RFR (XS) Enable -Woverloaded-virtual for GCC in the HotSpot build

[Mikael Gerdin]

Hi Volker,

On 2015-03-19 15:26, Volker Simonis wrote:
> Hi Mikael,
>
> the change looks good (and I think it is really reasonable to have
> this warning).
> I've also checked that our ancient gcc 4.1.2 already supports this option:)

Thanks!

Any more takers from HotSpot land?

/Mikael

>
> Regards,
> Volker
>
>
> On Thu, Mar 19, 2015 at 2:56 PM, Mikael Gerdin <mikael.gerdin at oracle.com> wrote:
>> Hi,
>>
>> I recently ran into a compiler warning which is enabled by default in
>> Solaris Studio, since HotSpot builds with warnings-as-errors this failed the
>> build only when I got to the Solaris build.
>> To catch this issue earlier for me (and a lot of others who use Linux as
>> their preferred development platform) I suggest that we enable the
>> equivalent warning for GCC.
>>
>> The patch to implement the change is inined below:
>>
>> diff --git a/make/linux/makefiles/gcc.make b/make/linux/makefiles/gcc.make
>> --- a/make/linux/makefiles/gcc.make
>> +++ b/make/linux/makefiles/gcc.make
>> @@ -207,7 +207,7 @@
>>     WARNINGS_ARE_ERRORS += -Wno-return-type -Wno-empty-body
>>   endif
>>
>> -WARNING_FLAGS = -Wpointer-arith -Wsign-compare -Wundef -Wunused-function
>> -Wunused-value -Wformat=2 -Wreturn-type
>> +WARNING_FLAGS = -Wpointer-arith -Wsign-compare -Wundef -Wunused-function
>> -Wunused-value -Wformat=2 -Wreturn-type -Woverloaded-virtual
>>
>>   ifeq ($(USE_CLANG),)
>>     # Since GCC 4.3, -Wconversion has changed its meanings to warn these
>> implicit
>>
>> I've verified the change by building on all linux platforms through JPRT.
>>
>> /Mikael