postfix-devel

[Prev] Thread [Next]  |  [Prev] Date [Next]

Re: [PATCH] detecting epoll Wietse Venema Fri Jun 05 06:00:39 2009

Victor Duchovni:
> On Thu, Jun 04, 2009 at 06:46:45PM +0200, Gerd v. Egidy wrote:
> 
> > Hi Wietse,
> > 
> > > Maybe you can submit a makedefs patch as outlined below. This would
> > > insert four lines with "if-then-else" and one line with "fi".
> > 
> > The attached postfix-2.6.1-epoll-detect.patch implements this.
> > 
> > The downside is that you now require that you include from /usr/include and 
> > not some other path. I'm not that familiar with cross-compiling but I guess 
> > the include-paths differ then.
> 
> If desired, the existence test can be performed via "gcc -E":
> 
>     if printf "#include <sys/epoll.h>\n" | $CC $CCARGS -E - >/dev/null 2>&1
>     then
>       ... proceed as before ...
>     else
>       CCARGS="$CCARGS -DNO_EPOLL"
>     fi
> 
> Presumably, using "$CC $CCARGS -E" is preferable to a literal "gcc -E",
> if the actual compilation will also be using "$CC $CCARGS".

In this context, "$CC" could be any compiler that was specified
on the "make makefiles" command line. I would like to avoid
introducing new assumptions about supported command-line syntax.

As portable alternative for ``printf "text\n"'' I suggest ``echo "text"''.

        Wietse