xref: /linux/tools/perf/util/scripting-engines/trace-event-python.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  * trace-event-python.  Feed trace events to an embedded Python interpreter.
3  *
4  * Copyright (C) 2010 Tom Zanussi <tzanussi@gmail.com>
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to the Free Software
18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  *
20  */
21 
22 #include <Python.h>
23 
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <errno.h>
28 
29 #include "../../perf.h"
30 #include "../evsel.h"
31 #include "../util.h"
32 #include "../event.h"
33 #include "../thread.h"
34 #include "../trace-event.h"
35 
36 PyMODINIT_FUNC initperf_trace_context(void);
37 
38 #define FTRACE_MAX_EVENT				\
39 	((1 << (sizeof(unsigned short) * 8)) - 1)
40 
41 struct event_format *events[FTRACE_MAX_EVENT];
42 
43 #define MAX_FIELDS	64
44 #define N_COMMON_FIELDS	7
45 
46 extern struct scripting_context *scripting_context;
47 
48 static char *cur_field_name;
49 static int zero_flag_atom;
50 
51 static PyObject *main_module, *main_dict;
52 
53 static void handler_call_die(const char *handler_name)
54 {
55 	PyErr_Print();
56 	Py_FatalError("problem in Python trace event handler");
57 }
58 
59 /*
60  * Insert val into into the dictionary and decrement the reference counter.
61  * This is necessary for dictionaries since PyDict_SetItemString() does not
62  * steal a reference, as opposed to PyTuple_SetItem().
63  */
64 static void pydict_set_item_string_decref(PyObject *dict, const char *key, PyObject *val)
65 {
66 	PyDict_SetItemString(dict, key, val);
67 	Py_DECREF(val);
68 }
69 
70 static void define_value(enum print_arg_type field_type,
71 			 const char *ev_name,
72 			 const char *field_name,
73 			 const char *field_value,
74 			 const char *field_str)
75 {
76 	const char *handler_name = "define_flag_value";
77 	PyObject *handler, *t, *retval;
78 	unsigned long long value;
79 	unsigned n = 0;
80 
81 	if (field_type == PRINT_SYMBOL)
82 		handler_name = "define_symbolic_value";
83 
84 	t = PyTuple_New(4);
85 	if (!t)
86 		Py_FatalError("couldn't create Python tuple");
87 
88 	value = eval_flag(field_value);
89 
90 	PyTuple_SetItem(t, n++, PyString_FromString(ev_name));
91 	PyTuple_SetItem(t, n++, PyString_FromString(field_name));
92 	PyTuple_SetItem(t, n++, PyInt_FromLong(value));
93 	PyTuple_SetItem(t, n++, PyString_FromString(field_str));
94 
95 	handler = PyDict_GetItemString(main_dict, handler_name);
96 	if (handler && PyCallable_Check(handler)) {
97 		retval = PyObject_CallObject(handler, t);
98 		if (retval == NULL)
99 			handler_call_die(handler_name);
100 	}
101 
102 	Py_DECREF(t);
103 }
104 
105 static void define_values(enum print_arg_type field_type,
106 			  struct print_flag_sym *field,
107 			  const char *ev_name,
108 			  const char *field_name)
109 {
110 	define_value(field_type, ev_name, field_name, field->value,
111 		     field->str);
112 
113 	if (field->next)
114 		define_values(field_type, field->next, ev_name, field_name);
115 }
116 
117 static void define_field(enum print_arg_type field_type,
118 			 const char *ev_name,
119 			 const char *field_name,
120 			 const char *delim)
121 {
122 	const char *handler_name = "define_flag_field";
123 	PyObject *handler, *t, *retval;
124 	unsigned n = 0;
125 
126 	if (field_type == PRINT_SYMBOL)
127 		handler_name = "define_symbolic_field";
128 
129 	if (field_type == PRINT_FLAGS)
130 		t = PyTuple_New(3);
131 	else
132 		t = PyTuple_New(2);
133 	if (!t)
134 		Py_FatalError("couldn't create Python tuple");
135 
136 	PyTuple_SetItem(t, n++, PyString_FromString(ev_name));
137 	PyTuple_SetItem(t, n++, PyString_FromString(field_name));
138 	if (field_type == PRINT_FLAGS)
