RFR: 8311102: Write annotations in the classfile dumped by SA

[Thomas Stuefe]

On Tue, 11 Jul 2023 06:31:24 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

>> Please review this PR that enables ClassWriter to write annotations to the class file being dumped.
>> 
>> The fields annotations are stored in `Annotations::_fields_annotations` which is of type `Array<Array<u1>*>`. There is no class in SA that can represent it. I have added ArrayOfU1Array to correspond to the type `Array<Array<u1>*>` and it works. I believe there are better approaches but that would require a bit more refactoring of the classes representing Array types. I will leave that for future work for now.
>> 
>> Testing: `test/hotspot/jtreg/serviceability/sa` and `test/jdk/sun/tools/jhsdb`
>> Tested it manually by dumping j.l.String class and comparing the annotations with the original class using javap.
>> The test case mentioned in [JDK-8311101](https://bugs.openjdk.org/browse/JDK-8311101) would provide better coverage.
>
> src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/oops/ConstMethod.java line 470:
> 
>> 468:       if (hasParameterAnnotations()) {
>> 469:         offset += 1;
>> 470:       }
> 
> Code here and in other places could be tightened:
> 
> 
> int offset = (hasMethodAnnotations() ? 1 : 0) + 
>                   (hasParameterAnnotations() ? 1 : 0) + 
>                   (hasTypeAnnotations() ? 1 : 0);

Possibly even factor it out into separate functions like  e.g. `offsetOfGenericSignatureIndex` does.

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PR Review Comment: https://git.openjdk.org/jdk/pull/14735#discussion_r1259254940