xref: /linux/tools/perf/util/scripting-engines/trace-event-python.c (revision 1b85337d0685d1dc5a6f9061434ba4316d69f3b8)
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 "../debug.h"
31 #include "../evsel.h"
32 #include "../util.h"
33 #include "../event.h"
34 #include "../thread.h"
35 #include "../trace-event.h"
36 #include "../machine.h"
37 
38 PyMODINIT_FUNC initperf_trace_context(void);
39 
40 #define FTRACE_MAX_EVENT				\
41 	((1 << (sizeof(unsigned short) * 8)) - 1)
42 
43 struct event_format *events[FTRACE_MAX_EVENT];
44 
45 #define MAX_FIELDS	64
46 #define N_COMMON_FIELDS	7
47 
48 extern struct scripting_context *scripting_context;
49 
50 static char *cur_field_name;
51 static int zero_flag_atom;
52 
53 static PyObject *main_module, *main_dict;
54 
55 static void handler_call_die(const char *handler_name) NORETURN;
56 static void handler_call_die(const char *handler_name)
57 {
58 	PyErr_Print();
59 	Py_FatalError("problem in Python trace event handler");
60 	// Py_FatalError does not return
61 	// but we have to make the compiler happy
62 	abort();
63 }
64 
65 /*
66  * Insert val into into the dictionary and decrement the reference counter.
67  * This is necessary for dictionaries since PyDict_SetItemString() does not
68  * steal a reference, as opposed to PyTuple_SetItem().
69  */
70 static void pydict_set_item_string_decref(PyObject *dict, const char *key, PyObject *val)
71 {
72 	PyDict_SetItemString(dict, key, val);
73 	Py_DECREF(val);
74 }
75 
76 static PyObject *get_handler(const char *handler_name)
77 {
78 	PyObject *handler;
79 
80 	handler = PyDict_GetItemString(main_dict, handler_name);
81 	if (handler && !PyCallable_Check(handler))
82 		return NULL;
83 	return handler;
84 }
85 
86 static void call_object(PyObject *handler, PyObject *args, const char *die_msg)
87 {
88 	PyObject *retval;
89 
90 	retval = PyObject_CallObject(handler, args);
91 	if (retval == NULL)
92 		handler_call_die(die_msg);
93 	Py_DECREF(retval);
94 }
95 
96 static void try_call_object(const char *handler_name, PyObject *args)
97 {
98 	PyObject *handler;
99 
100 	handler = get_handler(handler_name);
101 	if (handler)
102 		call_object(handler, args, handler_name);
103 }
104 
105 static void define_value(enum print_arg_type field_type,
106 			 const char *ev_name,
107 			 const char *field_name,
108 			 const char *field_value,
109 			 const char *field_str)
110 {
111 	const char *handler_name = "define_flag_value";
112 	PyObject *t;
113 	unsigned long long value;
114 	unsigned n = 0;
115 
116 	if (field_type == PRINT_SYMBOL)
117 		handler_name = "define_symbolic_value";
118 
119 	t = PyTuple_New(4);
120 	if (!t)
121 		Py_FatalError("couldn't create Python tuple");
122 
123 	value = eval_flag(field_value);
124 
125 	PyTuple_SetItem(t, n++, PyString_FromString(ev_name));
126 	PyTuple_SetItem(t, n++, PyString_FromString(field_name));
127 	PyTuple_SetItem(t, n++, PyInt_FromLong(value));
128 	PyTuple_SetItem(t, n++, PyString_FromString(field_str));
129 
130 	try_call_object(handler_name, t);
131 
132 	Py_DECREF(t);
133 }
134 
135 static void define_values(enum print_arg_type field_type,
136 			  struct print_flag_sym *field,
137 			  const char *ev_name,
138 			  const char *field_name)
139 {
140 	define_value(field_type, ev_name, field_name, field->value,
141 		     field->str);
142 
143 	if (field->next)
144 		define_values(field_type, field->next, ev_name, field_name);
145 }
146 
147 static void define_field(enum print_arg_type field_type,
