1 /* Simple garbage collection for the GNU compiler.
2 Copyright (C) 1998 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
30 /* Debugging flags. */
32 /* Zap memory before freeing to catch dangling pointers. */
35 /* Log alloc and release. Don't enable this unless you want a
36 really really lot of data. */
39 /* Global lists of roots, rtxs, and trees. */
43 struct ggc_root *next;
47 void (*cb) PROTO ((void *));
50 static struct ggc_root *roots;
54 struct ggc_rtx *chain;
60 struct ggc_rtvec *chain;
66 struct ggc_tree *chain;
72 struct ggc_string *chain;
77 /* A generic allocation, with an external mark bit. */
81 struct ggc_any *chain;
84 /* Make sure the data is reasonably aligned. */
92 #define GGC_STRING_MAGIC ((unsigned int)0xa1b2c3d4)
96 struct ggc_status *next;
98 struct ggc_rtvec *vecs;
99 struct ggc_tree *trees;
100 struct ggc_string *strings;
101 struct ggc_any *anys;
102 size_t bytes_alloced_since_gc;
105 /* A chain of GGC contexts. The currently active context is at the
106 front of the chain. */
107 static struct ggc_status *ggc_chain;
109 /* Some statistics. */
111 static int n_rtxs_collected;
112 static int n_vecs_collected;
113 static int n_trees_collected;
114 static int n_strings_collected;
115 static int n_anys_collected;
122 /* Local function prototypes. */
124 static void ggc_free_rtx PROTO ((struct ggc_rtx *r));
125 static void ggc_free_tree PROTO ((struct ggc_tree *t));
126 static void ggc_mark_rtx_ptr PROTO ((void *elt));
127 static void ggc_mark_tree_ptr PROTO ((void *elt));
128 static void ggc_mark_string_ptr PROTO ((void *elt));
129 static void ggc_mark_tree_varray_ptr PROTO ((void *elt));
130 static void ggc_mark_tree_hash_table_ptr PROTO ((void *elt));
131 static boolean ggc_mark_tree_hash_table_entry PROTO ((struct hash_entry *,
134 /* Called once to initialize the garbage collector. */
137 init_ggc PROTO ((void))
139 /* Initialize the global context. */
143 dump = fopen ("zgcdump", "w");
148 /* Start a new GGC context. Memory allocated in previous contexts
149 will not be collected while the new context is active. */
152 ggc_push_context PROTO ((void))
154 struct ggc_status *gs = (struct ggc_status *) xcalloc (1, sizeof (*gs));
155 gs->next = ggc_chain;
159 /* Finish a GC context. Any uncollected memory in the new context
160 will be merged with the old context. */
163 ggc_pop_context PROTO ((void))
168 struct ggc_string *s;
169 struct ggc_status *gs;
178 r->chain = gs->next->rtxs;
179 gs->next->rtxs = gs->rtxs;
187 v->chain = gs->next->vecs;
188 gs->next->vecs = gs->vecs;
196 t->chain = gs->next->trees;
197 gs->next->trees = gs->trees;
205 s->chain = gs->next->strings;
206 gs->next->strings = gs->strings;
209 ggc_chain = gs->next;
213 /* These allocators are dreadfully simple, with no caching whatsoever so
214 that Purify-like tools that do allocation versioning can catch errors.
215 This collector is never going to go fast anyway. */
218 ggc_alloc_rtx (nslots)
222 int size = sizeof(*n) + (nslots-1) * sizeof(rtunion);
224 n = (struct ggc_rtx *) xcalloc (1, size);
225 n->chain = ggc_chain->rtxs;
229 fprintf (dump, "alloc rtx %p\n", &n->rtx);
232 ggc_chain->bytes_alloced_since_gc += size;
238 ggc_alloc_rtvec (nelt)
242 int size = sizeof (*v) + (nelt - 1) * sizeof (rtx);
244 v = (struct ggc_rtvec *) xcalloc (1, size);
245 v->chain = ggc_chain->vecs;
249 fprintf(dump, "alloc vec %p\n", &v->vec);
252 ggc_chain->bytes_alloced_since_gc += size;
258 ggc_alloc_tree (length)
262 int size = sizeof(*n) - sizeof(n->tree) + length;
264 n = (struct ggc_tree *) xcalloc (1, size);
265 n->chain = ggc_chain->trees;
266 ggc_chain->trees = n;
269 fprintf(dump, "alloc tree %p\n", &n->tree);
272 ggc_chain->bytes_alloced_since_gc += size;
278 ggc_alloc_string (contents, length)
279 const char *contents;
282 struct ggc_string *s;
287 if (contents == NULL)
289 length = strlen (contents);
292 size = (s->string - (char *)s) + length + 1;
293 s = (struct ggc_string *) xmalloc(size);
294 s->chain = ggc_chain->strings;
295 s->magic_mark = GGC_STRING_MAGIC;
297 bcopy (contents, s->string, length);
298 s->string[length] = 0;
299 ggc_chain->strings = s;
302 fprintf(dump, "alloc string %p\n", &s->string);
305 ggc_chain->bytes_alloced_since_gc += size;
310 /* Like xmalloc, but allocates GC-able memory. */
320 bytes += (&((struct ggc_any *) 0)->u.c - (char *) 0);
322 a = (struct ggc_any *) xmalloc (bytes);
323 a->chain = ggc_chain->anys;
329 /* Freeing a bit of rtl is as simple as calling free. */
336 fprintf (dump, "collect rtx %p\n", &r->rtx);
339 memset (r, 0xAA, sizeof(*r) + ((GET_RTX_LENGTH (r->rtx.code) -1)
346 /* Freeing an rtvec is as simple as calling free. */
353 fprintf(dump, "collect vec %p\n", &v->vec);
356 memset (v, 0xBB, sizeof (*v) + ((GET_NUM_ELEM (&v->vec) - 1)
357 * sizeof (rtunion)));
363 /* Freeing a tree node is almost, but not quite, as simple as calling free.
