QStringConverter: mark QStringConverterBase as removed in Qt 7

It's an internal class containing the common content between
QStringConverter and QTextCodec (Qt5CoreCompat) so the latter didn't get
the new API from the former.

This allows us to remove the QStringConverter::Flags qdoc hack too.

Change-Id: Iacf32fb88e3c3d0ea369fffd153356cec308e3dd
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit c2fa41a081e4c9fe308dcd47283537eedf05c24a)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/corelib/text/qstringconverter.cpp

@@ -707,7 +707,7 @@ QByteArray QUtf8::convertFromUnicode(QStringView in)
     return result;
 }
 
-QByteArray QUtf8::convertFromUnicode(QStringView in, QStringConverterBase::State *state)
+QByteArray QUtf8::convertFromUnicode(QStringView in, QStringConverter::State *state)
 {
     QByteArray ba(3*in.size() +3, Qt::Uninitialized);
     char *end = convertFromUnicode(ba.data(), in, state);
@@ -1959,13 +1959,6 @@ static qsizetype toLatin1Len(qsizetype l) { return l + 1; }
 
 
 
-/*!
-  \class QStringConverterBase
-  \internal
-
-  Just a common base class for QStringConverter and QTextCodec
-*/
-
 /*!
     \class QStringConverter
     \inmodule QtCore
@@ -2159,7 +2152,7 @@ static bool nameMatch(const char *a, QAnyStringView b)
 // only derives from QStringConverter to get access to protected types
 struct QStringConverterICU : QStringConverter
 {
-    static void clear_function(QStringConverterBase::State *state) noexcept
+    static void clear_function(QStringConverter::State *state) noexcept
     {
         ucnv_close(static_cast<UConverter *>(state->d[0]));
         state->d[0] = nullptr;
@@ -2375,11 +2368,11 @@ struct QStringConverterICU : QStringConverter
     { return name.visit([](auto name) { return nul_terminate_impl(name); }); }
 
     static const QStringConverter::Interface *
-    make_icu_converter(QStringConverterBase::State *state, QAnyStringView name)
+    make_icu_converter(QStringConverter::State *state, QAnyStringView name)
     { return make_icu_converter(state, nul_terminate(name).data()); }
 
     static const QStringConverter::Interface *make_icu_converter(
-            QStringConverterBase::State *state,
+            QStringConverter::State *state,
             const char *name)
     {
         UErrorCode status = U_ZERO_ERROR;
@@ -2397,7 +2390,7 @@ struct QStringConverterICU : QStringConverter
         }
         state->d[1] = const_cast<char *>(persistentName);
         state->d[0] = conv;
-        state->flags |= QStringConverterBase::Flag::UsesIcu;
+        state->flags |= QStringConverter::Flag::UsesIcu;
         qsizetype maxCharSize = ucnv_getMaxCharSize(conv);
         state->clearFn = QStringConverterICU::clear_function;
         if (maxCharSize > 8 || maxCharSize < 1) {

src/corelib/text/qstringconverter_base.h

@@ -26,7 +26,11 @@ class QChar;
 class QByteArrayView;
 class QStringView;
 
+#if QT_VERSION < QT_VERSION_CHECK(7, 0, 0) && !defined(Q_QDOC) && !defined(QT_BOOTSTRAPPED)
 class QStringConverterBase
+#else
+class QStringConverter
+#endif
 {
 public:
     enum class Flag {
@@ -80,17 +84,19 @@ public:
     private:
         Q_DISABLE_COPY(State)
     };
+
+#if QT_VERSION < QT_VERSION_CHECK(7, 0, 0) && !defined(Q_QDOC) && !defined(QT_BOOTSTRAPPED)
 protected:
     QStringConverterBase() = default;
     ~QStringConverterBase() = default;
     QStringConverterBase(QStringConverterBase &&) = default;
     QStringConverterBase &operator=(QStringConverterBase &&) = default;
 };
-Q_DECLARE_OPERATORS_FOR_FLAGS(QStringConverterBase::Flags)
 
 class QStringConverter : public QStringConverterBase
 {
 public:
+#endif // Qt 6 compat for QStringConverterBase
 
     enum Encoding {
         Utf8,
@@ -106,18 +112,6 @@ public:
         System,
         LastEncoding = System
     };
-#ifdef Q_QDOC
-    // document the flags here
-    enum class Flag {
-        Default = 0,
-        Stateless = 0x1,
-        ConvertInvalidToNull = 0x2,
-        WriteBom = 0x4,
-        ConvertInitialBom = 0x8,
-        UsesIcu = 0x10,
-    };
-    Q_DECLARE_FLAGS(Flags, Flag)
-#endif
 
 protected:
 
@@ -182,6 +176,8 @@ private:
     Q_CORE_EXPORT static const Interface encodingInterfaces[Encoding::LastEncoding + 1];
 };
 
+Q_DECLARE_OPERATORS_FOR_FLAGS(QStringConverter::Flags)
+
 QT_END_NAMESPACE
 
 #endif

src/corelib/text/qstringconverter_p.h

@@ -43,7 +43,7 @@ struct QLatin1
     }
 
     static QChar *convertToUnicode(QChar *dst, QByteArrayView in,
-                                   [[maybe_unused]] QStringConverterBase::State *state) noexcept
+                                   [[maybe_unused]] QStringConverter::State *state) noexcept
     {
         Q_ASSERT(state);
 
@@ -321,7 +321,7 @@ struct QUtf8
     static char16_t *convertToUnicode(char16_t *dst, QByteArrayView in, QStringConverter::State *state);
 
     Q_CORE_EXPORT static QByteArray convertFromUnicode(QStringView in);
-    Q_CORE_EXPORT static QByteArray convertFromUnicode(QStringView in, QStringConverterBase::State *state);
+    Q_CORE_EXPORT static QByteArray convertFromUnicode(QStringView in, QStringConverter::State *state);
     static char *convertFromUnicode(char *out, QStringView in, QStringConverter::State *state);
     Q_CORE_EXPORT static char *convertFromLatin1(char *out, QLatin1StringView in);
     struct ValidUtf8Result {