X-Git-Url: https://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fxvasprintf.c;h=bd683627ef410d0b02a099043b238018e6b8949a;hb=6684d992bfedd21bf8dea1fbb52392c1d7c8159b;hp=beea45ac13c0dbf8e9fc5c5369b15457f6b9e2b1;hpb=6abae3924eb57e5eea340d55c10c7eab507b556c;p=gnulib.git

diff --git a/lib/xvasprintf.c b/lib/xvasprintf.c
index beea45ac1..bd683627e 100644
--- a/lib/xvasprintf.c
+++ b/lib/xvasprintf.c
@@ -1,5 +1,5 @@
 /* vasprintf and asprintf with out-of-memory checking.
-   Copyright (C) 1999, 2002-2004 Free Software Foundation, Inc.
+   Copyright (C) 1999, 2002-2004, 2006, 2007 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
@@ -13,25 +13,98 @@
 
    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation,
-   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
 
 /* Specification.  */
 #include "xvasprintf.h"
 
 #include <errno.h>
+#include <limits.h>
+#include <string.h>
+#include <stdio.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 = XNMALLOC (totalsize + 1, char);
+  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)