text: // Licensed to the .NET Foundation under one or more agreements.
  // The .NET Foundation licenses this file to you under the MIT license.
  
  /***
  *tmakepath_s.inl - general implementation of _tmakepath_s
  *
  
  *
  *Purpose:
  *       This file contains the general algorithm for _makepath_s and its variants.
  *
  *******************************************************************************/
  
  _FUNC_PROLOGUE
  errno_t __cdecl _FUNC_NAME(__out_ecount_z(_SIZE) _CHAR *_DEST, __in_opt size_t _SIZE, __in_z_opt const _CHAR *_Drive, __in_z_opt const _CHAR *_Dir, __in_z_opt const _CHAR *_Filename, __in_z_opt const _CHAR *_Ext)
  {
      size_t written;
      const _CHAR *p;
      _CHAR *d;
  
      /* validation section */
      _VALIDATE_STRING(_DEST, _SIZE);
  
      /* copy drive */
      written = 0;
      d = _DEST;
      if (_Drive != NULL && *_Drive != 0)
      {
          written += 2;
          if(written >= _SIZE)
          {
              goto error_return;
          }
          *d++ = *_Drive;
          *d++ = _T(':');
      }
  
      /* copy dir */
      p = _Dir;
      if (p != NULL && *p != 0)
      {
          do {
              if(++written >= _SIZE)
              {
                  goto error_return;
              }
              *d++ = *p++;
          } while (*p != 0);
  
          p--;
          if (*p != _T('/') && *p != _T('\\'))
          {
              if(++written >= _SIZE)
              {
                  goto error_return;
              }
              *d++ = _T('\\');
          }
      }
  
      /* copy fname */
      p = _Filename;
      if (p != NULL)
      {
          while (*p != 0)
          {
              if(++written >= _SIZE)
              {
                  goto error_return;
              }
              *d++ = *p++;
          }
      }
  
      /* copy extension; check to see if a '.' needs to be inserted */
      p = _Ext;
      if (p != NULL)
      {
          if (*p != 0 && *p != _T('.'))
          {
              if(++written >= _SIZE)
              {
                  goto error_return;
              }
              *d++ = _T('.');
          }
          while (*p != 0)
          {
              if(++written >= _SIZE)
              {
                  goto error_return;
              }
              *d++ = *p++;
          }
      }
  
      if(++written > _SIZE)
      {
          goto error_return;
      }
      *d = 0;
      _FILL_STRING(_DEST, _SIZE, written);
      _RETURN_NO_ERROR;
  
  error_return:
      _RESET_STRING(_DEST, _SIZE);
      _RETURN_BUFFER_TOO_SMALL(_DEST, _SIZE);
  
      /* should never happen, but compiler can't tell */
      return EINVAL;
  }
  