src/eric7/DebugClients/Python/coverage/debug.py

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eric7
changeset 9209
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parent 9099
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9208:3fc8dfeb6ebe 9209:b99e7fd55fd3
1 # Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
2 # For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt
3
4 """Control of and utilities for debugging."""
5
6 import contextlib
7 import functools
8 import inspect
9 import io
10 import itertools
11 import os
12 import pprint
13 import reprlib
14 import sys
15 import _thread
16
17 from coverage.misc import isolate_module
18
19 os = isolate_module(os)
20
21
22 # When debugging, it can be helpful to force some options, especially when
23 # debugging the configuration mechanisms you usually use to control debugging!
24 # This is a list of forced debugging options.
25 FORCED_DEBUG = []
26 FORCED_DEBUG_FILE = None
27
28
29 class DebugControl:
30 """Control and output for debugging."""
31
32 show_repr_attr = False # For SimpleReprMixin
33
34 def __init__(self, options, output):
35 """Configure the options and output file for debugging."""
36 self.options = list(options) + FORCED_DEBUG
37 self.suppress_callers = False
38
39 filters = []
40 if self.should('pid'):
41 filters.append(add_pid_and_tid)
42 self.output = DebugOutputFile.get_one(
43 output,
44 show_process=self.should('process'),
45 filters=filters,
46 )
47 self.raw_output = self.output.outfile
48
49 def __repr__(self):
50 return f"<DebugControl options={self.options!r} raw_output={self.raw_output!r}>"
51
52 def should(self, option):
53 """Decide whether to output debug information in category `option`."""
54 if option == "callers" and self.suppress_callers:
55 return False
56 return (option in self.options)
57
58 @contextlib.contextmanager
59 def without_callers(self):
60 """A context manager to prevent call stacks from being logged."""
61 old = self.suppress_callers
62 self.suppress_callers = True
63 try:
64 yield
65 finally:
66 self.suppress_callers = old
67
68 def write(self, msg):
69 """Write a line of debug output.
70
71 `msg` is the line to write. A newline will be appended.
72
73 """
74 self.output.write(msg+"\n")
75 if self.should('self'):
76 caller_self = inspect.stack()[1][0].f_locals.get('self')
77 if caller_self is not None:
78 self.output.write(f"self: {caller_self!r}\n")
79 if self.should('callers'):
80 dump_stack_frames(out=self.output, skip=1)
81 self.output.flush()
82
83
84 class DebugControlString(DebugControl):
85 """A `DebugControl` that writes to a StringIO, for testing."""
86 def __init__(self, options):
87 super().__init__(options, io.StringIO())
88
89 def get_output(self):
90 """Get the output text from the `DebugControl`."""
91 return self.raw_output.getvalue()
92
93
94 class NoDebugging:
95 """A replacement for DebugControl that will never try to do anything."""
96 def should(self, option): # pylint: disable=unused-argument
97 """Should we write debug messages? Never."""
98 return False
99
100
101 def info_header(label):
102 """Make a nice header string."""
103 return "--{:-<60s}".format(" "+label+" ")
104
105
106 def info_formatter(info):
107 """Produce a sequence of formatted lines from info.
108
109 `info` is a sequence of pairs (label, data). The produced lines are
110 nicely formatted, ready to print.
111
112 """
113 info = list(info)
114 if not info:
115 return
116 label_len = 30
117 assert all(len(l) < label_len for l, _ in info)
118 for label, data in info:
119 if data == []:
120 data = "-none-"
121 if isinstance(data, tuple) and len(repr(tuple(data))) < 30:
122 # Convert to tuple to scrub namedtuples.
123 yield "%*s: %r" % (label_len, label, tuple(data))
124 elif isinstance(data, (list, set, tuple)):
125 prefix = "%*s:" % (label_len, label)
126 for e in data:
127 yield "%*s %s" % (label_len+1, prefix, e)
128 prefix = ""
129 else:
130 yield "%*s: %s" % (label_len, label, data)
131
132
133 def write_formatted_info(write, header, info):
134 """Write a sequence of (label,data) pairs nicely.
135
136 `write` is a function write(str) that accepts each line of output.
137 `header` is a string to start the section. `info` is a sequence of
138 (label, data) pairs, where label is a str, and data can be a single
139 value, or a list/set/tuple.
140
141 """
142 write(info_header(header))
143 for line in info_formatter(info):
144 write(f" {line}")
145
146
147 def short_stack(limit=None, skip=0):
148 """Return a string summarizing the call stack.
149
150 The string is multi-line, with one line per stack frame. Each line shows
151 the function name, the file name, and the line number:
152
153 ...
154 start_import_stop : /Users/ned/coverage/trunk/tests/coveragetest.py @95
155 import_local_file : /Users/ned/coverage/trunk/tests/coveragetest.py @81
156 import_local_file : /Users/ned/coverage/trunk/coverage/backward.py @159
157 ...
