source: python/trunk/Lib/bdb.py@ 403

Last change on this file since 403 was 391, checked in by dmik, 11 years ago

python: Merge vendor 2.7.6 to trunk.

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Line 
1"""Debugger basics"""
2
3import fnmatch
4import sys
5import os
6import types
7
8__all__ = ["BdbQuit","Bdb","Breakpoint"]
9
10class BdbQuit(Exception):
11 """Exception to give up completely"""
12
13
14class Bdb:
15
16 """Generic Python debugger base class.
17
18 This class takes care of details of the trace facility;
19 a derived class should implement user interaction.
20 The standard debugger class (pdb.Pdb) is an example.
21 """
22
23 def __init__(self, skip=None):
24 self.skip = set(skip) if skip else None
25 self.breaks = {}
26 self.fncache = {}
27 self.frame_returning = None
28
29 def canonic(self, filename):
30 if filename == "<" + filename[1:-1] + ">":
31 return filename
32 canonic = self.fncache.get(filename)
33 if not canonic:
34 canonic = os.path.abspath(filename)
35 canonic = os.path.normcase(canonic)
36 self.fncache[filename] = canonic
37 return canonic
38
39 def reset(self):
40 import linecache
41 linecache.checkcache()
42 self.botframe = None
43 self._set_stopinfo(None, None)
44
45 def trace_dispatch(self, frame, event, arg):
46 if self.quitting:
47 return # None
48 if event == 'line':
49 return self.dispatch_line(frame)
50 if event == 'call':
51 return self.dispatch_call(frame, arg)
52 if event == 'return':
53 return self.dispatch_return(frame, arg)
54 if event == 'exception':
55 return self.dispatch_exception(frame, arg)
56 if event == 'c_call':
57 return self.trace_dispatch
58 if event == 'c_exception':
59 return self.trace_dispatch
60 if event == 'c_return':
61 return self.trace_dispatch
62 print 'bdb.Bdb.dispatch: unknown debugging event:', repr(event)
63 return self.trace_dispatch
64
65 def dispatch_line(self, frame):
66 if self.stop_here(frame) or self.break_here(frame):
67 self.user_line(frame)
68 if self.quitting: raise BdbQuit
69 return self.trace_dispatch
70
71 def dispatch_call(self, frame, arg):
72 # XXX 'arg' is no longer used
73 if self.botframe is None:
74 # First call of dispatch since reset()
75 self.botframe = frame.f_back # (CT) Note that this may also be None!
76 return self.trace_dispatch
77 if not (self.stop_here(frame) or self.break_anywhere(frame)):
78 # No need to trace this function
79 return # None
80 self.user_call(frame, arg)
81 if self.quitting: raise BdbQuit
82 return self.trace_dispatch
83
84 def dispatch_return(self, frame, arg):
85 if self.stop_here(frame) or frame == self.returnframe:
86 try:
87 self.frame_returning = frame
88 self.user_return(frame, arg)
89 finally:
90 self.frame_returning = None
91 if self.quitting: raise BdbQuit
92 return self.trace_dispatch
93
94 def dispatch_exception(self, frame, arg):
95 if self.stop_here(frame):
96 self.user_exception(frame, arg)
97 if self.quitting: raise BdbQuit
98 return self.trace_dispatch
99
100 # Normally derived classes don't override the following
101 # methods, but they may if they want to redefine the
102 # definition of stopping and breakpoints.
103
104 def is_skipped_module(self, module_name):
105 for pattern in self.skip:
106 if fnmatch.fnmatch(module_name, pattern):
107 return True
108 return False
109
110 def stop_here(self, frame):
111 # (CT) stopframe may now also be None, see dispatch_call.
112 # (CT) the former test for None is therefore removed from here.
113 if self.skip and \
114 self.is_skipped_module(frame.f_globals.get('__name__')):
115 return False
116 if frame is self.stopframe:
117 if self.stoplineno == -1:
118 return False
119 return frame.f_lineno >= self.stoplineno
120 while frame is not None and frame is not self.stopframe:
121 if frame is self.botframe:
122 return True
123 frame = frame.f_back
124 return False
125
126 def break_here(self, frame):
127 filename = self.canonic(frame.f_code.co_filename)
128 if not filename in self.breaks:
129 return False
130 lineno = frame.f_lineno
131 if not lineno in self.breaks[filename]:
132 # The line itself has no breakpoint, but maybe the line is the
133 # first line of a function with breakpoint set by function name.
