1 /* Formatted output to strings.
2 Copyright (C) 1999, 2002, 2006-2007 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify it
5 under the terms of the GNU Lesser General Public License as published
6 by the Free Software Foundation; either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* Some systems, like OSF/1 4.0 and Woe32, don't have EOVERFLOW. */
19 # define EOVERFLOW E2BIG
23 # define SIZE_MAX ((size_t) -1)
27 VSPRINTF (DCHAR_T *buf, const FCHAR_T *format, va_list args)
29 /* Pass an infinite length. But note that *vasnprintf may fail if the buffer
30 argument is larger than INT_MAX (if that fits into a 'size_t' at all).
31 Also note that glibc's iconv fails with E2BIG when we pass a length that
32 is so large that buf + length wraps around, i.e.
33 (uintptr_t) (buf + length) < (uintptr_t) buf. */
37 /* Set length = min (SIZE_MAX, INT_MAX, - (uintptr_t) buf - 1). */
38 length = (SIZE_MAX < INT_MAX ? SIZE_MAX : INT_MAX);
39 if (length > (~ (uintptr_t) buf) / sizeof (DCHAR_T))
40 length = (~ (uintptr_t) buf) / sizeof (DCHAR_T);
42 result = VASNPRINTF (buf, &length, format, args);
46 /* The infinite buffer size guarantees that the result is not malloc()ed. */
49 /* length is near SIZE_MAX. */
61 /* Return the number of resulting units, excluding the trailing NUL. */