qemu/scripts/tracetool/format/simpletrace_stap.py
Daniel P. Berrange 80dd5c4918 trace: introduce a formal group name for trace events
The declarations in the generated-tracers.h file are
assuming there's only ever going to be one instance
of this header, as they are not namespaced. When we
have one header per event group, if a single source
file needs to include multiple sets of trace events,
the symbols will all clash.

This change thus introduces a '--group NAME' arg to the
'tracetool' program. This will cause all the symbols in
the generated header files to be given a unique namespace.

If no group is given, the group name 'common' is used,
which is suitable for the current usage where there is
only one global trace-events file used for code generation.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 1475588159-30598-21-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12 09:54:53 +02:00

92 lines
3.1 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Generate .stp file that outputs simpletrace binary traces (DTrace with SystemTAP only).
"""
__author__ = "Stefan Hajnoczi <redhat.com>"
__copyright__ = "Copyright (C) 2014, Red Hat, Inc."
__license__ = "GPL version 2 or (at your option) any later version"
__maintainer__ = "Stefan Hajnoczi"
__email__ = "stefanha@redhat.com"
from tracetool import out
from tracetool.backend.dtrace import binary, probeprefix
from tracetool.backend.simple import is_string
from tracetool.format.stap import stap_escape
def generate(events, backend, group):
out('/* This file is autogenerated by tracetool, do not edit. */',
'',
'global event_name_to_id_map',
'global event_next_id',
'function simple_trace_map_event(name)',
'',
'{',
' if (!([name] in event_name_to_id_map)) {',
' event_name_to_id_map[name] = event_next_id',
' name_len = strlen(name)',
' printf("%%8b%%8b%%4b%%.*s", 0, ',
' event_next_id, name_len, name_len, name)',
' event_next_id = event_next_id + 1',
' }',
' return event_name_to_id_map[name]',
'}',
'probe begin',
'{',
' printf("%%8b%%8b%%8b", 0xffffffffffffffff, 0xf2b177cb0aa429b4, 4)',
'}',
'')
for event_id, e in enumerate(events):
if 'disable' in e.properties:
continue
out('probe %(probeprefix)s.simpletrace.%(name)s = %(probeprefix)s.%(name)s ?',
'{',
' id = simple_trace_map_event("%(name)s")',
probeprefix=probeprefix(),
name=e.name)
# Calculate record size
sizes = ['24'] # sizeof(TraceRecord)
for type_, name in e.args:
name = stap_escape(name)
if is_string(type_):
out(' try {',
' arg%(name)s_str = %(name)s ? user_string_n(%(name)s, 512) : "<null>"',
' } catch {}',
' arg%(name)s_len = strlen(arg%(name)s_str)',
name=name)
sizes.append('4 + arg%s_len' % name)
else:
sizes.append('8')
sizestr = ' + '.join(sizes)
# Generate format string and value pairs for record header and arguments
fields = [('8b', 'id'),
('8b', 'gettimeofday_ns()'),
('4b', sizestr),
('4b', 'pid()')]
for type_, name in e.args:
name = stap_escape(name)
if is_string(type_):
fields.extend([('4b', 'arg%s_len' % name),
('.*s', 'arg%s_len, arg%s_str' % (name, name))])
else:
fields.append(('8b', name))
# Emit the entire record in a single SystemTap printf()
fmt_str = '%'.join(fmt for fmt, _ in fields)
arg_str = ', '.join(arg for _, arg in fields)
out(' printf("%%8b%%%(fmt_str)s", 1, %(arg_str)s)',
fmt_str=fmt_str, arg_str=arg_str)
out('}')
out()