scripts/tracetool/__init__.py

   1 # -*- coding: utf-8 -*-
   2
   3 """
   4 Machinery for generating tracing-related intermediate files.
   5 """
   6
   7 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
   8 __copyright__  = "Copyright 2012-2017, Lluís Vilanova <vilanova@ac.upc.edu>"
   9 __license__    = "GPL version 2 or (at your option) any later version"
  10
  11 __maintainer__ = "Stefan Hajnoczi"
  12 __email__      = "stefanha@redhat.com"
  13
  14
  15 import re
  16 import sys
  17 import weakref
  18
  19 import tracetool.format
  20 import tracetool.backend
  21 import tracetool.transform
  22
  23
  24 def error_write(*lines):
  25     """Write a set of error lines."""
  26     sys.stderr.writelines("\n".join(lines) + "\n")
  27
  28 def error(*lines):
  29     """Write a set of error lines and exit."""
  30     error_write(*lines)
  31     sys.exit(1)
  32
  33
  34 out_lineno = 1
  35 out_filename = '<none>'
  36 out_fobj = sys.stdout
  37
  38 def out_open(filename):
  39     global out_filename, out_fobj
  40     out_filename = filename
  41     out_fobj = open(filename, 'wt')
  42
  43 def out(*lines, **kwargs):
  44     """Write a set of output lines.
  45
  46     You can use kwargs as a shorthand for mapping variables when formatting all
  47     the strings in lines.
  48
  49     The 'out_lineno' kwarg is automatically added to reflect the current output
  50     file line number. The 'out_next_lineno' kwarg is also automatically added
  51     with the next output line number. The 'out_filename' kwarg is automatically
  52     added with the output filename.
  53     """
  54     global out_lineno
  55     output = []
  56     for l in lines:
  57         kwargs['out_lineno'] = out_lineno
  58         kwargs['out_next_lineno'] = out_lineno + 1
  59         kwargs['out_filename'] = out_filename
  60         output.append(l % kwargs)
  61         out_lineno += 1
  62
  63     out_fobj.writelines("\n".join(output) + "\n")
  64
  65 # We only want to allow standard C types or fixed sized
  66 # integer types. We don't want QEMU specific types
  67 # as we can't assume trace backends can resolve all the
  68 # typedefs
  69 ALLOWED_TYPES = [
  70     "int",
  71     "long",
  72     "short",
  73     "char",
  74     "bool",
  75     "unsigned",
  76     "signed",
  77     "int8_t",
  78     "uint8_t",
  79     "int16_t",
  80     "uint16_t",
  81     "int32_t",
  82     "uint32_t",
  83     "int64_t",
  84     "uint64_t",
  85     "void",
  86     "size_t",
  87     "ssize_t",
  88     "uintptr_t",
  89     "ptrdiff_t",
  90 ]
  91
  92 def validate_type(name):
  93     bits = name.split(" ")
  94     for bit in bits:
  95         bit = re.sub("\*", "", bit)
  96         if bit == "":
  97             continue
  98         if bit == "const":
  99             continue
 100         if bit not in ALLOWED_TYPES:
 101             raise ValueError("Argument type '%s' is not allowed. "
 102                              "Only standard C types and fixed size integer "
 103                              "types should be used. struct, union, and "
 104                              "other complex pointer types should be "
 105                              "declared as 'void *'" % name)
 106
 107 class Arguments:
 108     """Event arguments description."""
 109
 110     def __init__(self, args):
 111         """
 112         Parameters
 113         ----------
 114         args :
 115             List of (type, name) tuples or Arguments objects.
 116         """
 117         self._args = []
 118         for arg in args:
 119             if isinstance(arg, Arguments):
 120                 self._args.extend(arg._args)
 121             else:
 122                 self._args.append(arg)
 123
 124     def copy(self):
 125         """Create a new copy."""
 126         return Arguments(list(self._args))
 127
 128     @staticmethod
 129     def build(arg_str):
 130         """Build and Arguments instance from an argument string.
 131
 132         Parameters
 133         ----------
 134         arg_str : str
 135             String describing the event arguments.
 136         """
 137         res = []
 138         for arg in arg_str.split(","):
 139             arg = arg.strip()
 140             if not arg:
 141                 raise ValueError("Empty argument (did you forget to use 'void'?)")
 142             if arg == 'void':
 143                 continue
 144
 145             if '*' in arg:
 146                 arg_type, identifier = arg.rsplit('*', 1)
 147                 arg_type += '*'
 148                 identifier = identifier.strip()
 149             else:
 150                 arg_type, identifier = arg.rsplit(None, 1)
 151
 152             validate_type(arg_type)
 153             res.append((arg_type, identifier))
 154         return Arguments(res)
 155
 156     def __getitem__(self, index):
 157         if isinstance(index, slice):
 158             return Arguments(self._args[index])
 159         else:
 160             return self._args[index]
 161
 162     def __iter__(self):
 163         """Iterate over the (type, name) pairs."""
 164         return iter(self._args)
 165
 166     def __len__(self):
 167         """Number of arguments."""
