Installing GCC

Go to the specified directory and download the file. (The /opt/tools/installed directory is used as an example.)
```
cd /opt/tools/installed/
wget https://ftp.gnu.org/gnu/gcc/gcc-7.3.0/gcc-7.3.0.tar.gz
```
Decompress the source package.
```
tar -xf gcc-7.3.0.tar.gz
```
Go to the source code directory and install bzip2.
```
cd gcc-7.3.0
yum install -y bzip2
```

Download the dependency.

./contrib/download_prerequisites

Ensure that the network is connected. If the download fails, you can manually download the file.

wget http://gcc.gnu.org/pub/gcc/infrastructure/gmp-6.1.0.tar.bz2 
wget http://gcc.gnu.org/pub/gcc/infrastructure/mpfr-3.1.4.tar.bz2 
wget http://gcc.gnu.org/pub/gcc/infrastructure/mpc-1.0.3.tar.gz 
wget http://gcc.gnu.org/pub/gcc/infrastructure/isl-0.16.1.tar.bz2

After the manual download is complete, run the script again.
```
./contrib/download_prerequisites
```

Edit the configuration.

./configure --enable-languages=c,c++ --disable-multilib --with-system-zlib --prefix=/usr/local/gcc7.3.0

Perform compilation and installation.
```
make -j15
make install
```
Set environment variables.
1. Open the /etc/profile file.
```
vim /etc/profile
```
2. Press i to enter the insert mode and add the commands at the end of the file:
```
export LD_LIBRARY_PATH=/usr/local/gcc7.3.0/lib64:${LD_LIBRARY_PATH}
export CC=/usr/local/gcc7.3.0/bin/gcc
export CXX=/usr/local/gcc7.3.0/bin/g++
```
3. Press Esc, type :wq!, and press Enter to save the file and exit.
Make the environment variables take effect.
```
source /etc/profile
```
Verify the installation.
```
gcc -v
```
```
g++ -v
```
The installation path depends on the preceding configurations. You only need to pay attention to the version number.

Parent topic: Configuring the Compilation Environment