autotools on aix

[Jim Edwards]

I am trying to port a model to AIX.   The model uses cc cxx and fc
compilers.
The problem is that the IBM xlf compilers do not recognize the -D
preprocessor flag and I am at my wits end trying to
get the tools to do the right thing.

I can handle a conditional edit of the FCFLAGS in configure.in

 FCFLAGS=$(echo $FCFLAGS | sed 's/-D/-WF,-D/g')

but problems hound me.

1.  CPPFLAGS is used in PPFCCOMPILE and LTPPFCCOMPILE  but since CPPFLAGS is
also used for c and cxx I can't substitute that.
2. DEFS= -DHAVE_CONFIG_H is also defined and used in the same places
3. libtool defines  pic_flag=' -DPIC'

Anyone have a good solution?