1 /* Simple garbage collection for the GNU compiler.
2 Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
4 This file is part of GCC.
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
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
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
21 /* Generic garbage collection (GC) functions and data, not specific to
22 any particular GC implementation. */
34 /* Statistics about the allocation. */
35 static ggc_statistics
*ggc_stats
;
37 /* The FALSE_LABEL_STACK, declared in except.h, has language-dependent
38 semantics. If a front-end needs to mark the false label stack, it
39 should set this pointer to a non-NULL value. Otherwise, no marking
41 void (*lang_mark_false_label_stack
) PARAMS ((struct label_node
*));
43 /* Trees that have been marked, but whose children still need marking. */
44 varray_type ggc_pending_trees
;
46 static void ggc_mark_rtx_ptr
PARAMS ((void *));
47 static void ggc_mark_tree_ptr
PARAMS ((void *));
48 static void ggc_mark_rtx_varray_ptr
PARAMS ((void *));
49 static void ggc_mark_tree_varray_ptr
PARAMS ((void *));
50 static void ggc_mark_tree_hash_table_ptr
PARAMS ((void *));
51 static int ggc_htab_delete
PARAMS ((void **, void *));
52 static void ggc_mark_trees
PARAMS ((void));
53 static bool ggc_mark_tree_hash_table_entry
PARAMS ((struct hash_entry
*,
56 /* Maintain global roots that are preserved during GC. */
58 /* Global roots that are preserved during calls to gc. */
62 struct ggc_root
*next
;
66 void (*cb
) PARAMS ((void *));
69 static struct ggc_root
*roots
;
71 /* Add BASE as a new garbage collection root. It is an array of
72 length NELT with each element SIZE bytes long. CB is a
73 function that will be called with a pointer to each element
74 of the array; it is the intention that CB call the appropriate
75 routine to mark gc-able memory for that element. */
78 ggc_add_root (base
, nelt
, size
, cb
)
81 void (*cb
) PARAMS ((void *));
83 struct ggc_root
*x
= (struct ggc_root
*) xmalloc (sizeof (*x
));
94 /* Register an array of rtx as a GC root. */
97 ggc_add_rtx_root (base
, nelt
)
101 ggc_add_root (base
, nelt
, sizeof (rtx
), ggc_mark_rtx_ptr
);
104 /* Register an array of trees as a GC root. */
107 ggc_add_tree_root (base
, nelt
)
111 ggc_add_root (base
, nelt
, sizeof (tree
), ggc_mark_tree_ptr
);
114 /* Register a varray of rtxs as a GC root. */
117 ggc_add_rtx_varray_root (base
, nelt
)
121 ggc_add_root (base
, nelt
, sizeof (varray_type
),
122 ggc_mark_rtx_varray_ptr
);
125 /* Register a varray of trees as a GC root. */
128 ggc_add_tree_varray_root (base
, nelt
)
132 ggc_add_root (base
, nelt
, sizeof (varray_type
),
133 ggc_mark_tree_varray_ptr
);
136 /* Register a hash table of trees as a GC root. */
139 ggc_add_tree_hash_table_root (base
, nelt
)
140 struct hash_table
**base
;
143 ggc_add_root (base
, nelt
, sizeof (struct hash_table
*),
144 ggc_mark_tree_hash_table_ptr
);
147 /* Remove the previously registered GC root at BASE. */
153 struct ggc_root
*x
, **p
;
155 p
= &roots
, x
= roots
;
171 /* Add a hash table to be scanned when all roots have been processed. We
172 delete any entry in the table that has not been marked. */
176 struct d_htab_root
*next
;
178 ggc_htab_marked_p marked_p
;
182 static struct d_htab_root
*d_htab_roots
;
184 /* Add X, an htab, to a list of htabs that contain objects which are allocated
185 from GC memory. Once all other roots are marked, we check each object in
186 the htab to see if it has already been marked. If not, it is deleted.
188 MARKED_P, if specified, is a function that returns 1 if the entry is to
189 be considered as "marked". If not present, the data structure pointed to
190 by the htab slot is tested. This function should be supplied if some
191 other object (such as something pointed to by that object) should be tested
192 in which case the function tests whether that object (or objects) are
193 marked (using ggc_marked_p) and returns nonzero if it is.
