R SIG Debian - Nov 2016 - Ubuntu 16.10 Yakkety Yak uses GCC 6 but -std=c++98 is missing

After upgrading to Ubuntu 16.10, which brings GCC 6, I've noticed that 
packages are compiled in C++14 mode by default. Here's what a g++ 
command for compiling one of Rcpp's modules look like on my system:

g++ -I/usr/share/R/include -DNDEBUG -I../inst/include/     -fpic  -g -O2 
-fstack-protector-strong -Wformat -Werror=format-security -Wdate-time 
-D_FORTIFY_SOURCE=2 -g  -c barrier.cpp -o barrier.o

According to GCC news [1], the default is now C++14 if no -std is given. 
R-admin suggests adapting the configuration for GCC 6 [2].

I'm using r-base-core in version 3.3.2-1xenial0 from the Ubuntu repo 
[3]. Please advise.


Best regards

Kirill


[1] https://gcc.gnu.org/gcc-6/changes.html
[2] 
https://cran.r-project.org/doc/manuals/r-release/R-admin.html#C_002b_002b-Support
[3] http://stat.ethz.ch/CRAN/bin/linux/ubuntu

On 11 November 2016 at 23:48, Kirill M?ller wrote:
| After upgrading to Ubuntu 16.10, which brings GCC 6, I've noticed that 
| packages are compiled in C++14 mode by default. Here's what a g++ 
| command for compiling one of Rcpp's modules look like on my system:
| 
| g++ -I/usr/share/R/include -DNDEBUG -I../inst/include/     -fpic  -g -O2 
| -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time 
| -D_FORTIFY_SOURCE=2 -g  -c barrier.cpp -o barrier.o
| 
| According to GCC news [1], the default is now C++14 if no -std is given. 
| R-admin suggests adapting the configuration for GCC 6 [2].
| 
| I'm using r-base-core in version 3.3.2-1xenial0 from the Ubuntu repo 
| [3]. Please advise.

Hm. We had g++-6.* (which does indeed default to C++14) in Debian unstable
for a while now, without problems.

This issue _may_ be fixable by rebuilding r-base-core, but then it would have
been needed for Debian too. Not sure.

This may be an Ubuntu-lagging-Debian issue because we may be rebuilding more
consistently in Debian whereas Ubuntu thinks that R is built with gcc-5 (as
it was) but is now used with gcc-6. Ooops.

You _could_ try idea this by editing /etc/R/Makeconf and inserting the
missing -std=c++-98 for the default CXX builds.

I am still on 16.04 with my machines as I had too much other stuff going on.
Please try a test or two at your end and report back. We should be able to
get this squared.

Dirk

-- 
http://dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org

On 11 November 2016 at 23:48, Kirill M?ller wrote:
| After upgrading to Ubuntu 16.10, which brings GCC 6, I've noticed that 
| packages are compiled in C++14 mode by default. Here's what a g++ 
| command for compiling one of Rcpp's modules look like on my system:
| 
| g++ -I/usr/share/R/include -DNDEBUG -I../inst/include/     -fpic  -g -O2 
| -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time 
| -D_FORTIFY_SOURCE=2 -g  -c barrier.cpp -o barrier.o
| 
| According to GCC news [1], the default is now C++14 if no -std is given. 
| R-admin suggests adapting the configuration for GCC 6 [2].
| 
| I'm using r-base-core in version 3.3.2-1xenial0 from the Ubuntu repo 
| [3]. Please advise.

Hm. We had g++-6.* (which does indeed default to C++14) in Debian unstable
for a while now, without problems.

This issue _may_ be fixable by rebuilding r-base-core, but then it would have
been needed for Debian too. Not sure.

This may be an Ubuntu-lagging-Debian issue because we may be rebuilding more
consistently in Debian whereas Ubuntu thinks that R is built with gcc-5 (as
it was) but is now used with gcc-6. Ooops.

You _could_ try idea this by editing /etc/R/Makeconf and inserting the
missing -std=c++-98 for the default CXX builds.

I am still on 16.04 with my machines as I had too much other stuff going on.
Please try a test or two at your end and report back. We should be able to
get this squared.

Dirk

-- 
http://dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org

Thanks. I have now CXX = g++ -std=c++98 in my /etc/R/Makeconf, it's 
picked up properly. I can only assume that the last -std= option wins if 
more than one are given on the same command line [1].


-Kirill


[1] http://stackoverflow.com/q/40563269/946850



On 12.11.2016 03:01, Dirk Eddelbuettel wrote:
> On 11 November 2016 at 23:48, Kirill M?ller wrote:
> | After upgrading to Ubuntu 16.10, which brings GCC 6, I've noticed
that
> | packages are compiled in C++14 mode by default. Here's what a g++
> | command for compiling one of Rcpp's modules look like on my system:
> |
> | g++ -I/usr/share/R/include -DNDEBUG -I../inst/include/     -fpic  -g -O2
> | -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time
> | -D_FORTIFY_SOURCE=2 -g  -c barrier.cpp -o barrier.o
> |
> | According to GCC news [1], the default is now C++14 if no -std is given.
> | R-admin suggests adapting the configuration for GCC 6 [2].
> |
> | I'm using r-base-core in version 3.3.2-1xenial0 from the Ubuntu repo
> | [3]. Please advise.
>
> Hm. We had g++-6.* (which does indeed default to C++14) in Debian unstable
> for a while now, without problems.
>
> This issue _may_ be fixable by rebuilding r-base-core, but then it would
have
> been needed for Debian too. Not sure.
>
> This may be an Ubuntu-lagging-Debian issue because we may be rebuilding
more
> consistently in Debian whereas Ubuntu thinks that R is built with gcc-5 (as
> it was) but is now used with gcc-6. Ooops.
>
> You _could_ try idea this by editing /etc/R/Makeconf and inserting the
> missing -std=c++-98 for the default CXX builds.
>
> I am still on 16.04 with my machines as I had too much other stuff going
on.
> Please try a test or two at your end and report back. We should be able to
> get this squared.
>
> Dirk
>