134 lineno = frame.f_code.co_firstlineno
135 if not lineno in self.breaks[filename]:
136 return False
137
138 # flag says ok to delete temp. bp
139 (bp, flag) = effective(filename, lineno, frame)
140 if bp:
141 self.currentbp = bp.number
142 if (flag and bp.temporary):
143 self.do_clear(str(bp.number))
144 return True
145 else:
146 return False
147
148 def do_clear(self, arg):
149 raise NotImplementedError, "subclass of bdb must implement do_clear()"
150
151 def break_anywhere(self, frame):
152 return self.canonic(frame.f_code.co_filename) in self.breaks
153
154 # Derived classes should override the user_* methods
155 # to gain control.
156
157 def user_call(self, frame, argument_list):
158 """This method is called when there is the remote possibility
159 that we ever need to stop in this function."""
160 pass
161
162 def user_line(self, frame):
163 """This method is called when we stop or break at this line."""
164 pass
165
166 def user_return(self, frame, return_value):
167 """This method is called when a return trap is set here."""
168 pass
169
170 def user_exception(self, frame, exc_info):
171 exc_type, exc_value, exc_traceback = exc_info
172 """This method is called if an exception occurs,
173 but only if we are to stop at or just below this level."""
174 pass
175
176 def _set_stopinfo(self, stopframe, returnframe, stoplineno=0):
177 self.stopframe = stopframe
178 self.returnframe = returnframe
179 self.quitting = 0
180 # stoplineno >= 0 means: stop at line >= the stoplineno
181 # stoplineno -1 means: don't stop at all
182 self.stoplineno = stoplineno
183
184 # Derived classes and clients can call the following methods
185 # to affect the stepping state.
186
187 def set_until(self, frame): #the name "until" is borrowed from gdb
188 """Stop when the line with the line no greater than the current one is
189 reached or when returning from current frame"""
190 self._set_stopinfo(frame, frame, frame.f_lineno+1)
191
192 def set_step(self):
193 """Stop after one line of code."""
194 # Issue #13183: pdb skips frames after hitting a breakpoint and running
195 # step commands.
196 # Restore the trace function in the caller (that may not have been set
197 # for performance reasons) when returning from the current frame.
198 if self.frame_returning:
199 caller_frame = self.frame_returning.f_back
200 if caller_frame and not caller_frame.f_trace:
201 caller_frame.f_trace = self.trace_dispatch
202 self._set_stopinfo(None, None)
203
204 def set_next(self, frame):
205 """Stop on the next line in or below the given frame."""
206 self._set_stopinfo(frame, None)
207
208 def set_return(self, frame):
209 """Stop when returning from the given frame."""
210 self._set_stopinfo(frame.f_back, frame)
211
212 def set_trace(self, frame=None):
213 """Start debugging from `frame`.
214
215 If frame is not specified, debugging starts from caller's frame.
216 """
217 if frame is None:
218 frame = sys._getframe().f_back
219 self.reset()
220 while frame:
221 frame.f_trace = self.trace_dispatch
222 self.botframe = frame
223 frame = frame.f_back
224 self.set_step()
225 sys.settrace(self.trace_dispatch)
226
227 def set_continue(self):
228 # Don't stop except at breakpoints or when finished
229 self._set_stopinfo(self.botframe, None, -1)
230 if not self.breaks:
231 # no breakpoints; run without debugger overhead
232 sys.settrace(None)
233 frame = sys._getframe().f_back
234 while frame and frame is not self.botframe:
235 del frame.f_trace
236 frame = frame.f_back
237
238 def set_quit(self):
239 self.stopframe = self.botframe
240 self.returnframe = None
241 self.quitting = 1
242 sys.settrace(None)
243
244 # Derived classes and clients can call the following methods
245 # to manipulate breakpoints. These methods return an
246 # error message is something went wrong, None if all is well.
247 # Set_break prints out the breakpoint line and file:lineno.
