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920dae64 AT |
1 | """Debugger basics""" |
2 | ||
3 | import sys | |
4 | import os | |
5 | import types | |
6 | ||
7 | __all__ = ["BdbQuit","Bdb","Breakpoint"] | |
8 | ||
9 | class BdbQuit(Exception): | |
10 | """Exception to give up completely""" | |
11 | ||
12 | ||
13 | class Bdb: | |
14 | ||
15 | """Generic Python debugger base class. | |
16 | ||
17 | This class takes care of details of the trace facility; | |
18 | a derived class should implement user interaction. | |
19 | The standard debugger class (pdb.Pdb) is an example. | |
20 | """ | |
21 | ||
22 | def __init__(self): | |
23 | self.breaks = {} | |
24 | self.fncache = {} | |
25 | ||
26 | def canonic(self, filename): | |
27 | if filename == "<" + filename[1:-1] + ">": | |
28 | return filename | |
29 | canonic = self.fncache.get(filename) | |
30 | if not canonic: | |
31 | canonic = os.path.abspath(filename) | |
32 | canonic = os.path.normcase(canonic) | |
33 | self.fncache[filename] = canonic | |
34 | return canonic | |
35 | ||
36 | def reset(self): | |
37 | import linecache | |
38 | linecache.checkcache() | |
39 | self.botframe = None | |
40 | self.stopframe = None | |
41 | self.returnframe = None | |
42 | self.quitting = 0 | |
43 | ||
44 | def trace_dispatch(self, frame, event, arg): | |
45 | if self.quitting: | |
46 | return # None | |
47 | if event == 'line': | |
48 | return self.dispatch_line(frame) | |
49 | if event == 'call': | |
50 | return self.dispatch_call(frame, arg) | |
51 | if event == 'return': | |
52 | return self.dispatch_return(frame, arg) | |
53 | if event == 'exception': | |
54 | return self.dispatch_exception(frame, arg) | |
55 | if event == 'c_call': | |
56 | return self.trace_dispatch | |
57 | if event == 'c_exception': | |
58 | return self.trace_dispatch | |
59 | if event == 'c_return': | |
60 | return self.trace_dispatch | |
61 | print 'bdb.Bdb.dispatch: unknown debugging event:', repr(event) | |
62 | return self.trace_dispatch | |
63 | ||
64 | def dispatch_line(self, frame): | |
65 | if self.stop_here(frame) or self.break_here(frame): | |
66 | self.user_line(frame) | |
67 | if self.quitting: raise BdbQuit | |
68 | return self.trace_dispatch | |
69 | ||
70 | def dispatch_call(self, frame, arg): | |
71 | # XXX 'arg' is no longer used | |
72 | if self.botframe is None: | |
73 | # First call of dispatch since reset() | |
74 | self.botframe = frame.f_back # (CT) Note that this may also be None! | |
75 | return self.trace_dispatch | |
76 | if not (self.stop_here(frame) or self.break_anywhere(frame)): | |
77 | # No need to trace this function | |
78 | return # None | |
79 | self.user_call(frame, arg) | |
80 | if self.quitting: raise BdbQuit | |
81 | return self.trace_dispatch | |
82 | ||
83 | def dispatch_return(self, frame, arg): | |
84 | if self.stop_here(frame) or frame == self.returnframe: | |
85 | self.user_return(frame, arg) | |
86 | if self.quitting: raise BdbQuit | |
87 | return self.trace_dispatch | |
88 | ||
89 | def dispatch_exception(self, frame, arg): | |
90 | if self.stop_here(frame): | |
91 | self.user_exception(frame, arg) | |
92 | if self.quitting: raise BdbQuit | |
93 | return self.trace_dispatch | |
94 | ||
95 | # Normally derived classes don't override the following | |
96 | # methods, but they may if they want to redefine the | |
97 | # definition of stopping and breakpoints. | |
98 | ||
99 | def stop_here(self, frame): | |
100 | # (CT) stopframe may now also be None, see dispatch_call. | |
101 | # (CT) the former test for None is therefore removed from here. | |