148 			 const char *ev_name,
149 			 const char *field_name,
150 			 const char *delim)
151 {
152 	const char *handler_name = "define_flag_field";
153 	PyObject *t;
154 	unsigned n = 0;
155 
156 	if (field_type == PRINT_SYMBOL)
157 		handler_name = "define_symbolic_field";
158 
159 	if (field_type == PRINT_FLAGS)
160 		t = PyTuple_New(3);
161 	else
162 		t = PyTuple_New(2);
163 	if (!t)
164 		Py_FatalError("couldn't create Python tuple");
165 
166 	PyTuple_SetItem(t, n++, PyString_FromString(ev_name));
167 	PyTuple_SetItem(t, n++, PyString_FromString(field_name));
168 	if (field_type == PRINT_FLAGS)
169 		PyTuple_SetItem(t, n++, PyString_FromString(delim));
170 
171 	try_call_object(handler_name, t);
172 
173 	Py_DECREF(t);
174 }
175 
176 static void define_event_symbols(struct event_format *event,
177 				 const char *ev_name,
178 				 struct print_arg *args)
179 {
180 	switch (args->type) {
181 	case PRINT_NULL:
182 		break;
183 	case PRINT_ATOM:
184 		define_value(PRINT_FLAGS, ev_name, cur_field_name, "0",
185 			     args->atom.atom);
186 		zero_flag_atom = 0;
187 		break;
188 	case PRINT_FIELD:
189 		free(cur_field_name);
190 		cur_field_name = strdup(args->field.name);
191 		break;
192 	case PRINT_FLAGS:
193 		define_event_symbols(event, ev_name, args->flags.field);
194 		define_field(PRINT_FLAGS, ev_name, cur_field_name,
195 			     args->flags.delim);
196 		define_values(PRINT_FLAGS, args->flags.flags, ev_name,
197 			      cur_field_name);
198 		break;
199 	case PRINT_SYMBOL:
200 		define_event_symbols(event, ev_name, args->symbol.field);
201 		define_field(PRINT_SYMBOL, ev_name, cur_field_name, NULL);
202 		define_values(PRINT_SYMBOL, args->symbol.symbols, ev_name,
203 			      cur_field_name);
204 		break;
205 	case PRINT_HEX:
206 		define_event_symbols(event, ev_name, args->hex.field);
207 		define_event_symbols(event, ev_name, args->hex.size);
208 		break;
209 	case PRINT_STRING:
210 		break;
211 	case PRINT_TYPE:
212 		define_event_symbols(event, ev_name, args->typecast.item);
213 		break;
214 	case PRINT_OP:
215 		if (strcmp(args->op.op, ":") == 0)
216 			zero_flag_atom = 1;
217 		define_event_symbols(event, ev_name, args->op.left);
218 		define_event_symbols(event, ev_name, args->op.right);
219 		break;
220 	default:
221 		/* gcc warns for these? */
222 	case PRINT_BSTRING:
223 	case PRINT_DYNAMIC_ARRAY:
224 	case PRINT_FUNC:
225 	case PRINT_BITMASK:
226 		/* we should warn... */
227 		return;
228 	}
229 
230 	if (args->next)
231 		define_event_symbols(event, ev_name, args->next);
232 }
233 
234 static inline struct event_format *find_cache_event(struct perf_evsel *evsel)
235 {
236 	static char ev_name[256];
237 	struct event_format *event;
238 	int type = evsel->attr.config;
239 
240 	/*
241  	 * XXX: Do we really need to cache this since now we have evsel->tp_format
242  	 * cached already? Need to re-read this "cache" routine that as well calls
243  	 * define_event_symbols() :-\
244  	 */
245 	if (events[type])
246 		return events[type];
247 
248 	events[type] = event = evsel->tp_format;
249 	if (!event)
250 		return NULL;
251 
252 	sprintf(ev_name, "%s__%s", event->system, event->name);
253 
254 	define_event_symbols(event, ev_name, event->print_fmt.args);
255 
256 	return event;
257 }
258 
259 static PyObject *get_field_numeric_entry(struct event_format *event,
260 		struct format_field *field, void *data)
261 {
262 	bool is_array = field->flags & FIELD_IS_ARRAY;
263 	PyObject *obj, *list = NULL;
264 	unsigned long long val;
