c_cpp/etc/calc/have_varvs.c

   1 /*
   2  * have_varvs - try <varargs.h> to see if it really works with vsprintf()
   3  *
   4  * Copyright (C) 1999  Landon Curt Noll
   5  *
   6  * Calc is open software; you can redistribute it and/or modify it under
   7  * the terms of the version 2.1 of the GNU Lesser General Public License
   8  * as published by the Free Software Foundation.
   9  *
  10  * Calc is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General
  13  * Public License for more details.
  14  *
  15  * A copy of version 2.1 of the GNU Lesser General Public License is
  16  * distributed with calc under the filename COPYING-LGPL.  You should have
  17  * received a copy with calc; if not, write to Free Software Foundation, Inc.
  18  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19  *
  20  * @(#) $Revision: 30.2 $
  21  * @(#) $Id: have_varvs.c,v 30.2 2013/08/11 08:41:38 chongo Exp $
  22  * @(#) $Source: /usr/local/src/bin/calc/RCS/have_varvs.c,v $
  23  *
  24  * Under source code control:   1995/09/09 22:41:10
  25  * File existed as early as:    1995
  26  *
  27  * chongo <was here> /\oo/\     http://www.isthe.com/chongo/
  28  * Share and enjoy!  :-)        http://www.isthe.com/chongo/tech/comp/calc/
  29  */
  30
  31 /*
  32  * Some systems have bugs in the <varargs.h> implementation that show up in
  33  * vsprintf(), so we may have to try to use sprintf() as if it were vsprintf()
  34  * and hope for the best.
  35  *
  36  * This program will output #defines and exits 0 if vsprintf() (or sprintf())
  37  * produces the results that we expect.  This program exits 1 if vsprintf()
  38  * (or sprintf()) produces unexpected results while using the <stdarg.h>
  39  * include file.
  40  */
  41
  42
  43 #include <stdio.h>
  44
  45 #include "have_unistd.h"
  46 #if defined(HAVE_UNISTD_H)
  47 #include <unistd.h>
  48 #endif
  49
  50 #include "have_string.h"
  51 #ifdef HAVE_STRING_H
  52 # include <string.h>
  53 #endif
  54
  55 #undef VSPRINTF_SIZE_T
  56 #if defined(FORCE_STDC) || (defined(__STDC__) && __STDC__ != 0) || \
  57     defined(__cplusplus)
  58 # define VSPRINTF_SIZE_T size_t
  59 #else
  60 # define VSPRINTF_SIZE_T long
  61 #endif
  62
  63 char buf[BUFSIZ];
  64
  65 #if !defined(STDARG) && !defined(SIMULATE_STDARG)
  66 #include <varargs.h>
  67
  68 void
  69 try_this(char *fmt, ...)
  70 {
  71     va_list ap;
  72
  73     va_start(ap);
  74
  75 #if !defined(DONT_HAVE_VSPRINTF)
  76     vsprintf(buf, fmt, ap);
  77 #else
  78     sprintf(buf, fmt, ap);
  79 #endif
  80
  81     va_end(ap);
  82 }
  83
  84 void
  85 try_nthis(char *fmt, VSPRINTF_SIZE_T size, ...)
  86 {
  87     va_list ap;
  88
  89     va_start(ap);
  90
  91 #if !defined(DONT_HAVE_VSPRINTF)
  92     vsnprintf(buf, size, fmt, ap);
  93 #else
  94     snprintf(buf, size, fmt, ap);
  95 #endif
  96
  97     va_end(ap);
  98 }
  99
 100 #else
 101
 102 void
 103 try_this(char *a, int b, char *c, int d)
 104 {
 105     return;
 106 }
 107
 108 void
 109 try_nthis(char *a, VSPRINTF_SIZE_T size, int b, char *c, int d)
 110 {
 111     return;
 112 }
 113
 114 #endif
 115
 116
 117 int
 118 main(void)
 119 {
 120         /*
 121          * setup
 122          */
 123         buf[0] = '\0';
 124
 125         /*
 126          * test variable args and vsprintf/sprintf
 127          */
 128         try_this("@%d:%s:%d@", 1, "hi", 2);
 129         if (strcmp(buf, "@1:hi:2@") != 0) {
 130 #if !defined(DONT_HAVE_VSPRINTF)
 131             /* <varargs.h> with vsprintf() didn't work */
 132 #else
 133             /* <varargs.h> with sprintf() simulating vsprintf() didn't work */
 134 #endif
 135             exit(1);
 136         }
 137         try_this("%s %d%s%d%d %s",
 138             "Landon Noll 1st proved that", 2, "^", 23209, -1, "was prime");
 139         if (strcmp(buf,
 140                    "Landon Noll 1st proved that 2^23209-1 was prime") != 0) {
 141 #if !defined(DONT_HAVE_VSPRINTF)
 142             /* <varargs.h> with vsprintf() didn't work */
 143 #else
 144             /* <varargs.h> with sprintf() simulating vsprintf() didn't work */
 145 #endif
 146             exit(1);
 147         }
 148
 149         /*
 150          * test variable args and vsnprintf/snprintf
 151          */
 152         try_nthis("@%d:%s:%d@", sizeof(buf)-1, 1, "hello", 5);
 153         if (strcmp(buf, "@1:hello:5@") != 0) {
 154 #if !defined(DONT_HAVE_VSPRINTF)
 155             /* <varargs.h> with vsnprintf() didn't work */
 156 #else
 157             /* <varargs.h> with snprintf() simulating vsnprintf() didn't work */
 158 #endif
 159             exit(1);
 160         }
 161         try_nthis("%s %d%s%d%d %s", sizeof(buf)-1,
 162             "Landon Noll 1st proved that", 2, "^", 23209, -1, "was prime");
 163         if (strcmp(buf,
 164                    "Landon Noll 1st proved that 2^23209-1 was prime") != 0) {
 165 #if !defined(DONT_HAVE_VSPRINTF)
 166             /* <varargs.h> with vsnprintf() didn't work */
 167 #else
 168             /* <varargs.h> with snprintf() simulating vsnprintf() didn't work */
 169 #endif
 170             exit(1);
 171         }
 172
 173         /*
 174          * report the result
 175          */
 176         puts("/* what type of variable args do we have? */");
 177         puts("#define VARARGS /* use <varargs.h> */");
 178         puts("#include <varargs.h>");
 179         puts("\n/* should we use vsprintf() and vsnprintf()? */");
 180 #if !defined(DONT_HAVE_VSPRINTF)
 181         puts("#define HAVE_VSPRINTF /* yes */");
 182 #else
 183         puts("/*");
 184         puts(" * Hack aleart!!!");
 185         puts(" *");
 186         puts(" * Systems that do not have vsprintf() need something.  In some");
 187         puts(" * cases the sprintf function will deal correctly with the");
 188         puts(" * va_alist 3rd arg.  Same gors for a lack of an vsnprintf()");
 189         puts(" * function.  In either case we use the #defines below and");
 190         puts(" * hope for the best!");
 191         puts(" */");
 192         puts("#define vsprintf sprintf");
 193         puts("#define vsnprintf snprintf");
 194         puts("#undef HAVE_VSPRINTF");
 195 #endif
 196         /* exit(0); */
 197         return 0;
 198 }