Johan Grönqvist wrote:
simon h skrev:I wonder why Debian needs three versions of the GCC compiler: 4.1, 4.2, and 4.3? Shouldn't one be enough? Is it because the compiler has no down-compatibility?I think that is the reason, yes. I also think that lack of manpower is the reason there are not even more (older) versions of gcc in debian.At <http://gcc.gnu.org/gcc-4.4/changes.html>, you can see that there are changes between versions that can break certain programs. I was recently asked for advice by someone that needs a 3.x version of gcc.(For completeness: I will suggest debootstrap/schroot for running gcc3.X without affecting his current installation.)
Yes, GCC is not downward compatible in many cases. There is no particular motivation for this because the old version is always still available, and multiple versions can be installed side by side.
An example of the need to keep an old version around is the kernel. Recent kernels use GCC 4.3, but just prior to that, kernels were compiled using 4.1. Kernel modules must be compiled using the same compiler as the kernel itself, thus the need to keep both around.
Mark Allums