265 	unsigned int item_size, n_items, i;
266 
267 	if (is_array) {
268 		list = PyList_New(field->arraylen);
269 		item_size = field->size / field->arraylen;
270 		n_items = field->arraylen;
271 	} else {
272 		item_size = field->size;
273 		n_items = 1;
274 	}
275 
276 	for (i = 0; i < n_items; i++) {
277 
278 		val = read_size(event, data + field->offset + i * item_size,
279 				item_size);
280 		if (field->flags & FIELD_IS_SIGNED) {
281 			if ((long long)val >= LONG_MIN &&
282 					(long long)val <= LONG_MAX)
283 				obj = PyInt_FromLong(val);
284 			else
285 				obj = PyLong_FromLongLong(val);
286 		} else {
287 			if (val <= LONG_MAX)
288 				obj = PyInt_FromLong(val);
289 			else
290 				obj = PyLong_FromUnsignedLongLong(val);
291 		}
292 		if (is_array)
293 			PyList_SET_ITEM(list, i, obj);
294 	}
295 	if (is_array)
296 		obj = list;
297 	return obj;
298 }
299 
300 
301 static PyObject *python_process_callchain(struct perf_sample *sample,
302 					 struct perf_evsel *evsel,
303 					 struct addr_location *al)
304 {
305 	PyObject *pylist;
306 
307 	pylist = PyList_New(0);
308 	if (!pylist)
309 		Py_FatalError("couldn't create Python list");
310 
311 	if (!symbol_conf.use_callchain || !sample->callchain)
312 		goto exit;
313 
314 	if (machine__resolve_callchain(al->machine, evsel, al->thread,
315 					   sample, NULL, NULL,
316 					   PERF_MAX_STACK_DEPTH) != 0) {
317 		pr_err("Failed to resolve callchain. Skipping\n");
318 		goto exit;
319 	}
320 	callchain_cursor_commit(&callchain_cursor);
321 
322 
323 	while (1) {
324 		PyObject *pyelem;
325 		struct callchain_cursor_node *node;
326 		node = callchain_cursor_current(&callchain_cursor);
327 		if (!node)
328 			break;
329 
330 		pyelem = PyDict_New();
331 		if (!pyelem)
332 			Py_FatalError("couldn't create Python dictionary");
333 
334 
335 		pydict_set_item_string_decref(pyelem, "ip",
336 				PyLong_FromUnsignedLongLong(node->ip));
337 
338 		if (node->sym) {
339 			PyObject *pysym  = PyDict_New();
340 			if (!pysym)
341 				Py_FatalError("couldn't create Python dictionary");
342 			pydict_set_item_string_decref(pysym, "start",
343 					PyLong_FromUnsignedLongLong(node->sym->start));
344 			pydict_set_item_string_decref(pysym, "end",
345 					PyLong_FromUnsignedLongLong(node->sym->end));
346 			pydict_set_item_string_decref(pysym, "binding",
347 					PyInt_FromLong(node->sym->binding));
348 			pydict_set_item_string_decref(pysym, "name",
349 					PyString_FromStringAndSize(node->sym->name,
350 							node->sym->namelen));
351 			pydict_set_item_string_decref(pyelem, "sym", pysym);
352 		}
353 
354 		if (node->map) {
355 			struct map *map = node->map;
356 			const char *dsoname = "[unknown]";
357 			if (map && map->dso && (map->dso->name || map->dso->long_name)) {
358 				if (symbol_conf.show_kernel_path && map->dso->long_name)
359 					dsoname = map->dso->long_name;
360 				else if (map->dso->name)
361 					dsoname = map->dso->name;
362 			}
363 			pydict_set_item_string_decref(pyelem, "dso",
364 					PyString_FromString(dsoname));
365 		}
366 
367 		callchain_cursor_advance(&callchain_cursor);
368 		PyList_Append(pylist, pyelem);
369 		Py_DECREF(pyelem);
370 	}
371 
372 exit:
373 	return pylist;
374 }
375 
376 
377 static void python_process_tracepoint(struct perf_sample *sample,
378 				      struct perf_evsel *evsel,
379 				      struct thread *thread,
380 				      struct addr_location *al)
381 {
382 	PyObject *handler, *context, *t, *obj, *callchain;
383 	PyObject *dict = NULL;
