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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 GC_DBG_MLC_H
#define GC_DBG_MLC_H
#include "gc_priv.h"
#ifdef KEEP_BACK_PTRS
# include "gc/gc_backptr.h"
#endif
EXTERN_C_BEGIN
#if CPP_WORDSZ == 32
# define START_FLAG (word)0xfedcedcb
# define END_FLAG (word)0xbcdecdef
#else
# define START_FLAG GC_WORD_C(0xFEDCEDCBfedcedcb)
# define END_FLAG GC_WORD_C(0xBCDECDEFbcdecdef)
#endif
/* 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)(word)2)
/* Object was marked because it is finalizable. */
# define MARKED_FROM_REGISTER ((ptr_t)(word)4)
/* Object was marked from a register. 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) GC_HIDE_POINTER(~1 & (word)(p))
# else
# define HIDE_BACK_PTR(p) GC_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(KEEP_BACK_PTRS) != defined(MAKE_BACK_GRAPH)
/* Keep double-pointer-sized alignment. */
word oh_dummy;
# endif
# endif
const char * oh_string; /* object descriptor string (file name) */
signed_word oh_int; /* object descriptor integer (line number) */
# 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 de-align 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 uncollectible 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 should be called with the allocation lock held. */
/* PRINT_CALL_CHAIN prints the call chain stored in an object */
/* to stderr. It requires that we do not hold the lock. */
#if defined(SAVE_CALL_CHAIN)
struct callinfo;
GC_INNER void GC_save_callers(struct callinfo info[NFRAMES]);
GC_INNER void GC_print_callers(struct callinfo info[NFRAMES]);
# 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)
#elif defined(GC_ADD_CALLER)
struct callinfo;
GC_INNER void GC_print_callers(struct callinfo info[NFRAMES]);
# 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
#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) 1
#else
GC_INNER int GC_has_other_debug_info(ptr_t p);
#endif
#if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH)
# if defined(SHORT_DBG_HDRS) && !defined(CPPCHECK)
# error Non-ptr stored in object results in GC_HAS_DEBUG_INFO malfunction
/* We may mistakenly conclude that p has a debugging wrapper. */
# endif
# if defined(PARALLEL_MARK) && defined(KEEP_BACK_PTRS)
# define GC_HAS_DEBUG_INFO(p) \
((AO_load((volatile AO_t *)(p)) & 1) != 0 \
&& GC_has_other_debug_info(p) > 0)
/* Atomic load is used as GC_store_back_pointer */
/* stores oh_back_ptr atomically (p might point */
/* to the field); this prevents a TSan warning. */
# else
# define GC_HAS_DEBUG_INFO(p) \
((*(word *)(p) & 1) && GC_has_other_debug_info(p) > 0)
# endif
#else
# define GC_HAS_DEBUG_INFO(p) (GC_has_other_debug_info(p) > 0)
#endif /* !KEEP_BACK_PTRS && !MAKE_BACK_GRAPH */
EXTERN_C_END
#endif /* GC_DBG_MLC_H */
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