RFR 8204850: BarrierSet::make_* should be static

[Thomas Schatzl]

Hi,

  looks good.

Thomas

On Tue, 2018-06-12 at 08:39 +0200, Aleksey Shipilev wrote:
> (resending with proper To: field)
> 
> On 06/12/2018 08:38 AM, Aleksey Shipilev wrote:
> > RFE:
> >   https://bugs.openjdk.java.net/browse/JDK-8204850
> > 
> > In Epsilon, we have the call like:
> > 
> > EpsilonBarrierSet::EpsilonBarrierSet() : BarrierSet(
> >           make_barrier_set_assembler<BarrierSetAssembler>(),
> >           make_barrier_set_c1<BarrierSetC1>(),
> >           make_barrier_set_c2<BarrierSetC2>(),
> >           BarrierSet::FakeRtti(BarrierSet::EpsilonBarrierSet)) {};
> > 
> > ...and some compilers (notably Mac OS builds) complain that:
> > 
> > /Users/yosemite/jdk-
> > sandbox/src/hotspot/share/gc/epsilon/epsilonBarrierSet.cpp:40:11:
> > error: base
> > class 'BarrierSet' is uninitialized when used here to access
> > 'BarrierSet::make_barrier_set_assembler<BarrierSetAssembler>' [-
> > Werror,-Wuninitialized]
> >           make_barrier_set_assembler<BarrierSetAssembler>(),
> >           ^
> > 
> > This warning is legit: we are calling instance method of BarrierSet
> > before initializing it. But,
> > those methods are just factory methods, and they could be static,
> > resolving the warning.
> > 
> > Fix:
> > 
> > diff -r 7f166e010af4 src/hotspot/share/gc/shared/barrierSet.hpp
> > --- a/src/hotspot/share/gc/shared/barrierSet.hpp	Mon Jun 11
> > 22:35:07 2018 -0400
> > +++ b/src/hotspot/share/gc/shared/barrierSet.hpp	Tue Jun 12
> > 08:34:40 2018 +0200
> > @@ -103,17 +103,17 @@
> >    ~BarrierSet() { }
> > 
> >    template <class BarrierSetAssemblerT>
> > -  BarrierSetAssembler* make_barrier_set_assembler() {
> > +  static BarrierSetAssembler* make_barrier_set_assembler() {
> >      return NOT_ZERO(new BarrierSetAssemblerT()) ZERO_ONLY(NULL);
> >    }
> > 
> >    template <class BarrierSetC1T>
> > -  BarrierSetC1* make_barrier_set_c1() {
> > +  static BarrierSetC1* make_barrier_set_c1() {
> >      return COMPILER1_PRESENT(new BarrierSetC1T())
> > NOT_COMPILER1(NULL);
> >    }
> > 
> >    template <class BarrierSetC2T>
> > -  BarrierSetC2* make_barrier_set_c2() {
> > +  static BarrierSetC2* make_barrier_set_c2() {
> >      return COMPILER2_PRESENT(new BarrierSetC2T())
> > NOT_COMPILER2(NULL);
> >    }
> > 
> > 
> > Testing: x86_64 build, Epsilon MacOS build
> > 
> > Thanks,
> > -Aleksey
> > 
> 
>