REASSERT Code review request for 8012044: Give more information about self-suppression from Throwable.addSuppressed

[Joe Darcy]

Hi David,

On 04/22/2013 10:25 PM, David Holmes wrote:
> Hi Joe,
>
> On 23/04/2013 9:05 AM, Joseph Darcy wrote:
>> Hello,
>>
>> Just reasserting the request for a review of the latest version of this
>> patch:
>>
>>      http://cr.openjdk.java.net/~darcy/8012044.2
>>
>> I believe this version does an appropriate job of propagating exception
>> information when there is misuse of the methods on Throwable.
>
> I still find the use of addSuppressed in initCause to be questionable. 
> Given:
>
>    catch(SomeException s) {
>       sharedException.initCause(s); // oops already has a cause
>       throw sharedException;
>    }
>
> then the ISE isn't suppressing 's', but replacing/suppressing 
> sharedException in my view, as it is what would have been thrown had 
> the ISE not occurred.
>
> I understand the desire to not lose sight of the fact that 's' was 
> thrown, but this is really no different to a finally block losing the 
> original exception info. (And fixing that was rejected when the 
> suppression mechanism was added.)

Project Coin discussions did note try-catch-finally and 
try-with-resources were inconsistent on this point. While the 
try-with-resources behavior is regarded as preferable, we thought it 
would be too large a change to redefine the long-standing semantics of 
try-catch-finally.

>
> Anyway this isn't a "block" (not that such a thing exists), just a 
> comment. The change isn't harmful and may be useful.
>
> Cheers,
> David
>

Yes, I would describe the intention of this change as provding 
programmers more information to debug when the methods are Throwable and 
used improperly.

Thanks,

-Joe