QMetaObjectPrivate: Add firstMethod

QMetaObject::indexfOfMethod returns the method corresponding to a
specific signature. In QML, we however only want any of the methods with
a given name (and do overload resolution at a later point).
For this usecase this patch introduces the internal
QMetaObject::firstMethod function.

Change-Id: Ie3820354edffb273c4cbe1399201a955ebe79344
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

2 files changed, 19 insertions, 0 deletions

diff --git a/src/corelib/kernel/qmetaobject.cpp b/src/corelib/kernel/qmetaobject.cpp
index fe6b4075ef..bdd2af1a2e 100644
--- a/src/corelib/kernel/qmetaobject.cpp
+++ b/src/corelib/kernel/qmetaobject.cpp
@@ -590,6 +590,24 @@ bool QMetaObjectPrivate::methodMatch(const QMetaObject *m, const QMetaMethod &me
     return true;
 }
 
+/*!
+   \internal
+   Returns the first method with name \a name found in \a baseObject
+ */
+QMetaMethod QMetaObjectPrivate::firstMethod(const QMetaObject *baseObject, QByteArrayView name)
+{
+    for (const QMetaObject *currentObject = baseObject; currentObject; currentObject = currentObject->superClass()) {
+        const int start = priv(currentObject->d.data)->methodCount - 1;
+        const int end = 0;
+        for (int i = start; i >= end; --i) {
+            auto candidate = QMetaMethod::fromRelativeMethodIndex(currentObject, i);
+            if (name == candidate.name())
+                return candidate;
+        }
+    }
+    return QMetaMethod{};
+}
+
 /**
 * \internal
 * helper function for indexOf{Method,Slot,Signal}, returns the relative index of the method within
diff --git a/src/corelib/kernel/qmetaobject_p.h b/src/corelib/kernel/qmetaobject_p.h
index efc1eafc8f..dbd82ba27b 100644
--- a/src/corelib/kernel/qmetaobject_p.h
+++ b/src/corelib/kernel/qmetaobject_p.h
@@ -253,6 +253,7 @@ struct QMetaObjectPrivate
     static bool methodMatch(const QMetaObject *m, const QMetaMethod &method,
                             const QByteArray &name, int argc,
                             const QArgumentType *types);
+    Q_CORE_EXPORT static QMetaMethod firstMethod(const QMetaObject *baseObject, QByteArrayView name);
 
 };