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

152 lines
4 KiB
C

/***
*towlower.c - convert wide character to lower case
*
* Copyright (c) 1991-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Defines towlower().
*
*Revision History:
* 10-11-91 ETC Created.
* 12-10-91 ETC Updated nlsapi; added multithread.
* 04-06-92 KRS Make work without _INTL also.
* 01-19-93 CFW Changed LCMapString to LCMapStringW.
* 04-06-93 SKS Replace _CRTAPI* with _cdecl
* 06-02-93 SRW ignore _INTL if _NTSUBSET_ defined.
* 06-11-93 CFW Fix error handling bug.
* 09-15-93 CFW Use ANSI conformant "__" names.
* 09-22-93 CFW Use __crtxxx internal NLS API wrapper.
* 09-29-93 GJF Merged NT SDK and Cuda versions.
* 11-09-93 CFW Add code page for __crtxxx().
* 02-07-94 CFW POSIXify.
* 09-06-94 CFW Remove _INTL switch.
* 10-25-94 GJF Sped up for C locale. Also, added _towlower_lk.
* 09-26-95 GJF New locking macro, and scheme, for functions which
* reference the locale.
* 04-01-96 BWT POSIX work.
* 06-25-96 GJF Removed DLL_FOR_WIN32S and cleaned up the format a
* wee bit.
* 08-27-98 GJF Revised multithread support based on threadlocinfo
* struct.
*
*******************************************************************************/
#include <cruntime.h>
#include <ctype.h>
#include <stdio.h>
#include <locale.h>
#include <setlocal.h>
#include <mtdll.h>
#include <awint.h>
/***
*wchar_t towlower(c) - convert wide character to lower case
*
*Purpose:
* towlower() returns the lowercase equivalent of its argument
*
*Entry:
* c - wchar_t value of character to be converted
*
*Exit:
* if c is an upper case letter, returns wchar_t value of lower case
* representation of c. otherwise, it returns c.
*
*Exceptions:
*
*******************************************************************************/
wchar_t __cdecl towlower (
wchar_t c
)
{
#if !defined(_NTSUBSET_) && !defined(_POSIX_)
#ifdef _MT
pthreadlocinfo ptloci = _getptd()->ptlocinfo;
if ( ptloci != __ptlocinfo )
ptloci = __updatetlocinfo();
if ( c == WEOF )
return c;
if ( ptloci->lc_handle[LC_CTYPE] == _CLOCALEHANDLE )
return __ascii_towlower(c);
return __towlower_mt(ptloci, c);
}
/***
*wchar_t __towlower_mt(ptloci, c) - convert wide character to lower case
*
*Purpose:
* Multi-thread function only! Non-locking version of towlower.
*
*Entry:
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/
wchar_t __cdecl __towlower_mt (
pthreadlocinfo ptloci,
wchar_t c
)
{
#endif /* _MT */
wchar_t widechar;
if (c == WEOF)
return c;
#ifndef _MT
if ( __lc_handle[LC_CTYPE] == _CLOCALEHANDLE )
return __ascii_towlower(c);
#endif
/* if checking case of c does not require API call, do it */
if ( c < 256 ) {
#ifdef _MT
if ( !__iswupper_mt(ptloci, c) ) {
#else
if ( !iswupper(c) ) {
#endif
return c;
}
}
/* convert wide char to lowercase */
#ifdef _MT
if ( 0 == __crtLCMapStringW( ptloci->lc_handle[LC_CTYPE],
#else
if ( 0 == __crtLCMapStringW( __lc_handle[LC_CTYPE],
#endif
LCMAP_LOWERCASE,
(LPCWSTR)&c,
1,
(LPWSTR)&widechar,
1,
#ifdef _MT
ptloci->lc_codepage ) )
#else
__lc_codepage ) )
#endif
{
return c;
}
return widechar;
#else /* _NTSUBSET_/_POSIX_ */
return (iswupper(c) ? (c + (wchar_t)(L'a' - L'A')) : c);
#endif /* _NTSUBSET_/_POSIX_ */
}