perf trace: Add Perl scripting support

Implement trace_scripting_ops to make Perl a supported perf
trace scripting language.

Additionally adds code that allows Perl trace scripts to access
the 'flag' and 'symbolic' (__print_flags(), __print_symbolic())
field information parsed from the trace format files.

Also adds the Perl implementation of the generate_script()
trace_scripting_op, which creates a ready-to-run perf trace Perl
script based on existing trace data.  Scripts generated by this
implementation print out all the fields for each event mentioned
in perf.data (and will detect and generate the proper scripting
code for 'flag' and 'symbolic' fields), and will additionally
generate handlers for the special 'trace_unhandled',
'trace_begin' and 'trace_end' handlers.  Script authors can
simply remove the printing code to implement their own custom
event handling.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
Cc: anton@samba.org
Cc: hch@infradead.org
LKML-Reference: <1259133352-23685-4-git-send-email-tzanussi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 614 insertions, 5 deletions

diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 85d7163a9fd4..1f16495e5597 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -1888,7 +1888,7 @@ find_any_field(struct event *event, const char *name)
 	return find_field(event, name);
 }
 
-static unsigned long long read_size(void *ptr, int size)
+unsigned long long read_size(void *ptr, int size)
 {
 	switch (size) {
 	case 1:
@@ -1973,7 +1973,7 @@ int trace_parse_common_type(void *data)
 			      "common_type");
 }
 
-static int parse_common_pid(void *data)
+int trace_parse_common_pid(void *data)
 {
 	static int pid_offset;
 	static int pid_size;
@@ -2025,6 +2025,14 @@ struct event *trace_find_event(int id)
 	return event;
 }
 
+struct event *trace_find_next_event(struct event *event)
+{
+	if (!event)
+		return event_list;
+
+	return event->next;
+}
+
 static unsigned long long eval_num_arg(void *data, int size,
 				   struct event *event, struct print_arg *arg)
 {
@@ -2164,7 +2172,7 @@ static const struct flag flags[] = {
 	{ "HRTIMER_RESTART", 1 },
 };
 
-static unsigned long long eval_flag(const char *flag)
+unsigned long long eval_flag(const char *flag)
 {
 	int i;
 
@@ -2694,7 +2702,7 @@ get_return_for_leaf(int cpu, int cur_pid, unsigned long long cur_func,
 	if (!(event->flags & EVENT_FL_ISFUNCRET))
 		return NULL;
 
-	pid = parse_common_pid(next->data);
+	pid = trace_parse_common_pid(next->data);
 	field = find_field(event, "func");
 	if (!field)
 		die("function return does not have field func");
@@ -2980,7 +2988,7 @@ void print_event(int cpu, void *data, int size, unsigned long long nsecs,
 		return;
 	}
 
-	pid = parse_common_pid(data);
+	pid = trace_parse_common_pid(data);
 
