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 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 len(args) > 10:
 195             raise ValueError("Event '%s' has more than maximum permitted "
 196                              "argument count" % name)
 197
 198         if orig is None:
 199             self.original = weakref.ref(self)
 200         else:
 201             self.original = orig
 202
 203         unknown_props = set(self.properties) - self._VALID_PROPS
 204         if len(unknown_props) > 0:
 205             raise ValueError("Unknown properties: %s"
 206                              % ", ".join(unknown_props))
 207         assert isinstance(self.fmt, str) or len(self.fmt) == 2
 208
 209     def copy(self):
 210         """Create a new copy."""
 211         return Event(self.name, list(self.properties), self.fmt,
 212                      self.args.copy(), self, self.event_trans, self.event_exec)
 213
 214     @staticmethod
 215     def build(line_str):
 216         """Build an Event instance from a string.
 217
 218         Parameters
 219         ----------
 220         line_str : str
 221             Line describing the event.
 222         """
 223         m = Event._CRE.match(line_str)
 224         assert m is not None
 225         groups = m.groupdict('')
 226
 227         name = groups["name"]
 228         props = groups["props"].split()
 229         fmt = groups["fmt"]
 230         fmt_trans = groups["fmt_trans"]
 231         if len(fmt_trans) > 0:
 232             fmt = [fmt_trans, fmt]
 233         args = Arguments.build(groups["args"])
 234
 235         if "tcg-trans" in props:
 236             raise ValueError("Invalid property 'tcg-trans'")
 237         if "tcg-exec" in props:
 238             raise ValueError("Invalid property 'tcg-exec'")
 239         if "tcg" not in props and not isinstance(fmt, str):
 240             raise ValueError("Only events with 'tcg' property can have two formats")
 241         if "tcg" in props and isinstance(fmt, str):
 242             raise ValueError("Events with 'tcg' property must have two formats")
 243
 244         event = Event(name, props, fmt, args)
 245
 246         # add implicit arguments when using the 'vcpu' property
 247         import tracetool.vcpu
 248         event = tracetool.vcpu.transform_event(event)
 249
 250         return event
 251
 252     def __repr__(self):
 253         """Evaluable string representation for this object."""
 254         if isinstance(self.fmt, str):
 255             fmt = self.fmt
 256         else:
 257             fmt = "%s, %s" % (self.fmt[0], self.fmt[1])
 258         return "Event('%s %s(%s) %s')" % (" ".join(self.properties),
 259                                           self.name,
 260                                           self.args,
 261                                           fmt)
 262
 263     _FMT = re.compile("(%[\d\.]*\w+|%.*PRI\S+)")
 264
 265     def formats(self):
 266         """List of argument print formats."""
 267         assert not isinstance(self.fmt, list)
 268         return self._FMT.findall(self.fmt)
 269
 270     QEMU_TRACE               = "trace_%(name)s"
 271     QEMU_TRACE_NOCHECK       = "_nocheck__" + QEMU_TRACE
 272     QEMU_TRACE_TCG           = QEMU_TRACE + "_tcg"
 273     QEMU_DSTATE              = "_TRACE_%(NAME)s_DSTATE"
 274     QEMU_EVENT               = "_TRACE_%(NAME)s_EVENT"
 275
 276     def api(self, fmt=None):
 277         if fmt is None:
 278             fmt = Event.QEMU_TRACE
 279         return fmt % {"name": self.name, "NAME": self.name.upper()}
 280
 281     def transform(self, *trans):
 282         """Return a new Event with transformed Arguments."""
 283         return Event(self.name,
 284                      list(self.properties),
 285                      self.fmt,
 286                      self.args.transform(*trans),
 287                      self)
 288
 289
 290 def read_events(fobj):
 291     """Generate the output for the given (format, backends) pair.
 292
 293     Parameters
 294     ----------
 295     fobj : file
 296         Event description file.
 297
 298     Returns a list of Event objects
 299     """
 300
 301     events = []
 302     for line in fobj:
 303         if not line.strip():
 304             continue
 305         if line.lstrip().startswith('#'):
 306             continue
 307
 308         event = Event.build(line)
 309
 310         # transform TCG-enabled events
 311         if "tcg" not in event.properties:
 312             events.append(event)
 313         else:
 314             event_trans = event.copy()
 315             event_trans.name += "_trans"
 316             event_trans.properties += ["tcg-trans"]
 317             event_trans.fmt = event.fmt[0]
 318             # ignore TCG arguments
 319             args_trans = []
 320             for atrans, aorig in zip(
 321                     event_trans.transform(tracetool.transform.TCG_2_HOST).args,
 322                     event.args):
 323                 if atrans == aorig:
 324                     args_trans.append(atrans)
 325             event_trans.args = Arguments(args_trans)
 326
 327             event_exec = event.copy()
 328             event_exec.name += "_exec"
 329             event_exec.properties += ["tcg-exec"]
 330             event_exec.fmt = event.fmt[1]
 331             event_exec.args = event_exec.args.transform(tracetool.transform.TCG_2_HOST)
 332
 333             new_event = [event_trans, event_exec]
 334             event.event_trans, event.event_exec = new_event
 335
 336             events.extend(new_event)
 337
 338     return events
 339
 340
 341 class TracetoolError (Exception):
 342     """Exception for calls to generate."""
 343     pass
 344
 345
 346 def try_import(mod_name, attr_name=None, attr_default=None):
 347     """Try to import a module and get an attribute from it.
 348
 349     Parameters
 350     ----------
 351     mod_name : str
 352         Module name.
 353     attr_name : str, optional
 354         Name of an attribute in the module.
 355     attr_default : optional
 356         Default value if the attribute does not exist in the module.
 357
 358     Returns
 359     -------
 360     A pair indicating whether the module could be imported and the module or
 361     object or attribute value.
 362     """
 363     try:
 364         module = __import__(mod_name, globals(), locals(), ["__package__"])
 365         if attr_name is None:
 366             return True, module
 367         return True, getattr(module, str(attr_name), attr_default)
 368     except ImportError:
 369         return False, None
 370
 371
 372 def generate(events, group, format, backends,
 373              binary=None, probe_prefix=None):
 374     """Generate the output for the given (format, backends) pair.
 375
 376     Parameters
 377     ----------
 378     events : list
 379         list of Event objects to generate for
 380     group: str
 381         Name of the tracing group
 382     format : str
 383         Output format name.
 384     backends : list
 385         Output backend names.
 386     binary : str or None
 387         See tracetool.backend.dtrace.BINARY.
 388     probe_prefix : str or None
 389         See tracetool.backend.dtrace.PROBEPREFIX.
 390     """
 391     # fix strange python error (UnboundLocalError tracetool)
 392     import tracetool
 393
 394     format = str(format)
 395     if len(format) is 0:
 396         raise TracetoolError("format not set")
 397     if not tracetool.format.exists(format):
 398         raise TracetoolError("unknown format: %s" % format)
 399
 400     if len(backends) is 0:
 401         raise TracetoolError("no backends specified")
 402     for backend in backends:
 403         if not tracetool.backend.exists(backend):
 404             raise TracetoolError("unknown backend: %s" % backend)
 405     backend = tracetool.backend.Wrapper(backends, format)
 406
 407     import tracetool.backend.dtrace
 408     tracetool.backend.dtrace.BINARY = binary
 409     tracetool.backend.dtrace.PROBEPREFIX = probe_prefix
 410
 411     tracetool.format.generate(events, format, backend, group)