Horton

Re: static libpq (and other libraries) overwritten on aix

Noah Misch <noah@leadboat.com>

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From: Noah Misch <noah@leadboat.com>
To: Andres Freund <andres@anarazel.de>
Cc: pgsql-hackers@postgresql.org, robertmhaas@gmail.com
Date: 2022-08-18T04:59:29Z
Lists: pgsql-hackers 
The AIX sections of Makefile.shlib misuse the terms "static" and "shared".
Imagine s/static library/library ending in .a/ and s/shared library/library
ending in .so/.  That yields an accurate description of the makefile rules.

On Wed, Aug 17, 2022 at 12:01:54PM -0700, Andres Freund wrote:
> Two questions:
> 1) Do we continue building static libraries for libpq etc?

Essentially, we don't build static libpq today, and we should continue not
building it.  (The first-built libpq.a is static, but that file is an
implementation detail of the makefile rules.  The surviving libpq.a is a
normal AIX shared library.)

> 2) Do we care about static libraries not suriving on AIX?

No.

>    There could also be
>    a race in the buildrules leading to sometimes static libs sometimes shared
>    libs winning, I think.

Not since commit e8564ef, to my knowledge.


Along the lines of Robert's comment, it could be a nice code beautification to
use a different suffix for the short-lived .a file.  Perhaps _so_inputs.a.

I found this useful years ago:
https://web.archive.org/web/20151003130212/http://seriousbirder.com/blogs/aix-shared-and-static-libraries-explained/

Commits

  1. configure: Expand -fvisibility checks to more compilers, test for -qvisibility

  2. aix: No need to use mkldexport when we want to export all symbols

  3. aix: when building with gcc, tell gcc we're building a shared library

  4. aix: Fix SHLIB_EXPORTS reference in VPATH builds

  5. Remove SUBSYS.o rule in common.mk, hasn't been used in a long time

  6. Remove rule to generate postgres.o, not needed for 20+ years

  7. Make the AIX case of Makefile.shlib safe for parallel make.