It doesn't make sense for a proxy resolver to return NULL without an
error on the first call. Whereas a DNS resolver would do this to
indicate that a query completed successfully but found no results, a
proxy resolver should return "direct://" instead. Therefore, if we are
going to return NULL, we ought to have an error as well. Let's make sure
this actually happens by adding some fallback errors just in case
GProxyResolver feeds us weird results.
Additionally, we should not return any errors except
G_IO_ERROR_CANCELLED after the very first iteration. This is an API
contract of GSocketAddressEnumerator. Let's add some checks to ensure
this.
Note that we have inadequate test coverage for GProxyAddressEnumerator.
It's tested here only via GSocketClient. We could do a bit better by
testing it directly as well. For example, I've added tests to see what
happens when GProxyResolver returns both a valid and an invalid URI, but
it's not so interesting here because GSocketClient always uses the valid
result and ignores the error from GProxyAddressEnumerator.
Fixes#2597
This has no practical impact, since it's only a test, and none of the
test code would have hit this bug, but the GTestProxyResolver's check to
see if the URI scheme is simple:// currently only compares the first
four bytes of the string, so it's actually only checking for the "simp"
and would match anything else after that, e.g. "simpleton://". This is
surely not intended.
This was causing intermittent failures on macOS, depending on whether
the tmpdir ended with a `/` or `/some-dir`. `g_strrstr()` is not the
right function to use to extract a basename from a path, for this
reason.
When it failed, the macOS test was failing with:
```
ok 16 /gsubprocess/env
Bail out! GLib-GIO:ERROR:../gio/tests/gsubprocess.c:1507:test_cwd: assertion failed (basename == tmp_lineend_basename): ("/T\n" == "/\n")
```
The test now passes reliably, which means that it can be removed from
the list of expected failures on macOS.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1392
On macOS the comparison was failing as one of the paths had a trailing
slash while the other didn’t.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Despite the name, we still used blocking calls to get the default app
for URI, now that we have an async implementation of the API to get the
default implementation for URI scheme, we can remove the blocking calls.
We did not check whether this function worked before, so add a simple
test case for it, providing some test functions to make it possible to
reply the same behavior
While it's possible to create a directory synchronously via
g_dir_make_tmp(), there's no such API that performs it asynchronously.
So implement it using GFile, using a thread to perform such task.
It seems this script has potentially never worked properly under Python
3. It’s supposed to list all the `_get_type()` functions it can find in
the GIO headers, but since the regex string passed to `re.search()` was
not a Python regex, nothing was matching.
Fix that, and do another few small cleanups to the script.
This makes the `defaultvalue` test not skip all the types.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
When running under a strict TAP parser this was previously producing
problematic non-conforming output.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
The interface was ready for this API but it was not provided.
So implement this, using a thread that calls the sync API for now.
Add tests.
Helps with: GNOME/glib#157
Dynamically, these will only ever be used after they’ve been initialised
due to correct checking of `use_udp` throughout the test. However,
that’s a global variable and the static analyser is assuming it might
change value. So help it out by NULL-initialising the variables so they
can never be used uninitialised.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
This is a fallback timeout to abort the test if the expected number of
messages aren’t seen in time. However, when running the test under
valgrind it will take longer and sometimes spuriously trigger the
timeout.
There’s no point in having an abort timeout inside the test: the test
runner (Meson) already provides one for us, which we can adjust with a
multiplier when running under valgrind.
So removes the timeout from within the test. This should fix the
gnotification test under valgrind.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
These have all been added manually, as I’ve finished all the files which
I can automatically detect.
All the license headers in this commit are for LGPL-2.1-or-later, and
all have been double-checked against the license paragraph in the file
header.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1415
This may have been causing an intermittent failure of the pollable test
on BSD, where updating the readable status of a socket takes a bit
longer than on Linux.
```
GLib-GIO-DEBUG: 16:06:41.235: GSocketClient: Starting application layer connection
GLib-GIO-DEBUG: 16:06:41.235: GSocketClient: Connection successful!
Bail out! GLib-GIO:ERROR:../gio/tests/pollable.c:73:check_source_readability_callback: assertion failed (readable == expected): (0 == 1)
```
I have not debugged the test on BSD, though, so this is only a guess.
See https://gitlab.gnome.org/GNOME/glib/-/jobs/2022087
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
This should make each unit test a bit more self-contained and easier to
verify that they’re independent.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
This test is opportunistic in that it’s not possible to detect whether
the race condition has been hit (other than by hitting a deadlock).
