Re: A macro to check for data type alignment

[Akim Demaille]

| Since you asked for contribution of specific macros, I have picked out a
| few macros from our project that could be of general applicability.  I'll
| just show you the macro right now; if you want to have it I'll supply a
| real patch and documentation updates.
| 
| Here is a macro that checks whether the gettimeofday() function takes only
| 1 argument (normal is 2, the second argument is the time zone).  This is
| the case on some SVR4 systems.  If this is found to be the case, the macro
| inserts of definition
| 
| #define gettimeofday(a,b) gettimeofday(a)
| 
| into config.h.  Thus gettimezone can be used consistently throughout the
| code without changes.  (The use of the second argument is obsolete on
| modern systems, so there are not real problems to be expected from
| ignoring it.)

Thanks for the contribution!

I'm somewhat against using AC_DEFINE to replace functions (but until
we can provide more convenient, I'll just shut up 1:), and against
AC_FUNC which replaces without saying.  Please, submit an
AC_REPLACE_FUNC_GETTIMEOFDAY.

Since there appears to be some debate about it, I'd like Paul's
insight on this function.  In particular, I shall repeat I don't like
AC_DEFINE here.  It seems to me that AC_REPLACE_FUNC is appropriate
here, with a real implementation of the POSIX guy.