gcc/ggc.h

   1 /* Garbage collection for the GNU compiler.
   2
   3    Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007,
   4    2008, 2009, 2010, 2011 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
  32 /* Internal functions and data structures used by the GTY
  33    machinery, including the generated gt*.[hc] files.  */
  34
  35 /* The first parameter is a pointer to a pointer, the second a cookie.  */
  36 typedef void (*gt_pointer_operator) (void *, void *);
  37
  38 #include "gtype-desc.h"
  39
  40 /* One of these applies its third parameter (with cookie in the fourth
  41    parameter) to each pointer in the object pointed to by the first
  42    parameter, using the second parameter.  */
  43 typedef void (*gt_note_pointers) (void *, void *, gt_pointer_operator,
  44                                   void *);
  45
  46 /* One of these is called before objects are re-ordered in memory.
  47    The first parameter is the original object, the second is the
  48    subobject that has had its pointers reordered, the third parameter
  49    can compute the new values of a pointer when given the cookie in
  50    the fourth parameter.  */
  51 typedef void (*gt_handle_reorder) (void *, void *, gt_pointer_operator,
  52                                    void *);
  53
  54 /* Used by the gt_pch_n_* routines.  Register an object in the hash table.  */
  55 extern int gt_pch_note_object (void *, void *, gt_note_pointers,
  56                                enum gt_types_enum);
  57
  58 /* Used by the gt_pch_n_* routines.  Register that an object has a reorder
  59    function.  */
  60 extern void gt_pch_note_reorder (void *, void *, gt_handle_reorder);
  61
  62 /* Mark the object in the first parameter and anything it points to.  */
  63 typedef void (*gt_pointer_walker) (void *);
  64
  65 /* Structures for the easy way to mark roots.
  66    In an array, terminated by having base == NULL.  */
  67 struct ggc_root_tab {
  68   void *base;
  69   size_t nelt;
  70   size_t stride;
  71   gt_pointer_walker cb;
  72   gt_pointer_walker pchw;
  73 };
  74 #define LAST_GGC_ROOT_TAB { NULL, 0, 0, NULL, NULL }
  75 /* Pointers to arrays of ggc_root_tab, terminated by NULL.  */
  76 extern const struct ggc_root_tab * const gt_ggc_rtab[];
  77 extern const struct ggc_root_tab * const gt_ggc_deletable_rtab[];
  78 extern const struct ggc_root_tab * const gt_pch_cache_rtab[];
  79 extern const struct ggc_root_tab * const gt_pch_scalar_rtab[];
  80
  81 /* Structure for hash table cache marking.  */
  82 struct htab;
  83 struct ggc_cache_tab {
  84   struct htab * *base;
  85   size_t nelt;
  86   size_t stride;
  87   gt_pointer_walker cb;
  88   gt_pointer_walker pchw;
  89   int (*marked_p) (const void *);
  90 };
  91 #define LAST_GGC_CACHE_TAB { NULL, 0, 0, NULL, NULL, NULL }
  92 /* Pointers to arrays of ggc_cache_tab, terminated by NULL.  */
  93 extern const struct ggc_cache_tab * const gt_ggc_cache_rtab[];
  94
  95 /* If EXPR is not NULL and previously unmarked, mark it and evaluate
  96    to true.  Otherwise evaluate to false.  */
  97 #define ggc_test_and_set_mark(EXPR) \
  98   ((EXPR) != NULL && ((void *) (EXPR)) != (void *) 1 && ! ggc_set_mark (EXPR))
  99
 100 #define ggc_mark(EXPR)                          \
 101   do {                                          \
 102     const void *const a__ = (EXPR);             \
 103     if (a__ != NULL && a__ != (void *) 1)       \
 104       ggc_set_mark (a__);                       \
 105   } while (0)
 106
 107 /* Actually set the mark on a particular region of memory, but don't
 108    follow pointers.  This function is called by ggc_mark_*.  It
 109    returns zero if the object was not previously marked; nonzero if
 110    the object was already marked, or if, for any other reason,
 111    pointers in this data structure should not be traversed.  */
 112 extern int ggc_set_mark (const void *);
 113
 114 /* Return 1 if P has been marked, zero otherwise.
