[PATCH v1 0/3] perf script engine testing

[PATCH v1 0/3] perf script engine testing

[Ian Rogers]

Add tests for generating a script and that the basic APIs work. I'd
grown concerned that refactoring patches may inadvertently break perf
script engine support, particularly for perl, and this does something
to prevent this.

Ian Rogers (3):
  perf script: Allow the generated script to be a path
  perf test script: Add perl script testing support
  perf test script: Add python script testing support

 tools/perf/Documentation/perf-script.txt |   6 +-
 tools/perf/builtin-script.c              |  24 ++++-
 tools/perf/tests/shell/script_perl.sh    | 102 ++++++++++++++++++++
 tools/perf/tests/shell/script_python.sh  | 113 +++++++++++++++++++++++
 4 files changed, 239 insertions(+), 6 deletions(-)
 create mode 100755 tools/perf/tests/shell/script_perl.sh
 create mode 100755 tools/perf/tests/shell/script_python.sh

-- 
2.53.0.rc2.204.g2597b5adb4-goog

[PATCH v1 1/3] perf script: Allow the generated script to be a path

[Ian Rogers]

Allow the script generated by "perf script -g <language>" to be a file
path and the language determined by the file extension. This is useful
in testing so that the generated script file can be written to a test
directory.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Documentation/perf-script.txt |  6 ++++--
 tools/perf/builtin-script.c              | 24 ++++++++++++++++++++----
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt
index 03d112960632..ddf92f9c7821 100644
--- a/tools/perf/Documentation/perf-script.txt
+++ b/tools/perf/Documentation/perf-script.txt
@@ -98,8 +98,10 @@ OPTIONS
 
 -g::
 --gen-script=::
-        Generate perf-script.[ext] starter script for given language,
-        using current perf.data.
+	Generate a starter script. If a language is given then the
+        script is named perf-script.[ext] according to the
+        language. If a file path is given then python is used for
+        files ending '.py' and perl used for files ending '.pl'.
 
 --dlfilter=<file>::
 	Filter sample events using the given shared object file.
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 14c6f6c3c4f2..7c743a303507 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -4489,6 +4489,7 @@ int cmd_script(int argc, const char **argv)
 	if (generate_script_lang) {
 		struct stat perf_stat;
 		int input;
+		char *filename = strdup("perf-script");
 
 		if (output_set_by_user()) {
 			fprintf(stderr,
@@ -4516,17 +4517,32 @@ int cmd_script(int argc, const char **argv)
 		}
 
 		scripting_ops = script_spec__lookup(generate_script_lang);
+		if (!scripting_ops && ends_with(generate_script_lang, ".py")) {
+			scripting_ops = script_spec__lookup("python");
+			free(filename);
+			filename = strdup(generate_script_lang);
+			filename[strlen(filename) - 3] = '\0';
+		} else if (!scripting_ops && ends_with(generate_script_lang, ".pl")) {
+			scripting_ops = script_spec__lookup("perl");
+			free(filename);
+			filename = strdup(generate_script_lang);
+			filename[strlen(filename) - 3] = '\0';
+		}
 		if (!scripting_ops) {
-			fprintf(stderr, "invalid language specifier");
+			fprintf(stderr, "invalid language specifier '%s'\n", generate_script_lang);
 			err = -ENOENT;
 			goto out_delete;
 		}
+		if (!filename) {
+			err = -ENOMEM;
+			goto out_delete;
+		}
 #ifdef HAVE_LIBTRACEEVENT
-		err = scripting_ops->generate_script(session->tevent.pevent,
-						     "perf-script");
+		err = scripting_ops->generate_script(session->tevent.pevent, filename);
 #else
-		err = scripting_ops->generate_script(NULL, "perf-script");
+		err = scripting_ops->generate_script(NULL, filename);
 #endif
+		free(filename);
 		goto out_delete;
 	}
 
-- 
2.53.0.rc2.204.g2597b5adb4-goog

[PATCH v1 2/3] perf test script: Add perl script testing support

[Ian Rogers]

