[foreign-memaccess+abi] RFR: 8291639: Improve the ability to visualize a MemorySegment in human readable forms [v17]

[Maurizio Cimadamore]

On Mon, 5 Sep 2022 18:12:45 GMT, Gavin Ray <duke at openjdk.org> wrote:

>> Per Minborg has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Update MemoryInspection JavaDoc
>
> src/java.base/share/classes/java/lang/foreign/MemoryInspection.java line 187:
> 
>> 185:          * @return rendered String
>> 186:          */
>> 187:         default String render(ValueLayout.OfAddress addressLayout, MemorySegment value) {
> 
> I think you can make it take `Addressable` so it works for both `MemorySegment` and `MemoryAddress`:
> 
> 
> default String render(ValueLayout.OfAddress addressLayout, Addressable value) {
>     requireNonNull(addressLayout);
>     return String.format("0x%0" + (ValueLayout.ADDRESS.byteSize() * 2) + "X", value.address());
> }
> 
> 
> In JDK 20 release I get an error:
> ![image](https://user-images.githubusercontent.com/26604994/188499156-a1c19a0d-cdea-430d-8866-7f99e0fe7f8b.png)
> 
> 
> Trying to do `(MemorySegment)` cast fails:
> 
> ![image](https://user-images.githubusercontent.com/26604994/188499194-0e319c83-ee4d-4ff4-969f-f5ff2ca82587.png)
> 
> But if I make it take `Addressable` instead, then it works:
> ![image](https://user-images.githubusercontent.com/26604994/188499260-2e86662c-d317-43c8-a94d-ea8695de75e3.png)

Note that the API in the Panama repo is different - MemoryAddress (and Addressable) have been removed as part of:
https://github.com/openjdk/panama-foreign/pull/694

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

PR: https://git.openjdk.org/panama-foreign/pull/695