Copied from :
https://linuxhostsupport.com/blog/how-to-install-gcc-on-centos-7/
Install GCC from source
If you need a newer version of GCC than the one distributed by the official CentOS 7 repositories you can install it from source.
It is highly recommended to start a screen session before starting the installation. Run the following command
screen -U -S gcc
Download the tarball of the GCC version you want to install. In our example we will use GCC version 7.3.0
wget http://ftp.mirrorservice.org/sites/sourceware.org/pub/gcc/releases/gcc-7.3.0/gcc-7.3.0.tar.gz
Unpack the tar archive and change the current working directory
tar zxf gcc-7.3.0.tar.gz cd gcc-7.3.0
Install bzip2 and run the ‘download_prerequisites’ script to download some prerequisites needed by GCC. You have to run this from the top level of the GCC source tree.
yum -y install bzip2 ./contrib/download_prerequisites
Once the prerequisites are downloaded execute the following command to start configuring the GCC build environment
./configure --disable-multilib --enable-languages=c,c++
Once it is completed, run the following command to compile the source code. It may take a few hours for the compilation to complete, so sit back and relax.
make -j 4 make install