 	if (event->flags & (EVENT_FL_ISFUNCENT | EVENT_FL_ISFUNCRET))
 		return pretty_print_func_graph(data, size, event, cpu,
diff --git a/tools/perf/util/trace-event-perl.c b/tools/perf/util/trace-event-perl.c
new file mode 100644
index 000000000000..c56b08d704da
--- /dev/null
+++ b/tools/perf/util/trace-event-perl.c
@@ -0,0 +1,552 @@
+/*
+ * trace-event-perl.  Feed perf trace events to an embedded Perl interpreter.
+ *
+ * Copyright (C) 2009 Tom Zanussi <tzanussi@gmail.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+
+#include "../perf.h"
+#include "util.h"
+#include "trace-event.h"
+#include "trace-event-perl.h"
+
+INTERP my_perl;
+
+#define FTRACE_MAX_EVENT				\
+	((1 << (sizeof(unsigned short) * 8)) - 1)
+
+struct event *events[FTRACE_MAX_EVENT];
+
+static struct scripting_context *scripting_context;
+
+static char *cur_field_name;
+static int zero_flag_atom;
+
+static void define_symbolic_value(const char *ev_name,
+				  const char *field_name,
+				  const char *field_value,
+				  const char *field_str)
+{
+	unsigned long long value;
+	dSP;
+
+	value = eval_flag(field_value);
+
+	ENTER;
+	SAVETMPS;
+	PUSHMARK(SP);
+
+	XPUSHs(sv_2mortal(newSVpv(ev_name, 0)));
+	XPUSHs(sv_2mortal(newSVpv(field_name, 0)));
+	XPUSHs(sv_2mortal(newSVuv(value)));
+	XPUSHs(sv_2mortal(newSVpv(field_str, 0)));
+
+	PUTBACK;
+	if (get_cv("main::define_symbolic_value", 0))
+		call_pv("main::define_symbolic_value", G_SCALAR);
+	SPAGAIN;
+	PUTBACK;
+	FREETMPS;
+	LEAVE;
+}
+
+static void define_symbolic_values(struct print_flag_sym *field,
+				   const char *ev_name,
+				   const char *field_name)
+{
+	define_symbolic_value(ev_name, field_name, field->value, field->str);
+	if (field->next)
+		define_symbolic_values(field->next, ev_name, field_name);
+}
+
+static void define_symbolic_field(const char *ev_name,
+				  const char *field_name)
+{
+	dSP;
+
+	ENTER;
+	SAVETMPS;
+	PUSHMARK(SP);
+
+	XPUSHs(sv_2mortal(newSVpv(ev_name, 0)));
+	XPUSHs(sv_2mortal(newSVpv(field_name, 0)));
+
+	PUTBACK;
+	if (get_cv("main::define_symbolic_field", 0))
+		call_pv("main::define_symbolic_field", G_SCALAR);
+	SPAGAIN;
+	PUTBACK;
+	FREETMPS;
+	LEAVE;
+}
+
+static void define_flag_value(const char *ev_name,
+			      const char *field_name,
+			      const char *field_value,
+			      const char *field_str)
+{
+	unsigned long long value;
+	dSP;
+
+	value = eval_flag(field_value);
+
+	ENTER;
+	SAVETMPS;
+	PUSHMARK(SP);
+
+	XPUSHs(sv_2mortal(newSVpv(ev_name, 0)));
+	XPUSHs(sv_2mortal(newSVpv(field_name, 0)));
+	XPUSHs(sv_2mortal(newSVuv(value)));
+	XPUSHs(sv_2mortal(newSVpv(field_str, 0)));
+
+	PUTBACK;
+	if (get_cv("main::define_flag_value", 0))
+		call_pv("main::define_flag_value", G_SCALAR);
+	SPAGAIN;
+	PUTBACK;
+	FREETMPS;
+	LEAVE;
+}
+
+static void define_flag_values(struct print_flag_sym *field,
+			       const char *ev_name,
+			       const char *field_name)
+{
+	define_flag_value(ev_name, field_name, field->value, field->str);
+	if (field->next)
+		define_flag_values(field->next, ev_name, field_name);
+}
+
+static void define_flag_field(const char *ev_name,
+			      const char *field_name,
