1 /* Garbage collection for the GNU compiler. 2 3 Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 4 2008, 2009 Free Software Foundation, Inc. 5 6 This file is part of GCC. 7 8 GCC is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free 10 Software Foundation; either version 3, or (at your option) any later 11 version. 12 13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14 WARRANTY; without even the implied warranty of MERCHANTABILITY or 15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16 for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with GCC; see the file COPYING3. If not see 20 <http://www.gnu.org/licenses/>. */ 21 22 #ifndef GCC_GGC_H 23 #define GCC_GGC_H 24 #include "statistics.h" 25 26 /* Symbols are marked with `ggc' for `gcc gc' so as not to interfere with 27 an external gc library that might be linked in. */ 28 29 /* Constants for general use. */ 30 extern const char empty_string[]; /* empty string */ 31 extern const char digit_vector[]; /* "0" .. "9" */ 32 #define digit_string(d) (digit_vector + ((d) * 2)) 33 34 /* Internal functions and data structures used by the GTY 35 machinery. */ 36 37 /* The first parameter is a pointer to a pointer, the second a cookie. */ 38 typedef void (*gt_pointer_operator) (void *, void *); 39 40 #include "gtype-desc.h" 41 42 /* One of these applies its third parameter (with cookie in the fourth 43 parameter) to each pointer in the object pointed to by the first 44 parameter, using the second parameter. */ 45 typedef void (*gt_note_pointers) (void *, void *, gt_pointer_operator, 46 void *); 47 48 /* One of these is called before objects are re-ordered in memory. 49 The first parameter is the original object, the second is the 50 subobject that has had its pointers reordered, the third parameter 51 can compute the new values of a pointer when given the cookie in 52 the fourth parameter. */ 53 typedef void (*gt_handle_reorder) (void *, void *, gt_pointer_operator, 54 void *); 55 56 /* Used by the gt_pch_n_* routines. Register an object in the hash table. */ 57 extern int gt_pch_note_object (void *, void *, gt_note_pointers, 58 enum gt_types_enum); 59 60 /* Used by the gt_pch_n_* routines. Register that an object has a reorder 61 function. */ 62 extern void gt_pch_note_reorder (void *, void *, gt_handle_reorder); 63 64 /* Mark the object in the first parameter and anything it points to. */ 65 typedef void (*gt_pointer_walker) (void *); 66 67 /* Structures for the easy way to mark roots. 68 In an array, terminated by having base == NULL. */ 69 struct ggc_root_tab { 70 void *base; 71 size_t nelt; 72 size_t stride; 73 gt_pointer_walker cb; 74 gt_pointer_walker pchw; 75 }; 76 #define LAST_GGC_ROOT_TAB { NULL, 0, 0, NULL, NULL } 77 /* Pointers to arrays of ggc_root_tab, terminated by NULL. */ 78 extern const struct ggc_root_tab * const gt_ggc_rtab[]; 79 extern const struct ggc_root_tab * const gt_ggc_deletable_rtab[]; 80 extern const struct ggc_root_tab * const gt_pch_cache_rtab[]; 81 extern const struct ggc_root_tab * const gt_pch_scalar_rtab[]; 82 83 /* Structure for hash table cache marking. */ 84 struct htab; 85 struct ggc_cache_tab { 86 struct htab * *base; 87 size_t nelt; 88 size_t stride; 89 gt_pointer_walker cb; 90 gt_pointer_walker pchw; 91 int (*marked_p) (const void *); 92 }; 93 #define LAST_GGC_CACHE_TAB { NULL, 0, 0, NULL, NULL, NULL } 94 /* Pointers to arrays of ggc_cache_tab, terminated by NULL. */ 95 extern const struct ggc_cache_tab * const gt_ggc_cache_rtab[]; 96 97 /* If EXPR is not NULL and previously unmarked, mark it and evaluate 98 to true. Otherwise evaluate to false. */ 99 #define ggc_test_and_set_mark(EXPR) \ 100 ((EXPR) != NULL && ((void *) (EXPR)) != (void *) 1 && ! ggc_set_mark (EXPR)) 101 102 #define ggc_mark(EXPR) \ 103 do { \ 104 const void *const a__ = (EXPR); \ 105 if (a__ != NULL && a__ != (void *) 1) \ 106 ggc_set_mark (a__); \ 107 } while (0) 108 109 /* Actually set the mark on a particular region of memory, but don't 110 follow pointers. This function is called by ggc_mark_*. It 111 returns zero if the object was not previously marked; nonzero if 112 the object was already marked, or if, for any other reason, 113 pointers in this data structure should not be traversed. */ 114 extern int ggc_set_mark (const void *); 115 116 /* Return 1 if P has been marked, zero otherwise. 