/***
*a_cmp.c - A version of CompareString.
*
* Copyright (c) 1993-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Use either CompareStringA or CompareStringW depending on which is
* available
*
*Revision History:
* 09-14-93 CFW Module created.
* 09-17-93 CFW Use unsigned chars.
* 09-23-93 CFW Correct NLS API params and comments about same.
* 10-07-93 CFW Optimize WideCharToMultiByte, use NULL default char.
* 10-22-93 CFW Test for invalid MB chars using global preset flag.
* 11-09-93 CFW Allow user to pass in code page.
* 11-18-93 CFW Test for entry point function stubs.
* 02-23-94 CFW Use W flavor whenever possible.
* 03-31-94 CFW Include awint.h.
* 05-09-94 CFW Do not let CompareString compare past NULL.
* 06-03-94 CFW Test for empty string early.
* 11/01-94 CFW But not too early for MB strings.
* 12-21-94 CFW Remove invalid MB chars NT 3.1 hack.
* 12-27-94 CFW Call direct, all OS's have stubs.
* 01-10-95 CFW Debug CRT allocs.
* 02-06-95 CFW assert -> _ASSERTE.
* 02-15-97 RDK For narrow comparsion, try W version first so Windows NT
* can process nonANSI codepage correctly.
* 05-15-97 GJF Moved W version into another file, renamed this as
* a_cmp.c. Replaced use of _malloc_crt/_free_crt with
* _alloca. Also, detab-ed and cleaned up the code a bit.
* 05-27-98 GJF Changed strncnt() so that it will never examine the
* (cnt + 1)-th byte of the string.
* 08-18-98 GJF Use _malloc_crt if _alloca fails.
* 12-10-99 GB Added support for recovery from stack overflow around
* _alloca().
* 05-17-00 GB Use ERROR_CALL_NOT_IMPLEMENTED for existance of W API
* 08-23-00 GB Fixed bug with non Ansi CP on Win9x.
*
*******************************************************************************/
#include <cruntime.h>
#include <internal.h>
#include <dbgint.h>
#include <stdlib.h>
#include <setlocal.h>
#include <locale.h>
#include <awint.h>
#include <dbgint.h>
#include <malloc.h>
#include <awint.h>
#define USE_W 1
#define USE_A 2
/***
*int __cdecl strncnt - count characters in a string, up to n.
*
*Purpose:
* Internal local support function. Counts characters in string before NULL.
* If NULL not found in n chars, then return n.
*
*Entry:
* const char *string - start of string
* int n - byte count
*
*Exit:
* returns number of bytes from start of string to
* NULL (exclusive), up to n.
*
*Exceptions:
*
*******************************************************************************/
static int __cdecl strncnt (
const char *string,
int cnt
)
{
int n = cnt;
char *cp = (char *)string;
while (n-- && *cp)
cp++;
return cnt - n - 1;
}
/***
*int __cdecl __crtCompareStringA - Get type information about an ANSI string.
*
*Purpose:
* Internal support function. Assumes info in ANSI string format. Tries
* to use NLS API call CompareStringA if available and uses CompareStringW
* if it must. If neither are available it fails and returns 0.
*
*Entry:
* LCID Locale - locale context for the comparison.
* DWORD dwCmpFlags - see NT\Chicago docs
* LPCSTR lpStringn - multibyte string to be compared
* int cchCountn - char (byte) count (NOT including NULL)
* (-1 if NULL terminated)
* int code_page - for MB/WC conversion. If 0, use __lc_codepage
*
*Exit:
* Success: 1 - if lpString1 < lpString2
* 2 - if lpString1 == lpString2
* 3 - if lpString1 > lpString2
* Failure: 0
*
*Exceptions:
*
*******************************************************************************/
int __cdecl __crtCompareStringA(
LCID Locale,
DWORD dwCmpFlags,
LPCSTR lpString1,
int cchCount1,
LPCSTR lpString2,
int cchCount2,
int code_page
)
{
static int f_use = 0;
/*
* Look for unstubbed 'preferred' flavor. Otherwise use available flavor.
* Must actually call the function to ensure it's not a stub.
* (Always try wide version first so WinNT can process codepage correctly.)
*/
if (0 == f_use)
{
if (0 != CompareStringW(0, 0, L"\0", 1, L"\0", 1))
f_use = USE_W;
else if (GetLastError() == ERROR_CALL_NOT_IMPLEMENTED)
f_use = USE_A;
}
/*
* CompareString will compare past NULL. Must find NULL if in string
* before cchCountn chars.
