Add abstraction for temporarily setting StaticData when saving

The StaticData flag needs to be saved to disk, but removed again
afterwards so that we can free() the malloc'd data. This also allows us
to avoid copying all the data into a byte array before saving.

Change-Id: I96513f8d98acf0ea0b4514d96376b487e8444917
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 43 insertions, 0 deletions

diff --git a/src/qml/compiler/qv4compileddata_p.h b/src/qml/compiler/qv4compileddata_p.h
index 9301939bff..629adf8231 100644
--- a/src/qml/compiler/qv4compileddata_p.h
+++ b/src/qml/compiler/qv4compileddata_p.h
@@ -1158,6 +1158,49 @@ public:
     bool saveToDisk(const QString &outputFileName, QString *errorString) const;
 };
 
+class SaveableUnitPointer
+{
+    Q_DISABLE_COPY_MOVE(SaveableUnitPointer)
+public:
+    SaveableUnitPointer(const CompilationUnit *unit, quint32 temporaryFlags = Unit::StaticData) :
+          unit(unit)
+    {
+        quint32_le &unitFlags = mutableFlags();
+        quint32 origFlags = unitFlags;
+        unitFlags |= temporaryFlags;
+        changedFlags = origFlags ^ unitFlags;
+    }
+
+    ~SaveableUnitPointer()
+    {
+        mutableFlags() ^= changedFlags;
+    }
+
+    const CompilationUnit *operator->() const { return unit; }
+    const CompilationUnit &operator*() const { return *unit; }
+    operator const CompilationUnit *() { return unit; }
+
+    template<typename Char>
+    const Char *data() const
+    {
+        Q_STATIC_ASSERT(sizeof(Char) == 1);
+        const Char *dataPtr;
+        memcpy(&dataPtr, &unit->data, sizeof(dataPtr));
+        return dataPtr;
+    }
+
+    quint32 size() const
+    {
+        return unit->data->unitSize;
+    }
+
+private:
+    quint32_le &mutableFlags() { return const_cast<Unit *>(unit->unitData())->flags; };
+    const CompilationUnit *unit;
+    quint32 changedFlags;
+};
+
+
 } // CompiledData namespace
 } // QV4 namespace