102 | if frame is self.stopframe: | |
103 | return True | |
104 | while frame is not None and frame is not self.stopframe: | |
105 | if frame is self.botframe: | |
106 | return True | |
107 | frame = frame.f_back | |
108 | return False | |
109 | ||
110 | def break_here(self, frame): | |
111 | filename = self.canonic(frame.f_code.co_filename) | |
112 | if not filename in self.breaks: | |
113 | return False | |
114 | lineno = frame.f_lineno | |
115 | if not lineno in self.breaks[filename]: | |
116 | # The line itself has no breakpoint, but maybe the line is the | |
117 | # first line of a function with breakpoint set by function name. | |
118 | lineno = frame.f_code.co_firstlineno | |
119 | if not lineno in self.breaks[filename]: | |
120 | return False | |
121 | ||
122 | # flag says ok to delete temp. bp | |
123 | (bp, flag) = effective(filename, lineno, frame) | |
124 | if bp: | |
125 | self.currentbp = bp.number | |
126 | if (flag and bp.temporary): | |
127 | self.do_clear(str(bp.number)) | |
128 | return True | |
129 | else: | |
130 | return False | |
131 | ||
132 | def do_clear(self, arg): | |
133 | raise NotImplementedError, "subclass of bdb must implement do_clear()" | |
134 | ||
135 | def break_anywhere(self, frame): | |
136 | return self.breaks.has_key( | |
137 | self.canonic(frame.f_code.co_filename)) | |
138 | ||
139 | # Derived classes should override the user_* methods | |
140 | # to gain control. | |
141 | ||
142 | def user_call(self, frame, argument_list): | |
143 | """This method is called when there is the remote possibility | |
144 | that we ever need to stop in this function.""" | |
145 | pass | |
146 | ||
147 | def user_line(self, frame): | |
148 | """This method is called when we stop or break at this line.""" | |
149 | pass | |
150 | ||
151 | def user_return(self, frame, return_value): | |
152 | """This method is called when a return trap is set here.""" | |
153 | pass | |
154 | ||
155 | def user_exception(self, frame, (exc_type, exc_value, exc_traceback)): | |
156 | """This method is called if an exception occurs, | |
157 | but only if we are to stop at or just below this level.""" | |
158 | pass | |
159 | ||
160 | # Derived classes and clients can call the following methods | |
161 | # to affect the stepping state. | |
162 | ||
163 | def set_step(self): | |
164 | """Stop after one line of code.""" | |
165 | self.stopframe = None | |
166 | self.returnframe = None | |
167 | self.quitting = 0 | |
168 | ||
169 | def set_next(self, frame): | |
170 | """Stop on the next line in or below the given frame.""" | |
171 | self.stopframe = frame | |
172 | self.returnframe = None | |
173 | self.quitting = 0 | |
174 | ||
175 | def set_return(self, frame): | |
176 | """Stop when returning from the given frame.""" | |
177 | self.stopframe = frame.f_back | |
178 | self.returnframe = frame | |
179 | self.quitting = 0 | |
180 | ||
181 | def set_trace(self, frame=None): | |
182 | """Start debugging from `frame`. | |
183 | ||
184 | If frame is not specified, debugging starts from caller's frame. | |
185 | """ | |
186 | if frame is None: | |
187 | frame = sys._getframe().f_back | |
188 | self.reset() | |
189 | while frame: | |
190 | frame.f_trace = self.trace_dispatch | |
191 | self.botframe = frame | |
192 | frame = frame.f_back | |
193 | self.set_step() | |
194 | sys.settrace(self.trace_dispatch) | |
195 | ||
196 | def set_continue(self): | |
197 | # Don't stop except at breakpoints or when finished | |
198 | self.stopframe = self.botframe | |
199 | self.returnframe = None | |
