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
_IO_obstack_overflow(FILE * fp,int c)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
_IO_obstack_xsputn(FILE * fp,const void * data,size_t n)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
__obstack_vprintf_internal(struct obstack * obstack,const char * format,va_list args,unsigned int mode_flags)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
__obstack_vprintf(struct obstack * obstack,const char * format,va_list ap)178 __obstack_vprintf (struct obstack *obstack, const char *format, va_list ap)
179 {
180   return __obstack_vprintf_internal (obstack, format, ap, 0);
181 }
ldbl_weak_alias(__obstack_vprintf,obstack_vprintf)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)
195