Import Qt5x2 branch of QtWebkit for Qt 5.2

Importing a new snapshot of webkit.

Change-Id: I2d01ad12cdc8af8cb015387641120a9d7ea5f10c
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@digia.com>

1 files changed, 71 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/runtime/VMStackBounds.h b/Source/JavaScriptCore/runtime/VMStackBounds.h
new file mode 100644
index 000000000..76a3ebd30
--- /dev/null
+++ b/Source/JavaScriptCore/runtime/VMStackBounds.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2013 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#ifndef VMStackBounds_h
+#define VMStackBounds_h
+
+#include "VM.h"
+#include <wtf/StackBounds.h>
+
+namespace JSC {
+
+class VMStackBounds {
+public:
+    VMStackBounds(VM& vm, const StackBounds& bounds)
+        : m_vm(vm)
+        , m_bounds(bounds)
+    {
+    }
+
+    bool isSafeToRecurse() const { return m_bounds.isSafeToRecurse(requiredCapacity()); }
+
+private:
+    inline size_t requiredCapacity() const
+    {
+        Interpreter* interpreter = m_vm.interpreter;
+
+        // We have two separate stack limits, one for regular JS execution, and one
+        // for when we're handling errors. We need the error stack to be smaller
+        // otherwise there would obviously not be any stack left to execute JS in when
+        // there's a stack overflow.
+        //
+        // These sizes were derived from the stack usage of a number of sites when
+        // layout occurs when we've already consumed most of the C stack.
+        const size_t requiredStack = 128 * KB;
+        const size_t errorModeRequiredStack = 64 * KB;
+
+        size_t requiredCapacity = interpreter->isInErrorHandlingMode() ? errorModeRequiredStack : requiredStack;
+        RELEASE_ASSERT(m_bounds.size() >= requiredCapacity);
+        return requiredCapacity; 
+    }
+
+    VM& m_vm;
+    const StackBounds& m_bounds;
+};
+
+} // namespace JSC
+
+#endif // VMStackBounds_h
+