[R-sig-Debian] Ubuntu 16.10 Yakkety Yak uses GCC 6 but -std=c++98 is missing

[Kirill Müller]

I'm quite happy with -std=c++98 in my /etc/R/Makeconf, but perhaps it's 
unnecessary.

(My previous message isn't in the mailing list archives. Strange.)


-Kirill


On 12.11.2016 14:23, Kirill Müller wrote:
> 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 Müller 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
>>
>
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