+			      const char *delim)
+{
+	dSP;
+
+	ENTER;
+	SAVETMPS;
+	PUSHMARK(SP);
+
+	XPUSHs(sv_2mortal(newSVpv(ev_name, 0)));
+	XPUSHs(sv_2mortal(newSVpv(field_name, 0)));
+	XPUSHs(sv_2mortal(newSVpv(delim, 0)));
+
+	PUTBACK;
+	if (get_cv("main::define_flag_field", 0))
+		call_pv("main::define_flag_field", G_SCALAR);
+	SPAGAIN;
+	PUTBACK;
+	FREETMPS;
+	LEAVE;
+}
+
+static void define_event_symbols(struct event *event,
+				 const char *ev_name,
+				 struct print_arg *args)
+{
+	switch (args->type) {
+	case PRINT_NULL:
+		break;
+	case PRINT_ATOM:
+		define_flag_value(ev_name, cur_field_name, "0",
+				  args->atom.atom);
+		zero_flag_atom = 0;
+		break;
+	case PRINT_FIELD:
+		if (cur_field_name)
+			free(cur_field_name);
+		cur_field_name = strdup(args->field.name);
+		break;
+	case PRINT_FLAGS:
+		define_event_symbols(event, ev_name, args->flags.field);
+		define_flag_field(ev_name, cur_field_name, args->flags.delim);
+		define_flag_values(args->flags.flags, ev_name, cur_field_name);
+		break;
+	case PRINT_SYMBOL:
+		define_event_symbols(event, ev_name, args->symbol.field);
+		define_symbolic_field(ev_name, cur_field_name);
+		define_symbolic_values(args->symbol.symbols, ev_name,
+				       cur_field_name);
+		break;
+	case PRINT_STRING:
+		break;
+	case PRINT_TYPE:
+		define_event_symbols(event, ev_name, args->typecast.item);
+		break;
+	case PRINT_OP:
+		if (strcmp(args->op.op, ":") == 0)
+			zero_flag_atom = 1;
+		define_event_symbols(event, ev_name, args->op.left);
+		define_event_symbols(event, ev_name, args->op.right);
+		break;
+	default:
+		/* we should warn... */
+		return;
+	}
+
+	if (args->next)
+		define_event_symbols(event, ev_name, args->next);
+}
+
+static inline struct event *find_cache_event(int type)
+{
+	static char ev_name[256];
+	struct event *event;
+
+	if (events[type])
+		return events[type];
+
+	events[type] = event = trace_find_event(type);
+	if (!event)
+		return NULL;
+
+	sprintf(ev_name, "%s::%s", event->system, event->name);
+
+	define_event_symbols(event, ev_name, event->print_fmt.args);
+
+	return event;
+}
+
+static void perl_process_event(int cpu, void *data,
+			       int size __attribute((unused)),
+			       unsigned long long nsecs, char *comm)
+{
+	struct format_field *field;
+	static char handler[256];
+	unsigned long long val;
+	unsigned long s, ns;
+	struct event *event;
+	int type;
+	int pid;
+
+	dSP;
+
+	type = trace_parse_common_type(data);
+
+	event = find_cache_event(type);
+	if (!event)
+		die("ug! no event found for type %d", type);
+
+	pid = trace_parse_common_pid(data);
+
+	sprintf(handler, "%s::%s", event->system, event->name);
+
+	s = nsecs / NSECS_PER_SEC;
+	ns = nsecs - s * NSECS_PER_SEC;
+
+	scripting_context->event_data = data;
+
+	ENTER;
+	SAVETMPS;
+	PUSHMARK(SP);
+
+	XPUSHs(sv_2mortal(newSVpv(handler, 0)));
+	XPUSHs(sv_2mortal(newSViv(PTR2IV(scripting_context))));
+	XPUSHs(sv_2mortal(newSVuv(cpu)));
+	XPUSHs(sv_2mortal(newSVuv(s)));
+	XPUSHs(sv_2mortal(newSVuv(ns)));
+	XPUSHs(sv_2mortal(newSViv(pid)));
+	XPUSHs(sv_2mortal(newSVpv(comm, 0)));
+
+	/* common fields other than pid can be accessed via xsub fns */