384 	static char handler_name[256];
385 	struct format_field *field;
386 	unsigned long s, ns;
387 	struct event_format *event;
388 	unsigned n = 0;
389 	int pid;
390 	int cpu = sample->cpu;
391 	void *data = sample->raw_data;
392 	unsigned long long nsecs = sample->time;
393 	const char *comm = thread__comm_str(thread);
394 
395 	t = PyTuple_New(MAX_FIELDS);
396 	if (!t)
397 		Py_FatalError("couldn't create Python tuple");
398 
399 	event = find_cache_event(evsel);
400 	if (!event)
401 		die("ug! no event found for type %d", (int)evsel->attr.config);
402 
403 	pid = raw_field_value(event, "common_pid", data);
404 
405 	sprintf(handler_name, "%s__%s", event->system, event->name);
406 
407 	handler = get_handler(handler_name);
408 	if (!handler) {
409 		dict = PyDict_New();
410 		if (!dict)
411 			Py_FatalError("couldn't create Python dict");
412 	}
413 	s = nsecs / NSECS_PER_SEC;
414 	ns = nsecs - s * NSECS_PER_SEC;
415 
416 	scripting_context->event_data = data;
417 	scripting_context->pevent = evsel->tp_format->pevent;
418 
419 	context = PyCObject_FromVoidPtr(scripting_context, NULL);
420 
421 	PyTuple_SetItem(t, n++, PyString_FromString(handler_name));
422 	PyTuple_SetItem(t, n++, context);
423 
424 	/* ip unwinding */
425 	callchain = python_process_callchain(sample, evsel, al);
426 
427 	if (handler) {
428 		PyTuple_SetItem(t, n++, PyInt_FromLong(cpu));
429 		PyTuple_SetItem(t, n++, PyInt_FromLong(s));
430 		PyTuple_SetItem(t, n++, PyInt_FromLong(ns));
431 		PyTuple_SetItem(t, n++, PyInt_FromLong(pid));
432 		PyTuple_SetItem(t, n++, PyString_FromString(comm));
433 		PyTuple_SetItem(t, n++, callchain);
434 	} else {
435 		pydict_set_item_string_decref(dict, "common_cpu", PyInt_FromLong(cpu));
436 		pydict_set_item_string_decref(dict, "common_s", PyInt_FromLong(s));
437 		pydict_set_item_string_decref(dict, "common_ns", PyInt_FromLong(ns));
438 		pydict_set_item_string_decref(dict, "common_pid", PyInt_FromLong(pid));
439 		pydict_set_item_string_decref(dict, "common_comm", PyString_FromString(comm));
440 		pydict_set_item_string_decref(dict, "common_callchain", callchain);
441 	}
442 	for (field = event->format.fields; field; field = field->next) {
443 		if (field->flags & FIELD_IS_STRING) {
444 			int offset;
445 			if (field->flags & FIELD_IS_DYNAMIC) {
446 				offset = *(int *)(data + field->offset);
447 				offset &= 0xffff;
448 			} else
449 				offset = field->offset;
450 			obj = PyString_FromString((char *)data + offset);
451 		} else { /* FIELD_IS_NUMERIC */
452 			obj = get_field_numeric_entry(event, field, data);
453 		}
454 		if (handler)
455 			PyTuple_SetItem(t, n++, obj);
456 		else
457 			pydict_set_item_string_decref(dict, field->name, obj);
458 
459 	}
460 
461 	if (!handler)
462 		PyTuple_SetItem(t, n++, dict);
463 
464 	if (_PyTuple_Resize(&t, n) == -1)
465 		Py_FatalError("error resizing Python tuple");
466 
467 	if (handler) {
468 		call_object(handler, t, handler_name);
469 	} else {
470 		try_call_object("trace_unhandled", t);
471 		Py_DECREF(dict);
472 	}
473 
474 	Py_DECREF(t);
475 }
476 
477 static void python_process_general_event(struct perf_sample *sample,
478 					 struct perf_evsel *evsel,
479 					 struct thread *thread,
480 					 struct addr_location *al)
481 {
482 	PyObject *handler, *t, *dict, *callchain, *dict_sample;
483 	static char handler_name[64];
484 	unsigned n = 0;
485 
486 	/*
487 	 * Use the MAX_FIELDS to make the function expandable, though
488 	 * currently there is only one item for the tuple.
