"""Debugger basics"""

import fnmatch

import sys

import os

import weakref

from inspect import CO_GENERATOR, CO_COROUTINE, CO_ASYNC_GENERATOR

__all__ = ["BdbQuit", "Bdb", "Breakpoint"]

GENERATOR_AND_COROUTINE_FLAGS = CO_GENERATOR | CO_COROUTINE | CO_ASYNC_GENERATOR

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.

The optional skip argument must be an iterable of glob-style

module name patterns. The debugger will not step into frames

that originate in a module that matches one of these patterns.

Whether a frame is considered to originate in a certain module

is determined by the __name__ in the frame globals.

"""

def __init__(self, skip=None):

self.skip = set(skip) if skip else None

self.breaks = {}

self.fncache = {}

self.frame_trace_lines_opcodes = {}

self.frame_returning = None

self.trace_opcodes = False

self.enterframe = None

self.code_linenos = weakref.WeakKeyDictionary()

self._load_breaks()

def canonic(self, filename):

"""Return canonical form of filename.

For real filenames, the canonical form is a case-normalized (on

case insensitive filesystems) absolute path. 'Filenames' with

angle brackets, such as "<stdin>", generated in interactive

mode, are returned unchanged.

"""

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):

"""Set values of attributes as ready to start debugging."""

import linecache

linecache.checkcache()

self.botframe = None

self._set_stopinfo(None, None)

def trace_dispatch(self, frame, event, arg):

"""Dispatch a trace function for debugged frames based on the event.

This function is installed as the trace function for debugged

frames. Its return value is the new trace function, which is

usually itself. The default implementation decides how to

dispatch a frame, depending on the type of event (passed in as a

string) that is about to be executed.

The event can be one of the following:

line: A new line of code is going to be executed.

call: A function is about to be called or another code block

is entered.

return: A function or other code block is about to return.

exception: An exception has occurred.

c_call: A C function is about to be called.

c_return: A C function has returned.

c_exception: A C function has raised an exception.

For the Python events, specialized functions (see the dispatch_*()

methods) are called. For the C events, no action is taken.

The arg parameter depends on the previous event.

"""

self.enterframe = frame

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

if event == 'opcode':

return self.dispatch_opcode(frame, arg)

print('bdb.Bdb.dispatch: unknown debugging event:', repr(event))

return self.trace_dispatch

def dispatch_line(self, frame):

"""Invoke user function and return trace function for line event.

If the debugger stops on the current line, invoke

self.user_line(). Raise BdbQuit if self.quitting is set.

Return self.trace_dispatch to continue tracing in this scope.

"""

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):

"""Invoke user function and return trace function for call event.

If the debugger stops on this function call, invoke

self.user_call(). Raise BdbQuit if self.quitting is set.

Return self.trace_dispatch to continue tracing in this scope.

"""

# 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 & GENERATOR_AND_COROUTINE_FLAGS:

return self.trace_dispatch

self.user_call(frame, arg)

if self.quitting: raise BdbQuit

return self.trace_dispatch

def dispatch_return(self, frame, arg):

"""Invoke user function and return trace function for return event.

If the debugger stops on this function return, invoke

self.user_return(). Raise BdbQuit if self.quitting is set.

Return self.trace_dispatch to continue tracing in this scope.

"""

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 & GENERATOR_AND_COROUTINE_FLAGS:

# It's possible to trigger a StopIteration exception in

# the caller so we must set the trace function in the caller

self._set_caller_tracefunc(frame)

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)

# The previous frame might not have f_trace set, unless we are

# issuing a command that does not expect to stop, we should set

# f_trace

if self.stoplineno != -1:

self._set_caller_tracefunc(frame)

return self.trace_dispatch

def dispatch_exception(self, frame, arg):

"""Invoke user function and return trace function for exception event.

If the debugger stops on this exception, invoke

self.user_exception(). Raise BdbQuit if self.quitting is set.