+
+	for (field = event->format.fields; field; field = field->next) {
+		if (field->flags & FIELD_IS_STRING) {
+			int offset;
+			if (field->flags & FIELD_IS_DYNAMIC) {
+				offset = *(int *)(data + field->offset);
+				offset &= 0xffff;
+			} else
+				offset = field->offset;
+			XPUSHs(sv_2mortal(newSVpv((char *)data + offset, 0)));
+		} else { /* FIELD_IS_NUMERIC */
+			val = read_size(data + field->offset, field->size);
+			if (field->flags & FIELD_IS_SIGNED) {
+				XPUSHs(sv_2mortal(newSViv(val)));
+			} else {
+				XPUSHs(sv_2mortal(newSVuv(val)));
+			}
+		}
+	}
+
+	PUTBACK;
+	if (get_cv(handler, 0))
+		call_pv(handler, G_SCALAR);
+	else if (get_cv("main::trace_unhandled", 0)) {
+		XPUSHs(sv_2mortal(newSVpv(handler, 0)));
+		XPUSHs(sv_2mortal(newSViv(PTR2IV(scripting_context))));
+		XPUSHs(sv_2mortal(newSVuv(cpu)));
+		XPUSHs(sv_2mortal(newSVuv(nsecs)));
+		XPUSHs(sv_2mortal(newSViv(pid)));
+		XPUSHs(sv_2mortal(newSVpv(comm, 0)));
+		call_pv("main::trace_unhandled", G_SCALAR);
+	}
+	SPAGAIN;
+	PUTBACK;
+	FREETMPS;
+	LEAVE;
+}
+
+static void run_start_sub(void)
+{
+	dSP; /* access to Perl stack */
+	PUSHMARK(SP);
+
+	if (get_cv("main::trace_begin", 0))
+		call_pv("main::trace_begin", G_DISCARD | G_NOARGS);
+}
+
+/*
+ * Start trace script
+ */
+static int perl_start_script(const char *script)
+{
+	const char *command_line[2] = { "", NULL };
+
+	command_line[1] = script;
+
+	my_perl = perl_alloc();
+	perl_construct(my_perl);
+
+	if (perl_parse(my_perl, NULL, 2, (char **)command_line, (char **)NULL))
+		return -1;
+
+	perl_run(my_perl);
+	if (SvTRUE(ERRSV))
+		return -1;
+
+	run_start_sub();
+
+	fprintf(stderr, "perf trace started with Perl script %s\n\n", script);
+
+	return 0;
+}
+
+/*
+ * Stop trace script
+ */
+static int perl_stop_script(void)
+{
+	dSP; /* access to Perl stack */
+	PUSHMARK(SP);
+
+	if (get_cv("main::trace_end", 0))
+		call_pv("main::trace_end", G_DISCARD | G_NOARGS);
+
+	perl_destruct(my_perl);
+	perl_free(my_perl);
+
+	fprintf(stderr, "\nperf trace Perl script stopped\n");
+
+	return 0;
+}
+
+static int perl_generate_script(const char *outfile)
+{
+	struct event *event = NULL;
+	struct format_field *f;
+	char fname[PATH_MAX];
+	int not_first, count;
+	FILE *ofp;
+
+	sprintf(fname, "%s.pl", outfile);
+	ofp = fopen(fname, "w");
+	if (ofp == NULL) {
+		fprintf(stderr, "couldn't open %s\n", fname);
+		return -1;
+	}
+
+	fprintf(ofp, "# perf trace event handlers, "
+		"generated by perf trace -g perl\n");
+
+	fprintf(ofp, "# Licensed under the terms of the GNU GPL"
+		" License version 2\n\n");
+
+	fprintf(ofp, "# The common_* event handler fields are the most useful "
+		"fields common to\n");
+
+	fprintf(ofp, "# all events.  They don't necessarily correspond to "
+		"the 'common_*' fields\n");
+
+	fprintf(ofp, "# in the format files.  Those fields not available as "
+		"handler params can\n");
+
+	fprintf(ofp, "# be retrieved using Perl functions of the form "
+		"common_*($context).\n");
+
+	fprintf(ofp, "# See Context.pm for the list of available "
+		"functions.\n\n");
+
+	fprintf(ofp, "use lib \"$ENV{'PERF_EXEC_PATH'}/scripts/perl/"
