On Thu, Jan 03, 2019 at 06:57:25PM +0100, Luca Boccassi wrote: > Whenever possible (if the library ships a pkg-config file) use meson's > dependency() function to look for it, as it will automatically add it > to the Requires.private list if needed, to allow for static builds to > succeed for reverse dependencies of DPDK. Otherwise the recursive > dependencies are not parsed, and users doing static builds have to > resolve them manually by themselves. > When using this API avoid additional checks that are superfluos and > take extra time, and avoid adding the linker flag manually which causes > it to be duplicated. > > An internal checker has been added to Meson 0.42 to detect libpcap, > which ships a custom tool rather than a pkg-config file, so bump the > minimum Meson version from 0.41 to 0.42.
If we are going to bump the version, I think we should bump it further to e.g. 0.46 or 0.47 unless there is anyone who still wants an earlier version. That should get rid of a number of the meson version warnings we see on each run. > > For libbsd, which is checked in a top level file and used to be added > to the global linker flags array, add it to the ext_deps array of > all top level meson files (app, test, lib, examples, drivers). The > most correct change would be to let each individual library/driver/app > depend on it individually if they use symbols from it, but it would > diverge from the legacy Makefile's behaviour and make life a bit more > difficult for contributors. It shouldn't be necessary to add libbsd as a dependency for everything. I think just adding it as a dependency of EAL should work fine. However, in conjunction with meson version checks, I believe this was done this way originally because of a meson bug which caused recursive dependencies for things like this to get duplicated many times in the build.ninja file. https://github.com/mesonbuild/meson/issues/2150 If we take the approach of adding bsd explicitly using dependency object our minimum version needs to have the fix for this bug included. > > Fixes: a25a650be5f0 ("build: add infrastructure for meson and ninja builds") > Cc: sta...@dpdk.org > > Signed-off-by: Luca Boccassi <bl...@debian.org> > --- > > Bruce, dependency() by default tries pkg-config first, then cmake, then > the internal project-specific finders (like pcap). If you think it's > worth it I can add fallbacks in case a system, for whatever reason, > does not install a pc file despite the upstream project providing one. > It would add more clutter and more verbosity, but it would not cause > other issues. I'd prefer to keep it without that for now. If the lack of .pc files causes issues we can revisit. /Bruce >