200 | self.quitting = 0 | |
201 | if not self.breaks: | |
202 | # no breakpoints; run without debugger overhead | |
203 | sys.settrace(None) | |
204 | frame = sys._getframe().f_back | |
205 | while frame and frame is not self.botframe: | |
206 | del frame.f_trace | |
207 | frame = frame.f_back | |
208 | ||
209 | def set_quit(self): | |
210 | self.stopframe = self.botframe | |
211 | self.returnframe = None | |
212 | self.quitting = 1 | |
213 | sys.settrace(None) | |
214 | ||
215 | # Derived classes and clients can call the following methods | |
216 | # to manipulate breakpoints. These methods return an | |
217 | # error message is something went wrong, None if all is well. | |
218 | # Set_break prints out the breakpoint line and file:lineno. | |
219 | # Call self.get_*break*() to see the breakpoints or better | |
220 | # for bp in Breakpoint.bpbynumber: if bp: bp.bpprint(). | |
221 | ||
222 | def set_break(self, filename, lineno, temporary=0, cond = None, | |
223 | funcname=None): | |
224 | filename = self.canonic(filename) | |
225 | import linecache # Import as late as possible | |
226 | line = linecache.getline(filename, lineno) | |
227 | if not line: | |
228 | return 'Line %s:%d does not exist' % (filename, | |
229 | lineno) | |
230 | if not filename in self.breaks: | |
231 | self.breaks[filename] = [] | |
232 | list = self.breaks[filename] | |
233 | if not lineno in list: | |
234 | list.append(lineno) | |
235 | bp = Breakpoint(filename, lineno, temporary, cond, funcname) | |
236 | ||
237 | def clear_break(self, filename, lineno): | |
238 | filename = self.canonic(filename) | |
239 | if not filename in self.breaks: | |
240 | return 'There are no breakpoints in %s' % filename | |
241 | if lineno not in self.breaks[filename]: | |
242 | return 'There is no breakpoint at %s:%d' % (filename, | |
243 | lineno) | |
244 | # If there's only one bp in the list for that file,line | |
245 | # pair, then remove the breaks entry | |
246 | for bp in Breakpoint.bplist[filename, lineno][:]: | |
247 | bp.deleteMe() | |
248 | if not Breakpoint.bplist.has_key((filename, lineno)): | |
249 | self.breaks[filename].remove(lineno) | |
250 | if not self.breaks[filename]: | |
251 | del self.breaks[filename] | |
252 | ||
253 | def clear_bpbynumber(self, arg): | |
254 | try: | |
255 | number = int(arg) | |
256 | except: | |
257 | return 'Non-numeric breakpoint number (%s)' % arg | |
258 | try: | |
259 | bp = Breakpoint.bpbynumber[number] | |
260 | except IndexError: | |
261 | return 'Breakpoint number (%d) out of range' % number | |
262 | if not bp: | |
263 | return 'Breakpoint (%d) already deleted' % number | |
264 | self.clear_break(bp.file, bp.line) | |
265 | ||
266 | def clear_all_file_breaks(self, filename): | |
267 | filename = self.canonic(filename) | |
268 | if not filename in self.breaks: | |
269 | return 'There are no breakpoints in %s' % filename | |
270 | for line in self.breaks[filename]: | |
271 | blist = Breakpoint.bplist[filename, line] | |
272 | for bp in blist: | |
273 | bp.deleteMe() | |
274 | del self.breaks[filename] | |
275 | ||
276 | def clear_all_breaks(self): | |
277 | if not self.breaks: | |
278 | return 'There are no breakpoints' | |
279 | for bp in Breakpoint.bpbynumber: | |
280 | if bp: | |
281 | bp.deleteMe() | |
282 | self.breaks = {} | |
283 | ||
284 | def get_break(self, filename, lineno): | |
285 | filename = self.canonic(filename) | |
286 | return filename in self.breaks and \ | |
287 | lineno in self.breaks[filename] | |
288 | ||
289 | def get_breaks(self, filename, lineno): | |
