Compiling syslog-ng v2.1.4 with --as-needed enabled fails to link against librt from glibc Reproducible: Always Steps to Reproduce: 1. Enable LDFLAGS="-Wl,--as-needed" 2. Possibly linked to glibc? Version used 2.9_p20081201-r2 USE="gd (multilib) nls -debug -glibc-omitfp (-hardened) -profile (-selinux) -vanilla" 3. Emerge syslog-ng Actual Results: x86_64-pc-linux-gnu-gcc -march=athlon64-O2 -pipe -Wall -Wl,--as-needed -o syslog-ng main.o libsyslog-ng.a -lnsl -lrt -Wl,-Bstatic -lfl -pthread -lgthread-2.0 -lrt -lglib-2.0 -levtlog -lwrap -Wl,-Bdynamic -ldbi -ldl /usr/lib/gcc/x86_64-pc-linux-gnu/4.3.3/../../../../lib64/librt.a(clock_gettime.o): In function `hp_timing_gettime': (.text+0x6a): undefined reference to `_dl_cpuclock_offset' collect2: ld returned 1 exit status make[2]: *** [syslog-ng] Error 1 make[2]: Leaving directory `/var/tmp/portage/app-admin/syslog-ng-2.1.4/work/syslog-ng-2.1.4/src' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/var/tmp/portage/app-admin/syslog-ng-2.1.4/work/syslog-ng-2.1.4' make: *** [all] Error 2 ~ Portage 2.2_rc28 (default/linux/amd64/2008.0/desktop, gcc-4.3.3, glibc-2.9_p20081201-r2, 2.6.29-gentoo x86_64) ================================================================= System uname: Linux-2.6.29-gentoo-x86_64-AMD_Athlon-tm-_64_X2_Dual_Core_Processor_3800+-with-glibc2.2.5 Timestamp of tree: Thu, 09 Apr 2009 13:45:01 +0000 distcc 2.18.3 x86_64-pc-linux-gnu (protocols 1 and 2) (default port 3632) [disabled] app-shells/bash: 4.0_p17 dev-java/java-config: 1.3.7-r1, 2.1.7 dev-lang/python: 2.4.4-r15, 2.5.4-r2 dev-python/pycrypto: 2.0.1-r6 dev-util/cmake: 2.6.3-r1 sys-apps/baselayout: 2.0.0 sys-apps/openrc: 0.4.3-r1 sys-apps/sandbox: 1.9 sys-devel/autoconf: 2.13, 2.63-r1 sys-devel/automake: 1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r2, 1.10.2 sys-devel/binutils: 2.19.1-r1 sys-devel/gcc-config: 1.4.1 sys-devel/libtool: 2.2.6a virtual/os-headers: 2.6.28-r1 ACCEPT_KEYWORDS="amd64 ~amd64" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=athlon64 -O2 -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/share/config" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/env.d/java/ /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo /etc/texmf/web2c /etc/udev/rules.d" CXXFLAGS="-march=athlon64 -O2 -pipe" DISTDIR="/usr/portage/distfiles" FEATURES="distlocks fixpackages parallel-fetch preserve-libs protect-owned sandbox sfperms strict unmerge-orphans userfetch" GENTOO_MIRRORS="http://distfiles.gentoo.org http://distro.ibiblio.org/pub/linux/distributions/gentoo" LANG="en_GB" LDFLAGS="-Wl,--as-needed" LINGUAS="en en_GB" MAKEOPTS="-j3" PKGDIR="/usr/portage/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/portage/layman/sunrise /usr/local/portage/layman/java-overlay /usr/local/portage" SYNC="rsync://rsync.europe.gentoo.org/gentoo-portage" USE="3dnow X aac acpi alsa amd64 berkdb blender-game bluetooth branding bzip2 cairo cdinstall cdparanoia cdr cdrom cli consolekit cracklib crypt cvs dbus deprecated divx dvd dvdnav dvdr dvdread emboss encode evo fam ffmpeg fortran gcj gd gif glitz gmedia gphoto2 gpm graphviz gtk hal history htmlhandbook iconv ifp imlib java java6 jpeg kde kpathsea libnotify libsamplerate live lm_sensors mad midi mikmod mjpeg mmx mp3 mpeg mtp mudflap multilib ncurses nfs nls nptl nptlonly nsplugin nvidia ofx oggopenal openexr opengl openmp pam pcre pdf perl plotutils png ppds pppd python qt3 qt3support qt4 quicktime quotes readline realmedia reflection sdl session smp spell spl sql sse sse2 ssl startup-notification subversion svg sysfs tcpd theora threads threadsafe tiff truetype unicode usb visualizationvorbis wmp x264 xcomposite xinerama xml xorg xscreensaver xulrunner xv xvid zeroconf zlib" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul mulaw multi null plug rate route share shm softvol" APACHE2_MODULES="actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_defaultauthz_groupfile authz_host authz_owner authz_user autoindex cache dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CAMERAS="casio_qv directory spca50x" ELIBC="glibc" INPUT_DEVICES="keyboard mouse joystick evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LINGUAS="en en_GB" USERLAND="GNU" VIDEO_CARDS="nvidia" Unset: CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPT
same issue here
Patches welcome. I don't use --as-needed.
The problem is with the ordering of the libraries. What is asked to the linker is to: link librt (why? there is nothing using it, so it's skipped) move to static linking link libgthread (that needs librt) link librt (now there is need for it and is linked, but we're in static linking mode) return to dynamic linking (implicitly link the C library). The _dl_cpuclock_offset symbol is needed by the static rt library and defined in the static C library, but it's neither needed nor defined in the dynamic versions. This is actually a tricky situation, I guess the easy way out would be to remove the -lrt from the libraries found with libgthread and then append it _after_ returning to dynamic linking. Or finally decide that glib is important for the system and move everything in /lib using dynamic linking ;)
Using the GCC spec to force --as-needed did NOT run into this problem. I last built syslog-ng-2.1.4 on 4/13.
Created attachment 189988 [details] syslog-ng with --as-need linker flag buildlog Hi, I ran into the same trouble !!!
Is this really failing with "forced" --as-needed, as the description says? I thought it only failed with LDFLAGS="-Wl,--as-needed". After all, if it really fails with "forced", then I must have been very lucky when it compiled for me on 4/13. Could someone else please verify this and update the description accordingly?
It fails on my system with LDFLAGS="-Wl,-O1 -Wl,--as-needed" but not if I remove it.
The same happens here (glibc 2.10.1).
My apologies, I forgot to mention that I use GCC 4.4.1... Should this have to be considered as a ld bug and/or be reported ?
I recently emerged world after gcc-4.3.4 was released. Once again, I used Flameeyes' method to generate a forced --as-needed gcc spec file, which is set as my default gcc profile. This resulted in a successful build. I suggest anyone playing with --as-needed to try this method instead of using '-Wl,--as-needed'.
I'll happily take a patch for this but I don't use --as-needed so there's not going to be any progress unless an actual user of that feature steps up. I assume it's still the same with the 3.0.x series?
3.1.1 emerged just fine here with forced asneeded (and also got redudant -Wl,--as-needed in LDFLAGS if that matters, it doesn't) also I can't remember even 2.1.x failing for me, but it's been a while. so far as I know -> fixed by 3.1.1
