RFR: JDK-8248641: Trees.getScope returns incorrect results for code inside a rule case

Vicente Romero vicente.romero at oracle.com
Mon Jul 27 17:09:09 UTC 2020


looks good, but shouldn't the test include cases for which the body is 
not null?

Vicente

On 7/27/20 8:46 AM, Jan Lahoda wrote:
> Hi,
>
> The existing patch is always filling out the JCCase.body, even for 
> statement cases (unlike the parser, which leaves the body empty/null 
> for statement cases). While I don't think there's anything directly 
> broken by this, it may be better to keep JCCase.body null for 
> statement cases to keep consistency with the normal non-copied trees.
>
> Updated patch:
> http://cr.openjdk.java.net/~jlahoda/8248641/webrev.01/
>
> What do you think?
>
> Thanks,
>     Jan
>
> On 07. 07. 20 21:15, Vicente Romero wrote:
>> looks good,
>> Vicente
>>
>> On 7/2/20 9:11 AM, Jan Lahoda wrote:
>>> Hi,
>>>
>>> When calling Trees.getScope for a TreePath that is inside a rule 
>>> case (i.e. "case ->"), the results are wrong/do not reflect the 
>>> elements declared inside the enclosing method.
>>>
>>> The reason is that, for rule cases, JCCase tree is keeping "body", 
>>> which represents what is in the source code. And this body is 
>>> wrapped and put into "stats", which are basically the statements for 
>>> an ordinary case. This means that javac can typically only work over 
>>> the "stats". When TreeCopied copies the JCCase tree, it will 
>>> duplicate both "stats" and "body" separately, leading to a 
>>> duplication in trees. And then Attr.breakTree points to the 
>>> requested tree from "body", but that one is never attributed, and so 
>>> the appropriate scope is never captured.
>>>
>>> The proposed patch here is to only duplicate "stats", and then take 
>>> appropriate "body" from "stats", leading to only one copy of the tree.
>>>
>>> Webrev:
>>> http://cr.openjdk.java.net/~jlahoda/8248641/webrev.00/
>>>
>>> JBS:
>>> https://bugs.openjdk.java.net/browse/JDK-8248641
>>>
>>> How does this look?
>>>
>>> Thanks,
>>>     Jan
>>



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