gcc/libiberty/vprintf-support.c

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/* Estimate the length of the string generated by a vprintf-like
function. Used by vasprintf and xvasprintf.
Copyright (C) 1994-2018 Free Software Foundation, Inc.
This file is part of the libiberty library.
Libiberty is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
Libiberty 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with libiberty; see the file COPYING.LIB. If not, write
to the Free Software Foundation, Inc., 51 Franklin Street - Fifth
Floor, Boston, MA 02110-1301, USA. */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <ansidecl.h>
#include <stdarg.h>
#if !defined (va_copy) && defined (__va_copy)
# define va_copy(d,s) __va_copy((d),(s))
#endif
#include <stdio.h>
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#else
extern unsigned long strtoul ();
#endif
#include "libiberty.h"
int
libiberty_vprintf_buffer_size (const char *format, va_list args)
{
const char *p = format;
/* Add one to make sure that it is never zero, which might cause malloc
to return NULL. */
int total_width = strlen (format) + 1;
va_list ap;
#ifdef va_copy
va_copy (ap, args);
#else
memcpy ((PTR) &ap, (PTR) &args, sizeof (va_list));
#endif
while (*p != '\0')
{
if (*p++ == '%')
{
while (strchr ("-+ #0", *p))
++p;
if (*p == '*')
{
++p;
total_width += abs (va_arg (ap, int));
}
else
total_width += strtoul (p, (char **) &p, 10);
if (*p == '.')
{
++p;
if (*p == '*')
{
++p;
total_width += abs (va_arg (ap, int));
}
else
total_width += strtoul (p, (char **) &p, 10);
}
while (strchr ("hlL", *p))
++p;
/* Should be big enough for any format specifier except %s and floats. */
total_width += 30;
switch (*p)
{
case 'd':
case 'i':
case 'o':
case 'u':
case 'x':
case 'X':
case 'c':
(void) va_arg (ap, int);
break;
case 'f':
case 'e':
case 'E':
case 'g':
case 'G':
(void) va_arg (ap, double);
/* Since an ieee double can have an exponent of 307, we'll
make the buffer wide enough to cover the gross case. */
total_width += 307;
break;
case 's':
total_width += strlen (va_arg (ap, char *));
break;
case 'p':
case 'n':
(void) va_arg (ap, char *);
break;
}
p++;
}
}
#ifdef va_copy
va_end (ap);
#endif
return total_width;
}