Re: [PATCH v3 10/21] pack-bitmap: add support for bitmap indexes

[Jeff King <peff@peff.net>]

On Mon, Dec 02, 2013 at 12:36:34PM -0800, Junio C Hamano wrote:

> Jeff King <peff@peff.net> writes:
> 
> > I do wonder if at some point we should revisit our "do not use any
> > C99-isms" philosophy. It was very good advice in 2005. I don't know how
> > good it is over 8 years later (it seems like even ancient systems should
> > be able to get gcc compiled as a last resort, but maybe there really are
> > people for whom that is a burden).
> 
> Well, we are not kernel where being able to precisely control
> generated machine code matters and enforcement of acceptable
> compiler versions to achieve that goal is warranted, so I'd prefer
> to avoid anything that tells the users "go get a newer gcc".

Sorry, I was not very clear about what I said. I do not think "go get a
newer gcc" is a good thing to be telling people. But I wonder:

  a. if there are actually people on systems that have pre-c99 compilers
     in 2013

  b. if there are, do they actually _use_ the ancient system compiler,
     and not just install gcc as the first step anyway?

In other words, I am questioning whether we would have to tell anybody
"go install gcc" these days. I'm not sure of the best way to answer that
question, though.

> There are certain things outside C89 that would make our code easier
> to read and maintain (e.g. named member initialization of
> struct/union, cf. ANSI C99 s6.7.9, just to name one) that I would
> love to be able to use in our codebase, but being able to leave an
> extra comma at the list of enums is very low on that list.

Yes, I can live without trailing commas. I was musing more on the
general issue (of course, we don't _have_ to take C99 as a whole, and
can pick and choose features that even pre-C99 compilers got right, but
I was wondering mainly when it would be time to say C99 is "old enough"
that everybody supports it).

-Peff