Re: inetutils 1.9.5 rc1 on AIX

[Mats Erik Andersson]

> On AIX 7.2, in 32-bit mode, with the xlc compiler, there are
>   - many compilation errors,
>   - a link error in the talkd directory (could be fixed by linking with
>     -lpthread). These missing symbols come from mbrtowc.o, regex.o.
>     According to the gnulib module descriptions of 'mbrtowc' and 'regex',
>     you need to link with $(LIB_MBRTOWC) $(LIBTHREAD).
>     $(LIBTHREAD) in fact expands to '-lpthread'.

These matters surfaced already in

  https://list.gnu.org/archive/html/bug-inetutils/2015-08/msg00005.html

but never saw any reply. Today I managed to find the Technical Reference
SC23-2300-01 for AIX PS/2, dating back to 1991.

In section 1.2.22.2 `Porting BSD4.3 Applications to AIX', the key message is

   * Compile with macro _BSD defined,

   * Link to /usr/lib/libbsd.a

in order to achieve capabilities conforming to BSD4.3. The contrary case
require the defined macro _AIX.

Section 1.2.22 `BSD4.3 library' states that

    Standard C library (libc.a)
    Math library (libm.a)
    BSD Compatibility (libbsd.a)

are available, but that some functions like signal() and sigvec() conform
to AIX in libc, while they conform to BSD4.3 in libbsd. At the moment
I hesitate about where linking with libbsd is best implemented by me,
since I have no way of testing the outcome. Of course I implement _BSD
in configure.ac.

The incomplete linking for Gnulib module `regex' is resolved already.

Best regards for now,
  Mats E A