Return self.trace_dispatch to continue tracing in this scope.

"""

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 & GENERATOR_AND_COROUTINE_FLAGS

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 & GENERATOR_AND_COROUTINE_FLAGS

and arg[0] in (StopIteration, GeneratorExit)):

self.user_exception(frame, arg)

if self.quitting: raise BdbQuit

return self.trace_dispatch

def dispatch_opcode(self, frame, arg):

"""Invoke user function and return trace function for opcode event.

If the debugger stops on the current opcode, invoke

self.user_opcode(). Raise BdbQuit if self.quitting is set.

Return self.trace_dispatch to continue tracing in this scope.

"""

if self.stop_here(frame) or self.break_here(frame):

self.user_opcode(frame)

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):

"Return True if module_name matches any skip pattern."

if module_name is None: # some modules do not have names

return False

for pattern in self.skip:

if fnmatch.fnmatch(module_name, pattern):

return True

return False

def stop_here(self, frame):

"Return True if frame is below the starting frame in the stack."

# (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):

"""Return True if there is an effective breakpoint for this line.

Check for line or function breakpoint and if in effect.

Delete temporary breakpoints if effective() says to.

"""

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):

"""Remove temporary breakpoint.

Must implement in derived classes or get NotImplementedError.

"""

raise NotImplementedError("subclass of bdb must implement do_clear()")

def break_anywhere(self, frame):

"""Return True if there is any breakpoint in that frame

"""

filename = self.canonic(frame.f_code.co_filename)

if filename not in self.breaks:

return False

for lineno in self.breaks[filename]:

if self._lineno_in_frame(lineno, frame):

return True

return False

def _lineno_in_frame(self, lineno, frame):

"""Return True if the line number is in the frame's code object.

"""

code = frame.f_code

if lineno < code.co_firstlineno:

return False

if code not in self.code_linenos:

self.code_linenos[code] = set(lineno for _, _, lineno in code.co_lines())

return lineno in self.code_linenos[code]

# Derived classes should override the user_* methods

# to gain control.

def user_call(self, frame, argument_list):

"""Called if we might stop in a function."""

pass

def user_line(self, frame):

"""Called when we stop or break at a line."""

pass

def user_return(self, frame, return_value):

"""Called when a return trap is set here."""

pass

def user_exception(self, frame, exc_info):

"""Called when we stop on an exception."""

pass

def user_opcode(self, frame):

"""Called when we are about to execute an opcode."""

pass

def _set_trace_opcodes(self, trace_opcodes):

if trace_opcodes != self.trace_opcodes:

self.trace_opcodes = trace_opcodes

frame = self.enterframe

while frame is not None:

frame.f_trace_opcodes = trace_opcodes

if frame is self.botframe:

break

frame = frame.f_back

def _set_stopinfo(self, stopframe, returnframe, stoplineno=0, opcode=False):

"""Set the attributes for stopping.

If stoplineno is greater than or equal to 0, then stop at line

greater than or equal to the stopline. If stoplineno is -1, then

don't stop at all.

"""

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

self._set_trace_opcodes(opcode)

def _set_caller_tracefunc(self, current_frame):

# 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, unless

# the caller is the botframe.

caller_frame = current_frame.f_back

if caller_frame and not caller_frame.f_trace and caller_frame is not self.botframe:

caller_frame.f_trace = self.trace_dispatch

# 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 lineno 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."""

self._set_stopinfo(None, None)

def set_stepinstr(self):

"""Stop before the next instruction."""

self._set_stopinfo(None, None, opcode=True)

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 & GENERATOR_AND_COROUTINE_FLAGS:

self._set_stopinfo(frame, frame, -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.

