RFR: 8344165: Trace exceptions with a complete call-stack [v10]

[Coleen Phillimore]

On Fri, 20 Jun 2025 21:31:13 GMT, Ioi Lam <iklam at openjdk.org> wrote:

>> This PR makes it easier to analyze exceptions without modifying the JVM or the app to print call stacks:
>> 
>> Excerpt from the test case ExceptionsTest.java. 
>> 
>> 
>> [0.042s][info][exceptions] Exception <a 'java/lang/RuntimeException'{0x0000000474019530}: Test exception 1 for logging>
>> [                        ]  thrown in interpreter method <{method} {0x000079e52c4005b0} 'bar' '()V' in 'ExceptionsTest$InternalClass'>
>> [                        ]  at bci 9 for thread 0x000079e58c02c7b0 (main)
>> [0.042s][info][exceptions,stacktrace] Exception <a 'java/lang/RuntimeException'{0x0000000474019530}: Test exception 1 for logging>
>> [0.042s][info][exceptions,stacktrace] 	at ExceptionsTest$InternalClass.bar(ExceptionsTest.java:110)
>> [0.042s][info][exceptions,stacktrace] 	at ExceptionsTest$InternalClass.foo(ExceptionsTest.java:105)
>> [0.042s][info][exceptions,stacktrace] 	at ExceptionsTest$InternalClass.main(ExceptionsTest.java:100)
>> [0.042s][info][exceptions           ] Found matching handler for exception of type "java.lang.RuntimeException" in method "bar" at BCI: 10
>> Exception 1 caught.
>> 
>> 
>> - Note that the old `[exceptions]` log  is triggered by `InterpreterRuntime::exception_handler_for_exception()` and prints one level of the stack while the interpreter is looking for a handler. However, once a handler is found (inside `bar()`), the `[exceptions]` log terminates, and we do not know about the `foo()` or `main()` methods.
>> 
>> - The `[exceptions,stacktrace]` log is printed only when an exception is thrown:
>>     - By an `_athrow` bytecode. See comments around `Exceptions::log_exception_stacktrace(Handle exception, methodHandle method, int bci)`
>>     - By native code in Exceptions::special_exception() and  and Exceptions::_throw()).
>> 
>> **Concurrent Exceptions**
>> 
>> Neither the old  `[exceptions]` or the new `[exceptions,stacktrace]` logs distinguish between multiple exceptions that are thrown and handled concurrently. The users should use something like `-Xlog:exceptions,exceptions+stack::tags,tid` to include the thread ID into the log output, and use an external tool (such as a script) to demultiplex the logs.
>
> Ioi Lam has updated the pull request incrementally with one additional commit since the last revision:
> 
>   @coleenp comments; Also, use ProcessTools.executeProcess() to log the output in files

The !method->is_native() looks a bit strange to me but the whole change is okay.  I'd somewhat prefer all this commentary in the bug rather than the source code and would be happy to approve again if you move it there.

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Marked as reviewed by coleenp (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/25522#pullrequestreview-2947310272