perf tests: Add perf script test

Start a new set of shell tests for testing perf script. The initial
contribution is checking that some perf db-export functionality works
as reported in this regression by Ben Gainey <[e-mail]>:
https://lore.kernel.org/lkml/[e-mail]/

Signed-off-by: Ian Rogers <[e-mail]>
Tested-by: Arnaldo Carvalho de Melo <[e-mail]>
Tested-by: Ben Gainey <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/tests/shell/script.sh

···
+#!/bin/sh
+# perf script tests
+# SPDX-License-Identifier: GPL-2.0
+
+set -e
+
+temp_dir=$(mktemp -d /tmp/perf-test-script.XXXXXXXXXX)
+
+perfdatafile="${temp_dir}/perf.data"
+db_test="${temp_dir}/db_test.py"
+
+err=0
+
+cleanup()
+{
+	trap - EXIT TERM INT
+	sane=$(echo "${temp_dir}" | cut -b 1-21)
+	if [ "${sane}" = "/tmp/perf-test-script" ] ; then
+		echo "--- Cleaning up ---"
+		rm -f "${temp_dir}/"*
+		rmdir "${temp_dir}"
+	fi
+}
+
+trap_cleanup()
+{
+	cleanup
+	exit 1
+}
+
+trap trap_cleanup EXIT TERM INT
+
+
+test_db()
+{
+	echo "DB test"
+
+	# Check if python script is supported
+	libpython=$(perf version --build-options | grep python | grep -cv OFF)
+	if [ "${libpython}" != "1" ] ; then
+		echo "SKIP: python scripting is not supported"
+		err=2
+		return
+	fi
+
+	cat << "_end_of_file_" > "${db_test}"
+perf_db_export_mode = True
+perf_db_export_calls = False
+perf_db_export_callchains = True
+
+def sample_table(*args):
+    print(f'sample_table({args})')
+
+def call_path_table(*args):
+    print(f'call_path_table({args}')
+_end_of_file_
+	perf record -g -o "${perfdatafile}" true
+	perf script -i "${perfdatafile}" -s "${db_test}"
+	echo "DB test [Success]"
+}
+
+test_db
+
+cleanup
+
+exit $err