Re: PATCH: resume + threads + software stepping == boom

Michael Snyder
2001-06-08T16:19:00Z

Daniel Jacobowitz wrote:
>
> resume () in infrun.c has this block:
>
> if (SOFTWARE_SINGLE_STEP_P () && step)
> {
> /* Do it the hard way, w/temp breakpoints */
> SOFTWARE_SINGLE_STEP (sig, 1 /*insert-breakpoints */ );
> /* ...and don't ask hardware to do it. */
> step = 0;
>
> Then, further down, if (use_thread_step_needed && thread_step_needed)
> and there's already a breakpoint at the PC, is this:
>
> if (!step)
> {
> warning ("Internal error, changing continue to step.");
>
> That blows up, because step will always be zero here if
> SOFTWARE_SINGLE_STEP_P (). Is this patch OK? It seems to work in my tests
> here.

I like the problem analysis, but not the implementation of the solution.
If we are going to always set step to zero for SOFTWARE_SINGLE_STEP_P,
then it does not make sense to set it to one again, even if the code
will never be reached (in theory). I would rather see it made explicit
that this code should never be reached if SOFTWARE_SINGLE_STEP_P is true.
Something like this:

< if (!step)
---
> if (!(step && SOFTWARE_SINGLE_STEP_P()))