139 		PyTuple_SetItem(t, n++, PyString_FromString(delim));
140 
141 	handler = PyDict_GetItemString(main_dict, handler_name);
142 	if (handler && PyCallable_Check(handler)) {
143 		retval = PyObject_CallObject(handler, t);
144 		if (retval == NULL)
145 			handler_call_die(handler_name);
146 	}
147 
148 	Py_DECREF(t);
149 }
150 
151 static void define_event_symbols(struct event_format *event,
152 				 const char *ev_name,
153 				 struct print_arg *args)
154 {
155 	switch (args->type) {
156 	case PRINT_NULL:
157 		break;
158 	case PRINT_ATOM:
159 		define_value(PRINT_FLAGS, ev_name, cur_field_name, "0",
160 			     args->atom.atom);
161 		zero_flag_atom = 0;
162 		break;
163 	case PRINT_FIELD:
164 		if (cur_field_name)
165 			free(cur_field_name);
166 		cur_field_name = strdup(args->field.name);
167 		break;
168 	case PRINT_FLAGS:
169 		define_event_symbols(event, ev_name, args->flags.field);
170 		define_field(PRINT_FLAGS, ev_name, cur_field_name,
171 			     args->flags.delim);
172 		define_values(PRINT_FLAGS, args->flags.flags, ev_name,
173 			      cur_field_name);
174 		break;
175 	case PRINT_SYMBOL:
176 		define_event_symbols(event, ev_name, args->symbol.field);
177 		define_field(PRINT_SYMBOL, ev_name, cur_field_name, NULL);
178 		define_values(PRINT_SYMBOL, args->symbol.symbols, ev_name,
179 			      cur_field_name);
180 		break;
181 	case PRINT_HEX:
182 		define_event_symbols(event, ev_name, args->hex.field);
183 		define_event_symbols(event, ev_name, args->hex.size);
184 		break;
185 	case PRINT_STRING:
186 		break;
187 	case PRINT_TYPE:
188 		define_event_symbols(event, ev_name, args->typecast.item);
189 		break;
190 	case PRINT_OP:
191 		if (strcmp(args->op.op, ":") == 0)
192 			zero_flag_atom = 1;
193 		define_event_symbols(event, ev_name, args->op.left);
194 		define_event_symbols(event, ev_name, args->op.right);
195 		break;
196 	default:
197 		/* gcc warns for these? */
198 	case PRINT_BSTRING:
199 	case PRINT_DYNAMIC_ARRAY:
200 	case PRINT_FUNC:
201 		/* we should warn... */
202 		return;
203 	}
204 
205 	if (args->next)
206 		define_event_symbols(event, ev_name, args->next);
207 }
208 
209 static inline struct event_format *find_cache_event(struct perf_evsel *evsel)
210 {
211 	static char ev_name[256];
212 	struct event_format *event;
213 	int type = evsel->attr.config;
214 
215 	/*
216  	 * XXX: Do we really need to cache this since now we have evsel->tp_format
217  	 * cached already? Need to re-read this "cache" routine that as well calls
218  	 * define_event_symbols() :-\
219  	 */
220 	if (events[type])
221 		return events[type];
222 
223 	events[type] = event = evsel->tp_format;
224 	if (!event)
225 		return NULL;
226 
227 	sprintf(ev_name, "%s__%s", event->system, event->name);
228 
229 	define_event_symbols(event, ev_name, event->print_fmt.args);
230 
231 	return event;
232 }
233 
234 static void python_process_tracepoint(union perf_event *perf_event
235 				      __maybe_unused,
236 				 struct perf_sample *sample,
237 				 struct perf_evsel *evsel,
238 				 struct machine *machine __maybe_unused,
239 				 struct thread *thread,
240 				 struct addr_location *al)
241 {
242 	PyObject *handler, *retval, *context, *t, *obj, *dict = NULL;
243 	static char handler_name[256];
244 	struct format_field *field;
245 	unsigned long long val;
246 	unsigned long s, ns;
247 	struct event_format *event;
248 	unsigned n = 0;
249 	int pid;
250 	int cpu = sample->cpu;
251 	void *data = sample->raw_data;
252 	unsigned long long nsecs = sample->time;
253 	const char *comm = thread__comm_str(thread);
254 
255 	t = PyTuple_New(MAX_FIELDS);
256 	if (!t)
257 		Py_FatalError("couldn't create Python tuple");
258 
