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 # define I_HIDE_POINTERS
31 # ifdef KEEP_BACK_PTRS
32 # include "gc_backptr.h"
36 /* Gc.h was previously included, and hence the I_HIDE_POINTERS */
37 /* definition had no effect. Repeat the gc.h definitions here to */
38 /* get them anyway. */
39 typedef GC_word GC_hidden_pointer;
40 # define HIDE_POINTER(p) (~(GC_hidden_pointer)(p))
41 # define REVEAL_POINTER(p) ((void *)(HIDE_POINTER(p)))
42 #endif /* HIDE_POINTER */
44 # define START_FLAG ((word)0xfedcedcb)
45 # define END_FLAG ((word)0xbcdecdef)
46 /* Stored both one past the end of user object, and one before */
47 /* the end of the object as seen by the allocator. */
49 # if defined(KEEP_BACK_PTRS) || defined(PRINT_BLACK_LIST) \
50 || defined(MAKE_BACK_GRAPH)
51 /* Pointer "source"s that aren't real locations. */
52 /* Used in oh_back_ptr fields and as "source" */
53 /* argument to some marking functions. */
54 # define NOT_MARKED (ptr_t)(0)
55 # define MARKED_FOR_FINALIZATION (ptr_t)(2)
56 /* Object was marked because it is finalizable. */
57 # define MARKED_FROM_REGISTER (ptr_t)(4)
58 /* Object was marked from a rgister. Hence the */
59 /* source of the reference doesn't have an address. */
60 # endif /* KEEP_BACK_PTRS || PRINT_BLACK_LIST */
64 # if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH)
65 /* We potentially keep two different kinds of back */
66 /* pointers. KEEP_BACK_PTRS stores a single back */
67 /* pointer in each reachable object to allow reporting */
68 /* of why an object was retained. MAKE_BACK_GRAPH */
69 /* builds a graph containing the inverse of all */
70 /* "points-to" edges including those involving */
71 /* objects that have just become unreachable. This */
72 /* allows detection of growing chains of unreachable */
73 /* objects. It may be possible to eventually combine */
74 /* both, but for now we keep them separate. Both */
75 /* kinds of back pointers are hidden using the */
76 /* following macros. In both cases, the plain version */
77 /* is constrained to have an least significant bit of 1,*/
78 /* to allow it to be distinguished from a free list */
79 /* link. This means the plain version must have an */
81 /* Note that blocks dropped by black-listing will */
82 /* also have the lsb clear once debugging has */
84 /* We're careful never to overwrite a value with lsb 0. */
86 /* Fudge back pointer to be even. */
87 # define HIDE_BACK_PTR(p) HIDE_POINTER(~1 & (GC_word)(p))
89 # define HIDE_BACK_PTR(p) HIDE_POINTER(p)
92 # ifdef KEEP_BACK_PTRS
93 GC_hidden_pointer oh_back_ptr;
95 # ifdef MAKE_BACK_GRAPH
96 GC_hidden_pointer oh_bg_ptr;
98 # if defined(KEEP_BACK_PTRS) != defined(MAKE_BACK_GRAPH)
99 /* Keep double-pointer-sized alignment. */
103 const char * oh_string; /* object descriptor string */
104 word oh_int; /* object descriptor integers */
105 # ifdef NEED_CALLINFO
106 struct callinfo oh_ci[NFRAMES];
108 # ifndef SHORT_DBG_HDRS
109 word oh_sz; /* Original malloc arg. */
110 word oh_sf; /* start flag */
111 # endif /* SHORT_DBG_HDRS */
113 /* The size of the above structure is assumed not to dealign things, */
114 /* and to be a multiple of the word length. */
116 #ifdef SHORT_DBG_HDRS
117 # define DEBUG_BYTES (sizeof (oh))
118 # define UNCOLLECTABLE_DEBUG_BYTES DEBUG_BYTES
120 /* Add space for END_FLAG, but use any extra space that was already */
121 /* added to catch off-the-end pointers. */
122 /* For uncollectable objects, the extra byte is not added. */
123 # define UNCOLLECTABLE_DEBUG_BYTES (sizeof (oh) + sizeof (word))
124 # define DEBUG_BYTES (UNCOLLECTABLE_DEBUG_BYTES - EXTRA_BYTES)
127 /* Round bytes to words without adding extra byte at end. */
128 #define SIMPLE_ROUNDED_UP_WORDS(n) BYTES_TO_WORDS((n) + WORDS_TO_BYTES(1) - 1)
130 /* ADD_CALL_CHAIN stores a (partial) call chain into an object */
131 /* header. It may be called with or without the allocation */
133 /* PRINT_CALL_CHAIN prints the call chain stored in an object */
134 /* to stderr. It requires that we do not hold the lock. */
135 #if defined(SAVE_CALL_CHAIN)
137 void GC_save_callers(struct callinfo info[NFRAMES]);
138 void GC_print_callers(struct callinfo info[NFRAMES]);
139 # define ADD_CALL_CHAIN(base, ra) GC_save_callers(((oh *)(base)) -> oh_ci)
140 # define PRINT_CALL_CHAIN(base) GC_print_callers(((oh *)(base)) -> oh_ci)
141 #elif defined(GC_ADD_CALLER)
143 void GC_print_callers(struct callinfo info[NFRAMES]);
144 # define ADD_CALL_CHAIN(base, ra) ((oh *)(base)) -> oh_ci[0].ci_pc = (ra)
145 # define PRINT_CALL_CHAIN(base) GC_print_callers(((oh *)(base)) -> oh_ci)
147 # define ADD_CALL_CHAIN(base, ra)
148 # define PRINT_CALL_CHAIN(base)
151 # ifdef GC_ADD_CALLER
158 /* Check whether object with base pointer p has debugging info */
159 /* p is assumed to point to a legitimate object in our part */
161 #ifdef SHORT_DBG_HDRS
162 # define GC_has_other_debug_info(p) TRUE
164 GC_bool GC_has_other_debug_info(/* p */);
167 #if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH)
168 # define GC_HAS_DEBUG_INFO(p) \
169 ((*((word *)p) & 1) && GC_has_other_debug_info(p))
171 # define GC_HAS_DEBUG_INFO(p) GC_has_other_debug_info(p)
174 /* Store debugging info into p. Return displaced pointer. */
175 /* Assumes we don't hold allocation lock. */
176 ptr_t GC_store_debug_info(/* p, sz, string, integer */);
178 #endif /* _DBG_MLC_H */