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-rw-r--r--gl/lib/xvasprintf.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/gl/lib/xvasprintf.c b/gl/lib/xvasprintf.c
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+++ b/gl/lib/xvasprintf.c
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+/* vasprintf and asprintf with out-of-memory checking.
+ Copyright (C) 1999, 2002-2004, 2006-2022 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
+ 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include "xvasprintf.h"
+
+#include <errno.h>
+#include <limits.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "xalloc.h"
+
+/* Checked size_t computations. */
+#include "xsize.h"
+
+static 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)
+ xalloc_die ();
+ return NULL;
+ }
+
+ return result;
+}