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dnl @synopsis AC_FUNC_VSNPRINTF
dnl
dnl @obsoleted Use AC_FUNC_SNPRINTF.
dnl
dnl Check whether there is a reasonably sane vsnprintf() function
dnl installed. "Reasonably sane" in this context means never clobbering
dnl memory beyond the buffer supplied, and having a sensible return
dnl value. It is explicitly allowed not to NUL-terminate the return
dnl value, however.
dnl
dnl @category Obsolete
dnl @author Gaute Strokkenes <gs234@cam.ac.uk>
dnl @version 2005-01-25
dnl @license GPLWithACException
AC_DEFUN([AC_FUNC_VSNPRINTF],
[AC_CACHE_CHECK(for working vsnprintf,
ac_cv_func_vsnprintf,
[AC_TRY_RUN(
[#include <stdio.h>
#include <stdarg.h>
int
doit(char * s, ...)
{
char buffer[32];
va_list args;
int r;
buffer[5] = 'X';
va_start(args, s);
r = vsnprintf(buffer, 5, s, args);
va_end(args);
/* -1 is pre-C99, 7 is C99. */
if (r != -1 && r != 7)
exit(1);
/* We deliberately do not care if the result is NUL-terminated or
not, since this is easy to work around like this. */
buffer[4] = 0;
/* Simple sanity check. */
if (strcmp(buffer, "1234"))
exit(1);
if (buffer[5] != 'X')
exit(1);
exit(0);
}
int
main(void)
{
doit("1234567");
exit(1);
}], ac_cv_func_vsnprintf=yes, ac_cv_func_vsnprintf=no, ac_cv_func_vsnprintf=no)])
dnl Note that the default is to be pessimistic in the case of cross compilation.
dnl If you know that the target has a sensible vsnprintf(), you can get around this
dnl by setting ac_func_vsnprintf to yes, as described in the Autoconf manual.
if test $ac_cv_func_vsnprintf = yes; then
AC_DEFINE(HAVE_WORKING_VSNPRINTF, 1,
[Define if you have a version of the `vsnprintf' function
that honours the size argument and has a proper return value.])
fi
])# AC_FUNC_VSNPRINTF
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