/* ssw3i3pc.c: STACK SCANNING FOR WIN32 WITH PELLES C
 *
 * $Id: //info.ravenbrook.com/project/mps/version/1.116/code/ssw3i3pc.c#1 $
 * Copyright (c) 2001-2014 Ravenbrook Limited.  See end of file for license.
 *
 * This scans the stack and fixes the registers which may contain roots.
 * See <design/thread-manager/>.
 *
 * .assume.ms-compat: We rely on the fact that Pelles C's setjmp stores
 * the callee-save registers in the jmp_buf and is compatible with Microsoft
 * C.  The Pelles C 7.00 setjmp.h header has a comment "MS compatible".  See
 * also "Is Pelles C's jmp_buf compatible with Microsoft C's?"
 * <http://forum.pellesc.de/index.php?topic=5464>
 *
 * REFERENCES
 *
 * "Argument Passing and Naming Conventions"; MSDN; Microsoft Corporation;
 * <http://msdn.microsoft.com/en-us/library/984x0h58%28v=vs.100%29.aspx>.
 *
 * "Calling conventions for different C++ compilers and operating systems";
 * Agner Fog; Copenhagen University College of Engineering; 2012-02-29;
 * <http://agner.org./optimize/calling_conventions.pdf>.
 */

#include "mpm.h"
#include <setjmp.h>

SRCID(ssw3i3pc, "$Id: //info.ravenbrook.com/project/mps/version/1.116/code/ssw3i3pc.c#1 $");


/* This definition isn't in the Pelles C headers, so we reproduce it here.
 * See .assume.ms-compat. */

typedef struct __JUMP_BUFFER {
    unsigned long Ebp;
    unsigned long Ebx;
    unsigned long Edi;
    unsigned long Esi;
    unsigned long Esp;
    unsigned long Eip;
    unsigned long Registration;
    unsigned long TryLevel;
    unsigned long Cookie;
    unsigned long UnwindFunc;
    unsigned long UnwindData[6];
} _JUMP_BUFFER;


Res StackScan(ScanState ss, Word *stackCold,
              mps_area_scan_t scan_area,
              void *closure)
{
  jmp_buf jb;

  /* .assume.ms-compat */
  (void)setjmp(jb);

  /* These checks, on the _JUMP_BUFFER defined above, are mainly here
   * to maintain similarity to the matching code on the MPS_BUILD_MV
   * version of this code. */
  AVER(sizeof(((_JUMP_BUFFER *)jb)->Ebx) == sizeof(Word));
  AVER(sizeof(((_JUMP_BUFFER *)jb)->Edi) == sizeof(Word));
  AVER(sizeof(((_JUMP_BUFFER *)jb)->Esi) == sizeof(Word));

  /* Ensure that the callee-save registers will be found by
     StackScanInner when it's passed the address of the Ebx field. */
  AVER(offsetof(_JUMP_BUFFER, Edi) == offsetof(_JUMP_BUFFER, Ebx) + 4);
  AVER(offsetof(_JUMP_BUFFER, Esi) == offsetof(_JUMP_BUFFER, Ebx) + 8);

  return StackScanInner(ss, stackCold, (Word *)&((_JUMP_BUFFER *)jb)->Ebx, 3,
                        scan_area, closure);
}


/* C. COPYRIGHT AND LICENSE
 *
 * Copyright (C) 2001-2014 Ravenbrook Limited <http://www.ravenbrook.com/>.
 * All rights reserved.  This is an open source license.  Contact
 * Ravenbrook for commercial licensing options.
 * 
 * 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. Redistributions in any form must be accompanied by information on how
 * to obtain complete source code for this software and any accompanying
 * software that uses this software.  The source code must either be
 * included in the distribution or be available for no more than the cost
 * of distribution plus a nominal fee, and must be freely redistributable
 * under reasonable conditions.  For an executable file, complete source
 * code means the source code for all modules it contains. It does not
 * include source code for modules or files that typically accompany the
 * major components of the operating system on which the executable file
 * runs.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS AND 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
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 */