290 | filename = self.canonic(filename) | |
291 | return filename in self.breaks and \ | |
292 | lineno in self.breaks[filename] and \ | |
293 | Breakpoint.bplist[filename, lineno] or [] | |
294 | ||
295 | def get_file_breaks(self, filename): | |
296 | filename = self.canonic(filename) | |
297 | if filename in self.breaks: | |
298 | return self.breaks[filename] | |
299 | else: | |
300 | return [] | |
301 | ||
302 | def get_all_breaks(self): | |
303 | return self.breaks | |
304 | ||
305 | # Derived classes and clients can call the following method | |
306 | # to get a data structure representing a stack trace. | |
307 | ||
308 | def get_stack(self, f, t): | |
309 | stack = [] | |
310 | if t and t.tb_frame is f: | |
311 | t = t.tb_next | |
312 | while f is not None: | |
313 | stack.append((f, f.f_lineno)) | |
314 | if f is self.botframe: | |
315 | break | |
316 | f = f.f_back | |
317 | stack.reverse() | |
318 | i = max(0, len(stack) - 1) | |
319 | while t is not None: | |
320 | stack.append((t.tb_frame, t.tb_lineno)) | |
321 | t = t.tb_next | |
322 | return stack, i | |
323 | ||
324 | # | |
325 | ||
326 | def format_stack_entry(self, frame_lineno, lprefix=': '): | |
327 | import linecache, repr | |
328 | frame, lineno = frame_lineno | |
329 | filename = self.canonic(frame.f_code.co_filename) | |
330 | s = '%s(%r)' % (filename, lineno) | |
331 | if frame.f_code.co_name: | |
332 | s = s + frame.f_code.co_name | |
333 | else: | |
334 | s = s + "<lambda>" | |
335 | if '__args__' in frame.f_locals: | |
336 | args = frame.f_locals['__args__'] | |
337 | else: | |
338 | args = None | |
339 | if args: | |
340 | s = s + repr.repr(args) | |
341 | else: | |
342 | s = s + '()' | |
343 | if '__return__' in frame.f_locals: | |
344 | rv = frame.f_locals['__return__'] | |
345 | s = s + '->' | |
346 | s = s + repr.repr(rv) | |
347 | line = linecache.getline(filename, lineno) | |
348 | if line: s = s + lprefix + line.strip() | |
349 | return s | |
350 | ||
351 | # The following two methods can be called by clients to use | |
352 | # a debugger to debug a statement, given as a string. | |
353 | ||
354 | def run(self, cmd, globals=None, locals=None): | |
355 | if globals is None: | |
356 | import __main__ | |
357 | globals = __main__.__dict__ | |
358 | if locals is None: | |
359 | locals = globals | |
360 | self.reset() | |
361 | sys.settrace(self.trace_dispatch) | |
362 | if not isinstance(cmd, types.CodeType): | |
363 | cmd = cmd+'\n' | |
364 | try: | |
365 | try: | |
366 | exec cmd in globals, locals | |
367 | except BdbQuit: | |
368 | pass | |
369 | finally: | |
370 | self.quitting = 1 | |
371 | sys.settrace(None) | |
372 | ||
373 | def runeval(self, expr, globals=None, locals=None): | |
374 | if globals is None: | |
375 | import __main__ | |
376 | globals = __main__.__dict__ | |
377 | if locals is None: | |
378 | locals = globals | |
379 | self.reset() | |
380 | sys.settrace(self.trace_dispatch) | |
381 | if not isinstance(expr, types.CodeType): | |
382 | expr = expr+'\n' | |
383 | try: | |
384 | try: | |
385 | return eval(expr, globals, locals) | |
386 | except BdbQuit: | |
387 | pass | |
388 | finally: | |
389 | self.quitting = 1 | |
390 | sys.settrace(None) | |
391 | ||
392 | def runctx(self, cmd, globals, locals): | |
393 | # B/W compatibility | |
394 | self.run(cmd, globals, locals) | |
395 | ||
396 | # This method is more useful to debug a single function call. | |
397 | ||
398 | def runcall(self, func, *args, **kwds): | |
399 | self.reset() | |
400 | sys.settrace(self.trace_dispatch) | |
