1 /* Garbage collection for the GNU compiler.
2 Copyright (C) 1998, 1999, 2000 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. */
21 #include "gansidecl.h"
23 /* Symbols are marked with `ggc' for `gcc gc' so as not to interfere with
24 an external gc library that might be linked in. */
26 /* Language-specific code defines this variable to be either one (if
27 it wants garbage collection), or zero (if it does not). */
30 /* These structures are defined in various headers throughout the
31 compiler. However, rather than force everyone who includes this
32 header to include all the headers in which they are declared, we
33 just forward-declare them here. */
43 struct varray_head_tag
;
45 /* Constants for general use. */
46 extern char *empty_string
;
48 /* Manipulate global roots that are needed between calls to gc. */
49 void ggc_add_root
PARAMS ((void *base
, int nelt
, int size
, void (*)(void *)));
50 void ggc_add_rtx_root
PARAMS ((struct rtx_def
**, int nelt
));
51 void ggc_add_tree_root
PARAMS ((union tree_node
**, int nelt
));
52 void ggc_add_string_root
PARAMS ((char **, int nelt
));
53 void ggc_add_rtx_varray_root
PARAMS ((struct varray_head_tag
**, int nelt
));
54 void ggc_add_tree_varray_root
PARAMS ((struct varray_head_tag
**, int nelt
));
55 void ggc_add_tree_hash_table_root
PARAMS ((struct hash_table
**, int nelt
));
56 void ggc_del_root
PARAMS ((void *base
));
58 /* Mark nodes from the gc_add_root callback. These functions follow
59 pointers to mark other objects too. */
60 extern void ggc_mark_rtx_varray
PARAMS ((struct varray_head_tag
*));
61 extern void ggc_mark_tree_varray
PARAMS ((struct varray_head_tag
*));
62 extern void ggc_mark_tree_hash_table
PARAMS ((struct hash_table
*));
63 extern void ggc_mark_roots
PARAMS ((void));
65 extern void ggc_mark_rtx_children
PARAMS ((struct rtx_def
*));
66 extern void ggc_mark_rtvec_children
PARAMS ((struct rtvec_def
*));
67 extern void ggc_mark_tree_children
PARAMS ((union tree_node
*));
69 /* If EXPR is not NULL and previously unmarked, mark it and evaluate
70 to true. Otherwise evaluate to false. */
71 #define ggc_test_and_set_mark(EXPR) \
72 ((EXPR) != NULL && ! ggc_set_mark (EXPR))
74 #define ggc_mark_rtx(EXPR) \
77 if (ggc_test_and_set_mark (r__)) \
78 ggc_mark_rtx_children (r__); \
81 #define ggc_mark_tree(EXPR) \
84 if (ggc_test_and_set_mark (t__)) \
85 ggc_mark_tree_children (t__); \
88 #define ggc_mark_rtvec(EXPR) \
91 if (ggc_test_and_set_mark (v__)) \
92 ggc_mark_rtvec_children (v__); \
95 #define ggc_mark_string(EXPR) \
102 #define ggc_mark(EXPR) \
104 void *a__ = (EXPR); \
106 ggc_set_mark (a__); \
109 /* Mark, but only if it was allocated in collectable memory. */
110 extern void ggc_mark_if_gcable
PARAMS ((void *));
112 /* A GC implementation must provide these functions. */
114 /* Initialize the garbage collector. */
115 extern void init_ggc
PARAMS ((void));
117 /* Start a new GGC context. Memory allocated in previous contexts
118 will not be collected while the new context is active. */
119 extern void ggc_push_context
PARAMS ((void));
121 /* Finish a GC context. Any uncollected memory in the new context
122 will be merged with the old context. */
123 extern void ggc_pop_context
PARAMS ((void));
127 /* The internal primitive. */
128 void *ggc_alloc_obj
PARAMS ((size_t, int));
130 #define ggc_alloc_rtx(NSLOTS) \
131 ((struct rtx_def *) ggc_alloc_obj (sizeof (struct rtx_def) \
132 + ((NSLOTS) - 1) * sizeof (rtunion), 1))
134 #define ggc_alloc_rtvec(NELT) \
135 ((struct rtvec_def *) ggc_alloc_obj (sizeof (struct rtvec_def) \
136 + ((NELT) - 1) * sizeof (rtx), 1))
138 #define ggc_alloc_tree(LENGTH) \
139 ((union tree_node *) ggc_alloc_obj ((LENGTH), 1))
141 #define ggc_alloc(SIZE) ggc_alloc_obj((SIZE), 0)
143 char *ggc_alloc_string
PARAMS ((const char *contents
, int length
));
145 /* Invoke the collector. This is really just a hint, but in the case of
146 the simple collector, the only time it will happen. */
147 void ggc_collect
PARAMS ((void));
149 /* Actually set the mark on a particular region of memory, but don't
150 follow pointers. This function is called by ggc_mark_*. It
151 returns zero if the object was not previously marked; non-zero if
152 the object was already marked, or if, for any other reason,
153 pointers in this data structure should not be traversed. */
154 int ggc_set_mark
PARAMS ((void *));
156 /* Callbacks to the languages. */
158 /* This is the language's opportunity to mark nodes held through
159 the lang_specific hooks in the tree. */
160 void lang_mark_tree
PARAMS ((union tree_node
*));
162 /* The FALSE_LABEL_STACK, declared in except.h, has
163 language-dependent semantics. Each front-end should define this
164 function appropriately. */
165 void lang_mark_false_label_stack
PARAMS ((struct label_node
*));
167 /* Mark functions for various structs scattered about. */
169 void mark_eh_status
PARAMS ((struct eh_status
*));
170 void mark_emit_status
PARAMS ((struct emit_status
*));
171 void mark_expr_status
PARAMS ((struct expr_status
*));
172 void mark_stmt_status
PARAMS ((struct stmt_status
*));
173 void mark_varasm_status
PARAMS ((struct varasm_status
*));
174 void mark_optab
PARAMS ((void *));
178 /* This structure contains the statistics common to all collectors.
179 Particular collectors can extend this structure. */
180 typedef struct ggc_statistics
182 /* The Ith element is the number of nodes allocated with code I. */
183 unsigned num_trees
[256];
184 /* The Ith element is the number of bytes allocated by nodes with
186 size_t size_trees
[256];
187 /* The Ith element is the number of nodes allocated with code I. */
188 unsigned num_rtxs
[256];
189 /* The Ith element is the number of bytes allocated by nodes with
191 size_t size_rtxs
[256];
192 /* The total size of the tree nodes allocated. */
193 size_t total_size_trees
;
194 /* The total size of the RTL nodes allocated. */
195 size_t total_size_rtxs
;
196 /* The total number of tree nodes allocated. */
197 unsigned total_num_trees
;
198 /* The total number of RTL nodes allocated. */
199 unsigned total_num_rtxs
;
202 /* Return the number of bytes allocated at the indicated address. */
203 size_t ggc_get_size
PARAMS ((void *));
205 /* Used by the various collectors to gather and print statistics that
206 do not depend on the collector in use. */
207 void ggc_print_statistics
PARAMS ((FILE *, ggc_statistics
*));