c_cpp/etc/calc/have_stdvs.c

   1 /*
   2  * have_stdvs - try <stdarg.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_stdvs.c,v 30.2 2013/08/11 08:41:38 chongo Exp $
  22  * @(#) $Source: /usr/local/src/bin/calc/RCS/have_stdvs.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  * On some systems that have both <stdarg.h> and <varargs.h>, vsprintf()
  33  * does not work well under one type of include file.
  34  *
  35  * Some systems (such as UMIPS) have bugs in the <stdarg.h> implementation
  36  * that show up in vsprintf(), so we may have to try to use sprintf()
  37  * as if it were vsprintf() and hope for the best.
  38  *
  39  * This program will output #defines and exits 0 if vsprintf() (or sprintf())
  40  * produces the results that we expect.  This program exits 1 if vsprintf()
  41  * (or sprintf()) produces unexpected results while using the <stdarg.h>
  42  * include file.
  43  */
  44
  45
  46 #include <stdio.h>
  47
  48 #include "have_unistd.h"
  49 #if defined(HAVE_UNISTD_H)
  50 #include <unistd.h>
  51 #endif
  52 #include <stdarg.h>
  53
  54 #include "have_string.h"
  55 #ifdef HAVE_STRING_H
  56 # include <string.h>
  57 #endif
  58
  59 #undef VSPRINTF_SIZE_T
  60 #if defined(FORCE_STDC) || (defined(__STDC__) && __STDC__ != 0) || \
  61     defined(__cplusplus)
  62 # define VSPRINTF_SIZE_T size_t
  63 #else
  64 # define VSPRINTF_SIZE_T long
  65 #endif
  66
  67 char buf[BUFSIZ];
  68
  69
  70 void
  71 try_this(char *fmt, ...)
  72 {
  73         va_list ap;
  74
  75         va_start(ap, fmt);
  76 #if !defined(DONT_HAVE_VSPRINTF)
  77         vsprintf(buf, fmt, ap);
  78 #else
  79         sprintf(buf, fmt, ap);
  80 #endif
  81         va_end(ap);
  82 }
  83
  84
  85 void
  86 try_nthis(char *fmt, VSPRINTF_SIZE_T size, ...)
  87 {
  88         va_list ap;
  89
  90         va_start(ap, fmt);
  91 #if !defined(DONT_HAVE_VSPRINTF)
  92         vsnprintf(buf, size, fmt, ap);
  93 #else
  94         snprintf(buf, size, fmt, ap);
  95 #endif
  96         va_end(ap);
  97 }
  98
  99
 100 int
 101 main(void)
 102 {
 103         /*
 104          * setup
 105          */
 106         buf[0] = '\0';
 107
 108         /*
 109          * test variable args and vsprintf/sprintf
 110          */
 111         try_this("@%d:%s:%d@", 1, "hi", 2);
 112         if (strcmp(buf, "@1:hi:2@") != 0) {
 113 #if !defined(DONT_HAVE_VSPRINTF)
 114             /* <stdarg.h> with vsprintf() didn't work */
 115 #else
 116             /* <stdarg.h> with sprintf() simulating vsprintf() didn't work */
 117 #endif
 118             exit(1);
 119         }
 120         try_this("%s %d%s%d%d %s",
 121             "Landon Noll 1st coproved that", 2, "^", 21701, -1, "was prime");
 122         if (strcmp(buf,
 123                    "Landon Noll 1st coproved that 2^21701-1 was prime") != 0) {
 124 #if !defined(DONT_HAVE_VSPRINTF)
 125             /* <stdarg.h> with vsprintf() didn't work */
 126 #else
 127             /* <stdarg.h> with sprintf() simulating vsprintf() didn't work */
 128 #endif
 129             exit(1);
 130         }
 131
 132         /*
 133          * test variable args and vsnprintf/snprintf
 134          */
 135         try_nthis("@%d:%s:%d@", sizeof(buf)-1, 1, "hello", 5);
 136         if (strcmp(buf, "@1:hello:5@") != 0) {
 137 #if !defined(DONT_HAVE_VSPRINTF)
 138             /* <stdarg.h> with vsnprintf() didn't work */
 139 #else
 140             /* <stdarg.h> with snprintf() simulating vsnprintf() didn't work */
 141 #endif
 142             exit(1);
 143         }
 144         try_nthis("%s %d%s%d%d %s", sizeof(buf)-1,
 145             "Landon Noll 1st proved that", 2, "^", 23209, -1, "was prime");
 146         if (strcmp(buf,
 147                    "Landon Noll 1st proved that 2^23209-1 was prime") != 0) {
 148 #if !defined(DONT_HAVE_VSPRINTF)
 149             /* <stdarg.h> with vsnprintf() didn't work */
 150 #else
 151             /* <stdarg.h> with snprintf() simulating vsnprintf() didn't work */
 152 #endif
 153             exit(1);
 154         }
 155
 156         /*
 157          * report the result
 158          */
 159         puts("/* what type of variable args do we have? */");
 160 #if defined(DONT_HAVE_VSPRINTF)
 161         puts("/*");
 162         puts(" * SIMULATE_STDARG");
 163         puts(" *");
 164         puts(" * WARNING: This type of stdarg makes assumptions "
 165              "about the stack");
 166         puts(" *            that may not be true on your system.  "
 167              "You may want to");
 168         puts(" *            define STDARG (if using ANSI C) or VARARGS.");
 169         puts(" */");
 170         puts("typedef char *va_list;");
 171         puts("#define va_start(ap,parmn) (void)((ap) = (char*)(&(parmn) + 1))");
 172         puts("#define va_end(ap) (void)((ap) = 0)");
 173         puts("#define va_arg(ap, type) \\");
 174         puts("        (((type*)((ap) = ((ap) + sizeof(type))))[-1])");
 175         puts("#define SIMULATE_STDARG "
 176              "/* use std_arg.h to simulate <stdarg.h> */");
 177 #else
 178         puts("#define STDARG /* use <stdarg.h> */");
 179         puts("#include <stdarg.h>");
 180 #endif
 181         puts("\n/* should we use vsprintf() and vsnprintf()? */");
 182 #if !defined(DONT_HAVE_VSPRINTF)
 183         puts("#define HAVE_VSPRINTF /* yes */");
 184 #else
 185         puts("/*");
 186         puts(" * Hack aleart!!!");
 187         puts(" *");
 188         puts(" * Systems that do not have vsprintf() need something.  In some");
 189         puts(" * cases the sprintf function will deal correctly with the");
 190         puts(" * va_alist 3rd arg.  Same gors for a lack of an vsnprintf()");
 191         puts(" * function.  In either case we use the #defines below and");
 192         puts(" * hope for the best!");
 193         puts(" */");
 194         puts("#define vsprintf sprintf");
 195         puts("#define vsnprintf snprintf");
 196         puts("#undef HAVE_VSPRINTF");
 197 #endif
 198         /* exit(0); */
 199         return 0;
 200 }