[alsa-devel] [PATCH 25/34] conf: remove alloca() from snd_func_card_name()

Takashi Sakamoto o-takashi at sakamocchi.jp
Thu Jul 14 16:07:42 CEST 2016


Both of alloca() and automatic variables keeps 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/confmisc.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/confmisc.c b/src/confmisc.c
index 7763511..fd10b34 100644
--- a/src/confmisc.c
+++ b/src/confmisc.c
@@ -913,7 +913,7 @@ int snd_func_card_name(snd_config_t **dst, snd_config_t *root,
 		       snd_config_t *src, snd_config_t *private_data)
 {
 	snd_ctl_t *ctl = NULL;
-	snd_ctl_card_info_t *info;
+	snd_ctl_card_info_t info = {0};
 	const char *id;
 	int card, err;
 	
@@ -925,8 +925,7 @@ int snd_func_card_name(snd_config_t **dst, snd_config_t *root,
 		SNDERR("could not open control for card %i", card);
 		goto __error;
 	}
-	snd_ctl_card_info_alloca(&info);
-	err = snd_ctl_card_info(ctl, info);
+	err = snd_ctl_card_info(ctl, &info);
 	if (err < 0) {
 		SNDERR("snd_ctl_card_info error: %s", snd_strerror(err));
 		goto __error;
@@ -934,7 +933,7 @@ int snd_func_card_name(snd_config_t **dst, snd_config_t *root,
 	err = snd_config_get_id(src, &id);
 	if (err >= 0)
 		err = snd_config_imake_safe_string(dst, id,
-					      snd_ctl_card_info_get_name(info));
+					snd_ctl_card_info_get_name(&info));
       __error:
       	if (ctl)
       		snd_ctl_close(ctl);
-- 
2.7.4



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