[foreign-memaccess+abi] RFR: 8294621: Copying from a StringCharBuffer-backed MemorySegment results in crash [v2]

[Maurizio Cimadamore]

On Fri, 14 Oct 2022 12:07:03 GMT, Per Minborg <duke at openjdk.org> wrote:

>> This PR prevents `StringCharBuffer` arguments in `MemorySegment::ofBuffer`.
>
> Per Minborg has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Improve JavaDoc

src/java.base/share/classes/java/lang/foreign/MemorySegment.java line 945:

> 943:      * @throws IllegalArgumentException if the provided {@code buffer} is obtained by calling either
> 944:      *                                  ({@link CharBuffer#wrap(CharSequence)} or {@link CharBuffer#wrap(char[], int, int)}
> 945:      *                                  because these Buffer objects are not backed directly by a char array.

Suggestion:

     *                                  because these buffer objects are not backed directly by a char array.

src/java.base/share/classes/jdk/internal/foreign/AbstractMemorySegmentImpl.java line 474:

> 472:         // StringCharBuffer is packet-private
> 473:         if ("java.nio.StringCharBuffer".equals(bb.getClass().getName())) {
> 474:             throw new IllegalArgumentException("StringCharBuffer objects are not supported because they are not directly backed by a char[] array.");

Suggestion:

            throw new IllegalArgumentException("The provided CharBuffer is not backed by a char[]");

test/jdk/java/foreign/TestOfBufferIssue.java line 53:

> 51:     }
> 52: 
> 53: }

Watch out here missing newline

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PR: https://git.openjdk.org/panama-foreign/pull/741