Re: Linux ppc64 - compatibility-ldbl.o can't find std::num_put

[Alan Modra <amodra at gmail dot com>]

On Mon, Apr 22, 2019 at 12:04:25PM -0400, Brian Groose wrote:
> Everything can be dropped into one directory and fails to link with this
> /PATH/TO/NEWER/G++/g++ -L. -Wl,-z,noexecstack -static-libgcc
> -static-libstdc++ -g *.o -lvirtualization -lagtframework
> -lvirtualization -ldas -loracle -lgeneric -lnas -lsystemstate
> -lstoragemgmt -lsmartcopy -lagtframework -lagentutils -ludplinuxutils
> -ludpzfsutils -lpthread -lrt -Wl,-Bstatic -lACE -lssl -lcrypto -lz
> -lxml2 -lboost_chrono -lboost_filesystem -lboost_locale
> -lboost_program_options -lboost_system -lboost_thread -Wl,-Bdynamic
> -ldl -lrt -lpam -o udsagent

OK, minus the -lpam I can link this and reproduce the problem here.

libboost_locale.a is the culprit.

The first complaint about an undefined symbol (linking with
-Wl,--no-demangle) is
_ZNKSt7num_putIcSt19ostreambuf_iteratorIcSt11char_traitsIcEEE13_M_insert_intIlEES3_S3_RSt8ios_basecT_

This is actually defined in libstdc++.a(locale-inst.o) .opd section
(it's a function descriptor) an alias for
_ZNKSt17__gnu_cxx_ldbl1287num_putIcSt19ostreambuf_iteratorIcSt11char_traitsIcEEE13_M_insert_intIlEES4_S4_RSt8ios_basecT_
with the corresponding code in section
.text._ZNKSt17__gnu_cxx_ldbl1287num_putIcSt19ostreambuf_iteratorIcSt11char_traitsIcEEE13_M_insert_intIlEES4_S4_RSt8ios_basecT_

That section is a member of a comdat group
COMDAT group section [  206] `.group' [_ZNKSt17__gnu_cxx_ldbl1287num_putIcSt19ostreambuf_iteratorIcSt11char_traitsIcEEE13_M_insert_intIlEES4_S4_RSt8ios_basecT_] contains 2 sections:
   [Index]    Name
   [  837]   .text._ZNKSt17__gnu_cxx_ldbl1287num_putIcSt19ostreambuf_iteratorIcSt11char_traitsIcEEE13_M_insert_intIlEES4_S4_RSt8ios_basecT_
   [  838]   .rela.text._ZNKSt17__gnu_cxx_ldbl1287num_putIcSt19ostreambuf_iteratorIcSt11char_traitsIcEEE13_M_insert_intIlEES4_S4_RSt8ios_base

The trouble is, you have another copy of that group in
libboost_locale.a(numeric.o)
COMDAT group section [  139] `.group' [_ZNKSt17__gnu_cxx_ldbl1287num_putIcSt19ostreambuf_iteratorIcSt11char_traitsIcEEE13_M_insert_intIlEES4_S4_RSt8ios_basecT_] contains 2 sections:
   [Index]    Name
   [  535]   .text._ZNKSt17__gnu_cxx_ldbl1287num_putIcSt19ostreambuf_iteratorIcSt11char_traitsIcEEE13_M_insert_intIlEES4_S4_RSt8ios_basecT_
   [  536]   .rela.text._ZNKSt17__gnu_cxx_ldbl1287num_putIcSt19ostreambuf_iteratorIcSt11char_traitsIcEEE13_M_insert_intIlEES4_S4_RSt8ios_base

Only one of these groups gets linked in, the first.  Since you link
libboost_locale.a before libstdc++.a you get the libboost_local.a
version, which doesn't have the alias symbols defined.  I'll note that
object files with different sets of global symbols in comdat groups is
a worry, indicating that your libboost isn't properly compatible with
your libstdc++.

I found it was possible to link the static libstdc++ just before
-lboost_locale without linker complaint (libstdc++.a will be linked
afterwards too).

powerpc64-linux-g++ -L. -Wl,-z,noexecstack -static-libgcc  -static-libstdc++ -g *.o -lvirtualization -lagtframework -lvirtualization -ldas -loracle -lgeneric -lnas -lsystemstate -lstoragemgmt -lsmartcopy -lagtframework -lagentutils -ludplinuxutils -ludpzfsutils -lpthread -lrt -Wl,-Bstatic -lACE -lssl -lcrypto -lz -lxml2 -lboost_chrono -lboost_filesystem -lstdc++ -lboost_locale -lboost_program_options -lboost_system -lboost_thread -Wl,-Bdynamic -ldl -lrt -o udsagent

-- 
Alan Modra
Australia Development Lab, IBM