1115705Sobrien/* Checking gets.
2115705Sobrien   Copyright (C) 2005 Free Software Foundation, Inc.
328762Sbde
455626SbdeThis file is part of GCC.
555062Smarcel
6102964SbdeGCC is free software; you can redistribute it and/or modify it under
728762Sbdethe terms of the GNU General Public License as published by the Free
814331SpeterSoftware Foundation; either version 2, or (at your option) any later
914331Speterversion.
1083221Smarcel
1183221SmarcelIn addition to the permissions in the GNU General Public License, the
1283221SmarcelFree Software Foundation gives you unlimited permission to link the
1383221Smarcelcompiled version of this file into combinations with other programs,
1483221Smarceland to distribute those combinations without any restriction coming
1583221Smarcelfrom the use of this file.  (The General Public License restrictions
16182849Skibdo apply in other respects; for example, they cover modification of
17the file, and distribution when not linked into a combine
18executable.)
19
20GCC is distributed in the hope that it will be useful, but WITHOUT ANY
21WARRANTY; without even the implied warranty of MERCHANTABILITY or
22FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
23for more details.
24
25You should have received a copy of the GNU General Public License
26along with GCC; see the file COPYING.  If not, write to the Free
27Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
2802110-1301, USA.  */
29
30/* As a special exception, if you link this library with files compiled with
31   GCC to produce an executable, this does not cause the resulting executable
32   to be covered by the GNU General Public License. This exception does not
33   however invalidate any other reasons why the executable file might be
34   covered by the GNU General Public License.  */
35
36#include "config.h"
37#include <ssp/ssp.h>
38#include <stdarg.h>
39#ifdef HAVE_STDLIB_H
40# include <stdlib.h>
41#endif
42#ifdef HAVE_ALLOCA_H
43# include <alloca.h>
44#endif
45#ifdef HAVE_LIMITS_H
46# include <limits.h>
47#endif
48#ifdef HAVE_STDIO_H
49# include <stdio.h>
50#endif
51#ifdef HAVE_STRING_H
52# include <string.h>
53#endif
54
55extern void __chk_fail (void) __attribute__((__noreturn__));
56
57char *
58__gets_chk (char *s, size_t slen)
59{
60  char *ret, *buf;
61
62  if (slen >= (size_t) INT_MAX)
63    return gets (s);
64
65  if (slen <= 8192)
66    buf = alloca (slen + 1);
67  else
68    buf = malloc (slen + 1);
69  if (buf == NULL)
70    return gets (s);
71
72  ret = fgets (buf, (int) (slen + 1), stdin);
73  if (ret != NULL)
74    {
75      size_t len = strlen (buf);
76      if (len > 0 && buf[len - 1] == '\n')
77        --len;
78      if (len == slen)
79        __chk_fail ();
80      memcpy (s, buf, len);
81      s[len] = '\0';
82      ret = s;
83    }
84
85  if (slen > 8192)
86    free (buf);
87  return ret;
88}
89