| """Debugger basics""" |
| |
| import fnmatch |
| import sys |
| import os |
| from inspect import CO_GENERATOR |
| |
| __all__ = ["BdbQuit", "Bdb", "Breakpoint"] |
| |
| class BdbQuit(Exception): |
| """Exception to give up completely.""" |
| |
| |
| class Bdb: |
| """Generic Python debugger base class. |
| |
| This class takes care of details of the trace facility; |
| a derived class should implement user interaction. |
| The standard debugger class (pdb.Pdb) is an example. |
| """ |
| |
| def __init__(self, skip=None): |
| self.skip = set(skip) if skip else None |
| self.breaks = {} |
| self.fncache = {} |
| self.frame_returning = None |
| |
| def canonic(self, filename): |
| if filename == "<" + filename[1:-1] + ">": |
| return filename |
| canonic = self.fncache.get(filename) |
| if not canonic: |
| canonic = os.path.abspath(filename) |
| canonic = os.path.normcase(canonic) |
| self.fncache[filename] = canonic |
| return canonic |
| |
| def reset(self): |
| import linecache |
| linecache.checkcache() |
| self.botframe = None |
| self._set_stopinfo(None, None) |
| |
| def trace_dispatch(self, frame, event, arg): |
| if self.quitting: |
| return # None |
| if event == 'line': |
| return self.dispatch_line(frame) |
| if event == 'call': |
| return self.dispatch_call(frame, arg) |
| if event == 'return': |
| return self.dispatch_return(frame, arg) |
| if event == 'exception': |
| return self.dispatch_exception(frame, arg) |
| if event == 'c_call': |
| return self.trace_dispatch |
| if event == 'c_exception': |
| return self.trace_dispatch |
| if event == 'c_return': |
| return self.trace_dispatch |
| print('bdb.Bdb.dispatch: unknown debugging event:', repr(event)) |
| return self.trace_dispatch |
| |
| def dispatch_line(self, frame): |
| if self.stop_here(frame) or self.break_here(frame): |
| self.user_line(frame) |
| if self.quitting: raise BdbQuit |
| return self.trace_dispatch |
| |
| def dispatch_call(self, frame, arg): |
| # XXX 'arg' is no longer used |
| if self.botframe is None: |
| # First call of dispatch since reset() |
| self.botframe = frame.f_back # (CT) Note that this may also be None! |
| return self.trace_dispatch |
| if not (self.stop_here(frame) or self.break_anywhere(frame)): |
| # No need to trace this function |
| return # None |
| # Ignore call events in generator except when stepping. |
| if self.stopframe and frame.f_code.co_flags & CO_GENERATOR: |
| return self.trace_dispatch |
| self.user_call(frame, arg) |
| if self.quitting: raise BdbQuit |
| return self.trace_dispatch |
| |
| def dispatch_return(self, frame, arg): |
| if self.stop_here(frame) or frame == self.returnframe: |
| # Ignore return events in generator except when stepping. |
| if self.stopframe and frame.f_code.co_flags & CO_GENERATOR: |
| return self.trace_dispatch |
| try: |
| self.frame_returning = frame |
| self.user_return(frame, arg) |
| finally: |
| self.frame_returning = None |
| if self.quitting: raise BdbQuit |
| # The user issued a 'next' or 'until' command. |
| if self.stopframe is frame and self.stoplineno != -1: |
| self._set_stopinfo(None, None) |
| return self.trace_dispatch |
| |
| def dispatch_exception(self, frame, arg): |
| if self.stop_here(frame): |
| # When stepping with next/until/return in a generator frame, skip |
| # the internal StopIteration exception (with no traceback) |
| # triggered by a subiterator run with the 'yield from' statement. |
| if not (frame.f_code.co_flags & CO_GENERATOR |
| and arg[0] is StopIteration and arg[2] is None): |
| self.user_exception(frame, arg) |
| if self.quitting: raise BdbQuit |
| # Stop at the StopIteration or GeneratorExit exception when the user |
| # has set stopframe in a generator by issuing a return command, or a |
| # next/until command at the last statement in the generator before the |
| # exception. |
| elif (self.stopframe and frame is not self.stopframe |
| and self.stopframe.f_code.co_flags & CO_GENERATOR |
| and arg[0] in (StopIteration, GeneratorExit)): |
| self.user_exception(frame, arg) |
| if self.quitting: raise BdbQuit |
| |
| return self.trace_dispatch |
| |
| # Normally derived classes don't override the following |
