/*

 *  Copyright (C) 2003, 2006 Apple Computer, Inc.

 *

 *  This library is free software; you can redistribute it and/or

 *  modify it under the terms of the GNU Lesser General Public

 *  License as published by the Free Software Foundation; either

 *  version 2 of the License, or (at your option) any later version.

 *

 *  This library is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 *  Lesser General Public License for more details.

 *

 *  You should have received a copy of the GNU Lesser General Public

 *  License along with this library; if not, write to the Free Software

 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,

 *  USA.

 *

 */

#include "config.h"

namespace KJS {

// This file exists because JavaScriptCore needs to define the NaN and Inf globals in a way

// that does not use a static initializer so we don't have a framework initialization routine.

// The trick is to define the NaN and Inf globals with a different type than the declaration.

// This trick works because the mangled name of the globals does not include the type, although

// I'm not sure that's guaranteed. There could be alignment issues with this, since arrays of

// characters don't necessarily need the same alignment doubles do, but for now it seems to work.

// It would be good to figure out a 100% clean way that still avoids code that runs at init time.

#if PLATFORM(DARWIN)

#if PLATFORM(BIG_ENDIAN)

    extern const unsigned char NaN[sizeof(double)] = { 0x7f, 0xf8, 0, 0, 0, 0, 0, 0 };

    extern const unsigned char Inf[sizeof(double)] = { 0x7f, 0xf0, 0, 0, 0, 0, 0, 0 };

#elif PLATFORM(MIDDLE_ENDIAN)

    extern const unsigned char NaN[] = { 0, 0, 0xf8, 0x7f, 0, 0, 0, 0 };

    extern const unsigned char Inf[] = { 0, 0, 0xf0, 0x7f, 0, 0, 0, 0 };

#else

    extern const unsigned char NaN[sizeof(double)] = { 0, 0, 0, 0, 0, 0, 0xf8, 0x7f };

    extern const unsigned char Inf[sizeof(double)] = { 0, 0, 0, 0, 0, 0, 0xf0, 0x7f };

#endif // PLATFORM(MIDDLE_ENDIAN)

#else // !PLATFORM(DARWIN)

// Note, we have to use union to ensure alignment. Otherwise, NaN_Bytes can start anywhere,

// while NaN_double has to be 4-byte aligned for 32-bits.

// With -fstrict-aliasing enabled, unions are the only safe way to do type masquerading.

static const union {

    struct {

        unsigned char NaN_Bytes[8];

        unsigned char Inf_Bytes[8];

    } bytes;

    struct {

        double NaN_Double;

        double Inf_Double;

    } doubles;

} NaNInf = { {

#if PLATFORM(BIG_ENDIAN)

    { 0x7f, 0xf8, 0, 0, 0, 0, 0, 0 },

    { 0x7f, 0xf0, 0, 0, 0, 0, 0, 0 }

#elif PLATFORM(MIDDLE_ENDIAN)

    { 0, 0, 0xf8, 0x7f, 0, 0, 0, 0 },

    { 0, 0, 0xf0, 0x7f, 0, 0, 0, 0 }

#else

    { 0, 0, 0, 0, 0, 0, 0xf8, 0x7f },

    { 0, 0, 0, 0, 0, 0, 0xf0, 0x7f }

#endif

} } ;

    extern const double NaN = NaNInf.doubles.NaN_Double;

    extern const double Inf = NaNInf.doubles.Inf_Double;

#endif // !PLATFORM(DARWIN)

} // namespace KJS