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/***
*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;}
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