debug/obprintf_chk.c

   1 /* Print output of stream to given obstack.
   2    Copyright (C) 1996,1997,1999,2000,2001,2002,2003,2004,2005,2006,2008
   3         Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   6
   7    The GNU C Library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public
   9    License as published by the Free Software Foundation; either
  10    version 2.1 of the License, or (at your option) any later version.
  11
  12    The GNU C Library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with the GNU C Library; if not, see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21
  22 #include <stdlib.h>
  23 #include <libioP.h>
  24 #include "../libio/strfile.h"
  25 #include <assert.h>
  26 #include <string.h>
  27 #include <errno.h>
  28 #include <obstack.h>
  29 #include <stdarg.h>
  30 #include <stdio_ext.h>
  31
  32
  33 struct _IO_obstack_file
  34 {
  35   struct _IO_FILE_plus file;
  36   struct obstack *obstack;
  37 };
  38
  39 extern const struct _IO_jump_t _IO_obstack_jumps attribute_hidden;
  40
  41 int
  42 __obstack_vprintf_chk (struct obstack *obstack, int flags, const char *format,
  43                        va_list args)
  44 {
  45   struct obstack_FILE
  46     {
  47       struct _IO_obstack_file ofile;
  48     } new_f;
  49   int result;
  50   int size;
  51   int room;
  52
  53 #ifdef _IO_MTSAFE_IO
  54   new_f.ofile.file.file._lock = NULL;
  55 #endif
  56
  57   _IO_no_init (&new_f.ofile.file.file, _IO_USER_LOCK, -1, NULL, NULL);
  58   _IO_JUMPS (&new_f.ofile.file) = &_IO_obstack_jumps;
  59   room = obstack_room (obstack);
  60   size = obstack_object_size (obstack) + room;
  61   if (size == 0)
  62     {
  63       /* We have to handle the allocation a bit different since the
  64          `_IO_str_init_static' function would handle a size of zero
  65          different from what we expect.  */
  66
  67       /* Get more memory.  */
  68       obstack_make_room (obstack, 64);
  69
  70       /* Recompute how much room we have.  */
  71       room = obstack_room (obstack);
  72       size = room;
  73
  74       assert (size != 0);
  75     }
  76
  77   _IO_str_init_static_internal ((struct _IO_strfile_ *) &new_f.ofile,
  78                                 obstack_base (obstack),
  79                                 size, obstack_next_free (obstack));
  80   /* Now allocate the rest of the current chunk.  */
  81   assert (size == (new_f.ofile.file.file._IO_write_end
  82                    - new_f.ofile.file.file._IO_write_base));
  83   assert (new_f.ofile.file.file._IO_write_ptr
  84           == (new_f.ofile.file.file._IO_write_base
  85               + obstack_object_size (obstack)));
  86   obstack_blank_fast (obstack, room);
  87
  88   new_f.ofile.obstack = obstack;
  89
  90   /* For flags > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
  91      can only come from read-only format strings.  */
  92   if (flags > 0)
  93     new_f.ofile.file.file._flags2 |= _IO_FLAGS2_FORTIFY;
  94
  95   result = INTUSE(_IO_vfprintf) (&new_f.ofile.file.file, format, args);
  96
  97   /* Shrink the buffer to the space we really currently need.  */
  98   obstack_blank_fast (obstack, (new_f.ofile.file.file._IO_write_ptr
  99                                 - new_f.ofile.file.file._IO_write_end));
 100
 101   return result;
 102 }
 103 libc_hidden_def (__obstack_vprintf_chk)
 104
 105
 106 int
 107 __obstack_printf_chk (struct obstack *obstack, int flags, const char *format,
 108                       ...)
 109 {
 110   int result;
 111   va_list ap;
 112   va_start (ap, format);
 113   result = __obstack_vprintf_chk (obstack, flags, format, ap);
 114   va_end (ap);
 115   return result;
 116 }