Enable resolution of composite types in QQmlTypeNameCache

We didn't have resolution of composite types previously, which is a
prerequisite to do more exciting things with QML types in JavaScript
(such as instanceof).

By deferring the resolution to QQmlImports, we can avoid the need to
fill the cache with types that may not be needed, while still finding
types which are requested.

In the future, we could consider removing the "special" handling for composite
singletons as they should be found through QQmlImports now. If we do
that, we may still want to cache the QUrl for the types, to avoid using
QQmlImports too often directly, as it is a little slow itself.

This change doesn't regress tst_compilation.

Task-number: QTBUG-24799
Change-Id: I9ba2e4829ca49008fd180fb488c586475cf90674
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 6 insertions, 4 deletions

diff --git a/src/qml/qml/qqmlimport.cpp b/src/qml/qml/qqmlimport.cpp
index e69789d5f4..257c280e50 100644
--- a/src/qml/qml/qqmlimport.cpp
+++ b/src/qml/qml/qqmlimport.cpp
@@ -400,9 +400,8 @@ QUrl QQmlImports::baseUrl() const
     document's imports into the \a cache for resolution elsewhere (e.g. in JS,
     or when loading additional types).
 
-    \note A current limitation of the implementation here is that only C++ types
-    are added to the type cache. This is due to file imports not having a
-    registered module.
+    \note This is for C++ types only. Composite types are handled separately,
+    as they do not have a QQmlTypeModule.
 */
 void QQmlImports::populateCache(QQmlTypeNameCache *cache) const
 {
@@ -420,11 +419,14 @@ void QQmlImports::populateCache(QQmlTypeNameCache *cache) const
 
         const QQmlImportNamespace &set = *ns;
 
+        // positioning is important; we must create the namespace even if there is no module.
+        QQmlTypeNameCache::Import &typeimport = cache->m_namedImports[set.prefix];
+        typeimport.m_qualifier = set.prefix;
+
         for (int ii = set.imports.count() - 1; ii >= 0; --ii) {
             const QQmlImportInstance *import = set.imports.at(ii);
             QQmlTypeModule *module = QQmlMetaType::typeModule(import->uri, import->majversion);
             if (module) {
-                QQmlTypeNameCache::Import &typeimport = cache->m_namedImports[set.prefix];
                 typeimport.modules.append(QQmlTypeModuleVersion(module, import->minversion));
             }
         }