[PATCH] tbb-backend effective target should check ability to link TBB

[François Dumont]

On 5/21/19 10:51 PM, Jonathan Wakely wrote:
> On 21/05/19 22:47 +0200, François Dumont wrote:
>> On 5/21/19 3:50 PM, Jonathan Wakely wrote:
>>> On 20/05/19 21:41 -0700, Thomas Rodgers wrote:
>>>> With the addition of "-ltbb" to the v3_target_compile flags (so as to,
>>>> you know, actually try to link tbb).
>>>>
>>>> Tested x86_64-linux, committed to trunk.
>>>
>>> This didn't work, I still get a FAIL for every pstl test when
>>> tbb.x86_64 and tbb-devel.x86_64 are installed but not tbb.i686.
>>>
>>> Adding -v to RUNTESTFLAGS shows -ltbb wasn't being added to the
>>> command, and because the test program didn't actually refer to any TBB
>>> symbols, it still linked successfully.
>>>
>> But the test program still do not refer any TBB symbol. Why is it 
>> better ?
>
> Because -ltbb means the linker will give an error if there is no
> suitable libtbb. That's true even if no symbols from it are needed.
> Try it.
>
Ok, good to know.

Thanks