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

[Stuart Monteith]

Hello Goetz,
   It appears that it is just C1 that exhibits the problem - there has
been a delay as I've been investigating a hang in Java JDK running
some of my automation.

I'll try and track down the issue. Otherwise, I do like the principle
of the patch.

BR,
    Stuart


On 24 April 2018 at 11:44, Lindenmaier, Goetz <goetz.lindenmaier at sap.com> wrote:
> Hi Stuart,
>
> could you track down the remaining issue?
>
> Best regards,
>   Goetz.
>
>> -----Original Message-----
>> From: Stuart Monteith [mailto:stuart.monteith at linaro.org]
>> Sent: Donnerstag, 19. April 2018 17:09
>> 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.
>>
>> 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.
>> >> >
>> >> >