summaryrefslogtreecommitdiff
path: root/lib/unistdio/u-vsprintf.h
diff options
context:
space:
mode:
Diffstat (limited to 'lib/unistdio/u-vsprintf.h')
-rw-r--r--lib/unistdio/u-vsprintf.h58
1 files changed, 58 insertions, 0 deletions
diff --git a/lib/unistdio/u-vsprintf.h b/lib/unistdio/u-vsprintf.h
new file mode 100644
index 00000000..36ebd9fa
--- /dev/null
+++ b/lib/unistdio/u-vsprintf.h
@@ -0,0 +1,58 @@
+/* Formatted output to strings.
+ Copyright (C) 1999, 2002, 2006-2008 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;
+}