[Bug c++/56879] New: -Weffc++ warns about non-virtual base class destructor even if it is protected

[Bug c++/56879] New: -Weffc++ warns about non-virtual base class destructor even if it is protected

[ayurchen at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56879

             Bug #: 56879
           Summary: -Weffc++ warns about non-virtual base class destructor
                    even if it is protected
    Classification: Unclassified
           Product: gcc
           Version: 4.7.2
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: ayurchen@gmail.com


Created attachment 29827
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29827
test source code and compiler output

Protected destructor means that the class can't be deleted polymorphically, so
this warning is unnecessary. Together with -Werror it becomes a pain.

[Bug c++/56879] -Weffc++ warns about non-virtual base class destructor even if it is protected

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56879

Jonathan Wakely <redi at gcc dot gnu.org> changed:

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--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2013-04-08 17:15:59 UTC ---
Comment on attachment 29827
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29827
test source code and compiler output

The solution is simple: don't use -Weffc++, it's deeply flawed. Using it with
-Werror is just ridiculous.  It's much better to use -Wdelete-non-virtual-dtor
than -Weffc++

There are lots of known issues with -Weffc++ and noone has been motivated to
fix them, see e.g. PR 22395 comment 5 and  PR 16166 comment 3 for some
discussion related to this warning.

[Bug c++/56879] -Weffc++ warns about non-virtual base class destructor even if it is protected

[ayurchen at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56879

--- Comment #2 from alex <ayurchen at gmail dot com> 2013-04-08 19:06:47 UTC ---
(In reply to comment #1)
> Comment on attachment 29827 [details]
> test source code and compiler output
> 
> The solution is simple: don't use -Weffc++, it's deeply flawed. Using it with
> -Werror is just ridiculous.  It's much better to use -Wdelete-non-virtual-dtor
> than -Weffc++

It is not what we've been using it for (-Wdelete-non-virtual-dtor seems to be
enabled by -Wall already). We'd like to keep other warnings that -Weffc++
generates: it worked nicely for us until this point.

> There are lots of known issues with -Weffc++ and noone has been motivated to
> fix them, see e.g. PR 22395 comment 5 and  PR 16166 comment 3 for some
> discussion related to this warning.

Too bad. This one could probably be a one-liner to just disable this warning
since -Wnon-virtual-dtor is already enabled with -Weffc++ (and it does a better
job). But "noone has been motivated" says it all. Anyway, thanks for the
pointers.