xref: /openbmc/qemu/scripts/tracetool/__init__.py (revision bc9beb47) 
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 2012-2016, 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
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"])
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
270def _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
310class TracetoolError (Exception):
311    """Exception for calls to generate."""
312    pass
313
314
315def 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
341def 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)
381