We cannot use `gvisibility_h` for different visibility header files; you
never know when you're going to refer to the variable again, and
projects might end up needing to retrieve the variable contents—like,
for instance, gobject-introspection using glib as a subproject.
Given that it can be computed using an error-prone strings comparisons it
is better to provide a variable everywhere, so that we don't have the
risk of comparing values that are always false.
This ensures that we do really export the symbols for Visual
Studio-style builds, by using _GLIB_EXTERN to decorate the generated
prototypes and including config.h so that we are sure the symbols are
actually exported.
The executable depends only on the generated header file at compile
time, and on the library at link time. So meson can decide to compile
gdbus-peer.c before compiling the library and thus won't have generated
the header yet, causing the build error.
So declare_dependency() should only have the header file in its sources,
to force generating files before compiling gdbus-peer.c without
including objectmanager-gen.c into gdbus-peer's sources.
We use libgdbus_example_objectmanager_dep as dependency for various
tests, but this implies only a link dependency while it doesn't ensure
that the sources are generated.
Make this explicit
When using glib as a meson subproject on Windows the build currently fails
due to too long paths during the build process. See
https://github.com/mesonbuild/meson/issues/4226 for the upstream bug.
To work around the issue shorten the filenames of the generated gdbus files.
Properly define GLIB/GOBJECT_STATIC_COMPILATION when static build is enabled.
Use library() instead of shared_library() to allow selecting static builds.
https://bugzilla.gnome.org/show_bug.cgi?id=784995
