How to upgrade GCC to 4.7+ on Ubuntu 12.04

October 02, 2013

Note: This is only needed on Ubuntu 12.04. Ubuntu 12.10 already comes with GNU C++ 4.7 and above.

Install

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get install gcc-4.7 g++-4.7

Update Alternatives

Add GCC 4.7

sudo update-alternatives --remove gcc /usr/bin/gcc-4.6
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.7 60 --slave /usr/bin/g++ g++ /usr/bin/g++-4.7
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.6 40 --slave /usr/bin/g++ g++ /usr/bin/g++-4.6

Make sure GCC 4.7 is the default alternative

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-4.7 60 auto mode
1 /usr/bin/gcc-4.6 40 manual mode
2 /usr/bin/gcc-4.7 60 manual mode

Press enter to keep the current choice[*], or type selection number: 0

Verify

gcc --version
gcc (Ubuntu/Linaro 4.7.3-2ubuntu1~12.04) 4.7.3
Copyright (C) 2012 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.

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