QSqlDriver: use Q_DECLARE_PUBLIC/Q_DECLARE_PRIVATE

406c8ef6e67da introduced deriving the private SQL driver classes from
QSqlDriverPrivate. However, the drivers continued to keep their own
pointer to the private class, even though QObject provides the same
pointer. Worse yet, the private class is allocated too late and not
even passed to QSqlDriver. The result is that QSqlDriver allocates
a separate instance of QSqlDriverPrivate. This is likely to cause
all kinds of chaos.

The private class needs to be allocated in time pass it to QSqlDriver
which passes it on to QObject.

This commit covers the the base class and drivers:
    ibase
    mysql
    odbc
    psql
    sqlite
    tds

Fixes for the remaining drivers will follow.

Change-Id: Id8e7ec4205b0ca6cd00bd022c9cd24f137089245
Reviewed-by: Andy Shaw <andy.shaw@digia.com>

2 files changed, 33 insertions, 20 deletions

diff --git a/src/sql/drivers/psql/qsql_psql.cpp b/src/sql/drivers/psql/qsql_psql.cpp
index aed0a11218..9331f5c371 100644
--- a/src/sql/drivers/psql/qsql_psql.cpp
+++ b/src/sql/drivers/psql/qsql_psql.cpp
@@ -124,9 +124,9 @@ inline void qPQfreemem(void *buffer)
 
 class QPSQLDriverPrivate : public QSqlDriverPrivate
 {
+    Q_DECLARE_PUBLIC(QPSQLDriver)
 public:
-    QPSQLDriverPrivate(QPSQLDriver *qq) : QSqlDriverPrivate(),
-        q(qq),
+    QPSQLDriverPrivate() : QSqlDriverPrivate(),
         connection(0),
         isUtf8(false),
         pro(QPSQLDriver::Version6),
@@ -135,7 +135,6 @@ public:
         hasBackslashEscape(false)
     { dbmsType = PostgreSQL; }
 
-    QPSQLDriver *q;
     PGconn *connection;
     bool isUtf8;
     QPSQLDriver::Protocol pro;
@@ -179,10 +178,11 @@ void QPSQLDriverPrivate::appendTables(QStringList &tl, QSqlQuery &t, QChar type)
 
 PGresult * QPSQLDriverPrivate::exec(const char * stmt) const
 {
+    Q_Q(const QPSQLDriver);
     PGresult *result = PQexec(connection, stmt);
     if (seid.size() && !pendingNotifyCheck) {
         pendingNotifyCheck = true;
-        QMetaObject::invokeMethod(q, "_q_handleNotification", Qt::QueuedConnection, Q_ARG(int,0));
+        QMetaObject::invokeMethod(const_cast<QPSQLDriver*>(q), "_q_handleNotification", Qt::QueuedConnection, Q_ARG(int,0));
     }
     return result;
 }
@@ -205,7 +205,11 @@ public:
 
     QString fieldSerial(int i) const { return QLatin1Char('$') + QString::number(i + 1); }
     void deallocatePreparedStmt();
-    const QPSQLDriverPrivate * privDriver() const {Q_Q(const QPSQLResult); return reinterpret_cast<const QPSQLDriver *>(q->driver())->d; }
+    const QPSQLDriverPrivate * privDriver() const
+    {
+        Q_Q(const QPSQLResult);
+        return reinterpret_cast<const QPSQLDriver *>(q->driver())->d_func();
+    }
 
     PGresult *result;
     int currentSize;
@@ -767,15 +771,14 @@ QPSQLDriver::Protocol QPSQLDriverPrivate::getPSQLVersion()
 }
 
 QPSQLDriver::QPSQLDriver(QObject *parent)
-    : QSqlDriver(parent)
+    : QSqlDriver(*new QPSQLDriverPrivate, parent)
 {
-    init();
 }
 
 QPSQLDriver::QPSQLDriver(PGconn *conn, QObject *parent)
-    : QSqlDriver(parent)
+    : QSqlDriver(*new QPSQLDriverPrivate, parent)
 {
-    init();
+    Q_D(QPSQLDriver);
     d->connection = conn;
     if (conn) {
         d->pro = d->getPSQLVersion();
@@ -785,24 +788,22 @@ QPSQLDriver::QPSQLDriver(PGconn *conn, QObject *parent)
     }
 }
 
-void QPSQLDriver::init()
-{
-    d = new QPSQLDriverPrivate(this);
-}
-
 QPSQLDriver::~QPSQLDriver()
 {
+    Q_D(QPSQLDriver);
     if (d->connection)
         PQfinish(d->connection);
 }
 
 QVariant QPSQLDriver::handle() const
 {
+    Q_D(const QPSQLDriver);
     return QVariant::fromValue(d->connection);
 }
 
 bool QPSQLDriver::hasFeature(DriverFeature f) const
 {
+    Q_D(const QPSQLDriver);
     switch (f) {
     case Transactions:
     case QuerySize:
@@ -849,6 +850,7 @@ bool QPSQLDriver::open(const QString & db,
                         int port,
                         const QString& connOpts)
 {
+    Q_D(QPSQLDriver);
     if (isOpen())
         close();
     QString connectString;
@@ -891,6 +893,7 @@ bool QPSQLDriver::open(const QString & db,
 
 void QPSQLDriver::close()
 {
+    Q_D(QPSQLDriver);
     if (isOpen()) {
 
         d->seid.clear();
@@ -915,6 +918,7 @@ QSqlResult *QPSQLDriver::createResult() const
 
