[Bug preprocessor/58887] Allow recursion in variadic macros?

[joseph at codesourcery dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58887

--- Comment #7 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
On Sun, 27 Oct 2013, mtewoodbury at gmail dot com wrote:

> That has not always stopped you all in the past, but that is really neither

We have plenty of experience dealing with the consequent problems of the 
old habit of adding extensions because they seemed like a good idea at the 
time (or because a feature was supported in some language other than C, 
and there used to be an idea that GNU C should support all features of 
GCC's internal representation that could be accessed from any language 
supported by GCC) without any real effort in designing them at the level 
of precise proposed standard text to specify the feature.  Based on that 
experience, the bar for new extensions is much higher now.

Unlike recursion, __VA_ARGC__ seems like something reasonably well-defined 
and in accordance with the spirit of the preprocessor and unlikely to be 
problematic as an extension - but as you note, there's already a separate 
bug for it.