Re: [gentoo-alt] Adventures with Prefix on AIX 5.3

[Perry Smith]

On Dec 14, 2010, at 2:22 AM, Michael Haubenwallner wrote:

> (now with CC-ing list)
>
> On 12/14/10 01:08, Perry Smith wrote:
>>> A Library called 'libmpfr.a' without any version number in plain filename
>>> is calling for troubles[1].
>>>
>>> [1] http://bugs.gentoo.org/show_bug.cgi?id=213277#c11
>>
>> I can recreate this doing:
>>
>> LIBPATH=/lib gcc -o x x.c && ./x
>> exec(): 0509-036 Cannot load program gcc because of the following errors:
>>        0509-022 Cannot load module /gsa/ausgsa/projects/r/ruby/lib/libintl.a(libintl.so.8).
>>        0509-150   Dependent module /lib/libiconv.a(libiconv.so.2) could not be loaded.
>>        0509-152   Member libiconv.so.2 is not found in archive
>
>> I went back and rebuilt my libintl.a using absolute paths so the header looks like:
>
>> 3      /gsa/ausgsa/projects/r/ruby/lib libiconv.a          libiconv.so.2
>>
>> and it still fails.
>
> This is interesting - I've not recognized that LIBPATH overrides absolute path too.

I asked "the higher ups" about this and they asked "do you have another library that referenced libiconv that did not have an absolute path?"  So, I made a simpler test and sure enough, it does work.  So, I have "x" which looks like:

>                         ***Import File Strings***
> INDEX  PATH                          BASE                MEMBER
> 0      /gsa/ausgsa-p9/06/ruby/bin/../lib/gcc/powerpc-ibm-aix5.3.0.0/4.5.0:/gsa/ausgsa-p9/06/ruby/bin/../lib/gcc:/gsa/ausgsa-p9/06/ruby/bin/../lib/gcc/powerpc-ibm-aix5.3.0.0/4.5.0/../../..:/usr/lib:/lib
> 1                                    libc.a              shr.o
> 2      /gsa/ausgsa/projects/r/ruby/lib libintl.a           libintl.so.8


and libintl.so.8 that looks like:

>                         ***Import File Strings***
> INDEX  PATH                          BASE                MEMBER
> 0      /gsa/ausgsa/projects/r/ruby/lib:/gsa/ausgsa-p9/06/ruby/bin/../lib/gcc/powerpc-ibm-aix5.3.0.0/4.5.0:/gsa/ausgsa-p9/06/ruby/bin/../lib/gcc:/gsa/ausgsa-p9/06/ruby/bin/../lib/gcc/powerpc-ibm-aix5.3.0.0/4.5.0/../../..:/usr/lib:/lib
> 1                                    libpthread.a        shr_xpg5.o
> 2                                    libc.a              shr.o
> 3      /gsa/ausgsa/projects/r/ruby/lib libiconv.a          libiconv.so.2


and now I can do:

> LIBPATH=/lib ./x
> hi 4609


x.c is:

> #include <stdio.h>
> #include <libintl.h>
>
> int main(int argc, char *argv[])
> {
>     printf("hi %d\n", libintl_version);
> }


I'm going to continue to explore and see if I can find all the libraries that reference libiconv, fix them, and then see if I can get gcc to work with LIBPATH set to /lib.

On the other topic of using import files, I've had some thoughts that I have not explored yet.  First, I didn't think until today but one import file can reference multiple shared objects.  The reason this is important to me is I believe that being able to do 32 and 64 bit applications is going to be very important to AIX users.  I'm not asking Portage to support it out of the box but I'm also hoping that Portage does not make it next to impossible to implement.

I need to play with this more but my current train of thought is to have one import file.  It could be like:

#! libfoo.X.a(libfoo_32.X.Y.so)
# 32
sym1
sym2
sym3

#! libfoo.X.a(libfoo_64.X.Y.so)
# 64
sym1
sym2
sym3

I have not experimented with any of that yet.  But if that works, then the B, B1, B2, and C options become plausible to me.  Likewise, if my experiments with absolute paths in the library files works, then it seems option A becomes plausible too.