1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
23 /* All Rights Reserved */
24
25
26 /*
27 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
28 * Use is subject to license terms.
29 */
30
31 #ifndef _SYS_VA_IMPL_H
32 #define _SYS_VA_IMPL_H
33
34 /*
35 * An application should not include this header directly. Instead it
36 * should be included only through the inclusion of other Sun headers,
37 * specifically <stdarg.h> and <varargs.h>.
38 *
39 * This header serves two purposes.
40 *
41 * First, it provides a common set of definitions that implementations
42 * of the various standards for variable argument lists may use. These
43 * various standards are implemented in <varargs.h>, <stdarg.h>,
44 * <iso/stdarg_iso.h>, <iso/stdarg_c99.h>, and <sys/varargs.h>.
45 *
46 * Second, it provides varying implementations of the common definitions,
47 * depending upon the compiler.
48 */
49
50 /*
51 * The common definitions exported by this header or compilers using
52 * this header are:
53 *
54 * the macro __va_start(list, name) starting the list iteration
55 * the macro __va_arg(list, type) getting the current arg and iterating
56 * the macro __va_copy(to, from) to bookmark the list iteration
57 * the macro __va_end(list) to end the iteration
58 *
59 * In addition, the following are exported via inclusion of <sys/va_list.h>:
60 *
61 * the identifier __builtin_va_alist for the variable list pseudo parameter
62 * the type __va_alist_type for the variable list pseudo parameter
63 * the type __va_list defining the type of the variable list iterator
64 */
65
66 /*
67 * This header uses feature macros (e.g. __BUILTIN_VA_ARG_INCR and
68 * __BUILTIN_VA_STRUCT), compiler macros (e.g. __GNUC__), and processor
69 * macros (e.g. __sparc) to determine the protocol appropriate to the
70 * current compilation. It is intended that the compilation system
71 * define the feature, processor, and compiler macros, not the user of
72 * the system.
73 */
74
75 /*
76 * Many compilation systems depend upon the use of special functions
77 * built into the the compilation system to handle variable argument
78 * lists. These built-in symbols may include one or more of the
79 * following:
80 *
81 * __builtin_va_alist
82 * __builtin_va_start
83 * __builtin_va_arg_incr
84 * __builtin_stdarg_start
85 * __builtin_va_end
86 * __builtin_va_arg
87 * __builtin_va_copy
88 */
89
90 /*
91 * The following are defined in <sys/va_list.h>:
92 *
93 * __va_alist_type
94 * __va_void()
95 * __va_ptr_base
96 * ISA definitions via inclusion of <sys/isa_defs.h>
97 *
98 * Inclusion of this header also makes visible the symbols in <sys/va_list.h>.
99 * This header is included in <varargs.h>, <sys/varargs.h> and in <stdarg.h>
100 * via inclusion of <iso/stdarg_iso.h>.
101 */
102
103 #include <sys/va_list.h>
104
105 #ifdef __cplusplus
106 extern "C" {
107 #endif
108
109 #if defined(__lint) /* ---------------------------------------- protocol */
110
111 #define __va_start(list, name) ((list) = (__va_list)&name)
112 #define __va_arg(list, type) ((type *)(list))[0]
113 #define __va_copy(to, from) __va_void(((to) = (from)))
114 /*ARGSUSED*/
115 static void __va_end(__va_list list) { __va_end(list); }
116
117 #elif defined(__BUILTIN_VA_STRUCT) /* ------------------------ protocol */
118
119 /* ISA __va_list structures defined in <sys/va_list.h> */
120
121 #if defined(__STDC__) /* source language is ISO C or C++ */
122
123 void __builtin_va_start(__va_list, ...);
124 void *__builtin_va_arg_incr(__va_list, ...);
125
126 #else /* source language is K&R C */
127
128 int __builtin_va_start();
129 char *__builtin_va_arg_incr();
130
131 #endif /* source language */
132
133 #define __va_start(list, name) __builtin_va_start(list, 0)
134 #define __va_arg(list, type) \
135 ((type *)__builtin_va_arg_incr(list, (type *)0))[0]
136 #define __va_copy(to, from) __va_void(((to)[0] = (from)[0]))
137 #define __va_end(list) __va_void(0)
138
139 #elif defined(__BUILTIN_VA_ARG_INCR) /* ------------------------ protocol */
140
141 #define __va_start(list, name) \
142 __va_void(((list) = (__va_list)&__builtin_va_alist))
143 #define __va_arg(list, type) \
144 ((type *)__builtin_va_arg_incr((type *)(list)))[0]
145 #define __va_copy(to, from) __va_void(((to) = (from)))
146 #define __va_end(list) __va_void(0)
147
148 #elif defined(__GNUC__) && ((__GNUC__ == 2 && __GNUC_MINOR__ >= 96) || \
149 (__GNUC__ >= 3)) /* ------------------------ protocol */
150 #if (__GNUC__ < 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ < 3))
151 #define __va_start(list, name) __builtin_stdarg_start(list, name)
152 #else
153 #define __va_start(list, name) __builtin_va_start(list, name)
154 #endif
155
156 #define __va_arg(list, type) __builtin_va_arg(list, type)
157 #define __va_end(list) __builtin_va_end(list)
158 #define __va_copy(to, from) __builtin_va_copy(to, from)
159
160 #else /* ----------------------- protocol */
161
162 /*
163 * Because we can not predict the compiler protocol for unknown compilers, we
164 * force an error in order to avoid unpredictable behavior. For versions of
165 * gcc 2.95 and earlier, variable argument lists are handled in gcc specific
166 * stdarg.h and varargs.h headers created via the gcc fixincl utility. In
167 * those cases, the gcc headers would override this header.
168 */
169
170 #error("Unrecognized compiler protocol for variable argument lists")
171
172 #endif /* -------------------------------------------------------- protocol */
173
174 #ifdef __cplusplus
175 }
176 #endif
177
178 #endif /* _SYS_VA_IMPL_H */