[9] RFR (S): Class.getSimpleName() should work for non-JLS compliant class names

David Holmes david.holmes at oracle.com
Thu Apr 9 02:52:15 UTC 2015

Hi Vladimir,

On 9/04/2015 1:41 AM, Vladimir Ivanov wrote:
> http://cr.openjdk.java.net/~vlivanov/8057919/webrev.00/jdk
> http://cr.openjdk.java.net/~vlivanov/8057919/webrev.00/hotspot
> https://bugs.openjdk.java.net/browse/JDK-8057919
> The logic to compute simple name (Class.getSimpleName()) for
> inner/nested/local classes is tightly coupled with Java naming scheme
> and sometimes fails for classes generated from non-Java code.

Meta-question: if this is non-Java code then what does/should 
"simpleName" even mean? "Returns the simple name of the underlying class 
as given in the source code." If there is no (java) source code does 
this have any meaning? Should it return "" ?

> Instead of parsing class name and try to extract simple name based on
> JLS rules, the fix I propose is to use InnerClasses attribute from the
> class file. Simple name is already recorded there.
> JVMS-4.7.6: The InnerClasses Attribute
> "inner_name_index: If C is anonymous (JLS §15.9.5), the value of the
> inner_name_index item must be zero. Otherwise, the value of the
> inner_name_index item must be a valid index into the constant_pool
> table, and the entry at that index must be a CONSTANT_Utf8_info
> structure (§4.4.7) that represents the original simple name of C, as
> given in the source code from which this class file was compiled."
> Since I consider backporting the fix into 8u60, I'd like to hear
> opinions about backward compatibility of such change.
> As an alternative solution, I can restore original logic and consult
> InnerClasses attribute when class name parsing logic fails.

I think I'd prefer to see the VM call only used as a fallback if the 
regular parsing fails. That would prevent any compatibility issues for 
the 8u backport (ignoring tests that deliberately generate invalidly 
named classes).


> Testing: regression test, jck-runtime/java_lang, jdk/test/java/lang/
> Thanks!
> Best regards,
> Vladimir Ivanov

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