489 	 */
490 	t = PyTuple_New(MAX_FIELDS);
491 	if (!t)
492 		Py_FatalError("couldn't create Python tuple");
493 
494 	dict = PyDict_New();
495 	if (!dict)
496 		Py_FatalError("couldn't create Python dictionary");
497 
498 	dict_sample = PyDict_New();
499 	if (!dict_sample)
500 		Py_FatalError("couldn't create Python dictionary");
501 
502 	snprintf(handler_name, sizeof(handler_name), "%s", "process_event");
503 
504 	handler = get_handler(handler_name);
505 	if (!handler)
506 		goto exit;
507 
508 	pydict_set_item_string_decref(dict, "ev_name", PyString_FromString(perf_evsel__name(evsel)));
509 	pydict_set_item_string_decref(dict, "attr", PyString_FromStringAndSize(
510 			(const char *)&evsel->attr, sizeof(evsel->attr)));
511 
512 	pydict_set_item_string_decref(dict_sample, "pid",
513 			PyInt_FromLong(sample->pid));
514 	pydict_set_item_string_decref(dict_sample, "tid",
515 			PyInt_FromLong(sample->tid));
516 	pydict_set_item_string_decref(dict_sample, "cpu",
517 			PyInt_FromLong(sample->cpu));
518 	pydict_set_item_string_decref(dict_sample, "ip",
519 			PyLong_FromUnsignedLongLong(sample->ip));
520 	pydict_set_item_string_decref(dict_sample, "time",
521 			PyLong_FromUnsignedLongLong(sample->time));
522 	pydict_set_item_string_decref(dict_sample, "period",
523 			PyLong_FromUnsignedLongLong(sample->period));
524 	pydict_set_item_string_decref(dict, "sample", dict_sample);
525 
526 	pydict_set_item_string_decref(dict, "raw_buf", PyString_FromStringAndSize(
527 			(const char *)sample->raw_data, sample->raw_size));
528 	pydict_set_item_string_decref(dict, "comm",
529 			PyString_FromString(thread__comm_str(thread)));
530 	if (al->map) {
531 		pydict_set_item_string_decref(dict, "dso",
532 			PyString_FromString(al->map->dso->name));
533 	}
534 	if (al->sym) {
535 		pydict_set_item_string_decref(dict, "symbol",
536 			PyString_FromString(al->sym->name));
537 	}
538 
539 	/* ip unwinding */
540 	callchain = python_process_callchain(sample, evsel, al);
541 	pydict_set_item_string_decref(dict, "callchain", callchain);
542 
543 	PyTuple_SetItem(t, n++, dict);
544 	if (_PyTuple_Resize(&t, n) == -1)
545 		Py_FatalError("error resizing Python tuple");
546 
547 	call_object(handler, t, handler_name);
548 exit:
549 	Py_DECREF(dict);
550 	Py_DECREF(t);
551 }
552 
553 static void python_process_event(union perf_event *event __maybe_unused,
554 				 struct perf_sample *sample,
555 				 struct perf_evsel *evsel,
556 				 struct thread *thread,
557 				 struct addr_location *al)
558 {
559 	switch (evsel->attr.type) {
560 	case PERF_TYPE_TRACEPOINT:
561 		python_process_tracepoint(sample, evsel, thread, al);
562 		break;
563 	/* Reserve for future process_hw/sw/raw APIs */
564 	default:
565 		python_process_general_event(sample, evsel, thread, al);
566 	}
567 }
568 
569 static int run_start_sub(void)
570 {
571 	main_module = PyImport_AddModule("__main__");
572 	if (main_module == NULL)
573 		return -1;
574 	Py_INCREF(main_module);
575 
576 	main_dict = PyModule_GetDict(main_module);
577 	if (main_dict == NULL)
578 		goto error;
579 	Py_INCREF(main_dict);
580 
581 	try_call_object("trace_begin", NULL);
582 
583 	return 0;
584 
585 error:
586 	Py_XDECREF(main_dict);
587 	Py_XDECREF(main_module);
588 	return -1;
589 }
590 
591 /*
592  * Start trace script
593  */
594 static int python_start_script(const char *script, int argc, const char **argv)
