Merge #18914: refactor: Apply override specifier consistently

d044e0e refactor: Remove override for final overriders (Hennadii Stepanov)
1551cea refactor: Use override for non-final overriders (Hennadii Stepanov)

Pull request description:

  Two commits are split out from #16710 to make reviewing [easier](bitcoin/bitcoin#16710 (comment)).

  From [C++ FAQ](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines.html#c128-virtual-functions-should-specify-exactly-one-of-virtual-override-or-final):
  > C.128: Virtual functions should specify exactly one of virtual, override, or final
  > **Reason** Readability. Detection of mistakes. Writing explicit `virtual`, `override`, or `final` is self-documenting and enables the compiler to catch mismatch of types and/or names between base and derived classes. However, writing more than one of these three is both redundant and a potential source of errors.

ACKs for top commit:
  practicalswift:
    ACK d044e0e: consistent use of `override` prevents bugs + patch looks correct + Travis happy
  MarcoFalke:
    ACK d044e0e, based on my understanding that adding `override` or `final` to a function must always be correct, unless it doesn't compile!?
  vasild:
    ACK d044e0e

Tree-SHA512: 245fd9b99b8b5cbf8694061f892cb3435f3378c97ebed9f9401ce86d21890211f2234bcc39c9f0f79a4d2806cb31bf8ce41a0f9c2acef4f3a2ac5beca6b077cf

Author: MarcoFalke

src/interfaces/chain.cpp

@@ -127,7 +127,7 @@ class RpcHandlerImpl : public Handler
         ::tableRPC.appendCommand(m_command.name, &m_command);
     }
 
-    void disconnect() override final
+    void disconnect() final
     {
         if (m_wrapped_command) {
             m_wrapped_command = nullptr;

src/qt/addressbookpage.cpp

@@ -35,7 +35,7 @@ class AddressBookSortFilterProxyModel final : public QSortFilterProxyModel
     }
 
 protected:
-    bool filterAcceptsRow(int row, const QModelIndex& parent) const
+    bool filterAcceptsRow(int row, const QModelIndex& parent) const override
     {
         auto model = sourceModel();
         auto label = model->index(row, AddressTableModel::Label, parent);

src/qt/addressbookpage.h

@@ -45,7 +45,7 @@ class AddressBookPage : public QDialog
     const QString &getReturnValue() const { return returnValue; }
 
 public Q_SLOTS:
-    void done(int retval);
+    void done(int retval) override;
 
 private:
     Ui::AddressBookPage *ui;

src/qt/addresstablemodel.h

@@ -52,14 +52,14 @@ class AddressTableModel : public QAbstractTableModel
 
     /** @name Methods overridden from QAbstractTableModel
         @{*/
-    int rowCount(const QModelIndex &parent) const;
-    int columnCount(const QModelIndex &parent) const;
-    QVariant data(const QModelIndex &index, int role) const;
-    bool setData(const QModelIndex &index, const QVariant &value, int role);
-    QVariant headerData(int section, Qt::Orientation orientation, int role) const;
-    QModelIndex index(int row, int column, const QModelIndex &parent) const;
-    bool removeRows(int row, int count, const QModelIndex &parent = QModelIndex());
-    Qt::ItemFlags flags(const QModelIndex &index) const;
+    int rowCount(const QModelIndex &parent) const override;
+    int columnCount(const QModelIndex &parent) const override;
+    QVariant data(const QModelIndex &index, int role) const override;
+    bool setData(const QModelIndex &index, const QVariant &value, int role) override;
+    QVariant headerData(int section, Qt::Orientation orientation, int role) const override;
+    QModelIndex index(int row, int column, const QModelIndex &parent) const override;
+    bool removeRows(int row, int count, const QModelIndex &parent = QModelIndex()) override;
+    Qt::ItemFlags flags(const QModelIndex &index) const override;
     /*@}*/
 
     /* Add an address to the model.

src/qt/askpassphrasedialog.h

@@ -32,7 +32,7 @@ class AskPassphraseDialog : public QDialog
     explicit AskPassphraseDialog(Mode mode, QWidget *parent, SecureString* passphrase_out = nullptr);
     ~AskPassphraseDialog();
 
-    void accept();
+    void accept() override;
 
     void setModel(WalletModel *model);
 
@@ -49,8 +49,8 @@ private Q_SLOTS:
     void toggleShowPassword(bool);
 
 protected:
-    bool event(QEvent *event);
-    bool eventFilter(QObject *object, QEvent *event);
+    bool event(QEvent *event) override;
+    bool eventFilter(QObject *object, QEvent *event) override;
 };
 
