clear() function potential bug

[Jerry Messina]

The clear() function seems to get confused sometimes when used with aliases...

Code: Select all

// this struct is 133 bytes total
public structure tdata_block_packet_t
    cmd         as byte
    len         as byte
    block_no    as word
    b(128)      as byte     // 128 byte data buffer
    eop         as byte
end structure

public structure cmd_packet_t
    tblock      as tdata_block_packet_t
end structure

public dim packet as cmd_packet_t

// create an alias for the 128-byte packet tblock data buffer 'b(128)'
dim rxb as packet.tblock.b


// now, these next two statements should do the same thing

// this clears 128 bytes (correct)
clear (packet.tblock.b)

// this clears 133 bytes (incorrect)
// it starts at the proper address, but has the length wrong
clear(rxb)

This should work, shouldn't it?

[David Barker]

Yes, it should work but clearly doesn't. I've uploaded a new BETA (B21) at the usual location. This will fix the problem.

It's a rather more difficult fix than the problem looks. Please let me know if B21 has side effects with any of your other programs.

[Jerry Messina]

>It's a rather more difficult fix than the problem looks

I can imagine. The actual code is more complex than the simple test case, and B21 worked with it. I ran a few other things through it and it didn't seem to cause any ill effects.

Thanks.

[David Barker]

It also impacted on SizeOf(), which should also now work OK.