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

[Erik Helin]

On 2015-03-24, Mikael Gerdin wrote:
> 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?

Looks good, Reviewed.

Thanks,
Erik

> /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