 115    P must have been allocated by the GC allocator; it mustn't point to
 116    static objects, stack variables, or memory allocated with malloc.  */
 117 extern int ggc_marked_p (const void *);
 118
 119 /* PCH and GGC handling for strings, mostly trivial.  */
 120 extern void gt_pch_n_S (const void *);
 121 extern void gt_ggc_m_S (const void *);
 122
 123 /* End of GTY machinery API.  */
 124
 125 struct alloc_zone;
 126
 127 /* Initialize the string pool.  */
 128 extern void init_stringpool (void);
 129
 130 /* Initialize the garbage collector.  */
 131 extern void init_ggc (void);
 132
 133 /* When true, identifier nodes are considered as GC roots.  When
 134    false, identifier nodes are treated like any other GC-allocated
 135    object, and the identifier hash table is treated as a weak
 136    hash.  */
 137 extern bool ggc_protect_identifiers;
 138
 139 /* Write out all GCed objects to F.  */
 140 extern void gt_pch_save (FILE *f);
 141
 142 \f
 143 /* Allocation.  */
 144
 145 /* The internal primitive.  */
 146 extern void *ggc_internal_alloc_stat (size_t MEM_STAT_DECL);
 147
 148 extern size_t ggc_round_alloc_size (size_t requested_size);
 149
 150 #define ggc_internal_alloc(s) ggc_internal_alloc_stat (s MEM_STAT_INFO)
 151
 152 /* Allocate an object of the specified type and size.  */
 153 extern void *ggc_alloc_typed_stat (enum gt_types_enum, size_t MEM_STAT_DECL);
 154
 155 #define ggc_alloc_typed(s, z) ggc_alloc_typed_stat (s, z MEM_STAT_INFO)
 156
 157 /* Allocates cleared memory.  */
 158 extern void *ggc_internal_cleared_alloc_stat (size_t MEM_STAT_DECL);
 159
 160 /* Resize a block.  */
 161 extern void *ggc_realloc_stat (void *, size_t MEM_STAT_DECL);
 162
 163 /* Free a block.  To be used when known for certain it's not reachable.  */
 164 extern void ggc_free (void *);
 165
 166 extern void ggc_record_overhead (size_t, size_t, void * MEM_STAT_DECL);
 167 extern void ggc_free_overhead (void *);
 168 extern void ggc_prune_overhead_list (void);
 169
 170 extern void dump_ggc_loc_statistics (bool);
 171
 172 /* Reallocators.  */
 173 #define GGC_RESIZEVEC(T, P, N) \
 174     ((T *) ggc_realloc_stat ((P), (N) * sizeof (T) MEM_STAT_INFO))
 175
 176 #define GGC_RESIZEVAR(T, P, N)                          \
 177     ((T *) ggc_realloc_stat ((P), (N) MEM_STAT_INFO))
 178
 179 static inline void *
 180 ggc_internal_vec_alloc_stat (size_t s, size_t c MEM_STAT_DECL)
 181 {
 182     return ggc_internal_alloc_stat (c * s PASS_MEM_STAT);
 183 }
 184
 185 static inline void *
 186 ggc_internal_cleared_vec_alloc_stat (size_t s, size_t c MEM_STAT_DECL)
 187 {
 188     return ggc_internal_cleared_alloc_stat (c * s PASS_MEM_STAT);
 189 }
 190
 191 #define ggc_internal_cleared_vec_alloc(s, c) \
 192     (ggc_internal_cleared_vec_alloc_stat ((s), (c) MEM_STAT_INFO))
 193
 194 static inline void *
 195 ggc_alloc_atomic_stat (size_t s MEM_STAT_DECL)
 196 {
 197     return ggc_internal_alloc_stat (s PASS_MEM_STAT);
 198 }
 199
 200 #define ggc_alloc_atomic(S)  (ggc_alloc_atomic_stat ((S) MEM_STAT_INFO))
 201
 202 #define ggc_alloc_cleared_atomic(S)             \
 203     (ggc_internal_cleared_alloc_stat ((S) MEM_STAT_INFO))
 204
 205 extern void * ggc_cleared_alloc_htab_ignore_args (size_t, size_t);
 206
 207 extern void * ggc_cleared_alloc_ptr_array_two_args (size_t, size_t);
 208
 209 #define htab_create_ggc(SIZE, HASH, EQ, DEL) \
 210   htab_create_typed_alloc (SIZE, HASH, EQ, DEL, \
 211                            ggc_cleared_alloc_htab_ignore_args,          \
 212                            ggc_cleared_alloc_ptr_array_two_args,        \
 213                            ggc_free)
 214
 215 #define splay_tree_new_ggc(COMPARE, ALLOC_TREE, ALLOC_NODE)                  \
 216   splay_tree_new_typed_alloc (COMPARE, NULL, NULL, &ALLOC_TREE, &ALLOC_NODE, \
 217                               &ggc_splay_dont_free, NULL)
 218
 219 extern void *ggc_splay_alloc (enum gt_types_enum, int, void *);
 220
 221 extern void ggc_splay_dont_free (void *, void *);
 222
 223 /* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS.
