RFR: 8149591 - Prepare hotspot for GTest

[Stefan Karlsson]

On 2016-05-03 23:24, Kim Barrett wrote:
>> On May 3, 2016, at 3:57 PM, Stefan Karlsson <stefan.karlsson at oracle.com> wrote:
>>
>> Hi Kim,
>>
>> On 2016-05-03 21:20, Kim Barrett wrote:
>>>> On Apr 29, 2016, at 9:47 PM, Igor Ignatyev <igor.ignatyev at oracle.com> wrote:
>>>>
>>>> Hi,
>>>>
>>>> I’d like to renew this RFR.
>>>>
>>>> besides updated previous changes, new webrev contains two new things:
>>>> - new vm-flag — ExecutingUnitTests, we use it in debug jvm to print a clean error message (w/o assert, line, file, etc). it is needed to simplify comparing error message in “death” tests (the tests which intentionally cause crashes/asserts)
>>>> - if CreateCoredumpOnCrash is false, we don't determine default core path
>>>>
>>>> webrev: http://cr.openjdk.java.net/~iignatyev/8149591/webrev.00/
>>>> JBS: https://bugs.openjdk.java.net/browse/JDK-8149591
>>>>
>>>> Thanks,
>>>> — Igor
>>> Not a full review yet, but a question before I go on.
>>>
>>> I don’t understand the purpose of FormatBufferDummy.  I’m guessing it is to disambiguate the new
>>> FormatBuffer constructor taking a va_list argument.
>> Yes, that was the purpose.
>>
>>>    But with these two overloads:
>>>
>>>    FormatBuffer(const char* format, …);
>>>    FormatBuffer(const char* format, va_list ap);
>>>
>>> the latter should always be a better match when the second argument is a va_list, and should never
>>> be a match at all otherwise.  (An overload containing ellipsis is always the least good match.)  So I
>>> think we shouldn’t need FormatBufferDummy.
>>>
>> I started with that implementation but got the following error:
>>
>> src/share/vm/gc/shared/genCollectedHeap.cpp: In member function 'void GenCollectedHeap::do_collection(bool, bool, size_t, bool, GenCollectedHeap::GenerationType)':
>> src/share/vm/gc/shared/genCollectedHeap.cpp:435:44: error: deprecated conversion from string constant to 'va_list {aka char*}' [-Werror=write-strings]
>>      FormatBuffer<> gc_string("%s", "Pause ");
>>
>> So, adding FormatBufferDummy was a quick-n-dirty solution to fix this.
> va_list on this platform seems to be just a typedef for char*.
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33588
> which is “won’t fix”.  I hadn’t realized that overloading on va_list isn’t really useful;
> I guess that’s why there are lots of “v”-prefixed/suffixed operations around.  I can’t
> think of a better solution.  A comment would be nice.

Yes.

StefanK