[Bug c/67243] Wrong Message of -Wvla for Standard ISO C90 However Emitted with -std=c11

[manu at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67243

Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-08-16
                 CC|                            |manu at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
It is also useless to give such warning after such error.

I'm afraid the way GCC reports most extensions is very fragile in this way. It
doesn't affect only Wvla. It would be nice to discuss/design/agree on a
canonical and future-proof way to report:

* Pure GNU extensions, not accepted by any standard.
* Features accepted by some standard but that are extensions for other
standards (like C++ style comments).

The latter requires some future-proof way of reporting:

* Extensions that are forbidden up to a particular standard.

* Extensions that were accepted but are forbidden now (not sure if there is
such case at all).

(It is kind of ironic that Clang is fair more clear pointing out when something
is a "GNU extension". In some way, Clang is doing more promotion of GNU than
GCC!)