glibc/libio/vsnprintf.c
Zack Weinberg 698fb75b9f Add __v*printf_internal with flags arguments
There are a lot more printf variants than there are scanf variants,
and the code for setting up and tearing down their custom FILE
variants around the call to __vf(w)printf is more complicated and
variable.  Therefore, I have added _internal versions of all the
v*printf variants, rather than introducing helper routines so that
they can all directly call __vf(w)printf_internal, as was done with
scanf.

As with the scanf changes, in this patch the _internal functions still
look at the environmental mode bits and all callers pass 0 for the
flags parameter.

Several of the affected public functions had _IO_ name aliases that
were not exported (but, in one case, appeared in libio.h anyway);
I was originally planning to leave them as aliases to avoid having
to touch internal callers, but it turns out ldbl_*_alias only work
for exported symbols, so they've all been removed instead.  It also
turns out there were hardly any internal callers.  _IO_vsprintf and
_IO_vfprintf *are* exported, so those two stick around.

Summary for the changes to each of the affected symbols:

  _IO_vfprintf, _IO_vsprintf:
    All internal calls removed, thus the internal declarations, as well
    as uses of libc_hidden_proto and libc_hidden_def, were also removed.
    The external symbol is now exposed via uses of ldbl_strong_alias
    to __vfprintf_internal and __vsprintf_internal, respectively.

  _IO_vasprintf, _IO_vdprintf, _IO_vsnprintf,
  _IO_vfwprintf, _IO_vswprintf,
  _IO_obstack_vprintf, _IO_obstack_printf:
    All internal calls removed, thus declaration in internal headers
    were also removed.  They were never exported, so there are no
    aliases tying them to the internal functions.  I.e.: entirely gone.

  __vsnprintf:
    Internal calls were always preceded by macros such as
      #define __vsnprintf _IO_vsnprintf, and
      #define __vsnprintf vsnprintf
    The macros were removed and their uses replaced with calls to the
    new internal function __vsnprintf_internal.  Since there were no
    internal calls, the internal declaration was also removed.  The
    external symbol is preserved with ldbl_weak_alias to ___vsnprintf.

  __vfwprintf:
    All internal calls converted into calls to __vfwprintf_internal,
    thus the internal declaration was removed.  The function is now a
    wrapper that calls __vfwprintf_internal.  The external symbol is
    preserved.

  __vswprintf:
    Similarly, but no external symbol.

  __vasprintf, __vdprintf, __vfprintf, __vsprintf:
    New internal wrappers.  Not exported.

  vasprintf, vdprintf, vfprintf, vsprintf, vsnprintf,
  vfwprintf, vswprintf,
  obstack_vprintf, obstack_printf:
    These functions used to be aliases to the respective _IO_* function,
    they are now aliases to their respective __* functions.

Tested for powerpc and powerpc64le.
2018-12-05 18:15:42 -02:00

128 lines
4.4 KiB
C

/* Copyright (C) 1994-2018 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
<http://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 _IO_strn_overflow (FILE *fp, int c) __THROW;
static int
_IO_strn_overflow (FILE *fp, int c)
{
/* When we come to here this means the user supplied buffer is
filled. But since we must return the number of characters which
would have been written in total we must provide a buffer for
further use. We can do this by writing on and on in the overflow
buffer in the _IO_strnfile structure. */
_IO_strnfile *snf = (_IO_strnfile *) fp;
if (fp->_IO_buf_base != snf->overflow_buf)
{
/* Terminate the string. We know that there is room for at
least one more character since we initialized the stream with
a size to make this possible. */
*fp->_IO_write_ptr = '\0';
_IO_setb (fp, snf->overflow_buf,
snf->overflow_buf + sizeof (snf->overflow_buf), 0);
fp->_IO_write_base = snf->overflow_buf;
fp->_IO_read_base = snf->overflow_buf;
fp->_IO_read_ptr = snf->overflow_buf;
fp->_IO_read_end = snf->overflow_buf + sizeof (snf->overflow_buf);
}
fp->_IO_write_ptr = snf->overflow_buf;
fp->_IO_write_end = snf->overflow_buf;
/* Since we are not really interested in storing the characters
which do not fit in the buffer we simply ignore it. */
return c;
}
const struct _IO_jump_t _IO_strn_jumps libio_vtable attribute_hidden =
{
JUMP_INIT_DUMMY,
JUMP_INIT(finish, _IO_str_finish),
JUMP_INIT(overflow, _IO_strn_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)
};
int
__vsnprintf_internal (char *string, size_t maxlen, const char *format,
va_list args, unsigned int mode_flags)
{
_IO_strnfile sf;
int ret;
#ifdef _IO_MTSAFE_IO
sf.f._sbf._f._lock = NULL;
#endif
/* We need to handle the special case where MAXLEN is 0. Use the
overflow buffer right from the start. */
if (maxlen == 0)
{
string = sf.overflow_buf;
maxlen = sizeof (sf.overflow_buf);
}
_IO_no_init (&sf.f._sbf._f, _IO_USER_LOCK, -1, NULL, NULL);
_IO_JUMPS (&sf.f._sbf) = &_IO_strn_jumps;
string[0] = '\0';
_IO_str_init_static_internal (&sf.f, string, maxlen - 1, string);
ret = __vfprintf_internal (&sf.f._sbf._f, format, args, mode_flags);
if (sf.f._sbf._f._IO_buf_base != sf.overflow_buf)
*sf.f._sbf._f._IO_write_ptr = '\0';
return ret;
}
int
___vsnprintf (char *string, size_t maxlen, const char *format, va_list args)
{
return __vsnprintf_internal (string, maxlen, format, args, 0);
}
ldbl_weak_alias (___vsnprintf, __vsnprintf)
ldbl_weak_alias (___vsnprintf, vsnprintf)