Expose let/const variables from imported JS scripts

This patch allows QML to access let/const variables defined in JS files.

Detailed changes:

  - The recently added ContextType::ScriptImportedByQML is changed to avoid
    creating Push/PopScriptContext instructions, similar to
    ContextType::ESModule.

  - QV4::Module is changed to also work with CompilationUnits which are not
    ESModules. In this case QV4::Module will behave as if all lexically scoped
    variables were exported.

  - CompilationUnit is changed to support instantiating and evaluating
    QV4::Modules for non-ESModules as well.

  - QQmlTypeLoader is changed to always create QV4::Modules for evaluating
    scripts. For the non-ESModule case, the QV4::Module is evaluated inside a
    QV4::QmlContext, as before.

  - A pointer to the QV4::Module is added to QV4::QQmlContextWrapper, and used
    in virtualGet to access the let/const variables in the CallContext. Access
    is read-only.

Fixes: QTBUG-69408
Change-Id: I6f299363fdf5e1c5a4a0f1d9e655b4dc5112dd00
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 5 insertions, 1 deletions

diff --git a/src/qml/jsruntime/qv4module_p.h b/src/qml/jsruntime/qv4module_p.h
index 0cab161b82..dca0678fe9 100644
--- a/src/qml/jsruntime/qv4module_p.h
+++ b/src/qml/jsruntime/qv4module_p.h
@@ -62,7 +62,8 @@ namespace Heap {
 #define ModuleMembers(class, Member) \
     Member(class, NoMark, CompiledData::CompilationUnit *, unit) \
     Member(class, Pointer, CallContext *, scope) \
-    Member(class, HeapValue, HeapValue, self)
+    Member(class, HeapValue, HeapValue, self) \
+    Member(class, NoMark, bool, evaluated)
 
 DECLARE_EXPORTED_HEAP_OBJECT(Module, Object) {
     DECLARE_MARKOBJECTS(Module)
@@ -75,6 +76,9 @@ DECLARE_EXPORTED_HEAP_OBJECT(Module, Object) {
 struct Q_QML_EXPORT Module : public Object {
     V4_OBJECT2(Module, Object)
 
+    void evaluate();
+    const Value *resolveExport(PropertyKey key) const;
+
     static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
     static PropertyAttributes virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p);
     static bool virtualHasProperty(const Managed *m, PropertyKey id);