svn commit: r457438 - head/devel/ispc

[David Chisnall]

On 28 Dec 2017, at 16:55, Tijl Coosemans <tijl at FreeBSD.org> wrote:
> 
> On Thu, 28 Dec 2017 16:48:09 +0000 Alexey Dokuchaev <danfe at FreeBSD.org> wrote:
>> On Thu, Dec 28, 2017 at 01:36:31PM +0000, Alexey Dokuchaev wrote:
>>> On Thu, Dec 28, 2017 at 01:29:20AM -0800, Yuri wrote:  
>>>> On 12/27/17 23:14, Alexey Dokuchaev wrote:  
>>>>> But just couple of days ago X.org/Mesa had switched to 5.0, and
>>>>> I'm not sure what to do about this yet.  
>>>> 
>>>> Please feel free to further update ISPC's clang dependency if you feel
>>>> this is needed for embree.  
>>> 
>>> Yes, that's probably the most straight way forward.  I'm now (re)building
>>> all the ports involved (that might take some time on my slow hardware) to
>>> verify that CLANG_VERSION=50 does not cause regressions (vs. 40).  
>> 
>> We have a problem building `devel/ispc' againt LLVM 5.0:
>>  ...
>>  /usr/local/llvm50/lib/libLLVMSupport.a(Signals.cpp.o): In function `llvm::sys::PrintStackTrace(llvm::raw_ostream&)':
>>  /work/a/ports/devel/llvm50/work/llvm-5.0.0.src/lib/Support/Signals.cpp:(.text+0x20e0): undefined reference to `backtrace'
>>  clang-5.0: error: linker command failed with exit code 1 (use -v to seeinvocation)
>> 
>> It builds fine against LLVM 4.0.  Anyone got ideas (I'm too drunk to debug
>> this myself now) how do we proceed from here?
> 
> "backtrace" is provided by libexecinfo.

Note that recent versions of LLVM added a --system-libs flag to llvm-config.  On FreeBSD, this provides the relevant linker flags for adding libexecinfo.  Older projects may not have added this to their build systems and will find that things mostly work on Linux (I don’t think it adds anything for the most common build configurations).  The correct fix is likely to add this in the same place that they do llvm-config --libs --ldflags or similar.

David