[PATCH alsa-lib] utils/alsa.m4: conditionally enable libdl in AM_PATH_ALSA m4 macro

From: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
To: alsa-devel@alsa-project.org
Cc: "Jörg Krause" <joerg.krause@embedded.rocks>,
	"Thomas De Schampheleire" <thomas.de.schampheleire@gmail.com>,
	"Thomas Petazzoni" <thomas.petazzoni@bootlin.com>
Subject: [PATCH alsa-lib] utils/alsa.m4: conditionally enable libdl in AM_PATH_ALSA m4 macro
Date: Thu,  1 Nov 2018 15:40:07 +0100	[thread overview]
Message-ID: <20181101144007.1507-1-thomas.petazzoni@bootlin.com> (raw)

From: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>

The AM_PATH_ALSA macro in utils/alsa.m4 unconditionally uses
-ldl. This breaks compilation of alsa-utils (and probably other
packages using this macro) for targets that do not support dynamic
loading.

This patch updates the macro to check if dlopen is available, and use
that result to conditionally add -ldl to the list of libraries.

Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
 utils/alsa.m4 | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/utils/alsa.m4 b/utils/alsa.m4
index e12310df..a5c5a292 100644
--- a/utils/alsa.m4
+++ b/utils/alsa.m4
@@ -44,6 +44,8 @@ if test "$alsa_inc_prefix" != "" ; then
 fi
 AC_MSG_RESULT($ALSA_CFLAGS)
 
+AC_CHECK_LIB(c, dlopen, LIBDL="", [AC_CHECK_LIB(dl, dlopen, LIBDL="-ldl")])
+
 dnl add any special lib dirs
 AC_MSG_CHECKING(for ALSA LDFLAGS)
 if test "$alsa_prefix" != "" ; then
@@ -52,7 +54,7 @@ if test "$alsa_prefix" != "" ; then
 fi
 
 dnl add the alsa library
-ALSA_LIBS="$ALSA_LIBS -lasound -lm -ldl -lpthread"
+ALSA_LIBS="$ALSA_LIBS -lasound -lm $LIBDL -lpthread"
 LIBS="$ALSA_LIBS $LIBS"
 AC_MSG_RESULT($ALSA_LIBS)
 
-- 
2.14.4

_______________________________________________
Alsa-devel mailing list
Alsa-devel@alsa-project.org
http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
