ucm: allow to use the defined variables in the substitution argument

Example (set variable 'Module' to the kernel module name for the given card):

  Define.SysfsPath "class/sound/card${CardNumber}/device/driver"
  Define.Module "${sys:$SysfsPath}"

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/src/ucm/ucm_subs.c b/src/ucm/ucm_subs.c
index b2a1845..8d78ecf 100644 (file)
--- a/src/ucm/ucm_subs.c
+++ b/src/ucm/ucm_subs.c
@@ -246,19 +246,8 @@ static char *rval_var(snd_use_case_mgr_t *uc_mgr, const char *id)
 #define MATCH_VARIABLE2(name, id, fcn)                                 \
        if (strncmp((name), (id), sizeof(id) - 1) == 0) {               \
                idsize = sizeof(id) - 1;                                \
-               tmp = strchr(value + idsize, '}');                      \
-               if (tmp) {                                              \
-                       rvalsize = tmp - (value + idsize);              \
-                       if (rvalsize > sizeof(v2)) {                    \
-                               err = -ENOMEM;                          \
-                               goto __error;                           \
-                       }                                               \
-                       strncpy(v2, value + idsize, rvalsize);          \
-                       v2[rvalsize] = '\0';                            \
-                       idsize += rvalsize + 1;                         \
-                       rval = fcn(uc_mgr, v2);                         \
-                       goto __rval;                                    \
-               }                                                       \
+               fcn2 = (fcn);                                           \
+               goto __match2;                                          \
        }
 
 int uc_mgr_get_substituted_value(snd_use_case_mgr_t *uc_mgr,
@@ -267,8 +256,9 @@ int uc_mgr_get_substituted_value(snd_use_case_mgr_t *uc_mgr,
 {
        size_t size, nsize, idsize, rvalsize, dpos = 0;
        const char *tmp;
-       char *r, *nr, *rval, v2[32];
+       char *r, *nr, *rval, v2[48];
        bool ignore_error, allow_empty;
+       char *(*fcn2)(snd_use_case_mgr_t *, const char *id);
        int err;
 
        if (value == NULL)
@@ -294,6 +284,7 @@ __std:
                        goto __std;
                }
                allow_empty = false;
+               fcn2 = NULL;
                MATCH_VARIABLE(value, "${OpenName}", rval_open_name, false);
                MATCH_VARIABLE(value, "${ConfTopDir}", rval_conf_topdir, false);
                MATCH_VARIABLE(value, "${ConfDir}", rval_conf_dir, false);
@@ -308,6 +299,7 @@ __std:
                MATCH_VARIABLE2(value, "${sys:", rval_sysfs);
                MATCH_VARIABLE2(value, "${var:", rval_var);
                MATCH_VARIABLE2(value, "${CardIdByName:", rval_card_id_by_name);
+__merr:
                err = -EINVAL;
                tmp = strchr(value, '}');
                if (tmp) {
@@ -318,6 +310,31 @@ __std:
                        uc_error("variable reference '%s' is not complete", value);
                }
                goto __error;
+__match2:
+               tmp = strchr(value + idsize, '}');
+               if (tmp) {
+                       rvalsize = tmp - (value + idsize);
+                       if (rvalsize > sizeof(v2)) {
+                               err = -ENOMEM;
+                               goto __error;
+                       }
+                       strncpy(v2, value + idsize, rvalsize);
+                       v2[rvalsize] = '\0';
+                       idsize += rvalsize + 1;
+                       if (*v2 == '$' && uc_mgr->conf_format >= 3) {
+                               tmp = uc_mgr_get_variable(uc_mgr, v2 + 1);
+                               if (tmp == NULL) {
+                                       uc_error("define '%s' is not reachable in this context!", v2 + 1);
+                                       rval = NULL;
+                               } else {
+                                       rval = fcn2(uc_mgr, tmp);
+                               }
+                       } else {
+                               rval = fcn2(uc_mgr, v2);
+                       }
+                       goto __rval;
+               }
+               goto __merr;
 __rval:
                if (rval == NULL || (!allow_empty && rval[0] == '\0')) {
                        free(rval);