windows-nt/Source/XPSP1/NT/base/crts/crtw32/convert/tolower.c

/***
*tolower.c - convert character to lower case
*
*       Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
*       Defines function versions of _tolower() and tolower().
*
*Revision History:
*       11-09-84  DFW   created
*       12-11-87  JCR   Added "_LOAD_DS" to declaration
*       02-23-89  GJF   Added function version of _tolower and cleaned up.
*       03-26-89  GJF   Migrated to 386 tree
*       03-06-90  GJF   Fixed calling type, added #include <cruntime.h> and
*                       fixed copyright.
*       09-27-90  GJF   New-style function declarators.
*       10-11-91  ETC   Locale support for tolower under _INTL switch.
*       12-10-91  ETC   Updated nlsapi; added multithread.
*       12-17-92  KRS   Updated and optimized for latest NLSAPI.  Bug-fixes.
*       01-19-93  CFW   Fixed typo.
*       03-25-93  CFW   _tolower now defined when _INTL.
*       04-06-93  SKS   Replace _CRTAPI* with _cdecl
*       06-01-93  CFW   Simplify "C" locale test.
*       06-02-93  SRW   ignore _INTL if _NTSUBSET_ defined.
*       09-15-93  CFW   Change buffer to unsigned char to fix nasty cast bug.
*       09-15-93  CFW   Use ANSI conformant "__" names.
*       09-22-93  CFW   Use __crtxxx internal NLS API wrapper.
*       09-28-93  GJF   Merged NT SDK and Cuda versions.
*       11-09-93  CFW   Add code page for __crtxxx().
*       09-06-94  CFW   Remove _INTL switch.
*       10-17-94  GJF   Sped up for C locale. Also, added _tolower_lk.
*       01-07-95  CFW   Mac merge cleanup.
*       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. Replaced defined(_WIN32) with
*                       !defined(_MAC). Polished the format a bit.
*       03-17-97  RDK   Added error flag to __crtLCMapStringA.
*       08-27-98  GJF   Revised multithread support based on threadlocinfo
*                       struct.
*       05-17-99  PML   Remove all Macintosh support.
*       09-03-00  GB    Modified for increased performance.
*       04-03-01  PML   Reverse lead/trail bytes in composed char (vs7#232853)
*
*******************************************************************************/

#include <cruntime.h>
#include <ctype.h>
#include <stddef.h>
#include <locale.h>
#include <setlocal.h>
#include <mtdll.h>
#include <awint.h>

/* remove macro defintions of _tolower() and tolower()
 */
#undef  _tolower
#undef  tolower

/* define function-like macro equivalent to _tolower()
 */
#define mklower(c)  ( (c)-'A'+'a' )

/***
*int _tolower(c) - convert character to lower case
*
*Purpose:
*       _tolower() is simply a function version of the macro of the same name.
*
*Entry:
*       c - int value of character to be converted
*
*Exit:
*       returns int value of lower case representation of c
*
*Exceptions:
*
*******************************************************************************/

int __cdecl _tolower (
        int c
        )
{
        return(mklower(c));
}

/***
*int tolower(c) - convert character to lower case
*
*Purpose:
*       tolower() is simply a function version of the macro of the same name.
*
*Entry:
*       c - int value of character to be converted
*
*Exit:
*       if c is an upper case letter, returns int value of lower case
*       representation of c. otherwise, it returns c.
*
*Exceptions:
*
*******************************************************************************/


int __cdecl tolower (
        int c
        )
{
#if     !defined (_NTSUBSET_) && !defined(_POSIX_)

#ifdef  _MT
        pthreadlocinfo ptloci = _getptd()->ptlocinfo;

        if ( ptloci != __ptlocinfo )
            ptloci = __updatetlocinfo();

        return __tolower_mt(ptloci, c);
}

/***
*int __tolower_mt(c) - convert character to lower case
*
*Purpose:
*       Multi-thread function only!
*
*Entry:
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/

int __cdecl __tolower_mt (
        pthreadlocinfo ptloci,
        int c
        )
{

#endif  /* _MT */

        int size;
        unsigned char inbuffer[3];
        unsigned char outbuffer[3];

#ifndef  _MT
        if ( __lc_handle[LC_CTYPE] == _CLOCALEHANDLE ||
             (__lc_clike && (unsigned) c <= 0x7f))
            return __ascii_tolower(c);
#else
        if ( ptloci->lc_handle[LC_CTYPE] == _CLOCALEHANDLE ||
             (ptloci->lc_clike && (unsigned)c <= 0x7f) )
            return __ascii_tolower(c);
#endif

        /* if checking case of c does not require API call, do it */
        if ( (unsigned)c < 256 )
        {
#ifdef  _MT
            if ( !__isupper_mt(ptloci, c) )
#else
            if ( !isupper(c) )
#endif
            {
                return c;
            }
        }

        /* convert int c to multibyte string */
#ifdef  _MT
        if ( __isleadbyte_mt(ptloci, c >> 8 & 0xff) )
#else
        if ( isleadbyte(c >> 8 & 0xff) )
#endif
        {
            inbuffer[0] = (c >> 8 & 0xff); /* put lead-byte at start of str */
            inbuffer[1] = (unsigned char)c;
            inbuffer[2] = 0;
            size = 2;
        } else {
            inbuffer[0] = (unsigned char)c;
            inbuffer[1] = 0;
            size = 1;
        }

        /* convert to lowercase */
#ifdef  _MT
        if ( 0 == (size = __crtLCMapStringA( ptloci->lc_handle[LC_CTYPE],
#else
        if ( 0 == (size = __crtLCMapStringA( __lc_handle[LC_CTYPE],
#endif
                                             LCMAP_LOWERCASE,
                                             inbuffer, 
                                             size, 
                                             outbuffer, 
                                             3, 
#ifdef  _MT
                                             ptloci->lc_codepage,
#else
                                             __lc_codepage,
#endif
                                             TRUE)) )
        {
            return c;
        }

        /* construct integer return value */
        if (size == 1)
            return ((int)outbuffer[0]);
        else
            return ((int)outbuffer[1] | ((int)outbuffer[0] << 8));

#else

        return(isupper(c) ? mklower(c) : c);

#endif
}