gcc/ggc.h

   1 /* Garbage collection for the GNU compiler.
   2
   3    Copyright (C) 1998-2014 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
  53 /* Used by the gt_pch_n_* routines.  Register that an object has a reorder
  54    function.  */
  55 extern void gt_pch_note_reorder (void *, void *, gt_handle_reorder);
  56
  57 /* Mark the object in the first parameter and anything it points to.  */
  58 typedef void (*gt_pointer_walker) (void *);
  59
  60 /* Structures for the easy way to mark roots.
  61    In an array, terminated by having base == NULL.  */
  62 struct ggc_root_tab {
  63   void *base;
  64   size_t nelt;
  65   size_t stride;
  66   gt_pointer_walker cb;
  67   gt_pointer_walker pchw;
  68 };
  69 #define LAST_GGC_ROOT_TAB { NULL, 0, 0, NULL, NULL }
  70 /* Pointers to arrays of ggc_root_tab, terminated by NULL.  */
  71 extern const struct ggc_root_tab * const gt_ggc_rtab[];
  72 extern const struct ggc_root_tab * const gt_ggc_deletable_rtab[];
  73 extern const struct ggc_root_tab * const gt_pch_cache_rtab[];
  74 extern const struct ggc_root_tab * const gt_pch_scalar_rtab[];
  75
  76 /* Structure for hash table cache marking.  */
  77 struct htab;
  78 struct ggc_cache_tab {
  79   struct htab * *base;
  80   size_t nelt;
  81   size_t stride;
  82   gt_pointer_walker cb;
  83   gt_pointer_walker pchw;
  84   int (*marked_p) (const void *);
  85 };
  86 #define LAST_GGC_CACHE_TAB { NULL, 0, 0, NULL, NULL, NULL }
  87 /* Pointers to arrays of ggc_cache_tab, terminated by NULL.  */
  88 extern const struct ggc_cache_tab * const gt_ggc_cache_rtab[];
  89
  90 /* If EXPR is not NULL and previously unmarked, mark it and evaluate
  91    to true.  Otherwise evaluate to false.  */
  92 #define ggc_test_and_set_mark(EXPR) \
  93   ((EXPR) != NULL && ((void *) (EXPR)) != (void *) 1 && ! ggc_set_mark (EXPR))
  94
  95 #define ggc_mark(EXPR)                          \
  96   do {                                          \
  97     const void *const a__ = (EXPR);             \
  98     if (a__ != NULL && a__ != (void *) 1)       \
  99       ggc_set_mark (a__);                       \
 100   } while (0)
 101
 102 /* Actually set the mark on a particular region of memory, but don't
 103    follow pointers.  This function is called by ggc_mark_*.  It
 104    returns zero if the object was not previously marked; nonzero if
 105    the object was already marked, or if, for any other reason,
 106    pointers in this data structure should not be traversed.  */
 107 extern int ggc_set_mark (const void *);
 108
 109 /* Return 1 if P has been marked, zero otherwise.
 110    P must have been allocated by the GC allocator; it mustn't point to
 111    static objects, stack variables, or memory allocated with malloc.  */
 112 extern int ggc_marked_p (const void *);
 113
 114 /* PCH and GGC handling for strings, mostly trivial.  */
 115 extern void gt_pch_n_S (const void *);
 116 extern void gt_ggc_m_S (const void *);
 117
 118 /* End of GTY machinery API.  */
 119
 120 /* Initialize the string pool.  */
 121 extern void init_stringpool (void);
 122
 123 /* Initialize the garbage collector.  */
 124 extern void init_ggc (void);
 125
 126 /* When true, identifier nodes are considered as GC roots.  When
 127    false, identifier nodes are treated like any other GC-allocated
 128    object, and the identifier hash table is treated as a weak
 129    hash.  */
 130 extern bool ggc_protect_identifiers;
 131
 132 /* Write out all GCed objects to F.  */
 133 extern void gt_pch_save (FILE *f);
 134
 135 \f
 136 /* Allocation.  */
 137
 138 /* The internal primitive.  */
 139 extern void *ggc_internal_alloc (size_t CXX_MEM_STAT_INFO) ATTRIBUTE_MALLOC;
 140
 141 extern size_t ggc_round_alloc_size (size_t requested_size);
 142
 143 /* Allocates cleared memory.  */
 144 extern void *ggc_internal_cleared_alloc (size_t CXX_MEM_STAT_INFO)
 145   ATTRIBUTE_MALLOC;
 146
 147 /* Resize a block.  */
 148 extern void *ggc_realloc (void *, size_t CXX_MEM_STAT_INFO);
 149
 150 /* Free a block.  To be used when known for certain it's not reachable.  */
 151 extern void ggc_free (void *);
 152
 153 extern void dump_ggc_loc_statistics (bool);
 154
 155 /* Reallocator.  */
 156 #define GGC_RESIZEVEC(T, P, N) \
 157     ((T *) ggc_realloc ((P), (N) * sizeof (T) MEM_STAT_INFO))
 158
 159 template<typename T>
 160 static inline T *
 161 ggc_alloc (ALONE_CXX_MEM_STAT_INFO)
 162 {
 163   return static_cast<T *> (ggc_internal_alloc (sizeof (T) PASS_MEM_STAT));
 164 }
 165
 166 template<typename T>
 167 static inline T *
 168 ggc_cleared_alloc (ALONE_CXX_MEM_STAT_INFO)
