glibc/wcsmbs/wcrtomb.c
Joseph Myers be8ff03f92 Stop c32rtomb and mbrtoc32 aliasing wcrtomb and mbrtowc (bug 23793).
glibc does:

/* There should be no difference between the UTF-32 handling required
   by c32rtomb and the wchar_t handling which has long since been
   implemented in wcrtomb.  */
weak_alias (__wcrtomb, c32rtomb)

/* There should be no difference between the UTF-32 handling required
   by mbrtoc32 and the wchar_t handling which has long since been
   implemented in mbrtowc.  */
weak_alias (__mbrtowc, mbrtoc32)

The reasoning in those comments to justify those aliases is incorrect:
ISO C requires that, for the case of a NULL mbstate_t* being passed,
each function has its *own* internal static mbstate_t.  Thus a program
must be able to use both wcrtomb and c32rtomb at the same time with
each keeping its own separate state, and likewise for mbrtowc and
mbrtoc32.

This patch duly sets up separarate char32_t function that wrap the
wchar_t ones.  Note that the included test only covers the mbrtoc32 /
mbrtowc pair.  While I think the change made is logically correct for
c32rtomb / wcrtomb as well, I'm not sure we have a locale with a
suitable state-dependent multibyte encoding for testing that part of
the change.

Tested for x86_64.

	[BZ #23793]
	* wcsmbs/c32rtomb.c: New file.
	* wcsmbs/mbrtoc32.c: Likewise.
	* wcsmbs/tst-c32-state.c: Likewise.
	* wcsmbs/mbrtowc.c (mbrtoc32): Do not define as alias.
	* wcsmbs/wcrtomb.c (c32rtomb): Likewise.
	* wcsmbs/Makefile (routines): Add mbrtoc32 and c32rtomb.
	(tests): Add tst-c32-state.
	[$(run-built-tests) = yes] ($(objpfx)tst-c32-state.out): Depend on
	$(gen-locales).
2018-10-22 14:52:14 +00:00

116 lines
3.3 KiB
C

/* Copyright (C) 1996-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
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/>. */
#include <assert.h>
#include <dlfcn.h>
#include <errno.h>
#include <gconv.h>
#include <stdlib.h>
#include <wchar.h>
#include <wcsmbsload.h>
#include <sysdep.h>
#ifndef EILSEQ
# define EILSEQ EINVAL
#endif
/* This is the private state used if PS is NULL. */
static mbstate_t state;
size_t
__wcrtomb (char *s, wchar_t wc, mbstate_t *ps)
{
char buf[MB_LEN_MAX];
struct __gconv_step_data data;
int status;
size_t result;
size_t dummy;
const struct gconv_fcts *fcts;
/* Set information for this step. */
data.__invocation_counter = 0;
data.__internal_use = 1;
data.__flags = __GCONV_IS_LAST;
data.__statep = ps ?: &state;
/* A first special case is if S is NULL. This means put PS in the
initial state. */
if (s == NULL)
{
s = buf;
wc = L'\0';
}
/* Tell where we want to have the result. */
data.__outbuf = (unsigned char *) s;
data.__outbufend = (unsigned char *) s + MB_CUR_MAX;
/* Get the conversion functions. */
fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
__gconv_fct fct = fcts->tomb->__fct;
#ifdef PTR_DEMANGLE
if (fcts->tomb->__shlib_handle != NULL)
PTR_DEMANGLE (fct);
#endif
/* If WC is the NUL character we write into the output buffer the byte
sequence necessary for PS to get into the initial state, followed
by a NUL byte. */
if (wc == L'\0')
{
status = DL_CALL_FCT (fct, (fcts->tomb, &data, NULL, NULL,
NULL, &dummy, 1, 1));
if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
*data.__outbuf++ = '\0';
}
else
{
/* Do a normal conversion. */
const unsigned char *inbuf = (const unsigned char *) &wc;
status = DL_CALL_FCT (fct,
(fcts->tomb, &data, &inbuf,
inbuf + sizeof (wchar_t), NULL, &dummy, 0, 1));
}
/* There must not be any problems with the conversion but illegal input
characters. The output buffer must be large enough, otherwise the
definition of MB_CUR_MAX is not correct. All the other possible
errors also must not happen. */
assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
|| status == __GCONV_ILLEGAL_INPUT
|| status == __GCONV_INCOMPLETE_INPUT
|| status == __GCONV_FULL_OUTPUT);
if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
|| status == __GCONV_FULL_OUTPUT)
result = data.__outbuf - (unsigned char *) s;
else
{
result = (size_t) -1;
__set_errno (EILSEQ);
}
return result;
}
weak_alias (__wcrtomb, wcrtomb)
libc_hidden_weak (wcrtomb)