595 {
596 	const char **command_line;
597 	char buf[PATH_MAX];
598 	int i, err = 0;
599 	FILE *fp;
600 
601 	command_line = malloc((argc + 1) * sizeof(const char *));
602 	command_line[0] = script;
603 	for (i = 1; i < argc + 1; i++)
604 		command_line[i] = argv[i - 1];
605 
606 	Py_Initialize();
607 
608 	initperf_trace_context();
609 
610 	PySys_SetArgv(argc + 1, (char **)command_line);
611 
612 	fp = fopen(script, "r");
613 	if (!fp) {
614 		sprintf(buf, "Can't open python script \"%s\"", script);
615 		perror(buf);
616 		err = -1;
617 		goto error;
618 	}
619 
620 	err = PyRun_SimpleFile(fp, script);
621 	if (err) {
622 		fprintf(stderr, "Error running python script %s\n", script);
623 		goto error;
624 	}
625 
626 	err = run_start_sub();
627 	if (err) {
628 		fprintf(stderr, "Error starting python script %s\n", script);
629 		goto error;
630 	}
631 
632 	free(command_line);
633 
634 	return err;
635 error:
636 	Py_Finalize();
637 	free(command_line);
638 
639 	return err;
640 }
641 
642 static int python_flush_script(void)
643 {
644 	return 0;
645 }
646 
647 /*
648  * Stop trace script
649  */
650 static int python_stop_script(void)
651 {
652 	try_call_object("trace_end", NULL);
653 
654 	Py_XDECREF(main_dict);
655 	Py_XDECREF(main_module);
656 	Py_Finalize();
657 
658 	return 0;
659 }
660 
661 static int python_generate_script(struct pevent *pevent, const char *outfile)
662 {
663 	struct event_format *event = NULL;
664 	struct format_field *f;
665 	char fname[PATH_MAX];
666 	int not_first, count;
667 	FILE *ofp;
668 
669 	sprintf(fname, "%s.py", outfile);
670 	ofp = fopen(fname, "w");
671 	if (ofp == NULL) {
672 		fprintf(stderr, "couldn't open %s\n", fname);
673 		return -1;
674 	}
675 	fprintf(ofp, "# perf script event handlers, "
676 		"generated by perf script -g python\n");
677 
678 	fprintf(ofp, "# Licensed under the terms of the GNU GPL"
679 		" License version 2\n\n");
680 
681 	fprintf(ofp, "# The common_* event handler fields are the most useful "
682 		"fields common to\n");
683 
684 	fprintf(ofp, "# all events.  They don't necessarily correspond to "
685 		"the 'common_*' fields\n");
686 
687 	fprintf(ofp, "# in the format files.  Those fields not available as "
688 		"handler params can\n");
689 
690 	fprintf(ofp, "# be retrieved using Python functions of the form "
691 		"common_*(context).\n");
692 
693 	fprintf(ofp, "# See the perf-trace-python Documentation for the list "
694 		"of available functions.\n\n");
695 
696 	fprintf(ofp, "import os\n");
697 	fprintf(ofp, "import sys\n\n");
698 
699 	fprintf(ofp, "sys.path.append(os.environ['PERF_EXEC_PATH'] + \\\n");
700 	fprintf(ofp, "\t'/scripts/python/Perf-Trace-Util/lib/Perf/Trace')\n");
701 	fprintf(ofp, "\nfrom perf_trace_context import *\n");
702 	fprintf(ofp, "from Core import *\n\n\n");
703 
704 	fprintf(ofp, "def trace_begin():\n");
705 	fprintf(ofp, "\tprint \"in trace_begin\"\n\n");
706 
707 	fprintf(ofp, "def trace_end():\n");
708 	fprintf(ofp, "\tprint \"in trace_end\"\n\n");
709 
710 	while ((event = trace_find_next_event(pevent, event))) {
711 		fprintf(ofp, "def %s__%s(", event->system, event->name);
712 		fprintf(ofp, "event_name, ");
713 		fprintf(ofp, "context, ");
714 		fprintf(ofp, "common_cpu,\n");
715 		fprintf(ofp, "\tcommon_secs, ");
716 		fprintf(ofp, "common_nsecs, ");
717 		fprintf(ofp, "common_pid, ");
718 		fprintf(ofp, "common_comm,\n\t");
