blob: 13d29f1e42faf25de738a7bc028893adbee5ff90 [file] [log] [blame]
# -*- coding: utf-8 -*-
Machinery for generating tracing-related intermediate files.
__author__ = "Lluís Vilanova <>"
__copyright__ = "Copyright 2012-2017, Lluís Vilanova <>"
__license__ = "GPL version 2 or (at your option) any later version"
__maintainer__ = "Stefan Hajnoczi"
__email__ = ""
import re
import sys
import weakref
import tracetool.format
import tracetool.backend
import tracetool.transform
def error_write(*lines):
"""Write a set of error lines."""
sys.stderr.writelines("\n".join(lines) + "\n")
def error(*lines):
"""Write a set of error lines and exit."""
def out(*lines, **kwargs):
"""Write a set of output lines.
You can use kwargs as a shorthand for mapping variables when formating all
the strings in lines.
lines = [ l % kwargs for l in lines ]
sys.stdout.writelines("\n".join(lines) + "\n")
# We only want to allow standard C types or fixed sized
# integer types. We don't want QEMU specific types
# as we can't assume trace backends can resolve all the
# typedefs
# Magic substitution is done by tracetool
def validate_type(name):
bits = name.split(" ")
for bit in bits:
bit = re.sub("\*", "", bit)
if bit == "":
if bit == "const":
if bit not in ALLOWED_TYPES:
raise ValueError("Argument type '%s' is not in whitelist. "
"Only standard C types and fixed size integer "
"types should be used. struct, union, and "
"other complex pointer types should be "
"declared as 'void *'" % name)
class Arguments:
"""Event arguments description."""
def __init__(self, args):
args :
List of (type, name) tuples or Arguments objects.
self._args = []
for arg in args:
if isinstance(arg, Arguments):
def copy(self):
"""Create a new copy."""
return Arguments(list(self._args))
def build(arg_str):
"""Build and Arguments instance from an argument string.
arg_str : str
String describing the event arguments.
res = []
for arg in arg_str.split(","):
arg = arg.strip()
if not arg:
raise ValueError("Empty argument (did you forget to use 'void'?)")
if arg == 'void':
if '*' in arg:
arg_type, identifier = arg.rsplit('*', 1)
arg_type += '*'
identifier = identifier.strip()
arg_type, identifier = arg.rsplit(None, 1)
res.append((arg_type, identifier))
return Arguments(res)
def __getitem__(self, index):
if isinstance(index, slice):
return Arguments(self._args[index])
return self._args[index]
def __iter__(self):
"""Iterate over the (type, name) pairs."""
return iter(self._args)
def __len__(self):
"""Number of arguments."""
return len(self._args)
def __str__(self):
"""String suitable for declaring function arguments."""
if len(self._args) == 0:
return "void"
return ", ".join([ " ".join([t, n]) for t,n in self._args ])
def __repr__(self):
"""Evaluable string representation for this object."""
return "Arguments(\"%s\")" % str(self)
def names(self):
"""List of argument names."""
return [ name for _, name in self._args ]
def types(self):
"""List of argument types."""
return [ type_ for type_, _ in self._args ]
def casted(self):
"""List of argument names casted to their type."""
return ["(%s)%s" % (type_, name) for type_, name in self._args]
def transform(self, *trans):
"""Return a new Arguments instance with transformed types.
The types in the resulting Arguments instance are transformed according
to tracetool.transform.transform_type.
res = []
for type_, name in self._args:
res.append((tracetool.transform.transform_type(type_, *trans),
return Arguments(res)
class Event(object):
"""Event description.
name : str
The event name.
fmt : str
The event format string.
properties : set(str)
Properties of the event.
args : Arguments
The event arguments.
_CRE = re.compile("((?P<props>[\w\s]+)\s+)?"
_VALID_PROPS = set(["disable", "tcg", "tcg-trans", "tcg-exec", "vcpu"])
def __init__(self, name, props, fmt, args, orig=None,
event_trans=None, event_exec=None):
name : string
Event name.
props : list of str
Property names.
fmt : str, list of str
Event printing format string(s).
args : Arguments
Event arguments.
orig : Event or None
Original Event before transformation/generation.
event_trans : Event or None
Generated translation-time event ("tcg" property).
event_exec : Event or None
Generated execution-time event ("tcg" property).
