qmllint: search methods and properties also in attached type

I changed the strategy of traverse via related types.
Before:
  traversal happens only via linked list type -> type->superClass
After:
  traversal via binary tree formed by attachedType and superClass
  I use pre-order strategy, current type, then all attached types,
  then all super classes

Fixes: QTBUG-84861
Change-Id: I4a8fce869bc541de6900514d29575174d2753f02
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

4 files changed, 76 insertions, 22 deletions

diff --git a/tests/auto/qml/qmllint/data/AttachedType.qml b/tests/auto/qml/qmllint/data/AttachedType.qml
new file mode 100644
index 0000000000..02fa514e83
--- /dev/null
+++ b/tests/auto/qml/qmllint/data/AttachedType.qml
@@ -0,0 +1,5 @@
+import Things 1.0
+
+Item {
+    property real test: Screen.pixelDensity * 0.5
+}
diff --git a/tests/auto/qml/qmllint/data/Things/plugins.qmltypes b/tests/auto/qml/qmllint/data/Things/plugins.qmltypes
index 95ff95eb7d..448a966145 100644
--- a/tests/auto/qml/qmllint/data/Things/plugins.qmltypes
+++ b/tests/auto/qml/qmllint/data/Things/plugins.qmltypes
@@ -30,4 +30,29 @@ Module {
         Property { name: "contentData"; type: "QObject"; isList: true; isReadonly: true }
         Property { name: "contentChildren"; type: "QQuickItem"; isList: true; isReadonly: true }
     }
+    Component {
+        name: "MyScreen"
+        prototype: "QObject"
+        exports: [
+            "Things.Window/Screen 1.0",
+        ]
+        isCreatable: false
+        attachedType: "MyScreenAttached"
+    }
+    Component {
+        name: "MyScreenAttached"
+        prototype: "MyScreenInfo"
+        exports: [
+            "Things.Window/ScreenAttached 1.0",
+        ]
+    }
+    Component {
+        name: "MyScreenInfo"
+        prototype: "QObject"
+        exports: [
+            "Things.Window/ScreenInfo 1.0",
+        ]
+        isCreatable: false
+        Property { name: "pixelDensity"; type: "double"; isReadonly: true }
+    }
 }
diff --git a/tests/auto/qml/qmllint/tst_qmllint.cpp b/tests/auto/qml/qmllint/tst_qmllint.cpp
index 7459a813be..d5912def6b 100644
--- a/tests/auto/qml/qmllint/tst_qmllint.cpp
+++ b/tests/auto/qml/qmllint/tst_qmllint.cpp
@@ -223,6 +223,7 @@ void TestQmllint::cleanQmlCode_data()
     QTest::newRow("EnumAccess1") << QStringLiteral("EnumAccess1.qml");
     QTest::newRow("EnumAccess2") << QStringLiteral("EnumAccess2.qml");
     QTest::newRow("ListProperty") << QStringLiteral("ListProperty.qml");
+    QTest::newRow("AttachedType") << QStringLiteral("AttachedType.qml");
 }
 
 void TestQmllint::cleanQmlCode()
diff --git a/tools/qmllint/checkidentifiers.cpp b/tools/qmllint/checkidentifiers.cpp
index 32eb4ce025..2771e1cfb2 100644
--- a/tools/qmllint/checkidentifiers.cpp
+++ b/tools/qmllint/checkidentifiers.cpp
@@ -31,6 +31,7 @@
 
 #include <QtCore/qqueue.h>
 #include <QtCore/qsharedpointer.h>
+#include <stack>
 
 class IssueLocationWithContext
 {
@@ -82,6 +83,30 @@ void CheckIdentifiers::printContext(const QQmlJS::SourceLocation &location) cons
                            + QLatin1Char('\n'), Normal);
 }
 
+static bool walkViaParentAndAttachedScopes(ScopeTree::ConstPtr rootType,
+                                           const QHash<QString, ScopeTree::ConstPtr> &allTypes,
+                                           std::function<bool(ScopeTree::ConstPtr)> visit)
+{
+    if (rootType == nullptr)
+        return false;
+    std::stack<ScopeTree::ConstPtr> stack;
+    stack.push(rootType);
+    while (!stack.empty()) {
+        const auto type = stack.top();
+        stack.pop();
+
+        if (visit(type))
+            return true;
+
+        if (auto superType = allTypes.value(type->superclassName()))
+            stack.push(superType);
+
+        if (auto attachedType = allTypes.value(type->attachedTypeName()))
+            stack.push(attachedType);
+    }
+    return false;
+}
+
 bool CheckIdentifiers::checkMemberAccess(const QVector<ScopeTree::FieldMember> &members,
                                          const ScopeTree::ConstPtr &outerScope,
                                          const MetaProperty *prop) const
@@ -199,29 +224,27 @@ bool CheckIdentifiers::checkMemberAccess(const QVector<ScopeTree::FieldMember> &
         if (!detectedRestrictiveName.isEmpty())
             continue;
 
-        auto type = m_types.value(access.m_parentType.isEmpty() ? scopeName : access.m_parentType);
-        bool typeFound = false;
-        while (type) {
-            const auto typeProperties = type->properties();
-            const auto typeIt = typeProperties.find(access.m_name);
-            if (typeIt != typeProperties.end()) {
-                const ScopeTree::ConstPtr propType = typeIt->type();
-                scope = propType ? propType : m_types.value(typeIt->typeName());
-                typeFound = true;
-                break;
-            }
-
-            const auto typeMethods = type->methods();
-            const auto typeMethodIt = typeMethods.find(access.m_name);
-            if (typeMethodIt != typeMethods.end()) {
-                detectedRestrictiveName = access.m_name;
-                detectedRestrictiveKind = QLatin1String("method");
-                typeFound = true;
-                break;
-            }
+        auto rootType =
+                m_types.value(access.m_parentType.isEmpty() ? scopeName : access.m_parentType);
+        bool typeFound =
+                walkViaParentAndAttachedScopes(rootType, m_types, [&](ScopeTree::ConstPtr type) {
+                    const auto typeProperties = type->properties();
+                    const auto typeIt = typeProperties.find(access.m_name);
+                    if (typeIt != typeProperties.end()) {
+                        const ScopeTree::ConstPtr propType = typeIt->type();
+                        scope = propType ? propType : m_types.value(typeIt->typeName());
+                        return true;
+                    }
 
-            type = m_types.value(type->superclassName());
-        }
+                    const auto typeMethods = type->methods();
+                    const auto typeMethodIt = typeMethods.find(access.m_name);
+                    if (typeMethodIt != typeMethods.end()) {
+                        detectedRestrictiveName = access.m_name;
+                        detectedRestrictiveKind = QLatin1String("method");
+                        return true;
+                    }
+                    return false;
+                });
         if (typeFound)
             continue;