1 /* Garbage collection for the GNU compiler.
3 Copyright (C) 1998-2014 Free Software Foundation, Inc.
5 This file is part of GCC.
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
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
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/>. */
23 #include "statistics.h"
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. */
28 /* Constants for general use. */
29 extern const char empty_string
[]; /* empty string */
31 /* Internal functions and data structures used by the GTY
32 machinery, including the generated gt*.[hc] files. */
34 #include "gtype-desc.h"
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
,
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
,
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
);
53 /* Used by the gt_pch_n_* routines. Register that an object has a reorder
55 extern void gt_pch_note_reorder (void *, void *, gt_handle_reorder
);
57 /* generated function to clear caches in gc memory. */
58 extern void gt_clear_caches ();
60 /* Mark the object in the first parameter and anything it points to. */
61 typedef void (*gt_pointer_walker
) (void *);
63 /* Structures for the easy way to mark roots.
64 In an array, terminated by having base == NULL. */
70 gt_pointer_walker pchw
;
72 #define LAST_GGC_ROOT_TAB { NULL, 0, 0, NULL, NULL }
73 /* Pointers to arrays of ggc_root_tab, terminated by NULL. */
74 extern const struct ggc_root_tab
* const gt_ggc_rtab
[];
75 extern const struct ggc_root_tab
* const gt_ggc_deletable_rtab
[];
76 extern const struct ggc_root_tab
* const gt_pch_cache_rtab
[];
77 extern const struct ggc_root_tab
* const gt_pch_scalar_rtab
[];
79 /* Structure for hash table cache marking. */
81 struct ggc_cache_tab
{
86 gt_pointer_walker pchw
;
87 int (*marked_p
) (const void *);
89 #define LAST_GGC_CACHE_TAB { NULL, 0, 0, NULL, NULL, NULL }
90 /* Pointers to arrays of ggc_cache_tab, terminated by NULL. */
91 extern const struct ggc_cache_tab
* const gt_ggc_cache_rtab
[];
93 /* If EXPR is not NULL and previously unmarked, mark it and evaluate
94 to true. Otherwise evaluate to false. */
95 #define ggc_test_and_set_mark(EXPR) \
96 ((EXPR) != NULL && ((void *) (EXPR)) != (void *) 1 && ! ggc_set_mark (EXPR))
98 #define ggc_mark(EXPR) \
100 const void *const a__ = (EXPR); \
101 if (a__ != NULL && a__ != (void *) 1) \
102 ggc_set_mark (a__); \
105 /* Actually set the mark on a particular region of memory, but don't
106 follow pointers. This function is called by ggc_mark_*. It
107 returns zero if the object was not previously marked; nonzero if
108 the object was already marked, or if, for any other reason,
109 pointers in this data structure should not be traversed. */
110 extern int ggc_set_mark (const void *);
112 /* Return 1 if P has been marked, zero otherwise.
113 P must have been allocated by the GC allocator; it mustn't point to
114 static objects, stack variables, or memory allocated with malloc. */
115 extern int ggc_marked_p (const void *);
117 /* PCH and GGC handling for strings, mostly trivial. */
118 extern void gt_pch_n_S (const void *);
119 extern void gt_ggc_m_S (const void *);
121 /* End of GTY machinery API. */
123 /* Initialize the string pool. */
124 extern void init_stringpool (void);
126 /* Initialize the garbage collector. */
127 extern void init_ggc (void);
129 /* When true, identifier nodes are considered as GC roots. When
130 false, identifier nodes are treated like any other GC-allocated
131 object, and the identifier hash table is treated as a weak
133 extern bool ggc_protect_identifiers
;
135 /* Write out all GCed objects to F. */
136 extern void gt_pch_save (FILE *f
);
141 /* The internal primitive. */
142 extern void *ggc_internal_alloc (size_t, void (*)(void *), size_t,
143 size_t CXX_MEM_STAT_INFO
)
148 ggc_internal_alloc (size_t s CXX_MEM_STAT_INFO
)
150 return ggc_internal_alloc (s
, NULL
, 0, 1 PASS_MEM_STAT
);
153 extern size_t ggc_round_alloc_size (size_t requested_size
);
155 /* Allocates cleared memory. */
156 extern void *ggc_internal_cleared_alloc (size_t, void (*)(void *),
158 CXX_MEM_STAT_INFO
) ATTRIBUTE_MALLOC
;
162 ggc_internal_cleared_alloc (size_t s CXX_MEM_STAT_INFO
)
164 return ggc_internal_cleared_alloc (s
, NULL
, 0, 1 PASS_MEM_STAT
);
167 /* Resize a block. */
168 extern void *ggc_realloc (void *, size_t CXX_MEM_STAT_INFO
);
170 /* Free a block. To be used when known for certain it's not reachable. */
171 extern void ggc_free (void *);
