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   ATTRIBUTE_MALLOC;
 148
 149 extern size_t ggc_round_alloc_size (size_t requested_size);
 150
 151 #define ggc_internal_alloc(s) ggc_internal_alloc_stat (s MEM_STAT_INFO)
 152
 153 /* Allocate an object of the specified type and size.  */
 154 extern void *ggc_alloc_typed_stat (enum gt_types_enum, size_t MEM_STAT_DECL)
 155   ATTRIBUTE_MALLOC;
 156
 157 #define ggc_alloc_typed(s, z) ggc_alloc_typed_stat (s, z MEM_STAT_INFO)
 158
 159 /* Allocates cleared memory.  */
 160 extern void *ggc_internal_cleared_alloc_stat (size_t MEM_STAT_DECL)
 161   ATTRIBUTE_MALLOC;
 162
 163 /* Resize a block.  */
 164 extern void *ggc_realloc_stat (void *, size_t MEM_STAT_DECL);
 165
 166 /* Free a block.  To be used when known for certain it's not reachable.  */
 167 extern void ggc_free (void *);
 168
 169 extern void dump_ggc_loc_statistics (bool);
 170
 171 /* Reallocators.  */
 172 #define GGC_RESIZEVEC(T, P, N) \
 173     ((T *) ggc_realloc_stat ((P), (N) * sizeof (T) MEM_STAT_INFO))
 174
 175 #define GGC_RESIZEVAR(T, P, N)                          \
 176     ((T *) ggc_realloc_stat ((P), (N) MEM_STAT_INFO))
 177
 178 static inline void *
 179 ggc_internal_vec_alloc_stat (size_t s, size_t c MEM_STAT_DECL)
 180 {
 181     return ggc_internal_alloc_stat (c * s PASS_MEM_STAT);
 182 }
 183
 184 static inline void *
 185 ggc_internal_cleared_vec_alloc_stat (size_t s, size_t c MEM_STAT_DECL)
 186 {
 187     return ggc_internal_cleared_alloc_stat (c * s PASS_MEM_STAT);
 188 }
 189
 190 #define ggc_internal_cleared_vec_alloc(s, c) \
 191     (ggc_internal_cleared_vec_alloc_stat ((s), (c) MEM_STAT_INFO))
 192
 193 static inline void *
 194 ggc_alloc_atomic_stat (size_t s MEM_STAT_DECL)
 195 {
 196     return ggc_internal_alloc_stat (s PASS_MEM_STAT);
 197 }
 198
 199 #define ggc_alloc_atomic(S)  (ggc_alloc_atomic_stat ((S) MEM_STAT_INFO))
 200
 201 #define ggc_alloc_cleared_atomic(S)             \
 202     (ggc_internal_cleared_alloc_stat ((S) MEM_STAT_INFO))
 203
 204 extern void *ggc_cleared_alloc_htab_ignore_args (size_t, size_t)
 205   ATTRIBUTE_MALLOC;
 206
 207 extern void *ggc_cleared_alloc_ptr_array_two_args (size_t, size_t)
 208   ATTRIBUTE_MALLOC;
 209
 210 #define htab_create_ggc(SIZE, HASH, EQ, DEL) \
 211   htab_create_typed_alloc (SIZE, HASH, EQ, DEL, \
 212                            ggc_cleared_alloc_htab_ignore_args,          \
 213                            ggc_cleared_alloc_ptr_array_two_args,        \
 214                            ggc_free)
 215
 216 #define splay_tree_new_ggc(COMPARE, ALLOC_TREE, ALLOC_NODE)                  \
 217   splay_tree_new_typed_alloc (COMPARE, NULL, NULL, &ALLOC_TREE, &ALLOC_NODE, \
 218                               &ggc_splay_dont_free, NULL)
 219
 220 extern void *ggc_splay_alloc (enum gt_types_enum, int, void *)
 221   ATTRIBUTE_MALLOC;
 222
 223 extern void ggc_splay_dont_free (void *, void *);
 224
 225 /* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS.
