GCC官网
GMP 官网
MPFR
MPC

1. 前往GCC官网 下载最新gcc，下载完成后解压安装包：

tar -zxcf gcc-9.2.0.tar.gz

2. 获取依赖 GMP,MPFR,MPC

cd gcc-9.2.0
#执行
./contrib/download_prerequisites

3. 安装gcc

./configure -enable-checking=release -enable-languages=c,c++ -disable-multilib

make && make install

查看版本信息，如果没有更改则修改环境变量

[root@localhost bin]# gcc --version
gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-23)
Copyright (C) 2010 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.

4. 添加环境变量，否则gcc还是识别旧版本。

vi /etc/profile
#添加：
...
PATH=/usr/local/bin:$PATH
...
#重启profile
source /etc/profile

5. 再次检测版本是否变化.

#安装成功
[root@localhost bin]# ./gcc --version
gcc (GCC) 9.2.0
Copyright (C) 2019 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.