RFR: 8335939: Hide element writing across the ClassFile API

[Adam Sotona]

On Tue, 16 Jul 2024 23:50:17 GMT, Chen Liang <liach at openjdk.org> wrote:

> `WritableElement` has always been one of the biggest peculiarities of ClassFile API: it exposes element writing yet has no corresponding reading ability exposed. Its existence creates a lot of API noise, increasing maintenance cost in the long run. (This is an iceberg whose tip was exposed in #14705)
> 
> Removal details:
> - `LocalVariable/LocalVariableType.writeTo`
> - `WritableElement`
> - In `BufWriter`:
>   - `writeList(List<WritableElement>)`
>   - `writeListIndices`: Hidden as we are not exposing `BoundAttribute.readEntryList`
>   - `writeBytes(BufWriter other)`
> - `ClassReader.compare`: Avoid reading from `BufWriter`
> 
> Future implementation cleanup out of scope of this patch:
> - Annotation writing can be upgraded and move away from `Util.Writable`
> - The writing of CP indices and attributes can move to their dedicated methods
> - reading of entry list can pair up with writing of entry list in ClassReader/BufWriter in future addition

src/java.base/share/classes/jdk/internal/classfile/impl/AnnotationReader.java line 287:

> 285:     public static void writeAnnotation(BufWriterImpl buf, Annotation annotation) {
> 286:         // handles annotations and type annotations
> 287:         // TODO annotation cleanup later

Do you have any specific annotation cleanup in mind?

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PR Review Comment: https://git.openjdk.org/jdk/pull/20205#discussion_r1680657521