RFR 8204850: BarrierSet::make_* should be static

[Thomas Stüfe]

Seems fine.

Regards, Thomas

On Tue, Jun 12, 2018 at 8:39 AM, Aleksey Shipilev <shade at redhat.com> 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
>>
>
>