+		"Perf-Trace-Util/lib\";\n");
+
+	fprintf(ofp, "use lib \"./Perf-Trace-Util/lib\";\n");
+	fprintf(ofp, "use Perf::Trace::Core;\n");
+	fprintf(ofp, "use Perf::Trace::Context;\n");
+	fprintf(ofp, "use Perf::Trace::Util;\n\n");
+
+	fprintf(ofp, "sub trace_begin\n{\n\t# optional\n}\n\n");
+	fprintf(ofp, "sub trace_end\n{\n\t# optional\n}\n\n");
+
+	while ((event = trace_find_next_event(event))) {
+		fprintf(ofp, "sub %s::%s\n{\n", event->system, event->name);
+		fprintf(ofp, "\tmy (");
+
+		fprintf(ofp, "$event_name, ");
+		fprintf(ofp, "$context, ");
+		fprintf(ofp, "$common_cpu, ");
+		fprintf(ofp, "$common_secs, ");
+		fprintf(ofp, "$common_nsecs,\n");
+		fprintf(ofp, "\t    $common_pid, ");
+		fprintf(ofp, "$common_comm,\n\t    ");
+
+		not_first = 0;
+		count = 0;
+
+		for (f = event->format.fields; f; f = f->next) {
+			if (not_first++)
+				fprintf(ofp, ", ");
+			if (++count % 5 == 0)
+				fprintf(ofp, "\n\t    ");
+
+			fprintf(ofp, "$%s", f->name);
+		}
+		fprintf(ofp, ") = @_;\n\n");
+
+		fprintf(ofp, "\tprint_header($event_name, $common_cpu, "
+			"$common_secs, $common_nsecs,\n\t             "
+			"$common_pid, $common_comm);\n\n");
+
+		fprintf(ofp, "\tprintf(\"");
+
+		not_first = 0;
+		count = 0;
+
+		for (f = event->format.fields; f; f = f->next) {
+			if (not_first++)
+				fprintf(ofp, ", ");
+			if (count && count % 4 == 0) {
+				fprintf(ofp, "\".\n\t       \"");
+			}
+			count++;
+
+			fprintf(ofp, "%s=", f->name);
+			if (f->flags & FIELD_IS_STRING ||
+			    f->flags & FIELD_IS_FLAG ||
+			    f->flags & FIELD_IS_SYMBOLIC)
+				fprintf(ofp, "%%s");
+			else if (f->flags & FIELD_IS_SIGNED)
+				fprintf(ofp, "%%d");
+			else
+				fprintf(ofp, "%%u");
+		}
+
+		fprintf(ofp, "\\n\",\n\t       ");
+
+		not_first = 0;
+		count = 0;
+
+		for (f = event->format.fields; f; f = f->next) {
+			if (not_first++)
+				fprintf(ofp, ", ");
+
+			if (++count % 5 == 0)
+				fprintf(ofp, "\n\t       ");
+
+			if (f->flags & FIELD_IS_FLAG) {
+				if ((count - 1) % 5 != 0) {
+					fprintf(ofp, "\n\t       ");
+					count = 4;
+				}
+				fprintf(ofp, "flag_str(\"");
+				fprintf(ofp, "%s::%s\", ", event->system,
+					event->name);
+				fprintf(ofp, "\"%s\", $%s)", f->name,
+					f->name);
+			} else if (f->flags & FIELD_IS_SYMBOLIC) {
+				if ((count - 1) % 5 != 0) {
+					fprintf(ofp, "\n\t       ");
+					count = 4;
+				}
+				fprintf(ofp, "symbol_str(\"");
+				fprintf(ofp, "%s::%s\", ", event->system,
+					event->name);
+				fprintf(ofp, "\"%s\", $%s)", f->name,
+					f->name);
+			} else
+				fprintf(ofp, "$%s", f->name);
+		}
+
+		fprintf(ofp, ");\n");
+		fprintf(ofp, "}\n\n");
+	}
+
+	fprintf(ofp, "sub trace_unhandled\n{\n\tmy ($event_name, $context, "
+		"$common_cpu, $common_secs, $common_nsecs,\n\t    "
+		"$common_pid, $common_comm) = @_;\n\n");
+
+	fprintf(ofp, "\tprint_header($event_name, $common_cpu, "
+		"$common_secs, $common_nsecs,\n\t             $common_pid, "
+		"$common_comm);\n}\n\n");
+
+	fprintf(ofp, "sub print_header\n{\n"
+		"\tmy ($event_name, $cpu, $secs, $nsecs, $pid, $comm) = @_;\n\n"
