gcc/ggc.h

   1 /* Garbage collection for the GNU compiler.
   2    Copyright (C) 1998, 1999, 2000, 2001, 2002 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  33    THIS ROUTINE IS OBSOLETE, do not use it for new code.  */
  34 extern void ggc_add_root                PARAMS ((void *base, int nelt,
  35                                                  int size, void (*)(void *)));
  36
  37 /* Structures for the easy way to mark roots.
  38    In an array, terminated by having base == NULL.*/
  39 struct ggc_root_tab {
  40   void *base;
  41   size_t nelt;
  42   size_t stride;
  43   void (*cb) PARAMS ((void *));
  44 };
  45 #define LAST_GGC_ROOT_TAB { NULL, 0, 0, NULL }
  46 /* Pointers to arrays of ggc_root_tab, terminated by NULL.  */
  47 extern const struct ggc_root_tab * const gt_ggc_rtab[];
  48 extern const struct ggc_root_tab * const gt_ggc_deletable_rtab[];
  49
  50 /* Structure for hash table cache marking.  */
  51 struct htab;
  52 struct ggc_cache_tab {
  53   struct htab * *base;
  54   size_t nelt;
  55   size_t stride;
  56   void (*cb) PARAMS ((void *));
  57   int (*marked_p) PARAMS ((const void *));
  58 };
  59 #define LAST_GGC_CACHE_TAB { NULL, 0, 0, NULL, NULL }
  60 /* Pointers to arrays of ggc_cache_tab, terminated by NULL.  */
  61 extern const struct ggc_cache_tab * const gt_ggc_cache_rtab[];
  62
  63 extern void ggc_mark_roots              PARAMS ((void));
  64
  65 /* If EXPR is not NULL and previously unmarked, mark it and evaluate
  66    to true.  Otherwise evaluate to false.  */
  67 #define ggc_test_and_set_mark(EXPR) \
  68   ((EXPR) != NULL && ((void *) (EXPR)) != (void *) 1 && ! ggc_set_mark (EXPR))
  69
  70 #define ggc_mark_rtx gt_ggc_m_7rtx_def
  71 #define ggc_mark_tree gt_ggc_m_9tree_node
  72
  73 #define ggc_mark(EXPR)                          \
  74   do {                                          \
  75     const void *const a__ = (EXPR);             \
  76     if (a__ != NULL && a__ != (void *) 1)       \
  77       ggc_set_mark (a__);                       \
  78   } while (0)
  79
  80 /* A GC implementation must provide these functions.  */
  81
  82 /* Initialize the garbage collector.  */
  83 extern void init_ggc            PARAMS ((void));
  84 extern void init_stringpool     PARAMS ((void));
  85
  86 /* Start a new GGC context.  Memory allocated in previous contexts
  87    will not be collected while the new context is active.  */
  88 extern void ggc_push_context    PARAMS ((void));
  89
  90 /* Finish a GC context.  Any uncollected memory in the new context
  91    will be merged with the old context.  */
  92 extern void ggc_pop_context     PARAMS ((void));
  93
  94 /* Allocation.  */
  95
  96 /* The internal primitive.  */
  97 extern void *ggc_alloc          PARAMS ((size_t));
  98 /* Like ggc_alloc, but allocates cleared memory.  */
  99 extern void *ggc_alloc_cleared  PARAMS ((size_t));
 100 /* Resize a block.  */
 101 extern void *ggc_realloc        PARAMS ((void *, size_t));
 102 /* Like ggc_alloc_cleared, but performs a multiplication.  */
 103 extern void *ggc_calloc         PARAMS ((size_t, size_t));
 104
 105 #define ggc_alloc_rtx(NSLOTS)                                             \
 106   ((struct rtx_def *) ggc_alloc (sizeof (struct rtx_def)                  \
 107                                  + ((NSLOTS) - 1) * sizeof (rtunion)))
 108
 109 #define ggc_alloc_rtvec(NELT)                                             \
 110   ((struct rtvec_def *) ggc_alloc (sizeof (struct rtvec_def)              \
 111                                    + ((NELT) - 1) * sizeof (rtx)))
 112
 113 #define ggc_alloc_tree(LENGTH) ((union tree_node *) ggc_alloc (LENGTH))
 114
 115 #define htab_create_ggc(SIZE, HASH, EQ, DEL) \
 116   htab_create_alloc (SIZE, HASH, EQ, DEL, ggc_calloc, NULL)
 117
 118 /* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS.
 119    If LENGTH is -1, then CONTENTS is assumed to be a
 120    null-terminated string and the memory sized accordingly.  */
 121 extern const char *ggc_alloc_string     PARAMS ((const char *contents,
 122                                                  int length));
 123
 124 /* Make a copy of S, in GC-able memory.  */
 125 #define ggc_strdup(S) ggc_alloc_string((S), -1)
 126
 127 /* Invoke the collector.  Garbage collection occurs only when this
 128    function is called, not during allocations.  */
 129 extern void ggc_collect                 PARAMS ((void));
 130
 131 /* Actually set the mark on a particular region of memory, but don't
 132    follow pointers.  This function is called by ggc_mark_*.  It
 133    returns zero if the object was not previously marked; nonzero if
 134    the object was already marked, or if, for any other reason,
 135    pointers in this data structure should not be traversed.  */
 136 extern int ggc_set_mark                 PARAMS ((const void *));
 137
 138 /* Return 1 if P has been marked, zero otherwise.
 139    P must have been allocated by the GC allocator; it mustn't point to
 140    static objects, stack variables, or memory allocated with malloc.  */
 141 extern int ggc_marked_p                 PARAMS ((const void *));
 142
 143 /* Statistics.  */
 144
 145 /* This structure contains the statistics common to all collectors.
 146    Particular collectors can extend this structure.  */
 147 typedef struct ggc_statistics
 148 {
 149   /* The Ith element is the number of nodes allocated with code I.  */
 150   unsigned num_trees[256];
 151   /* The Ith element is the number of bytes allocated by nodes with
 152      code I.  */
 153   size_t size_trees[256];
 154   /* The Ith element is the number of nodes allocated with code I.  */
 155   unsigned num_rtxs[256];
 156   /* The Ith element is the number of bytes allocated by nodes with
 157      code I.  */
 158   size_t size_rtxs[256];
 159   /* The total size of the tree nodes allocated.  */
 160   size_t total_size_trees;
 161   /* The total size of the RTL nodes allocated.  */
 162   size_t total_size_rtxs;
 163   /* The total number of tree nodes allocated.  */
 164   unsigned total_num_trees;
 165   /* The total number of RTL nodes allocated.  */
 166   unsigned total_num_rtxs;
 167 } ggc_statistics;
 168
 169 /* Return the number of bytes allocated at the indicated address.  */
 170 extern size_t ggc_get_size              PARAMS ((const void *));
 171
 172 /* Used by the various collectors to gather and print statistics that
 173    do not depend on the collector in use.  */
 174 extern void ggc_print_common_statistics PARAMS ((FILE *, ggc_statistics *));
 175
 176 /* Print allocation statistics.  */
 177 extern void ggc_print_statistics        PARAMS ((void));
 178 extern void stringpool_statistics       PARAMS ((void));