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

[Volker Simonis]

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:)

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