RFR: 8294972: Convert jdk.jlink internal plugins to use the Classfile API [v4]

[Adam Sotona]

On Fri, 10 Mar 2023 22:14:00 GMT, Mandy Chung <mchung at openjdk.org> wrote:

>> Adam Sotona has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 208 commits:
>> 
>>  - Merge branch 'master' into JDK-8294972-jlink-plugins
>>    
>>    # Conflicts:
>>    #	src/java.base/share/classes/module-info.java
>>  - Merge branch 'master' into JDK-8294972-jlink-plugins
>>  - fixed SystemModulesPlugin formatting
>>  - 8303624: The java.lang.Thread.FieldHolder can be null for JNI attaching threads
>>    
>>    Reviewed-by: alanb, dcubed
>>  - 8302360: Atomic*.compareAndExchange Javadoc unclear
>>    
>>    Reviewed-by: martin, dholmes
>>  - 8302779: HelidonAppTest.java fails with "assert(_cb == CodeCache::find_blob(pc())) failed: Must be the same" or SIGSEGV
>>    
>>    Reviewed-by: coleenp, sspitsyn
>>  - 8303691: Fedora based devkit build should load more packages from archive location
>>    
>>    Reviewed-by: mbaesken, erikj
>>  - 8303924: ProblemList serviceability/sa/UniqueVtableTest.java on Linux
>>    
>>    Reviewed-by: dcubed
>>  - 8303609: ProblemList serviceability/sa/TestSysProps.java with ZGC
>>    
>>    Reviewed-by: dcubed
>>  - 8289765: JDI EventSet/resume/resume008 failed with "ERROR: suspendCounts don't match for : VirtualThread-unparker"
>>    
>>    Reviewed-by: sspitsyn, kevinw
>>  - ... and 198 more: https://git.openjdk.org/jdk/compare/b1d89f30...cfc612ec
>
> src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/StripJavaDebugAttributesPlugin.java line 62:
> 
>> 60:                         // XXX. Do we have debug info? Is Asm ready for module-info?
>> 61:                     } else {
>> 62:                         byte[] content = newClassReader(path, resource, Classfile.Option.processDebug(false))
> 
> ASM `ClassReader.SKIP_DEBUG` flag indicates to skip  the SourceFile, SourceDebugExtension, LocalVariableTable, LocalVariableTypeTable, LineNumberTable and MethodParameters attributes.
> 
> `Classfile.Option.processDebug(false)` only skips LocalVariableTable, LocalVariableTypeTable, CHARACTER_RANGE_TABLE attributes.   To implement the same behavior as `SKIP_DEBUG`, it needs `Classfile.Option.processLineNumbers(false)` and skipping other attributes.

Right, I'll fix it, thanks.

> src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/VersionPropsPlugin.java line 158:
> 
>> 156:                                 });
>> 157:                             }
>> 158:                         });
> 
> Suggestion:
> 
>                         });
>                 } else {
>                     clb.with(cle);
> 
> 
> Other `ClassElement`s need to be added to the builder; otherwise they are dropped.  
> 
> One more thing I notice is that the attributes for example `LineNumberTable` attribute in `<clinit>` method after transformed are dropped.   But this plugin should only transform the code and leave everything else touched.

Yes, this transformation is incomplete and not using the latest Classfile API patterns.
I'll update it, thanks.

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

PR: https://git.openjdk.org/jdk/pull/12944