[PATCH v2] Support %m in printf functions

Ralf Corsepius ralf.corsepius@rtems.org
Tue Jan 10 06:40:00 GMT 2012

On 01/09/2012 10:13 PM, Jeff Johnston wrote:
> 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.

ACK. For RTEMS, we definitely want %m to be off by default.


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