多版本GCC安装及切换

目录

• 1 背景
• 2 安装
• • 2.1 Ubuntu 20.04
  • 2.2 Ubuntu 18.04
  • 3 配置
  • 4 切换
  • • 4.1 切换到版本9
    • 4.2 切换到版本10

      1 背景

      最近在研究C++20中的协程需要安装GCC版本10。用到GCC多版本切换，记录步骤。

      
      （图片来源网络，侵删）

      2 安装

      2.1 Ubuntu 20.04

      运行如下命令安装两个版本编译器:

      sudo apt install gcc-9 g++-9
      sudo apt install gcc-10 g++-10
      

      2.2 Ubuntu 18.04

      默认安装最高版本gcc-7,添加Toolchain Test Builds PPA（个人软件包存档），它提供了GCC 10的最新版本

      sudo add-apt-repository ppa:ubuntu-toolchain-r/test
      sudo apt install gcc-9 g++-9
      sudo apt install gcc-10 g++-10
      

      3 配置

      使用update-alternatives命令配置多编译器版本:

      sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-9 90 --slave /usr/bin/g++ g++ /usr/bin/g++-9
      sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-10 100 --slave /usr/bin/g++ g++ /usr/bin/g++-10
      

      说明:

      • gcc与g++版本绑定在一起了，修改gcc版本会同时修改g++版本

        4 切换

        使用如下命令切换编译器版本:

        sudo update-alternatives --config gcc
        

        4.1 切换到版本9

        $ sudo update-alternatives --config gcc
        There are 2 choices for the alternative gcc (providing /usr/bin/gcc).
          Selection    Path             Priority   Status
        ------------------------------------------------------------
        * 0            /usr/bin/gcc-10   100       auto mode
          1            /usr/bin/gcc-10   100       manual mode
          2            /usr/bin/gcc-9    90        manual mode
        Press  to keep the current choice[*], or type selection number: 2
        

        查看版本:

        $ gcc --version
        gcc (Ubuntu 9.4.0-1ubuntu1~20.04.3) 9.4.0
        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.
        $ g++ --version
        g++ (Ubuntu 9.4.0-1ubuntu1~20.04.3) 9.4.0
        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.
        

        4.2 切换到版本10

        $ sudo update-alternatives --config gcc
        There are 2 choices for the alternative gcc (providing /usr/bin/gcc).
          Selection    Path             Priority   Status
        ------------------------------------------------------------
        * 0            /usr/bin/gcc-10   100       auto mode
          1            /usr/bin/gcc-10   100       manual mode
          2            /usr/bin/gcc-9    90        manual mode
        Press  to keep the current choice[*], or type selection number: 1
        

        查看版本:

        $ gcc --version
        gcc (Ubuntu 10.5.0-1ubuntu1~20.04) 10.5.0
        Copyright (C) 2020 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.
        $ g++ --version
        g++ (Ubuntu 10.5.0-1ubuntu1~20.04) 10.5.0
        Copyright (C) 2020 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.