> -----Original Message----- > From: Sebastian Huber [mailto:sebastian.hu...@embedded-brains.de] > Sent: Wednesday, March 01, 2017 7:47 AM > To: Sommer, Jan; devel@rtems.org > Subject: Re: Undefined reference to `__sync_bool_compare_and_swap_4' for > some Leon configurations with gfortran [...] > > I updated the __sync-check of libbacktrace and now the undefined references > are gone and my test program compiles. > > If there are no objections I would try to push something like the attached > patch upstream. Do you have any suggestions to which branches? > > I thought about trunk and the gcc-6 branch or do we need further backports > for older RTEMS versions? > > I don't think this is the way to go. Firstly, this is certainly not a > SPARC-specific > problem. > Secondly, RTEMS is multi-threaded, are you sure you can simply disable > this feature?
Well, the patch only disabled the feature in the configuration of libbacktrace. If I understand autotools correctly, this shouldn't affect other parts of gcc, i.e. if the builtins are used there they should still show up as undefined references. > RTEMS supports C11 atomic operations which includes libatomic > support. However, we lack the > __sync_* builtin support on targets without atomic operations in hardware. > This > is the problem we should fix. We should provide these functions either in > libgcc > or in libatomic. > I was afraid you would say that ;-). However, I am not sure I would know where/how to start. > One open question is why is there a libbacktrace dependency in libgfortran? > Does this add any value to embedded targets? > I don't think so. That's why I assumed it would be safe to change the configuration of libbacktrace in order to get the fortran program to compile. > -- > Sebastian Huber, embedded brains GmbH > > Address : Dornierstr. 4, D-82178 Puchheim, Germany > Phone : +49 89 189 47 41-16 > Fax : +49 89 189 47 41-09 > E-Mail : sebastian.hu...@embedded-brains.de > PGP : Public key available on request. > > Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel