1 /* Garbage collection for the GNU compiler. 2 3 Copyright (C) 1998-2018 Free Software Foundation, Inc. 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify it under 8 the terms of the GNU General Public License as published by the Free 9 Software Foundation; either version 3, or (at your option) any later 10 version. 11 12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13 WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with GCC; see the file COPYING3. If not see 19 <http://www.gnu.org/licenses/>. */ 20 21 #ifndef GCC_GGC_H 22 #define GCC_GGC_H 23 24 /* Symbols are marked with `ggc' for `gcc gc' so as not to interfere with 25 an external gc library that might be linked in. */ 26 27 /* Internal functions and data structures used by the GTY 28 machinery, including the generated gt*.[hc] files. */ 29 30 #include "gtype-desc.h" 31 32 /* One of these applies its third parameter (with cookie in the fourth 33 parameter) to each pointer in the object pointed to by the first 34 parameter, using the second parameter. */ 35 typedef void (*gt_note_pointers) (void *, void *, gt_pointer_operator, 36 void *); 37 38 /* One of these is called before objects are re-ordered in memory. 39 The first parameter is the original object, the second is the 40 subobject that has had its pointers reordered, the third parameter 41 can compute the new values of a pointer when given the cookie in 42 the fourth parameter. */ 43 typedef void (*gt_handle_reorder) (void *, void *, gt_pointer_operator, 44 void *); 45 46 /* Used by the gt_pch_n_* routines. Register an object in the hash table. */ 47 extern int gt_pch_note_object (void *, void *, gt_note_pointers); 48 49 /* Used by the gt_pch_n_* routines. Register that an object has a reorder 50 function. */ 51 extern void gt_pch_note_reorder (void *, void *, gt_handle_reorder); 52 53 /* generated function to clear caches in gc memory. */ 54 extern void gt_clear_caches (); 55 56 /* Mark the object in the first parameter and anything it points to. */ 57 typedef void (*gt_pointer_walker) (void *); 58 59 /* Structures for the easy way to mark roots. 60 In an array, terminated by having base == NULL. */ 61 struct ggc_root_tab { 62 void *base; 63 size_t nelt; 64 size_t stride; 65 gt_pointer_walker cb; 66 gt_pointer_walker pchw; 67 }; 68 #define LAST_GGC_ROOT_TAB { NULL, 0, 0, NULL, NULL } 69 /* Pointers to arrays of ggc_root_tab, terminated by NULL. */ 70 extern const struct ggc_root_tab * const gt_ggc_rtab[]; 71 extern const struct ggc_root_tab * const gt_ggc_deletable_rtab[]; 72 extern const struct ggc_root_tab * const gt_pch_scalar_rtab[]; 73 74 /* If EXPR is not NULL and previously unmarked, mark it and evaluate 75 to true. Otherwise evaluate to false. */ 76 #define ggc_test_and_set_mark(EXPR) \ 77 ((EXPR) != NULL && ((void *) (EXPR)) != (void *) 1 && ! ggc_set_mark (EXPR)) 78 79 #define ggc_mark(EXPR) \ 80 do { \ 81 const void *const a__ = (EXPR); \ 82 if (a__ != NULL && a__ != (void *) 1) \ 83 ggc_set_mark (a__); \ 84 } while (0) 85 86 /* Actually set the mark on a particular region of memory, but don't 87 follow pointers. This function is called by ggc_mark_*. It 88 returns zero if the object was not previously marked; nonzero if 89 the object was already marked, or if, for any other reason, 90 pointers in this data structure should not be traversed. */ 91 extern int ggc_set_mark (const void *); 92 93 /* Return 1 if P has been marked, zero otherwise. 94 P must have been allocated by the GC allocator; it mustn't point to 95 static objects, stack variables, or memory allocated with malloc. */ 96 extern int ggc_marked_p (const void *); 97 98 /* PCH and GGC handling for strings, mostly trivial. */ 99 extern void gt_pch_n_S (const void *); 100 extern void gt_ggc_m_S (const void *); 101 102 /* End of GTY machinery API. */ 103 104 /* Initialize the string pool. */ 105 extern void init_stringpool (void); 106 107 /* Initialize the garbage collector. */ 108 extern void init_ggc (void); 109 110 /* When true, identifier nodes are considered as GC roots. When 111 false, identifier nodes are treated like any other GC-allocated 112 object, and the identifier hash table is treated as a weak 113 hash. */ 114 extern bool ggc_protect_identifiers; 115 116 /* Write out all GCed objects to F. */ 117 extern void gt_pch_save (FILE *f); 118 119 120 /* Allocation. */ 121 122 /* The internal primitive. */ 123 extern void *ggc_internal_alloc (size_t, void (*)(void *), size_t, 124 size_t CXX_MEM_STAT_INFO) 125 ATTRIBUTE_MALLOC; 126 127 inline void * 128 ggc_internal_alloc (size_t s CXX_MEM_STAT_INFO) 129 { 130 return ggc_internal_alloc (s, NULL, 0, 1 PASS_MEM_STAT); 131 } 132 133 extern size_t ggc_round_alloc_size (size_t requested_size); 134 135 /* Allocates cleared memory. */ 136 extern void *ggc_internal_cleared_alloc (size_t, void (*)(void *), 137 size_t, size_t 138 CXX_MEM_STAT_INFO) ATTRIBUTE_MALLOC; 139 140 inline void * 141 ggc_internal_cleared_alloc (size_t s CXX_MEM_STAT_INFO) 142 { 143 return ggc_internal_cleared_alloc (s, NULL, 0, 1 PASS_MEM_STAT); 144 } 145 146 /* Resize a block. */ 147 extern void *ggc_realloc (void *, size_t CXX_MEM_STAT_INFO); 148 149 /* Free a block. To be used when known for certain it's not reachable. */ 150 extern void ggc_free (void *); 151 152 extern void dump_ggc_loc_statistics (bool); 153 154 /* Reallocator. */ 155 #define GGC_RESIZEVEC(T, P, N) \ 156 ((T *) ggc_realloc ((P), (N) * sizeof (T) MEM_STAT_INFO)) 157 158 template<typename T> 159 void 160 finalize (void *p) 161 { 162 static_cast<T *> (p)->~T (); 163 } 164 165 template<typename T> 166 inline bool 167 need_finalization_p () 168 { 169 #if GCC_VERSION >= 4003 170 return !__has_trivial_destructor (T); 171 #else 172 return true; 173 #endif 174 } 175 176 template<typename T> 177 inline T * 178 ggc_alloc (ALONE_CXX_MEM_STAT_INFO) 179 { 180 if (need_finalization_p<T> ()) 181 return static_cast<T *> (ggc_internal_alloc (sizeof (T), finalize<T>, 0, 1 182 PASS_MEM_STAT)); 183 else 184 return static_cast<T *> (ggc_internal_alloc (sizeof (T), NULL, 0, 1 185 PASS_MEM_STAT)); 186 } 187 188 template<typename T> 189 inline T * 190 ggc_cleared_alloc (ALONE_CXX_MEM_STAT_INFO) 191 { 192 if (need_finalization_p<T> ()) 193 return static_cast<T *> (ggc_internal_cleared_alloc (sizeof (T), 194 finalize<T>, 0, 1 195 PASS_MEM_STAT)); 196 else 197 return static_cast<T *> (ggc_internal_cleared_alloc (sizeof (T), NULL, 0, 1 198 PASS_MEM_STAT)); 199 } 200 201 template<typename T> 202 inline T * 203 ggc_vec_alloc (size_t c CXX_MEM_STAT_INFO) 204 { 205 if (need_finalization_p<T> ()) 206 return static_cast<T *> (ggc_internal_alloc (c * sizeof (T), finalize<T>, 207 sizeof (T), c PASS_MEM_STAT)); 208 else 209 return static_cast<T *> (ggc_internal_alloc (c * sizeof (T), NULL, 0, 0 210 PASS_MEM_STAT)); 211 } 212 213 template<typename T> 214 inline T * 215 ggc_cleared_vec_alloc (size_t c CXX_MEM_STAT_INFO) 216 { 217 if (need_finalization_p<T> ()) 218 return static_cast<T *> (ggc_internal_cleared_alloc (c * sizeof (T), 219 finalize<T>, 220 sizeof (T), c 221 PASS_MEM_STAT)); 222 else 223 return static_cast<T *> (ggc_internal_cleared_alloc (c * sizeof (T), NULL, 224 0, 0 PASS_MEM_STAT)); 225 } 226 227 inline void * 228 ggc_alloc_atomic (size_t s CXX_MEM_STAT_INFO) 229 { 230 return ggc_internal_alloc (s PASS_MEM_STAT); 231 } 232 233 /* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS. 234 If LENGTH is -1, then CONTENTS is assumed to be a 235 null-terminated string and the memory sized accordingly. */ 236 extern const char *ggc_alloc_string (const char *contents, int length 237 CXX_MEM_STAT_INFO); 238 239 /* Make a copy of S, in GC-able memory. */ 240 #define ggc_strdup(S) ggc_alloc_string ((S), -1 MEM_STAT_INFO) 241 242 /* Invoke the collector. Garbage collection occurs only when this 243 function is called, not during allocations. */ 244 extern void ggc_collect (void); 245 246 /* Assume that all GGC memory is reachable and grow the limits for next collection. */ 247 extern void ggc_grow (void); 248 249 /* Register an additional root table. This can be useful for some 250 plugins. Does nothing if the passed pointer is NULL. */ 251 extern void ggc_register_root_tab (const struct ggc_root_tab *); 252 253 /* Read objects previously saved with gt_pch_save from F. */ 254 extern void gt_pch_restore (FILE *f); 255 256 /* Statistics. */ 257 258 /* Print allocation statistics. */ 259 extern void ggc_print_statistics (void); 260 261 extern void stringpool_statistics (void); 262 263 /* Heuristics. */ 264 extern void init_ggc_heuristics (void); 265 266 #define ggc_alloc_rtvec_sized(NELT) \ 267 (rtvec_def *) ggc_internal_alloc (sizeof (struct rtvec_def) \ 268 + ((NELT) - 1) * sizeof (rtx)) \ 269 270 /* Memory statistics passing versions of some allocators. Too few of them to 271 make gengtype produce them, so just define the needed ones here. */ 272 inline struct rtx_def * 273 ggc_alloc_rtx_def_stat (size_t s CXX_MEM_STAT_INFO) 274 { 275 return (struct rtx_def *) ggc_internal_alloc (s PASS_MEM_STAT); 276 } 277 278 inline union tree_node * 279 ggc_alloc_tree_node_stat (size_t s CXX_MEM_STAT_INFO) 280 { 281 return (union tree_node *) ggc_internal_alloc (s PASS_MEM_STAT); 282 } 283 284 inline union tree_node * 285 ggc_alloc_cleared_tree_node_stat (size_t s CXX_MEM_STAT_INFO) 286 { 287 return (union tree_node *) ggc_internal_cleared_alloc (s PASS_MEM_STAT); 288 } 289 290 inline gimple * 291 ggc_alloc_cleared_gimple_statement_stat (size_t s CXX_MEM_STAT_INFO) 292 { 293 return (gimple *) ggc_internal_cleared_alloc (s PASS_MEM_STAT); 294 } 295 296 inline void 297 gt_ggc_mx (const char *s) 298 { 299 ggc_test_and_set_mark (const_cast<char *> (s)); 300 } 301 302 inline void 303 gt_pch_nx (const char *) 304 { 305 } 306 307 inline void 308 gt_ggc_mx (int) 309 { 310 } 311 312 inline void 313 gt_pch_nx (int) 314 { 315 } 316 317 inline void 318 gt_pch_nx (unsigned int) 319 { 320 } 321 322 #endif 323