scripts/tracetool/__init__.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3
   4 """
   5 Machinery for generating tracing-related intermediate files.
   6 """
   7
   8 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
   9 __copyright__  = "Copyright 2012-2017, Lluís Vilanova <vilanova@ac.upc.edu>"
  10 __license__    = "GPL version 2 or (at your option) any later version"
  11
  12 __maintainer__ = "Stefan Hajnoczi"
  13 __email__      = "stefanha@linux.vnet.ibm.com"
  14
  15
  16 import re
  17 import sys
  18 import weakref
  19
  20 import tracetool.format
  21 import tracetool.backend
  22 import tracetool.transform
  23
  24
  25 def error_write(*lines):
  26     """Write a set of error lines."""
  27     sys.stderr.writelines("\n".join(lines) + "\n")
  28
  29 def error(*lines):
  30     """Write a set of error lines and exit."""
  31     error_write(*lines)
  32     sys.exit(1)
  33
  34
  35 def out(*lines, **kwargs):
  36     """Write a set of output lines.
  37
  38     You can use kwargs as a shorthand for mapping variables when formating all
  39     the strings in lines.
  40     """
  41     lines = [ l % kwargs for l in lines ]
  42     sys.stdout.writelines("\n".join(lines) + "\n")
  43
  44
  45 class Arguments:
  46     """Event arguments description."""
  47
  48     def __init__(self, args):
  49         """
  50         Parameters
  51         ----------
  52         args :
  53             List of (type, name) tuples or Arguments objects.
  54         """
  55         self._args = []
  56         for arg in args:
  57             if isinstance(arg, Arguments):
  58                 self._args.extend(arg._args)
  59             else:
  60                 self._args.append(arg)
  61
  62     def copy(self):
  63         """Create a new copy."""
  64         return Arguments(list(self._args))
  65
  66     @staticmethod
  67     def build(arg_str):
  68         """Build and Arguments instance from an argument string.
  69
  70         Parameters
  71         ----------
  72         arg_str : str
  73             String describing the event arguments.
  74         """
  75         res = []
  76         for arg in arg_str.split(","):
  77             arg = arg.strip()
  78             if not arg:
  79                 raise ValueError("Empty argument (did you forget to use 'void'?)")
  80             if arg == 'void':
  81                 continue
  82
  83             if '*' in arg:
  84                 arg_type, identifier = arg.rsplit('*', 1)
  85                 arg_type += '*'
  86                 identifier = identifier.strip()
  87             else:
  88                 arg_type, identifier = arg.rsplit(None, 1)
  89
  90             res.append((arg_type, identifier))
  91         return Arguments(res)
  92
  93     def __getitem__(self, index):
  94         if isinstance(index, slice):
  95             return Arguments(self._args[index])
  96         else:
  97             return self._args[index]
  98
  99     def __iter__(self):
 100         """Iterate over the (type, name) pairs."""
 101         return iter(self._args)
 102
 103     def __len__(self):
 104         """Number of arguments."""
 105         return len(self._args)
 106
 107     def __str__(self):
 108         """String suitable for declaring function arguments."""
 109         if len(self._args) == 0:
 110             return "void"
 111         else:
 112             return ", ".join([ " ".join([t, n]) for t,n in self._args ])
 113
 114     def __repr__(self):
 115         """Evaluable string representation for this object."""
 116         return "Arguments(\"%s\")" % str(self)
 117
 118     def names(self):
 119         """List of argument names."""
 120         return [ name for _, name in self._args ]
 121
 122     def types(self):
 123         """List of argument types."""
 124         return [ type_ for type_, _ in self._args ]
 125
 126     def casted(self):
 127         """List of argument names casted to their type."""
 128         return ["(%s)%s" % (type_, name) for type_, name in self._args]
 129
 130     def transform(self, *trans):
 131         """Return a new Arguments instance with transformed types.
 132
 133         The types in the resulting Arguments instance are transformed according
 134         to tracetool.transform.transform_type.
 135         """
 136         res = []
 137         for type_, name in self._args:
 138             res.append((tracetool.transform.transform_type(type_, *trans),
 139                         name))
 140         return Arguments(res)
 141
 142
 143 class Event(object):
 144     """Event description.
 145
 146     Attributes
 147     ----------
 148     name : str
 149         The event name.
 150     fmt : str
 151         The event format string.
 152     properties : set(str)
 153         Properties of the event.
 154     args : Arguments
 155         The event arguments.
 156
 157     """
 158
 159     _CRE = re.compile("((?P<props>[\w\s]+)\s+)?"
