how to remove those compiler warnings

[ollydbg]

Code

include\editorbase.h:36:22: warning: 'virtual void EditorBase::operator=(const EditorBase&)' was hidden [-Woverloaded-virtual]
include\cbeditor.h:70:22: warning:   by 'virtual void cbEditor::operator=(const cbEditor&)' [-Woverloaded-virtual]

I see a lot of such warnings, can we remove them?

Thanks.

MinGW GCC 4.6.3.

[oBFusCATed]

There is no point in operator= being virtual. You can try to remove the virtuals and see what happens

[MortenMacFly]

There is no point in operator= being virtual. You can try to remove the virtuals and see what happens

Why not? If you specialise EditorBase you should ensure also to specialise this operator, don't you?

[jarod42]

Code

class DerivedClass : public BaseClass
{
using BaseClass::hiddenFunction;

// other stuff.
};

should remove the warnings.

but I agree that

Code

DerivedClass::operator =(const BaseClass&)

is strange

[oBFusCATed]

Why not? If you specialise EditorBase you should ensure also to specialise this operator, don't you?

It is quite more complex.
Here is a thorough explanation: http://icu-project.org/docs/papers/cpp_report/the_assignment_operator_revisited.html (scroll to the virtual assignment).

Remember clone()? This is the polymorphic copy constructor. If you need polymorphic copy on a group of related classes, you define a virtual function called clone() and every class in the tree overrides it to call his own copy constructor. You can’t just call X’s copy constructor for the same reason you can’t just call X’s assignment operator.

And this is an explanation for the warning: http://www.parashift.com/c++-faq-lite/strange-inheritance.html#faq-23.9
It happens because the compiler always generates Derived& operator=(Derived &p) no matter if there is Base& operator=(Base &p) (virtual or not).

p.s. I suppose the best we could do is to make operator= an unimplemented private function.

[oBFusCATed]

p.s. I suppose the best we could do is to make operator= an unimplemented private function.

Turns out that the script bindings are using the operator=, but the versions in EditorBase and cbEditor both throw an exception,
so the second best thing is to remove the virtual keyword in their declarations.

EditorBase:
virtual void operator=(const EditorBase& /*rhs*/){ cbThrow(_T("Can't assign an EditorBase* !!!")); }
cbEditor:
virtual void operator=(const cbEditor& /*rhs*/){ cbThrow(_T("Can't assign an cbEditor* !!!")); }

No inheritance is used here...

[ollydbg]

p.s. I suppose the best we could do is to make operator= an unimplemented private function.

Turns out that the script bindings are using the operator=, but the versions in EditorBase and cbEditor both throw an exception,
so the second best thing is to remove the virtual keyword in their declarations.

EditorBase:
virtual void operator=(const EditorBase& /*rhs*/){ cbThrow(_T("Can't assign an EditorBase* !!!")); }
cbEditor:
virtual void operator=(const cbEditor& /*rhs*/){ cbThrow(_T("Can't assign an cbEditor* !!!")); }

No inheritance is used here...

Ok, remove the "virtual" keyword, then there is not such warning now.

I see another kind of warning:

include\cbplugin.h:169:22: warning: 'virtual bool cbPlugin::BuildToolBar(wxToolBar*, int&)' was hidden [-Woverloaded-virtual]
include\cbplugin.h:408:22: warning:   by 'virtual bool cbDebuggerPlugin::BuildToolBar(wxToolBar*)' [-Woverloaded-virtual]

Here:in cbPlugin:

Code

        virtual bool BuildToolBar(wxToolBar* toolBar) = 0;
        virtual bool BuildToolBar(wxToolBar* toolBar, int &priority) { priority = 50; return BuildToolBar(toolBar); }

and in derived class:

Code

virtual bool BuildToolBar(wxToolBar* toolBar);

[oBFusCATed]

This one should be fixed using "using bla bla".

[ptDev]

I see another kind of warning:

include\cbplugin.h:169:22: warning: 'virtual bool cbPlugin::BuildToolBar(wxToolBar*, int&)' was hidden [-Woverloaded-virtual]
include\cbplugin.h:408:22: warning:   by 'virtual bool cbDebuggerPlugin::BuildToolBar(wxToolBar*)' [-Woverloaded-virtual]

Here:in cbPlugin:

Code

        virtual bool BuildToolBar(wxToolBar* toolBar) = 0;
        virtual bool BuildToolBar(wxToolBar* toolBar, int &priority) { priority = 50; return BuildToolBar(toolBar); }

and in derived class:

Code

virtual bool BuildToolBar(wxToolBar* toolBar);

Does cbPlugin::BuildToolBar(wxToolBar* toolBar, int &priority) really need to be virtual? I would fix that by making it non-virtual. Otherwise, you lose the method (or need to re-implement it) in the derived class.

[jarod42]

I would suggest to rename the method to avoid future similar warnings for derived class.

[oBFusCATed]

ptDev: If it is not virtual how would you change the priority?
jarod42: This is an option, too, but someone should come up with a good name - always a hard task.

[jarod42]

Code

virtual int getPriority() const { return 50; }

or

Code

virtual void changePriority(int& priority) { priority = 50; }

and then

Code

bool BuildToolBarAndSetPriority(wxToolBar* toolBar, int &priority)
{
  changePriority(priority);
  return BuildToolBar(toolBar);
}

should be cleaner, I think.

[ollydbg]

Some days later, I rethink it. Now. follow jarod42's advice
The code

Code

ToolbarInfo MainFrame::DoAddPluginToolbar(cbPlugin* plugin)
{
    ToolbarInfo info;
    info.toolbar = Manager::Get()->CreateEmptyToolbar();
    info.priority = 50;
    if (plugin->BuildToolBar(info.toolbar, info.priority))
    {
        SetToolBar(0);
        InitToolbar(info.toolbar);

becomes like below:

In base class, add a function:

Code

virtual int GetToolBarPriority() { return 50; }

If some derived plugin class need to implement some other priority values, they should override their own.

Code

ToolbarInfo MainFrame::DoAddPluginToolbar(cbPlugin* plugin)
{
    ToolbarInfo info;
    info.toolbar = Manager::Get()->CreateEmptyToolbar();
    //info.priority = 50;
    if (plugin->BuildToolbar(info.toolbar))
    {
        info.priority = plugin->GetToolBarPriority();
        SetToolBar(0);
        InitToolbar(info.toolbar);

Is it right?

[oBFusCATed]

Try it and see if it works...

[ollydbg]

Try it and see if it works...

I test it, and it works just fine.

Is the function name: GetToolBarPriority()  OK?

Ok to commit? (Include the change that remove the "virtual" keyword in operator=).