248 # Call self.get_*break*() to see the breakpoints or better
249 # for bp in Breakpoint.bpbynumber: if bp: bp.bpprint().
250
251 def set_break(self, filename, lineno, temporary=0, cond = None,
252 funcname=None):
253 filename = self.canonic(filename)
254 import linecache # Import as late as possible
255 line = linecache.getline(filename, lineno)
256 if not line:
257 return 'Line %s:%d does not exist' % (filename,
258 lineno)
259 if not filename in self.breaks:
260 self.breaks[filename] = []
261 list = self.breaks[filename]
262 if not lineno in list:
263 list.append(lineno)
264 bp = Breakpoint(filename, lineno, temporary, cond, funcname)
265
266 def _prune_breaks(self, filename, lineno):
267 if (filename, lineno) not in Breakpoint.bplist:
268 self.breaks[filename].remove(lineno)
269 if not self.breaks[filename]:
270 del self.breaks[filename]
271
272 def clear_break(self, filename, lineno):
273 filename = self.canonic(filename)
274 if not filename in self.breaks:
275 return 'There are no breakpoints in %s' % filename
276 if lineno not in self.breaks[filename]:
277 return 'There is no breakpoint at %s:%d' % (filename,
278 lineno)
279 # If there's only one bp in the list for that file,line
280 # pair, then remove the breaks entry
281 for bp in Breakpoint.bplist[filename, lineno][:]:
282 bp.deleteMe()
283 self._prune_breaks(filename, lineno)
284
285 def clear_bpbynumber(self, arg):
286 try:
287 number = int(arg)
288 except:
289 return 'Non-numeric breakpoint number (%s)' % arg
290 try:
291 bp = Breakpoint.bpbynumber[number]
292 except IndexError:
293 return 'Breakpoint number (%d) out of range' % number
294 if not bp:
295 return 'Breakpoint (%d) already deleted' % number
296 bp.deleteMe()
297 self._prune_breaks(bp.file, bp.line)
298
299 def clear_all_file_breaks(self, filename):
300 filename = self.canonic(filename)
301 if not filename in self.breaks:
302 return 'There are no breakpoints in %s' % filename
303 for line in self.breaks[filename]:
304 blist = Breakpoint.bplist[filename, line]
305 for bp in blist:
306 bp.deleteMe()
307 del self.breaks[filename]
308
309 def clear_all_breaks(self):
310 if not self.breaks:
311 return 'There are no breakpoints'
312 for bp in Breakpoint.bpbynumber:
313 if bp:
314 bp.deleteMe()
315 self.breaks = {}
316
317 def get_break(self, filename, lineno):
318 filename = self.canonic(filename)
319 return filename in self.breaks and \
320 lineno in self.breaks[filename]
321
322 def get_breaks(self, filename, lineno):
323 filename = self.canonic(filename)
324 return filename in self.breaks and \
325 lineno in self.breaks[filename] and \
326 Breakpoint.bplist[filename, lineno] or []
327
328 def get_file_breaks(self, filename):
329 filename = self.canonic(filename)
330 if filename in self.breaks:
331 return self.breaks[filename]
332 else:
333 return []
334
335 def get_all_breaks(self):
336 return self.breaks
337
338 # Derived classes and clients can call the following method
339 # to get a data structure representing a stack trace.
340
341 def get_stack(self, f, t):
342 stack = []
343 if t and t.tb_frame is f:
344 t = t.tb_next
345 while f is not None:
346 stack.append((f, f.f_lineno))
347 if f is self.botframe:
348 break
349 f = f.f_back
350 stack.reverse()
351 i = max(0, len(stack) - 1)
352 while t is not None:
353 stack.append((t.tb_frame, t.tb_lineno))
354 t = t.tb_next
355 if f is None:
356 i = max(0, len(stack) - 1)
357 return stack, i
358
359 #
360
361 def format_stack_entry(self, frame_lineno, lprefix=': '):
362 import linecache, repr
363 frame, lineno = frame_lineno
364 filename = self.canonic(frame.f_code.co_filename)
365 s = '%s(%r)' % (filename, lineno)
366 if frame.f_code.co_name:
367 s = s + frame.f_code.co_name
368 else:
369 s = s + "<lambda>"
370 if '__args__' in frame.f_locals:
371 args = frame.f_locals['__args__']
372 else:
373 args = None
374 if args:
375 s = s + repr.repr(args)
376 else:
377 s = s + '()'
378 if '__return__' in frame.f_locals:
379 rv = frame.f_locals['__return__']
380 s = s + '->'
381 s = s + repr.repr(rv)
382 line = linecache.getline(filename, lineno, frame.f_globals)
383 if line: s = s + lprefix + line.strip()
384 return s
385
386 # The following two methods can be called by clients to use
387 # a debugger to debug a statement, given as a string.
