gcc/ggc.h

   1 /* Garbage collection for the GNU compiler.
   2
   3    Copyright (C) 1998-2013 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 #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.  */
  29 extern 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.  */
  39 typedef 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.  */
  47 typedef 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.  */
  51 extern int gt_pch_note_object (void *, void *, gt_note_pointers,
  52                                enum gt_types_enum = gt_types_enum_last);
  53
  54 /* Used by the gt_pch_n_* routines.  Register that an object has a reorder
  55    function.  */
  56 extern void gt_pch_note_reorder (void *, void *, gt_handle_reorder);
  57
  58 /* Mark the object in the first parameter and anything it points to.  */
  59 typedef void (*gt_pointer_walker) (void *);
  60
  61 /* Structures for the easy way to mark roots.
  62    In an array, terminated by having base == NULL.  */
  63 struct ggc_root_tab {
  64   void *base;
  65   size_t nelt;
  66   size_t stride;
  67   gt_pointer_walker cb;
  68   gt_pointer_walker pchw;
  69 };
  70 #define LAST_GGC_ROOT_TAB { NULL, 0, 0, NULL, NULL }
  71 /* Pointers to arrays of ggc_root_tab, terminated by NULL.  */
  72 extern const struct ggc_root_tab * const gt_ggc_rtab[];
  73 extern const struct ggc_root_tab * const gt_ggc_deletable_rtab[];
  74 extern const struct ggc_root_tab * const gt_pch_cache_rtab[];
  75 extern const struct ggc_root_tab * const gt_pch_scalar_rtab[];
  76
  77 /* Structure for hash table cache marking.  */
  78 struct htab;
  79 struct ggc_cache_tab {
  80   struct htab * *base;
  81   size_t nelt;
  82   size_t stride;
  83   gt_pointer_walker cb;
  84   gt_pointer_walker pchw;
  85   int (*marked_p) (const void *);
  86 };
  87 #define LAST_GGC_CACHE_TAB { NULL, 0, 0, NULL, NULL, NULL }
  88 /* Pointers to arrays of ggc_cache_tab, terminated by NULL.  */
  89 extern const struct ggc_cache_tab * const gt_ggc_cache_rtab[];
  90
  91 /* If EXPR is not NULL and previously unmarked, mark it and evaluate
  92    to true.  Otherwise evaluate to false.  */
  93 #define ggc_test_and_set_mark(EXPR) \
  94   ((EXPR) != NULL && ((void *) (EXPR)) != (void *) 1 && ! ggc_set_mark (EXPR))
  95
  96 #define ggc_mark(EXPR)                          \
  97   do {                                          \
  98     const void *const a__ = (EXPR);             \
  99     if (a__ != NULL && a__ != (void *) 1)       \
 100       ggc_set_mark (a__);                       \
 101   } while (0)
 102
 103 /* Actually set the mark on a particular region of memory, but don't
 104    follow pointers.  This function is called by ggc_mark_*.  It
 105    returns zero if the object was not previously marked; nonzero if
 106    the object was already marked, or if, for any other reason,
 107    pointers in this data structure should not be traversed.  */
 108 extern int ggc_set_mark (const void *);
 109
 110 /* Return 1 if P has been marked, zero otherwise.
 111    P must have been allocated by the GC allocator; it mustn't point to
 112    static objects, stack variables, or memory allocated with malloc.  */
 113 extern int ggc_marked_p (const void *);
 114
 115 /* PCH and GGC handling for strings, mostly trivial.  */
 116 extern void gt_pch_n_S (const void *);
 117 extern void gt_ggc_m_S (const void *);
 118
 119 /* End of GTY machinery API.  */
 120
 121 struct alloc_zone;
 122
 123 /* Initialize the string pool.  */
 124 extern void init_stringpool (void);
 125
 126 /* Initialize the garbage collector.  */
 127 extern void init_ggc (void);
 128
 129 /* When true, identifier nodes are considered as GC roots.  When
 130    false, identifier nodes are treated like any other GC-allocated
 131    object, and the identifier hash table is treated as a weak
 132    hash.  */
 133 extern bool ggc_protect_identifiers;
 134
 135 /* Write out all GCed objects to F.  */
 136 extern void gt_pch_save (FILE *f);
 137
 138 \f
 139 /* Allocation.  */
 140
 141 /* The internal primitive.  */
 142 extern void *ggc_internal_alloc_stat (size_t MEM_STAT_DECL)
 143   ATTRIBUTE_MALLOC;
 144
 145 extern size_t ggc_round_alloc_size (size_t requested_size);
 146
 147 #define ggc_internal_alloc(s) ggc_internal_alloc_stat (s MEM_STAT_INFO)
 148
 149 /* Allocate an object of the specified type and size.  */
 150 extern void *ggc_alloc_typed_stat (enum gt_types_enum, size_t MEM_STAT_DECL)
 151   ATTRIBUTE_MALLOC;
 152
 153 #define ggc_alloc_typed(s, z) ggc_alloc_typed_stat (s, z MEM_STAT_INFO)
 154
 155 /* Allocates cleared memory.  */
 156 extern void *ggc_internal_cleared_alloc_stat (size_t MEM_STAT_DECL)
 157   ATTRIBUTE_MALLOC;
 158
 159 /* Resize a block.  */
 160 extern void *ggc_realloc_stat (void *, size_t MEM_STAT_DECL);
