uic: use qOverload for ambiguous slots

qOverload was used only for ambiguous signals and slots with no
arguments. Connections to ambiguous slots made in widget designer's
signal/slot editor, lead to an unresolved ambiguity when compiling
the generated code in ui_xxx.h. One example is QLabel::setNum(), which
can either take a double or an int.

Always using qOverload is not an alternative, because signatures are
normalised. E.g. const QString & / QString can't be distinguished.

Add a map with all ambiguous signals and slots to customwidgetsinfo.cpp.
Hardcode the map, because uic lives in QtCore and can't access meta
objects of gui/widget classes.

Use this map in isAmbiguousSignal() and add isAmbiguousSlot().

Change OverloadUse enum into an enum class in language.cpp. Change
enum values to reflect the new condition for slots to use qOverload.

Rename existing enum values and remove default argument in
language::formatMemberFnPtr() to improve code readability.
Apply const T& syntax for all types starting with Q, except QSize and
QPoint.

Revert 94c16517b3f8f01309a89598e698931ef77d60db, which was a hack
forcing for QLCDNumber::display() to a string based connection.

Add a new baseline to tst_uic, to test the above.

Fixes: QTBUG-93413
Task-number: QTBUG-124241
Pick-to: 6.7 6.6 6.5 6.2
Change-Id: I49ccc1688cfc08970cce3e56adf18e5ac49a77e1
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

1 files changed, 78 insertions, 8 deletions

diff --git a/src/tools/uic/customwidgetsinfo.cpp b/src/tools/uic/customwidgetsinfo.cpp
index 169cdad618..6ec418634c 100644
--- a/src/tools/uic/customwidgetsinfo.cpp
+++ b/src/tools/uic/customwidgetsinfo.cpp
@@ -78,19 +78,89 @@ bool CustomWidgetsInfo::isCustomWidgetContainer(const QString &className) const
     return false;
 }
 
