options: support parsing values into substructs

Add an alternate mode for option parser objects (struct m_config)
which is not inherently tied to any particular instance of an option
value struct. Instead, this type or parsers can be used to initialize
defaults in or parse values into a struct given as a parameter. They
do not have the save slot functionality used for main player
configuration. The new functionality will be used to replace the
separate subopt_helper.c parsing code that is currently used to parse
per-object suboptions in VOs etc.

Previously, option default values were handled by initializing them in
external code before creating a parser. This initialization was done
with constants even for dynamically-allocated types like strings.
Because trying to free a pointer to a constant would cause a crash
when trying to replace the default with another value, parser
initialization code then replaced all the original defaults with
dynamically-allocated copies. This replace-with-copy behavior is no
longer supported for new-style options; instead the option definition
itself may contain a default value (new OPTDEF macros), and the new
function m_config_initialize() is used to set all options to their
default values. Convert the existing initialized dynamically allocated
options in main config (the string options --dumpfile, --term-osd-esc,
--input=conf) to use this. Other non-dynamic ones could be later
converted to use this style of initialization too.

There's currently no public call to free all dynamically allocated
options in a given option struct because I intend to use talloc
functionality for that (make them children of the struct and free with
it).

1 files changed, 3 insertions, 16 deletions

diff --git a/m_option.c b/m_option.c
index 55a58fc35c..7e701765b7 100644
--- a/m_option.c
+++ b/m_option.c
@@ -821,14 +821,13 @@ const m_option_type_t m_option_type_print_func = {
 static int parse_subconf(const m_option_t *opt, struct bstr name,
                          struct bstr param, bool ambiguous_param, void *dst)
 {
-    int nr = 0, i;
+    int nr = 0;
     char **lst = NULL;
 
     if (param.len == 0)
         return M_OPT_MISSING_PARAM;
 
     struct bstr p = param;
-    const struct m_option *subopts = opt->p;
 
     while (p.len) {
         int optlen = bstrcspn(p, ":=");
@@ -874,23 +873,11 @@ static int parse_subconf(const m_option_t *opt, struct bstr name,
             return M_OPT_INVALID;
         }
 
-        for (i = 0; subopts[i].name; i++)
-            if (!bstrcmp0(subopt, subopts[i].name))
-                break;
-        if (!subopts[i].name) {
-            mp_msg(MSGT_CFGPARSER, MSGL_ERR,
-                   "Option %.*s: Unknown suboption %.*s\n",
-                   BSTR_P(name), BSTR_P(subopt));
-            return M_OPT_UNKNOWN;
-        }
-        int r = m_option_parse(&subopts[i], subopt, subparam, false, NULL);
-        if (r < 0)
-            return r;
         if (dst) {
             lst = talloc_realloc(NULL, lst, char *, 2 * (nr + 2));
-            lst[2 * nr] = bstrdup0(NULL, subopt);
+            lst[2 * nr] = bstrdup0(lst, subopt);
             lst[2 * nr + 1] = subparam.len == 0 ? NULL :
-                bstrdup0(NULL, subparam);
+                bstrdup0(lst, subparam);
             memset(&lst[2 * (nr + 1)], 0, 2 * sizeof(char *));
             nr++;
         }