Move QFutureInterfaceBase::cleanContinuation() to removed_api

This method isn't used anymore, but we can't remove it entirely for BC
reasons, because it was called from inline code.

Pick-to: 6.4
Change-Id: I9183c666c466030787ac7c2386706b50abf23eaa
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/corelib/compat/removed_api.cpp

@@ -169,6 +169,23 @@ QCalendar::QCalendar(QStringView name)
 QCalendar::QCalendar(QLatin1StringView name)
     : QCalendar(QAnyStringView{name}) {}
 
+#if QT_CONFIG(future)
+
+#include "qfutureinterface.h"
+#include "private/qfutureinterface_p.h"
+
+void QFutureInterfaceBase::cleanContinuation()
+{
+    if (!d)
+        return;
+
+    // This was called when the associated QPromise was being destroyed,
+    // but isn't used anymore.
+    QMutexLocker lock(&d->continuationMutex);
+    d->continuation = nullptr;
+}
+
+#endif // QT_CONFIG(future)
 
 #include "qhashfunctions.h"
 

src/corelib/thread/qfutureinterface.cpp

@@ -829,18 +829,6 @@ void QFutureInterfaceBase::setContinuation(std::function<void(const QFutureInter
     }
 }
 
-void QFutureInterfaceBase::cleanContinuation()
-{
-    if (!d)
-        return;
-
-    // This is called when the associated QPromise is being destroyed.
-    // Clear the continuation, to make sure it doesn't keep any ref-counted
-    // copies of this, so that the allocated memory can be freed.
-    QMutexLocker lock(&d->continuationMutex);
-    d->continuation = nullptr;
-}
-
 void QFutureInterfaceBase::runContinuation() const
 {
     QMutexLocker lock(&d->continuationMutex);

src/corelib/thread/qfutureinterface.h

@@ -183,7 +183,9 @@ protected:
     void setContinuation(std::function<void(const QFutureInterfaceBase &)> func);
     void setContinuation(std::function<void(const QFutureInterfaceBase &)> func,
                          QFutureInterfaceBasePrivate *continuationFutureData);
+#if QT_CORE_REMOVED_SINCE(6, 4)
     void cleanContinuation();
+#endif
     void runContinuation() const;
 
     void setLaunchAsync(bool value);