Imported WebKit commit 0dc6cd75e1d4836eaffbb520be96fac4847cc9d2 (http://svn.webkit.org/repository/webkit/trunk@131300)

WebKit update which introduces the QtWebKitWidgets module that contains the WK1
widgets based API. (In fact it renames QtWebKit to QtWebKitWidgets while we're
working on completing the entire split as part of
https://bugs.webkit.org/show_bug.cgi?id=99314

1 files changed, 124 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/interpreter/JSStack.h b/Source/JavaScriptCore/interpreter/JSStack.h
new file mode 100644
index 000000000..86fa40be7
--- /dev/null
+++ b/Source/JavaScriptCore/interpreter/JSStack.h
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2008, 2009 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.
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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 JSStack_h
+#define JSStack_h
+
+#include "ExecutableAllocator.h"
+#include "Register.h"
+#include <wtf/Noncopyable.h>
+#include <wtf/PageReservation.h>
+#include <wtf/VMTags.h>
+
+namespace JSC {
+
+    class ConservativeRoots;
+    class DFGCodeBlocks;
+    class JITStubRoutineSet;
+    class LLIntOffsetsExtractor;
+
+    class JSStack {
+        WTF_MAKE_NONCOPYABLE(JSStack);
+    public:
+        enum CallFrameHeaderEntry {
+            CallFrameHeaderSize = 6,
+
+            ArgumentCount = -6,
+            CallerFrame = -5,
+            Callee = -4,
+            ScopeChain = -3,
+            ReturnPC = -2, // This is either an Instruction* or a pointer into JIT generated code stored as an Instruction*.
+            CodeBlock = -1,
+        };
+
+        static const size_t defaultCapacity = 512 * 1024;
+        static const size_t commitSize = 16 * 1024;
+        // Allow 8k of excess registers before we start trying to reap the stack
+        static const ptrdiff_t maxExcessCapacity = 8 * 1024;
+
+        JSStack(size_t capacity = defaultCapacity);
+        ~JSStack();
+        
+        void gatherConservativeRoots(ConservativeRoots&);
+        void gatherConservativeRoots(ConservativeRoots&, JITStubRoutineSet&, DFGCodeBlocks&);
+
+        Register* begin() const { return static_cast<Register*>(m_reservation.base()); }
+        Register* end() const { return m_end; }
+        size_t size() const { return end() - begin(); }
+
+        bool grow(Register*);
+        void shrink(Register*);
+        
+        static size_t committedByteCount();
+        static void initializeThreading();
+
+        Register* const * addressOfEnd() const
+        {
+            return &m_end;
+        }
+
+    private:
+        friend class LLIntOffsetsExtractor;
+
+        bool growSlowCase(Register*);
+        void releaseExcessCapacity();
+        void addToCommittedByteCount(long);
+        Register* m_end;
+        Register* m_commitEnd;
+        PageReservation m_reservation;
+    };
+
+    inline JSStack::JSStack(size_t capacity)
+        : m_end(0)
+    {
+        ASSERT(capacity && isPageAligned(capacity));
+
+        m_reservation = PageReservation::reserve(roundUpAllocationSize(capacity * sizeof(Register), commitSize), OSAllocator::JSVMStackPages);
+        m_end = static_cast<Register*>(m_reservation.base());
+        m_commitEnd = static_cast<Register*>(m_reservation.base());
+    }
+
+    inline void JSStack::shrink(Register* newEnd)
+    {
+        if (newEnd >= m_end)
+            return;
+        m_end = newEnd;
+        if (m_end == m_reservation.base() && (m_commitEnd - begin()) >= maxExcessCapacity)
+            releaseExcessCapacity();
+    }
+
+    inline bool JSStack::grow(Register* newEnd)
+    {
+        if (newEnd <= m_end)
+            return true;
+        return growSlowCase(newEnd);
+    }
+
+} // namespace JSC
+
+#endif // JSStack_h