[Powertop] [RFC 2/2] build: use pkg-config for looking for netlink libraries

Also, adds support for using libnl-3.0.
---

I guess that it looks nicer, but it is more intrusive.

BTW, I wasn't able to test in the case with just libnl-2.0.

 configure.ac    |   29 +++++++++++++++++------------
 src/Makefile.am |    6 +++---
 src/tuning/iw.c |    2 +-
 src/tuning/iw.h |    2 +-
 4 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/configure.ac b/configure.ac
index 2d56684..7b10c65 100644
--- a/configure.ac
+++ b/configure.ac
@@ -54,19 +54,24 @@ PKG_CHECK_MODULES([LIBZ], [zlib],[],[
 	AC_SEARCH_LIBS([deflate], [z], [], AC_MSG_ERROR([zlib is required but was not found]), [])
 ])

-has_libnl_ver=0
-PKG_CHECK_MODULES([LIBNL], [libnl-1], [has_libnl_ver=1], [
-	AC_SEARCH_LIBS([nl_socket_alloc], [nl], [has_libnl_ver=2], [
-		     PKG_CHECK_MODULES([LIBNL], [libnl-3.0 libnl-genl-3.0], [has_libnl_ver=3],
-				       [AC_SEARCH_LIBS([nl_socket_alloc], [nl-3 nl-genl-3], [has_libnl_ver=3], [], [])])
-	], [])
+PKG_CHECK_MODULES(LIBNL3, libnl-3.0 libnl-genl-3.0, [
+	NETLINK_CFLAGS=${LIBNL3_CFLAGS}
+	NETLINK_LIBS=${LIBNL3_LIBS}
+], [
+	PKG_CHECK_MODULES(LIBNL2, libnl-2.0, [
+		NETLINK_CFLAGS=${LIBNL2_CFLAGS}
+		NETLINK_LIBS=${LIBNL2_LIBS}
+	], [
+		PKG_CHECK_MODULES(LIBNL1, libnl-1, dummy=yes,
+			AC_MSG_ERROR(Netlink library is required))
+		AC_DEFINE(NEED_LIBNL_COMPAT, 1,
+			[Define to 1 if you need libnl-1 compat functions.])
+		NETLINK_CFLAGS=${LIBNL1_CFLAGS}
+		NETLINK_LIBS=${LIBNL1_LIBS}
+	])
 ])
-if (test "$has_libnl_ver" -eq 0); then
-	AC_MSG_ERROR(libnl is required but not found)
-fi
-if (test "$has_libnl_ver" -gt 1); then
-	AC_DEFINE([HAVE_LIBNL20], [1], [Define if you have libnl-2.0 or higher])
-fi
+AC_SUBST(NETLINK_CFLAGS)
+AC_SUBST(NETLINK_LIBS)

 AC_SEARCH_LIBS([pthread_create], [pthread], [], AC_MSG_ERROR([libpthread is required but was not found]), [])
 AC_SEARCH_LIBS([inet_aton], [resolv], [], AC_MSG_ERROR([libresolv is required but was not found]), [])
diff --git a/src/Makefile.am b/src/Makefile.am
index 935bdab..f2adc41 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -34,14 +34,14 @@ powertop_SOURCES = parameters/persistent.cpp parameters/learn.cpp parameters/par
 		measurement/sysfs.cpp measurement/acpi.h measurement/extech.cpp \
 		measurement/power_supply.h measurement/extech.h main.cpp css.h powertop.css

-powertop_CXXFLAGS = -O2 -g -fno-omit-frame-pointer -fstack-protector -Wall -Wshadow -Wformat -I/usr/include/ $(NCURSES_CFLAGS) $(PCIUTILS_CFLAGS) $(LIBNL_CFLAGS) $(GLIB2_CFLAGS)
+powertop_CXXFLAGS = -O2 -g -fno-omit-frame-pointer -fstack-protector -Wall -Wshadow -Wformat -I/usr/include/ $(NCURSES_CFLAGS) $(PCIUTILS_CFLAGS) $(NETLINK_CFLAGS) $(GLIB2_CFLAGS)


-powertop_CPPFLAGS = -D_FORTIFY_SOURCE=2 $(NCURSES_CFLAGS) $(PCIUTILS_CFLAGS) $(LIBNL_CFLAGS) $(GLIB2_CFLAGS) $(LIBZ_CFLAGS)
+powertop_CPPFLAGS = -D_FORTIFY_SOURCE=2 $(NCURSES_CFLAGS) $(PCIUTILS_CFLAGS) $(NETLINK_CFLAGS) $(GLIB2_CFLAGS) $(LIBZ_CFLAGS)

 powertop_LDADD = ../pevent/libparseevent.la

-AM_LDFLAGS = $(LIBS) $(NCURSES_LIBS) $(PCIUTILS_LIBS) $(LIBNL_LIBS) $(LIBZ_LIBS) $(NCURES_LIBS) $(PTHREAD_LIBS)  $(RESOLV_LIBS)
+AM_LDFLAGS = $(LIBS) $(NCURSES_LIBS) $(PCIUTILS_LIBS) $(NETLINK_LIBS) $(LIBZ_LIBS) $(NCURES_LIBS) $(PTHREAD_LIBS)  $(RESOLV_LIBS)

 BUILT_SOURCES = css.h
 CLEANFILES = css.h
diff --git a/src/tuning/iw.c b/src/tuning/iw.c
index aeba3fd..ba40d22 100644
--- a/src/tuning/iw.c
+++ b/src/tuning/iw.c
@@ -50,7 +50,7 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include "iw.h"


-#ifndef HAVE_LIBNL20
+#ifdef NEED_LIBNL_COMPAT
 /* libnl 2.0 compatibility code */

 static inline struct nl_handle *nl_socket_alloc(void)
diff --git a/src/tuning/iw.h b/src/tuning/iw.h
index acf132d..3b82aec 100644
--- a/src/tuning/iw.h
+++ b/src/tuning/iw.h
@@ -46,7 +46,7 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include "config.h"
 #endif

-#ifndef HAVE_LIBNL20
+#ifdef NEED_LIBNL_COMPAT
 #define nl_sock nl_handle
 #endif

--
1.7.10.2