2 * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
3 * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved.
4 * Copyright (c) 1997 by Silicon Graphics. All rights reserved.
5 * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
7 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
8 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
10 * Permission is hereby granted to use or copy this program
11 * for any purpose, provided the above notices are retained on all copies.
12 * Permission to modify the code and to distribute modified code is granted,
13 * provided the above notices are retained, and a notice that the code was
14 * modified is included with the above copyright notice.
18 * This is mostly an internal header file. Typical clients should
19 * not use it. Clients that define their own object kinds with
20 * debugging allocators will probably want to include this, however.
21 * No attempt is made to keep the namespace clean. This should not be
22 * included from header files that are frequently included by clients.
29 # ifdef KEEP_BACK_PTRS
30 # include "gc_backptr.h"
33 # define START_FLAG ((word)0xfedcedcb)
34 # define END_FLAG ((word)0xbcdecdef)
35 /* Stored both one past the end of user object, and one before */
36 /* the end of the object as seen by the allocator. */
38 # if defined(KEEP_BACK_PTRS) || defined(PRINT_BLACK_LIST) \
39 || defined(MAKE_BACK_GRAPH)
40 /* Pointer "source"s that aren't real locations. */
41 /* Used in oh_back_ptr fields and as "source" */
42 /* argument to some marking functions. */
43 # define NOT_MARKED (ptr_t)(0)
44 # define MARKED_FOR_FINALIZATION ((ptr_t)(word)2)
45 /* Object was marked because it is finalizable. */
46 # define MARKED_FROM_REGISTER ((ptr_t)(word)4)
47 /* Object was marked from a register. Hence the */
48 /* source of the reference doesn't have an address. */
49 # endif /* KEEP_BACK_PTRS || PRINT_BLACK_LIST */
53 # if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH)
54 /* We potentially keep two different kinds of back */
55 /* pointers. KEEP_BACK_PTRS stores a single back */
56 /* pointer in each reachable object to allow reporting */
57 /* of why an object was retained. MAKE_BACK_GRAPH */
58 /* builds a graph containing the inverse of all */
59 /* "points-to" edges including those involving */
60 /* objects that have just become unreachable. This */
61 /* allows detection of growing chains of unreachable */
62 /* objects. It may be possible to eventually combine */
63 /* both, but for now we keep them separate. Both */
64 /* kinds of back pointers are hidden using the */
65 /* following macros. In both cases, the plain version */
66 /* is constrained to have an least significant bit of 1,*/
67 /* to allow it to be distinguished from a free list */
68 /* link. This means the plain version must have an */
70 /* Note that blocks dropped by black-listing will */
71 /* also have the lsb clear once debugging has */
73 /* We're careful never to overwrite a value with lsb 0. */
75 /* Fudge back pointer to be even. */
76 # define HIDE_BACK_PTR(p) GC_HIDE_POINTER(~1 & (GC_word)(p))
78 # define HIDE_BACK_PTR(p) GC_HIDE_POINTER(p)
81 # ifdef KEEP_BACK_PTRS
82 GC_hidden_pointer oh_back_ptr;
84 # ifdef MAKE_BACK_GRAPH
85 GC_hidden_pointer oh_bg_ptr;
87 # if defined(KEEP_BACK_PTRS) != defined(MAKE_BACK_GRAPH)
88 /* Keep double-pointer-sized alignment. */
92 const char * oh_string; /* object descriptor string */
93 word oh_int; /* object descriptor integers */
95 struct callinfo oh_ci[NFRAMES];
97 # ifndef SHORT_DBG_HDRS
98 word oh_sz; /* Original malloc arg. */
99 word oh_sf; /* start flag */
100 # endif /* SHORT_DBG_HDRS */
102 /* The size of the above structure is assumed not to de-align things, */
103 /* and to be a multiple of the word length. */
105 #ifdef SHORT_DBG_HDRS
106 # define DEBUG_BYTES (sizeof (oh))
107 # define UNCOLLECTABLE_DEBUG_BYTES DEBUG_BYTES
109 /* Add space for END_FLAG, but use any extra space that was already */
110 /* added to catch off-the-end pointers. */
111 /* For uncollectable objects, the extra byte is not added. */
112 # define UNCOLLECTABLE_DEBUG_BYTES (sizeof (oh) + sizeof (word))
113 # define DEBUG_BYTES (UNCOLLECTABLE_DEBUG_BYTES - EXTRA_BYTES)
116 /* Round bytes to words without adding extra byte at end. */
117 #define SIMPLE_ROUNDED_UP_WORDS(n) BYTES_TO_WORDS((n) + WORDS_TO_BYTES(1) - 1)
119 /* ADD_CALL_CHAIN stores a (partial) call chain into an object */
120 /* header. It may be called with or without the allocation */
122 /* PRINT_CALL_CHAIN prints the call chain stored in an object */
123 /* to stderr. It requires that we do not hold the lock. */
124 #if defined(SAVE_CALL_CHAIN)
126 GC_INNER void GC_save_callers(struct callinfo info[NFRAMES]);
127 GC_INNER void GC_print_callers(struct callinfo info[NFRAMES]);
128 # define ADD_CALL_CHAIN(base, ra) GC_save_callers(((oh *)(base)) -> oh_ci)
129 # define PRINT_CALL_CHAIN(base) GC_print_callers(((oh *)(base)) -> oh_ci)
130 #elif defined(GC_ADD_CALLER)
132 GC_INNER void GC_print_callers(struct callinfo info[NFRAMES]);
133 # define ADD_CALL_CHAIN(base, ra) ((oh *)(base)) -> oh_ci[0].ci_pc = (ra)
134 # define PRINT_CALL_CHAIN(base) GC_print_callers(((oh *)(base)) -> oh_ci)
136 # define ADD_CALL_CHAIN(base, ra)
137 # define PRINT_CALL_CHAIN(base)
140 # ifdef GC_ADD_CALLER
147 /* Check whether object with base pointer p has debugging info */
148 /* p is assumed to point to a legitimate object in our part */
150 #ifdef SHORT_DBG_HDRS
151 # define GC_has_other_debug_info(p) TRUE
153 GC_INNER GC_bool GC_has_other_debug_info(ptr_t p);
156 #if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH)
157 # define GC_HAS_DEBUG_INFO(p) \
158 ((*((word *)p) & 1) && GC_has_other_debug_info(p))
160 # define GC_HAS_DEBUG_INFO(p) GC_has_other_debug_info(p)
163 /* Store debugging info into p. Return displaced pointer. */
164 /* Assumes we don't hold allocation lock. */
165 GC_INNER ptr_t GC_store_debug_info(ptr_t p, word sz, const char *str,
168 #endif /* _DBG_MLC_H */