| # methods, but they may if they want to redefine the |
| # definition of stopping and breakpoints. |
| |
| def is_skipped_module(self, module_name): |
| for pattern in self.skip: |
| if fnmatch.fnmatch(module_name, pattern): |
| return True |
| return False |
| |
| def stop_here(self, frame): |
| # (CT) stopframe may now also be None, see dispatch_call. |
| # (CT) the former test for None is therefore removed from here. |
| if self.skip and \ |
| self.is_skipped_module(frame.f_globals.get('__name__')): |
| return False |
| if frame is self.stopframe: |
| if self.stoplineno == -1: |
| return False |
| return frame.f_lineno >= self.stoplineno |
| if not self.stopframe: |
| return True |
| return False |
| |
| def break_here(self, frame): |
| filename = self.canonic(frame.f_code.co_filename) |
| if filename not in self.breaks: |
| return False |
| lineno = frame.f_lineno |
| if lineno not in self.breaks[filename]: |
| # The line itself has no breakpoint, but maybe the line is the |
| # first line of a function with breakpoint set by function name. |
| lineno = frame.f_code.co_firstlineno |
| if lineno not in self.breaks[filename]: |
| return False |
| |
| # flag says ok to delete temp. bp |
| (bp, flag) = effective(filename, lineno, frame) |
| if bp: |
| self.currentbp = bp.number |
| if (flag and bp.temporary): |
| self.do_clear(str(bp.number)) |
| return True |
| else: |
| return False |
| |
| def do_clear(self, arg): |
| raise NotImplementedError("subclass of bdb must implement do_clear()") |
| |
| def break_anywhere(self, frame): |
| return self.canonic(frame.f_code.co_filename) in self.breaks |
| |
| # Derived classes should override the user_* methods |
| # to gain control. |
| |
| def user_call(self, frame, argument_list): |
| """This method is called when there is the remote possibility |
| that we ever need to stop in this function.""" |
| pass |
| |
| def user_line(self, frame): |
| """This method is called when we stop or break at this line.""" |
| pass |
| |
| def user_return(self, frame, return_value): |
| """This method is called when a return trap is set here.""" |
| pass |
| |
| def user_exception(self, frame, exc_info): |
| """This method is called if an exception occurs, |
| but only if we are to stop at or just below this level.""" |
| pass |
| |
| def _set_stopinfo(self, stopframe, returnframe, stoplineno=0): |
| self.stopframe = stopframe |
| self.returnframe = returnframe |
| self.quitting = False |
| # stoplineno >= 0 means: stop at line >= the stoplineno |
| # stoplineno -1 means: don't stop at all |
| self.stoplineno = stoplineno |
| |
| # Derived classes and clients can call the following methods |
| # to affect the stepping state. |
| |
| def set_until(self, frame, lineno=None): |
| """Stop when the line with the line no greater than the current one is |
| reached or when returning from current frame""" |
| # the name "until" is borrowed from gdb |
| if lineno is None: |
| lineno = frame.f_lineno + 1 |
| self._set_stopinfo(frame, frame, lineno) |
| |
| def set_step(self): |
| """Stop after one line of code.""" |
| # Issue #13183: pdb skips frames after hitting a breakpoint and running |
| # step commands. |
| # Restore the trace function in the caller (that may not have been set |
| # for performance reasons) when returning from the current frame. |
| if self.frame_returning: |
| caller_frame = self.frame_returning.f_back |
| if caller_frame and not caller_frame.f_trace: |
| caller_frame.f_trace = self.trace_dispatch |
| self._set_stopinfo(None, None) |
| |
| def set_next(self, frame): |
| """Stop on the next line in or below the given frame.""" |
| self._set_stopinfo(frame, None) |
| |
| def set_return(self, frame): |
| """Stop when returning from the given frame.""" |
| if frame.f_code.co_flags & CO_GENERATOR: |
| self._set_stopinfo(frame, None, -1) |
| else: |
| self._set_stopinfo(frame.f_back, frame) |
| |
| def set_trace(self, frame=None): |
| """Start debugging from `frame`. |
| |
| If frame is not specified, debugging starts from caller's frame. |
| """ |
| if frame is None: |
| frame = sys._getframe().f_back |
| self.reset() |
| while frame: |
| frame.f_trace = self.trace_dispatch |
