[oe] [meta-java] gcc6 support breaks build for gcc < 6

[Khem Raj]

On Mon, Jul 11, 2016 at 7:28 AM, Otavio Salvador
<otavio.salvador at ossystems.com.br> wrote:
> On Mon, Jul 11, 2016 at 11:24 AM, Khem Raj <raj.khem at gmail.com> wrote:
>> On Mon, Jul 11, 2016 at 6:19 AM, Otavio Salvador
>> <otavio.salvador at ossystems.com.br> wrote:
>>> Hello Dobbe,
>>>
>>> (Added Khem and Fabio on Cc)
>>>
>>> On Mon, Jul 11, 2016 at 8:37 AM, Winfried <winfried_mb2 at xmsnet.nl> wrote:
>>>> Commit  33ddb28a6428b02ddcc82d1954ecf27cd426fbb5 (openjdk-8: make GCC6
>>>> happy) adds gcc option -fno-lifetime-dse, which was added in gcc6. This
>>>> breaks the compilation of openjdk-native on hosts where gcc4 or gcc5 is the
>>>> default compiler.
>>>>
>>>> If this is intentional, I think the README file should mention that
>>>> meta-java requires gcc6. Better would be to add the '-fno-lifetime-dse'
>>>> option only if gcc >= 6 is used for native compilation (if that is
>>>> possible).
>>>
>>> This is a non-desired side effect of the patch. Daniel, could you take
>>> a look on this?
>>
>> If you are not using default compiler then you have to take some action
>>
>> add
>>
>> CFLAGS_remove = " -fno-tree-dse"
>> CXXFLAGS_remove = " -fno-tree-dse"
>>
>> via a .bbappend in your layer.
>
> Khem, this is for /native/ so it uses hosts GCC.

oh, in such a case, there are two options, one is to have this difference
detected during configuring and then not inject it via recipe

second is to have an utility in OE to detect the compiler version.
Which was posted in another thread