Basic coverage of perl script support from `perf script`. This is
disabled by default and so the test will most normally skip.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/tests/shell/script_perl.sh | 102 ++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100755 tools/perf/tests/shell/script_perl.sh

diff --git a/tools/perf/tests/shell/script_perl.sh b/tools/perf/tests/shell/script_perl.sh
new file mode 100755
index 000000000000..b6d65b6fbda1
--- /dev/null
+++ b/tools/perf/tests/shell/script_perl.sh
@@ -0,0 +1,102 @@
+#!/bin/bash
+# perf script perl tests
+# SPDX-License-Identifier: GPL-2.0
+
+set -e
+
+# set PERF_EXEC_PATH to find scripts in the source directory
+perfdir=$(dirname "$0")/../..
+if [ -e "$perfdir/scripts/perl/Perf-Trace-Util" ]; then
+  export PERF_EXEC_PATH=$perfdir
+fi
+
+
+perfdata=$(mktemp /tmp/__perf_test_script_perl.perf.data.XXXXX)
+generated_script=$(mktemp /tmp/__perf_test_script.XXXXX.pl)
+
+cleanup() {
+  rm -f "${perfdata}"
+  rm -f "${generated_script}"
+  trap - EXIT TERM INT
+}
+
+trap_cleanup() {
+  echo "Unexpected signal in ${FUNCNAME[1]}"
+  cleanup
+  exit 1
+}
+trap trap_cleanup TERM INT
+trap cleanup EXIT
+
+check_perl_support() {
+	if perf check feature -q libperl; then
+		return 0
+	fi
+	echo "perf script perl test [Skipped: no libperl support]"
+	return 2
+}
+
+test_script() {
+	local event_name=$1
+	local expected_output=$2
+	local record_opts=$3
+
+	echo "Testing event: $event_name"
+
+	# Try to record. If this fails, it might be permissions or lack of support.
+	# We return 2 to indicate "skip this event" rather than "fail test".
+	if ! perf record -o "${perfdata}" -e "$event_name" $record_opts -- perf test -w thloop > /dev/null 2>&1; then
+		echo "perf script perl test [Skipped: failed to record $event_name]"
+		return 2
+	fi
+
+	echo "Generating perl script..."
+	if ! perf script -i "${perfdata}" -g "${generated_script}"; then
+		echo "perf script perl test [Failed: script generation for $event_name]"
+		return 1
+	fi
+
+	if [ ! -f "${generated_script}" ]; then
+		echo "perf script perl test [Failed: script not generated for $event_name]"
+		return 1
+	fi
+
+	echo "Executing perl script..."
+	output=$(perf script -i "${perfdata}" -s "${generated_script}" 2>&1)
+
+	if echo "$output" | grep -q "$expected_output"; then
+		echo "perf script perl test [Success: $event_name triggered $expected_output]"
+		return 0
+	else
+		echo "perf script perl test [Failed: $event_name did not trigger $expected_output]"
+		echo "Output was:"
+		echo "$output" | head -n 20
+		return 1
+	fi
+}
+
+check_perl_support || exit 2
+
+# Try tracepoint first
+test_script "sched:sched_switch" "sched::sched_switch" "-c 1" && res=0 || res=$?
+
+if [ $res -eq 0 ]; then
+	exit 0
+elif [ $res -eq 1 ]; then
+	exit 1
+fi
+
+# If tracepoint skipped (res=2), try task-clock
+# For generic events like task-clock, the generated script uses process_event()
+# which dumps data using Data::Dumper. We check for "$VAR1" which is standard Dumper output.
+test_script "task-clock" "\$VAR1" "-c 100" && res=0 || res=$?
+
+if [ $res -eq 0 ]; then
+	exit 0
+elif [ $res -eq 1 ]; then
+	exit 1
+fi
+
+# If both skipped
+echo "perf script perl test [Skipped: Could not record tracepoint or task-clock]"
+exit 2
-- 
2.53.0.rc2.204.g2597b5adb4-goog

[PATCH v1 3/3] perf test script: Add python script testing support

[Ian Rogers]

Basic coverage of python script support from `perf script`.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/tests/shell/script_python.sh | 113 ++++++++++++++++++++++++
 1 file changed, 113 insertions(+)
 create mode 100755 tools/perf/tests/shell/script_python.sh

