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

[Gavin Ray]

On Mon, 5 Sep 2022 20:20:17 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

>> 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

Oh, well that'd make sense why it didn't work OOTB then, thanks for the info!

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