libio/obprintf.c

   1 /* Print output of stream to given obstack.
   2    Copyright (C) 1996-2022 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19
  20 #include <stdlib.h>
  21 #include "libioP.h"
  22 #include "strfile.h"
  23 #include <assert.h>
  24 #include <string.h>
  25 #include <errno.h>
  26 #include <obstack.h>
  27 #include <stdarg.h>
  28 #include <stdio_ext.h>
  29
  30
  31 struct _IO_obstack_file
  32 {
  33   struct _IO_FILE_plus file;
  34   struct obstack *obstack;
  35 };
  36
  37
  38 static int
  39 _IO_obstack_overflow (FILE *fp, int c)
  40 {
  41   struct obstack *obstack = ((struct _IO_obstack_file *) fp)->obstack;
  42   int size;
  43
  44   /* Make room for another character.  This might as well allocate a
  45      new chunk a memory and moves the old contents over.  */
  46   assert (c != EOF);
  47   obstack_1grow (obstack, c);
  48
  49   /* Setup the buffer pointers again.  */
  50   fp->_IO_write_base = obstack_base (obstack);
  51   fp->_IO_write_ptr = obstack_next_free (obstack);
  52   size = obstack_room (obstack);
  53   fp->_IO_write_end = fp->_IO_write_ptr + size;
  54   /* Now allocate the rest of the current chunk.  */
  55   obstack_blank_fast (obstack, size);
  56
  57   return c;
  58 }
  59
  60
  61 static size_t
  62 _IO_obstack_xsputn (FILE *fp, const void *data, size_t n)
  63 {
  64   struct obstack *obstack = ((struct _IO_obstack_file *) fp)->obstack;
  65
  66   if (fp->_IO_write_ptr + n > fp->_IO_write_end)
  67     {
  68       int size;
  69
  70       /* We need some more memory.  First shrink the buffer to the
  71          space we really currently need.  */
  72       obstack_blank_fast (obstack, fp->_IO_write_ptr - fp->_IO_write_end);
  73
  74       /* Now grow for N bytes, and put the data there.  */
  75       obstack_grow (obstack, data, n);
  76
  77       /* Setup the buffer pointers again.  */
  78       fp->_IO_write_base = obstack_base (obstack);
  79       fp->_IO_write_ptr = obstack_next_free (obstack);
  80       size = obstack_room (obstack);
  81       fp->_IO_write_end = fp->_IO_write_ptr + size;
  82       /* Now allocate the rest of the current chunk.  */
  83       obstack_blank_fast (obstack, size);
  84     }
  85   else
  86     fp->_IO_write_ptr = __mempcpy (fp->_IO_write_ptr, data, n);
  87
  88   return n;
  89 }
  90
  91
  92 /* the jump table.  */
  93 const struct _IO_jump_t _IO_obstack_jumps libio_vtable attribute_hidden =
  94 {
  95   JUMP_INIT_DUMMY,
  96   JUMP_INIT(finish, NULL),
  97   JUMP_INIT(overflow, _IO_obstack_overflow),
  98   JUMP_INIT(underflow, NULL),
  99   JUMP_INIT(uflow, NULL),
 100   JUMP_INIT(pbackfail, NULL),
 101   JUMP_INIT(xsputn, _IO_obstack_xsputn),
 102   JUMP_INIT(xsgetn, NULL),
 103   JUMP_INIT(seekoff, NULL),
 104   JUMP_INIT(seekpos, NULL),
 105   JUMP_INIT(setbuf, NULL),
 106   JUMP_INIT(sync, NULL),
 107   JUMP_INIT(doallocate, NULL),
 108   JUMP_INIT(read, NULL),
 109   JUMP_INIT(write, NULL),
 110   JUMP_INIT(seek, NULL),
 111   JUMP_INIT(close, NULL),
 112   JUMP_INIT(stat, NULL),
 113   JUMP_INIT(showmanyc, NULL),
 114   JUMP_INIT(imbue, NULL)
 115 };
 116
 117
 118 int
 119 __obstack_vprintf_internal (struct obstack *obstack, const char *format,
 120                             va_list args, unsigned int mode_flags)
 121 {
 122   struct obstack_FILE
 123     {
 124       struct _IO_obstack_file ofile;
 125   } new_f;
 126   int result;
 127   int size;
 128   int room;
 129
 130 #ifdef _IO_MTSAFE_IO
 131   new_f.ofile.file.file._lock = NULL;
 132 #endif
 133
 134   _IO_no_init (&new_f.ofile.file.file, _IO_USER_LOCK, -1, NULL, NULL);
 135   _IO_JUMPS (&new_f.ofile.file) = &_IO_obstack_jumps;
 136   room = obstack_room (obstack);
 137   size = obstack_object_size (obstack) + room;
 138   if (size == 0)
 139     {
 140       /* We have to handle the allocation a bit different since the
 141          `_IO_str_init_static' function would handle a size of zero
 142          different from what we expect.  */
 143
 144       /* Get more memory.  */
 145       obstack_make_room (obstack, 64);
 146
 147       /* Recompute how much room we have.  */
 148       room = obstack_room (obstack);
 149       size = room;
 150
 151       assert (size != 0);
 152     }
 153
 154   _IO_str_init_static_internal ((struct _IO_strfile_ *) &new_f.ofile,
 155                                 obstack_base (obstack),
 156                                 size, obstack_next_free (obstack));
 157   /* Now allocate the rest of the current chunk.  */
 158   assert (size == (new_f.ofile.file.file._IO_write_end
 159                    - new_f.ofile.file.file._IO_write_base));
 160   assert (new_f.ofile.file.file._IO_write_ptr
 161           == (new_f.ofile.file.file._IO_write_base
 162               + obstack_object_size (obstack)));
 163   obstack_blank_fast (obstack, room);
 164
 165   new_f.ofile.obstack = obstack;
 166
 167   result = __vfprintf_internal (&new_f.ofile.file.file, format, args,
 168                                 mode_flags);
 169
 170   /* Shrink the buffer to the space we really currently need.  */
 171   obstack_blank_fast (obstack, (new_f.ofile.file.file._IO_write_ptr
 172                                 - new_f.ofile.file.file._IO_write_end));
 173
 174   return result;
 175 }
 176
 177 int
 178 __obstack_vprintf (struct obstack *obstack, const char *format, va_list ap)
 179 {
 180   return __obstack_vprintf_internal (obstack, format, ap, 0);
 181 }
 182 ldbl_weak_alias (__obstack_vprintf, obstack_vprintf)
 183
 184 int
 185 __obstack_printf (struct obstack *obstack, const char *format, ...)
 186 {
 187   int result;
 188   va_list ap;
 189   va_start (ap, format);
 190   result = __obstack_vprintf_internal (obstack, format, ap, 0);
 191   va_end (ap);
 192   return result;
 193 }
 194 ldbl_weak_alias (__obstack_printf, obstack_printf)