RFR(M/L) : 8209611 : use C++ compiler for hotspot tests

[David Holmes]

Hi Igor,

On 22/08/2018 9:04 AM, Igor Ignatyev wrote:
> http://cr.openjdk.java.net/~iignatyev//8209611/webrev.02/index.html 
> <http://cr.openjdk.java.net/%7Eiignatyev//8209611/webrev.02/index.html> is 
> a new version of patch, which moves only vmTestbase tests.

This seems okay in principle. I didn't verify all the mechanical changes 
individually.

make/common/TestFilesCompilation.gmk

I suspect you can just find all .c and .cpp files and process them 
together, rather than duplicate all the logic. But I'll leave that to 
Magnus to comment on.

make/test/JtregNativeHotspot.gmk

+ BUILD_HOTSPOT_JTREG_LIBRARIES_CFLAGS := -D__STDC_FORMAT_MACROS 
-D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS

Just a note that defining these is obsolete once we use C11/C++11 - 
which I think is an intent for JDK 12 if possible.

---

  test/hotspot/jtreg/vmTestbase/gc/g1/unloading/libdefine.cpp

   #ifdef __cplusplus
! #define JNI_ENV_ARG(x, y) y
   #define JNI_ENV_PTR(x) x
   #else
   #define JNI_ENV_ARG(x, y) x , y
   #define JNI_ENV_PTR(x) (*x)
   #endif

If this is now a C++ source file why do you a still have the code that 
allows for either C or C++? Is this stuff that will be cleaned up in the 
later RFE?

---

The switch to C++ means a lot of code now needs:

+ #ifdef __cplusplus
+ extern "C" {
+ #endif

I still have to wonder whether it better to leave these as C tests and 
only convert to C++ as and when needed ... seems like so much work.

Anyway I'm off on vacation after today so I'll leave it to others to 
take this up.

Thanks,
David

> Thanks,
> -- Igor
> 
>> On Aug 20, 2018, at 11:07 PM, Igor Ignatyev <igor.ignatyev at oracle.com 
>> <mailto:igor.ignatyev at oracle.com>> wrote:
>>
>>>> It has been discussed (not widely enough and I accept that) in 
>>>> 8209547 and the related email thread b/w JC(cc'ed) and myself.
>>>> as I said, I might went a way too far, so I'll revert changes in the 
>>>> non-vmTestbase tests and made appropriate changes in makefiles. what 
>>>> do you think?
>>>
>>> I think I need to see what you mean exactly :)
>> sure, it will take some time for me to do that, hopefully will upload 
>> new webrevs tomorrow morning PT. but the basic idea is to leave files 
>> in test/hotspot/jtreg/compiler, runtime, gc, native_sanity, 
>> serviceability, testlibrary as .c files, exactly as they were before, 
>> and restore corresponding filenames in make/test/JtregNativeHotspot.gmk.
>