Yeah, this isn't documented very well, sorry about that. get_building_env in tools/shared.py is where we set env vars like PKG_CONFIG_LIBDIR etc. We override them because we can't use the system installed versions, we need emcc-compiled bitcode. So you can in principle alter the pkg-config pointed at there for your ported projects (looks like it points to system/lib/pkgconfig). But I don't know enough about pkg-config to tell how practical that is to do.
The bigger question is what is the best way to do cross-compiling. Open to suggestions here. In general we recommend using ports, which usually amounts to just adding -s USE_ZLIB=1 to CFLAGS, for example. Otherwise, people need to set up CFLAGS to find headers in the right places, etc., somewhat manually, and also manually link in all the bitcode at the end. When you compile multiple new libraries yourself as you describe, perhaps there's a way we could make it easier? What do you mean by "install into a prefix"? On Sun, Dec 18, 2016 at 8:02 AM, Allan Wirth <alla...@gmail.com> wrote: > Hi there! > > Recently, I successfully ported some old code of mine using emscripten. > The code relied on libgd with libjpeg and libpng (which requires zlib) > support, so I had to compile and link all of that in. I didn't understand > how to use emscripten ports with libraries, so I decided to do it all from > scratch. > > This ended up being kind of a mess, because emconfigure seems to override > some important variables, like PKG_CONFIG_LIBDIR. I had expected to just > build each lib and install the artifacts into a prefix for linking later, > but this didn't work directly. You can find my compile script (in the form > of a Dockerfile) at https://github.com/allanlw/fractal-web/blob/master/ > Dockerfile and you will see that it is quite messy, and calls bash inside > of emconfigure to re-set important environment variables. > > I couldn't find much documentation about emconfigure. Is there a cleaner > way to do this? > > Thanks, > Allan > > -- > You received this message because you are subscribed to the Google Groups > "emscripten-discuss" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to emscripten-discuss+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "emscripten-discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to emscripten-discuss+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
