# -*- 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 probeprefix
from tracetool.backend.simple import is_string
from tracetool.format.stap import stap_escape
def global_var_name(name):
return probeprefix().replace(".", "_") + "_" + name
def generate(events, backend, group):
out('/* This file is autogenerated by tracetool, do not edit. */',
'')
for event_id, e in enumerate(events):
if 'disable' in e.properties:
continue
out('probe %(probeprefix)s.simpletrace.%(name)s = %(probeprefix)s.%(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', str(event_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()
