[thirdparty/glibc.git] / wcsmbs / btowc.c

/* Copyright (C) 1996-2025 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/>.  */

#include <ctype.h>
#include <dlfcn.h>
#include <gconv.h>
#include <stdio.h>
#include <string.h>
#include <wchar.h>
#include <wcsmbsload.h>
#include <limits.h>

#include <pointer_guard.h>


wint_t
__btowc (int c)
{
  const struct gconv_fcts *fcts;

  /* If the parameter does not fit into one byte or it is the EOF value
     we can give the answer now.  */
  if (c < SCHAR_MIN || c > UCHAR_MAX || c == EOF)
    return WEOF;

  /* We know that only ASCII compatible encodings are used for the
     locale and that the wide character encoding is ISO 10646.  */
  if (isascii (c))
    return (wint_t) c;

  /* Get the conversion functions.  */
  fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  __gconv_btowc_fct btowc_fct = fcts->towc->__btowc_fct;
  if (fcts->towc->__shlib_handle != NULL)
    PTR_DEMANGLE (btowc_fct);

  if (__builtin_expect (fcts->towc_nsteps == 1, 1)
      && __builtin_expect (btowc_fct != NULL, 1))
    {
      /* Use the shortcut function.  */
      return DL_CALL_FCT (btowc_fct, (fcts->towc, (unsigned char) c));
    }
  else
    {
      /* Fall back to the slow but generic method.  */
      wchar_t result;
      struct __gconv_step_data data;
      unsigned char inbuf[1];
      const unsigned char *inptr = inbuf;
      size_t dummy;
      int status;

      /* Tell where we want the result.  */
      data.__outbuf = (unsigned char *) &result;
      data.__outbufend = data.__outbuf + sizeof (wchar_t);
      data.__invocation_counter = 0;
      data.__internal_use = 1;
      data.__flags = __GCONV_IS_LAST;
      data.__statep = &data.__state;

      /* Make sure we start in the initial state.  */
      memset (&data.__state, '\0', sizeof (mbstate_t));

      /* Create the input string.  */
      inbuf[0] = c;

      __gconv_fct fct = fcts->towc->__fct;
      if (fcts->towc->__shlib_handle != NULL)
	PTR_DEMANGLE (fct);
      status = DL_CALL_FCT (fct, (fcts->towc, &data, &inptr, inptr + 1,
				  NULL, &dummy, 0, 1));

      if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
	  && status != __GCONV_EMPTY_INPUT)
	/* The conversion failed.  */
	result = WEOF;

      return result;
    }
}
weak_alias (__btowc, btowc)
Commit	Line	Data
	1	/* Copyright (C) 1996-2025 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	#include <ctype.h>
	19	#include <dlfcn.h>
	20	#include <gconv.h>
	21	#include <stdio.h>
	22	#include <string.h>
	23	#include <wchar.h>
	24	#include <wcsmbsload.h>
	25	#include <limits.h>
	26
	27	#include <pointer_guard.h>
	28
	29
	30	wint_t
	31	__btowc (int c)
	32	{
	33	const struct gconv_fcts *fcts;
	34
	35	/* If the parameter does not fit into one byte or it is the EOF value
	36	we can give the answer now. */
	37	if (c < SCHAR_MIN \|\| c > UCHAR_MAX \|\| c == EOF)
	38	return WEOF;
	39
	40	/* We know that only ASCII compatible encodings are used for the
	41	locale and that the wide character encoding is ISO 10646. */
	42	if (isascii (c))
	43	return (wint_t) c;
	44
	45	/* Get the conversion functions. */
	46	fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
	47	__gconv_btowc_fct btowc_fct = fcts->towc->__btowc_fct;
	48	if (fcts->towc->__shlib_handle != NULL)
	49	PTR_DEMANGLE (btowc_fct);
	50
	51	if (__builtin_expect (fcts->towc_nsteps == 1, 1)
	52	&& __builtin_expect (btowc_fct != NULL, 1))
	53	{
	54	/* Use the shortcut function. */
	55	return DL_CALL_FCT (btowc_fct, (fcts->towc, (unsigned char) c));
	56	}
	57	else
	58	{
	59	/* Fall back to the slow but generic method. */
	60	wchar_t result;
	61	struct __gconv_step_data data;
	62	unsigned char inbuf[1];
	63	const unsigned char *inptr = inbuf;
	64	size_t dummy;
	65	int status;
	66
	67	/* Tell where we want the result. */
	68	data.__outbuf = (unsigned char *) &result;
	69	data.__outbufend = data.__outbuf + sizeof (wchar_t);
	70	data.__invocation_counter = 0;
	71	data.__internal_use = 1;
	72	data.__flags = __GCONV_IS_LAST;
	73	data.__statep = &data.__state;
	74
	75	/* Make sure we start in the initial state. */
	76	memset (&data.__state, '\0', sizeof (mbstate_t));
	77
	78	/* Create the input string. */
	79	inbuf[0] = c;
	80
	81	__gconv_fct fct = fcts->towc->__fct;
	82	if (fcts->towc->__shlib_handle != NULL)
	83	PTR_DEMANGLE (fct);
	84	status = DL_CALL_FCT (fct, (fcts->towc, &data, &inptr, inptr + 1,
	85	NULL, &dummy, 0, 1));
	86
	87	if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
	88	&& status != __GCONV_EMPTY_INPUT)
	89	/* The conversion failed. */
	90	result = WEOF;
	91
	92	return result;
	93	}
	94	}
	95	weak_alias (__btowc, btowc)