C compiler issue perhaps?

[Doug Hardie]

There is no code running at that point.  Its just sitting there  
waiting for me to enter a gdb command.


On Mar 14, 2008, at 15:16, Derek Ragona wrote:

> At 05:10 PM 3/14/2008, Doug Hardie wrote:
>> I have a program I was testing with gdb.  I was trying to figure out
>> why c.rmonths was always zero when it should have been 6.  Stepped
>> through using the gdb n command.  Here is the output:
>>
>> (gdb)
>> 215                             c.rmonths = (edate - tdate) /  
>> toMONTHS;
>> (gdb)
>> 223                     c.dial_in = u.dial_in[0];
>> (gdb)
>> 224                     c.dsl = u.dsl[0];
>> (gdb) p c.rmonths
>> $1 = 0
>> (gdb) p c
>> $2 = {fa = 0, pwp = 0, disp_email = 0, imonths = 0, rmonths = 6,
>>   type = 73 'I', cd = 0 '\0', dial_in = 82 'R', dsl = 0 '\0',
>>   dsl_kit = 0 '\0', ip = 0 '\0', domain = 0 '\0', n_domain = 0 '\0',
>>   renewal = 89 'Y', program = "I\000\000"}
>> (gdb) p c->rmonths
>> $3 = 6
>> (gdb) p c.rmonths
>> $4 = 6
>>
>>
>> Notice, the first time i print it its zero.  The second time its 6.
>> What gives here?  I have seen this before but couldn't pin it down.
>> The program is not compiled with any optimization.  It is in a shared
>> library though.
>
> It is hard to tell without the code you used.  I would put some  
> printf's in the code and see what and when that variable gets set to  
> in actual running code.
>
>         -Derek
>
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