QmlDesigner: Skip makeComponentChain in TextToModelMerger::load

This is not required in the context of QmlDesigner and can become
very slow.

Change-Id: Id4a4ae30c5fa55e88ed295624365efb724e26f62
Reviewed-by: Vikas Pachdha <vikas.pachdha@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/libs/qmljs/qmljsscopechain.cpp

@@ -11,6 +11,8 @@
 
 using namespace QmlJS;
 
+bool ScopeChain::s_setSkipmakeComponentChain = false;
+
 /*!
     \class QmlJS::ScopeChain
     \brief The ScopeChain class describes the scopes used for global lookup in
@@ -210,6 +212,11 @@ QList<const ObjectValue *> ScopeChain::all() const
     return m_all;
 }
 
+void ScopeChain::setSkipmakeComponentChain(bool b)
+{
+    s_setSkipmakeComponentChain = b;
+}
+
 static void collectScopes(const QmlComponentChain *chain, QList<const ObjectValue *> *target)
 {
     foreach (const QmlComponentChain *parent, chain->instantiatingComponents())
@@ -351,6 +358,9 @@ void ScopeChain::makeComponentChain(
         const Snapshot &snapshot,
         QHash<const Document *, QmlComponentChain *> *components)
 {
+    if (s_setSkipmakeComponentChain)
+        return;
+
     Document::Ptr doc = target->document();
     if (!doc->qmlProgram())
         return;

src/libs/qmljs/qmljsscopechain.h

@@ -77,6 +77,8 @@ public:
 
     QList<const ObjectValue *> all() const;
 
+    static void setSkipmakeComponentChain(bool b);
+
 private:
     void update() const;
     void initializeRootScope();
@@ -97,6 +99,8 @@ private:
 
     mutable bool m_modified;
     mutable QList<const ObjectValue *> m_all;
+
+    static bool s_setSkipmakeComponentChain;
 };
 
 } // namespace QmlJS

src/plugins/qmldesigner/designercore/model/texttomodelmerger.cpp

@@ -1092,6 +1092,9 @@ Document::MutablePtr TextToModelMerger::createParsedDocument(const QUrl &url, co
 
 bool TextToModelMerger::load(const QString &data, DifferenceHandler &differenceHandler)
 {
+    QmlJS::ScopeChain::setSkipmakeComponentChain(true);
+    QScopeGuard unSkip([]() { QmlJS::ScopeChain::setSkipmakeComponentChain(false); });
+
     qCInfo(rewriterBenchmark) << Q_FUNC_INFO;
 
     const bool justSanityCheck = !differenceHandler.isAmender();