| self.botframe = frame |
| frame = frame.f_back |
| self.set_step() |
| sys.settrace(self.trace_dispatch) |
| |
| def set_continue(self): |
| # Don't stop except at breakpoints or when finished |
| self._set_stopinfo(self.botframe, None, -1) |
| if not self.breaks: |
| # no breakpoints; run without debugger overhead |
| sys.settrace(None) |
| frame = sys._getframe().f_back |
| while frame and frame is not self.botframe: |
| del frame.f_trace |
| frame = frame.f_back |
| |
| def set_quit(self): |
| self.stopframe = self.botframe |
| self.returnframe = None |
| self.quitting = True |
| sys.settrace(None) |
| |
| # Derived classes and clients can call the following methods |
| # to manipulate breakpoints. These methods return an |
| # error message is something went wrong, None if all is well. |
| # Set_break prints out the breakpoint line and file:lineno. |
| # Call self.get_*break*() to see the breakpoints or better |
| # for bp in Breakpoint.bpbynumber: if bp: bp.bpprint(). |
| |
| def set_break(self, filename, lineno, temporary=False, cond=None, |
| funcname=None): |
| filename = self.canonic(filename) |
| import linecache # Import as late as possible |
| line = linecache.getline(filename, lineno) |
| if not line: |
| return 'Line %s:%d does not exist' % (filename, lineno) |
| list = self.breaks.setdefault(filename, []) |
| if lineno not in list: |
| list.append(lineno) |
| bp = Breakpoint(filename, lineno, temporary, cond, funcname) |
| |
| def _prune_breaks(self, filename, lineno): |
| if (filename, lineno) not in Breakpoint.bplist: |
| self.breaks[filename].remove(lineno) |
| if not self.breaks[filename]: |
| del self.breaks[filename] |
| |
| def clear_break(self, filename, lineno): |
| filename = self.canonic(filename) |
| if filename not in self.breaks: |
| return 'There are no breakpoints in %s' % filename |
| if lineno not in self.breaks[filename]: |
| return 'There is no breakpoint at %s:%d' % (filename, lineno) |
| # If there's only one bp in the list for that file,line |
| # pair, then remove the breaks entry |
| for bp in Breakpoint.bplist[filename, lineno][:]: |
| bp.deleteMe() |
| self._prune_breaks(filename, lineno) |
| |
| def clear_bpbynumber(self, arg): |
| try: |
| bp = self.get_bpbynumber(arg) |
| except ValueError as err: |
| return str(err) |
| bp.deleteMe() |
| self._prune_breaks(bp.file, bp.line) |
| |
| def clear_all_file_breaks(self, filename): |
| filename = self.canonic(filename) |
| if filename not in self.breaks: |
| return 'There are no breakpoints in %s' % filename |
| for line in self.breaks[filename]: |
| blist = Breakpoint.bplist[filename, line] |
| for bp in blist: |
| bp.deleteMe() |
| del self.breaks[filename] |
| |
| def clear_all_breaks(self): |
| if not self.breaks: |
| return 'There are no breakpoints' |
| for bp in Breakpoint.bpbynumber: |
| if bp: |
| bp.deleteMe() |
| self.breaks = {} |
| |
| def get_bpbynumber(self, arg): |
| if not arg: |
| raise ValueError('Breakpoint number expected') |
| try: |
| number = int(arg) |
| except ValueError: |
| raise ValueError('Non-numeric breakpoint number %s' % arg) |
| try: |
| bp = Breakpoint.bpbynumber[number] |
| except IndexError: |
| raise ValueError('Breakpoint number %d out of range' % number) |
| if bp is None: |
| raise ValueError('Breakpoint %d already deleted' % number) |
| return bp |
| |
| def get_break(self, filename, lineno): |
| filename = self.canonic(filename) |
| return filename in self.breaks and \ |
| lineno in self.breaks[filename] |
| |
| def get_breaks(self, filename, lineno): |
| filename = self.canonic(filename) |
| return filename in self.breaks and \ |
| lineno in self.breaks[filename] and \ |
| Breakpoint.bplist[filename, lineno] or [] |
| |
| def get_file_breaks(self, filename): |
| filename = self.canonic(filename) |
| if filename in self.breaks: |
| return self.breaks[filename] |
| else: |
| return [] |
| |
| def get_all_breaks(self): |
| return self.breaks |
| |
| # Derived classes and clients can call the following method |
| # to get a data structure representing a stack trace. |
| |
| def get_stack(self, f, t): |
| stack = [] |
| if t and t.tb_frame is f: |
