RFR (S): 8000232: NPG: SIGSEGV in Dependencies::DepStream::check_klass_dependency on solaris-x64

[Vladimir Ivanov]

Christian,

It's technically possible to store NULL in a dependency, but currently 
most of the callers expect non-null values to be returned.

Since Dependencies::DepStream::argument is a generic function to work 
with DepStream, which supports storing NULLs, I was reluctant to require 
non-null value.

Best regards,
Vladimir Ivanov

On 10/5/12 2:48 AM, Christian Thalinger wrote:
>
> On Oct 4, 2012, at 3:04 PM, Vladimir Ivanov <vladimir.x.ivanov at oracle.com> wrote:
>
>> http://cr.openjdk.java.net/~vlivanov/8000232/webrev.00
>> 22 lines changed: 10 ins; 4 del; 8 mod
>>
>> Context type of a dependency is encoded as NULL only when it is explicit and the context is "default" (see Dependencies::ctxk_encoded_as_null). Decoding takes place only in Dependencies::DepStream::context_type(), however the value is used in other places.
>>
>> The problem is that no decoding is performed when dependencies are logged using Dependencies::write_dependency_to, but only non-NULL values are expected in the code. The bug existed before NPG, it simply didn't cause a crash.
>>
>> Fixed by moving decoding into Dependencies::DepStream::argument, so no caller could see encoded context value (NULL) anymore.
>
> Is this assert still valid then?
>
>     assert(result == NULL || result->is_klass() || result->is_method(), "must be");
>
> -- Chris
>
>>
>> It also improves TraceDependencies & LogCompilation output: dependency context is always correctly displayed.
>>
>> Also, did some cleanup.
>>
>> Testing: failing test, JPRT w/ logging turned on & off, CTW on solaris_x64.
>>
>> Best regards,
>> Vladimir Ivanov
>