debug/obprintf_chk.c

   1 /* Print output of stream to given obstack.
   2    Copyright (C) 1996-2016 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20
  21 #include <stdlib.h>
  22 #include <libioP.h>
  23 #include "../libio/strfile.h"
  24 #include <assert.h>
  25 #include <string.h>
  26 #include <errno.h>
  27 #include <obstack.h>
  28 #include <stdarg.h>
  29 #include <stdio_ext.h>
  30
  31
  32 struct _IO_obstack_file
  33 {
  34   struct _IO_FILE_plus file;
  35   struct obstack *obstack;
  36 };
  37
  38 extern const struct _IO_jump_t _IO_obstack_jumps libio_vtable attribute_hidden;
  39
  40 int
  41 __obstack_vprintf_chk (struct obstack *obstack, int flags, const char *format,
  42                        va_list args)
  43 {
  44   struct obstack_FILE
  45     {
  46       struct _IO_obstack_file ofile;
  47     } new_f;
  48   int result;
  49   int size;
  50   int room;
  51
  52 #ifdef _IO_MTSAFE_IO
  53   new_f.ofile.file.file._lock = NULL;
  54 #endif
  55
  56   _IO_no_init (&new_f.ofile.file.file, _IO_USER_LOCK, -1, NULL, NULL);
  57   _IO_JUMPS (&new_f.ofile.file) = &_IO_obstack_jumps;
  58   room = obstack_room (obstack);
  59   size = obstack_object_size (obstack) + room;
  60   if (size == 0)
  61     {
  62       /* We have to handle the allocation a bit different since the
  63          `_IO_str_init_static' function would handle a size of zero
  64          different from what we expect.  */
  65
  66       /* Get more memory.  */
  67       obstack_make_room (obstack, 64);
  68
  69       /* Recompute how much room we have.  */
  70       room = obstack_room (obstack);
  71       size = room;
  72
  73       assert (size != 0);
  74     }
  75
  76   _IO_str_init_static_internal ((struct _IO_strfile_ *) &new_f.ofile,
  77                                 obstack_base (obstack),
  78                                 size, obstack_next_free (obstack));
  79   /* Now allocate the rest of the current chunk.  */
  80   assert (size == (new_f.ofile.file.file._IO_write_end
  81                    - new_f.ofile.file.file._IO_write_base));
  82   assert (new_f.ofile.file.file._IO_write_ptr
  83           == (new_f.ofile.file.file._IO_write_base
  84               + obstack_object_size (obstack)));
  85   obstack_blank_fast (obstack, room);
  86
  87   new_f.ofile.obstack = obstack;
  88
  89   /* For flags > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
  90      can only come from read-only format strings.  */
  91   if (flags > 0)
  92     new_f.ofile.file.file._flags2 |= _IO_FLAGS2_FORTIFY;
  93
  94   result = _IO_vfprintf (&new_f.ofile.file.file, format, args);
  95
  96   /* Shrink the buffer to the space we really currently need.  */
  97   obstack_blank_fast (obstack, (new_f.ofile.file.file._IO_write_ptr
  98                                 - new_f.ofile.file.file._IO_write_end));
  99
 100   return result;
 101 }
 102 libc_hidden_def (__obstack_vprintf_chk)
 103
 104
 105 int
 106 __obstack_printf_chk (struct obstack *obstack, int flags, const char *format,
 107                       ...)
 108 {
 109   int result;
 110   va_list ap;
 111   va_start (ap, format);
 112   result = __obstack_vprintf_chk (obstack, flags, format, ap);
 113   va_end (ap);
 114   return result;
 115 }