195 MARK, if specified, is a function that is passed the contents of a slot
196 that has been determined to have been "marked" (via the above function)
197 and marks any other objects pointed to by that object. For example,
198 we might have a hash table of memory attribute blocks, which are pointed
199 to by a MEM RTL but have a pointer to a DECL. MARKED_P in that case will
200 not be specified because we want to know if the attribute block is pointed
201 to by the MEM, but MARK must be specified because if the block has been
202 marked, we need to mark the DECL. */
205 ggc_add_deletable_htab (x
, marked_p
, mark
)
207 ggc_htab_marked_p marked_p
;
210 struct d_htab_root
*r
211 = (struct d_htab_root
*) xmalloc (sizeof (struct d_htab_root
));
213 r
->next
= d_htab_roots
;
214 r
->htab
= (htab_t
) x
;
215 r
->marked_p
= marked_p
? marked_p
: ggc_marked_p
;
220 /* Process a slot of an htab by deleting it if it has not been marked. */
223 ggc_htab_delete (slot
, info
)
227 struct d_htab_root
*r
= (struct d_htab_root
*) info
;
229 if (! (*r
->marked_p
) (*slot
))
230 htab_clear_slot (r
->htab
, slot
);
237 /* Iterate through all registered roots and mark each element. */
243 struct d_htab_root
*y
;
245 VARRAY_TREE_INIT (ggc_pending_trees
, 4096, "ggc_pending_trees");
247 for (x
= roots
; x
!= NULL
; x
= x
->next
)
250 int s
= x
->size
, n
= x
->nelt
;
251 void (*cb
) PARAMS ((void *)) = x
->cb
;
254 for (i
= 0; i
< n
; ++i
, elt
+= s
)
258 /* Mark all the queued up trees, and their children. */
260 VARRAY_FREE (ggc_pending_trees
);
262 /* Now scan all hash tables that have objects which are to be deleted if
263 they are not already marked. Since these may mark more trees, we need
264 to reinitialize that varray. */
265 VARRAY_TREE_INIT (ggc_pending_trees
, 1024, "ggc_pending_trees");
267 for (y
= d_htab_roots
; y
!= NULL
; y
= y
->next
)
268 htab_traverse (y
->htab
, ggc_htab_delete
, (PTR
) y
);
270 VARRAY_FREE (ggc_pending_trees
);
273 /* R had not been previously marked, but has now been marked via
274 ggc_set_mark. Now recurse and process the children. */
277 ggc_mark_rtx_children (r
)
286 enum rtx_code code
= GET_CODE (r
);
287 /* This gets set to a child rtx to eliminate tail recursion. */
290 /* Collect statistics, if appropriate. */
293 ++ggc_stats
->num_rtxs
[(int) code
];
294 ggc_stats
->size_rtxs
[(int) code
] += ggc_get_size (r
);
297 /* ??? If (some of) these are really pass-dependent info, do we
298 have any right poking our noses in? */
302 ggc_mark (MEM_ATTRS (r
));
305 ggc_mark_rtx (JUMP_LABEL (r
));
308 ggc_mark_rtx (LABEL_REFS (r
));
311 ggc_mark_rtx (LABEL_NEXTREF (r
));
312 ggc_mark_rtx (CONTAINING_INSN (r
));
315 ggc_mark_tree (ADDRESSOF_DECL (r
));
318 ggc_mark_rtx (CONST_DOUBLE_CHAIN (r
));
321 switch (NOTE_LINE_NUMBER (r
))
323 case NOTE_INSN_RANGE_BEG
:
324 case NOTE_INSN_RANGE_END
:
326 case NOTE_INSN_EXPECTED_VALUE
:
327 ggc_mark_rtx (NOTE_RANGE_INFO (r
));
330 case NOTE_INSN_BLOCK_BEG
:
331 case NOTE_INSN_BLOCK_END
:
332 ggc_mark_tree (NOTE_BLOCK (r
));
344 for (fmt
= GET_RTX_FORMAT (GET_CODE (r
)), i
= 0; *fmt
; ++fmt
, ++i
)
351 if (ggc_test_and_set_mark (exp
))
353 if (next_rtx
== NULL
)
356 ggc_mark_rtx_children (exp
);
360 ggc_mark_rtvec (XVEC (r
, i
));
365 while ((r
= next_rtx
) != NULL
);
368 /* V had not been previously marked, but has now been marked via
369 ggc_set_mark. Now recurse and process the children. */
372 ggc_mark_rtvec_children (v
)
377 i
= GET_NUM_ELEM (v
);
379 ggc_mark_rtx (RTVEC_ELT (v
, i
));
382 /* Recursively set marks on all of the children of the
