CI: Disable ASan fast unwinding for suppressions

Unfortunately just adding suppressions isn't enough; the build of Expat
we have in our CI system does not have frame pointers, so ASan's fast
unwinder can't see through it. This means that the suppressions we've
added won't be taken into account.

For now, disable the fast unwinder for the Xwayland test only. Disabling
it globally is not practical as it massively increases the per-test
runtime, so here (to avoid polluting the build system), we use a
per-test wrapper to selectively choose the unwinder.

Signed-off-by: Daniel Stone <daniels@collabora.com>

.gitlab-ci.yml

@@ -202,7 +202,7 @@ aarch64-debian-container_prep:
     - $BUILDDIR/weston-virtme
     - $PREFIX
     reports:
-      junit: $BUILDDIR/meson-logs/testlog.junit.xml
+      junit: $BUILDDIR/meson-logs/testlog-per-test-asan.sh.junit.xml
 
 # Same as above, but without running any tests.
 .build-no-test:

.gitlab-ci/virtme-scripts/per-test-asan.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+# When running Debian's Xwayland and fontconfig, we hit memory leaks which
+# aren't visible on other setups. We do have suppressions for these tests, but
+# regrettably ASan can't see through omitted frame pointers in Expat, so for
+# Xwayland specifically, we disable fast-unwind.
+#
+# Doing it globally makes the other tests far, far, too slow to run.
+case "$1" in
+  *xwayland*)
+    export ASAN_OPTIONS="detect_leaks=0,fast_unwind_on_malloc=0"
+    ;;
+  *)
+    export ASAN_OPTIONS="detect_leaks=0"
+    ;;
+esac
+
+export ASAN_OPTIONS
+
+exec "$@"

.gitlab-ci/virtme-scripts/run-weston-tests.sh

@@ -26,13 +26,13 @@ export HOME=/root
 export PATH=$HOME/.local/bin:$PATH
 export PATH=/usr/local/bin:$PATH
 
-export ASAN_OPTIONS=detect_leaks=0,atexit=1
 export SEATD_LOGLEVEL=debug
 
 # run the tests and save the exit status
 # we give ourselves a very generous timeout multiplier due to ASan overhead
 echo 0x1f > /sys/module/drm/parameters/debug
-seatd-launch -- meson test --no-rebuild --timeout-multiplier 4
+seatd-launch -- meson test --no-rebuild --timeout-multiplier 4 \
+	--wrapper $(pwd)/../.gitlab-ci/virtme-scripts/per-test-asan.sh
 # note that we need to store the return value from the tests in order to
 # determine if the test suite ran successfully or not.
 TEST_RES=$?