So the only approach we can take for testing is to loop over the code
which has previously been known to cause a deadlock a number of times.
The number of repetitions is chosen from running the test with the
deadlock fix reverted.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1941
Add SPDX license (but not copyright) headers to all files which follow a
certain pattern in their existing non-machine-readable header comment.
This commit was entirely generated using the command:
```
git ls-files gio/tests/*.c | xargs perl -0777 -pi -e 's/\n \*\n \* This library is free software; you can redistribute it and\/or\n \* modify it under the terms of the GNU Lesser General Public/\n \*\n \* SPDX-License-Identifier: LGPL-2.1-or-later\n \*\n \* This library is free software; you can redistribute it and\/or\n \* modify it under the terms of the GNU Lesser General Public/igs'
```
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1415
The raw value is escaped according to D-Bus rules. This is probablematic
for Windows backslashed paths. We can use URI unescaping, it seems
that's what gdbusaddress.c is doing too.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
The "/unix-fd/scm" test is quite Unix-specific, the next patch is going
to add a portable test.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Use a prefix matching the binary, rename the test "scm", as it involves
SocketControlMessage.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
It is not only shorter than `not meson.is_cross_build() or
meson.has_exe_wrapper()` but also handle the case of cross compiling to
a compatible arch such as building for i386 on an amd64.
This fixes a scan-build warning:
```
../../../../source/glib/gio/tests/gdbus-tests.c:146:3: warning: Value stored to 'watch_id' is never read [deadcode.DeadStores]
watch_id = 0;
^
```
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1767
When I enabled unix socketpair test on win32, I left the existing
g_close(fds[1]), but _g_win32_socketpair() returns native sockets
descriptors that must be closed with closesocket() on win32.
Let GSocket handle the socket pair cleanup.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
When checking that the connection has the expected number of refs, the
test would block on a `GMainContext` iteration for up to 3s before
waking up and failing (if the refcount was still not as expected).
This check was written in the expectation that changing the refcount of
the connection would only happen due to dispatching a source on
`GMainContext` — hence the `GMainContext` would wake up as the refcount
changed.
That’s probably not actually true though. It might be the case that the
connection’s refcount is changed on from the GDBus worker thread, which
would not cause any wakeups on the main thread’s `GMainContext`.
In this case, the `GMainContext` iteration in
`assert_connection_has_one_ref()` would block for the full 3s, and then
wake up and notice the refcount is correct (then the test would
proceed).
That’s fine, apart from the fact that `test_threaded_singleton()` does
this 1000 times. If the slow case is hit on a significant number of
those test runs, the test will take around 3000s to complete, which is
significantly more than meson’s test timeout of 360s. So the test fails
with something like:
```
220/266 glib:gio+slow / gdbus-threading TIMEOUT 360.07 s
--- command ---
G_TEST_SRCDIR='/builds/GNOME/glib/gio/tests' GIO_MODULE_DIR='' G_TEST_BUILDDIR='/builds/GNOME/glib/_build/gio/tests' /builds/GNOME/glib/_build/gio/tests/gdbus-threading
--- stdout ---
\# random seed: R02S83fe8de22db4d4f376e6d179e2bdd601
1..3
\# Start of gdbus tests
ok 1 /gdbus/delivery-in-thread
ok 2 /gdbus/method-calls-in-thread
\# GLib-GIO-DEBUG: refcount of 0x5602de913660 is not right (3 rather than 1) in test_threaded_singleton(), sleeping
\# GLib-GIO-DEBUG: refcount of 0x5602de913660 is not right (3 rather than 1) in test_threaded_singleton(), sleeping
\# GLib-GIO-DEBUG: refcount of 0x5602de913c60 is not right (3 rather than 1) in test_threaded_singleton(), sleeping
\# GLib-GIO-DEBUG: refcount of 0x5602de913c60 is not right (3 rather than 1) in test_threaded_singleton(), sleeping
\# GLib-GIO-DEBUG: refcount of 0x5602de913260 is not right (3 rather than 1) in test_threaded_singleton(), sleeping
\# GLib-GIO-DEBUG: refcount of 0x5602de913260 is not right (3 rather than 1) in test_threaded_singleton(), sleeping
```
From this log, it can be seen that the sleep is happening on a different
`GMainContext` every other time, so the test *is* making progress.
Assuming this is a correct diagnosis (it’s a lot of guessing), this
commit tries to fix the test by adding a wakeup timeout to the
`GMainContext` in `assert_connection_has_one_ref()`, which will wake it
up every 50ms to re-check the exit condition.