""" = name = props
self.fmt = fmt
self.args = args
self.event_trans = event_trans
self.event_exec = event_exec
if len(args) > 10:
raise ValueError("Event '%s' has more than maximum permitted "
"argument count" % name)
if orig is None:
self.original = weakref.ref(self)
self.original = orig
unknown_props = set( - self._VALID_PROPS
if len(unknown_props) > 0:
raise ValueError("Unknown properties: %s"
% ", ".join(unknown_props))
assert isinstance(self.fmt, str) or len(self.fmt) == 2
def copy(self):
"""Create a new copy."""
return Event(, list(, self.fmt,
self.args.copy(), self, self.event_trans, self.event_exec)
def build(line_str):
"""Build an Event instance from a string.
line_str : str
Line describing the event.
m = Event._CRE.match(line_str)
assert m is not None
groups = m.groupdict('')
name = groups["name"]
props = groups["props"].split()
fmt = groups["fmt"]
fmt_trans = groups["fmt_trans"]
if fmt.find("%m") != -1 or fmt_trans.find("%m") != -1:
raise ValueError("Event format '%m' is forbidden, pass the error "
"as an explicit trace argument")
if fmt.endswith(r'\n"'):
raise ValueError("Event format must not end with a newline "
if len(fmt_trans) > 0:
fmt = [fmt_trans, fmt]
args =["args"])
if "tcg-trans" in props:
raise ValueError("Invalid property 'tcg-trans'")
if "tcg-exec" in props:
raise ValueError("Invalid property 'tcg-exec'")
if "tcg" not in props and not isinstance(fmt, str):
raise ValueError("Only events with 'tcg' property can have two format strings")
if "tcg" in props and isinstance(fmt, str):
raise ValueError("Events with 'tcg' property must have two format strings")
event = Event(name, props, fmt, args)
# add implicit arguments when using the 'vcpu' property
import tracetool.vcpu
event = tracetool.vcpu.transform_event(event)
return event
def __repr__(self):
"""Evaluable string representation for this object."""
if isinstance(self.fmt, str):
fmt = self.fmt
fmt = "%s, %s" % (self.fmt[0], self.fmt[1])
return "Event('%s %s(%s) %s')" % (" ".join(,,
# Star matching on PRI is dangerous as one might have multiple
# arguments with that format, hence the non-greedy version of it.
_FMT = re.compile("(%[\d\.]*\w+|%.*?PRI\S+)")
def formats(self):
"""List conversion specifiers in the argument print format string."""
assert not isinstance(self.fmt, list)
return self._FMT.findall(self.fmt)
QEMU_TRACE = "trace_%(name)s"
def api(self, fmt=None):
if fmt is None:
fmt = Event.QEMU_TRACE
return fmt % {"name":, "NAME":}
def transform(self, *trans):
"""Return a new Event with transformed Arguments."""
return Event(,
def read_events(fobj, fname):
"""Generate the output for the given (format, backends) pair.
fobj : file
Event description file.
fname : str
Name of event file
Returns a list of Event objects
events = []
for lineno, line in enumerate(fobj, 1):
if line[-1] != '\n':
raise ValueError("%s does not end with a new line" % fname)
if not line.strip():
if line.lstrip().startswith('#'):
event =
except ValueError as e:
arg0 = 'Error at %s:%d: %s' % (fname, lineno, e.args[0])
e.args = (arg0,) + e.args[1:]
# transform TCG-enabled events
if "tcg" not in
event_trans = event.copy() += "_trans" += ["tcg-trans"]
event_trans.fmt = event.fmt[0]
# ignore TCG arguments
args_trans = []
for atrans, aorig in zip(
if atrans == aorig:
event_trans.args = Arguments(args_trans)
event_exec = event.copy() += "_exec" += ["tcg-exec"]
event_exec.fmt = event.fmt[1]
event_exec.args = event_exec.args.transform(tracetool.transform.TCG_2_HOST)
new_event = [event_trans, event_exec]
event.event_trans, event.event_exec = new_event
return events
class TracetoolError (Exception):
"""Exception for calls to generate."""
def try_import(mod_name, attr_name=None, attr_default=None):
"""Try to import a module and get an attribute from it.
mod_name : str
Module name.
attr_name : str, optional
Name of an attribute in the module.
attr_default : optional
Default value if the attribute does not exist in the module.
A pair indicating whether the module could be imported and the module or
object or attribute value.
module = __import__(mod_name, globals(), locals(), ["__package__"])
if attr_name is None:
return True, module
return True, getattr(module, str(attr_name), attr_default)
except ImportError:
return False, None
def generate(events, group, format, backends,
binary=None, probe_prefix=None):
"""Generate the output for the given (format, backends) pair.
events : list
list of Event objects to generate for
group: str
Name of the tracing group
format : str
Output format name.
backends : list
Output backend names.
binary : str or None
See tracetool.backend.dtrace.BINARY.
probe_prefix : str or None
See tracetool.backend.dtrace.PROBEPREFIX.
# fix strange python error (UnboundLocalError tracetool)
import tracetool
format = str(format)
if len(format) == 0:
raise TracetoolError("format not set")
if not tracetool.format.exists(format):
raise TracetoolError("unknown format: %s" % format)
if len(backends) == 0:
raise TracetoolError("no backends specified")
for backend in backends:
if not tracetool.backend.exists(backend):
raise TracetoolError("unknown backend: %s" % backend)
backend = tracetool.backend.Wrapper(backends, format)
import tracetool.backend.dtrace
tracetool.backend.dtrace.BINARY = binary
tracetool.backend.dtrace.PROBEPREFIX = probe_prefix
tracetool.format.generate(events, format, backend, group)