automated sizeof usage?

automated sizeof usage?

[Randy.Dunlap]

Hi,

Is there an (automated) way to determine struct sizes...
without resorting to writing a dummy program that includes all
interesting structs and printing the sizeof each one of them?

I was wondering about something like this:

#ifdef WARN_SIZES
#warning szof struct v4l2_framebuffer: sizeof(struct v4l2_framebuffer)
#endif

but that just prints the literal string, i.e., it doesn't evaluate
the sizeof(...).  Is there a way to evaluate and print that during
a compilation?  Maybe #warning is done in a pass that is too early
to know the struct size.  Is there a good way to do this?

Thanks,
--
~Randy

Re: automated sizeof usage?

[Alexandre Oliva]

On Mar  4, 2003, "Randy.Dunlap" <rddunlap@osdl.org> wrote:

> Is there an (automated) way to determine struct sizes...

You may want to have a look at autoconf 2.5x's AC_CHECK_SIZEOF macro
for inspiration.

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                 aoliva@{redhat.com, gcc.gnu.org}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist                Professional serial bug killer