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 2014 Garrett D'Amore <garrett@damore.org>
28 *
29 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
30 * Use is subject to license terms.
31 */
32
33 #ifndef _SYS_VA_IMPL_H
34 #define _SYS_VA_IMPL_H
35
36 /*
37 * An application should not include this header directly. Instead it
38 * should be included only through the inclusion of other Sun headers,
39 * specifically <stdarg.h> and <varargs.h>.
40 *
41 * This header serves two purposes.
42 *
43 * First, it provides a common set of definitions that implementations
44 * of the various standards for variable argument lists may use. These
45 * various standards are implemented in <varargs.h>, <stdarg.h>,
46 * <iso/stdarg_iso.h>, <iso/stdarg_c99.h>, and <sys/varargs.h>.
47 *
48 * Second, it provides varying implementations of the common definitions,
49 * depending upon the compiler.
50 */
51
52 /*
53 * The common definitions exported by this header or compilers using
54 * this header are:
55 *
56 * the macro __va_start(list, name) starting the list iteration
57 * the macro __va_arg(list, type) getting the current arg and iterating
58 * the macro __va_copy(to, from) to bookmark the list iteration
59 * the macro __va_end(list) to end the iteration
60 *
61 * In addition, the following are exported via inclusion of <sys/va_list.h>:
62 *
63 * the identifier __builtin_va_alist for the variable list pseudo parameter
64 * the type __va_alist_type for the variable list pseudo parameter
65 * the type __va_list defining the type of the variable list iterator
66 */
67
68 /*
69 * This header uses feature macros (e.g. __BUILTIN_VA_ARG_INCR and
70 * __BUILTIN_VA_STRUCT), compiler macros (e.g. __GNUC__), and processor
71 * macros (e.g. __sparc) to determine the protocol appropriate to the
72 * current compilation. It is intended that the compilation system
73 * define the feature, processor, and compiler macros, not the user of
74 * the system.
75 */
76
77 /*
78 * Many compilation systems depend upon the use of special functions
79 * built into the the compilation system to handle variable argument
80 * lists. These built-in symbols may include one or more of the
81 * following:
82 *
83 * __builtin_va_alist
84 * __builtin_va_start
85 * __builtin_va_arg_incr
86 * __builtin_stdarg_start
87 * __builtin_va_end
88 * __builtin_va_arg
89 * __builtin_va_copy
90 */
91
92 /*
93 * The following are defined in <sys/va_list.h>:
94 *
95 * __va_alist_type
96 * __va_void()
97 * __va_ptr_base
98 * ISA definitions via inclusion of <sys/isa_defs.h>
99 *
100 * Inclusion of this header also makes visible the symbols in <sys/va_list.h>.
101 * This header is included in <varargs.h>, <sys/varargs.h> and in <stdarg.h>
102 * via inclusion of <iso/stdarg_iso.h>.
103 */
104
105 #include <sys/va_list.h>
106
107 #ifdef __cplusplus
108 extern "C" {
109 #endif
110
111 #if defined(__lint) /* ---------------------------------------- protocol */
112
113 #define __va_start(list, name) ((list) = (__va_list)&name)
114 #define __va_arg(list, type) ((type *)(list))[0]
115 #define __va_copy(to, from) __va_void(((to) = (from)))
116 /*ARGSUSED*/
117 static void __va_end(__va_list list) { __va_end(list); }
118
119 #elif defined(__BUILTIN_VA_STRUCT) /* ------------------------ protocol */
120
121 /* ISA __va_list structures defined in <sys/va_list.h> */
122
123 void __builtin_va_start(__va_list, ...);
124 void *__builtin_va_arg_incr(__va_list, ...);
125
126 #define __va_start(list, name) __builtin_va_start(list, 0)
127 #define __va_arg(list, type) \
128 ((type *)__builtin_va_arg_incr(list, (type *)0))[0]
129 #define __va_copy(to, from) __va_void(((to)[0] = (from)[0]))
130 #define __va_end(list) __va_void(0)
131
132 #elif defined(__BUILTIN_VA_ARG_INCR) /* ------------------------ protocol */
133
134 #define __va_start(list, name) \
135 __va_void(((list) = (__va_list)&__builtin_va_alist))
136 #define __va_arg(list, type) \
137 ((type *)__builtin_va_arg_incr((type *)(list)))[0]
138 #define __va_copy(to, from) __va_void(((to) = (from)))
139 #define __va_end(list) __va_void(0)
140
141 #elif defined(__GNUC__) && ((__GNUC__ == 2 && __GNUC_MINOR__ >= 96) || \
142 (__GNUC__ >= 3)) /* ------------------------ protocol */
143 #if (__GNUC__ < 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ < 3))
144 #define __va_start(list, name) __builtin_stdarg_start(list, name)
145 #else
146 #define __va_start(list, name) __builtin_va_start(list, name)
147 #endif
148
149 #define __va_arg(list, type) __builtin_va_arg(list, type)
150 #define __va_end(list) __builtin_va_end(list)
151 #define __va_copy(to, from) __builtin_va_copy(to, from)
152
153 #else /* ----------------------- protocol */
154
155 /*
156 * Because we can not predict the compiler protocol for unknown compilers, we
157 * force an error in order to avoid unpredictable behavior. For versions of
158 * gcc 2.95 and earlier, variable argument lists are handled in gcc specific
159 * stdarg.h and varargs.h headers created via the gcc fixincl utility. In
160 * those cases, the gcc headers would override this header.
161 */
162
163 #error("Unrecognized compiler protocol for variable argument lists")
164
165 #endif /* -------------------------------------------------------- protocol */
166
167 #ifdef __cplusplus
168 }
169 #endif
170
171 #endif /* _SYS_VA_IMPL_H */