Request for reviews (XS): 7047069: Array can dynamically change size when assigned to an object field
vladimir.kozlov at oracle.com
Fri May 27 12:47:03 PDT 2011
Yes, removed BIG_NEG and used -1 in find_int_con()
Tom Rodriguez wrote:
> You don't really need BIG_NEG at all then.
> On May 27, 2011, at 12:34 PM, Vladimir Kozlov wrote:
>> I agree, I changed the code to check result of find_int_con(offset, BIG_NEG). Webrev is updated.
>> Tom Rodriguez wrote:
>>> On May 27, 2011, at 11:51 AM, Vladimir Kozlov wrote:
>>>> Fixed 7047069: Array can dynamically change size when assigned to an object field
>>>> I lost my faith in our testing :( This broken code was there for more then 3 years and nobody hit it?
>>>> The initialization of a newly-allocated array with arraycopy is broken when src and dest offsets are not constants. The typo in the code convert not constant offsets to constant 8: 12 + (-1)*4. So we generates copy from offset 8 which is array length and overwrite it and the rest of the beginning of the array.
>>> I don't really like the find_int_con idiom all that much and the usage here is too clever. It's much less clear than:
>>> if (src_offset->Opcode() == Op_ConI || dest_offset->Opcode() == Op_ConI)
>>> intptr_t src_off = abase + ((intptr_t) src_offset->find_int_con() << scale);
>>> intptr_t dest_off = abase + ((intptr_t) dest_offset->find_int_con() << scale);
>>> Anyway, your fix is good.
>>>> Added regression test.
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