259 	event = find_cache_event(evsel);
260 	if (!event)
261 		die("ug! no event found for type %d", (int)evsel->attr.config);
262 
263 	pid = raw_field_value(event, "common_pid", data);
264 
265 	sprintf(handler_name, "%s__%s", event->system, event->name);
266 
267 	handler = PyDict_GetItemString(main_dict, handler_name);
268 	if (handler && !PyCallable_Check(handler))
269 		handler = NULL;
270 	if (!handler) {
271 		dict = PyDict_New();
272 		if (!dict)
273 			Py_FatalError("couldn't create Python dict");
274 	}
275 	s = nsecs / NSECS_PER_SEC;
276 	ns = nsecs - s * NSECS_PER_SEC;
277 
278 	scripting_context->event_data = data;
279 	scripting_context->pevent = evsel->tp_format->pevent;
280 
281 	context = PyCObject_FromVoidPtr(scripting_context, NULL);
282 
283 	PyTuple_SetItem(t, n++, PyString_FromString(handler_name));
284 	PyTuple_SetItem(t, n++, context);
285 
286 	if (handler) {
287 		PyTuple_SetItem(t, n++, PyInt_FromLong(cpu));
288 		PyTuple_SetItem(t, n++, PyInt_FromLong(s));
289 		PyTuple_SetItem(t, n++, PyInt_FromLong(ns));
290 		PyTuple_SetItem(t, n++, PyInt_FromLong(pid));
291 		PyTuple_SetItem(t, n++, PyString_FromString(comm));
292 	} else {
293 		pydict_set_item_string_decref(dict, "common_cpu", PyInt_FromLong(cpu));
294 		pydict_set_item_string_decref(dict, "common_s", PyInt_FromLong(s));
295 		pydict_set_item_string_decref(dict, "common_ns", PyInt_FromLong(ns));
296 		pydict_set_item_string_decref(dict, "common_pid", PyInt_FromLong(pid));
297 		pydict_set_item_string_decref(dict, "common_comm", PyString_FromString(comm));
298 	}
299 	for (field = event->format.fields; field; field = field->next) {
300 		if (field->flags & FIELD_IS_STRING) {
301 			int offset;
302 			if (field->flags & FIELD_IS_DYNAMIC) {
303 				offset = *(int *)(data + field->offset);
304 				offset &= 0xffff;
305 			} else
306 				offset = field->offset;
307 			obj = PyString_FromString((char *)data + offset);
308 		} else { /* FIELD_IS_NUMERIC */
309 			val = read_size(event, data + field->offset,
310 					field->size);
311 			if (field->flags & FIELD_IS_SIGNED) {
312 				if ((long long)val >= LONG_MIN &&
313 				    (long long)val <= LONG_MAX)
314 					obj = PyInt_FromLong(val);
315 				else
316 					obj = PyLong_FromLongLong(val);
317 			} else {
318 				if (val <= LONG_MAX)
319 					obj = PyInt_FromLong(val);
320 				else
321 					obj = PyLong_FromUnsignedLongLong(val);
322 			}
323 		}
324 		if (handler)
325 			PyTuple_SetItem(t, n++, obj);
326 		else
327 			pydict_set_item_string_decref(dict, field->name, obj);
328 
329 	}
330 	if (!handler)
331 		PyTuple_SetItem(t, n++, dict);
332 
333 	if (_PyTuple_Resize(&t, n) == -1)
334 		Py_FatalError("error resizing Python tuple");
335 
336 	if (handler) {
337 		retval = PyObject_CallObject(handler, t);
338 		if (retval == NULL)
339 			handler_call_die(handler_name);
340 	} else {
341 		handler = PyDict_GetItemString(main_dict, "trace_unhandled");
342 		if (handler && PyCallable_Check(handler)) {
343 
344 			retval = PyObject_CallObject(handler, t);
345 			if (retval == NULL)
346 				handler_call_die("trace_unhandled");
347 		}
348 		Py_DECREF(dict);
349 	}
350 
351 	Py_DECREF(t);
352 }
353 
354 static void python_process_general_event(union perf_event *perf_event
355 					 __maybe_unused,
356 					 struct perf_sample *sample,
357 					 struct perf_evsel *evsel,
358 					 struct machine *machine __maybe_unused,
359 					 struct thread *thread,
360 					 struct addr_location *al)
361 {
362 	PyObject *handler, *retval, *t, *dict;
363 	static char handler_name[64];
364 	unsigned n = 0;
365 
366 	/*
367 	 * Use the MAX_FIELDS to make the function expandable, though
368 	 * currently there is only one item for the tuple.
369 	 */
370 	t = PyTuple_New(MAX_FIELDS);
371 	if (!t)
372 		Py_FatalError("couldn't create Python tuple");
373 
374 	dict = PyDict_New();
375 	if (!dict)
376 		Py_FatalError("couldn't create Python dictionary");
377 
378 	snprintf(handler_name, sizeof(handler_name), "%s", "process_event");
379 
380 	handler = PyDict_GetItemString(main_dict, handler_name);
381 	if (!handler || !PyCallable_Check(handler))
382 		goto exit;
383 
384 	pydict_set_item_string_decref(dict, "ev_name", PyString_FromString(perf_evsel__name(evsel)));
385 	pydict_set_item_string_decref(dict, "attr", PyString_FromStringAndSize(
386 			(const char *)&evsel->attr, sizeof(evsel->attr)));
387 	pydict_set_item_string_decref(dict, "sample", PyString_FromStringAndSize(
388 			(const char *)sample, sizeof(*sample)));
389 	pydict_set_item_string_decref(dict, "raw_buf", PyString_FromStringAndSize(
390 			(const char *)sample->raw_data, sample->raw_size));
391 	pydict_set_item_string_decref(dict, "comm",
392 			PyString_FromString(thread__comm_str(thread)));
393 	if (al->map) {
394 		pydict_set_item_string_decref(dict, "dso",
395 			PyString_FromString(al->map->dso->name));
396 	}
397 	if (al->sym) {
398 		pydict_set_item_string_decref(dict, "symbol",
399 			PyString_FromString(al->sym->name));
400 	}
401 
402 	PyTuple_SetItem(t, n++, dict);
403 	if (_PyTuple_Resize(&t, n) == -1)
404 		Py_FatalError("error resizing Python tuple");
405 
406 	retval = PyObject_CallObject(handler, t);
407 	if (retval == NULL)
408 		handler_call_die(handler_name);
409 exit:
410 	Py_DECREF(dict);
411 	Py_DECREF(t);
412 }
413 
414 static void python_process_event(union perf_event *perf_event,
415 				 struct perf_sample *sample,
416 				 struct perf_evsel *evsel,
417 				 struct machine *machine,
418 				 struct thread *thread,
419 				 struct addr_location *al)
420 {
421 	switch (evsel->attr.type) {
422 	case PERF_TYPE_TRACEPOINT:
423 		python_process_tracepoint(perf_event, sample, evsel,
424 					  machine, thread, al);
425 		break;
426 	/* Reserve for future process_hw/sw/raw APIs */
427 	default:
428 		python_process_general_event(perf_event, sample, evsel,
429 					     machine, thread, al);
430 	}
431 }
432 
433 static int run_start_sub(void)
434 {
435 	PyObject *handler, *retval;
436 	int err = 0;
437 
438 	main_module = PyImport_AddModule("__main__");
439 	if (main_module == NULL)
440 		return -1;
441 	Py_INCREF(main_module);
442 
443 	main_dict = PyModule_GetDict(main_module);
444 	if (main_dict == NULL) {
445 		err = -1;
446 		goto error;
447 	}
448 	Py_INCREF(main_dict);
449 
450 	handler = PyDict_GetItemString(main_dict, "trace_begin");
451 	if (handler == NULL || !PyCallable_Check(handler))
452 		goto out;
453 
454 	retval = PyObject_CallObject(handler, NULL);
455 	if (retval == NULL)
456 		handler_call_die("trace_begin");
457 
458 	Py_DECREF(retval);
459 	return err;
460 error:
461 	Py_XDECREF(main_dict);
462 	Py_XDECREF(main_module);
463 out:
464 	return err;
465 }
466 
467 /*
468  * Start trace script
469  */
470 static int python_start_script(const char *script, int argc, const char **argv)
471 {
472 	const char **command_line;
473 	char buf[PATH_MAX];
474 	int i, err = 0;
475 	FILE *fp;
476 