 168         return len(self._args)
 169
 170     def __str__(self):
 171         """String suitable for declaring function arguments."""
 172         if len(self._args) == 0:
 173             return "void"
 174         else:
 175             return ", ".join([ " ".join([t, n]) for t,n in self._args ])
 176
 177     def __repr__(self):
 178         """Evaluable string representation for this object."""
 179         return "Arguments(\"%s\")" % str(self)
 180
 181     def names(self):
 182         """List of argument names."""
 183         return [ name for _, name in self._args ]
 184
 185     def types(self):
 186         """List of argument types."""
 187         return [ type_ for type_, _ in self._args ]
 188
 189     def casted(self):
 190         """List of argument names casted to their type."""
 191         return ["(%s)%s" % (type_, name) for type_, name in self._args]
 192
 193     def transform(self, *trans):
 194         """Return a new Arguments instance with transformed types.
 195
 196         The types in the resulting Arguments instance are transformed according
 197         to tracetool.transform.transform_type.
 198         """
 199         res = []
 200         for type_, name in self._args:
 201             res.append((tracetool.transform.transform_type(type_, *trans),
 202                         name))
 203         return Arguments(res)
 204
 205
 206 class Event(object):
 207     """Event description.
 208
 209     Attributes
 210     ----------
 211     name : str
 212         The event name.
 213     fmt : str
 214         The event format string.
 215     properties : set(str)
 216         Properties of the event.
 217     args : Arguments
 218         The event arguments.
 219     lineno : int
 220         The line number in the input file.
 221     filename : str
 222         The path to the input file.
 223
 224     """
 225
 226     _CRE = re.compile("((?P<props>[\w\s]+)\s+)?"
 227                       "(?P<name>\w+)"
 228                       "\((?P<args>[^)]*)\)"
 229                       "\s*"
 230                       "(?:(?:(?P<fmt_trans>\".+),)?\s*(?P<fmt>\".+))?"
 231                       "\s*")
 232
 233     _VALID_PROPS = set(["disable", "vcpu"])
 234
 235     def __init__(self, name, props, fmt, args, lineno, filename, orig=None,
 236                  event_trans=None, event_exec=None):
 237         """
 238         Parameters
 239         ----------
 240         name : string
 241             Event name.
 242         props : list of str
 243             Property names.
 244         fmt : str, list of str
 245             Event printing format string(s).
 246         args : Arguments
 247             Event arguments.
 248         lineno : int
 249             The line number in the input file.
 250         filename : str
 251             The path to the input file.
 252         orig : Event or None
 253             Original Event before transformation/generation.
 254         event_trans : Event or None
 255             Generated translation-time event ("tcg" property).
 256         event_exec : Event or None
 257             Generated execution-time event ("tcg" property).
 258
 259         """
 260         self.name = name
 261         self.properties = props
 262         self.fmt = fmt
 263         self.args = args
 264         self.lineno = int(lineno)
 265         self.filename = str(filename)
 266         self.event_trans = event_trans
 267         self.event_exec = event_exec
 268
 269         if len(args) > 10:
 270             raise ValueError("Event '%s' has more than maximum permitted "
 271                              "argument count" % name)
 272
 273         if orig is None:
 274             self.original = weakref.ref(self)
 275         else:
 276             self.original = orig
 277
 278         unknown_props = set(self.properties) - self._VALID_PROPS
 279         if len(unknown_props) > 0:
 280             raise ValueError("Unknown properties: %s"
 281                              % ", ".join(unknown_props))
 282         assert isinstance(self.fmt, str) or len(self.fmt) == 2
 283
 284     def copy(self):
 285         """Create a new copy."""
 286         return Event(self.name, list(self.properties), self.fmt,
 287                      self.args.copy(), self.lineno, self.filename,
 288                      self, self.event_trans, self.event_exec)
 289
 290     @staticmethod
 291     def build(line_str, lineno, filename):
 292         """Build an Event instance from a string.
 293
 294         Parameters
 295         ----------
 296         line_str : str
 297             Line describing the event.
 298         lineno : int
 299             Line number in input file.
 300         filename : str
 301             Path to input file.
 302         """
 303         m = Event._CRE.match(line_str)
 304         assert m is not None
 305         groups = m.groupdict('')
 306
 307         name = groups["name"]
 308         props = groups["props"].split()
 309         fmt = groups["fmt"]
 310         fmt_trans = groups["fmt_trans"]
 311         if fmt.find("%m") != -1 or fmt_trans.find("%m") != -1:
 312             raise ValueError("Event format '%m' is forbidden, pass the error "
 313                              "as an explicit trace argument")
 314         if fmt.endswith(r'\n"'):
 315             raise ValueError("Event format must not end with a newline "
 316                              "character")
 317
 318         if len(fmt_trans) > 0:
 319             fmt = [fmt_trans, fmt]
 320         args = Arguments.build(groups["args"])
 321
 322         event = Event(name, props, fmt, args, lineno, filename)
 323
 324         # add implicit arguments when using the 'vcpu' property
 325         import tracetool.vcpu
 326         event = tracetool.vcpu.transform_event(event)
 327
 328         return event
 329
 330     def __repr__(self):
 331         """Evaluable string representation for this object."""