diff --git a/tools/perf/tests/shell/script_python.sh b/tools/perf/tests/shell/script_python.sh
new file mode 100755
index 000000000000..6bc66074a31f
--- /dev/null
+++ b/tools/perf/tests/shell/script_python.sh
@@ -0,0 +1,113 @@
+#!/bin/bash
+# perf script python tests
+# SPDX-License-Identifier: GPL-2.0
+
+set -e
+
+# set PERF_EXEC_PATH to find scripts in the source directory
+perfdir=$(dirname "$0")/../..
+if [ -e "$perfdir/scripts/python/Perf-Trace-Util" ]; then
+  export PERF_EXEC_PATH=$perfdir
+fi
+
+
+perfdata=$(mktemp /tmp/__perf_test_script_python.perf.data.XXXXX)
+generated_script=$(mktemp /tmp/__perf_test_script.XXXXX.py)
+
+cleanup() {
+  rm -f "${perfdata}"
+  rm -f "${generated_script}"
+  trap - EXIT TERM INT
+}
+
+trap_cleanup() {
+  echo "Unexpected signal in ${FUNCNAME[1]}"
+  cleanup
+  exit 1
+}
+trap trap_cleanup TERM INT
+trap cleanup EXIT
+
+check_python_support() {
+	if perf check feature -q libpython; then
+		return 0
+	fi
+	echo "perf script python test [Skipped: no libpython support]"
+	return 2
+}
+
+test_script() {
+	local event_name=$1
+	local expected_output=$2
+	local record_opts=$3
+
+	echo "Testing event: $event_name"
+
+	# Try to record. If this fails, it might be permissions or lack of
+	# support. Return 2 to indicate "skip this event" rather than "fail
+	# test".
+	if ! perf record -o "${perfdata}" -e "$event_name" $record_opts -- perf test -w thloop > /dev/null 2>&1; then
+		echo "perf script python test [Skipped: failed to record $event_name]"
+		return 2
+	fi
+
+	echo "Generating python script..."
+	if ! perf script -i "${perfdata}" -g "${generated_script}"; then
+		echo "perf script python test [Failed: script generation for $event_name]"
+		return 1
+	fi
+
+	if [ ! -f "${generated_script}" ]; then
+		echo "perf script python test [Failed: script not generated for $event_name]"
+		return 1
+	fi
+
+	# Perf script -g python doesn't generate process_event for generic
+	# events so append it manually to test that the callback works.
+	if ! grep -q "def process_event" "${generated_script}"; then
+		cat <<EOF >> "${generated_script}"
+
+def process_event(param_dict):
+	print("param_dict: %s" % param_dict)
+EOF
+	fi
+
+	echo "Executing python script..."
+	output=$(perf script -i "${perfdata}" -s "${generated_script}" 2>&1)
+
+	if echo "$output" | grep -q "$expected_output"; then
+		echo "perf script python test [Success: $event_name triggered $expected_output]"
+		return 0
+	else
+		echo "perf script python test [Failed: $event_name did not trigger $expected_output]"
+		echo "Output was:"
+		echo "$output" | head -n 20
+		return 1
+	fi
+}
+
+check_python_support || exit 2
+
+# Try tracepoint first
+test_script "sched:sched_switch" "sched__sched_switch" "-c 1" && res=0 || res=$?
+
+if [ $res -eq 0 ]; then
+	exit 0
+elif [ $res -eq 1 ]; then
+	exit 1
+fi
+
+# If tracepoint skipped (res=2), try task-clock
+# For generic events like task-clock, the generated script uses process_event()
+# which prints the param_dict.
+test_script "task-clock" "param_dict" "-c 100" && res=0 || res=$?
+
+if [ $res -eq 0 ]; then
+	exit 0
+elif [ $res -eq 1 ]; then
+	exit 1
+fi
+
+# If both skipped
+echo "perf script python test [Skipped: Could not record tracepoint or task-clock]"
+exit 2
-- 
2.53.0.rc2.204.g2597b5adb4-goog

Re: [PATCH v1 0/3] perf script engine testing

[Arnaldo Carvalho de Melo]

On Mon, Feb 09, 2026 at 12:22:05PM -0800, Ian Rogers wrote:
> Add tests for generating a script and that the basic APIs work. I'd
> grown concerned that refactoring patches may inadvertently break perf
> script engine support, particularly for perl, and this does something
> to prevent this.

Thanks, tested and applied to perf-tools-next,

- Arnaldo
 
> Ian Rogers (3):
>   perf script: Allow the generated script to be a path
>   perf test script: Add perl script testing support
>   perf test script: Add python script testing support
> 
>  tools/perf/Documentation/perf-script.txt |   6 +-
>  tools/perf/builtin-script.c              |  24 ++++-
>  tools/perf/tests/shell/script_perl.sh    | 102 ++++++++++++++++++++
>  tools/perf/tests/shell/script_python.sh  | 113 +++++++++++++++++++++++
>  4 files changed, 239 insertions(+), 6 deletions(-)
>  create mode 100755 tools/perf/tests/shell/script_perl.sh
>  create mode 100755 tools/perf/tests/shell/script_python.sh
> 
> -- 
> 2.53.0.rc2.204.g2597b5adb4-goog
>