program spaces vs exec

[Doug Evans]

Hi.

Question: Why does the program space remain unchanged across an exec?
[for reference sake, target = amd64-linux]

Is it just expediency?  Or is there a functional reason?

I ask because, for example, registering pretty-printers
with a particular progspace doesn't work as one would expect
in this case.  E.g., One needs the pretty-printers from the
previous program to be gone when the new one loads.

This concerns more than just exec of course.
E.g., Any time the "main" objfile is changed (e.g., "file foo") I'd intuitively
expect a new program space.

OTOH, it's entirely possible progspaces need to be looked at differently
for *nix.

For reference sake, from the archives I found this:
http://sourceware.org/ml/gdb-patches/2009-10/msg00110.html