1 /* 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. 6 * 7 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED 8 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. 9 * 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. 15 */ 16 17 /* 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. 23 */ 24 25 #ifndef _DBG_MLC_H 26 27 #define _DBG_MLC_H 28 29 # define I_HIDE_POINTERS 30 # include "gc_priv.h" 31 # ifdef KEEP_BACK_PTRS 32 # include "gc_backptr.h" 33 # endif 34 35 #ifndef HIDE_POINTER 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) ((GC_PTR)(HIDE_POINTER(p))) 42 #endif /* HIDE_POINTER */ 43 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. */ 48 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 */ 61 62 /* Object header */ 63 typedef struct { 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 */ 80 /* lsb of 0. */ 81 /* Note that blocks dropped by black-listing will */ 82 /* also have the lsb clear once debugging has */ 83 /* started. */ 84 /* We're careful never to overwrite a value with lsb 0. */ 85 # if ALIGNMENT == 1 86 /* Fudge back pointer to be even. */ 87 # define HIDE_BACK_PTR(p) HIDE_POINTER(~1 & (GC_word)(p)) 88 # else 89 # define HIDE_BACK_PTR(p) HIDE_POINTER(p) 90 # endif 91 92 # ifdef KEEP_BACK_PTRS 93 GC_hidden_pointer oh_back_ptr; 94 # endif 95 # ifdef MAKE_BACK_GRAPH 96 GC_hidden_pointer oh_bg_ptr; 97 # endif 98 # if defined(ALIGN_DOUBLE) && \ 99 (defined(KEEP_BACK_PTRS) != defined(MAKE_BACK_GRAPH)) 100 word oh_dummy; 101 # endif 102 # endif 103 GC_CONST char * oh_string; /* object descriptor string */ 104 word oh_int; /* object descriptor integers */ 105 # ifdef NEED_CALLINFO 106 struct callinfo oh_ci[NFRAMES]; 107 # endif 108 # ifndef SHORT_DBG_HDRS 109 word oh_sz; /* Original malloc arg. */ 110 word oh_sf; /* start flag */ 111 # endif /* SHORT_DBG_HDRS */ 112 } oh; 113 /* The size of the above structure is assumed not to dealign things, */ 114 /* and to be a multiple of the word length. */ 115 116 #ifdef SHORT_DBG_HDRS 117 # define DEBUG_BYTES (sizeof (oh)) 118 # define UNCOLLECTABLE_DEBUG_BYTES DEBUG_BYTES 119 #else 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) 125 #endif 126 127 /* 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) 129 130 /* ADD_CALL_CHAIN stores a (partial) call chain into an object */ 131 /* header. It may be called with or without the allocation */ 132 /* lock. */ 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 #ifdef SAVE_CALL_CHAIN 136 # define ADD_CALL_CHAIN(base, ra) GC_save_callers(((oh *)(base)) -> oh_ci) 137 # define PRINT_CALL_CHAIN(base) GC_print_callers(((oh *)(base)) -> oh_ci) 138 #else 139 # ifdef GC_ADD_CALLER 140 # define ADD_CALL_CHAIN(base, ra) ((oh *)(base)) -> oh_ci[0].ci_pc = (ra) 141 # define PRINT_CALL_CHAIN(base) GC_print_callers(((oh *)(base)) -> oh_ci) 142 # else 143 # define ADD_CALL_CHAIN(base, ra) 144 # define PRINT_CALL_CHAIN(base) 145 # endif 146 #endif 147 148 # ifdef GC_ADD_CALLER 149 # define OPT_RA ra, 150 # else 151 # define OPT_RA 152 # endif 153 154 155 /* Check whether object with base pointer p has debugging info */ 156 /* p is assumed to point to a legitimate object in our part */ 157 /* of the heap. */ 158 #ifdef SHORT_DBG_HDRS 159 # define GC_has_other_debug_info(p) TRUE 160 #else 161 GC_bool GC_has_other_debug_info(/* p */); 162 #endif 163 164 #if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH) 165 # define GC_HAS_DEBUG_INFO(p) \ 166 ((*((word *)p) & 1) && GC_has_other_debug_info(p)) 167 #else 168 # define GC_HAS_DEBUG_INFO(p) GC_has_other_debug_info(p) 169 #endif 170 171 /* Store debugging info into p. Return displaced pointer. */ 172 /* Assumes we don't hold allocation lock. */ 173 ptr_t GC_store_debug_info(/* p, sz, string, integer */); 174 175 #endif /* _DBG_MLC_H */ 176