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Multiple Versions of gcc on Fedora 15

This post describes a way of building and installing additional versions of GNU gcc compiler on Fedora 15.

The version shipped with Lovelock is gcc 4.6.1 which, surprisingly, can sometimes be too new. Some apps such as nVidia CUDA SDK requires a specific version of compiler for some reason. In this howto I’ll be installing gcc-4.4.6.

Notice: There is an official installation guide that will help you if something doesn’t work (or I forgot to mention something here).

1. Getting the Source

I guess, nobody will be surprised when I say, that the first step is to obtain the sources. Go to http://gcc.gnu.com, pick a mirror and download the version you need. The best option is usually downloading the package with all languages included (e.g. gcc-4.4.6.tar.gz ). We will unpack the archive and rename the directory to source/ . It is also recommended to build the binaries into a separate directory from the sources, so we’ll create a build/ folder too:

tar xzf gcc-4.4.6.tar.gz
mv gcc-4.4.6/ source/
mkdir build/

2. Configure

Now we have everything in place, we need to configure the build. Change into the build/ directory and call the configure script:

cd build/
../source/configure --prefix=/opt/gcc4.4.6 \
                    --program-suffix=-4.4

As you can see, there are some parameters. --prefix option says where should be the gcc installed after the build. We will install it separately into the /opt directory, so it will be easily removable in the future only by deleting the respective directory. --program-suffix will be added to the name of the executable (in this case gcc-4.4 ), so it doesn’t collide with other installed versions of gcc on your system.

Warning: Be careful with the --program-suffix option. You might have to make some symlinks to use the compiler in some vendor Makefiles. It will be explained later in this post.

Optionally you can add --enable-languages=c,c++ to choose what languages support will be compiled. For more options, refer to the official guide above.

In case the configure script fails, you probably don’t have all the necessary packages installed to perform the build. See what’s missing and install it with yum. For me the following was enough:

su
yum groupinstall "Development tools"
yum install mpfr-devel

The full list of prerequisites can be found here.

3. Build

The build is fairly simple, if you see some warnings, feel free to ignore them. To build gcc write the following inside the build/ directory:

make

Now is the time to get some coffee, because it will take a while to build.

4. Installation

Installation is also quite easy. You can install gcc by writing

su
make install

Then check whether the installation was correct and everything is in place

/opt/gcc4.4.6/bin/gcc-4.4 --version

5. Using the alternative compiler

Using the alternate compiler is a little tricky. You can it to your system path by appending this line to your ~/.bashrc file.

export PATH="/opt/gcc-4.4.6/bin:$PATH"

The alternate compiler is available through gcc-4.4 name (as we defined in the configuration phase). That is cool for your Makefiles, but some vendors hardcode compiler name into their Makefile which doesn’t help at all. If this is your case, the best way to get things to work is to make symlinks to the alternate gcc and append the directory to the begining of $PATH   string. Here are example symlinks for gcc and g++:

cd /opt/gcc-4.4.6/bin
ln -s gcc-4.4 gcc
ln -s g++-4.4 g++

Note, that the system look-up in the $PATH folder is sequential, so if you append the directory to the front of the variable, it will have higher priority. If you need to use the newer compiler again, simply remove the directory from path by commenting out the line in ~/.bashrc . Remember, you can always find out version of your current gcc by writing

gcc --version

Sources