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comparison src/opaque.c @ 428:3ecd8885ac67 r21-2-22

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Import from CVS: tag r21-2-22
author cvs
date Mon, 13 Aug 2007 11:28:15 +0200
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427:0a0253eac470 428:3ecd8885ac67
1 /* Opaque Lisp objects.
2 Copyright (C) 1993, 1994, 1995 Sun Microsystems, Inc.
3 Copyright (C) 1995, 1996 Ben Wing.
4
5 This file is part of XEmacs.
6
7 XEmacs is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 2, or (at your option) any
10 later version.
11
12 XEmacs is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with XEmacs; see the file COPYING. If not, write to
19 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
21
22 /* Synched up with: Not in FSF. */
23
24 /* Written by Ben Wing, October 1993. */
25
26 /* "Opaque" is used internally to hold keep track of allocated memory
27 so it gets GC'd properly, and to store arbitrary data in places
28 where a Lisp_Object is required and which may get GC'd. (e.g. as
29 the argument to record_unwind_protect()). Once created in C,
30 opaque objects cannot be resized.
31
32 OPAQUE OBJECTS SHOULD NEVER ESCAPE TO THE LISP LEVEL. Some code
33 depends on this. As such, opaque objects are a generalization
34 of the Qunbound marker.
35 */
36
37 #include <config.h>
38 #include "lisp.h"
39 #include "opaque.h"
40
41 Lisp_Object Vopaque_ptr_free_list;
42
43 /* Should never, ever be called. (except by an external debugger) */
44 static void
45 print_opaque (Lisp_Object obj, Lisp_Object printcharfun, int escapeflag)
46 {
47 CONST Lisp_Opaque *p = XOPAQUE (obj);
48 char buf[200];
49
50 sprintf (buf, "#<INTERNAL OBJECT (XEmacs bug?) (opaque, size=%lu) 0x%lx>",
51 (long)(p->size), (unsigned long) p);
52 write_c_string (buf, printcharfun);
53 }
54
55 static size_t
56 sizeof_opaque (CONST void *header)
57 {
58 CONST Lisp_Opaque *p = (CONST Lisp_Opaque *) header;
59 return offsetof (Lisp_Opaque, data) + p->size;
60 }
61
62 /* Return an opaque object of size SIZE.
63 If DATA is OPAQUE_CLEAR, the object's data is memset to '\0' bytes.
64 If DATA is OPAQUE_UNINIT, the object's data is uninitialized.
65 Else the object's data is initialized by copying from DATA. */
66 Lisp_Object
67 make_opaque (size_t size, CONST void *data)
68 {
69 Lisp_Opaque *p = (Lisp_Opaque *)
70 alloc_lcrecord (offsetof (Lisp_Opaque, data) + size, &lrecord_opaque);
71 p->size = size;
72
73 if (data == OPAQUE_CLEAR)
74 memset (p->data, '\0', size);
75 else if (data == OPAQUE_UNINIT)
76 DO_NOTHING;
77 else
78 memcpy (p->data, data, size);
79
80 {
81 Lisp_Object val;
82 XSETOPAQUE (val, p);
83 return val;
84 }
85 }
86
87 /* This will not work correctly for opaques with subobjects! */
88
89 static int
90 equal_opaque (Lisp_Object obj1, Lisp_Object obj2, int depth)
91 {
92 size_t size;
93 return ((size = XOPAQUE_SIZE (obj1)) == XOPAQUE_SIZE (obj2) &&
94 !memcmp (XOPAQUE_DATA (obj1), XOPAQUE_DATA (obj2), size));
95 }
96
97 /* This will not work correctly for opaques with subobjects! */
98
99 static unsigned long
100 hash_opaque (Lisp_Object obj, int depth)
101 {
102 if (XOPAQUE_SIZE (obj) == sizeof (unsigned long))
103 return *((unsigned long *) XOPAQUE_DATA (obj));
104 else
105 return memory_hash (XOPAQUE_DATA (obj), XOPAQUE_SIZE (obj));
106 }
107
108 static const struct lrecord_description opaque_description[] = {
109 { XD_END }
110 };
111
112 DEFINE_LRECORD_SEQUENCE_IMPLEMENTATION ("opaque", opaque,
113 0, print_opaque, 0,
114 equal_opaque, hash_opaque,
115 opaque_description,
116 sizeof_opaque, Lisp_Opaque);
117
118 /* stuff to handle opaque pointers */
119
120 /* Should never, ever be called. (except by an external debugger) */
121 static void
122 print_opaque_ptr (Lisp_Object obj, Lisp_Object printcharfun, int escapeflag)
123 {
124 CONST Lisp_Opaque_Ptr *p = XOPAQUE_PTR (obj);
125 char buf[200];
126
127 sprintf (buf, "#<INTERNAL OBJECT (XEmacs bug?) (opaque_ptr, adr=0x%lx) 0x%lx>",
128 (long)(p->ptr), (unsigned long) p);
129 write_c_string (buf, printcharfun);
130 }
131
132 static int
133 equal_opaque_ptr (Lisp_Object obj1, Lisp_Object obj2, int depth)
134 {
135 return (XOPAQUE_PTR (obj1)->ptr == XOPAQUE_PTR (obj2)->ptr);
136 }
137
138 static unsigned long
139 hash_opaque_ptr (Lisp_Object obj, int depth)
140 {
141 return (unsigned long) XOPAQUE_PTR (obj)->ptr;
142 }
143
144 DEFINE_LRECORD_IMPLEMENTATION ("opaque_ptr", opaque_ptr,
145 0, print_opaque_ptr, 0,
146 equal_opaque_ptr, hash_opaque_ptr, 0,
147 Lisp_Opaque_Ptr);
148
149 Lisp_Object
150 make_opaque_ptr (void *val)
151 {
152 Lisp_Object res = allocate_managed_lcrecord(Vopaque_ptr_free_list);
153 set_opaque_ptr (res, val);
154 return res;
155 }
156
157 /* Be very very careful with this. Same admonitions as with
158 free_cons() apply. */
159
160 void
161 free_opaque_ptr (Lisp_Object ptr)
162 {
163 free_managed_lcrecord (Vopaque_ptr_free_list, ptr);
164 }
165
166 void
167 reinit_opaque_once_early (void)
168 {
169 Vopaque_ptr_free_list = make_lcrecord_list (sizeof (Lisp_Opaque_Ptr), &lrecord_opaque_ptr);
170 staticpro_nodump (&Vopaque_ptr_free_list);
171 }
172
173 void
174 init_opaque_once_early (void)
175 {
176 reinit_opaque_once_early ();
177 }