Tom Lane wrote:
>>> I think there's a reasonable argument that by installing
>>> a .a file that isn't a shared library, we are violating
>>> the platform's conventions.
>
> Hm. This seems possible with some moderate hacking on Makefile.shlib
> (certainly it'd be no more invasive than the existing Windows-specific
> platform variants). [...]
>
> Another issue with installing only .a is that there's no provision
> for versioning in .a library names ... what happens to someone who
> needs two generations of libpq on his machine?
Ok, I have spent some time researching and thinking, and I
have three proposals how to deal with linking on AIX.
1) Leave everything as it is and add the LDAP libraries to the AIX hack in Makefile.shlib.
Pros:
- Little work.
Cons:
- PostgreSQL will continue to be statically linked on AIX (unless somebody feeds configure the right LDFLAGS).
2) Remove the AIX hack from Makefile.shlib, add -brtl and -blibpath:"$(rpathdir)":*-L directories in
LDPATH*:/usr/lib:/lib(this sets the AIX equivalent for RPATH) to LDFLAGS for AIX.
Pros:
- Dynamic linking on AIX.
- The organization of the libraries (libpq.a static, libpq.so dynamic) is similar to other operating systems.
Cons:
- The library organization is counter-intuitive to AIX people, and most people will inadvertedly link statically when
linkingagainst libpq.
- According to Rocco Altier it will not work on historic versions of AIX (no -brtl flag).
3) Major hacking in Makefile.shlib to achieve the following: - libXX.so.n is built from libXX.a in the traditional
way. Then libXX.a is deleted, and recreated as archive containing libXX.so.n. - Linking takes place withOUT
-brtl,but with -blibpath:... as in 2). - When the shared libs are installed, I see two options: a) copy (and
overwrite)libXX.a to libdir, do not install libXX.so.n b) Look for existing libXX.a in libdir, extract all
libXX.so.k from it, mark them LOADONLY with 'strip -e libXX.so.k', create a new libXX.a with these objects
andthe new libXX.so.n
Pros:
- Dynamic linking on AIX.
- AIX-conforming organization of libraries.
- In the case of 3)b), multiple versions of the library can be retained in the same archive. Linking is only possible
withthe latest versions, but old programs continue to work.
- 3)a) will probably work on older versions of AIX (I hope there's a -blibpath flag).
Cons:
- Much work, particularly with 3)b).
- Library organization on AIX will be different from other platforms.
- 3)b) will probably not work on old versions of AIX (I read a posting that makes me believe that 'strip -e' was not
aroundbefore 4.3.3.
I am willing to implement whatever solution we decide upon.
I personally would prefer 3)a), but am happy with anything
except 1).
Yours,
Laurenz Albe
I personally would prefer 3)a)