/* vasprintf and asprintf with out-of-memory checking.
- Copyright (C) 1999, 2002-2004 Free Software Foundation, Inc.
+ Copyright (C) 1999, 2002-2004, 2006 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#include "xvasprintf.h"
#include <errno.h>
+#include <limits.h>
+#include <string.h>
#include "vasprintf.h"
#include "xalloc.h"
+/* Checked size_t computations. */
+#include "xsize.h"
+
+/* Some systems, like OSF/1 4.0 and Woe32, don't have EOVERFLOW. */
+#ifndef EOVERFLOW
+# define EOVERFLOW E2BIG
+#endif
+
+static inline char *
+xstrcat (size_t argcount, va_list args)
+{
+ char *result;
+ va_list ap;
+ size_t totalsize;
+ size_t i;
+ char *p;
+
+ /* Determine the total size. */
+ totalsize = 0;
+ va_copy (ap, args);
+ for (i = argcount; i > 0; i--)
+ {
+ const char *next = va_arg (ap, const char *);
+ totalsize = xsum (totalsize, strlen (next));
+ }
+ va_end (ap);
+
+ /* Test for overflow in the summing pass above or in (totalsize + 1) below.
+ Also, don't return a string longer than INT_MAX, for consistency with
+ vasprintf(). */
+ if (totalsize == SIZE_MAX || totalsize > INT_MAX)
+ {
+ errno = EOVERFLOW;
+ return NULL;
+ }
+
+ /* Allocate and fill the result string. */
+ result = (char *) xmalloc (totalsize + 1);
+ p = result;
+ for (i = argcount; i > 0; i--)
+ {
+ const char *next = va_arg (args, const char *);
+ size_t len = strlen (next);
+ memcpy (p, next, len);
+ p += len;
+ }
+ *p = '\0';
+
+ return result;
+}
+
char *
xvasprintf (const char *format, va_list args)
{
char *result;
+ /* Recognize the special case format = "%s...%s". It is a frequently used
+ idiom for string concatenation and needs to be fast. We don't want to
+ have a separate function xstrcat() for this purpose. */
+ {
+ size_t argcount = 0;
+ const char *f;
+
+ for (f = format;;)
+ {
+ if (*f == '\0')
+ /* Recognized the special case of string concatenation. */
+ return xstrcat (argcount, args);
+ if (*f != '%')
+ break;
+ f++;
+ if (*f != 's')
+ break;
+ f++;
+ argcount++;
+ }
+ }
+
if (vasprintf (&result, format, args) < 0)
{
if (errno == ENOMEM)