V4 debugger: Allow retrieval of non-CallContext scopes

We need to encode the scope type properly and we need to return
something from the "scope" command. Previously the client didn't even
get notified about QML contexts and couldn't actually retrieve anything
but call context. The other scope types are not terribly interesting
right now, but at least for the global context it should be possible to
provide more data in the future.

Task-number: QTBUG-68218
Change-Id: I88d3dbc15a93f19b00f6f12365e4fb64ec78862e
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

2 files changed, 23 insertions, 25 deletions

diff --git a/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.cpp b/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.cpp
index c86f3d1803..95e6d5704c 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.cpp
+++ b/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.cpp
@@ -72,16 +72,12 @@ QV4::Heap::ExecutionContext *QV4DataCollector::findContext(int frame)
     return f ? f->context()->d() : nullptr;
 }
 
-QV4::Heap::CallContext *QV4DataCollector::findScope(QV4::Heap::ExecutionContext *ctx, int scope)
+QV4::Heap::ExecutionContext *QV4DataCollector::findScope(QV4::Heap::ExecutionContext *ctx, int scope)
 {
-    if (!ctx)
-        return nullptr;
-
     for (; scope > 0 && ctx; --scope)
         ctx = ctx->outer;
 
-    return (ctx && ctx->type == QV4::Heap::ExecutionContext::Type_CallContext) ?
-                static_cast<QV4::Heap::CallContext *>(ctx) : nullptr;
+    return ctx;
 }
 
 QVector<QV4::Heap::ExecutionContext::ContextType> QV4DataCollector::getScopeTypes(int frame)
@@ -108,6 +104,7 @@ int QV4DataCollector::encodeScopeType(QV4::Heap::ExecutionContext::ContextType s
     case QV4::Heap::ExecutionContext::Type_CallContext:
         return 1;
     case QV4::Heap::ExecutionContext::Type_QmlContext:
+        return 3;
     default:
         return -1;
     }
@@ -259,31 +256,32 @@ bool QV4DataCollector::isValidRef(QV4DataCollector::Ref ref) const
 
 bool QV4DataCollector::collectScope(QJsonObject *dict, int frameNr, int scopeNr)
 {
-    QStringList names;
-
     QV4::Scope scope(engine());
 
-    QV4::Scoped<QV4::CallContext> ctxt(scope, findScope(findContext(frameNr), scopeNr));
+    QV4::Scoped<QV4::ExecutionContext> ctxt(scope, findScope(findContext(frameNr), scopeNr));
     if (!ctxt)
         return false;
 
-    Refs collectedRefs;
-    QV4::ScopedValue v(scope);
-    QV4::InternalClass *ic = ctxt->internalClass();
-    for (uint i = 0; i < ic->size; ++i) {
-        QString name = ic->nameMap[i]->string;
-        names.append(name);
-        v = ctxt->d()->locals[i];
-        collectedRefs.append(collect(v));
-    }
-
     QV4::ScopedObject scopeObject(scope, engine()->newObject());
+    if (ctxt->d()->type == QV4::Heap::ExecutionContext::Type_CallContext) {
+        QStringList names;
+        Refs collectedRefs;
+
+        QV4::ScopedValue v(scope);
+        QV4::InternalClass *ic = ctxt->internalClass();
+        for (uint i = 0; i < ic->size; ++i) {
+            QString name = ic->nameMap[i]->string;
+            names.append(name);
+            v = static_cast<QV4::Heap::CallContext *>(ctxt->d())->locals[i];
+            collectedRefs.append(collect(v));
+        }
 
-    Q_ASSERT(names.size() == collectedRefs.size());
-    QV4::ScopedString propName(scope);
-    for (int i = 0, ei = collectedRefs.size(); i != ei; ++i) {
-        propName = engine()->newString(names.at(i));
-        scopeObject->put(propName, QV4::Value::fromReturnedValue(getValue(collectedRefs.at(i))));
+        Q_ASSERT(names.size() == collectedRefs.size());
+        QV4::ScopedString propName(scope);
+        for (int i = 0, ei = collectedRefs.size(); i != ei; ++i) {
+            propName = engine()->newString(names.at(i));
+            scopeObject->put(propName, (v = getValue(collectedRefs.at(i))));
+        }
     }
 
     Ref scopeObjectRef = addRef(scopeObject);
diff --git a/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.h b/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.h
index 87be009de5..5494e10e9a 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.h
+++ b/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.h
@@ -58,7 +58,7 @@ public:
     typedef uint Ref;
     typedef QVector<uint> Refs;
 
-    static QV4::Heap::CallContext *findScope(QV4::Heap::ExecutionContext *ctxt, int scope);
+    static QV4::Heap::ExecutionContext *findScope(QV4::Heap::ExecutionContext *ctxt, int scope);
     static int encodeScopeType(QV4::Heap::ExecutionContext::ContextType scopeType);
 
     QVector<QV4::Heap::ExecutionContext::ContextType> getScopeTypes(int frame);