Re: [PATCH 1/4] Move trace conditions tests from ftrace.exp to trace-condition.exp

[Antoine Tremblay <antoine dot tremblay at ericsson dot com>]

Pedro Alves writes:

> On 05/17/2016 06:03 PM, Antoine Tremblay wrote:
>> This patch moves conditional tests that were done in ftrace.exp to
>> trace-conditon.exp.
>
> Typo conditon.exp.
>

Fixed.

>> 
>> Note that emit_ref is now tested by the anarg local variable there is no
>> need to test the register directly.
>> 
>> The test coverage remains the same.
>
> How did you determine it that it's the same?

I've put an assert in each emit function and validated that they are all
called before / after the move.

>
> E.g., seems like the <, >, etc., conditions in ftrace.exp use a 
> global variable, while the trace-condition.exp ones use constants.
>

That is not a problem since testing with a constant tests the < >
on it's own.

The reading of global variable used in ftrace is tested separately in
trace-condition.exp.

> I also notice that all tests in trace-condition.exp expect 10 frames
> to be collected.  If a condition's handling is broken and the
> tracepoints ends up unconditional, will we ever notice?
>

That's a good point, that was pre-existing in trace-condition.exp I
think it's mitigated partially by counter-cases like:

test_tracepoints $trace_command "21 == 21" 10
test_tracepoints $trace_command "21 != 42" 10

But could be a problem with conditions like:
test_tracepoints $trace_command "(0xabababab & 0x0000ffff) == 0xabab" 10

It could add counter cases to all true/false tests like :

test_tracepoints $trace_command "(0xabababab & 0x0000ffff) == 0xffff" 0

And do that for the others.

> Seems like we have counter-cases using the same operators
> but that eval false, like (relative to your patch):
>

Yes indeed, as above. I'll do that in a patch preceding this one that
will change the existing trace-condition.exp first.

Thanks,
Antoine