From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ferruh Yigit Subject: Re: [PATCH] mk: fix underlinking issues of most librte libraries Date: Thu, 26 May 2016 14:13:38 +0100 Message-ID: <5746F682.9070003@intel.com> References: <1463763022-6673-1-git-send-email-christian.ehrhardt@canonical.com> <7920424.umDpp4ukym@xps13> <78bbf74c-9621-9094-a280-76ed9fc88393@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Cc: Thomas Monjalon , dev To: Christian Ehrhardt , Panu Matilainen Return-path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 9D67737A2 for ; Thu, 26 May 2016 15:14:13 +0200 (CEST) In-Reply-To: List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 5/24/2016 11:11 AM, Christian Ehrhardt wrote: > Hi Panu, > I already agreed to Thomas on IRC but won't have time until next week. > Thanks for making a patch that does that already - I'll give it a look = and > some test on my end next week then. >=20 >=20 >=20 > Christian Ehrhardt > Software Engineer, Ubuntu Server > Canonical Ltd >=20 > On Tue, May 24, 2016 at 11:56 AM, Panu Matilainen > wrote: >=20 >> On 05/20/2016 08:08 PM, Thomas Monjalon wrote: >> >>> 2016-05-20 18:50, Christian Ehrhardt: >>> >>>> The individual libraries have various cross dependencies. >>>> This is already refelcted in the DEPDIR dependency, but not yet in >>>> proper DT_NEEDED flags in the .so's. >>>> This adds the -l flags so that is properly stored in the .so's ELF >>>> headers. >>>> >>> >>> Why not filling LDLIBS by parsing DEPDIRS-y in rte.lib.mk? >>> >>> >> A fair question :) The thought has passed my mind too, but I thought i= t'd >> be too messy with differing library vs directory names and other >> exceptions. But in reality manually maintained separate LDLIBS is only >> going to get out of sync sooner or later, and turns out its not that b= ad >> anyway: >> >> diff --git a/mk/rte.lib.mk b/mk/rte.lib.mk >> index b420280..88b4e98 100644 >> --- a/mk/rte.lib.mk >> +++ b/mk/rte.lib.mk >> @@ -77,6 +77,12 @@ else >> _CPU_LDFLAGS :=3D $(CPU_LDFLAGS) >> endif >> >> +# Translate DEPDIRS-y into LDLIBS >> +IGNORE_DEPS =3D -lrte_eal/% -lrte_net -lrte_compat >> +_LDDIRS =3D $(subst librte_ether,libethdev,$(DEPDIRS-y)) >> +_LDDEPS =3D $(subst lib/lib,-l,$(_LDDIRS)) >> +LDLIBS +=3D $(filter-out $(IGNORE_DEPS), $(_LDDEPS)) >> + >> O_TO_A =3D $(AR) crDs $(LIB) $(OBJS-y) >> O_TO_A_STR =3D $(subst ','\'',$(O_TO_A)) #'# fix syntax highlight >> O_TO_A_DISP =3D $(if $(V),"$(O_TO_A_STR)"," AR $(@)") >> >> I'm also sure somebody more familiar with gmake could improve it, but = it >> seems to work quite fine here. I'll wait a bit to see if there are oth= er >> suggestions before sending it as a proper patch. >> >> - Panu - >> I did test the patch with minor diff in rte.vars.mk [1], otherwise all libraries kept needed in final library. Patch itself looks good, overlinking problem in final binary seems fixed [2] [3]. But this cause a compilation error for cmdline_test [4]. This is because of cyclic dependency between librte_eal <-> librte_mempool. Other applications don't have this compilation error because they use librte_mempool, and since it is linked against application, this error not observed. cmdline_test itself doesn't have any direct call to librte_mempool. It is possible to add workaround to cmdline_test [5], (introduce overlinking back), but should we attack on cyclic dependency instead? Thanks, ferruh --- [1] diff --git a/mk/exec-env/linuxapp/rte.vars.mk b/mk/exec-env/linuxapp/rte.vars.mk index d51bd17..10d37d5 100644 --- a/mk/exec-env/linuxapp/rte.vars.mk +++ b/mk/exec-env/linuxapp/rte.vars.mk @@ -46,7 +46,7 @@ EXECENV_CFLAGS =3D -pthread endif # Workaround lack of DT_NEEDED entry -EXECENV_LDFLAGS =3D --no-as-needed +EXECENV_LDFLAGS =3D --as-needed EXECENV_LDLIBS =3D EXECENV_ASFLAGS =3D [2] # ldd build/app/testpmd linux-vdso.so.1 (0x00007ffcff92e000) librte_mbuf.so.2.1 =3D> .../build/lib/librte_mbuf.so.2.1 libethdev.so.4.1 =3D> .../build/lib/libethdev.so.4.1 librte_mempool.so.2.1 =3D> .../build/lib/librte_mempool.so.2.1 librte_ring.so.1.1 =3D> .../build/lib/librte_ring.so.1.1 librte_eal.so.2.1 =3D> .../build/lib/librte_eal.so.2.1 librte_cmdline.so.2.1 =3D> .../build/lib/librte_cmdline.so.2.1 librte_pmd_bond.so.1.1 =3D> .../build/lib/librte_pmd_bond.so.1.1 libpthread.so.0 =3D> /lib64/libpthread.so.0 (0x00007f6879ff1000) libc.so.6 =3D> /lib64/libc.so.6 (0x00007f6879c30000) /lib64/ld-linux-x86-64.so.2 (0x0000564998dbd000) libdl.so.2 =3D> /lib64/libdl.so.2 (0x00007f6879a2c000) libgcc_s.so.1 =3D> /lib64/libgcc_s.so.1 (0x00007f6879814000) librt.so.1 =3D> /lib64/librt.so.1 (0x00007f687960c000) librte_kvargs.so.1.1 =3D> .../build/lib/librte_kvargs.so.1.1 [3] # ldd -u -r build/app/testpmd # [4] =3D=3D Build app/cmdline_test CC cmdline_test.o CC commands.o LD cmdline_test .../build/lib/librte_eal.so: undefined reference to `rte_mempool_lookup' .../build/lib/librte_eal.so: undefined reference to `rte_mempool_create' collect2: error: ld returned 1 exit status .../mk/rte.app.mk:243: recipe for target 'cmdline_test' failed make[3]: *** [cmdline_test] Error 1 [5] diff --git a/app/cmdline_test/Makefile b/app/cmdline_test/Makefile index c6169f5..69ebfb2 100644 --- a/app/cmdline_test/Makefile +++ b/app/cmdline_test/Makefile @@ -46,6 +46,7 @@ SRCS-y +=3D commands.c CFLAGS +=3D -O3 CFLAGS +=3D $(WERROR_FLAGS) +LDFLAGS +=3D --no-as-needed # this application needs libraries first DEPDIRS-y +=3D lib drivers