libio/obprintf.c

   1 /* Print output of stream to given obstack.
   2    Copyright (C) 1996-2020 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    <https://www.gnu.org/licenses/>.  */
  19
  20
  21 #include <stdlib.h>
  22 #include "libioP.h"
  23 #include "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
  39 static int
  40 _IO_obstack_overflow (FILE *fp, int c)
  41 {
  42   struct obstack *obstack = ((struct _IO_obstack_file *) fp)->obstack;
  43   int size;
  44
  45   /* Make room for another character.  This might as well allocate a
  46      new chunk a memory and moves the old contents over.  */
  47   assert (c != EOF);
  48   obstack_1grow (obstack, c);
  49
  50   /* Setup the buffer pointers again.  */
  51   fp->_IO_write_base = obstack_base (obstack);
  52   fp->_IO_write_ptr = obstack_next_free (obstack);
  53   size = obstack_room (obstack);
  54   fp->_IO_write_end = fp->_IO_write_ptr + size;
  55   /* Now allocate the rest of the current chunk.  */
  56   obstack_blank_fast (obstack, size);
  57
  58   return c;
  59 }
  60
  61
  62 static size_t
  63 _IO_obstack_xsputn (FILE *fp, const void *data, size_t n)
  64 {
  65   struct obstack *obstack = ((struct _IO_obstack_file *) fp)->obstack;
  66
  67   if (fp->_IO_write_ptr + n > fp->_IO_write_end)
  68     {
  69       int size;
  70
  71       /* We need some more memory.  First shrink the buffer to the
  72          space we really currently need.  */
  73       obstack_blank_fast (obstack, fp->_IO_write_ptr - fp->_IO_write_end);
  74
  75       /* Now grow for N bytes, and put the data there.  */
  76       obstack_grow (obstack, data, n);
  77
  78       /* Setup the buffer pointers again.  */
  79       fp->_IO_write_base = obstack_base (obstack);
  80       fp->_IO_write_ptr = obstack_next_free (obstack);
  81       size = obstack_room (obstack);
  82       fp->_IO_write_end = fp->_IO_write_ptr + size;
  83       /* Now allocate the rest of the current chunk.  */
  84       obstack_blank_fast (obstack, size);
  85     }
  86   else
  87     fp->_IO_write_ptr = __mempcpy (fp->_IO_write_ptr, data, n);
  88
  89   return n;
  90 }
  91
  92
  93 /* the jump table.  */
  94 const struct _IO_jump_t _IO_obstack_jumps libio_vtable attribute_hidden =
  95 {
  96   JUMP_INIT_DUMMY,
  97   JUMP_INIT(finish, NULL),
  98   JUMP_INIT(overflow, _IO_obstack_overflow),
  99   JUMP_INIT(underflow, NULL),
 100   JUMP_INIT(uflow, NULL),
 101   JUMP_INIT(pbackfail, NULL),
 102   JUMP_INIT(xsputn, _IO_obstack_xsputn),
 103   JUMP_INIT(xsgetn, NULL),
 104   JUMP_INIT(seekoff, NULL),
 105   JUMP_INIT(seekpos, NULL),
 106   JUMP_INIT(setbuf, NULL),
 107   JUMP_INIT(sync, NULL),
 108   JUMP_INIT(doallocate, NULL),
 109   JUMP_INIT(read, NULL),
 110   JUMP_INIT(write, NULL),
 111   JUMP_INIT(seek, NULL),
 112   JUMP_INIT(close, NULL),
 113   JUMP_INIT(stat, NULL),
 114   JUMP_INIT(showmanyc, NULL),
 115   JUMP_INIT(imbue, NULL)
 116 };
 117
 118
 119 int
 120 __obstack_vprintf_internal (struct obstack *obstack, const char *format,
 121                             va_list args, unsigned int mode_flags)
 122 {
 123   struct obstack_FILE
 124     {
 125       struct _IO_obstack_file ofile;
 126   } new_f;
 127   int result;
 128   int size;
 129   int room;
 130
 131 #ifdef _IO_MTSAFE_IO
 132   new_f.ofile.file.file._lock = NULL;
 133 #endif
 134
 135   _IO_no_init (&new_f.ofile.file.file, _IO_USER_LOCK, -1, NULL, NULL);
 136   _IO_JUMPS (&new_f.ofile.file) = &_IO_obstack_jumps;
 137   room = obstack_room (obstack);
 138   size = obstack_object_size (obstack) + room;
 139   if (size == 0)
 140     {
 141       /* We have to handle the allocation a bit different since the
 142          `_IO_str_init_static' function would handle a size of zero
 143          different from what we expect.  */
 144
 145       /* Get more memory.  */
 146       obstack_make_room (obstack, 64);
 147
 148       /* Recompute how much room we have.  */
 149       room = obstack_room (obstack);
 150       size = room;
 151
 152       assert (size != 0);
 153     }
 154
 155   _IO_str_init_static_internal ((struct _IO_strfile_ *) &new_f.ofile,
 156                                 obstack_base (obstack),
 157                                 size, obstack_next_free (obstack));
 158   /* Now allocate the rest of the current chunk.  */
 159   assert (size == (new_f.ofile.file.file._IO_write_end
 160                    - new_f.ofile.file.file._IO_write_base));
 161   assert (new_f.ofile.file.file._IO_write_ptr
 162           == (new_f.ofile.file.file._IO_write_base
 163               + obstack_object_size (obstack)));
 164   obstack_blank_fast (obstack, room);
 165
 166   new_f.ofile.obstack = obstack;
 167
 168   result = __vfprintf_internal (&new_f.ofile.file.file, format, args,
 169                                 mode_flags);
 170
 171   /* Shrink the buffer to the space we really currently need.  */
 172   obstack_blank_fast (obstack, (new_f.ofile.file.file._IO_write_ptr
 173                                 - new_f.ofile.file.file._IO_write_end));
 174
 175   return result;
 176 }
 177
 178 int
 179 __obstack_vprintf (struct obstack *obstack, const char *format, va_list ap)
 180 {
 181   return __obstack_vprintf_internal (obstack, format, ap, 0);
 182 }
 183 ldbl_weak_alias (__obstack_vprintf, obstack_vprintf)
 184
 185 int
 186 __obstack_printf (struct obstack *obstack, const char *format, ...)
 187 {
 188   int result;
 189   va_list ap;
 190   va_start (ap, format);
 191   result = __obstack_vprintf_internal (obstack, format, ap, 0);
 192   va_end (ap);
 193   return result;
 194 }
 195 ldbl_weak_alias (__obstack_printf, obstack_printf)