warning #3924: attribute namespace "cpp11" is unrecognized

[cb4github]

Getting the following during build.

icpc -std=gnu++14  -I"/share/apps/R/4.1.1-intel/lib64/R/include" -DNDEBUG -I/usr/include/freetype2   -I'/lustre/project/<redacted>/R/Library/cpp11/include' -I/usr/local/include   -fpic  -fPIC -qopenmp -O3 -ipo -xHost -multiple-processes -flto -c caches.cpp -o caches.o
In file included from caches.cpp(1):
caches.h(22): warning #3924: attribute namespace "cpp11" is unrecognized
  [[cpp11::init]]

My gcc version (with intel-mkl):

$ gcc --version
gcc (GCC) 6.3.0

I suspect I'll need to upgrade to gnu++17, true?
Please advise, and please let me know if I can provide more information, thanks.
Best,
CB

[thomasp85]

This seems related to the cpp11 R package, not your compiler... Do you have the latest cpp11 version installed?

[cb4github]

Thanks so much for your response.
Here are my R, icpc, and cpp11 versions.

$ Rscript -e 'cat("R.version.string=", R.version.string, "\n")''
R.version.string= R version 4.1.1 (2021-08-10)
$ icpc --version
icpc (ICC) 19.0.1.144 20181018
$ Rscript -e "packageVersion('cpp11')"
[1] ‘0.4.2’

I've also tried cloning systemfonts and adding a using statement to all my local copies of headers that contain [[cpp11::init]] as in the following but the result is the same "...unrecognized".

diff systemfonts/src/caches.h systemfonts/src/caches.h.bak
8d7
< using namespace cpp11;

Again, please advise, and please let me know if I can provide more information, thanks.

[DavisVaughan]

What OS are you on?

[cb4github]

CentOS 6.5 for now - admittedly EOL - and in Science DMZ. Also, some nodes have been migrated to CentOS 7.4 and have gcc v4.8.5, which supports gnu++11 and not any >= gnu++14 - so no support on the cluster for gnu++17.

Advice welcome, thanks.

[DavisVaughan]

@cb4github could you try installing this cpp11 pull request, and then reinstalling systemfonts?

remotes::install_github("r-lib/cpp11#278")

# Restart R

remotes::install_github("r-lib/systemfonts")

[cb4github]

Please see details below, and thanks @DavisVaughan that those changes certainly did succeed in eliminating the subject icpc compiler warnings #3924, though the need for said changes now arguably seems questionable in light of the ever deepening obsolescence of my current platform.

That said, I'll close the issue and thanks @DavisVaughan and @thomasp85 for all your time and efforts.

Best,
CB

Details:
I had hoped - incorrectly in hindsight - that the subject warnings were the source of the icpc (v19X) compiler (segmentation) error as in the following.

...
icpc -std=gnu++11  -I"/share/apps/R/4.1.1-intel/lib64/R/include" -DNDEBUG -I/usr/include/freetype2   -I'/lustre/project/hpcstaff/cbaribault/R/Library/cpp11/include' -I/usr/local/include   -fpic  -fPIC -qopenmp -O3 -ipo -xHost -multiple-processes -flto -c unix/FontManagerLinux.cpp -o unix/FontManagerLinux.o
": internal error: ** The compiler has encountered an unexpected problem.
** Segmentation violation signal raised. **
Access violation or stack overflow. Please contact Intel Support for assistance.

compilation aborted for font_registry.cpp (code 4)
make: *** [font_registry.o] Error 4
make: *** Waiting for unfinished jobs....
ERROR: compilation failed for package ‘systemfonts’

For reasons that 1) icpc v19XX is no longer maintained and 2) other R packages prerequisite for devtools, etc., are now presenting errors with ld v2.20XX in centos6.5, I've now seen sufficient reason to move to centos 7X and no longer attempt to use R on centos 6 for all reasonable intents and purposes.

If it helps anyone, I was able to install systemfonts using g++ v6.3.0 vice ipcp v19XX using the following local Makevars, including local LDFLAGS with -fopenmp vice my local R-system option -qopenmp.

$ cat ~/.R/Makevars # for installing systemfonts only
CXX=g++
CXX11=g++
CXX14=g++
CXXFLAGS = -fPIC -fopenmp -O3 -flto
CXXPICFLAGS = -fpic
CXX11FLAGS = -fPIC -fopenmp -O3 -flto
CXX11PICFLAGS = -fpic
CXX14FLAGS = -fPIC -fopenmp -O3 -flto
CPPFLAGS+=-I/usr/include/freetype2
LDFLAGS = -fopenmp -L/share/apps/intel_parallel_studio_xe/2019_update1/compilers_and_libraries_2019.1.144/linux/compiler/lib/intel64_lin -L/share/apps/intel_parallel_studio_xe/2019_update1/compilers_and_libraries_2019.1.144/linux/mpi/intel64/lib/release -L/share/apps/pcre2/10.38/lib -L/share/apps/bzip2/1.0.6/lib -L/share/apps/xz/5.2.2/lib

[DavisVaughan]

those changes certainly did succeed in eliminating the subject icpc compiler warnings #3924

Thanks, I'll probably try and get cpp11 updated to avoid this warning in the future then