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

[Lindenmaier, Goetz]

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.
> >
> >