use gcc 5.x on ubuntu 14.04

gcc 5 on ubuntu 14.04

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get install gcc-5 g++-5

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 60 --slave /usr/bin/g++ g++ /usr/bin/g++-5

gcc7

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

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-7 60 --slave /usr/bin/g++ g++ /usr/bin/g++-7

thx

WARNING @beci @vineeshvs @hallahan @Antttooon @MagnetonBora @rrogers @dtamez @benzkji @NorimasaNabeta:

The ppa:ubuntu-toolchain-r/test has old compiler builds that don't correctly compile some dkms kernel drivers, like nVidia, and you can get your installation pretty broken with the compilers from this PPA. See this launchpad issue for details.

update-alternatives: error:

I'm working on Ubuntu 16.04. The first three code ran properly, but when I was running the code

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 60 --slave /usr/bin/g++ g++ /usr/bin/g++-5

I got the error:

update-alternatives: error: alternative g++ can't be slave of gcc: it is a master alternative

Can someone answer me what may have gone wrong?

good job, works , thank you!

Thank you, it worked.

fast&clean

kudos

@SeanSyue I'm got the same error as yours. Can you please help me if you figured it out.

thank you

@SeanSyue, @apoorva-js, See the following link
https://askubuntu.com/questions/372248/downloaded-g-4-8-from-the-ppa-but-cant-set-it-as-default

It works like a charm on Ubuntu 18.04. Thank you 👍

Thanks

worked .....thanks

ppa:ubuntu-toolchain-r/test

seems like it's not being updated or bugfixed properly and could even leave your Ubuntu 14.04 machine in an unbootable state. Beware...

See here a bunch of people breaking their installations of apt-get and gnome by blindly using that repo:

https://askubuntu.com/questions/777803/apt-relocation-error-version-glibcxx-3-4-21-not-defined-in-file-libstdc-so-6#

the following error appears when trying to compile using the flag -fsanitize=signed-integer-overflow

/usr/bin/ld: unrecognized option '--push-state--no-as-needed'
/usr/bin/ld: use the --help option for usage information

It's work for me!
Thanks!

For me this worked:
sudo apt-add-repository "deb http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu trusty main"
sudo apt-get update
sudo apt-get install gcc-5 g++-5