#step1 install gcc8.1 follow this site install_gcc8.1 #step 2 follow ELF offical install instruction ,stop before "make"
#step 3 export some env info
export CC="/home/username/install_path/gcc_8.1/bin/gcc -Wno-cast-function-type "
export CXX="/home/username/install_path/gcc_8.1/bin/g++ -Wno-cast-function-type "
export CPP="/home/username/install_path/gcc_8.1/bin/g++ -Wno-cast-function-type "
#step4 make ..go continue follow offical guide