JDK 9 RFR of JDK-8144321: Improve existent tests to check the exact line numbers in Stack Frame.

[Hamlin Li]

Hi Daniel,

Thanks for reviewing and suggestions, 1> add big warning to warn 
maintainer that the tests were dependent on line numbers.; 2> verify 
line numbers by parsing the source code. I think your second suggestion 
is great! :-), but to keep the logic simple and straight, I prefer your 
first suggestion which is to add big warning. When tests detect that 
line numbers are mismatched, there will be detailed error message 
explaining the reason.
webrev : http://cr.openjdk.java.net/~mli/8144321/webrev.01/

Thank you
-Hamlin

On 2015/12/5 18:35, Daniel Fuchs wrote:
> HI Hamlin,
>
> If I understand well any line, comment, etc, added to the test
> in the future is likely to make the tests fail because the line numbers
> will no longer match.
>
> I have seen other tests (I think they where compiler tests) which
> exhibited such a characteristic, but those had a big warning in
> their summary to warn maintainer that the tests were dependent
> on line numbers.
>
> If you can't find a way to make these test independent of
> line numbers, then at least there should be a big warning
> in the test summary, together with instruction on how to figure out
> which values to put in the annotation...
>
> One possibility to avoid having the test depend on hardcode line numbers
> could be to embed some logic in the test to make it process (read) its 
> own source
> file to discover the actual line numbers at run time and generate some 
> kind of
> data file/or static Map that StackFrameAnnotationUtil could in turn 
> read to get
> the expected line number.
> For instance, instead of embedding the real number, the annotation could
> embed an index, and the corresponding line could have a marker comment
> at the end referring to the index... e.g.:
>
> 93 @StackFrameAnnotation(lineNumbers = {1, 2})
> ...
>   
> 120 walker.walk(s -> { // should check this line number in 
> @StackFrameAnnotation.  // @LINE#1
> 121 s.filter(f -> f.getClassName().startsWith("AcrossThreads$"))
> 122 .forEach(f -> StackFrameAnnotationUtils.verifyLineNumber(
> 123 f.getClassName(),
> 124 f.getMethodName(),
> 125 f.getLineNumber().getAsInt()));
> 126 return null;
> 127 });
>   128             } else {
> 129 assertWalker(walker, n); // should check this line number in 
> @StackFrameAnnotation.  // @LINE#2
>   130             }
>
> The test could then first process its source file to figure out that @LINE#1 is at line 120 and
> @LINE#2 is at line 129, and then build a map { 1 -> 120, 2 -> 129 } which
> StackFrameAnnotationUtil would use to get the real line number from the index
> it finds in the annotation...
> Directly hardcoding line numbers inside annotations in the test looks 
> a bit fragile. Maybe someone else on the list will be able to suggest 
> even better ideas :-) best regards, -- daniel On 12/5/15 6:00 AM, 
> Hamlin Li wrote:
>> Hi all, Would you please help to review the test development of 
>> https://bugs.openjdk.java.net/browse/JDK-8144321. webrev : 
>> http://cr.openjdk.java.net/~mli/8144321/webrev.00/ Thank you -Hamlin