 332         if isinstance(self.fmt, str):
 333             fmt = self.fmt
 334         else:
 335             fmt = "%s, %s" % (self.fmt[0], self.fmt[1])
 336         return "Event('%s %s(%s) %s')" % (" ".join(self.properties),
 337                                           self.name,
 338                                           self.args,
 339                                           fmt)
 340     # Star matching on PRI is dangerous as one might have multiple
 341     # arguments with that format, hence the non-greedy version of it.
 342     _FMT = re.compile("(%[\d\.]*\w+|%.*?PRI\S+)")
 343
 344     def formats(self):
 345         """List conversion specifiers in the argument print format string."""
 346         assert not isinstance(self.fmt, list)
 347         return self._FMT.findall(self.fmt)
 348
 349     QEMU_TRACE               = "trace_%(name)s"
 350     QEMU_TRACE_NOCHECK       = "_nocheck__" + QEMU_TRACE
 351     QEMU_TRACE_TCG           = QEMU_TRACE + "_tcg"
 352     QEMU_DSTATE              = "_TRACE_%(NAME)s_DSTATE"
 353     QEMU_BACKEND_DSTATE      = "TRACE_%(NAME)s_BACKEND_DSTATE"
 354     QEMU_EVENT               = "_TRACE_%(NAME)s_EVENT"
 355
 356     def api(self, fmt=None):
 357         if fmt is None:
 358             fmt = Event.QEMU_TRACE
 359         return fmt % {"name": self.name, "NAME": self.name.upper()}
 360
 361     def transform(self, *trans):
 362         """Return a new Event with transformed Arguments."""
 363         return Event(self.name,
 364                      list(self.properties),
 365                      self.fmt,
 366                      self.args.transform(*trans),
 367                      self.lineno,
 368                      self.filename,
 369                      self)
 370
 371
 372 def read_events(fobj, fname):
 373     """Generate the output for the given (format, backends) pair.
 374
 375     Parameters
 376     ----------
 377     fobj : file
 378         Event description file.
 379     fname : str
 380         Name of event file
 381
 382     Returns a list of Event objects
 383     """
 384
 385     events = []
 386     for lineno, line in enumerate(fobj, 1):
 387         if line[-1] != '\n':
 388             raise ValueError("%s does not end with a new line" % fname)
 389         if not line.strip():
 390             continue
 391         if line.lstrip().startswith('#'):
 392             continue
 393
 394         try:
 395             event = Event.build(line, lineno, fname)
 396         except ValueError as e:
 397             arg0 = 'Error at %s:%d: %s' % (fname, lineno, e.args[0])
 398             e.args = (arg0,) + e.args[1:]
 399             raise
 400
 401         events.append(event)
 402
 403     return events
 404
 405
 406 class TracetoolError (Exception):
 407     """Exception for calls to generate."""
 408     pass
 409
 410
 411 def try_import(mod_name, attr_name=None, attr_default=None):
 412     """Try to import a module and get an attribute from it.
 413
 414     Parameters
 415     ----------
 416     mod_name : str
 417         Module name.
 418     attr_name : str, optional
 419         Name of an attribute in the module.
 420     attr_default : optional
 421         Default value if the attribute does not exist in the module.
 422
 423     Returns
 424     -------
 425     A pair indicating whether the module could be imported and the module or
 426     object or attribute value.
 427     """
 428     try:
 429         module = __import__(mod_name, globals(), locals(), ["__package__"])
 430         if attr_name is None:
 431             return True, module
 432         return True, getattr(module, str(attr_name), attr_default)
 433     except ImportError:
 434         return False, None
 435
 436
 437 def generate(events, group, format, backends,
 438              binary=None, probe_prefix=None):
 439     """Generate the output for the given (format, backends) pair.
 440
 441     Parameters
 442     ----------
 443     events : list
 444         list of Event objects to generate for
 445     group: str
 446         Name of the tracing group
 447     format : str
 448         Output format name.
 449     backends : list
 450         Output backend names.
 451     binary : str or None
 452         See tracetool.backend.dtrace.BINARY.
 453     probe_prefix : str or None
 454         See tracetool.backend.dtrace.PROBEPREFIX.
 455     """
 456     # fix strange python error (UnboundLocalError tracetool)
 457     import tracetool
 458
 459     format = str(format)
 460     if len(format) == 0:
 461         raise TracetoolError("format not set")
 462     if not tracetool.format.exists(format):
 463         raise TracetoolError("unknown format: %s" % format)
 464
 465     if len(backends) == 0:
 466         raise TracetoolError("no backends specified")
 467     for backend in backends:
 468         if not tracetool.backend.exists(backend):
 469             raise TracetoolError("unknown backend: %s" % backend)
 470     backend = tracetool.backend.Wrapper(backends, format)
 471
 472     import tracetool.backend.dtrace
 473     tracetool.backend.dtrace.BINARY = binary
 474     tracetool.backend.dtrace.PROBEPREFIX = probe_prefix
 475
 476     tracetool.format.generate(events, format, backend, group)