1 files changed, 127 insertions, 0 deletions
diff --git a/src/corelib/global/qmalloc.cpp b/src/corelib/global/qmalloc.cpp
new file mode 100644
index 0000000000..a12b0ba242
--- /dev/null
+++ b/src/corelib/global/qmalloc.cpp
@@ -0,0 +1,127 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qplatformdefs.h"
+
+#include <stdlib.h>
+
+/*
+    Define the container allocation functions in a separate file, so that our
+    users can easily override them.
+*/
+
+QT_BEGIN_NAMESPACE
+
+void *qMalloc(size_t size)
+{
+    return ::malloc(size);
+}
+
+void qFree(void *ptr)
+{
+    ::free(ptr);
+}
+
+void *qRealloc(void *ptr, size_t size)
+{
+    return ::realloc(ptr, size);
+}
+
+void *qMallocAligned(size_t size, size_t alignment)
+{
+    return qReallocAligned(0, size, 0, alignment);
+}
+
+void *qReallocAligned(void *oldptr, size_t newsize, size_t oldsize, size_t alignment)
+{
+    // fake an aligned allocation
+    Q_UNUSED(oldsize);
+
+    void *actualptr = oldptr ? static_cast<void **>(oldptr)[-1] : 0;
+    if (alignment <= sizeof(void*)) {
+        // special, fast case
+        void **newptr = static_cast<void **>(qRealloc(actualptr, newsize + sizeof(void*)));
+        if (!newptr)
+            return 0;
+        if (newptr == actualptr) {
+            // realloc succeeded without reallocating
+            return oldptr;
+        }
+
+        *newptr = newptr;
+        return newptr + 1;
+    }
+
+    // qMalloc returns pointers aligned at least at sizeof(size_t) boundaries
+    // but usually more (8- or 16-byte boundaries).
+    // So we overallocate by alignment-sizeof(size_t) bytes, so we're guaranteed to find a
+    // somewhere within the first alignment-sizeof(size_t) that is properly aligned.
+
+    // However, we need to store the actual pointer, so we need to allocate actually size +
+    // alignment anyway.
+
+    void *real = qRealloc(actualptr, newsize + alignment);
+    if (!real)
+        return 0;
+
+    quintptr faked = reinterpret_cast<quintptr>(real) + alignment;
+    faked &= ~(alignment - 1);
+
+    void **faked_ptr = reinterpret_cast<void **>(faked);
+
+    // now save the value of the real pointer at faked-sizeof(void*)
+    // by construction, alignment > sizeof(void*) and is a power of 2, so
+    // faked-sizeof(void*) is properly aligned for a pointer
+    faked_ptr[-1] = real;
+
+    return faked_ptr;
+}
+
+void qFreeAligned(void *ptr)
+{
+    if (!ptr)
+        return;
+    void **ptr2 = static_cast<void **>(ptr);
+    free(ptr2[-1]);
+}
+
+QT_END_NAMESPACE
+