[Bug-gsl] Another hint for AIX with gcc. Set CFLAGS="-g0"

[Dr. David Kirkby]

I know the INSTALL file has some hints for AIX, but I could suggest another 
which might be useful to those building GSL with gcc.

You may recall I posted a patch some time ago for AIX which checked if fprnd_t 
was declared, and if not set declared it appropriately. Those changes to 
configure.ac and fp-aix.c have been committed to the development of GSL.

However, I noted that GSL still did not build, but failed with an error like:

ld: 0711-593 SEVERE ERROR: Symbol C_BSTAT (entry 635) in object siman_tsp.o:
        The symbol refers to a csect with symbol number 0, which was not
        found. The new symbol cannot be associated with a csect and
        is being ignored.

I now have a better idea what this is and how to work around it.

The problem is caused by variables that are declared static, but are not 
initialized. It's been discussed on the AIX forums and the gcc bug database. It 
affects lots of bits of software  - GNU patch being one of them. But anything 
that has static variables that are not initialised.

http://www.ibm.com/developerworks/forums/thread.jspa?threadID=348558
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46072

It appears that some updates to AIX have triggered this, though I'm not exactly 
sure what patches have to be applied for the error to occur.

Whether its a bug in the IBM assembler, the IBM linker or gcc is anyones guess. 
But a workaround is to build without debugging information.

So set

CFLAGS="-g0"

and then build GSL. The "-g0" will override the "-g" which gets put 
automatically put there by the configure script. The GSL builds fine.

For the record, the system where I've built GSL on AIX is:

* IBM RS/6000 7025/F50
* AIX 5.3 with Maintenenace Level 12, service pack 2
(this is quite critical, as I suspect a vanilla 5.3 will be ok)
 * gcc 4.2.4 from 'pware', configured as:

-bash-4.1$ gcc -v
Using built-in specs.
Target: powerpc-ibm-aix5.3.0.0
Configured with: ../stage/gcc-4.2.4/configure --disable-shared 
--enable-threads=posix --prefix=/opt/pware --with-long-double-128 
--with-mpfr=/opt/pware --with-gmp=/opt/pware
Thread model: aix
gcc version 4.2.4

Dave