How can I update gcc 5.3 to 6.1?

Question

After installing Ubuntu 16.04 LTS, I found that gcc 5.3 installed by default but I don't receive any updates to gcc. I opened up GCC website and I found the new release 6.1. How do I update?

Output of gcc --version:

gcc (Ubuntu 5.3.1-14ubuntu2.1) 5.3.1 20160413
Copyright (C) 2015 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.

See How can I install and use gcc 6 on xenial? – steeldriver Jun 05 '16 at 01:29 — steeldriver, Jun 05 '16 at 01:29

score 34 · Accepted Answer · edited Sep 29 '17 at 17:04

34

You can install GCC 6 by adding the ubuntu-toolchain-r/test PPA. To do so, run the following commands:

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt update
sudo apt install gcc-6

You can verify that gcc-6 is installed by running gcc-6 --version and the output should say gcc-6 (Ubuntu 6.1.1-2ubuntu12~16.04) 6.1.1 20160510.

As suggested by Mohamed Slama, if you want to further change the default GCC and G++ to the latest versions, install g++-6 with

sudo apt install g++-6

and then run

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-6 60 --slave /usr/bin/g++ g++ /usr/bin/g++-6

edited Sep 29 '17 at 17:04

fragapanagos

105
2

answered Jun 05 '16 at 01:29

edwinksl

23,789

Are you using it? how stable is it? – Videonauth Jun 05 '16 at 01:30
@Videonauth I am not using it. I know from a colleague that GCC 6 introduced regressions that broke the compilation of a software that we use. – edwinksl Jun 05 '16 at 01:31
Ah o.k. well then i rather stay at 5.3.1 for now. – Videonauth Jun 05 '16 at 01:32
@Videonauth Yeah, there is no harm installing gcc-6 though and trying to see if it works for you. Your gcc 5.3.1 is still around and gcc is still symlinked to gcc-5 instead of gcc-6. – edwinksl Jun 05 '16 at 01:33
3

what does 60 do here? – ar2015 Oct 01 '18 at 05:01
1

its 2021 and These steps worked lika a charm for me. I get gcc 6.5 version. Latest yocto require gcc > 6 so i think gcc-6 is stable now. – Jeegar Patel Jan 05 '21 at 09:26

score 7 · Answer 2 · edited Jan 09 '20 at 11:54

7

If you want to build it from source (which I recommend as you can for example make a cross-compiler, etc.) download the source from a mirror.

Then extract it with:

tar -xvf gcc-6.1.0.tar.gz

After that change directory to there:

cd gcc-6.1.0

Then create build directory and cd to it:

mkdir build
cd build

Then configure the makefile (--disable-multilib means to not build libraries for cross-compilation):

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

If you ran into errors due to missing required libraries or other prerequisites: (Credits to this)

./contrib/download_prerequisites

And then build it:

make -j 8

This process may take some time and after done invoke this:

sudo make install

That's it!

edited Jan 09 '20 at 11:54

Jeremy

2,846

answered Jun 05 '16 at 03:16

Ehsan

183

While the -j flag speeds up the compilation quite a bit it is not advised to use it building tool-chain executables, and a make check should be run before installing. – Videonauth Jun 05 '16 at 03:20
Well that worked for me :) and I even built a cross compiler with it – Ehsan Jun 05 '16 at 03:21
1

I didn't say that it wont work, but gcc and g++ are more than only compilers for C, C++. – Videonauth Jun 05 '16 at 03:29
But @Videonauth when I didn't use -j flag it took 3 hours to build it which was very frustrating :| – Ehsan Jun 05 '16 at 03:31
I know, and it takes even longer on older systems to make a full compile and check on my very old dual core laptop took 3 days all in all. You might want to have a look at how a Linux is build from scratch this might shed some light, they explain on those sites as well why compiling with flags is not the best idea if you plan to rely on it. Saying that i have successfully build a couple of personal used Linux systems myself meanwhile. – Videonauth Jun 05 '16 at 03:35
You should never do sudo make install on your distro without setting installation prefix first. Keeping up with different versions of self compiled and installed apps and being able to remove them afterwards will be really nasty after having few different versions compiled and installed to default prefix. Better to have separate directory for every version and to use stow (https://www.gnu.org/software/stow/) or something similar to just handle symbolic links which will be installed under /usr/local – Mikael Lepistö Jun 28 '18 at 12:08
So now you have both version of gcc OR only latest one ? – Arun Pal Feb 20 '19 at 10:07

How can I update gcc 5.3 to 6.1?

2 Answers2