401 | res = None | |
402 | try: | |
403 | try: | |
404 | res = func(*args, **kwds) | |
405 | except BdbQuit: | |
406 | pass | |
407 | finally: | |
408 | self.quitting = 1 | |
409 | sys.settrace(None) | |
410 | return res | |
411 | ||
412 | ||
413 | def set_trace(): | |
414 | Bdb().set_trace() | |
415 | ||
416 | ||
417 | class Breakpoint: | |
418 | ||
419 | """Breakpoint class | |
420 | ||
421 | Implements temporary breakpoints, ignore counts, disabling and | |
422 | (re)-enabling, and conditionals. | |
423 | ||
424 | Breakpoints are indexed by number through bpbynumber and by | |
425 | the file,line tuple using bplist. The former points to a | |
426 | single instance of class Breakpoint. The latter points to a | |
427 | list of such instances since there may be more than one | |
428 | breakpoint per line. | |
429 | ||
430 | """ | |
431 | ||
432 | # XXX Keeping state in the class is a mistake -- this means | |
433 | # you cannot have more than one active Bdb instance. | |
434 | ||
435 | next = 1 # Next bp to be assigned | |
436 | bplist = {} # indexed by (file, lineno) tuple | |
437 | bpbynumber = [None] # Each entry is None or an instance of Bpt | |
438 | # index 0 is unused, except for marking an | |
439 | # effective break .... see effective() | |
440 | ||
441 | def __init__(self, file, line, temporary=0, cond=None, funcname=None): | |
442 | self.funcname = funcname | |
443 | # Needed if funcname is not None. | |
444 | self.func_first_executable_line = None | |
445 | self.file = file # This better be in canonical form! | |
446 | self.line = line | |
447 | self.temporary = temporary | |
448 | self.cond = cond | |
449 | self.enabled = 1 | |
450 | self.ignore = 0 | |
451 | self.hits = 0 | |
452 | self.number = Breakpoint.next | |
453 | Breakpoint.next = Breakpoint.next + 1 | |
454 | # Build the two lists | |
455 | self.bpbynumber.append(self) | |
456 | if self.bplist.has_key((file, line)): | |
457 | self.bplist[file, line].append(self) | |
458 | else: | |
459 | self.bplist[file, line] = [self] | |
460 | ||
461 | ||
462 | def deleteMe(self): | |
463 | index = (self.file, self.line) | |
464 | self.bpbynumber[self.number] = None # No longer in list | |
465 | self.bplist[index].remove(self) | |
466 | if not self.bplist[index]: | |
467 | # No more bp for this f:l combo | |
468 | del self.bplist[index] | |
469 | ||
470 | def enable(self): | |
471 | self.enabled = 1 | |
472 | ||
473 | def disable(self): | |
474 | self.enabled = 0 | |
475 | ||
476 | def bpprint(self): | |
477 | if self.temporary: | |
478 | disp = 'del ' | |
479 | else: | |
480 | disp = 'keep ' | |
481 | if self.enabled: | |
482 | disp = disp + 'yes' | |
483 | else: | |
484 | disp = disp + 'no ' | |
485 | print '%-4dbreakpoint %s at %s:%d' % (self.number, disp, | |
486 | self.file, self.line) | |
487 | if self.cond: | |
488 | print '\tstop only if %s' % (self.cond,) | |
489 | if self.ignore: | |
490 | print '\tignore next %d hits' % (self.ignore) | |
491 | if (self.hits): | |
492 | if (self.hits > 1): ss = 's' | |
493 | else: ss = '' | |
494 | print ('\tbreakpoint already hit %d time%s' % | |
495 | (self.hits, ss)) | |
496 | ||
497 | # -----------end of Breakpoint class---------- | |
498 | ||
499 | def checkfuncname(b, frame): | |
500 | """Check whether we should break here because of `b.funcname`.""" | |
501 | if not b.funcname: | |
502 | # Breakpoint was set via line number. | |
503 | if b.line != frame.f_lineno: | |
504 | # Breakpoint was set at a line with a def statement and the function | |
505 | # defined is called: don't break. | |
