Retiring obsolete files

Retiring obsolete files

[Stan Shebs]

One of the problems with maintaining GDB over a long period of time is
that, unlike GCC, GDB includes files that can only be compiled and run
on a particular host.  If the host is obsolete or simply scarce, it
becomes impossible to ensure that GDB's code for that host is still
correct, and in fact that code may actively mislead current and future
maintainers looking for examples of how to solve a problem.

I discussed this with RMS, and he wasn't keen to simply delete files,
for the reason that one doesn't necessarily know for sure that the
configuration no longer exists, and if someone wanted to revive it, it
might be very difficult to find a GDB release with the old files still
present.  However, he thought it would be OK to mark files as
obsolete.  So I came up with a compromise proposal that I'd like to
try out on people.

Files that seem to be obsolete first get marked with this sed script:

	sed -e 's,*/,*//*,g' -e 's,^,/* OBSOLETE ,' -e 's,$, */,'

This puts the word 'OBSOLETE' on every line, plus comments out all the
code, thus making its status obvious to readers, to grep, and to any
source analysis tools that might look inside a #if 0 ... #endif.  In
addition, the gdb/NEWS file gets a note to the effect that a file or
config is obsolete.  This situation lasts for one release.  Then, at
the time of the next release, if no one has come forward to save the
file, it gets deleted, and a note is made of that in NEWS.  Over time,
old junk will disappear from the source, thus making room for new junk. :-)

Opinions?  If no one objects, I will set this in motion for 4.18.

								Stan

Re: Retiring obsolete files

[Jim Blandy]

> Opinions?  If no one objects, I will set this in motion for 4.18.

It sounds good to me.

How does this approach compare with making a new directory tree
gdb/obsolete?  So gdb/config/victrola would get moved to
gdb/obsolete/config/victrola?

Is your sed script invertible?  Someone resuscitating an old platform
would probably appreciate that.  If the file contains any *//*
sequences to begin with, then I think it isn't.  How about

	sed -e 's,*,*x,g' 

to deal with existing comments, and everything else stays the same?
After you've stripped off the "/* OBSOLETE " and " */" that were
guaranteed to be added to every line, then you know that

	sed -e 's,*x,*,g'

will restore everything properly, even if there were "*x" sequences in
the code already.