Debugging with GDB and ASLR

Hi,

It is well known that ASLR can get in the way of debugging some
problems because the addresses of data change between runs, and so
what you have learned from one debugging session cannot always be
safely used in another session, when ASLR is in effect.

I'm told that GDB disables ASLR, at least on GNU/Linux, for that
reason.  If that is true, could someone please point me to the code
which achieves that?  Also, is this done on other systems as well, and
specifically on MS-Windows when debugging native Windows programs?

TIA