mblen.cpp File Reference

#include <corecrt_internal_mbstring.h>
#include <corecrt_internal_ptd_propagation.h>

Include dependency graph for mblen.cpp:

Go to the source code of this file.

Functions
static int __cdecl	_mblen_internal (char const *const string, size_t const max_count, __crt_cached_ptd_host &ptd)
int __cdecl	_mblen_l (char const *const string, size_t const max_count, _locale_t const locale)
int __cdecl	mblen (char const *const string, size_t const max_count)

Function Documentation

_mblen_internal()

static int __cdecl _mblen_internal ( char const *const  string, size_t const  max_count, __crt_cached_ptd_host &  ptd  )

static

Definition at line 19 of file mblen.cpp.

{
    mbstate_t internal_state{};
    if (!string || *string == '\0' || max_count == 0)
    {
        internal_state = {};
        return 0;
    }
 
    _locale_t const locale = ptd.get_locale();
 
    if (locale->locinfo->_public._locale_lc_codepage == CP_UTF8)
    {
        int result = static_cast<int>(__mbrtowc_utf8(nullptr, string, max_count, &internal_state, ptd));
        if (result < 0)
        {
            result = -1;
        }
        return result;
    }
 
    _ASSERTE(
        locale->locinfo->_public._locale_mb_cur_max == 1 ||
        locale->locinfo->_public._locale_mb_cur_max == 2);
 
    if (_isleadbyte_fast_internal(static_cast<unsigned char>(*string), locale))
    {
        _ASSERTE(locale->locinfo->_public._locale_lc_codepage != CP_UTF8 && L"UTF-8 isn't supported in this _mblen_l function yet!!!");
 
        // If this is a lead byte, then the codepage better be a multibyte codepage
        _ASSERTE(locale->locinfo->_public._locale_mb_cur_max > 1);
 
        // Multi-byte character; verify that it is valid:
        if (locale->locinfo->_public._locale_mb_cur_max <= 1)
        {
            return -1;
        }
 
        if (max_count > INT_MAX || static_cast<int>(max_count) < locale->locinfo->_public._locale_mb_cur_max)
        {
            return -1;
        }
 
        int const status = __acrt_MultiByteToWideChar(
            locale->locinfo->_public._locale_lc_codepage,
            MB_PRECOMPOSED | MB_ERR_INVALID_CHARS,
            string,
            locale->locinfo->_public._locale_mb_cur_max,
            nullptr,
            0);
 
        if (status == 0)
        {
            return -1;
        }
 
        return locale->locinfo->_public._locale_mb_cur_max;
    }
    else
    {
        // Single byte character; verify that it is valid:
        // CP_ACP is known to be valid for all values
        if (locale->locinfo->_public._locale_lc_codepage != CP_ACP)
        {
            int const status = __acrt_MultiByteToWideChar(
                locale->locinfo->_public._locale_lc_codepage,
                MB_PRECOMPOSED | MB_ERR_INVALID_CHARS,
                string,
                1,
                nullptr,
                0);
 
            if (status == 0)
            {
                return -1;
            }
        }
 
        return sizeof(char);
    }
}

Referenced by _mblen_l(), and mblen().

_mblen_l()

int __cdecl _mblen_l	(	char const *const	string,
		size_t const	max_count,
		_locale_t const	locale
	)

Definition at line 105 of file mblen.cpp.

{
    __crt_cached_ptd_host ptd(locale);
    return _mblen_internal(string, max_count, ptd);
}

mblen()

int __cdecl mblen	(	char const *const	string,
		size_t const	max_count
	)

Definition at line 117 of file mblen.cpp.

{
    __crt_cached_ptd_host ptd;
    return _mblen_internal(string, max_count, ptd);
}