RFR: 8165276: Spec states to invoke the premain method in an agent class if it's public but implementation differs [v12]

[David Holmes]

On Fri, 22 Jan 2021 11:27:38 GMT, Serguei Spitsyn <sspitsyn at openjdk.org> wrote:

>> This change have been already reviewed by Mandy, Sundar, Alan and David.
>> Please, see the jdk 15 review thread:
>>   http://mail.openjdk.java.net/pipermail/serviceability-dev/2020-June/031998.html
>> 
>> Now, the PR approval is needed.
>> The push was postponed because the CSR was not approved at that time (it is now):
>>    https://bugs.openjdk.java.net/browse/JDK-8248189
>> Investigation of existing popular java agents was requested by Joe.
>> ----------
>> 
>> The java.lang.instrument spec:
>>   https://docs.oracle.com/en/java/javase/15/docs/api/java.instrument/java/lang/instrument/package-summary.html
>> 
>> Summary:
>>   The java.lang.instrument spec clearly states:
>>     "The agent class must implement a public static premain method
>>      similar in principle to the main application entry point."
>>   Current implementation of sun/instrument/InstrumentationImpl.java
>>   allows the premain method be non-public which violates the spec.
>>   This fix aligns the implementation with the spec.
>> 
>> Testing:
>>   A mach5 run of jdk_instrument tests is in progress.
>
> Serguei Spitsyn has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 12 additional commits since the last revision:
> 
>  - Merge
>  - 1. Prperly reverted fixes in 3 tests; 2. Got rid of <inherited> term in tests summary comment
>  - @summary of some negative tests is corrected
>  - 1. Suppress premain method check only if agent class is in unnamed module; 2. minor tests cleanup
>  - added to NegativeAgentRunner exit value check to be non-zero
>  - 1. Replaced AgentJarBuilder with JavaAgentBuilder; 2. Removed unneeded sun.tools.jar imports
>  - fixed trailing spaces
>  - (1) Update premain/agentmain method lookup; (2) refactored tests to get rid of shell scripts
>  - added 8165276 to @bug list of impacted tests
>  - (1)Fix comment in InstrumentationImpl; (2) Update agent super classes in tests with new expectations that premain methods in supers should non be called
>  - ... and 2 more: https://git.openjdk.java.net/jdk/compare/da29edf6...d926e4b1

Hi Serguei,

This seems good to go.

Thanks,
David

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

Marked as reviewed by dholmes (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/1694