"""

sys.settrace(None)

if frame is None:

frame = sys._getframe().f_back

self.reset()

self.enterframe = frame

while frame:

frame.f_trace = self.trace_dispatch

self.botframe = frame

self.frame_trace_lines_opcodes[frame] = (frame.f_trace_lines, frame.f_trace_opcodes)

# We need f_trace_lines == True for the debugger to work

frame.f_trace_lines = True

frame = frame.f_back

self.set_stepinstr()

self.enterframe = None

sys.settrace(self.trace_dispatch)

def set_continue(self):

"""Stop only at breakpoints or when finished.

If there are no breakpoints, set the system trace function to None.

"""

# 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

for frame, (trace_lines, trace_opcodes) in self.frame_trace_lines_opcodes.items():

frame.f_trace_lines, frame.f_trace_opcodes = trace_lines, trace_opcodes

self.frame_trace_lines_opcodes = {}

self.enterframe = None

def set_quit(self):

"""Set quitting attribute to True.

Raises BdbQuit exception in the next call to a dispatch_*() method.

"""

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 if 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 _add_to_breaks(self, filename, lineno):

"""Add breakpoint to breaks, if not already there."""

bp_linenos = self.breaks.setdefault(filename, [])

if lineno not in bp_linenos:

bp_linenos.append(lineno)

def set_break(self, filename, lineno, temporary=False, cond=None,

funcname=None):

"""Set a new breakpoint for filename:lineno.

If lineno doesn't exist for the filename, return an error message.

The filename should be in canonical form.

"""

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)

self._add_to_breaks(filename, lineno)

bp = Breakpoint(filename, lineno, temporary, cond, funcname)

# After we set a new breakpoint, we need to search through all frames

# and set f_trace to trace_dispatch if there could be a breakpoint in

# that frame.

frame = self.enterframe

while frame:

if self.break_anywhere(frame):

frame.f_trace = self.trace_dispatch

frame = frame.f_back

return None

def _load_breaks(self):

"""Apply all breakpoints (set in other instances) to this one.

Populates this instance's breaks list from the Breakpoint class's

list, which can have breakpoints set by another Bdb instance. This

is necessary for interactive sessions to keep the breakpoints

active across multiple calls to run().

"""

for (filename, lineno) in Breakpoint.bplist.keys():

self._add_to_breaks(filename, lineno)

def _prune_breaks(self, filename, lineno):

"""Prune breakpoints for filename:lineno.

A list of breakpoints is maintained in the Bdb instance and in

the Breakpoint class. If a breakpoint in the Bdb instance no

longer exists in the Breakpoint class, then it's removed from the

Bdb instance.

"""

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):

"""Delete breakpoints for filename:lineno.

If no breakpoints were set, return an error message.

"""

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)

return None

def clear_bpbynumber(self, arg):

"""Delete a breakpoint by its index in Breakpoint.bpbynumber.

If arg is invalid, return an error message.

"""

try:

bp = self.get_bpbynumber(arg)

except ValueError as err:

return str(err)

bp.deleteMe()

self._prune_breaks(bp.file, bp.line)

return None

def clear_all_file_breaks(self, filename):

"""Delete all breakpoints in filename.

If none were set, return an error message.

"""

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]

return None

def clear_all_breaks(self):

"""Delete all existing breakpoints.

If none were set, return an error message.

"""

if not self.breaks:

return 'There are no breakpoints'

for bp in Breakpoint.bpbynumber:

if bp:

bp.deleteMe()

self.breaks = {}

return None

def get_bpbynumber(self, arg):

"""Return a breakpoint by its index in Breakpoint.bybpnumber.

For invalid arg values or if the breakpoint doesn't exist,

raise a ValueError.

"""

if not arg:

raise ValueError('Breakpoint number expected')

try:

number = int(arg)

except ValueError:

raise ValueError('Non-numeric breakpoint number %s' % arg) from None

try:

bp = Breakpoint.bpbynumber[number]

except IndexError:

raise ValueError('Breakpoint number %d out of range' % number) from None

if bp is None:

raise ValueError('Breakpoint %d already deleted' % number)

return bp

def get_break(self, filename, lineno):

"""Return True if there is a breakpoint for filename:lineno."""

filename = self.canonic(filename)

return filename in self.breaks and \

lineno in self.breaks[filename]

def get_breaks(self, filename, lineno):

"""Return all breakpoints for filename:lineno.