 160                       "(?P<name>\w+)"
 161                       "\((?P<args>[^)]*)\)"
 162                       "\s*"
 163                       "(?:(?:(?P<fmt_trans>\".+),)?\s*(?P<fmt>\".+))?"
 164                       "\s*")
 165
 166     _VALID_PROPS = set(["disable", "tcg", "tcg-trans", "tcg-exec", "vcpu"])
 167
 168     def __init__(self, name, props, fmt, args, orig=None,
 169                  event_trans=None, event_exec=None):
 170         """
 171         Parameters
 172         ----------
 173         name : string
 174             Event name.
 175         props : list of str
 176             Property names.
 177         fmt : str, list of str
 178             Event printing format string(s).
 179         args : Arguments
 180             Event arguments.
 181         orig : Event or None
 182             Original Event before transformation/generation.
 183         event_trans : Event or None
 184             Generated translation-time event ("tcg" property).
 185         event_exec : Event or None
 186             Generated execution-time event ("tcg" property).
 187
 188         """
 189         self.name = name
 190         self.properties = props
 191         self.fmt = fmt
 192         self.args = args
 193         self.event_trans = event_trans
 194         self.event_exec = event_exec
 195
 196         if len(args) > 10:
 197             raise ValueError("Event '%s' has more than maximum permitted "
 198                              "argument count" % name)
 199
 200         if orig is None:
 201             self.original = weakref.ref(self)
 202         else:
 203             self.original = orig
 204
 205         unknown_props = set(self.properties) - self._VALID_PROPS
 206         if len(unknown_props) > 0:
 207             raise ValueError("Unknown properties: %s"
 208                              % ", ".join(unknown_props))
 209         assert isinstance(self.fmt, str) or len(self.fmt) == 2
 210
 211     def copy(self):
 212         """Create a new copy."""
 213         return Event(self.name, list(self.properties), self.fmt,
 214                      self.args.copy(), self, self.event_trans, self.event_exec)
 215
 216     @staticmethod
 217     def build(line_str):
 218         """Build an Event instance from a string.
 219
 220         Parameters
 221         ----------
 222         line_str : str
 223             Line describing the event.
 224         """
 225         m = Event._CRE.match(line_str)
 226         assert m is not None
 227         groups = m.groupdict('')
 228
 229         name = groups["name"]
 230         props = groups["props"].split()
 231         fmt = groups["fmt"]
 232         fmt_trans = groups["fmt_trans"]
 233         if len(fmt_trans) > 0:
 234             fmt = [fmt_trans, fmt]
 235         args = Arguments.build(groups["args"])
 236
 237         if "tcg-trans" in props:
 238             raise ValueError("Invalid property 'tcg-trans'")
 239         if "tcg-exec" in props:
 240             raise ValueError("Invalid property 'tcg-exec'")
 241         if "tcg" not in props and not isinstance(fmt, str):
 242             raise ValueError("Only events with 'tcg' property can have two format strings")
 243         if "tcg" in props and isinstance(fmt, str):
 244             raise ValueError("Events with 'tcg' property must have two format strings")
 245
 246         event = Event(name, props, fmt, args)
 247
 248         # add implicit arguments when using the 'vcpu' property
 249         import tracetool.vcpu
 250         event = tracetool.vcpu.transform_event(event)
 251
 252         return event
 253
 254     def __repr__(self):
 255         """Evaluable string representation for this object."""
 256         if isinstance(self.fmt, str):
 257             fmt = self.fmt
 258         else:
 259             fmt = "%s, %s" % (self.fmt[0], self.fmt[1])
 260         return "Event('%s %s(%s) %s')" % (" ".join(self.properties),
 261                                           self.name,
 262                                           self.args,
 263                                           fmt)
 264
 265     _FMT = re.compile("(%[\d\.]*\w+|%.*PRI\S+)")
 266
 267     def formats(self):
 268         """List conversion specifiers in the argument print format string."""
 269         assert not isinstance(self.fmt, list)
 270         return self._FMT.findall(self.fmt)
 271
 272     QEMU_TRACE               = "trace_%(name)s"
 273     QEMU_TRACE_NOCHECK       = "_nocheck__" + QEMU_TRACE
 274     QEMU_TRACE_TCG           = QEMU_TRACE + "_tcg"
 275     QEMU_DSTATE              = "_TRACE_%(NAME)s_DSTATE"
 276     QEMU_BACKEND_DSTATE      = "TRACE_%(NAME)s_BACKEND_DSTATE"
 277     QEMU_EVENT               = "_TRACE_%(NAME)s_EVENT"
 278
 279     def api(self, fmt=None):
 280         if fmt is None:
 281             fmt = Event.QEMU_TRACE
 282         return fmt % {"name": self.name, "NAME": self.name.upper()}
 283
 284     def transform(self, *trans):
 285         """Return a new Event with transformed Arguments."""