158
159 `limit` is the number of frames to include, defaulting to all of them.
160
161 `skip` is the number of frames to skip, so that debugging functions can
162 call this and not be included in the result.
163
164 """
165 stack = inspect.stack()[limit:skip:-1]
166 return "\n".join("%30s : %s:%d" % (t[3], t[1], t[2]) for t in stack)
167
168
169 def dump_stack_frames(limit=None, out=None, skip=0):
170 """Print a summary of the stack to stdout, or someplace else."""
171 out = out or sys.stdout
172 out.write(short_stack(limit=limit, skip=skip+1))
173 out.write("\n")
174
175
176 def clipped_repr(text, numchars=50):
177 """`repr(text)`, but limited to `numchars`."""
178 r = reprlib.Repr()
179 r.maxstring = numchars
180 return r.repr(text)
181
182
183 def short_id(id64):
184 """Given a 64-bit id, make a shorter 16-bit one."""
185 id16 = 0
186 for offset in range(0, 64, 16):
187 id16 ^= id64 >> offset
188 return id16 & 0xFFFF
189
190
191 def add_pid_and_tid(text):
192 """A filter to add pid and tid to debug messages."""
193 # Thread ids are useful, but too long. Make a shorter one.
194 tid = f"{short_id(_thread.get_ident()):04x}"
195 text = f"{os.getpid():5d}.{tid}: {text}"
196 return text
197
198
199 class SimpleReprMixin:
200 """A mixin implementing a simple __repr__."""
201 simple_repr_ignore = ['simple_repr_ignore', '$coverage.object_id']
202
203 def __repr__(self):
204 show_attrs = (
205 (k, v) for k, v in self.__dict__.items()
206 if getattr(v, "show_repr_attr", True)
207 and not callable(v)
208 and k not in self.simple_repr_ignore
209 )
210 return "<{klass} @0x{id:x} {attrs}>".format(
211 klass=self.__class__.__name__,
212 id=id(self),
213 attrs=" ".join(f"{k}={v!r}" for k, v in show_attrs),
214 )
215
216
217 def simplify(v): # pragma: debugging
218 """Turn things which are nearly dict/list/etc into dict/list/etc."""
219 if isinstance(v, dict):
220 return {k:simplify(vv) for k, vv in v.items()}
221 elif isinstance(v, (list, tuple)):
222 return type(v)(simplify(vv) for vv in v)
223 elif hasattr(v, "__dict__"):
224 return simplify({'.'+k: v for k, v in v.__dict__.items()})
225 else:
226 return v
227
228
229 def pp(v): # pragma: debugging
230 """Debug helper to pretty-print data, including SimpleNamespace objects."""
231 # Might not be needed in 3.9+
232 pprint.pprint(simplify(v))
233
234
235 def filter_text(text, filters):
236 """Run `text` through a series of filters.
237
238 `filters` is a list of functions. Each takes a string and returns a
239 string. Each is run in turn.
240
241 Returns: the final string that results after all of the filters have
242 run.
243
244 """
245 clean_text = text.rstrip()
246 ending = text[len(clean_text):]
247 text = clean_text
248 for fn in filters:
249 lines = []
250 for line in text.splitlines():
251 lines.extend(fn(line).splitlines())
252 text = "\n".join(lines)
253 return text + ending
254
255
256 class CwdTracker: # pragma: debugging
257 """A class to add cwd info to debug messages."""
258 def __init__(self):
259 self.cwd = None
260
261 def filter(self, text):
262 """Add a cwd message for each new cwd."""
263 cwd = os.getcwd()
264 if cwd != self.cwd:
265 text = f"cwd is now {cwd!r}\n" + text
266 self.cwd = cwd
267 return text
268
269
270 class DebugOutputFile: # pragma: debugging
271 """A file-like object that includes pid and cwd information."""
272 def __init__(self, outfile, show_process, filters):
273 self.outfile = outfile
274 self.show_process = show_process
275 self.filters = list(filters)
276
277 if self.show_process:
278 self.filters.insert(0, CwdTracker().filter)
279 self.write(f"New process: executable: {sys.executable!r}\n")
280 self.write("New process: cmd: {!r}\n".format(getattr(sys, 'argv', None)))
281 if hasattr(os, 'getppid'):
282 self.write(f"New process: pid: {os.getpid()!r}, parent pid: {os.getppid()!r}\n")
283
284 SYS_MOD_NAME = '$coverage.debug.DebugOutputFile.the_one'
285
286 @classmethod
287 def get_one(cls, fileobj=None, show_process=True, filters=(), interim=False):
288 """Get a DebugOutputFile.
