RFR: 8302491: NoClassDefFoundError omits the original cause of an error [v6]

[David Holmes]

On Tue, 7 Mar 2023 23:54:07 GMT, Ilarion Nakonechnyy <inakonechnyy at openjdk.org> wrote:

>> The proposed approach added a new function for getting the cause of an exception -`java_lang_Throwable::get_cause_simple `, that gets called within `InstanceKlass::add_initialization_error`  if an old one `java_lang_Throwable::get_cause_with_stack_trace` didn't succeed because of an exception during the VM call. The simple function doesn't call the VM for getting a stack trace but fills in any other information about an exception.
>> 
>> Besides that, the discovering information about an exception was added to `ConstantPoolCacheEntry::save_and_throw_indy_exc` function. 
>> 
>> Jtreg for reproducing the issue also was added to the commit. 
>> The commit was tested with tier1 tests.
>
> Ilarion Nakonechnyy has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Address a review notes

Two small adjustments needed and a couple of nits.

Thanks

src/hotspot/share/classfile/javaClasses.cpp line 2742:

> 2740:   // not keep classes alive in the stack trace.
> 2741:   // call this:  public StackTraceElement[] getStackTrace()
> 2742:   assert(throwable.not_null(), "shouldn't be");

You moved this assert but it needs to be before the first use of throwable()

src/hotspot/share/classfile/javaClasses.cpp line 2744:

> 2742:   // symbolic stacktrace of 'throwable'.
> 2743: 
> 2744:   // Now create the message with the original exception and thread name.

Existing: s/with/from/

src/hotspot/share/classfile/javaClasses.cpp line 2759:

> 2757:   Handle h_eiie = Exceptions::new_exception(current, exception_name, st.as_string());
> 2758:   // If new_exception returns a different exception while creating the exception,
> 2759:   // abandon the attempts to save the initialization error and return null.

Nit: s/attempts/attempt/

src/hotspot/share/oops/instanceKlass.cpp line 985:

> 983:   Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
> 984: 
> 985:   if ( init_error.is_null()) {

Nit: extra space after (

src/hotspot/share/oops/instanceKlass.cpp line 986:

> 984: 
> 985:   if ( init_error.is_null()) {
> 986:     log_trace(class, init)("Initialization error is null for class %s", external_name());

You need to move the ResourceMark from line 995 to line 984 to cover this new logging statement.

-------------

Changes requested by dholmes (Reviewer).

PR: https://git.openjdk.org/jdk/pull/12566