*/
if (cchCount1 > 0)
cchCount1 = strncnt(lpString1, cchCount1);
if (cchCount2 > 0)
cchCount2 = strncnt(lpString2, cchCount2);
/* Use "A" version */
if (USE_A == f_use || f_use == 0)
{
char *cbuffer1 = NULL;
char *cbuffer2 = NULL;
int ret;
int AnsiCP;
if (0 == Locale)
Locale = __lc_handle[LC_CTYPE];
if (0 == code_page)
code_page = __lc_codepage;
if ( -1 == (AnsiCP = __ansicp(Locale)))
return FALSE;
/* If current CP is not ANSI CP for the given Locale, convert the
* string from current CP to ansi CP as CompareStringA uses
* ANSI CP to compare strings.
*/
if ( AnsiCP != code_page)
{
cbuffer1 = __convertcp(code_page,
AnsiCP,
lpString1,
&cchCount1,
NULL,
0);
if (cbuffer1 == NULL)
return FALSE;
cbuffer2 = __convertcp(code_page,
AnsiCP,
lpString2,
&cchCount2,
NULL,
0);
if (cbuffer2 == NULL)
{
_free_crt(cbuffer1);
return FALSE;
}
lpString1 = cbuffer1;
lpString2 = cbuffer2;
}
ret = CompareStringA( Locale,
dwCmpFlags,
lpString1,
cchCount1,
lpString2,
cchCount2 );
if ( cbuffer1 != NULL)
{
_free_crt(cbuffer1);
_free_crt(cbuffer2);
}
return ret;
}
/* Use "W" version */
if (USE_W == f_use)
{
int buff_size1;
int buff_size2;
wchar_t *wbuffer1;
wchar_t *wbuffer2;
int malloc_flag1 = 0;
int malloc_flag2 = 0;
int retcode = 0;
/*
* Use __lc_codepage for conversion if code_page not specified
*/
if (0 == code_page)
code_page = __lc_codepage;
/*
* Special case: at least one count is zero
*/
if (!cchCount1 || !cchCount2)
{
unsigned char *cp; // char pointer
CPINFO lpCPInfo; // 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, &lpCPInfo) == FALSE)
return 0;
_ASSERTE(cchCount1==0 && cchCount2==1 || cchCount1==1 && cchCount2==0);
/* string 1 has count of 1 */
if (cchCount1 > 0)
{
if (lpCPInfo.MaxCharSize < 2)
return 3;
for ( cp = (unsigned char *)lpCPInfo.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 (lpCPInfo.MaxCharSize < 2)
return 1;
for ( cp = (unsigned char *)lpCPInfo.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 NULL if any) */
if ( 0 == (buff_size1 = MultiByteToWideChar( code_page,
MB_PRECOMPOSED |
MB_ERR_INVALID_CHARS,
lpString1,
cchCount1,
NULL,
0 )) )
return 0;
/* allocate enough space for chars */
__try {
wbuffer1 = (wchar_t *)_alloca( buff_size1 * sizeof(wchar_t) );
}
__except( EXCEPTION_EXECUTE_HANDLER ) {
_resetstkoflw();
wbuffer1 = NULL;
}
if ( wbuffer1 == NULL ) {
if ( (wbuffer1 = (wchar_t *)_malloc_crt(buff_size1 * sizeof(wchar_t)))
== NULL )
return 0;
malloc_flag1++;
}
/* do the conversion */
if ( 0 == MultiByteToWideChar( code_page,
MB_PRECOMPOSED,
lpString1,
cchCount1,
wbuffer1,
buff_size1 ) )
goto error_cleanup;
/* find out how big a buffer we need (includes NULL if any) */
if ( 0 == (buff_size2 = MultiByteToWideChar( code_page,
MB_PRECOMPOSED |
MB_ERR_INVALID_CHARS,
lpString2,
cchCount2,
NULL,
0 )) )
goto error_cleanup;
/* allocate enough space for chars */
__try {
wbuffer2 = (wchar_t *)_alloca( buff_size2 * sizeof(wchar_t) );
}
__except( EXCEPTION_EXECUTE_HANDLER ) {
_resetstkoflw();
wbuffer2 = NULL;
}
if ( wbuffer2 == NULL ) {
if ( (wbuffer2 = (wchar_t *)_malloc_crt(buff_size2 * sizeof(wchar_t)))
== NULL )
goto error_cleanup;
malloc_flag2++;
}
/* do the conversion */
if ( 0 != MultiByteToWideChar( code_page,
MB_PRECOMPOSED,
lpString2,
cchCount2,
wbuffer2,
buff_size2 ) )
retcode = CompareStringW( Locale,
dwCmpFlags,
wbuffer1,
buff_size1,
wbuffer2,
buff_size2 );
if ( malloc_flag2 )
_free_crt(wbuffer2);
error_cleanup:
if ( malloc_flag1 )
_free_crt(wbuffer1);
return retcode;
}
else /* f_use is neither USE_A nor USE_W */
return 0;
}