| t = t.tb_next |
| while f is not None: |
| stack.append((f, f.f_lineno)) |
| if f is self.botframe: |
| break |
| f = f.f_back |
| stack.reverse() |
| i = max(0, len(stack) - 1) |
| while t is not None: |
| stack.append((t.tb_frame, t.tb_lineno)) |
| t = t.tb_next |
| if f is None: |
| i = max(0, len(stack) - 1) |
| return stack, i |
| |
| def format_stack_entry(self, frame_lineno, lprefix=': '): |
| import linecache, reprlib |
| frame, lineno = frame_lineno |
| filename = self.canonic(frame.f_code.co_filename) |
| s = '%s(%r)' % (filename, lineno) |
| if frame.f_code.co_name: |
| s += frame.f_code.co_name |
| else: |
| s += "<lambda>" |
| if '__args__' in frame.f_locals: |
| args = frame.f_locals['__args__'] |
| else: |
| args = None |
| if args: |
| s += reprlib.repr(args) |
| else: |
| s += '()' |
| if '__return__' in frame.f_locals: |
| rv = frame.f_locals['__return__'] |
| s += '->' |
| s += reprlib.repr(rv) |
| line = linecache.getline(filename, lineno, frame.f_globals) |
| if line: |
| s += lprefix + line.strip() |
| return s |
| |
| # The following methods can be called by clients to use |
| # a debugger to debug a statement or an expression. |
| # Both can be given as a string, or a code object. |
| |
| def run(self, cmd, globals=None, locals=None): |
| if globals is None: |
| import __main__ |
| globals = __main__.__dict__ |
| if locals is None: |
| locals = globals |
| self.reset() |
| if isinstance(cmd, str): |
| cmd = compile(cmd, "<string>", "exec") |
| sys.settrace(self.trace_dispatch) |
| try: |
| exec(cmd, globals, locals) |
| except BdbQuit: |
| pass |
| finally: |
| self.quitting = True |
| sys.settrace(None) |
| |
| def runeval(self, expr, globals=None, locals=None): |
| if globals is None: |
| import __main__ |
| globals = __main__.__dict__ |
| if locals is None: |
| locals = globals |
| self.reset() |
| sys.settrace(self.trace_dispatch) |
| try: |
| return eval(expr, globals, locals) |
| except BdbQuit: |
| pass |
| finally: |
| self.quitting = True |
| sys.settrace(None) |
| |
| def runctx(self, cmd, globals, locals): |
| # B/W compatibility |
| self.run(cmd, globals, locals) |
| |
| # This method is more useful to debug a single function call. |
| |
| def runcall(self, func, *args, **kwds): |
| self.reset() |
| sys.settrace(self.trace_dispatch) |
| res = None |
| try: |
| res = func(*args, **kwds) |
| except BdbQuit: |
| pass |
| finally: |
| self.quitting = True |
| sys.settrace(None) |
| return res |
| |
| |
| def set_trace(): |
| Bdb().set_trace() |
| |
| |
| class Breakpoint: |
| """Breakpoint class. |
| |
| Implements temporary breakpoints, ignore counts, disabling and |
| (re)-enabling, and conditionals. |
| |
| Breakpoints are indexed by number through bpbynumber and by |
| the file,line tuple using bplist. The former points to a |
| single instance of class Breakpoint. The latter points to a |
| list of such instances since there may be more than one |
| breakpoint per line. |
| |
| """ |
| |
| # XXX Keeping state in the class is a mistake -- this means |
| # you cannot have more than one active Bdb instance. |
| |
| next = 1 # Next bp to be assigned |
| bplist = {} # indexed by (file, lineno) tuple |
| bpbynumber = [None] # Each entry is None or an instance of Bpt |
| # index 0 is unused, except for marking an |
| # effective break .... see effective() |
| |
| def __init__(self, file, line, temporary=False, cond=None, funcname=None): |
| self.funcname = funcname |
| # Needed if funcname is not None. |
| self.func_first_executable_line = None |
| self.file = file # This better be in canonical form! |
| self.line = line |
| self.temporary = temporary |
| self.cond = cond |
| self.enabled = True |
| self.ignore = 0 |
| self.hits = 0 |
| self.number = Breakpoint.next |
| Breakpoint.next += 1 |
| # Build the two lists |
| self.bpbynumber.append(self) |
| if (file, line) in self.bplist: |
| self.bplist[file, line].append(self) |
| else: |
| self.bplist[file, line] = [self] |
| |
| def deleteMe(self): |
| index = (self.file, self.line) |
| self.bpbynumber[self.number] = None # No longer in list |
| self.bplist[index].remove(self) |
| if not self.bplist[index]: |
