1/* Garbage collection for the GNU compiler. 2 3 Copyright (C) 1998-2020 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 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. */ 35typedef 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. */ 43typedef 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. */ 47extern 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. */ 51extern void gt_pch_note_reorder (void *, void *, gt_handle_reorder); 52 53/* generated function to clear caches in gc memory. */ 54extern void gt_clear_caches (); 55 56/* Mark the object in the first parameter and anything it points to. */ 57typedef void (*gt_pointer_walker) (void *); 58 59/* Structures for the easy way to mark roots. 60 In an array, terminated by having base == NULL. */ 61struct 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. */ 70extern const struct ggc_root_tab * const gt_ggc_rtab[]; 71extern const struct ggc_root_tab * const gt_ggc_deletable_rtab[]; 72extern 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. */ 91extern 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. */ 96extern int ggc_marked_p (const void *); 97 98/* PCH and GGC handling for strings, mostly trivial. */ 99extern void gt_pch_n_S (const void *); 100extern void gt_ggc_m_S (const void *); 101 102/* End of GTY machinery API. */ 103 104/* Initialize the string pool. */ 105extern void init_stringpool (void); 106 107/* Initialize the garbage collector. */ 108extern 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. */ 114extern bool ggc_protect_identifiers; 115 116/* Write out all GCed objects to F. */ 117extern void gt_pch_save (FILE *f); 118 119 120/* Allocation. */ 121 122/* The internal primitive. */ 123extern void *ggc_internal_alloc (size_t, void (*)(void *), size_t, 124 size_t CXX_MEM_STAT_INFO) 125 ATTRIBUTE_MALLOC; 126 127inline void * 128ggc_internal_alloc (size_t s CXX_MEM_STAT_INFO) 129{ 130 return ggc_internal_alloc (s, NULL, 0, 1 PASS_MEM_STAT); 131} 132 133extern size_t ggc_round_alloc_size (size_t requested_size); 134 135/* Allocates cleared memory. */ 136extern void *ggc_internal_cleared_alloc (size_t, void (*)(void *), 137 size_t, size_t 138 CXX_MEM_STAT_INFO) ATTRIBUTE_MALLOC; 139 140inline void * 141ggc_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. */ 147extern 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. */ 150extern void ggc_free (void *); 151 152extern void dump_ggc_loc_statistics (); 153 154/* Reallocator. */ 155#define GGC_RESIZEVEC(T, P, N) \ 156 ((T *) ggc_realloc ((P), (N) * sizeof (T) MEM_STAT_INFO)) 157 158template<typename T> 159void 160finalize (void *p) 161{ 162 static_cast<T *> (p)->~T (); 163} 164 165template<typename T> 166inline bool 167need_finalization_p () 168{ 169#if GCC_VERSION >= 4003 170 return !__has_trivial_destructor (T); 171#else 172 return true; 173#endif 174} 175 176template<typename T> 177inline T * 178ggc_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/* GGC allocation function that does not call finalizer for type 189 that have need_finalization_p equal to true. User is responsible 190 for calling of the destructor. */ 191 192template<typename T> 193inline T * 194ggc_alloc_no_dtor (ALONE_CXX_MEM_STAT_INFO) 195{ 196 return static_cast<T *> (ggc_internal_alloc (sizeof (T), NULL, 0, 1 197 PASS_MEM_STAT)); 198} 199 200template<typename T> 201inline T * 202ggc_cleared_alloc (ALONE_CXX_MEM_STAT_INFO) 203{ 204 if (need_finalization_p<T> ()) 205 return static_cast<T *> (ggc_internal_cleared_alloc (sizeof (T), 206 finalize<T>, 0, 1 207 PASS_MEM_STAT)); 208 else 209 return static_cast<T *> (ggc_internal_cleared_alloc (sizeof (T), NULL, 0, 1 210 PASS_MEM_STAT)); 211} 212 213template<typename T> 214inline T * 