 161
 162 /* Free a block.  To be used when known for certain it's not reachable.  */
 163 extern void ggc_free (void *);
 164
 165 extern void dump_ggc_loc_statistics (bool);
 166
 167 /* Reallocators.  */
 168 #define GGC_RESIZEVEC(T, P, N) \
 169     ((T *) ggc_realloc_stat ((P), (N) * sizeof (T) MEM_STAT_INFO))
 170
 171 #define GGC_RESIZEVAR(T, P, N)                          \
 172     ((T *) ggc_realloc_stat ((P), (N) MEM_STAT_INFO))
 173
 174 static inline void *
 175 ggc_internal_vec_alloc_stat (size_t s, size_t c MEM_STAT_DECL)
 176 {
 177     return ggc_internal_alloc_stat (c * s PASS_MEM_STAT);
 178 }
 179
 180 static inline void *
 181 ggc_internal_cleared_vec_alloc_stat (size_t s, size_t c MEM_STAT_DECL)
 182 {
 183     return ggc_internal_cleared_alloc_stat (c * s PASS_MEM_STAT);
 184 }
 185
 186 #define ggc_internal_cleared_vec_alloc(s, c) \
 187     (ggc_internal_cleared_vec_alloc_stat ((s), (c) MEM_STAT_INFO))
 188
 189 static inline void *
 190 ggc_alloc_atomic_stat (size_t s MEM_STAT_DECL)
 191 {
 192     return ggc_internal_alloc_stat (s PASS_MEM_STAT);
 193 }
 194
 195 #define ggc_alloc_atomic(S)  (ggc_alloc_atomic_stat ((S) MEM_STAT_INFO))
 196
 197 #define ggc_alloc_cleared_atomic(S)             \
 198     (ggc_internal_cleared_alloc_stat ((S) MEM_STAT_INFO))
 199
 200 extern void *ggc_cleared_alloc_htab_ignore_args (size_t, size_t)
 201   ATTRIBUTE_MALLOC;
 202
 203 extern void *ggc_cleared_alloc_ptr_array_two_args (size_t, size_t)
 204   ATTRIBUTE_MALLOC;
 205
 206 #define htab_create_ggc(SIZE, HASH, EQ, DEL) \
 207   htab_create_typed_alloc (SIZE, HASH, EQ, DEL, \
 208                            ggc_cleared_alloc_htab_ignore_args,          \
 209                            ggc_cleared_alloc_ptr_array_two_args,        \
 210                            ggc_free)
 211
 212 #define splay_tree_new_ggc(COMPARE, ALLOC_TREE, ALLOC_NODE)                  \
 213   splay_tree_new_typed_alloc (COMPARE, NULL, NULL, &ALLOC_TREE, &ALLOC_NODE, \
 214                               &ggc_splay_dont_free, NULL)
 215
 216 extern void *ggc_splay_alloc (enum gt_types_enum, int, void *)
 217   ATTRIBUTE_MALLOC;
 218
 219 extern void ggc_splay_dont_free (void *, void *);
 220
 221 /* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS.
 222    If LENGTH is -1, then CONTENTS is assumed to be a
 223    null-terminated string and the memory sized accordingly.  */
 224 extern const char *ggc_alloc_string_stat (const char *contents, int length
 225                                           MEM_STAT_DECL);
 226
 227 #define ggc_alloc_string(c, l) ggc_alloc_string_stat (c, l MEM_STAT_INFO)
 228
 229 /* Make a copy of S, in GC-able memory.  */
 230 #define ggc_strdup(S) ggc_alloc_string_stat ((S), -1 MEM_STAT_INFO)
 231
 232 /* Invoke the collector.  Garbage collection occurs only when this
 233    function is called, not during allocations.  */
 234 extern void ggc_collect (void);
 235
 236 /* Register an additional root table.  This can be useful for some
 237    plugins.  Does nothing if the passed pointer is NULL. */
 238 extern void ggc_register_root_tab (const struct ggc_root_tab *);
 239
 240 /* Register an additional cache table.  This can be useful for some
 241    plugins.  Does nothing if the passed pointer is NULL. */
 242 extern void ggc_register_cache_tab (const struct ggc_cache_tab *);
 243
 244 /* Read objects previously saved with gt_pch_save from F.  */
 245 extern void gt_pch_restore (FILE *f);
 246 \f
 247 /* Statistics.  */
 248
 249 /* Print allocation statistics.  */
 250 extern void ggc_print_statistics (void);
 251
 252 extern void stringpool_statistics (void);
 253
 254 /* Heuristics.  */
 255 extern void init_ggc_heuristics (void);
 256
 257 /* Zone collection.  */
 258
 259 /* For regular rtl allocations.  */
 260 extern struct alloc_zone rtl_zone;
 261
 262 /* For regular tree allocations.  */
 263 extern struct alloc_zone tree_zone;
 264
 265 /* For IDENTIFIER_NODE allocations.  */
 266 extern struct alloc_zone tree_id_zone;
 267
 268 #define ggc_alloc_rtvec_sized(NELT)                                     \
 269   ggc_alloc_zone_rtvec_def (sizeof (struct rtvec_def)                   \
 270                             + ((NELT) - 1) * sizeof (rtx),              \
 271                             &rtl_zone)
 272
 273 #if defined (GGC_ZONE) && !defined (GENERATOR_FILE)
 274
 275 /* Allocate an object into the specified allocation zone.  */
 276 extern void *ggc_internal_alloc_zone_stat (size_t,
 277                                           struct alloc_zone * MEM_STAT_DECL)
 278   ATTRIBUTE_MALLOC;
 279
 280 extern void *ggc_internal_cleared_alloc_zone_stat (size_t,
 281                                           struct alloc_zone * MEM_STAT_DECL)
 282   ATTRIBUTE_MALLOC;
 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