Is there any real need for a prompt stack?

[Pedro Alves <pedro at codesourcery dot com>]

I'm looking at fixing these regressions in async mode, compared
to sync mode, apparently recently introduced (I suspect w/ the
set_prompt stuff)

Running ../../../src/gdb/testsuite/gdb.base/default.exp ...
FAIL: gdb.base/default.exp: info set (incomplete output)
FAIL: gdb.base/default.exp: show prompt
FAIL: gdb.base/default.exp: show (incomplete output)

and wondering, is there any real need for a prompt stack?

push_prompt and pop_prompt already internally break the abstraction
by special casing async mode, and switching between anotation levels,
which appear to be 2 or the 3 the major users of push/pop in the
first place.  It looks like we can rip the stack out, and just
end up with a function that returns the current prompt, based
on the current annotation level, and the sync_execution, more_to_come
and new_async_prompt globals.

Has anyone tried that and understood why it wouldn't work?

-- 
Pedro Alves