[Bug fortran/69520] New: Implement reversal of -fcheck options

["anlauf at gmx dot de" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69520

            Bug ID: 69520
           Summary: Implement reversal of -fcheck options
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: anlauf at gmx dot de
  Target Milestone: ---

Created attachment 37494
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37494&action=edit
Patch

Hello,

as explained in

https://gcc.gnu.org/ml/fortran/2016-01/msg00082.html

I'd like to see an enhancement to the -fcheck options to
selectively disable a specified check.  I took my patch
from

https://gcc.gnu.org/ml/fortran/2016-01/msg00084.html

and added some "documentation" to this enhancement,
see the attached patch.

I don't have a strong opinion on whether the prefix for disabling
should be "no" or "no-", or whether both should be accepted.
The present patch implements the first variant.  If there is some
guideline to use the latter, the changes are obviously trivial.

It works for me... :)

If a ChangeLog entry is needed, I can also provide it.

Thanks,
Harald