215ggc_vec_alloc (size_t c CXX_MEM_STAT_INFO) 216{ 217 if (need_finalization_p<T> ()) 218 return static_cast<T *> (ggc_internal_alloc (c * sizeof (T), finalize<T>, 219 sizeof (T), c PASS_MEM_STAT)); 220 else 221 return static_cast<T *> (ggc_internal_alloc (c * sizeof (T), NULL, 0, 0 222 PASS_MEM_STAT)); 223} 224 225template<typename T> 226inline T * 227ggc_cleared_vec_alloc (size_t c CXX_MEM_STAT_INFO) 228{ 229 if (need_finalization_p<T> ()) 230 return static_cast<T *> (ggc_internal_cleared_alloc (c * sizeof (T), 231 finalize<T>, 232 sizeof (T), c 233 PASS_MEM_STAT)); 234 else 235 return static_cast<T *> (ggc_internal_cleared_alloc (c * sizeof (T), NULL, 236 0, 0 PASS_MEM_STAT)); 237} 238 239inline void * 240ggc_alloc_atomic (size_t s CXX_MEM_STAT_INFO) 241{ 242 return ggc_internal_alloc (s PASS_MEM_STAT); 243} 244 245/* Call destructor and free the garbage collected memory. */ 246 247template <typename T> 248inline void 249ggc_delete (T *ptr) 250{ 251 ptr->~T (); 252 ggc_free (ptr); 253} 254 255/* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS. 256 If LENGTH is -1, then CONTENTS is assumed to be a 257 null-terminated string and the memory sized accordingly. */ 258extern const char *ggc_alloc_string (const char *contents, int length 259 CXX_MEM_STAT_INFO); 260 261/* Make a copy of S, in GC-able memory. */ 262#define ggc_strdup(S) ggc_alloc_string ((S), -1 MEM_STAT_INFO) 263 264/* Invoke the collector. Garbage collection occurs only when this 265 function is called, not during allocations. */ 266extern void ggc_collect (void); 267 268/* Return unused memory pages to the system. */ 269extern void ggc_trim (void); 270 271/* Assume that all GGC memory is reachable and grow the limits for next collection. */ 272extern void ggc_grow (void); 273 274/* Register an additional root table. This can be useful for some 275 plugins. Does nothing if the passed pointer is NULL. */ 276extern void ggc_register_root_tab (const struct ggc_root_tab *); 277 278/* Read objects previously saved with gt_pch_save from F. */ 279extern void gt_pch_restore (FILE *f); 280 281/* Statistics. */ 282 283/* Print allocation statistics. */ 284extern void ggc_print_statistics (void); 285 286extern void stringpool_statistics (void); 287 288/* Heuristics. */ 289extern void init_ggc_heuristics (void); 290 291/* Report current heap memory use to stderr. */ 292extern void report_heap_memory_use (void); 293 294#define ggc_alloc_rtvec_sized(NELT) \ 295 (rtvec_def *) ggc_internal_alloc (sizeof (struct rtvec_def) \ 296 + ((NELT) - 1) * sizeof (rtx)) \ 297 298/* Memory statistics passing versions of some allocators. Too few of them to 299 make gengtype produce them, so just define the needed ones here. */ 300inline struct rtx_def * 301ggc_alloc_rtx_def_stat (size_t s CXX_MEM_STAT_INFO) 302{ 303 return (struct rtx_def *) ggc_internal_alloc (s PASS_MEM_STAT); 304} 305 306inline union tree_node * 307ggc_alloc_tree_node_stat (size_t s CXX_MEM_STAT_INFO) 308{ 309 return (union tree_node *) ggc_internal_alloc (s PASS_MEM_STAT); 310} 311 312inline union tree_node * 313ggc_alloc_cleared_tree_node_stat (size_t s CXX_MEM_STAT_INFO) 314{ 315 return (union tree_node *) ggc_internal_cleared_alloc (s PASS_MEM_STAT); 316} 317 318inline gimple * 319ggc_alloc_cleared_gimple_statement_stat (size_t s CXX_MEM_STAT_INFO) 320{ 321 return (gimple *) ggc_internal_cleared_alloc (s PASS_MEM_STAT); 322} 323 324inline void 325gt_ggc_mx (const char *s) 326{ 327 ggc_test_and_set_mark (const_cast<char *> (s)); 328} 329 330inline void 331gt_pch_nx (const char *) 332{ 333} 334 335inline void 336gt_ggc_mx (int) 337{ 338} 339 340inline void 341gt_pch_nx (int) 342{ 343} 344 345inline void 346gt_pch_nx (unsigned int) 347{ 348} 349 350#endif 351