Re: [PATCH] Detect the default libpath on aix (to fix MPI support!)

[Erik Lindahl]

>
>
> Good job!  Thanks for following this through for us.  I took the liberty of
> renaming and lightly reformatting you new macro, but otherwise applied
> unchanged to HEAD.  I'm not overly keen on the use of awk, except perhaps
> here where the macro targets a particular class of machines (where presumably
> there is guaranteed to be an awk implementation installed).  However, more
> brownie points are available for converting the awk script into sed...
>

Ah, I almost suspected awk was at least a little bad. On the other hand, this
will only
be executed on AIX 4.3 and higher, i.e. fairly modern systems..

I just spend an hour trying to achieve the same result with sed, but no luck.
Perhaps
it's trivial for some of you shell script wizards:

dump -H creates output like this when run on a.out compiled with cc:
---------------------------------------------------------------

a.out:

                        ***Loader Section***
                      Loader Header Information
VERSION#         #SYMtableENT     #RELOCent        LENidSTR
0x00000001       0x00000005       0x0000000d       0x0000001e

#IMPfilID        OFFidSTR         LENstrTBL        OFFstrTBL
0x00000002       0x00000134       0x0000000d       0x00000152


                        ***Import File Strings***
INDEX  PATH                          BASE                MEMBER
0      /usr/lib:/lib
1                                    libc.a              shr.o
-----------------------------------------------------------------

Since the formatting might change, it's probably a good idea to start looking
for
"Import File Strings", and then make sure that the second column two lines
further
down really contains a path (i.e. it starts with "/".) Haven't been able to get
sed
to look two lines further down...

> P.S.  Don't forget to send an entry for the ChangeLog.

OK, try this:

The default AIX libpath is extended with communication libraries when
mpcc wrapper scripts are used to create MPI executables. Instead of
hardcoding /lib and /usr/lib, we now link a program and extract the libpath
from the file, using dump. It should only affect AIX 4.3 and higher.


Cheers,

Erik