cpython/Lib/bdb.py
1996-10-15 14:40:21 +00:00

368 lines
9.3 KiB
Python

# A generic Python debugger base class.
# This class takes care of details of the trace facility;
# a derived class should implement user interaction.
# There are two debuggers based upon this:
# 'pdb', a text-oriented debugger not unlike dbx or gdb;
# and 'wdb', a window-oriented debugger.
# And of course... you can roll your own!
import sys
import types
BdbQuit = 'bdb.BdbQuit' # Exception to give up completely
class Bdb: # Basic Debugger
def __init__(self):
self.breaks = {}
def reset(self):
import linecache
linecache.checkcache()
self.botframe = None
self.stopframe = None
self.returnframe = None
self.quitting = 0
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)
print 'bdb.Bdb.dispatch: unknown debugging event:', `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):
frame.f_locals['__args__'] = arg
if self.botframe is None:
# First call of dispatch since reset()
self.botframe = frame
return self.trace_dispatch
if not (self.stop_here(frame) or self.break_anywhere(frame)):
# No need to trace this function
return # None
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:
self.user_return(frame, arg)
if self.quitting: raise BdbQuit
def dispatch_exception(self, frame, arg):
if self.stop_here(frame):
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 stop_here(self, frame):
if self.stopframe is None:
return 1
if frame is self.stopframe:
return 1
while frame is not None and frame is not self.stopframe:
if frame is self.botframe:
return 1
frame = frame.f_back
return 0
def break_here(self, frame):
if not self.breaks.has_key(frame.f_code.co_filename):
return 0
if not frame.f_lineno in \
self.breaks[frame.f_code.co_filename]:
return 0
return 1
def break_anywhere(self, frame):
return self.breaks.has_key(frame.f_code.co_filename)
# 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_type, exc_value, exc_traceback)):
# This method is called if an exception occurs,
# but only if we are to stop at or just below this level
pass
# Derived classes and clients can call the following methods
# to affect the stepping state.
def set_step(self):
# Stop after one line of code
self.stopframe = None
self.returnframe = None
self.quitting = 0
def set_next(self, frame):
# Stop on the next line in or below the given frame
self.stopframe = frame
self.returnframe = None
self.quitting = 0
def set_return(self, frame):
# Stop when returning from the given frame
self.stopframe = frame.f_back
self.returnframe = frame
self.quitting = 0
def set_trace(self):
# Start debugging from here
try:
1 + ''
except:
frame = sys.exc_traceback.tb_frame.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.stopframe = self.botframe
self.returnframe = None
self.quitting = 0
if not self.breaks:
# no breakpoints; run without debugger overhead
sys.settrace(None)
try:
1 + '' # raise an exception
except:
frame = sys.exc_traceback.tb_frame.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 = 1
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.
# Call self.get_*break*() to see the breakpoints.
def set_break(self, filename, lineno):
import linecache # Import as late as possible
line = linecache.getline(filename, lineno)
if not line:
return 'That line does not exist!'
if not self.breaks.has_key(filename):
self.breaks[filename] = []
list = self.breaks[filename]
if lineno in list:
return 'There is already a breakpoint there!'
list.append(lineno)
def clear_break(self, filename, lineno):
if not self.breaks.has_key(filename):
return 'There are no breakpoints in that file!'
if lineno not in self.breaks[filename]:
return 'There is no breakpoint there!'
self.breaks[filename].remove(lineno)
if not self.breaks[filename]:
del self.breaks[filename]
def clear_all_file_breaks(self, filename):
if not self.breaks.has_key(filename):
return 'There are no breakpoints in that file!'
del self.breaks[filename]
def clear_all_breaks(self):
if not self.breaks:
return 'There are no breakpoints!'
self.breaks = {}
def get_break(self, filename, lineno):
return self.breaks.has_key(filename) and \
lineno in self.breaks[filename]
def get_file_breaks(self, filename):
if self.breaks.has_key(filename):
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
return stack, i
#
def format_stack_entry(self, frame_lineno, lprefix=': '):
import linecache, repr, string
frame, lineno = frame_lineno
filename = frame.f_code.co_filename
s = filename + '(' + `lineno` + ')'
if frame.f_code.co_name:
s = s + frame.f_code.co_name
else:
s = s + "<lambda>"
if frame.f_locals.has_key('__args__'):
args = frame.f_locals['__args__']
else:
args = None
if args:
s = s + repr.repr(args)
else:
s = s + '()'
if frame.f_locals.has_key('__return__'):
rv = frame.f_locals['__return__']
s = s + '->'
s = s + repr.repr(rv)
line = linecache.getline(filename, lineno)
if line: s = s + lprefix + string.strip(line)
return s
# The following two methods can be called by clients to use
# a debugger to debug a statement, given as a string.
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()
sys.settrace(self.trace_dispatch)
if type(cmd) <> types.CodeType:
cmd = cmd+'\n'
try:
try:
exec cmd in globals, locals
except BdbQuit:
pass
finally:
self.quitting = 1
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)
if type(expr) <> types.CodeType:
expr = expr+'\n'
try:
try:
return eval(expr, globals, locals)
except BdbQuit:
pass
finally:
self.quitting = 1
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):
self.reset()
sys.settrace(self.trace_dispatch)
res = None
try:
try:
res = apply(func, args)
except BdbQuit:
pass
finally:
self.quitting = 1
sys.settrace(None)
return res
def set_trace():
Bdb().set_trace()
# -------------------- 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, string
name = frame.f_code.co_name
if not name: name = '???'
fn = frame.f_code.co_filename
line = linecache.getline(fn, frame.f_lineno)
print '+++', fn, frame.f_lineno, name, ':', string.strip(line)
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)')