RE: AIX: Symbols are missing in libpq.a

Hi Noah,

Yes, trying to use the create lib$(NAME).exp from $(SHLIB_EXPORTS) when it exists was my first idea, too.
However, I do not master (or I forgot) this kind of "if...." in a Makefile and I was unable to find a solution by reading Makefile manuals or by searching for a similar example. So, I did it in an easier (to me!) and quicker way: merge with a new command line in the Makefile rule.
Now that we have a clear understanding of what is happenning, I may have a deeper look at a clean Makefile solution. However, if you know how to manage this, I would really appreciate some example. I'm asking my colleague too if he can help me here.

Thx

Tony

________________________________
De : Noah Misch <noah(at)leadboat(dot)com>
Envoyé : lundi 30 août 2021 16:52
À : REIX, Tony <tony(dot)reix(at)atos(dot)net>
Cc : pgsql-hackers(at)lists(dot)postgresql(dot)org <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Objet : Re: AIX: Symbols are missing in libpq.a

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On Mon, Aug 30, 2021 at 02:33:32PM +0000, REIX, Tony wrote:
> It appears that the Makefile in src/interfaces/libpq has been modified between v12 and v13, removing encnames.o (and wchar.o) from the object files being used for creating the static libpq.a file which is used for creating the libpq.so and libpq.a AIX shared-library files.
> And, since pg_encoding_to_char() is defined in encnames.o , it has disappeared from the libpq.exp file .
>
> # diff postgresql-12.8/32bit/src/interfaces/libpq/Makefile postgresql-13.1/32bit/src/interfaces/libpq/Makefile | grep encnames
> < OBJS += encnames.o wchar.o
> < encnames.c wchar.c: % : $(backend_src)/utils/mb/%
> < rm -f encnames.c wchar.c
>
> Remember how the final libpq.a is built on AIX:
>
> rm -f libpq.a
> /usr/bin/ar crs libpq.a fe-auth-scram.o ...
> touch libpq.a
> ../../../src/backend/port/aix/mkldexport.sh libpq.a libpq.so.5 >libpq.exp
> /opt/freeware/bin/gcc -maix64 -O3 ..... -o libpq.so.5 libpq.a -Wl,-bE:libpq.exp .......
> rm -f libpq.a
> /usr/bin/ar crs libpq.a libpq.so.5
>
> 12.8 : /usr/bin/ar crs libpq.a fe-auth.o fe-auth-scram.o fe-connect.o fe-exec.o fe-lobj.o fe-misc.o fe-print.o fe-protocol2.o fe-protocol3.o
> pqexpbuffer.o fe-secure.o legacy-pqsignal.o libpq-events.o encnames.o wchar.o fe-secure-openssl.o fe-secure-common.o
>
> 13.1 : /usr/bin/ar crs libpq.a fe-auth.o fe-auth-scram.o fe-connect.o fe-exec.o fe-lobj.o fe-misc.o fe-print.o fe-protocol2.o fe-protocol3.o
> pqexpbuffer.o fe-secure.o legacy-pqsignal.o libpq-events.o fe-secure-common.o fe-secure-openssl.o
>
>
> Maybe you can discover why these changes were made in v13 for src/interfaces/libpq/Makefile .
> And mkldexport.sh , unchanged between v12 and v13, works perfectly.

Thanks; that makes sense. Those files moved to libpgcommon_shlib.a. The
$(MKLDEXPORT) call sees symbols in the .o files, but it doesn't see symbols
pulled in via libpg*.a. Let's fix this by having Makefile.shlib skip
$(MKLDEXPORT) when a $(SHLIB_EXPORTS) file is available and have it instead
create lib$(NAME).exp from $(SHLIB_EXPORTS). That's more correct than
merging, and it's simpler. Would you like to try that?