RFR(M): 8201593: Print array length in ArrayIndexOutOfBoundsException.

[Stuart Monteith]

Hi,
  I'm trying to work through what's going on here. With C1 not
crashing, I'll check the behaviour of the interpreter and C2. I'm
doing explicitly with -Xint, etc.  WIth -Xint I definitely get the
error.

You have the condition the wrong way round -
_throw_index_out_of_bounds_exception is true when array is NULL.


BR,
   Stuart


On 19 April 2018 at 15:36, Lindenmaier, Goetz <goetz.lindenmaier at sap.com> wrote:
> Hi Stuart,
>
> thanks a lot for helping out here.
> I added below patch to my latest webrev (replaced it in-place):
> http://cr.openjdk.java.net/~goetz/wr18/8201593-lenInAIOOB/02/
>
> The remaining problem looks like the array argument does not
> reach the method that prints the message properly.
> Did I get a register wrong?
> Did I use a wrong argument register, or does the untangling
> of registers in overwrite something?
> Is it correct to use mov and not movw in templateInterpreterGenerator_aarch64.cpp?
> Is it safe to use r3 in templateTable_aarch64.cpp? (The "convention" here is stupid,
> it seems to cause unnecessary register moves. But it's similar on all platforms.)
>
> The test runs several times, assuring it's C1, C2 and Xint.
> This should help you to narrow down the problem.
>
> Best regards,
>   Goetz.
>
>
>
>
>
>
>
>
> diff -r 3fe33d48aa16 src/hotspot/cpu/aarch64/c1_CodeStubs_aarch64.cpp
> --- a/src/hotspot/cpu/aarch64/c1_CodeStubs_aarch64.cpp  Mon Apr 16 15:17:20 2018 +0200
> +++ b/src/hotspot/cpu/aarch64/c1_CodeStubs_aarch64.cpp  Thu Apr 19 16:06:23 2018 +0200
> @@ -73,9 +73,10 @@
>    } else {
>      __ mov(rscratch1, _index->as_jint());
>    }
> -  __ mov(rscratch2, _array->as_pointer_register());
>    Runtime1::StubID stub_id;
>    if (_throw_index_out_of_bounds_exception) {
> +    assert(_array != NULL, "sanity");
> +    __ mov(rscratch2, _array->as_pointer_register());
>      stub_id = Runtime1::throw_index_exception_id;
>    } else {
>      stub_id = Runtime1::throw_range_check_failed_id;
>
>
>
>
>> -----Original Message-----
>> From: Stuart Monteith [mailto:stuart.monteith at linaro.org]
>> Sent: Donnerstag, 19. April 2018 14:26
>> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>
>> Cc: hotspot-runtime-dev at openjdk.java.net; hotspot-compiler-
>> dev at openjdk.java.net; aarch64-port-dev at openjdk.java.net; aarch32-port-
>> dev at openjdk.java.net
>> Subject: Re: RFR(M): 8201593: Print array length in
>> ArrayIndexOutOfBoundsException.
>>
>> Hello Goetz,
>>    In c1_CodeStubs_aarch64.cpp, RangeCheckStub::emit_code you just
>> need to guard the emission of rscratch2 - you don't use it in one of
>> the cases, something like:
>>
>>      if (!_throw_index_out_of_bounds_exception) {
>>         __ mov(rscratch2, _array->as_pointer_register());
>>      }
>>
>>
>> Once I can run the unit tests, I'm seeing failures in your unit test like:
>>
>> java.lang.AssertionError: expected [trying to access index -5 of an
>> array with length 0] but found [trying to access index -5 of an array
>> with length -1459548190]
>>
>>
>> BR,
>>     Stuart
>>
>>
>> On 18 April 2018 at 09:09, Lindenmaier, Goetz <goetz.lindenmaier at sap.com>
>> wrote:
>> > Hi,
>> >
>> > I would like to print a more verbose text on ArrayIndexOutOfBounds
>> exception
>> > that not only mentions the index, but also the length of the array accessed.
>> > See the bug for documentation of the change of the message.
>> > http://cr.openjdk.java.net/~goetz/wr18/8201593-lenInAIOOB/01/
>> >
>> > @aarch/arm people:
>> > I edited the aarch/arm files. Could you please verify this is correct?
>> > I can not build on these platforms.
>> >
>> > The code on all the other platforms is tested with all the jtreg and jck tests
>> etc.
>> >
>> > Best regards,
>> >   Goetz.
>> >
>> >