173 extern void dump_ggc_loc_statistics (bool);
176 #define GGC_RESIZEVEC(T, P, N) \
177 ((T *) ggc_realloc ((P), (N) * sizeof (T) MEM_STAT_INFO))
183 static_cast<T
*> (p
)->~T ();
188 need_finalization_p ()
190 #if GCC_VERSION >= 4003
191 return !__has_trivial_destructor (T
);
199 ggc_alloc (ALONE_CXX_MEM_STAT_INFO
)
201 if (need_finalization_p
<T
> ())
202 return static_cast<T
*> (ggc_internal_alloc (sizeof (T
), finalize
<T
>, 0, 1
205 return static_cast<T
*> (ggc_internal_alloc (sizeof (T
), NULL
, 0, 1
211 ggc_cleared_alloc (ALONE_CXX_MEM_STAT_INFO
)
213 if (need_finalization_p
<T
> ())
214 return static_cast<T
*> (ggc_internal_cleared_alloc (sizeof (T
),
218 return static_cast<T
*> (ggc_internal_cleared_alloc (sizeof (T
), NULL
, 0, 1
224 ggc_vec_alloc (size_t c CXX_MEM_STAT_INFO
)
226 if (need_finalization_p
<T
> ())
227 return static_cast<T
*> (ggc_internal_alloc (c
* sizeof (T
), finalize
<T
>,
228 sizeof (T
), c PASS_MEM_STAT
));
230 return static_cast<T
*> (ggc_internal_alloc (c
* sizeof (T
), NULL
, 0, 0
236 ggc_cleared_vec_alloc (size_t c CXX_MEM_STAT_INFO
)
238 if (need_finalization_p
<T
> ())
239 return static_cast<T
*> (ggc_internal_cleared_alloc (c
* sizeof (T
),
244 return static_cast<T
*> (ggc_internal_cleared_alloc (c
* sizeof (T
), NULL
,
245 0, 0 PASS_MEM_STAT
));
249 ggc_alloc_atomic (size_t s CXX_MEM_STAT_INFO
)
251 return ggc_internal_alloc (s PASS_MEM_STAT
);
254 extern void *ggc_cleared_alloc_htab_ignore_args (size_t, size_t)
257 extern void *ggc_cleared_alloc_ptr_array_two_args (size_t, size_t)
260 #define htab_create_ggc(SIZE, HASH, EQ, DEL) \
261 htab_create_typed_alloc (SIZE, HASH, EQ, DEL, \
262 ggc_cleared_alloc_htab_ignore_args, \
263 ggc_cleared_alloc_ptr_array_two_args, \
266 #define splay_tree_new_ggc(COMPARE, ALLOC_TREE, ALLOC_NODE) \
267 splay_tree_new_typed_alloc (COMPARE, NULL, NULL, &ALLOC_TREE, &ALLOC_NODE, \
268 &ggc_splay_dont_free, NULL)
270 extern void *ggc_splay_alloc (int, void *)
273 extern void ggc_splay_dont_free (void *, void *);
275 /* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS.
276 If LENGTH is -1, then CONTENTS is assumed to be a
277 null-terminated string and the memory sized accordingly. */
278 extern const char *ggc_alloc_string (const char *contents
, int length
281 /* Make a copy of S, in GC-able memory. */
282 #define ggc_strdup(S) ggc_alloc_string ((S), -1 MEM_STAT_INFO)
284 /* Invoke the collector. Garbage collection occurs only when this
285 function is called, not during allocations. */
286 extern void ggc_collect (void);
288 /* Assume that all GGC memory is reachable and grow the limits for next collection. */
289 extern void ggc_grow (void);
291 /* Register an additional root table. This can be useful for some
292 plugins. Does nothing if the passed pointer is NULL. */
293 extern void ggc_register_root_tab (const struct ggc_root_tab
*);
295 /* Register an additional cache table. This can be useful for some
296 plugins. Does nothing if the passed pointer is NULL. */
297 extern void ggc_register_cache_tab (const struct ggc_cache_tab
*);
299 /* Read objects previously saved with gt_pch_save from F. */
300 extern void gt_pch_restore (FILE *f
);
304 /* Print allocation statistics. */
305 extern void ggc_print_statistics (void);
307 extern void stringpool_statistics (void);
310 extern void init_ggc_heuristics (void);
312 #define ggc_alloc_rtvec_sized(NELT) \
313 (rtvec_def *) ggc_internal_alloc (sizeof (struct rtvec_def) \
314 + ((NELT) - 1) * sizeof (rtx)) \
316 /* Memory statistics passing versions of some allocators. Too few of them to
317 make gengtype produce them, so just define the needed ones here. */
318 static inline struct rtx_def
*
319 ggc_alloc_rtx_def_stat (size_t s CXX_MEM_STAT_INFO
)
321 return (struct rtx_def
*) ggc_internal_alloc (s PASS_MEM_STAT
);
324 static inline union tree_node
*
325 ggc_alloc_tree_node_stat (size_t s CXX_MEM_STAT_INFO
)
327 return (union tree_node
*) ggc_internal_alloc (s PASS_MEM_STAT
);
330 static inline union tree_node
*
331 ggc_alloc_cleared_tree_node_stat (size_t s CXX_MEM_STAT_INFO
)
333 return (union tree_node
*) ggc_internal_cleared_alloc (s PASS_MEM_STAT
);
336 static inline struct gimple_statement_base
*
337 ggc_alloc_cleared_gimple_statement_stat (size_t s CXX_MEM_STAT_INFO
)
339 return (struct gimple_statement_base
*)
340 ggc_internal_cleared_alloc (s PASS_MEM_STAT
);
344 gt_ggc_mx (const char *s
)
346 ggc_test_and_set_mark (const_cast<char *> (s
));
350 gt_pch_nx (const char *)
365 gt_pch_nx (unsigned int)