perf test: Use common python setup library

Avoid replicated logic by having a common library to set the PYTHON
environment variable.

Reviewed-by: Athira Jajeev <[e-mail]>
Signed-off-by: Ian Rogers <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Kan Liang <[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/lib/setup_python.sh

···
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+if [ "x$PYTHON" = "x" ]
+then
+  python3 --version >/dev/null 2>&1 && PYTHON=python3
+fi
+if [ "x$PYTHON" = "x" ]
+then
+  python --version >/dev/null 2>&1 && PYTHON=python
+fi
+if [ "x$PYTHON" = "x" ]
+then
+  echo Skipping test, python not detected please set environment variable PYTHON.
+  exit 2
+fi

tools/perf/tests/shell/stat+json_output.sh

···
 
 skip_test=0
 
+shelldir=$(dirname "$0")
+# shellcheck source=lib/setup_python.sh
+. "${shelldir}"/lib/setup_python.sh
 pythonchecker=$(dirname $0)/lib/perf_json_output_lint.py
-if [ "x$PYTHON" == "x" ]
-then
-	if which python3 > /dev/null
-	then
-		PYTHON=python3
-	elif which python > /dev/null
-	then
-		PYTHON=python
-	else
-		echo Skipping test, python not detected please set environment variable PYTHON.
-		exit 2
-	fi
-fi
 
 stat_output=$(mktemp /tmp/__perf_test.stat_output.json.XXXXX)
 

tools/perf/tests/shell/stat_metrics_values.sh

···
 #!/bin/bash
 # perf metrics value validation
 # SPDX-License-Identifier: GPL-2.0
-if [ "x$PYTHON" == "x" ]
-then
-	if which python3 > /dev/null
-	then
-		PYTHON=python3
-	else
-		echo Skipping test, python3 not detected please set environment variable PYTHON.
-		exit 2
-	fi
-fi
+
+shelldir=$(dirname "$0")
+# shellcheck source=lib/setup_python.sh
+. "${shelldir}"/lib/setup_python.sh
 
 grep -q GenuineIntel /proc/cpuinfo || { echo Skipping non-Intel; exit 2; }
 

tools/perf/tests/shell/test_perf_data_converter_json.sh

···
 
 err=0
 
-if [ "$PYTHON" = "" ] ; then
-	if which python3 > /dev/null ; then
-		PYTHON=python3
-	elif which python > /dev/null ; then
-		PYTHON=python
-	else
-		echo Skipping test, python not detected please set environment variable PYTHON.
-		exit 2
-	fi
-fi
+shelldir=$(dirname "$0")
+# shellcheck source=lib/setup_python.sh
+. "${shelldir}"/lib/setup_python.sh
 
 perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX)
 result=$(mktemp /tmp/__perf_test.output.json.XXXXX)