289
290 If `fileobj` is provided, then a new DebugOutputFile is made with it.
291
292 If `fileobj` isn't provided, then a file is chosen
293 (COVERAGE_DEBUG_FILE, or stderr), and a process-wide singleton
294 DebugOutputFile is made.
295
296 `show_process` controls whether the debug file adds process-level
297 information, and filters is a list of other message filters to apply.
298
299 `filters` are the text filters to apply to the stream to annotate with
300 pids, etc.
301
302 If `interim` is true, then a future `get_one` can replace this one.
303
304 """
305 if fileobj is not None:
306 # Make DebugOutputFile around the fileobj passed.
307 return cls(fileobj, show_process, filters)
308
309 # Because of the way igor.py deletes and re-imports modules,
310 # this class can be defined more than once. But we really want
311 # a process-wide singleton. So stash it in sys.modules instead of
312 # on a class attribute. Yes, this is aggressively gross.
313 the_one, is_interim = sys.modules.get(cls.SYS_MOD_NAME, (None, True))
314 if the_one is None or is_interim:
315 if fileobj is None:
316 debug_file_name = os.environ.get("COVERAGE_DEBUG_FILE", FORCED_DEBUG_FILE)
317 if debug_file_name in ("stdout", "stderr"):
318 fileobj = getattr(sys, debug_file_name)
319 elif debug_file_name:
320 fileobj = open(debug_file_name, "a")
321 else:
322 fileobj = sys.stderr
323 the_one = cls(fileobj, show_process, filters)
324 sys.modules[cls.SYS_MOD_NAME] = (the_one, interim)
325 return the_one
326
327 def write(self, text):
328 """Just like file.write, but filter through all our filters."""
329 self.outfile.write(filter_text(text, self.filters))
330 self.outfile.flush()
331
332 def flush(self):
333 """Flush our file."""
334 self.outfile.flush()
335
336
337 def log(msg, stack=False): # pragma: debugging
338 """Write a log message as forcefully as possible."""
339 out = DebugOutputFile.get_one(interim=True)
340 out.write(msg+"\n")
341 if stack:
342 dump_stack_frames(out=out, skip=1)
343
344
345 def decorate_methods(decorator, butnot=(), private=False): # pragma: debugging
346 """A class decorator to apply a decorator to methods."""
347 def _decorator(cls):
348 for name, meth in inspect.getmembers(cls, inspect.isroutine):
349 if name not in cls.__dict__:
350 continue
351 if name != "__init__":
352 if not private and name.startswith("_"):
353 continue
354 if name in butnot:
355 continue
356 setattr(cls, name, decorator(meth))
357 return cls
358 return _decorator
359
360
361 def break_in_pudb(func): # pragma: debugging
362 """A function decorator to stop in the debugger for each call."""
363 @functools.wraps(func)
364 def _wrapper(*args, **kwargs):
365 import pudb
366 sys.stdout = sys.__stdout__
367 pudb.set_trace()
368 return func(*args, **kwargs)
369 return _wrapper
370
371
372 OBJ_IDS = itertools.count()
373 CALLS = itertools.count()
374 OBJ_ID_ATTR = "$coverage.object_id"
375
376 def show_calls(show_args=True, show_stack=False, show_return=False): # pragma: debugging
377 """A method decorator to debug-log each call to the function."""
378 def _decorator(func):
379 @functools.wraps(func)
380 def _wrapper(self, *args, **kwargs):
381 oid = getattr(self, OBJ_ID_ATTR, None)
382 if oid is None:
383 oid = f"{os.getpid():08d} {next(OBJ_IDS):04d}"
384 setattr(self, OBJ_ID_ATTR, oid)
385 extra = ""
386 if show_args:
387 eargs = ", ".join(map(repr, args))
388 ekwargs = ", ".join("{}={!r}".format(*item) for item in kwargs.items())
389 extra += "("
390 extra += eargs
391 if eargs and ekwargs:
392 extra += ", "
393 extra += ekwargs
394 extra += ")"
395 if show_stack:
396 extra += " @ "
397 extra += "; ".join(_clean_stack_line(l) for l in short_stack().splitlines())
398 callid = next(CALLS)
399 msg = f"{oid} {callid:04d} {func.__name__}{extra}\n"
400 DebugOutputFile.get_one(interim=True).write(msg)
401 ret = func(self, *args, **kwargs)
402 if show_return:
403 msg = f"{oid} {callid:04d} {func.__name__} return {ret!r}\n"
404 DebugOutputFile.get_one(interim=True).write(msg)
405 return ret
406 return _wrapper
407 return _decorator
408
409
410 def _clean_stack_line(s): # pragma: debugging
411 """Simplify some paths in a stack trace, for compactness."""
412 s = s.strip()
413 s = s.replace(os.path.dirname(__file__) + '/', '')
414 s = s.replace(os.path.dirname(os.__file__) + '/', '')
415 s = s.replace(sys.prefix + '/', '')
416 return s

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