RE: AC_PROG_CC_C99 and -std=c99

[Bob Friesenhahn]

On Mon, 18 Jun 2012, 'Chris Hall' wrote:
> I'm sorry, but I don't understand: if some interface is not supported
> by the standard, I don't want it... because if I use something outside
> the standard I cannot reasonably expect some other c99 compiler to
> support it.  Surely ?
>
> I try to be reasonably conservative and I wouldn't have much sympathy
> with a compiler that doesn't cover the c99 things I do use.

It is true that useful programs can be written using nothing more than 
ANSI C interfaces (e.g. stdio).  Most programs want to use more than 
that though.  For example, they may want to use POSIX standard 
interfaces which are not included in the ANSI C specification.

The problem is that there is only one control knob being exposed.  I 
assume that you want to block GNU C compiler specific language 
features while being able to use more than ANSI C interfaces.  This 
would require more than one control knob.

Bob
--
Bob Friesenhahn
address@hidden, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/