477 	command_line = malloc((argc + 1) * sizeof(const char *));
478 	command_line[0] = script;
479 	for (i = 1; i < argc + 1; i++)
480 		command_line[i] = argv[i - 1];
481 
482 	Py_Initialize();
483 
484 	initperf_trace_context();
485 
486 	PySys_SetArgv(argc + 1, (char **)command_line);
487 
488 	fp = fopen(script, "r");
489 	if (!fp) {
490 		sprintf(buf, "Can't open python script \"%s\"", script);
491 		perror(buf);
492 		err = -1;
493 		goto error;
494 	}
495 
496 	err = PyRun_SimpleFile(fp, script);
497 	if (err) {
498 		fprintf(stderr, "Error running python script %s\n", script);
499 		goto error;
500 	}
501 
502 	err = run_start_sub();
503 	if (err) {
504 		fprintf(stderr, "Error starting python script %s\n", script);
505 		goto error;
506 	}
507 
508 	free(command_line);
509 
510 	return err;
511 error:
512 	Py_Finalize();
513 	free(command_line);
514 
515 	return err;
516 }
517 
518 /*
519  * Stop trace script
520  */
521 static int python_stop_script(void)
522 {
523 	PyObject *handler, *retval;
524 	int err = 0;
525 
526 	handler = PyDict_GetItemString(main_dict, "trace_end");
527 	if (handler == NULL || !PyCallable_Check(handler))
528 		goto out;
529 
530 	retval = PyObject_CallObject(handler, NULL);
531 	if (retval == NULL)
532 		handler_call_die("trace_end");
533 	else
534 		Py_DECREF(retval);
535 out:
536 	Py_XDECREF(main_dict);
537 	Py_XDECREF(main_module);
538 	Py_Finalize();
539 
540 	return err;
541 }
542 
543 static int python_generate_script(struct pevent *pevent, const char *outfile)
544 {
545 	struct event_format *event = NULL;
546 	struct format_field *f;
547 	char fname[PATH_MAX];
548 	int not_first, count;
549 	FILE *ofp;
550 
551 	sprintf(fname, "%s.py", outfile);
552 	ofp = fopen(fname, "w");
553 	if (ofp == NULL) {
554 		fprintf(stderr, "couldn't open %s\n", fname);
555 		return -1;
556 	}
557 	fprintf(ofp, "# perf script event handlers, "
558 		"generated by perf script -g python\n");
559 
560 	fprintf(ofp, "# Licensed under the terms of the GNU GPL"
561 		" License version 2\n\n");
562 
563 	fprintf(ofp, "# The common_* event handler fields are the most useful "
564 		"fields common to\n");
565 
566 	fprintf(ofp, "# all events.  They don't necessarily correspond to "
567 		"the 'common_*' fields\n");
568 
569 	fprintf(ofp, "# in the format files.  Those fields not available as "
570 		"handler params can\n");
571 
572 	fprintf(ofp, "# be retrieved using Python functions of the form "
573 		"common_*(context).\n");
574 
575 	fprintf(ofp, "# See the perf-trace-python Documentation for the list "
576 		"of available functions.\n\n");
577 
578 	fprintf(ofp, "import os\n");
579 	fprintf(ofp, "import sys\n\n");
580 
581 	fprintf(ofp, "sys.path.append(os.environ['PERF_EXEC_PATH'] + \\\n");
582 	fprintf(ofp, "\t'/scripts/python/Perf-Trace-Util/lib/Perf/Trace')\n");
583 	fprintf(ofp, "\nfrom perf_trace_context import *\n");
584 	fprintf(ofp, "from Core import *\n\n\n");
585 
586 	fprintf(ofp, "def trace_begin():\n");
587 	fprintf(ofp, "\tprint \"in trace_begin\"\n\n");
588 
589 	fprintf(ofp, "def trace_end():\n");
590 	fprintf(ofp, "\tprint \"in trace_end\"\n\n");
591 
592 	while ((event = trace_find_next_event(pevent, event))) {
