gcc/ggc.h

   1 /* Garbage collection for the GNU compiler.
   2    Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 2, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING.  If not, write to the Free
  18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  19 02111-1307, USA.  */
  20
  21 #include "varray.h"
  22 #include "gtype-desc.h"
  23
  24 /* Symbols are marked with `ggc' for `gcc gc' so as not to interfere with
  25    an external gc library that might be linked in.  */
  26
  27 /* Constants for general use.  */
  28 extern const char empty_string[];       /* empty string */
  29 extern const char digit_vector[];       /* "0" .. "9" */
  30 #define digit_string(d) (digit_vector + ((d) * 2))
  31
  32 /* Manipulate global roots that are needed between calls to gc.  */
  33 extern void ggc_add_root                PARAMS ((void *base, int nelt,
  34                                                  int size, void (*)(void *)));
  35
  36 /* Structures for the easy way to mark roots.
  37    In an array, terminated by having base == NULL.*/
  38 struct ggc_root_tab {
  39   void *base;
  40   size_t nelt;
  41   size_t stride;
  42   void (*cb) PARAMS ((void *));
  43 };
  44 #define LAST_GGC_ROOT_TAB { NULL, 0, 0, NULL }
  45 /* Pointers to arrays of ggc_root_tab, terminated by NULL.  */
  46 extern const struct ggc_root_tab * const gt_ggc_rtab[];
  47 extern const struct ggc_root_tab * const gt_ggc_deletable_rtab[];
  48
  49 /* Structure for hash table cache marking.  */
  50 struct htab;
  51 struct ggc_cache_tab {
  52   struct htab * *base;
  53   size_t nelt;
  54   size_t stride;
  55   void (*cb) PARAMS ((void *));
  56   int (*marked_p) PARAMS ((const void *));
  57 };
  58 #define LAST_GGC_CACHE_TAB { NULL, 0, 0, NULL, NULL }
  59 /* Pointers to arrays of ggc_cache_tab, terminated by NULL.  */
  60 extern const struct ggc_cache_tab * const gt_ggc_cache_rtab[];
  61
  62 extern void ggc_mark_roots              PARAMS ((void));
  63
  64 extern void ggc_mark_rtx_children       PARAMS ((struct rtx_def *));
  65
  66 /* If EXPR is not NULL and previously unmarked, mark it and evaluate
  67    to true.  Otherwise evaluate to false.  */
  68 #define ggc_test_and_set_mark(EXPR) \
  69   ((EXPR) != NULL && ((void *) (EXPR)) != (void *) 1 && ! ggc_set_mark (EXPR))
  70
  71 #define ggc_mark_rtx(EXPR)                      \
  72   do {                                          \
  73     rtx const r__ = (EXPR);                     \
  74     if (ggc_test_and_set_mark (r__))            \
  75       ggc_mark_rtx_children (r__);              \
  76   } while (0)
  77
  78 #define ggc_mark_tree gt_ggc_m_tree_node
  79
  80 #define ggc_mark(EXPR)                          \
  81   do {                                          \
  82     const void *const a__ = (EXPR);             \
  83     if (a__ != NULL && a__ != (void *) 1)       \
  84       ggc_set_mark (a__);                       \
  85   } while (0)
  86
  87 /* A GC implementation must provide these functions.  */
  88
  89 /* Initialize the garbage collector.  */
  90 extern void init_ggc            PARAMS ((void));
  91 extern void init_stringpool     PARAMS ((void));
  92
  93 /* Start a new GGC context.  Memory allocated in previous contexts
  94    will not be collected while the new context is active.  */
  95 extern void ggc_push_context    PARAMS ((void));
  96
  97 /* Finish a GC context.  Any uncollected memory in the new context
  98    will be merged with the old context.  */
  99 extern void ggc_pop_context     PARAMS ((void));
 100
 101 /* Allocation.  */
 102
 103 /* The internal primitive.  */
 104 extern void *ggc_alloc          PARAMS ((size_t));
 105 /* Like ggc_alloc, but allocates cleared memory.  */
 106 extern void *ggc_alloc_cleared  PARAMS ((size_t));
 107 /* Resize a block.  */
 108 extern void *ggc_realloc        PARAMS ((void *, size_t));
 109 /* Like ggc_alloc_cleared, but performs a multiplication.  */
 110 extern void *ggc_calloc         PARAMS ((size_t, size_t));
 111
 112 #define ggc_alloc_rtx(NSLOTS)                                             \
 113   ((struct rtx_def *) ggc_alloc (sizeof (struct rtx_def)                  \
 114                                  + ((NSLOTS) - 1) * sizeof (rtunion)))
 115
 116 #define ggc_alloc_rtvec(NELT)                                             \
 117   ((struct rtvec_def *) ggc_alloc (sizeof (struct rtvec_def)              \
 118                                    + ((NELT) - 1) * sizeof (rtx)))
 119
 120 #define ggc_alloc_tree(LENGTH) ((union tree_node *) ggc_alloc (LENGTH))
 121
 122 #define htab_create_ggc(SIZE, HASH, EQ, DEL) \
 123   htab_create_alloc (SIZE, HASH, EQ, DEL, ggc_calloc, NULL)
 124
 125 /* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS.
 126    If LENGTH is -1, then CONTENTS is assumed to be a
 127    null-terminated string and the memory sized accordingly.  */
 128 extern const char *ggc_alloc_string     PARAMS ((const char *contents,
 129                                                  int length));
 130
 131 /* Make a copy of S, in GC-able memory.  */
 132 #define ggc_strdup(S) ggc_alloc_string((S), -1)
 133
 134 /* Invoke the collector.  Garbage collection occurs only when this
 135    function is called, not during allocations.  */
 136 extern void ggc_collect                 PARAMS ((void));
 137
 138 /* Actually set the mark on a particular region of memory, but don't
 139    follow pointers.  This function is called by ggc_mark_*.  It
 140    returns zero if the object was not previously marked; non-zero if
 141    the object was already marked, or if, for any other reason,
 142    pointers in this data structure should not be traversed.  */
 143 extern int ggc_set_mark                 PARAMS ((const void *));
 144
 145 /* Return 1 if P has been marked, zero otherwise.
 146    P must have been allocated by the GC allocator; it mustn't point to
 147    static objects, stack variables, or memory allocated with malloc.  */
 148 extern int ggc_marked_p                 PARAMS ((const void *));
 149
 150 /* Statistics.  */
 151
 152 /* This structure contains the statistics common to all collectors.
 153    Particular collectors can extend this structure.  */
 154 typedef struct ggc_statistics
 155 {
 156   /* The Ith element is the number of nodes allocated with code I.  */
 157   unsigned num_trees[256];
 158   /* The Ith element is the number of bytes allocated by nodes with
 159      code I.  */
 160   size_t size_trees[256];
 161   /* The Ith element is the number of nodes allocated with code I.  */
 162   unsigned num_rtxs[256];
 163   /* The Ith element is the number of bytes allocated by nodes with
 164      code I.  */
 165   size_t size_rtxs[256];
 166   /* The total size of the tree nodes allocated.  */
 167   size_t total_size_trees;
 168   /* The total size of the RTL nodes allocated.  */
 169   size_t total_size_rtxs;
 170   /* The total number of tree nodes allocated.  */
 171   unsigned total_num_trees;
 172   /* The total number of RTL nodes allocated.  */
 173   unsigned total_num_rtxs;
 174 } ggc_statistics;
 175
 176 /* Return the number of bytes allocated at the indicated address.  */
 177 extern size_t ggc_get_size              PARAMS ((const void *));
 178
 179 /* Used by the various collectors to gather and print statistics that
 180    do not depend on the collector in use.  */
 181 extern void ggc_print_common_statistics PARAMS ((FILE *, ggc_statistics *));
 182
 183 /* Print allocation statistics.  */
 184 extern void ggc_print_statistics        PARAMS ((void));
 185 extern void stringpool_statistics       PARAMS ((void));