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"])
 165
 166     def __init__(self, name, props, fmt, args, orig=None):
 167         """
 168         Parameters
 169         ----------
 170         name : string
 171             Event name.
 172         props : list of str
 173             Property names.
 174         fmt : str, list of str
 175             Event printing format (or formats).
 176         args : Arguments
 177             Event arguments.
 178         orig : Event or None
 179             Original Event before transformation.
 180
 181         """
 182         self.name = name
 183         self.properties = props
 184         self.fmt = fmt
 185         self.args = args
 186
 187         if orig is None:
 188             self.original = weakref.ref(self)
 189         else:
 190             self.original = orig
 191
 192         unknown_props = set(self.properties) - self._VALID_PROPS
 193         if len(unknown_props) > 0:
 194             raise ValueError("Unknown properties: %s"
 195                              % ", ".join(unknown_props))
 196         assert isinstance(self.fmt, str) or len(self.fmt) == 2
 197
 198     def copy(self):
 199         """Create a new copy."""
 200         return Event(self.name, list(self.properties), self.fmt,
 201                      self.args.copy(), self)
 202
 203     @staticmethod
 204     def build(line_str):
 205         """Build an Event instance from a string.
 206
 207         Parameters
 208         ----------
 209         line_str : str
 210             Line describing the event.
 211         """
 212         m = Event._CRE.match(line_str)
 213         assert m is not None
 214         groups = m.groupdict('')
 215
 216         name = groups["name"]
 217         props = groups["props"].split()
 218         fmt = groups["fmt"]
 219         fmt_trans = groups["fmt_trans"]
 220         if len(fmt_trans) > 0:
 221             fmt = [fmt_trans, fmt]
 222         args = Arguments.build(groups["args"])
 223
 224         if "tcg-trans" in props:
 225             raise ValueError("Invalid property 'tcg-trans'")
 226         if "tcg-exec" in props:
 227             raise ValueError("Invalid property 'tcg-exec'")
 228         if "tcg" not in props and not isinstance(fmt, str):
 229             raise ValueError("Only events with 'tcg' property can have two formats")
 230         if "tcg" in props and isinstance(fmt, str):
 231             raise ValueError("Events with 'tcg' property must have two formats")
 232
 233         return Event(name, props, fmt, args)
 234
 235     def __repr__(self):
 236         """Evaluable string representation for this object."""
 237         if isinstance(self.fmt, str):
 238             fmt = self.fmt
 239         else:
 240             fmt = "%s, %s" % (self.fmt[0], self.fmt[1])
 241         return "Event('%s %s(%s) %s')" % (" ".join(self.properties),
 242                                           self.name,
 243                                           self.args,
 244                                           fmt)
 245
 246     _FMT = re.compile("(%[\d\.]*\w+|%.*PRI\S+)")
 247
 248     def formats(self):
 249         """List of argument print formats."""
 250         assert not isinstance(self.fmt, list)
 251         return self._FMT.findall(self.fmt)
 252
 253     QEMU_TRACE               = "trace_%(name)s"
 254     QEMU_TRACE_TCG           = QEMU_TRACE + "_tcg"
 255
 256     def api(self, fmt=None):
 257         if fmt is None:
 258             fmt = Event.QEMU_TRACE
 259         return fmt % {"name": self.name}
 260
 261     def transform(self, *trans):
 262         """Return a new Event with transformed Arguments."""
 263         return Event(self.name,
 264                      list(self.properties),
 265                      self.fmt,
 266                      self.args.transform(*trans),
 267                      self)
 268
 269
 270 def _read_events(fobj):
 271     events = []
 272     for line in fobj:
 273         if not line.strip():
 274             continue
 275         if line.lstrip().startswith('#'):
 276             continue
 277
 278         event = Event.build(line)
 279
 280         # transform TCG-enabled events
 281         if "tcg" not in event.properties:
 282             events.append(event)
 283         else:
 284             event_trans = event.copy()
 285             event_trans.name += "_trans"
 286             event_trans.properties += ["tcg-trans"]
 287             event_trans.fmt = event.fmt[0]
 288             args_trans = []
 289             for atrans, aorig in zip(
 290                     event_trans.transform(tracetool.transform.TCG_2_HOST).args,
 291                     event.args):
 292                 if atrans == aorig:
 293                     args_trans.append(atrans)
 294             event_trans.args = Arguments(args_trans)
 295
 296             event_exec = event.copy()
 297             event_exec.name += "_exec"
 298             event_exec.properties += ["tcg-exec"]
 299             event_exec.fmt = event.fmt[1]
 300             event_exec.args = event_exec.args.transform(tracetool.transform.TCG_2_HOST)
 301
 302             new_event = [event_trans, event_exec]
 303             event.event_trans, event.event_exec = new_event
 304
 305             events.extend(new_event)
 306
 307     return events
 308
 309
 310 class TracetoolError (Exception):
 311     """Exception for calls to generate."""
 312     pass
 313
 314
 315 def try_import(mod_name, attr_name=None, attr_default=None):
 316     """Try to import a module and get an attribute from it.
 317
 318     Parameters
 319     ----------
 320     mod_name : str
 321         Module name.
 322     attr_name : str, optional
 323         Name of an attribute in the module.
 324     attr_default : optional
 325         Default value if the attribute does not exist in the module.
 326
 327     Returns
 328     -------
 329     A pair indicating whether the module could be imported and the module or
 330     object or attribute value.
 331     """
 332     try:
 333         module = __import__(mod_name, globals(), locals(), ["__package__"])
 334         if attr_name is None:
 335             return True, module
 336         return True, getattr(module, str(attr_name), attr_default)
 337     except ImportError:
 338         return False, None
 339
 340
 341 def generate(fevents, format, backends,
 342              binary=None, probe_prefix=None):
 343     """Generate the output for the given (format, backends) pair.
 344
 345     Parameters
 346     ----------
 347     fevents : file
 348         Event description file.
 349     format : str
 350         Output format name.
 351     backends : list
 352         Output backend names.
 353     binary : str or None
 354         See tracetool.backend.dtrace.BINARY.
 355     probe_prefix : str or None
 356         See tracetool.backend.dtrace.PROBEPREFIX.
 357     """
 358     # fix strange python error (UnboundLocalError tracetool)
 359     import tracetool
 360
 361     format = str(format)
 362     if len(format) is 0:
 363         raise TracetoolError("format not set")
 364     if not tracetool.format.exists(format):
 365         raise TracetoolError("unknown format: %s" % format)
 366
 367     if len(backends) is 0:
 368         raise TracetoolError("no backends specified")
 369     for backend in backends:
 370         if not tracetool.backend.exists(backend):
 371             raise TracetoolError("unknown backend: %s" % backend)
 372     backend = tracetool.backend.Wrapper(backends, format)
 373
 374     import tracetool.backend.dtrace
 375     tracetool.backend.dtrace.BINARY = binary
 376     tracetool.backend.dtrace.PROBEPREFIX = probe_prefix
 377
 378     events = _read_events(fevents)
 379
 380     tracetool.format.generate(events, format, backend)