options: add a mechanism to make sub-option replacement slightly easier

Instead of requiring each VO or AO to manually add members to MPOpts and
the global option table, make it possible to register them automatically
via vo_driver/ao_driver.global_opts members. This avoids modifying
options.c/options.h every time, including having to duplicate the exact
ifdeffery used to enable a driver.

1 files changed, 16 insertions, 0 deletions

diff --git a/options/m_config.c b/options/m_config.c
index 3d1355904e..18a9ad4de7 100644
--- a/options/m_config.c
+++ b/options/m_config.c
@@ -406,6 +406,18 @@ static void add_sub_options(struct m_config *config,
     add_options(config, &next, new_optstruct, new_optstruct_def, subopts->opts);
 }
 
+static void add_global_subopts(struct m_config *config,
+                               const struct m_obj_list *list)
+{
+    struct m_obj_desc desc;
+    for (int n = 0; ; n++) {
+        if (!list->get_desc(&desc, n))
+            break;
+        if (desc.global_opts)
+            add_sub_options(config, NULL, desc.global_opts);
+    }
+}
+
 // Initialize a field with a given value. In case this is dynamic data, it has
 // to be allocated and copied. src can alias dst, also can be NULL.
 static void init_opt_inplace(const struct m_option *opt, void *dst,
@@ -477,6 +489,10 @@ static void m_config_add_option(struct m_config *config,
             init_opt_inplace(arg, co.data, co.default_data);
     }
 
+    // (The deprecation_message check is a hack to exclude --vo-defaults etc.)
+    if (arg->type == &m_option_type_obj_settings_list && !arg->deprecation_message)
+        add_global_subopts(config, (const struct m_obj_list *)arg->priv);
+
     if (arg->name[0]) // no own name -> hidden
         MP_TARRAY_APPEND(config, config->opts, config->num_opts, co);
 }