This polling approach has been taken because it doesn’t seem feasible to
make sure that every `g_object_ref()`/`g_object_unref()` call on a
`GDBusConnection` causes the main context to wake up.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
This might fix a recent test failure:
https://gitlab.gnome.org/GNOME/glib/-/jobs/1929015. Unfortunately
there’s not much debug information in the logs to go on, and I can’t
reproduce it locally. All I have is:
```
192/272 glib:gio / gdbus-peer-object-manager FAIL 0.43 s (killed by signal 11 SIGSEGV)
--- command ---
GIO_MODULE_DIR='' G_TEST_BUILDDIR='/builds/GNOME/glib/_build/gio/tests' G_TEST_SRCDIR='/builds/GNOME/glib/gio/tests' /builds/GNOME/glib/_build/gio/tests/gdbus-peer-object-manager
--- stdout ---
\# random seed: R02Seee9b7325ecd7c19249a3412397aed9b
1..2
\# Start of gdbus tests
\# Start of peer-object-manager tests
```
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
While the assertion always turned out to be true on Linux, it frequently
caused spurious test failures on FreeBSD.
After some remote debugging, I *think* the cause is as written up in the
comment in the code in this commit. However, I cannot be certain, as the
more debugging messages I added, the harder the failure was to
reproduce; and I don’t have access to a FreeBSD machine.
This fixes failures like:
```
Bail out! GLib-GIO:ERROR:../gio/tests/converter-stream.c:1043:test_converter_pollable: assertion failed (error == NULL): Resource temporarily unavailable (g-io-error-quark, 27)
```
It’s succeeded 1000 times in a row on the FreeBSD CI now; previously
it was failing one time in three:
https://gitlab.gnome.org/GNOME/glib/-/jobs/1936395.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
There’s (deliberately) a bit of race in implementing/handling
`CloseBeforeReturning()` in `gdbus-method-invocation.c`. If the server
closes the D-Bus connection early, the client may exit with `SIGTERM` if
`GDBusConnection:exit-on-close` is set. We don’t want that, as the test
is trying to check that the default handling of a D-Bus method return
after a connection has closed works.
See https://gnome.pages.gitlab.gnome.org/-/glib/-/jobs/1935191/artifacts/_build/meson-logs/testlog.txt
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
G_GNUC_UNUSED does perfectly its job with gcc compiler but the warning
still remains with msvc compiler.
Once the unused variable removed, the finalize vfunc can be removed as
it's doing the same job as the parent function.
Success and failure tests. This massively increases test coverage for
parsing DNS records, although it doesn’t get it to 100%.
It should now be useful enough to do more fuzzing on, without
immediately getting trivial failures from the fuzzer.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Otherwise the code isn’t forwards-compatible, and may be DOSed by
servers returning unknown records, if `G_DEBUG=fatal-warnings` is
enabled for some reason.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Split out from https://gitlab.gnome.org/GNOME/glib/-/merge_requests/2134
by Philip Withnall so it can be used in advance of HTTPS DNS record
support landing.
Reworked to no longer use test fixtures, as it’s simple enough to build
the response header in each test.
The tests are built on Unix only, as they test the parsing code in
`g_resolver_records_from_res_query()`, which is Unix-specific. The
Windows DNS APIs provide much more structured results which don’t need
parsing.
The SONAME of libutil varies between architectures, so the logic to find
the SONAME of libutil was only correct for native builds (Linux on
Linux), not for cross-builds. The regular expression was also not
sufficiently broad to match the SONAME used on the alpha architecture,
which is apparently libutil.so.1.1.
Instead of screen-scraping the output of ldconfig and using that to
dlopen the library that contains openpty, it seems more reliable to
emit a link-time reference to openpty and let the linker do its job.
It's also less code.
Bug-Debian: https://bugs.debian.org/1007946
Signed-off-by: Simon McVittie <smcv@collabora.com>
These should cover everything to do with returning a value or error from
a `GDBusMethodInvocation` object.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
The public `g_strv_contains()` API didn’t exist at the time this code
was originally written. Now, happily, it does.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
When the test has finished writing all the expanded content into the
socket, explicitly close the output stream, which should make the input
stream readable and non-blocking.
The code intended to do this before, but only as a side-effect of
dropping its last reference to `right`. If another reference was being
held to `right` somewhere else, it wouldn’t end up being closed, which
would lead to failures like
https://gitlab.gnome.org/GNOME/glib/-/jobs/1890000:
```
(/var/tmp/gitlab_runner/builds/Ff4WDDRj/0/GNOME/glib/_build/gio/tests/converter-stream:56570): GLib-GIO-DEBUG: 12:56:23.280: GSocketClient: Connection successful!
