[alsa-devel] [PATCH 24/29] mixer: remove alloca() from get_enum_item_ops()

[Takashi Sakamoto]

Both of alloca() and automatic variables keep storages on stack, while
the former generates more instructions than the latter. It's better to use
the latter if the size of storage is computable at pre-compile or compile
time; i.e. just for structures.

This commit obsolete usages of alloca() with automatic variables.

Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
 src/mixer/simple_none.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/mixer/simple_none.c b/src/mixer/simple_none.c
index ab2b151..3362f82 100644
--- a/src/mixer/simple_none.c
+++ b/src/mixer/simple_none.c
@@ -1342,7 +1342,7 @@ static int get_enum_item_ops(snd_mixer_elem_t *elem,
 			     unsigned int *itemp)
 {
 	selem_none_t *s = snd_mixer_elem_get_private(elem);
-	snd_ctl_elem_value_t *ctl;
+	snd_ctl_elem_value_t ctl = {0};
 	snd_hctl_elem_t *helem;
 	int err;
 
@@ -1352,10 +1352,9 @@ static int get_enum_item_ops(snd_mixer_elem_t *elem,
 	if (!helem) helem = s->ctls[CTL_PLAYBACK_ENUM].elem;
 	if (!helem) helem = s->ctls[CTL_CAPTURE_ENUM].elem;
 	assert(helem);
-	snd_ctl_elem_value_alloca(&ctl);
-	err = snd_hctl_elem_read(helem, ctl);
+	err = snd_hctl_elem_read(helem, &ctl);
 	if (! err)
-		*itemp = snd_ctl_elem_value_get_enumerated(ctl, channel);
+		*itemp = snd_ctl_elem_value_get_enumerated(&ctl, channel);
 	return err;
 }
 
-- 
2.7.4