These are equivalent to the non-null throw, except that the returned
value is a NULL pointer. They can be used in functions where one wants
to return a pointer. E.g.:
GKeyFile *foo(GError **error) {
return glnx_null_throw (error, "foobar");
}
The function call redirections are wrapped around a compound statement
expression[1] so that they represent a single top-level expression. This
allows us to avoid -Wunused-value warnings vs using a comma operator if
the return value isn't used.
I made the 'args...' absorb the fmt argument as well so that callers can
still use it without always having to specify at least one additional
variadic argument. I had to check to be sure that the expansion is all
done by the preprocessor, so we don't need to worry about stack
intricacies.
[1] https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html
libglnx is the successor to libgsystem: https://git.gnome.org/browse/libgsystem
It is for modules which depend on both GLib and Linux, intended to be used as a git submodule.
Features:
- File APIs which use
openat()like APIs, but also take aGCancellableto support dynamic cancellation - APIs also have a
GErrorparameter - High level "shutil", somewhat inspired by Python's
- A "console" API for tty output
- A backport of the GLib cleanup macros for projects which can't yet take a dependency on 2.40.
Why?
There are multiple projects which have a hard dependency on Linux and GLib, such as NetworkManager, ostree, xdg-app, etc. It makes sense for them to be able to share Linux-specific APIs.
This module also contains some code taken from systemd, which has very high quality LGPLv2+ shared library code, but most of the internal shared library is private, and not namespaced.
One could also compare this project to gnulib; the salient differences there are that at least some of this module is eventually destined for inclusion in GLib.
Porting from libgsystem
For all of the filesystem access code, libglnx exposes only
fd-relative API, not GFile*. It does use GCancellable where
applicable.
For local allocation macros, you should start using the g_auto
macros from GLib. A backport is included in libglnx. There are a few
APIs not defined in GLib yet, such as glnx_fd_close.
gs_transfer_out_value is replaced by g_steal_pointer.
Contributing
Currently there is not a Bugzilla product - one may be created in the future. You can submit PRs against the Github mirror:
https://github.com/GNOME/libglnx/pulls
Or alternatively, email one of the maintainers directly.