Graham Bloice wrote:
Any idea why the OSX compilers are complaining about this code in
packet-dnp.c:
if (!header_only || al_objq_index > 0) {
start_offset = offset;
for (item_num = 0; item_num < num_items; item_num++)
{
/* Create Point item and Process Index */
if (AL_OBJQL_IDX_NI <= al_objq_index && al_objq_index <=
AL_OBJQL_IDX_4O) <---------- Error here
[...]
The reported error is:
packet-dnp.c: In function 'dnp3_al_process_object':
packet-dnp.c:1566: warning: comparison is always true due to limited range of data type
The variable (al_objq_index) is three bits so has a value between 0 and
7 and the constants are enumerations of the values. AL_OBJQL_IDX_NI is
0 and AL_OBJQL_IDX_4O is 3. I suspect that the following if() might
also error out as it just checks for a different range of values (4-6).
The problem is that al_objq_index is a guint8 and AL_OBJQL_IDX_NI is
0x0. Since an unsigned variable can't go negative, al_objq_index is
ALWAYS greater than AL_OBJQL_IDX_NI (0).
From quickly looking at the code, I'd guess that this comparison can
simply be removed.