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