Add a StringOrSymbol intermediate class between Managed and String

This introduces a common base class for Strings and Symbols
giving us a unified approach to handling object properties for
both.

Change-Id: Ic9e5a18b084c8b730e134db990f101d47af224e3
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

6 files changed, 30 insertions, 6 deletions

diff --git a/src/qml/jsruntime/qv4arraydata.cpp b/src/qml/jsruntime/qv4arraydata.cpp
index b33b34ee08..1285dcdae1 100644
--- a/src/qml/jsruntime/qv4arraydata.cpp
+++ b/src/qml/jsruntime/qv4arraydata.cpp
@@ -59,6 +59,7 @@ const QV4::VTable QV4::ArrayData::static_vtbl = {
     QV4::ArrayData::IsFunctionObject,
     QV4::ArrayData::IsErrorObject,
     QV4::ArrayData::IsArrayData,
+    QV4::ArrayData::IsStringOrSymbol,
     0,
     QV4::ArrayData::MyType,
     "ArrayData",
diff --git a/src/qml/jsruntime/qv4managed.cpp b/src/qml/jsruntime/qv4managed.cpp
index 1eea17b8e3..924d2263c9 100644
--- a/src/qml/jsruntime/qv4managed.cpp
+++ b/src/qml/jsruntime/qv4managed.cpp
@@ -55,6 +55,7 @@ const VTable Managed::static_vtbl =
     Managed::IsFunctionObject,
     Managed::IsErrorObject,
     Managed::IsArrayData,
+    Managed::IsStringOrSymbol,
     0,
     Managed::MyType,
     "Managed",
diff --git a/src/qml/jsruntime/qv4managed_p.h b/src/qml/jsruntime/qv4managed_p.h
index 7c5bda3efb..c8581d7306 100644
--- a/src/qml/jsruntime/qv4managed_p.h
+++ b/src/qml/jsruntime/qv4managed_p.h
@@ -140,6 +140,7 @@ inline void qYouForgotTheQ_MANAGED_Macro(T1, T2) {}
     classname::IsFunctionObject,   \
     classname::IsErrorObject,   \
     classname::IsArrayData,   \
+    classname::IsStringOrSymbol,   \
     0,                                          \
     classname::MyType,                          \
     #classname, \
@@ -163,6 +164,7 @@ struct Q_QML_PRIVATE_EXPORT Managed : Value
     enum {
         IsExecutionContext = false,
         IsString = false,
+        IsStringOrSymbol = false,
         IsObject = false,
         IsFunctionObject = false,
         IsErrorObject = false,
diff --git a/src/qml/jsruntime/qv4string.cpp b/src/qml/jsruntime/qv4string.cpp
index a7a8868bdd..d14dfd082f 100644
--- a/src/qml/jsruntime/qv4string.cpp
+++ b/src/qml/jsruntime/qv4string.cpp
@@ -69,6 +69,7 @@ void Heap::String::markObjects(Heap::Base *that, MarkStack *markStack)
     }
 }
 
+DEFINE_MANAGED_VTABLE(StringOrSymbol);
 DEFINE_MANAGED_VTABLE(String);
 
 
diff --git a/src/qml/jsruntime/qv4string_p.h b/src/qml/jsruntime/qv4string_p.h
index 200d979f24..0a316d85b5 100644
--- a/src/qml/jsruntime/qv4string_p.h
+++ b/src/qml/jsruntime/qv4string_p.h
@@ -64,7 +64,13 @@ struct Identifier;
 
 namespace Heap {
 
-struct Q_QML_PRIVATE_EXPORT String : Base {
+struct Q_QML_PRIVATE_EXPORT StringOrSymbol : Base
+{
+    mutable QStringData *text;
+    mutable Identifier identifier;
+};
+
+struct Q_QML_PRIVATE_EXPORT String : StringOrSymbol {
     static void markObjects(Heap::Base *that, MarkStack *markStack);
     enum StringType {
         StringType_Regular,
@@ -118,8 +124,6 @@ struct Q_QML_PRIVATE_EXPORT String : Base {
 
     bool startsWithUpper() const;
 
-    mutable QStringData *text;
-    mutable Identifier identifier;
     mutable uint subtype;
     mutable uint stringHash;
 private:
@@ -150,9 +154,18 @@ int String::length() const {
 
 }
 
-struct Q_QML_PRIVATE_EXPORT String : public Managed {
+struct Q_QML_PRIVATE_EXPORT StringOrSymbol : public Managed {
+#ifndef V4_BOOTSTRAP
+    V4_MANAGED(StringOrSymbol, Managed)
+    enum {
+        IsStringOrSymbol = true
+    };
+#endif
+};
+
+struct Q_QML_PRIVATE_EXPORT String : public StringOrSymbol {
 #ifndef V4_BOOTSTRAP
-    V4_MANAGED(String, Managed)
+    V4_MANAGED(String, StringOrSymbol)
     Q_MANAGED_TYPE(String)
     V4_INTERNALCLASS(String)
     V4_NEEDS_DESTROY
@@ -285,6 +298,11 @@ struct ComplexString : String {
 };
 
 template<>
+inline const StringOrSymbol *Value::as() const {
+    return isManaged() && m()->internalClass->vtable->isStringOrSymbol ? static_cast<const String *>(this) : nullptr;
+}
+
+template<>
 inline const String *Value::as() const {
     return isManaged() && m()->internalClass->vtable->isString ? static_cast<const String *>(this) : nullptr;
 }
diff --git a/src/qml/memory/qv4heap_p.h b/src/qml/memory/qv4heap_p.h
index f327388355..316b89b829 100644
--- a/src/qml/memory/qv4heap_p.h
+++ b/src/qml/memory/qv4heap_p.h
@@ -75,7 +75,8 @@ struct VTable
     uint isFunctionObject : 1;
     uint isErrorObject : 1;
     uint isArrayData : 1;
-    uint unused : 18;
+    uint isStringOrSymbol : 1;
+    uint unused : 17;
     uint type : 8;
     const char *className;
     void (*destroy)(Heap::Base *);