#!/usr/bin/env python # -*- coding: utf-8 -*- """ Machinery for generating tracing-related intermediate files. """ __author__ = "Lluís Vilanova " __copyright__ = "Copyright 2012-2014, Lluís Vilanova " __license__ = "GPL version 2 or (at your option) any later version" __maintainer__ = "Stefan Hajnoczi" __email__ = "stefanha@linux.vnet.ibm.com" import re import sys import tracetool.format import tracetool.backend 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.""" error_write(*lines) sys.exit(1) 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") class Arguments: """Event arguments description.""" def __init__(self, args): """ Parameters ---------- args : List of (type, name) tuples. """ self._args = args def copy(self): """Create a new copy.""" return Arguments(list(self._args)) @staticmethod def build(arg_str): """Build and Arguments instance from an argument string. Parameters ---------- arg_str : str String describing the event arguments. """ res = [] for arg in arg_str.split(","): arg = arg.strip() if arg == 'void': continue if '*' in arg: arg_type, identifier = arg.rsplit('*', 1) arg_type += '*' identifier = identifier.strip() else: arg_type, identifier = arg.rsplit(None, 1) res.append((arg_type, identifier)) return Arguments(res) 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" else: 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 ] class Event(object): """Event description. Attributes ---------- 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.*)\s+)?(?P[^(\s]+)\((?P[^)]*)\)\s*(?P\".*)?") _VALID_PROPS = set(["disable"]) def __init__(self, name, props, fmt, args): """ Parameters ---------- name : string Event name. props : list of str Property names. fmt : str Event printing format. args : Arguments Event arguments. """ self.name = name self.properties = props self.fmt = fmt self.args = args unknown_props = set(self.properties) - self._VALID_PROPS if len(unknown_props) > 0: raise ValueError("Unknown properties: %s" % ", ".join(unknown_props)) def copy(self): """Create a new copy.""" return Event(self.name, list(self.properties), self.fmt, self.args.copy(), self) @staticmethod def build(line_str): """Build an Event instance from a string. Parameters ---------- 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"] args = Arguments.build(groups["args"]) return Event(name, props, fmt, args) def __repr__(self): """Evaluable string representation for this object.""" return "Event('%s %s(%s) %s')" % (" ".join(self.properties), self.name, self.args, self.fmt) QEMU_TRACE = "trace_%(name)s" def api(self, fmt=None): if fmt is None: fmt = Event.QEMU_TRACE return fmt % {"name": self.name} def _read_events(fobj): res = [] for line in fobj: if not line.strip(): continue if line.lstrip().startswith('#'): continue res.append(Event.build(line)) return res class TracetoolError (Exception): """Exception for calls to generate.""" pass def try_import(mod_name, attr_name=None, attr_default=None): """Try to import a module and get an attribute from it. Parameters ---------- 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. Returns ------- A pair indicating whether the module could be imported and the module or object or attribute value. """ try: 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(fevents, format, backend, binary=None, probe_prefix=None): """Generate the output for the given (format, backend) pair. Parameters ---------- fevents : file Event description file. format : str Output format name. backend : str Output backend name. 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) is 0: raise TracetoolError("format not set") if not tracetool.format.exists(format): raise TracetoolError("unknown format: %s" % format) format = format.replace("-", "_") backend = str(backend) if len(backend) is 0: raise TracetoolError("backend not set") if not tracetool.backend.exists(backend): raise TracetoolError("unknown backend: %s" % backend) backend = backend.replace("-", "_") if not tracetool.backend.compatible(backend, format): raise TracetoolError("backend '%s' not compatible with format '%s'" % (backend, format)) import tracetool.backend.dtrace tracetool.backend.dtrace.BINARY = binary tracetool.backend.dtrace.PROBEPREFIX = probe_prefix events = _read_events(fevents) if backend == "nop": ( e.properies.add("disable") for e in events ) tracetool.format.generate_begin(format, events) tracetool.backend.generate("nop", format, [ e for e in events if "disable" in e.properties ]) tracetool.backend.generate(backend, format, [ e for e in events if "disable" not in e.properties ]) tracetool.format.generate_end(format, events)