1/* Garbage collection for the GNU compiler. 2 3 Copyright (C) 1998-2015 Free Software Foundation, Inc. 4 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify it under 8the terms of the GNU General Public License as published by the Free 9Software Foundation; either version 3, or (at your option) any later 10version. 11 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13WARRANTY; without even the implied warranty of MERCHANTABILITY or 14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15for more details. 16 17You should have received a copy of the GNU General Public License 18along 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#include "statistics.h" 24 25/* Symbols are marked with `ggc' for `gcc gc' so as not to interfere with 26 an external gc library that might be linked in. */ 27 28/* Constants for general use. */ 29extern const char empty_string[]; /* empty string */ 30 31/* Internal functions and data structures used by the GTY 32 machinery, including the generated gt*.[hc] files. */ 33 34#include "gtype-desc.h" 35 36/* One of these applies its third parameter (with cookie in the fourth 37 parameter) to each pointer in the object pointed to by the first 38 parameter, using the second parameter. */ 39typedef void (*gt_note_pointers) (void *, void *, gt_pointer_operator, 40 void *); 41 42/* One of these is called before objects are re-ordered in memory. 43 The first parameter is the original object, the second is the 44 subobject that has had its pointers reordered, the third parameter 45 can compute the new values of a pointer when given the cookie in 46 the fourth parameter. */ 47typedef void (*gt_handle_reorder) (void *, void *, gt_pointer_operator, 48 void *); 49 50/* Used by the gt_pch_n_* routines. Register an object in the hash table. */ 51extern int gt_pch_note_object (void *, void *, gt_note_pointers); 52 53/* Used by the gt_pch_n_* routines. Register that an object has a reorder 54 function. */ 55extern void gt_pch_note_reorder (void *, void *, gt_handle_reorder); 56 57/* generated function to clear caches in gc memory. */ 58extern void gt_clear_caches (); 59 60/* Mark the object in the first parameter and anything it points to. */ 61typedef void (*gt_pointer_walker) (void *); 62 63/* Structures for the easy way to mark roots. 64 In an array, terminated by having base == NULL. */ 65struct ggc_root_tab { 66 void *base; 67 size_t nelt; 68 size_t stride; 69 gt_pointer_walker cb; 70 gt_pointer_walker pchw; 71}; 72#define LAST_GGC_ROOT_TAB { NULL, 0, 0, NULL, NULL } 73/* Pointers to arrays of ggc_root_tab, terminated by NULL. */ 74extern const struct ggc_root_tab * const gt_ggc_rtab[]; 75extern const struct ggc_root_tab * const gt_ggc_deletable_rtab[]; 76extern const struct ggc_root_tab * const gt_pch_scalar_rtab[]; 77 78/* If EXPR is not NULL and previously unmarked, mark it and evaluate 79 to true. Otherwise evaluate to false. */ 80#define ggc_test_and_set_mark(EXPR) \ 81 ((EXPR) != NULL && ((void *) (EXPR)) != (void *) 1 && ! ggc_set_mark (EXPR)) 82 83#define ggc_mark(EXPR) \ 84 do { \ 85 const void *const a__ = (EXPR); \ 86 if (a__ != NULL && a__ != (void *) 1) \ 87 ggc_set_mark (a__); \ 88 } while (0) 89 90/* Actually set the mark on a particular region of memory, but don't 91 follow pointers. This function is called by ggc_mark_*. It 92 returns zero if the object was not previously marked; nonzero if 93 the object was already marked, or if, for any other reason, 94 pointers in this data structure should not be traversed. */ 95extern int ggc_set_mark (const void *); 96 97/* Return 1 if P has been marked, zero otherwise. 