 224    If LENGTH is -1, then CONTENTS is assumed to be a
 225    null-terminated string and the memory sized accordingly.  */
 226 extern const char *ggc_alloc_string_stat (const char *contents, int length
 227                                           MEM_STAT_DECL);
 228
 229 #define ggc_alloc_string(c, l) ggc_alloc_string_stat (c, l MEM_STAT_INFO)
 230
 231 /* Make a copy of S, in GC-able memory.  */
 232 #define ggc_strdup(S) ggc_alloc_string_stat ((S), -1 MEM_STAT_INFO)
 233
 234 /* Invoke the collector.  Garbage collection occurs only when this
 235    function is called, not during allocations.  */
 236 extern void ggc_collect (void);
 237
 238 /* Register an additional root table.  This can be useful for some
 239    plugins.  Does nothing if the passed pointer is NULL. */
 240 extern void ggc_register_root_tab (const struct ggc_root_tab *);
 241
 242 /* Register an additional cache table.  This can be useful for some
 243    plugins.  Does nothing if the passed pointer is NULL. */
 244 extern void ggc_register_cache_tab (const struct ggc_cache_tab *);
 245
 246 /* Read objects previously saved with gt_pch_save from F.  */
 247 extern void gt_pch_restore (FILE *f);
 248 \f
 249 /* Statistics.  */
 250
 251 /* Print allocation statistics.  */
 252 extern void ggc_print_statistics (void);
 253
 254 extern void stringpool_statistics (void);
 255
 256 /* Heuristics.  */
 257 extern void init_ggc_heuristics (void);
 258
 259 /* Zone collection.  */
 260
 261 /* For regular rtl allocations.  */
 262 extern struct alloc_zone rtl_zone;
 263
 264 /* For regular tree allocations.  */
 265 extern struct alloc_zone tree_zone;
 266
 267 /* For IDENTIFIER_NODE allocations.  */
 268 extern struct alloc_zone tree_id_zone;
 269
 270 #define ggc_alloc_rtvec_sized(NELT)                                     \
 271   ggc_alloc_zone_rtvec_def (sizeof (struct rtvec_def)                   \
 272                             + ((NELT) - 1) * sizeof (rtx),              \
 273                             &rtl_zone)
 274
 275 #if defined (GGC_ZONE) && !defined (GENERATOR_FILE)
 276
 277 /* Allocate an object into the specified allocation zone.  */
 278 extern void *ggc_internal_alloc_zone_stat (size_t,
 279                                           struct alloc_zone * MEM_STAT_DECL);
 280
 281 extern void *ggc_internal_cleared_alloc_zone_stat (size_t,
 282                                           struct alloc_zone * MEM_STAT_DECL);
 283
 284 static inline void *
 285 ggc_internal_zone_alloc_stat (struct alloc_zone * z, size_t s MEM_STAT_DECL)
 286 {
 287     return ggc_internal_alloc_zone_stat (s, z PASS_MEM_STAT);
 288 }
 289
 290 static inline void *
 291 ggc_internal_zone_cleared_alloc_stat (struct alloc_zone * z, size_t s
 292                                       MEM_STAT_DECL)
 293 {
 294     return ggc_internal_cleared_alloc_zone_stat (s, z PASS_MEM_STAT);
 295 }
 296
 297 static inline void *
 298 ggc_internal_zone_vec_alloc_stat (struct alloc_zone * z, size_t s, size_t n
 299                                   MEM_STAT_DECL)
 300 {
 301     return ggc_internal_alloc_zone_stat (s * n, z PASS_MEM_STAT);
 302 }
 303
 304
 305 #else
 306
 307 static inline void *
 308 ggc_internal_zone_alloc_stat (struct alloc_zone * z ATTRIBUTE_UNUSED,
 309                               size_t s MEM_STAT_DECL)
 310 {
 311     return ggc_internal_alloc_stat (s PASS_MEM_STAT);
 312 }
 313
 314 static inline void *
 315 ggc_internal_zone_cleared_alloc_stat (struct alloc_zone * z ATTRIBUTE_UNUSED,
 316                                       size_t s MEM_STAT_DECL)
 317 {
 318     return ggc_internal_cleared_alloc_stat (s PASS_MEM_STAT);
 319 }
 320
 321 static inline void *
 322 ggc_internal_zone_vec_alloc_stat (struct alloc_zone * z ATTRIBUTE_UNUSED,
 323                                   size_t s, size_t n MEM_STAT_DECL)
 324 {
 325     return ggc_internal_vec_alloc_stat (s, n PASS_MEM_STAT);
 326 }
 327
 328 #endif
 329
 330 /* Memory statistics passing versions of some allocators.  Too few of them to
 331    make gengtype produce them, so just define the needed ones here.  */
 332 static inline struct rtx_def *
 333 ggc_alloc_zone_rtx_def_stat (struct alloc_zone * z, size_t s MEM_STAT_DECL)
 334 {
 335   return (struct rtx_def *) ggc_internal_zone_alloc_stat (z, s PASS_MEM_STAT);
 336 }
 337
 338 static inline union tree_node *
 339 ggc_alloc_zone_tree_node_stat (struct alloc_zone * z, size_t s MEM_STAT_DECL)
 340 {
 341   return (union tree_node *) ggc_internal_zone_alloc_stat (z, s PASS_MEM_STAT);
 342 }
 343
 344 static inline union tree_node *
 345 ggc_alloc_zone_cleared_tree_node_stat (struct alloc_zone * z, size_t s
 346                                        MEM_STAT_DECL)
 347 {
 348   return (union tree_node *)
 349     ggc_internal_zone_cleared_alloc_stat (z, s PASS_MEM_STAT);
 350 }
 351
 352 static inline union gimple_statement_d *
 353 ggc_alloc_cleared_gimple_statement_d_stat (size_t s MEM_STAT_DECL)
 354 {
 355   return (union gimple_statement_d *)
 356     ggc_internal_cleared_alloc_stat (s PASS_MEM_STAT);
 357 }
 358
 359 #endif