Avoid unnecessary re-generation qml cache files in some circumstances

The map of name IDs to resolved types so far is copied several times
during compilation and different compile passes see different copies of it.
Compile passes may add things to the map, and if they do that on copies
that are inaccessible to other code, we get nondeterministic results.
Furthermore all the copies and pointers are confusing and inefficient.

Fixes: QTBUG-69340
Change-Id: I43ad3cbeeec34f90e05570eddc901fe8aa64c709
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

4 files changed, 13 insertions, 9 deletions

diff --git a/src/qml/qml/qqmlobjectcreator.cpp b/src/qml/qml/qqmlobjectcreator.cpp
index 68e2c2c928..5af658194f 100644
--- a/src/qml/qml/qqmlobjectcreator.cpp
+++ b/src/qml/qml/qqmlobjectcreator.cpp
@@ -75,7 +75,6 @@ QQmlObjectCreator::QQmlObjectCreator(QQmlContextData *parentContext, const QQmlR
                                      QQmlIncubatorPrivate *incubator)
     : phase(Startup)
     , compilationUnit(compilationUnit)
-    , resolvedTypes(compilationUnit->resolvedTypes)
     , propertyCaches(&compilationUnit->propertyCaches)
     , sharedState(new QQmlObjectCreatorSharedState)
     , topLevelCreator(true)
@@ -102,7 +101,6 @@ QQmlObjectCreator::QQmlObjectCreator(QQmlContextData *parentContext, const QQmlR
 QQmlObjectCreator::QQmlObjectCreator(QQmlContextData *parentContext, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, QQmlObjectCreatorSharedState *inheritedSharedState)
     : phase(Startup)
     , compilationUnit(compilationUnit)
-    , resolvedTypes(compilationUnit->resolvedTypes)
     , propertyCaches(&compilationUnit->propertyCaches)
     , sharedState(inheritedSharedState)
     , topLevelCreator(false)
@@ -785,7 +783,7 @@ bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *bindingProper
 {
     if (binding->type == QV4::CompiledData::Binding::Type_AttachedProperty) {
         Q_ASSERT(stringAt(compilationUnit->objectAt(binding->value.objectIndex)->inheritedTypeNameIndex).isEmpty());
-        QV4::CompiledData::ResolvedTypeReference *tr = resolvedTypes.value(binding->propertyNameIndex);
+        QV4::CompiledData::ResolvedTypeReference *tr = resolvedType(binding->propertyNameIndex);
         Q_ASSERT(tr);
         QQmlType attachedType = tr->type;
         if (!attachedType.isValid()) {
@@ -1151,7 +1149,8 @@ QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isCo
         instance = component;
         ddata = QQmlData::get(instance, /*create*/true);
     } else {
-        QV4::CompiledData::ResolvedTypeReference *typeRef = resolvedTypes.value(obj->inheritedTypeNameIndex);
+        QV4::CompiledData::ResolvedTypeReference *typeRef
+                = resolvedType(obj->inheritedTypeNameIndex);
         Q_ASSERT(typeRef);
         installPropertyCache = !typeRef->isFullyDynamicType;
         QQmlType type = typeRef->type;
diff --git a/src/qml/qml/qqmlobjectcreator_p.h b/src/qml/qml/qqmlobjectcreator_p.h
index 020e673941..5aca60e2f0 100644
--- a/src/qml/qml/qqmlobjectcreator_p.h
+++ b/src/qml/qml/qqmlobjectcreator_p.h
@@ -125,6 +125,10 @@ private:
 
     inline QV4::QmlContext *currentQmlContext();
     Q_NEVER_INLINE void createQmlContext();
+    QV4::CompiledData::ResolvedTypeReference *resolvedType(int id) const
+    {
+        return compilationUnit->resolvedType(id);
+    }
 
     enum Phase {
         Startup,
@@ -141,7 +145,6 @@ private:
     const QV4::CompiledData::Unit *qmlUnit;
     QQmlGuardedContextData parentContext;
     QQmlContextData *context;
-    const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypes;
     const QQmlPropertyCacheVector *propertyCaches;
     QExplicitlySharedDataPointer<QQmlObjectCreatorSharedState> sharedState;
     bool topLevelCreator;
diff --git a/src/qml/qml/qqmltypeloader.cpp b/src/qml/qml/qqmltypeloader.cpp
index 9df502f778..df6a8f1500 100644
--- a/src/qml/qml/qqmltypeloader.cpp
+++ b/src/qml/qml/qqmltypeloader.cpp
@@ -2348,7 +2348,7 @@ void QQmlTypeData::done()
 
     QQmlEngine *const engine = typeLoader()->engine();
 
-    const auto dependencyHasher = [engine, resolvedTypeCache, this](QCryptographicHash *hash) {
+    const auto dependencyHasher = [engine, &resolvedTypeCache, this](QCryptographicHash *hash) {
         if (!resolvedTypeCache.addToHash(hash, engine))
             return false;
         return ::addTypeReferenceChecksumsToHash(m_compositeSingletons, hash, engine);
@@ -2365,7 +2365,7 @@ void QQmlTypeData::done()
 
     if (!m_document.isNull()) {
         // Compile component
-        compile(typeNameCache, resolvedTypeCache, dependencyHasher);
+        compile(typeNameCache, &resolvedTypeCache, dependencyHasher);
     } else {
         createTypeAndPropertyCaches(typeNameCache, resolvedTypeCache);
     }
@@ -2638,7 +2638,8 @@ QString QQmlTypeData::stringAt(int index) const
     return m_document->jsGenerator.stringTable.stringForIndex(index);
 }
 
-void QQmlTypeData::compile(const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache, const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache,
+void QQmlTypeData::compile(const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache,
+                           QV4::CompiledData::ResolvedTypeReferenceMap *resolvedTypeCache,
                            const QV4::CompiledData::DependentTypesHasher &dependencyHasher)
 {
     Q_ASSERT(m_compiledData.isNull());
diff --git a/src/qml/qml/qqmltypeloader_p.h b/src/qml/qml/qqmltypeloader_p.h
index 5bb4e9d490..987e47222d 100644
--- a/src/qml/qml/qqmltypeloader_p.h
+++ b/src/qml/qml/qqmltypeloader_p.h
@@ -485,7 +485,8 @@ private:
             QV4::CompiledData::ResolvedTypeReferenceMap *resolvedTypeCache
             ) const;
     void compile(const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache,
-                 const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache, const QV4::CompiledData::DependentTypesHasher &dependencyHasher);
+                 QV4::CompiledData::ResolvedTypeReferenceMap *resolvedTypeCache,
+                 const QV4::CompiledData::DependentTypesHasher &dependencyHasher);
     void createTypeAndPropertyCaches(const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache,
                                       const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache);
     bool resolveType(const QString &typeName, int &majorVersion, int &minorVersion,