WinRT: Do not call canAllocateExecutableMemory from static initializer

When the code generation capability is not set, the first call of
canAllocateExecutableMemory will cause a warning about suboptimal
performance. The qWarning code checks, which thread caused the message
and QThread::current sets QCoreApplicationPrivate;s theMainThread when
it is called for the first time on Windows.

If we call that function inside a static initializer, it will be called
before QCoreApplication is created and thus set the main thread to the
one that called the function. This will cause a warning about QApplication
not being created inside the main() thread, but more importantly,
delivering of events will not work in WinRT applications afterwards.

Task-number: QTBUG-66418
Change-Id: I3b6bf804983644b5ae5fe2288a587dc95fab2c8b
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 4 insertions, 4 deletions

diff --git a/src/qml/jsruntime/qv4engine_p.h b/src/qml/jsruntime/qv4engine_p.h
index 930ad8fed1..a37c640431 100644
--- a/src/qml/jsruntime/qv4engine_p.h
+++ b/src/qml/jsruntime/qv4engine_p.h
@@ -368,6 +368,9 @@ public:
     // but any time a QObject is wrapped a second time in another engine, we have to do
     // bookkeeping.
     MultiplyWrappedQObjectMap *m_multiplyWrappedQObjects;
+#if defined(V4_ENABLE_JIT) && !defined(V4_BOOTSTRAP)
+    const bool m_canAllocateExecutableMemory;
+#endif
 
     int internalClassIdCount = 0;
 
@@ -487,7 +490,7 @@ public:
     bool canJIT(Function *f = nullptr)
     {
 #if defined(V4_ENABLE_JIT) && !defined(V4_BOOTSTRAP)
-        if (!canAllocateExecutableMemory)
+        if (!m_canAllocateExecutableMemory)
             return false;
         if (f)
             return f->interpreterCallCount >= jitCallCountThreshold;
@@ -506,9 +509,6 @@ private:
     QScopedPointer<QV4::Profiling::Profiler> m_profiler;
 #endif
     int jitCallCountThreshold;
-#if defined(V4_ENABLE_JIT) && !defined(V4_BOOTSTRAP)
-    static const bool canAllocateExecutableMemory;
-#endif
 };
 
 // This is a trick to tell the code generators that functions taking a NoThrowContext won't