M_OPT_MIN)
snprintf(min, sizeof(min), "%.14g", opt->min);
if (opt->flags & M_OPT_MAX)
snprintf(max, sizeof(max), "%.14g", opt->max);
mp_msg(MSGT_CFGPARSER, MSGL_INFO, " (%s to %s)", min, max);
}
char *def = get_option_value_string(defaults, co->name);
if (def) {
mp_msg(MSGT_CFGPARSER, MSGL_INFO, " (default: %s)", def);
talloc_free(def);
}
if (opt->flags & CONF_GLOBAL)
mp_msg(MSGT_CFGPARSER, MSGL_INFO, " [global]");
if (opt->flags & CONF_NOCFG)
mp_msg(MSGT_CFGPARSER, MSGL_INFO, " [nocfg]");
mp_msg(MSGT_CFGPARSER, MSGL_INFO, "\n");
count++;
}
mp_tmsg(MSGT_CFGPARSER, MSGL_INFO, "\nTotal: %d options\n", count);
talloc_free(defaults);
}
struct m_profile *m_config_get_profile(const struct m_config *config, bstr name)
{
for (struct m_profile *p = config->profiles; p; p = p->next) {
if (bstr_equals0(name, p->name))
return p;
}
return NULL;
}
struct m_profile *m_config_get_profile0(const struct m_config *config,
char *name)
{
return m_config_get_profile(config, bstr0(name));
}
struct m_profile *m_config_add_profile(struct m_config *config, char *name)
{
struct m_profile *p = m_config_get_profile0(config, name);
if (p)
return p;
p = talloc_zero(config, struct m_profile);
p->name = talloc_strdup(p, name);
p->next = config->profiles;
config->profiles = p;
return p;
}
void m_profile_set_desc(struct m_profile *p, char *desc)
{
talloc_free(p->desc);
p->desc = talloc_strdup(p, desc);
}
int m_config_set_profile_option(struct m_config *config, struct m_profile *p,
bstr name, bstr val)
{
int i = m_config_set_option_ext(config, name, val,
M_SETOPT_CHECK_ONLY |
M_SETOPT_FROM_CONFIG_FILE);
if (i < 0)
return i;
p->opts = talloc_realloc(p, p->opts, char *, 2 * (p->num_opts + 2));
p->opts[p->num_opts * 2] = bstrdup0(p, name);
p->opts[p->num_opts * 2 + 1] = bstrdup0(p, val);
p->num_opts++;
p->opts[p->num_opts * 2] = p->opts[p->num_opts * 2 + 1] = NULL;
return 1;
}
void m_config_set_profile(struct m_config *config, struct m_profile *p)
{
if (config->profile_depth > MAX_PROFILE_DEPTH) {
mp_tmsg(MSGT_CFGPARSER, MSGL_WARN,
"WARNING: Profile inclusion too deep.\n");
return;
}
config->profile_depth++;
for (int i = 0; i < p->num_opts; i++) {
m_config_set_option_ext(config,
bstr0(p->opts[2 * i]),
bstr0(p->opts[2 * i + 1]),
M_SETOPT_FROM_CONFIG_FILE);
}
config->profile_depth--;
}
void *m_config_alloc_struct(void *talloc_parent,
const struct m_sub_options *subopts)
{
void *substruct = talloc_zero_size(talloc_parent, subopts->size);
if (subopts->defaults)
memcpy(substruct, subopts->defaults, subopts->size);
return substruct;
}