From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752482Ab3JBBSg (ORCPT ); Tue, 1 Oct 2013 21:18:36 -0400 Received: from LGEMRELSE1Q.lge.com ([156.147.1.111]:61968 "EHLO LGEMRELSE1Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752180Ab3JBBSe convert rfc822-to-8bit (ORCPT ); Tue, 1 Oct 2013 21:18:34 -0400 X-AuditID: 9c93016f-b7bc8ae000004e6e-66-524b7468af0c From: Namhyung Kim To: Jiri Olsa Cc: linux-kernel@vger.kernel.org, Corey Ashford , Ingo Molnar , Paul Mackerras , Peter Zijlstra , Arnaldo Carvalho de Melo , David Ahern Subject: Re: [PATCH 1/3] perf tools: Separate lbfd check out of NO_DEMANGLE condition References: <1380221754-29865-1-git-send-email-jolsa@redhat.com> <1380292332-6518-1-git-send-email-jolsa@redhat.com> <1380437526.1727.10.camel@leonhard> Date: Wed, 02 Oct 2013 10:18:32 +0900 In-Reply-To: <1380437526.1727.10.camel@leonhard> (Namhyung Kim's message of "Sun, 29 Sep 2013 15:52:06 +0900") Message-ID: <87d2noo4gn.fsf@sejong.aot.lge.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jiri, On Sun, 29 Sep 2013 15:52:06 +0900, Namhyung Kim wrote: > Hi Jiri, > > 2013-09-27 (금), 16:32 +0200, Jiri Olsa: >> We fail build with NO_DEMANGLE with missing -lbfd externals error. >> The reason is that we now use bfd code in srcline object: >> perf tools: Implement addr2line directly using libbfd >> >> So we need to check/add -lbfd always now. >> >> Signed-off-by: Jiri Olsa >> Cc: Corey Ashford >> Cc: Ingo Molnar >> Cc: Namhyung Kim >> Cc: Paul Mackerras >> Cc: Peter Zijlstra >> Cc: Arnaldo Carvalho de Melo >> Cc: David Ahern >> --- >> tools/perf/config/Makefile | 17 ++++++++--------- >> 1 file changed, 8 insertions(+), 9 deletions(-) >> >> diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile >> index 8b49a00..40a41c6 100644 >> --- a/tools/perf/config/Makefile >> +++ b/tools/perf/config/Makefile >> @@ -360,6 +360,13 @@ else >> endif >> endif >> >> +FLAGS_BFD=$(CFLAGS) $(LDFLAGS) $(EXTLIBS) -DPACKAGE='perf' -lbfd >> +has_bfd := $(call try-cc,$(SOURCE_BFD),$(FLAGS_BFD),libbfd) >> +ifeq ($(has_bfd),y) >> + EXTLIBS += -lbfd >> + CFLAGS += -DLIBBFD_SUPPORT >> +endif >> + >> ifdef NO_DEMANGLE >> CFLAGS += -DNO_DEMANGLE >> else >> @@ -367,11 +374,7 @@ else >> EXTLIBS += -liberty >> CFLAGS += -DHAVE_CPLUS_DEMANGLE >> else >> - FLAGS_BFD=$(CFLAGS) $(LDFLAGS) $(EXTLIBS) -DPACKAGE='perf' -lbfd >> - has_bfd := $(call try-cc,$(SOURCE_BFD),$(FLAGS_BFD),libbfd) >> - ifeq ($(has_bfd),y) >> - EXTLIBS += -lbfd >> - else >> + ifneq ($(has_bfd),y) >> FLAGS_BFD_IBERTY=$(FLAGS_BFD) -liberty >> has_bfd_iberty := $(call try-cc,$(SOURCE_BFD),$(FLAGS_BFD_IBERTY),liberty) >> ifeq ($(has_bfd_iberty),y) >> @@ -397,10 +400,6 @@ else >> endif >> endif >> >> -ifndef ($(filter -lbfd,$(EXTLIBS)),) >> - CFLAGS += -DLIBBFD_SUPPORT >> -endif >> - >> ifndef NO_STRLCPY >> ifeq ($(call try-cc,$(SOURCE_STRLCPY),,-DHAVE_STRLCPY),y) >> CFLAGS += -DHAVE_STRLCPY > > Is it enough to check on -lbfd only? I guess libbfd can have additional > dependencies to libiberty and libz. If so, this patch can fail to set > -DLIBBFD_SUPPORT, right? I tested this on my system. At first I guessed (without testing) it cannot build SOURCE_BFD with -lbfd only due to additional -liberty and -lz dependency, but it's not. Actually the libfd.so is a plain text file which contains linker script like this: $ file /lib64/libbfd.so /lib64/libbfd.so: ASCII text $ cat /lib64/libbfd.so /* GNU ld script */ /* Ensure this .so library will not be used by a link for a different format on a multi-architecture system. */ OUTPUT_FORMAT(elf64-x86-64) /* The libz dependency is unexpected by legacy build scripts. */ INPUT ( /usr/lib64/libbfd.a -liberty -lz ) So it should handle external dependencies. But it doesn't. $ cat bfd.c #include int main(void) { bfd_demangle(0, 0, 0); return 0; } namhyung@sejong:tmp$ gcc bfd.c -lbfd /usr/lib64/libbfd.a(plugin.o): In function `try_load_plugin': (.text+0x1ab): undefined reference to `dlopen' /usr/lib64/libbfd.a(plugin.o): In function `try_load_plugin': (.text+0x1ca): undefined reference to `dlsym' /usr/lib64/libbfd.a(plugin.o): In function `try_load_plugin': (.text+0x263): undefined reference to `dlerror' collect2: error: ld returned 1 exit status It seems that it needs libdl for loading plugins. Adding -ldl makes above build successfully. So we need to add -ldl for EXTLIBS IMHO. Without it, make NO_GTK2=1 NO_LIBPERL=1 NO_LIBPYTHON=1 will fail to check libbfd correctly (FYI, libperl and libpython add -ldl to the dependency list). Thanks, Namhyung