Re: [discuss] Support for reverse-execution

[Stan Shebs <shebs at apple dot com>]

Vladimir Prus wrote:

> Would not it be better to have a single "reverse" command which puts the
> debugger in "reverse" mode -- making step/stepi/next/nexti go backward.
In general, modes are bad for UI; people, even smart software
engineers, are not good at remembering modes. Think of how many
fenderbenders are caused by drivers stepping on the gas and
going in the opposite direction of what they expected. Coming
back to GDB, think of when you are using "up" and "down", then
ask to print a variable and get a complaint there is no such
variable, because you forgot which frame is current.

So I think the basic commands should be "reverse-foo" or
"back-foo" or whatever. That said, it would be pretty easy to layer
a mode on top of those for experimentation purposes, let everybody
try it out for awhile, and see what they tend to favor. For
instance, I can see a usage where a user will want to go back and
forth over a single complicated line multiple times, looking at
different variables in each step/rstep pair.

Stan