RFR: 8312522: Implementation of Foreign Function & Memory API [v21]

[Jorn Vernee]

On Wed, 13 Sep 2023 19:43:53 GMT, ExE Boss <duke at openjdk.org> wrote:

>> Jorn Vernee has updated the pull request incrementally with two additional commits since the last revision:
>> 
>>  - add missing space + reflow lines
>>  - Fix typo
>>    
>>    Co-authored-by: ExE Boss <3889017+ExE-Boss at users.noreply.github.com>
>
> src/java.base/share/classes/jdk/internal/foreign/abi/fallback/FallbackLinker.java line 311:
> 
>> 309:         };
>> 310: 
>> 311:         CANONICAL_LAYOUTS = Map.ofEntries(
> 
> `LibFallback::wcharSize()` and other getters for `LibFallback.NativeConstants` fields can throw an error when `LibFallback.SUPPORTED` is `false` due to the `fallbackLinker` library not being present, so this static initializer should be made into a method instead:
> Suggestion:
> 
>     static final Map<String, MemoryLayout> CANONICAL_LAYOUTS = initCanonicalLayouts();
> 
>     private static Map<String, MemoryLayout> initCanonicalLayouts() {
>         if (!isSupported()) {
>             return null;
>         }
> 
>         int wchar_size = LibFallback.wcharSize();
>         MemoryLayout wchartLayout = switch(wchar_size) {
>             case 2 -> JAVA_CHAR; // prefer JAVA_CHAR
>             default -> FFIType.layoutFor(wchar_size);
>         };
> 
>         return Map.ofEntries(

Good catch! I've chosen a slightly different solution though.

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PR Review Comment: https://git.openjdk.org/jdk/pull/15103#discussion_r1328794993