# -*- coding: utf-8 -*-
"""
Generate .stp file that printfs log messages (DTrace with SystemTAP only).
"""
__author__ = "Daniel P. Berrange <berrange@redhat.com>"
__copyright__ = "Copyright (C) 2014-2019, Red Hat, Inc."
__license__ = "GPL version 2 or (at your option) any later version"
__maintainer__ = "Daniel Berrange"
__email__ = "berrange@redhat.com"
import re
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 global_var_name(name):
return probeprefix().replace(".", "_") + "_" + name
STATE_SKIP = 0
STATE_LITERAL = 1
STATE_MACRO = 2
def c_macro_to_format(macro):
if macro.startswith("PRI"):
return macro[3]
raise Exception("Unhandled macro '%s'" % macro)
def c_fmt_to_stap(fmt):
state = 0
bits = []
literal = ""
macro = ""
escape = 0;
for i in range(len(fmt)):
if fmt[i] == '\\':
if escape:
escape = 0
else:
escape = 1
if state != STATE_LITERAL:
raise Exception("Unexpected escape outside string literal")
literal = literal + fmt[i]
elif fmt[i] == '"' and not escape:
if state == STATE_LITERAL:
state = STATE_SKIP
bits.append(literal)
literal = ""
else:
if state == STATE_MACRO:
bits.append(c_macro_to_format(macro))
macro = ""
state = STATE_LITERAL
elif fmt[i] == ' ' or fmt[i] == '\t':
if state == STATE_MACRO:
bits.append(c_macro_to_format(macro))
macro = ""
state = STATE_SKIP
elif state == STATE_LITERAL:
literal = literal + fmt[i]
else:
escape = 0
if state == STATE_SKIP:
state = STATE_MACRO
if state == STATE_LITERAL:
literal = literal + fmt[i]
else:
macro = macro + fmt[i]
if state == STATE_MACRO:
bits.append(c_macro_to_format(macro))
elif state == STATE_LITERAL:
bits.append(literal)
# All variables in systemtap are 64-bit in size
# The "%l" integer size qualifier is thus redundant
# and "%ll" is not valid at all. Similarly the size_t
# based "%z" size qualifier is not valid. We just
# strip all size qualifiers for sanity.
fmt = re.sub("%(\d*)(l+|z)(x|u|d)", "%\\1\\3", "".join(bits))
return fmt
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.log.%(name)s = %(probeprefix)s.%(name)s ?',
'{',
probeprefix=probeprefix(),
name=e.name)
# Get references to userspace strings
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 {}',
name=name)
# Determine systemtap's view of variable names
fields = ["pid()", "gettimeofday_ns()"]
for type_, name in e.args:
name = stap_escape(name)
if is_string(type_):
fields.append("arg" + name + "_str")
else:
fields.append(name)
# Emit the entire record in a single SystemTap printf()
arg_str = ', '.join(arg for arg in fields)
fmt_str = "%d@%d " + e.name + " " + c_fmt_to_stap(e.fmt) + "\\n"
out(' printf("%(fmt_str)s", %(arg_str)s)',
fmt_str=fmt_str, arg_str=arg_str)
out('}')
out()
