[UCRT] Import Microsoft.Windows.SDK.CRTSource version 10.0.22621.3

Imported from https://www.nuget.org/packages/Microsoft.Windows.SDK.CRTSource/10.0.22621.3
License: MIT

sdk/lib/ucrt/mbstring/mbsrev.cpp

@@ -0,0 +1,108 @@
+/***
+*mbsrev.c - Reverse a string in place (MBCS)
+*
+*       Copyright (c) Microsoft Corporation.  All rights reserved.
+*
+*Purpose:
+*       Reverse a string in place (MBCS)
+*
+*******************************************************************************/
+#ifndef _MBCS
+    #error This file should only be compiled with _MBCS defined
+#endif
+
+#include <corecrt_internal_mbstring.h>
+#include <locale.h>
+#include <string.h>
+
+
+/***
+* _mbsrev - Reverse a string in place (MBCS)
+*
+*Purpose:
+*       Reverses the order of characters in the string.  The terminating
+*       null character remains in place.  The order of MBCS characters
+*       is not changed.
+*
+*Entry:
+*       unsigned char *string = string to reverse
+*
+*Exit:
+*       returns string - now with reversed characters
+*
+*Exceptions:
+*       Input parameters are validated. Refer to the validation section of the function.
+*
+*******************************************************************************/
+
+extern "C" unsigned char * __cdecl _mbsrev_l(
+        unsigned char *string,
+        _locale_t plocinfo
+        )
+{
+        unsigned char *start = string;
+        unsigned char *left  = string;
+        unsigned char c;
+        _LocaleUpdate _loc_update(plocinfo);
+
+        /* validation section */
+        _VALIDATE_RETURN(string != nullptr, EINVAL, nullptr);
+
+        if (_loc_update.GetLocaleT()->mbcinfo->ismbcodepage == 0)
+            return (unsigned char *)_strrev((char *)string);
+
+
+        /* first go through and reverse the bytes in MBCS chars */
+        while ( *string ) {
+            if ( _ismbblead_l(*string++, _loc_update.GetLocaleT()) ) {
+                if ( *string ) {
+                    c = *string;
+                    *string = *(string - 1);
+                    *(string - 1) = c;
+                    string++;
+                }
+                else
+                {
+                    /*  second byte is EOS
+                        There is nothing really satisfying to do here. We have a string
+                        that ends in leadbyte,'\0'. Reversing this would lead to the leadbyte
+                        becoming falsely attached to the character before it:
+                        (XL0 -> LX0, X has suddenly become a trailbyte)
+
+                        So what we choose to do is assert and purge the dud byte from within the
+                        string.
+                    */
+                    errno = EINVAL;
+                    _ASSERTE(("Bad MBCS string passed into _mbsrev",0));
+
+                    /* String has at least moved once already, so this is safe */
+                    _ASSERTE(string>start);
+
+                    /* move back one to point at the dud leadbyte */
+                    --string;
+
+                    /* now truncate the string one byte earlier */
+                    *string='\0';
+
+                    break;
+                }
+            }
+        }
+
+        /* now reverse the whole string */
+        string--;
+        while ( left < string ) {
+            c = *left;
+            *left++ = *string;
+            *string-- = c;
+        }
+
+        return ( start );
+}
+
+extern "C" unsigned char * (__cdecl _mbsrev)(
+        unsigned char *string
+        )
+{
+    return _mbsrev_l(string, nullptr);
+}