Re: Library naming

[Per Bothner <bothner@cygnus.com>]

Duane Ellis <duane_ellis@franklin.com> writes:
> Here where I work, we maintain 6 different versions of emacs
> [4 emacs vrs, and 2 mule vrs] Having emacs use it's version
> number in finding libraries & extensions is of paramount importance.
> Not to mention various versions of gcc we keep around..

But using the version number to keep apart different versions of gcc
is definitely the wrong way to do it.  (I suspect the same is true
of Emacs.)  Three major problems:
1) The actual gcc program of one version may be incompatible with the
various programs of another version.  Therefore you cannot reliably
use (-b -V), but instead need to install multiple gcc drivers.
Hence the version number does not buy you anything.
2) You need to be careful to uninstall one version without missing up.
3) The C++ libraries may depend on a specific Gcc version number
(a fact of life, given that we are still trying to catch up with the
draft C++ standard).  But libg++ does not install in a version directory.

The better approach is to use --prefix to install gcc and libg++
exactly where you want them.  Then use symlinks to make the preferred
version the default (in most users' PATH).  That is what Cygnus does.

	--Per Bothner
Cygnus Solutions     bothner@cygnus.com     http://www.cygnus.com/~bothner