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varargs.h
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1 /* @(#)varargs.h 1.8 14/01/06 Copyright 1998-2014 J. Schilling */
2 /*
3  * Generic header for users of var args ...
4  *
5  * Includes a default definition for va_copy()
6  * and some magic know how about the SVr4 Power PC var args ABI
7  * to create a __va_arg_list() macro.
8  *
9  * The __va_arg_list() macro is needed to fetch a va_list type argument
10  * from a va_list. This is needed to implement a recursive "%r" printf.
11  *
12  * Copyright (c) 1998-2014 J. Schilling
13  */
14 /*
15  * The contents of this file are subject to the terms of the
16  * Common Development and Distribution License, Version 1.0 only
17  * (the "License"). You may not use this file except in compliance
18  * with the License.
19  *
20  * See the file CDDL.Schily.txt in this distribution for details.
21  * A copy of the CDDL is also available via the Internet at
22  * http://www.opensource.org/licenses/cddl1.txt
23  *
24  * When distributing Covered Code, include this CDDL HEADER in each
25  * file and include the License file CDDL.Schily.txt from this distribution.
26  */
27 
28 #ifndef _SCHILY_VARARGS_H
29 #define _SCHILY_VARARGS_H
30 
31 #ifndef _SCHILY_MCONFIG_H
32 #include <schily/mconfig.h>
33 #endif
34 
35 #ifdef __cplusplus
36 extern "C" {
37 #endif
38 
39 #ifdef PROTOTYPES
40 /*
41  * For ANSI C-compilers prefer stdarg.h
42  */
43 # ifdef HAVE_STDARG_H
44 # ifndef _INCL_STDARG_H
45 # include <stdarg.h>
46 # define _INCL_STDARG_H
47 # endif
48 # else
49 # ifndef _INCL_VARARGS_H
50 # include <varargs.h>
51 # define _INCL_VARARGS_H
52 # endif
53 # endif
54 #else
55 /*
56  * For K&R C-compilers prefer varargs.h
57  */
58 # ifdef HAVE_VARARGS_H
59 # ifndef _INCL_VARARGS_H
60 # include <varargs.h>
61 # define _INCL_VARARGS_H
62 # endif
63 # else
64 # ifndef _INCL_STDARG_H
65 # include <stdarg.h>
66 # define _INCL_STDARG_H
67 # endif
68 # endif
69 #endif
70 
71 #if (defined(__linux__) || defined(__linux) || defined(sun)) && \
72  (defined(__ppc) || defined(__PPC) || \
73  defined(powerpc) || defined(__powerpc__))
74 
75 # ifndef VA_LIST_IS_ARRAY
76 # define VA_LIST_IS_ARRAY
77 # endif
78 #endif
79 
80 
81 /*
82  * __va_copy() is used by GCC 2.8 or newer until va_copy() becomes
83  * a final ISO standard.
84  */
85 #if !defined(va_copy) && !defined(HAVE_VA_COPY)
86 # if defined(__va_copy)
87 # define va_copy(to, from) __va_copy(to, from)
88 # endif
89 #endif
90 
91 /*
92  * va_copy() is a Solaris extension to provide a portable way to perform a
93  * variable argument list "bookmarking" function.
94  * If it is not available via stdarg.h, use a simple assignement for backward
95  * compatibility.
96  */
97 #if !defined(va_copy) && !defined(HAVE_VA_COPY)
98 #ifdef VA_LIST_IS_ARRAY
99 # define va_copy(to, from) ((to)[0] = (from)[0])
100 #else
101 # define va_copy(to, from) ((to) = (from))
102 #endif
103 #endif
104 
105 /*
106  * I don't know any portable way to get an arbitrary
107  * C object from a var arg list so I use a
108  * system-specific routine __va_arg_list() that knows
109  * if 'va_list' is an array. You will not be able to
110  * assign the value of __va_arg_list() but it works
111  * to be used as an argument of a function.
112  * It is a requirement for recursive printf to be able
113  * to use this function argument. If your system
114  * defines va_list to be an array you need to know this
115  * via autoconf or another mechanism.
116  * It would be nice to have something like
117  * __va_arg_list() in stdarg.h
118  */
119 
120 #ifdef VA_LIST_IS_ARRAY
121 # define __va_arg_list(list) va_arg(list, void *)
122 #else
123 # define __va_arg_list(list) va_arg(list, va_list)
124 #endif
125 
126 /*
127  * This structure allows to work around the C limitation that a variable of
128  * type array cannot appear at the left side of an assignement operator.
129  * By putting va_list inside a struture, the assignement will work even in case
130  * that va_list is an array2.
131  */
132 typedef struct {
134 } va_lists_t;
135 
136 #ifdef __cplusplus
137 }
138 #endif
139 
140 #endif /* _SCHILY_VARARGS_H */
char * va_list
Definition: acmsvcex.h:78
va_list ap
Definition: varargs.h:133