[PATCH v2] Support %m in printf functions

Jeff Johnston jjohnstn@redhat.com
Mon Jan 9 21:14:00 GMT 2012

On 01/09/2012 06:51 AM, Corinna Vinschen wrote:
> On Jan  6 01:00, Yaakov (Cygwin/X) wrote:
>> On Sun, 2012-01-01 at 11:59 -0600, Yaakov (Cygwin/X) wrote:
>>> This patch adds support for the "%m" conversion specifier in the printf
>>> and wprintf functions, a GNU extension:
>>> http://www.kernel.org/doc/man-pages/online/pages/man3/printf.3.html
>> Thank you all for the comments.  The attached revised patch and STC
>> should take them into account.
>> The remaining issue is that of gating, specifically exactly how to do
>> so.  For the moment I'm using __CYGWIN__ until some agreement can be
>> reached.
> Jeff, I'd like to get your input on this.
> IMHO, it doesn't feel right to add __CYGWIN__ here since the %m
> functionality is sufficiently target agnostic to be useful for everyone
> who would like to use it.  I guess _GLIBC_EXTENSION sounds about right,
> but maybe it should be _NO_GLIBC_EXTENSIONS instead and only set it
> for builds which explicitely don't want them?

Agreed regarding the CYGWIN usage.  It is documented as a GNU extension 
in glibc.

My tendency is to preserve things as-is when something optional is 
introduced.  Thus, a platform that has severe space constraints isn't 
forced to adopt a new feature their users don't use or need that may add 
to the module size.

So, in this case, I would recommend that a platform needs to explicitly 
specify the desire to add _GLIBC_EXTENSIONS.

-- Jeff J.

> Corinna

More information about the Newlib mailing list