Bail out! GLib-GIO:ERROR:../gio/tests/converter-stream.c:1042:test_converter_pollable: assertion failed (error == NULL): Resource temporarily unavailable (g-io-error-quark, 27)
stderr:
```
This is a bit of a guess (I’m not sure it’ll fix the intermittent test
error, as I haven’t been able to reproduce that locally), but it’s worth
a try.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
When multiple tests were run in parallel, this would race on its access
to `~/.dbus-keyrings` to authenticate with the D-Bus server, since the
keyring directory was not appropriately sandboxed to the unit test.
Use `G_TEST_OPTION_ISOLATE_DIRS` to automatically isolate each unit
test’s directory usage.
This should hopefully fix the failure seen in
https://gitlab.gnome.org/GNOME/glib/-/jobs/1849524, where the following
was in the log for a test executed in parallel:
```
GDBus-DBUS_COOKIE_SHA1: Deleted stale lock file '/home/user/.dbus-keyrings/org_gtk_gdbus_general.lock'
```
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
When multiple tests were run in parallel, this would race on its access
to `~/.dbus-keyrings` to authenticate with the D-Bus server, since the
keyring directory was not appropriately sandboxed to the unit test.
Use `G_TEST_OPTION_ISOLATE_DIRS` to automatically isolate each unit
test’s directory usage.
This should hopefully fix the failure seen in
https://gitlab.gnome.org/pwithnall/glib/-/jobs/1879558.
```
228/266 glib:gio / gdbus-non-socket FAIL 8.64 s (killed by signal 6 SIGABRT)
…
--- stderr ---
GDBus-DBUS_COOKIE_SHA1: Deleted stale lock file '/home/user/.dbus-keyrings/org_gtk_gdbus_general.lock'
**
GLib-GIO:ERROR:../gio/tests/gdbus-non-socket.c:253:test_non_socket: assertion failed (error == NULL): Exhausted all available authentication mechanisms (tried: EXTERNAL, DBUS_COOKIE_SHA1) (available: EXTERNAL, DBUS_COOKIE_SHA1) (g-io-error-quark, 0)
```
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
If the whole set of tests takes more than 5 seconds, the failure timeout
from the first test could still trigger, causing an incorrect failure.
Ensure the timeout is removed at the end of each test.i
This will hopefully fix the CI failure seen here:
https://gitlab.gnome.org/pwithnall/glib/-/jobs/1879558.
```
204/266 glib:gio / gdbus-auth FAIL 9.21 s (killed by signal 5 SIGTRAP)
…
ok 1 /gdbus/auth/client/EXTERNAL
Bail out! GLib-GIO-FATAL-ERROR: Timeout waiting for client
```
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Now that the leaks are fixed, this test can be run under the sanitizer
again.
This is a partial revert of commit
f378352051.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2312
When destroying `GDBusProxy`s in a custom `GMainContext`, the context
must be iterated enough after finalisation of the proxies that any
pending D-Bus traffic, and the signal subscription data, can be freed.
See the documentation for `g_dbus_connection_signal_unsubscribe()`.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Fixes: #2312
The `ay` property has type `string` (see the generated code) since it’s
not been annotated to force accepting a `GVariant`.
This means the GObject property machinery expects a string, and calls
`g_strdup()` on the passed-in pointer, rather than sinking the
`GVariant`.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2312
It periodically hangs due to the `GDBusConnection` having more than 1
ref (and never losing them), so there’s potentially a leaking ref
somewhere:
```
(/builds/alexander.klauer/glib/_build/gio/tests/gdbus-threading:17767): GLib-GIO-DEBUG: 13:18:12.268: refcount of 0x55fe85b1a260 is not right, sleeping
\# GLib-GIO-DEBUG: refcount of 0x55fe85b1a260 is not right, sleeping
```
Add some more debug output to try and track the problem down.
See: https://gitlab.gnome.org/alexander.klauer/glib/-/jobs/1865968
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
It’s periodically failing on FreeBSD and I can’t reproduce the failure
locally nor work out what it is from the logs:
```
Bail out! GLib-GIO:ERROR:../gio/tests/converter-stream.c:1041:test_converter_pollable: assertion failed (res != -1): (-1 != -1)
stderr:
**
GLib-GIO:ERROR:../gio/tests/converter-stream.c:1041:test_converter_pollable: assertion failed (res != -1): (-1 != -1)
```
Add some more debug output to get the value of `error`, in the hope that
will provide some insight.
