1/* Copyright (C) 1994-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>.
17
18 As a special exception, if you link the code in this file with
19 files compiled with a GNU compiler to produce an executable,
20 that does not cause the resulting executable to be covered by
21 the GNU Lesser General Public License. This exception does not
22 however invalidate any other reasons why the executable file
23 might be covered by the GNU Lesser General Public License.
24 This exception applies to code released by its copyright holders
25 in files containing the exception. */
26
27#include "libioP.h"
28#include "strfile.h"
29
30
31static wint_t _IO_wstrn_overflow (FILE *fp, wint_t c) __THROW;
32
33static wint_t
34_IO_wstrn_overflow (FILE *fp, wint_t c)
35{
36 /* When we come to here this means the user supplied buffer is
37 filled. But since we must return the number of characters which
38 would have been written in total we must provide a buffer for
39 further use. We can do this by writing on and on in the overflow
40 buffer in the _IO_wstrnfile structure. */
41 _IO_wstrnfile *snf = (_IO_wstrnfile *) fp;
42
43 if (fp->_wide_data->_IO_buf_base != snf->overflow_buf)
44 {
45 _IO_wsetb (fp, snf->overflow_buf,
46 snf->overflow_buf + (sizeof (snf->overflow_buf)
47 / sizeof (wchar_t)), 0);
48
49 fp->_wide_data->_IO_write_base = snf->overflow_buf;
50 fp->_wide_data->_IO_read_base = snf->overflow_buf;
51 fp->_wide_data->_IO_read_ptr = snf->overflow_buf;
52 fp->_wide_data->_IO_read_end = (snf->overflow_buf
53 + (sizeof (snf->overflow_buf)
54 / sizeof (wchar_t)));
55 }
56
57 fp->_wide_data->_IO_write_ptr = snf->overflow_buf;
58 fp->_wide_data->_IO_write_end = snf->overflow_buf;
59
60 /* Since we are not really interested in storing the characters
61 which do not fit in the buffer we simply ignore it. */
62 return c;
63}
64
65
66const struct _IO_jump_t _IO_wstrn_jumps libio_vtable attribute_hidden =
67{
68 JUMP_INIT_DUMMY,
69 JUMP_INIT(finish, _IO_wstr_finish),
70 JUMP_INIT(overflow, (_IO_overflow_t) _IO_wstrn_overflow),
71 JUMP_INIT(underflow, (_IO_underflow_t) _IO_wstr_underflow),
72 JUMP_INIT(uflow, (_IO_underflow_t) _IO_wdefault_uflow),
73 JUMP_INIT(pbackfail, (_IO_pbackfail_t) _IO_wstr_pbackfail),
74 JUMP_INIT(xsputn, _IO_wdefault_xsputn),
75 JUMP_INIT(xsgetn, _IO_wdefault_xsgetn),
76 JUMP_INIT(seekoff, _IO_wstr_seekoff),
77 JUMP_INIT(seekpos, _IO_default_seekpos),
78 JUMP_INIT(setbuf, _IO_default_setbuf),
79 JUMP_INIT(sync, _IO_default_sync),
80 JUMP_INIT(doallocate, _IO_wdefault_doallocate),
81 JUMP_INIT(read, _IO_default_read),
82 JUMP_INIT(write, _IO_default_write),
83 JUMP_INIT(seek, _IO_default_seek),
84 JUMP_INIT(close, _IO_default_close),
85 JUMP_INIT(stat, _IO_default_stat),
86 JUMP_INIT(showmanyc, _IO_default_showmanyc),
87 JUMP_INIT(imbue, _IO_default_imbue)
88};
89
90
91int
92__vswprintf_internal (wchar_t *string, size_t maxlen, const wchar_t *format,
93 va_list args, unsigned int mode_flags)
94{
95 _IO_wstrnfile sf;
96 int ret;
97 struct _IO_wide_data wd;
98#ifdef _IO_MTSAFE_IO
99 sf.f._sbf._f._lock = NULL;
100#endif
101
102 if (maxlen == 0)
103 /* Since we have to write at least the terminating L'\0' a buffer
104 length of zero always makes the function fail. */
105 return -1;
106
107 _IO_no_init (&sf.f._sbf._f, _IO_USER_LOCK, 0, &wd, &_IO_wstrn_jumps);
108 _IO_fwide (&sf.f._sbf._f, 1);
109 string[0] = L'\0';
110 _IO_wstr_init_static (&sf.f._sbf._f, string, maxlen - 1, string);
111 ret = __vfwprintf_internal ((FILE *) &sf.f._sbf, format, args, mode_flags);
112
113 if (sf.f._sbf._f._wide_data->_IO_buf_base == sf.overflow_buf)
114 /* ISO C99 requires swprintf/vswprintf to return an error if the
115 output does not fit in the provided buffer. */
116 return -1;
117
118 /* Terminate the string. */
119 *sf.f._sbf._f._wide_data->_IO_write_ptr = '\0';
120
121 return ret;
122}
123
124int
125__vswprintf (wchar_t *string, size_t maxlen, const wchar_t *format,
126 va_list args)
127{
128 return __vswprintf_internal (string, maxlen, format, args, 0);
129}
130ldbl_weak_alias (__vswprintf, vswprintf)
131