12

I have gcc 4.6.3 installed:

gcc --version

gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3

I have installed newer version:

apt-get install gcc-4.7

But i still get result "gcc 4.6.3" when I type gcc --version. How to fix it?

I am using ubuntu 12.04 and i have done

sudo apt-get update
sudo apt-get upgrade
Rafał Cieślak
  • 21,054
Sashko Lykhenko
  • 303

3 Answers3

13

This is because you have both versions installed, with 4.6 being treated as the default one.

You can explicitly choose which one to use.

$ gcc-4.7 --version
gcc-4.7 (Ubuntu/Linaro 4.7.2-22ubuntu4) 4.7.2
[...]

$ gcc-4.6 --version
gcc-4.6 (Ubuntu/Linaro 4.6.3-15ubuntu3) 4.6.3
[...]

The easiest way make gcc-4.7 the default gcc is to move the symlink of /usr/bin/gcc:

sudo rm /usr/bin/gcc
sudo ln -s /usr/bin/gcc-4.7 /usr/bin/gcc
Rafał Cieślak
  • 21,054
  • 2
    How to set gcc-4.7 default? – Sashko Lykhenko Mar 17 '13 at 21:30
  • @СашкоЛихенко Do you wish to just make gcc-4.7 the default gcc, or would you rather easily switch gcc between gcc-4.6 and gcc-4.7? – Rafał Cieślak Mar 17 '13 at 21:34
  • I probably need it because I get the following error message installing Webkit application fom source.

    configure: error: Compiler GCC >= 4.7 or Clang >= 3.0 is required for C compilation

     – Sashko Lykhenko Mar 17 '13 at 21:35
  • @СашкоЛихенко This makes sense. GCC 4.7 introduces support for C++0x standard, which may be required by new software. – Rafał Cieślak Mar 17 '13 at 21:36
  • I want to make gcc-4.7 the default gcc. Hope that helps – Sashko Lykhenko Mar 17 '13 at 21:37
  • @СашкоЛихенко I have updated my answer. – Rafał Cieślak Mar 17 '13 at 21:41
  • Now i get gcc (Ubuntu/Linaro 4.7.2-11precise2) 4.7.2 when type gcc --version. But webkit error remained. – Sashko Lykhenko Mar 17 '13 at 21:49
  • @СашкоЛихенко Try explicitly prepending all ./configure, make etc. commands with CC="gcc-4.7", e.g. CC="gcc-4.7" make. Anyway, as you have correct gcc --version, this seems to be a separate problem with webkit compilation. Also, maybe you need to clear it's build cache (get a fresh copy of sources). – Rafał Cieślak Mar 17 '13 at 21:54
  • didn`t work. I should probably rise the question about webkit in separate thread. Thanks for answering this question anyway :) – Sashko Lykhenko Mar 17 '13 at 22:03
  • Overwriting the gcc symlink is a bad idea, gcc should be the compiler with which most software on the system, especially the kernel, was build, having a different version could cause bugs which would be difficult to pinpoint. If a specific version of GCC is needed to compile a specific program, it should be defined in the relevant Makefiles (or whatever build system the program uses) using the CC variable (as @RafałCieślak correctly notes). – fkraiem Jul 11 '14 at 10:23
0

If you are looking for installation of old version of gcc, then install directly from command line. For instance if you want install gcc-4.4.6, and latest available version is 4.7.3. If you type:

sudo apt-get install gcc

then by default latest version will be installed. To install gcc-4.4.6, just type:

sudo apt-get install gcc-4.4

But still your default compiler is latest gcc. To remove latest gcc as default type:

sudo rm /usr/bin/gcc

Now making gcc-4.4.6 as default compiler (this is replacement of gcc by gcc-4.4.x), type:

sudo ln -s /usr/bin/gcc-4.4 /usr/bin/gcc

Hope this will clarify above mentioned problem.

Tim
  • 33,510
Satish Patil
  • 91
  • 1
  • 3
-1

please follow this instruction: Build gcc (Here: version: 4.7.2)

tar -xf gcc-4.7.2.tar.bz2
mkdir gcc-build
cd gcc-build
../gcc-4.7.2/configure --enable-languages=c,c++
make -j 4
make install
make clean          (OPTIONAL)
cd ..

Currently, the self-check of the gcc is not working, so this step is omitted here. Now you should check that the new compiler version 4.7.2 is called instead of the compiler used for the build process (here gcc-4.5.3). Enter the following commands:

gcc --version; g++ --version

The new compiler has been installed in /usr/local/bin. It is now the default compiler, because in the PATH variable /usr/local/bin is before /usr/bin.

Braiam
  • 69,302
farhad rad
  • 1