388
389 def run(self, cmd, globals=None, locals=None):
390 if globals is None:
391 import __main__
392 globals = __main__.__dict__
393 if locals is None:
394 locals = globals
395 self.reset()
396 sys.settrace(self.trace_dispatch)
397 if not isinstance(cmd, types.CodeType):
398 cmd = cmd+'\n'
399 try:
400 exec cmd in globals, locals
401 except BdbQuit:
402 pass
403 finally:
404 self.quitting = 1
405 sys.settrace(None)
406
407 def runeval(self, expr, globals=None, locals=None):
408 if globals is None:
409 import __main__
410 globals = __main__.__dict__
411 if locals is None:
412 locals = globals
413 self.reset()
414 sys.settrace(self.trace_dispatch)
415 if not isinstance(expr, types.CodeType):
416 expr = expr+'\n'
417 try:
418 return eval(expr, globals, locals)
419 except BdbQuit:
420 pass
421 finally:
422 self.quitting = 1
423 sys.settrace(None)
424
425 def runctx(self, cmd, globals, locals):
426 # B/W compatibility
427 self.run(cmd, globals, locals)
428
429 # This method is more useful to debug a single function call.
430
431 def runcall(self, func, *args, **kwds):
432 self.reset()
433 sys.settrace(self.trace_dispatch)
434 res = None
435 try:
436 res = func(*args, **kwds)
437 except BdbQuit:
438 pass
439 finally:
440 self.quitting = 1
441 sys.settrace(None)
442 return res
443
444
445def set_trace():
446 Bdb().set_trace()
447
448
449class Breakpoint:
450
451 """Breakpoint class
452
453 Implements temporary breakpoints, ignore counts, disabling and
454 (re)-enabling, and conditionals.
455
456 Breakpoints are indexed by number through bpbynumber and by
457 the file,line tuple using bplist. The former points to a
458 single instance of class Breakpoint. The latter points to a
459 list of such instances since there may be more than one
460 breakpoint per line.
461
462 """
463
464 # XXX Keeping state in the class is a mistake -- this means
465 # you cannot have more than one active Bdb instance.
466
467 next = 1 # Next bp to be assigned
468 bplist = {} # indexed by (file, lineno) tuple
469 bpbynumber = [None] # Each entry is None or an instance of Bpt
470 # index 0 is unused, except for marking an
471 # effective break .... see effective()
472
473 def __init__(self, file, line, temporary=0, cond=None, funcname=None):
474 self.funcname = funcname
475 # Needed if funcname is not None.
476 self.func_first_executable_line = None
477 self.file = file # This better be in canonical form!
478 self.line = line
479 self.temporary = temporary
480 self.cond = cond
481 self.enabled = 1
482 self.ignore = 0
483 self.hits = 0
484 self.number = Breakpoint.next
485 Breakpoint.next = Breakpoint.next + 1
486 # Build the two lists
487 self.bpbynumber.append(self)
488 if (file, line) in self.bplist:
489 self.bplist[file, line].append(self)
490 else:
491 self.bplist[file, line] = [self]
492
493
494 def deleteMe(self):
495 index = (self.file, self.line)
496 self.bpbynumber[self.number] = None # No longer in list
497 self.bplist[index].remove(self)
498 if not self.bplist[index]:
499 # No more bp for this f:l combo
500 del self.bplist[index]
501
502 def enable(self):
503 self.enabled = 1
504
505 def disable(self):
506 self.enabled = 0
507
508 def bpprint(self, out=None):
509 if out is None:
510 out = sys.stdout
511 if self.temporary:
512 disp = 'del '
513 else:
514 disp = 'keep '
515 if self.enabled:
516 disp = disp + 'yes '
517 else:
518 disp = disp + 'no '
519 print >>out, '%-4dbreakpoint %s at %s:%d' % (self.number, disp,
520 self.file, self.line)
521 if self.cond:
522 print >>out, '\tstop only if %s' % (self.cond,)
523 if self.ignore:
524 print >>out, '\tignore next %d hits' % (self.ignore)
525 if (self.hits):
526 if (self.hits > 1): ss = 's'
527 else: ss = ''
528 print >>out, ('\tbreakpoint already hit %d time%s' %
529 (self.hits, ss))
530
531# -----------end of Breakpoint class----------
532
533def checkfuncname(b, frame):
534 """Check whether we should break here because of `b.funcname`."""