 286         return Event(self.name,
 287                      list(self.properties),
 288                      self.fmt,
 289                      self.args.transform(*trans),
 290                      self)
 291
 292
 293 def read_events(fobj):
 294     """Generate the output for the given (format, backends) pair.
 295
 296     Parameters
 297     ----------
 298     fobj : file
 299         Event description file.
 300
 301     Returns a list of Event objects
 302     """
 303
 304     events = []
 305     for lineno, line in enumerate(fobj, 1):
 306         if not line.strip():
 307             continue
 308         if line.lstrip().startswith('#'):
 309             continue
 310
 311         try:
 312             event = Event.build(line)
 313         except ValueError as e:
 314             arg0 = 'Error on line %d: %s' % (lineno, e.args[0])
 315             e.args = (arg0,) + e.args[1:]
 316             raise
 317
 318         # transform TCG-enabled events
 319         if "tcg" not in event.properties:
 320             events.append(event)
 321         else:
 322             event_trans = event.copy()
 323             event_trans.name += "_trans"
 324             event_trans.properties += ["tcg-trans"]
 325             event_trans.fmt = event.fmt[0]
 326             # ignore TCG arguments
 327             args_trans = []
 328             for atrans, aorig in zip(
 329                     event_trans.transform(tracetool.transform.TCG_2_HOST).args,
 330                     event.args):
 331                 if atrans == aorig:
 332                     args_trans.append(atrans)
 333             event_trans.args = Arguments(args_trans)
 334
 335             event_exec = event.copy()
 336             event_exec.name += "_exec"
 337             event_exec.properties += ["tcg-exec"]
 338             event_exec.fmt = event.fmt[1]
 339             event_exec.args = event_exec.args.transform(tracetool.transform.TCG_2_HOST)
 340
 341             new_event = [event_trans, event_exec]
 342             event.event_trans, event.event_exec = new_event
 343
 344             events.extend(new_event)
 345
 346     return events
 347
 348
 349 class TracetoolError (Exception):
 350     """Exception for calls to generate."""
 351     pass
 352
 353
 354 def try_import(mod_name, attr_name=None, attr_default=None):
 355     """Try to import a module and get an attribute from it.
 356
 357     Parameters
 358     ----------
 359     mod_name : str
 360         Module name.
 361     attr_name : str, optional
 362         Name of an attribute in the module.
 363     attr_default : optional
 364         Default value if the attribute does not exist in the module.
 365
 366     Returns
 367     -------
 368     A pair indicating whether the module could be imported and the module or
 369     object or attribute value.
 370     """
 371     try:
 372         module = __import__(mod_name, globals(), locals(), ["__package__"])
 373         if attr_name is None:
 374             return True, module
 375         return True, getattr(module, str(attr_name), attr_default)
 376     except ImportError:
 377         return False, None
 378
 379
 380 def generate(events, group, format, backends,
 381              binary=None, probe_prefix=None):
 382     """Generate the output for the given (format, backends) pair.
 383
 384     Parameters
 385     ----------
 386     events : list
 387         list of Event objects to generate for
 388     group: str
 389         Name of the tracing group
 390     format : str
 391         Output format name.
 392     backends : list
 393         Output backend names.
 394     binary : str or None
 395         See tracetool.backend.dtrace.BINARY.
 396     probe_prefix : str or None
 397         See tracetool.backend.dtrace.PROBEPREFIX.
 398     """
 399     # fix strange python error (UnboundLocalError tracetool)
 400     import tracetool
 401
 402     format = str(format)
 403     if len(format) is 0:
 404         raise TracetoolError("format not set")
 405     if not tracetool.format.exists(format):
 406         raise TracetoolError("unknown format: %s" % format)
 407
 408     if len(backends) is 0:
 409         raise TracetoolError("no backends specified")
 410     for backend in backends:
 411         if not tracetool.backend.exists(backend):
 412             raise TracetoolError("unknown backend: %s" % backend)
 413     backend = tracetool.backend.Wrapper(backends, format)
 414
 415     import tracetool.backend.dtrace
 416     tracetool.backend.dtrace.BINARY = binary
 417     tracetool.backend.dtrace.PROBEPREFIX = probe_prefix
 418
 419     tracetool.format.generate(events, format, backend, group)