117 P must have been allocated by the GC allocator; it mustn't point to 118 static objects, stack variables, or memory allocated with malloc. */ 119 extern int ggc_marked_p (const void *); 120 121 /* Mark the entries in the string pool. */ 122 extern void ggc_mark_stringpool (void); 123 124 /* Purge the entries in the string pool. */ 125 extern void ggc_purge_stringpool (void); 126 127 /* Call ggc_set_mark on all the roots. */ 128 129 extern void ggc_mark_roots (void); 130 131 /* Save and restore the string pool entries for PCH. */ 132 133 extern void gt_pch_save_stringpool (void); 134 extern void gt_pch_fixup_stringpool (void); 135 extern void gt_pch_restore_stringpool (void); 136 137 /* PCH and GGC handling for strings, mostly trivial. */ 138 139 extern void gt_pch_p_S (void *, void *, gt_pointer_operator, void *); 140 extern void gt_pch_n_S (const void *); 141 extern void gt_ggc_m_S (const void *); 142 143 /* Initialize the string pool. */ 144 extern void init_stringpool (void); 145 146 /* A GC implementation must provide these functions. They are internal 147 to the GC system. */ 148 149 /* Forward declare the zone structure. Only ggc_zone implements this. */ 150 struct alloc_zone; 151 152 /* Initialize the garbage collector. */ 153 extern void init_ggc (void); 154 155 /* Start a new GGC zone. */ 156 extern struct alloc_zone *new_ggc_zone (const char *); 157 158 /* Free a complete GGC zone, destroying everything in it. */ 159 extern void destroy_ggc_zone (struct alloc_zone *); 160 161 struct ggc_pch_data; 162 163 /* Return a new ggc_pch_data structure. */ 164 extern struct ggc_pch_data *init_ggc_pch (void); 165 166 /* The second parameter and third parameters give the address and size 167 of an object. Update the ggc_pch_data structure with as much of 168 that information as is necessary. The bool argument should be true 169 if the object is a string. */ 170 extern void ggc_pch_count_object (struct ggc_pch_data *, void *, size_t, bool, 171 enum gt_types_enum); 172 173 /* Return the total size of the data to be written to hold all 174 the objects previously passed to ggc_pch_count_object. */ 175 extern size_t ggc_pch_total_size (struct ggc_pch_data *); 176 177 /* The objects, when read, will most likely be at the address 178 in the second parameter. */ 179 extern void ggc_pch_this_base (struct ggc_pch_data *, void *); 180 181 /* Assuming that the objects really do end up at the address 182 passed to ggc_pch_this_base, return the address of this object. 183 The bool argument should be true if the object is a string. */ 184 extern char *ggc_pch_alloc_object (struct ggc_pch_data *, void *, size_t, bool, 185 enum gt_types_enum); 186 187 /* Write out any initial information required. */ 188 extern void ggc_pch_prepare_write (struct ggc_pch_data *, FILE *); 189 /* Write out this object, including any padding. The last argument should be 190 true if the object is a string. */ 191 extern void ggc_pch_write_object (struct ggc_pch_data *, FILE *, void *, 192 void *, size_t, bool); 193 /* All objects have been written, write out any final information 194 required. */ 195 extern void ggc_pch_finish (struct ggc_pch_data *, FILE *); 196 197 /* A PCH file has just been read in at the address specified second 198 parameter. Set up the GC implementation for the new objects. */ 199 extern void ggc_pch_read (FILE *, void *); 200 201 202 /* Allocation. */ 204 205 /* When set, ggc_collect will do collection. */ 206 extern bool ggc_force_collect; 207 208 /* When true, identifier nodes are considered as GC roots. When 209 false, identifier nodes are treated like any other GC-allocated 210 object, and the identifier hash table is treated as a weak 211 hash. */ 212 extern bool ggc_protect_identifiers; 213 214 /* The internal primitive. */ 215 extern void *ggc_alloc_stat (size_t MEM_STAT_DECL); 216 #define ggc_alloc(s) ggc_alloc_stat (s MEM_STAT_INFO) 217 /* Allocate an object of the specified type and size. */ 218 extern void *ggc_alloc_typed_stat (enum gt_types_enum, size_t MEM_STAT_DECL); 219 #define ggc_alloc_typed(s,z) ggc_alloc_typed_stat (s,z MEM_STAT_INFO) 220 /* Like ggc_alloc, but allocates cleared memory. */ 221 extern void *ggc_alloc_cleared_stat (size_t MEM_STAT_DECL); 222 #define ggc_alloc_cleared(s) ggc_alloc_cleared_stat (s MEM_STAT_INFO) 223 /* Resize a block. */ 224 extern void *ggc_realloc_stat (void *, size_t MEM_STAT_DECL); 225 #define