Modern C Compiler, ROOT, Geant
Introduction
So you want a modern C compiler and/or some other tool. As of this writing (2 November 2016) the normal desktop machines have
gcc version 4.4.7 20120313 (Red Hat 4.4.7-17) (GCC)
as the default compiler. This is not recent enough for much of the HEP code ecosystem.
Modern C compilers can be found in a repository called "SFT" which is maintained by CERN, and distributed via something called CVMFS which is installed on stoomboot machines and most of the desktop machines (older ones may not have it). You can check whether you have it with:
ls /cvmfs/sft.cern.ch
if you don't get an error (and it says "lcg") then you're good. What you'll need to do to set up the compiler is:
- figure out what kind of platform you'll be running on
- poke around in SFT to find out what the current release is
- run the setup script
- compile your code and win the Nobel Prize.
Figure out your platform
You'll generally need to compile for a specific platform; go (one of) the machine(s) on which you'll be running your code and type
cat /etc/issue
Today on one of the stoomboot worker nodes, it says
Scientific Linux CERN SLC release 6.8 (Carbon) Kernel \r on an \m
Remember that first line, that tells you the platform, you'll need it shortly.
Poke around in SFT and find the relevant release and compiler
stbc-i2:~> cd /cvmfs/sft.cern.ch/lcg/releases stbc-i2:releases> ls -d LCG_* LCG_71 LCG_81c LCG_82rootaas4 LCG_84swan3 LCG_86 LCG_71root6 LCG_81d LCG_82rootaas5 LCG_84swan4 LCG_87 LCG_72a LCG_81e LCG_82rootaas6 LCG_85 LCG_latest LCG_75root6 LCG_81f LCG_83 LCG_85a LCG_rootext20161010 LCG_78root6 LCG_82 LCG_84 LCG_85b LCG_rootext20161129 LCG_79 LCG_82rootaas1 LCG_84a LCG_85swan1 LCG_80 LCG_82rootaas2 LCG_84swan1 LCG_85swan2 LCG_81b LCG_82rootaas3 LCG_84swan2 LCG_85swan3
Note the LCG87 is the highest number ... this is generally the latest full release. Take a look at this page for some documentation on what the various releases include.
Note I've replaced below, "LCG_87" with "LCG_XXX" in commands to help avoid mistakes made via blind copy-and-pasting. Change the XXX to whatever you find the most recent release to be!
stbc-022:releases> cd /cvmfs/sft.cern.ch/lcg/releases/LCG_XXX stbc-i2:LCG_XXX> ls 4suite gmp LCG_externals_x86_64-ubuntu1604-gcc54-dbg.txt pacparser requests AIDA gperftools LCG_externals_x86_64-ubuntu1604-gcc54-opt.txt pandas ROOT astroid graphviz LCG_generators_x86_64-centos7-gcc62-dbg.txt pathlib2 root_numpy autoconf Grid LCG_generators_x86_64-centos7-gcc62-opt.txt pathos rootpy automake GSL LCG_generators_x86_64-slc6-gcc49-dbg.txt pcre rpy2 backports gtest LCG_generators_x86_64-slc6-gcc49-opt.txt pexpect scikitlearn blas hadoop LCG_generators_x86_64-slc6-gcc62-dbg.txt pickleshare scipy Boost hepdata_converter LCG_generators_x86_64-slc6-gcc62-opt.txt pip setuptools castor hepdata_validator LCG_generators_x86_64-ubuntu1604-gcc54-dbg.txt pkg_config simplegeneric ccache HepMC LCG_generators_x86_64-ubuntu1604-gcc54-opt.txt pox simplejson certifi HepPDT lcov ppft singledispatch clhep hive lhapdfsets prettytable sip CMake igprof libaio processing six cmaketools ipykernel libgit2 prompt_toolkit sollya cmmnbuild ipython libsvm protobuf soqt cmt ipython_genutils libtool psutil spark coin3d