Re: [PATCH v3 20/21] dyndbg: add user-flag, negating-flags, and filtering on flags

Joe Perches
2020-06-17T22:13:33Z

On Wed, 2020-06-17 at 10:25 -0600, Jim Cromie wrote:
> 1. Add a user-flag [u] which works like the [pfmlt] flags, but has no
> effect on callsite behavior; it allows incremental marking of
> arbitrary sets of callsites.
>
> 2. Add [PFMLTU] flags, which negate their counterparts; P===!p etc.
> And in ddebug_read_flags():
> current code does: [pfmltu_] -> flags
> copy it to: [PFMLTU_] -> mask
>
> also disallow both of a pair: ie no 'pP', no true & false.
>
> 3. Add filtering ops into ddebug_change(), right after all the
> callsite-property selections are complete. These filter on the
> callsite's current flagstate before applying modflags.
>
> Why ?
>
> The u-flag & filter flags
>
> The 'u' flag lets the user assemble an arbitary set of callsites.
> Then using filter flags, user can activate the 'u' callsite set.
>
> #> echo 'file foo.c +u; file bar.c +u' > control # and repeat
> #> echo 'u+p' > control
>
> Of course, you can continue to just activate your set without ever
> marking it 1st, but you could trivially add the markup as you go, then
> be able to use it as a constraint later, to undo or modify your set.

Does this set selection also allow for selection by
increasing decimal level?

Can sites be enabled for a value less than x?