On Wed, Dec 31, 2014 at 02:57:43PM +0100, Reimar Döffinger wrote: > On Wed, Dec 31, 2014 at 02:38:20PM +0100, Clément Bœsch wrote: > > On Wed, Dec 31, 2014 at 02:23:54PM +0100, Reimar Döffinger wrote: > > > On Wed, Dec 31, 2014 at 02:09:42PM +0100, Nicolas George wrote: > > > > Le primidi 11 nivôse, an CCXXIII, Reimar Döffinger a écrit : > > > > > I don't care much, but I still find not having to use pkg-config > > > > > somewhat more convenient in a cross-compilation environment where > > > > > you don't want to install all dependencies just to make it work with > > > > > pkg-config (or alternatively manually hack those files). > > > > > > > > Can you elaborate on that? I suspect there are ways of making this work > > > > easily with pkg-config, but you are to vague about the dependencies you > > > > want > > > > to avoid, so I can not suggest a way. > > > > > > If I just download libspeex, libfdk_aac, libsdl etc. and build them > > > with CC=i686-mingw32-gcc ./configure, then without pkg-config I can > > > just add a few paths to -I and -L and I can link against them. > > > With pkg-config things tend to get inconsistent and more complicated. > > > For example some programs (no, I haven't tried lately so I don't > > > remember examples) generate them only on install, so you have to > > > make install. But to do that you have to figure out how to specify > > > a install directory. > > > > The .pc files are obviously generally generated because the library they > > depend on (for static stuff) depends on your configure options, so > > obviously that's what you want: flags automatically added that way. > > The problem isn't them being generated. > The problem is if it is only "make install" that generates them. >
How is that really a problem? You can just ./configure --prefix=$PWD/install (or wherever you fancy) from the library source directory > > > Even if they don't, you still have to add the .pc paths in addition. > > > From my point of view it's only more convenient if all you want to > > > use are things that are pre-packaged by your distribution. > > > Btw. would you be less opposed to a patch that added less obfuscation? > > > > > It looks to me like we would just require an extra "fallback -l" option > > > (preferably also a fallback extra cflags one) to use_pkg_config to allow > > > hiding all the extra complexity in one place, inside that function. > > > > The problem is that the fallback is really broken. pkg-config has a > > mechanism to check for version, it also has a mechanism to raise different > > flags depending on the build, and it also has a system to differenciate > > the flags necessary for static or dynamic building. > > > > Look at the current multiline and unreliable (no pkg-config + x264 with > > opencl will badly break) > > That is not obvious to me, why would it badly break? > If it does, doesn't that mean require_pkg_config will break the same > way if your .pc happens to be from a non-opencl x264 by mistake, > and thus it would be better to fix anyway? > You're supposed to have your .pc file in $PREFIX/lib/pkgconfig/x264.pc along with $PREFIX/lib/x264.pc You obviously need to make pkg-config point on the appropriate directory if it's in a special place (with PKG_CONFIG_PATH). And this process is widely documented. > > And if the user doesn't have pkg-config, an explicit error is raise: "you > > must install pkg-config", which is simpler to solve than a weird linkage > > error on opencl in the config.log and an error saying "i can't find x264" > > It's not necessarily easier to solve when users end up with broken .pc files. > Which happens easily if they e.g. have a system x264.pc file and try to > use a locally compiled one (with OpenCL enabled for example). > If we don't have a reliable detection, these issues will happen even > with pkg-config. > And if we have a reliable detection, except for the complexity we need > to handle I don't see a big issue with making a least-effort attempt > without pkg-config. -- Clément B.
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