383 GCC_PENDING_TREES. */
388 while (ggc_pending_trees
->elements_used
)
393 t
= VARRAY_TOP_TREE (ggc_pending_trees
);
394 VARRAY_POP (ggc_pending_trees
);
395 code
= TREE_CODE (t
);
397 /* Collect statistics, if appropriate. */
400 ++ggc_stats
->num_trees
[(int) code
];
401 ggc_stats
->size_trees
[(int) code
] += ggc_get_size (t
);
404 /* Bits from common. */
405 ggc_mark_tree (TREE_TYPE (t
));
406 ggc_mark_tree (TREE_CHAIN (t
));
408 /* Some nodes require special handling. */
412 ggc_mark_tree (TREE_PURPOSE (t
));
413 ggc_mark_tree (TREE_VALUE (t
));
418 int i
= TREE_VEC_LENGTH (t
);
421 ggc_mark_tree (TREE_VEC_ELT (t
, i
));
426 ggc_mark_tree (TREE_REALPART (t
));
427 ggc_mark_tree (TREE_IMAGPART (t
));
431 ggc_mark_rtx (DECL_INCOMING_RTL (t
));
435 ggc_mark_tree (DECL_FIELD_BIT_OFFSET (t
));
438 case IDENTIFIER_NODE
:
446 /* But in general we can handle them by class. */
447 switch (TREE_CODE_CLASS (code
))
449 case 'd': /* A decl node. */
450 ggc_mark_tree (DECL_SIZE (t
));
451 ggc_mark_tree (DECL_SIZE_UNIT (t
));
452 ggc_mark_tree (DECL_NAME (t
));
453 ggc_mark_tree (DECL_CONTEXT (t
));
454 ggc_mark_tree (DECL_ARGUMENTS (t
));
455 ggc_mark_tree (DECL_RESULT_FLD (t
));
456 ggc_mark_tree (DECL_INITIAL (t
));
457 ggc_mark_tree (DECL_ABSTRACT_ORIGIN (t
));
458 ggc_mark_tree (DECL_SECTION_NAME (t
));
459 ggc_mark_tree (DECL_ATTRIBUTES (t
));
460 if (DECL_RTL_SET_P (t
))
461 ggc_mark_rtx (DECL_RTL (t
));
462 ggc_mark_rtx (DECL_LIVE_RANGE_RTL (t
));
463 ggc_mark_tree (DECL_VINDEX (t
));
464 if (DECL_ASSEMBLER_NAME_SET_P (t
))
465 ggc_mark_tree (DECL_ASSEMBLER_NAME (t
));
466 if (TREE_CODE (t
) == FUNCTION_DECL
&& DECL_SAVED_INSNS (t
))
467 ggc_mark_struct_function (DECL_SAVED_INSNS (t
));
471 case 't': /* A type node. */
472 ggc_mark_tree (TYPE_SIZE (t
));
473 ggc_mark_tree (TYPE_SIZE_UNIT (t
));
474 ggc_mark_tree (TYPE_ATTRIBUTES (t
));
475 ggc_mark_tree (TYPE_VALUES (t
));
476 ggc_mark_tree (TYPE_POINTER_TO (t
));
477 ggc_mark_tree (TYPE_REFERENCE_TO (t
));
478 ggc_mark_tree (TYPE_NAME (t
));
479 ggc_mark_tree (TYPE_MIN_VALUE (t
));
480 ggc_mark_tree (TYPE_MAX_VALUE (t
));
481 ggc_mark_tree (TYPE_NEXT_VARIANT (t
));
482 ggc_mark_tree (TYPE_MAIN_VARIANT (t
));
483 ggc_mark_tree (TYPE_BINFO (t
));
484 ggc_mark_tree (TYPE_CONTEXT (t
));
488 case 'b': /* A lexical block. */
489 ggc_mark_tree (BLOCK_VARS (t
));
490 ggc_mark_tree (BLOCK_SUBBLOCKS (t
));
491 ggc_mark_tree (BLOCK_SUPERCONTEXT (t
));
492 ggc_mark_tree (BLOCK_ABSTRACT_ORIGIN (t
));
495 case 'c': /* A constant. */
496 ggc_mark_rtx (TREE_CST_RTL (t
));
499 case 'r': case '<': case '1':
500 case '2': case 'e': case 's': /* Expressions. */
502 int i
= TREE_CODE_LENGTH (TREE_CODE (t
));
503 int first_rtl
= first_rtl_op (TREE_CODE (t
));
508 ggc_mark_rtx ((rtx
) TREE_OPERAND (t
, i
));
510 ggc_mark_tree (TREE_OPERAND (t
, i
));
522 /* Mark all the elements of the varray V, which contains rtxs. */
525 ggc_mark_rtx_varray (v
)
531 for (i
= v
->num_elements
- 1; i
>= 0; --i
)
532 ggc_mark_rtx (VARRAY_RTX (v
, i
));
535 /* Mark all the elements of the varray V, which contains trees. */
538 ggc_mark_tree_varray (v
)
544 for (i
= v
->num_elements
- 1; i
>= 0; --i
)
545 ggc_mark_tree (VARRAY_TREE (v
, i
));
548 /* Mark the hash table-entry HE. Its key field is really a tree. */
551 ggc_mark_tree_hash_table_entry (he
, k
)
552 struct hash_entry
*he
;
553 hash_table_key k ATTRIBUTE_UNUSED
;
555 ggc_mark_tree ((tree
) he
->key
);
559 /* Mark all the elements of the hash-table H, which contains trees. */
