RFR: 8157490: null stream->source() no longer causes error with -Xlog:class+load

[Lois Foltan]

Thanks Max for implementing the suggestion.  Looks good.
Lois

On 5/31/2016 1:39 PM, Max Ockner wrote:
> I like this suggestion and I have updated my fix with it.
> webrev: http://cr.openjdk.java.net/~mockner/8157490.02/
> Thanks,
> Max
>
> On 5/26/2016 3:12 PM, Lois Foltan wrote:
>>
>> On 5/26/2016 2:07 PM, Max Ockner wrote:
>>> Hello,
>>>
>>> Please review this very small fix for class+load logging with modules.
>>>
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8157490
>>> Webrev: http://cr.openjdk.java.net/~mockner/8157490/
>>>
>>> Summary:  The JCK test 
>>> vm/jni/DefineClass/dfcl001/dfcl00101m1/dfcl00101m1 hit a SIGSEGV in 
>>> the logging section at the end of 
>>> ClassFileParser::fill_instance_klass(). With the addition of 
>>> modules, this logging section now uses
>>>
>>>     strlen(stream->source())
>>>
>>> to compute some of the module related parameters that it needs. This 
>>> SIGSEGV originated from the above line being executed with a null 
>>> stream source.
>>
>> Hi Max,
>>
>> I think you change is correct, but I would like to suggest changing 
>> the code even further.  Currently the code between line #5352-5360 
>> does a complicated check to see if the module's name is part of the 
>> java runtime image file and only sets the local variable 
>> "module_name" if it is.  So, only module names that are defined 
>> within the java runtime image file are printed out in the logging. We 
>> should print out all modules' names, not just the ones in the jimage 
>> file.  So please try removing lines #5352-5360 and set the local 
>> variable to:
>>
>>     const char* module_name = (module_entry->name() == NULL) ? 
>> UNNAMED_MODULE : module_entry->name()->as_C_string();
>>
>> The local variable "module_entry" is already checked at line #5310 to 
>> make sure it is set to a non-NULL value.
>>
>> Thanks,
>> Lois
>>
>>>
>>> Tested with vm/jni/DefineClass/dfcl001/dfcl00101m1/dfcl00101m1
>>>
>>> Thanks,
>>> Max
>>
>