Re: A question about c-parse.y

[James E Wilson <wilson at specifixinc dot com>]

Simos Kordas wrote:
> I have succesfully created a C parser (with the
> functionality i described) using bison and a ISO-C
> grammar found in Internet, but it does not work with
> linux kernel sources.

You will have to extend the parser to support the GNU C extensions used 
in the linux kernel.  The attribute syntax and the extended asms syntax 
probably gets you most of the way there.  These are documented in the 
gcc manual.

> Now i try to use the grammar
> from gcc (c-parse.y), but i have problems "cleaning it
> up".

The GCC grammer is not designed to be used outside gcc, and we likely 
aren't interested in changes that would make this so, unless they 
significantly help gcc somehow.  It is probably better to instrument gcc 
somehow so that it dumps the info you want.

Note also that since gcc is GPLed, if you borrow code from gcc, then the 
GPL covers your application.  Depending on what you are writing, this 
may or may not be acceptable.

> grammar included in c-parse.y? Is there an other
> alternative way to get the function names (except
> -aux-info) without creating object files?

What is wrong with the -aux-info output?  It seems to have the info you 
are looking for.  If you want the info in a slightly different form, you 
could hack up gcc to emit exactly what you want.

You could try looking elsewhere for a grammar.  The GNU C extensions are 
widely known and widely copied, so you may be able to find a stand alone 
C grammar that already includes support for the GNU C extensions.
--
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com