til_settings: label til_settings_t instances

This adds a mandatory label string to til_setttings_new() and
updates call sites accordingly.

For now the root-level settings created by main.c are simply
named "module" and "video" respectively.  Any nested settings
creations on behalf of modules will be labeled using the module's
name the settings are being created for use with.

This might evolve with time, for now it's just a minimum churn
kind of decision.  I can see it changing such that the top-level
settings also become labeled by the module/video driver name
rather than the obtuse "module" "video" strings.

How these will be leveraged is unclear presently.  At the least
it'll be nice to have a label for debugging til_settings_t
heirarchies once recursive settings support lands.  In a sense
this is a preparatory commit for that work.  But I could see the
labels ending up in serialization contents as markup/syntactic
sugar just to self-document things as well.

There might also be a need to address til_settings_t instances in
the settings heirarchy, which may be something like a
"label/label/label/label" path style thing - though there'd be a
need to deal with name collisions in that approach.

I'm just thinking a bit about how knobs will become addressed
when those become a real thing.  The settings label heirarchy
might be the convenient place to name everything in a tree, which
knobs could then inherit their parent paths from under which
their respective knob labels will reside.  For the whole name
collision issue there could just be some builtin settings keys
for overriding the automatic module name labeling, something
like:

--module=compose,layers=checkers\,label=first\,fill_module=shapes:checkers\,label=second\,fill_module=shapes

would result in:
/module/first/shapes
/module/second/shapes

or in a world where the root settings weren't just named "module"
and "video":
/compose/first/shapes
/compose/second/shapes

then if there were knobs under checkers and shapes, say checkers
had a "foo" knob and checkers had a "bar" knob, they'd be under
.knobs in each directory:

/compose/first/.knobs/foo
/compose/first/shapes/.knobs/bar
/compose/second/.knobs/foo
/compose/second/shapes/.knobs/bar

something along those lines, and of course if compose had knobs
they'd be under /compose/.knobs

This is just a brain dump and will surely all change before
implemented.

4 files changed, 13 insertions, 6 deletions

diff --git a/src/main.c b/src/main.c
index 2e0229e..54abe18 100644
--- a/src/main.c
+++ b/src/main.c
@@ -219,11 +219,11 @@ static int setup_from_args(til_args_t *args, setup_t *res_setup, const til_setti
 	 */
 	srand(setup.seed);
 
-	setup.module_settings = til_settings_new(args->module);
+	setup.module_settings = til_settings_new("module", args->module);
 	if (!setup.module_settings)
 		goto _err;
 
-	setup.video_settings = til_settings_new(args->video);
+	setup.video_settings = til_settings_new("video", args->video);
 	if (!setup.video_settings)
 		goto _err;
 
diff --git a/src/til.c b/src/til.c
index 489fcf1..58e52bb 100644
--- a/src/til.c
+++ b/src/til.c
@@ -327,7 +327,7 @@ int til_module_randomize_setup(const til_module_t *module, unsigned seed, til_se
 	if (!module->setup)
 		return 0;
 
-	settings = til_settings_new(NULL);
+	settings = til_settings_new(module->name, NULL);
 	if (!settings)
 		return -ENOMEM;
 
diff --git a/src/til_settings.c b/src/til_settings.c
index 3e26686..9fce32f 100644
--- a/src/til_settings.c
+++ b/src/til_settings.c
@@ -31,6 +31,7 @@ char * strndup(const char *s, size_t n)
 
 /* Split form of key=value[,key=value...] settings string */
 typedef struct til_settings_t {
+	const char	*label;
 	unsigned	num;
 	til_setting_t	**settings;
 } til_settings_t;
@@ -62,7 +63,7 @@ static int add_value(til_settings_t *settings, const char *key, const char *valu
 
 
 /* split settings_string into a data structure */
-til_settings_t * til_settings_new(const char *settings_string)
+til_settings_t * til_settings_new(const char *label, const char *settings_string)
 {
 	til_settings_fsm_state_t	state = TIL_SETTINGS_FSM_STATE_KEY;
 	const char			*p, *token;
@@ -71,9 +72,15 @@ til_settings_t * til_settings_new(const char *settings_string)
 	char				*value_buf;
 	size_t				value_sz;
 
+	assert(label);
+
 	settings = calloc(1, sizeof(til_settings_t));
 	if (!settings)
-		return NULL;
+		goto _err;
+
+	settings->label = strdup(label);
+	if (!settings->label)
+		goto _err;
 
 	if (!settings_string)
 		return settings;
diff --git a/src/til_settings.h b/src/til_settings.h
index df8a307..93c0ed8 100644
--- a/src/til_settings.h
+++ b/src/til_settings.h
@@ -33,7 +33,7 @@ struct til_setting_t {
 	void				*user_data;
 };
 
-til_settings_t * til_settings_new(const char *settings);
+til_settings_t * til_settings_new(const char *label, const char *settings);
 til_settings_t * til_settings_free(til_settings_t *settings);
 const char * til_settings_get_value(const til_settings_t *settings, const char *key, til_setting_t **res_setting);
 const char * til_settings_get_key(const til_settings_t *settings, unsigned pos, til_setting_t **res_setting);