98 P must have been allocated by the GC allocator; it mustn't point to 99 static objects, stack variables, or memory allocated with malloc. */ 100extern int ggc_marked_p (const void *); 101 102/* PCH and GGC handling for strings, mostly trivial. */ 103extern void gt_pch_n_S (const void *); 104extern void gt_ggc_m_S (const void *); 105 106/* End of GTY machinery API. */ 107 108/* Initialize the string pool. */ 109extern void init_stringpool (void); 110 111/* Initialize the garbage collector. */ 112extern void init_ggc (void); 113 114/* When true, identifier nodes are considered as GC roots. When 115 false, identifier nodes are treated like any other GC-allocated 116 object, and the identifier hash table is treated as a weak 117 hash. */ 118extern bool ggc_protect_identifiers; 119 120/* Write out all GCed objects to F. */ 121extern void gt_pch_save (FILE *f); 122 123 124/* Allocation. */ 125 126/* The internal primitive. */ 127extern void *ggc_internal_alloc (size_t, void (*)(void *), size_t, 128 size_t CXX_MEM_STAT_INFO) 129 ATTRIBUTE_MALLOC; 130 131 static inline 132 void * 133 ggc_internal_alloc (size_t s CXX_MEM_STAT_INFO) 134{ 135 return ggc_internal_alloc (s, NULL, 0, 1 PASS_MEM_STAT); 136} 137 138extern size_t ggc_round_alloc_size (size_t requested_size); 139 140/* Allocates cleared memory. */ 141extern void *ggc_internal_cleared_alloc (size_t, void (*)(void *), 142 size_t, size_t 143 CXX_MEM_STAT_INFO) ATTRIBUTE_MALLOC; 144 145static inline 146void * 147ggc_internal_cleared_alloc (size_t s CXX_MEM_STAT_INFO) 148{ 149 return ggc_internal_cleared_alloc (s, NULL, 0, 1 PASS_MEM_STAT); 150} 151 152/* Resize a block. */ 153extern void *ggc_realloc (void *, size_t CXX_MEM_STAT_INFO); 154 155/* Free a block. To be used when known for certain it's not reachable. */ 156extern void ggc_free (void *); 157 158extern void dump_ggc_loc_statistics (bool); 159 160/* Reallocator. */ 161#define GGC_RESIZEVEC(T, P, N) \ 162 ((T *) ggc_realloc ((P), (N) * sizeof (T) MEM_STAT_INFO)) 163 164template<typename T> 165void 166finalize (void *p) 167{ 168 static_cast<T *> (p)->~T (); 169} 170 171template<typename T> 172static inline bool 173need_finalization_p () 174{ 175#if GCC_VERSION >= 4003 176 return !__has_trivial_destructor (T); 177#else 178 return true; 179#endif 180} 181 182template<typename T> 183static inline T * 184ggc_alloc (ALONE_CXX_MEM_STAT_INFO) 185{ 186 if (need_finalization_p<T> ()) 187 return static_cast<T *> (ggc_internal_alloc (sizeof (T), finalize<T>, 0, 1 188 PASS_MEM_STAT)); 189 else 190 return static_cast<T *> (ggc_internal_alloc (sizeof (T), NULL, 0, 1 191 PASS_MEM_STAT)); 192} 193 194template<typename T> 195static inline T * 196ggc_cleared_alloc (ALONE_CXX_MEM_STAT_INFO) 197{ 198 if (need_finalization_p<T> ()) 199 return static_cast<T *> (ggc_internal_cleared_alloc (sizeof (T), 200 finalize<T>, 0, 1 201 PASS_MEM_STAT)); 202 else 203 return static_cast<T *> (ggc_internal_cleared_alloc (sizeof (T), NULL, 0, 1 204 PASS_MEM_STAT)); 205} 206 207template<typename T> 208static inline T * 209ggc_vec_alloc (size_t c CXX_MEM_STAT_INFO) 210{ 211 if (need_finalization_p<T> ()) 212 return static_cast<T *> (ggc_internal_alloc (c * sizeof (T), finalize<T>, 213 sizeof (T), c PASS_MEM_STAT)); 214 else 215 return static_cast<T *> (ggc_internal_alloc (c * sizeof (T), NULL, 0, 0 216 PASS_MEM_STAT)); 217} 218 219template<typename T> 220static inline T * 221ggc_cleared_vec_alloc (size_t c CXX_MEM_STAT_INFO) 222{ 223 if (need_finalization_p<T> ()) 224 return static_cast<T *> (ggc_internal_cleared_alloc (c * sizeof (T), 225 finalize<T>, 226 sizeof (T), c 227 PASS_MEM_STAT)); 228 else 229 return static_cast<T *> (ggc_internal_cleared_alloc (c * sizeof (T), NULL, 230 0, 0 PASS_MEM_STAT)); 231} 232 233static inline void * 234ggc_alloc_atomic (size_t s CXX_MEM_STAT_INFO) 235{ 236 return ggc_internal_alloc (s PASS_MEM_STAT); 237} 238 239/* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS. 240 If LENGTH is -1, then CONTENTS is assumed to be a 241 null-terminated string and the memory sized accordingly. */ 242extern const char *ggc_alloc_string (const char *contents, int length 243 CXX_MEM_STAT_INFO); 244 245/* Make a copy of S, in GC-able memory. */ 246#define ggc_strdup(S) ggc_alloc_string ((S), -1 MEM_STAT_INFO) 247 248/* Invoke the collector. Garbage collection occurs only when this 249 function is called, not during allocations. */ 250extern void ggc_collect (void); 251 252/* Assume that all GGC memory is reachable and grow the limits for next collection. */ 253extern void ggc_grow (void); 254 255/* Register an additional root table. This can be useful for some 256 plugins. Does nothing if the passed pointer is NULL. */ 257extern void ggc_register_root_tab (const struct ggc_root_tab *); 258 259/* Read objects previously saved with gt_pch_save from F. */ 260extern void gt_pch_restore (FILE *f); 261 262/* Statistics. */ 263 264/* Print allocation statistics. */ 265extern void ggc_print_statistics (void); 266 267extern void stringpool_statistics (void); 268 269/* Heuristics. */ 270extern void init_ggc_heuristics (void); 271 272#define ggc_alloc_rtvec_sized(NELT) \ 273 (rtvec_def *) ggc_internal_alloc (sizeof (struct rtvec_def) \ 274 + ((NELT) - 1) * sizeof (rtx)) \ 275 276/* Memory statistics passing versions of some allocators. Too few of them to 277 make gengtype produce them, so just define the needed ones here. */ 278static inline struct rtx_def * 279ggc_alloc_rtx_def_stat (size_t s CXX_MEM_STAT_INFO) 280{ 281 return (struct rtx_def *) ggc_internal_alloc (s PASS_MEM_STAT); 282} 283 284static inline union tree_node * 285ggc_alloc_tree_node_stat (size_t s CXX_MEM_STAT_INFO) 286{ 287 return (union tree_node *) ggc_internal_alloc (s PASS_MEM_STAT); 288} 289 290static inline union tree_node * 291ggc_alloc_cleared_tree_node_stat (size_t s CXX_MEM_STAT_INFO) 292{ 293 return (union tree_node *) ggc_internal_cleared_alloc (s PASS_MEM_STAT); 294} 295 296static inline struct gimple_statement_base * 297ggc_alloc_cleared_gimple_statement_stat (size_t s CXX_MEM_STAT_INFO) 298{ 299 return (struct gimple_statement_base *) 300 ggc_internal_cleared_alloc (s PASS_MEM_STAT); 301} 302 303static inline void 304gt_ggc_mx (const char *s) 305{ 306 ggc_test_and_set_mark (const_cast<char *> (s)); 307} 308 309static inline void 310gt_pch_nx (const char *) 311{ 312} 313 314static inline void 315gt_ggc_mx (int) 316{ 317} 318 319static inline void 320gt_pch_nx (int) 321{ 322} 323 324static inline void 325gt_pch_nx (unsigned int) 326{ 327} 328 329#endif 330