Automate exclusion of loop device tests from CI image (!105)

Avoid having to manually maintain the list of excluded File System tests
in the GitLab Docker CI image.  Scan the unit test source extracting
those tests marked with SKIP_IF_NOT_ROOT_FOR_REQUIRED_LOOPDEV_FOR_FS()
to automatically construct the setting for the GTEST_FILTER environment
variable.

Closes !105 - Update used btrfs file system commands, new minimum is
              btrfs-progs 4.5

.gitlab-ci.yml

@@ -79,29 +79,8 @@ stages:
     - make -j $nproc
     # Exclude specific unit tests which fail without being able to create
     # loop devices in Docker images.
-    - export GTEST_FILTER="-My/SupportedFileSystemsTest.Create/lvm2pv"
+    - export GTEST_FILTER=`tests/exclude_loopdev_tests.sh tests/test_SupportedFileSystems.cc`
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndReadUsage/lvm2pv"
+    - echo $GTEST_FILTER
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndReadUsage/nilfs2"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndReadLabel/lvm2pv"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndReadLabel/nilfs2"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndReadUUID/lvm2pv"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndReadUUID/nilfs2"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndWriteLabel/lvm2pv"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndWriteLabel/nilfs2"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndWriteUUID/lvm2pv"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndWriteUUID/nilfs2"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndWriteUUIDAndReadLabel/lvm2pv"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndWriteUUIDAndReadLabel/nilfs2"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndCheck/lvm2pv"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndRemove/lvm2pv"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndGrow/btrfs"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndGrow/jfs"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndGrow/lvm2pv"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndGrow/nilfs2"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndGrow/xfs"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndShrink/btrfs"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndShrink/lvm2pv"
-    - GTEST_FILTER="$GTEST_FILTER:My/SupportedFileSystemsTest.CreateAndShrink/nilfs2"
     - fgrep -v nodev /proc/filesystems | sort
     # Create needed /dev entries for unit tests in Docker images.
     - tests/makedev.sh

tests/exclude_loopdev_tests.sh

@@ -0,0 +1,49 @@
+#!/bin/sh
+# Name    : exclude_loopdev_tests.sh
+# Purpose : Generate list of tests which require loopdev so they can be
+#           excluded in GitLab Docker CI images because loop device
+#           creation fails.  Suitable for assigning directly to the
+#           GTEST_FILTER environment variable.
+# Usage   : export_GTEST_FILTER=`exclude_loopdev_tests.sh tests/test_SupportedFileSystems.cc`
+#
+# Copyright (C) 2022 Mike Fleetwood
+#
+# Copying and distribution of this file, with or without modification,
+# are permitted in any medium without royalty provided the copyright
+# notice and this notice are preserved.  This file is offered as-is,
+# without any warranty.
+
+
+awk '
+BEGIN {
+	FS = "(, )|\\(|\\)|,"
+	num_tests = 0
+	param_fsname["FS_BTRFS"]   = "btrfs"
+	param_fsname["FS_JFS"]     = "jfs"
+	param_fsname["FS_LVM2_PV"] = "lvm2pv"
+	param_fsname["FS_NILFS2"]  = "nilfs2"
+	param_fsname["FS_XFS"]     = "xfs"
+}
+/^TEST_P/ {
+	# Extract parameterised test name.
+	ptest_name = $2 "." $3
+	#printf "DEBUG: ptest_name=\"%s\"\n", ptest_name
+}
+/SKIP_IF_NOT_ROOT_FOR_REQUIRED_LOOPDEV_FOR_FS/ && ptest_name != "" {
+	# Save test name.
+	test_name[num_tests] = ptest_name "/" param_fsname[$2]
+	#printf "DEBUG: test_name[%d]=\"%s\"\n", num_tests, test_name[num_tests]
+	num_tests++
+}
+/^INSTANTIATE_TEST_CASE_P/ {
+	# Save instantiation name.
+	instance_name = $2
+}
+END {
+	printf "-"
+	for (i = 0; i < num_tests; i ++) {
+		if (i > 0) printf ":"
+		printf "%s/%s", instance_name, test_name[i]
+	}
+}
+' "${@}"