RFR(M): 8165550: Add class loader names to ClassCastException message

[Lois Foltan]

On 11/14/2016 4:00 PM, Rachel Protacio wrote:
> New webrev: http://cr.openjdk.java.net/~rprotacio/8165550.01/

Hi Rachel,

Looks good.  One comment about hard coding the string "java.base" on 
line #1989.  Please consider obtaining the string for the java.base 
module from vmSymbols::java_base()->as_C_string().

Thanks,
Lois

>
> Corrected according to David's review. Comments below.
>
>
> On 11/10/2016 6:24 PM, David Holmes wrote:
>> Okay on with the review:
>>
>> src/share/vm/classfile/moduleEntry.cpp
>>
>> +     const char* loc = "";
>> +     loc = location()->as_C_string();
>>
>> can just be:
>>
>> +     const char* loc = location()->as_C_string();
>>
> Fixed.
>> ---
>>
>> src/share/vm/runtime/sharedRuntime.cpp
>>
>> 1941 const char* class_loader_and_module_name(Klass* klass, Klass* 
>> base_klass) {
>>
>> I'm unclear in what way "base_klass" is a "base" class ?? And why, if 
>> it is not an instance class must be it in java.base ??
> I really meant "bottom" class, following the logic used to parse it 
> out. I've moved that internal to the function now. So if the klass is 
> an instance klass or instance klass array, we look for further 
> information. Otherwise (if it's a primitive array), it's from java.base.
>>
>> Nit: I don't think these need to be #defines nor have such verbose 
>> names:
>>
>> 1936 #define CLASS_LOADER_NAME_DELIMITER "/"
>> 1937 #define CLASS_LOADER_NAME_DELIMITER_LENGTH 
>> strlen(CLASS_LOADER_NAME_DELIMITER)
>>
>> why not just
>>
>> const char* delim = "\";
>> int delim_len = strlen(delim);
>>
>> Plus you are inconsistent with the handling of the "/" delimiter 
>> versus the "@" delimiter.
> Fixed.
>>
>> ---
>>
>>  test/runtime/modules/CCE_module_msg.java
>>
>> Nit: in the catch block from line #95 can you store getMessage() into 
>> a local so it isn't called 5 times. Thanks. :)
> Fixed too. Thanks!
> Rachel
>>
>> Thanks,
>> David
>>
>>> Rachel
>>>
>>> On 11/10/2016 5:02 PM, David Holmes wrote:
>>>> Hi Rachel,
>>>>
>>>> Just wondering, in the most complex case, exactly what will this new
>>>> message look like? We seem to be including module names as well as
>>>> classloader names, and of course class names.
>>>>
>>>> Arguably we should only add the additional info when they differ
>>>> between the types ie if both in same classloader and same module then
>>>> only report class name; if same loader but different module report
>>>> module:class; if different loaders then report everything
>>>> loader:module:class. Also not sure module version is needed at all in
>>>> this message.
>>>>
>>>> Thanks,
>>>> David
>>>>
>>>> On 11/11/2016 7:38 AM, Rachel Protacio wrote:
>>>>> Hi,
>>>>>
>>>>> Please review this Jigsaw enhancement which adds the new format of 
>>>>> class
>>>>> loader names to VM ClassCastException messages. Includes an
>>>>> updated/expanded jtreg test.
>>>>>
>>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8165550
>>>>> Open webrev: http://cr.openjdk.java.net/~rprotacio/8165550.00/
>>>>>
>>>>> Passes JPRT and jck vm and lang tests.
>>>>>
>>>>> Thanks!
>>>>> Rachel
>>>
>