Re: [patch] [python] Prompt substitution

[Pedro Alves <pedro@codesourcery.com>]

On Tuesday 30 August 2011 21:33:24, Phil Muldoon wrote:
> Pedro Alves <pedro@codesourcery.com> writes:
> 
> > On Wednesday 20 July 2011 12:33:24, Phil Muldoon wrote:
> >> +gdb_test_multiple "set prompt blah " "set blah in GDB" {
> >> +    -re "\[\r\n\]$newprompt2 $" {
> >> +       pass "set prompt blah overriden"
> >> +    }
> >> +}
> >> +
> >> +gdb_test_multiple "python gdb.prompt_hook = None" "Delete hook" {
> >> +    -re "\[\r\n\]$newprompt2 $" {
> >> +       pass "Delete old hook"
> >> +    }
> >> +}
> >
> > Hmm:
> >
> > ...
> > PASS: gdb.python/python.exp: show prompt shows guarded prompt
> > set prompt blah 
> > py prompt 2 PASS: gdb.python/python.exp: set prompt blah overriden
> > python gdb.prompt_hook = None
> > py prompt 2 PASS: gdb.python/python.exp: Delete old hook
> >
> > I think this last PASS is actually a bug.  We've disabled the python
> > hook, so we should get the "set prompt" prompt back ("blah")
> > instead of still seeing the python prompt.  Agree?
> >
> > (My WIP no-prompt-stack patch turned that into a FAIL,
> > but it looks like it's a bug fix, not a regression.)
> 
> I think in the case, display_gdb_prompt is just displaying what GDB
> knows to be the prompt.  If you delete the hook, whatever was the prompt
> when the prompt was set will remain the prompt.  So the hook set the
> prompt whenever in time, and when you delete the hook, it won't restore
> what the old prompt was.  So if you disable the prompt, then set prompt
> foo, then you will get "foo" now until you change it again manually. In
> the case of "guarded prompt" (IE >) it won't attempt to alter that
> display at all.

I see.  I assumed that the python hook worked by overriding
"set prompt", but that the result wouldn't be seen by "show prompt".
That is, set/show prompt always worked at the "this is what
I want the prompt to look like if no scripting overrides it" level.
Okay, I preserved the current behaviour.  Matt's new (uncommitted)
py-prompt.exp tests were great for making sure I did.  :-)

Thanks!

-- 
Pedro Alves