593 		fprintf(ofp, "def %s__%s(", event->system, event->name);
594 		fprintf(ofp, "event_name, ");
595 		fprintf(ofp, "context, ");
596 		fprintf(ofp, "common_cpu,\n");
597 		fprintf(ofp, "\tcommon_secs, ");
598 		fprintf(ofp, "common_nsecs, ");
599 		fprintf(ofp, "common_pid, ");
600 		fprintf(ofp, "common_comm,\n\t");
601 
602 		not_first = 0;
603 		count = 0;
604 
605 		for (f = event->format.fields; f; f = f->next) {
606 			if (not_first++)
607 				fprintf(ofp, ", ");
608 			if (++count % 5 == 0)
609 				fprintf(ofp, "\n\t");
610 
611 			fprintf(ofp, "%s", f->name);
612 		}
613 		fprintf(ofp, "):\n");
614 
615 		fprintf(ofp, "\t\tprint_header(event_name, common_cpu, "
616 			"common_secs, common_nsecs,\n\t\t\t"
617 			"common_pid, common_comm)\n\n");
618 
619 		fprintf(ofp, "\t\tprint \"");
620 
621 		not_first = 0;
622 		count = 0;
623 
624 		for (f = event->format.fields; f; f = f->next) {
625 			if (not_first++)
626 				fprintf(ofp, ", ");
627 			if (count && count % 3 == 0) {
628 				fprintf(ofp, "\" \\\n\t\t\"");
629 			}
630 			count++;
631 
632 			fprintf(ofp, "%s=", f->name);
633 			if (f->flags & FIELD_IS_STRING ||
634 			    f->flags & FIELD_IS_FLAG ||
635 			    f->flags & FIELD_IS_SYMBOLIC)
636 				fprintf(ofp, "%%s");
637 			else if (f->flags & FIELD_IS_SIGNED)
638 				fprintf(ofp, "%%d");
639 			else
640 				fprintf(ofp, "%%u");
641 		}
642 
643 		fprintf(ofp, "\\n\" %% \\\n\t\t(");
644 
645 		not_first = 0;
646 		count = 0;
647 
648 		for (f = event->format.fields; f; f = f->next) {
649 			if (not_first++)
650 				fprintf(ofp, ", ");
651 
652 			if (++count % 5 == 0)
653 				fprintf(ofp, "\n\t\t");
654 
655 			if (f->flags & FIELD_IS_FLAG) {
656 				if ((count - 1) % 5 != 0) {
657 					fprintf(ofp, "\n\t\t");
658 					count = 4;
659 				}
660 				fprintf(ofp, "flag_str(\"");
661 				fprintf(ofp, "%s__%s\", ", event->system,
662 					event->name);
663 				fprintf(ofp, "\"%s\", %s)", f->name,
664 					f->name);
665 			} else if (f->flags & FIELD_IS_SYMBOLIC) {
666 				if ((count - 1) % 5 != 0) {
667 					fprintf(ofp, "\n\t\t");
668 					count = 4;
669 				}
670 				fprintf(ofp, "symbol_str(\"");
671 				fprintf(ofp, "%s__%s\", ", event->system,
672 					event->name);
673 				fprintf(ofp, "\"%s\", %s)", f->name,
674 					f->name);
675 			} else
676 				fprintf(ofp, "%s", f->name);
677 		}
678 
679 		fprintf(ofp, "),\n\n");
680 	}
681 
682 	fprintf(ofp, "def trace_unhandled(event_name, context, "
683 		"event_fields_dict):\n");
684 
685 	fprintf(ofp, "\t\tprint ' '.join(['%%s=%%s'%%(k,str(v))"
686 		"for k,v in sorted(event_fields_dict.items())])\n\n");
687 
688 	fprintf(ofp, "def print_header("
689 		"event_name, cpu, secs, nsecs, pid, comm):\n"
690 		"\tprint \"%%-20s %%5u %%05u.%%09u %%8u %%-20s \" %% \\\n\t"
691 		"(event_name, cpu, secs, nsecs, pid, comm),\n");
692 
693 	fclose(ofp);
694 
695 	fprintf(stderr, "generated Python script: %s\n", fname);
696 
697 	return 0;
698 }
699 
700 struct scripting_ops python_scripting_ops = {
701 	.name = "Python",
702 	.start_script = python_start_script,
703 	.stop_script = python_stop_script,
704 	.process_event = python_process_event,
705 	.generate_script = python_generate_script,
706 };
707