Long-live QT_REMOVAL_QT7_DEPRECATED_SINCE(major, minor)

... and QT_REMOVAL_QT8_DEPRECATED_SINCE.

Following up on the discussion from the Qt CS 2024 [0], this patch
introduces a new macro to mark the deprecated APIs that will be
removed in a specific major release. For now, add the macros
for Qt 7 and Qt 8.

The macro should be used instead of the regular
QT_DEPRECATED_SINCE(maj, min) for such type of APIs. The usage
is the same, as with the regular macro:

  #if QT_REMOVAL_QT7_DEPRECATED_SINCE(6, 9)
      QT_DEPRECATED_VERSION_X_6_9("The reason for the deprecation")
      void deprecatedFunc();
  #endif

The macro is basically a combination of QT_DEPRECATED_SINCE and
a comparison against a certain Qt major version.

[0]: https://wiki.qt.io/QtCS2024_Deprecate

Task-number: QTBUG-130024
Change-Id: I8efa1920d9d1524250bb00446aefffae65210340
Reviewed-by: Jarek Kobus <[email protected]>

src/corelib/global/qtdeprecationmarkers.h

@@ -64,6 +64,40 @@ QT_BEGIN_NAMESPACE
 #define QT_DEPRECATED_SINCE(major, minor) 0
 #endif
 
+/*
+    QT_REMOVAL_QT{VER}_DEPRECATED_SINCE(major, minor)
+
+    The macro should be used if the API is deprecated and should be removed
+    in the {VER} major release.
+
+    The \a major and \a minor parameters specify the deprecation version.
+
+    For now, we provide the macros to remove the deprecated APIs in Qt 7
+    and in Qt 8.
+
+    Example:
+
+    \code
+    #if QT_REMOVAL_QT7_DEPRECATED_SINCE(6, 9)
+        QT_DEPRECATED_VERSION_X_6_9("The reason for the deprecation")
+        void deprecatedFunc();
+    #endif
+    \endcode
+
+    The \c {deprecatedFunc()} function is deprecated since Qt 6.9, and will be
+    completely removed in Qt 7.0.
+*/
+#define QT_DEPRECATED_TO_BE_REMOVED_HELPER(dep_major, dep_minor, rem_major) \
+    (QT_DEPRECATED_SINCE(dep_major, dep_minor) && (QT_VERSION < QT_VERSION_CHECK(rem_major, 0, 0)))
+
+// For APIs that should be removed in Qt 7
+#define QT_REMOVAL_QT7_DEPRECATED_SINCE(major, minor) \
+    QT_DEPRECATED_TO_BE_REMOVED_HELPER(major, minor, 7)
+
+// For APIs that should be removed in Qt 8
+#define QT_REMOVAL_QT8_DEPRECATED_SINCE(major, minor) \
+    QT_DEPRECATED_TO_BE_REMOVED_HELPER(major, minor, 8)
+
 /*
   QT_DEPRECATED_VERSION(major, minor) and QT_DEPRECATED_VERSION_X(major, minor, text)
   outputs a deprecation warning if QT_WARN_DEPRECATED_UP_TO is equal to or greater