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/* Formatted output to strings.
Copyright (C) 1999, 2002, 2006-2015 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published
by the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef SIZE_MAX
# define SIZE_MAX ((size_t) -1)
#endif
int
VSPRINTF (DCHAR_T *buf, const FCHAR_T *format, va_list args)
{
/* Pass an infinite length. But note that *vasnprintf may fail if the buffer
argument is larger than INT_MAX (if that fits into a 'size_t' at all).
Also note that glibc's iconv fails with E2BIG when we pass a length that
is so large that buf + length wraps around, i.e.
(uintptr_t) (buf + length) < (uintptr_t) buf. */
size_t length;
DCHAR_T *result;
/* Set length = min (SIZE_MAX, INT_MAX, - (uintptr_t) buf - 1). */
length = (SIZE_MAX < INT_MAX ? SIZE_MAX : INT_MAX);
if (length > (~ (uintptr_t) buf) / sizeof (DCHAR_T))
length = (~ (uintptr_t) buf) / sizeof (DCHAR_T);
result = VASNPRINTF (buf, &length, format, args);
if (result == NULL)
return -1;
/* The infinite buffer size guarantees that the result is not malloc()ed. */
if (result != buf)
{
/* length is near SIZE_MAX. */
free (result);
errno = EOVERFLOW;
return -1;
}
if (length > INT_MAX)
{
errno = EOVERFLOW;
return -1;
}
/* Return the number of resulting units, excluding the trailing NUL. */
return length;
}
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