535 if not b.funcname:
536 # Breakpoint was set via line number.
537 if b.line != frame.f_lineno:
538 # Breakpoint was set at a line with a def statement and the function
539 # defined is called: don't break.
540 return False
541 return True
542
543 # Breakpoint set via function name.
544
545 if frame.f_code.co_name != b.funcname:
546 # It's not a function call, but rather execution of def statement.
547 return False
548
549 # We are in the right frame.
550 if not b.func_first_executable_line:
551 # The function is entered for the 1st time.
552 b.func_first_executable_line = frame.f_lineno
553
554 if b.func_first_executable_line != frame.f_lineno:
555 # But we are not at the first line number: don't break.
556 return False
557 return True
558
559# Determines if there is an effective (active) breakpoint at this
560# line of code. Returns breakpoint number or 0 if none
561def effective(file, line, frame):
562 """Determine which breakpoint for this file:line is to be acted upon.
563
564 Called only if we know there is a bpt at this
565 location. Returns breakpoint that was triggered and a flag
566 that indicates if it is ok to delete a temporary bp.
567
568 """
569 possibles = Breakpoint.bplist[file,line]
570 for i in range(0, len(possibles)):
571 b = possibles[i]
572 if b.enabled == 0:
573 continue
574 if not checkfuncname(b, frame):
575 continue
576 # Count every hit when bp is enabled
577 b.hits = b.hits + 1
578 if not b.cond:
579 # If unconditional, and ignoring,
580 # go on to next, else break
581 if b.ignore > 0:
582 b.ignore = b.ignore -1
583 continue
584 else:
585 # breakpoint and marker that's ok
586 # to delete if temporary
587 return (b,1)
588 else:
589 # Conditional bp.
590 # Ignore count applies only to those bpt hits where the
591 # condition evaluates to true.
592 try:
593 val = eval(b.cond, frame.f_globals,
594 frame.f_locals)
595 if val:
596 if b.ignore > 0:
597 b.ignore = b.ignore -1
598 # continue
599 else:
600 return (b,1)
601 # else:
602 # continue
603 except:
604 # if eval fails, most conservative
605 # thing is to stop on breakpoint
606 # regardless of ignore count.
607 # Don't delete temporary,
608 # as another hint to user.
609 return (b,0)
610 return (None, None)
611
612# -------------------- testing --------------------
613
614class Tdb(Bdb):
615 def user_call(self, frame, args):
616 name = frame.f_code.co_name
617 if not name: name = '???'
618 print '+++ call', name, args
619 def user_line(self, frame):
620 import linecache
621 name = frame.f_code.co_name
622 if not name: name = '???'
623 fn = self.canonic(frame.f_code.co_filename)
624 line = linecache.getline(fn, frame.f_lineno, frame.f_globals)
625 print '+++', fn, frame.f_lineno, name, ':', line.strip()
626 def user_return(self, frame, retval):
627 print '+++ return', retval
628 def user_exception(self, frame, exc_stuff):
629 print '+++ exception', exc_stuff
630 self.set_continue()
631
632def foo(n):
633 print 'foo(', n, ')'
634 x = bar(n*10)
635 print 'bar returned', x
636
637def bar(a):
638 print 'bar(', a, ')'
639 return a/2
640
641def test():
642 t = Tdb()
643 t.run('import bdb; bdb.foo(10)')
644
645# end
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