Unused code in prims/methodComparator

[Daniel D. Daugherty]

MethodComparator::methods_switchable() appears to be a day zero
function added by Misha Dmitriev back on 2000.10.23.


$ sgv src/share/vm/prims/methodComparator.cpp | grep 
MethodComparator::methods_switchable
1.17
1.1     bool MethodComparator::methods_switchable(methodOop old_method, 
methodOop new_method,
383 lines
No id keywords (cm7)

$ sp -r1.1 src/share/vm/prims/methodComparator.cpp
src/share/vm/prims/SCCS/s.methodComparator.cpp:

D 1.1 00/10/23 18:11:25 dmitriev 1 0    00366/00000/00000
MRs:
COMMENTS:
Class redefinition support - comparing methods of
class versions

Dan


On 2/4/16 8:30 PM, serguei.spitsyn at oracle.com wrote:
> Hi Thomas,
>
> The function MethodComparator::methods_switchable() was not used even 
> in the jdk 7.
> I do not know the history of this function and why its usage was dropped.
> Most likely, it was used initially as a part of the methods_EMCP() 
> algorithm.
> The SCCS history of the old changes was dropped when the repo was 
> moved under the Mercurial control.
>
> It seems safe to just remove it.
> We always can restore it from the hg history if necessary.
>
> Thanks,
> Serguei
>
>
> On 2/4/16 18:05, David Holmes wrote:
>> HI Thomas,
>>
>> Ultimately this is part of JVMTI so adding the serviceability folk.
>>
>> On 20/01/2016 6:31 PM, Thomas Stüfe wrote:
>>> Hi all,
>>>
>>> when investigating a warning about unchecked realloc() usage in
>>> methodComparator.hpp, I found that the offending function
>>> (BciMap::store_fragment_location) is not callable anymore.
>>>
>>> BciMap::store_fragment_location is called
>>> by MethodComparator::methods_switchable, which is not called anywhere.
>>>
>>> Is there any reason we should keep this?
>>
>> Certainly seems to be dead code. Unclear when/why redefinition 
>> dropped the notion of "switchable".
>>
>> Thanks,
>> David
>>
>>> Regards, Thomas
>>>
>