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Nickolai Leschov
Asked: 2014-05-16 17:11:01 +0800 CST

How do I use the latest GCC on Ubuntu?

  • 772

I want to compile my program with the latest version of gcc.

Ubuntu 14.04 comes with gcc 4.8.2, however there's 4.9.0 available, moreover, I see that it is available as a package: gcc-4.9. I tried to install it

sudo apt-get install gcc-4.9

but it says

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Note, selecting 'gcc-4.9-base' for regex 'gcc-4.9'
gcc-4.9-base is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

Looks like it is already installed, just not as the default one? How do I utilize it to build my program?

software-installation

5 Answers

  1. Best Answer

    The best way to correctly install gcc-4.9 and set it as your default gcc version use:

    sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get install gcc-4.9 g++-4.9
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.9 60 --slave /usr/bin/g++ g++ /usr/bin/g++-4.9

    The --slave, with g++, will cause g++ to be switched along with gcc, to the same version. But, at this point gcc-4.9 will be your only version configured in update-alternatives, so add 4.8 to update-alternatives, so there actually is an alternative, by using:

    sudo apt-get install gcc-4.8 g++-4.8
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.8 60 --slave /usr/bin/g++ g++ /usr/bin/g++-4.8

    Then you can check which one that is set, and change back and forth using:

    sudo update-alternatives --config gcc

    If you have an issue with update-alternatives gcc priority 60 not being higher than previous versions installed you can use the previous update-alternatives --config gcc command to check installed versions and use:

    sudo update-alternatives --remove gcc

    Or:

    sudo update-alternatives --remove-all gcc

    NOTE: You could skip installing the PPA Repository and just use /usr/bin/gcc-4.9-base but I prefer using the fresh updated toolchains.

    For GCC 5.X or 6, the packages (and correspondingly, the commands) are just called gcc-5, gcc-6, etc. This is due to the change in GCC's version scheme, where 5.1 is the first GCC 5 release, and future 5.X releases are for bug fixes.

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  2. Ultimate mega master compatibility table

    OK let's do this:

                   GCC                clang
        +-------------------+--------------------------+
        | 11 10 9 8 7 6 5 4 | 14 13 12 11 10 9 8 7 6 5 |
+-------+-------------------+--------------------------+
| 22.04 |  D  M M           |  D  M  M  M              |
| 21.10 |  D  M M M         |     D  M  M  M M         |
| 21.04 |  M  D M M M       |        D  M  M M         |
| 20.10 |     D M M M       |           D  M M M M M   |
| 20.04 |     P D M M       |              D M M M M   |
| 19.10 |       D M M       |                          |
| 19.04 |       M D M M     |                          |
| 18.10 |         D M M M   |                          |
| 18.04 |     P P M D M M   |                M M M D M |
| 16.04 |       P P P P D M |                          |
+-------+-------------------+--------------------------+

    All the questions:

    How to set a non-default GCC as the default?

    E.g., you installed /usr/bin/gcc-7 but you want to use that instead of /usr/bin/gcc when you run gcc main.c.

    Use sudo update-alternatives as mentioned in other answers: https://askubuntu.com/a/581497/52975 It creates the required symlinks for you.

    See also: What exactly does `update-alternatives` do?

    How to build your own toolchain from source

    If even the PPA is not old/new enough for you, see this:

    Older GCC version questions

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  3. Use the Toolchain Test Builds PPA:

    sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get install gcc-4.9

    I don't think GCC 4.9 is fully available for Ubuntu 14.04 yet. The base package (gcc-4.9-base) and the GCC Go 4.9 compiler (gccgo-4.9) are available, but the other frontends are not. I don't know why.

    • 25

  4. Ubuntu 16.04 and later

    You can already install gcc 7.0 in Ubuntu 18.04 from the default repositories. To install gcc-7 in Ubuntu 17.10, 18.04 and 18.10 open the terminal and type:

    sudo apt install gcc-7

    To install gcc-8 in Ubuntu 18.04 and later open the terminal and type:

    sudo apt install gcc-8

    To install gcc-9 in Ubuntu 19.04 and later open the terminal and type:

    sudo apt install gcc-9

    You can install gcc-7 in Ubuntu 16.04 from ppa:jonathonf/gcc-7.1.

    sudo add-apt-repository ppa:jonathonf/gcc-7.1  
sudo apt update  
sudo apt install gcc-7

    You can install gcc-8 in Ubuntu 16.04 from ppa:jonathonf/gcc-8.0.

    sudo add-apt-repository ppa:jonathonf/gcc-8.0  
sudo apt update  
sudo apt install gcc-8

    Multiple versions of gcc can be installed alongside each other. You can change the default gcc version by using the update-alternatives command to determine which actual file is referenced by a generic name, for example which actual file is referenced by gcc. For more information see the answers to this question: How to change the default GCC compiler in Ubuntu?.

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  5. To call gcc 4.9 specifically, use gcc-4.9 at the command prompt.

    All the gcc versions you have installed can be called individually by adding a hyphen and the version number at the end of gcc. In your case, gcc-4.8 and gcc-4.9 should be available. In a terminal, type gcc- (note the hyphen) and the push tab twice to see if there are any other versions installed.

    Note that the default gcc is likely still 4.8. (Use gcc -v to verify this.) Unfortunately changing the default is not trivial if you installed gcc-4.9 from the default repository as it did not add a update-alternatives entry. If you are interested in how to change the default, see answers to this this question.

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