ucm: substitute the merged tree completely

We need to define the common shared configuration like for multiple
HDMI devices or so. Substitute the whole merged configuration tree
including identifiers.

Fixes: https://github.com/alsa-project/alsa-lib/issues/67
Fixes: dcef48f13d
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

src/ucm/ucm_cond.c

@@ -401,7 +401,7 @@ int uc_mgr_evaluate_condition(snd_use_case_mgr_t *uc_mgr,
 		err = uc_mgr_evaluate_inplace(uc_mgr, a);
 		if (err < 0)
 			return err;
-		err = uc_mgr_config_tree_merge(parent, a, before, after);
+		err = uc_mgr_config_tree_merge(uc_mgr, parent, a, before, after);
 		if (err < 0)
 			return err;
 		snd_config_delete(a);

src/ucm/ucm_include.c

@@ -206,7 +206,8 @@ static int compound_merge(const char *id,
 	return 0;
 }
 
-int uc_mgr_config_tree_merge(snd_config_t *parent, snd_config_t *new_ctx,
+int uc_mgr_config_tree_merge(snd_use_case_mgr_t *uc_mgr,
+			     snd_config_t *parent, snd_config_t *new_ctx,
 			     snd_config_t *before, snd_config_t *after)
 {
 	snd_config_iterator_t i, next;
@@ -214,6 +215,10 @@ int uc_mgr_config_tree_merge(snd_config_t *parent, snd_config_t *new_ctx,
 	const char *id;
 	int err;
 
+	err = uc_mgr_substitute_tree(uc_mgr, new_ctx);
+	if (err < 0)
+		return err;
+
 	snd_config_for_each(i, next, new_ctx) {
 		n = snd_config_iterator_entry(i);
 		err = snd_config_remove(n);
@@ -271,7 +276,7 @@ int uc_mgr_evaluate_include(snd_use_case_mgr_t *uc_mgr,
 		err = uc_mgr_evaluate_inplace(uc_mgr, a);
 		if (err < 0)
 			return err;
-		err = uc_mgr_config_tree_merge(parent, a, before, after);
+		err = uc_mgr_config_tree_merge(uc_mgr, parent, a, before, after);
 		if (err < 0)
 			return err;
 		snd_config_delete(a);

src/ucm/ucm_local.h

@@ -307,7 +307,11 @@ int uc_mgr_get_substituted_value(snd_use_case_mgr_t *uc_mgr,
 				 char **_rvalue,
 				 const char *value);
 
-int uc_mgr_config_tree_merge(snd_config_t *parent, snd_config_t *new_ctx,
+int uc_mgr_substitute_tree(snd_use_case_mgr_t *uc_mgr,
+			   snd_config_t *node);
+
+int uc_mgr_config_tree_merge(snd_use_case_mgr_t *uc_mgr,
+			     snd_config_t *parent, snd_config_t *new_ctx,
 			     snd_config_t *before, snd_config_t *after);
 
 int uc_mgr_evaluate_inplace(snd_use_case_mgr_t *uc_mgr,

src/ucm/ucm_subs.c

@@ -395,3 +395,56 @@ __error:
 	free(r);
 	return err;
 }
+
+static inline int uc_mgr_substitute_check(const char *s)
+{
+	return s && strstr(s, "${") != NULL;
+}
+
+int uc_mgr_substitute_tree(snd_use_case_mgr_t *uc_mgr, snd_config_t *node)
+{
+	snd_config_iterator_t i, next;
+	snd_config_t *n;
+	const char *id, *s2;
+	char *s;
+	int err;
+
+	err = snd_config_get_id(node, &id);
+	if (err < 0)
+		return err;
+	if (uc_mgr_substitute_check(id)) {
+		err = uc_mgr_get_substituted_value(uc_mgr, &s, id);
+		if (err < 0)
+			return err;
+		err = snd_config_set_id(node, s);
+		free(s);
+		if (err < 0) {
+			uc_error("unable to set substituted id '%s' (old id '%s')", s, id);
+			return err;
+		}
+	}
+	if (snd_config_get_type(node) != SND_CONFIG_TYPE_COMPOUND) {
+		if (snd_config_get_type(node) == SND_CONFIG_TYPE_STRING) {
+			err = snd_config_get_string(node, &s2);
+			if (err < 0)
+				return err;
+			if (!uc_mgr_substitute_check(s2))
+				return 0;
+			err = uc_mgr_get_substituted_value(uc_mgr, &s, s2);
+			if (err < 0)
+				return err;
+			err = snd_config_set_string(node, s);
+			free(s);
+			if (err < 0)
+				return err;
+		}
+		return 0;
+	}
+	snd_config_for_each(i, next, node) {
+		n = snd_config_iterator_entry(i);
+		err = uc_mgr_substitute_tree(uc_mgr, n);
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}