 #endif // BITCOIN_QT_ASKPASSPHRASEDIALOG_H

src/qt/bantablemodel.h

@@ -56,16 +56,17 @@ class BanTableModel : public QAbstractTableModel
 
     /** @name Methods overridden from QAbstractTableModel
         @{*/
-    int rowCount(const QModelIndex &parent) const;
-    int columnCount(const QModelIndex &parent) const;
-    QVariant data(const QModelIndex &index, int role) const;
-    QVariant headerData(int section, Qt::Orientation orientation, int role) const;
-    QModelIndex index(int row, int column, const QModelIndex &parent) const;
-    Qt::ItemFlags flags(const QModelIndex &index) const;
-    void sort(int column, Qt::SortOrder order);
-    bool shouldShow();
+    int rowCount(const QModelIndex &parent) const override;
+    int columnCount(const QModelIndex &parent) const override;
+    QVariant data(const QModelIndex &index, int role) const override;
+    QVariant headerData(int section, Qt::Orientation orientation, int role) const override;
+    QModelIndex index(int row, int column, const QModelIndex &parent) const override;
+    Qt::ItemFlags flags(const QModelIndex &index) const override;
+    void sort(int column, Qt::SortOrder order) override;
     /*@}*/
 
+    bool shouldShow();
+
 public Q_SLOTS:
     void refresh();
 

src/qt/bitcoinaddressvalidator.h

@@ -17,7 +17,7 @@ class BitcoinAddressEntryValidator : public QValidator
 public:
     explicit BitcoinAddressEntryValidator(QObject *parent);
 
-    State validate(QString &input, int &pos) const;
+    State validate(QString &input, int &pos) const override;
 };
 
 /** Bitcoin address widget validator, checks for a valid bitcoin address.
@@ -29,7 +29,7 @@ class BitcoinAddressCheckValidator : public QValidator
 public:
     explicit BitcoinAddressCheckValidator(QObject *parent);
 
-    State validate(QString &input, int &pos) const;
+    State validate(QString &input, int &pos) const override;
 };
 
 #endif // BITCOIN_QT_BITCOINADDRESSVALIDATOR_H

src/qt/bitcoinamountfield.cpp

@@ -31,7 +31,7 @@ class AmountSpinBox: public QAbstractSpinBox
         connect(lineEdit(), &QLineEdit::textEdited, this, &AmountSpinBox::valueChanged);
     }
 
-    QValidator::State validate(QString &text, int &pos) const
+    QValidator::State validate(QString &text, int &pos) const override
     {
         if(text.isEmpty())
             return QValidator::Intermediate;
@@ -41,7 +41,7 @@ class AmountSpinBox: public QAbstractSpinBox
         return valid ? QValidator::Intermediate : QValidator::Invalid;
     }
 
-    void fixup(QString &input) const
+    void fixup(QString &input) const override
     {
         bool valid;
         CAmount val;
@@ -87,7 +87,7 @@ class AmountSpinBox: public QAbstractSpinBox
         m_max_amount = value;
     }
 
-    void stepBy(int steps)
+    void stepBy(int steps) override
     {
         bool valid = false;
         CAmount val = value(&valid);
@@ -114,7 +114,7 @@ class AmountSpinBox: public QAbstractSpinBox
         singleStep = step;
     }
 
-    QSize minimumSizeHint() const
+    QSize minimumSizeHint() const override
     {
         if(cachedMinimumSizeHint.isEmpty())
         {
@@ -175,7 +175,7 @@ class AmountSpinBox: public QAbstractSpinBox
     }
 
 protected:
-    bool event(QEvent *event)
+    bool event(QEvent *event) override
     {
         if (event->type() == QEvent::KeyPress || event->type() == QEvent::KeyRelease)
         {
@@ -190,7 +190,7 @@ class AmountSpinBox: public QAbstractSpinBox
         return QAbstractSpinBox::event(event);
     }
 
-    StepEnabled stepEnabled() const
+    StepEnabled stepEnabled() const override
     {
         if (isReadOnly()) // Disable steps when AmountSpinBox is read-only
             return StepNone;

src/qt/bitcoinamountfield.h

@@ -70,7 +70,7 @@ class BitcoinAmountField: public QWidget
 
 protected:
     /** Intercept focus-in event and ',' key presses */
-    bool eventFilter(QObject *object, QEvent *event);
+    bool eventFilter(QObject *object, QEvent *event) override;
 
 private:
     AmountSpinBox *amount;

src/qt/bitcoingui.h

@@ -99,12 +99,12 @@ class BitcoinGUI : public QMainWindow
     void unsubscribeFromCoreSignals();
 
 protected:
-    void changeEvent(QEvent *e);
-    void closeEvent(QCloseEvent *event);
-    void showEvent(QShowEvent *event);
-    void dragEnterEvent(QDragEnterEvent *event);
-    void dropEvent(QDropEvent *event);
-    bool eventFilter(QObject *object, QEvent *event);
+    void changeEvent(QEvent *e) override;
+    void closeEvent(QCloseEvent *event) override;
+    void showEvent(QShowEvent *event) override;
+    void dragEnterEvent(QDragEnterEvent *event) override;
+    void dropEvent(QDropEvent *event) override;
+    bool eventFilter(QObject *object, QEvent *event) override;
 
 private:
     interfaces::Node& m_node;
@@ -325,7 +325,7 @@ class UnitDisplayStatusBarControl : public QLabel
 
 protected:
     /** So that it responds to left-button clicks */
-    void mousePressEvent(QMouseEvent *event);
+    void mousePressEvent(QMouseEvent *event) override;
 
 private:
     OptionsModel *optionsModel;