| # No more bp for this f:l combo |
| del self.bplist[index] |
| |
| def enable(self): |
| self.enabled = True |
| |
| def disable(self): |
| self.enabled = False |
| |
| def bpprint(self, out=None): |
| if out is None: |
| out = sys.stdout |
| print(self.bpformat(), file=out) |
| |
| def bpformat(self): |
| if self.temporary: |
| disp = 'del ' |
| else: |
| disp = 'keep ' |
| if self.enabled: |
| disp = disp + 'yes ' |
| else: |
| disp = disp + 'no ' |
| ret = '%-4dbreakpoint %s at %s:%d' % (self.number, disp, |
| self.file, self.line) |
| if self.cond: |
| ret += '\n\tstop only if %s' % (self.cond,) |
| if self.ignore: |
| ret += '\n\tignore next %d hits' % (self.ignore,) |
| if self.hits: |
| if self.hits > 1: |
| ss = 's' |
| else: |
| ss = '' |
| ret += '\n\tbreakpoint already hit %d time%s' % (self.hits, ss) |
| return ret |
| |
| def __str__(self): |
| return 'breakpoint %s at %s:%s' % (self.number, self.file, self.line) |
| |
| # -----------end of Breakpoint class---------- |
| |
| def checkfuncname(b, frame): |
| """Check whether we should break here because of `b.funcname`.""" |
| if not b.funcname: |
| # Breakpoint was set via line number. |
| if b.line != frame.f_lineno: |
| # Breakpoint was set at a line with a def statement and the function |
| # defined is called: don't break. |
| return False |
| return True |
| |
| # Breakpoint set via function name. |
| |
| if frame.f_code.co_name != b.funcname: |
| # It's not a function call, but rather execution of def statement. |
| return False |
| |
| # We are in the right frame. |
| if not b.func_first_executable_line: |
| # The function is entered for the 1st time. |
| b.func_first_executable_line = frame.f_lineno |
| |
| if b.func_first_executable_line != frame.f_lineno: |
| # But we are not at the first line number: don't break. |
| return False |
| return True |
| |
| # Determines if there is an effective (active) breakpoint at this |
| # line of code. Returns breakpoint number or 0 if none |
| def effective(file, line, frame): |
| """Determine which breakpoint for this file:line is to be acted upon. |
| |
| Called only if we know there is a bpt at this |
| location. Returns breakpoint that was triggered and a flag |
| that indicates if it is ok to delete a temporary bp. |
| |
| """ |
| possibles = Breakpoint.bplist[file, line] |
| for b in possibles: |
| if not b.enabled: |
| continue |
| if not checkfuncname(b, frame): |
| continue |
| # Count every hit when bp is enabled |
| b.hits += 1 |
| if not b.cond: |
| # If unconditional, and ignoring go on to next, else break |
| if b.ignore > 0: |
| b.ignore -= 1 |
| continue |
| else: |
| # breakpoint and marker that it's ok to delete if temporary |
| return (b, True) |
| else: |
| # Conditional bp. |
| # Ignore count applies only to those bpt hits where the |
| # condition evaluates to true. |
| try: |
| val = eval(b.cond, frame.f_globals, frame.f_locals) |
| if val: |
| if b.ignore > 0: |
| b.ignore -= 1 |
| # continue |
| else: |
| return (b, True) |
| # else: |
| # continue |
| except: |
| # if eval fails, most conservative thing is to stop on |
| # breakpoint regardless of ignore count. Don't delete |
| # temporary, as another hint to user. |
| return (b, False) |
| return (None, None) |
| |
| |
| # -------------------- testing -------------------- |
| |
| class Tdb(Bdb): |
| def user_call(self, frame, args): |
| name = frame.f_code.co_name |
| if not name: name = '???' |
| print('+++ call', name, args) |
| def user_line(self, frame): |
| import linecache |
| name = frame.f_code.co_name |
| if not name: name = '???' |
| fn = self.canonic(frame.f_code.co_filename) |
| line = linecache.getline(fn, frame.f_lineno, frame.f_globals) |
| print('+++', fn, frame.f_lineno, name, ':', line.strip()) |
| def user_return(self, frame, retval): |
| print('+++ return', retval) |
| def user_exception(self, frame, exc_stuff): |
| print('+++ exception', exc_stuff) |
| self.set_continue() |
| |
| def foo(n): |
| print('foo(', n, ')') |
| x = bar(n*10) |
| print('bar returned', x) |
| |
| def bar(a): |
| print('bar(', a, ')') |
| return a/2 |
| |
| def test(): |
| t = Tdb() |
| t.run('import bdb; bdb.foo(10)') |