ggc_realloc(s,z) ggc_realloc_stat (s,z MEM_STAT_INFO) 226 /* Like ggc_alloc_cleared, but performs a multiplication. */ 227 extern void *ggc_calloc (size_t, size_t); 228 /* Free a block. To be used when known for certain it's not reachable. */ 229 extern void ggc_free (void *); 230 231 extern void ggc_record_overhead (size_t, size_t, void * MEM_STAT_DECL); 232 extern void ggc_free_overhead (void *); 233 extern void ggc_prune_overhead_list (void); 234 235 extern void dump_ggc_loc_statistics (bool); 236 237 /* Type-safe, C++-friendly versions of ggc_alloc() and gcc_calloc(). */ 238 #define GGC_NEW(T) ((T *) ggc_alloc (sizeof (T))) 239 #define GGC_CNEW(T) ((T *) ggc_alloc_cleared (sizeof (T))) 240 #define GGC_NEWVEC(T, N) ((T *) ggc_alloc ((N) * sizeof(T))) 241 #define GGC_CNEWVEC(T, N) ((T *) ggc_alloc_cleared ((N) * sizeof(T))) 242 #define GGC_RESIZEVEC(T, P, N) ((T *) ggc_realloc ((P), (N) * sizeof (T))) 243 #define GGC_NEWVAR(T, S) ((T *) ggc_alloc ((S))) 244 #define GGC_CNEWVAR(T, S) ((T *) ggc_alloc_cleared ((S))) 245 #define GGC_RESIZEVAR(T, P, N) ((T *) ggc_realloc ((P), (N))) 246 247 #define ggc_alloc_rtvec(NELT) \ 248 ((rtvec) ggc_alloc_zone (sizeof (struct rtvec_def) + ((NELT) - 1) \ 249 * sizeof (rtx), &rtl_zone)) 250 251 #define ggc_alloc_tree(LENGTH) ((tree) ggc_alloc_zone (LENGTH, &tree_zone)) 252 253 #define htab_create_ggc(SIZE, HASH, EQ, DEL) \ 254 htab_create_alloc (SIZE, HASH, EQ, DEL, ggc_calloc, ggc_free) 255 256 #define splay_tree_new_ggc(COMPARE) \ 257 splay_tree_new_with_allocator (COMPARE, NULL, NULL, \ 258 &ggc_splay_alloc, &ggc_splay_dont_free, \ 259 NULL) 260 extern void *ggc_splay_alloc (int, void *); 261 extern void ggc_splay_dont_free (void *, void *); 262 263 /* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS. 264 If LENGTH is -1, then CONTENTS is assumed to be a 265 null-terminated string and the memory sized accordingly. */ 266 extern const char *ggc_alloc_string (const char *contents, int length); 267 268 /* Make a copy of S, in GC-able memory. */ 269 #define ggc_strdup(S) ggc_alloc_string((S), -1) 270 271 /* Invoke the collector. Garbage collection occurs only when this 272 function is called, not during allocations. */ 273 extern void ggc_collect (void); 274 275 /* Register an additional root table. This can be useful for some 276 plugins. Does nothing if the passed pointer is null. */ 277 extern void ggc_register_root_tab (const struct ggc_root_tab *); 278 279 /* Return the number of bytes allocated at the indicated address. */ 280 extern size_t ggc_get_size (const void *); 281 282 /* Write out all GCed objects to F. */ 283 extern void gt_pch_save (FILE *f); 284 285 /* Read objects previously saved with gt_pch_save from F. */ 286 extern void gt_pch_restore (FILE *f); 287 288 /* Statistics. */ 290 291 /* This structure contains the statistics common to all collectors. 292 Particular collectors can extend this structure. */ 293 typedef struct ggc_statistics 294 { 295 /* At present, we don't really gather any interesting statistics. */ 296 int unused; 297 } ggc_statistics; 298 299 /* Used by the various collectors to gather and print statistics that 300 do not depend on the collector in use. */ 301 extern void ggc_print_common_statistics (FILE *, ggc_statistics *); 302 303 /* Print allocation statistics. */ 304 extern void ggc_print_statistics (void); 305 extern void stringpool_statistics (void); 306 307 /* Heuristics. */ 308 extern int ggc_min_expand_heuristic (void); 309 extern int ggc_min_heapsize_heuristic (void); 310 extern void init_ggc_heuristics (void); 311 312 /* Zone collection. */ 313 #if defined (GGC_ZONE) && !defined (GENERATOR_FILE) 314 315 /* For regular rtl allocations. */ 316 extern struct alloc_zone rtl_zone; 317 /* For regular tree allocations. */ 318 extern struct alloc_zone tree_zone; 319 /* For IDENTIFIER_NODE allocations. */ 320 extern struct alloc_zone tree_id_zone; 321 322 /* Allocate an object into the specified allocation zone. */ 323 extern void *ggc_alloc_zone_stat (size_t, struct alloc_zone * MEM_STAT_DECL); 324 # define ggc_alloc_zone(s,z) ggc_alloc_zone_stat (s,z MEM_STAT_INFO) 325 # define ggc_alloc_zone_pass_stat(s,z) ggc_alloc_zone_stat (s,z PASS_MEM_STAT) 326 #else 327 328 # define ggc_alloc_zone(s, z) ggc_alloc (s) 329 # define ggc_alloc_zone_pass_stat(s, z) ggc_alloc_stat (s PASS_MEM_STAT) 330 331 #endif 332 333 #endif 334
