Bug in Norcroft v5.68?

Please check that I’m not going mad here…

  int i = 0;
  bool bDone = false;
  unsigned char uc = 0;
  char short_name[16] = "";
  char long_name[256] = "";

  // Clear the directory block offset and directory entry number
  *DirBlockOffset = 0;
  *DirEntry = 0;
  ReadBlock (offset_to_root_dir + *DirBlockOffset, da);
  print_block_data (*da);
  printf ("\n%02X %02X\n", ATTR_NON_RESERVED, ATTR_LONG_NAME);

  for (i = 0, bDone = false; (i < 16) & !bDone; i++)
  {
    uc = da->byte[i * 32];
    switch (uc)
    {
      case 0:
      printf ("%02X: Finished\n", uc);
      bDone = true;
      break;

      case 0xE5:
      printf ("%02X: Empty\n", uc);
      break;

      default:
      printf ("%02X: valid\n", uc);
      // Having found out that it is valid, we need to look
      // at the attributes to decide how to interpret it
      uc = da->byte[(i * 32) + 11];
      printf ("Attributes: %02X\n", uc);
      short_name[0] = '\0';
      long_name[0] = '\0';
      if ((uc & ATTR_NON_RESERVED) == ATTR_LONG_NAME)
      {
        printf ("This is a fragment of a long name: %02X %02X\n", uc & ATTR_NON_RESERVED, ATTR_LONG_NAME);
      }

      break;
    }
  }

3F 0F
44: valid
Attributes: 28
This is a fragment of a long name: 3E 0F
41: valid
Attributes: 0F
This is a fragment of a long name: 3F 0F
42: valid
Attributes: 00
This is a fragment of a long name: 3E 0F
41: valid
Attributes: 0F
This is a fragment of a long name: 3F 0F
52: valid
Attributes: 00
This is a fragment of a long name: 3E 0F
E5: Empty
E5: Empty
00: Finished

It isn’t ANDing with 0×3F, it’s ORing with 0×3E – and then it’s finding the result equal to 0×0F!

What’s going on?

Presumably my first action is to change the optimisation levels to see if that makes any difference?

First, shouldn’t you use a logic AND in the loop: for (i = 0, bDone = false; (i < 16) && !bDone; i++) but maybe this works also.

It looks like you defined ATTR_NON_RESERVED and ATTR_LONG_NAME but it is not in your samplecode.

I had substitution going wrong when I used something like:

The printing works but aritmatic can go wrong

is not the same as

Solution: use ( ) in the define.

Hope this helps, Peter V

Rats – caught by the preprocessor…

Thanks for your help, Peter, that’s fixed it.