 bool QPSQLDriver::beginTransaction()
 {
+    Q_D(const QPSQLDriver);
     if (!isOpen()) {
         qWarning("QPSQLDriver::beginTransaction: Database not open");
         return false;
@@ -932,6 +936,7 @@ bool QPSQLDriver::beginTransaction()
 
 bool QPSQLDriver::commitTransaction()
 {
+    Q_D(QPSQLDriver);
     if (!isOpen()) {
         qWarning("QPSQLDriver::commitTransaction: Database not open");
         return false;
@@ -965,6 +970,7 @@ bool QPSQLDriver::commitTransaction()
 
 bool QPSQLDriver::rollbackTransaction()
 {
+    Q_D(QPSQLDriver);
     if (!isOpen()) {
         qWarning("QPSQLDriver::rollbackTransaction: Database not open");
         return false;
@@ -982,6 +988,7 @@ bool QPSQLDriver::rollbackTransaction()
 
 QStringList QPSQLDriver::tables(QSql::TableType type) const
 {
+    Q_D(const QPSQLDriver);
     QStringList tl;
     if (!isOpen())
         return tl;
@@ -989,9 +996,9 @@ QStringList QPSQLDriver::tables(QSql::TableType type) const
     t.setForwardOnly(true);
 
     if (type & QSql::Tables)
-        d->appendTables(tl, t, QLatin1Char('r'));
+        const_cast<QPSQLDriverPrivate*>(d)->appendTables(tl, t, QLatin1Char('r'));
     if (type & QSql::Views)
-        d->appendTables(tl, t, QLatin1Char('v'));
+        const_cast<QPSQLDriverPrivate*>(d)->appendTables(tl, t, QLatin1Char('v'));
     if (type & QSql::SystemTables) {
         t.exec(QLatin1String("select relname from pg_class where (relkind = 'r') "
                 "and (relname like 'pg_%') "));
@@ -1013,6 +1020,7 @@ static void qSplitTableName(QString &tablename, QString &schema)
 
 QSqlIndex QPSQLDriver::primaryIndex(const QString& tablename) const
 {
+    Q_D(const QPSQLDriver);
     QSqlIndex idx(tablename);
     if (!isOpen())
         return idx;
@@ -1094,6 +1102,7 @@ QSqlIndex QPSQLDriver::primaryIndex(const QString& tablename) const
 
 QSqlRecord QPSQLDriver::record(const QString& tablename) const
 {
+    Q_D(const QPSQLDriver);
     QSqlRecord info;
     if (!isOpen())
         return info;
@@ -1231,6 +1240,7 @@ QSqlRecord QPSQLDriver::record(const QString& tablename) const
 
 QString QPSQLDriver::formatValue(const QSqlField &field, bool trimStrings) const
 {
+    Q_D(const QPSQLDriver);
     QString r;
     if (field.isNull()) {
         r = QLatin1String("NULL");
@@ -1326,16 +1336,19 @@ QString QPSQLDriver::escapeIdentifier(const QString &identifier, IdentifierType)
 
 bool QPSQLDriver::isOpen() const
 {
+    Q_D(const QPSQLDriver);
     return PQstatus(d->connection) == CONNECTION_OK;
 }
 
 QPSQLDriver::Protocol QPSQLDriver::protocol() const
 {
+    Q_D(const QPSQLDriver);
     return d->pro;
 }
 
 bool QPSQLDriver::subscribeToNotification(const QString &name)
 {
+    Q_D(QPSQLDriver);
     if (!isOpen()) {
         qWarning("QPSQLDriver::subscribeToNotificationImplementation: database not open.");
         return false;
@@ -1373,6 +1386,7 @@ bool QPSQLDriver::subscribeToNotification(const QString &name)
 
 bool QPSQLDriver::unsubscribeFromNotification(const QString &name)
 {
+    Q_D(QPSQLDriver);
     if (!isOpen()) {
         qWarning("QPSQLDriver::unsubscribeFromNotificationImplementation: database not open.");
         return false;
@@ -1404,11 +1418,13 @@ bool QPSQLDriver::unsubscribeFromNotification(const QString &name)
 
 QStringList QPSQLDriver::subscribedToNotifications() const
 {
+    Q_D(const QPSQLDriver);
     return d->seid;
 }
 
 void QPSQLDriver::_q_handleNotification(int)
 {
+    Q_D(QPSQLDriver);
     d->pendingNotifyCheck = false;
     PQconsumeInput(d->connection);
 
diff --git a/src/sql/drivers/psql/qsql_psql_p.h b/src/sql/drivers/psql/qsql_psql_p.h
index a20b9de3ef..5f4aa68b9e 100644
--- a/src/sql/drivers/psql/qsql_psql_p.h
+++ b/src/sql/drivers/psql/qsql_psql_p.h
@@ -103,6 +103,7 @@ class QPSQLDriverPrivate;
 class Q_EXPORT_SQLDRIVER_PSQL QPSQLDriver : public QSqlDriver
 {
     friend class QPSQLResultPrivate;
+    Q_DECLARE_PRIVATE(QPSQLDriver)
 
     Q_OBJECT
 public:
@@ -155,10 +156,6 @@ protected:
 
 private Q_SLOTS:
     void _q_handleNotification(int);
-
-private:
-    void init();
-    QPSQLDriverPrivate *d;
 };
 
 QT_END_NAMESPACE