See: https://gitlab.gnome.org/GNOME/glib/-/jobs/1866486
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Commit 13c4b9579b seems to have fixed
`network-address` so that it’s reliable everywhere, including on macOS.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1392
This reverts commit 1ed67a9c44.
It turns out that including options, with their default values, in the
`handle-local-options` signal, which weren’t set on the command line,
breaks some applications.
In particular, it breaks Inkscape, which is the application this commit
was originally meant to fix (a different problem).
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Fixes: #2611
Breaks: #2329
See: !1953
`mock-resolver.c` is a mock implementation of `GResolver` used in the
`network-address` tests. It returns resolver results, and implements
timeouts, as directed by the test calling it.
In particular, it allows the IPv4 and IPv6 resolver results to be
returned using independent delays. This allows code paths which deal
with IPv4 and IPv6 results being returned at different times to be
tested, as the ‘Happy Eyeballs’ spec mandates various hard-coded
timeouts for returning the best results it can in a reasonable
timeframe.
Previously, `mock-resolver.c` implemented the timeouts by handling
`lookup_by_name()` in a `GTask` worker thread, and calling `g_usleep()`
for the timeout. This seemed to cause occasional CI failures, such as
https://gitlab.gnome.org/GNOME/glib/-/jobs/1843454, where a resolver
error would be returned rather than the expected results:
```
ok 52 /network-address/happy-eyeballs/ipv4-error-ipv6-first
\# GLib-GIO-DEBUG: IPv4 DNS error: IPv4 Broken
(/var/tmp/gitlab_runner/builds/Ff4WDDRj/0/GNOME/glib/_build/gio/tests/network-address:18428): GLib-GIO-DEBUG: 09:03:08.587: IPv4 DNS error: IPv4 Broken
Bail out! GLib-GIO:ERROR:../gio/tests/network-address.c:586:got_addr: assertion failed (error == NULL): IPv4 Broken (g-io-error-quark, 24)
stderr:
**
GLib-GIO:ERROR:../gio/tests/network-address.c:586:got_addr: assertion failed (error == NULL): IPv4 Broken (g-io-error-quark, 24)
```
While I’ve been unable to reproduce these failures locally, I suspect
they might be down to thread spawning occasionally taking long enough on
a CI runner to change the ordering of the timeouts, such that the ‘Happy
Eyeballs’ algorithm returns a different set of results from what the
test expects.
So, this commit rewrites part of `mock-resolver.c` to implement timeouts
in the main thread, rather than in a worker thread. That should
eliminate the delays in spawning threads, and should mean that the
timeout sources in `mock-resolver.c` are attached to the same
`GMainContext` as those from the ‘Happy Eyeballs’ algorithm which are
monitoring them, so a total order over the timeouts can be guaranteed.
Of course, I might be completely wrong since this is just a guess and I
can’t properly test it since I can’t reproduce the failure. Worth a try.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
The test results weren’t being freed.
This makes the `network-address` test clean under memcheck for me.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Test failures were previously ignored on macOS because there are 12
tests which consistently fail (and have not yet been fixed, because
there are no regularly active macOS maintainers for GLib; you could help
here!).
However, this means that new test failures can’t be spotted.
So, explicitly mark those 12 tests as `should_fail` on macOS, and then
make other test failures cause failure of the CI run.
We can track the process of fixing those 12 tests on #1392 and #1251.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1392
As they use `g_test_dbus_*()`, they depend on dbus-daemon, so move them
to the part of the Meson file which lists those tests.
This disables them running on platforms which don’t have `dbus-daemon`
available. Arguably, this should be done by returning an error from
`g_test_dbus_up()` and then calling `g_test_skip()`, so the test is
correctly recorded as having been skipped. But that’s a fix for another
time.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Having compared the debug output, it doesn’t show anything unusual
happening that can’t already be seen from other output, for this test.
This is a partial revert of 8fd71dccc5. The debugging output it added to
other tests may still be useful.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1929
As with the previous commit, this isn’t needed for GLib’s tests to work
correctly, but is probably needed in other projects which might be
tempted to copy and paste the Meson tooling from GLib.
Inspired by https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/4330
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
This isn’t needed to make the tests any better (it doesn’t really affect
them), but is probably needed for anyone who copies this Meson code in
order to add `glib-compile-resources` support to their project. It’s
pretty unlikely that someone would want to compile *and export* a
resource from a shared library.
Inspired by https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/4334
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>