[alsa-utils][PATCH 07/14] autotools: preparation to use memfd_create(2)

[Takashi Sakamoto]

This is a preparation to use memfd_create(2) system call for test programs
of axfer. The system call was introduced at Linux kernel v3.17 and
relatively new.

For safe, this commit adds detection of memfd_create() in autotools side
so that application can handle the case not to detect.

Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
 configure.ac | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/configure.ac b/configure.ac
index 7005ccc..ff3e1f6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -62,6 +62,11 @@ AC_CHECK_LIB([ffado], [ffado_streaming_init], [have_ffado="yes"], [have_ffado="n
 AS_IF([test x"$have_ffado" = xyes],
       [AC_DEFINE([WITH_FFADO], [1], [Define if FFADO library is available])])
 
+# Test programs for axfer use shm by memfd_create(2). If not supported, open(2) is used alternatively.
+AC_CHECK_FUNC([memfd_create], [have_memfd_create="yes"], [have_memfd_create="no"])
+AS_IF([test x$have_memfd_create = xyes],
+      [AC_DEFINE([HAVE_MEMFD_CREATE], [1], [Define if Linux kernel supports memfd_create system call])])
+
 AM_CONDITIONAL(HAVE_PCM, test "$have_pcm" = "yes")
 AM_CONDITIONAL(HAVE_MIXER, test "$have_mixer" = "yes")
 AM_CONDITIONAL(HAVE_RAWMIDI, test "$have_rawmidi" = "yes")
-- 
2.27.0