ucm: Allow empty strings in "${var:...}" substitutions

Recent ucm-conf changes introduce checks like this one in various places:

If.mspk {
        Condition {
                Type String
                Empty "${var:MonoSpeaker}"
        }
        True ...
        False ...
}

The 'Empty "${var:MonoSpeaker}"' part can only every succeed if we do:

Define.MonoSpeaker ""

But so far that would result in an error like this one:

ALSA lib ucm_subs.c:367:(uc_mgr_get_substituted_value) variable '${var:MonoSpeaker}' is not defined in this context!
ALSA lib main.c:983:(snd_use_case_mgr_open) error: failed to import cht-bsw-rt5672 use case configuration -22
alsaucm: error failed to open sound card cht-bsw-rt5672: Invalid argument

This commit fixes this by allowing empty values for "${var:...}"
substitutions.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This commit is contained in:
Hans de Goede 2020-06-27 20:30:52 +02:00 committed by Jaroslav Kysela
parent eb94bf0280
commit f4e48d0d15

View file

@ -262,9 +262,10 @@ static char *rval_var(snd_use_case_mgr_t *uc_mgr, const char *id)
goto __rval; \
}
#define MATCH_VARIABLE2(name, id, fcn) \
#define MATCH_VARIABLE2(name, id, fcn, empty_ok) \
if (strncmp((name), (id), sizeof(id) - 1) == 0) { \
idsize = sizeof(id) - 1; \
allow_empty = (empty_ok); \
fcn2 = (fcn); \
goto __match2; \
}
@ -314,11 +315,11 @@ __std:
MATCH_VARIABLE(value, "${CardName}", rval_card_name, false);
MATCH_VARIABLE(value, "${CardLongName}", rval_card_longname, false);
MATCH_VARIABLE(value, "${CardComponents}", rval_card_components, true);
MATCH_VARIABLE2(value, "${env:", rval_env);
MATCH_VARIABLE2(value, "${sys:", rval_sysfs);
MATCH_VARIABLE2(value, "${var:", rval_var);
MATCH_VARIABLE2(value, "${CardNumberByName:", rval_card_number_by_name);
MATCH_VARIABLE2(value, "${CardIdByName:", rval_card_id_by_name);
MATCH_VARIABLE2(value, "${env:", rval_env, false);
MATCH_VARIABLE2(value, "${sys:", rval_sysfs, false);
MATCH_VARIABLE2(value, "${var:", rval_var, true);
MATCH_VARIABLE2(value, "${CardNumberByName:", rval_card_number_by_name, false);
MATCH_VARIABLE2(value, "${CardIdByName:", rval_card_id_by_name, false);
__merr:
err = -EINVAL;
tmp = strchr(value, '}');