R devel - Sep 2021 - Detect UCRT-built R from within R sessions (and in configure.win)

On 9/8/21 2:08 PM, Hiroaki Yutani wrote:
> Hi,
>
> Are there any proper ways to know whether the session is running on
> the R that is built with the UCRT toolchain or not? Checking if the
> encoding is UTF-8 might do the trick, but I'm not sure if it's
always
> reliable.
There in not such a mechanism, yet, but can be added, at least for 
diagnostics.

You are right that checking for UTF-8 encoding would not always be 
reliable. For example, the version of Windows may be too old to allow R 
use UTF-8 as native encoding (e.g. Windows server 2016), then R will use 
the native code page as it does today in the MSVCRT builds.
> Also, I'd like to know if there's any mechanism to detect the UCRT
in
> configure.win. I know there are Makevars.ucrt and Makefile.ucrt, but
> one might want to do some feature test that is specific to the UCRT
> toolchain.
We could add support for configure.ucrt, which would take precedence 
over configure.win on the UCRT builds (like Makevars.ucrt takes 
precedence over Makevars.win). Would that work for you?

Best
Tomas
>
> Best,
> Hiroaki Yutani
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel

Thank you for the prompt reply.
> There in not such a mechanism, yet, but can be added, at least for
> diagnostics.
For example, can R.version somehow contain the information?
> We could add support for configure.ucrt, which would take precedence
> over configure.win on the UCRT builds (like Makevars.ucrt takes
> precedence over Makevars.win). Would that work for you?
Yes, configure.ucrt should work for me. There might be someone who prefers
to switch by some envvar rather than creating another file, but I don't
have a strong opinion here.

Best,
Hiroaki Yutani

2021?9?9?(?) 0:48 Tomas Kalibera <tomas.kalibera at gmail.com>:
>
> On 9/8/21 2:08 PM, Hiroaki Yutani wrote:
> > Hi,
> >
> > Are there any proper ways to know whether the session is running on
> > the R that is built with the UCRT toolchain or not? Checking if the
> > encoding is UTF-8 might do the trick, but I'm not sure if it's
always
> > reliable.
>
> There in not such a mechanism, yet, but can be added, at least for
> diagnostics.
>
> You are right that checking for UTF-8 encoding would not always be
> reliable. For example, the version of Windows may be too old to allow R
> use UTF-8 as native encoding (e.g. Windows server 2016), then R will use
> the native code page as it does today in the MSVCRT builds.
>
> > Also, I'd like to know if there's any mechanism to detect the
UCRT in
> > configure.win. I know there are Makevars.ucrt and Makefile.ucrt, but
> > one might want to do some feature test that is specific to the UCRT
> > toolchain.
>
> We could add support for configure.ucrt, which would take precedence
> over configure.win on the UCRT builds (like Makevars.ucrt takes
> precedence over Makevars.win). Would that work for you?
>
> Best
> Tomas
>
> >
> > Best,
> > Hiroaki Yutani
> >
> > ______________________________________________
> > R-devel at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-devel
>
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