Re: [Libguestfs] [PATCH 3/3] daemon/yara: fix undefined behavior due to Yara 4.0 API changes

On Tue, Oct 12, 2021 at 12:36:27AM +0200, Laszlo Ersek wrote: > The prototype of yara_rules_callback() is: > > > static int > > yara_rules_callback (int code, void *message, void *data) > > however, in Yara commit 2b121b166d25 ("Track string matches using > YR_SCAN_CONTEXT.", 2020-02-27), which was included in the upstream v4.0.0 > release, the rules callback prototype was changed as follows: > > > diff --git a/libyara/include/yara/types.h b/libyara/include/yara/types.h > > index cad095cd70c2..f415033c4aa6 100644 > > --- a/libyara/include/yara/types.h > > +++ b/libyara/include/yara/types.h > > @@ -661,6 +644,7 @@ struct YR_MEMORY_BLOCK_ITERATOR > > > > > > typedef int (*YR_CALLBACK_FUNC)( > > + YR_SCAN_CONTEXT* context, > > int message, > > void* message_data, > > void* user_data); Do we intend to compile against both older and newer versions of Yara, in which case we'd need a configure-time probe of which variant we must compile against? I could not quickly find documentation of a minimum version of Yara that we are willing to support, at least not in README or HACKING.