ANDROID: Collect coverage data from KUnit

kunit.sh supports --gcov. It invokes bazel and TradeFed with additional
parameters. It outputs coverage data that lcov can analyze.

Test: common/tools/testing/android/bin/kunit.sh --gcov \
      -d $PWD/out/kunit/dist
Bug: 358439710
Change-Id: If9d406ab3809f405e99508ce455f3c640a09dc01
Signed-off-by: Hsin-Yi Chen <hsinyichen@google.com>

tools/testing/android/bin/kselftest.sh

@@ -121,6 +121,8 @@ while test $# -gt 0; do
             shift
             ;;
         *)
+            echo "unknown argument: $1"
+            exit 1
             ;;
     esac
 done

tools/testing/android/bin/kunit.sh

@@ -26,6 +26,7 @@ print_help() {
     echo "                        If serial is specified, virtual device launch will be skipped"
     echo "  -t, --test=TEST_NAME  The test target name. Can be repeated"
     echo "                        If test is not specified, all tests will be run"
+    echo "  --gcov                Collect coverage data from the test result"
     echo "  -h, --help            Display this help message and exit"
     echo ""
     echo "Examples:"
@@ -44,6 +45,7 @@ SERIAL_NUMBER=
 MODULE_NAME="kunit"
 TEST_FILTERS=
 SELECTED_TESTS=
+GCOV=false
 
 while test $# -gt 0; do
     case "$1" in
@@ -114,15 +116,28 @@ while test $# -gt 0; do
             TEST_FILTERS+="--include-filter '$MODULE_NAME $TEST_NAME'"
             shift
             ;;
+        --gcov)
+            GCOV=true
+            shift
+            ;;
         *)
+            echo "unknown argument: $1"
+            exit 1
             ;;
     esac
 done
 
+# Kernel and modules must be built with the same flags.
+BUILD_FLAGS=
+if $GCOV; then
+    BUILD_FLAGS+=" --gcov"
+fi
+
 if $BUILD_KERNEL; then
     echo "Building kernel..."
     # TODO: add support to build kernel for physical device
-    $BAZEL run //common-modules/virtual-device:virtual_device_x86_64_dist --  --dist_dir=$DIST_DIR
+    $BAZEL run $BUILD_FLAGS //common-modules/virtual-device:virtual_device_x86_64_dist -- \
+    --dist_dir=$DIST_DIR
     exit_code=$?
     if [ $exit_code -eq 0 ]; then
         echo "Command succeeded"
@@ -162,11 +177,11 @@ echo "Building KUnit tests according to device $SERIAL_NUMBER ro.product.cpu.abi
 case $ABI in
 	arm64*)
         TESTSDIR+="_arm64"
-		$BAZEL run //common:kunit_tests_arm64 -- -v --destdir $TESTSDIR
+		$BAZEL run $BUILD_FLAGS //common:kunit_tests_arm64 -- -v --destdir $TESTSDIR
 		;;
 	x86_64*)
         TESTSDIR+="_x86_64"
-		$BAZEL run //common:kunit_tests_x86_64 -- -v --destdir $TESTSDIR
+		$BAZEL run $BUILD_FLAGS //common:kunit_tests_x86_64 -- -v --destdir $TESTSDIR
 		;;
 	*)
 		echo "$ABI not supported"
@@ -193,6 +208,10 @@ template/local_min --template:map test=suite/test_mapping_suite \
 $TEST_FILTERS --tests-dir=$TESTSDIR --log-file-path=$LOG_DIR \
 --primary-abi-only -s $SERIAL_NUMBER"
 
+if $GCOV; then
+    tf_cli+=" --coverage --coverage-toolchain GCOV_KERNEL --auto-collect GCOV_KERNEL_COVERAGE"
+fi
+
 echo "Runing tradefed command: $tf_cli"
 
 eval $tf_cli
@@ -201,3 +220,9 @@ if $LAUNCH_CVD && $KILL_CVD; then
     echo "Test finished. Deleting cvd instance $INSTANCE_NAME ..."
     $ACLOUD delete --instance-names $INSTANCE_NAME
 fi
+
+if $GCOV; then
+    echo "Creating tracefile ..."
+    common/tools/testing/android/bin/create-tracefile.py -t $LOG_DIR -o $LOG_DIR/cov.info && \
+    echo "Created tracefile at $LOG_DIR/cov.info"
+fi