+		"\tprintf(\"%%-20s %%5u %%05u.%%09u %%8u %%-20s \",\n\t       "
+		"$event_name, $cpu, $secs, $nsecs, $pid, $comm);\n}");
+
+	fclose(ofp);
+
+	fprintf(stderr, "generated Perl script: %s\n", fname);
+
+	return 0;
+}
+
+struct scripting_ops perl_scripting_ops = {
+	.name = "Perl",
+	.start_script = perl_start_script,
+	.stop_script = perl_stop_script,
+	.process_event = perl_process_event,
+	.generate_script = perl_generate_script,
+};
+
+#ifdef NO_LIBPERL
+void setup_perl_scripting(void)
+{
+	fprintf(stderr, "Perl scripting not supported."
+		"  Install libperl-dev[el] and rebuild perf to get it.\n");
+}
+#else
+void setup_perl_scripting(void)
+{
+	int err;
+	err = script_spec_register("Perl", &perl_scripting_ops);
+	if (err)
+		die("error registering Perl script extension");
+
+	err = script_spec_register("pl", &perl_scripting_ops);
+	if (err)
+		die("error registering pl script extension");
+
+	scripting_context = malloc(sizeof(struct scripting_context));
+}
+#endif
diff --git a/tools/perf/util/trace-event-perl.h b/tools/perf/util/trace-event-perl.h
new file mode 100644
index 000000000000..6c94fa93013d
--- /dev/null
+++ b/tools/perf/util/trace-event-perl.h
@@ -0,0 +1,42 @@
+#ifndef __PERF_TRACE_EVENT_PERL_H
+#define __PERF_TRACE_EVENT_PERL_H
+#ifdef NO_LIBPERL
+typedef int INTERP;
+#define dSP
+#define ENTER
+#define SAVETMPS
+#define PUTBACK
+#define SPAGAIN
+#define FREETMPS
+#define LEAVE
+#define SP
+#define ERRSV
+#define G_SCALAR		(0)
+#define G_DISCARD		(0)
+#define G_NOARGS		(0)
+#define PUSHMARK(a)
+#define SvTRUE(a)		(0)
+#define XPUSHs(s)
+#define sv_2mortal(a)
+#define newSVpv(a,b)
+#define newSVuv(a)
+#define newSViv(a)
+#define get_cv(a,b)		(0)
+#define call_pv(a,b)		(0)
+#define perl_alloc()		(0)
+#define perl_construct(a)	(0)
+#define perl_parse(a,b,c,d,e)	(0)
+#define perl_run(a)		(0)
+#define perl_destruct(a)	(0)
+#define perl_free(a)		(0)
+#else
+#include <EXTERN.h>
+#include <perl.h>
+typedef PerlInterpreter * INTERP;
+#endif
+
+struct scripting_context {
+	void *event_data;
+};
+
+#endif /* __PERF_TRACE_EVENT_PERL_H */
diff --git a/tools/perf/util/trace-event.h b/tools/perf/util/trace-event.h
index aeb915778ae7..b1e58d3d947d 100644
--- a/tools/perf/util/trace-event.h
+++ b/tools/perf/util/trace-event.h
@@ -245,10 +245,14 @@ extern int latency_format;
 
 int parse_header_page(char *buf, unsigned long size);
 int trace_parse_common_type(void *data);
+int trace_parse_common_pid(void *data);
 struct event *trace_find_event(int id);
+struct event *trace_find_next_event(struct event *event);
+unsigned long long read_size(void *ptr, int size);
 unsigned long long
 raw_field_value(struct event *event, const char *name, void *data);
 void *raw_field_ptr(struct event *event, const char *name, void *data);
+unsigned long long eval_flag(const char *flag);
 
 int read_tracing_data(int fd, struct perf_event_attr *pattrs, int nb_events);
 
@@ -272,4 +276,7 @@ struct scripting_ops {
 
 int script_spec_register(const char *spec, struct scripting_ops *ops);
 
+extern struct scripting_ops perl_scripting_ops;
+void setup_perl_scripting(void);
+
 #endif /* __PERF_TRACE_EVENTS_H */