On Fri, Jan 27, 2017 at 09:09:14AM +0000, Richard W.M. Jones wrote: > I pushed gperf 3.1 to Rawhide. > > This changes the type of one of the parameters of the generated > perfect hash function: > > -char *in_word_set (register const char *str, register unsigned int len); > +char *in_word_set (register const char *str, register size_t len); > > If you have the function prototyped in another file, then you have to > be careful that the prototype exactly matches the new type. Otherwise > on 64 bit architectures you'll end up passing an incorrectly sized > 'len' argument (unsigned int == 32 bits vs size_t == 64 bits) which > will subtly break in certain circumstances (but on little endian it'll > still work most of the time, making this bug rather insidious). > > Using the functions (third) section of the gperf file can avoid > needing to prototype the function elsewhere, since you can drop a > wrapper of your own choosing into the functions section. There was a bit of fallout from this change. Mainly it broke systemd, although there was already a fix upstream. If you're wondering how to fix this, here are two approaches you can take. Firstly the systemd fix which involves sensing the function signature at ./configure time and adjusting the prototype: https://github.com/systemd/systemd/commit/c9f7b4d356a453a01aa77a6bb74ca7ef49732c08 Alternately, this is the approach I took for libguestfs. Move all calls to the hash function into the functions (third) section of the gperf source file, so no explicit prototype is needed: https://github.com/libguestfs/libguestfs/commit/004de6cf45cfe66ca166cbdcb1c3125a2a81eb31 https://github.com/libguestfs/libguestfs/commit/48d4117789e92489b9a3c6f3456b0770b3fdb290 Hope that helps others who have gperf problems. You can also follow up here if you don't know how to fix it for a particular package and I'll see if I can help. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx
