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 # We only want to allow standard C types or fixed sized
  45 # integer types. We don't want QEMU specific types
  46 # as we can't assume trace backends can resolve all the
  47 # typedefs
  48 ALLOWED_TYPES = [
  49     "int",
  50     "long",
  51     "short",
  52     "char",
  53     "bool",
  54     "unsigned",
  55     "signed",
  56     "float",
  57     "double",
  58     "int8_t",
  59     "uint8_t",
  60     "int16_t",
  61     "uint16_t",
  62     "int32_t",
  63     "uint32_t",
  64     "int64_t",
  65     "uint64_t",
  66     "void",
  67     "size_t",
  68     "ssize_t",
  69     "uintptr_t",
  70     "ptrdiff_t",
  71     # Magic substitution is done by tracetool
  72     "TCGv",
  73 ]
  74
  75 def validate_type(name):
  76     bits = name.split(" ")
  77     for bit in bits:
  78         bit = re.sub("\*", "", bit)
  79         if bit == "":
  80             continue
  81         if bit == "const":
  82             continue
  83         if bit not in ALLOWED_TYPES:
  84             raise ValueError("Argument type '%s' is not in whitelist. "
  85                              "Only standard C types and fixed size integer "
  86                              "types should be used. struct, union, and "
  87                              "other complex pointer types should be "
  88                              "declared as 'void *'" % name)
  89
  90 class Arguments:
  91     """Event arguments description."""
  92
  93     def __init__(self, args):
  94         """
  95         Parameters
  96         ----------
  97         args :
  98             List of (type, name) tuples or Arguments objects.
  99         """
 100         self._args = []
 101         for arg in args:
 102             if isinstance(arg, Arguments):
 103                 self._args.extend(arg._args)
 104             else:
 105                 self._args.append(arg)
 106
 107     def copy(self):
 108         """Create a new copy."""
 109         return Arguments(list(self._args))
 110
 111     @staticmethod
 112     def build(arg_str):
 113         """Build and Arguments instance from an argument string.
 114
 115         Parameters
 116         ----------
 117         arg_str : str
 118             String describing the event arguments.
 119         """
 120         res = []
 121         for arg in arg_str.split(","):
 122             arg = arg.strip()
 123             if not arg:
 124                 raise ValueError("Empty argument (did you forget to use 'void'?)")
 125             if arg == 'void':
 126                 continue
 127
 128             if '*' in arg:
 129                 arg_type, identifier = arg.rsplit('*', 1)
 130                 arg_type += '*'
 131                 identifier = identifier.strip()
 132             else:
 133                 arg_type, identifier = arg.rsplit(None, 1)
 134
 135             validate_type(arg_type)
 136             res.append((arg_type, identifier))
 137         return Arguments(res)
 138
 139     def __getitem__(self, index):
 140         if isinstance(index, slice):
 141             return Arguments(self._args[index])
 142         else:
 143             return self._args[index]
 144
 145     def __iter__(self):
 146         """Iterate over the (type, name) pairs."""
 147         return iter(self._args)
 148
 149     def __len__(self):
 150         """Number of arguments."""
 151         return len(self._args)
 152
 153     def __str__(self):
 154         """String suitable for declaring function arguments."""
 155         if len(self._args) == 0:
 156             return "void"
 157         else:
 158             return ", ".join([ " ".join([t, n]) for t,n in self._args ])
 159
 160     def __repr__(self):
 161         """Evaluable string representation for this object."""
 162         return "Arguments(\"%s\")" % str(self)
 163
 164     def names(self):
 165         """List of argument names."""
 166         return [ name for _, name in self._args ]
 167
 168     def types(self):
 169         """List of argument types."""
 170         return [ type_ for type_, _ in self._args ]
 171
 172     def casted(self):
 173         """List of argument names casted to their type."""
 174         return ["(%s)%s" % (type_, name) for type_, name in self._args]
 175
 176     def transform(self, *trans):
 177         """Return a new Arguments instance with transformed types.
 178
 179         The types in the resulting Arguments instance are transformed according
 180         to tracetool.transform.transform_type.
 181         """
 182         res = []
 183         for type_, name in self._args:
 184             res.append((tracetool.transform.transform_type(type_, *trans),
 185                         name))
 186         return Arguments(res)
 187
 188
 189 class Event(object):
 190     """Event description.
 191
 192     Attributes
 193     ----------
 194     name : str
 195         The event name.
 196     fmt : str
 197         The event format string.
 198     properties : set(str)
 199         Properties of the event.
 200     args : Arguments
 201         The event arguments.
 202
 203     """
 204
 205     _CRE = re.compile("((?P<props>[\w\s]+)\s+)?"
 206                       "(?P<name>\w+)"
 207                       "\((?P<args>[^)]*)\)"
 208                       "\s*"
 209                       "(?:(?:(?P<fmt_trans>\".+),)?\s*(?P<fmt>\".+))?"
 210                       "\s*")
 211
 212     _VALID_PROPS = set(["disable", "tcg", "tcg-trans", "tcg-exec", "vcpu"])
 213
 214     def __init__(self, name, props, fmt, args, orig=None,
 215                  event_trans=None, event_exec=None):
 216         """
 217         Parameters
 218         ----------
 219         name : string
 220             Event name.
 221         props : list of str
 222             Property names.
 223         fmt : str, list of str
 224             Event printing format string(s).
 225         args : Arguments
 226             Event arguments.
 227         orig : Event or None
 228             Original Event before transformation/generation.
 229         event_trans : Event or None
 230             Generated translation-time event ("tcg" property).
 231         event_exec : Event or None
 232             Generated execution-time event ("tcg" property).
 233
 234         """
 235         self.name = name
 236         self.properties = props
 237         self.fmt = fmt
 238         self.args = args
 239         self.event_trans = event_trans
 240         self.event_exec = event_exec
 241
 242         if len(args) > 10:
 243             raise ValueError("Event '%s' has more than maximum permitted "
 244                              "argument count" % name)
 245
 246         if orig is None:
 247             self.original = weakref.ref(self)
 248         else:
 249             self.original = orig
 250
 251         unknown_props = set(self.properties) - self._VALID_PROPS
 252         if len(unknown_props) > 0:
 253             raise ValueError("Unknown properties: %s"
 254                              % ", ".join(unknown_props))
 255         assert isinstance(self.fmt, str) or len(self.fmt) == 2
 256
 257     def copy(self):
 258         """Create a new copy."""
 259         return Event(self.name, list(self.properties), self.fmt,
 260                      self.args.copy(), self, self.event_trans, self.event_exec)
 261
 262     @staticmethod
 263     def build(line_str):
 264         """Build an Event instance from a string.
 265
 266         Parameters
 267         ----------
 268         line_str : str
 269             Line describing the event.
 270         """
 271         m = Event._CRE.match(line_str)
 272         assert m is not None
 273         groups = m.groupdict('')
 274
 275         name = groups["name"]
 276         props = groups["props"].split()
 277         fmt = groups["fmt"]
 278         fmt_trans = groups["fmt_trans"]
 279         if len(fmt_trans) > 0:
 280             fmt = [fmt_trans, fmt]
 281         args = Arguments.build(groups["args"])
 282
 283         if "tcg-trans" in props:
 284             raise ValueError("Invalid property 'tcg-trans'")
 285         if "tcg-exec" in props:
 286             raise ValueError("Invalid property 'tcg-exec'")
 287         if "tcg" not in props and not isinstance(fmt, str):
 288             raise ValueError("Only events with 'tcg' property can have two format strings")
 289         if "tcg" in props and isinstance(fmt, str):
 290             raise ValueError("Events with 'tcg' property must have two format strings")
 291
 292         event = Event(name, props, fmt, args)
 293
 294         # add implicit arguments when using the 'vcpu' property
 295         import tracetool.vcpu
 296         event = tracetool.vcpu.transform_event(event)
 297
 298         return event
 299
 300     def __repr__(self):
 301         """Evaluable string representation for this object."""
 302         if isinstance(self.fmt, str):
 303             fmt = self.fmt
 304         else:
 305             fmt = "%s, %s" % (self.fmt[0], self.fmt[1])
 306         return "Event('%s %s(%s) %s')" % (" ".join(self.properties),
 307                                           self.name,
 308                                           self.args,
 309                                           fmt)
 310     # Star matching on PRI is dangerous as one might have multiple
 311     # arguments with that format, hence the non-greedy version of it.
 312     _FMT = re.compile("(%[\d\.]*\w+|%.*?PRI\S+)")
 313
 314     def formats(self):
 315         """List conversion specifiers in the argument print format string."""
 316         assert not isinstance(self.fmt, list)
 317         return self._FMT.findall(self.fmt)
 318
 319     QEMU_TRACE               = "trace_%(name)s"
 320     QEMU_TRACE_NOCHECK       = "_nocheck__" + QEMU_TRACE
 321     QEMU_TRACE_TCG           = QEMU_TRACE + "_tcg"
 322     QEMU_DSTATE              = "_TRACE_%(NAME)s_DSTATE"
 323     QEMU_BACKEND_DSTATE      = "TRACE_%(NAME)s_BACKEND_DSTATE"
 324     QEMU_EVENT               = "_TRACE_%(NAME)s_EVENT"
 325
 326     def api(self, fmt=None):
 327         if fmt is None:
 328             fmt = Event.QEMU_TRACE
 329         return fmt % {"name": self.name, "NAME": self.name.upper()}
 330
 331     def transform(self, *trans):
 332         """Return a new Event with transformed Arguments."""
 333         return Event(self.name,
 334                      list(self.properties),
 335                      self.fmt,
 336                      self.args.transform(*trans),
 337                      self)
 338
 339
 340 def read_events(fobj, fname):
 341     """Generate the output for the given (format, backends) pair.
 342
 343     Parameters
 344     ----------
 345     fobj : file
 346         Event description file.
 347     fname : str
 348         Name of event file
 349
 350     Returns a list of Event objects
 351     """
 352
 353     events = []
 354     for lineno, line in enumerate(fobj, 1):
 355         if not line.strip():
 356             continue
 357         if line.lstrip().startswith('#'):
 358             continue
 359
 360         try:
 361             event = Event.build(line)
 362         except ValueError as e:
 363             arg0 = 'Error at %s:%d: %s' % (fname, lineno, e.args[0])
 364             e.args = (arg0,) + e.args[1:]
 365             raise
 366
 367         # transform TCG-enabled events
 368         if "tcg" not in event.properties:
 369             events.append(event)
 370         else:
 371             event_trans = event.copy()
 372             event_trans.name += "_trans"
 373             event_trans.properties += ["tcg-trans"]
 374             event_trans.fmt = event.fmt[0]
 375             # ignore TCG arguments
 376             args_trans = []
 377             for atrans, aorig in zip(
 378                     event_trans.transform(tracetool.transform.TCG_2_HOST).args,
 379                     event.args):
 380                 if atrans == aorig:
 381                     args_trans.append(atrans)
 382             event_trans.args = Arguments(args_trans)
 383
 384             event_exec = event.copy()
 385             event_exec.name += "_exec"
 386             event_exec.properties += ["tcg-exec"]
 387             event_exec.fmt = event.fmt[1]
 388             event_exec.args = event_exec.args.transform(tracetool.transform.TCG_2_HOST)
 389
 390             new_event = [event_trans, event_exec]
 391             event.event_trans, event.event_exec = new_event
 392
 393             events.extend(new_event)
 394
 395     return events
 396
 397
 398 class TracetoolError (Exception):
 399     """Exception for calls to generate."""
 400     pass
 401
 402
 403 def try_import(mod_name, attr_name=None, attr_default=None):
 404     """Try to import a module and get an attribute from it.
 405
 406     Parameters
 407     ----------
 408     mod_name : str
 409         Module name.
 410     attr_name : str, optional
 411         Name of an attribute in the module.
 412     attr_default : optional
 413         Default value if the attribute does not exist in the module.
 414
 415     Returns
 416     -------
 417     A pair indicating whether the module could be imported and the module or
 418     object or attribute value.
 419     """
 420     try:
 421         module = __import__(mod_name, globals(), locals(), ["__package__"])
 422         if attr_name is None:
 423             return True, module
 424         return True, getattr(module, str(attr_name), attr_default)
 425     except ImportError:
 426         return False, None
 427
 428
 429 def generate(events, group, format, backends,
 430              binary=None, probe_prefix=None):
 431     """Generate the output for the given (format, backends) pair.
 432
 433     Parameters
 434     ----------
 435     events : list
 436         list of Event objects to generate for
 437     group: str
 438         Name of the tracing group
 439     format : str
 440         Output format name.
 441     backends : list
 442         Output backend names.
 443     binary : str or None
 444         See tracetool.backend.dtrace.BINARY.
 445     probe_prefix : str or None
 446         See tracetool.backend.dtrace.PROBEPREFIX.
 447     """
 448     # fix strange python error (UnboundLocalError tracetool)
 449     import tracetool
 450
 451     format = str(format)
 452     if len(format) is 0:
 453         raise TracetoolError("format not set")
 454     if not tracetool.format.exists(format):
 455         raise TracetoolError("unknown format: %s" % format)
 456
 457     if len(backends) is 0:
 458         raise TracetoolError("no backends specified")
 459     for backend in backends:
 460         if not tracetool.backend.exists(backend):
 461             raise TracetoolError("unknown backend: %s" % backend)
 462     backend = tracetool.backend.Wrapper(backends, format)
 463
 464     import tracetool.backend.dtrace
 465     tracetool.backend.dtrace.BINARY = binary
 466     tracetool.backend.dtrace.PROBEPREFIX = probe_prefix
 467
 468     tracetool.format.generate(events, format, backend, group)