xref: /openbmc/qemu/scripts/tracetool/__init__.py (revision 406d2aa2) 
1#!/usr/bin/env python
2# -*- coding: utf-8 -*-
3
4"""
5Machinery 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
16import re
17import sys
18import weakref
19
20import tracetool.format
21import tracetool.backend
22import tracetool.transform
23
24
25def error_write(*lines):
26    """Write a set of error lines."""
27    sys.stderr.writelines("\n".join(lines) + "\n")
28
29def error(*lines):
30    """Write a set of error lines and exit."""
31    error_write(*lines)
32    sys.exit(1)
33
34
35def 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
45class 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
141class 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_BACKEND_DSTATE      = "TRACE_%(NAME)s_BACKEND_DSTATE"
275    QEMU_EVENT               = "_TRACE_%(NAME)s_EVENT"
276
277    def api(self, fmt=None):
278        if fmt is None:
279            fmt = Event.QEMU_TRACE
280        return fmt % {"name": self.name, "NAME": self.name.upper()}
281
282    def transform(self, *trans):
283        """Return a new Event with transformed Arguments."""
284        return Event(self.name,
285                     list(self.properties),
286                     self.fmt,
287                     self.args.transform(*trans),
288                     self)
289
290
291def read_events(fobj):
292    """Generate the output for the given (format, backends) pair.
293
294    Parameters
295    ----------
296    fobj : file
297        Event description file.
298
299    Returns a list of Event objects
300    """
301
302    events = []
303    for line in fobj:
304        if not line.strip():
305            continue
306        if line.lstrip().startswith('#'):
307            continue
308
309        event = Event.build(line)
310
311        # transform TCG-enabled events
312        if "tcg" not in event.properties:
313            events.append(event)
314        else:
315            event_trans = event.copy()
316            event_trans.name += "_trans"
317            event_trans.properties += ["tcg-trans"]
318            event_trans.fmt = event.fmt[0]
319            # ignore TCG arguments
320            args_trans = []
321            for atrans, aorig in zip(
322                    event_trans.transform(tracetool.transform.TCG_2_HOST).args,
323                    event.args):
324                if atrans == aorig:
325                    args_trans.append(atrans)
326            event_trans.args = Arguments(args_trans)
327
328            event_exec = event.copy()
329            event_exec.name += "_exec"
330            event_exec.properties += ["tcg-exec"]
331            event_exec.fmt = event.fmt[1]
332            event_exec.args = event_exec.args.transform(tracetool.transform.TCG_2_HOST)
333
334            new_event = [event_trans, event_exec]
335            event.event_trans, event.event_exec = new_event
336
337            events.extend(new_event)
338
339    return events
340
341
342class TracetoolError (Exception):
343    """Exception for calls to generate."""
344    pass
345
346
347def try_import(mod_name, attr_name=None, attr_default=None):
348    """Try to import a module and get an attribute from it.
349
350    Parameters
351    ----------
352    mod_name : str
353        Module name.
354    attr_name : str, optional
355        Name of an attribute in the module.
356    attr_default : optional
357        Default value if the attribute does not exist in the module.
358
359    Returns
360    -------
361    A pair indicating whether the module could be imported and the module or
362    object or attribute value.
363    """
364    try:
365        module = __import__(mod_name, globals(), locals(), ["__package__"])
366        if attr_name is None:
367            return True, module
368        return True, getattr(module, str(attr_name), attr_default)
369    except ImportError:
370        return False, None
371
372
373def generate(events, group, format, backends,
374             binary=None, probe_prefix=None):
375    """Generate the output for the given (format, backends) pair.
376
377    Parameters
378    ----------
379    events : list
380        list of Event objects to generate for
381    group: str
382        Name of the tracing group
383    format : str
384        Output format name.
385    backends : list
386        Output backend names.
387    binary : str or None
388        See tracetool.backend.dtrace.BINARY.
389    probe_prefix : str or None
390        See tracetool.backend.dtrace.PROBEPREFIX.
391    """
392    # fix strange python error (UnboundLocalError tracetool)
393    import tracetool
394
395    format = str(format)
396    if len(format) is 0:
397        raise TracetoolError("format not set")
398    if not tracetool.format.exists(format):
399        raise TracetoolError("unknown format: %s" % format)
400
401    if len(backends) is 0:
402        raise TracetoolError("no backends specified")
403    for backend in backends:
404        if not tracetool.backend.exists(backend):
405            raise TracetoolError("unknown backend: %s" % backend)
406    backend = tracetool.backend.Wrapper(backends, format)
407
408    import tracetool.backend.dtrace
409    tracetool.backend.dtrace.BINARY = binary
410    tracetool.backend.dtrace.PROBEPREFIX = probe_prefix
411
412    tracetool.format.generate(events, format, backend, group)
413