 226    If LENGTH is -1, then CONTENTS is assumed to be a
 227    null-terminated string and the memory sized accordingly.  */
 228 extern const char *ggc_alloc_string_stat (const char *contents, int length
 229                                           MEM_STAT_DECL);
 230
 231 #define ggc_alloc_string(c, l) ggc_alloc_string_stat (c, l MEM_STAT_INFO)
 232
 233 /* Make a copy of S, in GC-able memory.  */
 234 #define ggc_strdup(S) ggc_alloc_string_stat ((S), -1 MEM_STAT_INFO)
 235
 236 /* Invoke the collector.  Garbage collection occurs only when this
 237    function is called, not during allocations.  */
 238 extern void ggc_collect (void);
 239
 240 /* Register an additional root table.  This can be useful for some
 241    plugins.  Does nothing if the passed pointer is NULL. */
 242 extern void ggc_register_root_tab (const struct ggc_root_tab *);
 243
 244 /* Register an additional cache table.  This can be useful for some
 245    plugins.  Does nothing if the passed pointer is NULL. */
 246 extern void ggc_register_cache_tab (const struct ggc_cache_tab *);
 247
 248 /* Read objects previously saved with gt_pch_save from F.  */
 249 extern void gt_pch_restore (FILE *f);
 250 \f
 251 /* Statistics.  */
 252
 253 /* Print allocation statistics.  */
 254 extern void ggc_print_statistics (void);
 255
 256 extern void stringpool_statistics (void);
 257
 258 /* Heuristics.  */
 259 extern void init_ggc_heuristics (void);
 260
 261 /* Zone collection.  */
 262
 263 /* For regular rtl allocations.  */
 264 extern struct alloc_zone rtl_zone;
 265
 266 /* For regular tree allocations.  */
 267 extern struct alloc_zone tree_zone;
 268
 269 /* For IDENTIFIER_NODE allocations.  */
 270 extern struct alloc_zone tree_id_zone;
 271
 272 #define ggc_alloc_rtvec_sized(NELT)                                     \
 273   ggc_alloc_zone_rtvec_def (sizeof (struct rtvec_def)                   \
 274                             + ((NELT) - 1) * sizeof (rtx),              \
 275                             &rtl_zone)
 276
 277 #if defined (GGC_ZONE) && !defined (GENERATOR_FILE)
 278
 279 /* Allocate an object into the specified allocation zone.  */
 280 extern void *ggc_internal_alloc_zone_stat (size_t,
 281                                           struct alloc_zone * MEM_STAT_DECL)
 282   ATTRIBUTE_MALLOC;
 283
 284 extern void *ggc_internal_cleared_alloc_zone_stat (size_t,
 285                                           struct alloc_zone * MEM_STAT_DECL)
 286   ATTRIBUTE_MALLOC;
 287
 288 static inline void *
 289 ggc_internal_zone_alloc_stat (struct alloc_zone * z, size_t s MEM_STAT_DECL)
 290 {
 291     return ggc_internal_alloc_zone_stat (s, z PASS_MEM_STAT);
 292 }
 293
 294 static inline void *
 295 ggc_internal_zone_cleared_alloc_stat (struct alloc_zone * z, size_t s
 296                                       MEM_STAT_DECL)
 297 {
 298     return ggc_internal_cleared_alloc_zone_stat (s, z PASS_MEM_STAT);
 299 }
 300
 301 static inline void *
 302 ggc_internal_zone_vec_alloc_stat (struct alloc_zone * z, size_t s, size_t n
 303                                   MEM_STAT_DECL)
 304 {
 305     return ggc_internal_alloc_zone_stat (s * n, z PASS_MEM_STAT);
 306 }
 307
 308
 309 #else
 310
 311 static inline void *
 312 ggc_internal_zone_alloc_stat (struct alloc_zone * z ATTRIBUTE_UNUSED,
 313                               size_t s MEM_STAT_DECL)
 314 {
 315     return ggc_internal_alloc_stat (s PASS_MEM_STAT);
 316 }
 317
 318 static inline void *
 319 ggc_internal_zone_cleared_alloc_stat (struct alloc_zone * z ATTRIBUTE_UNUSED,
 320                                       size_t s MEM_STAT_DECL)
 321 {
 322     return ggc_internal_cleared_alloc_stat (s PASS_MEM_STAT);
 323 }
 324
 325 static inline void *
 326 ggc_internal_zone_vec_alloc_stat (struct alloc_zone * z ATTRIBUTE_UNUSED,
 327                                   size_t s, size_t n MEM_STAT_DECL)
 328 {
 329     return ggc_internal_vec_alloc_stat (s, n PASS_MEM_STAT);
 330 }
 331
 332 #endif
 333
 334 /* Memory statistics passing versions of some allocators.  Too few of them to
 335    make gengtype produce them, so just define the needed ones here.  */
 336 static inline struct rtx_def *
 337 ggc_alloc_zone_rtx_def_stat (struct alloc_zone * z, size_t s MEM_STAT_DECL)
 338 {
 339   return (struct rtx_def *) ggc_internal_zone_alloc_stat (z, s PASS_MEM_STAT);
 340 }
 341
 342 static inline union tree_node *
 343 ggc_alloc_zone_tree_node_stat (struct alloc_zone * z, size_t s MEM_STAT_DECL)
 344 {
 345   return (union tree_node *) ggc_internal_zone_alloc_stat (z, s PASS_MEM_STAT);
 346 }
 347
 348 static inline union tree_node *
 349 ggc_alloc_zone_cleared_tree_node_stat (struct alloc_zone * z, size_t s
 350                                        MEM_STAT_DECL)
 351 {
 352   return (union tree_node *)
 353     ggc_internal_zone_cleared_alloc_stat (z, s PASS_MEM_STAT);
 354 }
 355
 356 static inline union gimple_statement_d *
 357 ggc_alloc_cleared_gimple_statement_d_stat (size_t s MEM_STAT_DECL)
 358 {
 359   return (union gimple_statement_d *)
 360     ggc_internal_cleared_alloc_stat (s PASS_MEM_STAT);
 361 }
 362
 363 #endif