We could also AC_TRY_LINK a program that uses ffsfoo (the one that actually breaks here). If it fails, we AC_TRY_LINK a program that uses ffsfoo with the __ffssi2() definition. If it fails, we define NEED_FFS_FIX And we just add the fix under #ifdef NEED_FFS_FIX in private/misc.h. Would that work? thanks Brice
Le 02/02/2012 02:28, Paul H. Hargrove a écrit : > > On 2/1/2012 11:46 AM, Paul H. Hargrove wrote: > [snip] >> So, in short: when building w/ this compiler, hwloc needs to behave >> as if the system lacks ffs(). >> >> Making that happen is non-trivial because there are no preprocessor >> symbols defined by gccfss that would allow compile-time #if checks to >> distinguish gccfss from "vanilla" gcc. The only difference is in the >> string value of __VERSION__, which one could check at configure time. > > Attached is a patch, relative to the svn trunk, which fixes this > problem in my testing. > As I outlined above, the approach is two-fold: > 1) Add configure-time logic to ID the buggy compiler > 2) Restructure include/private/misc.h to include a > HWLOC_HAVE_BROKEN_FFS case. > > Two things I'd like to note about the approach: > > + The configure-time logic is NOT trying to determine the version > number, as I don't have a way (yet?) to pinpoint which version(s) work > correctly, and the Oracle Forums thread on the subject doesn't say. > So, it is conservatively assuming all "gccfss" versions are broken. > > + The misc.h changes are intentionally "generic" so one could add > other configure time checks to define HWLOC_HAVE_BROKEN_FFS based on > problems we've not yet discovered. > > -Paul > > > _______________________________________________ > hwloc-devel mailing list > hwloc-de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/hwloc-devel