364 Mostly we need to let the language clean up its lang_specific bits. */
370 switch (TREE_CODE_CLASS (TREE_CODE (&t->tree)))
372 case 'd': /* A decl node. */
373 case 't': /* A type node. */
374 lang_cleanup_tree (&t->tree);
379 fprintf (dump, "collect tree %p\n", &t->tree);
382 memset(&t->tree.common, 0xCC, sizeof(t->tree.common));
388 /* Freeing a string is as simple as calling free. */
392 struct ggc_string *s;
395 fprintf(dump, "collect string %p\n", s->string);
398 s->magic_mark = 0xDDDDDDDD;
414 if (r == NULL_RTX || r->gc_mark)
418 /* ??? If (some of) these are really pass-dependant info, do we have
419 any right poking our noses in? */
420 switch (GET_CODE (r))
423 ggc_mark_rtx (JUMP_LABEL (r));
426 ggc_mark_rtx (LABEL_REFS (r));
429 ggc_mark_rtx (LABEL_NEXTREF (r));
430 ggc_mark_rtx (CONTAINING_INSN (r));
433 ggc_mark_tree (ADDRESSOF_DECL (r));
436 ggc_mark_rtx (CONST_DOUBLE_CHAIN (r));
439 switch (NOTE_LINE_NUMBER (r))
441 case NOTE_INSN_RANGE_START:
442 case NOTE_INSN_RANGE_END:
444 ggc_mark_rtx (NOTE_RANGE_INFO (r));
448 if (NOTE_LINE_NUMBER (r) >= 0)
449 ggc_mark_string (NOTE_SOURCE_FILE (r));
458 for (fmt = GET_RTX_FORMAT (GET_CODE (r)), i = 0; *fmt ; ++fmt, ++i)
463 ggc_mark_rtx (XEXP (r, i));
466 ggc_mark_rtvec (XVEC (r, i));
469 ggc_mark_string (XSTR (r, i));
481 if (v == NULL || v->gc_mark)
485 i = GET_NUM_ELEM (v);
487 ggc_mark_rtx (RTVEC_ELT (v, i));
494 if (t == NULL_TREE || t->common.gc_mark)
496 t->common.gc_mark = 1;
498 /* Bits from common. */
499 ggc_mark_tree (TREE_TYPE (t));
500 ggc_mark_tree (TREE_CHAIN (t));
502 /* Some nodes require special handling. */
503 switch (TREE_CODE (t))
506 ggc_mark_tree (TREE_PURPOSE (t));
507 ggc_mark_tree (TREE_VALUE (t));
512 int i = TREE_VEC_LENGTH (t);
514 ggc_mark_tree (TREE_VEC_ELT (t, i));
519 ggc_mark_tree (TREE_OPERAND (t, 0));
520 ggc_mark_tree (SAVE_EXPR_CONTEXT (t));
521 ggc_mark_rtx (SAVE_EXPR_RTL (t));
525 ggc_mark_rtx (RTL_EXPR_SEQUENCE (t));
526 ggc_mark_rtx (RTL_EXPR_RTL (t));
530 ggc_mark_tree (TREE_OPERAND (t, 0));
531 ggc_mark_tree (TREE_OPERAND (t, 1));
532 ggc_mark_rtx (CALL_EXPR_RTL (t));
536 ggc_mark_tree (TREE_REALPART (t));
537 ggc_mark_tree (TREE_IMAGPART (t));
541 ggc_mark_string (TREE_STRING_POINTER (t));
545 ggc_mark_rtx (DECL_INCOMING_RTL (t));
548 case IDENTIFIER_NODE:
549 ggc_mark_string (IDENTIFIER_POINTER (t));
557 /* But in general we can handle them by class. */
558 switch (TREE_CODE_CLASS (TREE_CODE (t)))
560 case 'd': /* A decl node. */
561 ggc_mark_tree (DECL_SIZE (t));
562 ggc_mark_tree (DECL_NAME (t));
563 ggc_mark_tree (DECL_CONTEXT (t));
564 ggc_mark_tree (DECL_ARGUMENTS (t));
565 ggc_mark_tree (DECL_RESULT (t));
566 ggc_mark_tree (DECL_INITIAL (t));
567 ggc_mark_tree (DECL_ABSTRACT_ORIGIN (t));
568 ggc_mark_tree (DECL_ASSEMBLER_NAME (t));
569 ggc_mark_tree (DECL_SECTION_NAME (t));
570 ggc_mark_tree (DECL_MACHINE_ATTRIBUTES (t));
571 ggc_mark_rtx (DECL_RTL (t));
572 ggc_mark_tree (DECL_VINDEX (t));
576 case 't': /* A type node. */
577 ggc_mark_tree (TYPE_SIZE (t));
578 ggc_mark_tree (TYPE_SIZE_UNIT (t));
579 ggc_mark_tree (TYPE_ATTRIBUTES (t));
580 ggc_mark_tree (TYPE_VALUES (t));
581 ggc_mark_tree (TYPE_POINTER_TO (t));
582 ggc_mark_tree (TYPE_REFERENCE_TO (t));
583 ggc_mark_tree (TYPE_NAME (t));
584 ggc_mark_tree (TYPE_MIN_VALUE (t));
585 ggc_mark_tree (TYPE_MAX_VALUE (t));
586 ggc_mark_tree (TYPE_NEXT_VARIANT (t));
587 ggc_mark_tree (TYPE_MAIN_VARIANT (t));
588 ggc_mark_tree (TYPE_BINFO (t));
589 ggc_mark_tree (TYPE_NONCOPIED_PARTS (t));
590 ggc_mark_tree (TYPE_CONTEXT (t));
594 case 'b': /* A lexical block. */
595 ggc_mark_tree (BLOCK_VARS (t));
596 ggc_mark_tree (BLOCK_TYPE_TAGS (t));
597 ggc_mark_tree (BLOCK_SUBBLOCKS (t));
598 ggc_mark_tree (BLOCK_SUPERCONTEXT (t));
599 ggc_mark_tree (BLOCK_ABSTRACT_ORIGIN (t));
600 ggc_mark_rtx (BLOCK_END_NOTE (t));
603 case 'c': /* A constant. */
604 ggc_mark_rtx (TREE_CST_RTL (t));
607 case 'r': case '<': case '1':
608 case '2': case 'e': case 's': /* Expressions. */
610 int i = tree_code_length[TREE_CODE (t)];
612 ggc_mark_tree (TREE_OPERAND (t, i));
622 /* Mark all the elements of the varray V, which contains trees. */
625 ggc_mark_tree_varray (v)
631 for (i = v->num_elements - 1; i >= 0; --i)
632 ggc_mark_tree (VARRAY_TREE (v, i));
635 /* Mark the hash table-entry HE. It's key field is really a tree. */
638 ggc_mark_tree_hash_table_entry (he, k)
639 struct hash_entry *he;
640 hash_table_key k ATTRIBUTE_UNUSED;
642 ggc_mark_tree ((tree) he->key);
646 /* Mark all the elements of the hash-table H, which contains trees. */
649 ggc_mark_tree_hash_table (ht)
650 struct hash_table *ht;
652 hash_traverse (ht, ggc_mark_tree_hash_table_entry, /*info=*/0);
659 unsigned int *magic = (unsigned int *)s - 1;
664 if ((*magic & ~(unsigned)1) != GGC_STRING_MAGIC)
666 *magic = GGC_STRING_MAGIC | 1;
669 /* Mark P, allocated with ggc_alloc. */
676 ptrdiff_t d = (&((struct ggc_any *) 0)->u.c - (char *) 0);
677 a = (struct ggc_any *) (((char*) p) - d);
681 /* The top level mark-and-sweep routine. */
686 struct ggc_rtx *r, **rp;
687 struct ggc_rtvec *v, **vp;
688 struct ggc_tree *t, **tp;
689 struct ggc_string *s, **sp;
691 struct ggc_status *gs;
692 struct ggc_any *a, **ap;
693 int time, n_rtxs, n_trees, n_vecs, n_strings, n_anys;
696 /* See if it's even worth our while. */
697 if (ggc_chain->bytes_alloced_since_gc < 64*1024)
702 fputs (" {GC ", stderr);
704 time = get_run_time ();
706 /* Clean out all of the GC marks. */
707 for (gs = ggc_chain; gs; gs = gs->next)
709 for (r = gs->rtxs; r != NULL; r = r->chain)
711 for (v = gs->vecs; v != NULL; v = v->chain)
713 for (t = gs->trees; t != NULL; t = t->chain)
714 t->tree.common.gc_mark = 0;
715 for (s = gs->strings; s != NULL; s = s->chain)
716 s->magic_mark = GGC_STRING_MAGIC;
717 for (a = gs->anys; a != NULL; a = a->chain)
721 /* Mark through all the roots. */
722 for (x = roots; x != NULL; x = x->next)
725 int s = x->size, n = x->nelt;
726 void (*cb) PROTO ((void *)) = x->cb;
729 for (i = 0; i < n; ++i, elt += s)
733 /* Sweep the resulting dead nodes. */
