1 files changed, 26 insertions, 10 deletions

diff --git a/tools/qscxmlc/generator.cpp b/tools/qscxmlc/generator.cpp
index 571c255..4586c1d 100644
--- a/tools/qscxmlc/generator.cpp
+++ b/tools/qscxmlc/generator.cpp
@@ -96,7 +96,7 @@ Generator::Generator(ClassDef *classDef, const QList<QByteArray> &metaTypes,
       requireCompleteTypes(requireCompleteTypes)
 {
     if (cdef->superclassList.size())
-        purestSuperClass = cdef->superclassList.constFirst().first;
+        purestSuperClass = cdef->superclassList.constFirst().classname;
 }
 // -- QtScxml
 
@@ -635,10 +635,9 @@ void Generator::generateCode()
         auto it = cdef->superclassList.cbegin() + 1;
         const auto end = cdef->superclassList.cend();
         for (; it != end; ++it) {
-            const auto &[className, access] = *it;
-            if (access == FunctionDef::Private)
+            if (it->access == FunctionDef::Private)
                 continue;
-            const char *cname = className.constData();
+            const char *cname = it->classname.constData();
             fprintf(out, "    if (!strcmp(_clname, \"%s\"))\n        return static_cast< %s*>(this);\n",
                     cname, cname);
         }
@@ -682,12 +681,29 @@ void Generator::generateCode()
 // Generate function to make sure the non-class signals exist in the parent classes
 //
     if (!cdef->nonClassSignalList.isEmpty()) {
-        fprintf(out, "// If you get a compile error in this function it can be because either\n");
-        fprintf(out, "//     a) You are using a NOTIFY signal that does not exist. Fix it.\n");
-        fprintf(out, "//     b) You are using a NOTIFY signal that does exist (in a parent class) but has a non-empty parameter list. This is a moc limitation.\n");
-        fprintf(out, "[[maybe_unused]] static void checkNotifySignalValidity_%s(%s *t) {\n", qualifiedClassNameIdentifier.constData(), cdef->qualified.constData());
-        for (const QByteArray &nonClassSignal : std::as_const(cdef->nonClassSignalList))
-            fprintf(out, "    t->%s();\n", nonClassSignal.constData());
+        fprintf(out, "namespace CheckNotifySignalValidity_%s {\n", qualifiedClassNameIdentifier.constData());
+        for (const QByteArray &nonClassSignal : std::as_const(cdef->nonClassSignalList)) {
+            const auto propertyIt = std::find_if(cdef->propertyList.constBegin(),
+                                   cdef->propertyList.constEnd(),
+                                   [&nonClassSignal](const PropertyDef &p) {
+                return nonClassSignal == p.notify;
+            });
+            // must find something, otherwise checkProperties wouldn't have inserted an entry into nonClassSignalList
+            Q_ASSERT(propertyIt != cdef->propertyList.constEnd());
+            fprintf(out, "template<typename T> using has_nullary_%s = decltype(std::declval<T>().%s());\n",
+                    nonClassSignal.constData(),
+                    nonClassSignal.constData());
+            const auto &propertyType = propertyIt->type;
+            fprintf(out, "template<typename T> using has_unary_%s = decltype(std::declval<T>().%s(std::declval<%s>()));\n",
+                    nonClassSignal.constData(),
+                    nonClassSignal.constData(),
+                    propertyType.constData());
+            fprintf(out, "static_assert(qxp::is_detected_v<has_nullary_%s, %s> || qxp::is_detected_v<has_unary_%s, %s>,\n"
+                         "              \"NOTIFY signal %s does not exist in class (or is private in its parent)\");\n",
+                    nonClassSignal.constData(), cdef->qualified.constData(),
+                    nonClassSignal.constData(), cdef->qualified.constData(),
+                    nonClassSignal.constData());
+        }
         fprintf(out, "}\n");
     }
 }