compilerplugin: check that necessary Window subclasses have a dispose method

i.e. the ones that declare any VclPtr fields

Change-Id: I7adfc3b3b190a2ede60bfccd08f85a269fae33ca

compilerplugins/clang/vclwidgets.cxx

@@ -31,6 +31,8 @@ public:
 
     virtual void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
 
+    bool VisitCXXRecordDecl(const CXXRecordDecl * decl);
+
     bool VisitFieldDecl(const FieldDecl * decl);
 
     bool VisitParmVarDecl(ParmVarDecl const * decl);
@@ -76,6 +78,44 @@ bool isPointerToWindowSubclass(const QualType& pType) {
     return isDerivedFromWindow(recordDecl);
 }
 
+bool VCLWidgets::VisitCXXRecordDecl(const CXXRecordDecl * recordDecl) {
+    if (ignoreLocation(recordDecl)) {
+        return true;
+    }
+    if (!recordDecl->isCompleteDefinition())
+        return true;
+    // check if this field is derived from Window
+    if (!isDerivedFromWindow(recordDecl)) {
+        return true;
+    }
+    bool foundVclPtr = false;
+    for(auto fieldDecl : recordDecl->fields()) {
+        if (fieldDecl->getType().getAsString().find("VclPtr")==0) {
+           foundVclPtr = true;
+           break;
+        }
+    }
+    if (!foundVclPtr) {
+        return true;
+    }
+    bool foundDispose = false;
+    for(auto methodDecl : recordDecl->methods()) {
+        if (methodDecl->isInstance() && methodDecl->param_size()==0 && methodDecl->getNameAsString() == "dispose") {
+           foundDispose = true;
+           break;
+        }
+    }
+    if (!foundDispose) {
+        report(
+            DiagnosticsEngine::Warning,
+            "vcl::Window subclass with VclPtr members should declare a dispose() method.",
+            recordDecl->getLocation())
+          << recordDecl->getSourceRange();
+    }
+    return true;
+}
+
+
 bool VCLWidgets::VisitFieldDecl(const FieldDecl * fieldDecl) {
     if (ignoreLocation(fieldDecl)) {
         return true;

include/vcl/combobox.hxx

@@ -91,6 +91,7 @@ protected:
     bool            IsDropDownBox() const { return mpFloatWin ? true : false; }
 
     virtual void    FillLayoutData() const SAL_OVERRIDE;
+    virtual void    dispose() SAL_OVERRIDE;
 public:
     explicit        ComboBox( vcl::Window* pParent, WinBits nStyle = 0 );
     explicit        ComboBox( vcl::Window* pParent, const ResId& );

include/vcl/dialog.hxx

@@ -62,6 +62,7 @@ private:
 protected:
     using Window::ImplInit;
     SAL_DLLPRIVATE void    ImplInit( vcl::Window* pParent, WinBits nStyle );
+    virtual        void    dispose() SAL_OVERRIDE;
 
 public:
     SAL_DLLPRIVATE bool    IsInClose() const { return mbInClose; }

include/vcl/layout.hxx

@@ -620,6 +620,8 @@ private:
     };
 
     VclPtr<EventBoxHelper> m_aEventBoxHelper;
+protected:
+    virtual void dispose() SAL_OVERRIDE;
 public:
     VclEventBox(vcl::Window* pParent)
         : VclBin(pParent)

vcl/source/control/combobox.cxx

@@ -78,6 +78,12 @@ ComboBox::~ComboBox()
     delete mpBtn;
 }
 
+void ComboBox::dispose()
+{
+    mpSubEdit.disposeAndClear();
+    Edit::dispose();
+}
+
 void ComboBox::ImplInitComboBoxData()
 {
     mpSubEdit.disposeAndClear();

vcl/source/window/dialog.cxx

@@ -542,6 +542,13 @@ Dialog::~Dialog()
     mpDialogImpl = NULL;
 }
 
+void Dialog::dispose()
+{
+    mpActionArea.disposeAndClear();
+    mpContentArea.disposeAndClear();
+    SystemWindow::dispose();
+}
+
 IMPL_LINK_NOARG(Dialog, ImplAsyncCloseHdl)
 {
     Close();

vcl/source/window/layout.cxx

@@ -1878,6 +1878,12 @@ void VclEventBox::Command(const CommandEvent&)
     //discard events by default to block them reaching children
 }
 
+void VclEventBox::dispose()
+{
+    m_aEventBoxHelper.disposeAndClear();
+    VclBin::dispose();
+}
+
 void VclSizeGroup::trigger_queue_resize()
 {
     //sufficient to trigger one widget to trigger all of them