737 rp = &ggc_chain->rtxs;
742 struct ggc_rtx *chain = r->chain;
754 n_rtxs_collected += n_rtxs;
758 vp = &ggc_chain->vecs;
763 struct ggc_rtvec *chain = v->chain;
775 n_vecs_collected += n_vecs;
779 tp = &ggc_chain->trees;
780 t = ggc_chain->trees;
784 struct ggc_tree *chain = t->chain;
785 if (!t->tree.common.gc_mark)
796 n_trees_collected += n_trees;
800 sp = &ggc_chain->strings;
801 s = ggc_chain->strings;
805 struct ggc_string *chain = s->chain;
806 if (!(s->magic_mark & 1))
817 n_strings_collected += n_strings;
819 /* The generic data. */
821 ap = &ggc_chain->anys;
826 struct ggc_any *chain = a->chain;
837 n_anys_collected += n_anys;
839 ggc_chain->bytes_alloced_since_gc = 0;
841 time = get_run_time () - time;
846 time = (time + 500) / 1000;
847 fprintf (stderr, "%dr,%dv,%dt,%ds,%da %d.%03d}", n_rtxs, n_vecs,
848 n_trees, n_strings, n_anys, time / 1000, time % 1000);
852 /* Manipulate global roots that are needed between calls to gc. */
855 ggc_add_root (base, nelt, size, cb)
858 void (*cb) PROTO ((void *));
860 struct ggc_root *x = (struct ggc_root *) xmalloc (sizeof(*x));
872 ggc_add_rtx_root (base, nelt)
876 ggc_add_root (base, nelt, sizeof(rtx), ggc_mark_rtx_ptr);
880 ggc_add_tree_root (base, nelt)
884 ggc_add_root (base, nelt, sizeof(tree), ggc_mark_tree_ptr);
888 ggc_add_string_root (base, nelt)
892 ggc_add_root (base, nelt, sizeof(char *), ggc_mark_string_ptr);
895 /* Add V (a varray full of trees) to the list of GC roots. */
898 ggc_add_tree_varray_root (base, nelt)
902 ggc_add_root (base, nelt, sizeof (varray_type),
903 ggc_mark_tree_varray_ptr);
906 /* Add HT (a hash-table where ever key is a tree) to the list of GC
910 ggc_add_tree_hash_table_root (base, nelt)
911 struct hash_table **base;
914 ggc_add_root (base, nelt, sizeof (struct hash_table *),
915 ggc_mark_tree_hash_table_ptr);
922 struct ggc_root *x, **p;
924 p = &roots, x = roots;
941 ggc_mark_rtx_ptr (elt)
944 ggc_mark_rtx (*(rtx *)elt);
948 ggc_mark_tree_ptr (elt)
951 ggc_mark_tree (*(tree *)elt);
954 /* Type-correct function to pass to ggc_add_root. It just forwards
955 ELT (which is really a char **) to ggc_mark_string. */
958 ggc_mark_string_ptr (elt)
961 ggc_mark_string (*(char **)elt);
964 /* Type-correct function to pass to ggc_add_root. It just forwards
965 ELT (which is really a varray_type *) to ggc_mark_tree_varray. */
968 ggc_mark_tree_varray_ptr (elt)
971 ggc_mark_tree_varray (*(varray_type *)elt);
974 /* Type-correct function to pass to ggc_add_root. It just forwards
975 ELT (which is really a struct hash_table **) to
976 ggc_mark_tree_hash_table. */
979 ggc_mark_tree_hash_table_ptr (elt)
982 ggc_mark_tree_hash_table (*(struct hash_table **) elt);
986 /* GDB really should have a memory search function. Since this is just
987 for initial debugging, I won't even pretend to get the __data_start
988 to work on any but alpha-dec-linux-gnu. */
990 search_data(void **start, void *target)
992 extern void *__data_start[];
993 void **_end = (void **)sbrk(0);
996 start = __data_start;
999 if (*start == target)