CompareStringA.cpp File Reference

#include <corecrt_internal.h>

Include dependency graph for CompareStringA.cpp:

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Functions
static int __cdecl	InternalCompareStringA (_locale_t plocinfo, LPCWSTR LocaleName, DWORD dwCmpFlags, PCCH lpString1, int cchCount1, PCCH lpString2, int cchCount2, int code_page) throw ()
int __cdecl	__acrt_CompareStringA (_locale_t const locale, LPCWSTR const locale_name, DWORD const compare_flags, PCCH const string1, int const string1_count, PCCH const string2, int const string2_count, int const code_page)

Function Documentation

__acrt_CompareStringA()

int __cdecl __acrt_CompareStringA	(	_locale_t const	locale,
		LPCWSTR const	locale_name,
		DWORD const	compare_flags,
		PCCH const	string1,
		int const	string1_count,
		PCCH const	string2,
		int const	string2_count,
		int const	code_page
	)

Definition at line 209 of file CompareStringA.cpp.

{
    _LocaleUpdate locale_update(locale);
 
    return InternalCompareStringA(
        locale_update.GetLocaleT(),
        locale_name,
        compare_flags,
        string1,
        string1_count,
        string2,
        string2_count,
        code_page
        );
}

InternalCompareStringA()

static int __cdecl InternalCompareStringA ( _locale_t  plocinfo, LPCWSTR  LocaleName, DWORD  dwCmpFlags, PCCH  lpString1, int  cchCount1, PCCH  lpString2, int  cchCount2, int  code_page  ) throw ( )

static

Definition at line 41 of file CompareStringA.cpp.

{
    /*
     * CompareString will compare past nullptr. Must find nullptr if in string
     * before cchCountn chars.
     */
 
    if (cchCount1 > 0)
        cchCount1 = static_cast<int>(__strncnt(lpString1, cchCount1));
    else if (cchCount1 < -1)
        return FALSE;
 
    if (cchCount2 > 0)
        cchCount2 = static_cast<int>(__strncnt(lpString2, cchCount2));
    else if (cchCount2 < -1)
        return FALSE;
 
 
    int buff_size1;
    int buff_size2;
 
    /*
     * Use __lc_codepage for conversion if code_page not specified
     */
 
    if (0 == code_page)
        code_page = plocinfo->locinfo->_public._locale_lc_codepage;
 
    /*
     * Special case: at least one count is zero
     */
 
    if (!cchCount1 || !cchCount2)
    {
        unsigned char *cp;  // char pointer
        CPINFO cpInfo;      // struct for use with GetCPInfo
 
        /* both strings zero */
        if (cchCount1 == cchCount2)
            return 2;
 
        /* string 1 greater */
        if (cchCount2 > 1)
            return 1;
 
        /* string 2 greater */
        if (cchCount1 > 1)
            return 3;
 
        /*
         * one has zero count, the other has a count of one
         * - if the one count is a naked lead byte, the strings are equal
         * - otherwise it is a single character and they are unequal
         */
 
        if (GetCPInfo(code_page, &cpInfo) == FALSE)
            return 0;
 
        _ASSERTE(cchCount1==0 && cchCount2==1 || cchCount1==1 && cchCount2==0);
 
        /* string 1 has count of 1 */
        if (cchCount1 > 0)
        {
            if (cpInfo.MaxCharSize < 2)
                return 3;
 
            for ( cp = (unsigned char *)cpInfo.LeadByte ;
                  cp[0] && cp[1] ;
                  cp += 2 )
                if ( (*(unsigned char *)lpString1 >= cp[0]) &&
                     (*(unsigned char *)lpString1 <= cp[1]) )
                    return 2;
 
            return 3;
        }
 
        /* string 2 has count of 1 */
        if (cchCount2 > 0)
        {
            if (cpInfo.MaxCharSize < 2)
            return 1;
 
            for ( cp = (unsigned char *)cpInfo.LeadByte ;
                  cp[0] && cp[1] ;
                  cp += 2 )
                if ( (*(unsigned char *)lpString2 >= cp[0]) &&
                     (*(unsigned char *)lpString2 <= cp[1]) )
                    return 2;
 
            return 1;
        }
    }
 
    /*
     * Convert strings and return the requested information.
     */
 
    /* find out how big a buffer we need (includes nullptr if any) */
    if ( 0 == (buff_size1 = __acrt_MultiByteToWideChar( code_page,
                                                 MB_PRECOMPOSED |
                                                    MB_ERR_INVALID_CHARS,
                                                 lpString1,
                                                 cchCount1,
                                                 nullptr,
                                                 0 )) )
        return 0;
 
    /* allocate enough space for chars */
    __crt_scoped_stack_ptr<wchar_t> wbuffer1(_malloca_crt_t(wchar_t, buff_size1));
    if (wbuffer1.get() == nullptr)
        return 0;
 
    /* do the conversion */
    if ( 0 == __acrt_MultiByteToWideChar( code_page,
                                   MB_PRECOMPOSED,
                                   lpString1,
                                   cchCount1,
                                   wbuffer1.get(),
                                   buff_size1 ) )
        return 0;
 
    /* find out how big a buffer we need (includes nullptr if any) */
    if ( 0 == (buff_size2 = __acrt_MultiByteToWideChar( code_page,
                                                 MB_PRECOMPOSED |
                                                    MB_ERR_INVALID_CHARS,
                                                 lpString2,
                                                 cchCount2,
                                                 nullptr,
                                                 0 )) )
        return 0;
 
    /* allocate enough space for chars */
    __crt_scoped_stack_ptr<wchar_t> const wbuffer2(_malloca_crt_t(wchar_t, buff_size2));
    if (wbuffer2.get() == nullptr)
        return 0;
 
    int const actual_size = __acrt_MultiByteToWideChar(
        code_page,
        MB_PRECOMPOSED,
        lpString2,
        cchCount2,
        wbuffer2.get(),
        buff_size2);
 
    if (actual_size == 0)
        return 0;
 
    return __acrt_CompareStringEx(
        LocaleName,
        dwCmpFlags,
        wbuffer1.get(),
        buff_size1,
        wbuffer2.get(),
        buff_size2,
        nullptr,
        nullptr,
        0);
}

Referenced by __acrt_CompareStringA().