RFR : JDK-8197439, , Crash with -XDfind=lambda for anonymous class in anonymous class.

Srikanth srikanth.adayapalam at oracle.com
Tue Feb 20 09:29:35 UTC 2018

On Friday 09 February 2018 03:01 PM, Jan Lahoda wrote:
> Hi,
> For certain classes -XDfind=lambda will crash javac (please see the 
> bug for details):

> ---
> The reason is that:
> - -XDfind=lambda will try to replace "new I1() {...}" with a lambda 
> and attribute that
> -but this will make I2 unresolvable
> -so Attr.visitNewClass will not (currently) attribute the inside of 
> the "new I2() {}".
> -so Attr.PostAttrAnalyzer will try to fill in Symbols and Types, but 
> "Attr.PostAttrAnalyzer.dummyMethodType" will dereference 
> MethodTree.restype, which is null for constructors (in this case an 
> automatically generated constructor).
> A part of the proposed fix is to enhance 
> PostAttrAnalyzer.dummyMethodType to handle constructors.

This part looks good.

> But attributing the body of an unresolvable anonymous class does not 
> seem difficult, and would help API clients like JShell, so the 
> proposed fix is doing that as well.

Not being a regular user of jshell, I am not able to form an assessment 
as to how important this is - my lay person's opinion is that it is not, 
but I will defer to your judgment. But the relevant changes in Attr look 


(1) FWIW, it may be a better idea to capture the diagnostic issued by 
XDfind=lambda and prepare a golden file ??
(2) @module directive unnecessary here ?

Overall, I am fine with this patch,

Sorry for the delayed response,

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