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 it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any
11 GNU CC is distributed in the hope that it will be useful, but WITHOUT
12 ANY 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 GNU CC; see the file COPYING. If not, write to the Free
18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
21 #include "gansidecl.h"
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. */
27 /* These structures are defined in various headers throughout the
28 compiler. However, rather than force everyone who includes this
29 header to include all the headers in which they are declared, we
30 just forward-declare them here. */
42 /* Constants for general use. */
43 extern char *empty_string;
45 /* Trees that have been marked, but whose children still need marking. */
46 extern varray_type ggc_pending_trees;
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 *));
68 /* If EXPR is not NULL and previously unmarked, mark it and evaluate
69 to true. Otherwise evaluate to false. */
70 #define ggc_test_and_set_mark(EXPR) \
71 ((EXPR) != NULL && ! ggc_set_mark (EXPR))
73 #define ggc_mark_rtx(EXPR) \
76 if (ggc_test_and_set_mark (r__)) \
77 ggc_mark_rtx_children (r__); \
80 #define ggc_mark_tree(EXPR) \
83 if (ggc_test_and_set_mark (t__)) \
84 VARRAY_PUSH_TREE (ggc_pending_trees, t__); \
87 #define ggc_mark_rtvec(EXPR) \
90 if (ggc_test_and_set_mark (v__)) \
91 ggc_mark_rtvec_children (v__); \
94 #define ggc_mark_string(EXPR) \
96 const char *s__ = (EXPR); \
101 #define ggc_mark(EXPR) \
103 const void *a__ = (EXPR); \
105 ggc_set_mark (a__); \
108 /* Mark, but only if it was allocated in collectable memory. */
109 extern void ggc_mark_if_gcable PARAMS ((const void *));
111 /* A GC implementation must provide these functions. */
113 /* Initialize the garbage collector. */
114 extern void init_ggc PARAMS ((void));
116 /* Start a new GGC context. Memory allocated in previous contexts
117 will not be collected while the new context is active. */
118 extern void ggc_push_context PARAMS ((void));
120 /* Finish a GC context. Any uncollected memory in the new context
121 will be merged with the old context. */
122 extern void ggc_pop_context PARAMS ((void));
126 /* The internal primitive. */
127 void *ggc_alloc PARAMS ((size_t));
128 /* Like ggc_alloc, but allocates cleared memory. */
129 void *ggc_alloc_cleared PARAMS ((size_t));
131 #define ggc_alloc_rtx(NSLOTS) \
132 ((struct rtx_def *) ggc_alloc (sizeof (struct rtx_def) \
133 + ((NSLOTS) - 1) * sizeof (rtunion)))
135 #define ggc_alloc_rtvec(NELT) \
136 ((struct rtvec_def *) ggc_alloc (sizeof (struct rtvec_def) \
137 + ((NELT) - 1) * sizeof (rtx)))
139 #define ggc_alloc_tree(LENGTH) ((union tree_node *) ggc_alloc (LENGTH))
141 /* Allocate a gc-able string. If CONTENTS is null, then the memory will
142 be uninitialized. If LENGTH is -1, then CONTENTS is assumed to be a
143 null-terminated string and the memory sized accordingly. Otherwise,
144 the memory is filled with LENGTH bytes from CONTENTS. */
145 char *ggc_alloc_string PARAMS ((const char *contents, int length));
147 /* Make a copy of S, in GC-able memory. */
148 #define ggc_strdup(S) ggc_alloc_string((S), -1)
150 /* Invoke the collector. This is really just a hint, but in the case of
151 the simple collector, the only time it will happen. */
152 void ggc_collect PARAMS ((void));
154 /* Actually set the mark on a particular region of memory, but don't
155 follow pointers. This function is called by ggc_mark_*. It
156 returns zero if the object was not previously marked; non-zero if
157 the object was already marked, or if, for any other reason,
158 pointers in this data structure should not be traversed. */
159 int ggc_set_mark PARAMS ((const void *));
161 /* Callbacks to the languages. */
163 /* This is the language's opportunity to mark nodes held through
164 the lang_specific hooks in the tree. */
165 void lang_mark_tree PARAMS ((union tree_node *));
167 /* The FALSE_LABEL_STACK, declared in except.h, has language-dependent
168 semantics. If a front-end needs to mark the false label stack, it
169 should set this pointer to a non-NULL value. Otherwise, no marking
171 extern void (*lang_mark_false_label_stack) PARAMS ((struct label_node *));
173 /* Mark functions for various structs scattered about. */
175 void mark_eh_status PARAMS ((struct eh_status *));
176 void mark_emit_status PARAMS ((struct emit_status *));
177 void mark_expr_status PARAMS ((struct expr_status *));
178 void mark_stmt_status PARAMS ((struct stmt_status *));
179 void mark_varasm_status PARAMS ((struct varasm_status *));
180 void mark_optab PARAMS ((void *));
184 /* This structure contains the statistics common to all collectors.
185 Particular collectors can extend this structure. */
186 typedef struct ggc_statistics
188 /* The Ith element is the number of nodes allocated with code I. */
189 unsigned num_trees[256];
190 /* The Ith element is the number of bytes allocated by nodes with
192 size_t size_trees[256];
193 /* The Ith element is the number of nodes allocated with code I. */
194 unsigned num_rtxs[256];
195 /* The Ith element is the number of bytes allocated by nodes with
197 size_t size_rtxs[256];
198 /* The total size of the tree nodes allocated. */
199 size_t total_size_trees;
200 /* The total size of the RTL nodes allocated. */
201 size_t total_size_rtxs;
202 /* The total number of tree nodes allocated. */
203 unsigned total_num_trees;
204 /* The total number of RTL nodes allocated. */
205 unsigned total_num_rtxs;
208 /* Return the number of bytes allocated at the indicated address. */
209 size_t ggc_get_size PARAMS ((const void *));
211 /* Used by the various collectors to gather and print statistics that
212 do not depend on the collector in use. */
213 void ggc_print_common_statistics PARAMS ((FILE *, ggc_statistics *));
215 /* Print allocation statistics. */
216 extern void ggc_print_statistics PARAMS ((void));