ipywidgets libunwind ptyprocess sqlalchemy configparser java libxml2 py sqlite COOL jemalloc libxslt py2neo stomppy CORAL Jinja2 logilabcommon py4j storm CouchDB joblib lxml pyanalysis subprocess32 coverage jpype m4 pyapigitlab swig cppgsl jsonc MarkupSafe pydot sympy CppUnit jsoncpp matplotlib pydot_ng tbb curl jsonschema maven pygments terminado cx_oracle jupyter MCGenerators pygraphics theano cycler jupyter_client messaging pygsi tornado cython jupyter_console metakernel pylint traitlets Davix jupyter_contrib_core mistune pyminuit urllib3 DD4hep jupyter_contrib_nbextensions mock pyparsing uuid decorator jupyter_core mpfi pyqt valgrind dill jupyter_nbextensions_configurator mpfr pyqt5 vdt distribute keras mpich2 pytest VecGeom doxygen lapack multiprocess Python vectorclass eigen LCGCMT multiprocessing python_dateutil wcwidth elasticsearch LCG_contrib_x86_64-centos7-gcc62-dbg.txt mysql python_gitlab wheel entrypoints LCG_contrib_x86_64-centos7-gcc62-opt.txt mysql_python pytimber widgetsnbextension expat LCG_contrib_x86_64-slc6-gcc49-dbg.txt nbconvert pytools xapian fastjet LCG_contrib_x86_64-slc6-gcc49-opt.txt nbformat pytz XercesC fftw3 LCG_contrib_x86_64-slc6-gcc62-dbg.txt networkx pyxml xqilla fjcontrib LCG_contrib_x86_64-slc6-gcc62-opt.txt neurobayes pyyaml xrootd fplll LCG_contrib_x86_64-ubuntu1604-gcc54-dbg.txt neurobayes_expert pyzmq xrootd_python freetype LCG_contrib_x86_64-ubuntu1604-gcc54-opt.txt ninja QMtest xz frontier_client lcgenv nose qt yamlcpp ftjam LCG_externals_x86_64-centos7-gcc62-dbg.txt notebook qt5 zeromq future LCG_externals_x86_64-centos7-gcc62-opt.txt numexpr qtconsole zlib futures LCG_externals_x86_64-slc6-gcc49-dbg.txt numpy qwt gcc LCG_externals_x86_64-slc6-gcc49-opt.txt omniorb R Geant4 LCG_externals_x86_64-slc6-gcc62-dbg.txt openssl rangev3 genshi LCG_externals_x86_64-slc6-gcc62-opt.txt oracle RELAX
There is a lot of stuff in here that might be interesting to you (eg ROOT and Geant4). See that gcc is also listed, list that directory to see the options:
stbc-i2:LCG_87> ls gcc 4.9.1 4.9.3 6.2.0 stbc-i2:LCG_87> ls gcc/4.9.3 x86_64-slc6
So gcc 4.9.3 is there, along with two other versions. Now the /etc/issue business above becomes relevant: it said "Scientific Linux CERN SLC release 6.8" which corresponds to the "slc6" here, so this one will work for you:
stbc-i2:LCG_87> ls gcc/4.9.3/x86_64-slc6 bin include lib lib64 libexec setup.csh setup.csh~ setup.sh setup.sh~ share
Run the setup script
You want that setup.sh file ..
source /cvmfs/sft.cern.ch/lcg/releases/LCG_XXX/gcc/X.Y.Z/x86_64-platform/setup.sh
Change XXX to the right LCG release tag, X.Y.Z to the right gcc version you found, and "platform" to the right platform you found.
note: csh users need the setup.csh file We (PDP) assume that the csh setup works correctly, none of us use csh, hence we don't know for sure ;-)
Compile your code
Now you'll have the right stuff in your path, etc to use this version of gcc:
stbc-022:x86_64-slc6> gcc --version gcc (GCC) 4.9.3 Copyright (C) 2015 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. stbc-022:x86_64-slc6> g++ --version g++ (GCC) 4.9.3 Copyright (C) 2015 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Enjoy that prize. Don't forget to mention the PDP group in your speech.