If no breakpoints are set, return an empty list.

"""

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):

"""Return all lines with breakpoints for filename.

If no breakpoints are set, return an empty list.

"""

filename = self.canonic(filename)

if filename in self.breaks:

return self.breaks[filename]

else:

return []

def get_all_breaks(self):

"""Return all breakpoints that are set."""

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):

"""Return a list of (frame, lineno) in a stack trace and a size.

List starts with original calling frame, if there is one.

Size may be number of frames above or below f.

"""

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=': '):

"""Return a string with information about a stack entry.

The stack entry frame_lineno is a (frame, lineno) tuple. The

return string contains the canonical filename, the function name

or '<lambda>', the input arguments, the return value, and the

line of code (if it exists).

"""

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>"

s += '()'

if '__return__' in frame.f_locals:

rv = frame.f_locals['__return__']

s += '->'

s += reprlib.repr(rv)

if lineno is not None:

line = linecache.getline(filename, lineno, frame.f_globals)

if line:

s += lprefix + line.strip()

else:

s += f'{lprefix}Warning: lineno is None'

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):

"""Debug a statement executed via the exec() function.

globals defaults to __main__.dict; locals defaults to globals.

"""

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):

"""Debug an expression executed via the eval() function.

globals defaults to __main__.dict; locals defaults to globals.

"""

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):

"""For backwards-compatibility. Defers to run()."""

# 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):

"""Debug a single function call.

Return the result of the function call.

"""

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():

"""Start debugging with a Bdb instance from the caller's frame."""

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.

When creating a breakpoint, its associated filename should be

in canonical form. If funcname is defined, a breakpoint hit will be

counted when the first line of that function is executed. A

conditional breakpoint always counts a hit.

"""

# 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]

@staticmethod

def clearBreakpoints():

Breakpoint.next = 1

Breakpoint.bplist = {}

Breakpoint.bpbynumber = [None]

def deleteMe(self):

"""Delete the breakpoint from the list associated to a file:line.

If it is the last breakpoint in that position, it also deletes

the entry for the file:line.

"""

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):

"""Mark the breakpoint as enabled."""

self.enabled = True

def disable(self):

"""Mark the breakpoint as disabled."""

self.enabled = False

def bpprint(self, out=None):

"""Print the output of bpformat().

The optional out argument directs where the output is sent

and defaults to standard output.

"""

if out is None:

out = sys.stdout

print(self.bpformat(), file=out)

def bpformat(self):

"""Return a string with information about the breakpoint.

The information includes the breakpoint number, temporary

status, file:line position, break condition, number of times to

ignore, and number of times hit.

"""

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 a condensed description of the breakpoint."

return 'breakpoint %s at %s:%s' % (self.number, self.file, self.line)

# -----------end of Breakpoint class----------

def checkfuncname(b, frame):

"""Return True if break should happen here.

Whether a break should happen depends on the way that b (the breakpoint)

was set. If it was set via line number, check if b.line is the same as

the one in the frame. If it was set via function name, check if this is

the right function and if it is on the first executable line.

"""

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

def effective(file, line, frame):

"""Return (active breakpoint, delete temporary flag) or (None, None) as

breakpoint to act upon.

The "active breakpoint" is the first entry in bplist[line, file] (which

must exist) that is enabled, for which checkfuncname is True, and that

has neither a False condition nor a positive ignore count. The flag,

meaning that a temporary breakpoint should be deleted, is False only

when the condiion cannot be evaluated (in which case, ignore count is

ignored).

If no such entry exists, then (None, None) is returned.

"""

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)')