+// FIXME in 7.0 - QTBUG-124241
+// Remove isAmbiguous logic when widget slots have been disambiguated.
+bool CustomWidgetsInfo::isAmbiguous(const QString &className, const QString &signature,
+                                    QMetaMethod::MethodType type) const
+{
+    using TypeMap = QHash<QString, QMetaMethod::MethodType>;
+    struct AmbiguousInClass {
+        QLatin1StringView className;
+        TypeMap methodMap;
+    };
+
+    static const QList<AmbiguousInClass> ambiguousList = {
+
+        {"QAction"_L1, {{"triggered"_L1, QMetaMethod::Signal}}},
+        {"QCommandLinkButton"_L1, {{"triggered"_L1, QMetaMethod::Signal},
+                                   {"clicked"_L1, QMetaMethod::Signal}}},
+        {"QPushButton"_L1, {{"triggered"_L1, QMetaMethod::Signal},
+                            {"clicked"_L1, QMetaMethod::Signal}}},
+        {"QCheckBox"_L1, {{"triggered"_L1, QMetaMethod::Signal},
+                          {"clicked"_L1, QMetaMethod::Signal}}},
+        {"QRadioButton"_L1, {{"triggered"_L1, QMetaMethod::Signal},
+                             {"clicked"_L1, QMetaMethod::Signal}}},
+        {"QToolButton"_L1,  {{"triggered"_L1, QMetaMethod::Signal},
+                            {"clicked"_L1, QMetaMethod::Signal}}},
+        {"QLabel"_L1, {{"setNum"_L1, QMetaMethod::Slot}}},
+        {"QGraphicsView"_L1, {{"invalidateScene"_L1, QMetaMethod::Slot}}},
+        {"QListView"_L1, {{"dataChanged"_L1, QMetaMethod::Slot}}},
+        {"QColumnView"_L1, {{"dataChanged"_L1, QMetaMethod::Slot}}},
+        {"QListWidget"_L1, {{"dataChanged"_L1, QMetaMethod::Slot},
+                           {"scrollToItem"_L1, QMetaMethod::Slot}}},
+        {"QTableView"_L1, {{"dataChanged"_L1, QMetaMethod::Slot}}},
+        {"QTableWidget"_L1, {{"dataChanged"_L1, QMetaMethod::Slot},
+                            {"scrollToItem"_L1, QMetaMethod::Slot}}},
+        {"QTreeView"_L1, {{"dataChanged"_L1, QMetaMethod::Slot},
+                         {"verticalScrollbarValueChanged"_L1, QMetaMethod::Slot},
+                         {"expandRecursively"_L1, QMetaMethod::Slot}}},
+        {"QTreeWidget"_L1, {{"dataChanged"_L1, QMetaMethod::Slot},
+                           {"verticalScrollbarValueChanged"_L1, QMetaMethod::Slot}
+                           ,{"expandRecursively"_L1, QMetaMethod::Slot}
+                           ,{"scrollToItem"_L1, QMetaMethod::Slot}}},
+        {"QUndoView"_L1, {{"dataChanged"_L1, QMetaMethod::Slot}}},
+        {"QLCDNumber"_L1, {{"display"_L1, QMetaMethod::Slot}}},
+        {"QMenuBar"_L1, {{"setVisible"_L1, QMetaMethod::Slot}}},
+        {"QTextBrowser"_L1, {{"setSource"_L1, QMetaMethod::Slot}}},
+
+        /*
+        The following widgets with ambiguities are not used in the widget designer:
+
+        {"QSplashScreen"_L1, {{"showMessage"_L1, QMetaMethod::Slot}}},
+        {"QCompleter"_L1, {{"activated"_L1, QMetaMethod::Signal},
+                          {"highlighted"_L1, QMetaMethod::Signal}}},
+        {"QSystemTrayIcon"_L1, {{"showMessage"_L1, QMetaMethod::Slot}}},
+        {"QStyledItemDelegate"_L1, {{"closeEditor"_L1, QMetaMethod::Signal}}},
+        {"QErrorMessage"_L1, {{"showMessage"_L1, QMetaMethod::Slot}}},
+        {"QGraphicsDropShadowEffect"_L1, {{"setOffset"_L1, QMetaMethod::Slot}}},
+        {"QGraphicsScene"_L1, {{"invalidate"_L1, QMetaMethod::Slot}}},
+        {"QItemDelegate"_L1, {{"closeEditor"_L1, QMetaMethod::Signal}}}
+        */
+    };
+
+    for (auto it = ambiguousList.constBegin(); it != ambiguousList.constEnd(); ++it) {
+        if (extends(className, it->className)) {
+            const qsizetype pos = signature.indexOf(u'(');
+            const QString method = signature.left(pos);
+            const auto methodIterator = it->methodMap.find(method);
+            return methodIterator != it->methodMap.constEnd() && type == methodIterator.value();
+        }
+    }
+    return false;
+}
+
 // Is it ambiguous, resulting in different signals for Python
 // "QAbstractButton::clicked(checked=false)"
 bool CustomWidgetsInfo::isAmbiguousSignal(const QString &className,
                                           const QString &signalSignature) const
 {
-    if (signalSignature.startsWith(u"triggered") && extends(className, "QAction"))
-        return true;
-    if (signalSignature.startsWith(u"clicked(")
-        && extendsOneOf(className, {u"QCommandLinkButton"_s, u"QCheckBox"_s,
-                                    u"QPushButton"_s, u"QRadioButton"_s, u"QToolButton"_s})) {
-        return true;
-    }
-    return false;
+    return isAmbiguous(className, signalSignature, QMetaMethod::Signal);
+}
+
+bool CustomWidgetsInfo::isAmbiguousSlot(const QString &className,
+                                        const QString &signalSignature) const
+{
+    return isAmbiguous(className, signalSignature, QMetaMethod::Slot);
 }
 
 QString CustomWidgetsInfo::realClassName(const QString &className) const