Re: Building gcc 4.9.2 on AIX 7.1

[David Edelsohn <dje.gcc@gmail.com>]

>>> Randy Galbraith wrote:

> We have a need to match gcc version on Red Hat GNU/Linux 7. I am looking
> forward to newer GCC once Red Hat is upgraded. However, that will likely
> break our build. We elevate every warning in gcc to error status that stops
> the building. Thus we need to plan for that. At the moment I just need to
> support the AIX 7.2 upgrade. Ironically had our port to GNU/Linux been
> completed this would not be an issue. Cheers, -Randy

Red Hat provides newer releases of GCC through the GCC Toolset
package, but that may be limited to RHEL 8.  RHEL 7 is quite old.

Does your AIX 7.2 system have all of the latest Technology Levels
(TLs) and Service Packs (SPs) installed? There have been many
assembler and linker fixes.

If you still have GCC 4.9.2 from the AIX 7.1 system, you should be
able to continue to use it.  You can rebuild the "fixed" headers
without rebuilding the entire compiler.  I don't believe that anyone
has tried bootstrapping GCC with XLC in a very long time.

GCC builds and works with AIX Assembler and AIX Linker.  Until
recently, GNU Assembler and GNU Linker were out of date on AIX 7.x and
produced corrupted object files. The latest GNU Binutils functions.
It might be better to ensure that the AIX tools are used (AIX as, ld,
ar).

GCC 4.9 is very old. I don't have any intuition about why GCC (without
any optimization) would generate unusual code for ferror().  Again, I
would ensure that you are not using the GNU Assembler for your
bootstrap.

Thanks, David