562 ggc_mark_tree_hash_table (ht
)
563 struct hash_table
*ht
;
565 hash_traverse (ht
, ggc_mark_tree_hash_table_entry
, /*info=*/0);
568 /* Type-correct function to pass to ggc_add_root. It just forwards
569 *ELT (which is an rtx) to ggc_mark_rtx. */
572 ggc_mark_rtx_ptr (elt
)
575 ggc_mark_rtx (*(rtx
*) elt
);
578 /* Type-correct function to pass to ggc_add_root. It just forwards
579 *ELT (which is a tree) to ggc_mark_tree. */
582 ggc_mark_tree_ptr (elt
)
585 ggc_mark_tree (*(tree
*) elt
);
588 /* Type-correct function to pass to ggc_add_root. It just forwards
589 ELT (which is really a varray_type *) to ggc_mark_rtx_varray. */
592 ggc_mark_rtx_varray_ptr (elt
)
595 ggc_mark_rtx_varray (*(varray_type
*) elt
);
598 /* Type-correct function to pass to ggc_add_root. It just forwards
599 ELT (which is really a varray_type *) to ggc_mark_tree_varray. */
602 ggc_mark_tree_varray_ptr (elt
)
605 ggc_mark_tree_varray (*(varray_type
*) elt
);
608 /* Type-correct function to pass to ggc_add_root. It just forwards
609 ELT (which is really a struct hash_table **) to
610 ggc_mark_tree_hash_table. */
613 ggc_mark_tree_hash_table_ptr (elt
)
616 ggc_mark_tree_hash_table (*(struct hash_table
**) elt
);
619 /* Allocate a block of memory, then clear it. */
621 ggc_alloc_cleared (size
)
624 void *buf
= ggc_alloc (size
);
625 memset (buf
, 0, size
);
629 /* Print statistics that are independent of the collector in use. */
630 #define SCALE(x) ((unsigned long) ((x) < 1024*10 \
632 : ((x) < 1024*1024*10 \
634 : (x) / (1024*1024))))
635 #define LABEL(x) ((x) < 1024*10 ? ' ' : ((x) < 1024*1024*10 ? 'k' : 'M'))
638 ggc_print_common_statistics (stream
, stats
)
640 ggc_statistics
*stats
;
644 /* Set the pointer so that during collection we will actually gather
648 /* Then do one collection to fill in the statistics. */
651 /* Total the statistics. */
652 for (code
= 0; code
< MAX_TREE_CODES
; ++code
)
654 stats
->total_num_trees
+= stats
->num_trees
[code
];
655 stats
->total_size_trees
+= stats
->size_trees
[code
];
657 for (code
= 0; code
< NUM_RTX_CODE
; ++code
)
659 stats
->total_num_rtxs
+= stats
->num_rtxs
[code
];
660 stats
->total_size_rtxs
+= stats
->size_rtxs
[code
];
663 /* Print the statistics for trees. */
664 fprintf (stream
, "\n%-17s%10s %16s %10s\n", "Tree",
665 "Number", "Bytes", "% Total");
666 for (code
= 0; code
< MAX_TREE_CODES
; ++code
)
667 if (ggc_stats
->num_trees
[code
])
669 fprintf (stream
, "%-17s%10u%16ld%c %10.3f\n",
670 tree_code_name
[code
],
671 ggc_stats
->num_trees
[code
],
672 SCALE (ggc_stats
->size_trees
[code
]),
673 LABEL (ggc_stats
->size_trees
[code
]),
674 (100 * ((double) ggc_stats
->size_trees
[code
])
675 / ggc_stats
->total_size_trees
));
678 "%-17s%10u%16ld%c\n", "Total",
679 ggc_stats
->total_num_trees
,
680 SCALE (ggc_stats
->total_size_trees
),
681 LABEL (ggc_stats
->total_size_trees
));
683 /* Print the statistics for RTL. */
684 fprintf (stream
, "\n%-17s%10s %16s %10s\n", "RTX",
685 "Number", "Bytes", "% Total");
686 for (code
= 0; code
< NUM_RTX_CODE
; ++code
)
687 if (ggc_stats
->num_rtxs
[code
])
689 fprintf (stream
, "%-17s%10u%16ld%c %10.3f\n",
691 ggc_stats
->num_rtxs
[code
],
692 SCALE (ggc_stats
->size_rtxs
[code
]),
693 LABEL (ggc_stats
->size_rtxs
[code
]),
694 (100 * ((double) ggc_stats
->size_rtxs
[code
])
695 / ggc_stats
->total_size_rtxs
));
698 "%-17s%10u%16ld%c\n", "Total",
699 ggc_stats
->total_num_rtxs
,
700 SCALE (ggc_stats
->total_size_rtxs
),
701 LABEL (ggc_stats
->total_size_rtxs
));
703 /* Don't gather statistics any more. */