From: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Date: Thu, 14 Jul 2016 14:07:40 +0000 (+0900)
Subject: conf: remove alloca() from snd_determine_driver()
X-Git-Tag: v1.1.2~54
X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=b500e16ce4ce0071139d5520bc5cc9a87fccf8a1;p=alsa-lib.git

conf: remove alloca() from snd_determine_driver()

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@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---

diff --git a/src/confmisc.c b/src/confmisc.c
index ae0275ff..3f12e340 100644
--- a/src/confmisc.c
+++ b/src/confmisc.c
@@ -664,7 +664,7 @@ SND_DLSYM_BUILD_VERSION(snd_func_private_string, SND_CONFIG_DLSYM_VERSION_EVALUA
 int snd_determine_driver(int card, char **driver)
 {
 	snd_ctl_t *ctl = NULL;
-	snd_ctl_card_info_t *info;
+	snd_ctl_card_info_t info = {0};
 	char *res = NULL;
 	int err;
 
@@ -674,13 +674,12 @@ int snd_determine_driver(int card, char **driver)
 		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;
 	}
-	res = strdup(snd_ctl_card_info_get_driver(info));
+	res = strdup(snd_ctl_card_info_get_driver(&info));
 	if (res == NULL)
 		err = -ENOMEM;
 	else {