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 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 #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
 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
 158 /* Resize a block.  */
 159 extern void *ggc_realloc_stat (void *, size_t MEM_STAT_DECL);
 160
 161 /* Free a block.  To be used when known for certain it's not reachable.  */
 162 extern void ggc_free (void *);
 163
 164 extern void ggc_record_overhead (size_t, size_t, void * MEM_STAT_DECL);
 165 extern void ggc_free_overhead (void *);
 166 extern void ggc_prune_overhead_list (void);
 167
 168 extern void dump_ggc_loc_statistics (bool);
 169
 170 /* Reallocators.  */
 171 #define GGC_RESIZEVEC(T, P, N) \
 172     ((T *) ggc_realloc_stat ((P), (N) * sizeof (T) MEM_STAT_INFO))
 173
 174 #define GGC_RESIZEVAR(T, P, N)                          \
 175     ((T *) ggc_realloc_stat ((P), (N) MEM_STAT_INFO))
 176
 177 static inline void *
 178 ggc_internal_vec_alloc_stat (size_t s, size_t c MEM_STAT_DECL)
 179 {
 180     return ggc_internal_alloc_stat (c * s PASS_MEM_STAT);
 181 }
 182
 183 static inline void *
 184 ggc_internal_cleared_vec_alloc_stat (size_t s, size_t c MEM_STAT_DECL)
 185 {
 186     return ggc_internal_cleared_alloc_stat (c * s PASS_MEM_STAT);
 187 }
 188
 189 #define ggc_internal_cleared_vec_alloc(s, c) \
 190     (ggc_internal_cleared_vec_alloc_stat ((s), (c) MEM_STAT_INFO))
 191
 192 static inline void *
 193 ggc_alloc_atomic_stat (size_t s MEM_STAT_DECL)
 194 {
 195     return ggc_internal_alloc_stat (s PASS_MEM_STAT);
 196 }
 197
 198 #define ggc_alloc_atomic(S)  (ggc_alloc_atomic_stat ((S) MEM_STAT_INFO))
 199
 200 #define ggc_alloc_cleared_atomic(S)             \
 201     (ggc_internal_cleared_alloc_stat ((S) MEM_STAT_INFO))
 202
 203 extern void * ggc_cleared_alloc_htab_ignore_args (size_t, size_t);
 204
 205 extern void * ggc_cleared_alloc_ptr_array_two_args (size_t, size_t);
 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
 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_vec_rtvec_def (sizeof (rtx),                        \
 270                                    sizeof (struct rtvec_def) + ((NELT) - 1), \
 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
 279 extern void *ggc_internal_cleared_alloc_zone_stat (size_t,
 280                                           struct alloc_zone * MEM_STAT_DECL);
 281
 282 static inline void *
 283 ggc_internal_zone_alloc_stat (struct alloc_zone * z, size_t s MEM_STAT_DECL)
 284 {
 285     return ggc_internal_alloc_zone_stat (s, z PASS_MEM_STAT);
 286 }
 287
 288 static inline void *
 289 ggc_internal_zone_cleared_alloc_stat (struct alloc_zone * z, size_t s
 290                                       MEM_STAT_DECL)
 291 {
 292     return ggc_internal_cleared_alloc_zone_stat (s, z PASS_MEM_STAT);
 293 }
 294
 295 static inline void *
 296 ggc_internal_zone_vec_alloc_stat (struct alloc_zone * z, size_t s, size_t n
 297                                   MEM_STAT_DECL)
 298 {
 299     return ggc_internal_alloc_zone_stat (s * n, z PASS_MEM_STAT);
 300 }
 301
 302
 303 #else
 304
 305 static inline void *
 306 ggc_internal_zone_alloc_stat (struct alloc_zone * z ATTRIBUTE_UNUSED,
 307                               size_t s MEM_STAT_DECL)
 308 {
 309     return ggc_internal_alloc_stat (s PASS_MEM_STAT);
 310 }
 311
 312 static inline void *
 313 ggc_internal_zone_cleared_alloc_stat (struct alloc_zone * z ATTRIBUTE_UNUSED,
 314                                       size_t s MEM_STAT_DECL)
 315 {
 316     return ggc_internal_cleared_alloc_stat (s PASS_MEM_STAT);
 317 }
 318
 319 static inline void *
 320 ggc_internal_zone_vec_alloc_stat (struct alloc_zone * z ATTRIBUTE_UNUSED,
 321                                   size_t s, size_t n MEM_STAT_DECL)
 322 {
 323     return ggc_internal_vec_alloc_stat (s, n PASS_MEM_STAT);
 324 }
 325
 326 #endif
 327
 328 /* Memory statistics passing versions of some allocators.  Too few of them to
 329    make gengtype produce them, so just define the needed ones here.  */
 330 static inline struct rtx_def *
 331 ggc_alloc_zone_rtx_def_stat (struct alloc_zone * z, size_t s MEM_STAT_DECL)
 332 {
 333   return (struct rtx_def *) ggc_internal_zone_alloc_stat (z, s PASS_MEM_STAT);
 334 }
 335
 336 static inline union tree_node *
 337 ggc_alloc_zone_tree_node_stat (struct alloc_zone * z, size_t s MEM_STAT_DECL)
 338 {
 339   return (union tree_node *) ggc_internal_zone_alloc_stat (z, s PASS_MEM_STAT);
 340 }
 341
 342 static inline union tree_node *
 343 ggc_alloc_zone_cleared_tree_node_stat (struct alloc_zone * z, size_t s
 344                                        MEM_STAT_DECL)
 345 {
 346   return (union tree_node *)
 347     ggc_internal_zone_cleared_alloc_stat (z, s PASS_MEM_STAT);
 348 }
 349
 350 static inline union gimple_statement_d *
 351 ggc_alloc_cleared_gimple_statement_d_stat (size_t s MEM_STAT_DECL)
 352 {
 353   return (union gimple_statement_d *)
 354     ggc_internal_cleared_alloc_stat (s PASS_MEM_STAT);
 355 }
 356
 357 #endif