alsamixer: define _GNU_SOURCE to get exp10

Fixes Master, Headphones and Speaker stuck at -8 percentage after
building with Clang 7.0.1 and getting warned about implicit declaration
of exp10, which is behind _GNU_SOURCE as a non-standard feature. Thanks
Takashi Iwai for the CFLAGS suggestion on the mailing list. GCC build is
not affected, so not adding a compiler check to the configure script.

uClibc-ng has got exp10 since 1.0.12, so the fallback macro is no longer
needed. However, alsa-utils relies on gettext so might need further
patches to actually work on uClibc systems.

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

diff --git a/alsamixer/Makefile.am b/alsamixer/Makefile.am
index 259b29e..249e8f8 100644 (file)
--- a/alsamixer/Makefile.am
+++ b/alsamixer/Makefile.am
@@ -1,4 +1,4 @@
-AM_CFLAGS = @CURSES_CFLAGS@ -DCURSESINC="@CURSESINC@"
+AM_CFLAGS = -D_GNU_SOURCE @CURSES_CFLAGS@ -DCURSESINC="@CURSESINC@"
 LDADD = @CURSESLIB@
 
 bin_PROGRAMS = alsamixer

diff --git a/alsamixer/volume_mapping.c b/alsamixer/volume_mapping.c
index 94bd0fe..48cfbe2 100644 (file)
--- a/alsamixer/volume_mapping.c
+++ b/alsamixer/volume_mapping.c
@@ -36,11 +36,6 @@
 #include <stdbool.h>
 #include "volume_mapping.h"
 
-#ifdef __UCLIBC__
-/* 10^x = 10^(log e^x) = (e^x)^log10 = e^(x * log 10) */
-#define exp10(x) (exp((x) * log(10)))
-#endif /* __UCLIBC__ */
-
 #define MAX_LINEAR_DB_SCALE    24
 
 static inline bool use_linear_dB_scale(long dBmin, long dBmax)