RFR: JDK-8315575: Retransform of record class with record component annotation fails with CFE [v3]

[Serguei Spitsyn]

On Thu, 14 Mar 2024 00:12:43 GMT, Alex Menkov <amenkov at openjdk.org> wrote:

>> The `attributute_count ` is a property of the `RecordComponent` even though it is not stored but calculated.
>> The `JvmtiClassFileReconstituter` should have a minimal knowledge about this property and how it is calculated, the same as any other consumer of the `RecordComponent`. Thre `RedefineClasses` in the future may need this number as well. Would it be also its responsibility to calculate it?
>
> `attributute_count` is a property of `component_info` Record's attribute in the class file (it contains length of the following `attribute_info_attributes` array).
> `RecordComponent` is VM representation of Record class attribute and contains data required by VM in a form that is useful for the VM.
> `RecordComponent` knows nothing `attribute_info_attributes` array, so it does not need to know its length.
> 
>  ClassFileParser parses `attribute_info_attributes` array and convert it to corresponding fields of `RecordComponent`.
> `JvmtiClassFileReconstituter` performs the reverse operation.
> They may have different `attributute_count` (that's what this bug about).
> If `RedefineClasses` needs the value, the code may be updated (it depends on what value it needs - from original class file or from reconstituted class file)

It does not matter what the `ClassFileParser` does.

> ` JvmtiClassFileReconstituter` performs the reverse operation.

True. It should know how to put the `attribute_count` value into the class file but it does not need to know how to calculate its value. What I do not like in your model is that there is no one single place which knows how to calculate this value and the existing and potential consumers should have this knowledge.

> They may have different `attributute_count `(that's what this bug about).

The bug is that the `attributute_count` field value from the class file stored in the `RecordComponent` does not match the calculated value because the invisible attribute was not saved (was ignored). My suggestion is not to store the `attributute_count` field value from the class file as it was before. The suggestion is to place the calculating function `attributute_count()` into the `RecordComponent` class.

>> Could you add a short comment, please?
>
> Added.

Thanks.

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PR Review Comment: https://git.openjdk.org/jdk/pull/18161#discussion_r1524116453
PR Review Comment: https://git.openjdk.org/jdk/pull/18161#discussion_r1524117292