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 2012-2016, 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 arg == 'void':
  79                 continue
  80
  81             if '*' in arg:
  82                 arg_type, identifier = arg.rsplit('*', 1)
  83                 arg_type += '*'
  84                 identifier = identifier.strip()
  85             else:
  86                 arg_type, identifier = arg.rsplit(None, 1)
  87
  88             res.append((arg_type, identifier))
  89         return Arguments(res)
  90
  91     def __getitem__(self, index):
  92         if isinstance(index, slice):
  93             return Arguments(self._args[index])
  94         else:
  95             return self._args[index]
  96
  97     def __iter__(self):
  98         """Iterate over the (type, name) pairs."""
  99         return iter(self._args)
 100
 101     def __len__(self):
 102         """Number of arguments."""
 103         return len(self._args)
 104
 105     def __str__(self):
 106         """String suitable for declaring function arguments."""
 107         if len(self._args) == 0:
 108             return "void"
 109         else:
 110             return ", ".join([ " ".join([t, n]) for t,n in self._args ])
 111
 112     def __repr__(self):
 113         """Evaluable string representation for this object."""
 114         return "Arguments(\"%s\")" % str(self)
 115
 116     def names(self):
 117         """List of argument names."""
 118         return [ name for _, name in self._args ]
 119
 120     def types(self):
 121         """List of argument types."""
 122         return [ type_ for type_, _ in self._args ]
 123
 124     def casted(self):
 125         """List of argument names casted to their type."""
 126         return ["(%s)%s" % (type_, name) for type_, name in self._args]
 127
 128     def transform(self, *trans):
 129         """Return a new Arguments instance with transformed types.
 130
 131         The types in the resulting Arguments instance are transformed according
 132         to tracetool.transform.transform_type.
 133         """
 134         res = []
 135         for type_, name in self._args:
 136             res.append((tracetool.transform.transform_type(type_, *trans),
 137                         name))
 138         return Arguments(res)
 139
 140
 141 class Event(object):
 142     """Event description.
 143
 144     Attributes
 145     ----------
 146     name : str
 147         The event name.
 148     fmt : str
 149         The event format string.
 150     properties : set(str)
 151         Properties of the event.
 152     args : Arguments
 153         The event arguments.
 154
 155     """
 156
 157     _CRE = re.compile("((?P<props>[\w\s]+)\s+)?"
 158                       "(?P<name>\w+)"
 159                       "\((?P<args>[^)]*)\)"
 160                       "\s*"
 161                       "(?:(?:(?P<fmt_trans>\".+),)?\s*(?P<fmt>\".+))?"
 162                       "\s*")
 163
 164     _VALID_PROPS = set(["disable", "tcg", "tcg-trans", "tcg-exec", "vcpu"])
 165
 166     def __init__(self, name, props, fmt, args, orig=None,
 167                  event_trans=None, event_exec=None):
 168         """
 169         Parameters
 170         ----------
 171         name : string
 172             Event name.
 173         props : list of str
 174             Property names.
 175         fmt : str, list of str
 176             Event printing format (or formats).
 177         args : Arguments
 178             Event arguments.
 179         orig : Event or None
 180             Original Event before transformation/generation.
 181         event_trans : Event or None
 182             Generated translation-time event ("tcg" property).
 183         event_exec : Event or None
 184             Generated execution-time event ("tcg" property).
 185
 186         """
 187         self.name = name
 188         self.properties = props
 189         self.fmt = fmt
 190         self.args = args
 191         self.event_trans = event_trans
 192         self.event_exec = event_exec
 193
 194         if orig is None:
 195             self.original = weakref.ref(self)
 196         else:
 197             self.original = orig
 198
 199         unknown_props = set(self.properties) - self._VALID_PROPS
 200         if len(unknown_props) > 0:
 201             raise ValueError("Unknown properties: %s"
 202                              % ", ".join(unknown_props))
 203         assert isinstance(self.fmt, str) or len(self.fmt) == 2
 204
 205     def copy(self):
 206         """Create a new copy."""
 207         return Event(self.name, list(self.properties), self.fmt,
 208                      self.args.copy(), self, self.event_trans, self.event_exec)
 209
 210     @staticmethod
 211     def build(line_str):
 212         """Build an Event instance from a string.
 213
 214         Parameters
 215         ----------
 216         line_str : str
 217             Line describing the event.
 218         """
 219         m = Event._CRE.match(line_str)
 220         assert m is not None
 221         groups = m.groupdict('')
 222
 223         name = groups["name"]
 224         props = groups["props"].split()
 225         fmt = groups["fmt"]
 226         fmt_trans = groups["fmt_trans"]
 227         if len(fmt_trans) > 0:
 228             fmt = [fmt_trans, fmt]
 229         args = Arguments.build(groups["args"])
 230
 231         if "tcg-trans" in props:
 232             raise ValueError("Invalid property 'tcg-trans'")
 233         if "tcg-exec" in props:
 234             raise ValueError("Invalid property 'tcg-exec'")
 235         if "tcg" not in props and not isinstance(fmt, str):
 236             raise ValueError("Only events with 'tcg' property can have two formats")
 237         if "tcg" in props and isinstance(fmt, str):
 238             raise ValueError("Events with 'tcg' property must have two formats")
 239
 240         event = Event(name, props, fmt, args)
 241
 242         # add implicit arguments when using the 'vcpu' property
 243         import tracetool.vcpu
 244         event = tracetool.vcpu.transform_event(event)
 245
 246         return event
 247
 248     def __repr__(self):
 249         """Evaluable string representation for this object."""