719 		fprintf(ofp, "common_callchain, ");
720 
721 		not_first = 0;
722 		count = 0;
723 
724 		for (f = event->format.fields; f; f = f->next) {
725 			if (not_first++)
726 				fprintf(ofp, ", ");
727 			if (++count % 5 == 0)
728 				fprintf(ofp, "\n\t");
729 
730 			fprintf(ofp, "%s", f->name);
731 		}
732 		fprintf(ofp, "):\n");
733 
734 		fprintf(ofp, "\t\tprint_header(event_name, common_cpu, "
735 			"common_secs, common_nsecs,\n\t\t\t"
736 			"common_pid, common_comm)\n\n");
737 
738 		fprintf(ofp, "\t\tprint \"");
739 
740 		not_first = 0;
741 		count = 0;
742 
743 		for (f = event->format.fields; f; f = f->next) {
744 			if (not_first++)
745 				fprintf(ofp, ", ");
746 			if (count && count % 3 == 0) {
747 				fprintf(ofp, "\" \\\n\t\t\"");
748 			}
749 			count++;
750 
751 			fprintf(ofp, "%s=", f->name);
752 			if (f->flags & FIELD_IS_STRING ||
753 			    f->flags & FIELD_IS_FLAG ||
754 			    f->flags & FIELD_IS_ARRAY ||
755 			    f->flags & FIELD_IS_SYMBOLIC)
756 				fprintf(ofp, "%%s");
757 			else if (f->flags & FIELD_IS_SIGNED)
758 				fprintf(ofp, "%%d");
759 			else
760 				fprintf(ofp, "%%u");
761 		}
762 
763 		fprintf(ofp, "\" %% \\\n\t\t(");
764 
765 		not_first = 0;
766 		count = 0;
767 
768 		for (f = event->format.fields; f; f = f->next) {
769 			if (not_first++)
770 				fprintf(ofp, ", ");
771 
772 			if (++count % 5 == 0)
773 				fprintf(ofp, "\n\t\t");
774 
775 			if (f->flags & FIELD_IS_FLAG) {
776 				if ((count - 1) % 5 != 0) {
777 					fprintf(ofp, "\n\t\t");
778 					count = 4;
779 				}
780 				fprintf(ofp, "flag_str(\"");
781 				fprintf(ofp, "%s__%s\", ", event->system,
782 					event->name);
783 				fprintf(ofp, "\"%s\", %s)", f->name,
784 					f->name);
785 			} else if (f->flags & FIELD_IS_SYMBOLIC) {
786 				if ((count - 1) % 5 != 0) {
787 					fprintf(ofp, "\n\t\t");
788 					count = 4;
789 				}
790 				fprintf(ofp, "symbol_str(\"");
791 				fprintf(ofp, "%s__%s\", ", event->system,
792 					event->name);
793 				fprintf(ofp, "\"%s\", %s)", f->name,
794 					f->name);
795 			} else
796 				fprintf(ofp, "%s", f->name);
797 		}
798 
799 		fprintf(ofp, ")\n\n");
800 
801 		fprintf(ofp, "\t\tfor node in common_callchain:");
802 		fprintf(ofp, "\n\t\t\tif 'sym' in node:");
803 		fprintf(ofp, "\n\t\t\t\tprint \"\\t[%%x] %%s\" %% (node['ip'], node['sym']['name'])");
804 		fprintf(ofp, "\n\t\t\telse:");
805 		fprintf(ofp, "\n\t\t\t\tprint \"\t[%%x]\" %% (node['ip'])\n\n");
806 		fprintf(ofp, "\t\tprint \"\\n\"\n\n");
807 
808 	}
809 
810 	fprintf(ofp, "def trace_unhandled(event_name, context, "
811 		"event_fields_dict):\n");
812 
813 	fprintf(ofp, "\t\tprint ' '.join(['%%s=%%s'%%(k,str(v))"
814 		"for k,v in sorted(event_fields_dict.items())])\n\n");
815 
816 	fprintf(ofp, "def print_header("
817 		"event_name, cpu, secs, nsecs, pid, comm):\n"
818 		"\tprint \"%%-20s %%5u %%05u.%%09u %%8u %%-20s \" %% \\\n\t"
819 		"(event_name, cpu, secs, nsecs, pid, comm),\n");
820 
821 	fclose(ofp);
822 
823 	fprintf(stderr, "generated Python script: %s\n", fname);
824 
825 	return 0;
826 }
827 
828 struct scripting_ops python_scripting_ops = {
829 	.name = "Python",
830 	.start_script = python_start_script,
831 	.flush_script = python_flush_script,
832 	.stop_script = python_stop_script,
833 	.process_event = python_process_event,
834 	.generate_script = python_generate_script,
835 };
836