RFR: 8346657: Improve out of bounds exception messages for MemorySegments

[Maurizio Cimadamore]

On Tue, 4 Nov 2025 09:17:27 GMT, Igor Rudenko <duke at openjdk.org> wrote:

> Add more precise message for IndexOutOfBoundsException in MemorySegment

src/java.base/share/classes/jdk/internal/foreign/AbstractMemorySegmentImpl.java line 433:

> 431: 
> 432:     private IndexOutOfBoundsException outOfBoundException(long offset, long length) {
> 433:         return new IndexOutOfBoundsException(String.format("Out of bound access on segment %s; " +

The new message looks ok, but note that this message is also reused by the `asSlice` methods. If we want to clarify the messages, perhaps we should think about rearranging the code a bit?

Related note: this is also why the routine that check OOB access needs to worry about `length` being zero -- because that's a valid value for `asSlice` (but not for access).

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PR Review Comment: https://git.openjdk.org/jdk/pull/28124#discussion_r2489522721