From c6552ad381003a23cde7c3228e7071f30465df35 Mon Sep 17 00:00:00 2001
From: Frantisek Sumsal <frantisek@sumsal.cz>
Date: Wed, 6 Apr 2022 19:41:01 +0200
Subject: [PATCH 1/2] macro: call __gcov_dump() before _exit() w/ coverage
 enabled

_exit() skips at-exit hooks, causing lost coverage from processes
utilizing it.

Hopefully resolves systemd/systemd-centos-ci#482
---
 meson.build       |  3 +++
 src/basic/macro.h | 13 +++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/meson.build b/meson.build
index 0455d89b78..26f98b856c 100644
--- a/meson.build
+++ b/meson.build
@@ -47,6 +47,9 @@ fuzzer_build = want_ossfuzz or want_libfuzzer
 # More items are added later after they have been detected.
 summary({'build mode' : get_option('mode')})
 
+# GCOV doesn't define any macro when compiled with, so let's define it ourselves
+conf.set10('BUILT_WITH_COVERAGE', get_option('b_coverage'))
+
 #####################################################################
 
 # Try to install the git pre-commit hook
diff --git a/src/basic/macro.h b/src/basic/macro.h
index 68d8b062e8..685de73449 100644
--- a/src/basic/macro.h
+++ b/src/basic/macro.h
@@ -29,6 +29,19 @@
 #define _alignptr_ __attribute__((__aligned__(sizeof(void*))))
 #define _warn_unused_result_ __attribute__((__warn_unused_result__))
 
+#if defined(BUILT_WITH_COVERAGE) && BUILT_WITH_COVERAGE
+/* We need to explicitly call __gcov_dump() in places where we use _exit(), since
+ * _exit() skips at-exit hooks resulting in lost coverage */
+#  include <unistd.h>
+extern void __gcov_dump(void);
+
+_noreturn_ static inline void _coverage__exit(int status) {
+        __gcov_dump();
+        _exit(status);
+}
+#  define _exit(x) _coverage__exit(x)
+#endif
+
 #if !defined(HAS_FEATURE_MEMORY_SANITIZER)
 #  if defined(__has_feature)
 #    if __has_feature(memory_sanitizer)

From 1b2e3b8bffce0df580a9c8228cb39b823547bf11 Mon Sep 17 00:00:00 2001
From: Frantisek Sumsal <frantisek@sumsal.cz>
Date: Thu, 7 Apr 2022 12:45:13 +0200
Subject: [PATCH 2/2] test: ignore missing coverage in TEST-02

Since c6552ad we now try to collect coverage even in situations where
it's basically impossible (like in test-mount-util where the whole / is
mounted as read-only). As dealing with this is not worth the trouble,
let's ignore the missing coverage errors thrown by gcov in such cases.
---
 test/TEST-02-UNITTESTS/test.sh | 4 ++++
 test/test-functions            | 4 ++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/test/TEST-02-UNITTESTS/test.sh b/test/TEST-02-UNITTESTS/test.sh
index 571abe41c3..80cb82a50d 100755
--- a/test/TEST-02-UNITTESTS/test.sh
+++ b/test/TEST-02-UNITTESTS/test.sh
@@ -4,6 +4,10 @@ set -e
 
 TEST_DESCRIPTION="Run unit tests under containers"
 RUN_IN_UNPRIVILEGED_CONTAINER=yes
+# Some tests make collecting coverage impossible (like test-mount-util, which
+# remounts the whole / as read-only), so let's ignore the gcov errors in such
+# case
+IGNORE_MISSING_COVERAGE=yes
 
 # embed some newlines in the kernel command line to stress our test suite
 KERNEL_APPEND="
diff --git a/test/test-functions b/test/test-functions
index c734a15ca9..47eae9f0cb 100644
--- a/test/test-functions
+++ b/test/test-functions
@@ -1406,8 +1406,8 @@ check_coverage_reports() {
     # usually due to the sandbox being too restrictive (e.g. ProtectSystem=yes,
     # ProtectHome=yes) or the $BUILD_DIR being inaccessible to non-root users - see
     # `setfacl` stuff in install_compiled_systemd().
-
-    if "${JOURNALCTL:?}" -q --no-pager -D "${root:?}/var/log/journal" --grep "profiling:.+?gcda:[Cc]annot open"; then
+    if ! get_bool "${IGNORE_MISSING_COVERAGE:=}" && \
+       "${JOURNALCTL:?}" -q --no-pager -D "${root:?}/var/log/journal" --grep "profiling:.+?gcda:[Cc]annot open"; then
         derror "Detected possibly missing coverage, check the journal"
         return 1
     fi