/*

* have_stdvs - try <stdarg.h> to see if it really works with vsnprintf()

*

* Copyright (C) 1999,2014,2018,2021 Landon Curt Noll

*

* Calc is open software; you can redistribute it and/or modify it under

* the terms of the version 2.1 of the GNU Lesser General Public License

* as published by the Free Software Foundation.

*

* Calc is distributed in the hope that it will be useful, but WITHOUT

* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY

* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General

* Public License for more details.

*

* A copy of version 2.1 of the GNU Lesser General Public License is

* distributed with calc under the filename COPYING-LGPL. You should have

* received a copy with calc; if not, write to Free Software Foundation, Inc.

* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

*

* Under source code control: 1995/09/09 22:41:10

* File existed as early as: 1995

*

* chongo <was here> /\oo/\ http://www.isthe.com/chongo/

* Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/

*/

/*

* On some systems that have both <stdarg.h> and <varargs.h>, vsnprintf()

* does not work well under one type of include file.

*

* Some systems (such as UMIPS) have bugs in the <stdarg.h> implementation

* that show up in vsnprintf(), so we may have to try to use snprintf()

* as if it were vsnprintf() and hope for the best.

*

* This program will output #defines and exits 0 if vsnprintf() (or snprintf())

* produces the results that we expect. This program exits 1 if vsnprintf()

* (or snprintf()) produces unexpected results while using the <stdarg.h>

* include file.

*/

#include <stdio.h>

#include "have_unistd.h"

#if defined(HAVE_UNISTD_H)

#include <unistd.h>

#endif

#include <stdarg.h>

#include "have_string.h"

#ifdef HAVE_STRING_H

# include <string.h>

#endif

#include "have_stdlib.h"

#ifdef HAVE_STDLIB_H

# include <stdlib.h>

#endif

#undef VSNPRINTF_SIZE_T

#if defined(FORCE_STDC) || (defined(__STDC__) && __STDC__ != 0) || \

defined(__cplusplus)

# define VSNPRINTF_SIZE_T size_t

#else

# define VSNPRINTF_SIZE_T long

#endif

#include "banned.h" /* include after system header <> includes */

char buf[BUFSIZ+1];

void

try_nthis(char *fmt, VSNPRINTF_SIZE_T size, ...)

{

va_list ap;

va_start(ap, size);

#if !defined(DONT_HAVE_VSNPRINTF)

vsnprintf(buf, size, fmt, ap);

#else

snprintf(buf, size, fmt, ap);

#endif

va_end(ap);

}

int

main(void)

{

/*

* setup

*/

buf[0] = '\0';

/*

* test variable args and vsnprintf/snprintf

*/

try_nthis("@%d:%s:%d@", sizeof(buf)-1, 1, "hello", 5);

if (strcmp(buf, "@1:hello:5@") != 0) {

#if !defined(DONT_HAVE_VSNPRINTF)

/* <stdarg.h> with vsnprintf() didn't work */

#else

/* <stdarg.h> with snprintf() simulating vsnprintf() didn't work */

#endif

exit(1);

}

try_nthis("%s %d%s%d%d %s", sizeof(buf)-1,

"Landon Noll 1st proved that", 2, "^", 23209, -1, "was prime");

if (strcmp(buf,

"Landon Noll 1st proved that 2^23209-1 was prime") != 0) {

#if !defined(DONT_HAVE_VSNPRINTF)

/* <stdarg.h> with vsnprintf() didn't work */

#else

/* <stdarg.h> with snprintf() simulating vsnprintf() didn't work */

#endif

exit(1);

}

/*

* report the result

*/

puts("/* what type of variable args do we have? */");

#if defined(DONT_HAVE_VSNPRINTF)

puts("/*");

puts(" * SIMULATE_STDARG");

puts(" *");

puts(" * WARNING: This type of stdarg makes assumptions "

"about the stack");

puts(" * that may not be true on your system. "

"You may want to");

puts(" * define STDARG (if using ANSI C) or VARARGS.");

puts(" */");

puts("typedef char *va_list;");

puts("#define va_start(ap,parmn) (void)((ap) = (char*)(&(parmn) + 1))");

puts("#define va_end(ap) (void)((ap) = 0)");

puts("#define va_arg(ap, type) \\");

puts(" (((type*)((ap) = ((ap) + sizeof(type))))[-1])");

puts("#define SIMULATE_STDARG "

"/* use std_arg.h to simulate <stdarg.h> */");

#else

puts("#define STDARG /* use <stdarg.h> */");

puts("#include <stdarg.h>");

#endif

puts("\n/* should we use vsnprintf() and vsnprintf()? */");

#if !defined(DONT_HAVE_VSNPRINTF)

puts("#define HAVE_VSNPRINTF /* yes */");

#else

puts("/*");

puts(" * Hack aleart!!!");

puts(" *");

puts(" * Systems that do not have vsnprintf() need something. In some");

puts(" * cases the snprintf function will deal correctly with the");

puts(" * va_alist 4th arg. Same goes for a lack of an vsnprintf()");

puts(" * function. In either case we use the #defines below and");

puts(" * hope for the best!");

puts(" */");

puts("#define vsnprintf snprintf");

puts("#undef HAVE_VSNPRINTF");

#endif

/* exit(0); */

return 0;

}