adding comments/labels?

[jf <jf@danglingpointers.net>]

After digging through the documentation some and realizing how futile
google is when you search for things like 'gdb comments' or 'gdb
labels'/et cetera, I turn to you all ;]

Is there any way to add a label/comment/rename a symbol in gdb?

specifically what I'd like to do is add symbol resolution to addresses,
i.e.

call 0x12345678

I disassemble the code at 0x12345678 and see that it just does:

mov $0x04, %al
sysenter
cmp [...]

and I can say, oh thats a sys_write wrapper, so I'd like to relabel it as
'sys_write', so now when I run across a call to it i see:

call <sys_write_wrapper>

I'm assuming no such functionality exists, as I can find nothing about it,
so that said, can anyone direct me to where I should touch gdb to add such
functionality?

thanks.