multiple versions of gcc...

trist007 · 07-07-2016, 03:25 AM

I run CentOS 6.8 which has gcc 4.4. I want C++14 functionality so I installed another version of gcc2 to /usr/local/gcc2.

So I use /usr/local/bin/g++ which is symlinked from /usr/local/gcc2/bin/g++.

I tried using std::move which I understood was C++11. However, I get this.

Code:

rgonzale@darkstar:~1039 g++ -std=c++11 move.cpp 
rgonzale@darkstar:~1040 ./a.out
./a.out: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.14' not found (required by ./a.out)

I see that g++ is grabbing libstdc++ from /usr/lib64.

Code:

rgonzale@darkstar:~1050 strings /usr/local/gcc2/lib64/libstdc++.so | grep GLIBC
GLIBCXX_3.4
GLIBCXX_3.4.1
GLIBCXX_3.4.2
GLIBCXX_3.4.3
GLIBCXX_3.4.4
GLIBCXX_3.4.5
GLIBCXX_3.4.6
GLIBCXX_3.4.7
GLIBCXX_3.4.8
GLIBCXX_3.4.9
GLIBCXX_3.4.10
GLIBCXX_3.4.11
GLIBCXX_3.4.12
GLIBCXX_3.4.13
GLIBCXX_3.4.14
GLIBCXX_3.4.15
GLIBCXX_3.4.16
GLIBCXX_3.4.17
GLIBCXX_3.4.18
GLIBCXX_3.4.19
GLIBCXX_3.4.20
GLIBC_2.3
GLIBC_2.2.5
GLIBC_2.3.2
GLIBCXX_FORCE_NEW
GLIBCXX_DEBUG_MESSAGE_LENGTH
rgonzale@darkstar:~1051 strings /usr/lib64/libstdc++.so | grep GLIBC
strings: '/usr/lib64/libstdc++.so': No such file
rgonzale@darkstar:~1052 strings /usr/lib64/libstdc++.so.6 | grep GLIBC
GLIBCXX_3.4
GLIBCXX_3.4.1
GLIBCXX_3.4.2
GLIBCXX_3.4.3
GLIBCXX_3.4.4
GLIBCXX_3.4.5
GLIBCXX_3.4.6
GLIBCXX_3.4.7
GLIBCXX_3.4.8
GLIBCXX_3.4.9
GLIBCXX_3.4.10
GLIBCXX_3.4.11
GLIBCXX_3.4.12
GLIBCXX_3.4.13
GLIBC_2.2.5
GLIBC_2.3
GLIBC_2.4
GLIBC_2.3.2
GLIBCXX_FORCE_NEW
GLIBCXX_DEBUG_MESSAGE_LENGTH

How can I tell g++ to grab libstdc++ from /usr/local/gcc2/lib64?

-Tristan

knudfl · 07-07-2016, 04:52 AM

The right setup for a manual build is a different name for the "extra g++/gcc" :

cd /usr/local/bin/
# rm g++
# ln -s /usr/local/gcc2/bin/g++ g++49 ( or whatever version you have built.)

Using, examples : 1) export CC=gcc[2] CXX=g++[2] && [other command]
2) make CXX=g++[2]
3) CXX=g++[2] cmake

4) Starting an application requiring /usr/local/gcc2/lib64/libstdc++.so.6 :
export LD_LIBRARY_PATH=/usr/local/gcc2/lib64:$LD_LIBRARY_PATH && [other command]
.... then /usr/local/gcc2/lib64 comes first in the LD_LIBRARY_PATH .

--------------
Another way having extra compilers in CentOS 6.8 :
https://www.softwarecollections.org/.../devtoolset-4/

# yum install centos-release-scl

# yum install devtoolset-2-gcc-c++ (provides gcc / g++ 4.8)
# yum install devtoolset-3-gcc-c++ (provides gcc / g++ 4.9)
# yum install devtoolset-4-gcc-c++ (provides gcc / g++ 5.2)
.... Unfortunately they all use the stock /usr/lib64/libstdc++.so.6

-

sundialsvcs · 07-07-2016, 01:52 PM

I would discourage you from having multiple versions of gcc, nor (especially!) glibc, if you can possibly avoid it.

knudfl · 07-07-2016, 02:37 PM

Re #3.

Quote:

I would discourage you from having multiple versions of gcc

Why ? Slackware, Fedora, CentOS, Debian, Ubuntu, Suse have 1 .. 4 extra versions of gcc/g++ available.
Examples ...
CentOS 5 : /usr/bin/{ gcc(-4.1.2), gcc34, gcc44 gcc-4.7, gcc-4.8 }
Debian Wheezy : /usr/bin/{ gcc(-4.7.2), gcc-4.4, gcc-4.6 }
Ubuntu 14.04 : /usr/bin/{ gcc(-4.8.2), gcc-4.4, gcc-4.6, gcc-4.7 }
SLE12 (Suse) : /usr/bin/{ gcc-3.3, gcc-4.8, gcc-4.9, gcc-5, gcc-6 }.

-

sundialsvcs · 07-08-2016, 07:39 AM

Available? Yes. Installed simultaneously? Probably not.

Nevertheless: the really important one is glibc, which is used by most Linux commands. It's very important that this library be in good working order.

knudfl · 07-08-2016, 10:36 AM

Re #5.

Yes, simultaneously. As you can see, they all have unique file names.
Or, for the "devtoolset-[x]-gcc-c++" examples :
Well hidden, and enabled with 'scl enable devtoolset-[x] bash'

Or the manually built gcc´s, example :
../gcc-5.2.0/configure --prefix=/usr/local/gcc52 --program-suffix=52 -- ...
I.e. you get/usr/local/gcc52/bin/{ gcc52, g++52 }.

No conflicts.

NevemTeve · 07-08-2016, 12:14 PM

The newer libstdc++.so.6 might be able to provide the functions of the older. Perhaps. (Remember, it is C++)

a4z · 07-08-2016, 12:21 PM

on CentOS/RHEL use softare collections

https://www.softwarecollections.org/.../devtoolset-3/

or, this is how I builded int this case gcc 5.3

Code:

unset LIBRARY_PATH

GCCVERSION=5.3.0

../configure          \
    --prefix=$HOME/local/opt/gcc-$GCCVERSION          \
    --libdir=$HOME/local/opt/gcc-$GCCVERSION/lib      \
    --enable-lto                \
    --disable-nls               \
    --enable-languages=c,c++

make -j10 && make install

and this is how I active the environment (by sourcing this file for a terminal)

Code:

GCCVERSION=5.3.0

export GCCDIR=$HOME/local/opt/gcc-$GCCVERSION


export LIBDIR=$GCCDIR/lib:/usr/local/lib
export PATH=$GCCDIR/bin:$CMAKEDIR/bin:$HOME/local/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin
export LD_LIBRARY_PATH=$LIBDIR
export C_INCLUDE_PATH=$GCCDIR/include
export CXX_INCLUDE_PATH=$GCCDIR/include/c++/$GCCVERSION

export CC=$GCCDIR/bin/i686-pc-linux-gnu-gcc
export CXX=$GCCDIR/bin/i686-pc-linux-gnu-g++

that's from a RHEL 6.8 workstation,