Re: [dev] warnings01: -Wnon-virtual-dtor
Nikolai Pretzell wrote: Hi Stephan and all, 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. Mhmm. Why not make the d'tor protected? As for compatibility, there should be no binary difference. The dtor is already protected. The problem is that changing a dtor from non-virtual to virtual affects the vtable (with some compilers, at least), so that calls through the vtable could fail after such an incompatible change. -Stephan Only the use would be constrained, but if cppu::PropertySetMixin is indeed used as a mixin, then in most cases (whenever it is not the first base class or any other base class is virtual, may be even whenever it is not the only base class) calling its d'tor directly would be a bug anyway. So maybe this does not break practical compatibility? You mentioned somewhere else, that making non-virtual d'tors protected does not solve the problem of the warning. But as it solves the defect, may be later versions of the compiler will not complain anymore? So we would at least keep the option to switch the warning on in future. Nikolai - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [dev] warnings01: -Wnon-virtual-dtor
Hi Stephan and all, 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. Mhmm. Why not make the d'tor protected? As for compatibility, there should be no binary difference. Only the use would be constrained, but if cppu::PropertySetMixin is indeed used as a mixin, then in most cases (whenever it is not the first base class or any other base class is virtual, may be even whenever it is not the only base class) calling its d'tor directly would be a bug anyway. So maybe this does not break practical compatibility? You mentioned somewhere else, that making non-virtual d'tors protected does not solve the problem of the warning. But as it solves the defect, may be later versions of the compiler will not complain anymore? So we would at least keep the option to switch the warning on in future. Nikolai - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [dev] warnings01: -Wnon-virtual-dtor
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]
Re: [dev] warnings01: -Wnon-virtual-dtor
Stephan Bergmann [EMAIL PROTECTED] writes: The only solution I see is to bite the bullet and globally disable -Wnon-virtual-dtor. Opinions? Hi Stephan, yes, I think so. But I'd still like to have this (and possibly other) warnings in an optional pedantic mode - to be run after warnings01 is finished, and inspected for cases where using a non-virtual dtor was not intentional. Cheers, -- Thorsten If you're not failing some of the time, you're not trying hard enough. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [dev] warnings01: -Wnon-virtual-dtor
Stephan Bergmann wrote: 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 Besides, all is not lost, as we can keep the corresponding warning on wntmsci10 enabled. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [dev] warnings01: -Wnon-virtual-dtor
Hi Malte, On Wed, Feb 01, 2006 at 13:00:24 +0100, Malte Timmermann wrote: When we are done with warnings01, we should have most warnings in the default warning level. People don't have to use wall=tr anymore, so this one could be a candidate for some extra warning in wall=tr +1 Eike -- OOo/SO Calc core developer. Number formatter stricken i18n transpositionizer. GnuPG key 0x293C05FD: 997A 4C60 CE41 0149 0DB3 9E96 2F1A D073 293C 05FD - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [dev] warnings01: -Wnon-virtual-dtor
Eike Rathke wrote: Hi Malte, On Wed, Feb 01, 2006 at 13:00:24 +0100, Malte Timmermann wrote: When we are done with warnings01, we should have most warnings in the default warning level. People don't have to use wall=tr anymore, so this one could be a candidate for some extra warning in wall=tr +1 Eike +-0, as the past has shown that any such mechanism that is not actively maintained over time becomes unusable through too much noise (see assertions; the current, pre-warnings01 wall=1; maybe also memory leaks at program termination time). -Stephan - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [dev] warnings01: -Wnon-virtual-dtor
Also +1 for switching this warning off from within idlc-generated headers only Malte. Tino Rachui - Sun Germany - Development - Software Engineer wrote: Stephan Bergmann wrote: 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. +1 for switching this warning off from within idlc-generated headers only -Tino - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [dev] warnings01: -Wnon-virtual-dtor
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. +1 for switching off this warnings in the generated header - Juergen Opinions? -Stephan - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [dev] warnings01: -Wnon-virtual-dtor
Stephan Bergmann [EMAIL PROTECTED] writes: 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. Is there really no feasible way to close that hole? I'm perfectly fine with the pragma solution, but still think it would be a good idea to forbid calling base class destructors (what about declaring a protected non-virtual destructor in XInterface?). Cheers, -- Thorsten If you're not failing some of the time, you're not trying hard enough. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [dev] warnings01: -Wnon-virtual-dtor
Thorsten Behrens wrote: Stephan Bergmann [EMAIL PROTECTED] writes: 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. Is there really no feasible way to close that hole? I'm perfectly fine with the pragma solution, but still think it would be a good idea to forbid calling base class destructors (what about declaring a protected non-virtual destructor in XInterface?). Good idea, thanks. Adding protected non-virtual dtor to all the interface classes generated by codemaker. -Stephan Cheers, - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [dev] warnings01: -Wnon-virtual-dtor
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. Should be sufficient using this pragma only in interface header files generated by cppumaker. 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. +1, switching off globally is really no good option. -Daniel - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [dev] warnings01: -Wnon-virtual-dtor
On 11/2/05, Stephan Bergmann [EMAIL PROTECTED] wrote: 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. I like the second option. So, +1 for using the pragma macro to locally suppress the warning within hdl headers. Because of the severity of overlooking this warning, turning it off globally would be IMO a very bad move. Kohei -- Kohei Yoshida OpenOffice.org Calc contributor http://kohei.us/ooo/ - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [dev] warnings01: -Wnon-virtual-dtor
Stephan Bergmann wrote: 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. +1 for switching this warning off from within idlc-generated headers only -Tino - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
