RFR(XS): 8162670: make of jtreg_tests fails if no tests are run, causing jprt test runs to also fail

[Chris Plummer]

On 8/1/16 7:25 PM, David Holmes wrote:
> On 2/08/2016 12:11 PM, Chris Plummer wrote:
>> On 8/1/16 5:58 PM, David Holmes wrote:
>>> Hi Chris,
>>>
>>> On 2/08/2016 8:46 AM, Chris Plummer wrote:
>>>> Hello,
>>>>
>>>> Please review this simple change:
>>>>
>>>> https://bugs.openjdk.java.net/browse/JDK-8162670
>>>> http://cr.openjdk.java.net/~cjplummer/8162670/webrev-00/
>>>
>>> You've split a compound expression with your code:
>>>
>>>  227   jtregExitCode=$$? && \
>>>  228   if [ $${jtregExitCode} == 1 ]; then \
>>>  229     jtregExitCode=0; \
>>>  230   fi ; \
>>>  231   _summary="$(SUMMARY_TXT)"; \
>>>
>>> I'm not clear exactly why the && was needed here but rather than find
>>> out later I suggest rearranging the above to:
>>>
>>>    jtregExitCode=$$? && \
>>>    _summary="$(SUMMARY_TXT)"; \
>>>    if [ $${jtregExitCode} == 1 ]; then \
>>>      jtregExitCode=0; \
>>>    fi ; \
>>>
>> Yeah, that makes sense. I'll make the change. However, it's really
>> unclear what the use case for && is here. How can jtregExitCode=$$? ever
>> fail?
>
> I wonder if it evaluates to the $? value and so only sets _summary if 
> we had a zero exit code? (Not that I understand why we would only set 
> _summary in that context.)
I tried the following:

bash-4.1$ x=0 && echo "foo";

And "foo" is always printed. I also tried non-zero values for x. Here 
are some other examples:

bash-4.1$ (exit 1) && echo "foo"
bash-4.1$ (exit 0) && echo "foo"
foo

Commands evaluate to true if the exit status is 0, and false otherwise, 
so I guess you could say commands evaluate to !?$. For &&, the rhs is 
only executed if the lhs has a zero exit status.

Chris
>
> David
>
>> thanks,
>>
>> Chris
>>> Thanks,
>>> David
>>>
>>>> Note the copyright dates haven't been updated in this webrev, but I 
>>>> did
>>>> update them locally after noticing that.
>>>>
>>>> Tested with jprt test case given in the CR, and also with a jprt run
>>>> using "testset -hotspot" to make sure I didn't break anything.
>>>>
>>>> thanks,
>>>>
>>>> Chris
>>
>>