mcst-linux-kernel/glibc-2.35/libio/iovsprintf.c

110 lines
3.8 KiB
C

/* Copyright (C) 1993-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>.
As a special exception, if you link the code in this file with
files compiled with a GNU compiler to produce an executable,
that does not cause the resulting executable to be covered by
the GNU Lesser General Public License. This exception does not
however invalidate any other reasons why the executable file
might be covered by the GNU Lesser General Public License.
This exception applies to code released by its copyright holders
in files containing the exception. */
#include "libioP.h"
#include "strfile.h"
static int __THROW
_IO_str_chk_overflow (FILE *fp, int c)
{
/* If we get here, the user-supplied buffer would be overrun by
further output. */
__chk_fail ();
}
static const struct _IO_jump_t _IO_str_chk_jumps libio_vtable =
{
JUMP_INIT_DUMMY,
JUMP_INIT(finish, _IO_str_finish),
JUMP_INIT(overflow, _IO_str_chk_overflow),
JUMP_INIT(underflow, _IO_str_underflow),
JUMP_INIT(uflow, _IO_default_uflow),
JUMP_INIT(pbackfail, _IO_str_pbackfail),
JUMP_INIT(xsputn, _IO_default_xsputn),
JUMP_INIT(xsgetn, _IO_default_xsgetn),
JUMP_INIT(seekoff, _IO_str_seekoff),
JUMP_INIT(seekpos, _IO_default_seekpos),
JUMP_INIT(setbuf, _IO_default_setbuf),
JUMP_INIT(sync, _IO_default_sync),
JUMP_INIT(doallocate, _IO_default_doallocate),
JUMP_INIT(read, _IO_default_read),
JUMP_INIT(write, _IO_default_write),
JUMP_INIT(seek, _IO_default_seek),
JUMP_INIT(close, _IO_default_close),
JUMP_INIT(stat, _IO_default_stat),
JUMP_INIT(showmanyc, _IO_default_showmanyc),
JUMP_INIT(imbue, _IO_default_imbue)
};
/* This function is called by regular vsprintf with maxlen set to -1,
and by vsprintf_chk with maxlen set to the size of the output
string. In the former case, _IO_str_chk_overflow will never be
called; in the latter case it will crash the program if the buffer
overflows. */
int
__vsprintf_internal (char *string, size_t maxlen,
const char *format, va_list args,
unsigned int mode_flags)
{
_IO_strfile sf;
int ret;
#ifdef _IO_MTSAFE_IO
sf._sbf._f._lock = NULL;
#endif
_IO_no_init (&sf._sbf._f, _IO_USER_LOCK, -1, NULL, NULL);
/* When called from fortified sprintf/vsprintf, erase the destination
buffer and try to detect overflows. When called from regular
sprintf/vsprintf, do not erase the destination buffer, because
known user code relies on this behavior (even though its undefined
by ISO C), nor try to detect overflows. */
if ((mode_flags & PRINTF_CHK) != 0)
{
_IO_JUMPS (&sf._sbf) = &_IO_str_chk_jumps;
string[0] = '\0';
}
else
_IO_JUMPS (&sf._sbf) = &_IO_str_jumps;
_IO_str_init_static_internal (&sf, string,
(maxlen == -1) ? -1 : maxlen - 1,
string);
ret = __vfprintf_internal (&sf._sbf._f, format, args, mode_flags);
*sf._sbf._f._IO_write_ptr = '\0';
return ret;
}
int
__vsprintf (char *string, const char *format, va_list args)
{
return __vsprintf_internal (string, -1, format, args, 0);
}
ldbl_strong_alias (__vsprintf, _IO_vsprintf)
ldbl_weak_alias (__vsprintf, vsprintf)