[9] RFR(L) 8158168: SIGSEGV: CollectedHeap::fill_with_objects(HeapWord*, unsigned long, bool)+0xa8

[Vladimir Ivanov]

>> I have the same concern. Can we fix the immediate problem in 9 and
>> integrate verification logic in 10?
>>
>
> OK, Tobias is suggesting having verification logic only inside the
> intrinsics.  Are you suggesting removing that as well?

Yes and put them back in 10.

> I'm OK with removing all the verification, but that won't reduce the
> library changes much.  I could undo the renaming to Trusted.getChar, but
> we would still have the bounds checks moved into StringUTF16.

I suggest to go with a point fix for 9: just add missing range checks.

Is AbstractStringBuilder.append() the only affected method? (Sorry, it's 
hard to say exactly where the problem is by looking at the diff.)

I really like the refactoring you propose on jdk side, but there are 
pieces I'm not sure about. For example, I spotted a repeated range check:

jdk/src/java.base/share/classes/java/lang/AbstractStringBuilder.java:
     public void setCharAt(int index, char ch) {
         checkIndex(index, count);
         if (isLatin1() && StringLatin1.canEncode(ch)) {
             value[index] = (byte)ch;
         } else {
             if (isLatin1()) {
                 inflate();
             }
             StringUTF16.putCharSB(value, index, ch);
         }
     }

Best regards,
Vladimir Ivanov