 169 {
 170   return static_cast<T *> (ggc_internal_cleared_alloc (sizeof (T)
 171                                                        PASS_MEM_STAT));
 172 }
 173
 174 template<typename T>
 175 static inline T *
 176 ggc_vec_alloc (size_t c CXX_MEM_STAT_INFO)
 177 {
 178     return static_cast<T *> (ggc_internal_alloc (c * sizeof (T)
 179                                                  PASS_MEM_STAT));
 180 }
 181
 182 template<typename T>
 183 static inline T *
 184 ggc_cleared_vec_alloc (size_t c CXX_MEM_STAT_INFO)
 185 {
 186     return static_cast<T *> (ggc_internal_cleared_alloc (c * sizeof (T)
 187                                                          PASS_MEM_STAT));
 188 }
 189
 190 static inline void *
 191 ggc_alloc_atomic (size_t s CXX_MEM_STAT_INFO)
 192 {
 193     return ggc_internal_alloc (s PASS_MEM_STAT);
 194 }
 195
 196 extern void *ggc_cleared_alloc_htab_ignore_args (size_t, size_t)
 197   ATTRIBUTE_MALLOC;
 198
 199 extern void *ggc_cleared_alloc_ptr_array_two_args (size_t, size_t)
 200   ATTRIBUTE_MALLOC;
 201
 202 #define htab_create_ggc(SIZE, HASH, EQ, DEL) \
 203   htab_create_typed_alloc (SIZE, HASH, EQ, DEL, \
 204                            ggc_cleared_alloc_htab_ignore_args,          \
 205                            ggc_cleared_alloc_ptr_array_two_args,        \
 206                            ggc_free)
 207
 208 #define splay_tree_new_ggc(COMPARE, ALLOC_TREE, ALLOC_NODE)                  \
 209   splay_tree_new_typed_alloc (COMPARE, NULL, NULL, &ALLOC_TREE, &ALLOC_NODE, \
 210                               &ggc_splay_dont_free, NULL)
 211
 212 extern void *ggc_splay_alloc (int, void *)
 213   ATTRIBUTE_MALLOC;
 214
 215 extern void ggc_splay_dont_free (void *, void *);
 216
 217 /* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS.
 218    If LENGTH is -1, then CONTENTS is assumed to be a
 219    null-terminated string and the memory sized accordingly.  */
 220 extern const char *ggc_alloc_string (const char *contents, int length
 221                                      CXX_MEM_STAT_INFO);
 222
 223 /* Make a copy of S, in GC-able memory.  */
 224 #define ggc_strdup(S) ggc_alloc_string ((S), -1 MEM_STAT_INFO)
 225
 226 /* Invoke the collector.  Garbage collection occurs only when this
 227    function is called, not during allocations.  */
 228 extern void ggc_collect (void);
 229
 230 /* Register an additional root table.  This can be useful for some
 231    plugins.  Does nothing if the passed pointer is NULL. */
 232 extern void ggc_register_root_tab (const struct ggc_root_tab *);
 233
 234 /* Register an additional cache table.  This can be useful for some
 235    plugins.  Does nothing if the passed pointer is NULL. */
 236 extern void ggc_register_cache_tab (const struct ggc_cache_tab *);
 237
 238 /* Read objects previously saved with gt_pch_save from F.  */
 239 extern void gt_pch_restore (FILE *f);
 240 \f
 241 /* Statistics.  */
 242
 243 /* Print allocation statistics.  */
 244 extern void ggc_print_statistics (void);
 245
 246 extern void stringpool_statistics (void);
 247
 248 /* Heuristics.  */
 249 extern void init_ggc_heuristics (void);
 250
 251 #define ggc_alloc_rtvec_sized(NELT)                             \
 252   (rtvec_def *) ggc_internal_alloc (sizeof (struct rtvec_def)           \
 253                        + ((NELT) - 1) * sizeof (rtx))           \
 254
 255 /* Memory statistics passing versions of some allocators.  Too few of them to
 256    make gengtype produce them, so just define the needed ones here.  */
 257 static inline struct rtx_def *
 258 ggc_alloc_rtx_def_stat (size_t s CXX_MEM_STAT_INFO)
 259 {
 260   return (struct rtx_def *) ggc_internal_alloc (s PASS_MEM_STAT);
 261 }
 262
 263 static inline union tree_node *
 264 ggc_alloc_tree_node_stat (size_t s CXX_MEM_STAT_INFO)
 265 {
 266   return (union tree_node *) ggc_internal_alloc (s PASS_MEM_STAT);
 267 }
 268
 269 static inline union tree_node *
 270 ggc_alloc_cleared_tree_node_stat (size_t s CXX_MEM_STAT_INFO)
 271 {
 272   return (union tree_node *) ggc_internal_cleared_alloc (s PASS_MEM_STAT);
 273 }
 274
 275 static inline struct gimple_statement_base *
 276 ggc_alloc_cleared_gimple_statement_stat (size_t s CXX_MEM_STAT_INFO)
 277 {
 278   return (struct gimple_statement_base *)
 279     ggc_internal_cleared_alloc (s PASS_MEM_STAT);
 280 }
 281
 282 static inline struct simd_clone *
 283 ggc_alloc_cleared_simd_clone_stat (size_t s CXX_MEM_STAT_INFO)
 284 {
 285   return (struct simd_clone *)
 286     ggc_internal_cleared_alloc (s PASS_MEM_STAT);
 287 }
 288
 289 #endif