I had, as an experiment tried xlC and a LDFLAG I had been using for php builds (-blibpath:xxx) was not accepted as an argument. I'll try xlc and xlc_r and see if I can spot differences.

On Wed, Oct 7, 2009 at 4:34 PM, Jeff Trawick <trawick@gmail.com> wrote:
On Wed, Oct 7, 2009 at 10:27 AM, Michael Felt <mamfelt@gmail.com> wrote:
> You sound much better versed than I. However, next week when I am back I'll
> go thru my "obscure" and see if I can find anything to help me understand.
> Someone in IBM probably had a reason for being different (i.e. COFF versus
> ELF). I just hope to understand it well enough to be able to be able to get
> builds to build easily.

(butting in; I was once versed enough)

COFF vs. ELF doesn't matter

statically resolving all symbols vs. dynamically resolving symbols
does matter for some code (e.g., mod_perl for Apache); thus, -brtl is
important; APR's apr_hints.m4 adds it to LDFLAGS for modern AIX

IIRC, when libtool sees -brtl it names shared libraries .so instead of .a

> Would you care to comment on a preference for CC definition when using XL
> compilers. I am leaning towards xlc.

CC=xlc_r gets you the appropriate reentrant flags