Creating a va_list dynamically?

[Bruce Korb]

"Kaveh R. Ghazi" wrote:
> 
> Is it possible to dynamically and portably create a va_list?
> 
> I'm trying to see if I can easily teach gcc to optimize e.g.
> 
>  > fprintf("%d %s", 5, "hello") -> fputs("5 hello")
> 
> What I'd like to do is, at compile time, take the tree structures
> representing 5 and "hello" and dynamically create a va_list out of
> them.  Then I'd pass the format arg and the va_list to vasprintf() and
> emit a call to fputs with the resulting string.
> 
> (If I can't use something like vasprintf, I'd have to rewrite a
> complete *printf parser.  Bleah.)

I went round and round on this one a couple of years ago.
The upshot:  You cannot get there from here (leastwise,
not portably).  The consequence:  Gary V. Vaughan was
extremely generous with his time and got motivated enough
to write the snprintfv library.

You can read about all the motivations here:

  http://autogen.sourceforge.net/doc/autogen_7.html#SEC212

His official distribution directory:

  http://www.oranda.demon.co.uk/dist/

But I think he keeps my CVS archive on SourceForge up to date, too:

  cvs.AutoGen.sourceforge.net:/cvsroot/AutoGen/autogen/snprintfv

> Any info would be appreciated.

:-)