On Wed, Oct 02, 2013 at 10:18:32AM +0900, Namhyung Kim wrote:
> 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 <jo...@redhat.com>
> >> Cc: Corey Ashford <cjash...@linux.vnet.ibm.com>
> >> Cc: Ingo Molnar <mi...@elte.hu>
> >> Cc: Namhyung Kim <namhy...@kernel.org>
> >> Cc: Paul Mackerras <pau...@samba.org>
> >> Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
> >> Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
> >> Cc: David Ahern <dsah...@gmail.com>
> >> ---
> >> 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 <bfd.h>
>
> 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).
hum, so on my system -liberty check wins without -lbfd,
so 'NO_GTK2=1 NO_LIBPERL=1 NO_LIBPYTHON=1' passes
I need to check Ingo's latest changes on this, not sure how
if this problem is relevant any longer ;-)
jirka
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