On Nov 2, 2005, Stephan Bergmann wrote:
Hi all,
<http://www.openoffice.org/issues/show_bug.cgi?id=56995> shows the
following problem: On compilers later than the GCC 3.4.1 we use at
Hamburg (e.g., GCC 4.0.2, but from looking at the documentation also GCC
3.4.4), -Wall implies a new -Wnon-virtual-dtor which warns about
classes with virtual functions that do not have a virtual destructor.
On such compilers, this warning will occur for each idlc-generated UNO
header (com/sun/star/uno/XInterface.hpp etc.). For reasons of
compatibility, it is not an option to change those idlc-generated
headers and add a virtual destructor to them.
Thus, we can either switch off -Wnon-virtual-dtor globally, or switch
off *all* warnings from within idlc-generated headers (#pragma GCC
system_header). The second option is probably preferable, as
-Wnon-virtual-dtor might point to real issues in other places of the
code base, and it is unlikely that there would be other warnings from
any idlc-generated header that we would thus suppress---the
idlc-generated headers are pretty boiler-plate.
Opinions?
-Stephan
The consensus back then was to keep -Wnon-virtual-dtor switched on
globally, and only switch it off (together with all other warnings)
within cppumaker-generated headers, on the grounds that
-Wnon-virtual-dtor was considered a useful tool to find errors.
However, trying to compile
cppuhelper/qa/propertysetmixin/comp_propertysetmixin.cxx, I fear we have
to rethink the case: cppu::PropertySetMixin is part of the stable API
of OOo/URE, is a class template, and contains a non-virtual dtor and
virtual functions. Since it is part of the stable API, we cannot change
its dtor to be virtual (and even if we could, one could argue that that
would not be what one would want to do, but consider it a hack to work
around the warning). And since it is a template, we cannot disable the
warning locally---the warning is emitted at the end of each compilation
unit that includes cppuhelper/propertysetmixin.hxx, rather than from
within cppuhelper/propertysetmixin.hxx itself.
The only solution I see is to bite the bullet and globally disable
-Wnon-virtual-dtor.
Opinions?
-Stephan
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
