[PATCH] autoconf & warn CFLAGS clean up

[Doug Goldstein]

Michael Biebl wrote:
> 2007/4/25, Doug Goldstein <cardoe at gentoo.org>:
>> So the current usage of checking whether the compiler supports a
>> specific CFLAG kinda sucks because it involves writing out files to /tmp
>> based on the current PID which is less than ideal (insert security
>> conspiracy theories). It's basically an old copy and paste of D-Bus'
>> configure.in
>>
>> Basically I think cairo has a nice way of making it happen so I've
>> basically adapted their solution to HAL and tweaked a little here and
>> there.
>>
>> Along the way I've also enabled a few extra CFLAGS that I tend to use on
>> my own software so you'll notice HAL is a bit noiser when it gets
>> compiled with this patch.
>>
>> The solution essentially uses AC_COMPILE_IFELSE, which is a built in
>> autoconf macro rather then relying on writing a file to /tmp and
>> compiling that.
>>
>> It also makes use of autoconf's caching abilities and if the MAYBE_WARN
>> variable has not had any changes in it, then it will use the cached
>> settings. To force a regen all you need to do is add a white space in
>> there. That should help with developer needs as far as minimizing the
>> length of autoconf runs.
>>
>> I plan on providing patches to clean up some of the new warnings
>> generated by adding these flags.
>>
>> Also any suggestions are welcome.
>
> What about creating a separate m4 macro for this compiler tests/flags,
> putting it into a separate .m4 file, which can then be dropped into
> the (to be created) m4/ directory.
> This way the functionality would be nicely separated and easily
> reusable in other projects, like PK, CK etc. Much better than copy and
> paste. It also wouldn't clutter configure.in.
>
> All you have to do, is to add "ACLOCAL_AMFLAGS = -I m4" to the
> toplevel Makefile.am file.
>
> Cheers,
> Michael
>
>
>
Yeah I'm totally game for that. I actually have this written up as a
macro when I use it in my own projects. The patch I submitted was more
of a status quo with the current configs.