 250         if isinstance(self.fmt, str):
 251             fmt = self.fmt
 252         else:
 253             fmt = "%s, %s" % (self.fmt[0], self.fmt[1])
 254         return "Event('%s %s(%s) %s')" % (" ".join(self.properties),
 255                                           self.name,
 256                                           self.args,
 257                                           fmt)
 258
 259     _FMT = re.compile("(%[\d\.]*\w+|%.*PRI\S+)")
 260
 261     def formats(self):
 262         """List of argument print formats."""
 263         assert not isinstance(self.fmt, list)
 264         return self._FMT.findall(self.fmt)
 265
 266     QEMU_TRACE               = "trace_%(name)s"
 267     QEMU_TRACE_TCG           = QEMU_TRACE + "_tcg"
 268     QEMU_DSTATE              = "_TRACE_%(NAME)s_DSTATE"
 269     QEMU_EVENT               = "_TRACE_%(NAME)s_EVENT"
 270
 271     def api(self, fmt=None):
 272         if fmt is None:
 273             fmt = Event.QEMU_TRACE
 274         return fmt % {"name": self.name, "NAME": self.name.upper()}
 275
 276     def transform(self, *trans):
 277         """Return a new Event with transformed Arguments."""
 278         return Event(self.name,
 279                      list(self.properties),
 280                      self.fmt,
 281                      self.args.transform(*trans),
 282                      self)
 283
 284
 285 def read_events(fobj):
 286     """Generate the output for the given (format, backends) pair.
 287
 288     Parameters
 289     ----------
 290     fobj : file
 291         Event description file.
 292
 293     Returns a list of Event objects
 294     """
 295
 296     events = []
 297     for line in fobj:
 298         if not line.strip():
 299             continue
 300         if line.lstrip().startswith('#'):
 301             continue
 302
 303         event = Event.build(line)
 304
 305         # transform TCG-enabled events
 306         if "tcg" not in event.properties:
 307             events.append(event)
 308         else:
 309             event_trans = event.copy()
 310             event_trans.name += "_trans"
 311             event_trans.properties += ["tcg-trans"]
 312             event_trans.fmt = event.fmt[0]
 313             # ignore TCG arguments
 314             args_trans = []
 315             for atrans, aorig in zip(
 316                     event_trans.transform(tracetool.transform.TCG_2_HOST).args,
 317                     event.args):
 318                 if atrans == aorig:
 319                     args_trans.append(atrans)
 320             event_trans.args = Arguments(args_trans)
 321
 322             event_exec = event.copy()
 323             event_exec.name += "_exec"
 324             event_exec.properties += ["tcg-exec"]
 325             event_exec.fmt = event.fmt[1]
 326             event_exec.args = event_exec.args.transform(tracetool.transform.TCG_2_HOST)
 327
 328             new_event = [event_trans, event_exec]
 329             event.event_trans, event.event_exec = new_event
 330
 331             events.extend(new_event)
 332
 333     return events
 334
 335
 336 class TracetoolError (Exception):
 337     """Exception for calls to generate."""
 338     pass
 339
 340
 341 def try_import(mod_name, attr_name=None, attr_default=None):
 342     """Try to import a module and get an attribute from it.
 343
 344     Parameters
 345     ----------
 346     mod_name : str
 347         Module name.
 348     attr_name : str, optional
 349         Name of an attribute in the module.
 350     attr_default : optional
 351         Default value if the attribute does not exist in the module.
 352
 353     Returns
 354     -------
 355     A pair indicating whether the module could be imported and the module or
 356     object or attribute value.
 357     """
 358     try:
 359         module = __import__(mod_name, globals(), locals(), ["__package__"])
 360         if attr_name is None:
 361             return True, module
 362         return True, getattr(module, str(attr_name), attr_default)
 363     except ImportError:
 364         return False, None
 365
 366
 367 def generate(events, group, format, backends,
 368              binary=None, probe_prefix=None):
 369     """Generate the output for the given (format, backends) pair.
 370
 371     Parameters
 372     ----------
 373     events : list
 374         list of Event objects to generate for
 375     group: str
 376         Name of the tracing group
 377     format : str
 378         Output format name.
 379     backends : list
 380         Output backend names.
 381     binary : str or None
 382         See tracetool.backend.dtrace.BINARY.
 383     probe_prefix : str or None
 384         See tracetool.backend.dtrace.PROBEPREFIX.
 385     """
 386     # fix strange python error (UnboundLocalError tracetool)
 387     import tracetool
 388
 389     format = str(format)
 390     if len(format) is 0:
 391         raise TracetoolError("format not set")
 392     if not tracetool.format.exists(format):
 393         raise TracetoolError("unknown format: %s" % format)
 394
 395     if len(backends) is 0:
 396         raise TracetoolError("no backends specified")
 397     for backend in backends:
 398         if not tracetool.backend.exists(backend):
 399             raise TracetoolError("unknown backend: %s" % backend)
 400     backend = tracetool.backend.Wrapper(backends, format)
 401
 402     import tracetool.backend.dtrace
 403     tracetool.backend.dtrace.BINARY = binary
 404     tracetool.backend.dtrace.PROBEPREFIX = probe_prefix
 405
 406     tracetool.format.generate(events, format, backend, group)