506 | return False | |
507 | return True | |
508 | ||
509 | # Breakpoint set via function name. | |
510 | ||
511 | if frame.f_code.co_name != b.funcname: | |
512 | # It's not a function call, but rather execution of def statement. | |
513 | return False | |
514 | ||
515 | # We are in the right frame. | |
516 | if not b.func_first_executable_line: | |
517 | # The function is entered for the 1st time. | |
518 | b.func_first_executable_line = frame.f_lineno | |
519 | ||
520 | if b.func_first_executable_line != frame.f_lineno: | |
521 | # But we are not at the first line number: don't break. | |
522 | return False | |
523 | return True | |
524 | ||
525 | # Determines if there is an effective (active) breakpoint at this | |
526 | # line of code. Returns breakpoint number or 0 if none | |
527 | def effective(file, line, frame): | |
528 | """Determine which breakpoint for this file:line is to be acted upon. | |
529 | ||
530 | Called only if we know there is a bpt at this | |
531 | location. Returns breakpoint that was triggered and a flag | |
532 | that indicates if it is ok to delete a temporary bp. | |
533 | ||
534 | """ | |
535 | possibles = Breakpoint.bplist[file,line] | |
536 | for i in range(0, len(possibles)): | |
537 | b = possibles[i] | |
538 | if b.enabled == 0: | |
539 | continue | |
540 | if not checkfuncname(b, frame): | |
541 | continue | |
542 | # Count every hit when bp is enabled | |
543 | b.hits = b.hits + 1 | |
544 | if not b.cond: | |
545 | # If unconditional, and ignoring, | |
546 | # go on to next, else break | |
547 | if b.ignore > 0: | |
548 | b.ignore = b.ignore -1 | |
549 | continue | |
550 | else: | |
551 | # breakpoint and marker that's ok | |
552 | # to delete if temporary | |
553 | return (b,1) | |
554 | else: | |
555 | # Conditional bp. | |
556 | # Ignore count applies only to those bpt hits where the | |
557 | # condition evaluates to true. | |
558 | try: | |
559 | val = eval(b.cond, frame.f_globals, | |
560 | frame.f_locals) | |
561 | if val: | |
562 | if b.ignore > 0: | |
563 | b.ignore = b.ignore -1 | |
564 | # continue | |
565 | else: | |
566 | return (b,1) | |
567 | # else: | |
568 | # continue | |
569 | except: | |
570 | # if eval fails, most conservative | |
571 | # thing is to stop on breakpoint | |
572 | # regardless of ignore count. | |
573 | # Don't delete temporary, | |
574 | # as another hint to user. | |
575 | return (b,0) | |
576 | return (None, None) | |
577 | ||
578 | # -------------------- testing -------------------- | |
579 | ||
580 | class Tdb(Bdb): | |
581 | def user_call(self, frame, args): | |
582 | name = frame.f_code.co_name | |
583 | if not name: name = '???' | |
584 | print '+++ call', name, args | |
585 | def user_line(self, frame): | |
586 | import linecache | |
587 | name = frame.f_code.co_name | |
588 | if not name: name = '???' | |
589 | fn = self.canonic(frame.f_code.co_filename) | |
590 | line = linecache.getline(fn, frame.f_lineno) | |
591 | print '+++', fn, frame.f_lineno, name, ':', line.strip() | |
592 | def user_return(self, frame, retval): | |
593 | print '+++ return', retval | |
594 | def user_exception(self, frame, exc_stuff): | |
595 | print '+++ exception', exc_stuff | |
596 | self.set_continue() | |
597 | ||
598 | def foo(n): | |
599 | print 'foo(', n, ')' | |
600 | x = bar(n*10) | |
601 | print 'bar returned', x | |
602 | ||
603 | def bar(a): | |
604 | print 'bar(', a, ')' | |
605 | return a/2 | |
606 | ||
607 | def test(): | |
608 | t = Tdb() | |
609 | t.run('import bdb; bdb.foo(10)') | |
610 | ||
611 | # end |