windows-nt/Source/XPSP1/NT/base/crts/crtw32/convert/mblen.c
2020-09-26 16:20:57 +08:00

166 lines
5.1 KiB
C

/***
*mblen.c - length of multibyte character
*
* Copyright (c) 1990-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Return the number of bytes contained in a multibyte character.
*
*Revision History:
* 03-19-90 KRS Module created.
* 12-20-90 KRS Include ctype.h.
* 03-20-91 KRS Ported from 16-bit tree.
* 12-09-91 ETC Updated comments; move __mb_cur_max to nlsdata1.c;
* add multithread.
* 04-06-93 SKS Replace _CRTAPI* with _cdecl
* 06-01-93 CFW Re-write; verify valid MB char, proper error return,
* optimize, correct conversion bug.
* 06-02-93 SRW ignore _INTL if _NTSUBSET_ defined.
* 09-15-93 CFW Use ANSI conformant "__" names.
* 09-27-93 GJF Merged NT SDK and Cuda versions.
* 10-22-93 CFW Test for invalid MB chars using global preset flag.
* 01-14-94 SRW if _NTSUBSET_ defined call Rtl functions
* 09-06-94 CFW Remove _INTL switch.
* 12-21-94 CFW Remove invalid MB chars NT 3.1 hack.
* 01-07-95 CFW Mac merge cleanup.
* 02-06-95 CFW assert -> _ASSERTE.
* 04-01-96 BWT POSIX work.
* 06-25-96 GJF Replaced defined(_WIN32) with !defined(_MAC). Also,
* polished format a bit.
* 02-27-98 RKP Added 64 bit support.
* 07-27-98 GJF Revised multithread support based on threadlocinfo
* struct.
* 05-17-99 PML Remove all Macintosh support.
*
*******************************************************************************/
#if defined(_NTSUBSET_) || defined(_POSIX_)
#include <nt.h>
#include <ntrtl.h>
#include <nturtl.h>
#endif
#include <internal.h>
#include <locale.h>
#include <setlocal.h>
#include <cruntime.h>
#include <stdlib.h>
#include <ctype.h>
#include <mtdll.h>
#include <dbgint.h>
/***
*int mblen() - length of multibyte character
*
*Purpose:
* Return the number of bytes contained in a multibyte character.
* [ANSI].
*
*Entry:
* const char *s = pointer to multibyte character
* size_t n = maximum length of multibyte character to consider
*
*Exit:
* If s = NULL, returns 0, indicating we use (only) state-independent
* character encodings.
*
* If s != NULL, returns: 0 (if *s = null char),
* -1 (if the next n or fewer bytes not valid
* mbc),
* number of bytes contained in multibyte char
*
*Exceptions:
*
*******************************************************************************/
int __cdecl mblen
(
const char * s,
size_t n
)
{
#ifdef _MT
pthreadlocinfo ptloci = _getptd()->ptlocinfo;
if ( ptloci != __ptlocinfo )
ptloci = __updatetlocinfo();
_ASSERTE (ptloci->mb_cur_max == 1 || ptloci->mb_cur_max == 2);
#else
_ASSERTE (MB_CUR_MAX == 1 || MB_CUR_MAX == 2);
#endif
if ( !s || !(*s) || (n == 0) )
/* indicate do not have state-dependent encodings,
empty string length is 0 */
return 0;
#if !defined(_NTSUBSET_) && !defined(_POSIX_)
#ifdef _MT
if ( __isleadbyte_mt(ptloci, (unsigned char)*s) )
#else
if ( isleadbyte((unsigned char)*s) )
#endif
{
/* multi-byte char */
/* verify valid MB char */
#ifdef _MT
if ( ptloci->mb_cur_max <= 1 ||
(int)n < ptloci->mb_cur_max ||
MultiByteToWideChar( ptloci->lc_codepage,
MB_PRECOMPOSED | MB_ERR_INVALID_CHARS,
s,
ptloci->mb_cur_max,
NULL,
0 ) == 0 )
#else
if ( MB_CUR_MAX <= 1 ||
(int)n < MB_CUR_MAX ||
MultiByteToWideChar( __lc_codepage,
MB_PRECOMPOSED | MB_ERR_INVALID_CHARS,
s,
MB_CUR_MAX,
NULL,
0 ) == 0 )
#endif
/* bad MB char */
return -1;
else
#ifdef _MT
return ptloci->mb_cur_max;
#else
return MB_CUR_MAX;
#endif
}
else {
/* single byte char */
/* verify valid SB char */
#ifdef _MT
if ( MultiByteToWideChar( __lc_codepage,
#else
if ( MultiByteToWideChar( __lc_codepage,
#endif
MB_PRECOMPOSED | MB_ERR_INVALID_CHARS,
s,
1,
NULL,
0 ) == 0 )
return -1;
return sizeof(char);
}
#else /* _NTSUBSET_ */
{
char *s1 = (char *)s;
RtlAnsiCharToUnicodeChar( &s1 );
return (int)(s1 - s);
}
#endif /* _NTSUBSET_ */
}