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/*

 * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers

 * Copyright (c) 1991-1995 by Xerox Corporation.  All rights reserved.

 * Copyright (c) 1997 by Silicon Graphics.  All rights reserved.

 * Copyright (c) 1999 by Hewlett-Packard Company.  All rights reserved.

 *

 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED

 * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.

 *

 * Permission is hereby granted to use or copy this program

 * for any purpose,  provided the above notices are retained on all copies.

 * Permission to modify the code and to distribute modified code is granted,

 * provided the above notices are retained, and a notice that the code was

 * modified is included with the above copyright notice.

 */

/*

 * This is mostly an internal header file.  Typical clients should

 * not use it.  Clients that define their own object kinds with

 * debugging allocators will probably want to include this, however.

 * No attempt is made to keep the namespace clean.  This should not be

 * included from header files that are frequently included by clients.

 */

#ifndef _DBG_MLC_H

#define _DBG_MLC_H

# define I_HIDE_POINTERS

# include "gc_priv.h"

# ifdef KEEP_BACK_PTRS

#   include "gc_backptr.h"

# endif

#ifndef HIDE_POINTER

  /* Gc.h was previously included, and hence the I_HIDE_POINTERS        */

  /* definition had no effect.  Repeat the gc.h definitions here to     */

  /* get them anyway.                                                   */

    typedef GC_word GC_hidden_pointer;

#   define HIDE_POINTER(p) (~(GC_hidden_pointer)(p))

#   define REVEAL_POINTER(p) ((GC_PTR)(HIDE_POINTER(p)))

#endif /* HIDE_POINTER */

# define START_FLAG ((word)0xfedcedcb)

# define END_FLAG ((word)0xbcdecdef)

        /* Stored both one past the end of user object, and one before  */

        /* the end of the object as seen by the allocator.              */

# if defined(KEEP_BACK_PTRS) || defined(PRINT_BLACK_LIST) \

     || defined(MAKE_BACK_GRAPH)

    /* Pointer "source"s that aren't real locations.    */

    /* Used in oh_back_ptr fields and as "source"       */

    /* argument to some marking functions.              */

#       define NOT_MARKED (ptr_t)(0)

#       define MARKED_FOR_FINALIZATION (ptr_t)(2)

            /* Object was marked because it is finalizable.     */

#       define MARKED_FROM_REGISTER (ptr_t)(4)

            /* Object was marked from a rgister.  Hence the     */

            /* source of the reference doesn't have an address. */

# endif /* KEEP_BACK_PTRS || PRINT_BLACK_LIST */

/* Object header */

typedef struct {

#   if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH)

        /* We potentially keep two different kinds of back      */

        /* pointers.  KEEP_BACK_PTRS stores a single back       */

        /* pointer in each reachable object to allow reporting  */

        /* of why an object was retained.  MAKE_BACK_GRAPH      */

        /* builds a graph containing the inverse of all         */

        /* "points-to" edges including those involving          */

        /* objects that have just become unreachable. This      */

        /* allows detection of growing chains of unreachable    */

        /* objects.  It may be possible to eventually combine   */

        /* both, but for now we keep them separate.  Both       */

        /* kinds of back pointers are hidden using the          */

        /* following macros.  In both cases, the plain version  */

        /* is constrained to have an least significant bit of 1,*/

        /* to allow it to be distinguished from a free list     */

        /* link.  This means the plain version must have an     */

        /* lsb of 0.                                            */

        /* Note that blocks dropped by black-listing will       */

        /* also have the lsb clear once debugging has           */

        /* started.                                             */

        /* We're careful never to overwrite a value with lsb 0. */

#       if ALIGNMENT == 1

          /* Fudge back pointer to be even.  */

#         define HIDE_BACK_PTR(p) HIDE_POINTER(~1 & (GC_word)(p))

#       else

#         define HIDE_BACK_PTR(p) HIDE_POINTER(p)

#       endif

#       ifdef KEEP_BACK_PTRS

          GC_hidden_pointer oh_back_ptr;

#       endif

#       ifdef MAKE_BACK_GRAPH

          GC_hidden_pointer oh_bg_ptr;

#       endif

#       if defined(ALIGN_DOUBLE) && \

            (defined(KEEP_BACK_PTRS) != defined(MAKE_BACK_GRAPH))

          word oh_dummy;

#       endif

#   endif

    GC_CONST char * oh_string;  /* object descriptor string     */

    word oh_int;                /* object descriptor integers   */

#   ifdef NEED_CALLINFO

      struct callinfo oh_ci[NFRAMES];

#   endif

#   ifndef SHORT_DBG_HDRS

      word oh_sz;                       /* Original malloc arg.         */

      word oh_sf;                       /* start flag */

#   endif /* SHORT_DBG_HDRS */

} oh;

/* The size of the above structure is assumed not to dealign things,    */

/* and to be a multiple of the word length.                             */

#ifdef SHORT_DBG_HDRS

#   define DEBUG_BYTES (sizeof (oh))

#   define UNCOLLECTABLE_DEBUG_BYTES DEBUG_BYTES

#else

    /* Add space for END_FLAG, but use any extra space that was already */

    /* added to catch off-the-end pointers.                             */

    /* For uncollectable objects, the extra byte is not added.          */

#   define UNCOLLECTABLE_DEBUG_BYTES (sizeof (oh) + sizeof (word))

#   define DEBUG_BYTES (UNCOLLECTABLE_DEBUG_BYTES - EXTRA_BYTES)

#endif

/* Round bytes to words without adding extra byte at end.       */

#define SIMPLE_ROUNDED_UP_WORDS(n) BYTES_TO_WORDS((n) + WORDS_TO_BYTES(1) - 1)

/* ADD_CALL_CHAIN stores a (partial) call chain into an object  */

/* header.  It may be called with or without the allocation     */

/* lock.                                                        */

/* PRINT_CALL_CHAIN prints the call chain stored in an object   */

/* to stderr.  It requires that we do not hold the lock.        */

#ifdef SAVE_CALL_CHAIN

#   define ADD_CALL_CHAIN(base, ra) GC_save_callers(((oh *)(base)) -> oh_ci)

#   define PRINT_CALL_CHAIN(base) GC_print_callers(((oh *)(base)) -> oh_ci)

#else

# ifdef GC_ADD_CALLER

#   define ADD_CALL_CHAIN(base, ra) ((oh *)(base)) -> oh_ci[0].ci_pc = (ra)

#   define PRINT_CALL_CHAIN(base) GC_print_callers(((oh *)(base)) -> oh_ci)

# else

#   define ADD_CALL_CHAIN(base, ra)

#   define PRINT_CALL_CHAIN(base)

# endif

#endif

# ifdef GC_ADD_CALLER

#   define OPT_RA ra,

# else

#   define OPT_RA

# endif

/* Check whether object with base pointer p has debugging info  */

/* p is assumed to point to a legitimate object in our part     */

/* of the heap.                                                 */

#ifdef SHORT_DBG_HDRS

# define GC_has_other_debug_info(p) TRUE

#else

  GC_bool GC_has_other_debug_info(/* p */);

#endif

#if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH)

# define GC_HAS_DEBUG_INFO(p) \

        ((*((word *)p) & 1) && GC_has_other_debug_info(p))

#else

# define GC_HAS_DEBUG_INFO(p) GC_has_other_debug_info(p)

#endif

/* Store debugging info into p.  Return displaced pointer. */

/* Assumes we don't hold allocation lock.                  */

ptr_t GC_store_debug_info(/* p, sz, string, integer */);

#endif /* _DBG_MLC_H */